DEPARTMENT OF THE INTERIOR

FRANKLIN K. LANE, Secretary

UNITED STATES GEOLOGICAL SURVEY 

GEORGE OTIS SMITH, Director

Bulletin 695

THE

DATA OF GEOCHEMISTRY

FOURTH EDITION

BY

FRANK WIGGLESWORTH CLARKE

WASHINGTON

GOVERNMENT FEINTING OFFICE 

1920
V
CONTENTS.

INTRODUCTION............................................................. 9

( ; CHAPTER I. The chemical elements......................................... 12

Nature of the elements................................................. 12

Distribution of the elements............................................ 13

Relative abundance of the elements.................................... 22

,-' The periodic classification.............................................. 36

y Meteorites............................................................. 40

CHAPTER II. The atmosphere.............................................. 42

Composition of the atmosphere......................................... 42

The relations of carbon dioxide to climate..... ......................... 49

; Rainfall............................................................... 50

i The primitive atmosphere...................... ......... ................ 55

CHAPTER III. Lakes and rivers.................... ........................ 59

Origin...........:.......................... .......................... 59

Statement of analyses......................... ......'................... 60

The interpretation of analyses......................................... 62

^ Springs............................................................... 64

j- Changes of composition....................... ......................... 65

Analyses of river waters........................ ......................... 68

}' The St. Lawrence basin.................... ......................... 69

/ The Atlantic slope........................ ......................... 71

J The Mississippi basin............................................. 75

Southwestern rivers............................................... 82

Rivers of California................................................ 83

, The Columbia River basin.......................................... 84

Other northwestern rivers........................................... 86

Rivers of Alaska................................................... 87

The Saskatchewan system.......................................... 87

Summary for North America....................................... 89

' Rivers of South America............................................ 90

j Lakes and rivers of Europe.......................................... 93

Rivers of India and Java............................................ 104

\ The Nile.......................:.................................. 104

Organic matter in waters............................................... 105

Contamination by human agencies....................................... 108

Gains and losses in waters.............................................. 109

' Chemical denudation................................................... 110

CHAPTER IV. The ocean.:...........;..................................... 118

Elements in the ocean.........................:....................... 118

Composition of oceanic salts............................................. 121

, Carbonates in sea water................................................ 126

* Oceanic sediments.....................................................~. 129

i Potassium and sulphates............................................... 136

The chlorine of sea water.............................................. 137

The dissolved gases.................................................... 139

' Influence of living organisms on the ocean.............................. 145

Age of the ocean...................................................... 146

3
4 CONTENTS.

Page.

CHAPTER V. The waters of closed basins..................................... 152

Preliminary statement.............................. I................... 152

The Bbnneville basin................................. '................. 152

The Lahontan basin.................................................... 155 "i

Lakes of California.................................................... 158 t

Northern lakes.......................................................... 159

Central and South America............................................ 161 '

Caspian Sea and Sea of Aral............................................ 162

The Dead Sea......................................................... 163

Other Russian and Asiatic lakes........................................ 166

Miscellaneous lakes..................................................... 168 - 'x

Summary.............................................................. 169 ^

CHAPTER VI. Mineral wells and springs...................................... 175

Definition............................................................ 175

- Classification. ................'..... .................................... 176

Chloride waters........................................................ 177 )

Sulphate waters......................................:................. 183 l

Carbonate waters...................................................... 186 >

Waters of mixed type................................................... 188

Siliceous waters......:......,.......................................... 189

Nitrate, phosphate, and borate waters.................................... 191

Acid waters............................................................ 193 i

Summary of waters....................................................' 196 s

Changes in waters..................................................... 197 ^

Calcareous sinter...................................................... 198 \

Ocherous deposits..................................................... 199 \

Siliceous deposits...................................................... 200 }

Reactions with adjacent material....................................... 204

Vadose and juvenile waters............................................. 207

Thermal springs and volcanism......................................... 208

Bibliographic note. ....................^............................... 210 * CHAPTER VII. Saline residues............................................. 212

Deposition of salts...................................................... 212

Concentration of sea water............................................... 213

The Stassfurt salts....................................................... 216 ^

Other salt beds........................................................ 223

Analyses of salt........................................................ 225

Analyses of gypsum. ................................................... 226 ^

Bitterns............................................................... 227

Sodium sulphate...................................................... 228

Miscellaneous desert salts.............................................. 230

Alkaline carbonates.................................................... 231

Borates............................................................... 23-7

Nitrates................................ *...........................:. 248

The alums.............................................................. 254

CHAPTER VIII. Volcanic gases and sublimates............................... 255

Gaseous emanations................................................... 255 '

Sublimates............................................................. 264

Occluded gases. ...........'...................................I.I...... 268

Volcanic explosions.................................................... 280

Summary.............................................................. 284
CONTENTS. 5

Page.

CHAPTER IX. The molten magma......................................... 285

Temperature......................................................... 285

Influence of water..................................................«. 291

Magnetic solutions................... 1................................ 292

Eutectics............................................................ 295

Separation of minerals................................................ 298

Differentiation....................................................... 301.

Radioactivity...................................:..................... 307

CHAPTER X. Pvock-fprming minerals. ...................................... 316

Preliminary statement................................................ 316

Diamond and graphite................................................ 317

Native metals........................................................ 323

Sulphides........................................................... 328

Fluorides............................................................ 331

Corundum........................................................... 332

The spinels........................................................... 336

Hematite............................................................ 342

Titanium minerals..................................................... 343

Cassiterite and zircon................................................... 348

Phosphates........................................................... 34.9

The silica minerals.................................................... 352

The feldspars..................................................... 358

Leucite and analcite.............................................. 363

The nephelite group................................................ 366

The cancrinite-sodalite group....................................... 369

The pyroxenes..................................................... 371

The amphiboles................................................... 379

The olivine group................................................. 384

The micas....................................................... 387

The chlorites..................................................... 392

The melilite group............................................... 394

The garnets....................................................... 396

Vesuvianite....................................................... 399

The scapolites.......................:,............:.............. 399

loHte............................................................ 401

The zoisite group.................................................. 402

Topaz............................................ t ................ 404

The andalusite group. ............................................ 405

Staurolite......................................................... 407

Lawsonite......................................................... 407

Dumortierite...................................................... 408

Tourmaline...................................................... 408

Beryl..................................................;........... 410

Serpentine, talc, and kaolinite.................................... 410

The zeolites...................................................... 412

The carbonates...............................'......................... 413

CHAPTER XI. Igneous rocks............................................... 415

Preliminary considerations. ........................................... 415

Classification.......................................................... 416

Composition of rocks.................................................. 429

The rhyolite-granite group........................:................ 430

The trachyte-syenite group. ........................................ 434

Nephelite rocks.................................:................. 438
6 CONTENTS.

CHAPTER XI. Igneous rocks Continued.

Composition of rocks Continued. Page.

Leucite rocks.................................................... 442

-Analcite rocks..................................................... 444

The monzonite group.............................................. 446

The andesite-diorite series......................................... 448

The basalts. ..................................................... 452

Diabase........................................................... 455

The gabbros.........:............................................. 456

Feniic rocks....................................................... 458

Basic rocks....................................................... 461

Limiting conditions................................................... 464

Proximate calculations................................................. 46S

CHAPTER XTI. The decomposition of rocks. ................................ 471

The general process. .................................................. 471

Solubility of minerals................................................. 473

Effects of vegetation................................................... 478

Influence of bacteria.................. 1................................ 480

Influence of animal life................................................ 480

Products of decomposition............................................. 481

Rate of decomposition................................................ ' 485

Kaolin................................................................ 486

Laterite and bauxite, ;................................................. 488

Absorption.'.......................................................... 496

Sand.................................................................. 497

Silt. ................................................................. 499

Glacial and residual clays. ............................................ 502

Loess.................................................................. 504

Marine sediments...................................................... 507

Glauconite............................................................ 511

Phosphate rock........................................................ 515

Ferric hydroxides..................................................... 526

Manganese .ores. ...................................................... 531

CHAPTER XIII. Sedimentary and cletrital rocks............................ 535

Sandstones........................................................... 535

Flint and chert........................................................ 540

Shale and slate......................................................... 543

Limestone............................................................ 546

Dolomite....................'..............:......................... 557

Magnesite............................................................ 572

Iron carbonate...'..................................................... 573

Silicated iron ores. ................................................... 576

Gypsum. ............................................................ 578

Native sulphur........................................................ 578

Celestite. .............................................................. 581

Barite. ................................ ....^......................... 582

Fluorite. ..................'.......................................... 585

CHAPTER XIV. Metamorphic rocks. ........................................ 58G

Metamorphic processes. ............................................... 586

Classification.......................................................... 591

Uralitization.......................................................... 592

Glaucophane schists. ................................................. 594

Serialization.......................................................... 596

Other alterations of feldspar. .......................... ................. 597
CONTENTS. 7

CHAPTER XIV. Metamorphic rocks Continued. Page.

Chloritization........................................................ 602

Constitutional formulae................................................. 603

Talc and serpentine.................................................. 605

Quartzite. ......:.........................:..................,........ 609

Metamorphosed shales................................................. 611

, Ferruginoxis schists................................................... 612

} Dehydration of clays.................................................. 613

} Mica schist...................:........................................ 617

' Gneiss............................................................... 621

I Metamorphic limestones. . . . ............................................ 623

k Diagnostic criteria..................................................... 627

I CHAPTER XV. Metallic ores................................................. 629

Definition............................................................ 629

Source of metals...................................................... 630

* Gold................................................................. 646

\ Silver................................................................. 653

Copper.............................................................. 660

Mercury............................................................. 670

Zinc and cadmium.................................................... 675

Lead................................................................. 683

Tin................................................................... 690

Arsenic, antimony, and bismuth...................................... 694

Nickel and cobalt....................................................... 698

Chromium........................................................... 702

Molybdenum and tungsten............................................. 704

The platinum metals................................................. 707

Vanadium and uranium................................................ 712

Columbium, tantalum, and the rare earths............................. 717

CHAPTER XVI. The natural hydrocarbons.................................. 721

Composition......................'....,............................... 721

Syntheses of petroleum................................................ 730

Origin of petroleum.................................................... 734

CHAPTER XVII. Coal...................................................... 746

Origin of coal.......................................................... 747

Peat................................................................. 750

, Lignite.............................................................. 753

Bituminous coal...................................................... 758

J Anthracite........................................................... 761

The variations of coal.................................................. 763

The gases in coal..................................................... 765

Artificial coals. ..................................................... 768

The constitution of coal................................................ 771

INDEX. . ................................................................... 775

THE DATA OF GEOCHEMISTRY.1

By F. W, CLAUSE.

INTRODUCTION.

 - In the crust of the earth, with its liquid and gaseous -envelopes, the

s ocean and the atmosphere, about -.eighty chemical elements are now

recognized. These elements, the primary units of chemical analysis,

I* are widely different as regards frequency; some are extremely rare,

others are exceedingly abundant. A few occur in nature uncornbined;

but most of them are found only in combination. The compounds

thus .generated, the secondary units of -geochemistry, :are known

';_ .as mineral species; and of .these, excluding substances of organic

origin, only about a thousand have yet been identified. By .artificial

* means innumerable compounds can be formed; but in the chemistry 

/ of the earth's crust the range of possibility aeems to be extremely 

. - limited. From time to time new elements .and new mineral species

-' are discovered; but it is highly probable that all of them which have 

) .any large importance in the economy of nature are alxeady known. 

The rarest substances, however, whether (elementary osr .compound, 

, supply -data for the solution of chemical problems; they can not, 

. therefore, be ignored or set to .one side as having no significance. In 

\ scientific investigation all evidence is of value. 

1 By the -aggregation of mineral species into large masses rocks are 

produced; and these .are the fundamental units of geology. Some 

rocks, such as quartzite or limestone, consist of -one mineral only, more 

or Jess impure; but most rocks .are mixtures of .species, in which, 

' >!. either by the microscope or by the naked .eye, the individual compoV nents can be clearly distinguished. Being mixtures, .rocks are widely 

| variable in composition.; and yet .certain types .are of common occurrence, while others are small in quantity and rare. The commonest 

rock-forming minerals are naturally the more stable compounds of 

.the most abundant elements; and the rocks themselves represent the 

\ outcome of relatively simple rather than of complex reactions. Sim- 

^ plicity of constitution seems to be the prevailing rule. An eruptive 

rock, for example, may be composed mainly of eight chemical eleI ' The first edition of this volume was published in 1908 as Bulletin 330 of the United States Geological 

) Survey. A second edition appeared in 1911 as Bulletin 491, and athird in 1916, as Bulletin 616. The work 

has been revised and enlarged for the present edition.

9
10 DATA OF GEOCHEMISTRY.

ments, namely, oxygen, silicon, aluminum, iron, calcium, magnesium, 

sodium, and potassium. These elements are capable of combining so 

as to form some hundreds of mineral species; and yet only a few of the 

latter appear in the rock mass. The less stable species rarely occur;. 

the more stable always predominate. The reactions which took place 

during the formation of the rock were strivings toward chemical 

equilibrium, and a maximum of stability under the existing conditions was the necessary result. The rarer rocks, like many of the 

rarer minerals, are the products of exceptional conditions; but the 

tendency toward stable equilibrium is always the same. Each rock 

may be regarded, for present purposes, as a chemical system, in 

which, by various agencies, chemical changes can be brought about. 

Every such change implies a disturbance of equilibrium, with the 

ultimate formation of a new system, which, under the new conditions, 

is itself stable in turn. The study of these changes is the province 

of geochemistry. To determine what changes are possible, how and 

when they occur, to observe the phenomena which attend them, and 

to note their final results are the functions of the geochemist. Analysis and synthesis are his two chief instruments of research, but they 

become effective only when guided by a broad knowledge of chemical 

principles, which correlate the data obtained and extract from the 

evidence its full meaning. From a geological point of view the solid 

crust of the earth is the main object of study; and the reactions which 

take place in it may be conveniently classified under three heads 

first, reactions between the essential constituents of the crust itself; 

second, reactions due to its aqueous envelope; and third, reactions 

produced by the agency of the atmosphere. That the three classes 

of reactions shade into one another, that they are not sharply defined/ 

must be admitted; but the distinction between them is valid enough 

to serve a good purpose in the arrangement and discussion of the 

data. Under the first heading the reactions which occur in volcanic 

magmas and during their contact with rock masses are studied; 

under the second we find the changes due to percolating waters and 

the chemistry of natural waters in general; the essentially surficial 

action of the atmosphere forms the subject matter of the third.

Furthermore, for ^convenience of study, the solid crust of the earth 

may be regarded as made up of three shells or layers, which interpenetrate one another to some extent, but which are, nevertheless, 

definite enough to consider separately. First and innermost there 

is a shell of crystalline or plutonic rocks, of unknown thickness, 

which forms the nearest approach to the original material of which 

the crust was composed. Next, overlying this layer, is a shell of 

sedimentary and fragmental rocks; and above this is the third layer 

of soils, clays, gravels, and the like unconsolidated material. The 

second and third shells are relatively thin and consist of material
INTRODUCTION. 11

derived chiefly from the first, in great part through the transforming 

agency of waters and of the atmosphere, although organic life has 

had some share in bringing about certain of the changes. In addition to the substances which the two derived layers have received 

from the original plutonic mass they contain carbon and oxygen taken 

up from the atmosphere, and also a considerable proportion of water 

which has become fixed in the clays and shales. Along with this gain 

of material there has^een a loss of salts leached out into the ocean, 

but the factor of increase is the larger. When igneous rocks are 

transformed into sedimentary rocks, there is an average net gain of 

weight of 8 or 9 per cent, as roughly estimated from the composition 

of the various kinds of rock under consideration. To some extent, 

then, the ocean and the atmosphere are being slowly absorbed by and 

fixed in the solid crust of the earth; although under certain conditions this tendency is reversed, with liberation of water and of gases. 

A perfect balance of this sort, however, can not be assumed; and how 

far the main absorptive process may go it is hardly worth while to 

conjecture. The data available for the solution of the problem are 

too uncertain.

Upon the subject of geochemistry a vast literature exists, but it is 

widely scattered and portions of it are difficult of access. , The 

general treatises, like the classical works of Bischof and of Roth, 

are not recent, and great masses of modern data are as yet uncorrelated. The American material alone is singularly rich, but most 

of it has been accumulated since Roth's treatise was published. 

The science of chemistry, moreover, has undergone great changes 

during the last 25 years, and many subjects now appear under new 

and generally unfamiliar aspects. The methods and principles of 

physical chemistry are being more and more applied to the solution 

of geochemical problems, 1 as is shown by the well-known researches 

of Van't Hoff upon the Stassfurt salts and the magmatic studies of 

Vogt, Doelter, and others. The great work in progress at the geophysical laboratory of the Carnegie Institution is another illustration 

of the change now taking place in geochemical investigation. To 

bring some of the data together, to formulate a few of the problems 

and to present certain general conclusions in their modern form are 

the purposes of this memoir. It is not an exhaustive monograph 

upon geochemistry, but rather a critical summary of what is now 

known, and a guide to the more important literature of the subject. 

If it does no more than to make existing data available to the reader, 

its preparation will be justified.

1 Principles of chemical geology, by ,T. V.- Elsden (London, 1910), is an excellent though brief treatise on 

this aspect of geochemistry. It covers, however, only a small portion of the field.
CHAPTER I.

THE CHEMICAL ELEMENTS. 

NATURE OF THE ELEMENTS.

Although, many thousands of compounds ar6 known to chemists, 

and an almost infinite number are possible, they reduce on analysis 

to a small group of substances which are called elements. It is not 

necessary for the geologist to speculate on the ultimate nature of 

these bodies; it is enough for him to recognize the fact that all the 

compounds found in the earth are formed by their union with one 

another and that they are not to any considerable extent reducible 

to simpler forms of matter by any means now within our control. 

To the geochemist, generally speaking, they are the final results of 

analysis, beyond which it is rarely necessary to go. This statement, 

however, must not be taken without qualification. It is probable, 

as shown by the writer "many years ago, 1 that the elements were 

originally developed by a process of evolution from much simpler 

forms of matter, as is indicated by the progressive chemical complexity observed in passing from the nebulse through the hotter 

stars to the cold planets. Changes in the opposite direction have 

been discovered through recent investigations upon radioactivity, 2 

by which an actual breaking down of some elements is proved. 

Uranium undergoes a slow metamorphosis to radium, and radium 

in turn passes through a series of changes which ends in the production of helium. Thorium 'also exhibits a similar instability, but 

thorium, radium, and uranium are elements of high atomic weight, 

and therefore, in all probability, of maximum complexity. It is 

conceivable that all the elements may be similarly unstable, but in 

so slight a degree that their transmutations have not yet been 

detected. Speculations of this order, however, can be left out of 

consideration now. For present purposes the recognized elements 

are our fundamental chemical units, and the questions of their 

origin and transmutability may be neglected.

At present the elements enumerated in the subjoined table are 

known, all doubtful substances being omitted. The radioactive 

elements, polonium, actinium, radiothorium, ionium, etc., are also 

disregarded for the reasons that they are imperfectly known and 

geologically unimportant.

». F. AV. Clarke, Pop. Sei. Monthly, January, 1873. See also the later well-known speculations of 

J. Norman Locsyer. 

s This subject will be discussed at length later.

12
THE CHEMICAL ELEMENTS.

The chemical elements.

13

Argon........... . . .

Cadmium .........

Calcium. ..........

Carbon.............

Cerium.............

Chlorine......

Chromium...... ....

Cobalt. ...........

Columbium.... ....

Copper............ .

Fluorine ..........

Gadolinium .......

Gallium............

Glucinum. .........

Gold..............

Hydrogen. ........

Indium............

Iridium......... . . .

Iron ..............

Lithium............

Symbol.

Al

Sb

A

As

Ba

Bi

B

Br

Cd

Cs

Ca

C

Ce

Cl

Cr

Co

Cb

Cu

Dy

Er

Eu

F

Gd

GP

Gl

Au

HP

Ho

H

In

I

Ir

Fe

Kr

La

Pt>

Li

Lu

Mg

Mn

Hg

Atomic 

weight.

27.1

120.2

39.9

74.96

137. 37

208.0

10.9

79.92

112. 40

132. 81

40.07

12. 005

140. 25

35.46

52.0

58.97

93.1

63.57

162.5

167. 7

152.0

19.0

157.3

70.1

72.5

9.1

197.2

4.00

163.5

1.008

114.8

126. 92

193.1

55.84

82.92

139.0

207. 20

6.94

175. 0

24.32

54.93

200.6

Neon" ..............

Nitrogen............

Oxygen............

Platinum. .........

Potassium........ ..

Praseodymium. .....

Radium ...........

Rhodium ..........

Rubidium......

Ruthenium. .......

Samarium. .........

Scandium...........

Selenium. .........

Silicon...... .......

Silver .............

Sodium.............

Sulphur ...........

Tantalum. ..........

Tellurium..... .....

Terbium............

Thallium.. .........

Thorium. ...........

Thulium..... ......

Tin.................

Titanium. .........

Tungsten....... ....

Ytterbium (NeoytYttrium....... .....

Zinc. ..............

Symbol.

Mo

Nd.

Ne Ni 

Nt

N

Os

0

Pel

P

Pt

K

Pr

Ra

Rh

Rb

Ru

Sa

Sc

Se

Si

Ag

Na

Sr

S

Ta

Te

Tb

Tl

Th

Tm

Sn

Ti

W

u

V

Xe

Yb

Yt

Zn

Zr

Atomic 

weight.

96.0

144. 3

20.2

58. GS

222.4

14. 008

190.9

16. 00

106.7

31. 04

195. 2

39. 10

140. 9

226.0

102. 9

85.45

101.7

150. 4

44.1

79.2

28.3

107. 88

23.00

87.63

32.06

181.5

127.5

159.2

904 n

232. 15

168. 5

118.7

48.1 

184.0

238.2

51.0

130.2

173.5

89.3

65.37

90.6

DISTRIBUTION OF THE ELEMENTS. 1

The elements differ widely in their abundance and in their mode of 

distribution in nature. Under the latter heading the more important 

data may be summarized as follows:

Aluminum. The most abundant of all the metals. An essential 

constituent of all important rocks except the sandstones and limestones, and even in these its compounds are common impurities. 

Being easily oxidized, it nowhere occurs native. Found chiefly in

1 For an early table showing distribution, see Elie de Beaumont, Bull. Soc. g<5ol. France, 2d ser., vol.4, 

1846-47, p. 1333.
14 DATA OF GEOCHEMISTRY.

silicates, such as the feldspars, micas, clays, etc.; but also as the 

oxide, corundum; the hydroxide, bauxite; as fluoride in cryolite; and 

in various phosphates and sulphates. With the exception of the 

fluorides, only oxidized compounds of aluminum are known to exist 

in nature.

Antimony. Common, but neither abundant nor widely diffused. 

Found native, more frequently as the sulphide, stibnite, also in various antimonides and sulphantimonides of the heavy metals, and as 

oxides of secondary origin. The minerals of antimony are generally 

found in metalliferous veins, but the amorphous sulphide has been 

observed as a deposit upon sinter at Steamboat Springs, Nevada.

Argon. AIL inert gas that forms nearly 1 per cent of the atmosphere, and is also found in some mineral springs. No compounds of 

argon are known.

Arsenic. Found native, in two sulphides, in various arsenides and 

sulpharsenides of the heavy metals, as oxide, and in a considerable 

number of arsenates. Arsenopyrite is the commonest arsenical mineral. Arsenic is very widely diffused, and traces of it exist normally 

even in organic matter. It is not an uncommon ingredient in mineral, especially thermal, springs. In its chemical relations it is 

regarded as nonmetallic and closely allied to phosphorus.

Barium. Widely distributed in small quantities throughout the 

igneous rocks, probably as a minor constituent of the feldspars and 

micas, although other silicates containing barium are known. Commonly found concentrated as the sulphate, barite, or as the carbonate, 

witherite. This element occurs only in oxidized compounds.1

Bismuth. Resembles antimony in its modes of occurrence, but is 

less common. Native bismuth and the sulphide, bismuthinite, are its 

chief ores. Two silicates of bismuth, several sulphobismuthides, and 

the telluride, oxide, carbonate, molybdate, vanadate, and arsenate 

exist as relatively rare mineral species.

Boron. An essential constituent of several silicates, notably of 

tourmaline and datolite. Its compounds are obtained commercially 

from borates, such as borax, ulexite, and colemanite, or from native 

orthoboric acid, sassolite, which is found in the waters of certain 

volcanic springs. Some alkaline lakes qr lagoons, especially in California and Tibet, yield borax in large quantities.

Bromine. Found in natural waters in the form of bromides. Sea 

water contains it in appreciable quantities, and much bromine has 

been extracted from the brine wells of West Virginia and Michigan. 

The bromide and chlorobromide of silver are well-known ores.

Cadmium. A relatively rare metal found in association with zinc, 

which it resembles. Occurs usually as the sulphide, greenockite.

i On barium in soils, see G. H. Failyer, Bull. Bur. Soils No. 72, U. S. Dept. Agr., 1910.
THE CHEMICAL ELEMENTS. 15

Caesium. A rare metal of the alkaline group, allied to potassium. 

Often found in lepidolite, and in the waters of some mineral springs. 

The very rare mineral pollucite is a silicate of aluminum and caesium.

Calcium. One of the most abundant metals, but never found in 

nature uncombined. An essential constituent of many rock-forming 

minerals, especially of anorthite, garnet, epidote, the amphiboles, 

the pyroxenes, and sqapolite. Limestone is the carbonate, fluorspar 

is the fluoride, and gypsum is the sulphate of calcium. Apatite is 

the fluophosphate or chlorophosphate of this metal. Many other 

mineral species also contain calcium, and it is found in nearly all 

natural waters and in connection with organized life, as in bones 

and shells. Calcium sulphide has been identified in meteorites.

Carbon. The characteristic element of organic matter. In the 

mineral kingdom carbon is found crystallized as graphite and diamond and also amorphous in coal. Carbon dioxide is a normal 

constituent of atmospheric air. Natural gas, petroleum, and bitumen 

are essentially hydrocarbons. Carbonic acid and carbonates exist 

in most natural waters, and great rock masses are composed of carbonates of calcium, magnesium, and iron. A few silicates contain carbon, but of these, cancrinite is the only species having petrographic 

importance.

Cerium. One of the group of elements known as the metals of the 

rare earths. These substances are generally found in-granites or 

elseolite syenites, or in gravels derived therefrom. Cerium exists 

in a considerable number of mineral species, but the phosphate, 

monazite, and the silicates, cerite and allanite, are all that need be 

mentioned here.

Chlorine. Tine most abundant element of the halogen group. 

Commonly found as sodium chloride, as in sea water and rock salt. 

Also in certain rock-forming minerals, such as sodalite and the 

scapolites, and in a variety of other minerals of greater or less importance. Silver chloride, for example, is a well-known ore, and 

carnallite is valuable for the potassium which it contains.

Chromium. Very widely diffused, generally in the form of chromite, and most commonly in magnesian rocks. A few chromates and 

several silicates containing chromium are also known, but as relatively rare minerals.

Cobalt. Less abundant than nickel, with which it is generally 

associated. Usually found as sulphide or arsenide, or in oxidized 

salts derived from those compounds.

Columbium. 1 A rare acid-forming element resembling and associated with tantalum. Both form salts with iron, manganese, calcium, 

uranium, and the rare-earth metals, the minerals columbite, tan tali te,

1 Also known as "niobium." Tho name colnmbiu:u hns more than 40 years' priority.
16 ' DATA OF GEOCHEMISTRY. I

and samarskite being typical examples. All these minerals are * 

most abundant in pegmatite veins.

Copper. Minute traces of this metal are often detected in igneous 

rocks, although they are rarely determined quantitatively. Also 

present in sea water in very small amounts. Its chief ores are 

native copper, several sulphides, two oxides, and two carbonates. 

The arsenides, arsenates, antimonides, phosphates, sulphates, and x 

silicates also exist in nature, but are less important. In chalcopyrite and bornite, copper is associated with iron.

Dysprosium. A little-known metal of the rare earths.

Erbium. One of the rare-earth metals of the yttrium group. See -< 

"Yttrium." -

Europium. Another metal of the rare earths, of slight importance. x

Fluorine. The most characteristic minerals of fluorine are calcium fluoride (fluor spar) and cryolite, a fluoride of aluminum and 

sodium. Apatite is a phosphate containing fluorine, and the element 

is also found in a goodly number of silicates, such as topaz, tourmaline, the micas, etc. Fluorine, therefore, is commonly present in 

igneous rocks, although in small quantities.

Gadolinium. One of the metals of the rare earths. See ' 'Cerium " 

and "Yttrium."

Gallium. A very rare metal whose salts resemble those of aluminum. Found in traces in many zinc blendes. Always present 

in spectroscopic traces in bauxite and in nearly all aluminous 

minerals.

Germanium. A very rare metal allied to tin. The mineral argyrodite is a sulphide of germanium and silver.

Glucinum. A relatively rare metal, first discovered in beryl, from 

which the alternative name beryllium is derived. Found also in the 

aluminate, chrysoberyl; in several rare silicates and phosphates; 

and in a borate, hambergite. As a rule the minerals of glucinum 

occur in granitic rocks.

Gold. Found in nature as the free metal and in tellurides. Very 

widely distributed and under a great variety of conditions, but 

almost invariably associated with quartz or pyrite. Gold has been 

observed in process of deposition, probably from solution in alkaline 

sulphides, at Steamboat Springs, Nevada. It is also present, in very 

small traces, in sea water.

Helium. An inert gas obtained from uraninite. The largest 

quantities are derived from the Ceylonese thorianite and the highly 

crystalline uraninite found in pegmatite. The massive mineral from 

metalliferous veins contains little or no helium. Traces of helium 

also exist in the atmosphere, in spring waters, and in some samples 

of natural gas.

Holmium. One of the rare-earth metals. Little known.
THE CHEMICAL ELEMENTS. - 17

J Hydrogen. This element forms about one-ninth part by weight 

' of water, and therefore it occurs almost everywhere in nature. In 

a majority of all mineral species, and therefore in practically all 

rocks, it is found, either as occluded moisture, as water of crystallization, or combined as hydroxyl. All organic matter contains 

: hydrogen, and hence it is an essential constituent of such derived 

substances as natural gas, petroleum, asphaltum, and coal. The 

 ' free gas has been detected in the atmosphere, but in very minute 

/ quantities,

Indium. A rare metal, found in very small quantities in certain 

^ zinc blendes. Spectroscopic traces of it can be detected in many 

minerals, especially in iron ores.

Iodine. The least abundant element of the halogen group. Found 

 , in sea water, in certain mineral springs, and in a few rare minerals, 

> especially the iodides of silver, copper, and lead. Calcium iodate, 

lautarite, exists in the Chilean nitrate beds.

Iridium. A metal of the platinum group. See ''Platinum." 

Iron. Next to aluminum, the most abundant metal, although 

native iron is rare. Found in greater or less amount in practically 

all rocks, especially in those which contain amphiboles, pyroxenes, 

micas, or olivine. Magnetite and hematite are oxides of iron, limon- 

's ite is a hydroxide, pyrite and marcasite are sulphides, siderite is 

{ the carbonate, and there are also many silicates, phosphates, arse- 

/ nates, etc., which contain this element. The mineral species of which 

iron is a normal constituent are numbered by hundreds.

Krypton. An inert gas of the argon group, found in small quanti- 

/' ties in the atmosphere.

Lantlianum. A metal of the rare-earth group, almost invariably 

associated with cerium, <£ v. Lanthanite is the carbonate of 

lanthanum.

Lead. Found chiefly in the sulphide, galena, from which, by

alteration, various oxides, the sulphate, and the carbonate are derived.

Native lead is rare. A number of sulphosalts are known, several

[ silicates, and also a phosphate, an arsenate, and some vanadates.

Galena is frequently associated with pyrite, marcasite, and sphalerite.

Lithium. One of the alkaline metals. Traces of it are foimd in

nearly all igneous rocks, and in the waters of many mineral springs.

The more important lithia minerals are lepidolite, spodumene, petalite, amblygonite, triphylite, and the lithia tourmalines.

) Lutecium. One of the rare-earth minerals. See "Yttrium and

ytterbium."

Magnesium. One of the most abundant metals. In igneous rocks

it is represented by amphiboles, pyroxenes, micas, and olivine. Talc,

chlorite, and serpentine are common magnesian silicates, and

dolomite, the carbonate of magnesia and lime, is also found in

113750° 19 Bull. 695 2
18 > DATA 0-F GEOCHEMISTRY. -

enormous quantities. Magnesium compounds occur in sea water and 

in many mineral springs. The metal is not found native..

Manganese. Widely diffused in small quantities. Found in most 

rocks and in some mineral waters. Never native. Occurs commonly 

in silicates, oxides,, and carbonates, less frequently in sulphides, 

phosphates, tungstates, columbates, etc. The dioxide, pyrolusite, 

and the hydroxide, psilomelaner are the commonest manganese 

minerals.

Mercury. This metal is neither abundant nor widely diffused. 

Exists as native mercury, but is usually found,, locally concentrated, 

in the form of the sulphide, cinnabar. Chlorides of mercury, the 

oxide, the selenide, and the telluride, are relatively rare minerals. 

Cinnabar has been observed in process of deposition by solfataric 

action at Sulphur Bank, California; and Steamboat Springs, Nevada.

Molybdenum. One of the rarer metals. Most frequently found in 

granite in the form of the sulphide,, molybdenite. The molybdates 

of iron, calcium, bismuth, and lead are also known as mineral species.

Neodymium. One of the. rare-earth metals associated with cerium.

Neon. An inert, gas of the argon group, found in minute, traces in 

the atmosphere?..

Nickel. Closely allied to cobalt. Found native, alloyed with 

iron, in meteorites and in the terrestrial minerals awaruite and 

josephimte. Very frequently detected in igneous rocks, probably 

as a constituent of olivine.. Occurs primarily in silicates, sulphides, 

arsenides, antimonides, and as telluride, and secondarily in several 

other minerals. The presence of nickel is especially characteristic 

of magnesian igneous rocks, and it is generally associated in them 

with chromium.

Niton. The gaseous emanation of radium. It is the highest 

member of the argon group.

Nitrogen. The predominant element of the atmosphere, in which 

it is uneoinbined. Also abundant in organic matter, and in such 

derived substances as coal. Nitrates Jire found in the soil and in 

cave earth; and in some; arid regions, as in Chile, they exist in 

enormous quantities. Some volcanic waters contain nitrogen in the 

form of ammonium compounds.

Osmium. A metal of the platinum group. See "Platinum."

Oxygen. The most abundant of the elements, forming about onehalf of all known terrestrial matter. In the free state it constitutes 

about one-fifth of the atmosphere:; and in water it is the chief element of the ocean. All important rocks contain oxygen in proportions ranging from 45 to 53 per cent.

Palladium. A metal of the- platinum group.

Phosphorus. Found in nearly all igneous rocks, generally as a 

constituent of apatite. With one or two minor exceptions, it exists
THE CHEMICAL, ELEMENTS. 19

in the mineral kingdom only in the form of phosphates, of which a 

large number are known. An iron phosphide occurs in meteorites. 

Phosphorus is also an essential constituent of living matter, especially of bones, and certain large deposits of calcium phosphate are 

of organic origin.

Platinum. Platinum, iridium, osmium, ruthenium, rhodium, and 

palladium constitute a group of metals of which the first named is 

the most important. As a rule they are found associated together, 

and generally uncombined. To the latter statement there are two 

know]! exceptions sperrylite is platinum arsenide, and laurite is 

ruthenium sulphide. Native platinum, platiniridium, iridosmine, 

and native palladium are all reckoned as definite mineral species. The 

metals of this group are commonly found associated with magnesian 

rocks, or in gravels derived from them. Chromite often accompanies 

platinum, and so also do the ores of nickel. Sperrylite is found in 

the nickeliferous deposits at Sudbury, Canada; and has also been 

identified in the sulphide ores of .the Rambler mine in Wyoming. In 

the latter ores palladium is present also, and possibly, like the 

platinum, as arsenide.

Potassium. An abundant metal of the alkaline group. Found in 

many rocks, especially as a constituent of the feldspars, micas, and 

leucite. Nearly all terrestrial waters contain potassium, and the 

saline beds near Stassfurt, Germany, are peculiarly rich in it.

Praseodymium. A rare-earth metal associated with cerium.

Radium. A very rare metal of the calcium-barium group. Obtained in minute quantities from uraninite and carnotite. Of possible 

importance in the study of volcanism. According to R. J. Strutt,1 

traces of radium can be detected in all igneous rocks.

Rhodium. A metal of the platinum group. See "Platinum/'

Rubidium. An alkaline metal intermediate between potassium 

and caesium. Found in lepidolite and in some mineral springs. 

Rubidium is reported as present in the waters of the Caspian Sea.

Ruthenium. A metal of the platinum group. See "Platinum."

Samarium. A rare-earth metal obtained from samarskite.

Scandium. A rare-earth metal obtained from euxenite, and also 

from wolfram. According to G. Eberhard 2 it is the most widely 

diffused of all the rare-earth group, although it is found only in very 

small quantities.

Selenium. A nonmetallic element allied to sulphur, with which it 

is commonly associated. Found native, and also in the selenides of 

copper, silver, mercury, lead, bismuth, and thallium. A few selenites 

exist as secondary minerals,

1 Proc. Roy. Soc., vol. 77, ser. A, 1900, p. 472.

2 Sitzitngsb. Berlin Akad., 1908, p. 851. See also a later paper in Chem. News, vol. 102, 1910, p. 211. 

On scandium in American wolfram, see H. S. Lukens, Jour. Am. Chcm. Soc., vol. 35,1913, p. 1470.
20 DATA OF GEOCHEMISTRY.

Silicon. Next to oxygen, the most abundant element. Found in 

quartz, tridymite, opal, and all silicates. The characteristic element 

of all important rocks except the carbonates. Silica also exists in 

probably all river, well, and spring waters. From volcanic waters it 

is deposited in the form of sinter.

Silver. This metal occurs native, as sulphide, arsenide, antimonide, 

telluride, chloride, bromide, iodide, and in numerous sulphosalts. 

Native gold generally contains some silver, and the latter is also often 

associated with native copper. Oxidized compounds of silver are 

known only as artificial products. Small traces of silver exist in sea 

water.

Sodium. The most abundant of the alkaline metals. In igneous 

rocks it is a constituent of the feldspars, of the nepheline group of 

minerals, and of certain pyroxenes, such as segirite. Also abundant 

in rock salt, and in nearly all natural waters, sea water especially.

Strontium. A metal intermediate between calcium and barium, 

but less abundant than the latter. Strontium in small.amount is a 

common ingredient of igneous rocks. The most important strontium 

minerals are the sulphate, celestite, and the carbonate, strontianite.

Sulphur. Found native and in many sulphides and sulphates. 

Also in igneous rocks in the sulphatosilicates, hauynite and nosean. 

Native sulphur is abundant in volcanic regions and is also formed 

elsewhere by the reduction of sulphates. Pyrite is the commonest 

of the sulphides, gypsum of the sulphates. Alkaline sulphates are 

obtainable from many natural waters. Sulphur also exists in coal 

and petroleum.

Tantalum. A rare acid-forming element akin to columbium, with 

which it is usually associated.

Tellurium. A semimetallic element, the least abundant of the 

sulphur group. Found native, and in the tellurides of gold, silver, 

lead, bismuth, mercury, nickel, and copper. Its oxide and a few rare 

telmrates or tellurites are known as alteration products.

Terbium. A rare-earth metal of the yttrium group. See 

"Yttrium."

Thallium. One of the rarer heavy metals. Found as an impurity 

in pyrite and some other sulphides. The rare mineral crookesite is 

a selenide of copper and thallium, and lorandite is sulpharsenide of 

thallium. Vrbaite is a sulphide of arsenic, antimony, and thallium.

Thorium. A rare metal of the titanium-zirconium group, the most 

basic of the series. Chiefly obtained from monazite sand. Also 

known in silicates, such as thorite, in some columbo-tantalates, and 

in certain varieties of uraninite.

Thulium. A rare-ear.th metal of which little is known.

Tin. Very rare native. Most abundant as the oxide, cassiterite, 

which is found in association with granitic rocks. Traces of tin have 

been detected in feldspar. Stannite, or tin pyrites, is a sulphide of
THE CHEMICAL ELEMENTS. 21

tin, copper, and iron, and a few other rare minerals contain this element.

Titanium. This element is almost invariably present in igneous 

rocks and in the sedimentary material derived from them. Out of 

800 igneous rocks analyzed in the laboratory of the United States 

Geological Survey, 784 contained titanium. Its commonest occurrences are as titanite, ilmenite, rutile, and perofskite. The element 

is often concentrated in beds of titanic iron ore.

Tungsten. An acid-forming heavy metal allied to molybdenum. 

Found as tungstates of iron, manganese, calcium, and lead in the 

minerals wolfram, hubnerite, scheelite, and stolzite, and also as a 

sulphide, tungstenite.

Uranium. A heavy metal found chiefly in uraninite, carnotite, 

samarskite, and a few other rare minerals. The phosphates, autunite 

and torbernite, are not uncommon in granites, and uraninite, although 

sometimes obtained from metalliferous veins, is more generally of 

granitic association. Carnotite occurs with sedimentary sandstones.

Vanadium. A rare element, both acid and base forming, and allied 

to phosphorus. Found in vanadates, such as vanadinite, descloizite, 

and pucherite, associated with lead, copper, zinc, and bismuth. Also 

in the silicates roscoelite and ardennite. Carnotite, which was mentioned in the preceding paragraph, is an impure vanadate of potassium and uranium. Sulvanite is a sulphovanadate of copper. 

Patronite, a sulphide of vanadium, forms a large deposit at one locality 

in Peru.

Xenon. An -inert gas, a member of the argon group. Found 

in minute traces in the atmosphere.

Yttrium and ytterbium. Two rare-earth metals, which, with lutecium/ erbium, and terbium, are best obtained from gadolinite. 

Yttrium is also found in the phosphate, xenotime, in several silicates, 

and in some of the columbo-tantalate group of minerals. The minerals of the rare earths are generally found in granite or pegmatite 

veins.

Zinc. Common and rather widely diffused. Native zinc has been 

reported, but its existence is doubtful. The sulphide, sphalerite, is 

its commonest ore, but the carbonate, smithsonite, and a silicate, 

calamine, are also abundant. At Franklin, New Jersey, zinc is found 

in a unique deposit, in which the oxide, zincite; the ferrite, franklinite; and the silicates, troostite, and willemite, are the characteristic ores.

Zirconium. Allied to titanium and rather widely diffused in the 

igneous rocks. It usually occurs in the silicate, zircon.

1 The old ytterbium, the ytterbium of the first edition of this work, has been proved to bo complex 

by G. Urbain and Auer von Welsbach, working independently. The two components of the former ytterbium are by Urbain named neoytterbium and lutecium. For these Welsbach proposes the names aidebaranium and cassiopeium. The name ytterbium is here retained for the main component of the mixture 

and lutecium for the other, as having priority over its synonym.
22- DATA OF GEOCHEMISTRY.

. RELATIVE ABUNDANCE OF THE. ELEMENTS.

In any attempt to compute the relative abundance of the chemical 

elements, we must bear in mind the limitations of our experience. 

Our knowledge of terrestrial matter extends but a short distance 

below the surface of the earth, and beyond that we can only indulge 

in speculation. The atmosphere, the ocean, and a thin shell of solids 

are, speaking broadly, all that we can examine. For the first two 

layers our information is reasonably good, and their masses are 

approximately determined; but for the last one we must assume 

some arbitrary' limit. The real thickness of the lithosphere need not 

be considered; but it seems probable that to a depth of 10 miles 

below sea level the rocky material can not vary greatly from the 

volcanic outflows which we recognize at the surface. This thickness 

of 10 miles, then, represents known matter, and gives us a quantitative basis for study. A shell only G miles thick would barely clear 

the lowest deeps of the ocean.

I am indebted to Dr. R. S. Woodward for data relative to the 

volume of matter which is thus taken into account. The volume of 

the 10-mile rocky crust, including the mean elevation of the continents 

above the sea, is 1,633,000,000 cubic miles, and to this material we 

may assign a mean density not lower than 2.5 nor much higher 

than 2.7. The volume of the ocean is put at 302,000,000 cubic 

miles,1 and I have given it a density of 1.03, which is a trifle too high. 

The mass of the atmosphere, so far as it'can be determined, is equivalent to that of 1,268,000 cubic miles of water, the unit of density. 

Combining these data, we get the following expressions for the composition of the known matter of our globe:

Composition of knoivn matter of the earth.

Atmosphere ......................

Solid crust. ....................... ....................do....

2.5

"0. 03

7.08

92.89

100. 00

2.7

0.03

G. 58

Q3 3Q

100. 00

In short, we can regard the surface layer of the earth, to a depth 

of 10 miles, as consisting very nearly of 93 per cent solid and 7 per 

cent liquid matter, treating the atmosphere as a small correction to

i Sir John Murray (Scottish Geog. Mag., 1888, p. 39) estimates tlio volume of the ocean at 323,722,150 

cubic miles. K. Karstens, more recently (Erne neue Berechnung der mittlcrcn Tiefcn der Oceanc, InaugBiss., Kiel, 1894), put it at 1,235,935,211 cubic kilometers, or 307,496,000 cubic miles. Karstens gives a good 

summary of previous estimates, which vary widely. According to. 0. Krummel, the volume is 319,087,500 

cubic miles (Encyc. Britannica, llth ed., vol. 19, p. 974). To change the figure given in the text would 

be straining after unattainable precision.
THE CHEMICAL ELEMENTS. 23

be applied-when needed.1 The "figure thus assigned to- the ocean is 

probably a little too high, but its adoption makes an allowance for 

the fresh waters of the globe, which are too small in amount to be 

estimable directly. Their insignificance may be inferred from the 

fact that a section of the 10-mile crust having the surface area of 

the United States represents only about 1.5 per cent of the entife 

mass of matter under consideration. A quantity of water equivalent 

to 1 per cent of the ocean, or 0.07 per cent of the matter now considered, would cover all the land areas of the globe to a depth of 

290 feet. Even the mass of Lake Superior thus becomes a negligible 

quantity. The significance of underground waters will be discussed 

later.

The composition of the ocean is easily determined from the data 

given by Dittmar in the report of the Challenger expedition.2 The 

maximum salinity observed by him amounted to 37.37 grams of salts 

hi a kilogram of water, and by taking this figure instead of a lower 

average value we can allow for saline masses inclosed within the 

solid crust of the earth, which would not otherwise appear in the 

final estimates. Combining this datum with Dittmar's figures for 

the average composition of the oceanic salts, we get the second of 

the subjoined columns. Other elements contained in sea water, but 

only in minute traces, need not be considered here. No one of them 

could reach 0.001 per cent.

Composition of oceanic salts. 

NaCl... ...................'......

MgCL,... ........................

MgS04 .. ........ ..................

OaS04 .. ..........................

K2S04 .. ...........................

MgBra .. ..........................

CaCOa ..... ......................

77.76

10.88

4.74

3.60

2.46

.22

.34

100. 00

0.....

H...,.

01....

Na....

Mg....

Ca....

K.....

Br....

C.....

Composition of ocean.

. 85.79

. 10. 67

. 2. 07

. 1.14

. .14

. .05

. .04

. .008

. .002

100. 00

It is worth while at this point to consider how large a mass of 

matter these oceanic salts represent. The average salinity of the 

ocean is not far from 3.5 per cent; its mean density is 1.027, and its 

volume is 302,000,000 cubic miles. The specific gravity of the salts, 

as nearly as can be computed, is 2.25. From these data it can be 

shown that the volume of the saline matter in the ocean is a little 

more than 4,800,000 cubic miles, or enough to cover the entire surface

1 The adoption of Murray's figure for the volume of the ocean would make its percentage 7.12 to 7.88 

according to the density (2.5 or 2.7) assigned to the lithosphere.

2 In vol. 1, Physics and chemistry.
24 DATA OF GEOCHEMISTRY.

of the United States, excluding Alaska, 1.6 miles deep. 1 In the face 

of these figures, the beds of rock salt at Stassfurt and elsewhere, 

which seem so enormous at close range, become absolutely trivial. 

The allowance made for them by using the maximum salinity of the 

ocean instead of the average is more than sufficient, for it gives them 

a total volume of 325,000 cubic miles. That is, the data used for 

computing the average composition of the ocean and its average 

significance as a part of all terrestrial matter are maxima, and therefore tend to compensate for the omission of factors which could not 

well be estimated directly.

The average composition of the lithosphere is very nearly that of 

the igneous rocks alone. The sedimentary rocks represent altered 

igneous material, from which salts have been leached into the ocean, 

and to which oxygen, water, and carbon dioxide have been added 

from the atmosphere. For these changes corrections can be applied, 

and their magnitude and effect, as will be shown later, is surprisingly 

small. The thin film of organic matter upon the surface of the earth 

can be neglected altogether. In comparison with the 10-mile thickness of rock below it, its quantity is too small to be considered. Even 

beds of coal are negligible, for their volume also is relatively insignificant. Practically, we have to consider at first only 10 miles of 

igneous rock, which,, when large enough areas are studied, averages 

much alike in composition all over the'globe. This point was established in an earlier memoir, when groups of analyses, representing 

rocks from different regions, were compared.2 The essential uniformity of the averages was unmistakable, and it has been still further emphasized in later computations by others as well as by myself.

To this method of averaging one serious objection has been raised. 

All analyses are given equal weight, without regard- to the areas 

occupied by the various rocks and therefore to their relative abundance. One rock, say a granite, is exceedingly abundant; another 

may be represented by one small dike. The inequality is obvious, 

but what does it really signify ? In the first place the relatively 

insignificant rocks vary in composition from persilicic to subsilicic just 

as the most abundant rocks do. In the average they tend to compensation, and so to approximate to the true mean. Furthermore, 

the surface exposure of a rock is no certain measure of its real volume 

and mass, for it may be merely the peak or crest of a large subterranean formation.

i According to J. Joly (Sci. Trans. Roy. Soc. Dublin, 2d ser., vol. 7, 1899, p. 30), the sodium chloride in 

the ocean would cover the entire globe 112 feet deep. If Krummel's figure for the volume of the ocean is 

taken, the volume of the salts becomes approximately 5,100,000 cubic miles.

s Bull. Philos. Soc. Washington, vol. 11,1889, p. 131. Also in Bull. U. S: Geol. Survey No. 78,1891, p. 34. 

Alater and more complete table is given in Proe. Am. Philos. Soc., vol. 51, p. 214,1912.
THE CHEMICAL ELEMENTS. 25

A good test of the validity of such averages as I have used is 

furnished by the work of R. A. Daly. 1 Daly has made separate 

averages of analyses of more than twenty rock types and has also 

measured the areas which rocks of these types occupy as shown on 

the geologic maps of the United States Geological Survey. He also 

shows that the mean composition of an average granite combined 

with that of an average basalt is almost identical with the average 

given by Washington for 1,811 analyses of igneous rocks from all 

parts of the world. W. J. Mead,2 applying a peculiar graphic method 

to some of Daly's data, concludes that a mixture of 65 per cent of 

the average granite with 35 per cent of the average basalt will have a 

composition very close to the general average of all igneous rocks as 

computed by me. A similar result is reached by F. LoewinsonLessing,3 who regards the crust of the earth as derived from two 

fundamental magmas, one granitic and one gabbroid. These are 

supposed to have existed in about equal proportions, and their mean 

composition is nearly that found for all the igneous rocks by Washington and by me. A still better verification. of these converging 

conclusions is due to A. Knopf,4 who has taken Daly's averages, for 

the composition of the individual rock types, weighted each one by 

its area as determined by Daly, and then combined the values so 

found into a general mean.

The following averages are now available for comparison:

A. An average of all the analyses of igneous rocks, partial or complete, made up to 

October 1, 1918, in the laboratories of the Survey.

B. An average, computed by A. Harker,8 of 536 analyses of igneous rocks from 

British localities. Many of these analyses were incomplete, especially with respect 

to phosphorus and titanium.

C. An average of 1,811 analyses, from Washington's tables.6 Calculated by H. S. 

Washington. The data represent material from all parts of the world.

D. The average found by Knopf.

Now, omitting minor constituents, which rarely appear except in 

the more modern analyses, these averages may be tabulated together, 

although they are not absolutely comparable. The comparison 

assumes the following form:

1 Igneous rocks and their origin, New York, 1914, pp. 19-46, 168-170. See also his preliminary paper, 

Proc. Am. Acad., vol. 45,1910, p. 211,

2 Jour. Geology, vol. 22,1914, p. 772.

»Geol. Mag.,1911, p. 248.

< Jour. Geology, vol. 24,1916, p. 620.

» Tertiary igneous rocks of the Isle of Skye: Mem. Geol. Survey United Kingdom, 1904, p. 416. An 

earlier average appears in Geol. Mag., 1899, p. 220.

« Prof. Paper U. S. Geol. Survey No. 14,1903, p. 108. In this average, and also in Barker's and Knopf's, 

there are figures for manganese, which J leave temporarily out of account. On the average composition 

of Minnesota rocks see F. F. Grout, Science, vol. 32,1910, p. 312.
26 DATA OF GEOCHEMISTRY.

Average composition of igneous rocks.

Si02 . .................................

A1203 . ................................

FpO F^V:::::.:::::::::::::::::::::::::::

MgO. .................................

CaO..................................

Na,O.................................

K20. .................... .....~........

H2OatlOO°...........................

H20 above 100° ........................

Ti02 ........ .......................... P f\ . . rau6 ..................................

A

60.88

15.27

2.67

3.49

3.82

4.92

3.43,

3.10

.49

1.45

.81

.29

100. 62

B

5S..98

15. 41

4.78

2.70

3.71

- 4.83

3.18

2.77

} 2.17

.52

.21

99.26

C

58. 539

15. 796

3.334

3.874

3. 843

5.221

3.912

3.161

.363

1. 428

1.039

.373

100. 583

D

61.64

15.71

9 Ql

3.. 25

2.97

5.06

3.40

2,65

1 1.26

.73

.26

99.84

Although these four columns are not very divergent, they exhibit 

differences which may be more apparent than real. Differences of 

summation are due partly to the omission of minor constituents, 

but the largest variations are attributable to the water. In two 

columns hygroscopic, water is not distinguished from combined 

water; in two a discrimination is made. By rejecting the figures 

for water and recalculating to 100 per cent the averages become 

more nearly alike, as follows:

Average composition of igneous woks, reduced to 'uniformity.

SiOo........... ........................

AljOg.i.............. :.....'. ..........

Fe203 ...................... ............

Feb..................................

MgO...................................

CaO...................................

Na.,0. .................................

KaO..................... .............

TiO

P O

A

61. 69

15. 47

2, 71

3.54

3. 87

4.98

3.48

3.14

.82

.30

100. 00

B

60.76

15.87

4.92

2.78

3.82

4.97

3.28

2.85

KO

.22

100. 00

0

58. 96

15.99

3.37

3.93

3.89

5.28

3.96

3.20

1 ftfi

.37

100. 00

D

62.52

15.93

2.95

3.30

3.01

5.14

3.45

2.69

.74

.27

100. 00

Of these averages A and C include the largest number of trustworthy analyses. They are, however, not strictly equivalent in 

character. Washington's average relates only to analyses which 

were nominally complete and made in many laboratories by very 

diverse methods. My average represents the homogeneous work of 

one laboratory, and includes, moreover, many partial determinations. For the simpler salic rocks determinations of silica, lime,
THE CHEMICAL ELEMENTS. 27

^, and alkalies are generally all that is needed for petrographic puri poses. The femic rocks are mineralogically more complex, and

for them full analyses are necessary. The partial analyses, there-

' fore, represent chiefly salic rocks, and their inclusion in the average

' tends to raise the percentage of silica and to lower the proportions 

of other elements. The salic rocks, however, are more abundant 

than those of the other class, and so the higher figure for silica seems 

more probable, a supposition which is reinforced by Knopf's average. 

This conclusion is also in line with the criticisms of F. P. Mennell/ who thinks that the femic rocks received excessive weight 

in my earlier averages. Mennell has studied the rocks of southern 

Africa, where granitic types are predominant, and believes that the 

true average should approximate the composition of a granite. His 

criticisms are entitled to serious consideration, but they are not

: absolutely conclusive. A study of the composition of river waters

' originating in areas of crystalline rocks reveals a preponderance of 

calcium over alkalies which waters from purely granitic environment 

could hardly possess. Granitoid rocks, such, for example, as quartz

* monzonite, are also abundant, and the average composition is likely 

to be near that of a diorite or andesite.2 The whole land surface of 

the earth must be taken into account before the true average can be 

finally ascertained.

/' So far, the final average has only been partly given; the minor 

constituents of the rocks remain to be taken into account. In the 

laboratory of the Geological Survey the analyses of .igneous rocks 

have been unusually elaborate, and many things have been determined that are too often ignored. The complete average is given 

in the next table, with the number of determinations to which each 

figure corresponds. In the elementary column hygroscopic water 

does not appear, but an allowance is made for a small amount of 

iron which was reported in the analyses as FeS2 . When a "trace" 

of anything is recorded, it is arbitrarily reckoned as 0.01 per cent, 

' and when a substance is known to be absent from a rock, by actual 

determination of the fact, it is assigned zero value in making up the 

averages.3

1 Geol. Mag., 1904, p. 263; 1909, p. 212. For other discussions or the data given in my former papers, see 

L. Do Launay, Revuegdn. sci., Apr. 30,1904: and C. Ochsonius, Zeitschr. prakt. Geologic, May, 1S98. Compare also R. A. Daly (Bull. U. S. Geol. Survey No. 209, 1903, p. 110), who argues that the universal or 

C fundamental magma is approximately basaltic.

2 On the mean atomic weight of the earth's crust,.see L. Do Launay, Compt. Rend., vol. 150, 1910, p. 

j 1270. See also A. E. Fersmann (Bull. Acad. St. Petersburg, 1912, p. 367) for a calculation of the atomic 

percentages of the more important rock-forming elements.

3 In this table all analyses of igneous rocks made in the laboratory of the Survey down to October 1,1918, 

have been utilized.
28 DATA OF GEOCHEMISTRY.

Average composition of igneous rocks in detail.

Si02 . ................

A1203 - --------------

Fe203 - ...............

FeO

MgO. ................

CaO.................

Na,0................

K20.... ..............

H20-. ...............

H20+. ...............

Ti02 . ................

Zr02 . ................

CO...................

P O

s?.v.::::::::::::::::

Cl. ...................

F.. ...................

BaO.. ...............

SrO..................

MnO.................

NiO.................

Cr20,.. ...............

vao3 .... ..............

Li,0.................

Number 

of determinations.

1,789 

1,252 

1,298 

1,291 

1,387 

1,633 

1,703 

1,696 

965 

1,012 

1,193 

399 

772 

1,179 

845 

265 

112 

823 

675 

1, 198 

307 

303 

111 

587

Average.

60.88 

15.27 

2.67 

3.49 

3.82 

4. 92 

3.43 

3.10 

.49 

1.45 

.81 

.023 

.50 

.29 

.10 

.064 

.10 

.104 

.043 

.10 

.026 

.049 

.026 

.011

101. 766

Reduced to 

100 per cent.

59.83 

15.02 

2.62 

3.43 

3.74 

4.83 

3.37 

3.05 

.48 

1.42 

.79 

.023 

. .49 

.29 

.10 

.063 

.10 

.10 

.043 

.10 

.026 

.048 

.026 

.011

100. 000

In elementary form.

0.............

Si..............

Al... ..........

Fe

Mg............

Ca............

ATfl

K. ............

H. ............

Ti............

Zr. ...........

C. ............

P..............

S...... ........

Cl.............

F.... ..........

Ba. ...........

Sr.............

Mn............

Ni. ........:..

Cr............

v.............

Li.............

47.29 

28.02 

7.96 

4.56 

2.29 

3.47 

2.50 

2.47 

.16 

.46 

.0.17 

.13 

.13 

.10 

.063 

.10 

.093 

.034 

.078 

.020 

.034 

.017 

.004

100. 000

In this computation the figures for C, Zr, Cl, F, Ni, Cr, and V are 

probably a little too high. They show, however, that these elements 

exist in igneous rocks in determinable quantities. Fluorine, however, 

exists in rocks chiefly in the mineral apatite, and its proportion can 

be determined with much probability from the percentage of phosphorus. Computing from that datum, the percentage of fluorine becomes only 0.027, or little more than one-fourth of the figure given 

in the table. As for carbon, its probable excess may be allowed to 

stand, as a compensation, in our final reckoning, for the otherwise 

undeterminable quantities represented by coal and petroleum. TJie 

elements not included in the calculation represent minor corrections, 

to be applied whenever the necessity for doing so may arise. For 

estimates of their probable amounts, the papers by J. H. L. Vogt 1 

and J. F. Kemp 2 can be consulted. A few more definite estimates 

have been made by Clarke and Steiger 3 from careful analyses of

i Zeitschr. prakt. Geologic, 1898, pp. 225, 314, 377, 413; 1899, pp. 10, 274.

»Science, Jan. 5, 1906; Econ. Geology, vol. 1,1905, p. 207. See also a curious paper by W. Ackroyd, in 

Chem. News, vol. 86,1902, p. 187. W. N. Hartley and H. Ramage (Jour. Chem. Soc., vol. 71,1S97, p. 533) 

nave shown that some of the rarest elements, such as gallium and indium, are widely diffused in rocks and 

minerals. W. Vernadsky (Chem. Zentralbl., vol. 2, 1910, p. 1775) has also found that indium, thallium, 

gallium, rubidium, and ctesium are widely distributed in spectroscopic traces. Vernadsky (Centralbl. 

Min., Geol. u. Pal., 1912, p. 758) has also studied the occurrence of native elements in the earth's crust.

8 Jour. Washington Acad. Sci., vol. 4, p. 57, 1914.
THE CHEMICAL ELEMENTS. 29

large composite samples of rocks and clays. The average percentages are as follows: CuO, 0.0130; ZnO, 0.0049; PbO, 0.0022; As205» 

0.0005. These figures, considered as orders of magnitude, have a 

high degree of probability. The remaining elements not mentioned 

here nor in the table can not amount to more than 0.5 per cent altogether, and even that small figure is likely to be an overestimate. 

Before we can finally determine the composition of the lithosphere, 

the sedimentary rocks are to be taken into account; and to do this we 

must ascertain their relative quantity. First, however, we may consider their composition, which has been determined by means of composite analyses. That is, instead of averaging analyses, average 

mixtures of many rocks were prepared, 1 and these were analyzed once 

for all. The results appear in the next table.

Composite analyses of sedimentary rods.

A. Composite analysis of 73 shales; or, more strictly, the average of two smaller composites, properly 

weighted.

B. Composite analysis of 253 sandstones. 

C. Composite analysis of 345 limestones.

sioa ............................................

A1203 - ------------------------------------------

Fe203 - ..........................................

FeO

MgO. . ..........................................

CaO. ...............................................

Na20...........................................

K2 0.............................................

H20 at 110° .....................................

H20 above 110°.. . ...............................

TiOt.. ..........................................

co2 ..................................\..........

p o

if??::::::::::::::::::::::::::::::::::::::::::::

so3 .. .......................................... ci................ ...............................

BaO. ...........................................

SrO.............................................

MnO. ...........................................

Li2 0. ...........................................

C, organic .......................................

A

58.38

15. 47

 4.03

2.46

2.45

3.12

1.31

3.25

1.34

3.68

.65

2.64 '.17

.65

.05

Trace.

Trace.

.81

100. 46

B

78.66

4.78

1.08

.30

1.17

5.52

AK.

1.32

.31

ol.33

.25

5.04

.08

.07

Trace.

.05

Trarp

Trace.

100. 41

C

5.19

.81

}

KJL

7.90

42.61

.05

.33

.21

a. 56

.06

41. 58

.04

.09

.05

.02

"MnTif*

.05

TYnrn

100. 09

a Includes organic matter.

In attempting to compare these analyses with the average composition of the igneous rocks, we must remember that they do not represent definite substances, but mixtures shading into one another. The 

average limestone contains some clay and sand; the average shale

1 These mixtures were prepared, under the direction of G. K. Gilbert. The analyses were made by 

H. N. Stokes in the laboratory of the U. S. Geological Survey. See Bull. U. S. Geol. Survey No. 223,1904. 

.P. 20.
30 DATA OF GEOCHEMISTRY.

contains some calcium carbonate. Furthermore, they do not cover 

all the products derived from the decomposition of the primitive 

rock, for the great masses of sediments on.the bottom of the ocean 

are left out of account. There are also metamorphic rocks to be 

considered, such as chloritic and talcose schists, amphibolites, and 

serpentines; although their quantities are presumably too small 

to seriously modify the final averages. They might, however, help 

to explain a deficiency of magnesium which appears in the sedimentary analyses. Partly on account of these considerations, and partly 

because the sedimentary rocks contain water and carbon dioxide 

which have been added to the original igneous material, we can not 

recombine the composite analyses so as to reproduce exactly the composition of the primitive matter.1 To do this it would be necessary 

also to allow for the oceanic salts, which represent, in part, at least, 

losses from the land; but that factor in the problem is perhaps 

the least embarrassing. Its magnitude is easily estimated, and it 

gives a measure of the extent to which the igneous rocks have been 

decomposed.

If we assume .that all the sodium in the ocean was derived from 

the leaching of the primitive rocks, and that the average composition 

of the latter is correct as stated, it is easy to show that the marine 

portion is very nearly one-thirtieth of that contained in the 10-mile 

lithosphere. That is, the complete decomposition of a shell of igneous 

rock one-third of a mile thick would yield all the sodium in the 

ocean. Some sodium, however, is retained by the sediments, and the 

analyses show that it is about one-third of the total amount. That 

is, the oceanic sodium represents two-thirds of the decomposition, 

and the estimate 1 must therefore be increased one-half. On this 

basis, a rocky shell one-half mile thick, completely enveloping the 

globe, would slightly exceed the amount needed to furnish the 

sodium of the sea and the sediments.

In order to make this estimate, more precise, let us consider the 

detailed figures. The maximum allowance for the sodium in the 

ocean is 1.14 per cent. From my average the mean percentage of 

sodium in the igneous rocks is 2.50; Washington's figures give 2.90. 

Now, putting the ocean at 7 per cent and the lithosphere at 93 per 

cent of the known matter, the following ratios between oceanic 

sodium and rock sodium are easily computed: Clarke, 1:29.8; 

Washington, 1 :33.9. Hence, the sodium in the ocean corresponds 

to a volume of igneous rocks, according to the first ratio, of 54,800,000 

cubic miles or, for the second estimate, of 48,200,000 cubic miles.

Suppose, however, that the average analyses do not represent the 

true composition of the primitive lithosphere. We may then test

1 For an elaborate attempt in this direction see C. B. Van Hise, A treatise on metamorphism; Mon. 

U. S. Geol. Survey, vol. 47, pp. 947-1002, 1904. See also W. J. Mead, Jour. Geology, vol. 22, p. 772, 1914
THE CHEMICAL ELEMENTS. 31

our figures by another assumption, namely, that the real average 

lies somewhere between two evident extremes the composition of 

a rhyolite and that of a basalt. In 100 rhyolites, as shown in Washington's tables, the average percentage of sodium is 2.58, while for 

220 basalts it is 2.40. These figures give ratios of 1: 30.1 and 1: 28.4, 

corresponding to rock volumes of 54,200,000 and 57,500,000 cubic 

miles, respectively quantities of quite the same order as those 

previously calculated.

From the composite analyses of the sedimentary rocks the correction for their retained sodium can be determined. This sodium is 

chiefly, but not entirely, in the shales, and its amount is less than 

1 per cent, with a probable value of 0.900 This is 35 per cent of the 

total sodium in the average igneous rock, and the oceanic sodium 

represents the 65 per cent removed by leaching. Allowing for this 

sedimentary sodium, the total sodium of the ocean and of the sedimentary rocks is represented by the ratio of

65 : 100 = 54,800,000 : 84,300,000,

the last term giving the number of cubic miles of igneous rock which 

has undergone decomposition. This quantity is that of a rock shell 

completely enveloping the globe and 0.4215 mile, or 2,225 feet, thick. 

If we accept the highest ratio of all, that furnished by the average 

basalt, the thickness may be raised to 2,336 feet, while Washington's data will give a much lower figure. A further allowance of 10 

per cent, which is excessive, for the increase in volume due to oxidation, carbonation, and absorption of water will raise the thickness 

assignable to the sedimentaries from 2,225 to 2,447 feet, an amount 

still short of the half-mile estimate. No probable change in the composition of thelithosphere can modify this estimate very considerably; 

and since the ocean may contain primitive sodium, not derived from 

the rocks, the half mile must be regarded as a maximum allowance. 

If the primeval rocks were richer in sodium than those of the present 

day, a smaller mass of them would suffice; if poorer, more would be 

needed to account for the salt in the sea. Of the two suppositions, the 

former is the more probable; but neither assumption is necessary. If, 

however, we assume that our igneous rocks are not altogether primary but that some of them represent re-fused or metamorphosed 

sedimentaries, we must conclude that they have been partly leached 

and have therefore lost sodium. That is, the original matter was 

richer in sodium, and the half-mile estimate is consequently much 

too large.

From another point of view, the thinness of the sediments can be 

simply illustrated. The superficial area of the earth is 199,712,000 

square miles, of which 55,000,000 are land. According to Geikie,1 the

i Textbook of geology, 4th cd., vol. 1, p. 40, 1903.
DATA OF GEOCHEMISTRY.

mean elevation of all the continents is 2,411 feet. Hence, if all the 

land now above sea level, 25,000,000 cubic miles, were spread uniformly over the globe, it would form a shell about 660 feet thick. If 

we assume this matter to be all sedimentary, which it certainly is not, 

and add to it any probable allowance for the sediments at the bottom 

of the sea we shall still fall far short of the half-mile shell which, on 

chemical evidence, is a maximum. In the following calculation this 

maximum will be taken for granted.

The relative proportions of the different sedimentary rocks within 

the half-mile shell can only be estimated approximately. Such an 

estimate is best made by studying the average igneous rock and determining in what way it can break down, A statistical examination of 

about 700 igneous rocks, which have been described petrographically, 

leads to the following rough estimate of their mean mineralogical 

composition:

Quartz......................................................... 12.0

Feldspars...................................................... 59.5

Hornblende and pyroxene..................................... 16.8

Mica.......................................................... 3.8

Accessory minerals............................................. 7.9

100.0

The average limestone contains 76 per cent of calcium carbonate, 

and the composite analyses of shales and sandstones correspond to 

the subjoined percentages of the component minerals:

Average composition of shale and sandstone.

Quartz a ..................................................

Feldspar. ..................................................

Clay &....................................................

Carbonates. ................................................

Other minerals. ............................................

Shale.

22.3

30.0

25.0

5.6

K 7

11.4

100.0

Sandstone.

66.8

11.5

6.6

1.8

11.1

9 9

100.0

o The total percentage of free silica.

6 Probably sericite in part. In that case the feldspar figure becomes lower.

If, now, we assume that all of the igneous quartz, 12 per cent, has 

become sandstone, it will yield 18 per cent of that rock, which is 

evidently a maximum. Some quartz has remained in the shales. 

One hundred parts of the average igneous rock will form, on decomposition, less than 18 parts of sandstone.

The igneous rocks contain, as shown in the last analysis cited, 4.84 

per cent of lime. This would form 8.65 per cent of calcium carbonate, or 11.2 per cent of an average limestone. But at least half of
THE CHEMICAL ELEMENTS. 33

the lime has remained in the other sediments, so that its true proportion can not reach 6 per cent, or one-third the proportion of the 

sandstones. The remainder of the igneous material, plus some water 

and minus oceanic sodium, has formed the siliceous residues which 

are grouped under the vague title of shale. Broadly, then, we may 

estimate that the lithosphere, within the limits assumed in this memoir, contains 95 per cent of igneous rock and 5 per cent of sedimentaries. If we assign 4.0 per cent to the shales, 0.75 per cent to the 

sandstones, and 0.25 per cent to the limestones, we shall come as near 

the truth as is possible with the present data. 1 On this basis, the 

average composition of the lithosphere may be summed up as shown 

in the following table. The analyses of the sedimentary rocks are 

recalculated to 100 per cent.

Average composition of the lithosphere.

SiOa .......................

A12 03 . .....................

Fe203 ......................

FeO........................

MgO. ......................

CaO. ......................

Na20......................

K20. .......................

H2 0. .-- - - ...............

TiOa . ......................

ZrOa . ......................

rn

p ?2(1 v5 . ......................

<sn

ci..........................

F. ..........................

BaO.......................

SrO........................

MnO. ......................

NiO.......................

Cra08 ......... .............. VA......... ...............

Li20. ......................

C. .........................

Igneous 

(95 per 

cent).

59.83

15.02

2.62

3.43

3.74

4.83

3.37

3.05

1.90

.79

.023

.49

9Q

.10

.003

.10

.10

.043

.10

.026

.048

.026

.011

100. 000

Shale (4 per 

cent).

58.10

15.40

4.02

2.45

2.44

3.11

1.30

3.24

5.00

.65

O ftO

.17

.64

AK

.80

100. 00

Sandstone 

(0.75 per 

cent).

78.33

4.77

1.07

.30

1.16

5.50

.45

1.31

1.63

.25

5.03

.08

.07

.05

100. 00

Limestone 

(0.25 per 

cent).

5.19

.81

.54

7.89

42.57

.05

.33

.77

.06

41 PU.

.04

OQ

.05

09

.05

100. 00

Weighted 

average.

59.77

14.89

2.69

3.39

3.74

4.86

3.25

2.98

9 09

.77

02

.70

OQ

.10

.03

.06

OQ

OQ

04

OQ

HOP;

.05

noc

.01

03

300. 00

The final average differs from that of the igneous rocks alone only 

within the limits of uncertainty due to experimental errors and to the

*C. R. Van Hise (A treatise on metamorphism: Mon. U. S. Geol. Survey, vol. 47,1904, p. 940) divides 

the sedimentary rocks into 65 por cent shales, including all pelites and psephites, 30 per cent sandstones, 

and 5 per cent limestones. W. J. Mead (Jour. Geology, vol. 15, 1907, p. 238), by a graphic process, distributes the sedimentaries into 80 per cent shales, }1 por cent sandstones, and 9 per cent limestones. In a 

later paper (Jour. Geology, vol. 22, p, 772,1914) Mead modifies this estimate somewhat.

113750° 19 Bull. 695 3
34 DATA OF GEOCHEMISTRY. '

assumptions made as to the relative proportions of the sedimentaries. 

The values chosen for the sediments are approximations only, and 

nothing more can be claimed for them. They seem to be near 

the truth as near as we can approach with data which are necessarily 

imperfect and so they may be allowed to stand without further 

emendation.

In the preceding table the hygroscopic water of the igneous rocks 

is taken into account, but so far the underground waters have been 

neglected. For this omission the hygroscopic water may partly 

compensate, but the subject demands a little closer attention. 

Extravagant estimates of the quantity of underground water have 

been made, based upon the fact that all rocks are more or less porous.1 

Van Hise, however, claims that the pore spaces below a depth of 6 

miles are probably closed by the pressure of the superincumbent 

strata; a consideration which must not be ignored. Van Hise 

estimates the volume of the underground waters to a depth of 10,000 

meters as equal to that of a sheet covering the continental areas 69 

meters or 226 feet deep. Fuller's estimate is more complete, for it 

involves a discussion of the relative quantities and average porosities 

of the sedimentary and igneous rocks, and he concludes that the 

volume of subterranean water is about one one-hundredth that of 

the ocean. These conclusions require some modification; for 

Adams, by experiments upon the compression of granite, has shown 

that porosity may exist to a depth of at least 11 miles. In any case 

the quantity of water is negligible, for, added to the volume of the 

hydrosphere it would not appreciably affect the final computation. 

The proportion of water in known terrestrial matter would be increased by less than 0.1 per cent. . With the data now before us we are in a position to compute the 

relative abundance of the chemical elements in all known terrestrial 

matter. For this purpose, the composition of the lithosphere is 

restated in elementary form, with an arbitrary allowance of 0.5 per 

cent for all the elements not specifically named. As for the atmosphere, 0.03 per cent, it is represented in the final results as if it were 

all nitrogen; an exaggeration which allows for the traces of nitrogen, 

rarely determined, that are present in the rocks.2 The mean com-

* See A. Dolesse, Bull. Soc. ge"ol. France, vol. 29,1861, p. 64; J. D. Dana, Manual of geology, 4th ed., 1895, 

p. 209; W. B. Greenleo, Arn. Geologist, vol. 18, 1890, p. 33; O. Seller, Annales des mines, 9th ser., vol. 

12', 1S97, p. 32; C. S. Slichter, Water-Supply Paper TJ. S. Geol. Survey No. 67, 1902, p. 14; T. C. Chamberlin and R. D. Salisbury, Geology, vol. 1,1904, p. 209; C. R. Vau Hiso, A treatise on inetamorphism: 

Hon. TJ. S. Geol. Survey, vol. 47, 1904, p. 129; 11. L. Fuller, Water-Supply Paper U. S. Geol. Survey 

No. 100,1900, p. 59; F. D. Adams, Jour. Geology, vol. 20,1912, p. 97. See also an address by J. F. Kemp, 

Trans. Am. Inst. Min. Eng., vol. 14,1914, p. 3.

s Sea A. D. Hall and N. J. II. Miller (Jour. Agr. Sei., vol. 2, p. 313) en nitrogen in unvreathered sedimentary rocks. From 0.04 to 0.107 per cent was found. H. Erdmann (Ber. Deutsch. chem. Gesell., vol. 29, 

1898, p. 1710) found traces of nitrogen in several rare minerals from pegmatite. In a later paper, in Arbeiten 

auf don Gebioten der Gross-Gasindustrio, No. 1,1909, Erdmann computes that each square meter of land, 

to a depth of 15 kilometers, contains 5 metric tons of nitrogen. The total amount of nitrogen in the rocks 

is much less than that in the atmosphere alone.
THE CHEMICAL ELEMENTS.

position of the lithosphere, the hydrosphere, and the atmosphere, 

. then, is as follows:

Average composition of known terrestrial mailer.

Oxygen... ................. . v .. ..........

Silicon ...................................

Iron .....................................

Magnesium ...............................

Sodium ....................................

Potaspium ................................

Hydrogen

Titanium ................................

Carbon. ...................................

Bromine .................................

Phosphorus ...............................

Sulphur. ....................................

Barium ..................................

^!lan£rancs6

Nitrogen ..................................

Fluorine. ................................

Lithosphero, 

93 per cent.

47.33

27.74

7.85

4.50

3.47

2.24

2.46

2.46

.22

.46

.19

.06

.12

.12

.08

.08

.02

.10

.50

100. 00

Hydrosphere, 

7 per cent.

85,79

.05

.14

1.14

.04

10.67

.002

2.07

.008

nq

100. 000

Average, including atmosphere.

50.02

25.80

7.30

4.18

3 99

9 fift

9 3ft

2.28

.95

.43

.18

.20

.11

.11

.08

no

.02

rt^

.10

.47

100. 00

The briefest scrutiny of the foregoing tables will show that in 

the lithosphere the lighter elements predominate over the heavier. 

All the abundant elements fall at or below atomic weight 56, and 

above that, in the analysis given on page 28, only nickel, zirconium, 

strontium, and barium appear. The heavy metals, as a rule, occur 

in apparently trivial quantities. Since, however, the mean density 

of the earth is about double that of the rocks at its surface, it has 

sometimes been supposed that the heavier substances may be concentrated in its interior, a supposition which is possibly true, but 

unprovable. If the globe is similar in constitution to a meteorite, we 

should expect iron and nickel to be abundant in its mass as a whole; 

but this, after all, is nothing more than a suspicion. One fact only 

seems to shed a clear light upon the problem. A mixture of all the 

elements, in equal proportions by weight and in the free state, 

would have a density greater than that of the earth. Combination 

would increase the density of the mixture, and the effect of internal 

pressure would make it greater still. It is therefore plain that in 

the earth as a whole, whatever may be the composition or condition 

of its interior, the lighter elements are more abundant than the 

denser. Thus far wo can go, but no farther. Of the actual proportions we know nothing.
36 DATA OF GEOCHEMISTRY.

THE PERIODIC CjLASSIFICATION.

Although the chemical elements are analytically distinct, they are 

by no means unrelated. On the contrary, they fall into a number of 

natural groups; and within each one of these the members not only 

form similar compounds, but also exhibit, as a rule, a regular gradation of properties. This relationship has led to an important generalization the periodic law, or, more precisely, the periodic classification of the elements and in its light some of their associations 

become extremely suggestive.

When the elements are tabulated in the order of their atomic 

weights, the periodicity shown in the following scheme at once becomes evident. The metals of the rare earths, with atomic weights 

between those of cerium and tantalum, are omitted, because of 

uncertainties as to their true relation.
Periodic classification of the elements.

Series.

1.....

2.....

3.....

4.....

5.....

7.....

10

11.....

12

Group 0.

He-4

Ne-20. 2

A-39.9

"K~r R9 Q

Xe-130.2

m ooo

Group 1.

H-l

Li-7

Na-23

K-39. 1

Cu 63. 6

T)U OC /(

Ag-107. 9

PQ T 00 0

Au 197.2

Group 2.

Gl=9. 1

Mg 24. 3

Ca-40. 1

Zn 65.4

Q_ OT C

Cd-112.4

Ba-137. 3

TT__ OAA C

Ra 226

Group 3.

B-10.9

Al-27

Sc-44. 1

Ga-70

Vt R8 0

In-115

La- 139

Tl-204

Group 4.

C 12

Si 28. 3

Ti-48. 1

Ge-72. 5

f7_. (\~l o

Sn-118.7

Ce 140. 25

Ph 907 9

TVi 9Q9 9

G

N 

V-5

Cb-

Ta 

In this table the atomic weights are rounded off from the m
38 DATA OF GEOCHEMISTRY.

In each vertical column the elements are closely allied, forming 

the natural groups to which reference has already been made. The 

alkaline metals; the series calcium, strontium, and barium; the carbon group, and the halogens are examples of this regularity. In 

other words, similar elements appear at regular intervals and occupy 

similar places. If we follow any horizontal line of the table from 

left to right, a progressive change of valency is shown, and in both 

directions a systematic variation of properties is manifested. Broadly 

stated, the properties of the elements, chemical and physical, arc 

periodic functions of their atomic weights, and this is the most general expression of the periodic law. At certain points in the table 

gaps are left, and these are believed to correspond to unknown elements. For three of the spaces which were vacant when Mendeleef 

announced the law, he ventured to make specific predictions, and his 

prophecies have been verified. The elements scandium, gallium, and 

germanium were described by him in advance of their actual discovery, and in every essential particular his predictions were correct. 

Atomic weights, densities, melting points, and the character of the 

compounds which the metals should form were foretold, and in each 

case with a remarkable approximation to accuracy. This power of 

prevision is characteristic of all valid generalizations, and its exhibition in the periodic system led to the speedy adoption of the latter. 

Even radium and its emanation, niton, fall into their proper places 

in line with their near relatives, barium and argon.

An elaborate discussion of the periodic law would be out of place 

in a memoir of this kind, and its details must be sought elsewhere. 1 

Only its application to geochemistry can be considered now. In the 

first place, on looking at the table vertically it is noticeable that 

members of the same elementary group are commonly associated in 

nature. That is, similar elements have similar properties, form 

similar compounds, and give similar reactions, and because of the 

conditions last mentioned they are usually deposited together. Thus 

the platinum metals are seldom found apart from one another; the 

rare earths are invariably associated; chlorine, bromine, and iodine 

occur under closely analogous circumstances; selenium is obtained 

from native sulphur; cadmium is extracted from ores of zinc, and 

so on through a long list of regularities. The group relations govern 

many of the associations which we actually observe, although they 

are modified by the conditions which influence chemical union. Even 

here, however, regularities are still apparent. In combination unlike 

elements seek one another, and yet there appears to be a preference

1 See especially F. P. Venable, Development of the periodic law, Easton, Pennsylvania, 1890. The larger 

manuals of chemistry all discuss the law somewhat fully. T. Carnelley (Ber. Dcutsch. chcm. Gcscll., 

vol. 17,1884, p. 2287) has especially studied the bearings of the periodic law on the occurrence of the elements 

in nature.
THE CHEMICAL ELEMENTS. 39

for neighbors rather than for substances that are more remote. For 

example, silicon follows aluminum in the order of atomic weights, 

and silicates of aluminum are by far the most abundant minerals. 

The next element in order is phosphorus, and aluminum phosphates 

are more common and more numerous than the precisely similar arsenates. On the other hand, copper, whose atomic weight is nearer 

that of arsenic, oftener forms arsenates, although its phosphates are 

also known. An even more striking example is furnished by the 

compounds of the elementary series oxygen, sulphur, selenium, and 

tellurium. Oxides and oxidized salts of many elements are found in 

the mineral kingdom, and most commonly of metals having low 

atomic weights. From manganese and iron upward, sulphides are 

abundant; but selenium and tellurium are more often united with 

the heavier metals silver, mercury, lead, or bismuth, and tellurium 

with gold. The elements of high atomic weight appear to seek one 

another, a tendency which is indicated in many directions, even 

though it can not be stated in the form of a precise law. The general 

rule is evident, but its significance is not so clear.

We have already seen that the most abundant elements are among 

those of relatively low atomic weight, and this observation may be 

verified still further. In general, with some exceptions, the abundance of an element within a group depends on its atomic weight, 

but not in a distinctly regular manner. For instance, in the alkaline 

series, lithium is widely diffused in small quantities, sodium and potassium are very abundant, rubidium is scarce, and csesium is the rarest 

of all. The same rule holds in the tetrad group carbon, silicon, 

titanium, zirconium, and thorium; and in the halogens fluorine, 

chlorine, bromine, and iodine. In each of these series the abundance 

increases from the first to the second member and then diminishes 

to the end. In the oxygen group, however, the first member is much 

the most abundant and after that a steady decrease to tellurium is 

shown. An exception to the rule is found in the metals of the alkaline earths, for strontium is less abundant than barium, at least so far 

as our evidence now goes. Other exceptions also seem to exist, but 

they are possibly apparent and not real. In the light of better data 

than we now possess the anomalies may disappear. Here again we 

are dealing with an evident tendency of which the meaning is yet 

to be discovered. That the abundance and associations of the elements are connected with their position in the periodic system seems, 

however, to be clear. The coincidences are many, the exceptions arc 

comparatively few. 1

So much for the chemical side of the question. On the geological 

side other considerations must bo taken into account, and it is easily

i In an interesting memoir W. D. Ilarkins (Jour. Am. Chcrn. Roc., vol. M, p. 857,1917) has discussed tho 

relations of the elements to the periodic law as to their abundance and their evolution.
40 DATA OF GEOCHEMISTRY.

seen that the periodic law covers only a part of the elementary associations. Rocks are formed from magmas in which many and complex reactions are possible, and the simpler rules governing single 

minerals are no longer directly applicable. Some regularities, however, can be recognized, and certain elements are in a sense characteristic of certain kinds of rock. In the summary already given some of 

these regularities are indicated. They have been generalized by 

J. H. L. Vogt* somewhat as follows: In the highly siliceous rocks 

we find the largest proportions of the alkalies, of the rare earths, and 

of the elements glucinum, tungsten, molybdenum, uranium, columbium, tantalum, tin, zirconium, thorium, boron, and fluorine. The 

rocks low in silica are richer in the alkaline earths, and in magnesium, iron, manganese, chromium, nickel, cobalt, vanadium, titanium, 

phosphorus, sulphur, chlorine, and the platinum metals. To some 

extent, of course, these groups overlap, for between the two rock 

classes no definite line can be drawn. But the minerals of the rare 

earths, with the columbo-tantalates, tinstone, beryl, etc., seldom if 

ever occur except in rocks which approach the granites in general 

composition; whereas chromium, nickel, and the platinum metals are 

most commonly associated with peridotites or serpentines. For these 

differences in distribution no complete explanation is at hand; but 

they are probably due to differences of solubility. If we conceive of 

a mediosilicic magma in process of differentiation into a salic and a 

femic portion, the minor constituents will evidently tend to concentrate, each in the magmatic fraction in which it is most soluble. 

Solubilities of this order are yet to be experimentally studied.

' METEORITES.

The supposed analogy between the earth as a whole and an enormous meteorite has already been mentioned. A brief statement of 

the chemical nature of meteorites is therefore not out of place here. 

All known meteorites may be divided into three classes iron meteorites, stony meteorites, and carbonaceous meteorites. The last class, 

so far as direct observation goes, is very small, and need not be considered further. It is possible that carbonaceous meteorites may be 

numerous but commonly consumed before reaching the surface of the 

earth, a supposition, however, which can only be entertained as a 

speculation. The two principal classes of meteorites merge into one 

another, so that we have irons, stones, and all sorts of intermediate 

mixtures. The irons consist mainly of iron and nickel, with variable 

and minor admixtures of graphite, schreibersite, troilite, etc. The

1 Zeitschr. prakt. Geologie, 1898, p. 324. H. S. Washington (Trans. Am. Inst. Min. Eng., vol. 39, 1909, 

p. 735) has made a rather elaborate study of the distribution of the commoner elements with reference to 

the different magmas. In Proc. Nat. Acad. Sci., vol. 1, 1915, p. 574, he points out a correlation between 

K and Mg and between Na and Fe in igneous rocks.
THE CHEMICAL ELEMENTS. 41

terrestrial nickel-iron of Ovif ak in Greenland resembles meteoric iron 

in every essential particular. It is, therefore, often mentioned, as 

possibly typical of the material which forms the centrosphere.

The stony meteorites almost if not quite invariably contain disseminated particles of nickel-iron, but otherwise are analogous to 

rocks found on the surface of the earth. They are, however, not like 

the predominant rocks of the lithosphere. Their average composition has been calculated by G. P. Merrill 1 from 99 published analyses 

of stony meteorites, with the subjoined results. The first column of 

figures gives the actual average; the second is recalculated to 100 per 

cent after rejecting the admixed nickel-iron, sulphides, and phosphides.

Average composition of stony meteorites.

SiO,.. ...................................................

A1203 . ...................................................

Fe......................................................

FeO. ...................................................

CaO. ....................................................

MgO.. ...................................................

Na-sO.... ................................................

K20. ...................................................

MnO.. ...................................................

Chromite. ................................................

Ni, Co. .................................................

S.......................................................

P.......................................................

Found.

38.98

2.75

11.61

1C. 54

1.77

23.03

.95

.33

.56

.84

1.32

1.85

.11

100. 64

Recalculated.

45. 46

3.21

19.29

2.06

26.86

1.11

.38

.65

.98

100. 00

From this computation it appears that the stony meteorites have 

essentially the composition of a peridotite and are quite unlike the 

rocks which make up the great mass of the lithosphere. If, therefore, 

the earth was formed by an aggregation of meteors, as some writers 

have supposed, their average character was probably not that of 

the meteorites known to-day. Quartz and feldspars are the most 

abundant minerals of the lithosphere as we know it, but are almost 

wanting in the meteorites. A nucleus of iron with a stony crust 

could hardly be formed by any clashing together of innumerable 

meteoritic bodies; if the earth is analogous to them it can only be as an 

independent, individual meteorite of quite dissimilar composition. 2

1 Am. Jour. Sci. ; 4th ser., vol. 27, 1909, p. 469. See also W. A. Wahl, Zeitschr. anorg. Chemie, vol. CU, 

1910, p. 52, and 0. C. Farrington, Field Columbian Museum Publication 151,1911.

1 For a critical discussion of hypotheses relative to the nature and temperature of the centrosphere see 

H. Tliiene, Temperatur und Zustand des Erdinnern, Jena, 1907. Thiene gives many references to literature. See also E. H. L. Schwarz, South African Jour. Sci., April, 1910. Schwarz advocates a solid nucleus 

of the earth and assigns to it a low temperature.
CHAPTER II.

COMPOSITION OF THE ATMOSPHERE.

The outer gaseous envelope of our globe the atmosphere is 

commonly regarded as rather simple in its constitution, and indeed 

so it is, in comparison with the complexity of the ocean and the solid 

rocks beneath. Broadly considered, it consists of three chief constituents namely, oxygen, nitrogen, and argon commingled with 

various other substances in relatively small amounts, which may be 

classed, with some exceptions, as impurities. The three essential 

elements of air are mixed, but not combined; and they vary but 

little in their proportions. They constitute what may be called 

normal or average air. I am indebted to the late Sir William, Ramsay for the following percentage estimate of their relative quantities:

The principal constituents of the atmosphere.

Oxygen. ....................................................

Nitrogen. ..................................................

Argon. . .............. ^ .....................................

By weight.

23. 024

75. 539

1.437

100. 000

By volume.

20. 941

78. 122

.937

100. 000

With the argon occur certain rare gases whose proportions Ramsay 

estimates as follows: 1

Per cent by volume. 

Krypton..................................................... 0. 028

Xenon....................................................... . 005

Helium.....................'................................ . 0004

Neon.......:............................................... . 00123

These gases, with argon, are absolutely inert; and as they seem to 

have little geological significance they demand no further consideration here. Helium, as the end product of radioactive changes, will 

demand some attention later.

In addition to the elements enumerated above, ordinary air contains, in varying quantities, aqueous vapor, hydrogen dioxide, ozone,

1 Proc. Eoy. Soc., vol. 80A, 1908, p. 599. See also papers by G. Claude, Compt. Rend., vol. 148,1909, 

p. 1454, and H. E. Watson, Jour. Chem. Soc., vol. 97,1910, p. 810. A. Wegener (Zeitschr. anorg. Chemio, 

vol. 75,1912, p. 107) gives an estimate of the composition of the atmosphere, including its minor constituents.

42
THE ATMOSPHERE. 43

carbon diosLae, ammonia and other compounds of nitrogen, sometimes sulphur, traces of hydrogen, organic matter, and suspended 

solids; and among these substances some of the most active agents 

in producing geological changes are found. It will be advantageous 

to consider them separately and somewhat in detail; and in so doing 

we shall see that they all form part of a great system of circulation 

in which the atmosphere is adding matter to the solid globe and 

receiving matter from it in return. Between these gains and losses 

no balance can be struck, and yet certain tendencies appear to be 

distinctly manifested.

In a roughly approximate way it is often said that air consists of 

four-fifths nitrogen and one-fifth oxygen, and this is nearly true. 

The proportions of the two gases are almost constant but not absolutely so; for the innumerable analyses of air reveal variations larger 

than can be ascribed to experimental errors. A few of the better 

determinations are given in the subjoined table, stated in percentages 

by volume of oxygen. They refer, of course, to air dried and freed 

from all extraneous substances.

Determinations of oxygen in air, in percentage by volume.

Analyst.

R. Angus Smith «...

Do..............

U. Kreusler 6........

W. Eempel c.......

Do. ............

Do.............

A. Muntz and E.

Aubin.e 

E. W. Morley /..... 

F. G. Benedict g....

Locality of samples.

Paris...............

Manchester ........

Mountains of Scotland . 

Near Bonn... ......

Dresden ............

Para. ..............

Cape Horn. ........

Cleveland, Ohio. . . .

Number 

of 

analyses.

100

28

32

34

45

46

41

28

20

45 

212

Minimum.

20. 913

20. 840

20.78

20.80

20. 901

20. 877

20.86

20.72

 20. 90

Jlanimum.

20. 999

20. 970

21.02

21.18

20. 939

20. 971

21.00

20.97

20.95

Moan.

20. 960

90 Q94

20. 943

20. 970

20. 922

20. 930

20.92

20.89

20. 864

20. 933 

20. 952

o Seo R. Angus Smith's excellent book Air and rain, London, 1872. This work contains hundreds of 

other analyses.

b Ber. Doutsch. chem. Gesell., vol. 20,18S7, p. 991.

c Idem, vol. 18.1885, p. 1800.

<i Idem, vol. 20,1887, p. 1SC4.

e Cnmpt. Rend., vol. 102,1885, p. 422.

/ Cited by Hempel in Ber. Deutsch. chom. Gesell., vol. 20,1887, p. 1804.

g Carnegie Inst. Washington Publication No. 166, 1912. Benedict gives a very complete summary of 

earlier investigations.

Some of these variations are doubtless due to different methods 

of determination, but others can not be so interpreted. Hempel, 

comparing his analyses of air from Tromsoe, Norway, and Para, 

Brazil, infers that the atmosphere is slightly richer in oxygen near 

the poles than at the equator, an inference that would seem to need 

additional data before it can be regarded as established. The most
44 DATA OF GEOCHEMISTRY. '

significant variation of all, however, has been pointed out by E. W. 

Morley.1 As oxygen is heavier than nitrogen, it has been supposed 

that the upper regions of the atmosphere should show a small deficiency in oxygen, as compared with air from lower levels; although 

analyses of samples collected on mountain tops and from balloons 

have not borne out this suspicion. It is also supposed that severe 

depressions of temperature, the so-called "cold waves/' are connected with descents of air from very great elevations. Morley's 

analyses, conducted daily from January, 1880, to April, 1881, at 

Hudson, Ohio, sustain this belief. Every cold wave was attended by 

a deficiency of oxygen, the determinations, by volume, ranging from 

20.867 to 21.006 per cent, a difference far greater than could be 

attributed to errors of measurement. Air taken at the surface of 

the earth seems to show a very small concentration of the denser 

gas, oxygen.

By electrical discharges in the atmosphere some oxygen is probably 

converted into its allotropic modification, ozone, although this point 

has been questioned. Hydrogen dioxide is formed in the same way, 

and also oxides of nitrogen, and between these substances, in minute 

traces, it is not easy to discriminate. They all act upon the usual 

reagent, iodized starch paper, and therefore the identification of 

ozone remains somewhat uncertain, at least so far as ordinary chemical tests have gone. It is known, however, that the ultra-violet rays 

in the solar radiations so act upon cold dry oxygen as to convert 

part of it into ozone. This apparently takes place in the upper, 

drier, and rarefied strata of the atmosphere, as shown by absorption 

bands in the solar spectrum.2 Both ozone and hydrogen dioxide are 

powerful oxidizing agents, and either or both of them play some part 

in transforming organic matter suspended in the air into carbon 

dioxide, water, and probably ammonium nitrate; but the magnitude 

of the changes thus brought about can not be estimated with any 

degree of definiteness. .Ozone is also a powerful absorbent of solar 

radiations, and may possibly exert some influence in modifying 

terrestrial climates. Its generation by auroral discharges as well as 

by ultra-violet rays is considered in this connection by Humphreys. 

According to H. N. Holmes 3 the proportion of ozone in the atmosphere is greater in winter than in summer.

1 Am. Jour. Sci., 3d ser., vol. 18,1879, p. 168; vol. 22,1881, p. 417. For the distribution of the different 

gasesin the atmosphere according to elevation, see W. J. Humphreys, Bull. Mount Weather Observatory, 

vol. 2,1900, p. 68. On variations in the density of air at Geneva, see Guyc, Kovacs, and V/ourtzel, Jour, 

chim. phys., vol. 10,1912, p. 332.

3 See W. J. Humphreys, Astrophys. Jour., vol. 32,1910, p. 97, and authorities cited by him. Also Henriet 

and Bonyssy, Compt. Rend., vol. 147, 1908, p. 977. According to W. Hayhurst and J. N. Pring (Jour. 

Chem. Soc., vol. 97,1910, p. 868), the ozone in the atmosphere amounts to less than one partinfour thousand 

millions. In another paper (Proc. Roy. Soc., vol. 90A, p. 204) Pring finds that air from high altitudes 

contains more ozone than air from low levels.

3 Am. Chem. Jour., vol. 47, p. 497,1912.
THE ATMOSPHEEE. 45

Wherever animals breathe or fire burns oxygen is being withdrawn 

from the air and locked up in compounds. By growing plants under 

the influence of sunlight, one of these compounds, carbon dioxide, is 

decomposed and oxygen is liberated; but the losses exceed the gains. 

So also, when the weathering of a rock involves the change of ferrous into ferric compounds oxygen is absorbed, and only a portion of 

it is ever again released. The atmosphere then is slowly being 

depleted of its oxygen, but so slowly that no chemical test is ever 

likely to detect the change.

The nitrogen of the atmosphere varies reciprocally with the oxygen, the one gaining relatively as the other loses. But here again 

special variations need to be considered. By electrical discharges, 

as we have already seen, oxides of nitrogen are produced, yielding 

with the moisture of the air nitric and nitrous acids. Through the 

agency of microbes certain plants withdraw nitrogen directly from 

the air and thus remove it temporarily from atmospheric circulation. 

By the decay or combustion of organic matter some of this nitrogen 

is returned, partly in the free state and partly in gaseous combinations. The significance of these changes will be more clearly seen 

when we consider the subject of rain. It is enough to note here that 

all the nitrogen of organic matter came originally from the atmosphere, and that at the same time a .larger quantity of oxygen was 

also removed. The relative proportions of the two gases are evidently 

undergoing continuous modification.

According to Armand Gautier 1 free hydrogen is present in the 

atmosphere, together with other combustible gases. Air collected 

at the Roches-Douvres lighthouse, off the coast of Brittany, yielded 

1.21 milligrams of hydrogen in 100 liters. Air from the streets of 

Paris was found to contain the following substances, in cubic centimeters per 100 liters:

Free hydrogen............................................... 19.4

Methane....................................................... 12.1 '

Benzene and its homologues................................... 1.7

Carbonic oxide, with traces of defines and acetylenes............ .2

In short, air, according to Gautier, contains by volume about 1 part 

in 5,000 of free hydrogen, although Rayleigh's experiments 2 on the 

same subject would indicate that this estimate is at least six times 

too large. It is known, however, that hydrogen is emitted by volcanoes in considerable quantities, and Gautier has extracted the gas 

from granite and other rocks. One hundred grams of granite gave

1 Annales chim. phys., 7th ser., vol. 22,1901, p. 5.

2 Philos. Mag., 6th ser,, vol. 3,1902, p. 416. See also a criticism by A. Leduc, Compt. Rend., vol. 135,1902, 

p.830; aai replies to Raylaigh and Laiuc by Gautior, idem, vol. 135, p. 1025; vol. 136, p. 21. Also a paper 

by G. D. Liveing and J. Dewar, Proc. Roy. Soc., vol. 67,1900, p. 468. -G. Claude (Compt. Rend., vol. 148, 

1909, p. 1454) found less than one part per million of hydrogen in air.
46 DATA OF GEOCHEMISTRY.

him 134.61 cubic centimeters of hydrogen with other gases, and from 

this fact important inferences can be drawn. At the proper point, 

farther on, this subject will be discussed more fully. As for the 

hydrocarbons, their chief source is doubtless to be found in the 

decomposition of organic matter, methane or marsh gas in particular 

being clearly recognized among the exhalations from swamps. 

According to H. Henriet, 1 formaldehyde exists in the atmosphere in 

quantities ranging from 2 to 6 grams in 100 cubic meters. Bodies 

of this class are impurities in the atmosphere, and should not be 

reckoned among its normal constituents.

Sulphur compounds, which are also contaminations of the atmosphere, occur in air in variable quantities. Hydrogen sulphide is 

a product of putrefaction, but it is also given off by volcanoes, 

together with sulphur dioxide. The latter substance is also produced by the combustion of coal, and is therefore abundant in the 

air of manufacturing districts. At Lille, for example, A. Ladureau 2 

found 1.8 cubic centimeters of S02 in a cubic meter of air. It undergoes rapid oxidation in presence of moisture, being converted into 

sulphuric acid, and that compound, either free or represented by 

ammonium sulphate, is brought back to the surface of the earth by 

rain. In experiments running over five years at Rothamsted, 

England, R. Warington 3 found that the equivalent of 17.26 pounds 

of S03 was annually poured upon each acre of land at that station. 

Quantities of this order can not be ignored in any study of chemical 

erosion.

One of the most constant and most important of the accessory 

constituents of air is carbon dioxide. It is normally present to the 

extent of about 3 volumes in 10,000, with moderate variations above 

and below that figure. In towns its proportion is higher; in the open 

country it is slightly lower; but the agitation of winds and atmospheric currents prevent its excessive accumulation at any point. 

Only a few illustrations of its quantity need be given here,4 abnormal 

extremes being avoided.

iCompt. Tlcnd., vol. 138,1904, pp. 203, 1272.

2 Annales chim. phys., 5th ser., vol. 29,18S3, p. 427.

»Jour. Chem. Soo., vol. 51, 1887, p. 500. A later figure gives 17.41 pounds. See N. H. J. Miller, Jour. 

Agr. Sci., yol. 1,1905, p. 292. Miller cites data from Catania, Sicily, giving 20.89 pounds. G. Gray (Ropt. 

Australasian Assoc. Adv. Sci., vol. 1, 1888, p. 138) found 15.2 pounds per acre per annum in 4} years' observations at Lincoln, New Zealand.

* Very elaborate data are given in R. Angus Smith's Air and rain, to which reference has already been 

made. Seo also the excellent paper by E. A. Letts and R. F. Blake, Sci. Proc. Roy. Dublin Soc., vol. 9, 

pt. 2,1933, pp. 107-270. The latter memoir contains a summary of all the determinations previously made, 

with a very thorough bibliography of the subject.
THE ATMOSPHERE. 

Determinations of carbon dioxide in air.

47

Analyst.

J. Reiset a . ...................

Do.......................

T. 0. Van Niivs and B. F.

Adams. 6 

A. Petermann and J. Graftiau c . 

E. A. Letts and R. F. Blake <*. .

Locality.

Paris...... ...........

"M^flr "Dipirnp

Bloomington, Ind. . . . .

Gembloux, Belgium. . 

Belfast. .............

Number of determinations.

92

18

525 

46

COa (volumes 

perlO,OOQofair).

3.027

2.942

2.81G

2.94 

2.91

a Compt. Rend., vol. 88,1879, p. 1007. 

6 Am. Chem. Jour., vol. 9,1887, p. 64.

c Cited by Letts and Blake.

d Sci. Proc. Roy. Dublin Soc., vol. 9, pt. 2,1900, pp. 107-270.

At 3 parts in 10,000 the carbon dioxide in the atmosphere amounts 

to about 2,200,000,000,000 tons, equivalent to 600,000,000,000 tons 

of carbon.1

Thousands of other determinations having meteorological, sanitary, 

or -agricultural problems in view are recorded, but their discussion 

does not fall within the scope of this work.2 That in general terms 

the proportion of carbon dioxide in the atmosphere is very nearly 

uniform is the point that concerns us now. How is this apparent 

constancy maintained ?

From several sources carbon dioxide is being added to the air. 

The combustion of fuels, the respiration of animals, and the decay of 

organic matter all generate this gas. From mineral springs and volcanoes it is evolved in enormous quantities. According to J. B. 

Boussingault,3 Cotopaxi alone emits more carbon dioxide annually 

than is generated by life and combustion in a city like Paris, which in 

1844 threw into the air daily almost 3,000,000 cubic meters of the gas. 

Since that time the population of Paris has more than doubled, and 

the estimate must be correspondingly increased. The annual consumption of coal, estimated by A. Krogh * at 700,000,000 tons in 

1902, adds yearly to the atmosphere about one-thousandth of its 

present content in carbon dioxide. In a thousand years, then, if the 

rate were constant and no disturbing factors interfered, the amount 

of C02 in the atmosphere would be doubled. If we take into account 

the combustion of fuels other than coal and the large additions to the 

atmosphere from the sources previously mentioned, the result becomes

1 A. Krogh (Meddelelscr om Greenland, vol. 26,1904, p. 419) estimates the total C0» in the atmosphere 

at 2.4X1013 tons. Van Hise (Mon. U. S. Geol. Survey, vol. 47, 1904, p. 964) and Dittmar (Challenger 

Report, vol. 1, pt. 2, p. 954) give figures of the same order. Chamberlin (Jour. Geology, vol. 7, 1899, p. 082), 

makes a somewhat higher estimate.

2 For example, E. L. Moss (Proc. Roy. Dublin Soc., 2d ser., vol. 2,1878, p. 34) found that Arctic air is 

richer iu carbon dioxide than the air of England. In air from Greenland A. Krogh (Meddclelser om Greenland, vol. 26,1904, p. 409) found tho proportion of carbon dioxide to vary from 2.5 up to 7 parts in 10,000. 

The proportion determined by II. Legendre (Compt. Rend., vol. 143, 1906, p. 526) in ocean air was 3.35 

in 10,000.

3 Anna'cs clu'in. phys., 3d ser., vol. 10,1844, p. 456.

4 Loc. cit. The present consumption of coal exceeds 1,000,000,000 tons, lurogh's figures should be corre^ 

spondingly modified.
48 DATA OF GEOCHEMISTRY.

still more startling. Were there no counterbalancing of this increase 

in atmospheric carbon, animal life would soon become impossible 

upon our planet. Figures like those given above convey some faint 

notion of the magnitude of the chemical processes now under consideration. Perhaps the majority of shooting stars represent the 

combustion of carbonaceous meteorites in the upper regions of the 

atmosphere and the addition of carbon dioxide to the air. Few 

meteors of that class reach the surface of the earth.

On the other side of the account two large factors are to be considered first, the decomposition of carbon dioxide by plants, with 

liberation of oxygen; and, second, the consumption of carbon dioxide 

in the weathering of rocks. To neither of these factors can any 

precise valuation be given, although various writers have attempted 

to estimate their magnitude. E. H. Cook,1 for instance, from very 

uncertain data, computes that leaf action alone more than compensates for the production of carbon dioxide, and that without such 

compensation the quantity present in the air would double in about 

100 years. Some of the carbon dioxide thus absorbed is annually 

returned to the atmosphere by the autumnal decay of leaves, but 

part of it is permanently withdrawn.

T. Sterry Hunt 2 illustrates the effect of weathering by the statement that the production from orthoclase of a layer of kaolin, 500 

meters thick and completely enveloping the globe, would consume 

21 times the amount of carbon dioxide now present in the atmosphere. He also computes that a similar shell of pure carbon, of 

density 1.25 and 0.7 meter in thickness, would require for its combustion all the oxygen of the air. Such estimates may have slight 

numerical value, but they serve to show how vast and how important the processes under consideration really are. The carbon 

of the coal measures and of the sedimentary rocks has all been 

drawn, directly or indirectly, from the atmosphere. Soluble carbonates, produced by weathering, are washed into the ocean, and are 

there transformed into sediments, into shells, or into coral reefs; 

but the atmosphere was the source from which all, or nearly all, of 

the carbon thus stored away was taken. The carbon of the sedimentary rocks, as computed with the aid of data given in the preceding chapter, is about 30,000 times as much as is now contained 

in the atmosphere. T. C. Chamberlin 3 estimates that the amount 

of carbon dioxide annually withdrawn from the atmosphere is 

1,620,000,000 tons, but the method by which this figure was obtained 

is not clearly stated. In calculations of this sort there is a certain 

fascination, but their chief merit seems to lie in their suggestiveness.

1 Philos. Mag., 5th ser., vol. 14,1882, p. 387.

2 Arn. Jour. Sci., 3d ser., vol. 19,1880, p. 349. 

8 Jour. Geology, vol. 7,1899, p. 682.
THE ATMOSPHERE. 49 

THE RELATIONS OF CARBON DIOXIDE TO CLIMATE.

From a geological standpoint the carbon dioxide of the air has a 

twofold significance first,- as a weathering agent, and second, as a 

regulator of climate. The subject of weathering will receive due 

consideration later; but the climatic value of atmospheric carbon 

may properly be mentioned now. Both carbon dioxide and aqueous 

vapor serve as selective absorbents for the solar rays, and, by blanketing the earth, they help to avert excessive changes of temperature. 

On the physical side, and as regards carbon dioxide, this question 

has .been discussed by S. Arrhenius, 1 who argues that if the quantity 

of the gas in the atmosphere were increased about threefold, the 

mean temperature of the Arctic regions would rise 8° or 9°. A 

corresponding loss of carbon dioxide would lead to a lowering of 

temperature; and in variations of this kind we may find an explanation of the alterations of climate which have undoubtedly occurred. 

The glacial period, for example, may have been due to a loss of carbon 

dioxide from the atmosphere. To account for such gains and losses, 

Arrhenius cites with great fullness the work of A. G. Hogbom, 

who regards volcanoes as the chief source of supply. Just as individual volcanoes vary in activity from quietude to violence, so 

the volcanic activity of the globe has varied from time to time. 

During periods of great energy the carbon dioxide of the air would 

be abundant; at other times its quantity would be smaller. Hogbom 

estimates that the total carbon of the atmosphere would form a 

layer 1 millimeter thick, enveloping the entire globe. The quantity 

of carbon in living matter he regards as being of the same order, 

neither many fold greater nor many fold less. The combustion of 

coal he reckons as about balancing the losses of the atmosphere 

by weathering; and in this way he reaches his conclusion that volcanic action is the important factor of the problem.

This theory of Arrhenius has been, however, a subject of much 

controversy. It was strongly endorsed by F. Frech,2 who has 

attempted by means of it to account for glacial periods. E. Kayser,3 

on the other hand, has attempted to prove that the views of Arrhenius 

are untenable, on the ground of K. J. Angstrom's * physical researches. 

Angstrom has shown that carbon dioxide in the atmosphere can 

not possibly absorb more than 16 per cent of the terrestrial radiations, 

and that variations in its amount are of very small effect. Further1 Philos. Mag., 5th ser., vol. 41,1896, p. 237. Annalen d. Physik, 4th ser., vol. 4,1901, p. 690.

2 Zeitschr. Gesell. Erdkunde, Berlin, vol. 37, 1902, pp. 611, 671; idem, 1906, p. 533. Neues Jahrb., 1903, 

pt. 2, p.74.

8 Centralbl. Min., Geol. u. Pal., 1903, p. 553; 1909, p. 660. Kejoinder by Arrhenius, idem, 1909, p. 481, 

Later papers by Arrhenius and Kayser are in the same journal for 1913, pp. 582, 764.

4 Annalen d. Physik, 4th ser., vol. 3, 1900, p. 720; vol. 6, 1901, p. 163. Angstrom himself criticizes Arr- 

. henius.

113750° 19 Bull. 695 4
50 DATA OF GEOCHEMISTRY.

more, C. G. Abbot and F. E. Fowle 1 have shown that aqueous 

vapor is present in the atmosphere in quantities so large as to make 

the climatic significance of carbon dioxide negligible. The principal 

absorbent of terrestrial radiations is the vapor of water. Whether 

the theory of Arrhenius is in harmony with the facts of historical 

geology that is, whether periods of volcanic activity have coincided 

with warmer climates, and a slackening of activity with lowering of 

temperature is also in dispute. The controversy is not yet ended.2 

One other suggested regulative agency remains to be mentioned. 

The ocean is a vast reservoir of carbon dioxide, which is partly in 

solution and partly combined. Between the surface of the sea and 

the atmosphere there is a continual interchange, each one sometimes 

losing and sometimes gaining gas. Upon this fact a theory of 

climatic variations has been founded, and in another chapter, upon 

the ocean, it will be stated and discussed.

RAINFALL.

Among all the constituents of the atmosphere aqueous yapor is the 

most variable in amount and the most important geologically. It is 

not merely a solvent and disintegrator of rocks, but it is also a carrier, 

distributing other substances and making them more active. To the 

circulation of atmospheric moisture we owe our rivers, and through 

them erosion is effected. The process of erosion is partly chemical 

and partly mechanical, and the two modes of action reinforce each 

other. By flowing streams the rocks are ground to sand, and so new 

surfaces are exposed to chemical attack. On the other hand, chemical 

solution weakens the rocks and renders them easier to remove mechanically. As water evaporates from the surface of the sea, it lifts, by 

inclusion in vapory vesicles, great quantities of saline matter, which 

are afterward deposited by rainfall upon the land. It is through 

the agency of rain or snow that the atmosphere produces its greatest 

geological effects; but the chemical side of its activity is all that concerns us now. Aqueous vapor dissolves and concentrates the other 

ingredients of air and brings them to the ground in rain.

In one sense oxygen is the most active of the atmospheric gases, but 

without the aid of moisture its effectiveness is small. Perfectly dry 

oxygen is comparatively.inert;-for example, phosphorus burns in it 

slowly and without flame, but the merest trace of water gives the gas 

its usual activity.3 More than this trace is always present in the air,

1 Annals Astrophys. Observ., vol. 2,1908, pp. 172,175.

2 On the geologic side of the question see Kayser, loc. cit., and Lehrbuch der allgemeiuen Geologic, 3d 

ed., 1909, pp. 81-83. Also E. Koken, Neues Jahrb., Test Band, 1907, p. 530, and E. Philippi, Centralbl. 

Min., Geol. u. Pal., 1908, p. 360. The papers referred to contain many other references to literature. On 

the influence of volcanic dust on climate, see "W. J. Humphreys, Jour. Washington Acad. Sci., vol. 3, p. 

365, 1913.

3 See H. Brereton Baker, Proc. Roy. Soc., vol. 45,1888, p. 1.
THE ATMOSPHERE. 51

and when it condenses to rain it dissolves oxygen, nitrogen, carbon 

dioxide, and other gases. These substances.differ in solubility, and 

therefore dissolved air contains them in abnormal proportions. In 

air extracted from rain water, Humboldt and Gay-Lussac found 31 

per cent of oxygen. R. W. Bunsen,1 who examined air from rain 

water at 'different temperatures, gives the following table to illustrate 

its composition by volume:

Composition of dissolved air at different temperatures.

N

0,.... ......................

G&.... ....................

0°

63.20

33.88

2.92

100. 00

5°

63.35

33.97

2.68

100. 00

10°

63.49

34.05

2.46

' 100. 00

15°

63.62

34.12

2.26

100. 00

20°

63. 69

34. 17

2.14

100.00

In air from sea water 0. Pettersson and K. Sond6n 2 found nearly 

34 per cent of oxygen. In dissolved air, then, and especially in ram, 

oxygen is concentrated, and in that way its'effectiveness is increased. 

The same is true of carbon dioxide. Rain brings it to the surface of 

the earth, where its eroding power comes into play.

As a carrier of ammonia, nitric acid, sulphuric acid, and chlorine 

rain water performs a function of the highest significance to agriculture, but whose geological importance has not been generally recognized. Rain and snow collect these imp'urities from the atmosphere, 

in quantities which vary with local conditions, and redistribute them 

upon the soil. Many analyses of Tain water have therefor® been 

made, not only at agricultural experiment stations but also for sani-" 

tary purposes, and a few of the results obtained are given below. 3 

Figures for sulphuric acid have already been cited. The values 

given are stated in pounds per acre per annum brought to the surface 

of the earth at the several stations named. For nitrogen compounds 

the data are as follows:

i Liebig's Annalen, vol. 93,1855, p. 43. See also M. Banmcrt, idem, vol. 88,1853, p. 17, for evidence of the 

same order.

- Ber. Deutsch. chcm. Gesell., vol. 22,1889, p. 1439.

3 For the older data sec R. Angus Smith, Air and rain, London, 1872. For nitrogen and chlorides in rain 

" and snow at Mount Vcrnon, Iowa, see G. H. Wiesner, Chem. News, vol. 109, 1914, p. 85. See also W. J. 

Kuox, for data from the same locality, Chem. News, vol. Ill, 1915, p. 61. F. T. Shutt (Trans. Roy. 

Soc. Canada, 3d ser., vol. 8,1914, p. 83) gives data for nitrogen in rain and snow during seven years' observations at 0 ttawa The observations cover 14 weeks only. The annual report of the Rothamstod Station, 

England, for 1913, contains additional data on nitrogen.
52 DATA OF GEOCHEMISTRY.

Nitrogen brought to the surface of the earth by rain. 

[Pounds per acre per annum.]

Rothamsted, England a . ........

Rothamsted, England &..........

Near Paris c. ..................

Caracas, Venezuela &. ..........

Gembloux, Belgium e. .........

Barbados /....................

British Guiana ff. ..............

Kansas &. ......................

Utah*........................

New Zealand '<-'. ................

Iceland &. .....................

Hebrides J .....................

Ammoniacal.

2.406

2.71

1.009

1.006

2.63

5.06

.802

.311

Nitrogen.

Nitric.

1.13

.516

2.443

1.886

1.06

. .356

.263

.289

Total.

3.84

8.93

9.20

3.452

3.541

3.69

5.42

3.636

2.08

1.065

.600

1888-1901.

11 years' average.

20 .years 'average.

3 years' average.

3 years 'aver age.

11 months' average. 

11 months' average.

a R. Warington, Jour. Chem. Soc., vol. 51,1887, p. 500.

6 N. H. J. Miller. Jour. Agr. Sci.. vol. 1,1905, p. 286. See also R. Warington, Jour. Chem. Soc., vol. 35, 

1889, p. 537, for earlier figures. Miller gives a taole for 35 localities, and also an excellent bibliography of 

the entire subject of nitrogen, sulphuric acid, and chlorine in rain.

c Albert Levy, Jour. Chem. Soc., vol. 56,18S9, p. 299. (Abstract.) 10.01 kilos per hectare.

d A. Muntz and V. Marcano, Compt. Rend., vol. 108,1889. p. 1002.

e A. Petermann and J. Graftiau, Jour. Chem. Soc., vol. 64,1893, abst. ii, p. 548. 10.31 kilos per hectare.

/ J. B. Harrison and J. Williams. Jour. Am. Chem. Soc., vol. 19, 1897, p. 1.

g J. B. Harrison, Rept. Dept. Sci. and Agr., British Guiana, 1909-10. For earlier figures see preceding 

reference.

ft G. H. Failyer and C. M. Brcese, Second Ann. Rept. Exper. Sta.. Kansas Agr. Coll., 1889.

* R. W. Erwin, Fourth Ann. Rept. Utah Agr. Coll. Exper. Sta., 1893.

j Hutchinson, Tenth Ann. Rept. Mississippi Agr. and Mech. Coll. Exper. Sta., 1897. See also Eighth 

Ann. Rept.

k G. Gray, Rept. Australasian Assoc. Adv. Sci., vol. 1,1888, p. 138. The figures include some albuminoid nitrogen.

i N. H. J. Miller, Jour. Chem. Soc., vol. 106, i, 1914, p. 128. Abstract.

In most cases ammonia is in excess over nitric acidj but in the 

Tropics the reverse seems to be true. The substance actually brought 

to earth, then, is in great part ammonium nitrate, but the conditions 

are modified when hydrochloric or sulphuric acid happens to be 

present in the air. A large part of the combined nitrogen has of 

course been added to the atmosphere by organic decomposition at the 

surface of the earth; but some of it is due, as we have already seen, 

to electrical discharges during thunderstorms. The geological significance of free acids in rain is obvious, for it means an increase in 

the eroding power of water.

Furthermore, in this circulation of nitrogen between the ground 

and the air, the ground gains more than it loses. All of the nitrogen 

thus fixed in combination is not released again to the atmosphere; 

only a part so returns.1

i T. Schloesing (Contributions al'6tude delachimieagricole, 1888, p. 55) estimates the average ammonia 

in the atmosphere at 0.02 milligram per cubic meter. This amounts to 1,600 grams over every hectare of 

the earth's surface.

On nitrates in the atmosphere see A. Muntz and E. Laind, Compt. Rend., vol. 152, 1911, p. 167. J. 

Hirschwald (Die Priifung der natiirlichen Bausteine, Berlin, 1908, p. 5) gives many data for ammonia 

and nitrates in the air.
THE ATMOSPHERE. 53

The figures for atmospheric chlorine are even more surprising; 

but they represent in general salt raised by vapor from the ocean. 

Where chemical industries are carried on, free hydrochloric acid may 

enter the air, and some hydrochloric acid is also evolved from volcanoes; but these are minor factors of little more than local significance. 

Chlorine is abundant in the air only near the sea, and its proportion 

rapidly diminishes as we recede from the coast. This is clearly shown 

by the ".chlorine map" of Massachusetts,1 and by several later 

documents of the same kind, in which the "normal chlorine" of the 

potable waters is indicated by isochlors that follow the contour of 

the shore. Near the ocean the waters are rich in chlorides, which 

diminish rapidly as we follow the streams inland.

The amount of salt precipitated by rain upon the land is by no 

means inconsiderable. For quantitative data a few examples must 

suffice, stated in the same way as for nitrogen.

Chlorides' brought to the surface of the earth by rain. 

[Pounds per acre per annum.]

Locality.

Cirencester, England «. .........

Rothamsted, England &........

Rothamsted, England c . .......

Perugia, Italy d. ...............

Cevlon e . ......................

Calcutta e. ....................

Madras «. .....................

Barbados 0... ..................

British Guiana A. ...............

New Zealand *..... .............

Chlorine.

14.40

14.87

180. 63

32.87

36.27

17. 00

116. 98

129. 24

61.20

Sodium 

chloride.

36. 10

24.00

37.95

195. 00

Remarks.

26 years' average.

In 1887.

5 years' average.

20 years' average.

4$ years' average.

o E. Kinch, Jour. Chem. Soc., vol. 77, 1900, p. 1271.

b R. Warington, idem, vol. 51,1887, p. 500.

c N. H. J. Miller, Jour. Agr. Sci., vol. 1,1905. p. 292. Miller gives figures for several other localities.

<i G. Bellucci, Jour. Chem. Soc., abstract, vol. 56,1899, p. 299. 42.531 kilos per hectare.

e Cited by Miller, loc. cit.

/ J. Pirovaroff, Ann. geol. min. Russie, vol. 9.1908, p. 274. 19 kilos per hectare.

g J. B. Harrison and J. Williams. Jour. Am, Chem. Soc.. vol. 19,1897, p. 1.

ft J. B. Harrison, Rept. Dept. Sci. and Agr., British Guiana, 1909-10. For earlier figures, see preceding

t G. Gray, Rept. Australian Assoc. Adv. Sci., vol. 1,1888, p. 138.

Furthermore, we have the older researches of Pierre,2 whose analyses were made in 1851 at Caen, in Normandy, where each hectare

1 See T. M. Drown, in Rept. Massachusetts State Board of Health, etc., vol. 1, December, 1889. Mrs. 

Ellen S. Richards, who was associated with Drown in this investigation, has since published, jointly with 

A. T. Hopkins, a similar map of Jamaica (Tech. Quart., vol. 11,1898, p. 227). For a chlorine map of Long 

Island, sec G. C. Whipple and D. D. Jackson, Tech. Quart., vol. 13, 1900, p. 145. One of Connecticut 

appears in the report of the State board of health for 1895. For a general chlorine map of New York and 

New England, see Jackson, Water-Supply Paper U. S. Geol. Survey No. 144,1905.

2 Seo R. Angus Smith, Air and rain, 1872, pp. 223-232. Pierre also cites valuable data obtained by Barral, 

Biricau, Liebig, Boussingault, and others. See also A. Bobierre, Compt. Rend., vol. 58,1864, p. 755, for 

the composition of rain water collected at Nantes in 1863. The average sodium chloride amounted to 14.09 

grams per cubic meter. On nitrogen compounds, chlorine and sulphur in rain and snow at Mount Vernon, 

Iowa, see B. Artis, Chem. News, vol. 113,1916, p. 3, and E. L. Peck, idem, vol. 116, 1917, p. 283.
54 DATA OF GEOCHEMISTRY.

of soil was found to receive annually in rain the following 

impurities :

NaCl.............

KC1...............

CaOL.. ............

Kilograms. 

................ 37.5

................ 8. 2

................ 2.5

................ 1.8

NaSO

K2S04 .. ...........

MeSO.............

Kilograms. 

............... 8. 4

............... 8. 0

............... 6.2

............... 5.9

These citations are enough to show the great geological importance of rainfall over and above its ordinary mechanical effects 

and its value as a solvent after it enters the ground.

The atmospheric circulation of salt has received much attention, 

and F. PoSepny^ 1 as long ago as 1877, attempted to show that the 

sodium chloride of inland waters was derived largely from this 

source. Of late years the same idea has been strongly urged by 

W. Ackroyd,2 who has gone so far as to attribute ,iihe salinity of the 

Dead Sea to chlorides brought by winds from the Mediterranean. 

Furthermore, A. Muntz 3 has pointed out that without this circulation of salt, and its replenishment of the land, the latter would soon 

be drained of its chlorides, and living beings would suffer from the 

loss. These writers probably overemphasize the importance of 

"cyclic salts," as they have been called, but their arguments are 

enough to show that the phenomena under consideration are by no 

means insignificant. Wind-borne salt plays a distinct part in the 

economy of nature; but its influence is yet to be studied in definite, 

quantitative terms. An exception to this statement is furnished by 

the Sambhar Salt -Lake in India, which will be considered in detail 

in another chapter.

Apart from its function in carrying soluble salts, the atmosphere 

performs a great work in mechanically transporting other solids. Its 

effectiveness as a carrier of dust is well understood; dust from the 

explosion of Krakatoa was borne twice around the globe, but such 

processes bear indirectly upon chemistry. In desert regions the sandstorms help to disintegrate the rocks, and so to render them more 

susceptible to chemical change. Dust, also, whether cosmic or terrestial, furnishes the nuclei around which drops of rain are formed, 

and so reinforces the activity of atmospheric moisture.4

1 Sitzungsb. K. Akad. Wiss. Wien, vol. 76, Abth. 1, 1877, p. 179. See also a discussion of this memoir by 

E. Tietze, Jahrb. IC-k. geol. Beichsanstalt, vol. 27, 1877, p. 341. In a recent discussion of this subject 

E. Dubois (Arch. MusSe Teyler, 2d ser., vol. 10, 1907, p. 441) has estimated the amount of atmospheric 

salt annually precipitated in rainfall on two provinces of Holland as about 6,000,000 kilograms.

2 Geol. Mag., 4th ser., vol. 8, 1900, p. 445. Proc. Yorkshire Geol. and Polytech. Soc., vol. 14, p. 408. 

Ohem'. News, Jan. 8, 1904. \

s Compt. Bend., vol. 112, 1891, p. 449.

4 See J. Aitken, Proc. Boy. Soc. Edinburgh, vol. 17, 1390, p. 193. An interesting lecture by A. Ditto 

(Bevue sclent., 5th ser., vol. 2, 1904, p. 709), on metals in the atmosphere is well worthy of notice. It deals 

with dust, meteoric matter, cyclic salts, ammonium compounds, etc. .
. THE ATMOSPHERE. 55 

THE PRIMITIVE ATMOSPHERE.

Although, the main purpose of this treatise is to assemble and 

classify data rather than to discuss speculations, a few words as to 

the origin of our atmosphere may not be out of place. Upon this 

subject much has been written, especially in recent years; but none 

of the widely variant theories so far advanced can be regarded as 

conclusive. The problem, indeed, is one of cosmology, and chemical 

data supply only a single line of attack. Physical, astronomical, 

mathematical, and geological evidence must be brought to bear upon 

the question before anything like an intelligent conclusion can be 

reached. Even then, with every precaution taken, we can hardly be 

sure that our fundamental premises are sound.

One phase of the discussion, to which I have already referred, 

relates to the constancy or variability of the atmosphere. The accumulations of carbon in the lithosphere, such as the coal measures, 

the limestones, and the like, have led some geologists to assume that 

the atmosphere at some former time was vastly richer in carbonic 

acid than it is now; but the fossil records of life suggest that the 

differences could not have been extreme. With a large excess of carbon dioxide, the existence of air-breathing animals would be impossible. Only anaerobic organisms could live. It is clear that the 

stored carbon of the sedimentary rocks was once largely in the atmosphere, but was it ever all present there at any one time ?

Such a supposition is improbable. The known carbon of the 

lithosphere, if converted into carbon dioxide, would yield nearly 25 

times the present mass of. the entire atmosphere, and the atmospheric 

pressure at the surface of the earth would be enormously increased.1 

It is more likely that carbon dioxide has been added to the atmosphere 

by volcanic agency, in some such manner as this: Primitive carbon, 

like the graphite found in meteorites, at temperatures no greater 

than that of molten lava, reduced the magnetite of igneous rocks to 

metallic iron, such as is found in many basalts, and was itself thereby 

oxidized. Then, discharged into the atmosphere as dioxide, it became 

subject to the familiar reactions which restored it to the lithosphere 

as coal or limestone.

In order to account for the observed phenomena, several essentially 

distinct hypotheses have been proposed T. Sterry Hunt,2 for 

example, argued in favor of a cosmical atmosphere, pervading all 

space, from which a steady supply of carbon dioxide has been drawn. 

This theory, which was also favored by Alexander Winchell,s postulates a universal, exhaustless reservoir of carbon, which should be

i For a curious speculation on the mass of the atmosphere, see R. H. McKee, Science, vol. 23,1908, p. 271. 

He argues that the present atmosphere is as great as the earth is capable of retaining. 

" Am. Jour. Sci., 3d scr., vol. 19,1880, p. 349. 

»Science, vol. 2,18S3, p. 820.
56 DATA OF GEOCHEMISTRY.

able to satisfy all demands. But what evidence have we that such 

an atmosphere exists ? . ' -

S. Meunier,1 criticizing Hunt, points out that some planets have 

excessive and others deficient atmospheres, and that a cosmic uniformity is therefore improbable. Meunier prefers the volcanic theory, . 

for which we have at least some basis of fact. We know that gases V 

are emitted from volcanoes, even though there is no certain measure 

of their quantity, and the question to be determined relates to the 

adequacy and the source of the supply. That question I shall not 

now attempt to answer; but, obviously, if the volcanic hypothesis 

be true, the cessation of volcanism would signify the end of life on 

the globe. It would be followed by the consumption of all available ( 

carbon dioxide, so that plant life, and consequently animal life, 

could no longer be supported. A cosmical atmosphere has no 

assignable limit; an atmosphere of volcanic origin must sooner or later 

be exhausted. May not the moon be an example of such an atmospheric death?2

Another theory relative to the atmosphere is based upon the belief v 

that the unoxidized, but oxidizable, substances in the primitive rooks ( 

are sufficient in quantity to absorb all the oxygen of the air. If our ! 

globe solidified from a molten condition, and if, as commonly supposed, oxidized compounds were the first to form, the observed conditions are not easy to explain. C. J. Koene, indeed, assumed that 

the primitive atmosphere contained no free oxygen, #nd he has been 

followed of late years by T. L. Phipson,3 J. Lemberg,4 John Stevenson, 5 and Lord Kelvin.6 Lemberg and Kelvin, however, do not go 

to extremes, but admit that possibly some free oxygen was present 

even in the earliest times. Lemberg argued that the primeval atmos- 

.phere contained chiefly hydrogen, nitrogen, volatile chlorides, and 

carbon compounds, the oxygen which is now free being then united 

with carbon and iron. The liberation of oxygen began with the 

appearance of low forms of plant life, possibly reached a maximum 

in Carboniferous time, and has since diminished. Stevenson's argument is much more elaborate, and starts with an estimate of the 

uncombined carbon now existent in the sedimentary formations. 

In the deposition of that carbon, oxygen was liberated, and from data 

of this kind it is argued that the atmospheric supply of oxygen is 

steadily increasing, while that of carbon dioxide diminishes. The

1 Compt. Rend., vol. 87,1878, p. 541.

2 It is probable that the combustion of carbonaceous meteorites in the atmosphere may add carbon 

dioxide to it, but the quantity so supplied can hardly be estimated. It is possibly large.

a Chem. News, vol. 67,1893, p. 135. Also several notes in vols. 68,69, and 70. For Koene's work see Phipson's papers, 1893-94.

< Zeitschr. Deutsch. geol. Gesell., vol. 40,1888, pp. 630-634.

6 Philos. Mag., 5th ser., vol. 50, 1900, pp. 312, 399; 6th ser., vol. 4, 1902, p. 435; vol. 9,1905, p. 88; vol. 11, 

1906, p. 226.

«Idem,. 5th ser., vol. 47,1899, pp. 85-89.
 THE ATMOSPHEEE. 57

. statement that no oxygen has been found in the gases extracted from 

rocks is also adduced in favor of the theory. First, an oxidized crust 

and no free oxygen in the air; then processes of reduction coming into 

play; and at last the appearance of lower forms of plants, which prepared the atmosphere to sustain animal life. The arguments are ingenious, but to my mind they exemplify the result of attaching excessive 

importance to one set of phenomena alone. It is not clear that due 

account has been taken of the checks and balances which are actually 

observed. At present the known losses of oxygen seem to exceed the 

gains. For example, C. H. Smyth1 has estimated that the oxygen 

withdrawn from the air by the change of ferrous to ferric compounds, 

and so locked up in the sedimentary rocks, is equal to 68.8 per cent 

of the quantity now present in the atmosphere.

But were oxidized compounds the first compounds to form? If 

they were, then the arguments just cited are valid, but the premises 

are doubtful. If the molten globe was as hot as has been supposed, 

it is likely that carbides, silicides, nitrides, etc., would be generated 

first, and in that case all the oxygen of the lithosphere would be 

atmospheric. This supposition is based upon the results obtained 

with the aid of the electric furnace at temperatures which decompose 

oxygen compounds in the presence of carbon, silicon, or nitrogen, 

substances of the class just named being then produced. Considerations of this kind have been elaborately developed by H. Lenicque,2 

who, however, pushes them to extremes. He even goes so far as to 

ascribe great masses of limestone to the atmospheric oxidation of 

primitive carbides. It will be observed at once that theories of this 

order are directly related to the hypotheses which postulate an inorganic origin for petroleum a subject which will be more fully discussed in the proper chapter. For the present it is enough to see 

that cogent arguments may lead us to either of two opposite beliefs 

that the primitive atmosphere was rich in oxygen, or that it was 

oxygen free.

The balance or lack of balance between carbon and oxygen is, after 

all, only one factor in the problem. The origin of the atmosphere 

as a whole is a much larger question, and our answers to it must 

depend upon our views as to the genesis of the solar system. If we 

accept the nebular hypothesis, we are likely to conclude that the 

atmosphere is merely a residuum of uncombined gases which were 

left behind when the globe assumed its solid form. That seems to be 

the prevalent opinion, although it must be modified by the observed 

facts of volcanism. The outer envelope of the earth receives reinforcements from within, whose sources will be considered at length 

in another chapter.

1 Jour. Geology, vol. 13,1905, p. 319. * M&n. Soc. ing&i. civils France, October, 1903, p. 346.
58 DATA OF GEOCHEMISTRY.

Quite a different theory of the earth's origin has lately been developed by T. C. Chamberlin, 1 who imagines a planet built up by 

slow aggregations of small, solid bodies. Each of these particles, 

or meteorites, carried with it entangled or occluded atmospheric 

material. In time the accumulation of originally cold matter developed pressure enough to raise the central portions of the mass to a 

high temperature, and gases were then expelled. Thus the atmosphere was generated from within the globe instead of remaining as a 

residuum around it. We know that meteorites contain occluded 

gases, and that gases are also extractable from igneous rocks, and 

these facts lend to the hypothesis a certain plausibility. The gases 

thus obtainable from the lithosphere are equivalent to many potential 

atmospheres, although, as we have already seen, oxygen is not among 

them. On Chamberlin's hypothesis the atmosphere has grown from 

small beginnings; the nebular conception assumes that it was largest 

at first. E. H. L. Schwarz, 2 who accepts Chamberlin's views,.concludes that the primitive atmosphere is actually represented to.-day 

by the gases extractable from meteorites. Hydrogen, nitrogen, 

methane, and both oxides of carbon are the gases in question, but 

there is no free oxygen.

One curious speculation, which may be connected with the theory 

just described, relates to the nature of the earth's interior. From 

the known fact that the temperature rises as we descend into the 

crust of the earth, calculations have been made to show that the 

temperature of the centrosphere must be enormously high. In fact, 

if the rate of increase is constant, the temperature must reach a 

degree far above the critical point of any known element. Matter 

in the interior of the earth, then, should be gaseous or quasi-gaseous. 

This suggestion was first offered by Herbert Spencer,3 later by A. 

Hitter,4 and has been more recently developed by S. Arrhenius.5 It 

has, however, only speculative value, for it rests upon assumptions 

which can not be tested experimentally, and which may never be 

verified. A discussion of the subject falls without the scope of this 

memoir, and only these brief references to it are admissible here.6

iJour. Geology, vol. 5,1897, p. 653; vol. 6,1898, pp. 459,609; vol. 7,1899, pp. 545, 667, 751. See also H. L. 

Fairchild, Am. Geologist, vol. 33,1904, p. 94.'

2 Causal geology, London, 1910, p. 93.

3 See his essays on the nebular hypothesis (1858) and the constitution of the sun (1865). Cited from New 

York edition of 1892.

4 Wied. Annalen, vol. 5,1878, p. 405.

s Geol. Foren. Forhandl., vol. 22,1900, p. 395.

G For a historical summary relative to the supposed gaseous interior of the earth see S. Gunther, Jahresb. 

Geog. Gesell. Miinchen, 1890-91, Heft 14, p. 1. See also the monograph by H. Thiene, Temperate und 

Zustand des Erdinnern, Jena, 1907.
CHAPTER III.

LAKES AND RIVERS. 1 

ORIGIN.

When rain falls upon the surface of the earth, bringing with it the 

impurities noted in the preceding chapter, part of it sinks deeply 

underground to reappear in springs. Another part runs off directly 

into streams, a part is retained as the ground water of soils and the 

hydration water of clays, and a part returns by evaporation to the 

atmosphere. According to an estimate by Sir John Murray, 2 the total 

annual rainfall upon all the land of the globe amounts to 29,347.4 

cubic miles, and of this quantity 6,524 cubic miles drain off through 

rivers to the sea. A cubic mile of river water weighs 4,205,650,000 

tons, approximately, and carries in solution, on the average, about 

420,000 tons of foreign matter. In all, about 2,735,000,000 tons of 

solid substances are thus carried annually to the ocean.3 Suspended 

sediments, the mechanical load of streams, are not included in this 

estimate; only the dissolved matter is considered, and that represents the chemical work which the percolating waters have done.

Although the minerals which form the rocky crust of the earth are 

relatively insoluble, they are not absolutely so. The feldspars are 

especially susceptible to change through aqueous agencies, yielding 

up their lime or alkalies to percolating water and forming a residue 

of clay. Rain water, as we-have already seen, contains carbonic acid 

in solution, and that impurity increases its solvent power, particularly 

with regard to limestones. The moment that water leaves the 

atmosphere and enters the porous earth its chemical and solvent 

activities begin, and continue, probably without interruption, until 

it reaches the sea. The character and extent of the work thus done 

varies with local conditions, such as temperature, the nature of the 

minerals encountered, and so on; but it is never zero. Sometimes 

larger and sometimes smaller, it varies from time to time and place 

to place. The entire process of weathering will be considered more 

fully later; we Lave now to study the nature of the dissolved matter 

alone, or, in other words, the composition of rivers and lakes. The 

data are abundant, but unfortunately are complicated by a lack

1 Excluding those belonging to closed basins.

2 Scottish Gcog. Mag., voL 3, p. 65,1887.

3 Estimates by F. W. Clarke (A preliminary study of chemical denudation: Smithsoiiian Misc. Coll., 

vol. 56, No. 5,1910). Murray's figures are 762,587 tons per cubic mile, and nearly 5,000,000,000 tons in tho 

total run-off. His analytical data were too few and too limited in range for a close computation.

59
60 DATA OF GEOCHEMISTRY.

of uniformity in the methods of statement, which are often unsatisfactory and even misleading. The analysis of a water can be reported 

in several different ways, as in grains per gallon or parts per million; 

in oxides, in supposititious salts, or in radicles; so that two analyses 

of the same material may seem to be totally dissimilar, although in 

reality they agree. Before we can compare analyses one with another we must reduce them to a common standard, for then only 

do their true differences appear. The task of reduction may be 

tedious, but it is profitable in the end.

STATEMENT OF ANALYSES.

In the usual statement of water analyses an essentially vicious 

mode of procedure has become so firmly established that it is difficult 

to set aside. For example, a water is found to contain sodium, 

potassium, calcium, magnesium, chlorine, and the radicles of sulphuric and carbonic acids; or, in ordinary parlance, three acids and 

four bases. If these are combined into salts at least 12 such compounds must be assumed, and there is no definite law by which 

their relative proportions can be calculated. A combination, however, is commonly taken for granted, and each chemist allots the 

several acids to the several bases according to his individual judgment. The 12 possible salts rarely appear in the final statement; 

all the chlorine may be assigned to the sodium and all the sulphuric 

acid to the lime, and the result is a meaningless chaos of assumptions 

and uncertainties. We can not be sure .that the chosen combinations 

are correct, and we know that in most analyses they are too few.

But are the radicles combined ? This is a point at issue. Although 

no complete theory, covering all the phenomena of solution, has yet 

been developed, it is the prevalent opinion, at least among physical 

chemists, that in dilute solutions the salts are dissociated into their 

ions, and that with the latter only can we legitimately deal. Whether 

this theory of dissociation shall ultimately stand or fall is a question 

which need not concern us now; we can use it without danger of 

error as a basis for the statement of analyses, putting our results 

in terms of ions which may or may not be actually combined. 1 Upon 

this foundation all water analyses can be rationally compared, 

with no unjustifiable assumptions and with all the real data reduced 

to the simplest uniform terms. We do not, however, get rid of all 

difficulties, and some of these must be met by pure conventions. For 

example, Is silica present in colloidal form, or as the silicic ion Si03 ? 

Are ferric oxide and alumina present as such, or in the ions of their

i The ionic form cf statement has been used in the Survey laboratory since 1S83. In Europe it has had 

strong advocacy from Prof. C. von Than, Min. pet. Mitt., vol. 11,1890, p. 487. It is now rapidly supplanting the older system. For an excellent discussion cf the statement of water analyses, see R. B. Dole, Jour. 

Ind. Ecg. Chorn., vol. 0,1914, p. 770.
LAKES AND RIVERS. Gl

salts ? The iron may represent ferrous carbonate, the alumina may 

be equivalent to alum; but as a rule the quantities found are so 

trivial that the true conditions can not be determined from the 

ratios between acidic and basic radicles. The unavoidable errors of 

analysis arc commonly too large to permit a final settlement of these 

questions; and only in exceptional cases can definite conclusions be 

drawn.

For convenience, then, we may regard these substances as colloidal oxides and tabulate them in that form.1 The procedure 

may not be rigorously exact, but the error in it is usually very 

small. If we consider an analysis as representing the composition 

of the anhydrous inorganic matter which is left when a water has 

been evaporated to dryness, the difficulty as regards iron disappears, 

for ferrous carbonate is then decomposed and ferric oxide remains. 

A similar difficulty in respect to the presence of bicarbonates also 

vanishes at the same time, for the bicarbonates of calcium and magnesium can only exist in solution and not in the anhydrous residues. 

If in a given water notable quantities of lime, magnesia, and carbonic acid are found, bicarbonic ions must be present, for without 

them the bases could not continue dissolved; but after evaporation 

only the normal salts remain. Sodium and potassium bicarbonates 

are not so readily broken down; but even with them it is better 

to compare the monocarbonates, so as to secure a uniformity of 

statement. In fact, some analysts report only normal salts, and 

others bicarbonates; so that for the comparison of different analyses 

we are compelled to adopt an adjustment such as that which is here 

proposed. In other words, we eliminate the variable factors and 

study the constants alone.

One other large variable remains to be considered the variation 

due to dilution. A given solution may be very dilute at one time and 

much more concentrated at another, and yet the mineral content of 

the water is possibly the same in both cases. For example, average 

ocean water contains 3.5 per cent of saline matter, while that of the 

Black Sea carries little more than hah7 as much; and yet the salts 

which the two waters yield upon evaporation are nearly, if not quite, 

identical. In some cases, as we shall presently see, it is desirable to 

compare waters directly; but in most instances it is also convenient 

to study the composition of the solid residues in percentage terms. 

In that way essential similarities are brought to light and the data 

become intelligible.

Before proceeding further, it may be well to consider a single 

water analysis in order to illustrate the various methods of statement. For this purpose I will take W. P. Headden's analysis of

1 Tliis rule applies to such waters only as aro considered in this chapter. To many volcanic \vators, 

goyser waters, mine waters, etc., it does not apply. Their discussion is loft to later chapters.
G2 DATA OF GEOCHEMISTRY.

water from Platte River near Greeley, Colo..1 which he himself 

states in several forms. In'the first column of the sub joined, table 

the results are given in oxides, etc., as in a mineral analysis, and in 

grains to the imperial gallon. In the second column they are stated 

in terms of salts, and I have here recalculated Headden's figures into 

parts per million of the water taken. Finally, in a third column I 

give, as proposed in the foregoing pages, the composition of the 

residue in radicles or ions and in percentages of total anhydrous 

inorganic solids.

Analysis of water stated in different forms.

Si02 . .........

Qn bU3 .. ..........

CO

01." ..........

Na20. .........

KaO.. .........

CaO.:.........

MgO.. .........

(FeAl)203 ......

Mn,0s......... " <>

Ignition. .......

Leas 0=01. ...

Grains 

per 

imperial 

gallon.

.... 0.891

.... 32.601

.... 4.554

.... 2.681

.... 11.463

. . . . .355

.... 13.117

. . . . 5. 530

. . . . .189

"IRQ

. . . . 2. 397

73. 967 

.... .604

73. 363

CaS04 .........

MgS04 .........

K2S04 .. ........

Na2S04 ........

NaCl...........

Na,C03 ... '.-....

Na2Si03 ........

(FeAl)203 .....

Ignition .......

Excess Si02 . . .

Parts per 

million.

. 457. 7

. 236. 0

9.4

62.5

63.2

. 156. 9

21. 9

2.7

2.7

04. o

1.3

1, 048. 5

Si02 ......

S04 .... ....

C03 .......

01.........

Na.........

K. ........

Ca. .......

Mg........

Ra03 . .....

' ' Ignition

Salinity, 1,

Per 

cent.

........ 1.26

........ 55.28

........ 8. 78

........ 3.79

........ 12.02

........ .41

........ 13.24

........ 4. 69

........ .53

100. 00

" omitted.

014 parts per

So far as appearance goes, these statements might represent three 

different waters; and yet the analytical data are the same. ° A change 

in the last column of SiO2 into the radicle Si03 would affect the other 

figures but slightly. The compactness and simplicity of the ionic 

form of statement are evident at a glance. Under it, as "salinity," 

I have given the concentration of the water in terms of parts per 

million. One. million parts of this water contain in solution 1,014 

parts of anhydrous, inorganic, solid matter.

THE INTERPRETATION OF ANALYSES.

In the interpretation of any water analysis the first question to ask 

is as to its accuracy. Every analysis is subject to errors, great or 

small, and in each individual instance it is important to decide 

whether its error is serious or negligible. When an analysis is 

stated in terms of salts, the errors are obscured, as in the smoothing 

of a curve, and an accurate estimate of its value is not possible. o In 

such a case the reputation of the analyst is the safest criterion upon 

which to base a judgment.

i Bull. Colorado Agr. Exper. Sta. No. 82,1905, p. 56.
LAKES AND RIVERS. 63

. When, however, an analysis is stated in terms of the radicles 

actually determined, a decision as to its value is much simpler. 

The negative or acid radicles and the positive or basic radicles must 

be chemically equivalent, at least within the limits of permissible 

experimental errors. To this rule, which applies to nearly all waters, 

there are some apparent but not real exceptions. If the basic 

radicles are much in excess of the acid, it is possible that a part of the 

alkaline ions may be balanced or held in equilibrium by silica; that 

is, the usually colloidal silica may represent an alkaline silicate, 

which, however, is hydrolyzed in solution. Some geyser waters of 

the Yellowstone National Park have this peculiarity. On the other 

hand, certain volcanic waters are strongly acid; and then it is necessary to assume the presence of hydrogen ions in order to completely balance the negative radicles. Another source of acidity 

is found in some mineral springs, in which the iron and aluminum 

are presumably in equilibrium as sulphates. The iron and aluminum 

must then be counted, not as colloids but as among the basic radicles. Examples of these exceptional waters are cited in chapter 6 

of this treatise, and demand no further attention here.

The calculations implied in the preceding paragraph are very 

simple, and may be based either upon the analysis as stated in parts 

per million or upon its percentages. The quantity found for each 

radicle is divided by its chemical equivalent, and the quotients for 

each group, acid or basic, are separately added together. The two 

sums should then be equal, or so nearly equal that the difference can 

be ascribed to the small, inevitable errors of analysis. For the 

univalent radicles Na, K, Cl, N03, and HCQ3 the chemical equivalent and the atomic weight are the same; for the bivalent radicles 

Ca, Mg, SO4 , and C03 the atomic weights should be halved. This 

is the usual procedure. H. Stabler, 1 however, has proposed a modification of the method, in which the quantities determined are multiplied by the reciprocals of the equivalents, which he calls the "reaction coefficients" of the radicles. The products so obtained, the 

'"reacting- values" of the radicles, are identical with the quotients 

of the ordinary process and must balance in the same way. A table 

of Stabier's coefficients may save some labor when large numbers of 

analyses are to be discussed, but the economy is probably small.

The interpretation of a water analysis, then, is founded upon a 

study of equilibria., Even the hypothetical combination of the 

radicles is a crude attempt at such a study an attempt, however, 

which, as we have already seen, is based ordinarily upon unverifiable 

assumptions. I speak now, of course, of such waters as commonly 

occur in nature. A solution of a single salt, or one in which, as in 

certain brines, one salt overwhelmingly predominates, is obviously

i Water-Supply Paper TJ. S. Cool. Survey No. 274,1911, pp. 165-1S1.
64 DATA OF GEOCHEMISTRY.

easy to deal with. A more refined attack upon the problem of interpretation has been made by Chase Palmer, 1 who has. examined in 

detail the relations between the equivalent ratios or reacting values 

described above, and so correlated the analyses with the properties 

of the waters analyzed. His procedure, briefly, is as follows: Two 

fundamental properties are recognized namely, alkalinity and 

salinity, which are subdivided into groups. Salinity is measured by 

the sum of the strong-acid radicles, S04 , Cl, and N03 , which balance 

an equivalent number of basic radicles. If the basic radicles are 

partly or wholly alkaline, that is, Na or K, their proportion of the 

salinity is said to be primary. The remaining salinity, due to the 

radicles Ca, Mg, and Fe" is called secondary. If, however, the acid 

radicles are in excess of the basic, tertiary salinity or acidity appears, 

and hydrogen ions must be taken into account. When the alkaline 

radicles exceed those of the strong acids, their excess is the measure of primary alkalinity, which represents hydrolyzed carbonates or 

bicarbonates. The weak-acid radicles C03 and HC03, which balance 

any excess of the alkaline earths over .the stronger acids, produce 

secondary alkalinity.

Upon these properties Palmer has developed a classification of 

natural waters, which correlates them with 'their geologic origin. 

Waters issuing from areas of crystalline, feldspathic rocks are characterized by high primary alkalinity, low concentration, and a 

notable proportion of silica. Waters from sedimentary regions, 

especially where limestone is abundant, show secondary alkalinity. 

Ocean water and other similar brines are almost entirely saline, and 

alkalinity is nearly or even wholly wanting in them. Palmer gives 

numerous, carefully worked out, illustrations of the applicability of 

his method of discussion to geochemical problems, but the details 

can not well be presented here.

When water first emerges from the earth as a spring its mineral 

composition is dependent upon local conditions.. Some spring waters 

are exceedingly dilute; others are heavily charged with saline impurities. To the subject of "mineral" springs, a separate chapter will 

be given, and only a few analyses of spring water, all taken from the 

records of the United States Geological Survey, need be given here. 

They represent the beginnings of streams and care therefore significant in this connection. All these analyses are reduced to a uniform 

standard, in accordance with the rules laid down in the preceding 

pages.2

1 The geochemical interpretation of water analyses: Bull. U. S. Geol. Survey No. 479, 1911. See also 

G. S. Rogers, Econ. Geology, vol. 12, 1917, p. 56.

2 Innumerable analyses of wells, springs, and underground waters generally are to be found scattered 

through the literature. See for example, S. W. McCallie, Bull. Geol. Survey Georgia No. 15, 1908, and 

E. Bartow, Bull. Univ. Illinois, vol. 6, No. 3,1908.
LAKES AND RIVEES.

Analyses of spring water.

A. Spring near Magnet Cove, Arkansas. Analysis by H. N. Stokos.

B. Spring 1 mile west of Santa Fe, New Mexico. Analysis by F. W. Clarke.

C. Spring near Mountain City, Tennessee. Analysis by T. M. Chatard.

D. Caledonia Spring, Caledonia, New York. Analysis by H. N. Stokes.

E. Spring 3 miles west of Lowesville, North Carolina. Analysis by F. W. Clarke.

F. Spring near Mount Mica, Paris, Maine. Analysis by F. W. Clarke.

65

co,.... ......................

S04 ............. ..............

Cl........ ....................

Ca...........................

Mg.............................

Na........ ...... ..............

K....... .....................

Si02 . ........................

A1203 -- - -> ..............

Fe203 .. ......................

A

53.59

3.40

1.35

30.95

3.45

1.08

.63

5.55

100. 00 

. 224

B

47.14

6.67

4.18

22.67

6.17

1 5.32

7.85

100. 00 

280

c

27.29

16.37

1.50

14.39

2.23

f 5.72

\ 3.97

27.17

Trace.

1.36

100. 00 

80

D

11.73

31.62

22.28

19.49

3.25

10.62

.34

.67

100. 00 

925

E

12.15

51.86

.45

23.58

1.47

4.16

.34

5.99

100. 00

642

F

6.22

60.97

Trace.

22.37

2.62

4.32

.21

2.80

4Q

100. 00 

606

Some of these waters yield carbonates on evaporation, one yields 

mainly sulphates, and between the two extremes the carbonic and 

sulphuric radicles vary almost reciprocally. One water is characterized by its high proportion of chlorine and another by its large percentage of silica; but in all of them calcium is the dominant metal. In 

salinity they differ somewhat widely, but the most concentrated 

example contains only 925 parts per million, or 52 grains to the 

United States gallon, of foreign solids. It will be seen as we go 

farther that carbonate waters are the most common, for the reason 

that rain water brings carbonic acid from the air, and that substance 

is most active as a solvent of mineral matter.

CHANGES OF COMPOSITION.

As spring water flows from its source it rapidly changes in. character. It receives other water in the form of rain or of ground water 

flowing from the soil, and it blends with other rivulets to produce 

larger streams. Under certain conditions a part of its dissolved load 

may be precipitated, and the composition.of a river as it approaches 

the sea represents the aggregate effect of all these agencies. A river 

is the average of all its tributaries, plus rain and ground water, and 

many rivers show also the effects of contamination from towns and 

factories. Small streams are the most affected by local conditions, 

and show the greatest differences in composition; large rivers, as a 

rule, resemble one another more nearly.

How rapidly and how profoundly the composition of a river may 

be modified are well illustrated in Headden's bulletin, which I have

113750° 19 Bull. 695 5
66 DATA OF GEOCHEMISTRY.

already cited. 1 Cache la Poudre River in Colorado flows first through 

a rocky canyon, over bowlders of schist and granite, and thence 

emerges upon the Plains. Its waters are then diverted into ditches 

and reservoirs for purposes of irrigation, and finally reach the Platte 

near Greeley. In performing the work of irrigation they acquire a 

new load of solid matter, and the progressive changes in then: composition are clearly shown by Headden's analyses. Some of the latter 

I will cite, first, as Headden gives them in grains to the imperial gallon, 

and then in a second table reduced to'ions and percentages.

Analysis E is the one cited on page 62 to show different forms of 

statement. In all cases I omit Headden's figures for ''ignition," and 

deal with the anhydrous residues alone.

'Analyses of-water from Colorado rivers.

A. Cacho la Poudre River above tho north fork.

B. Cache la Poudre River water from faucet ia laboratory at Fort Collins.

C. Cache la Poudre River 2 miles above Greeley.

D. Cache la Poudre River 3 miles below Greeley.

E. Platto River below mouth of the Cacho la Poudre.

Grains per imperial gallon.

coa ..................................

S08 ......... ..........................

01.!.. ................................

CaO............. ......................

SrO..................................

MgO.. ...... ...........................

Na»0............ ......................

K26.... ..............................

SiO.,.. .................................

(Al,Fe)203 ............................

 i f *~v " Mno03 . ................................

Less 0-C1. . ..........................

A

0. 6029

.1946

.1037

.5238

Trace.

.1257

.3750

.0855

.6053

.0113

.0018

2. 6296 

.0234

2. 6062

D

2. 3731

1. 8699

.lOo5

3. 0364

.0223

, . 8857

. 6631

.1921

.6245

.0171

.0112

9. 8009 

.0238

9.7771

C

5.920

54. 970

2.770

18. 9'38

12. 190

14. 590

.451

1.035

.079

TVAPP

110.943

.624

110.319

D

5.087

30. 374

2.145

14. 087

5.592

9.117

.372

.951

.039

.078

67. 842 

.483

67. 3(59

E

4.554

32. 601

2.681

13. 117

5.530

11.463

.355

.891

.189

.189

71. 570 

.604

70. 966

Reduced analyses, in percentages.

C03 ..................................

S04 ............. ......................

CL. ..................................

Ca...................................

Sr.. ..................................

Mg...................................

Na.......... ..........................

K....................................

Si02 ............... ....................

R c\ 2O3 ..... ............................

31.91

9.07

4.03

14.53

2.93

10. 80

2.72

23.50

.51

100. 00

37

33.68

23.36

1.10

22.58

.19

5.53

5.12

1.66

6.49

.29

100. 00 

137

7.34

59.99

2.52

12.31

6.65

9.84

.34

.94

.07

100. 00 

1,571

10.34

3.19

15.00

5.00

10.09

.46

1.42

.17

100. 00

958

8.78

55.28

3.79

13.24

4.69

12.02

.41

1.26

.53

100. 00 

1,011

1 Bull. Colorado Agr. Exper. Sta. No. 82,1903.
LAKES AND EIVEKS. 67

We have here, first, a very pure mountain water, relatively high 

in carbonates and rich in silica. At the end of the series we have 

waters in which sulphates predominate and the proportion of silica 

is very low. The change is extremely great in all respects, and is 

partly due to the use of .the water for irrigating an originally arid soil 

containing much soluble matter. Probably when the soil shall have 

been thoroughly leached by long periods of cultivation the changes 

in the water will be less exaggerated. A similar alteration is also 

shown in Headden's analyses of water from Arkansas River, first at 

Canon City, where it emerges from the mountains, and second at 

RocKyford, nearly 100 miles below.1 The analyses are as follows, 

reduced to the common standard adopted in this memoir. Headden 

regards the silica" as present partly in the form of alkaline silicates, a 

supposition which is probably correct. For present purposes, however, the difference between SiO, and the SiO3 radicle may be neglected .

Analyses of water fr om Arkansas River at two points in Colorado.

G03 ..... ...............................................

S04 . ..................................................

Cl...... ...... ..........................................

Ca......................... ............................

Mg..... ................................................

Na

K.......... ............................................

Si02 .. .................................................

K-XV-... ..............................................

Canon City.

37.55

14.62

3.77

20.24

5.13

9.57

.60

8 1Q

.33

100. 00

148

Kockyford.

2.65

60.69

4 8Q

12.78

3.76

14.5090

45

100. 00 

2,134

Changes of a different order are shown by the waters of the River 

Chelif, in Algeria, according to the investigation by L. Ville. 2 This 

stream flows through an arid region, in which incrustations or efflorescences of salt and gypsum abound. Lower in its course it receives 

affluents much poorer in mineral matter, and its character, at least as 

regards salinity, is modified. Ville's analyses reduced to a modern 

standard are as follows:

1 Bull. Colorado Agr. Exper. Sta. No. 82,1903. Headden also gives analyses of water from St. Vrain, 

Big Thompson, Boulder, and Clear creeks, and from many reservoirs, irrigating ditches, and wells. See 

also Am. Jour. Sci., 4tb/ser., vol. 16,1903, p. 169.

a Bull. Soc. ge"ol. Franco, 2d ser., vol. 14,1857, p. 352. A later analysis by Balland is given in Jour. Chom. 

Soc., vol. 36,1879, p. 690, abstract. Still another, by F. do Marigny, is cited by Roth. In Annalos dos 

mines, 5th ser., vol. 11,1857, p. 667, Marigny gives analyses of two other Algerian rivers.
68 DATA OF GEOCHEMISTRY.

Analyses of ivater from River CMlif, Algeria.

A. Sample taken at Ksar-Boghari during extreme low water. 

B. Sample taken at the same point a few days later, after a rise. 

C. Sample from Orleansville, much farther downstream.

C03 ............ ........................................

so.....................................................

Cl...... ...............................................

Ca. ...................................................

Mg.. ..................................................

Na... ..................................................

Si02 . .................................................

Fe203 ..................................................

Salinity, parts per million ..............................

A

0.93

40.36

26.40

7.46

4.12

20.64

.06

.03

100. 00 

6,670

B

1.11

25.87

39i28

6.63

4.42

22.61

.04

.04

100. 00 

5,342

c

9.31

29.64

26.54

11.85

4.11

17.03

.34

1.18

100. 00 

1,182

The effect of dilution by affluents is shown by analysis C; but the 

interesting feature of the series is the difference between high and 

low water at Ksar-Boghari. Ville attributes this difference to the 

fact that salt is much more soluble than gypsum and that therefore 

during a flood it is dissolved out more freely and more rapidly from 

the soil. At low water sulphates are in excess of chlorides; at high 

water the reverse is true.

> The examples thus far cited serve to show the danger of attempting 

to draw general conclusions from a single analysis of a water, especially when the latter is collected at only one point. If we wish to 

determine the total load carried by a river to the ocean, the samples 

should be taken as near as possible to its mouth, but far enough upstream to avoid tidal contamination; and the analyses should be 

numerous enough to give a fair average result. Without such precautions no valid conclusions can be reached. The data must be 

adequate to the purpose in view a condition which is not always

fulfilled. ' 

ANALYSES OF RIVER WATERS.

Many analyses of river and lake water are to be found scattered 

through chemical and geological literature. Only a part of the 

material can be considered here, and preference will be given, but 

not exclusively, to analyses not cited in the classical works of J. Roth 

and G. Bischof. Many of the analyses were made in the laboratories 

of the United States Geological Survey, and especially in those of the 

water-resources branch. The work of that branch, in this particular 

direction, is mainly but not exclusively represented by six publications, 1 in which a large number of American rivers have been studied

1 Water-Supply Papers No. 236, by R. B. Dole, 1909; No. 237, by Walton Van Winkle and F. M. Eaton, 

1910; No. 239, by W. D. Collins, 1910; No. 273, by H. N. Parker and E. H. S. Bailey, 1911; and Nos. 339 

and 363, by W. Van Winkle, 1914. Water-Supply Paper No. 274, by Herman Stabler, also contains many 

analyses of river waters.
LAKES AND RIVERS. 69

with remarkable exhaustiveness. For each river or lake many 

analyses were made, in such a manner as to give its average composition for an entire year. As a rule, samples of water were taken 

daily and combined into composite samples of seven to ten, which 

were analyzed. The analyses, however, some thousands in number, 

are not absolutely complete. Alumina, for example, was not determined, and the alkalies, as a rule, were weighed together and calculated as all sodium. Later work, by Chase Palmer, corrected the 

latter omission, and I have been able to recalculate the published 

analyses with the introduction of Palmer's figures 1 for Na and K. 

All the analyses cited in the following pages have been reduced to 

the uniform standard which was outlined in the preceding pages; 

but the original figures can usually be found through the references 

to the literature. In addition to the substances enumerated in the 

analyses, waters contain many other constituents in minute, almost 

undeterminable traces. One of those, fluorine, has recently been 

determined in several river waters by A. Gautier and P. Clausmann.2 

The quantities found ranged from 0.02 to 0.6 milligram per liter, 

being highest in waters emerging from primitive rocks.

THE ST. LAWRENCE BASIN.

For geological purposes a regional classification of the data would 

seem to be the most practicable, for the members of a river system 

belong naturally together. Taking North American rivers first in 

order, let us begin with the St. Lawrence and its tributaries. The 

selected analyses are as follows:

i Supplied by Palmer. For details see Bull. U. S. Geol. Survey No. 479, 1911. 

» Compt. Rend., vol. 158,1914, p. 1389.
70 DATA OF GEOCHEMISTRY.

Analyses of water from the St. Lawrence basin.

A. Lake Superior at Sault Ste. Marie. Mean of 11 analyses of samples taken monthly between September 22,1906, and August 22,1907. Other analyses of Lake Superior water have been made by W. A. Noyes, 

Eleventh Ann. Rept. Minnesota Geol. Survey, 1882, p. 174; by W. F. Jackman, cited by A. C. Lane in' 

Water-Supply Paper TJ. S. Geol. Survey No. 31,1899, p. 27; and by G. L. Heath, Rept. State Board Geol. 

Survey Michigan, 1903, p. 119.

B. Lake Michigan at St. Ignace. Mean of 11 samples taken between September 20, 1900, and August. 

20,1907. Analyses of Lake Michigan water at Milwaukee and of Milwaukee River, by G. Bode, are pul> 

lished in Geology of Wisconsin, vol. 1, 18S3, p. 308. Another analysis of the lake water, by J. H. Long, 

is given in Report on the boiler waters of the Chicago, Burlington & Quincy Railroad, published by that 

company in 1888.

C. Lake Huron at Port Huron. Mean of 9 samples taken between September 21,1906, and June 21,1907.

D. Lake Erie at Buffalo. Mean of 11 samples taken between September 19, 1906, and August 28,1907.

E. The St. Lawrence at Ogdensburg. Mean of 11 samples taken between September 18, 1906, and 

August 19, 1907.

Analyses A to E by R. B. Dole and M. G. Roberts. See Water-Supply Paper U. S. Geol. Survey No. 

236.

F. The St. Lawrence at Pointe des Cascades, near Vaudreuil, above Montreal. Analysis by T. Sterry 

Hunt, Philos. Mag., 4th ser., vol. 13,1857, p. 239.

G. The St. Lawrence opposite Montreal. Analysis by Norman Tate, cited by T. Mellard Reade, in 

Evolution of earth structure, 1903.

rr»

so4 ~ ................. ci..........:.........

N03 ........... ........

Ca. .:................

Mg.. ...... ...........

Na....................

K....................

Si02 ...................

Fe203 - ---------------

Salinity, parts per milA

47.42

3.62

1.89

.86

22.42

5.35

| 5.52

12. 76

.16

100. 00 

0.60,

B

49.45

6.15

2.31

.26

22.21

7.01

} 4.02

8.54

.05

100. 00 

118

C

47.26

5.77

2.42

.38

22.33

6.52

1 4.10

11.16

.06

100. 00 

108

D

44.70

9.83

6.58

.23

23.45

5.75

1 4.92

4.46

.08

100. 00 

133

E

45.70

9.15

5.87

.23

23.66

5.49

1 4.81

5.03

.06

100. 00 

134

F

41.66

5.19

1.51

20.08

4.52

3.20

.72

23.12

100. 00 

160

G

44. 43

11.17

2.41

20.67

fi 44

4.87

10.01

100. 00 

148

The following analyses represent tributaries to the St. Lawrence : T

Analyses of water from tributaries to the St. Lawrence.

H. Pigeon River, Minnesota. Analysis by W. A. Noyes, Eleventh Ann. Rept. Minnesota Geol. Survey, 

1882, p. 174.

I. Grand River at Grand Rapids, Michigan. Mean of 34 composites of samples taken between October 

1,1908, and October 5,1907. Analyses by R. B. Dole, M. G. Roberts, C. Palmer, and W. D. Collins.

J. Kalamazoo River near Kalamazoo, Michigan. Mean of 35 composites, September 19, 1906, to September 21,1907. Same analysts as under I.

K. Maumee River at Toledo, Ohio. Mean of 30 composites taken between September 9, 1900, and 

October 7,1907. Dole, Roberts, and Palmer, analysts.

L. Genesee River at Rochester, New York. Analysis by C. F. Chandler, cited by I. C. Russell in Mon. 

U. S. Geol. Survey, vol. 11,1885, opp. p. 176.

M. Oswegatchie River at Ogdensburg, New York. Mean of 35 composites, September 9, 1906, to September 9,1907. Same analysts as under I.

N. Ottawa River at Ottawa, Canada. High water, July, 1907. Analysis by F. T. Shutt and A. G. 

Spencer, Trans. Roy. Soc. Canada, 3d ser., vol. 2,1908, p. 175. Another incomplete analysis is also given.

0. Lake Champlain. Average of five analyses of samples taken in the broad lake, by M. 0. Leighton, 

Water-Supply Paper U. S. Gool. Survey No. 121, 1905. This paper contains analyses of water from the 

upper end of the lake, of Bouquet River, and of Ticonderoga Creek.

Analyses I, J, K, and M, from Water-Supply Paper 230, contain corrections for the alkalies as furnished 

by Palmer. An earlier analysis of water from the Maumee, by Chandler, and one of the Ottawa, by T. S. 

Hunt, are given in the first edition of this book (Bulletin 330).

1 Other tributaries that have been analyzed are as follows: Goose Lake, Michigan (Geol. Survey Michigan, 

vol. 8, pt. 3, 1903, p. 235); Torch Lake, Portage Lake, Pine River, Thunder River (Rept. State Board 

Geol. Survey Michigan, 1903); Traverse Bay, Detroit, Shiawassee, Grand, Cass, Chippewa, Tittabawussce, 

and Boardman rivers, Manistee and Muskegon lakes, cited by A. C. Lane in Water-Supply Paper U S. 

Geol. Survey No. 31,-1903.
LAKES AND RIVERS. 71

Analyses of water from tributaries to the St. Lawrence Continued.

CO,.. ........ ......

SO4 . ................

01. .................

N08 .. ...............

Ga...................

Mg.. ...............

Na. .................

K. .................

Si02 .................

FeA-- ..............

Al ft

Salinity, parts per 

million............

H

42.00

4.09

6.09

18.08

5.74

5.13

2.55

14.15

1. 57-

100. 00 

51

I

44.37"

12.88

3.00

.89

21.85

7.42

3.20

8Q

5.46

.04

100.00

258

J

47.32

9.54

1.41

.79

22.82

7.47

2.87

.70

7.05

.03

100. 00

242

K

29.63

16. 25

13.55

I 52

19.29

5.44

6.79

1.62

5.78

.13

100. 00 

298

L

37.94

25.29

1.41

24.48

5.29

2.59

1.35

.82

1 .83

 *

100. 00 

170

M

39. 10

32 24

.59

.59

19. 40

5.23

6.57

1.80

'14.03

.45

100.00

77

N

35.44

8.57

1.42

16.58

4.74

4.51

1 "1Q

20.03

W. 12 *

100. 00 

45

0

45. 81

11. 03

1.78

21. 19

4 91

1 8.80

5.58

} 1.60

'

100. 00 

67

a Includes small amounts of P04 and MnjO*.

Between these waters there are distinct resemblances, in that carbonates are the predominating salts and calcium is the chief metal. 

Ottawa River is characterized by high silica; but the Genesee and the 

Mauniee, which flow through areas of sedimentary rocks, contain a 

larger proportion of sulphates. The increase in salinity or concentration in passing from Pigeon River, at the head of Lake Superior, 

to the St. Lawrence at Montreal is also noteworthy. The two Montreal analyses, F and G, are, however, far from concordant and can 

not be given much weight.

According to estimates made by engineers of the United States 

Army, the flow of the St. Lawrence past Ogdensburg is 248,518 cubic 

feet per second. This, with a salinity of 134 parts per million, corresponds to a transport of dissolved matter of 29,722,000 metric tons 

annually. The area drained, exclusive of water surface, is 286,900 

square miles, and from each square mile 103.6 tons are removed in 

solution each year.

THE ATLANTIC SLOPE.

For the rivers and lakes of the Atlantic slope south of the St. Lawrence the data are now fairly abundant. The following analyses are 

the most useful. In all of them bicarbonates are reduced to normal 

form, and organic matter is omitted from the calculation.
72 DATA OF GEOCHEMISTRY.

Analyses of waters of Atlantic slope I.

A. Moosehead Lake, Maine.

B. Eangeley Lake, Maine.

C. Androscoggin River at Brunswick, Maine, above the falls. Average of 38 analyses of weekly samples 

taken between April 25,1905, and January 16, 1906. Analyses A, B, and C made by F. C. Robinson, for 

the water-resources branch of the United States Geological Survey. C as recalculated by Dole in WaterSupply Paper 236. The undetermined C03 is computed to satisfy bases.

D. Merrimack River above Concord, New Hampshire. Analysis by H. E. Barnard for the water-resources 

branch of the Geological Survey.

E. Hudson River at Hudson, New York. Mean analysis of 36 weekly composites taken between September 16,1906, and September 22,1907. Analyses by R. B. Dole, M. G. Roberts, C. Palmer, and W. D. 

Collins, Water-Supply Paper 238, 1909. Analyses by C. F. Chandler of water from the Hudson and its 

tributaries, the Mohawk and the Croton, are cited in the first edition of this book (Bulletin 330).

F. Raritan River at Bound Brook, New Jersey. Mean of 35 composite samples taken between September 10, 1906, and September 12, 1907. Same analysts and reference as under E. Analyses of several 

New Jersey streams are given by A. H. Chester in the report on water supply, New Jersey Geol. Survey 

1894. An analysis of water from Passaic River, by E. N. Horsford, is published in Geology of New Jersey, 

186S, p. 703; and another by H. Wurtz in Am. Chemist, vol. 4,1S73, pp. 99,133.

. G. Delaware River at Lainbertville, New Jersey. Mean of 34 composite samples, September 8, 1906, 

to September 12,1907. Same analysts and reference as under E. A similar average analysis of the Lehigh 

is also given by Dole. For an earlier, single analysis of Delaware water see H. Wurtz, Am. Jour. Sci., 

2d ser., vol. 22,1856, p. 125. Analyses of water from the Schuylkill are given by C. M. Cresson in a report 

entitled "Results of examinations of water from the River Schuylkill," Philadelphia, 1875.

H. Susquehanna River, at Danville, Pennsylvania. Mean of 36 composite samples, September 10,1906, 

to September 17,1907. Same analysts and reference as .under E. Similar annual averages for the river at 

West Pittston and Williamsport are also given by Dole. The Susquehanna shows the effects of contamination by coal-mine drainage.

In analyses E, F, G, and H the alkalies are given as corrected by Palmer.

rr\

80t... ..............

Gl. .................

N03 - ..............

Ca. ................

Mg.'.. ..............

Na. .................

K. ................. Q-in

A1203 ..............

Fe203 -- ............

Salinity, parts per

A

26.83

14.46

13.83

14.94

1.80

12.79

4.29

9.68

j 1.38

'

100. 00 

14.5

B

26.53

13.08

12.72

14.78

1.69

11.63

4.42

13.33

1 1.82

100. 00 

16.5

C

20.29

24.85

4.76

15.33

2.27

5.17

2.07

18.63

} 6.63

'

100. 00 .

48.3

D

28.15

12.78

8.78

17.14

4.18

16.16

Trace.

18.14

1.34

3.33

100. 00 

170

E

35.45

15.84

3.96

.79

20.79

3.76

6.53

1.78

10.90

.20

100. 00 

108

F

29.48

14.08

5.52

2.23

14.08

4.58

9.27

1.76

18.77

.23

100. 00

85

G

32.95

17.49

4.23

1.60

17.49

4.81

6.70

1.46

13. 12

.15

100. 00 

70

H

23.54

27.53

7 1Q

3 09

18.64

4.08

6.84

1 33

7.72

.11

100. 00 

112

Analyses A and B are remarkable because of their relatively high 

content in alkaline chlorides. These waters, however, are very dilute, 

and the absolute quantity of chlorides in them is probably no more 

than they would receive from rainfall. The Androscoggin rises in 

the Rangeley Lakes, but the composition of its water is profoundly 

modified by drainage from factories and pulp mills. Its headwaters, 

flowing from a region of crystalline rocks, mainly granitic, are remarkably pure.
LAKES AND RIVERS. 73

Analysis of waters of Atlantic slope II.

I. Potomac River at Cumberland, Maryland. Mean composition of 36 composite samples taken between 

September 11, 1906, and September 14, 1907. Analyses by Dole, Roberts, Palmer, and Collins.

J. Shcnandoah River at Millville, West Virginia. Composite of 30 samples, September 12, 1906, to 

September 9,1907. Same analysts as under I.

K. Potomac River above Great Falls, Maryland. Average of twelve samples taken at intervals of one 

month between April, 1904, and April, 1905. Analyses by Raymond Cutwater, Water-Supply Paper 

U. S. Geol. Survey No. 192, 1907, pp. 296-297. This report contains thirty-four other analyses of water 

from the upper Potomac and its important tributaries.

L. James River at Richmond, Virginia. Composite of 36 samples, September 10, 1906, to September 

9,1907. Same analysts as under I. A thesis by A. F. White, Washington and Lee University, 1906, contains partial'analyses of tributaries of the James near Lexington, Virginia. See also an analysis of James 

River water by W. H. Taylor, Rcpt. to Richmond Board of Health, 1877, cited in the first edition of this 

book (Bulletin 330).

M. Dan River at South Boston, Virginia. Composite of 21 samples, September 3, 1906, to May 2,1907. 

Dole, Roberts, and Palmer, analysts.

N. Roanoke River at Randolph, Virginia. Composite of 20 samples, September 7,1906, to May 12,1907. 

Same analysts as under M.

0. Neuse River at Raleigh, North Carolina. Composite of 36 samples, October 1, 1906, to October 19, 

1907. Same analysts as under I.

All the analyses in this table except K are recalculated from Water-Supply Paper 236, with the alkali 

determinations as corrected by Palmer. Each composite sample represents ten daily collections.

003.................

so4 ................

Cl....... ............

NO,.. ..............

Ca. .................

Mg..................

Na. ................

K. ..................

Si02 . ...............

A1203 - -- ............

Fe2 03 - ..............

Salinity, parts per 

million. ..........

I

13.69

44.85

4.95

.70

18.56

3.56

6.11

1.08

6.35

.15

100. 00 

130

3

47.22

4.43

2.14

1.86

22.85

5.86

3.86

1.00

10.71

.07

100. 00 

140

K

44.37

7.68

4.44

27.40

4.08

2.83

.55

4.56

} 4.09 '

100. 00 

115

L

36.02

8.68

2.81

.37

17.10

3.66

7.20

1.34

21.98

.85

100. 00 

89

M

25.43

5.34

5.03

1.73

8.79

2.35

9.10

2.04

37.68

2.51

100. 00 

71

N

34.99

5.90

9 ^

.67

12.74

4.69

6.70

1.47

28.15

1.74

100. 00 

79

0

24.93

4.90

Pi 34.

.43

8.50

2.59

10.09

1 87

37.47

2.88

100. 00 

73

The first three analyses in the foregoing table are peculiarly suggestive. The Potomac at Cumberland shows the effect of drainage 

from coal mines. The Shenandoah adds to the Potomac a large 

volume of water which is little contaminated and which represents 

to a considerable extent the influence of a limestone country. At 

Great Falls the Potomac, modified by its numerous affluents, approaches the normal or average type of river waters. According 

to estimates made by Outwater the Potomac annually carries past 

Point of Rocks 771,000,000 kilograms of dissolved matter and 

212,000,000 kilograms of solids in suspension, or sediments. The 

sum of the two quantities is 983,000 metric tons, or a little over 102 

metric tons per square mile of the territory drained. The dissolved 

matter corresponds to 80 tons per square mile.
74 DATA OF GEOCHEMISTRY.

Analysis of ivaters of Atlantic slope III. 

^

P. Cape Fear River at Wilmington, North Carolina. Mean analysis of 30 composite samples taken 

between October 2, 1906, and October 9, 1907. Dole, Roberts, Palmer, and Collins, analysts. Water 

probably modified by tidal contamination.

Q. Peedee River near Peedee, North Carolina. Mean of 24 composites, October 26,1906, to October 19, 

1907. Dole, Palmer, Collins, and J. R. Evans, analysts.

R. Saluda River near Columbia, South Carolina. Mean of 16 composites, October 27, 1906, to May 3, 

1907. Evans, analyst.

S. Wateree River near Camden, South Carolina. Mean of 34 composites, October 21, 1906, to October 

25,1907. Dole, Evans, Palmer, and Collins, analysts.

T. Savannah River near Augusta, Georgia. Mean of 34 composites, October 25,1906, to October 22,1907. 

Same analysts as under Q.

U. Ocmulgee River near Macon, Georgia. Mean of 33 composites, October 19,1906, to -October 21,1907. 

Same analysts as under Q.

V. Oconee River near Dublin, Georgia. Mean of 32 composites, October 18, 1906, to October 17, 1907. 

Same analysts as under Q. Analyses P to V are from Water-Supply Paper 236. Potassium determinations 

supplied by Palmer.

W. Lake Okechobee, Florida. Analysis by W. T. Read, cited by R. B. Dole in Carnegie Inst. Washington Pub. No. 182,1914, p. 76. Bicarbonates reduced to normal carbonates, organic matter omitted.

r\r\ ou3 . ...............

so4 ......... ........ ci..................

N03.................

Ca.. .................

Mg.. ...............

Na. .................

K. .................

Si02 .. ...............

FeA 

Salinity, parts per 

niillioiis ...........

P

26.57

6.91

12.52

.43

10.80

3. 24

14.04

1.95

21. 38

2.16

100. 00 

57

Q

23.33

5.95

4.60

.89

10.25

1.93

10.99

2.82

38.65

.59

100. 00 

69

R

26.01

8.01

5.61

.69

13.46

2.08

| 9.62

33.65

.87

100. 00 

62

B

25.15

4.22

. .60

Q 4Q

2.71

10.84

2.41

37. 65-

.60

100. 00 

73

T

22.49

9.12

3.19

.91

8.67

1. 22

14. 42

4.12

34.95

Q1

100. 00 

60

U

21.06

7.48

4.28

1.07

9.62

1.83

10. 23

2.90

39.70

1.83

100. 00 

69

V

26.00

8.86

4.86

1.43

12.14

2.29

10.14

2.85

30.00

1 43

100. 00 

68

w

35.96

4 fiQ

18.00

.06

1Q Q3

4.50

10.28

1.28

5.27

03

100. 00 

155.6

The water of Lake Okechobee is remarkably high in sodium and 

chlorine. Is this due to cyclic salt brought down in rain ?

Analyses of eastern tributaries to the Gulf of Mexico.

A. Flint River near Albany, Georgia. Mean analysis of 20 composite samples taken between October 

23, 1906, and May 12, 1907. J. R. Evans, analyst.

B. Chattahoochec River at West Point, Georgia. Mean of 34 composites, October 26,1906, to October, 

18, 1907. Dole, Evans, Palmer, and Collins, analysts.

C. Oostanaula River near Rome, Georgia. Mean of 31 composites, October 21,1906, to October 28,1907. 

Same analysts as under B.

D. Cahaba River near Birmingham, Alabama. Mean of 30 composites, November 1,1906, to November 

1, 1907. Same analysts as under B. For a single analysis of water from the Cahaba sec R. S. Hodges, 

^ Gcol. Survey Alabama, Underground water resources, 1907. This report contains many analyses of springs 

and wells.

E. Alabama River at Selma, Alabama. Mean of 33 composites, November 5,1906, to October 17,1907, 

Evans, Dole, Palmer, Collins, and W. Van Winkle, analysts.

F. Tombigbee River near Epes, Alabama. Mean of.33 composites, October 24,1906, to October 24,1907. 

Same analysts as under B.

G. Pearl River, iiaar Jackson, Mississippi. Mean of 32 composites, October 16,1900, to October 19,1907. 

Same analysts as under B.

All tho analyses in this table are recalculated from Water-Supply Paper 236 and include later alkali 

determinations by Palmer.
LAKES AND RIVERS. 

Analysis of eastern triqutaries to the Gulf of Mexico Continued.

C08 ..... ............

S04 .. ................

01. . .................

NOINUg- ...............

Ca. ................. Mg..... :............

Na.. .................

K........ ...........

SiO,- ...............

FeA- ..............

Salinity, parts per 

million. ............

'A

22.73

8.95

4.17

.90

13.12

2.09

} 10. 44

35. 77

1.83

100. 00 

G7

B

21.32

8.49

3.96

1.32

9.06

1.51

12.08

3.40

37.73

1.13

100. 00 

52

c

32. 06

5.04

2.21

.50

14.74

3.19

9.60

1.96

29.48

1.22

100. 00 

82

D

32.53

11.18

2.79

.76

16.52

3.17

8.78

3.18

20.33

.76

100. 00 

76

E

27.86

10.63

2.72

.83

15.35

3.42

11.33

2.12

24.79

.95

100. 00

82

F

33.34

C. 37

3.03

.61

18. 18

1.82

8.18

2.32

25.25

.90

100. 00 

94

G

25.29

10.31

5.48

1.12

11.43

1.77

11. 59

3.22

28.99

-.80

100. 00 

59

A glance at the foregoing table and the two immediately preceding 

it reveals a remarkable similarity between the waters of the southern 

rivers from the James to the Pearl inclusive. All are low in salinity 

and relatively high in silica and the alkalies. In several of-the 

analyses the alkaline radicles are in excess of calcium. River waters, 

in short, seem to exhibit distinct regional peculiarities, which, in 

most cases, if not in all, are due to the geology of the region traversed. 

These waters, with one or two exceptions, flow from areas of Crystalline schists, and owe little to sedimentary environments.

THE MISSISSIPPI BASIN.

For the great river system of the Mississippi the chemical data are 

abundant, but of very unequal value. The river itself has been 

studied from near its source to near its mouth, and the waters of 

many tributaries have also been analyzed. Taldng the Mississippi 

itself first, the useful data are as follows, arranged in order going 

southward.
76 DATA OF GEOCHEMISTRY.

Analyses of water from Mississippi River.a

A. Mississippi River at Brainerd, Minnesota. Analysis by C. F. Sidener, Thirteenth Ann. Rcpt. Geol. 

Nat. Hist. Survey Minnesota, 1884, .p. 102.

B. Mississippi River at Minneapolis, Minnesota. Average of 35 analyses, by W. M. Barr, H. S. Spaulding, and W. Van Winkle, of samples each formed by ten daily collections between September 10, 1906, 

and September 11, 1907.

C. Mississippi River near Moline, Illinois. Mean of 18 composite samples taken between February 1, 

and July 31, 1906. W. D. Collins, analyst.

D. Mississippi River near Quincy, Illinois. Mean of 36 composite samples taken between August 1, 

1906, and July 31, 1907. W. D. Collins, analyst.

E. Mississippi River near Chester, Illinois. Mean of 31 composite samples taken between August 1, 

1906, and July 31, 1907. W. D. Collins, analyst.

F. Mississippi River at Memphis, Tennessee. Mean of 35 composite samples taken between January 

10,1907, and January 1,1908. Analyses by J. R. Evans, W. Van Winkle, R. B. Dole, Chase Palmer, and 

W. D. Collins. Later alkali determinations by Palmer.

G. Mississippi River above Carrolton, Louisiana. Analysis by C. H. Stone, Science, vol. 22, 1905, p. 

472. Sample taken 6 feet below surface. Recalculated from bicarbonates.

H. Mississippi River at New Orleans. Mean of 52 composite samples taken daily between April 29, 

1905, and April 28, 1906. . J. S. Porter, analyst.

The analyses, except A and G, are recalculated from the figures given by Collins in Water-Supply Paper 

239 and Dole in Water-Supply Paper 236.

C08 ................

S04 . .................. ci.................. N03 .:...............

PO

Ca......... ..........

Mg.. ...............

Na. .................

K.. ................

Si02 ....... ..........

Al C\

FeA................

Mn304 ...............

Salinity, parts per

A

51.65

1.05

.48

22.94

4.09

5.14

1.75

9.40

2.01

1.49

100. 00 

195

B

48.03

9.35

,83

.73

20.77

7.27

1 5.19

7.78

.05

100. 00 

200

C

42.27

13.58

2.09

1.01

18.68

7.35

} 5.65

9.09

.28

'

100. 00 

179

D

43.15

12.55

2.21

1.10

18.06

8.03

| 5.52

9.03

.35

100. 00 

203

E

33.23

21.74

3.79

1.05

17.08

6.22

1 8.15

8.54

.20

100. 00 

269

F

30.23

20.50

4.10

.81

17.16

5.72

8.09

1.52

11.44

.43

100. 00 

202

G

30.27

19.69

11.05

.27

20.25

4.66

6.86

1.57

5.07

.12

.08

.11

100. 00 

146

H

34.98

15.37

6.21

1.60

20.50

' 5.38

| 8.33

7.05

45

10

100. 00 

166

o For two analyses of Mississippi water, taken above and below Minneapolis, see J. A. Dodge, Tenth 

Ann. Rept. Geol. Nat. Hist. Survey Minnesota, 1882, p. 207. These analyses are given in the first edition 

of this book. Bailey Willis (Jour. Geology, vol. 1,1893, p. 509) cites some imperfect analyses of the Mississippi and Missouri near St. Louis. Iowa Geol. Survey, vol. 6, 1896, p. 365, contains other analyses of 

Mississippi water, and also of Missouri, Cedar, Des Moines, Coon, Boyer, Wapsipinicon, Skunk, Chariton, 

Grand, Nodaway, and West Nishnabotna rivers. These too are incomplete. The early analyses of Mississippi water by Avequin and by Jones are of no value for present purposes. Partial analyses, containing 

some useful data, are given in Report of the sewage and water board, New Orleans, 1903.

the lower Mississippi near New Orleans.

These relate to

This table tells a definite story. The upper Mississippi is low in 

sulphates and chlorides, which tend to accumulate in the lower 

stream. The chlorides come in part from human contamination, a 

subject to be considered later; but more largely, together with sulphates, from western tributaries, notably from the Missouri. At 

New Orleans, also, there is probably some "cyclic sodium" brought 

in rainfall from the Gulf of Mexico. On the whole, carbonates predominate in the Mississippi water, with all else subordinate.
LAKES AND RIVERS. 77

The next table gives analyses of waters tributary to the uppef 

Mississippi within the States of Minnesota and Wisconsin.1

Analyses of waters tributary to upper Mississippi River.

A. Lake Minnetonka. Analysis by W. A. Noycs, Geology of Minnesota, vol. 2, 1888, p. 311.

B. Mille Lacs Lake. Analysis by J. A. Dodge, Geology of Minnesota, voL 4,1899, p. 38.

C. Bigstono Lake. Analysis by C. F. Sidener, Thirteenth Ann. Rept. Geol. Nat. Hist. Survey Minnesota, 1884, p. 98. Empties into Minnesota River.

D. Heron Lake: Analysis by Noycs, Eleventh Ann. Rept. Gcol. Nat. Hist. Survey Minnesota, 1882, 

p. 173. Empties into DCS Moines River.

E. Rock River at Luvernc, Minnesota. A tributary of Sioux River. Analysis by Noycs, Geology of 

Minnesota, vol. 1, 1884, p. 550.

F. Minnesota River at Shakopce, Minnesota. Mean analysis of 30 composite samples taken between 

September 24, 1906, and October 1, 1907. W. M. Barr, H. S. Spaulding, W. Van Winkle, R. B. Dole, 

C. Palmer, and W. D. Collins, analysts. Alkali determinations as corrected by Palmer.

Q. Chippewa River near Eau Claire, Wisconsin. Mean of 35 composites, September 14, 1906, to September 12,1907. Barr, Spaulding, and Van Winkle, analysts.

H. Wisconsin River near Portage, Wisconsin. Mean of 24 composites, September 11,1906, to May 17, 

1907. Same analysts as under G.

Analyses F, G, H are recalculated from the figures given by Dole in Water-Supply Paper 236.

rr>

S04 ................. ci..................

N03 ..... ............

Ca...................

Mg............. ......

Na . ...........

K. .................

Si02 .................

Fea08 .......... ......

A1 O

Salinity, parts per

A

58.81

.72

25.52

7.23

1.03

2.32 

4.37

100. 00 

110

B .

59.03

.88

.59

15.25

10.71

6.68

2.24 

2.97

1.65

100. 00 

144

C

20. 13

34.36

1.65

8.00

8.61

6.69

1.01 

19.26

.29

100. 00

554

D

42.65

18.62

1.14

1.39

20.71

8.00

2.94

1.32 

2.61

} .62

'

100. 00

272

E

47.94

8.64

.44

20.51

7.43

3.31

.51

7.65

3.21

.36

100. 00 

275

F

31.59

31.26

1.02

.43

17.81

7.61

4 12

1.15 

4.09

.02

100. 00 

480

G

30.49

18.09

1.42

.78

16.80

6.07

UO. 46

15. 50

qo

100. 00 

90

H

31.43

18.74

2.31

.99

15. 44

7.50

| 8.93 

14.33

.33

100. 00 

Q8

1 For analyses of several other Minnesota waters, see Water-Supply Paper U. S. Geol. Survey No. 193, 

1907, p. 133. Analyses of water from a number of Wisconsin lakes arc given by E. A. Birge and C. Juday 

in Bull. Wisconsin Gcol. and Nat. Hist. Survey No. 22,1911, pp. 170,171.
78 DATA OF GEOCHEMISTRY.

The following table gives analyses of waters tributary to the Mississippi in Illinois and Iowa: 1

. Analyses of tributaries in Illinois and loiva.

A. Rock River near Sterling, Illinois. Mean analysis of 36 composite samples taken between August 1,

1906. and July 31, 1907. AV. D. Collins, analyst. Collins also gives a similar annual average for the 

river at Rockford.

B. Illinois River near Kampsville, Illinois. Mean of 36 composites, August 1, 1906, to July 31, 1907. 

Collins, analyst. Ho also gives similar analyses for the river near Lasalle and Peoria.

C. Kaskaskia River at Carlyle, Illinois. Mean of 34 composites, August 1,1906, to July 31,1907. Collins, 

analyst. A similar average is given for the river near Shelbyville.

D. Cedar River near Cedar Rapids, Iowa. Mean of 37 composites, September 6, 1906, to September 17,

1907. W. M. Barr, H. S. Spaulding, and W. Van Winkle, analysts.

E. Iowa River at Iowa City, Iowa. Mean of 36'Composites, September 6, 1906, to September 16, 1907. 

Same analysts as under D.

F. Des Moincs River at Keosauqua, Iowa. Mean of 36 composites, September 10, 1906, to September 9, 

1907. Same analysts as under D.

Analyses A, B, and C are recalculated from the figures given by Collins in Water-Supply Taper 239; 

the others arc from Dole, Water-Supply Paper 236.

Collins also gives annual averages for the composition of the waters of Kankakec, Fox, Vermilion, 

Sangamon, Muddy, Embarrass, Little Wabash, and Cache rivers. In all, 19 rivers were studied, including 

the Mississippi.

C08 .... ........................

S04 .... .......................

Cl.............. ..............

N03 ................ ...........

Ca...........................

Mg.. ...........................

Na................. ...........

K... ......... ................

Si02 .... .....................

Fe203 ........................ & o

Salinity, parts per million. ....

A

48. 56

9.34

2.06

1.42

18.30

10.09

1 4.48

5.60

.15

100. 00 

267

 B

38.42

16.30

5.82

1.67

18.24

7.76

| 6.98

4.65

.16

100. 00 

267

C

42.13

13.64

2.77

1.92

18.86

8.02

1 5.62

6.84

.20

100. 00

248

D

44.80

13.08

1.48

1.35

20.91

6.97

] 5.23

6.10

.08

100. 00 

228

E

42.17

14.70

1.47

1.15

20.00

6.94

1 5.67

7.76

.14

100. 00

247

F

34.96

23.37

1.58

1 09

19.09

6.91

1 5.59

7.24

1.7

100. 00 

312

Iii the following table I .give analyses of waters which reach the 

Mississippi from the eastward by way of the Ohio. 2 For the Ohio 

itself I have found no satisfactory data.

1 In Iowa Geol. Survey, Ann. Rcpt. 26, for 1915, p. 29, G. A. Gabriel gives analyses of water from Raccoon 

Des Moincs, Cedar, and Iowa rivers.

2 An analysis of Monongahela water by C. D. Howard and one of water from the Cumberland by N. 

Lupton are given in the first edition of this book (Bulletin 330).
LAKES AND RIVERS. 79

Analyses of ivaters tributary to Ohio River.

A. Allegheny River at Kittanning, Pennsylvania. Mean analysis of 36 composite samples takcn-bctween 

September 13, 1906, and September 10, 1907. R. B. Dole, M. G. Roberts, and C. Palmer, analysts.

B. Monongahcla River at Elizabeth, Pennsylvania. Mean of 37 composites, August 25,1906, to September 2,1907. Same analysts as under A. Dole also gives an annual average for the composition of Youghioghcny \vater.

C. Muskingurn River at Zanesville, Ohio. Mean of 27 composites, September 3,1906, to September 13, 

1907. Same analysts as under A.

D. Miami River at Dayton, Ohio. Mean of 34 composites, September 10, 1906, to September 17, 1907. 

Dole, Roberts, Palmer, and Collins, analysts.

E. East Fork of White River near Azalia, Indiana. Mean of 37 composites, September 12, 1906, to 

October 3,1907. Barr, Spaulding, Van Winkle, Dole, Palmer, and Collins, analysts.

F. West Fork of White River near Indianapolis, Indiana. Mean of 35 composites, September 8, 190G, 

to September 12,1907. Barr, Spaulding, and Van Winkle, analysts.

G. Wabash River at Vinccnnes, Indiana. Mean of 31 composites, September 9,1906, to September 1, 

1607. Same analysts as under F.

H. Kentucky River at Frankfort, Kentucky. Mean of 36 composites, August 28,1906, to September 4,

1907. Same analysts as under D. 

1. Cumberland River at Kuttawa, Kentucky. Mean of 34 composites, January 11,1907, to January 11,

1908. Evans, Dole, Palmer, and Collins, analysts. Another average is given for the water near Nashville, 

Tennessee.

J. Tennessee River near Gilbertsville, Kentucky. Mean of 33 composites, October 24,1906; to October 

24,190S. Van Winkle, Dole, Palmer, and Collins, analysts. Another average is given for the water at 

Knoxvillc, Tennessee.

All tho analyses in this series are recalculated from the figures given by Dole in Water-Supply Paper 

236, as corrected by the later alkali determinations of Palmer.

co3 .... ........... ...................

so4 .. ..................................

01..... ...............................

NO

Ca................. ....................

Mg...................................

Na............ ........................

K.... ................................

SiO

Fe203 . .................................

oo

S04 ......... ..........................

Cl............ ........................

NO.............. ......................

Ca................. ....................

Mg... .................................

Na............... .....................

K...... ..............................

Si02 .. .................................

Fe2O...... .....:.......................

Salinity, parts per million ...............

A

21.51

19.55

16.10

.82

16.10

3.46

11.04

2.09

9.09

.24

100. 00

87

F

31.76

12.88

17.32

1.36

16.44

6.44

1 10.66

3.10

.04

100. 00 

450

B

11.47

42.52

' 4.12

2.32

15.47

2.84

8.12

1.42

10.82

.90

100.00 

81

G

34.09

16.57

10.84

1.93

18.37

6.63

1 7.56

3.92

.09

100. 00 

336

C

24.71

18.36

17.07

.69

18.36

4.06

9.39

1.28

5.98

.10

100. 00

244

 H

38.51

8.32

2.01

2.51

21.06

3.71

5.82

1.41

16.05

.60

100. 00 

104

D

43.64

13.88

1.42

2.98

20.46

8.33

2.49

.83

5.89

.08

100. 00

289

I

40.57

7.85

2.43

1.46

22.67

3.48

4.29

2.34

14.59

.32

100. 00 

124

E

47.85

10.58

1.10

.197

21. 51

8.11

2.75

.77

^ 9Q

.07

100. 00 

279

J

34.57

10. 74

2.93

1.17

18.56

4.00

5.08

2.83

19.54

.58

100. 00 

101
80 DATA OF GEOCHEMISTRY.

For the largest tributary of the Mississippi the Missoiri several 

analyses are available. They are given in the following table, together 

with analyses of its affluents. 1

Analyses of water from Missouri River and tributaries.

A. Missouri River near Florence, Nebraska. Mean analysis of 3.6 composite samples taken between 

October 1,1906, and October 14,1907. Barr, Spaulding, Van Winkle, Dole, Palmer, and Collins, analysts.

B. Missouri River near Kansas City, Missouri. Mean of 38 composites, October 4,1906, to October 21, 

1907. Same analysts as under A.

C. Missouri River near Ruegg, Missouri. Mean of 36 composites, September 24,1906, to October 6,1907. 

Same analysts as under A.

D. North Platte River at North Platte, Nebraska. Mean of 29 composites, September 10,1906, to June 

30,1907. Barr, Spaulding, and Van Winkle, analysts.

E. Platte River at Fremont, Nebraska. Mean of 33 composites, October 10, 1906, to November 2,1907. 

Barr, Van Winkle, Dole, Palmer, and Collins, analysts. Another series of analyses of the water at 

Columbus is also given. An analysis of the Platte at Greeley, Colorado, is given on p. 66, ante, together 

with some of its tributary, Cache la Poudre River.

F. Laramie River 20 miles above Laramie, Wyoming. Average of three analyses by E. E. Slosson, 

Bull. Wyoming Exper. Sta. No. 24,1895.

G. Laramie River 50 miles below Laramie. Analysis by E. E. Slosson, loc. cit. Slosson also gives 

analyses of Popo Agie and Little Goose creeks. Another analysis of the Laramie is printed in Fifth Rept. 

Bur. Soils, U. S. Dcpt. Agr., 1903.

H. Yellowstone Lake. Analysis by J. E. Whitfleld, Bull. U. S. Geol. Survey No. 47,1888. This bulletin 

also gives analyses of Firebole and Gardiner rivers.

Analyses A to E are recalculated from Dole's Water-Supply Paper 236, with potassium determinations 

communicated by Palmer.

rr»

so4 ................. ci.................. "NTH

Ca.. ....... ..........

Mg.. ...............

Na.. ..................

K. .................

NH4 ....... ..........

SiOo.................

AI n

Fe203 . ...............

Salinity, parts per

A

22.42

37.69

1.99

.40

14.58

4.48

9.64

1.70

6.95

.15

100. 00

454

B

24.23

32.74

3:15

.54

15.04

4.37

9.22

1.50

8 Q7

.24

100. 00

 426

c

25.63

30.44

3.52

.85

15.22

4.68

9.07

1 QO

8

AQ

' 90

100. 00 

346

D

24.13

32.77

Q -1C

.53

15.05

4.37

UO. 68

'

8 no

34

100. 00 

426

E

29.43

22.18

2.18

.33

15.80

3.67

8.06

2.42

15.80

no

100. 00 

302

F

27.35

11.16

3.11

13.75

2.45

7.34

.85

Q-l 70

} 2.26 '

100. 00

919

G

19.59

37.48

6.32

15.07

5.10

8.82

1 Qft

4.54

} 1.12 '

100. 00 

429

H

90 Q3

7 19

7.96

7 9Q

.25

13.22

q on

.34

35.51

3

oq

100. 00 

118

In all but three of these waters sulphates predominate over carbonates, and calcium is less conspicuous than in the anatyses preceding 

this group. The high silica of the Yellowstone Lake and the upper 

Laramie is also noticeable.

For one other tributary of the Missouri a particularly interesting 

group of analyses is at hand. Kansas or Kaw River, with its chief 

affluents, has been studied by E. H. S. Bailey and his assistants,2

1 Two analyses of water from the Missouri, not used here, are given in the first edition of this book. 

Another analysis by F. W. Traphagen is cited inE. W. Hilgard's Soils, p. 23, but the point of collection 

is not named.

2 U. S. Geol. Survey Water-Supply Paper No. 273,1911. Some earlier analyses by Bailey and Franklin 

are cited in the previous editions of this work.
LAKES AND RIVEKS. 81

whose data, reduced as usual, are given in the next table. The localiJ ties mentioned are all in the State of Kansas, and the arrangement of 

the streams is from the west, eastward.

Analyses of water from Kansas River and its tributaries. 

.(

A. Smoky Hill River at Lindsborg. Mean of 2S analyses of composite samples of water taken between 

November 27,1906, and November 29,1907. F. W. Bushong and A. J. Wcith, analysts.

B. Saline River at Sylvan Grove. Mean of 34 composite samples taken between November 27,1900 

and November 29,1907. Analyses by Bushong.

C. Solomon River at Bcloit. Mean of 32 composite samples taken between December 1, 1906, and December 5,1907. Bushong and Wcith, analysts.

D. Republican River at Junction. Mean of 25 composite samples taken between November 26, 1906, 

and September 10,1907. Bushong and Weith, analysts'.

E. Big Blue River at Manhattan. Mean of 34 composite samples taken between December 19,1906, and 

December 20,1907. Bushong and Wcith, analysts.

,.' F. Delaware River at Perry and Valley Falls. Mean of 27 composite samples taken between January 

4 and November 29,1907. Bushong and Weith, analysts.

G. Kansas River at Holliday. Mean of 72 composite samples taken between December 29, 1906, and 

December 31, 1908. Two years' average. Analyses by F. W. Bushong, A. J. Wcith, and W. L. Sippy. 

Analyses of several other tributaries of the Kansas are also given in the paper.

PA

so4 .........................

01..........................

N08 .. ......................

Ca. ........................

Mg. ........................

Na,K. .....................

Si02 .. .....................

FeA. .....................

Salinity, parts per million. . .

A

14.40

26.87

21. 61

.21

12.93

2.41

18.26

3.18

.13

100. 00

882

B

6.02

18.26

38.57

.03

5.03

1.98

28.97

1.07

.07

100. 00

2,624

C

26.17

19.50

12.09

.54

16.61

2.89

15.52

6.32

.36

100. 00

554

D

34.36

12.56

7. .11

.71

16.35

3.32

13.50

11.38

.71

100. 00

422

E

35.53

12.32

5.89

.64

18.74

3.92

12.32

9.52

1.12

100. 00

357

F

39.47

12.17

3.85

1.07

20.78

4.75

9.79

6.82

1.30

100. 00

337

G

31.78

15.14

10.18

.57

18.12

3.98

12. 66

7 1Q

.38

100. 00

403

The two westernmost of these streams flow from a relatively arid 

region and are characterized by high salinity. They are peculiarly 

poor in carbonates but rich in sodium and chlorine, conditions which 

may be correlated with the great abundance of salt in Kansas. In 

Solomon River carbonates begin to predominate; and in the easternmost rivers of the group there is a close approximation in 

chemical character to some streams of the Atlantic slope. Kansas 

River itself represents a blending of all the waters which flow into it. 1

Two analyses of water from Arkansas River have already been 

cited, and need not be repeated here. Other analyses of this river 

and its tributaries, together with Osage and Red rivers will end 

this summary of the Mississippi basin. 2

i Partial analyses of about 50 streams in Oklahoma may be found in Water-Supply Paper U. S. Geol. 

Survey No. 148,1905. A paper by J. H. Norton on the drainage of Richland Creek, Arkansas, appeared 

in Jour. Am. Chem. Soc,, vol. 30,1908, p. 1186. An analysis of water from Wakarusa River is cited in tho 

second edition of this work.

8 Two analyses by R. N. Brackett of water from the Arkansas are given in Ann. Rept. Arkansas Geol 

Survey, 1891, vol. 2, pp. 159,160.

113750° 19 Bull. 695 6
82 DATA OF GEOCHEMISTRY.

Analyses of water, from the Arkansas and other rivers.

A. Osage River, at Boieourt, Kansas. Mean of 33 analyses of composite samples of water taken, between 

November 29,1906, and November 30,1007. F. W. Bushong and A. J. Weith, analysts. This stream is a 

tributary of the Missouri.

B. Arkansas River at Deerfield, Kansas. Mean of 26 composite samples taken between December 11, 

1906, and December 2,1907. Bushong and Weith, analysts.

C. Arkansas River near Great Bend, Kansas. Mean of 33 composite samples taken between November 

26,1906, and December 7,1907. Bushong and Weith, analysts.

D. Arkansas River at Arkansas City, Kansas. Mean of 27 composite samples taken between December 

7,1906, and December 10,1907. Bushong and Weith, analysts.

E. Arkansas River at Little Rock, Arkansas. Mean of 22 composite samples taken between November 

f, 1906, and October 24,1907. Barr, Spaulding, Van Winkle, Dole, Palmer, and Collins, analysts. Recalculated from Water-Supply Paper No. 236.

F. Cimarron River at Englewqod, Kansas. Mean of 30 composite samples taken between November 

30,1906, and November 30,1907. Bushong and Weith, analysts. A tributary of the Arkansas.

G. Neosho River at Emporia, Kansas. Mean of 35 composite samples taken between December 5,1906, 

and December 5,1907. Bushong and Weith, analysts. A tributary of the Arkansas. An earlier, single 

analysis of Neosho water by C. F. Gustavsen appears in Kansas Univ. Sci. Bull., vol. 2, p. 243,1903.

H. Red River near Shreveport, Louisiana. Mean of 34 composite samples taken between March 19, 

1906, and March 19,1908. Dole, Palmer, Collins,and Evans,analysts. Recalculated from Water-Supply 

Paper 236, with later alkali determinations by Palmer. All these analyses except E and H are taken from 

Water-Supply Paper No. 273. In this paper there are also analyses of the Marmaton, Walnut, Medicine 

Lodge, Chikaskia, Verdigris, Fall, Cottonwood, and Spring rivers, with some minor streams, all in Kansas.

co8 . .... ..........

so4 ..... ............ ci.....................

NO

Ca...................

Mg........... ........

Na..................

K.... ................

Si02 ....... ..........

Fea03 --------------

Salinity, parts per

A

37.26

12.31

3 41

1.20

22.90

4.10

1 9.56

8.20

1.06

100. 00 

293

B

7.55

54.70

4.77

.21

12.31

4.11

114. 24

1.92

.19

100.00 

1,510

C

9.95

47. 19

8.72

.17

13.13

3.52

114. 71

2.46

.15

100. 00 

1,136

D

12.33

19.18

29.03

.18

9.44

2.39

1 24. 15

3.08

.22

100. 00 

1,006

E

all. 89

15.19

33.17

.33

8.99

2.13.

1 23. 53

4.57

.20

100. 00 

630

F

11.42

11. 87

37.65

.13

6.93

2.57

1 26. 91

2.87

.15

100. 00 

1,323

G

39.02

10.61

2.25

1.09

20.60

4.05

1 7.80

13. 77

.81

100. 00 

320

II

13.01

25.65

22.16

.07

13.56

3.12

15.74

.91

5.49

.29

100. 00 

561

SOUTHWESTERN RIVERS.

A few of the rivers of the southwestern United States have been 

studied with much. care. The following analyses represent this 

group: 1

i An analysis of Rio Grande water by 0. Loew is given in Rept. U. S. Goog. Surveys W. 100th Mer., 

vol. 3,1875, p. 576. In the annual report of the same Survey for 1876 Loew gives an aualysis'of water from 

Virgin River, a tributary of the Colorado. For two analyses of the Pecos see B. S. Tilson, Bull. Geol. 

Survey Texas No. 2,1910. Analyses of Rio Grande water by Fraps and Tilson are cited in Circular 103, 

Office Exper. Sta., U. S. Dept. Agr., 1911. Six more analyses of water taken near the headwaters of the 

Rio Grande in the San Luis Valley, Colorado, are published by W. P. Headden in Bull. 230 of the Agricultural Experiment Station of the Colorado Agricultural College, 1917.
LAKES AND RIVERS. 83

Analyses ofiuaterfrom southwestern rivers.

A. Brazos River at Waco, Texas. Mean analysis of 30 composite samples taken between December 

14, 1936, and November 19,1907. Barr, Spauldmg, Van Winkle, Dole, Palmer, and Collins, analysts. 

Recalculated from Water-Supply Paper 236, with later allrali determinations by Palmer.

B. Colorado River of Texas, at Austin. Moan of 36 composites, August 1,1905, to July 27,1906. W. H. 

Heiloman, analyst, Water-Supply Paper 236.

C. Rio Grande at Laredo, Texas. Mean of 37 composites, August 1,1905, to August 2,190G. Heileman, 

analyst, loc. cit.

D. Rio Grando at Mesilla, New Mexico. Average composition for an entire year, June, 1893, to June, 

1894. Analyses by Arthur Goss, Bull. New Mexico Agr. Exper. Sta. No. 34,1900. This bulletin also 

contains analyses of water from Animas River, Santa Fo River, and Rio Bonito.

E. Pecos River, New Mexico. Average of six samples analyzed by Goss, loc. cit.

T. Colorado River at Yuma, Arizona. Average of seven composite samples, covering collections made 

between January 10,1900, and January 24,1901. Analyzed by R. II. Forbos and W. W. Skinner, Bull. 

Univ. Arizona Agr. Exper. Sta. No. 44,1902. The average composition of the water dm-ing a year.

G. Gila River at head of Florence canal, below The Buttes, Arizona. Average of four analyses by 

Forbes and Skinner representing 21 weekly composites. Samples taken between November 28,1899, 

and November 5,1900.

TJ. Salt River at Mesa, Arizona. Average of six analyses covering 40 weekly composites of water 

taken between August 1,1899, and August 4,1900. Analyses by Forbes and Skinner, loc. cit. Salt River 

and the Gila are tributaries of the Colorado. Forbes and Skinner report their silica as the silicate radicle 

Si03 . This is reduced to Si02 in the table.

C03 .... ..............

S04 . ................

Cl..................

NOIN u3 . ................ 

Ca...................

Mg...................

Na..................

K.... ........ ........

SiOa ....... ..........

AlA.. ..............

Fe2 03 ----------------

Salinity, parts per

A

7.09

25. 4.9

30.87

.20

11.06

1.74

20.83

.67

2.01

.04

100. 00 

1,136

B

28.60

12.48

17. 52

15.45

5.14

13.07

1.50

5.32

} .92 '

100. 00

321

0

11. 55

30.10

21.65

13. 73

3.03

14.78

.85

3.83

[.«

100. 00

791

D

17.28

31. 33

13.55

14.78

2.05

14.43

1.95

1 4.63

'

100. 00 

399

E

1.54

43.73

22.56

13.43

3.62

14.02

.77

.33

100. 00

2,384

F

13.02

28.61

19.92

10.35

3.14

19.75

2.17

3.04

100. 00 

702

G

12.10

16.07

29.78

8.03

2.52

24.53

2.31

4.66

100. 00 

1, 023

II

9.61

8.29

41.56

7. is

2.69

26.38

1.38

2.94

100. 00 

1, 234

These waters are characterized, as is evident on inspection of the 

table, by high salinity, the predominance of alkaline sulphates and 

chlorides, and a deficiency of carbonates and of lime. From figures 

given by Forbes I have computed that the Colorado carries to the 

Gulf of California annually, in solution, 13,416,400 metric tons of 

salts, or about 59.6 metric tons from each square mile of its basin.

RIVERS OF CALIFORNIA.

For the river waters of California the data are now very abundant, 

but only a small part of them, can be utilized here. A number of 

individual analyses are to be found in the former editions of this 

book;1 the following table is recalculated from the figures reported

1 Clear Lake, analysis by T. Price, cited in Water-Supply Paper U. S. Geol. Survey No. 45, 1901. 

Feather River, by E. W. Hiigard, Rept. Agr. Exper. Sta., Univ. California, 1898-1901. San Lorenzo 

River, by A. Seidell, Field Operations Bur. Soils, U. S. Dept. Agr., 1901. Santa Clara River, by B. E. 

Brown, same reference as the preceding. Santa Ynez River and three of its tributaries, by J. A. Dodge, 

Water-Supply Paper U. S. Geol. Survey No. 116,1904. Other analyses, by H. G. Kelsey, appear in 

University of California, Rept. Coll. Agric., 1882.
DATA OP GEOCHEMISTRY.

by W. Van Winkle and F. M. Eaton in Water-Supply Paper 237, 

1910. In that paper the average composition of a river water is 

ascertained by many analyses of composite samples, representing 

daily collections, as was done in the investigations under Dole and 

Collins which have already been freely cited. The composition of 

each water is thus determined for a sufficiently long time to give 

the figures real significance in geochemical research. Van Winkle 

and Eaton, by this general method, studied 37 rivers of California.

Analyses of water from rivers of California.

A. Russian River near Ukiah. Mean analysis of 37 composite samples taken between December 31,

1907. and December 31,1908. 

B. Sacramento River above Sacramento. Mean of two series of analyses covering the years 1906 and

1908. Potassium was separately determined during the first half of 1906, and the same is true of total 

Fe203+Al208. In recalculating, these determinations are assumed to be fair averages. Van Winkle 

and Eaton also give annual averages for Feather, Yuba, and American rivers and Cache Creek, all tributaries of the Sacramento.

C. San Joaquin River at Lathrop. Mean of two series, 1906 and 1908, recalculated as in the case of the 

Sacramento. Similar averages for one year or less are given for the tributary rivers Mokelumne, Stanislaus, Tuolumne, Merced, and Kern.

D. Salinas River at Paso Robles. Mean of 30 composites taken in 1908. From about July 18 to October 1 the river bed was dry. Data are given for several tributaries of the Salinas.

E. Santa Maria River 25 miles above Santa Maria. Mean of 36 composites covering the year 1906. K 

and total R2Os were only determined during the first half year.

F. Santa Ynez River at Santa Barbara. Mean of 33 composites covering the year 1906. K and R208 

determined during the first half year only.

G. San Gabriel River near Rivera. Mean of 37 composites covering the year 19&8. Another average 

is given for the river at Azusa.

H. Santa Ana River above Mentone. Mean of two series, 1906 and 1908. K and R2 08 determined 

during the first half of 1906. Another annual average is given for the river near Corona. ..

C08 .. ................

S04 .................

01..................

NO...... ............

Ca......... ..........

Mg........ ...........

Na.... ..............

K. ...................

Si08 .. ...............

AlsOg........ ........

FeA...... ..........

Salinity, parts per

A

39.07

10.81

4.70

.77

14.61

7.62

no. 17

12.07

.18

100. 00 

145

B.

30.14

12.21

5.79

.48

11.45

5.59

9.78

1.68

19.12

3.35

.41

100. 00

118.5

c

18.43

17.41

20.62

.54

10.13

4.82

15.81

1.08

9.38

1.56

.22

100. 00 

183

D

30.66

21.35

8.59

.16

13.21

6.17

112. 99

6.82

.05

100. 00

448

E

5.82

58.35

4.89

14.07

6.19

8.94

.37

1.12

.24

.01

100. 00 

2,412

F

19.33

42.58

3.71

14.98

6.68

8.10

.51

3.56

.53

.02

100. 00

714

G

40.54

12.62

3.22

.73

21.04

4.59

1 8.41

8.79

.06

100. 00 

246

H

35.78

11.34

3.70

.50

17.02

4.00

10.67

1.33

13.68

1.86

.12

100.00 

152

THE COLUMBIA RIVER BASIN.

The waters of Oregon and Washington have been studied with 

much thoroughness by W. Van Winkle 1 and a selection from among 

his abundant data is given in the following tables. The Columbia 

and its tributaries come first.

Water-Supply Papers U. S. Geol. Survey Nos. 339,363,1914.
LAKES AND RIVERS. 85

Analyses of water from Columbia and Snake rivers.

A. Columbia River at Northport, Washington. Mean of 37 analyses of composite samples of water 

taken between February 1,1910, and January 31,1911.

B. Columbia River at Pasco, Washington. Mean of 37 composite samples taken between Februaiy 1, 

1910, and January 31,1911.

C. Columbia River at Cascade Locks. Mean of 30 composite samples taken between March 13 and 

December 31, 1910, and 37 composite samples taken between August 11, 1911, and August 14, 1912. 

Nearly two years' average.

D. Snake River near Weiser, Idaho. Mean of 37 composite samples taken between August 11,1911, 

and August 14,1912.

E. Snake River at Burbank, Washington. Mean of 33 composite samples taken between March 13, 

1910, and January 31,1911.

co8 ........... ........................

S04 .................................. ci.........................:...........

NQ8 ............ ......................

Ca.. ..................................

Mg............ ........................

Na............................ '.......

K....... ..............................

Si02 .. ................................

RaCv..... .............................

Salinity, parts per million.... ..........

A

42.38

14.12

.71

.27

21.19

5.53

} 5.53

10.24

03

100. 00 

85

B

42.81

13. 08

.84

.16

21.40

5.35

1 7.14

9.16

.06

100. 00

84

c

36.15

13.52

2.82

.49

17.87

4.38

8.12

1.95

14.62

.08

100. 00 

92.4

D

31. 02

16.45

7.99

.28

15.51

4.52

10.34

1.64

12.22

.03

100. 00 

213

E

31.95

16.37

6.31

.41

14.81

4!37

1 10.91

14.81

.06

100. 00 

128

Analyses of water from tributaries to the Columbia.

F. Spokane River at Spokane, Washington. Mean of 35 composite samples taken between February 1, 

1910, and January 31, 1911. 

G. Yakima River at Prosser, Washington. Mean of 37 composite samples taken between February 1,

1910. and January 31, 1911. 

H. Owyheo River near Owyhee, Oregon. Mean of 37 composite samples-taken between August 11,

1911. and August 14,1912.

I. Grand Rondo River at Elgin, Oregon. Mean of 37 composite samples taken between August 11, 

1911, and August 14, 1912.

J. Uraatilla River near Umatilla, Oregon. Mean of 36 composite samples taken between August 11, 

1911, and August 14,1912. Analyses are given by Van Winkle for samples collected at two other points 

also.

K. John Day River at McDonald, Oregon. Mean of 37 composite samples taken between Augustll, 

1911, and August 14,1912. Analyses are given for the water at Day ville also.

L. Deschutes River at Moody, Oregon. Mean of 34 composite samples taken between August 21,1911, 

and July 25,1912. -Analyses are given for the water at Bend also.

M. Willamette River at Salem, Oregon. Mean of 37 composite samples taken between August 11,1911^ 

and August 14, 1912.

Van Winkle gives analyses, most of them annual averages, for 13 other rivers of the Columbia basin.

°

co8 ...... ............

so4 .................

01........ ............

NO

Ca..... ..............

Mg....... ............

Na.... ...............

K... .................

SiOo.. ...............

Fe20a .. ..............

Salinity, parts per 

million. ...........

F

35.94

14. 43

.94

.36

17.19

5.62

1 8.28

17.19

.05

100. 00 

64

G

82.30

17.39

4.30

.28

13.25

5.05

111. 59

15.73

.11

100. 00 

121

H

31.24

15.85

5.89

.29

11.78

2.90

15.85

2.08

14.04

.08

100. 00 

221

I

30.03

6.12

1.85

.86

11.55

3.23

9.00

2.31

34.64

.41

100. 00 

87

J

31.49

12.71

5.18

.62

12.71

3.65

12.15

2.65

18.78

.06

100. 00 

181

K

39.79

8.51

 1.92

.78

14.18

5.39

9.22

1.70

18.44

.07

100. 00 

141

L

31.81

5.68

2.38

.75

9.66

3.06

12.50

2.28

31.81

.07

100. 00 

88

M

28.32

8.19

4.21

.79

11.73

3.09

8.41

1.77

33.18

.31

100. 00 

45
86 DATA OF GEOCHEMISTRY.

According to Van Winkle the Columbia carried in solution past 

Cascade Locks, in 1910, 21,638,000 short tons of dissolved matter, 

and in 1911-12, 17,000,000 tons. This, for a drainage area of 239,600 

square miles, is equivalent to 90.3 and 71 tons per square mile; an 

average of 80.6 or 73 metric tons.1 Similar estimates are given for 

each of the tributaries.

OTHER NORTHWESTERN RIVERS.

In the next table analyses are given of waters from Oregon arid 

Washington. Except when otherwise stated, the analyses are by W. 

Van Winkle,2 and represent annual averages.

Analyses of norllnvestern vjaters.

A. Skagit River at Sedro Woolley, Washington. Mean of 37 analyses of composite samples of water 

taken between February 1,1910, and January 31,1911.

B. Chehalis River at Centralia, Washington. Mean of 35 composite samples taken between February 

1,1910, and January 31,1911.

C. Rogue River near Tolo, Oregon. Mean of 34 composite samples taken between September 10,1911, 

and August 14, 1912.

D. Umpqua River near Elkton, Oregon. Mean of 22 composite samples taken between August 1,1911, 

and August 15, 1912.

E. Goose Lake, Oregon. Single analysis by Van Winkle.

F. Lost River, Klamath County, Oregon. Single analysis by A. L. Knisely. Ann. Eept.Irr. and Drainage Investigation, U. S. Dept. Agr., 1904, p. 264.

G. Crater Lake, Oregon. Single analysis by N. M. Finkbincr. Cited by Van Winkle in Water-Supply 

Paper 363, p. 43. Included here on account of its analogy to the river waters of Oregon, although it properly belongs in the chapter on closed basins.3

co3 .... ...... ................

S04.. .......................

Cl..... .....................

NO

PO

Ca........ ...................

Mg... ......................

Na. ............ .

K........ ..................

Si02 .... .....................

Fe203 - .....................

Salinity, parts per million..

A

30.78

17.71

1.95

.52

17.06

3.67

1 7.78

20.30

.23

100. 00 

46

B

26.06

10.93

8.88

.18

12.12

3.24

111. 10

27.31

.18

100. 00 

59

C

28.83

6.32

2.16

.40

11.11

2.62

9.41

2.00

37.00

.15

100. 00 

65

D

28.66

8.43

4.85

.49

12.80

3.58

9.24

2.59

29.14

.22

100. 00 

62

E

34.30

4.92

10.92

.16

.12

1.96

.22

38.23

3.71

5.46

Trace.

100. 00 

916

F

52.64

3.37

1.46

14.12

12.06

2.78

10.78

10. 42

a2.37

100. 00 

220

G

20.62

13.75

13.75

.47

.01

8.88

3.50

13. 75

2.75

22. 50

.02

100. 00 

o 80

1 For earlier single analyses of the Columbia, Snake, Willamette, and Powder rivers, see the second 

edition of this Work, p. 78. Powder River is a tributary of the Snake.

2 See Water-Supply Papers U. S. Geol. Survey Nos. 339 and 363,1914.

3 Van Winkle also gives analyses of waters from Wood Creek, Cedar, and Green rivers in Washington, 

and of Link, Wood, and Siletz rivers in Oregon. For an earlier analysis of water from Cedar River, see 

H. G. Knight, Washington Geol. Survey, vol. 1, p. 285,1901. Analyses of water from Lower Klamath Lake 

arc given in U. S. Dept. Agr. Field Oper. Bur. Soils, 1908, p. 1412.

a Includes Al2 0s.
LAKES AND RIVERS. 87 

RIVERS OF ALASKA.

R. B. Dole and A: A. Chambers 1 give a goodly number of analyses 

of waters from the rivers of Alaska. From these the following analyses are selecte'd and reduced to the standard form which has been 

adopted in this work. With them one other analysis, by G. Steiger,

is included.

Analyses of luaters from Alaska.

A. Yukon River at Eagle. Analysis by G. Steiger, reported by F. W. Clarice, Jour. Am. Chem. Goo., 

vol. 27, p. Ill, 1905.

B. Yukon River. Mean of four analyses of samples taken at points between Whitehorso and Selwyn.

C. Yukon River. Mean of thirteen analyses of samples taken between Selwyn and the mouth of the 

river. Analyses B and C by Dole and Chambers.

D. Tanana River, 15 miles below Chena.

E. Tanana River, 5 miles aboveits mouth. Analyses D and E by S. C. Dinsmorc. Analyses of several 

tributaries of the Tanana are also given.

F. Lowo River near Valdcz. Analyst, S. C. Dinsmore.

G. Copper River at Flag Point Bridge. Analyst, A. A. Chambers.

II. Stikine River about 15 miles above WrangeU. Analyst, S. C. Din?more. Six analyses of water from 

the Seward Peninsula are also reported, all by Dinsmorc.

cos .. ..............

S04 . ................

01. .................

N03 ..... ............

Ca...................

Mg.. ...............

Na.... ..............

K. .................

Si08 .. ...............

Fea08 ----- - - - -

Ala08 .-----. -.-- 

Salinity parts per

A

46. 16

10. 75

.41

22.21

4.71

6.14

Trace.

7.78

1.84

100. 00 

98

B

41.93

10.37

Trace.

23.25

4.39

1 5.61

14.39

.06

100. 00

71

C

44.03

13.99

.01

24.38

5.23

1 4, 71

7.52

.13

100. 00 

122

D

43.73

10.78

2.50

.66

25.77

4.08

1 3.33

9.15

Trace.

100. 00 

]23

V.

40.44

16.30

1.24

.15

23.29

3.95

| 5.98

8.54

.11

100. 00 

130

F

37.85

12.79

3.91

2.61

14.35

3.91

U4. 35

9.15

1.08

100. 00

87

G

40.68

13.53

1.20

.38

24.06

5.49

1 8.27

6.01

.38

100. 00 

146

H

34.87

16.87

1.69

Trace.

.23. 62

4.05

1 1.13

16.88

.90

100. 00 

81

Dole and Chambers estimate that the Yukon carries annually into 

Bering Sea 98,000,000 short tons of suspended matter and 24,000,000 

tons of matter in solution. The area of the drainage basin is estimated 

at 320,000 square miles. Hence, froni each square mile 307 tons of 

solids are carried away, together with 7.5 tons (equal to 68 metric 

tons) of dissolved matter. The waters are all carbonate waters, 

with very small quantities of chlorides. The Yukon especially contains surprisingly little chlorine. The sulphates are about normal.

THE SASKATCHEWAN SYSTEM.

This complex river system comprises a number of important 

branches, which finally unite in Nelson River and empty into Hudson Bay. The following analyses represent waters from this great 

drainage basin:

1 Water-Supply Paper U. S. Gcol. Survey No. 418,1917, pp. 99-109.
88 DATA OF GEOCHEMISTRY.

Analyses of waters from Saskatchewan system.

A, Bed River of the North at Fergus Palls, Minnesota. Analysis by W. A. Noyes, Eleventh Ann. Rept. 

Minnesota Gcol. Nat. Hist. Survey, 1884, p. 173.

B. Red River of the North at St. Vincent, Minnesota, near the Canadian boundary. Analysis by W. A. 

Noyes, op. cit., p. 172.

C. Red River of the North below the Assiniboine.

D. Assiniboine River above its junction with the Red. Analyses C and D by F. D. Adams, Rept. 

Progress Geol. Survey Canada, 1878-79, p. 10 H.

E. Nelson River near its mouth.

F. Hayes River opposite York Factory. This stream enters Hudson Bay near the Nelson. Analyses 

E and F by W. Dittmar, Rept. Progress Geol. Survey Canada, 1879-80, p. 77 C.

C03 . ........................

S04 .........................

CL. ..........................

PO

N03 .........................

Ca... ........................

Mg....... ....................

Na

K.. ..........................

Li...........................

Si02 .........................

(Al,Fe) 203 ---- ................

Salinity, parts per million. . . . .

A

32.52

25.56

.69

30.39

1 Q7

1 1Q

.60

7.08

100. 00 

202

B

41. 20

15.71

4.89

.19

.28

17.55

8.23

ft fi4

1.37

.02

4.57

.35

100. 00

284

C

31.47

22.06

8.78

12.89

7.99

9.67

1.18

5.72

.24

100. 00 

551

D

39.70

16.52

5.58

13.59

7.72

11.08

1.16

4.41

.24

100. 00 

509

E

16.78

41.85

4.68

15.91

5.65

6.22

Q7

7.30

.64

100. 00 

180

F

50.36

3.08

21.88

ft 94

4.22

1.37

11.48

2.37

100. 00 

115

The following table gives analyses of Bow River and its tributaries, the Bow being the main western branch of the Saskatchewan. 

All these streams are in the Alberta district, Northwest Territory, 

Canada. The analyses were made by F. G. Wait. 1 The samples 

were collected at low water.

Analyses of water from Bow River and tributaries.

G. Bow River at Calgary.

H. Elbow River at Calgary.

I. Highwood River at High River.

J. Fish Creek at McLeod Trail. 

K. Sheep River near Dowdney.

C08 ..................................

S04 ......... ..........................

CL. ..................................

Ca... ....... ...........................

Mg... ................................

Na.. ........ ..........................

K.... ................................

Si08 ........ I..........................

FeaO3 ............ ......................

G .

48.21

M fiQ

, .94

25.23

6.95

2.42

Trace.

1.56

TVqr»p

100. 00

128

H

44.66

18.80

.56

24.39

6.55

2.77

.42

1.85

Trace.

100. 00 

217

I

47.78

13.22

.65

24.48

6.23

3.28

Trace.

4.36

Trace.

100. 00 

183

J

53.57

5.59

.51

18.82

7.57

7.14

1.34

5.46

Trace.

100. 00 

238

K

45.55

17 13

.57

23.69

6.32

3.92

.43

2.39

Trace.

100. 00 

209

1 Rept. Geol. Survey Canada, new ser., vol. 9,1878, pp. 39-45 R.
LAKES AND KIVEES. 89 

SUMMARY FOB NORTH AMERICA.

If now we look back over the analyses of North American rivers, 

we shall see that, in spite of all differences, certain general tendencies are manifest. In the first place, practically all the waters 

from east of Missouri River, with one or two minor exceptions, aro 

waters in which carbonates are largely in excess of sulphates and 

chlorides, and calcium is the dominating metal. The same rule 

holds for the extreme northern and northwestern rivers; but the 

western tributaries of the Missouri, in general, tell a different story. 

So also do the waters of New Mexico and Arizona. Here sulphates 

are in excess of carbonates, and calcium, although sometimes dominant, is not always so. In short, where the rainfall is abundant and 

the soil is naturally fertile, carbonate waters are the rule; in arid 

regions sulphates and chlorides prevail. This statement applies to 

the evidence now in hand, and must not be construed too sweepingly. 

We are dealing not with invariable laws but with tendencies.

The condition thus indicated is probably the outcome of various 

causes, but one of the latter is easily found. In a fertile region 

organic matter is abundant, and great quantities Of carbonic acid are 

generated by its decay. This carbonic'acid, absorbed by the ground 

water of the soil, acts as a solvent of mineral matter, and carbonates 

are carried into the streams more abundantly than other salts. In 

arid regions there -is less organic decomposition, less carbonic acid, 

and a smaller proportion of carbonates is found. Water from a 

swamp or forest is very different from water which has leached a 

desert soil. In Kansas River and its tributaries the passage from 

one set of conditions to the other is clearly apparent. Western Kansas is relatively arid, and the western branches of the river are poor 

in carbonates. Eastern Kansas is fertile, and the eastern affluents 

reflect its character. It must be borne in min,d, however, that we are 

now considering relative proportions of substances and not absolute 

amounts. The lower course of a stream is a blend of many waters; 

and the change from one type to another does not necessarily imply 

that anything has been lost. Precipitation may have taken place, 

but in many cases the transformation from sulphate to carbonate is 

probably due to an overwhelming influx of the latter. The Mississippi itself, in its course southward, must receive carbonates more 

freely than sulphates; and its final character as-it enters the Gulf of 

Mexico should be that of a carbonate water. So much at least can 

be safely inferred from the data already in hand. To small streams, 

it must be remembered, these considerations do not always apply. 

Local conditions are operative in such cases, and a river issuing from 

a region rich in gypsum, or fed by brooks affected by beds of pyrite,
90 ' DATA OF GEOCHEMISTRY.

may have a sulphate character quite independent of the climatic 

influences which otherwise seem to rule.

The local peculiarities of river water have been the subject of a 

considerable number of geochemical and hydrochemical investigations, some of which will be noticed later. In general it may be said 

that a water at or near its source reflects in some measure the composition of the rocks from which it rises. We have already seen 

the remarkable uniformity of .character displayed by the rivers of the 

South Atlantic and eastern Gulf States. The waters of IHinois and 

Iowa, flowing through a rich agricultural area, underlain by sedimentary rocks exclusively, show a similar uniformity of composition. Water from limestone is rich in lime, that from dolomite contains more magnesia, that from granite is characterized by relatively higher silica and alkalies. In small streams these resemblances 

appear quite clearly; in large rivers the coinmingling of the tributaries tends to produce an average composition which may be called 

that of a normal water. The great continental rivers resemble, one 

another much more nearly than do their component branches.

RIVERS OF SOUTH AMERICA.

The river waters of South America, except in British Guiana, 

Argentina, and Brazil, seem to have received very little attention 

from chemists. A. Muntz and V. Marcano 1 have described certain 

waters, from unnamed tributaries of the Orinoco and Amazon, which 

are colored nearly black by organic acids but contain not over 16 

parts per million of mineral matter, and from which lime is practically 

absent. These peculiarities are shared to some extent, although not 

so strikingly, by certain river waters of British Guiana, which are 

brown in color, low in salinity, and rich in organic matter. Fourteen 

of these waters have been analyzed by J. B. Harrison and K. D. 

Reid, 2 from whose table the following selection has been made. Their 

data are reduced here to the usual standard form, with normal carbonates and with organic matter omitted. The color is supposed to 

be due to organic compounds of iron, and the proportion of iron 

found, here reported as Fe203, is unusually large. As stated here 

the analyses represent the anhydrous inorganic matter which the 

waters could ultimately deposit.

1 Compt. Rend., vol. 107,1888, p. 908. See also J. Reincll, Natur. Wochenschr., vol. 20,1905, p. 353.

2 Official Gazette, Georgetown, Demerara, July 26.1913.
LAKES AND RIVEKS. 91

Analyses of ivaters from British Guiana.

A. Barima River above Eclipse Falls.

B. Waini River above First Falls.

C. Essequibo River above Wataputa Falls.

D. Demerara River above Malalli Falls. Another analysis of water taken in time of drought is also 

given.

E. Courantyne River.

F. Potaro River, above Tumatumari Falls. Analyses are also given of the Barama, Cuyuni, ruruni, 

Mazaruni, Rupununi, Mahaica, and Berbice rivers, and of Abary Creek.

co3 ...... ....................

S04 ............. .............. ci.!.......... ................

N03 ...... ...................

Ca...........................

Mg.. .........................

Na 

K........... .................

Si02 . ...... ..................

Fe203 .... .....................

Salinity, parts per million. ....

A

22.12

1.39

6.45

.51

10.21

4.01

2.67

.08

43.43

9.13

100. 00 

78

B

28.40

.92

6.50

.13

5.45

3.02

12.88

1.88

25.04

15.78

100. 00 

45

C

15.74

5.65

3.36

1.11

3.84

2.96

6.97

' .54

52.80

7.03

100. 00 

30

D

12.84

1.15

10.32

.97

.38

2.65

10.93

1.69

55.92

3.15

100. 00 

73

E

22.14

1.22

6.86

.30

5.16

2.39

8.75

2.65

41.90

8.63

100. 00

40

F

25.89

1.89

2.88

2.00

2.25

.97

18.14

1.26

38. 54

6.18

100. 00 

44

The very high silica and generally high sodium in these waters 

suggest that they emerge from areas of crystalline rocks. The high 

proportion of chlorine, however, with some of the sodium, may be 

due to cyclic salt, the saline content of rainf all.

In the next table I give the available data for the Amazon and 

some of its tributaries.

Analyses of water from Amazon River and tributaries.

A. The Amazon between the Narrows and Santarem. Analysis by P. F. Frankland, cited by T. Mellard Roado in Evolution of earth structure.

B. The Amazon at Obidos. Mean of two analyses by F. Katzer. See Grundziige dor Geologie dos 

unteren Amazonasgebietes, Leipzig, 1903. Katzer estimates that the Amazon carries annually past Obidos 

618,515,000 metric tons of dissolved and suspended matter.

C. The Xingu. Analysis by Katzer, loc. cit.

D. ThoTapajos. Analysis by Katzer, loc. cit. Katzer also gives analyses of water from Parana-mirim, 

the Maecuru, the Itapacura-mirim, and several fresh-water lakes or lagoons.

C03 .. ........................................

S04 ..... ......................................

Cl............ ................................

Ca. ............................................

Mg......... ..................................

Na.......... ..................................

K. ...........................................

SiOo.. .........................................

(Al»203 .- ..................... .............

Salinity, parts per million. ......................

A

34.75

7.37

3.85

21.12

2.57

1.94

2.31

18.80

7.29

100. 00 

59

B

24.15

2.26

6.94

14.69

1.40

4.24

4.76

28.59

19 Q7

100. 00

37

C

26.78

10.57

6.96

15.77

3.92

2.08

4.18

21.15

8.59

100. 00 

45

D

29.60

7.39

5.77

16.84

3.60

1.80

3.67

24.02

7.31

100. 00 

38
92 DATA OF GEOCHEMISTRY.

From the southern parts of South America the following waters 

have been analyzed:

Analyses of water from rivers in southern part of South America.0

A. River Plata 5 miles above Buenos Aires. Analysist>y J. J. Kyle, Chem. News, vol. 38,1878, p. 28.

B. River Plata near Buenos Aires. Analysis by R. Schoeller, Ber. Deutsch. chem. Gesell., vol. 20, 

1887, p. 1784. Water possibly affected by tidal contamination. For other data relative to the Plata and 

the Mercedes, see M. Puiggari, An. Soc. cient. Argentina, vol. 13, p. 49,1882.

C. The Parana 5 miles above its entry into the Plata. Analysis by Kyle, loc. cit.'

D. The Uruguay midstream opposite Sal to. Analysis by Kyle, loc. cit.

E. The Uruguay above Fray Bentos. Analysis by Schoeller, loc. cit.

F. Rio Negro above Mercedes. Analysis by Schoeller, loc. cit. An analysis of Rio Negro by Will is 

cited by S. Rivas, An. Soc. cient. Argentina, vol. 1,1877, p. 326.

G. Colorado River, Argentina. Analysis by Kyle, An. Soc. cient.- Argentina, voh 43, 1897, p. 19. In 

this memoir Kyle gives analyses of numerous Argentine rivers. The nomenclature, however, is confusing, 

for descriptive names, such as Negro, Colorado, Salado, Saladillo, etc., are applied to more than one stream 

in Argentina, and it is not always easy to identify the river to which a given analysis applies.

H. Rio Primero, Argentina.

I. Rio de los Papagayos, Argentina. Analyses H and I by M. Siewert, in R. Napp's The Argentine 

Republic, 1876, pp. 242, 244.

J. Rio Saladillo, Argentina. Analysis by A. Doering.

K. Rio de Arias, Salto, Argentina. Analysis by M. Siewert.

L. Rio de los Reyes, Jujuy, Argentina. Analysis by. M. Siewert. For analyses J, K, and L, see Bol. 

Acad. nac. cien. Cordoba, vol. 5,1883, p. 440.

M. Rio Frio, district of Taltal, Chile. Analysis by A. Dietze, cited by L. Darapsky in Das Departement 

Taltal, Berlin, 1900, p. 93.

N. Rio Copiapo, Chile. Analysis by P. Leme'tayer, cited by F. J. San Roman in Desierto i Cordilleras 

doAtacama, vol. 3, Santiago, 1902, p. 191.

CO,.. .......................

S04 ....... ..................

CL. ............. ............

NO,.. ...... ................. 

Ca. ........................

Mg................... ........

Na

K............ ..............

Si02 .. .......................

A1203 . .....................

Fe203 - .....................

Salinity, parts per million. . -

C03 .... ....................

S04 ........... ........ ......

01..........................

N08.. ......................

Ca. ........................

Mg...........................

Na............ ..............

K.......................... sio2 . :.....................

A1208 ......................

Fe203 . .....................

S..... ......................

Salinity, parts per million. . .

A

17.45

7.69

12.59

".6 "is"

3.31

17.34

3.09

21.32

6.62

4.41

100. 00 

91

H

39.47

5.76

6.41

16.53

3.27

') f)Q

4.67

8.58

1.10

5.12

m

100. 00 

160

B

11.59

17.97

18.11

6.68 

3.71

1.42

24.89

10.82

} 4.81

100. 00 

206

I

0.06

31.81

32.63

8.01

.36

26.48

.49

.16

100. 00 

9,185

C

17.73

10.13

15.92

"7." 27"

2.78

H Qtf

4.06

20.73

3.21

3.21

100. 00 

98

J

9.94

27.75

21.51

U 9Q

2.87

16.12

4.41

6.11

100. 00 

1,213

D

24.23

3.90

.61

5.50 

9.82

2.85

3.75

3.12

46.22

100. 00 

40

K

39.13

13.24

2.77

i9.63

5.20

1.82

5.75

11.57

.89

100. 00 

127

E

21.59

6.15

5.12 "io.'oi"

2.97

5.92

44.32

} 3.92

100. 00 

66

L

28.27

18.17

5.53

13.20

2.53

V 1Q

10.20

12.33

.49

2.09

100. 00 

104

F

39. 10

1.23

4.43

1.95 

17.82

1 Qfi

10.24

21.75

} 1.52

100. 00 

132

M

18.06

24.45

8.04

14 Q^

2.63

IK 07

13.22

3.30

100. 00 

186

G

8 1Q

30.58

24.51

"i6.24

1 4fl

15.78

3.24

100. 00 

651

N

6.46

38.50

Trace.

6.61

3.52

8.96

.36

35.39

} 2.20

100. 00 

731

a See also H. Corti, Bol. 6. se'rie D, Ministerio de Agricultura, Argentina, 1918, for an analysis of water 

from Rio Mina Clavero; and A. A. Bado, Bol. Acad. nac. cien., Argentina, vol. 23, pt. 1, p. 85,1918, for 

one of water from Rio Tercero.
LAKES AND RIVERS. 93

These waters show the same order of variation as those of North 

America. The water of the Amazon, flowing through forests and 

in a. humid climate, is characterized by dominant carbonates and low 

salinity. In Argentina many of the streams flow through semiarid 

plains. In their waters sulphates <and chlorides predominate and the 

alkalies are commonly in excess of lime. The Uruguay and some 

rivers of British Guiana are peculiar because of their high proportion of silica a condition which will be discussed later in this chapter.

LAKES AND RIVERS OF EUROPE.

Both Bischof and Roth cite numerous early and often incomplete 

analyses of European river waters, but it is not necessary to reproduce 

them all here. They tell the same story as that told by the eastern 

rivers of the United States. The predominance of calcium and the 

carbonic radicle is clearly shown in most cases. For present purposes it is well to begin with British waters, and then to pass on

eastward.

Analyses of British waters.

A. Loch Bailo a Ghobhainn, Lismorc Island, Scotland. Analysis by W. E. Tetlow, Proc. Roy. Soc., 

Edinburgh, vol. 25, 1905, p. 970. Organic matter not included in this recalculation. A typical calcium 

carbonate water springing from limestone.

B. River Dee near Aberdeen, Scotland.

C. River Don near Aberdeen.

Analyses B and C by J. Smith, Jour. Chem. Soc., vol. 4,1850, p. 123. Organic matter rejected.

D . The Thames at Thames Ditton. .

E. Tho Thames at Kew.

F. The Thames at Barnes.

Analyses D, E, F, by T. Graham, W. A. Miller, and A. W. Hofmann, Jour. Chem. Soc., vol. 4,1850, p. 

370. Analyses are also given of tho Thames at Battersea and Lambeth, of the New River, and several 

springs. For other analyses of tho Thames see J. M. Ashley, Jour. Chem. Soc., vol. 2, 1848, p. 74, and 

G. F. Clark, idem, vol. 1, 1848, p. 155. Also R. D. Thomson, idem, vol. 8, 1856, p. 97, and H. M. Witt, 

I'hilos. Mag., 4th scr., vol. 12,1856, p. 114. '

0. Lough Ncagh, Ireland. Analysis by J. F. Hodges, Chem. News, vol. 30,1870, p. 103. An analysis of 

the river Bann is also given.

Sco also C. M. Tidy, Jour. Chem. Soc., vol. 37,1880, p. 208, for partial analyses of the Thames, Lea, Severn, 

and Shannon. E. Hull, Geol. Mag., 1893, p. 171, cites analyses of Thirlmore, Bala Lake, and the Severn, 

which 1 am unable to trace to the original pubu'cations. In T. E. Thorpe's Manual of inorganic chemistry, 

vol. 1, p. 207, analyses'of tho Clyde and Loch Katrine arc given. For analyses of the River Trent, see Jour. 

Soc. Chem. Ind., vol. 30,1911, p. 70.

co8 ........................

S04 ..... ....................

Cl........ ..................

NO

PO

Ca. ........................

Mg.........................

NT,

K.................... ......

Si02 ...... ....... ............

A1203 .... ....................

Fe203 .......................

Salinity, parts per million. . . .

A

57.49

Trace.

1.41

Trace.

.02

37.77

.25

1 Q4

1.62

.50

100. 00 

160

B

23.35

15.70

17.08

17.22

2.98

113. 60

6.41

O.T3O

100. 00

31

C

23. 15

16.29

14.19

16.32

3.54

| 9.17

10.62

1 6.72

'

100. 00 

81

D

41.86

11.82

5.20

.84

30. 10

1.95

2.26

2.25

3.26

| .46

'

100. 00

272

E'

39.53

14.72

4.57

Trace.

28.57

1.82

3.28

1.55

2.36

> o. bU

'

100. 00 

266

F

33.90

18. 10

5.70

Trace.

27.00

1.70

3.70

1.10

5.00

| 3.80 '

100. 00 

286

G

35.23

10.68

9.62

17.71

1.31

15.41

3.32

6.72

100. 00 

155
DATA OF GEOCHEMISTRY.

The high chlorine and sodium, in some of these analyses is probably 

due in part to the proximity of the ocean. In the Thames the regular 

increase in these radicles as we follow the stream downward is quite 

evident. The Thames^ however, rises in the midland counties of 

England, where the waters issuing from the oolite are relatively rich 

in chlorides.1

The next group of analyses 2 relates to the waters of western Europe, 

namely of Belgium, France, and Spain. Some Swiss waters are 

included, as tributary to the Rhone.

Analyses of waters in western Europe.

A. The Meuse at Liege, Belgium. Computed from data given by W. Spring and E. Prost, Ann. Soc. 

gdol. Belgique, vol. 11, 1884, p. 123. The Meuse carries past Liege, in solution, nearly 1,082,000 metric 

tons of solids annually, or 139 tons from each square mile of territory drained'. Earlier analyses of the 

Meuse by J. T. F. Chandclon and J. W. Gunning arc cited by Bischof.

B. The Seine at Bercy. Analysis by H. Sainte-Claire Deville, Annalcs ehim. phys., 3d ser., vol. 23 

1S48, p. 42.

C. The Loire near Orleans. Analysis by Doville, loc. cit.

D. The Garonne at Toulouse. Analysis by Deville, loc. cit.

E. The Doubs at Rivottc. Analysis by Deville, loc. cit.

F. The Iserc. Analysis by J. Grange, Annalcs chim. phys., 3d ser., vol. 24, 1848, p. 496. Grange also 

gives analyses of several small tributaries and correlates them with their geological surroundings.

G. The Rhone at Geneva. Analysis by Deville, loc. cit.

H. The Rhone. Average of five analyses by L. Lossicr, Arch. sci. phys. nat, 2d ser., vol. 62,1878, p. 220. 

Organic matter rejected.

I. The Arvc. Average of six analyses by Lossier, loc. cit.

J. Lac Lcman. Analysis by R. Brandenbourg, cited by F. A. Forel in Mem. Soc. Helvct., vol. 29,1884. 

Forel cites several other analyses of Lac Leman. See also Risler and Walter, Bull. Soc. vaud., vol. 12,1878, 

p. 175.

K. Lac d'Annecy. Analysis by L. Duparc, Compt. Rend., vol. 114,1872, p. 248.

L. The Douro. Analysis cited in Mem. Com. mapa geol. Espafia, Proy. Salamanca. Anatyst not named.

003..........................

S04 . ....... .................. ei........ ....................

NO

Ca. .......................... Mg....... ........:...........

Na. ..........................

K.. ..........................

Li. ..........................

Si02 ...................-...'..

A1203 ------------------------

Fe2(V........... ............

Mn203 . ......................

A

36.48

13.13

3.83

 2.86

28. 90

2.68

2.24

.87

.05

6.02

| 2.94

100. 00

B

39.78

8.57

2.95

4.44

29.13

.63

2.87

.86

9.59

.19

.99

100. 00

254

C

C

30.92

1.72

2.16

14.31

1.34

6.93

1.64

Si. 59

5.29

4.10

100. 00 

134

D

33.07

5.59

1.40

18.99

.67

4.42

2.50

29, 53

2.28

1.55

100. 00 

137

E

50.41

1.53

.74

2.35

33.20

.40

1.53

.70

6.91

.92

i 31

,,

100. 00 

230

F

aw. 14

24.11

4,53

25.40

3.67

}

A Qf>

'

1.97

1.86

Trace.

100. 00

188

1 See W. W. Fisher, The Analyst, vol. 29,1904, p. 29.

2 J. Thoulet (Bull Soc. geog., 7th ser., vol. 15, 1894, p. 557) gives partial analyses of lakes in the Vosges. 

For French lakes in general, see A. Delebecque, Les lacs francais, Paris, 1898, See alsoA.Delebecqueaiid 

L. Duparc, Compt. Rend., vol. 114, 1892, p. 984; and Arch. sci. phys. nat., 3d ser.,voL 27,1892, p. 509; 

vol. 28, 1892, p. 502.
LAKES AND RIVERS.

Analyses of waters in western Europe Continued.

95

co...........................

S04 . ........................

01.... ........................

N03 . ........................

PO

Ca... ........................

Mg.. .........................

Na.....................:....

K... .........................

Si02 .........................

A1203 ........................

FeA.. .......................

Salinity, parts per million.. . . .

G

27.92

23.18

.55

3.13

24.89

1.48

2.75

.88

13. 08

2.14

100. 00

182

II

3G.69

26.68

.71

.31

26.42

3.66

1 3.98

1.55

100. 00 

170

I

42. 37

18.81

1.46

.32

29.64

3.17

"1 2.53

1.70

100. 00 

192

J

33.87

26.66

.52

27.81

2.23

2.53

.25

5.63

} .50 *

100. 00 

152

K

59.14

Trace.

.69

34.40

3.06

Trace.

Trace.

2.71

xTraces. '

100. 00

144

I,

33.73

23.37

7.74

41

23.93

6.05

2.00

1.64

1.03

.10

100. 00 

195

In the mountain complex of the Alps, including the Bavarian and 

Austrian highlands, several great rivers of western and central Europe 

take their rise. At their headwaters are many small lakes, and these 

have been exhaustively studied. In an elaborate thesis by F. E. 

Bourcart,1 analyses are giv/en of 33 Alpine lakes, and each one is discussed in the light of its geologic relations. The following table gives 

a selection from this mass of material:

Analyses of water from Alpine lakes.

A. Lac Taney, Canton Valais. In the Cretaceous. A typical calcareous water. Drains into the Rhone.

B. Lac do Champex, Canton Valais. In microgranulite and protogine. A type of the water derived 

from igneous rocks. Drains into the Rhone.

C., Lac Noir, Canton Fribourg. In the Flysch, but also fed by waters from the Trias. Drains through 

the Aar into the Rhine.

D. Lac d'Amsoldingen, Canton Berne. In the Flysch and Molasso. Drains into the Aar.

E. Lac Ritom, above Airolo, Canton Ticino. Surface water.

F. Lac Ritom, lower layer of water, below 13 meters depth. This lake drains southward into Italy.

CO,.. ........................

SO,..:................-.....

Cl...... ......................

Ca...........................

Mg..... ....................

Na..........................

K...... ......................

Si02 ......... ................

Al203+Fe203 a - ....-....--...

Salinity, parts per million. . . . .

A

53.21

5.29

.87

33.74

1.99

.75

.74

2.37

1.04

100. 00 

122

B

29.96

11.93

9.96

19.15

1.32

8.32

4.00

13.93

1.43

100. 00

27

c

26.94

38.35

.57

29.65

2.27

.64

.38

.71

:49

'lOO. 00 

270.5

D

53.84

3.32

1.77

33.30

1.76

1.80

.93

3.03

.25

100. 00 

201. 7

E

20.00

47.27

22. 12

5.47

1.22

1.64

2.28

Trarp

100. 00 

122.5

F

2.29

69.89

22. 15

4.96

.09

.15

.42

.05

100. 00 

2, 373

a Including traces of manganese.

1 Thesis, Univ. Geneva, 1906. Les lacs alpines suisses, 4° 

Arch. sci. phys. nat., 4th ser., vol. 15,1903, p. 467.

130 pp. A for/ selected analyses appear in
96 DATA OF GEOCHEMISTRY.

Analyses A to D well illustrate the differences in origin of the 

waters. E and F represent a lake of extraordinary character. It 

contains two distinct layers of water of quite dissimilar nature. The 

upper layer is merely the water of its affluents, which flows over the 

denser water below. The latter is essentially a strong solution of 

calcium sulphate, derived from neighboring beds of gypsum. The 

two layers do not commingle, and the lower one has a distinctly higher 

temperature than the upper, except at the surface. At 11 meters 

depth the temperature is 5.1°; at the bottom it is 6.6°. A similar 

phenomenon, but even more strongly marked, is shown by the Hlye's 

Lake in Hungary, which will be described later.

The following table contains recalculated analyses of water from 

several lakes in the Bavarian and Austrian highlands.1 They belong 

to the basin of the Danube, into which they drain through the valleys 

of the Isar, Inn, and Traun. One Italian lake is included in this table 

on account of its Alpine relationship.

Analyses of water from Bavarian and Austrian lakes.

A. Walchensee.

B. Kochelsee.

C. Starnberger- or Wurmsee.

D. Tegernsee. Mean of two analyses.'

E. Schliersee. Mean of two analyses.

F. Chiemsee. Mean of five analyses.

G. Konigsee. Mean of two analyses.

Analyses A to G by A. Schwager, Geognost. Jahreshefte, 1894, p. 91; 1897, p. 65. All these lakes are in 

the Bavarian highlands.

H. Hallstiittersee, Upper Austria. Mean of two analyses, summer and winter samples, by N. von 

Lorenz, Mitt. Geog. Ges. Wien, vol. 41,1898, p. 1.

I. Traun- or Gmundenersee, Upper Austria. Analysis by R. Godeffroy, Jahresb. Chemie, 1882, p. 

1623. Organic matter rejected.

J. Lago di Garda, northern Italy. Analysis by Schwager, Geognost. Jahreshefte, 1894, p. 91. Analyses 

of Italian waters seem to be rare. For partial analyses of three small streams near Oderzo, in northwestern 

Italy, see M. Spica and G. Halagian, Gazz. chim. ital., vol. 17, 1887, p. 317.

COj..................................

S04 .................................

Cl. ..................................

N03 .. ...............................

Ca. ..................................

Mg........ ...........................

Na. .................................

K

Si02 . ......;.........................

AI r>

Fe203 . ...............................

Ti02 . ................................

A

50.83

11.62

.58

26.49

7.00

.99

.58

1.00

\ M

100. 00 

121

B

48.46

14.78

.48

24.66

6.17

1.52

1.52

1.60

.73

.04

.04

100. 00

227

C

54.69

4.73

1.57

.07

24.09

7.98

.96

2.14

1.26

2.44

.07

100. 00 

139

D

48.25

15.24

.58

26.17

6.56

1.10

.88

.44

.73

.05

100. 00 

207

E

50.74

11.15

.55

26.94

5.78

1.05

1.07

1.62

1.05

.05

100. 00 

190

» See also incomplete analyses of the Starnberger, Kochel, and Walchen lakes by J. Gebbing, Jahresb. 

Geol. Gesell. Munchen, 1901-2, p. 55. Also W. Ule's monograph on the Wurmsee, published by the Verein 

fur Erdkunde, Leipzig, in 1901.
LAKES AND EIVEES. 97

Analyses of water from Bavarian and Austrian lakes Continued.

C08 ..................................

S04 .. ...............................

01. ..................................

PO

Ca. ..................................

Mg... ................................

Na. .................................

K...... ..............................

SiO................................. AI n

Fe208 . ...... .........................

Salinity, parts net million .............

F

49.58

12,09

1.92

23.22

8.17

2.18

.97

.92 .89'

.06

100. 00 

191

Cr

50.59

6.54

.65

.05

32.65

3.41

.70

1.24

1.73

9 33

.11

100. 00 

98

H

38.43

9.43

10.94

26.37

3.88

6.50

2.77

1.3107

100. 00 

137.5

I

51. G8

8.99

2.44

27.54

5.21

2.82

.31

1.01

100. 00 

99

J

53.29

4.17

3.13

24.56

6.66

2.49

2.01

2.33

1.21

.15

1 00. 00

178

These lakes are surrounded by sedimentary rocks, and all except 

that of Hallstatt are much alike chemically. Magnesium, with two 

exceptions, is decidedly above its average amount in lake and river 

waters, a fact which is due to the presence of much dolomite in the 

lake region. The high chlorine and sodium of the Hallstatt lake are 

derived from neighboring salt beds.

For the Rhine and its tributaries a good number of analyses are 

available.1 The following table contains a part of them, recalculated 

to modern standards, with organic matter rejected:

Analyses of water from the Rhine and its tributaries.

A. Lake of Zurich. Analyses by Moldenhauer, 1857, cited by Roth, Allgemcinc uncl ohcmische Geologic, 

vol. 1, p. 456.

B. The Aar at Bern. Analysis by J. S. F. Pagenstcchcr, 1S37, cited by Roth.

C. Tho Rhine at Basel. Analysis by Pagcnstccher, loc. cit.

D. The Rhino at Strasburg. Analysis by H. Saintc-Claire Deville, Annalcs chim. phys., 3d scr., vol. 23, 

1848, p. 42.

E. Tho Rhino near Mainz. Analysis by E. Eggcr, Notizbl. Ver. Erdkundc, Darmstadt, 1887, p. 9. An 

earlier analysis is in the volume for 1886, p. 21.

F. Tho Rhine at Cologne. Mean of seven analyses by H. Vohl, Jahrcsb. Chemie, 1871, p. 1323.

0. Tho Rhine at Arnhcim. Analysis by J. W. Gunning, Jahresb. Chemie, 1854, p. 7G7.

00... .......................

S04 . ......................

Cl. ........................

N08 .. .....................

PO

Ca.. .......................

Mg.........................

Na. .......................

K.................. ........

Si02 . ......................

A1203 .....................

Fe203 - .....................

Salinity, parts per million ....

A

51.64

7.90

.59

29.10

5.11

1.60

2.00

2.06

100. 00 

141

B

48.60

14.63

.08

30.54

4.71

}

i & .lu

1.26

100. 00 

213

C

53.05

7.96

.57

33.53

2.87

}

.7373 

1 9Q

100. 00 

166

D

36.69

8.38

.52

1.00

25.30

.61

2.17

.66

91 07

1 OQ

2.51

100. 00 

232

E

41.12

11.13

3.65

1.63

(a)

31.81

3.95

2.08

1.05

9 fiQ

} .89 '

100. 00

178

F

4f> Qfi

12.95

4.22

. .24

26.48

6.15

2.73

.02

.15

.04

.06

100. 00 

190

a

qc 70

TO 00

7.10

26.18

3

04

fi 34

4 04

3

CQ

} .89 '

100. 00 

159

i For an imperfect analysis of the Bodensee (Lake of Constance) see H. Bauer and H. Vogel, Jahrcshefte Ver. vatnrl. Naturk.' Wiirttemberg, vol. 48,1892, p. 13. Many partial analyses of waters from Rhino 

tributaries are given by E. Egger, Notkbl. Ver. Erdkunde, Darmstadt, 1908, p. 105; 1909, p. 87. These 

two papers are on the hydrochemistry of the Rhine.

113750° 19 Bull. 695 7
98 DATA OF GEOCHEMISTRY.

Analyses of ivater from the Rhine and its tributaries Continued.

. II. Th& White Main.

I. The Red Main.

,T. The united Main. Analyses H, I, and J by E. Spaeth, Inaug. Diss. Erlangen, 1SSO. £paeth also 

gives analyses of water from the Rodach, Haslach, and Kronach, tributaries of the Main.

K. The Main above Oflenbach. Analysis by C. Merz, Jahresb. Chemie, 1866, p. 987.

L. The Main at Frankfort. Analysis by G. Kerner. Cited by F. C. Noll, Inaug. Diss. Tubingen, 1866, 

from a report published at Frankfort in 1861.

M. TheMainnear its mouth. Analysis by E. Egger, Notizbl. Vcr. Erdkunde, Darmstadt, 1886, p. 17.

N. The Nahe at Bingen. Analysis by Egger, idem, 1SS7, p~5.

C08 . .......................

S04 . ......................

01. ........................

N03 .. .....................

PO

Ca, ........................

Mg. ........................

Na.........................

K.. ........................

Si02 . .......................

Al O

Fe,,03 . .....................

Salinity, parts per million ....

H

36.15

16.33

5.60

1.66

22.58

4.26

4.10

1.66

6.47

| 1.19 '

100. 00 

126

I

41.83

14.89

5.00

.71

23.91

5.85

2.64

1.75

3.10

} .32 '

100. 00 

194

J

39.69

15.46

.4.76

1.43

23.07

5.52

2.86

2.04

4.69

} .48 '

100. 00

147

K

34.39

26.41

4.69

23.56

6.90

1.73

1.90

\ 42 r **

100. 00 

240

L

35.85

24.69

1.91

. 21. 81

7.30

1.25

6.67

1 52

? . OLI

'

100. 00 

221

M

29. 43

22.43

8.39

1.12

(a)

19.57

5.77

6.64

1.44

4.12

.99

.10

100. 00 

299

 N

35.43

7.91

15.37

2.61

.41

18.64

5.54

4.28

5.40

4.05

} .36 *

100.00

182

a Included witlvAloOg, etc.

These' analyses are evidently of very unequal value. The high 

silica found in the Rhine by Deville is suspicious, and yet Deville was 

an accurate manipulator.

One of the most thorough hydrochemioal studies ever made of any 

European river system is that of the Elbe and its Bohemian tributaries by J. Hanamann.1 In "two memoirs upon the waters of Bohemia he gives over one hundred and twenty analyses, tracing nearly 

all of the important streams in the upper Elbe basin to their sources, 

correlating each one with the geological formations in which it rises, 

and showing the effect produced by their union. Of the Elbe itself 

thirteen analyses are given; of the Eger, eight; of the Iser, six; 

and so on. From this wealth of material only a small part can be 

reproduced here, recalculated as usual to our uniform standard and 

beginning with the tributaries. A few analyses are also given from 

a rich mass of data derived from other authorities.2

1 Archiv Natur. Landeadurchforschun'g Bohmen, vol. 9, No. 4,1894; voLlO, No. 5,1898.

a Other data relative to the Elbe and its tributaries are given by J. J. Breitenlohner (Verhandl. K.-k. 

geol. Reichsanstalt, 1876, p. 172) and F. Ullili (Abhandl. K. bohm. Gesell. Wiss., 6th ser., vol. 10,1880). 

For analyses of the Elbe at Lauenburg, Hamburg, and Neufeldt, see H. Siissenguth, cited by F. Schucht, 

Jahrb. K. preuss- geol. Landesanstalt, vol. 25,1897, p. 442. An analysis of the Moldau at Prague by F. Stolba 

is given in Jour. Chem. Soc., vol. 27,1874, p. 971. For an analysis of River Radbuza above Pilsen, see the 

same author, Jahresb. Chemie, 1880, p. 1521. According to A. Schwagor (G-eognost. Jahreshefte, 1891, p. 

35), the Saalo carries ont of Bavaria, annually, 17,380,000 kilograms of dissolved matter, and the Eger carries 

14,000,000 kilograms. For additional data on the waters of the Elbe and the Saale, see R. Kolkwitz and 

F. Ehrlich, Mitt. K. Priifungsanstalt fiir Wasserversorgung, Heft 9, Berlin, 1907, p. 1.
LAKES AND RIVERS. 99

Analyses of the Elbe and its tributaries.

A. The Moldau above Prague. Mean of three analyses by A. BClohoubek, Sitzungsb. K. bohm. Gcscll, 

Wiss., 1876, p. 27. "'

B. Tho Moldau below Kralup.

C. Tho Adler near its mouth.

D. Tho Iser at its source.

E. The Iser near its mouth.

F. Tho Egcr at its source. Analysis by E. Spacth, Inaug. Diss., Erlangcn, 1889.

G. The Eger above Konigsberg.

H. The Eger near its mouth, at Bauschowitz.

I. Tho Saalc near its source. Analysis by Spaeth, loc. cit.

J. Tho Saale at Blankcnsteiu. Analysis by A. Schwager, Geognost. Jahrcshef tc, 1891, p. 91. Schwager 

also gives analyses of the Saalo at three other points, of its tributaries the Pulsnitz, Schwesnitz, Eegnitz, 

and Selbitz, of the Eger, and of the upper Main.

K. The Weisswasser, one of the two chief sources of the Kibe.

L. The Elbe at Cclakowitz, above the mouth of the Iser.

M. Tho Elbe at Melnik, above the mouth of the Moldau.

N. The Elbo at Leitmcritz, above the Eger.

0. The Elbe at Lobositz, below the Eger.

P. Tho Elbe at Tctschcn, near the Bohemian frontier.

Tho analyses arc by Hanamann, except whore otherwise stated.

co3 ... ...............

so4 <.. ..............

01....................

NO

PO

Ca......... ..........

Mg.. ........... ......

Na..................

K....................

Si02 .. ...............

(Al,Fe) 2 03 ------------

Salinifcy, parts per

A

32.86

11. 95

10.69

.47

'13.52

4.88

10.22

5.19

8.96

1.26

100. 00

74

B

34.52

10. 20

10.17

1.76

.36

16.71

4.64

8.40

4.05

4,99

4.20

100. 00 

104

C

46.23

7.44

3.20

1.43

26.73

2.45

4. 2£

2.38

5.53

.32

100. 00 

195

D

21.29

6.94

11.08

1.24

8.14

2.19

13.86

5.54

28.39

1.33

100. 00 

16

E

47.74

6.55

3.00

.78

28. is

2.47

3.71

2.01

4.96

.63

100. 00

183

F

11.68

7.06

23.85

6.79

2.24

11. 93

6.71

26.07

3.67

100. 00

17

Or

26.64

19.22

8.16

.50

12. 86

3.51

11.66

2.98

12. 19

2.28

100. 00 

80

H

26.84

27. 45

 6.55

.46

15. 42

4.05

10. 46

3.50

4. 17

1.10

100. 00 

176

ro ou3 .... ............ ..

so,. ................

01....................

No' NO

Ca......... ..........

Mg............. ......

Na

K. ...................

SiO,. ...... ..........

A12 63 - - --- -- ----- 

Fe208 ..... ...........

Salinity, parts per

I

14.71 

5.84 

19.40

4.02 

6.37 

9.90 

4.66 

35. 10

iTraces

100. 00 

17

j

27.01 

20.94 

10.34 

.43

1.62 

14.19 

5.98 

8.98 

2.99 

4.79 

1.88 

.85

100. 00 

117

1C

16.84 

12.86 

7.61

4.28 

8.76 

2.19 

11. 06 

2.01 

31.21

j- 3.18

100. 00 

13

L

45.87 

8.95 

3.27

.90 

26. 41 

3.21 

3.93 

2.46 

4.09 }.«

100. 00 

221

M

45.04 

8.88 

3.56

.94 

26.37 

2.77 

4.02 

3.06 

4.66

1 .70

100. 00 

205

N

40.27 

10.86 

5.00

1.22

22.87 

3.24 

5.62 

2.79 

7.27

1 .86

100. 00

157

0

38. 41 

12.45 

5.96

1. 28 

22. 19 

3.23 

6.35 

2.87 

6.42

}.«

100. 00 

153

r

35.88 

14.88 

5.87

1.40 

20.92 

3.63 

6.09 

3.16 

7.13

} 1.04

100. 00

148

At their sources these streams are characterized by very low 

salinity and a high proportion of silica and alkalies. They grad-
100 DATA OF GEOCHEMISTRY.

ually increase in salinity, and by blending one with another approach 

more and more nearly the normal type of river waters. The Eger 

is unusually rich in alkalies and chlorine. The minor tributaries of 

the Elbe vary widely in composition, but hi general calcium and carbonates are the chief constituents. In the Schladabach, however, 

a small affluent of the Eger, sodium and the sulphuric radicle predominate, and in the Chodaubach, another tributary of the same 

river, there is a solution of gypsum with no carbonates. When the 

Sohladabach enters the Franzensbad moor it carries 94 parts per 

million of fixed mineral matter; it leaves the moor with a load of 

1,542 parts. This change serves to show the importance of ground 

water in modifying the chemical character of a stream a point 

already noticed in studying the rivers of Colorado. For details concerning these and many other small tributaries of the Elbe basin, 

Hanamann's original memoirs-should be consulted. They will well 

repay careful study.

One table of analyses given by Hanamann is peculiarly instructive. 

It consists of averages, showing the composition of Bohemian waters 

as related to the rocks from which they flow. These averages, 

reduced to the standard herein adopted, are as follows:

Average composition of Bohemian waters, classified according to source.

A. From phyllite, five analyses. 

B. From granite, six analyses. 

C. From mica schist, six analyses.

D. From basalt, four analyses.

E. From the Cretaceous, four analyses.

cos .... .............;.. ..............

S04 ......... ..........................

Cl............ ........................

Ca.....................................

Mg... ................................

Na..... ...............................

K......................................

Si02 ............... ....................

Fe2 03 .................. ................

Salinity, parts per million. .............

A

35.94

6.45

10.15

11.91

5.02

11.20

4.39

14.94

100. 00

48

B

30.49

14.12

6.39

11.89

3.58

10.57

5.63

17.33'

100. 00 

65

C

32.14

12.86

7.24

12.61

5.08

10.85

4.22

15.00

100. 00

74

D

46:85

7.94

1.66

20.07

5.76

6.22

3.20

7.67

.63

100. 00 

343

E

33.01

27.69

2.87

22.12

5.29

3.43

2.72

2.87

100.00 

603

The high figures for silica and sodium in the first three of these 

analyses reflects the origin of the waters in areas of crystalline rocks.

The water of the Danube and its tributaries above Vienna has been 

the subject of many investigations. The following table contains a 

selection from among them. Except as otherwise stated the analyses 

are by A. Schwager.1

1 Geognost. Jahreshefte, 1893, p. 84. In Schwager's analyses the iron is given as FeO. It is here recalculated into Fe2O3 . Traces of Mh, TiO2, and P2O6 are ignored.
LAKES AND RIVERS.

Analyses of ivater from the Danube and its tributaries.

101

A. The Woernitz above Wassertriidingen, Bavaria.

B. The Altmuhl above Herrioden, Bavaria.

Analyses A and B by E.Miiller,Inaug.Diss., Erlangen, 1893. Other dissertations upon Bavarian waters 

areby E. Kohn, 1889; M. Lechler,1892; J. Mayrhofer, 1885; all from Erlangen. Spaoth's dissertation has 

already been cited. There is also one from Wiirzburg, by F. Pecher, 1887. In each dissertation the waters 

are studied geologically.

C. The Naab.

D. The Regen. For older but incomplete analyses of the Regen, Hz, and Rachelsee, see H. S. Johnson, 

Liobig's Annalen, vol. 95,1855, p. 230. An analysis cf Danube water taken at Vienna was made by G. 

Bischof in 1852. An analysis of the Naab at its source is given by Spaeth, loc. cit.

E. The Isar. For an analysis of the Isar at Munich, see G. Wittstein, Jahresb. Chemie, 1861, p. 1097.

F. The Vils at Vilshofen. Analysis by C. Metzger, Inaug. Diss., Erlangen, 1892. Metzger also gives 

analyses of the Regen, Naab, Ilz, and Inn, of the two Arber Lakes and Black Lake at the headwaters of 

the Regen, of the Luhe, Pfreimt, and lesser Vils, tributaries of the Naab, and of the Danube at five different points. His work curiously overlaps or coincides with that published by Schwager. It includes 

geologic correlations.

G. The Ilz.

H. The Inn.

I. The Erlau.

J. The Danube above the Naab.

K. The Danube above Regensburg.

L. The Danube above the Hz and Inn.

M. The Danube 12 kilometers below Passau.

N. The Danube at Greifenstein, 20 kilometers above Vienna. Mean of 23 analyses,by J. F. Wolfbauer. 

of samples taken at intervals of 16 days throughout the year 1878. Monatsh. Chomie, vol. 4,1883, p. 417,

0. The Danube at Budapest. Analysis by M. Ballo, Ber. Deutsch. chem. Gesell., vol. 11,1878, p. 441. 

Bicarbonates are here reduced to normal salts.

r\r\

S04 . ................

Cl. ...................

N02 ..... ............

NO

Ca...................

Mg..... ........ ......

Na.... ..............

K.............. .......

Si02 ....... ..........

Ala03 ...... ..........

Fe2 03 -- ..............

Salinity, parts per 

million.. ..........

C08 ...................

S04 ....... ...........

Cl... ......... .......

NO...................

NO

Ca....................

Mg.. ................

Na... ................

K. ....................

Si02 ... ......... ......

A1203 ..... ............

FeA.................

Salinity, parts per

A

41.14 

19.36 

3.66

21. 8J 

7.54 

2.37 

2.29 

1.28

} .55

100. 00 

325

I

16.77 

14.78 

5.75 

.41

.41

8.62 

1.50 

8.95 

4.37 

28.73 

9.30 

.41

100. 00 

47

B

12.64 

50.31 

1.93

23.63 

1.15 

1.26 

7.40 

.98

 '.70

LOO. 00 

461.5

C

47.23 

9.54 

4.42 

.11 

.23 

20.70 

8.14 

3.11 

1.81 

3.51 

.90 

.30

100. 00 

110

J

53.51 

7.11 

1.20

.23 

26.88 

6.21 

1.47 

.96 

1.59 

.78 

.06

100. 00 

217

D

27. 55 

11.14 

5.88 

.37 

.71 

12.07 

4.02 

6.5,0 

4.37 

19.50 

6.50 

1.39

100. 00 

38.3

.K

51.70 

.8.54 

1.31 

.06 

.25 

27.40 

6.00 

1.12 

.72 

2.42 

.42 

.06

100. 00 

204

E

49.53 

12.07 

.46

25.65 

6.04 

2.14 

1.41 

1.45 

1.04 

.21

100. 00 

203.5

L

50.16 

8.85 

1.20 

.06 

2.14 

26.59 

6.01 

1.34 

1.12 

2.01 

.46 

.06

100. 00 

201

F

52.43 

3.29 

2.01

21.81 

7.85 

3.67 

4.79 

3.72

}.«

100. 00

217

M

43.29 

10.52 

2.25 

.06 

1.19 

65.46 

6.31 

1.84 

1.36 

2.20 

.46 

.06

100. 00 

184

G

15. 87 

18.26 

2.78 

.59 

.59 

4.37 

2.18 

9.92 

4.37 

32.54 

7.94 '.59

100. 00 

30

N

50.10 

8.81 

1.44

1.24 

26.28 

5.95 

1.69 

.94 

3.35

.20

100. 00 

1.67

H

44.85 

14. 40 

2.20 

.09 

.28 

15.10 

6.23 

2.20 

1.13 

2.89 

.44 

.19

100. 00 

166

0

49.03 

13.69 

1.40

26.78 

6.97 

.93

1.20

Trace.

100. 00 

151
102 DATA OF GEOCHEMISTRY.

Although the tributary waters (which should include the waters of 

the Bavarian lakes as given in a previous table) show great differences in character, the regularity exhibited by the Danube itself is 

very striking. The water of the Danube is essentially a calcium 

carbonate water, but the sulphates in it tend to increase in going 

downstream. According to Wolfbauer, the river carries past Vienna 

a daily charge of 25,000 metric tons of matter in solution. This is 

equivalent to an annual load of 9,125,000 metric tons. The mechanical sediment transported at the same time is only three-fifths as 

much.

Analyses of a few more waters of central Europe are given in the

next table. 1

Analyses of ivatcr from central Europe.

A. The Weser at llekum, 41 kilometers above its mouth. Mean of two analyses by F. Scyfcrt, Inaug. 

Diss., Rostock, 1893. Contamination, tidal or other, is evident.

B. The Oder near Brcslau. Sample taken at high water. Analysis by 0. Luodccke, Das Wasscr dcs 

Oderthales, etc., Leipzig, 1907. Another sample at low water showed contamination. Other analyses of 

ground and well waters are given.

C. The Vistula at Culm. Analysis by G. Bischof, Lehrbuch dor chemischen und physikalischcn Geologie, 2d cd., vol. 1,1863, p. 275.

D. Balaton- or Plattensee, Hungary. Analysis by L. von Ilosvay, in Resultate der wissensch. Erforsch. 

Balatonsees, vol. 1,1898, p. G. Reduced from bicarbonate form.

CO..............................................

so.;...........................................

Cl............................................

Ca.............................................

Mg. ..........................................

Na.. ..........................................

K. ...........................................

SiOo........... ................................

A1203 ..........:..............................-.

FeoO, ..........................................

. A

22.13

22.77

17.54

18.50

3.11

10.25

1.95

3.75

100. 00 

281

B

17.92

23.60

5.45

28.09

3.28

6.45

5.35

6.57

} 3.28 ^

100. 00 

91.5

C

47. 78

9.49

2.70

28.52

4.44

1.57

.39

4 49

. 62

100. 00

178

D

38.80

21.47

2.98

8.87

12.81

6.14

3.27

4.48

.82

.36

100.00

512

The Balaton Lake has an exceptional composition. The other 

analyses in the table are of minor importance. The rivers represented by them need more study.

For Sweden a single table of analyses must suffice, reduced from 

the data given by O. Hofman-Bang.2 The month in which the 

water was taken is given for each analysis.

1 For three small lakes near Halle and Eisleben see W. Ule, Die Mansfelder Seen, Inaug. Diss., Halle, 

1888. A memoir by J. Wolff (Chemische Analyse der wichtigsten Fliisse und Seen Mecklenburgs, Wiesbaden, 1872) contains analyses of several small rivers and lakes. Sec also A. Jentzsch (Abhandl. K. preuss. 

geol. Landesanstalt, new ser., Heft 51, p. 98,1912) for other analyses of North German lakes.

2 Bull. Geol. Inst. Upsala, vol. 6,1905, p. 101. In addition to his own work the author cites other analyses 

of Swedish river and spring waters. Solvent denudation in Norrland he estimates at 9 metric tons per 

square kilometer, or 23.3 tons per square mile.
i LAKES AND KIVEES. 103

A. The Byske-olf, July. 

B. The Klarelf, April. 

C. The Klarelf, October. 

D. The Ljusnan, June.

Analyses of Sivedisli 'waters.

E. The Indalself, June. 

F. Tho Fyris, April. 

G. The Fyris, October.

Of)

so...................

01...................

NO

PO

Ca....................

Mg...... ............

Na......... ..........

K...................

SiOa..................

(Al,Fe) 203 - - ---..

Salinity, parts per 

million......... . . ..

A

50.60

4.10

4.75

11.57

.64

9.90

9.00

7.57

1.96

100. 00 

19.25

B

39.44

5.85

5.10

14.95

.51

1 18.77

13.09

2.29

100.00 

27.6 '

c

38.68

7.63

2.24

.46

11.67

.51

8.42

3.78

19.17

7.44

100.00 

25.5

D

43 11

4.57

4.53

Trace.

17.34

.24

9.05

5.87

13.70

1.59

100.00

24.8

E

43.93

7.24

3.81

Trarp

18.04

.38

11.33

4.89

5.78

4.60

100.00 

33.7

F

29.14

24.58

3.15

Trace.

27.49

1.69

2.92

2.36

6.00

2.67

100. 00 

170.3

Cr

14.30

39.08

3.27

.13

27.99

2.11

3.33

1.73

6.19

1.87

100.00 

178. 1

The remarkably low magnesia and high proportion of alkalies are 

distinctive peculiarities of these waters. The variability, of the 

Fyris affords another good example of the fact that little significance 

can be attached to a single analysis of a river water. 

Of Russian fresh waters only a few analyses are available, as follows:

Analyses of Russian ivaters.

A. The Angernsee. Mean of two analyses.

B. The Babitsce.

Analyses A and B by F. Ludwig, Die Kiistensecn des Rigacr Mecrbusens, published by the NaturforscherVcrcin at Eiga, 1908. This memoir contains analyses of 27 small lakes near Riga and close to the Gulf of 

Riga. Most of them are of calcium carbonate waters, but in a few the sulphate is predominant.

Analyses C to G arc all by C. Schmidt of Dorpat.

C. Lake Onega. Mel. chim. phys. Acad. St. Petersburg, vol. 11,1S82, p. 637.

D. Lake Peipus. Bull. Acad. St. Petersburg, vol. 24,1878, p. 423. Schmidt has also analyzed water from 

the small rivers Embach and Velikaya, tributary to Lake Peipus. SceMdl. chim. phys., vol. 8,1873, p. 49-1.

E. The Dwina at Archangel. Analysis cited by J. Roth, Allgemeine chemische Geologic, vol. 1, p. 457.

F. River Om above Omsk. Mem. Acad. St. Petersburg, vol. 20, No. 4,1873.

G. Lake Baikal, Siberia. Same reference as analysis B.

H. The Dniester near Odessa. Analysis by J. G. N. DragcndorfF, Jahresb. Chemie, 1863, p. 885.

Partial analyses of five Finnish river and lake waters are given by O. Aschan, Jour, prakt. Chemie, 2d ser., 

vol. 77,1808, p. 172. For an analysis of the small Lake Ingol, Government of Ycncseisk, Siberia, see S. S. 

Zaleski, Chcm. Zcitung, vol. 1C, 1892, p. 59-1.

on

so4 .......... .......

01....................

NO...... ............ P0j. \j^ 4 ................. ...........:..

Ca...................

Mg............. ......

Na.... ..............

K.. ..................

Eb..... .............

NTT

SiOa ....... ..........

Al,03 .. ..............

Fe2 03 ... ...... .......

Salinity, parts per 

million.. ..........

A

51. 80

7.51

2.99

23.57

7.89

2.18

1.00

1.61

.57

.88

LOO. 00 

131

B

40. 14

23.45

1.09

27.10

5.49

.88

.33

.84

.55

.13

100. 00 

238

C

25.76

5.36

13.97

4.11

.47

8.99

6.86

13.34

9.52

.11

.56

10.52

.43

100. 00

49.4

D

59.57

 .62

3.69

.45

.14

25.54

4.15

2.75

2.07

.10

.78

.14

100. 00 

10G

E

26.38

18.95

17.71

.29

12.38

7.58

8.98

5.55

1.74

.44

100. 00

187

F

43. 73'

2.15

12.81

11.24

9.68

9.64

2.82

Trace.

6.51

1.42

100. 00

447

G

49.85

6.93

2.44

.21

.72

23.42

3.57

5.85

3.44

.08

2.03

1. 40

1.00. 00 

69

H

32.51

23. 62

8.93

25.25

5.33

.61

3. 75

100. 00 

197
104 DATA OF GEOCHEMISTRY.

RIVERS OF INDIA AND JAVA.

Analyses of Asiatic fresh waters, apart from the two Siberian 

examples cited in the preceding table, seem to be very rare. A few 

only are available for citation.

Analyses of waters from India and Java.

A. The Mahanuddy near Cuttack, India. Analysis by E. Nicholson, Jour. Chem. Soc., vol. 20, 1873, 

p. 229. Fe recalculated into I^Oa. Part of the silica is probably combined as a silicate, being needed to 

saturate the bases.

B. The Serajoe at Djenggawoer, Java. Analysis by E. C. J. Mohr, Mededeelingen Dep. Landbouw, 

No. 5, Batavia, 1908, p. 81. Another analysis is given of the river at another point

C. The Merawoe. Analysis by Mohr.

D. The Pekatjangan. Analysis by Mohr.

The last two rivers are tributaries of the Serajoe. Mohr did not determine carbonic acid. It is here 

calculated, in all three analyses, to satisfy bases. The salinity here therefore differs from that given by 

Mohr.

C08 .... ............ ............................

S04 ..... ......................................

 1............................................

NO

PO

Ca............. ................................

Ms................. ............................

Na.......... ..................................

K.................. ............................

Si02 ........... ................................

A1203 ----- .....................................

Fea08 .. ........................... .............

A

27.06

1.08

2.04

7.44

.72

15.78

4.62

5.92

1.64

33.45

.25

100. 00 

86

B

26.01

14.78

5.74

1 64

11.75

3.45

9.12

3.37

23.81

| .33

'

100. 00 

122

C

29.38

16.84

5.61

1.31

14.69

3.37

4.95

3.83

19.65

| .37

'

100. 00 

. 107

D

30.84

18.26

3.04

1.21

16.64

2.43

6.59

3.34

17.25

| .40 *

100. 00 

99

The Mahanuddy rises in a region of igneous and crystalline rocks, 

and its silica is therefore relatively high. The same appears to be 

true of the Javanese rivers.

THE NILE. 1

The water of the Nile 2 has been repeatedly analyzed, with varying 

results. The best data are as follows:

1 An important memoir by A. Lucas (The chemistry of the River Nile: Survey Dept. Paper No. 12, 

Ministry of Finance, Egypt, 1908) contains much chemical matter in addition to the analyses cited here. 

A.Ch61u(Le Nil, le Soudan, 1'Egypte, Paris, 1891) gives some very questionable analyses of the Blue Nile, 

the White Nile, and the Nile near Cairo. According to Chdlu the river carries past Cairo annually 51,428,500 

metric tons of suspended solids and 20,772,400 metric tons in solution. On nitrates in the Nile see A. Muntz, 

Compt. Kend., vol. 107,1888, p. 231.

2 Analyses of the pther great African rivers seem to be lacking. For the Che'lif and references to some 

smaller Algerian streams see p. 68 of this bulletin.
LAKES AND RIVERS. 105

Analyses of ivater from the Nile.

A. The Victoria Nyanza. Analysis by 0. Chadwick and B. -Blount, Minutes of Tree. Inst. Civil Eng., 

vol. 56, p. 39,1904.

B. The White Nile near Khartoum. Average of three analyses.

C. The Blue Nile. Average of three analyses. Analyses B and C by "W. Beam, Second Kept. Well-, 

come Research Lab., Khartoum, 190C.

D. Average of 12 analyses of monthly samples, taken from the lower Nile between June 8, 1874, and 

May 13,1875. Analyses by H. Letheby, cited by S. Baker in Proc. Inst. Civil Eng., vol. CO, 1880, p. 370. 

The total solids contained 10.36 per cent of organic matter.

E. The Nile, about two hours' journey below Cairo. Analysis by 0. Popp, Liebig's Annalen, vol. 155, 

1870, p. 344. The total solids contained 12.02 per cent of organic matter.

C03 .. ................................

S04 .... .................................

Cl.... ................................

NO

PO

Ca.... ............. ....................

Me

Na.. ..................................

K.. ....................................

Si02 .... ........... ....................

Fe203 ---- ............................

A

42.10

1.92

9.28

6.96

5.08

25.13

7.61

1.92

100. 00 

135

B

42.97'

.25

4.58

.25

9.78

3.00

17.66

6.79

14.72

100. 00 

174

C

41.74

5.62

2.19

.11

18.38

4.66

5.43

1.32

20.55

100. 00 

130

D

36.50

17.44

4.47

Trace.

Trarp

20.10

4.01

3.04

7.97

j 6.47

^

100. 00 

168

E

36.02

3.93

2.83

.59

13.31

7.39

13.14

3.26

16.88

2.65

100. 00 

119

In Letheby's analyses the excess of potassium over sodium, is very 

peculiar, and highly improbable. Numerous partial analyses of 

Nile water cited by Lucas discredit the determinations, and also 

show that the composition of the water is very variable. In the 

White Nile the proportion of sulphates is insignificant. Beam 

accounts for the latter fact by supposing the sulphates to be reduced 

to carbonates by the organic matter of the "sudd." South of the 

"sudd" the White Nile contains appreciable sulphates; after leaving 

the "sudd" it is nearly free from them.

ORGANIC MATTER IN WATERS.

Up to this point we have considered only the fixed inorganic 

matter found in natural waters; but other impurities which have 

geological significance are also present. All such waters contain 

dissolved gases, especially oxygen, nitrogen, and carbon dioxide, and 

sometimes hydrogen sulphide. The rain brings also nitric acid and 

ammonia to the soil, and so into the ground water; and organic 

substances are invariably found in it in greater or smaller quantities. 

These gases and compounds interact in a great variety of ways, and 

directly or indirectly play an important part in the decomposition 

of rocks. We have already noted the importance of carbonic acid 

as a weathering agent; we have seen in a previous chapter how dis-
106 DATA OF GEOCHEMISTRY.

solved air represents a concentration, of oxygen; but so far the 

organic matter of water has been tacitly ignored Its quantity, in 

percentages of total solids, can be computed in some cases from 

published analyses. A few of the available figures are as follows:

Percentage of organic matter in the dissolved solids of river waters.

Danube.......................... 3.25

James............ .1.............. 4.14

Maumee.......................... 4. 55

Nile.............................. 10.36

Hudson......................... 11.42

Rhine............................ 11.93

Cumberland..................... 12.08

Thames......................... 12.10

Genesee.......................... 12. 80

Amazon.......................... 15.03

Mohawk.......................... 15.34

Delaware.....................:.. 16.00

Lough Neagh.................... 16.40

Xingu........................... 20. 63

Tapajos.......................... 24.16

Plata............................ 49. 59

Negro........................... 53. 89

Uruguay......................... 59.90

The range of figures is rather wide, but the highest values represent 

tropical streams. That is, leaving artificial pollution out of account, 

waters flowing through tropical swamps carry the largest proportion 

of organic matter. Lough Neagh, in Ireland, doubtless shows the 

effects of bog water.

The organic matter is. derived from the decay of vegetable substances, and by further oxidation may be converted into carbonic 

acid and water. Its chemical constitution is not completely known, 

but it consists in part at least of a vague group of colloidal substances, whose precise nature is yet to be made out. They appear to 

possess feebly acidic properties, and have therefore received specific 

names, hu'mic, crenic, apocrenic, and ulmic acids, which terms, however, if not actually obsolete, are at least obsolescent. The salts of 

these "acids" are partly soluble and partly insoluble, and the acids 

themselves are commonly reputed to be powerful agents in the 

solution of rocks.1 The humus acids are said to decompose silicates, 2 

but the evidence is contradictory or at best inadequate. The statement, long current in chemical and geological literature, that the 

acids absorb nitrogen from rain water and the air, and silica from the 

soil, forming a series of silico-azohumic acids, rests upon the unsupported assertions of P. Thenard,3 who gives no adequate experimental 

data to sustain his views, which need not be considered further. 

The observed facts are capable of much simpler interpretation.

1 See A. A. Julien, Proc. Am. Assoc. Adv. Sci., vol. 28,1879, p. 311. On the organic matter of waters 

in Finland, see O. Aschan, Zeitschr. prakt. Geologie, vol. 15,1907, p. 56. On tlie chemical nature of the 

organic matter in soils, see 0. Schreiner and E.G. Shorey, Bull. Bur. Soils No. 74, U. S. Dept. Agr. See 

also S. Od<5n, Ark. Kem. Min. Geol., vol. 4, No. 26,1912, and S. L. Jodidi, Jour. Franklin Tnst., vol. 176, 

p. 565,1913.

2 A. Rodzyanko, Jour. Chem. Soc., vol. 62, pt. 2,1892, p. 1373. Abstract from Jour. Russ. Chem. Soc. 

vol. 22, p. 208.

3 Compt. Rend., vol. 70,1870, p. 1412.
LAKES AND RIVERS. 1Q7

A comparison of the preceding table with the analyses of river 

waters generally, will show that waters relatively high in organic 

matter are likely to be high in silica also. From this it has been 

inferred that the organic matter holds the silica in solution, although 

the connection between the two is not invariable. The rivers of 

British Guiana and the Uruguay are so far the extreme examples of 

this supposed relation, and the other tropical streams lend support to 

the view. The humus acids, however, are almost insoluble in water 

alone, but readily soluble in alkaline solutions. It appears possible, 

therefore, that the alleged relation between humus and silica is purely 

coincidental and that the alkalies in the first instance are the really 

effective solvents. There is no proof that humus acids can dissolve 

silica when alkalies are absent. As colloids they are more likely to 

precipitate silica than to bring it into solution. On oxidation, however, they yield carbonic acid, and that in aqueous solution is an 

active disintegrator of rocks.

In fact, the amount of silica in a water is quite independent of 

organic matter. Many small streams, near then- sources, especially 

if they rise from crystalline rocks, carry a large relative proportion 

of silica, although its absolute amount may be trivial. This peculiarity is shown in many of the analyses cited in the preceding pages, 

and is so marked that a water low hi salinity but relatively high in 

silica and alkalies may aknost certainly be attributed to igneous 

rather than to sedimentary surroundings. This silica is directly 

clerived from the rocks at the time of their decomposition by carbonated waters, and forms a large part of the material which is at 

first taken into solution. The seepage or ground water which afterward enters the streams is much poorer in silica, and so the proportion of the latter tends to diminish as a river flows toward the sea.

The relatively high proportion of silica in waters issuing from 

areas of granitic or granitoid rocks seems to have some significance 

with regard to early conditions of life.1 When life first appeared on 

the earth sedimentary rocks were much less conspicuous than they 

are now and the igneous rocks formed by far the greatest exposures. 

The fresh waters then were doubtless of the siliceous type and 

furnished an environment peculiarly favorable to the development of 

such organisms as built their shells or skeletons of silica. The 

modern organisms of this class include diatoms, radiolarians, some 

foraminifera, and the siliceous sponges, organisms of a very low 

order, and it is probable that their ancestors were similar in character. 

The probability seems to be very great, although certainty on such 

a subject is of course unattainable.

i See F. W. Clarkc, Jour. Washington Acad., vol. 8, 1918, p. 185.
108 DATA OF GEOCHEMISTRY.

CONTAMINATION BY HUMAN AGENCIES.

In any complete discussion of river waters account must be taken 

of contamination by human agencies. Towns and factories drain 

into the streams, and the extent of the pollution is, for our immediate purposes, best measured by the proportion of chlorine. A good 

example is furnished by the Chicago drainage canal, which empties : 

into Desplaines River and thence passes through Illinois River into 

the Mississippi. For the waters thus affected there are abundant 

data, and the sanitary analyses by the late A. W. Palmer are especially 

valuable. 1 His annual averages for 1900, representing Illinois River, 

are stated below; the percentages have been calculated by me. The 

localities are arranged in order downstream.

Chlorine in Illinois and Mississippi rivers.

Illinois River:

At Grafton. .. ................................

Mississippi River at Grafton ......................

Total 

dissolved 

solids.

Parts per 

million. 

235.3 

269.4 

245.4 

245.2 

236. 3 

234.3 

232. 6 

150.1

Chlorine.

Parti per 

million. 

23.1 

21.4 

18.7 

17.5 

14.8 

14.0 

13.1 

3.1

Per cent. 

. 9.82 

7.94 

7.62 

7.14 

6.27 

5.98 

5.63 

2.06

The decrease in the proportion of chlorine as we follow the Illinois 

downstream is most striking; but even more surprising are the data 

concerning the Mississippi a little farther south, at Alton. Here 

samples were taken 100 feet from the Illinois shore, one-fourth the 

distance across, in midstream, three-fourths over, and 100 feet from 

the Missouri shore. The figures represent averages covering periods 

of from nine months to nearly the entire year 1900.

Chlorine in Mississippi River at Alton, III.

One-fourth distance across. ........................

Total 

dissolved 

solids.

Parts per 

million. 

194.1 

182.8 

160.6 

155.0 

154.2

Chlorine.

Parts per 

million. 

7.7 

7.1 

4.4 

4.1 

3.5

Per cent. 

3.97 

3.87 

. 2.74 

2.65 

,2.27

' Chemical survey of the waters of Illinois, 1897-1902, Univ. Illinois, 1903.
LAKES AND RIVERS. 109

The influence of Illinois River on the eastern side of the Mississippi is perfectly evident. The chief cause of the- diminution of 

chlorine in the Illinois is, of course, the dilution of the water by other 

less contaminated sources of supply. In the Kankakee at Wilmington the proportion of chlorine during the same period was only 1.21 

per cent, and in Fox River it was 1.98 per cent, calculated from 

the total matter in solution, Kankakee and Fox rivers represent 

. an approximation to the normal chlorine of the region; the Illinois, 

into which they flow, shows the exaggeration produced by artificial 

means. Near the ocean the normal chlorine in fresh waters is much 

higher and the effects of pollution are less conspicuous than in inland

streams.1

GAINS AND LOSSES IN WATERS.

In fresh-water lakes and rivers the salinity is naturally low that 

is, their waters are very dilute solutions, which do not approach the 

point of saturation for even the less soluble of their constituents. 

The relatively insoluble carbonates of calcium and magnesium are 

held in solution by the excess of carbonic acid which is always 

present, and are therefore to be regarded, while dissolved, as bicarbonates. Without this solvent much of the load would be deposited, 

as indeed it is by the evaporation of percolating waters in limestone 

caves, when stalactites and stalagmites are formed. In a flowing 

river, which continually receives carbon dioxide from the air and 

from decaying vegetation, such depositions are not likely to occur, 

at least not to any notable extent; but when pools are left from an 

overflow, incrustations of solid matter may soon form. The sediments found in streams are mostly claylike in character, and rarely 

contain any conspicuous proportion of carbonates or sulphates. Living organisms, especially corals, mollusks, and some aquatic plants, 

withdraw calcium carbonate from solution; but how great their 

influence may be, relatively to an entire flow, we have no means of 

estimating. Many agencies thus combine to modify the composition of a water, but the relative magnitude of the several factors can 

hardly be determined. The waters gain and lose solid matter, but 

on the whole, as we follow a stream downward in its course, the 

gains exceed the losses. When we exclude the elements of dilution 

by tributaries and the variations in concentration between high and 

low stages of water we find that salinity generally increases until a 

river reaches the sea.

Speaking broadly, lake and river waters may be divided into two 

great classes namely, sulphate and carbonate waters, according as

1 A good summary of the relations between normal and polluted waters in the eastern and middle States 

is given by M. 0. Loighton in Water-Supply Paper U. S. Geol. Survey No. 79,1903. The subject of normal 

chlorine is considered and the classical "chlorine map" of Massachusetts is reproduced.

See also Sixth Rept. Rivers Pollution Commission, 1868, on the domestic water supply of Great Britain. 

This report contains abundant data on chlorine in waters.
110 DATA OF GEOCHEMISTRY.

carbonic or sulphuric ions predominate. The classification can be 

still further subdivided with reference to the abundance of chlorides 

or of silica, and again with regard to bases; but the two main divisions still hold. Most river waters are either carbonate or sulphate 

in type, and we have already seen how climatic considerations determine, in part at least, the chemical character of a stream. The carbonates are derived from the carbonic acid of rani or from that 

produced by organic matter, which may act either upon crystalline 

rocks directly or by solution of limestones. The sulphates originate 

in the oxidation of pyrite or by the solution of gypsum, and the 

two classes of waters are almost invariably commingled. Carbonate 

waters are by far the most common, as the cited analyses show, and 

the reasons for this fact have already been made clear. We have 

also seen how a river can change its type in flowing from one point to 

another, and we have noted the probability that this transformation is commonly due to the blending of streams, or even to the 

accession of ground waters. One other point in this connection remains to be noted namely, the possible influence of micro-organisms. 

It is more than probable that these minute creatures, acting in presence of other organic matter, may reduce sulphates, with elimination 

of hydrogen sulphide and the formation of carbonates in their stead. 

That reactions of this kind occur in saline and brackish waters seems 

to be well established.1 A suggestive instance came within the experience of the United States Geological Survey. A quantity of water 

rich in sulphates, from one of the alkaline lakes of California, was 

sent to the laboratory in a wooden barrel. When received, the 

water had become fetid with hydrogen sulphide and discolored by 

extract from the wood so much so as to be unfit for analysis. 

How far such changes may occur in nature, especially in swamp 

waters, remains to be determined. At all events, the possibility of 

similar transformations can not be ignored. That bacteria are 

active agents in precipitating calcium carbonate is well known; but 

that subject will be considered more fully in another chapter.

CHEMICAL DENUDATION.

Now, to sum up: A river is formed by the union of waters from 

many sourceSj and each one owes its peculiarities to the conditions 

existing at its starting point. Carbonic acid, either of atmospheric 

or of organic origin, is the most abundant and generally the most 

potent of the agents that dissolve mineral matter from the rocks. 

Hence carbonate waters are the commonest, and, as streams blend 

to form the great continental rivers, the carbonate type tends to

1 See N. Zolinsky, Jour. Chein. Soe., vol. 66, pt. 2,1894, abstract, p. 200; also M. W. Bcyerinck, idem, 

vol. 80, pt. 2, abstract, p. 119; an«.\K. H. Saltet and C. S. Stockvis, idem, vol. 80, pt. 2,1901, p. 265.
.' LAKES AND BIYEES. Ill

become more and more pronounced. In the temperate zone, at 

least, the larger streams resemble one another chemically, and seem 

on the average to do pretty much, the same chemical work in pretty 

much the same way. The composition of their waters gives a measure, of the effects which they have produced; and if the data were 

adequate the study of chemical denudation would be both profitable 

and easy. But the data are not adequate, except for certain areas, 

and therefore any estimate which may be reached as to the quantity 

of solid matter annually carried in solution by rivers to the sea 

must be subject to future revision. It is clear that an analysis of 

river water, taken at a single point and at one stage of concentration, tells us little or nothing of what the stream as a whole may do. 

Annual averages of water taken near the mouths of rivers are needed 

before the problems of chemical denudation can be even approximately solved.

For example, Sir John Murray * has computed,, by averaging the 

analyses of 19 rivers, not only the total amount of saline matter 

carried annually to the ocean, but also its composition. But his 

estimate,, published in 1887, was based almost necessarily upon European data and to a large extent upon inconclusive analyses. Evidence as to the chemical character of the greater American, African, 

and Asiatic streams was then practically unobtainable, and therefore 

the computation was only a rough indication of what the truth may 

be. Data from all the greater river basins of the world are required 

before we can determine the full significance of chemical denudation.

The problem, however, is not entirely hopeless. It can be attacked 

locally, with reference to specific areas, and a fairly probable approximation to the truth can be made from the evidence which now exists. 

T. Mellard Reade, 2 for instance, in a well-known investigation, has 

calculated the amount of solid matter annually dissolved by wate? 

from the rocks of England and Wales. Putting the average salinity 

of the waters at 12.23 parts in 100,000, he estimates that the total 

annual run-off from the area in question carries in solution 8,370,630 

tons of dissolved mineral matter, or 143.5 tons from each square mile 

of surface. At this rate, by the solvent action of water alone, the 

level of England and Wales would be lowered 1 foot in 12,078 years. 

Reade also, from such data as he could obtain, for the most part single 

analyses, made similar but rough estimates for several European 

river basins, which, in British tons per square mile, may be tabulated 

as follows:

Rhone.............................. 232

Thames............................. 149

Garonne--...-............-.....___.. 142

Seine............................... 97

Rhine............................ 92.3

Danube............................ 72. 7

1 Scottish Geog. Mag., vol. 3,18S7, p. 65-.

2 Proc. Liverpool Geol. £oc., vol. 3,1876-77, p. 211. Reprinted under the title "Chemical denudation iu 

relation to geological time."
112 DATA OF GEOCHEMISTRY.

The average for the entire land surface of the globe he put at 100 

tons per square mile, a figure that was not much better than a guess.1

From investigations made in the water-resources branch of the 

United States Geological Survey, lower figures are obtained. By 

combining the results of careful river gaging with the data for salinity 

as determined in the laboratory, R. B. Dole and H. Stabler 2 have 

deduced a table, of which the following is an abridgment. The 

Great Basin and the Red River of the North are here left out of 

account.

Chemical denudation in the United States.

Drainage area.

Eastern Gulf of Mexico. ....:............................

South Pacific. ...........................................

"NT /ivf*!"! "Po fi "fi **»

Total.. . .........................................

Area drained 

(square miles).

] 59, 400

123, 900

149 "100

315, 700

1, 265, 000

175, 000

230, 000

79 700

270, 000

2, 753, 800

Dissolved solids 

(tons per square 

mile).

i^n

f)4

117

36 1AQ'

116

Cl

177

100

«98

o Short tons of 2,000 pounds. The metric ton equals 2,205 pounds.

For the entire United States, 3,088,5.00 square miles, regarding 

the denudation of the Great Basin as zero that is, as not contributory to the ocean the average denudation is estimated by Dole 

and Stabler as 87 short tons, or 78.9 metric tons per square mile, a 

figure which is not likely to be much changed by future investigations. 

It refers, however, only to inorganic matter. If organic impurities 

are included it should be increased by perhaps 10 per cent; that is, 

to 86.8 metric tons per square mile. The variation in the denudation 

factors assigned to the several areas is quite important. The Colorado drains an arid region, and much of the area ascribed to the 

river adds little or nothing to it. The humid basin of the St. Lawrence, on the other hand, is a liberal contributor of saline substances. 

The Mississippi, with humid regions to the east and semiarid plains 

to the west, shows an intermediate figure for the chemical erosion.

1 For other estimates of the amount of material carried by various rivers, see A. Geikie, Text-book of 

geology, 4th ed., vol. 1,1903, p. 489. The Thames, for example, carries in solution past Kingston 548,230 

tons of fixed inorganic matter in a year. See also the thesis of A. F. White on the waters of Rockbridge 

County, Virginia (Washington and Lee Univ., 1906). This thesis deals with North River, a tributary of 

the James.

2 Water-Supply Paper U. S. Geol. Survey No. 234, 1909, p. 78. The figures are given in much greater 

detail than is practicable here. Some of the areas, etc., differ slightly from those cited in previous pages 

of this book; but the differences are trivial and do not appreciably affect the final result. The more recent 

data relative to Columbia River, Alaskan rivers, etc., are not included in this estimate.
LAKES AND RIVERS.. 113

For the rest of North America only a rough estimate is possible. 

The analyses of Canadian rivers and also of the Yukon given in previous pages indicate an average composition and salinity much like 

that of the St. Lawrence. For Mexican and Central American rivers 

no data are at hand, but it is probable that for northern Mexico, at 

least, they would resemble those of Texas, New Mexico, and Arizona. 

That is, the waters north of the United States and south of it vary 

from the mean found for the United States in opposite directions, 

and so tend to balance each other. In short, the average for the 

United States probably represents fairly'well the average for the 

entire- continent. If we assume that six millions of square miles in 

North. America lose 79 metric tons in solution per square mile per 

annum, and that the composition of the saline matter so transported 

is that found for the United States alone, we shall be fairly near the 

truth.

Evidence for South America is very scanty. On the basis of 

Frankland's analysis, Reade 1 estimates the denudation factor of 

the Amazon at 50 tons per square mile. Using the same analysis, 

and Murray's estimate of the total run-off, I find that 53 tons is 

rather more probable. Similar estimates for the Uruguay and the 

Negro give a factor of 50 tons. About four millions of square miles 

in South America may be assigned the latter figure, with a reasonable 

degree of probability. The Amazon dominates the entire combination, and its low salinity is due to the fact that it drains a vast tropical 

forest, which is thoroughly leached. Through much of its course it 

has scanty access to fresh rocks and therefore finds but little material 

to dissolve. Large areas in South America, like western Peru and 

central Argentina, contribute nothing to the ocean and count for zero 

in measuring chemical denudation.2

Some figures relative to European waters have already been given. 

According to Geikie the Thames carries in solution past Kingston 

548,230 British or 556,930 metric tons of inorganic matter annually. 

The drainage area is 6,100 square miles, hence a denudation factor 

of 91.3 metric tons per square mile. For the Meuse above Liege 

the figures published by Spring and Prost give a factor of 139 tons. 

In Sweden the chemical denudation is much smaller, but seems to 

have been estimated for only a very limited area. Reade's estimate 

for all Europe is 100 tons per square mile, and that seems to be 

fairly probable. For Europe, then, I shall assume that 3,000,000 

square miles suffer solvent denudation at the rate of 100 tons per 

mile, a figure which is not far from that assigned to the Laurentian 

Basin. Europe is generally well watered, and its waters have all the

i Evolution of earth structures, London, 1903, pp. 255-282.

a The rivers of British Guiana arc not included in this discussion, which was completed before their 

analyses were made.

113750° 19 Bull. 695 8
114 DATA OF GEOCHEMISTRY.

characteristics of those from the humid areas of the United States. 

In the latter the denudation factor is lowered by the arid regions ofthe Southwest.

The African material is very imperfect. According to Chelu, 1 the 

Nile carries 20,772,400 metric tons in solution annually. This, for 

an ostensible drainage basin of 1,293,050 square miles, gives a denudation factor of only 16 tons. Much of northern Africa resembles 

the Valley of the Nile so far as denudation is concerned. We may 

safely assume that 1,500,000 square miles are represented by the 

Nile, and also that 6,500,000 are equivalent in character to South 

America with its tropical streams. The desert regions, like the 

Sahara, of course, are negligible.

The data relative to Asiatic waters are even more defective. The 

water of Lake Baikal resembles that of the St. Lawrence, while the 

Mahanuddy has the peculiarities of tropical rivers. With these 

feeble clues I can only make a very rough estimate for Asia, as 

follows: Assume 3,000,000 square miles to average like Europe, 

3,000,000 like the United States, and 1,000,000 like South America, 

Large areas in Asia are obviously left out of consideration the 

Caspian depression, the central deserts, and the Arabian peninsula. 

The streams reaching the sea from Arabia are too small to carry 

any weight in the general discussion.

To sum up, the crude figures for chemical denudation are as 

follows:

North America... .6,000,000 square miles at 79 tons..... .474,000,000 tons

South America... .4,000,000 square miles at 50 tons..... .200,000,000 tons

Europe............3,000,000 square miles at 100 tons..... .300,000,000 tons .

Asia...............7,000,000 square miles at 84 tons..... .588,000,000 tons

Africa............ 8,000,000 square miles at 44 tons...... 352,000,000 tons

28,000,000 square miles at 68. 4 tons,... .1,914,000,000 tons

The incompleteness of the foregoing figures is due to the fact that 

large areas of land either do not drain into the ocean, or add little or 

nothing to it. The total land area to be considered that is, .the 

area which contributes to the salinity of the ocean is, according to 

Murray, 39,697,400 square miles, or, in round numbers, 40,000,000. 

Assuming that the figures so far given represent a fair average, the 

amount of saline matter carried into the ocean by the river drainage 

of the world is 2,735,000,000 metric tons annually, an estimate only 

a little more than half that given by Murray.2 The rivers studied by 

Murray must have been for the most part, if not exclusively, in the 

Temperate Zone, where alternations of freezing and thawing tend to 

break up the rocks and so to render them more easily decomposed

' i Le Nil, Ic Soudan, PlLgypte, Paris, 1891.

2 For more details with reference to these computations, see F. W. Clarke, A preliminary study of chemical denudation: Smithsonian Misc. Coll., vol. 56, No. 5,1910. :
LAKES AND RIVERS. 115

by percolating waters. With even moderate humidity the activity 

of the waters is great, and large amounts of material are transported 

by them. On the other hand, Arctic rivers flow to a noteworthy 

extent over tundra, which is frozen during the greater part of the 

year. They therefore have comparatively small influence in rock 

solution, and much of their flow must be mere surface run-off. The 

low salinity of tropical streams has already been noted. The total 

amount of chemical denudation depends upon the balancing of these 

varying tendencies.

With the aid of the foregoing estimates, and of the analyses cited 

in this chapter, a probable average can be computed for the composition of the fresh waters of the globe. Such an average is shown in 

the next table.

Average composition of river and lake ivaters.

A. Waters of North America. Average computed from the data given by Dole in Water-Supply Paper 

230, and by Dole and Stabler in Water-Supply Paper 234. Each analysis is weighted proportionately to 

the total amount of material annually carried by theriver. The alkalies arc given with Palmer's determinations of potassium.

J.i. Waters of South America. Average made up from the cited analyses, weighted as follows: Amazon, 

12; Uruguay, 1; Negro, 1; all smaller streams, 2. The Eio do la Plata is left out of account, for the analyses 

are not conclusive. 

G. Waters of Europe. Average of 300 analyses of river and lake waters, first by groups, and then weighting each group proportionately to its drainage area.

D. Waters of Asia. Made up of the averages A, B, C, weighted 3:3:1 as explained in a previous paragraph.

E. Waters of Africa. Made up of the average for the Nile and that for South America as already described.

F. General average, in wluch each of the foregoing averages is weighted proportionally to the number of 

tons given in the preceding table.

G. Sir John Murray's average composition of river water (Scottish Geog. Mag., vol. 3, 1SS7, p. 65), reduced to the uniform standard adopted in this book. Organic matter as given by Murray is 10.37 per cent 

of the total solids.

C03 .................

so / CLV::::::::::::::::: "WO

Ca. .................

Mg.. ................

Na...................

K. ..................

(Fe,Al)A--. --------

Si02 .... ..............

Minor constituents. . .

Weight. ..............

A

33.40

15.31

7.44

1.15

19.36

4.87

7.46

1.77

.64

8.60

100. 00 

10

B

32.48

8.04

5.75

.62

18.92

2.59

5.03

1.95

5.74

18.88

100. 00

4

c

39.98

11.97

3.44

.90

23.19

2.35

4.32

2.75

2.40

8.70

100. 00 

6

D

36.61

13.03

5.30

.98

21.23

3.42

5.98

1.98

1.96

Q SI

100. 0011

E

32.75

8.67

5.66

.58

19.00

2.68

4.90

2.35

5.52

17 CQ

100. 00

7

F

35.15

12.14

5.68

.90

20.39

3.41

5.79

2.12

2.75

11.67

100. 00

G

41. 33

8.22

1.85

2.82

20. 46

4.65

3.47

1.33

4.76

10.75

.36

100. 00

The general mean F, regardless of corrections to be considered later, 

is curiously near the average figures for three great rivers, the Mississippi, the Amazon, and the Nile. It may be too high in silica, but 

on the whole it is as near the truth as can be determined with existing 

data. Analyses of the greater rivers of Asia and Africa may modify
116 DATA OF GEOCHEMISTBY.

it slightly, but the order of magnitudes shown by the several radicles 

is- not likely to be changed.

Recurring now to Reade's estimate of chemical denudation in England and Wales, a rate of one foot in 12,978 years, the new data may 

be applied to a similar discussion for the entire land surface of the 

globe. For the United States, excluding the Great Basin, the denudation factor of 79 tons per square mile per annum gives for a lowering of 1 foot 23,984 years. For South America the figures are 50 

tons and 37,896 years; for Europe, 100 tons and 18,948 years, and for 

the Nile Valley, 16 tons and 118,424 years. For the entire 40,000,000 

square miles of land the average values are 68.4 tons and 27,700 years; 

estimates that are subject to corrections of a kind which Reade did not 

take into consideration.

On critical examination of the data it is clear that the total apparent amount of solvent denudation is not a true measure of rock 

decomposition. In the general mean of all the river analyses now 

under discussion, 0.90 per cent of NO3 and 35.15 per cent of C03 

appear. The N03 came entirely or practically so from atmospheric 

sources; the C03 was derived partly from the atmosphere and partly 

from the solution of limestones. Dealing now only with the existing 

discharge of rivers, we must subtract these atmospheric additions 

from the total annual load of dissolved inorganic matter before we 

can compute the real amount of rock denudation.

The land surface of the earth is covered, nearly enough for present 

purposes, by 75 per cent of sedimentary and 25 per cent of igneous 

and crystalline rocks; * and it is on or near this surface that the flowing waters act. The limestones, as shown in Chapter I, constitute 

only one-twentieth of the sediments, or 3.75 percent of the entire 

area, but the proportion of carbonates derived from them must be 

very much larger. The composite and average analyses of rocks 

give, for lime, 4.81 per cent in the igneous, and 5.42 in all the sedimentaries, equivalent to 3.78 and 4.26 per cent of CO2 respectively. 

Assuming that all the surface rocks yield-lime at an equal rate, which 

is obviously not quite true, and multiplying these figures by the areas 

represented as 1 to 3, the relative proportions of the C03 radicle 

become 3.78:12.78,or 1:3.4 nearly. The last figure should be higher, 

because of the more rapid solution of the limestone, but if we accept 

the ratio as it stands we may use it to determine the approximate 

proportions of the C03 radicle derived from limestones and from the 

atmosphere acting upon crystalline rocks. On this basis, 8 per cent 

of C03 should be deducted from the percentage in the river waters, 

together with the 0.9 per cent of N03 . Making the subtraction from 

the total river load of dissolved matter, 2,735,000,000 tons, there 

remains 2,491,585,000 tons, or about 62:3 tons per square mile on the

i Estimate by A. von Tillo, actually 75.7 and-24.3.
LAKESS AND RIVERS. 117

average, for the 40,000,000 of square miles of land which are assumed 

to drain into the ocean. This implies a lowering of the land by solvent 

denudation at the rate of one foot in 30,414 years, or 30,000 in round 

numbers. The last estimate may be subject to large future corrections, but probably it is correct within 10 per cent. There are, 

for example, corrections for the amount of chlorine and its equivalent 

sodium brought in rainfall from the atmosphere, or by sewage from 

towns.1 These will be considered in the next chapter in relation to 

the use of the data in measuring geologic time.

1 Spring and Prost, in their work on the Meuse, and Ullik, in his study of the Kibe, have attempted to 

measure the amount of human contamination. This, obviously, must be very variable. In rivers liko 

the Yukon or the Colorado it is negligible; in the Mississippi or the Hudson it is doubtless large. In small 

streams in thickly settled manufacturing districts theamount of pollution is often enormous.
CHAPTER IV. 

THE OCEAN.

ELEMENTS IN THE OCEAN.

For obvious reasons, some of them purely scientific and some 

utilitarian, the water of the ocean has been the subject of long and 

elaborate scientific investigations. Considered broadly, its composition is relatively simple and remarkably uniform; studied minutely, 

it is found to contain many substances.1

In his great memoir on the chemical composition of sea water, G. 

Forchhammer 2 gave a list of the various elements which, up to his 

time, had been detected in it. The elements which are sufficiently 

abundant to be determined in ordinary analyses will be considered 

later; the substances that are less frequently estimated may be 

briefly considered now.

Iodine. Chiefly found in the ashes of seaweeds. According to E. 

Sonstadt,3 it is present in sea water in the form of calcium iodate. 

The quantity estimated was one part of this salt in 250,000 of water, 

equivalent to about two parts per million of iodine. A. Gautier,4 

examining surface water from the,Mediterranean, found iodine only 

in the organic matter which he separated by filtration, but at depths 

beyond 800 meters its compounds were detected in the water itself. 

Living organisms withdraw iodine from solution. The largest 

amount of iodine, organic and inorganic, reported by Gautier, is 

2.38 milligrams to the liter. J. Koettstorfer,5 in an earlier investigation, found only 0.02 milligram, and L. W. Winkler 6 only 0.05 

milligram per liter.

Fluorine. Found directly and also in the boiler scale of oceanic 

steamers. A. Carnot's determinations 7 show that the water of the 

Atlantic contains 0.822 gram of fluorine to.the cubic meter.8 Recent 

determinations by A. Gautier and P. Clausmann 9 gave only 0.3 milligram per liter. P. Carles 10 has reported fluorine in the shells of 

mollusks.

1 For the volume of the ocean and of its contained salts see pp. 22-24.

2 Philos. Trans., vol. 155,1S05, pp. 203-262. See also J. Roth, Allgemcine und chemische Geologic, vol. 1, 

1879, p. 400; and W. Dittmar, Kept. Challenger Expcd., Physics and chemistry, vol. 1, 1884, pp. 1-251. 

A volume by Ren<5 Q.uinton (L'eau de incr, Paris, 1904) contains (pp. 221-235) a good summary of earlier 

work on the less important elements in sea water. The book is essentially biochemical in character and 

deals mainly with the relations of sea water to life.

3 Chem. News, vol. 25,1872; pp. 19C, 231, 241; vol. 74,1890, p. 310. 

'Compt. Rend., vol. 128, 1899, p. 10G9; vol. 129, 1899, p. 9. 

6 Zeitschr. anal. Chemie, vol. 17,1878, p. 305. . 

e Zeitschr. angew. Chemie, vol. 29, pt. 1,1910, p. 205. 

 ' Annales des mines, 9th ser., vol. 10,1890, p. 175.

s See also earlier determinations by G. Forchhammer and G. Wilson, Edinburgh New Philos. Jour., 

vol. 48,1850, p. 345.

9 Compt. Rend., vol. 158,1914, p. 1031.

10 Idem, vol. 141,1907, pp. 437,1240.

118
THE OCEAN. 119

Nitrogen. Present as ammonia, in organic matter, and in dissolved 

air. The ammonia of sea water has been repeatedly investigated. 

A. Audoynaud,1 in water from the coast of France, found 0.16 to 1.22 

milligrams of NH3 per liter. L. Dieulafait,2 in waters from the Red 

Sea and the coast of Asia, reports quantities from 0.136 to 0.340 

milligram. T. Schloesing 3 found a still larger amount, namely, 0.4 

milligram. According to J. Murray and R,. Irvine,4 ammonia is 

more abundant around coral reefs than in the North Atlantic or 

German Ocean. It occurs principally as ammonium carbonate, 

formed by the decomposition of organic matter. Elaborate determinations of ammonia in the Mediterranean are given by K. Natterer.5

Phosphorus. Present in the form of phosphates. The phosphatic 

nodules found on the bottom of the sea are considered farther on in 

this chapter.

Arsenic. Detected by Daubre*e. A. Gautier °'found its quantity to 

range from 0.01 to 0.08 milligram per liter.

Silicon. According to J. Murray and R. Irvine, 7 sea water contains silica. The proportion is from 1 part in 220,000 to 1 in 460,000, 

or even less. The siliceous organisms which abound in the ocean 

possibly take their silica from clayey matter in mechanical suspension. Small amounts of such matter are carried far and wide 

by currents, often to a great distance from land. E. Raben 8 found 

sea water to contain from 0.2 to 1.4 milligrams of silica per liter.

Boron. Present in sea water and in the ashes of marine plants. 

J. A. Veatch,0 who examined water from the coast of California, 

found boric acid almost exclusively in samples collected over a submarine ridge, parallel with the land but 30 to 40 miles away. He 

suggests for it a volcanic origin from submerged sources.

Lithium. Reported in sea water by L. Dieulafait. 10 Also detected 

spectroscopically by G. Bizio in water from the Adriatic.

Rubidium. Found in sea water by Sonstadt. 11 Determined quantitatively by Schmidt, whose analyses will be cited later.

Csesium. Also found by Sonstadt. 11

1 Cornpt. Rend, vol. 81,1875, p. 619.

2 Annalcs cliim. phys., 5th ser., vol. 14, 1878, p. 380. Dieulafait mentions earlier work by Marchand 

and Boussingault.

s Contributions a 1'etude de la chimic agricolc, in Fremy's Encyclopedic chimiquc, 1888.

* Proc. Roy. Soc. Edinburgh, vol. 17,1889, p. 89.

. c Monatsh. Chemie, vol. 14,1893, p. 075; vol. 15,189-1, p. 5%; vol. 1C, 1895, p. 591; vol. 20,1899, p. 1. See 

also. E. Rabcn, Wissenschaftliche Mceresuntersuchungen, vol. 11, Kiel, 1910, p. 303. Many determinations are given, also a full summary of earlier work.

6 Compt. Rend., vol. 137,1903, pp. 232, 374.

' Proc. Roy. Soc. Edinburgh, vol. 18,1891, p. 229.

8 Wissenschaftliche Meeresuntersuchungen, vol. 11, Kiel, 1910, p. 311.

9 Proc. California Acad. Sci., vol. 2,1859, p. 7.

1 ' Annales chim. phys., 5th ser., vol. 17, 1879, p. 377. See also Thorpo and Morion's analysis of water 

.from the Irish Sea, 1871, cited on p. 123. 

» Chem. News., vol. 22,1870, p. 25.
120 DATA OF GEOCHEMISTRY.

Barium arid strontium. Can be detected by ordinary methods. 

Also found in the ashes of seaweeds and in boiler scale. 1

Aluminum and iron. Easily detected by direct methods.

Manganese. Easily detected. Noted by Forchhammer and also 

by Dieulafait.2 Concretions of manganese oxide are abundant over 

portions of the sea bottom. Reported by E.° Maumene" 3 in the 

ashes of Fucus serratus.

Nickel and cobalt. Found in the ashes of marine plants.

Copper. Repeatedly detected in sea water, especially by Dieulafait.4 Also in the ashes of seaweeds and in certain corals.

Zinc. Reported in sea water by Dieulafait.5 Also found in the 

ashes of seaweeds.

Lead. Found by Forchhammer in a coral.

Silver. Repeatedly observed. Forchhammer, in the coral above 

noted, found one part of silver to eight of lead. Malaguti, Durocher, 

and Sarzeaud 6 found silver to the amount of 0.5 milligram in 50 

liters of water and detected copper and lead. According to A. 

Liversidge, 7 silver is present in sea water to the extent of 1 to 2 

grains per ton.

Gold. The fact that sea water contains gold was first established 

by E. Sonstadt 8 in 1872. Its presence has since been repeatedly 

verified. In 1892 C. A. Minister 9 examined water from the Kristiania Fjord, Norway, and found in it 5 to 6 milligrams of gold, with 

19 to 20 of silver, per ton. In each analysis he used 100 liters of 

water. Liversidge 10 found the gold in Australian waters to range 

from 0.5 to 1.0 grain per ton. At either rate, gold is present in the 

ocean in thousands, of millions of tons. Liversidge " also detected 

gold in kelp, rock salt, and a number of saline minerals, such as 

sylvine, kainite, carnallite, and Chilean niter. In one sample of 

kelp he found 22 grains of gold per ton, and in a bittern 5.08 grains. 

J. R. Don 12 examined both ocean water and oceanic sediments. In 

the former he detected 0.071 grain of gold per metric ton, but the 

sediments were barren. In waters collected near the Bay of San 

Francisco L. Wagoner 13 found, also per metric ton, 11.1 milligrams

1 On strontium in sea water see Dieulafait, Compt. Rend., vol. 84,1877, p. 1303.

2 Idem, vol. 96,1883, p. 718.

3 Idem, vol. 98,1884, p. 1417.

4 Annales chim. phys., 5th ser., vol. IS, 1879, p. 359. 

« Idem, vol. 21,1880, p. 266. 

«Idem, 3d ser., vol. 28,1850, p. 129.

' Proc. Roy. Soc. New South Wales, vol. 29,1895, pp. 335, 350. See also F. Field, Proc. Roy. Soc., vol. 8, 

1856, p. 292.

8 Chem. News, vol. 26,1872, p. 159.

6 Jour. Soc. Chem. Ind., vol. 11, 1892, p. 351. From Norsk Tekn. Tidsskr. 

1° Proc. Roy. Soc. New South Wales, vol. 29, 1895, pp. 335, 350.

11 Jour. Chem. Soc., vol. 71, 1897, p. 298.

12 Trans. Am. Inst. Min. Eng., vol. 27, 1897, p. 615. 

i 8 Idem, vol. 31, 1901, p. 807:
THE OCEAN. 121

of gold and 169.5 of silver. In a later paper he gives larger figures, 

namely, 16 milligrams of° gold and 1.9 grams of silver. According 

to J. W. Pack * sea water contains about 0.5 grain of gold per ton. 

In deep-sea dredgings Wagoner 2 detected even larger quantities of 

both precious metals.

Radium. Ocean water, sea salt, and oceanic sediments are all 

more or less radioactive. From measurements of this radioactivity 

the amount of radium is inferred. 3 According to Joly, 1 cubic 

centimeter of sea water on the average contains 0.017X10"12 gram 

of radium. This represents a total of about 20,000 metric tons of' 

radium in the entire ocean. But is this radioactivity due solely to 

radium ?

COMPOSITION OF OCEANIC SALTS.

In order to determine the composition of ocean salts, innumerable 

analyses have been made, representing water collected in all quarters 

of the globe. The older investigations, down to and including the 

work of Forchhammer, are well summarized by Roth, and it is not 

necessary to recapitulate them here. With a few exceptions, I shall 

confine myself to the- more recent analyses, which are numerous 

enough and varied enough for all present purposes. They show a 

striking uniformity in the composition of sea salts, the only great 

variable being that of concentration. As this factor is large, compared with the salinity of lakes and rivers, I shall express it generally 

in percentages rather than in parts per million. The analyses themselves I have reduced to ionic form, ignoring bicarbonates, as in the 

tables given in the preceding chapter. The selected data are as 

follows. 4

1 Min. and Sci. Press, vol. 77,1898, p. 154.

2 Trans. Am. lost. Min. Eng., vol. 38,1907, p. 704. P. De Wilde (Arch. sci. phys. nat., 4th ser., vol. 19, 

1905, p. 559) and A. Wiesler (Zeitschr. angew. Chomie, 1908, p. 1795) have published good summaries 

relative to the detection of gold in sea water and have discussed the possibility of its economic recovery.

8 See R. J. Strutt, Proc. Roy. Soc., vol. 78A, 1907, p. 151; A. S. Eve, Philps. Mag., 6th ser., vol. IS, 1909,

^p. 102; J. Joly, idem, vol. 15,190S, p. 385; vol. 18,1909, p. 396. In a volume entitled "Radioactivity and

geology,'' London, 1909, pp. 45-58, Joly sums up the relations of the ocean to radium. Sec also S. J. Lloyd,

Am. Jour. Sci., 4th ser., vol. 39, 1915, p. 580. His estimate of radium in sea water is only 1.2X10-12 gram

per liter, or 1,400 tons in the ocean.

* Other analyses of Atlantic water, taken off the coast of Brazil, with analyses of water from the mouths 

of the Amazon, are given by F. Katzer, in Sitzungsb. K. bohm. Gcscll. Wiss., 1897, No. 17. These represent mixtures of sea and river water. For special determinations of bromine in sea water and its ratio to 

the chlorine see E. Bcrglund, Ber. Deutsch. chem. Gescll., vol. 18, 1885, p. 2S88. An analysis of water 

from the Ionian Sea, by F. Wibel, is printed in Ber. Deutsch. chem. Gesell., vol. 6,1873, p. 184. One by 

A. Vicrthaler (Sitzungsb. K. Akad. Wiss. Wien, vol. 56,1867, p. 479), of Adriatic water taken near Spalato, 

shows abnormally low sodium and high calcium, presumably due to admixtures of water from the land. 

See also W. Skey, Third Ann. Rept. Colonial Mus. and Lab., New Zealand, 1868, for seven analyses of 

sea water taken near that island; C. J. White, Proc. Roy. Soc. New South Wales, vol. 41,1907, p. 55, one 

analysis of water taken off Coogee; A. Burada, Ann. sci. Univ. Jassy, vol. 5, 1909, p. 251, one analysis of 

water from the Black Sea. On salinity of the Persian Gulf, Annalen d. Hydrographie, vol. 7, 1908, p, 

293. Two recent analyses of Adriatic water are reported by V. Gegenbauer, Min. pet. Mitt., vol. 29,1910, 

p. 357.
122 DATA OF GEOCHEMISTRY.

Analyses of oceanic salts.

A. Mean of 77 analyses of ocean water from many localities, collected by the Challenger expedition, 

W. Dittmar, analyst. Challenger Rept., Physics and chemistry, vol. 1, 1884, p. 203. Salinity, 3.301 to 

3.737 percent.

B. Atlantic water, mean of 22 samples collected on a voyage from the Cape of Good Hope to England. 

C. J. S. Makin, Chern. News, vol. 77,1898, pp. 155,171. Salinity, average, 3.631 per cent.

C. The Atlantic near Dieppe. Analysis by T. Schloesing, Compt. Rend., vol. 142, 1900, p. 320. 

Salinity, 32.420 grams per liter.

T). The Irish Sea. Analysis by T. E. Thorpe and E. H. Morton, Liebig's Annalen, vol. 158, 1871, 

p. 122. The small amounts of Fe203, NIT3, and N2 05 are here added together. A trace of lithium was 

also reported.

E. The Baltic Sea between Ocland and Gothland. Analysis by C. Schmidt, Bull. Acad. St. Petersburg, 

vol. 24, 1878, p. 231. In all Schmidt;s analyses the bicarbonates given by him have been here reduced 

to normal salts. The quantities of Fe, P0<, and Si02 found by Schmidt arc so small that I have added 

them together. Salinity of this sample, 0.7215 per cent.

F. The Atlantic at Bahia Blanca, coast of Argentina. Mean of two samples, taken at low and high 

tide. Analyses by E. H. Ducloux, An. Soc. cicnt. Argentina, vol. 54, 1902, p. 62. Salinity, 3.365 per 

cent. Another pair of analyses is given of water taken at the mouth of Rio Negro.

G. The Gulf of Mexico, off Loggerhead Key, near Florida. Analysis by G. Steiger, laboratory of the 

U. S. Geological Survey, 1910. Salinity, 3.549 per cent.

H. From near Beaufort, North Carolina. Mean of five analyses of samples taken under varying 

conditions, by A. S. Wheeler, Jour. Am. Chem. Soc., vol. 32,1910, p. 646. Salinity, 3.179 to 3.607 per cent. 

Wheeler cites an analysis by C. Herbst of Mediterranean water.

I. The north Atlantic between Norway, the Faroe Islands, and Iceland, and northward to Spitzbergen. 

Mean of 51 incomplete analyses by L. Schmelck, Den Norske Nordhavs-Expedition, pt. 9, 1882, p. 1. 

Soda and carbonic acid estimated by calculation, not directly determined. Salinity, 3.37 to 3.56 per cent.

J. The White Sea. Average of three analyses by C. Schmidt. Bull. Acad. St. Petersburg, vol. 24,1878, 

p. 231. Salinity, 2.598 to 2.968 per cent.

K. The Arctic Ocean between the White Sea and Nova Zcmbla. Mean of two analyses by Schmidt, 

loc. cit.

L. The Siberian Ocean. Water collected by the Vega expedition. Mean of four analyses by ForsbergF 

Vega Exped. Rept., vol. 2, 1883, p. 370. Salinity, 1.378 to 3.457 per cent.

M. The Mediterranean near Carthage. Analysis by T. Schloesing, Compt. Rend., vol. 142,1906, p. 320. 

Salinity, 38.9744 grams per liter.

N. The Mediterranean, niidsea, between Bizerta and Marseille. Salinity, 38.789 grams per liter. 

Analysis by Schloesing, loc. cit.

0. The eastern Mediterranean, waters collected during the voyages of the 'Austrian steamer Pola. 

Analyst, K. Natterer, Monatsh. Chemie, vol. 13,1892, pp. 873, 897; vol. 14,1893, p. 624; vol. 15, 1894, p. 530- 

Three hundred samples of water were examined, some only for gases. .The figures given here are the 

average from 42 analyses which were fairly complete. Salinity, 3.836 to 4.115 per cent.

P. The Sea of Marmora. Natterer, Monatsh. Chemie, vol. 16,1895, p. <05; 44 partial analyses. Natterer 

gives the figures here utilized as averages of varying numbers of determinations. Mg, Na, and K not 

determined. Salinity, 2.310 to 4.061 per cent.

Q. The Black Sea. Average of six analyses by S. Kolotoff, Jour. Russ. Phys. Chem. Soc., vol. 2.1,1893, 

p. 82. Salinity, 1.820 to 2.223 per cent.

R. The Suez Canal at Ismailia. Analysis by C. Schmidt, Bull. Acad. St. Petersburg, vol. 24,1878, p. 231. 

Salinity, 5.103 per cent. For other data on the Suez Canal, see L. Durand-Clayc, Annales chim. phys., 

5th ser., vol. 3,1874, p. 188. Very high salinities were noted. For a recent, incomplete analysis of Red 

Sea water, see J. B. Coppock, Chem. News, vol. 96,1907, p. 212.

S. The Red Sea near the middle. Analysis by Schmidt, loc. cit. Salinity, 3.976 per cent.

T. The Red Sea. Average of four analyses by Natterer, Monatsh. Chemie, vol. 20, 1S99, p. 1; vol. 21, 

1900, p. 1037. Water collected in the Suez Canal, the Timsah Lake, and the two Bitter Lakes. Many 

other partial analyses are given. The salinity of these particular samples ranged from 5.085 to 0.854 per cent.

U. The Straits of Malacca. Salinity, 2.7965 per cent.

V. The China Sea. Salinity, 3.208 per cent.

W. The Indian Ocean, mean of two analyses, salinity 3.5534 to 3.6681 per cent. Analyses U, V, W, by 

C. Schmidt, Mel. phys. chem., vol. 10, p. 594. Also Jahresb. Chemie, 1877, p. 1370. Schmidt's rubidium 

determinations need verification.

X. The "Mare Morto," an inclosed body of water on the island Lacromo in the Adriatic, having 

underground connection with the sea. Salinity, 3.1744 per cent'.' Analysisby W. Loebischand L. Sipocz, 

Min. Mitt., 1876, p. 171.
THE OCEAN.

Analyses of oceanic falls Continued.

123

Cl..................

Br.. .................

S04 .. ...............

CO,.. ................

Na..................

K.. ..................

Rb.... ..............

Ca.. ....... ..........

Mg.. ........... ......

Fe, Si02l P04 .. .......

Fe, NH4 , NOV .......

(Fe,Al)203 , Si02 .....

X

Cl. .................

Br.... ...............

S04 ....... ...........

C03 .. ...... ..........

Na........... .......

K.. ..................

Rb. .................

Ca... ................

Mg.. .................

Fe, SiO,, P04 ........

Cl..................

Br......... ..........

S04 .................

C03 . .................

Na..................

K............ ........

Rb.. ................

Ca.. .................

Mg............. ......

Fe, SiOo, P04 ........

A

55. 292 

.188 

7.692 

.207 

30. 593 

1. 106

1. 197 

3.725

100. 000

[

1 55. 46

7.59 

.30 

30.53 

1.12

1. 21 

3.79

100. 00

Q

55. 12

.18

7.47 

.46 

30.46 

1.16

1. 41

3.74

100. 00

B

55. 185 

.179 

7.914 

.213 

30. 260 

1. 109

1.244 

3.896

100. 000

J

55.22 

.14 

7.88 

.10 

30.65 

.93 

.04 

1. 21 

3.75 

.08

100. 00

R

55. 59 

.14

7.67 

.01 

31.21 

.64 

.03 

1.05 

3.64 

.02

100. 00

c

55.04 

.19 

7.86 

.18 

30.71 

1.06

1.27 

3.69

100. 00

K

55. 30 

.14 

7.78 

.07 

30.85 

.89 

.04 

1. 16 

3.69 

.08

100. 00

s

55.60 

.13 

7.65 

.02 

30.81 

.97 

.04 

.89 

3.87 

.02

.00. 00

»

55. 21 

.19 

7.69 

.09 

30.82 

1.16

1.21 

3.61

.02

100. 00

I155. 45 

7.79

30.41 

1. 17

1. 18 

3.82

100. 00

T

55. 96 

.18 

7.49 

.13 

30.31 

1.06

1.22 

3.65

100. 00

E

55.01 

.13 

8.00 

.14 

3. 047 

.96 

.04

1.67 

3.53 

.05

100. 00

.M

55. 53 

.18 

7.74 

.19 

30.37 

1.09

1.26 

3.64

100. 00

u

55.46 

.13 

7.91 

.04 

30.23 

.94 

.03 

1. 19 

4.03 

.04

100. 00

V

54. 62

8.01 

.27 

30.20 

2.10

1.36 

3.36

.08

100. 00

N '

55. 11 

. 19 

7.89 

.20 

30.64 

1.09

1.23 

v 3. 65

100. 00

V

55.43 

. 13 

7.76 

.03 

30. 67 

.97 

.04 

1.19 

3.75 

.03

100. 00

G

55. 24

.17

7.54 

.34 

30.80 

1.10

1.22 

3.59

100. 00

o

55. 30 

.16 

7.72 

.19 

30. 51 

1.12

1. 19 

3.81

II

55.25

7.56 

.37 

30.76 

1.14

1.22 

3.70

100. 00

P

55.45 

.17 

7.67 

.28

.......

1. 22

100. 00

w

55. 4'1 

.13 

7.79 

.05 

30.89 

.85 

.03 

1.1.6 

3.67 

.02

LOO. 00

.......

X

54. 78 

.26 

7.60 

.72 

30.57 

1.11

1.25 

3.71

100. 00

Some of the differences between the foregoing figures are no larger 

than can be ascribed to differences in analytical methods or in the 

atomic-weight factors used for calculation. The waters of the Baltic 

and Black seas, with their very low salinity, show the effect of dilution by fresh water, which appears in the slightly higher percentage 

of calcium. Still, allowing for all possible sources of divergence, 

the essential uniformity in composition of ocean salts is perfectly 

clear. The mass of the ocean is so great, and the commingling of its
124 DATA OF GEOCHEM1STKY-.

waters by winds and currents is so thorough, that the local changes 

produced by the influx of rivers are exceedingly small. The salinity 

may range from less than 1 to over 4 per cent, but the saline composition remains practically the same.

For the composition of ocean salts in general, Dittmar's average 

should be taken as the standard of comparison. It represents the 

largest number of complete analyses and the greatest refinement of 

methods; the samples examined covered the widest geographic range 

and were drawn from various depths of water. Some were surface 

specimens, others from the bottom of the sea, and still others from 

points between, and all the results lead to the same general conclusion 

of nearly uniform composition, in spite of variable salinity. The 

individual analyses vary but little from the mean. The salinity is 

shown to be a function of temperature, pressure, and density; and the 

last factor is represented by J. Y. Buchanan's elaborate determinations, which appear in the same volume with Dittmar's analyses.1 

In general, according to the summary given in the "Narrative" of 

the Challenger expedition,2 the density and therefore the salinity of 

ocean water diminishes from the surface to a depth of 800 to 1,000 

fathoms, and then increases to the bottom. Toward both poles there 

are areas of concentration due to the formation of ice, a process which 

removes water from liquid circulation, leaving a large part of its salts 

behind. Freezing, as 0. Pettersson 3 has shown, modifies the composition of salt water, so that the brine formed from melting ice differs 

notably from the parent solution. Two analyses by Forsberg 4 serve 

to illustrate this point. Both are here reduced to standard form in 

order to facilitate comparison with those of normal sea water.

Analyses of brine from melting ice.

B. Liquid intermingled with snow, collected on Arctic ice at 32°. 

A. Another sample free from snow, also collected at 32°.

Cl+Br... ......................................................

S04 ...........................................................

Na. ...........................................................

K. ...........................................................

Ca. ............................................................

Mg.......... .................................................

A

62.47

1.26

25.88

.97

2.00

7..42

100. 00

B

63.52

.82

27.85

1.06

1.51

5.24

100.00

1 Natterer also, in the memoirs already cited, discusses the relations between density and salinity. So, 

too, docs H. Tornoe in Den Norske Nordhavs-Expedition, 1880. See also memoirs by A. Bouquet de la 

Grye, Annales chim. phys., 5th ser., vol. 25,1882, p. 433; and A. Chevallier, Compt. Rend., vol. 140,1905. 

p. 902. On this theme there is an extensive literature, but physical problems can be only incidentally considered in. the present memoir.

s Vol. 2,1882, pp. 948-1003.

a Vega Exped. Rept., vol. 2,1883, pp. 349-380.

< See 0. Pettersson, op. cit., 1883, p. 376.
THE OCEAN. 125

The elimination of sulphates and the increase of chlorides is here 

clearly indicated, and if we refer back to the tables previously given 

we shall see that the Arctic waters are all slightly higher in sulphates 

than Dittmar's average for the great oceans.

.In one sense the salinity of sea water is a function of climate, at 

least so far as surface waters are concerned. Where the rainfall is 

slight and the evaporation rapid, concentration occurs; where the 

atmosphere is saturated with moisture, the reverse is true. The Red 

Sea shows the maximum effect of evaporation and the highest salinity; 

the Mediterranean is next in order. West of the Nile no large 

rivers enter the Mediterranean; the evaporation along the African 

shore is very great, and the salinity is therefore excessive. Furthermore, rainfall serves to dilute the superficial layers of the ocean, 

and the same effect is produced by the influx of streams. The 

Black Sea, for instance, is diluted by the Danube, and its average 

salinity barely exceeds 2 per cent. When a river enters the ocean, its 

waters tend to flow upon the surface, and its influence may be detected 

at great distances, sometimes hundreds of miles from land. Salinity, 

in short, is the product of many agencies, and the commingling of 

waters is never quite complete. In view of conditions like these 

the nearly uniform composition of sea salts is all the more striking.

It is commonly assumed that the salts of the ocean are derived 

from the decomposition of rocks by flowing and percolating waters, 

which finally deposit their burden in the great general reservoir. 

That this opinion is in a very large measure correct is unquestionable; whether it is wholly true, without qualification, is another 

matter. We have already seen, in the preceding chapter, that an 

enormous mass of soluble salts is annually discharged by rivers into 

the sea, but its composition is very different from that of the saline 

substances which we 'are now considering. In the one class of waters 

carbonates and calcium prevail; in the other we find mainly chlorides and sodium. If, then, ocean water is continually receiving 

water unlike itself, its composition must be slowly changing, but the 

gains, although large in themselves, are relatively small in comparison with the vast accumulations of saline matter into which they 

diffuse. Whatever changes may take place must proceed very 

slowly, and no known methods of analysis are delicate enough to 

detect them, even were the observations to be continued through 

many centuries. For instance, calcium is one of the minor constituents of sea water, and yet J. Murray and R. Irvine 1 estimate 

that the discharge of rivers would require 680,000 years to make up 

the total oceanic amount.2

 ' Proc.-Roy. Soc. Edinburgh, voh 17,1889, pp. 100-101.

* For a statistical paper-on the mineral matter in the sea, see R. D. Salisbury, Jour. Geology, vol. 13, 

1905, p. 469. See also A. C. Lane, Jour. Geology, vol. 14,1906, p. 221, and A. B. Macallum, Trans. Canadian 

Inst., vol. 7,1903, p. 535.
126 DATA OF GEOCHEMISTRY.

Practically, then, the composition of the ocean is very nearly constant and has been so for long periods of time. We can not, by 

means of analysis, measure the changes in it, but we can observe 

some of them in operation, and see whither they tend. They are due 

either to gains or losses of material, and both conditions have been 

noted in the preceding pages. The gains from rivers and from rainfall are obvious; the losses by precipitation we shall examine presently. 

Some salts, as we observed in studying the atmosphere, are lifted 

from the ocean to fall again, partly upon the land, in rain. Much of 

this material returns into the sea, but we can not assume that all of it 

is regained. This loss, however, is trifling, and needs no further 

consideration here. Streams bring more chlorine and more sodium 

into the ocean than it loses through the mechanical action of the air. 

For these constituents a small net gain may safely be taken for granted. 

As for the changes in composition produced in sea water by freezing, 

they are local and transitory in character. When the ice melts, its 

saline contents are restored to oceanic circulation, although not always 

at the point from which they were withdrawn. To the slight change 

thus produced in Arctic waters reference has already been made.

CARBONATES IN SEA WATER.

Although calcium and carbonic acid are subordinate constituents 

of sea water, their importance can hardly be overestimated. They 

are the chief additions made by rivers to the ocean, and they are 

the substances most largely withdrawn from it by living organisms. 

Removed from solution, they form calcium carbonate, and that is the 

principal material of corals and shells.

Normal calcium carbonate is nearly but not. quite insoluble in 

water. Upon this point many observations have been made. According to T. Schloesing,1 whose data appear to be trustworthy, a 

liter of water at 16° can dissolve 0.0131 gram of CaC03 . With respect 

to sea water, however, the different varieties of the carbonate behave 

differently. This has been shown by R. Irvine and G. Young,2 who 

found that amorphous calcium carbonate is more soluble than the 

crystalline forms. To dissolve 1 part of the former 1,600 parts of 

sea water are required, as compared with 8,000 parts for the crystalline carbonate. This difference bears directly upon the theory of 

coral reefs. The living animal secretes amorphous carbonate, but 

after decomposition a partial change to crystalline carbonate occurs. 

Without this molecular rearrangement the coral would much more 

largely dissolve and its stability would be greatly diminished. Some

' Compt. Rend., vol. 74, 1872, p. 1552.

2 Proc. Roy. Soc. Edinburgh, vol. 15,188S, p. 310. For other data on the solubility of calcium carbonate 

in sea water, sec W. S. Anderson, Proc. Roy. Soc. Edinburgh, vol. 16,1889, p. 318; and J. Thoulct, Compt. 

Rend., vol. 110, 1890, p. 652.
THE 'OCEAN. 127

re-solution, however, occurs, especially where the waves have beaten 

the coral into sandj and this subject has been well studied by 

J. Murray and R. Irvine.1 They find that the porous corals dissolve 

more readily than the compact varieties.

In presence of free carbonic acid, the solubility of calcium carbonate 

is increased many fold. If we disregard ionization we may say that 

calcium bicarbonate, CaK^O,,, is then formed, a compound which is 

chiefly known in solution. Of this salt, as shown by F. P. Treadwell 

and M. Reuter,2 a liter of pure water at 15° can dissolve 0.3850 gram, 

a quantity which may be considerably increased by -an excess of 

carbon dioxide in the water. In sea water this solubility is modified 

by the presence of other compounds. E. Cohen and M. Raken,3 

experimenting with an artificial sea water, found that at 15° it was 

saturated by 55.6 milligrams of fixed C02 per liter, equivalent to 0.1264 

gram of CaC03 . According to G. Linck,4 the maximum solubility 

of calcium carbonate in sea water at 17°-18° is 0.191 gram per liter. 

The total quantity of calcium carbonate in average sea water, as 

shown by Dittmar's analyses, and upon the assumption that all of the 

C03 radicle is thus combined, is not far from 0.121 gram per liter. 

This, which is a maximum, is even below the saturation figure given 

by Cohen and Raken, and much lower than that of Linck. It would 

be diminished by the formation of other carbonates, and it must vary 

with fluctuations in the free or half-combined carbonic acid of the 

water. The latter constituent of sea water does not appear in the 

analyses of dried oceanic salts.

Calcium bicarbonate is very unstable and can be broken down to 

normal carbonate and free carbon dioxide by evaporation, by rise of 

temperature, or by mechanical agitation.5 The warm surface layers 

of the ocean, according to J. Johnston and E. D. Williamson,0 are 

practically saturated with carbonates, which are subject to precipitation not only by changes of temperature but also by fluctuations in 

the amount of carbon dioxide in the adjacent air. A change of 2° 

C. on the one hand, or from 3.2 to 3.0 parts per 10,000 of C02 will 

cause the precipitation of 2 grams of calcium carbonate in 1 cubic 

meter of a saturated solution. Under certain conditions the carbonate thus produced may assume the solid form and be precipitated as. a sort of calcareous ooze. This, however, can take place

' Proc. Roy. Soc. Edinburgh, vol. 17, 1889, p. 79.

" Zeitschr. anorg. Chcmic, vol. 17, 1898, p. 170.

3 Proc. Sec. Sci., Amsterdam Acad., vol. 3, 1901, p. 63.

* Ncues Jahrb., Boil. Band 16,1903, p. 505. A recent paper on the solubility of calcium carbonate, by 

J. Kendall, is in Philos. Mag., ser. 6, vol. 23, 1912, p. 958. On the solubility of calcite in natural waters 

sec J. Johnston and E. D. Williamson, Jour. Am. Chem. Soc., vol. 38,1916, p. 975, and It. C. Wells, Jour. 

Washington Acad., vol. 5, 1915, p. 617. Wells (Jour. Am. Chcm. Soc., vol. 37, 1915, p. 1704) has also 

s.tudicd the solubility of magnesium carbonate.

} W. Dittmar, Challenger Kept., Physics and chemistry, vol. 1, p. 211,18S4.

" Jour. Geology, vol. 24, 1916, p. 729. See also J. F. McClcndon (Proc. Nat. Acad. Sci., vol. 3, 1917, p, 

612) on tho equilibrium of sea water with respect to calcite and aragonite.
128 DATA OF GEOCHEMISTRY.

only in very shallow waters, and especially near the mouths of streams 

which carry carbonates in maximum amount. Such a deposition of 

calcium carbonate, forming a crystalline limestone, was long ago 

observed in the delta of the Rhone; and a similar reaction is taking 

place among the Florida Keys. Sea water, however, is not entirely 

saturated with carbonates, and a precipitate forming on the surface of 

the open ocean would be redissolved before it could settle to the bottom. Even shells undergo solution, and in sufficiently deep water they 

may entirely disappear. In the reports of the GhaXlenger expedition 

there is much valuable information on this point.1 Pteropod remains 

were never found on the ocean floor at depths below 1,500 fathoms, but 

the more resistant globigerina was collected at 2,500 fathoms. These 

animals live at or near the surface; after death the shells slowly sink, 

and, while sinking, partially or wholly dissolve. The decay of their 

organic matter generates abundant carbonic acid, and this aids in 

effecting solution. Be this as it may, the Challenger investigations 

show that the quantity of calcium carbonate on the bottom of the 

ocean depends in great measure upon the depth of water. Beyond 

the limits radicated little calcium carbonate is found, a fact which 

will be considered more in detail presently.

Calcium carbonate, then, takes part in a great system of changes 

whose magnitude and direction can hardly be estimated. It enters 

the sea in fresh waters; part of it is withdrawn by living animals to 

form coral or shell; some of the material thus used is redissolved, 

but much of it is permanently deposited in limestones or calcareous 

shales. Limestone formations of marine origin in all quarters of the 

globe testify to the importance of these processes. Living animals 

secrete more calcium carbonate than is redissolved, 2 but the inflow 

of fresh waters tends to supply the loss. Whether a balance is preserved it is impossible to say. The problem is complicated by the 

fact that the erosion of limestones laid down in former geologic 

periods now supplies material to streams, thus returning to the ocean 

carbonates which were once withdrawn from it.3

In this system of gains and losses some otherwise unimportant 

constituents of sea water play an interesting part. Kadiolarians, 

diatoms, and siliceous sponges extract silica from the ocean; this 

material is finally deposited upon the sea floor and does not redissolve, or at least not readily.4 " The silica brought in by rivers is partly 

disposed of in this way. Phosphates are also withdrawn, but the bony 

parts of marine creatures, after the death of the latter, go to a great

1 See summary in vol. 2 of the Narrative, 1882, pp. 943 et seq.

2 See J. Murray and R. Irvine, Proc. Boy. Soc. Edinburgh, vol. 17, 1889, p. 79.

' On the circulation of calcium carbonate, and its relation to the age of the earth, see E. Dubois, Proc. Sec. 

Sci., Amsterdam Acad., vol. 3, 1901, pp. 43, 116.

4 The insolubility of silica in sea water is great but not absolute. J. Murray and A. F. Renard ( Challenger Rept., Deep-sea deposits, 1891, p. 288) find that some silica can be dissolved out from diatomaceous 

ooze.
THE OCEAN. 129

extent into solution again. Iron, silica, and some potassium are laid 

down in the form of glauconite; and the substances dredged up from 

the bottom of the ocean tell us of still other reactions which are not 

easy to explain.

OCEANIC SEDIMENTS. 1

On the subject of oceanic sediments there is a voluminous literature. 

A great part of it relates to what may be called mechanical deposits, 

like gravel, sand, river silt, and so on a class of substance that does 

not concern us now. Their chemical character will be discussed elsewhere, with reference to their origin. Near land, and especially at the 

mouths of rivers, the sea bottom is covered mainly by mechanical 

sediments or by the remains of marine animals; in mid-ocean the 

deposits are of a very different type.

An entire volume of the Challenger reports, by J. Murray and 

A. F. Renard, is devoted to the subject of "Deep-sea deposits," and 

special attention is paid to substances formed by chemical action on 

the ocean floor.2 The larger deposits may be classified as follows:

Deposits on the ocean floor.

Name.

Globigerina ooze .......................................

Pteropod ooze. .........................................

Average depth 

in fathoms.

2,730

2,894

1, 477

2,049

1,044

Percentage of 

CaCOs6.70

4.01

22.96

64.47

79.25

The oozes derive their names from the characteristic organic 

remains which they contain, and they merge by slight gradations 

one into another. The classification is obviously approximate, not 

absolute. If we consider them together, and include the coral muds, 

the average percentage of calcium carbonate upon the sea bottom at 

various depths is as follows:

Variation of calcium carbonate with depth.

Per cent. 

Under 500 fathoms............... 86.04

500 to 1,000 fathoms.............. 66. 86

1,000 to 1,500 fathoms. .......... 70. 87

1,500 to 2,000 fathoms. .......... 69. 55

Per cent. 

2,000 to 2,500 fathoms. .......... 46. 73

2,500 to 3,000 fathoms. .......... 17. 36

3,000 to 3,500 fathoms. .......... .88

3,500 to 4,000 fathoms. .......... None.

The disappearance of carbonates with increasing depth is thus 

clearly shown.

Of all these deposits, the red clay, which covers about 51,500,000 

square miles, is the most extensive, and from a chemical point of view

1 A treatise by L. W. Collet (Les d<Sp6ts marins, Paris, 1908) deals with this subject quite fully.

a See also J. Murray, Geog. Jour., vol. 19,1902, p. 691, on material collected in 1901 by S. S. Britannia.

113750° 19 Bull. 695 9
130 . DATA OF GEOCHEMISTRY.

the most interesting. It is universally distributed in the oceanic 

basins, but is typical only at depths ranging from 2,200 to 4,000 

fathoms and far from land. Various theories have been proposed to 

account for its formation; but Murray and Renard look on it as essentially a chemical deposit, produced by the decomposition of silicates 

of volcanic origin. Remnants of volcanic rocks are found on nearly 

all parts of the ocean floor, and fragments of pumice are particularly 

common. Some of these doubtless came from ordinary sub aerial volcanoes, either as direct flows into the ocean, or as volcanic dust borne 

long distances by currents of air. Other fragments represent submarine volcanoes. Some of the specimens studied by Murray and 

Renard were quite fresh, others were largely decomposed; and in a 

number of them zeolites had been formed by subaqueous alteration. 

Crystals of phillipsite were repeatedly identified. The color of the 

clay is due to ferric oxide or hydroxide, which is easily removable by 

means of strong acids. In all essential respects the clay resembles the 

residues formed by the decay of igneous rocks. Its composition, 

as shown by many analyses, is extremely variable.

That sea water will attack and dissolve silicates is well known, 

although its efficiency is less than that of fresh water. On this 

subject the experiments of J. Thoulet 1 have been often quoted, and 

A. Johnstone 2 has shown that even so refractory a mineral as talc is 

slowly but perceptibly soluble. The process of change is of course 

almost inconceivably slow; but in the quiet depths of the ocean it has 

doubtless been going on throughout all geological time. It began 

when the first volcanic ejeatanienta entered the sea, if such a moment 

can be imagined, and has been operative continuously to the present 

day. Cosmic and other dusts have contributed something to the 

formation of the clay, and so, too, have animal remains; but volcanic 

matter seems to have been the chief starting point. This is the view 

of Murray and Renard, and it is the opinion best sustained by chemical 

evidence. Possibly, however, submarine volcanoes must also be 

taken into account.

In addition to the widespread formations mentioned in the foregoing paragraphs, the sea bottom yields many interesting products 

of a sporadic or local character. Among them are the well-known 

manganese and phosphatic nodules and glauconite; and these we 

may briefly consider in regular order.

Manganese, as oxide or hydroxide, exists in all deep-sea deposits, 

sometimes as grains in the clay or ooze, sometimes as a coating upon 

pumice, coral, shells, or fragments of bone, and often in the form of 

nodular concretions made up of concentric layers about some other

1 Compt. Rend., vol. 108,1889, p. 753. See also recent work by J. Joly, in Compt. rend. VIII Cong. ge"ol. 

internal;., 1900, p. 774.

2 Froc. Roy. Soc. Edinburgh, vol. 16,1889, p. 172.
THE OCEAN. 131

substance as a nucleus. 1 Even in shallow waters, as in Loch Fyne in 

Scotland, these nodules have been found,2 but they seem to be more 

characteristic of the deeper ocean abysses, whence the dredge often 

brings them up in great numbers.

The origin or mode of formation of the manganese nodules is still 

in doubt. Murray 3 regards tiie manganese as derived, like the red 

clay, from the subaqueous decomposition of volcanic debris. C. W. 

Giimbel 4 attributes the nodules to submarine springs holding manganese in solution, which is precipitated on contact with sea water, 

Buchanan 5 invokes the reducing agency of organic matter, which 

transforms the sulphates of sea water to sulphides, precipitating iron 

and manganese in the latter form to be subsequently oxidiz.ed. This 

view was contested by R. Irvino and J. Gibson c who showed that 

manganese sulphide was decomposed by sea water, the manganese 

redissolving as bicarbonate. J. B. Boussingault 7 holds that the manganese was derived from carbonates carried in solution by oceanic 

waters and a similar explanation has been offered by L. Dieulafait.8 

The oxidation of the carbonates is supposed to take place at the surface, through atmospheric contact, after which the precipitated oxide 

fails to the bottom of the sea.

Of all these theories, that of Murray seems to be the best substantiated. The manganese can easily be derived from the alteration of 

rock fragments, as it is by weathering on land; it goes into solution 

as carbonate, is oxidized by the dissolved oxygen of the sea water, 

and is precipitated near its point of derivation around any nuclei 

which happen to be at hand. The nodules occur in close association 

with altered volcanic materials, and most abundantly in connection 

with the red clay of similar origin; furthermore, their impurities are 

of the kind which the suggested mode of formation would lead us to 

expect. In composition the nodules vary widely, ranging from 4.16 

 to 63.23 per cent of manganese oxide: The analysis by J. Gibson ° 

is the most complete one among the man}r which were made, and is 

therefore selected as representative. The entire sample contaiiied 

Water....................................................... 29. G5

Aqueous extract 10 ........................................... 2. 44

Insoluble residue.............................................. 17.93

Portion soluble in HC1.. I...................................... 49. 97

99.99

1 For full description see Challenger Rept., Deep-sea deposits, 1891, pp. 341-378.' Sec also J. Murray and 

R. Irvine, Trans. Roy. Soc- Edinburgh, vol. 37,1895, p. 721. 

8 J. Y. Buchanan, Proc. Roy. Soc. Edinburgh, vol. 18,1890, p. 19.

3 Proc. Roy. Soc. Edinburgh, vol. 9,1876, p. 255.

4 See abstract in Neues Jahrb., 1878, p. 809.

6 Proc. Roy. Soc. Edinburgh, vol. 18,1890, p. 17,

3 Proc. Roy. Soc. Edinburgh, vol 18,1890, p. 54..

7 Annaleschim. phys.,5thser., vol. 27,1882, p. 289. '

8 Compt. Rend., vol. 96,1883, p. 718.

 Challenger Rcpt., Dcop-sca deposits, 1891, pp. 417-423.

"> Saline matter unavoidably inclosed in the nodules. Gibson gives its composition in detail.
132 DATA OP GEOCHEMISTRY.

The insoluble and soluble portions, recalculated separately, are 

represented in the subjoined statement:

Analysis of manganese nodule.

SiOa .. .................................................

Ti02 ... ................................................

.A1303 ..................................................

Fe203 . .................................................

MgO. ...:... .............................................

CaO. ............................:.....................

SrO. ...................................................

BaO. . .................................................

MnO..... ..............................................

MO. ..................................................

CoO. .............:....................................

ZnO. ..................................................

CuO.. .................................................

PbO..................................................

T120...................................................

Na.20. ..................................................

KaO. ................................................. PA- .................................................

vo

MoO3 . ................................................

S03 - ..................................................

C02 .. ...................................................

Peroxide oxygen. ......................................

Portion soluble 

in HC1.

6.34

26.97

4.60

4.02

49 Q4

1.96

.56

.20

.74

.10

.06

.22

.14

.20

' .94

.58

9.42

99.99

 Insoluble 

portion.

74. 58

. 72

12. 93

4.79

1.45

.11

.67

3.62

05

.11

99.93

If we include in this analysis the water of the original material we 

see that it represents a mixture of manganese, iron, and aluminum 

hydroxides, soluble in hydrochloric acid, with an insoluble residue of 

silicates. The specimen came from a depth of 2,375 fathoms.

The phosphatic.concretions found on the ocean floor offer a simpler problem for solution. As Murray and Renard* show, they are 

directly derived from the "decaying bones of dead animals, upon 

which carbonic acid exerts a powerful solvent action." They form, 

like the manganese nodules, around various nuclei, but preferably 

upon organic centers, such as shells. In many cases the phosphatic 

matter was first deposited in cavities of shells, around which the 

nodules -continued to grow, inclosing various muddy impurities. 

Probably the ammoniacal salts which are generated by the decomposition of organic -matter in the bone play some part in the precipitation of the calcium phosphate. The following analyses, by Element, 

show the composition of these bodies. A was from a depth of 150 

and B from 1,900 fathoms.

i Challenger Kept., Deep-sea deposits, 1891, pp. 397-400. On the phosphatic nodulus of the Agulhas 

Bank, seo L. W. Collet, Proc. Roy. Soc. Edinburgh, vol. 25,1905, p. 862; and L. Cayeux, Bull. Soc. g&>]. 

France, 4th ser., vol. 5,1906, p. 750.
THE OCEAN.

Analyses of phosphatic concretions from sea bottom.

p f\ £gs:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::

err

SiO, ...........................................................

CaC). ..........................................................

MgO...... .....................................................

Fe203 - .........................................................

Al O

Insoluble residue. ..............................................

A

1C) Oft

12.05

1.37

1.36

39.41

.67

2.54

1.19

TJndet.

17.34

95.89

B

23.54

10 fi4

1.39

2.56

40.95

.83

2.79

1.43

3.65

11.93

99.71

Analyses of the insoluble residue gave the following results:

Analyses of insoluble residue from phosphatic concretions.

Si02 .. .........................................................

AI n

FeA-- ........................................................

GaO- ..........................................................

MgO............................................................

A

77.43

12.40

7.91

1.07

1.02

' 99. 83

B

76.58

13. 85

7.93

1.27

1..18

100. 81

The concretions, then, consist mainly of calcium phosphate and 

carbonate, mixed with sand and clay.

The last of the oceanic deposits which we need to consider in this 

connection is glauconite, a hydrated silicate of potassium and ferric 

iron. It is widely disseminated upon the sea bottom, but most abundantly in comparatively shallow waters and near the mud line surrounding continental shores that is, it is formed "just beyond the 

limits of wave and current action, or in other words, where the fine 

muddy particles commence to make up a considerable portion of the 

deposits." 1 It is developed principally in the interior of shells, but 

its mode of formation is obscure. Murray and Renard argue that 

after the death of the organism the shell first becomes filled with fine 

mud, upon which, in presence.of the sulphates of sea water, the 

organic matter of the animal may act. The iron of the mud is reduced to sulphide, which afterward oxidizes to ferric hydroxide, 

alumina being at the same time removed in solution and colloidal 

silica set free. The latter, reacting upon the hydroxide, in presence 

of potassium salts derived from adjacent minerals, finally generates 

glauconite. This theory is supported by the observation that the

i Murray and Renard, Challenger Kept., Deep-sea deposits, 1891, p. 383.
134 DATA OF GEOCHEMISTRY.

glauconitic shells are always associated with the detritus of terrigenous 

rocks, containing orthoclase, muscovite, and other minerals from 

which the necessary potassium could be obtained. In a later portion 

of this work we shall have to examine the subject of glauconite more 

fully. An elaborate discussion of it would be out of place now.

Oceanic deposits, then, whether of shell, coral, red clay, manganese 

nodules, or glauconite, are in a sense the fossil records of chemical 

reactions which have taken place in the depths of the sea. They 

represent both additions to and withdrawals of matter from the 

waters of the ocean, with the formation of new substances by chemical 

change.1

The relative quantities of the chemical sediments thus annually 

formed can be approximately estimated. For this purpose we may 

first compare in detail the actual amount of each radicle poured 

into the ocean in one year with the total accumulation of saline 

matter in the ocean itself. The data are given in the following table:

Comparison of oceanic and fluviatile salts.

A. The annual addition of each radicle, by rivers, computed from the data already given in the preceding chapter.

B. The saline matter in the ocean, computed from Dittinar's analyses, with Karstcns's value for the 

volume of the ocean, 1,285,935,211 cubic kilometers, and a mean density of 1.026.

00........... .................................. sol............................................. 01.............. ................................

Br....... ......................................

N03 ... ........ ................................

Nn

K. ................... .........................

Ga.. ...........................................

Mg........... ...... ............................

^03 ... ........................................

SiOs .... ........................................

Sum............... .............................

A 

Annual from rivers 

(metric tons X103 ).

961, 350

332, 030

155, 350

24, (.14

258, 357

57, 982

557, 670

93, 264

75, 213

319, 170

2, 735,OOOX103

B

In ocean 

(metric tens X1012).

95.6

3, 553. 0

25, 538. 0

86.8

14, 130. 0

510. 8

552.8

1,721.0

46,188.0X1012

' If from each of the quantities in column A we subtract the amount 

annually retained in solution by the sea, the difference will represent 

the amount precipitated. To do this, an assumption must be made 

as to the age of the ocean; but whatever figure is assumed, the results 

will be of the same order of magnitude. For example, the ocean 

contains 552.8 X1012 metric tons of dissolved calcium; which quantity, divided by the assumed age, gives the annual increment. If 

the age of the ocean is 100,000,000 years, the annual addition of

' E. J. Jones (Jour. Asiatic Soc. Bengal, vol. 56, pt. 2,1887, p. 209) hasdescritedanother class of marine 

nodules. They were dredged up in 675 fathoms of water off Colombo, Ceylon, and contained about 75 per 

cent of barium sulphate.
THE OCEAN. 135 "\

f calcium has been 5,528,000 tons; if only 50,000,000 years it is 

11,056,000 tons. Subtracting these quantities from tjie total calcium of the river waters the remainders become 552,142,000 and 

546,614,000 tons, respectively; the difference being less than the 

actual uncertainties of the computation. Calculating upon both 

assumptions the annual precipitation of chemical sediments is as 

follows, in metric tons:

so

Ga.4 ............................................

Mg.. ...........................................

K. .............................................

Sib/.... .......................................

100,000,000

296, 500, 000

552, 142, 000

76, 054, 000

52, 874, 000

75, 213, 000

319, 170, 000

50,000,000

260, 970, 000

546, 614, 000

58, 844, 000

47, 766, 000

75, 213, 000

319, 170, 000

If we assume that all the calcium and magnesium are precipitated 

as carbonates and the sesquioxides as hydrates, the total amount 

of chemical sediments annually deposited, including coral reefs 

and calcareous oozes, is somewhere between 2,200,000,000 and 

2,400,000,000 metric tons. A little lime undoubtedly goes down as 

sulphate, although gypsum or anhydrite is found in oceanic sediments only in very small proportions. Probably much of the 

sulphuric radicle is reduced by organic matter, forming sulphides. 

The potassium is partly taken up by the clay substances of oceanic 

silt and partly goes to form glauconite, but there are no data from 

which to determine its actual distribution. Silica is assumed to be 

wholly thrown down, the trifling residue held in solution being 

negligible. Chlorine and sodium are held to remain dissolved.

The figures given above for the quantities of the chemical precipitates are, of course, by no means accurate. They are merely 

rough approximations. to the truth, but they tell something of the 

relative magnitudes. Even if we knew precisely the age of the ocean 

it would not be practicable to reckon backward and so to determine 

the total mass of deposits formed during geologic time. The 

figures tell us what is happening to-day, but are inapplicable to the 

past. The reason for this statement is, that apparently the different 

deposits have formed at different rates. In the beginning of chemical 

erosion fresh rocks were attacked, and relatively more silica and less 

lime passed into solution. At present, limestones laid down in previous geologic ages are being dissolved, and calcium is added to the 

ocoan more rapidly than in pre-Cambrian time. This is not mere 

speculation. A study of river waters with reference to their origin, 

whether from crystalline or sedimentary rocks, fully justifies my 

assertions.
136 DATA OF GEOCHEMISTRY.

So much for the annual precipitation. J. Joly, 1 by a different 

method, has calculated that the total mass of chemical sediments in 

the ocean is about 19.5X1018 metric tons. This estimate is not 

inconsistent with the foregoing computations. Purely mechanical 

sediments, such as river silt, volcanic ejectanienta, or dust brought 

by the atmosphere from the land, are obviously left out of consideration here. Their sum total could hardly be estimated, at least not 

with existing data. 2

POTASSIUM AND SULPHATES.

In seeking to balance the gains and losses of the ocean some account 

must be taken of potassium and of sulphates. The latter have 

already been mentioned as partly reduced by organic matter, a 

change which is counterbalanced to some extent by reoxidation 

under other circumstances. On the whole, sulphates seem to accumulate in the ocean, but the figures are not wholly concordant or 

satisfactory. The extent of their precipitation is by no means clear, 

although they are found in all the clays and oozes in trivial proportions.

With potassium other conditions hold, and river and ocean waters 

are not at all alike. In river waters, on an average, the proportion 

of potassium is about one-fourth that of the sodium; 3 but in sea 

water it is only one-thirtieth. In the igneous rocks sodium and 

potassium are nearly equal; they pass unequally into the streams, 

and in the ocean the difference is still further increased. What 

becomes of the potassium ?

The answer to this question is simple. Hydrous silicates of aluminum, the clays, are able to take up considerable proportions of 

potassium and to remove its salts from solutions. According to J. M. 

van Bemmelen, 4 ordinary soils will extract more potassium than 

sodium from solutions in which the salts of bo.th metals are present, 

even where the sodium is in excess. Potassium, then, is removed 

from natural waters as they percolate through the soil, or else by the 

suspended silt carried by streams. The sodium is not so largely withdrawn, and therefore its relative proportion tends steadily to increase. 

One metal.is deposited with the sediments, the other remains in 

solution.

) Radioactivity and geology, pp. 57, 58.

2 In an interesting but not altogether conclusive paper (Jour. Geology, vol. 2, 1894,'p. 318) J. A. Udden 

has endeavored to show that the dust carried by the atmosphere is of greater amount than the silt transported by rivers. See also E. E. Free, Science, vol. 29,1909, p. 423. In Bull. Bur. Soils No. 68, U. S. Dept. 

Agr., 1911, Free gives an elaborate discussion of the movement of the soil by wind, and a full bibliography 

of the subject.

3 Many of the analyses of river water, as published, show no potassium, but this only means that they 

arc incomplete. In such cases the alkalies were weighed together and in calculation the potassium was 

ignored. This is especially true of boiler-water analyses.

4 Landw. Vcrsuchs-Stationcn (Berlin), vol. 21, 1877, p. 135. The adsorption of potassium has been established by the work of .many investigators.
THE OCEAN. 137

These observations are confirmed in part by analyses of oceanic 

deposits, although the evidence is often incomplete. The larger 

number of analyses given for clay, mud, and ooze in the Cliallenger 

report contain no mention of alkalies, but when the latter are noted 

the potassium is commonly, not always, in excess. 1 In glauconite and 

phillipsite deposits potassium always predominates. L. Schmelck, 2 hi 

his analyses of clays from the northern Atlantic, records no alkalies, 

but K. Natterer,3 in sediments from the eastern Mediterranean and 

the Red Sea, found small quantities of potash and soda, and in nearly 

every instance potash was the more abundant of the two. In short, 

if the recorded analyses are correct, the clays and oozes of the deep 

sea have been partly leached of then' alkalies; but some of the potassium from the original volcanic material, with less sodium, has 

been retained in the production of zeolites. Nearer to land potassium 

has 1 been used in the formation of glauconite, and still nearer, where 

mechanical sediments appear, a similar discrimination is evident. 

Sodium dissolves, but potassium is held back. Potassium salts are 

also absorbed by some seaweeds in large quantities. This has been 

recently shown by D. M. Balch, 4 who finds that the giant algse of the 

California coast are remarkably rich in potassium chloride.

THE CHLORINE OF SEA WATER.

It is not possible at present to trace all of the changes which take 

place in ocean water, nor to account with certainty for the difference 

between sea salts and the material received from streams. In chemical character, fresh and salt water are opposites, as a brief inspection 

of the data will show. In ocean water, C1>S04 >C03 ; in average 

river water, C03 >S04 >C1. So also for the bases in the first case, 

Na >Mg >Ca; in the other, Ca >Mg >Na a complete reversal of the 

order. We can understand the accumulation of sodium in the ocean, 

and some of the losses are accounted for, but the great excess of 

chlorine in sea water is not easily explained. In average river water 

sodium is largely in excess of chlorine; in the ocean the opposite is 

true, and we can not well avoid asking whence the halogen element 

was derived. Here we enter the field of speculation, and the evidence upon which we can base an opinion is scanty indeed.5

To the advocates of the nebular hypothesis the problem is comparatively simple. If our globe was formed by cooling from an incan1 This conclusion is confirmed by a recent and very complete analysis of the "red clay," conducted in 

the laboratory of the United States Geological Survey. These sediments will be considered more fully in 

another chapter.

2 Den Norsko Nordhavs-Expedition, pt. 9,1882, p. 35.

8 Monatsh. Chcmie, vol. 14,1893, p. 624; vol. 15,1894, p. 530; vol. 20,1899, p. 1.

4 Jour. Indust. and Eng. Chem., vol. 1,1909, p. 777. These algse are now being commercially exploited 

as a source of potassium chloride.

, 6 On the ratio between sodium and chlorine in the salts carried by rivers to the sea, see E. Dubois, Proc. 

Sec. Sci., Amsterdam Acad., vol. 4, 1902, p. 388. On the ratio between Cl and SOt in sea water, see E. 

Ruppin, Zeitschr. anorg. Chcmie, vol. 09,1910, p. 232.
138 DATA OF GEOCHEMISTRY.

descent mass, its primitive atmosphere and ocean must have been 

quite unlike the present envelopes, and we may fairly suppose that 

they contained large quantities of acid substances. Hydrochloric 

acid in the atmosphere would imply a solution of hydrochloric acid 

in the sea, which might in time be neutralized by the bases dissolved 

from rocks and poured by rivers into the common reservoir. This 

argument has been especially developed by T. Sterry Hunt, 1 who 

shows that, if his premises are sound, the primeval ocean must have 

been much richer in calcium and magnesium than the sea is to-day. 

The richness of some artesian waters of Canada in lime salts, waters 

which Hunt regards as fossil remainders from the early sea, may be 

cited in support of his views.

On the other hand, R. A. Daly 2 has cited paleontological data in 

favor of the view that the pre-Cambrian ocean was nearly fre£ from 

lime. The absence of fossils from rocks of an age immediately preceding a period rich in highly developed calcareous forms is taken as 

evidence that the earliest life was essentially shell-less and softbodied, in consequence of a deficiency of lime salts in its environment. 

It is possible, however, that the pre-Cambrian animals were developed 

under conditions which favored the formation of aragonitic rather 

than calcitic exoskeletons. Aragonitic shells dissolve much more 

readily than those formed of calcite, and therefore rarely appear as 

fossils.

Another group of writers, seeking to avoid the nebular hypothesis, 

conceive the earth as having been built up by the slow aggregation 

of small, solid, and cold meteoric bodies. 3 Each of these, it is 

supposed, carried with it entangled or occluded atmospheric material. 

In course of time central heat was developed by pressure, and a 

partial expulsion of gas followed, thus forming an atmosphere 

derived from within. When the atmosphere became adequate to 

retain solar heat, and so to raise the surface temperature of the 

globe above the freezing point, the hydrosphere came into existence; 

but of its chemical nature at the beginning nothing, so far as I am 

aware, has been said by the advocates of this doctrine. There is, 

however, an analogy which may be utilized. Meteoric iron frequently incloses anhydrous ferrous chloride, or lawrenceite, a fact 

of which the curators of collections are painfully aware. The ferrous 

chloride deliquesces, the liquid formed then undergoes oxidation, 

ferric hydroxide is deposited, and acid solutions are developed which 

still further attack the iron. Through this process of corrosion

1 Am. Jour. Sci., 2d scr., vol. 39,1865, p. 176; and various papers in his Chemical and geological essays. 

See also J. Joly, on the geologic age of the earth, in Trans. Roy. Dublin Soc., 2d ser., vol. 7,1899, p. 23; and 

II. A. Taylor, Proc. Manchester Lit. Philos. Soc., vol. 50,1906, p. ix,

2 Am. Jour. Sci., 4th ser., vol. 23,1907, p. 93. Also a later paper in Bull. Geol. Soc. America, vol. 20,1909, 

p.153.

s See T. C. Chamberlin, Jour. Geology, vol. 5, 1897, pp. 653 et seq.; also H. L. Fairchild, Am. Geologist, 

vol. 23,1899, p. 94.
THE OCEAN. 139.

certain meteoric irons have crumbled into masses of rust and disappeared as museum specimens. If, now, the earth was formed 

from meteoric masses, some of them doubtless contained this annoying impurity, and chlorine from that source may have reached the 

primeval ocean. In fact, A. DaubreV found lawrenceite in the 

terrestrial native iron from Ovifak. The planetesimal hypothesis is 

evidently not inconsistent with the excess of oceanic chlorine. It is 

also in harmony with the idea advanced by E. Suess, 2 that the ocean 

has received large accessions from volcanic sources. Hydrochloric 

acid and'volatile chlorides exist in volcanic emanations and must, to 

some extent, reach the sea. G. F. Becker 3 has recently discussed 

this phase of the problem and has shown that a comparatively 

moderate emission of volcanic chlorine would fully account for the 

excess of that element in the ocean. But if, as* has often been 

suggested, the volcanic gases were first derived from oceanic infiltrations, they represent no gain to the ocean, and this question is 

still at issue.

THE DISSOLVED GASES.

Up to this point we have considered only the saline matter of the 

ocean; but the dissolved gases are almost equally important and have 

been'the subject of exhaustive investigations. The earlier researches 

were not altogether satisfactory, and we need therefore examine only 

the more recent data, first as to the air and then as to the carbonic 

acid of sea water.

The solubility of a gas in water varies with its nature and with the 

temperature, being greatest in the cold and diminishing as the solvent becomes warmer. The Arctic Ocean, therefore, dissolves more 

air than the waters of tropical regions, and it also seems to carry a 

greater proportion of oxygen. We have already seen, in studying 

the atmosphere, that water exercises a selective function in the solution of air, so that the dissolved gaseous mixture is enriched in oxygen. Ordinary air contains by volume only about one part in five of 

oxygen; dissolved air contains, roughly, one part in three; although, 

as we shall see> the proportion changes as conditions vary. Even the 

salinity of the ocean must probably be taken into account, for the 

reason that some if not all gases are less soluble in salt than in fresh 

water. According to the experiments by F. Clowes and J. W. H. 

Biggs,4 salt water dissolves only 82.9 per cent as much oxygen as is 

absorbed by fresh water. So large a difference can not well be 

ignored.

1 Etudes synthetiquas do geologic cxperunentalc, 1879, p. 557.

2 Geog. Jour., vol. 20,1902, p. 520. See also C. Doelter, Sitzungsb. Akad. Wicn, vol. 112,1903, p. "04. 

8 Smithsonian Misc. Coll., vol. 56, No. 6,1910. 

* Jour. Soc. Cuem. Ind., vol. 23,1904, p. 358.
140 DATA OF GEOCHEMISTRY.

To illustrate the difference in solubility between the two principal, 

atmospheric gases, we may use the data given by 0. Pettersson and, 

K. Sonden.1 In pure water the gases dissolve unequally, and the following table shows their solubility throughout a fair range of atmospheric temperatures. The figures represent the number of cubic centimeters of each gas, at 760 millimeters pressure, required to saturate 

1 liter of water; and the last column gives the percentage of oxygen 

in the dissolved mixture, when N + O = 100.

Solubility of nitrogen and oxygen in water at various temperatures.

Temperature.

 C.

0

6.00

6.32

9.18

13.70

14.10

Nitrogen

absorbed.

. cm?

19.53

16.34

16.60

15.58

14.16

14.16

Oxygen

absorbed.

cm?

10. 01

8.28

. 8.39

7.90

7.14

7.05

Percentage

of oxygen.

33.88

33.60

33.55

33.60

33.51

33.24

When we recall the fact that ordinary air contains only 21 per cent 

of oxygen, the magnitude of the change produced by solution becomes 

manifest.

In sea water the same relation holds approximately, but the enrichment is slightly greater. H. Toraoe,2 assisted by S. Svendsen, made 

94 analyses of air extracted from the water of the North Atlantic 

and found the oxygen in the mixture N + 0 to range from a minimum 

of 31 to a maximum of 36.7 per cent. Between 70° and 80° latitude the average was 35.64 per cent; below 70° it was 34.96. At the 

surface the mean percentage of oxygen was 35.3, and it diminished 

with the depth from which the samples were taken down to 300 

fathoms, when the proportion was reduced to 32.5. Below 300 

fathoms the percentage of oxygen was nearly constant. O. Jacobsen,3 

analyzing dissolved air from the water of the North Sea, obtained 

a range of 25.20 to 34.46 per cent, the surface average being 33.95.

Still more elaborate are the data published by W. Dittmar,4 whose 

samples of dissolved air came from .many points in the Atlantic, 

Pacific, Indian, and Antarctic oceans. The maximum amount was 

found in the Antarctic 28.58 cubic centimeters of air to the liter of 

water, containing 35.01 per cent of oxygen. The minimum, 13.73

> Ber. Deutsch. chem. Gesell., vol. 22,1SS9, p. 1439. Sse also R. W. Bunsen, Gasometrische Methoden; 

W. Dittmar, in his Challenger report; and A. Hamberg, Bihang K. Svensk. Vet.-Akad. Hand!., vol. 10, 

No. 13, 1884.

* Den Norske Nordhavs-Expedition, Chemistry, 1SSO, pp. 1-23. Tornoe in this memoir gives a good 

summary of the earlier investigations.

3 Die Ergebnisse der Untersuchungsfahrtcn S. M. Knbt. Drache, Berlin, 1886. An earlier memoir by 

Jacobsen is printed in Liebig's Annalen, vol. 167,1873, pp. 1 et seq.

* Challenger Kept., Physics and chemistry, vol. 1,1884. For the next table see p. 224. Also fora summary of the results obtained, see the "Narrative" of the expedition.
THE OCEAN. 141

cubic centimeters and 33.11 per cent, was obtained at a point southeast of the Philippine Islands. The general conclusions as to the 

solubility of nitrogen and oxygen in sea water at different temperatures appear in the following table:

Solubility of nitrogen and oxygen iv sea water at various temperatures.

Temperature.

°C.

0

5

30

15

20

25

30

35

Dissolved 

nitrogcn.a

cm. 3

15.60

13.86

12.47

11.34

10. 41

9.62

8.94

8.36

Dissolved 

oxygen .a

cm.3

8.18

7.22

6.4.5

5.83

5.31

4.87

4.50

4. 17

Percentage 

of oxygen.

34.40

34.24

34.09

33.93

33.78

33.62

33.47

33.31

o Supposed to be measured dry, at 0° C. and 700 millimeters pressure; in other words, the normal volumes 

in cubic centimeters in 1 liter of sea water at the given temperatures. The "nitrogen" of course includes 

argon.

No argument is needed to show the importance of the facts thus 

developed. The dissolved oxygen plays a double part in the activities 

of the ocean first in maintaining the life of marine organisms, and 

second in oxidizing 'dead matter of organic origin. By the latter 

process carbon dioxide is generated, and that compound, as we have 

already seen, helps to hold calcium carbonate in solution. Its other 

function as a possible regulator of climate will be considered presently.

Free or half-combined * carbonic acid is received by the ocean from 

various sources. It may be absorbed directly from the atmosphere or 

brought down in rain; it enters the sea dissolved in river water; it is 

derived from decaying organic matter, and submarine volcanic 

springs contribute a part of the supply. The free gas is also liberated 

from bicarbonates by the action of coral and shell building.animals, 

which assimilate the normal calcium salt. Carbonic acid is continually added to the ocean and continually lost, either to the atmosphere 

again or in the maintenance of marine plants, and we can not say how 

nearly the balance between accretions and losses may be preserved. 

The equilibrium is probably far from perfect; it may be disturbed by 

changes in temperature or by the agitation of waves, and every variation in it leads to important consequences. It is estimated that the 

ocean contains from eighteen to twenty-seven times as much carbon 

dioxide as the atmosphere, and that it is therefore, as T. Schloesing 2 

has pointed out, the great regulative reservoir of the gas.

' A much used but inexact expression. It describes the second molecule of carbonic acid which converts 

the normal salts into bicarbonates.

»Compt. Rend., vol. 90, 1880, p. 1410. See also A. Krogh, Meddelelser om Greenland, vol. 26, 1004, 

pp. 333, 409.
142 DATA OF GEOCHEMISTRY.

Nearly all of the authorities thus far quoted with reference to the 

dissolved air of sea water have also studied the omnipresent carbonic 

acid. Jacobsen, Hamberg, Tornoe, Buchanan, Dittmar, Natterer, 

and others have made numerous determinations of its amount, and as 

a general rule the quantities found were insufficient to transform all of 

the normal calcium carbonate into the acid salt. Tornoe, as the average of 78 sea-water analyses, found 52.78 milligrams to the liter of 

fully combined carbon dioxide, and in addition 43.64 milligrams available for the formation of bicarbonates. Results of the same order 

were obtained by Natterer in his examination of waters from the 

Mediterranean. Normal carbonate and bicarbonate are both present 

in sea water, although in a few exceptional determinations during the 

CffiaUenger expedition the carbonic acid was clearly in excess. Such 

instances, however, are rare, and are ascribable to purely local and 

unusual conditions.

The carbonic-acid determinations of the Challenger voyage were 

conducted partly by J. Y. Buchanan on. shipboard, and partly by 

W. Dittmar on land. 1 The combined acid has already been accounted 

for in the analyses given for sea salts; the "loose," free, or half-combined acid, is more variable. Its average amount, in milligrams to 

the liter, at different temperatures appears in the following table:

Averaye amount of free carbonic add in sea water at various temperatures. 

[Milligrams per liter.]

25° to 28.7°0..................... 35. 88

20° to 25°G.....:................ 37.18

15° to 23°C...................... 42.68

10°tol5°G...................... 43.50

5°tolO°C....................... 47.21

 1.4° to +3.2°C.................. 53.31

That is, the ocean contains less free carbonic acid in warm than in 

cold latitudes. Its average quantity is estimated by Murray at 45 

milligrams per liter, which is equivalent to a layer of carbon 3.45 

centimeters thick over the entire oceanic area. For different depths 

of water the variations in carbonic acid are less pronounced, as may 

be seen from the subjoined averages:

Average amount of free carbonic acid in sea water at various deptlis. 

 [Milligrams per liter.]

Surface........................... 42. G

25 fathoms..............:......... 33. 7

50 fathoms........................ 48. 8

100 fathoms....................... 43. G

200 fathoms....................... 44. G

300 fathoms....................... 44.0

400 fathoms....................... 41.1

800 fathoms....................... 42.2

More than 800 fathoms.............. 44. 6

Bottom............................ 47.4

The figures are derived from 195 determinations by Buchanan, and 

the individual numbers range from 19.3 to 96 milligrams to the liter. 

In 15 determinations the carbonic acid was in excess of the amount

1 See vol.1 of the report on physicsand chemistry and part 2 of the " Narrative,"p. 979; also J. Y. Buchanan 

in Proc. Roy. Soc., vol. 22,1S74, pp. 192, 4S3. The tables cited arc from the "Narrative."
THE OCEAN. 143

necessary to form bicarbonates; in only 22 was it sumcient to fully 

convert the normal into the acid salt.

In the light of the evidence just presented, and speaking from the 

point of view of the modern theory of solutions, we-may say that'the 

water of the ocean contains not only the normal carbonic ions, C03 , 

but also a considerable proportion of the bicarbonic ions HC03 . 

The latter ions arc unstable, and their existence is conditional on 

temperature, so that although they are continually forming they are 

as continually being decomposed. That is, between the ocean and 

the atmosphere there is an interchange of carbonic acid, which is 

released from the water in warm climates and absorbed again in the 

cold. The atmospheric supply of carbon dioxide is thus alternately 

enriched and impoverished, and the conditions affecting equilibrium 

are of several kinds. This problem has been elaborately discussed 

by C. F. Tolman, jr., 1 from the standpoint of the physical chemist, 

and his memoir should be consulted for the detailed argument. The 

essential features of the evidence upon which a theoretical discussion 

can be based are already before us. We have considered the oceanic 

losses and gains of carbon dioxide, and it remains to correlate them 

with the corresponding changes in the atmosphere. This can not be 

done quantitatively, for the rates of consumption and supply are not 

measurable. In particular, the carbon dioxide from volcanoes and 

volcanic springs is not a determinable quantity.

That the surface of the earth has been subjected to climatic alternations, to glacial periods and epochs of greater warmth, is a commonplace of geology. To account for such changes, various astronomical 

and physical theories have been proposed, and with these, of course, 

chemistry has nothing to do. Whether, for example, the solar constant of radiation is really a constant or not is a question which the 

chemist can not attempt to answer. The chemical portion of the 

problem is all that concerns us now; and that relates to the variable 

carbonation of the atmosphere.

The researches of Arrhenius on the possible climatic significance of 

carbon dioxide were cited and criticized in a previous chapter, and we 

then saw that its variation in the atmosphere might be attributed to 

fluctuating volcanic activity. A varying supply of the gas was 

postulated, and its influence on atmospheric temperatures was shown 

to offer a plausible, but not well-sustained, explanation of alternating 

climates. A variable consumption of carbon dioxide would obviously 

produce much the same effect, and it is therefore evident that supply 

and loss must be considered together. Disregarding for the moment 

the doubtful validity of Arrhenius's hypothesis, we may consider the

i Jour. Geology, vol. 7,1899, p. 585. See also memoirs by C. J. J. Pox, Trans. Faraday Soc., vol. 5,1909i 

p. 68; J. Sticglitz, Pub. 107, Carnegie Inst. of Washington, 1909, p. 235; E. lluppin, Zeitschr. anorg. Chemic, 

vol. 66,1910, p. 122. Ruppin discusses especially the alkalinity of sea water. On carbon dioxide in water of 

tho Gulf of Mexico, see R. C. Wells, Prof. Paper U. S. Geol. Survey No. 120-A, 191S.
144 DATA OF GEOCHEMISTRY.

 interesting work of T. C. Chamberlin,1 who has sought to show that 

the ocean is the prime agent in producing the observed changes. 

The supplies of carbon dioxide are drawn from the storehouse of the 

ocean, they are consumed in the decomposition of silicates on land, 

and they are regenerated by the action of lime-secreting animals, 

which set carbonic acid free, as well as by changes in temperature.

According to Chamberlin, an important factor in climatic variation is the fluctuating elevation of the land. During periods of 

maximum elevation, when the largest land surfaces are exposed to 

atmospheric action, the consumption of carbon dioxide in rock 

weathering is great and the air becomes impoverished. When depression occurs and the oceanic area enlarges, a smaller quantity of silicates is decomposed and less carbonic acid disappears. The first 

change is thought to produce a lowering of temperature, which is 

increased by the consequent greater absorbability of carbon dioxide in 

sea water; the second causes a relative rise, intensified by a release of 

the gas from solution. Enlargement of land area implies a low temperature, whereas a decrease is conducive to warmth,.both conditions 

hinging on the variability produced in the atmospheric supply of carbonic acid and its effectiveness as a retainer of solar radiations.

But this is not all of the story. A depression of the land is accompanied by an increased area of shoal water in which lime-secreting 

organisms can flourish, and they liberate carbon dioxide from bicarbonates. A period of limestone formation is therefore correlated 

with an enrichment of the atmosphere, and consequently with the 

maintenance of a mild climate. The ocean is the great reservoir of 

carbonic acid, and upon its exchanges with the atmosphere the 

variations of climate are supposed partly to depend. This argument 

does not exclude consideration of the volcanic side of the problem, 

but the oceanic factor seems to be the larger of the two.

CJiamberlin's theory is ingenious, but may perhaps carry more 

weight if stated in somewhat different form. C. G. Abbot and F. E. 

Fowle,2 who have studied the influence of the atmosphere upon solar 

radiations with great care, show that in the lower regions of the atmosphere water vapor is present in such quantities as almost completely to 

extinguish the radiation from the earth irrespective of the presence 

of carbon dioxide. They therefore say that "it does not appear 

possible that the presence or absence or increase or decrease of the 

carbonic acid contents of the air are likely to appreciably influence 

the temperature of the earth's surface.

Water vapor, then, is the chief agent in the atmospheric regulation 

of climate, and to this conclusion Chamberlin's theory may be

1 Jour. Geology, vol. 5,1897, p. 653; vol. 6,1398, pp. 459, 609; vol. 7,1899, pp. 545, 667, 7J1. Chamberlin'S 

views are criticized by A. Kro^h in Meddelelser om Greenland, vol. 26,1904, pp. 333, 409.

2 Annals Astrophys. Observ., vol. 2, 190S, pp. 172,175.
THE OCEAN. 145

adjusted. When the area of land surface increases, evaporation 

from the ocean diminishes, and vice versa. The climatic conditions 

may vary as Chamberlin claims, but the relative dryness or wetness 

of the atmosphere may be the true cause of fluctuating temperatures 

rather than the carbon dioxide.

INFLUENCE OF LIVING ORGANISMS ON THE OCEAN.

One other important factor in marine chemistry remains to be 

considered namely, the influence of living organisms. These, both 

plants and animals, are almost incredibly abundant in the ocean,1 

and then* vital processes play a great part in its chemical activities. 

This fact has already been noted on what might be called its inorganic side that is, with reference to the function of marine organisms in secreting phosphate and carbonate of lime. Coral reefs and 

the submarine oozes are made up of animal or plant remains, calcareous or siliceous, and their aggregate amount is something enormous.

The living animals, however, do much more than to secrete inorganic material. In developing they absorb large quantities of carbon, hydrogen, nitrogen, and oxygen', the principal constituents of 

their soft tissues. These elements, in one form of combination or 

another, are released again by decomposition after the organism 

dies, and they are also eliminated to a certain extent by the vital 

processes of the living creatures. Where life is abundant there carbon dioxide is abundant also, and its activity as a solvent of calcium 

carbonate is greatest.2 The relations of the ocean to carbon dioxide 

can not be completely studied without taking into account both 

plant and animal life.

When marine animals die they may become food for others, the 

scavengers of the sea, or they may simply decompose. The latter 

fate, obviously, most often befalls creatures whose soft parts are 

protected by hard shells. Water, carbon dioxide, and ammoniacal 

salts are the chief products of decomposition, and ammonium carbonate, thus formed, acts as a precipitant of calcium compounds.3 

The calcium carbonate thus thrown down is in a finely divided condition, and therefore peculiarly available for absorption by coral 

and shell builders. The ammonium salts also, as shown by Murray 

and Irvine, are food for the marine flora, and on that some portions 

of the fauna subsist.

i The abundance of life in the ocean is admirably stated by W. K. Brooks, in Jour. Geology, vol. 2,1894, 

p. 455. Its chemical significance can hardly be exaggerated.

" See W. L. Carpenter in C. Wyvillo Thomson's Depths of the sea, 1874, pp. 502-511. Where C02 was 

abundant in bottom waters, the dredge brought up a good haul of living forms. Where it was deficient, 

the hauls were poor.

a See J. Murray and R. Irvine, Proc. Roy. Soc. Edinburgh, vol. 17,1889, p. 89.

113750° 19 Bill 1. 695 10
146 DATA OF GEOCHEMISTRY.

But this is not all. , Decomposing ...organic, matter reduces..the 

sulphates of-sea water to sulphides,- which by-reaction with carbonic, 

acid yield sulphureted hydrogen.- This process, as shown by Murray 

and Irvine,1 is particularly effective in bottom waters in ^contact 

with "blue mud," and by it local changes are produced in the 

composition of the waters themselves. Bacteria also assist in the 

process, and according to N. Androussof,2 this H2S fermentation is 

especially conspicuous in the Black Sea. Some of the hydrogen 

sulphide passes into the atmosphere and is lost to the ocean; some 

of it reacts upon the iron silicates of the sea floor, to form pyrite or 

marcasite; and some is reoxidized to produce sulphates again 

From all of these considerations we see that the biochemistry of the 

ocean is curiously complex, and that its processes are conducted 

upon an enormous scale. The magnitude of tbeir influence can not 

be expressed in any quantitative terms, and must long remain an 

unmeasured factor in marine statistics. In all probability the circulation and distribution of carbon in the ocean is as much influenced by living beings as by exchanges between the sea and the 

atmosphere.

AGE OF THE OCEAN.

The facts that we can estimate, with some approach to exactness, 

the absolute amount of sodium in the sea, and that it is added in a 

presumably constant manner without serious losses, have led to various attempts toward using its quantity in geological statistics.3 

The sodium of the ocean seems to furnish a quantitative datum from 

which we can reason, whereas calcium, magnesium, silica, potassium, 

etc., are more or less deposited from solution, and so become unavailable for the discussion of such problems as that of geologic time.

Nearly 200 years ago Edmund Halley 4 suggested that the age of 

the earth might be ascertained by measuring the rate at which rivers 

delivered salt to the sea. The suggestion was of course fruitless for 

the time being, because the data needed for such a computation were 

undetermined, but it was nevertheless pertinent, and it now seems 

to be approaching realization. For reasons already given, the method 

proposed for estimating geologic time can as yet be only applied 

provisionally, the data still being imperfect, although rapidly accumulating. The present state of the problem is worth considering now.

The first really serious attempt to measure geologic time by the 

annual additions of sodium to the ocean seems to have been made by

i Trans. Roy. Soc. Edinburgh, vol. 37,1895, p. 481. See also Challenger Kept.. Deep-sea deposits, 189J.. 

p. 254; W. N. Hartley, Proc. Roy. Soc. Edinburgh, vol. 21,1897, p, 25; and Murray and Irvine, idem, p. 35. 

3 Guide dcs excursions du VU Cong. ge"ol. internat., No. 29.

3 See, for example, Chapter I of the present volume, where the relative volumes of the sedimentary rocks 

are estimated.

4 Philos. Trans., vol. 29,1715, p. 296. See an abstract in G. F. Becker's Age of the earth: Smithsonian 

Misc. Coll., vol. 56, No. 6,1910; also in Science, vol. 31,1910, p. 459.
THE OCEAIST. 147

J. Joly l in 1899. Joly, with Murray's figures for rainfall, run-off, and 

the average composition of river water, combined with Dittmar's 

analyses of oceanic salts and an estimate of the mass of the ocean, 

deduced an unconnected value for the age of the ocean of 97,600,000 

years. The calculation is very simple, and by the following equation :

Na in ocean , , _____ =-=-= : : =Age of ocean. 

.Annual Na in rivers fo

Joly's data, however, were much less satisfactory than the data 

now at hand, as given in this and the preceding chapter. With them 

the equation now becomes

14,130 X 10"

158,357 X103-

the crude age of the ocean to which certain corrections are yet to be 

applied.2 The first of these to be studied tends to increase the quotient, others to diminish it.

A part of the sodium found in the discharge of rivers is the socalled ''cyclic sodium"; that is, sodium in the form of salt lifted 

from the sea as spray and blown inland to return again to its source 

in the drainage from the land.3 Near the seacoast this cyclic salt is 

abundant; inland its quantity is small. The table given in Chapter 

II illustrates the way in which the amount falls off as we recede from 

the shore, and the isochlors of the New England "chlorine maps" 

show the same thing jnost conclusively. Joly estimates that the correction for cyclic salt may be 10 per cent; but Becker in his paper 

on the age of the earth has discussed the isochlor evidence mathematically, and found that 6 per cent is a more trustworthy value. 

By Ackroyd the significance of the correction is enormously overestimated. Adopting Becker 's figure, and deducting 6 per cent from the 

total river load of sodium, the remainder becomes 148,846,000 metric 

tons, which, divided into the sodium of the ocean, gives a quotient of 

94,712,000 years. Joly's correction of 10 per cent is very nearly

1 Trans. Roy. Dublin Soc., 2dser., vol. 7, 1899, p. 23,.and with later corrections, Rept. British Assoc. Adv. 

Sci., 1900, p. 369. Criticized by W. Mackio, Trans. Edinburgh Geol. Soc., vol. 8, 1902, p. 240; and O. Fisher, ' 

Geol. Mag., 1900, p. 124. See also V. von Lozinski, Mitt. K.-k. geog. Gesell. Wien, vol. 44, 1901, p. 74. Ho 

cites a paper by E. von Romer, Kosmos, vol. 25, 1900, p. 1, which I have not seen. Related memoirs are 

by E. Dubois, Proc. .Sec. Sci., Amsterdam Acad., vol. 3, 1901, pp. 43, 116; vol. 4, 1902, p. 388. The presidential address of W. J. Sollas (Quart. Jour. Cool. Soc., vol. 65, 1909, p. xli) is mainly devoted to this theme. 

For more details see F. W. Clarke, Smithsonian Misc. Coll., vol. 56, No. 5, 1910, and G. F. Becker, idem, 

No. 6.

8 These figures differ from those given in my Preliminary study of chemical denudation. In that I used 

Dole's data for American rivers, in which all the alkalies were reckoned as sodium alone. The new computation js based on Palmer's determinations of potassium, which must be subtracted from the former sum. 

The latter gave 175,040,000 metric tons Na (+ K), as against the 158,357,000 Na now employed.

8 For the quantities of salt thus transported see the table given in Chapter II. For a discussion of the 

significance of the correction for cyclic sodium, see J. Joly, Geol. Mag., 1901, pp. 344, 504; Chem. News, vol. 

83, p. 301; and British Assoc. Report, 1900, p. 369. Also W. Ackroyd, GeoL Mag., 1901, pp. 445, 558; Chem. 

News, vol. 83, 1901, p. 265; vol. 84, 1901, p. 56.
148 -DATA OF GEOCHEMISTRY.

equivalent to the assumption that the entire run-off of the globe, 

6,524 cubic miles, according to Murray, carries on an average one part 

per million of chlorine. The chlorine maps, so far as they have been 

made, show this figure to be excessive.

The foregoing correction for " cyclic salt" is, however, not final. It 

has already been suggested that the wind-borne salt is only in part 

restored to the ocean, at least within reasonable time. Some of it is 

retained by the soil, if not permanently, at least rather tenaciously; 

and the portion which falls into depressions of the land may remain 

undisturbed almost indefinitely. In arid regions, like the coasts of 

Peru, Arabia, and parts of western Africa, a large quantity of cyclic 

salt must be so retained in hollows or valleys which do not drain into 

the sea. Torrential rains, which occur at rare intervals, may return 

a part of it to the ocean but not all. Some writers, Ackroyd,1 for 

example, have attributed the saline matter of the Dead Sea to an 

accumulation of wind-borne salt, an assumption which contains 

elements of truth but is probably extreme. A more definite instance 

of the sort is furnished by the Sambhar salt lake in northern India, 

as studied by T. H. Holland and W. A. K. Christie.2 This lake, 

situated hi an inclosed drainage basin of 2,200 square miles and over 

400 miles inland, appears to receive the greater part, if not all, of its 

salt from dust-laden winds which, during the four hot, dry months, 

sweep over the plains between it and the arm of the sea known as the 

Rann of ditch. Analyses of the air during the dry season showed 

a quantity of salt so carried which amounted to at least 3,000 metric 

tons over the Sambhar Lake annually, and 130,000 tons into Kajputana. These quantities are sufficient to account for the accumulated 

salt of the lake, which the authors were unable to explain in any 

other way.

Examples like this of the Sambhar Lake are of course exceptional. 

In a rainy region salt dust is quickly dissolved and carried away in 

the drainage. Only in a dry period can it be transported as dust 

from its original point of deposition to points much farther inland. 

It appears, however, that some salt is so withdrawn, at least for an 

indefinitely long time, from the normal circulation, and should, if it 

could be estimated, be added to the amount now in the ocean. Such 

a correction, however, would doubtless be quite trivial, and, therefore, negligible; and the same remark must apply to all the visible 

accumulations of rock salt, like those of the Stassfurt region, which 

were once laid down by the evaporation of sea* water. The saline 

matter of the ocean, if concentrated, would represent a volume of 

over 4,800,000 cubic miles; a quantity compared with which all beds 

of rock salt become insignificant.

i Chem. News, vol. 89,1904, p. 13. * Records Geol. Survey India, vol. 38,1909, p. 154.
THE OCEAN. 149

But although the visible accumulations of salt are relatively insignificant, it is possible that there may be quantities of disseminated 

salt which are not so. The sedimentary rocks of marine origin must 

contain, in the aggregate, vast amounts of saline matter, widely distributed, but rarely determined by analysis. These sediments, laid 

down from the sea, can not have been completely freed from adherent 

salts, which, insignificant in a single ton of rock, must be quite appreciable when cubic miles are considered. The fact that their presence 

is not shown in ordinary analyses merely means that they were not 

sought for. Published analyses, whether of rocks or of waters, are 

rarely complete, especially with regard to those substances which 

may be said to occur in " traces."

It is perhaps not possible to evaluate the quantity of this disseminated salt, and yet a maximum limit may be assigned to it. In 

Chapter I it was shown that 84,300,000 cubic miles 1 of the average 

igneous rock would yield, upon decomposition, all the sodium of the 

ocean and the sedimentaries. The volume of the sandstones would 

be approximately 15 per cent of this quantity, or 12,645,000 cubic 

miles. Assume now that the sandstones, the most porous of rocks, 

contain an average pore space of 20 per cent, or 2,529,000 cubic 

miles, and that all of it was once filled with sea water, representing 

118,730,000,000,000 metric tons of sodium. If all of that sodium 

were now present in the sandstones, and chemical erosion began at 

the rate assigned to the rivers, namely, 158,357,000 tons of sodium 

annually, the entire accumulation would be removed in about 750,000 

years. This, compared with the crude estimate already reached for 

geologic time is almost a negligible quantity. The correction for 

disseminated salt is therefore small, and not likely to exceed 1 per 

cent.

The foregoing calculations, so far as they relate to the age of the 

ocean, imply the assumption that the rivers have added sodium to 

the sea at an average uniform rate, slight accelerations being offset 

by small temporary retardations. For the moment let us consider 

one phase of this suggested variability. The present rate of discharge 

has been hastened during modern times by human agency, and that 

acceleration may be important to take into account. The sewage 

of cities, the refuse of chemical manufactures, etc., are poured into 

the ocean, and so disturb the rate of accumulation of sodium quite 

perceptibly. The change due to chemical industries, so far as it is 

measurable, is wholly modern, and that due to human excretions is 

limited to the tune since man first appeared upon the earth. Its 

exact magnitude, of course, can not be determined, but its order 

seems to be measurable, as follows:

1 This quantity, it must be remembered, is a maximum. The true value is probably very much less, 

by 10 per cent or even more.
150 DATA OF GEOCHEMISTRY.

According to the best estimates, about 14,500,000 metric tons of 

common salt are annually produced, equivalent to 5,700,000 tons of 

sodium. If all of that was annually returned to the ocean, it would 

amount to a correction of about 3.25 per cent on the total addition of 

sodium to the sea. The fact that much of it came directly or indirectly from the ocean in the first place is immaterial to the present 

discussion; the rate of discharge is affected. All of this sodium, 

however, is not returned; much of it is permanently fixed in manufactured articles. The total may be larger, because of other additions, 

excretory in great part, which can not be estimated, but we may 

assume, nevertheless, a maximum of 3 per cent as the correction to 

be applied. Allowing 6 per cent, a's already determined, to cyclic or 

wind-borne sodium, and 1 per cent to disseminated salt of marine 

origin, the total correction is 10 per cent. This reduces the 

158,357,000 tons of river sodium to 142,521,000 tons, and the quotient representing crude geologic time becomes 99,143,000 years.

The corrections so far considered are all in one direction, and 

increase, by a roughly evaluated amount, the apparent age of the 

ocean. Other corrections, whose magnitudes are more uncertain, 

tend to compensate the former group. The ocean may have contained primitive sodium, over and above that since contributed by 

rivers It receives some sodium from the decomposition of rocks by 

marine erosion, which is estimated by Joly as a correction of less than 

6 per cent and more than 3 per cent on the value assigned to geologic 

time. Sodium is also derived from volcanic ejectamenta, from 

"juvenile" waters, and possibly from submarine rivers and springs. 

The last possibility has been considered by Sollas, 1 but no numerical 

correction can be devised for it. These four sources of sodium in the 

sea may be grouped together as nonfluviatile, and reduce the numerator of the fraction which gives the age of the ocean. Whether they 

exceed, balance, or only in part compensate the other corrections it 

is impossible to say.

From the foregoing computations it is to be inferred that the age of 

the ocean, since the earth assumed its present form, is somewhat less 

than 100,000,000 years. If, however, any serious change of rate in 

the supply of sodium to the sea has taken place during geologic 

time, the estimate must be correspondingly altered. This side of the 

question has been studied by G. F. Becker in the memoir already 

cited, who has shown that the rate was probably greater in early 

times than now, and has steadily tended to diminish. When erosion 

began, the waters had fresh rocks to work upon. Now, three-fourths 

of the land area of the globe are covered by sedimentary rocks or by 

detrital and alluvial material, from which a large part of the sodium 

has been leached. The accessible supply of sodium has decreased,

1 Presidential address, Quart. Jour. Gcol. Soc., May, 190&.
' THE OCEAN. ' 151

and it may be supposed that at some remote time in the future it will 

be altogether exhausted. From considerations of this order Becker 

has developed an equation representing the supply of sodium to the 

ocean during past time by-a descending exponential, and has shown 

that the age of the ocean, as deduced from the data already given, 

must lie somewhere between 50 and 70 millions of years. The higher 

figure, he thinks, is closer to the truth than the lower one. If the 

ocean was initially saline the estimate of its age would be still further 

reduced. Becker's conclusions are fairly accordant with the results 

derived from physical, astronomical, and paleontological evidence, 

although the study of radioactivity among minerals has led to 

much higher figures for the age of the earth. The latter line of 

evidence will be considered in another chapter, but it seems that the 

rate of chemical erosion offers a more tangible and definite mode of 

attack upon the problem of geologic time. The problem can not be 

regarded as definitely solved, however, until all available methods of 

estimation shall have converged to one common conclusion. 1

 * For persistent criticisms of the chemical method ot computing geological time, see H. S. Shelton, Chem. 

News, vol. 99,1909, p. 25], vol. 102,1910, p. 75; vol. 112,1915, p. 85; Jour. Geology, vol. 18,1910, p. 190; Sci. 

Progress, vol. 9,1914, p. 55. The criticisms are based upon a belief that the analyses of river waters are 

inaccurate, especially in tho determination of Na and SOi; that is, the skill and accuracy of many reputable 

chemists are questioned. On this subject, see the rejoinder by R. B. Dftlc, Chem. News, vol. 103, 1911, 

p. 289. Mr. Shelton also claims that he has found a discrepancy between the SOa determinations in waters 

and tho amounts found in igneous rocks. In making this claim ho has compared the moan percentago 

of S in tho great mass of ignooas rocks with that of the soluble matter leached from a thin film of surflcial 

deposits. The two quantities are not commensurable.
CHAPTER V.

THE WATERS OF CLOSED BASINS. 

PRELIMINARY STATEMENT.

In dealing with the ocean and its tributary rivers we have studied 

the hydrosphere in its larger sense, the waters all forming part of 

one great system of circulation which can be treated as a unit. 

But on all the continents there are isolated areas from which the 

drainage never reaches the sea. Streams originate in the higher 

portions of such areas, resembling in all respects those tributary to 

the ocean. Their waters gather in depressions and, ultimately, by 

the concentration of their saline constituents form salt or alkaline 

lakes or even dry beds of solid residues. The latter condition is 

developed in small areas of great aridity, where evaporation is so 

rapid that no large body of water can accumulate; but the more important closed basins are characterized by the formation of permanent 

reservoirs, such as the Caspian, the Great Salt Lake, and the Dead 

Sea. Each basin exhibits individual peculiarities of more or less 

local origin, and therefore each one must be studied separately. 

No such uniformity as that shown by the ocean is manifested here, 

although in some lakes we can recognize a curious approximation 

in chemical character to that of the open sea.

THE BONNEVILLE BASIN.

To American students the most accessible and therefore the most 

interesting of these isolated regions is that known as "the Great 

Basin" in the western part of the United States. This area is fully 

described in two monographs of the Geological Survey,1 in which it 

is represented as having been formerly the seat of two great lakes, 

Bonneville and Lahontan, of which only the remnants now exist. 

The Great Salt Lake of Utah is the chief remainder of Lake Bonneville 

and, with its accessory waters, may well occupy our attention first.

The water of Great Salt Lake has been repeatedly analyzed on 

the whole with fairly concordant results, except in regard to salinity. 

The latter varies with changes in the level of the lake, but is always 

several tunes greater than that of sea water. An early, incomplete 

analysis by L. D. Gale and a questionable one by H. Bassett are 

hardly worth reproducing. 2 . The other available data, expressed in 

percentages of total radicles, are as follows:

iG. K. Gilbert, Lake Bonneville: Mon. U. S. Geol. Survey, vol. 1, 1890 I. C. Russell, The geological 

history of Lake Lahontan: Mon. U. S. Geol. Survey, vol.' 11,1885. 

2 They are cited in Gilbert's monograph. Bassett's analysis is very high in potassium.

152
THE WATERS OF CLOSED BASINS. 153

Analyses of water from Great Salt Lake.

A. By 0. D. Alien, Kept. U. S. Geol. Expl. 40th Par., vol. 2,1877, p. 433. Water collected in 1869. A 

trace of boric acid is also reported, in addition to the substances named in the table. Alien also gives 

analyses of a saline soil ftom a mud flat near Great Salt Lake. It contained 16.40 per cent of soluble matter 

much like that of the lake water.

B. By Charles Smart. Cited in Resources and attractions of the Territory of Utah, Omaha, 1879. 

Analysis made in 1877.

C. By E. von Cochenhausen, for C. Ochsenius, Zeitschr. Deutsch. geol. 'Gesell., vol. 34, 1882, p. 359. 

Sample collected by Ochsenius April 16,1879. Ochseuius also gives an analysis of the salt rnarui facturcd 

from the water of Great Salt Lake.

D. By J. E. Talmage, Science, vol. 14, 1889, p. 445. Collected in 1889. Ananalys is of a sample taken 

in 1885 is also given.

E. By E. Waller, School of Mines Quart., vol. 14,1892, p. 57. A trace of boric acid is also reported.

P. By W. Blum. Collected in 1904. Recalculated to 100 per cent. Reported by Talmage in Scottish 

Geog. Mag., vol. 20,1904, p. 424. An earlier paper by Talmage on the lake is in the same journal, vol. 17, 

1901, p. 617.

G. By W. C. Ebaugh and K. Williams, Chem. Zcitung, vol. 32,1908, p. 409. Collected in October, 1907.

H. By R. K. Bailey, in the laboratory oJ the U. S. Geological Survey. Sample collected by H. S. Gale, 

October 24, 1913.

01..................

Br.. .................

S04 .................

oo,.. ..............

Li.................

Na. .................

K. .................

Ca.. ......... ........

Mg.. ...............

Fe203, A1203 , Si02 ...

Salinity, per cent. . . .

A

55.99

Trace.

6.57

Trace.

33.15

1.60

.17

2.52

100. 00 

14. 994

B

56.21

8.89

.07

33. 45

(?)

.20

3.18

100. 00 

13. 790

C

55.57

6.86

33.17

1.59

.21

2.60

100. 00 

15. 671

D

56.54

5.97

33.39

1.08

.42

2.60

100. 00 

19. 558

E

55.69

Trace.

6.52

.01

32.92

1.70

1.05

2.10

.01

100. CO 

a23.036

F

55.25

Trace.

6.73

Trace.

34.65

2.64

.16

.57

100. 00

27.72

G

55.11

6.66

32.97

3.13

.17

1.96

100.00 

22.99

H

55.48

6.68

.09

33.17

1.66

.16

2.76

100. 00 

20. 349

o More correctly, 230.355 grams per liter.

Although the salinity of the lake is very variable and from four to 

seven times as great as that of the ocean, its saline matter has nearly 

the same composition. The absence of carbonates, the higher sodium, 

and the lower magnesium are the most definite variations from the 

oceanic standard; but the general similarity, the identity of type, is 

unmistakable. Gilbert estimates the quantity of sodium chloride 

contained in the lake at about 400 millions and the sulphate at 30 

millions of tons.

For the waters tributary to Great Salt Lake many analyses are 

available.1 The following table relates to some of the streams, except 

that Sevier Lake, an outlying remnant of Lake Bonneville, is included 

as a matter of convenience. The analyses are all reduced to standard

i In addition to the data given here, see analyses by J. T. Kingsbury, of City, Red Butto, Farmington, 

Emigration, Parleys, Big Cottonwood, and Little Cottonwood creeks, cited by G. B. Richardson in WaterSupply Paper U. S. Geol. Survey No. 157,1906, p. 30; analyses made in 1882 and 1884. Field Operations 

Bur. Soils, U. S. Dept. Agr., 1903, p. 1138, contains analyses of Provo River, Spanish Fork, American Fork 

and Dry, Payson, Santaquin, Currant, and Warm creeks, but the analyst is not named. Other analyses 

of Great Salt Lake, complete and partial, are given by W. C. Ebaugh and W. Macfarlane in Science, vol. 

32,1910, p. 568. See also other analyses of Utah waters, by J. E. Greaves and C. T. Hirst, in Bull. 163, Utah 

Agr. Coll. Exp. Station, 1918.
154 DATA OF -GEOCHEMISTRY.

form, with bicarbonate radicles recalculated to normal G03 . Salinity 

is stated in parts per million.

Analyses of waters tributary to Great Salt Lake..

A. Bear River at Evanston, Wyoming. Analysis by F. W. Clarke, Bull. U. S. Geol. Survey No. 9, 

1884, p. 30.

B. Bear River at Corinne, Utah, near its mouth. Analysis received from the Southern Pacific Railroad,

C. Jordan -River at intake of Utah and Salt Lake canal. Analysis by F. K. Cameron, Kept. No. 04, 

Bur. Soils, U; S. Dept. Agr. 1900, p. 108.

D. Jordan River near Salt Lake City. Analysis by Cameron, loc. cit.

E. City Creek, Utah. Analysis by T. M. Chatard, Bull. U. S. Geol. Survey No. 9,18S4, p. 29.

F. Ogden River at Ogden, Utah.

G. Weber River at mouth of canyon. Analyses F and G made under the direction of F. K. Cameron, 

Field Operations Div. Soils, U. S. Dept. Agr., 1900, p. 226.

H. Sevier Lake. Analysis by Oscar Loew, Rept. U. S. Geog. Surveys W. 100th Mer., vol. 3,1S75, p. 114. 

Sample taken in 1872.

ci..... ...............

S04 .................

C03 .. ................

Na..................

K....................

Ca...................

Mg...................

fiiOj.. ................

(Al,Fe)B03 .. ..........

Salinity, parts per 

million............

A

2.68

5.76

52.68

1 4.49

23.69

6.86

3.84

100. 00

185

B

32. 36

8.16

21.53

120. 54

10.12

4.76

2.53.

100.00 

637

C

35.54

26. 54

2.67

V26.13 :

7.59

1.53

100. 00

892

D

34. 7G

30.68

Trace.

123.04

10.26

1.26

100. 00 

1,090

 E

5.38

2.87

52. 57

| 3.74

24.19

7.15

3.69

.41

100.00 

243

F

23.21

5.65

33.68

11.31

4.16

16. 05

5.94

100.00

444

G

13.73

9.25

40.00.

8.37

4.19

18.19

6.27

100. 00 

455

H

52.66

10.88

33.33

.12

3.01

100.00 

86, 400

Utah Lake, at the head of Jordan River, has furnished material for 

a most instructive series of analyses } as follows:

Analyses of water from Utah LaTcefl

A. By F. W. Clarke, Bull. U. S. Geol. Survey No. 9,1884, p. 20. 

B. By F. K. Cameron, 1899. 

C. By B. E. Brown, 1903.

D. Mean of three analyses by A. Seidell, 1904. Samples taken in May.

E. By B. E. Brown, 1904. CoUected August 31. For analyses B, C, D, and E, see F. K. Cameron, Jour. 

Am. Chem. Soc., vol. 27,1905, p. 113. All are here reduced to terms of normal carbonates.

ci.... ....... .........................

so4 ......... ..........................

nn

Li.....................................

Na.................... ................

K................... .................

Ca...... ...............................

Sr........................ ............

Mg..... ..............................

SiOa .. .................................

A

4.04

42.68

19.88

\ 5.81

18.24

6.08

3.27

100. 00 

306

B

35.48

26.53

2.66

1 26. 20

7.58

1.55

100. 00 

892

C

26. 23

28.49

10.23

19. 28

2.34

6.25

7.18

100. 00 

1,281

D

24. 75

28. 25

12.35

.06

18.19

2.17

5.90

.15

3.18

2.00

100. 00 

1, 165

E

26. 87

30. 14

8.48

18.34

1.75

5.34

6.85

2.23

100. 00 

1,254

a See also Greaves and Hirst, op. cit.
THE WATERS OF CLOSED BASINS. 155

Although the foregoing analyses are, in one respect or another, 

incomplete, they tell an intelligible story. Bear River at Evanston 

is a normal river water, which upon evaporation would yield mainly 

calcium carbonate, and so, too, is City Creek. Bear River, near its 

mouth, has changed its character almost completely and has evidently 

taken up large quantities of sodium chloride from the soil. Utah 

Lake, in the 20 years intervening between the earliest and latest 

analyses, has undergone a thorough transformation, and its salinity 

has more than quadrupled. From a fresh water of the sulphate type 

it has become distinctly saline, and this change is probably a result 

of irrigation. Its natural supplies of water have been diverted into 

irrigating ditches, and at the same time salts have been leached out 

from the soil and washed into the lake. To some extent these salts 

have been brought to the surface as a result of cultivation, so much 

so that considerable areas of land bordering upon the lake have 

ceased to be available for agriculture. Its outlet, Jordan River, 

exhibits the same peculiarities. As for Sevier Lake, which is now 

reduced to a mere pool in consequence of irrigation along its 

sources, its water resembles that of Great Salt Lake, except that at 

the time the analysis was made it was only about half as saline.

All the waters tributary to Great Salt Lake, so far as they have 

been examined, contain notable quantities of carbonates, which are 

absent from the lake itself. These salts have evidently been precipitated from solution, and evidence of this process is found in beds 

of oolitic sand, composed mainly of calcium carbonate, which exists 

at various points along the lake shore.1 The strong brine of the lake 

seems to be incapable of holding calcium carbonate in solution.

THE LAHONTAN BASIN.

The Quaternary Lake Lahontan, which once covered an area of 

8,400 square miles in northwestern Nevada, is now represented by a 

number of relatively small, scattered sheets of water and many 

alkaline or saline beds. Instead of one large basin there are now 

several basins, and each one is fed by independent sources of fresh 

water. Each lake, therefore, has its own individual peculiarities, as 

the various analyses show. Some of the lakes exist only during the 

humid season, when large areas are covered by a thin layer of water; 

others are permanent sheets of considerable depth. Our data relate 

only to the latter, with their sources of supply.

In the statement of some analyses precision, in a certain sense, has 

been sacrificed to uniformity. In strongly alkaline waters the radicle 

Si03 may possibly exist instead of the colloidal Si02 . In no case, 

however, is the silica high enough to cause a serious error in thia

i Seeanalyses by R. W. Woodward, cited in Rept. U. S. Geol. Expl. 40th Par., vol. 2,1877, p. 435. Also 

an. analysis by T. M. Cbatard, in Bull. U. S. Geol. Survey No. 228,1904, p. 331.
156 DATA OF GEOCHEMISTRY.

respect, and a fraction of 1 per cent will cover the uncertainty. A 

graver criticism might be based upon the representation of all the 

carbonates as normal, for bicarbonates are undoubtedly present in 

some of the waters, which on evaporation deposit trona in large 

quantities. If, however, we regard the analyses as representing the 

percentage composition of ignited residues, the suggested objection 

no longer holds. We can compare our data upon the uniform basis 

adopted hitherto and leave the question of bicarbonates for separate 

consideration later. The divergent character of the analyses seems 

to render some such procedure necessary. It is only by eliminating 

variables that we can obtain comparable results.

In the next table two groups of analyses appear. Lake Tahoe, a 

typical mountain lake of great purity, empties through Truckee 

River, which terminates in Winnemucca and Pyramid lakes. These 

waters are included in the first group. The second comprises 

Walker River and Walker Lake. The individual analyses, which, 

except when otherwise stated, are recalculated from the laboratory 

records of the Survey, are as follows:

Analyses of Lahontan waters I.

A. Lake Tahoe, California. Analysis by F. W. Clarke.

B. Truckee River, Nevada. Mean of two concordant "boiler-water analyses" received from the Southern Pacific Railroad.

C. Pyramid Lake, Nevada. Mean of four concordant analyses by Clarke.

D. Winnemucca Lake, Nevada. Analysis by Clarke.

E. Walker River, Nevada. Analyses by Clarke.

F. Walker Lake, Nevada. Mean of two analyses by Clarke. For analyses, A, C, D, E, and F, see Bull. 

U. S. Geol. Survey No. 9,1884.

01............................

S04 . ........................

oos... .......................

Na. ............. ............

K.. ..........................

Ca. ..........................

Mg......... ..................

Si02 .. .......................

(Al,Fe)203 .. ..................

Salinity, parts per million ....

A

3.18

7.47

38.73

10.10

4.56

12.86

4.15

18.95

100. 00 

73

B

7.59

12.87

33.30

1 17. 26

11.02

3.49

} 14. 47

100. 00 

153

e

41.04

5.25

14.28

33.84

2.11

.25

2.28

.95

100. 00 

3,486

D

47.88

3.76

7.93

36.68

1.94

.55

.49

.77

100. 00 

3,602

E

7.50

16.14

30.34

| 18. 07

12.96

2.21

12.78

100. 00 

180

F

oq 77

21.29

17.34

}

QA 00

.90

1.56

31

100.00 

2,500

The changes shown by these waters 1 are elaborately discussed by 

Russell in his work on Lake Lahontan. Ordinary fresh waters rich 

in carbonates and in calcium are concentrated, and the lime salts are 

finally thrown out in the form of tufa. The tufa, however, instead of 

being an oolitic or granular deposit, as in the Bonneville basin, is 

in the form of crystals, "thinolite," pseudomorphous after some 

unknown mineral, which may have been a calcium chlorocarbonate.

1 Except that of analysis B, which is more recent.
THE WATERS OF CLOSED BASINS. 157

This peculiar variety of tufa is characteristic of the Lahontan basin; 

but the mode of its formation is uncertain.. 1

Four more analyses of Lahontan waters remain to be considered,

as follows:

Analyses of Lahontan waters II.

G. Humboldt River, Nevada. Analysis by T. M. Chatard.

H. Humboldt Lake, Nevada. Analysis by O. D. Alien, Rept. TT. S. Geol. Expl. 40th Par., vol. 2, 

1877,p. 743.

I. The large Soda Lake, Ragtown, Nevada. Surface sample. Analysis by Chatard.

3. The large Soda Lake, sample from a depth of 30.5 meters. Analysis by Chatard. For these analyses 

of Chatard's see Bull. U. S. Geol. Survey No. 9, 1884. An earlier analysis of Soda Lake by 0. D. Alien 

is given in the Fortieth Parallel report, vol. 2,1877, p. 748. It is less complete than Chatard's, but otherwise not very different. This water contains bicarbonates. Specific gravity, 1.101.

ci............................................

804........................................... CO...........................................

POBA---. .................................

Na................... -.....-.-.-. ............ .

K. ...........................................

Da

Mg. ..........................................

Si02 . ........................................

AI n

G

2.19

13.92

39.55

13.63

2.92

14.28

3.62

9.51

.38

100. 00 

361

H

31.82

3.27

21.57

.07

29.97

6.54

1.35

1.88

3.53

100. 00 

929

I

36. 51

10.36

13.78

.25

36.63

2.01

.22

.24

100. 00 

113, 700

J

35.38

10.50

15.89

.26

35.38

2.13

.21

.25

100. 00 

113, 700

The first two of these analyses show the change from river to 

lake water very clearly. There is a concentration of chlorides and 

a relative loss in silica, magnesium, and calcium. The water of Soda 

Lake is more than three times as concentrated as sea water, and of 

an entirely different type. It has no visible supply of water except 

from springs near its margin, and at certain times it deposits trona 

and also gaylussite in notable quantities. Gaylussite is a carbonate 

of calcium and sodium, but no calcium is shown by Chatard's analyses. It must, therefore, be deposited by the lake about as rapidly 

as it is received. The tributary springs have not been investigated.

The Lahontan waters, then, are distinctly alkaline, whereas the 

lakes of the Bonneville basin are salt. The cause of the difference must 

be sought in the sources from which the waters are derived, and 

one distinction is clear. Great Salt Lake is fed by streams and 

springs which flow in great part through sedimentary formations. 

Its saline matter is a concentration of old salts which were laid down 

long ago. The Lahontan lakes, on the other hand, are supplied with 

water from areas of igneous rocks, in which rhyolites and andesites 

are especially abundant and from which the alkalies may be obtained. 

They represent, therefore, a primary concentration of leached matei See discussion by E. S. Dana, in Bull. U. S. Geol. Survey No. 12,1884. Calcite pseudomorphs, similar to thinolite and called pseudogaylussite, have been discussed by F. J. P. van Calkcr (Zoitschr. Kryst. 

Min., vol. 28,1897, p. 556) and C. O. Trechmann (idem, vol. 35,1902, p. 283). The Australian glcndonite 

isealcite pseudomorphous after glauberite and sometimes forms crystals 15 tc 2<? inches long. See T. W. E. 

David, Rec. Geol. Survey New South Wales, vol. 8,1905, p. 162.
158 DATA OF GEOCHEMISTRY.

rial, as contrasted with the secondary origin of the Bonneville brine. 

The difference is easily recognized, but it does not explain all of the 

phenomena. To account for the large amounts of chlorine in the 

waters, particularly in that of Great Salt Lake, is not so easy a 

matter. So far as I am aware, no plausible solution of the latter 

problem has yet been suggested. The cosmological speculations, 

which help us in the case of the ocean, hardly seem to be applicable

here.

LAKES OF CALIFORNIA.

Ill California there are a number of alkaline lakes having a general 

resemblance to those of the Lahontan basin. The following analyses 

are available, and in them, as usual, bicarbonates, if reported, have 

been reduced to normal form.

Analyses of water from alkaline lakes in California.

A. Mono Lake. Analysis by T. M. Chatard, Bull. U. S. Geol. Survey No. 60, 1890, p. 53. Sample 

taken in 1882. Specific gravity, 1.045. An improbable analysis of Mono Lake water, by Winslow Anderson, is given in his Mineral springs and health resorts of California, San Francisco, 1892, p. 198. In it the 

calcium salts predominate over all othe'rs.

B. Owens River at Charlies Butte. Mean of 36 ten-day composite samples, taken between December 

31,1907, and December 31,1908. Average analysis by W. Van Winkle and F. M. Eaton, Water-Supply 

Paper U. S. Geol. Survey No. 237, p. 121. A similar annual average is given for the water at Round Valley 

farther upstream.

C. Owens Lake. Analysis by Chatard, op. cit., p. 58. Specific gravity, 1.062. For an early analysis 

of Owens Lake see 0. Loew, Ann. Rept. Geog. Surveys W. 100th Mer., 1876, p. 190.

D. Owens Lake. Analysis by C. H. Stone, cited by W. T. Lee in Water-Supply Paper U. S. Geol. 

Survey No. 181,1908, p. 22. Sample taken in August, 1905.

E. Owens Lake. Analysis by W. B. Hicks in the laboratory of the U. S. Geological Survey. Specific 

gravity, 1.0977. An analysis by J. G. Smith is given in Bull. Dept. Agr. No. 61,1914, p. 80.

P. Black Lake, near Benton, Mono County. Analysis by Loew, op. cit., p. 191.

G. Tulare Lake in 1883. Analysis by E. W. Hilgard, Appendix to Rept. Univ. California Exper. Sta., 

1900. This lake has an outlet during floods, but not at other times. An analysis of water collected in 

1880 is also given.

H. Borax Lake. Analysis by W. H. Melville, published by G. F. Becker in Mon. U. S. Geol. Survey, 

vol. 13,1833, p. 235. In addition to the substances named in the table, the original residue contained 4 5 

per cent of organic matter.

01....................

Br... ................

I...................

S04 .................

rn

PO

B407 .--- ----.- - -.

NO...... ............

Li................. I.

Na. .................

K....................

Rb,Cs...............

Ca...................

Mg...................

Si02 ....... ..........

AlaOg....... .........

FeaOg. ........ .......

Mn203 ...............

Salinity, parts per 

million ............

A

23.34

12. 86 

23. 42

.32

37.93 

1.85

.04 

' .10 

.14 

Trace. 

Trace.

100. 00 

51. 170

B

9.49

15.53 

29.84

.48

119. 83

8.92 

3.45 

12.37

.09

100. 00 

339

C

25.67

9.95 

32.51

.48

37.83 

2.18

.02 

.01 

.29 

.04 

.02

100. 00

72, 700

D

24.82

9.93 

24.55 

.11

.14 

.45

.03

38.09 

1.62 

Trace. 

.02 

.01 

.14

} .04

.05

100. 00 

213.700

E

25.40

9.89 

.22.70

1.89

37.83 

2.09

.20

100. 00 

118. 830

F

7.68 

Trace. 

Trace. 

13.24 

37.73 

Trace. 

Trace.

Trace. 

39.05 

2.03

.27

100. 00 

18. 500

G

20.26

20.77 

19.55

35.79 

2.44

.28 

.26 

.65

100. 00 

4.910

H

32.27 

.04

.13

22.47 

.02 

5.05

38.10 

3,52

.03 

.35 

.01 )..

100. 00 

76, 560
'THE WATERS OF CLOSED 159

Like Soda Lake, Owens and Mono lakes both yield trona on evaporation, and at Owens Lake it has been prepared on a commercial scale. 1 

Soda Lake was also utilized at one time for the same purpose. Borax 

Lake, according to Becker, derives its boron from neighboring hot 

springs. It deposits some calcareous sinter.

NORTHERN LAKES.

The region of alkaline lakes continues northward from Nevada and 

California, and a number of the waters have been analyzed. The 

more important analyses are given in the following tables. Those 

made by W. Van Winkle are recalculated from the figures published 

in Water-Supply Paper No. 363, 1914, with bicarbonates reduced to 

normal salts.

Analyses of water from northern alkaline lakes.

A. Summer Lake, Oregon. Analysis by Van Winkle, who cites two other analyses. Specific gravity, 

1.0162 at 15°.

B. Ana River, a feeder of Summer Lake. Van Winkle, analyst. One other analysis is cited.

C. Abert Lake, Oregon. Analysis by T. M. Chatard, U. S. Geol. Survey Bull. No. 60,1890, p. 55. An 

earlier analysis by F. W. Taylor is not in accord with this. Specific gravity 1.03117, at 19.8°.

D. Abert Lake. Analysis by Van Winkle, who cites other analyses. Sample taken in February, 1912.

E. Chewaucau River, the chief feeder of Abert Lake. Van Winkle, analyst. Average of 37 analyses of 

composite samples of water, taken between August 11,1911, and August 14,1912.

F. Harney Lake, Oregon. Analysis by G. Steiger in the laboratory of the U. S. Geological Survey. 

Sample taken August 5,1902.

G. Harney Lake. Van Winkle, analyst. Collected March 10,1912. Specific gravity, 1.0209.

H. Malheur Lake, Oregon. Van Winkle, analyst. An analysis of Silver Lake, in the same general 

egion, is also given and one of Donner and Blitzen River, a feeder of Malheur Lake.

CL... ................

so4 .................

co3 ..................

PO

B

/-\ 4 o7 ................ "NO

Na..................

K.... ......... .......

Ca...................

Mtr

Si02 . ....... .........

A1203 ... .............

PeA.. ..............

Salinity, parts per

A

18.27 

4.18 

35.57

.02 

39.48 

1.59 

Trace. 

Trace. 

.62 

.27

Trace.

100. 00 

16, 633

B

7.07 

5.21 

3.73

.13 

1 25. 08

3.15 

2.83 

23.79

.01

100. 00 

156

C

36.04 

1.90 

20.67

39.33 

1.44

.62

100. 00 

39, 172

D

36.23 

1.91 

20.82

Trace. 

38.78 

1.69 

Trace. 

Trace. 

.36 

.21

Trace.

100. 00 

29, 564

E

0.66 

5.99 

28.79

.46 

9.06 

' 3.33 

10.13 

2.54 

38.64

.40

100. 00

75

F

27.50 

7.67 

25.87

.92

35.78 

1.91 

None. 

.07 

.28 

None. 

None.

100. 00 

.10, 427

G

30.40 

8.62 

19.77 

Trace. 

Present 

.01 

39.43 

1.50 

.03 

Trace. 

.14 

.10 

Trace.

100. 00 

22, 383

n

4.55 

7.64 

44.63 

.33 

Present 

.50 

24.17 

5.58 

5.58 

4.13 

2.89 

Trace. 

Trace.

100.00

484'

1 See Chatard's memoir on "natural soda" in Bull. U. S. Geol. Survey No. 60,1890. The nature of the 

product will be considered later in the chapter on saline residues.
160 DATA OF GEOCHEMISTRY.

Analyses of water from northern alkaline lakes Continued.

I. Silvies River, the chief feeder of Malheur Lake. Van Winkle, analyst. Average of 23 analyses ol 

composite samples of water, collected between October 12, 1911, and August 14, 1912.

J. Pelican Lake, Oregon. Van Winkle, analyst.

K. Bluejoint Lake, Oregon. Van Winkle, analyst. Pelican and Bluejoint lakes are in the Warner 

Lake basin. Analyses are also given of Crump, Hart, and Flagstaff lakes, all in the same group.

L. Silver Lake, in Christmas Lake basin, Oregon. Analysis by Van Winkle.

M. Soap Lake, Washington. Analysis by George Steiger, U. S. Geol. Survey Bull. No. 113,1893, p. 113. 

Another analysis by H. G. Knight is given in the previous editions of this work.

N. Moses Lake, Washington. Analysis by H. G. Knight, Ann Kept. Washington Geol. Survey, vol. 

1,1901,p. 295.

0. Omak Lake, Colville Indian Reservation, Washington. Analysis by Steiger in the laboratory of 

the Survey. Specific gravity, 1.004, at 25°.

P. Goodenough Lake, a shallow pond 28 miles north of Clinton, British Columbia. Analysis by F. G. 

Wait, Ann. Kept. Geol. Survey Canada, new ser., vol. 11,1898, p. 48 R.

ci. ...................

S04 .................

rr» (j(j3 ....... ...........

PO

B

r\ 4u7 ................

N03 - ...............

Na.......... ........

K.............. ......

Ca.. ...... ...........

Mg.. .................

8iQ~...... ...........

AI n

Fe2 03 ................

Salinity, parts per

I

2.88 

7.35 

34.76

.92 

10.42 

2.45 

12.88 

3.13 

25.13

.08

100. 00 

163

J

7.97 

22.09 

30.87 

.07 

Present 

.05 

29.25 

3.58 

2.27 

2.62 

1.21

.02

100. 00 

1,983

K

13.85 

5.67 

38.68 

.05 

Present 

.02 

37.70 

2.26 

.57 

.63 

.55

.02

100. 00 

3,640

L

0.87 

2.43 

47.48

.06 

U6. 36

11.07 

6.59 

15.04

.10

100. 00 

379

M

13.28 

16.44 

30.22

J39. 60

Trace. 

.04 

.42

100. 00 

28, 195

N

3.88 

2.87 

51.56

19.86

8.41 

7.25 

5.06

},n

100. 00 

2,966

0

2.96 

21.12 

36.75

None.

32.60 

4.52 

.23

1.82

100. 00 

5,704

P

7.64 

7.08 

41.41 

.62 

Trace.

36.17 

6.65 

.02 

.04 

.04 

.33

100. 00 

103, 470

All of these waters contain bicarbonates. Goodenough Lake 

deposits natron, Na2CO3 .10H2O, of which an analysis is given.1

A few saline lakes situated east of the Rocky Mountains have been 

studied to some extent. The analyses are as follows:

Analyses of water from saline lakes east of the Rocky Mountains.

A. Wilmington Lake, Wyoming. Analysis by E. E. Slosson, Bull. Wyoming Exper. Sta. No. 49,1901.

B. Big Lake.

C. Track Lake.

D. Red Lake. These three lakes are known as the Laramie or Union Pacific Lakes of Wyoming. They 

are usually dry, but in 1888 were filled with water. Analyses by H. Pemberton and G. P. Tucker, Jour. 

Franklin Inst., vol. 135,1893, p. 52.

E. Lake De Smet, Wyoming. Analysis by W. T. Schaller in the laboratory of the U. S. Geol. Survey. 

An analysis of its feeder, Shell Creek, was also made. See Water-Supply Paper No. 364,1914, p. 17.

F. Devils Lake, North Dakota. Analysis by H. W. Daudt, Quart. Jour. Univ. North Dakota, vol. 1, 

1911, p. 225. Reduced to standard form. Ca, 0.04; Si02,12.2; R203 , 4.0 parts per million.

G. Old Wives or Chaplin Lake, Saskatchewan, Canada. Analysis by F. J. Alway and R. A. Gortner, 

Am. Chem. Jour., vol. 37,1907, p. 3. Recalculated to 100 per cent from the original summation of 98.55.

1 Analyses by J. G. Smith of Summer, Christmas, Fossil, North Alkali, Middle Alkali, and South Alkali 

lakes, all in Oregon, are given in Bull. U. S. Dept. Agr., No. 61,1914, p. 80.
THE WATERS OF CLOSED BASINS. 161

Analyses of water from saline lakes east of the Rocky Mountains Continued.

Cl.................

S04 .. ..............

r\f) CO..................

B407 .. .............

Na.................

K... ...............

Ca..................

Mg. ...............

SiOa ................

A1203 -. ...........

PejO,.. .............

Salinity, parts per 

million.... .......

A

10.78

16.62

32.75

39.85

100. 00 

o 119. 700

B

8.85

58.16

2.03

27.00

.93

3.03

100. 00 

"52. 600

C

2.74

64.30

1.14

30.20

.53

1.09

100.00 

077, 300

D

3.06

64.57

.57

29.89

.59

1.32

100. 00 

o93. 100

E

0.90

64.15

5.14

20.85

1.27

1.10

6.32

.22

} .05

100.00 

6.708

F

10.45

54.07

4.24

25.88

Trace.

5.36

Trace.

100. 00 

11. 278

G

4 Q8

61. 86

1.54

30.65

Trnr-A

Trac-p

Q7

Tram

Trace.

100.00 

27. 300

o These figures for salinity of the Laramie Lakes have little or no significance, because the "lakes" vary 

from dry masses of salts to solutions of varying concentration. For additional information about them see 

L. C. Ricketts, Ann. Rept. Territorial Geologist Wyoming, 1888, p. 45; and A. R. Schultz, Bull. U. S. Geol. 

Survey No. 430, p. 570.

Five of these lakes are essentially solutions of sodium sulphate, and 

resemble certain bodies of water on the Russian s.teppes.

CENTRAL AND SOUTH AMERICA.

For the saline waters of Central and South America the chemical 

data are very scanty. Six analyses, however, may be cited here:

Analyses of saline waters from Central and South America.

A. Lake Chichen-Kanab ("little sea"), Yucatan. Analysis by J. L. Howe and H. D. Campbell, Am. 

Jour. Sci., 4th ser., vol. 2,1896, p. 413. Two samples were analyzed, and that from the middle of the lake 

is given below. The water deposits gypsum.

B. Lake Parinacochas, Peru. Analysis by G. S. Jamieson and H. Bingham, Am. Jour. Sci., ser. 4, vol. 

34, p. 12,1912.

C. Lake Huacachima, Peru. Analysis by E. Pozzi-Escot, Bull. Soc. chim., 4th ser., vol. 15,1914, p. 97. 

Traces of bromides, iodides, and thiosulphates are also reported. The analysis is obscurely stated, and the 

recalculation here is therefore somewhat uncertain.

D. Lagoon of Tamentica, Chile. See F. J. San Roman, Desierto i Cordilleras do Atacama, vol. 3, Santiago 

de Chile, 1902, p. 199.

E. Rio Saladillo, Argentina. Analysis by Siewert, reported by A. W. Stelzner, Beitrage zur Geologic 

und Palaeontologie der argentinischen Republik, 1885. Sample taken at Puente del Monte. The river 

mpties into the Laguna de los Porongos. It is salt during drought, nearly fresh in the rainy season. Stelzner estimates that it carries into the laguna, annually, 584,566,200 kilograms of salts. Stelzner also gives 

analyses by Docring of the Saladillo between Salta and Jujuy, and of Arroyo Salado in Patagonia.

F. Laguna de Epceu<5n, Argentina. Analysis by M. M. Leguizamon, Trabajos Cuarto Cong. cient. PanAmericano, vol. 4, Santiago, 1910, p. 258.

so4 .............. ...........

rn

NO

PO

T> f\ l^.v.v.v.'::::::::::::::::

Na................ ..........

K. .........................

Ca... ......................

Mg........ .................

SiOa .......................

Ala08 ......................

Fea08 ......................

Salinity, parts per million.. .

A

8.14

58.64

11.99

.43

13.49

7.31

100. 00 

4,446

B

46.87

10.59

2.16

.40

.05

1.36

32.64

3.83

1.18

.82

.07

.03

100. 00 

12, 059

C

11.18

16. 95

29.33

Trace.

Trace.

.12

36.54

4.52

.34

.63

.39

100. 00

(?)

D

50.44

9.17

2.14

35.35

2.29

.01

.60

100. 00 

285, 500

E

56.74

4.82

36. 40

1.63

.41

100. 00 

108, 250

F

42.96

17 1Q

o no

37.72

100.00 

285, 000

113750° 19 Bull. 69c
162 N DATA OF GEOCHEMISTRY.

CASPIAN. SEA... AND SEA OF ARAL.

The greatest of all the closed basins is that of the Caspian Sea,. 

which was formerly connected, through the Black Sea, with the general oceanic circulation. It is also probable that the Sea of Aral was 

at some time a part of the same great body of water, and therefore the 

two sheets are properly to be considered together. Many smaller 

saline lakes are scattered through the Caspian depression, some of 

them being recent concentrations from overflows, while others are of 

much older origin.1

The Caspian Sea, however, is something more than a segregated 

remnant of the ocean. Its water is diluted by the influx of the 

Volga, the Ural, and other important streams, so that its composition 

is intermediate between that of a river and that of the open sea. 

Its salinity is relatively low .and very variable. At the north end, 

near the mouth of the Volga, the water is only brackish; in the deeper 

southern portions it is much salter. On the eastern side of the Caspian there is a large gulf, the Karaboghaz, into which a current 

continually flows, through a shallow channel, with no compensating 

return. This current, it is estimated, carries daily into the gulf 

350,000 tons of salt; and therefore the salinity of the Karaboghaz is 

steadily increasing. Its waters no longer support animal life, and 

saline deposits are foftning upon its bottom. Near its margin 

gypsum crystals are formed; toward the center of the gulf sodium 

sulphate is deposited.2 The latter substance is thrown down only 

during the winter months, for at summer temperatures the Karaboghaz brine is an unsaturated solution. In cold weather it is saturated 

with respect to sodium sulphate, but not for the chloride, and the 

latter remains dissolved.3 The separation of salts by fractional 

crystallization is thus well exemplified.

To illustrate the composition of the Caspian and allied waters, a 

few analyses must suffice. The older data can be found in the works 

of Bischof and Roth. The following examples are fairly typical:

1 For-analyses of some of these waters, the Bogdo, Indersk, and Stepanova lakes, see Roth, Allgemeino' 

und chemische Geologic, vol. 1, p. 469. Modern and complete analyses are much to be desired; the old 

ones are unsatisfactory.

2Seo S. Kusnetsoff, Zeitschr. prakt. Geologie, 1893, p. 26.

s Sec N. S. Kurnakoff, Verhandl. Russ. k. rnin. Gesell., 2d ser., vol. 38, 1900, p. 26 of the proceedings'' 

For a long paper on the Karaboghaz, also known AS the Karabugas or Adschi-darja, see "W. Stahl, Ttfatur 

Wochenschr., vol. 20,1905, p. 689. This paper is based on an official Russian report by Spindler and Lebcdintzeff, published in 1902. For an analysis of water from Lake Durun in Transcaspia see A. S» achmann, 

Jahresb. Chemie, 1887, p. 2531.
THE WATERS OF CLOSED BASINS. 163

Analyses of Caspian and allied waters.

A. Caspian Sea. Mean of five analyses by C. Schtnidt, Bull. Acad. St. Petersburg, vol. 24,1878, p. 177.

B. Caspian Sea. Analysis by A. Lcbcdintzeff, cited by W. Stahl, Natur. Wochenschr., vol. 20, 1905, 

p. 6S9.

C. Karaboghaz Gulf. Analysis by Schmidt, loc. cit.

D. Karaboghaz Gulf. Analysissby Lebedintzeff, cited by Stahl, loc. cit.

E. Tinetzky Lake, a residue of concentration from the Caspian. Analysis by Schtnidt, loc. cit.

F. Sea of Aral. Analysis by Schmidt, cited from Roth, Allgemeine und chemische Geologic, vol. 1, p. 465. 

Schmidt's analyses report bicarbonatcs, which are here reduced to normal salts. I have also consolidated 

the insignificant quantities of silica, phosphoric acid, and ferric oxide, which wore determined separately.

G. Sea of Aral. Analysis by Stepanow, cited by S. Sowetow, Ann. Hydrog. und Marit. Mcteorologo 

1910, p. 658. Other recent analyses are also mentioned, probably from the monograph by L. Berg on tho 

Sea of Aral, published by the Russian Geographical Society, a work which I have not seen.

H. The River Atrek, a western tributary of the Caspian. Mean of two analyses by F. K. Otten, Jahrcsb. 

Chemie, 1881, p. 1442. Analyses of the tributary rivers Sumbar and Tschandyr are also given.

ci..................

Br...................

on

co8 ................

Na..................

K... ................

Kb.. ................

Ca...................

Mg. ................

SiO,, P04) Fe9 03 . ....

Salinity, per cent....

A

42.04

.05

23.99

.37

24.70

.54

.02

2.29

5.970*}

100. 00 

1.294

B

41. 78

.05

23.78

.93

24.49

- .60

2.60

' 5.77

100. 00 

1.267

c

53.32

.06

17.39

11.51

1.83

.06

15.83

100. 00 

28.50

D

50.26

.08

15.57

.13

25.51

.81

.'57

7.07

100. 00 

16. 396

E

47.99

.13

21.25

18.46

.24

.01

.01

11.91

100. 00 

28.90

F

35. 40

.03

30.98

.85

22.62

.54

.02

4.02

5.50

04

100. 00 

1.084

G

35.63

31. 27

.10

22.05

1.07

4.48

5.40

100. 00 

1.067

H

19.33

43.09

6.09

19.03

5.98

5.40

1.08

100. 00 

1.495

Analyses C and D show that the Karaboghaz varies from time to 

time, both in composition and in concentration.

With the exception of the Atrek and two other small streams, 

analyses of the rivers which feed the Caspian seem to be wanting; at 

least, I have found none recorded. They must have carried large 

amounts of calcium and of carbonic acid, which have been almost 

entirely eliminated. The falling off of sulphates and the concentration 

of magnesium in the more saturated waters is clearly brought out by 

the table, an order of change which will be considered more fully 

somewhat later. Both the Caspian Sea and the Sea of Aral differ 

chemically from the ocean in their higher proportions of calcium, 

magnesium, and sulphates.1

THE DEAD SEA.

In the water of the Dead Sea some of the phenomena of saline 

concentration are exhibited to an extreme degree. Sodium compounds have been largely eliminated, and the remaining brine resemi Bergotrasser, in Petermann's Mittheilungen, 1858, pp. 10i-105, has brought together 38 old analyses of 

salts from the lakes of Astrakhan and the mouth of the Volga. For an analysis of water from Lake Tinaksk, 

Astrakhan, see N. W. Sokoloff, Jour. Chem. Soc., vol. 100, ii, 1911, p. 502, abstract from Jour. Russian ' 

Phys.-Chem. Soc., vol. 43, p. 436. Analyses of water from the Syr-Daria and Amu-Daria, the chief feeders 

of the Sea of Aral, have been published in a report on the work of the Hydrometric Service in Turkestan, 

St. Petersburg, 1913.
164 DATA OF GEOCHEMISTRY.

bles in many respects the mother liquor left by ocean water after 

the extraction of salt. It is rich in magnesium, calcium, and bromine; 

the sulphates have been reduced to an insignificant amount, and carbonates are almost entirely lacking. The original solutions, however, from which the Dead Sea was formed were probably not identical in composition with those which produced the salinity of the 

ocean, and so the bittern of sea water differs from the brine that we 

are now considering. The two are similar, but not quite the same.

The water of the Dead Sea has been repeatedly analyzed, and the 

older data are reproduced in the works of Bischof and Roth. The 

best series of analyses is due to A. Terreil,1 and of his eight, six are 

given below in reduced form. They represent samples collected from 

different depths and different parts of the lake, and they show its 

variable character.

Analyses ofuaterfrom Dead Sea and River Jordan.

A. Surface water, north end of lake. Terreil.

B. At depth of 20 meters, 5 miles east of Wady Mrabba. Terreil.

C. At depth of 42 meters, near Ras Mersed. Terreil.

D. At depth of 120 meters, 5 miles east of Ras Feschkah. Terreil.

E. Same locality as D, at depth of 200 meters. Terreil.

F. Same locality as B, at depth of 300 meters. Terreil.

G. Analysis by J. B. Boussingault, Annales chim. phys., 3d ser., vol. 48, 1856, p. 129. Boussingault 

cites the earlier analyses of Dead Sea water.

H. Analysis by F. A. Genth, Liebig's Annalen, vol. 110,1859, p. 240.

I. Analysis by Roux, Compt. Rend., vol. 57,1863, p. 602.

J. Analysis by H. Fleck, Jour. Chem. Soc., vol. 42,1882, p. 24, abstract. Probably surface water.

K. Analysis by A. Stutzer and A. Reich, Chem. Zeitung, vol. 31,1907, p. 845.

L. Analysis by A. Friedmann, Chem. Zeitung, vol. 36, p. 147,1912. Specific gravity 1.1298. Mean of 2 

analyses.

M. Analysis by H. Fresenius, Zeitschr. angew. Chem., 1912, p. 1991. Specific gravity 1.1555 at 15°. The 

trace of iodine is 0.000247 gram per kilo, and of iron, 0.0007586 gram.

N. The Jordan near Jericho. Analysis by R. Sachsse, Inaug. Diss., Erlangen, 1896. Analyses of several 

smaller streams are given. Organic matter not included in the following table. An earlier analysis by 

Auderson is cited in the first edition of this book (Bulletin 330).

Cl.................. ..........

Br........ ...................

S04 ............. ..............

C08 .... .......................

Na.......... ..................

K. ...........................

Ca........... ................

Mg.. .........................

SiOa .........................

Salinity, per cent. .............

A

65.81

2.37

.31

Trace.

11.65

1.85

4.73

13.28

Trace.

100. 00 

19.215

B

70.25

1.55

.21

Trace.

6.33

1.70

5.54

14.42

Trace.

100. 00 

20. 709

C

68.16

1.99

.22

Trace.

10.21

1.00

1.53

16.89

Trace.

100. 00 

24. 263

D

67.66

1.98

.22

Trace.

10.20

1.62

1.51

16.81

Trace.

100.00 

24. 573

E

67.84

1.75

.22

Trace.

10.00

1.79

1.68

16.72

Trace.

100. 00 

25. 110

F

67.30

9 79

.24

Trace.

5.50

1.68

fi fU

15.92

T^QPA

100. 00 

25. 998

1 Compt. Rend., vol. 62,1866, p. 1329. Terreil also made an analysis of the water of the River Jordan, but 

stated it obscurely. In addition to the substances-named in. the table, Terreil reports traces of hydrogen 

sulphide, ammonia, alumina,.ferric oxide, and organic matter in the water of the Dead Sea.
THE WATERS OF CLOSED BASINS. 165 

Analyses of water from Read Sea and River Jordan Continued.

01..................

Br......... ..........

I...................

so4 . .................

003 ..................

N03 ..... .............

Na............. '.....

K...... ..............

NH4 .. ...............

Ca..... ..............

Mg............. ......

SiOa .. ...............

(Al, Fe)A-- ........

Salinity, per cent ....

G

65.80 

1.37

.13

11.22 

3.70 

Trace. 

5.69 

12.09

Trace.

100. 00

22. 7697

H

65.22 

2.08

.29 

.01

13.39 

2.37

4.79 

11.85

Trace.

100. 00 

22. 2834

I

65.43 

1.54

.20

11.70 

3.53 

Trace. 

5.60 

11.85

.15

100. 00 

20. 590

J

65.74 

1.48

.33

11.60. 

3.40

5.02 

12.42

100. 00 

21. 977

K

64.49 

1.45

.45

15.75 

3.24

4.09 

10.. 53

Trace.

100. 00 

22. 030

L

63.40 

1.69

.42 

Trace.

13.49 

3.24

5.74 

12.02

Trace.

100. 00 

23. 8906

M

65.86 

1.13 

Trace. 

.39 

.02

13. 73 

2.36

4.19 

12.32

Trace.

100. 00 

18. 8453

N

41.47

7.22 

13.11 

Trace. 

18.11 

1.14

10.67 

4.88 

1.95 

1.45

100. 00 

0.770

From the foregoing analyses we see that the water of the Dead Sea 

differs widely from all the other waters that we have examined. The 

composition of its main feeder, the Jordan, is also unusual. When it 

enters the Dead Sea, its carbonates and gypsum are precipitated, and 

its contribution to the lake brine is composed almost entirely of 

chlorides. The valley of the Jordan and the regions roundabout the 

Dead Sea contain m any beds of rock salt and gypsum, and the neighboring Cretaceous strata are impregnated with the same substances. 

From these sources the river derives its chlorides and sulphates, and 

so returns to the lake some products of its former concentration. Hot 

springs, also, as L. Lartet 1 and others have shown, contribute to the 

salinity of the waters. To some extent, probably, there is atmospheric 

transportation of salts from the Mediterranean, and W. Ackroyd 2 

regards this as a most important agency, although its influence is 

probably overestimated. Whatever may have been the origin of the 

Dead Sea, its water is now essentially a bittern, relatively low in 

sodium, high in magnesium, and remarkably rich in bromine. The 

brine from 300 meters depth carries over 7 grams of bromine to the 

liter, but only a trace of iodine has been detected in it.3

1 Bull. Soc. geol. France, 2d ser., vol. 23,1800, pp. 719-760.

2 Chem. News, vol. 89, 1904, p. 13.

a The following references to original authorities on the water of the Dead Sea are worth recording: J. 

Apjohn, Proc. Roy. Irish Acad., vol. 1,1841, p. 287; B. Silliman, jr., Am. Jour. Sci., 1st ser., vol. 48,1845, 

p. 10; T. J. and W. Herapath, Jour. Chem. Soc., vol. 2,1849, p. 337; A. F. Boutron-Charlard and 0. Henry, 

Jour, pharm. chim., March, 1852; R. M. Murray, Proc. Glasgow Philos. Soc., vol. 3,1852, p. 242; J. C. Booth 

and A. Muckle, Am. Jour. Sci., 2d ser., vol. 19,1855, p. 149; F. Moldenhauer, Liebig's Annalen, vol. 97,1856, 

p. 357; Schwarzenbach, Mitt, naturforsch. Gesell. Berne, 1870, p. 47. An analysis by J. H. Salisbury (Am. 

Poly tech. Jour., vol. 2,1853, p. 374) of what purported to be- Dead Sea water was evidently of ocean water. 

The earlier analyses by A. Marcet, Klaproth, Gay-Lussac, and C. G. Gmelin have only historical interest. 

A recent analysis by Mitchell (Berg- u. hiittenm. Zeitung, 1902, p. 225) is of doubtful value.
166 DATA OF GEOCHEMISTRY.

OTHER RUSSIAN AND ASIATIC I.AKES.

Mother liquors having a general similarity to the Dead Sea brine 

are also furnished by the Elton Lake, in southern Russia, and the 

Red Lake, near Perekop, in the Crimea. Their analyses, recalculated 

from the figures given by Roth, appear in the next table. The composition of the Elton water varies with the season of the year, and 

I have selected an analysis which represents its concentration in 

August. In spring its tributaries, swollen by melting snow, bring in 

much sodium chloride and alter its character materially. Analyses 

of water from several Asiatic lakes are included with these in the

following table.

Analyses of Russian and Asiatic waters.

A. Elton Lake, Russia. Anatysis by Erdmann, cited by Roth, Allgemeino und chemische Geologic, 

vol. 1, p. 409.

B. Eed Lake, Perekop, Crimea. Analysis by Hasshagen, from Roth, op. cit., p. 471. Roth gives analyses of several other Crimean salt lakes. Analyses of four Crimean lakes are given by A. Goebel, M61. 

chim. phys., vol. 5,1SG4, p. 320.

C. Lake Van, Armenia. Analysis by E. de Chancourtois, Compt. "Rend., vol. 21, 1845, p. 1111. Carbonates reduced to normal salts.

D. Lake Urmi or Urmiab, Persia. Analysis by li. T. Giinther and J. J. Manley, Proc. Roy. Soc., vol. 

05,1899, p. 312.

E. Salt Lake near Shiraz, Persia. Analysis by K. Natterer, Monatsh. Chcmie, vol. 10,1895, p. 658.

F. Gaukhane Lake, southern Persia. Analysis by A. Heider, published by Natterer, op. cit., p. C73.

G. Koko-Nor, Tibet. Analysis by C. Schmidt, Bull. Acad. St. Petersburg, vol. 24,1878, p. 177. Eicarb onates reduced to normal salts. Sample taken in autumn, 1872.

H. Koko-Nor, Tibet. Analysis by Schmidt, He'1. chim. phys., St. Petersburg, vol. 11, 1881, p. 487. 

Sample taken in the winter of 1880, from under thick ice. For analysis of three saline lakes in Central 

Asia, see Schmidt, idem, vol. 12,1887, p. 547.

Cl..................

Br.................

I...................

S04 .................

CO,.. ..............

Na..................

K. .................

Rb. .................

NH4 .. ...............

Ca.. .................

Mg.. ...............

Si02 .. ...............

FP O

PO

Salinity, per cent. . . .

A

64.22

6.82

.04

11.27

.10

17.55

100. 00 

26.50

B

66.82

.03

.11

19.32

.58

2.01

11.13

100. 00 

30.01

C

27.08

11.95

20.71

37.65

1.19

.57

.85

Trace.

100. 00 

2.10

D

57.33

5.06

33.98

.78

M

2.53

100. 00 

14.85

E

58. 17

.01

3.48

.23

35.51

 .29

.61

.46

1.84

100. 00

7.77

F

59. 67

1.29

37.38

.82

.83

.01

100.00

25.88

G

40.05

.04

17.84

5.55

30.60

1.08

.04

1.77

2.90

.09

.02

.02

100. 00 

1.11

II

41.69

.04

16.30

6.66

28.64

.81

.04

Trapp

.04

5.66

.08

.02

.02

100.00 

1. 30

The general resemblance of analyses A and B to those of Dead Sea 

water is evident. Elton Lake, however, contains a notable proportion of sulphates, which are entirely wanting in the Crimean water. 

Lake Van is alkaline, and its saline composition is much like that^of - Mono Lake in California, except that it is less concentrated. Lake
THE WATERS OF CLOSED BASINS. 167

Urmi is of the same type as Great Salt Lake, and the two other 

Persian waters are similar. The Koko-Nor belongs in the same class 

with the Caspian and the Sea of Aral, but it contains a much larger 

proportion of carbonates.

In the neighborhood of Minussinsk and Abakansk, government of 

Yeniseisk, Siberia, there are a number of saline lakes or ponds which 

have been studied by F. Ludwig.1 The reduced analyses, arranged 

in the order of their chlorine, are as follows:

Analyses of water from saline lakes of Yeniseisk, Siberia. .

A. The Kisil-Kul.

B. Lake Schunett, water collected in 1899. Another analysis, of a sample collected in 1898, gave similar 

but somewhat different results, and showed much greater concentration. This latter sam pie had a salinity 

of 25.35 per cent, and its salts contained 0.19 per cent of bromine.

C.. Lake Tagar..

D. LakoBeisk.

E. Bitter Lako.

E. Lake Altai.

G. Lake Biljo. This is the largest of the lakes and measures about (30 kilometers in circumference.

II. Lake Domoshakovo.

Cl..................

Br. ................

SO...................

C03 . ...............

Nf)

Na.... ..............

K.. ................

Ca.................

Mg. ................

Si02 . ..............

A1203 - ............

Fe203 ..............

Salinity, per cent. . . .

A

48.28

Trace.

14.55

.22

34.01

.35

.69

1.86

.04

Trace.

100. 00 

10.87

B

38.89

32.19

.31

16.12

.33

.44

11.67

.01

.04

100. 00 

15. 19

G

29.52

Trace.

34.99

1.55

28.41

1.01-

.27

4.12

.04

.09

100. 00 

2.09

D

22.79

Trace.

! 42. 32

. 61

31.32

1.01

.07

1..86

.01

.01

TVflpp

100. 00 

10.47

R

20. 02

43. 83

1.53

31.78

1.38

.15

1.28

.03

Trace.

100. 00 

5.90

F

14.38

50.14

1.12

32. 83

.52

.05

.90

.03

.02

.01

100. 00 

10.88

C!'

9.91

52.33

6.22

1.07

21.83

.87

.43

7.28

.03

.03

100. 00

.88

H

3.71

TVi PO

63.62

.08

.07

30. 61

.59

.58

.74

Trace.

Trace.

100.00 

14.55

The last analysis in this table, that of Lake Domoshakovo, represents essentially a solution of sodium sulphate, with very little else. 

It is the extreme type of a sulphate water. The other waters upon 

evaporation, yield mixtures of chlorides and sulphates, sodium being 

the dominant electropositive radicle. In one analysis only is magnesium high; in two others it is important. The calcium is insignificant 

throughout the series.

A number of other Siberian lakes have been investigated by C. 

Schmidt, from whose memoirs the following analyses,, reduced to 

standard form, have been selected. 2 

i Zoitschr. prakt. Geologic, vol. 11, 1903, p. 401. Ludwig also gives analyses of sedimonts and saline 

deposits from these waters.

* In Mem. Acad. St. Petersburg, vol. 20, No. 4,1873, Schmidt gives analyses of 14 bitter, salt, and fresh 

lakes on the line from Omsk to Petropavlovsk, and thence to Prasnowskaja.
168 DATA OF GEOCHEMISTRY.

Analyses of water from Siberian lakes.

A. Issyk-Kul. M61. phys. chim., St. Petersburg, vol. 11, 1882, p. 623. 

B. Iletsk salt lake, government of Orenberg. Op. cit., vol. 11,1882, p. 603. Average. 

C. Barchatow bitter lake, 300 versts southwest of Barnaul, government of Tomsk. Op. cit., vol. 11, 

1882, p. 609. 

D. Buliiktu-Kul or Fish Lake, Kirghiz Steppe. Op. cit., vol. 12,1883, p. 37.

Cl............................................

Br.. ........... ................................

S04 ..... ......................................

rn

PO

Na......... ...................................

K. ...........................................

Ca..... ........ ................................

Mg.... .......................................

Fe.. ............................................

Si02 .... ....... ................................

S, sulphide. ....................................

Salinitv. r>arts per million. ......................

A

15.64

.03

55.94

1.26

.02

11.76

1.85

.94

12.50

.06

100. 00 

3.574

B

60.26

Trace.

.47

38.86

Trace.

.33

.08

100. 00 

155. 230

C

45.05

.11

20.23

28. 01

.36

5.84

.50

100. 00 

13. 308

D

Q7 Oft

04

27.29

qa

oq OQ

.32

5.28

4 fiR

.06

100. 00 

11. 458

MISCELLANEOUS LAKES.

In the next table I give reduced analyses of several European lakes 

of widely varying character. They are as follows:

Analyses of water from European lakes.

A. Lake Laach, Germany. Analysis by G. Bischof, Lehrbuch der chemischen und physikalischen 

Geologic, 2d ed., vol. 1,1863, p. 316. This lake occupies the crater of an extinct volcano, and its water is 

fresh. It is, nevertheless, an alkaline water and yields sodium carbonate on evaporation.

B. Palic Lake, Banat, Hungary. Analysis by K. von Hauer, Jahrb. K.-k. geol. Reichsanstalt, vol. 7, 

1856, p. 361. Iron, magnesium, and calcium are held in solution as bicarbonates, and are precipitated on 

boiling. Free carbonic acid and organic matter are also present.

C. Hive's or Medve Lake, near Szovata, Hungary. Analysis by B. von Lengyel, Foldt. Kozl., vol. 28, 

1898, p. 280. Recently formed by a sinking of the ground. The neighboring country contains salt deposits.

D. Lake Ruszanda, Hungary. Analysis by J. Schneider, cited by A. Kaleczinzky, Foldt. Kozl., vol. 28, 

1889, p. 284. The data as published show discrepancies which detract from their value. Organic matter 

omitted.

E. Lake Tekir-Ghiol, Rumania. Analysis by Popovici, Saligny, and Georgesco, cited by P. Bujor, 

Ann. sci. Univ. Jassy, vol. 1,1901, p. 158. A lake of about 1,140 hectares, situated only 300 to 400 meters 

from the Black Sea. The published summation of the analysis is not in accord with the individual figures.

F. Lacu Sarat, Rumania. Analysis by Carnot, cited by Bujor, op. cit., p. 176. In winter this lake 

deposits crystallized sodium sulphate, mirabilite, NaaSOi.lOHaO. In a memoir entitled " Apercu g6ologique sur les formation saliferes et les gisements de sel en Roumanie," Bucharest, 1902, L. Mrazec and 

W. Teisseyre cite analyses of Lacu Sarat, Lacu Fundata, Lacu Amara, and Lacu lanca. They also give 

analyses of Rumanian salt.

Cl............................

Br... ........................

S04 .. .........................

C03 ...... ....................

N03 . ...... ...............°...

PO

NH4 ....... ...................

Na............................

K........ ....................

Ca... ........................

Mg....... ....................

A1203 -- ....... ...............

FeA---- ....................

Si02 .........................

Salinity, parts per million. ....

A

4.99

2.97 

50.97

27.05

9.90

2.77

1.35

100. 00

218

B

15.68

2.92 

41.02

35.75

.66 

3.35

.35 

.27

100.00 

2,215

C

60.18 

Trace. 

.44 

.04

39.02

.25 

.03

Trace. 

.04

100. 00 

233, 747

D

19.07

22.56 

19.22

.52

37.07 

1.19 

.20 

.15

JTrace. 

.02

100. 00 

6,276

E

60.53 

.18

.67 

Trace. 

Trace.

Trace.

34.78 

1.68 

.28 

1.84

1 .03 

.01

100. 00

70, 877

F

28.25

37.12 

.27

31.75

.39 

2.16

} - -.02 

.04

100.00 

58, 038
THE WATERS OF CLOSED BASINS. 169

Illye's Lake and the neighboring Black Lake are essentially strong 

solutions of common salt, formed by the leaching of salt beds. According to A. Kaleczinzky,1 they have warm layers under a "freshwater surface, which owe their increased temperature to the absorption of solar heat and to the fact that brine has a lower specific heat 

than water. The surface layer of Black Lake has a temperature of 

21°; the warm layer below reaches 56°. These lakes, therefore, are 

accumulators of heat.

With the analyses of six more lake waters, the present tabulation 

must close. They are as follows:

Analyses of saline lakes in Africa, India, and Australia.

A. Natron Lake, near Thebes, Egypt. Analysis by E. Willm, Compt. Rend., vol. 54,1862, p. 1224. No 

bromine, iodine, nitrates, or sulphates were detected.

B. Salt Lake 32 kilometers north of Pretoria, Transvaal. Described by E. Cohen, Min. pet. Mitt., vol. 15, 

1895, pp. 1, 194. Analysis, incomplete, by H. Hopmann. This lake or salt pan is about 400 meters in 

diameter and occupies a funnel-shaped depression in granite.

C. The Katwee Salt Lake, north of Albert Edward Nyanza, central Africa. Analysis by A. Pappe 

and H. D. Richmond, Jour. Soc. Chem. Ind., vol. 9,1890, p. 734.

D. Sambhar Salt Lake, Rajputana, India. Analysis by W. A. K. Christie, Rec. Geol. Survey India, 

vol. 38,1909, p. 167. Traces of NH«, Fe, S, B03 , P0<, and I were also found. For the origin of the salt 

in this lake see ante, p. 148.

E. Lonar Lake, Berar district, Central Provinces, India. Analysis by T. H. D. La Toucho and W. A. 

K. Christie, Rec. Geol. Survey India, vol. 41,1912, p. 266. Traces of borates detected.

F. Lake Corongamite, Victoria, Australia. Analysis by A. W. Craig and N. T. M. Wilsmore, Fourth 

Rept. Australasian Assoc. Adv. Sci., 1892, p. 270.

Cl.... ........................

Br.... .......................

S04 .. .........................

S.. ...... . ..................

C03 ..... .....................

Na.. ..........................

K... .........................

Ca...........................

Mg................... ........

(A^FeJaO.... ..................

Si02 .. ......................

Salinity, parts per million. ....

A

26.00

32.90

31.05

3.57

3.62

1.50

1.36

100. 00 

4,407

B

43.47

.03

15. 17

41.33

100. 00 

211, 400

C

36.67

12.33

10.42

33.46

7.09

Trace.

Trace.

.03

100. 00 

310, 000

D

"52. 96

.04

5.85

2. i9

38.86

.09

Trace.

.01

Trace.

100. 00

(?)

E

40.76

1.48

.01

17.63

39.60

.11

.01

Trace.

.40

100. 00 

82, 872

F

59.32

99

1.65

Undet.

35.07

.84

10

2.77

100.00 

46, 039

SUMMARY.

With the evidence now before us it is easy to see that the waters of 

salt and alkaline lakes may be classified in a few fairly well defined 

groups. First, we have a group of chloride waters, characterized 

mainly by sodium chloride, which may be regarded as belonging to an 

oceanic type. In the following table these waters are summed up in

1 Ueber die ungarischen warmen und heissen Kochsalz-Seen, etc., Budapest, 1902. An analysis by 

Hanko of the Black Lake is given. It is practically identical with that of Illye's Lake; the salinity is 19.53 

percent. See also F. Schafarzik, Foldt. Kozl., vol. 38, 1908, p. 437.
DATA OF GEOCHEMISTEY.

the order of diminishing chlorine, only the.main constituents being 

.given:

Principal constituents of chloride waters.

Lake Tekir-Ghiol. . ............

Tloi'dli' T olro

Hive's Lake. ...................

Gaukhane Lake. ..............

Lake Corongamite ............

Lake near Shiraz ................

Rio Saladillo. ................

Great Salt Lake (average). . ....

Ocean.................. ......

Cl, Br.

60.71

60.26

60.18

59.67

59. 54

58.18

57.33

56.74

55.73

55.48

53.00

S04 .

0.67

.47

.44

1.29

1.65

3.48

5.06

4.82

6.61

7.69

5.85

CO3 .

Trace.

0.04

(?)

.23

Trace.

.21

2.19

Na, K.

36.46

38.86

39.02

37.38

35.91

35. 80

34.76

36.40

35.16

31.70

38. 95

Ca.

0.28

.33

.25

.82

19

.46

.32

1.63

.32

1.20

Mg.

1 84

.08

.03

00

2 T7

1 84

2.53

.41

2.28

3.72

.01

These analyses suggest, if they do not actually prove, a similarity 

of origin for all these bodies of water, and a possible derivation, 

direct or indirect, from a primitive ocean. Some of the lakes were 

formed by leaching masses of oceanic salts which were deposited in 

earlier geologic ages; others are doubtless remnants of oceanic overflows or segregations. In the leaching process the alkaline chlorides 

dissolved more freely than other salts, and so became concentrated in 

the newer waters. K. Natterer,1 in his discussion of the Persian 

salt lakes, suggests that differing diffusibility may have played a 

part in the concentration of sodium chloride. As the leaching waters 

percolated through the soil, the more diffusible alkaline chlorides 

would be partially separated from the less active calcium and magnesium salts, and would reach the lake reservoir in larger quantities. 

The composition of Lake Tekir-Ghiol, which is closely adjacent to 

the Black Sea, would seem to emphasize this suggestion. In it the 

alkaline chlorides are concentrated, while the other constituents of 

sea water are present in much less than the normal amounts.

In direct relation to waters of the preceding group are the derived 

waters of the bittern type. In these, by prolonged evaporation, 

magnesium salts are concentrated, sodium chloride having crystallized out. The three waters available for comparison are as follows:

Principal constituents of natural bitterns..

«

Dead Sea (average) ............

Red Lake. . ................... 

Elton Lake. ...................

Cl, Br, I.

68, -15

66. 96 

64.22

SO*.

0.28

""6."82"

C03 .

Trace.

"'6.' 64"

Na, K.

13.55

19.90 

11.27

Ca.

4.37

2.01 

.10

Mg.

13. 62

11.13 

17.55

1 Monatsh. Chcmie, vol. 16,1895, p. 666.
THE WATERS OF CLOSED BASINS. 171

From the chloride waters we pass by slow gradations to the sulphate type, as shown in the following condensed analyses. Between 

the two groups there is no distinct line of demarcation.

Principal constituents of chloro-sulphate waters.

Sevicr Lake. . .................

Tamentica Lagoon. ............

Kisil-Kul....................

Lagoon of Epecue"n ...........

Lake Beisk. ..................

Bitter Lake ..................

Lake Altai. ...................

Old Wives Lake. .............

Ci, Br.

52.66

50.44

48.28

46.87

42.96

29.52

28.25

22.79

20.02

14. 38

4.98

4.88

3.71

S04 .

10.88

9.17

14.55

10.59

17.19

34.99

37.12

42.32

43.63

50.14

61.86

62.34

63.62

C03 .

0.22

2.16

2.13

1.55

.27

.61

1.53

1.12

1.54

.08

Na, K.

33.33

37.64

34.36

36.47

37.72

29.42

31.75

32.33

33.16

33.35

30.65

29.03

31.20

Ca. .

0.12

.01

.69

1.18

97

.39

.07

.15

.05

.68

.58

Mg.

Q fil

f>n

1.86

.82

4 19

2.16

1.86

1.28

.90

.97

1.81

.74

Some of these waters have been modified by human agency, which 

utilized them as sources of salt. They form, nevertheless, a natural 

series, in which the alkaline radicles are nearly constant in proportion, while the chlorides and sulphates vary reciprocally. Lake De 

Smet, a sulphate water from which chlorides are nearly absent, 

might be placed at the end of this series were it not for the small 

proportion of carbonates that it contains.

A slightly different composition is represented by a subgroup of 

sulphate-chloride waters, as shown by the analyses of the Caspian, 

the Sea of Aral, and two smaller lakes.

Principal constituents of sulphato-chloride waters.

Barchatow bitter lake. . .......

Buluktii-Kul .................

Sea of Aral. . ..................

Cl, Br.

45.16

41. 96

38.00

35.43

so*.

20.23

23.88

27.39

30.98

CO3 .

0.65

no

.85

Na, K.

28.27

25.16

oq ci

23.18

Ca.

2 44

5

OQ

4 0?

Mg.

5.84

5 Q7

4.68

5 Cft

Here we have a dilution of oceanic water by sulphate-bearing tributaries, with a falling off of the alkaline metals and an increase in 

calcium and magnesium. The bitterns derived from these waters 

differ from the normal bitterns in respect to their proportion of sulphates, but otherwise they represent the same order of changes. I 

include with them the Schunett Lake of Siberia, which has analogous composition, and also the Issyk-Kul.
172 DATA OF GEOCHEMISTRY.

Principal constituents of sulphato-chloride bitterns.

Karaboghaz Gulf (average) ....

T^i TI P'f'7 lr"\7 T ,*} ITP

Cl, Br.

51.86 

48.12

38.89

15.67

'S04.

16.48 

21.25

32.19

55.94

C03 .

0.07

.31

1.26

Na, K.

18.33 

18.70

16.45

13.61

Ca.

0.28 

.01

.44

.94

Mg.

11.45 

11.91

11.67

12.50

The water of Lake Chichen-Kanab in Yucatan is also a sulphatochloride water, but it stands alone as the only known member of a 

distinct subgroup. Its dominant kation is calcium.

The alkaline lakes that contain notable quantities of carbonates 

are less easy to classify than the foregoing waters, and yet some 

analogies are clear. First, we have a number of analyses in which 

the carbonates are largely in excess of all other salts, as follows:

Principal constituents of carbonate waters.

Moses Lake ..................

Malheur Lake-. ..............

Goodenough Lake. ............

Palic Lake. ..................

Cl, Br.

0.87

3.88

4.55

4.99

7.64

7.68

15.68

S04 .

2.43

2.87

7.64

2.97

7.08

13.24

2.92

C03 .

47.48

51.56

44.63

50.97

41.41

37.79

41.02

Na,K.

16.36

19.86

29.75

27.05

42.82

41.08

35.75

Ca.

11.07

8.41

5.58

9.90

.02

.66

Mg.

6.59

7 ^l

4.13

2.77

04

q qc

In the next group of waters carbonates and chlorides predominate, with sulphates in subordinate quantity.

Principal constituents of carbonate-chloride waters.

Bluejoint Lake. ..............

Summer Lake ................

Natron Lake. .................

Humboldt Lake. . .............

Abert Lake (average) .........

Lonar Lake. . .................

Cl, Br.

13.85

18.27

26.00

28.95

31.82

32.31

36.13

40.76

41. 04

43.47

47.88

S04 .

5.67

4.18

8.14

3.27

.13

1.90

1.48

5.25

.03

3.76

CO3 .

38.68

35.57

32.90

22.82

21.57

22.47

90 73

17.63

14.28

15. 17

7.93

Na, K.

39.96

41.07

31.05

39.31

36.51

39.62

40. 62

39.71

35.95

41. 33

38.62

Ca.

0

^7

Trace

3.57

.01

1.35

.03

.01

.25

.55

" Mg.

0.63

TWpp

3.62

.04

1.88

.36

Trace

Trace.

2.28

.49

Borax Lake, which also contains 5.05 per cent of B4O7 in its saline 

residue, might well be put in a class by itself; but extreme subdivision 

is not now desirable.
THE WATERS OF CLOSED BASINS. 173

- Two of the waters are conveniently classed as sulphate-carbonates, 

as follows:

Principal constituents of sulphato-carbonate waters.

Omak Lake ..................

Pelican Lake. ................

*

Cl, Br.

2.96

7.97

so*.

21.12

22.09

CO3 .

36.75

30.87

Na, K.

37.12

32.83

Ca.

O oq

9 97

Mg.

1.82

9 fi9

In the following waters, which are of the "triple" type, chlorides, 

sulphates, and carbonates are all present in notable quantities:

Principal constituents of "triple" waters.

&

Tulare Lake .................

Lake Ruszanda . .............

Walker Lake. .................

Cl, Br.

10.78

13.28

11.18

25.30

23.34

27.08

20.26

19.07

23.77

35.95

36.67

S04.

16.62

16.44

16.95

9.92

12.86

11.95

20.77

22.56

21.29

10.42

12.33

CO3 .

32.75

30.22

29.33

23.59

23.42

20.71

19.55

19.22

17.34

14.83

10.42

Na, K.

39.85

39.60

41.06

39.88

39.78

38.84

38.21

38.26

34.83

36.00

40.55

Ca.

TYflpp

0.02

.04

.28

90

.90

Mg.

0 04

<u

.01

.10

K7

9fi

1 f\

1.56

99

Finally, there are three waters which might be classed with the sulphato-chlorides were it not for their moderately alkaline character.

Principal constituents of water of Lake Biljo, Devils Lake, and Koko-Nor.

Lake Biljo ...................

Devils Lake. . ................

Koko-Nor. ...................

Cl, Br.

9.91

10.45

40.09

S04 .

52.33

54.07

17.84

C08 .

6.22

4.24

5.55

Na, K.

22.70

25.88

31.72

Ca.

0.43

Trace.

1.77

Mg.

7.28

5.36

2.90

In general, as was pointed out in discussing the Lahontan waters, 

alkaline lakes are representative of volcanic regions, while saline 

lakes are associated with sedimentary deposits. That is, from a 

chemical point of view the alkaline waters are the newest, and exhibit 

the nearest relationship to rivers and springs. By the weathering 

of rocks carbonates are first formed, as is seen in most rivers near 

their sources. Under favorable conditions these .salts accumulate, 

and they are transformed into or replaced by other compounds only 

after a -long and slow series of chemical reactions. In recently 

formed bodies of water, derived from igneous rocks, carbonates are 

abundant; but as salinity or concentration increases, the slightly
174 DATA OF GEOCHEMISTEY.

soluble calcium carbonate is thrown down, leaving sulphates and 

chlorides in solution. If more calcium is available, gypsum is precipitated, and the final result is a water containing little except 

chlorides. The carbonate waters form the beginning, the chloride 

waters the end of the series. When calcium is deficient in quantity, 

then mixed waters are" produced, in which alkaline sulphates, carbonates, and chlorides may coexist in almost any relative proportions. Waters of mixed type may also be formed by the blending of 

supplies from different sources, and the contributions of two tributaries may be very unlike. The fresh decomposition products from 

a volcanic rock and the leachings of sedimentary beds are widely 

dissimilar; but the chemical changes consequent upon their commingling will follow the order just laid down. This order can not be 

stated in quantitative terms, for the conditions of equihbrium in 

complex mixtures are not definitely known. The solubility of a salt 

in pure water is one thing; its solubility in the presence of other 

compounds is something quite different; and when the number of 

possible substances is great the problem becomes hopelessly complicated. Each substance influences every other substance, in a 

manner which depends partly upon temperature and partly upon 

concentration, and no known equations can cover the whole field.

Qualitatively, however, the conditions governing the deposition 

of salts can be simply and intelligibly stated. Suppose we consider 

a solution so dilute that it contains ions capable of forming t}he chlorides, sulphates, and carbonates of sodium, calcium, and magnesium, 

which are the chief salts derivable from natural waters. Upon concentration, the difficultly soluble carbonates of calcium and magnesium will be precipitated first, to be followed by the slightly soluble 

gypsum. Next in order sodium sulphate and carbonate will form, 

and these salts are deposited by many saline or alkaline waters. 

Later, sodium chloride and magnesium sulphate .may crystallize out, 

leaving at least a bittern containing the very soluble chlorides of calcium and magnesium. This is the observed order of concentration, 

but every step is not necessarily taken in every instance. All of the 

calcium may be eliminated as carbonate, leaving none for the formation of other salts. All of the sulphuric ions may be taken to produce 

gypsum, and then no sodium sulphate can form. In short, the actual 

changes which take place during the concentration of a specified water 

depend on the proportions of its constituents, and vary from case to 

case. The proposed order of deposition is simply the general order, 

which conforms to the facts of observation and to the known solubilities of the several salts. The least soluble possible salt will form 

first; the most soluble will remain longest in solution. The formation 

of double salts will be considered in another chapter.
CHAPTER VI.

MINERAL WELLS AND SPRINGS. 

DEFINITION.

Between the so-called "mineral waters" and waters of ordinary 

character no sharp line of demarcation can be drawn. In fact, 

some of the springs having the greatest commercial importance 

yield waters of exceptionally low mineral content and owe their 

value to their remarkable purity. They are simply potable waters 

carrying a minimum of foreign matter in solution. Other springs, 

on the contrary, are characterized by excessive salinity, and 

between the two extremes nearly every intermediate condition may 

be observed.

In the chapter on lakes and rivers a number of springs were 

considered which represent the ordinary or common type of water 

supply. Rain water, charged with carbonic acid, percolates through 

the soil or through relatively thin layers of rock and emerges with 

a moderate load of dissolved impurities. Upon evaporation such 

waters give a residue consisting most commonly of calcium carbonate, 

calcium sulphate, or silica, with minor amounts of alkaline chlorides, 

and, blending with rain or seepage waters, they form the beginnings 

of streams. Sometimes sulphates predominate, sometimes carbonates, but chlorides are present much less conspicuously. Calcium is 

the dominating metal, and sodium occupies, as a rule, a subordinate 

place. To the vast majority of spring waters these statements 

apply, but here and there exceptions are encountered which, by 

their peculiar characters, attract attention and -are known as 

"mineral" wells or springs. Speaking broadly, all springs are 

mineral springs, for all contain mineral impurities; but in a popular 

sense the term is restricted to waters of abnormal or unusual composition. A mineral water, then, is merely a water which differs, 

either in composition or in concentration, from the common potable 

varieties. The term is loose and indefinite, but it has a certain 

convenience, and we may use it without danger of being led astray.

To put the case differently, a mineral spring may be described as 

one which owes its character to local as distinguished from widespread or general conditions; and the peculiarities thus acquired 

may result from a great variety of causes. One water, rising from 

beds-of salt, is charged with sodium chloride; another represents 

the solution of gypsum; a third may carry substances derived

175
176 DATA OF GEOCHEMISTRY.

from the sulphides of metalliferous veins, and so on indefinitely. 

Any soluble matter existing in the crust of the earth may find its 

way into the waters of a spring and give to the latter some distinguishing peculiarity. Even in their gaseous contents spring 

waters differ widely. Some are heavily charged with carbonic acid 

and effervesce upon reaching the air, and others contain hydrogen 

sulphide in sufficient quantities to be recognized by the smell. 

Some waters are strongly acid, some alkaline, and some neutral; 

waters emerging from beds of pyritiferous shale are often rendered 

astringent by salts of aluminum or iron; one spring is boiling hot 

while its neighbors are ice cold; in short, every difference of origin 

may be reflected in some peculiarity of composition or character. 

In recent years many mineral springs have been found to contain 

appreciable quantities of argon, helium, and the other inert gases, 

a fact which bears upon the radioactivity exhibited by natural 

waters. For example, G. Massol,1 in the gas from the thermal 

spring of Uriage, France, found 0.932 per cent of helium, together 

with krypton and xenon. Argon was detected in the hot springs 

of Bath, England, shortly after the element was discovered.2 In 

the boric acid sojjioni of Tuscany, helium and argon were found by 

R. Nasini, F. Anderlini, and R. Salvadori.3 Many French springs 

have been studied, with similar results, by C. Moureu and 

R. Biquard.4 These minor characteristics of natural waters can 

not be dwelt upon more fully here.

CLASSIFICATION.

The classification of waters can be based on a variety of considerations. It may be geologic, correlating the springs with their geologic 

origin, or as ancient or modern, or by dividing them into classes 

according to their derivation from rain water or from sources deep 

within the earth; it may be physical, drawing a chief distinction 

between cold and thermal springs; or chemical, in which case differences of composition determine the place which each water shall 

occupy. To a great extent the three systems of classification overlap, and each one depends more or less on the others; but for the 

purposes of this memoir, which deals with chemical phenomena, 

the chemical method is obviously the most appropriate. The other 

considerations must, of course, be taken into account; but chemical 

composition is, for us, the determining factor. From this point of

1 Compt. Eend., vol. 151,1910, p. 1124.

2 See Rayleigh and Ramsay, Zeitschr. phys. Chemie, vol. 16,1895, p. 362. Also Rayleigh, Proc.Roy, 

Soc., vol. 59,1896, p. 198.

8 Gazz. chim. ital., vol. 28,1898, p. 81.

< Compt. Rend., vol. 143,1906, p. 795; vol. 146,1908, p. 435. See also Moureu,idem, vol. 142,1906, p. 1155, 

and in Revue sci., 1914, p. 65, for a thorough-review of the whole subject.
MINERAL WELLS AND SPRINGS. 177

view the classification of springs is comparatively simple and follows 

the lines laid down in the preceding chapters. Waters are classed 

according to their negative radicles, as chloride, sulphate, carbonate, 

or acid waters, with various mixed types and occasional examples in 

which unusual combinations, such as nitrates, borates, sulphides, or 

silicates, appear. The classification, however, can not be rigid, and 

to a great extent convenience must govern and modify the usual 

rules. Mixtures such as we have now to consider can not be arranged 

according to any hard-and-fast system, but must be dealt with somewhat loosely. The general relationships are simple and evident, but 

the exceptional cases are common enough to modify any formal 

scheme of arrangement that might be adopted.

CHLORIDE WATERS.

The literature relating to mineral springs is extremely voluminous, 

and the recorded analyses are numbered by thousands. From such 

a mass of material only typical or striking examples can be utilized 

here in order to show the variations in composition which have 

been observed. As the chloride waters form perhaps the most conspicuous group, we may properly begin with them and consider first 

the solutions which upon evaporation yield principally sodium chloride. . Waters of this class are very common, and range from potable 

springs to brines resembling sea water in saline composition. From 

such brines common salt is commercially obtained, and the subjoined table gives analyses of several important examples.1 The 

figures represent the composition of the anhydrous saline matter contained by the several waters, each analysis being reduced from the 

.original form of statement to percentages of ions.

1 In Ann. Eept. Geol. Survey Canada, vol. 15,1902-3, p. 236 S, 0. C. Hoffman gives 12 analyses of brines 

from Manitoba. A brine from a well 1,920 feet deep, at Sand Beach, Michigan, analyzed by S. P. Duffield 

(Geol. Survey Michigan, vol. 5, pt. 2,1895, p. 82), is unusually rich in bromine. J. W. Turrentine, U. S. 

Dept. Agr., Bur. Soils Bull. No. 94,1914, gives many analyses of American brines and bitterns. For the 

brines of Silver Peak Marsh, Nevada, see R. B. Dole, U. S. Geol. Survey Bull. No. 530, pp. 331-345,1913.

113750° 19 Bull. 695 12
178 DATA OF GEOCHEMISTRY.

Analyses o/natural brines.

A. Brine:froia Syracuse-, New Yorkl Average of four analyses by C. A.'G'oessmann>published iaDana's 

System.'ol mineralogy, 6th ed.,.p. 156.

B. Brine from Warsaw, New York. Analysis by F, E. Engelhardt, Bull. New York State Mus. No. II, 

1893> p. 3S. Many other, analyses are given in this publication.

C. Brine from East Saginaw, Michigan. Well 806 feet deep. Analysis by Goessmann, Geol. Survey 

Michigan, vol. 3', 1873-1876, p. 183.

D. Brine from Poraeroy, Ohio. Analysis by C. W. Fault, Bull. Ohio; Gcol. Survey No. 8,, 1906, p. 27- 

The trace of iodine represents 0.004. gram Nal per liter.

E. Humboldt salt \vell, Minnesota. Analysis by C. F. Sid'ener, Ann. Kept. Geol. Survey Minnesota, 

vol. 13,. 1884,. p; 101.

F. Brine from Hutchinson, Kansas. Analysis by E. H. S. Bailey and E. C. Case, Univ. Kansas Geol. 

Survey, vol. 7,1802, p. 79.

G. Artesian- well, Abilene,.TIansa3. Analysis by B. EL S'. Bailey and E. B. Porter, Univ. Kansas Geol. 

Survey, vol. 7,. 1902, p. 130. Well,. 1,2CO feet deep.

H. Bryan's well, Bistineau, Louisiana. Analysis by M. Bird, Report on geology of Louisiana, 1902, 

p. 40. Many other analyses of salines are given in this volume. The brines are of Cretaceous origin.

CL. ..................

Br

I.....................

S04 ...... ...........

/i/Vciv.. ......................

PO

Ni*

K.. ....................

Ca.......... .........

ST....................

Ba. ..................

Mg... ................

Mn.. ................. Fe"

Fe-iO,.. ...............

AI203 .. ..............

SiOj........ ..........

Other solids...........

Salinity, per cent. . . .

A

58. 85

.01

2. 29

.01

37. 29

.03

1.28

.23

.01

100.00 

16. 8.4

B

59; 71

1.19

38.38

.67

.05

100, 00 

26, 34

C

' 61. 27

.52

' 32. 76

4.25

1.20

100. 00> 

20. 24

D

61. 59

.13

Trace.

None.

1 31. 51

: .06

: 4.91

 .14

; ,21.

1.36

| .08

.01

100. 00 

10. 52

E

55. 96

, 4.18

1.68

Trace.

32.56

.6ft

2.71

1:80

.02

.07

.36

100, 00

. 5.. 72.

F

59. 60

1.33

38. 38

.55

.11

.03

100,00 

; 29. 31

G

; 61. 65

.29

Trace.

.07

; 31. 57

Trace.

4.85

, 1 52

Trace.

: .05

iTrace.

100.. 00 

17.. 89

H

K,n or;

07 on

9Q

.63

.98

100.00 

8.93

Most if not all of the foregoing brines were formed by solution from 

beds of rock salt., The latter undoubtedly originated from the 

evaporation of salt lakes or sea water, and in. geological age they 

range from the Cretaceous down to the upper Silurian. The New 

York brines are from Silurian deposits. The Humboldt well is 

nearest to ocean water in composition, although it is nearly twice as 

concentrated. In general, the proportion of sodium chloride is 

greater than in sea salts, for the reason that that compound redissolves more readily than the gypsum which was deposited with it. 

The process of deposition and re-solution thus tends to separate the 

constituents of the original water; and so the composition of the 

ancient lake or ocean is not exactly reproduced.
MINERAL WELLS AND SPRINGS. 179

The following analyses also represent the salts from chloride waters 

in which sodium is largely the predominant base:

Analyses of chloride waters I.

A. Cincinnati artesian well, Cincinnati, Ohio. Analysis by E. S. Wayne, cited by A. C. Peale, in Bull. 

U. S. Geol. Survey No. 32,1888, p. 133. This water contains considerable quantities of free H£S and COj.

B. Upper Blue Lick Spring, Kentucky. Analysis by J. F. Judge and A. Fennel, cited by Peale, op. cit., 

p. 111. Also rich in HzS and CO:. I represent here by X an indeterminate mixture of CasPzOe, A1203, and 

FojOs. For later analyses of the Blue Lick springs, by R. and A, M. Peter, and for analyses of other 

mineral waters in Kentucky, see Chase Palmer, Water-Supply Paper U. S. Geol. Survey No. 233, 1909, 

pp. 184-215.

C. Montesano Springs, Missouri. Analysis by P. Schweitzer, Geol. Survey Missouri, vol. 3, 1892, p. 77. 

This volume contains many analyses of Missouri mineral waters.

D. Deep well at Brunswick, Missouri. Depth 1,505 feet. Analysis by Schweitzer, op. cit., p. 97. 

E. Utah Hot Springs, 8 miles north of Ogclen, Utah. Temperature 55° C. Analysis by F. W. Clarice. 

Bull. U. S. Geol. Survey No. 9,188-1, p. 30.

F. Spring at Pab.ua, New Zealand. Analysis by W. Skey, Trans. New Zealand Inst., vol. 10, 1877, p. 

423. This spring is notable from the fact that it contains free iodine. According to J. A. Wanklyn (Chem. 

News, vol. 54,1886, p. 300) the water of Woodhull Spa, near Lincoln, England, has the same peculiarity.' 

The iodine colors the water brown and can be extracted by carbon bisulphide.

In analyses D and F the bicarbonate^ of the original statement have been reduced to normal salts.

Cl.......... ..................

Br............................

I, combined . . ...............

S04 .........................

C08 ..........................

PO

Na. .........................

K.... ........................

Li...........................

Ca...........................

Mg........ ...................

Al ..........................

A1203 ............ ............

Fe".. ........................

Fe203 .. ......................

SiOa .... .....................

X...... ......................

Salinity, parts per million. . . .

A

55.83

.04

.03

3.12

2.63

33.09

.27

3.72

1.13

.06

.08

100. 00 

10, 589

B

53.08

.51

.02

6.03

2.34

31.47

.96

3.56

1.57

.16

.30

100. 00 

11, 068

C

57.38

.31

5.37

28. 17

.15

6.15

2.30

.17

100. 00 

8,509

D

52. 74

8.36

1.88

30.15

4.74

2.09

.04

100. 00 

15, 905

E

58.79

Trace.

.94

.61

30.38

3.76

Trace.

4.90

.40

.02

.20

100. 00 

23, 309

F

60.78

Trace.

.04

.11

.15

.17

.05

34.81

.02

3.14

.60

.01

Trace

.12

100. 00 

21, 060
180 DATA OF GEOCHEMISTRY.

Analyses of chloride waters I Continued.

G. Water of Salsomaggiore, Italy. Analysis by R. Nasini and F. Anderlini, Gazz. chim. Hal., vol. 30, 

i, 1900, p. 305. Contains in 1,000 grams 0.00223 gram Mn and 0.00792 gram B^O;. These are less than 0.01 

percent of the total solids.

H. The Marienquelle, Bavaria. Analysis by A. Lipp, Ber. Deutsch. chem. Gesell., vol. 30,1897, p. 309. 

Contains also much free CO2 .

I. The Kochbrunnen, Wiesbaden, Germany. Analysis by C. R. Fresenius, Jahrb. Nassau. Ver. Naturkunde, vol. 50,1897, p. 20. This water also contains 0.000013 gram iodine, 0.00002 gram PO^and 0.00018 

gram AsO< to the liter, each recorded here as a "trace." For other analyses of Wiesbaden waters see the 

same journal, vol. 49, 1896, pp. 22, 23.

J. Water of Arva-Polhora, Hungary. Analysis by W. Kalmann and M. Glaser, Min. pet. Mitt., vol. 

18,1898-99, p. 443. Organic matter, about 0.15 per cent, is excluded from the reduced statement heregiven.

K. Old sulphur well, Harrogate, England. Analysis by T. E. Thorpe, Jour. Chem. Soc., vol. 39,1881, 

p. 500. The memoir contains some other analyses.

L: Chloride of Iron Spa, Harrogate. Analysis by C. H. Bothamley, Jour. Chem. Soc., vol. 89, 1881, p. 

502. The same author, in vol. 63, 1883, p. 685, gives analyses of waters from Askern, Yorkshire.

Cl............................

Br......... .................. i............................:

F. ..........................

S04 .........................

s. ..........................

C03 .... ...... ................

PO

As04 .. .......................

B

/-v 4O7 ........................

B02 .. ........................

Na. .........................

K............ ................

Li...........................

NH4 ....... ..................

Ca............. ..............

Sr.... ........................

Ba........... ................

Mg..................... ......

Mn. .......................... Fe"

Fe203 -------- ................

Al ..........................

Cu...........................

Si02 .........................

Salinity, parts per million. . . . .

G

61. 09

.15

.03

.18

34.04

.07

.12

3.21

.24

.82

.03

.01

.01

100. 00 

159, 000

H

52.72

.42

.54

Trace.

7.66'

Trace.

Trace.

33.08

Trace.

Trace.

4.i5

1.34

.09

Trace.

100. 00 

2,970

I

56.58

.04

.78

3.13

Trace.

Trace.

.01

32. 60

1.16

.04

.07

4.05

.12

.01

.61

} .04

.76

100. 00 

8,241

J

58.76

.37

.14

.12

1.07

.02

.72

36.18

.42

.22

i. io

.34

.08

.29

.14

.03

100. 00 

30, 150

K

58.81

.19

.01

Trace.

.23

2.12

Trace.

33.61

.48

.01

.03

2.65

Trace.

.42

1.37

Trace.

.07

100. 00 

14, 800

L

60.83

.07

Trace.

.02

1.23

23.45

.35

Trace.

.03

7.28

.07

.76

3.12

.10

2.39

Trace.

.30

100. 00 

6,617

Although sodium chloride is the principal salt obtainable from the 

waters represented by the preceding analyses, they owe their interest 

to other things. They have been selected from the great mass of 

published material in order to show the extent to which substances 

like bromine, iodine, sulphur, lithium, barium, strontium, and iron 

occur in waters of this class.1

To these minor constituents the therapeutic value of mineral waters 

is commonly ascribed, but to considerations of that sort no attention 

can be paid here. The last analysis given, that of the Chloride of

1 For the common occurrence of Sr, Ba, Mn, As, etc., in mineral springs see J. C. Gil, Rev. Acad. cl. 

Madrid, vol. 8,1909, p. 131. See also W. W. Skinner and W. F. Baughman, Jour. Ind. Eng. Chem., vol. 

9,1917, p. 18. On selenium in mineral waters see F. Taboury, Bull. Soc. chim., 4th ser., vol. 5,1909, p. 865.
MINERAL WELLS AND SPRINGS. 181

Iron Spa at Harrogate, is interesting as marking a transition to 

another group of chloride waters, in which the proportion of sodium 

is decreased and large quantities of calcium appear. Sometimes 

magnesium is also abundant; for example, in salts from the group 

of springs at Kapouran, Java, S. Meunier 1 found 54.2 per cent of 

calcium chloride and 40.65 per cent of magnesium chloride. The 

following analyses are characterized by the presence of calcium in

large proportion: 2

Analyses of chloride waters II.

A. Brine from well 2,667 feet deep at Conneautsville, Pennsylvania. Analysis by A. E. Robinson and 

C. F. Mabery, Jour. Am. Chem. Soc., vol. 18,1896, p. 915. A little H2S is present.

B. Well at Bowerman's mills, Whitby, Canada. Analysis by T. Sterry Hunt, Geology of Canada, 1863, 

p. 547. Analyses of other waters are given in this memoir.

C. Water from well 192 feet deep, Manitoulin Island, Lake Huron. Analysis by T. Sterry Hunt, Chemical and geological essays, 1875, p. 158.

D. Water from the Silver Islet mine, Lake Superior. Analysis by F. D. Adams, Ann. Rept. Oeol. 

Survey Canada, new ser., vol. 1,1885, p. 17 M.

E. Water from the lower level of the Quincy mine, Hancock, Michigan. Analysis by G. Steiger in the 

laboratory of the United States Geological Survey.

F. Water from boring on Kanab Creek, near Port Haney, British Columbia. Analysis by F. G. Wait, 

Ann. Rept. Gcol. Survey Canada, vol. 5, ii, new ser., 1890-91, p. 22 R.

G. Boiling spring at Savu-Savu, Fiji. Analysis by A. Liversidge, Proc. Roy. Soc. New South Wales, 

vol. 14,1880, p. 147. Part of the aluminum in this water is reported as Aids and part as Al2 0s.

H. Water from People's Natural Gas Well, 8 miles southwest of Imperial, Washington County, Pennsylvania. Specific gravity, 1.211. Depth of well when sample was taken, 6,300 feet. Analysis by G. Steiger 

in the laboratory of the Survey.

ci.................

Br...... ..........

I..................

so...............

CO................

PO

Na..... ..........

K.. ...............

Li................

NH

Ca.. ........ ......

Sr.......... .......

Mg... .............

AT.................

Al O

Fe"

FeA-... .........

Mn, Co........'...

SiOa .. ............

Salinity, parts per 

million.... .....

A

62.31

.53

.01

03

.27

18.35

1.55

. .04

.23

13.86

2.53

.02

.25

.02

100. 00 

309, 175

B

64.43

.41

Trace.

.09

16.17

Trace.

13.68

Trace.

5.22

Trace.

.......

100. 00 

46, 300

C

64.45

8.71

1.92

20.67

.425

-------

100. 00 

21, 660

D

61.57

.13

.48

18.33

.67

17.46

1.21

None.

None.

Trace.

.15.

100.00 

36, 000

E

63.55

.01

.01

None.

5.63

None.

30.78

.01

.01

100. 00 

212, 300

F

63. 39

Present.

None.

5.27

.42

30.89

.03

........

100.00 

48, 500

G

57.91

3.38

Trace.

Trace.

16. 65

.93

18.34

.0440

.54

Trace.

1.78

100. 00 

7,813

H

61.38

.26

Trace.

.02

24.50

1.97

9.56

1 31

.94

.06

.......

100. 00 

263, 640

» Compt. Rend., vol. 103, 1886, p. 1205.

8 See also the analysis of brino from a well at Alma, Michigan, by C. F. Chandler and C. E. Fellow, Geol. 

Survey Michigan, vol. 5, pt. 2,1894rp. 46. Also one of water from the Freda well, Koweenaw Point, Michigan, by G. A. Konlg, Rept. State Board Geol. Survey Michigan, 1903, p. 165. In the deep-seated waters 

around Lake Superior calcium chloride seems to be an important constituent. These waters have been 

carefully studied by A. C. Lane, Jour. Canadian Min. Inst., vol. 12,1909, p. 114, and Proc. Lake Superior 

Min. Inst., 1908, p. 63.
182 DATA OF GEOCHEMISTRY.

The water represented by analysis H is remarkable for its high proportion of strontium 3.55 grams per kilogram, equivalent to 6.8 grams 

of SrCla per liter. A trace of barium was also detected in the water.

The next table contains analyses of waters belonging to the chloride 

group, but in which notable quantities of other acid radicles are also 

present. The chlorine, however, predominates.

Analyses of chloride waters III.

A. Congress Spring, Saratoga, New York. Analysis by C. F. Chandler, cited by A. C. Feale in Bull. 

U. S. Geol. Survey No. 32,1880, pp. 38, 39.

B. Hathorn Spring, Saratoga, New York. Analysis by Chandler, loc. cit. For recent analyses of the 

Hathorn and twelve other Saratoga waters, see J. K. Haywood and B. H. Smith, Bull. Bur. Chemistry 

No. 91, U. S. Dept. Agr., 1905. For 5 more analyses see L. R. Milford, Jour. Ind. Eng. Chcm., vol. 6, 

1914, p. 207.

C. Franklin artesian well, Ballston, New York. Analysis by Chandler, op. cit., p. 33. These waters 

(A, B, and C) are all reported as containing bicarbonates, which in the present tabulation are reduced to 

normal salts. They all effervesce because of their large content in free C02 . The P04 in A and C amounts 

to 0.01 grain per gallon.

D. Artesian well at Louisville; Kentucky. Analysis by J. Lawrence Smith, cited by Peale, op. cit., 

p. 115. Bicarbonates reduced to normal salts. Lithium is reported as 0.02 grain per gallon.

E. Steamboat Springs, Nevada. Analysis by W. H. Melville, given by G. F. Becker in Mon. TJ. S. 

Geol. Survey, vol. 13,1888, p. 349. Bicarbonates reduced to normal salts. The "trace" of iron represents 

0.14 part per million. From a geological point of view this water is out of its proper classification. It is 

a volcanic water, whereas the other waters in the table arc of sedimentary origin.

F. Lansdowne well, Cheltenham, England. Analysis by T. E. Thorpe, Jour. Chem. Soc., vol. 65, 

1894, p. 772. The "trace" of bromine is 0.3 part and that of iron 0.1 part per million.

G. The Stanislawaquellc, near Karbdorf, Galicia. Analysis by Von Dunin-Wasowicz and J. Eorowitz, 

Chem. Centralbl., 1899, pt. 2, p. 491. Bicarbonates reduced to normal salts. The NOg amounts to 0.02 

part per million. One kilogram of this water contains 2.157232 grams of free C02 and 0.10665 gram of 

organic matter.

ci...................

Br.... ...... ........

I....................

F...... ..............

S04 ... ...............

s..... ...............

C03 .. ...............

NO

PO

B407 .. ..............

Na...................

K... ................

Li....................

Ca... .................

Sr...... .............

Ba. .................

Mg..................

Mn..................

Fe"_................

Pe-jOg. ..............

Al?..3.... ............

AI n

As. .................

Sb........ ...........

Eg..................

Si02 .. ................

Salinity, parts per 

million........

A

42.00

1.13

.02

Trace.

.08

18.59

Trace.

Trace.

27.62 v.78

.08

6.03

Trace.

.09

3.41

.03

Trace.

.14

100. 00 

12, 022

B

42.42

.16

.02

Trace.

19.28

Trace.

Trace.

27.29

' .68

.16

5.69

Trace.

.12

3.92

.07

.07

.17

100.00 

15, 238

C

41.95

.3V

.02

Trace.

.04

18.66

Trace

Trace.

28.84

1.83

.07

5.04

Trace.

.06

2.95

.07

nq

.07

100. 00 

20, 315

D

48.03

.05

.04

14.93

.49

OQ

29.84

.41

Trace.

3.75

2.19

.02

.06

.10

100. 00 

15, 700

E

35.00

4.58

.22

5.08

03

8.88

30.35

3.79

.27

.25

.01

Trace.

.01

.10

.02

Trace.

11.41

100. 00 

2,850

F

38.01

Trace.

Trace.

20.89

4.22

Trace

.

32.80

.72

Trace.

1.85

1 37

Trace.

Trace.

Traop

.14

100. 00 

8,870

G

34.60

} .02

.82

19.96

Trarp

37.29

CO

.01

3.64

1.44

.82

.01

.17

.69

100.00 

7,639
MINERAL WELLS AND SPRINGS. 183

STJUPHATE WATERS.

The sulphate waters, or the waters in which S04 is the principal 

negative ion, fall, like the chloride waters, into several groups, which 

shade one into another hy imperceptible gradations. Among potable 

waters of this class, those which upon evaporation yield chiefly calcium sulphate are by far the most common. Many examples of such 

waters were cited among the analyses of rivers. As a rule, on account 

of the slight solubility of gypsum, their salinity is relatively low. 

Waters of this type are frequently found in so-called mineral springs. 

Other waters of medicinal significance are essentially solutions of 

magnesium sulphate or sodium sulphate; still others contain sulphates of aluminum or iron, and a small group of waters, derived 

from the oxidation of sulphides, carry heavy metals in considerable 

quantity. Examples of these different classes are given below, and 

some sulphate waters which contain free acids will be considered in 

a special group later. % The following analyses are sufficient for present purposes:

Analyses of sulphate waters. .

A. Abilena well, 14 miles northwest of Abileno, Kansas, 130 feet deep. Analysis by E. H. S. Bailey 

Univ. Cool. Survey Kansas, vol. 7,1902, p. 166. The "traces" refer to 4 parts Nos and 3.2 parts Fo per 

million of water.

B: Spring near Denver, Colorado. Analysis by L. G. Eakins, Bull. TJ. S. Geol. Survey No. 60,1890, 

p. 174. Contains 210 parts of free C02 per million.

C. Cottage well, Cheltenham, England. Analysis by T. E. Thorpe, Jour. Chem. Soc., vol. 65,1894, p. 772. 

Contains 0.2 part of Fe per million.

D. Bitter spring at Laa, Austria. Analysis by A. Kauer, Jahrb. K.-k. geol. Reichsanstalt, vol. 20,1870, 

p. 118. Contains free C02 .

E. Waterfrom Cruzy, Herault, France. Analysis published by Braconnier, Annales dos mines, 8th ser., 

vol. 7,1885, p. 143. From a well 14 meters deep in an old gypsum quarry. The fissures around the well 

are lined with fibrous epsonu'te.

F. St. Lorenzquelle, Louk, Switzerland. Analysis by G. Lunge and K. E. Schmidt, Zeitschr. anal. 

Chemio, vol. 25,1886, p. 309. Contains O.OG part Li, 0.05 part Na, 0.05 part Fe, and 0.11 pare Mn per million in each case less than 0.01 per cent of the total solids.

Cl............................

S04 .........................

C08 ..........................

NO

ruPO 4 . ........................

As...........................

Na. .........................

K.................... ........

Li...........................

NH

Ca...........................

ST.... ........................

Ba..... ......................

Mg........ ...................

Mn.......... .................

Fe"............ ..............

Fe203 .... ....................

Ai^J Am3 . .......................

Cu...... .....................

SX>t.;. ......................

Salinity, parts per million. ....

A

0.48

66.28

.60

Trace.

30.46

1.08

.67

.41

Trace.

.02

100. 00 

74, 733

B

2.62

72.56

11.23

.22

Trace.

.53

12. 79

Trace.

Trace.

.05

100. 00 

60, 584

C

6.56

57.42

6.48

.02

13.51

.48

Trace.

.01

8.33

7.03

Trace.

Trace.

.16

100. 00 

5,518

I)

0.57

69.87

4.75

2.99

.35

.22

7.63

13.18

} .02

.42

100. 00 

62, 371

E

3.73

74.16

.03

4.50

.03

.02

17.45

.61

.07

100. 00 

101, 000

F

0.34

65.86

3.74

Trace.

Trace.

1.50

.30

Trace.

Trace

23.55

.05

TVflpp

3.07

} .0!

.03

Trace.

1.55

100. 00 

1, 948
184 DATA 0.1? GEOCHEMISTRY.

Analyses of sulphate waters Continued.

. G. Spring at Srebrenica, Bosnia. Analysis by E. Ludwig, Min. pet. Mitt., vol. 11,1889-90, p. 303; 1.37 

per cent of free HsSO4 has been here added to the figure for the SO* radicle. A little organic matter (11.2 

parts per million) is also present. On p. 308 of the same volume Ludwig gives an analysis of an acid water 

rich in aluminum sulphate from Biidos, Transylvania. Other papers in the volume give a number of 

important analyses of springs in Bosnia and Transylvania. Some waters containing unusual amounts of 

strontium are mentioned in Kept. State Board Geol. Survey Michigan, 1905, p. 555.

H. Alumwell, Versailles, Missouri. Analysis by P. Schweitzer, Geol. Survey Missouri,vol. 3,1S92, p. 131.

I. Water from Roncegno, southern Tyrol. Analysis by M. Glaser and W. Kalmann, Ber. Deutsch. 

chem. Gesell., vol. 21,1888, p. 2879. For a later analysis of Roncegno water see R. Nasini, M. G. Levi, and 

F. Ageno, Gazz, chim. ital., vol. 39 (2), 1909, p. 481. They cite another analysis by P. Spica.

J. Arsenical spring, S. Orsola, southern Tyrol. Analysis by C. F. Eichleiter, Jahrb. K.-k. geol. Reichsanstalt, vol. 57,1907, p. 529. The trace of Ni is 0.003 per cent.

K. Spring on Shoal Creek, 4J miles west of Joplin, Missouri. Analysis by W. F. Hillebrand, Bull. U. S. 

Geol. Survey No. 113,1893, p. 49. Total CO2 free and combined, 120.5 parts per million. A trace of lead 

is also reported. The water of Spring River, in eastern Kansas, also contains zinc, derived from the drainage of adjacent mines. See E. H. S. Bailey, U. S. Geol. Survey Water-Supply Papers Nos. 273, 351,1911.

CL. .......-....................;.....

S04 ........... ........................

C03 .. ................................

PO

H3AsOl4 .. .............................

AB02 ... ..............................

Na........ ............................

K............... .....................

Li...................................

Ca. ..................................

Mg.. .................................

Mn.... ................................

Fe"

Fe"'....-. ........... .................

Al........ ............................

Co.....................................

Ni. ..................................

Cd....... ............................

Zn...................................

Cu... ................. ................. Q-in

Salinity, parts per million. ............

G

0.48

65.33

Trace.

.41

.31

.32

Trace.

3.00

1.48

.12

24.98

1.21

.30

.36

1.70

100. 00 

1,723

H

76.57

1.19

5.82

3.39

4.28

7.36

1.39

100. 00 

3,303

I

0.03

70.93

.23

1.93

1.25

93

7.08

.93

.78

.03

11.09

3.09

.17

.41

.06

.15

1.61

100. 00 

8,150

J

0.33

71.84

.75

.14

.21

.10

6.32

.97

.24

1.76

10 AQ

3.05

TVanA

.01

1 1Q

100. 00

7,683

K

0.48

52.76

8.00

.67

.46

11.32

.71

.42

.11

.08

.10

22.31

.04

9 ^4.

100.00 

540

The Roncegno and S. Orsola waters evidently derive their saline 

constituents from metallic sulphides, apparently in great part from 

arsenical pyrites. Arsenical waters are not uncommon, and some of 

them contain enough arsenic to be poisonous. The water from Shoal 

Creek represents the oxidation of zinc blende, together with some 

reaction upon the adjacent limestones, from which its calcium and 

carbonic ions were obtained. It is essentially the same thing as a 

mine water, although it is not derived from any artificial opening. 

For comparison, three analyses of mine waters, carried out in the 

laboratory of the Geological Survey, are appended. Two of them are 

zinc waters; the third is a strong solution of copper sulphate". Such ' 

waters play an important part in the leaching and reprecipitation of 

ores and will be more fully considered later.
MINERAL WELLS AND SPRINGS. 185

Analyses of mine waters.a

A, B. Two mine waters from the Missouri zinc region, analyzed by H. N. Stokes. Two similar waters 

from the same region were analyzed by C. P. Williams, Am. Chemist, vol. 7,1877, p. 246.

C. Water from the Mountain View mine, Butte, Montana. Analysis by W. F. Hillebrand. Specific 

gravity, 1.1317 at 15° C. Contains, in parts per million, 3.5 Ni, 4.0 Co, 6.8 E, and 1.5 P0<.

Cl.....................................................

so

PO

As04 . ... :.............................................

Na. ..................................................

K. ....................................................

Li....................................................

Ca................... :................................

Mg.. ..................................................

Mn. ................................................... Fe"

Ni....................................................

Co....................................................

Zn.... ................................................

Cu... ......................................:..........

Cd... .................................................

Al. ....................................................

Si02 . .................................................

Salinity, parts per million. .............................

A

0.16

64.47

1.14

.10

Trace.

14.38

1.36

' .08

6.49

10.74

Trace.

.02

.20

.86

100. 00

4,232

B

0.03

63.26

.50

Trace.

TV n~np

3.55

.26

.02

4.88

94 Sfi

.04

.09

1.46

1.11

100. 00

9,754

C

0.01

60.29

Trace.

Trace.

ft4

Trace.

Trace.

.26

.13

.01

.04

Trace.

Trace. 07

38.72

.07

.06

100. 00 

117, 850

a For other analyses of mine waters see Chapter XV of this memoir.

Two other examples of intermediate waters, containing both sulphates and chlorides, but with the former in excess, may be cited 

here. Both are from Indiana, and the analyses are by W. A. Noyes.

Analyses of sulphato-chloride waters.

A. King's mineral spring, near Dallas. Twenty-sixth Ann. Bept. Indiana Dept. Geology, 1901, p. 32. 

Contains traces of Al, Fe, Ba, Sr, Li, Mn, Ni, Zn, Br, PO*, and B^O;. This volume contains an elaborate 

report upon the mineral waters of Indiana, in which many other analyses are cited.

B. West Baden Spring. Op. cit., p. 109. Contains traces of Al, Fe, Ba, Sr, Li, Br, I, P0<, and B^O?. 

Also32.5 parts of IfrS per million of water.

ci............................................................

so4 ...........................................................

C03 .. ..........................................................

Na. ...........................................................

K............................................................

Ca... ..........................................................

Mg...........................................................

QiO

Salinity, parts per million. ...........................................

A

11.10

59.68

1.67

13.89

.49

2.91

10.19

.07

100. 00 

15, 682

B

18.19

46.66

4.11

11, 72

.78

13.16

C 01

.17

100. 00

4 417
186 DATA OF GEOCHEMISTRY. : 

GARB ON ATE WATERS.

The carbonate waters, those in which C03 or HC03 is the principal 

negative ion, fall into two main subdivisions, calcium being the important base in one and sodium in the other. A large number of 

lake and river waters, as we Have already seen, belong to the first of 

these groups, and so do many springs of the usual potable type; 

waters of the second group, however, are not uncommon. In most of 

these waters the carbonic acid present is sufficient to form bicarbonates a condition which renders it possible for calcium, magnesium, 

and iron to remain in solution. Upon evaporation of such waters, 

CaC03 and MgC03 are deposited, while the ferrous bicarbonate is 

broken up, and insoluble F^Og, or some corresponding hydroxide, is 

formed by oxidation. The anhydrous residue in such cases contains 

no bicarbonates, but the latter may exist when sodium is predominant. The salt NaHC03 is moderately stable. On account of these 

peculiarities, which characterize the carbonate waters, it seems best 

to state their analyses in two ways one with bicarbonate ions (when 

they are given) in terms of parts per million, the other in percentages 

of anhydrous residue, as in all the preceding tables. Each form of 

statement has its advantages, but the second method gives the best 

comparison between different waters. The following analyses represent waters of the carbonate type:1

Analyses of carbonate loaters.

A. McClelland well, Cass County, Missouri. Analysis by P. Schweitzer, Geol. Survey Missouri, vol. 3,

1892. p. 181.

B. Artesian water, La Junta, Colorado. Wel 1386 feet deep. Analysis by W. F. Hillebrand in the laboratory of the United States Geological Survey.

C. Ojo Caliente, near Taos, New Mexico. Analysis by Hillebrand, Bull. U. S. Geol. Survey No. 113,

1893. p. 114. Traces of As, NOs, Ba, NH4, and possibly I, were found. For the geologic relations of Ojo 

Caliente see W. Lindgren, Econ. Geology, vol. 5,1910, p. 22.

D. The Grande-Grille, Vichy, France. Analysis by 3. Bouquet, Annalcs chim. phys., 3d ser., vol. 42, 

1854, p. 304. Analyses of other Vichy waters and their sediments are given in this memoir.

E. Spring at Hikutaia, Puriri, district of Auckland, New Zealand. Analysis by W. Skey, Trans. New 

Zealand Inst., vol. 10,1877, p. 423.

F. Excelsior Springs, Missouri. Analysis by W. P. Mason, Chem. News, vol. Cl, 1890, p. 123. This 

swater is notable for the relatively large amount of manganese which it contains.

G. Spring in Pine Creek valley, near Atlin, British Columbia. Analysis by F. G. Wait, Ann. Kept. 

Geol. Survey Canada, 1900, p. 49 R. This water deposits hydromagnesite and calcareous tufa.

H. Wilhelmsquelle, Karlsbrunn, Austrian Silesia. Analysis by E. Ludwig, Min. pet. Mitt., vol. 4,1882, 

p. 182.

1 Some interesting carbonate waters from Colorado are described by W. P. Headden in Am. Jour. Sci., 

4thser., vol. 27,1909, p. 305.
MINERAL WELLS AND SPRINGS. 187

Analyses of carbonate waters Continued.

I. Parts per million of water.

01.........

I... ....!..

P.....'.....

S04 .. ......

s.. ........

C03 . ......

HC03 .......

Pft

As04 ......

T> f\ E407 . ......

Na. ........

K. ........

Li..........

Ca..........

Sr .........

Mg. .......

Mn ........

Fe" .......

FeaCv 

Al O

Si02 .. ......

A

94

88

1

1.287

581

4

2

19

2,069

B

66.9

71.1

791.5

668.7

6.4

Trace.

4.4

2.5

Trace.

2.4

3.4

51.0

1, 668. 3

c

231.4

5.2

151.0

1, 095. 9

.2

Tvflpp

4.2

995.7

31.4

3.4

22.8

1.4

9.5

1.6

.5

60.2

2, 614. 4

D

324

197

2,392

80

2

1,851

151

120

2

58

2

70

5,249

E

190.2

Trace.

47.9

5, 305. 8

Present.

1, 897. 1

31.6

Trace.

100.6

60.2

39.6

7, 673. 1

F

11.98

2.68

273. 75

6.79

9.51

3.65

145. 10

15.63

4.50

11.31

2.10

12.00

489. 00

G

1.5

60.2

6, 339. 1

Trace.

Trace.

51.9

12.0

116.8

1, 152. 3

6.7

6.5

82.5

7, 829. 5

H

1.09

6.48

405. 18

.54

5.24

1.76

TVopp

66.27

Trace.

18.85

.05

46.57

.30

69.36

621. 69

II. Percentage of total solids, all carbonates normal.

01......... I..........

F. .........

S04 .. ......

s.. ........ 00-3. ......

PO

As04 ......

B

r\ 4°7- - 

Na.........

K. ........

Li..........

Ca..........

Sr. ........

Mg. .......

Mn.. ......

Fe" .......

Fej08 .......

A1808 .......

SiOa -. ......

A

6.63

6.21

.06

44.76

41.07

.30

.12

.85

100.00

B

4.01

4.26

47.45

40.09

.38

Trace.

.27

.15

TVfi i**f*

.14

.20

3.05

100. 00

C

8.85

.19

5.77

41. 91

.01

.16

38.08

1.20

.12

.87

.05

.41

.06

.02

2.30

100. 00

D

6.17

3.75

45.57

1.52

.04

35.27

2.88

2.29

.04

1.11

.04

1.32

100. 00

E

3.84

Trace.

.98

52.09

Present.

38.39

.64

Trace.

2.04

1.22

Trace.

.80

100.00

F

2.42

.54

55.92

1.92

.73

29.28

3.15

.91

2.28

.43

2.42

100. 00

G

0.03

i.31

67.56

Trace.

Trace.

1.13

.26

2.54

25.03

.21

.14

1.79

100.00

H

0.28

1.68

38.72

.14

Trace.

1.36 -.46

17.18

Trace

4.89

.01

17.24

.07

17.97

100. 00

The water of Ojo Caliente is noticeable on account of its content of 

fluorine. This element is rarely determined in water analyses, but 

is almost invariably present. According to A. Gautier and P. 

Clausmann,1 its quantity in spring waters ranges from 0.30 to 6.32

' Compt. Rend., vol. 15S, p. 1631,1914.
188 DATA OF GEOCHEMISTRY.

milligrams per liter, being highest in waters issuing from areas of 

eruptive rocks. The highest values of all were found in the waters

of Vichy. 1

WATERS OF MIXED TYPE.

The following analyses, which are all reduced to the normal standard, represent waters of mixed type, chlorides with carbonates; sulphates with carbonates; or chlorides, carbonates, and sulphates all 

together. Waters of this character are very common, and show 

almost every stage of intermediate gradation.

Analyses of waters of mixed type.

A. The Virginia Hot Springs, Virginia. Average of six springs, analyzed by F. W. Clarke, Bull. U. S. 

Geol. Survey No. 9,1884, p. 33.

B. The Life well, Fairhaven Springs, Missouri. Analysis by P. Schweitzer, Geol. Survey Missouri, vol.3, 

1892, p. 174.

C. Deep well, Macomb, Illinois. Analyzed by G. Steiger in the laboratory of the United States Geological 

Survey.

D. Cleopatra Spring, Yellowstone National Park. Analysis by.F. A. Gooch and J. E. Whitfield, Bull. 

U.S. Geol. Survey No. 47,1888, p. 3G. Free C02,354 parts per million. 

E. Orange Spring, Yellowstone National Park. Analysis by Gooch and Whitfield, op. cit., p. 38. Free 

CO 2,92 parts per million.

F. Konigsquelle, Bad Elster, Saxony. Analysis by R. Flechsig, cited by A. Goldberg, 15, Ber. Naturw. 

Gesell. Chemnitz, 1904, pp. 74, 108. This memoir is a monograph on the mineral waters of Saxony and 

contains many analyses. Bicarbonates reduced to normal salts. Free CO2 is also present.

G. The Sprudel, Carlsbad, Bohemia. Analysis by F. Ragsky, cited by Roth, Allgemeine und chemische 

Geologic, vol. 1, p. 5C9. Contains 0.7604 gram free and half-combined CO2per kilogram. Also traces of Br, 

I, Li, B, Rb, and Cs.

H. Chalybeate water, Mittagong, New South Wales. Analysis by J. C. H. Mingaye, Proc. Roy. Soc. 

New South Wales, vol. 26,1892, p. 73. A very unusual water. In the same memoir, Mingaye gives many 

other analyses of Australian spring, artesian, and well waters.

ci. .................

Br.. ...............

F.. .................

so4 .. ...............

on

PO

At;O

B

r\ 4U7 . ............... "NTs

K. ...... ........... 

Li.................

NH4 ... ............

Ca.. ...............

Sr. .................

Mg.. ...............

Mn.. ...............

Fe. .................

Fe.,0a..............

AioU Al O 3 . .............

8i09 . ..............

Salinity, parts per

A

0.64

21.73

40.02

1.81

2.04

23.35

5.82

.58

4.01

100. 00 

563

B

0.06

51.54

16.84

5.33

16.86

6.39

.79

2.19.

100. 00 

1,670

C

18.02

33.22

13.14

26.88

.79

5.26

2.23

.07

04

qc

100. 00 

3,008

D

10.09

Trace.

30.34

21.65

.26

1.46

7.50

2.95 

13

03

17.76

4 91

.54

2.98

100.00 

1 739

E

10.07

Trace.

32.80

20.76

Undet.

7.65

3.78 

.10

17.50

4 OQ

13

3.12

100. 00 

1,612

F

20.36

31.47

10.96

32.51

.45 

oq

1.40

.44

.19

.59

1.40

100.00

4 QQ1

G

11.52

.03

31.19

19.15

.01

32.49

1.35

2.23

.01

.65

.01

.02

Trace.

1 34

100.00 

5,431

H

97 3A

30.58

*7 1%

8.96

4.25

5.89

15.85

100.00

OOK

i According to De Gouvenain (Compt. Rend., vol. 76. 1873, p. 1063), Vichy water contains 7.6 parts of 

fluorine per million. In the water of Bourbon-1'Archambault 2.68 parts of fluorine were found. For other 

examples of water containing fluorine see J. C. Gil, Mem. Acad. Barcelona, vol. 1.1896. p. 420; A. F. de 

Silva and A. d'Aguiar, Bull. Soc. chim., 3d ser., vol. 21,1899, p. 887; C. Lepierre. Compt. Rend., vol. 128, 

1899, p. 1289; J. Casares, Zeitschr. anal. Chemie, vol. 34, 1895, p. 546; vol. 44, 1905, p. 729; and P. Carles, 

Compt. Rend., vol. 144,1907, p. 37. Carles rarely failed to detect fluorine in mineral waters, commonly 

from 0.002 toO.004 gram per liter. In one Vichy water he found 0.018 gram, his maximum. This is 18 parts 

per million.
MINEBAL WELLS AND SPBINGS. . 189 

SILICEOUS WATEKS.

Waters characterized by a large relative proportion of silica are 

common, and a number of examples were noted among river waters, 

Uruguay River forming an extreme case. Springs issuing from 

feldspathic rocks are likely to contain silica as a chief inorganic constituent, but the absolute amount of it is generally small. In volcanic 

waters, on the other hand, and especially in geyser waters, the silica 

may reach half a gram to the liter, and sometimes even more.1 It is 

usually reported as Si03 ; although in some cases, when the ordinary 

acid radicles are insufficient to satisfy the bases, it becomes necessary 

to assume the existence of silicates, even if their precise nature is 

unknown. For such waters it is convenient to report this saline silica 

in the form of the metasilicic radicle Si03 , the dried residue being 

supposed to contain the sodium salt Na2SiO3 ; but this is hardly more 

than a convenient device for evading a recognized uncertainty. In 

solution, according to L. Kahlenberg and A. T, Lincoln,2 sodium 

metasilicate is hydrolyzed into colloidal silica and sodium hydroxide; 

and this conclusion was also reached by F. Kohlrausch 3 about five 

years earlier, although he stated it in a more tentative form. In 

natural waters, then, silica is actually present in the colloidal state 

and not in acid ions. On evaporation to dryness the silicate may 

form, but only when there is a deficiency of other acid groups. Such 

a deficiency is indicated by a pronounced alkalinity in any highly 

siliceous water.

For convenience the silicic waters are divided below into two 

groups -first, two waters are given which are probably not of volcanic 

origin; second, a number of geyser waters appear in a table by themselves. The first two waters are rather dilute.

1 For example, the Opal Spring, in the Yellowstone National Park, carries 0.7620 gram of silica per kilogram of water. The analyses of the Yellowstone Park waters, originally published in U. S. Geol. Survey 

Bull. No. 47, are also reprinted in Water-Supply Paper No. 364.

2 Jour. Phys. Chem., vol. 2,1898, p. 77.

s Zeitschr. physikal. Chemie, vol. 12,1893, p.' 773.
190 DATA OF GEOCHEMISTRY.

Analyses of silicic waters of nonvolcanic origin.

A. Big Iron Spring, Hot Springs of Arkansas. Analysis by J. K. Hay wood, Kept, to U. S. Dept. 

Interior, 1902. This is a typical water, selected from among the 46 springs which were analyzeu. All the 

hot springs in this group are very much alike. Hay wood reports Ms carbonates wholly as bicarbonates, 

and his figures are here restated in normal form that is, HCO& has been recalculated into the proper quantity of COa corresponding to the normal salts.

B. Cascade Spring, Olette, eastern Pyrenees. One of six analyses by E. Willm, Compt. Bend., vol. 

104,1S87, p. 1178. Temperature, 79.4° C. In this water, which might also be classed as a sulphur water, 

the radicle S2 0s represents the presence of tMosulphates, produced by the partial oxidation of sulphides. 

TMosulphates have also been reported in other waters, and several examples from Indiana are cited in 

Twenty-sixth Ann. Rept., Indiana Dept. Geology, 1901, pp. 76, 81, 86.

,

ci. ....... ...................................................

Br, I...........................................................

so4 .. .................. ........................................

s o

s.............................................................

CO.............................. .............................

KOi................... ........................................

Pf)

B0a ...... ...................................................

Na

K............................................................

Li. ..........................................................

NH4 .........................................................

Ca. ..........................................................

Ba, Sr....... :.................-...............................

Mg. ..........................................................

Mn. ..........................................................

Fc,Al.... ....................................................

Si02 . ........................................................

Salinity, parts per million. ....................................

A

1.27

3,93

41.47

.23

.03

.64

2.38

.80

Trace.

03

23.54

2.56

.17

.10

22. 85

100. 00 

ol99

B .

4.38

7.28

4.81

3.38

12.14

26.09

2.00

1.01

Trace.

38.91

100. 00 

244

a 2S4.8 in the original, where bicarbonates are included. In that statement HC03 forms 59.02 per cent 

of the saline matter. Tin's water might be equally well classed with th& carbonate waters.

For geyser waters and waters of similar character the data are 

abundant and only a few examples need be utilized here.

Analyses of siliceous geyser waters.

C. Coral Spring, Norris Basin, Yellowstonc National Park.

D. Echinus Spring, Norris Basin.

E. Bench Spring, Upper Geyser Basin, Yellowstone National Park.

F. Old Faithful Geyser, Upper Geyser Basin.

G. Excelsior Geyser, Midway Basin, Yellowstoue National Park. Analyses C to G by F. A. Gooch 

and J. E. Whitfleld, Bull. U. S. Gcol. Survey No. 47,1888. A number of other geyser waters were analyzed and are reported in this memoir. The figures given here vary somewhat from the original statements, having been recalculated on a different basis. The discrepancies, however, are very slight.

H. Great Geyser, Iceland. Analysis by Sandberger, Ann. Chemi Pharm., vol. 62,1847, p. 49.

I. To Tarata, Rotorua, New Zealand. The water which formed the white terrace of Rotomahana. A 

large excess of silica over bases, represented as SiOa.

J. Otukapuarangi, Rotorua geysers. The water of the pink terrace. Excess of silica very small. Analyses I and J by W. Skey, Trans. New Zealand Inst., vol. 10, 1877, p. 423. Thirteen other analyses are 

given in the memoir. J. S. Maclaurin, in Thirty-ninth Ann. Rept. Colonial Laboratory, Mines Dcpt., 

New Zealand, gives 23 analyses of mineral springs in New Zealand. Several of them are very high in 

silica. Sec also the Forty-second Report. JFor early analyses of Yellowstone waters see H. Leffman, 

Am. Jour. Sci., 3d ser., vol. 25,1883, pp. 104, 351. Analyses of several Icelandic geyser waters arc given by 

A. Dainour in Annales chim. phys., 3d ser., vol. 19, 1847, p. 470. .
MINERAL ..WELLS AND SPRINGS.

Analyses of siliceous geyser waters Continued.

ci........... .......

Br...................

so..................

s...................

eo3 . ...............

PO

/b HA

B A i}4U? - ...............

Na..................

K. .................

Li. ................

NE4 .. ...............

Ca............ .......

Mg.. ...............

Ma.. ...............

Fe. .................

Fe203....... ............

ALOa ........ ........

Al2.. 3 ........:......

SiOa .. ................

SiOa.. ................

Salinity, parts per

c

36.61

L 84

.15

OR

9 94.

21.44

4.45

.22

no

qq

.08

Trace.

.76

31. 72

100.00 

1,830

D

14. 93

Trace.

28.65

i 9Q

9 38

15.65

4.89

Trace.

TO

1. 42

"Wnn<s

.33

31. 33

100.001

808;

E

Trace.

29. 22

12.15

2.05

Trace

Trarp

Trace.

} 5. 80

' 50. 78

100.00

470

F

31. 64

.25

1.30

8.78

 TVFoTVP

94

T TQ1

26.42

1. 93

.40

Trace.

.11

.04

'Trace

Trace.

.12

27.58

100:00;

1,388

G

20: 91

' Trace.

1 1.31

25.01

T^rn PP

29

1 34-

31.34

2.43

.15

Trace.

.17

.17

Trace. ' 13

.17

16.58

100.. 00 

1,336

II

13.52

9.01

.32

10.16

19. 71

: 1.88

.28

08

45.04

100. oa

1,131

I

26. 82

3.60

Trace.

33, 94

1. Ql

Trace.

.38

.09

.20

.01

33.. 95

100. 00 

2, 064

J

37.52

4.96

24.22

.36

2.59

.19

Trace.

.35

29.81

100. 00 

2,. 735

NITRATE, PHOSPHATE, AND BORATE WATERS.

Although waters containing small quantities of nitrates, borates, 

or phosphates are, not uncommon, waters in. which these compounds 

are. conspicuous are rare. Melville's analysis of Steamboat Springs 

has already been cited, and the salts, from that water contain nearly 

9 per cent of the radicle B4O7, corresponding to about 11.5 per cent 

of anhydrous borax. 1 Nitrates are usually regarded as evidence of 

pollution in waters, but they do not necessarily indicate pollution. 

In arid regions, where nitrification goes on rapidly, nitrates may 

occur in considerable amounts; some of the underground waters of 

Arizona contain as high as 160 parts per million of nitrogen in this 

form.2 The following analyses probably represent extreme examples 

of phosphates, borates, and nitrates in natural waters : 3

1 Boric acid in natural waters has been discussed by L. Dieulafait in Compt. Rend., vol. 93,1881, p. 224; 

vol. 94, 1882, p. 1352; and vol. 100, 1885, pp. 1017, 1240. According to L. Kahlcnberg and 0. Schreiner 

(Zeitschr. physikal. Chemic, vol. 20, 1890, p. 5-17), the group B^O? is not the true ion of the borates. It 

is a convenient expression, however, for the negative radicle of borax.

« Sec W. W. Skinner, Bull. Arizona Expcr. Sta. No. 40,1903.

' The mineral water of Cherrydalc, Virginia, is also reported to be rich in nitrates. See analysis by J. K. 

Haywood and B. H. Smith, of a commercial bottled sample, in Bull. Bur. Chemistry No. 91, U. S. Dcpt. 

Agr., 1905, p. 54. Several springs in Massachusetts, reported by W. W. Skinner (Bull. Bur. Chemistry 

No. 139, 1911), are also remarkably high in nitrates.
192 DATA OF GEOCHEMISTRY.

Analyses of nitrate, phosphate, and borate waters.

A. Hot spring from sulphur bank oa the margin of Clear Lake, California. Analysis by G. E. Moore," 

Geol. Survey California, Geology, 1865, p. 99. In the original the carbonates are given as bicarbonates, and 

ammonium bicarbonate is reported to the extent of 107.76 grains per gallon. So great a proportion of 

ammonium in a water is extraordinary, although one acid water, cited later (p. 194), surpasses it. In the 

tabulation the bicarbonates are reduced to normal salts.

B. Hot water from the Hermann shaft, Sulphur Bank, California.

C. Hot water from the Parrott shaft, Sulphur Bank. Analyses B and C by W. H. Melville, cited by 

G. F. Becker, Mon. U. S. Geol. Survey, vol. 13,1888, p. 259. Some organic matter, a little H8 S, and a considerable amount of COa are reported in these waters.

D. Phosphatic water from Viry, Seine-et-Oise, France. Analysis by Bourgoin and Chastaing; abstract 

in Jour. Chem. Soc., vol. 54,1888, p. 354. The water issues from a gallery cut in clay. Bicarbonates reduced 

to normal salts. - "

E. Spring "Valette," at Cransac, Aveyron, France. One of nine analyses by A. Carnot, Compt. Rend., 

vol. Ill, 1890, p. 192. These springs issue below beds of coal and carbonaceous schists, in which fires have 

occurred. The nitrates were derived from the oxidation of the nitrogen compounds contained in the coal.

F. The holy well Zem-Zem, at Mecca. Analysis by P. Van Romburgh, Rec. trav. chim., vol. 5, 1886, 

p. 265. For a corroborative analysis see M. Greshoff, idem, vol. 16,1897, p. 354. The nitrates of this water 

are commonly ascribed to pollution by human agency; but it is not certain that so large a quantity, absolute 

or relative, could be derived from that source.

Cl...... ...................... I.............................

S04 ........................

CO....... ....................

N03 . ........................ BA-- ......................

PO

Na. .........................

K............................

Li...........................

NH

Ca.................. .........

Mg.. .........................

Mn.. .........................

Fe".. ........................

Fe"'. .......................

A1203 ------------------------

SiOa ................ .........

Salinity, parts per million.

A

16.49

.03

Trace.

 21.96

25.61

24.99

Trace.

7.88

Trace.

Trace.

.40

2.64

100. 00 

05,343

B

13.57

.32

22.38

27.98

33.97

.48

.05

.41

.11

?q

100.00 

5,096

C

14.39

10.06

4 73

40.09

28.49

84

f>9

AA

03

.01

.90

100. 00 

4,632

D

5.11

7.74

19.46

6.33

22. 41

3.32

Trace.

Trace.

30.38

1.21

4.04

100. 00 

490

E

5.45

27.87

2.58

36.09

3.53

- .68

TVapp

15.93

5.17

.06

.06

2.58

100. 00 

1, 163

F

16.44

14.04

12.78

24.62

12.66

6.67

8.70

9 7rt

1 3Q

100. 00 

3,455

a Reckoned with normal carbonates. With bicarbonates the salinity becomes 6,556 parts per million.
MINERAL WELLS AND SPRINGS. 193

ACID WATERS.

The last group of waters that we have to consider are those which 

contain free acids, sulphuric or hydrochloric. They may be classified in two divisions first, acid waters derived from sedimentary 

rocks, their acidity being probably due to the oxidation of pyrites or 

other sulphides; second, waters of volcanic origin. Under the first 

heading the four analyses given below may be cited. In these analyses it seems best to state the free acids as such and not in the form 

of ions, and to give, instead of the normal "salinity," the total 

inorganic impurity in parts per million.

Analyses of acid waters from sedimentary rocks .

A. The Tuscarora sour spring, 9 miles south of Brantford, Canada. Analysis by T. Sterry Hunt, Geol. 

Survey Canada, 1863, p. 545. .

B. Oak Orchard Spring, Alabama, Genesee County, New York. Analysis by W. J. Craw, Am. Jour. 

Sci., 2d ser., vol. 9, 1850, p. 449. The free acid is stated in the original as SOa; it is here recalculated into

C. Spring 9 miles northwest of Jonesville, Lee County, Virginia. Analysis by L. E . Smoot, Am. Chem. . 

Jour , vol. 19, 1897, p. 234. Acidity low.

D. Rockbridgo Alum Spring, Virginia. Analysis by M. B. TTardin, Am. Chemist, vol. 4, 1873-74, p. 247. 

This water and that analyzed by Smoot might be equally well put in the ordinary sulphate group with 

other "alum" springs.

HoS04 , free- ...................................

HNOa> free.. .................................. ci....... .......................................

PO

Na... .................................:....... K................ ....:.........................

Li.............................................

Ca....... ...................................... Mg............. .......:.............'...'......

Fe"..........................................

Fe"'_. ........................................

Mn............................ :..............

Ni............. ................................

Co.............................................

Zn.................. ...........................

Cu............... ..............................

Al. ...........................................

SiO............ ................................

Total inorganic impurity, parts per million ......

A

69.62

i

22. 11

Trace.

.26

.44

3.70

.50

2.17

1 90

100. 00 

6,161

B;

47. 87

.43

36.28

.87'

.71

6.39

2.06

3.06

1.00

1.33

100. 00 

a5,136

C

5.82

.18

75.14

1 1Q

'2.^4

no ce

2.88

100. 00 

3,715

D '

Q VI

Trarp

qo

/»O O"l

Trarp

99

.11

.01

.38

1.11

1 1Q

fin

.07

.05

.08

Trace.

11. 08

7.11

100. 00

4fi4

a 4,685 when the free acid is reckoned as 80s. 

113750° ft) Bull. 695 13
194 DATA OF GEOCHEMISTRY.

Among volcanic waters acidity is much more common, and many 

examples of it are known. The following analyses are among the 

most typical, and are stated in the normal percentage form:

Analyses of acid waters of volcanic origin.

A. Devils Inkpot, Yellowstone National Park. Analysis by F. A. Goocli and J. E. Whitfield, Bull. 

U. S. Geol. Survey No. 47,1888, p. 80. Acidity slight. This water is unique on account of its high propartion of ammonium salts. It contains NH< equivalent to 2.8 grams of ammonium sulphate per liter, or 

about 83 per cent of the total impurity. Contains also 65 parts of free CCh and 5 parts of H2S per million. 

As an ammoniacal water this may be compared with the borate water from Clear Lake, California, previously cited.

B. Acid Spring, California Geysers, Sonoma County, California. Temperature 60° C. Analysis by 

Thomas Price, Trans. Technical Soc. Pacific Coast, vol. 5, 1888, p. 48. Eleven analyses of other waters 

from this group of springs are also given.

C. Water from Cove Creek sulphur beds, Utah. Recalculated from the analysis by W. M. Barr, as published by W. T. Lee in Bull. U. S. Geol. Survey No. 315,1907, p. 489. The water issues from rhyolitic tuffs, 

but may not be of strictly volcanic origin.

D. Rio Vinagre, Colombia. Analysis by J. B. Boussingault, Annales chim. phys., 5th ser., vol. 2,1874, 

p. 80. Free SO3 recalculated into H2SO.». Boussingault also gives analyses of several saline waters from 

the same region. On p. 81 he estimates that Bio Vinagre at Purace carries each day 46,873 kilograms of 

HsSO-j and 42,150 kilograms of HC1. These figures correspond to 17,000 and 15,000 metric tons per annum.

E. Hot Spring, Paramo de Rmz, Colombia. Analyses by H. Lewy, cited by Boussingault, op. cit.,p. 91. 

Free SO3 recalculated into HsSO.i.

F. Solfatara at Pozzuoli, Italy. Analysis by S. De Luca, Compt. Rend., vol. 70,1870, p. 408.

G. Brook Sungi Pait, from crater of Idj6n volcano, Java. Analysis by F. A. Fliickiger, Jahresb. 

Chemie, 1862, p. 820. Acid waters are not uncommon in Java.

HC1, free............

H2S04) free...........

H3B03 .. ............. ci... ................

<3O

s. ...................

NO"NTn

K.......... ..........

Li....................

NTT

Ca........ ............

Mg..., ................

Mn..................

Fe"... ..............

Fe^....... ..........

Al....... ............

As....................

SiOo........ ..........

Total impurity, parts ;

A

0.18

1.29

2.73

67.66

.73

.24

.01

22. 85

1.18

.36

TYflpp

.10

2. 67

100. 00 

3, 365

B

49.71

33.92

.58

.10

.41

5. 72

1.92^

1.02

6. 62

100.00 

5, 467

C

31.38

.81

46.95

.04

.02

1.47

1.62

2.48

5.74

8.22

None.

1.27

100. 00 

9, 760

D

35.92

1.89

4.75

43. 97

3.08

2.45

7.14

.80

100. 00 

2,969

E

5.50

44.17

4.96

31.71

3.22

1.21

2.31

1.53

3.18

2.21

100. 00 

8 9Qfi

F

16.62

.34

55.08

Trace.

.57

.58

2.91

.55

Trace.

3.47

7.16

Trace.

12. 72

100. 00 

2 477

G '

4Q Oft

14 Q^

26.96.

1 00

.39

2.05

- 04

4.66

4 44

.33

100; oo

18, 060
MINERAL WELLS AND SPRINGS.

Analyses of .acid waters of volcanic origin Continued. 

E. Hot .Lake, White Island, Bay of Plenty, New Zealand. Analysis toy C. i>u Ponteil, Ann. Chem. 

Phann., vol. 96,1855, p: 103. Practically a 10 per cent solution of hydrochloric acid.

1. Probably the same water as that of H. Analysis by W. Skey, Trans. New Zealand Inst., vol. 10, 

1S.77, p. 423. In a later analysis by J. S. Maclaurin (Proc.'Cliem. Soc., vol. 27,1911, p. 10), the presence of 

pentathionic acid is reported.

J. Cameron's Bath, Rotorua 'geyser district, New Zealand. Analysis by Skey, loc. cit. Contains 6 

parts per million of H»S.

1C. Yellow lake or hot pool, crater of Taal volcano, Luzon, Philippine Islands.

L. Green lake or pool, carter of'Taal volcano. Analyses iC and L by J. Centcno, Estudio geol<5gico del 

volc&n de Taal, Madridj 1SS5. Obscurely stated. Recalculated ^on the assumption "that "fosfato s<5dico" 

means NasPO^ and that sulphuric acid means HzSO* and not SOg. The free acid,.however, should probably be all hydrochloric, with no sulphuric at all. In this matter I have simply followed -the author. Compare citation by G. F. Becker, Twenty-first Ann. Rept. U. S. Geol. Survey, pt. 3,1901, p. 49. For recent 

analyses of these Taal waters, see R. F. Bacon, Philippine Jour. Sci., vol. 1,1906, p. 433; vol. 2,1907, p. 115. 

Unfortunately, these analyses, which corroborate Centeno's, are stated in such fo/m that I can not reduce 

them to the uniform standards.

HCl,free.............................

HoSO., free. ............................

H,BO,.. ...... ........................

01............ ........................

so....................................

PO

B407 -------------. ----------------

Na. ................................. K.. :.................................

Mg.. .................................

Mn..... ..............................

Fe". .................................

Fe'"............ ......................

AL. ..................................

As...................................

SiO

H

65.42

11.69

10.34

1.91

Trace.

.75

50

2.30

.34

5.98 ,

,35

.03

100. ;00 

158, 051 '

I

69. 99

9.96

11.34

1.56'

.. 90 :

.50

no

2/86

2.62

.18

100. '00 

194,830

J

5.60

59. 11

20.21

Trace.

8. .35

.32

.47

.22

.33

Trace.

5.39

100.00

1,862

K.

5.87

47.26

9. -50

1.26

24. 14

1.38

.56

98

.78

5.35

.55

2.37

100.00 

26, 989

L

13. 04

2.48

44. 52

6.40

.73

20.75

3.03

.22

1 09

1.03

5.55

1 9^

100. 00 

60, 023

Still another acid water, from the crater of Popocatepetl, was 

partially analyzed by J. Lef ort.1 It contained 11..Q0.9 grams of hydrochloric acid and 3.643 of sulphuric acid in 1,'OOG parts, together with 

2.080 grams of alumina, 0.699 of soda, and 0.081 of ferric oxide. 

Lime, magnesia, silica, and .arsenic were present in traces. These 

data are too incomplete to admit of systematic discussion. The 

total dissolved matter amounted to 17,512 parts per million.

J. B. Boussingault,2 in his memoir on the acid waters of the Colombian Andes, discusses at some length the question of their origin. 

He shows that hydrochloric acid may be generated by the action of 

steam upon a mixture of chlorides ^and .silica, and ,also that hot gaseous hydrochloric acid will liberate sulphuric acid from .sulphates. 

Both of these reactions may take place .in volcanoes. Sulphuric acid 

may also be formed by volcanic heat, sulphur, either free or derived,

Compt. Rend., vol. 56,1863, p. 909. 2 Annales chim. phys., 5th scr., vol. 2, 1S74, p. 70.
196 DATA OF GEOCHEMISTRY.

from sulphides, first burning.to S02, which afterward, in presence 

of moisture, oxidizes to H2S04. It is also to be borne hi mind that 

aqueous sulphuric acid will decompose chlorides, with liberation of 

HC1, and this reaction also probably occurs. The acidity of a volcanic water, then, may be due to a variety of causes, which operate 

under varying conditions of material and temperature. We may not 

be able to say with certainty that a given water of this class originated in a given way, but we can see that the reactions which produce it are neither complex nor obscure.

SUMMARY OF WATERS.

From the evidence before us the classification of natural waters 

according to their negative or acid ions seems to be fully justified. 

This question has been partially discussed hi previous chapters; but 

the greateV variety of composition shown by mineral springs enables 

us now to cover the ground much more completely. The main 

divisions and subdivisions are as follows:

I. Chloride waters. Principal negative ion Cl. 

A. Principal positive ion sodium. 

B. Principal positive ion calcium. 

C. Waters rich in magnesium.

II. Sulphate waters. Principal negative ion S04 . 

A. Principal positive ion sodium. 

B. Principal positive ion calcium.

C. Principal positive ion magnesium. .. . . D. Waters rich in iron or aluminum. " 

E. Waters containing heavy metals, such as zinc.

III. Sulphato-chloride waters, with S04 and Cl both abundant.

IV. Carbonate waters. Principal negative ion C03 or HC03 . 

A. Principal positive ion sodium. 

B. Principal positive ion calcium. 

C. Chalybeate waters.

V. Sulphato-carbonate waters. S04 and C03 both abundant.

VI. Chloro-carbonate waters. Cl and C03 both abundant.

VII. Triple waters, containing chlorides, sulphates, and carbonates in equally 

notable amounts.

VIII. Siliceous waters. Rich in Si02 .

I.. Borate waters. Principal negative radicle B407 .

X. Nitrate waters. Principal negative ion N03 .

XI. Phosphate waters. Principal negative ion P04 . 

XII. Acid waters. Contain free acids. 

A. Acid chiefly sulphuric. 

B. Acid chiefly hydrochloric.

This classification is sufficient for all practical purposes, although 

it might be subdivided still further in order to cover certain exceptional cases, as, for example, the feebly acid ammonium sulphate 

water of the Devil's Inkpot. Many waters are obviously intermediate in character, like the brines containing both calcium and
./

MINERAL WELLS AND SPRINGS. 197

sodium, or the sulphates of two or more bases in something like 

equally important quantities. In a classification based on therapeutic considerations sulphur waters would form a distinct group; 

but sulphides occur in subordinate amounts, and from a chemical 

point of view are merely incidental impurities. It has already been 

observed that mixtures can not be classified rigorously, a conclusion 

which it is well to reiterate now. The classification of natural 

waters is only approximate, and a matter of convenience rather than 

of fixed principles.

CHANGES IN WATERS.

When the water of a spring emerges into the open air it begins to 

undergo changes. It may flow into other waters and so lose its 

individuality; it may simply evaporate, leaving a saline residue; it 

may react upon adjacent material and so produce new substances; 

or, by cooling, it may deposit some one or more of its constituents. 

The first of these contingencies admits of no systematic discussion; 

the third will be considered in the next chapter; the others can 

receive attention now.

Alteration by loss of gaseous contents is observed in two important groups the sulphur waters and those containing an excess of 

carbonic acid. Hydrogen sulphide partly escapes into the atmosphere without immediate change, and part of it is oxidized, with 

deposition of sulphur and the formation of thiosulphates and finally 

sulphates, which remain in solution. Deposits of finely divided 

sulphur are common around those springs which emit hydrogen 

sulphide, but they frequently contain other substances, such as 

silica, calcium carbonate, and ocherous matter. Since, however, the 

sulphur is a product of partial oxidation, this change comes more 

appropriately under the heading of reaction with adjacent material, 

the latter, in this case, being oxygen derived from the air. The 

hydrogen sulphide itself may be generated by the action of acid 

waters upon other sulphides, but it is more commonly produced by 

the reduction of sulphates through the agency of organic matter, 

and the subsequent decomposition of the resultant alkaline compounds by carbonic acid. The last reaction, however, as A. Be'champ 1 

has shown, is reversible. Carbon dioxide decomposes solutions of 

calcium hydrosulphide; but, on the other, hand, hydrogen sulphide 

can partly decompose solutions of calcium carbonate. Bicarbonates 

and sulphides, therefore, can coexist in mineral waters in a state of 

unstable equilibrium.

 » Annales chim. phys., 4th ser., vol. 16, 1869, p. 202. See also a recent physicoclicmical discussion by 

F. Auerbach, Zeitschr. physikal. Chcmie, vol. 49, 1904, p. 217. ^.
198 DATA OF GEOCHEMISTRY.

CALCAREOUS SINTER.

With carbonated waters the changes due to escape of gas are more 

conspicuous, at least when calcium, magnesium, or iron happen to be 

the important basic ions. When the "bicarbonic" ion HC03 breaks 

up, losing carbon dioxide to the atmosphere, the normal calcium or 

magnesium carbonate is formed and, being insoluble, is precipitated. 

If we assume calcium bicarbonate as existent in solution, the reaction 

is as follows:

CaH2CA=CaC03 +H20 + C02 ;

but the change is modified by other substances which may be present, 

and so the product is rarely pure, nor is the precipitation absolutely 

complete. Calcareous sinter, tufa, or travertine is thus produced, 

and in many localities it is an important deposit. The carbonate 

waters of the Yellowstone Park, for example, form large bodies of 

this character, and many analyses of it have been made. It is also 

abundant in the Lahontan and Bonneville basins, as mentioned in 

the preceding chapter. The following analyses of typical American 

material are sufficient to show its usual composition:

Analyses of calcareous sinters.

A. Travertine, Terrace Mountain, Mammoth Hot Springs, YelloTOtone National Park. Analysis by 

F. A. Gooch, Bull. U. S. Gcol. Survey No. 228, 1904, p. 323. . B. Travertine, near Pulsating Geyser, Mammoth Hot Springs. Analysis by J. E. Whitueld, Bull. 

U. S. Geol. Survey No. 228,1904, p. 323. Other analyses of calcareous deposits are given in the same publication. See also W. H. Weed, Ninth Ann. Rept. U. S. Geol. Survey, 18S9, p. 619.

C. Lithoid tufa, Lahontan basin, Nevada. One of three analyses by O. D. Alien, cited by I. C. Russell, 

Mon. U. S. Geol. Survey, vol. 11, 1885, p. 203..

D. Calcareous tufa, main terrace, Redding Spring, Great Salt Lake Desert. Analysis by R. "W. Woodward, Rcpt. U. S. Gcol. Expl. 40th Par., vol. 1,1878, p. 502.

Si02 . ........................................

A1203 . .......................................

Fe203 . .......................................

CaO... ........................................

MgO.. .......................................

K2 0. .........................................

NasO.. ........................................

LioO. ........................................

NaGl.... ......................................

CL... ...... ..................................

S03 ........ .......... ........................

C08 .. .........................................

P20fi . ........................................

H2Q. ......... ................................

C, organic. ....................................

A

0. 09

I "

55.37

.35

.04

.10

.44

43. 11

.32

.17

100. 10

B

0.05

} "

 52.46

.90

.71

Q9

1.45

1.82

40.88

1.02

.30

100. 03

C

1. 70

1 25

f £O

50. 48

2.88

Trace

Trace.

41 8&

Qfl

2.07

99.53

p

C Af\

i qi

Trace.

46.38

Q KA

.22

.48

Trace.

38.20

Trace

1.71

100. 24
MINEKAL WELLS AND "SPBINGS. 199

Analyses of several European tufas, are given by Roth,1 and they 

exhibit many variations in composition. Ten calcareous deposits 

from the springs of Vichy were analyzed by J. Bouquet,2 who found 

strontium and arsenic in them. The arsenic ranged from a trace to 

1.16 per cent of As2O5 . In the Carlsbad "Sprudelstein" Blum and 

Leddin 3 also found arsenic to the extent of 0.27 per cent. In a tufa 

from the Doughty Springs, in Delta County, Colorado, W. P. Headden 4 found barium sulphate ranging from a small amount up to nearly 

95 per cent. . This tufa or sinter was distinctly radioactive, and 

probably contained traces of radium.

The commonest companion of calcium carbonate, in sinter is magnesium carbonate; which is rarely, if ever; absent. According to 

H. Leitmeier 5 the springs of Lohitsch in Styria deposit hydrous carbonate of magnesium. The presence of magnesium salts in a water 

favors the deposition of calcium carbonate in the form of aragonite, 

as shown by F. Cornu 6 and F. Vetter.7 Calcite, however, is much 

more common in sinters than aragonite. In rare instances fluorite 

is deposited.8 Silica and ferric hydroxide are also frequent contaminations of tufas. In short, the calcium carbonate precipitated 

from natural waters may carry down with it a great variety of impurities, which depend upon the character of the spring.

OCHEROUS DEPOSITS.

When ferrous ions are present in a carbonate water, loss of carbonic 

acid is followed or accompanied by oxidation, and the precipitated 

material is an ocherous ferric hydroxide. Around chalybeate springs 

these deposits of iron rust are always noticeable. With substances 

of this character calcium and magnesium carbonates are often thrown 

down, and also silica, so that the ochers from iron springs vary much 

in composition. Between an ocher and a calcareous sinter every 

intermediate mixture may occur. Sometimes when sulphates have 

been reduced by organic matter sulphides of iron are deposited, and 

a number of examples of this kind are cited by Roth.9 The following 

analyses will illustrate the usual character of these sediments:

1 Allgemeine und chemische Geologie, vol. 1, p. 539.

3 Annales chim. phys., 3d ser., vol. 42,1854, p. 332. JFor later analyses of Vichy deposits, see C. Girard 

and F. Bordas, Compt. Bend., vol. 132,1901, p. 1423.

s Ann. Chem. Pharm., vol. 73,1850, p. 217.

«Prpc. Colorado Sci. Soc., vol. 8,1905, pp. 1-30. Analyses of six of the springs are given in this memoir, 

and several analyses of sinters. On the coexistence of barium and sulphates in mineral waters see P. Carles, 

Jour. Chem. Soc., vol. 80 (abstracts), pt. 2,1901, p. 506. Alkaline bicarbonates, with an excess of COz, can 

hold barium in solution, notwithstanding the presence of sulphates. R. Delkeskamp, in Notizbl. Vcr. 

Erdkunde, 4th ser., Heft 21, p. 47, has discussed the occurrence of barium in natural waters and tabulated 

a large number of occurrences. See also J. White, Jahresb. Chemie, 1899, p. 635, on barium in artesian 

waters of Derbyshire.

6 Zeitschr. Kryst. Min., vol. 47,1909, p. 104.

8 Oesterr. Zeitschr. Berg- u. Hiattenw., vol. 55,1907, p. 596. 

"* Zeitschr. Kryst. Min., vol. 48,1910, p. 45.

8 See W. Lindgren, Econ. Geology, vol. 5,1910, p. 22.

0 Allgemeine und chemische Geologie, vol. 1, pp. 599, 600.
200 DATA OF GEOCHEMISTRY.

Analyses of ocherous deposits.

A. Deposit from Driburg, Germany. Analysis by F. J. H. Ludwig, Jahresb. Cheinie, 1847-48, p. 1012. 

 B. Deposit from Nauheim, Germany. Analysis by Ewald, Jahresb. Chemie, 1847-48, p. 1012.

C. Depositfrom Enclos des Celestins, Vichy. One of four analyses by J. Bouquet, Annales chim. phys., 

3d ser., vol. 42,1854, p. 336. The "quartz and mica," of course, do not belong with the sediment, but are 

an accidental addition to it.

D. Deposit from Chalybeate Spring, Death Gulch, Yellowstone National Park. Analysis by J. E. 

Whitfield in the laboratory of the United States Geological Survey. For an analysis of water from Death 

Gulch,see G. B. Frankforter, Jour. Am. Chem. Soc., vol. 28,1906, p. 714.

Feo03 .. ........................................

Mn2 03 . ........................................

A1203 ..........................................

CaO

CaC03 ...... ................................... Mgco3 ........... .............:................

NaCl, etc. .;..................................

S08 ...........................................

p n

As20,. ........................................

Soluble SiOa .. . ...............................

H20. . ........................................

Sand..........................................

C02 and loss ..................................

A

57. 303

6.683

.543

.063

23. 333

.542

5. 383

6.145

100. 000

B

49.86

.40

20.81

2.59

2.81

23.53

100. 00

 c

47.40

'Pvopn

10.85

6.03

Trace.

6.96

1.04

| 25. 72

2.06

100. 06

D

63.03

.08

8.35

1.37

| 26.94

99.77

The deposit represented by analysis D evidently contains an 

admixture of a basic sulphate of iron. A number of such salts are 

known among natural minerals, and are commonly formed by deposition from chalybeate solutions. Their consideration, however,, does 

not belong in this chapter. Ocherous deposits rich in manganese 

are also known. For example, M. Weibull 1 has described a spring 

near Lund, in Sweden, which contains 23 milligrams of MnO to the 

liter of water. From this, by the action of the organism Crenothrix 

manganifera, the manganese oxide is precipitated in such quantities 

as to clog water pipes.

SILICEOUS DEPOSITS.

Siliceous deposits are formed by all waters containing silica, but 

are commonly so small as to be inconspicuous. The silica then appears, as in the preceding tables of analyses, as an impurity in something else. From hot springs, however, which often contain silica 

in large quantities, great bodies of sinter are produced, and this has 

a composition approaching that of opal. Mineralogically, siliceous

1 Jour. Chem. Soc., vol. 92, pt. 2, 1907, p. 888, abstract.
MINERAL 'WELLS AND SPRINGS. 201

sinter is classed as a variety of opal, for it consists mainly of hydrated 

silica with variable impurities. According to W. H. Weed,1 who 

has studied the formation of sinters in the Yellowstone Park, the 

deposit may be due either to relief of pressure, to cooling, to chemical 

reactions between different waters, to simple evaporation, or to the 

action of algae. In the last case the silica forms a gelatinous layer 

upon the algous growths, and this, after the death of the algae, gradually hardens to sinter. The subjoined analyses (A to E) of Yellowstone Park sinters are selected from among fifteen which were made 

by J. E. Whitfield in the laboratory of the United States Geological

Survey.2

Analyses of sinters from Yellowstone Park, etc.

A. Incrustation, Excelsior Geyser Basin. 

B. Opal deposit, Norris Basin. 

C. Compact sinter, Old Faithful Geyser. 

D. Deposit from Artemisia Geyser. 

E. Geyserite incrustation, Giant group, Upper Basin.

F. Siliceous sinter, Steamboat Springs, Nevada. Analysis by R. W. Woodward, Kept. U. S. Geol. 

Expl. 40th Par., vol. 2,1877, p. 820.

SiOa .........................

A1203 .- .....................

Fe,08 ........................

Feb.3.........................

CaO. ........................

MgO.. .....................'..

K20.......... .......... ......

NaaO........................

Nad................. -......

H2 0«. ......................

c............................

S03 . ........................

S.. .........................

A

94.40

1 .79

None.

None.

5.02

100. 21

B

93.60

1.06

Trace.

.50

Trace.

4.71

Trace.

99.87

C

89.54

2.12

Trace.

1.71

Trace.

.30

1.12

Trace.

5.13

Trace.

99.92

D

83.10

6.02

Trace.

.80

.21

.87

2.18

6.73

.28

100. 19

E

72.25

10.96

.76

.31

.74

.10

1.66

3.55

,36

9.02

.20

.45

100. 36

F

09 fi7

} .80

.14

.05

.18

.75

5.45

100.04

o Loss on ignition.

At Steamboat Springs G. F. Becker 3 found the deposits to contain 

also sulphides of antimony, arsenic, lead, copper, and mercury, ferric 

hydroxide, gold, silver, and traces of zinc, manganese, cobalt, and 

nickel.

1 Am. Jour. Sci., 3d ser., vol. 37,1889, p. 351.

2 Bull. U. S. Geol. Survey No. 228,1904, pp. 298-299. A very exceptional sinter, from a warm spring in 

ftelangor, Malay States, contains, with 91.8 per cent of Si02, 0.5 per cent of Sn02 . See S. Meunier, Compt. 

Rend., vol. 110,1890, p. 1083. According to W. R. Jones (Geol. Mag., 1914, p. 537), the water of this spring 

contains no tin.

8 Mon. U. S. Geol. Survey, vol. 13,1888, pp. 343-346.
202 DATA' OF GEOCHEMISTRY.

The following analyses represent sinters from foreign localities: 1

Analyses of sinters from foreign localities.

G. Ceyserite, Iceland. Analysis by A. A. Damour, Bull. Soc. ge"ol. France, 2d ser., vol. 5,1847-48, p. 160.

H. Deposits from the Scribla Spring, Icelandic geysers. Analysis by C. Bickell, Ann. Chem. Pharm., 

vol. 70,1849, p. 293.

I. Sinter from the hot springs of Taupo, New Zealand. Analysis by J. W. Mallet, Philos. Mag., 4th ser., 

vol. 5,1853, p. 285.

J. Sinter from geysers of Rotorua, New Zealand. Analysis by J. E. Whitfield, discussed by W. H. 

Weed, Ninth Ann. Eept. U. S. Geol. Survey, 1889, p. 619. Two other analyses are given in this report.

K. Sinter from the Mount Morgan gold mine, Queensland. Analysis by E. A. Schneider, discussed by 

W. H. Weed in Am. Jour. Sci,, 3d ser., vol. 42, 1891, p. 166. This sinter is impregnated with auriferous 

hematite. In sinters from the gej'ser district of New Zealand, according to J. M. Maclaren (Geol. Mag., 

1906, p. 511), there are also appreciable quantities of gold and silver.

Si02 .... ...............................

AI n 

TRV O

MgO.... ................ .................

CaO........ ...........................

KaO.. ................................

NaoO

NaCL. ................................

H.O..................................

S03 ........ .-.........:--......---..

G -

87.67

| ,!

.40

Trace.

.82

10:40

100: oo

H

88.26

.69

3.26

Trace.

.29

Ml

.11

4.70

2.49

100. 00

I

94.20

1.58

1.17

Trace.

.85

3.06

" 99.86

J

92.47

2.54

.15

.79

3.99

99. 94

K

94.02

1 2.27

Trace.

.07

3

0f>

99.72

The sinters, however, represent only the simplest form of deposit 

from geysers and siliceous springs. A great variety of intermediate 

substances, mixtures of silica, of hydroxides, of carbonates, sulphates, 

or arsenates, and even of sulphur, have been observed, and a number 

of analyses made- in the laboratory of the United States Geological 

Survey by J. E. Whitfield are cited below as illustrations of this 

fact. All the samples analyzed were collected in the Yellowstone 

National Park.

Analyses of spring deposits from Yellows lone Park.

A. Deposit from spring No. 75, Norris Basin. Dried at 104°. 

B. Saline deposit, Shoshone Geysers; Dried at 104°. 

C. Sediment from Crater Hill. 

D. Black coating, Fairy Springs. Air dried. 

E. Deposit from Chrome Spring, Crater Hill.

F. Sedimentary deposit from Lamar River. . . .. 

G. Deposit from Constant Geyser. Described by Arnold Hague in Am. Jour. Sci., 3d ser., vol. 34,1887, 

p. 171. Contains scorodite. 

H. Red, ocherous deposit, Arsenic Geyser. Air dried.

i For additional analyses see Roth, Allgemeine und chemische Geologie, vol. 1, p. 593.
MINERAL WELLS AND SPRINGS. 

Analyses of spring deposits from Yellowstone Park Continued.

203

Si02 .................

AlaO,.. ...... ...... ..

Fe203 ................

MnO?... ....... ......

MnO Mgo:................

CaO... ..............

Na/)..... ...........

K n

Li20.... .............

H20.. ................

co2 ...... ............

so3 .................

s.... .................

AH O

C, organic............

A

54. 36

5. 90

25. 48

.33

.17

1. 86

1.30

1 91

9.60

.28

100. 49

B

50.03

2. 15

Trace

Trace. : 24.18

00

.24'

4.78

12.92

5.40

100. 02 :

vC

54. 12

18. 03

.86

Trace.

.32

.49

3.82

7.12

15. 41 i

100. 27

D

21. 36

3. 11

9.17

6.19 i

38.65

.82

7. 50

13. 02 :

.09

99. 91

E

68.73

3. 66

.29

2.14

6.15

18. 79

99. 76

F

29. 23

Trace.

1. 91

.07

.50

3. 03 ,

 4. 29

1.04

100. 07

G

49.83

4.74

18 00

10.62

17 °.7

100. 56

II

41. 20

9. 53

19.35

15.70

.24

14. 08

100. 10

Analyses G and H are especially interesting, for they represent 

the deposition of scorodite, FeAs04 2H,0. This occurs still more perfectly at Josephs Coat Springs, in the Yellowstone Park, where the 

mineral has been separated from an incrustation and identified. 1 

The manganese in D and the sulphur in E and F are also worthy of 

notice. When we consider that in addition to these precipitates 

many saline compounds are produced by the simple evaporation of 

waters, we see that the range of possibilities must be very great. 

When a water has become sufficiently concentrated to begin the 

deposition of solid matter, every change in concentration or temperature introduces a new set of conditions which determine the nature 

of the compounds to be formed. The complexity of the problems 

which thus originate will become more evident when we study the 

subject of saline residues. It is clear, from the nature of the products 

thus far considered, that in a complex water several reactions may 

take place simultaneously, a number of substances being throwa 

down at the same time. If a water carrying much iron and much 

calcium, loses hydrogen sulphide and carbonic acid, then ferric hydroxide, calcium carbonate, and sulphur will be deposited together, 

each change being independent of the others. In such cases the 

complexity of reaction is apparent only and not real. The reactions 

are all simple and easily understood: When salts are formed by 

evaporation of a water, the interpretation of the phenomena is more 

difficult.

1 A. Hague, Am. Jour. Sci., 3d ser., vol. 34,1887, p. 171. See also J. E. Whitfield, Bull. U. S. Oeol. Survey No. 55, 1889, p. 65.
\

204 DATA OF GEOCHEMISTRY.

REACTIONS WITH ADJACENT MATERIAL.

The reactions of natural waters in contact with adjacent materials 

are of many different kinds. We have already seen how oxygen 

from the atmosphere may convert ferrous into ferric compounds and 

sulphides into sulphates, but reducing agents also must be taken into 

account. The sulphates of a water, by accession of organic matter, 

can be partly or entirely reduced to sulphides, and carbonic acid, 

acting upon the latter, may expel sulphureted hydrogen and produce 

carbonates. By reactions of that kind a water can undergo a complete change of type and pass from one class into another.

Acid waters, especially when hot, act vigorously on the substances 

with which they come in contact, producing soluble chlorides or sulphates according to their character. Hydrochloric acid forms the 

one set of salts, sulphuric acid the other. The extent of the reactions 

will, of course, depend upon the kind of material attacked, for some 

minerals and rocks are much more soluble than others. The carbonate rocks are naturally the most attackable, but no rock is entirely 

exempt from changes of this order. When we remember that even 

pure and cold water exerts a solvent action upon many silicates, we 

can see how violently corrosive a hot, acid, volcanic water must be. 

Wherever waters of this class occur the surrounding rocks are more 

or less decomposed, calcium, magnesium, alkalies, and iron being 

dissolved out, while silica and hydrous aluminum silicates remain 

behind. As the water cools and as the acid becomes neutralized its 

activity decreases, and its peculiar characteristics gradually disappear. 

An ordinary saline or astringent water is the product of these changes, 

which take place most rapidly when the active solutions are concentrated and hot, and more slowly in proportion as they are diluted or 

cooled.

Waters containing free sulphuric or hydrochloric acid are, however, 

relatively rare, and their geological importance is small compared 

with that of carbonated solutions. Meteoric waters carrying free 

carbonic acid are probably the most powerful of agents in the solution 

of rocks, although their chemical activity is neither violent nor rapid. 

Being continually replenished from the storehouse of the atmosphere, 

their work goes on unceasingly over a large portion of our globe. 

The calcium which they extract from rocks is carried by rivers to the 

sea and is finally deposited in the form of limestones. Springs and 

underground waters charged with carbonic acid exert the same solvent action, but locally and in different degree. We have seen that 

many springs are so heavily loaded with carbonic acid that they 

effervesce when issuing into the air, and such waters are peculiarly 

potent in effecting the solution of-limestones. By percolating waters 

of this class limestone caverns are made, and part of the substance
MINERAL WELLS AND SPRINGS. 205

dissolved is redeposited as stalactite or stalagmite. In reactions of 

this kind the general character of a water is not changed; it may be 

a calcium carbonate water throughout its.course, varying only in 

gaseous content and in concentration, and its chemical effectiveness 

is shown by its work as a carrier in transporting from one point to 

another the material that it has dissolved.1

Alkaline waters, especially thermal waters of the sodium carbonate 

class, are also active solvents of mineral substances. Their tendency, 

however, is opposite to that of the acid waters, for they dissolve silica 

rather than bases, and act as precipitants for magnesia and lime. 

When solutions of calcium sulphate and sodium carbonate are commingled, calcium carbonate is thrown down and an equivalent amount 

of sodium sulphate remains dissolved. Since natural waters are 

rarely, if ever, chemically equivalent, reactions of this sort between 

them are necessarily incomplete, and the blended solutions will contain one group of ions in excess over the other. Thus a water of 

mixed type is produced, but the mixture is not an average of the 

two solutions, for part of their original load has been removed. This 

is a simple case of reaction, but it may be complicated in various 

ways, and even reversed. For instance, a solution of sodium sulphate in presence of free carbonic acid will dissolve calcium carbonate, forming sodium bicarbonate and a precipitate of gypsum. 

E. W. Hilgard 2 has investigated this transformation, and regards 

it as the principal source of alkaline carbonate solutions in nature. 

Furthermore, mineral substances with which alkaline waters come in 

contact may be profoundly modified, as at the thermal springs of 

Plombieres in France. Here, according" to Daubr^e,3 the brickwork 

and masonry of the ancient Roman baths have been strongly attacked 

with the production of hyalite and a number of zeolitic minerals.

Many mineral springs contain organic matter, presumably in the 

form of the so-called humus acids, but the influence exerted by these 

substances is more pronounced in swamp and river waters.4 Their 

supposed solvent action upon rocks and soils has already been 

noticed, as well as their alleged efficiency in retaining silica in solution. 

Against these suppositions I may cite an observation by C. A. Davis, 

of the United States Geological Survey, that the peat of the Dismal 

Swamp contains the siliceous skeletons of diatoms whose outlines 

are still perfectly sharp, without the slighest trace of blurring. This

1 On the magnitude of erosion by subterranean waters see H. Schardt, Bull. Soc. neuchateloise sci. nat., 

vol. 33,1907, p. 168.

8 Am. Jour. Sci., 4th ser., vol. 2,1896, p. 100.

8 Etudes synthe'tiques de geologic exp<5rimentale, 1879, pp. 179 et seq. Other localities at which similar 

changes have been observed are also described. The Plombieres water is said to bo a very dilute solution 

of alkaline silicates, but its exact composition is not given by Daubrce. Analyses of six waters from Plombieres can be found in Les eaux minerales de la France, by E. Jacquot and E. Willm, Paris, 1894, p. 224. 

They confirm Daubrtfe's statement.

4 See Chapter III for details on this subject. Also A. A. Julien, Proc. Am. Assoc. Adv. Sci., vol. 28,1879, 

p. 311.
\

206 DATA OF GEOCHEMISTRY.

observation has been confirmed by Chase Palmer. The water ^ 

saturating the peat contains much dissolved organic matter, which 

colors it strongly brown, and also contains floating diatoms.

Furthermore, iron and alumina may be removed from sulphate or 

chloride waters by the action of limestones. If the iron is in the -. 

ferrous state, it must first be oxidized to the ferric condition. Then, 

by means of calcium carbonate, both of the bases named can be pre- ~« 

cipitated, either as hydroxides or as basic sulphates. Insoluble compounds of the latter class are often formed from natural waters, and ^ 

many mineral species are of that character. It is quite probable that . 

limestone is also effective in removing other heavy metals from their 

solutions; copper, for example, is certainly thrown down, but these 

reactions need to be more fully investigated. Their consideration >* 

must be deferred until we reach the subject of metalliferous deposits.

Finally, the character of a water may be greatly changed by simple 

percolation through the soil. That potassium is thus removed from 

natural waters has long been known, and reference to this fact was 

made in a previous chapter. Experiments by J. T. Crawley and 

R. A. Duncan1 on Hawaiian soils show that a layer 6 inches thick -t 

will fix over 98 per cent of the potassium in a solution of potassium 

sulphate which is allowed to filter through it, and the retention of 

phosphoric acid and ammonia is even more complete. According to 

J. M. van Bemmelen,2 basic zeolitic silicates are the chief agents in } 

effecting the retention of potassium, exchanging other bases for it 

by double decomposition, but the existence of such compounds in the 

soil is not well established. Hydrous aluminum silicates may be the 

effective absorbents, or, in the case of phosphoric acid, the hydroxides 

of aluminum and iron. After potassium and ammonium, Van Bern- *- 

melen finds that magnesium is most readily absorbed, then sodium, 

and calcium least of all. It is clear, however, that the nature of the 

soil must be taken into account. A sandy soil or an impervious clay 

would be less effective in removing saline substances from water than 

a loose loam rich in hydrous basic compounds. The fact that substances are taken from waters by soils is certain, but the extent of - 

the absorption depends upon local conditions. It is also certain that 

potassium, rather than sodium^ is thus withdrawn from aqueous 

circulation.

A careful consideration of all the evidence concerning mineral 

springs will show that it is exceedingly difficult to generalize on relations between the composition of a water and its geological history. * 

Reactions which take place deep within the earth can not easily 

be traced, especially as a water may undergo various modifications 

before it reaches the surface. A spring may be a blend from different 

sources either a direct mixture or a solution from which ingredients

1 Jour. Am. Chem. Soc., vol. 25,1903, p. 47. See also vol. 24,1902, p. 1114.

2 Landw. Versuchs-Stationen (Berlin), vol. 21, p. 135.
MINERAL WELLS A$FD SPRINGS. 207

have been removed and it is only in specific cases that a simple 

interpretation of the phenomena can be found. The water that rises 

from a salt bed or from gypsum is easily understood, and so also is. 

one which carries sulphates derived from, pyritiferous shales. We can 

see that a water from granite must differ greatly from one issuing out 

of limestone, and Hanamann's analyses of the Bohemian rivers illustrate this order of dissimilarity. Many regularities can be traced, 

but no general principle can be deduced from them. For example, 

A. De Lapparent 1 shows that solfataras are most common in regions 

of highly siliceous eruptive rocks, such as rhyolites, andesites, etc., a 

condition which he attributes to the inferior fluidity of the volcanic 

magmas and the consequently greater retention of gaseous contents 

by them. In areas of subsilicic rock solfataras rarely or never occur. 

Various attempts have been made to correlate the composition of 

waters with the geological horizons from which they ; flow. For 

spring waters such attempts are of little value, because two springs, 

side by side, may be widely different. In the case of artesian wells 

the problem is perhaps simpler, for there the horizon can be determined. Artesian waters of common origin often show a family 

likeness to one another, especially in their minor constituents, one 

group being always calciferous, another relatively rich in bromine, 

and so on.2 But no law can be framed to cover even these regularities, 

for the exceptional waters are too numerous and too confusing. That 

waters from sedimentary rocks are, as a rule, more concentrated and 

perhaps more complex than those from the older crystalline forma~ 

tions is doubtless true; but beyond that it is hardly safe to generalize. 

It is better to discuss each water by itself, and so seek to interpret 

its individual history.

VADOSE AND JUVENILE WATERS. 3

Whether it is possible to discriminate between waters of superficial 

or vadose origin and magmatic or deep-seated waters is a question 

for geology to answer. Until quite recently the prevalent opinion 

has been that all spring waters, including those emitted, by geysers, 

were originally meteoric. Modern investigations into volcanism and 

upon the subject of metalliferous veins have, however, led to a' 

reopening of the question. E. Suess,4 speaking with especial refer1 Compt. Eend., vol. 108,1889, p. 149. .

2 A. C. Lane (Water-Supply Taper U. S. Geol. Survey No. 31,1899) classifies the Michigan waters with 

reference to their origin, and points out various similarities connected with identity of horizon. On the 

chemical relations between spring waters and the rocks from which they issue, see M. Dittrich, Mitth. 

Badisch.geol. Landesanstalt, vol. 4,1901, p. 199.

sThe term "connate" is also used to some extent to describe buried or fossil waters. The calcium 

chloride waters of the Lake Superior region have been assigned to this class.

«In Verhandl. Gesell. Deutsch. Naturforscher und Arete, 1902. Abstractin Geog. Jour., vol. 20, p. 520, 

1902. On the other hand, see E. H. L. Schwarz, Geol. Mag., 1904, p. 252; and J. M. Maclaren, idem, 1900, 

p. 511. These writers regard the hot waters of Africa and New Zealand as originally vadose. The same 

conclusion is reached by Arnold Hague relative to'tho geyser waters of the Yollowstone National Park. 

See Scribner's Mag., May, 1904, p. 513, and Trans. Am. Inst. Miu. Eng., vol. 16,1887, p. 7S3; also his presidential address in Bull. Gool. Soc. America, vol. 22,1911, p. 103, and Science, vol. 33, p. 555.
208 DATA OF GEOGHEMISTBY.

ence to the thermal springs of Carlsbad, has advanced strong arguments to show that waters of this class are "juvenile" and now see 

the light of day for the first time that is, they issue from deep 

within the earth, from the fundamental magma itself, and bring up 

veritable additions to the hydrosphere. These magmatio waters, 

furthermore, are regarded by some authorities as the carriers of 

metallic salts, by which certain kinds of metalliferous veins have been 

filled.1

This subdivision of springs into vadose, or those which represent 

original infiltration of surface waters, and juvenile, as Suess terms 

them, has had wide but not universal acceptance. A difficulty in 

applying the proposed nomenclature arises from the fact that it is not 

easy to determine where a given water belongs. Armand Gautier,2 

however, has pointed out several criteria which may make discrimination possible. He shows that vadose waters, or waters of infiltration, are characterized by fluctuations in composition, concentration, and rate of flow, depending upon local and variable conditions, 

such as abundant rain or drought. They also contain, as a rule, 

carbonates of lime or magnesia, chlorides, and sulphates. Virgin or 

juvenile waters, on the contrary,.are fairly constant in all essential 

particulars, and carry sodium bicarbonate, alkaline silicates, heavy 

metals, etc., as chief constituents, with chlorides or sulphates only 

as accessories, and practically no carbonates of the alkaline earths. 

The vadose waters, moreover, issue from faults having no relation to 

the metallic veins of the surrounding territory a lack of relation 

which is conspicuous as regards juvenile springs. Gautier holds 

that hydrogen emitted from the hot interior of the earth acts as 

a reducing agent upon metallic oxides and so forms the magmatic 

water of the springs. With the water thus generated, other water, 

that of constitution from minerals like the micas, is com mingled.

THERMAL SPRINGS AND VOLCANXSM.

The work of Gautier just cited is intimately related to an earlier 

memoir,,3 in which the close connection between volcanism and the 

formation of thermal springs is shown. His work will be considered more in detail in a later chapter, but his general conclusions 

may be cited now. When a crystalline rock, like granite, is heated 

to redness in vacuo, water and gases, the latter identical in character 

with the volcanic gases, are given off. For instance, to cite the least

1 See, for example, W. Lindgren, Eng. and Min. Jour., vol. 79,1905, p. 460. Also A. C. Spencer, Trans. 

Am. Inst. Min. Eng., vol. 35,1905, p. 473; vol. 36,1906, p. 364.

2 Compt. Rend., vol. 150,1910, p. 436. Other papers bearing on this subject, and on the origin of the 

carbon dioxide of mineral waters are by R. Delkeskamp, Zeitschr. gesammte Kohlensaure-Industrie, 1906, 

Nos. 18-21; L. De Launay, Annales des mines, 10th ser., vol. 9,1906, p. 5; F. Henrich, Zeitschr. prakt. 

Geologie, 1910, p. 85; and 0. Stutzer, idem, p. 346.

a Annales des mines, 10th ser., vol. 9,1906, p. 316. A good abstract by F. L. Ransome is given in Econ. 

Geology, vol. 1, 1906, p. 088.
MINERAL WELLS AND SPRINGS. 209

significant example, 1 cubic kilometer of granite can yield from 25 

to 30 millions of metric tons of water, which at 1,100° would form 

160,000,000,000 cubic meters of steam. In addition to this enormous 

volume of vapor 28,000,000,000 cubic meters of other gases would be 

emitted. Suppose, now, that by fissuring and subsidence in the lithosphere such a mass of rock were carried down to a depth of 25,000 to 

30,000 meters. It would then be in the heated regions, and the evolution of vapors under great pressures would occur. To some such 

changes Gautier ascribes the phenomena of volcanism, with all its 

development of solfataras and fumaroles. Ordinary thermal springs 

may be formed by the same process, operating; perhaps, less violently, 

and originate, so to speak, from a sort of distillation of the combined 

water contained in the depressed masses of rock. In an earlier 

memoir * Gautier has shown that granite, heated with water in a 

sealed tube to a temperature between 250° and 300°, yields solutions 

containing sulphur compounds and resembling the sulphur waters of 

hot springs. This sulphur he ascribes, not to the decomposition of 

metallic sulphides, but to reactions upon sulphosilicates, a class of 

compounds represented in nature by hauynite and lazurite,2 and also 

by certain artificial substances which Gautier himself has prepared. 

He also supposes that carbon oxysulphide, COS, may be formed in the 

terrestrial nucleus, possibly from carbon monoxide generated by reactions between oxides and metallic carbides. Here he enters the field 

of speculation, where it is not necessary for us to follow him. The 

reactions which he has experimentally established are sufficiently 

suggestive, and his broad general conclusions are entitled to the most 

respectful consideration.

And yet, notwithstanding all that has been written on the subject, 

the controversy over the genesis of hot springs is not closed. What 

is the origin of the carbon dioxide with which so many mineral 

waters are heavily charged? In some .instances, doubtless, it is 

derived from the decomposition of limestones, but in others this explanation can not suffice. Here and there it may be, to use Suess's 

expression, "juvenile," and evidence of the deep-seated origin of a 

spring.3 Again, whence comes the sodium chloride of waters that 

flow from sources where it could not have been previously laid down ? 

These questions and others like them still await satisfactory answers. 

With mere suppositions, however plausible they may seem, we can not 

be content.

A word in conclusion on the radioactivity of spring waters. A very 

large number of such waters possess this property, but no distinction

1 Compt. Rend., vol. 132, 1901, p. 740.

a Helvite and danalite are other natural sulphosilicates which might easily take part in the supposed 

reactions.

s On vadose and juvenile carbonic acid in waters, see an elaborate discussion by R. Dclkeskamp, 

Zeitschr. prakt. Geologie, 1906, p. 33; reviewed by W. Lindgren, Econ. Geology, vol. 1,1906, p. 602.

113750° 19 Bull. 695 14
210 . DATA OF GEOCHEMISTRY. .. '

between-vadose-and .juvenile .waters, can be-based .upon the observations.. -Waters of both classes.are radioactive, but.the.phenomenon 

is perhaps most common among waters of volcanic origin, or at least 

among thermal springs. In the United States the Ho.t Springs of 

Arkansas have' been studied by B. B. Boltwood. 1 The springs of 

Missouri 2 and the Yellowstone National Park 3 were investigated by 

H, Schlundt and K,. B. Moore. In each of these researches radioactivity was-generally detected, but with varying intensity within the 

same group of springs. On the "radioactivity of European waters 

there is a copious literature.

BIBLIOGRAPHIC NOTE.

The following collections of water analyses will be found useful for 

reference:

F. RASPE. Heilquellen-Analysen, Dresden, 1885. A very large collection of analyses,

mainly of European mineral waters. 

T. E. THORPE. Dictionary of applied chemistry, article "Water," vol. 3, pp. 952-959,

1893. Tables of analyses of European mineral springs. The same article

gives much information about other waters. 

J. K. CROOK. The mineral waters of the United States, New York and Philadelphia,

1899. 

A. C. PEALE. The mineral springs of the United States: Bull. U. S. Geol. Survey

No. 32, 1886. 

F. A. GOOCH and J. E. WHITFIELD. Analyses of waters of the Yellowstone National

Park: Bull. U. S. Geol. Survey No. 47, 1888. 

E. ORTON. Rock waters of Ohio: Nineteenth Ann. Kept. U. S. Geol. Survey, pt. 4,

1898, p. 633. Contains many analyses of deep wells from various horizons. 

W. H. NORTON. Artesian wells of Iowa: Iowa Geol. Survey, vol. 6,1896, pp. 117-428. 

J. H. SHEPHERD. Artesian wells of South Dakota: Bull. Agr. Exper. Sta. South

Dakota No. 41, 1895. 

J. C. BRANNER. Mineral waters of Arkansas: Ann. Kept. Geol. Survey Arkansas,

1891, voL 1. 

E. H. S. BAILEY and others. The mineral waters of Kansas: Kansas Univ. Geol.

Survey, vol. 7, 1902. 

P. SCHWEITZER. A report on, the mineral waters of Missouri: Geol. Survey Missouri,

vol. 3,1892. 

W. S. BLATCHLEY. The mineral waters of Indiana: Twenty-sixth Ann. Kept. Indiana

Dept. Geology and Nat. Resources, 1901, pp. 11-225. 

A. C. LANE. The mineral waters of lower Michigan: Water-Supply Paper U. S. Geol.

Survey No. 31,1899. 

S. W. McCALLiE. Preliminary report on the mineral springs of Georgia: Bull. Geol.

Survey Georgia No. 20,1913. 

W. ANDERSON. Mineral springs and health resorts of California, San Francisco, 1892.

Contains many analyses, the greater number of them by the author. 

G. A. WARING. Springs of California: U. S. Geol. Survey Water,-Supply Paper

No. 338,1914.

1 Am. Jour. Sci., 4th ser., vol. 20,1905, p. 168.

2 Trails. Am. Electrochem. Soc., vol. 8, 1905, p. 291. Schlundt, Jour. Phys. Chem., vol. 18, p. 663,1914, 

has also studied the radioactivity of Colorado springs. See also O. C. Lester, Am. Jour. Sci., 4th ser., 

vol..46,1918, p. 621.

» Bull. U. S. Geol: Survey No. 395,1909.
MINERAL WELLS AND SPRINGS. 211

G. A. WARING. Mineral springs of Alaska: U. S. Geol. Survey Water-Supply Paper

No. 418, 1917. 

R. T. ELSWORTHY. Mineral springs of Canada: Canada Dept. Mines, Mines Brand),

Bull. No. 20, pt. 2,1918. 

L. DE LAUNAY. Recherche, captage et am6nagement des sources thermornine'rales,

Paris, 1899. 

A. CARXOT and others. Analyses of French and colonial mineral waters: Annales

deamines, 8th ser., vol. 7,1885, p. 79; 9th ser., vol. 6,1894, p. 355; vol. 16,1899,

p. 33. These three papers contain 584 analyses. 

E. JACQUOT and E. WILLM. Les eaux mine'rales de la France, Paris, 1894. Many

analyses and descriptions of the springs.

 GUYON. Etudes sur les eaux thermales de la Tunisie, Paris, 1864. 

M. HANRIOT. Lea eaux mine'rales de I'Alg&ie, Paris, 1911. 

A. RAIMONDI. Aguas minerales del Peru: El Peru, estudios mineralogicos y geo!6gicos,

vol. 4, 1902, pp. 235-394.

L. DARAPSKY. Aguaa minerales de Chile, Valparaiso, 1890. 

E. H. DUCLOUX. Aguas minerales alcalinas de la Republica Argentina: Revista

Museo de la Plata, vol. 14, pp. 9-52, 1907. Other analyses are in vol. 16,

pp. 51-120, 1909. 

E. ABELLA Y CASARIEGO and J. DE VERA Y GdMEZ. Estudio descriptive de algunaa

manantiales minerales de Filipinas, Manila, 1893. 

A. LIVERSIDGE, W. SKEY, and G. GRAY. Rept. Australasian Assoc. Adv. Sci., 1898,

pp. 87-108. A collection of analyses of Australasian mineral waters. 

R. ISHIZU. The mineral springs of Japan. Tokyo, 1915. 

DEUTSCHES BADERBUCH. Leipzig, 1907. A compendium of information relative

to the mineral springs of Germany.

Many other analyses of waters are scattered through the periodical 

literature of chemistry, geology, pharmacy, and medicine, and the 

reports of geological surveys. The publications of agricultural experiment stations also contain much material relative to. artesian, well, 

spring, ground, and drainage waters.' DaubreVs three volumes on 

"Les eaux souterraines" contain few analyses, but much information 

upon mineral springs. T. Sterry Hunt, in his "Chemical and geological essays," also has much to say upon the origin of natural waters 

and their chemical relations to one another. Bulletins 91 and 139 

of the Bureau of Chemistry, United States Department of Agriculture, contain many analyses of American mineral waters.
CHAPTER VII.

SALINE RESIDUES. 

DEPOSITION OF SALTS.

When a natural water is concentrated by evaporation it deposits 

its saline constituents in the .reverse order of their solubility, the least 

soluble first, the most soluble last of all. The process, however, is 

not so simple as it might appear to be, for the solubility of a salt in 

pure water is one thing and its solubility in the presence of other 

compounds is another. Each substance is affected by its associates, 

and its deposition is partly a matter of concentration and partly a 

question of temperature. In general, the character of a saline deposit 

can be predicated from the character of the water which yields it; 

a chloride water gives chlorides, a sulphate water sulphates, and 

waters of mixed type furnish mixtures of compounds or even double 

salts. The more complex the water the greater becomes the range 

of possibilities.

We have already seen, in our studies of river, sea, and spring 

waters what a variety of reactions lead to the deposition of insoluble 

sediments. By this expression I do not mean sediments of suspended 

matter, like clays, but precipitates from solution, such as sulphur, 

hydroxide of iron, sinters, tufas, and so on. These substances represent something more than the results of simple evaporation, for they 

are produced by cheimical changes, like oxidation, loss of carbonic 

acid, etc. We have now to consider the consequences of evaporation 

itself, and of the opposite process, re-solution, in which nothing is 

added to or taken away from the reacting system but water, except 

in so far as the soluble salts are successively deposited and so removed 

from the sphere of chemical change. In salt and alkaline lakes we 

can recognize several stages of this process the precipitation of the 

relatively insoluble calcium sulphate, then of salt or sodium sulphate, 

the production of bitterns, like the water of the Dead Sea, and finally 

of solid beds of various saline materials. What are these saline residues, and what conditions govern their formation ?

The most important of these substances, considering the magnitude 

of the deposits, are sodium chloride and calcium sulphate, and their 

most probable origin is the evaporation of sea water or its equivalent 

in either ancient or modern tunes. The two compounds are commonly 

associated the one with the other, but not invariably, for gypsum is 

sometimes derived from other sources, and rock salt may be dissolved 

212
SALINE RESIDUES. 213

and washed away from a given locality, perhaps to be redeposited 

elsewhere. Still, the concentration of salt water, either from the 

ocean, or from lakes, is the principal source of these deposits, and 

that phenomenon we may well consider in detail. The process has 

been going on from Cambrian time down through all the intervening 

ages to the present day, and it can be observed in actual operation in 

many accessible localities. A salt lake dries up, or a body of water 

is cut off from the sea by a bar, and so permitted to evaporate, and 

a bed of salt is formed. Such beds are lenticular in form thick at 

the centers, where the water was deepest, and thinning out toward 

the edges; and they show, as a rule, the same alternation of material, 

but with variations in regard to completeness. In general, the following alternations are observed: First, precipitates are formed, such 

as were considered in our discussion of mineral springs; then calcium 

sulphate is deposited, then salt, and finally, under exceptionally 

favorable conditions, layers of the more soluble compounds which 

characterize ordinary bitterns. This order, however, is subject to 

seasonable disturbances. In the concentration of a salt lake the deposits vary with the temperature, the summer and winter phenomena 

being often unlike. Again, evaporation goes on during a dry season, 

to be interrupted by a flood; and in the latter case layers of silt are 

deposited from time to time over the saline compounds that had 

previously formed. Alternations of gypsum, salt, and clay are exceedingly common in saline deposits. In a lagoon, cut off from the 

ocean, a break of the sandy barrier or an exceptionally high tide may 

admit a fresh supply of material for concentration,.and so interrupt 

the continuity of the process. Any change of conditions will cause 

a corresponding change in the character of the substances laid down. 

Evidently each bed of salt should be studied individually, if its 

history is to be understood; but the general phenomena in the concentration of sea water appear more or less completely in every case 

and in essentially the same order.

CONCENTRATION OF SEA WATER.

In 1849 J. Usiglio 1 published an elaborate study of saline deposits 

from Mediterranean water, the samples having been taken at sea, 

near Cette, but several miles from shore and at a depth of 1 meter. 

The water itself was analyzed, the order and quantity of the salts 

deposited at various concentrations were determined, and analyses 

were also made of three bitterns, representing different densities and 

different stages of the process. The four analyses, reduced to ionic 

form and to percentages of total solids, appear in the following table.

' Annales chim. pbys., 3d ser., vol. 27,1849, pp. 92,172.
DATA OF GEOCHEMISTRY.

Analyses of Mediterranean water and bitterns.

A. The water itself, density 1.0258, 

B/Eittern of density 1.21.

C. Bittern of density 1.264. 

P. Bittern of density 1.32.

Cl................................... ..........

Br. ...........................................

SQ4 . ........................................

C03 - .........................................

Na....... ...................................

K............................................

Ca ...........................................

Mg......... ..................................

A

54.39

1.15

7.72

.18

31.08

.71

1.18

3.59

100. 00 

3.766

B

56.18

1.22

5.78

32.06

.78

.26

3.72

100. 00 

27. 546

C

49.99

2.68

14.64

20.39

2.25

10.05

100.00 

33. 712

;D

49.13

3.03

17. 36

12.89

3.31

14.28

100. 00 

39. 619

The determinations of bromine in these analyses are obviously 

excessive and those of potassium are low, but otherwise the data in the 

first column, considering the time when they were made, agree fairly 

well with the more recent figures given in Chapter III of this volume. 

They show, first, the elimination of calcium as carbonate, and later 

as sulphate, then the deposition of sodium chloride, and finally the 

accumulation of the more soluble substances in the mother liquors.

In his study of saline deposition Usiglio started with 5 liters of 

sea water, and determined the character and quantity of the salts laid 

down at successive stages of concentration. In the following table 

the results of his experiments appear, but are reduced to the initial, 

unit volume of 1 liter. The quantities given are in grams.

Salts laid down in concentration of sea water.

Density."

1. 0258 

1. 0500 

1. 0836 

1. 1037 

1. 1264 

1. 1604 

1. 1732 

1. 2015 

I. 2138 

1. 2212 

1. 2363 

1. 2570 

1. 2778 

1.3069

Tot 

Salts in k

Su

Volume.

1. 000 

.533 

.316 

.245 

.190 

. 1445 

.131 

.112 

.095 

.064 

.039 

.0302 

.023 

. 0162

al deposit, 

ist bittern.

m .......

Fe203 .

0. 0030

.0030

.0030

' CaCO3 .

0. 0642 

Trace. 

Trace. 

.0530

.1172

. 1172

CaSO4 

2H-0.

0. 5600 

.5620 

. 1840 

. 1600 

.0508 

.1476 

. 0700 

.0144

1. 7488

1. 7488

NaCl.

3. 2614 

9. 6500 

7. 8960 

2. 62*0 

2. 2720 

1. 4040:

27. 1074 

2. 5885

29. 6959

MgS04 .

6. 0040 

. 0130 

. 0262 

.0174 

.0254 

. 5382

.6242 

1. 8545

2..478T

MgCl2 .

0. 0078 

.0356 

. 0434 

.0150 

.0240 

. 0274

.1532 

3.' 1640

3. 3172

NaBr.

0. 0728 

.0358 

.0518 

. 0620

. 2224 

. 3300

.5524

KCl.

0.5339

.5339

a Given by Usiglio in Baume" degrees. Restated here in the usual specific gravities.
SALINE RESIDUES. 215

Upon further concentration of the mother liquors Usiglio obtained 

variable results. Mere cooling from the temperature of day to that 

of night was sufficient to precipitate additional magnesium sulphate, 

which redissolved partially the day following. After that more salt 

was thrown down, then the double sulphate of magnesium and potassium, next the double chloride of the same metals, and finally magnesium chloride crystallized out. In the table of results just given 

the order of deposition is clearly shown. First, ferric oxide and 

calcium carbonate; then gypsum; then salt, the latter beginning to 

appear when the water had been concentrated to about one-tenth of 

its original volume.

In its general outlines, then, the concentration of sea water is a 

simple phenomenon, but in its details it may be very complex. The 

localities at which it can be completely traced are comparatively few 

and the natural records of it are, as a rule, defective. The mother 

liquors are easily drained or washed away, leaving no trace of their 

existence, and some saline deposits'have been partially redissolved 

and laid down with modified composition elsewhere. Salt and gypsum may thus be separated, and so the normal order of their association becomes disturbed. Beds of salt, therefore, may be divided 

into classes as primary and secondary, or as complete and incomplete, according to their saline character or the evidence of their 

origin. Of all known localities the region around Stassfurt, in Germany, gives us the best record of the complete, or nearly complete, 

process, and as it has been studied with unusual thoroughness we may 

properly consider it in some detail.

Ocean water, as we have already seen, contains on the average 

about 3.5 per cent solid matter in solution, so that the mere evaporation of a closed lagoon would give a layer of salt of only moderate 

thickness. But salt deposits may be enormously thick a thousand 

meters or more, as at Sperenberg, near Berlin and the existence of 

such masses requires some explanation. For this purpose we must 

assume that large quantities of brine have accumulated within a 

limited space, such as a deep valley, like that of the Dead Sea, or 

behind a bar, as suggested by G. Bischof,1 and more recently by 

C. Ochsenius.3 The theory developed by Ochsenius is briefly as follows: Let us imagine a deep bay, connected with the sea by a narrow 

and shallow channel, but otherwise cut off from oceanic circulation by 

a bar. If no large streams enter the bay the outflow from it will be 

small, but sea water can enter freely to offset the losses due to evaporation. Evaporation, of course, takes place only at the surface,

1 Lehrbuch der chemischen und physikalischen Geologic, 2d ed., vol. 2,1864, p. 48.

" Die Bildung der Steinsalzlager und ihrer Mutterlaugensalze, Halle, 1877. See also a short paper in 1'roc. 

Acad. Nat. Sci. Philadelphia. 1888, p. 181. Ochsenius was sharply criticized by J. Walther in Das Gosetz 

der Wiistenbildung, Berlin, 1900. Ochsenius replied in Centralbl. Min., Geol. u. PaL, 1902, pp. 551, 557, 

620; and a rejoinder by Walther appeared in the same journal, 1903, p. 211. See also O. E. Branson, Bull. 

Geol. Soc.-America, vol. 26, p. 231,1915.-
216 DATA OF GEOCHEMISTRY.

and the upper layers, thus becoming denser, must sink, so pro- ^ 

ducing a saline concentration at the bottom. In this manner, being 

continually supplied with new material from without, the salinity of "*" 

the bay will gradually increase until saturation is reached and the ' L 

deposition of salt begins. So long as salt water can enter the bay 

this process will continue, and the depths of the basin will, in time, 

become a solid mass of salts, covered with a sheet of bittern. If, 

meanwhile, an elevation of the land takes place, separating the bay 

completely from the ocean, evaporation may proceed to its limit and 

the mother liquor will deposit its contents. In the Karaboghaz 

and other bays on the eastern shore of the Caspian Sea the process 

of saline concentration can now be observed in actual operation; 

but only a part of the program has yet been performed,

This theory of Ochsenius, however, is not the only one possible 

to account for the concentration of salt. It must be remembered '*- 

that salt is not deposited from sea water until the latter has been 

concentrated to about one-tenth of its original volume. Suppose, 

now, a large sheet of water to be cut off from the ocean by any change 

in the level of the land, and also that it contains within its area a 

deep depression. In that depression the water will gradually become 

concentrated, and its saline load'will tend to accumulate there. The flayer of salt in the depression would be of much greater thickness 

than one formed by evaporation over a comparatively level bottom, 

and if the surface area of the depression were small in comparison l 

with that of the original sheet of water, the depth of the deposit 

might be very great. Such a deposit might also be reinforced by 

leachings from other salt beds, or from diffused salt in adj acent areas, ' 

a process which is now going on in the valley of the Dead Sea.

THE STASSFTJRT SALTS. \

In the Stassfurt, or, more properly, the Magdeburg-Halberstadt 

region, the order of deposits is as follows, going from the surface 

downward :'

i From data given by H. Precht in Die Salz-Industrio von Stassfurt und Umgegend, 1889; L. Loewe, 

Zeitschr. prakt. Geologic, 1903, p. 331; H. M. Cadell, Trans. Edinburgh Geol. Soc., vol. 5,1884, p. 92; and 

G. Lunge in Thorpe's Dictionary of applied chemistry, vol. 3, p. 265. See also C. Ochsenius, on Loewe's 

paper, Zeitschr. prakt. Geologie, 1904, p. 23; and on the potash salts, idem, 1905, p. 167. J. Westphal 

(Zeitschr. Berg-, Hiitten- u. Salinenwesen preuss. St., vol. 50,1902, p. 1) has given a history of the Stassfurt 

works. An important monograph is that of E. Pfeifler, Handbuch der Kali-Industrie, Braunschweig, 

1887. For a paper by J. Currie, see Trans. Edinburgh Geol. Soc., vol. 8,1905, p. 403. Other references may 

be found in a bibliography of saline minerals, Zeitschr. prakt. Geologie, 1905, p. 183. Deutschlands Kalibergbau, Berlin, 1907, contains papers on the geology of the saline beds by H. Everding, and their chemistry, by E. Erdmann, with exhaustive bibliographies. See also W. Riemann, Die Geologie der deutschen '*"* 

Salzlagerstatten, Stassfurt, 1908; and H. E. Boeke, Uebersicht der Mineralogie, PetrograpMe und Geologie 

der Kalisalzlagerstiitten, Berlin, 1909. Many papers relative to the salt deposits are in the journal Kali; 

but they can not all be noticed here. A recent paper by O. Riedel is in Zeitschr. Kryst. Min., vol. 50,1912, 

p. 139. On the quantitative composition of the Stassfurt beds sec M. R<5zsa, Zeitschr. anorg. Chemie, vol. 

90, 1915, p. 377, and on chemical changes in the salts, idem, vol. 94,1916, p. 92. For a general review of 

oceanic salts see E. Janecke, Zeitschr. anorg. u. allgem. Chemie, vol. 100,1917, pp. 161,176; vol. 102,1918, « 

p. 41; vol. 103,1918, p. 1. ^
SALINE RESIDUES. 217

1. Drift, about 8 meters thick. 

. 2. Shales, sandstones, and unconsolidated clays, of varying thickness.

3. Younger rock salt, thickness very variable, sometimes missing.

4. Anhydrite, rarely lacking, 30 to 80 meters thick.

5. Salt clay, average thickness 5 to 10 meters, very rarely absent.

6. The carnallite zone, from 15 to 40 meters thick. At Douglashall a layer of rock 

salt intervenes between the carnallite and the clay. In parts of the field 

kainite overlies the carnallite, is itself overlain by "sylvinite" or "hartsalz," 

and that in turn by schoenite. These subzones are often missing.

7. The kieserite zone.

8. The polyhalite zone.

9. Older rock salt and anhydrite. Nos. 7, 8, and 9 have a total thickness ranging 

from 150 to perhaps 1,000 meters. The. anhydrite forms layers, averaging 

7 millimeters thick, separating the salt into sheets of 8 or 9 centimeters. These 

layers have been interpreted as annual deposits, due possibly to seasonal 

variations in temperature or to alternating drought and rain. ' If this supposition is correct, a Stassfurt salt bed 900 meters thick would require 10,000 years 

to form.

10. Anhydrite and gypsum.

We have now a complete record of the saline deposition at Stassfurt, ranging from the calcium sulphate at the bottom to the mother 

liquor or carnallite salts at the top. Above the carnallite a protecting layer of clay was laid down; and, after that, probably, a new 

accession of sea water began the formation of a second series of 

beds.1 This younger salt and its underlying anhydrite represent this 

later period, which has no chemical relation to the first. So much 

for the broad outlines. Now let us pass on to the details of the 

record.

In the Stassfurt deposits more than 30 saline minerals are 

found, some abundantly and some sparingly. Several of them are 

regarded as primary minerals; others are derived from these by 

secondary reactions; a few of the species are simply salts, but the 

greater number are double compounds. Chlorides, sulphates, and 

borates are the characteristic substances, but in kainite we have a 

mixed salt containing two acid radicles, and the rare sulphoborite is 

another example of similar complexity. Carbonates are represented but sparingly, and their normal occurrence is probably that 

of the "stinkstone," or bituminous limestone, which has been found 

beneath the anhydrite. Native sulphur, derived from anhydrite 

by the reducing action of organic matter, is sparingly present in the 

salt clay,2 and more abundantly in the rock salt and carnallite. 

Pyrites also is sometimes found in the deposits. Bromine is present

> Some writers regard the younger salt as having been formed by re-solution of older salt and redeposition 

here. As the discussion is geological and not chemical, it is unessential to our present purposes.

spfeifler, Arch. Pharm., 3d ser., vol. 27,1890, p. 1134. On the salt clay see E. Marcus and W. Eiltz, 

Zeitschr. anorg. Chomie, vol. 68,1910, p. 91. .Vanadium was detected in it. See also Marcus, idem, vol. 

77, p. 119,1912, for many analyses.
218 DATA OF GEOCHEMISTRY.

in the salts and also iodine, 1 and copper is reported 'by W. -Biltz and 

E. Marcus, as well as ammonium and nitrates.2 Helium occurs in 

the salts in traces.3

The essential compounds are chlorides and sulphates, and as the 

latter are represented by the oldest of the important strata they may 

be considered first. The sulphates found at Stassfurt are as follows:

Anhydrite. ..................... .CaS04 .

Gypsum 4 . ....................... CaS04,2H20.

Glauberite. .................... . .CaS04 .Na2S04 .

Polyhalite. .................... . .2CaS04 .MgS04 .K2S04 .2H20.

Krugite. ....................... .4CaS04 .MgS04 .K3S04 .2H20.

Kieserite. ...................... .MgS04 .H20.

Epsomite. ....................... .MgS04 .7H20 (reichardtite) .

Vanthoffite. ....................... .MgS04 .3NaaS04 .

Bloeditel ......................... .MgS04 .Na2S04 .4H20 (astrakanite).

Loewite. ....................... .MgS04 .Na2S04 .2£E20.

Langbeinite. ................... .2MgS04 .K2S04 .

Leonite. . .......................... MgS04 .K2S04 .4H20.

Picromerite. ...................... .MgS04 .K2S04 .6H20 (sclioenite).

Aphthitalite. .................... .K3Na(S04) 2 (glaserite). 6

Celestite, SrS04 , is also sometimes found in these deposits.

If we now study these compounds with reference to their origin, 

we shall find that the primary deposition followed approximately in 

the order of their hydration. Anhydrous calcium sulphate, anhydrite, forms the lowest member of the series, and gradually merges 

into the older salt. In the latter, glauberite and langbeinite, both 

anhydrous, first appear, although they also occur, always as secondary minerals, higher up. According to H. Precht,0 langbeinite 

replaces polyhalite when the calcium sulphate needed to form the 

latter mineral is present in insufficient quantity. Polyhalite, in 

which the ratio of the sulphate molecules to water is as four to two, 

comes next, forming an important part of the upper layers in the 

older salt, and is followed by the monohydrated kieserite. Krugite, 

which is still lower in hydratiou, occurs with polyhalite in the younger 

salt, so that the two species may be regarded as equivalent and 

contemporaneous. The more highly hydrated species, bloedite,

1 On bromine see H. E . Boeke, Zeitschr. Kryst. Min. , vol. 45, 190S, p. 346. On iodine, A . Frank, Zeitschr. 

angew. Chemic, vol. 20, 1907, p. 1279; E. Erdmann, idem, vol. 23, 1910, p. 342; and K. Kraze, Inaug. Diss. 

Halle, 1909. The presence of iodine in the salts of the Stassfurt region proper is questioned by Boeke, 

Erdmann, and Kraze. Krase, however, found it in the salts from Neu Stassfurt, Bleiche"rode, and Kalusz. 

See also K. Kochlichen, Kali, vol. 7, 1913, p. 457. On rubidium in potash salts see E. Wilkc, Kali, vol. 6, 

1912, p. 245.

2 Zeitschr. anorg. Chemie, vol. C2, 1909, p. 183; vol. 64, 1909, p. 236.

3 R. J. Strutt, Proc. Roy. Soc., vol. 81, ser. A, 1908, p. 278. E. Erdmann, Ber. Deutsch. chem. Gesell., 

vol. 43, 1910, p. 777. S. Valentiner, Kali, vol. 6, 1912, p. 1.

* Probably, as A. Geuther (Liebig's Annalen, vol. 218, 1883, p. 297) has shown, the formula. here given 

to gypsum should be doubled. It then becomes Ca2S«O8.4H2O, and the hcmihydrate, CaoSsOs.H.O, a 

well-known artificial compound, furnishes evidence in favor' of the lilgher formula.

6 According to B. Gossner (Zeitschr. Kryst. Min., vol. 39, 1904, p. 155) glaserite is a definite species with 

the formula given above. J. H. Van't Hoff and H. Barschall (Zeitschr. physikal. Chcinie, vol. £6, 100G, 

p. 212) question the definiteness of the mineral, and regard it as a mixture of tho two component sulphates.

B Zeitschr. angew. Chemie, 1897, p. 68.
SALINE RESIDUES. 219

loewite, picromerite, and leonite, are principally found in the kainite 

region above the carnallite, and epsomite, with its seven molecules 

of water, is deposited in the salt clay. The anhydrous aphthitalite. 

is a secondary mineral in the kainite, and vanthomte, also anhydrous, 

is associated with aphthitalite and loewite in the same horizon. The 

loewite is probably formed by dehydration of bloedite,1 and the 

vanthomte by a reaction between bloedite and sodium sulphate, the 

process being modified by the presence of other substances. The 

langbeinite of the kainite region is commonly regarded as a secondary 

product, but it may have been one of the parent species, for F. R. 

Mallet,2 who has described this mineral as found in the Punjab salt 

range of India, observed that on exposure to moist air it gained 57 

per cent in weight and altered into a mixture of epsomite and picromerite. On the other hand, langbeinite itself may be derived by 

various reactions from other Stassfurt species, such as leonite, 

kainite, Ideserite, and picromerite, as Van't Hoff and Meyerhoffer 

have shown. The fact that a given salt may be produced by several 

different reactions warns us to be cautious in making assertions as 

to its origin at any specified point. Concentration and temperature 

are two of the determining factors in the deposition of salts, and the 

possible reactions are also profoundly modified by the presence of 

other compounds. Van't Hoff and his colleagues have determined 

experimentally many of the conditions under which the Stassfurt 

minerals occur or can be produced, and find that their temperatures 

of formation in a saturated solution of common salt are lower than 

in the absence of that compound. The elaborate researches of these 

authors, however, are not available for abstraction here, partly, 

because they are complicated by diagrams, and partly because the 

investigations are not yet complete. Only in a special monograph 

upon the Stassfurt beds could all the details of their investigations 

be adequately discussed.3

The chlorides found in the Stassfurt region are as follows:

Halite or rock salt, NaCl.

Sylvite, KC1. "Sylvinite" is a mixture of sylvite and rock salt, while the "Hartealz" contains these substances together with kieserite. 

Douglasite, K2FeCl4 .2H20.(?) 

Carnallite, KMgCl3 .6H20.

Tachhydrite, 2MgCl2 .CaCl2 .12H20=3(RCl2.4HsO).4 

Bischofite, MgCl2 .6H30.

» See !l. H. Van't Hoff, Sitzungsb. Akad. Berlin, 1902, p. 41-1. Also Vant Hoff and W. Meyerhofler, 

Idem, 1903, p. 67S; 1904, p. 659.

* Mineralog. Mag., vol. 12,1899, p. 159. : 

B Van't Hoff and his associates have already published about fifty papers on the Stassfurt salts, in 

Sitzungsb. Akad. Berlin, from 1897 to 1907. See also Van't Hoff, Physical chemistry in the service of the 

sciences, Chicago, 1903; Zur Bildung der ozeanischen Sakablagerungen, Braunschweig, 1905; and an 

address in Ber. Intemat. Kong, angew. Chemie, Berlin, 1903. Also summaries by E. F. Armstrong, Proc. 

British Assoc. Adv. Sci. 1901; p. 262, and E. Janecke, Zeitschr; anorg. Chemie, 190C, p. 7. For a graphic, 

representation of the saline associations see also H. E. Boeke, Zeitschr. Kryst. Min., vol. 47,1910, p. 273.

*Boeko, in a private communication, suggests that if tho formula of carnallite is doubled, to 

K2Mg2Clc.l2H2O, tachhydrito becomes CaMg2Clc .12H2O. That is, the .salts are analogous, Ca in one 

replacing K2 in the other.
220 DATA OF GEOCHEMISTRY.

With the exception of the rock salt, which forms the great mass 

of the deposits overlying the anhydrite, these chlorides represent the 

concentration of the mother liquors in the carnallite zone. They were 

the most soluble compounds potentially existing in sea water, and, 

with the sulphato-chloride, kainite, were among the last substances 

to crystallize. Halite and douglasite were distinctly primary 

deposits; carnallite was generally, and sylvite occasionally, primary; 

tachhydrite and bischofite were secondary products. Kainite was 

sometimes one and sometimes the other. The "Hartsalz/ 7 according 

to Van't Hoff and Meyerhoffer,1 is a secondary product formed by the 

action of solutions upon a mixture of carnallite, kieserite, and sodium 

chloride, which was preceded by the splitting up of kainite into 

sylvite and kieserite. The kainite, in its most conspicuous development, lies between the carnallite and the "Hartsalz." From the carnallite itself, sylvite and bischofite may be derived, or it may be 

formed by the direct union of these species, which are its two components. According to C. Przibylla,2 when sylvite and bischofite 

combine to form carnallite, there is an increase of 4.95 per cent in 

volume. Possibly, therefore, the formation of carnallite at low levels 

is prevented by pressure.

In one essential respect, the foregoing paragraph demands qualification. According to Boeke 3 the existence of douglasite is doubtful. 

Another mineral, rinneite, discovered by him in the "Hartsalz" of 

Saxony and the Harz, has the formula FeCl23KCl.NaCl.4 The substance named douglasite may have been identical with this. ' Boeke, 

moreover, regards the "Hartsalz" as a direct deposition for the 

reason that it is distinctly stratified.

Two other chlorides, not found at Stassfurt, have been described 

from similar deposits in adjacent regions. Koenenite, discovered by 

F. Binne 5 in salts from Volpriehausen in the Sollingerwald, has the 

complex formula Al2Os.3Mg0.2MgCl2 .6 or 8H20. Baeumlerite, from 

the Leine valley in Hannover, according to 0. Renner 8 is KCl.CaCl2 .

With the carnallite and its overlying potassium salts, the borates 

generally occur. They are boracite, sulphoborite, pinnoite, ascharite, and heintzite; one other, hydroboracite, is found earlier in the 

series, near the lower limit of the polyhalite zone. These species are 

relatively rare, except the boracite, and it is not necessary to consider

1 Sitzungsb. Akad. Berlin, 1902, p. 1106. See also J. H. Van't Hoff, F. B. Kenrick, and H. M. Dawson, Zcitschr. physikal. Chemie, vol. 39,1902, p. 27, oiathe conditions of formation of tachhydrite.

2 Centralbl. Min., Geol. u. Pal., 1904, p. 234.

8 Neues Jahrb., 1909, Bd. 2, p. 19. Tor the-first description of rinneite, see Centralbl. Min., Geol. u. Pal., 

1909, p. 72. On the synthesis of rinneite see Boeke, Sitzungsb. Akad. Berlin, vol. 24,1910, p. 632. Boeke 

has described the iron compounds of the Stassfert beds in Neues Jahrb., 1911, Bd. 1, p. 48, and Centralbl. 

Min., Geol. u. Pal., 1911, p. 48. See also F. Kinne and R. Kolb, idem, p. 357.

* 0. Schneider (Centralbl. Min., Geol. u. Pal., 1909, p. 503) regards theNaCl of rinneite as a mechanical 

admixture.

» Centralbl. Min., Geol. u. Pal., 1902, p. 493.

»Idem, 1912, p. 106.
SALINE RESIDUES. 221

them any further at this point, for their occurrence tells us little 

about the main phenomena of saline concentration.

We must not suppose, for an instant, that these zones of deposition 

are regularly and completely separated, nor even that they represent 

in any close degree the products observed in the artificial evaporation 

of sea water or brine. In the latter case a moderate quantity of water 

is concentrated by itself; at Stassfurt more water was continually 

added from the ocean. On the one hand calcium sulphate is deposited 

almost wholly at one time; on the other new quantities were precipitated so long as the evaporating bay retained its connection with the 

sea. In the salt pan gypsum forms a bottom layer before salt begins 

to separate out; at Stassfurt anhydrite is found in greater or less 

amount through all the zones, and so also is the sodium chloride. 

When a shallow lake or isolated lagoon evaporates, the artificial 

process is closely paralleled, but a concentration with continuous 

replenishment lasting for thousands of years is a very different thing. 

The principles are unchanged, the broad outlines remain the same, 

but the details of the process are greatly modified.

E. Erdmann 1 regards the Stassfurt salts as having been formed 

from a shallow portion of the Permian ocean, which covered a great 

part of North Germany and became isolated from the ,main sea, 

The evaporation products collected in depressions of the land and 

were reinforced by calcium sulphate from fresh-water affluents. 

Sea water alone contains too little calcium to account for the anhydrite present in the beds. Walther's views are similar. Both reject 

the "bar "theory.

We are now in a position to trace more distinctly the phenomena 

which attended the formation of the beds at Stassfurt.2 For a long 

time only gypsum was deposited; but later, as the concentration of 

the bay increased, salt also was laid down, and by its action the gypsum was converted into anhydrite.3 From this point onward, for a 

considerable period, the calcium sulphate derived from the influx of 

sea water above fell through a deep layer of concentrated brine and 

was deposited directly as anhydrite, in alternating layers with the 

salt.4 When, however, so much salt had been precipitated that the 

supernatant solutions had become bitterns rich in magnesium salts, 

the calcium sulphate united with these salts, and polyhalite was 

formed. The polyhalite region at Stassfurt is essentially a bed of

1 Zeitschr. angcw. Chcmie, vol. 21,1908, p. 1685. A short additional communication by Erdmann is in tho 

same journal, vol. 22,1909, p. 238.

2 Cf. G. Lunge, Thorpe's dictionary of applied chemistry, vol. 3,1893, p. 208.

3 According to J. H. Van't Hofl and F. Weigert, Sitzungsb. K. Akad. Wiss. Berlin, 1901, p. 1140, anhydrite forms from gypsum in sodium chloride solutions at 30°. In sea water the transformation takes place 

at 25°.

< Cf. J. H. Van't HofE and P. Farup, Sitzungsb. Akad. Berlin, 1903, p. 1000. H. Vater (idem, 1900, p. 270) 

discusses marine anhydrite, and gives many references to literature. At ordinary temperatures, according 

to Vater, calcium sulphate crystallizes from a saturated solution of salt in the form of gypsum.
222 DATA OF GEOCHEMISTRY.

rock salt, containing, with other impurities, from 6 to 7 per cent of 

the new mineral. Possibly syngenite, CaK2 (S04) 2 .H20, a species 

which occurs in a similar deposit at Kalusz in Galicia but which does 

not seem to be recorded from Stassfurt, was first produced. Syngenite may be prepared artificially by the direct action of potassium 

sulphate upon gypsum, and it is converted by strong solutions of magnesium chloride and sulphate into polyhalite.1 The occurrence of 

syngenite at Kalusz is below the potassium salts, in rock salt containing anhydrite. It is therefore the equivalent in position of polyhalite.2 

As the concentration of the magnesian mother liquors increased, 

kieserite was produced, the dehydrating action of magnesium chloride preventing the formation of epsomite. H. Precht and B. Wittjen s have shown that when magnesium chloride and sulphate are 

dissolved together and the solution then evaporated upon th& water 

bath, kieserite separates out. Thus the kieserite zone was formed, 

which contains, on an average, 65 per cent of rock salt, 17 of kieserite, 

13 of carnallite, 3 of bischofite, and 2 of anhydrite. At this point 

polyhalite disappears. The last step in the concentration was the 

formation of carnallite, with its associated minerals, from the chlorides which had hitherto remained in solution. The average composition of this zone is 55 per cent of carnallite, 25 of rock, salt, 16 

of kieserite, and 4 of various other minerals. The kainite layers 

above the carnallite were probably formed by the action of percolating waters upon the latter mineral, in presence of some kieserite. 

Finally, a protecting layer of mud or clay was laid down over the 

mass of salts, preventing in great measure, but perhaps not entirely, 

their subsequent re-solution. Into all of the foregoing reactions one 

element entered which counts for little in their imitation on a small 

scale namely, the element of time. The prolonged action of the 

mother liquors, during thousands of years, upon the earlier deposits, 

must have been much more thorough than their effect during an 

experiment in the laboratory. In the latter case the solid deposits are 

usually removed from time to time, so that the procedure does not 

accurately repeat the operations .of nature. These considerations 

should especially be taken into account in studying the transformation of gypsum into anhydrite, or the reverse reaction which has 

often been observed.'1 Beds of anhydrite may take up water and be

i E. E. Basch, Sitzungsb. K. Akad.' Wiss. Berlin, 1900, p. 1084.

a A. Aigner (Oestcrr. Zeitschr. Berg- u. Hiittcnw., 1901, p. 686) has described the Austrian polyhalite. 

For analyses of kainite, carnallite, etc., from Kaluszand Aussee, see C. von John, Jahrb. K.-k.geol. Reichsanstalt, vol. 42, 1892, p. 341. On mirabilite from Kalusz, sec E. Zaloziecki, Monatsh. Chcmie, vcl. 13, 

1892, p. 504. Two papers on the potash salts of Austria and the Tyrol by R. Gorgey arc in Min. pet. Mitt., 

vol. 28, 1909, p. 334, and vol. 29, 1910, p. 148. Gorgey (idem, vol. 31,. 1912, p. 339) has also described ttio 

potashsalts of Wittelsheim, Alsace. Another paper on these Alsatian salts,by M. Rfizsa, is In Zeitschr. 

anorg. u. allgcm. Chemic, vol. 93,1915, p. 137. On Spanish deposits see C. Rubio and A. Marin, Bol.'Inst. 

geol. Espafia, vol. 34,1914, p. 173.

a Ber. Dcutsch. chem. Gcscll., vol. 14,1881, p. 2131.

4 Cf. F. Hammerschmidt, Min. pet. Mitt., voL 5,1882-83, p. 272; and J. F. McCaleb, Am. Chem. Jour., 

vol. 11,1889, p. 34.
- SALINE RESIDUES. 223

reconverted into gypsum through considerable depths, as at Bex in 

Switzerland, where the alteration has reached a thickness of 60 to 

100 feet. Time is an important factor in all such transformations, 

especially when one of the reacting bodies happens to be a solid of 

relatively low solubility.

The temperature conditions which governed the deposition of the 

Stassfurt salts are briefly summed up by Van't Hoff 1 as follows:

1. Glauberite, formed above 10°.

2. Langbeijiite, formed above 37°.

3. Loewite, formed above 43°.

4. Vanthoffite, formed above 4G°.

5. Loewite with glaserite, formed above 57°. 

C. Loewite with vanthoffite, formed above 60P. 

7. Kieserite with sylvite, formed above 72°.

This scale of temperatures is designated as a "geological thermometer, ;; and gives us something like a definite idea of past conditions in the Stassfurt beds.2

OTHER SALT BEDS.

The Stassfurt deposits, as has already been indicated, are altogether exceptional in their completeness. Rock salt is generally 

found in much thinner deposits, and as a rule it is unaccompanied 

by potassium or magnesium salts in any notable quantities. Gypsum 

or anhydrite, however, is commonly present, either under the salt 

or in its near neighborhood. Where gypsum is absent we may infer, 

with a fair degree of probability, that the salt is of secondary origin 

and not derived directly from sea water, or that it came from the 

evaporation of a salt lake which contained either no calcium or no 

sulphates. Gypsum, of course, can not form unless its constituents 

are at hand. Furthermore, gypsum may be produced otherwise 

than from the concentration of sea water, and it may exist as a 

remainder where the more soluble salts have been washed away. It 

can occur independently of or concomitant with the presence of rock 

salt, and each locality must be considered on its individual merits. 

On some small coral islands in the Pacific gypsum is found as a residue from the evaporation of lagoons, in beds which may reach 2 feet 

in thickness.3 Here the origin from sea water is evident. On the 

other hand, waters containing little or no salt often deposit gypsum. 

I. C. Russell,4 for instance, has described such a deposit at Fillmore, 

Utah, which covers an area of 12 square miles and has been opened 

to a depth of 6 feet without reaching bottom. Gypsum is also com1 Zoitschr. Elektrochemio, vol. 11,1905, p. 709.

2 The scientific investigation of the Stassfurt salts is being continued by a society formed for that purpose: For a list of the publications of its members see Van't Hoff, Sitzungsb. K. Akad. Wiss. Berlin, No, 

39,1910, p. 772.

s J. D. Dana, Manual of geology, 4th ed., p. 120. On the Cis-Indus (India) salt beds, which contain 

potassium salts, see W. A. K. Christie, Rec. Geol. Survey India, voLM, 1914, p. 241.

4Mon. U. S. Geol. Survey, vol. 11,18S5, p. 84. The deposition of gypsum by Lake Chichen-Kanab, 

Yucatan, was mentioned in Chapter V.
224 DATA OF GEOCHEMISTRY.

mon as an efflorescence or incrustation in caves/ and it can be pro- v. 

duced by the alteration of other rocks. The oxidation of pyrites in 

limestone may form gypsum; or, as was shown in the preceding chap- ~* 

ter, it can originate from double decomposition between other metallic 

sulphates and calcium carbonate. L. W. Jowa, 2 for example, pre- '' 

pared selenite in measurable crystals by the action of a solution of 

ferrous sulphate on chalk. /

In the Salina formation of New York gypsum occurs above the 

salt, and its presence is attributed by Dana 3 to the alteration of the \~ 

overlying " Wateiiime" beds. In this region the salt occurs in layers \ 

interstratified with shales, a series of shallow-water deposits having 

been successively covered by bodies of mud or clay.4 At Goderich, 

Canada, a similar but not identical alternation has been observed.5 

Here a boring 1,517 feet deep revealed dolomite and anhydrite, and 

above that were six beds of salt alternating with similar materials. r 

The uppermost salt was struck at 1,028 feet, and at 876 feet dolomite, with seams of gypsum, was found. The anhydrite at bottom 

was probably normal; but what the upper gypsum signifies is not 

clearly shown. It may be the beginning of an unfinished concentra- / 

tion, or else quite independent of the salt below. Throughout the 

region of salt more or less anhydrite was found, but potassium com- * 

pounds were either absent or present only in traces. Neither in 

New York nor in the Goderich deposits were the mother liquors per^ 

mitted to crystallize. 0 "

The great salt deposits of Louisiana and Texas are associated not 

only with gypsum but also with sulphur, sulphurous gases, and 

petroleum. At first, before the petroleum was discovered, the salt u 

beds were regarded as of marine origin.7 Later, R. T. Hill 8 inter- .^. 

pre ted them as derived from hot saline waters rising from great 

depths, and a similar view was put forth by L. Hager. 9 E. Coste, 10 

a strenuous advocate of the volcanic origin of petroleum, has argued 

that the salt is its obvious companion, but his argument is hardly 

conclusive. Sodium chloride is known as a volcanic sublimate, and 

some authors have argued that the salt of the ocean is volcanic also; 

but extreme views of this sort are rarely sound. The most that can 

be said is that the origin of the Louisiana-Texas salt has not yet (

J See G. P. Merrill, Proc. U. S. Nat. Mus., vol. 17,1905, p. 77.

2 Annales Soc. g<5ol. Belgique, vol. 23,1895-96, p. cxxviii.

3 Manual of geology, 4th ed., p. 554.

4 See sections given in Bull. New York State Mus. No. 11,1893.

B T. S. Hunt, Gool. Survey Canada, Eept. Progress, 1876-77, p. 221. ,

» The solubility of calcium sulphate, gypsum, anhydrite, etc., in water and various solutions has been 

elaborately studied. See an excellent summary by F. K. Cameron and J. M. Bell, in Bull. No. 33, Bur. 

Soils,U. S. Dept. Agr., 1906.

' See, for example, G. I. Adams, Bull. U. S. Geol. Survey No. 184,1901, p. 49. Also doubts raised by 

C. W. Hayes and W. Kennedy in Bull. U. S. Geol. Survey No. 212,1903, p. 144.

8 Jour. Franklin Inst., vol. 154,1902, p. 273.

9 Eng. and Min. Jour., vol. 78,1904, pp. 137,180. j_

10 Jour. Canadian Min. Inst., vol. 6,1903, p. 73.
SALINE RESIDUES. 225

received its final interpretation. 1 It would be most unwise to claim 

that all salt deposits are formed in the same way.. Some are certainly 

marine, some are residues from salt lakes, others may represent concentrations from magmatic waters. The subject, however, is so large 

that a more extended discussion of it is impracticable here.

ANALYSES OF SALT.

Neither salt nor gypsum is found in nature in a state of absolute 

purity, although that condition is sometimes very nearly approximated. Being deposited from solutions containing other substances, 

some of the latter are always carried down and reveal their presence 

on analysis. Analyses of rock salt are exceedingly numerous, and 

only a moderate number, enough to show the range of variation in 

the mineral, need be cited here. 2

Analyses of rock salt.

A. Salt from Goderich, Canada. Analysis by Gould, for T. Stcrry Hunt, Geol. Survey Canada, Rept. 

Progress, 1876-77, p. 233.

B. Salt from Kingman, Kansas. Analysis by E. H. S. Bailey and E. C. Case, Kansas Univ. Geol. Survey, vol. 7,1902, p. 73. Ten other analyses of rock salt are given, mostly purer than this.

C. Saline incrustation, Tuthill Marsh, Kansas. Idem, p. 70. Analysis made in the University of Kansas 

laboratory, but analyst not named.

D. Salt from Petit Anse, Louisiana. Analysis by F. W. Taylor, Mineral Resources U. S. for 1883, U. S. 

Geol. Survey, p. 564.

E. Salt from Leoncito, La Rioja Province, Argentina. Analysis by L. Harperath, Bol. Acad. nac. cien. 

C<3rdoba, Argentina, vol. 10, 1890, p. 427. Remarkable for its high proportion of potassium salts. Harperath gives nineteen analyses of Argentine salt, some of them representing great purity, but several approaching this one.

F. Salt stalactite from a disused working at Redhaugh colliery, Gateshead, England. Analysis by 

W. H. Dunn, published by P. P. Bedson, Jour. Soc. Chem. Ind., vol. 8, 1889, p. 98. This analysis, in 

the original, is stated in the form of radicles. It is recalculated here to salts for uniformity with the others.

G. Salt from bed deposited by the Katwee Lake, north of the Albert Edward Nyanza, central Africa. 

Analysis by H. S. Wellcome; abstract in Jour. Soc. Chem. Ind., vol. 9, 1890, p. 734. An analysis of the 

lake water by A. Pappe and H. D. Richmond is also given in this journal. See ante, p. 109.

NaCL... .............

KC1.................

CaCL. ...............

MgCl.................

Na2S04 ..............

KaS04 ........... .....

CaS04 . ..............

MgS04 .. .............

Na2C03 ... ...........

Ala03 . -- - -

FQA03 ... ..............

SiOa ........ ..........

H,0. ................

A

99. 687

.032

.095

.090

..017

.079

100. 000

B

97.51

.10

.57

1.51

.11

.20

100. 00

C

71.82

21.98

.99

1.29

3.56

}

1 q .18

.23

100. 00

D

98. 731

.013

1.192

.010

.024

.030

100. 000

E

81. 491

17. 483

.048

.978

100. 000

F

99.00

.52

.15

.28

99.95

G

82.71

5.32

8.43

2.46

.15

.82

99.89

i In Bull. Geol. Survey Louisiana No. 7, 1908, G. D. Harris describes the salt deposits and discusses 

their origin. He also gives a very complete summary of information on the salt deposits of the world. 

The fullest treatise on salt, covering the globe, is by J. 0. von Buschman, Das Salz, 2 vols., Leipzig, 1906 

and 1909.

a See Thorpe's Dictionary of applied chemistry, vol. 4, p. 430, for additional data. Also Geol. Survey 

Michigan, vol. 3, appendix B, and vol. 5, pt. 2, for Michigan salt and brines; Bull. New York State Mus. 

No. 11, for New York examples.; Prel. Rept. Geol. Louisiana, 1899, for material from that State; and C. I. 

Istrati, Bull. Soc. chim., 3d ser., vol. 2, 1889, p. 4, for analyses of Rumanian salt. Some Rumanian 

samples contain as high as 99.9 per cent of sodium chloride.

113750° 19 Bull. 695 15
226 DATA OF GEOCHEMISTRY.

Ill addition to the impurities -shown in the analyses, rock salt frequently contains gaseous inclusions. These have been often examined, recently by N. Costachescu,1 who finds some of them to consist 

mainly of. nitrogen, and others mainly of methane. Other hydrocarbons and carbon dioxide are also found. Rock salt is not uncommonly colored, especially blue. This coloration has been attributed 

to organic matter, and recently, by H. Siedentopf,2 to the presence 

of minute particles of metallic sodium. This very remarkable conclusion would seem to require confirmation.

ANALYSES OF GYPSUM.

For gypsum the following analyses, all made in the laboratory of 

the United States Geological Survey, are sufficient to show its usual 

character: 3

Analyses of gypsum.

A. From Hillsboro, New Brunswick. Analysis by George Steigcr. 

B. From Alabaster, Michigan. Analysis by Stciger. 

C. From east of Cascade, Black Hills, South Dakota. Analysis by Steiger.

D, E. From Nephi, Utah. Analyses by E. T. Alien. This material evidently contains admixed anhydrite.

so3 .... ....... ........................

C02 ..................................

Cl............ ........................

SiOo...................................

Al O

Tfp O

CaO.. ........... ......................

MgO.................................

Na20.................... ..............

K20..................................

H,0. .................................

A

40.18

Trace.

\ au

32.37

Trace.

} , 10

20.94

.10

99.79

B

46.18

.03

1

} .08

32.33

.05 } - u

20.96

.05

99.82

C

45.45

.85

.10

.12

32.44

.33

20.80

100. 09

D

48.14

.65

..Trace.

35.29

Trace.

15.88

99.96

E

39.53

7.73

.04

} .14

38. 46

.24

.07

19

12.69

.45

99. 54

1 Ann. Univ. Jassy, vol. 4,1906, p. 3. The author gives a good summary of earlier investigations.

2 Physikal. Zeitschr., vol. 6, 1905, p. 855. See also L. Wohler and H. Kasarnowski, Zeitschr. anorg. 

Chemic, vol. 47,1905, p. 853, and F. Cornu, Centralbl. Min., .Geol. u- Pal., 1907, p. 166, and Ncucs Jahrb., 

1908, p. 32. G. Spezia (Centralbl. Min., Geol. u. Pal., 1909, p. 398) cites experimental evidence adverse to 

Siedentopf's views. E. Erdmann (Ber. Dcutsch. chcm. Gesell., vol. 43, p. 777) ascribes the blue, of salt to 

radioactivity, which is known to effect color changes in minerals.

3 For other data relative to the composition and origin of gypsum, see G. P. Grimslcy and E. H. S. Bailey, 

Univ. Geol. Survey Kansas, vol. 5,1899. Also E. C. Eckcl, Bull. U. S. Geol. Survey No. 213,1903, p. 407; 

G. P. Grimsley, Geol. Survey Michigan, vol. 9, pt. 2,1903-4, and Am. Geologist, vol. 34,1904, p. 378; F. A. 

Wilder, Jour. Geology, vol. 11, 1903, p. 723; A. L. Parsons, Twenty-third Eept. State Geologist, New 

York State Mus., 1903; and G. 1. Adams and others, on gypsum deposits of the United States, Bull. U. S. 

Geol. Survey No. 223, 1904. A recent report on the gypsum of New York is by D. H. Ncvdand and H. 

Leighton, Bull. New York State Mus. No. 143,1910. On the genetic relations of gypsum and anhydrite, 

'see R. C. Wallace, Geol. Mag., 1914, p. 276.
SALINE RESIDUES. 227

BITTEBNS.

In what has been said so far, we have considered almost exclusively 

the concentration of sea water; but other waters form other deposits 

and yield different bitterns. Analyses of bitterns are not often 

reported, and only a few examples can be given here.1 These analyses 

are recalculated to ionic form, and give the percentage composition 

of the anhydrous saline matter.

Analyses of bitterns.

A. Bittorn from Leslie Salt Refining Works, San Mateo, California. Analysis by R. F. Gardner. From 

sea water.

B. Bittern of maximum concentration, from the brines of Syracuse, New York. Analysis by C. A. Goessmann, Am. Jour. Sci., 2d ser., vol. 44,18G7, p. 80.

C. Bittern from Pomeroy, Ohio. Analysis by A. R. Herzand R. F. Gardner. 

. D. Bittern from Hartford, West Virginia. Merz and Gardner, analysts.

E. Bittern from Saginaw, Michigan. Gardner analyst. Analyses A, C,D,E recalculated to percentages 

from the figures given by J. W. Turrentino in U. S. Dept. Agric., Bur. Soils Bull. No. 04,1913. Selected 

from a number of analyses reported on pp. C1-C6.

F. Bittern from the saline of Modellin, Antioquia, Colombia. Analysis by J. B. Boussingault, Annalos 

chim. phys., 5th ser., vol. 2,1874, p. 102, Known locally as "oil of salt."

G. Bittern from salt works of Allendorf-an-Werra, Germany. Analysis by Reichardt, abstract i:* Jour. 

Chem. Soc., vol. 42,1882, p. 24.

Cl....... ............

Br....................

I....................

S04 .... ..............

Na......... ..........

K......... ..........

Li....................

NH4 ............ ......

Ca....................

Mg. .................

Si02 ..................

Organic..............

Salinity, per cent.... .

A

56.33

.94

9.28

22.23

2.58

.38

7.56

100. 00 

31.82

B

G3. 93

1.16

Trace.

.06

10.24

5.27

11.26

8.08

100. 00 

33. 567

C

G2. 42

2.07

.93

.46

.57

26.00

7.55

100. 00

55.88

D

62. 70

2.21

.69

.04

.53

25.97

7.86

100. 00 

55.23

E

GO. 18

1.33

Trace.

25.27

.49

9.82

2.91

100. 00 

32.97

F

44, 99

1.02

.03

14.07

25.97

11.18

Trace.

.09

.28

2.37

100. 00 

33. 478

G

55.56

.22

15.08

10.62

6. 40

.01

.07

8. 81

.02

321

100. 00 

29. 149

Although these bitterns vary widely in composition, in consequence 

of the differences between the original brines, they are nearly all noteworthy as showing the concentration in them of bromine. The Michigan brines are important commercial sources of bromine, and so, too, 

are those of the Kanawha Valley in West Virginia. A. L. Baker 2 

reports that 20 to 30 gallons of Kanawha bittern will yield 1 pound 

of bromine, and he has also shown that they contain iodine in very 

appreciable amounts, from 38.4 to 59.2 milligrams per liter. The 

richness of the Dead Sea in bromine has already been pointed out. 

Bitterns of this class deserve a more careful study than they seem' 

to have yet received.

i In addition to Usiglio's analyses cited on p. 214, ante. 2 Chctn. News, vol. 44, p. 207, 1881.
228. DATA OF GEOCHEMISTRY. 

^ SODIUM SULPHATE.

In the evaporation of ocean water the sulphates which form are 

first the calcium compound and then the magnesium .salt, or else 

double sulphates of magnesium, with either calcium or sodium. 

Anhydrite, then polyhalite, and then kieserite, follow one another in 

regular succession. In many saline lakes, however, calcium and magnesium are deficient in quantity, while sodium sulphate is present in 

relatively large amounts. In such lakes sodium sulphate is deposited 

in considerable quantities, generally preceding the deposition of salt, 

and its precipitation is determined or affected by the season of the 

year. Sodium sulphate is much more soluble in warm than in cold 

water, but the similar variation for salt is comparatively small; so 

that the mere change of temperature between summer and whiter 

may cause mirabilite to separate out, or to redissolve again. An 

instance of this kind, in the Karaboghaz, has already been noticed, 

and the Great Salt Lake 1 not only deposits sodium sulphate during 

winter, but even casts it up in heaps upon shore. The salt thus 

formed is the decahydrate, mirabilite, Na2 .SO4 .10H20; while from 

warm solutions, especially from concentrated brines, the anhydrous 

sulphate thenardite may be deposited. In warm and dry air mirabilite effloresces, loses its water, and is transformed into thenardite, 

which is a well-known and common mineral. On the surface of 

Lacu Sarat, in Rumania,2 large crystals of mirabilite form during 

winter, to redissolve, at least in part, when the weather becomes 

warm, and many other sulphate or sulphate-chloride lakes exhibit 

similar phenomena. The Siberian lakes, studied by F. Ludwig,3 

deposit mainly sulphates; sodium sulphate in Lakes Altai, Beisk, 

Domoshakovo, and Kisil-Kul, while in the Schunett Lake a quantity 

of magnesium sulphate is also formed. Ludwig gives analyses of 

these precipitates, but the three in the subjoined table are enough 

to cite here. The analyses are carried by Ludwig to four decimal 

places, but I have rounded them off to two. He also gives the Na 

and Cl of the sodium chloride separately, and the insoluble residue 

he divides into organic and inorganic. The consolidation of the data 

as tabulated below is for the sake of simplicity. Their subdivision 

does not help to illustrate the phenomena now under discussion.

i G. K. Gilbert, Mon. U. S. Geol. Survey, vol. 1,1890, p. 253.

»L. Mrazec and W. Teisseyre, Apercu g6ologique sur les formations saliferes et les gisements do sel en 

Roumanie, 1902. This memoir contains a bibliography relative to Rumanian salt. 

»Zeitschr. prakt. Geologic, vol. 11,1903, p. 401. Cf. ante, p. 167.
SALINE RESIDUES. 

Analyses of saline deposits.in two Siberian lakes.

229

A. Deposit on bottom of Lake Altai. 

B. Deposit on shore of Lake Altai. 

C. Deposit on shore of Schunett Lake.

coa ............ .......................................

so,. ...................................................

Na20. ..................................................

K20.. .................................................

NaCl ...................................................

CaO. ...................................................

MgO ..................................................

A i r\

FeA-. ...............................................

SiOa ....................................................

Insoluble residue. .........................................

 A '

0.12

54.00

41.64

.29

.22

.11

.11

3.46

99.95

B

0.03

55.67

43.21

"13

.01

} .0!

.91

99.97

C

0.63

M 4^

25. 96"

1 Q3

02

.07

10.22

.07

.01

.07

5.70

100. 03

These lakes, Altai and Schunett, are sulphate-chloride waters, but 

the first effect of their concentration is to bring about a partial separation of then* salts. The same effect is perhaps even better exemplified by Sevier Lake, in Utah, which is at times entirely dry, forming a thin saline layer that in moister seasons partly redissolves.1 

The deposits from this lake have been analyzed, those from the 

margin by 0. D. Alien, those from the center by S. A. Lattimore, and 

their average composition, as cited by Gilbert, is given below:

Average composition of deposits from Sevier Lake, Utah.

Na2S04 . ........................................................

Na2C03 . .......................................................

NaCl. .........................................................

CaS04 . ........................................................

MgS04 .... .......................................................

K2S04 .........................................................

H

f\

Margin.

14 3

75.8

5.5

.7

3.6

.1

100.0

Center.

84 f\

.4

7.0

Trace.

Trace.

8.0

Trace.

100.0

Here the sodium sulphate tends to accumulate at the center of the 

lake, whereas the later deposits, which are covered by a crust of 

sodium chloride, are formed in larger relative proportion around 

the margin. 

i G. K. Gilbert, Mon. U. S. Geol. Survey, vol. 1, 1890, pp. 224-227. See p. 154, ante, for the composition 

of the brine.
230 DATA OF GEOCHEMISTRY.

Fractional crystallization, however, is only a part of the process 

by which the saline constituents of a water may be separated. Salt 

and alkaline lakes are peculiarly characteristic of desert regions, 

and the smaller depressions may be alternately dry and filled with 

water. Suppose, now, following a suggestion of J. Walther,1 that 

such a lake, concentrated to a bed of salt covered by a thin sheet of 

bittern, is overwhelmed by desert sands, so that a permanent saline 

deposit, protected from further change, is formed. The bittern will 

be absorbed by the sandy covering, its salts will rise by capillary 

attraction to the surface, and the efflorescence thus produced will be 

scattered in dust by the winds. On the steppes of the lower Volga, 

according to Walther, there are numerous remainders of salt lakes, 

which have been thus covered, and where, beneath the sand, solid 

salt of great purity is found. The mother liquors have vanished, 

and their saline constituents have been scattered far and wide.

MISCELLANEOUS DESERT SALTS.

Wherever deserts exist, there these saline residues are common. 

They are peculiarly abundant in the western part of the United 

States, especially in the Bonneville and Lahontan basins and over 

the so-called alkali plains, and they exhibit a great variety of composition. Chlorides, sulphates, carbonates, and berates occur, separately or together, and many analyses of these products have been 

recorded. To the sulphate-chloride class the subjoined analyses belong, the other saline deposits being left for separate consideration

later.2

Analyses of saline deposits from sulphato-chloride loaters.

A. Salt, Osobb Valley, Nevada. Analysis by R. W. Woodward, Rept. U. S. Geol. Expl. 40tli Par., 

vol. 2, 1S77, p. 707.

B. Saline efflorescence on desert, south of Hot Springs station, Nevada. Analysis by 0. D. Alien, idem, 

p. 773.

C. Incrustation from Quinns River crossing, Black Rock Desert, Nevada. Analysis by 0.1?. Alien, 

idem, p. 791.

D. Salt from Salt Lake, 7 miles east of the Zandia Mountains, New Mexico. Analysis by O. Loew, Rept. 

U. S. Geol. Surveys W. 100th Mer., vol. 3,1875, p. 627. -

E. Efflorescence.from alkaliflat, near Buffalo Spring, Nevada. Analysis by 0. D. Alien, op. eit., p. 731.

F. Efflorescence from Santa Catalina, Arizona. Analysis by 0. Loew, op. cit., p. 628.

G. Salt from shore of lake near Percy, Nevada. Analysis by R. W. Woodward, Rept. U. S. Geol. Expl. 

40th Par., vol. 2,1S77, p. 148.

H. Efflorescence on loess, near Cordoba, Argentina. Analysis by Doering, cited by A. W. Stclzner, 

Beitrage zur Geologic und Palacontologie der Argentinischen Republik, 1885. A number of salts, etc., are 

described on pages 295-309. This one is remarkably rich in potassium.

1 Das G esetz der Wiistenbildung, Berlin, 1900, p. 149. Chapter 13 is devoted to the subject of desert salts. 

See also T. H. Holland (Proc. Liverpool G eol. Soc., vol. 11, p. 227,1912) on the origin of desert salts.

2 A number of analyses of similar products from Argentina are given by F. Schickendantz, Revista del 

Museo de la Plata, vol. 7, 1895, p. 1. See also G. J. Young, Bull. U. S. Dept. Agric. No. 61,1914, on the 

salines of the Great Basin, and several papers by H. S. Gale in Bull. U. S. Geol. Survey No. 640-N, 1913.
SALINE RESIDUES, 231

Analyses of saline deposits-from sulphat-o-cldoridc waters Continued.

Nad. ...............

Na2S04 . ..............

Na2C03 ..............

K,S04 ...... .........

MgCU...............

MgSd4 ..............

CaSO........ .........

H20..................

Insoluble residue. ....

A

96. 49

1.91

.96

.52

.12

100. 00

B

95.67

1.63.

.73

1.97

100. 00

c

85.27

1.75

2.59

8.57

1.82

100. 00:

D

82.57

6.89

5.88

Trace.

4.66

100: '00

E

70. 81

26. 38

1.94

99. 13

V

5.93

94.04

99. 97

G

0.74

46.27

48. 28

4.45

99.74

H

10.81

53.14

32.34

3.71

100. 00

These analyses, taken in connection with those of salt given on page 

225, show the same order of variation as is found in the parent waters 

themselves. Chlorides form one end of the series, sulphates the 

other; and every gradation may exist between the two. Even different parts of the same deposit may show evidence of such a gradation, as in Sevier Lake, where separation of the salts had gone on to 

a greater or less extent; but partial re-solution in time of high water 

can reverse the process and bring about a new distribution of the 

soluble substances.

ALKALINE CARBONATES.

From alkaline lakes alkaline carbonates are deposited, mingled with 

chlorides and sulphates in varying proportions. In Hungary, Egypt, 

Armenia, and Venezuela such deposits are found, and they are peculiarly common in the Lahontan basin of Nevada, and in southern 

California. In Nevada they of ten form "playas," or "playa lakes" 1 

beds which are dry in summer and flooded to the depth of a few inches 

during the wet season. A. number of. these . alkaline incrustations 

were analyzed by the chemists of the Fortieth Parallel Survey, with 

the results shown in analyses A to F of the subjoined table.2 With 

these may be included two analyses of the soluble parts of incrustations, made by T. M. Chatard in the laboratory of the United States 

Geological Survey.

' i Sco I. C. Russell, Mon. U. S. Gcol. Survey, vol. 11, 1885, p. 81.

2 The analyses are here cited as recalculated by T. M. Chatard, Bull. U. B. Gcol. Survey No. CO, 1800, 

pp. 55, 50. The original statements do not adequately discriminate bctv/ecn carbonates and bicarbonatcs.
232 DATA OF GEOCHEMISTRY.

Analyses of incrustations deposited by alkaline lakes.

A. From western arm of Black Rock Desert, near the so-called "Hardin City," Nevada. Analysis by 

O. D. Alien, vol. 2,1877, p. 792.

B. From Ruby Valley, Nevada. Analysis by R. W. Woodward, vol. 1,1878, p. 503. 

C. From valley of Deep Creek, Utah. Analysis by Woodward, vol. 2, p. 474. 

D. From Antelope Valley, Nevada. Analysis by Woodward, vol. 2, p. 541.

E. From a point near Pekostation, on Humboldt River, Nevada. Analysis by Woodward, vol. 2, p. 594. 

F. From Brown's station, Humboldt Lake, Nevada. Analysis by Woodward, vol. 2, p. 744. 

Q. From surface of playa, north arm of Old Walker Lake, Nevada. Soluble portion, 29.78 per cent. 

H. Five miles west of Black Rock, Nevada. Soluble portion, 23.10 per cent.

Na,CO. .............

NafiC03 . ...........

Na2S04 .............

NaCl................

NaaB407 . ...........

K2S04 ........ .......

KOI. ...............

Si03 .. ................

A

52. 10

27.55

18.47

98.12

B

58.69

8.09

28.32

2.11

2.79

100. 00

c

25.12

14.76

17.43

38.01

4.68

100. 00

D

25.95

14.35

33.31

24.51

1.88

100. 00

E

48.99

36.01

4.42

7.24

3.34

100. 00

F

7.02

11.13

49.67

20.88

11.30

100. 00

G

72.69

17.49

2.53

4.15

1.18

1.96

100. 00

H

9.06

27.05

59.32

1.00

1.30

2.18

100. 00

The following table, contains analyses, reported by E. W. Hilgard,1 

of the soluble part of "alkali" incrustations from California. They 

exhibit remarkable peculiarities of composition, especially in their 

contents of potassium salts, nitrates, and phosphates.

Analyses of "alkali" incrustations from California.

A. From Visalia, Tulare County.

B. From Westminster, Orange County.

C. From the experiment station, Tulare County. 

D. From the Merced bottoms, Merced County.

Na2C03 .. ......................................

Na2S04 .......................................

NaCl... .......................................

NaNO,... ....................................

NaH2P04 . ....................................

K rn

K,S04 .. .......................................

MiS04 ....... .................................

(NH4 ) 2CO3 . ... . ................................

A

65.72

3.98

8.42

20.23

1.65

100. 00

B

62.22

10.57

6.59

20.62

100. 00

C

32.58

25.28

14.75

19.78

2.25

o qc

1.41

100. 00

D

75.95

4.67

1.46

12.98

4.94

100. 00

Similar deposits are formed-by the two soda lakes at Ragtown, 

Nevada, and these have been worked for commercial purposes. Two 

samples were collected by Arnold Hague in 1868, before working 

began; a third, representing the marketable product, was examined

i Appendix, Kept. Univ. California Exper. Sta., 1890. Other analyses are given in this report?
SALINE RESIDUES. 233

by T. M. Chatard. 1 The analyses are as follows, in the form adopted 

by Chatard:

Analyses of deposits from Soda Lakes, -Ragtown, Nevada.

A. Big Soda Lake. Analysis by O. D. Alien, Kept. U. S. Geol. Expl. 40th Par., vol. 2, 1877, p. 748. 

B. Little Soda Lake. Analysis by Alien, op. cit., p. 759. 

C. Little Soda Lake, market soda. Analysis by Chatard.

Na2CO,. ...............................................

NaHC6,. .............................................

Na2S04 . .............................:................

NaCl..................................................

Si02 ... . ...............................................

Insoluble. ............................................

H20.. ...... ..........................................

A

45. 05

34.66

1.29

1.61

.80

16.19

99.60

B

44.25

34.90

.99

1.10

2.81

15.95

100. 00

c

52.20

25.05

5.10

3.31

97

14. 16

100. 09

These soda lakes also deposit crystals of gaylussite, of the formula 

CaC03 .Na2CO3 .5H20,2 although the analysis of the water 3 reveals 

no calcium. Probably the minute quantities of calcium that enter 

the waters from springs or otherwise are immediately removed in 

this form.

It will be observed, on examining the foregoing analyses, that they 

represent variable mixtures of several salts. The latter, of course, 

have been calculated from the analytical data, and the radicles might 

have been combined somewhat differently, but without any essential 

change in the general results. Several of the analyses are reckoned 

upon the basis of anhydrous material, and are so far incorrect, but 

they show with a fair degree of accuracy the relative proportions of 

the several compounds which were present. The carbonates were 

probably three in number thermonatrite, Na2C03 .H20; natron, 

Na2C03 .10H20; and trona, or urao, Na2C03 .NaHC03 .2H20. Sometimes one and sometimes another of these salts is in excess, but the 

third is the most important, as the elaborate researches of Chatard 4 

have shown. That this is the first salt to be deposited from waters 

of this class his experiments upon Owens Lake water clearly prove.

At Owens Lake, Inyo County, California, the manufacture of 

sodium carbonate has been carried out upon a commercial scale. In 

order to determine the most favorable conditions for the process, 

Chatard subjected a quantity of the water to fractional crystallization and analyzed the salts which were successively deposited. Two

1 Bull. U. S. Geol. Survey No. 60, 1890, p. 52. Chatard cites a number of analyses of foreign urao or 

trona. For analyses of Egyptian urao see O. Popp, Liebig's Annalen, vol. 155,1870, p. 348.

2 See analysis by 0. D. Alien, Kept. U. S. Geol. Expl. 40th Par., vol. 2,1877, p. 749.

3 See p. 157, ante, for analysis of the water.

4 Chatard supposes that the biborate could not exist in so strongly alkaline a solution as the mother 

liquor from which this crop was obtained.
234 DATA OF GEOCHEMISTRY.

concordant series of experiments were-made, together with a less 

complete but corroborative set, on water from Mono Lake. The 

results of the first group were as follows:

Analyses of salts deposited by fractional crystallization from loater of Oivens Lake,

California.

A. The natural water of Owens Lake. Specific gravity 1.062 at 25°. Salinity 77.098 grams per liter. 

This analysis., which represents the composition of the anhydrous residue, was cited 011 page 158 with all 

carbonates as normal; it is here restated in conventional form.

B. First crop of crystals. Water concentrated to one-fifth its original volume. Specific gravity of 

mother liquor 1.312 at 27.9°.

C. Second crop of crystals. Specific gravity of mother liquor 1.312 at 25°.

D. Third crop of crystals. Specific gravity of mother liquor 1.315 at 26.25°.

E. Fourth crop of crystals. Specific gravity of mother liquor 1.327 at 35.75°.

F. Fifth crop of crystals. Specific gravity of mother liquor 1.300 at 13.9°. This crop was obtained by 

chilling the solution, in order to determine the effect of cold.

H20..............- --.-...-

Na,C03 .. ......................

NaHC08 .. ........ ............

Na2SQ4 .. .....................

NaCL. ........................

TSTa "R O

NaBOa .. .......................

KOI.... ........................

(CaMg)C03 .. ..................

(AlFe)203 ... .................

Si02 ............ .............

Insoluble. ... ^. ...............

'A

34.95

7.40

14. 38

38.16

.63

4.07

.08

.05

.28

100.00

B

14.51

43.75

30. 12

3.18

7.44

1.07

.14

.01

. .055

nqo

.078

100. 385

C'

4.33

22.84

10-53

9^ 44

35. 06

1 19

I .09

99.41

D

3.43

18.19

4.06

26.70

AK KQ

1.14

| .06

99. 17

E

2.24

12.51

3

CQ

19.01

60.99

1 91

.61

.05

99.90

F

11. 03.

55.04

4 OQ

K 7A

19.16

&2. 01

9 Q<*

O9

T C

100. 14

6 Natural soda; its occurrence and utilization: Bull. U. S. Geol. Survey No. 60,1890, pp. 27-101. Cf. E. 

Le Neve Foster, Proe. Colorado Sci. Soc., vol. 3,1890, p. 245, lor data concerning Owens Lake. See also 

G. Lunge, Zeitschr. angew. Chemie,. 1893, p. 3. On natural soda in Egypt see A. Lucas, Survey Dept. 

Paper (Egypt) No. 22.1912. A mixture of sodium carbonate and chloride, named' tequesquite, is abundant 

in the region around Lake Texcoco, Mexico. See T. Flores, Anales Inst. Geol. Mexico, 1918, No. 5. Many 

analyses of the salts and related waters are given.

From these analyses we see that the first crop of crystals consists 

largely of trona, Na2C03 .NaHC03.2H20/. with a small excess of the 

normal carbonate, some chloride, and some sulphate. In C, D, and E 

the carbonates diminish, but the normal salt is even more largely in 

excess, while the chlorides increase rapidly. The final, chilled solution deposits chiefly sodium carbonate, with some chloride and less 

sulphate. The order of deposition is trona, sodium sulphate, sodium 

chloride, and finally, if we ignore the minor constituents of the water, 

the very soluble normal carbonate. Of the trona itself Chatard made 

several analyses, and he also prepared a series of artificial products, 

which established the true formula of the compound,1 The best 

specimen of trona from Owens Lake had the composition given in

f. also C. Winkler, Zeitschr. angew. Chemie, 1893, p. 446; and B. Reinitzer, idem, p. 573.
SALINE RESIDUES.

the first column below, which is compared with the composition as 

calculated theoretically.

Composition of trona from Oivens Lake, California.

Na2C03 . ...................................................

NaHC03 ..................................................

NaCI. .....................................................

Na,S04 . ..................................................

H26..... .................................................

Insoluble .................................................

Found.

45.86

36.46

.32

1.25

16.16

.02

100. 07

Calculated.

46. 90

37.17

15.93

100. 00

The prevalent view concerning the origin of the Lahontan alkalies 

was stated in Chapter V (p. 157). The waters of the Bonneville basin, 

or of Great Salt Lake, originate in an area of sedimentary rocks and 

contain chiefly substances which were formed during earlier concentrations. In one sense, then, we may call the residues of that region 

secondary depositions. The Lahontan area, on the other hand, is 

rich in volcanic materials, from which, by percolating waters charged 

with atmospheric or volcanic carbon dioxide, the soluble substances 

were withdrawn. These substances have accumulated in the waters 

of the basin, except for the calcium carbonate, which is now seen in 

the enormous masses of tufa so characteristic of the region. To Mono 

and Owens lakes, lying just outside of the Lahontan basin, the same 

observations apply. Alkaline carbonates, together with sulphates 

and chlorides, have been formed by solution from eruptive rocks, and 

concentrated in these waters and their residues. The seepage waters 

from fresh springs near Owens Lake percolate through beds of volcanic 

ash, and contain even a higher proportion of alkaline carbonates than 

the lake itself.1 The rocks from which the salts were originally 

derived seem to have been mainly rhyolites, andesites, and other 

varieties rich in alkalies and relatively poor in lime. Had lime been 

present in larger- quantities more calcareous sediments and gypsum 

would have formed, with less of the alkaline carbonates, or even 

none at all.

This theory, however, which attributes the presence of alkaline 

carbonates to a direct derivation from volcanic rocks, is not the only 

hypothesis possible. 'Even if it holds with respect to the Lahontan 

waters it is not necessarily valid elsewhere. In order to account for 

the existence of sodium carbonate in natural waters, T. Sterry Hunt 2 

assumed a double decomposition between sodium sulphate and calcium bicarbonate, gypsum being thrown down. A similar reaction

1 See analyses by T. M. Chatard, Ball. U. S. Geol. Survey No. GO, 1890, p. 94. Chatard also discusses the 

origin of the carbonates and cites the views of earlier investigators concerning other localities.

2 Am. Jour. Sci., 2d ser., vol. 28,1859, p. 170.
236 DATA OF GEOCHEMISTRY.

is accepted by E. von Kvassay * in his study of the Hungarian soda, 

only in this case sodium chloride is taken as the initial compound. 

The latter salt is supposed to react upon calcium bicarbonate, yielding sodium bicarbonate, which effloresces, while the more soluble 

calcium chloride, simultaneously formed, diffuses into the ground. 

E. W. Hilgard 2 has shown experimentally that both reactions are. 

possible, and that either sodium sulphate or sodium chloride can 

react with calcium bicarbonate, forming strongly alkaline solutions. 

From such solutions crystals of gypsum can be deposited, while 

sodium bicarbonate remains dissolved. In Hilgard's experiments, 

however, he precipitated and removed the calcium sulphate by 

means of alcohol, a condition unlike anything occurring in nature. 

S. Tanatar, 3 therefore, repeated the experiments without the use of 

alcohol and confirmed Hilgard's conclusions. The reverse reaction 

is hindered by the crystallization of the gypsum and the washing away 

or efflorescence of the soluble carbonate.

E. Sickenberger, 4 who examined the natron lakes of Egypt, observed the presence in them of algse, and noticed the evolution of 

hydrogen sulphide from their waters, iron sulphide being at the same 

time thrown down. He therefore ascribes the carbonates to the 

reduction of sulphates by organic matter, and subsequent absorption 

of carbon dioxide from the air. G. Schweinfurth and L. Lewin,5 on 

the contrary, while admitting that such a process can go on to some 

extent, regard it as capable of accounting for only a small part of the 

alkaline carbonates that are formed. These lakes deposit sodium 

chloride, sulphide, and carbonate; and the authors attribute the last 

salt to double decompositions with carbonate of lime. The percolating Nile water contains calcium bicarbonate, and the soil through 

which it reaches the lakes is rich in salt and gypsum. These two substances first react to form sodium sulphate and calcium chloride and 

the former then exchanges with calcium bicarbonate, as in Hunt's and 

Hilgard's investigations. Sodium chloride is taken as the starting 

point, and from it the sulphate and carbonate are derived.

We have, then, three theories by which to account for the formation of alkaline carbonates in natural waters and soils. 6 First, by

i Jahrb. K.-k. geol. Reichsanstalt, 1876, p. 427. Cf. also H. Le Chatelier on Algerian salts, Compt. Rend., 

vol. 84,1877, p. 396. Von Kvassay gives a bibliography of the Hungarian occurrences and some analyses 

of the soda.

»Am. Jour. Sci., 4th ser., vol. 2,1896, p. 123. See also paper in Rept. Univ. California Agr. Exper. Sta., 

1890, p. 87, followed by an experimental research by M. E. Jaffa.

s Ber. Deutsch. chem. Gesell., vol. 29,1896, p. 1034. See also a memoir by H. Vater, Zeitschr. Kryst. 

Min.,vol. 30,1899, p. 373.

«Chem. Zeitung, 1892, pp. 1645,1691.

* Zeitschr. Gesell. Erdkunde, vol. 33,1898, p. 1. Several references to bacteriologic researches are given 

in this memoir.

6 To these theories may be added a fourth, that of C. Ochsenius (Zeitschr. prakt. Geologic, 1893, p; 198), 

who supposes that the alkaline carbonates have been formed by the action of carbon dioxide, commonly' 

of volcanic origin, on the "mother-liquor salts." The evidence in favor of this view is so slender that a 

discussion of it would be hardly worth while.
SALINE KESIDUES. 237

direct derivation from volcanic rocks. Second, by reduction of 

alkaline sulphates. Third, by double decomposition between calcium bicarbonate and alkaline sulphate or chlorides. All three are 

possible, and all three are doubtless represented by actual occurrences 

in nature. The presence of sodium carbonates in the waters of hot 

springs, which, it may be observed, are common in the Lahontan 

basin, "we can ascribe to the operation of the first process; the second 

mode of derivation is effective wherever alkaline sulphates and 

organic matter are found together; the third method is perhaps the 

most general of all. To the action between alkaline salts and calcium bicarbonate, Hilgard attributes the common presence of sodium 

carbonate in the soils of arid regions, a mode of occurrence which 

is very widespread and of the utmost importance to agriculture. 

The reclamation of arid lands by irrigation is profoundly affected 

by the presence of these salts, which sometimes accumulate to such 

an extent as to destroy fertility. Excessive irrigation may defeat 

its own purpose and destroy the value of land which might be 

reclaimed from the desert by a more moderate procedure.1 The 

soluble salts which exist below the surface, being dissolved, rise by 

capillary attraction and form the objectionable crusts of "alkali." 

A very unusual saline deposit, in certain lakes of Washington and 

British Columbia, has been described by 0. P. Jenkins.2 These 

lakes deposit magnesium sulphate, epsomite, in quantities sufficient 

to be commercially valuable. Probably sulphuric acid, derived 

from the oxidation of iron sulphides, has acted upon dolomite and

other magnesian rocks.

B ORATES.

Borates and nitrates are much.less frequently deposited and in 

much smaller amounts than the salts which we have so far been considering. They are, however, important saline residues and deserve 

a more extended study than they seem to have yet received. In 

the chapter upon closed basins attention was called to the Borax 

Lake of northern California, and among mineral springs a number 

containing borates were noted. The latter were hot springs, situated 

in volcanic regions, as in the Yellowstone Park a mode of occurrence which must be borne in mind if we are to determine the origin 

of these substances. We must also remember that borates exist in 

sea water, from which source the deposits at Stassfurt are supposed 

to be derived. Two sets of facts, therefore, have to be considered

i The reports of tho Bureau of Soils, U. S. Dcpt. Agr., and of the agricultural experiment stations of several Western States contain abundant literature on this subject. The report of tho Division of Soils for 

1900 contains a paper by F. K. Cameron on the application of the theory of solution to the study of soils 

in which tho generation of alkaline carbonates by double decomposition is discussed on the basis of modern 

physical chemistry. In Bull. 42 of the New Mexico College of Agriculture there is a summary of the literature on alkali soils. A remarkable deposit of natron in San Luis Valley, Colorado, is described by 

W. P. Hcaddon, Am. Jour. Sci., 4th sen, vol. 27,1909, p. 305.

a Am. Jour. Sci., 4th ser., vol. 40,1918, p. 638.
238 DATA OF GEOCHEMISTRY.

in. dealing with this class of compounds. Let us first examine the 

actual occurrences of borates as saline residues.1

Borax Lake, Lake County, California, has been repeatedly described.2 Its water contains chiefly sodium carbonate and sodium 

chloride, with borax next in importance, and it deposits the lastnamed salt in crystals, some of which are several inches long. More 

borax, however, was furnished by a neighboring smaller lake, Hachinchama. The supply probably came, according to Becker, from 

hot springs near the lakes, and one spring, of which the analysis 

has already been given, contains not only boron, but also a surprising quantity of ammonium compounds. The same association of 

borates with ammoniacal salts is also to be observed in the waters 

of the Yellowstone Park, and especially in that unique solution 

known as " the Devil's Inkpot." The hot springs of the Chaguararna 

Valley, in Venezuela,3 furnish a similar example; and here again, as in 

sOme of the California localities described by Becker, sulphur and 

cinnabar are deposited. Boric acid and ammonium chloride are 

among the volcanic products of the island of Volcano; 4 but the 

famous "soffioni" or "fumaroles" of Tuscany are of much greater 

importance. - Here jets of steam carrying boric acid emerge from the 

ground and supply great quantities of that substance for industrial 

purposes. The following compounds of boron are deposited by the 

lagoons in which the boric-acid vapors are concentrated:

Sassolite...................................H8B03 (orthoboric acid).

Larderellite................t............. .(NH4)2B8013 .4H20.

Bechilite.................................CaB407 .4H20 (borocalcite).

Lagonite.................................. .T?e///2BQ012 .3'K20.

One of these' salts is an ammonium borate and another ammonium 

compound boussingaultite, (NH4) 2Mg(SO4) 2 -6H2O is also formed 

at this locality. According to C. Schmidt 5 the condensible vapors 

from the fumaroles of Monte Cerboli contain borio acid and ammonia in considerable amounts, with much less hydrogen sulphide. 

Water issues with the vapors, and in samples condensed from several 

vents C. M. Kurtz 6 found solid contents ranging from less than 1 

to more than 7 grams per liter. Four of the lagoon waters examined 

by Kurtz contained the following quantities of foreign matter:

1 For general information about American localities see Mineral Resources TJ. S. for 1882, TJ. S. Geol. 

Survey, p. 566; 1883-84, p. 858; 1889-90, p. 494; and 1901, p. 869.

2 Geol. Survey California, Geology, vol. 1, 1865, p. 97. G. F. Becker, Mon. U. S. Gecl. Survey, vol. 13, 

1888, pp. 264-268. H. G. Hanks, Third Ann. Kept. State Mineralogist (California).' For analyses of tho 

water and of an adjacent hot spring, see ante, p. 156. This lake, situated about 80 miles north of San Francisco, must not be confused with Searles's "Borax Lake" in San Bernardino County.

a See E. Cortese, Eng. and Min. Jour., vol. 78, November 10,1904. ,

4 Sec A. Bergeat, Zeitschr. prakt. Geologic, 1899, p. 45. .,.

6 Ann. (Them. Pharra., vol. 98,1856, p. 273. In vol. 102,1857, p. 190, Schmidt also describes the rqcjcs 

of tho region.

o Dingler's Polyt. Jour., vol. 212,1874, p. 493.
SALINE RESIDUES. 239

Foreign matter 'in Tuscan lagoon waters.

[Grams per liter.]

Monte Rotondo, uppermost lagoon. . .........

Total solids.

8.565

C.720

2.005

22. 575

Boric acid 

(H3B03 ).

4.154

4.032

1.100

19. 300

Ammonium 

sulphate.

1. G95

.760

.253

.587

The high figures of the last example represent a concentration 

from all the upper waters, which are united at the lowest level. In 

the dark-brown sediment of the lagoons Schmidt found gypsum, ammonium sulphate, ammonium thiosulphate, ammonium sulphide, 

ammonium carbonate, magnesia, and a little soda and potash mixed 

with a clay derived from dolomite and colored by iron sulphide. He 

also analyzed the mother liquor left by the lagoon waters after most 

of their borio acid had been deposited. I have reduced his analysis 

to percentages of total solids, and essentially to ionic form, except 

that for the excess of borio acid I prefer to use the symbol H3B03 . 

Schmidt gives the total solids as 16.374 grams per liter, reckoning 

the free acid as B203 ; as recalculated the sum becomes 18.548. The 

revised figures are as follows:

Analyses of mother liquor from Tuscan lagoon water.

Grams 

per liter.

Cl.............................. 0.39

S04 ............................. 49.37

B03 in borates.................. 2. 50

H3B03 .......................... 26. 92

Na.............................. .89

K.............................. 1. 01

NH4 ............................. 10.71

Grams 

per liter.

Ca............................... 0.16

Mg............................. 1. 99

(Al,Fe)203 .'..................... .06

Mn203 ...........................Trace.

Si02 .............................Trace.

100. 00

In the light of all the foregoing data, we may reasonably assume 

that there is a relation between boric acid and ammonium, at least 

wherever hot springs carry appreciable quantities of borates. The 

boron and nitrogen appear together, a fact which has led to the 

hypothesis that boron nitride, decomposed by steam, has been the 

parent compound.1

Boron nitride, BN, is a well-known artificial substance; it is very 

stable and, with steam, gives the required reaction, but it has not yet

1 R. Warington, Chem. Gaz., 1854, p. -119, with special reference to Vulcano, Lipari Islands. H. Sainte 

Claire Dovilloand F. Wohler, Ann. Chem. Pharm., vol. 105,1S58,p. 71. O. l5 opp,Mem,8thsupp. Bd.,1870, 

p. 5!" '13. Bechi, Bull. Soc. incl. min., vol. 3,1857-58, p. 329. A. Lacroix (Compt. Rend., vol. 147,1908, 

p. 161) has found ammonium chloride and boric acid in recent fumaroles of Vesuvius.
240 DATA OF GEOCHEMISTRY.

been observed as a natural mineral species. Its invocation, then, as 

an agent in the production of borates is purely hypothetical, however 

probable it may be. The same objection applies to Dumas's supposition that boron sulphide, B2S3 , also decomposed by steam, was the 

source of the boric acid contained in the '' soffioni." 1 That hypothesis 

was indicated by the presence of hydrogen sulphide in the boronbearing vapors. P. Bolley 2 suggested that a reaction of ammonium 

chloride on borax, which he proved to be experimentally possible, 

might give rise to the observed phenomena; and E. Bechi,3 in a later 

memoir than the one previously cited, traces the borates to the neighboring ophiolitic serpentines, in which he found at least one inclusion of datolite, a borosilicate of lime. The serpentine, heated to 

300° in a current of steam and carbonic acid, yielded borio acid, 

ammonium compounds, and hydrogen sulphide the very products 

found in the fumaroles. Serpentine, however, is a secondary rock, and 

may have derived its borates and ammonium salts from the solutions 

which brought about the transformation of the original gabbro.

In recent years E. Perrone 4 and R. Nasini 5 have suggested that the 

Tuscan boric acid may be derived from the decomposition, by water, 

of tourmaline contained in deep-seated granites. Nasini supports this 

opinion by showing that steam at high temperature extracts boric 

acid from-tourmaline. The suggestion, however, does not account 

for the ammonium compounds associated with the boric acid.

An entirely different mode of occurrence for borates is shown on 

an extensive scale in Nevada.and southern California and at a few 

localities in Oregon.6 Here borax, as such, is found in considerable 

quantities; but the calcium salts ulexite and colemanite are by far the 

more important species.

1 See paper by A. Payen on the Tuscan fumaroles, Annales chim. phys., 3d ser., vol. 1,1841, p. 247. He' 

adopts Dumas's theory.

" Ann. Chem. Pharm., vol. 68,1848, p. 125.

s Atti R. accad. Lincei, 3d ser., vol. 2,1878, p. 514. See also a summary by H. Scruff in Ber. Deutsch. 

chem. Gesell., vol. 11,1878, p. 1690.

«Carte idrographica d'ltalia, No. 31,1904, p. 355.

6 Abstract in Geol. Centralbl., vol. 8,1906, p. 413; and Atti R. accad. Lincei, 5th ser., vol. 17,1908, p. 43. 

For criticisms of Perrone and Nasini, see G. d'Achiardi, Atti Soc. toscana sci. nat., Memorie, vol. 23,1907, 

p. 8, and Rend. R. accad. Lincei, 5th ser., vol. 17,1908, p. 238. For a long paper on the origin of boric acid 

and the borates, see A. d'Achiardi, Atti Soc. toscana sci. nat. Pisa, 1878, vol. 3, fasc. 2.- Earlier memoirs 

are by H. Coquand, Bull. Soc. geol. Franco, 2d ser., vol. 6,1848-49, p. 91; C. Sainte-Claire Deville and F. 

Leblanc, Compt. Rend., vol. 45,1857, p. 750; vol. 47,1858, p. 317; and F. Fouqu6 and H. Gorceix, idem, 

vol. 69,1869, p. 946. The gases from the "soffioni" have been studied by R. Nasini, F. Anderlini, and 

R. Salvador! (Atti R. accad. Lincei, 5th ser., Memorie, vol. 2,1895, p. 388), as well as by some of the abovenamed authorities. Carbon dioxide is the principal gas..

a See H. G. Hanks, Third Ann. Rept. State Mineralogist California, 1883, and Am. Jour. Sci., 3d ser., vol. 

37,1889, p. 63; H. De Groot, Tenth Ann. Rept. California State Mining Bureau, 1890; G. E. Bailey, The 

saline deposits of California: Bull. No. 24, California State Mining Bureau, 1902. For the geology of the 

borax deposits in Death Valley and the Mohave Desert, see M. R. Campbell, Bull. U. S. Geol. Survey No. 

200,1902, and an article in Eng. and Min. Jour., vol. 74,1902, p. 517. An important memoir on the borax 

deposits of the United States, by C. R. Keyes, is in the Bull. Am. Inst. Min. Eng., 1909, p. 867.
SALINE RESIDUES. 241

In Esmeralda County, Nevada, at Teel's marsh, Rhodes's marsh, 

Columbus marsh, and Fish Lake, ulexite, NaCaB508 .8H2 0, is the 

principal borate. It occurs in nodules, known locally as "cotton 

balls," which have a fibrous structure and seem to be in process of 

formation, the smaller masses gradually becoming larger. 1 At 

.Rhodes's marsh, according to Joseph Le Conte,2 the central part of 

the area is occupied by a bed of common salt, around which there are 

deposits of sodium sulphate. Beyond the sulphate beds the borax 

and ulexite are found. These "marshes," which are really playa 

lakes, are of secondary origin; and M. R. Campbell, speaking of the 

similar formations in California, 3 attributes their borates to teachings 

from beds of Tertiary sediments.

The borates of southern California are widely scattered over a large 

area, which is practically a continuation of the Nevada field. They 

are found especially in Inyo and San Bernardino counties, in Death 

Valley, along the basin of the Amargosa River, and elsewhere. The 

locality known as Searles's marsh, or Searles's borax lake, has been 

worked since 1873; and as it has yielded a number of new mineral 

species, it deserves special consideration here. In chemical interest 

it rivals Stassfurt, although its systematic study is hardly more than 

begun. Borings at this point, according to De Groot, 4 have revealed 

the following succession of deposits:

Section at Searles's marsh, San Bernardino County, California.

Feet.

1. Salt and thenardite........................................ 2

2. Clay and volcanic sand, with some hanksite.................. 4

3. Volcanic sand and black clay, with bunches of trona......... 8

4. Volcanic sand, containing glauberite, thenardite, and a few 

crystals of hanksite...................................... 8

5. Solid trona, overlain by a thin layer of very hard material..... 28

6. Mud, smelling of hydrogen sulphide and containing layers of 

glauberite, soda, and hanksite............................. 20

7. Clay, mixed with volcanic sand and permeated with hydrogen

sulphide................................................. 230+

The borax of Searles's marsh is found chiefly in the top crust, or 

crystallized in the water which sometimes accumulates in the depressions of the bed. This layer is reproduced by slow degrees, through 

capillary action, which brings up the soluble salts from below, so that

1 Rept. State Mineralogist Nevada, 1871-72, p. 35.

2 Third Ann. Rept. State Mineralogist California, 1883, p. 51.

s Bull. U. S. Geol. Survey No. 213,1903, p. 401. See also J. E. Spurr, Bull. U. S. Geol. Survey No. 208, 

1903.

4 Tenth Ann. Rept. California State Mining Bureau, 1890, p. 535. The brine of Searles's marsh is now 

being exploited as a source of potassium compounds.

113750° 19 Bull. 695 16
242 DATA OF GEOCHEMISTRY.

the same area can be repeatedly worked over.- In the workings the 

following mineral species have been found i 1

Anhydrite....................................CaSQ4 .

Gypsum......................................CaS04 .2E2O.

Celestite.........t...........................SrS04.

Thenardite.................................

Mirabilite..................................

Glauberite .................................

Sulphohalite^.............................

Hanksite.....................................Na22K(S04)9(C03)2Cl.

Borax.......................................Na2B407 .10H20.

Colemanitc. ................... ^ ............. .Ca2B6Ou .5H20.

Calcite.......................................CaC03 .

Dolomite.....................................MgCa(C03)2 .

Natron.......................................NaC03 .10H20.

Trona....................................... .Na3H(C03)2 .2H20.

Gaylussitc 3 ................................

Pirssonitc 3 .................................

Northupite 3 ..................................Na3Mg(C03)2Cl.

Tychite *..................................... .Na6Mg2(C03)4S04 .

Halite................................-.--..Nad.

Soda niter .................................. .NaN03 .

Searlesite 5 ....................................Na2O.B203 .4Si02 .2H20.

Sulphur, from reduction of sulphates.6

In the water from 15 feet below the crust, or "crystal layer," 

ammonium salts are reported to occur a fact which becomes peculiarly significant when it is considered in connection with the, presence 

of soda niter also. To this point we shall recur later. It is evident 

that the paragenesis of all these mineral species presents a complex 

chemical problem, quite analogous to that investigated by Van't Hoff 

in his studies of the Stassfurt beds.

About 12 miles north of Daggett, in the southern part of San 

Bernardino County, a still different borate deposit is found. 7 Here, 

interstratified with lake sediments, a solid bed of colemanite exists, 

which ranges from 5 to 30 feet in thickness and is highly crj^stalline.

1 De Groot also mentions cerargyrite, embolite, and gold; but these minerals have no obvious relationship 

to the other species.

2 S. L. Penfleld, Am. Jour. Sci., 4th ser., vol. 9,1900, p. 425.

3 J. H. Pratt, Am. Jour. Sci., 4th ser., vol. 2,1896, p. 123 et seq.; vol. 3,1897, p. 75.

< S. L. Penfleld and G. S. Jamieson, idem, vol. 20,1905, p. 217. The authors prepared tychite synthetically. Both northupite and tychite have also been made artificially by A. B. de Schulten, Bull. Soc. 

Min., vol. 19,1896, p. 164, and Compt. Rend., vol. 143,1906, p. 403. The relations between the two species 

are perhaps more clearly expressed by formulae of the following type:

Tychite............................................................2MgC08.2Na3CO3 .Na2S04

Northupite.........................................................2MgCO3.2Na2CO3.2NaCl.

On gaylussite and pirssonite, see R. Wegscheider and H. Walter, Monatsh. Chemio, vol. 28,1907, p. C33.

5 E. S. Larsen and W. B. Hicks, Am. Jour. Sci., 4th ser., vol. 38,1914, p. 437. Searlesite is peculiarly 

interesting as the first known example of an alkaline borosilicate.

8 For a full description of the minerals of Searles's marsh, see H. S. Gale and W. T. Schaller, Bull. U. S. 

Geol. Survey No. 580,1914, pp. 296-308. On pp. 276 and 277 Gale cites analyses of the brine of the marsh 

or "lake."

' See M. R. Campbell, Bull. U. S. Geol. Survey No. 200, and W. II. Storms, Eleventh Ann. Kept. California State Mining Bureau, 1893, p. 345. .
SALINE RESIDUES. 243

At one end the colemanite is much mixed with sand, gypsum, and 

clay, suggesting that it had been laid down at the edge of an evaporating sheet of water. Campbell regards the borax of the Amargosa 

marshes as probably derived from the leaching of deposits similar to this. H. S. Gale,1 however, who has more recently studied 

the colemanite, regards it as a vein mineral.

From another point in the Mohave Desert a mineral has been reported 2 (bakerite), having the empirical formula 8CaO.5B2O3 .6Si02 . 

6ELO; but its definite character is yet to be ascertained. Priceite, 

a related mineral, is found in Curry County, Oregon, on the shore of 

the Pacific. It occurs in compact nodules, from the size of an egg up 

to several tons in weight, associated witK serpentine.3 Pandermite, 

another similar borate, from near Panderma, on the Sea of Marmora, 

also forms nodules, but in a bed underlying a thick stratum of gypsum. Colemanite and its modifications, then, exist under a variety 

of different conditions, and we can not say that it has always been 

produced in the same way. It is stated by Campbell, 4 however, that 

the lake-bed deposits of California were probably laid down during 

a period of volcanic activity.

Both colemanite and pandermite have been prepared artificially 

by J. H. Van't Hoff,5 who acted on ulexite (boronatrocalcite) with 

saturated solutions of alkaline chlorides. With a solution of sodium 

and potassium chlorides at 110° pandermite was formed to which 

Van't HofF assigns the formula Ca8B20038 .15H20. Colemanite, 

Ca2BQ On .5H2 0, forms from ulexite in a sodium chloride solution most 

readily at 70°. Van't Hoff, it will be noticed, does'not regard pandermite and colemanite as identical. E. S. Larsen 6 has more recently come to the same conclusion, and has also shown that priceite 

and pandermite are one species.

Immediately south of Lake Alvord, in Harney County, Oregon, an 

extensive marsh is covered by an incrustation containing borax, salt, 

sodium sulphate, and sodium carbonate in varying proportions. 7 

This locality has been worked for borax, .and the deposit is said to be 

continually reproduced. The region calls for more complete examination, especially on the chemical side.

In the arid region of southern California beds containing sodium 

nitrate are found near the borate deposits. The same association, if 

we can justly call it so, also exists in South America, where the soda 

niter of the Tarapaca and Atacama deserts is accompanied, more or

1 Prof. Paper U. S. Geol. Survey No. 85,1913, p. 3.

2 W. B. Giles, Mineralog. Mag., vol. 13,1903, p. 353.

3 Information received from J. S. Diller, who has examined the locality.

* Eng. and Min. Jour., vol. 74,1902, p. 517.

» Sitzungsb. Akad. Berlin, vol. 39,1900, pp. 56G, GS9.

0 Am. Mineralogist, vol. 2,1917, p. 1.

7 W. D. Dennis, Eng. and Min. Joim, vol. 73,1902, p. 581.
244 DATA OF GEOCHEMISTEY.

less closely by ulexite. As early as 1844 A. A. Hayes 1 described the 

calcium borate from near Iquique, and noted its association with 

glauberite, gypsum, pickeringite, and a native iodate of sodium. 

D. Forbes,2 describing more fully the salines of this region, which he 

regarded as post-Tertiary, added salt, epsomite, mirabilite, thenardite, 

glauberite, soda alum, anhydrite, soda niter, and borax to the list of 

species. The salines themselves Forbes attributed to the .concentration of sea water, but the borates were, he believed, of volcanic origin. 

They occur in the more elevated parts of the saline region, in which 

he found active fumaroles; but the latter were not examined for 

boron. Later 3 he was able to confirm this view by finding a calcium 

borate, either ulexite or bechilite, actually in process of deposition 

at the hot springs of Banos del Toro, in the Cordilleras of Coquimbo. 

L. Darapsky, in his work on the Taltal district, 4 speaks of ulexite as 

a regular companion of the nitrates, and especially notes the presence 

of borates in the waters of a lagoon at Maricunga. The borax " lake'' 

of Ascotan, according to R. T. Chamberlin,5 derives its borates, 

mainly ulexite, from leachings from adjacent volcanoes.

Farther east, in Argentina, several borate localities are known. 

J. J. Kyle 6 describes ulexite, associated with glauberite, from the 

Province of Salta, and refers to its existence in Catamarca. It is also 

found at Salinas Grandes, Province of Jujuy, according to H. Buttgenbach,7 who describes the occurrence in some detail. The center 

of the deposit is covered with rock salt 20 to 30 centimeters in thickness, and around its borders the ulexite nodules are unevenly distributed. Gypsum, soda niter, glauberite, and pickeringite are also 

found with it, the gypsum predominating, Boracite and carnallite 

are absent. The locality is overflowed in spring by water from the 

mountains, but is dry in summer, and Buttgenbach expresses the 

opinion that ulexite is produced every year at flood time. It will 

be remembered that this same phenomenon of growth was noted in 

connection with the Nevada mineral. The boric acid of the ulexite 

is regarded by Buttgenbach as being of volcanic origin.8 The same 

view is held by A. Jockamowitz 9 with regard to the ulexite of the 

Salinas Lagoon, Province of Arequipa, Peru.

1 Am. Jour. Sci., 1st ser., vol. 47,1844, p. 215.

2 Quart. Jour. Geol. Soc; London, vol. 17,1861, p. 7.

3 Philos. Mag., 4th ser., vol. 25,1863, p. 113.

«Das Departement Taltal (Chile), Berlin, 1900. See especially pp. 149,150,163. An abstract is printed 

in Zeitschr. p'rakt. Geologie, 1902, p. 153.

6 Jour. Geology, vol. 20, p. 763,1912.

6 Anales Soc. cient. Argentina, vol. 10,1S80, p. 169.

i Annales Soc. g<5ol. Belgique, vol. 28, M, 1900-1901, p. 99. Analyses of the ulexite are given.

8 In Chem. Zeitung, vol. 30,1906, p. 150, F. Reichert describes eight of the Argentine " borateras" and 

gives analyses of their products. His complete report, Los yacimientos de boratos, etc., is in Anales del 

Ministerio de agricultura, Buenos Aires, 1907. For an abstract, see Zeitschr. Kryst. Min. ; vol. 47,1009. 

p. 205.

 Bol. Cuerpo ing. minas, Peru, No. 49,1907.
SALINE RESIDUES. 245

The old localities for borax in Tibet and the adjacent region 

have been little visited by Europeans, and detailed information 

concerning them is very scanty. H. von. Schlagintweit,1 however, 

has described the great borax deposits of the Puga Valley, in Ladak, 

where the mineral covers the ground over a large area to an average 

depth of 3 feet. The borax is a deposit from hot springs, which 

issue more than 15,000 feet above sea level, at a temperature ranging 

from 54° to 58° C. The saline mass also contains free boric acid 

and sulphur, with less salt, ammonium chloride, magnesium sulphate, 

and alum, and there is much gypsum in its vicinity. No ulexite 

was found.

On the peninsula of Kertch, near the Sea of Azov, borax occurs 

among the erupted substances of the so-called "mud volcanoes." 2 

It effloresces upon the surface of the dried mud, and is more or less 

mixed with salt and soda.

Since borates are present in sea water, it follows that they must 

also occur among the products of its evaporation. This conclusion 

is best verified at Stassfurt, where the following species are found:3

Boracite.........................................Mg7Cl2Bi003o.

Pinnoite.....................................MgB204 .3H20. "'/

Ascharite......................................3Mg2B205.2H20.

Heintzite.....................................K2Mg4B22038 .14H20.

Hydroboracite (?)............................ .CaMgB6On .6H20.

Sulphoborite.......... s.......................2MgS04 .4MgHB03 .7H20.

Of these species, hydroboracite is found in the lower deposits at 

Stassfurt,4 associated with anhydrite; the others are characteristic 

of the carnallite zone. That is, they are mother liquor salts, and 

among the latest substances to crystallize. It is also to be noted 

that they are essentially magnesian borates, and that calcium, 

which is the dominant metal in the Chilean and Californian localities, 

occurs in only one of the Stassfurt species. This is what we should 

expect from sea water, in which magnesium is abundant and calcium 

relatively subordinate. In any general discussion of the genesis of 

borates this distinction must be borne in mind.5

In the gypsum beds of Nova Scotia ulexite, howlite, and cryptomorphite are found, associated with anhydrite, selenite, mirabilite, 

salt, aragonite, and calcite. 6 Howlite is represented by the formula 

H5CaB2Si014 ; cryptomorphite 7 is probably H2Na4Ca6 (B407 ) 9 .22H20. 

If this gypsum is, as most authorities assume, a marine deposit

i Sitzungsb. Acad. Munchen, vol. 8,1878, p. 518.

« W. S, Vcrnadsky and S. P. Popoff, Zeitschr. prakt. Geologic, 1902, p. 79.

« Liincburgite, a magnesium borophosphatc found with the potash salts of Liincburg, Hannover, may 

fairly bo included with this list.

< In his paper on the borates of the German potash salts, H. E. Boeke (Centralbl. Min., Gcol. u. Pal., 

1910, p. 531) docs not mention hydroboracite. Its identification is, perhaps, not quite certain.

« Seo also W. Biltz and E. Marcus (Zeitschr. anorg. Chemic, vol. 72,1911, p. 302) on the borates of Stassfurt.

8 See H. How, Am. Jour. Sci., 2d ser., vol. 32,1861, p. 9; Philos. Mag., 4th ser., vol. 35,1868, p. 31; vol. 41, 

1871, p. 270.

' Calculated by F. W. Clarke from How's analysis.
246 DATA OF GEOCHEMISTRY.

these salts occupy a position similar to that filled by hydroboracite 

at Stassfurt, but the total absence of magnesium, is rather striking.1

In order to account for the origin of boric acid and saline borates, 

three hypotheses have been proposed and strenuously advocated. 

First, they may be derived from the leaching of rocks containing 

borosilicates, such as tourmaline, axinite, dumortierite, danburite, 

and datolite. Second, ithey are supposed to be of volcanic origin. 

Third, they are regarded as marine deposits. Probably each mode 

of derivation is represented by actual occurrences in nature, as may 

be judged from the evidence brought forward in the preceding 

pages, but the first supposition has not been directly tested at any 

known locality. Many rocks, especially granites and mica schists, 

contain tourmaline; they undergo decomposition, and boric acid 

is washed away; but borates from that sourc'e have not been found 

to accumulate in any known saline residue. They may do so, but 

they have not been directly traced. If, however, it could be shown 

that volcanic borates came from the thermal metamorphism of 

tourmaline-bearing rocks, the first and second hypotheses might 

be partly unified. Even then the question of the formation of 

soluble borates by weathering would be untouched.

The volcanic theory seems to fit a considerable number of borate 

localities, although its application to some cases may have been 

forced, and for others its validity has been doubted. Several 

writers have denied the volcanic character of the Tuscan fumaroles, 

despite the thermal activity of the region and the presence in it of 

eruptive rocks.2 That boric acid is emitted from volcanic vents is, 

however, unquestionable. It is there associated with ammonium 

salts precisely as it is at Monte Cerboli an association which can 

not be overlooked or .disregarded.

The marine origin of borates is most evident at Stassfurt, although 

even here their presence has been attributed to the injection of 

volcanic gases. Here, however, and also in the gypsum beds of 

Nova Scotia the nitrogen compounds are lacking, a clear distinction 

from the presumably volcanic occurrences. At Stassfurt the volcanic hypothesis seems to be quite superfluous, and the derivation 

of all the saline substances which there coexist can be most easily 

explained as due to the concentration of sea water. The existence 

of borates in the latter is clearly established; but whence were they 

derived? Any answer,to that question must be purely speculative. 

Whether we invoke the aid of submarine volcanoes or attribute

1 The suggestion of J. "W. Dawson (Acadian geology, 1891, p. 262) that these enormous masses of gypsum 

were produced by the action of acid volcanic waters on limestone is of doubtful significance. The region, 

"however, contains eruptive rocks in great abundance, a fact which may partly justify the speculation.

2 See, for example, a letter from W. P. Jervis, published by H. G. Hanks in Third Ann. Kept. State 

Mineralogist California, 1883, p. 68; also L. Dieulafait, Compt. Rend vol. 100,1885, p. 1240.
SALINE RESIDUES. 247

our borates to teachings from the land, we go beyond the limits of 

our knowledge and remain unsatisfied.

Confining ourselves, then, to considerations of a proximate character, we may fairly assert that certain borate localities are of volcanic 

and others of oceanic origin. Nevertheless, attempts have been made 

to explain all these deposits by the marine hypothesis, as in the 

memoirs of C. Ochsenius * and L. Dieulafait.3 Dieulafait tries to 

prove that all saline deposits are primarily derived from sea water, 

in either ancient or modern times, and even the Tuscan "spffioni" 

are supposed by him to draw their boric acid from subterranean saliferous sediments. Mother liquors, rich in magnesium chloride and 

heated by steam, are thought to liberate hydrochloric acid, which, 

acting upon the magnesium borates, sets boric acid free, to be carried 

upward by the escaping vapors. These reactions are possible, but it 

is not proved that they have actually occurred. Ochsenius also argues 

in much the same way, and points out that beds of rock salt exist at 

no very great distance from the region of fumaroles. Their mother 

liquors are to his mind the source of the boric acid.

If we turn to the ulexite and colemanite beds of California and 

Chile, we find a distinct set of phenomena to be interpreted. Here we 

deal undoubtedly with ancient lake beds, but the residues contain 

calcium, not magnesium borate. Some of the deposits are below sea 

level, as at Death Valley; others are thousands of feet above, as at 

Maricunga; and in or near all of them nitrates are also found. Hot 

springs are common in both regions, in California as well as in Chile; 

but they have not been exhaustively studied. Do they contain boric 

acid and ammonia? If so, did the lake beds derive their nitrates 

from such sources'? These questions are legitimate ones for future 

investigators to answer, and the replies may help to solve the problem 

now before us. Ammonia, by oxidation, yields nitric acid a reaction which has been studied exhaustively in the interests of agriculture. Forbes found a calcium borate forming in a Chilean hot 

spring.3 Magnesium borates do not occur in either group of localities. 

From these facts we see that a volcanic origin is conceivable for the 

deposits in question, whereas a marine source is not at all clearly 

indicated. Neither hypothesis can be adopted with any degree of 

assurance; but the volcanic theory is the more plausible of the two. 

As we pass on to the study of the nitrate beds, these suggestions may 

become a little clearer. For the moment, the following summary 

may serve to assist future discussion:

(1) Marine deposits contain magnesium borates.

i Zeitsehr. prakt. Geologic, 1893, pp. 189,217. Borates especially on pp. 222, 223.

a Annales chim. phys., 5th scr., vol. 12, 1877, p. 318; vol. 25, 1882, p. 145. Also Compt. Rend., vol. 850 

1877, p. 605; vol. 94,1882, p. 1352; vol. 100,1885, pp. 1017,1240.

3 Some of tho Chilean thermal waters, analyzed by P. Martens (Actcs Soc. sci. Chili, vol. 7,1897, p. 311), 

contain both borates and ammonium salts, but not in remarkable proportions.
248 DATA OF GEOCHEMISTRY.

(2) L'ake-bed deposits contain calcium borates, with nitrates 

near by.

(3) Volcanic waters and fumaroles, when they yield borates, yield 

ammonium compounds also.

NITRATES.

Nitrates are commonly formed in soils by the oxidation of organic 

matter, a process in which the nitrifying micro-organisms play an 

important part.1 In moist climates these salts remain in the ground 

water, are consumed by growing plants, or are washed away; in arid 

or protected regions they may accumulate to a considerable extent. 

Some nitrates are also derived from atmospheric sources, the acid 

being formed by electrical discharges and brought down by rain, but 

their amount is probably only a small portion of the entire product. 

Wherever organic matter putrefies in contact with alkaline materials, 

such as lime or wood ashes, nitrates are produced a process which 

has been carried on artificially in various countries in order to supply 

the industrial demand for saltpeter. In sheltered places, such as 

caverns, calcium nitrate is often produced in large quantities, and its 

formation has commonly been attributed to the nitrification of bat 

guano.2 This supposition, however, may not cover all cases, for 

W. H. Hess 3 claims that nitrates are uniformly distributed over cave 

floors in Kentucky and Indiana, even in the remote interiors of caverns where no guano exists. In drippings from the roof of the Mammoth Cave he found 5.71 milligrams per liter of N205, whose source 

he ascribes to percolating waters from outside. The cave, in his 

opinion, acts as a receptacle for stopping a part of the surface drainage, in which nitrates are produced in the usual way. Earth gathered 

far within the cavern contains nitrates, but almost no organic matter. 

The deposits of potassium nitrate found in Hungary are traced by 

C. Ochsenius 4 to the mother liquors of sea water, their potassium 

chloride being first transformed to carbonate, which latter is then 

nitrified in presence of organic substances. In this suggestion .the 

hypothetical element is rather large, although it is plausibly defended.

We have already noticed the existence of soda niter among the minerals of Searles's marsh, and its probable association with ammonium

1 See for example W. P. Headden (Proc. Colorado Sci. Soc.. vol. 10, 1911, p. 99), on unusual accumulations of nitrates in certain Colorado soils. He cites other literature.

2 See A. Muntz and V. Marcano, Ann. chim. phys., 6th ser., vol. 10,1887, p. 550, on cave earth from Venezuela. For an account of saltpeter earth in Turkestan see N. Ljubavin, Jour. Chem. Soc., vol. 48,1885, p. 

128. On nitrate earth at Tacunga, Ecuador, see J. B. Boussingault, Annales chim. phys., 4th ser., vol. 7, 

1866, p. 358, followed by a letter from Chabrie" on Algerian saltpeter. M. Glasenapp (Ann. gdol. min. 

Russie, vol. 12,1910, p. 42, abstract) describes an impregnation of potassium nitrate in the Senonian sandstones of the Caucasus. On nitrate shales in Egypt see W. F. Hurne, M6m. Inst. 6gyptien, vol. 8,1915, p. 

145. From notice in Geol. Mag., 1916, p. 328.

'Jour. Geology, vol. 8, 1900, p. 129. The views advanced by Hess have been disputed by H. W. 

Nichols (Jour. Geology, vol. 9,1901, p. 236), who regards guano as the chief source of cave nitrates.

<Zeitschr. prakt. Geologic, 1893, p. 60.
SALINE RESIDUES. 249

compounds. The same substance is also reported to occur in large 

quantities at various other points in southern California, especially 

around Death Valley and along the boundary between Inyo and 

San Bernardino counties.1 It is said to form beds associated with 

the later Eocene clays, and in some cases to impregnate the latter; 

but its direct conjunction with borates is not positively asserted, 

except in the locality at Searles's marsh. The fact that soda niter 

exists in the same region with the borates is important, however, for 

it correlates the California deposits with the Chilean beds, where a 

similar relationship is recognized. According to Bailey,2 the rare 

species darapskite and iiitroglauberite, previously known only from 

Chile; are also found in the nitrate beds of California.

In the deserts of Atacama and Tarapaca, in the northern part of 

Chile,3 are found the largest known deposits of nitrates in the world. 

The crude sodium nitrate is termed locally "caliche," and the "calicheras" are scattered over a large area which also contains beds of 

salt, "salares," and the deposits of ulexite which we have already 

considered. According to V. L'Olivier,4 the nitrates were first deposited, then the salt, generally to the westward of the calicheras, 

and finally the borates, which lie more to the east and in the higher 

levels of the evaporation basins. Some ulexite, however, is found in 

the nitrate beds. A characteristic calichera, in the Atacama Desert, 

50 miles west of Taltal, is described by J. Buchanan 5 as being made 

up of the following layers.

Section of typical calichera in Atacama Desert, Chile.

Ft. in.

1. Sand and gravel....................................... 1-2

2. "Chusca," a porous, earthly gypsum................... 6

3. A compact mass of earth and stones................... 2 -10

4. "Costra," a low-grade caliche, containing much sodium

chloride, feldspar, and earthly matter............... 1 - 3

5. "Caliche." (In the Tarapaca Desert it is from 4 to 12

feet thick).......................................... 1^- 2

6. "Coba," aclay....................................... ±3

The costra contains a considerable amount of bloedite; the rarer 

minerals, to be mentioned presently, are found in the caliche.

1 G. E. Bailey, Bull. No. 24, California State Mining Bureau, 1902, pp. 139-188.

s Op. cit., p. 170.

a The region was formerly a part of Peru and Bolivia.

< Annales chim. phys., 5th ser., vol. 7,1876, p. 289. For other details see D. Forbes, Quart; Jour. Geol. 

Soc., vol. 17,1861, p. 7; C. Ochscnius, Zeitschr. Deutsch. geol. Gesell., 1888, p. 153; and I'. Darapsky, Das 

Departement Taltal (Chile), Berlin, 1900. See also A. Pissis, Nitrate and guano deposits in the Desert 

of Atacama, London, 1878, published by authority of the Chilean Government. An earlier description 

of the nitrate field by J. W. Flagg is given in Am. Chemist, vol. 4, 1874, p. 403; and there is a recent important memoir by Semper and Michels, Zeitschr. Berg-, Hiitten- u. Salinenwesen preuss. St., 1904, pp. 

359-482. See also W. S. Tower, Min. and Sci. Press, vol. 107, 1913, p. 496, and W. H. Ross, Pop. Sci. 

Monthly, vol. 85, 1914, p. 134.

 Jour. Soc. Chem. Ind., vol. 12, 1893, p. 128. See also B. Simmersbach and F. Mayr, Zeitschr. prakt. 

Geologie, 1904, p. 273.
250 DATA OF GEOCHEMISTRY.

The composition of the caliche is very variable, as the following 

analyses, cited by R. A. F. Penrose, jr., show: 1

Analyses of caliche.

NaN08 ..............

KN03 .... ............

NaCl.. ...............

GaCl2 ................

MgCl3 ..... ...........

KC104 ...............

JX&£Ot .. ............

MgS04 ... ............

CaS04 ...............

Nas'BA-- -----------

Nal .................

NaI02 ...............

NH4 salts............

Na2Cr04 . .............

Insoluble.. ..........

H20, combined, etc. . .

A

28.54

Trace.

17.20

Trace.

5.40

3.43

2.67

.49

.047

.043

Trace.

40.30

1.88

100. 00

B

53.50

17.25

21.28

.78

1.93

1.35

.48

.56

.01

Trace.

Trace.

2.'07

.79

100.00

C

41.12

3.43

3.58

.75

Trace.

10.05

3.86

.20

.05

Trace.

31.86

5.00

100.00

D

61.97

5.15

27.55

.21

2.13

.15

.41

.43

.94

Trace.

Trace.

.39

.67

100. 00

E

22.73

1.65

41.90

Trace.

.94

3.13

4.80

.53

.07

Trace.

Trace.

22.50

1.75

100. 00

F

24.90

2.50

24.50

Trace.

6.50

6.50

4.50

.15

.054

Trace.

28.40

2.00

100. 00

G

27.08

1.34

8.95

5.25

.18

Trace.

None.

None.

2.89

.52

.08

Trace.

47.34

6.37

100. 00

 Anhydrite, gypsum, thenardite, mirabilite, bloedite, epsomite, 

glauberite, and salt are associated with the nitrates, and also the four 

following more unusual species:

Darapskite....................................NaN03 .Na2S04 .H20.

Nitroglauberite............................... GNaN03 .2Na2S04 .3E20.

Lautarite.....................................CaI206 .

Dietzeite....................................7CaI30G .8CaCr04 .

The lautarite and dietzeite are remarkable as the first definitely 

known iodates to be found in the mineral kingdom, although A. A. 

Hayes 2 reported sodium iodate as long ago as 1844. In dietzeite 

we have a compound of iodate and chromate which is analogous to 

some artificial salts but whose origin it is difficult to understand. 

Bromine is generally believed to be absent from nitrate beds, but 

A. Muntz 3 claims to have found it, in the form of bromates, in the 

mother liquors from which the saltpeter had crystallized out. Furthermore, in recent years considerable quantities of perchlorates, 

running in exceptional cases as high as 6.79 per cent of KC104 , have 

been discovered in Chilean nitrates.4 Finally, these nitrates always 

contain some borates, perceptible traces of rubidium and lithium,

1 Jour. Geology, vol. 18,1910, p. 14; D. G. Buchanan, analyst. For other analyses see L. Darapsky, Das 

Departemcnt Taltal, Berlin, 1900; A. Zfllarucllo, Anales Soc. cicnt. Argentina, vol. 68, p. 20; and F. W. 

Dalert. Monatsh. Chem., vol. 29,1908, p. 235.

$ See ante, p. 244.

s Annales chim. phys., 6th ser., vol. 11,1887, p. 121.

4 B. Sjollema, Chem. Zeitung, vol. 20,189G, p. 1002. As the perchlorates are believed to injure the nitrate 

as a fertilizer, a voluminous discussion over their detection and effects has appeared in the agricultural 

journals.
SALINE RESIDUES, - 251

but probably no caesium. 1 The borates may be small in amount, but 

it is doubtful whether they are ever quite absent.

The nitrate beds of South America are not entirely confined to 

Chile, although the Chilean deposits outrank all others in importance. The locality at Salinas Grandes, Argentina, has already been 

noticed in connection with its borates, and the niter there seems to 

be in entirely subordinate quantities. In the Argentine Territory 

of Santiago del Estero, according to W. F. Reid,2 there are salines 

which form crusts of salt during summer; and in the centers of the 

lagoons mother liquors exist from which" sodium nitrate is obtained. 

Zaracristi 3 has described another occurrence in the valley of the 

river San Sebastiano, in Colombia, where beds of sodium nitrate 

overlie a mixture of gypsum and calcareous clay, containing some 

oxide of iron and common salt. This deposit is very impure. An 

immense deposit of potassium nitrate, according to F. Sacc, 4 exists 

near Cochabamba, Bolivia, in direct association with borax. Sacc's 

analysis of a sample from this locality gives the following percentage 

composition of the salts:

Analysis of nitrate deposits near Cochabamba, Bolivia. 

KN03 ......................................................... 60. 70

N£uB407 ...................................................... 30. 70

NaCl.'........................................................ Trace.

H20......................................................... Trace.

Organic matter............................................... 8. GO

100. 00

The soil below the layer also contains borax. Sacc attributes the 

nitrates to the oxidation of ammonium salts -in the soil. The association of borates with potassium nitrate is especially noteworthy, and 

the locality ought to receive a more detailed examination.

No satisfactory explanation of the nitrate beds has yet been found, 

although many theories have been proposed to account for them. 

In addition to that of Forbes, already cited in relation to the borates, 

the following discussions of the subject are worth considering. C. 

Noellner, 5 who assumed a marine origin for the deposits, suggested 

that their nitrogen might be derived from decomposition of great 

masses of seaweeds; but this view has not been generally accepted. 

For example, the beds at Maricunga 6 are 3,800 meters above sea level 

and 180 miles from the coast, and other localities present similar 

difficulties of distance and elevation. The plain of Tamarugal,

1 L. Dieulafait, Coinpt. Rend., vol. 98,188-1, p. 1545.

2 Jour. Soc. Chem. Ind.,"vol. 19,1900, p. 414.

3 Berg. u. Hiittenrn. Zeitung, vol. 55,1890, p. 301. Two analyses aro given.

« Compt. Rend., vol. 99,1884, p. 84..

o Jour, prakt. Chemio, vol. 102,1867, p. 459.

« See E. Semper and M. Blanckenliorn, Zeitschr. prakt. GoDlogie, 1903, p. 309.
252 DATA OF GEOCHEMISTRY.

studied by W. Newton/ lies between the coast range and the Andes, 

3,000 feet above the sea, and the nitrate beds have peculiarities which 

seem to preclude either an oceanic origin or a derivation from guano. 

Here, at least, bromides are absent, and only traces of phosphates can 

be found. Sea water would yield the former; from guano the latter 

would remain. Newton regards the nitrates as originally formed by 

the oxidation of organic matter in alluvial soil. Tropical floods, 

which cover the plain once in every seven or eight years, bring upon 

it the concentrated fertility of thousands of square miles and sweep 

the deposits to the landward side of the coast chain, where they are 

mainly found. This is Newton's view, although he admits the possibility that electrically generated atmospheric nitrates may also be 

present. The same possibility is recognized by Semper and Blanckenhorn, but rejected by A. Muntz,2 who regards the electrical source as 

quite inadequate. Muntz accepts an organic origin for the nitrates, 

and argues that the calcium salt was first formed, as in the ordinary 

artificial process of nitrification. That compound then reacts with 

sodium chloride, forming calcium chloride and sodium nitrate, a 

transformation which he effected experimentally. The same result 

was also obtained later by A. Gautier, 3 who finds in guano the source 

of the nitrogen. The reaction is further suggested by the facts that 

the Chilean niter is always associated with salt, and that calcium 

chloride is found in the underground waters of the Pampas. Muntz 

also proved, by direct experiment, that iodides in a nitrifying mixture were oxidized to iodates; and from the absence of phosphates 

in the nitrate beds he infers that the nitrates have been transported 

in solution and redeposited at a distance from the original seat of 

their formation.

C. Ochsenius,4 who has written voluminously on the Chilean 

nitrates, regards them as derived from the mother liquors of salt 

deposits in the Andes. These are supposed to flow downward to the 

plains, their chlorides being partly converted to carbonates by carbonic acid of volcanic origin. The nitrogen is brought as ammoniacal 

dust from guano beds upon or near the seacoast, the heavier phosphatic particles being left behind. That such dust is carried by the 

winds is certain; but is it carried in sufficient amounts to account for 

large nitrate deposits far inland ? Another difficulty is suggested by 

Darapsky, who points out in his work on Taltal the comparative 

scarcity of carbonates in the nitrate regions. Even the waters of the 

Pampas contain little carbonic acid, and among the mineral springs

1 Jour. Soc. Chem. Ind., vol. 19,1900, p. 408. See also an earlier paper in Geol. Mag., 1896, p. 339.

2 Annaleschim. phys., 6th ser., vol. 11,1887, p. 111.

a Annales des mines, 9th ser., vol. 5,1894, p. 50.

aZeitschr. prakt. Geologie, 1893, p. 217; 1901, p. 237; 1904, p. 242. Zeitschr. Deutsch. geol. Gesell., 1888, 

p. 153. Ochsenius's work, Die Bildung des Natronsalpeters aus Mutterlaugensalzen, Stuttgart, 1887, I 

have not been able to see. His controversial papers, cited above, give a complete exposition of his views.
SALINE RESIDUES. 253

of Chile and Argentina carbonated waters are the exception rather 

than the rule.

Penrose,1 in his recent study of the nitrates, favors a marine origin 

for them, on the ground that the pampa, where the nitrate deposits 

occur, was once a part of the ocean bottom. Their nitrogen he 

derives from guano, and their iodine either from decomposing seaweeds or from mineral springs. The borates he ascribes to the 

decomposition of rocks containing boron-bearing minerals. The 

absence of bromides and the occurrence of nitrates at great elevations he does not try to explain.

Still more recently J. T. Singewald, jr. and B. L. Miller,2 from a 

study of the Tarapaca region, conclude that the nitrates are derived 

from the concentration by evaporation of the traces of these salts contained in the ground water. L. Sundt, on the other hand, points out 

the presence of nitrate beds on arid hilltops, where no ground water 

exists, and favors the atmospheric origin, through electrical agencies, 

of the nitric acid, which decomposes the feldspathic porphyrites that 

supply the alkaline base.

That the nitrate beds are proximately derived from the evaporation of saline waters is beyond doubt, but their marine origin, in 

light of what has been said, seems to be questionable. The ultimate 

source of their nitrogen is a more troublesome question and remains, 

so far, unsolved. The weight of opinion favors a derivation from 

organic matter, and from this point of view, Newton's explanation 

of the deposits is as satisfactory as any. Explanations of this order, 

however, are incomplete, for they take no account of the remarkable 

association of boron and nitrogen. Why do borates and ammonia 

occur together in volcanic waters, or borates and nitrates in the 

deposits of both Chile and California? This fact, which has already 

been emphasized, is surely not without significance, and it legitimizes 

the suspicion that the nitrates may be partly derived from volcanic 

sources. To be sure, this is only a suspicion, but it is one which 

ought not to be left out of account. Hot springs are common in 

the deserts of California and Nevada; they are also found along the 

volcanic Andean chain; do they contain boron and ammonia as a 

general rule, or only in sporadic instances ? Such waters, collecting 

in lagoons in the presence of some organic matter and the nitrifying 

organisms, would yield nitrates, and the latter would be found in 

the dried residues. A careful examination of all hot springs existing 

in the vicinity of nitrate beds is needed before we can decide how 

much weight can be given to this volcanic hypothesis.3 It may be 

discarded, but it should at least be thoroughly investigated.

> Jour, Geology, vol. 18,1910, p. 10.

a Econ. Geology, vol. 11,1916, p. 103. Followed in vol. 12,1917, p. 89, by a discussion with L. Sundt. See 

also A. H. Rogers and.H. R. Wagenen, Bull. Am. Inst. Min. Eng., Feb., 1918, p. 505, and C. DeKalb, Min. 

and Sci. Press, vol. 112,1916, p. 663.

8 According to T. Van Wagenen (Min. and Sci. Press, vol. 84,1902, p. 63), sodium nitrate is found in and 

around an extinct hot spring at the foot of the Humboldt Sink, Humboldt County, Nev.
254 DATA OF GEOCHEMISTEY,

THE ALUMS.

One more class of saline residues remains to be mentioned. Waters 

containing sulphates of iron or aluminum form deposits "of these 

salts, which may be neutral or basic, simple or complex. Their formation, however, is very local, and compounds of this character are 

rarely found far from their points of origin.

They are commonly derived, directly or indirectly, from the oxidation of sulphides, and occur as incrustations or even as stalactites, 

around mineral springs, or in the shafts or tunnels of mines. Acid 

solutions, produced by the oxidation of pyrite, act upon aluminous 

rocks and form sulphates of alumina. Alunite and alunogen are 

among the commoner species so generated. Alunogen and halotrichite, the latter a sulphate of aluminum and iron, are found in large 

quantities in Grant County, N. Mex.* Sulphates of iron of numerous species are especially abundant in the arid region of Chile. 

Sulphates of zinc, copper, cobalt, and nickel are deposited by mine 

waters. Some of the species thus developed will be considered in 

subsequent chapters, either in relation to the decomposition of rocks 

or in connection with the study of metallic ores.

i See C. W. Hayes, Bull. U. S. Geol. Survey No. 315,1907, p. 215. On alunogen in Colorado see W. r. 

Headden, Proc. Colorado Sci. Soc., vol. 8,1905, p. 62; also P. Termier on the derivation of alunite from 

feldspar, Bull. Soc. mm., vol. 31,1908, p. 215. W. Cross, Seventeenth Ann. Kept. U. S. Geol. Survey, pt. 2, 

1S9G, p. 314, and H. W. Turner, Am. Jour. Sci., 4th ser., vol. 5,1898, p. 424, have described quartz-alunito 

rocks. Onaluniteincrebodiessee F. L. Ransome, Econ. Geology, vol. 2,1907, p. 667. These occurrences 

are products of rock decomposition rather than residues from saline waters. On the remarkable vein of 

alunite at Marysvale, Utah, see B. S. Butler and H. S. Gale, Bull. TJ. S. Geol. Survey No. 511,1912.
CHAPTER VIII. 

VOLCANIC GASES AND SUBLIMATES.

* GASEOUS EMANATIONS.

j Regardless of all speculations as to the origin of the Hthosphere 

j or as to the nature of the earth's interior, we must recognize the fact

that some rocks were formed by the cooling of molten materials, and 

» we can study the phenomena of their development quite independ- 

> entry of cosmogonic hypotheses. Fluid magmas are seen to issue

from the earth and to solidify as lavas; they may be emitted quietly

-1 or with explosive violence, and they are accompanied by gaseous or 

vaporous emanations, which either escape into the air, are partially 

occluded by the cooling mass, or condense in the form of water.

*. Gases, water, mud, and fused or incandescent rocks are thrown out 

by volcanoes, and many of the attendant phenomena can be directly

' observed, or even reproduced in the laboratory. To the geophysicist

> the nature'of the volcanic forces is a prime subject of interest; chemistry concerns itself more with the nature of the products, and the 

latter theme is the one which demands attention now.

During a volcanic eruption the gaseous emanations are the first 

to appear, and their evolution continues more or less conspicuously 

until the discharge ends. Their emission does not cease even then, 

for gases" are given off from the cooling lavas, and also from the hot 

springs and solfataras which are formed in the course of the outbreak. These gases vary much in character, and in a single eruption 

they may present great differences in composition, changing from 

place to place and from time to time. For analysis they are com-

~ monly drawn from vents, crevices, or fumaroles at different distances from the center of activity, for the main crater itself is rarely 

accessible until after the eruptions have ceased. Furthermore, it is 

difficult to collect the gases quite free from admixtures of atmospheric air, and the samples analyzed are therefore, as a rule, impure. 

Still much is known concerning them, and many analyses of these

r* exhalations have been recorded.

It has long been held by nearly all authorities that water vapor or 

steam is the most abundant of the volcanic gases. The statement is 

generally accepted that it forms as much as 99 per cent of the entire 

gaseous output, but it soon condenses to liquid and is added or

restored to the hydrosphere. For instance, F. Fouque",1 observing

*>, _______________, 

i Sco A. Gcikie, Textbook of geology, 4th cd., p. 206. I have not boon able to find the original source of 

his citation.

255
256 DATA OF GEOCHEMISTRY.

one of the many parasitic cones on Etna, estimated that in one hundred days it discharged vapor equivalent to 2,100,000 cubic meters 

of water, or 462,000,000 imperial gallons. This great quantity is 

only a small fraction of what the entire volcano must have annually 

emitted, and its proximate origin may well be a subject for speculation. Is the water originally magmatic or only of surface origin; 

truly essential or merely extraneous ? On this theme there is active 

controversy, which will be considered in due order later.

The other volcanic gases, the term -"gas" being used in its ordinary significance, are hydrogen, oxygen, nitrogen, argon, helium, 

hydrogen sulphide, sulphur dioxide, carbon dioxide, carbon monoxide, 

hydrochloric acid, chlorine, methane, hydrofluoric acid, and silicon 

fluoride.1 Many other substances are found among volcanic exhalations and are deposited as sublimates around vents and fumaroles. 

Let us first consider the composition of the true gases, noting in 

advance that they were dried before analysis in order to eliminate 

the excess of water.

It is not necessary for our purposes to go any farther back in time 

than to the middle of the last century, when R. W. Bunsen published 

the results of his Icelandic researches.2 From among his analyses of 

volcanic gases the following examples are selected:

Analyses of volcanic gases from Iceland,

A. From a fumarolo in the great crater of Hekla. '*

B. From a fumarole in the lava of 1845, Hekla.

C. From the solfatara of Krisuvik.

D. From a fumarole a quarter of a league distant from Krisuvik.

E. From a group of fumaroles at Reykjalidh, in the extreme north of Iceland.

N

0,.. .......... ........................

H2 .... ...... ..........................

C0a ..................................

H2S........... ........................

SO....................................

A

81.81

14.21

2.44

^Tnno

1.54

100. 00

B

78 QO

20.09

1.01

100. 00

0

1.67

4.30

87.43

6.60

100. 00

D

0.50

4.72

79 07

15.71

100. 00

E

0.72

25.14

50.00

24.12

99.98

The water condensed from the fumaroles of Hekla carried a little 

hydrochloric acid, but in amounts too small for determination.

1 The two fluorine compounds are reported by A. Scacchl from Vesuvius, Catalogo del minerali Vesuviani, Naples, 1887. See also E. S. Dana, System of mineralogy, 6th ed., p. 169. According to A. Gautier 

(Compt. Rend., vol. 157,1913, p. 820), volcanic gases generally contain fluorine compounds. In a gas from 

Vesuvius he found 0.110 milligram of F per liter. In a sublimate from the volcano Chinyero, Canary 

Islands, A. del Campo (Jour. Chem. Soc., vol. 104, ii, 1913, p. 145) found ammonium fluoride.

2 Annales chim. phys., 3d ser., vol. 38,1853, p. 215. For these analyses and others, see pp. 260-2G6. An 

earlier, classicalmemoir by Elie de Beaumont, entitled " Emanations volcaniques etme'tallifercs," appeared 

in Bull. Soc. geol. France, 2d ser., vol. 4,1847, p. 1249. An important article on the gases of the hot springs 

of Iceland and their radioactivity, by T. Thorkelsson, is in the Memoirs of the Danish Acad. 7th ser., 

vol. 8,1910, p. 181.
VOLCANIC GASES AND SUBLIMATES. 257

Among the sublimates formed by these fumaroles, Bunsen noted 

sulphur and various metallic chlorides, especially common salt. One 

sublimate, however, contained 81.68 per cent of ammonium chloride. 

. Because of their accessibility the Italian volcanoes have been 

studied with peculiar thoroughness, and with regard to their gaseous 

exhalations the data are most abundant. In 1856 C. Sainte-Claire 

Deville * published a description of the fumaroles found on Vesuvius 

during the eruption of 1855, which he classified in the order of diminishing volcanic intensity. The classes proposed are as follows:

1. Dry fumaroles. Sublimates of metallic chlorides, with traces of sulphates. 

Sometimes fluorides are formed, as observed by Scacchi on the lava of 1850. These 

fumarolea are emitted directly from incandescent lava, and the subliming vapors are 

mixed with a gas which is essentially atmospheric air. A special group of dry fumaroles emit ammonium chloride.

2. Acid fumaroles. Water vapor, mixed with hydrochloric and sulphurous acids. 

Commonly accompanied by chlorides of iron and copper, which are deposited around 

the vents. The vents occur on lava, either in the main crater or along the fissure of 

eruption. The hydrochloric acid is very largely in excess of the sulphurous.

3. Fumaroles emitting water vapor containing hydrogen sulphide or free sulphur. 

Their temperature rarely exceeds 80°.

4. Mofettes. Emissions of water vapor with carbon dioxide. These appear where 

the volcanic intensity has become very slight.

5. Fumaroles emitting water vapor alone.

- Although, as we shall see later, this classification is incomplete, it 

serves a useful purpose in giving a rough outline of the phenomena. 

At the point of greatest activity dry.vapors appear; farther away, 

or as cooling progresses, acids are formed, and emanations of carbon 

dioxide mark the dying out of the volcanic energy. But there are 

fumaroles, like some of those in Iceland, which do not fall in any 

one of these classes, - ^- "r-v -.,j./x.

In 1858 C. Sainte-Claire Deville and F. Leblanc 2 published their 

analyses of volcanic gases, not only from Vesuvius, but also from 

Vulcano, Etna, and other localities. A fumarole in the crater of 

Vesuvius, emitting a gas of extremely suffocating odor, yielded hydrochloric acid and sulphur dioxide in the ratio of 86.2 : 13.8. The 

bulk of the gas, after removal of these substances and water, was 

essentially atmospheric air slightly impoverished in oxygen. Other 

Vesuvian fumaroles also emitted similar air, with small but variable admixtures of sulphur dioxide, hydrogen sulphide, and carbon 

dioxide. Sulphur dioxide and carbon dioxide, however, were mutually exclusive and never occurred together. The emanations from 

Etna resembled those from Vesuvius.

i Bull. Soc. g<5ol. France, 2d scr., vol. 13,1855-56, p. COG; vol. 14, 1856-57, p. 254. 

a Annales chim. phys., 3d ser., vol. 52,1858, p. 5.

113750° 19 Bull. 695 17
258 DATA OF GEOCHEMISTRY.

At Vulcano Deville and Leblanc made a-number of striking .observations, which are well illustrated by the following selected analyses:

Analyses of gases from Vulcano.

A. Gas from the crater issuing at a temperature above the melting point of lead. This fumarole deposits 

boric acid. The gas was collected from a vent which emitted flames. 

B. A gas similar to the foregoing, but not accompanied by boric acid. 

C. Sulphurous fumarole from the north flank of Vulcano.

D. Gas from a cavity, filled with hot water, known as ' 'Acqua-Bollente," and situated near the seashore, 

E. Gas from depressions still farther from the crater, collected over water having a temperature of 25° C.

co2 ..................................

soa ........ ............................ H2s.. ..........;.................:..

02 ............ .......................

N

A

None.

39. 13

10.10

50.77

100. 00

B

. None.

27.50

14.02

58.48

100. 00

c

None.

69; 6

5.5

94 Q

100.0

D

6.4

83,1

.7

9.8

100.0

T?

86.0

IS! rmp

14.0

100.0

These analyses show very well the progressive change in the fumaroles as they.recede from the eruptive centert At the end of their 

memoir Deville and Leblanc give analyses of gases emitted from 

various springs in Sicily which have some relations to the volcanic 

activity of Etna. Some of them give off mainly carbon dioxide; 

others yield methane, CH4 , in considerable quantities. A few analyses 

will illustrate the character of these exhalations.

Analyses of gases from Sicilian springs.

A. From the Lake of Palici. B. From the Salinelle of Paterno. C. From the Macaluba do Xirbi. 

D. From the Macaluba do Girgenti.

rn

oa .. ...........................................

Np-fr

A

94.70

1.10

3.52

.68

100. 00

- B

90.7

1.0

o q

5.0

100.0

c

0.70

5.17

9fl 4fl

73.73

100. 00

j>

1 "K

1.70

6 7^

90.40

100. 00

The conclusion finally stated by Deville and Leblanc is as follows; 

The nature of the emanations from a given point varies with the time 

which has elapsed since the beginning of the eruption: thefumaroles 

at different points vary with their distance from the volcanic center. 

In both cases the order of variation is the same.

In 1865 F. Fouque" * studied the Italian field with special reference 

to the exhaled gases. In the crater of Vulcano he examined three 

fumaroles, at different temperatures, with results as follows:

i Compt. Tlend., vol. 61,.1865, pp. 210, 421, 564, 754..
VOLCANIC GASES AND SUBLIMATES. 259

Analyses of gases from fumaroles, Vulcano. 

A. Temperature above 350°. B. Temperature 250°. C. Temperature 150°.

0

HCI+SO,. ............................................. co,.....r.............................................

o2 .:...... .............................................

"

A

73.80

23.40

.52

2.28

100. 00

B

66.00

22.00

2.40

9.60

100. 00

C

27.19

59.62

10 QQ

100. 00

Iii these gases the hydrochloric acid was most abundant, the sulphur dioxide being almost negligible. Around the vents realgar, 

ferric chloride, and ammonium chloride were deposited. Another 

group of fumaroles, at a temperature of 100°, gave deposits of sulphur, sometimes with and sometimes without boric acid. Their 

composition is given below, under D and E.

Analyses of gases from fumaroles, 'Vulcano. '

/

HC1. ..................................................

Ha S....................................................

coa ................................................... o2 .. ...................................................

N2 ... ...... ...........................................

.D

7.3

10.7

68.8

2.7

 11.2

a 100. 7

E

Trace.

63.59

7.28

29. 13

100. 00

F

17.55

77.02

.70

4 7°.

100. 00

o This summation suggests a misprint somewhere in the original column of figures.

Analysis F represents gas from the fumarole known as "AcquaBollente," which was examined by Deville and Leblanc nine years 

earlier. The loss of hydrogen sulphide and the gain of carbon 

dioxide during that period are most striking and show a decrease of 

volcanic activity.1 The temperature of the fumarole is given as 

86° C. FouquS's analyses of gases from two small solfataras at 

Pozzuoli, near Vesuvius, also indicate a relationship between composition and temperature.

Analyses of gases from Pozzuoli.

 E^..........:.^........ ........................................

coa .. ..................................................:.

oa ........ ...............................................

N........ ..............................................

G (temperature 96°).

11. 43"

56. 67

5.72

26.18

100. 00

H (temperature 77.5°).

None

15.09

15. 51

69.40

100. 00

1 Ece note by Doville, Compt. Rend., vol. 01,1865, p. 567. For recent analyses of gases from Italian volcanic sources, see R. Nasini, F. AnderUni, and R. Salvador!, Gazz. chim. ital., vol. 36, fasc. 1,1906, p. 429.
260 DATA OF GEOCHEMISTRY.

An elaborate examination of the gases emitted by Etna during several eruptions led 0. Silvestri * to conclusions much like those reached 

by Deville and Leblahc, and he describes fumaroles of several classes, 

representing a progressive diminution of volcanic intensity. The 

data may be briefly summarized as follows:

1. The fresh, still flowing lava acts like one great fumarole, and emits from its surface white fumes. These are partly condensible, yielding a solid saline residue and 

a small amount of liquid containing free hydrochloric and sulphurous acids. The 

incondensible gas, as in the cases previously noted, is essentially atmospheric air 

slightly deficient in oxygen. One sample, upon analysis, gave 02 , 18.79 per cent; 

N2 , 81.21 per cent. The white residue contained chiefly sodium chloride and carbonate, and three deposits collected from the surface of the lava had the composition 

shown in'the subjoined table. As the lava cools, the exhalations become localized 

and change their character with decreasing temperature.

Analyses of deposits from surface of lava.

NaCl. ................................................

KCL. .......................... <......................

NaaCOa. ..............................................

Na^SCV ...............................................

IT20. ..................................................

50.19

.50

11.12

113

30.76

100. 00

63.02

.27

6.49

Trace.

on 99

100. 00

76.01

.03

2.11

7C

21.10

100. 00

Tn some cases the fumes also contain copper chloride, which forms, on the lava, 

deposits of atacamite and.tenorite, the latter, obviously, by oxidation.

2. Ammonium-chloride fumaroles, which are divided into two subclasses. First, 

acid fumaroles, which form mostly upon the terminal walla of the lava stream and 

emit much hydrochloric acid. They also contain ferric chloride, which is partly condensed as such and partly oxidized, to hematite. Aa the temperature falls they 

develop hydrogen sulphide and deposit crystals of sulphur. Seqond, alkaline fumaroles, which are free from hydrochloric acid and ferric chloride and deposit only 

ammonium chloride. They represent a lower temperature than the acid type. The 

gaseous portion of these exhalations, acid or alkaline, is still essentially air, containing from 81.19 to 84.17 per cent of nitrogen.

3. Water fumaroles, which give off only water vapor, mixed with impoverished air. 

Temperature relatively low.

4. Fumaroles emitting water vapor and carbon dioxide, the last phase of activity. 

The gases from two of three fumaroles in the crater of Etna, analyzed by Silvestri, 

had the following composition:

Analyses of fumarole gases from Mount Etna.

N... ....................................................... oj.. ......................................................

COo .......

H Q

77.28

17.27

5.00

.45

100. 00

79.07

IS Q7

1.61

.35

100. 00

11 fenomeni vulcanic! presentati dell' Etna, etc., Catania, 1867. The data here given are from an abstract 

by G. vom Hath, Netios Jahrb., 1870, pp. 51,257. See also the great monograph, "Der Aetna," by Sartorius von Waltershausen and A. voa Lasaulx, 2 vols., Leipzig, 1880. On the exhalations of Etna see also 

I. G. Ponte, Atti E. accad. Lincei, vol. 23, pt. 2,-1914, p. 341.
VOLCANIC GASES AND SUBLIMATES. 261

' Although the observations made by T. Wolf 1 at Cotopaxi were 

only qualitative, they confirm the belief that a regular order exists 

in the composition of volcanic exhalations. Near the crater the fumes 

of hydrochloric acid were overwhelming and there was a suspicion 

of free chlorine. At lower levels on the mountain hydrogen sulphide 

was recognized, and occasionally sulphur dioxide. The order, so far 

as it was studied, is the same as that noted in the volcanoes of the 

Mediterranean.

In his great monograph on the volcanic eruptions of Santorin,2 

F. Fouque" discusses at some length the gaseous emanations, in which, 

as in the Icelandic craters, free hydrogen appeared, and also small 

quantities of hydrocarbons. The great eruption of Nea Kame'ni, one 

of the islands of the archipelago, began in January, 1866, and some 

of the gases analyzed were collected in March. For the first tune 

hydrogen and marsh gas were taken from an active volcano in the 

presence of true volcanic flames, and it was shown beyond reasonable 

doubt that in the central fires water had been dissociated into its 

elements. Ordinarily the combustible gases are burned as soon as 

they reach the air, but the peculiar conditions prevailing at Santorin 

permitted their accumulation unchanged and rendered their complete 

identification possible. The subjoined analyses represent mixtures 

containing gases of this class:

Analyses of volcanic gases from Santorin.

A. Gas collected on Nea Kame'ni, March 17,1866, from the surface of sulphurous water in a fissure between Giorgios and Aphroessa, temperature 78°. Three other similar analyses are tabulated with this. 

B. From the same fissure on Nea Kame'ni, temperature 69°. Collected March 25, I860. 

C. Gas collected March 7, 1867j over sea water, near the end of a still incandescent lava stream 

D. Occurrence similar to C, but from a different stream. Taken March 5,1867.

HaS...........................................

C0a .. ........................................

Ho............................................

CH4 ..........................................

0».............. '.............................. N;. ..........................................

A

36.42

29.43

.86

.32

32.97

100. 00

B

Trace.

50.41

16.12

2.95

.20

30.32

100. 00

C

0.22

56.70

.07

21.11

21.90

100. 00

D

None

1.94

i fin

a24.94

72.12

100. 00

a 25.94 in table, but corrected in list of errata at the end of the volume.

Gas C was a true explosive mixture, which detonated violently upon 

contact with a flame. In collecting it special care was taken to avoid 

an admixture of air; its oxygen, therefore, is not from extraneous 

sources. It is possible, however, that both the oxygen and the hydrogen in this instance came from the decomposition of sea water in 

contact with hot lava, although Fouque believed that they were presNeues Jahrb., 1878, p. 163- 2 Santorin et scs eruptions, Paris, 1879
262 DATA OF GEOCHEMISTRY.

ent in the molten stream. In 1866 the largest proportions of hydrogen 

were found in gases taken from the principal fissures of the eruption, 

and they diminished in quantity with the distance of their points of 

issue from the focus of activity. A precisely similar diminution 

follows the lapse of time, as shown by analyses A and B of gases from 

the same locality, but collected eight days apart.

Gases collected in May, 1866, and some taken at greater distances 

from the center of eruption consisted either of carbon dioxide or of 

atmospheric air which had been entangled in the lavas. Some were 

heavily loaded with water vapor, which, when condensed and oxidized by nitric acid, gave a solution containing hydrochloric and 

sulphuric acids, the former, as in the instances previously cited, being 

largely in excess of the latter. Several of the dried gases had the 

composition shown in the subjoined table.

Analyses of volcanic gases from Santorin,

A. Gas taken May 4,1866, from the bottom of a fissure en Nca Kam6ni. Collected over sulphurous water, 

at temperature £0°.

B. Collected May 12,1866, at the foot of the cone Giorgios, from a small fumarole surrounded by crystals 

of sulphur. Temperature 87°.

C. Like B and near it, the sulphur partly crystallized and partly fused. Temperature 122°.

D. Gas from periphery qf eruptive field, March, 18C7.

E. Gas collected near the port of St. George of Nea Kam6ni, March 9,1SG7.

H2S................ :.........-..-...

co2 ... ...... .........................

03 ..:... ..............................

N2 ...... ........... ............. ,...-..

CH4 .. ................................

- A

Trace.

95.37

.49

4.14

100. 00

B

0.42

5.88

18.99

74.71

100. 00

C

0.90

12.24

16.41

70.45

100. 00

D

NoD.6

20.62

79.38

100. 00

E

56.63

1.84

41.41

.12

100. 00

These analyses all tell the same story as that given by the Italian 

investigations; carbon dioxide appears as the volcanic .intensity dies 

away; only at Santorin the maximum of activity is represented by 

hydrogen, and the acid products were.less completely examined.

For other volcanic regions the data relative to gaseous exhalations 

are not so complete. Three analyses by H. Moissan 1 of gases from 

West Indian fumaroles are, however, especially interesting on account 

of the determinations of argon.2 The analyses are as follows:

i Compt. Bend., vol, 135,1902, p. 1085; vol. 138, 1904, p. 930. . For details relative to these fumaroles and 

other volcanic emanations, see the monographs by A..Lacroix, La Montagne Pejee et ses eruptions, Paris, 

1904. F. Fouque, Compt. Eend., vol. 66,1868, p. 915, analyzed gases from a submarine eruption near the 

Azores. H. Corceix (idem, vol. 75,1872, pp. 154,270: vol. 78,1874, p. 1309) examined gases from Vesuvius, 

Santorin, and Nisyros; gases from St. Paul Island were studied by C. Velain, idem, vol. 81, 1872, p. 332. 

A paper by TV. Hcmpel on volcanic gases is in Zeitschr. Vulkanologie, vol. 1.1914, p. 153:

! Argon and helium have been detected in the 'gases from the boric fumaroles of Tuscany by C. Porlezza 

and G. Norzi, Atti R. accad. Lincei, vol. 20,1911, p. 338.
VOLCANIC GASES AND SUBLIMATES. 263

Analyses of gases from-West Indian fumaroles.

0.

A. From a fumarole on Mont Pclee, Martinique. Gas collected by Lacroix after the great eruption of 

May, 1G02. Temperature about 400°. Gas at first saturated with steam. Around this vent ammonium 

chloride and sulphur were deposited.

B. From the Fumarole du Nord, Guadeloupe.

C. From the Fumarole Napoleon, Guadeloupe.

Gases A and B, previous to analysis, were both saturated with water.

\

C02 . .................:................................

co...................................................

CH4 .. .................................................

H2 . ...............................................:..

oa .. ...............................................

?a - .................................................. 

A.....................................................

HC1. ..................................................

HoS. .................................................

S, vapor. ..............................................

A

15.38

1.60

5.46

8.12

13.67

54 04

.71

Trace.

Trace.

99.88

B

52.8

None.

None.

None.

7.5

36.07

.73

2.7

99. 80

C

69.5

None.

None.

2.7

99 Q9

.68

4.5

Trace.

99. 70

Here the recent gas is noticeably charged with combustible substances, the lower activity of Guadeloupe being shown by their 

absence and by the larger quantities of carbon dioxide. Carbon monoxide appears in the Mont Pelee emanation, which emphasizes the 

observations made by W. Libbey * on Kilauea. He, by spectroscopic 

study of the volcanic flames, found that hydrogen, carbon monoxide,, 

and hydrocarbons were probably present. Hydrogen had been simiaiiy observed by J. Janssen 2 much earlier namely, in volcanic 

flames at Santorin in 1867, and at Kilauea in 1883. The spectral lines 

of sodium, copper, chlorine, and carbon compounds were also seen.

Much more fundamental work on Kilauea was done by A. L. Day 

and E. S. Shepherd,3 who spent several months on the volcano during 

1912. They not only determined the temperature of the molten lava 

in situ, but also collected the volcanic gases directly from an active 

cone. An iron tube was passed through the thin wall of the cone into 

the liquid lava, and connected externally with a train of glass tubes 

through which the gases were drawn by pumping. In the tubes at the 

beginning of the train 300 cubic centimeters of water were condensed 

in about 15 minutes; this water and the attendant gases were afterward analyzed. The water contained various saline substances, 

partly perhaps derived from the glass, but notable quantities of 

fluorine, chlorine, and sulphur dioxide were also determined. The.

1 Am. Jour. Sci., 3d ser., vol. 47,1894, p. 372.

2 Compt. Rend., vol. 64,1867, p. 1303; vol. 97,1883, p. 601.

3 Bull. Geol. Soc. America, vol. 24,1913, p. 573. See rejoinder by Brun, Arch. sd. ptiys'. nat., 4th ser., 

vol. 41,1916; p. 401.
.264 DATA OF GEOCHEMISTRY.

dried gases from five of the tubes had the following composition by

volume:

Analyses of gases from Kilauea.

C02 .............................:....

co........................:...........

H2 ..>....... ...........................

N

so2 .. ................................

23.8

5.6

7.2

63.3

None.

99.9

58.0

3.9

6.7

29.8.

1.5

99.9

62.3

3.5

7.5

13.8

12.8

99.9

59.2

4.6

7.0

29.2

None.

100.0

73.9

4.0

10.2

11.8

None.

99.9

 No chlorine was found in these gases and no argon, the latter fact 

proving that there was no admixture of atmospheric air. The gases 

were truly magmatic. -The significance of these observations will 

appear later in relation to the researches of Brun. The abundance of 

water in the molten lava was definitely established.

SUBLIMATES.

It has already been remarked that the gases issuing from a volcano 

are often if not-alwa3rs accompanied by substances which are gaseous 

only at high temperatures and are deposited, upon cooling, in solid 

form. These sublimates, as they are called, are of many different 

kinds, and it is sometimes difficult to determine whether a given 

example is a true sublimation or is produced by secondary changes. 

To discriminate between the products of direct condensation from 

vapor and substances due to the action of the gases upon lava is not 

always easy. Some of the so-called sublimates are nonexistent at 

high temperatures, and are formed only upon cooling;1 others result 

from decompositions of volatile matter; and still others are generated 

by-reactions between different gases. For example, sulphur may be 

directly sublimed; it may be formed by the decomposition of hydrogen sulphide or by the partial oxidation of that compound; and it is 

precipitated from mixtures of hydrogen sulphide and sulphur dioxide, 

two compounds which can not exist together. When they are commingled, sulphur is set free. By either of these processes volcanic 

sulphur can be deposited; but only the first is strictly a sublimation; 

that is, the volatilization and recondensation of a substance without 

chemical change. It is perhaps permissible, however, to use the term 

sublimate a little more loosely, for rigidly accurate discrimination is 

not practicable in the present instance. Any solid, then, deposited by or from volcanic gases, may be regarded conventionally as a 

sublimate.2

1 For example, ammonium chloride, which when vaporized is dissociated into NHs+HCl.

2 On the conditions under which different modifications of sulphur are deposited around volcanoes see 

A. Brun, Chem. Zeitung, No. 15,1909. Brun holds that the H2S, SO2 reaction does not take place in solfataras; but Y. Oinouye (Jour. Geology, vol. 24,1916, p. 806), has described a solfataric crater lake on one of 

the Kurile Islands, in which, by this process, sulphur is deposited in large quantities.
VOLCANIC GASES AND SUBLIMATES. ' 265

The most conspicuous of all the volcanic sublimation products is 

undoubtedly native sulphur. It is found in or near all active volcanic 

craters, and it often contains appreciable quantities of selenium, as 

in the well-known selensulphur of the Lipari Islands. Tellurium has 

been found in Japanese sulphur,1 to the extent of 0.17 per cent; and 

A. Cossa 2 reports it as present in some of the soluble salts which are 

formed stalactitically in the crater of Vulcano. The last-named 

locality has been studied with more than ordinary thoroughness, and 

among its fumarole deposits, which are partly sublimates and partly 

secondary products, A. Bergeat 3 names realgar, boric acid, sodium 

chloride, ammonium chloride,4 ferric chloride, glauberite, lithium 

sulphate, sodium sulphate, alum,5 hieratite,6 and compounds of cobalt, 

zinc, tin, bismuth, lead, copper, and phosphorus. The chlorides 

named in this list are commonly found in volcanic craters, and the 

chlorides of potassium, calcium, magnesium, ferrous'iron, manganese, 

lead, and aluminum have also been observed.

At Vesuvius A. Lacroix7 found large crystals of potassium chloride 

and other crystals consisting of a double chloride of potassium and 

manganese. Mixed chlorides of sodium and potassium are reported 

by E. Casoria8 and G. Freda.9 These salts, however, are interpreted 

by F. Henrich 10 as secondary, formed by the action of moisture and 

hydrochloric acid on the alkaline silicates .of the heated lavas. From 

ferric chloride the rare minerals kremersite, KNH4FeCl5 .H20, and 

erythrosiderite, K2FeCl5 , are derived, and also hematite; while copper 

chloride yields the oxide, tenorite; chlorothionite,K2S04 .CuCl2 ; dolerophanite, Cu2S05 ; and cyanochroite, K2Cu(S04) 2 .6H2 0; with some 

hydrous chlorides and oxychlorides. Even manganese is found in 

the mineral chlormanganokalite, K4MnCl6, discovered by H. J. 

Johnston-Lavis. 11 The simple anhydrous chlorides are the true sublimates; the other compounds are generated from them by secondary 

reactions. From the fluorine gases, we get hieratite, ammonium 

silicofluoride, rarely fluorspar, and the oxyfluoride of calcium and 

magnesium, nocerite. Most of these substances were first described

1 E. Divers and T. Shimidzu, Chem. News, vol. 48,1883, p. 284.

2 Zeitschr. anorg. Chemie, vol. 17,1898, p. 205.

3 Die Aeolischen Inseln: Abhandl. Math.-phys. Classe, K. bayer. Akad., vol. 20, Abth. 1,1899, p. 193.

* Containing, according to Deville and Leblanc (Annales chim. phys., 3d ser., vol. 52,1858, p. 5), also 

iodide.

6 Potash alum, containing cajsium, rubidium, and thallium. A. Cossa, Atti R. accad. Lincei, 1878, pt. 

2,p. 34. . '

«Potassium silicofluoride, K2SiF6 . A. Cossa, Compt. Rend., vol. 94,1882, p. 457.

' Compt. Rend., vol. 142,1906, p. 1249. See also H. J. Johnston-Lavis, Nature, May 31,1906. In Bull. 

Soc. min., vol. 30,1907, p. 219, Lacroix has described the minerals'of the Vesuvian fumaroles in considerable detail.

s Abstract in Zeitschr. Kryst. Min., vol. 41,1906, p. 276. Casoria found molybdenum, bismuth, copper, 

and zinc in \resuvian salts. The presence of boron, lithium, lead, and thallium in volcanic exhalations has 

been described by A. Bran, Arch. sci. phys. nat., 4th ser., vol. 44,1917, p. 5.

s Gazz. chim. ital., vol. 19,1888, p. 16.

10 Zeitschr. angew. Chemie, vol. 19,1906, p. 326; vol. 20,1907, p. 179.

" Mineralog. Mag., vol. 15,1908, p. 54. - . -
266 DATA OF GEOCHEMISTRY.

from Vesuvius, and we owe our-knowledge-of them to the indefatigable 

labors of A. Scacchi, who has also described many sulphates, simple, 

double, or basic, which are formed by the action of solfataric vapors 

upon the surrounding rocks. Similar sulphates, of sodium, potassium, 

calcium, magnesium, and aluminum, were found by A*, Lacroix1 

among the fumarole products of Mont Pele"e. Sodium carbonate is 

also produced in a secondary way. The sublimates from the volcano 

Quetzaltepec, San Salvador, also described by Lacrpix,2 consist 

largely of ammonium sulphate and chloride, with a little sodium 

chloride. An incrustation on volcanic ash collected by E. T. Alien3 

on che top of Lassen Peak, California, consisted mainly of sulphates 

with about 9 per cent of pentathionates and perhaps a little tetrathionate. The formation of these salts must have been due to the 

well-known reaction between H2S and S02 , which yields the corresponding acids. Silver was discovered by J. W. Mallet 4 in volcanic 

ash from Cotopaxi and Tunguragua; and it is quite probable that 

this metal, which volatilizes readily, was ejected as vapor. Silver 

begins to vaporize not much above its melting point, and at the temperature of the oxyhydrogen flame it can be distilled easily. Sulphides have been'found as'sublimation products at Vesuvius, formed 

perhaps by the action of hydrogen sulphide upon volatilized metallic 

chlorides. A. Lacroix5 and F. Zambonini 6 both report galena 

among the substances produced during the eruption of April, 1906, 

and Lacroix mentions pyrite and pyrrhotite also.

At the volcano La Sufralin Colombia the sulphur sublimed in the 

steam which periodically fills the crater contains gold.7

The ammonium salts found in volcainic emanations were partially 

considered in the preceding pages. They are very common, but their 

significance has been variously interpreted. Some writers have 

argued that then' nitrogen is derived from organic matter, such as 

vegetation, with which the flowing lava has come into contact an 

opinion which is not well sustained. 0. Silvestri,8 in 1875, found 

silvery incrustations of an iron nitride, Fe5N3 , on an Etna lava, and 

conducted a series of experiments to determine its origin. Fragments 

of lava were first heated in gaseous hydrochloric acid, when water 

was expelled, silica was liberated, and chlorides of iron were formed.

1 Bull. Soc. miii., vol. 28,1905, p. 60. Lacroix (Compt. Rend., vol. 144,1907. p. 1397) has also discovered a double sulphate of potassium and lead among the fumarole products of Vesuvius. This new 

mineral is named palmierite.

2 Compt. Rend., vol. 165,1917, p. 1077.

3 Private communication. Cf. also J. S. Maclaurin, ante, p.. 195.

« Proc. Roy. Soc., vol. 42,1887, p. 1; vol. 47,1889-90, p. 277.

c Compt. Rend., vol. 143,1906, p. 727. 

6 Idem, p. 921: In Zambonini's great monograph, Mineralogia Vesuviana, published by the Naples 

Academy in 1910, full details are given of each species found at Vesuvius, together with thorough bibliographic references. On the minerals and sublimates of Vulcano, see 0. de Fiore, Zeitschr. Vulkanologie, 

vol. 2,1915, p. 12, and U. Paniche, Mem. Soc. ital. scienze, Hz. e nat., vol. 19,1916, p. 3.

i See W. H. Goodchild, Mining Mag., Oct., 1918.

8 Gazz. chim. ital., vol. 5,1875, p. 301; Pogg. Annalen, vol. 157,1876, p. 165. Silvestri's results have been 

questioned and need confirmation.
VOLCANIC GASES AND SUBLIMATES. 267

Subsequent heating of the mass in a stream of ammonia formed 

hydrochloric acid again, together with ammonium chloride, hydrogen, 

and a nitride of iron. Ammonium chloride, acting on lava at a red 

heat, gave similar products. Ammonia alone, passed over heated 

lava, was decomposed, yielding a gas containing 90 per cent of hydrogen, while a large part of its nitrogen wag absorbed.

On the other hand, it is well known that when metallic nitrides are 

heated in steam, ammonia is formed. We have, therefore, something 

like a group of reversible reactions to deal with, not strictly reversible 

perhaps, but of such a character as to render it uncertain which compound, nitride or ammonia, existed first. Either substance can be 

generated from the other. J. Stoklasa, 1 however, regards it as possible that nitrides, formed deep within the earth, are the initial compounds. At all events, he has clearly shown that the nitrogen of lava. 

is an original constituent, and not of organic origin. In all of the 

lavas ejected by Vesuvius during the eruption of 1906 ammonium 

compounds were found, the largest amount, 300 milligrams of NH3 

per kilogram, being extracted from an oh'vine bomb. The watersoluble portion of the lapilli contained 33 per cent of ammonium 

chloride. Organic contamination, in the samples of lava examined, 

was impossible. An alternative hypothesis, framed to account for 

the volcanic ammonia, is that of 0. Rosenbach, 2 who argues that it 

may be generated by reactions between atmospheric nitrogen and 

hot lava, in presence of moisture and hydrochloric acid. This suggestion is supported by very little evidence and needs experimental 

verification. . .

It is difficult to assign any limit to the possibilities of sublima^ 

tion within the vent of an active volcano. Given a temperature 

sufficiently high, and almost any mineral matter may be volatilized 

or decomposed into volatile constituents. In the electric furnace, 

H. Moissan 3 has vaporized alumina, lime, magnesia, silica, zirconia, 

and titanic oxide, and these substances are all found in volcanic rocks. 

The oxides of the iron group are more stable, and fuse but do not seem 

to distill. According to these observations, alumina volatilizes most 

easily, lime quite easily, and magnesia with less facility. P. Schutzcnberger 4 has observed that silica gradually loses weight in a good wind 

furnace, whose temperature is far below that of the electric arc; and 

E. Cramer 5 has completely vaporized rock crystal under similar conditions. Cramer used a Deville furnace, with gas carbon or retort 

graphite for fuel, with a blast of air; and in one experiment 4.517

1 Ber. Deutscli. chem. Gesell., vol. 39,1906, p. 3530; Cfaem. Zeitung, vol. 30,'10C6, p. 740; Centralbl. Mtn., 

Geol. .u. Pal., 1907, p. 161. See also R. V. Matteucci, Oentralbl. Miu., Ceol. u. Pal., 1901, p. 45, on an* 

moniuia chloride in the crater of Vesuvius.

2 Natur. Wochenschr., vol. 21,1906, p. 740.

3 Le Jaur <51ectrique, pp. 32-49, Paris, 1897. Sea also Compt. Rer cl., vol. 116,1S93, p. 1222.

« Compt. Rond., vol. 116,1S93, p. 1230.

GZeitschr. angow. Cheuiio, 1892, p. 481. , ...
26-8. DATA OF GEOCHEMISTRY. :

grams of quartz were evaporated. At the temperature of melting 

cast iron, quartz was stable and lost no weight; although Moissan* 

has observed that at 1,200° G. silica appears to have an. appreciable 

tension. According to A. L. Day and E. S. Shepherd,2 quartz vaporizes rapidly in air at about the temperature of melting platinum. 

Silica, then, is volatile at temperatures which are probably reached 

or exceeded within the volcanic reservoirs; and it may appear among 

the products of sublimation. In fact, quartz, tridymite, and various 

silicates have been repeatedly observed in lavas under conditions 

which indicated an origin of this kind. A. Scacchi, 3 for example, 

reports leucite, augite, hornblende, mica, sodalite, microsommite, 

cavolinite, garnet, and possibly sanidine and vesuvianite as formed 

by sublimation at Vesuvius. Furthermore, experiments conducted 

by A. L. Day and E. T. Alien in the laboratory of the United 

States Geological Survey have shown that feldspars can be easily 

sublimed at the temperature of the electric arc, a temperature which 

is in the neighborhood of 3,700° C.4 The actual temperature at 

which the volatility of silicates begins is yet to be ascertained, but 

it is certainly lower than that employed in Day and Alien's experiments. It may fall within the range of volcanic temperatures; 

and in that case sublimation can be "supposed to play an appreciable part among the phenomena of eruptions,5 If the more volatile substances accumulate vin the upper portions of a reservoir, they 

would appear among the first ejectamenta; and the difference 

between the earlier and later outflows of an eruption would be partly 

accounted for. Whether this factor in the eruptive process is relatively small or large can not be determined at present. It probably 

exists, and it may be important; but no more definite conclusion can 

be drawn from the established evidence.

OCCLUDED GASES.

Although we can not determine with absolute certainty the origin 

of volcanic gases, the subject is not entirely unsuited to scientific discussion. Some evidence exists, and from it some conclusions may be 

legitimately drawn. It has long been known that nearly if not .quite 

all rocks, upon heating to redness, give off large quantities of gas a

1 Compt. Rend., vol. 138,1904, p. 243.

2 Science, new ser., vol. 23,1906, p. 670.

a Zeitschr. Deutsch. geol. Gesell., vol. 24,1872, p. 493. Condensed from the Italian original by J. Roth. 

See also G. vom Rath, Neues Jahrb., 1866, p.'824, on augite as a fumarole product. H. Traube (Centralbl. 

Min., Geol. u. Pal., 1901, p. 679) has described the artificial production of minerals by sublimation.

* 3,900° to 4,000° absolute. See C. W. Waidner and G. K. Burgess, Bull. Bureau of Standards, vol. 1, 

1904, p. 109.

6 J. Joly (Proc. Roy. Irish Acad., 3d ser., vol. 2,1891, p. 38) mentions the sublimation of enstatite at the 

highest temperatures observed on the platinum ribbon of his meldometer. In this case the temperature 

could not have exceeded 1,700° C. Some of the so-called sublimed silicates of volcanoes, however, may 

not be true sublimates at all, but products of reactions between silica and volatile chlorides or fluorides. 

Such reactions are more'than probable.
VOLCANIC GASES AND SUBLIMATES. 269

fact which was noted by Priestley as early as'1781. 1 In recent years 

these gases have been elaborately studied, and from two points of 

view. At first they were thought to be occluded in the rocks; and, 

indeed, inclosures of carbon dioxide are not rare; but latterly it has 

been shown that igneous action may generate them from the solid 

minerals themselves. Let us first assemble the data, and then con-' 

sider their significance.

That quartz and other crystalline minerals often contain cavities 

filled with carbon dioxide is well known, and inclusions of this order 

have been studied by several competent authorities.2 Hawes and 

Wright examined the remarkable smoky quartz from Branchville, 

Connecticut, which contains so many inclusions of'gas that it explodes 

almost like a percussion cap when struck with a hammer. In this 

case the gas, as analyzed by Wright, gave 98.33 'per cent of C02 , 

with 1.67 per cent of nitrogen, and traces of hydrogen sulphide, sulphur dioxide, ammonia, a fluorine compound, and possibly chlorine. 

Much water was also present with the gaseous inclusions. In other 

minerals other gases are sometimes found in notable quantities, as, 

for example, hydrogen sulphide in a Canadian calcite,3 and marsh 

gas, which Bunsen 4 extracted from the rock salt of Wielieczka. In 

the latter instance the inclosed gases contained 84.60 per cent of 

methane, 10.35 per cent of nitrogen, and small quantities of oxygen 

and carbon dioxide. These minerals, however, are not volcanic, and 

they are cited here merely to show that gaseous inclusions are not 

unusual. The observations of W. Ramsay and M. W. Travers 5 are 

also interesting, for in zircon they found both argon and helium, and 

the latter gas was yielded by a number of other rare-earth minerals, 

and also uraninite, all obtained from pegmatite veins.

In 1876, in the course of his investigations upon the gases evolved 

from meteorites, A. W. Wright 6 found that a specimen of .trap, heated 

to redness, gave off three-fourths of its volume of gas, which contained 13 per cent of carbon dioxide, the remainder being chiefly 

hydrogen. In 1896, W. A. Tilden 7 made a similar observation upon 

the red Peterhead granite. This rock gave off 2.61 times its volume 

of gases, containing 24.8 percent of C02 and 75.2 per cent of hydrogen. A year later 8 Tilden published the results of his experiments

1 See his Jotters to Josiah Wedgwood, in Scientific correspondence of Joseph Priestley, edited by H. Carrington Bolton, New York, 1892, privately published.

2 See especially W. N. Hartley, Jour. Chem. Soc., vol. 29,1876, p. 137; vol. 30,1876, p. 237. G. W. Hawes, 

Am. Jour. Sci., 3d ser., vol. 21,1881, p. 203. A. W. Wright, idem, p. 209.

a See B. J. Harrington, Am. Jour. Sci., 4th ser., vol. 19,1905, p. 345.

« Annales chim. phys., 3d ser., vol. 38,1853, p. 269.

e Proc. Roy. Soc., vol. 60,1896-97, p. 442. Argon and helium have also been found in malacone, a variety 

of zircon, by E. S. Kitchin and W. G. Winterson (Jour. Chem. Soc., vol. 89,1906, p. 1568). Many of the 

rare-earth minerals, according to H. Erdmann (Ber. Deutsch. chem. Gesell., vol. 29,1896, p. 1710), contain 

small quantities of nitrogen.

a Am. Jour. Sci., 3d ser., vol. 12,1876, p. 171.

' Proc. Eoy. Soc., vol. 59,1895-96, p. 223.

8 Chem. News, vol. 75,1897, p. 169. Proc. Roy. Soc., vol. 60,1896-97, p. 453.
270 DATA OF GEOCHEMISTRY.

upon a considerable number of rocks and minerals, 24 examples in all. 

For most of these only partial analyses were made, but in five cases 

the gases evolved were more completely examined. The data are as 

follows for the percentage composition of the gases and for the volume obtained from a unit volume of. rock:

Volume and composition of gases evolved from rock's.

Rock.

Basalt ......................

Volume 

of gas.

2.8 

6.4 

7.3 

17.8 

8.0

Composition of gas.

C02

23.60 

5.50 

77.72 

31.62 

32.08

CO'

6.45 

2.16 

8.06 

5.36 

20.08

CH4

3.02 

2.03 

.56 

.51 

10.00

No

5.13 

1.90 

1.16 

.56 

1.61

Ho

61.68 

88.42 

12.49 

61.93 

36.15

Even such a mineral as beryl gave off 6.7 volumes of gas, in which 

hydrogen largely predominated. The gases appeared to Tilden to be 

wholly inclosed in very minute cavities, so small that little was lost 

when the rocks were reduced to powder. Their extraction was 

effected by the usual process of heating the pulverized material in 

vacuo.

In 1898 M. W. Travers * described a series of experiments upon the 

extraction of gases from various minerals and rocks, which led 

to results resembling those obtained by Tilden. The conclusions 

reached, however, were quite different; for Travers was able to show 

that in some cases at least the gases were not occluded but were 

derived from the interaction of nongaseous substances. Chlorite, 

serpentine, gabbro, mica, talc, feldspar, and glauconite were studied, 

and in each instance the hydrogen and carbon monoxide that were 

evolved by heating the mineral in vacuo were quantitatively related 

to the ferrous oxide and water which the specimen contained. The 

inference is that these gases were generated by a reaction between the 

ferrous salts, the carbon dioxide, and the water of the original silicates. Unfortunately, Travers's conclusions can not be directly 

applied to Tilden's work, for the latter gave no analyses of the rocks 

themselves. It is noticeable, however, that the largest evolution of 

gas cited in Tilden's series was that from the corundum gneiss of 

Seringapatam, and not from the presumably more highly ferruginous 

pyroxene gneiss and basalt.. The yield of gas from beryl was also 

very considerable, a fact which Travers's observations do not explain. 

That molten glass absorbs combustible gases, probably hydrogen, was 

observed by H. Sainte-Claire Deville and L. Troost.3 The glass on 

cooling gives out much of the gas in the form of bubbles. Even

Proc. Roy. Soc., vol. 64,1893-99, p. 130. 2 Compt. Rend., vol. 57, 1863, p. 9G5.
VOLCANIC GASES AND SUBLIMATES. 271

solid glass, at 200° and under a pressure of 200 atmospheres, has been 

found by J. B. Hannay 1 to absorb oxygen and carbon dioxide. 

When the charged glass is cooled under pressure the gases are 

retained, but 011 quick heating to the softening point they are expelled 

with almost explosive violence, driving the glass into foam. By slow 

heating to 300° most of the dissolved gas can be quietly discharged. 

The investigations of A. Gautier 2 led to the same conclusion as 

that reached by Travers, but the work was more extended and various 

methods of attack were employed. Two samples of the same granite, 

collected at different times and heated to 100° in vacuo with sirupy 

phosphoric acid, gave off the following gases, measured in cubic centimeters per kilogram of rock:

Gases evolved by granite in vacuo at 100°.

HC1 and SiF4 .................................................

H2S ...........................................................

C02 ....... ...................................................

Hydrocarbons .................................................

H2 ............................................................

N2 (rich in argon) ..............................................

A

Trace.

1.33

272.6

12.3

53. 05

232. 50

571. 78

B ,.

Trace.

22.7

237.5

5.3

. 191. 48

102. 48

559. 46

On heating the same rock to 300° with water alone gases were 

evolved as follows, in cubic centimeters per kilogram:

Oases evolved by granite heated to 300° with ivater.

H2S. ..........................................................

C02 . ...........................................................

H., ................:...............:.......:................... N;.............................................................

A

1.3

7.2

' 46.0

.3

B

1.0

5.3

14.6

5.9

Hence, it is clear that the action of water alone on" an igneous rock 

moderately heated tends to develop gases closely similar in character 

to those which are emitted by active volcanoes. Heated to redness 

in vacuo, powdered rocks emit much more gas and the volcanic 

phenomena are imitated even more closely. In the subjoined table 

A, B, and C are analyses of gases thus extracted from the granite 

of Vire; D represents a granitoid porphyry, E an ophite, and F Iher1 Chem. News, vol. 44,1881, p. 3. A. A. Campbell Swinton (Chcm. News, vol. 95,1907, p. 134) has also 

shown that gases are occluded by the glass walls of vacuum tubes. Barus's work on the absorption of water 

by glass is considered in Chapter IX.

"Compt. Rend., vol. 131, 1900, p.-647; vol. 132, 1901, pp. 58,189; vol. 136, 1903, p. 10. Annales chim. 

phys., 7th ser., vol. 22, p. 97,1901..
272 DATA OF GEOCHEMISTRY.

zolite. The percentages by volume are given, and the volume of 

gas, reduced to 0° and 760 millimeters, yielded by 1 kilogram of 

rock.

Analyses of gas evolved from powdered rocks heated to redness.

C02 ....... ...................

HaS .........................

CO ..........................

CH4 .. ...... ..................

Hj. .........................

N2 (with rgon) ..............

Volume of gas, cubic centimeters. ....................

A

14.80

4.93

2.24

77.30

.83

100. 10 

2,709

B

8.98

1.71

5.12

1.09

82.80

.42

100. 12 

4,209

c

14.42

. .69

5.50

1.99

76.80

.40

99.80 

2,570

D

59.25

4.20

2.53

31.09

2.10

99.17 

2,846

1?-

35.71

.45

4.85

1.99

56.29

.68

99.97 

2,517

F

78.35

11.85

1.99

.01

7.34

Trace.

99. 54 

5,450

Before heating, these rocks were dried at 250° to 300° to remove 

hygroscopic moisture. The volume of gas extracted from one volume 

of rock amounted to 6.7 from the granite, 7.6 from the porphyry, 7.6 

from the ophite, and 15.7 from the Iherzolite. The granite, it will be 

seen, gives the smallest evolution of gas per volume of material, but 

it is by far the richest in hydrogen. Even in this case, according to 

Gautier, a cubic decimeter of granite at 1,000° would give, calculated 

for that temperature, about 20 liters of mixed gases and 89 liters of 

steam more than one hundred times its initial volume.

In order to prove that the gases are not simply inclosed in the 

rocks, Gautier extended his experiments along several lines. First, 

he argued, inclosed gases* should not vary in composition during the 

process of extraction, whereas gases generated by heat might do so. 

The latter condition held in the case of granite when two fractions of 

the gas were examined separately. The analyses are as follows:

Analyses of gas evolved from granite.

'

C0t .. ................. .................................... '.....'

H2S ...........................................................

co.............................................................

CH4 .......................................................... H2 .. .:..... .....:........::.............................:.....

N... ............ ...............................................

'First 

third.

- 20. 19

1.28

.57

2.04

75.54

.30

99.92

Last twothirds.

6.13

.41

1.02

.80

91.64

.30

100. 30

A similar variation was exhibited during the evolution of gas from

ophite.
VOLCANIC GASES AND SUBLIMATES. . 273

-In his third memoir Gautier showed that ferrous silicates heated 

to redness in a current of steam yield a gas containing 65 per cent 

of hydrogen. Therefore the water of constitution in a rock, acting 

on the compounds of iron therein contained, can give the same 

reaction. To test this conclusion still further, Gautier heated 150 

grams of dried and powdered ophite to redness in vacuo and obtained 

2.25 grams of water and 371 cubic centimeters of gas; containing 202 cubic centimeters of hydrogen and 122 cubic centimeters 

of carbon dioxide. After the evolution of gas had ceased, the material was allowed to cool, and then reheated in a current of steam 

carrying a little carbonic acid. By this means 70 cubic centimeters 

of gas were developed, having, after the removal of carbon dioxide, 

the subjoined composition:

CO......................................................... 3.32

CH4 ......................................................... 6. 08

H2 -.......................................................... 36. 20

N2, etc....................................................... 54. 20

99.80

This gas was certainly not preexistent in the rock, for that had been 

previously exhausted, and yet it was moderately rich in hydrogen.

Gautier's conclusions were, in the main, confirmed by K. Huttrier. 1 

He, too, found that the gases in question are generated by reactions 

brought about by heat within the rock; only, instead of regarding 

the CO as derived from the action of C02 on ferrous silicates, he 

showed that it can be produced by the reducing action of the liberated 

hydrogen upon C02 . Rocks containing more or less water were 

heated in a stream of carbon dioxide, when both hydrogen and carbon monoxide were given off.

That such a reduction was possible had long been known; but 

Gautier, 2 in a later investigation, studied the reaction much more 

thoroughly and found that it was reversible. At a white heat the 

reaction is as follows:

C02 + 3H2 = CO + H20 + 2H2 .

At temperatures between 1,200° and 1,250°, on the other hand, the 

equation becomes 

3CO + 2H20 = 2C02 + 2H2 + CO.

In another series of experiments, Gautier 3 found that hydrogen, 

at high temperatures, reduced carbon monoxide, forming carbon

1 Zeitschr. anorg. Chemie, vol. 43,1905, p. 8.

'Compt. Rend., vol. 142, 1906, p. 1382; Bull. Soc. chlm., 3d ser., vol. 35, 1906, p. 929. Gautier gives 

references to earlier literature. See also O. Boudouard, Bull. Soc. chim., 3d ser., vol. 25,1901. 

a Compt. Rend., vol. 150,1910, p. 1564.

113750° 19 Bull. 695 18
274 DATA OF GEOCHEMISTRY. .

dioxide, water, and either free carbon or methane. 1 At 900° to 

1,000° the reaction appeared to be 

4CO + 2H2 = 2H2O + C02 + 3C. 

Between 1,200° and 1,220° it was 

From these reactions, which seem to be contradictory but which <

depend upon varying conditions of temperature and concentration,

the coexistence of water vapor, hydrogen, and both oxides of carbon in volcanic emanations becomes intelligible. When water emit- ,

ted by heated rocks mingles with carbon dioxide from any source

whatever, within the vent of a volcano, any of these reactions may

take place, and mixed gases, which sometimes contain traces of ..^

formic acid, are generated. This mixture is a powerful reducing

agent, which acts upon the iron silicates in an opposite direction to

that of the oxidizing vapor of water. Either oxidation or reduction

is therefore possible, according to the preponderance of one constitu- (

ent or another among the volcanic gases.

Going further, Gautier 2 investigated the reactions between steam 

and the metallic sulphides. At incipient redness steam changes 

the iron sulphide, FeS, into magnetite, Fe3 04 , with formation of free 

hydrogen and hydrogen sulphide. Galena, in a 'current of superheated steam, was partly sublimed and recrystaUized as such 3 and 

partly decomposed into metallic lead and free sulphur. A little sul- ^ 

phate of lead was formed at the same time. With cuprous sulphide, **- 

under like conditions, copper was liberated and a mixture of hydrogen with sulphur dioxide was formed. The same gaseous mixture 

was also generated by the action of steam upon hydrogen sulphide. 

From these facts Gautier infers that the sulphur dioxide of volcanoes 

is produced by the reduction of sulphides, followed by the oxidation <r 

of the hydrogen sulphide so liberated. This oxidation can be brought 

about, as Gautier 4 has shown, by reactions between metallic oxides 

and hydrogen sulphide, a reversion of some of the other reactions 

studied. At a red heat steam reduces ferrous sulphide, forming magnetite. At a white heat hydrogen sulphide reconverts magnetite into 

FeS, and a mixture of sulphur dioxide with hydrogen is generated. 

Hydrogen sulphide may also react with carbon dioxide to form carbonyl sulphide, COS, and water. In short, Gautier has shown that a 

large number of reactions are possible, starting only with water, cari Sir B. C. Brodie (Proc. Roy. Soc., vol. 21, 1873, p. 245) also obtained methane by the action of electric 

discharges upon a mixture of CO and Hj. The reaction suggested is CO +3H2=CH<+H2O .

4 Compt. Rend., vol. 142, 1906, p. 1465; Bull. Soc. chim., 3d ser., vol. 35, 1906, p. 934. On the" reaction 

betweenCOandSOz, which yieldsCO2 andS,see J.B.Ferguson, Jour. Am.Chem. Soc., vol. 40, 1918,p.l626. *- 

3 This recalls the existence, already mentioned, of galena as one of the Vesuvian sublimates.

4 Compt. Rend., vol. 143, 1906, p. 7; Bull. Soc. chim., 3d ser., vol. 35, 1906, p. 939.
VOLCANIC GASES AND SUBLIMATES. 275

k*

J boil dioxide, and the solid constituents of lavas. Many of these reactions are reversible, and they give rise to nearly all the gaseous mix- 

~"> tures which appear in volcanic emanations. The nitrogen of the vol- 

, canic gases Gautier, like several other authorities, attributes to the 

presence of nitrides in the lava.

 >< In a more general memoir Gautier ' has summed up his views 

J upon the chemistry of volcanism. The phenomena, he thinks, are 

due to fissuring and subsidence in the crust of the earth, whereby 

masses of crystalline rocks are lowered into the heated region. Gases 

are then developed, in accordance with the reactions that he has 

established, under enormous pressures and in immense quantities.

 >*> To illustrate the magnitude of the phenomena to which the reactions 

; may give rise, Gautier in one of his earlier papers shows that a cubic 

i kilometer of granite would yield 26,400,000 metric tons of water and 

"K 5,293,000,000 cubic meters of hydrogen, measured at ordinary temperatures. That amount of hydrogen, burning, would give 4,266,000 

tons of water, making nearly 31,000,000 tons in all, or as much as

 s passes Paris in the Seine during an average flow of 12 hours. 

We can therefore account for the evolution of volcanic steam and 

gases by the action of heat alone without involving either the infiltration of sea water or unknown and imaginary sources of supply deep 

within the bowels of the earth. Given a mechanical source of heat 

and rocks of ordinary composition, and the observed chemical 

phenomena will follow. Gautier, however, goes further than the 

experimental data warrant. He supposes that the nucleus of the

/ earth consists largely of iron, containing hydrogen and carbon 

monoxide in solution. He also assumes the existence of metallic 

carbides, from which CO and hydrocarbons may be generated. 

Sodium chloride, moreover, he regards as nuclear; and upon suppositions of this sort he builds an elaborate argument, of which the 

soundness is yet to be established. It is rich in suggestions which 

^ may or may not bear fruit in future discoveries. The carbide theory, 

I may say, is not due to Gautier alone. It was also advanced by 

H. Moissan,2 who attributes volcanic activity to the action of water 

upon metallic carbides, although these compounds are not seen as 

natural products on the surface of the earth. Water, acting upon

 the artificial carbides, develops hydrogen and hydrocarbon gases; 

the latter, through the influence of heat, partly polymerize to liquid

 -. or solid compounds and partly burn, yielding carbonic acid and water; 

and so the observed order of evolution seen in volcanic eruptions is 

paralleled. . This view also finds some support in the observations of

I Annales dcs mines, 10th ser., vol. 9, 1906, p. 316. Compare F. Loewinson-Lessing (Compt. rend. VII 

Cong. g(5ol. internat., 1897, p. 369), who attributes volcanic gases to the absorption of sedimentary rocks

 > by magmas. Clays yield water, limestones furnish C02j etc.

II Proc. Roy. Soc., vol. 60, 1S9G-97, p. 15G. See also E. Steelier, 14. Ber. Naturw. Gesell. Chemnitz, 1900; 

A. Rossel, Arch. sci. phys. nat., 4th ser., vol. 14, 1902, p. 481; and H. Lenicque, Me'm. Soc. ingi?n. 'civils 

France, October, 1903, p. 346.
276 DATA OF GEOCHEMISTRY.

0. Silvestri,1 who obtained both solid paraffin and liquid hydrocarbons from the lavas of Etna. The theory accounts conveniently 

for some products of volcanism and may be true in part, for the 

carbides are readily formed and are likely to be present below the 

region to which the surface waters penetrate. If deep-seated waters 

really exist, then the carbide hypothesis must be abandoned, or else 

so qualified as to deprive it of any real significance. 2

Probably the most elaborate research upon the gases extractable 

from rocks is that of R. T. Chamberlin. 3 He gives more than a 

hundred analyses of gases obtained from rocks, minerals, and meteorites, finding H2S, CO^, CH4 , H2 , and N2 . Chlorine and its compounds are not reported. The largest quantities of gas were withdrawn from ferromagnesian rocks, and in general, hydrogen and the 

carbon oxides predominated. In deep-seated rocks H^ and C02 

were about equally important; in surface flows the latter gas was 

more conspicuous. Among igneous rocks the oldest yielded the most 

gas; recent lavas gave very much less than the Archean plutonics.

Chamberlin discusses his analyses with much thoroughness, especially with reference to the origin of the gases. Like Gautier he 

ascribes the major portion of them to reactions within the rocks, 

brought about by heating. There must be, however, some gaseous 

occlusions, as in the case of beryl, which yielded him much more 

hydrogen than could possibly be generated by the small amounts of 

water and iron that the mineral contained. Inclusions, such as gas 

bubbles in quartz and the like, he regards as of minor importance. 

The water required to yield the hydrogen Chamberlin attributes in 

great part to the micas of the deep-seated rocks that is, it was 

originally magmatic, arid locked up in the minerals when the magma 

consolidated.

In an interesting series of papers A. Brun 4 has advanced views in 

strong contrast with those of previous writers, for he regards water as 

of minor importance in the production of volcanic phenomena. He 

agrees, however, with Gautier in believing that the gases emitted by 

lava at the instant of its fusion are generated within it by chemical 

reactions. Their sources, he thinks, are nitrides of iron and silicon, 

hydrocarbons, and certain chlorosilicates, such as the compound

1 Gazz. chim. ital., vol. 7, 1877, p. 1. . 2 See the discussion over juvenile and vadose. waters in Chapter VI, and also Gautier's memoir, there 

cited, on the relations between volcanism and thermal springs. The occurrence of hydrocarbons lias 

been noted at many volcanic centers.

3 Pub. No. 106, Carnegie Inst. Washington, 1908. Several analyses of gases from lavas of Mont Pel6e 

and Vesuvius are given by M. Grossmann, Compt. Rend., vol. 148^ 1909, p. 991. Another paper on gases 

from rocks is by R. J. Strutt, Proc. Roy. Soc. vol. 70A, 1907, p. 436. See also G. P. Painfll, (Bull. Acad. 

Roumaine, vol. 3, 1914, p. 72), who gives several analyses.

< Arch, sci. phys. nat., 4th ser., vol. 19, 1905, pp. 439,. 589; vol..22,1906,,p. 425; vol. 25,, 1908, p. 146; vol. 27,

1909. p. 113; vol. 28, 1909, p. 45; vol. 29, 1910, pp. 99,, 618 (the last paper jointly with. L. W. Collet); vol. 30,

1910. p. 576. A general summary of his conclusions is given by Brun in Rev. gdn. sci., 1910, p. 51. His 

complete researches have been brought together in a superb quarto, R'echerches sur I'exhalaison volcaniq ne. 

Geneva, 1911. . .
VOLCANIC GASES AND SUBLIMATES. 277

Ca2Cl2Si03 , which he artificially prepared. 1 Hydrocarbons, in small 

amount, he extracted from lava, as Silvestri had done before him. 

From a Lipari lava, by heating to temperatures between 800° and 

900°, Brun obtained abundant ammonium chloride. Quickly ignited 

at 900° it gave off free nitrogen. At volcanic temperatures the rock 

emitted chlorine and hydrochloric acid. The observed volcanic gases, 

according to Brun, are evolved by the action of the molten magma 

upon the compounds named above, and the temperatures of several 

stages in the process are as follows:

0° to 825°. Volatilization of water. 

825°. First evolution of chloride vapors. 

874° to 1,100°. Temperature of explosions.

1,100°. Mean temperature of flowing lava. 2

The vast clouds of vapor arising from volcanoes are thought by 

Brun to consist mainly of volatilized chlorides, with little or no 

steam. This conclusion is in direct opposition to the prevailing 

belief.

In support of his views, Brun has personally studied Stromboli, 

Vesuvius, the volcanoes of Java and the Canary Islands, and Kilauea. 

In all cases he claims to have found the fresh volcanic glass or cinder 

to be practically anhydrous, and to yield a sublimate of ammonium 

chloride on heating to moderate temperatures. At higher temperatures, at or near the fusing point, gases were given off with explosive 

violence, and of a character quite unlike anything reported by previous observers. For example, four obsidians from Krakatoa gave 

498, 543, 380, and 435 cubic centimeters of gas" per kilogram, of the

following composition:

Gases from Krakatoa.

CL....... .....................................

HC1..................................... -...:.-

S02 ..... ......................................

co2 ............................................

0.............................. ................

CO............................................

A

59. 64 .

11.63

7.99

6.73

.50

4.78

8.73

100. 00

B

49.94

15.54

11.61

6.87

Trace.

5.68

10.36

100. 00

C

'82. 04

None

9 4fi

8.89

6.61

100. 00

D

63.2

KT/inp

| 29.8

Trace.

7.0

100.00

The chlorine contained a little sulphur chloride, and ammonium 

chloride was also collected and determined. Other obsidians from

1 Chlorosilicates known to exist in nature, like sodalite and several other species, are more probable 

sources of chlorine. Sodalite is among the minerals reported as sublimates at Vesuvius.

2 The temperature of the lava at Kilauea is given by Brun as 1,290°±40°. Arch. sci. phys. nat., 4th ser., 

vol. 30,1910, p. 576. Day and Shepherd, by means of a thermocouple lowered into the center of the lava 

pool, determined Its temperature as 1,000°. Carnegie Inst. AVashington Year Book No. 10, 1911 : p. 91. 

T. A. Jaggar, jr. (Jour. Washington Acad. Sei., vol. 7,1917, p. 397, by means of Seger cones found temperatures ranging from 1,120° to 1,170".
278 DATA OF GEOCHEMISTRY.

other volcanoes gave similar results, but with larger proportions of 

HC1 and S02 and much less free chlorine. In order to account for 

the extraordinary difference between these gases and those obtamed 

by former investigators, Brun claims that he studied relatively fresh 

or "live" material, while his predecessors examined old or "dead" 

rocks, such as granites, etc. The distinction is of doubtful significance. 1 The surprising amounts of free chlorine found in Bran's 

analyses are also questionable.

The publication of Bran's researches naturally led to controversy, 

especially between himself and Gautier. 2 Brun urges that the wellknown volcanic sublimates of metallic chlorides, such as the chlorides 

of magnesium and iron, are incompatible with the presence of water 

in the magma, for they are easily hydrolyzed. To this Gautier 

replies that a large amount of hydrochloric acid in the volcanic emanations would inhibit, partially or altogether, the usual hydrolysis. 

Brun of course recognizes the obvious fact that superficial or meteoric 

waters play some part in eruptions, especially in the formation of 

fumaroles, but he regards that part as insignificant and- is most 

emphatic in declaring that the magma itself, in the volcanic chimney, 

is anhydrous. The last point is the one on which he and Gautier 

principally differ. The fumarole gases, so far as they have been 

studied, seem to be generally hydrous, as is shown by a group of 

analyses by Gautier.3 These gases were collected at Vesuvius, A 

and B three months after the eruption of 1906, C and D about fifteen 

months later. Gases A and B were emitted at a temperature near 

300°, C and D at 250° to 280°. The undried gases had the following

composition:

Gases from Vesuvius.

HC1..........................................

co2 ......... ..................................

co...........................................

H2 ............................................

02 .. ..........................................

N2 , A, etc ....................................

H20, vapor ....................................

A

0.78

11.03

None.

1.24

3.72

15.49

67.74

100. 00

B

Trace.

6.68

None.

Trace.

6.00

24.88

62.44

100. 00

C

i\r/-vfiQ

0.80

.15

54

4.59

21.23

72.69

100. 00

D

NOHG

0.66

.02

.02

3.68

17.86

77.76

100. 00

1 Two of Chamberlin's analyses relate to gases from fresh Vesuvian lava of the eruption of 1906. They 

contained principally C02 with much S02, some CO and CH4, and minor amounts of H2 and N2. Theso 

gases bear no resemblance to those by reported Brun. On the other hand, R. Beck (Monatsb, Deutsch. 

geol. Gesell., 1910, p. 240) found in gas extracted from obsidian 14.47 per cent C12 and 50.75 HC1.

2 For Gautier's share in the controversy see Arch. sci. phys. nat., 4th ser., vol. 24,1907, p. 463, and Revue 

sci., 5th ser., vol. 8, 1907, p. 545, and Nov. 27, 1909. See also K. Sapper, Centralbl. Min., Geol. u. Pal., 

1909, p. 609; A. C. Lane, Tufts Coll. Studies, vol. 3, 1908, p. 39; and J. Schwertschlager, Centralbl. Min. 

Geol. u. Pal., 1911, p. 777. Brim's papers have already been cited.

a Bull. Soc. chim., 4th ser., vol. 5, 1909, p. 977. See also Compt. Rend., vol. 148, 1909, p. 1708; vol. 149, 

1909, p. 84.
VOLCANIC GASES AND SUBLIMATES. 279

The water in these gases may of course have been of superficial 

origin. J. Prestwich * has noted that wells and springs near volcanoes generally show a remarkable shrinkage just before eruptions, 

an observation which has some bearing upon the character of the 

more persistent volcanic emanations. The water that so vanishes 

may well reappear in the fumaroles which form, later. A very serious 

objection to Brun's opinions is the fact that deep-seated plutonic 

rocks, which presumably solidified out of reach of percolating waters 

from above, contain micas, of which water is one of the essential constituents. The analcite basalts and the highly hydrated pitchstones 2 

are also difficult to understand if the magma is really anhydrous.

Still more conclusive against Brun's views are the observations 

of Day and Shepherd, already cited, who actually collected considerable quantities of water directly from the molten lava of Kilauea. 

There, at least, the magma is not anhydrous. Brun's arguments by 

which he seeks to prove its anhydrous nature are all discussed by 

Day and Shepherd and effectively answered. The absence of chlorine 

from the gases collected at Kilauea is decidedly adverse to Brun's 

views regarding volcanism. Here, at least, the white cloud of vapor 

is not composed of ammonium chloride.

On the whole, the work of Gautier on the chemistry of the volcanic 

gases seems to be the most general and satisfactory. Deductions from 

it, however, must not be pushed too far, for the evidence does not 

cover all the ground. That rocks contain some gaseous inclusions is 

established, although hydrogen may not be among them; and these 

were probably entangled when the magma first solidified. Percolating 

waters certainly reach volcanic matter from above, and it is highly 

probable that some water filters in from the sea. A volcano on the 

seaboard could hardly escape from receiving some accessions of that 

kind.3 What the relative magnitude of these several factors may be 

we have no means of determining. Furthermore, experiments like 

those of Gautier do not reproduce the conditions existing within a 

volcano. His rocks were heated under conditions which removed the 

gaseous products as fast as they were formed; in a volcanic reservoir 

they must accumulate in contact with or permeating the lava until 

the pressure has been relieved by an explosion. Steam may oxidize 

a ferrous compound, but the hydrogen in its turn is a powerful 

reducing agent. There are here, then, two opposing tendencies, and 

we can not readily decide what sort of an equilibrium would be 

established between them. It is probable that in the depths of a

1 Proc. Roy. Soc., vol. 41,1886, p. 117.

2 In a recent publication (Zeitschr. f, Vulkanologie, vol. 1, p. 3,1914), Bran attempts to show that the 

water of mica is not an essential part of the molecule. Upon that assumption the formula of muscovito 

becomes irrational. According to 0. Stutzer (Monatsb. Deutsch. geol. Gesell., 1910, p. 102) the waterof 

pitchstone is not magmatic. On magmatic water rich inHCl iromu Vesuvian fuinarole see A. Malladra, 

Nature, vol. 100,1917, p. 135.

8 A. Daubrfie, £tud& synthe'tiques de geologic expgrimentale, 1873, pp. 235-241. '
280 DATA OF GEOCHEMISTRY.

volcano temperatures prevail which dissociate water into its elements, 

unless the enormous pressures there existing should compel some sort 

of union that would otherwise be impossible. The chemistry of great 

pressures and concurrently high temperatures is entirely unknown, 

and its problems are not likely to be unraveled by any experiments 

within the range of our resources. The temperatures we can command, but the pressures are as yet beyond our reach. We may devise 

mathematical formulae to fit determinable conditions; but the 

moment we seek to apply them to the phenomena displayed at great 

depths we are forced to employ the dangerous method of extrapolation, and our conclusions can not be verified. .

VOLCANIC EXPLOSIONS.

It is generally admitted that the volcanic gases are the chief agents 

in producing volcanic explosions. This is emphasized by E. Reyer, 1 

by A. C. Lane,2 by S. Arrhenius,3 and more recently by C. Doelter.4 

Lane and Doelter especially regard the deep-seated magmas as 

impregnated by gaseous mixtures which explode upon relief of pressure. As interpreted by Lane, these gases were absorbed by the 

early earth as original and necessary constituents of every magma, 

and their retention is essential to the development and crystallization 

of plutonic and dike rocks. Then- sudden escape, due to the formation of cracks in the earth's crust, is a prime cause of volcanic 

eruptions. Hypotheses of this order, varying only in detail, have 

been widely accepted, but they are not in complete harmony with 

the conclusions of either Gautier or Brim.

It is plain that the consideration of the volcanic gases is direqtly 

connected with various current speculations concerning the origin of 

the earth; and whether we favor the nebular hypothesis or the 

planetesimal conception, lately developed by T. C. Chamberlin, we 

must take them into account. Chamber]in and R. D. Salisbury 5 

regard the gases as originally entangled in the meteoroidal matter, 

from which, according to the planetesimal hypothesis, the earth was 

formed, and they are therefore true additions to the atmosphere and 

hydrosphere. These authors admit that lavas in rising to the surface 

may encounter rocks saturated with moisture, and so generate some 

steam; but they argue that large accessions of water, such as infiltrations from the sea, would absorb more heat than the molten

1 Beitrag zur Fysik der Eruptionen, Wien, 1877.

2 Bull. Geol. Soc. America, vol. 5,1893, p. 259.

3 Geol. Foren. Forhandl., vol. 22,1900, p. 411.

< Sitzungsb. Akad. Wien, vol. 112,1903, p. 681.

5 Geology, vol. l, pp. 588-594, 602-618,1904. See also ante, Chap. II, p. 58. According to Chamberlln 

and Salisbury, crystallization has much to do with the evolution of volcanic gases. When crystals form 

within a lava, they give up their gaseous load, which overcharges the still fluid portions of the magma, 

thereby causing increased pressure and provoking explosions.. See analyses by R. T. Chamberlin, of gases 

from the rocks and phenocrysts of a small tuff cone, Red Mountain, Ariz., cited by W. W. Atwood, Jour. 

Geology, vol. 14, p. 13*8,1906.
VOLCANIC GASES AND SUBLIMATES. 281

magma could afford to lose. Could Stromboli, for instance, which 

has been in continual activity for more than two thousand years, 

have retained its heat under such adverse conditions ? The question 

is pertinent, but not final, for we know nothing about the relative 

quantities of water and lava which are supposed to take part in the 

eruptions. A large molten reservoir and a moderate infiltration of 

water, a supply of heat greater than the wastage, are conceivable; 

and it is also to be remembered that some water lowers the melting 

point of a rock and so helps to preserve its fluidity. A considerable 

degree of cooling is not incompatible with aqueo-igneous fusion and 

would not necessarily check the outflow of a lava stream or the visible activity of a volcano. Arrhenius l claims that a continuous activity, like that of Stromboli, would be impossible without a steady supply 'of water, and he regards the sea bottom as equivalent to a semipermeable membrane through which, by osmotic pressure, the water 

is forced. This pressure at a depth of 10,000 meters would amount 

to 1,700 atmospheres. It is not as a liquid, however, but as a vapor, 

far above its critical temperature, that the water enters the magma, 

hi which it is absorbed much as ordinary water is taken up by calcium phloride. During an eruption it is emitted as steam. The 

reverse movement of magma to the ocean is prevented, according to 

Arrhenius, by the impermeability of the intervening septum to the 

larger and heavier molecules of which the molten rock is composed, 

and especially to the amorphous silica which the entering water is 

supposed to set free. Here the nature of the fluid magma itself is in 

question a subject which will be taken up more fully hi the next 

chapter.

So far, then, we have several distinct hypotheses to account for 

the gaseous exhalations of volcanoes. Arrhenius and Daubre"e, as 

well as many earlier writers, derive them from infiltrations of sea 

water, Arrhenius assuming osmotic pressure and Daubree capillary 

attraction as the method by which entrance to the magma was 

effected. Chamberlin and Lane regard the gases as original inclosures within the earth, now issuing from great depths. Gautier, 

Moissan, and Brun assign their origin to reactions within the rocks 

themselves, but differ as to the details of the process.

Of all these differing views, that of Gautier involves the smallest 

amount of hypothesis, and it also has the merit of simplicity. It is 

not, however, as we have already seen, absolute and final, but it certainly represents a part of the truth, and possibly the major portion. 

On the experimental side it needs further investigation, for it is difficult to suppose that a fluid magma, saturated with gas and water, 

could emerge from a volcano and solidify without retaining some 

gaseous occlusions. In fact, the experiments of R. T. Chamberlin

» Geol. Foren. Forhandl., vol. 22, p. 411,1900.
282 DATA OF GEOCHEMISTRY.

seem to prove that such occlusions exist, and the extent to which 

Gautier's conclusions can be accepted depends upon their magnitude. 

Here we may properly resort to some evidence from analogy. Gaseous occlusions are taken up by iron, steel, and slags in ordinary 

furnace operations, and among them hydrogen is the most conspicuous.1 Data relative to the absorption of hydrogen by iron are 

abundant,2 and meteoric iron seems always to contain it.3 From the 

Lenarto iron T. Graham obtained 2.85 times its volume of gas, 

containing 86 per cent of hydrogen. From the Augusta iron Mallet 

extracted 3.17 volumes, in which hydrogen, carbonic oxide, carbon 

dioxide, and nitrogen were present. There is, to be sure, one adverse 

experiment by M. W. Travers,4 on meteoric iron of unstated origin, 

which is not quite conclusive. By heating this iron, hydrogen was 

obtained; upon dissolving the iron in copper sulphate solution, none 

was evolved. The failure to develop hydrogen in the second experiment is held by Travers to prove its absence, at least as a gaseous 

occlusion. The possibility that hydrogen from a metallic hydride 

might be expended in the precipitation of copper seems not to have 

been investigated. The weight of evidence, so far, is that meteoric 

irons do occlude hydrogen, while meteoric stones yield a larger proportion of carbon dioxide. The Kold Bokkeveld carbonaceous meteorite 

gave thirty times its volume of gas, in which carbon dioxide predominated. The terrestrial native iron from Ovifak, in Greenland, 

gives off when heated, according to Woehler,5 more than one hundred 

times its volume of gas, which is mainly carbon monoxide with a 

little dioxide. If Chamberlin's theory of the earth's origin is correct 

we have in these gases an adequate supply for the maintenance of all 

volcanic phenomena. Or, if the earth itself is equivalent to a huge 

meteorite, as many thinkers have supposed, the analogy between it 

and the smaller bodies accounts for nearly, if not quite, all volcanic 

gases. From this point of view they are occlusions forced out by 

pressure and the resulting mechanical heat. Between this supposition and that of Chamberlin there is little essential difference, at 

least upon the chemical side of the problem. The analogy between 

the expulsion of a gas from the interior of our globe and its evolution

1 See table given by A. C. Lane in his paper, Geological activity of the earth's originally absorbed gases: 

Bull. Geol. Soc. America, vol.5,1893, p. 264. See also references cited by G. Tschermak, Sitzungsb. Akad. 

Wien,vol.75,1877, pp. 170-174. (

2 See, for example, L. Troost and P. Hautefeuille, Compt. Rend., vol. 76,1873, p. 562; L. Cailletet, idem, 

vol. 61, 1865, p. 850; and Thoma, Zeitschr. physikal. Chemie, vol. 3,1891, p. 91. Thoma's paper gives 

many references to literature. H. Wedding and T. Fischer (Ber. V Internat. Kong, angew. Chemie, vol. 

2,1904, p. 25) have summed up the subject quite thoroughly. The papers by J. Parry (Am. Chemist, vol. 

4,1873-74, p. 225; vol. 6,1875-76, p. 107) are also important.

3 T. Graham, Proc. Roy. Soc., vol. 15,1866-67,p. 502. J. W. Mallet,idem, vol. 20,1871-72, p. 365. A. W. 

Wright, Am.Jour.Sci.,3dser.,vol. 9,1875,p.294; vol. 10,1875,p.44; vol. 11,1876,p.253; vol. 12,1876,p. 166; 

J. Dewar and G. Ansdell, Proc. Roy. Inst., vol. 11,1886, p. 445. See also R. T. Chamberlin, loc. cit.

4 Proc. Roy. Soc., vol. 64, p. 130,1898-99.

& Ann. Chem. Pharm., vol. 163, 1872, p. 250. A similar observation by M. Berthelot is recorded by A. 

Daubr<§e, Compt. Rend., vol. 74,1872, p. 1541.
VOLCANIC GASES AND SUBLIMATES. 283

 from meteorites has been well developed by G. Tschermak, 1 who 

regards volcanism as a cosmic phenomenon, of which the typical 

example is to be found in the terrific gaseous upheavals that are seen 

on the surface of the sun.

For each of the theories so far proposed relative to the origin of 

volcanic gases strong arguments can be adduced, and no one should 

be exclusively adopted. The phenomena are probably complex, and 

many activities contribute to their development. Some gas must be 

derived from reactions like those described by Travers. and Gautier; 

some must originate from percolating waters; and a portion of the 

supply may possibly come from deep-seated sources. Whether we 

assume that the earth was once a molten globe or that it was formed 

by the accretion of meteoric masses, gases must be retained within its 

interior, and their escape from time to time would seem to be unavoidable. Molten matter, whether metallic or stony, is known to dissolve gases in large amounts, as silver dissolves oxygen,2 and they are 

expelled in great measure during solidification. They are, moreover, 

expelled explosively, a fact which can be verified in any laboratory; 

but that the expulsion is complete is extremely improbable. Some 

gas, it may be much or little, is retained by the solid mass, and modifies its properties. All of these elements contribute to the phenomena 

of volcanism, but their relative magnitudes can not now be evaluated. 

Speculation upon them may help to stimulate research, but so long 

as the temperatures and pressures within a volcano are unmeasured 

the problems suggested by the hypotheses must remain unsolved. 

The question of volcanic temperatures, of which more will be said in 

the next chapter, is particularly important in the investigation of 

volcanic explosions. The latter are due in part to cooling and the 

violent expulsion of gases following relief of pressure, 'but chemical 

combination may also be manifest in them. If the temperature in 

the depths of a volcano is high enough to dissociate water into its 

elements, then the issuing gases will form an explosive mixture of 

tremendous energy. The moment such a mixture reached the surf ace 

of the molten lava it would have become cool enough to ignite, and 

the characteristic detonations would follow. Hydrogen alone, emerging into the air, might form with the latter a similar mixture and 

produce the same phenomena. E. W. von Siemens,3 observing a series 

of explosions at Vesuvius, ascribed them to this cause. That hydrogen does issue from volcanoes is established; under certain conditions 

it burns quietly, and under others it gives rise to explosions; but in 

either case it develops much heat and so retards the cooling of its 

surrounding matter. One gram of hydrogen, burning to form water,

' » Sitzungsb. Akacl. Wien, vol. 75, 1877, p. 151.

2 One volume of molten silver can absorb 22 volumes of oxygen, which escapes explosively when the metal 

cools. ' This "spitting" of melted silver is familiar to all assayers. 

8 Monatsb. K. preuss. Akad., 1878, p. 558.
284 DATA OF GEOCHEMISTRY.

liberates a quantity of heat represented by 34,000 calories; that is, it 

would raise the temperature of 34,000 grams of water from 0° to 1° C. 

This reaction alone, this combustion of hydrogen in air, evidently 

plays a very large part in the thermodynamics of volcanism.

SUMMARY.

That the volcanic gases appear in. a certain regular order has been 

shown by the various researches upon their composition, and especially by the labors of Deville and Leblanc. What, now, in the light 

of all the evidence, is that order, and what do the chemical changes 

mean?

First. The gases issue from an active crater at so high a temperature that they are practically dry. They contain superheated steam, 

hydrogen, carbon monoxide, methane, the vapor of metallic chlorides, 

and other substances of minor importance. Oxygen may be present 

in them, with some nitrogen, argon, sulphur vapor, and gaseous compounds of fluorine.

Second. The hydrogen burns to form more water vapor, arid the 

carbon gases oxidize to carbon dioxide. From the sulphur, sulphur 

dioxide is produced. The steam reacts upon a part of the metallic 

chlorides, generates hydrochloric acid, and so acid fumaroles make 

their appearance.

Third. The acid gases of the second phase force their way through 

crevices in the lava and the adjacent rocks, and their acid contents 

are consumed in effecting various pneumatolytic reactions. The 

rocks are corroded, and where sulphides occur hydrogen sulphide is 

set free. If carbonate rocks are encountered, carbon dioxide is also 

liberated.

Fourth. Only steam with some carbon dioxide remains, and even 

the latter compound soon disappears.

This seems to be the general course of events, although it is modified in details by local peculiarities. All of the substances enumerated in the lists of gases and sublimates given in the earlier portions 

of this chapter may take part in the reactions, but they do not 

seriously affect the larger processes which have just been described. 

The order is essentially that laid down by Deville and Leblanc, 

except that the early evolution of hydrogen and carbonic oxide is 

taken into account. The current of events may be disturbed, so to 

speak, by ripples and eddies that is, by subsidiary and reversed 

reactions but its main course seems to be clearly indicated.1

i For a summary of our knowledge concerning the magmatic gases previous to the work of Brun and 

Chamberlin, see F. C. Lincoln, Econ. Geology, vol. 2,1907, p. 258. Lincoln gives a good table of analyses 

and proposes a classification of the volcanic exhalations. For a theoretical discussion relative to "gas 

mineralizers" in magmas see P. Niggli, Zeitschr. anorg. Chemie, vol. 75,1912, p. 161, and vol. 77,1912, p. 321'. 

Also Centralbl. Min., Geol. u. Pal., 1912, p. 321; and Geol. Rundschau, vol. 3,1912, p. 472. The article 

"Volcano," by F. W. Rudler, in the eleventh edition of the Encyclopedia Britannica, is an excellent 

summary of the whole subject of volcanism.
CHAPTER IX. 

THE MOLTEN MAGMA. 

v TEMPERATURE.

In the chapter upon volcanic gases the question of temperatures 

\ was purposely left vague, and only the bare fact that they must be 

high was taken into account. For an intelligent study of the magmas, however, some more definite estimates of temperatures are essential, even though their inferior limits can alone be determined with 

^ any degree of certainty. We can measure the temperature at which 

; lavas and their component minerals fuse, under ordinary conditions 

of pressure; but these melting points are modified by various agencies 

/r> within the depths of the earth, and it is not yet possible to strike a 

, definite balance between the opposing forces. By pressure, which 

steadily increases as we descend into the earth, the melting points

*" must be raised,1 but on the other hand the gases that we know to be 

present in the molten mass tend to lower them, and the latter tendency is probably the stronger. The fact that pressure tends to 

prevent the escape of dissolved vapors, and so to increase fluidity, 

must also be taken into account. It should be remembered, moreover, in any reasoning upon the unerupted magma, that the temperature at which it can retain the liquid state is a minimum, and that

 actually it may be very much hotter. The temperature, furthermore, 

j is believed to increase with the depth; but we can do no more than 

to surmise what the conditions may be miles below the apparent 

surface of the lava column.2 Although the characteristics of the individual rock-forming minerals will not be generally discussed until 

the next chapter is reached, our knowledge of their melting points 

may properly be summed up here. It is only within recent years 

that anything like accurate measurements of high temperatures have 

been possible, and therefore the few and scattered older data can be 

ignored.3 The development of the thermocouple by C. Barus in 

the United States Geological Survey, and by H. Le Chatelier in 

France, and the use of the Seger cones in the ceramic industry, have

1 Estimates of the change in fusibility due to pressure have been made by Lord Kelvin, Philos. Mag., 

5th ser., vol. 47,1899, p. 66; C. E. Stromeyer, Mem. Manchester Lit. Philos. Soc., vol. 44, No. 7,1900, and 

J. H. L. Vogt, Min. pet. Mitt., vol. 27,1908, p. 105. The fundamental data, however, are few and unsatisfactory. On the influence of pressure in producing chemical changes in deep-seated rocks, see J. W. 

Judd, Jour. Chem. Soc., vol. 57,1890, p. 404.

2 For estimates of temperatures far within the earth, see Clarence King, Am. Jour. Sci., 3d ser., vol. 45,

1893, p. 7; O. Fisher, idem, 4th ser., vol. 11,1901, p. 414; F. R. Moulton, cited by T. C. Chamberlin, Jour.

Geology, vol. 5,1897, p. 674; and A. C. Lunn, in Chamberlin and Salisbury's Geology, vol. 1,1904, p. 552.

All the estimates reach exceedingly high figures, but they are b'ased upon very doubtful extrapolations.

^ It is conceivable that the increase of temperature with depth may reach a limit which it can not exceed.

3 See, for example, A. Schertel and T. Krhard, Beiblatter, 1879, p. 347; and Schertel, idem, 1880, p. 542.

. . ' 285
286 DATA OF GEOCHEMISTRY.

placed high-temperature p.yrometry upon a new footing and have 

made practicable the class of determinations which we now require.

In 1891 J. Joly * described an instrument (the meldometer) by 

means of which the melting points of minerals could be rapidly and 

easily determined, and several years later R". Cusack 2 reported a 

considerable number of measurements made with its aid. The instrument consisted of a thin ribbon of platinum, upon which the mineral to be examined, hi very fine powder, was placed. The particles 

of mineral dust were observed with a microscope; the ribbon was 

heated with an electric current; and from the expansion of the platinum, which was measurable, the temperature was ascertained. For 

the method by which the meldometer was calibrated the original 

memoir may be consulted.

C. Doelter,3 in recent years, has made many melting-point determinations by means of a thermoelectric couple. In his earlier work the min- ^ 

erals were fused in a gas furnace; later an electric furnace was used.

The determinations by A. Brun 4 were published in 1902 and 1904. 

His fusions were effected in a muffle furnace, heated by a mixture of 

oxygen and illuminating gas, and the temperatures were measured by 

comparison with Seger cones. The crystallized mineral was mounted 

on a slender peduncle of platinum, and so placed that it was heated by 

radiation from the walls of the muffle out of contact with the flame.

In all of the determinations represented by the foregoing investigations the subjective element has been large. The tested samples were 

watched and the human eye" was trusted to determine when softening began and when fusion was complete. Greater exactness has been 

secured in the researches conducted by A. L. Day and his colleagues 5 

in the geophysical laboratories of the United States Geological 

Survey and the Carnegie Institution upon almost ideally pure

1 Proc. Roy. Irish Acad., 3d ser., vol. 2,1891, p. 38.

»Idem, vol. 4,1896, p. 399.

8 Min. pet. Mitt., vol. 20, 1901, p. 211; vol. 21, 1902, p. 23; vol. 23, 1903, p. 297; Sitzungsb. Akad. Wien, 

vol. 114, 1905, p. 529; vol. 115, Abth. 1, July, 1906. The determinations cited are from his third paper.

4 Arch. sci. phys. nat., 4th ser., vol. 13,1902, p. 552; vol. 18,1904, p. 537. For the details of Brun's determinations, see his volume Recherches sur 1'exhalaison volcanique, Geneva, 1911. There are also some 

determinations by W. C. Roberts-Austen, cited by Lord Kelvin, Philos. Mag., 5th ser., vol. 47,1899, p. 6; 

others by J. H. L. Vogt, published in part 2 of Die Silikatschmelzlosungen, and a few by W. Hempel; 

Ber. V Internat. Kong, angew. Chemie, vol. 1,1904, p. 725. For data on shales and clays, see W. C. Heraeus, 

Zeitschr. angew. Chemie, 1905, p. 49. For several rare minerals, see H. L. Fletcher, Sci. Proc. Royal Dublin Soc., vol. 13,1913, p. 443. For Japanese minerals, Y. Yamashita and M. Majima, Sci. Rept. Tohuku 

Univ., vol. 2,1913, p. 175. On methods, with a compilation of data, A. L. Day, Fortschr. Min., Kryst. u. 

Pet., vol. 4,1914, p. 115. .

» A. L. Day and E. T. Alien, Am. Jour. Sci., 4th ser., vol. 19, 1905, p. 93, on.the feldspars. E. T. Alien 

and W. P. White, idem, vol. 21,1906, p. 100, on wollastonite. A. L. Day and E. S. Shepherd, idem, vol. 

22, 1906, p. 265, on the lime-silica series. E. T. Alien, F. E. Wright, and J. K. Clement, idem, vol. 22, 

1906, p. 385, on magnesium metasilicate. E. T. Alien and W. P. White, idem, vol. 27,1909, p. 1, on diopside, etc. E. S. Shepherd and G. A. Rankin, idem, vol. 28, 1909, p. 293, on binary systems of alumina 

with silica, lime, and magnesia. For a summary of these determinations, with corrections, see A. L. Day 

and R. B. Sosman, Am. Jour. Sci., 4th'ser., vol. 31,1911, p. 341. The corrected figures are given in the 

following table. Later papers by N. L. Bowen, Am. Jour.. Sci., 4th ser., vol. 33,1912, p. 554; vol. 38,1914, 

p. 218, and N. L. Bowen and 0. Andersen, idem, vol. 37, 1914, p. 487, are also important. Mixtures 

similar to the last have also been studied by R. Rieke, Chem. Abst., vol. 2, 1908, p. 985, from Stahl u. 

Eisen, vol. 28. - .
THE MOLTEN MAGMA. 287

artificial minerals, and with thermoelectric couples which had been 

calibrated by comparison with the standards at the Physikalische 

Reichsanstalt at Berlin. In these measurements the melting points 

were determined by noting the exact temperatures at which abrupt 

absorptions of heat occurred, thus avoiding errors of judgment.

From the great mass of data now available I have compiled the 

following table, which well exhibits the great divergence between the 

older and the newest determinations. The table might be greatly 

extended, but so many of the published figures relate to unanalyzed 

minerals that their value is problematical. Additional data will be 

given in Chapter X, in describing individual species.

Melting points (°C.) of various minerals, as determined by different investigators. 

 Feldspars and feldspathoids.

Mineral.

AngAbt, artificial. .........

An2Abu artificial. . ........

Labradorite. . ............

Albite.. .................

Orthoclase. ...............

Leucite. .................

Joly.

1,230

1,220

1,175

Cusack.

1, 223-1, 235

1,172

1,298

1, 059-1, 070

Doelter.

1, 165-1, 210

1, 040-1, 210

1, 155-1, 185

1, 135-1, 185

1, 115-1, 170

1, 185-1, 220

1, 275-1, 315

1, 105-1, 125

Brun.

1,490-1,520

1, 544-1, 562

1,370

1,280

1,260

1,259

1,410-1,430

1,270

Day et al.

1,550

1,516

1,477

1,430

1,375

ol,340

1,526

Approximate. Viscosity prevents exact measurements. 

Miscellaneous minerals.

Mineral.

Enstatite .........................

MgSi03 , artificial ..................

Wollastonite °. ....................

Quartzc ..........................

Magnetite. ........................

Hematite .........................

Sillimanite. ......................

Cusack.

............

1, 203-1, 208

1, 187-1, 195

1, 187-1, 199

1, 219-1, 223

1, 187-1, 200

1, 342-1, 378

1,425

Doelter.

1, 375-1, 400

1, 230-1, 255

1, 135-1, 265

1, 085, 1, 200

1, 200-1, 220

1, 065-1, 155

1,265-1,410

1, 190-1, 225

1, 350-1, 400

Brun.

1,366

1,515

1,270

1,230

1,270

1, 060-1, 070

1,750

1,780

1,300

1,270

DayetaL

1,557

1,540

&1, 391

1,625

d\ 387

1, 816

o'Wollastonite has no true melting point. At 1,190° it passes into the pseudohexagonal form, which 

melts at 1,540°.

6 A much lower value, 1,225°, was given by Vogt.

c More properly silica. Quartz is transformed into cristobalite or tridymite at about 800°, and has no 

true melting point of its own. Roberts-Austen gives the melting point of silica as 1,775" and Hempel as 

,685°. Alumina (corundum?) melts, according to Hempel, at 1,880°, magnesia at 2,250°, and lime at 

1,900°. According to C. W. Kanolt(Jour. Washington Acad. Sci., vol. 3,1913, p. 318), AkOa melts at 2,050°, 

MgO at 2,800°, CaO at 2,570*, and Cr2O8 at 1.990°. O. Boudouard (Jour. Iron and Steel Inst., 1905. pt. l, p. 

350) puts the melting point of silica at 1,830*. According to P. D. Quensel (Centralbl. Min., Oeol. u. Pal., 

1906,pp.657,728),tridymite melts as low l.560°,andshowsincipientfusionati,500°. J. B. Ferguson ana 

H. E. Merwin (Am. Jour. Sci., 4th ser., vol. 46,1918, p. 417) find that cristobalite fuses at 1,670° and tridymite at 1,710°,
288 DATA OF GEOCHEMISTRY.

~" A few other interesting determinations of melting point have been 

given by G. Stein, who used the Wanner pyrometer.1 Quartz, or 

rather silica, became a viscous semifluid at 1,600°, and was completely liquid at 1,750°. Above the latter temperature it sublimes. 

For several artificial silicates, corresponding to natural minerals, the 

following melting points were observed: CaSi03, 1,512°; MgSi03, 

1,565°; FeSiOg, 1,500° to 1,550°; MnSi03 ,1,470° to 1,500°; Mg2Si04, 

below 1,900°; Zn2Si04, 1,484°. There is also a research by E. 

Dittler,2 in Doelter's laboratory, in which the work of Day and his 

colleagues is criticized,3 and the attempt is made to show that their 

melting points are much too high. For example, Dittler gives 1,310° 

as the melting point of artificial anorthite, and 1,200° as that of the 

natural mineral. What Dittler has observed, however, seems not to 

be the melting points as defined by Day, but rather temperatures at 

which the crystallized substances begin to show transitions mto the 

very viscous amorphous forms. This is suggested by the second 

paper of Brun, in which he gives the following determinations: 

Artificial anorthite melts, as measured by a calorimetric method, 

between 1,544° and 1,562°. Japanese anorthite fused at 1,490°, 

albite at 1,259°, olivine at about 1,750°, wollastonite at 1,366°, and 

the hexagonal calcium metasilicate at 1,515°. In the glassy state 

the artificial anorthite begins to show deformation at 1,083° to 1,110°, 

and it crystallizes between 1,210° and 1,250°. The albite glass 

softens at 1,177°. These lower temperatures accord fairly with those 

determined by Cusack, Doelter, and Dittler, who seem to have observed them rather than the true melting points. Other discordances 

are due to differences between the substances examined, for natural 

minerals are rarely pure, and in the pyroxene-hornblende-olivine 

series the variations due to isomorphism are very large. One augite, 

for example, contains much, another little, iron; calcium and magnesium also vary in their proportions, and so on. In these series, generally speaking, the melting point falls as the percentage of iron 

increases. The presence of water in a mineral has also a lowering 

effect upon the melting point, and this impurity is not often entirely 

absent. The figures given, therefore, do not, except in those from 

the Geophysical Laboratory and in one or two other cases, refer to 

ideally pure compounds, but to the natural minerals with all their 

defects of composition. They help us to form some idea of the 

temperatures which govern volcanic phenomena, but we can not 

reason upon them as if they were precise and definite. They also 

furnish us with some checks that we can use in studying the order of

iZeitschr. anorg. Chemie, vol. 55,1907, t>. 159.

* Idem, vol. 69,1911, p. 273.

 For a reply to criticisms see Day and Sosman, Am. Jour. Sci., 4th ser., vol. 31,1911, p. 341.
THE MOLTEN MAGMA. 289

formation of minerals when a molten lava cools, although here again 

the data should be handled with great caution. A comparison of the 

different figures for the melting point of the same mineral, say for 

leucite or olivine, will show how great the existing uncertainties 

really are. Furthermore, many of the published melting points have 

no real significance. Some of the minerals for which melting points 

have been recorded break down into other substances before or during 

fusion, a fact of which Brun has taken notice in a number of instances. 

The micas, for example, for which Doelter gives several determinations, lose water and are transformed into other silicates or mixtures 

of silicates, whose precise character is unknown. Garnet, when 

fused, also splits up into two or more compounds, and in such cases 

the recorded melting points are meaningless.

In the geological interpretation of the melting points there is one 

particularly dangerous source of error. We must not assume that 

the temperature at which a given oxide or silicate melts is the temperature at which a mineral of the same composition can crystallize 

from a magma. Many substances exist in more than one modification, and certain forms, which often correspond to natural minerals, 

are developed only at temperatures far below the apparent points of 

fusion. Quartz, for example, ceases to be quartz and becomes tridymite long before it fuses; wollastonite is transformed into a pseudohexagonal substance which is unknown as a mineral species, and the 

melting point of magnesium metasilicate, under ordinary conditions, 

is not that of the orthorhombic enstatite, but of a monoclinic variety. 

In these instances, which will be taken up in detail in the next chapter, the transition temperatures, at which one form changes to 

another, are geologically as important as the melting points, and 

perhaps of even greater value. They are the temperatures above 

which the several species can not form, and therefore they are of the 

utmost significance. Silica crystallizes as quartz only below 800°; 

wollastonite can not exist above 1,190°; and so the formation of 

either mineral in a rock tells us something of the conditions under 

which it solidified. As yet the data of this class are unfortunately 

few, but their number is likely to become much greater within the 

near future.1

For the direct study of the igneous rocks themselves, the available 

melting-point measurements are very few. Mixtures, such as rocks, 

unless they happen to be eutectic, have no distinct melting points, 

and two temperatures at least should be determined for each example.

1 For a discussion of the application of these temperature relations to geological occurrences see J. 

Koenigsborger, Econ. Geology, vol. 7,1912, p. G76, and Neues Jahrb., Beil. Band 32, 1911, p. 191.

113750° 19 Bull. G9o 19
290 DATA OF GEOCHEMISTRY.

The following temperatures, observed by Doelter,1 will serve to 

illustrate this point:

Melting points (°C.) of various igneous rocks.

Rock.

Lava, Vesuvius ........................................

Lava, Etna. . ...........................................

Basalt, Remagen ......................................

Limburgite. ....... ......................................

Phonolite .............................................

Nepheline syenite . . ...................................

Softens.

1,150-1,160

1, 115-1, 125

1, 030-1, OfiO

962-970

992-1, 020

995-1, 000

1,060

1, 040-1, 060

Becomes fluid.

1,240

1,190

1,080-1,090

1,010-1,040

1,060-1,075

1, 050-1, 060

],090

1, 060-1, 100

According to A. Bran,2 the basalt from Stromboli begins to soften 

at 1,130°, and at 1,170° it becomes pasty. The still molten rock contains crystals of augite whose melting point he places at 1,230°. The 

temperature at which the basalt solidified, therefore, can not exceed 

that figure, and may have been much lower. Similar reasoning has 

been employed by C. Doelter,3 based upon the presence of leucite in 

Vesuvian lava. Doelter, however, assigned to leucite a melting point 

which is certainly too low,* and his computations, which must be 

revised, need not be considered further. All we can now say with 

certainty is that the temperature of an emerging lava must be above 

that at which it begins to solidify. That temperature is rarely, if 

ever, below 1,000° C., and the actual temperature not long before 

emission may be hundreds, perhaps a thousand, degrees higher. The 

temperature of the lava pool at Kilauea, as determined by Day and 

Shepherd, was almost exactly 1,000°. Lava at Torre del Greco, says 

A. Geikie, 5 fused the sharp edges of flints and decomposed brass, the 

copper actually crystallizing.. From its effect on flint, it would seem 

that its temperature could hardly be below 1,600°, at which point 

silica softens. If, however, the apparent fusion was due to a solvent 

action of the molten lava, the argument in favor of a high temperature breaks down. A careful study of the conditions under which 

silicates have been sublimed at Vesuvius might shed much light on 

the problem. 6

1 Min. pet. Mitt., vol. 21, 1902, p. 23. J. A. Douglas (Quart. Jour. Geol. Soc., vol. 03, 1907, p. 145), has 

also made a number of similar determinations, and has measured the increase of volume which minerals 

exhibit in passing from the crystalline to the glassy phase. Such an increase is probably the rule, but A. 

Fleischer (Zeitschr. Deutsch. geol. Gesell., vol. 57,1905, p. 201 (Monatsb.); vol. 59,1907, p. 122) has shown 

that molten basalt and some slags expand on solidification. See also A. Harker, Natural history of igneous 

rocks, p. 158.

2 Arch. sci. phys. nat., 4th ser., vol. 13, 1902, p. 367.

s Sitzungsb. Akad. Wien, vol. 112, 1903, p. 681.

4 See preceding table of melting points. Preliminary experiments by A. L. Day have shown that the 

melting point of leucite is certainly above 1,500°.

6 Text-book of geology, 4th ed., p. 304.

o On temperatures at Etna see G. Platania, Atti E. accad. Lincei, ser. 5, vol. 21 (1), 1912, p. 499. The 

figures obtained and those cited from others are very variable. Variations in the composition of the lava, 

and especially in its contents of gases, will account for some of the discrepancies.
THE MOLTEK MAGMA. 291 

INFLUENCE OF WATER.

So far the measurements cited in this chapter relate to dry fusion 

or to the fusion of minerals containing only insignificant quantities 

of hygroscopic water. Within a volcano, apparently, the conditions 

are quite different, and there the presence of water must be taken 

into account, together with the gases which are so powerfully 

operative in producing explosions. The magma, before eruption, 

is something very different from the smoothly flowing stream of 

lava, for it is heavily charged with aqueous vapor and other gases, 

under great pressure, exactly as the soda water in an ordinary 

siphon bottle is loaded with carbon dioxide. When the pressure is 

released the gases escape with explosive force, carrying the liquid 

matter with them. l In the eruption of a volcano this process produces a great quantity of fiery spray, which solidifies in the form of 

volcanic ash, while other portions of the foaming surface of the lava 

cool to pumice. When the lava stream itself appears its effervescence has largely ceased, and it exhibits the ordinary phenomena of 

a cooling liquid.

The condition of the water which is contained within a magma 

is perhaps best explained by certain experiments of C. Barus, 2 who 

found that colloid substances, in presence of solvents, swell up 

enormously, and that at high temperatures the swollen coagulum 

passes into a clear and apparently homogeneous solution. This 

observation he extended to mixtures of ordinary soft glass and 

water, which he heated in closed steel tubes to 210° C. Under these 

conditions 210 grams of glass with 50 grams of water formed a resinous opalescent mass, in which all the water was absorbed. This 

substance, to which Barus gave the name of "water glass," when 

heated in air, swells up enormously, loses water, and forms a true 

pumice. By ordinary exposure to air the substance slowly disintegrates. Salts dissolved in the water do not enter the glass, which 

acts in that respect like a semiperrneable membrane. Hard glasses 

are more refractory; but it is probable that at the temperatures 

and pressures existing within a volcano, all of the silicates would act 

in a similar way and give similar solutions. This may enable us to 

form some notion of the unerupted magma, with its dissolved gases, 

and the changes which it undergoes when the pressure upon it is 

relieved. One effect of the water would be to reduce the temperature at which liquidity could be maintained. An obsidian, in

1 This comparison of a volcano with a bottle of soda water or champagne has been developed by 

S. Meunier. He assumes that the water was originally occluded or combined in the rocks and when the 

latter, by displacement, are brought into the region of high temperature, their aqueous content is set 

free and an explosion becomes possible. See La Nature, vol. 30, pt. l, 1902, p. 386. Also Jour. Washington 

Acad. ScL, vol. 4,1914, p. 213.

2 Am. Jour. Sci.,4th ser., vol. 9,1900, p. 161. The name "water glass," as used by Barus, is unfortunate, for it already belonged to the soluble alkalinesilicates and had been in current use for many years.
.292 DATA OF GEOCHEMISTRY.

presence of water, was found by Barus to fuse at about 1,250°, while 

the resulting pumice melted at 1,650°, approximately. l . MAGMATIC SOLUTIONS.

So far as we can determine, then, the magma, previous to eruption, 

is a mass of rock-forming matter, in a state of fusion, and heavily 

charged with gases under enormous pressure. To what extent and 

how its temperature may vary we do not know, but the pressure 

must fluctuate widely. It is through overcoming pressure that 

eruptions become possible. Then gases and water are largely 

expelled, and a fluid or viscous lava, very different from the original 

magma, remains. By pressure, furthermore, the temperature 

needed to produce complete fluidity is raised, and this fact is emphasized by the phenomena of resorption. A mineral like quartz, 

for example may crystallize within a viscous magma, but when 

the pressure is reduced its temperature of fusion falls, and partial 

or complete re-solution may take place. These partly redissolved 

minerals are familiar objects to the petrologist. 2

Whether the magma itself, at great depths, is homogeneous or 

not is an open question, but it is not emitted homogeneously. 

Different lavas issue, not only from neighboring vents, but successively from the same opening during a series of eruptions. To 

determine the cause of these differences is one of the great problems 

of petrology, and many solutions of it have been proposed, discussed, and either abandoned or partly accepted. To discuss these 

attempts in detail does not fall within the scope of this memoir, but 

the evidence upon which they rest, so far as it touches chemistry, 

must be briefly considered. 3

From a physicochemical point of view a molten rock is to be 

regarded as a solution, behaving in all essential particulars exactly 

like any other solution.' One or more minerals are dissolved in 

another, as salt dissolves in water; or, better, they are mutually 

dissolved, like a mixture of water and alcohol. We can not really 

say that in such a mixture one substance is the solvent and the 

others are the solutes, for the distinction is not a sound one, however

1 Compare F. Giithrie, Philos. Mag., 5th ser., vol. 18, 1884, p. 117, on the change from obsidian to 

pumice by extrusion of water.

2 A good example of the resorption of olivinein a basalt is given by C. N. Fenner, Am. Jour. Sci.,4th 

ser., vol. 29, 1910, p. 230. The author discusses other physicochemical relations of a basaltic magma at 

some length.

s For good summaries on magmatic differenfliation, see J. P. Iddings, The origin of igneous rocks: Bull. 

Philos. Soc. Washington, vol. 12,1892, p. 89; W. C. Brogger, Die Eruptivgesteine des Kristianiagebietes, 

J5t.3,1898, p.334; and F. Loewinson-Lessing, Compt.rend. VII Cong. gfiol.internat., 1897, p. 308. These 

are only a few among many memoirs dealing more or less fully with the subject. Loewinson-Lessing's 

paper is rich in literature references. For a criticism adverse to the idea of magmatic differentiation 

see F. Fouquo, Bull. Soc. min., vol. 25, 1902, p. 349. On magmatic differentiation in Hawaii, see 

R. A. Daly, Jour. Geology, vol. 19,1911, p. 289.
THE MOLTEN MAGMA. 293

convenient it may be in ordinary cases. 1 The different molten 

substances dissolve one another, and if there are any limits to their 

miscibility they have not been determined. I speak now, of course, 

with reference to the constituents of an ordinary fluid lava, and 

these are mostly silicates that is, metallic salts.

The more familiar aqueous solutions of salts are electrolytes, and 

in them the compounds are believed to be dissociated into their ions. 

This dissociation is complete only at infinite dilution; in concentrated 

solutions it is partial, and in a saturated solution its amount may be 

comparatively small. In a molten magma probably all of these 

conditions hold, for as a solution it is dilute with respect to its minor 

components but highly concentrated as regards the more essential 

minerals. As a solution of apatite or rutile it may be very weak; 

as a solution of quartz, feldspar, or pyroxene, very strong. It is, 

however, a conductor of electricity, and, therefore, if the analogy 

between it and ordinary solutions is valid, it is at least partially 

ionized. This is the view adopted by C. Barus and J. P. Iddings,2 

who studied the electrical conductivity of three molten rocks, for 

which the following condensed descriptions may be cited here:

Melting points and silica content of three igneous rocks.

Rock.

Basalt. .....................................................

Approximate melting point.

1, 250

1, 400

1,500

Percentage 

of SiOa.

48. 49

61.50

75.50

At 1,300° the basalt was quite fluid, but at 1,700° the rhyolite 

was &till viscid, and yet the conductivity increased with the viscosity 

and with the silica, in spite of the fact that silica alone is probably 

an insulator. In other words, the fused rocks are electrolytes, and 

the silicates in them are probably more or less dissociated into their 

ions.3 What these ions are we do not yet know; but their ultimate 

identification is not hopeless. The extent of the ionization is also 

unknown, but its existence seems to be established. Furthermore,

1 G. F. Becker (Twenty-first Ann. Kept. U. S. Geol. Survey, pt. 3, 1901, p. 519) proposes to regard the 

eutectic mixtures as the true solvent, and the minerals which separate from them as the solutes. This 

suggestion has attracted much attention, but it can not be fully utilized until we know what the eutectics 

really are.

"Am. Jour. Sci., 3d ser., vol. 44,1892, p. 242.

3 The coexistence in certain rocks of antagonistic minerals like quartz and magnetite may be an evidence 

of dissociation. They should react to form a silicate of iron, but we can readily imagine a highly viscouS 

melt as solidifying so rapidly that all of the ions are unable to find their proper partners. The free oxides 

thereof appear in the solid product. I offer this as merely a suggestion. H. J. Johnston-Lavis, Bull. 

Soc. beige g<5ologie., vol. 22,1908, p. 103, has attributed the quartz in a particular basalt to included gneiss. 

Doelter (Sitzungsb. Akad. Wien, vol. 113, 1904, p. 169) ascribes the early separation of oxides and aluminates from cooling magmas to dissociation.
294 DATA OF GEOCHEMISTRY.

since the several silicates are present in a magma in different degrees 

of concentration, they must be differently ionized, and some of them 

to. a much greater extent than others.

When a salt dissolves in water the temperature of solidification 

is changed. Water, for example, freezes at 0° C., but the addition 

of 23.6 per cent of sodium chloride to it reduces the melting or 

solidifying point to 22°. This depression of the melting point 

is quite a general phenomenon, and from it, by formulae which need 

not be considered here, the molecular weight of the dissolved substance can be calculated. In alloys a similar change can be observed, 

and in some cases it is very striking; the well-known fusible alloys, 

for instance, melt at temperatures below the-boiling point of water.

An igneous rock, so far as our data now go, exhibits the same 

peculiarity, and becomes fluid at temperatures below the average 

melting point of its constituent minerals, and sometimes lower than 

the lowest among the latter. Doelter's figures, as cited on page 290, 

serve to illustrate this point, although the depression is not so marked 

as in the more familiar cases just mentioned. The experiments by 

Michaela Vucnik1 and Berta Vukits,2 who fused together minerals of 

supposedly known melting points and observed those of the mixtures, 

tell the same story. In some cases, however, the interpretation of 

the observations is complicated by chemical reactions, which produced new salts; and it is also affected by the liability of glasses 

to supercooling. Attempts to compute molecular weights from the 

observed depressions gave unsatisfactory results, and led to no definite conclusions. .

N. V. Kultascheff's investigations, 3 although not rigorously comparable with natural phenomena, point in the same direction. Mixtures of Na2Si03 and CaSiO3 were studied, the first salt melting at 

1,007° and the second at a temperature above 1,400°. 4 A mixture 

of 80 per cent of the sodium salt with 20. per cent of the calcium compound fused at 938°, and even greater depressions were produced by 

additions of the still less fusible silica. Upon adding only 6.5 per 

cent of silica to the sodium silicate, the melting point was reduced to 

820°. It was also found that the two silicates united to form at 

least two double salts, a fact which complicates the interpretation 

of the phenomena. 5

1 Centralbl. Min., Geol. u. Pal., 1904, pp. 295,340,364.

2 Idem, pp. 705,739.

a Zeitschr. anorg. Chemie, vol. 35,1903, p. 187.

4 1,540° according to Alien and White. See table of melting points, p. 287.

s A similar study of several binary mixtures of silicates is reported l>y R. C. Wallace, Zeitsclir. anorg. 

Chemie, vol. 63,1909, p. 1. The mixtures examined, however, with one or two exceptions, do not correspond to natural minerals.
THE MOLTEN MAGMA. 295 

EUTECTICS.

When a fused rock, or mixture of similar character, solidifies, it 

can do so in either one of two ways. It may solidify as a unit, 

forming a glass, in which no individualization of its constituents can 

be detected, or it may solidify as a mass of crystalline minerals, each 

one exhibiting its own peculiarities. Between these extremes many 

intermediate conditions, due to partial crystallization, are possible, 

ranging from glass containing .a few crystals to a crystalline mass 

with some glassy remainder left over that is, both processes may 

go on in the same cooling magma, and both, of course, incompletely. 

The more viscous the lava the less easily its materials can crystallize, 

and hence glasses are most commonly derived from magmas rich in. 

silica. Obsidian has essentially the composition of rhyolite.

Let us now consider what will happen when a solution solidifies to 

a cr3rstalline aggregate. Take for example a solution of common 

salt in water, which freezes at -22° C. with a definite proportion 

namely, 23.6 per cent of sodium chloride in the mixture. Upon 

cooling such a solution, if less than that proportion of salt is present, 

ice will crystallize first, but when the indicated concentration and 

temperature have been reached the entire mass salt and water will 

solidify. If, on the other hand, salt is in excess of 23.6 per cent, its 

hydrate, NaC1.2H20, will first appear and continue to be deposited 

until the point of equilibrium has been attained. Then the same mixture will solidify as in the other case. This minimum temperature, 

with its definite, corresponding concentration of salt and water, is 

known as the eutectic point, and at that point the solution and the 

solid have the same composition. 1 Above the eutectic point either 

salt or water may crystallize out, that substance being first deposited 

which is in excess of the eutectic ratio the ratio, that is, of 23.6 

NaCl to 76.4 H2 0. In the freezing of sea water the separation of 

nearly pure ice is seen, because the water is largely in excess of the 

eutectic proportions.

When two salts are lused together and allowed to solidify, the same 

order of phenomena appears, provided that certain conditions are 

satisfied. First, the fused salts must be miscible that is, soluble in 

one another. If this condition is not fulfilled the melt will separate 

into layers. Secondly, they must not be capable of acting upon each 

other chemically, for in that case new compounds are produced. 

Finally, they should not be isomorphous salts, for then no eutectic 

mixture is possible. The feldspars albite and anorthite, for example, 

crystallize together in all proportions, and the melting points of the

i F. Guthrie regarded thesesalLne mixtures with water as definite compounds, which he termed cryohydrates. See Philos. Mag., 4th ser., vol. 49,1875, pp. 1, 206, 260; 5th ser., vol. 17,1884, p. 462. See also M. 

Jlolofl, Zoitschr. physikal. Chemie, vol. 17,1895, p. 325.
296 DATA OF GEOCHEMISTRY.

mixed crystals form a series with no eutectic depression. This difference between isomorphous and eutectic mixtures is fundamental.

Since, now, the fusing point of a lava generally falls below the 

average melting point of its constituent minerals, the foregoing considerations may be applied to its investigation. Some of its components will form isomorphous mixtures, but a part of it will represent 

eutectic proportions which differ with the varying composition 

of different rocks. In each case the substances that are in excess 

of the eutectic ratios are likely to crystallize first, and the eutectic 

mixture itself will probably be found in the groundmass, or solidified mother liquor, from which the crystals have separated. From 

this point of view the study of the eutectics becomes fundamentally 

important in the study and classification of igneous rocks, for they 

chiefly determine the character and order of deposition of the phenocrysts. There are doubtless other factors in the problem, but this one 

is the most fundamental and characteristic. So far none of the 

eutectics in question have been positively identified, although 

various attempts to indicate them are on record, with results which 

may or may not be verified. In Kultascheff's experiments with 

sodium and calcium silicates two eutectic points were noted, which 

represented, however, not a single natural mixture, but a series of 

artificial mixtures wherein both of the original compounds and two 

double salts took part. H. 0. Hofman's work 1 on artificial slags, 

containing iron and calcium silicates, also tells us something about 

possible eutectic points, and other valuable data are given in the 

memoir by A. L. Day and E. S. Shepherd 2 on the compounds of lime 

and silica. The mixtures studied in the latter investigation, however, do not correspond to any known natural associations.

F. Guthrie,3 to whom the expression "eutectic" is due, was the first 

to point out the applicability of his researches to the study of igneous 

rocks, and of late years his suggestions have received much attention. 

J. J. H. Teall 4 was one of the first to develop the subject, and he 

indicated a micropegmatite, with 62.05 per cent of feldspar and 37.95 

per cent of quartz, as a possible eutectic mixture. This possibility 

has been discussed by several writers, and especially by J. H. L. Vogt,5 

who regards a mixture of 74.25 per cent of orthoclase with 25.75 per 

cent of quartz as the true eutectic in this particular instance, and 

shows that it is very close to the average micropegmatite in composi1 Technology Quart., vol. 13,1900, p. 41.

8 Am. Jour. Sci., 4th ser., vol. 22,1906, p. 265.

a Philos. Mag., 4th ser., vol. 49,1875, p. 20.

« British Petrography, 1888, pp. 395-419.

^ Die Silikatschmelzlosungen, pt. 2,1904, pp. 113-128. See also Vogt, Min. pet. Mitt., vol. 24,1906, p. 437, 

vol. 25,1906, p. 361; vol. 27,1908, p. 105. A. C. Lane, Jour. Geology, vol. 12,1904, p. 23. H. E. Johansson, 

Geol. Foren. Forhandl., vol. 27,1905, p. 119; and A. Bygden, Bull. Geol. Inst. Upsala, vol. 7,1904-5, p: 1. 

The subject of eutectics is also fully discussed in Harker's Natural history of igneous rocks, and Elsden's 

Chemical geology.
THE MOLTEN MAGMA. 297

tion. This is not far from the molecular ratio 3AlKSi308 : 5Si02 , 

although simple molecular ratios can not necessarily be assumed in 

eutectic mixtures. The latter, so far as present evidence goes, are 

not definite compounds. The water-salt eutectic is not a hydrate, but 

a mixture of salt and ice, which, however, happens to approximate 

rather closely in composition to NaCl + 10H20.

In the first of the memoirs just cited, which is rich in data relative 

to the physical constants of molten rocks, minerals, and slags, Vogt 

attempts to fix the composition of a number of eutectic mixtures. 

Some of them are as follows, the figures referring to percentages:

68 diopside with 32 olivinc. 

74 melilite with 26 olivine. 

65 melilite with 35 anorthite. 

40 diopside with 60 akermanite. 

74.25 anorthite with 25.75 quartz. 

75 albite with 25 quartz.

The last two ratios are practically identical with the orthoclascquartz ratio as given above. It is, however, a grave question 

whether in a strict sense eutectics of feldspar and quartz are possible. 

Quartz is capable of formation only below 800°, and one modification of it only below 575°. In the pegmatites of Maine, as described 

by E. S. Bastin, 1 the quartz is often of the low-temperature variety, 

and crystallization was further modified by the presence of gaseous 

or vaporous constituents in the magma. Fluid inclusions are also 

common in the quartz. The solidification of these pegmatites was 

therefore a complex process, and by no means so simple as the theory 

of eutectics would seem to demand. A feldspar-silica eutectic, on 

the other hand, in which during prolonged cooling a gradual development of the silica as quartz occurred, may be conceivable.2

The entire subject of eutectics, in reference to rock formation, is 

elaborately discussed by Vogt, who considers them in connection 

with the melting points, and the specific and latent heats of the component minerals. These data, however, are more or less crude, and 

Vogt's results therefore to be regarded merely as first approximations to the solution of the problems proposed, and as subject to very 

critical revision. Vogt also sought to determine the molecular 

weights of several silicates from the observed melting point depressions, and concluded that they were represented by their simplest 

empirical formulae. The fused minerals, as such, exist in the fluid 

magma, although they are partly subject to electrolytic dissociation. 

The latter phenomenon has also been much studied by Doelter.3 

The essential point in Vogt's and also in Doelter's work is that they

1 Jour. Geology, vol. IS, 1910, p. 297. Also, more in detail, in Bull. U. S. Geol. Survey No. 4-15,1911.

» For the conditions under which quartz can form see the section on that mineral in the following 

chapter.

3 Monatsh. Chemie, vol. 28,1907, p. 1313; Sitzungsb. Akad. AVien, vol. 117,1908, pt. 1; Zeitschr. Elektrochemie, 1908, p. 552.
298 DATA OF GEOCHEMISTRY, <"_

attempt to apply modern physicochemical methods to the investiga- ^ 

tion of magmas, and whether their conclusions are maintained or not 

they are at least suggestive.

Up to this point we have considered only simple cases to which the 

theory of eutectics is easily applied. In salt and water we have 

merely a system of two components, and the examples given by Vogt *~ 

are of like simplicity. But igneous rocks are, as a rule, much more 

complex, and may contain from three to many component minerals. 

For conditions like these the theoretical treatment is as yet undeveloped, although the researches of Van't Hoff on the Stassfurt salts 

suggest, with their diagrams, certain analogies which may be followed 

in the future. The laws of equilibrium must apply to all possible 

cases of solution, even though we may be unable as yet to trace the 

details of their working. Just as the Stassfurt problem is complicated 

by the deposition of hydrates and double salts, so from the magma 

complex silicates can form, and the exact conditions under which 

each may develop are so far only partially determined. The difficulties that confront us here are well pointed out by Eoozeboom 1 in T 

his great work on the phase rule, where he calls attention to the fact 

that an igneous rock represents many components and many solid 

phases. Some of the latter are definite compounds, and some are 

mixed crystals from isomorphous series. If the cooling of the magma 

has been too rapid, supersaturation may have occurred, with a change 

in the order of deposition of the minerals and the formation of some 

undifferentiated glass base. Furthermore, lava rising from a great w 

depth undergoes a change of pressure, which modifies the relative 

solubility of its components and alters the position of the eutectic 

point. ,t 

SEPARATION OF MINERALS.

It is evident, from what has been said, that no universal concrete 

rule can be laid down to determine the order in which the different <*. 

minerals will,separate from a cooling magma. The broad, general 

principles are clear enough, but their application to the problem 

under consideration is an affair of the future. For the present, 

therefore, we must depend upon accurate observations and experiments, and in that way accumulate data for theory to work upon. 

The much-cited phase rule, with its diagrams, gives us a mathematical method of dealing with our facts, but it is inoperative without them. When accurate numerical data have been obtained, then 

the rule will become applicable to the relatively simpler cases; but

1 H. W. Bakhuis Eoozeboom, Die heterogenen Oleichgewichte votn Standpunlcte der Phasenlehre, 

vol. 2, Braunschweig, 1904, pp. 240 et seq. For a simple application of a phase-rule diagram to a system 

of two components see W. Meyerhoffer, Zeitschr. Kryst. Min., vol. 36,1902, p. 592. T. T. Read (Econ. 

Geology, vol. 1,1905, p. 101) has discussed the application of the phase rule to the study of magmas, but 

his suggestions have been criticized by A. L. Day and E. S. Shepherd (idem, p. 2S6). C. Doelter (Min. 

pet. Mitt., vol. 25,1907, p. 79) has studied whaLhocalls-the "stability fields" of certain minerals.
THE MOLTEN MAGMA. 299

anything more complex than a four-component system is like!}7 to 

be unmanageable. At present, however, we can see some of the conditions which are involved in the general problem. First, the entire 

composition of the magma must be taken into account, together 

with the pressure under which it solidifies. An ordinary lava, cooling 

on the surface of the earth, will behave very differently from similar 

material which solidifies at a great depth to form a laccolith or 

batholith. In the latter case its gaseous contents are not so completely lost, and they, especially the water vapor, play an important 

part in determining the order of mineral deposition. The retention 

under pressure, of boric acid and fluorine will cause the formation of 

compounds which do not appear in surface eruptions, and such 

minerals as tourmaline and the micas become possible.

If in any given case we regard the eutectic mixture as the solvent, 

the minerals that are in excess of its ratios will be the first to 

crystallize. Their order of deposition will then depend upon three 

essential conditions namely, their relative abundance,1 their solubility in the eutectic, and their points of fusion. Other things being 

equal, the less soluble and less fusible substances will be formed 

earliest. With an excess of alumina, corundum and spinel may 

form, and as a general rule the so-called accessory minerals, the 

more trivial constituents of a rock, are among the first separations. 

Apatite, sulphides, and the titanium minerals belong in this class. 

Although the sulphides are more easily fusible than the silicates 

their insolubility in a silicate magma causes their early precipitation. 

According to J. H. L. Vogt,2 the sulphides are much more soluble 

in very hot magmas than they are at lower temperatures, and this 

order of difference is one which should be taken into account. Solubility varies with temperature, and differently with different substances. It also varies with the solvent, and J. Morozewicz 3 has 

shown that alumosilicates rich in soda dissolve alumina much more 

freely than the corresponding potash compounds, in which it is little 

soluble, if at all. So also the sulphides, as Vogt has pointed out, are 

more soluble in femic magmas than in the salic varieties. They are 

consequently more abundant in basalts and diabases than they are 

in quartz porphyry or rhyolite. We have here, apparently, a caseof limited miscibility between fused sulphides and fused silicates, 

while on the other hand the silicates themselves seem to be miscible 

in all proportions. At> least, in the latter case, no limitation has 

been observed, except in so far as chemical reactivity renders the

1 F. Loewinson-Lessing (Compt. rend. VII Cong. g6ol. internal., 1897, pp. 352-353) has called attention 

to the fact that relative abundance is fundamentally important; that is, silica will divide itself among 

the several bases in accordance with the Jaw of mass action; or, in other words, that law will determine 

what silicates can form. Its detailed application, however, is perhaps not practicable.

3 Die SilikatschinelzlSsungen, pt. 1, 1903, pp. 96-101.

»Min. pet. Mitt., vol. 18,1888-89, pp. 56, 57.
DATA OF GEOCHEMISTRY.

mutual presence of certain species impossible. In an actual magma 

these incompatibilities do not exist, nor do they become evident 

when we fuse together several oxides to form an artificial melt. 

When, however, we fuse mixtures of minerals, as in the researches of 

J. Lenarcic, 1 M. Vucnik,2 and B. Vukits,3 the limitations of this class 

become evident. For instance, when magnetite is fused with labradorite it is absorbed, and upon cooling the melt, augite crystals 

appear. With magnetite and anorthite, hercynite may be formed; 

leucite and acmite give magnetite, leucite, and glass; and so on. 

Again, leucite and nephelite are incompatible with quartz, which 

converts them into feldspars; and a multitude of such conditions 

help to determine what compounds shall crystallize from any given 

magma. In a magma of defined composition certain compounds 

are capable of formation, others are not; and these limitations are 

imperative. In the next chapter, upon rock-forming minerals, they 

will be considered more in detail.

In ordinary solutions two substances having an ion in common 

diminish the solubility of each other. How far this rule may apply 

to magmas is uncertain, and especially so because of our ignorance 

as to what the ions actually are. 4 Still we may assume that olivine, 

Mg2Si04, and enstatite, MgSi03 , have magnesium ions in common, 

and with them the rule ought to work.5 Each should be less soluble 

in presence of the other than it is when present alonej and the same 

condition ought to hold for the two potassium salts leucite and orthoclase, or the sodium couple^albite and nepheline. With mixtures of 

several possible silicates the rule is more difficult to apply, for then 

complex ions are likely to form. For instance, in a magma capable 

of yielding olivine, enstatite, albite, and anorthite the ions may be 

Mg, Ca, Na, Si03, Si04 , AlSi04 , and AlSi308 . Even in such a case, 

which is purely hypothetical, two of the supposed minerals have an 

ion in common, and olivine and enstatite should be the first to separate. Here we have a suggestion of what really happens in a vast 

number of cases, possibly in a large majority of cooling magmas. 

The order in which the minerals are deposited is essentially that 

laid down by H. Rosenbusch,6 namely, ores and oxides first, then

» Centralbl. Min., Geol. u. Pal., 1903, pp. 705, 743.

2 Idem, 1904, pp. 295, 340, 364; 1906, p. 132.

3 Idem, 1904, pp. 705, 739. See also memoirs by B. K. Schmutz, Neues Jahrb., 1897, Band 2, p. 124; K, 

Bauer, idem, Beil. Band 12, p. 535,1899; K. Petrasch, idem, Beil. Band 17, p. 498,1903; H. H. Reiter, idem. 

Beil. Band 22, p. 183,1906; R. Freis, idem, Beil. Band 23, p. 43,1907; V.°P6schl, Centralbl.Min., Geol. u. Pal., 

1906, p. 571; Min. pet. Mitt., vol. 26,1908, p. 412; H. Schleimer, Neues Jahrb., 1908, Band 2, p. 1; M. Urbas, 

idem, Beil. Band, vol. 25,1908, p. 261; M. Hauke, idem, 1910, p. 1; Vera Hammerle, idem, Beil. Band, vol. 

29,1910, p. 719; and H. Andcsner, idem, Beil. Band, vol. 30,1910, p. 467.

< For a discussion of this subject in greater detail see J. H. L. Vogt, Min. pet. Mitt., vol. 27,1908, p. 133.

6 This example is perhaps not perfect, for N. L. Bowen (Am. Jour. Sci., 4th ser., vol. 37,1914, p. 487) has 

shown that enstatite on fusion breaks up into forsterite and free silica. Still, it serves to illustrate the 

principle.

o Neues Jahrb., 1882, Band 2, p. 1. Compare papers by J. Joly, Proc. Roy. Soc. Dublin, vol. 9,1900, p. 

298; J. A. Cunningham, idem, 1901, p. 383; and W. J. Sollas, Geol. Mag., 1900, p. 295. On the order of consolidation of magmatic minerals there is a copious literature.
THE MOLTEN MAGMA. 301

the ferromagnesian minerals, then the feldspars, and finally, if an 

excess of silica is present, quartz. The rule, however, is not and can 

not be universal, and to it there are many exceptions. Its common 

validity must be ascribed to the fact that most igneous rocks are 

formed from relatively few components, with a correspondingly moderate number of possibilities. So far as they are of the same general 

nature they consolidate most commonly in the same general way. 

To a limited degree minerals are deposited from a magma in the 

reverse order of their fusibilit}^, the more infusible first; but the rule, 

as we have seen, is by no means general. In certain cases, however, 

it holds, especially in the formation of the successive members of an 

isomorphous series. Plagioclase feldspars, for example, often exhibit 

a zonal structure, with the less fusible lime salts concentrated at the 

crystalline centers, and the more fusible soda salts proportionally 

more abundant around their outer surfaces. The order of fusibility 

seems to be rather a minor factor in the process of mineral formation 

during magmatic cooling. The early crystallization of leucite and 

olivine may be due either to their relative infusibility, to their insolubility in the remainder of the magma, or, as Doelter l supposes, to 

their superior stability at high temperatures. Viscosity, supersaturation, undercooling, and rate of cooling all play their respective parts 

in the solidification of a magma, and the interpretation of the evidence 

in any particular instance is not a simple matter.2

DIFFERENTIATION.

The question whether there is within the earth, a single, sensibly 

homogeneous magma is one that concerns geology but does not 

seem to be directly approachable through chemical evidence. If, 

however, we consider the problem locally with reference to effusions 

from one definite volcanic center, the chemist may have something 

to say. Even here the discussion must be mainly physical, but chemical principles are also involved in its settlement, for the reason that 

chemical differences characterize the lavas, and they demand consideration.

It is now a commonplace of petrology that within a given area 

there may be a variety of igneous rocks exhibiting a relationship to 

one another and indicating, by their mode of occurrence, that they 

had a common origin. To what is this "consanguinity," as Iddings

' Sitzungsb. K. Akad. Wiss. Wien, vol. 113,1904, p. 495. Doelter gives many data on the separation of 

minerals during the cooling of melts of known composition. The different species were first fused together.

2 The importance of discriminating between the fusibility of a mineral and its solubility in a magma 

is strongly emphasized by A.Lagorio, in Zeitschr. Kryst. Min., vol. 24, 1895, p. 285. Minerals may dissolve at temperatures far below their melting points, just as salt dissolves in water. It is also necessary 

to distinguish between simple solution and chemical reactivity. In the one process a body dissolves 

and recrystallizes from solution without change. In the other it dissolves because of reactions with the 

solvent, and new compounds are generated. In either process, however, a solution may become saturated, 

and then its solvent action ceases. On viscosity as related to chemical composition in silicate fusions see 

E. Greiner, Inaug. Diss., Jena ,1907.
302 DATA OF GEOCHEMISTRY.

_^

calls it, due ? If the lavas, which may differ widely, came from, one 

and the same fissure or crater, how were their differences brought 

about? To this question there have been many answers, but its "~ 

discussion still continues voluminously, and the last word is not yet 

said. If distinct magmas exist, which are ejected sometimes separately and sometimes commingling, the problem becomes apparently w 

simple, and this method of solution has been repeatedly proposed. 

Bunsen assumed the existence of two such magmas, the normal 

pyroxenic and the normal trachytic, and Durocher has put forth v^ 

similar views. Other petrologists have thought that there are more 

than two fundamental magmas, but such a multiplication of assumptions can only end in confusion. The conception is simple enough, tbut its application to observed phenomena is quite the reverse. With y 

this phase of the question chemistry has little to do. The prevalent 

modern opinion favors the idea that at each specified locality there is 

one essentially homogeneous magma, from which, by some process 

of differentiation, the various rock species of the region have been 

derived. Under what conditions and by what processes can such -> 

a differentiation be produced? Upon this problem, presented in 

this form, physical chemistry has some suggestions to offer, regardless 

of the antecedent assumptions or of the geological evidence upon 

which it is based. 1

It is not necessary for us now to consider the historical aspect of 

the discussion, for that has been well done by several other writers. 

J. P. Iddings, especially, in his memoir upon the origin of igneous __ 

rocks,2 and more recently W. C. Brogger 3 and F. Loewinson-Lessing * 

have done full justice to this side of the question. We need only 

take up broadly the hypotheses which have been suggested in order ,L 

to explain the observed differentiation and examine them as to their 

validity. An exhaustive discussion of details is out of the question.

Although R. W. Bunsen was the first to show that a magma is ^ 

really a solution, little attention was paid to this consideration until 

A. Lagorjo,5 in 1887, published his famous memoir on the nature of 

the "glass base" or groundmass. In developing his fundamental 

conception Lagorio called attention to "Soret's principle," which 

asserts that when two parts of the same solution are at different 

temperatures there will be a concentration of the dissolved substance 

in the cooler portion. Through the operation of this process, namely, 

unequal cooling, it was thought that a homogeneous molten mass

1 Harker, in his Natural history of igneous rocks, devotes a chapter to "hybridism" that is, to rocks 

formed by the commingling of magmas. Another chapter is given to the question of differentiation. 

Elsden, in his Chemical geology, also discusses the general problem at some length. A later paper bv 

Harker is in Jour. Geology, vol. 24,1916, p. 554.

* Bull. Philos. Soc. Washington, vol. 12,1892, p. 89.

8 Die Eruptivgesteine des Kristianiagebietes, pt. 3,1898, pp. 276 et seq.

* Compt. rend. VII Cong. g6ol. internat., 1897, p. 308.

s Min. pet. Mitt., vol. 8,1887, p. 421. This memoir is rich in references to former literature.
THE MOLTEK" MAGMA. 303

might become heterogeneous, the substances with which a magma 

was most nearly saturated tending to accumulate at the cooler points, 

leaving the warmer portions with an excess of the solvent material. 

This view was speedily adopted by many petrographers, but objections to it were soon found, and it is now generally abandoned. 

G. F. Becker 1 showed that to produce the observed phenomenon in 

so viscous a medium as molten lava by such a process of molecular 

diffusion would require almost unlimited time; and H. Backstrom a 

pointed out that although the operation of Soret's principle might 

cause changes in the absolute concentration, it could no more alter 

the relative proportions of the dissolved substances than it could in 

a mixture of gases.

Another process which surely plays some part, great or small, in 

the differentiation of magmas is the solution of foreign material. The 

molten lava, as it rises from the depths to the surface of the earth, is 

inclosed between walls of rock upon which it exerts a solvent action. 

This action may be very slight or it may be important; and its extent 

will depend on the character of the magma, the character of the rock 

with which it is in contact, the temperature, and the pressure. Not 

one of these factors can be set aside as negligible. Tfye absorbed 

rock may be either igneous or sedimentary; the effect produced upon 

it may be limited to a thin contact zone or it may permeate large 

masses of material; and no general rule governs the process entirely. 

The wall rock varies in solubility with respect to the magma, and 

this condition, modified as it must be by variations in temperature, 

is of prime importance. If a magma is saturated with respect to the 

substances contained in its walls, its solvent action will be slight; if 

unsaturated, its activity must be greater. A basaltic magma should 

take up silica; a siliceous magma might absorb bases. For example, 

blocks of limestone, more or less altered by contact with the molten 

magma, are ejected from some volcanoes, and may be found embedded 

in the solidified lavas. In extreme cases they may disappear enentirely, leaving a local enrichment in lime salts as evidence of their 

former nature.3 This general process, this assimilation of extraneous 

material, is given much weight by Johnston-Lavis and LoewinsonLessing in their discussions of magmatic differentiation; but its

1 Am. Jour. Sci., 4th ser., vol. 3,1897, p. 21.

3 Jour. Geology, vol. 1, 1893, p. 773. See also F. Loewinson-Lessing, Compt. rend. VII Cong. ge"ol. 

Internat., 1897, p. 390.

8 See, for example, H. J. Johnston-Lavis, The ejected blocks of Monte Somma: Trans. Edinburgh Geol. 

Soc., vol. 6,1892-93, p. 314. Also a paper in Natural Science, vol. 4, 1894, p. 134. P. Loewinson-Lessing 

(loc. cit.) gives many other references to literature on this subject. For experimental data on the solubility of corundum, emery, andalusite, kyanite, kaolin, pyrophyllite, leucite, and quartz in magmas, see 

A. Lagorio (Zeitschr. Kryst. Min., vol. 24,1895, p. 285); also C. Doelter and E. Hussak (Neues Jahrb., 1884, 

Band 1, p. 18), who operated on olivine, pyroxene, hornblende, biotite, feldspars, quartz, garnet, iolite, and 

zircon Jn much the same way. How far these experiments, conducted on small samples during short 

times, can be used to illustrate natural phenomena is doubtful, but they do give some information of value. 

On the absorption of limestone by granite see A. Lacroix, Compt. Rend., vol. 123,1896, p. 1021.
304 DATA OF GEOCHEMISTRY.

effectiveness is by no means universally admitted. R. A. Daly,1 a 

recent advocate of the assimilation theory, has sought to explain the 

mechanism of igneous intrusions by a process which he calls "magmatic s toping." He supposes that a batholithic magma eats its way 

up by solvent action on the invaded rocks. Blocks of the latter, 

loosened by this process, sink into the fluid mass and are gradually 

dissolved. Thus the composition of the magma is altered. Daly 

also argues in favor of the view that such a magma, by "gravitative 

adjustment," will separate into layers, the denser submagma below, 

the lighter above. The latter conception is not new, and has had 

many supporters.

The hypothesis advanced by A. Michel-Levy 2 that differentiation 

is brought about chiefly by a circulation at high temperatures and 

under great pressure of the so-called "fluides mineralisateurs" that 

is, of water and the other vapors or gaseous contents of the magma 

is one which deserves serious consideration. These agents are supposed to entangle certain other constituents, the lighter substances of 

the magma, and to concentrate them in the upper layers of the fused 

mass! Silica and the feldspathic minerals would thus accumulate 

near the top of a volcanic reservoir, leaving the ferromagnesian minerals in greater proportion at the bottom -an order corresponding with 

a common order of ejectment during eruptions. This order, however, 

is not invariable, and in Great Britain, according to A. Geikie,3 

it was generally reversed. There the femic rocks represent the earliest outflows and the salic rocks came later. A progressive enrichment in silica took place, instead of the impoverishment that MichelLevy's process would imply. In the Yellowstone Park, according to 

J. P. Iddings,4 lavas of medium composition were emitted first, and 

the differentiation was a. splitting up of the magma into femic and 

salic portions. The sequence of lavas, then, appears to have been 

different in different regions, and the irregularities remain to be 

explained. Apart from this digression, however, the suggestions of 

Michel-LeVy should be borne in mind. The magmatic vapors must 

exert an important influence upon the process of differentiation, for 

they tend to accumulate in the upper part of a lava column or reservoir and to modify its properties locally. It is quite possible that

i Am. Jour. Sci., 4th ser., vol. 15,1903,.p. 269; vol. 16,1903, p. 107; vol. 20,1905, p. 185; vol. 26,1908, p. 17, 

and in the Rosenbusch " Festschrift," 1906, p. 203. See also Bull. U. S. Geol. Survey No. 209,1903, p. 104, 

on the rocks of Mount Ascutney. A discussion of Daly's views, mainly adverse, at a meeting of the Geological Society of Washington, is reported in Science, vol. 25,1907, p. 621. J. H. L. Vogt (Die SilikatschmelzIb'sungen, pt. 2, 1904, p. 225) regards the assimilation theory as quite untenable. Daly's views have been 

accepted by J. Barrell, Prof. Paper U. S. Geol. Survey No. 57, 1907, pp. 155-156; E. C. Andrews, Rec. 

Geol, Survey New South Wales, vol. 8,1905, p. 126; and A. P. Coleman, Jour. Geology, vol. 15,1907,p. 773. 

On magmatic assimilation in the Adirondacks see W. J. Miller, Bull. Geol. Soc. America, vol. 25, p. 243,1914.

a Bull. Soc. ge"ol. France, 3d ser., vol. 25,1897, p. 367.

' The ancient volcanoes of Great Britain, vol. 2,1897, p. 477.

« Bull. Philos. Soc. Washington, vol. 12, 1892, p. 89. Compare J. E. Spurr, Jour. Geology, vol. 8, 1900, 

p. 621, on the succession of the igneous rocks in the Great Basin of Nevada. Spurr gives a good historical 

summary of the subject, beginning with the pioneer work of Richthofen.
THE MOLTEN MAGMA. 305

they may bring to the top some of the more easily sublimable oxides 

or silicates, together with decomposable fluorides and chlorides, and 

during an eruption these substances would be ejected first. A complete segregation, however, is not assumed 'only a differential concentration of the magmatic components. It is obvious that a more 

important function of the " mineralizers " is to increase the fusibility of the ma,gmatic mass and to diminish its viscosity, thereby 

facilitating crystallization.

In a later paper than the one previously cited G. F. Becker 1 has 

shown that fractional crystallization may have been an important 

factor in producing differentiation. This is a process which is well understood, and it must have been more or less operative. From this 

point of view magmatic differentiation becomes a part of the general 

cooling process, and not a phenomenon to be considered aside from the 

ordinary solidification of a Java. The magma, whether it is forming a 

dike or a laccolith, is inclosed between walls which are cooler than 

itself, and along these surfaces the less fusible or less soluble minerals 

will first crystallize. The process is aided by the circulation of convection currents; and that portion of the fused mass which last 

solidifies, the mother liquor, will be the portion of maximum fusibility, 

and, therefore, approximate to a eutectic mixture. The center of 

the dike or laccolith will thus have one composition and its outer parts 

another. In his memoir upon the Highwood Mountains L. V. 

Pirsson 2 discusses the process in some detail and shows how convection and crystallization may go on together. When great differences 

in specific gravity exist, as in the separation of the heavy titaniferous 

magnetite of the Adirondacks from the lighter rocks of the same 

magmatic mass, 3 the crystallizing substances may settle to the bottom and form a distinct layer quite unlike the superincumbent 

material. Even very moderate differences of density may produce 

similar results, although in less degree. For example, LoewinsonLessing4 has shown that in. certain Vesuvian lavas leucite crystals 

have risen to the top, while augite sank to the bottom.5 In the differentiation of the eruptive iron ores of Norway, as described by J. H. 

L. Vogt,6 the same process may operate, although Vogt gave another 

interpretation to the phenomena. In cases of this kind the liquation 

hypothesis of J. Durocher 7 may be partly applicable, and we can easily 

conceive of the cooling magma as separating into lighter and heavier

i Am. Jour. Sci., 4th ser., vol. 4,1897, p. 257.

a Bull. U. S. Geol. Survey No. 237,1905, p. 183. Compare also A. Harker, Quart. Jour. Geol. Soc., vol. 

50,1894, p. 324, and T. L. Walker, Am. Jour. Sci., 4th ser., vol. 6,1898, p. 410.

8 See J. F. Kemp, Nineteenth Ann. Kept. U. S. Geol. Survey, pt. 3,1899, p. 417.

* Studien ueber die Eruptivgesteine, St. Petersburg, 1899, p. 155.

e Similar observations are recorded .by much earlier workers as, for instance, Charles Darwin, In Geological observations on volcanic islands, 1844, p. 117, and P. Scrope in his treatise Volcanos, 1872, p. 125.

« See summary by J. J. H. Teall in Geol. Mag., 1892, p. 82.

i Annales des mines, 5th ser., vol. 11,1857, p. 217.

113760° 19 Bull. 695 20
306 DATA OF GEOCHEMISTRY.

layers, even before solidification begins. Kemp, in the paper just 

cited, remarks that copper matte settles out almost completely from a 

viscous mixture of matte and slag, although in a large mass of magma 

convection currents might hinder the perfect working of such a 

process. Liquation, then; must be regarded as a possible mode of 

differentiation, but probable only in certain special cases. It implies 

a limited miscibility of the magmatic solutions, and that does not often 

occur. J. Morozewicz/ however, in his experiments upon artificial 

magmas observed several cases in which his melts differed in composition from top to bottom, the undermost portion being the heaviest. Similar differences of density are well known to the. glass 

makers, as shown by variations in refractive capacity between the 

top and bottom portions of their melts. Such a "gravitative adjustment" is presumably most effective in slowly cooling magmas, 

especially when partial crystallization has occurred. The minerals 

first formed must have time to sink. The rate of cooling, therefore, 

is a distinct factor in the differentiation of igneous rocks.

To these agencies in the process of differentiation must be added 

that of pressure. This has been taken into account by Martin 

Schweig,2 whose views may be briefly summarized or paraphrased 

as follows: In a molten magma, under great pressure, partial crystallization occurs; the crystals formed sink within the fluid mass, while 

their mother liquor accumulates above them. An eruption takes 

place, the mother liquid is ejected, and with the consequent relief of 

pressure the fusibility of the separated crystalline matter is increased. 

The latter, remelted, is expelled by a later explosion, ancl in this way 

the magma, originally homogeneous, gives rise to two or more different lavas emitted from the same vent. The separation is effected in 

the first place by fractional crystallization, aided by gravity; and 

then, under reduced pressure, the crystalline layer again liquefies.

This is a plausible hypothesis, but it leaves some things out of 

account. Pressure, in the first instance, raises the melting points of 

the fused minerals, but the water and gases dissolved in the magma 

act in the opposite way. They tend to make the magma more fusible. 

When, by eruption, these gases escape, there will be a decrease of fusibility to offset the gain from reduced pressure, and what the algebraic sum.of this gain and loss may be no man can say. The opposing tendencies may balance, but it is more probable that one or the 

other will be the stronger, and beyond this point, with the available 

evidence, our reasoning can not go. During an eruption the com1 Min. pet. Mitt., vol. 18,1888-89, p. 233. N. L. Bowen (Am. Jour. Sci., 4th ser., vol. 39,1915, p. 175), in 

some experiments upon the magnesian silicates, has found that in a melt olivine and pyroxene crystallize 

out and sink, while tridymite floats. In a later paper (Jour. Geology, 1915, supplementary number) Bowen 

shows that differentiation is chiefly due to fractional crystallization. Assimilation of foreign material 

be .regards as relatively unimportant.

2 Neues Jahrb., Beil. Band, vol. 17, 1903, p. 516. Originally published as a doctoral dissertation. The 

paper contains a good summary down to 1903 of the entire subject of. differentiation. See also a recent 

paper by F. F. Grout, Jour. Geology, vol.26,.1918, p. 626.
THE MOLTEN MAGMA. 307

position of a magma, its gaseous load, its temperature, and the pressure on it are all varying; some of the variations are slow and 

gradual, others are rapid; heat may be lost by cooling 1 or evolved by 

chemical change; and no equation can yet be written in which each 

of these factors shall receive its proper valuation. After eruption the 

phenomena are less complex; but even then we are only able to 

follow them partially. Fractional crystallization, liquation, the influence of dissolved vapors, and the assimilation of foreign material 

are all intelligible processes, but the first one named is the most 

general and presumably the most important of all. Even its influence is variable, however, becoming zero in eutectic mixtures and 

increasing in potency as we recede from the eutectic point. The 

more closely the composition of a magma approaches eutectic ratios 

the less capable of fractionation it becomes.

RADIOACTIVITY.

This chapter would be incomplete without reference to recent 

speculations and investigations -relative to the sources of volcanic 

heat. That heat hitherto has been commonly referred either to the 

molten matter left over after the consolidation of the lithosphere or 

to a generation from mechanical sources, such as pressure and the 

friction due to movements within the crust. The discovery of 

radium, however, which emits heat continuously, has led to new conceptions that are at least worth mentioning.2

The quantity of heat emitted by radium has been measured by 

several investigators. The subjoined table gives most of the results 

obtained, expressed in gram calories per gram of pure radium per 

hour:

Heat emitted by radium.

Authority. Reference. Small calories.

P. Curie and A. Laborcle........

E. Rutherford and H. T. Barnes. 

C. Runge and J. Precht........

F. Paschen....................

J. .Precht.......................

E. v. Schweidler and V. F. Hesa. 

W. Duane.....................

W. Duane.....................

H. Petterason..................

Compt. Rend., vol. 136, 1903, p.

673. 

Philos. Mag., 6th ser., vol. 7,1904,

p. 202. 

Jour. Chem. Soc., vol. 86 (2), 1904,

p. 7. 

Physikal. Zeitechr., vol. 5, 1904,

p. 563. 

Annalen der Physik, 4th ser., vol.

21, 1906, p. 595. 

Monatsh. Chemie, vol. 29, 1908,

p. 853. 

Compt. Rend., vol. 148, 1909, p.

1448. 

Am. Jour. Sci., 4th eer., vol. 31,

1911, p. 247. 

Chem. Abstracts, vol. 5, p. 2365,

1911.

100 approx.

100 approx.

105.

126.

134.4.

118.

120.

104 to 117.

116.4.

! The sudden expansion of the gases released at the beginning of a volcanic eruption must exert a noteworthy cooling effect on the residual magma.

2 A discussion of the purely physical or mechanical sources of heat does not fall within the scope of this 

treatise.
308 DATA OF GEOCHEMISTRY.

The differences between these determinations are due partly to 

differences in the atomic weight assigned to radium and partly to 

different methods of measurement; but they are immaterial in respect 

to the present discussion. It is enough to note that 1 gram of 

radium spontaneously emits heat enough every hour to raise the 

temperature of more than 100 grams of water 1° Centigrade,1 an 

enormous quantity in comparison with the energy displayed in even 

the most violent chemical reactions. How large a part does this 

evolution of heat play in volcanic phenomena or in maintaining the 

temperature of the earth ?

The principal radioactive elements, so far as present knowledge 

goes, are uranium, radium, and thorium. Actinium, ionium, polonium, and a number of less conspicuous radioelements are also 

known, but then" thermal efficiency is yet to be determined. Potassium and rubidium are feebly radioactive. Radium, which is a 

derivative of uranium, is by far the most important radioactive 

element so far discovered, and for immediate purposes is the only 

one which need be taken into account. It has been suggested 

that the atomic degradation which characterizes the elements 

above named is probably a general property of all matter, but that 

is, as yet, only an unproved speculation.2 It may or may not be 

sustained by future investigators.

The materials forming the crust of the earth, whether igneous or 

sedimentary, are now known to be measurably radioactive. This 

radioactivity is even communicated to the waters 3 and the atmosphere, but is most marked in the older rocks, and it is mainly attributed to the widespread diffusion of radium in exceedingly minute 

traces. The other unstable elements, doubtless, play their part, but 

radium appears to be the principal agent in producing the phenomenon. The measurements of what may be called geochemical radioactivity are therefore commonly stated in terms of radium.

The decay of radium is through a series of stages in which a number of products are successively formed. The first of these products, 

the radium emanation, to which the name niton has been given, 

is a gas belonging to the helium-argon group. By decomposing

1 The most probable value is 118 cal.

2 N. R. Campbell (Philos, Mag., 6th ser., vol. 9,1905, p. 531; vol. 11,1906, p. 206) claims to have discovered radioactivity in several common metals. H. Greinacher (Annalen der Physik, 4th ser., vol. 24,1907, 

p. 79) attempted to determine the radioactivity of common substances by a calorimetric method, and 

obtained negative results. If it exists, its intensity is too small to be measured by any known method. See 

also W. W. Strong, Am. Chem. Jour., vol. 42,1909, p. 147; M. Levin and R. Ruer, Physikal. Zeitschr., vol. 

10,1909, p. 576.

3 The radioactivity of many spring wateis has already been noted in the chapter on mineral springs. 

According to J. Joly '(Radioactivity and geology, p. 48), sea water is radioactive to an extent equivalent 

to an oceanic content of 20,000 tons of radium. The deep-sea sediments are much more radioactive. A. S. 

Eve, however (Philos. Mag., 6th ser., vol. 18,1909, p. 102), found much smaller amounts of radium in sea 

water than Joly in fact, only about one-seventeenth as much. For a reply by Joly see the same volume, 

p. 396. F. Himstedt (Physikal. Zeitschr., vol. 5,1904, p. 210) attributes the radioactivity of thermal waters 

to deep-seated radioactive mineials.
THE MOLTEN MAGMA. 309

a rock and .bringing it into solution this gaseous, radioactive substance can be isolated, and its amount determined by its action 

upon the air within an electroscope. The details of the operation 

need not be considered here. They are given by Strutt in his papers 

upon radium in rocks, and are also summed up by Joly in his treatise 

upon "Radioactivity and geology." The amount of emanation is 

strictly proportional to the amount of radium from which it was 

generated, provided enough time is allowed for it to accumulate until 

its rate of production and rate of decay are in exact equilibrium. 

These rates are known to a fair degree of approximation, and hence 

measurements of the emanation are easily restated in equivalent 

quantities of radium.

Since 1906 numerous determinations of radium in rocks have been 

made, especially by R. J. Strutt and J. Joly.1 From Strutt's measurements, as corrected by Eve and Mclntosh, the radium in 28 igneous 

rocks ranges from 0.30 X 10~12 to 4.78 X 10~12 grams per gram of material. The average is 1.7xlO~12 . The highest values were obtained 

from granites, the lowest from basalts and olivine rocks. For sedimentary rocks the average of 17 determinations gave 1.1 xlO~12 

grams per gram, the mean of the two averages being 1.4 X 10~12 . 

This amount is equivalent to an emission of heat, the heat given out 

by radium, about 28 times as great as is needed to account for the 

observed temperature gradient within the crust of the earth.

Joly's figures are much higher than those of Strutt, and cover a 

much larger number of determinations. As summed up by him,2 

the mean radium content of igneous rocks is 5.5xlO~12 grams per 

gram, and that of sedimentary rocks 4.3xlO~12 . Joly, moreover, 

finds only slight differences (as compared with Strutt's results) 

between the plutonic rocks and those of volcanic origin. The discordance between Strutt and Joly I can not attempt to explain; but 

it seems probable that the granitic rocks and perhaps also the nepheline syenites should show the highest values. In them the minerals 

of uranium, radium, and thorium are principally concentrated.3

1 See Radioactivity and geolgy, already cited. For Striutt's papers see Proc. Roy. Soc., ser. A, vol. 77, 

1906, p. 472; vol. 78,1906, p. 150; vol. 80,1908, p. 572; vol. 84,1910, p. 377. The figures given by Strutt in the 

first of these papers involved an erroneous constant and were corrected by A. S.Eve and D. Mclntosh, Philoa. 

Mag., 6th ser., vol. 14,1907, p. 231. These author^ also measured the radioactivity of various rocks near 

Montreal. See also memoirs by C. C. Farr and D. C. H. Florauce, Philos. Mag., 6th ser., vol. 18,1909, p. 812. 

A. L. Fletcher, idem, vol. 20,1910, p. 36; vol. 21,1911, pp. 102, 770; vol. 23,1912, p. 279; A. Gockel, Jour. 

Chem. Soc., vol. 100, pt. 2,1911, p. 174, abstract; E. H. Buchner, idem, p. 243, abstract; and vol. 102, pt. 2, 

1912, p. 525, abstract. Recent papers by Joly, partly upon radium and partly upon thorium, are in Philos. 

Mag., 6th ser., vol. 17,1909, p. 760; vol. 18,1909, pp. 140, 577; vol. 20,1910, pp. 125,353; vol. 23,1912, p. 201; 

vol. 24,1912, p. 694. On the radioactivity of pitchblende see H. H. Poole, idem, vol. 19,1910, p. 314. On 

Australian minerals, D. Mawson and T. H. Laby, Chem. News, vol. 92,1905, p. 39. On lavas, O. Scarpa, 

Atti R. accad. Lincei, 5th ser., vol. 16,1907, p. 44; R. Nasini and M. G. Levi, idem, vol. 15,1906, p. 391; vol. 

17, p. 432; and G. T. Castorina, Neues Jahrb., 1907, p. 11 (abstract). J. W. Waters (Philos. Mag., 6th ser., 

vol. 19,1910, p. 903) has studied the presence of radioactive minerals in common rocks. On radiothorium 

see G. A. Blanc, idem, vol. 13,1907, p. 378; vol. 18, 1909, p. 146.

2 Radioactivity and geology, p. 275.

8 G. von dem Borne (Zeitschr. Deutscb. geol. Gesell., vol. 08, 1906, p. 1) has found the granite of the 

Erzgebirge to be strongly radioactive.
310 DATA OF GEOCHEMISTRY.

The radioactivity of the sedimentary rocks may be due to a distribution of the radium emanation by circulating waters, in which the 

gas is soluble. That of mineral springs is explicable in the same 

way.

An attempt to compute the total amount of radioactive matter in 

the earth and its thermal significance would be obviously premature. 

The available data are too scanty, too discordant, and in some 

respects too incomplete for such a purpose. According to Strutt, 

the radium must be mainly within an outer shell of rock of relatively 

moderate thickness; for if it were uniformly diffused throughout the 

earth the earth would be growing warmer, which is highly improbable. 1 Its precise distribution, however, can only be determined 

after many more experiments have been made, in which the radioactivity of each rock mass shall be correlated with its exact petrologic 

nature. An apparent "granite," for example, may be really a metamorphic rock in masquerade, and not a true plutonic. The thorough 

geologic and petrologic study of each sample of rock should go hand in 

hand with its radioactive measurement.2

On the purely qualitative side of the problem more can be said. 

It is proved tha't the surface rocks of the earth contain diffused 

radium, and that must be emitting heat at a definite rate. On this 

basis of fact Maj. C. E. Button 3 has suggested that volcanic heat 

may be developed by radioactivity in limited tracts from 1 to 3 and 

not over 4 miles below the surface of the earth. Heat thus developed 

might so accumulate as to fuse the rocks in which it was generated. 

In time, when enough material was melted,- the water inclosed in the 

magma thus produced would become explosive, and an eruption 

would follow. Then a period of quiet would ensue, more heat would 

be released by the subterranean radium, and another explosion would 

occur. Thus Button explains the periodicity of eruptions, and he 

argues that no permanent reservoirs of molten magma are required 

in order to account for volcanic phenomena. Button's views have 

been opposed by G. I). Louderback,4 partly on geologic grounds, and 

partly because radiferous minerals, such as uraninite, are not found 

among volcanic products. On the other hand Joly 5 is inclined to 

favor Button's suggestion, having found Vesuvian lavas to be highly 

radioactive. His figures, for the lavas emitted since 1621, give, in 

mean, 12.3 X 10~12 grams of radium per gram of rock, an astonishingly 

high figure, which seems to need verification.

1 See also C. Liebenow, Physikal. Zeitschr., vol. 5,1904, p. 625.

2 See A. Holmes (Sci. Progress, vol. 9, p. 12,1914) for an interesting paper on the distribution of radium 

in the earth.

8 Jour. Geology, vol. 14,1906, p. 259.

«Idem, p. 747.

B Philos. Mag., 6th ser., vol. 18,1909, p. 577. The possible relation of volcanism to radioactivity is also 

discussed by F. von Wolff, Zeitschr. Deutsch. geol. Gesell., vol. CO, 1908, p. 431.
THE MOLTEN MAGMA. 311

Iii speculations of this order there is a certain fascination, but also 

a tendency to push the conclusions too far. It is extremely probable that radioaction may account for part of the heat emitted from 

volcanic vents, but whether it is the greater part or not is more uncertain. In any case, the reported radioactivity of potassium 1 must be 

taken into account, a metal millions of times more abundant than 

radium, which fact may offset its feeble intensity. Mechanical agencies and chemical reactions also count for something in volcanic 

phenomena, and the heat due to them should not be ignored. It is 

much more likely that the phenomena are produced by a combination 

of causes than that they are ascribable to any one cause alone.

The final degradation products of radium, and therefore of its 

parent, uranium, are helium2 and lead. The elementary pedigrees 

are somewhat long, and their consideration in detail would be out 

of place here. The rate at which helium is generated is fairly well 

known, and upon that constant a method of determining the age of 

minerals has been based.3 Given the amount of uranium or radium 

in a rock or mineral, and also the amount of helium which it contains, 

and the length of time required to generate the helium is easily 

calculated.

By this method Rutherford computed the ages of a fergusonite 

and a uraninite at something over 500,000,000 years; the figures 

being minima because some helium might have escaped. Joly, 

revising the calculations by means of a different value for the rate 

of change of uranium into radium, reduced the estimate to 241,000,000 

years. By the same method Strutt found the age of thorianite from 

Ceylon to be above 280,000,000 years, and of a Canadian sphene 

710,000,000 years. For more modern minerals Strutt found much 

smaller ages. Sphserosiderite from the Oligocene was found to be 

8,400,000 years old; hematite from, the Eocene 31,000,000; and 

hematite from the Carboniferous 150,000,000 years. He also studied 

a number of phosphatic nodules, which gave still lower figures, in one 

case 225,000 years. The order of the geological formations was approximately followed, the oldest minerals being found in the oldest rocks.

1 See N. R. Campbell and A. Wood, Proc. Cambridge Philos. Soc., vol. 14,1906-1908, p. 15; and Campbell, 

idem, pp. 211, 557. Also E. Henriot, Compt. Rend., vol. 14S, 1909, p. 910; Henriot and G. Varon, idem, 

vol. 149, p. 30; J. C. McLennan and W. T. Kennedy, Physikal. Zeitschr., vol. 9,1908, p. 510. M. Levin and 

R. Ruer (idem, vol. 10, 1909, p. 576) studied many elements other than those strongly radioactive and 

found only K and Rb to emit undoubted radiations. W. W. Strong (Am. Chem. Jour., vol. 42, 1909, 

p. 147) obtained similar results and also found radioactivity in erbium. R. J. Strutt (Proc. Roy. Soc., 

vol. 81 A, 1908, p. 278) suggests that the helium in the Stassfurt salts may be derived from potassium.

2 According to P. Soddy (Philos. Mag., 6th ser., vol. 10, 1908, p. 513), uranium and thorium both yield 

helium.

8 See E. Rutheiford, Radioactive tiansformations, p. 187. For applications of the method, see R. J. 

Strutt, Pioc. Roy. Soc., ser. A, vol. 81,1908, p. 272; vol. 83,1909, pp. 96, 298; vol. 84,1910, pp. 194,379. For 

criticisms of the method, see M. Levin, Zeitschr. Elektrochemie, vol. 13,1907, p. 390; G. F. Bockef, Bull. 

Geol. Soc. America, vol. 19,1908, p. 113; J. Joly, Radioactivity and geology, ch. 11; J. Koenigsberger, Geol. 

Rundschau, vol. 1,1910, p. 245: and A. Holmes, Proc. Roy. Soc., vol. 85A, 1911, p. 248. Holmes's book, 

The age of the eaith, London, 1913, is an excellent summary of the subject. See also recent papers by Joly 

in Philos. Mag., 6tb ser., vol. 22,1911, p. 358, and Sci. Progress, vol. 9,1914, p. 37.
312 DATA OF GEOCHEMISTRY.

To this method of-computing the age of minerals there are serious 

objections, especially if it is assumed that all the helium was generated 

by radioactive decay. Helium is found in the nebulae, the hotter 

stars, and the sun; but uranium, thorium, and radium have not yet 

been recognized in the solar spectrum. B. Hasselberg 1 in a careful 

comparison of the solar spectrum with that of uranium failed to 

detect its presence. P. G. Nutting 2 was similarly unsuccessful when 

he compared Exner and Haschek's table of the spectrum of uranium 

with a 30-foot reproduction of the solar spectrum.3

Furthermore, helium is not only found in minerals containing 

uranium, but also under other conditions. For example, in certain 

beryls Strutt 4 found much helium but no radioactive parent from 

which it might have been generated. The helium in such cases may 

have originated from unknown radioactive substances of such great 

instability that no trace of them remains unchanged, but this is pure 

speculation. A. Piutti5 found that helium is generally present in 

minerals containing glucinum, but with no regular ratio between 

the two elements. He has also e shown that helium is absorbed 

by certain melted salts and minerals, and that its presence therefore 

tells nothing of their age.

The permeability of quartz to helium, which is perceptible at 220° 

and very great at 1,100°, may have some bearing on the problem 

now before us.7 That minerals should differ in their permeability, 

and also in their capacity for retaining helium is almost beyond 

question. Another difficulty is suggested by the work of Ellen 

Gleditsch,8 who has shown that the ratio between radium and uranium 

in minerals is not constant. That ratio enters into many of the 

calculations relative to the age of radioactive minerals. A still 

greater difficulty appears when we take into consideration the 

presence of helium in the waters of many springs. From one spring 

at Santenay, in France, according to C. Moureu and A. Lepape,9 

17,845 liters of helium are brought to the surface in one year. To 

supply this quantity the radioactive decay of not less than 91 metric 

tons of radium, or 500,000,000 tons of pitchblende or thorianite 

would be required. The presence of helium in natural gas, in one 

instance up to nearly 2 per cent, is similarly suggestive. From all

i K. Svensk. Vet. Akad. Handl., vol. 45, No. 5, p. 63,1910.

«See Becker, Bull. Geol. Soc. America, vol. 19, p. 123,1908.

8 F. W. Dyson (Astron. Nachrichten, vol. 192, p. 82, 1912) has reported, somewhat doubtfully, lines of 

radium in the spectrum of the solar chromosphere. H. Giebeler (idem, vol. 191, p. 401,1912) has detected 

radium and its emanation in the spectrum of the star Nova Geminorum 2. These observations need confirmation. Recent investigations have failed to support them.

«Proc. Roy. Soc., vol. 80A, 1908, p. 572.

o Atti R. accad. Lincci, 5th ser., vol. 22, pt. 1,1913, p. 140.

8 Jour. Chem. Soc., vol. 100, pt. 2, p. 88,1911 (abstract).

7 See A. Jaquerod and F. L. Terrot, Compt. Rend., vol. 139,1904, p. 789; vol.. 144,1907, p. 135.

8 Idem, vol. 148,1909, p. 1451; vol. 149,1909, p. 267. 

»Idem, vol. 155,1912, p. 197.
 THE MOLTEN MAGMA. 313

these considerations it is evident that primordial or "fossil" helium 

must.be taken into account, and also the possibility that the reaction 

by which uranium decays may be reversed under the enormous 

pressures and high temperatures existing within the earth.1 On the 

basis of that supposition we can imagine that some of the helium 

found in minerals may be only left-over material from the original 

reactions in which the heavier elements were formed.

Assuming that lead is the final product of the degradation of 

uranium, B. B. Boltwood 2 has sought to determine the age of certain minerals from the ratio between the two metals when both 

are present. The ratio multiplied by 1010 gives the approximate 

age. By this method Boltwood found ages for various minerals 

ranging between 410,000,000 years for a uraninite from Connecticut 

to 2,200,000,000 years for Ceylonese thorianite, the last figure being 

several times larger than that given by Strutt. The great uncertainty 

of such calculations, however, has been clearly pointed out by G. F. 

Becker,3 who has applied it to the rare-earth minerals from Baringer 

Hill, Llano County, Texas, with the.following results:

Yttrialite (Mackintosh)......................... 11,470,000,000 years.

Yttrialite (Hillebrand)......................... 5,136..000,000 years.

Mackintoahite (Hillebrand).................... 3, 894,000,000 years.

Nivenite (Mackintosh).......................... 1, 671,000,000 years.

Fergusonite (Mackintosh)......................... 10,350,000,000 years.

Fergusonite (Mackintosh)........................ 2,967,000,000 years.

The list might be extended still further, but it is full enough as it 

stands. The minerals are all from one deposit, which is of about the 

same geologic age as the Connecticut uraninite studied by Boltwood, 

and yet the figures vary .enormously, even for a single species. That 

lead is sometimes derived from uranium seems to be well established, 

but that all the lead in a given mineral had that origin is extremely 

doubtful. In the evolution of the chemical elements lead was 

probably formed before uranium and, being more stable, was generated in larger quantities. Magmatic lead, as represented by galena, 

has been found in pegmatites, and in some form or other it might 

easily have become entangled with other impurities when crystallization of the uranium ores first took place. This possibility, which 

has since become almost a certainty, is pointed out by Becker very 

clearly. In fact, it has been proved that the lead obtained from 

radioactive minerals is of at least three different kinds, namely, 

normal or primordial lead, uranium lead, and thorium lead, the 

last two being known as "isotopes" of the ordinary metal. These

1 This possibility is recognized by Rutherford, op. cit., p. 194; by M. Levin, Zeitschr. Elektrochemie, 

vol. 13,1907, p. 390; and also by Becker in the paper just cited.

3 Am. Jour. Sci., 4th ser., vol. 23,1907, p.86.

3 Bull. Geol. Soc. America, vol. 19,1908, p. 134. See also F. Zambonini, Atti R. accad. Lincei, 5th scr. 

vol. 20, pt. 2,1911, p. 131: and R. W. Lawson, Univ. Durham Philos. Soc. Proc., vol. 5,1913, p. 26.
314 DATA OF GEOCHEMISTRY.

isotopes are identical with normal lead in nearly all their chemical 

relations, except that they differ from it in atomic weight and also 

in such physical properties as density. The atomic weight of normal 

lead has been shown by G. P. Baxter and F. L. Grover 1 to be constant, for their very exact determinations, made with lead from eight 

different sources, gave values ranging from 207.20 to 207.22, a variation quite within the allowable limits of experimental error. Lead from 

uranium ores, however, as shown by the researches of T. W. Richards 

and his colleagues and of Honigschmid and Horovitz,2 has an atomic 

weight varying from 206.042 to 207.004; while that from thorium 

minerals is at least as high as 207.77, and probably higher.3 It has 

been suggested that normal lead is a balanced mixture of these two 

isotopes, but its definite atomic weight negatives that supposition. 

In order to fulfill such a condition it would be necessary that the 

isotopes should always commingle in the same definite proportions, 

and that is extremely improbable. Furthermore, there seems to be 

a fundamental difference between normal lead and its radioactive 

varieties; one is the product of the orderly evolution of the chemical 

elements; the others are formed by their decay. The normal elements 

are now regarded as veritable storehouses, of potential energy, which 

in radioactive transformations becomes, in part, at least, kinetic. 

Stability characterizes the one class of elements, instability the otherFrom the evidence given by the atomic weights it is now plain 

that the uranium-lead ratio is of very questionable value in determining the age of minerals. Many uranium ores contain thorium also, 

and that of course changes the ratio and tends to lower their estimated ages. The presence of primordial lead lowers them still more, 

and to an uncertain extent, for the relative proportions of the three 

components of isotopic lead are not easily determinable. For thorianite, Boltwood, using the uranium-lead ratio alone, found an age 

of 2,200,000,000 years. In that mineral, however, thorium is more 

than five times as abundant as lead. If that is taken into account, 

the computed age of the mineral is reduced to less than 500,000,000 

years, and no exact figure can be given. How much of the lead in 

the thorianite is primordial is unknown, and the rate of change from 

thorium to lead is not fixed with any great assurance of certainty.4

i Jour. Am. Chcm. Soc., vol. 37,1915, p. 1027.

1 For a summary of all these determinations see F. W. Clarke, Proc. Nat. Acad. Sci., vol. 4,1918, p. 181.

a A more recent determination by Honigschmid gives 207.90 as the atomic weight of thorium lead. Even 

this may not be final.

4 For additional arguments against calculations of this sort, see G. F. Becker, Bull. Geol. Soc. America, 

vol. 26,1915, p. 171. See also H. S. Shelton, Chem. News, vol. 116,1917, p.259. For their defense, see A. 

Holmes and R. W. Lawson, Philos. Mag.,6thser., vol. 28,1914, p. 823, and voU29,1915rp.673; also Holmes, 

Proc. Geologist's Assoc., vol. 26,1915, p. 289, and Geol. Mag., 1915, p. 104, and 1916, p. 265. In Bull. Geol. 

Soc. America, vol. 28,1918, p. 745, J. Barrell gives a good summary of all the methods for computing the age 

of the earth, and indorses those based on radioactivity.
THE MOLTEN MAGMA. 315

One other method for computing the age of minerals is based on 

radioactive phenomena. In certain minerals, micas for example, 

little colored rings are observed, surrounding a presumably radioactive nucleus. From measurements of those "pleochroic haloes" 

J. Joly and others 1 have computed ages comparable with those 

derived from the helium and lead ratios. The data, however, are 

not sharp, and it is doubtful whether much weight can be given to 

the calculations.

Finally, the discordance between the foregoing computations and 

other methods of ascertaining the age of the earth is extraordinary. 

From chemical denudation, from paleontological evidence, and from 

astronomical data the age has been fixed with a noteworthy degree 

of concordance at something between 50 and 100 millions of years.2 

The high values found by radioactive measurements are therefore to 

be suspected until the discrepancies shall have been explained.3

' See J. Joly and A. L. Fletcher, Philos. Mag., 6th ser., vol. 19,1910, p. 630; and J. Joly and E. Rutherford, 

idem, vol. 25,1913, p. 694.

2 See G. F. Decker, Smithsonian Misc. Coll., vol. 56, No. 6,1910.

a See J. Marckwald, Ber. Deutsch. chem. Gesell., vol. 41,1908, p. 1559, for a summary of the subject of 

radioactivity. Madame M. S. Curie's Traite1 de radioactivity, 2 vols., Paris, 1910, is also most important. 

In Zeitschr. Elektrocheinie, vol. 13,1907, pp. 369-406, is a series of papers forming a symposium upon tho 

subject. A Curious attempt to reconcile radioactive and erosional methods of computing time is due to 

F. C. Brown (Le Radium, October, 1912, p. 352), who suggests that the sodium of tho ocean may have been 

derived from some unknown radioactive parent. This is speculation pure and simple.
CHAPTER X.

ROCK-FORMING MINERALS. 

PRELIMINARY STATEMENT.

When, a magma solidifies, it may do so either as a glass or as an 

aggregate of crystalline minerals. In the latter process, which is the 

first step in the general process of magmatic differentiation, and in 

which molecular diffusion plays an important part, each mineral is 

distinctly marked off in space and occupies a region of its own. It 

may not be pure; it may entangle, during its formation, particles of 

other substances, but its definiteness and integrity are none the less 

clear.

Although more than a thousand distinct mineral species are known 

to science, only a relatively small number of them are in any sense 

abundant or to be reckoned as essential constituents of rocks. An 

igneous rock is usually a mixture of silicates, containing, as basic 

metals, potassium, sodium, calcium, magnesium, iron, and aluminum, 

with oftentimes free silica. Other substances are present only in 

quite subordinate proportions. There may be small quantities of 

phosphates, especially apatite, some fluorides, various free oxides, the 

titanium minerals, zircon, sulphides in trivial amount, and sometimes 

free elements, such as graphite or metallic iron; but these constituents of a rock have only minor significance, except in some exceedingly rare instances. The exceptions need not be considered now.

Each mineral species, using the word in its rigorous sense, is a definite chemical entity, capable of formation only under certain distinct 

conditions, and liable to alteration in various ways. Each one may 

be studied as it exists in nature, with the alterations which it there 

undergoes; or it may be investigated synthetically, with reference to 

its possible modes of origin, or by analytical methods in order to 

determine what transformations it is likely to experience. Both 

methods, the experimental and the observational, furnish legitimate 

lines of attack upon geological problems. A mineral, with its associations, is a record of chemical changes that have taken place, but they 

do not end its history. It is still subject to decay that is, to transformations into other forms of matter, and their study, chemically 

or in the field, constitutes an important part of metamorphic geology. 

Alteration products are highly significant, but their investigation 

demands extreme caution. Errors of diagnosis have been common in 

the past, both as to the nature of substances and with regard to their 

implications; and each reported case of alteration, therefore, should 

316
ROCK-FORMING MINERALS. 317

be submitted to the severest scrutiny. A compact muscovite, for 

example, may easily be mistaken, on superficial examination, for talc 

or serpentine; and errors of that kind may deprive an otherwise good 

observation of all its meaning.

Many compounds, identical with natural minerals, have been prepared by laboratory methods, which may either reproduce the conditions existing in nature or vary widely from them. Each substance 

can be made in several different ways, and so the results of experiment may or may not have geological significance. In one process 

the conditions of a cooling magma are exactly paralleled; whereas 

another may have no relation to the phenomena observed by the 

geologist. The correct interpretation of laboratory experiments is, 

therefore, an affair demanding nicety of judgment; and the discrimination between relevant and irrelevant data is not always easy. The 

synthesis of a mineral may be chemically important, and yet shed 

no light upon the problems of geology. Still, indirect testimony is 

often of value, and none of it should be rejected hastily.

In the following pages the more important minerals of the igneous 

and metamorphic rocks will be considered individually, from the 

various points of view indicated in the preceding paragraphs. Importance and abundance, however, do not always go together. A 

relatively infrequent mineral may be important for what it signifies 

and therefore receive more attention here than some of the commoner 

species. In a general way the usual order of mineral classification will 

be followed, but not rigorously. In some cases, for. petrographic 

purposes, two minerals may be studied consecutively which in a textbook upon mineralogy would be widely separated. The problems 

of paragenesis, which are all-important here, are quite independent 

of mineralogical classification. The titanium minerals rutile, ilmenite, perofskite, and titanite, for example can be properly considered 

successively, although one is an oxide, two are titanates, and the 

fourth is a titanosilicate. Petrographically they belong together; 

mineralogically they do not. So much premised, we may go on to 

study the individual species, as follows, beginning with the free elements, carbon and iron. The inclusion of diamond in this category 

may be justified by the fact that it is essentially a mineral of magmatic origin.

DIAMOND AND GRAPHITE.

Diamond. Pure or nearly pure carbon. Isometric. Atomic 

weight, 12; molecular weight, unknown. Specific gravity, 3.5. 

Atomic volume, 3 4. Hardness, 10. Colorless to black, with various 

shades of yellow, green, blue, red, and brown. The black carbonado 

has a specific gravity slightly below that of the pure diamond, ranging from 3.15 to 3.29. Fusibility unknown, probably above 3,000°.
318 - DATA OF GEOCHEMISTRY.

Combustible at high temperatures, between 800° and 850°, according 

to H. Moissan, 1 although oxidation begins at a point somewhat 

lower.

The diamond has been produced artificially in several ways. 

R. S. Marsden,2 in 1880, claimed to have obtained minute crystals 

from the solution of amorphous carbon in molten silver. J. B. Hannay,3 by heating amorphous carbon with bone oil and metallic 

lithium, under great pressure, also secured a few crystals of carbon 

which appeared to be in the form of diamond. Moissan,4 however, 

was the first to obtain unimpeachable results. He dissolved carbon 

in melted iron, and cooled the mass suddenly under pressure. From 

the cooled iron, undoubted crystals of diamond were isolated. 

J. Friedlander 5 dissolved graphite in fused olivine and obtained 

small diamonds, and R. von Hasslinger,6 by solution of amorphous 

carbon in an artificial magnesium silicate magma, was similarly 

successful. A little later R. von Hasslinger and J. Wolff 7 repeated 

and varied this experiment, using different magmas in order to 

determine under what conditions the diamonds would be formed. 

Magnesia and lime appeared to favor the crystallization of the carbon, but a high proportion of silica in the magma seemed to act 

adversely. According to Hasslinger and Wolff, a carbide is probably 

first produced, from which, later, the carbon separates in adamantine 

form. L. Franck and Ettinger8 claim to have found diamonds in 

hardened steel, and A. Ludwig 9 observed their formation when an 

electric current was passed through an iron spiral embedded in 

powdered gas carbon, in an atmosphere of hydrogen and under 

great pressure. In a later investigation Ludwig 10 fused a mixture 

of carbon and iron in an electric stream, and then suddenly chilled 

the mass by admission to it of water under a pressure of 2,200 atmospheres. Under these conditions of pressure and instantaneous 

cooling the fused carbon solidified in the form of minute diamonds. 

With slow cooling the more stable graphite is produced. These 

observations accord with the conclusions of Moissan, 11 who finds

1 Compt. Rend., vol. 135,1902, p. 921.

2 Proc. Roy. Soc. Edinburgh, vol. 11, 1880-81, p. 20. 1C. Chrustchofl (Zeitschr. anorg. Chcmie, vol. 4, 

1893, p. 472) also obtained diamonds from solution in silver. Molten silver, he says, can dissolve about 

0 per cent of carbon.

3 Proc. Roy. Soc., vol. 30,1880, pp. 188,450.

4 Compt. Rend., vol. 116, 1893, p. 218. Also C. Friedel, idem, p. 224, and Q. Majorana, Atti R. accad. 

Lincei, 5th ser., vol. 6, pt. 2,1897, p. 141.

5 Abstract in Geol. Mag., 1898, p. 226.

<> Monatsh. Chemie, vol. 23,1902, p. 817.

' Sitzungsb. Akad. Wien, vol. 112,1903, p. 507.

a Chem. Centralbl., 1896, pt. 2, p. 573. From Stahl u. Eisen, vol. 16, p. 585.

»Chem. Zeitung, vol. 25,1901, p. 979.

l ° Zeitschr. Elektrochemie, vol. 8,1902, p. 273.

» Compt. Rend., vol. 140,1903, p. 277. See also Annales chim. phys., 8th ser., vol. 5, 1905, p. 174. On 

diamonds in blast-furnace slag and the conditions of their possible formation, see H. Fleissner, Oesterr. 

Zeitschr. Berg- u. Huttenw., vol. 58, 1910, pp. 521, 539, 550, 570. See also P. Neumann, Zeitschr. Elektrochemie, vol. 15,1909, p. 817. W. von Bolton has reported the recrystallization of diamond dust, under 

the influence of mercury vapor derived from sodium amalgam, Zeitschr. Elektrochenie, vol. 17, p. 971,1911.
ROCK-FORMING MINERALS. 319

that when carbon is raised to a high temperature at atmospheric 

pressure it volatilizes without fusion and on cooling always yields 

graphite alone. In Moissan's work, however, external pressure is 

not applied. It is generated by internal expansion within the iron, 

when the surface of the latter is suddenly cooled. The addition of a 

little ferrous sulphide to the fused iron seems to increase the yield 

of diamonds.

According to G. Rousseau,1 diamond is formed at ordinary 

pressures when acetylene, generated from calcium carbide, is decomposed by an electric current at a temperature of about 3,000°. 

C. V. Burton 2 claims to have obtained diamond crystals from solution in molten lead to which about 1 per cent of calcium had been 

added. Furthermore, Sir William Crookes 3 has detected diamonds 

in the ash of cordite which had been exploded in closed vessels. In 

the last instance the pressure generated must have been very high.

Still more recently Sir Charles A. Parsons 4 has made numerous 

experiments upon the formation of diamond, starting with Moissan's 

method but varying the details. He concludes that the diamonds 

are formed at a temperature of about 690° C. and that they are 

derived from occluded gases, of which carbon monoxide is the most 

important. When the melt is slowly cooled, no diamonds are produced, because the gases escape; but with practically instantaneous 

cooling the gases are retained, and then diamonds can be formed. 

High pressures, except in so far as they are developed during the 

cooling of the melt and within it, are unessential to success. Parsons suggests that carbides, such as carborundum, are first formed, 

and that the actual reaction involves them, together with iron, 

sulphur, and carbon monoxide.

In nature the diamond was formerly found most commonly in 

gravels, and until recently little was known of its parent rock. It 

has also been discovered in several meteorites, as in the meteoric 

stones of Novo-Urei, Russia,5 and Carcote, Chile, 8 and the meteoric 

iron of Canyon Diahlo. 7 The Novo-Urei stone is essentially a mixture of olivine, 67.48 per cent, with augite, 23.82 per cent, and therefore resembles a peridotite. The Canyon Diablo iron contains 

nodules of iron sulphide, troilite, which recall Moissan's latest 

experiments, and also graphite. For each occurrence the artificial

i Compt. Eend., vol. 117,1893, p. 164.

»Nature, vol. 72,1905, p. 397.

» Proc. Roy. Soc., vol. 76 A, 1905, p. 458.

4 Engineering, vol. 105, 1918, p. 485. Still other experiments have been made by O. Ruff (Zditschr. 

anorg. allgem. Chemie, vol. 99,1917, p. 73), but I have not seen the details of them.

» M. Erofdef and P. Latschinoff, Jour. Russ. Chem. Soc., vol. 20,18S8, p. 185. Abstract in Jour. Chom. 

SOC., vol. 56, 1889, p. 224.

s w. Will and J. Pinnow, Ber. Deutsch. chem. Gesell., vol. 23,1890, p. 345.

' G. A. Koenig and A. E. Foote, Am. Jour. Sci., 3d sen, vol. 42,1891, p. 413.
320 DATA OF' GEOCHEMISTKY.

production of diamonds-furnishes a parallel Hasslinger's work in 

one case, Moissan's in the other.

The origin of the diamond as a mineral seems to be clearly indicated by the foregoing data. It is formed by crystallization from the 

solution of carbon in a fused magma, and the latter, in most cases, 

seems to have had the composition of a peridotite an association 

which is also seen in the Novo-Urei meteorite. In the South African 

mines the diamonds occur in or near volcanic pipes, embedded in a 

decomposed rock, which has been described as a peridotitic tuff or 

breccia.1 The volcanic character of this matrix or "blue ground" 

was early recognized, and several authorities, notably the late H. 

Carvill Lewis, 2 have ascribed the origin of the diamonds to the solvent action of the molten peridotite magma upon the carbonaceous 

shales through which it has penetrated. In some cases, however, 

these shales are absent, and W. Luzi 3 has shown that when "blue 

ground" is fused at a temperature of about 1,770° the diamonds 

which it contains are perceptibly corroded. That is, the magma itself 

is proved to be a solvent of carbon; which may just as well have come 

from below as from contact metamorphism. In Lewis;s papers it is 

pointed out that in a number of other regions diamonds are associated more or less closely with rocks of serpentinous that is, peridotitic character. T. G. Bonney, 4 however, has sought to prove that 

the true matrix of the Cape diamond is eclogite, from which he 

says the mineralhas crystallized as an original constituent, just as 

zircon crystallizes from granite. The very intimate association of 

these diamonds with garnet lends support to this view. On the 

other hand, G. F. Williams 5 states that he crushed and examined 

20 tons of eclogite at Kimberley and found no trace of diamonds. 

He also reports a Kimberley diamond which contained an inclusion 

of apophyUite. If the diagnosis was correct, it throws doubt upon

1 See E. Cohen, 5 Jahresb. Ver. Erdkunde, Metz, 1882, p. 129.

2 Papers before the British Association in 1886 and 1887. In full, edited by T. G. Bonney, in Papers 

and notes on the genesis and matrix of the diamond, London, 1897. The suggestion that the shales are 

the source of the carbon is adopted from E. J. Dunn, Quart. Jour. Geol. Soc., vol. 37, 1881, p. 609. See 

also L. De Launay, Les diamants du Cap, Paris, 1897; G. F. Williams, The diamond mines of South 

Africa, New York, 1905, 2 vols.; Sir William Crookes, Diamonds, London and NOAV York, 1909; and P. A. 

Wagner, Die diamantfiihrenden Gesteine Siidafrikas, Berlin, 1909. Wagner gives a full bibliography 

relative to South African diamonds. An English edition appeared in 1914, For bibliographic notes on 

diamonds see J. A. Thomson, Econ. Geology, vol. 5, 1910, p. 64. Other memoirs on the South African 

diamonds are by R. Beck, Zeitschr. Deutsch. geol. Gesell., vol. 59,1907, p. 275; F. H. Hatch, Nature, vol. 

77,1908, p. 224; J. P. Johnson, Trans. Inst. Min. and Met., vol. 17,1908, p. 277; .and F. W. Voit, Eng. and 

Min. Jour., vol. 87, 1909, p. 789. For a review of several memoirs upon South African diamond, see E. 

Kaiser, Zeitschr. Kryst. Min., vol. 51, p. 399, 1912. On the diamond sands of Southwest Africa see the 

dissertation by G. Scheuring, Gottingen, 1914.

8 Ber. Deutsch. chem. Gesell., vol. 25, 1892, p. 2470.

4 Proc. Roy. Soc., vol. 65, 1899, p. 223. Bonney's view is accepted by A. L. Du Toit, Eleventh Ann. 

Rept. Geol. Commission, Cape of Good Hope, 1907, p. 135. G. S. Corstorphine (Trans. Geol. Soc. South 

Africa, vol. 10, 1907, p. 65) shows that t'ne supposed eclogite, in which he found diamonds, consists really 

of garnet-pyroxene nodules which are inclosed in_the kimberlite. These nodules are concretionary in 

character.

»Trans. Am. Inst. Min. Eng., vol. 35, 1905, p. 440. Ann. Rept. Smithsonian Inst., 1905, p. 193. On 

an inclusion of garnet in diamond see R. J. Button, Nature, vol. 75, 1907, p. 488.
ROCK-FORMING MINERALS. 321

the igneous origin of the gem, for apophyllite is a highly hydrous 

mineral. D. Draper and W. H. Goodchild, 1 however, regard eclogite 

as the parent rock, from which the kimberlite of the "pipes" was 

derived. The eclogite is supposed to have contained microscopic 

diamonds, from which, by a process of secondary enrichment stones 

of economic size were developed in the kimberlite matrix. Whether 

this view is accepted or not it is difficult to see how enormous 

diamonds, such as the Cullinan, for example, could have been 

formed instantaneously. It would seem that there must have been 

some process of growth, even if it is as yet unexplainable. According to H. S. Harger 2 the Vaal River diamonds are derived from 

andesitic lava, and H. Merensky 3 reports them in pegmatite and 

diabase. The diamonds recently discovered in Arkansas, however, 

are associated with peridotitic rock closely resembling kimberlite.4 

Microscopic diamonds have also been found in the chromite of the 

Coleraine district, Canada.5

In Brazil diamonds are associated with hydromica schists and the 

peculiar form of quartzite known as itacolumite; and 0. A. Derby 8 

finds no evidence of olivine rocks anywhere in the diamond-bearing 

region. Similar conclusions have been reached by J. C. Branner,7 

who states that the diamonds are not only obtained from gravels, 

but also directly from decomposing quartzite. He also gives a full 

list of the associated minerals. Furthermore, near Bellary, Madras 

Presidency, India, M. Chaper 8 found the diamond to be apparently 

derived from a pegmatite consisting of rose-colored orthoclase and 

epidote. Near Inverell, New South Wales, T. W. Edgeworth 

David 9 found diamonds in a matrix of hornblende diabase. In 

short, though much evidence points to an igneous origin for tho

1 Mining Jour., vol. 113, 1916, pp. 357, 365.

2 Trans. Geol. Soc. South Africa, vol. 12,1910, p. 139. See also E. II. V. Melvill, idem, p. 205, on stones 

from tho Roberts-Victor mine.

3 Zeitschr. prakt. Geologic, 1908, p. 155.

« See G. F. Kunz and H. S. Washington, Am. Jour. Sci., 4th ser., vol. 24,1907, p. 275; and H. D. Miser, 

Bull. U. S. Geol. Survey No. 540, 1914, p. 534.

6 See E. Poitevin and R. P. D. Graham, Canada Dept. Mines, Museum Bull. No. 27, p. 13,1918.

o Am. Jour. Sci., 3d ser., vol. 24,1S82, p. 3-1; Jour. Geology, vol. 6,1S9S, p. 121. For the minerals associated with Brazilian diamond see E. Hussak, Min. pet. Mitt., vol. 18,1898-99, p. 334; and also in Zeitschr. 

prakt. Geologie, 1906, p. 318. According to Hussak, the minerals of the Brazilian diamond sands are those 

derived from granites, gneisses, and older schists, such as ampbibolite. An im portant earlier paper upon 

Brazilian diamonds is by C. Heusser and G. Claraz, Zeitschr. Deutsch. geol. Gesell., vol. 11,1859, p. 418. 

Two later papers by Derby, relative to the genesis of the diamond, are in Jour. Geology, vol. 19, p. C27, 

1911; vol. 20,1912, p. 451.

' Am. Jour. Sci., 4th ser., vol. 31,1911, p. 480.

e Compt. Rend., vol. 98,1SS4, p. 113. More fully, in Bull. Soc. gdol. France, 3d ser., vol. 14,1885-86, p. 

330. The description of this pegmatite suggests a resemblance to the unakite of Virginia and North 

Carolina.

B Rcpt. Brit. Assoc. Adv. Sci., 1906, p. 562. See also Chem. News, vol. 96,1907, p. M6. According to J. 

A. Thompson (G-eol. Mag., 1909, p. 492), the matrix of the Inverelldiamonds is dolerite. Onesmall diamond 

has been found embedded in the dolerite of Copeton, New South Wales. See L. A. Cotton, I'roc. Linn. Soc., 

New South Wales, vol. 38,1914, p. 803.

113750° 19 Bull. 695 21
322 DATA OF GEOCHEMISTRY. 

diamond, it is not necessary to assume that-the same magma has 

yielded it in all cases. 1

Graphite, Carbon, more or less impure. Rhombohedral. Atomic 

weight, 12; molecular weight probably below that of diamond. 

Specific gravity, .2.255. Atomic volume, 5.5. Hardness, 1 to 2. Color, 

steel gray to black. Fusibility unknown, probably above 3,000°. 

Combustible at temperatures between 650° and 700°.2

Graphite is easily produced artificially. It is a common constituent 

of furnace .slags, being derived from the fuel. On a commercial scale 

it is made by heating coke in the <electric furnace, in which process, 

according to E. G. Acheson,3 a carbide, possibly carborundum, SiC, 

is first formed. 0. Miilhauser 4 lias shown that when carborundum is 

strongly heated the silicon is vaporized, leaving graphitic carbon 

behind. These reactions, connected with Moissan's discovery 5 of carborundum in the Canyon Diablo meteorite, associated with graphite 

and diamond, may have some geological significance. The fact that 

graphite is often found in meteorites proves that it has not necessarily an organic origin, an assumption which is sometimes made.

Graphite has also been prepared by passing vapors of carbon bisulphide or carbon tetrachloride over hot iron, but these processes seem 

to have little or no geologic significance. Whether such substances occur in volcanic emanations is so far a matter of pure speculation. So also is E. Weinschenk's suggestion 6 that metallic carbonyls, rising from great depths, may yield graphite by their decomposition. None of these compounds has been identified in nature, 

and it is more than doubtful whether they could exist at magmatic 

temperatures. J. Walther 7 is inclined to attribute the Ceylon graphite to derivation from carboniferous vapors rising from the interior 

of the earth, and it is possible that hydrocarbons might .yield the 

mineral. M. Diersche, 8 studying the same field, ascribes the formation of the graphite to the infiltration of liquid hydrocarbons and 

their decomposition by heat.

W. Luzi 9 has shown that amorphous carbon can be converted into 

graphite l>y strong heating in melted potash glass containing calcium

1 An excellent monograph on the diamond, by E. Boutan, forms a volume in Fremy's Encyclopedic 

chimique, Paris, 18S6. It concludes with a very 'full bibliography. On diamonds in California, see IT. W. 

Turner, Am. Geologist, vol. .23,1899, p. 182. For a theoretical discussion on the genesis of the diamond, see 

A. Koenig, Zeitschr. Elektrochemie, vol. 12,1900, p. 441.

2 E. Moissan, Compt. Rend., vol. 135,1902, p. 921. On the specific gravity of graphite see H. LeChatelier 

and S. Wologdine, Compt. Rend., vol. 140, 1908, p. 49. On its coefficient of expansion, A. L. Day and 

R. B. Sosman, Jour. Washington Acad. Sci., vol. 2,1912, p. 284. These two papers relate to the deflniteness 

of graphite as a species. On the origin of graphite see H. L. Ailing, Bull. New York State Mus. No. 139, 

1917, p. 141.

3 Jour. Franklin Inst., vol. 147,1899, p. 475. 

«Zeitschr, anorg. Chemie, vol. 5, 1894, p. 111. 

* Compt. Rend., vol. 140,1903, p. 405. 

« Compt. rend. VUI Gong. gSol. internat., vol. 1,1900, p. 447.

i Zeitschr. Deutsch.geol. Gesell.,vol. 41,1889, p. 359. For a full account of (he Coy Ion graphite sec A. 1C. 

Coomara-Swamy, Quart. Jour. Geol. Soc., vol. 56,1900, p. 609. This paper contains a valuable bibliography. 

8 Jahrb. K.-k. geol. Reichsanstalt Wien, vol. 48, 1898, p. 274. 

» Ber. Deutsch. chem. Gesell., vol. 24,1891, p. 4093. Zeitschr. Natimvisscuschaften, vol. r<i, lS;n, p. 224.
ROCK-FORMING MINERALS. 323

fluoride and water. In other words, graphite can occur in a silicate 

magma, either in consequence of its contact with carbonaceous matter 

or as an original constituent brought up from below. In fact, graphite often originates as a product of contact metamorphism. L. 

Jaczewski * regards the Siberian mineral as having been formed by 

just such a transformation of coaly matter in eruptive magmas; but 

there are many occurrences of graphite that can not be accounted for 

in this way. Weinschenk, 2 for example, cites instances of an association of graphite with the higher oxides of iron and manganese, which 

amorphous carbon or the hydrocarbons distilled during contact of a 

magma with coal would reduce to lower forms. In these cases the 

metamorphosis of carbonaceous shales can hardly be assumed.3

From what has been said it is evident that graphite may originate 

in diverse ways, and that in some cases its mode of formation is 

exceedingly obscure. Its commonest occurrences are in the crystalline schists, in which it often seems to replace rnica. Graphitic 

granite, gneiss, mica schist, and quartzite are all well known, and the 

Laurentian limestones of Canada contain large quantities of the 

mineral. The graphite of the adjacent Adirondack region is attributed by E. S. Bastin 4 to the dynamic metamorphism of carbonaceous 

sediments. T. H. Holland,5 however, has described an elseolite syenite 

from India in which graphite appears to be an original mineral; and 

Moissan 6 examined a pegmatite of unknown locality and reached a 

similar conclusion. Graphite is also found in the iron-bearing basalts 

of Ovifak, Greenland, embedded in feldspar and associated with 

native iron.7 Graphite, then, sometimes appears as a direct separation from a magma, under conditions which preclude the supposition 

of an organic origin, or interpretation as a result of metamorphic 

action.

NATIVE METALS.

Native iron, Isometric. Atomic weight, 55.9; molecular weight 

unknown. Specific gravity, 7.3 to 7.8, dependent upon the impurities. Atomic volume, 7.2. Color, steel gray to black. Malleable. 

Luster, metallic. Hardness, 4 to 5. Magnetic.

1 NC-JCS Jahrb., 1901, Band 2, ref., p. 74.

2 Compt. rend. VIII Cong. g<5ol. internat., vol. 1,1000, p. 447.

3 On the formation of graphite in certain soils see W. Heinisch, Sitznngsb. K. Akr.d. Wiss. Wicn, vol. 120, 

Abth. II b, 1911, p. 85.

4 Econ. Geology, vol. 5,1910, p. 134. On Canadian graphite see volume by F. Cirkcl, published by the 

Dept. of Mines, Mines Branch, Canada, 1907.

6 Hem. Geol. Survey India, vol. 30,1901, p. 201.

«Compt. Rend., vol. 121,1895, p. 538.

' See K. J. V. Steenstrup, Mineralog. Mag., vol. C, 1884, p. 1; and J. Lorenzen, idem, p. 14. Graphite 

from inclusions in basalt is also described by R. Brauns, Centralbl. Miii., Geol.u. Pal., 1908, p. 97. On 

inorganic graphite from Lapland, see O. Stutzer, idem, 1S07, p. 433. In Zeitschr. prakt. Geologic, 1910, 

p. 10, Stutzel has a long article on graphite deposits and their origin. See also A. N. Wir.chcl), Econ. 

Geology, vol. 6,1911, p. 218. On the graphite of southeastern Pennsylvania, of metamorphic origin, soo 

B. L. Miller, Econ. Geology, vol. 7,1912, p. 762. On the conversion of amorphous carbon into graphileseo 

C. W. Arsem, Jour. Ind. Eng. Chem., vol. 3,1911, p. 799.
324 DATA OF GEOCHEMISTRY.

;

Minute grains of native iron are not uncommon in certain eruptive 

rocks, especially in basalts. They were first identified by T. Andrews* 

in the basalt of Antrim, Ireland. More recently they have been found 

by G. H. Cook 2 in the trap rocks of New Jersey; by G. W. Hawes 3 in * 

the dolerite of Dry River, near Mount Washington, New Hampshire; 

by F. Navarro 4 in the basalt of Gerona, Spain; and by F. F. Hornstein 5 in basalt near Cassel, Germany. In the New Hampshire 

locality they occur inclosed in grains of magnetite, suggesting a 

secondary derivation of the latter mineral from the metal. There are 

also a number of other European occurrences.6 E. Hussak 7 found * 

particles of native iron in an auriferous gravel in Brazil; and A. 

Daubree and S. Meunier 8 have described small masses of the metal 

from gold washings near Berezovsk, in the Ural. These masses were 

notable because of the fact that they contained traces of platinum 

but no nickel. Their specific gravity was 7.59.

The most remarkable occurrence of native iron, however, is that « 

discovered by A. E. Nordenskiold 9 in 1870, at Ovifak, Disco Island, 

Greenland. Here large masses of iron, up to 20 tons in weight, had 

been weathered out like boulders from the basalt, and in the rock 

itself lenticular and disklike pieces of the metal were still embedded. 

At first the iron was thought to be meteoric, but it has since been 

proved to be of terrestrial origin. 10 In nearly all respects it resembled 

meteoric iron, for it gave the Widmannstatten figures when etched, 

contained iron chloride, and was associated with magnetic pyrites *" 

and graphite. Schreibersite, the iron phosphide, which is common in > 

meteorites, is, however, absent from the Ovifak masses. In the 

sample examined by Moissan u graphite, amorphous carbon, and 

grains of corundum were found. '

This Ovifak iron is somewhat variable in composition, as the 

numerous analyses of it show.12 The following analyses by J. Lawrence Smith are enough to indicate its general character:

i Kept. Brit. Assoc., 1852, pt. 2, p. 34.

3 Ann. Kept. Geol. Suivey New Jersey, 1874, p. 56.

s Am. Jour. Sci., 3d ser., vol. 13,1877, p. S3.

« Geol. Centralbl., vol. 7,1905, p. 184.

G Centralbl. Min., Geol. u. Pal., 1907, p. 276.

6 Sec for example, A. Schwantke, Centralbl. Min., Geol. u. Pa!., 1901, p. 65, and M. Seebach, idem, 1910, ' 

p. 041.

' Bol. Comm. geog. e geol. Sao Paulo, No. 7,1890, p. 14. \.

B Compt. Rend., vol. 113,1891, p. 172.

» Geol. Mag., 1872, 460, 516.

'" There is abundant literature on this subject. See especially K. J. V. Steenstrup, Mineralog. Mag., 

vol. 6,1884, p. 1; J. Lorenzen, idem, p. 14; J. Lawrence Smith, Annales chim. phys., 5th ser., vol. 16,1879, 

p. 452; and A. Daubree, Etudes synthe'tiques de geologic exp4rimentale, 1879, p. 555.

11 Compt. Rend., vol. 116,1S93, p. 1269.

1J See the memoirs, already cited, by Nordenskiold, Lorenzen, and Smith. Also E. S. Dana, System of. * 

mineralogy, 6th ed., p. 28.
ROCK-FORMING MINERALS. 325

Analyses of native iron from Ovifak, Greenland.

A. External oxidized coating of a large mass. Specific gravity, 5. 

B. Particles of iron from interior of the mass A. Specific gravity, 0.42. 

C. Malleable nodule from dolerite. Specific gravity, 7.-10. 

D. An inegular mass. Specific gravity, 6.80.

Fe.,0, ..........................................

Fe:..3............ .............................

NL. ........... ................................

Co.............................................

Cu.. ............. ..............................

S..... ....

P.............................................

C............... ............................... c\.. ............................................

MgO. ..........................................

Ri02 .. .........................................

Silicates. .......................................

H,0.............................. ............

A

76. 21

16.56

1.08

.48

.08

1.12

14

1.36

4.50

101. 53

B

93. 16

2.01

.80

.12

.41

.32

2.34

.02

99.18

C

90. 17

G.50

7Q

.13

1. 54

99. 13

D

88.13

2.13

1.07

.48

.36

.25

2.33

.08

Trace.

4.20

99.03

The terrestrial nature of this iron is abundantly proved by the 

observations of Steenstrup, who found it disseminated throughout 

large bodies of basalt in place. It is, therefore, a part of the rock 

itself, but concerning its origin there has been much discussion. Was 

it present in the original magma or reduced by carbonaceous matter 

on its way up from below? The latter supposition is admissible, 

for Daubree, 1 by fusing a Iherzolite with carbon, obtained pellets of 

metallic iron, containing nickel and almost identical in composition 

with the specimens from Greenland. Furthermore, as Daubr6e 

observes, beds of lignite are found on Disco Island, and graphite is 

closely associated with the native iron. The other alternative, however, is not excluded from consideration, and it may be that the iron 

came as such from great depths below the surface to teach us that 

the earth is essentially a vast meteorite and that its interior is rich 

in uncombined metals.2 If the reduction theory held, we should 

expect to find similar occurrences of native iron wherever basalts or 

peridotite had penetrated carbonaceous strata. The rarity of the 

substance would seem to indicate a profounder origin.

In several localities metallic grains or nodules which approach 

native nickel in composition have been found in gravels. In meteorites the nickel rarely exceeds 6 or 7 per cent, but in these terrestrial 

products its proportion is usually much higher. From the drift of 

Gorge River on the west coast of New Zealand W. Skey 3 obtained

1 Etudes synthe'tiqucs de geologic cxperimentale, 1879, pp. 517,574.

2 See also E. B. de Chancourtois, Bull. Soc. geol. France, vol. 29,1872, p. 210. C. Winklcr (Ber. Math, 

phys. Classe, K. siichs. Gesell. Wiss., Febraary 5,1900) suggests that iron and nickel may have been brought 

npfrom below as carbonyls, Ni(CO)4, Fe(CO) 5 , and Fe2 (CO)7 compounds which decompose easily, depositing their metals in the free state. Compare Wcinschenk's suggestion as to graphite, ante, p. 322.

s Trans. New Zealand tost., vol. 18,1885, p. 401.
326 DATA OF GEOCHEMISTRY.

grains of this character, which were associated with magnetite, tinstone, native platinum, etc. This awaruite, as Skey named it, is 

derived, according to Go H. F. Ulrich, 1 from neighboring serpentines 

or peridotites. The josephinite of W. H. Melville 2 from placer gravels 

in Josephine and Jackson counties, Oregon, forms pebbles up to several grams in weight and also occurs near large masses of serpentine. 

Its specific gravity is 6.204. In the sands of the Elvo, near Biella, 

Piedmont, A. Sella 3 found minute grains of a similar substance, but 

its geological origin was not determined. Their specific gravity was 

7.8. Souesite consists of similar grains, found by G. C. Hoffmann 4 

in sands of the Fraser River, in British Columbia. They were associated with native platinum, iridosmine, gold, etc., and had a specific 

gravity of 8.215. These grains are doubtless derived from pcridotite. Still more recently a similar nickel iron from the south fork of 

Smith River, Del Norte County, California, has been described by 

G. S. Jamieson,5 who has also reexamined the mineral from Oregon. 

The analyses are as follows:

Analyses of nickel iron.

A. Awaruite, Skcy. B. Josephinitc, Melville. C. JosepMnite, Jamieson. D. Del Kbrto County, 

Jamieson. E. Souesitc, Hoffinann. F. Piedmont. Analyzed for Sella by Mattirolo.

Ni.. .........................

Co...........................

Fe

Fe7S8 - .--. ................

Cu

As...........................

P...........................

Clu'omite and magnetite. ......

SiOa ........ .................

Silicates. ..................... 

Insoluble. ....................

MgO... ......................

H2O at 100°.....-. ...........

H2O above 100°...............

01........................*...

C02 ..........................

Volatile matter ...............

A

67.63

.70

31.02

.22

.43

100. 00

13

GO. 45

.55

23.22

.55

.50

.23

.12

12.26

.81

1.12

.04

Trace.

.70

100. 55

c

68.61

1.07

19.21

.05

.59

.04

.10

"9.45

.50

99. 62 ;

D

68. 46

1.07

18.97

.05

.56

04

1Q

Q Q7

AA

99. 75

v

75.50

"WoTlP

99 09

1 90

1.16

99. 88

F

75.2

26.6

101. 8

1 Quart. Jour. Gcol. Soc., vol. 4G: 1890, p. C19.

2 Bull. U. S. Geol. Survey No. 113,1893, p. 54.

a Compt. Rend., vol. 112,1S91, p. 171.

« Am. Jour. Sci., 4th scr., vol. 19,1905, p. 319.

B Idem, p. 413. Jamieson urges that the original name awaruite should bo used for all these irons. 

Awaruite is also reported from the Yukon by E. A. A. Johnston, Summary Kept. Geol. Survey Canada, 

1910-11, p. 256.
ROCK-FORMING MINERALS. 327

The silicate in Melville's analysis was mainly serpentine, with what 

appeared to be an impure bronzite. The probable derivation of the 

nodules from peridotite is thus materially emphasized. With these 

substances two meteorites only, or supposed meteorites, can be compared. That found in an Indian mound in Oktibbeha County, Mississippi, contained 59.69 per cent Ni and 37.97 per cent Fe; and that 

from Santa Catarina, Brazil, carried 63.69 Fe with 33.97 Ni. These 

masses, however, are only presumably, not certainly, meteoric.

Occasionally native iron is found of secondary origin produced by 

the obvious reduction of iron compounds. On North Saskatchewan 

River, 70 miles from Edmonston, beds of lignite have burned, reducing the neighboring clay ironstone to metallic iron. According to 

J. B. Tyrrell, 1 masses of iron which weigh from 15 to 20 pounds can 

be picked up in this locality. G. C. Hoffmann 2 has described spherules of iron in limonite, found in fissures in quartzite on St. Josephs 

Island, Lake Huron; and again from a pegmatite of Cameron 

Township, Ontario.3 The exact origin of these Canadian irons is 

not clear. Finally, E. T. Alien 4 has analyzed soft, malleable iron 

from borings at three points in Missouri, where it occurred in sedimentary rocks not far from beds of coal. The following analyses 

of these products will serve to show the great difference between them 

and the supposedly magnetic irons described in the preceding pages:

Analyses of native iron of secondary origin.

A. From St. Josephs Island, Hoffmann. Specific gravity, C.S012.

B. From Cameron Township, Ontario. Analysis by Johnstou for Hofimann. Specific gravity, 7.257.

C. From Caineron, Missouri, Alien.

D. From Weaubleau, Missouri, Alien.

E. From Holden, Missouri, Alien.

Fe. .................................

Ni...................................

Co...................................

Mn.................................

Cu.......... .........................

8.. ...................................

P...................................

c. ...................................

SiO2 .. ...............................

Insoluble. ............................

A

88.00

.10

.21

.51

.09

.12

.96

(?)

9.76

Undet.

99.75

B

90.45

Trace.

.75

None.

Undet.

Undet.

7.2Q

98.46

C

90.16

.207

.065

.37

99. 802

33

99.39

Undet.

.13

.31

99. 83

E

97. 10

Undet.

.176

1.65

98. 926

1 Am. Jour. Sci., 3d ser., vol. 33,1SS7, p. 73.

3 Trans. Roy. Soc. Canada, vol. 8, pt. 3,1890, p. 39.

a Ann. Rept. G eol. Survey Canada, vol. 6,1895, p. 23 R.

< Am. Jour. Sci., 4th ser., vol. 4,1897, p. 89. Other occurrences of naturally reduced iron arereported by 

A. A. Inostranzeff, Geol. Zentralbl., 1908, p. 611, from Russian Island, near Vladivostok, and by K.Pfiwosnik, Oestorr. Zeitschr. Berg- u. Hiittcnw., vol. 58,-191.0, p. 327, from Shotley Bridge, England. On iron 

formed under peat by the reduction of bog iron ore see A. E. KupfFor, Chem. Zentralbl., 1913, p. 55.
328 DATA OF GEOCHEMISTRY.

Not only iron but other native metals may occur as primary constituents of igneous rocks. Platinum, with its companions, osmium, 

iridium, rhodium, ruthenium, and palladium, are associated with 

chromite and olivine in peridotites.1 W. Moricke 2 has found primary gold in a pitchstone from Guanaco, Chile, and G. P. Merrill 3 

has described a granite from Sonora in which it also appears. Still 

other examples are cited by R. Beck.4 The metallic constituents of 

magmas, however, have received very little attention so far, and their 

number may be greater than it is now supposed to be.

SULPHIDES.

Pyrite. Isometric. Composition, FeS2 . Molecular weight, 120. 

Specific gravity, 4.95 to 5.10. Molecular volume, 24. Color, brassyellow; luster, metallic. Hardness, 6 to 6.5.

Pyrrhotite. Hexagonal and orthorhombic. Two modifications are 

known. Composition uncertain, varying from Fe7S8 to FeuS12 . 

Specific gravity, 4.6. Color, bronze-yellow to copper-red; luster, 

metallic. Magnetic. Hardness, 3.5 to 4.5. Whether troilite, FeS, 

which is a common mineral in meteorites, is identical with pyrrhotite 

or not is a disputed question.5

Both pyrite and pyrrhotite are common though minor accessory 

constituents of igneous rocks. Pyrite is found under a great variety 

of associations, but pyrrhotite is more characteristic of the ferromagnesian varieties, such as gabbro, diabase, diorite, and basalt.

Pyrrhotite has been observed as a furnace product, and both species 

can be made artificially by various processes. Those which explain 

the formation of sulphides in sedimentary rocks will be considered 

in another connection, but the following experimental data bear upon 

their occurrence in igneous formations.

J. Durocher,6 by mingling the vapor of iron chloride with hydrogen 

sulphide in a porcelain tube heated to redness, obtained small crystals 

of pyrite. By heating magnetite to whiteness in hydrogen sulphide, 

T. Sidot 7 produced crystals which appeared to be identical with 

troilite. Troilite was also formed by R. Lorenz,8 who heated iron 

to redness in a stream of H2S. C. Doelter, 9 on the other hand, by 

the same reaction, and also with amorphous ferric oxide or hematite

i See J. F. Eemp, Bull. U. S. Geol. Survey No. 193,1902, for a complete summary of our knowledge concerning native platinum, with many bibliographic references, 

s Min. pet. Mitt., vol. 12,1891, p. 195.

3 Am. Jour. Sci., 4th ser., vol. 1,1896, p. 309.

4 Lehre von den Erzlagerstatten, 2d ed., 1903. See also W. I-I. Weecl,-Eng. and Min. .Tour., vol. 77,1904, 

p. 440, and R. W. Brock, idem, p. 511.

aSee S. Meunier, Annales chim. phys., 4th ser., vol. 17, 1S69, p. 36, and G. Linck, Ber. Deutsch. chem. 

Gesell.,vol.32,1899, p. 895.

«Compt. Rend., vol. 32, 1851, p. 823. For an earlier synthesis of pyrite see F. WohlerLiebig'sAnnalen, 

vol. 17, p. 260,1836.

' Idem, vol. 66,1868, p. 1257.

s Ber. Deutsch. chem. Gesell., vol. 24,1891, p. 1504.

»Zeitschr. Kryst. Min., vol. 11,1886, p. 30.
ROCK-FORMING MINERALS. 329

instead of metallic iron, obtained pyrite. When ferrous carbonate 

or sulphate was used, troilite was formed. All of these methods are 

general. With other metals or their salts other crystallized sulphides/ 

identical with natural minerals, can be produced. In brief, gases or 

vapors which exist in volcanic exhalations can so react upon one 

another as to develop crystalline sulphides. The latter appear in or 

upon the solidified rocks, but preferably in rocks which have cooled 

under pressure. By pressure the reacting vapors are confined within 

the magma, and can not readily escape.

Metallic sulphides, fairly crystallized, can also be formed in the wet 

way, when appropriate mixtures are heated together in sealed tubes. 

H. de Senarmont * heated various metallic solutions with hydrogen 

sulphide or alkaline sulphides in this manner with great success, and 

when iron salts were taken pyrite was formed. C. Geitner 2 also obtained pyrite by heating powdered basalt with water and sulphurous 

acid to 200°. Doelter 3 prepared pyrite by heating hematite, magnetite, or siderite with hydrogen sulphide and water for 72 hours to 

80° or 90°. When the same investigator 4 heated ferrous chloride 

with sodium carbonate, water, and Hydrogen sulphide for 16 days to 

200° he obtained pyrrhotite, provided that air was excluded from his 

tubes. In presence of air pyrite was formed.

According to W. Feld,5 when iron salts are precipitated by an 

alkaline polysulphide, ferrous sulphide and sulphur are thrown down. 

If the solution is then neutralized, or made very feebly acid, and 

boiled, the precipitate is rapidly transformed into the bisulphide. 

Alkaline substances retard or hinder the transformation, reducing 

agents hasten it. In. all formations of pyrite by the wet way the 

monosulphide seems to be first produced. In a still more elaborate 

investigation E. T. Alien, J. Johnston, J. L. Crenshaw, and E. S. 

Larsen 6 report that pyrrhotite is formed by the direct union of iron 

and sulphur and also by the dissociation of pyrite in an atmosphere 

of H2S at a temperature of 550°. At 575°, the reverse change takes 

place, and pyrite is again formed. Pyrrhotite exists in two modifications, hexagonal below 138°, orthorhombic above that transition 

temperature. The variation of pyrrhotite from troilite is ascribed to 

the presence of sulphur in "solid solution'' in the monosulphido.7 

In meteorites the excess of metallic iron renders the formation of pure 

troilite possible.

1 Compt. Rend., vol. 32,1851, p. 409.

~ Ann. Chem. Pharm., vol. 129,1864, p. 350.

a Zcitschr. Kryst. Min., vol. 11,1886, p. 30.

«Min. pet. Mitt., vol. 7,1885-86, p. 535.

6 Zeitschr. angew. Chemie, vol. 24,1911, p. 97.

e Yearbook Carnegie Inst. Washington, 1910, p. 104; Am. Jour. Sci., 4th ser., vol. 33, p. 169,1912. Many 

references to literature are given. See also Alien, Jour. Washington Acad. £ci., vol. 1, p. 170,1911; and 

Alien and Crenshaw, Am. Jour. Sci., 4th ser., vol. 38, p. 393,1914. On the dissociation pressures of pyrite 

and covellite. See E. T. Alien and R. H. Lombard, Am. Jour. Sci., 4th ser., vol. 43,1917, p. 175.

 ' Tho variation may possibly be due rather to admixtures of a higher sulphide of iron,.Fe2S3 or FeaSi,' 

compounds which are not definitely known but are theoretically rational.
830 DATA OF GEOCHEMISTRY.

Pyrite was produced by Alien and his colleagues not only from 

pyrrhotite, but als'o by the action of hydrogen sulphide upon solutions 

of iron. From acid solutions, at 100°, under pressure, its relatively 

unstable isomer, marcasite, was formed. Warmer alkaline solutions 

yielded pyrite. At 450° marcasite is transformed into pyrite, 

and therefore it can not occur as a magmatic mineral. Marcasite 

is only found in sedimentary formations and metalliferous veins. 

Fossil shells consisting entirely of marcasite are well known, and intermediate mixtures of pyrite and marcasite are common. The two 

species probably differ in molecular arrangement, but the evidence 

upon this point is far from conclusive. Various structural formulae 

have been proposed for them, but none has been definitely established.1

Pyrrhotite and marcasite both alter into pyrite and all three species 

alter into limom'te, goethite, hematite, and sulphates of iron. Perfect 

pseudomorphs of limonite after pyrite are common. 2

Another modificatibn of FeS2, black and amorphous, has been described by B. Doss,3 who names it melnikovite.

Each of these synthetic processes finds some equivalent in nature. 

Dry gases, wet gases, and alkaline solutions charged with hydrogen 

sulphide can assist in producing the minerals which are now under 

consideration, with other rarer species of the same class. The magmas contain the reagents, and the reactions, or reactions like those 

just described, naturally follow. In most cases the sulphides appear 

as secondary minerals, but they are sometimes primary. J. H. L. 

Vogt 4 has shown that sulphides are actually soluble in silicate magmas, especially at the higher temperatures, and that they are among 

the earliest minerals to crystallize. Certain of the pyrrhotite deposits 

of Norway he regards as the direct products of magmatic segregation.

Several other sulphides occasionally appear as primary minerals 

in igneous rocks. Molybdenite, MoS2 , is common in granites, and 

J. F. Kemp;5 in a pegmatite dike in British Columbia, found masses

1 See E. Weinschenk, Zeitschr. Kryst. Min., vol. 17,1890, p. 501; A. P. Brown, Proc. Am. Philos. Soc., vol. 

33,1891, p. 225; and H. N. Stokes, Bull. U. S. Gcol. Survey No. 186,1901. Stokes describes many elaborate 

experiments upon the relative solubility of pyrite and marcasite in chemical reagents. See also G: W. 

Plummer, Thesis, Univ. Pennsylvania, 1910, and W. H. Goodchild, Mining Mag., vol. 16,1917, p. 253.

2 For a full discussion of the alterations of pyrite see A. A. Julien, Annals New York Acad. Sci., vol. 3, 

1886, p. 365; vol. 4,1887, p. 125. A paper on the origin of pyrite, by A. R. Whitman, is in Econ. Geology, 

vol. 8,1913, p. 455.

a Neues Jahrb., Boil. Band 33,1912, p. C62.

4 Die Silikatschmclzlosiingen, pt. 1,1903, p. 96. See also Zeitschr. prakt. Geologic, 1898, p. 45; and Trans. 

Am. Inst. Min. Eng., 1901, p. 131. For sulphides in slags, see J. H. L. Vogt, Mineralbildung in Schmelzmassen, Christiania, 1892. See also J. E. Spurr, Trans. Am. Inst. Min. Eng., vol. 33,1903, p. 306, on Alaskan 

pyrrhotite. A remarkable peridotite at East Union, Maine, containing 21.5 per cent of pyrrhotite, is 

described by E. S. Bastinin Jour. Geology, vol. 16,1908, p. 124.

e Trans. Am. Inst. Min. Eng., vol. 31,1901, p. 182. See also W. H. Emmons, Bull. U. S. Geol. Survey 

No. 432,1910, p. 42, on molybdenite in the granites of Maine. E. Brauns (CentralbL Min., Gcol. u. Pal., 

W08, p. 97) found molybdenite in inclusions in basalt. 0. Stutzer (Zeitschr. prakt. Geologic, 1907, p. 371) 

has described magmatic bornite from South Africa. Chalcopyrite and bornite as primary minerals in a 

monzonitic dike near Apex, Colorado, have been reported by E. S. Bastin and J. M. Hill. Econ. Geology, 

vol. 6, p. 468,1911. See also E. Howe, Econ. Geology, vol. 10,1915, p. 298.
ROCK-.FOEMHSTG MINERALS. 33.1

of bornite, which appeared to be an original constituent of the rock. 

In the augite syenite of Stoko, near Brevik, Norway, the arsenide, 

lollingite, FeAs2 , appears to have crystallized before the feldspar. 

The pegmatites of that region, as described by W. C. Brogger, also 

contain molybdenite, zinc blende, pyi'ite, galena, and chalcopyrite.1 

Some of these occurrences, and many occurrences of pyrite also, are 

doubtless secondary.

FLTJOBIDES.

Fluorite. Isometric. Composition, CaF2 . Molecular weight, 78.1. 

Specific gravity, 3.18. Molecular volume, 24.5. Hardness, 4. Colorless, yellow, red, blue, green, purple, violet, etc.

Fluorite, although most abundant as a vein mineral and in sedimentary formations, is also found as a minor accessory in granite, 

gneiss, quartz porphyry, syenite, elaeolite syenite, and the crystalline 

schists. W. C. Brogger 2 reports it, both as an early separation in 

the augite syenites of Norway and also as a contact mineral. It 

sometimes appears on volcanic lavas as a sublimation product, or as 

the result of the action of fmoriferous gases upon other minerals.3 It 

is also produced as a secondary mineral from the decomposition of 

various fluosilicates. It alters into calcite, being attacked by percolating waters containing calcium bicarbonate or alkaline carbonates. 

Crystallized calcium fluoride has been prepared by several processes, 

but they shed little light upon its presence in igneous rocks.4

Several other fluorides are found associated with granites or pegmatites, such as tysonite, fluocerite, yttrocerite, etc. More important 

by far is the mineral cryolite, which forms a large bed in Greenland. 

According to F. Johnstrup,5 it is a concretionary secretion in eruptive 

granite. A more recent writer, R. Baldauf,8 regards the cryolite as 

having been formed by the action of fluoriferous gases upon the 

original granitic magma. Cryolite is also found sparingly at Miask, 

in the Urals, and in the granites of Pikes Peak, Colorado.7 It is ft 

double fluoride of aluminum and sodium, Na3AlFe . Fluorine compounds, it must be observed, are rarely found in eruptive rocks.

i See Zeitschr. Kryst. Min., vol. 16, pt. 2, 1890, pp. 5-11. For very complete analyses of .Norwegian 

pyrite see E. Boettker, Rev. ge"n. chim. pure ct app., vol. 9, p. 323. On magmas and sulphide ores sec A. P. 

Colcnian, Econ. Geology, vol. 12,1917, p. 427.. Also C. F. Tolmau and A. F. Rogers, Magmatic sulphide 

ores: Lcland .Stanford Jr. Univ., University series, 1916.

a Zeitschr. Kryst. Min., vol. 16, pt. 2,1S90, p. 56.

3 Idem, vol.<7,1883, p. 630. Abstract of memoir by A. Scacchi. For a study of the gases occluded by 

fluorite see H. W. Morse, Proc. Am. Acad., vol. 41,1906, p. 587. According to H. Becqucrcl and H. Moissan 

(Bull. Soc. chim., 3d ser., vol. 5, 1891, p. 154) free fluorine is sometimes present. W. J. Humphreys. 

(Astrophys. Jour., vol. 20, 1904, p. 266) found spectroscopic traces of yttrium and ytterbium in many 

fluorspars. G. Urbain (Compt. Rend., vol. 143,1906, p. 826) also found terbium, gadolinium, dysprosium, 

and samarium.

4 See the works by Brauns, Bourgeois, and Fouque" and Xevy cited else where, in this chapter.

0 Cited by F. Zirkc], Lehrbuch der Petrographie, vol. 3, p. 444. The original memoir by Johnstrup is 

not within my reach.

6 Zeitschr. prakt. Geologic, 1910, p. 432. Baldauf gives a good description of the rarer minerals associated 

with the cryolite. See also O. B. BSggild, Zeitschr. Kryst. Min., vol. 51,1913, pp. 591, G14.

'W. Cross and W. F. Hillebrand, Bull. U. S. Geol. Survey No. 20.
332 DATA OF GEOCHEMISTRY.

They are especially characteristic of the deep-seated or plutonic 

rocks, where the gaseous exhalations have been retained under pressure, and are commonly regarded as of pneumatolytic origin.

CORUNDUM.

Rhombohedral. Composition, aluminum oxide, A1203 . Specific 

gravity, 3.95 to 4.10; of the purest material, 4.0; molecular weight,1 

102; molecular volume, 25.5. Colorless when pure, but ordinarily 

colored yellow, gray, green, red, or blue by traces of impurity. 

Emery is a mixture of corundum with magnetite or hematite, and 

sometimes spinel.2 Fusible at 2; 050° C., according to C. W.Kanolt.3 

Hardness, 9, thus ranking among natural minerals next to diamond.

Crystallized alumina, artificial corundum, has been produced by 

various methods. These are well summarized in the works of Bourgeois and Fouque" and Levy, and in the memoir by J. Morozewicz.4 

They may be briefly grouped as follows: First, by direct fusion of 

amorphous alumina. Second, by the crystallization of alumina from 

solution in various molten fluxes, such as potassium bichromate, 

sodium molybdate, borax, lead oxide, etc. Most of these processes 

find no equivalent in nature. Third, by the decomposition of aluminum chloride or fluoride by water at high temperatures methods 

which may shed some light upon the formation of corundum as a 

contact mineral, or as a constituent of metamorphic rocks. In some 

of these reactions boric acid plays a part. Fourth, by the decomposition of other minerals, such as muscovite. Finally, by crystallization 

of artificial magmas.

It is not necessary for our purposes to examine these processes in 

detail. It is enough to select from among them those which seem to 

be the most significant. P. Hautefeuille and A. Perrey,5 for example, 

dissolved alumina in melted nepheline, and found that upon cooling 

the greater part of it crystallized out as corundum. The association 

of corundum with certain nepheline syenites can be rationally studied 

in the light of this observation. With leucite a similar result was 

obtained; but an artificial potassium nepheline gave no similar reaction. A. Brun 6 prepared corundum, together with anorthite, by 

heating a mixture of 40 parts silica, 37 lime, and 120 alumina to 

whiteness for three hours. Fusion of the mixture, however, gave

1 The ordinary rounded-off atomic weights may be used for computations of molecular weights and 

volumes.

2 On emery see G. S. Rogers, Annals New York Acad. Sci., vol. 21,1911, p. 11.

8 Jour. Washington Acad. Sci., vol. 3,1913, p. 315. Other determinations of the melting point are: Hem-, 

pel, 1,880°; Moissan, 2,250°; and Ruff, 2,010°.

* Fouque' and L6vy, Synth&se des mindraux et des roches, Paris, 1882. L. Bourgeois, Reproduction artificiclle des mindraux, in Fremy's Encyclopedic chimique, vol. 2, 1st appendix. Morozewicz, Min. pet. 

Mitt., vol. 18,1898, p. 23.

6 Bull. Soc. min., vol. 13, 1890, p. 147.

e Arch. sci. phys. nat, 3d ser., vol. 25, 1S91, p. 239.
EOCK-FOBMING MINERALS. 333

him only glass. When the alumina was reduced to 23 parts, zoisite 

was formed. W. Bruhns * obtained corundum in the wet way by 

heating alumina for 10 hours to 300° in a platinum tube with water 

containing a trace of ammonium fluoride; but at 250° no crys.tallization took place. By similar reactions hematite, quartz, tridymite, 

and ilmenite were prepared. These experiments strengthen the supposition that the fluorine compounds contained in volcanic exhalations may assist the natural formation of the minerals named. P. 

Hautefeuille's synthesis of corundum 2 by the action of moist hydrofluoric acid upon alumina at a red heat is another illustration of the 

same principle. It is typical of a considerable number of mineral 

syntheses. That the fluorides are not essential to the formation of 

corundum, however, is shown by the experiments of G. Friedel.3 

When amorphous alumina is heated to 450-500° with a solution of 

soda, corundum and diaspore, HA102 , are both produced. At 530- 

535° corundum alone formed, and at 400° only diaspore. If the 

alumina contained a little silica, crystals of quartz appeared. By a 

similar reaction between ferric hydroxide and soda solution, Friedel 

obtained crystals of hematite. E. S. Shepherd and G. A. Rankin * 

converted precipitated alumina into crystalline corundum by simple 

heating at about 200°.

From a geological standpoint some very important experiments 

upon the genesis of corundum are those of Morozewicz,5 who studied 

the conditions of its deposition from a cooling magma. He worked 

with artificial magmas upon a rather large scale, using the furnaces 

of a glass factory in preparing his melts; and he found that whenever the alumina, in comparison with the other bases, exceeded a certain ratio, the excess, upon cooling the fused mass, crystallized out 

completely either as corundum, as spinel, as sillimanite, or as iolite.6 

The qualifying conditions a~re as follows:

An alumosilicate magma in which the molecular ratio of the 

bases CaO, K20, Na20 is to A1203 as 1:1 is said to be saturated with 

respect to alumina. If more alumina is present, the magma is supersaturated, and the excess will be deposited as one or another of the 

above-named minerals. If we write the general formula for the 

magma of RO.mAl203.ft<Si02 the following rules are found to apply: 

First, if magnesia and iron are absent, and the value of n lies between 

2 and 6, the excess of alumina will crystallize wholly as corundum; 

but if n is greater than 6, sillimanite, or sillimanite and corundum, 

will form. With magnesia or iron present in an amount above 0.5 

per cent, and with n < 6, spinel is produced, or spinel and corundum

> Neues Jahrb., 1SS9, Band 2, p. 62.

2 Annales chim. phys., 4th ser., vol. 4, 1865, p. 153.

s Bull. Soc. min., vol. 14,1891, p. 8.

« Am. Jour. Sci., 4th scr., vol. 28,1909, p. 321.

* Min. pet. Mitt., vol. 18,189S, pp. 22-83.' Also Zcitschr. Kryst. Min., vol. 24,1895, p. 281.

o CordJerite. The name iolite has priority and is given preference by Dana.
334 DATA OF GEOCHEMISTRY.

together. With n>Q, the magnesia and the excess of alumina will 

go to form iolite, or iolite and spinel. In each case the alumina in 

excess of the ratio RO : A1203 :: 1 :1 is completely taken up in the 

formation of the several species named. The balance of the alumina 

the normal alumina, so to speak will obviously appear in other minerals, such as anorthite, nepheline, alkali feldspars, etc., whose nature 

will depend upon the bases which happen to be associated with it, and 

also upon the proportion of silica.

Previous to the appearance of Morozewicz's memoir it was commonly supposed, but without good reason, that corundum was not a 

true pyrogenic mineral. It was best known as occurring with metamorphic rocks, and especially in limestones; and it had been observed 

as a product of contact action, although rarely. 1 When corundum 

was found in igneous rocks it was regarded as derived from accidental inclusions, and not as a primary separation from the magma. 

The work of Morozewicz modified these beliefs and shed new light 

upon the problems of petrology. The common association of corundum with spinel, iolite, sillimanite, andalusite, and kyanite. afc once 

became significant, and in accordance with the rules developed by 

Morozewicz.

Pyrogenic corundum, according to A. Lagorio,2 is found in alumosilicate rocks only when the latter contain over 30 per cent alumina, 

and such rocks are rare. Lagorio cites analyses of several examples, 

and Morozewicz 3 himself describes others. Kyschtymite is an anorthite rock containing up to 59.5 per cent of corundum; a corundum 

syenite with 18.5 per cent consists largely of orthoclase and albite, 

and a corundum pegmatite with 35.4 per cent has similar composition. All these rocks are from the Ural Mountains. A corundum, 

anorthosite analogous to kyschtymite has been described by W. G. 

Miller 4 from Canada; and corundum-bearing nepheline syenites, 

according to A. P. Coleman,5 are also found in the same region. In 

the Coimbatore district, Madras Presidency, India, T. H. Holland 6

' K. Busz (Gcol. Mag., 1896, p. 492) found corundum in contacts between granite and clay slate on Dartmoor in Devonshire. A. K. Coom&ra-Swamy (Quart. Jour. Gcol. Soc., vol. 57,1901, p. 185) observed it at 

contacts between granite and micaceous quartzite near Morlaix, France. The corundum was there associated with sillimanite, andalusite, spinel, etc. On an occurrence of corundum in basalt see E. Schiinnann, 

Sitzungsb. naturhist. Ver. preuss. Rheinlande u. "VVcstfalens, 1911, pt. 2, p. 63 A.

2 Zeitscbr. Kryst. Min., vol. 24,1895, p. 285. This memoir contains abundant literature references upon 

the occurrence of corundum in igneous rocks.

8 Min. pet. Mitt., vol. 18,1898, pp. 212,219. For present purposes the minor accessory minerals in these 

rocks may be ignored.

< Am. Geologist, vol. 24,1899, p. 276.

6 Jour. Geology, vol. 7, 1S9D, p. 437. A syenite from Montana, containing 31 per cent of corundum has 

been described by A. F. Rogers, Jour. Geology, vol. 19,1911, p. 748.

 Mem. Geol. Survey India, vol. 30, 1901, pp. 20], 205. For Indian corundum in general, see Holland, 

Manual of geology of India, Economic geology, pt. 1; F. R. Mallet, Roc. Geol, Survey India, vol. 5,1S72, 

p. 20; vol. 6,1873, p. 43; and C. S. Middlemiss, idem, vol. 29,1896, p. 39. Mallet describes beds of corundum 

in gneiss. A remarkable corundum rock from India is described by J. W. Judd in Mincralog. Mag., vol. 

11,1895, p. 50. For Burmese occurrences, see C. B. Brown and Judd, Proc. Roy. Soc., vol. 57,1895, p. 387. 

On the corundum granulite of Waldheim, Saxony, see E. Kalkowsky, Abhandl. Naturwiss. Gcsell. Isis, 

July-Dec., 1907, p. 47.
ROCK-FORMING MINERALS. 335

found large crystals of corundum in an albite-orthoclase rock near its 

contact with elaeolite syenite. They were associated with chrysoberyl 

and zinc spinel, zinc oxide and glucina having here played the part 

usually assigned to magnesia in the commoner magmas. In the Bidwell Bar quadrangle, California, A. C. Lawson i found a dike of an 

oligoclase-corundum rock cutting peridotite.

The solubility of alumina in peridotite magmas that is, in magmas free from lime and alkalies seems not to have been experimentally investigated. The corundum of North Carolina and Georgia, 

however, is associated with rocks of this class, and whether it was 

derived by fractional crystallization from the olivine rock, dunite, 

or from contact action with adjacent gneisses is an open question. 

The latter view, which is that of the earlier writers upon these localities, was advocated by T. M. Chatard, 2 but J. H. Pratt 3 argues in 

favor of a pyrogenic origin. According to Pratt, the corundum 

crystallized from the fused .dunite along the cooler surfaces of contact with the surrounding rocks. In these deposits spinel occurs but 

rarely. The corundum, emery, and iron spinel of the "Cortlandt 

series" in New York were 'regarded by G. H. Williams 4 as segregations in norite. 5

At Yogo Gulch, in the Little Belt Mountains of Montana, corundum is found in dikes of lamprophyre which contains too little 

alumina to satisfy the conditions laid down by Morozewicz, The 

occurrence has been carefully studied by W. H. Weed 6 and L. V. 

Pirsson, 7 who believe that the corundum was not in this case a constituent of the original magma, but that it has been produced by the 

action of the latter upon inclosed fragments of clay shale or limestone. This, of course, is a sort of contact action, but its mechanism 

is not clearly worked out. The thermal decomposition of minerals, 

especially of silicates, has so far been inadequately studied. Under 

what neutral conditions can alumina be liberated from its silicates ? 

This is a question which demands investigation, but it may be noted 

hero that Vernadsky, 8 by fusing muscovite, obtained sillimanite and

 Bull. Dopt. Geology Univ. California, vol. 3,1903, p. 219.

11 Bull. U. S. Gcol. Survey No. 42,1887, p. 45. Chatard gives abundant references to literature. Sec also 

F. P. lung's report upon Georgia corundum (Bull. Gcol. Survey Georgia No. 2, 1894), which contains a 

bibliography of American publications upon the subject. A similar publication by J. V. Lewis, on North 

Carolina corundum, forms Bull. No. 11 of the North Carolina Geol. Survey, 1890. Vol. 1 of the North Carolina Geol. Survey, 1905, by Pratt and Lewis, is a valuable monograph on corundum and chromitc.

3 Am. Jour. Sci., 4th scr., vol. 6,1898, p. 49: vol. 8,1899, p. 227. In Mineralog. Mag., vol. 12,1899, p. 139, 

J. W. Judd and W. E. Hidden have a paper upon North Carolina ruby: also in Am. Jour. Sci., 4th scr., 

vol. 8,1899, p. 370.

«Am. Jour. Sci., 3d ser., vol. 33,1887, p. 194.

s For an account of the emery mine at Chester, Massachusetts, see B. K. Emerson, Mon. U. S. Gcol. Survey, vol. 29,1898, p. 117. In Bull. U. S. Gcol. Survey No. 269,1906, J. H. Pratt gives a very complete 

account of the corundum and emery ol the United States, together with much information upon foreign 

localities. For the emery of Naxos, sec S. A. Papavasiliu, Geol. Ccntralbl., vol. 8, 1905, p. 99.

6 Twentieth Ann. Kept., U. S. Gcol. Survey, pt. 3,1900, p. 454.

' Idem, p. 552: Am. Jour. Sci., 4th scr., vol. 4, 1897, p. 421. Sec also G. F. Kunz, Am. Jour. Sei., 4th 

ser.,'vol. 4,1887, p. 417.

8 Cited by Morozewicz, Min. pet. Mitt., vol. 18,1898, p. 25.
336 DATA OF GEOCHEMISTRY. 7~

corundum. Natural corundum evidently may originate in more 

than one way, and no single process can account for all of its occurrences.

Notwithstanding the fact that corundum is on© of the most refrac- * 

tory of minerals toward aqueous solvents, being insoluble in even the 

strongest acids, it is not absolutely unalterable by them. S. J. 

Thugutt* found that corundum, upon prolonged heating with water 

to about 230° in a platinum digester, became appreciably hydrated. 

The product of the reaction after 336 hours contained 5.14 per cent 

of combined water. Even at 100° in an open vessel, some hydration * 

occurred. A1 similar prolonged treatment of corundum with a solution of the silicate K2Si205 converted it into a substance having the 

composition of orthoclase, while sodium silicate produced a compound resembling analcite. In nature reactions of this kind are 

conceivably possible, but they must be very slow; in the laboratory 

the acceleration due to temperature and pressure accounts for much *. 

of the change. However, alterations of corundum are common, and 

Thugutt's experiments give us some notion of the way in which they 

were probably effected. By water alone corundum may be transformed into diaspore, HA102 , which is one of its frequent associates. 

By further or coincident action of salts dissolved in percolating 

waters the alteration of corundum can be modified, and a considerable number of other minerals may be produced. 2 Among them 

gibbsite, spinel, sillimanite, kyanite, andalusite, pyrophyllite, muscovite, paragonite, chloritoid, margarite, zoisite, feldspars, tourmaline, 

and various vermiculites and chlorites have been recorded. 3 Some of 

these reported alteration products are doubtless secondary and not 

due to the direct transformation of corundum,, but on this subject 

there is much uncertainty. The envelopment of one mineral by 

another does not necessarily establish the derivation of the second 

from the first. The field observations and the study of natural speci- v, 

mens need to be reinforced by experiments in the laboratory before 

accurate conclusions concerning the alterations can be drawn.

THE SPINELS.

Spinel. Isometric. Composition, MgAl204 . Molecular weight, 

142.5. Specific gravity, 3.5. Molecular volume, 40.7. Usually 

colored violet, green, or red by impurities. Hardness, 8.

Hercynite. Isometric. Composition, FeAl204. Molecular weight, 

174.1. Specific gravity, 3.93. Molecular volume, 44.3. Color, black.

Hardness, 7.5 to 8. _____'__________________________ _____ ^

1 Mineralchemische Studien, Dorpat, 1891, p. 104.

2 For a discussion of the reactions which are supposed to produce the alterations of corundum, see C. R. ^ 

Van Hisc, Mon. U. S. Geol. Survey, vol. 47,1904, pp. 223-225.

8 F. A. Gcnth, Proc. Am. Philos. Soc., vol. 13,1873, p. 361; vol. 20,1882, p. 381; Am. Jour. Sci., 3d ser., 

vol. 39, 1890, p. 47. These papers are full of details regarding alteration products of corundum.
ROCK-FORMING MINERALS. 337

These minerals, together with gahnite, ZnAl2O4, magnetite, 

Fe"Fe'" 204 , magnesioferrite, MgFe204, franMinite, and chromite, 

form a natural isometric group, in which there are many intermediate 

mixtures. In the general formula R"R2 '"04, R" may be magnesium, ferrous iron, zinc, or manganese; and R"' is represented by 

aluminum, ferric iron, trivalent manganese, and chromium. In 

pleonaste we have an intermediate magnesium iron spinel, and in 

picotite chromium appears. Structurally the formula of spinel is 

commonly written 0=Al-0-Mg-0-Al = 0, but this should not 

be taken as a finality. It is not the only expression possible, nor has 

its validity been proved.

The following analyses of spinels show the wide variations in their 

composition:

Analyses of spinels.

A. Rose spinel, CeyJon. Analysis by H. Abich.

B. From Vesuvius. Analysis by H. Abich. Analyses A and B cited from Dana's System of mineralogy, 

6th ed., p. 222.

C. From Iherzolite, Auvergne. Analysis by F. Pisani, Compt. Bend., vol. 63,1866, p. 49.

D. From pyroxenite, Montana. Analysis by L. G. Eakins, Bull. U. S. Geol. Survey No. 220,1903, p. 20.

Ei Pleonaste from near Peekskill, New York. Analysis by C. A. Wolle, Am. Jour. Sci., 2d ser., vol. 48, 

1869, p. 350.

F. Hercynite from the Bohmcrwald. Analysis by B. Quadrat, Liebig's Annalen, vol. 55,1845, p. 357.

AI n

r.r i_>r2o ua .........................

Fe203 -- - ...................

FeO.. ........................

MnO..... ....................

MgO.. .......................

CaO. ........................

Si02 . ........................

A

69.01

1.10

.71

26.31

2.02

99.05

B

67.46

5.06

25.94

2.38

100. 84

£J

59.06

10.72

13.60

17.20

100. 58

D

62.09

2.62

9 10

17.56

Trace.

' 15.61

.16

KK

100. 69

" ' E

60.79

5.26

21.74

12.84

100. 63

F

61.17

35.67

2.92

99.76

Members of the spinel group have been made artificially by 

methods which generally recall those mentioned under corundum. 

For example, S. Meunier l fused a mixture of alumina, magnesia, 

cryolite, and aluminum chloride and obtained spinel crystals. In 

another investigation 2 he produced them by heating aluminum 

chloride and water with metallic magnesium in a sealed tube. These 

processes, with others which have been described, may, perhaps, 

represent in a broad way the pneumatolytic methods of nature. 

The production of spinel by the fusion of appropriate magmatio 

mixtures is, however, the process of greatest importance geologically, 

and some of the conditions attending its formation have been already 

described under corundum. E. S. Shepherd and G. A Rankin 3

i Compt. Rend., vol. 104,1887, p. 1111.

»Idem, vol. 90,1880, p. 701.

s Am. Jour. Sci., 4th ser., vol. 28,1909, p. 293.

113750° 19 Bull. 695 22
338 DATA OF GEOCHEMISTRY. .

have prepared spinel by direct fusion of its constituent oxides. 

J. H. Mourelo l obtained gahnite by heating a mixture of alumina, 

zinc oxide, and boric oxide to redness for 18 hours. The details of 

Morozewicz's experiments need not be repeated here.2 An interesting emphasis is given to them by the observations of G. Li nek,3 

who found, in a German gabbro, spinel associated with sillimanite 

and corundum.4

Spinels are also formed by the breaking down of other minerals or 

by the reactions of two or more species upon one another. According to Vernadsky,5 spinel is .among the compounds produced by 

the fusion of biotite, an observation which has been confirmed by 

C. Doelter.6 F. W. Clarke and E. A. Schneider 7 found it to be 

formed when clinochlore and xanthophyllite were strongly ignited, 

and Doelter 6 also obtained it by fusing the first-named species. 

Tourmaline, pyrope, and spessartite also yield spinel among the 

products of their fusion.8

According to Fouque* and Le>y 9 spinel and melanite are formed 

when nephelite and augite are fused together, and Doelter and 

Hussak 10- obtained spinel from a mixture of f ayalite and sarcolite. 

M. Vu6nik u found that a mixture of magnetite and anorthite gave 

recrystallized anorthite, hercynite, and glass, the magnetite having 

disappeared. Similar observations with augite-elseolite and corundum-elseolite mixtures were made by B. Vukits.12

Spinel, especially pleonaste, is a common accessory mineral in 

gneisses and in many eruptive rocks. Picotite is more characteristic of the peridotites and the derived serpentines. Spinel is a 

frequent companion of corundum and also of emery, as at Chester, 

Mass., and in thenoriteat Crugers, N. Y.13 A number of remarkable 

spinel rocks from Elba have been described by P. Aloisi.14 A troctolite from Madagascar, rich in spinelj is reported by A. Lacroix.15 

Many of these occurrences are easily interpreted in the light of 

Morozewicz's experiments. The other experiments, cited above,

i Chem. Abst., voL 9,1915, p. 2749. From Rev. gen. sci., vol. 26,1915, p. 394.

3 See also J. H. L. Vogt, Mineralbildung in Schmelzmassen, pp. 139-203.

3.Sitzungsb. E. Akad. Wiss. Berlin, 1893, p. 47.

* .Seealso W. Salomon, Zeitschr. Deutsch. geol. Gesell., vol. 42,1890, p. 525, for spinel In cordiorlte contact 

rocks in Italy. f

B Cited by J. Morozewicz, Min. pet. Mitt., vol. 18,1898, p. 59.

o Neues Jahrb., 1897, Band 1, p. 1.

7 Bull. U. S. Geol. Survey No. 113,1893, p. 30.

a Doelter, loc. cit., for tourmaline. C. Doelter .and E. Hussak, Neues Jahrb., 1884, Band 1, p. 157, for 

garnets.

> SynthSse des mine'raux et des roches, p. 64.-

» Neues Jahrb., 1884, Band 1, p. 157.

11 Ceatralbl. Min., GeoL u. PaL, 1904, p. 297. Criticized by J. Morozewicz in the.same journal, 1905, p. 148.

u Idem, 1904, pp. 710, 743.

« G. H. Williams, Am. Jour. Sci., 3d ser., vol. 33, 1887, p. 194. See also J. H. Bratt, Bull: U. S. Geol. 

Survey No. 269,1906, p. .34. .

14 Proc. verb. Soc. tosc. sci. nat., vol. 15, p. 60.

15 Bull. Soc. min., vol. 31, 1908, p. 318.
ROCK-FORMING MINERALS. 339

explain the appearance of spinel as a contact mineral. In many 

cases it appears in limestones as a product of contact metamorphism. 

Its alterations seem to have been little studied, but a change into 

steatite is mentioned in the literature.

Cliromite. Isometric. Normal composition, FeCr204 , but with 

variable replacements of Fe" by Mg and of Cr by Al and Fe'", as 

in the other members of the spinel group. Specific gravity, 4.32 

to 4.57. Color, black. Hardness, 5.5. The following analyses are

fairly typical: 1 ,

Analyses of chromite.

A. From vicinity of Mundorff, British Columbia. Chrompicotito. Analysis by E. A. A. Johnston, 

for G. C. HofTmann, Am. Jour. Sci., 4th ser., vol. 13,1902, p. 242.

B. From Corundum Hill, North Carolina. Analysis by C. Baskervillo, for J. H. Pratt, Am. Jour. Sci., 

4th ser., vol. 7,1899, p. 281.

C. From Webster, North Carolina. Analysis by H. W. Foote, for Pratt, loc. cit.

D. From Port au Port Bay, Newfoundland. Analysis by E. Waller, for G. W. Maynard, Trans. Am. 

Inst. Min. Eng., vol. 27,1897, p. 283.

E. From Tampadal, lower Silesia. Analysis by Laszczynski, for II. Traube, Zeitschr. Deutsch. geol. 

Gesell., vol. 46,1894, p. 50.

Or308 . ...............................

Al C\

FeA......... ........................

FeO

MnO................................

MgO. ........ .........................

Si02 ............... ...................

A

 55. 90

13.83

14.64

15.01

.60

99.98

B

57.80

7.82

25.68

go

5.22

2.80

100. 01

C

39.95

29.28

13.90

17. 31

100. 44

Do

49.23

7.50

17.21

Trn no

18.66

6.51

99. 11

E

41.23

24.58

2.28

16.99

.58

14.77

100. 43

aAlso contains traces of lime, copper, and vanadium.

The earlier syntheses of chromite seem to have little or no geological bearing. S. Meunier,2 however, who prepared chromite by 

oxidizing an alloy of iron and chromium, attributes its origin to a 

similar reaction occurring in nature. He supposes that such an 

alloy, like platinum and nickel iron, can be brought up from the 

interior of the earth to be oxidized by vapors when it nears the 

surface. Unfortunately, no such alloy has yet been found in the 

rocks, and in meteorites chromite itself is a common mineral.

Chromite is essentially a constituent of peridotites and of the 

serpentines derived from them. It is one of the earliest species 

formed during the solidification of the magma, and its larger deposits, 

when it occurs in ore bodies, are now generally ascribed to magmatic 

differentiation through the action of gravity. J. H. L. Vogt 3 thus

1 A very complete collection of chromite analyses, down to 1884, with literature references, is given in 

M. E. Wadsworth's Lithologicalstudies: Mem. Mus. Comp. Zool. Harvard Coll., vol. 11,1884. A mineral 

from Serbia, of composition Fe2O3.CraO8, has been named chromitite by M. Z. JovitscMtsch, Monatsh. 

Chemie, vol. 30, 1909, p. 39. Also, later, Bull. Soc. Min., vol. 35,1911, p. 511.

a Compt. Rend., vol. 110,1890, p. 424.

8 Zejtschr. prakt. Geologie, 1894, p. 384.
340 DATA OF GEOCHEMISTRY.

interprets the chromite deposits of Norway, and J. H. Pratt 1 has 

elaborated the same conception with respect to the chromic iron 

ores of North Carolina. The origin of corundum and of chromite in 

dunite Pratt explains in the same way. When a peridotite alters to 

serpentine the refractory chromite remains unchanged.

Magnetite, Isometric. Composition, Fe3O4 ,_ but with variable 

impurities and replacements. Molecular weight, 231.7. Specific 

gravity, 5.17. Molecular volume, 44.8. Color, black. Hardness, 

5.5 to 6.5. Magnesium, manganese, aluminum, and titanium are 

common impurities, rutile, ilmenite, hematite, and the spinels being 

frequent admixtures in magnetite. The titaniferous magnetites 

form a well-known subclass of ores. In a magnetite from the Tyrolese Alps, T. Petersen 2 found 1.76 per cent of nickel oxide, and the 

magnetites of eastern Ontario may contain half as much.3

Magnetite is often observed as a furnace product, and it forms the 

"iron scale" of the blacksmith. W. Miiller 4 found both magnetite 

and hematite in crystals among the oxidation products of the ironbearing residues from an aniline factory. The mineral has also been 

produced artificially by several investigators. J. J. Ebelmen 5 prepared it, well crystallized, by fusing together an iron silicate and 

lime. According to H. Sainte-Claire Deville, 8 ferrous oxide, heated 

in a stream of hydrochloric acid, forms magnetite, while a mixture 

of magnesia and ferric oxide, similarly treated, yields magnesioferrite, MgFe2 04 . T. Sidot 7 obtained magnetite by the calcination of 

ferric oxide alone.

In artificial magmas magnetite is easily formed, especially when 

the proportion of silica is low. Any excess of iron over that needed 

to combine with silica is likely to be deposited in the form of magnetite, although the conditions of its appearance are not so simple 

as in the separation of alumina as corundum.8 The order of its 

crystallization with reference to other minerals is by no means 

invariable.

Like the spinels, magnetite may be formed by the breaking down 

of other species, or by reactions between them. In other words, it 

may be a product of contact metamorphism. C. Doelter,8 for example, repeatedly obtained it by fusing various rocks in contact with

1 Trans. Am. Inst. Min. Eng., vol. 29,1899, p. 17. For a general review of chromite deposits, see StelznerBergeat, Die Erzlagerstatten, 1904, p. 33. The magmatic view is adopted in this work and also in Beck's 

treatise upon ore bodies.

2 Neues Jahrb., 1867, p. 836.

3 W. G. Miller, Rept. British Assoc., 1897, p. 600. 

« Zeitschr. Deutsch. geol. Gesell., vol. 45,1893, p. 63. 

" Compt. Rend., vol. 33,1851, p. 528. 

o Idem, vol. 53,1861, p. 199. 

' Idem, vol. 69,1869, p. 201.

8 See J. Morozewicz, Min. pet. Mitt., vol. 18,1898, p. 84, and J. H. L. Vogt, Mineralbildung in Schmelzmassen, pp. 203-212.

9 Neues Jahrb., 1886, Band 1, p. 128.
BOOK-FORMING MINERALS. 341

limestone a procedure which recalls Ebelmen's experiment. Acmite upon .fusion yields magnetite and a glass,1 and glaucophane 

gives similarly a mixture in which magnetite appears. By melting 

together biotite and microcline, Fouque and LeVy2 obtained magnetite, leucite, and olivine. J. Lenarci6 3 found magnetite in the mass 

produced by fusing leucite with augite; but on the other hand, when 

magnetite and labradorite were taken, the former mineral was dissolved and augite appeared. Similar observations were made by 

M. Vu6nik 4 and B. Vukits,5 who found magnetite among the fusion 

products of anorthite and hedenbergite, albite and hedenbergite, 

olivine and augite, elseolite and augite, and elaeolite and diopside. 

Each of these couples, when fused, yielded magnetite, with other 

products which varied according to the nature of the mixture.

Magnetite occurs as an accessory mineral in rocks of all classes, 

and it sometimes rises to the rank of a principal constituent, or even 

forms rock masses by itself. It is obviously most abundant in rocks 

rich in ferromagnesian minerals, such as norites, diabases, gabbros, 

or peridotites; but it is also associated with nepheline rocks and 

anorthites. In many cases it forms large ore bodies that are regarded 

as products of magmatic differentiation; and these deposits, as a 

rule, are highly titaniferous.6 Some ores shade from magnetite into 

ilmenite, with over 40 per cent of titanic oxide. They frequently 

contain spinel, and sometimes, also, corundum.

In the great iron deposits of the Lake Superior region, and the 

adjacent parts of Michigan, Wisconsin, and Minnesota, magnetite is 

found in slates and cherts, often associated with grunerite and actinolite.7 Here the mineral is not of direct igneous origin. In the Mesabi 

district, according to C. K. Leith,8 it is derived from the leaching of 

a hydrous iron silicate, of uncertain composition, to which he has 

given the name "greenalite." Other silicates may yield magnetite 

through metamorphic changes, and it can also form, says C. R. Van 

Hise,9 from marcasite and pyrite, and from the oxidation of siderite

1 Doelter, Neues Jahrb., 1897, Band 1, p. 1. Sec also M. Vucnik, cited below.

8 Synthese des minc'raux et des roches, p. 77.

s Centralbl. Min., Gcol. u. Pal., 1903, pp. 705, 743.

«Idem, 1904, pp. 300, 342, 344, 345, 366, 369.

"> Idem, 1904, pp. 705, 715, 743, 748.

« See J. H. L. Vogt, Zeitschr. prakt. Geologic, 1893, p. 6; 1894, p. 382; 1900, pp. 234, 370; 1901, pp. 9, ISO, 

289, 327. J. F. Kemp, Nineteenth Ann. Kept. U. S. Geol. Survey, pt. 3, 1899, p. 377; School of Mines 

Quart., vol. 20,1899, p. 323; vol. 21,1900, p. 56; Zeitschr. prakt. Geologic, 1905, p. 71. W. Lindgren, Science, 

vol. 16,1902, p. 984. G. H. Williams, Am. Jour. Sci.,3d ser., vol. 33,1887, p. 194. R. Beck, Lehre von den 

Erzlagerstatten, 2d ed., pp. 20-30. Kemp's paper in the School of Mines Quarterly is a general review of 

the titaniferous magnetites, with many analyses and copious references to other literature. In Zeitschr. 

prakt. Geologic, 1907, p. 86, Vogt describes magmatic iron ores in granite. On magmatic iron ores in Utah 

see E. P. Jennings, Trans. Am. Inst. Min. Eng., vol. 35, 1905, p. 338. On the magmatic magnetites of 

Lapland, see O. Stutzer, Noues Jahrb., Beil. Band 24,1907, p. 548. A magnetite basalt from Colorado is 

described by H. S. Washington and E. S. Larsen in Jour. Washington Acad. Sci., vol. 3,1913, p. 449.

7 See C. R. Van Hise, W. S. Bayley, H. L. Smyth, and J. M. Clements, in Mon. U. S. Geol. Survey, vol. 

28,1897; vol. 36,1889; and vol. 45,1903.

8 Mon. U. S. Geol. Survey, vol. 43,1903, pp. 101-115.

9 A treatise on metamorphism: Mon. U. S. Geol. Survey, vol. 47,190-1, p. 229.
342 DATA OF GEOCHEMISTRY.

in place. By further oxidation magnetite can alter to hematite and 

limonite, and through the agency of carbonated waters it may be 

transformed into siderite again.

HEMATITE.

Rhombohedral. Composition, Fe203 . Molecular weight, 159.8. 

Specific gravity, 5.2. Molecular volume, 30.7. Color, red to steelgray and black. Hardness, 5.5 to 6.5. Hematite has been prepared 

artificially by several methods. In the classical experiment of 

Gay-Lussac, 1 the vapor of ferric chloride was decomposed by steam * 

at a high temperature, and crystals of hematite were formed. A. 

Daubr6e 2 obtained it by passing ferric chloride vapor over lime; and 

H. Sainte-Claire Deville 3 prepared the specular variety by the slow 

action of gaseous hydrochloric acid upon ferric oxide at a red heat. 

Hematite is also produced, according to H. Arctowski,4 by the action 

of vaporized ammonium chloride upon either red-hot iron or ferric * 

oxide. It has also been noted as a sublimation product in the saltcake furnaces of certain chemical works.5 Fine crystals of hematite, ^ 

grouped in rosettes, have been formed in the iron heating pipes of a 

Deacon chlorine apparatus in Philadelphia.- Some of the' crystals 

were as much as 3 centimeters in diameter. Their formation was due 

to the action of heated air and hydrochloric acid upon the iron.6 

Ferric chloride was probably first formed and then transformed into 

hematite by aqueous vapor. All these reactions are analogous to, if 

not identical with, those that produce the so-called "sublimed" 

hematite which is seen upon volcanic lavas. A. Arzruni,7 on comparing the volcanic mineral with the artificial product, found them 

to be crystallographically identical. W. Bruhns's experiment,8 in 

which hematite was formed by heating amorphous ferric oxide with 

water and a trace of ammoniuni fluoride to 300° in a platinum tube, *^ 

seems to be less closely related to geological phenomena.

Fouque" and Levy ° repeatedly obtained hematite from artificial 

magmas, and similar observations have been made by others. In 

ordinary furnace slags, however, according to J. H. L. Vogt,10 hematite rarely if ever occurs. Ferric oxide can crystallize out as hematite 

only when ferrous compounds are either absent or present in quite "*" 

subordinate amounts, for ferrous oxide unites with it to form mag1 See E. Brauns, Chemische Mineralogie, 1896, p. 231.

2 Compt. Rend., vol. 39,1854, p. 135.

»Idem, vol. 52,1861, p. 1264.

* Zeitschr. anorg. Chemie, vol. G, 1894, p. 377; Bull. Acad. roy. sci. Belgique, 3dser., vol. 27,1894, p. 933.

6 See H. Vater, Zeitschr. Kryst. Min., vol. 10,1885, p. 391; and B. Doss, idem, vol. 20,1892, p. 560.

o C. E. Munroe, Am. Jour. Sci., 4th ser., vol. 24,1907, p. 485. ,-±

1 Zeitschr. Kryst. Min., vol. 18,1891, p. 40.

B Neues Jahrb., 1889, Band 2, p. C2.

9 Synthese des mine'raux et des rochcs, p. 230.

10 Mineralbildung in Schmelzmassen, pp. 215-217. Cf. also J. Morozewicz, Min. pet. Mitt., vol. IS, 1398, 

p. 84.
ROCK-FORMING MINERALS. 343

netite. The latter species, therefore, is characteristic of rocks rich in 

ferromagnesian minerals, while hematite appears chiefly in the more 

siliceous and feldspathic granites, syenites, trachytes, rhyolites,

* andesites, and phonolites. It is also found in the crystalline schists; 

but magnetite is by far the more common as a pyrogenic mineral. In 

igneous rocks generally ferrous oxide exceeds the ferric in amount, 

the average percentages, as shown by 961 analyses,1 being 3.46 FeO 

and 2.63 Fe3 03 . This preponderance of the lower oxide seems to 

determine the frequent formation of magnetite. The ferric pyrite and

> the ferrous pyrrhotite appear to follow the same rule of association, 

the one being commonest in highly silicic rocks, the other accom-

* panying the ferromagnesian minerals.

Hematite alters into limonite, magnetite, pyrite, marcasite, and 

siderite,2 and in metamorphic rocks it may be derived from the same 

species. Limonite, siderite, and magnetite are especially liable to 

yield it. The derivation of hematite from silicates is probably always 

indirect, one or another of the above-named species having been

^ formed first. Titanium is a common impurity in hematite, and L. J. 

Igelstrom,3 in a Swedish ore, found molybdenum in very appreciable 

amounts.

TITANIUM MINERALS.

Ilmenite. Rhombohedral. Composition, FeTi03 . Molecular 

weight, 152. Specific gravity, 4.5 to 5. Molecular volume, 30.4. 

Color, black; luster, submetaHic. Hardness, 5 to 6.

Ilmenite, menaccanite, or titanic iron has been little investigated 

upon the synthetic side. W. Bruhns 4 prepared it, mixed with some 

magnetite, by heating finely divided metallic iron, ferric oxide, and 

amorphous titanic oxide with h}7 drochloric acid in a platinum tube 

to 270-300°. In nature, however, it is found most widely diffused. 

>^ It occurs with or replacing hematite in granite and syenites and as an 

essential constituent in diorite, diabase, gabbro, basalt, etc., often 

with magnetite.5 In these rocks it is one of the earliest minerals to 

separate. It is also found in metamorphic rocks, such as gneiss, 

mica schist, and amphibolite. A. von Lasaulx ° describes ilmenite 

as an alteration derivative of rutile.

*^ The constitution of ilmenite has been much discussed. Some authorities have regarded it as an isomorphous mixture of Fe203 and 

Ti2 03 ; but C. Friedel and J. Gue*rin,7 who prepared the latter com-

» Bull. U. S. Geol. Survey No. 228,1904, p. 17.

2 C. R. Van Else, A treatise on metamorphism: Mon. U. S. Gcol. Survey, vol. 47,1904, p. 22G.

a Zeitschr. Kryst. Min., vol. 25,1896, p. 94. 

^< < Ncues Jahrb., 1889, Band 2, p. G5.

8 Sec the papers of Vogt, Kemp, and others cited under magnetite. The titanifcrous magnetites are 

mixtures of that species with ilmenite. See also A. Cathrcin, Zeitschr. Kryst. Min., vol. 8,1884, p. 321. 

TJrbainite is a rock rich in ilmenite found at St. Urbain, Canada. Described by C. II. Warren, Am. Jour. 

Sci., 4th ser., vol. 33,1912, p. 263.

6 Zeitschr. Kryst. Min., vol. 8, }SS4, p. 5.1.

* Annalcs chim. phys., 5th ser., vol. 8,1876, p. 38.
344 DATA OF GEOCHEMISTRY.

pound artificially, do not favor this view. Ti2 03 as such has not been 

found as an independent mineral. T. Konig and 0. von der Pfordten 1 

made various attempts to detect Ti203 in ilmenite and only met with 

failure. Since the mineral pyrophanite, MnTi03, isomorphouS with 

ilmenite, is known, and since, as S. L. Penfield and H. W. Foote 2 

have shown, ilmenite sometimes contains large admixtures of the 

molecule MgTi03 , the formula FeTi03 may now be regarded as established for titanic iron. In an ilmenite from Warwick, New York, 

Penfield and Foote found 16 per cent of magnesia. In fact, the compound MgTi03 is independently represented by the mineral geikielite 3 from Ceylon. An excess of iron in ilmenite may be due to 

admixed hematite and an excess of titanium to rutile.

Ilmenite is often surrounded by a margin of white or even reddish 

alteration products, which is commonly known by the name of leucoxene. According to A. Cathrein,4 this substance is essentially 

titanite, sometimes accompanied by rutile.

Pseudobrookite. Orthorhombic. Composition, ferric orthotitanate, Fe4 (Ti04 ) 3 . Molecular weight, 559.9. Specific gravity, 4.39. 

Molecular volume, 127.5. Color, dark brown to black. Hardness, 6.

Pseudobrookite is a rare accessory mineral in certain eruptive 

rocks, such as andesite, trachyte, basalt, and nephelinite. A similar 

mineral, formed by "sublimation" in a salt-cake furnace, was described by B. Doss,5 who gave it the formula Fe2Ti05 and made it 

isomorphous with andalusite, Al2Si05. The natural mineral, however, 

has the orthotitanate formula, as given above. 6

Perofskite. Isometric or pseudoisometric. Composition, calcium 

titanate, CaTi03 . Molecular weight, 136.2. Specific gravity, 4. 

Molecular volume, 34. Color, yellow, ranging through orange and 

brown to grayish black. Hardness, 5.5.

Perofskite has been prepared synthetically by several chemists. 

J. J. Ebelmen 7 obtained it by fusing titanic oxide with lime and 

potassium carbonate; and later 8 by the action of lime on an alkaline 

melt containing titanic oxide and silica. P. Hautefeuille 9 heated a 

mixture of calcium chloride, titanic oxide, and silica to redness in a 

stream of moist carbon dioxide, or of hydrochloric acid, and obtained 

perofskite crystals. L. Bourgeois 10 observed its deposition from 

various fused mixtures resembling natural magmas in composition.

1 Ber. Deutsch. chem. Gesell., vol. 22,1889, p. 1485. See also W. Manchot, Zeitschr. anorg. Chemie, vol. 

74,1912, p. 79.

2 Am. Jour. Sci., 4th ser., vol. 4,1897, p. 108.

a A description of geikielite by T. Crook and B. M. Jones is printed in Mineralog. Mag., vol. 14,1906, p. 160. 

' Zeitschr. Kryst. Min., vol. 6,1882, p. 244.

' Idem, vol. 20,1892, p. 566. Doss gives a good bibliography of pseudobrookite. 

6 Established by A. Frenzel, Min. pet. Mitt., vol. 14, p. 121; confirming the earlier analyses of A. Koch, 

G. Lattermann, and A. Cedarstrom. See E. S. Dana, System of mineralogy, 6th ed., p. 232. 

' Compt. Eend., vol. 32,1851, p. 710. 

8 Idem, vol. 33,1851, p. 528. 

s Annales chim. phys., 4th ser., vol. 4,1865, p. 163. 

" Idem, 5th ser., vol. 29,1883, p. 479.
J- SOCK-FORMING MINERALS. 345

Finally, P. J. Holmquist* prepared perofskite by fusing together 

sodium carbonate, calcium carbonate, and titanic oxide, under special 

manipulative conditions.

* Perofskite occurs both in eruptive and metamorphic rocks. It is 

found in melilite, leucite, and nepheline rocks, and in some peridotites ; 2 and is among the earliest secretions. It is particularly characteristic of melilite basalt, being, according to A. Stelzner,3 the most 

faithful companion of melilite. At Catalao, Brazil, E. Hussak 4 found 

a peculiar rock consisting of magnetite and perofskite; a titaniferous

^ magnetite of a new kind. A similar rock has been found in the Uncompahgre quadrangle by E. S. Larsen and analyzed in tho laboratory of the United States Geological Survey. Perofskite is also found 

in chlorite schist, limestone, quartz gneiss,5 etc. Hussak observed its 

alteration into titanic oxide, and K. Schneider c has described perofskite as derived from titanite.

-* Titanite. Monoclinic. Composition, CaTiSi06. Molecular weight, 

196.5. Specific gravity, 3.54. Molecular volume, 55.5. Color, yellow, green, red, gray, brown, or black. Hardness, 5 to 5.5.

Titanite, or sphene, has been produced artificially by several experimenters, but it does not seem to be easily formed. P. Hautefeuille 7 

prepared it by fusing a mixture of silica and titanic oxide with calcium chloride. L. Bourgeois 8 obtained it, but obscurely developed,

^ by fusing together its constituent oxides, silica, titanic oxide, and 

lime. L. Michel 9 fused ilmenite with calcium sulphide, silica, and 

carbon, which yielded a mixture of titanite, garnet, and a subsulphide 

of iron. S. Smolensky 10 prepared titanite by Bourgeois's method and 

determined its melting point as 1,221°. 

As a pyrogenic mineral titanite is found among the oldest secrey^. tions in the more siliceous rocks, such as granites, diorites, syenites, 

and trachyte. It is abundant in phonolites and elseolite syenites, 

and is also common as a secondary mineral, derived by alteration 

from rutile or ilmenite. It is often associated with chlorite. At 

Green River, North Carolina, large crystals of sphene are found completely or partially altered into a yellow, friable, earthy substance

^ which has been given the name of xanthitane. According to L. G. 

Eakins, 11 this product is a hydrous titanate of aluminum. An alteration of titanite into rutile has been observed by P. Mann 12 in tho

1 Bull. Geol. last. Upsala, vol. 3,1896-97, p. 181.

2 See G. H. Williams, Am. Jour. Sci., 3d ser., vol. 34,1887, p. 137; J. S. Diller, idem, vol. 37,1889, p. 219.

s Neues Jahrb., Beil. Band 2,1883, p. 390.

1 Ncues Jahrb., 1894, Band 2, p. 297. 

, » See 0. Miigge, Neues Jahrb., Beil. Band 4,1886, p. 581.

e Neues Jahrb., 1889, Band 1, p. 99.

7 Annales chim. phys., 4ta ser.| vol. 4,1865, p. 129.

«Idem, 5th ser., vol. 29,1883, p. 474.

« Compt. Rend., vol. 115,1892, p. 830. 

10 Zeitschr. anorg. Chemie, vol. 73,1912, p. 302. 

'i Bull. U. S. Geol. Survey No. GO, 1890, p. 135. 

» Neues Jahrb., 1882, Band 2, p. 200.
346 DATA OF GEOCHEMISTRY. ,

foyaite of the Serra de Monchique; and B. Doss l has reported pseudoniorphs of anatase after sphene.

Rutile. Tetragonal. Composition, TiO2 . Molecular weight, 80.1. 

Specific gravity, 4.2. Molecular volume, 19.1. Color, commonly red- .*. 

dish to brown or black. Hardness, 6 to 6.5.

Brookite. Orthorhombic. Composition and molecular weight as 

for rutile. Specific gravity, 4. Molecular volume, 20. Color, yellowish, reddish, brown, or iron-black. Hardness, 5.5 to 6.

Octahedrite or anatase. Tetragonal. Composition and molecular 

weight the same as for rutile and brookite. Specific gravity, 3.82 to ^ 

3.95. Molecular volume, 20.5. Color, brown, indigo-blue, and black. 

Hardness, 5.5 to 6.

All three modifications of titanic oxide have been studied synthetically. Crystals of brookite were obtained by A. Daubree, 2 by the 

action of aqueous vapor upon titanic chloride at a red heat. By 

heating amorphous titanic oxide to redness in a current of hydro- ,*, 

chloric acid gas, H. Sainte-Claire Deville and H. Caron 3 transformed 

it into a cyrstalline modification, and similar results were obtained * 

by P. Hautefeuille and A. Perrey.4 By the prolonged heating of 

titanic oxide with boric acid J. J. Ebelmen 5 obtained rutile, and P. 

Hautefeuille 6 attained the same end when sodium tungstate or vanadate was used as flux. H. Traube 7 also crystallized rutile from fused 

sodium tungstate, and was able to add to it appreciable quantities of 

iron, manganese, and chromium, impurities which are found in the * 

natural mineral. Several investigators have prepared'rutile by the 

same general process, using microcosmic salt as the solvent. B. Doss,8 

by this method, prepared both rutile and anatase. Deville and 

Caron 9 also prepared rutile by heating titanic oxide with silica and 

oxide of tin to redness. By heating ilmenite and pyrite together at 

about 1)200°, L. Michel 10 obtained a mixture of rutile and pyrrhotite. "^

The three forms of titanic oxide were reproduced by P. Hautefeuille " by various modifications of the same general pneumatolytic 

process. Potassium titanate and calcium chloride were heated in a 

current of hydrochloric acid mixed with air, and crystals were formed. 

Titanic oxide with potassium or calcium fluoride, or potassium silicofluoride, similarly treated, gave the same product, which, when the '*" 

operation was conducted at a strong red heat, was rutile. Brookite 

was formed by heating potassium titanofluoride in aqueous vapor,

1 Neues Jahrb., 1895, Band 1, p. 128.

2 Compt. Rend., vol. 29,1849, p. 227.

s Idem, vol. 53,1861, p. 161.

« Idem, vol. 110,1890, p. 1038.

"> Idem, vol. 32,1851, p. 330.

o Cited by Bourgeois, Reproduction artiflcielle des mta&aux, 1884, p. 85.

7 Neues Jahrb., Beil. Band 10,1895-96, p. 470. '« 

a Idem, 1894, Band 2, p. 147.

8 Compt. Rend., vol. 53,1861, p. 161.

10 Idem, vol. 115,1892, p. 1020.

11 Annales chim. phys., 4th ser., vol. 4,1865, p. 129.
HOCK-FORMING MINERALS. 347

and by the action of hydrofluoric acid upon titanic chloride, at a 

temperature not higher than the boiling point of zinc. A mixture 

of titanic oxide, calcium fluoride, and potassium chloride, heated in 

a stream of hydrochloric acid, silicon fluoride, and moist hydrogen, 

also gave brookite, and so did titanic oxide, silica, and potassium 

silicofluoride in a current of hydrochloric acid alone. When titanic 

fluoride was decomposed by aqueous vapor at a lower temperature, 

at or near the boiling point of cadmium, octahedrite was produced. 

How far these experiments may parallel the pneumatolytio processes 

of nature is doubtful; but they show that rutile, the most stable 

modification of titanic oxide, is formed at the highest temperatures, 

brookite at temperatures considerably lower, and anatase at a point 

still lower in the scale. These observations are in harmony with the 

known occurrences of the three species as rock-forming minerals.

Rutile occurs as a pyrogenic mineral in eruptive rocks, but it is 

more common in gneiss, mica schist, and the phyllites. In a hornblende gneiss from Freiberg, A. Bergeat* observed rutile, ilmenite, 

and titanite, which had formed as a single generation and crystallized 

before the biotite. A remarkable dike rock in Nelson County, Virginia, described by T. L. Watson and S. Taber,2 consists essentially of 

rutile and apatite. Rutile is also found as a secondary mineral, 

derived from ilmenite and titanite. C. Dbelter 3 found rutile to bo 

slightly soluble in water, and more so in a solution of sodium fluoride. 

From such a solution after heating to 145° during thirty-four days 

the mineral was partially recrystallized. Possibly some secondary 

rutile may originate from solution of the original substance, or of 

titanic oxide leached from another species.

Brookite is not found in fresh eruptive rocks, but generally in 

decomposed granite, gneiss, quartz porphyry, and the sedimentaries. 

Octahedrite is never primary, but is formed by the alteration of other 

titanium minerals. It has been observed under a great variety of 

conditions, as in granite, diabase, quartz porphyry, dioritc, the crystalline schists, shales, sandstones, and limestones.4

Brookite alters into rutile, and rutile into ilmenite, anatase, and 

sphene. The titanium minerals are thus closely connected with one 

another, and transformations are possible in almost every direction. 

From a magma deficient in lime and iron, titanic oxide may separate 

as rutile; when lime is abundant, titanite or perofskite may form; 

in presence of much iron ilmenite or pseudobrookite will be deposited. 

Brookite and octahedrite appear only as secondary minerals.

J Neuos Jahrb., 1895, Band 1, p. 232.

s Bull. U. S. Geol. Survey No. 430,1910, p. 200.

a Min. pet. Mitt., vol. 11,1890, p. 325.

4 For a very full summary of the occurrence of zircon and the titanium minerals, especially brookite and 

anatase, see II. Thiirach, Verhandl. Phys. med. Gosoll. Wiirzburg, vol. 18, No. 10,1884. On the rutUo of 

Nelson County, Virginia, see G. P. Merrill, Eng. and Min. Jour., March 8,1902, and T. L. Watson, Econ. 

Geology, vol. 2,1907, p. 493.
348 DATA OF GEOCHEM1STEY.

CASSITERITE AND ZIRCON.

. Cassiterite. Tetragonal. Composition, stannic oxide, Sn02 . Molecular weight, 151. Specific gravity, 6;9. Molecular volume, 21.9. 

Color, commonly brown to black, rarely colorless, red, or yellow. 

Hardness, 6 to 7.,

A. DaubreV prepared cassiterite by the action of aqueous vapor 

upon tin tetrachloride in a red-hot porcelain tube. H. Sainte-Claire 

Deville 2 obtained it by passing gaseous hydrochloric acid over the 

amorphous oxide of tin at a high temperature,, and also by acting 

upon stannous chloride with aqueous vapor. According to A. Ditte 3 

stannic oxide may be crystallized by fusion with calcium chloride, 

and its crystallization is mentioned by Deville and H. Caron 4 as 

having been effected by heating a fluoride of tin with boric oxide. 

The formation of cassiterite as a furnace product has several times 

been observed, most recently by A. Arzruni 5 and J. H. L. Vogt.8 

In this case it was produced during the manufacture of pulverulent 

stannic oxide, by the slow oxidation of metallic tin. With this exception, the syntheses of cassiterite point to its origin as a pneumatolytic mineral, and its commoner associations tell a similar story. It 

is almost invariably accompanied by minerals containing boric oxide 

or fluorine, such as topaz, tourmaline, lepidolite, and apatite.7

Cassiterite is rarely found as an original rock-forming mineral. 

M. von Miklucho-Maclay 8 has reported it accompanied by rutile, 

topaz, apatite, and tourmaline, as an inclusion in the mica of a granite. According to B. Beck, 9 it is also an original constituent of 

granite on the islands of Banca and Billiton. It also occurs, but 

sparingly, in the lithia-bearing pegmatites of Maine and California, 

and, according to L. C. Graton, 10 as an original constituent of pegmatite in the Carolinas. The relations of cassiterite as a vein mineral 

will be considered in another connection later.

Zircon. Tetragonal. Composition, zirconium orthosilicate, ZrSi04 . 

Molecular weight, 183. Specific gravity, 4.6 to 4.8. Molecular volume, 38.7. Color, commonly brown, but also colorless, yellow, red, 

bluish, green, etc. Hardness, 7.5.

Zircon has been repeatedly produced synthetically. H. SainteClaire Deville and H. Caron 11 obtained it by heating zirconia in a

1 Compt. Rend., vol. 29,1849, p. 227.

2 Idem, vol. 53,1861, p. 161.

«Compt. Rend., vol. 96,1883, p. 701.

«Idem, vol. 46,1858, p. 766.

6 Zeitschr. Kryst. Min., vol. 25,1896, p. 467.

e Idem, vol. 31,1899, p. 279.

' For a list of the minerals occurring with cassiterite, see W. Kohlmann, Zeitschr. Kryst. Min., vol. 24, 

1895, p. 350.

8 Neues Jahrb., 1885, Band 2, p. 88.

o Zeitschr. Kryst. Min., vol. 33,1900, p. 205. 

i« Bull. U. S. Geol. Survey No. 293,1906. 

» Compt. Rend., vol. 46,1858, p. 764.
EOCK-FOBMING MINERALS. 349

current of silicon fluoride. Deville 1 also prepared it by heating zirconia with quartz in the same gas. In the latter process, which is 

identical in character with the former, zirconium fluoride is formed, 

which reacts upon the quartz, regenerating the silicon fluoride. A 

small quantity of the latter substance may therefore generate an 

indefinite amount of zircon. P. Hautefeuille and A. Perrey2 obtained 

zircon when a mixture of silica, zirconia, and lithium molybdate was 

heated to 800°. Finally, K. Chrustschoff 3 effected the synthesis of 

zircon by heating gelatinous silica and gelatinous zirconia together^ 

under pressure, to a temperature near redness. Deville's work indicates a possible pneumatolytic origin for zircon in some instances; 

the other processes seem to be unrelated to the ordinary occurrences 

of the mineral.

Zircon is one of the commonest accessory constituents in all classes 

of igneous rocks. It is especially common in the more silicic species, 

such as granite, syenite, diorite, etc., and in all the younger eruptives. 

It is very characteristic of the nepheline syenites.4 It is one of the 

earliest minerals to crystallize from the cooling magmas, and the 

first one among the silicates. With or in place of zircon some more 

complex silicates, such as the zircon pyroxenes, may form. These 

substances, however, are exceedingly rare and quite imperfectly

known.

PHOSPHATES.

Apatite. Hexagonal. Composition variable, two compounds being 

included in the species.5 They are Ca5 (P04) 3F and Ca5 (P04 ) 3Cl. 

Molecular weight, 504.5 for fluorapatite and 521 for chlorapatite. 

Specific gravity, 3.17 to 3.23. Molecular volume, 159.1 to 161.6. 

Color, white, green, blue, red, yellow, gray, or brown. Hardness, 5.

The first synthesis of apatite was effected by A. Daubree, 6 who 

obtained it in crystals by passing the vapor of phosphorus trichloride 

over red-hot lime. N. S. Manross 7 fused sodium phosphate either 

with calcium chloride, calcium fluoride, or both together, and so 

obtained chlorapatite, fluorapatite, or a mixture of the two, resembling 

natural apatite, at will. This process, slightly modified, was also 

adopted by H. Briegleb 8 successfully. G. Forchhammer 9 prepared

' Compt. Rend., vol. 52,1861, p. 780.

2 Idem, vol. 107,1888, p. 1000.

8 Neues Jahrb., 1892, Band 2, p. 232.

4 For an elaborate discussion of the natural occurrences of zircon, see H. Thiirach, Verhandl. Phys. 

med. Gesell. Wiirzburg, vol. 18, No. 10, 1884. For zircon in the augite syenites of Norway, see W. C. 

Brogger, Zeitschr. Kryst. Min., vol. 16,1890, p. 101. A zirconiferous sandstone found near Ashland, Virginia, has been described by T. L. Watson and F. L. Hess, Bull. Philos. Soc. University of Virginia, vol. 1, 

1912, p. 267.

6 For complete analyses of apatite, with a discussion of its variations, see J. A. Voelcker, Ber. Deutsch. 

chem. Gesell., vol. 16,1883, p. 2460. For manganese, magnesium, cerium, etc.,in apatite, see E. S. Dana, 

System of mineralogy, 6th ed., pp. 764, 765.

o Compt. Rend., vol. 32,1851, p. 625.

7 Liebig's Annalen, vol. 82,1852, p. 353.

8 Idem, vol. 97,1856, p. 95.

0 Idem, vol. 90,1854, pp. 77,322.
Xr

350 DATA OF GEOCHEMISTRY.

ychlorapatite by fusing calcium phosphate with sodium chloride. 

When bone ash or marl was used instead of the artificial calcium phosphate, a mixed apatite was formed. Similar results were reported by 

Deville and Caron, 1 who fused bone ash with ammonium chloride ^ 

and either calcium chloride or fluoride, and also by A. Ditte,2 who 

repeated Forchhammer's experiment. By heating calcium phosphate 

with calcium chloride and water, under pressure, at 250°, H. Debray 3 

prepared chlorapatite. E. Weinschenk 4 also produced it by heating 

calcium chloride, ammonium phosphate, and ammonium chloride at 

temperatures of 150° to 180° in a sealed tube. F. K. Cameron and ^ 

W. J. McCaughey 5 prepared fluorapatite by dissolving calcium 

fluoride in fused disodium phosphate and lixiviating the cooled melt. 

Chlorapatite was formed when dicalcium phosphate was added in 

excess to molten calcium chloride. When precipitated calcium phosphate was used, chlorspodiosite was obtained, Ca3 (P04 )2 .CaCl2 . 

R. Nacken,0 by fusing calcium fluoride or chloride with calcium phos- ^ 

phate, obtained both species of apatite, and also mixed crystals. 

Apatite has been reported as present in lead-furnace slags by W. M. h 

Hutchins 7 and J. H. L. Vogt.8 The composition of these slag products, however, seems not to have been verified by analysis.

Apatite is found in all classes of rocks igneous, metamorphic, and 

sedimentary. In the eruptives it appears as one of the oldest secretions from the magma. It is more common in femic rocks than in 

the more siliceous varieties. Titaniferous magnetites, like those of < 

Norway and the Adirondacks, often contain apatite in large amounts. 

Apatite also appears as an important vein mineral; and in these occurrences Vogt 9 regards it as having been formed by pneumatolytic 

agencies. According to R. Miiller,10 apatite is strongly attacked by 

waters containing carbonic acid. Both lime and phosphoric acid 

pass into solution. A carbonated mineral allied to apatite has ->-< 

been described by W. Tschirwinsky/1 under the name podohte. Its 

composition is represented by the formula 3Ca3P208.CaC03 , which is 

that of apatite with calcium fluoride replaced by calcium carbonate.

Monazite. Monoclinic. Composition, normally, cerium phosphate, 

CeP04, but other rare-earth metals are always present, replacing

 - jL

1 Compt. 'Rend., vol. 47,1858, p. 985.

a Idem, vol. 94,1882, p. 1592.

3 Compt. Rend., vol. 52,1861, p. 44.

« Zeitschr. Kryst. Min., vol. 17,1890, p. 489.

B Jour. Phys. Chem., vol. 15,1911, p. 464.

«Centralbl. Min., Geol. u. Pal., 1912, p. 545. Similar results were obtained by T. R.Mourelo(Chcm. 

Abst., vol. 9,1915, p. 2749; from Rev. g&i. sci., vol. 26,1915, p. 394).

' Nature, vol. 30,1887, p. 460.

8 Mineralbildung in Schmelzmassen, p. 263. u

* See his paper in Trans. Am. Inst. Min. Eng., vol. 31,1901, p. 134, and also papers in Zeitschr. prakl. 

Geologic, 1894, p. 458; 1895, pp. 367,444, 465.

»o Jahrb. K.-k. geol. Reichsanstalt, vol. 27, Min. pet. Mitt., 1877, p. 25.

" Ccntralbl. Min., Geol. u. Pal., 1907, p. 279. According to W. T. Sehaller (Am. Jour. Sci., 4th ser.. vol. 30, 

1910, p. 309), podolite is identical with dahllite, which was described much earlier.
KOCK-rOEMHSTG MINERALS. ' 351

cerium. Molecular weight, 235.25. Specific gravity, 5. Molecular 

volume, 47. Color, yellow, reddish, and brown. Hardness, 5 to 5.5.

Xenotime. Tetragonal. Composition, yttrium phosphate, YtP04. 

Molecular weight, 189. Specific gravity, 4.5. Molecular volume, 42. 

Color, grayish white, yellowish, reddish, and commonly brown. 

Hardness, 4 to 5.

Both monazite and xenotime have been prepared artificially by F. 

Radominsky,1 who fused the amorphous phosphates of cerium or 

yttrium with the corresponding chlorides. This process, however, - 

sheds no light upon their genesis in nature.

According to 0. A. Derby,2 these two species, although they occur 

sparingly, are very common accessory minerals in Brazilian granites 

and gneisses. The monazito is principally found associated with 

zircon, in residues from granite, syenite, and gneiss, but not in diabase, diorite, or minette. Xenotime is a fairly constant accessory in 

muscovite granite. It was also found in a biotite gneiss, but was 

absent from .phonolites and the nepheline- or augite syenites. 0. A. 

Derby 3 also reported a titaniferous magnetite from Brazil, which 

contained monazite, and still another association of monazite .with 

graphite. On examining a number of granites and gneisses from 

New England, Derby 4 found several occurrences of monazite, and 

one of xenotime. W. Ramsay and A. Illiacus 5 also report the presence of monazite in the pegmatites of Finland. W. E. Hidden 0 

found crystals of xenotime, intergrown with zircon, in a decomposing 

granite in Henderson County, North Carolina.

Although it is an inconspicuous mineral in rocks, monazite sometimes accumulates in large quantities in residual sands, which, as a 

source of the rare earths, have important commercial value. The 

Brazilian monazite sands are described by E. Hussak and J. Reitinger,7 who give very complete analyses of several samples. In North 

Carolina 8 the sands are derived from gneiss, -and W. Lindgren 9 

reports sands of granitic origin from the Idaho Basin, Idaho.

1 Compt. Rend., vol. 80,1875, p. 304.

2 Am. Jour. Sci., 3d ser., vol. 37,1889, p. 109; vol. 41,1891, p. 308. 

»Idem, 4th ser., vol. 13,1902, p. 211. 

< Proc. Rochester Acad. Sci., vol. 1,1891, p. 198. 

» Zeitschr. Kryst. Min., vol. 31,1899, p. 317. 

«Am. Jour. Sci., 3d ser., vol. 36,1888, p. 380.

' Zeitschr. Kryst. Min., vol. 37, 1903, p. 550. Another memoir on the Brazilian sands, by A. Lisbos, 

appears in Ann. Escola de Minas, No. 0, Ouro Preto, 1903.

8 See report on monazite by H. B. C. Nitze, Sixteenth Ann. Rept. U. S. Gcol. Survey, pt. 4,1895, p. 667. 

This memoir contains a valuable bibliography. Another general paper upon monazite, thorite, and zircon, 

by P. Truchot, may be found in the Revue g<5n. sci., vol. 9,1898, p. 145, and, translated into English, in 

Chem. News, vol. 77, pp. 135,145. On the monazite sands of'Travancore, India, sec G. H. Tipper, Rcc. 

Qeol. Survey India, vol. 44,1914, p. 186.

9 Am. Jour. Sci., 4th ser., vol. 4,1897, p. 63. Also in Eighteenth Ann. Rcpt. U. S. Geol. Survey, pt. 3, 

1898, p. 677. On monazite sand in Queensland, see Bull. Imperial Inst, vol. 3,1905, p. 233; and in tho 

Malay Peninsula, idem, vol. 4, 1906, p. 301.
352 DATA OF GEOCHEMISTRY.

THE SILICA MINERALS.

Quartz. Rhombohedral. Composition, silicon dioxide, SiO2 . Molecular weight, 60.4. Specific gravity, 2.65. Molecular volume, 22.8. 

Colorless when pure, but often tinted yellow, violet, red, blue, green, 

brown, or black. Hardness, 7.

Tridymite. Hexagonal. Composition like quartz, Si02 . Specific 

gravity, 2.3. Molecular volume, 26.3. Colorless or white. Hardness, 7. Melting point, 1,710°.

Oristobalite? Pseudocubic. Composition like quartz, Si02 . Molecular weight, 60.4. Specific gravity, 2.348. Molecular volume, 25.7, 

Melting point, 1,670°.

The fused silica forms a glass, which can be worked into.flasks, 

crucibles, beakers, etc., for chemical uses. Quartz, furthermore, is 

distinctly volatile at high temperatures, as was shown in a previous 

chapter.2

Opal. Amorphous silica, carrying a variable amount of water 

(from 2 to 13 per cent). Color, white, yellow, red, brown, green, 

blue, or gray. Specific gravity, 1.9 to 2.3. Hardness, 5.5 to 6.5.

Free silica occurs in nature in many forms, quartz and opal being 

peculiarly variable species. Chalcedony, jasper, agate, flint, and 

other similar minerals are commonly regarded as cryptocrystalline 

quartz and often contain admixtures of amorphous or soluble silica 3 

with other impurities.

The different modifications of silica are readily prepared by simple 

laboratory methods. When an orthosilicate is decomposed by a 

strong acid, gelatinous silica is formed, which, upon drying, becomes 

an amorphous mass essentially identical with opal.4 The siliceous 

sinters deposited by hot springs are all classed as opal. At the hot 

springs of Plombieres, in France, common opal and hyalite have been 

formed by the action of the waters upon an ancient Roman cement.5 

The precious opal, which.fills seams, and cavities in igneous rocks, 

such as trachyte, was probably formed by the action of hot, magmatic 

water upon the silicates, the latter being first decomposed and the 

liberated silica being deposited in the hydrous form.

1 See G. vom Rath, Neues Jahrb., 1887, Band 1, p. 198; E. Mallard, Bull. Soc. min., vol. 13,1890, p. 172; 

P. Gaubert, idem, vol. 27, 1904, p. 242. The fusing temperature is given by K. Endell and R. Rieke 

(Zeitschr. anorg. Chemie, vol. 79,1912, p. 258) as 1,685°.

» See also A. L. Day and E. S. Shepherd on quartz glass, in Science, new ser., vol. 23,1906, p. 670. They 

found that quartz began to vaporize rapidly at about the temperature of melting platinum that is, between 1,700° and 1,750°.

8 For recent discussions upon the nature of chalcedony, etc., see A. Michel L6vy and E. Munier-Cbalmas, 

Bull. Soc. min., vol. 15, 1892, p. 159; and F. Wallerant, idem, vol. 20, 1897, p. 52. The fibrous varieties, 

quartzine and lutecite, are especially considered. See also H. Hein, Neues Jahrb., Beil. Band, vol. 25,1908, 

p. 182, on the relation of fibrous silica to quartz and opal. According to C. N. Fenner (Jour. Washington 

Acad. Sci., vol. 2, p. 476, 1912), chalcedony is probably a distinct form of silica. On gelatinous silica in 

an ore body, see J. H. Levings, Trans. Inst. Min. Met., vol. 21, p. 478,1911-12. On the colors of quartz, 

see T. L. Watson and R. E. Beard, Proc. U. S. Nat. Mus., vol. 53,1917, p. 553.

4 For details concerning syntheses of opal, see L. Bourgeois, Reproduction artificielle des mine'rain:, 

1884, p. 93.

& See A. Daubr6e, Etudes synth6tiquos de ge"ologie expe"rimentale, 1879, p. 189.
ROCK-FORMING MINERALS. 353

On the artificial production of quartz and tridymite there have been 

many researches. P. Schafhautl 1 simply heated a solution of colloidal silica in a Papin digester, and obtained a crystalline deposit 

of quartz. H. de Senarmont 2 heated gelatinous silica with water 

and carbonic acid, sometimes also with hydrochloric acid, at temperatures of from 200° to 300°, with similar results. A. Daubre"e 3 produced quartz, together with various silicates, by the action of silicon 

chloride at high temperatures upon lime, magnesia, glucina, or alumina. He also obtained quartz by heating water to a temperature 

below redness in a sealed glass tube; 4 and he furthermore observed 

its deposition from the waters of Plombieres.5 To K. Chrustschoff 6 

we are indebted for a series of experiments, based fundamentally 

upon the original processes of Schafhautl and Senarmont. He 

obtained quartz by heating an aqueous solution of colloidal silica to 

250° for several months. In his latest research he added hydrofluoboric acid to his solution of silica and varied the temperature. 

At 180° to 228° he obtained regular crystals, resembling the form 

of silica known as cristobalite, at 240° to 300° quartz was formed, 

and at 310° to 360° tridymite. C. Friedel and E. Sarasin 7 produced quartz by heating, in a steel tube, caustic potash, gelatinous 

silica, and amorphous alumina nearly to redness during 14 to 38 

hours. When the experiment was conducted at a higher temperature they obtained tridymite and quartz side by side. W. Bruhns,8 

upon heating powdered glass to about 300° under pressure, with^a 

weak solution of ammonium fluoride, obtained quartz; when microcline was similarly heated with hydrofluoric acid for 53 hours tridymite was formed. E. Baur 9 obtained quartz and tridymite simultaneously, as did Friedel and Sarasin, by heating a mixture of silica, 

sodium aluminate, and water for six hours to 520° in a steel bomb. 

Both species and also a soda feldspar were produced by J. Konigsberger and W. J. Miiller 10 when glass was heated to 300° and upward 

with water alone. From the filtered and slowly cooled solution 

quartz and opal were deposited; the tridymite and feldspar were 

found in the decomposed and undissolved residue. Exceptionally 

fine, doubly terminated, and clear crystals of quartz were obtained

> Cited by L. Bourgeois, Reproduction artificielle des mine'raux, 1884, p. 80. 

a Annales chim. phys., 3d sor., vol: 32,1851, p. 142. 

3 Corapt. Rend., vol. 39.-1854, p. 135.

* Etudes synthdtiques de g6ologie expdrimentale, 1879, p. 158. 

6 Idem, p. 175.

o Am. Chemist, vol. 3,1873, p. 281. Compt. Rend., vol. 104,1887, p. 602. Neues Jahrb., 1897, Band 1, p. 

240, Referate.

* Bull. Soc. min., vol. 2,1879, pp. 113,158.

8 Neues Jahrb., 1889, Band 2, p. 62.

6 Zeitschr. physikal. Chemie, vol. 42, 1903, p. 572. Questioned by A. L. Day and E. S. Shepherd, Am. 

Jour. Sci., 4th ser., vol. 22,1906, p. 276.

10 Centralbl. Min., Geol. u. Pal., 1906, pp. 339,353. The authors discuss at length the relations between 

quartz and tridymite.

113750° 19 Bull. 695 23
354 DATA OF GEOCHEMISTRY.

by E. T. Alien * when a mixture of magnesium ammonium chloride, 

sodium metasilicate, and water was heated at 400° to 450° during 

three days in a steel bomb.

All the foregoing experiments relate to the production of quartz 

and tridymite in the wet way, but dry methods have also been successfully employed. R. S. Marsden 2 reports the deposition of crystallized silica from solution in molten silver, but the first definite work 

upon this branch of the subject is due to G. Rose.3 He fused adularia 

with microcosmic salt, and amorphous silica with a deficiency of 

sodium carbonate, with borax, and with wollastonite, and in each case 

obtained tridymite. He also observed the transformation of quartz 

into tridymite by simple ignition, whereas upon fusion it yielded only 

a glass. K. Chrustschoff 4 by fusing a rock rich in quartz also 

obtained tridymite; and K. B. Schmutz,5 who melted together a 

granite, sodium chloride, and sodium tungstate, found plagioclase, 

augite, and tridymite in the subsequently'cooled mass. H. Schulze 

and A. Stelzner 6 found tridymite as an accidental product in the 

muffle of a zinc furnace; and C. Velain 7 observed it with anorthite and 

wollastonite in the glass formed by the ashes of wheat and oats during 

the combustion of a grain mill. It has also been reported by A 

Schwantke 8 as produced by the action of lightning upon a roofing 

slate. S. Meunier 9 fused silica, caustic potash, and aluminum 

fluoride together and obtained tridymite. P. Hautefeuille 10 heated 

amorphous silica with sodium or lithium tungstate to 750°, when 

quartz was formed; but at temperatures from 900° to 1,000° tridymite alone appeared. F. Parmentier,11 repeating this experiment with 

sodium molybdate, produced both quartz and tridymite, and so, too, 

did P. Hautefeuille and J. Margottet 12 with lithium chloride as the 

flux.

A. Brun 13 has transformed quartz glass into crystallized quartz by 

heating it in the vapors of alkaline chlorides to a temperature between 

700° and 750°. Above 800° and below 1,000° tridymite is formed. 

These experiments show that quartz may be produced without the 

intervention of water, but it is not always so formed. Quartz

»Cited by Day and Shepherd, op. cit., p. 297. 

* Proc. Roy. Soc. Edinburgh, vol. 11,1880, p. 37. 

s Ber. Deutsch. chem. Gesell., vol. 2,1869, p. 388. 

« Neues Jahrb., 18S7, Band 1, p. 205. 

' > Idem, 1897, Band 2, p. 147. 

»Idem, 1881, Band 1, p. 145. 

7 Bull. Soc. min., vol. 1,1878, p. 113.

s Centralbl. Min., GeoF. u. Pal., 1904, p. 87. On tridymite and cristobaHte in fire-brick, see P. G. Holmquist, Geol. For. Forhandl., vol. 33, p. 245,1911. 

s Compt. Rend., vol. Ill, 1890, p. 509. 

10 Bull. Soc. min., vol. 1,1878, p. 1.

H Cited by L. Bourgeois, Reproduction artiflcielle des mineraux, 1884, p. 81. 

12 Bull. Soc. min., vol. 4,1881, p. 244. 

« Arch. set. phy s.nat., 4th ser., vol.25,1903, p. 610. See also Vogt, Min. pet. Mitt., vol. 25,1908, p. 408.
BOCK-FORMING MINERALS. 355

crystals often eontaiu water bubbles, especially in pegmatites. 

Rhyolitic quartz may perhaps conform to Brun's observations.

In recent years several investigations have been reported which 

had for their purpose the determination of the transition point 

between quartz and tridymite. C. Johns l found that quartz sand 

was transformed to tridymite at 1,500°, and suggested that'the true 

inversion temperaturecmight be 200° lower. P. D. Quensel 2 prepared 

both minerals, first by heating a mixture of oligoclase and quartz with 

tungstic oxide and later from amorphous silica and the same flux. 

According to his data, quartz formed below 1,000° and tridymite 

above. The figures obtained by A. L. Day and E. S. Shepherd 3 are, 

however, much more precise. They found that quartz is the unstable 

form of silica at all temperatures above 800°, and will go over into 

tridymite whenever the conditions are favorable. On the other hand, 

when tridymite is fused with a mixture of potassium chloride and 

lithium chloride, quartz begins to appear at about 750°. When 

quartz glass was devitrified at 1,200°, or crystalline quartz was heated 

to the same temperature, homogeneous cristobalite was formed. 

According to E. S. Shepherd, G. A. Rankin, and F. E. Wright, 4 cristobalite can be generated in pure melts of silica. More recently also 

in the same geophysical laboratory, C. N. Fenner 5 has studied the 

stability relations of the silica minerals in much greater detail and 

reached the following conclusions: At 870° ± 10°, quartz is transformed to tridymite. At 1,470° ± 10°, tridymite passes over into 

cristobalite. The melting point of cristobalite is put by Fenner at 

1,625°, much lower than the accepted figure; that of quartz is at least 

155° lower still.

It is possible to go even further in the use of "quartz as a geologic 

thermometer," to use the significant expression of F. E. Wright and 

E. S. Larsen. 6 Quartz exists in two modifications, which differ in 

their optical properties, and which also yield different etch figures on 

treatment with cold hydrofluoric acid. One of these, a quartz, 

exists only below 575°; above that temperature it passes into /3 

quartz, the change being reversible. At ordinary temperatures all 

quartz is a. quartz; but if at any time it has been heated above 575°,

iGeol.Mag., 1906, p. 118.

2ContralbJ. Min., Geol. u. Pal., 1906, pp. 057,728.

»Am. Jour. Sci.,4th ser., vol. 22,1906, p. 276. Cf. also G. Stein, Zeitschr. anorg. Chemie, vol. 55,1907, 

p. 159. '

< Am. Jour. Sci., 1th ser., vol. 28,1909, p. 293. On cristobalite,see H. Le Chatelier, Compt. Rend., vol. 

163,1916, p. 948.

B Idem, vol. 36,1913, )>. 331. See also valuable memoirs by K. Endell and R. Rieke, Zeitschr. anorg. 

Chem., vol. 79,1912, p. 239; Mm. pet. Mitt., vol. 31,1912, p. 501; A. Smits and K. Endell, Zeitschr. anorg. 

Chom., vol. 80,1913, p. 176. Tho literature is very voluminous and can only be superficially treated here. 

The several authors named give many bibliographic references.

6 Am. Jour. Sci., 4th ser., vol. 28,1909, p. 421. Tho two modifications of quartz were first recognized by 

El. Le Chatelier, Compt. Rend., vol. 108,1SS9, p. 1046. See also O. Miigge, Neues Jahrb., Festband, 1907, 

p. 181, and other authorities cited by Wright and Larsen.
356 DATA OF GEOCHEMISTRY.

the fact is recorded in its structure as shown by its etch figures. 

Quartz, therefore, in any rock, must have been formed below 800°, 

and its peculiarities indicate whether it was crystallized below or 

above 575°. Vein quartz and the quartz of some pegmatites, were 

formed at the lower range of temperature; granitic and porphyry 

quartzes in the higher portion of the scale. . Like quartz, tridymite 

and cristobalite exist each in two modifications, a and ft; which, 

with their transition temperatures have been studied by Fenner and 

others. Silica, then, is known in at least six forms, and possibly even 

more.

In all probability quartz, tridymite, and cristobalite, are polymers 

of the fundamental molecule Si02 . Tridymite and cristobalite are 

the lower, less complex polymers, and therefore are more stable at 

high temperatures. They are, moreover, less dense than quartz, and 

quartz glass, with still lower density, probably approximates most 

nearly to the simple molecule Si02 . The true formula of quartz is 

probably not less than Si306 , and may be much higher.1 The synthetic data all bear out these conclusions and show the difficulty of 

preparing pyrogenic quartz from magmatic mixtures.

J. Morozewicz 2 has shown that when an artificial magma, preferably aluminous, is supersaturated with silica, the excess of the latter 

separates out on cooling, partly as tridymite and partly as a prismatic modification which has not been further examined. A liparite 

magma, however, containing about 1 per cent of tungstic acid, 

solidifies as a mixture of quartz, sanidine, and biotite. The function 

of the tungstic acid seems to be to liberate silica at the lower range 

of temperatures through which quartz can form, while at higher temperatures the reverse reaction takes place and silica is reabsorbed. 

These conclusions, as stated by Morozewicz, are drawn from his own 

observations, in connection with the experiments by Hautefeuille, 

which have already been cited. The formation of still a third, 

prismatic modification of silica, was also reported by Fouque" and 

L6vy,3 who obtained it by fusing an excess of silica with the elements 

of augite, enstatite, or hypersthene.

Next to the feldspars, quartz is the most abundant mineral in the 

crust of the earth. Tridymite is rare. From a discussion of about 

seven hundred analyses of igneous rocks, in comparison with their 

mineralogical characteristics, quartz appears to form about 12 per 

cent of the entire lithosphere.4 It occurs in many forms and associations as a primary mineral, as a secondary deposition, as a 

cementing substance, and as the chief constituent of quartzites and

i See F. W. Clarke, Bull. U. S. Geol. Survey No. 588,1914, p. 13.

a Min. pet. Mitt., vol. 18,1898, pp. 158-166.

» Synthese des mine'raux et-des rdches, pp. 88, 89.

« F. W. Clarke, Bull. U. 8. Geol. Survey No. 228,1904, pp. 19, 20.
BOCK-FORMING MINERALS. 357

sandstones. Porphyritic quartz is found in such eruptives as quartz 

porphyry, rhyolite, dacite, etc. Granitic quartz, which is .massive 

represents the youngest secretion in granite, syenite, diorite, etc.' 

and is peculiarly rich in liquid or gaseous inclusions. It is the surplus of silica left over after the bases have been satisfied, and, being 

probably less in amount than the eutectic ratio demands, it remains 

in solution to near the end of the solidifying process. We have 

already noted and criticized Vogt's conclusions, 1 to the effect that 

micropegmatite is a true eutectic mixture of feldspar and quartz, 

containing about 25 per cent of the latter mineral; and the glass base 

or groundmass of many rocks has similar composition. It is easy to 

understand from a consideration of the synthetic experiments why 

silica should form glass during the solidification of a magma, but 

the generation of quartz is a less simple matter. Lavas begin to 

solidify at temperatures above the transition point of quartz, and 

the development of the latter in such a rock as rhyolite is probably 

a result of very slow cooling, or even supercooling. That is, the 

temperature of the cooling mass is probably held for a long time just 

below the transition point, so that quartz forms instead of tridymite. 

The formation of quartz, especially in plutonic rocks, is possibly also 

conditioned by pressure, and it is likely that magmatic water, by 

reducing the temperature of fusion, may aid in its deposition. Under 

great pressure the denser quartz should tend to form rather than 

tridymite. The .latter mineral is characteristic of volcanic rocks, 

especially of rhyolite, trachyte, and-andesite. The occurrence of 

tridymite in Mont Pele*e has been especially studied by A. Lacroix. 2 

Rocks collected soon after the eruptions contained none of this mineral, which began to appear about six months later. Lacroix therefore regards tridymite not as an immediate crystallization from the 

magma, but as having been formed, after cooling, by the action of 

magmatic gases on the andesitic paste. In recent lavas quartz 

occurs but rarely. In some cases, however, quartz has been observed 

in basalts that is, in rocks which are. capable of assimilating, as silicates, more silica than they contain but in most instances this 

quartz is regarded as foreign and representing accidental inclusions. 

There are quartz basalts, however, in which the quartz appears to be 

an original and early secretion from the magma, and these examples 

are not easy to explain. In fact, no final explanation of them has 

yet been proposed.3 The dissociation hypothesis, offered in the

1 Sec p. 1C6. '

2 Bull. Soc. min. vol. 28,1905, p. 56. See also Lacroix on tridymite from Vesuvius, idem, vol. 31, 1908, 

p. 323.

8 See J. P. Iddings, Bull. U. S. Geol. Survey No. 66,1890, and Am. Jour, Sci., 3d ser., vol. 36,1888, p. 208, 

on quartz basalts from'New Mexico; and J. S. Diller, Bull.U. S. Gerfl. Survey -No. 79,1891, on quartz basalts 

from California. Also a note by Diller, in-Science, 1st scr., vol. 13, 1889, p. 232, on porphyritic quartz in 

eruptive rocks. In Bull. No. 79 Diller cites many references to similar rocks from other localities. Iddings 

discusses at some length the possible origin of the quartz but reaches no certain conclusions.
358 DATA OF GEOCHEMISTRY.

preceding chapter to account for the coexistence of quartz and 

magnetite, has perhaps the maximum of probability.

Secondary quartz may be produced by several processes. Certain 

hydrous silicates, like talc and pectolite, are broken down by mere 

ignition,, with liberation of free silica. .Possibly this fact may .have, 

some bearing upon the formation of quartz as a contact mineral. 

Most silicates are decomposable by percolating waters, and we have 

already seen that silica, in a greater or less amount, is almost invariably present in springs and rivers. Silica so dissolved is redeposited. 

by evaporation as opal, but when alkalies are present, according to 

G. Spezia, 1 quartz is formed. Spezia also observed that when opal 

was heated with a solution of an alkaline silicate it was transformed 

into an aggregate of quartz crystals. At high temperatures a dilute 

solution of sodium silicate dissolves quartz to some extent, but the 

latter is redeposited at lower temperatures. 2 A 5 per cent solution of 

borax, under pressure, and at 290° to 315,° attacks quartz strongly, 

but at 12° to 16°, even under very great pressure, no solution was 

noted.3 These experiments by Spezia shed much light upon the 

deposition of opal or quartz as a cementing material. There is also a 

suggestive experiment reported by Ramsay and Hunter,4 who heated 

amorphous silica with water to 200° in a sealed tube. In two days 

the silica had caked together to a granular mass of glass. The quartz 

crystals which line cavities in chalcedony or wood opal may have been 

formed by the action of alkaline silicates upon the last-named mineral. Much has been written upon the solubility of quartz, and the 

corrosion of quartz pebbles has repeatedly been noted.5 Quartz may 

be dissolved and replaced by pseudomorphs of other minerals, and 

silicates are often decomposed by percolating waters, yielding pseudomorphs of quartz. Geological literature contains innumerable 

references to replacements of this order.

THE FELDSPARS.

Ortlioclase. Monoclinic. Composition, KAlSi3O8 . Molecular 

weight, 279.4. Specific gravity, 2.56. Molecular volume, 109.1. 

Colorless, often reddish or yellowish, sometimes gray of green. Hardness, 6 to 6.5.

1 Jour. Chem. Soc., vol. 76, pt. 2,1899, p. 300. v

2 Idem, vol. 78, pt. 2,1900, p. 595.

a Idem, vol. 80, pt. 2,1901, p. 605. For Spezia's original papers, of which those notes arc abstracts, sec 

Atti Accad. Torino, vol. 31,1896, p. 196; vol. 33,1898, pp. 289, 876; vol. 35,1900, p. 750; and vol. 36, 1900-

1901. p. 631.

* Kept. British Assoc. Adv. Sci., 1882, p. 239. 

5 See C. W. Hayes, Bull. Geol. Soc. America, vol. 8,1896, p. 213; M. L. Fuller, Jour. Geology, vol. 10,

1902. p. 815; and C. H. Smyth, Am. Jour. Sci., 4th ser., vol. 19,1905, p. 277. On the chemical reactivity of 

quartz, due to its solubility, see F. Binne, Centralbl. Min., Geol. u. Pal., 1904, p. 333. On the solubility 

of quartz in alkaline solutions, as conditioned by the fineness ol its subdivision, sec G. Lunge and C. Millberg, Zeitschr. angew. Chemie, 1897, p. 393. R. Schwarz finds (Zeitschr. anorg. Chemic, vol. 76,1912, p. 422) 

that the three silica minerals are very different as regards solubility in reagents. Tridymite and cristobalite dissolve more easily and rapidly than quartz, and quartz glass more easily still.
BOCK-FORMING MINERALS. 359

Microcline. Triclinic. Composition, specific gravity, hardness, 

etc., like orthoclase.

Albite. Triclinic. Composition, NaAlSi308. Molecular weight, 

A - 263.3. Specific gravity, 2.605. Molecular volume, 101.1. Colors as

in orthoclase, commonly white. Hardness, 6 to 6.5.

v Anorthoclase. Triclinic. Intermediate in composition between 

albite and microcline.

Anorfhite. Triclinic. Composition, CaAl2Si208 . Molecular weight, 

279.1. Specific gravity, 2.765. Molecular volume, 100.9. Fuses at

 > 1,550°. Color, white, grayish, reddish. Hardness, 6 to 6.5.

There are several minor additions to be made to this list. A 

monoclinic equivalent of albite appears to occur as an admixture in 

many examples of orthoclase, and sometimes is in excess of the potassium compound. According to P. Barbier and A. Prost 1 this soda 

orthoclase is very nearly represented by a supposed albite from

 4 Kragero, Norway. Similarly, sodium may replace calcium in anorthite, forming a triclinic isomer of nephelite, with the formula

"^ NaaALjSijjOg. This compound has been prepared synthetically, and 

also identified by H. S. Washington and F. E. Wright 2 as a constituent of a feldspar from the island of Linosa, east of Tunis. For the 

sodium anorthite itself, they propose the name carnegieite, and for 

the mixed feldspar, in which it is associated with albite and anorthite, 

the name anemousite.

The mineral celsian may be a barium anorthite, BaAl2Si2O8 . 

Hyalophane is another barium feldspar, which, however, is monoclinic, and appears to be a mixture of a salt like celsian with orthoclase. Traces of barium are often found in feldspars.

> Albite and anorthite form the extreme ends of a series of minerals 

known as the plagioclase feldspars. Several stages of mixture in this 

series have received distinctive names, as shown "below. The symbols 

Ab and An represent albite and anorthite, respectively:

Oligoclase........................................Ab6Anj to AbgAn^

Andesine.......................................... AbgA^ to Abj Auj.

Labradorite........................................ AbjAnj to A^Aiig.

Bytownite........................................ AbjAiig to A^An,..

These feldspars are generally regarded as isomorphous mixtures of 

the two end species; but some authorities consider them as representing definite compounds, which, in their turn, may commingle 

isomorphously in any proportion.3 The prevalent opinion, however, 

seems to be fully confirmed by the most recent investigations, especially by those of A. L. Day and his colleagues, E. T. Alien, R. B.

i Bull. Soc. chim., 4th scr., vol. 3,1908, p. 894. W. T. Schaller (Am. Jour. Sci., 4th scr., vol. 30,1910, p. 

358) proposes to name this soda orthoclase barbicritc.

a Am. Jour. Sci., 4th scr., vol. 29,1910, p. 52. For synthetic data see N. L. Bowen, Am. Jour. Sci., 4th 

sor., vol. 33,1912, p. 551. He gives references to earlier literature.

a See, for example, W. Tarrasscako, Zcitschr. Kryst. Min., vol. 36, p. 182,1602.
360 DATA OF GEOCHEMISTRY.

Sosman, and N. L. Bowen, 1 whose determinations of melting points 

form a regular linear series. The latest figures, representing complete 

fusion, by Bowen, are as follows:

Melting points of feldspar.

An.............................. 1,550

AbiAn5.......................... 1, 521

AbjAiv.......................^. 1,490

AbjAn,.......................... 1,450

Ab^........................... 1,394

AbgAn!....... .I.................. 1, 362

Ab4Anx ....:.................... 1, 334

AbgAn!......................... 1,265

These figures give a regular curve, but as the albite end of the 

series is approached the mixtures become too viscous to admit of 

good melting-point measurements. It should be noted that the 

observations were made upon artificial preparations of great purity.

Of all the feldspars anorthite is the one most easily made pyrogenically. In the investigation by Day and Alien just cited it was 

prepared without difficulty by simply fusing its constituent oxides 

together; and this observation is in accord with the results obtained 

by previous experimenters. J. H. L. Vogt 2 observed its formation 

in slags, and J. Morozewicz 3 repeatedly obtained feldspars varying 

from labradorite to nearly pure anorthite in his experiments with 

artificial magmas. Fouqu6 and LeVy 4 obtained anorthite directly 

from its constituents; and S. Meunier,5 upon fusing silica, lime, and 

aluminum fluoride together, found sillimanite, tridymite, and anorthite in the resultant mass. Anorthite is also formed by the breaking down of other more complex silicates. A. Des Cloizeaux,6 by fusing garnet and vesuvianite, obtained crystals which Fouqu<3 and LeVy 

.identified as anorthite; and similar results are reported, with much 

more detail, by C. Doelter and E. Hussak.7 Doelter 8 also found 

anorthite among the products formed by fusing epidote, axinite, chabazite, and scolecite. Finally, C. and G. Friedel 9 prepared anorthite 

in the wet way by heating muscovite with lime, calcium chloride, and 

a little water to 500° in a steel tube. Feldspars analogous to anorthite, oligoclase, and labradorite, but containing strontium, barium, 

or lead in place of calcium, were also obtained by Fouqu6 and LeVy 10 

when mixtures of silica, alumina, sodium carbonate, and the proper 

monoxide were heated together to temperatures a little below the 

point of fusion. Plagioclase feldspars containing potassium have

1 Day and Alien, Am. Jour. Sci., 4th ser., vol. 19,1905, p. 93. Day and Sosman, idem, vol. 31,1911, p. 

341. Bowen, idem, vol. 35, 1913, p. 577.

2 Mineralbildung in Schmelzmassen, p. 181. . . .

3 Min. pet. Mitt., vol. 18,1898, p. 156. 

« Synthfese des mine'raux et des roches, p. 138. 

6 Compt. Rend., vol. Ill, 1890, p. 509. 

o Manuel de mine'ralogie, vol. 1,1862, pp. 277, 543. 

i Neues Jahrb., 1884, Band 1, p. 158.

8 Idem, 1897, Band 1, p. 1; Allgemeine und chemische Mineralogie, p. 183. 

s Compt. Rend., vol. 110,1890, p. 1170. 

"> Synthese des mine'raux et des roches, p. 145.
ROCK-FORMING MINERALS. 361

been made synthetically by E. Dittler. 1 A microcline from the 

Hmen Mountains, described by W. Vernadsky, 2 contained rubidium 

to the extent of 3.12 per cent E,b20.

All attempts to prepare the alkali feldspars by simple dry fusion 

have failed. Whether the constituent substances are taken or the 

natural minerals themselves are fused, the product is always a glass, 

without any distinct evidences of crystallization. Anorthite, as we 

have seen, crystallizes easily, and the intermediate feldspars, which 

form without difficulty near the anorthite end of the series, become 

more and more unmanageable as we approach albite. This fact was 

observed by Fouque* and LeVy 3 and corroborated by Day and Alien, 

the latter having also shown that the viscosity of the alkaline compounds impedes their crystallization, at least within any reasonable 

time which can be allowed for a laboratory experiment. Albite, however, may be recrystallized, as J. Lenarcic 4 has shown, when it is 

fused with half its weight of magnetite. The mixture forms a mobile 

liquid in which crystallization can take place. Other substances 

also render crystallization possible. P. Hautefeuillo 5 heated an 

alkaline alumosilicate of sodium to 900°-1,000° with tungstic acid 

and obtained albite. A similar experiment with a potassium alumosilicate yielded orthoclase, 0 and a mixture of silica, alumina, and 

acid potassium tungstate gave the same result. By heating a potassium alumosilicate mixture with alkaline phosphates to which an 

alkaline fluoride had been added, Hautefeuille 7 produced both quartz 

and orthoclase, and a potassium feldspar was also obtained by Doelter 8 when a mixture corresponding to KAlSi04 was fused with potassium fluoride and silicofluoride. How these extraneous substances 

act is not clear. Day and Alien,9 repeating a part of Hautefeuille's 

work, heated a powdered albite glass with sodium tungstate and 

succeeded in bringing about crystallization. The fragments of glass, 

however, became crystalline without change of form, and their outlines were unaltered that is, the transformation from the vitreous 

to the crystalline modification took place without solution of the 

material. The mechanism of this reaction is quite unexplained.

By hydrochemical means the alkali feldspars are more easily prepared. C. Friedel and E. Sarasin 10 heated gelatinous silica, precipitated alumina, and caustic potash together, with a little water, to 

dull redness in a steel tube. Quartz and orthoclase were produced. 

In a later investigation 11 they heated a mixture having the composition of albite, with an excess of sodium silicate, to about 500° and 

obtained albite. The same process, essentially, was followed by K.

' Min. pet. Mitt., vol. 29,1910, p. 273. ' Idem, vol. 90, 1880, p. 830.

» Bull. Soc. min., vol. 30,1914, p. 258. 8 Neues Jahrb., 1897, Band 1, p. 1.

« Synth&se des mineraux et des roches, pp. 142-145. 9 Am. Jour. Sci., 4th scr., vol. 19.1905, p. 117.

« Centralbl. Min., Gcol. u. Pal., 1903, p. 705. ><> Compt. Rend., vol. 92,1881, p. 1374.

6 Compt. Rend., vol. 84,1877, p. 1301. " Idem, vol. 97,1883, p. 290.

e Idem, VoL 85, 1877, p. 952.
362 DATA OP GEOCHEMISTRY.

Chrustschoff, 1 who heated an aqueous solution of dialyzed silica with 

a little alumina and caustic potash to 300° during several months, 

when quartz and orthoclase formed. C. and G. Friedel 2 also prepared orthoclase by heating muscovite with potassium silicate and 

water to 500°. In a series of experiments in which amorphous silica 

was heated with potassium or sodium aluminate and water to 520° 

in a steel bomb, E. Baur 3 determined the conditions under which 

quartz alone, feldspar alone, or both together, could form. When 

the silica was in excess, quartz appeared; with silica and the aluminate in nearly equal proportions, both minerals crystallized; when 

the aluminate preponderated in the mixture, only feldspar formed.

The feldspars, are by far the most abundant of all the minerals and 

form nearly 60 per cent of the material contained in the igneous 

rocks.4 Among the latter only the pyroxenites, peridotites, leucitites, 

and nephelinites contain no feldspars, or at most contain them in 

quite subordinate quantities. The monoclinic alkali feldspars are 

especially characteristic of the more siliceous plutonic rocks, although 

they also occur in many eruptives and in metamorphic schists. In 

granite, for example, orthoclase, quartz, and muscovite are the conspicuous minerals. Albite is also found under similar conditions. 

In the less siliceous rocks, such as gabbro or basalt, the plagioclases 

are more abundant, and the feldspars approach anorthite in composition as the proportion of silica in a magma decreases. This statement, however, must be construed as indicating a tendency, not as 

the formulation of a distinct rule. The more siliceous rocks contain 

preferably the more siliceous feldspars, and vice versa. Anorthite 

has also been repeatedly observed in meteorites, and it is not uncommon as a contact mineral in limestones. 5 Orthoclase, probably of 

aqueous origin, sometimes occurs as a gangue mineral in metalliferous 

fissure veins.0

The feldspars, furthermore, have repeatedly been found in sedimentary limestones and even in dolomite. According to R. A. Daly,7 

who has summed up the evidence, albite and orthoclase have crystallized in calcareous marine muds at temperatures lower than 100°, and 

probably below 70°. In the dolomite of Waterton, Alberta, Canada, 

Daly found 34.5 per cent of orthoclase and 3.1 per cent of albite.

1 Compt. Kend., vol. 104,1887, p. 602.

2 Idem, vol. 110,1890, p. 1170.

8 Zcitschr. physikal. Chemie, vol. 42,1903, p. 567. The paper is illustrated by diagrams"based upon the 

phase rule.

* See F. W. Clarkc, Bull. U. S. Geol. Survey-No. 419,1910, p. 9.

G For example, crystals of anorthite occur with epidote in the limestone of Phippsburg, Maine, and also 

with garnet, scapolite, etc., at Raymond, Maine. See Bull. U. S. Geol. Survey No. 113,1893, p. 110, and 

Bull. No. 167,1900, p. 69. C. H. Warren (Am. Jour. Sci., 4th ser., vol. 11,1901, p. 369) describes crystals 

of anorthito from the limestone of Franklin, New Jersey, near its contact with granite.

6 W. Lindgren (Am. Jour. Sci., 4th ser., vol. 5,1898, p. 418) has described an occurrence of this kind near 

Silver City, Idaho. He gives a number of references to other localities.

7 Proc. Nat. Acad. Sci., vol. 3,1917, p. 659. Daly gives references to earlier literature.
BOCK-FORMING MINERALS. 363,

The feldspars are all highly alterable minerals, and their alteration 

products are both numerous and important. They are attacked by 

water alone, more so by water containing carbon diqxide, and still 

more vigorously by acid waters, such as issue from volcanic vents or 

are formed by the oxidation of sulphides. Alkaline solutions also 

exert a powerful decomposing action upon this group of silicates. 

Among the many experiments relative to this class of reactions those 

qf A. Daubre"e * are perhaps the most classic. Fragments of orthociase were agitated with water alone by revolution in a cylinder of 

iron during 192 hours. From 5 kilograms of the feldspar 12.6 grams 

of K20 were thus extracted and found in the filtered solution. To 

water charged with carbon dioxide 2 kilograms of orthociase, after 

10 days of agitation, yielded 0.27 gram of- K20, with 0.75 gram of 

free silica. With alkaline solutions, especially at elevated temperatures and under pressure, the changes are even more striking, as shown 

by J. Lemberg's investigations.2 Labradorite, heated 324 hours to 

215° with a sodium carbonate solution, yielded cancrinite. Other 

feldspars, similarly treated, but with variations in detail, were transformed into analcite. With glasses formed by the fusion of feldspars, 

and with potassium carbonate, zeolites of the chabazite and phillipsite series were produced.

. The end products of the alteration of feldspars are commonly 

kaolinite and quartz. Other hydrous silicates of alumina are probably 

also formed. When the alkalies have not been wholly withdrawn 

muscovite is a common alteration product. Many of the zeolites are 

generally interpreted as hydrated feldspars, those which contain lime 

having been derived from plagioclase. From anorthite calcite may be 

formed. Scapolites, 3 epidote, and zoisite are also not uncommon 

derivatives of feldspars. Finally, by substitution of bases, one feldspar may pass into another, as in the alteration of orthociase into 

albite. 4 . .

LETJCITE AND ANALCITE.

Leucite. Isometric. Composition, KAlSi3O6 . Molecular weight, 

219. Specific gravity, 2.5. Molecular volume, 87.6. Color, white to 

gray. Hardness, 5.5 to 6. Fuses at about 1,420°.

Analcite. Isometric. Composition, NaAlSi206 .H2 0.. Molecular 

weight, 220.9. Specific gravity, 2.25. Molecular volume, 98.2. 

Colorless or white, sometimes tinted by impurities.5 Hardness, 5 

to 5.5.

> Etudes synthe"tiqucs dc ge"ologie cxpe"rimcntalc, 1879, pp. 268-275. 

2 Zeitschr. Doutsch. geol. Gcsell., vol. 39,1887, p. 559.

» Sec J. W. Judd, Mineralog. Mag., vol. 8,1889, p. 180, on the alteration of plagioclase into scapolitc. 

* For an example of this kind see F. A. Gcnth, Proc. Am. Philos. Soc., vol. 20,1882, p. 392. 

o On variations in the composition of analcite, see H. W. Foote and W. M. Bradley, Am. Jour. Sci., 4tli 

scr., vol. 33,1912, p. 433.
364 DATA OF GEOCHEMISTRY.

Although leucite and analcite are widely separated in mineralogical 

classification, one being placed near the feldspars and the other 

among the zeolites, they belong chemically together. They are similar in form and in composition, and are connected by so many relations that they can not be adequately studied apart. Analcite, to be 

sure, differs from leucite in respect to hydration, but G. Friedel* has 

shown that its water is not a part of the essential crystalline molecule. 

When heated in sealed tubes with dissociating ammonium chloride, 

leucite and analcite both yield the same ammonium derivative,2 

NH4AlSi206. Furthermore, as the experiments of J. Lemberg3 and 

S. J. Thugutt 4 have shown, the two species are easily convertible, the 

one into the other. When leucite is heated to 180°-195° with a solution of sodium chloride or sodium carbonate, analcite is formed. 

Analcite, similarly treated with potassium salts, is converted into 

leucite. E. A. Stephenson 5 has obtained analcite by the action of 

solutions of sodium bicarbonate or carbonate upon adularia at temperatures ranging from 183° to 233°.

Leucite and analcite are easily prepared synthetically. Leucite 

can be formed by simply fusing together its constituent oxides and 

cooling the mass slowly. This process was followed by Fouque" and 

LeVy,6 who also formed leucite, with other minerals, from various 

artificial magmas.7 By fusion of its constituents with potassium vanadate, P. Hautefeuille 8 obtained measurable crystals of leucite. The 

same result followed the fusion of muscovite with potassium vanadate. 

Syntheses of leucite by indirect methods, with the intervention of 

fluorides or of silicon chloride, have also been effected by S. Meunier 9 and A. Duboin.10 C. Doelter, 11 by fusing a mixture equivalent 

to Al2 03 + 2Si02 with sodium fluoride, prepared a soda leucite, 

NaAlSi206.

When microcline and biotite are fused together, leucite appears 

among the products; 12 and Doelter 13 found that it was formed when 

muscovite, lepidolite, or zinnwaldite was fused alone. It was also 

produced hydrochemically by C. and G. Friedel 14 when muscovite was 

heated to 500° in a steel tube with silica and a solution of potassium 

hydroxide.

> Bull. Soc. min., vol. 19,1896, p. 363.

» F. W. Clarke and G. Steiger, Bull. U. S. Geol. Survey No. 207,1902.

a Zeitschr. Deutsch. geol. Gesell., vol. 28,1876, pp. 537 ot seq.

4 Mineralchemische Studien, Dorpat, 1901, pp. 100,101.

«Jour. Geology, vol. 24,1916, p. 180.

6 Synthese des mine'raux et des roches, p. 153.

i Bull. Soc, min., vol. 2,1879, p. Ill; vol. 3,1880, p. 118.

6 Cited by L. Bourgeois, Reproduction artiflcielle des mine'raux, p. 130. .

8 Compt. Rend., vol. 90,1880, p. 1009; vol. Ill, 1890, p. 509. 

»o Idem, vol. 114,1892, p. 1361. 

" Neues Jahrb., 1897, Band 1, p. 1.

12 Fouqu6 and L6vy, Synthese des mine'raux et des roches, p. 77. 

> 3 Loc. cit. 

" Compt. Rend., voL.110,1S90, p. 1170.
ROCK-FORMING MINERALS. 365

The syntheses of analcite have all been effected under pressure, and 

in the wet way. A de Schulten 1 heated sodium silicate, caustic soda, 

and water, in contact with aluminous glass, at a temperature of 180° 

to 190°. He also produced analcite by heating a solution of sodium 

silicate with sodium aluminate, in proper proportions, to 180° for 

eighteen hours.2 C. Friedel and E. Sarasin 3 prepared analcite by 

heating precipitated aluminum silicate with sodium silicate and water 

to 500° in a sealed tube. J. Lemberg 4 derived analcite from andesine 

and oligoclase by prolonged heating with sodium carbonate solutions 

at 210° to 220°. These transformations illustrate the ready formation 

of analcite as a secondary mineral. They are not, however, all strictly 

similar. Analcite derived from leucite can be transformed into leucite 

again, as we have already seen; but according to S. J. Thugutt 5 the 

reaction with andesine is not reversible. The two alterations, therefore, are chemically unlike. Analcite may also be generated by alteration from elseolite and segirite.6 When formed with other zeolites, 

it is the earliest one to appear.

Leucite is a mineral characteristic of many recent lavas but not 

found in the abyssal rocks. Its absence from the latter and older 

depositions may be due to its easy alteration into other species; but 

such an explanation is of course only tentative. Its formation takes 

place only when the potassium of a magma is in excess over the 

amount required to form feldspars. When the excess is small, leucite 

and feldspar may both appear; when it is large enough, leucite alone 

forms. Comparatively speaking, it is rather a rare mineral; a fact 

which is possibly explained by some observations of A. Lagorio. 7 In 

an artificial leucite-tephrite magma, kept at a red heat, the difficultly 

fusible leucite crystallizes out. If,, then, the temperature is raised, 

the mineral redissolves; if lowered, the mass becomes so viscous that 

the crystallization of leucite ceases. In brief, the formation of leucite 

seems to be possible only through a very narrow range of temperatures, and the favorable conditions do not often occur.8

Analcite is most frequently found as a secondary mineral, the product of zeolitization; and until recent years it was supposed to have 

no other origin. It was often noted in eruptive rocks, but it was 

supposed to be always a product of alteration. It is now gene'rally 

recognized, however, that analcite may occur as an original pyrogenic 

mineral; but, being a hydrated species, it can so appear only in 

deep-seated rocks, where it has been formed under pressure. - W. Lindi Compt. Rend., vol. 90,1880, p. 1493; Bull. Soc. min., vol. 3,1880, p. 150. 

"Idem, vol. 94,1882, p. 96. 

3 Idem, vol. 97,1883, p. 290.

« Zoitschr. Deutsch. geol. Gesell., vol. 39,1887, p. 559. 

» Neues Jahrb., Beil. Band 9,1894-95, p. 604.

« See W. C. Brogger, Zeitschr. Kryst. Min., vol. 16,1890, pp. 223, 333. 

' Zcitsehr. Kryst. Min., vol. 24,1895, p. 293.

s On the formation of leucite in igneous rocks, see H. S. Washington, Jour. Geology, vol. 15, 1907, pp. 

257, 357.
366 DATA OF GEOCHEMISTRY.-

gren, 1 for example, identified it in the sodalite syenite of Square 

Butte, Montana. In certain rocks analcite has probably been erroneously identified as glass; for instance, in the monchiquites, which 

L. V. Pirsson 2 interprets as analcite basalts equivalent to the similar 

leucite lavas. W. Cross,3 has described an analcite basalt from near 

Pikes Peak, Colorado, and has also identified primary analcite in the 

phonolites of Cripple Creek.4 The groundmass of a tinguaite from 

Manchester, Massachusetts, according to H. S. Washington,5 consists 

of analcite and nepheline; and J. W. Evans c has identified the mineral in a monchiquite from Mount Girnar, India. In the last instance 

some of the analcite has been transformed into a mixture of feldspar 

and nepheline. The extreme case of an analcite rock, however, is 

the heronite from Heron Bay, Lake Superior, described by A. P. 

Colexnan.7 This is a dike rock containing analcite, plagioclase, orthoclase, and segirine, in which the analcite forms 47 per cent of the mass. 

In the analcite diabase described by H. W. Fairbanks, 8 the analcite 

may have been derived from nepheline. It is partly replaced by 

feldspar and partly altered into a mineral which may be prehnite. 

Analcite also alters into kaolin. 9

Alterations of leucite into analcite have been repeatedly observed, 

as in the Saxon Wiesenthal 10 and in the Highwood Mountains, Montana. 11 The most notable transformation of leucite, however, is into 

pseudomorphs of mixed orthoclase and nepheline. 12 The "pseudoleucite" crystals of Magnet Cove, Arkansas, are a mixture of this

kind.

THE NEPHELITE GBOTJP.

NepJielite or elseolite. Hexagonal. Simplest empirical formula, 

NaAlSi04 . Corresponding molecular weight, 142.5. Specific gravity, 2.55 to 2.65. Molecular volume, 54.8. Melting point, 1,526°, 

Bowen. Normally white or colorless; often tinted yellow, gray, 

greenish, or reddish by impurities. Hardness, 5.5 to 6.

1 Am. Jour. Sci., 3d scr., vol. 45,1893, p. 286.

2 Jour. Geology, vol. 4,1896, p. 679.

a Idem, vol. 5,1S97, p. 684.

< Sixteenth Ann. Kept. U. S. Geol. Survey, pt. 2,1895, p. 36. . .

5 Am. Jour. Sci., 4th ser., vol. 6,1898, p. 182.

6 Quart. Jour. Geol. Soc., vol. 57,1901, p. 38. *

7 Jour. Geology, vol. 7,1899, p. 431.

8 Bull. Dept. Geology Univ. California, vol. 1, 1895, p. 273. See also B. R. Young, Trans. Edinburgh 

Geol. Soc., vol. 8,1903, p. 326, on analcite diabase in Scotland; C. W. Knight, Canadian Rec. Sci., vol. 9, 

1905, p. 265, on an analcite-trachyte tuff from southwestern Alberta; and A. Pelikan, Min. pet. Mitt., vol. 

25,1906, p. 113, on two analcite phonolites from Bohemia. Essexites and teschenites from western Scotland, rich in primary analcite, are described by G. W. Tyrrell, Trans. Geol. Soc. Glasgow, vol. 13, 1909, 

p. 299, and Geol. Mag., 1912, pp. 66,120. On analcite basalts from Sardinia, see H. S.. Washington, Boll. 

Soc. geol. ital., vol. 33,1914, p. 147. A still later paper on primary analcite, by J. D. MacKenzie, is published 

in Am. Jour. Sci., 4th ser., vol. 39,1915, p. 571, and another by A. Scott in Trans. Geol. Soc. Glasgow, 

vol. 16, pt. 1,1916, p. 34.

o W. C. Broggcr, Zeitschr. Kryst. Min., vol. 16,1890, p. 199. : w See A. Sauer, Zeitschr. Dcutsch. geol. Gesell., vol. 37,1885, p. 452.

» W. H. Weed and L. V. Pirsson, Am. Jour. Sci., 4th ser., vol. 2,1896, p. 315.

12 See Sauer, loc. cit.; J. F. Williams, Ann. Kept. Geol. Survey Arkansas, 1890, vol. 2, p. 267; E. Hussak, 

Neucs Jahrb., 1890, pt. 1, p. 166; and E. Scacchi, Rcndiconti Accad. Napoli, vol. 24, p. 315.
ROCK-FORMING MINERALS. 367

" Kaliophilite or "plmcdite. rHexagonal. Composition, 

Molecular weight, 158.6. Specific gravity, 2.5 to 2.6. Molecular 

volume, 6.1. Colorless. Hardness, 6.

Eucryptite. Hexagonal. Composition, LiAlSi04 . Molecular 

weight, 126.5. Specific gravity, 2.67. Molecular volume, 47.3. 

Colorless or white. Only known as produced by the alteration of 

spodumene.

Kaliophilite and eucryptite are rare minerals, having slight geological significance. They are included here because of the light they 

shed upon the composition of nephelite. The formula given for 

the latter species is analogous to the formulae of kaliophilite and 

eucryptite, and is also that of the artificial mineral. Natural nephelite or elseolite always varies from the' theoretical composition, and 

approximates more nearly the formula Na6K2Al8Si9034. This variation is probably due, first, to isomorphous admixtures of kaliophilite, 

and possibly also to the presence of silica or albite as impurities in 

the normal orthosilicate. This supposition is put in more definite 

shape by H. W. Foote and W. M. Bradley,1 who regard natural 

nephelite as the normal compound with other silicates or silica 

present in " solid solution." The same hypothesis may explain the 

similar variations in cancrinite, sodalite, and other species. The 

expression "solid solution," however, should be used with caution. 

It probably confuses a number of different phenomena, to which 

specific names quite properly belong. Isomorphous mixtures or 

mix-crystals are well known; occlusion describes another form of impurity; a solid (or solidified) solution like glass is not at all the same 

as either of the others. Under the name pseudonephelite F. Zambonini 2 has described a normal isomorphous mixture from Capo 

di . Bove having the formula (Na,K)AlSi04 . The equivalency of 

nephelite and kaliophilite is well shown by an experiment of J. Lemberg.3 He heated elaeolite one hundred hours to 200° with a solution 

of potassium silicate, and obtained an amorphous product having 

the composition KAlSiO^.

P. Hautefeuille 4 prepared an artificial nephelite by fusing a mixture of silica and sodium aluminate with a flux of lithium vanadate. 

Fouque and Levy 5 obtained the mineral more directly by fusing its 

constituents together, and so, too, did C. Doelter." Doelter's prepara1 Am. Jour. Sci., 4th ser., vol. 31, 1911, p. 25; vol. 33, 1912, p. 439. Other recent discussions of the constitution of nophelite are by J. Morozewicz, Bull. Acad. Sci. Cracow, 1907, p. 958; Silvia Hillcbraud, 

Sitzungsb. Akad. Wien, vol. 119, pt. 1, 1910; S. J. Thugutt, Compt. Rend. Soc. Sci. Warsaw, 1913, p. 850; 

W. T. Schallor, Zeitschr. Kryst. Min., vol. 50, 1912, p. 343; and N. L. Bowen, Am. Jour. Sci., 4th sor., vol.33, 

1912, p. 551. A later paper by Bowen, on artificial mixtures of nephelite and kaliophilite,is in Am. Jour. 

Sci., 4th ser., vol. 43, 1917, p. 115.

2 Jour. Chem.Soc., vol. 98, pt. 2, 1910, p. 1078. Abst. from Rend. Accad. sci. us. mat. Napoli, 1910.

a Zoitschr. Deutsch. geol. Gcsell., vol. 37, 1885, p. 96G.

* Cited by fouqud and L6vy, Synthese des mjne'uaux ct des roch.es, p. 155.

6 Loc. cit. \

6 Zeitschr. Kryst. Min., vol. 9, 1884, p. 321.
368 DATA OF GEOCHEMISTRY. ,

tion agreed closely with the empirical formula NaAlSi04 . According to Fouque" and L6 vy, nephelite is one of the minerals which crystallize most easily from fusion. S. Meunier 1 prepared nephelite less 

simply, by fusing silica, alumina, and soda with cryolite; and A. 

Duboin 2 effected the synthesis of kaliophihte when potassium fluoride, alumina, and silica or potassium fluosilicate were fused together. 

By similar processes Doelter 3 obtained both nephelite and kaliophilite. C. q-nd G. Friedel 4 converted muscovite into nephelite by beating with solution of caustic soda to 500° in a steel tube. The presence of nephelite in pseudomorphs after leucite was noted in the 

description of the latter mineral. An amorphous silicate having the 

composition of nephelite was obtained by R. Hoffmann 5 when kaolin 

and dry sodium carbonate were heated together, and a similar result 

was reached by A. Gorgeu 6 and P. G. Silber.7 - When Gorgeu heated 

kaolin with potassium iodide, a salt like kaliophihte was formed. In 

these reactions the temperature was kept below that at which the 

materials would sinter together. According to S. J. Thugutt,8 when 

natural nephelite is subjected to the action of superheated water it 

breaks up into natrolite, gibbsite, and muscovite.

Nephelite is rarely found except in igneous rocks.9 The glassy 

crystallized variety found in recent lavas is commonly known by the 

first name of the species; the massive, opaque, or coarsely crystalline 

mineral of the older rocks is called elseolite. Phonolite, nephelinite, 

nepheline basalt, and elseolite syenite are among the important rocks 

in which nephelite is ah essential species. Its presence, indicates an 

excess of soda in a magma over the amount required to form feldspars, and it is one of the latest minerals to be deposited.10 In a 

nepheline syenite from an island off the coast of Guinea, A. Lacroix " 

found crystals of sodium fluoride, NaF. This new mineral species 

he named villiaumite.

Nephelite and elseolite are peculiarly subject to alteration.12 Natrolite, analcite, hydronephelite, thomsonite, sodalite, muscovite, and 

kaolin are among the products thus formed. Eucryptite also alters

i Compt. Rend., vol. Ill, 1890, p. 509. 

a Idem, vol. 115,1892, p. 56.

3 Neues Jahrb., 1897, Band 1, p. 1. . 4 Compt. Rend., vol. 110,1890, p. 1170. By the same process, using caustic potash instead of soda, G. 

Friedel effected the synthesis of kaliophilite: Bull. Soc. min., vol. 35, p. 470, 1912. Recent syntheses of 

nephelite, kaliophilite, and eucryptite by direct fusion are described by A. S. Ginsburg, Zeitschr. anorg. 

Chemie, vol. 73,1912, p. 277.

6 Liebig's Annalen, vol. 194,1878, p. 5.

6 Annales chim. phys., 6th ser., vol. 10,1887, p. 145.

' Ber. Deutsch. chera. Gesell., vol. 14,1881, p. 941.

s Jour. Chem. Soc., vol. 114, pt. 2,1918, p. 449. Abstract.

9 Nephelite is reported by Max Bauer (Neues Jahrb., 1896, Band 1, p. 85; 1897, Band 1, p. 258) in certain 

crystalline schists, and also associated with chlorite in jadeite.

10 See the experiments of J. Morozewicz, Min. pet. Mitt., vol. 18,1898, pp. 1,105. Comparealso J. LenarCic', 

Centralbl. Min., Geol. u. Pal., 1903, pp. 705, 743. 

'» Compt. Rend., vol. 146,1908, p. 213. 

12 See W. C. Brogger, Zeitschr. Kryst. Min., vol. 16,1890, pp. 223 et seq.
BOCK-FORMING MINERALS. 369

into muscovite. 1 This indicates that the simplest empirical formulas of the nephelite minerals should be tripled, for the formula of 

muscovite is Al3 (Si04 ) 3KH2 .

THE CANCBINITE-SODALITE GROUP.

. Cancrinite. Hexagonal. Composition uncertain, but probably 

best represented by the formula Al3Na4HCSi3 015 . Corresponding 

molecular weight, 511.5. Specific gravity, 2.4. Molecular volume, 

213. Color commonly yellow, but also white, gray, greenish, bluish, 

or reddish. Hardness, 5 to 6.

Socialite. 2 Isometric. Composition normally Al3Na4Si3012Cl, but 

variable. Molecular weight, 486. Specific gravity, 2.2. Molecular 

volume, 221. Color, white, gray, greenish, yellowish, reddish, very 

often bright blue. Hardness, 5.5 to 6.

Hauynite. Isometric. Composition, Al3Na3CaSSi3 01(), but varying in the 0 relative proportions of Na and Ca. Molecular weight, 

563.6. Specific gravity, 2.4 to 2.5. Molecular volume, 230. Color, 

blue, green, red, or yellow. Hardness, 5.5 to 6.

Noselite or nosean. Isometric. Composition like haiiynite, but 

without calcium, Al3Na5SSi3O16 . Molecular weight, 569.5. Specific 

gravity, 2.25 to 2.4. Molecular volume, 242. Color, gray, bluish, or 

brownish. Hardness, 5.5.

Chemically, these four minerals, together with lapis lazuli and the 

rarer microsommite, are to be classed as derivatives of nephelite, 

with which they are.commonly associated. Their exact composition 

is still somewhat uncertain. The formula assigned to canciinite is 

that developed by F. W. Clarke; 3 the three isometric species are 

written as interpreted by W. C. Brogger and H. Backstrom, 4 who 

have shown their relationship to the garnet group. Under sodalite, 

however, more than one compound may be included, as the experiments of J. Lemberg 5 and S. J. Thugutt ° seem to indicate. The two 

last-named authorities regard these minerals as double molecular 

compounds of a silicate like nephelite with sodium carbonate, chloride, sulphate, etc. In support of this view Thugutt prepared a large 

number of artificial compounds in which the sodium chloride of sodalite wT as replaced by other salts; but the new substances differed from

1 See 0. J. Brush and E. S. Dana, Am. Jour. Sci., 3d ser., vol. 20,1880, p. 260.

2 A variety of sodalite containing some sulphur has been named hackmannite by L. H. Borgstriim, 

Zeitschr. Kryst. Min., vol.37,1903,p. 284. A sodalite from Monte Somma containing molybdenum is 

described by F. Zambonini, Mineralogia \7 esuviana, p. 214, under the name molybdosodalite. A sulphatic 

cancrinito from Colorado has been described by E. S. Larsen and G. Steiger, Am. Jour. Sci., 4th sor., vol. 

42,1917, p. 332.

» Bull. U. S. Geol. Survey No. 588,1914, p. 27.

«Zeitschr. Kryst. Miu., vol. 18,1891, p. 209.

i- Zeitsshr. Doutsch. geol. Gesell., vol. 37,1885, p. 969.

« Mineralchemische Studien, Dorpat, 1891.

113750° 19 Bull. 695 24
370 DATA OF GEOCHEMISTRY.

the natural minerals in containing water of crystallization. 1 A discussion of these salts, however, would lead us too far afield.

An artificial cancrinite was obtained by Lemberg 2 when alumina, 

sodium silicate, and sodium carbonate solution were heated together 

under pressure; and also by the action of sodium carbonate, fused in 

its water of crystallization, upon elaeolite. 3 Labradorite, heated to 

215° with sodium carbonate solution, also gave him cancrinite,4 C. 

and G. Friedel 5 prepared a hydrous cancrinite by heating muscovite 

to 500° in a solution of sodium carbonate and caustic soda. With 

sodium sulphate in place of the carbonate, a hydrous noselite was 

formed. 6 The same authors obtained sodalite by treating muscovite 

at 500° with sodium chloride and caustic, soda.7 Lemberg 8 produced 

sodalite by fusing nephelite with common salt; and the fusion of 

elseolite or sodalite with sodium sulphate gave noselite.9 In short, 

the experiments of Lemberg, which were very numerous, proved 

that compounds of this class could be derived, by simple reactions, 

from nephelite, and that they are mutually convertible, one into 

another. Furthermore, S. J. Thugutt 10 prepared sodalite by heating 

natrolite with soda solution and aluminum chloride to 195° under 

pressure; and also from similar treatment of kaolin with common 

salt and caustic soda at about 212°.n Sodalite, then, has been 

derived by artificial means from elseolite, muscovite, and kaolin. 

It was also obtained by Z. Weyberg 12 when a mixture of silica, 

alumina, and soda was fused with a large excess of common salt.

In his work upon artificial magmas, J. Morozewicz 13 prepared 

noselite, hauynite, and sodalite by purely pyrochemical methods, 

equivalent to those which produce these minerals in volcanic rocks. 

The fusions were effected at temperatures not exceeding 600° to 

700°, for compounds of this class are decomposed by an excessive 

heat. From a mixture of kaolin, sodium carbonate, and sodium 

sulphate, noselite crystals were formed. From a more complex 

mixture, containing also calcium silicate, potassium silicate, iron 

silicate, calcium carbonate, and calcium sulphate, hauynite was 

produced. Kaolin fused with sodium carbonate and sodium chloride

1 A "chromate sodalite," containing Na2CrO4, has lately been describedbyZ. Weyberg, Ceutralbl. Min. 

Geol. u. Pal., 1904, p. 727. It differs from the hydrated compound prepared by Thugutt.

2 Zeitschr. Deutsch. geol. Gesell., vol. 35,1883, p. 593. 

a Idem, vol. 37,1887, p. 963.

< Idem, vol. 39,1887, p. 559. For a recent discussion of the constitution of cancrinite see Thugutt, Neues 

Jahrb., 1911, Band 1, p. 25.

< Bull. Soc.,min. vol. 14,1891, p. 71.

«Idem, vol. 13,1890, p. 238.

' Compt. Rend., vol. 110,1890, p. 1170.

s Zeitschr. Deutsch. geol. Gesell., vol. 28,1876, p. 602.

9 Idem, vol. 35,1883, p. 590.

10 Neues Jahrb., Beil. Band 9,1894-95, p. 576. 

u Mineralchemische Studien,p. 18. 

12 Centralbl. Min., Geol. u. Pal., 1905, p. 717. 

is Min. pet. Mitt., vol. 18,1898, pp. 128-147.
ROCK-FORMING MINERALS. 371

~> gave a compound having the formula already assigned to socialite; 

elseolite, similarly treated, yielded a substance richer in chlorine. 

Morozewicz concludes that two kinds of sodalite exist; to one he

*4. gives the formula 2(Na2Al2Si208 )-f NaCl, while the other agrees with 

3(Na2Al2Si208 ) + 2NaCl. 

Cancrinite occurs only in elseolite syenite and allied rocks, closely

* associated with nephelite and sodalite. W. Ramsay and E. T. 

Nyholm * have described a cancrinite syenite in which cancrinite is 

an important primary mineral. Cancrinite alters into a zeolitic

> substance, "spreustein," in which natrolite is the predominating 

mineral. 2 . Crystallized sodalite is also found in trachyte and phonolites, in which it separates after augite. 3 Sodalite alters into hydro-

» nephelite and natrolite. Haiiynite and noselite form in various 

leucitic and nephilinic rocks among the younger eruptives. In order 

of deposition they are the oldest of the feldspathoids.

*" THE PYROXENES.

Enstatite. Orthorhombic. Composition, MgSi03 , but generally 

«» with admixtures of FeSi03 . When 10 to 12v per cent of the latter 

salt is present the mineral is known as bronzite. Minimum molecular weight, 100.8. Specific gravity, 3.1. Molecular volume, 32.5. 

Color ranging from white to olive green and brown. Hardness, 5.5. 

HyperstTiene. Orthorhombic. Composition like enstatite, but 

^ with FeSi03 predominating. The molecular weight of the latter

*, compound is 132.3. Color, greenish and brownish to black. Specific

gravity, 3.4 to 3.5. Hardness, 5 to 6.

~* Enstatite and hypersthene, the Orthorhombic members of the 

pyroxene group, are to be regarded as mixtures of the two isomorphous salts MgSiQs and FeSi03 . Hypersthene is also modified in 

many cases by the presence of a third salt, CaSi03 , but in very 

subordinate quantities. The enstatite of the Bishopville meteorite 

consists of the magnesian silicate very nearly pure. The formulae 

given above are minima, the actual formulae being multiples of them, 

at least double, possibly more.

The first synthesis of supposed enstatite was made by J. J. Ebelmen, 4 who fused silica, magnesia, and boric oxide together. 

A. .Daubre"e 5 obtained it repeatedly in his attempts to reproduce the 

characteristics of meteorites, when meteoric stones and magnesian 

eruptive rocks were fused. "Enstatite" recrystallized on cooling

1 Bull. Comm. geol. Finland, vol. 1,1895, No. 1. See also I. G. Sundell, idem, 1905, No. 10.

2 See W. C. Brogger, Zeitschr. Kryst. Min., vol. 1C, 1890, p. 240; also L. Saemaim and P. Pisani, Anrialcs

* chim. phys., 3d ser., vol. 67,1863, p. 350.

8 On sodalite syenite from Square Butte. Montana.see W. Lindgren, Am. Jour. Sci., 3d ser., vol. 45, 1893, 

p. 286. A sodalite trachyte from Tcneriffle has been described by H. Preiswerk, Centralbl. Min., Geol. u. 

Pal., 1909, p. 393.

J, « Anuales chim. pays., 3d ser., vol. 33,1851, p. 58. 

6 Compt. Rend., vol. 02,1SCO, pp. 200, 369, 060.
372 DATA OF GEOCHEMISTRY.

the melts. He also prepared the same substance by fusing olivine 

with silica, and he found that when serpentine was melted it broke 

clown into a mixture of enstatite and olivine. The latter reaction 

has been verified quantitatively in the. laboratory of the United 

States Geological Survey. P. Hautefeuille * produced a silicate 

which he identified with enstatite, by dissolving amorphous silica in 

molten magnesium chloride, and S. Meunier 2 effected its synthesis 

by acting on metallic magnesium with silicon chloride and water 

vapor.

Later investigations, however, by F. Fouque and A. Michel 

Levy, 3 and also by J. H. L. Vogt, 4 have shown that the foregoing 

syntheses were misinterpreted. The product obtained was in most 

cases, if not in all, a monoclinic magnesium metasilicate, instead of 

the orthorhombic enstatite. The latter form was obtained by 

Fouque and Levy 5 by simply fusing silica, magnesia, and ferric 

oxide together, but it was more or less mixed with the monoclinic 

variety.

In the elaborate research by E. T. Alien, F. E. Wright, and J. K. 

Clement,6 it has been found that magnesium metasilicate exists in 

four modifications, two being pyroxenes and two amphiboles. The 

monoclinic pyroxene is formed whenever a melt having its composition is allowed to crystallize at temperatures a little below 1,521°. 

It can be crystallized at lower temperatures from solution in molten 

calcium vanadate, magnesium vanadate, or magnesium tellurite. 

The other three modifications of the silicate pass into this variety 

when heated to about 1,000° in molten magnesium chloride traversed by a stream of dry hydrochloric acid gas. The monoclinic 

pyroxene, then, is the most stable form of magnesium metasilicate. 

According to N. L. Bowen and 0. Andersen,7 it has no true melting 

point but breaks down at 1,557° into forsterite and silica.

When a glass having the composition of enstatite is devitrified by 

heating to a temperature above 1,000° and below 1,100°, best at 

about 1,075°, the orthorhombic enstatite is formed. In this way 

good crystals were produced. At slightly higher temperatures the 

monoclinic pyroxene begins to appear. The presence of enstatite 

in an igneous rock is evidence that the final crystallization took place 

at the relatively lower temperatures, for above them it can not exist. 

What the effect of iron may be in modifying the properties of these 

silicates is as yet undetermined.

1 Annales chim. phys., 4th ser., vol. 4,1865, p. 374.

2 Compt. Rend., vol. 90,18SO, p. 349; vol. 93,1SS1, p. 737.

3 Synthese des mineraux et des roches, 1882. 

« Mineralbildung in Schmelzmassen, 1S92, p. 71. 

& Loc. cit.

6 Am. Jour. Sci., 4th ser., vol. 22,1906, p. 3S5. 

' Idem, vol. 37,1914, p. 487.
ROCK-FORMING MINERALS. 373

Enstatite and hypersthene are common pyrogenic minerals, and 

occur in many eruptive rocks. Enstatite and bronzite are often constituents of meteorites. According to J. Morozewicz 1 the orthorhombic pyroxenes separate from metasilicate magmas when the 

ratio Mg -f Fe : Ca is 3 : 1 or greater. Both species undergo alteration, through hydration, into talc 2 and serpentine. Bastite is an 

alteration product of this kind, having the composition of serpentine.

Wollaslonite. Monoclinic. Composition, CaSi03 . Minimum molecular weight, 116.5. Specific gravity, 2.85. Molecular volume, 

40.5. Color, Avhite, often tinted by impurity. Hardness, 4.5 to 5.

Calcium metasilicate is known in two modifications the natural 

wollastonite and an artificial pseudohexagonal form. The latter is 

easily produced by fusing lime and silica together a and has been 

repeatedly observed in slags.4 Wollastonite has also been found in 

slags, but rarely.5 E. Hussak,0 however, by fusing and slowly cooling a glass containing silica, soda, lime, and boric acid, obtained 

crystals of wollastonite. C. Doelter 7 also effected the synthesis of 

wollastonite by fusing calcium metasilicate with sodium fluoride.

According to E. T. Alien and W. P. White,8 wollastonite is stable 

only below 1,190°, and above that temperature it passes into the 

pseudohexagonal modification. By heating a glass of the composition CaSi03 to between 800° and 1,000°, pure wollastonite was 

obtained. The reverse change, from the pseudo variety to the 

normal, was brought about by dissolving the former in molten calcium vanadate and crystallizing at a temperature between 800° and 

900°. The melting point of the silicate is 1,540°.

The pseudowollastonite has not yet been observed as a natural 

mineral, but wollastonite is common. The inference from this fact, 

as drawn by G. F. Becker,9 is that the rocks containing free calcium 

metasilicate must have crystallized at temperatures below the inversion point of wollastonite, for otherwise its isomer would have 

appeared.

Although wollastonite is usually classed with the pyroxenes, its 

place among them is doubtful. It differs from them in being easily 

decomposed by acids, and its occurrences in nature are not the same. 

It is very rare in eruptive rocks, and is commonly found as a product

' Mill. pot. Mitt., vol. IS, 1898, p. 110.

2 See C. H. Smyth, School of Minos Quart., vol. 17, 1S9G, p. 333.

s gce L. Bourgeois, Bull. Soc. min., vol. 5, 18S2, p. 13; A. Gorgeu, idem, vol. 10,1887, p. 273; and C. Doelter, Neues Jahrb., 1880, Band 1, p. 119.

« See J. H. L. Vogt, Mineralbildungin Schmelzmassen, 1892, pp. 34-80.

< See Vogt, loc. cit, and P. Heberdey, Zeitschr. Kryst. Min., vol. 26, 1896, p. 22.

« Zeitschr. Kryst. Min., vol. 17, 1890, p. 101.

' Min. pet. Mitt., vol. 10, 1888, p. 83. For later work by Poolter, see Sitzimgsb. K. Akad. Wiss. Vien, 

vol. 120, Abth. 1, p. 339, 1911.

s Am. Jour. Sci., 4th ser., vol. 21, 1906, p. 89. See also A. L. Day, E. S. Shepherd, and F. E. Y/right, 

idem, vol. 22, p. 2C5. The synthetic wollastonite reported by L. v. S/athmary (Foklt. Kozl., vol. 39,1909, 

p. 314) was the pseudomincral. See B. Mauritz, idem, p. 505.

° Prefatory note to the memoir by Alien and White.
374 DATA OF GEOCHEMISTRY.

of contact metamorphism, especially in limestones. ,It occurs also in 

feldspathic schists. H. Wulf 1 has described a rock from Hereroland, 

Africa, which consisted of wollastonite and diopside in nearly equal 

proportions. An occurrence of wollastonite in aplite is recorded 

by A. Lacroix.2 The alteration of wollastonite to ordinary pyroxene 

is reported by C. H. Smyth,3 and an alteration to apophyllite by 

S. J, Thugutt.4 The secondary mineral pectolite, HNaCa2 Si3 09 , is 

regarded as a derivative of wollastonite.

Diopside. Monoclinic. Composition, CaMgSi2O6 . Molecular weight, 

217.3. Specific gravity, 3.2. Molecular volume, 68. Color, white, 

yellowish, green, and nearly black. Hardness, 5 to 6. Chrome diopside is a variety containing small amounts of chromium.

Hederibergite. Monoclinic. Composition, CaFeSi206 . Molecular 

weight, 248.8. Specific gravity, 3.5 to 3.6. Molecular volume, 70. 

Color, grayish green to black. Hardness, 5 to 6.

Between diopside and hedenbergite there are various intermediate 

mixtures. Schefferite is another monoclinic pyroxene containing 

manganese, up to over 8 per cent of MnO. Jeffersonite is another 

member of this group containing zinc. These variations may represent mixtures of the simple salts MnSiO3 and ZnSiO3 with the lime, 

magnesia, and iron silicates; but the commingled salts are probably 

more complex. Rhodonite, MnSi03 , is classed also as a pyroxene, 

but is triclinic. It can hardly beo considered as a rock-forming 

mineral, at least not in the usual acceptance of the term.

Monoclinic pyroxenes of the diopside-hedenbergite type have been 

repeatedly observed in slags.5 A. Daubree, 0 on heating water to 

incipient redness in a glass tube, obtained crystals of diopside. G. 

Lechartier 7 effected the synthesis of these pyroxenes by fusing silica, 

lime, and magnesia with an excess of calcium chloride. When ferric 

oxide was added to the mixture, iron pyroxenes were formed. In 

the experiments of J. Morozewicz 8 with artificial magmas these minerals were deposited when the ratio Mg + Fe: Ca was less than 3:1. 

Clear and perfect crystals of diopside have been prepared by E. T. 

Alien and W. P. White, 9 who heated glass of the theoretical composition in a flux of calcium chloride and an atmosphere of hydrochloric 

acid to 1,000° for several weeks. The specific gravity of the artificial

1 Min. pet. Mitt., vol. 8,1887, p. 230.

2 Bull. Soc. JUin., vol. 21, p. 272, 1898.

a Am. Jour. Sci., 4th ser., vol. 4,1897, p. 309.

< Centralbl. Min., Geol. u. Pal., 1911, p. 764.

6 See citations in L. Bourgeois, Reproduction artificielle des min£raux,pp. 115-116; and Fouque" and 

Levy, Synthese des min6raux et des roches, pp. 102-103. Also G. J. Brush, Am. Jour. Sci., 2d ser., vol. 

89,1865, p. 131.

 Etudes synthStiques de geologic expe"rimentale, pp. 159-176.

' Compt. Rend., vol. 67,1868, p. 41. Compare A. Gorgeu, Bull. Soc. min., vol. 10,1887, pp. 273,276.

8 Min. pet. Mitt., vol. 18,1898, pp. 123 et seq. See also J. H. L. Vogt, Die Silikatschmelzlosungen, pt. 

1,1903, pp. 28-49.

9 Am. Jour. Sci.,4thser., vol.27,1909, p. 1.
BOCK-FORMIXG MINERALS. * 375

mineral was 3.275 and the melting point ],3SO°. They found that 

diopside is the only stable compound between its component silicates, 

although two eutectics were observed.

The monoclinic pyroxenes are common in eruptive rocks and the 

crystalline schists. The variety known as di all age is especially 

characteristic of gabbro. They also occur as secondary minerals. 

R. Brauns 1 has observed the variety salite, as formed in a picrite by 

the action of aqueous solutions upon, olivine and plagioclase.

Acmite or s&girite. Monoclinic. Normally NaFe'"Si200 , but often 

containing ferrous and lime silicates in isomorphous admixture. 

Molecular weight, 231.7. Specific gravity, 3.53. Molecular volume, 

65.6. Color, brownish, greenish, to black. Hardness, 6 to 6.5.

Jadeite. Monoclinic. Composition, NaAlSi20G . Molecular weight, 

202.9. Specific gravity, 3.34. Molecular volume, 60.8. Color, white 

and various shades of green. Hardness, 6.5 to 7.

Spodumene. Monoclinic. Composition, LiAlSi2Oe . Molecular 

weight, 186.9. Specific gravity, 3.17. Molecular volume, 58.9. 

Color, white, yellow, green, and amethystine. Hardness, 6.5 to 7. 

Hiddenite is the emerald-green gem spodumene from North Carolina. 

Kunzite is the amethystine gem variety from California.

These alkali pyroxenes, as they are often called, are interesting on 

account of their constitutional similarity. Acmite, however, is the 

most important as a rock-forming mineral, although in the interpretation of mixed pyroxenes the jadeite molecule must often be 

taken into account. Spodumene occurs only sporadically usually, 

if not always, in pegmatite and is peculiarly noticeable on account 

of the immense size which its crystals may attain. Crystalline faces 

of spodumene many feet in length have been observed in the Black 

Hills of South Dakota. The alteration of spodumene, as studied by 

A. A. Julien, 2 and more exhaustively by G. J. Brush and E. S. Dana, 3 

is very instructive. First, by the action of percolating solutions containing soda, it is transformed into a mixture of'eucryptite, LiAlSi04 , 

and albite, NaAlSi308 . Then, by the further action of potassium 

salts, the eucryptite is altered into muscovite, KH2Al3Si3012 . Albite 

and muscovite are the final products of these metamorphoses. The 

intimate mixture of these two compounds was long thought to be a 

distinct mineral, cymatolite.

Acmite can be produced synthetically, but its constituent oxides, 

when fused together, commonly yield only a glass containing crystals 

of magnetite. Acmite, when fused, resolidifies as a mixture of magnetite and glass. 4 C. Doelter, 5 however, from the fusion of an arti1 Neues Jahrb., 1898, Band 2, p. 79.

2 Annals New York Acad. Sci., vol. 1,1879, p. 318. 

s Am. Jour. Sci.,3d ser., vol.20,1880, p. 257. 

« M. Vucnik, Centralbl. Min., Geol. u. Pal., 1904, p. 309. 

»Neues Jahrb., 1897, Band 1, p. 16.
376 DATA- OF GEOCHEMISTRY.

ficiai mixture of the oxides, obtained some acmite. H. Backstroin l 

fused silica, ferric oxide, and sodium carbonate, mingled in the 

proper proportions, together and held the solidified mixture at a dull 

red heat for three days. Under those conditions acmite was formed. 

He also obtained it by fusing a leucite phonolite and subjecting the 

glass to a similar, very slow devitrification. Z. Weyberg 2 also obtained acmite by fusing a mixture of the composition 2Si02 -f Fe203 + 

Na2O with a large excess of sodium chloride. According to J. Morozewicz, 3 the acmite-jadeite compounds form in metasilicate magmas 

when the silica amounts to less than 50 per cent. The exact conditions of their generation, however, with respect to temperature and 

rate of cooling, are yet to be determined.

Several attempts have been made toward the synthesis of spodumene. By fusing together lithium carbonate, alumina and silica R. 

Ballo and E. Dittler 4 obtained several silicates, one having the composition of spodumene, and another that of eucryptite. The artificial 

spodumene, however, differs from the natural mineral in its optical 

properties, and is designated /3 spodumene. The natural, a mineral 

is transformed at about 1,000° into the other, which melts at 1,380°. 

Similar results have since been obtained by F. M. Jaeger and A. Simek,5 

who found the transition temperature from a to /3 spodumene to be 

995°, and the melting point 1,417°. Natural kunzite fused at 1,428°, 

and the artificial orthosilicate, " pseudoeucryptite" at 1,388°.

Acmite is a mineral of eruptive rocks, generally of those which 

contain leucite or nephelite. It is especially common in elaeolite 

syenite. Concerning the petrologic relations of jadeite less is known; 

but S. Franchi e has identified the mineral as an essential constituent 

of certain eruptive rocks in Piedmont. Acmite or segirite, according 

to W. C. Brogger,7 alters into analcite. J. Lemberg,8 by heating 

spodumene or jadeite with alkaline solutions under pressure, also 

obtained analcite. Jadeite alone is slowly attacked, but the glass 

resulting from its fusion is altered readily. It is noticeable that 

jadeite and dehydrated analcite have the same empirical composition; 

but the denser jadeite molecule is doubtless the more complex. 

The one is a polymer of the other. These alterations, natural or 

artificial, emphasize the constitutional similarity of the three alkali 

pyroxenes.

1 Bull. Soc. min., vol. 16,1893, p. 130.

2 Centralbl. Min., Geol. u. Pal., 1905, p. 717.

3 Min. pet. Mitt., vol. 18,1S98, p. 123.

«Zeitschr. anorg. Chemie, vol. 76,1912, p. 39.

8 Abst.in Chem. Zentralbl., 1914, ii, pp. 1026,1027. See also K. Endell and R. Eieke, Zeitschr. anorg. 

Chemie, vol. 74, 1912, p. 33; who give 950° as the melting point of natural spodumene. For an earlier 

research on the lithium-aluminum silicates see P. Hautefeuille, Compt. Rend., vol.90,1880, p. 541.

6 Rendiconti R. accad. Lincei, vol. 9, pt. 1,1900, p. 349. On the jadeite of Upper Burma,see A. W. G. 

Bleeck, Zeitschr. prakt. Geologie, 1907, p. 341.

' Zeitschr. Kryst. Min., vol. 16,1890, p. 333. Brogger cites many references to theliterature of acmite.

8 Zeitschr. Deutsch. geol. Gesell., vol. 39,1SS7, p. 584.
ROCK-FORMING MINERALS. 377

Auyite. Monoclinic. Composition very variable, for augite is an 

isomorphous mixture of several different silicates. Specific gravity, 

2.93 to 3.49. Color, white, green, brown, and black. Hardness, 5 

to 6.

Augite is essentially a metasilicate of lime, magnesia, and ferrous 

iron, plus silicates of ferric iron and alumina. Manganese and 

alkalies are often present, and some varieties contain titanic oxido 

up to 4.5 per cent. In addition to silicate molecules analogous to 

those of the pyroxenes already described, augite is supposed to contain a compound of the form R/'Al2Si06 , which, however, is hypothetical. The rare mineral kornerupine or prismatine, however, has 

the formula MgAlaSi06 , and may represent the aluminous constituent of the nonalkaline augites. 1 When alkalies are present they 

probably represent molecules analogous to or identical with acmite 

and jadeite.

The following analyses of rock-forming augite 2 were all made in 

the laboratory of the United States Geological Survey:

Analyse* of any its..

A. From nepheliue basalt, Black Mountain, Uvalde quadrangle, Texas. W. F. Hillebrand, analyst.

B. From dolerite, near Valmont, Colorado. Analyzed by L. G. Eakins.

C. From tingnaite, Two Buttcs, Colorado. Analyzed by Hillebrancl.

D. From granite, Silver Cliff, Colorado. Eakins, analyst.

K. From a dyke, Silver Cliff. Eakins, analyst.

F. From basalt, Mount Taylor region, New Mexico. Analyzed by T. M. Chatard.

Si02 ............. ........... -

Ti02 . -- ......................

A1 203 ............. ...........

Ora08 .. .......................

Fe20a ... .....................

Fe5 ---

MnO.. .......................

MgO.........................

f\»O

Xa20 ........................

K20.. ........................

NiO.. .......................

P O

H20............ ..............

A

45.23

4.28

7.73

2.95

4.07

.07

12.25

23. 37

.47

.12

.05

None.

.37

]00. 96

B

40. 10

7.95

8.30

12. 37

99 <U

Trace.

100. 26

C

47. 54

3.00

4.14

5.64

fi 49

.36

10.05

9"! ^7

1.38

.12

Trace.

100. 22

D

48. 72

9.27

3.77

6.34

Q4

14. 67

16.79

IQ

 I Q

100. 27

E

54. 87

6. 34

«) CO

4. 61.

. :i4

14. 47

 | c 07

.28

. 3.1.

99. 77

F

47. 06 i 09

7.77

Trace.

I Oft

o ir.

90

 | q ro

I') 'W

.33

.11

TVopn

.06

9ft

99.85

Augite is a common mineral in slags,3 and is easily produced from 

its constituents by simple fusion.4 It was repeatedly obtained by 

Fouque" and Levy,5 both by itself and in association with other min-

» A more complex formula, NaHsMgoAl^SiTO , has been assigned to kornerupine by J. Uhlig, Zeitschr. 

Kryst. Min., vol. 47, 1910, p. 215.

2 From Bull. U. S. Geol. Survey No. 419, 1910, pp. 202, 2C3. 

a See J. H. L. Vogt, Mineralbildung in Schmelzmassen, p. 34.

« For early syntheses, see Fouqu6 and L<5vy, Synthose des minfiraux el; des roches, p. 102. 

6 Op. cit., pp. CO, 07, 105.
378 DATA' OF GEOCHEMISTRY.

erals, in their classic experiments upon the synthesis of rocks. J. 

Morozewicz 1 also has found both ordinary augite and the alkaline 

varieties in the products yielded by his artificial magmas. The molecule RAl2Si06 is generally formed from magmas containing over 50 

per cent of silica; and its alumina appears to be the residue left over 

after the feldspars, feldspathoids, and micas have been satisfied.

When garnet, vesuvianite, or epidote is fused augitic minerals 

appear among the compounds produced. 2 Biotite and clinochlore 

also yield it among the products of their thermal decomposition.3 

C. Doelter 4 found that augite was formed when diopside was fused 

with alumina or ferric oxide; and from mixtures of silica with the 

proper bases he obtained crystals rich in RALSiO6 . According to 

J. Lenarcic,5 magnetite and labradorite, fused together, yield augite. 

So, too, does hedenbergite when fused with anorthite, albite,6 or 

corundum. 7

Several other minerals in addition to those already named are 

classed as pyroxenes, but they are too rare to need more than a passing mention here. The so-called zircon pyroxenes, rosenbuschite, 

lavenite, wohlerite, and hiortdahlite are found in the elseolite syenites 

of Norway. The triclinic babingtonite is interesting, for it contains, 

in addition to the molecular types found in the other pyroxenes, the 

ferric silicate Fe 2Si 3O9 . It has been found not only as a natural 

mineral, but also as a furnace product in slag. 8

Augite, among the pyrogenic minerals, is to be classed as one of 

the older secretions. It is common in igneous rocks of nearly all 

classes, and the pyroxenes in general are the most important of the 

so-called ferromagnesian minerals. Some rocks, the pyroxenites, consist of pyroxenes almost entirely; websterite, for instance, is formed 

of bronzite and diopside. The most striking alteration of pyroxene 

is into hornblende, but it also alters into tremolite, 9 chlorite, serpentine, talc, mica, garnet, epidote, and glauconite. The pyroxenes, 

furthermore, occur as important secondary minerals, sometimes as 

the product of contact metamorphism in limestones, sometimes as 

marginal zones derived from olivine. 10 Diallage and hypersthene 

rocks alter into amphibolites. 11

 :_____________________________________________________________________________________.

> Min. pet. Mitt., vol. 18,1898, pp. 107,113,120,123,124.

2 C. Doelter, Allgemeine chemische Mineralogie, pp. 182,183.

3 Doelter, Neues Jahrb., 1897, Band 1, p. 1. 

* Idem, 1884, Band 2, p. 51. 

5 Centralbl. Min., Geol. u. Pal., 1903, pp. 705,743. 

e M. Vu6nDc, Centralbl. Min., Geol. u. Pal., 1904, pp. 300,342. 

7 B. Vukits, idem, 1904, p. 705.

s See L. Buchrucker, Zeitschr. Kryst. Min., vol. 18,1891, p. 626.

s See H. Ries, Annals New York Acad. Sci., vol. 9, 1896-97, p. 124, in an important memoir upon Hie 

pyroxenes of New York.

10 See G. H. Williams, Am. Jour. Sci., 3d ser., vol. 31,1886, p. 35, and F. D. Adams, Am. Naturalist, vol. 

19, 1SS5, p. 1087. Williams gives a number of references to alterations of this kind.

11 Williams, Am. Jour. Sci., 3d ser., vol. 28,1884, p. 258.
,a

ROCK-FORMING MINERALS. 379

NOTE. For theoretical discussions upon the constitution of the pyroxenes see G. 

Tschcrmak, Jahrb. K.-k. geol. Reichsanstalt, vol. 21, 1871, Min. pet. Mitt., p. 17* 

C. Doelter, Min. pet. Mitt., vol. 2, 1879, p. 193. F. W. Clarke, Bull. U. S. Geol. 

Survey No. 588, 1914. J. W. Retgers, Zeitschr. physikal. Chemie, vol. 16, 1895, 

p. 614. P. Mann, Neues Jahrb., 1884, Band 2, p. 172. A. Merian, idem, Beil. Band 3, 

1884, p. 252. The literature upon this subject is very voluminous.

THE AMPHIBOLES.

Anthophyllite. Ofthorhombic. Composition like enstatite or 

bronzite (Mg,Fe)Si0 3, with the magnesium silicate predominating. 

Specific gravity, 3 to 3.2. Color, gray, brown, green,/ and intermodiate shades. Hardness, 5.5 to 6. Gedrite is a variety containing usually more iron and much alumina. As an amphibole, anthophyllite 

corresponds to hypersthene among the pyroxenes. 1

Tremolite. Monoclinic. Composition, CaMg3Si 4O12 . Molecular 

weight, 370.1. Specific gravity, 2.9 to 3.1. Molecular volume, 123. 

Color, white to gray. Hardness, 5 to 6.

Actinolite. Like tremolite, but with iron partly replacing magnesium. Specific gravity, 3 to 3.2. Nephrite is a compact variety of 

actinolite. True asbestos is a fibrous form of tremolite or actinolite; 

but anthophyllite and crocidolite are also found asbestiform. The 

Canadian asbestos of commerce is serpentine. 2

Cummingtonite. Monoclinic, but with the composition of an 

anthophyllite containing much iron. Specific gravity, 3.1 to 3.3. 

Color, gray to brown.

The foregoing members of the amphibole group, except the aluminous gedrite, are most simply interpreted, like the corresponding 

pyroxenes, as mixtures of metasilicates of calcium, magnesium, and 

iron. Grunerite is the ferrous silicate, FeSi03 , alone. 3 Dannemorite 

is a similar iron-manganese metasilicate. In richterite, which has a 

similar general formula, alkalies appear, up to 9 per cent or more. 

Many analyses of these minerals show the presence of water in them, 

and also of fluorine.

Anthophyllite and gedrite are essentially Archean minerals, occurring especially in hornblende gneisses and schists. Tremolite is found 

as an accessory mineral in metamorphic limestones and dolomites. 

Actinolite is also a mineral of the metamorphic rocks. In the 

iron regions near Lake Superior actinolite-magnetite schists are 

common. 4

1 An iron anthophyllite, FeSiOs, associated with the fayalite of Rockport, Massachusetts, has been 

described by C. H. Warren, Am. Jour. Sci., 4th ser., vol. 10, 1903, p. 337.

2 See G. P. Merrill, Proc. U. S. Nat. Mus., vol. 18, 189G, p. 291, for a good summary 'of our knowledge of 

asbestos.

8 A. C. Lane and F. F. Sharpless (Am. Jour. Sci., 3d scr., vol. 42, 1891, p. 505) have applied the. name 

griincrite to a ferromagncsian amphibole like cummingtonite.

4 See W. S. Bayley, Am. Jour. Sci., 3d ser., vol. 46, 1893, p. 170. Also C. R. Van Hise, C. K. Leith, and 

others, in Mon. U. S. Geol. Survey, vol. 28, 1897; vol. 43, 1903.
380 DATA OF GEOCHEMISTRY.

Anthophyllite, tremolite, and actinolite alter easily into talc, serpentine, and calcite. The reverse alteration, of talc into anthophyllite, has been reported by Genth. 1 Uralite, which has ordinarily the 

composition of actinolite, is an amphibole derived by alteration from 

similarly constituted pyroxenes.2

Hornblende. Monoclinic. Composition variable, as with augite, 

of which hornblende is the equivalent among the amphiboles. Hornblende, however, contains a smaller proportion of lime and more 

magnesia plus iron than augite. It also contains aluminous silicates. 

The light-colored hornblende, with little iron, is called edenite. The 

darker varieties are known as pargasite. Specific gravity, 3.0 to 3.47, 

depending upon the proportion of iron. Color, white, gray, green, 

and brown, ranging to black. Hardness, 5 to 6.

The subjoined analyses of hornblende are given in the memoir by 

S. L. Penfield and F. C. Stanley. 3 They show the variability in composition of the mineral, and also the predominance of magnesium and 

iron over calcium, the reverse condition from that noted in augite.

Analyses of hornblende.

A. From Renfrew, Ontario. Stanley, analyst. 

B. From Edenville, New York. Stanley, analyst.

C. From Cornwall, New York. J. L. Nelson, analyst. Am. Jour. Sci., 4th ser., vol. 15,1903, p. 227. 

Fluorine determination added to Nelson's analysis by Stanley. 

D. From Monte Somma, Italy. Stanley, analyst. 

E. Basaltic hornblende, Bilin, Bohemia. Stanley, analyst. 

F. From Grenville Township, Quebec. Stanley, analyst.

SiOo................... .......

Tiff

AUV ...................... .

Fe"203 .. .......................

Feb..........................

MnO. ........................

MgO.. .......................

CaO.........................

K,0..........................

XsL*Q. .......................

B&......... .................

F.".. ..........................

Loss at 110°..................

0=F.. ....................

*

A

43. 76

.78

8.33

6.90

10.47

.50

12.63

9.84

1.28

3.43

.65

1.82

..10

100. 49 

.76

99. 73

B

41.99

1.46

11.62

2.67

14.32

.25

11 17

11.52

.98

2.49

.61

.80

.08

99.96 

.33

99.63

C

36.86

1.04

12.10

7.41

23.35

.77

1.90

10.59

3.20

1.20

1.30

.27

99.99 

.11

99.88

D

39.48

.30

12.99

7.25

10.73

1.00

11. 47

12.01

2.39

1.70

.76

.05

.12

100. 25 

.02

100. 23

E

39.95

1.68

17.58

7.25

2.18

Trace.

 14.15

11.96

1.98

3.16

.41

.03

.13

100. 46 

.01

100. 45

F

45.79

1.20

11.37

4?

40

.39

91 11

19 71

1 fiQ

2.51

.67

9 7fi

101. 04 

1.16

99.88

The synthesis of hornblende was first effected by K. Chrustschoff. 4 

He heated a solution containing dialyzed silica, alumina, and ferric

> Proc. Am. Philos. Soc., vol. 20,18S2, p. 393.

2 On the theory of nralitization see L. Duparc and T. Hornung, Compt. Rend., vol. 139, 1904, p. 223. 

See also Duparc, Bull. Soc. min., vol. 31, 1908, p. 50.

3 Am. Jour. Sci., 4th ser., vol. 23, 1907, p. 23. ' * 

* Compt. Rend., vol. 112,1891, p. 077.
ROCK-FORMING MINERALS. 381

hydroxide with some ferrous hydroxide, magnesium hydroxide, and 

limewater for three months to 550° in a closed digester and obtained 

crystals of amphibole. C. Doelter, 1 by using fluxes of low melting 

point, also succeeded in producing the mineral. A mixture of magnesia, oxide of iron, alumina, and silica, fused with boric acid, gave 

the desired result. He also succeeded in recrystallizing amphiboles 

from a flux of borax or from one of magnesium chloride and calcium 

chloride; but in most of his experiments augite, sometimes with 

olivine, scapolite, magnetite, anorthite, or orthoclase, was produced. 

E. T. Alien, F. E. Wright, and J. K. Clement, 2 in the research already 

cited under pyroxene, found that when magnesium metasilicate was 

heated considerably above its melting point and then rapidly cooled 

the orthorhombic amphibole was formed. With slow cooling pyroxenes are produced. By heating the orthorhombic amphibole with 

water at 375° to 475° it was transformed into the monoclinic modification. The latter was also obtained when solutions of magnesium 

ammonium chloride or of magnesium chloride and sodium bicarbonate were heated with sodium silicate or amorphous silica during 

three to six days at 375° to 475° in a steel bomb. Small quantities 

of quartz and of forsterite were formed at the same time.

According to A. Becker, 3 when anthophyllite or hornblende is 

fused, a pyroxene, sometimes with olivine, is formed. According to 

A. Lacroix, 4 alterations, due to heat alone or to the action of molten 

magmas, of hornblende to augite, are common among the volcanic 

rocks of Auvergne. The amphiboles, in short, are unstable at high 

temperatures, and either the rapid cooling of a magma, the presence 

of water, or some undetermined influences of pressure, conditions 

their appearance as pyrogenic minerals. An excess of magnesia is 

also favorable to their development, while an excess of lime may 

determine the formation of pyroxene.

Common hornblende is very widely diffused, as in granite, syenite, 

diorite, diabase, gabbro, and norite, and in the metamorphic gneisses, 

hornblende schists, and amphibolites. The crystallized "basaltic 

hornblende" appears as an early secretion in andesite, dacite, phonolite, basalt, etc. Hornblende alters not only into pyroxenes, as 

mentioned above, but also into chlorite, epidote, biotite, siderite, 

calcite, and quartz. Pseudomorphs of hornblende or of anthophyllite 

after olivine have been described by F. Becke 5 and B. Kolenko. 6

Ordinarily, the constitution of the hornblendes is supposed to be 

.analogous to that of augite, metasilicates of the form KSi03 being

1 Neues Jahrb., 1897, Band 1, p. 1.

2 Am. Jour. Sci.,4th ser., vol. 22, 1908, p. 385.

»Zeitschr. Detitsch. geol. Gesell., vol. 37, l88-r>, p. 10.

« Minrfralogie de la France, vol. 1,1S93-1895, pp. G6S-669.

B Min. pet. Mitt., vol. 4, 18S2, p. 450.

« Neues Jahrb., Band 2,1885, p. 90.
382 DATA OF GEOCHEMISTRY.

isomorphously commingled with Tschermak 's hypothetical compound 

RAl2Si06 . It is also commonly assumed that the amphibole molecules are larger than those of the pyroxenes, as shown by the formulae 

of diopside, MgCaSi206 , and tremolite, CaMg3Si4012 . The latter 

assumption, however, is not well grounded, for the amphiboles, as a 

rule, are lower in specific gravity than the corresponding pyroxenes, 

which indicates that their molecules are really less condensed. The 

true molecular weights are unknown, and it is quite possible that 

they are better represented by polymeric symbols, such as E8Si8024 

in the pyroxene series and R4Si4012 for the amphiboles. The way 

in which the alkali pyroxenes alter into mixtures of orthosilicates 

and trisilicates offers an argument in favor of this view. In fact, 

G. F. Becker l has sought to explain the relations between the two 

groups of minerals upon the assumption that they are mixtures of 

the two classes of salts just named. There are still other interpretations of the hornblendes. R. Scharizer * regards them as mixtures of 

actinolite with an orthosilicate isomeric with garnet, R/'3R/ //3Si3O1 .! , 

to which he has given the name "syntagmatite." A hornblende 

from Jan Mayen Island agrees very nearly with the supposed syntagmatite in composition. F. Berwerth 3 also assumes the presence 

of orthosilicates in the hornblendes, and attributes part of their 

alumina to molecules which are either those of micas or isomeric with 

them. Another portion of the alumina he regards as forming the 

metasilicate Al2Si3 09 , a compound which is not known to occur by 

itself in nature. An alkali hornblende from Piedmont, described by 

F. R. Van Horn, 4 has very nearly orthosilicate ratios; and so also 

has a variety from Dungannon, Ontario, studied by F. D. Adams and 

B. J. Harrington. 5 Some hornblendes, however, contain a larger 

proportion of oxygen than orthosilicates require; and to explain 

their constitution it is necessary to assume the existence of basic 

salts a condition which is fulfilled by the molecule RAl2Si06 . The 

synthesis of such a compound, or its discovery as an actual mineral 

would go far toward settling the constitution of this important 

group. 6

An interpretation of the amphiboles quite unlike that of Tschermak 

has been proposed by S. L. Penfield and F. C. Stanley. 7 They assume

i Am. Jour. Sci., 3d ser., vol. 38,1889, p. 154. See also F. W. Clarke, Bull. U. S. Geol. Survey No. 588, 

1914.

2 Neues Jahrb., Band 2,1884, p. 143.

3 Sitzungsb. K. Akad. Wiss. Wien, vol. 85, pt. 1,1882, p. 153. See also H. Haefcke, Doct. Diss., Gottingen, 

1890.

< Am. Geologist, vol. 21,1898, p. 370.

5 Am. Jour. Sci., 4th ser., vol. 1,1896, p. 210. " Hastingsite."

« According to C. Doelter and E. Dittler (Sitzungsb. K. Akad. Wiss. Wien, vol. 121, Abth. 1,1912, p. 897)- 

the compound MgAl2SiO6 is unstable in fusion. A compound KAl2SiO6 has been prepared by Z. Weyberg, Centralbl. Min., Geol. u. Pal., 1911, p. 326.

i Am. Jour. Sci., 4th ser., vol. 23,1907, p. 23. Other discussions of the constitution of the amphiboles are 

by S. Kreutz, Sitzungsb. K. Akad. Wiss. Wien, vol. 117, Abth. 1,1908, p. 877, and G. Murgoci, Bull. Dept. 

Geology Univ. California, vol. 4,1906, p. 359.
ROCK-FORMING MINERALS. 383

-w the existence in them of bivalent molecules, A12OF2 , A12 0(OH) 2 , 

A12Q3R", and Al2 04R//Na2 , and also the univalent group MgF, in 

order to account for fluorine, water, and alumina. All of the amphi- 

^ boles are then formulated as polymetasilicates.

All of these interpretations of the amphibole group need careful 

I reconsideration in the light of evidence obtained by E. T. Alien and 

^ J. K. Clement. 1 These chemists find that water is an almost invariable constituent of these minerals, running up in trernolite to as high 

as 2.5 per cent. This water is gradually lost on heating, without any 

^ loss of homogeneity and with very slight change in the optical properties. It is therefore not constitutional but occluded water, or 

water in " solid solution," as the authors express it. W. T. Schaller, 

j^ however, finds that the water of trernolite is essential to the metasilicate ratio, and is therefore more'probably constitutional.

Glaucophane. Monoclinic. Normally NaAlSi2 00 .(FeMg)Si03 , but 

variable amounts of the calcium metasilicate may be present also. 

Color, blue, bluish black, or grayish. Specific gravity, 3 to 3.1. 

Hardness, 6 to 6.5.

^ Riebeckite. Monoclinic. Composition, 2NaFeSi2Oc .FeSi03 . Color, 

black.

Crocidolite. Composition, NaFeSi2 06 .FeSi03 . Resembles riebeckite. Molecular weight, 364.1. Specific gravity, 3.2 to 3.3. Molecular volume, 112. Asbestiform. Color, dark blue, sometimes greenish

- or nearly black. Hardness, 4.

Several other amphiboles related to the three species described 

above have been given independent names. Rhodusite, described by

-^ H. B. Foullon,2 is an asbestiform variety of glaucophane in which 

aluminum has been replaced by ferric iron. Crossite, from California, according to C. Palache, 3 is intermediate between riebeckite

V- and glaucophane. Holmquistite is a glaucophane from Sweden containing over 2 per cent of lithia, described by A. Osann. 4 

Arfvedsonite. Monoclinic. The composition is approximately

-> 4Na2Si03 + 13FeSi03 + 3CaSi06 + Fe''Al,Si00 , but probably variable. 

Specific gravity, 3.45. Color, black. Hardness, 6.

Barkevikite. Intermediate between arfvedsonite and hornblende. 5 

> Color, black. Specific gravity, 3.43.

^Enigmatite. Triclinic. Essentially a metasilicate of sodium and 

' ferrous iron, but with titanium replacing a part of the silicon, and a

i Am. Jour. Sci., 4th ser., vol. 26, 1908, p. 101. Schailer's criticism is as yet unpublished.

! Sitzungsb. K. Akacl. Wiss. Wien, vol. 100, Abth. 1, 1891, p. 176.

a Bull. Dept. Geology Univ. California, vol. 1,1894, p. 181.

< Sitzungsb. Heidelberg Akad., 1913, Abhandl. 23.

> 6 For a discussion of the composition of barkevikite, see W. C. Brogger, Zeitschr. Kryst. Min., vol. 16, 

1890, p. 412. For constitution of these amphiboles see F. W. Clarke, Bull. U. S. Geol. Survey No. 588, 

pp. 102,103.
384 DATA OF GEOCHEMISTRY.

small admixture of the basic salt RFe'^oSiOg. 1 Specific gravitj^, 3.80. 

Color, black.

Among these alkali amphiboles, glaucophane and riebeckite are the 

most important. They are partly, although not absolutely, the equivalent of jadeite and acmite among the pyroxenes, but differ from them 

chemically in containing the molecules FeSi03 , and MgSiO3 in addition to the aluminous compounds. None of them has been prepared 

synthetically, and, like, the other amphiboles, they yield pyroxenes 

upon fusion. 2

Glaucophane occurs chiefly in a series of glaucophane schists and in 

eclogite. 3 It has also been observed in some eruptive rocks. It alters 

into chlorite, feldspar, and hematite. 4 Riebeckite is found in granites and syenites; crocidolite also occurs in granite and in quartz 

schist. By oxidation of the iron and infiltration of silica, crocidolite 

alters into the beautiful ornamental stone known as "tiger-eye." 

Riebeckite is reported as altering to epidote.5

Arfvedsonite and barkevikite occur chiefly in augite and elseolite 

syenites, also in a granite. yEnigmatite is known chiefly from the 

sodalite s}Teiiite of Greenland; but coss}^rite, which is probably the 

Same mineral, was found in a rhyolite lava. Arfvedsonite alters into 

acmite and lepidomelane,6 and so also does barkevikite.7

Kaersutite from Greenland and linosite from the island of Linosa, 

east of Tunis, are aluminous amphiboles rich in titanium. In linosite H. S. Washington 8 found over 10 per cent of Ti02 .

THE OLIVINE GROUP.

Forsterite. Orthorhombic. Composition, Mg2Si04 . Molecular 

weight, 141.4. Specific gravity, 3.2. Molecular volume, 44.2. 

Color, white, often tinted yellowish, greenish, or gray. Hardness, 

6 to 7. Melting point, 1,890°, Bowen.

1 See Brogger, op. cit., pp. 428-429. See also J. Soellner, Neues Jahrb., Beil. Band 24, 1907, p. 475, who 

has described a new mineral, rhoenite, allied to eenigmatite.

2 Sec Brogger, op. cit., p. 410, with reference to arfvedsonite. C. Doelter (Min. pet. Mitt., vol. ]p, 18SS, 

p. 70) fused glaucophane with sodium fluoride and magnesium fluoride and obtained a product resembling 

acmite.

» See K. Oebbeke, Zeitschr. Deutsch. geol. Gesell., vol. 38, 1SS6, p. 634, for a summary of occurrences and 

bibliography. Also H. S. Washington, Am. Jour. Sci., 4th ser., vol. 11, 1901, p. 35; G. F. Beckcr, Mon. 

U. S. Geol. Survey, vol. 13, 1SSS, p. 102; and H. Rosenbusch, Sitzungsb. K. Akad. Wiss. Berlin, 189S, p. 706. 

Washington's memoir is very full. On the glaucophane rocks of California, see J. P. Smith, Proc. Am. 

Philos. Soc., vol. 45, 1907, p. 1S3.

« L. Colomba, Zeitschr. Kryst.- Min. , vol. 26, 1896, p. 215. -

* On riebeckite rocks, see G. T. Prior, Mineralog. Mag., vol. 12, 1889, p. 92; P. Termier, Bull. Soc. min., 

vol. 27, 1904, p. 265; G. M. Murgoci, Am. Jour. Sci., 4th ser., vol. 20, 1905, p. 133. According to Murgoci, 

riebeckite forms only from persilicic magmas. Riebeckite rocks from Oklahoma are, described by A. F. 

Rogers in Jour. Geology, vol. 15, 1907, p. 2S3.

e W. C. Brogger, Zeitschr. Kryst. Min., vol. 10, 1900, pp. 407-410; also N. V. Ussing, idem, vol. 26, 1S96, 

p. 104.

' Brogger, op. cit., pp. 418-422.

» Am. Jour. Sci., 4th ser., vol. 26, 1909, p. 187.
ROCK-FORMING MINERALS. 385

Fayalite. Orthorhombic. Composition, Fe2Si04 . Molecular 

weight, 204.4. Specific gravity, 4 to 4.14. Molecular volume, 49.8. 

Color, yellow to brown and black. Hardness, 6.5.

Forsterite and fayalite are two minerals which, rare by themselves, 

are very common in isomorphous mixture. The usual mixture, in 

which the magnesium salt predominates, is known as olivine, chrysolite, or peridot. A variety containing a large amount of iron is called 

Lyalosiderite. Hortonolite is another member of the group, containing much iron, less magnesia, and about 4.5 per cent of manganese 

oxide. The compound Mn2SiO4 occurs as tephroite, and roepporite is 

a variety containing zinc. Knebelite is intermediate between fayalite 

and tephroite. All of these minerals are represented by the general 

orthosilicate formula R2Si04 . Titanic oxide, up to 5 per cent or 

more, may replace a part of the silica in olivine, forming a variety to 

which the name titanolivine has been given. 1

Monticellite. Orthorhombic. Composition, MgCaSi04 . Molecular weight, 188.9. Specific gravity, 3 to 3.25. Molecular volume, 61. 

Colorless to yellowish, greenish, or gray. Hardness, 5 to 5.5. The 

very rare glaucochroite, CaMnSi04 , is analogous to monticellite in 

composition.

The members of the olivine group are easily prepared by artificial 

means, and are of common occurrence in slags. 2

The first intentional synthesis of olivine was effected by Berthier, 3 

by simply fusing its constituent oxides together. Fouque" and Levy 4 

also obtained it by fusing silica and magnesia with ferrous ammonium sulphate. In their synthesis of basalt 5 they observed olivine 

among the earliest crystallizations from the magma. J. J. Ebelmen 6 

prepared forsterite by fusing a mixture of boric oxide, silica, and magnesia. In this case the boric oxide simply serves as a solvent of 

relatively low melting point, from which the synthetic mineral crystallizes just as ordinary salts crystallize from solution in water. A. 

Daubre"e 7 obtained olivine by recrystallization from fused meteorites, 

magnesian eruptive rocks, and serpentine. He also 8 prepared mixtures of olivine and metallic iron, resembling certain meteorites, by 

partial oxidation of an iron silicide and subsequent fusion of the

' See A. Damour, Bull. Soc. min., vol. 2, 1879, p. 15; and L. Brugnatelli, Zeitschr. ICryst. Min., vol. 30, 

1904, p. 209.

* See Fouque1 and L6 vy, Synthese des mineraux et des roches, p. 90; L. Bourgeois, Reproduction artiflciello 

des mine'raux, pp. 108-110; Vogt, Mineralbildung in Schmelzmassen, p. 8. A. Stelzner and If. Scliulzo 

(Neues Jahrb., 18S2, pt. 1 , p. 170) have described a slag containing a zinc-bearing fayalite; and H. Laspeyres 

(Zeitschr. Kryst. Min., vol. 7, 1SS3, p. 494) has reported another furnace product having the composition

» Cited by Fouqu6 and LCvy, op. cit., p. 97.

« Bull. Soc. min., vol. 4, 1881, p. 279.

6 Compt. Rend., vol. 92, 1SS1, p. 3C7.

« Annales chim. phys., 3d ser., vol. 33, 1851, p. 50.

' Compt. Rend., vol. 62, I860, pp. 200, 369, COO.

* Etudes synthe'tiques de geologic expGrimentale, p. 524.

113750° 19 Bull. 695 25
386 DATA OP GEOCHEMISTRY.

product. G. Lechartier * fused silica and magnesia with calcium w 

chloride, and P. Hautefeuille 2 operated with the same oxides and 

magnesium chloride. Olivine was produced in both cases when the 

oxides were in the proper proportions. By varying the proportions 

enstatite or enstatite and olivine together were formed. S. Meunier,3 

by heating magnesium vapor to redness in a mixture of water vapor 

and silicon chloride, obtained both olivine and enstatite. Fayalite .M 

was prepared by A. Gorgeu, 4 who heated ferrous chloride with silica 

to redness in a stream of moist hydrogen. Olivine is also formed 

according to C. Doelter,5 when hornblende is fused with calcium and ^ 

magnesium chlorides, and is among the products of fusion of biotite, 

vesuvianite, tourmaline, clinochlore, and some garnets. Forsterite f 

was obtained by E. T. Alien, F. E. Wright, and J. K. Clement 8 < 

incidentally to their preparation of magnesian pyroxenes. 

 Olivine is an essential pyrogenic constituent of many eruptive - 

rocks, such as peridotite, norite, basalt, diabase, and gabbro. Dunite 

is a rock consisting of olivine alone, or at most accompanied by 

trivial amounts of accessories. Since olivine, fused with silica, yields 

enstatite, it can occur normally only in rocks low in silica. As the 

latter increases in amount, pyroxenes take its place. Olivine, however, sometimes appears abnormally, as a minor accessory, in highly 

siliceous rocks like trachyte and andesite. Fayalite, for instance, was 

found by J. P. Iddings,7 associated with tridymite in lithophyses of 

rhyolite and obsidian, in the Yellowstone Park. A similar occur- >- 

rence in the Lipari Islands is reported by Iddings and S. L. Penfield.8 At Rockport, Massachusetts, fayalite has been found in 

granite.9 Olivine is also a common constituent of meteorites and is roften conspicuously associated with metallic iron. As products of 

thermal metamorphism olivine and forsterite are found in limestones 

and dolomites, frequently accompanied by spinel.10 The boltonite of -*-^ 

Bolton, Massachusetts, is an occurrence of this kind. * 

The members of the olivine group all undergo alteration with 

extreme facility. The typical alteration of peridotite rocks is into *- 

serpentine. By further changes, magnetite, magnesite, hydromagnesite, brucite, calcite, opal, and quartz may be formed. By oxidation of the iron silicate, limonite is produced. P. von Jereme'ef u has *

i Compt. Rend., vol. 67,1868, p. 41.

* Annales chim. ph.ys., 4th ser., vol. 4,1865, p. 129.

» Compt. Rend., vol. 93,1881, p. 737.

«Idem, vol. 98,1S84, .p. 920. *""

* Min. pet. Mitt., vol. 10,1888, p. 67; and Neues Jahrb., 1897, Band 1, p. 1.

6 Am. Jour. Sci., 4th ser., vol. 22,1906, p. 385. See also N. L. Bowen and O. Andersen, Am. Jour. Sci. 

4th ser., vol. 37, p. 487,1914.

' Am. Jour. Sci., 3d ser., vol. 30,1885, p. 58. ' ^ 

6 Idem, vol. 40,1890, p. 75.

9 See S. L. Penfleld and E. H. Forbes, Am. Jour. Sci., 4th ser., vol. 1,1896, p. 129.

10 See C. T. Clough and W Pollard, Quart. Jour. Geol. Soc., vol. 55,1899, p. 372. 

» Zeitschr. Kryst. Min., vol. 32,1900, p. 430.
ROCK-FORMIATG MINERALS 387

described pseudomorphs of talc, serpentine, and epidote after olivine. 

The olivine was first transformed to serpentine, that into epidote, and 

that finally into talc and clay. Pseudomorphs of hornblende after 

olivine are recorded by F. Becke * and B. Kolenko.2 By a reaction 

between olivine and feldspar, according to K. Brauns,3 a pyroxene 

can be formed, Monticellite alters into serpentine and pyroxene; 

and C. H. Warren 4 found a ferrous anthophyllite, FeSi03 , derived 

from the fayalite of Rockport.

THE MICAS.

Muscovite. Monoclinic. Composition, normally Al3KH2Si3012 . 

Molecular weight, 399.6. Specific gravity, 2.85. Molecular volume, 

140. Colorless when pure, but usually tinted slightly by impurities. 

Hardness, 2 to 2.5.

Some varieties of muscovite differ from the normal compound in 

containing a higher proportion of silica. These all represent admixtures of the isomorphous trisilicate Al3KH2SiB 024 . Fuchsite is a 

muscovite containing small amounts of chromium, replacing aluminum. Baddeckite 5 appears to be a muscovite containing much ferric 

iron, due to admixtures of the compound Fe3KH2Si 3O12 . F. W. 

Clarke and N. H. Barton 8 have described an altered mica which 

seems to be derived in part from the same ferric salt. Koscoelite is 

similar, but with nearly two-thirds of the aluminum replaced by 

vanadium.7 Sericite, margarodite, damourite, gilbertite, etc., are 

muscovites of secondary origin.

Pamgonite. Monoclinic. A sodium mica, Al3NaIl2Si3O12 , correspending to muscovite. Molecular weight, 383.5. Specific gravity, 

2.9. Molecular volume, 132.2. Color, like muscovite. Hardness, 

2,5 to 3.

Lepidolite. Monoclinic. A lithia-bearing mica of variable composition. In most cases .a mixture of a fluoriferous trisilicate, 

AlF2 .Si308 .R/3 , in which R'= (Li,K), with molecules of the muscovite 

type. Color commonly rose-red or lilac, but also white, gray, or brown. 

Specific gravity, 2.8 to 2,9. Cookeite, 8 Al3LiH(Si04 ) 2 (OH) 3 .H20, is 

probably a derivative, by hydra tion, of lepidoiite; but it may be 

an alteration of tourmaline. Polylithionite is another lithia mica 

in which the ratio Si:O is entirely trisilicate. The separate existence of such a compound among the micas sheds much light upon 

their constitution; but of that, more later. Zinnwaldite and cryoi Min. pet. Mitt., vol. 4,1882, p. 450.

»Neues Jahrb., 1885, Band 2, p. 90.

»Idem, 1898, Band 2, p. 79.

«Am. Jour. Sci., 4th scr., vol. 16,1903, p. 337.

s G. C. HofEmaiin, Ann. Kept. Geol. Survey Canada, vol. 9,189G, p. 11 R.

«Bull. U. S. Geol. Survey No. 167,1900, p. 154.

i F. W. Clarke, idem, p. 73.

« See Clarke, Bull. U. S. Geol. Survey No. 588,1914, p. 67
388 . DATA OF GEOCHEMISTRY.

phyllite are other lithia micas containing iron and intermediate in 

composition between lepidolite and the ferruginous biotites. Lepidolite is found chiefly, if not exclusively, in albitic pegmatite veins and 

has little significance as a rock-forming mineral.

Biotite. Monoclinic. Normal composition, A] 2Mg2KHSi3O12 , but 

with admixtures of the corresponding ferric and ferrous salts in 

variable proportions. Molecular weight of the normal biotite, 420.3. 

Specific gravity, 2.7. Molecular volume, 155.6. The specific gravity 

of the iron biotites may reach 3.1. That is the density of siderophyllite, which is very near to the normal ferrous biotite in composition 

and has a molecular volume of 155.9. There are also biotites containing small amounts of chromium, barium, manganese, etc. Color, 

in biotite generally, green to black, rarely white, sometimes yellow 

to brown. Hardness, 2.5 to 3.

PJilogopite. Monoclinic. Composition variable; typical phlogopite approximates to AlMg3KH2Si3Oi2 . Usually contains a low proportion of water and some fluorine; also iron in small quantities. 

Normal molecular weight, 418.6. Specific gravity, 2.75. Molecular 

volume, 152.2. Color, brown, yellowish, reddish, greenish, sometimes white. Hardness, 2.5.to 3. Between phlogopite and biotite 

there are many intermediate mixtures; and the varieties containing much ferric iron are known as lepidomelane. The ratios of the 

latter are commonly near those of biotite.

CTiloritoid. Monoclinic. 1 Composition, Al2Fe''H3SiO7 ; being a 

very basic orthosilicate. Some magnesia or manganese may replace 

a part of the iron. Molecular weight, 252.5. Specific gravity, 3.45. 

Molecular volume, 73.2. Color, gray, greenish gray, and grayish or 

greenish black. Hardness, 6.5. Ottrelite, which is an important 

constituent of some schists, is probably the trisilicate corresponding 

to chloritoid, Al2FeH2Si3On. These minerals, together with margarite, seybertite, and xanthophyllite, form the clintonite group, or 

so-called brittle micas. They are all foliated, micaceous minerals, 

extremely basic, and free from alkalies. The true ferromagnesian 

micas often contain admixtures of these basic molecules.

Although muscovite is very simple in its constitution, the other 

micas, including the clintonite series, are quite complex. Just as in 

the pyroxene and amphibole groups, we have to deal with isomorphous 

mixtures of different salts, which vary not only to some extent in type, 

but also in their "replacements" of aluminum by iron or chromium, 

potassium and hydrogen by sodium or lithium, and magnesium by 

iron or manganese. In some of the brittle micas calcium also appears, 

and in lepidolite and phlogopite the equivalency of hydroxyl and 

fluorine has to be taken into account. Furthermore, the ferromagnesian micas are highly alterable by hydration; and it is not always 

. : 

« Triclinic according to H. F. Keller and A. C. Lane, Am. Jour. Sci.,3d ser., vol. 42,1891, p. 499.
ROCK-FORMING MINERALS. 389

possible to be certain whether a change of that order may not have 

begun. In spite of all difficulties, however, the normal micas can be 

expressed by a smaller numbef of generalized formulae, which are all 

derivable from one general type, as follows:

Muscovite, R'"8R'8(Si04 )8 and R'"8R'8 (Si08,3 . 

Biotite, R'"aR"aR'a (Si04 )8 and R///2R//2R/2(Si308 )3 . 

Phlogopite, RwIR"3R'3 (Si04 ) 8 and Rw1T^3R'3 (Si308 )3 .

According to J. Uhlig, 1 the rare mineral kryptotile, an alteration 

product of prismatine, is an end member of the muscovite series, 

with formula Al3H3 (Si04 ) 3 . Possibly the claylike mineral leverrierite 

may be akin to kryptotile. To these normal micas must be added 

two basic types, R'"F2 .Si308R'3 in lepidolite, zinnwaldite, and some 

phlogopites, and the clintonite molecule R'"02R".Si808 .R'3, with 

its orthosilicate equivalent R'"0.jR".Si04R'3 . To each of these 

forms a known mica corresponds, so that the expressions involve no 

assumptions of hypothetical molecules. In G. Tschermak's theory 

of the mica group,2 hypothetical compounds are invoked with which 

no actual micas agree.

Several syntheses of mica have been reported, but they are not altogether satisfactory, for the reason that the products obtained were 

not, except in one instance, verified by analysis. Unfortunately, a 

large proportion of the work so far done in synthetic mineralogy has 

been purely qualitative, and therefore incomplete. A substance may 

be micaceous and yet a different thing from any natural member of 

the mica group. The true micas, as a rule, are hydrous minerals; 

water is one of their essential constituents; syntheses by igneous 

methods, at ordinary pressures, are therefore to be regarded with suspicion. Some phlogopites are nearly anhydrous, however, and it 

would be unwise to condemn the reported syntheses without further 

investigation. The magnesian mica, described and partly analyzed 

by J. H. L. Vogt,3 from the slags of the Kafveltorp copper works in 

Sweden, may have been a phlogopite of the type just indicated, with 

its hydroxyl replaced by some other monad radicle. To Fouque" 

and LeVy's 4 syntheses of a mica trachyte, the objections just cited do 

not apply. They heated a powdered granitic glass with a little water, 

under pressure, and for a long time, to redness, and obtained an artificial rock in which scales of mica were visible. In this synthesis 

water played a distinct part.

By the prolonged heating of andalusite with a solution of potassium 

carbonate and potassium fluoride at 250°, C. Doelter 5 obtained scales

'Zeitschr. Kryst. Min., vol. 47,1910, p. 215. See also A: Sauer, Zeitschr. Deutsch.geol. Gesell. vol.38, 

188G,p.705.

sZoitschr. Kryst. Min.,vol.2,1878, p. 14; vol.3,1S79, p. 122. 

8 Berg- u. Huttenm. Zeitung, vol. 47, p. 197. 

« Compt. Rend., vol. 113,1891,p. 2S3. 

s Allgemeine chemische Mineralogie, p. 207.
390 DATA OF GEOCHEMISTRY.

of white mica. This transformation is instructive, for andalusite 

-alters into muscovite quite readily. P. Hautefeuille and L. P. de 

Saint-Gilles 1 fused the constituents of an iron mica with potassium 

silicofluoride and found crystals resembling mica in their product. 

K. Chrustschoff's 2 work was more definite. He fused a mixture 

equivalent to a mica basalt with the fluorides of sodium, aluminum, 

and magnesium, and also with potassium silicofluoride. After very 

slow cooling, the mass contained a micaceous mineral, which was 

separated and analyzed. It was essentially an anhydrous biotite. 

J. Morozewicz 3 added about 1 per-cent of tungstic acid to a mixture 

having the composition of rhyolite, and obtained, after prolonged 

fusion and slow cooling, tables of biotite.

C. Doelter,4 in a series of memoirs, reports the formation of micas 

by the fusion of various natural silicates with fluorides. Hornblende, 

augite, pyrope, almandite, and grossularite, fused with sodium fluoride and magnesium fluoride, yielded, among other products, biotite. 

It must, however, have been a sodium biotite, for the materials used 

seem to have contained no potassium. Glaucophane treated in the 

same way gave a phlogopite. Leucite, with sodium or potassium 

iluoride, was converted into an alkali mica and with magnesium 

fluoride yielded biotite. Andalusite, heated to redness with potassium silicofluoride and aluminum fluoride, gave muscovite, and when 

lithium carbonate was added to the mixture a lithia mica was 

obtained. An artificial mixture corresponding to KAlSi04 + Mg2SiO4 , ,*> 

fused with sodium and magnesium fluoride, also formed biotite. 

From other mixtures he produced muscovite, phlogopite, and an iron 

mica. None of these products seems to have been analyzed, and as 1- 

their generation is ascribed to presumably anhydrous materials, it is 

probable that they were analogous to rather than identical with the 

natural micas. Possibly they were micas containing fluorine in place -vof hydroxyl. In nearly all the reported syntheses of mica fluorides 

have played an important part, but their exact function is unknown.

Primary muscovite is essentially a mineral of the deep-seated * 

rocks, especially of the granites and quartz porphyries. It is never 

found in recent eruptives. From its water content we may infer 

that it was formed under pressure. Muscovite is also abundant in ** 

mica schist, and paragonite is similarly found in a paragonite schist. 

As an alteration product of other minerals muscovite is very common. 

Feldspar, topaz, andalusite, kyanite, nephelite, spodumene, the scapo- *~ 

lites, and various other silicates alter readily into mica. Pinite and 

several other pseudomorphous minerals of like character consist of 

muscovite more or less impure. Lepidolite is probably in many cases *~

1 Compt. Rend., vol. 104,1887, p. 508. , 

«Min.pet.Mitt., vol. 9,1887,p. 55. . * 

'NeuesJahrb.,1893, Band 2, p. 48. 

4 Idem, 1888, Band 2, p. 178; 1897, Band 1, p. 1. Also Min. pet. .Mitt., vol. 10,1888, p.i>7. *~
EOCK-FOKMIKG MUSTEKALS. 391

_ secondary after muscovite, for ifc often forms margins upon plates of 

the latter mineral. Cryophyllite forms similar margins upon lepidomelane.

Biotite is an important constituent of many massive igneous rocks, 

such as granite, syenite, diorite, trachyte, andesite, mica basalt, etc. 

It forms among the earliest secretions, immediately following the

^ ores, apatite, and zircon. It is sometimes altered by magmatic corrosion to a mixture of augite and magnetite. 1 Pressure seems to condition its formation. Phlogopite occurs chiefly in granular Archean

k limestones and in serpentine; but W. Cross 2 has described it as a 

constituent of a peculiar igneous rock, wyomingite. Chloritoid 

and ottrelite are found only in phyllitic schists,3 and are of minor

_v importance.

Muscovite, under ordinary conditions, is one of the least alterable 

of minerals. The feldspar of a granite may be completely kaolinized, while the embedded plates of mica retain their brilliancy almost 

unchanged. By treatment with aqueous reagents at 500°, however, 

C. and G. Friedel 4 transformed muscovite into nephelite, sodalite,

^ leucite, orthoclase, and anorthite. Upon fusion, according to C. 

Doelter, 5 muscovite breaks up into leucite glass, and a substance 

resembling nephelite. Lepidolite and zinnwaldite behave in a similar 

manner. W. Vernadsky 8 observed corundum and sillimanite among 

. the fusion products of mica. From the composition of muscovite a 

splitting up into water, leucite, and sillimanite m&y be inferred, 

according to the equation 

Al3KH,Si3O12 = AlKSi2O8 +Al,8i05 + H,,O;

and with this the reported derivation of muscovite from leucite can 

be correlated. 7 Biotite, according to Doelter, yields no leucite Upon 

fusion, but breaks up into olivine and spinel, with other less completely identified substances. On the other hand, H. Backstrom 8 

fused biotite and found olivine, leucite, a little spinel, and glass to 

be the substances formed by its decomposition.

Unlike muscovite, biotite and phlogopite alter easily, and pass into 

a series of apparently indefinite substances known as "vermiculites." 

The change, however, is very simple, and consists merely in the 

replacement of the alkaline metals by hydrogen, with assumption of

.. i For a discussion of this alteration,see H. S. Washington, Jour. Geology, vol. 4,1896, p. 257. 

2 Am. Jour. Sci., 4th ser., vol. 4,1897, p. 115.

i See A. Cathrein, Min. pet. Mitt., vol. 8,1887, p. 331; and L. van Werveke, Neues Jahrb., 1885, Band 

l,p.227.

« Compt. Rend., vol. 110,1890, p. 1170. 

-» s Neues Jahrb., 1897, Band 1, p. 1.

« Cited by Morozewicz, Min. pet. .Mitt., vol. 18,1898, p.26.

* See Doelter's experiment,cited above.

s Geol. Foren. Forhandl., vol. 18,189C, p. 162.
392 DATA OF GEOCHEMISTRY.

additional, loosely combined water. From the typical ferromagnesian micas the following derivatives are thus formed:

From AlaMg2KHSi3O ia ...... AUIg2H2Si3012 .3H20.

From AlMg2 kH2Si3013 ...... A]Mg3H3Si 3012 .3H26.

From any mixture of biotite and phlogopite molecules the corresponding hyclrated mixture may be generated. These compounds, 

so simply related to the parent substances, form a series intermediate 

between the micas and the chlorites and mark a transition into the 

latter group of minerals, which will be considered next in order. 1

THE CHLORITES.

Under this general name a considerable number of minerals are 

embraced which are closely related to the micas. They are, however, much more basic, highly hydrated, and free from alkalies. 

They are silicates of aluminum or ferric iron, with magnesium or 

ferrous iron, and resemble the micas crystallographically as well as in 

the scaly or foliated habit which they commonly assume. The following species are recognized by Dana,2 who assigns to them the 

annexed empirical formulse:

Clinochlore. ............................

 « -x Penmmte...-............--.............

Prochlorite...............................H40(Fe,Mg)23Al 14Si13090.

Corundophilite.............................. H20(Fe,Mg)uAl8Sia046 .

Daphnite.................................H56Fe27Al29Si18Oj21 .

Cronstedtite.............................. H6 (Fe > Mg) 8Fe"'aSiaOI8.

Thuringite................................H18Fe8(Al; Fe)sSiG041 .

Stilpnomelane.............................

Strigovite..................................H4 (Fe,Mn)2 (Fe,Al)2Si2O n .

Diabantite................................H18(Mg,Fe) 12Al4Si9045 .

Aphrosiderite.............................. H10(Fe,Mg)6Al4Si4025 .

Delessite...................................H10(Mg,Fe)4Al 4 Si4 022 .

Rumpfite.................................. H28Mg7Ali G Si10Oe5 .

To these may be added the more or less uncertain minerals amesite, 

metachlorite, klementite, chamosite, epichlorite, etc.

None of the formulae given above is fixed and definite, for each of 

the many "chlorites" is variable in composition. The minerals, like 

the ferromagnesian micas, are mixtures of compounds, and several 

attempts to disentangle their components have been made.3 The 

simplest and most natural interpretation of the chlorites represents

1 On the alteration products of the magnesian micas, see E. Zschirnmer, Jenaische Zeitschr., vol. 32,1898, 

p. 551. On the action of water upon micas, A.Johustone,Quart. Jour.Geol.Soc., vol.45,1889, p.363. For 

analyses of vermiculites, see E. S.Dana, System of mineralogy, 6th ed., pp. 664-668; also F. W. Clarkeand 

E. A. Schneider,Bull.U.S.Geol. Survey No. 78,1891;Bull. No. 90,1892. Theearlier papersof J. P. Cooke 

and F. A. Genth are also important.

«System of mineralogy, 6th ed., p. 643.

* See G. Tschcrmak, Sitzungsb. K. Akad. Wiss. Wien, vol. 99, Abth. i, 1S90, p. 174: vol. 100. Abth. l, 

p. 29. R. Brauns, Neucs Jahrb., Band 1,1894, p. 205, and Chemische Mineralogie, p. 221. F. W. Clarke, 

Bull. U. S. Gcol. Survey No. 588, 1914, pp. 59-65. An earlier discussion by Clarke, on different lines, is 

given in Bull. U. S. Geol. Survey No. 113,1893, p. 11.
BOCK-FOE MI NG MINERALS. 393

 s them as formed from a series of compounds parallel with those identified in tho micas and vermiculites, according to the following 

scheme:

. . Normal micas. Vermiculites. Normal chloritcs.

Al 3KH2 (Si04 )3 . ........................ ..........................

Al2Mg2KH(Si04 )3 . Al2Mg2H2 (Si04 )3 .3H20. Al2 (MgOH)4H2 (Si04 )3 .

A1Mg3KH2 (Si04 )3 . AlMg3H3 (Si04 )3 .3H20. Al(MgOH)6H3 (Si04 )3 .

* A102Mg.Si04 .R'3 . A102Mg.Si04RY3H20. A102Mg.Si04 .R'3 .

On this basis the relations between the several series are clear and 

in accord with the natural occurrences of the minerals. In penninite

* and clinochlore we have varying mixtures of the first and second 

chloritic types, just as among the micas we find examples intermediate between biotite and phlogopite. Prochlorite appears to be a

"* derivative of the last molecule, having the formula 

A103R'.SiO«. (R"OH)H2 ,

 * in which R," is partly Fe and partly Mg. 1

It is obvious, from their hydrous character, that the chlorites can 

not form as pyrogenic minerals. They are always of secondary

-* origin; and when they appear in volcanic rocks it is as the result of 

hydrothermal alteration. Almost any aluminous ferromagnesian 

mineral may yield a chlorite in this way. Augite, hornblende, biotite, vesuvianite, epidote, tourmaline, or garnet may be the parent 

mineral.2 Chlorites have been produced artificially by G. Friedel 

and F. Grandjean, 3 by the action of alkaline solutions on pyroxenes. 

When a magnesian chlorite, such as clinochlore, is strongly ignited,

^. it breaks down into a soluble and an insoluble portion, and the latter 

has the composition of spinel. 4 This fact is strong eATidence against 

Tschermak's theory of the chlorite group, in which the normal series 

is regarded as formed by mixtures of serpentine, H4Mg3Si200, with 

amesite, H4Mg2Al2SiOa . For serpentine, on ignition, splits up into 

water, olivine, and enstatite, and the last-named mineral does not 

appear among the decomposition products of clinochlore. The latter, 

therefore, contains no serpentine, and the theory which assumes its 

presence falls to the ground. C. Doelter 5 reports spinel, olivine, 

and augite as formed by the fusion of clinochlore; but the experiments conducted in the laboratory of this Survey exclude the insolu-

? ble augite from the list of probabilities.

Chlorites are abundant among the metamorphic schists, chlorite 

schist being the commonest occurrence. An interesting metamorphosis of such a rock, a phyllite containing approximately 75 per cent of

_ > For the other chloritic minerals see F. W. Clarke, Bull. U. S. Gcol. Survey No. &8B, 1914, pp. 59-G5.

* For a complete discussion of pseudomorphous chlorite after pyrope, see J. Lemberg, Zeitschr. Deutsch. 

geol. Gcsell./vol. 27,1875, p. 531. 

8 Bull. Soc. min., vol. 32,1909, p. 150. 

« F. W. Clarke and E. A. Schneider, Bull. U. S. Geol. Survey No. 113,1893, pp. 27-33.

** oNcucs Jahrb., 1897, Band l,p. 1.
394 DATA OF GEOCHEMISTRY.

muscovite with. 25 of chlorite, is reported by K. Dalmer.1 With 

almost no change of composition, other than loss of water, it was 

transformed into a mixture of andalusite and biotite.

THE MELILITE GBOUP.

Melilite, Tetragonal. A silicate of aluminum and calcium of 

variable composition, with Fe"' replacing some Al, and Mg or Na 

replacing a part of the Ca. Specific gravity, 2.9 to 3.1. Hardness, 5. 

Color, white, yellow, greenish yellow, brown.

Gehlenite. Tetragonal. Composition variable, as with melilite. 

The formula commonly assigned to gehlenite, Al2Ca3Si,O10 , is not 

sustained by the best evidence. Specific gravity, 3. Hardness, 

5.5 to 6. Color, grayish green to brown.

Akermanite. Tetragonal. Composition, Ca4Si3Olo, with about onethird of the calcium replaced by magnesium. According to A. L. 

Day and E. S. Shepherd 2 a calcium silicate of this formula can not 

be deposited from lime-silica fusions. The magnesia is essential to 

its formation. Ordinarily found only in slags, but the natural mineral has been reported by F. Zambonini 3 as occurring in calcareous 

blocks at Monte Sonima.

Sarcolite. Tetragonal. Composition, Al2 (Na2Ca) 3Si3O12 . Specific 

gravity, 2.93. Hardness, 6. Color, reddish white to rose-red. 

Known only from Monte Sonnna.

These four isomorphous silicates are closely related to one another. 

J. H. L. Vogt 4 regards gehlenite and akermanite as the two independent species, which, isomorphously commingled, form the variable melilite. This view is plausible, but not universally accepted. 

Furthermore, although melilite is a pyrogenic mineral characteristic 

of certain eruptive rocks, natural gehlenite has been found only as a 

product of contact metamorphism in limestones. If gehlenite were 

a constituent of melilite, we should expect to find igneous rocks in 

which it appeared as an essential component, or at least as a conspicuous accessory. A more probable interpretation of melilite and 

gehlenite treats them as intermediate mixtures of silicates analogous 

to the plagioclase feldspars. One such silicate, Al2Ca2Si07, has 

been prepared synthetically by E. S. Shepherd and G. A. Rankin in 

the Geophysical Laboratory of the Carnegie Institution. It is 

easily formed by direct fusion of a mixture of its component oxides. 

The other silicate, Al 2Ca9 (SiO4 ) e is not known by itself, but is approxi1 Ncues Jahrb., 1897, Band 2, p. 156.

2 Am. Jour. Sci.,4th ser., vol. 22,1506, p. 265.

3 Mineralogia vesuviana, p. 255.

* MineralbildunginSclnnelzmassen, 1892, pp. 96-176. See also 0. Bodlander, Neues Jahrb., Sand 1,1893, 

p. 15; and F. Fouque, Ball. Soc. min., vol. 23, 1900, p. 10. Also a more recent -ciiscussion by Vogt, Die 

Silikatschmelzlosungen, pt. 1, 1903, p. 49. F. Zambonini (Zeitscnr. Kryst. Min., vol. 41, 1906, p. 226) 

has advanced strong arguments against Vogt's toypotaesis.
ROCK-FORMING MINERALS. 395

mated by some artificial gehlenites. It is nearly related in structure 

to minerals of the garnet and scapolite groups. 1

One objection to Vogt's interpretation of the melilite group is 

that akermanite, being nonaluminous, is a compound of very different 

type from the other minerals. It is included, however, in the scheme 

proposed by W. T. Schaller, 2 who regards melilite and gehlenite as 

mixtures of four silicates, namely, akermanite, lime sarcolite, soda 

sarcolite, and the artificial compound Al2Ca2SiO7 . Here again compounds of unlike type are brought together, and although the analyses 

of melilite and gehlenite can be interpreted quite accurately by 

Schaller's method, something more general seems to b® needed. 

These minerals are closely related to other lime-alumina silicates, 

namely, to garnet, prehnite, anorthite, zoisite, vesuvianite, and 

meionite, which are all similar in composition although different in 

form. Their relations to one another are expressed by the forinulEe 

proposed by F. W. Clarke, 3 who regards melilite as a mixture of the 

two sarcolites with the compound Al 2 (Si04 ) 6Ca0 in varying proportions. The last compound is hypothetical, although some artificial 

melilites approach it in composition. In gehlenite we seem to have 

the same compound, with sometimes sarcolite, and another hypothetical basic silicate, Al2 (Si04 ) 6Ca6 (AlO2Ca) 6 . With these formulae 

the relations mentioned above are shown very clearly. Their full 

discussion will appear later, in the section on constitutional formulae, 

in Chapter XIV.

Both melilite and gehlenite are common minerals in slags, 4 and both 

have been prepared synthetically. An artificial melilite basalt was 

prepared by J. Morozewicz, 5 and the mineral was also found by 

Fouque" and Levy 6 among the constituents of some of their synthetic 

rocks. In Morozewicz's preparation the melilite was accompanied 

by augite, plagioclase, olivine, corundum, and spinel. Melilite and 

feldspar were the last silicates to crystallize from the magma. F. 

Fouque 7 has shown that melilite is formed when an augite andesite 

or a basalt is fused with lime, and he gives analyses of two products 

thus obtained. G. Bodlander 8 found melilite in a sample of Portland 

cement; but according to Vogt 9 the mineral was not pure. L. Bourgeois 10. prepared melilite by direct fusion of silica, lime, alumina, and 

certain other oxides commingled in proper proportions, but could

1 See F. W. Clarke, Bull. U. S. Geol. Survey No. 588,1914, pp. 31-34.

2 Bull. U. S. Geol. Survey No. 610,1916, pp. 106-126.

8 Am. Jour. Sci., 4th ser., vol. 43,1917, p. 476.

< See L. Bourgeois, Reproduction artificielle des mine'raux, p. 123. J. H. L. Vogt, Mmeralbildung in 

Schmelzmassen, 1892. F. Fouque', Bull. Soc. inin., vol. 9, 1886, p. 287. P. Heberdey, Zeitschr. Kryst. 

Min., vol. 26,1896, p. 19. J. S. Diller, Am. Jour. Sci., 3d ser., vol. 37,1889, p. 220.

 * Min. pet. Mitt., vol. 18,189S, p. 191.

8 Bull. Soc. min., vol. 2,1879, p. 105.

1 1dem, vol. 23,1900, p. 10.

8 Neues Jahrb., Band 1,1892, p. 53.

»Idem, Band 2,1892, p. 73. 

M Annales chim. phys., 5th ser., vol. 29,1883, p. 450.
396 - DATA OF GEOCHEMISTRY.

not obtain the calcium alumosilicate alone. The presence of iron, 

magnesia, or manganese was essential to a successful synthesis. Soda 

also is probably essential; at all events, melilite forms more readily 

when soda is present. All natural melilite contains soda. C. Doelter 

and E. Hussak 1 found melilite among the fusion products of garnet 

and vesuvianite, and Doelter 2 reports it also as formed when tourmaline is fused with calcium chloride and sodium fluoride. The synthesis 

of gehlenite was effected by L. Bourgeois, 3 who simply fused the constituent oxides together in the proportions indicated by the formula 

of the species.

Melilite is a mineral found only in the younger eruptives; never 

in the plutonic rocks or crystalline schists. It is frequently associated 

with nephelite or leucite, and sometimes takes the place of feldspar. 

Perofskite is one of its most constant companions. Its origin is 

always pyrogenic. 4 Its most remarkable occurrence is in the Uncompahgre quadrangle, Colorado, where it forms about two-thirds of a 

rock which contains also pyroxene, magnetite, perofskite, and apatite, 

with other minor accessories. The melilite is enormously developed, 

and cleavages a foot across are not rare. 5

Alterations of melilite seem to have been little studied. A. Cathrein 6 has described pseudomorphs of pyroxene (fassaite) and grossularite after gehlenite. By heating gehlenite with a solution of 

potassium carbonate to 200°, J. Lemberg 7 obtained calcium carbonate 

and an amorphous product having the composition of a potassium 

mica. A fibrous, zeolitic alteration of the Uncompahgre melilite, 

cebollite, has been described by E. S. Larsen and W. T. Schaller. 8

THE GARNETS.

Grossularite. Isometric. Composition, Ca3Al2Si3012 . Molecular 

weight, 451.7. Specific gravity, 3.5. Molecular volume, 129. Color, 

white, yellow, brown, and sometimes pale green or rose-red. The coloration is due to impurities.

Pyrope. Isometric. Composition, Mg3Al2Si3012 . Molecular weight, 

404.6. Specific gravity, 3.7. Molecular volume, 109.4. Color, deep 

red to nearly black.

Almandite. Isometric. Composition, Fe3Al2Si3O12 . Molecular 

weight, 499.1. Specific gravity, 3.9 to 4.2. Molecular volume, 118.

1 Neues Jahrb., 188-1, Band 1, p. 159.

2 Idem, 1897, Band 1, p. 1.

8 Annales chim. phys., 5th set., vol. 29,1883, p. 448.

« For data upon melilite rocks see A. E. Tornebohm, Geol. Fb'ren. Forhandl., vol. 6, 1882, p. 240. A. 

Stelzner, Neues Jahrb., Beil. Band 2,1883, p. 309. F. D. Adams, Am. Jour. Sci., 3d ser., vol. 43,1892, p. 

2C9. C. H. Smyth, idem, vol. 40,1893, p. 104. The last two references deal vrith American occurrences.

» See E. S. Larsen and J. F. Hunter, Jour. Washington Acad. Sci., vol. 4,1914, p. 473.

«Min. pet. Mitt., vol. 8,1887, p. 400.

* Zcitschr. Deutsch. geol. Gescll., vol. 44,1892, p. 237.

8 Jour. Washington Acad. Sci., vol. 4, 1914, p. 480.
ROCK-FORMING MINERALS. 397

* Color, red to brown and black. Pyrope and almandite shade one into 

the other through varying mixtures of the iron and magnesium compounds.

f Spessartite. Isometric. Composition, Mn3Al2Si3Oi2 . Molecular 

weight, 496.4. Specific gravity, 4.2. Molecular volume, 118. Color, 

red to brown.

,*. Andradite, melanite, or common garnet. Isometric. Composition, 

Ca3Fe"'2 Si3O]2 . Molecular weight, 509.3. Specific gravity, 3.85. 

Molecular volume, 158.2. Color, green, yellow, brown, or black.

>. Uvarovite. Isometric. Composition, Ca3Cr2Si3012 . Molecular 

weight, 501.7. Specific gravity, 3.5. Molecular volume, 143. Color, 

emerald-green.

> The foregoing six species, with their many isomorphous mixtures, 

form the important garnet group. With them may be included the 

rare mineral schorlomite, which contains titanium partly replacing

, silicon and ferric iron. Its formula is Ca3 (Fe,Ti ///) 2 (SiTiiv) 3 012 . 1 

The sodium garnet lagoriolite, Na6Al2Si3 012 , which was obtained by 

J. Morozewicz 2 from some of his artificial magmas, also belongs here.

_^ Its existence accounts for the small amounts of alkalies which appear 

in some analyses of grossularite, although they may be clue in part to 

inclusions. Garnets are peculiarly prone to carry other species as 

inclosures within their crystals. Some garnets are hardly more than 

shells enveloping other species. 3

Although garnet is undoubtedly a pyrogenic mineral, its synthesis 

is attended by considerable difficulties. When fused by itself garnet 

breaks up into other compounds. C. Doelter and E. Hussak, 4 upon

* fusing garnets alone, obtained meionite, melilite, anorthite, lime 

olivine, a calcium nephelite (?), hematite, and spinel, the products 

varying with the -composition of the original mineral. By fusing

*"A grossularite with sodium and magnesium fluorides, Doelter 5 obtained 

biotite, anorthite, meionite, olivine, and magnetite. L. Bourgeois,6 

from the fusion of a mixture equivalent to grossularite, obtained

^ anorthite and monticellite; and J. H. L. Vogt 7 reports anorthite as 

formed under similar conditions. When magnesia, oxide of manganese, or iron oxide was added to Vogt's mixture, melilite was also

,> _____ . 

i R. Soltmann (Zeitschr. Kryst. Min., vol. IS, 1891, p. 628) has described a melanite garnet containing 

11.01 per cent of Ti02, which should probably be partly reduced to Ti2 03 .

^ Min. pet. Mitt., vol. 18. 1898, p. 147.

 3 For systematic papers on the garnet group see W. C. Brb'gger and H. Bilckstrom, Zeitschr. Kryst. Min., 

vol. 18,1891, p. 209; E. Weinschenk, idem, vol. 25.1896, p. 365; H. E. Boeke, idem, vol. 53,1913, p. 149; 

and J. Uhlig, Verhandl. Naturhist. Verein preuss. Rheinlande u. Westfalens, vol. 67,1911, p. 307. Uhlig 

gives many analyses. A garnet intermediate between spessartite and andraditc has been named spandite 

by Fermor. Grandite is another intermediate between grossularite and andradite. See Rec. Geol. Survey 

w India, vol. 42, 1912, p. 208.

< Neues Jahrb., 1884, Band 1, p. 158.

«Idem, 1897, Band 1, p. 1.

 Annalcs chiin. phys., 5th ser., vol. 29,1883, p. 458.

i Mincralbildung in Schmelzmassen, 1892, p. 187.
398 DATA OF GEOCHEMISTRY.

produced. The syntheses of garnet reported by several early inves- 

.tigators l are of doubtful authenticity.

Bourgeois, however, in the research just cited, prepared spessartite 

by fusing together its constituent oxides in the proper proportions. 

A. Gorgeu 2 also obtained spessartite when pipe clay was fused with 

an excess of manganese chloride. A similar fusion with calcium 

chloride gave, with other products, crystals which were possibly 

grossularite. Fouque and Levy 3 report melanite as formed when 

nephelite and pyroxene are fused together. L. Michel * produced 

melanite and sphene by heating a mixture of ilmenite, silica, and calcium sulphide to 1,200°. In this case the artificial melanite was verified by analysis. E. S. Shepherd and G. A. Rankin 5 mention, but 

without details, the formation of grossularite by the action of aluminum chloride upon calcium orthosilicate under pressure.

Apparently pyrogenic garnet can be produced only during a limited 

range of temperatures, and the success of an attempted synthesis 

.depends upon securing the exact conditions. Pressure, also, may 

exert some influence upon the process.6

Garnet, especially andradite, is an exceedingly common mineral, 

and is found as an accessory in a great variety of rocks. Grossularite is found principally in crystalline limestones, where it has been 

developed by contact metamorphism. Almandite and andradite are 

common in granitic rocks, gneisses, etc. Andradite also occurs as an 

accessory mineral in subsilicic eruptives, especially in leucite and 

nephelite rocks. It is also found in serpentines, in iron ore beds, and 

as a product of contact action, associated with wollastonite and 

pyroxene, in certain volcanic rocks. Pyrope is often found in peridotites and the serpentines derived from them. Spessartite occurs in 

granite, quartzite, and some schists, W. Cross 7 has reported it from 

lithophyses in rhyolite. Garnets are also abundant in many crystalline schists, such as garnet rock, garnet amphibolite, garnet hornfels, 

garnet-mica schist, etc. Eclogite is a rock in which garnet and a 

green pyroxene are the principal minerals. Kodurite, an igneous 

rock described by L. L. Fermor,8 consists chiefly of orthoclase, garnet 

(spandite or grandite), and apatite.

Alterations of garnet are exceedingly common. A. Cathrein, 9 

describing the rocks of a single region, reports pseudomorphs after 

garnet of scapolite, epidote, oligoclase, hornblende, saussurite, and

1 See Fouque' and L6vy, Synthese des mindraux et des roches, p. 122.

2 Annales chim. phys. 6th ser. vol. 4,1885, pp. 536,553.

3 Compt. Rend., vol. 87,1878, p. 962. 

< Idem, vol. 115,1892, p. 830. 

5 Am. Jour. Sci., 4th ser., vol. 28,1909, p. 305.

s See L. L. Fermor (Rec. Geol. Survey India, vol. 43, pt. 1,1913, p. 41, and Jour. Asiatic Soc. Bengal, 

vol. 8,1912, p. 315) on the probable formation of garnet at great depths, 

i Am. Jour. Sci., 3d ser., vol. 31,1886, p. 432. 

a Rec. Geol. Survey India, vol. 42,1912, p. 208. 

 Zeitschr. Kryst. Min., vol. 10,1885, p. 433.
KOCK-FOKMIlsT G MINEBALS. 399

chlorite. Chloritic pseudomorphs are perhaps the most frequent.* 

The pyrope found in peridotite rocks is often surrounded by a zone 

or shell of altered material, to which A. Schrauf 2 has given the 

name kelyphite. It is, however, not a substance of uniform composition. The kelyphite studied by A. von Lasaulx 3 was mainly a 

mixture of pyroxenes and amphiboles. J. Mrha 4 described a kelyphite consisting of bronzite, monoclinie pyroxene, picotite, and hornblende. The pyrope from the peridotite dikes of Elliott County, 

Kentucky, described by J. S. Diller, 5 was surrounded by a similar 

shell made up of biotite and magnetite, with a little picotite. Biotite 

is not an uncommon derivative of the magnesian garnets. Garnet 

itself appears occasionally as an alteration product of other minerals. 

P. Jerome*ef 6 has recorded pseudomorphs of grossularite after vesuvianite; and grossularite after gehlenite was observed by A. Cathrein.7

VESWIANITE.

Tetragonal. Composition variable, and best represented by the 

general formula Al-jC^S^C^R',,; in which R'4 may be Ca2 , (A10H)2 , 

(A102H) 4 , or H4 . Some replacements of magnesium and iron are 

usually present; a little fluorine may be substituted for hydroxyl, and 

in the variety wiluite there is a small amount of boric oxide.8 Specific 

gravity, 3.35 to 3..45. Hardness, 6.5. Color, brown or green, sometimes yellow or pale blue. A massive variety of vesuvianite resembling jade has been called californite.

Vesuvianite has not yet been prepared synthetically. It is known 

chiefly as a product of contact metamorphism in limestones, associated with pyroxene, scapolite, garnet, wollastonite, and epidote. 

It is also found in some serpentines, chlorite schist, gneiss, etc. 

Pesudomorphs of grossularite after vesuvianite have been reported 

by P. Jereme*ef.8 When vesuvianite is fused, it breaks up into 

meionite, melilite, anorthite, and possibly a lime olivine. 10

THE SCAPOUTES.

Meionite. Tetragonal. Composition, Ca^Al^Si^Ogs. Molecular 

weight, 893.4. Specific gravity, 2.72. Molecular volume, 328.4. 

Colorless or white. Hardness, 5.5 to 6.

i See for example J. Lemberg, Zeitschr. Deutsch. geol. Gesell., vol. 27, 1875, p. 531, and S. L. Penflold 

and F. L. Sperry., Am. Jour. ScL, 3d ser., vol. 32,1886, p. 307.

* Zeitschr. Kryst. Min., vol. 6,1882, p. 35S.

»Verhandl. Naturhist. Ver. preuss. Rheinlancle u. Westfalens, vol. 39, pt. 2,1882, p. 114.

< Min. pet. Mitt., vol. 19,1899, p. 111.

» Bull. U. S. Geol. Survey No. 38,1887.

« Zeitschr. Kryst. Min., vol. 31,1899, p. 505.

» Min. pet. Mitt., vol. 8,1887, p. 400.

B See F. W. Clarke and G. Steiger, Bull. U. S. Geol. Survey No. 202,1905. For other interpretations of 

vesuvianite see P. Jaunasch and P. Weingarten, Zeitschr. anorg. Chemie, vol. 8,1895, p. 350; M. Weibull, 

Zeitschr. Kryst. Min., vol. 25,1895, p. 1; A. Kenngott, Neues Jahrb., Band 1,1891, p. 200; H. SjQgren, Geol. 

Foren. Forhandl., vol. 17,1895, p. 267.

» Zeitschr. Kryst. Min,, vol. 31,1899, p. 505. 

1° C. Doelter and E. Hussak, Neues Jahrb., 1884, Band 1, p. 158,
400 DATA OF GEOCHEMISTBY.

Marialite. Tetragonal. Composition, Na4Al3Si9024Cl. Molecular 

weight, 848.4. Specific gravity, 2.57. Molecular volume, 330.1. 

Colorless or white. Hardness, 5.5 to 6.

These two species, with their isomorphous mixtures, form the 

scapolite group as interpreted by G. Tschermak. 1 Intermediate 

between them, and analogous to the plagioclase feldspars lying 

between anorthite and albite, are the following scapolites, which have 

received independent names;

Wernerite........................................ MejMaj to Me^Ia^

Mizzonite or dipyre................................ MejMa2 to Me^la^

The reported syntheses of scapolite are not altogether conclusive. 

L. Bourgeois 2 attempted to prepare meionite by fusing together its 

constituent oxides, and obtained principally anorthite. By adding 

fragments of marble to a molten basaltic glass, however, he observed 

in one case the formation of crystals which were probably meionite. 

By fusing a leucitite with the fluorides of sodium and calcium, K. B. 

Schmutz 3 obtained an artifical rock containing scapolite; and a 

similar experiment with eclogite also yielded the mineral. The same 

procedure with epidote and fluorides gave C. Doelter 4 a product in 

which meionite was recognized. Doelter also reports the synthesis 

of meionite by fusion of the mixed oxides, lime, silica, and alumina; 

and by fusion of a silicate, CaAl2Si208 , with sodium chloride. His 

attempts to prepare marialite failed. E. S. Shepherd and G. A. 

Rankin 5 obtained meionite by heating a glass of that composition 

with a solution of sodium chloride in a bomb. They gave no details, 

however.

The scapolites occur principally in the crystalline schists, gneisses, 

amphibolites, and metamorphosed limestones. They are commonly 

products of metamorphic contact action and appear to be, as their 

composition would indicate, derived from plagioclase feldspar. They 

have been found as secondary minerals in various eruptive rocks.0 

In Norway scapolite rocks are associated with masses of apatite 

especially at Oedegaarden. In this instance J. W. Judd 7 has traced 

the development of the scapolite from plagioclase, and has ascribed 

the transformation partly to the action of sodium chloride solutions 

contained in cavities of the rock, and partly to powerful mechanical

i Min. pet. Milt., vol. 7, p. 400, 1SSO; Montash. Chcmie, vol. 4, 1883, p. 851. Compare F. W. Clarke's 

constitutional formulae in Bull. U. S. Geol. Survey No. 588,1914, p. 3C; and A. Himmclbauer, Sitzungsb. 

K. Akacl. Wiss. Wicn, 1910, Abth. 1, p. 119. A scapolite containing the sulphate radicle S0| has recently 

been described by R. Brauns, Neues Jahrb., Beil. Band 39, 1914, p. 121. It is named silvialite. Also 

scapolite containing carbonate groups by L. H. Borgstrom. Zeitschr. Kryst. Min., vol. 54,1914, p. 238.

» Annales chim. phys., 5th ser., vol. 29,1883, pp. 44C, 472.

a Neues Jahrb., 1897, vol. 2, pp. 133,149.

4 Idem, vol. 1, p. 1.

» Am. Jour. Sci., 4th scr., vol. 28, p. 305,1909.

« See F. Zirkel, Lehrbuch der Pctrographie, vol. 1,1893, p. 382. W. Salomon, Min. pet. Mitt., vol. 15, 

1895, p. 159, gives a good bibliography relative to dipyre

i Mineralog. Mag., vol. 8,1889, p. 186.
ROCK-FORMING MINERALS. 401

stresses. A. Lacroix, l however, regards the change as due to contact 

action between the rock and the apatite, although in other localities 

solutions of chlorides appear to be operative. Mechanical agencies 

are considered by Lacroix to be unimportant. At the Oedegaarden 

locality, which has been studied by several authorities, a granitic 

mixture of pyroxene and feldspar has been transformed into an 

aggregate of hornblende and scapolite. By fusion Fouque" and LeVy 2 

transformed it back again into pyroxene and labradorite. A Canadian 

scapolite diorite has been described by F. D.Adams and A. C. Lawson, 3 

and H. Lenk 4 has studied an augite-scapolite rock from Mexico.

The scapolites are exceedingly alterable, and most so toward the 

sodium or marialite end of the series. Many of the alteration products have been regarded as distinct species and have received independent names Pseudomorphs of mica, often in the form of'' pinite,'' 

after scapolite are very common. Alterations into epidote, steatite, 

kaolin, and free silica are also recorded. A. Cathrein 5 has reported 

pseudomorphs of scapolite after garnet.

IOLITE.

lolite or cordierite. Orthorhombic. Formula," H,(Mg,Fe) 4Al8Si10037 . 

Molecular weight and volume variable on account of variations between Mg and Fe. Specific gravity, 2.60 to 2.66. Color, blue, 

often smoky or grayish. Hardness, 7 to 7.5.

A possible synthesis of iolite was reported by L. Bourgeois, 7 who 

fused silica, magnesia, and alumina together in proper proportions. 

J. Morozewicz 8 also obtained it in his experiments upon artificial 

magmas, supersaturated with alumina, of the general formula 

R0.7ttAl203 .ttSi02 . When magnesia and iron were present and n 

was greater than 6, iolite was formed. In short, he produced an artificial cordierite-vitrophyrite, resembling the African rock described 

by G. A. F. Molengraaf.9 These syntheses, however, were made with 

anhydrous materials; and the product could not have been identical 

with the iolite of natural occurrences. All the trustworthy analyses 

of the mineral show that water is one of its essential constituents.

1 Bull. Soc. min., vol. 1-1,1891, p. 1G. In vol. 12,1SS9, p. S3, Lacroix has an elaborate monograph upon 

scapolite rocks.

2 Bull. Soc. min., vol. 2,1879, p. 112.

8 Canadian Rec. Sci., vol. 3,1888, p. 180.

< Neues Jahrb., 1899, Band 1, ref. 73. 

. & Zeitschr. Kryst. Min.. vol. 9,1884, p. 378; vol. 10,1SS5, p. 434.

o Formula based upon 0. C. Farrington's analysis, Am. Jour. Sci., 3d ser., vol. 43,1892, p. 13. M. Weibull 

(Geol. Foren. Forhandl., vol. 22, 1900, p. 33) regards the mineral as anhydrous, and writes the formula 

Mg2Al2(A10)2S6Oi6 .

' Annalcs chim. phys., 5th scr., vol. 29,1883, p. 4C2.

8 Min. pet. Mitt., vol. 18,1898, pp. 08,167. See ante, p. 333, under "Corundum." See also G. A. Rankin 

and H. E. Merwin (Am. Jour. Sci., 4th ser., vol. 43,1918, p. 301) for more precise data relative to the formation of iolite from a melt.

8 Neues Jahrb., Band 1,1894, p. 79.

113750° 19 Bull. 695 26
402 DATA OF GEOCHEMISTRY*

. lolite is found in nature in a^great variety of rocks, including both, 

metamorphic rocks and eruptiv.es. It has been reported in granite, 

quartz porphyry, basalt, quartz trachyte, biotite dacite, and andesite 

and seems to be a primary separation from the magmas.1 In order 

of deposition it follows biotite but precedes the feldspars. In cordierite gneiss and cordierite hornfels iolite is a characteristic constituent. The gneiss from Connecticut described by E. 0. Hovey 2 

consisted mainly of biotite, quartz, and iolite, with some plagioclase. 

lolite is also well known as a product of contact metamorphism. For 

example, Bucking 3 found it in sandstones which had been vitrified 

by contact with basalt; and Kikuchi 4 has described a Japanese 

locality where iolite occurs in slate at contact with granite.

lolite alters with great ease, taking up water and alkalies. The 

product is usually an impure mica, and many pseudomorphs of this 

character have received distinctive names. Chlorophyllite, praseolite, aspasiolite, gigantolite, fahlum'te, pinite, etc., are merely altered 

iolite.5

THE ZOISITE GROUP.

Zoisite. Orthorhombic. 6 Composition, HCa2Al3Si3013 . Molecular 

weight, 455.9. Specific gravity, 3.25 to 3.37. Molecular volume, 138. 

Color, white, gray, greenish, yellowish, reddish. Hardness, 6 to 6.5.

Epidote. Monoclinic. Composition like zoisite, but with varying 

replacements of Al by Fe. The variety with little or no iron has 

been called clinozoisite. Specific gravity, 3.25 to 3.5. Color, commonly green, yellowish or brownish green, to black, sometimes red, 

yellow, or gray; rarely colorless. Hardness, 6 to 7.

Piedmontite. Monoclinic. Composition like epidote, but with Mn 

replacing some Al and Fe. Specific gravity, 3.4. Color, reddish 

brown to black. Hardness, 6.5.

ATlanite or orthite. Monoclinic. Composition like epidote, but 

with cerium earths partly replacing alumina and iron. Specific gravity, 3.5 to 4.2. Color, brown to black. Hardness, 5.5 to 6.

The reported syntheses of zoisite and epidote are questionable, for 

the products seem to have contained no water. A. Brun 7 claimed to 

have produced zoisite by fusing 40 parts of silica with 37 of lime 

and 23 of alumina. C. Doelter,8 upon fusing epidote powder with

1 See H. Bucking, Ber. Senckenbergischen naturforsch. Gesell., Abliandl., 1900, p. 3; J. Szab<5, Neues 

Jahrb., Beil. Band 1,1SS1, p. 305; E. Hussak, Sitzungsb. K. Akad. Wiss. Wien, vol. 87, Abth. 1,1883, p. 332; 

Neues Jahrb., 1885, Band 2, p. 81; A. Harker, Geol. Mag., 1900, p. 17C.

2 Am. Jour. Sci., 3d ser., vol. 3C>, 1888, p. 57.

3 Loc. cit.

4 Jour. Coll. Sci. Japan, vol. 3,1890, p. 313. Kikuchi also describes an alteration of the iolite into pinite.

6 For a summary of these alterations see A. "Wichmann, Zeitschr. Deutsch. geol. Gesell., vol. 26,1874, 

p. 675. For the mechanism of the change from iolite to Chlorophyllite see F. W. Clarke, Ball. U. S. Geol. 

Survey No. 588,1914, p. 79.

« For optical variations in zoisite, see P. Termier, Bull. Soc. min., vol. 21,1898, p. 148; vol. 23,1900, p. 50. 

Termier regards the silicate HCaaR"'jSi30i3 as trimorphous.

' Arch. sci. phys. nat., 3d ser., vol. 25,1891, p. 239.

8 Neues Jahrb., 1897, Band 1, p. 1.
ROCK-FORMING MINERALS. 403

tHe fluorides of sodium and calcium, obtained indications of some 

recrystallization of the epidote, together with garnet, meionite, anorthite, olivine, and magnetite. Epidote fused alone gave anorthite 

and a lime augite. Satisfactory syntheses of the minerals forming 

this group are as yet to be made.

Zoisite is essentially a mineral of the crystalline schists, such as 

amphibolite, glaucophane schist, eclogite, etc. It is also found in 

some granites and in beds of sulphide ores. A secondary zoisite, 

derived from plagioclase and commonly Containing both minerals 

commingled, is known as saussurite and is common in gabbros. 1 It 

is not at all uniform in composition.

Epidote, like zoisite, is a mineral of the crystalline schists, although 

C. R. Keyes 2 has cited evidence to show that it is a primary mineral 

in certain granites of Maryland. It is there intergrown with allanite 

and was also observed inclosed in primary sphene. A. Michel-LeVy 3 

also regards the epidote of certain Pyrenean ophites as primary. 

It is also found, according to B. S. Butler,4 in dikes cutting soda 

granite porphyry in Shasta County, California. There are many 

other examples on record.

Epidote is common in gneisses, garnet rock, amphibolite, paragonite and glaucophane schists and the phyllites, and as a contact 

mineral in limestones. It is also common as a secondary mineral, 

derived from feldspars, pyroxene, amphibole, biotite, scapolite, and 

garnet, and is frequently associated with chlorite. When lime-bearing ferromagnesian minerals chloritize their lime goes to the production of epidote. An epidote-quartz rock derived from diabase has 

been called epidosyte.5

Piedmontite is much less abundant than zoisite or epidote and is 

mainly confined to the crystalline schists. It also occurs with iron 

ores and as a secondary mineral in eruptives. G. H. Williams 6 has 

reported piedmontite in a rhyolite from Pennsylvania and N. Yamasaki 7 has described a similar occurrence in Japan. Piedmontite is 

quite common in the crystalline schists of Japan,8 forming a piedmontite schist, and also associated with rocks containing chlorite or 

glaucophane.

1 Also in the greenstones of the Lake Superior region. See G. H. Williams, Bull. U. S. Geol. Survey No. 

62, 1890, where the process of saussuritization is discussed. Williams cites abundant references to the 

literature of the subject.

a Bull. Geol. Soc. America, vol. 4,1893, p. 305.

8 Bull. Soc. geol. France, 3d ser., vol. C, p. 161.

< Am. Jour. Sci., 4th ser., vol. 28,1909, p. 27. Butler gives many references to literature.

 For a discussion of this alteration, with references to literature, see A. Schenck, Doct. Diss., Bonn, 

1884. Williams, in Bull. U. S. Geol. Survey No. 62,1890, also discusses the process of epidotization somewhat fully.

 Am. Jour. Sci., 3d ser., vol. 46,1893, p. 50. This paper contains many references to literature. 

' Jour. Coll. Sci. Japan, vol. 9,1897, p. 117. 

B Seo B. Koto, idem, vol. 1,1887, p. 303.
404 DATA OF GEOCHEMISTRY.

Allanite is widely diffused as a primary accessory in many igneous 

rocks. J. P. Iddings and W. Cross,1 who have pointed out its importance, cite occurrences of allanite in gneiss, granite, quartz 

.porphyry, diorite, andesite, dacite,rhyolite, etc. W.H. Hobbs,2 studying the granite of Ilchester, Maryland, in which allanite and epidote 

are intergrown, has especially discussed the paragenesis of the two 

species. The same association of minerals has been reported by 

F. D. Adams,3 A. Lacroix,4 G. H. Williams,5 and others. In the 

granite of Pont Paul, France, allanite is sometimes enveloped by 

biotite.6 W. Mackie 7 has reported several occurrences of allanite 

in Scottish granites. Allanite is often much altered, yielding carbonates of the cerium group, together with earthy products of uncertain character.

TOPAZ.

Orthorhombic. Simplest empirical formula, Al2Si04F2 , but with 

part of the fluorine commonly replaced by hydroxyl.8 Molecular 

weight, 184.6. Specific gravity, 3.56. Molecular volume, 51.9. 

Color, white, yellow, greenish, bluish, and reddish. Hardness, 8. 

The true formula is probably three times that given above, with the 

molecular weight and volume correspondingly tripled.9

The synthesis of a product allied to topaz was early reported by 

A. Daubree, 10 who heated alumina in a current of silicon fluoride. It 

contained, however, too little fluorine, and varied in other respects 

from topaz. H. Sainte-Claire Deville,11 repeating the experiment, 

obtained no fluoriferous silicate. C. Friedel and E. Sarasin 12 claim to 

have prepared topaz by heating alumina, silica, water, and hydrofluosilicic acid together at 500°, but give no details nor analyses. A. 

Reich 13 subjected a mixture of silica and aluminum fluoride to a 

strong red heat, and afterward ignited the mixture thus obtained in a 

current of silicon fluoride. By this process topaz was formed, which 

was identified both crystallographically and by analysis. This is 

the only satisfactory synthesis of topaz so far recorded.

Topaz commonly occurs in gneiss or granite, and especially in tinbearing pegmatites. The rock from the tin mine at Mount Bischoff,

> Am. Jour. Sci., 3d ser., vol. 30,1885, p. 108.

* Idem, p. 108, vol. 38,1889, p. 223.

8 Canadian Rec. Sci., vol. 4,1891, p. 341.

* Bull. Soc. min., vol. 12,1889, pp. 138,157,210. 

6 Bull. U. S. Geol. Survey No. 62,1890.

e A. Michel-Le'vy and A. Lacroix, Bull. Soc. min., vol. 11, 1888, p. 65.

i Trans. Edinburgh Geol. Soc., vol. 9,1909, p. 216. A Canadian "granite," containing 56 per cent of 

allanite, is reported by G. C. Hoffmanu in Ann. Kept. Geol. Survey Canada, vol. 7, 1894, p. 12R. On 

the weathering of allanite see T. L. Watson, Bull. Geol. Soc. America, vol. 28,1917, p. 463. 

8 S. L. Penfield and J. C. Minor, Am. Jour. Sci., 3d ser., vol. 47,1894, p. 387.

" See F. W. Clarke and J. S. Diller, Bull. U. S. Geol. Survey No. 27,1886, and also Clarke, Bull. No. 588, 

1914.

10 Etudes synthe"tiques'de gdologie exp6rimentale, p. 57. 

" Compt. Rend., vol. 52,1861, p. 780. 

» Bull. Soc. min., vol. 10,1887, p. 169. 

«« Monatsh. Chemie, vol. 17,1896, p. 149.
BOCK-FOEMING MINERALS. 405

Tasmania, has been described by A. von Groddeck 1 as a porphyritic 

topazfels. The Brazilian topazes are found in decomposed material, 

which, according to 0. A. Derby,2 was probably a mica schist derived 

from an antecedent augite or nepheline syenite. In Colorado and 

Utah topaz occurs in lithophyses of rhyolite.3 Gaseous emanations 

containing fluorine probably play an important part in its development. Topaz alters easily, by hydration and by the action of percolating alkaline solutions, and is transformed into compact muscovite.4 

The reported alterations to steatite and serpentine are probably 

based upon erroneous diagnoses. By heating topaz with a solution 

of sodium silicate 174 hours at 200° to 210°, J. Lemberg 5 converted 

it into an alkaline alumo-silicate of presumably zeolitic character. 

At a white heat topaz loses fluorine and becomes transformed into 

sillimanite.6

THE ANDALTTSITE GROUP.

Andalusite. Orthorhombic. Simplest empirical formula, Al2Si05 ; 

true formula probably three times as great. Corresponding molecular 

weight, 162.6. Specific gravity, 3.18. Molecular volume, 51.1. 

Color, white, reddish, violet, brown, olive-green. Hardness, 7.5.

Sillimanite or fibrolite. Orthorhombic. Composition and lowest 

molecular weight the same as for andalusite. Specific gravity, 3.2. 

Molecular volume, 50.8. Color, grayish white, grayish brown, pale 

green, brown. Hardness, 6 to 7.

Kyanite or cyanite. Triclinic. Composition, etc., as with andalusite and sillimanite. Specific gravity, 3.6. Molecular volume, 45.2. 

Color, commonly blue, sometimes white, gray, or green. Hardness, 7.

These three minerals are of peculiar interest because of their identity in chemical composition. They undoubtedly differ in chemical 

structure, and kyanite possibly differs from the other two in molecular weight, but upon the latter point the evidence is not conclusive. 

Andalusite and sillimanite are commonly regarded as basic orthosilicates, and kyanite, on account of its greater resistance to the 

action of acids, has been interpreted by P. Groth as a metasilicate, 

(AlO) 2SiO3 . 7 In an interesting investigation by W. Vernadsky 8 

it is shown that both andalusite and kyanite are transformed into

1 Zeitschr. De'iitsch. geol. Gesell., vol. 36,1884, p. 642. On the topaz-bearing rocks of Gunong Bakau, 

Malay States,see J. B. Scrivener, Quart. Jour. Geol. Soc., vol. 70,1914, p. 363.

* Am. Jour. Sci.,4thser.,vol. 11,1901, p. 25.

 See W. Cross, idem, 3d ser., vol. 31,1886, p. 432.

« For a complete study of this alteration, see F. W. Clarke and J. S. Diller, Bull. U. S. Geol. Survey 

No. 27,1886. See also A. Atterberg, Geol. Foren Forhandl., vol. 2,1874-75, p. 402.

6 Zeitschr. Deutsch. geol. Gesell., vol. 40,1888, pp. 651 et seq. 

o W. Vernadsky, Bull. Soc. min., vol. 13,1890, pp. 259-260.

7 A different but not very plausible interpretation of these species has been oflercd by K. Zulkowski, 

Monatsb. Chemic, vol. 21,1900, p. 1086.

8 Bull. Soc. min., vol. 13,1890, p. 256; Compt. Rend., vol. 110,1890, p. 1377. For earlier syntheses of these 

minerals, by Daubrde, Deville and Caron, Frcmy and Feil, Meunier, and Hautcfeuillo and Margottet, see 

L. Bourgeois, Reproduction artificielle des mine'raux, pp. 119,120. The processes, except the last, involved 

the use of aluminum fluoride, silicon fluoride, or silicon chloride, and were therefore indirect.
406 DATA OF GEOCHEMISTRY.

sillimanite by simply heating to a temperature between 1,320° and 

1,380°. Sillimanite, therefore, is the most stable of the three species, 

at least under pyrogenic conditions. Vernadsky has identified it as 

an essential constituent of hard porcelain. He also obtained sillimanite by fusing silica and alumina together. This synthesis has 

also been effected by E. S. Shepherd and G. A. Rankin, 1 who find that 

sillimanite is the only one of the three silicates which is stable in the 

pure melt. They also confirm the statement that kyanite and 

andalusite pass into sillimanite when strongly heated. Their artificial sillimanite melted at 1,811°. A. Reich, 2 by heating aluminum 

fluoride with silica to strong redness, obtained a mixture of sillimanite and corundum. The conditions under which sillimanite can 

form magmatically have also been determined by J. Morozewicz.3 

In the magmatic mixture RO.raAl2 03 .?7Si02 , if magnesia and iron 

are absent, m=l, and n is greater than 6, sillimanite is developed. 

K. Dalmer 4 has reported the alteration of a chlorite-mica phyllite 

into a mixture of andalusite and biotite.

Andalusite is a mineral of the metamorphic schists, and is especially common in the contact zones of clay slate near dikes of granite 

or diorite. It is also found in Archean gneiss and mica schist, and 

sometimes as an accessory in granite. In the Inyo Range, California, 

A. Knopf 5 found a large body of rock consisting almost entirely of 

massive andalusite.

Sillimanite is common in the crystalline schists, particularly in 

feldspathic gneiss, and in cordierite gneiss. It is often found intergrown with quartz.

Kyanite also occurs in crystalline schists, such as gneiss, mica 

schist, paragonite schist, and eclogite. It is often embedded in 

quartz, and has been reported in limestone.6

Andalusite alters to muscovite, 7 and sometimes also to chlorite and 

kaolin.8 J. Lemberg, 9 by heating andalusite or kyanite with alkaline 

silicates or carbonates under pressure, converted them into zeolitic 

substances. C. Doelter,10 upon heating andalusite with potassium 

carbonate and fluoride during several weeks at 250°, observed the 

formation of scales of mica.

It has already been stated that the empirical formulae for topaz 

and andalusite should probably be tripled, a suggestion which is

1 Am. Jour. Sci., 4th ser., vol. 23,1900, p. 293. See also W. Eitel, Zeitschr. anorg. Cbem., vol. 88,1914, 

p. 173.

2 Monatsh. Chemie, vol. 17,1896, p. 190.

3 Min. pet. Mitt., vol. 18,1898, p. 72. 

< Neues Jahrb., 1897, Band 2, p. 156. 

6 Jour. Washington Acad. Sci., vol. 7,1917, p. 549. 

«J. Kovaf, Zeitschr. Kryst. Min., vol. 34,1901, p. 704. 

. i A. Graxnann, Neues Jahrb., Bd. 2,1901, p. 193. 

s P. E. Haefele, Zeitschr. Kryst. Min., vol. 23,1894, p. 651.

»Zeitschr. Deutsch. geol. Gesell., vol. 40,1888, p. 651. >. 

» Allgemeine chemische Mineralogie, p. 207.
ROCK-FORMING MINERALS. 407

based partly upon their alterability into muscovite. On this basis 

the three species compare as follows:

Andalusite....................................... Al3(Si04)3(A10)3 .

Topaz............................................. Al3(Si04 )3(AlF;j)3 .

Muscovite......................................... Al 3 (Si04 )3KH2 .

STATJROLITE.

Orthorhombic. Composition, HFeAl5Si2O13J 1 with a little magnesia or sometimes manganese oxide replacing a part of the iron. 

Molecular weight, 457.2. Specific gravity, 3.7. Molecular volume, 

123. Color, brown to black. Hardness, 7 to 7.5.

No authentic synthesis of staurolite has yet been recorded. The 

substance obtained by H. Sainte-Claire Deville and H. Caron 2 by 

the action of silicon fluoride upon a heated mixture of alumina and 

quartz, and called staurolite by them, had nearly the composition 

of sillimanite.3 P. Hautefeuille and J. Margottet,4 in their memoir 

upon the synthesis of certain phosphates, also mention the production of a mineral resembling staurolite but give no further details.

Staurolite is a mineral of the metamorphic schists, especially of 

muscovite or paragonite schist, and some gneisses or slates. It is 

often associated with kyanite. Staurolite alters into muscovite.5 

The reported alteration into steatite is very questionable.

LAWSONITE.

Orthorhombic. Composition, H4CaAl2Si2O10. Molecular weight, 

315.1. Specific gravity, 3.09. Molecular volume, 102. Color, pale 

blue to grayish blue. Hardness, 8.25.

Lawsonite was discovered by F. L. Ransome 6 in 1895, in a glaucophane-bearing schist from Tiburon Peninsula, California. It has 

since been found by S. Franchi and A. Stella 7 in the metamorphic 

schists of the Alps; by C. Viola 8 in the saussuritized gabbros of 

southern Italy; and by A. Lacroix ° in similar rocks and glaucophane schists from Corsica and New Caledonia. J. P. Smith 10 has 

recently described lawsonite rocks from several localities in California, especially a lawsonite-glaucophane schist and a lawsoniteglaucophane gneiss. The latter rock carried about 25 per cent of

1 Established by S. L. Pehfleld and J. H. Pratt, Am. Jour. Sci., 3d ser., vol. 47,1894, p. 81.

2 Compt. Rend., vol. 46,1858, p. 764.

« H. Sainte-Claire Deville, idem, vol. 52,1861, p. 780.

< Idem, vol. 96,1883, p. 1052.

» See analysis in Bull. U. S. Geol. Survey No. 220,1903, p. 54.

 Bull. Dept. Geology Univ. California, vol. 1, 1895, p. 301. See also F. L. Ransome and C. Palache, 

Zeitschr. Kryst. Mia., vol. 25,1896, p. 531; and W. T. Sohaller and W. F. Hillebraad, Bull. U. S. Geol. 

Survey No. 262,1905, p. 58.

' Cited by P. Termier, Bull. Soc. min., vol. 20,1897, p. 5. See also Termier, idem, vol. 27, 1904, p. 265.

s Zeitschr. Kryst. Min., vol. 28,1897, p. 553.

» Bull. Soc. min., vol. 20,1897, p. 309.

»o Proc. Am. Philos. Soc. vol. 45,1907, p. 183-. See also A. S. Eakle, Bull. Dept. Geology Univ. California, vol. 5,1907, p. 82.
408 DATA OF GEOCHEMISTRY.

 lawsonite. The mineral is evidently of widespread occurrence. Its 

formula suggests a derivation from anorthite, by assumption of two 

molecules of water. .Upon.fusion, lawsonite would undoubtedly yield 

anorthite.

According to F. Gornu, 1 the compound H4CaAl2Si2 09 is dimorphous. Lawsonite is one modification; the other, isometric, he has 

named hibschite. It was found enveloping garnet as an inclusion 

in the phonolite of Aussig, Bohemia.

DTTMORTIERITE.

Orthorhombic. Composition, Al8HBSi3020 . 2 Molecular weight, 

634. Specific gravity, 3.3. Molecular volume, 192. Color, blue, 

bluish green, rose, lavender, or black. Hardness, 7.

Dumortierite was originally discovered in a pegmatite gneiss near 

Lyons, in France. It has since been found in Germany, Austria, 

Norway, Argentina, and at several localities in the United States.3 

It has been observed in pegmatite, in cordierite gneiss, 4 in granite, 

and in certain quartz rocks associated with kyanite (Arizona), sillimanite (California), and andalusite (Washington). Muscovite is 

also one of its companions, and Schaller has observed its alteration 

into muscovite. In Humboldt County, Nevada, A. Knopf 5 discovered 

a rock consisting largely of dumortierite and quartz. It covered a 

large area, and the dumortierite ranged from blue to a rich rose in 

color. Dumortierite as a rule, however, is an inconspicuous mineral, 

except for its usual bright-blue color, and is probably not at all rare. 

Its close relationship to andalusite, sillimanite, and kyanite is obvious. 

According to W. Vernadsky, 6 dumortierite, at a white heat, is converted into sillimanite. What other product is formed at the same 

time is not stated. 7

TOURMALINE.

Rhombohedral. Composition, a complex borosilicate of aluminum 

and other bases. Color, white, yellow, brown, green, red, blue, and 

black. Specific gravity, 2.98 to 3.20. Hardness, 7 to 7.5.

Tourmaline really represents a group of isomorphous species, whose 

chemical relations are not yet completely understood. There are, 

however, three distinct types, as follows:

1 Min. pet. Mitt., vol. 25,1906, p. 249.

2 As determined by W. T. Schaller, Bull. U. S. Geol. Survey No. 262,1905, pp. 91-120. See also AV. E. 

Ford, Am. Jour. Sci., 4th ser., vol. 4,1902, p. 426. Ford's formula diflcrs slightly from Schallcr's.

8 See Schaller's memoir, cited above, for a full summary of the known localities and a bibliography of 

the species.

«See A. Lacroix, Bull. Soc. min., vol. 12,1SS9, p. 211.

* Private communication.

" Bull. Soc. min., vol. 13,1890, p. 256.

' G. I. Finlay (Jour. Geology, vol. 15,1907, p. 479) reports dnmortierite and corundum as original'pyrogenic constituents of a pegmatite dike near Canon City, Colorado.
ROCK-FORMING MINERALS. 409

Alkali tourmaline: Contains lithium or sodium, sometimes potassium in less amount. Found in pegmatites, with muscovite and 

lepidolite.

Magnesium tourmaline: Chief base, after aluminum, magnesium. 

Often found in limestone or dolomite, with phlogopite as the accompanying mica.

Iron tourmaline: The common black variety, which alone is significant as a rock-making mineral. Contains iron in place of magnesium. Associated commonly with muscovite or biotite.

Between these distinct types there are various intermediate mixtures, and also rare examples in which a little chromium appears, 

partly replacing aluminum.

Over the chemical formula of tourmaline there has been much discussion, and no set of expressions can be assumed as final. 1 The 

following formulas seem to be best sustained by evidence: 2

(1) Al8R/5Si6B3031 .

(2) Al7R'8Si0B3031 .

(3) Al 5R'HSi6B3031 .

In No. 3 the R' is largely replaced by R", which may be Fe or Mg. 

Hydrogen is important among the components of R/. Fluorine is 

also commonly present in small amounts. The general formula 

AlgR^BOH^SiAo, proposed by S. L. Penficld and H. W. Foote, 3 

is preferred by some authorities.

Tourmaline has not as yet been produced synthetically. The rockforming iron-bearing variety is commonly found in the older and more 

highly siliceous igneous and granular rocks, such as granite, syenite, 

and diorite. It is also abundant in mica schists, clay slates, and 

other similar matrices. It forms in some cases at the contact between 

schists and granite, and may be abundant enough to characterize an 

occurrence as a tourmaline hornstone. In igneous rocks it seems to 

have been produced by fumarole action, and not as a direct separation 

from the magma. H. B. Patton 4 regards the tourmaline of certain 

schists in Colorado as having been formed at the expense of the biotite contained in the pegmatites adjoining the contact zone.

Tourmaline alters to mica, chlorite, and cookeite. Upon fusion, 

according to C. Doelter, 5 tourmaline yields olivine and spinel.

1 See C. Rammelsberg, Neues Jahrb., 1890, Band 2, p. 149. A. Kenngott, idem, 1892, Band 2, p. 44. 

G. Tschermak, Min. pet. Mitt., vol. 19,1899, p. 155; Zeitschr. Kryst. Min., vol. 35,1899, p. 206. V. Goldschmidt, Zeitschr. Kryst. Min., vol. 17, 1890, pp. 52, 61. R. Scharizer, idem, vol. 15,1889, p. 337. PI. 

Jannasch and G. Calb, Ber. Deutsch. chem. Gesell., vol. 22,1889, p. 216. H. Rheineck, Zeitschr. Kryst. 

Min., vol. 17,1890,p.604; vol.22,1894,p.52. ]<:. A. Wulfing,Min.pet.Mitt.,vol.lO,lS8S,p.l61; P. Reiner, 

Inaug. Diss. Heidelberg, 1913; W. T. Schaller, Zeitschr. Kryst. Min., vol. 51, p. 321,1913.

* Bull. U. S. Geol. Survey No. 167,1900, p.26;. Am. Jour. Sci.,4th ser., vol. 8,1899, p. 111. Also in Bull. 

U. S. Geol.Survey No. 588,1914.

a Am. Jour. Sci.,4thser., vol. 7,1899, p. 97; vol. 10,1900, p. 19.

< Bull. Geol. Soc. America, vol. 10,1898, p. 21.

s Neues Jahrb., 1897, Baud 1, p. 1.
410 DATA Or GEOCHEMISTRY.

BERYL.

Hexagonal. Normal composition, Al2Gl3Si6018. Molecular weight, 

539.9. Specific gravity, 2.7. Molecular volume, 200. Colorless, 

white, more commonly green, sometimes yellow, blue, or rose. Hardness, 7.5 to 8.

Although normal beryl has the composition given above, the mineral generally varies from it. S. L. Penfield* has shown that many 

beryls contain alkalies, replacing glucina, and also some combined 

water, up to nearly 3 per cent. A beryl from Hebron, Maine, contained 3.60 per cent of Cs20. A beryl analyzed by J. S. De Benneville 2 carried 2.76 per cent of K^O; and F. C. Robinson,3 in another 

example, found 2.76 per cent of P205 .

J. J. Ebelmen 4 succeeded in recrystallizing beryl by fusion with 

boric oxide. P. Hautefeuille and A. Perrey 5 obtained it in crystals 

by fusing a mixture of alumina, glucina, and silica with the same 

flux. H. Traube6 precipitated a solution containing aluminum sulphate and glucinum sulphate with sodium metasilicate, and crystallized the product from fused boric oxide in the same way. In both 

of the cases just cited, the beryl obtained was identified crystallographically and by analysis.

Beryl is a common accessory in pegmatite veins. It is also found 

in clay slate and mica schist. It alters into mica and kaolin, when 

the removed glucina generally appears as a constituent of other 

secondary minerals, such as bertrandite, herderite, or beryllonite. 

Although beryl is not commonly included by petrographers in their 

lists of rock-forming minerals, it seems entitled to recognition in a 

chapter of this kind.

SERPENTINE, TALC, AND KAOLINITE. ' . '

Serpentine. Optically monoclinic, but not known in true crystals. 

Composition, H4Mg3Si209 . Molecular weight, 278. Specific gravity, 2.5 to 2.6. Molecular volume. 109. Color commonly green, 

often yellowish.

Hydrous magnesian silicates are easily prepared by various wet 

reactions, but these syntheses have little or no significance in the 

interpretation of serpentine.7 The mineral occurs in nature only as 

a secondary product, derived by hydrous alteration from olivine, 

hornblende, actinolite, enstatite, diopside, chondrodite, and other 

magnesian minerals. Large rock masses are frequently found which

1 Am. Jour.S(!i.,3dser.,vol.28,1884,p.25; vol.36,1888,p.317.

2 Jour. Am. Chem. Soc.,vol,16,1894, p. 65.

s Jour. Anal, and Appl. Chem., vol. 6,1892, p. 510.

« Annaleschim.phys.,8dser.,vol.22,1848,p.237. .

6 Compt. Rend., vol. 106,1888, p. 1800.

aNeues Jahrb.,1894, Band 1, p. 275.

i See, for example, A. Gages, Kept. Brit. Assoc., 1863, p. 203. Gage's product resembled dewejUte.
ROCK-FORMING MINERALS. 411

have become transformed into impure serpentine. Gabbro, 1 peridotite,2 and amphibolite 3 may undergo this change.4 The alterative 

process, however, does not end here. Serpentine itself may undergo 

further alteration, yielding brucite, magnesite, hydromagnesite, etc. 

R. Brauns 5 has described a derivative of serpentine, which he calls 

webskyite, H6Mg4Si3013 .6H2 0; and F. W. Clarke 6 has reported an 

apparent serpentine which proved upon analysis to be nearly 60 per 

cent brucite. By solfataric action serpentine may lose its magnesia 

in the forms of sulphate or carbonate and become transformed into a 

mass of quartz and opal.7 When serpentine is fused it yields a. mixture of olivine and enstatite.8

Talc. Monoclinic. Composition, H2Mg3Si4012 . Molecular weight, 

380.8. Specific gravity, 2.7 to 2.8. Molecular volume, 138. Color, 

white to green. The name talc is commonly applied to the foliated 

varieties; the massive mineral is called steatite.

Talc is common as a pseudomorphous mineral, derived from other 

magnesian species, often from tremolite or enstatite.9 Assuming the 

change to be brought about by carbonated water, the reactions may 

be simply written as follows:

CaMg3SiA-> +H2O + CO2 = Ii,Mg3Si4O12 +CaC03 . 

Mg4Si4O;2 +H2O +CO2 = H2Mg3Si4Ol2 +MgC03 .

The talc thus produced is not infrequently associated with marble 

or dolomite. The most important occurrence of talc, however, from 

a geological point of view, is in the form of talcose schist.

According to F. A. Genth, talc may alter into anthophyllite.10 

When talc is ignited, it loses water, and one-fourth of the silica is 

split off in the free state.11 The residue after removing the liberated 

silica, has the composition MgSi03 .

A number of other hydrous magnesian silicates occur as secondary 

minerals, such as deweylite, saponite, etc.; but they are geologically 

unimportant.

Kaolinite. Monoclinic. Composition, H4Al2Si2O9. Molecular 

weight, 259. Specific gravity, 2.6. Molecular volume, 99.6. Color, 

white, often tinted by impurities.

1 See L. Finckh, Zeitschr. Deutsch. geol. Gesell., vol. 50,1898, p. 108.

2 See G. H. Williams, Am. Jour. Sci., 3d ser., vol. 34,1887, p. 137.

' See J. H. Jaquet, Rec. Geol. Survey New South Wales, vol. 5,1905, p. 18.

' For general discussion overthe origin of serpentine, see G. F. Becker, Mon. U.S. Geol. Survey, vol. 13, 

1888, pp. 108 et seq.; and J. J. H. Teall, British petrography. The literature is very abundant.

6 Neues Jahrb.,Beil. Band 5,1887, p. 318. Brauns discusses the different varieties of serpentine fully and 

cites much literature.

 Bull. U. S. Geol. Survey No. 262,1905,p.69.

' See G. F. Becker, Mon. U. S. Geol. Survey, vol. 13,1888, pp. 108 et seq.; also A. Lacroix, Compt. Rend, j 

VOl.124,1897,p. 513.

8 Daubre"e; see ante, p. 372, under Enstatite.

» See C. H. Smyth, School of Mines Quart., vol. 17,189G, p. 333, and J. H. Pratt, North Carolina Geol. 

Survey, Economic Paper No. 3. 

10 Proc. Am. Philos. Soc., vol. 20,1882, p. 381. 

» F. W. Clarke and E. A. Schneider, Bull. U. S. Geol. Survey No. 78, 1891, p. 13.
412 DATA OF GEOCHEMISTRY.

Known only as a secondary mineral, the product of hydrous alteration of other species. Derived chiefly from feldspars.

Halloysite, cimolite, newtonite, montmorillonite, pyrophyllite, and 

allophane are other hydrous silicates of aluminum. They need no 

consideration here.

THE ZEOLITES.

Under the general term zeolites are included a number of important minerals, which, however, do not strictly belong to the rockmaking class. They occur in eruptive rocks only as secondary products, except in the noteworthy case of analcite, which has already 

been described. The more important zeolites are the following:

Heulandite. ..................................... CaAl 2Si6016 .5H20.

Laumontite. .................................... CaAl2Si4012 .4H20.

Chabazite. ....................................... CaAl2Si 4012 .6H20.

Thomsonite. .................................... CaAl2Si208 .2£H20.

Scolecite. ....................................... CaAl2Si3010 .3H20.

Natrolite.. ....... ............................. . .Na2AL,Si3010 .2H20.

Hydronephelite.. . ............................. . .HNa2Al 3Si3012,3H20.

To these may be added ptilolite, mordenite, brewsterite, epistilbite, 

phillipsite, gismondite, laubanite, gmelinite, 'leyynite, faujasite, 

edingtonite, mesolite, erionite, wellsite, and perhaps other species. As 

a rule, in the lime-bearing zeolites a part of the lime may be replaced 

by other bases, generally by soda. Potassium, however, is found in 

notable quantities in phillipsite, harmotome, edingtonite, and wellsite, and strontium in brewsterite and wellsite. The formulas given 

above are general and empirical, nothing more; but they suggest 

some paragenetic relations. Stilbite and heulandite seem, for example, to be derivatives of an unknown calcium-albite; and in general 

the zeolites appear to have been formed from feldspars or feldspathoids. Anorthite and nephelite are common parents of zeolitic 

minerals. Pectolite, okenite, gyrolite, and apophyllite 1 are other 

secondary minerals whose mode of occurrence is like that of the true 

zeolites, and possibly the species prehnite and datolite should on 

genetic grounds be grouped with them. Mineralogically these minerals are classed elsewhere ; it is only as regards their mode of formation that they are mentioned now.

Many syntheses of zeolites and zeolitic compounds are recorded, 

and several species have been recrystallized from solution in superheated waters. The syntheses were necessarily effected by hydrochemical reactions, either operating upon such minerals as anorthite 

or nephelite, or by double decomposition between aqueous solutions. 

H. Sainte-Claire Deville,2 for example, produced phillipsite, levyn1 On apophyllite as a rock-forming mineral, see F. Cornu, Centralbl. Min. , Geol. u. Pal. , 1907, p. 239. See 

also J. E. Hibsch (Min. pet. Mitt., vol. 33, 1915, p. 340) on primary zeolites.

2 Compt. Rend., vol. 54, 1862, p. 324.
BOCK-FOEMING MINEKALS. 413

ite, and gmelinite by heating solutions of potassium silicate with 

sodium or potassium aluminate to 170°. C. Doelter * prepared apophyllite, okenite, chabazite, heulandite, stilbite, laumontite, thomsonite, 

natrolite, and scolecite by various processes; and J. Lemberg 2 has 

shown that zeolites can be generated from one another by the action 

at moderately high temperatures of suitable reagents, such as the 

alkaline carbonates and silicates. The syntheses of analcite by De 

Schulten and Friedel and Sarasin have already been described.3 At 

the hot springs of Plombie'res A. Daubre*e 4 found zeolites which had 

been produced by the action of the percolating waters upon the 

cement and brick work of the old Roman baths. Chabazite, phillipsite, apophyllite, and gismondite were identified, and similar developments were afterward discovered at other hot springs in France and 

Algeria.5

High temperatures, however, are not essential to the formation of 

zeolites. Phillipsite has been found abundantly in volcanic mud 

dredged up from the bottom of the Pacific Ocean; 6 and A. Lacroix 7 

discovered several of the species under conditions which showed a 

recent origin from cold percolating waters.8

THE CARBONATES.

Calcite. Rhombohedral. Composition, CaC03 . Molecular weight, 

100.1. Specific gravity, 2.72. Molecular volume, 36.8. Hardness, 

3. Normally colorless, but often variously colored by impurities.

Aragonite. Orthorhombic. Composition, CaC03 , like calcite. 

Specific gravity, 2.94. Molecular volume, 34. Hardness, 3.5 to 4. 

Color, white, but often tinted by impurities.

Dolomite. Rhombohedral. Composition, CaMgC2 06 . Molecular 

weight, 184.5. Specific gravity, 2.83. Molecular volume, 65.2. 

Hardness, 3.5 to 4. Normally colorless but often tinted pink or 

brown.

Magnesite. Rhombohedral. Composition, MgC03 . Molecular 

weight, 84.4. Specific gravity, 3.0. Molecular volume, 28.1. Hardness, 3.5 to 4.5. Color, white to brown.

Siderite. Rhombohedral. Composition, FeC03 . Molecular weight, 

115.9. Specific gravity, 3.88. Molecular volume, 29.9. Hardness, 

3.5 to 4. Color, gray to brown, sometimes white. Breunnerite and

> Neues Jahrb., 1890, Band 1, p. 118.

2 Zeitschr. Deutsch. geol. Gesell., vol. 28, 1876, p. 519. On artificial zeolites sec also F. Singer, Diss., 

Tech. Hochschule, Berlin, 1910. 

a See ante, p. 369.

 Etudes synthe'tic;ues de geologic expdrimentale, p. 179.

 Idem, p. 199.

o Challenger Kept., Narrative, vol. 1, pt. 2,1885, pp. 774, 815.

' Compt. Rend., vol. 123, 1896, p. 761. The localities described are in the Pyrenees. Plagioclase and 

scapolite were the parent minerals.

8 For a discussion of the constitution of the zeolites see F. W. Clarke, Bull. 17. S. Geol. Survey No. 5S8, 

1914, pp. 40-50.
414 DATA OF GEOCHEMISTRY.

mesitite are carbonates intermediate in composition between siderite 

and magnesite.

All these carbonates occur in igneous rocks as secondary or alteration products. Calcite is sometimes apparently of primary origin, 

but not certainly so. When heated under ordinary conditions, calcite dissociates into CaO+C02 ; but under great pressures it may be 

fused without decomposition. It is not impossible, therefore, that it 

may have formed in some cases during the solidification of a magma 

at great depth. 1

Calcite alone, as a rock, is represented by marble, limestone, chalk, 

etc., and is therefore a most important mineral. Dolomite also forms 

extensive rock masses. Both species will be more fully considered 

later in the study of sedimentary rocks.

i For examples of primary calcite in igneous rocks see F. D. Adams, Am. Jour. Sci., 3d ser., vol. 48,1894, 

p. 14; T. L. Walker, Quart. Jour. Geol. Soc., vol. 53,1897, p. 55; T. H. Holland, Mem. Geol. Survey India, 

vol. 30,1901, p. 197; 0. Stutzer, Centralbl. Min., Geol. u. Pal., 1910, p. 433; Rachel Workman, Geol. Mag., 

1911, p. 193. Many other examples are on record. The occurrences are principally in granite or neplieline 

syenite.
CHAPTER XL

IGNEOUS KOCKS. 

PRELIMINARY CONSIDERATIONS.

When a magma solidifies to form a rock, it may become either that 

indeterminate substance known as glass or a mixture of definite mineral species. Between these two stages of development any intermediate phase may be produced, from a glass containing a few individualized crystals or microlites to a mass of crystalline matter with 

some vitreous remainder. The character of the product will depend 

upon a variety of conditions, such as tho composition of the molten 

material, the rate of cooling, and the circumstances under which it 

cools. If solidification takes place at the surface of the earth, as in 

an ordinary volcanic outflow, one set of consequences will follow; if 

it is effected under pressure that is at great depth the gaseous 

contents of the magma, being unable to escape, will play a part in the 

process, and determine the formation of compounds which could not 

otherwise be generated. In either case a relatively small number of 

these will form in preponderating quantities. If we consider the 

igneous rocks statistically, we shall find that in the average they 

contain the following minerals:

Feldspars....................... :............................... 59.5

Hornblende and pyroxene..................................... 16.8

Quartz......................................................... 12.0

Biotite........................................................ 3.8

Titanium minerals.............................................. 1.5

Apatite....................................................... .6

94.2

The less abundant rock-forming minerals will make up the remaining 5.8 per cent.1 The computation is by no means exact, but it 

serves to illustrate the relative importance of the several groups or 

species. Feldspars predominate, the ferromagnesian minerals come 

next in abundance, then quartz, and after that all other species as 

minor accessories. This statement, it must be borne in mind, deals 

with averages only. Individual rocks may contain some of the less 

frequent minerals as principal constituents, such as olivine in the 

peridotites, nepheline or leucite in certain syenites or basalts, and so 

on. The moment we begin to study rocks separately we shall see 

that they vary widely from the mean.

' A somewhat different estimate is given by H. S. Washington in Prof. Paper U. S. Geol. Survey No. 14, 

1003. p. 155. Its general purport is. however, much the same as mine.

415
416 DATA OF GEOCHEMISTRY.

Being mixtures, the igneous rocks represent an almost infinite 

range of composition. The minerals which are capable of simultaneous generation from a magma may be commingled in various 

proportions. Rocks, therefore, are not sharply classifiable upon the 

basis of their composition, for they shade into one another through 

all possible gradations, and are separable by no precise dividing lines. 

A mineral is a distinct stoichiometric compound; a rock, except when 

it happens to consist of one mineral alone, is not. Mineralogically 

a rock may be quartz, or olivine, or hornblende, or pyroxene, with 

very little impurity; but these are the exceptional cases. Mixtures 

of two or more components, in variable proportions, form the rule. 

. Certain mixtures, however, are much more common than others 

and are represented by widely diffused and abundant rock types. 

Granite, for example, is a mixture of quartz and feldspar, with subordinate ferromagnesian minerals, and samples from different parts 

of the world are surprisingly similar.1 Absolute identity is, of course, 

out of the question; but the approximation to it is close enough to 

mark out what we may regard as a good rock species. Upon uniformities of this kind the prevalent classifications of the igneous 

rocks are based. The more frequent mixtures form the familiar 

types, and under them there appear an infinite number of varieties, 

representing minor differences of composition, intermediate forms, 

modes of occurrence, textures, genetic relationships, or even geologic 

age. With some of these criteria we have no present concern; only 

the chemical aspects of rock classification fall within the scope of this 

work. Other considerations have much weight, of course, but it is 

not the province of the chemist to discuss them.

CLASSIFICATION.

From a chemical point of view the igneous rocks may be classified 

in three different ways. First, on the basis of their ultimate composition. Second, by their proximate units, the minerals which they 

contain. The latter procedure is at present most in vogue, but the 

first method has strong advocates and may possibly prevail. In the 

third place we can start from the conception of a magma as a solution and regard the eutectic mixtures as the definite types with which 

the igneous rocks shall be compared. Let us consider the three 

propositions separately.

At first sight the mineralogical classification, a classification by the 

compounds which a rock actually contains, would seem to be the 

simplest and most reasonable. In practice, however, it is beset with

i In R. A. Daly's paper on the average composition of igneous rock types, Proc. Am. Acad., vol. 45,1910, 

p. 211, the clustering of analyses around "center-points" is strongly emphasized. For the average specific 

gravity of rocks, considered group by group, see P. Becke, Sitzungsb. K. Akad. Wiss. Wien, vol. 120, Abth. 

I, p. 265,1911. The average specific gravity of 958 igneous rocks, computed by F. W. Clarke, is 2.737.
IGNEOUS ROCKS. 41-7

difficulties. A perfectly fresh, unaltered, entirely crystalline rock is 

easy to describe on this basis; but all rocks do not fulfill these conditions. In some rocks the mineralogical development is obscure, so 

that essential constituents can not be clearly defined. In others the 

development is incomplete, a certain amount of undifferentiated glass 

remaining to complicate the problem. We can infer in such cases 

what minerals should form if the de vitrify ing process were ended; 

but our inferences may not be conclusive. In some instances supposed glass has proved to be analcite, and misapprehensions of that 

order are not easily avoided. This objection, of course, carries little 

weight, for any classification is liable to be influenced by errors of 

diagnosis. Only, other things being equal, that classification is best 

in which the liabilities to error are fewest. The fundamental difficulty of all is inherent in the nature of our problem; for in dealing 

with mixtures it is not easy to establish dividing lines, and to decide 

on which side of an imaginary boundary a given rock should be 

placed. This difficulty, which chiefly affects our judgment in dealing 

with intermediate forms, exists in all rock classifications. It can only 

be overcome by conventional devices, which must be more or loss 

arbitrary.

Some of the difficulties which obstruct a mineralogical classification 

are avoided by the purely chemical system. The latter rests upon 

supposedly good analyses of rocks, and the molecular ratios deduced 

from the analytical data are the ultimate criteria. Good analyses are 

easily obtained; their discussion involves no questionable hypotheses, 

and their classification is comparatively simple.1 But is a classification of analyses a classification of rocks ? That question needs to 

be considered very carefully.

In the first place a rock mass may be a perfectly definite petrographic unit and yet not be homogeneous. In fact, the presence of 

separately distinguishable minerals in it is evidence of heterogeneity. 

Suppose, now, that two analysts, equally competent, receive samples 

of a given rock taken from the same quarry by two different collectors. In one sample the phenocrysts of a certain mineral are a 

little more numerous or a little larger than in the other. The two 

analyses will therefore diverge, and the same rock, because of their 

dissimilarities, may be classified under two distinct headings. Evidently, in such a case, something more than analysis is needed in 

order to define the nature of the substance under examination. 

Chemically at least the nature of the substance is the essential thing 

to be determined; and therefore both chemical and mineralogical evidence must be taken into account together. According to its nature 

the substance is to be classified.

» Such a classiflcation has been proposed by H. Warth, Geol. Mag., 1900, p. 131, and elaborated in I'roc. 

Roy. Soc. Edinburgh, vol. 28,1907, p. 85.

113750° 19 Bull. 695 27
418 DATA OF GEOCHEMISTRY.

The interdependence of the two schemes of classification can be 

brought out in still another way. It is a commonplace of chemistry 

that two or even many substances may have absolutely the same 

percentage composition and yet be very different in their molecular 

structure and physical properties. Methyl oxide, for instance, is a 

gas; ethyl alcohol is a liquid; and yet both compounds are accurately represented by the same empirical formula, C2H60. Nor is 

this an exceptional case, for organic chemistry takes cognizance of 

similar examples by the thousand. The differences are ascribed to 

different arrangements of the atoms within the molecule, and the 

substances which exhibit this empirical identity are said to be 

isomeric.

Similar instances, although not so sharply defined, and by no 

means so clearly interpreted, are found in mineralogy. The pyroxenes 

and amphiboles, for example, have in general the same molecular 

ratios, while enstatite and anthophyllite are alike in ultimate composition. Amphiboles, by fusion alone, are transformable into pyroxenes, and the reverse change takes place when pyroxene is altered into 

uralite. Two rocks, then, alike in composition as shown by analysis, 

and jnagmatically identical, may be quite different mineralogically, 

the one containing amphibole and the other pyroxene.1 Analytical 

data will lead us to class them, together; mineralogical considerations 

place them apart. This is a simple case, but as rocks become more 

complex, the chances of pseudoidentity increase, and mixtures that 

are very unlike may, as interpreted by analysis alone, appear to be 

the same. Even when the analyses show empirical differences, the 

molecular ratios may become identical, and therefore deceptive. 

Mere analysis, then, does not furnish a complete basis for rock classification. It takes us one step toward the goal, but other-steps must 

follow. The chemical constitution of a rock, as indicated by its 

proximate ingredients, is fully as important a factor in its classification as its ultimate composition.

Two suggestions, intended to be helpful in at least a partial classification of igneous rocks, may be noticed briefly here. A. N. Winchell 2 proposes to divide the rocks into three classes, peralkaline, 

alkaline, and alkalcic. The first class includes such rocks as the 

nepheline syenites, which contain a high proportion of alkalies. The 

second class comprises those which are characterized by feldspathic 

minerals. In the third class are placed the rocks which are relatively 

deficient in alkalies. The other suggestion, by S. J. Shand, 3 provides

i For example, H. Andesner (Neues Jahrb., Beil. Band 30,1910, p. 467) fused a hornblendite containing 

principally hornblende, and some zoisite, quartz, rntile, and apatite. The product had the character of 

a basalt, with microscopic crystals of magnetite, augite, and plagioclase.

»Jour. Geology, vol. 21, p. 208,1913.

* Geol. Mag., 1913, p. 508. A criticism by A. Scott is in the same journal for 1914, p. 3i9", followed by a 

reply from Shand, p. 485. Another paper by Shand is in Geol. Mag., 1917, p. 463.
IGNEOUS BOOKS. 419

for two main classes, which he calls saturated and unsaturated rocks. 

Unsaturated minerals, which characterize the latter class, are those 

which, like nephelite and olivine, are capable of taking up more 

silica, forming feldspar and pyroxene. Rocks in which such minerals 

are conspicuous are called unsaturated. The saturated minerals and 

rocks, obviously, are those in which no more silica can be assimilated 

by the silicates; and also those in which free silica appears. The 

rocks containing free silica are also called oversaturatcd; those containing a large proportion of free basic oxides, undersaturated; and 

rocks with intermediate composition that is, with both saturated 

and unsaturatcd minerals are termed part saturated. The classification devised by Shand has therefore a fivefold basis, which gives 

it a fair degree of elasticity. A. Holmes * has accepted this classification in part and has modified it in some particulars. Holmes, 

however, adopts the "normative" minerals of the modern quantitative classification, while Shand prefers the "modal" or actual minerals. Such classifications do not claim completeness, but they give 

good starting points from which the necessary details can be developed. For a partial working out of such details the original memoirs 

should be consulted.

The classification of igneous rocks on the basis of eutectic mixtures, 

advocated by G. F. Becker,2 is of a different order from either of the 

other systems. Rocks, considered in the mass, are variable comminglings of minerals; but the eutectics, being definite mixtures, may 

be taken as the standard types. From this point of view the 

groundmass of a rock becomes its most characteristic feature, and 

the phenocrysts are only the accidental excesses of one constituent 

or another over the eutectic ratio. The importance of this principle 

has been already discussed in a previous chapter, 3 and its application 

to petrography is foreshadowed in the writings of Guthrie, Lagorio, 

Teall, Lane, and Vogt. 4 That magmas and the products of their 

solidification must be studied on physicochemical lines is generally 

admitted, and a eutectic classification would seem to follow naturally 

from that kind of investigation. At present, however, such a 

classification is only a matter of theory, and its effectiveness can 

not be tested until a reasonable number of eutectics have been 

identified and described. Teall, Lane, and Vogt all agree in thinking

i Geol. Mag., 1917, p. 115.

a Twenty-first Ann. Rept. U. S. Geol. Survey, pt. 3, 1901, p. 519. Science, 1st scr., vol. 20,1904, p. 550, 

Pub. Carnegie Inst. Washington No. 31.

3 See ante, Chapter IX, p. 295.

* F. Guthrie, Pliilos. Mag., 4th ser., vol. 49,1875, p. 20. A. Lagorio, Min. pet. Mitt., vol. 8,18S7, p. 421. 

J. J. H. Teall, British petrography, 1888, pp. 392-402. A. C. Lane, Jour. Geology, vol. 12,1904, p. 83. J. H. L. 

Vogt, Die Silikatschmelzlosungen, pt. 1,1903, pp. 101-107;°pt. 2,1904, pp. 113-128; and Min. pet. Mitt.,vol. 

25,1906, p. 3C1. Later discussions of the subject arc by H. E. Johannson, Geol. Foren. Forhandl., vol. 27, 

1905, p. 119; S. Zcm6uzny and F. Loewinson-Lessing, Geol. Centralbl., vol. 8,1906, p. 393; and A. Bygdta, 

Bull. Geol. Inst. Upsala, vol. 7, 1906, p. 1. Some difficulties in the way of a eutectic classification have 

boon clearly pointed out by W. Cross in Quart. Jour. Geol. Soc., vol. 66,1910, pp. 485-488.
420 DATA OF GEOCHEMISTRY.

that micropegmatite is a eutectic mixture of quartz and feldspar, 

and Vogt has gone still further in the development of probabilities. 

In a recent memoir * he has sought to show that a large number of 

eruptive rocks fall into two classes, which he terms "anchieutektische" and '' anchi-monomineralische"; that is, nearly 

eutectic and nearly composed of one mineral alone. Under the 

latter heading fall those anorthosites, pyroxenites, peridotites, etc., 

which happen to consist of single minerals to the extent of 90 per 

cent or more. The nearly eutectics he illustrates chiefly by the 

micropegmatites. The suggested eutectics, however, are not yet 

fully established, and the proposed classification can not be attempted 

until much more experimental work has been done. Its difficulties 

will be chiefly manifest in dealing with multicomponent systems, 

and to anything beyond a three-component group of minerals its 

application may be impracticable. Its units, it must be observed, 

are those of the mineralogical system, with which it is much more 

nearly allied than with the classification by radicles or oxides. The 

classification by analyses deals with the latter, the mineralogical 

method with the compounds which actually appear to the eye. To 

a considerable extent the three systems lead to the same grouping 

of rocks, and it remains to be seen whether the study of the eutectics 

may not bring both physical and chemical data still more into harmony. In a complete classification the systems should converge, 

each one to the reinforcement of the others. The prevalence of a few 

clearly marked rock types may, perhaps, be explained when the 

eutectic mixtures are known.

Now, recognizing the fact that all classifications of the igneous 

rocks are at present more or less arbitrary, let us consider the two 

available systems together. We may also take into account a very 

rough, provisional classification of the rocks, which serves a certain 

descriptive purpose in helping us to avoid verbiage. I refer to the 

division of rocks into two classes, namely, the "basic" and the 

"acid," to which, if it were valid, a third "neutral" group should 

be added. These terms, as used by petrographers, have little more 

than colloquial significance and serve to indicate whether a rock 

contains much or little silica. They are, however, objectionable 

and possibly misleading, for the two terms as used in chemistry 

have a more precise and quite different significance. Their fallaciousness can be illustrated by considering the composition of the 

two fundamental olivines, forsterite and fayalite, Mg2Si04 and 

Fe2Si04.____________________________________

> Norsk Geol. Tidsskr., vol. 1, No. 2, 1905; and Vidensk. Selskabets Skrifter, Math.-nat. Klasse, 1908, 

No. 10. Vogt's nomenclature suggests that the igneous rocks might be briefly described by the adjectives 

unicomponent, bicomponent, tricomponent, and possibly multicomponent, with reference, obviously, to 

their principal constituents and regarding small amounts of accessory minerals as impurities. In such 

a classification it would be necessary to regard isomorphous mixtures, like the plagioclascs, as single 

components.
IGNEOUS ROCKS.

Composition offorsteritc andfayalite.

421

SiO,.. .....................................................

MgO. ......................................................

FeO

Forsteritc.

42.8

57.2

100.0

Fayalite.

29.5

70 ^

100.0

Here are two definite orthosilicates of the same simple type which 

replace each other isomorphously. Chemically they are both neutral 

salts, and yet one contains 13.3 per cent more silica than the other. 

The terms acid and basic are here obviously inapplicable, and the 

case cited is but one of many. It is desirable, then, that the two 

terms should be, generally speaking, dropped from petrographic 

usage and replaced by others which do not conflict with good chemical 

nomenclature. Acidic and lasylic might be better; but a closer subdivision would be effective by using the self-explanatory expressions 

persilicic, mediosilicic, and subsilicic. Conventionally these terms 

might represent silica percentages of more than 60, between 50 and 

60, and below 50. A more precise definition is undesirable. Another 

alternative is offered by the words salic, salfemic, and femic, which 

appear in a classification of rocks to be considered presently. A few 

rocks, consisting mainly of corundum or magnetite that is, of basic 

oxides may be properly termed basic. These are the only important 

exceptions to the rule here laid down. A quartz rock, obviously, 

would be in the highest degree persilicic.

In their volume upon the "Quantitative classification of igneous 

rocks,"1 by W. Cross, J. P. Iddings, L. V. Pirsson, and H. S. Washington, the first-named author has given a very full, critical summary 

of the different systems of rock classification which had been seriously 

proposed. To discuss all of these systems, with their nonchemical 

features, would be impracticable in a work on geochemistry, and also 

superfluous, for the details are easily found elsewhere.2 It will be 

enough for present purposes to examine the scheme of arrangement 

offered by the authors of the book just cited and to see how nearly it 

corresponds with the evidence offered by mineralogy. It is the

1 Chicago, University of Chicago Press, 1903.

2 Among the modern classifications the'following are especially important: H. Roscnbusch, Elemcnto 

dcr Gesteinslehre, 1898, p. 66. J. J. H. Teall, British petrography, 1888, pp. 70-77. F. Locwinson-Lcsslng, 

Compt. rend. VII Cong. ge"ol. internat., 1897, p. 193. A. Osann, Min. pet. Mitt., vol. 19,1900, p. 351; vol. 

20,1901, p. 399; vol. 21,1902, p. 365; vol. 22,1903, pp. 322, 403. Osann's system is distinctly chemical; the 

others are mineralogical. See also the " Kern-theorie " of Rosenbusch (Min. pet. Mitt., vol. 11,1900, p. 144) 

which is a chemical classification of magmas, and the discussion of it by W. C. Brogger, Die Eruptivgesteino 

des Kristianiagebietcs, pt. 3,1898, p. 302. A paper by E. Sommerfeldt (Centralbl. Min., Geol. u. Pal., 1907, 

p. 2) relates to a part of the Rosenbusch theory. Recent papers on classification are by F. H. Hatch, Sci. 

Progress, Oct., 1908: A. Schwantke, Centralbl. Min., Geol. n. Pal., 1910, p. 169; W. Cross, Quart. Jour. Gcol. 

Soc., vol. 66,1910, p. 470, and Am. Jour. Sci., 4th ser., vol. 39,1915, p. 657; F. C. Lincoln, Econ. Geology, 

vol. 8,1913, p. 551.
422 DATA OF GEOCHEMISTRY.

most complete scheme of its kind that has as yet been suggested and 

the one most thoroughly worked out; it therefore deserves a very 

careful consideration.

The quantitative classification starts from the chemical analysis of 

a rock, and begins with a division of the magmas into two groups, 

the salic and the femic. The rock-forming minerals are similarly 

divided into two principal classes; the one, as its name indicates, 

being characterized by compounds of silica and aZumina, and the 

others by/erro-magnesian substances. Between the two groups of 

minerals there is an intermediate alferric group, which is given 

subordinate value3 in the classification. The salic minerals, including 

zircon as an accessory, are as follows (the symbols used for purposes of notation accompany the names of the species):

Quartz, Si02 ..................................................... Q.

Zircon, Zr02 .Si02 . -....'..................................-...... Z.

Corundum, A1203 ................................................ C.

Orthoclase, K2O.Al203 .6Si02 ..- -........ or.

Albite, Na2O.Al203.6Si02 ............... ab.

Anorthite, CaO.Al203 .2Si02 .............. an.

Leucite, K2O.Al203 .4Si02 --.............. lc.'

Nephelite, Na2O.Al203 .2Si02 ............. ne.

Kaliophilite, K2O.Al2O3 .2Si02 .......... kp.

Sodalite, 3(Na2O.Al203 .2Si02).2NaCl.... so. 

Noselite, 2(NasO.Al808 .2Si02 ).Na2S04 .... no.J

...... P.

Feldspars.

.................... L.

 Lenads, 1 or feldspathoids.

Mineralogically, muscovite, analcite, haiiynite, and cancrinite 

should appear in this list; but they are omitted in order to simplify 

calculations. Muscovite, for instance, in computing the mineral composition of a rock, is conventionally regarded as if it were a mixture 

of orthoclase and corundum. Analcite is treated in a similar manner and represented by a mixture of albite, nephelite, and water. 

One consequence of this procedure is that the normative composition 

of a rock, as calculated from, the minerals given in the list, often 

varies from its actual or modal composition. A rock containing 

quartz, orthoclase, and muscovite would be represented by a norm of 

quartz, orthoclase, and corundum, with the water of the muscovite 

left entirely out of consideration. The conventional composition of a 

rock, its norm, may be quite unlike its actual composition or, in the 

nomenclature of the new system, its mode. This method of computation, then, does not profess to represent mineral compositions exactly; 

and there is therefore danger that in certain cases it may be misleading that is, if its avowed limitations are not kept constantly in 

mind. In rocks like the mixture cited above corundum does not 

normally occur, as may be seen from the experiments by Morozewicz 

described in the preceding chapter. The intentional variation from

i From Icucite and nephelite.
IGNEOUS ROCKS. 423

reality is simply an evasion of the difficulties which often arise in calculating from the analysis of a rock its mineral composition. As a 

mathematical device it is perhaps legitimate, but it must not be misinterpreted.

The group of femic minerals, as its name indicates,, is dominantly 

ferromagnesian, but not exclusively so. The species recognized in 

the classification as standard are as follows:

Acmite, Na2O.Fe203 .4Si02 -........................ac.

Sodium metasilicate, Na2O.Si02 ...................ns.

Potassium metasilicate, K2O.Si02 .................. ks.

Diopside, CaO.(MgFe)0.2Si02 . -.................... di.

Wollastonite, CaO.Si02 ............................ wo.

Hypersthene, (MgFe)O.Si02 ......................hy.

Olivine, 2(MgFe)O.Si02 .........................ol. 1 Q

Akermanite, 4Ca0.3Si03..........................am. / 

Magnetite, FeO.Fe203 ..........................ml

Chromite, FeO.Cr203 .............................cm. H.

Hematite, Fe203 ................................hm.

Ilmenite, FeO.Ti02 ............................ .11.

Titanite, CaO.Ti02 .Si02 ........................tn. T.

Perofskite, CaO.Ti02 .............................pf.

Rutile, Ti02 .................................. .'.ru.

Apatite, 3(3CaO.P205).CaF2 ......................ap.

Fluorite, CaF2 ...................................fr.

Calcite, CaO.C02................................cc.

Pyrite, FeS2 ....................................pr.

Native metals and other metallic oxides and sulphides.

Here, as with the salic minerals, certain conventions have been 

adopted. The two metasilicates of sodium and potassium do not exist 

as independent mineral species, but appear as possible components of 

certain pyroxenes and amphiboles. The two last-named groups, 

moreover, are not separately identified in the table, but are represented by the minerals embraced under the general symbol P. The 

aluminous ferromagnesian and salic minerals, the alferric compounds 

biotite, garnet, tourmaline, melilite, spinel, and the aluminous 

pyroxenes and amphiboles are not taken into account as normative 

or standard species. In computing the norm of a rock they are 

treated as mixtures of other molecules by devices like those adopted 

in the salic division. From the norm the mode can be approximately 

calculated by methods which are fully discussed in the " Quantitative 

classification." An example of the differences which thus appear 

may be cited from the discussion of Butte granite, on pages 223-225 of 

that work. Under norm is given the composition in standard or conventional minerals and under mode the percentages of the species 

actually present in the rock.
424 DATA OF GEOCHEMISTRY.

Composition of Bvttc granite.

Norm.

Quartz..................... 19.38

Orthoclase................ 25.021

Albite..................... 23. 58[66. 67

Anorthite................. 18.071

Diopside.................. . 671

Hypersthene.............. 6. 78)

Magnetite................. 3. Oil

Ilmenite................... 1. 22/

Pyrite..................... .241

Apatite..................... . 31/

Etc........................ .99

7.45

4.23

,55

99.27

Mode. 

Quartz .................... 22. 86

Orthoclase. ................ 18. 351

Albite. ................... 23. 06 [58. 09

Anorthite.. ................ 16. 6sJ

Biotite.... . ................ 10. 92J

Hornblende............... 3.56/

Manetite. ................. 1. 861

Ilmenite. /

Pyrite. .

............. .46

............. .241

Apatite.................... . 31

Etc....................... .85

48

32

,55

99.15

The divergence between convention and reality is e^ddent at a 

glance. In many cases, however, the norm and mode of a rock are 

practically identical, and then the standard computation is more 

satisfactory. The normative and actual minerals may or may not 

be the same. Some discrepancies/ however, exist, to which much 

weight can not be given. In calculating the percentage of a mineral 

from the proportions of oxides shown by analysis there is a strong 

tendency toward the multiplication of errors. Alumina, for instance, 

is often uncertain, at least in ordinary analyses of fair average quality, 

by as much as one-half of 1 per cent. This amount corresponds to an 

error in Orthoclase, if all the alumina goes to that mineral, of 2.7 per 

cent, and the variation entrains others, especially in the estimation 

of the residual quartz. The computed mineral composition of a rock 

is incorrect by multiples of the errors existing in the analysis, and 

these may be, in fact are, sometimes large.

The normative or standard minerals, then, so far as the make-up of 

a rock is concerned, are partly real and partly conventional. They 

are, however, quantitative in application and give uniformity to the 

discussion of rocks. Upon them the quantitative classification is 

founded..

First, all igneous rocks are divided into five classes, which are 

iixed within certain arbitrary limits by the ratios between the salic 

and femic minerals. These classes are as follows:

I. Persalane: Extremely salic

II. Dosalane: Dominantly salic

III. Salfeinane: Equally salic and femic..

IV. Dofemane: Dominantly femic. 

V. Perfemane: Extremely femic.

id femic....

sal ,

fern ' 

sal

fern 

sal

tem

H-

/ 7 5

^ 1 > 3 

/5 3

o o

sal 3 . 

fern ^5 

sal 1 i'emT <-~7~
IGNEOUS ROCKS. 425

That is, the field between an entirely salic rock and one entirely 

femic is divided into five parts, each representing a definite range of 

variation. A rock containing more than seven-eighths of salic minerals to one-eighth femic is in the class persalane; one with less than 

seven-eighths salic to more than three-eighths femic falls under 

dosalane, and so on. A granite, for example, containing over 87.5 

per cent of quartz and feldspar is placed in Class I; a peridotite 

with over 87.5 per cent of femic minerals belongs in Class V. Many 

basalts, gabbros, diorites, etc., contain salic and femic compounds in 

nearly equal proportions, and are therefore in Class III. From the 

norm of a rock its class can be determined at once, and in many cases 

a mere inspection of the analysis is sufficient. The two extreme 

classes occupy each one-eighth of the field ; the other classes divide 

the remaining six-eighths between them.

The division of classes into subclasses is based upon a previous 

division among the standard minerals themselves. Thus the salic 

minerals are grouped as quartz, Q; feldspar, F; lenads, or feldspathoids, L; corundum, C; and zircon, Z. Q, F, and L are placed 

together as one subclass; C and Z as another. In the femic series 

we have, first, pyroxenes, P; olivine and akermanite, 0; with the 

group of iron ores and titanium minerals, M; and, second, the accessories apatite, fluorite, p37rite, etc., represented by A. In Classes I 

to III the subdivision is effected through the ratio QFL to CZ by the 

same fivefold process, one-eighth, two-eighths, and so on, as in the 

formation of classes themselves. In Classes IV and V, the dofemic 

and perfemic, the ratio POM to A is used in precisely the same way. 

There are therefore twenty-five subclasses, but the vast majority of 

igneous rocks belong to the first subclass in each class. These are 

indicated by the expressions 

the minerals thus given prominence being those which make up the 

greater part of the lithosphere. Rocks in which C, Z, or A abound 

are not common, and their distribution or volume is extremely 

limited.

After the subclasses come the orders, which are formed according 

to the proportions, in the rocks, of the preponderating minerals. In 

Classes I to III the salic minerals are used as a basis for subdivision, 

and the ratios connecting Q, F, and L are alone considered. Quartz 

and the lenads, however, are chemically antithetic, and do not occur 

together; and this leads to a doubling of the ordinary fivefold division of a class, with one term dropped out. That is, each class is 

divided into nine orders; if there were ten, the fifth and sixth would
426 DATA OF GEOCHEMISTRY.

practically, although not absolutely, repeat each other. These orders

are as follows :

Q 7

1. Perquaric: Quartz extreme . . .................... > 

F 1

Q 7 5

2. Doquaric: Quartz dominant. .................... < > 

F 1 3

Q 5 3

3. Quarfelic: Equal quartz and feldspar. ............. < > 

F 3 5

Q 3 1

4. Quardofelic: Feldspar dominant. ................ < > 

F 5 7 

Q or L 1

5. Perf elic : Feldspar extreme ....................... < 

F 7 

L 3 1

6. Lendofelic: Feldspar dominant. .................. < > 

F 5 7

I; 5

7. LenCelic: Equal feldspar and lenad .............. < > 

3 5

7

8. Dolenic: Lenad dominant. . ..................... < > 

F i r,

L 7

9. Perlenic: Lenad extreme ........................ > 

F .1.

In Classes IV and V the femic ratio P+O: M is used to designate 

the orders. They are:

P+O 7

1. Perpolic: Silicate extreme...................... > 

M 1 

P+O 7 5

2. Dopolic: Silicate dominant..................... < > 

M 13 

P+O 5 3

3. Polmitic: Silicate and nonsilicate equal. ........ < > 

M 3 5 

.P+O 3 1

4. Domitic: Nonsilicate dominant..... ............ < > 

M 5 7 

P+O 1

5. Permitic: Nonsilicate extreme. ................. < 

M 7

In orders 1 to 3 there is also a precisely similar fivefold division 

into sections, which indicate the proportions between pyroxenes and 

the olivine subgroup. In orders 4 and 5 a like subdivision into suborders is based upon the ratio H : T, hematite plus magnetite on the 

one hand and the titanium minerals ilmenite, titanite, perofskite, 

and rutile on the other. It is not necessary for present purposes to 

carry these subdivisions out in detail, for the ratios are expressed by 

precisely the same fractions as appear in the classes and orders.

Up to this point the quantitative classification has been mineralogical, and expressed in terms of the standard or normative minerals.
IGNEOUS ROCKS. 427

The division of orders into rangs, however, proceeds on chemical 

lines, but is still fivefold as before. In Classes I to III, which are 

characterized by feldspars and lenads, the molecular ratio of salic 

K20+Na20 to salic CaO is the determining factor. In Classes IV 

and V the molecular ratio of femic CaO + (MgFe) O to femic alkalies is 

considered. By salic CaO is meant the lime in salic minerals such 

as anorthite; femic lime is that in diopside, wollastonite, etc. Salic 

alkalies are found in feldspars and lenads; femic alkalies occur in 

acmite and certain other pyroxenes and amphiboles. In the partition of actual minerals, such as the micas, between the two normative groups, the potash of muscovite will go to the salic side, while 

that of biotite is regarded as femic. Now, uniting K20 and Na20 

under the general symbol of R20, the rangs under the orders of 

Classes I to III develop thus:

RoO 7

A IT-'d 1 "1 / »£! \ f*l f*

T*lfW*Q 1 fl f*

Percalcic. . ..............................

CaO 

R20

CaO 

R2 0

CaO 

R20

CaO 

R20

X

1

7 ^ v

1

5 < - -

3 

3

S* "-

5

1 ^

5

3 

3

5 

1

7

CaO 7

The nomenclature here would seem to be self-explanatory, but in 

Classes IV and V a less obvious device is proposed, namely to indicate magnesium, iron, and fame the word mirlic is suggested. Uniting MgO, FeO, and CaO under the symbol HO we now have in the 

distinctively femic classes these rangs:

RO 7

R20 

RO

RoO 

RO

R,,0 

RO

RoO 

RO

- > -" 

1

7 5 f^ -v

1 3 

5 3 

-< > 

3 5

3 1 <~^,

5 7 

1

5. Peralkalic..................................... < 

RoO 7

The femic rangs are again subjected to a fivefold subdivision into 

sections, depending upon the ratio (MgFe)O to CaO; and they are also 

divided into subrange which indicate the ratio between magnesia
428 DATA OF GEOCHEMISTRY.

and ferrous oxide. So also, in Classes I to III there are subrangs 

based upon the alkalies alone, and these are called, respectively, perpotassic, dopotassic, sodipotassic, dosodic, and persodic. These subrangs are still further divisible in such manner as to show the ratios 

between the lenad minerals leucite and nephelite, and sodalite and 

noselite, and either of these pairs may be subdivided in the same way. 

In some of these cases a threefold division is employed instead of the 

usual method. In Classes II, III, and IV the rangs are again divided 

into grads, which serve to classify the subordinate minerals. In 

Classes II and III the subordinate femic group is divided according 

to the ratio P + O to M, just as in forming the orders of Classes IV 

and V. In Class IV the subordinate salic minerals serve to designate 

five grads, depending upon the relations between quartz, feldspars, 

and lenads. In Class III there is also a threefold discrimination 

between pyroxene and olivine, forming the sections prepyric, pyrolic, 

and preolic. Furthermore, precisely as rangs are formed within orders 

so subgrads are formed within grads. That is, the ratios RO to R30; 

R2O to CaO; (MgFe)O to CaO; and MgO to FeO are used to express 

between subordinate minerals the same relations that hold in forming 

the larger divisions of the classification.

The quantitative classification, then, takes pairs of factors, and 

divides each pair, with a few limitations only, into five terms, expressive of different ratios. This process, obviously, can be carried 

out to any desired degree of minuteness; but for most practical purposes four subdivisions are generally enough. These may be stated 

as classes, orders, rangs, and subrangs; the subclasses, suborders, 

grads, etc., being less useful in actual work. In order to express the 

composition of a rock, or, more precisely, of a magma, a simple 

notation has been devised, which makes use of numerals to indicate 

the several subdivisions. Thus the symbol II.5.2.3 indicates that 

the magma which it represents belongs in Class II, dosalane; order 5, 

perfelic; rang 2, domalkalic; and subrang 3, sodipotassic.1 That 

such a system is convenient we can see at a glance; but its limitations, 

due to the distinction between normative and actual minerals, must 

never be overlooked. Analyses are readily classified and summarized by the system; as regards minerals it is confessedly incomplete. 

The important alferric minerals muscovite, biotite, augite, and hornblende fall outside of the classification, and have to be expressed by 

means of a recalculation from a norm into a mode. It is an artificial 

classification of great provisional value; but its ultimate standing is 

yet to be determined by the severe tests of experience. Even if it 

should be finally adopted by all petrologists, some form of classifica1 For the detailed development of this notation, which can be extended to grads and subgrads, see H. 8. 

Washington, Prof. Paper U. S. Geol. Survey No. 28,1904, pp. 13-15. On the calculation of norms, see G. I. 

Finlay, Jour. Geology, vol. 18,1910, p. 58.
IGNEOUS ROCKS. 429

tion like that now in vogue would have to be retained with it. Good 

analyses can not be obtained for every rock which the geologist is 

called upon to determine, and in many cases he must be content with 

the results of a microscopic examination. He can then say at once 

that a certain rock consists of alkali feldspar, quartz, and subordinate 

femic minerals, and so define it as a granite or rhyolite. To accurately 

name its subrang is a more troublesome matter, and impracticable 

without analytical data. 1 In short, the quantitative system can only 

be applied to the classification of rocks which have been quantitatively 

studied, but then it yields results of unquestionable utility. It brings 

to light magmatic analogies which might not be recognized without 

its aid, and so assists in the comparison of magmas and in the study 

of their differentiation. From the application of the classification to 

the study of rocks, one highly beneficent result has already followed. 

The three memoirs of H. S. Washington,2 in which he has collected and 

classified all the trustworthy rock analyses which had been recorded 

between 1869 and 1913, are of the highest value and go far to justify 

the system.

COMPOSITION OF ROCKS.

Now, passing on from the. general statements relative to classifications, we may consider the actual composition of rocks as revealed 

by chemical analysis. In order to do this most advantageously, and 

to compare classifications, the ordinary mineralogical grouping will 

be followed, but the rocks within each group will be arranged in the 

order of the quantitative system, and the brief description of each 

one will precede the analyses. To the descriptions the magmatic 

symbols and magmatic names are appended, and after each table 

the composition of the norms, as found in Washington's tables, will 

be given. We shall thus be able to see how nearly the two classifications coincide, and so be better fitted to judge of their comparative merits. As a rule, the analyses are those which have been 

made in the laboratory of the United States Geological Survey, and 

are cited from the collection published in Bulletin No. 591. Only 

those are selected which have been characterized by Washington 

as excellent. In a few cases analyses from other sources must be 

used, but due credit will be given. Since rocks are aggregates of 

minerals, all sorts of intermediate variations are possible, but in a

1 The need of rock names for field use is fully recognized by the authors of the quantitative system.

^ Prof. Papers U.S. Geol. Survey Nos. 14,28, and 99. For analyses made in the laboratories of the Survey, 

see also Bull. No. 591. For an extended application of the quantitative classification, see Washington'3 

Roman comagmatic region, Pub. No. 51 of the Carnegie Institution, 1906. For reviews and criticisms of 

the new system, see A. Michel-Le'vy, Bull. Carte geol. France, No. 92,1903; A. Hfarker], Geol. Mag., 1903, 

p. 173; J. AV. Evans, Science Progress, vol. 1,1906, p. 259; E. B. Mathews, Am. Geologist, vol. 31,1903, 

p. 399; L. Milch, Ccntralbl. Min., Geol. u. Pal., 1903, p. 677; G. W. Tyrrell, Science Progress, vol. 9, p. Cl, 

1914; and L. L. Fermor, Rec. Geol. Survey India, vol. 42,1912, p. 208.
4 SO DATA OF GEOCHEMISTRY.

work of this general character such minor details of classification 

must be ignored. Only the larger features of the subject can be 

taken into account.

THE RHYOLITE-GRANITE GROUP.

In Class I of the quantitative classification, order 1, perquaric, is 

represented by rocks which consist mainly of quartz, such as quartz 

veins and segregations of igneous origin. In order 2, doquaric, 

Washington places a few rocks which contain from 53 to 69 per cent 

of quaj-tz, but none of them is. particularly important. It is in 

order 3, quarfelic, that the noteworthy rocks begin to appear, and 

a large number of them belong in the familiar group of rhyolites 

and granites. With this group it is convenient to begin.

In the broadest sense, granite may be defined as a holocrystalline, 

plutoiiic rock, consisting chiefly of quartz and an alkali feldspar, the 

latter being commonly orthoclase or microcline. A soda granite is 

one containing a soda feldspar, preferably anorthoclase. With 

these dominant minerals there may be, and usually are, subordinate 

species, such as muscovite, biotite, hornblende, etc. Hence the 

varieties muscovite granite, biotite granite or granitite, hornblende 

granite, tourmaline granite, and the like. When only quartz and 

feldspar are present the rock is called aplite, although it must be 

observed that this term is often used in other senses. 1 Khyolite is 

the eruptive equivalent of granite and has the same chemical composition. The minerals which develop individually in it are also 

broadly the same, quartz and alkali feldspar largely predominating. 

Rhyolite, however, very commonly contains more or less undifferentiated glass, and obsidian is a wholly vitreous variety. The 

quartz porphyries, which are intermediate between granites and 

rhyolites, are old, devitrified forms of the latter. Nevadite, liparite, 

and quartz trachyte are synonyms for rhyolite. The differences 

between granite and rhyolite are structural and genetic; chemically 

and magmatically they are the same. This essential identity of 

composition appears in the subjoined tables of analyses. First in 

order come the rhyolites.

i On account of this ambiguity in the use of the word aplite, J. E. Spurr has proposed the name 

"alaskite" for rocks of this character. For the corresponding eruptive or fine-grained porphyritic rocks 

the term "tordrillite" is offered. Am. Geologist, vol. 25, 1900, p. 229. On the formation of granite see 

H. Le Chatelier, Annales des mines, 8th ser., vol. 13, 1888, p. 232. On the origin of pegmatite see J. B. 

Hastings,Trans. Am. Inst.Min. Eng., vol. 39,1909,p. 104; E. S. Bastm, Jour. Geology, vol. 18,1910, p. 297; 

and A. Harker, Natural history of igneous rocks, p. 293. On the origin of granite see A. Brun, Eclog. Geol. 

Helvet., vol. 12,1912, p. 172.
IGNEOUS ROCKS. 431

Analyses ofrhyolites.

A. From Buena Vista Peak, Amador County, California. Analysis by W. F. Hillebrand. Described 

by H. W. Turner as containing sanidine, quartz, and biotite in a glassy groundmass. Magmatic symbol,

1.3.1.2. Magdeburgosc.

B. From near Willow Lake, Plumas County, California. Analysis by Hillebrand. Described by J. S. 

Diller as containing phenocrysts of quartz and feldspar, in a groundmass of the same materials. Symbol,

1.3.1.3. Alaskose.

C. Obsidian, Obsidian Cliff, Yellowstone National Park. Analysis by J. E. Whitfield. Described by 

Arnold Hague and J. P. Iddings. A glass containing microlites of augite and ferric oxide, with traces 

of quartz and feldspar. Symbol, 1.3.1.3. Alaskose.

D. From Madison Plateau, Yellowstone National Park. Analysis by Whitfield. Not described. 

Symbol, 1.3.1.4.

E. From the Hyde Park dike, Butte district, Montana. Analysis by H. N. Stokes. Contains, accordIng to W. H. Weed, sanidine, quartz, plagioclase, and biotite, in a groundmass of quartz and feldspar. 

Symbol, 1.3.2.3. Tehdmose.

F. From "Elephant's Back," Yellowstone National Park. Analysis by Whitfield. Reported by 

J. P. Iddings to contain quartz and sanidine, with a little augite and magnetite, in a glassy groundmass. 

gymbol, 1.3.2.3. Tchamose.

G. From Haystack Mountain, Aroostook County, Maine. Analysis by Hillebrand. Described by 

H. E. Gregory. Contains quartz, albite, and orthoclasc, with titanite and accessory chlorite and kaolin. 

Symbol, 1.4.1.3. Liparose.

H. From Crater Lake, Oregon. Analysis by Stokes. Described by H.B.Patton. Contains plagioclase, 

hornblende, hypersthenc, and magnetite, in a glassy groundmass crowded with microlites of feldspar 

and augite. Symbol, 1.4.2.4. Lassenose.

SiO,... ............

Ala<53 .... .. ........

Fe203 - ....... ------

FeO................

MgO...............

CaO...............

NaaO..............

K.,0. ...............

HaO-. .............

HaO+. .............

Ti02 . ..............

ZrOo. ..............

P Or

MnO. ..............

BaO...............

SrO................

Li20. ..............

SO,. ................

PeS2 ...............

Cl. .................

A

73.23

12.73

.99

.16

.22

.61

1.91

5.17

.53

4.51

.09

.02

Trace.

.02

^TVapn

100. 19

B

74.24

14.50

1.27

' .67

.25

.11

3.00

3.66

2.04

.20

.07

06

.18

Trace.

TVnnp

.03

100. 28

 c

75.52

14.11

1.74

.08

.10

.78

3.92

3.63

} .39

None.

None.

.11

100. 38

:D

75.19

13.77

.61

1.37

.09

.68

3.83

3.33

I K

> . 65

Npne.

Trace:

.02

.29

99.83

E

74.34

12.97

.75

.54

.86

.85

2.49

4.72

1.03

1.11

.18

.05

.07

Trace.

.07

Trace.

Trarp

.03

100. 06

F

75.34

12.51

.42

1.55

.32

1. 07

3.31

4.17

. 00

None.

.07

Trace.

..42

100. 04

f!

75.98

12. 34

.85

.93

.15

.13

4.02

4.44

.24

.64

.17

.03

.03

Trace?

.07

Trace?

100. 02

H

71.87

14.53

1.28

1.02

.48

1.59

5.08

2.84

.06

.22

.41

.04

.10

.08

.03

Trace.

99. G3

Norms.

Q.. ................

or. .................

ab. .................

an ..................

C. .................

hy.. ........ ........

mt. ................

il..................

A

40.7

31.1

15.7

2.8

3.0

.6

.5

1.1

B

42.0

21.7

25.2

.6.

5.4

.6

1.9

C

36.7

21.7

33.0

3.9

2.2

.3

.2

1.6

D

38.2

 19.5

32.0

3.3

2.8

2.2

.9

E

38.7

27.8

21.0

4.2

2.2

2.4

1.2

V

36.1

25.0

27.8

5.6

.4

3.3

.7

0

35.1

26.1

33.5

.6

.8

1.4

1.2

H

27.4

1C. 7

43.0

8.1

1 9

1.4
432 DATA OF GEOCHEMISTRY.

The following anatyses represent quartz porphyry:

Analyses of quartz porphyry.

A. From near Blowing Rock, Watauga County, North Carolina. Analysis by W. F. Hillebrand. Reported by A. Keith to contain quartz and orthoclase, with subordinate sericite, chlorite, and biotite. Magmatic symbol, 1.3.1.2. Magdeburgose.

B. From the Modoc mine, Butte district, Montana. Analysis by Hillebrand. Contains, according to 

W. H. Weed, quartz, orthoclase, and plagioclase in a groundmass of quartz and feldspar. Symbol, 1.4.2.3. 

Toscanose.

C. From Prospect Mountain, Leadville district, Colorado. Analysis by L. G. F.akins. Described by 

W. Cross. Contains orthoclase, plagioclase, quartz, biotite, apatite, magnetite, and zircon. Symbol, 

1.4.2.3. Toscanose.

D. From the Swansea mine, Tintic district, Utah. Analysis by H. N. Stokes. Described by G. W. 

Tower and G. 0. Smith. Contains feldspar, quartz, magnetite, apatite, secondary pyrite, and a little 

chlorite and biotite. Symbol, 1.4.2.3. Toscanose.

E. From Grizzly Mountains, riumas County, California. Analysis by Hillebrand. Contains, according to H. W. Turner, quartz, feldspar, and pyrite, in a fine groundmass. Symbol, 1.4.2.3. Toscanose.

Si02 . ...............................

41 O

FeA-- .............................

Feb.................................

MgO.. ..............................

CaO................................

Na,0...............................

K.O.................................

HaO................................

H20+. ..............................

TiOo................................

ZrCfo. CO ............................... "

P206 . ...............................

MnO................................

BaO.............. :.................

SrO.................................

Li,0................................

Cr^O................................. Vo<v ................................ cf..... ..............................

Cu..................................

FeS

A

79.75

10. 47

.64

.92

.13

.15

1.36

6.01

.08

.60

.15

.05

Trace.

Trace.

.06

Trace.

Trace.

100. 37

B

69.95

15.14

.38

.83

.56

1.45

2.70

6.36

.40

.91

.24

.02

.37

.10

.08

.13

.02

Trace.

.03

.39

100. 06

o

73. 50

14.87

.95

.42

.29

2.14

3.46

3.56

} .90

None.

.03

Trace.

100. 12

D

71. 56

, 14.27

f .89

.42

1. 18

3.00

4.37

.36

.79

.38

.13

Trace.

.28

Trace.

None.

Trace.

.01

.06

2.29

99.99

'E

73.25

13.25

1.74

.28

2.23

2.69

3.79

.07

1.03

Trace.

1.05

Trace.

Trace.

Trace.

Trace?

Trace.

.58

99.96

Norms.

Q.. .................................

or. ..................................

ab. ..................................

an ...................................

C....... ............................

di..................................

hy... ................................

rat. .................................

il. ..................................

pr. ..................................

A

47.8

35.6

11.5

.8

1.4

1.4

.8

B

25.5

37.8

22.5

7.2

1.1

2.7

1.1

.5

C

34.7

21.1

29.3

10.6

1.4

.7

1.4

D

34.2

26.1

25.2

5.8

2.5

 1.1

.9

2.3

E

30.1

33.9

22.5

7.2

3.2

2.3

.6
IGNEOUS ROCKS. 433

The subjoined analyses of granites are all by W. F. Hillebrand: 1

Analyses of granites.

A. From Currant Creek Canyon, near Pikes Peak, Colorado. Described by E. B. Mathews. Contains 

microcline, quartz, muscovite, and sericitic aggregates replacing plagioclase and a part of the microcline. 

Magmatic symbol, 1.3.1.2. Magdcburgose.

B. Biotite granite, Sentinel Point, Pikes Peak, Colorado. Described by Mathews. Contains raicrocline, microclme-perthite, quartz, biotite, a little oligoclase, and accessory fluorite, apatite, zircon, spheno., 

allantie, and magnetite. Symbol, 1.3.1.3. Alaskose.

C. From Currant Creek Canyon, Pikes Peak, Colorado. Described by Mathews. Contains perthitic 

microcline, quartz, biotite, muscovite, altered plagioclase, and flakes of limonite. Symbol, 1.4.1.2. 

Omcose.

D. Biotite granite, Mount Ascutney, \rermont. Described by R. S.Daly. Contains quartz, orthoclase, 

plagioclase, biotite, magnetite, sphene, apatite, and zircon. Symbol, 1.4.1.3. Liparose.

E. Soda granite, Pigeon Point, Minnesota. Described by W. S. Bayley. Contains feldspar, quartz, 

chlorite, some muscovite, rutile, leucoxene, hematite, and apatite, and sometimes secondary calcite. 

Symbol, 1.4.1.3. Liparose. 

F. Granitite, near Florissant, Colorado. Described by Mathews. Contains microcline, albite, quartz, 

and biotite. Symbol, 1.4.1.4. Kallerudose.

G. Granite, Big Timber Creek, Crazy Mountains, Montana. Reported by J. E. Wolff as containing 

quartz, orthoclase, oligoclase, and biotite. Symbol, 1.4.2.3. Toscanose.

H. Aplite, Yuba Gap, Sierra County, California. Described by II. \V. Turner. Contains orthoclasc, 

quartz, plagioclase, a little microcline, brown mica, and iron ore. Symbol, 1*4.2. 3. Toscanose.

Si02 .................

Al,03 .. ..............

Fe2 03 ..............'.

FeO................

MgO.... .............

CaO..... ............

Na,0................

K20................

H20...............

HaO+. .............

TiO,.... .............

ZrOa .................

oo

p (1

MnO...............

BaO.. ...............

SrO... '.............

Li,0. ..............

F. ..................

Cl. .................

FeSa . ...............

A

74.40

14.43

.89

.22

.07

.58

1.76

6.56

.15

.92

.12

.22

Trace.

Trace.

Trace.

.04

100. 36

B

77.03

12.00

.76

.86

.04

.80

3.21

4.92

.14

.30

.13

Trace.

Trace.

Trace.

None.

.36

100. 55

C

73.90

13.65

.28

.42

' .14

.23

2.53

7.99

.16

. 33

.07

.05

Trace.

Trace.

None.

Trace.

None.

99.75

D

71.90

14. 12

1.20

.86

.33

1.13

4.52

4.81

.18

.42

.35

.04

.21

. .11

.05

.04

.06

.02

Trace.

100. 35

E

72.42

13.04

.68

2.49

.58

.66

3.44

4.97

} 1.21

.40

.20

.09

.15

Trace?

Trace?

Trace.

100. 33

F

75.92

12.96

.33

1.40

Trace.

.15

4.60

4.15 -.16

.32

.05

.03

Trace.

.04

Trace.

None.

n Vo pp

.12

100. 23

0

74.37

13. 12

.73

.87

.35

1.26

2.57

6.09

.05

.25

.29

.06

Trace.

.10

Trace.

Trace.

100. 11

H

76.03

13. 39

.48

.31

.05

1.28

2.98

5.18

.15

.34

.07

.03

Trace.

.04

Trace.

Non6

100. 33

Norms.

Q........ ..........

or.... ................

ab ..................

C....................

di...... .............

hy..................

mt. ................

U.. ...... ............

A

37.3

38. 9

14.7

2.8

3.5

1.7

.2

B

37.5

29.5

26.7

3.9

1.7

C

28.0

47.3

21.0

1.1

.5

.8

.5

D

24.5

28.4

37.7

4.2

i. i

..3

1.9

.6

E

29.4

30.0

28.8

3.2

.8

5.0

q

.8

F

32.0

24.5

38.8

.8

.6

2.2

.2

Cr

33.1

36.1

22.0

5.8

1.2

1.1

.6

H

36.3

30.6

25.2

5.0

1.0

.7

 ' A. Gautier (Compt. Rend., vol. 132, 1901, p.932) found traces of nitrogen,argon,arsenic, and iodine in 

granite.

'113750° 19 Bull. 695 28
434 DATA OF GEOCHEMISTRY.

All the rocks here cited belong in the first subclass of Class I 

and lie between the limits indicated by the symbols 1.3.1.2 and

I.4.2.4. Some granites appear in Washington's tables under Class

II, but they are few in number and represent, probably, intermediate 

gradations toward the syenites. So far as the foregoing analyses are 

concerned, they show that up to this point the quantitative and 

mineralogical classification coincide fairly well and that the norms 

can not vary very much from the modes. The normative corundum l 

probably represents the mica, either muscovite or biotite, or both, so 

that the actual orthoclase of these rocks must be lower than is shown 

in the norms. The latter show with sufficient emphasis that quartz 

and alkali feldspars are the most important minerals in the graniterhyolite group and that the rocks differ chiefly in the varying proportions of quartz, orthoclase or microcline, and albite or anorthoclase. 

The presence .of much muscovite in a granite, however, would increase 

the divergence between norm and mode, and even throw the rock 

into some other order than those shown by the limiting symbols just

given. 2

THE TRACHYTE-SYENITE GROUP.

The trachyte-syenite series of rocks differs from the rhyolite-granite 

series in being free, or nearly so, from quartz. The trachytes, like 

the rhyelites, are eruptive rocks; the syenites resemble granite in their 

plutonic origin. Between trachyte and syenite there are intermediate 

forms, analogous to the quartz porphyries. All of .these rocks contain 

principally alkali feldspars, with subordinate femic minerals, and 

often alferric species such as hornblende or mica. These minor constituents are recognized in nomenclature by such terms as biotite 

trachyte, mica syenite, hornblende syenite, etc. There are also many 

varietal names, which are based on minor distinctions. The nepheline syenites will be considered separately. The following analyses 

represent typical examples within the series as defined here:

Analyses of trachyte-syenite rocks.

A. Nordmarkite, Mount Ascutney, Vermont. Analysis by W. F. Hillebrand; description by R. A. 

Daly. Contains orthoclase, plagioclase, quartz, hornblende, magnetite, apatite, and zircon, with very 

little biotite, titanite, diopside, and allanite. Magmatic symbol, 1.5.1.3. Plilegrose.

B. Quartz syenite porphyry, Gray Butte, Bearpaw Mountains, Montana. Analysis by H. N. Stokes. 

Described by W. H. Weed and L. V. Pirsson. Contains anorthoclase, microlites of plagioclase, eegirite, 

augite, quartz, and apatite, with an occasional zircon and traces of biotite. Symbol, 1.5.1.4. Nordmarltose.

C. Biotite trachyte, Dike Mountain, Yellowstone National Park. Analysis by Hillebrand. Reported 

by Arnold Hague and T. A. Jaggar as containing plagioclase, orthoclase, biotite, magnetite, and chlorite. 

Symbol, 1.5.1.4. Nordmarliose.

D. Soda syenite porphyry, Moccasin Creek, Tuolumne County, California. Analysis by Stokes. 

Described by H. W. Turner. Consists mainly of albite, with possibly segirite. Symbol, 1.5.1.5. Tuo* 

umnose.

E. Soda syenite, Douglas Island, Alaska. Analysis by Hillebrand. Described by G. F. Becker. Con« 

tains mostly albite, with secondary quartz, calcite, and pyrite. Symbol, 1.5.1.5. Tuolumnose.

F. Biotite trachyte, Dike Mountain, Yellowstone National Park. Analysis by Hillebrand. Reported 

by Hague and Jaggar to con tain orthoclase, plagioclase, biotite, and chlorite. Symbol, 1.5.2.3. Pulaskose.

1 Or undistributed alumina.

2 An important paper on the minor accessories in British granitoid rocks, by R. H. Rastall and W. H. 

Wilcockson, is in Quart. Jour. Geol. Soc., vol. 71,1917, p. 592.
IGNEOUS ROCKS. 435

Analyses of trachyte-syenite rocks Continued.

G. Augite syenite porphyry, Copper Creek bnsin, Yellowstone National Park. Analysis by HillebrandContains, according to Hague and Jaggar, augite, biotite, orthoclase, a little hornblende, and quartz. Sym. 

bol, 1.5.2.4. Lantkose.

H. Augite syenite, Turnback Creek, Tuolumne County, California. Analysis by Stokes. Reported by 

Turner to contain orthoclaso and augite, with less plagloclase and quartz. Symbol, II.5.1.2. Higlnvoodose,

I. Syenite, Yogo Peak, Little Belt Mountains, Montana. Analysis by Hillebrand. Described by Weed 

and Pirsson. Contains orthoclase, oligoclase, quartz, apatite, titanite, iron ores, pyroxene, hornblende 

and biotite, with traces of decomposition products. Symbol, II.5.2.3. Monzonosc.

J. Syenite, La Plata Mountains, Colorado. Analysis by Stokes. Beported by W. Cross to contain much 

alkali feldspar, some oligoclase, augite, biotite, and hornblende, with a little titanite, magnetite, and apatite. 

Symbol, II.2.5.2.3. Monzonose.

K. Syenite, Crazy Mountains, Montana. Analysis by Hillebrand. Reported by J. E. Wolff to contain 

anorthoclase, hornblende, augite, sphene, apatite, and magnetite. Symbol, II.5.2.4. AUcrose,

SiOo......................... AI r>

Fe2 03 -. ...... ................

FeO....:........ .............

MgO...... ...................

CaO.........................

Na20............. ...........

K26........... ...............

H20.......... ...............

H20+... .....................

TiO

ZrOa ................... ......

C0a .. ........................

P O

s6^::::::.v.:::::::::::::::::

01. ..........................

F............. ................

MnO........ .................

BaO.........................

SrO....... ...................

V O

Li20.............. ...........

FeS2 ... ......... .............

Si02 . .........................

AI n

PeA- .......................

FeO..........................

MgO..........................

CaO............................

Na20.. .......................

K26........ ....... ............

E^O-. ......................

E20+. ......................

TiOa .. ........................

ZrOa .......... ................

COo............ ...............

p o

fcv:::::::::::::::::::::

Cl.... ........... ..............

F. ...........................

MnO..........................

%&0......... .................

SrO.... .......................

.Li20..........................

A

65.43

16.11

1.15

2.85

.40

1.49

5.00

5.97

.19

.39

.50

.11

.i3

.05

.08

.23

.03

.07

100. 18

B

66.22

16.22

1.98

.16

.77

1.32

6.49

5.76

.08

.24

.22

.10

.02

.04

Trace.

Trace.

.29

.06

Trace.

99.97

G

64.40

16.90

1.86

1.37

1.13

2.60

5.79

4.56

.16

.39

.23

.02

None.

.21

.07

.27

.14

Trace

100. 10

c

63.24

17.98

2.67

.85

.63

.93

6.27

5.47

.37

.80

.38

Trace.

None.

.22

.04

.25

.03

.01

Trace.

Trace.

100. 14

H

61.28

14.71

1.21

2.85

1.69

5.61

2.99

7.70

.28

.43

.41

.16

.08

Trace.

.72

O4.

100. 16

D

67.53

18. 57

1.13

.08

.24

.55

11.50

.10

.15

.31

.07

.11

Trace.

Trace.

Trace.

Trace.

100. 34

I

61.65

15.07

2.03

2.25

3.67

'4.61

4.35

4.50

.26

.41

.56

.33

.09

.27

.10

100. 15

E

63.01'

18. 47

.06

.32

.06

2.66

10.01

.39

.05

.27

.13

2.01

.06

.

.06

.02

Trarp

.01

2.10

99.69

J

59.79

17.25

3.60

1.59

1.24

3.77

5.04

5.05

1Q

.39

.67

.72

.35

.04

5>n

.14

.11

Tropp

100.14

F

57.73

IK 03

1 Q7

"I 09

01

2.78

5.52

6.11

.22

9 03

qq

Trarp

.26

.25

.06

.16

00

.01

Trarp

M

100. 20

K

58.28

17 on

3.20

1.73

i "ii

Q (!Q

5

OQ

"l 34

.17

OR

.64

9fi

.06

.36

.05

Tnrf>

100. 05
436 DATA OF- GEOCHEMISTRY.

Analyses of trachyte-syenite rocks Continued. 

Norms.

Q.. .........................

ab ............................

ne........ ....................

ac......... ...................

di. ..........................

hy.............. ..............

of................ ..............

hm........ ...................

il.......... ..................

pr. ........................... 1

Q.... .........................

or............ .................

ab ...........................

an ...........................

ne. ..........................

ac ...........................

di............................

wo.. .......................... hv...................... :....

of ............................

11................ :............

A

8.8

 35:6

42 .4

3.6

3.4

2 4

2.1

.9

B

5.3

33.9

51.9

2.8

1.4

1.6

1.0

.3

G

7.1

27.2

48.7

6.7

5.2

.8

2.8

.5

C

2.8

32.8

52.9

4.4

1.6

1.6

1.6

.8

H

3.4

45.6

25.2

3.9

1G.O

1.9

1.6

.8

D

- 0.6

95.4

1.4

1.3

.5

.2

.5

I

6.2

26.7

36.7

8.3

11.9

5.0

3.3

1.1

E

2.2

83.3

4.4

.6

1.2

3.1

-

.3

2.1

J

3.1

30.6

42.4

9.5

6.7

3.2

1.4

1.2

.8

F

36.1

37.7

8.6

4.8

4.5

1.0

3.0

.6

K

31.7

41.9

6.4

4.3

8.0

4.6

1.2

.7

The rocks of this group, being deficient in quartz, tend to run 

lower in silica than the granites and rhyolites. Their magmatic 

range is between 1.5.1.3 and II.5.2.4; so that, despite their mineralogical similarities, they are divided- between two classes, but fall 

within each class into the same order, the perfelic. With decrease 

of quartz, at one end of the series, they shade into rocks in which 

the femic minerals are no longer subordinate. Among these femic 

rocks are found varieties which have been named minette, kersantite, 

lamprophyre, and shonkinite. Some of these terms are vaguely used, 

and are very often applied to rocks of a transitional character which 

contain considerable amounts of soda-lime feldspars. The subjoined 

analyses represent some of these femic syenites.
IGNEOUS ROCKS. 437

Analyses of femic syenites.

A. Soda minctte, Brathagen, Laugendal, Norway. Analysis by V. Schmelck. Described by W. C. 

Bro'gger (Die Eruptivgesteine des Kristianiagebietes, vol. 3, 1898, p. 130). Contains, in approximate 

percentages, 54 soda feldspar, 29 lepidomelane, 13 segirine-augite, 2J apatite, and 1 sphcne. Magmatic 

symbol, II.5.2.4. Akerose.

. B. Soda minette, Hao, Langesund Fjord, Norway. Analysis by Schmelck, description by Bro'gger 

(Die Eruptivgesteine des Kristianiagebietes, vol. 3, 1898, p. 139). Contains about 51J per cent soda feldspar, 26.5 lepidomelane, 16J diopside, 2f each of apatite and sphene. Symbol, II.C.1.4. Laurdalose. 

C. Syenitic lamprophyre, Two Buttes, Prowers County, Colorado. Analysis by W. F. Hillebrand. 

Contains, according to W. Cross, alkali feldspar, diopside, biotite, magnetite, and olivinc. Symbol, 

III.5.2.2. Prowcrsose. <,

D. Shonkinite, Beaver Creek, Bearpaw Mountains, Montana. Analysis by H. N. Stokes. Described 

by W. H. Weed and L. V. Pirsson. Contains anorthoclase, diopside, biotite, iron ores, and apatite, with 

a very little olivine and nephelite. Symbol, III.5.1.3. '

E. Shonkinite, Yogo Peak, Little Belt Mountains, Montana. Analysis by Hillebrand. Described by 

Weed and Pirsson. Contains augite and orthoclase, with biotite, iron ore, andesinc, apatite, olivine, and 

a trace of kaolin. Symbol, III.6.2.3. Shotikinose.

SiOo.. ................................

A1 263 ......... ........................

Fe203 .......................... .......

FeO

MgO.. ........ .........................

CaO. .................................

Na^O..... ............................ K26. ................................

H20................... ..............

H.,0+. ..............................

TiO,.... ..............................

coa :. ...............................

p2o5 --------- .........................

en

ci. ..................................

F....................................

V O N

Cr208 . ...............................

MnO............... .................

NiO..... .............................

BaO. .................................

SrO. ................................

Li20......... .........................

A

51.22

17.56

3.51

4.34

3.22

4.52

5.72

4.37

} 1.93

1.70

.60

1.08

.20

99.97

B

51. 95

14.95

4 OQ

5.70

3.54

6.10

5.43

4.45

| 1.10

1 O r>

1.15

Qfl

100. 71

C

50.41

12.27

5.71

3.06

8.69

7.08

.97

7.53

.46

1.80

1.47

.46

None.

Trace.

Trace?

.03

.15

.04.

.23

.06

Trace.

100. 42

D

50.00

0 87

Q AK

K m

11.92

8.31

2.41

5.02

.17

1.16

73

.31

.81

.02

.08

, .16

.11

Trace.

.07

.32

.07

Trace.

100. 01

E

48.98

19 9Q

9 8ft

5.77

9,19

9.65

2.22

4.96

9fi

.56

1.44

.98

.22

Trace.

.08

4*

.08

Trace

99.99

Norms.

or. ...............................'...

ne

di. ...................................

ol.... ................................

il... ..................................

hm ..................................

A

25.6

32.0

9.5

8.8

5.3

5.6

5.1

3.2

2.5

B

26.1

28.3

3.3

9.7

16.8

3.2

6.0

3.7

2.7

C

44.5

4.2

6.7

2.3

20.4

8.6

5.8

2.8

1.0

1.6

D

29.5

8.9

1.1

 6.2

28.9

14.8

5.1

1.4

1.7

E

9Q ^

5.3

8.6

6.8

26.5

11.7

4.2

2.6

2.2
438 DATA OF GEOCHEMISTRY.

A comparison of the norms under A and B with the modes as 

given by Brogger will show how widely the two diverge. These two 

rocks are in Class II; the others, on account of their higher proportion of femic minerals, fall in Class III. All five of the rocks contain 

micas, which accounts for some of the differences between the magmatic and the mineralogical composition. In A and B, also, sphene 

is reported, while in the norms the titanium is reckoned entirely as 

ilmenite.

NEPHELITE BOCKS.

In the norms of the foregoing rocks small quantities of nephelite 

appear. These mark a transition from the syenites and trachytes 

proper to the phonolites and nepheline syenites, in which the lenad 

minerals replace the alkali feldspars to a greater or less extent. 

Taking the nephelite rocks first in order, we find an eruptive and a 

deep-seated group, just as with the trachyte-syenite series. Quartz 

is excluded from these rocks, for if it were introduced in excess into 

the magma it would convert the lenads into feldspars, nephelite into 

albite, and leucite into orthoclase. In phonolite we have commonly 

orthoclase, nephelite, and pyroxene; tinguaite is a varietal name. 

Some rocks richer in femic minerals than the phonolites have been 

classed with the basaltic basanites, but they contain soiittle sodalime feldspar that it is well to include them in the following table, 

as allied to phonolite chemically. The subjoined data relate to 

members of the eruptive series.

Analyses of eruptive nephelite rocks.

A. Phonolite, Southboro, Massachusetts. Analysis by H. N. Stokes. Collected by B. K. Emerson 

but not described. Magihatic symbol, 1.6.1.4. Miaskose.

B. Phonolite, Black Hills, South Dakota. Analysis by W. F. Hillebrand. Described by W. Cross. 

Contains orthoclase, nephelite, aegirite, noselite, sodalite, sphene, apatite, and zircon; also secondary 

zeolites and calcite, but no magnetite. Symbol, 1.6.1.4. Miaskose.

C. Phonolite, Cripple Creek, Colorado. Analysis by Hillebrand. Described by Cross. Contains orthoclase, nephelite, sodalite, noselite, aegirite, etc. Symbol, 1.6.1.4. Miaskose.

D. Phonolite, Pleasant Valley, Colfax County, New Mexico. Analysis by Hillebrand. Keported by 

Cross to contain nephelite, alkali feldspar, segirite, traces of magnetite, and a little noselite or sodalite. 

Symbol, 1.6.1.4. Miaskose.

E. Tinguaite, Bear Creek, Bearpaw Mountains, Montana. Analysis by Stokes. Described by W. H. 

Weed and L.*V. Pirsson. Contains orthoclase, nephelite, cancrinite, augite, segirite, apatite, a little sodalite, and a doubtful hornblende. Symbol, II.6.1.3. Judifhose.

F. Phonolite, Uvalde County, Texas. Analysis by Hillebrand. Reported by Cross to contain orthoclase, nephelite, and segirite, with a very little hornblende, augite, and magnetite. Symbol, II.6.1.4. 

Laurdalose.

G. Basanitc, near Big Mountain, Uvalde County, Texas. Analysis by Hillebrand; description by Cross. 

Contains alkali feldspar, augite, magnetite, olivine, nephelite, segirite, biotite, and zeolitic minerals. 

Symbol, II.6.2.4. Essexose.

H. Basanitc, Mount Inge, Uvalde County, Texas. Analysis by Hillebrand; description by Cross. 

Contains orthoclase, nephelite, hornblende, augite, segirine-augite, olivine, magnetite, apatite, and a 

trace of pyrite. Symbol, II.7.1.4. Lujavrose.
IGNEOUS ROCKS.

Analyses of eruptive nephelite rocks Continued.

439

Si02 ...... ......-..-

AlaO....... ..........

Fe203 ... ...... .......

FeO

MgO.. ....... ........

PoD

Na.0..... ...........

rr A

H n

H20+......... .......

TSO

V..A

rrv

P205 -----------------

9O

F..... ................

vao,.- -- .........

MnO........... ......

NiO. ................

BaO. ................

<5vA

Li20.. ....... ........

A

54.22

20.20

2.35

1.02

.29

.70

9.44

4.85

 .42

5.57

.38

.11

None.

.19

Trace.

99.74

B

57. 86

20.26

2.35

.39

.04

.89

9.47

5.19

.21

2.40

.22

.15

.03

.06

.03

.08

(?)

.21

.09

.04

Trace.

99.97

c

58.98

20.54

1.65

.48

.11

.67

9.95

5.31

.19

.97

.24

.20

.04

.20

.28

.26

None.

None.

Trace.

100.07

D

56.24

21.43

2.01

.55

.15

l.*38

10.53

5.74

.12

.86

.26

.09

.06

.10

.03

.12

Trace.

.08

None.

.08

.03

Trace.

99.86

E

57.46

15. 40

4.87

.87

1.37

2.59

5.48

9.44

.09

.82

.60

.13

.21

.13

.20

Trace.

Trace.

.60

.16

Trace.

100. 42

F

54.42

20.76

2.64

1.33

.22

1.34

10. 41

4.89

.22

2.50

.40

.15

.11

.6i

.23

None.

.15

.04

Trace.

Trace.

99.82

G

48.23

17. 43

2.77

5.92

2.99

6.38

6.87

2.78

.54

2.84

2.00

.04

.69

.08

.03

.04

.18

Trace.

.08

.08

Trace.

99. 97

H

48. 13

18. 44

3.41

4.30

3.06

5 on

8.00

3.80

.18

1. 59

1.74

AC

40

00

oq

.06

1Q

09

.10

.10

Trace*

99.93

Norms.

-

or............-...----

oh

ne

QA

ac

di:.... ..............

ol... ................

int. ..................

il.. ....... ...........

at) . .. .. . .........

A

28.9

33.5

23.3

2.8

1.5

.6

2.1

.8

B

30.6

39.3

19.0

4.2

1.9

1.2

,

C

31.1

38.3

17.2

3.9

4.6

2.6

D

33.9

22.0

32.7

.6

2.9

1.5

E

55.6

5.8

9.9

2.9

13.8

8.0

1.0

1.2

F

29.5

23.6

30.4

7.4

4.9

.6

.8

G

16.7

23.6

8.3

18.7

15.9

3.7

q Q

3.7

c>

H

22.2

14.1

3 1

9Q 0

18.6

.8

4.9

3.4

1.1
440 DATA OF GEOCHEMISTRY.

The following table contains analyses of deep-seated rocks of the 

nephelite series:

Analyses of deep-seated nephelite rocks.

A. Elzeolite syenite, or litchfieldite, Litchfield, Maine. Analysis by L. G. Eakins. Described by W. S. 

Bay ley. Contains elaeolite, two feldspars, and lepidomelane, with accessory sodalite, cancrinite, and 

zircon. Magmatic symbol, 1.5.1.4. Nordmarliose.

B. Elseolite syenite, Beemersville, New Jersey. Analysis by Eakins. Described by J. P. Iddings. 

Contains nephelite, orthoclasc, cegirite, and biotite, with less melanite, titanite, apatite, magnetite, and 

zircon. Symbol, 1.5.6.3. Beemerose.

C. Nephelite syenite, Brookville, New Jersey. Analysis by G. Steiger. Described by P. L. Ransome. 

Contains alkali feldspars, altered nephelite, amphibole, biotite, cancrinite, plagioclase, muscovite, segirineaugite, apatite, fluorite, and traces of magnetite, with secondary analcite, sericite, and natrolite (?). 

Symbol, 1.6.2.4. Viezzenose.

D. Elseolite syenite, Red Hill, Moultonboro, New Hampshire. Analysis by W. F. Hillebrand; description by Bayley. Contains elseolite, hornblende, augite, biotite, sodalite, albite, and orthoclase, with, 

accessory apatite, sphene, magnetite, and an occasional zircon. Symbol, 11.5.1.4. Umptekose.

E. Nephelite syenite, Cripple Creek, Colorado. Analysis by Hillebrand. Described by W. Cross. 

Contains alkali feldspars, nephelite, sodalite, augite, some segirine, hornblende, biotite, sphene, apatite, 

and magnetite. Symbol, II.5.2.4. Akerose.

F. Urtite, Kola Peninsula, Finland. Analysis by N. Sahlbom. Described by W. Ramsay, GeoL 

Foren. Forhandl., vol. 18, p. 463,1896. Contains, in percentages, nephelite, 85.7; pyroxene, mostly ajgirite, 

12.0; and apatite, 2.0. Symbol, II.9.1.4. Urtose.

G. Ijolite, livaara, Finland. Analysis by A. Zilliacus. Described by W. Hackman, Bull. Comm. ge"ol. 

Finland, No. 11. 1900. Contains, in average percentages, nephelite, 51.6; pyroxene, 39.2; apatite, 4.3; 

titanite, 2.1; and ivaarite, 0.7. Symbol, II.9.1.4. Urtose.

H. Theralite, Crazy Mountains, Montana. Analysis by Hillebrand. Contains, according to J. E. 

Wolff, augite, aegirite, biotite, sodalite, nephelite, feldspar, apatite, magnetite, and titanite. Symbol, 

III.7.1.4. Malignose.

SiO

Al ft

Fe203 .. ....... .......

FeO

MgO.. ...... .........

CaO.... .............

Na/).... ............

K20. .................

H20 ................

H20+.. ..............

Tift

co 2

pao6 .. ....:.. ........

F..8 ................. ci....................

MnO.................

BaO.................

SrO..................

V208 ....... .........

2

A

60.39

22. 57

.42

2.26

.13

.32

8.44

4.77

\ 57 r - d '

.08

99.95

B

53. 56

24. 43

2.19

1 22

.31

1.24

6.48

9.50

} .93

.......

.10

99.96

C

54.68

21. 63

2.22

2.00

1.25

2.86

7.03

4.58

.27

1.88

.79

.28 

.07

.22

Trace.

.05

99.81

D

59.01

18.18

1.63

3.65

1.05

2.40

7.03

.15

.50

.81

]2

Trace.

.03

.08

Trnrp

99.98

E

54.34

1Q 91

3.19

9 11

1.28

4 53

6.38

5.14

.14

1.17

1 OQ

.07

NOTIG

.27 

.07

.28

.08

94

.16

.02

TVaro

99.77

*'

45.28

97 37

3 ^3

4Q

qq

1 99

17 9Q

3 ^1

} .40

.......

IQ

99.61

« 

43. 02

24.63

3 ^Q

917

1 Qfi

5.47

14.81

9 QQ

/ *o

.70

99.97

H 

44 fi^

1 ? Q7

6.06

2,94

K 1 C

0 t;«r

5. 67

4 4Q

Qft

9 ]Q,

Q'v

.11

1.50 

.61

Trace.

.17

*?£

37

T

99.93
.IGNEOUS ROCKS. 441

Analyses of deep-stated nephelite rod's Continued.

Norms.

ab....................

an....................

lc... ................

lip

Irn

no................. ... .

C....................

ac....................

11O

di..... ..............

\vo...................

ol... ................

mt.. .................

il... ................. p.----.---

A

28.4

52.4

1.7

10.2

2.9

3 1

.7

B

56.2

3.4

6.1

27.5

1.3

.9

3.2

C

27.2

35.6

14.2

12.8

2.6

3.2

1.5

D

31.7

41.9

2.2

9.9

8.2

1 Q

2.3

1.5

E

30.6

34.1

9.2

6.0

9 Q

6.9

1.3

4.6

9 0

.7

F

16.1

65.0

10.2

3.4

3.4

.8

0

9.6

59.4

3.2

10.2

1.0

5.8

8.2

1.1

1.7

H

26.7

2.6

1.1

18.5

5.0

27.9

.2

6.6

1.4

1.8

3.5

A comparison of these norms with the modes indicated in the descriptions of the rocks shows great divergencies. The normative and 

actual minerals are only in part the same. All of the rocks, however, 

consist dominantly of alkali feldspar and nephelite, with varying 

accessories. In the Brookville syenite the normative anorthite shows 

a gradation toward the plagioclase rocks. The urtite and ijolite represent the highest proportions of nephelite; and in the theralite we 

have the femic minerals forming nearly one-half of the rock. Taken 

all together, the nephelite rocks, eruptive and plutonic, range from 

1.5.1.4 to III.7.1.4. The mineralogical variations are great enough 

to justify a much more minute subdivision in classification than they 

are given here. The many varietal names that have been given the 

nepheline syenites follow from a recognition of their differences. 

Ditroite, foyaite, laurdalite, litchfieldite, urtite, and ijolite are examples of this varied nomenclature.1

1 A very full description of the Norwegian nepheline syenites is given by W. C. Brb'gger in his work Die 

Eruptivgesteine des Kristianiagebietes, especially in part 3 (1898). Laurdalite, heumite, nepheline porphyry, foyaite, and hedrumite are the nephelite rocks described in this memoir. A remarkable rock 

found in Dungannon Township, Ontario, has been described by F. D. Adams, Am. Jour. Sci., 4thser., 

vol. 17,1904, p. 269. It contains 72.2 per cent of nepheh'te, with 15.09 of hornblende and 5.14 of cancrinite. 

Some minor constituents are also present. This rock Adams has named monmouthite, and its norm 

differs widely from its mode. On the origin of "alkaline" rocks see H. I. Jensen, Proc. Linn. Soc. New 

South Wales, vol. 33, 1908, p. 491: R. A. Daly, Bull. Geol. Soc. America, vol. 21,; 1910, p. 87; and C. H. 

Smyth, jr., Am. Jour. Sci., 4th ser., vol. 3C, 1913, p. 33.
442 DATA OF GEOCHEMISTRY.

LETJCITE ROCKS.

The leucite-bearing rocks are much less common than those carrying nephelite, and, like the latter, have been designated by various 

names. The following examples among those containing little or no 

soda-lime feldspar will suffice to show their composition:

Analyses ofleudte rocks.

A. Pseudoleueite-sodalite tinguaite, Bearpaw Mountains, Montana. Analysis by H. N. Stokes. Described by W. H. Weed and L. V. Pirsson. Contains orthoclase, nephelite, sodalite, noselite, rcgirtte, 

diopside, and fluorite. Magmatic symbol, II.7.1.3. Janeirose. Although leucite is not reported here, it 

appears abundantly in the norm.

B. Arkite, or leucite syenite, Magnet Cove, Arkansas. Described aiid analyzed by H. S. Washington, 

Jour. Geology, vol. 9,1901, p. 616. Contains, in percentages, orthoclase, 3.9; leucite, 30.9; nephelite, 25.5; 

fegirite, 8.4; diopside, 10.8; garnet, 14.5. Symbol, II.9.1.3. Arkansose.

C. Wyomingite, Boar's Tusk, Leucite Hills, Wyoming. Analysis by W. P. Hillebrand. Described 

by W. Cross. Contains phlogopite, leucite, diopside, and apatite. Symbol, III.G.1.1. Wi/omingose.

D. Leucitite, Bearpaw Mountains, Montana. Analysis by Stokes. Described by Weed and T'irsson 

as an olivine-free leucite basalt. Contains leucite, augite, iron oxides, rarely biotite, and a little glassy 

base. Symbol, III.8.1.2. Chotose.

E. Leucitite, Alban Hills, Italy. Described and analyzed by Washington, Am. Jour. Sci., 4th ser., 

vol. 9,1900, p. 53. Contains leucite, nephelite, melilite, diopside, magnetite, a trace of biotite, and scarcely 

any apatite. Symbol, III.8.2.2. Albanose.

F. Madupite, Leucite Hills, Wyoming. Analysis by Hillebrand. Described by Cross. Contains 

diopside and phlogopite, with perof skite and magnetite, in a glassy base of nearly the composition of leucite. 

Symbol,'III.9.1.2. Madupose.

G. Missourite, Highwood Mountains, Montana. Analyzed by E. B. Hurlbut. Described by Weed 

and Pirsson in Bull. U. S. Geol. Survey No. 237, 1905. Contains leucite, augite, biotite, olivine, apatite, 

iron ore, some zeolites, and analcite. Symbol, IV.1.1.2. In this rock, as the symbol indicates, femic 

minerals are dominant.

SiOo................

AlA. ...............

Fe208 .. .............

FeO

MgO................

CaO.. ...............

N&zO. ..............

K20.. ...............

H f\ 2u-. ..............

H20+. ..............

Ti02 . ...............

Zr02 . ...............

C03 .......... '.......

P (1 &£:.::::::::::::::: ci....................

F.. ..................

CraO.................

Di,03 ... v............

MnO................

NiO. ................

BaO................

SrO. ................

Li20................

A

51.93

20.29

3.59

1 9fi

.22

1.65

8.49

9.81

.10

.99

.20

.25

.06

.67

.70

.27

Trace.

ftQ

.07

 Trace.

100. 58

B

S

44.40

19.95

5.15

2.77

1.75

8.49

6.50

8.14

.24

1.17

1.53

.03

.12

.37

.06

.08

.01

100. 76

c

50.23

11.22

3.34

1.84

7 OQ

5.99

1.37

9.81

Q3

1 79

2.27

1.89

.74

.03

.50

.10

.03

.05

1 93

24

Trace.

100. 62

D

46.51

11.86

7.59

4 3Q

4 7^

7.41

2.39

8.71

1.10

9 4^

. .83

.80

.05

.04

Trace.

.02

.04

en

.16

TVirp

99.78

E

45.99

17.12

4.17

5.38

5.30

10.47

2.18

8.97

.45

.37

Trace.

OK

Wrnio

100. 65

F

42.65

9.14

5.13

1.07

10.89

12.36

.90

7.99

2.04

2.18

1.64

1.52

.58

.03

.47

.07

.11

.12

on

.33

Trarp

100. 11

C,

46.06

10.01

3.17

5.61

14.74

10.55

1.31

5.14

} 1.44

.73

.21

.05

.03

Trace.

.32

.20

99.57
IGNEOUS ROCKS.

Analyses of leucite rocks Continued.

Norms.

443

or...................

Ic. ...................

so ...................

no...................

ac... ................

cli. .................

ol.. ..................

am..................

mt. .................

hm.. ................

il...................

0 r\ ap... ................

ft....................

A

33.9

18.7

9.8

5.3

10.2

5.7

.5

B

1.1

37.9

29.8

9.6

12.0

4.9

1.8

9 ft

C

44.5

10.5

1.7

7.4

13.9

7 Q

.8

4.1

4.5

D

7.8

34.0

10.8

6

0

25.1

2.5

7.4

1.5

1.9

E

10.6

41.4

9.9

12.0

9.7

9.7

6.0

.8

F

37.1

3.5

22.6

11.7

8.2

5.1

2.7

3.7

.7

G

1.1

6.1

23.1

6.0

37.4

17.7

4.6

1.2

It is worthy of note that there are many rocks specifically designated as leucite-bearing which, as interpreted by Washington, reveal 

no leucite in the norms.1 It is also to be observed that the leucite 

rocks are all effusive and never deep seated; at least no plutonio 

member of the group is known. In an abyssal rock, which has consolidated under pressure, water is retained; and in such cases, when 

magnesium and potassium available for the formation of olivine and 

leucite are present, biotite is produced instead. Under ordinary circumstances the fusion of biotite yields olivine, leucite, some glass, 

and a little spinel.2 By fusing biotite and microcline together, 

Fouque and Le"vy 3 obtained a mixture of leucite, olivine, and magnetite, together with a mineral resembling melilite, which, however, 

could not be that species. A magma, then, which would form 

biotite under pressure, will lose water if it solidifies at the surface 

of the earth, and may generate olivine and leucite.

The other lenad minerals, sodalite, noselite, and haiiynite, are also 

noteworthy constituents of certain rare rocks, which we need not 

consider in detail. Sodalite syenite, haiiynophyre, and nosean sanidinite are names of rocks in which these minerals are conspicuous.4

One sodalite syenite, however, is included in the next table of 

analyses, for the reason that it also contains analcite, a rock-making 

mineral whose significance has been realized only within recent years.

» On the formation of leucite in igneous rocks, see H. S. Washington, Jour. Geology, vol. 15,1907, pp. 257; 

357. Also in his Roman comagmatic region, Pub. No. 51 Carnegie Inst., Washington, 1900.

» See H. Backstrom, Geol. Foren. Forhandl., vol. 18,1896, p. 155.

* Synthese des min<5raux et des roches, p. 77.

< For analyses see Wa'shington's Tables, Prof. Paper U. S. Geol. Survey No. 99,1917, pp. 287, 307, 319, 

323,439, 571, 573,583, 675.
444 DATA OF GEOCHEMISTRY.

ANALCITE BOCKS.

The occurrence of analcite as a primary mineral was first recognized by W. Lindgren,1 who described certain rocks from Montana 

as analcite basalts. In them the analcite played a part like that 

usually taken by the feldspars. Since then the mineral has been 

identified in a considerable number of other rocks,2 and W. Cross 3 

has found it to be commonly present in the phonolites of Cripple 

Creek. According to L. V. Pirsson,4 the supposed "glass base" of 

monchiquite is really analcite. This rock was originally described 

by M. Hunter and H. Rosenbusch 5 as consisting of olivine, with 

either amphibole, pyroxene, or biotite, or all three, in a glassy groundmass; but the composition of the latter is that of analcite, and like 

analcite it gelatinizes with weak acids. In a magma having the 

general composition of a nepheline rock, the presence or absence 

of water is an important, factor. If water is retained, analcite is 

likely to be formed; if lost, then nepheline is generated. Analcite, 

however, is more nearly akin, structurally, to leucite than to nephelite, and between the leucite and analcite rocks there are strong 

resemblances. The folloxving analyses represent the last-named rock

family: 6

Analyses of analcite rocks.

A. Sodalite syenite, Square Butte, Highwood Mountains, Montana. Analysis by W. H. Melville. 

Described by W. Lindgren, Am. Jour. Sci., 3d scr., vol. 45,1893, p. 286. Contains, in percentages, orthoclasc, 50; albite, 16; hornblende, 23; sodalite, 8; analcite, 3. Magmatic symbol, 1.5.2.3. Pulaskose.

B. Analcite tinguaite, Manchester, Massachusetts. Analyzed and described by H. S. Washington, Am. 

Jour. Sci., 4th ser., vol. 6,1898, p. 182. Contains, in percentages, analcite, 37.4; albite, 20.9; nephelite, 10.9; 

orthoclase, 17.3; ajgirite, 10.2; pyroxene, 3.3. Symbol, 1.6.1.4. Miaskose.

C. Heronite, Heron Bay, Lake Superior. Analysis by H. W. Charlton. Described by A. P. Coleman, 

Jour. Geology, vol. 7, 1899, p. 431. Contains, in percentages, analcite, 47.0; orthoclase, 28.24; labradorite, 

13.0; segirite, 4.04; limonite, 3.59; calcite, 1.96. Symbol, 1.6.1.4. Miaskose.

D. Monchiquite, Little Belt Mountains, Montana. Analysis by H. N. Stokes. Described by TV. H. 

Weed and L. V. Pirsson. Contains olivine, augite, biotite, analcite, and apatite, with traces of serpentine 

and chlorite. Symbol, III.6.1.4. No subrang name assigned. Called analcite basalt in Washington's 

tables.

E. Monchiquite, Cabo Frio, Brazil. Described by Hunter and Rosenbusch, Min. pet. Mitt., vol. 11. 

1890, p. 445. Analysis by M. Hunter. The type of monchiquite, as described above. Symbol, III.6.2.4. 

Moncliiquose.

F. Monchiquite, Big Baldy, Little Belt Mountains, Montana. Analysis by W. F. Hillebrand. Described by Weed and Pirsson. Contains pyroxene, a few serpentinized olivines, iron ore, and apatite, in a 

base of analcite. Symbol, III.6.2.4. Monchiguose.

G. Monchiquite, Highwood Mountains, Montana. Analysis by H. W. Foote. Described by Weed and 

Pirsson. Contains augite, olivine, biotite, iron ore, apatite, and analcite, with some serpentine and a little 

kaolin. Symbol, III.6.2.4. Monchiguose.

H. Analcite basalt, near Cripple Creek, Colorado. Analysis by Hillebrand. Described by W. Cross. 

Contains augite, olivine, analcite, alkali feldspars, biotite, and apatite. Symbol, in.6.2.4. Monchiquose.

1 Proc. California Acad. Sci., 2d scr., vol. 3,1891, p. 51' 

. 2 See citations under analcite in Chapter X, ante, p. 363.

»Sixteenth Ann. Rept. TJ. S. Geol. Survey, pt. 2,1896, p. 32.

«Jour. Geology, vol. 4,1896, p. 679.

s Min. pet. Mitt., vol. 11,1890, p. 454.

6 On the analcite rocks of Sardinia, see H. S. Washington, Jour. G eology, vol. 22,1914, p. 742. A remarkable rock, blairmorite, containing 71 per cent of analcite, found near Crowsnest Pass, Alberta, is described 

by J. D. MacKenzie, Dept. Mines, Canada, Museum Bull. No. 4,1914. Analysis by M. F. Connor on p. 23,.
IGNEOUS ROCKS.

Analysts of analcite rocks Continued.

445

Si02 ................

AloOg................

Fe203 .. ..............

Feb

MgO. ........ ........

CaO................. 

Na,0................

K,0.................. ru)-................

n;o+................

TiO,.. ...............

ZrCv. ...............

CO....................

PO&&".v:::::::::::::

01....................

F...................

Pr O

MnO.................

NiO.. ...............

BaO........ .........

SrO..................

Li 20.................

A

56.45

20.08

1.31

4.39

.63

2.14 

5.61

7.13

.26

1.51

.29

.13

.43

.09

Trace.

100.45

B

56.75

20.69

3.52

.59

.11

.37 

11.45

2.90

.04

3.18

.30

Trace.

.28

Trace.

None.

100. 18

0

52.73

20.05

3.43

.99

.17

3.35

7.94

4.77

.69

4.85

.93

Trace.

.11

100. 01

D

48.39

11.64

4.09

3.57

12. 55

7.64 

4.14

3.24

.28

2.56

.73

.45

.08

Trace.

.07

Trace.

.32

.15

Trace.

99. 90

E

46.48

16 J 6

6.17

6.09

4.02

7.35 

5.85

3.08

] 4.27

.99

.45

100. 91

F

48. 35

13.27

4.38

3.23

8.36

9.94 

3.35

3.01

.90

2.89

.52

.30

.40

.25

Trace.

.19

.04

.54

.09

Trace.

100. 01

G

47. 82

13. 56

4.73

4,54

7.49

8.91 

4.37

3.23

| 3.37

.67

1.10

Trace.

.04

.16

21

100. 20

H

45. 59

12. 98

4.90

4.77

8.36

11.09 

4.53

1.04

.51

3.40

1.32

.03

.91

.05

.14

.13

.12

99. 87

Norms.

ab. ...................

at \

ac....................

di....... ............

wo............ .......

ol... ................

rat........... ........

il. ...................

ap....................

A

41.7

28.3

10.6

3.4

5.9

6.1

1.9

.6

B

17.2

46.6

23.6.

6.6

.5

.5

2.6

C

28.4

30.9

5.0

19.6

3.0

4.4

3.2

1.1

D

18.9

14.7

3.6

11.1

24.4

15.2

5.8

] 4

1.1

E

18. 3

14.1

8.6

19.0

22.3

2.9

9.0

1.8

F

17.8

14.7

12.2

7.4

.27.2

6.7

7.2

.9

1.0

G

18.9

17.8

7.8

10.5

23.9

7.4

8.0

1.2

2.5

H

6.1

18.9

12.2

10.2

30.0

6.5

7.2

2.5

1.9

In these norms analcite is represented by normative nephelite; and 

biotite, in part, by olivine. The anorthite in some of them indicates 

a shading toward the plagioclase rocks.
446 DATA OF GEOCHEMISTRY. 

THE MONZONITE GROUP.

The rhyolite-granite series of rocks, and the trachyte-syenite series 

also, are defined by the predominance in them of alkali feldspars, and 

commonly of orthoclase. The andesite-diorite series, on the other 

hand, is characterized by plagioclase feldspars; but between these 

rocks and those already described there are all sorts of gradations.

Between the orthoclase and plagioclase rocks, therefore, considerations of convenience have led to the formation of an intermediate 

group, whose granitoid members are known as monzonites. Quartz 

monzonite corresponds to granite, monzonite to syenite, and so- on.' 

The effusive equivalents, intermediate between trachyte and andesite, 

have been named latites. All these rocks cany orthoclase or 

anorthoclase with plagioclase in approximately equal amounts, with 

or without quartz, and with smaller amounts of the ferromagnesian 

silicates. The next tab.le of analyses represents members of this 

intermediate: group.

Analyses of monzonites and latites.

A. Quartz monzonite, Hailey, Idaho. Analysis by W. F. Hillebrand. Described by W. Lindgren. 

Contains quartz, orthoclase, microcline, oligoclase, biotite, apatite,, titanite, and magnetite. Magmatic 

symbol, 1.4.2.3. Tbscanose.

B. Quartz monzonite, Telluride quadrangle, Colorado. Analysis by H. N. Stok'es. Described by W. 

Cross. Contains orthoclase and plagioclase in nearly e'qual amounts, quartz, augite, hornblende, biotite, 

magnetite, and apatite. Symbol, 1.4.2.3. Toseanose.

C. Biotite-augite latite, near Clover Meadow, Tuolumne County, California. Analysis by Hillebrand. 

Described by F. L. Ransome. Contains plagioclase, biotite, augite, magnetite, apatite, and glass. Symbol, 

1.4.2.3. Toseanose.

D. Monzonite, Tintic district, Utah. Analysis by Stokes. Described by G. W. Tower and G. O. Smith. 

Contains orthoclaser plagioclase,. quartz, hornblende,, biotite, magnetite, apatite, zircon, and titanite, with 

a little chlorite and cpidote. Symbol, II.4.3.3. Harzose.

E. Monzonite (yogoite), Yogo Peak,, Little Belt Mountains, Montana. Analysis by Hillebrand. .Described by W. B. Weed and L. V. Pirsson. Contains orthoclase, oligoclase, pyroxene, hornblende, biotite, 

apatite, titanite, iron ore, and a little kaolin. Symbol, II.S.2.3. Monzonose.

F. Augite latite, DardanelQe flow, Tuolumne County, California. Analysis by Stokes. Described by 

Ransome. Contains plagioclase, augite, iron ore, some olivine, apatite, and brown glass. Symbol, II.5.2.3. 

Monzonose.

G. Augite latite, Table Mountain, Tuolumne County, California. Analysis by Hillebrand. Described 

by Eansome. Contains labradorite, olivine, augite, and magnetite. Symbol, II.5.3.3. Shoshonose.

H. Monzonite, La Plata Mountains, Colorado. Analysis by Stokes. Described by Cross. Contains 

orthoclase and plagioclase in nearly equal amounts, augite,.hornblende, quartzite, titanite, magnetite, and 

apatite. Symbol, II.5.3.4, Andose.
IGNEOUS ROCKS.

Analyses ofmonzonites and latites Continued.

447

Si02 .......... .......

A\,0Z ...... .......... FC'A......... .......

FeO............ ......

MgO.... .............

CaO..... ..........:.

Na.0................

KoO.................. H;O................. H;O+................

TiO

ZrO... ...............

co2 :. ................ Pod **?:::::::::. :.::::::

S03 . ................

Cl....................

V20V --------------- Mnd... .............

BaO..... .............

SrO.. ................

Li20.................

FeS,.... .............

C... ".................

A

68.42

15.01

.97

L93

L-21

2.60

3.23

4 25

.54

.73

.50

.20

.13

.02

.06

.12

.03

99.95

B

65.70

15. 31

2.54

1.62

1.62

2.56

3.62

4.62

.17

.42

.72

None:

.33

.12

.03

Trace.

.12

.03

Trace.

99.53

c

62. 33

17. 30

3.00

1.63

1.05

3.23

4.21

4.46

.44

.75 i 0s;

.04

.29

.01

.08

.24

.05

Trace.

.06

.11

100. 33

D

59.76

15.77

3.77

3. 30

2.16

3.88

3.01

4.40

.31

1. 11

07

.78

.42

None.

.04

.02

.12

.09

Trace.

Trace.

99.81

E

54.42

14. 28

3.32

4.13

6.12

7.72

3 44

4.22

22

.38

OA

.59

<?>

.10

.32

.13

Trace.

100. 19

F

59. 43

16.68

2.54

3.48

1.84

4.09

3.72

5.04

.27

.72

 i qo

.08

.58

.05

Trace.

.14

Trace.

None.

100. 04

G

56. 19

16. 76

3.05

4.18

3.79

6.53

2.53

4.46

.34

.66

fiQ

.55

.10

.19

Trace.

100.02

H

57.42

18.48

3.74

2.10

1.71

6.84

4.52

3.71

.08

.28

.86

None.

.36

None.

.03

.09

.15

.08

Trace.

100. 45

Norms.

Q... .. ......

or. ...................

ab ....................

an................. . . .

C......... ...........

di..... ..............

hy..................

int........... ........

hm...............

il............. .......

A

25.1

25.6

26.7

13.1

.3

5.0

1.4

.9

B

19.1

27.2

30.4

12.1

.4

4.1

3.5

1.4

C

104

26.7

35.6

15.0

.8

2.3

2.1

1.6

2.0

D

14.6

26.1

24.1

16.7

2.4

5.8

5.6

1.7

E

25.0

28.8

11. 1

19.1

9.9

2.6

1.5

1.3

F

8.4

- 29.0

30.9

13. 9

2.3

5.8

3.5

2.6

1.4

G

5.9

26.7

21.5

20.9

6.8

10.1

4.6

1.2

1.2

H

4.0

21 7

37.7

20.0

8.7

5.3

1.5

1.0
448 DATA OF GEOCHEMISTRY.

THE ANDESITE-DIOBITE SERIES.

From the monzonite group to the dacites and quartz diorites the 

gradation is very slight. These rocks, which mark the persilicic end 

of the andesite-diorite series, are characterized by quartz, with 

plagioclase as the prevailing feldspar, and with subordinate amounts 

of femic minerals. The dacites are eruptive rocks; the quartz 

diorites are their granitoid or plutonic equivalents. They correspond 

to rhyolite and granite in the orthoclase series, and between dacite 

and quartz diorite there are porphyritic forms analogous to the 

quartz porphyries. For dacites and quartz diorites a single group of 

analyses must suffice, as follows:

Analyses of dacites and quartz diorites.

A. Dacite, Bear Creek Falls, Shasta County, California. Analysis by R. B. Riggs. Described by J. S. 

Diller. Contains plagioclase, with a little sanidine, hornblende, quartz, magnetite, some pyroxene inclusions, and glass. Magmatic symbol, 1.4.2.4. Lasscnose.

B. Quartz diorite, near Enterprise, Butte County, California. Analysis by W. F. Billebrand. Reported 

by H. W. Turner to contain plagioclase, potash feldspar, quart./., hornblende, mica, and accessories. Symbol, 1.4.2.4. Lassenose.

C. Dacite, Sepulcher Mountain, Yellowstone National Park. Analysis by J. E. "Whitfield. Described 

byj. P.Iddings. Contains plagioclase, quartz, biotite, and hornblende. Symbol, 1.4.3.4. Yellowstonosc.

D. Quartz diorite, Pigeon Point, Minnesota. Analysis by Hillebrand. Described by W. S. Bayley. Contains feldspar, quartz,hornblende, chlorite,magnetite,apatite,andrutile. Symbol, IT.4.2.3. Adamello;e.

E. Quartz-mica diorite, near Milton, Sierra County, California. Analysis by Hillebrand. Described 

by Turner. Contains plagioclase, quartz, hornblende, brown mica, iron ore, and apatite. Harzose.

F. Quartz-mica diorite, Electric Peak, Yellowstone National Park. Analysis by Whitfield. Described 

by Iddings. Contains plagioclase, orthoclase, quartz, biotite, hornblende, augite, and hypersthene. 

Symbol, II.4.3.4. Tonalose.

G. Quartz-mica diorite, Yaqui Creek, Mariposa County, California. Analysis by G. Steiger. Described 

by Turner. Contains plagioclase, quartz, biotite, hornblende, a little pyroxene, iron ore, and apatite. 

Symbol, II.4.3.4. Tonalose.

H. Quartz-mica hornblende diorite, Stone Run, Cecil County, Maryland. Analysis by Hillebrand. 

described by A. G. Leonard. Contains hornblende, biotite, quartz, plagioclase, a little orthoclase, zircon, 

apatite, titanite, and magnetite, with secondary chlorite and epidoto. Symbol, II.4.4.3. Bandose.

SiO........ ..........

Al,0,----------------

Fe2 03 ................

Feb................

MfO

CaO.................

NaaO. ...............

KaO........ '........

H20...............

H?0+. ....... .....:

TiO......... .........

ZrO" ................

C02 . ...............

P205 ----------------- s6,f.. .............. ci............ ......

v2o3 - ...............

MnO...............

BaO... ..............

SrO................

LiaO.. ...............

C............ ........

A

68.10

15.50

3.20

.10

3.02

4.20

3.13

2.72

.15

.03

Trace.

.06

100. 21

B

70.36

15. 47

.98

1.17

.87

3.18

4.91

1.71

.06

1.00

.20

.11

.06

Trace.

Trace.

100. 08

C

65.66

15.61

2.10

9 07

2.46

3.64

3.65

2.03

| 1.07

1.37

~n

.12

.36

100. 27

D

57.98

13.58

3. 11

8.68

2.87

2.01

3.56

3.44

} 2.47

1.75

.29

Trace.

.13

.04

Trace.

Trace.

99.91

E

57.26

6.51-

3.27

"S 1Q

3.41

6.69

2.65

2 Q3

.20

.95

.53

.30

.18

.10

.06

Trapp

100. 23

F

65.11

16. 21

1.06

3.19

2.57

3.97

4,00

2.51

} - 94

.71

.02

Trace.

.04

100. 33

G

58.09

17.46

119

5.08

4.06

6.24

9 Q4

2.02

.29

1.45

.95

.21

.17

.05

.02

TXTrmo

.07

.04

ISTnTip .11

100. 37

H

58.57

16. 10

2 CQ

fi 19

9 W

7 3Q

2.11

1.01

.21

1 97

1.41

.09

None

.37

.02

.18

Trace.

Trace.

Trace

100. 07
IGNEOUS ROCKS. 449

Analyses of dacitcs and quartz dioritcs Continued'.

Norms.

 Q.. ................

or. .................

ab. .................

 an. .................

C....................

di..... ..............

by..................

int. ................

hra .................

il....................

tn ..................

A

"25.4

38.3

35.6

H o

.7

3.2

.4

B

27.1

].0.0

41 4

15.3

3.1

1.6

.5

C

25..0

]2 2

30.9

18.1

.7

f> 9

2.8

2.6

r>

ll.l

20.0

29.9

10.0

.5

17.7

8.0

3.4

E

10.3

17 9

22.5

24.5

7.3

10.9

4.6

1. 1

F

18.5

15.0

33.5

18.9

.8

9.7

1.6

1.4

a

11.2

19 9

24 fi

28.4

2 1

16.0

1.6

1.8

H

91 ^

6

1

17.8

31 4

4.5

10.0

4.2

2.8

With these rocks it must be borne in mind that normative orthoclase in part represents biotite. The actual orthoclase, therefore, will 

be less in amount than appears in the norms.

Dacite is a quartz andesite; and the andesites which are poor or 

lacking in quartz form a group of rocks parallel with the trachytes. 

They contain plagioclase as a principal constituent, with subordinate 

biotite, hornblende, or pyroxene. Six analyses of andesites are given 

in the next table.

113750° 19 Bull. 695 29
450 DATA OF GEOCHEMISTRY.

Analyses of cndesites. 

A. From Pikes Peak, Colorado. Analysis by W. F. Hillebrand. According to W. Cross, it contains 

plagioclase, orthoclase (?), augite, iddingsite, hypersthene, flakes of limonite, and a little tridymitoMagmatic symbol, 1.5.3.3. Pulaskose.

B. From Silver Cliff, Colorado. Analysis by L. G.Eakins. Described by Cross. Contains plagioclase, 

orthoclase, augite, biotite, hornblende, quartz, magnetite, and apatite. Symbol, II.5.2.-1. Akerose.

C. Augite andesite, Bike Mountain, Yellowstone National Park. Analysis by Hillebrand. According 

to Arnold Hague and T. A. Jaggar it contains plagioclase, augite, apatite, magnetite, ai>d serpontinized 

olivine. Symbol, II.5.3.3. Shoshonose.

D. Augite-bronziteandesite, Unga Island, Alaska. Analysis by Hillebrand. Described by G. F. Becker. 

Contains plagioclase, augite, bronzite, a little glass, and some indeterminate material. Symbol, II.5.3.4. 

Andose.

E. Hypersthene andesite, Franklin Hill, Plumas County, California. ' Analysis by Hillebrand. Reported by H. W. Turner to contain plagioclase, rhombic pyroxene, augite, and magnesite. Symbol. 

II.5.4.3. Heasose. . ....

F. Augite andesite, near Electric Peak, Yellowstone National Park. Analysis by Hillebrand. 

Described by J. P. Iddings. Contains plagioclase,-malacolite, aclinolite, and magnetite. Symbol, III.5.3.3. 

Kentallenose. . -

Si02 . ........................

Al O

Fe203 ------------------- : ----

FeO..........................

MgO... ............ ..........

CaO.........................

Na20........................

K20.. .............. ..........

H2O-... .....................

H.P+.. ......................

TiO

Zr02 ... ......... ..............

P O

vao,.. ......................

MnO. ........................

NiO......... ................

BaO.........................

SrO.. ........................

LijO... ......................

FeS2 .......... ...............

A

62.64

17.82

3.91

.31

.47

3.22

4.47

4.99

.58

.65

.59

.08

.25

.04

.28

.07

100. 37

B

57.01

18.41

3.69

2.36

2.34

4.29

=> 4. 95

3.72

\ 2.29

.27

.42

.21

99.96

C

51. 17

16. 14

4.11

4.48

4.82

.7.72

2.99

3.54

.63

2.24

1.01

None.

.48

.04

.21

.01

.20

.10

Trace.

.05

99.94

D

5fi. 63

16.85

3.62

3.44

4.23

7.53

3.08

2. 24

.80

.51

.67

.16

.04

.23

Trace?

.09

Trnrp

.06

100. 18

E

56. 88

18.25

2.35

4. 45

4.07

7.53

3.29

1.42

.24

.50

.45

.30

'.18

.ii

.04

Trace.

100. 06

F

50.59

U 4Q

1.83

7.64

11.27

8 79

9 97

9 ^

91

1.76

.80

.48

.04

.17

.06

.10

no

Tra rt*

99.86

Norms.

Q.. ..........................

or............................

ah

OT"»

di.................. ..........

hy..........................

ol... ..........................

mt...........................

hm...........................

il....... .....................

oy\

A

10.2

30.0

37.7

13.6

1.8

.4

3.9

.6

B

2.2

22.2

41.9

16.7

1.7

5.9

5.3

.5

- i.o

C

\

20.6

25.2

20.3

12.4

8.5

. .6

5.8

1.8

' 1. 1

D

9.1

13.3

26. 2

25.3

9.1

8.4

5.3

1.2

E

9.1

8.3

27.8

30.9

5.3

13.2

3.5

.8

F

13.8

19.4

10 Q

oo 4.

8.7

14 1

2.6

i ^

1.0

Diorite is the plutonic equivalent of andesite. It is commonly 

defined as a granitoid rock consisting chiefly of plagioclase, with 

either biotite or hornblende, or both; but many diorites carry pyroxene also, and shade into the gabbros. In fact, as the femic minerals 

become more prominent in rocks the problems of classification 

become more complex, and the results are less satisfactory than with 

the similar mixtures of feldspar and quartz. A variety of diorite is
IGNEOUS ROCKS. 451

called " camptonite." Torialite and kersantite are other varieties. 

The following analyses represent the diorite group:

Analyses of dioritcs.

A. Diorite, Mount Ascutney, Vermont. Analysis by W. F'. Hillebrand. Described by R. A. Daly. 

Contains hornblende, augite, biotite, plagioclaso, titauiferous magnetite, titanite, zircon, and quartz. 

Magmatic symbol, II.5.2.3. Monzonose.

B. Diorite porphyry, La Plata Mountains, Colorado. Analysis by Hillebrand. Described by W. Cross. 

Contains hornblende, plagioclase, orthoclase, quartz, titanite, apatite, and magnetite, with secondary 

epidote, chlorite, and calcite. Symbol, II.5.2.4. Akerose.

C. Diorite, Crazy Mountains, Montana. Analysis by Hillebrand. According to J. E. Wolff it contains 

biotite, labradorite, augite, orthoclase, quartz, magnetite, apatite, and hornblende. Symbol, II.5.3.3. 

(Shoshonose.

D. Tonalite, South Leverett, Massachusetts. Analysis by L. G. Eakins. Described by B. K. Emerson. 

Contains feldspar, hornblende, and epidotic quartz veins. Symbol, II.5.3.4. Andosc.

E. Diorite, South Honcut Creek, Butte County, California. Analysis by Hillebrand. Reported by 

H. W. Turner to contain feldspar, hornblende, and a little chlorito. Symbol, H.5.3.5. Beerbachosc.

F. Camptonite, La Plata Mountains, Colorado. Analysis by Hillebrand. Reported by Cross to contain 

hornblende, augite, plagioclase, orthoclase, magnetite, apatite, and some secondary calcite. Symbol, 

III.5.3.3. Kentallenose.

G. Camptonite, Mount Ascutney, Vermont. Analysis by Hillebrand. Described by Daly. Contains 

plagioclase, hornblende, a little augite, olivine, magnetite, and apatite. Symbol, III.5.3.4. Cam-ptonose. 

x H. Diorite, Hump Mountain, Mitchell County, North Carolina. Analysis by Hillebrand. Reported 

by A. Keith to contain plagioclase, orthoclase, hornblende, quartz, biotite, magnetite, and garnet. Symbol, III.5.4.3. Auvergnose.

SiOa .. ...............

AI r»

Fe203 ................

FeO

MgO......... ........

CaO..................

NaoO...... ........'..

K26..................

HjO................

H20+. ...............

Ti02 ......... .....?..

Zr03 .. ...............

C0a ..................

P O &?! ::::::::::::::::

F...................

v o

Cr203 ---. - ----------

MnO. .................

(NiCo)O........ ......

BaO....... :.........

SfO..................

Li20......... ........

FeSa.... .............

A

57.97

17.28

2.23

3.75

2.20

4.33

4.31

4 1?

.18

.57

1 1.54

.05

.64

.04

.i5

Trace.

.07?

.32

99.75

B

60.44

16.65

2.31

3.09

2.18

4.22

5.18

2.71

.36

1.07

.60

.48

.29

.02

.13

.12

.11

Trace.

99.96

C

57.97

15.65

.73

2.80

4.96

10. 93

" 3.03

3.16

.22

.38

.60

.15

Trace.

Trace.

.09

.02

Trace.

100. 69

D

55.51

16.51

1.68

4.57

6.73

6.73

3.19

2.46

| 1.53

.91

.17

.ii

.02

100. 12

E

57.87

16.30

1.71

3.86

5.50

5.53

5.01

.75

.26

2.40

.53

.27

.08

.05

Trace.

Trace.

100. 12

F

47.25

15. 14

5.05

4.95

6.87

9.98

2.39

2.60

.4.0

2.12

1.22

1.87

.25

.05

.17

.02

.08

.05

Trace.

None.

100. 46

G

48.22

14. 27

2. 46

9.00

6.24

8.45

2.90

1.93

.28

1.66

2.79

.03

.15

.64

.10

.05

.20

.03

.04

.36

99.80

H

46.91

15.85

2.86

9.95

7.01

9.62

2.65

.69

94

1.62

2.03

.26

.03

.01

.22

.03

Trarp?

Trace?

Trace.

99.98

Norms.

Q....................

or....................

ab. .................

an

ne ..................

di..... ..............

hy.. ................

ol... ................

il... .................

Q-t-W ap...,k..<............

A

' 4.9

24.5

37.2

15.0

2.5

6.9

3.2

2.9

l 3

B

7.7

16.1

44.0

13.9

5.7

5.5

3.2

1.2

C

3.1

18.9

25.7

19.5

27.8

2.7

1.2

1.1

D

2.3

14.5

26.7

23.4

8.1

18.4

2.6

1.7

E

5.0

4.4

41.9.

20.3

5.9

16.5

2.3

1.1

F

15.0

17.8

22.8

.1.4

21.4

7.2

7.4

2.3

G

11.1

24.6

20.3

15.1

9.2

6.4

3.5

5.4

1.3

H

3.9

22.5

29.2

15.1

8.1

10.7

4.2

3.8
452 DATA OF GEOCHEMISTBY.

THE BASALTS.

The basalts form an ill-defined group of lavas which vary from the 

andesites in containing a larger proportion of the femic minerals. 

Plagioclase, pyroxene, often olivine, and magnetite are the principal 

minerals of basalt, but many variations of it are known. Some 

basalts are free from olivine, other examples contain such minerals as 

leucite, nephelite, melilite, etc. Hornblende basalts are known, but 

they are rare. In a few basalts quartz has been identified, but its 

presence is anomalous and not well explained.1 The following 

analyses relate to basalt, as the unqualified term is commonly used.

Analyses of basalts.

A. Basalt, early flow, Table Mountain, Colorado. Analysis by L. G. Eakins. Described by W. Cross. 

Contains augite, olivine, plagioclase, probably orthoclase, magnetite, apatite, and a little biotito. Magmatic symbol, II.5.3.3. Shoshonose.

B. Basalt, Saddle Mountain, Pikes Peak, Colorado. Analysis by W. F. Hillebrand. Described by 

Cross. Contains augite, olivine, plagioclase, orthoclase, magnetite, biotite, and apatite. Symbol, II.5.3.4. 

Andose.

C. Quartz basalt, Cinder Cone, near Lassen Peak, California. Analysis by Hillebrand. Described by 

J. S. Diller. Contains plagioclase, pyroxene (mostly hypersthene), olivine, quartz, magnetite, augite 

sparingly, and much unindividualized base. Symbol, II.5.3.4. Andose.

D. Basalt, San Joaquin River, Madera County, California. Analysis by Hillebrand. Reported by 

H. W. Turner to contain pyroxene, partly augite, plagioclase, olivine, and iron ore. Symbol, II.5.3.4, 

Andose.

E. Basalt, McCloud River, near Mount Shasta, California. Analysis by H. N. Stokes. Not described. 

Symbol, II.5.4.3. Hessose. ......

F. Basalt, San Rafael flow, Colfax County, New Mexico. Analysis by Hillebrand. According to Cross 

it contains plagioclase, augite, olivine, much iddingsite, magnetite, and apatite. Symbol, III.5.3.4. Co,mptonose.

G. Basalt, Pine Hill, South Britain, Connecticut. Analysis by Hillebrand. Described by W. H. Hobbs. 

Contains plagioclase, augite, olivine, and magnetite. Symbol, III.5.4.3. Auvergnose.

Si02 ..................

Al O

Fe203 .................

FeO

MgO.. ..............

CaO.. ................

Na-jO........... ......

K20. ................

H20-. ...............

HaO+... ............

Ti02 .......... ......

P O

1$?:;::::::::::::::

Cl. ..................

MnO................

NiO..................

BaO.. ................

SrO............ .......

Li20..................

FpS

A

49.69

18.06

2.64

6.19

5.73

8.24

2.99

3.90

\ 91 / <J1

.85

.81

.13

.13

100. 27

B

4.8. 76

15.89

6.04

4.56

5.98

8.15

3.43

2.93

.40

1.48

1.65

.60

.13

.17

.06

100. 23

C

57.25

16.45

1.67

4.72

6.74

7.65

3.00

1.57

| .40

.60

.20

.10

.03

Trace.

None.

100. 38

D

51.89

15.28

3.10

3.60

8.68

7.38

3.27

2.57

1.17

1.37

.91

.61

.12

.02

.15

.09

Trace.

100. 21

E

47.94

18.90

2.21

8.59

8.21

9.86

2.81

.29

.39

.74

.57

.15

Trace.

Trace.

100. 66

. F

48.35

15.47

4.80

7.58

8.15

8.81

3.09

.95

.28

.73

1.33

.33

.07

91

.02

.06

.03

Trace.

100. 26

G

52.40

TO CC

2.73

9.79

5.53

10.01

2.32

.40

.62

1.05

1.08

.12

9fi

Trar'p

Trace.

None

.13

99.99

« See J. S. Diller, Bull. U. S. Geol. Survey No. 79,1891.
IGNEOUS ROCKS.

"453

Analyses of basalts Continued. 

Norms.

Q.... ..........;......

or...................

ab...................

an ..................

ne..... ..............

di....................

hy....... ............

ol............ ........

....................

f\-ir\ ap...................

A

22.8

19.4

24.5

3.1

9.4

12.8

3.7

1.7

1.9

B

17.2

9fi 7

19.2

1.1

14.1

6.5

8.6

3.1

1.3

C

6.9

9.5

25.2

26.7

9.0

18.9

2.3

1.1

D

15.0

27.8

22.2

9.0

7.9

7 2

4.6

1.7

1.2

E

1.7

oq a

38.1

8.9

5.9

17.0

3.2

1.1

F

5.6

26.2

25.6

14.7

6.7

10.5

7.0

2.5

G

6.7

9 9

10 4.

25.6

19.7

18:1

3.9

2.2

The following table contains analyses of a number of exceptional 

rocks, which are classed with the basalts, but vary from them in 

having the feldspar more or less replaced by leucite, nephelite, 

or melilite. The unique venanzite is placed here, as being more 

nearly akin to this group of rocks than to any other. The analcite 

basalts given in a previous table properly belong here also, and so 

perhaps do some of the rocks described in connection with the tables 

on pages 438-445.
454 DATA OF GEOCHEMISTRY.

Analyses of basaltic rocks:-

A. Kulaite, Kula, Lydia, Asia Minor. Described and analyzed by H. S. Washington, Jour. Geology, 

vol. 8, 1900, p. 613. Contains, in percentages, anorthite, 17.9; albitc, 8.4; orthoclase, 23.4; nephelitc, 20.4; 

diopside, 12.8; olivine, 10.7; magnetite, 3.8; apatite, 1.8. The diopside is derived from hornblende. 

Magmatic symbol, II.6.2.4. Essexose.

B. Leucite kulaite, Kula. Described and analyzed by Washington, ioc. cit. Contains, in percentages, 

anorthite, 17.9; albite, 23.6; leucite, 17.4; nephelite, 12.8; diopside, 13.8; olivine, 9.5; magnetite, 3.7. 

Symbol, II.6.2.4. Essexose.

G. Basalt, Pinto Mountain, Uvalde County, Texas. Analysis by W. F. Hillebrand. Described by 

W. Cross. Contains olivine, augite, plagioclase, magnetite, apatite, and a very little alkali feldspar. 

Symbol, III.6.3.4. Limburgose.

D. Leucite basalt, Highwood Mountains, Montana. Analysis by H. W. Foote. Described by W. H. 

Weed and L. V. Pirsson. Contains augite, olivine, biotite, some leucite, analcite, iron ore, and apatite. 

Symbol, III.7.2.3. No subrang name given.

E. Venanzite or euctolite, San Venanzo, Umbria, Italy. Described by H. Rosenbusch, Sitzungsb. Akad. 

Berlin, 1899, pt. 1, p. 111. Contains olivine, melilite, leucite, biotite, magnetite, some zeolites, and a trace 

ofnophelite. Symbol, IV. 1M.2. Venanzose.

F. Nephelite basalt, Tom Munn's Hill, Uvalde County, Texas. Analysis by Hillebrand. Described by 

Cross. Contains olivine, augite, nephelite, magnetite, and apatite. Symbol, IV.2*.1.2. Uvaldose.

G. Nephelite basalt, Black Mountain, Uvalde County, Texas. Analysis by Hillebrand. Described by 

Cross. Contains olivine, augite, nephelite, magnetite, and apatite. Symbol, IV.22 .1.2. Uvaldose.

H. Nephelite-melilite basalt, near Uvalde, Texas. Analysis by Hillebrand. Described by Cross. 

Contains nephelite, melilite, olivine, augite, apatite, and magnetite. Symbol, IV.23.1.2. Casselose.

Si02 .. ...............

Al O

Fe203 .... ............

FeO..................

MgO......... ........

CaO..... ............

Na20. ...............

K20........ ..........

H20-. ....... ......

H20+. .............

TiO,.. ....... ........

P O

I? !::::::::::::::::

S03 ... ..............

Cl.. ................

F...................

V203 .--. ...... ......

Cr203 -- -------------

MnO........... ......

NiO..... ............

BaO....... ..........

SrO............ ......

Li2O......... ........

A

48.35

19 Q4

2.48

5.25

5.15

7. '98

5.47

3. 99

.16

.22

12

.84

Trace.

99.95

B

49.90

19.89

2.55

4.78

5.05

7.21

5.60

3.74

.13

.19

.93

Trace.

Trarp

99.97

C

45.11

12.44

2.G7

9.36

11. 56

10.61

3.05

1.01

.16

.78

2.34

.51

.01

.11

Undet.

.04

.22

.04

Trace.

Trace.

None

100. 02

D

46.04

12.23

3.86

4.60

10.38

8.97

2.42

5.77

} 2.87

.64

1.14

Trarp

.11

Trace.

.48

.25

99.76

E

41. 43

9.80

3.28

5.15

13. 40

16. 62

1.64

7.40

}rn

.29

None.

100. 12

F

40. 32

Q 46

4.75

7.48

18. 12

10. 55

2.62

1.10

.57

1.25

2.66

.68

.01

.05

.04

.25

.06

.06

no

Trace

,

100.09

G

39.92

8.60

4.40

8.00

20.17

10.68

1.91

1.03

40

1.45

2.70

.51

Trarp

Trace

.07

.04

.14

04.

.06

.06

.04

Trace '

100. 45

H

37.96

10.14

3.69

7 F»Q

M 6Q

16. 28

2.18

.69

OQ

1.82

2.93

1.13

fU

no

Tripp

.07

.05

Oft

99

.04

.06

.05

Trn PA

100. 13
IGNEOUS EOCKS.

Analyses of basaltic rocks Continued. 

Norms.

455

ab....................

ne.... .................

kn Kp.... ...............

Ic...................

ac....................

di..... ..............

ol. ..................

mt........... ........

il.. ..................

ai>...

A

23. 4

8.9

18.1

20.1

13.4

10.1

3.8

1.8

B

22.4

13.6

18.1

18. 2

14.2

7.6

3.7

1.7

C

6.1

13.1

17.2

6.8

26.4

19.8

3.9

4.3

1.1

D

22.2

5.3

11.1

9.6

. 26.3

12.3

5.6

1.2

2.6

 E

4.8

25.0

4.2

32.3

29.8

2.8

.6

F

3.3

1.1. 1

11.9

2.6

29.3

26.2

7.0

5.1

1.6

Cr

12.0

8.5

4.9

24.6

32.1

2.4

6.3

5.1

1.2

H

18.6

9.9

3.1

13.5

26.1

13.8

5.3

4.4

2.6

The appearance of normative kaliophilite in analysis E is very 

striking. The absence of normative leucite from the '' le ucite kulaite'' 

is also noticeable.

DIABASE.

Intermediate in texture between basalt and the granitoid gabbros 

are the diabases, which, like basalt, are principally composed of plagioclase, augite, magnetite, and sometimes olivine. Their range of 

composition is fairly well shown in the next table.
456 DATA CXF GEOCHEMISTRY.

Analyses of diabase.

A. Turnpike Creek, Kittitas County, Washington. Analysis by W. F. Hillebraud. Reported by G. 0. 

Smith to contain plagioclase, augite, olivine, magnetite, and apatite. Magmatic symbol, II.4.3.4. 

Tonalose. . __ . .

B. Grass Valley, Nevada County, California. Analysis by H. N. Stokes. Described by W. Lindgren. 

Contains feldspar, pyroxene, hornblende, ilmenite, pyrrhotite, pyrite, and chloritc, with probably a little 

quartz. Symbol, II.4.4.3. Bandose.

C. Shoshone Canyon, Ycllowstone National Park. Analysis by Hillebrand. Contains, according to 

Arnold Hague and T. A. Jaggar, plagioclase, augite, and chlorite. Symbol, II.5.3.4. Andosc.

D. Aroostook Falls, Maine. Analysis by Hillebrand. Description by H. E. Gregory. Contains plagioclase, pyroxene, pyrite, apatite, chlorite, and alittle calcite. Symbol, II.5.3.5. -Beerbachose. 

E. Diabase porphyry, near Milton,-Sierra County, California. Analysis by Hillebrand. Described by 

H.W.Turner. Contains plagioglase, augite, and hornblende. Symbol,. III.5.3.4. Camptonose.

F. Mount Ascutncy, Vermont. Analysis by Hillebrand. Described by R. A. Daly. Contains plagioclase, augite, and magnetite. Symbol, III.5.4.3. Auvergnose.

Si02 ..... ....................

A1203 -----,-------- ----------

Fe203 ------------------------

FeO.... ...................:..

MgO. ........................

CaO........ ......... ..........

NaoO..........................

KoO..........................

HoO-.. ......................

H~O_i_

TiO,... ......................

co2 :. ........................

P O

fc:::::::::::::::::::::: VA------ --------------------

MnO..... ....................

NiO.... .......................

BaO.........................

SrO.. ........................

Li.,0.........................

FeS2 .........................

A

57.21

12.99

3.28

. 10. 18

1.59

5.97

3.07

1.61

.68

1.03

1.72

.44

None.

.24

Trace.

.06

Trace.

Trace.

.13

100. 20

B

53.19

17.12

4.35

5.16

3.98

9.39

2.79

.28

.17

1.21

1.34

. .13

Trace.

Trace.

.94

100. 05

C

52. 18

18.19

3.31

4.36

4.69

6.51

4.58

1.88

.75

2.00

.99

None.

.29

Trace.

.14

Trace.

.11

.06

Trace.

100. 04

D

49. 64

15.07

1.66

8.82

5.43

7.23

4.19

.89

.45

2.81

2.32

.32

.29

.04

.25

Trace.

.02

.05

.79

100. 27

E

51.27

12 14

2.51

6.71

10.88

10.32

2.00

1.63

.17

1.16

.60

.21

.21

.04

.07

Trace?

Trarr>

99.92

F

49.63

14.40

2.85

8.06

7 9^

Q 98

2.47

.70

97

] 47

1.68

1.36

.25

.07

.17

.04-

Trace ?

99

100. 17

Norms.

Q...... ....... ...............

an............................

di..... ...... ...... ...'.........

hy.. ..........................

ol...... .......................

mt..... ......................

il...... ......................

pr............................

ap............................

A

15.4

9.5

26.2

16.7

8.9

12.5

4.9

3.2

1.0

B

10.4

1.7

23.6

33.4

10.6

9.5

6.3

2.5

.9

C

ii. i

38.8

23.4

7.2

3.8

5.8

4.9

1.8

D

5.0

35.6

19.7

13.9

6.0

9.0

2.3

4.3

E 

9.5

16.8

19.5

25.4

16.5

5.7

3.5

1.2

F

1 ^

4.4

21.0

25.9

16.6

19.8

4.2

3.2

THE GABBROS.

The gabbros, which are the granitoid equivalents of the basalts 

and diabases, consist mainly of plagioclase and pyroxene, with various admixtures of other minerals. At one end of the series we have 

anorthosite, or labradorite rock, which is almost entirely composed 

of feldspar; at the other end the plagioclase diminishes in amount, 

and the rocks approach the pyroxenites. Normal gabbro contains
IGNEOUS ROCKS. 457

inonoclinic pyroxene; in norite, rhombic pyroxene, usually hypersthene, appears. The gabbro family is a large one, with many varieties of rock, and only a few examples of it are covered by the subjoined

table.

Analyses of gabbros.

A. Anorthosite, Monhegan Island, Maine. Analyzed and described by E. C. E. Lord, Am. Geologist^, 

vol. 26,1900, p. 340. Nearly pure plagioclase. Magmatic symbol, 1.5.5. Canadase.

B. Gabbro, near Emigrant Gap, Placer County, California. Analysis by W. F. ITillebrand. Described 

by W. Lindgren. Contains biotite, hypersthene, diallage, plagioclase, and orthoclase. Symbol (1.5.3.4. 

A ndose.

C. Gabbro, Emigrant Gap, California. Analysis by Hillebrand. Described by Lindgren. Contains 

hypersthene, diallage, plagioclase, and orthoclase. Symbol, III.4.3.-1. Vaalose.

D. Norite, Elizabethtown, Essex County, New York. Analysis by Hillebrand. Described by J. F. 

Kemp. Contains labrc,dorite, hyperstheno, garnets, augite, hornblende, biotite, magnetite, and apatite. 

Symbol, I1I.5.3.4. Camptonose.

E. Bronzite norite, Crystal Falls, Michigan. Analysis by G. Steiger. Described by 3. M. Clements 

and H. L. Smyth. Contains bronzite, hornblende, and labradorite. Symbol, 10.5.4.3. Auvergnosc.

F. Olivine gabbro, Birch Lake, Minnesota. Analysis by II. N. Stokes. Contains a large proportion 

of diallage and olivine. Symbol, III.5.4.3. Auvcrgnose.

G. Hypersthene gabbro, Wetheredville, Maryland. Analysis by Hillebrand. Described by G. H. 

Williams. Contains hypersthene, diallage, plagioclase, magnetite, and apatite. Symbol, III.5.5. Kedabckase. ,

H. Hypersthone gabbro, Gunflint Lake, Minnesota. Analysis by Stokes. Described by W. S. Bayley. 

Contains hypersthene, biotite, diallage, magnetite; and plagioclase. Symbol, IV.1.1.2. Cookost.

Si02 ................

A1 303 ----------- 

Fe203 -- ..............

FeO................

MgO.. ....... ........

CaO.. ...............

Na,0................

K,0. ............... H;O-... .............

E,0+. ...............

TiO.,... ...... ........

co2 :.................

p PA....- o ...........

v2o3 - ...............

Cr203 --- ...... ...-,.

MnO........... ......

NiO. ................

BaO....... ..........

SrO..................

Li20......... ........

A

45.78

30. 39 

1.33

1. 22

2.14

16. 66

1. 6G

.10

1 51 r - 01

99. 79

B

55. 40

15. 32 

2.70

5.49

5.75

9.90

2.89

1.52

.03

.38

.60

.22

.11

.07

TXTnnf1

Trace.

100. 38.

C

55.87

13.52 

2.70

5.89

6.51

8.87

2.42

1.72

.09

1.56

.56

.25

.10

.02

Trace.

100. 08

D

47.16

14.45 

1.61

13.81

5.24

8. 13

3.09

1.20

.12

.48

3.37

.35

.57

.14

(?)

.24

.02

99.98

E

48.23

18. 26 

1.26

6.10

10. 84

9.39

1.34

.73

.26

2.00

1.00

.43

.07

99.91

F

45.66

16. 44 

.66

13. 90

11.57

7.23

2.13

.41

.07

.83

.92

.05

Trace.

Trace.

.16

100. 03

G

44.76

18. 82 

2.19

4.73

11.32

14. 58

.89

.11

.17

2.36

.13

.08

.15

Trace.

100. 29

H

4fi Ofi

14. 13

.76

. 14. 95

15. 97

2.32

.35

1.68

.07

1.26

.62

.03

rPra*"*p

.93

.06

100. 09

Q....................

ab ..................

TIP

C............. .......

di..... ..............

hy........ ..........

ol ...................

mt........... ........

il. ....................

0 f\

A

0.6

12.1

75.1

1.1

6.1

2.5

1.9

B

5.1

8.9

24.6

24.2

20.5

11.4

3.9

1.1

C

8.0

10.0

20.4

20.9

19.0

14.6

3.9

1.1

D

7.2

26.2

22.0

12.5

8.1

12.8

2.3

6.4

1.3

E

3.9

11.0

42.0

3.9

29.9

2.9

1.9

1.8

F

2.2

17.8

34.2

1.4

10.1

30.3

.9

2.6

G

0.6

7.3

47.0

20.1

3.1

16.0

3.2

H

10.0

3.1

11.4

7 t\

57.5

6.0

1.2

1.1
458 DATA OF GEOCHEMISTRY.

These figures, with a range from persalane to dofemane, from 

1.5.5 to IV.1.1.2, are enough to show the vagueness of the terms 

gabbro and norite. Although it is difficult to see why B and C 

should be separated, being placed in different classes, orders, and 

rangs, the quantitative system brings out the general diversity of 

character better than the ordinary mineralogical classification. It 

separates things which, with the exception above noted, are essentially distinct.

FEMIC BOCKS.

From the feldspathic gabbros rocks pass by insensible gradations 

into varieties which are wholly femic, or nearly so, the pyroxenites, 

hornblendites, and peridotites. These rocks may contain pyroxene 

alone, hornblende alone, or olivine alone, or may be mixtures of such 

minerals. Small quantities of plagioclase may remain as minor 

impurities; but they count for little in classification. Dunite is 

nearly pure olivine; saxonite contains enstatite and olivine; picrite 

is a mixture of augite and olivine. In cortlandtite we have bornblende and olivine; in wehrlite, diallage and olivine; in Iherzolite, 

diopside, a rhombic pyroxene, and olivine. Websterite contains 

bronzite and diopside, and so forms the pyroxeiiite end of the series. 

The nomenclature is varied, and the terms are not rigorously used. 

Homblendite is a femic rock in which hornblende is the prevailing 

mineral. The following table deals with the rocks in which pyroxenes predominate:

vV
IGNEOUS ROCKS. 459

Analyses of pyroxenites.

A. Cortlandtite, Belchertown, Massachusetts. Analysis by L. G. Eakins. Described by B. K. Emerson. Contains hornblende, pyroxene, biotite, olivine, and magnetite. Magmatic symbol, IV.l'.l.l.. 

Belc.herose.

B. Wehrlite, near Red Bluff, Montana. Analysis by Eakins. Described by G. P. Merrill. Contains 

olivine, diallage, brown mica, rarely plagioclase, and secondary iron oxides. Symbol, IV.l'.l .2. Wehrlose.

C. Hornblende picrite, North Meadow Creek, Montana. Analysis by Eakins. Described by Merrill. 

Contains hornblende, olivine, pleonaste, iron oxides, and occasionally hypersthene. Symbol, IV.13.1.2. 

Wehrlose.

I). Pyroxenite, Baltimore County, Maryland. Analysis by J. E. Whitfleld. Described by G. 11. 

Williams. Contains hypersthene and diallage. Symbol, V.l'.l.l. Maricose.

E. Websterite, Webster, North Carolina. Analysis by E. A. Schueider. Described by Williams. 

Consists of diopside and bronzito. Symbol, V.l'.2.1. Wcbsterose.

F. Wobsterite, Oakland, Maryland. Analysts by W. F. Hillebrand. Described by A. G. Leonard. 

Contains hypersthene and diallago. Symbol, V.l',1.2. Cecilose,

G. Lherzolite, Baltimore County, Maryland. Analysis by T. M. Chatard. Described by Williams. 

Contains olivine, bronzite, and diallage, the olivine partly serpentinized. Symbol, V.l'.l.l. BaUimoriasc.

It. Pyroxenite, Baltimore County, Maryland. Analysis by Whitfield. Described by Williams. Contains hypersthene and diallage. Symbol, V.R1.2. Baltimorose.

SiOa .. ...............

A1203 .. ..............

Fe2 03 ----------------

FeO

MarO......... ........

CaO..... ............

NaaO........ ........

K.6.................. H;O.................

H20+.. ..............

Ti02 .. ....... ........

P

A

coa ..................

s. .....................

S08 ................. ci...... ..............

V203 ----------------

Cr208 - ---

MnO.... ....... ......

(Ni,Co)0............

FeS,. ................

A

48. 63

5.32

2.91

3.90

21.79

13.04

.34

23

A, ol

.47

.21

Trace.

-.36

.12

100. 13

B

48.95

5.69

1.20

12.11

23.49

5.33

1.58

.79

1 18 \ - 18

.81

.12

.05

.08

.16

100. 54

C

46.13

4.69

.73

16.87

25,17

4.41

.08

Trace.

1. OO

.73

.07

.24

.04

Trace.

.09

100. 63

D

51.94

2.53

2.88

9.38

25.97

3.60

None

None.

JL. OO

None.

None.

.19

.16

.60

Trace.

100. 07

E

55. 14

.66

3.48

4.73

26.66

8.39

.30

.38

Trace.

.23

.25

.03

.11

100. 36

F

53.21

1.94

1.44

7.92

20.78

13.12

.11

.07

.14

' .87

.26

Trace.

.10

.03

.20

.22

.03

.03

100. 47

G

43. 87

1.64

8.94

2.60

27.32

6.29

1 .50

1.08

7.64

.12

Trace.

.44

.19

Trflr*^

100. 63

H

50.80

3.40

1.39

8.11

22.77

12.31

JTrace.

1 5?

> . 0<!

None.

Trace.

Tra PA

94

.32

.17

100.03

Norms.

Q.... ....... .........

or....................

ab....................

di..... ..............

hy..................

ol...................

il.... ....... .........

A

1.1

2.6

12.5

41.7

21.9

11.7

5.1

B

5.0

13.6

5.6

16.5

18.5

37.6

1.6

1.5

C

.5

12.5

7.6

44.8

30.4

.9

1.2

D

0.6

6.7

8.9

76.4

2.8

E

1.7

2.6

32.7

57.1

5.1

F

0.6

1.0

3.2

48.9

41.4

2.1

.5

G

4.2

9 9

22.6

34.3

16.3

8.4

3.0

H

Q 9

41.4

33.8

19 9

9 1
460 DATA OF GEOCHEMISTRY.

The general presence of chromium and nickel iii these rocks is 

noteworthy. The wehrlite (analysis B) is almost on the line between 

pyroxenites and peridotites. The formation of actual diallage from 

the normative diopside in it would give the pyroxenes a slight predominance over the olivine. The following analyses represent 

peridotites:

Analyses of peridotites.

A. Cortlandtite, Ilchcster, Maryland. Analysis by W. F. Hillebrand. Described by G. H. Williams. 

Contains olivine, pyroxene, and hornblende partly altered to talc. Magmatic symbol, IV.l'.l.l. Corthndtose. B. Peridotite, near Silver Cliff, Colorado. Analysis by L. G. Eakins. Described by W. Cross.

 B. Peridotite, near Silver Cliff, Colorado. Analysis by L. G. Eakins. Described by W. Cross. Contains hornblende, biotite, hypersthene, olivine, a little plagioclase, apatite, pyrrhotite, and sillimanite. 

Symbol, IV.1U.2. Cttsterose.

 C. Peridotite, near Opin Lake, Michigan. Analysis by Hillebrand. Described by C. B. Van Hise 

and W. S. Bayley. Contains diallage, olivine, magnetite, and plagioclase. Symbol, IV.23.1.2.

D. Mica peridotite, Crittenden County, Kentucky. Analysis by Hillebrand. Described by J. S. Diller. 

Contains biotite, serpentine, and perofskite, with less apatite, museovite, magnetite, calcite, chlorite, and 

other secondary products. Symbol, IV.2U.2. Subrang of Casseliase.

E. Saxonite, Douglas County, Oregon. Analysis by F. W. Clarke. Described by J. S. Diller and F. W. 

Clarke. Contains olivine and enstatite, with a little magnetite and chromite. Symbol, V.K1.1. 

Gordunose.

F. Dunite, Corundum Hill, North Carolina. Analysis and description oy T. M. Chatard. Contains 

Olivine, with a little chromite. Symbol, V.15 .1.1. Dunose. ' 

G. Peridotite, Tulameen River, British Columbia. Analysis by Hillebrand. Described by J. F. Kemp; 

Contains olivine and serpentine, with magnetite, magnesite, and calcite. Symbol, V.F'.l.l. Dunose.

Si02 ........ ..........

Al O

Fe203 -----------------

FeO... ..............

MgO..................

CaO..................

Na20........... ......

K o

H20-... ............

E20+... ............

Ti02 ..................

G02 ............ .......

P.,05 ---------- ------

s:..5.................

Cl....... ............

PT n

MnO..................

NiO............ ......

BaO...... ............

Chromite ............

A

39. 20

4.60

3.45

6.15

31.65

3.23

.42

.14

.50

9.38

.52

Trace.

.41

.20

.30

100. 15

B

46.03

9.27

2.72

9.94

25.04

3.53

1.48

.87

| .64

.17

.40

100. 09

C

39.37

4.47

4.96

9.13

26.53

J.70

.50

.26

.87

7.08

.66

1.23

.17

.68

.12

.21

Trace.

*

99. 94

D

33.84

5.88

7.04

5.16

22. 96

9.46

.33

2.04

| 7.50

3.78

.43

.89

.05

.18

.16

.10

.06

99. 86

E

41.43

.04

2.52-

6.25

43. 74

.55

 4.41

.76

None.

.10

99.80

F

 40.11

.88

1.20

6.09

58.58

2.74

.18

.56

100. 34

' G 

38.40

.29

3.42

6.69

45. 23

.35

1 .08

.24

4.11

1.10

Trace.

.06

.07

.24

.10

None.

100. 38
IGNEOUS EOCKS. 461

Analyses of pcridotitcs Continued.

Norms.

or. ..................

ah

Ic

e.. ............. ......

<li............ ........

hy....... ............

ol ....................

am

il.... .................

cm ..................

or\ ap... ................

A

0.6

.3.1

10.6

4.4

16.8

47.9

5.1

< 0

B

5.0

I 9 6

16.1

16.7

44.3

3.9

.4

c

1.7

4.2

9.2

7.4

21.1

37.5

7.2

' 1.2

1.0

D

8.6

1.4

9.4

7.7

37.6

8.5

6.0

2.9

7.1

1.9

E

2.3

19.3

69.2

3.5

1.2

F

0.9

4 7

89.7

1.6

.8

G :

6.8

.4

6.2

81.9

.4.9

In the peridotites a certain amount of serpentinization is almost 

always observed. This is shown in the analyses by the unusually 

large percentages of water. The latter is neglected in calculating the 

norms, and so normative hypersthene appears, which an absolutely 

unaltered rock would not show. That is, serpentine, instead of representing the parent olivine, is equivalent to hypersthene plus olivine, 

and the norms become misleading. A rock consisting originally of 

pure olivine might find its place in any one of several different rangs 

or subrangs, according to the amount of alteration which it has 

undergone. Two samples from the same rock mass might vary in 

this manner.. Theoretically, no doubt, the quantitative classification 

applies only to fresh material; practically it is applied to altered 

peridotites, like those cited above, which all appear in Washington's 

tables. A very remarkable peridotite from East Union, Maine, 

described by E. S. Bastin,1 contains 22.5 per cent of sulphides, 

mainly pyrrhotite. Magmatic name, lermondose. :

BASIC BOCKS.

A few igneous rocks exist which seem to form an exceptional group 

by themselves. They consist largely, or even mainly, of free basic 

oxides, such as corund um or magnetite; and many transitional mixtures lie between them and the ordinary silicate rocks. With these 

oxides it is convenient to group certain titaniferous rocks, which 

otherwise might form a class by themselves. The following analyses 

represent a few rocks of this truly basic character, with examples of 

the transitional forms.

» Jour. Geology, vol. 16,1908, p. 124.
462 DATA OF GEOCHEMISTRY.

Analyses of basic and titani/erous rocks.

A. Corundum pegmatite, Ural Mountains, Siberia. Described and analyzed by J. Morozewicz, Min; 

pet. Mitt., vol. 18, 1898, p. 219. Contains corundum and orthoclase, with accessory rutile, apatite, and 

zircon. Magmatic symbol, I1 .5.1.3. Uralose. 

B. Kyschtymite, Borsowka, Ural Mountains. Described and analyzed by Morozewicz, op. cit., p. 212, 

Contains corundum, with little spinel, anorthite, biotite, and zircon. Symbol, I'.S.S. Kyschtymase.

C. llmenite norite, Soggendal, Norway. Described and analyzed by C. F. Kolderup, Bergens Museums 

Aarbog, 1896,p. 165. Contains, in approximate percentages, ilmenite, 37.5; hypersthene, 40.1; auorthite, 

11; albite, 8.7; orthoclase, 0.9. Symbol, IV.3M.3. Bergenose.

D. Titaniferousiron ore, Lincoln Pond, Essex County, New York. Analysis by W. F. Hillebrand; 

Described by J. F. Kemp. Symbol,IV. 4S .1.4. Adirondacltiase.

E. Titaniferous iron ore, Elizabethtown, New York. Analysis by Hillebrand. Described by Kemp. 

Symbol, rv.4'.1.4. Champlainiase.

F. Magnetite spinellite, Routivaara, Finland. Analyzed and described by W. Petersson, Ceol. Foren. 

Forhandl., vol. 15, p. 49,1S93. Symbol, V.5'.1.4. No magmatic name assigned.

Si02 . ........................

A1 O

Fe208 .............. ..........

PpO

MgQ... ......................

Cab. ........................

Na20. .......................

K20.......... ........ ........

H20.......... .......... ...... Tin

CO..............................

p o

s?^:::::.::::::::::::::::::::

Cl..... .......................

V203 ....... ...................

Cr203 -- ..---. -----------------

MnO. ........................

Organic matter. ...............

Corundum. . ..................

A

40.06

13.65

.35

.15

.20

3.71

5.20

.46

........

35.40

99.28

B

16.80

13. 89

.76

.61

7.26

.38

.13

.76

o 59. 51

100. 00

C

31.59

8.54

24.52

2.36

 10.70

2.25

1.03

.15

18.49

.02

99.65

D

11. 73

6.46'

30.68

27.92

3.35

3.95

.50

.26

.64

12.31

.32

.82

.04

.12

.04

.05

99.19

E

13. 35

8.75

20.35

28.82

6.63

2.15

1.68

16.45

.17

.02

.09

Trace.

.61

.55

Trace.

99.62

F

4.08

6.40

33.43

34.58

3.89

.65

.29

.15

1.32

14.25

.02

.20

.45

99.71

Norms.

ab............................

an............................

lc.. .........................

C..... ..'... ..................

hv............. ...... .........

01. ..........................

int...........................

il......... ...... .............

ap.............. ......... .....

MgO........ .................

FeO... .........................

A

30.6

27.2

1.4

2.3

36.8

.7

B

0.6

35.9

1.7

59.5

2.0

C

1.1

8.4

11.1

2.7

34.6.

3.8

3.5

35.1

D

14.0

2,3

1.3

10.6

44 *>

23 7

1.9

E

10.8

4.8

5.7

14.8

29.5

31.0

F

1.1

2.6

3.1

4.6

48.5

26.8

3.9

6.9

a Including a little spinel.
IGNEOUS ROCKS. 463

Analyses of basic and titaniferous rocks Continued.

G. Magnetite basalt, arapahite, North Park, Colorado. Described by H. S. Washington and E. S. Larsen, Jour. Washington Acad. Sci., vol. 3, 1913, p. 449. Contains magnetite, bytownite, pyroxene, and a 

little apatite. Symbol, IV.4(5).1.1. Arapahose.

H. Cumberlandite, Cumberland, Rhode Island. Described by B. L. Johnson and C. H. Warren, Am. 

Jour. Sci., 4th ser., vol. 25,1906, p. 1. Contains magnetite, ilmenite, plagioclase, olivinc, and minor accessories. Symbol, V..3.1.2. Ehodose.

I. Gabbro-nclsonite, Nelson County, Virginia. Contains ilmenite, apatite, hypersthene, plagioclase, 

some orthoclase, with grains of quartz and pyritc. Symbol, IV.3.1.2.3. Rosdandose.

J. Ilmenite-nelsonite, Nelson County, Virginia. Contains ilmenite, apatite, minor hornblende, biotite, 

leucoxene, etc. Symbol, V.5.5.5.3. Nelsonose.

K. Rutile-nelsonite, Nelson County, Virginia. Contains rutile and apatite, with accessory feldspar, 

ilmenite, and quartz. Symbol, V.5.5.4.5. Virginose. Analyses I, J, K, by W. M. Thornton, jr. Rocks 

described, with others of similar character, by T. L. Watson in Geol. Survey Virginia, Bull. Ill, A, 1913.

L. Perofskite-apatite-maguetite rock, Uncompahgre quadrangle, Colorado. Collected by E. S. Larsen, 

analyzed by G. Steiger. Contains about equal amounts of perofskite, magnetite, and biotite, with less 

apatite, and perhaps a little ilmenite. Symbol, V.2.4.4.2.

Si02 .........................

A180S ...... ..................

Fe203 --- .....................

FeO

MgO.........................

CaO. ........................

Na20.. ......................

K20. .........................

H20-... ..................... ^0+. .......................

ViO^... ......................

Zr02 ..... ....................

co,:.........................

P O

s^5::::.:::::::::::::::::::::

F................. ............

Cl............................

V O

f Lr r\ aO8 ......... ................

MnO..... ....................

NiO.........................

(Ni, Co)...... ................

BaO. ................... ........

SrO. .........................

Zn...........................

Cu..... ......................

Pb..... .......................

LessO.............. ..........

G

19.74

9.72

39.70

15.60

3.70

6.64

.46

.66

.32

.04

.58

None.

1.67

.44

None.

.38

None.

99. 65

H

22.35

5.26

14.05

28.84

16.10

1.17

.44

.10

.42

10.11

.02

.02

.38

.18

Traop

.43

.08

.71

.08

rP-par-C*

100. 74

1Q

100. 55

I

33.83

5.19

11.38

15. 08

8.57

8.22

1.28

.50

.45

.75

10.00

Trace.

4.84

.25

.55

.04

.26

101. 19 

.30

100. 89

J

0.70

11.12

27.93

.72

8.34

.15

.58

42.84

Tracp

6.89

21

.01

.18

99.67 

.08

99.59

K

0.67

2.87

5.04

.15

12.16

no

.11

 69. 67

9 41

QA

.70

Tr$ir»p

101. 21

OQ

100. 82

L

8 41

.74

19.16

no fto

5.06

1Q Q8

oe

CQ

OK

rt ^

94 74

.01

5 CO

.04

1Q

9ft

9(1

.05

.05

19

100. 23

Ab

1.00. 15
464 DATA OF GEOCHEMISTRY. 

Analyses of basic and t'Uaniferous rocks Continued.

Norms.

Q.... ....;...................

or............................

ab............................

an ............................

ns............................

C........ ....................

di.................. ..:.....

hy................. ...........

of.. .........................

mt. ..........................

hm........ .......:...........

il..... .......................

ru ............................

ap......................... ...

pf...........................

Spinel. . ...................

Sulphides. ....................

G

3.89

3.67

 22.24

.10

7.70

1.12

49.88

5.28

1.06

4.03

H

0.56

3.67

5.56

45. 70

20.65

19.00

3.55.

1.15

I

7.38

2.78

11.00

6.95

1.51

22.55

16; 47

19.15

11.42

.42

J

1.10

11.04

58.98

11.76

16. 13

K

0.42

.40

2.88

9.73

64.56

22.18

.62

L

3.34

.52

.61

7.20

3.85

27.84

11.25

.72

13.10

30.74

The foregoing table might be much extended, but it is not necessary to do so.. Other similar rocks are a magnetite syenite porphyry 

(kirunose), described by P. Geijer,1 which contains predominating 

albite with 38.7 per cent of magnetite and minor accessories. Kragerite, from Krageroe, Norway, described by T. L. Watson,2 consists 

largely of plagioclase feldspar with 25 per cent of rutile. Corundum 

spinellite, which occurs in Pittsylvania County, Virginia, has been 

described by Watson and Steiger.3 It is known locally as "rock 

emery" and consists mainly of spinel and corundum, with less 

magnetite and ilmenite. The Canadian urbainite 4 is essentially a 

mixture of ilmenite, hematite, and rutile, with only a few per cent 

of other minerals. The New York (Adirondack) ores,5 of which, 

analyses are given above, are found in close association with norites 

or gabbros. Rocks of this class could hardly be associated with 

persilicic masses, such as granites or syenites. They represent a 

marked deficiency of silica in the magmas from which they came.

LIMITING CONDITIONS.

Although the igneous rocks, as the analyses and descriptions show, 

represent a great variety of mineral mixtures, their proximate constitution is subject to distinct limitations. In the preceding chapter

1 Geol. Kiruna district, Stockholm, 1910, p. 60.

s Am. Jour. Sci., 4th ser., vol. 34,1912, p. 509.

a Jour. Washington Acad. Sci., vol. 8,1918, p. 665.

«See C. H. Warren, Am. Jour. Sci., .4th ser., vol. 33,1912, p. 263.

 Several memoirs on the Adirondack ores are by J. F. Kemp, Nineteenth Ann. Kept. U. S. Oeol. Survey, pt. 3, 1899, p. 383; and Bulls. New York State Museum No. 119, 1908; No. 138, 1910. Also D. H. 

Newland, Econ. Geology, vol. 2, p. 763. An important paper on the Scandinavian ores, by H. Sjogren 

is in Trans. Am. Inst. Min. Eng., vol. 37,1907, p. 809. On the titaniferous iron ores of the United States 

see J. T. Singerwald, Bull. U. S. Bureau of Mines No. 64,1913.
IGNEOUS ROCKS. 465

upon rock-forming minerals some of these limitations were indicated, 

and it was shown that certain species can appear only under certain 

definite conditions. The experiments of Morozewicz and others 

upon the separation of corundum, iolite, etc., from artificial magmas 

are cases in point. It may be well, however, to reiterate some of 

the observations which have already been made or suggested in 

order to properly emphasize these important considerations. For 

this purpose we need only take into account the more conspicuous 

magmatic minerals and neglect the rarer species.

Since nearly all igneous rocks are formed chiefly of silicates, a 

partial table of rock-forming minerals, arranged by bases with reference to maximum and minimum silica, will be convenient. The 

minerals to be thus considered are the following:

Rock-forming minerals.

Base.

Sodium..................

Calcium.................

Magnesium .............

Aluminum. ..............

Maximum silica.

Orthoclase, KAlSi308 . ....

Albite, NaAlSi308 ........

Diopside, CaMgSi.,06 . .....

Enstatite, MgSi03". ........

Pyroxene, FeSiO, ........

Acmite, FeNaSL,06 . ......

Albite, NaAlSi308 . ........

Minimum silica.

Leucite, KAlSio00 . 

Nephelite, NaAlSi04 . 

Anorthite, CaAl2Si208 .o 

Forsterite, MgoSiO,\ ni - Fayalit9,Fe2Si04 /OhvlneMagnetite, Fe304 . 

Corundum, A12 03 .

a Melilite, a basic silicate, is here left purposely out of account, and so, too, is akermanite.

Intermediate minerals, such as analcite, biotite, muscovite, etc., 

that contain water can form only under pressures or conditions of 

viscosity which prevent the. water from expulsion.

The two oxides in the foregoing list can only appear in notable 

amounts when the iron or alumina is largely in excess of the silica. 

The latter will go to the formation of silicates until it is saturated, 

and after that any superfluous oxide can be deposited. This statement, however, demands qualification. Free silica and magnetite 

can coexist in igneous rocks to a very limited extent, but not as principal constituents. The conditions of their coexistence are uncertain, 

but are possibly due to dissociation in the molten magma. It is conceivable that the latter may solidify under circumstances of viscosity 

which prevent some of the separated ions from uniting', so that a little 

quartz and a little magnetite may be present, side by side, in the same 

rock. This explanation, however, is merely speculative and requires 

proof. The exception does not invalidate the broad general statement that the two species are essentially incompatible. Much magnetite and much quartz do not occur together in rocks of igneous origin.

Similar incompatibilities are shown elsewhere in the table. Leucite 

and silica will form orthoclase; nephelite and silica yield albite; a 

member of the olivine .family with silica will be converted into 

113750° 19 Bull. 695 30
466 DATA -OF. GEOCHEMISTRY.

pyroxene, and so on. With an excess of silica over that required to 

generate compounds which appear in the minimum column higher 

silicates will be produced, and as silica is abundant in the lithosphere 

the maximum is most often reached. Feldspar, and pyroxenes are 

much more common than lenad minerals or olivine. The occasional 

concurrence of quartz and olivine in .some basalts and gabbros may 

perhaps be due to the same dissociation as that .suggested by the 

coexistence of quartz and magnetite. The general tendency in a cooling magma is toward the generation of saturated compounds. When 

silica exceeds the,amount which can be taken up by the bases the 

excess appears as quartz, tridymite, or opal, or else it becomes an 

undifferentiated portion of a residual glass.

With adequate silica, then, the number of compounds which a 

magma can yield is small. The persilicic rocks, therefore, are relatively simple in their mineralogical constitution, and in the quantitative classification their modes do not differ very greatly from their 

norms, except with respect to the micas, hornblendes, and augite. 

But as silica diminishes in amount the mineralogical complexity of 

a rock is likely to increase, for the reason that a larger range of 

unions has become possible. For each base a number of compounds 

are capable of formation, and the .same magma, solidifying under 

different conditions, may yield very dissimilar products. In other 

words, we encounter the well-known fact that two rocks may have 

the same ultimate composition and yet contain different mineral 

species. The difficulty of apportioning the several bases to the several minerals in a rock is familiar to everyone who has tried to 

discuss any large number of rock analyses. Potassium may form 

orthoclase, leucite, muscovite, or biotitef sodium may yield albite, 

nephelite, analcite, alkali hornblende, or acinite; calcium appears in 

pyroxene, amphibole, anorthite, or melilite; magnesium in pyroxene, 

amphibole, olivine, or biotite; iron in pyroxene, amphibole, olivine, 

acini te, magnetite, or ilmenite; and aluminum in feldspars, lenads, 

micas, amphibole, pyroxenes, or corundum. The conditions of equilibrium have become exceedingly complicated, and it is only as we 

approach the subsilicic magmas that simplicity is again restored. 

With deficient silica the number of possibilities is lessened and such 

simple rocks as the peridotites and pyroxenites are formed. An 

intermediate magma may be simple from lack of certain constituents, but cases of that kind are exceptional. The mediosilicic rocks 

are as a rule more complex mineralogically than the persilicic or 

subsilicic extremes. The ends of the petrographic series, free silica, 

or free basic oxides, are necessarily the simplest rocks of all. At 

one end we have segregations of quartz; at the other, corundum 

rocks or magnetite. Rocks midway between these extremes, with 

silica ranging from 45 to 55 per cent, contain the greatest variety of 

minerals, for ortho-, meta-, and tri-siiicates are then capable of
IGNEOUS ROCKS. 467

coexistence. In a rock containing silicates of all three classes, with 

alumina, lime, magnesia, the two alkalies, and both oxides of iron 

as bases, the possibilities of union become very numerous. In the 

magma itself the bases will be apportioned to the several .silicic 

acj.ds in accordance with the law of mass action, each one being governed by the relative number of its molecules in a unit volume of 

solution. When cooling begins, the separation of each mineral will 

depend upon its fusibility, its solubility, and its relation to the 

possible eutectic ratios; and the solubility will fluctuate with changes 

in the temperature of the mass. With each deposition of crystals 

all of the foregoing conditions will change, for the composition of the 

residual fluid will have been altered. In theory, then, the physical 

and chemical conditions of solidification are most complex, except 

for two-component and possibly three-component systems. We 

are therefore compelled to deal with the problem of rock composition 

empirically and to make use of rules based upon direct observation. 

These rules are by no means rigorous, for although the separation 

of minerals from a cooling magma generally follows a stated order 

that order often varies. In most cases it is the order described by 

H. Rosenbusch, 1 as follows:

1. Apatite, zircon, spinel, the titanates, and iron ores. These are almost invariably 

the first minerals to crystallize.

 2. The Mg-Fe, Mg-Ca, and Fe-Ca silicates, such as olivine, amphibole, and pyroxene. Biotite is also placed in this class. As a rule the orthosilicates precede the 

metasilicates; olivine, for example, "separating before pyroxene.

3. Feldspars and lenads in the order anorthite, plagioclase, alkali feldspars, nephelite, leu cite.

4. Any excess of quartz.

The frequency with which this order is followed is probably a 

consequence of the fact that most rocks consist mainly of alumosilicates, and especially of feldspars and quartz. That is, they contain predominantly compounds of the same class, in> which the other 

rock-forming minerals are dissolved. The latter separate from solution in the general order of their solubility, the least soluble first; 

but that property varies with the composition of the mixture. In 

an isomorphous series, like the feldspars, the least fusible tend to be 

deposited earlier than the others, but fusibility is a minor factor in 

the process of solidification. Quartz, which solidifies in most cases 

at the very end of the series, is a relatively infusible substance; but, 

as we have already seen, it probably forms a eutectic mixture with 

the feldspars which, by virtue of its depressed melting point, is the 

last part of a magma to congeal. The minor accessories among the 

rock-forming minerals, which crystallize first, although present in 

trifling amounts, possibly form no eutectics with the feldspars. 

Otherwise we should expect them to remain in solution much longer.

1 Elements der Gesteinslelire, 1898, p. 40.
468 DATA OP GEOCHEMISTRY.

PROXIMATE CALCULATIONS.

It is clear, from what has been already said, that it is rarely possible, to predict, with anything like quantitative accuracy, what 

minerals will form when a magma of given composition solidifies; 

Partial and semiquantitative forecasts are practicable; we can say, 

for instance, that the porportion of orthoclase will lie between 

assignable limits; and if the analysis shows a ratio of silicon to 

oxygen lower than Si308 , or 1:2.667, we may be reasonably sure that 

a calculable amount of silica will remain uncombined. Only in the 

simplest cases can a complete forecast be made, and they are exceptional.

Suppose, however, that instead of a magma or an analysis representing a magma and nothing more, we attempt to discuss the composition of a rock in which separate minerals have been identified 

by the microscope. In other words, suppose we have the bulk 

analysis of a rock and also its petrographic description, how far can 

we compute its proximate composition? To this question no single 

answer can be given; in some cases the computation is easy, in others 

it is impossible. The conventional "norms" of the quantitative 

classification can always be calculated, but the actual composition 

may be quite another thing. It is the latter which concerns us now. 

Let us take some concrete examples for discussion.

Two rocks of relatively simple composition are the following, for 

which data are given in the Survey Bulletin 591, and also in Washington's tables.

A. Granite-syenite porphyry, Little Hocky Mountains, Montana. Analysis by H.N. Stokes. Described 

by W. H. Weed and L. V. Pirsson. Contain orthoclase, quartz, oligoclase, muscovite, and iron oxides. 

Liparose.

B. Biotite granite, El Capitan, Yosemite Valley. Analysis by W. Valentine. Described by H. W. 

Turner. Contains alkali feldspar, plagioclase, quartz, biotite, titanite, apatite, and iron oxides. The 

analysis shows that a trace of zircon is probably present also. Toscanosc.

Analyses.

Si02 . ..................

AI o

Fe'A.................

FeO

MnO..................

MgO. .................

fiO

SrO...................

BaO. .................

Na.,0...... ...........

K20.. ....... ..........

H20 .................

IT H r\ i 2O+.... .............

TiOa ..... ............. f-^f\

P O

ci........... ..........

A

68.65 

18.31 

.56 

.08

.12 

1.00 

.10 

.13

4.86 

4.74 

.27

.83 

.20

.03

99. 88

B

71.08 

15.90 

.62 

1.31 

.15 

.54 

2.60 

.02 

.04 

3.54 

4.08

.30 

.22 

.08 

.10 

.02

100. 60

Norms.

Q.. ..................

or. ...................

C. .....................

by....................

nit. ..................

hm .........:.........

A

20.2 

27.8 

40.9 

5.0 

3.5 

.3 

. 2 

.4

B

27.8 

23.9 

29.9 

13.1 

.9 

3.3 

.9
IGNEOUS ROCKS. 469

In calculating the actual composition of these rocks, it is best to 

first eliminate the accessories. Zr02 is calculated as zircon, Fe203 

as hematite or magnetite, P205 and Cl as apatite, and Ti02 as ilmenite, 

titanite, or.rutile, according to the indications given in the petrographic descriptions. All remaining CaO is then reckoned as equivalent to anorthite, and all Na20 as albite. In A the trivial amount 

of MgO is assumed to be in the form MgSi03 , that is, as pyroxene or 

amphibole; in B the magnesia and remaining iron oxide are to be 

computed as biotite, with the normal formula Al2 (MgFe) 2KHSi3Oi2 . 

Upon comparing K20 with the remainder of the A1203 , the latter, in 

A, is found to be in excess of the amount required for orthoclase. 

That excess gives a datum for the calculation of muscovite; and 

when that is deducted, only quartz and orthoclase remain to be considered. The orthoclase is given by the K20 and A1203 still unappropriated, and the remaining free silica represents the quartz. The 

results of the computation are shown below, the trifling amount of 

MnO being consolidated with FeO, and the SrO and BaO with lime. 

A little water is left; unaccounted for, presumably as uncombined 

with any silicate.

Calculated composition of rocks represented in preceding table.

Albite. ........................................................

Biotite..........................................................

MgSi03 . ....................................................... ." J Zircon. .........................................................

Apatite. ........................................................

Ilmenite. ......................................................

Rutile ..........................................................

A

19.98

18. 90

41.07

5.41

13. 06

.30

.17

. 11

.56

99.56

B

29. 64

19.74

29.87

12. 23

6.50

.12

.54

?4

.03

99. 81

These calculations are simple enough, and the results are fairly 

accurate. The chief uncertainties are with the micas, and especially 

with the biotite in B, for rock-forming biotite is a mineral of variable 

composition, and their errors affect the computations with regard to 

orthoclase and quartz. A comparison of the last table with that of 

the norms will show how far the two methods of calculation diverge.

Suppose, however, that we are called upon to discuss the composition of a rock containing orthoclase, plagioclase, biotite, augite, olivine, and magnetite, with the femic minerals present in fairly large 

proportions. In such a case"the alumina goes to form five of the com-
470 DATA OF GEOCHEMISTRY.

portent minerals, iron to four, lime to :two:, .magnesia to three, .and 

potassium to two. We now .need more data than the bulk analysis 

and the usual petrographic description .can give us:, and the .required 

information may be obtained either from chemical or from physical 

sources. Chemically, we may separate the bio.tite, augite, and olivine 

from the rock and analyze each one by itself. In that way we can 

learn something of the distribution of the bases, .and so become able 

to calculate the composition ;of the rock. Or, olivine being soluble 

in very .dilute acids, we may dissolve it out from a known weight of 

rock and determine the .amount of iron and magnesia which belong 

to it. The same procedure may be followed for the determination of 

nephelite when that mineral happens to be present. Physically, the 

rock may be studied in thin sections under the microscope, when the 

areas occupied by the several minerals can be measured with a 

micrometer. Given a sufficient number of such measurements, .and, 

the densities of the minerals being known, the relative proportion of 

the elements may be calculated, and the results obtained can be 

checked by the chemical analysis.1 A cruder process consists in 

taking an enlarged photomicrograph of the thin section, cutting the 

areas representing the minerals out of the paper, and then, by weighing the latter, ascertaining their relative proportions. In some cases 

a rock powder, in known quantity, can be mechanically separated into 

its mineral constituents by means of Thoulet's or other heavy solutions, and the individual portions so determined directly. By one 

method or another the problem of mineral composition can generally 

be solved. Only when a rock contains much glass or other indeterminate matter is the problem incapable-of fairly accurate solution. 

If alteration products are present chlorites, zeolites, kaolin, limonite, 

etc. the discussion of modes becomes very unsatisfactory, and the 

conclusions which are then reached have very slender value.

NOTE. The composition of igneous rocks is often represented graphically by 

means of diagrams, and several methods ior doing this have been devised. For an 

exhaustive memoir upon this subject see J. P. Iddings, Prof. Paper U. S. Geol. Survey 

No. 18, 1903. The, diagrams are of considerable service to the petrographer, for they 

bring chemical relationships and differences vividly before the eye. The triangular 

diagrams of Osann, Min. pet. Mitt., vol. 19, 1900, p. 351, are much used. See also 

papers by F. Becke, idem, vol. 22, 1903, p. 209; L. Finckh, Monatsh. Deutsch. 

geol. Gesell., 1910, p. 285; and B. G. Escher, Centralbl. Min., Geol. u. Pal., 1911, 

pp. 133, 166. The diagrams used by A. Johannsen (Jour. Geology, vol. 25, 1917, 

p. 63) represent a double tetrahedron, with five angles or points of reference. The 

triangular diagrams, obviously, have only .three such .points.

i This method is fully discussed in the Quantitative classification, pt. 3, pp. 186-230, together with the 

subject of calculating norms and modes. According to Ira A. Williams, however (Am. .Geologist, vol..35, 

1905, p. 34), the .micrometer method is-unsatisJactory. -See also A...Rosiwal, y.exhandl. K.-k. gcol. Rtichsanstalt, 1898, p. 143. A. Johannsen (Jour. Geology, vol. 27,1919, p. 276) has described a planimeter 

method for the same purpose. Also with E. A. ^teplenson, idem, .p.. 212, on the Eosiwal meChod.
CHAPTER XII.

THE DECOMPOSITION OF ROCKS. 

THE GENERAL PROCESS.

When a rock is exposed to atmospheric, agencies it undergoes a 

partial decomposition and becomes gradually disintegrated. Some 

of its substance is dissolved by percolating waters, themselves of 

atmospheric origin, and is so carried away; the remaining material, 

partly hydrated and partly unchanged in compqsition, contains 

products which are easily separable from one another. By flowing 

streams the finer clays or silts are taken away from the coarser and 

heavier sand grains, and this process is an important step toward the 

ultimate formation of sandstones and shales. Solution, hydration, 

disintegration, and mechanical sorting are the successive stages of 

rock decomposition. I speak now in general terms. The subsidiary 

agents of decomposition will be considered in their proper connection 

later.

The breaking down of a rock is effected partly by mechanical and 

partly by chemical means. Mechanical agencies, such as the grinding power of glaciers, the pounding of waves, erosion by streams, the 

disruptive effects of frost, or the action of wind-blown sand, tend to 

separate the particles of a rock and to furnish fresh surfaces to chemical attack. Unequal expansion, due to alternations of heat and cold, 

also assist in producing disintegration. 1 The distribution of volcanic 

dust is still another mode by which finely subdivided rock is rendered available for aqueous decomposition. The latter depends for 

its efficiency partly upon the water itself and partly upon dissolved 

acids, salts, or gases. Rain water falls upon the surface of a rock 

and sinks more or less deeply into its pores and crevices. Rain, as 

we have already seen,2 carries oxygen and carbon dioxide in solution, together with other substances in varying proportions. Water 

and gas both exert a solvent action, and the fluid which then saturates the rock becomes charged with the products of solution. These 

may intensify or inhibit further action, according to circumstances. 

Some of the dissolved matter, redeposited, may form a protecting 

film and so delay or prevent further solution. This retardation, 

however, is temporary, for mechanical disintegration is accompanied

1 This subject is fully discussed by J. C. Branner, in his paper upon the decomposition of rocks in Brazil; 

Bull. Geol. Soc. America, vol. 7,1896, p. 255.

2 See ante, pp. 50 et seq.

471
DATA OF GEOCHEMISTRY.

by a rubbing of the loosened particles together, and so the coating 

of insoluble matter is removed.

Normal air contains, in round numbers, 21 per cent by volume of 

oxygen and 0.03 of carbon dioxide. In rain water these active gases 

are concentrated, as shown by the analyses of R. W. Bunsen. 1 Air 

extracted from rain water at different temperatures has the composition by volume given below.

Composition of air extracted from rain ivalcr at different temperatures.

Oxygen. . .......... .o . .................

Nitrogen tt. ...........................

0°

2.92

33.88

63.20

100. 00

5°

2.68

33.97

63.35

100. 00

10°

2.46

34.05

63. 49

100.' 00

15°

2.26

34. 12

63.62

100.00

20°

2,14

34.17

63.69

100. 00

a Including argon.

As waters of this character sink deeper into a rock mass, a portion 

of their effectiveness is lost, for oxygen and cafrbon dioxide are chiefly 

Consumed near the surface, and their share of the chemical effect 

tends to become zero. The decrease in the case of oxygen is clearly 

shown by the experiments of B. Lepsius,2 who has analyzed the gaseous contents of waters from three bore holes of different depth. Air 

extracted from water at 12 meters below the surface contained 24.06 

per cent of oxygen, at 18 meters, 21.97 per cent, and at 25 meters, 

only 12.90 per cent. In rock decomposition, then, oxidation is largely 

a surface phenomenon, and the action of carbon dioxide, so far as it 

is directly obtained from the atmosphere, must follow the same rule. 

Carbonic acid, however, is also derived from other sources, so that its 

effects are not necessarily limited to the upper strata. Its presence 

in ground waters will be considered presently.3

When meteoric waters act upon a mass of rock, the effects produced 

will depend upon the nature of the minerals which they encounter. 

Let us confine our attention for the moment to the more important 

species of magmatic origin, such as the feldspars, micas, pyroxenes, 

amphiboles, olivine, leucite, nephelite, and the typical sulphide, 

pyrite. The last-named mineral, although found in relatively small 

proportions, is nevertheless important, for by oxidation and hydration it yields solutions of sulphates having a distinctly acid reaction. 

These acid solutions act strongly upon other constituents of rocks, 

and intensify the activity of the percolating waters. The sulphates

' Ann. Chem. Pharm., vol. 93,1855, p. 48. See also M. Baumert, idem, vol. 88,1853, p. 17.

8 Ber. Deutsch. chem. Gesell., vol. 18, 1885, p. 2487. Evidence of similar purport has been recorded 

by other observers.

a W. G. Levison, Annals New York Acad. Sci., vol. 19, 1909, p. 121, suggests that the oxygen liberated 

by aquatic plants may assist in the decomposition of rock material.
THE DECOMPOSITION OF BOCKS. 473'

contained in natural waters are largely derived from this source, at 

least primarily. The re-solution of secondary sulphates is of course 

not to be overlooked, but it is obviously a later phenomenon.

SOLUBILITY OF MINERALS.

That nearly all minerals are more or less attacked by water has 

long been known, and also that carbonated waters act still more energetically. The experiments of W. B. and K. E. Rogers,1 in. 1848, 

established these facts conclusively. Many minerals were tested, and 

all were .perceptibly soluble. From 40 grains of hornblende, digested 

during forty-eight hours in water charged with carbonic acid, 0.08 

grain of silica, 0.095 of ferric oxide, 0.13 of lime, and 0.095 of magnesia, or nearly 1 per cent in all, were extracted. 2 In the classical 

investigations of A. Daubre"e 3 3 kilograms of orthoclase, agitated 

with pure water for 192 hours in a revolving iron cylinder, yielded a 

solution containing 2.52 grams of K20, with trifling amounts of 

silica and alumina. Two kilograms of the feldspar, shaken for ten 

days in water saturated with carbon dioxide, gave 0.270 gram of K20 

with 0.750 of silica. A 3 per cent solution of sodium chloride was a 

much less effective agent than /water alone. Leucite was not so 

vigorously- attacked as orthoclase.

In 1867 A. Kenngott 4 showed that many minerals gave an alkaline reaction when in contact with moistened test paper; and in 

1877 R. Miiller 5 published an important .memoir upon, the solubility of various species in carbonated water. The powdered substances were digested in the solvent during seven weeks, and after 

that treatment the dissolved portions were 'quantitatively analyzed. 

The results are summed up below. The percentages of the several 

constituents determined refer to the total amount of each in a given 

mineral; the "sum" is the percentage of all dissolved matter in 

terms of the original substance. That is, under K2 0 1.3527 per cent' 

of the total potash in orthoclase was dissolved, while only 0.328 per 

cent of the entire mineral passed into solution.

1 Am. Jour. Sci., 2d scr., vol. 5,184S, p. 401.

8 The temperature at which the experiment was conducted was 60°, presumably Fahrenheit.

3 Etudes synth6tiques do geologic expgrimentalc, pp. 271-275. See also p. 252 for an experiment upon 

the solubility of granite.

« Ncuos Jahrb., 1867, pp. 77, 769.

»Jahrb. K.-k. gcol. Reichsanstalt, vol. 27, Min. Mitt., 1877, p. 25. Miillcr gives a good summary of previpus work upon the subject, and cites, in addition to the memoirs mentioned here, papers by Dittrich 

Haushofer, Ludwig, Hoppe-Seyler, and others. A later summary, by F. K. Cameron and J. M. Bell, is in 

Bull. No. 30, Bureau of Soils, U. S. Dept. Agr., 1905, p. 12. P. Pichard (Annales chim. phys., 5th ser., 

vol. 15, 1878, p. 529) found that several magnesian silicates gave alkaline reactions with litmus paper. F, 

Sestini (abstract in Zeitschr. Kryst. Min., vol. 35,1902, p. 511) made similar but quantitative observations 

on augite, amphibole, and tremolite. According to F. Cornu (Min. pet.' Mitt., vol. 24,1905, p. 417; vol. 25, 

1907, p. 489), who tested many'minerals with litmus, kaolinite, pyrophyllitc, nontronite, etc., give acid 

reactions. See also E. A. Stephenson (Jour. Geology, vol. 24,1916, p. 180)on the solubility of feldspars 

and hornblende in alkaline solutions.
474 DATA OF: GEOCHEMISTRY.

Material extracted from minerals by carbonated water.

Adularia...

Oil <ynr*l &SP

Do......

Apatite ....

Do.....

Do.....

Serpentine.

Si02 .

0. 1552

.237

.419

Trace.

.873

.354

A12 03 .

0. 1368

9. 1713

Trace.

i

Trace.

K2 0.

1. 3527

Trace.

Na8 0.

2.367

MgO.

1.291

2.649

CaO.

3.213

8.528

1.696

2.168

1.946

P2 06 .

1.417

1.822

2.12

,

FeO.

Trace.

Trace.

4.829

.942

2.428

Trace.

8.733

1.527

Sum. V,

0. 328

.533

1.536 .

.307

1.821

1.529

2. 018 \

1. 976 '

2. Ill x

1.211

The relative solubility of several minerals, chiefly magnesian 

species, in ordinary water was determined by E. W. Hoffmann 1 in 

1882. His method of procedure consisted in allowing water to percolate through the powdered material for two months and measuring the loss of weight; a possibility of gain by hydration seems not 

to have been considered. The data given are as follows:

Relative solubility of'various minerals in ivater.

Epidote. ....................................................

Olivine .....................................................

Chlorite .....................................................

Talc.........................................................

Muscovite ....................... A ..........................

Biotite. .....................................................

Grams 

taken.

4.109

3.353

3.506

2.591

1. 1245

.5058

.9736

Loss of 

weight.

0.064

. .052

.078

.094

.105

.056

.035

The excessive solubility here shown for talc and muscovite is highly 

questionable. Hoffmann's experiments are entitled to very little 

weight. It has been shown by Alexander Johnstone 2 that micas 

exposed to the action of pure and carbonated waters during an entire 

year became hydrated and increased in volume. The latter phenomenon may account for the easy weathering of micaceous sandstones. Muscovite appeared to be insoluble, but in a solution of carbonic acid the biotite lost magnesia and iron. In another communication 3 Johnstone states that olivine is slightly attacked by carbonated water; and in still another 4 he described the action of that 

reagent upon orthoclase, oligoclase, labradorite, hornblende, augite, 

etc. Among the feldspars, orthoclase was the least and labradorite 

the most soluble; hornblende and augite were acted upon even more 

rapidly. These observations seem to be in harmony with those of

1 Inaug. Diss., Leipzig, 1882.

2 Quart. Jour. Geol. Soc., vol. 45,1889, p. 363.

a Proc. Roy. Soc. Edinburgh, vol. 15,1888, p. 436. 

« Trails. Edinburgh Geol. Soc., vol. 5,1887, p, 282.
THE'DECOMPOSITION OF ROCKS. 475

Miiller, whose figures show a similar order of magnitude among the 

determined solubilities.

In recent years a few data have been published by C. Doelter 1 relative to anorthite, nephelite, and some zeolites. The nephelite in particular was strongly attacked by carbonic acid. There are also experiments by F. W. Clarke 2 on the alkalinity of several silicates, 

which were followed by some quantitative determinations by G. 

Steiger.3 Micas, feldspars, leucite, nephelite, cancrinite, socialite, 

spodumene, scapolite, and a number of zeolites were studied, and in 

every case a distinct solubility was observed. Apophyllite, natrolite, 

and pectolite gave remarkably strong alkaline reactions when moistened, but the intensity of the coloration produced with indicators 

gave inaccurate information as to the extent to which decomposition 

had occurred. Between the qualitative and the quantitative data 

there were discrepancies, which have been cleared up only within the 

last few years. A. S. Cushman,4 in his work upon rock powders, has 

shown that when orthoclase is shaken with water an immediate extraction of alkaline salts takes place, but it is only a partial measure 

of the amount of decomposition. Colloidal substances, silica or 

aluminous silicates, are formed at the same time, which retain a portion of the separated alkali, but give it up to electrolytic solvents. 

For example, 25 grams of orthoclase were shaken up with 100 cubic 

centimeters of distilled water. The mixture was filtered, and the 

filtrate on evaporation gave 0.0060 gram of residue. With a 2 per 

cent solution of ammonium chloride a soluble residue of 0. 0608 gram 

was obtained. With diabase 25 grams in pure water yielded an 

extract of 0.0064 solid residue; with a 1 per cent solution of ammonium chloride it gave 0.1412 gram. These gains do not imply increased 

decomposition, but only a liberation of the soluble compounds which 

had been entangled in the colloids that were formed at the same time. 

Any salt in solution is likely to affect in some such manner the apparent solubility of a rock or mineral, a conclusion which is in harmony 

with many observations upon the tendency of soils and clays to 

absorb salts, and especially salts of potassium, from percolating 

waters. As the latter change in composition, their decomposing and 

dissolving capacities are altered; and since the rocks differ in composition, no general rule can be laid down to determine what the effects 

of water in any particular case will be.

i Min. pet. Mitt., vol. 11,1890, p. 319.

s Bull. U. S. Geol. Survey No. 167,1900, p. 156.

«Idem, p. 159.

* U. S. Dept. Agr., Bur. Chemistry, Bull. No. 92, 1905, and Office Pub. Roads, Circular No. 38. See 

also A. S. Cushman and P. Hubbard, Jour. Am. Chem. Soc., vol. 30,1908, p. 779, on the electrolyticextrac-. 

tion of potash from feldspars. Observations similar to Cushman's have been made by O. Andrtf, Compt. 

Rend., vol. 157, p. 856,1913. Other papers on the solubility o£ rocks are by W. G. Levison, Bull. New 

York Mincralogical Club No. 2,1909; W. Funk, Zeitschr. angew. Chemie, vol. 22,1909, p. 145; J. Dumont, 

Compt. Rend., vol. 149,1909, p. 1390; F. Henrich, Zeitschr. prakt. Geologie, 1910, p. 85; F. Sicha, Inaug. 

Diss., Leipzig, 1891; and C. H. Sinyth, jr., Jour. Geology, vol. 21, p. 105,1913.
476 DATA OF GEOCHEMISTRY.

Still, in spite of difficulties and uncertainties, we can trace the 

course of rock decomposition along several lines. The evidence, 

both as found by experiment in the laboratory and by field observations, shows that practically all minerals, certainly all of the important 

ones, are attacked by water and carbonic acid. The pyroxenes and 

amphiboles yield most readily to waters, then follow the plagioclase 

feldspars, then orthoclase and the micas, with muscovite the most 

resistant of all. Even quartz is not quite insoluble, and the corrosion 

of quartz pebbles in conglomerates has been noted by several observers.1 Among the commoner accessories apatite and pyrite are 

most easily decomposed, magnetite is less attacked, and such minerals 

as zircon, corundum, chromite, ilmenite, etc., tend to accumulate 

with little alteration in the sandy rock residues. These minerals are 

not absolutely incorrodible, but they are nearly so. Corundum, for 

example, slowly undergoes hydration,2 and is converted, at least 

superficially, into gibbsite or diaspore.

The effect of rain water upon a rock must now be divided into several phases. First, it partially dissolves the more soluble minerals, 

with liberation of colloidal silica, and the formation of carbonates, 

containing lime, iron, magnesia, and the alkalies. The iron carbonate 

is almost instantly oxidized, forming a visible rusty coating or precipitate of ferric hydroxide. The lime, magnesia, and alkali salts 

remain partly in solution, to be washed away, together with much of 

the dissolved silica.

The character of the solution thus formed by the decomposition of 

feldspathic rocks has been investigated by W. P. Headden.3 After 

prolonged treatment of orthoclase with water containing carbonic 

acid, he obtained a solution which, upon evaporation, yielded a residue carrying over 40 per cent of silica.

The second phase of the process is represented by a hydration of the 

undissolved residues. The feldspars are transformed into kaolin, the 

magnesian minerals into talc or serpentine, the iron, as we have seen, 

becomes essentially limonite, and the quartz grains are but little if 

at all changed. This double process of solution and hydration is accompanied by an increase of volume, which may or may not assist 

in effecting disintegration. On the surface, the weathered rock 

crumbles easily; but if the alterations have taken place at considerable depths the pressure due to expansion may hold all the particles

> See C. W. Hayes, Bull. Geol. Soc. America, vol. 8,1897, p. 213; M. L. Fuller, Jour. Geology, vol. 10,1902, 

p. 815; C. H. Smyth, Am. Jour. Sci., 4th ser., vol. 19,1905, p. 282. For the solubility of quartz in solutions 

of borax or of alkaline silicates, see G. Spezia, Jour. Chem. Soc., vol. 78, pt. 2, 1900, p. 595; vol. 80, pt. 2, 

1901, p. 605. The corrosion of quartz is attributed by G. P. Merrill (Rocks, rock weathering, and soils,' 

2d ed., p. 252) to alkaline carbonates generated during the decomposition of feldspars. For an elaborate 

research upon the solubility of gelatinous silica, see V. Lenher and H. B. Merrill, Jour. Am. Chem. Soc., 

vol. 39,1917, p. 2630. The authors give many references to literature. 

'S. J. Thugutt, Mineralchemische Studien, 1901, p. 104.

* Am. Jour. Sci., 4th ser., vol. 16, 1903, p. 181.
THE DECOMPOSITION OF EOCKS. = 477

-/ in place and the rock will seem at a first glance to be unaltered. Such 

a rock, although apparently solid when it is first exposed to the air, 

rapidly falls to pieces and becomes a mass of sand and clay. This 

peculiarity was noted by G. P. Merrill 1 in certain granites of the 

District of Columbia, and by 0. A. Derby 2 at railway cuttings in

** Brazil. In the latter case, the rocks, when first uncovered, were so

J hard that they were removed by blasting; but they soon underwent a 

sort of slacking process and crumbled away.

By solution, oxidation, and hydration, then, a solid rock is con-

' verted into an aggregate of loose material, which may remain in place 

as soil or be removed by the mechanical agency of running waters.

"* As a rule the chemical processes are incomplete; some of the minerals

1 are not entirely altered, and the loose products therefore exhibit 

many variations. In general terms, the streams separate the dis^- 

integrated materials into coarser and finer or lighter and heavier 

portions. The claylike substances are generally light and finely 

divided, and therefore remain longest in suspension. The heavier

^ sands and gravels are not carried so far, and thus a separation is 

effected. In these coarser portions are found quartz, together with 

undecomposed fragments of the various minerals; the lighter silts 

are less variable in composition. Between silt and sand, however, 

there are all possible gradations, and a corresponding diversity is 

shown in the rocks that are formed by their reconsolidation. Mud, 

sand, and gravel yield shales, sandstones, and conglomerates; but 

there are sandy shales and argillaceous sandstones. The separations 

are sometimes fairly complete, but they are oftener imperfect. Swift 

waters are more effective than sluggish ones, both as regards prompt-

^ ness of action and the thoroughness of the separations. A mountain torrent becomes quickly turbid and quickly clear, while a river 

flowing through a flat alluvial country is rarely free from discoloration by suspended sediments. Much silt goes to the ocean; the coarser 

sands and gravels subside near the place of their origin. I speak 

now of stream deposits, but the sands of the seashore, which represent disintegration through the action of waves, follow similar rules. 

The gravelly portions are left highest on the beach, then come the 

sands, and the lighter particles are carried away to be laid down as

oceanic ooze. ,->

But rain water is not the only chemical agent for effecting rock

decomposition. Below the surface the ground water is at work, and

that contains an accumulation of the salts formed during the earlier

stages of the process. It is poorer in oxygen than the surface waters,

' but richer in other substances, and it may contain a large proportion

 BuJl. Geol. Soc. America, vol. 6,1895, p. 321.

* Jour. Geology, vol. 4,1890, p. 529. Holland (Quart. Jour. Geol. Soc., vol. 59,1903, p. 64) mentions deep 

.-, cuttings in India where the minute structure of the gneiss is retained on surfaces as soft as putty.
478 = DATA OF GEOCHEMISTRY.

of organic matter derived from the decay of vegetation. This 

organic matter often reverses the oxidation which had previously 

taken place, reducing ferric to ferrous compounds and sulphates to 

sulphides. Pyrite, dissolved away from the surface rocks, may reappear as marcasite elsewhere. Furthermore, the organic decomposition furnishes large amounts of carbonic acid to the ground water, 

and so increases its activity. At the surface ferrous salts have 

yielded the insoluble ferric hydroxide; in the soil, by reduction, the 

solubility is partly restored and in the form of ferrous bicarbonate 

the iron may be more or less washed away. When alkaline carbonates have been generated in the ground water its solvent power is 

increased, and it then becomes an effective agent in the solution and 

redeposition of silica.1 The impregnation of any solution of alkaline 

salts by free carbonic acid yields a solvent of this kind. Ground 

water, then, is in many ways different from rain water. As the latter 

sinks deeper and deeper into a mass of rock or soil it undergoes progressive modifications, and some of the changes which it brought 

about at the beginning of its career may be reversed, while others are 

accentuated. At certain depths the decomposing action of the water 

may cease almost entirely, when the process of cementation begins, 

and then new rocks are generated. The subject of reconsolidation, 

however, belongs in another chapter.

In volcanic regions the gaseous emanations play an important part 

in altering the rocks, and so, too, do the acid solfataric waters. In 

previous chapters these gases and waters have been sufficiently 

described, and then1 powerful solvent effects were noted.2 Hot waters 

charged with sulphuric or hydrochloric acid, attack nearly all eruptive rocks, dissolve nearly all bases, and leave behind, in many cases, 

mere skeletons of silica. This thorough disintegration of lavas, 

however, is only local, and has not the wide general significance of 

the gentler, less noticeable effects produced by rain.

EFFECTS OF VEGETATION.

Vegetation exerts a profound influence in the decomposition of 

rocks. Even if plants did no more than to retain moisture, making 

the rock beneath them damp, their action would be important; but 

that is only part of the story. The roots of plants penetrate into 

the crevices of the rocks, and as they expand by growth, they help

1 See E. W. Hilgard, Am. Jour. Sci., 4th ser., vol. 2,1896, p. 100. Hilgard suggests that the inclusions of 

carbon dioxide found in quartz may supply notable quantities of that substance to underground waters.

8 In addition to previous references, see W. B. Schmidt, Min. pet. Mitt., vol. 4,1882, p. 1, on the action of 

sulphurous acid upon volcanic rocks, and H. Lotz, Dissertation, Giessen, 1912. The action of hot solutions 

not necessarily acid, has been compared with the effects of weathering by E. Steidtmann, Econ. Geology, 

vol. 3,1908, p. 381. An important memoir on weathering, by K. D. Glinka, is in Trav. Soc. Imp. Nat. St. 

P6tersbourg, vol. 34,1906, p. 1. On the decomposition of basalt, see H. Stremme, Monatsh. Deutsch. geol. 

Gesell.,1910,p. 180.
THE DECOMPOSITION OF ROCKS. 479

mechanically in the work of disintegration. 1 The roots, moreover, often contain organic acids, which act with much vigor upon 

mineral substances. The soil or decomposed rock about the roots of a 

tree is often bleached by the solution and removal of its iron contents. 

The studies of H. Carrington Bolton 2 upon the solubility of minerals in organic acids, and especially in citric acid, show how powerful this action must be. This acid decomposes many silicates, even at 

ordinary temperatures. Furthermore, plants take large amounts of 

mineral matter from the soil, which is returned to it in a different 

condition after the vegetation dies. Lichens, especially, extract 

substances directly from the rocks on which they grow; grass and 

grain crops absorb much potash, and so on. These substances are 

found in the ash when vegetable matter is burned, and are easily 

determined by analysis.3

The number of organic acids which find their way into the soil, 

from one source or another, is quite considerable, and their action 

deserves a much more systematic investigation than it has yet 

received. In past years great importance was attached to the so-called 

"humus acids," the products of vegetable decay. These substances, 

however, are not true acids at all, but vague mixtures of colloids 

whose precise chemical nature is yet to be determined. They have 

some geologic significance, and H. Gedroiz 4 has shown that their 

alkaline solutions, percolating downward, and meeting lime salts, are 

precipitated, forming the impervious layer known as hardpan. They 

also act as reducing agents, and so aid in the formation of pyrite or 

marcasite and in the deposition of iron carbonates. Their alleged 

activity as solvents of silica or as agents in rock decomposition is 

most questionable. Moor waters are commonly acid, but, as K. 

Endell 5 has proved, the acidity is usually that of carbonic acid, 

whose value as a solvent of minerals has already been discussed. 

The humus substances are also held in solution by alkaline carbonates, 

which readily dissolve silica. 8

1 See A. Geikie, Textbook of geology, 4th ed., p. COO, and G. P. Merrill, Rocks, rock weathering, and soils, 

p. 201.

2 Annals New York Acad. Sci., vol. 1, 1877, p. 1; vol. 2, 1880, p. 1.

» On this theme there are abundant data, which have been collected principally with reference to agricultural problems. A long table of ash analyses may be found in Jahresb. Chemie, 1847-48, p. 1074. For 

estimates of the amount of mineral matter taken from the soil by hemp and buckwheat, see R. Peter, 

Kentucky Geol. Survey, Chemical analyses, vol. A, 1884, p. 441.

dChem. Abstr., 1909, p. 2600. From Jour. exp. Landw., vol. 9, 1908, p. 272.

8 Neues Jahrb., Beil. Band 31, 1910, p. 1, and Jour, prakt. Chemie, 2d ser., vol. 82,1910, p. 414.

* See A. A. Julien's monographic paper upon the geological action of the'humus acids, Proc. Am. Assoc. 

Adv. .Sci., 1879, p. 311, for a complete summary of the earlier work, now mostly obsolete, on this subject. 

Recent papers by A. Baumann and E. Gully, Mitt. K. Bayr. Moorkulturanstalt, Heft 3,1909, p. 52, and 

Heft 4,1910, p. 131, are important, and also two .by H. Stremme., Zeitschr. prakt. Geologic, 1909, p. 353; 

1910, p. 389. The recent literature upon the humus acids is very voluminous.
d80 DATA OF GEOCHEMISTRY.

INFLUENCE OF BACTERIA.

Even forms of life so low as the bacteria seem to exert a definite 

influence in the decomposition of rocks. A. Muntz 1 has found the 

decayed rocks of Alpine summits, where no other life exists, swarming with the nitrifying ferment. The limestones and micaceous 

schists of the Pic du Midi, in the Pyrenees, and the decayed calcareous schist's of the Faulhorn, in the Bernese Oberland, offer good 

examples of this kind. The organisms draw their nourishment from 

the nitrogen compounds brought down in snow and rain; they convert the ammonia into nitric acid, and that, in turn, corrodes the calcareous portions of the rocks. A. Stutzer and R. Hartleb 2 have 

observed a similar decomposition of cement by nitrifying bacteria. 

The effects thus produced at any one point may be small, but in the 

aggregate they may become appreciable. J. C. Branner,3 however, 

has cast doubts upon the validity of Muntz's argument, and further 

investigation of the subject seems to be necessary. That microbes 

exert a great influence in the soil is beyond question. Apart from 

the effects produced by nitrification, the germs aid in bringing 

about the decomposition of organic matter, and in that way enormous 

quantities of carbon dioxide are generated. Furthermore, some 

species decompose sulphates,4 and so modify the composition of the 

ground water.

INFLUENCE OF ANIMAL LIFE.

The influence of animal life in decomposing rocks is perhaps secondary rather than initiative. An ordinary soil contains rock-forming minerals which have been incompletely broken down, and animals 

assist in completing the disintegration. The effects produced by 

guano upon the rocks immediately beneath it may be more direct, but 

its distribution is exceedingly limited. On the other hand, burrowing animals bring fresh soil to the surface to be acted upon by 

rain or blown away by winds; and ordinary earthworms perform 

this kind of labor upon a vast scale. In Brazil, as shown by J. E. 

Mills 5 and J. C. Branner,6 the work done by ants is of the greatest 

'significance. These creatures dig tunnels hundreds of yards long and 

carry into their nests great quantities of leaves. Through their vital 

processes they generate carbon dioxide, and the decay of the leaves 

must develop much more. The ants not only open up the soil to the 

action of air and water, they also help -to saturate it with carbonic 

acid, and the solutions so produced, by the joint action of rain,

i Annales chim. phys., 6th ser., vol. 11,1SS7, p. 13G; Compt. Rend., vol. HO, 1890. p. 1370. 

8 Zeitschr. angew. Chemie, 1899, p. 402. 

»Am. Jour. Sci., 4th ser., vol. 3,1897, p. 438.

<See ante, p. 146. See also E. C. Harder (Prof. Paper U. S. Geol. Survey, No. 113, 1919) on the iron 

bacteria.

» Am. Geologf^t, vol. 3,1889, p. 351. 

6 Bull. Geol. Soc. America, vol. 7,1890, p. 255; vol. 21,1910, p. 449.
THE DECOMPOSITION OF ROCKS. 481

respiration, and organic decay, penetrate to considerable depths below 

the surface. The decomposition of the underlying rocks is thus 

distinctly promoted and over great areas of territory.

Before passing on to consider the products of decomposition, a 

word must be said upon the destructive influence of man. By draining, grading, irrigating, fertilizing, and cultivating the soil, by tunneling, quarrying, and mining, the processes of rock decomposition 

are promoted in many ways. New surfaces of rock are exposed to 

the action of air and water, new solvents are introduced into the soil, 

coal is withdrawn from the earth to be restored to the atmosphere as 

carbon dioxide, and by the destruction of forests erosion is accelerated. The extent to which man assists in the decomposition of 

rocks may easily be overrated; but human influence is one of the 

active agencies which can not be ignored.

PRODUCTS OF DECOMPOSITION.

The products of decomposition are commonly divided into two 

great classes, the sedentary and the transported. The sedentary 

products are those which remain in place, such as residual clays; the 

transported materials are represented by glacial drift, river silt, windblown dust, etc. On the one hand we deal with substances derived 

from a single lithologic unit; on the other we have blended or assorted 

materials from various sources. Corresponding to these differences 

of origin there are chemical differences. First in order let us consider the sedentary products.

When a rock is decomposed in place, the changes produced are relatively simple. Soluble constituents are leached away and, to offset 

the loss, oxygen, water, and often carbon dioxide are gained. Ordinarily the gains exceed the losses, both in weight and in bulk, and the 

change may be either complete or partial. Every gradation is possible, from incipient alteration to the most thorough decomposition. 

The character of the products formed will depend upon the composition of the original rock, and also upon the nature of .the. decomposing 

agents. A normal granite, for example, will yield a mixture of 

quartz, kaolin, and scales of mica, commonly commingled. with 

fragments of undecomposed feldspar; a peridotite is converted into 

serpentine; a rock rich in iron is likely to give much ferric hydroxide, 

and so on. The more easily alterable minerals naturally form the 

more easily alterable rocks, and the residues which they furnish will 

represent the maximum amount of change. That change, furthermore, will be reflected in the composition of the percolating waters, 

which may be rich in silica, or carbonates, or sulphates, according to 

the nature of the minerals upon which they operate.

113750°-^19 Bull. 695 31
482- DATA - OF' GEOCHEMISTRY.

. Many comparative-analyses of rocks and their, decomposition products are on record: 1 The following analyses, representing a few typical examples, are enough for present purposes:

Analyses of rocks and their decomposition products.

A. Micaceous granite, District of Columbia. Described by Merrill, Bull. Geol. Soc. America, vol. 6, 

1895, p. 321. Contains quartz, black mica, feldspar, epidote, apatite, flakes of sericite, and a few black tourmalines and iron ores, a, The fresh rock; b, partly decomposed rock; c, derived soil; d, fine silt, separated 

from soil. Analyses a, b, c, by R. L. Packard; d, by G. P. Merrill.

B. Micaceous gneiss, Albemarle County, Virginia. Analysis and description by G. P. Merrill, Bull. Geol. 

Soc. America, vol. 8,1897, p. 157. The rock contains orthoclase, plagioclase, black mica, zircon, quartz, iron 

ores,apatite, garnets, and a zeolite, a, The fresh rock; b, the residual soil.

C. Elseolite syenite, Fourche Mountain, Arkansas. Described by J. F. Williams, Ann. Rept. Arkansas 

Geol. Survey, 1890, vol. 2, pp. 81-82. a, The fresh rock, analyses by W. A. Noyes; b, c, the decomposed 

rock, partial analyses by R. N. Brackett.

D. Augite andesite, Rockland Ridge, Washington. Analyses, description, and full discussion by E. A. 

Schneider, Am. Jour. Sci., 3d ser., vol. 36,1888, p. 236. According to A. W. Jackson, the rock contains 

plagioclase, augite, apatite, magnetite, and residual glass, a, The fresh rock; b, the derived soil.

SiO,. ................

\l A

FeA..... ...........

FeO........... .......

MgO. ................

CaO.................

Na20................

K.,0.. .......... ......

Ti(X.................

P,0j. .:........:.....

SiO

Al O

Fea08 ...... ...........

FeO.................

MgO................

CaO..................

Na20...... ...........

KaO... ..............

Ignition. ............

H20........ .........

Organic..........,.:.

Ti02 ................

P O

so,.. ................

1

a

60.69

16.89

1 9.06

1-06,

4.44

2.82

4.25

.62

.25

100. 08

}

b

45.31

26.55

1 12.18

.40

Trace.

.22

1.10

13.75

.47

99.98

a

59.70

18.85

1 4.85

..68

1.34

6.29

5.97

1.88

99.56

a

69.33

14. 33

3.60

2.44

3.21

2.70

2.67

1.22

Undet.

.10

99.60

C

b

58.50

25.71

| 3.74

Trace.

.44

1.37

1.96

5.85

97.57

.A

b

66.82

15.62

1.88

1.69

2.76

3.13

2.58

2,04

3.27

Undet.

Undet.

99.79

c

50.65

26.71

1 4.87

.21

.62

.62

1.91

8.68

.06

94. 33

c

65 V 69

15.23

1 4.39

2.64

2.63

2.12

2.00

4.70

.31

.05

99.76

]

a

50.85

12.54

10.03

7.11

5.57

9.33

2.37

1.13

.34

.76

.05

100. 08

d

49.39

23.84

| 3.69

4.60

4.41

3.36

2.49

8.12

99.90

3

b

58.16

15.03

10.59

1.99

4.57

2.56

1.68

1.77

3.52

.43

.07

100. 37

1 For a good general discussion of the data, see G. P. Merrill, Rocks, rock weathering, and soils, pp. 206- 

2iO. See also papers by J. Lemberg, Zeitschr. Deutsch. geol. Gesell., vol. 27,1875, p. 581; vol. 28,1876, p. 

519; vol. 35,18S3, p. 559. Other groups of analyses than those cited here are given by E. Kaiser, Zeitschr. 

Deutsch.geol. Gesell., vol. 56, Monatsb., 1904, p. 17; and M. Dittrich,Zeitschr. anorg. Chemie, vol.47,1905, 

p. 151.
THE DECOMPOSITION OF ROCKS. 483

Analyses of rocks and their decomposition products Continued.

E. Diabase, Medford, Massachusetts. Analyses and discussion by G. P. Merrill, Bull. Geol. Soc. America, vol. 7,1896, p. 350. According to W. H. Hobbs the rock contains plagioclase, augite, biotite, pyrite, 

apatite, magnetite, ilmenite, and some secondary products, a, The fresh rock; b, disintegrated rock; c, 

fine silt. For data concerning a diabase from Chatham, Virginia, see T. L. Watson, Am. Geologist, vol. 

22,1898, p. 85. The analyses given are not complete.

¥. Diorite, Albemarle County, Virginia. Described and analyzed by G. P. Merrill, Eocks, rock weathering, and soils, pp. 224,225. Contains hornblende, plagioclase, and titanic iron, a, The fresh rock; b, decomposed rock.

,G. Diabase, Spanish Guiana, Venezuela. Described byG. Attwood, Quart. Jour. Geol. Sqp., vol. 35, 

1879, p. 580. Analyses made in the Royal School of Mines, London, a, The fresh rock; b, weathered rock; 

c, highly weathered rock.

H. Diabase, Island of Jersey. Described by P. Holland and E. Dickson, Proc. Liverpool Geol. Soc., 

vol. 7,1892-93, p. 108. a, Tho fresh rock; b, decomposed rock. Holland and Dickson also give data relative 

to the decomposition of a granite and a sandstone.

J. Augite diorite, Magnetberg, southern Urals. Described by J. Morozewicz, abstract in Zeitschr. Kryst. 

Mm., vol. 39,1904, p. G12. The rock alters, first by leaching, free iron oxides being dissolved and partly 

redeposited in crevices; second', by chloritization of the augite and production of.garnet microlites; finally 

by kaolinization of the feldspars, a, The fresh rock, specific gravity 2.988; b, first stage of decomposition, 

specific gravity 2.918; c, second stage, specific gravity 2.604.

Si02 .....

AljO,....

Fe203 ....

FeO

MgO.....

CaO.....

Na.,0....

JC.6......

Ignition 1° O . .

MnO.....

SiOo......

A1203 .... 

Fe203 ----

FeO.....

MgO..... 

CaO......

NaoO..... 

K26.....

H20-... 

II20+... 

Ti02 ......

C02 ......

MnO.....

Mn203 ....

a

49.57

15.37

12.34

7.41 

9.65

1.99

.85

.17 

3.10

Trace.

a 100. 45

G

b

41.77

19.34 

13.21

4.63

5.01 

4.98

.83 

.69

2.55 

7.30

Trace.

a 100. 31

c

43.46

18.39 

20.43

3.46 

2.37

.14 

.59

3.39 

7.95

Trace.

a 100. 18

a

47.28

20.22

3.66

8.89

3.17

7.09

3.94

2.16

2.73

.68

.77

100. 59

I

a

43.56

14.58 

3.84

7.00

9.95 

10.78

1.86 

1.02

[ 3.85 

1.03

1.93

.39

99.79

E

b

44. 44

23. 19

1 12.70

2.82

6.03

3.93

1.75

3.73

.70

.52

99. 81

I

b

44.93

16.27 

13. 37

6.40 

1.84

2.03

.84

| 12.55 

1.34

.28

99.85

c

36. 61

i 40.68

4.02

3.44

2.14

1.82

10.97

99.68

a

46.97

16. 16 

10.66

4.38

4.56 

9.02

4.47 

1.26

\ 1.74 

.14

.75

100. 11

a

46.75

17.61

1 16.79

5.12

9.46

2.56

.55

.92

.25

100. 01

I :

b

50.42

16.72 

4.32

2.70

3.77 

13.36

4.24 

1.52

1 2.24 

.07

.68

100. 04

F

b

42. 44.

25. 51

1 19.20

21

.37

.56

.49

10.92

.29

99.99

c

47.22

20.09 

5.51

9 09

4.39 

6.93

2.56 

1.52

1 8.78 

Trace.

.66

99. C8

o Including traces of Cu and S. P absent.
484 ;DATA OF GEOCHEMISTRY.

All these comparative groups tell essentially -the same story. Oxidation of the iron compounds, assumption of water, and loss of 

soluble bases by leaching are changes which can be recognized at a 

glance. The concentration of the slightly soluble alumina and 

ferric oxide in the residual substances is also clearly apparent.. But 

the true magnitude of each alteration is not so easily seen. In some 

cases the changes appear to oe small, when actually they are quite 

noteworthy. The apparent gains in alumina are only relative, and 

so, tooj are all the other percentage variations. In order to determine the true alterations we must eliminate the disturbances due 

to oxidation and hydration, and this may be done either by examining molecular ratios or by assuming that one rock constituent is 

constant and comparing the others with it. The latter method 

is the most used and has been applied by Merrill to the several 

groups of analyses studied by him. Either ferric oxide or alumina 

is taken as invariable, and from that as a standard the relative losses 

of the other constituents can be roughly estimated. The process is 

not rigorously exact, but it gives a fair conception of what has really 

occurred. The alumina is -not absolutely insoluble, but, relatively 

to the other bases, it is very nearly so. .......

For four of the rocks under - consideration Merrill gives the 

following computations. The first table shows the .percentage of 

each constituent lost by the original rock. The second table gives 

the percentage lost by each substance referred to its total amount

as 100.

Results of decomposition of certain rocks.

I. Percentage' of rock lost.

Si02 .. .......................

A1203 --. .....................

FeO, Fe203 - .................

MnO........................

MgO.......... ...............

CaO.. .......................

No f)

K o

P O

Granite.

10.50

.46

.36

.81

.77

.85

.04

13, 79

Gneiss.

31. 90

Standard.

1.30

.80

4. 44

2.68

3.55

44.67

Diabase.

. 8.48

Standard.

 2.42

.32

.68

1.83

.50

fi9

.08

14.93

Dioritc.

17 43

Standard.

3

KO

4 Q7

9.20

917

91

37.51

II. Percentage of loss of each constituent.

SiOa- ........................

AI n

FeO, Fe203 - - ................

MnO.........................

MgO.........................

CaO.........................

Na20.......... ..............

KaO.. ........................

P O

Granite.

14.89

3.23

1 4Q

.OK 01

28!62

' 31 Q8

40. CO

Gneiss.

KO 4£

14.35

74. 70

100. 00

95.03

' ' ' JM ^9

Diabase.

18.03

18.10

41.57

 91 70

25.89

12.83

OO T C

11.39

Diorite.

Q7 qi

Standard.

91 0°.

Q7 17

Q7 °.ft

R4 R7

qo 7C

. 1 Q ft-7
THE DECOMPOSITION OF ROCKS. 485

From these figures we can see more clearly what has happened to 

each rock, but we can not compare the four columns with one another. 

There are still too many variables. The rocks contain different 

minerals, they have weathered with varying completeness, and 

they were not exposed to the same percolating waters: Furthermore, weathering is affected by the texture of a rock, and a compact 

feldspar will change less readily than one which is full of crevices. 

Coarseness or fineness is another factor to be take into account. 

In short, the quantities are incommensurable and no general rules, 

except as to the main tendencies to alteration, can be based upon 

them. Each individual rock alters in accordance with the conditions 

to which it has been exposed, but the general trend of the changes 

is always in the same direction. Lime is always removed, but percolating waters rich in carbonic acid will carry it away more easily 

than waters less heavily charged. The lime-soda feldspars decompose 

more readily than orthoclase or microcline. Olivine will lose magnesia 

more readily than enstatite. The solubility of silica will vary with 

variations in the leaching agent. Material withdrawn at one point 

may be redeposited at another. Local and temporary conditions 

meet us at every turn; so that although we can tell, in broad,-general 

terms, how a given rock will change, we can not predict the alteration 

in its quantitative details.

RATE OF DECOMPOSITION.

The extent to which rocks undergo decomposition within a given 

time is largely dependent upon climatic circumstances. In the 

polar regions, where waters are frozen during a great part of the 

year, solution goes on more slowly than in warmer climates. In the 

Tropics the waters not only act continually, but their energy is 

increased by their higher temperatures. Frost is most effective as an 

agent of disintegration in climates where alternations of freezing and 

thawing are most frequent. As E. W. Hilgard 1 has well said, 

"The chemical processes active in soil formation are intensified by 

high and retarded by low temperatures, all other conditions being 

equal." Disintegration, however, as distinguished from decay, is 

very active in high latitudes and also in arid regions.2 In both 

cases the great alternations of heat and cold promote disintegration, 

whereas, for lack of flowing water, solution and erosion are retarded. 

In an arid region the diurnal variations of temperature are extreme, 

and inequalities of expansion among the minerals of a rock produce 

their maximum effects. Furthermore, the dust and sandstorms of a 

desert advance the disintegrating process. The rocks are ground to

1 Report on the relations of soil to climate: Bull. No. 3, U. S. Weather Bureau, 1892. 

a See I. C. Russell,.BuU. Geol. Soc.-America, vol. 1, 1890, p. 135. Also compare G. P. Merrill, Rocks, 

rock weathering, and soils, pp. 278, 285.
486 DATA OF GEOCHEMISTRY.

powder, but much of the de'bris remains in place and loses comparatively little by leaching. In humid climates erosion and solution go 

on together, and an abundance of vegetable matter, living or dead, 

helps to hasten the decomposition of the rock-forming silicates. 

Between soils of arid and moist climates there are striking differences 

of composition, as Hilgard * has clearly shown by means of the following averages. Under A is given the average composition of 466 

soils from the humid regions of the Southern States. B represents 

the average of 313 soils from the arid areas of California, Washington, 

and Montana.

Average composition of soils from humid and arid regions.

Insoluble in HCL . ..........................................

Soluble Si02 ................................................

A1203 .. ....................................................

FeA......................................................

Mn,04 -- . ..................................................

MgO.. .....................................................

CaO. ......................................................

N^O. .....................................................

K20.. ......................................................

p o

863.........................................................

Water and organic matter. ...................................

A

84. 031

4.212

4.296

3.131

.133

.225

.108

.091

^ .216

.113

.052

3.644

100. 252

r.

70.565

7. 266

7.888

5.752

.059

1.411

1.362

.264

.729

.117

.041

4.945

100. 399

That a much greater proportion of soluble matter, unremoved by 

leaching, is present in the arid regions is evident at a glance. The 

desert soils, when supplied with water, are exceptionally fertile, 

because they have retained in a large measure the foods that plants

require.

KAOLIN.

The chemical products of rock decomposition are extremely varied, 

as might be naturally inferred from the mineralogical complexity 

of the original masses. In the residues which remain after leaching 

we find free silica, either as quartz or opal, fragments of various 

undecomposed minerals, hydroxides, and a number of the rather 

indefinite substances known as clays. Among the latter kaolinite, 

H4Al2Si209, and its ferric equivalent, nontronite, H4Fe2Si209 , are 

perhaps the most important.2 These species occur admixed with 

one another and also with other hydrous silicates, opaline silica, 

and hydroxides. Kaolinite is a very stable compound, but nontronite is easily decomposed, either by acid or alkaline solutions,

» Op. cit., p. 30.

2 This equivalency between kaolinite and nontronite was suggested by E. Weinschenk, Zeitschr. Kryst. 

Min., vol. 28,1897, p. 150. A. Bergcat, however (Centralbl. Min., Geol. u. Pal., 1909, p. 161), describing 

nontronite derived, from wollastonite, assigns it a different formula H
THE 'DECOMPOSITION OF KOCKS. 487

yielding a ferric hydroxide, limonite, as a final product of aqueous 

action. According to Weinschenk, mixtures of k'aolinite and norttemite are sometimes found, ia which the structure of the original 

gneiss is plainly to be discerned. That kaolinite is the chief residual 

product of feldspathic decay is the commonly accepted view, but 

some writers hold that it is not formed by ordinary weathering. 

According to H. Hosier,1 kaolinite is only produced by pneumatolytic action that is1 , by the operation of thermal waters and gaseous 

emanations. This theory, which applies to some localities, but not 

to all, has led to much controversy. P. H. Butler,2 studying the 

porcelain clays of Cornwall and Devon, ascribes their formation to 

the action of hot ascending waters, for he finds the degree of kaolinization to increase with depth, with fresher rocks near the surface. 

E. Wrist 3; regards the kaolin near Halle, Germany, as derived from 

feldspars by the action of humus acids. That kaolinization often 

takes place under moors, due to the carbonated waters that are there 

present, has been urged by various writers; for example by 0. Haehnel,4 

J. E. Barnitzke,5 F. Weiss,® E. Ehdell,7 and others. H. Stremme 8 

recognizes the almost self-evident fact that any of the suggested processes may be operative, weathering, pneumatolytie action, and 

kaolinization by moor waters, but ascribes their efficiency in all 

cases to the chemical activity of carbonic acid. Jointly with 

0. GageP Stremme describes one instance of kaolinization by the 

waters of a cold carbonated spring. V. Selle,10 who has studied the 

kaolin of Halle, which is derived from quartz porphyry, traces it to 

ordinary weathering, first sericite and then kaolinite being formed. 

Here the deposit is richest in kaolin near the surface. The abundant 

kaolin along the eastern side of the southern Appalachians is evidently due to the weathering of pegmatite.

In short, kaolin, like.many other substances, may be formed by 

any one of several processes, in all of which water, hot or cold, and 

carbonic acid take part. No one interpretation cari fit all its occurrences.

< Ncues. Jahrb.., Bell. Band 15r 1902r p. 231. Busier gives a bibliography relative to kaolinization, embracing 303 titles. See also 0. Stutzcr, Zeitschr. prakt. Geologic, 190o, p. 33$, who accepts Hosier's view, and J. 

M. van Bcminelen, Zeitschr. anorg. Chcmic, vol. GO, 1910,.p. 322. Van Bemmelen, ho wever, does not accept 

the theory exclusively but admits that weathering, may also produce kaolin. In a recent paper, Zeitschr. 

prakt. Geologic, 1908, p. 251, R6sler defends his views.

2 Mineralog. Mag., vol.. 15,1908, p. 128.

3 Zeitschr. prakt. Geologic, 1907, p. 19.

* Jour, prakt, Chemic, 2d ser., vol. 78,1908, p. 280..

6 Zeitschr..prakt. Geologic, 1909, p. 457.

«Idem, 1910, p. 353.

' Sprechsaal, Nos. 19, 20,1910.

8 Zeitschr. prakt. Geologic, 1908, pp. 122,443. Other recent papers on the origin of clays are by G. Linck 

Geol. Rundschau, vol. 4, p. 289,1913; H. Rics, Trans. Am. Ceramic Soc., vol. 13,1911, p. 15; H. O. Buckman, idem, vol. 13,1911, p. 33G; and I. Ginsburg, Ann. Tnst. Polytech. St. Petersburg, vol. 17,1912, p. 215. 

Ginsburg's paper is in Russian, with a German abstract, and a copious bibliography.

»Ccntralbl. Min., Gcol. u. Pal., 1909, p. 427.

10 Jour. Chem. Soc., vol. 96,-pt. 2, p. C3, abstract from Zeitschr. Naturwiss., vol. 79,1907, p. 321.
488 DATA OF GEOCHEMISTRY.

The other hydrous silicates of aluminum and iron, such as halloysite, 

cimolite, pyrophyllite, chloropal, etc., are of more or less uncertain 

origin. Probably different crystalline silicates yield different residues of this ill-defined class, and any or all of them may.exist in 

residuary clays.1 '.- -.

LATERITE AND BAUXITE.

In tropical and subtropical regions the processes of rock decay 

are often carried further than is usually the case within the temperate zones. The leaching is more complete, the silicates are more 

thoroughly decomposed, and the residues are richer in hydroxides. 

. In India, for example, large areas are covered by a red earth known 

as laterite, which in some cases is undoubtedly a derivative in place 

of preexisting rocks, such as granite, gneiss, basalt, or diorite. In 

other cases the laterite is detrital in character and far distant from 

its place of origin. The term has been vaguely used, and as employed by different writers it has meant very different .things. It 

has been applied to ferruginous clays, sediments, beds of iron ore, 

and products of volcanic action, and,its formation has been attributed to a variety of causes.2 W J McGee 3 compares laterite with 

the ferruginous clays and soils of the upper Mississippi,, and F. R. 

Mallet 4 regards the iron ores, associated with the basalts of Ulster 

as having a lateritic character. W. Maxwell,5 describing the red 

soils of the Hawaiian Islands, which are deriveo! from lavas by 

the action of volcanic acids, points out their similarity to laterite. 

T. H. Holland 6 suggests that lateritization may be due, in part at 

least, to the activity of bacilli or other micro-organisms which could 

live in a warm climate but not in colder regions. J. Walther 7 and 

S. Passarge 8 call attention to the relatively large proportion of nitric 

acid in rainfall during tropical thunderstorms, and regard it as a 

possible cause of lateritization. Brought to the surface of a decomposing rock, it might extract the iron as ferric nitrate, and that compound is either easily hydrolyzed or else precipitated by alkaline 

carbonates. In short, similar products may have been formed in 

several different ways, and identity of composition does not always

' On the constitution of the clay silicates see H. Le Chatelier, Zeitschr. physikal. Chemie, vol. 1, 1887, 

p. 396. See also J. W. Mellor, Trans. Ceramic Soc. (English) vol. 10, 1910-11, p. 94, and F. W. Clarke, 

Bull. U. S. Geol. Survey No. 588,1914. ,

2 See R. D. Oldham, Manual of the geology of India, 2d ed., 1893, pp. 348-370. P. Lake (Mem. Geol. 

Survey India, vol. 24, pt. 3,1890, pp. 17-46) gives a good summary of earlier views upon the origin of laterite. 

Another elaborate summary is presented by G. C. Du Bois, Min. pet Mitt., vol. 22, 1903, pp. 4-18. A 

good chapter on laterite, with a bibliography, is in Abhandl. K. preuss. geol. Landesanstalt, new se'f., 

Beft 62,1909.

3 Geol. Mag., 1880, p. 310. 

* Rec. Geol. Survey India, vol. 14,1881, p. 139.

6 Lavas and soils of the Hawaiian Islands, Honolulu, 1898. Maxwell gives many analyses of decomposition products derived from lava, both by volcanic action and by normal weathering, 

e Geol. Mag., 1903, p. 59.

' Verhandl. Gesell. Erdkundc, vol. 16,1889, p. 318. 

8 Rept. Sixth Internal. Geog. Gong., London, 1895, p. C71.
THE DECOMPOSITION OF ROCKS. 489

imply identity of origin. Whatever its derivation may be, whether 

from rocks in place or as a transported sediment, true laterite is 

essentially a mixture of ferric hydroxide, aluminum hydroxide, and 

free silica in varying proportions.- To laterite in situ this statement applies very closely; detrital laterite is usually contaminated 

by admixtures of clay. Just as in the formation of kaolin, the process of lateritization may be complete or partial; the typical product 

appears only when the alteration of the parent rock has gone on 

to the end. Then the silicates seem to be completely broken down, 

whereas in kaolinization a stable, hydrous silicate remains. In one 

case we have silica plus free hydroxides, in the other silica plus kaolin. 

According to E. C. J. Mohr * lateritic decomposition (and the formation of bauxite) occurs principally where there are plagioclase feldspars. Alkali feldspars yield mainly kaolin. In this view J. B. 

Harrison,2 who has studied the laterites of British Guiana, concurs. 

In India laterite may be derived from various rocks, and in some 

cases its source has been in beds of volcanic ash. According to P. 

Lake,3 the laterite of Malabar is produced in situ from gneiss. M. 

Bauer 4 has described "granite laterite' 1 and "diorite laterite" from 

the Seychelle Islands; in Surinam, according to G. C. Du Bois,5 its 

usual parent is diabase; in the Hawaiian Islands it is formed from 

recent lavas.6 There are many analyses of laterite, some of them 

relating to samples of known origin, others to detrital material. 

For example, Bauer gives these two analyses by K. Busz of laterite 

from the Seychelles:

' Bull. Dept. Agr., Indcs N<5erlandaises, No. 28,1909. An earlier paper on laterite is in No. 17, 1908.

2 Gcol. Mag., 1910, pp. 439, 488, 553. On laterite from diabase, idem, 1911, p. 120.

» Mem. GeoJ. Survey India, vol. 24, pt. 3,1890, p. 17. M. Maclaren (Geol. Mag., 1906, p. 536) regards tho 

Indian laterite as formed, not directly in situ, but by replacement of soil or decomposed rock by deposits 

from mineralized solutions. The latter he attributes to subterranean decomposition of silicates by carbonated waters. A similar theory is advanced by J. M. Campbell (Trans. Inst. Min. and Met., vol. 19, 

1910, p. 432), who regards the hydroxides of laterite as deposited from ascending, mineralized waters. A 

later paper by Campbell is in Mining Mag., vol. 17,1917, pp. 67,120,171,220. Other recent papers on laterite 

are by J. R. Kilroe (Geol. Mag., 1908, p. 534), J. Chautard (Compt. rend. Soc. incl. min., April, 1908, p. 119), 

Chautard and P. Lemoine (Bull. Soc. ind. min., 4th ser., vol. 9,1908, p. 305, and Compt. Rend., vol. 146, 

1908, p. 239). F. P. Mennell (Geol. Mag., 1909, p. 350) has described laterite in Rhodesia. J. M. Van Bemmelen (Zeitschr. anorg.' Chemie, vol. 66,1910,"p. 322) discusses laterite and kaolin. See also R. Lenz, Inaug. 

Diss., Freiburg, 1908, and W. Meigen, Geol. Rundschau, vol. 2, p. 197, 1911. On the laterite of French 

Guinea see A. Lacroix, Nouv. Arch. Mus. Hist. Nat. (Paris), 5th ser., vol. 15,1913, p. 255, reviewed by L. L. 

Fermor, in Geol. Mag., 1915, pp. 28, 77,123. On Indian laterite, R. C. Burton, Rec. Geol. Survey India, 

vol. 48,1917, p. 204. ..'.'.'

4 Neues Jahrb., 1898, Band 2, p. 192. Also a later paper by Bauer in Neues Jahrb., Festband, 1907, p. 33.

6 Min. pet. Mitt., vol. 22,1903, p. 1. Du Bois gives several analyses of laterite.

«W. Maxwell, Lavas and soils of the Hawaiian Islands. C. Klement (Min. pet. Mitt., vol. 8,1886, p. 26) 

gives two analyses of laterite from the Congo River in West Africa. Other important analyses are by 

H. Arsandaux (Compt. Rend., vol. 149, 1909, p. 682, and vol. 150, 1910, p. 1698) and A. Atterberg (Centralbl. Min., Geol. u. Pal., 1909, p. 361). In certain Indian laterites W. R. Dunstan (Rec. Geol. Survey 

India, vol. 37, pt. 2,1908, p. 213) found unusual amounts of Ti02, up to 13.76 per cent. On laterite in West 

Australia see E. S. Simpson, Geol. Mag., 1912, p. 393, and W. G. Woolnough, Geol. Mag., 191S, p. 385. On 

laterite in Mozambique, see A. Holmes, idem, 1914, p. 529.
490 DATA OF GEOCHEMISTRY.

Analyses of latevitc:

SiO*..... ............. -..-:. .................................

A1203 ........................................................

Fe20s.. ....................................................

R&..... ............. ....................-.........-...........:.

Granite laterite.

52.06

29.49

4.64

14.40

I 100. 58

; Dioritelati erite.

3.88

49.89

20.11

: 25. 98

99. 86

If from these mixtures we deduct the silica, as quartz, the remainder 

will approximate to the general formula RO3H3, which is that of 

gibbsite. The water, however,, is a little, too low, and a careful reduction: of the data leads to the supposition that the residual substance 

is a mixture of gibbsite, AIO3H3 ; diaspore, AlOjH, and limonite, 

Fe4H6(\. In short, laterite is identical in type with bauxite, and 

is merely an iron-rich variety of the latter. Between the aluminous 

bauxite, and the iron compound limonite all sorts of mixtures may 

occur.

From this point of view the analyses of Indian laterite published 

by H. and F. J.. Warth 1 are peculiarly instructive. A represents 

gibbsite,, B bauxite, and C, 'D,. E, and F laterite, found in situ.

Analyses of gibbsite, bauxite, and laterite.

SiO..........................

A1Z03 ......... ...............

FeA....... .................

MeO

CaO...........................

TJQ3 .. .......................

HaO... ............... ........

A

2.78

62.80

.44

.03

.20

.04

33. 74

ioo=. oa

B

0 Q3

67.88

4 flQ

.36

1 (M

26.47

100. 77

' C

9 Qn

54.80

13. 75

qc

 qo

26. 82

100.00

D

0

07

43. 83

26.61

.86

A 4£

23. 88'

100.00

E

10.52

91

35.38

34.27

:40

.10

19.00

100.00

F

0.90

26. 27

56.01

90

(U

1.59

14.39

100.00

The following analyses (G to J) represent detrital laterites: 

Analyses of detrital laterites.

Quartz. .......................................

Kaolinite. .....................................

fAl203 -. ........

Fe2O3 . .........

Balance, identical with bauxite< Q^Q ' ' ' - 

|TiO2 .. .........

'' G

6.67

28.77

15. 40

 41.50

; None.

.25

7.41

; 100. 00

H

4.53

50.26

11.86

28. 99

None.

.43

3.93

100. 00

I

39.53

17. 16.

 ». 58

.01

5. 34

; 100. 00

J

94 ^

9fl 99

47 39

Trace.

.38

.01

7.61

100. 00

i Geol. Mag., 1903, p. 154. Only a selection from among a large number of analyses can be given hero. 

See also n. Warth, Mineralog. Mag., vol. 13, 1902, p. 172, for a description of Indian gibbsite, and L. L. 

Former, Eec. Geol. Survey India, vol. 34,1906, p. 167, on gibbsite and manganese ores in laterite. Fermor 

has also discussed the nature of laterite in Geol. Mag., 1911, pp. 454,507,559.
THE DECOMPOSITION OF BOCKS. 491

Between bauxite and laterite there is no dividing line, and the one 

shades into the other. The detrital laterites differ from those in 

situ merely in having taken up sand and clay during their transportation from one point to another. The bauxite itself, if we restrict 

that term to the dominantly aluminous varieties, is probably a mixture of the two hydrates, corresponding to gibbsite and diaspore, the 

latter compound, however, like the gibbsite, being in an amorphous 

condition. Crystallized gibbsite or hydrargillite is comparatively 

rare.

Bauxite, like laterite, occurs under a variety of conditions, which 

suggest a dissimilarity of origin. Its formation has been explained 

in various ways, but no one theory seems to fit all cases. 1 The French 

bauxites are found mostly associated with Cretaceous rocks,2 and they 

have been interpreted by several writers as deposits from hot springs 

or other thermal waters.3 S. Meunier, for example, regards bauxite 

as precipitated alumina thrown down by the action of calcium carbonate upon solutions of aluminic salts. Hot waters, rising from considerable depths, are supposed to have dissolved alumina from the 

rocks and brought it into the region of limestones. The fact that 

certain French bauxites rest upon corroded limestones gives a plausibility to Meunier's suggestion. This mode of occurrence, however, is 

not general.

In several German localities bauxite is found, like laterite, as a 

direct residue from the decomposition of basalt.4 The bauxite in 

some cases shows the structure of the original rock. Auge* 5 observed 

bauxite at one locality in Auvergne resting on gneiss and partly overlain by basalt. In Ireland G. A. J. Cole6 has described bauxite 

which was apparently derived from rhyolite or rhyolitic ash, and one 

decomposing rhyolite was found to contain a considerable proportion 

of alumina soluble in hot sulphuric acid. Cole supposes that the 

lavas were first attacked by acid vapors and that the alumina so dissolved was precipitated by waters containing alkaline carbonates.

1 See T. L. Watson, Bull. Geol. Survey Georgia No. 11, 1904, for a good summary of the literature of 

bauxite, and a bibliography.

2SeeH. Coquand, Bull. Soc. g<k>l. France, 2d ser., vol. 28,1870, p. 98. Augd.idcra. 3d ser., vol. 10,1880, 

p. 345. F. Laur, Trans. Am.Inst.Min. Eng., vol.24,1894, p. 234. For a later paper by J.aur sec Corapt. 

Rend. Soc.ind. min., 1908, p. 430. On the composition of bauxite see H. Arsandaux, Compt. Rend.,vol. 

148,1909, pp. 937,1115; and also in Bull. Soc. min., vol. 36, p. 70,1913.

' See Coquand and Aug6, as just cited; also S. Meunier, Compt. Rend., vol. 96,18S3, p. 1707; Bull. Soc. 

geol. France, 3d ser., vol. 17, 188S, p. 64. Augd argues from an erroneous datum relative to supposed 

Ijauxiteformed by geysers in the Yellowstono National Park. F. Parmenticr (Compt. Rend., vol. 115, 

1892, p. 125) has called attention to the occurrence of alumina in mineral waters.

* See A. Strong, Zoitschr. Deutsch. geol. Cosell., vol. 39,1887, p. 621. A. Liebrich, Inaug. Diss., Zurich, 

1891. T. Petersen, Ber. XXVI Vers. Oberrhein. geol. Vereins, 1893, p. 38. J. Lang, Bcr. Deutsch. chem., 

Gesell.,vol. 17,1881, p. 2S92. R. Delkeskamp, Zeitschr.prakt. Geologic, 1904, p. 306. Kobrich,idem, 1905, 

p. 23. H. Miinster, Inaug. Diss., Giessen, 1905, on laterite-bauxite deposits in the Vogelsgebirge. On 

Hungarian bauxite,see J. von Szddoczky, Foldt. Ko'zl., vol.35,1905, p. 247, and R. Lachmann, Zeitschr. 

prakt. Geologic, 190S, p. 353. Sec also J. B. Harrison, Report on bauxite in British Guiana, Demerara, 

1917, an o.Ticial publication.

6 Los.cit.

0 Trans. Roy. Dublin Soc.,2d ser., vol. 0,1896, p. 105.
492 DATA - OF GEOCSEMISTEY. "."

?-

G. H.'Kinahan, 1 however, describing other Irish localities where the vbauxite is associated with iron ores, suggests that the mineral was 

formed by the leaching action of organic matter, derived from superincumbent peat, upon ferruginous clays. - -

In the United States the chief deposits of bauxite are found in 

Georgia, Alabama, and Arkansas. The Georgia-Alabama field has 

been principally described by J. W. Spencer, 2 H. McCalley,3 C. W. 

Hayes, 4 and T. L. Watson.5 Spencer regards the bauxite as a deposit 

from lagoons, and calls attention to its evidently common genesis 

with ores of manganese and iron. Under this interpretation, which 

has not been generally accepted, bauxite becomes the aluminous 

equivalent of bog iron ore. Hayes notes its association with gibbsite, -r 

halloysite, and kaolin, and attributes its formation to heated ascend- v 

ing waters, which have decomposed pyrite in the underlying shales. 

Aluminous solutions were thus brought to the surface, to be precipi- "* 

tated by carbonate of lime. A similar intervention of sulphates has 

been suggested by A. Liebrich6 and others. The occurrence of 

.bauxite in immediate association with alunogen on the upper Gila * 

River, in New Mexico, as reported by W. P. Blake,7 gives added 

emphasis to this suggestion. The alteration of rhyolite to a quartzalunite and a quartz-diaspore rock in the Rosita Hills, Colorado, "*" 

described l)y W. Cross,8 may also have some bearing upon the problem. As for the Georgia-Alabama bauxite, its composition, as shown 

by many analyses, approximates to that of gibbsite.9 The latter 

species, it may be observed, was prepared synthetically by A. De 

Schulten,10 by passing a current of carbon dioxide through a hot alka- ^ 

line solution of aluminum hydroxide. Distinct crystals of gibbsite 

were thus obtained.

1 Trans. Manchester Geol. Soc., vol. 22,1894, p. 458. In thesame volume, p. 524, analyses of Irish bauxites 

by W. Peile are given, and there is still another paper on the subject by G. ,G. Blackwell, p. 525. The - 

analysesshow large admixtures of titanic oxidein the bauxite.

2 Geol. Survey Georgia, The Palaeozoic group, 1893, p. 214. . ' v 

. 3 Geol. Survey Alabama, pt. 2,1897. . . ^

« Sixteenth Ann. Kept. U. S. Geol. Survey, pt. 3, 1895, p. 547. See also Trans. Am. Inst. Min. Eng., 

1894,p. 243. . . ' ' ;

& Bull. Geol. Survey Georgia No. 11,1904. In Bull. No. 18,1909, p. 430, 0. Veatch describes the bauxite 

of WiMnson County, Georgia.

6 Zeitschr. prakt. Geologic, 1897, p. 212. . .......

7 Trans. Am. Inst. Min. Eng., vol. 24,1894, p. 573.

8 Seventeenth Ann. Kept. U. S. Geol. Survey, pt. 2, 1896, p. 314. A quartz-alunite rock in California 

has been described by H. W. Turner, Am. Jour. Sci., 4th ser., vol. 5,1908, p. 424. The same mixture of , 

minerals is found in the mines of Goldfield, Nevada, according to F. L. Kansome, Econ. Geology, vol. 2, 

1907, p. 673. Ransome also reports intergrowths of alnnite and diaspore, .

9 See W. B. Phillips and D. Hancock, Jour. Am. Chem. Soc., vol. 20,1898, p. 209, Admixtures of kaolin, 

balloysite, and sand were noted. See also Watson, loc. cit., and A. E. Hunt, Trans. Am. In st.Min. , 

 Eng., vol. 24, 1894, p. 855. Titanic oxide is almost invariably present, in some cases reaching as high f 

as 9.80 per cent. It also appears in the foreign bauxites already mentioned, and.in the Italian bauxites 

described by C. Formenti, Gazz. chim. ital., vol. 32, pt. 1,1902, p. 453. On Italian bauxites see G. Aichino, 

La bauxite, Torino, 1902. Reprint from Rassegna mineraria, vol. 15.

"OBull. Soc. min., vol. 19,1896jp. 157. ....
THE DECOMPOSITION'OF KOCKS. 493

- The-bauxite of-Arkansas-has been studied-by J- F. Williams, 1 J. C. 

Branner,2 and C. W. Hayes. 3 According to all of these observers, it 

is found in Tertiary areas near eruptive syenites, and .there are no 

limestones in its neighborhood. Hayes describes two varieties of the 

bauxite; one, granitic in character, shows the structure of the syenite from which it was probably derived; the other form is pisolitic 

and may be a secondary generation. At some points, according to 

Branner, the bauxite contains so much iron that attempts have been 

made to work it as an iron ore. The granitic bauxite seems to represent a decomposition of the syenite in place; the pisolitic variety was 

perhaps precipitated from solution. All three authorities agree in 

tracing the origin of the bauxite to the action of waters, which Hayes 

thinks were strongly saline or alkaline, upon the heated syenites, 

but they differ as regards the details of the process. One of the 

Arkansas deposits is near Fourche Mountain, and it is interesting to 

recall the fact that that is a locality for elseolite syenite. Both 

gibbsite and diaspore are known as decomposition products of elaeolite and sodalite, 4 and it is conceivable that the two last-named species may have been the parents of the bauxite here. Like the Georgia 

bauxite, the Arkansas mineral approximates to gibbsite in composition.5 It also contains notable amounts of titanium.

Although many writers have regarded bauxite as a distinct mineral 

species, having the empirical formula A1203 .2H20, few samples of 

it have exactly that composition. It is usually intermediate between 

diaspore, A1203 .H20, and gibbsite, A1203 .3H20; but is sometimes 

near one and sometimes near the other. It seems, in fact, to be a 

mixture of the two hydrates, but in an amorphous condition.6 When 

solutions of sodium aluminate are decomposed by carbon dioxide, 

only the trihydrate is thrown down, at least so far as crystalline 

products have been observed.7 The ordinary, precipitated, gelatinous hydroxide has the same composition, according to E. T. 

Alien; 8 but at 100° it loses water and becomes a dihydrate. The 

latter, in moist air, regains water readily an order of change which 

renders its occurrence on a large scale as a natural mineral highly

1 Ann. Kept. Arkansas Geol. Survey, vol. 2,1890, p. 124.

2 Jour. Geology, vol. 5, 1897, p. 263. This review contains a bibliography of bauxite, and references to 

earlier papers by Branner.

8 Twenty-first Ann. Kept. U. S. Geol. Survey, pt. 3,1901, p. 435. See also W. J. Mead, Econ. Geology, 

vol. 10,1915, p. 29.

< See S. J. Thugutt, Neues Jahrb., Beil. Band 9,1895, p. 609. Also W. C. Brogger, Zeitschr. Kryst. Min., 

vol. 16,1890, p. 50.

6 On the hydroxides in Arkansas bauxite see D. C. Wysor, Econ. Geology, vol. 11,1916, p. 42.

« On the hydration of bauxite, see also H. Lienau, Chem. "Zeitung, 1905, p. 1280; and T. H. Holland, 

Rec. Geol. Survey India, vol. 32,1905, p. 175. Holland gives analyses, and in one of them the Ti08 reaches 

12.21 per cent.

i See De Schulten, already cited. Also F. Russ, Zeitschr. anorg. Chemie, vol. 41,1904, p. 216, for recent 

experiments and a summary of the work done by earlier investigators.

8 Chcm. News, vol. 82, 1900, p. 75. On this subject there is a voluminous literature, and the published 

data are very discordant".
494 DATA OF GEOCHEMISTRY.

improbable. Even if a dihydrate were formed, it would speedily be 

altered into something more nearly resembling gibbsite. In the colloidal form, the trihydrate often contains large quantities of entangled 

water, a fact which accounts for many discordant observations. 

According to J. M. van Bemmelen 1 this form can pass over into the 

crystalline modification and the latter in turn may become amorphous. 

The colloidal variety dissolves to a greater or less extent in water, 

but is readily precipitated from its very unstable solutions. Precipitated alumina often contains appreciable quantities of carbonates, 

but whether they are chemically combined or not is very uncertain. 

The basic carbonates of aluminum described by various authors are 

substances of doubtful character, and it is therefore not desirable to 

invoke their aid in the interpretation of geological phenomena. This 

statement, however, needs qualification. One basic carbonate of aluminum and sodium, the rare mineral dawsonite, is known to exist, but 

its genesis is undetermined. There is also the rare dundasite, a carbonate of aluminum and lead. Although rare as a recognizable substance, dawsonite may be common as a diffused ingredient of soils; but 

this is only a possibility. There is no evidence upon which to base the 

supposition. Free alumina, or its hydrate, is found in soils, especially in the Tropics. T. Schlosing,2 on comparing French soils with 

soils from Madagascar, found the latter to contain much free alumina, while in France there appeared to be chiefly, if not exclusively, 

silicates. Similar observations were made by J. M. van Bemmelen 3 

on volcanic soils from Java and Sumatra, in which free hydroxides 

of iron and aluminum are abundant; and W. Maxwell's study of 

Hawaiian soils 4 leads to the same conclusions. In these occurrences 

the bauxite or laterite substance is diffused instead of being concentrated. It is therefore less easily recognized, but its nature is the 

same as if it were assembled or segregated in distinct beds.

Taking all of the evidence into account, it seems clear that bauxite 

may be formed by more than one process. It occurs in place, like 

laterite, as a residue from the decomposition of rocks; it is found 

also, apparently, as a precipitate, and sometimes, like any other product of disintegration, it is in beds which represent transported material. In the last instance it is contaminated by mixture with sand 

and clay. Even in its residual or primary occurrence, its impurii Rec. trav. chim., vol. 7,1888, p. 75. Zeitschr. anorg. Chemie, vol. 18,1898, p. 132. On the colloid character of bauxite see E. Dittler and C. Doelter, Centralbl. Min., Geol. u. Pal., 1912, p. 104; and A. Luz, Kolloid 

Zeitschr., vol. 14, 1914, p. 81. Also, with regard to Croatian bauxites, M. Kispatic, Neues Jahrb., Beil. 

Band 34,1912, p. 513; and F. Tucan. idem, p. 401, and Centralbl. Min., Geol. u. Pal., 1913, pp. 65, 495.

2 Compt. Rend., vol. 132, 1001, p. 1203. According to K. Glinka (Zeitschr. Kryst. Min., vol. 32, 1900, 

p. 79), kaolin commonly contains admixtures of aluminum hydroxide, sometimes as diaspore, sometimes 

apparently bauxite. See also M. G. Edwards (Econ. Geology, vol. 9,1914, p. 112) on aluminum hydrates, 

in clays.

3 Zeitschr. anorj;. Chernie, vol. 42,1904, p. 205.

4 Lavas an3 s:>ils of the Hawaiian -Islands.
THE DECOMPOSITION OF'BOCKS. 495

ties are significant, for they show a concentration of the insoluble 

portions of the original rock. The titanium, for example, which was 

first observed in bauxite by H. Sainte-Claire Deville,1 is such a product of concentration; and it is found not only in bauxite but in 

nearly all residual clays. It is possibly present in some cases as the 

hydrous aluminum titanate, xanthitane, a mineral which is known 

as an alteration product of sphene.

The processes by which aluminous silicates are transformed into 

hydroxides have not been determined with certainty. We have only 

probabilities to guide us. It is most likely that in many cases the 

formation of acid solutions by oxidation of pyrite is the first step 

in the alteration; they dissolve alumina from the rocks to yield it 

up again upon mixture with alkaline solutions or solutions of calcium carbonate. In the latter case gypsum would also be formed 

and then leached away. The precipitation might occur in place, 

almost contemporaneously with the formation of the aluminous solutions, or the dissolved matter could be carried some distance before 

deposition. Since colloidal alumina is soluble in water, it might be 

transported to a considerable distance before coagulation occurred. 

The solution of alumina from the rock-forming silicates would of 

course be accompanied by a liberation of silica in a colloidal or finely 

divided form, which could dissolve readily in the alkaline matter of 

the ground waters, and so be removed. In volcanic regions, of 

course, as in Java, Sumatra, and Hawaii, the acid emanations from 

volcanoes doubtless play an important part in the decomposition of 

the silicates and the solution of alumina.

The agency of thermal and atmospheric waters, separately or conjointly, must also be considered with reference to the formation of 

bauxite. E. Kaiser,2 studying the alteration of German basalts, 

supposes that carbonated waters first transform the aluminous silicates into hydrous compounds, from which, by alkaline solutions, the 

alumina is thrown down; that is, the process consists of two stages, 

an intermediate hydrated silicate being first formed. Kaolinite is 

such a silicate, but it is insoluble, and the change ends with its formation. Possibly halloysite, which has the composition of kaolinite 

plus water, but which is decomposed by acids, is such an intermediate 

compound. The association of halloysite with the Georgia bauxite 

is suggestive of this possibility; but alternatives, such as the formation of zeolites, must also be taken into account. Any relatively

i Annales chim. phys., 3d ser., vol. 01,1861, p. 309. Deville also found vanadium in bauxite. See also 

the references to analyses of bauxite previously cited. The almost universal distribution of titanium in 

clays seems to have been first noted by E. Biley, Jour. Chcm. Soc., vol. 15,1862, p. 311, and vol. 16,18G3, 

p. 387. See also F. P. Dunnington, Am. Jour. Sci., 3d scr., vol.42,1891, p. 491.

8 Zeitschr. Deutscli. geol. Gosell., vol. 50, Honalsb., 190-1, p. 17.
496 DATA OF GEOCHEMISTRY.

soluble or unstable silicate of aluminum ] would fulfill the conditions 

required by Kaiser's hypothesis. The latter has value only as a 

suggestion, and it remains to be seen whether it is possible to trace 

the transformation of an igneous rock into bauxite through all of 

its stages. So far, that has not been done.

By dehydration, bauxite passes into emery. Emery, therefore, 

may sometimes be regarded as the metamorphic equivalent of bauxite.2

ABSORPTION.

In any study of the phenomena attending rock decomposition it is 

important to note that the leached products can regain some of the 

substances which they have lost. Clays, soils, and other finely 

divided mineral matter can extract acids, bases, and salts from percolating solutions and in doing so they act selectively. As a rule a 

soil takes up potash more readily than lime, magnesia, or soda, and 

retains it tenaciously. This absorption or adsorption of potassium 

compounds was long ago observed by J. T. Way,3 and the phenomenon has since been studied by many observers. R. Warington 4 

found that hydroxides of iron and aluminum, particularly the former, 

were especially active as absorbents, and most so in the presence of 

calcium carbonate. That is, calcium carbonate converted other 

alkaline salts into carbonates, which were more easily absorbed. J. 

Lemberg's papers 5 on the alteration of silicates are rich in data 

illustrating the reactions which occur during absorption. The cases 

studied by Lemberg are of the nature of double decompositions, in 

which a silicate loses one base to a solution only to take up another. 

The recent investigations by M. Dittrich 6 relate to changes of the 

same order. Saline solutions were made to act upon decomposed 

rocks and their changes in composition were observed.

Double decomposition, however, is not the only process to be considered in this connection. Warington's experiments point directly

' It is possible that some of the supposed hydrous silicates of aluminum which have been described are 

merely mixtures of colloidal silica and colloidal alumina. This is claimed by H. Stremme, Centralbl. 

Min., Geol. u. Pal., 1908, p. 661,1911, p. 197, and 1914, p. 80, in the cases of allophane, halloysite, and montmorillonite. Their definiteness as compounds, on the other hand, is affirmed by S. J. Thugutt, idem, 1911, 

p. 97, and 1912, p. 35. See also R. Cans; idem, 1913, p. 699, and 1914, p. 365. Several of these mineralshave 

been studied physically by E. Lb'wenstein, Zeitschr. anorg. Chemie, vol. 63,1909, p. 69, whose experiments 

are favorable to their integrity.

a See A. Liebrieh, Zeitschr. prakt. Geologic, 1895, p. 275. For a different composition of emery, see the 

section on corundum in Chapter X of this work.

» Jour. Roy. Agr. Soc. England, vol. 11,1850, p. 313; vol. 13,1852, p. 123.

«Jour. Chem. Soc., vol. 21,1868, p. 1.

* See especially the memoir in Zeitschr. Deutsch. geol. Gesel 1., vol. 28,1876, p. 519.

e Mitth. Grossh.-bad. geol. Landesanstalt, vol. 4,1903,p. 339; Zeitschr. anorg. Chemie, vol.47,1905, p. 151. 

(The two papers cover the same ground in part, but are not absolutely identical. A later paper by Dittrich', 

is in Mitth. Grossh.-bad. geol. Landesanstalt, vol. 5,1907, p. 1. See also J. Dumont, Compt. Rend., vol. 142, 

1906, p. 345, on the decomposition of potassium carbonate by clay,etc.,and O. Schreiner and G. H. Failyer, 

Bull. Bur. Soils, No. 32, U. S. Dept. Agr., 1906, on the absorption of phosphoric'acid and potash by soils. 

Bull. No. 52,1908, of the same bureau, by H. E. Patten and W. H. Waggaman, is a general discussion of 

absorption by soils, with many references to literature. See also E. G. Parker, Jour. Agric. Research, 

vol. 1.1913, p. 179.
THE DECOMPOSITION OF BOOKS. 497

to an absorption by colloids, namely, the colloidal hydroxides of iron 

and alumina. According to J. M. van Bemmelen,1 those "hydrogels," 

as they are called, together with similar hydrogels of manganese 

and copper oxides, show a marked absorptive power for salts of the 

alkalies and alkaline earths. There are also colloidal complexes of 

ferric and aluminic silicates, and of humus, which act in the same way. 

These substances act, first, as absorbents, in some manner which is not 

clearly understood; and the salts which they take up can react later 

with various saline solutions by double decomposition. When the 

colloids pass over into crystalline substances, they lose in great measure their absorptive capacity. It has also been shown by Van Bemmelen 2 that plastic clays have the greatest efficiency as absorbents of 

water, nonplastic clays being inferior in this respect. It is now generally believed that the plasticity of a clay is due to the colloid substances which it happens to contain. This supposition was clearly 

stated by T. Schlosing 3 as long ago as 1888, and advocated later by 

P. Rohland.4 It has recently been developed more fully by A. S. 

Cushman,5 whose experiments upon the binding power of road-making 

materials are apparently conclusive.6

SAND.

The complete disintegration of a rock is commonly followed by a 

removal of the fragmentary material from its original site. The 

transported products are much more abundant than the sedentary. 

This transportation may be effected in various ways by flowing 

tstreams, by glacial ice, or by winds and it is accompanied to a cer 

ain extent by a separation of the rock residues, into substances of 

different kinds. A stream deposits its load first as coarse gravel, 

then as sand, and finally, often with extreme slowness, as silt or clay. 

The gravel consists merely of fragments, more or less rounded, of 

the-original rock or of its larger inclusions. The sand contains finer 

particles of undecomposed minerals, with quartz usually predominating. The silt is composecl largely of decomposition products such 

as kaolinite, hydroxides of iron or aluminum, and the like. These 

substances shade into one another, and their exact nature in any

> Zeitschr. anorg. Chernie, vol. 23,1900, p. 321. See especially pp. 338 and 30-1. An earlier paper by Van 

Beinmelen in Landw. Versuchs-Station en (Berlin), vol. 21, p. 135, should alsobenoted. J. E. Harris, 

Jour. Physical Them., vol. 18, p. 355,1914) has shown that soils and kaolin exert a selective influence in 

the absorption of salts; the bases being retained and the acids set free.

2 Zeitschr. anorg. Chemie, vol. 42,1904, p. 314.

3 Chimieagricole,in Fromy's Encyclope'die chimique, p. 67.

4 Zeitschr. anorg. Chemie, vol. 41,1904, p. 325.

6 Bulls. No. 85,1904, and No. 92,1905, Bur. Chemistry, U. S. Dept. Agr.,and Trans. Am. Ceramic Soc. 

vol. 6,1904. Cushman cites several other authorities than those mentioned here.

e See also F. E. Grout, Jour. Am. Chem. Soc., vol. 27,1905, p. 1037. Grout admits that colloids may 

assist in producing plasticity but thinksthat "molecular attraction" is a more important cause. Apaper 

by R. ioicas on the physical properties of clays appeared in Centralbl. Min., Geol. u. Pal., 1906, p. 33. A 

long paper, rich in reference to literature, by N. B. Davis, is in Trans. Am. Inst. Min. Eng., vol. 51,1917, 

p. 451. Davis attributes plasticity in clays to colloids. Bull. U. S. Geol. Survey No. 388, by H. E. Ashley, 

is a good treatise on colloids in clays, with a long bibliography on the subject. Tech. Paper, Bur. Standards, No. 23,1913, is another treatise by Ashley. 

113750° 19 Bull. G95 32
498 DATA -OF GEOCHEMISTRY.

specific case" will depend- upon the- thoroughness with which the primary decomposition was effected and upon mechanical factors such 

as the velocity of the stream.

The term "sand" is vaguely employed to denote very different 

substances. Volcanic sand, for example, is .finely divided lava or 

lava spray; coral or shell sand is made up of broken corals and 

shells, and so on. Even if we restrict the use of the word, for present 

purposes, to the granular products of rock decomposition we shall 

find that we have- many dissimilar, bodies to deal with. Quartz and 

feldspar are the commonest minerals in the rocks; henee quartz and 

feldspar fragments are the chief constituents of river sands. But 

the feldspars are largely decomposed, and therefore the sands, represent most frequently a concentration of the more stable quartz. 

Sands also contain the other rock-forming minerals, and these may be 

either disseminated throughout the larger deposits or segregated, behind bars or in hollows by the action of. gravity. The- black sandsof many well-known localities represent concentrations of heavy and 

slightly alterable minerals, such as magnetite, ilmenite, ehromite, etc. 

The gem gravels of Ceylon, the monazite sands of North Carolina 

and Brazil, and similar segregations of tinstone all serve as illustrations of the way in which the heavier minerals of an eroded region 

may be concentrated at favorable points. The accumulations of gold, 

platinum, or iridosmine in placer deposits are other examples of this 

mechanical sorting. It is merely a separation of heavy from light 

minerals;, the stable from the unstable, and the coarse from the fine.

There have been many examinations of sands from a mineralogical 

standpoint, and the fact that they contain a large number of mineral 

species is well established. The Bagshot sands near London contain,. 

according to A. B. Dick,1 about 75 per cent of quartz, 20 of feldspar, 

and small but determinable proportions of magnetic grains, zircon, 

rutile, and tourmaline. In river sands from the Mesvrin, near Autun, 

France, A. Michel-Levy 2 found magnetite, zircon, olivine,, garnet, 

sphene, ehromite, tourmaline, and corundum. J. Thoulet 3 examined 

desert sand from the Algerian Sahara which consisted of 89.46 per 

cent of quartz and 9.47 of feldspar, with minute quantities of magnetite, ehromite, garnet, oKvine, amphibolte, pyroxenes, calcium, carbonate, sodium and potassium chlorides, and clay. In a glacial sand 

from the Tyrol, H. Wichmann * discovered quartz, orthoclase, micas, 

chlorite, epidote, hornblende, aetinoEte,. garnet, zircon, rutile, tourmaline,. hematite, and altered pyrite. J. A. Phillips 5 found the red

1 Geology of London, vol. 1,, 1889, p. 523; Nature, vol.. 38, 1887, p.. 91.

» Idem,, vol.. 4, 1881, p. 262.

< Mm. pe*. Mitt. , vol. 7, 1886r p-. 452. The list of- minerals found by W. M. Hatchings (GeoL Mag." ,-1894, 

p. 300) in English lake sediments is very similar to this. - 

* Quart: Jour. Geol. Soc., vol. 38, 1882, p. 110.
THE DECOMPOSITION OP ROCKS. 499

sands of the Arabian Desert to consist essentially of quartz grains 

coated with oxide of iron. After washing with hydrochloric acid the 

grains contained 98.53 per cent of silica. Probably the most elaborate investigation of this general kind is that by J. W. Retgers * on 

"* the dune sands of Holland. In these the principal minerals are quartz, 

, garnet, augite, hornblende, tourmaline, epidote, staurolite, rutilo, 

; zircon, magnetite, ilmenite, orthoclase, calcite, and apatite. Subordinate species are plagioclase, microcline, iolite, titanite, sillimanite, 

olivine, kyanite, corundum, and spinel. The quartz, however, formed 

90 to 95 per cent of the mixture. A beach sand from Pensacola, 

Fla., analyzed by G. Steiger in the laboratory of the United States 

r Geological Survey, contained 99.65 per cent of Si02 . Many sea and 

river sands consist of nearly pure quartz, pure enough to be used in 

glass making. The following analyses, by W. Mackie, 2 represent 

sands of diverse origin from various points in Scotland.

> Analyses of sands. 

A, B. Glacial sands. 

C. Average of five river sands. 

»> D. Sea sand. .

E. Sea sand derived from subsilicie igneous rocks. 

F. Blown sand.

Si02 .........................

^ irAI 2 n~3- ------ ----- -- 

-fcFeA.......... ...... .........

FeO

s MnO. ........................

CaO........... ...... ..........

MgO.........................

K20... ...... .................

Na/)..........................

p ran u5 ...........................

Ignition. .....................

A

77.78

9.95

2.55

.21

.71

.17

2.50

1.82

2.74

98.43

B

90.74

5.16

1.14

.08

Trace.

.69

Trace.

1.19

.26

1.30

100. 56

C

82.13

9.04

2.94

1.28

.53

1.93

.95

.20

1.01 -\

100.01

D

89.99

7.36

.72

.13

Trace.

.46

Trace.

.84

.33

.60

100. 43

E

55.03

14.12

10.15

6.88

6.38

1.66

.87

4.55

99.64

F

91.39

5 44

.89

.16

Trnop

Trace.

Tropp

1.19

.70

.65

100. 42

SILT.

Between sand and silt the difference is partly one of kind and 

partly one of degree. Silt consists of the finer particles of rock substance, which, by virtue of their lightness, are carried farthest by

- streams. This difference is mechanical. On the chemical side sand 

j and silt differ in composition, but not radically. In sand quartz is

^ i Neues Jahrb., 1896, vol. l, p. 16; Kec. trav. chim., vol. 11,1S92, p. 169.

" Trails. Edinburgh Geol. Soc., vol., 1901, p. 60. On the mineralogical examination, of sands see also 

C. H. Warren, Tech. Quart,, vol. 19, 1906, p. 317. For analyses of American glass sands sec Bull.

- i> U. S. Geol. Survey No. 315,1907, pp. 376, 382. A sand rich in fluorite is found at St. Ives Bay, Cornwall. 

See T. Crook and G. M. Davies, Geol. Mag., 1909, p. 120. On the composition of soil particles see G. H. 

. Failyeir, I. G. Smith, and H. R. Wade, Bull. Bur. Soils, No. 54, U. S. Dept. Agr., 1908. On criteria for 

the recognition of different types of sand grains see W. H. Sherzer, Bull. Geol. Soc. America, vol. 21,1910, 

p. 625. On minerals in Ohio sands see D. D. Condit, Jour. Geology, vol. 20, p. 153, 1912, On Scottish 

sandsseo T. 0. Bosworth, Geol. Mag., 1912, p. 515.
500 DATA OF GEOCHEMISTRY.

the principal mineral; in silt the hydroxides and hydrous silicates 

predominate. Neither product is quite free from the other, but the 

distinction holds good in the main. The separation of quartz from 

clay is rarely quite complete, but is often approximately so.

Analyses of river silt or mud are not very numerous, nor are they 

always comparable. Some samples were analyzed after drying at 

100°; others were air dried. Furthermore, silts represent blended 

material, gathered by a river from various sources and derived from 

very dissimilar rocks. Mississippi silt, for instance, if collected near 

New Orleans, will be made up of contributions from various tributaries of the river, and these may be quite unlike. A region rich in 

femic rocks will yield sediments rich in iron, while an area of granite 

will give aluminous residues. Silts, therefore, are by no means uniform in character, although they have a general family resemblance. 

The following analyses are enough to show the more obvious differences and similarities:

Analyses of silts.

A. Rhine silt, from the delta in the Lake of Constance. Analysis by G. Bischof, Lehrbuch der 

chcmischen und physikalischen Geologic, 2d ed., vol. 1, p. 498. Bischof gives other data also concerning 

Rhine deposits.

B. Danube silt, at Vienna. Analysis by Bisehof, op. cit., 512.

C. Vistula silt, at Culm. Analysis by Bischof, op. cit., p. 515.

D. Nile mud. Analysis by C. v. John, Verhandl. K.-k. geol. Reichsanstalt, 1S96, p. 259. See also 

analyses cited by G. Bischof, op. cit., pp. 518-521; and others citedlby L. Horncr, in two memoirs, Philos. 

Mag., 4th ser., vol. 9, 1855, p. 409; Philos. Trans., vol. 148, 1859, p. 61. For modern analyses of silt from 

the Danube and its tributaries see J. F. Wolfbauer, Monatsh. Chemie, vol. 4,18S4, p. 417, and A. Schwager, 

Geogncst. Jahreshefte, 1893, p. 87. F. Schucht (Jahrb. K. prcuss. geol. Landesanstalt, vol. 25, p. 442) 

cites analyses of Elbe silt by H. Siissenguth. 

SlOn......... ........ .........................

Fe2 03 ---- - ....................................

MnO!...... ........ ...........................

MgO. .........................................

CaO..........................................

Na 6

CaCOg. .......................................

MgCOg....... ........ .........................

so, 3

JJ2Q_|_

Organic matter. ................................

Loss. ..........................................

A

50.14

4.77

2.69

.35

.34

.77

.55

.54

30.76

5.20

| .99

1.66

100. 00

B

45. 02

7.83

9.16

.44

.32

/9\

24.08

' 6.32

} 4.58

&2. 25

100. 00

C

4Q fi7

11.98

H 7Q

97

.88

1 9Q

fiQ

93 91

99.72

D

45. 10

15. 95

no OK

2.64

4.85

1.95

.85

.34

6.70

08.84

100. 47

Loss on ignition. 6 Probably including alkalies.

The higher proportion of calcium carbonate in the silts of,the 

upper Rhine and Danube is probably due to glacial mud produced 

by the grinding of limestones.
THE DECOMPOSITION OF ROCKS. 501

A much more complete and significant analysis of silt is that made 

by G. Steiger 1 in the laboratory of the Survey. A composite of 235 

samples, collected by E. W. Shaw in the delta of the Mississippi, was 

analyzed, giving the composition of the average contribution of the 

silt by the river to the Gulf of Mexico. The figures are as follows:

Analysis of Mississippi silt.

SiOa ...

A1203 ..

Fe2 03 - 

FeO... 

MgO... 

CaO... 

Na20.. 

K26... 

H20-. 

E2 0+. 

Ti02 ... 

Zr02 ... 

C02 ... 

PA-. 

S03 ... 

Cl..... 

F.....

69.96

10.52

3.47

1.41

2.17

1.51

2.30

3.78

1.96

.59

.05

1.40

.18 

.03

qr»

.07

S. ......................

rV H

Va0 8 ...................

NiO..... ................

MnO.. ...................

BaO........ ..............

SrO.. ......... ..........

CuO.. ..................

ZnO....................

As205 ..................

PbO...................

Organic matter. . .........

T(pc:q O

..... 0.07

..... .01

..... .02

..... .017

..... .06

..... .08

..... Trace.

..... .0043

..... .0010

...... .0004

..... .0002

...... .66

100. 6229 

...... .12

100. 5029

The amount of sediment carried in suspension by rivers to the sea 

is something enormous. The quantity delivered annually by the 

Mississippi to the Gulf of Mexico is estimated by A. A. Humphreys 

and H. L. Abbot 2 at approximately 812,500,000,000 pounds, or 

about 370,000,000 metric tons. The Nile, according to A. Chelu,3 

carries into the Mediterranean 51,428,500 metric tons a year. These 

quantities, vast as they are and sustained by similar estimates for 

many other'streams, represent only a part of the transported sediments. The products of rock decomposition are distributed along 

the entire course of a river, and what proportion is delivered to the 

ocean no one can say. The fraction can not be very large. Upon 

reaching salt water, however, the silt is quickly deposited, and only 

a small part of it is carried far out to sea. 4 Salts in solution accelerate 

the deposition of sediments, and so, too, do acids and alkalies. In 

general, this precipitation is effected by electrolytes, but the explana1 Jour. Washington Acad. Sci., vol. 4,1914, p. 59. A less completeanalysisbyC.il. Stone is reported in 

Science, vol.32,1906, p. 364.

2 Report on physics and hydraulics of Mississippi River, 1876, p. 148. R. B. Dole and H. Stabler OU". S. 

Geol. Survey Water-Supply Paper No. 234, p. 83,1909) estimate the total sediment carried to tidewater 

annually by the rivers of the United States as 513,000,000 tons of 2,000 pounds.

a Le Nil, le Soudan, 1'Egypte, 1891, p. 177.

* For a table giving the amount of suspended sediment in sea water at various points, see J. Murray 

and R.Irvine, Proc. Roy. Soc. Edinburgh, vol. 18,1890-91, p. 229. The Atlantic, for example, in latitude 

51° 20' N., longitude 31° W., carries 0.0052 gram of sediment in 14 liters, or 1,604 tons per cubic mile. In 

the Firth of Forth the quantity rises to 0.0259 gram, and in the Red Sea it falls to 0.0006.
502 - DATA OF GEOCHEMISTRY.

r

tion of the phenomenon is still obscure.1 Colloid substances also > 

promote sedimentation, a fact which has many practical applications. 

The clearing of coffee by white of egg or the fining of sirups by blood ' 

or gelatin is a phenomenon of the most familiar kind. W. Spring 2 

has shown that the organic matter of natural waters is incompatible *" 

with iron, the two substances separating out as a flocculent precipitate. One part of colloidal ferric oxide will remove ten parts of ^ 

humus from solution. The use of alum or iron salts in large filtration 

plants is an application of this principle. These salts hydrolyse, 

forming partly colloidal substances. The organic matter or humus 

of natural waters is itself colloidal. The two form a flocculen.t pre- *<\ 

cipitate which quickly subsides and carries down with it, mechanically . 

inclosed, even the finest sediments. The remarkable clearness of v

 r

swamp waters is perhaps due to the flocculation of their organic matter and the consequent precipitation of all suspended particles. Sedimentation, in short, is a complex phenomenon, and several distinct 

agencies Lssist in bringing it about.

 4

GLACIAL AND RESIDUAL CLAYS.

/

Between the silt formed by the decay of rocks and that produced . 

by glaciers there is a radical, distinction. The one is termed by 

T. C. Chamberlin and R. D. Salisbury 3 rock rot; the other is rock 

flour. One has been produced by a thorough leaching of the rocks 

under atmospheric agencies; but glacial mud is composed of material * . 

which was ground to powder under conditions that protected it in ^ 

some measure from the oxygen, and carbonic acid of the air. The 

latter, therefore, has retained a larger proportion of soluble matter 

than the former. These differences appear in the following analyses, f 

made by Riggs in the laboratory of the United States Geological 

Survey, and cited by Chamber lin and Salisbury in the memoir y-" 

mentioned, above. With them I give two analyses by W. Mackie 4 

of boulder clay from Scottish localities. r

iSeeC.Schlosing, Compt. Rend.,"vol.70,1870,p.l345; W. H. Brewer, Am. Jour. Sci.,3dser., vol. 29,' 

1885,p.l; C.Baras, Bull. U.S. Geol. Survey No. 36,1886; Bar'usandE. A.Schneider,Zeitschr.pliysikal. , 

Chemie, vol. 8,1S91, p. 285; W. Spring, Rec. trav. cMm.,vol. 19,1900, p. 204; and G. Bodlander, Neues 

Jahrb.,1903, Band 2, p. 147. See als'p T. S. Hunt, Proc. Boston Soc. Nat. Hist., vol. 16,1874, p. 302; W. 

Ramsay, Quart. Jou'r. Geol. Soc., vol.32,1876,p. 129; J. Joly, Proc.Roy. Dublin Soc.,vol.9,1900, p. 325; *« 

L. F. Vernon-Harcourt, Proc. Inst. Civ. Eng., vol. 142,1900, p. 272; and J. Thoulet, Annales des mines, 

8thser.,vol. 19,1891, p. 5. .....

2 Bull. Acad. roy. sci. Belgique, 3d ser., vol. 34,1897, p. 578. -

3 Sixth Ann. Kept. U. S. Geol. Survey, 1885, pp. 249-250. According to S. Weidman (private communication) the clay from Dodgeville is really locssial, and the two from Milwaukee are lacustrine. Accurate T 

diagnosis appears to bo difficult. i

« Trans. Edinburgh Geol. Soc., vol. 8,1901, p. CO. '
THE DECOMPOSITION OF ROCKS. 503

Analyses of clay.

(1). Residuary clays, dried at 100°:

A. From Dodgevillc, Wisconsin, 4J- feet below surface. 

B. The same, S} feet below surlace1. 

C. From Cobb, "Wisconsin, 4J feet below surface. 

D. The same, 8J- foct below surface.

(2) Glacial or drift clays:

E, F. From Milwaukee. Dried at 100°. 

G, II. Scottish boulder clays, MacMe.

SiO........ ..........

AloO,:..............

Fe",0;...............

FoO '

MgO................

CaO. ................

Na^O. ..............

K,0. ...... ..........

&&.. ...............

TiO-,. ...............

P O

MnO. ...............

CO........ ...........

Organic C... ..........

S03 ... ...............

Cl...... ..............

A

71. 13

12.50

5. 52

.45

.38

.85

2.19

1.61

-4.63

.45

.02

.04 .43'

 iq

100. 39

B

49.59

18.64

17. 19

97

.73

.93

.80

.93

10:46

.28

.03

.01

.30

. 34

100. 50

c

49. 13

20.08

11. 04

.93

1 Q9

1.22

1. 33

1.60

11. 72-

iq-

.04

.06QO.

1 OQ1

100.68

B

1 53. 09

21.43

8.53

.86

1.43

.95

1.45

.83

10. 79

.16

.03

.03

.29

.22

100. 09

E

40.22

8.47

2.83

.48

7.80-

15.65

.84

2.36

1.95

.35

.05

Trnrp

18.76

.32 :13-

.06

 100-. 2-7

F

48. 81

7.54

2.53

.65

7.05

11.83

 .92

2.60

2.02

..45

.13

.03

: 15. 47

.38

; .05-

.04

100. 50

a

80.13

9.06

| 2.44

.50

.72

.66

2.08

«4. 11

. 14

99. 84

IF

' 74.89

19 99

| 4.29

.07

1.58

1.06

2.64

a 3. 21

.07

. 17

100. 20

'i Loss on ignition. Must include CO; and organic matter.

III the two Wisconsin cla3^s the carbonates represent magnesian 

limestone. The Scottish clays had evidently a different parentage. 

Glacial clays often contain carbonates, which are rarely conspicuous in rock residues.1 Even residual soils derived from the decay of

i Innumerable analyses of clays and soils have been made for agricultural and other industrialpurposes. 

Several States- have issued special reports upon their clay industries. Among the reports of geological 

surveys arc those of Connecticut,. Bull. No, 4,19Q5,. G. F. Lougjilin; New Jersey, 1S7S,, G. H. Cook; New 

Jersey, vol. C, 1904, H. Ries and H. B. Kummcl; Maryland, vol. 4, pp. 203-503, Hies; Virginia, Bull. No. 

11, 1905> Ries; West Virginia,, vol. 3,1905, G. P. Grimsley; Sooth Carolina, Bull.. No. 1, 4th ser., 1904, E. 

SJoan;: Georgia, Bull. No. G .A.,. 1898, G.. E.. Ladd; Alabama, Bull. No. 6.,. 1900, Ries;. Wisconsin;,Bull. No. 

7,1901, E. R. Buckley; Missouri, vol. 11,, 1896, IT. A. Wheeler; Indiana, Twenty-ninth. Ann. Rept., 1905, 

W. S. Blatchley; Iowa, vol. 14, 1904, S. W. Beyer and I. A. Williams; Wisconsin, Bull. No. 15,1906, Ries. 

See also the. volumes on chemical analyses- published by the geological surveys of Pennsylvania and Kentucky; Bull. New York State Mus., vol. 3, No. 12,1895, Ries; and Bull. IT. S. Geol. Survey No. 228, pp. 

351-370. Ries, Sixteenth Ann. Rcpt. U. S. Geol. Survey, 1895, pp. 554-574; gfvcs'a long^ table of analyses, 

of American clays, and a general report by Ries forms. Prof. Paper. 11.oi the Survey,. 1903., Bull. U. S. 

Geol. Survey No. 143, 1890, by J. C. Branner, is a bibliography of clays and ceramics. The American 

Ceramic Society has since (1906) published; a,more elaborate bibliography by the'same author., Geology 

of North Carolina, vol. 1,1875,. contains much more material on soils, aaid soj, too,, do the volumes on cotton 

production published by the Tenth U. S. Census. The literature regarding soils is too voluminous to> 

adiniti of any summary here. Modem papers' of interest are those by N. Sibirtzew,.Compt. Rend. VII 

Cong. internal geol., 1897, p. 73,. on the soils, of Russia, and by W.. Frear and C.. P. Beistle, Jour. Am. 

Chem. Soc., vol. 25,1903, p. 5. Work by Schlosingand Van Bemmclcn on tropical soils has- already been 

cited;, W. Maxwell (Lavas and soils oi the Hawaiian Islands^ Honolulu, 1898)' and; A. B; Lyons (Aon.. 

Jour. ScL,. 4th ser., vol. 2,. 189fi, p. 421} have, also contributed to this phase, of the subject. On the constitution of arable soils see L. Cayeux,,Ann..S.oc.g(5ol. duNord,voi.34,.1905, p. 146. . On the origin and nature 

of soils see N. S., Shaler, Twelfth Ann. Rept. U, S. GeoL Survey,, pt.. 1,1801,, p, 219. On.fuller's. earth, see 

T. W. Vaughan, Bull. U. S. Geol. Survey No. 213,1903> p. 392, and J. T. Porter, Bull. No, 315,1907, p. 268 

On soils in general see E. W. Hilgard's treatise, "Soils," pubushed in 1906.
504 DATA OF GEOCHEMISTRY.

limestones are practically free from carbonates, as the subjoined 

analyses show. The residues are merely clay or silt entangled with 

the limestone when the latter was laid down and released by its

solution.

Analyses of residual clays.

A. Residual clay from so-called Trenton limestone, Leodngton, Virginia. Analysis by R. B. Riggs. 

Described by I. C. Russell, Bull. U. 8. Geol. Survey No. 52, 1889. Russell especially discusses the cause 

of red coloration in clays. On this subject see also W. 0. Crosby, Am. Geologist, vol. 8, 1S91, p. 72; and 

W. Spring, Rec. trav. chim., vol. 17,1898, p. 202.

B. Residual clay from limestone, Staunton, Virginia. Analysis by George Steiger, U. S. Geol. Survey.

C. Residual clay from Knox dolomite, Morrisville, Alabama. Analysis by W. F. Ilillobrand. Described 

by Russell, op. cit.

SiOo

\] 0

iV2 o3 . ................................................

Feb...................................................

MgO. . .......................................".........

CaO. ...................................................

Na*Q.................. .................................

K O H;O .................................................

H.,0+...... ...........................................

TfO,. . ................................................

P205 .. ................................................

 02 . ..................................................

A

43.07

25.07

15.16

.03

.63

1.20

9 ^O

| 12. 08

100. 64

B

55. 90

19.92

7.30

QQ

1.18

.50

.23

4 7Q

2.54

6.52

.20

.10

.38

99.95

C

55.42

22.17

8.30

TTIPP

1.45

.15

.17

9 QO

9 in

7.76

99.84

LOESS.

In its chemical composition, the widespread earthy deposit known 

as loess closely resembles the glacial clays. 1-t commonly, but not 

invariably, contains much calcium carbonate, and the same is true 

of the related or perhaps identical adobe soil of the more arid regions 

in our Western States. The more striking peculiarities of the loess 

are its light color, its extremely fine state of subdivision, the angularity of its particles, its lack of stratification, its coherence, and its 

porosity. Furthermore, the fossils found in loess are almost without 

exception the remains of land animals, which indicate that it can not 

be a deposit from permanent waters.

Over the origin of loess there has been much controversy, but the 

subject is one that admits of only the briefest summary here. The 

prevalent view is essentially that of F. Richthofen,1 who interprets 

the loess of China as an eolian formation. In the arid regions of 

central Asia the products of rock disintegration are sorted by the 

winds, and the finest blown dust finally comes to rest where it is

i China, vol. 1, p. 74; Geol. Mag., 1882, p. 297. See also R. Pumpelly, Am. Jour. Sci., 3d ser., vol. 17,1879, 

p. 133. For analyses of Chinese loess see A. Schwaget, Geognost. Jahreshefte, 1894, p. 87. For German 

loess, H. G. Sobering, Inaug. Diss., Freiburg, 1909. For South American loess, E-. H. Ducloux, Rev. 

Museo de la Plata, vol. 15, 1908, p. 162. The loess of Argentina has been studied by P. Werlicg, Inaug. 

Diss., Freiburg, 1911. Other analyses of loess arc to be found in the older treatises of Bischof and Roth.
THE DECOMPOSITION OF ROCKS. 505

entangled and protected by the grasses of the steppes. Temporary 

streams, formed by torrential rains, assist in its concentration and 

bring about accumulations of loess in valleys and other depressions 

of the land. According to I. C. Russell,1 the adobe of the Great 

Basin is formed essentially in this way, and the sediments deposited 

in the so-called "playa" lakes, whose beds are dry during a great 

portion of the year, consist of this material. The adobe contains the 

finer products formed by subaerial erosion of the mountain slopes, 

and may be commingled sometimes with dust of volcanic origin. The 

loess of the Missouri and upper Mississippi valleys is given nearly the 

same interpretation by C. R. Keyes, 2 only in this case the dust is 

formed from river silt left on the dried mud banks in times of low 

water.

The loess of Iowa is regarded by W J McGee 3 as a glacial silt, 

deposited along the margins of glaciers during the glacial period. 

W. F. Hume,4 studying the Russian loess, described that also as 

glacial silt, distributed partly by winds and partly by floods. C. 

Davison 5 considers loess to be a product of glacial erosion, accumulated first in banks of snow and concentrated later in the valleys by 

the rush of water following a thaw. T. C. Chamberlin 6 is inclined 

to combine the various theories concerning loess and to regard it as 

both glacial and eolian. Here, again, as in so many other instances, 

we must remember that similar products inay be formed in several 

different ways. The loess of China may be one thing and that of the 

Mississippi Valley another. They are alike in their extreme comminution but not necessarily identical in origin.

A microscopic examination of loess from Muscatine, Iowa, by J. S. 

Diller,7 showed that quartz was its most abundant constituent. 

Orthoclase, plagioclase, and hornblende were also present, with occasional fragments of biotite and tourmaline, some carbonates, and clay 

colored by oxide of iron. The following analyses were made in the 

laboratory of the United States Geological Survey: 8

J Geol. Mag., 1SS9, pp. 2S9, 342.

2 Am. Jour. Sci., 4th scr., vol. 6, 1898, p. 299. Keyes describes the dust storms of tho Missouri Valley, 

in which great quantities of aerial sediments are carried from place to place.

a Eleventh Ann. Kept. U. S. Geol. Survey, pt. 1, 1891, pp. 291, 435. See also F. Lcverett, Mon. U. S. 

Geol. Survey, vol. 38,1899, pp. 153-184, for an account of lowan loess. The loess of Colorado is described by 

S. F. Emmonsin Mon. U. S. Geol. Survey, vol. 27,1890, p. 263.

< Geol.Mag., 1892, p. 549.

6 Quart. Jour. Geol. Soc., vol. 50, 1894, p. 472.

8 Jour. Geology, vol. 5, 1897, p. 795. See also T. C. Chamberlin and R. D. Salisbury, Sixth Ann. Kept. 

U. S. Geol. Survey, 1885, p. 250.

' Bull. U. S. Geol. Survey No. 150, 1898, p. 65.

8 For analyses of Nebraska loess see F. J. Alway and his associates, Soil Science, vol. 1,1916, pp. 197-436.
506 DATA OF GEOCHEMISTRY.

. Analyses of loess. 

A. Near Galena, Illinois. . B. Near Dubuquc, Iowa. 

C. Vicksburg, Mississippi.

D. Kansas City, Missouri. Analyses A to D by R. B, Riggs. Discussed by T. C. Chamberlin and R. D. 

Salisbury, Sixth Ann.. Rept .U.S. Geol.. Survey,. 1SS3, p. 2S2: Samples dried, at 100°. 

E. Cheyenne, Wyoming.

G. Highland, C'olorado. Analyses E to G by L.. G. Eakins- Discussed; by S. F. Einmons,, Mon. IT. S. 

Geol. Survey, vol. 27,1896,. p. 263, together with several other samples.

SiOa . ...............

AUV-- ............

Fe303 - .....-------..

FeO......... .........

MnO................

MgO................

GaO. ...............

Na,0......... ........

K26,-. ..............

H20.................

TiO,. ...............

P20g. ...............

GO

S03 . .................

Cll. ..............

A

64.61 

10.64 

2. 61 

.51 

.05 

3.69 

i 5, 41 

i 1. 35 

-2. 06 

2.05. 

.40 

.06 

6.31 

.13 

.11 

.07

100. 06

®

72. 68.

; 12.03

3. 53 

.96 

.06 

1.11 

1.59 

1.68 

2.13 2., 50' 

.72; 

.23 

,3# 

.09 

.51 

.01

100. 22

e

 60s. 69- 

7. 95 

2.61 

.67 

.12 

' 4.56 

1 8. 96;

. 1. 17 

; 1. OS 

1..14 

..52. 

.13 

9v 63 

.19 

.12 

.08

99. 62'

! B

74. 46 

; 12. 26 

1 3. 25 

; .12 

.02 

1.12 

' 1.69 

; 1.43 

! 1.83 

2. 70

i .14:

1 .09 

..49 

.12.

.0© 

.OS99. 83'

E

i 67.. 10' 

! 10.26 

i 2. 52' 

.31

1.24

i 5-. 88'

: 1. 42

1 2.68;

i 5.. 09.

1 .11

: 3. 67

100: 28

F

69.27 

; 13.51 

3,. 74 

: 1.02 

Trace. 

1.09 

: 2, 29 

1.70 

3. 14 

! 4.19

.45 

Trace'.

100. 4&

G

. 60.97 

15.67 

5.22 

.35 

Trace. 

1.60 

! 2177 

.9? 

; 2.28 

9.83

.19 

.31

100; 1G

The following analyses of adobe soil were made in the laboratory of 

the United States Geological Survey, by L... G. Eakins,.

Analyses of adobe soil.

A. Salt Lak&City,. Utah. 

B.. SantaEer Kew Mexico;.

G. Fort Wiugate, New Mexico-. 

Dv Hiurtboldt, Nevada.

Sio2 :. . . ....-.. .:::....'... .'. ................. :. Ai n

Fe205 --------------------------------------- :

MnO..........................................

MgO..........................................

CaO ..........................................

Na,O... ........................................

K26. ............................................ HO...............:.............-.,..:..-..

p o

c^!::::::::::::::::::::::::::::::::::::::::::

Organic matter. . . . .............................

S03 . ..........................................

01.. .........................................

A

* 19.24

i 3.. 26

: 1.09

Trace.

2. 75

38.. 94

Trace..

Trace.

1.67

.23

29.: 57

2. 96;

.53

.11

.100. 35

s

66.69

! 14,16-

! 4. 38

,09

. 1. 28

, 2..49-

. 67

1.21.

4.94

9Q '.77

2,00

.41.

.34.

99. 72

e

26.67

. 91

.64

Trace.

! g]_

I 36.40

; Trace.

'Fvst-oA

2.26

.75

25, 84.

5,10

..82

,07

99. 97

D

44.64

13.19

: 5.12

T3

2.96

; 13. 91

i .59

1.71

3,8904

8.55

3,43

.64

.14

99.84

The extremely variable but generally calcareous nature of these 

soils is sufficiently indicated.
THE DECOMPOSITION OF BOCKS. 507 

MARINE SEDIMENTS.

The oceanic sediments are naturally complex, for they are derived 

from the most varied sources. Near shore are found the products of 

wave erosion, the silt brought in by streams, remnants of shells and 

corals, and organic matter from seaweeds. In some localities, as 

around coral islands, the debris consists chiefly of calcium carbonate, 

and that compound, as shown in a previous chapter,1 is also formed 

as a chemical precipitate.

Floating ice, the remnants of polar glaciers, deposits more or less 

stony material in the warmer parts of the ocean; and volcanic ash, 

from either submarine or subaerial eruptions, covers large areas on 

the bottom of the sea. Even cosmic dust, which has been gently falling throughout all geologic time, has made perceptible contributions 

to the great mass of oceanic sediments.2

Notwithstanding the diversity of these deposits, their distribution 

is not entirely fortuitous. River silt, for example, is an important 

oceanic sediment only in a belt surrounding the continents and comparatively near shore. In relatively small amounts it is diffused 

through all parts of the ocean, but beyond a certain limit its influence 

is small. The yellow silt of the Chinese Sea, worn by the Chinese 

rivers from erosion of the loess, may be observed as much as a hundred miles from land, 3 and the turbidity of the Amazon is evident in 

the ocean at still greater distances; but the larger part of the deposits 

thus formed are laid down in relatively shallow water. Glacial 

de'bris, of course, occurs only near glaciers and along the tracks followed by icebergs. Certain oceanic areas are characterized by sediments of organic origin; and in the deepest abysses of the ocean its 

floor is covered by a characteristic red clay. These varied deposits 

shade into one another through all manner of blendings, and yet 

they are distinct enough for purposes of classification.

In their great volume upon Deep-sea deposit's, Murray and Renard 4 

adopt a classification which is perhaps as good as any yet devised; 

The following table shows its character and also the distribution in 

depth and area of the several sediments named:

1 Seo p. 127, ante.

2 See J. Murray and A. Renard, Tree. Roy. Soc. Edinburgh, vol. 12,1883-84, p. 474.

3 R. Pompelly, Am. Jour. Sci., 3d sor., vol. 17,1870, p. 133. 

« Challenger Rept., Deep-sea deposits, 1891, table on p: 248.
508 . DATA OF GEOCHEMISTRY.

 Mean depth and area covered by marine sediments.

Littoral deposits (between tide marks) 

Shallow-water deposits (low water to 1(

Terrigenous deposits, near land. . .....<

Pelagic deposits, deep water, far from<

land..............................]

)0 fathoms) ........

[Coral mud....... ..

Volcanic sand .....

Green mud........ 

Green Band........

Red mud .........

JBlue mud ........

Pteropod ooze. . . . 

Globigerina ooze. . . 

Diatom ooze ......

Radiolarian ooze. .. 

Red clav......:...

Mean depth, 

fathoms.

740 

176 

1,033 

243 

513 

449 

623 

1,411 

1,044 

1,996 

1,477 

2,894 

2.730

Area, square 

miles.

62, 500 

10, 000, 000

} 2,556,800 

| 600, 000

} 850, 000

100, 000 

14, 500, COO 

400, 000 

49, 520, 000 

10, 880, 000 

2, 290, 000 

51. 500. 000

For these various products many analyses are given, and from 

among them a few may be cited here. The red clay which covers the 

largest areas is regarded by Murray and Renard as derived from the 

decomposition of volcanic ejectainenta. The several oozes owe their 

names to the remains of living creatures which they contain, and 

calcium carbonate is one of their important constituents. The distribution of calcium carbonate according to depth is discussed in 

another chapter 1 of this work, together with the composition of the 

peculiar manganese and phosphatic nodules which are often found 

in great numbers in the deeper parts of the sea.

Analyses of marine sediments.

A. Red clay. Twenty-three analyses by J, S. Brazier are tabulated on page 198 of Deep-sea deposits, 

and there is a discrimination between the portions soluble and insoluble in hydrochloric acid. Some of 

these analyses show calcium carbonate up to 60 per cent; the one selected here, as representing a more 

typical clay, contains the minimum of carbonate.

B. Radiolarian ooze. Rich in siliceous organisms. Analysis by Brazier, page 436.

C. Diatom oozo. Rich in siliceous organisms. Analysis by Brazier, page 436.

D. Globigerina ooze. Twenty-one analyses are given on page 219. Analysis by Brazier, No. 42, showing 

low calcium carbonate.

E. Globigerina ooze. Analysis by Brazier, No. 53, showing very high carbonate.

F. Pteropod ooze. Analysis by Brazier, page 448.

Si02 . ............ ............

A1203 ........................

Fe203 .............. ..........

Mn02 .......................

PaO

MgO... ......................

CaC08 .......................

CaaPjOj.......... ............

CaS04 .... ....................

MgC03 .......................

Insoluble a ....................

A

4.50 

62.10 

16.06 

11.83 

.55 

.28 

.50 

.92 

.19 

.37 

2.70

100. 00

B

7.41 

56.02 

10.52 

14.99 

3.23 

.29 

.25 

3.89 

1.39 

.41 

1.50

100. 00

C

5.30 

67.92 

.55 

.39

19.29 

.41 

.29 

1.13

4.72

100. 00

D

7.90 

31.71 

11.10 

7.03 

Trace. 

.41

.12

37.51 

2.80 

.29 

1.13

100. 00

E

1.40 

1.36 

.65 

.60

92.54 

.90 

.19 

.87 

1.49

100. 00

F

2.00 

3.65 

.80 

3.06

82.66 

2.44 

.73 

.76 

3.90

100. 00

a, Contains silica, alumina, and ferric oxide, not separated.

, i Chapter IV, p. 129, ante.
THE'DECOMPOSITION OF ROCKS. 509

Analyses of marine sediments Continued.

'G. Blue mud. Analysis by Brazier, page 448.

H. Red mud. Analysis by M. Hornung, page 445. Dried at 100°.

I. Green mud. Analysis by Brazier, page 449.

J. Green sand. Analysis by Brazier, page 449.

1C. Volcanic mud. . Analysis by Brazier, page 400,

All samples dried at 110° previous to analysis. The soluble and insoluble portions in analyses A, B, and 

D arc not separated in the following table.

Analyses G to Kreprcscnt" terrigenous "deposits. Brazier's samples were all dried at 110°. Thesolublo 

and insoluble portions are here united.

Sec also J. B. Uarrisoii and A. J. Jukes Brown, Quart. Jour. Gcol. Soc., vol.-51, 1S95, p. 313, for other 

analyses of red clay and oceanic oozes. For 1-1 recent analyses of red clay, see W. A. Caspari, Proc. Roy. 

Soc. Edinburgh, vol. 30, 1910, p. 183.

Ignition ..............................

SiOo.................................

K\,Q3 . ...............................

TTV>"f>

Mn02 .... .......................:.....

CaO .................................

MgO.................................

Na.,0................ ................

K20. .................................

CaC03 ...............................

CagPoOp.......... I...................

CaSOY..... ...... ....................

MgCO................................

S03 ...................................

CO..................................

Cl..... .................. .............

Less 0=C1.. ...:................

G

5.60

64.20

13.55

8.38

2.51

.25

2.94

1.39

.42

.76

100. 00

H

6.02

31.66

9.21

4.52

25.68

2.07

1.63

1.33

.27

17. 13

2.46

101.98 

.87

101. 11

I

3.30

31.27

4.08

12.72

.30

.12

46.36

.70

.58

.57

100. 00

J

9.10

29.70

3.25

5.05

.22

.13

49.46

T^TQ/^O

1.07

0 09

100. 00

K

r> 99

34.12

Q 99

15.46

nrVo/^o

1.44

99

QO 00

- TVfl c*t>

.27

qo

100. 00

 These analyses serve well enough to show the variable character 

of the oceanic sediments, but they are in several respects incomplete. 

In order to determine the composition of the oceanic clays more 

minutely, two analyses have been made in the laboratory of the 

United States Geological Survey upon material kindly furnished by 

Sir John Murray. The samples analyzed were composites of many 

individual specimens, brought together from all of the great oceans 

and collected partly by the Challenger and partly by other expeditions. 

The data are as follows, reduced to uniformity by rejection of sea 

salts, calcium-carbonate, and hygroscopic water, and recalculation 

of the remainder to 100 per cent.
510 DATA OF GEOCHEMISTRY.

Analyses of composite samples of marine clays.

A. Composite of fifty-one samples of the "red clay." Analyzed by G. Steiger, with special determinations by W. F. Hillebrand and E. C. Sullivan.

B. Composite of fifty-two samples of "terrigenous clays," namely, four "greon muds" and forty-eight 

"bluemuds." Analysis by G. Steiger.

Si02 .. .....................................................

TiO AiA------------ - ----- - -- ---- --- --- ------- : -------

Or O

Fe203 ------- -------------------- ---------------------------

FeO

NiO, CoO. ................................................

MnO.. .....................................................

MnOo. ....................................................

MgO:.. ..;..:.........-....................................

CaO .......................................................

SrO..... ...................................................

BaO .......................................................

K20... ...... ................................................

NO o

VaO.................... .........:.- ._......... ,...,,......

MoO,. ............................:........................

T>O s^r::::::::::::::::::::::::::::r.::::::::::::::::::::::::

CuO.. ....................................................

PbO... ...................................................

ZnO. ......................................................

G..... .....................................................

^0.,.. ....................................................

A

54.48

.98

15.94

.012

8.66

«4

.039

1.21

. 3. 31

1.96

.056

.20

2.85

2.05

.035

.001

T^vi r*A

..... 30

.024

. .008

.005

7.04

100. 000

B

57.05

1.27

17.22

.05

5.07

2.30

.0630

.12

2.17

2.0403 '

.06

2.25

1.05

.03

Trace.

.21

.13

.0160

.0004

.0070

1 fiQ

7.17

99. 9964

These figures give the average composition of the two oceanic sediments and show the distribution in them of the minor and rarer constituents. Even these analyses need to be supplemented by others, of 

which many can be found scattered .through the literature of oceanography.1 The data are abundant, but their value upon the.purely 

chemical side is very uneven.. Few conclusions can be deduced from 

them. J. Y. Buchanan,2 who found free sulphur in a number of 

marine muds, thinks that sulphates were reduced to sulphides by 

passing through the digestive organs of marine ground fauna, and 

points out that matter at the bottom of the sea is subject also to 

reoxidation by dissolved oxygen. When oxidation is in excess of

1 See, for example, K. Natterer, on Mediterranean muds, Monatsh. Chemie, vol. 14,1893, p. 624; vol. 15, 

1894, p. 530; also upon Red Sea deposits, idem, vol. 20,1899, p. 1. L. Schmelck (Den Norske-Nord'havs 

Expedition, pt. 9) gives many analyses of marine clays. J. Y. Buchanan (Proc. Roy. Soc. Edinburgh, 

vol. 18,1890-91, p. 131) reports partial analyses of Mediterranean samples. A. and H. Strecker (Liebig's 

Annalen, vol. 95,1855, p. 177) describe a peculiar mud from the Sandefjord, Norway. A later study of the 

same substance was published by E. Bodtker (Liebig's Annalen, vol. 302,1898, p. 43). For a bibliography 

of oceanic sedimentation see 1C. Andree, Gcol. Rundschau, vol. 3, p. 324,1912. ' -'"''

2 Troc. Roy. Soc. Edinburgh, vol. 18,1890-91, p. 17.
THE DECOMPOSITION ,OE ROCKS. 511

reduction red sediments are formed; if the reducing process preponderates, the sediments are blue. In the Black Sea, according to N. 

Androussow,1 the sulphates contained in the water are also partly 

reduced by micro-organisms, which liberate hydrogen sulphide. A 

portion of this gas is reoxidized, with some liberation of sulphur; 

another part takes up iron from the sediments and forms abundant 

deposits of pyrites. . The calcareous oozes obviously represent calcium carbonate 

absorbed by living organisms from its solution in sea water and deposited with their remains after death. It therefore owes its origin to 

rock decomposition, during which the lime was removed to be carried 

in solution by rivers to the sea. The siliceous oozes were formed in 

a similar manner by radiolarians and diatoms, which, as J. Murray 

and R. Irvine 2 have shown, are able to decompose the suspended 

particles of clay that reach the ocean and to assimilate their silica. 

A slimy mass of siliceous algce analyzed by Murray and Irvine contained 77 per cent of silica, 1,38 of alumina, 16.75 of organic matter, 

and 4.87 of water. The siliceous sponges should also be taken into 

account. Their spicules, and such structures as the skeleton of the 

beautiful EuplecteUa, the so-called Venus's flower basket, consist of 

practically pure opaline silica.3 From materials of this kind, which 

are very abundant in the ocean, these particular oozes were produced, 

but their primary substance silt, or volcanic ash, or atmospheric 

dust came from the decomposition of rocks upon the land. In some 

cases siliceous deposits have been developed in another way, namely, 

by the silicification of shells and corals. Remains of this kind are 

plentifully found in sedimentary rocks, and the process of then: formation can be imitated artificially. A.'H. Church,4 by allowing a 

very weak solution of colloidal silica to percolate through a fragment of coral, succeeded in dissolving away the calcium carbonate 

and leaving in its place a siliceous pseudomorph.

GLATJCONITE.

In oceanic sediments, and chiefly near the "mud line" surrounding 

the continental shores, the important mineral glauconite is found in 

actual process of formation. This green, granular silicate of potassium and iron occurs in rocks of nearly all geologic ages, from the 

Cambrian down to the most recent horizons, and there has been much 

discussion over its nature'and origin. In composition it is exceed-

' Guide des excursions du VII Gong, geol. intenia.t., No. 20,1897, p. 6.. c

2 Proc. Roy. Sac. Edinburgh, vol.'lS, 1800-91, p. 229. . .

o for analysqsj by V,r. C. Wheeler, sco 'Prof. Paper U. S. Geol. Survey No. 102,191 T., p. 7. On the geochcmical significance of silica in regard to early forms of life, see F. W. Clarice, Jour. Washington Acad. Sci. 

vol. 6,1916,p. COS. . '.

 « Jour. Chom. Soc., vol. 15,1802, p. 109.
512 DATA OF GEOCHEMISTRY.

ingly variable, for the definite compound is never found in a state of 

purity, but is always contaminated by alteration products and other 

extraneous substances. As an oceanic deposit glauconite is developed principally in the interior of shells, and organic matter is 

believed to play a part in its formation. According to Murray and 

Renard,1 the shell is first filled with fine silt or mud upon which the 

organic matter of the dead animal can act. Through intervention of 

the sulphates contained in the sea water, the iron of the mud is converted into sulphide, which oxidizes later to ferric hydroxide. At 

the same time alumina is removed from the sediments by solution 

and colloidal silica is liberated. The latter reacts upon the ferric 

hydroxide in presence of potassium salts extracted from adjacent 

minerals, and so glauconite is produced. This view is sustained by 

other evidence, namely, the constant association of the glauconite 

shells with the debris of rocks in which potassium-bearing minerals, 

such as orthoclase and muscovite, occur.2

ff

This theory of Murray and Renard seems to be fairly satisfactory, 

so far as it goes, but it does not cover the entire ground. It applies 

to the glauconite which is now forming upon the sea bottom, but not 

to all occurrences of -glauconite in the sedimentary rocks. In an 

important memoir L. Cayeux 3 has shown that in certain instances 

glauconite has formed subsequent to the consolidation of its rocky 

matrix, and while he admits that organic matter has assisted its 

development within shells, the mineral can be produced by some 

quite different process. What this process is he does not explain; 

he merely shows that glauconite can form without the intervention 

of organisms and that its mode of genesis is at least twofold. Incidentally also he states that ferric hydroxide and pyrite are produced 

by the decomposition of glauconite, an observation which seems to 

indicate that the reactions predicated by Murray and Renard may be 

reversible.

The granules of glauconite from marine mud and from the sedimentary rocks, although not found as definite crystals, have nevertheless a distinct cleavage, and are interpreted by A. Lacroix* as 

monoclinic and analogous to the micas. There is, however, another 

mineral, celadonite, which is regarded by Dana and other writers as 

a separate species, but which resembles glauconite so closely in composition that it may be the same thing. It occurs as a decomposition 

product of augite in various basaltic rocks, is green like glauconite

1 Challenger Kept., Deep-sea deposits, 1891, p. 383.

2 For other discussions relative to the origin of glauconite see C. W..von Giimbel, Sitzungsb. K. Akad. 

Wiss. Miinchen, vol. 1C, 188C, p. 417; vol. 20,1896, p. 545. Also D. S. Calderon, D. F. Chaves, and P. del 

1'ulgar, Anales Soc. espafi. hist, nat., vol. 23, 1394, p. 8. The older literature of the subject is unimportant for present purposes.

a Contributions a re"tude micrographique des terrains sedimentaires: M6m. Soc. g6ol. du Nord, vol. 4, 

pt. 2, 1897, pp. 103-184.
THE DECOMPOSITION OF HOCKS. 513

but earthy in texture, and never granular. It is easily confounded 

with other green chloritic minerals and its diagnosis is never certain 

unless supported by a complete chemical analysis. C. W. von Gumbel 2 and K. Glinka 3 both identify it chemically with glauconite, 

despite its entirely different origin, a conclusion which, if sustained, 

gives us another illustration of the fact that a chemical compound 

may be produced by several distinct processes. Still another mineral, found in the iron-bearing rocks of the Mesabi district, and 

named greenalite by C. K. Leith 4 has been confounded with glauconite, although it is free from potassium and its iron is practically 

all in the ferrous state. In glauconite the iron is mainly ferric, and 

potassium is one of its essential constituents. According to the best 

analyses, glauconite probably has, when pure, the composition represented by the formula Fe'"KSi206 .aq., in which some iron is replaced 

by aluminum, and other bases partly replace K.5 This-formulation 

is not final; neither does it suggest any relationship between glauconite and the micas. It rests upon Glinka's analyses of Russian 

glauconite, in which the material was freed from impurities by means 

of heavy solutions. The water in the formula is probably for the 

most part "zeolitic" and not constitutional, as in the case of analcite, 

a silicate of similar chemical type.

The following analyses of glauconite and celadonite will serve to 

show the variability of the material. 6

1 Mindralogie de la France, vol. 1,1893-1895. p. 407. Lacroix gives a number of analyses of French and 

Belgian glauconitcs.

2 Sitzungsb.'K. Akad. Wiss. Miinchen, vol. 26,1890, p. 5-15.

3 Zoitsohr. Kryst. Min., vol. 30,1899, p. 390. Abstract from a Russian original.

« Mon. U. S. Geol. Survey, vol. 43,1903, p. 240. Leith gives a long table of glauconite analyses.

6 See discussion by F. W. Clarke in Mon. U. S. Geol. Survey, vol. 43,1903, p. 243. Compare L. W. Collet 

and G. W. Lee, Compt. Rend., vol. 142,1900, p. 999. The authors give an analysis of very puro marine 

glauconite. Two other analyses arc given by W. A. Caspari, Proc. Roy. Soc. Edinburgh, vol. 30,1910, p. 

3G4. Caspari also describes the synthesis of a compound resembling glauconite. An important monograph by Collet, Les d<5p6ts marins, was published at Paris in 1908.

8 Many analyses of grecnsand marls are given by G. H. Cook, in Geology of New Jersey, 18G8, pp. 414 

et scq. On New Jersey grecnsands sec also W. B. Clark. Jour. Geology, vol. 2,1894, p. 1C1. On Irish glauconite, sec A. J. Hoskins, Geol. Mag., 1895, p. 317.

113750° 19 Bull. 695 33
514 DATA OF GEOCHEMISTRY.

Analyses of ylauconite and celadonite.

A. Glauconite, from Woodburn. Antrim, Ireland. Analysis by A. P. HosMns, Geol. Mag., 1895, p. 320.

B. Glauconite from Cretaceous sandstone, Padi, Government Saratoff, Eussia. One of ten analyses, 

by K. Glinka (Zeitschr. Kryst. Min., vol. 30,1899, p. 390), of Russian material from the Lower Silurian, 

Jurassic, Eocene, and Cretaceous. This sample lost 4.43 per cent of water at 100°, but regained it in 

twenty-four hours.

C. Glauconite from greensand marl, Hanover County, Virginia. Analysis by M. B. Corse and C. Baskcrville, Am. Chem. Jour., vol. 14,1892, p. 627. 8.22 per cent of the silica is stated separately as quartz.

D. Oceanic glauconito, mean of frnir analyses made by L. Sipocz for Murray and Eenard, Challenger 

Kept., Deep-sea deposits, 1891, p. 387.

E. Glauconite. Monte Brione, Lake Garda, Italy. Analysis by A. Schwager. Described by C. W. von 

Giimbel, Sitzungsb. Akad. Miinchen, vol. 20,1890, p. 545.

F. Celadonite, Monte Baldo, near Verona, Italy. Analysis by Schwager. See C-iimbel, loc. cit.

G. Celadonite, mean of four analyses of material from Scottish localities, by M. F. Heddle. Trans. Roy. 

Soc. Edinburgh, vol. 29,1880, p. 102.

SiOa- ...............

Al O

Fea03 . ..............

FeO

MnO. ...............

MgO................

CaO................

Na^O.... ...........

K20. ................

Li20. ...............

H20. ................

Tin

P205 - ...............

A

40.00

13.00

16.81

10.17

1.97

1.97

2.16

8.21

6.19

100. 48

B

48.95

7.66

23.43

1.32

2.97

.57

.98

9.54

4.93

100. 35

C

51.56

6.62

15. 16

8.33

.95

.62

1.84

4.15

10.32

99.55

D

53.61

9.59

21.46

1.58

Trace.

2.87

1.39

.42

3. .49

5.96

100. 34

E

50.36

7.04

19.13

3.95

.06

4.08

.91

1.58

6.62

.01

1 6.32

.02

.26

100. 34

F

55.80

3.20

16.85

3.88

.12

5.32

.16

1.12

9.04

4.67

Tl*£LC6

.24

.07

100. 47

G

54.84

3.52

12.64

4 00

.24

6.65

.89

.39

7.00

9.62

100. 69

If, now, we assume that celadonite and glauconite are at bottom 

the same ferripotassic silicate, differing only in their, impurities, we 

may begin to see that the several modes of its formation are not absolutely different after all. Probably, in all their occurrences, the 

final reaction is the same, namely, the absorption of potassium and 

soluble silica by colloidal ferric hydroxide. In the ocean these 

materials are prepared by the action of decaying animal matter upon 

ferruginous clays and fragments of potassium-bearing silicates. In 

the sedimentary rocks, when glauconite appears as a late product, 

the action of percolating waters upon the hydroxide would account 

for its formation. In igneous rocks the hydroxide is derived from 

augite, or perhaps from olivine, and percolating waters again come 

into play. Thus the various productions of glauconite and celadonite become the results of a single process, which is exactly equivalent 

to that in which potassium compounds.are taken up by clays. The 

observation of L. Cayeux * that glauconite is frequently present in 

arable soils, in all conditions from perfect freshness to complete

i Annales Soc. ge"ol. du Nord, vol. 34,1905, p. 146.
THE DECOMPOSITION OF HOCKS. 515

alteration into limonite, suggests that perhaps the formation of the 

species is one of the modes by which potassium is withdrawn from 

its solution in the ground waters.

PHOSPHATE ROCK.

Among the phosphates of the igneous and crystalline rocks, only 

one, apatite, has any large significance. Monazite and xenotime are 

altogether subordinate. Apatite, as was shown in previous chapters l is widely distributed, but in relatively small proportions; 

although it is sometimes concentrated into large deposits or in veins. 

The commercially important apatites of Canada, Norway, and Spain 

are segregations of this kind.2

By various processes, which are not yet fully understood, apatite 

undergoes alteration, and by percolating carbonated waters it is 

slowly dissolved. Some of the phosphoric acid, thus removed in 

solution, is carried by rivers to the sea, where it is largely absorbed 

by living organisms. Some of it reacts upon other products of rock 

decomposition, forming new secondary phosphates. Another portion 

is retained by the soil, whence it is extracted by plants, to pass from 

them into the bodies of animals. From organic sources, such as 

animal remains, the largest deposits of phosphates are derived. 

Between the original apatite and a bed of phosphorite there are many 

stages whose sequence is not always the same. v

The solubility of apatite and of the other forms of calcium phosphate has been studied by many investigators.3 R. Muller 4 has 

shown that apatite dissolves in carbonated waters, and the fact that 

the solubility of calcium phosphate is increased by humus acids has 

been observed by H. Minssen and B. Tacke.5 C. L. Reese,0 in a series 

of experiments upon calcium phosphate, found that it dissolved perceptibly in swamp waters rich in organic matter. Carbonated waters 

also dissolved it freely, but it was redeposited when the solution was 

allowed to stand over calcium carbonate. In presence of the carbonate, then the phosphate would probably not be dissolved, while 

carbonate could pass into solution. Other salts in solution may assist 

or hinder the solubility of calcium phosphate, and since natural

i See p. 350 and also the analyses of igneous rocks given in Chapter XI.

 For good summaries relative to the occurrence of economically important phosphates of lime, see R. A. 

F. Pcnrose, Bull. U. S. Ceol. Survey No. 46,1888; A. Carnot, Annales des mines, 9th ser., vol. 10,1890, p. 

137; and E. Nivoit, in Frcmy's Encyclopedic chimique, vol. 5, sec. 1, pt. 2,1884, p. 83. All these memoirs 

contain numerous analyses, and Penrosc gives a bibliography of the subject down to 1888. Beds rich in 

coprolitic nodules arc extensively worked in England.

.3 See F. K. Cameron and L. A. Hurst, Jour. Am. Chern. Soc., vol. 26,1904, p. 885. These writers give 

 abundant literature references. See also Cameron and A. Seidell, idem, vol. 26,1904, p. 1454; vol. 27,1905, 

p. 1503. Earlier papers by S. P. Sharpies (Am. Jour. Sci., 3d ser., vol. 1, 1871, p. 171) and T. Schlosiug 

(Cornpt. Rend., vol. 131, 1900, p. 149) may also be noticed.

< Jahrb. K.-k. geol. Reichsanstalt, vol. 27, Min. Mitt.; 1877, p. 25. See also ante, p. 350.

s Jour. Chem. Soc., vol. 73, pt. 2, 1900, p. 618. Abstract.

8 Am Jour. Sci., 3d ser., vol. 43, 1892, p. 402.
516 DATA OF GEOCH-EMISTKY.

waters differ in composition the solvent process is necessarily variable. 

Cameron and Hurst,1 who studied the solution of iron, aluminum, 

and calcium phosphate, showed that the process is one of hydrolysis, 

the solution becoming acid,2 and less soluble basic phosphates being 

left behind; that is, the solution contains acid ions, corresponding 

either to free acid or to acid salts a condition which must materially 

affect the action of the liquid upon the substances with which it 

comes in contact. R. Warington,3 for example, found that a solution of calcium phosphate in carbonated water was perfectly decomposed by hydroxides of iron and aluminum a reaction which must 

often occur in soils. By reactions of this kind, probably, many wellknown minerals have been produced; but, since iron compounds occur 

in natural solutions more largely than salts of aluminum, the iron 

phosphates are more numerous and more widely distributed. The 

"blue earth," vivianite, Fe3P2O8 .8H2O, for example, is not uncommon in clays; it is found lining beleinnites and other fossils at Mullica Hill, New Jersey; and near Edg'eville, Kentucky, W. L. Dudley 4 

found plant roots almost completely transformed, by a process of replacement, into this mineral. Other phosphates of iron, commonly 

found associated with sedimentary beds of limonite, are dufrenite, 

strengite, phosphosiderite, barrandite, koninckite, cacoxenite, beraunite, ludlamite, calcioferrite, borickite, etc. The aluminum 

phosphates, omitting several of doubtful character, are wavellite, 

fischerite, variscite, turquoise, callainite, peganite, sphserite, evansite, 

wardite, and zepharovichite. Most of these minerals are rare 

species, found in very few localities, and need no further consideration 

here.5 Wavellite, however, has been mined near Mount Holly 

Springs, Pennsylvania, and used as a source of phosphoric acid.6

Aluminum phosphates are sometimes formed by the direct action 

of phosphatic solutions upon igneous rocks, or even upon limestones 

containing much clay. The source of the phosphates in several such 

cases is found in beds of guano deposited by sea fowl upon rocky 

islets, or by colonies of bats in caves. Guano is rich in phosphatic 

material, and a number of distinct mineral species have been discovered in guano beds.7 The following compounds are the best 

known among them:

1 Loc. cit.

2 Apatite gives alkaline reactions. F. K. Cameron and A. Seidell, Jour. Am. Chem. Soc., vol. 27, 1905, 

p. 1510.

8 Jour. Chem. Soc., vol. 19,1866, p. 296.

«Am. Jour. Sci., 3d ser., vol. 40,1890, p. 120.

5 For details concerning these minerals, see Dana's System of Mineralogy and i^ts supplements. On 

the varieties of calcium phosphate known as osteolite and staffelite, see A. Schwantke, Centralbl. Min., 

Geol. u. Pal., 1905, p. 641.

« See G. W. Stose, Bull. U. S. Geol. Survey No. 315,1907, p. 474.

* On the phosphates-found in the bat guano of the Skipton Caves; Australia, see R. W. E. Mclvor, Chem. 

News, vol. 55,1887, p. 215; vol. 85,1902, pp. 181, 217. Mclvor names three of the ammonium-magnesium 

phosphates dittmarite, muellerite, and schertelite.
THE DECOMPOSITION OF .ROCKS. 517 

Monetite. ................................... .HCaP04 .

Metabruehite ............................ .2HCaP04 .3H20.

Martinite ................................ .2H2Ca5(P04)4 .H20 .

Collophanite. ............................. .Ca3P208 .H20.

Bobierrite. . ............................. .Mg3P208 .8H20.

Newberyite. ............................. .HMgP04 .3H20.

Hannayite. ............................... .Mg3P208 .2H2NH4P04 .8H20.

Struvite. ................................ .NH4MgP04 .6H20.

Stercorite. ................................. HNaNH4P04 .4H20.

Several of these compounds, it will be observed, are acid phosphates, and three of them contain ammonium. Dissolved by atmospheric waters, they react upon the decomposing rocks beneath the 

guano and produce changes of a notable kind. Where they find 

limestone, they convert it into calcium phosphate; when they attack 

igneous rocks, they produce a phosphate of aluminum. The lastnamed substance may also be formed from the hydroxide of aluminum which is present in many clays. On the islands of Navassa, Sombrero, Mona, and Moneta, in the West Indies, 1 limestones have been 

thus transformed; the other reaction may be more fully considered 

now.

On Clipperton Atoll, in the North Pacific, J. J. H. Teall 2 found 

a phosphatized trachyte, the alteration being clearly due to leachings 

from guano. A similar alteration of andesite was discovered by 

A. Lacroix 3 on Pearl Islet, off the coast of Martinique. In both 

cases feldspars furnished the alumina for the phosphate that was 

found. Another phosphate of similar character, from the island of 

Redonda, in the West Indies, was described by C. U. Shepard,4 but 

nothing is said of its petrologic origin. Another example, analyzed by A. Andouard,5 came from the islet of Grand-Conne* table, 

near the coast of French Guiana. All of these represent changes 

brought about by percolations from bird guano.

i For the Navassa phosphate, see E. V. d'lnvilliers, Bull. Geol. Soe. America, vol. 2, 1891, p. 75. W. B. 

M. Davidson (Trans. Am. Inst. Min. Eng., vol. 21, 1892-93, p. 139) thinks it may bo a residual concentration from phosphattc limestone and not a guano product. For Sombrero, see A. A. Julic/i, Am. Jour. Sci., 

2d ser., vol. 30, 1863, p. 424. For Mona and Moneta, see C. U. Shepard, jr., Am. Jour. Sci., 3d ser., vol. 23, 

1882, p. 400. See also S. P. Sharpies, Proc. Boston Soc. Nat. Hist., vol. 22, 1883, p. 242, on phosphates from 

the guano caves of the Caicos Islands, which contain considerable admixtures of calcium sulphate. K. 

Martin (Zeitschr. Deutsch. geol. Gesell., vol. 31, 1879, p. 473) has described the deposits of phosphate on tho 

island of Bonaire. N. H. Barton (Am. Jour. Sci., 3d ser., vol. 41, 1891, p. 102) and W. H. Dall and G. D. 

Harris (Bull. U. S. Geol. Survey No. 84, 1892) regard the phosphates of Florida as possibly due to guano 

leachings. The same view was also advocated by L. C. Johnson, Am. Jour. Sci., 3d ser., vol. 45, 1893, 

p. 407. On the Aruba phosphates see G. Hughes, Quart. Jour. Geol. Soc., vol. 41, 1885, p. 80. Phosphatized limestones are also reported on islands of the Marshall, Pelew, and Seychelle groups. See Bull. Imperial Inst., No. 9, 1911, p. 39, and No. 13, 1915, p. 568.

» Quart. Jour. Geol. Soc., vol. 54, 1898, p. 230.

» Bull. Soc. rain., vol. 28, 1905, p. 13. Lacroix (Compt. Rend., vol. 143, 1906, p. 661) has also reported 

an occurrence of phosphatized trachyte on the island of San Thom6, in the Gulf of Guinea. In this case 

again, guano was the agent of alteration.

* Am. Jour. Sci., 2d ser., vol. 47, 1869, p. 428. See also C. H. Hitchcock, Bull. Geol. Soc. America, vol. 2, 

1891, p. 6.

» Compt. Rend., vol. J19, 1S94, p. 1011,
518 DATA OF GEOCHEMISTRY.

In the Minerva grotto, Department of FHerault, France, A. Gautier 1 found brushite, tribasic calcium phosphate, and a phosphate 

of aluminum to which he gave the name minervite. To this he 

first assigned the formula A12P208 .7H2 0, but later investigations 

have shown that potassium is an essential constituent of the mineral. 

This was proved by A. Carnot, 2 who also described a substance 

similar to minervite, from a cave near Oran, in Algeria. In this 

case the phosphatic deposits seem to have been formed by infiltrations from without the cavern, and the same is true of a white, 

pulverulent substance described by J. C. H. Mingaye 3 from the 

Jenolan caves in New South Wales. Here no evidence of guano 

could be found, and Mingaye ascribed the phosphatic solution to 

leachings of river silt containing bones or other organic matter and 

directly overlying the caves. The analyses are as follows:

Analyses of phosphatic deposits.

A. Clipperton Atoll, Tcall.

B. Martinique, analysis by Arsandaux.

C. Rcdonda, Shepard.

D. Minerva Grotto, Gauticr, recent.

E. Minerva Grotto, Carnot. 

F. Oran, Carnot. 

G. Jenolan caves, Mingaye. 

H. Controne, Sicily, Casoria.

p f)

ALjO8 ................

Fea08 ------------

MgO..... ............

CaO.... ....... .-.-..

K20.......... ........

Na20. ...............

(NH4 ),0..... ........

NH3 .."..... ..........

F

CaF................. ci............. ......

S03 .......... .......

SiOo...... ...........

H20...,. .............

A

38.5

25.9

7.4

} 5.0

23 0

99.8

B

41.20

34.20

Trace.

^Frn PA

24.50

99.90

C

43. 20

14.40

16.60

.57

1.60

24.00

100: 37

D

40.40

21.60

.50

.13

7.00

.30

.47

.31

.14

28.73

99.58

E

37. 28

18.59

.83

.33

1.40

8.28

.52

'PvQfVfl

fTVfir*p

Trace.

} 4.35

28.20

99.78

F

35.17

18. 18

.31

5.80

.48

Trace.

Trace.

Trace.

11.60

28.20

99.74

G

40.83

90 70

.20

Trace.

TS*si PP

9.01

1.12

97 fiQ

99.55

Ha

37.10

22.89

1.17

8.04

.02

.61

.36

b 29, 1G

99.35

a This substance, named palmeritc by E. Casoria (Zeitschr. Kryst. Min., vol. 42. KOG, p. 87), from near 

Controne, Sicily, is probably identical with minervite. It was found in a layer under bat guano. See also 

A. Lacroix, Bull. Soc. min., vol. 33, 1910, p. 34. Lacroix assigns a very complex formula lo minervite.

& Loss in ignition.

Although these analyses do not represent pure compounds, they 

yield approximations to simple formulae. A and B are not far

1 Annalcs des mines, 9th ser., vol. 5, 1S94, p. 1. Compt. Rend., vol. 116; 1893, pp. 92S, 1023. Recent 

papers by Gautier are in Compt; Rend., vol. 158, p. 912,1914, and Bull. Soc. ehim., 4th ser., vol. 15,19M, 

p. 533.

2 Annales des mines, 9th ser., vol. 8,1895, p. 319. Compt. Rend., vol. 121,1895, p. 152.

8 Rec. Geol. Survey Now South Wales, vol. 6,1899, p. 111. Mingaye gives analyses of several other phosphates found in these caverns. Phosphates of similar origin are described by D. Mawson and W. T. Cooko 

in Trans. Roy. Soc. South Australia, vol. 31,1907, p. 65.
THE DECOMPOSITION OF ROCKS. 519

from variscite, A1P04 .2H2 0. C suggests the analogous barrandite, 

(Al,Fe)PO4 .2H20. Minervite, especially as shown in Mingaye's analysis, probably contains a salt of the composition H2KA12 (P04 ) 3 .6H20. 

Gautier assigns it a more complex formula and further investigation 

of it is desirable.

The phosphates of the Minerva grotto, according to Gautier, 1 were 

formed by the action of decomposing animal matter upon gibbsite, 

clay, and limestone. In order to support this opinion, he proved 

experimentally that solutions of ammonium phosphate, which, as 

we have seen, may be derived from guano, will produce the required 

transformations. Gelatinous alumina, digested with ammonium 

phosphate, gave a crystalline product resembling nlinervite, and 

even a clay was altered by the reagent. Siderite, FeC03 , similarly 

treated with ammonium phosphate, was converted into a salt of the 

composition Fe3 (P04 ) 2 .6H2 0; and limestone was found to be transformed into calcium phosphate. That is, a, known product of 

organic decomposition will so act upon mineral substances as to 

generate phosphates resembling those that were actually found. An 

outline is thus furnished for a general theory of phosphatization, 

which is supported both by laboratory investigation and by the 

observation of natural occurrences. The decaying animal matter, in 

presence of bones or phosphatic shells, can form soluble phosphates, 

and the latter, acting in solution upon clays, hydroxides, or carbonates, bring about the final transformations.

The larger deposits of calcium phosphate, or phosphorite, are 

probably all of marine origin.2 Unlike the crystalline apatite they 

are amorphous, and may be either compact, earthy, or concretionary. 

Nodular or pebble forms are common. In composition the purest 

phosphorites approach apatite, or, more specifically, fluorapatite, 

Caj-XPOJgF; but some varieties are more nearly the normal tricalcium phosphate, Ca3 (P04 ) 2 . According to A. Carnot,3 the concretionary phosphates are deficient in fluorine, while in the sedimentary 

forms it is present in nearly the apatite ratio. In the phosphorites 

of France, A. Lacroix 4 identifies collophanite, dahllite,

(Ca6 (P04 ) 4 .CaC03 ,RI20) 

and francolite, which also contains calcium carbonate. To the phos-

» Annales des Mines, 9th ser., vol. 5, 1894, p. I. Compt. Rend., vol. 110, 1893, pp. 928, 1023.

3 Even the highly crystallized Canadian apatites of the Grenville series are regarded by W. If. MeNairn 

as originally marine deposits which have undergone metamorphism. Trans. Canadian Inst., vol. 8, p. 495.

3 Compt. Rend., vol. 114,1892, p. 1003.

«Idem, vol. 150, 1910, pp. 1213,1388. See also his Mine"ralogie do la France, vol. 4, pp. 555-586. Other 

valuable papers on the geologic relations of the phosphates are by J. L. Willis, Ottawa Naturalist, vol. C, 

1S92, p. 7; E. Blackwelder, Am. Jour. Sci., 4th ser., vol. 42, J.910, p. 2S5; J. W. Gregory, Trans. Geol. Soc. 

Glasgow, vol. 16, pt. 2,1917, p. 115; F. D. Adams and W. J. Dick, Trans. Canadian Min. Inst., vol. 19, 

1917, p. 321; and W. F. Ferrier, Canadian Mining Jour., vol. 38, 1917, p. 209. On dahllite, etc., see also 

A. F. Rogers, Am. Jour. Sci., 4th ser., vol. 33,1912, p. 475, and Mineralog. Mag., vol. 17,1914, p. 155. To a 

mineral of the composition CajPaOe-CaO Rogers gives the name voelckerite.
520 DATA OF GEOCHEMISTKY.

phorite of Quercy, which is a mixture of the other species, he gives 

the name quercylite.

To apparently homogeneous brown grains from the- chalk of Ciply, 

in Belgium, J. Ortlieb* assigned the formula 4CaO.2P2 05 .Si02 , regarding the substance as a definite mineral species to which he gave 

the name ciplyte. In an Algerian phosphate, G. Schuler 2 found 

chromium to an average amount of 0.057 per cent of Cr2 03 . Oxides 

of iron, alumina, magnesia, calcium carbonate, gypsum, silica, 

sand, and clay are common impurities. Nitrogenous organic matter 

is also often present. Some sorcalled phosphate rocks are merely 

phosphatized limestones, sandstones, or shales. In certain Cretaceous sandstones of Russia, calcium phosphate occurs as a cement 

for the sand grams and also in the form of fossil bones and fossil 

wood. The wood has been completely replaced by phosphate.3 

Although bone is itself largely composed of calcium phosphate, fossil 

bones are not identical chemically with recent bones. The fossils 

show an enrichment in calcium carbonate, iron oxide, and fluorine, 

as A. Carnot 4 has shown, and especially in fluorine. Modern bones, 

from various animals, were found by Carnot to contain a minimum 

proportion of fluorine; Tertiary bones were much richer; Triassic and 

Cretaceous bones still more so; and in bones from Silurian and Devonian formations the ratio of fluoride to phosphate was nearly that 

of apatite. This progressive enrichment in fluorine Carnot attributes 

to the agency of percolating waters, carrying small quantities of fluorides in solution. He cites a number of references to the presence 

of fluorides in mineral springs, and in water from the Atlantic he 

found fluorine to the extent of 0.822 gram in a cubic meter. Iodine, 

which is also of oceanic origin, has repeatedly been detected hi 

phosphorites, but the presence of bromine is more doubtful.5

The small traces of phosphates which are present in sea water are 

more or less absorbed into the shells, bones, and tissues of marine 

animals, and so concentrated to some extent. When the animals die 

their remains are scattered through the ooze of the sea bottom, and 

feebly phosphatic deposits are thus formed. The calcium phosphate, 

however, tends to become still more concentrated, for the carbonate 

with which it is commingled is more freely soluble, and so is partially removed. This process is assisted by the carbonic acid formed 

during the decomposition of the animal, matter.6 Some phosphate

1 Annales Soc. ge"ol. du Nord, vol. 16, 1888-89, p. 270.

a Zeitschr. angew. Chemie, 1898, p. 1101.

' See a table of 18 analyses by A. Engelhardt, Claus, P. Latschinow, and P. Kostychew in Revue de 

ge"ologie, vol. 7, 1867-68, p. 320. The wood, bone, and cement have practically the same composition.

« Annales des mines, 9th ser., vol. 3,1893, p. 155. In a dinosaurian bone from Colorado, L. G. Eakins, in 

the laboratory of the United States Geological Survey, found 2.12 per cent of fluorine.

» See F. Kuhlmann, Compt. Rend., vol. 75,1872, p. 1678.

« See discussion by L. Knift, Neues Jahrb., Beil. Band 15,1902, p. 1. This memcir relates to the distribution of phosphorite in the older Paleozoic formations of Europe.
THE DECOMPOSITION OF BOCKS. 521

is also dissolved, but it is in part redepositcd around nuclei, such as 

shells or fragments of bone, forming the phosphatic nodules which 

are so often found upon the ocean floor.1 Similar nodules are common in beds of phosphorite and in some localities they constitute its 

valuable portions. They are also found disseminated in deposits of 

greensand,- associated with the glauconite which was laid down at 

the same time. The replacement of calcareous shells by phosphates 

was clearly traced by A. F. Renard and J. Cornet 2 in their study of 

the Cretaceous phosphorites of Belgium.

The organic remains which contribute to the formation of phosphorites vary widely as regards richness in phosphates. Bones are 

are very rich, and, so, too, are crustacean remains; mollusks and corals 

are the poorest. As a rule, molluscan shells and corals consist 

mainly- of calcium carbonate, but some brachiopods are highly phosphatic. In a recent lingula, for instance, W. E. Logan and T. S. Hunt 3 

found 85.79 per cent of calcium phosphate. The fossil casts of a gastropod, Cydora, are also, according to A. M. Miller,4 rich in phosphate. The Cambrian phosphates of Wales are regarded by H. 

Hicks 5 as derived in large part from crustaceans, a supposition which 

is borne out by W. H. Hudleston's analyses.6 The shell of a giant 

trilobite contained 17.05 per cent of P2 05 ; the shell of a recent lobster 

yielded 3.26 per cent, and the average amount found in an entire 

lobster was 0.76 per cent. Where crustacean remains are abundant, 

the proportion of phosphoric acid ought to be relatively high.

These early observations have recently been confirmed and extended by a large number of analyses made by W. C. Wheeler in the 

laboratory of the United States Geological Survey.7 From among 

them the following examples have been selected. They represent the 

composition of the inorganic part of the shell or skeleton, after rejecting organic matter and water and recalculation to 100 per cent.

1 See J. Murray and A. F. Renard, Challenger Kept., Deep-sea deposits, 1891, pp. 397-400. Also ante, 

in Chapter IV, p. 134.

a Bull. Acad. roy. sci. Belgique, vol. 21,1891, p. 126.

8 Am. Jour. Sci., 2d ser., vol. 17, 1854, p. 236.

* Am. Geologist, vol. 17,1896, p. 74.

8 Quart. Jour. Geol. Soc., vol. 31, 1875, p. 368. On p. 357 of the same journal there is another paper by 

T). C. Davies on the same region. W. D. Matthew (Trans. New York Acad. Sci., vol. 12, p. 108) has des:ribed phosphatic nodules from the Cambrian of New Brunswick.

6 Quart. Jour. Geol. Soc., vol. 31,1875, p. 376.

' Prof. Paper U. S. Geol. Survey No. 102, 1917, by F. W. Clarke and W. C. Wheeler. For analyses of 

vertebrate bones, both recent and fossil, see E. Fremy, Annales chim. phys., 3d ser., vol. 43, 1855, p. 94. 

On the occurrence of Lingula and Discina in the phosphate beds of Utah, Wyoming, and Idaho, see G. H. 

Girty, Bull. U. S. Geol. Survey, No. 436,1910.
522 DATA OF GEOCHEMISTRY.

Analyses of pliospliatic invertebrates.

A. Lingula anatina Gmelin. Brachiopod.

B. Discinisca limellosa, Broderip. Brachiopod. One group of brachiopods, however, Is almost nonphosphatic.

C. Pliyllogorgia quercifolia Dana. Alcyonarian. The alcyonarians generally contain only small amounts 

of phosphorus. The gen US Lcptogorgia is about as phosphatic as the example given here.

D. CMinectes sapidus Rathbuu. Blue crab.

E. Lithodes mate Linne\ Spider crab.

F. Pandalus plat'fceros Brandt. A shrimp.

G. Crago dalli Rathbun. A shrimp.

II. ChlorideUa cmpusa Say. Mantis shrimp.

SiOa ....... ..........

(Al,Fe)30, 

MsC08 .. ....... ......

CaC03 ..... ..........

CaS04 . ...:...........

Ca3Po08 ......... -....

A

0.91

.54

2.70

1.18

2.93

91. 7.4

100. 00

B

0.85

.58

6.68

8.35

8.37

75.17

100. 00

c

0.34

.26

15.73

79 QQ

2.11

8.57

100. 00

D

0.06

.06

6.69

78.14

.60

14.45

100. 00

E

0.00

.31

8.35

73 07

2.24

16.03

100. 00

F

0.87

.70

8.09 fin Q4.

2'. 46

26.94

100. 00

G

2.94

.95

10.05

54.83

3.79

27.44

100. 00

II

0.06

.50

15.99

28.56

5.33

49. 5fi

100.0

Analyses D to H, of crustaceans are selected from a series of 11 

and serve to show their generally phosphatic character. In addition 

to these, another series of analyses were made by G. Steiger of shells 

of the common lobster, Homarus americanus Milne Edwards,1 which 

tell the same story, but also show that the proportion of phosphate 

varies with the age or size of the animal. In the shell of a small lobster, weighing 10 ounces, there was in the inorganic portion only 13.45 

per cent of calcium phosphate, while that of a large specimen, weighing 5| pounds, contained 26.35 per cent. It was found also that the 

large claws of the lobsters were richer in phosphates than the carapaces. 

All these analyses, however, relate to the larger crustaceans, but there 

are very minute forms which make up an important portion of the 

marine plankton and which, because of then1 enormous abundance, 

are perhaps of greater significance geologically than the more conspicuous species. Two samples of these, representing the genera 

Temora and TJiysanoessa, with hundreds of individuals in each, were 

therefore partially analyzed, 2 and it was found that their inorganic 

portions, although small in amount, consisted almost if not entirely 

of calcium phosphate. These creatures as food for larger animals 

represent an early stage in the concentration of phosphorus from sea 

water.

But this is not all. Many other marine invertebrates are slightly 

phosphatic, and add their contribution of phosphates to the marine 

sediments. Some annelids are rich in phosphorus, and the tubes 

formed by the genera Leodice, Hyalinoecia, and Onuphis are in this 

respect the most remarkable; although the form in which the phos1 See Clarke and Steiger, Proc. Na,t. Acad. Sci., vol. 3, 1919, p. C.

2 See Clarke and Salkover, Jon u Washington Acad. Sci., vol. 8,1918, p. 185.
THE DECOMPOSITION OF ROCKS. 523

phorus is combined is by no means clear. 1 These organisms play 

their part, albeit a small one, in the concentration of phosphorus, and 

the aggregate influence of all these minor agencies must be very large.

The deposits thus formed by animal remains upon the bottom of 

the ocean are at the best but moderately phosphatic. Much of the 

calcium phosphate is redissolved before reaching the sediments, but 

enough remains to be significant. A further concentration is effected 

after the sediments have been elevated into land surfaces, when atmospheric agencies begin to work upon them. First, beds of phosphatic 

chalk or limestone are formed, from which, by leaching with meteoric 

or subterranean waters, the excess of calcium carbonate is washed 

away. The less soluble phosphate then remains as a residuaiy deposit, more or less impure, and varying much in richness. The beds 

near Mons, in Belgium, according to F. L. Cornet,2 were thus derived 

from phosphatic chalk, from which the calcareous shells have disappeared, while the flints, siliceous sponges, and vetebrate bones are 

unchanged. According to Chateau 3 the Eocene phosphates of 

Algeria were concentrated in the same way, from animal and vegetable debris laid down in shallow salt-water lagoons. The beds also 

show signs of local precipitation of phosphates which had previously 

been dissolved. So long ago as 1870 this theory of concentration by 

leaching was proposed by N. S. Shaler, to account for the nodular 

phosphates of South Carolina, and it seems to apply equally well to 

some other phosphorite deposits of the United States.

The phosphorites of Tennessee, which have been somewhat exhaustively studied,5 furnish an excellent illustration of the several 

processes, chemical and mechanical, which have taken part in their 

formation. As interpreted by Hayes and Ulrich, these phosphorites, 

which are partly Ordovician and partly Devonian, were first laid 

down in a shallow sea as phosphatic limestones, deriving their phosphates in all probability from phosphatic brachiopods, such as lingula.

1 See Clarke and Wheeler, Prof. Paper U. S. Geol. Survey No. 102,1917, pp. 18,19.

2 Idem, vol. 42,1886, p. 325.

8 M6m. Soc.inse'n. civils, August, 1897, p. 193. Analyses of Algerian phosphates, by H. and A. Malbot, 

are given in Compt. Rend., vol. 121,1895, p. 442. Tho phosphorites of Tunis are described by P. Thomas 

in Bull. Soc. geol. France, 3d ser., vol. 19, 1891, p. 370. See also 0. Tietze, Zeitschr. prakt. Geologic, 

1907, p. 229, on the phosphates of Tunis and Algeria. Tiotze gives numerous references to the literature of 

thesedeposits. See also C. Pilotti, Pub. Corporeale delle miniere, Rome, 1908.

«Proc. Boston Soc. Nat. Hist., vol. 13,1870, p. 222, and also later in the introduction to R. A. F. Penroso's 

Bull. U. S. Geol. Survey No. 46,1888. For other matter relative to the South Carolina phosphates, see 

0. A. Moses, Mineral Resources U. S. for 1882, U. S. Geol. Survey, 1883, p. 504; P. E. Chazal, Sketch of the 

South Carolina phosphate industry, Charleston, 1904; F. Wyatt, Tho phosphates of America, Now York 

1891; and C. C. H. Milhr, Florida, South Carolina, and Canadian phosphates, London, 1892. Tho earlier 

literature is well summed up in Penroso's bulletin.

5 See publications of the U.S. Geol. Survey as follows: C. W. Hayes, Sixteenth Ann. Rept., pt. 4,1895, 

p. 610; Seventeenth Ann. Rept.,pt. 2,1896,p. 539; Twentieth Ann. Ropt.,pt. 6,cont., 1899,p. 633; Twenty, 

first Ann. Rept.,pt. 3,1901, p. 473; and Bull. No. 213,1903, p. 418. L. P. Brown, Nineteenth Ann. Rept., 

pt. 0, cont., 189S, p. 547. E. C. Eckel, Bull. No. 213,1903, p. 42-1. Tho latest discussion, by Hayes und 

E. 0. Ulrich, is given in Geol. Atlas U. S. Folio 95,1903. See also T. C. Meado-.vs arid L. Brown, Trans. 

Am. Inst. Min. Eng., vol. 24,1895, p. 582; Hayes,idem, vol. 25,1896, p. 19; J. M. SafTord, Am. Geologist, 

vol. 18,1896,p. 261; and W. B. Phillips, Eng. and Min. Jour., vol. 57, 1894, p. 417.
524 DATA OF GEOCHEMISTRY.

Some bones and teeth of .Devonian fishes are also found in these beds. 

The limestones then were subjected to the leaching process, which 

removed carbonates, leaving a mixture of phosphates, clay, and iron 

hydroxide. The soil thus formed was again concentrated by mechanical washing, the moving waters carrying away the clay and finer silt 

from the heavier phosphatic nodules. Some phosphates were also 

dissolved by percolating waters, to be precipitated as a secondary 

deposit in the underlying limestones, or concentrated in limestone 

caverns.

The phosphorites of Arkansas, 1 which occur in an interval between 

the Lower Silurian and "Lower Carboniferous," are probably of 

similar origin to those of Tennessee. At some localities in Arkansas, 

however, phosphates occur as bands of pebbles in Cretaceous beds, 

sometimes associated with greensand. This association and also 

the neighborhood of manganese ores are strongly suggestive of the 

similar association of these substances in the deep-sea deposits described by Murray and Renard. The same processes were followed 

in both the ancient and the modern seas.

Phosphorites and phosphatic marls are found at many other points 

in the southeastern parts of the United States, but they probably all 

originated in the same way, at least so far as chemical processes are 

concerned. The mechanical transportation of phosphatic silt and its 

accumulation in hollows or depressions have doubtless happened in 

many instances, but have no chemical significance. In the Florida 

field, as described by G. H. Eldridge,2 every step of phosphorite formation seems to be represented. Phosphates have been concentrated 

from linestones and also by mechanical washing; they have formed 

secondary replacements, and some were deposited from solution. 

The following analyses were made by George Steiger in the laboratory 

of the United States Geological Survey, upon material collected by 

Eldridge. They show the variability of the Florida rock, a variability 

observed in all other regions.

1 See J.C. Branner,Trans. Am.Inst. Min. Eng.,vol. 26,1896,p.580; also Brannerand J. F. Newsom, Bull. 

Arkansas Agr. Exp. Sta. No. 74, and A. H. Purdue, Bull. U. S. Geol. Survey No. 315,1907, p. 403. The 

Devonian black phosphates of the Pyrenees, described by D. Levat (Annales des mines, 9th ser., vol. 16, 

1899, p. 4), are also comparable with those of Tennessee and Arkansas.

2 Trans. Am. Inst. Min. Eng., vol. 21,1893, p. 196. See also W. B. M. Davidson,idem,p. 139. Eldridge 

cites a number of incomplete analyses of Florida phosphates by T. M. Chatard, all made in the Survey 

laboratory. Other papers on the Florida phosphates, by E. T.Cox, G. M. Wells,and E. W. Codington, may 

be found in Trans. Am. Inst. Min. Eng., vol. 25,1896, pp. 36,163,423; also one by N. A. Pratt; in Eng. and 

Min. Jour., vol. 53,1892, p. 380. See also E. H. Sellards, Third Ann. Rept. Florida State Geol. Survey, 

1909-10, and G. C. Matson, Bull. U. S. Geol. Survey No. 004,1915.
THE DECOMPOSITION"- OF- -HOCKS.

Analyses of Florida phosphates.

525

A. From near Sunnysido, Taylor County.

B, C. From Luravillo district, Suwannee County.

D. From Albion district, Levy County.

sio2 . .........................................

ISO

A1 203 . ........................................

Fe2 03 ...... ...................................

CaO..........................................

MgO........ ..................................

KaO.. .........................................

Na20.........................................

POcS6 ::::::::::::::::::::::::::::::::::::::::::

so............................................

F. ...........................................

H2 0 at 105° ...........................:.......

Ignition .......................................

Less 0 .......................................

Organic C ....................................

A

3.44

.13

1.49

1.43

48.81

.23

Trace.

Trace.

35.93

2.71

.10

2.55

.90

1.98

99: 70 

1.05

98.65

B

5.36

.26

5.41

2.86

42.13

.47

None.

None.

33.37

2.15

.09

2.10

1.84

4.76

100. 80

.88

99.92 

.18

c

10.63

.86

12. 42

2.90

30.93

.29

.20

.27

30.35

1.72

.13

1.95

1.27

7.69

101. 61

.82

100. 79 

.12

D

10.51

.58

91 17

3.10

23.95

.15

| .40

25.38

2.14

.15

1.42

1.27

10.35

100. 57 

.60.

99.97 

.22

A comparatively new phosphate field, one of the largest if not 

actually the largest known, occupies considerable areas in Idaho, 

Montana, Wyoming, and Utah. It is generally agreed that these 

phosphates are original marine deposits, and G. R. Mansfield 1 regards them as having been laid down as aragonitic oolites, which 

were afterward phosphatized by ammonium phosphate developed by 

the bacterial decay of marine organisms. The phosphatization of 

coralline limestones by solutions derived from guano, a process which 

has already been considered, is essentially like that postulated by 

Mansfield. J. T. Pardee,2 however, in the Garrison and Philipsburg 

fields, Montana, found phosphatized shales and sandstones to which 

Mansfield's theory does not easily apply. That the phosphorus came 

originally from living organisms he fully recognizes. 3 The following 

partial analyses of rock from this region are by G. Steiger:

' Am. Jour. Sci., 4th ser., vol. 46,1918, p. 891. 

n Bull. U. S. Cool. Survey No. 640,1917, p. 195.

s For other details relative to the western phosphate fields, see Bull. U. S. Geol. Survey Nos. 315,340, 430, 

470, 543, and 580.
526 DATA OF GEOCHEMISTRY.

Analyses of western phosphates.

A. 2J miles west of Cokevillc, Wyoming. 

B. Dunellan lode, 8 miles southwest of Sage, Utah. 

C. Elsinore claim, 3 miles west of Devils Slide, Utah. 

D. Eight miles southeast of Georgetown, Idaho.

Si02 . .........................................

A1203 ----------------------------------------

Feo03 . . ....................................... Mgo.....................................:....

CaO............ ..............................

Na,0.. .......................................

KjO. ........................................

HjO- .........................................

H20+ .......................................

CO............................ ................ PA...... ......:.....-...... .................. s63 !. .......................... ..............

F. ..........................................

Cl...........................................

A

2.62

.46

.97

.40

.35

48.91

.97

.34

1.02

1. 34

2.42

33.61

2.16

.40

Trace.

95.97

B

1.82

.30

.50

.26

.22

50.97

2.00

.47

.48

.57

1.72

36.35

2.98

.40

Trace.

99.04

G

9.40

Undet.

.90

.33

.26

46.80

2.08

.58

.61

.75

2 14

32.05

2.34

.66

Trace.

98.90

T)

10. 00

None.

.89

.73

.28

45. 34

1.10

.48

1.04

1.14

6.00

27.32

1.59

.60

Trace.

96. 51

NOTE. For other data on American .phosphates see R. A. F. Penrose, Bull. U. S.. 

Geol. Survey No. 46,1888, and also the following publications: Phosphates and marls 

of Alabama, E. A. Smith, Bull. Geol. Survey Alabama No. 2,1892; and W. C. Stubbs, 

Mineral Resources U. S. for 1883-84, U. S. Geol. Survey, 1885, p. 794. The Alabama 

localities yield phosphatic marls and greensands of Cretaceous age. S. W. McCallie, 

Phosphates and marls of .Georgia: Bull. Geol. Survey Georgia No. 5-A, 1896. D. T. 

Day, North Carolina phosphates: Mineral Resources U. S. for 1883-84, U. S. Geol. 

Survey, 1885, p. 788. M..C. Ihlseng, Phosphates of Juniata County. Pennsylvania: 

Seventeenth Ann. Kept. U. S. Geol. Survey, pt. 3, 1896, p. 955.

For phosphorite in Japan see K. Tsuneto, Chem. Zeitung, vol. 23, 1899, pp. 800, 

825. This phosphate occurs in Miocene sandstone and contains some glauconite. 

Good analyses are given.

On phosphate rock in New Zealand see A. R. Andrew, Trans. New Zealand Inst., 

vol. 38, 1905, p. 447. On Christmas Island, Indian Ocean,.E. W. Skeats, Bull. Mus. 

Comp. Zool., vol. 42, 1903, p. 103. On nodules in eastern Thuringia, J. Lehder, 

Neuea Jahrb., Beil. Band 22, 1906, p. 48. On French phosphates, A. Nantier, 

Compt. Rend., vol. 108,1889, p. 1174; and H. Laene, Bull. Soc. ge"ol. France, 3d eer., 

vol. 18, 1889-90, p. 441. On Russian phosphorites, W. Tschirwinski, Neues Jahrb., 

1911, Band 2, p. 51. There are also elaborate reports, in Russian, by J. V. Samoilov. 

For reference see Mineralog. Mag., vol. 18,1917, p. 87. See also a work by.C. Elschner, Die corallogene Phosphat-Inseln Austral-Oceaniens, Lubeck, 1913, and an 

address by J. J. H. Teall, Proc. Geologists' Assoc., 1900, p. 369.

FERRIC HYDROXIDES.

An important class of products, derived from the decomposition 

of rocks, is that which includes the oxides and hydroxides of iron 

and manganese. The residual deposit of ferric hydroxide, known 

as laterite, has already been described; other modes of occurrence 

remain to be considered now.
THE DECOMPOSITION OF ROCKS. 527

Several hydroxides of iron have been given definite rank as mineral 

species. They are:

Turgite....................2Fe203 .H2O. Contains 94.6 per cent Fe203 .

Goethitc..................Fe203 .H20. Contains 89.9 per cent Fe203 .

Limonite.................2Fe203 .3H20. Contains 85.5 per cent Fe203 .

Xanthosiderite. ..........Fe203 .2H20. Contains 81.6 per cent Fe203 .

Liranite..................Fe203 .3H20. Contains 74.7 per cent Fe2 03 .

Of these only one, goethite, is crystalline; the others are amorphous, 

and all sorts of mixtures between them are likely to occur. 1 They 

are also often admixed with siderite, FeC03 , which is itself an important ore of iron. Other impurities are sand, clay, calcium and magnesium carbonates, aluminum hydroxides, manganese compounds, 

phosphates, such as vivianite, organic matter, etc. Some of the 

rJarest metals like gallium, indium, thallium, and rubidium are 

also very commonly present in ores of this class, but only in minute 

traces. They have been detected spectroscopically.2 From an economic point of view all of these minerals are grouped together as 

limonite, for the reason that that species is by far the most abundant 

and forms large ore bodies.

The processes by which deposits of ferric hydroxide are produced 

have already been partly indicated. Residual deposits may be 

formed, as in the case of laterite, or as represented by the gossan 

caps over bodies of sulphide ores. Great outcrops of such ores, 

especially of pyrite or chalcopyrite, are often altered to a considerable 

depth into masses -of porous limonite. Pseudomorphs of limonite 

after pyrite are exceedingly common.3 When sulphides containing 

iron are thus oxidized, some iron is removed in solution as sulphate, 

from which it may be precipitated later as hydroxide. Carbonated 

waters also extract iron from silicate rocks or from disseminated 

magnetite, again forming solutions from which limonite may be 

deposited. The rusty sediments around chalybeate springs are 

illustrations of the latter process. The manganiferous iron ores of 

the Cuyuna district, Minnesota, according to E. Newton,4 are partly 

formed by the alteration of an amphibole-magnetite rock and partly 

by leaching of ferruginous chert by alkaline solutions.

Organic acids also assist in the solution of ferrous compounds and 

furnish to swamp waters the material from which bog iron ores are 

formed. Stagnant swamp waters are often covered by iridescent 

films of ferric hydroxide, produced by atmospheric oxidation of 

ferrous carbonate, in visible exemplification of the process described

1 Perhaps the hydrogoethite, 3Fe2 O3 .4H2 0, of P. A. Zemjatschensky (Zeitschr. Kryst. Min., vol. 20, 

p. 185) is such a mixture.

2 See Vf. N. Hartley and H. Ramage, Jour. Chcm. Soc., vol. 71, 1890, p. 533.

3 On the pyritic origin of iron ores sec H. M. Chance, Eng. Min. Jour., vol. S6, 190S, p. 403, and Trans. 

,Am. Inst. Min. Eng., vol. 39,1909, p. 522. Chance regards this origin as very general.

4 Bull. No. 5, Minnesota Schorl of Mines Exp. Station, 1918.
528 DATA OF GEOCHEMISTRY.

above. The following analysis of a spring water which rises under 

a layer of ore at Ederveen, Netherland, is cited by Van Bemmelen l 

to indicate the source from which the iron oxides were derived. The 

figures refer to milligrams per liter.

Analysis of spring ivater at Ederveen, Netherlands.

Ca............................... 107.6

Mg... 

Fe... 

Mn.. 

K...

Na...

A1 203 - 

Cl...

5.6

19.6

11.4

0.9

10.0

3.3

15.2

S04 . ............................ 0.9

H3P04 ........................... 10.9

C03 . ........................... 207.6

Si02 .. ........................... 18.0

Organic ......................... 56.0

467.0

From waters of this kind deposits are formed under swamps and 

bogs as an impervious hardpan, and also frequently in lakes or ponds. 

Their formation is sometimes very rapid, and instances are cited by 

A. Geikie 2 of Swedish lakes in which layers of bog ore several inches 

thick accumulated in the course of 26 years. According to N. S. 

Shaler,3 bog ores are most abundant along the margins of swamps, 

and often wanting at the centers. When the waters deposit their 

load in presence of much carbonic acid or decaying organic matter, the carbonate, siderite, is laid down; but where the air has free 

access limonite is produced. In muddy waters the silt goes down 

with the iron compounds, forming clay ironstone; and the black band 

ores of the coal measures represent what was once a carbonaceous 

mud.4 In many cases the decomposition of ferrous carbonate solutions is effected or aided by the so-called "iron bacteria," which absorb 

the iron and redeposit it later as ferric hydroxide.5 These organisms 

are found in the ground water and the soil. From sulphate solutions 

the iron may be precipitated by carbonates, phosphates, or by organic 

matter contained in admixed waters. Ferrous sulphate first oxidizes, 

yielding ferric hydroxide and insoluble basic salts.

Beds of limonite sometimes represent a different mode of origin 

from those just described. R. A. F. Penrose 6 suggests that in some

1 J. M. van Bemmelen, C. Hoitsema, and E. A. Klobbie, Zeitschr. anorg. Chemie, vol. 22, 1900, p. 337. 

Analysis by G. Moll van Charante. The phosphoric acid of the water goes to the formation of vivianite.

2 Text-book of geology, 4th ed., p. 187.

»Tenth Ann. Kept. U. S. Geol. Survey, pt. 1,1890, p. 305.

* The literature of these ores is very abundant and voluminous. See especially F. M. Stapff, Zeitschr. 

Deutsch. geol. Gesell., vol. 18, 1865, p. 86; J. S. Newberry, School of Mines Quart., vol. 2, 1880, p. 1; 

H. Sjogren, Neues Jahrb., 1893, Band 2, p. 273, ref.; J. H. L. Vogt, Zeitschr. prakt. Geologic, 1894, p. 30, and 

1895, p. 38; G. Reinders, Verhandl. Akad. Wet. Amsterdam, sec. 2, vol. 5, No. 5; A. 'Gaertner, Arch. 

Ver. Mecklenburg, vol. 51,1897, p. 73; and J. M. van Bemmelen, Zeitschr. anorg. Chemie, vol. 22, 1900, 

p. 313. On the origin of bog iron ore see also E. J. Moore, Econ. Geology, vol. 5, 1910, p. 528, and C. L. 

Dake, Trans. Am. Inst. Min. Eng., vol. 53,1916, pp. 106,116.

* See Van Bemmelen, loc. cit.; G. Tolomei, Zeitschr. anorg. Chemie, vol. 5,1894, p. 102; and authorities 

cited by C. R. Van Hise, A treatise on metamorphism: Mon. U. S. Geol. Survey, vol. 47,1904, p. 826. Also, 

E. M. Mumford, Jour. Chem. Soc., vol. 103,1913, p. 645. Also W. D. Francis, Proc. Roy. Soc., Queensland, 

vol. 28,. 1919, p. 80, and E. C. Harder, Prof. Paper U, S. Geol. Survey, No. 113,1919.

<> Ann, Kept. Geol. Survey Arkansas, vol. 1,1892,~p. 124. See also L. Cayeux, Compt. Rend., vol. 142, 

1906, p. 895.
THE DECOMPOSITION OF ROCKS. 529

cases limonite has been derived from glauconite by a.process of alteration. It may be formed by pseudomorphous replacement of limestones, when solutions of iron compounds percolate through them.1 

Ferriferous limestone, also, may yield residuary deposits of limonite, the oxidation of ferrous carbonate and the solution of calcium 

carbonate going on at the same time. The Clinton ores are regarded 

by A. F. Foerste 2 as formed by the replacement of lime in bryozoan 

remains; although C. H. Smyth 3 has shown that in the oolitic varieties each spherule is made up of concentric layers around a nucleus 

of quartz. He argues that the ores were deposited in the shoal waters 

of the Silurian sea, presumably upon a sandy bottom. The essential 

process, however, precipitation from solution, whether by oxidation, 

by organic matter, or by carbonate of lime, is the same in all cases. 

The iron was dissolved, in the first instance, from ferruginous rocks, 

and then thrown down by any one of the several reactions indicated. 

The iron ores of eastern Cuba 4 are essentially lateritic in character, 

being residues from the decomposition of serpentine, and the same is 

true of the Clealum ores in the State of Washington.5

The precipitated hydroxides of iron vary much in character and 

appearance, and their exact chemical nature, despite the plausible 

formulae assigned to some of the minerals, is by no means clear. In 

color they range from yellow through various shades of brown and 

red, and in texture they differ as widely. J. M. van Bemmelen 6 

regards them as colloidal complexes of ferric oxide and water, to 

which chemical formulae are not properly applicable; and the same 

view is held by him concerning the humus acids and the so-called 

ferrohumates.7 According to P. Nicolardot,8 however, whose investigation is most recent, ferric hydroxide exists in at least six modifications which differ in their physical and chemical properties and 

in their content of water. They are all, he says, polymers of the 

simplest hydroxide.

1 See J. P. Kimball, Am. Jour. Sci., 3d scr., vol. 42,1891, p. 231. See also C. W. Hayes, Trans. Am. Inst. 

Min. Eng., vol. 30,1900, p. 403; Hayes and E. C. Eckel, Bull. U. S. Gcol.'Survey No. 213,1903, p. 233; and' 

S. W. McCallie, Bull. No. 10-A, Geol. Survey Georgia, 1900, p. 19, on the iron ores of that State.

2 Am. Jour. Sci., 3d scr., vol. 41,1891, p. 28.

a Idem, vol. 43,1892, p. 487.

< See A. C. Spencer, Bull. U. S. Geol. Survey No. 340,1908, p. 318; C. M. Weld, Trans. Am. Inst. Min. 

Eng., voi. 40,1909, p. 299; C. K. Leith and \V. J. Mead, idem, vol. 42,1911, p. 90, and vol. 53,1916, p. 75. 

See also W. E. Pratt, idem, p. 101, and J. F. Kemp, Bull. Am. Inst. Min. Eng., Feb., 1915, p. 129. On 

other latcritic oreis see W. G. Miller, Rept. Ontario Bur. Mines, No. 26, p. 318.

» See G. 0. Smith and B. Willis, Trans. Am. Inst. Min. Eng., vol. 30,1901, p. 356.

o Rec. trav. chim., vol. 7,1888, p. 106; vol. 18,1899, p. 86; Zeitschr. anorg. Chemie, vol. 20,1899, p. 185, 

vol. 22,1900, p. 313, vol. 42,1904, p. 281. Also J. M. van Bemmelen and E. A. Klobbie, Jour, prakt. Chemio, 

2d ser., vol. 46,1892, p. 529.

7 See also W. Spring, Bull. Acad. roy. sci. Belgique, 3d ser., vol. 34,1897, p. 578, on the relations of humus 

to iron in natural waters, already cited on p. 502, ante. The same subject has recently been discussed 

by 0. Aschan, Zeitschr. prakt. Geologic, vol. 15,1907, p. 56.

8 Annales chim. phys., 8th ser., vol. 6,1905, p. 334. Nicolardot cites many references to former investigations upon the precipitated hydroxides. See also Otto Rufl, Ber. Deutsch. chem. Gesell., vol. 34, 1901, 

p. 3417.

113750° 1& Bull. 695 34
DATA OF GEOCHEMISTEY.

From what has been said in the preceding paragraphs, it is evident 

that the composition of. sedimentary iron ores must range between 

widely separated limits. They may be mainly ferrous. carbonate, 

either crystalline or amorphous, or principally limonite, with all sorts 

of admixtures of other substances. The following analyses of bog 

ore,. " raseneisenstein," from Ederveen, are given hi the memoir by 

J.. M.. van Bemmelen, C.. Hoitsema, and E. A. Klobbie.1 These variations are shown in ore from a single locality, and the substances mentioned are mostly crystalline. The Fe203 represents the amorphous

variety.

Analyses of bog ore.

A. By G. Reinders. B. By E. A. Klobbie. C. By P. M. Jager. D. By C. H. Kettner.

Fe205 . ........................................

FeCCV....... .................................

MnC03 ................................ ........

CaCO............ ..............................

MgCO.,.. .......................................

Tfo (PC) \

Fe"'PO4 ... . ..................................

CaS04 .. .......................................

AlA----- .---.- --.--- ----. -- - -- - -- --

KC1......... ....-.-..--.-.. ...................

NaCl. ..........................................

Soluble SiO,. . .................................

Sand. . .....:..............'.......................

Hob at 100°. . .................................

H9O, ignition... ..................... ..-..;.._.

; A

10.58

' 90- 77

4.. 04

2.27

.17

4. 30

.07

.93

 .oa

,23

1 49. 30

1.57

3. 68

2. 06

1 100. 00'

B

9 4Q

07 7fj.

.67

4.46

.10

1.75

.21

Trace

Trace.

.82

50.02

.03

.95

1.12

100. 32

C

8 A

30.6

: 4. 0

9 Q

} 49 ' 1

1.8

I Q «

> O. O

'

99.7

B

Qft 40

fi 19

9 Q1

4.10

91

5.47

1.76

.GO

Trace

fPl*q/^fi

6.30

1Q ^0

1 90

12.10

4.. 00

100. 56

The subjoined analyses of linionitic bog iron from Mittagong, 

Australia, are cited by A. Liversidge.2 They are quite different from 

those shown in the preceding group.

Analyses of Australian bog ores.

FeA.................... .......................

A1A... ........................................

MnO. .........................................

MgO. .........................................

CaO.................. .........................

SiOa ...... ..................................... T> n

Sfe:::::."-:.::::::::::::::::::::::::::::::::

H20, conabiixea. ...................................

E

68. 37

: 4. 63

Trace.

Trace.

; Trace.

14. 10

i Trace.

Trace.

3.00

9 79

99,82

F

57. 61

24. 30

6.41

Trace.

i Trace.

i Trace.

Trace.

1.20

10.38

~ 99, 90

; G

! 74.71

3.04

i Trace.

,,43

Trace.

10.10

2.20

Q 70

100. 18

: H

65.84

4.49

1.40

.48

Trace.

14. 27

.25

.11

9 30

' 10. 86

100. 00

1 Zcitschr. anorg. Cheniie, vol. 22,1900, p. 319.

2 Minerals of New South Wales, p. 99. The analyses were made by the "government analyst."
THE DECOMPOSITION OF ROCKS. 531 

MANGANESE ORES.

Manganese, like iron, is also dissolved out from the crystalline 

rocks, in which it is almost invariably present, and by the same agencies. - It may go into solution as sulphate, or as carbonate, to be redeposited as carbonate, oxide, or hydroxide, under various conditions 

and in a variety of forms. A deposition as dioxide, hydrous or 

anhydrous, is very common and is often seen in the dendritic infiltrations which occur in many rocks and in the black coatings which sometimes cover river pebbles or surround manganiferous mineral springs. 

Nodules consisting chiefly of manganese dioxide are abundant on 

the bottom of the deep sea, as described in a previous chapter,1 

and similar nodular forms have been observed that were of recent 

terrestrial origin. May Thresh 2 discovered small hard black nodules 

resembling seeds in the boulder clay of Essex, England; and similar 

bodies were found by W. M. Doherty 3 on the surface of the ground 

in Australia.

Manganese differs from iron, however, in its degree of oxidation. 

Ferrous oxide and hydroxide, as such, are unknown in nature; but 

manganosite, MnO, and pyrochroite, Mn(OH) 2 , are well-known minerals. Manganite, Mn203 .H2 0, corresponds in type with goethite 

and diaspore; and hausmannite, Mn304, is the equivalent of magnetite, although the two species are crystallographically unlike. Poliam'te and pyrolusite, two crystallized forms of the dioxide, Mn02, are 

not matched by any compound of iron, and this oxide forms the 

chief manganese ore. Braunite, to which the formula 3Mn2 03 .MnSi02 

is assigned, is also a crystallized mineral, but its composition, as 

shown by analyses, is somewhat variable. The hydrous psilomelane, 

of uncertain constitution, is often associated with pyrolusite, and 

allied to it are many varieties which have received distinct names. 

These latter ores are amorphous,4 and probably represent colloidal 

complexes, such as were mentioned in connection with the sedimentary ores of iron. The f olio wing analyses represent substances in this 

class, ranging from the crystalline pyrolusite to the earthy wad, or 

bog manganese, the cupriferous lampadite, etc.

1 Seep. 132, ante.

s Jour. Chem. Soc., vol. 82,pt. 2, ref.567,1902. 

8 Kept. Australasian Assoc. Adv. Sci., 1898, p. 339.

4 According to A. Gorgeu (Bull. Soc. min., vol. 13,1890, p. 27), tho variety known as wad is sometimes 

crystallized.
532 DATA OF GEOCHEMISTRY,

Analyses of manganese ores.

A. Pyrolusite, Crimora mine, Augusta County, Virginia. Analysis by J. L. Jarman, Am. Chem. Jour., 

vol. 11,1889, p. 39.

B. Psilomelane, near Silver Cliff, Colorado. Analysis by W. F. Hillebrand, Bull. U. S. Geol. Survey 

No. 220,1903, p. 22. u

C. Psilomelane, Romaneche, France. Analysis by A.Gorgeu,Bull.Soc.min.,vol.l3,1890, p. 23. Partly 

recalculated from the original.

D. Wad, Romaneche, France. Analysis by Gorgeu, idem, p. 27. Partly recalculated. Gorgeu gives 

many analyses of natural oxides and hydroxides of manganese. See Bull. Soc. min., vol. 13, 1890, p. 2J; 

vol. 16,1898,pp. 96,133. Also Bull. Soc. chim.,3dser., vol. 9,1893, pp. 496,650.

E. Varvicite, Austinville, Wythe County, Virginia. Analysis by P. H. Walker, Am. Chem. Jour., 

vol.10,1880, p. 41.

F. Lampadite, or lepidophseite, Kamsdorf, Thuringia. Analysis by Jenkins, for A. Weisbach, Neues 

Jahrb., 1880, Band 2, p. 109. This mineral shows exceptionally high hydration.

MnOn.. .....................

MnOt. .......................

Fe203 ........................

Al O

PbO........................

CuO.........................

NiO.................. .......

CoO.........................

ZnO.........................

CaO.........................

BaO.........................

MgO.. ...... ... y ... ..........

K20.. ........................

TSsitQ. .......................

H20-... .....................

HJ)+.......... ..............

p J-A's-- o ------- ................

Aa O

Sb205 ........................

CaS04 ........................

SiO,. ........................

Insoluble. . ...................

A

95.88

.62

.22

97

.09

.18

.23

| 2.08

.29

99.86

B

76.18

5.71

.34

1.81

Trace.

2.80

.83

.29

3.46

.81

1.41

3.94

.12

2.30

100. 00

C

66.88

8.22

1.45

\ "

Trace.

.40

16.20

.20 } .«,

| 4.65

Trace.

1.50

.25

.15

100. 10

D

64.98

7.27

| 1.10

.30

Trace.

Trace.

Tr&cc

1.65

15.45

Trace.

.80

1 5.00

.05.

.60

.40

.80

1.40

99.80

. E

68.86

7; 51

j 2.23

14.42

} 5.08

1.98

100. 08

F

58.77

9.59

11.48

} 21.05

100. 89

Asbolite is an earthy psilomelane containing much cobalt, which is 

a common impurity in manganese ores. Barium, as shown in the 

analyses, is also a frequent constituent of them. The crystalline 

hollandite, described by L. L. Fermor,1 contains both barium and 

iron, in addition to the manganese. Coronadite, an oxide of manganese and lead, described by W. Lindgren and W. F. Hillebrand,2 

is a mineral of similar character. The minerals of this class are 

commonly interpreted as manganites, that is, as salts of manganous 

acid. Their definiteness is questionable.

These sedimentary ores, and the similar ores produced by the alteration of manganiferous minerals, have diverse origins. F. R. Mallet 3

1 Rec. Geol. Survey India, vol. 36,1908, p. 295. Vol. 37 of the Memoirs of the same Survey, 1909, in four 

parts, is an exhaustive monograph by Fermor on the manganese ores of India. In it he describes as new 

species three other mixed oxide of manganese and iron, to which he gives the names vredenburgite, 5itaparite, and beldongrite.

»Am. Jour. Sci., 4th ser., vol. 18,1904, p. 448.

«Rec. Geol. Survey India, vol. 12,1879, p. 99; vol. 16,1883, p. 116.
THE DECOMPOSITION OF ROCKS. 533

has observed lateritic pyrolusite or psilomelane as an integral portion 

of some Indian laterites. The manganese ores of Queluz, Brazil, 

according to 0. A. Derby,1 are residual deposits derived from rocks 

in which manganese garnet was the most constant and characteristic 

silicate. Bog or swamp deposits are common, and so, in short, the 

sedimentary and residual ores of iron are very fully paralleled. Only 

the gossan ores have no true manganic equivalent. The sulphides 

of manganese are relatively rare, and their oxidation products occur 

only in sporadic cases.2

Manganese and iron, then, are dissolved out from the rocks by the 

same reagents, at the same time, and in essentially the same way. 

They are redeposited under similar conditions, but not absolutely 

together, for a separation is more or less perfectly effected. True, 

nearly all Hmonites contain some manganese, and nearly all psilomelanes contain some iron; but in very many cases the ores of the two 

metals are thrown down separately. How is the separation brought 

about ? To this question various answers have been suggested, but 

only two or three of them have .any modern significance.

According to C. R. Fresenius,3 who has analyzed the deposits 

formed by the warm springs of Wiesbaden, the iron is precipitated 

first as ferric hydroxide. The manganese of the water remains in 

solution much longer as bicarbonate, and is finally laid down as carbonate as an impurity in calcareous sinter; that is, solutions of 

manganese carbonate are more stable than solutions of ferrous carbonate, and the manganese is therefore carried farther. A partial 

separation of the two metals, from the same solution, is thus effected.

The therniochemical arguments of L. Dieulafait * are quite in harmony with the foregoing observations, and, indeed, help to explain 

them. These arguments rest upon the general principle that when 

several reactions may conceivably take place, that one which is 

attended by the greatest evolution of heat will occur. The therniochemical equations used by Dieulafait are as follows:

2FeO + 0 = Fe2 03 + 26.6 Cal. 

2MnO + 20 = 2MnO2 + 21.4 Cal.

Hence, if oxygen acts on a mixture of FeO and MnO, or upon sub1 Am. Jour. Sci., 4th ser., vol. 12,1901, p. 18.

2 A very full monograph on manganese ores, by B. A. F. Penrosc, forms vol. 1 of the Annual Report of 

tho Arkansas Geological Survey for 1890. See also an article by Penrose, Jour. Geology, vol. 1,1893, p. 356. 

J. D. Weeks has reported on the manganese deposits of the United States in Mineral Resources U. S. for 

1892, U. S. Geol. Survey, 1893, p. 171. T. L. Watson (Trans. Am. Inst. Min. Eng., vol. 34, 1904, p. 207) 

has described the manganese ores of Georgia. The manganese ore of Golconda, Nevada, which contains 

tungsten, is interpreted by Penrose (Jour. Geology, vol. 1,1893, p. 275) as probably a spring deposit. On 

the carbonate ores of Las Cabesses,in the Pyrenees, see C. A. Moreing, Trans. Inst. Min. Met., vol. 2,1894, 

p. 250. See also J. 1-J. L. Vogt, Zeitschr. prakt. Geologic, 1906, p. 217, for an elaborate paper on bog manganese. Bull. 427 of the U. S. Geol. Survey, 1910, is a report by E. C. Harder on the manganese ores of the 

United States. . >

8 Cited by G. Bischof, Lehrbuch dcr chcmischen und physikalischen Geologic, 2d ed., vol. 1, p. 540a

«Compt. Rend., vol.-101,1885, pp. 609, 644, 67C.
534 DATA OF GEOCHEMISTRY.

i

stances equivalent to them, ferric oxide will form first and be the 

more stable.

FeO + C02 = FeC03 + 5.0 Cal. 

6.8 Cal.

V^ hen carbon dioxide unites with these oxides, then, the manganese 

compound will form first and be the more stable. If oxygen and 

carbon dioxide act together in considerable excess, Fe203 and MnO2 

will both be formed; but if they act slowly, hi small quantities, the 

oxygen will go to produce Fe203 , and MnC03 can be generated at 

the same time. The manganese carbonate, being somewhat soluble, 

may then be separated from the ferric oxide by leaching, either to 

be deposited as carbonate, or perhaps to be oxidized to MnO2 and 

C03 later.

In the last of Dieulaf ait's papers he gives the heat of formation 

of several manganese compounds:

Mn + S, 22. 6 Cal.

Mn-fO, 47.4 Cal.

Mn + O + CO2 , 54.2 Cal.

Mn + 02 , 58.1 Cal. .

From these figures it appears that the dioxide is the most stable 

compound in the series; it is therefore the easiest formed, and is the 

principal manganese ore. The thermochemical and geological data 

are in complete harmony.

It is more than probable, as F. P. Dunnington * has shown, that 

manganese sulphate plays an important part in the separation of 

the two metals. He has proved experimentally that acid solutions 

of ferrous sulphate, such as are formed by the oxidation of pyrites, 

will dissolve manganese oxides to a very marked extent. At the 

same time ferric sulphate and ferric hydroxide, under favorable 

conditions, may also be formed. In contact with manganese carbonate, in presence of ah1 , ferrous sulphate is rapidly oxidized, producing ^manganese sulphate, ferric hydroxide, and carbon dioxide. 

Both sulphates of iron react with calcium carbonate, and the ferric 

salt generates carbon dioxide, ferric hydroxide, and calcium sulphate. Manganese sulphate acts but little,, if at all, upon calcium 

carbonate, if protected from access of air; in presence of air, however, manganese oxide is gradually formed.

From these reactions it is easy to see that limestones may be important factors in the separation of manganese and iron. Where sulphates of two metals percolate through limestones, the iron 

will be by far the more easily precipitated, while the manganese will 

remain in solution until it is exposed to both air and calcium carbonate simultaneously.

i Am. Jour. Sci., 3d scr., vol. 36, 1SSS, p. 175.
CHAPTER XIII. 4 

SEDIMENTARY AND DETRITAL ROCKS.

SANDSTONES.

By pressure, or by the injection of cementing materials, the products of rock decomposition may be reconsolidated. From the sands 

sandstones are formed; from the clays shales are derived; and calcareous deposits yield the limestones. These rocks shade into one 

another, through intermediate gradations, and exhibit the same variations in composition that are observed in sands and soils. Their 

classification depends upon their typical forms, and their modifications are indicated by a simple nomenclature. Such terms as calcareous sandstone, argillaceous limestone, and sandy shale explain 

themselves, for they are clearly descriptive. Although not rigorous, 

they are sufficient for most practical purposes.1

A sandstone differs chemically from a sand chiefly in the addition 

of a cementing substance. This is furnished by percolating waters, 

or else, in certain cases, by the slight solution of the moist surfaces 

of mineral particles in contact with one another. Any substance 

which the waters can deposit in a relatively insoluble condition may 

serve as a cement. Such substances as silica, calcium carbonate, 

hydroxides of iron and aluminum, calcium sulphate, phosphate, and 

fluoride, barium sulphate, etc., fulfill this condition. Clay and bituminous substances also act as cementing materials. The additions 

thus made to a sand may be small in amount or even very large, sometimes equaling in quantity the cemented particles. Such an extreme 

case is furnished by the well-known Fontainebleau calcites, which 

have crystallized around sand and contain sometimes 50 per cent of 

calcium carbonate. A. von Morlot 2 reports crystals from this locality 

containing 58 per cent of sand, and others with as high as 95 per 

cent. Analogous crystals from the Badlands of South Dakota, described by S. L. Penfield and W. E. Ford,3 contain approximately 

40 per cent of calcite to 60 per cent of sand. These are mixtures of 

sand and calcite in which the crystalline form of the latter has been 

perfectly developed. Gypsum crystals containing sand up to 45.58 

per cent have been found on the Astrakhan steppe, according to 

B. Doss,4 who also mentions gypsiferous sandstones. Crystals of

i On a classification of the sedimentary rocks, see A. W. Grabau, Am. Geologist, voL.33,1004, p. 228.

- Haidinger's Ber., vol. 2,1846-47, p. 107.

s Am. Jour. ScL, 4th ser., vol. 9,1900, p. 352.

< Zeitschr..Deutsch. geol. Geseil., vol. 49,1897, p. 143.

535
536 DATA OF GEOCHEMISTKY.

barite inclosing sand are also well known. J. E. Pogue 1 has described 

crystallized barite inclosing 44 to 53 per cent of sand from the oasis of 

Kharga, Egypt; and H. W. Nichols 2 reports similar material found 

in Oklahoma. As a rule, however, the cementing material of a sandstone is subordinate. Between a sand and a sandstone the difference 

in composition is generally slight and may be almost inappreciable.

When silica serves as the cementing substance, it may assume 

either the amorphous or the crystalline form. In the latter case the 

quartz fragments often exhibit a secondary enlargement and become 

the nuclei of distinct quartz crystals.3 As amorphous silica it simply 

fills the interstitial spaces of the rock and binds the sand grains 

together. These spaces or pores vary in magnitude, and may make 

up a considerable portion of the total volume of a rock. According 

to G. F. Becker, 4 the interstitial space in a sandstone made up of 

closely packed spherical grains amounts to 25.96 per cent. C. R. 

Van Hise 5 estimates the minimum pore space at 24 per cent, and 

claims that it may be much greater. The character of the rock produced by the consolidation of such a bed will obviously depend upon 

the extent to which the cementing material has filled the interstitial 

spaces. One sandstone is loosely compacted, another is solid, and by 

thorough silicification the rock may become transformed into a hard, 

vitreous quartzite. In an ordinary sandstone the fracture is around 

the grains; in a quartzite it is just as likely to be across them.

After silica, and often with silica, the commonest cements of sandstone consist of carbonates.6 Calcium carbonate is the most abimdant salt derivable from percolating waters, and is easily deposited 

therefrom; hence its frequency in the sediments, even in those which 

were not laid down in proximity to limestones. Calcareous sandstones 

are exceedingly common, and at the other end of the series arenaceous limestones are not rare. The following analysis of a greenish 

sandstone from Lohne, Westphalia, by W. von der Marck, 7 may 

illustrate the complexity of these mixtures.

1 Proc. U.S. Nat. Mus., vol. 38,1910, p. 17. Pogue gives a good list of other occurrences.

2 Pub. No. Ill, Field Columbian Mus., 1906, p. 31.

s See A. Knop, Neues Jahrb., 1874, p. 281; A. S. Tornebohm, Neues Jahrb., 1877, p. 210; H. C. Sorby, 

Quart. Jour. Geol. Soc., vol. 36,1880, Proc., p. 46; A. A. Young, Am. Jour. Sci., 3d ser., vol. 34,1882, p. 47; 

R. D. Irving and C. R. Van Hise, Bull. U. S. Geol. Survey No. 8,1884; Irving, Fifth Ann. Rept. U. S. Geol. 

Survey, 1885, p. 218: ' 'Crystallized sands" from Peru are mentioned by L. Crosnier," Annales des mines, 

5thser., vol. 2,1852, p. 5, and A.Daubrde (Etudes synthStiquesde geologic expfrimentale, pp. 226V230), 

cites a number of European examples.

< Won. U. S. Geol. Survey, vol. 13,1888, p. 399.

& Idem, vol. 47,1904, p. 863.

o Calcium carbonate, up to nearly 30 per cent, is the cementing substance of the sandstone reefs found 

on the coast of Brazil. See the important monograph by J. C. Branner, which forms vol. 44 of Bull. Mus. 

Comp.Zool.,1904. Branner mentions similar reefs in the"Levant.

'Verhandl. Naturhist. Ver. preuss. Rheinlande u. Westfalens, vol. 12, 1855, p. 269. Many other 

similar analyses are given. G. Bischof (Lehrbuch der chemischen und physikalischen Geologic, 2d ed., 

vol. 3, pp. 137-149) gives abundant data upon the' cementing materials of sandstones. In. analyses of 

these rocks it is commonly assumed that the portion soluble in hydrochloric acid belongs wholly to the 

cement. This is probably true in most cases, but not always. Soluble minerals may occur in a sandstone 

among its granular components.
SEDIMENTARY AND DETRITAL ROCKS. 537 

Analysis of sandstone from Viestphalia.

Ga,G03 ..................................... 39.50

Soluble portion..

..................................... 7.23

FeC03 .................................... 7.54

Ca3P208 . .................................. 3. 90

......................... .......... .82

A1203 ..... ................................. 2.12

T . , , t . /Si02 . ..................................... 36. 65 Insoluble portion.. j ., Q n-.

ILXK. .................................... .03

H0...................................... .62

99.32

In this analysis calcium phosphate appears among the cementing 

substances, and many other examples of its occurrence under like 

conditions are known. Phosphatic sandstones from Perry County, 

Tennessee, have been described by C. W. Hayes, 1 and also a 

phosphatic breccia. In these rocks the calcium phosphate forms 

the matrix of the sand grains. In a brown sandstone from Kursk, 

Russia, C. Claus 2 found 13.60 per cent of P205 , equivalent to 22.64 

of Ca3P2 08 . In the same sandstone 4.98 per cent of calcium fluoride 

was also present. Calcium fluoride has also been reported by 

W. Mackie 3 as a cementing material in a Triassic sandstone from 

Elginshire, Scotland in one specimen as much as 25.88 per cent. 

These figures, of course, represent exceptional samples concentrations, so to speak; in ordinary cases the cementing compounds are 

found in small amounts.

Barium sulphate has repeatedly been observed as a cement in 

sandstones. F. Clowes 4 has described specimens containing from 

28.20 to 60.06 per cent of BaS04 . Clowes suggests that the barite 

was probably formed in situ, by double decomposition between 

barium carbonate and sulphates contained in percolating waters. 

Barium has often been detected in the waters of mineral springs.5 

The barytic sandstones, so far as they have been described, are 

remarkably durable, because of the insoluble character of the cement. 

Calcareous sandstones are easily disintegrated by weathering, for 

the carbonates are readily dissolved by atmospheric waters.

Apart from the cements, sandstones vary in composition exactly. 

as do the sands. A sandstone may be nearly pure quartz, or quartz 

and feldspar, or micaceous, or glauconitic, and it can exhibit any 

texture from the finest to the coarsest. Textural differences,

1 Seventeenth Ann. Kept. U. S. Geol. Survey, pt. 2, 1896, -pp. 527, 539.

8 Jahresb. Chemie, 1852, p. 980.

s Kept. Brit. Assoc. Adv. Sci., 1901, p. 649. See also O. Miigge, Ccntrabl. Min., Geol. u. Pal., 1908, p. 33.

« Proc. Roy. Soc., vol. 46, 1889, p. 363; vol. 64, 1899, p. 374. See also W. Mackie, Rept. Brit. Assoc. Adv. 

Sci., 1901, p. 649; C. B. Wedd, Geol. Mag., 1899, p. 508; and C. C. Moore, Proc. Liverpool Geol. Soc., vol. 8, 

) 89S, p. 241. Moore gives several good analyses of sandstones. In some of them small amounts of cobalt 

and nickel were found.

e See ante, p. 199. See also R. Delkeskamp, Notizbl. Ver. Erdkunde, 4th ser., Heft 21, 1900, p. 47.
538 DATA OF GEOCHEMISTRY.

however, do not concern the chemist. From a chemical point of 

view it is immaterial whether the sand grains are coarse or fine, 

rounded or angular. Such rocks as conglomerates, breccias, arkoses, 

graywackes, etc., have no distinct chemical peculiarities; they are 

made up of detrital material, and vary from their parent formations 

only in the extent to which then* component fragments have been 

decomposed and in the nature of their cementing substances. Any 

sand or detritus may be reconsolidated by any one of the cements 

above mentioned. When a mixture of sand and clay consolidates, 

it may form an argillaceous sandstone or a sandy shale, according 

to the relative proportions of the two ingredients. In such a sandstone the colloidal substances of the admixed clay appear to act as 

binders, their function being somewhat different from that of the 

cements deposited by solutions. Then: binding power is probably, 

in most cases, reinforced by the addition of true cements, usually 

either calcium carbonate or silica. By secondary reactions, due to 

additions of this kind, the clay substances may be transformed into 

other things, as shown in the graywacke of Hurley, Wisconsin. 1 

This is a detrital rock, which originally consisted largely of quartz 

and feldspar, with a little hornblende, and dark fragments of older 

rock material, held together by clay. In the graywacke the clay has 

been transformed into what is principally a chlorite, with secondary 

quartz and some other minor minerals. The cement, which was at 

first amorphous, is now entirely crystalline. Metasomatic changes 

of this order are very common, and the reactions which can occur 

are many. With different detritus, different cements, and different 

salts in the circulating waters, a vast number of transformations 

are possible. On this subject it would be difficult to generalize.

In a microscopic study of about 150 psammites, as rocks of the 

sandstone class are sometimes called, G. Klemm 2 identified the 

following substances among their components: Quartz, feldspars, 

micas, iron ores, zircon, rutile, apatite, tourmaline, garnet, titanite, 

augite, hornblende, opaline silica, glauconite, carbonates of calcium, 

magnesium, and iron, rock fragments, clastic dust, and clay. Even 

this list is probably far from being exhaustive. An arkose sandstone 

from the quicksilver region of California, made up of granitic detritus, 

was found by G. F. Becker 3 to contain quartz, orthoclase, oligoclase, 

biotite, muscovite, hornblende, titanite, rutile, tourmaline, and apatite. In short, all of the rock-forming minerals which can in any 

way survive the destruction of a rock may be found in its sands, arid 

therefore in the sandstones. The feldspars and ferromagnesian minerals, however, are quite commonly altered or even removed, the more

1 Described by W. S. Bayley in Bull. U. S. Geol. Survey No. 150,1898, p. 84. Compare C. K. Van Hisc, 

Am. Jour. Sci., 3d ser., vol. 31,1886, p. 453, for data concerning other similar rocks in the same region.

2 Zeitschr. Deutsch. geol. Gesell., vol. 34,1SS2, p. 771.

»Mon. U. S. Geol. Survey, vol. 13,1888, p. 59. Several other sandstones are described by J. S. Diller 

in Bull. U.S. Geol. Survey No. 150,1S98, pp. 72-84. 
SEDIMENTARY AND DETEITAL EOCKS. 539

scable minerals, like quartz, being much more persistent. Quartz is 

the most abundant mineral in these rocks, while in rocks of the 

crystalline and eruptive classes it is subordinate to the feldspars. 

The following analyses, which, with one exception, were all made 

in the laboratory of the United States Geological Survey, will suffice 

to show the general composition of the sandstones: 1

Analyses of sandstones.

A. Potsdam sandstone, Ablemans,, Wisconsin. Analysis by E. A. Schncidcr. Described by J. S.Diilcr, 

Bull. U. S. Gcol. Survey No. 150,1898, p. 80. Nearly pure quartz.

13. Brown sandstone, Hummolstown, Pennsylvania. Analysis by Schncidcr. Described by Dillcr, op. 

cit., p: 77. Composed chiefly of quartz, with some feldspar, kaolin, etc. The cement is iron oxide.

C. .Ferruginous sandstone, "carstone," from Hunstanton, Norfolk, England. Analysis and description 

by J. A. Pliillips, Quart. Jour. Geol. Soc., vol. 37,1881, p. 6. Consists of quartz grains cemented by brown 

iron ore, with very little feldspar and mic?. Phillips also gives five other analyses of British sandstones.

D. From a "sandstone dike" in Shasta County, California. Analysis by T. M. Chatard. Described by 

J. S. Diller, Bull. Gcol. Soc. America, vol. 1,1889, p. 411. Made up of quartz, feldspar, and biotitc, with a 

calcite cement. Contains also serpentine, titanite, magnetite, and zircon. Other "sandstone dikes," near 

Pikes Peak, Colorado, have been described by W. Cross. They probably represent quicksands which wore 

injected into fissures. See also C. 0. Crosby, Bull. Essex Inst., vol. 27,1895, p. 113.

E. Miocene sandstone, Mount Diablo, California. Analyzed and described by W. n. Melville, Bull. 

Gcol. Soc. America, vol. 2,1890, p. 403.

F. Composite analysis of 253 sandstones. By H. N. Stokes.

G. Composite analysis of 371 sandstones used for building purposes. By H. N. Stokes.

H. Graywacke, Hurley, Wisconsin. Analysis by H. N. Stokes. Described by W. S. Baylcy, Bull. 

U. S. Geol. Survey No. 150,1898, p. 84. Contains quartz, feldspars, iron oxides, and probably kaolin. In 

the cement arc chlorite, quartz, magnetite, pyrite, rutilc, sometimes biotitc, and either muscovitc, or kaolin.

SiO-.. . ......... ......

TiOo......... ........

A1A----- -----------

Fea03 - --------

FpO

MnO........... ......

CaO..... ............

SrO..... .............

BaO.... .............

MgO.. ....... ........

N^O......... .......

K20..................

Li2 0. ................

HaO.................

H20+.......... ......

P205 -- ------ -- --- co,!.. ...............

QA

Cl....................

A

99.42

1 31 f "ii

1 IS r - lh

99.91

B

88.13

5.81

1.77

.31

.20

.53

.06

2.63

.23

.26

99. 93

.C

49.81

5.17

29.17

.35

2.43

.95

.84

.48

3.85

6.56

.42

100. 03

I)

48.13

.24

11. 19

1.25

1.47

.29

16.39

.04

2.22

2.29

1.17

.78

1.78

.14

12.73

100. 11

.E

44.54

12.63

2.50

3.08

:44

14.65

5.55

3.35

1. 37

1.43

2.25

.29

7.76

99.84

F

78. 66 .

.25

4.78

1.08

.30

Trace.

5.52

Tnrr*

.05

1.17

.45

1.32

.31

a 1. 33

.08

5.04

.07

Trace.

100. 41

G

84.86

.41

5.96

1.39

.84

Trace.

.1.05

1\ rmo

.01

.52

.76

1.16

Trarp

.27

« 1.47

.06

1.01

no

Trace.

99.86

H

76.84

11. 76

.55.

2.88

T^VO (-*(*

.70

1.39

£.57

1. 62

1 1.87

100. 18 :

a. Includes organic matter.

A peculiar rock, which is sometimes called a calcareous sandstone, 

is the gaize of the French geologists. It has been fully described by

1 For additional analyses, sec Bull. U. S. Geol. Survey No. 228, 1904, pp. 291-296. W. Wallace (Proc. 

Philos. Soc. Glasgow, vol. 14,1883, p. 22) and W. Mackie (Trans. Edinburgh Gcol. Soc., vol. 8,1899, pp. 58, 

59) give a number of good analyses of Scottish sandstones. See also C. C. Moore, Proc. Liverpool Gcol. 

Soc., vol. 8, 1898, p. 241, for English examples.
540 DATA OF GEOCHEMISTRY.

L. Cayeux 1 as a siliceous rock, rich in the debris of siliceous organisms, containing quartz and glauconite cemented by opal and clay, 

with sometimes chalcedony, and very little carbonate of lime. The 

silica in gaize ranges from 76 to 92 per cent, and a large part of it, 

75.3 per cent in the maximum, is soluble in caustic alkalies. It is, as 

defined by Cayeux, a sedimentary rock, consisting largely of nonclastic silica, and seems to have been originally a marine ooze.

FLINT AND CHERT.

It is at once evident that a considerable variety of rocks may be 

formed from siliceous oozes, such as the radiolarian and diatomaceous 

oozes of the Challenger. expedition. These fine sediments may be 

mixed with more or less clay, sand, or calcareous matter, shading, 

when consolidated, into shales, sandstones, or siliceous limestones. 

Their geological relations and their content of amorphous or opaline 

silica must be depended upon to define them. In the same category 

we must place infusorial earth, which consists mainly of the siliceous 

remains of diatoms; and such rocks as flint, chert, and novaculite 

fall in some cases, if not always, under this general classification. 

With some exceptions these rocks are commonly of organic origin; 

The novaculite of Arkansas, however, has been differently interpreted.2 

It is regarded by L. S. Griswold as a siliceous sediment or silt; in 

other words, as sandstone of extremely fine grain. No organisms 

could be positively detected in it, nor does it contain an appreciable 

amount of soluble silica. It is, according to Griswold, essentially 

a shale minus the argillaceous component, and it forms part of a 

sedimentary series in which all gradations from shale to novaculite 

occur. F. Rutley,3 however, dissents from Griswold's views, and 

has sought to show that the novaculite is a siliceous replacement or 

pseudomorph after limestone or dolomite. It has also been regarded 

as a chemical precipitate, analogous to siliceous sinter. In composition the novaculite is very nearly pure silica.

The much commoner variety of compact silica known as chert has 

also been diversely interpreted. A number of writers, 4 studying chert 

from different localities, have argued in favor of the replacement

1 M6m. Soc. gdol. du Nord, vol. 4, pt. 2,1897. Several incomplete analyses of gaize are given. The determination of amorphous silica by its solubility in caustic alkalies, it must be observed, is not very accurate. 

Silica in any form will dissove, the rate of solution depending upon the fineness of its subdivision and the 

concentration of the alkali. Opaline silica, however, dissolves rapidly in weak alkali, and so can be roughly 

estimated. Quartz dissolves very slowly.

2 See Griswold's monograph on this rock (Kept. Arkansas Geol. Survey, vol. 4,1890) and a paper by the 

same author in Proc. Boston Soc. Nat. Hist., vol. 26,1894, p. 414. Compare also 0. A. Derby, Jour. Geology, 

vol. 6,1898, p. 366; and J. C. Branner, idem, p. 368. Branner sums up very concisely the different theories 

which have been advanced to account for r.ocks of this character.

3 Quart. Jour. Geol. Soc., vol. 50,1894, p. 380.

* E. Hull and E. T. Hardman, Sci. Trans. Roy. Dublin Soc., new scr., vol. 1, 1878, pp. 71, 85, on the 

Carboniferous cherts of Ireland; A. Renard, Bull. Acad. roy. sci. Belgique, vol. 46, 1878, p. 471, on the 

phthanites of Belgium; T. Rupert Jones, Proc. Geol. Assoc. London, vol. 4,1876, p. 439; and others.
SEDIMENTARY AND DETRITAL ROCKS. 541

theory. That the replacement of calcium carbonate by silica is 

possible, no one can deny, for silicified shells and corals are common. 

The pseudornorphs of chalcedony or opal after coral, from Tampa 

Bay, Florida, are conspicuous examples of this change. Furthermore, 

A. H. Church * has effected the transformation artificially. A piece 

of recent coral was almost completely silicified, losing nearly all its 

carbonate of lime, when an aqueous solution of silica was allowed to 

filter through it very gradually. Some chert, then, may have been 

formed in this way. According to F. M. Van Tuyl 2 the cherts of 

Missouri probably originated in this manner, colloidal silica having 

been deposited on the bed of the sea while the limestone to be silicified 

was in process of formation. W. A. Tarr,3 however, and also R. -S. 

Dean 4 argue that the siliceous gel was thrown down from its suspension in sea water by the action of electrolytes and afterward dehydrated and consolidated by pressure. When, however, the gel collected in open spaces, such as cracks, and not under pressure, it 

solidified in the powdery form known as fripoli. One argument of 

much force, advanced by Van Tuyl against this hypothesis, is that 

silicified shells are common in the chert, and their condition can be 

ascribed only to a replacement of calcium carbonate'by silica.

On the other hand, chert and flint often exhibit evidences of organic 

derivation. The radiolarian cherts of California, described by A. C. 

Lawson, C. Palache, and F. L. Ransome,5 are principally composed 

of radiolarian remains. Lawson regards these cherts as having been 

formed by precipitations of colloidal silica from submarine springs, 

which produced a sort of ooze in which the radiolaria became embedded. In other cases cherts were probably derived from sponges, 

whose spicules consist very largely of opaline silica.0 Cherts crowded 

with these spicules have been described by various authors, especially by W. J. Sollas 7 and G. J. Hinde.8 Hinde studied especially 

the cherts of the Greensand formation in southern England, the 

cherts of Spitzbergen, and also the Irish cherts, described by Hull 

and Hardman. In all of them the sponge spicules were abundant. 

The same thing is true of the flint nodules found in chalk, which 

almost invariably show signs of a similar origin.9 In order to ac1 Jour. Chem. Soc., vol. 15,1862, p. 107.

a Am. Jour. Sci., 4th ser., vol. 45,1918, p. 449.

s Idem, vol. 44,1917, p. 409.

« Idem, vol. 45,1918, p. 411.

* Lawson, Fifteenth Ann. Kept. U. S. Geol. Survey, 1895, p. 420; Lawson and Palache, Bull. Dcpt. 

Geology Univ. California, vol. 2,1902, pp. 354,365; Ransome, idem, vol. 1,1894, p. 193. A recent exhaustive 

paper on these cherts is by E. F. Davis, Univ. of California, Bull. Dept. Geology, vol. 11,1918, p. 235.

s See Thoulet, Bull. Soc. min., vol. 7,1884, p. 147.

i Ann. and Mag. Nat. Hist., 5th ser., vol. 6,1880, pp. 384, 437; vol. 7,1881, p. 141.

8 Philos. Trans,, vol. 176,1885, p. 403; Geol. Mag., 1887, p. 435; idem, 1888, p. 241.

»See Hinde and Sollas, loc. cit., and G. C. Wallich, Quart. Jour. Geol. Soc., vol. 36,1880, p. 68. J. A. 

Merrill (Bull. Mus. Comp. Zoo]., vol. 28, 1895, p. 1) has described fossil sponges from flints found in tho 

Cretaceous near Austin, Tex.
542 DATA OF GEOCHEMISTRY.

count for these nodules, Sollas suggests that sponge spicules accumulated in a calcareous ooze, where, in presence of sea water under 

pressure, they partly dissolved. The silica thus taken into solution 

was later reprecipitated around suitable nuclei, at the same time 

replacing carbonate of lime. It is possible, however, as A. A. Julien1 

has shown, that the organic matter of the decaying sponges may 

have exerted much influence in bringing about the solution of silica. 

It is difficult to see how the nodules could have developed except 

from silica which had been first dissolved. Their growth around 

organic nuclei can hardly be explained otherwise.

Sedimentary rocks .consisting almost entirely of silica may originate in divers ways. As siliceous sinter 2 the silica is simply a 

deposit from hot springs. As sandstone it is an aggregate of finely 

divided quartz. In gaize and some cherts the rock is composed in 

great part of organic remains. In some cases calcium carbonate has 

been obviously replaced by silica. There are also siliceous concretion-like flints, as well as the oolites which are formed by the deposition of silica from solution around quartz grains. Such an oolite 

from Pennsylvania has been studied by several investigators.3 It is 

possible that a single formation may represent more than one of 

these processes. R. D. Irving and C. R. Van Hise,4 for example, 

describing the chert of the Penokee iron region, which was laid down 

simultaneously with the iron carbonates, suggest that it may have 

been partly derived from organic remains and also be partly a chemical sediment. In short, no one process can account for all the 

occurrences of amorphous or cryptocrystalline silica, and each locality must be studied in the light of its own evidence.

The following analyses of chert, novaculite, etc., will serve to 

illustrate the chemical-uniformity of these rocks: 5

1 Proc. Am. Assoc. Adv. Sci., 1879, p. 396.

»See ante, p. 200.

« E. H. Barbour and J. Torrey, Am. Jour. Sci., 3d ser., vol. 40,1890, p. 246; E. O. Hovey, Bull. Geol. Soc. 

America, vol. 5,1893, p. 627; and Bergt, AKhandl. Gcsell. Isis, 1892, p. 115. See also G. E. Wieland, Am. 

Jour. Sci., 4th ser., vol. 4,1897, p. 262, who ascribes these oolites to the agency of hot springs. E. S. Moore 

(Jour. Geologyt vol. 20, p. 259,1912). has also studied these minerals.

* Tenth Ann. Kept. TJ. S. Geol. Survey, pt. 1,1890, p. 397. See also C. R. Van Hise, A treatise on metamorphism: Hon. U. S. Geol. Survey, vol. 47,1904, pp. 847-853.

& For other analyses see Griswold's monograph on novaculite, Hardman's paper on the Irish cherts, Barbour and Torrey on the oolite, and Hovey (Am. Jour. Sci., 3d ser., vol. 48,, 1894, p. 401) on cherts from Missouri. In a large number of cherts from Kentucky, J. H. Kastle, J. C. W. Frazer,. and G. Sullivan (Am. 

Chem. Jour., vol. 20, 1898, p. 153) found appreciable amounts of phosphates ranging, from 0.18 up to 3.5 

per cent of PiO».
SEDIMEHTAEY AND JDETEITAL EOCKS. 543

Analyses of chert and allied rocks.

A. Novaculite, Eockport, Arkansas.. Analysis by R. N. Brackctt. From Griswold's monograph, p. 167.

B. Chert, Belleville, Missouri. Analysis by E. A. Schneidcr, Bull. IT. S. Geol. Survey No. 228,1904, 

p. 297. Other analyses are given on the same page.

C. Chert from tho Upper Carboniferous of Ireland. Analysis by E. T. Hardman, Sci. Trans. Roy. Dublin Soc., now ser., vol. 1, 1878, p. 85. Some of the Irish cherts are highly calcareous, representing transitions 

to siliceous limestone.

D. Siliceous oolite, Center County, Pennsylvania. Analysis by Bergt, Abhandl. Gesell. Isis, 1892, p. 115.

E. Infusorial earth, Nevada. Analysis by R. W. Woodward, Kept. TJ. S. Cool. Expl. 40th Par., vol. 2, 

1877, p. 768.

Si02 . ......................'..........

A1203 -.- ................................

Fe2 03 . ...............................

Feb

CaO............... ....................

CaCO.............. ....................

CaS04 .............. ..................

MgO.................................

K20...... ......... ....................

Na2 0....... ...........:..... ..........

P O.

Ignition ..............................

A

99.47

.17

.12

,09

.05

.07

.15

.12

100. 24

B

98.17

} .83

.05

.01

.78

99.84

O

95. 50

.10

1.95

.15

.87

Traro

Trace.

Trace.

1.43

100. 00

D

98.72 \ .«

.09

} .26

.34

99.95

E

86.70

4.09

1 9fi

.14

.51

.41

.77

Trace.

5.99

99.87

Other analyses, in considerable number, show intermediate gradations between chert and limestone. These represent comminglings 

in any proportion between the cherty silica and calcium carbonate. 

That is, silica and calcium carbonate may be deposited together in 

the same mud or ooze, forming a nearly homogeneous mixture.

SHALE AND SLATE.

When the finest products of sedimentation consolidate, they tend to 

form a close-grained, laminated, or fissile rock, which is called shale. 

As thus used, the term is very vague and has little chemical significance. 

Sand, reduced to the fineness of flour, may form a rock which is shaly 

in structure, and so too may limestone. In these cases, however, 

there is commonly more or less argillaceous impurity in the rocks, so 

that it is better to call them argillaceous sandstones or limestones.

As the term is generally used, a shale is supposed to be a consolidated mud or clay in which the aluminous silicates are the more 

-important and characteristic constituents. Shales, therefore, vary in 

composition exactly as do the materials from which they form, and 

may contain sandy or calcareous impurities. Bituminous and carbonaceous shales are also common. Many shales contain pyrite or 

marcasite, which oxidize and give rise to the formation of sulphates. 

These rocks are called alum shales and exhibit aluminous efflorescences. The alum shales and calcareous shales are easily alterable; 

those which consist chiefly of aluminous silicates, having been formed 

from the final products of rock decomposition, are remarkably stable. 

Their disintegration, when it occurs, is largely a mechanical process 

and involves very little chemical change.

Between typical sandstones and typical shales there are pronounced 

structural differences. A sandstone is made up of grains which are
544 DATA OF GEOCHEMISTRY.

discernible to the eye, and is therefore distinctly porous. In consequence of this peculiarity it is easily permeable to percolating waters, 

the source from which its cementing substances are derived. A shale, 

on the other hand, consists of much finer particles, which are closely 

packed, and its porosity is small.1 In its formation the cementing 

process is less prominent than in the case of sandstone, and its consolidation seems to have been effected by a sort of welding. The 

colloidal matter contained in most muds and clays is capable of 

binding under the influence of pressure alone; and to unions of this 

kind a shale mainly owes its coherence. Cementation is not excluded, 

but it has become a subordinate factor. Under the influence of 

pressure, the water of a mud is largely expelled, so that the resulting 

shale is much less hydrous.

The following analyses of shales were all made in the laboratory of 

the United States Geological Survey. Some constituents, reported 

in "traces" only, are omitted from the table. A number of other 

analyses are given in Bulletin 591, pages 250-258.

Analyses of shales.

A. Composite analysis of fifty-one Paleozoic shales, by H. N. Stokes. 

B. Composite analysis of twenty-seven Mesozoic and Cenozoic shales, by H. N. Stokes. 

C. Black Devonian shale, near Longfellow mine, Morenci district, Arizona. Analyzed by AY. F. 

Hillebrand.

D. Middle Cambrian shale, Coosa Valley, Alabama. Analysis by Stokes. 

E. Bituminous shale, Dry Gap, Georgia. Analysis by L. G. Eakins. 

F. Shale, near Rush Creek, Pueblo quadrangle, Colorado. Analysis by George Steiger. 

G. Carboniferous shale, Elliott County, Kentucky. Analysis by T. M. Chatard. 

H. Cretaceous shale, Mount Diablo, California. Highly calcareous. Analysis by Vf. n. Melville.

Si<X. ........ ......

TiO"2 .. ..............

A1208 ...... .........

Fea08 -- ----------

FpO

MnO..............

ZnO.......... ......

CaO. ...............

BaO. ...............

MgO..... ...........

Na20... ............

K,0. ..............

Li20.. ..............

HaO .............

H20+. ............

P205 .. .............. cb2 !. .............

so...... ...........

S.?.. ..............

c......... ..........

Chalcopyrite.. .

A

 60.15

.76

16.45

4 04

2.90

i.41

.04

o 09

1.01

3.60

RQ

3.82

i ^

1.46

.58

.88

100. 46

B

55.43

.46

13.84

4.00

1.74

5.96

.06

9 fi7

1.80

9 fi7

TfclCG

9 n

Q AX

9ft

4 fi9

.78

fiQ

100. 48

C

61.25

.66

15.50

1.35

3.04

.07

.03

3.40

4.16

.44

6.74

Trace

fi?

9 flQ

no

.25

.03

99.81

D'

55.02

.65

91 09

5.00

1.54

Trace.

1.60

.04

9 39

.81

3.19

03

9 44

5

CC

.06

o.83

.02

«. 32

100. 54

E

51. 03

13. 47

8.06

.78

1.15

.41

3.16

1 81 / " 81

31

7.29

13.11

3.32

&102. 90

F

45.89

KO

"13 94

3.88

19 OQ

9 19

.47

2.31

1.38

4.16

.17

10.38

3.47

100. 08

G

41.32

.48

9ft 71

2.59

5.46

.17

9.91

l 11

7.19

.88

8.78

.08

.55

100. 03

H

OK f\r.

8.28

97

9 41

4.11

27.87

9 fil

1.44

2.86

AQ

94 90

99.18

a Carbonaceous matter. & Less O=S, 100.17.

i For data on the fineness of sand and mud particles, see C. R. Van Hise, A treatise on metamorphism: 

Mon. U. S. Geol. Survey, vol. 47,1904, p. 892.
SEDIMENTARY AND DETEITAL ROCKS. 545

The most noticeable feature in these analyses, as compared with 

analyses of similar clays, is the change in the iron oxides. In the 

shales the proportion of ferrous relatively to ferric oxide has increased; 

probably because of the reducing action-of organic matter in the 

sediments as they were first laid down. Ferric oxide has been evidently reduced, and organic substances furnish the most obvious 

reagents for producing such an alteration.

Under the long-continued influence of pressure the shales become 

more compact and less hydrous, and pass into the rocks known as 

clay slates. By further change, of a metasomatic character, the 

slates are transformed into the metamorphic mica schists, in which 

various new minerals appear. The schists will be considered in the 

next chapter. Even in the slates the effects of metasomatism are 

manifest, for micas and chlorites appear conspicuously in them. 

These minerals have been formed at the expense of the clay silicate 

and the residual feldspars. Scales of detrital mica are, of course, 

common in the sediments; but in the slates the feldspar grains have 

been more or less transformed into particles made up of interlocking 

quartz and mica; the latter usually appearing .in the fibrous sericitic 

form. Even in Carboniferous clays and shales W. M. Hutchins 1 

found little kaolin, but more or less secondary quartz, chlorite, and 

mica. The chlorites, evidently, were derived from the d6bris of 

ferromagnesian minerals.

The mineralogical composition of the clay slates has been studied 

by several investigators, 2 and the results are thoroughly summed up 

by Dale in his memoir upon the slate belt of eastern New York and 

western Vermont. In these rocks he observed clastic particles of 

quartz, feldspar, zircon, muscovite, and carbonaceous matter; and 

autogenous quartz, chlorite, muscovite, pyrite, and carbonates of 

lime, magnesia, iron, and manganese. Rutile, hematite, and tourmaline were also noted. The pyrite was often altered to limonite. 

Other observers, studying other slates, have found ottrehte, staurolite, garnet, biotite, hornblende, epidote, apatite, pyrrhotite, gypsum, 

and magnetite in them.

The subjoined analyses of roofing slates were all made by W. F. 

Hillebrand in the laboratory of the United States Geological Survey.3

' Gcol. Mag., 1894, pp. 36, 64; idem, 1896, pp. 309, 343.

s See especially W. M. Hutchins, loc. cit.; H. C. Sorby, Quart. Jour. Geol. Soc., vol. 36, Proc., 1880, pp. 

66-80; and F. A. Anger, Jahrb. K.-k. geol. Reichsanstalt, Min. Mitt., vol. 25, 1875, p. 162. T. N. Dale 

(Nineteenth Ann. Rept. U. S. Geol. Survey, pt. 3,1899, pp. 153-307; also Bull. 275,1906) has made a special 

study of the roofing slates. His bulletin contains a report by W. F. Hillebrand on the composition of the 

slates, and closes with a valuable bibliography.

»See Dale, loc. cit., who cites other analyses. Still others are given in Bull. U. S. Geol. Survey No. 228, 

1904, pp. 337-346. J. Roth (Allgemeine und chemische Geologic, vol. 2, p. 588) tabulates 15 analyses of 

European clays and shales, and H. Rosenbusch (Elemente der Gesteinslchre, 2d ed., p. 442) gives a table 

of 39. See also E. C. Eckel, Jour. Geology, vol. 12,1904, p. 25, for the average composition of 36 American 

roofing slates.

113750° 10 Bull. 695 35
546- DATA OF GEOCHEMISTRY.

Analyses of .roofing slates.. .. .. . . ;

,-A."-Sea-green slate,°Pawlct, Vermont. B. Purple slate, Castleton, Vermont. C.-Black slate, Benson,, 

Vermont. D. Bod slate, near Hampton Village, New York. E. Green-slate, near Janesville, New-York, 

F. Black slate, Slatington, Pennsylvania.

'

ffi02 . ....................... AI n

Fe203 ---------. -------------

FeO.........................

MgO ........................

CaO. .........................

Na20..... ....................

KaO..... ....................

H20 ...................... 1

E20+ .......................

Ti02 . ........................

C02 . .......................

P O

MTnO..... ...................

BaO... .....................

FeS2 . .......................

NH8 . .......................

c. ..........................

A

67.76

14.12

.81

4.71

2.38

.63

1.39

3.52

.23

2,98

.71

.40

.07

.10

.04

22

None.

100. 07

B

60.96

16.15

5.16

2,54

3.06

.71

1.50

5.01

.17

3.08

.86

.68

.23

.07

.04

None.

.01

100. 23

C

59.70

16.98

KO

4.88

3.23

1 97

1 <**»

3 77

.30

3.82

.79

1.40

.16

.16

.08

1.18

.46

100. 05

D

67.61

13.20

5.36

1.20

3.20

.11

.67

4.45

.45

2.97

.56

TSTnno

.05

.10

.04

.03

100. 00

E

'ifi 4Q

11.59

3.48

1 49

fi 43

5.11

.52

3 77

.37

2.82

.48

7.42

no

.30

.06

.03

100. 38

F

56.38

15. 27

1.67

3.23

2.84

4 93

1 30

o t;i

.77

4.09

.78

3.67

17

.09

.08

1 72

.59

100. 39

LIMESTONE.

The carbonate rocks, which may be either sedimentary, detrital, or 

metamorphic, are represented principally by limestone and dolomite. 

Limestone consists of calcium carbonate more or less impure, and it 

occurs in many forms of very diverse origin. Some limestone, the 

variety known as calcareous tufa or travertine, is a chemical precipitate, but in its larger masses the rock is generally of organic origin. 

Chalk is probably derived from a marine ooze; other limestones are 

made up of shells and corals. In some the organic remains are 

conspicuous; in many cases they are quite obliterated. Sandy, 

argillaceous, glauconitic, ferruginous, phosphatic, and bituminous 

limestones owe their names to their manifest impurities. Even 

gaseous inclusions may give a limestone its name, as in the case of 

the fetid limestones or "stinkstones" of certain well-known localities. 

This peculiarity is well shown by a bed of caloite in Chatham Township, Canada, described by B. J. Harrington, 1 which contains 0.016 

per cent of hydrogen sulphide. A cubic foot of the rock contains 

about 500 cubic inches of the inclosed gas, to which its offensive 

odor, when struck or bruised, is due.

The primary source of limestone is obviously to be found in the 

decomposition of igneous rocks by carbonated waters. Calcium 

carbonate is thus produced; it passes into solution in ground water,

1 Am. Jour. Sci., 4th scr., vol. 19,1905, p. 315.
SEDIMENTARY AND DETRITAL ROCKS. 547

springs, and streams, and is thence withdrawn by a variety of processes. Its deposition as a chemical sediment, especially from hot 

springs, and even from sea water, was considered in a previous chapter, 1 but the evidence may well be repeated here and developed a 

little more fully. Much of the dissolved carbonate is precipitated 

as a cement in other rocks, but that point needs no further examination now.

When waters charged with calcium carbonate are allowed to evaporate, they deposit their load in the form of sinter, or tufa. This 

process can be observed at many thermal and "petrifying" springs, 

and also in the formation of stalactites and stalagmites in limestone 

caverns. In this way large masses of compact carbonate may be 

formed, which are oftentimes of great beauty. The so-called '' onyx 

marbles," of which the Mexican "onyx" is a familiar example, are 

formed in this way. Some rook of this class is stalagmitio, from 

caverns, and some of it is formed by springs.2 Its variations in color 

and texture, to which its ornamental character is largely due, are 

commonly produced by impurities or inclusions, such as oxide of 

iron, or even mud and clay.3

When fresh waters, charged with carbonates, enter the sea, a direct 

precipitation of calcium carbonate may occur. It happens only 

when the supply of carbonate is in excess of that which can be consumed by living organisms and when the conditions of temperature 

and evaporation are such as to expel the solvent carbon dioxide. 

By this is meant the carbon dioxide required to hold the carbonate 

in solution as bicarbonate. These conditions are found, according 

to Lyell,4 in the delta of the Rhone. This mode of precipitation is 

not in conflict with the recent careful investigations of J. Johnston 

and E. D. Williamson,5 who have shown that calcium carbonate is 

deposited from sea water by changes of temperature and of the concentration of atmospheric carbon dioxide, the surface layers of the 

ocean being usually saturated with respect to the carbonate. It is 

evident that any large influx of an ordinary river water would add 

calcium carbonate to the surface of the sea and so tend to supersaturate it a condition which must often occur locally.

Chemically precipitated calcium carbonate has been recognized 

by S. Sanford and. also by T. W. Vaughan, 6 along the coast of Florida. 

Here, however, G. H. Drew 7 has shown that bacteria are responsible

1 See ante, p. 19S. Analyses of tufa and travertine are there given.

2 For a general account of the onyx marbles see G. P. Merrill, Kept. U.S.Nat. Mus.,1893, p. 541. A good 

table of analyses is given in this memoir. The onyx marbles are usually calcito, rarely aragonite.

a On the solubility of calcium carbonate and other carbonates of the series RCOa in pure and carbonated 

water, see J. von Essen, Thesis, Univ. Geneva, 1907.

< Principles of geology, 12th ed., vol. 1,1S75, p. 426.

< Jour. Geology, vol. 24,1910, p. 729.

« See S. Sanford, Second Ann. Kept. Florida Gcol. Survey, 1908-9, pp. 224-225,228. Also T. W. Vaughan, 

Pub. 133, Carnogio Inst. Washington, 1910, pp. 114, 168 ct seq.

' Carnegie Inst. Washington, Pub. 182, 1914. See also K. I'. Kcllennan and N. U. Smith, Jour. Washington Acad. Sci.. vol. 4, p. 400,1914.
548 DATA OF GEOCHEMISTRY.

for a great part of the precipitation? - These organisms are enormously' 

abundant, and their metabolism generates ammonium carbonate 

which serves as the precipitant. This is a different process from that 

described above.

At Pyramid and Winnemucca lakes, in Nevada, great masses of 

calcareous tufa are formed, and sometimes, according to I. C. Russell, 1 the deposit takes the shape of oolitic sand. In the latter instance 

the precipated carbonate is deposited around nuclei, which may be 

grains of sand or other foreign bodies. Similar formations occur 

around Great Salt Lake, but only, as G. K. Gilbert 2 reports, where 

there is much agitation of the waves. The tufa is not formed in 

sheltered bays, but where there is surf the overcharge of carbon dioxide is easily driven out of the water, and calcium carbonate is precipitated. Oolitic sand is also found at Great Salt Lake, and in this 

case its deposition has been traced by A. Rothpletz 3 to the action of 

minute algse. This mode of formation needs to be considered further.

In 1864 Ferdinand Cohn 4 studied the formation of travertine at 

the waterfalls of Tivoli. He found there that many aquatic plants, 

especially species of Chara, mosses, and algse, became incrusted with 

calcium carbonate a fact which he attributed to their activity in 

absorbing carbon dioxide and so setting the carbonate free; that is, 

plants consume carbon dioxide and exhale oxygen. When they do 

this in water containing calcium bicarbonate, they deprive that salt 

of its second molecule of carbonic acid, and the insoluble neutral 

carbonate is thrown down. The sinter or travertine is thus formed 

primarily, but it is afterwards transformed into a compact mass by 

the deposition of calcite in its interstices; and in times of flood, when 

the waters are muddy, layers of sediment are laid down with it.

The same sort of plant activity has been repeatedly observed in 

connection with the marl deposits of certain fresh-water lakes. The 

term "marl," it must be noted, is very vague, and has been applied 

not only to earthy forms of calcium carbonate, but also to glauconitic 

sands containing no carbonate at all. Shell marl, as its name indicates, is largely made up of fragmentary shells; the marl here mentioned is of a different kind. As long ago as 1854 W. Kitchell 5 

pointed out that Chara took an active part in the production of fresh1 Mou. U. S. Geol. Survey, vol. 11,1885, pp. 61,189.

2 Mon. U. S. Geol. Survey, vol. 1,1890, p. 167.

a Am. Geologist, vol. 10,1892, p. 279. See also E. B. Wethered, Quart. Jour. Geol. Soc., vol. 51, 1895, 

p. 196, on oolite from other localities. Virlet d'Aoust (Compt. Rend., vol. 45,1857, p. 865), studying the 

formation of oolite in some Mexican lakes, argues that insect eggs, which are deposited in great numbers 

on the surface of the water, may act as nuclei.

4 Neus Jahrb., 1864, p. 580. An earlier paper by Cohn (18G2), on the Carlsbad "sprudelstein," I have 

not been able to see. It is often quoted. W. H. Weed (Ninth Ann. Kept. U. S. Geol. Survey, 18S9,p. 613, 

has shown that the travertine formed around the hot springs of the Yellowstone National Park is produced by the aid of algse.

6 First Ann. Rept. Geol. Survey New Jersey, 1855, p. 50. See also G. H. Cook, Geology of New Jersey, 

1868, p. 172.
 SEDIMENTARY-AN-D DETRITAL ROCKS. 549

water marl. In 1900 C. A. Davis x discussed the subject much more 

fully, with reference to some lakes in Michigan, and came to essentially the same conclusions as Cohn. Davis, however, regards the 

oxygen liberated by the aquatic plants, Chara, etc., as assisting 

in some way the precipitation of the carbonate; but his equation 

showing the supposed reaction rests on no experimental basis. The 

activity of plants in marl formation was also considered by W. S. 

Blatchley and G. H. Ashley 2 in their report on the lakes of Indiana, 

but these writers attach fully as much importance to inflowing, limebearing springs. The attention which these deposits have received 

is due to their value for fertilizing purposes. It is possible, as Mr. 

Bailey Willis has suggested to me, that some marine limestones have 

been formed by plant agencies. In the shallow seas which are 

thought to have covered a large part of the North American continent the calcium carbonate may well have been thrown down by algae. 

To produce a permanent deposit, however, the water must have been 

too warm to carry much carbonic acid in solution, and too shallow 

for the precipitate, while sinking, to redissolve.

Another process by which calcium carbonate may be precipitated 

was pointed out by G. Steinmann.3 He found that albumen, which 

is present in the organic parts of all aquatic animals, was a distinct 

precipitating agent. Apparently, by fermentation, the albuminoids 

generate ammonium carbonate, and to that compound the precipitation of calcium carbonate is due. This or any other alkaline carbonate, entering waters saturated with calcium carbonate, would bring 

about the separation of the last-named salt.

In studying the formation of shell limestone or coral rock, it is 

desirable to take account of the fact that calcium carbonate exists 

in at least two geologically important modifications calcite and 

aragonite. Calcite crystallizes in the rhornbohedral division of the 

hexagonal system, and has, when pure, a specific gravity between 

2.71 and 2.72. Aragonite is orthorhombic, and its specific gravity is 

near 2.94. Calcite is by far the more abundant form, and it is also 

the more stable. 4 Aragonite alters easily to paramorphs of calcite,

1 Jour. Geology, vol. 8,1900, pp. 485, 498; vol. 9,1901, p. 491.

2 Twenty-fifth Ann. Kept. Dept. Geology, etc., Indiana, 1900, pp. 31-322. The memoir contains analyses 

of marls by W. A. Noyes. See also a criticism by C. E. Siebenthal, Jour. Geology, vol. 9, 1901, p. 354. 

W. C. Kerr, in Geology of North Carolina, vol. 1, p. 187> gives many analyses of marl from that State. An 

elaborate report on marl, by D. J. Hale, and others, forms part 3 of volume 8, Michigan Geol. Survey, 1900.

» Ber. Naturforsch. Gesell. Freiburg, vol. 4,1889, p. 288.

« See the physicochemical researches of H. W. Foote (Zeitschr. physikal. Chemie, vol. 33,1900, p. 740), in 

which this point is developed quantitatively. Important modern papers on the relations between calcite, 

and aragonite are by H. Vater, Zeitschr. Kryst. Min., vol. 21, 1893, p. 433; vol. 22,1894, p. 209; vol. 24, 

1895, pp. 360, 378; vol. 27,1897, p. 477; and vol. 30,1899, pp. 295, 485. See also O. Mugge, Neues Jahrb., 

Beil. Band 14,1901, p. 246, and H. Leitmeier, Neues Jahrb., 1910, Band 1, p. 49. On the conditions under 

which calcite and aragonite are formed as chemical precipitates see W. Mcigen, Ber. Naturforsch. Gesell. 

Freiburg, vol. 13,1903, p. 40, and vol. 15, 1905, p. 38, and H. Warth, Centralbl. Min., Geol. u. Pal., 1902$ 

p. 492. According to W. Vaubel (Jour, prakt. Chem., ser. 2, vol. 86, 1912, p. 300), aragonite contains a 

small admixture of a hydrobasic carbonate.
550 DATA OF GEOCHEMISTRY.

but the reverse change rarely, if ever, occurs. The reported paramorphs of aragonite after calcite are of doubtful authenticity. According to P. N. Laschenko 1 aragonite when heated to 445° begins 

to change into calcite. The change is complete at 470°. A monoclinic variety of calcium carbonate, lublinite, has recently been described by R. Lang.2 E. Quercigh,3 however, has shown that it is 

merely calcite. Another crystalline modification since named vaterite; forming spherulitic aggregates, was first observed by H. Vater 

(loc. cit.), but it is not known to occur in nature. It was produced 

artificially.

In recent years two other varieties of calcium carbonate have been 

described as distinct from calcite and aragonito. The carbonate of 

some molluscan shells, which had been called aragonite, was made 

into a distinct species by Agnes Kelley,4 who named it conchite. The 

pisolite formed at the hot springs of Hamniain-Meskoutine, Algeria, 

was given specific rank by A. Lacroix,5 under the name ktypeite. 

Both of these alleged species have since been identified with aragonite 6 and need no further consideration here.

In a very thorough synthetic investigation J. Johnson, H. E. Merwin, and E. D. Williamson 7 have found that anhydrous calcium 

carbonate exists in only three forms, namely, calcite, aragonite, and 

an unstable modification, crystallizing in hexagonal plates, which is 

not known to occur as a natural mineral. The other alleged modifir 

cations mentioned above have no existence as distinct species. 

 Calcite and aragonite may be distinguished from each other, when 

not distinctly crystallized, either by their differences in specific 

gravity or in their optical properties. There are also two chemical 

tests discovered by W. Meigen.8 When aragonite is immersed in a 

dilute solution of cobalt nitrate, it is colored lilac, and the color persists on boiling. Calcite, under like treatment, remains white in the 

cold, but becomes blue on long boiling. Again, calcite, in a solution 

of ferrous sulphate, produces a yellow precipitate of ferric hydroxide;

1 Chem. Abstracts, vol. G, 1912, p. 464. From a Russian original.

- Neues Jahrb., Beil. Band 33, p. 121,1914. According to 0. Miigge (Centralbl. Man., Geol. u. Pal., 1914, 

p. 673), lublinite is merely a pseudomorph and not a species. For a reply by Lang, see idem, 1915, p. 298. 

3 Rivista min. crist. Italia, vol. 14,191C, p. Go.

* Miueralog. Mag., vol. 12,1900, p. 363.

s Coinpt. Rend., vol. 120,1898, p. 602. For another description of this deposit see L. Duparc, Arch. sci. 

phys. nat., 3d ser., vol. 20,18SS, p. 537.

6 On conchite, see R. Brauns, Centralbl. Min., Geol. u. Pal., 1901, p. 134. II. Vater (Zeiischr. Kryst. 

Min., vol. 35,1902, p. 149), examined both conchite and ktypeite. Vater also describes the Carlsbad " sprudelstein," which is aragonite.

i Am. Jour. Sci., 4th ser., vol. 41,191G, p. 473.

8Centralbl. Min., Geol. u. Pal., 1901, p. 577; Ber. Oborrhoin. geol. Verein, 1902, p. 31; Ber. Naturforsch. 

Gesell. Freiburg, vol. 15,1905, p. 55. See also A. Hutchinson, Mineralog. Mag., vol. 13, Proc., l£03^p. 

xxviii; G. Wyrouboir, Bull. Soc. min., vol. 24,1901, p. 371; and S. Krcutz, Min. pet. Mitt., vol. 28,1909, 

p. 487. S. J. Thugutt (Centralbl. Min., Geol. u.'Pal., 1910, p. 786) describes color discriminations based 

upon the use of organic dyes. See also Vaubel (loc. cit.), and K. Niederstadt, Zeitschr. angew. Chemio, 

vol. 25,1912, p. 1219. According to G. Panebi'anco (abstract in Zeitschr. Kryst. Min., vol. 40,1905, p. 288), 

the "hydroxides" of Meigen's reaction are really carbonates. On the ferrous-sulphate test see also W. 

Diesel, Zeitschr. Kryst. Min., vol. 49, p. 250, ion. See also Johnston, H'envin, and Williamson, loc. cit.
SEDIMENTARY AND DETRITAL ROCKS. 551

while aragonite gives a dark-greenish precipitate of ferrous hydroxide. These tests were applied by Meigen to a large number of'shells 

and corals, both recent and fossil, and the mineralogical character of 

each species was determined. A list of the determinations is given 

hrhis memoir.

The importance of discriminating between calcite and aragonite 

was pointed out very clearly by H. C. Sorby, 1 in his address upon 

the origin of limestones. He too, much earlier than Meigen, gave 

data concerning the calcareous parts of different classes of animals, 

and showed that shells composed of aragonite rarely appeared as 

fossils. The same subject was also discussed by V. Cornish and 

P. F. Kendall 2 on the basis of experiments in which they found that 

carbonated waters decompose and disintegrate aragonite shells much 

more readily than shells formed of calcite. The difference, however, 

is attributed to structure rather than to mineralogical distinctions. 

But be that as it may, while calcite organisms remain permanently 

in fossil form, aragonite shells largely disappear. Onty the larger, 

denser, heavier aragonite structures seem to be preserved to any 

considerable extent. Kendall 3 has applied these observations to the 

study of oceanic oozes. The pteropod shells, being mainly aragonite, 

disappear below 1,500 fathoms depth, while the calcitic globigerina 

is found in ooze at 2,925 fathoms. From the fact that the Upper 

Chalk of England contains only calcite organisms, Kendall 4 infers 

that it was deposited at a depth of at least 1,500 fathoms. Attempts 

have been made to identify chalk with the globigerina ooze, but L. 

Cayeux 5 has shown that the two substances are markedly different. 

Chalk, however, is composed of organic remains, largely foraminiferal, and undoubtedly represents an ooze of some kind. 0 It also 

contains detrital impurities, and in chalk from northern France 

Cayeux 7 has identified microscopic particles of quartz, zircon, tourmaline, rutile, magnetite, muscovite, orthoclase, plagioclase, anatase, 

brookite, chlorite, staurolite, garnet, apatite, ilmenite, and corundum. 

These impurities exist in very small proportions, and for practical 

purposes chalk may be regarded as nearly pure carbonate of lime in 

exceedingly fine subdivision.

In his study of the oolites G. Linck 8 has shown that all recent 

deposits, so far as he was able to examine them, were composed of

1 Quart. Jour. Soc., vol. 35, Proc., 1879, p. 56.

» Geol. Mag., 188S, p. CO. See also P. Tesch, Proc. Sec. Sci., Amsterdam Acad., vol. 11,190S, p. 236; A. 

R. Honvood, Geol. Mag., 1910, p. 173; and G. A. J. Cole and O. H. Little, idem, 1911, p. 49.

3 Eept. Brit. Assoc. Adv. Sci., 1896, p. 789.

4 Idem, 1896, p. 791.

' > Mt5m. Soc. ge"ol. du Nord, vol. 4, pt. 1897, p. 518.

n See C. Wyville Thompson, Depths of the sea, London, 1874, pp. 467,501.

'Op. cit.,p. 257.

.. s Neues Jahrb., Beil. Band, 16 p. 495. Linck gives a good summary of previous literature upon oolite. 

See also II. Fischor, Monatsh. Deutsch. geol. Gesell., 1910, p. 247. See also T: C. Brown, Bull. Geol. Soc. 

America, vol.25,1914, p. 745, P. M. Van Tuyl, Jour. Geology, vol. 24,191G, p. 702, and W. H. Bucher, Jour. 

Geology, vol.'20,191S, p. 503.
552 DATA OF GEOCHEMISTRY.

aragonite, while the-older "fossil" occurrences were calcite that is, 

according to his observations, oolite forms as aragonite and slowly 

changes to the more stable calcite. By experimenting directly with 

sea water it was found that precipitation with sodium or ammonium 

carbonate produced aragonite, as determined by Meigen's reaction 

with cobalt nitrate. When solutions of calcium bicarbonate alone ^ 

were allowed to evaporate, Linck further found that at ordinary 

atmospheric temperature calcite was deposited, but that at 60° aragon- i 

ite was formed. In sea water, then, the separation of calcium carbonate in one modification or the other is conditional upon the proc- ^ 

ess of precipitation and probably also upon climate. Where organic 

decay is prominent, the ammonium carbonate produced thereby may 

act as precipitant, and that is more likely to be the case in warm 

climates than in cold. The direct deposition of calcium carbonate 

is commonly in the calcite form, because the temperature of oceanic 

water is usually low. The two minerals in certain cases may be ^ 

formed together, and this actually happens in the growth of some 

shells. A shell may consist of a principal mass of calcite, coated by 

a pearly layer of aragonite, and other associations of the two species 

in a single animal are well known. In the fossilization of such a 

shell the aragonite portion is commonly destroyed, while the calcitic 

layer or fragment is preserved.

In what manner do plants and animals withdraw or segregate 

calcium carbonate from sea water ? To this question there have been >" 

many answers proposed,1 but the problem is essentially physiological, 

and its full discussion would be inappropriate here. Some of the 

answers, however, were framed before the modern theory of solutions 

had been developed, and are therefore no longer relevant. It is not 

necessary to ask whether the living organisms derive their calcareous 

portions from the sulphate or chloride of calcium or absorb the car- >- 

bonate directly, for these salts are largely ionized in sea water. It 

is only essential that calcium ions and carbonic ions shall be simultaneously present; then the materials for coral and shell building 

are at hand. The carbonic ions may be of atmospheric origin, or 

brought to the sea by streams, or developed by the physiological 

processes of marine animals, or a product of organic decay; all of < 

these sources contribute to the one end and help to supply the material from which limestones are made. Where marine life is abundant, there also the carbonic ions abound. This fact is strikingly 

shown by W. L. Carpenter's analyses 2 of the gases extracted from 

sea water and their correlation with the results obtained by dredging. 

In one series of three samples from different depths, but at the same r 

locality, the gases were composed as follows:

1 See R. Brauns, Chemische Mineralogie, pp. 377-378, for a summary of this subject.

2 In C. Wyville Thomson's .Depths of the Sea, London, 1874, pp. 502-511. On p. 513 is given a table of 

analyses of sea water by Frankland, in which the presence of abundant organic matter is shown.
SEDIMENTARY AND DETRITAL ROCKS. 553

Gases extracted from sea water collected at different depths.

oa ... ......................................

N2 . .......................................

coa ... ....................................

802 fathoms 

(bottom).

17.22

CM CA

48.28

100. 00

800 fathoms.

17.79

48.46

33.75

100. 00

750 fathoms.

18.76

4Q QO

31 Q9

100. 00

On the bottom, where the proportion of C02 was highest, animal 

life was abundant, and the dredge brought up a rich haul. At 

another point, where the C02 at the sea bottom fell to 7.93 per cent, 

the dredge made a very bad haul. In short, from the composition 

of the dissolved gases, it was possible to assert whether living forms 

were scarce or plentiful upon a particular point of the ocean floor.

The most obvious occurrence of limestone building from shells is 

that which may be observed on many sea beaches. The coquina of 

Florida is a familiar example of this kind. Masses of shell fragments are there compacted together, cemented by calcium carbonate 

which has been deposited from solution between the bits of shell, and 

a fairly substantial rock, available for building purposes, is produced. 

Some quartz sand is commingled with the shell material, and at one 

locality, noted by W. H. Dall,1 limonite, deposited by a chalybeate 

spring, serves as the cementing substance.

In the Bay of Naples, according to J. Walther,2 calcareous alga?, 

especially of the genus Lithotliamnium, are conspicuous makers of 

limestone; and similar observations have been made elsewhere by 

others. LifhotJiamnium is a seaweed whose framework or skeleton 

consists of calcite; another genus, Halimeda, which is also active in 

limestone making, contains aragonite. In recent years the geologic 

significance of these algre has become generally recognized.3

From a genetic point of view the coralline limestones have probably 

been the limestones most carefully studied. Their formation around 

coral islands and in coral reefs can be observed with the greatest 

ease, and the process may be followed step by step. First, the 

living coral; then its dead fragments, broken into sand by the waves; 

then their cementation by solution and redeposition of calcium carbonate; and finally the solid rock, made up visibly of organic remains, 

may be seen. In such limestones, according to E. W. Skeats,4 both 

calcite and aragonite occur, directly deposited from the sea water. 

In composition, when recent, they are like the coral itself, nearly

1 Am. Jour. Sci., 3d ser., vol. 34,1887, p. 163. 

a Zeitschr. Deutsch. geol. Gesell., vol. 37,1S85, p. 329.

3 E. J. Garwood (Geol. Mag., 1913, pp. 440,490,552) has pointed out the great geologic importance of the 

calcareous algse. 

« Bull. Mus. Comp. Zool., vol. 42,1903, pp. 53-120.
554 DATA OF- GEOCHEMISTRY. -

pure carbonate of lime,-but a little-organic matter is also-present, 

some earthy mutter,-and- very-sm&ll-quantities of calcium phosphate. 

In corals from the Gulf Stream S. P. Sharpies 1 found from 95.37 to 

98,07. per cent of .CaC03, and 0.28 to 0,84 of Ca3P208 . These results 

are concordant with those obtained by many other analysts,2 and 

need no further illustration just.now.. The alteration, of coral 

rock to dolomite will be considered later.

From what has been said in the preceding pages, it is evident 

that important limestones may be formed in various ways, which, 

however, are chemically the same. Calcium carbonate, withdrawn 

from fresh or salt water, is laid down under diverse conditions, 

yielding masses which resemble one another only in composition. 

An oceanic ooze may produce a soft, flourlike substance such as 

chalk, or a mixture of carbonate and sand, or one of carbonate and 

mud or clay. Calcium carbonate, transported as a silt, may solidify 

to a very smooth, fine-grained rock, while shells and corals yield a 

coarse structure, full of angular fragments and visible organic remains. 

Buried under other sediments, any of these rocks may be still further 

modified, the fossils becoming more or less obliterated, until in the 

extreme case of metamorphism a crystalline limestone is formed. 

All trace of organic origin has then vanished, a change which both 

heat and pressure have combined to bring about, aided perhaps by 

the traces of moisture from which few rocks are free. Several experimental investigations bear directly upon this class of transformations.

To illustrate the influence of pressure alone, we have an important 

experiment by W. Spring.3 A quantity of dry, white chalk, inclosed 

in a steel tube, was placed in a screw press under a pressure of 6,000 

to 7,000 atmospheres, and left there for a little over seventeen years. 

At the end of that time it had become hard and smooth, with a 

glazed surface, and was somewhat discolored by iron from the tube. 

It was also in part distinctly crystalline; in short, it resembled to 

some extent a crystalline limestone, although the change was not 

absolutely complete.

When heated above redness at ordinary pressures, limestone decomposes into carbon dioxide and lime. This is the common change 

produced in a limekiln. ' Under pressure, however, this dissociation 

is prevented and calciuni carbonate may be apparently fused.

1 Am. Jour. Sci., 3d ser., vol. 1,1871, p. 168.

2 Soo, for example, G. Forchhammer, Neues Jahrb., 1852, p. 85-1, and A. Liversidge, Proc. Roy. Soc.New 

South Wales, vol. 14,1880, p. 159, on coral from New Hebrides, and coral rock irom Duke of York Island. 

Also A. J. Jukes-Brown and J. B. Harrison, Quart. Tour. Geol. Soc., vol. 47,1891, p. 224, on coral rocks 

from Barbadoes. A number of analyses of coquina, coralline limestones, etc., are given in Bull. U. S. 

Geol. Survey No. 228,1904. Several analyses by H. W. Nichols appear in Pub. Ill, Field Columbian Mus., 

1906, p. 31. Several analyses of Brazilian corals by L. R. Lenox are in Bull. Mus. Comp. Zool., vol. 44, 

1904,p.264. More than thirty analyses of corals are given in Prof. Paper U.S. Geol. Survey No.102,1917. 

A monographic paper entitled Untersuchungen uober organische Kalkgebilde, by 0. Bijtschli is in 

Abhandl. 1C. Gesell. Wiss., Gb'ttingen, new series, vol. 6, No. 3, 1908. This paper is rich in references to 

literature.

3 Zeitschr. anorg. Cheniio, vol. 11,1896, p. 160.
SEDIMENTARY AND DETEITAL ROCKS. 555

Over a century ago Sir James Hall l heated limestone in closed 

vessels and obtained from it a product identical in general character 

with crystalline marble. Since Hall's time the experiment has been 

repeated by a number of other investigators, under varying conditions, with various degrees of success, and with quite dissimilar 

interpretations. It was supposed at first that Hall had fused limestone, and this belief was prevalent for many years. G. Rose, 2 

however, transformed a compact limestone into marble as Hall had 

done, but without evidence of fusion; and A. Becker,3 in a more 

extended research, found that by moderate heat and relatively slight 

pressure calcium carbonate could be converted into a finely granular 

mass. A fine powder of the carbonate even developed into larger 

grains of calcite without either fusing or softening.

In the experiments of H. Le Chatelier 4 an actual fusion of the 

carbonate was perhaps effected. The chemically precipitated carbonate was inclosed in a steel cylinder between two pistons, under a 

pressure of about 1,000 kilograms to the square centimeter. Heat 

was applied by an electric current passing through a spiral of platinum wire embedded in the mass, and the temperature attained was 

about 1,050°. Under these conditions the calcium carbonate near 

the spiral was fused to a translucent mass resembling some marbles. 

Between the fused and unfused portions there was a sharp demarcation, with no indication of any intermediate state. In his second 

paper Le Chatelier states that even at 1,020° and under slight or 

insignificant pressure calcium carbonate agglomerates to a crystalline mass. In similar experiments A. Joannis 5 was able to transform 

chalk into something like marble at a temperature above the melting point of gold and under a pressure of 15 atmospheres. Joannis 

suggests that the melting point of calcium carbonate may perhaps 

be lowered by pressure. H. E. Boeke,0 however, has obtained a 

true fusion of calcium carbonate at 1,289°, under a pressure of 110 

atmospheres.

From all of this evidence we may conclude that the change from 

apparently amorphous calcium carbonate to a distinctly crystalline 

limestone or marble may be effected by pressure alone, heat alone, or 

both together. Actual fusion may or may not occur; at all events

1 Trans. Roy. Soc. Edinburgh, vol. 6, 1812, p. 71. Tho experiments wero performed in 1805. For a 

summary of therosults obtained by Bucholz, Petzholdt, and Richthofcn, see J. Lembcrg, Zeitschr. Deutscli. 

geol. Gesell., vol. 24,1872, pp. 237-241. Lemborg criticizes the conclusions drawn from Hall's data, and 

expresses a strong doubt as to whether fusion actually occurred.

a Pogg. Annalen, vol. 118,1863, p. 565.

8 Min. pet. Mitt., vol. 7,1886, p. 122. Becker also gives a good summary of the earlier literature of tho 

subject.

« Compt. Rend., vol. 115,1892, pp. 817,1009. Two papers.

s Idom, vol. 115,1892, pp. 934,1236. Two papers.

8 Neues Jahrb., 1912, Band 1, p. 91. In another papor, Mitt. Naturforsch. Gosell. Hallo, vol. 3,1913, Booko 

has also determined the molting point of barium carbonate, 1,COO° under 90 atmospheres pressure, and 

strontium carbonate, 1,497° under 60 atmospheres.
556 DATA OF GEOCHEMISTRY.

it seems to be unnecessary. Furthermore, it is highly probable that 

water plays some part in bringing about the transformation, for in 

geological phenomena its influence is rarely excluded. If water did 

no more than to dissolve and .redeposit particles of carbonate, it 

would go far toward producing the observed change in structure. 

Under these conditions the carbonate would, in time, become a 

coarsely crystalline or granular mass of calcite.

The following analyses of limestones are all taken from the laboratory records of the United States Geological Survey. 1

Analyses of limestones.

A. Limestone, Lee, Massachusetts. Analysis by G. Steiger. 

B. Limestone, Silverdale, Kansas. Analysis by C. Catlett. 

C. Lithographic stone, Solenhofen, Bavaria. Analysis by Steiger. 

D. Oolitic sand, Great Salt Lake, Utah. Analysis by T. M. Chatard. 

E. Coquina, Key West, Florida. Analysis by F. W. Clarke. 

F. Recent coral (Siderastrca), Bermuda. Analysis by L. G. Eakins. 

G. Composite analysis, by H. N. Stokes, of 345 limestones.

H. Composite analysis, by Stokes, of 498 limestones used for building purposes. Does the high proportion of silica generally determine the availability of these rocks to structural ends? 

Ideally pure calcium carbonate contains 56.04 per cent of CaO and 43.96 of C02.

Si02 ...............

Ti02 .. ............. AI r>

FeA- ....... ------

FeO................

MnO...............

CaO.................

MgO......... ........

K20. ...............

Na20. ...............

Li2O. ..............

H20...............

H20+. .............

p n

C02 .. ..............

s. ..................

S08 ....... ..........

01..................

Organic .............

A

0.95

.09

Non6

.10

54. 75

.56

.15

.02

| -.08

.03

43.38

.05

100. 16

B

5.27

1.07

.71

.32

50.36

.56

.10

.20

| .78

.06

40.34

.07

99. 84

C

1.15

}

AK .:.! .

.26

53.80

.56

] .07

.23

.69

42.69

99.90

D

a4.03

1 .20

51.33

.72

. 63

1 .83

Trarp

41.07

.89

.27

99.97

E

0.25

| ..56

51.52

2.08

} 3.19

41.58

99.18

F

0.23

JTjace. '

55.16

.20

\ -54 r - b4

43.74

99.87

G

K 1Q

.06

01

y .54

.05

42. 61

7 Qft

qq

nc

Trarp

.21

&.'56

.04

41.58

QQ

.05

.02

100. 09

H

H ftQ

.08 i i*\

\ .77

.03

40.60

4 40

.58

fi9

Trarp

.30

6.88

.42

35.58

.07

.07

.01

100. 34

o Insoluble in hydrochloric acid. b Includes organic matter.

Limestones undergo alteration in several ways. They may be silicified by percolating waters, or phosphatized, as is often seen .on

1 See Bull. No. 228,1904, pp. 301-336, where 234 analyses of carbonate rocks are given. For other data 

see T. C. Hopkins, Ann. Kept. Arkansas Geol. Survey, vol. 4,1890; S. W. McCallie, Bull. Geol. Survey 

Georgia No. 1,1904. F. G. Clapp, Bull. U. S. Geol. Survey No. 249,1905, gives many analyses compiled 

from the geological reports of Pennsylvania. H. Ries and E. C. Eckel, Bull. New York State Mus. No. 44, 

1901; Ries, Fifty-first Ann. Rept. New York State Mus., pt. 2,1899, pp. 357-467; E. C. Eckel, Bull. U. S. 

Geol. Survey No. 243,1905, on cement materials; W. G. Miller, Rept. Bur. Mines (Ontario), pt. 2,1904; 

T. C. Hopkins and C. E. Siebenthal, Twenty-first Ann. Rept. Dept. Geology, etc., Indiana, 1896, pp. 293- 

427. On the evolution of limestones and the relation of their composition to geologic age see R. A.. Daly, 

Am Jour. Sci., 4th ser., vol. 23,1907, p. 93, and Bull. Geol. Soc. America, 1909, vol. 20, p. 153. :
SEDIMENTARY AND DETRITAL BOOKS. 557

guano islands.1 By oxidation of inclosed pyrite, acid sulphates can 

be formed, and these wril alter the limestone partially or entirely to 

gypsum. Acid waters dissolve limestone with evolution of carbon 

dioxide; and some effervescent springs may owe their sparkling 

qualities to reactions of this kind. A honeycombed limestone at the 

bottom of Lake Huron was possibly corroded by water of an acid type. 

R. Bell 2 found the water of the lake over the limestones to be distinctly 

acid, the acidity having been possibly derived from sulphides in 

Huronian rocks to the northward. By thermal metamorphism a limestone may be profoundly altered; but that class of changes is to be 

considered in another chapter. Byfar the most important alteration, 

however, is that produced by waters containing carbon dioxide, 

especially meteoric waters. These dissolve limestone, and the caverns 

formed in limestone regions are produced in this way. Great masses 

of limestone are thus removed, to be deposited, generally in a diffused 

form, elsewhere. At the same time, the insoluble residual-impurities 

are left behind, in the form of sand, clay, ores of manganese and iron, 

etc.3 Some analyses of such residual clays are given in the preceding 

chapters. These residues are very variable in composition, and rarely 

approximate to kaolin. This point was developed by H. Le Chatelier,4 who dissolved several calcareous marls in acetic acid, and 

analyzed the residual silicates. Kaolinite was not found in them; 

but hydrous silicates of aluminum, ill defined and impure, were generally obtained. In one sample from the French Congo, the residue 

was a silicate of magnesium. According to A. L. Ewing,5 the rate of 

limestone erosion in Spring Creek Valley, Center County, Pennsylvania, amounts to 275 tons per square mile per annum.6 This corresponds to a lowering of the land surface in that region of about 

one foot in nine thousand years.

DOLOMITE.

Ill the foregoing pages upon limestone, the magnesian varieties 

have been purposely left out of account. They represent transitions 

from calcium carbonate to dolomite, CaMg(C03 ) 2 , a rock of great 

importance both practically and theoretically, and one which demands separate consideration. In addition to dolomite, it is necessary also to consider magnesium carbonate itself, magnesite, and its

1 On thesilicification of limestones see F. Kuhlmann, Ann. Chem. Pharm., vol. 41,1842, p. 220; J. Lemberg, Zeitschr. Deutsch. geol. Gesell., vol. 28,1876, p. 562; and W. Clemm, Inaug. Diss. Freiburg, 1909. 

On the silicification of fossils, B. S. Bassler, Proc. U. S. Nat. Mus., vol. 35,1908, p. 133. On phosphatiza- 

.tion see R. Irvine and W. S. Anderson, Proc. Roy. Soc. Edinburgh, vol. 18,1891, p. 52; L. Gassner, Inaug. 

Diss. Freiburg, 1906, and references in the section on phosphate rock in the preceding chapter.

2 Bull. Geol. Soc. America, vol. 6,1894, p. 302.

»SeeI. C.Russell, Bull. U. S. Ceol. Survey No. 52,1889, for a discussion of this subject. Russell regards 

the Clinton iron ores of Alabama as residues of this kind, but his views on that matter-have been contested. 

< Compt. Rend., vol. 118,1894, p. 262. 

6 Am. Jour; Sci., 3d ser., vol. 29,1885, p. 29. 

6 Or 29.173 grams per square meter.
558 DATA OF GEOCHEMISTRY. <

hydrous derivatives, of which several are known. Like calcium carbonate, these species originate in very different ways, and some of 

the processes by which they form must be discussed in connection 

with the subject of serpentine later. Only the compounds of sedimentary or organic origin fall within the scope of this chapter.

The double carbonate, dolomite, can be produced artificially by 

several methods, and its accidental formation has also been observed. 

C. de Marignac 1 obtained it by heating calcium carbonate with a 

solution of magnesium chloride to 200°, under a pressure of 15 atmospheres. J. Durocher 2 heated fragments of porous limestone with 

dry magnesium chloride to dull redness in a closed gun barrel, in 

such manner that the carbonate was impregnated by the vapor of the 

chloride. Under those conditions the limestone was partly changed 

to dolomite. The local formation of dolomite by volcanic action is 

explained by this experiment, but that mode of occurrence is of 

minor import. C. Sainte-Claire Deville 3 saturated chalk with a 

solution of magnesium chloride and heated the mass upon a sand 

bath. A partial replacement of lime by magnesia was thus effected, 

and similar results were obtained with corals. A. von Morlot,4 by 

heating powdered calcite.with magnesium sulphate to 200° in a sealed 

tube, transformed the carbonate into a mixture of dolomite and gypsum. This reaction had been suggested by Haidinger, in order to 

account for the frequent association of the two last-named species. 

The process, however, is reversible, and solutions of gypsum will 

transform dolomite into calcium carbonate and magnesium sulphate. 

Efflorescences of the latter salt are not uncommon in gypsum quarries, and H. C. Sorby 5 has observed them in Permian limestones. 

Because of this reaction, according to Sorby, the upper beds of magnesian limestone are often more calcareous than the lower. Their 

content in magnesia has been diminished in this way.

The elaborate experiments of T. Sterry Hunt 6 upon the precipitation of calcium and magnesium carbonates, especially by alkaline 

carbonates from bicarbonate solutions, are too complex to admit of 

anything like a full summary here. In most of the experiments 

mixtures of calcium carbonate with the hydrated magnesium compound were obtained. When, however, the pasty mass formed by 

precipitating the two carbonates together was heated to temperatures 

above 120°, union took place and dolomite was formed. From the 

fact that a sedimentary dolomite could thus be produced, Hunt concluded that dolomite is generally a chemical precipitate, a view which 

is not widely held to-day.

1 Cited in a memoir by A. Favre, Compt. Rend., vol. 28,1849, p. 304.

2 Idem, vol. 33,1851, p. 64.

a Compt. Rend., vol. 47,1858, p. 01.

4 Jahresb. Chemie, 1847-48, p. 1290. Also Compt. Rend., vol. 20,1848, p. 311.

» Kept. Brit. Assoc. Adv. Sci., 1856, p. 77.

s Am. Jour. Sci., 2d ser., vol. 28,1859, pp. 170, 365; vol. 42,1866, p. 49.
'SEDIMENTAEY AK'p-DETTxErAJj.-EOCKS. 559

/ Still jnore recently G . Linck 1 has reported a synthesis of dolomite 

effected, in -the' following* way: Solutions of magnesium chloride, 

magnesium sulphate, and ammonium sesquicarbonate were mixed, 

and to the mixture a solution of calcium chloride was added. An 

amorphous precipitate formed, which upon prolonged gentle heating 

in a sealed tube became crystalline, and had the composition and 

optical properties of dolomite. Linck believes that the conditions of 

this synthesis are fulfilled in nature, and that ammonium salts derived 

from organic decomposition play an important part in the formation . 

of marine dolomite. Following Linck, K. Spangenberg 2 succeeded 

in producing dolomite by heating vaterite with a solution of sodium 

carbonate and magnesium chloride, .at 1SO°-200° in an autoclave 

under a pressure of 50 atmospheres of carbon dioxide.

In several instances the deposition of magnesium travertine and 

even of crystallized dolomite from natural waters has been observed. 

According to J. Girardin,3 the travertine formed by the mineral 

spring of St. Allyre, near Clermont, in France, is rich in magnesium 

carbonate. In recent travertine he found 28.80 per cent of MgC03 

with 24.40 of CaC03 , and in old travertine the proportions were 26.86 

and 40.22, 'respectively. Whether this represents dolomite or a mixture of the carbonates was not determined. A. Moitessier 4 found 

that in a badly closed bottle of water from another French spring 

distinct crystals of dolomite had been deposited. In another water 

from a hot spring near the Dead Sea, which was transported to Paris 

in a sealed tube, similar crystals were found by A. Terreil.5 From 

this observation Lartet concludes that the dolomites of the Dead Sea 

region were probably formed through the impregnation of limestones 

by magnesian waters.

On the other hand, E. von Gorup-Besanez" found that springs 

from the dolomites of the Jura, which contain and calcium magnesium carbonates in the dolomite ratio, deposit the mixed salts 

upon evaporation and not the double compound. Gorup-Besanez 

observed, however, that carbonated waters, acting upon dolomite, 

dissolve the mineral with its ratios undisturbed. The occurrence 

of dolomite geodes in magnesian limestones would seem to show 

that in such cases at least the double salt can be re-formed. Similar 

results were earlier obtained by T. Scheerer,7 when artificial solutions 

of calcium and magnesium bicarbonate were allowed to evaporate

1 Monatsh. Bcutsch. goal. Gosoll., 1903, p. 230. YV. Mcigcn (Geol. Rundschau, vol. 1, p. 131, 1900), 

repeated Linck's experiment, but without success.

2 Zeitschr. Kryst. Min. , vol. 52, p. 529, 1913.

3 Anaales des mines, 3d ser., vol. 11, 1S37, p. 400.

4 Jahresb. Chemie, 1866, p. 178.

B Cited by L. Lartot, Bull. Soc. g<5ol. France, 2d ser., vol. 23, 1SCG, p. 750. 

o Liebig's Annalon, Beil. Band 8, 1872, p. 230.

i Neues Jahrb., 1866, p. 1. See also E. T. Hardman (Proc. Iloy. Irish A cad., vol. 2, pt. 2, 1S77, p. 705) 

f orsimilar experimental evidence as to the salution of calcium carbonate from ma^nesian limestones.
560 DATA OF GEOCHEMISTKY.

spontaneously at ordinary temperatures. Only mixtures were 

formed, no dolomite. He also found that powdered chalk precipitated magnesium, carbonate from a bicarbonate solution, although 

carbonated waters dissolved calcium carbonate out of magnesian 

limestones. The last observation, however, had been made by 

other chemists previously.

In Hunt's investigations it became evident that temperature is 

an important factor in the formation of dolomite. The same conclusion is to be drawn from F. Hoppe-Seyler's experiments. 1 At 

ordinary temperatures a solution of magnesium chloride acting 

upon calcium carbonate for several months yielded no dolomite. 

Sea water mixed with an excess of calcium carbonate and saturated 

with carbon dioxide, after standing four months in a closed flask, 

also failed to form dolomite. But when magnesium salts or sea 

water were heated with calcium carbonate in sealed tubes, then 

both dolomite and magnesite were formed. Carbonate of lime, 

heated to over 100° with a solution of magnesium bicarbonate, gave 

this result.

In the earlier researches upon the conversion of limestone into 

dolomite little or no attention seems to have been paid to the 

mineralogical character of the initial substance. In C. Element's 

experiments 2 aragonite, the less stable form of calcium carbonate 

and the form which is abundant in coral reefs, was especially studied. 

It was found that a concentrated solution of magnesium sulphate 

at 60° would partially transform aragonite into magnesium carbonate, and coral was altered in the same way. Calcite, by similar 

treatment, was but slightly attacked. Magnesium sulphate and 

sodium chloride used together at 90° C. altered aragonite strongly, 

forming a product containing as high as 41.5 per cent of MgC03 . 

Normal dolomite, ideally pure, would contain 45.7 per cent. Magnesium chloride proved to be less active than the sulphate. The 

products of these reactions consisted, however, not of dolomite, but of 

the mixed carbonates, and Klement suggests that mixtures of this 

kind would probably in time recrystallize into the double salt. He 

attributes the formation of dolomite to the action of sea water in 

closed lagoons upon aragonite that is, upon coral rock. The latter, 

as will be shown presently, is often the parent of dolomite. It must 

be observed, however, that aragonite is not the only parent of dolomite, for pseudomorphs of dolomite after calcite are well known.3

»Zeitschr. Deutsch. geol. Gesell.,vol.27,1875, p. 509. In this connection it may benoted that II. C. Sorby 

(Quart. Jour. Gool. Soc., vol. 35, Proc., 1870, p. 56) found that Iceland spar, in a solution of magnesium 

cbloride, became slowly incrasted with magnesium carbonate.

»Bull. Soc. Beige g<5ol., vol. 9, M£m. 3,1895. Min. pet. Mitt., vol. 14,1894, p. 526. See also experiment 

by O. Mahler, Inaug. Diss., Freiburg, 1006.

8 See Blum's Pseudomorphosen, p. 51, and Nachtrag, p. 23.
SEDIMENTARY AND DETRITAL ROCKS. 561

Two other investigations upon the synthesis of dolomite remain 

to be mentioned. L. Bourgeois and H. Traube 1 obtained it by 

heating a solution of magnesium chloride, calcium chloride, and 

potassium cyanate, KCNO, to 130° in a sealed tube. This mode of 

production has no geological significance, except in so far as it 

shows that the necessary carbonic acid may be supplied from organic 

or semiorganic sources. Such sources are considered by F. W. 

Pfaff,2 who has shown that the products of organic decomposition, 

as derived from the coral-building organisms, probably take part in 

the dolomitic process. Not alone carbonic acid is generated during 

organic decay, but ammonium carbonate, ammonium sulphide, and 

hydrogen sulphide are also produced, and these compounds, according to Pfaff, appear to assist in the formation of dolomite. In his 

second paper, however, Pfaff 3 states that when a current of carbon 

dioxide is passed for a long time through a warm solution of the 

sulphates and chlorides of magnesium and calcium the solution, 

upon slow evaporation at a temperature of 20° to 25°, yields a 

residue which contains a double carbonate insoluble in weak hydrochloric acid. That is, under these conditions, which might be 

approximately paralleled in the concentration of sea water, dolomite 

may be formed.

Under certain exceptional conditions magnesium carbonate may 

be deposited alone. A solution of the bicarbonate on evaporating 

spontaneously forms the hydrous salt MgC03 .3H2 0, which corresponds to the rare mineral nesquehonite. This species, described by. 

F. A. Genth and S. L. Penfield,4 from the Nesquehoning anthracite 

mine in Pennsylvania, was there produced by the alteration of a ; 

basic carbonate, lansfordite,5 3MgC03 .Mg(OH)2 .2lH2 0, which first 

formed as stalactites in one of the galleries. Nesquehonite has since 

been identified by C. Friedel 6 as a similar formation in a French 

coal mine. Such stalactiform minerals are obviously deposited 

from solution in carbonated waters.

The term "dolomite" is sometimes loosely used by geologists as 

equivalent to magnesian limestone. Any limestone containing notable amounts of magnesia may be described by this name. Properly, 

the word should be restricted to the definite double carbonate,

1 Bull. Soc. min., vol. 15,1892, p. 13.

 " Neues Jahrb., Beil. Band 9, 1894, p. 485. A later paper by Pfaff is published in vol. 23,1907, p. 529.

8 Centralbl. Min., Geol. u. Pal. ,1903,p.659. Pfaff regards pressure as an important factor in the formation of dolomite. His conclusions are criticized in an important paper by E. Philippi (Neues Jahrb., 

Festband, 1907, p. 39V), who cites evidence to show that certain dolomitic nodules have been formed by 

chemical precipitation. F. Tucan (Centralbl. Min., Geol. u. Pal., 1909, p. 506) finds that the Karst dolomites of Croatia contain sodium chloride and calcium sulphate, which suggests a marine origin. IE. 

Steidtmann (Jour. Geology, vol. 19,1911, pp. 323,392) has also studied the marine relationships of dolomite.

«Am. Jour. Sci., 3d ser., vol. 39,1893, p. 121.

6 Described by Genth, Zeitschr. Kryst. Min., vol. 14,1888, p. 255.

« Bull. Soc. min., vol. 14, 1891, p. 60. See also H. Leitmeier (Zeitschr. Kryst. Min., vol. 47,1909, p. 118) 

on the deposition of magnesia- hydrocarbonates by the mineral springs of Rohitsch, Styria.

113750° 19 Bull. 695 36
562 DATA OF GEOCHEMISTRY.

which occurs both as-a well-crystallized mineral and as a'massive 

rock. When, after allowing for natural impurities, the molecular 

ratio of lime to magnesia in such a rock is 1:1, it is legitimately, at 

least.in most cases, a dolomite, but exceptional mixtures are, of course, 

possible. Ordinarily, a magnesian limestone is a mixture of dolomite and calcite, with such impurities as sedimentary rocks and limestones in general are likely to contain. In these rocks the ratio of 

lime to magnesia is greater than 1:1, but in computation it must 

be remembered that some dolomites contain iron, which replaces 

magnesia in equivalent amounts. Ferruginous dolomite, or ankerite, 

is not rare. All the iron of a carbonate rock, however, is not necessarily a part of the carbonate. It may be present as hydroxide or 

in claylike impurities, and these possibilities must be taken into 

account in any interpretation of the dolomites. In some cases free 

magnesian carbonates must also be considered, and in certain alteration products, brucite, Mg02H2 , may also occur. Commonly the 

dolomites are fairly simple in composition, and difficulties in interpreting the analyses rarely arise.

In the study of natural dolomites as well as in the synthetic experiments which have just been described, it is often necessary to 

discriminate between the separate carbonates and the true double 

salt. In most cases this is easily done by taking advantage of differences in solubility. Calcite and aragonite dissolve easily in weak 

acetic or hydrochloric acid; dolomite and magnesite, at ordinary 

temperatures, are attacked slowly.1 These magnesian carbonates 

are not absolutely insoluble in dilute acids, but they are sufficiently 

resistant to admit of a rough separation from calcite, and their subsequent identification. From a mixture of dolomite and calcite, cold 

dilute acetic acid will dissolve the latter mineral, leaving nearly all 

of the dolomite unattacked. From mixtures of calcite and magnesite, on the other hand, all of the lime will be thus removed. Some 

magnesia also may pass into solution, for as Vesterberg has shown, 

there are magnesian carbonates, probably basic or hydrous, which 

dissolve with ease. Magnesite is even more refractory toward solvents than dolomite.

Furthermore, discrimination between calcite and dolomite can be 

effected by microchernical tests. Among the best of these is that 

described by J. Lemberg,2 whose reagent consists of a solution of 

aluminum chloride and hsematoxylin (extract of logwood). This

1 Upon these differences in solubility there is an abundant literature, which has been well summarized 

by A. Vesterberg, Bull. Gccl. Inst. Upscila, vol. 5,1931, p. 97; vcl. 6,1905, p. 254. Sec also the synthetic 

papers already cited, and Haushofer, Sitzungsb. K. Akad. Wiss. Miinchen, vol. 11,1881, p. 220.

a Zeitschr. Deutsch. geol. Gesell., vol. 40,1888, p. 357. In vol. 39,1SS7, p. 489, Lemberg describes tests 

based upon the useof terric chloride and ammonium sulphide. In a still earlier paper (op. cit., vol. 24,1872, 

p. 223) Loraberg gives tests with silver nitrate, which stains calcite and dolomite, after ignition, unequally, 

See also Otto Meycr, Zeitschr. Deutsch. geol. Gesell., vol. 31,1879, p. 415, and E. Steidtman, Bull. Gcsl. 

Soc. America, vcl. 28,1917, p. 431.
SEDIMENTARY AND DETBITAL BOOKS. 563

reagent deposits a violet coating upon calcite surfaces, but leaves 

dolomite uncolored. According to F. Cornu,1 the two minerals are 

easily distinguished by covering the powdered material with water 

and adding a few drops of phenolphthalein solution. Calcite gives 

a strong coloration; dolomite is affected but slightly. E. Hinden 2 

states that limestone is colored red-brown by ferric chloride solution, 

and blue by copper sulphate, dolomite remaining unchanged.

So far as the experimental evidence goes, dolomite can be formed 

in several ways. In specific cases, however, field evidence must be 

brought to bear. First, dolomite may exist as a true chemical sediment, although occurrences of this kind are probably rare. G. Leube 3 

described a "fresh-water dolomite" near Ulm, in Bavaria; and C. 

W. Gunibel,4 studying the dolomites of the same region, which are 

Jnterbedded with limestones, likewise asserts their sedimentary origin. T. Scheerer 5 also argues that the oldest dolomites were formed 

as chemical precipitates; and T. Sterry Hunt's 6 positive views on 

this subject are well known. Hunt's experiments help us to understand how sediments of dolomite may perhaps be formed; and it is 

also possible that algae may precipitate mixed carbonates just as they 

do calcareous marl. Precipitation by ammonium carbonate as a 

product of organic decomposition has already been mentioned, and 

so has the similar activity of bacteria as shown by Drew. Furthermore, the fact that finely divided calcium carbonate will precipitate 

magnesium carbonate from its solution in sea water was established 

by the experiments of Scheerer and Hoppe-Seyler, already cited; 

and the formation of that precipitant may precede the deposition of 

the magnesian compound. In all these processes, however, mixed 

carbonates, not true dolomite, are first formed. Their union into 

dolomite, which Klement effected rapidly at moderately high temperatures, may well take place slowly in the cold if given sufficient 

time. Prolonged contact of the moist particles under even moderate 

pressures mignt permit a degree of molecular mobility which would 

bring about gradual combination.

Magnesian carbonates are, however, deposited with calcium carbonate by marine organisms, albeit in small relative amounts. G. Forchhammer 7 made many analyses of shells and corals, finding magnesium carbonate in them in percentages ranging from 0.15 to 7.64, 

1 per cent being rather above the average. This result has been con1 Centralbl. Min., Gcol. u. Pal., 1906, p. 550.

2 Vcrhandl. Naturforsch. Gesell. Basel, vol. 15, 1903, p. 201. O. Mahler (Inaug. Diss., Freiburg, 1906) 

finds the ferric chloride unsatisfactory but obtained good results with the copper salt. On the copper test 

seealso K. Spangenberg, Zeitschr. Kryst. Man., vol. 52, p. 529,1913. 

. »Neues Jahrb., 1840, p. 371. 

. * Sitxuugsb. K. Akad. Wiss. Miinchen, 1871, Heft l,p. 4o.

6 Neues Jahrb., 1800, p. 1. ..

« See Chemical and geological essays, p. 80, aud the literature already cited.

' Neues Jahrb., 1852, p. 854. The highest figure in Forchhammer's scries was for an annelid, Serpula.
564 DATA OF GEOCHEMISTRY.

firmed by many other .investigators. - In .Lifhoihamnium nodosum 

Giimbel 1 found 2.66 percent of MgO and 47.14 of CaO; and A. G. 

Hogbom 2 in fourteen analyses of algae belonging to this class 

reports from 1.95 to 13.19 per cent of MgCO3 .

In 1906 H. W. Nichols 3 published an analysis of the skeleton of a 

recent crinoid, and found in it about 11 per cent of magnesium carbonate. Several years later C. Palmer, in the laboratory of the 

U. S. Geological Survey, analyzed two more crinoids, and obtained 

similar results. In 1914 the subject was taken up more extensively 

by F. W. Clarke and W. C. Wheeler,4 and 24 analyses were made, 

representing 21 genera of crinoids and a wide range of habitat. In all 

of them magnesium carbonate was found, in proportions ranging 

from 7.28 to 12.69 per cent, the amount varying with the temperature 

of the water in which the creatures lived. In cold-water forms the 

figure for magnesia was low, while in tropical forms the figure was 

high; a sharply defined relation for which an explanation is yet to be 

found. This research was followed up by a series of analyses of the 

inorganic parts of sea urchins, starfishes, and brittle stars, with results 

strictly comparable with and parallel to those found for the crinoids.5 

Similar quantities of magnesia were found, and the same temperature 

regularity was observed. In short it seems to be established that the 

inorganic constituents of any echinoderm will have the composition 

of a moderately magnesian limestone, and the largest proportion of 

magnesia will be found in organisms from relatively warm waters.6 

It is not to be assumed, however, that magnesian sediments follow 

the same rule. A dense population of forms low in magnesia would 

deposit a larger amount of it than a sparse population of richer 

Organisms. Clarke and Wheeler also report analyses of 10 fossil 

crinoids, ranging from the Ordovician up to the Eocene, but with 

inconclusive results. Alterations due to leaching and to infiltration 

of foreign substances such as silica and the carbonates of iron and 

manganese effectually obliterated all the regularities shown by the 

recent living forms.

> Abhandl. K. Akad. Wiss. Miinchen, vol. 11, 1871, p. 26.

s Neues Jahrb., 1894, Band 1, p. 262. The analyses were made by a number of chemists for Hogbom, who gives data for several shells and corals also. For more recent analyses of calcareous algae, see 

Prof. Paper U. S. Geol. 'Survey No. 102,1917. R. C. Wallace (Jour. Geology, vol. 21, p. 416,1913) has conBideredtherelationof.calcareousalgfe to the production of dolomite; '

» Field Columbian Museum, Pub. Ill, p. 31,1906. See also A. H. Clark, Proc. TJ. S. Nat. Mus.. vol. 39, 

p. 487,1911. 

' « Prof. Paper TJ. S. Geol. Survey No. 90-D, 1914.

6 Prof. Paper U. S. Geol. Survey No. 90-L, 1915.

e A few other analyses of echinoderms, namely, sea urchins and starfishes, are on record. See L. 

Schmelek, Norske Nordhavs-Expedition, No. XXVDI, p. 129,1901; and O. Biitschli, Abhandl. K. Gesel].' 

Wiss.,G6ttingen, new ser., vol. 6, No. 3, pp. 81-83,1904. In a holothurian, Stichopus rcgalis, 8.37 per cent ol 

magnesium carbonate was found. Another holothurian analyzed by A. Hilger (Arch, gesammte PhysioJogie, vol. 10, p. 214,1875)-contained 12.10 per cent, calculated-on.the calcined ash of the creature. Localities and temperatures were not given with these analyses. '''
SEDIMENTARY AND DETRITAL ROCKS. 565

As the results obtained from the analyses of the echinoderms were 

both novel and interesting, Clarke and Wheeler continued the investigation so as to cover almost the entire range of marine invertebrates, 

and including the calcareous algae.1 Some of the data have already 

been cited in the section on phosphate rock in the preceding chapter 

of this volume. The general results as to magnesium carbonate, 

calculated as percentages of the inorganic matter alone, may be 

summarized as follows:

Percent. 

Foraminifera.......................................:.......3. 67-11. 22

Calcareous sponges........................................5. 37- 8. 00

Madreporian corals......................................... . 09- . 77

Alcyonarians..............................................6.03-15.73

Hydroids................................................. .22- 1.28

Annelids.................................................. .00- 9.72

Echinoderms.............................................5. 99-14. 08

Brachiopods..........................................;... .49- 8. 63

Bryozoans.................:................................ 63-11.08

Mollusks.................................................. .00- 2.58

Barnacles.................................................. .79- 2.49

Other crustaceans..........................................4. 84-15. 99

Two exceptions to this list must be noted. One mollusk, the 

cephalopod Argonauta, contains in its shell 6.02 per cent of MgC03 ; 

and one alcyonarian, the anomalous blue coral Heliopora, is practically nonmagnesian. As for the algse, Halimeda is nonmagnesian; 

while in the series of analyses represented by LitJiothamnium, Lithophyllum, etc., the proportion of magnesium carbonate ranges from 

10.93 to 25.17 per cent. With the alcyonarians the same relation of 

temperature to the proportion of magnesium carbonate as was found 

among the echinoderms was clearly shown; in some other series of 

analyses it was suggested but not definitely proved to exist. It was 

also found that the organisms having their calcium carbonate in the 

form of aragonite were practically free from magnesia, the high proportions being found only in calcitic shells or skeletons. This relation had previously been noted by Butschli. As magnesium carbonate is isomorphous with calcite, it seems to follow its natural partner. 

The application of all this evidence to the study of coral reefs will be 

considered a little later.

From these data it is clear that limestones formed by marine 

organisms must contain magnesia, and evidence shows that as a rule 

they contain rather more of it proportionally than the remains from 

which they are made. The analyses of oceanic oozes collected by the 

Challenger expedition, as discussed by Hogbom,2 show this fact very 

well, and also illustrate the tendency of the magnesium carbonate

> Prof. Paper U. S. Geol. Survey No. 102,1917. In this paper 250 original analyses are given, and also a 

goodly number from other authorities, 

a Op. cit., p. 267.
566 DATA OF GEOCHEJVIISTBY.

to accumulate, while the more soluble calcium, carbonate is dissolved 

away. That is, by the leaching of these deposits they become relatively enriched in magnesia, until in the extreme cases something 

very near the true dolomite ratio is attained. In short, a dolomite 

may be produced by concentration from a magnesian limestone, and 

either sea water or percolating waters of atmospheric origin may 

operate in this way. Grandjean x was probably the first to interpret 

certain dolomites as having been formed by this process, a view which 

various other writers have adopted and which is well developed in 

Hogbom's niemoir. Hogbom, in addition to the facts already cited, 

brings other important evidence to bear upon the problem. He 

shows that stalactites from caverns in the coral rocks of Bermuda 

contain only 0.18 to 0.68 per cent of magnesium .carbonate, while the 

rocks themselves carry about five times as much.2 Here the lime 

salt has dissolved much more freely than the magnesium compound. 

Hogbom also studied the marine marls of Sweden, and found that 

the transported material contained progressively larger proportions 

of magnesium carbonate as its distance from the parent limestone 

increased. Near its point of origin the marl carried 3.7 parts of 

MgCO3 to 100 of CaCO3 ; and from these figures the ratio was gradually 

raised to 36 MgC03 and 100 CaC03 . In these finely divided sediments the leaching out of calcium carbonate by atmospheric and 

glacial waters is naturally rapid, and the concentration of the dolomitic portion is effected with great ease. This mode of concentration, then, must be recognized as real, and as accounting in part at 

least for the formation of dolomite; 3 but it is not the whole story. It 

accounts for some occurrences but not all.

Coral rock, it will be remembered, consists chiefly of calcium carbonate, which in the living forms is mineralogically aragonite; but 

in 1843 J. D. Dana/1 in a rock from the coral island of Makatea, in 

the Pacific, reported magnesium carbonate to the extent of 38.07 

per cent. This approached the dolomite ratio, which requires 45.7 

per cent, and the thought was at once suggested that the rock had 

been dolomitized by the introduction of magnesia from sea water, the 

latter having possibly been first concentrated by evaporation in a 

shallow lagoon.

Since Dana's observation was made, many other investigators 

have recorded similar enrichments of coral reefs, and the synthetic 

experiments of various chemists, as cited in the preceding pages, have

1 Neues Jahrb., 1844, p. 543.

2 It is well known that stalactites from caverns in .dolomitic limestones consist essentially of calcium 

carbonate, with little or no magnesia,.

' s For an elaborate discussion of this side of the dolomite problem see G. Bischof, Lehrtmch der chemischen 

lind physikalischen Geologic, 2d ed., pp. 52-91. The older data are.well summarized. See also C. "SV. Hall 

and F. W. Sardeson, Bull. Gcol. Soc. America, vol. C, 1894, p. 189. "

< See Dana's Coral and coral islands, 3d ed., p. 393. Analyses by P>. Silliman, jr. The island is called 

Metia by Dana. " -
SEDIMENTARY AND DETRITAL ROCKS. 567

shown that the indicated reaction can actually take place. Element's 

experiments, especially, have helped to make this point clear. In 

the coral reef of Porta do Mangue, Brazil, J. C. Branner l reports 

6.95 per cent of magnesia, equivalent to 14.5 of carbonate, while the 

corals themselves contained only 0.20 to 0.99 per cent of MgO. In 

the islands of the Pacific Ocean a large number of similar cases have 

been observed, the analyses by E. W. Skeats 2 reaching a maximum 

of 43.3 per cent of MgC03 . From instances of this kind, and from 

the resemblance of many dolomites to reef rocks, it has been commonly inferred that dolomitization is generally, or at least often, 

effected in this way, lime being gradually removed and replaced by 

magnesia from the sea. 3 In other publications Skeats 4 has advanced additional arguments in favor of the replacement theory, 

and has shown that the leaching of the remains of marine organisms 

is not by itself adequate to account for the formation of marine 

dolomite.

The most striking illustration of the change from limestone to 

dolomite is furnished by the borings on the atoll of Funafuti, as discussed by J. W. Judd.5 The principal boring was driven to a depth 

of over 1,100 feet through coral and coral rock all the way, and samples 

of the cores were analyzed for practically every 10 feet of the distance. From the table of data presented by Judd, the following 

figures are selected:

Magnesium carbonate in borings on atoll of Funafuti.

Depth, teet.

4

13

15

20

26

55

110

159

200

250

Percentage 

MgCOj.

4.23

7.62

16.4

11.99

16.0

5.85

2.11

.79

2.7

4.9

Depth, feet.

295

400

500

598

640

698

795

898

1, 000

]., 114 '

Percentage 

MgCOj.

3.6

3.1

2.7

1.06

26.33

40.04

38. 92

39.99

40.56

41. 05

These figures are very remarkable. They show, first, an enrichment in magnesium carbonate near the surface, then an irregular

l Bull. Mus. Comp. Zool., vol. 44,1904, p. 2C-1. Analysis of rock by R. E. Swain, of the corals by L. R. 

Lcnox.

»Idem, vol. 42,1903, pp. 53-120. See also R. L. Shcrlock, idem, vol. 38,1903, p. 349.

3 See R. Harkncss, Quart. Jour. Geol. Soc., vol. 15,1S59, p. 103, on dolomite near Cork, Ireland. Also 

C. Doeltcr and R. Hocrncs, Jahrb. K.-k. geol. Reichsanstalt, vol. 25, p. 293. These authors give a bibliography of dolomitization down to 1875, the date of their memoir.

* Quart. Jour. Gcol. Soc., vol. 61,1905, p. 384: and Am. Jour. Sci., 4th ser., vol. 45,1918, p. 185.

o The atoll of Funafuti, published by the Royal Society, London, 1904. JTor Judd's report on the chemical 

examination. see pp. 302-389.
568 DATA OF GEOCHEMISTRY.

rising and falling in much, smaller amounts, while below 700 feet the 

approach to a dolomite ratio is apparent. The surface enrichment 

Judd attributes to a possible leaching out of lime salts, and the 

irregularities may be due in part to differences in the proportions of 

the various reef-forming organisms. Some of these are more soluble 

than others, as we have already seen.

According to A. E. Finckh,1 the order of abundance of the organisms 

contributing to the Funafuti limestone is (1) Liihotliamnion, 2 (2)Halimeda, (3) Foraminifera, and (4) the corals, including Heliopora and 

other alcyonarians and the millepores. To call the Funafuti rock a 

coralline limestone is therefore somewhat misleading. Here at least 

the corals play a very subordinate part. 3

For the intensive study of coral reefs the analyses by Clarke and 

Wheeler, together with those made by others, are of great significance. 

The limestone immediately below the zone of living forms owes a 

great part of its composition to all the organisms that flourished on 

the reef. Algse, corals, alcyonarians, Foraminifera, and other forms 

of less importance contribute their remains to the building of the 

limestone, which may vary in composition as the life upon it varies. 

Corals may predominate in one place, algae in another. Precipitated 

carbonates, whether of bacterial origin or not, must also be taken into 

account, and their quantity may be large. At first the calcitic algae, 

Foraminifera, alcyonarians, echinoderms, and perhaps crustaceans 

furnish a direct supply of magnesium carbonate; but the aragonitic 

algae, mollusks, corals, millepores, etc., by virtue of their easier alterability and consequent enrichment from sea water, may be equally 

significant. All classes of marine organisms contribute more or less 

to the formation of dolomite.

In this connection the report on Funafuti is remarkably suggestive. 

The rock throughout contained organic remains and was studied both 

microscopically and chemically. At a depth of 4 feet from the surface it contained 4.23 per cent of magnesium carbonate and at 15 feet 

16.4 per cent. To this point a concentration by leaching is strongly 

indicated, even if not absolutely proved; and it is probable that the 

relatively soluble aragonitic structures had been, in part at least, dissolved away. The fact that many sections of the core were " cavernous " in structure is evidence that solution had occurred. Furthermore, the solution must have been aided by the carbonic acid generated during the decomposition of the organic matter of the 

organisms, and through its agency calcite would be dissolved also.

At 26 feet the rock contained 16 per cent of magnesium carbonate, 

but the proportion rapidly decreased, with slight variations, until at

1 The atall of Funafuti, pp. 125-150.

8 A general term, which includes not only LitJiotJiamnium but also other related algae. 

» At Tutui'la,.Samoa,accordingAoX.»R. Ca»y (Proe. Nat.-Acad: Sci.rvol. 3,1917, p. 545), alcyonarians 

are more important as reef builders than the stony corals.
SEDIMENTARY AND DETRITAL ROCKS. 569

a depth of 637 feet crystals of dolomite began to appear. At 640 feet 

the magnesium carbonate suddenly rose to 26.33 per cent, and from 

that point it steadily increased until at the bottom of the boring, 

1,114 feet, it was 41.05 per cent, which is very near the figure required 

for pure dolomite. In short, within 3 feet the rock changed from 

almost nonmagnesian limestone to one that was strongly dolomitic, 

and in 50 feet more it became really dolomite. This abrupt change is 

most easily explained upon the hypothesis that the dolomite at the 

bottom of the Funafuti boring represents an old reef which was submerged by one of those fluctuations in the level of the ocean which 

are known to occur elsewhere. After a long rest it was again elevated 

to the surface, and then a new period of reef building began. The 

new reef is superimposed upon the old one. The assumption as to 

changes of level here is supported by the fact that on other islands 

in the South Pacific dolomitized reefs are found at hundreds of feet 

above sea level. 1

Although the chemical composition of the Funafuti limestone has 

been more thoroughly studied than that of the limestone at any other 

locality, the general process is not necessarily the same elsewhere. 

Its details may be duplicated, but their order is often different. 

Somothing of this sort is shown by the following analyses by George 

Steiger 3 of borings from an artesian well at Key West, Florida.

Lime and magnesia in borings at Key West.

Depth, feet.

25

100

150

350

600

775

1,125

Percentage 

CaO.

54.03

54.01

54.38

51.46

48.87

46.53

53.84

Percentage 

MgO.

0.29

.77

.86

1.67

2.50

6.70

.86

Depth, feet.

1,325

1,400

1,475

1.625

1,850

2,000

Percentage 

CaO.

54.49

55.12

54.48

53.90

54.28

54.02

Percentage 

MgO.

0.62

.30

.73

1.14

1.12

1:06

Here there is a progressive magnesian enrichment down to 775 

feet, and then a falling off, but no such thorough alteration appears 

as at Funafuti. What different conditions may have existed to 

account for these differences of composition is not known. '"'

It is of course evident that dolbmitization by replacement heed 

not bo limited to the action of sea water upon coral reefs. Magnesian 

spring waters may be equally effective, and are so locally, as observed

1 See E. W. Skeats, Papers from tho Tortugas laboratory of the Carnegie Institution of Washington, 

vol. 5,1914, p. 06, and E.-L. Sherlock, Bull. Mus. Comp. Zool., vol. 38,1903, p..349.

2 Analyses made in the laboratory of the United States Geological Survey. Published in full in Bull. 

No. 228,1904, p. 309. Boring described by E. O. Hovey, Bull. Mus. Comp. Zool., vol. 23,1896, p. C3.
570 DATA OF GEOCHEMISTRY.

by J. E. Spun 1 in the -rocks about Aspen, Colorado. ~ In that region ,_ 

hot springs containing magnesium are manifestly operative in transforming limestone to dolomite. But large areas of dolomite are not 

likely to originate in that way. Where, however, limestones are 

situated near magnesian eruptive rocks, dolomitization due to this 

cause is to be anticipated. > 

From what has been said already, the chief chemical processes ^ 

involved in the formation of marine dolomite may be summarized as 

follows: First, the mixed carbonates may be directly precipitated in 

shallow waters, either by changes of temperature and concentration v 

of atmospheric C02 , or by ammonium carbonate produced during the 

decomposition of the remains of marine - organisms. In the latter 

process, however, carbon dioxide is also formed, which tends more or 

less to retain the carbonates in solution. Here, then, are two opposing processes, and the extent of precipitation is therefore variably

limited. Second, the carbonates contained in the shells or skeletons . "y^-~~"

of marine invertebrates are decomposed. Third, magnesium carbonate is concentrated by the leaching away of the more easily - 

dissolved calcium salt. Fourth, the so-called coralline rock is en- ^ 

riched at the expense of the magnesium salts contained in sea water. 

All four processes may be in operation simultaneously, one or another 

predominating according to conditions which are not likely to be 

quite the same at any two localities. The fourth process, however, is 

generally the most important, and it precedes the union of the car- /- 

bonates, into true dolomite.

The leaching process, which commonly follows the line that has r 

already been emphasized, may, however, sometimes be reversed. ^ 

The comparatively soluble trihydrate of magnesium carbonate, 

MgC03 .3H20, which is represented in nature by the rare mineral 

nesquehonite, is known to occur in the form of stalactites in certain v 

coal mines, where it was probably produced by the percolation of 

ground waters rich in magnesia and in carbon dioxide.2 This reaction may account for the fact that in many localities fossiliferous *- 

beds overlie beds of limestone which are richer in magnesium carbonate, an enrichment having taken place analogous to that which is 

so fully recognized in modern studies of ore deposits. This process - 

has been given emphasis by General E. Jourdy,3 who regards it as an 

important step in the development of dolomite. The magnesium

1 Mon. U. S. Ocol. Survey, vol. 31,1898, p. 206. Spurr (p. 216) also reports an interesting silicification of ""* 

limestones, which is visible in all its stages. The final product is made up of quartz grains. The magnesian enrichment of slates at the expense of sea water has been described by J. A. Phillips, Quart. Jour. 

Geol. Soc., vol. 31,1875, p. 321. A recent paper by M. Nahnsen on the formation of oolite and dolomite is 

in Neues Jahrb., Beil. Band 35,1913, p. 277. A study of the mixed carbonates of lime, magnesia, and iron, ^ 

by K. Griinsberg, is in Zeitschr. anorg. Chemie, vol. 80,1913, p. 337. For an attempt to apply the principles 

of physical chemistry to dolomitization, see R. C. Wallace, Compt. rend. XII Congi g&>l. internat... 1913, 

p. 875. ' ^

2 H. Leitmeier has also identified nesquehonite as a deposit from the water of a mineral spring. See 

Doelter's Handbuch dcr Minoralchemie, vol. 1,1912, p. 262. ^ 

a Bull. Soc. G(§ol. France, 4th ser.0 vol. 14,1914, p. 279; vol. 16,1916, p. 3.
SEDIMENTARY AND DETE1TAL ROCKS. 571

carbonate thus transferred from the upper to the lower strata he 

believes is derived from the remains of marine algae and other organisms. Whether complete dolomitization can be effected in this 

manner is, however, doubtful.

Taking all the evidence into account it seems clear that magnesian 

limestones may be produced in more than one way, and the authorities upon the subject do not always agree as to the relative importance of the different processes. R. A. Daly,1 for example, attaches 

great importance to the formation of dolomite as a precipitate, 

especially in pre-Devonian time. These older limestones are much 

more highly magnesian than those of recent geologic periods, and 

those laid down since the Carboniferous are on the average but 

slightly dolomitic. He argues that the pre-Cambrian ocean was 

nearly limeless but somewhat magnesian, and that the carbonates 

were precipitated by the products of organic decomposition. On the 

other hand E. W. Skeats,2 E. Steidtmann,3 and F. M. Van Tuyl 4 regard the replacement theory as the most satisfactory. Van Tuyl's 

memoir is an excellent critical summary of all the different views as 

to the origin of dolomite and is rich in references to literature.

The following analyses of magnesian limestones were made in the 

laboratory of the United States Geological Survey.5 Other analyses 

in abundance are scattered through the literature of limestones.

Analyses of magnesian limestones.

A. Green Peak Quarry, Dorset, Vermont. Analysis by George Steigcr. Described by T. N. Dale in 

Bull. No. 195, 1902.

B. "Knox dolomite," Morrisville, Alabama. Analysis by V/. F. Hillebrand. Described by I. C. Russell in Bull. No. 52, 18S9.

C. Penokee district, Yftseonsin. Analysis by Hillebrand. See E. D. Irving and C. It. Van Hlso, in 

Hon., vol. 19,1892.

D. "Niobrara dolomite," Denver Basin, Colorado. Analysis by L. G. Eakins. Described by Emmons 

in Mon., vol. 27,1890.

E. Near Red Mountain, Silver Peak district, Nevada. Analysis by Steigcr.

F. The theoretical composition of ideally pure dolomite.

SiO..........................

A1203 ........................

Fe203 ....... .................

PeO

MnO..... ....................

MgO. ........................

CaO. ........................

Na.0... .....................

K20.... ......................

H20-... ......................

H20+-- ...... ................

ro

p r2o u5 . ........................ ci...... .....................

A

8.36

1.77

.22

1.08

1G.68

29. 03

.06

1.08

m

.42

41.66

100. 39

B

3.24

.17

.17

.06

20.84

29.58

} .30

4* twl

99.90

C

6.63

.03

.75

.08

20.68

30.94

| .27

46.27

Trace.

99.65

D

12.01

.54

.11

90

18.03

27.49

I M

} -w.

41.40

03

100.42

E

0.31

1.89

20. 19

30. 35

47 91

99.95

F

91 0

30.4

47.7

100. 0

1 Bull. Geol. Soc. America, vol. 20, 1909, p. 153. " 

3 See anto, p. 507.

» Jour. Geology, vol. 19, 1911, pp. 338, 392; Bull. Geol. Soc. America, vol. 28, 1917, p. 431. 

* Ann. Kept. Iowa Geol. Survey, vol. 25, 1914 (pub. 1916), pp. 251-422.

e See Bull. U. S. Geol. Survey, No. 591, 1915, pp. 225-249, for these analyses and others. See also Van 

Tuyl, op. cit. For analyses of Belgian dolomites see A. Firket, Ann. Soc. g&>l. Belg., vol. 11,1883, p. 221.
572 DATA OF GEOCHEMISTRY.

Under ordinary atmospheric and aqueous conditions dolomite 

alters like limestone, but less readily. By volcanic agencies, that is, 

the combined action of heated or fused rocks and steam, dolomite is 

sometimes transformed into a substance which was once thought to 

be a distinct mineral species, and was named predazzite and pencatite by different investigators. This substance has been interpreted 

by Damour,1 G. Hauenschild,2 J. Roth,3 and J. Lemberg 4 as a mixture of caloite and brucite,. MgO2H2 . O. Lenecek,5 however, regards 

it as a mixture of calcite and hydromagnesite, the latter being partly 

pseudomorphous after periclase and partly an infiltration. In either 

case the dolomite has been altered by the transformation of its magnesium carbonate into a basic salt or into hydroxide. The latter 

compound, under some conditions, can be leached away, leaving 

nearly pure calcite; or it may be dehydrated, forming periclase, 

MgO. Predazzite was first observed at Predazzo, in the Tyrol; and 

Lemberg, by acting on normal dolomite from that locality with 

steam, obtained a similar product. A like alteration of dolomite 

from a Russian locality was also reported by F. Rosen.6

MAGNESITE.

Magnesite, magnesium carbonate, MgC03 , is closely related to 

dolomite, but its origin is generally quite different. Dolomite is 

commonly of marine origin; magnesite is much more frequently 

formed above sea level. Its most common occurrences are due to 

the alteration of the more easily decomposable rocks, especially peridotites and serpentines. Upon such rocks carbonated waters act, 

dissolving away the magnesia as carbonate to be deposited elsewhere. 

Either magnesium bicarbonate or the trihydrate may take part in 

this reaction. Opaline silica is formed at the same time, but appears 

as a common impurity in the magnesite. Ferrous carbonate is also 

formed, often in sufficient quantity to bring about a transition into 

the mixed carbonate, ankerite. In some instances the magnesian 

solutions, instead of depositing their load directly, act upon limestone or even dolomite, replacing calcium by magnesium. K. A. 

Redlich and 0. Grosspietsch 7 have described a dolomite which had 

inclusions of crinoidal remains completely altered into magnesite. 

The crinoids themselves are highly magnesian 8 and had in this case 

lost their lime. \ '

'' Bull. Soc. g6ol. France, 2d ser., vol. 4, 1847, p. 1050.

"Sitzirngsb. K. Akad. Wiss. Wien, vol. CO,"1870, p. 795.

a See Allgemeine und chemische Geologie, voh 1, pp. 422-425. Roth cites many, analyses of altered 

dolomites and gives the data concerning predazzite with considerable fullness.

< Zeitschr. Deutsch. geol. Gesell., vol. 24,1874, p. 187.

6 Min. pet. Mitt., vol. 12,1892, pp. 429,447. Le'neCek gives a good summary of the literature of predazzite.

e Arch. Naturlcunde Liv., Esth. u. Kurlands, 1st ser., vol. 3, 1804, p; 142. 

'' Zeitschr. prakt. Geologic, vol. 21,1913, p. 90.

s See ante, p. 564.
SEDIMENTAEY AND DETR1TAL BOCKS. 573

Magnesite is also known as a sedimentary-deposit, formed by precipitation. Such an occurrence is commercially exploited near Bissell, California, and has been described by H. S. Gale. 1 Here, apparently, magnesian solutions, probably of the sulphate, have become 

mixed with solutions of sodium carbonate. Under such conditions 

a bed of magnesite could be formed.

The three processes thus outlined, namely, decomposition of magnesian rocks, replacement of limestones, and chemical precipitation, 

probably account for all the deposits of magnesite of any large significance.. Doubtless the mineral is sometimes formed by other processes, in marine muds, for example, or by pneumatolytic (volcanic) 

agencies, but these are of minor importance. They need no detailed 

consideration here. For a more complete statement, with abundant 

references to European literature, the papers by K. A. Redlich 2 

should be consulted.

IRON CARBONATE.

Another important rock-building carbonate is siderite, the ferrous 

carbonate FeC03 . Its formation as bog ore has already been considered,3 together with its transformation into limonite, but its relations to limestone and dolomite remain to be noticed. Between 

these rocks there are many transitional mixtures, and ankerite, the 

ferriferous dolomite, is one of them. .This mineral contains iron 

replacing magnesium, to use the ordinary phraseology, but this 

implies that the double salt CaFeC2 00 exists isomorphous with and 

equivalent to the magnesian compound, dolomite. The two salts, 

CaFeC206 and CaMgC2Oe , may commingle in any proportion, and varieties containing manganese carbonate are also known. So, too, there 

are mixtures of magnesite and siderite, known as breunnerite, mesitite, 

and pistomesite, but they are comparatively unimportant except in 

the study of isomorphism. The manganese carbonate, rhodochrosite, MnC03 , is usually a mineral of metalliferous veins.

As bog ore, siderite is deposited from a bicarbonate solution in 

presence of organic matter and out of contact with air. But siderite, 

like dolomite, may also be formed by replacement when iron solutions act upon limestones. H. C. Sorby 4 found that Iceland spar 

immersed in a solution of ferrous chloride was slowly transformed 

into crystalline siderite; in ferric chloride, on the other hand, ferric

1 Bull. U. S. Geol. Survey No. 540, 1914, p. 483. See also L. A. Palmer, Eng. and Min. Jour., vol..102, 

1916, p. 965. Gale also describes a number of other localities in California. In an earlier bulletin (No. 

355, 1908) F. L. Hess has described some of the same localities, and also gives a summary of other localities of commercial significance throughout the world. ' . 

 a Doelter's Handbuch der Mineralcheinie, vol.1, 1912, p. 243; and Fortschr. Min., Krist., Petrog., vol. 

4, 1914, p. 9. See also> with reference to Canadian localities, H-.'-Frechette, Trans. Canadian Mining Inst., 

vol. 19, p. 139; and M. E. Wilson, Geol. Survey, Canada, Mem, No..98. 1917. A brief paper by S. ,H. Dolbear on:the''geocbemistry of magnesite is in Min. and Sci. Press, .vol. 114,1917, p..237. ...

a See ante, p. 528. 

< Quart. Jour. Geol. Soc., vol. 35, Proc., 1879, p. 73.
574 DATA OF GEOCHEMISTRY.- 

hydroxide was formed. A similar precipitation of limonite was 

observed by G. Keller 1 when calcite was treated with ferric sulphate. 

Reactions of this kind have often been invoked in the interpretation of sedimentary iron ores. J. P. Kimball,2 for example, regards 

the reaction of ferrous solutions upon limestones as of the highest 

importance, and refers to isolated masses of coral reef in Cuba which 

have been so replaced by iron compounds. Fossils, originally calcareous, but now composed of limonite, are not rare. In the Jurassic 

limestones of central France ores of iron, manganese, and zinc are 

widely disseminated. According to L. Dieulafait,3 these ores were 

precipitated from solution by calcium carbonate, the iron first, zinc 

and manganese later. The iron ores are always at the bottom of 

the series, and the other metals are found in the overlying limestones. 

Like carbonate of lime, iron carbonate may be removed from solution by aquatic vegetation. The process, however, is different in 

one particular. Ferrous carbonate is easily oxidized to limonite, and 

that change, which takes place in air alone, is doubtless accelerated 

by the oxygen which the plants exhale. The deposit formed is not 

siderite then, but hydroxide. Similar precipitation of limonite may 

also occur from sulphate solutions, as in or near a chalybeate spring 

in Death Gulch, Yellowstone National Park. Here, according to 

W. H. Weed,4 the mosses form, from the water of the spring, an iron 

sinter, which was analyzed by J. E. Whitfield in the laboratory of the 

United States Geological Survey with the following results:

Analysis oj iron sinter. 

Si02 .................. ......................................... 1.37

Fe2 03 .................................... .................... 63.03

A12 03 --........................:............................ .08

S03 .................................... ..................... 8.35

H2 0 and organic, matter................... ................... 26. 94

99. 77

The instability of ferrous carbonate is also shown by the deposits 

of iron rust around iron-bearing springs in general, and by the formation of stalactites of limonite. Such stalactites were formed exactly 

like calcite stalactites, by carbonate solutions, only the iron salt has 

decomposed and left residues of hydroxide. According to T. Sterry 

Hunt 5 the alteration of siderite to. limonite is attended by a contraction of 27.5 per cent, whence limonite ore bodies are often porous or 

spongy.

The vast deposits of iron ores in the Lake Superior region, limonites, hematites, magnetites, etc., are now regarded as in great 

measure secondary bodies derived from iron carbonates of sedimeni Nettes Jahrb., 1882, Band 1/ref., p. 363. 'Compt. Ren<L,-w>l. 100,1885, p.«6<J. 

2Am. Jour. Sci., 3d ser., vol. 42,1891, p. 231. * Am. Geologist, vol. 7,1893, p. 43. 

6 Canadian Naturalist, vol. 9, 1881, p. 431.
SEDIMENTAHY AND DETEITAL EOCKS. 575-

tary origin. The process by which their concentration was probably 

effected has been summed tip by C. R. Van Hise 1 as follows: First, 

meteoric waters attacked the upper portions of the original carbonate, oxidizing the latter to limonite. In so doing the waters lost 

their dissolved oxygen and became carbonated. In this condition 

the waters dissolve ferrous carbonate, with some silicate, and transfer 

it to lower levels. Later, the surface oxidation having been completed, waters charged with atmospheric oxygen percolate downward, 

mingle with the iron solutions previously formed, and precipitate 

limonite. The latter, by heat and pressure, may be transformed to 

hematite. A similar interpretation is given by A. Brunlechner 2 to 

the associated siderite and limonite at Hiittenberg in Carinthia. In 

this case, however, the waters charged with ferrous carbonate redeposit it upon contact with limestones. Here also the original formation, the main ore body, is sedimentary.

The following analyses represent mixed carbonates, mainly ferriferous :

Analyses of mixed carbonates. «

A. Iron carbonate, Sunday Lake, Michigan. Analysis by W. F. Hillebrand.

B. Iron carbonate, Penokeo district, Michigan. Analysis by R. B. Riggs.

C. Iron carbonate, Gunflint Lake, Canada. Analysis by T. M. Cbatard.

. D. Ferrodolomito, Marquetto district,-Michigan. Analysis by G. Sleiger. For analyses A, B, f, Dr 

and others, see Bull. U. S. Geol. Survey No. 228,1904, pp. 318-320.

E. Cobaltiferous siderite, from a mine near Neunkirchen, Germany. Analysis by G. Bodlander, Nones 

Jahrb., 1892, Band 2, p. 236.

F. Mangandolomite, Groiner, Tyrol. Analysis by K. Eisenhuth, Zeitschr. Kryst, Min., vol. 35,1902i 

p. 582. Other analyses of dolomite, etc., are given in this paper.

Insoluble . ....................

Si02 .......... ................

Ti02.. ........................

Al-Ai- -.- .--- ..............

Fe203 ........................

FeO.. ........................

MnO............. ............

CoO.........................

CaO............. ............

MgO. ........................

E20........... ..............

H20+.... ....................

P O

cfc::::::::::::::::::::::>:

S03 .. .......................

A

28.86

.20

.1.29

1.01

37.37

.97

.74

3.64

. bo

25. 21

99.97

B

15.62

4.27

8.14

32. 85

5.06

.81

2.66

.00

30.32

100. 41

C

23.90

None.

.07

.44

10.72

.28

22.25

8.52

None.

.99

Trace.

32.42

.17

99.76

T)

26. 97

1.30

2.31

39.77

.29

.66

1.94

.09

.10

.51

.03

26.20

100. 17

E

 45.34

3.85

1.21

8.80

41.55

100. 75

T

0. 16

6.59

23.41

10.48

14.58

45.59

100. 81

1 Twenty-first Ami. Kept. U. S. Goal. Survey, pt. 3, 1900, p. 326. Monographs 19, 28, 36, 43, 45, and 

4C of the Survey, by Irving, Van Hiso, Clements, Smyth, Bayley, and Leith, deal exhaustively with these 

"Lake Superior" ores. See also .T. E. Spurr, Bull. No. 10, Geol. Nat. Hist. Survey Minnesota, 1894, on 

the Mesabi ores-and B. Weidman, Bull. No. 13, Wisconsin Geol. Nat. Hist. Survey. 1804, on the Baraboo 

district. Bull. No. 6 of the Minnesota Survey, 1891, by N. H. and H. V. Winchell, is devoted to a discussion of the Minnesota deposits.

2 Zeitschr. prakt. Geologie, 18S3, p. 301.
576 DATA OF GEOCHEMISTRY.

SIXJCATED IRON ORES.

In addition to siderite, certain sedimentary silicates serve as sources 

for limonite and hematite ores. Glauconite, for example, was suggested by R. A. F. Penrose 1 as a possible parent of iron ore, and a 

green silicate from which the Mesabi ores are derived was placed 

under glauconite by J. E. Spurr.2 C. K. Leith,3 however, in his 

report on the Mesabi district, has shown that the green mineral of the 

ferruginous cherts is not glauconite, but a hydrated ferrous or ferrosoferric silicate, containing n.o potassium. To this silicate he gives the 

name greenalite. Its composition, as shown by the analyses made by 

G. Steiger 4 in the laboratory of the United States Geological Survey, 

is not accurately determinable, for the green granules can not be 

mechanically separated from the enveloping chert. Three analyses 

of the portion of the rock soluble in hydrochloric acid gave the following results, after union of like bases and recalculation to 100 per 

cent. For comparison with them, in a fourth column, I give an analysis by F. Field 5 of a green, massive, chloritic mineral associated 

with the cronstedtite of Cornwall:

Analyses of greenalite, etc.

Si<\... ...... .................................

FeA ..................-.:................

FeO.........................................

H20... ......................................

Greenalite, Steiger.

1

30.08 

34.85 

25.72 

9.35

100. 00

2

30.49 

23.52 

36.92 

9.07

100. 00

3

38.00 

8.40 

46.56 

7.04

100.. 00

Cornwall, 

Field. .

31.72 

18.51 

39.46 

11.02

100. 71

Field's mineral and the greenalite No. 2 are very similar, and 

approach in composition a hydrated compound of the garnet type, 

Fe///2Fe//3 (Si04) 3 .3H20. The third greenalite analysis, however, is 

of an almost entirely ferrous compound, a hydrous metasilicate 

approaching the formula FeSi03 .aq. It is evident that the absolutely definite silicate is yet to be identified.

In the analyses cited the soluble green granules formed from 48 to 

82.5 per cent of the entire greenalite rock, which, according to Leith, 

represents a marine sediment analogous to glauconite. From this sil1 Ann. Rept. Geol. Survey Arkansas, vol. 1,1892. This is a monograph on the iron ores of Arkansas.

3 Bull. No. 10, Geol. Nat. Hist. Survey Minnesota, 1894.

«Mon, U. S. Geol. Survey, vol. 43,1903, pp. 237-279. On the origin of these ores see also N. H. Wihchell, 

Bull. Geol. Soc. America, vol. 23, 1912, p. 317. Winchell regards the greenalite granules as derived from 

volcanic sand.

« See C. K. Leith,.Mon. U. S. Geol. Survey, vol. 43, 1903, p. 246. -Discussion by F. W. Clarke.

* Pbilo6.-Mag.rSth ser., vol,5,1S78, p. 52.
SEDIMENTAB.Y AND DETRITAL ROCKS. 577

icate, by leaching, the hydrous hematites of the Mesabi district, were 

concentrated; but the reactions proposed by Leith to account, first, 

for the greenalite and, later, for its decomposition are largely hypothetical. Iron, in solution as carbonate, was probably brought into 

the ocean by waters from the land and precipitated as ferric hydroxide. The latter compound, partly or who.lly reduced to the ferrous 

state by organic matter derived from marine vegetation, then combined with silica, of which an excess, now represented by chert, was 

also present. These processes are possible, and the explanation thus 

offered to account for the iron-bearing rocks is probable enough to be 

provisionally held, at least until something better is offered. We 

know that ferruginous sediments are now forming in the ocean; we 

know that chert, in many cases, is of organic origin; and these facts 

are consistent with the suppositions summarized above.

At a number of European localities iron ores are found which consist partly of silicates. One of these, thuringite, is a member of the 

chlorite group; but another chloritic mineral, chamosite, which occurs 

associated with magnetite, limonite, or hematite in oolitic aggregations, is more definitely an ore of iron. Its composition, as determined by C. Schmidt 1 on Swiss material, and by E. R. Zalinski 2 on 

Thuringian specimens, as represented by the empirical formula 

3FeO.Al2 03 .2Si02 .3H2 0. The much rarer mineral cronstedtite has 

probably the same formula, with ferric oxide in place of alumina; and 

it differs from greenalite, as represented by the second analysis of the 

latter, in containing one less molecule of silica. Berthierine, from 

Hayanges, near Metz, is essentially a mixture of chamosite. and magnetite,3 and forms a valuable ore.

These silicates all undergo alteration with great ease, yielding 

oxides or hydroxides of iron. In most cases the ores containing them 

are oolitic, and form beds of sedimentary origin.4 In this respect 

they resemble glauconite and greenalite, with which, chemically, they 

are so closely allied. How they were formed is uncertain and different authorities interpret the evidence differently. The latest writer, 

E. K. Zalinski,5 regards thuringite and chamosite as secondary products, derived by alteration from earlier sediments at the bottom of the 

Lower Silurian sea. Whatever the final conclusion may be, it seems 

clear that glauconite, chamosite, and greenalite, and possibly other

i Zeitschr. Kryst. Min., vol. 11,1886, p. C01.

« Neues Jahrb., Beil. Band 19,1904, p. 40.

s See A. Lacroix, MiruSralogie dela France, vol. 1, p. 401, for this and other French occurrences.

4 On the ores, locally known as "minette," of Luxemburg and Lorraine, see Bleicher, Bull. Soc. indust. 

del'Est, 1894; L. Hoffman, Verhandl. Naturhist. Ver. preuss. Rheinlande u. Westfalens,.vol. 55, 1898, 

p. 109; H. Ansel, Zeitschr. prakt. Geologie, 1901, p. 81; and L. van Werveke, idem, p. 396. On the Thuringian ores see H. Loretz, Jahrb. K. preuss. geol. Landesanstalt, 1884, p. 120. Much other literature is 

cited in the memoirs mentioned here.

6 Noues Jahrb., Beil. Band 19,1904, p. 79. Zalinski gives a good summary of the various theories which 

have been framed in order to account for these ores.

113750° 19 Bull. 695 37
578 DATA OF GEOCHEMISTRY.

allied silicates, were all formed by similar reactions, different local 

conditions having determined which product should appear.1

GYPSUM.

The occurrence of gypsum as a sedimentary rock has already been 

partially considered.2 It may form on a large scale during the concentration of oceanic and other natural brines, and it is sometimes 

deposited from solution in fresh waters. Acid waters of volcanic 

origin, 3 or derived from the oxidation of pyrite, by acting upon 

limestones, also produce gypsum. Its appearance as an accessory 

mineral in dolomitization is due to double decomposition between 

limestone and solutions containing magnesium sulphate; and other 

sulphates may act in a similar way. L. Jowa,4 for example, prepared 

crystals of selenite by acting upon chalk with a solution of ferrous 

sulphate. Gypsum formed by reactions of this order, however, is 

commonly dissolved by the waters which assist in the process and is 

carried away, to be diffused or deposited elsewhere. As an important 

rock gypsum is generally a saline residue, and its formation in the first 

instance is probably oftener due to the action of oxidizing pyrite 

upon lime-bearing rocks than to any other cause.5

NATIVE SULPHUR.

Native sulphur is a frequent companion of gypsum, and this, too,. 

may be produced in several ways. It is known as a volcanic sublimate and is a product of reactions between sulphur dioxide and 

hydrogen sulphide. It is also formed by the incomplete combustion 

of hydrogen sulphide, probably in accordance with the equation 6 

2H2S + 02 = 2H2 0+2S. According to Becker, who studied the phenomena at Sulphur Bank, California, the oxidation of H2S to H2S04 

develops 201,500 calories. The oxidation to H2O + S develops only 

59,100 calories. Hence, where oxygen is in excess, as at the surface,

i In addition to the literature already cited, the following American reports on iron ores are worUi 

noticing: W. B. Phillips, Iron making in Alabama, a bulletin issued by the Alabama Geol. Survey in 

1908. S. W. McCallie, Bull. No. 10-A, Georgia Geol. Survey, 1900, on the brown iron ores of that State; 

H. B. C. Nitze, Bull. No. 1, North Carolina Geol. Survey, 1893; F. L. Nason, Report on iron ores, Missouri Geol. Survey, 1892; Rept. of Progress F, Second Geol. Survey Pennsylvania, 1878, on the ores of 

the .Tuniata Valley; E. T. Bumble, Reports on the iron-ore district of East Texas: Second Ann. Rept. 

Texas Geol. Survey, 1891. The most exhaustive general treatise is R. Beck's great monograph, Die Geschichte des Eisens. Les minerals do fer oolitique de France, by L. Cayeux (Ministere trav. publ., Paris, 

1909) is an important recent monograph.

* See ante, pp. 216-222.

3 J. W. Dawson (Acadian geology, 1891, p. 262) attributes the formation of gypsum in Nova Scatia to 

the action of sulphuric acid, derived from volcanic sources, on limestones.

* Annales Soc. ge*ol. Belgique, vol. 23,1896, p. cxxvii.

5 For data upon American gypsum see G. P. Grimsley, Michigan Geol. Survey, vol.9, pt. 2,1904; Grimsley 

and E. H. S. Bailey, Kansas Univ. Geol. Survey, vol. 5,1899; C. R. Keyes, Iowa Gool. Survey, voL 3, 

pp. 257-304; F. J. H. Merrill, Bull. New York State Mus., vol. 3, No. 11,1893. Bull. U. S. Geol. Survey 

No. 223,1904, by G. I. Adams and others, describes the gypsum deposits of the United States. On the 

genetic relations of gypsum and anhydrite see R. C. Wallace, Geol. Mag., 1914, p. 271.

e See G. F. Becker, Mon. U. S. Geol. Survey, vol. 13,1888, p. 254; and J. Habermann, Zeitschr. anorg. 

Chemie, vol. 38,1904, p. 101.
SEDIMENTARY AND DETRITAL ROCKS. 579

hydrogen sulphide is completely oxidized, and sulphuric acid is 

formed. A short distance below the surface oxygen is deficient, and 

then sulphur is liberated. Probably, however, the actual conditions 

are more complex. Sulphur dioxide must be produced to some extent, and that reacts with the hydrogen sulphide to form sulphur 

also. At all events, sulphuric acid and free sulphur both occur at 

Sulphur Bank, and in accordance with the conditions imposed by 

theory. The deposition of sulphur at the Rabbit Hole mines, Nevada, is also ascribed by G. I. Adams 1 to solfataric activity.

Sulphur deposits are common around mineral springs, being due 

to the imperfect oxidation of hydrogen sulphide; and the latter compound may be generated either by the action of acid waters upon 

sulphides or through the reduction of sulphates, such as gypsum, 

by micro-organisms.2 The interpretation of any given locality for 

sulphur is not easy, for different conditions reign in different places. 

In one deposit the evidence of thermal reduction may be clear, while 

elsewhere some other process is seen to have been operative. The 

most famous of all sulphur deposits is that near Girgenti, in Sicily, 

and this has been variously interpreted. Gypsum, sulphur, celestite, 

and aragonite are here intimately associated, in what is evidently a 

sedimentary formation not far removed from a center of great volcanic activity. The sulphur, therefore, has been regarded by some 

writers as volcanic, by others as a product of nonvolcanic agencies, 

and the conditions- are such that either supposition can be strongly 

supported. Sicily abounds in solf ataras, and in springs charged with 

hydrogen sulphide; and these may well have brought the sulphur 

from volcanic sources far below the surface. Its deposition, in that 

case, is due to the decomposition of hydrogen sulphide, which has 

taken place under aqueous rather than igneous conditions; and this 

view, with differences in detail, has been adopted by various authorities.3 A von Lasaulx, 4 for example, has argued that the sulphur 

was deposited from waters containing hydrogen sulphide and calcium carbonate during concentration in fresh-water basins; and G. 

Spezia 5 has developed a similar argument more fully. In order to 

account for the association of sulphur and gypsum without assuming 

the derivation of one from the other,, Spezia cites an observation of

1 Bull. U. S. Geol. Survey No. 225,1904, p. 497. See also D. F. Howetl; on Sulphur deposits in Wyoming, 

Bull. U. S. Geol. Survey No. 540-R, 1913.

2 See especially E. Plauchud, Compt. Rend., vol. 84,1877, p. 235; vol. 95, 1882, p. 1363. Also A. Elard 

and L. Olivier, idem, vol. 95, 1882, p. 846. W. F. Hunt (Econ. Geology, vol. 10,1915, p. 543) has made a 

strong argument in favor of the bacterial origin of Sicilian sulphur.

s R. Travaglia (Bol. Com. geol., 1889, p. 110), however, regards the Sicilian sulphur as having been formed 

through the reduction of gypsum by organic matter, the remains of marine animals.

< Neues Jahrb., 1879, p. 490.

B Sull' origine del solfo nei giacimenti solfiferi della Sicilia, Torino, 1892. The theories relative to tho 

origin of Sicilian sulphur are exhaustively summed up and discussed in this memoir. Several Italian 

works cited by Spezia I have not been able to consult. For a general paper on the origin of sulphur, seo 

O. Stutzer, Econ. Geology, vol. 7,1912, p. 732.
580 BATA OF GEOCHEMISTRY.

A. Bechamp, 1 who found that when hydrogen sulphide was passed 

into water containing suspended calcium carbonate the latter was 

partly decomposed and calcium hydrosulphide was formed. This 

experiment was repeated by Spezia,2 but with fragments of marble 

and under a pressure of six atmospheres. The solution thus obtained 

was found to contain a sulphide, .and upon evaporation to small 

bulk at ordinary temperatures it deposited microscopic crystals of 

calcite, sulphur, and gypsum. By a reaction of this kind, between 

the sedimentary limestones and the ascending sulphureted waters, 

the observed association of minerals may have been produced. 

Wherever such waters act slowly upon limestones free sulphur with 

gypsum is likely to be formed.3 It must be observed, however, that 

the partial oxidation of hydrogen sulphide in presence of limestone 

would also produce the same association of substances. It is interesting to note that in a large crystal of gypsum from Cianciana, H. 

Sjogren 4 found a fluid inclusion which yielded liquid enough for 

analysis. Its composition resembled that of sea water, and the cavity 

also contained hydrogen sulphide.

The considerable deposits of sulphur found in western Texas are 

also associated with gypsum, and with waters which contain hydrogen sulphide. Some waters from the sulphur beds are strongly acid, 

and E. M. Skeats 5 reports one water which carried 1,360 parts per 

million, or 79.08 grains per gallon, of free H2S04 . The deposits are 

associated with limestones, which are sometimes bituminous, and at 

some points, as described by Richardson, gypsum has evidently been 

formed by alteration of the carbonate. At Cove Creek, in Utah, 

sulphur occurs in great quantities as an impregnation in rhyolitic 

tuff.6 It is derived from hydrogen sulphide of volcanic origin, and 

is also accompanied by strongly acid water. So far. as the sedimentary rocks are concerned, the association of limestone, gypsum, 

sulphur, and hydrogen sulphide seems to be quite general, although 

not absolutely invariable. The association of sulphur with petroleum 

or bituminous matter is also common.

1 Annales chim. phys., 4th ser., vol. 16,1869, p. 234. 

S 0p. cit.,p. 119.

8 Other examples are given by R. Brauns, Chemische Mineralogie, p. 366. L. Dieulafait (Compt. 

Rend., vol. 97,1883, p. 51), has suggested that polysulphides of calcium and strontium may assist in the 

formation of sulphur deposits.

* Bull. Geol. Inst. Upsala, vol. 1, No. 2,1S93. A similar inclusion was earlier described by 0. Silvestri, 

Gazz. chim. ital., vol. 12,1882, p. 2. 

6 Bull. Univ. Texas Mineral Survey No. 2, 1902. See also G. B. Richardson, idem, No. 9, 1904, p. 68. 

The sulphur deposits of Louisiana are described by L. -Baldacci, II giacimento solflfero della Louisiana, 

Rome, 1906. '

0 See W. T. Lee, Bull. U. S. Geol. Survey No. 315,1907, p. 485. For an earlier description, see G. vom 

Rath, Neues Jahrb., 1884, Band 1, p. 259.
SEDIMENTARY.,AND DETEJTAL ROCKS. 581 

CEUESTITE.

Celestite, the sulphate of strontium, SrS04 , is another mineral of 

the sedimentary rocks, which also occurs in Sicily with the gypsum 

and sulphur. It is one of the most characteristic minerals of the 

Sicilian deposits. In Monroe County, Michigan, according to 

E. H. Kraus and W. F. Hunt, 1 the celestite is found disseminated 

through dolomite, and the upper layer of the rock at the point 

especially studied contained over 14 per cent of the strontium compound. Below this layer there is a porous stratum, with cavities 

containing celestite and free sulphur. The latter is found in considerable quantities, and is evidently derived by reduction from the 

sulphate. Kraus 2 has also reported celestite as extensively disseminated through dolomitic limestone near Syracuse, New York. At 

Put-in Bay, Lake Erie, the limestones contain disseminated celestite, 

and caverns exist which are lined with crystals of that mineral.3 

The celestite here has evidently been leached out from the surrounding rocks and redeposited in the cavities. Although strontium sulphate is much less soluble than gypsum, it is more soluble than 

calcium carbonate, and therefore it may be dissolved away from the 

latter. In Transylvania, according to A. Koch,4 celestite and barite 

occur together in bituminous limestone. H. Bauerman and C. Le 

Neve Foster 5 report celestite in a nummulitic limestone in Egypt, and 

the crystals sometimes inclose fossil remains. It also appears as 

filling the interior of fossil shells, especially the chambers of nautili. 

At Condorcet, in France, as described by Lachat, celestite is found 

associated with gypsum in limestone.6

The original source of the strontium is undoubtedly in the igneous 

rocks, of which it is one of the commoner minor constituents. It is,' 

however, found in the ocean and in other natural waters, which serve 

as a secondary source.7 From such waters its compounds can be 

deposited directly, and they are also absorbed to some extent into' 

the skeletal parts of marine organisms. Strontium has been detected 

in the ashes of seaweeds, and O. Vogel 8 has found it spectroscopically 

in corals and molluscan shells. 0. Biitschli 9 has also found the 

skeleton of a radiolarian, Podactinelius, to consist almost entirely 

of strontium sulphate, a unique observation. From evidence of this

» Am. Jour. Sci., 4th ser., vol. 21,1906, p. 237. See also W. H. Sherzer, idem, 3d scr., vol. 50,1895, p. 246, 

and Michigan Geol. Survey, vol. 7, pt. 1,1900, p. 208.

a Am. Jour. Sci., 4th ser., vol. 18,1904, p. 30. On celestito deposits in California, see W. C. Phalen, Bull. 

U. S. Geol. Survey No. 540,1914, p. 521.

8 Kraus, Am. Jour. Sci., 4th ser., vol. 19,1905, p. 286.

« Min. pet. Mitt., vol. 9,1888, p. 416.

o Quart. Jour. Gool. Soc., vol. 25,1869, p. 40.

« Annales des mines, 7th ser., vol. 20,1881, p. 557.

' See ante, p. 181, for the analysis of a brine rich in strontium.

8 Zeitschr. anorg. Chemie,-vol. 5,1894, p. 55.

& Naturwiss. Wochenschr., vol. 6, 1907, p. 430. From Deutsch. Sudpol. Exped., Bd. 9, Heft 4.
582 DATA OF GEOCHEMISTRY.

kind J. V. Samoilov has suggested the possibility that some deposits 

of celestite may be of organic origin, although no specific instance of 

such a process is actually known.2

The carbonate of strontium, strontianite, is also deserving of mention here. At one locality near Barstow, California, a deposit of 

commercial importance exists, which has been described by A. 

Knopf.3 He regards it as having been formed by the replacement 

of limestone through the agency of water carrying strontium in 

solution.

BARITE.

Barite, barium sulphate, BaS04 , is closely akin mineralogically 

to celestite, but is more characteristically found in metalliferous veins 

than in bedded formations.4 Its occurrence as a cement in sandstones 

has already been noticed, 5 and it has also been observed as a sintery 

or even stalactitio deposit from spring and mine waters. 6

P. P. Bedson 7 found barium to be present in notable amounts in 

an English colliery water; and T. Richardson 8 has described a 

deposit of barite from a similar solution. Like deposits from other 

English collieries have been reported by F. Clowes, 9 who analyzed 

samples containing from 81.37 to 93.35 per cent of BaSO4 . The 

pipes carrying water from the mines which yielded these sediments 

were often choked by them, the barium sulphate being rarely absent 

and frequently their chief constituent. At Doughty Springs, in 

Delta County, Colorado, according to W. P. Headden,10 large masses 

of sinter have formed, consisting at some points of nearly pure 

barium sulphate, which at other.points is mixed with minor to dominant quantities of calcium carbonate. Bary tio sinters are also formed 

by a brine spring in a mine at Lautenthal, in the Hartz Mountains, 

and these have been carefully studied by G. Lattermann. 11 In this 

case they are precipitated by the mingling of the sulphate-bearing 

mine waters with the brine from the spring. Lattermann's analyses 

of the two waters, as stated by him in grams per liter, are as follows:

1 Mineralog. Mag., vol. 18,1917, p. 87.

2 For a long paper on celestite, with many references to the literature, see K. Andr6?, Ncuos Jahrb., 

Bell. Bd., vol. 36,1914, p. 373.

o Bull. U. S. Geol. Survey, No. 660,1918, pp. 257-270 (Bull. G60-I).

4 See L. Dieulafaifc, Compt. Rend., vol. 97,1883, p. 51.

& See ante, p. 536.

6 For the distribution of barium in waters, etc., see R. Delkeskamp, Notizbl. Ver. Erdkundo, 4thser., 

Heft 21,1900, pp. 47-83. On the distribution of barium and strontium in. sedimentary rocks, see I;. Collot, 

Compt. Rend., vol. 141,1905, p. 832.

' Jour. Soc. Chem. Ind., vol. 6,1887, p. 712.

3 Rcpt. Brit. Assoc., 1863, p. 54.

9 Proc. Roy. Soc., vol. 46,1889, p. 368.

»> Proc. Colorado Sci. Soc., vol. 8,1905, p. 1.

11 Jahrb. K.preuss.geol.Landesanstalt,18S8,p.259. A similar deposit of barium andstrontium sulphates 

from an English mine water is described by J. T. Durui, Chem. News, vol. 35,1877, p. 140.
SEDIMENTARY AND DETRITAL ROCKS.

, Analyses -of spring and mine waters at Laulcnlhal.

583

BaClo. ..................................................

SrCl,". .................................................

CaClo .................................................

MgCl,. ................................................

NaCL .................................................

KC1....................................................

MgS04 ................................................

ZiiS04 ........ ........................................

Spring.

0. 318

.899

10. 120

4.360

68. 168

.458

Mine water.

1. 515

.023

4.533

.652

.015

The barytic deposits from, these waters contain strontium, and 

appear in several forms as stalactites, as mud, and as incrustations. 

Analyses of them by Fernandez and Bragard show the subjoined 

proportions of the two principal ingredients.1

Barium and strontium sulphates in deposits at Lautentlial.

BaS04 ... ......................

SrS04 ........................

White stalactites.

84.81

12. 04

Brown stalactites.

83.88

8.64

Mud.

82.3

13. 4

Crusts.

92. 44

4.32

Similar mixtures of the two sulphates intermediate between barite 

and celestite are well known in crystalline form, and calc-iuin sulphate 

is often present also. A remarkable banded barite, from Pettis 

County, Missouri, described by C. Luedeking and H. A. Wheeler,2 

had the following composition:

Analysis of barite from Pcltis Counly, Missouri. 

BaS04 ......................................................... 87.2

SrS04 ..... 

CaS04 ..... 

(NH4)2S04 .

10. 9

.2

.2

2.4

100. 9

The presence of an ammonium salt in such a mineral is most 

unusual.

Barite often assumes nodular or concretionary forms. J. V. 

Samoilov,3 who has described many Russian localities, found tho 

mineral in characteristic nodules embedded in Jurassic marls or clays. 

He also cites several instances in which granules of barium sulphate

1 Complete analyses are given in the original memoir by Lattermann.

2 Am. Jour. Sci.,3d ser., vol. 42,1891, p. 495. The presence of ammonium salts was independent))' verified 

by tests in the laboratory of the United States Geological Survey.

s Mineralog. Mag., vol. 18, 1917, p. 87. On barite concretions ("barito dollars") in Nebraska, see J. B. 

Bumett, Nebraska Geol. Survey, vol. 7, pt. 15,1916, p. 105.
584 -- DATA OF GEOCHEMISTRY. ,

were found in the bodies of rhizopods, and, as in the case of celestite, 

he suggests.the possibility that some deposits of barite may be of 

organic origin. The nodules of barite dredged up from the bed of the 

ocean near Colombo, Ceylon, are possibly of that character. 1

Nearly or quite all of the occurrences of barite indicate that it is a 

mineral of aqueous origin. It may form as a direct deposit from 

waters, or as a precipitate when different waters commingle, or, as 

C. W. Dickson 2 has shown, by a reaction between solutions of barium 

bicarbonate and gypsum. Barium sulphate is also produced, according to Dickson, when the bicarbonate solution is brought into contact 

with oxidizing pyrite; arid its presence in limestones is attributed to 

a possible coincidence of the two reactions. The oxidizing pyrite is 

first instrumental in transforming calcium carbonate to sulphate, and 

the latter then undergoes double decomposition with the percolating 

barium solutions. The original source of the barium is in the feldspars and micas of the crystalline rocks, from which it is dissolved out 

during the ordinary process of weathering.

One very different occurrence of barite remains to be mentioned. 

In the Salem district of India T. H. Holland 3 found a remarkable 

network of veins consisting of quartz and barite, with about 70 per 

cent of the first mineral and 30 of the second. These veins are 

mostly in pyroxenic gneiss, and one cuts a dike of augite diorite, 

and Holland, for structural reasons, regarded the quartz-barite rock 

as a segregation from the original magma. This supposition, however, is chemically improbable. In a molten state quartz (or free 

silica) would react upon barium sulphate, to form a silicate and set 

sulphuric acid or sulphur dioxide free. Quartz and barite are magmatically incompatible.4

Various syntheses of crystalline barite are on record. One of the 

latest by Hilda Gebhart 5 is worth noting. Solid barium chloride 

was covered by a layer of gelatinous silica, over which a solution of 

a sulphate was placed, and the apparatus was allowed to stand undisturbed for eight or nine months. By slow diffusion of the sulphate 

through the intervening siliceous jelly definite crystals of barite were 

formed.

1 See E. J. Jones, ante, p. 134.

2 School of Mines Quart., vol. 23,1902, p. 363.

3 Rec. Geol. Survey India, vol. 30,1897, p. 236. See also L. L. Fennor, Rec. Geol. Survey India, vol. 42, 

1912, p. 226.

« On the genesis of barite see an important paper by G. B. Trener, Jahrb. K.-k. geol. Reichsanstalt, vol. 

S3, 1908, p. 387. This paper contains abundant literature references. On the barite deposits of Virginia, 

see T. L. Watson, Bull. Am. Inst. Min. Eng., 1907, p. 953. On barite in Missouri, W. A. Tarr, Univ. Missouri Studies, vol. 3, No. 1,1918. On the barite of the Hartz Mountains, G. Bentz, Zeitschr. prakt. Geologie, 

vol.22,1914, p. 281.

6 Min. pet. Mitt., vol. 29,1910, p. 185.
 SED1MENTAKY AND DETE1TAL EOCKS. 585 

FLUORITE.

Fluorite or fiuo'rspar, calcium fluoride, CaF2 , is also a common 

mineral in dolomites and limestones/ and it is often associated with 

galena and zinc blende. Crystals of it are found in limestone geodes, 

where it has evidently been deposited from solution. In some cases 

it may have been formed by fluoride solutions percolating through 

and replacing limestone. Its commonest occurrence is as a filling of 

veins. 2

1 See ante, p. 331, for an account of fluorite as a rock-forming mineral. Also p. 539 for fluorito as acemcnt 

JT> sandstones. For an exhaustive memoir on fluorite in sediments, see K. Andree, Min.pet. Mitt., vol. 

28,1909,p. 585.

2 For a description of the great fluorspar deposits in Kentucky and southern Illinois see S. F. Emmons, 

Trans. Am. Inst. MJn. Eng., vol. 21,1893, p. 31; H. F. Bain, Bull. U. S. Geol. Survey No. 255,1905; E. 0. 

Ulrich and W. S. T. Smith, Prof. Paper U. S. Geol. Survey No. 36,1905; and F. J. Fohs, Econ. Geology, 

vol. 5, 1910, p. 377. On the fluorspar of Derbyshire see W. M. Egglestone, Trans. Inst. Min. Eng., vol. 

35, 1908, p. 236; and C. B. Wedd and G. C. Drabble, idem, p. 501. The latter paper contains a good 

bibliography. On the fluorspar of San Koque, Cordoba, Argentina, see J. Valentin,. Zeitschr. prakt. 

Geologie, 1896, p. 104.
CHAPTER XIV.

METAMORPHIC ROCKS. 

METAMORPHIC PROCESSES.

In its widest sense the adjective metamorphic may be applied to 

any rock that has -undergone any sort of change. Practically, however, it is used to describe a well-defined class of rocks in which the 

transformation from an original form has been nearly complete. A 

slightly altered igneous or sedimentary rock is not commonly called 

metamorphic; neither is a mass of decomposition products so designated. The gneisses, the schists, quartzite, marble, and serpentine 

are the most familiar examples of metamorphism, and in each case 

an antecedent rock has been changed into a new rock by one or several among many different processes.1

Some varieties of metamorphism are entirely physical or structural, 

and therefore will not be considered in this memoir. Metamorphoses 

which represent only a development of slaty or schistose structure 

are of this kind. In most cases, however, metamorphism is accompanied by chemical changes, which are indicated by the production 

of new minerals, and this sort of metamorphism concerns us now. 

It may be regional, when large areas are affected, or a phenomenon 

limited to a contact between two reacting rocks, but these distinctions are of little significance chemically. The chemical phases of 

the process are all that we need to consider at present.

The reactions involved in metamorphism are not difficult to classify. 

The following changes are probably the most important:

1. Molecular rearrangements, as in the process of uralizatioii, 

when a pyroxene rock is changed into one characterized by amphibole.

2. Metamorphism by hydration. The conversion of a peridotite 

or pyroxenite into serpentine is a case of this kind, although something more than simple hydration is involved in the change.

3. Metamorphism by dehydration. The change of limonite to 

hematite and of bauxite to emery are good examples. Alterations 

of this class, however, are often more profound than dehydration 

alone can account for, especially when they take place at high temperatures. Then the molecules of hydrous minerals may be broken 

down, as when serpentine breaks up into olivine and enstatite, or talc 

into a metasilicate and quaitz.

1 On the application of physicochemical methods to problems of metamorphism, see J. Johnston and 

P. Niggli, Jour. Geology, vol. 21, pp. 481,588,1913. The paper is essentially theoretical, with few references 

to specifically geologic phenomena.

586
METAMOBPHIC ROCKS. 587

4. Oxidations and reductions, which affect chiefly the iron oxides 

of the rocks. Ferrous compounds become ferric, and hematite, on 

the other hand, may be reduced to magnetite.

5. Changes other than hydration, produced by percolating solutions. Cementation is one process of this kind, and the change from 

sandstone to quartzite is a common example of it. In other processes 

the solutions effect chemical transformations, and develop new compounds. The dolomitization of limestone is a case in point.

6. Metamorphism by the action of gases and vapors, the so-called 

''mineralizing agents." These agents generate new minerals within 

a rock, and like solutions introduce new constituents.

7. Metamorphism by igneous intrusions. This heading covers the 

changes due to the intrusion of molten matter into or between rock 

masses, whereby a class of "contact minerals" is formed.

Although this classification is simple, it is only superficially so. 

It is useful as a matter of convenience, but its application to concrete 

examples of rnetamorphism is not always easy. Two or more processes may operate simultaneously, or they may shade into one another, with all sorts of variations in detail due to variations in temperature and pressure. All of these considerations must be borne in 

mind in dealing with the actual phenomena of nietamorphism. The 

ideal simplicity is not often found.

In the study of metamorphic'phenomena the conceptions developed 

by C. R. Van Hise l are also helpful. Van Hise divides the lithosphere into two zones an upper zone of katamorphism and a lower 

of anamorphism. The zone of katamorphism is furthermore subdivided into two Kelts one the belt of weathering, the other that of 

cementation. These approximately concentric shells are characterized by definite chemical differences, which may be briefly summarized as follows:

The uppermost shell of all,, the belt of weathering, extends from 

the surface of the ground to the level of the ground water, and its 

thickness is very variable. It is essentially the region of rock decomposition, and its reactions are mainly those of hydration, oxidation, 

absorption of carbonic acid with liberation of silica, and losses of 

material by leaching. It is also a region of low pressure, relatively 

low temperature, and great porosity. In it the complex silicates 

are broken down into simpler compounds, from which, within the 

belt, they are rarely regenerated.

The belt of cementation is that which contains the ground water. 

Its rocks are more or less porous and fractured, its temperature is 

still not high, but the pressure is great enough to play an important 

part in the reconsolidatioii of sedimentary material. It is, in short, 

the birthplace of such rocks as shales and sandstones. In the belt

1 A treatise on metamorphism: Mon. U. S. Geol. Survey, vol. 47,1904.
-.DATA OF GEOCHEMISTRY.

above it solution is a-leading process, but here, in the accumulated 

ground water, redeposition rules. Hence its name, the belt of cementation.

In the zone of anamorphism, which lies below the region of the 

ground water, the rocks are no longer distinctly porous. The pressure above them tends to close up all pores and fractures. The temperature is also relatively high that is, below the melting point of 

the rocks, but possibly above the critical temperature of water. 

Under these conditions the reactions of the upper zone are reversed. 

Instead of hydration, there is dehydration; reduction is more common than oxidation; carbonates are decomposed and silicates are 

regenerated. Pneumatolytic reactions are characteristic of this 

region, and so too are metasomatic changes. There is also a tendency 

to the development, under pressure, of the heavier and denser rockforming minerals, and of the species which contain constitutional 

water, fluorine, or boric oxide. Garnet, staurolite, muscovite, epidote, and tourmaline are, for example, typical minerals of the metamorphic rocks. 1

According to C. K. Van Hise, the minerals of the upper zone are 

those which are formed with increase of volume and evolution of 

heat. In the lower zone, contraction and absorption of heat occur. 

These distinctions, of course, are general, not absolute, and should 

only be accepted in a broad way. They stand for prevailing tendencies, to which many exceptions are possible. Nor can the belts 

and zones be rigorously delimited, for they shade into and even 

interpenetrate one another. Material formed in the belt of weathering is covered up by sediments and presently finds itself within the : 

belt of cementation. Still later, covered more deeply> it may pass 

into the zone of anamorphism. So also, by erosion, a part of the 

anamorphic zone may be uncovered and brought within the realm 

of weathering. To all these changes chemical changes correspond,, 

so that the same mass of material can be metamorphosed, in opposite 

directions, over and over again. A clay becomes a shale; that is 

transformed into a schist or gneiss, and that again may pass back 

into clay. The phenomena of decomposition, of reconsolidation, and 

of recrystallization form parts of a cycle of changes which are recognized mainly by their interruptions. The definite products to which 

we give definite names represent temporary stoppages or periods of 

slow change in the progress of the cycle.

In both zones of the lithosphere water is the chief agent of chemical metamorphism. It is most abundant in the zone of katamor1 According to G. Spezia (Atti Accad. sci. Torino, vol. 46, p. 682; and Chem. Abstracts, vol. 6, p. 2587, 

1912) the views of Van Hise relative to the influence of pressure are untenable. For instance, limonite, 

held for 8 months under a pressure of 8,000 atmospheres was not dehydrated. Neither, under 7,000 atmospheres, was aragonite transformed to calcite. For a general discussion of the effect's of pressure on the 

physical and chemical relations-of solids, see J. Johnston and L. H. Adams, Am. Jour. Sci., 4th ser., vol. 

35, 1913, p. 205. On high pressure investigations see Johnston, Jour. Franklin Inst., Jan., 1917.
METAMOEPHIC ROCKS. 589

pMsmj where it acts mainly as a liquid and fills more or less completely the pore spaces of the rocks. In the zone of anamorphism 

water is much less abundant and operates in the subcapillary and 

intermolecular spaces, where, because of the higher temperatures, it 

is probably present, at least for the most part, as vapor. At a depth 

of about 10 kilometers the critical temperature of water is likely to 

be reached, and its chemical activity should then be very high. The 

well-known corrosive action of superheated steam upon glass is an 

illustration of this point. Even when the water is still liquid, at 

temperatures of over 200°, it may form a fluid or pasty mass with 

some silicates, as shown by C. Barus 1 in his experiments upon 

aqueo-igneous fusion.

In the zone of katamorphism the water is moving freely, percolating from place to place. In the lower zone its mobility must be 

much diminished, so that on a given particle of rock it acts for a 

longer time. It may appear in this zone, according to Van Hise, in 

three ways as water held by buried sedimentaries, as water liberated 

from hydrous compounds by heat or pressure, and as magmatic water 

contained in igneous intrusions. But from whatever source it may 

bo derived, its chemical functions are the same. It acts as a solvent 

upon practically all the rock-forming minerals; it therefore transfers matter slowly from point to point and in that way assists in 

bringing about recrystallization. In so doing the water is partly 

taken up into the molecules of new compounds, such as staurolite, 

epidote, mica, and tourmaline, of which it forms a constitutional 

part and from which it can only be expelled at temperatures approaching or even exceeding a red heat. Loosely combined water 

thus becomes firmly combined water and ceases for the time being to 

be further active. A reference back to the chapter upon rock-forming minerals will show how many syntheses have depended upon 

heating the constituent substances with water under pressure. The 

minerals thus formed are characteristic of the zone of anamorphism, 

even though they are not confined to it. 2

The sediments, as a rule, contain organic matter. When they 

reach, by burial, the high temperatures of this zone, the organic 

matter is decomposed, yielding free carbon, carbon dioxide, nitrogen, 

and water. The free carbon may appear in the metamorphosed rocks 

as amorphous particles or it may be recrystallized into graphite; the 

carbon dioxide may escape, working its way slowly upward, or it may

» See ante, p. 291.

a In addition to works already cited, the following papers which have appeared during recent years en 

hydrothermal syntheses deserve notice: E. Baur, Zeitschr. anorg. Chemie, vol. 72, 1911, p. 119. \V. T. 

Muller and J. Konigsberger, Zeitschr. angew. Chemie, vol. 25,1912, p. 1273, and Zeitschr. anorg. allg. Cheniic, 

vo].. 104,1918, p. 1. - P. Niggli, Zeitschr. anorg. Chemie, vol. 84,1913, p. 31. G. W. Morey and P. Niggli, Jour. 

Am. Chem. Soc:, vol. 35; 1913; p. 1086.- M-. Sclilaeppfer.and'P. Niggli, Zeitschr. anorg.[Chemie, vol. 87,1914, 

p. 52. E. Ai.Stephonson,-'Jour. Geology, vol. 24,1916, p. ISO.
590 DATA OF GEOCHEMISTRY.

be caught and inclosed within crystals of quartz or other minerals. 

Inclusions of this kind are common, and so also are inclusions of 

free carbon.

In this process of decomposition the organic matter of the sediments acts as a reducing agent, transforming ferric to ferrous compounds. When magnetite is thus formed from limonite, the reduction 

is partial, but when the iron compounds of a clay are metamorphosed 

into staurolite or tourmaline, the change from ferric to ferrous is 

nearly or quite complete. It must not be assumed, however, that 

organic matter is the only reducing agent during metamorphism. 

We have seen in a previous chapter that hydrogen may be either 

occluded in or generated from heated rocks, 1 and its activity as a 

reducer may be very great. But on this point, geologically speaking, 

there is little positive knowledge. We are compelled to deal, more 

or less, with reasonable inferences.

By the action of the heated waters much silica is liberated, which 

recrystallizes in part as quartz. Some of it, however, attacks the 

limestones of the buried sedimentaries, liberating carbon dioxide and 

forming silicates, such as wollastonite. When, however, a large mass 

of fairly pure limestone or dolomite reaches the anamorphic zone, it 

is recrystallized into marble. This change, and also the formation 

of dolomite, was considered in detail in the preceding chapter, where 

the subject was perhaps out of place. Some of the concomitant 

changes will be discussed later.

One great distinction between the two zones remains to be noted. 

In the belt of weathering the transfer of material from point to point 

both by mechanical and by chemical means, is a conspicuous feature. 

In the belt of cementation the mechanical transfers become less prominent, but the moving waters carry much matter long distances in 

solution. In the zone of anamorphism the mechanical movements 

become relatively insignificant and the chemical changes are practically effected in place that is, the chemical movements of matter 

within the lower zone are only through trifling distances, and the 

transformations are effected with material close at hand. The upper 

zone is, then, emphatically a zone of mobility; while the material of 

the lower zone, being under great pressure, is comparatively immovable. I speak now, of course, of certain kinds of movement; the 

motions of the earth's crust, its upheavals and depressions, the displacing influence of igneous intrusions, etc., are phenomena of a different order. Neither do I use the terms movable and immovable 

in any absolute sense, for they have only a relative meaning. The 

freedom of motion in the upper zone is vastly greater than in the 

lower; and because of that fact the phenomena of the two zones 

become strongly contrasted.

1 See ante, pp. 2G8 et seq., for the experiments of Tilden, Travers, Gautier, etc.
METAMOBPHIC ROOKS. 591

 CLASSIFICATION.

The classification of the metamorphic rocks is not a simple matter. 

The criterion of structure is not sufficiently general, and that of 

genesis is too vague. We can not always determine the genesis of 

a given rock, and when we are able to do so, the result, for purposes 

of classification may be unsatisfactory. A gneiss can be derived 

from an igneous rock or from one of sedimentary origin, the product 

being sensibly the same in both cases. It is possible, of course, to 

classify these rocks on the basis of their composition; but here again 

there are difficulties, even greater, perhaps, than those which becloud 

the classification of purely igneous material.1 Quite dissimilar rocks 

may have very similar composition. In fact, no single classification covers all the ground; for the phenomena of nature do not 

arrange themselves in linear sequence.- They form an irregular network of interlacing lines, with all manner of intersections and frequent disturbances.

Taking all of the difficulties into account, I prefer to study the 

metamorphic rocks, so far as may be practicable, with reference to 

the chemical processes which have governed their formation. I have 

already stated that several processes may take part in a single 

metamorphosis; but in many cases one process predominates. The 

conspicuous process, then, gives a basis for classifying our data 

which need not, however, exclude other arrangements for other purposes. The method supplements, but does not supplant its rivals. 

For convenience we may also divide the metamorphic rocks into three 

classes, as follows: First, those derived from igneous rocks; second, 

those of sedimentary origin; third, rocks formed by contact reactions between the igneous and the sedimentary.

The metamorphism of the igneous rocks is commonly a deep-seated 

phenomenon; that is, its conspicuous examples are formed in the 

zone of anamorphism, or under anamorphic conditions. Leaving 

mechanical or structural changes out of consideration, its conspicuous feature is of the order of a molecular rearrangement; in other 

words, the older minerals are transformed into new species, sometimes by simple paramorphism and sometimes with transfer of 

material from one molecule to another. In general, as F. Becke 2 

has shown, the rearrangements are attended by decrease of volume, 

the product of the change being denser than the original material. 

For example, in the special case chosen by Becke, the plagioclase and

i U. Orubenmann (Die Kristallinen Sclliefer, Berlin, vol. 1, 1904; vol. 2, 1907) hcs attempted to forma 

chemical classification of the schists, which resembles Osann's discussion of the igneous rocks. A second 

edition of Grubenmann's book in one volume appeared in 1910. The references in this work are to tho 

first edition. On motamorphic rock series see P. Niggli, Min. pet. Mitt., vol. 31,1912, p. 477. See also O.K. 

Lcithand AV. J. Mead, Metamorphic geology, New York, 1915; YT. J. Miller, Bull. Geol. Soc. America, 

vol. 23,1917, p. 451; and R. A. Daly, idem, p. 375. Daly gives abundant references to literature.

* Ncues Jahrb.. 189P, Band 2,,p. 182.
592 DATA OF GEOCHEMISTRY.

orthoclase of a rock containing a little water were transformed into 

a mixture of albite, zoisite, muscovite, and quartz, the volume reduction being in the ratio of 547.1:462.5, a loss of over 15 per cent. 

A number of similar condensations are cited by U. Grubenmann;* 

and although the calculations are necessarily crude, they are none 

the less conclusive.2 The fact that they are exceptions to the rule 

does not destroy its general validity. ' . From a mineralogical point of view, the more noteworthy metamorphoses within the igneous rocks may be classified under the 

following headings: .

1. Change of pyroxene to amphibole.

2. Change of feldspar to mica.

3. Change of feldspar to zoisite.

4. Change of feldspar to scapolite.

5. Formation of epidote.

6. Formation of garnet.

7. Change of hornblende to chlorite.

8. Segregation of albite from plagioclaee.

9. Formation of serpentine. 

10. Alteration of ilmenite.

This schedule is by no means exhaustive, for many other minor 

changes are to be observed in the metamorphism of igneous rocks. 

Every primary mineral that they contain may give rise to secondary 

species, and these represent all orders of transformation from the 

slightest modification to the complete molecular breaking down 

which is seen in the processes of weathering. Decompositions, however, are not now under discussion; we are dealing with the phenomena of recrystallization within rock masses, excepting, of course, 

the case of serpentinization, which is a process of a different order.

TJRALITIZATION.

The alteration of pyroxene rocks into hornblende rocks is one of 

the best-established metamorphoses. The hornblende thus produced, 

.when fibrous, is known as uralite, and the change is called uralitization.3 It is often accompanied and complicated by other changes, 

such as the formation of epidote or zoisite, and it may also be coincident with the development of a schistose structure. Mediosilicic and 

subsilicic rocks, like gabbro and diabase, are thus metamorphosed into 

amphibolite or hornblende schist. An excellent example of this sort 

of change was found by J. J. H. Teall 4 in a dike at Scourie, Suther-

» Die Kristallinen Schiefer, Berlin, 1904, pp. 34-38. Grubenmann's data are taken from a paper by 

F. Becke, in Compt. rend. IX Cong. geol. internat., 1903, p. 553. See also F. Loewinson-Lessing, Studien 

liber die Eraptivgesteine: Compt. rend. VII Cong. ge"ol. internat., St. Petersburg, 1897. 

2 For a tabulation of the volume changes attending the alteration of minerals, see C. E. Van Hisc, A 

treatise on metamorphism: Mon. U. S. Geol. Survey, vol. 47,1904, pp. 397-408.

3 See G. H. Williams, Bull. U. S. Geol. Survey No. 62, 1890, p. 52, for a full discussion of this subject 

accompanied by abundant references to literature. See also L. Duparc and T. Hornung, Compt. Rend., 

vol. 139,190-1, p. 223, on a theory of uralitizaticn.

« British petrography, 1888, p. 198; also in Quart. Jour. Geol. Soc., vol. -11, 1885, p. 137.
METAMORPHIC EOCKS. 593

landshire, Scotland, where a dolerite had changed , first into a massive hornblende-bearing rock and later into a schist. The following 

analyses will serve to illustrate the character of the changes thus 

produced:

Analyses of pyroxene rocks before and after alteration.

Aa. The plagioclase-pyroxene rock of the Scouric dike. 

Ab. The derived hornblende schist. Analyses A by Teall, loo. cit. 

Ba. Pyroxene from the center of a crystal, Tcmpleton, Canada. 

B b. Intermediate portion of the same crystal.

Be. Hornblende forming the rim of the crystal. Analyses B by B. J. Harrington, Geol. Survey Canada, 

 Hoc. of Progress, 1877-78, p. 21 G.

Ca. DiaUage from a gabbro, Transvaal, South Africa.

Cb. Urah'te from alteration of the diallage. Analyses C by P. Dahms, Ncues Jahrb., Boil. Band 7,1891, 

p. 99.

Si02 . ......................

A1203 .. ......................

FeA. .....................

FeO. .......................

MnO.......................

MgO..... .......... ..........

CaO.......................

NaoO......................

KaO..... ...................

H O

Tf02 .... ....................

C0a ............... .........

Specific gravity. .............

Aa.

47.45

14. 83

' 2.47

14.71

5.00

8.87

2.97

nq

1.00

1.47

.36

100. 12 

3.10

Ab.

49. 78

13.13

4.35

11.71

5.40

8.92

2.39

1.05

1.14

2.22

.10

100. 19 

3.10

Ba.

50.87

4.57.

.97

1.96

.15.

15.37

24.44

.22

.50

a 1.44

100. 49 

3. 181

Bb.

50.90

4.82

1.74

1.36

.15

15.27

24.39

.08

.15

a 1.20

100. 06 

3.205

 Be.

52. 82

3.22

2.07

2.71

.28

19.04

15.39

.90

.69

a 2. 40

99.52 

3.003

Ca.

53.53

3.12

5.09

13.54

18.77

6.19

.50

.20

101. 01

Cb.

52.73

4.70

5.26

10.21

12. 59

12.58

.23

.06

1 54

99.90

a Loss on ignition.

That the change from pyroxene to uralite or amphibole is something 

more than a paramorphism these few analyses clearly show. In A 

there has been oxidation of ferrous to ferric iron, in B a loss of lime, 

and in C a loss of magnesia. In many cases uralitization is accompanied by a separation of magnetite,1 and the lime removed reappears 

as calcite. Epidote is also a common product during the process, 

which must vary with variations in the composition of the altering 

rock and of the individual pyroxene. Augite thus yields hornblende 

or actinolite; diopside may change into tremolite, and from the soda 

pyroxenes the aluminous glaucophane may be derived. The composition of the pyroxene is reflected in that of its derivative, but 

the augite-hornblende change is the most common.2 Between the 

original igneous rock and the secondary amphibolites there are all 

possible intermediate gradations, from incipient change to complete 

transformation. 3

' See G. Rose, Zeitscbr. Deutsch. geol. Gesell., vol. 16,1864, p. 6; E. Svedmark, Neues Jahrb., 1877, p. 99. 

2 See discussion of the change by C. H. Gordon, Am. Geologist, vol. 34,1904, p. 40. 

8 On the transformation of basic eruptives into amphibolite see A. Lacroix, Compt. Rend., vol. 164, 

1917, p. 969.

113750° 19 Bull. 695 38
DATA OF GEOCHEMISTRY. 

GLAUCOPHANE SCHISTS.

The glaucophane schists differ from the amp-hiboKtes in that they 

contain the soda amphibola instead of hornblende. H. S. Washington * divides these rocks into three classes, namely, epidoteglaucophane schist, mica-glaucophane schist, and quartz-glaucophane 

schist; but he also recognizes the fact that there are many transitional varieties. W. H. Melville^ for example, has described a 

garnet-glaucophane schist from Mount Diablo, California, and 

A, Wichmann 3 an epidote-mica-glaucophane schist from Celebes. 

A zoisite-glaucophane schist from Sulphur Bank, California, is also 

mentioned by G. F. Becker.4 It consists chiefly of glaucophane and 

zoisite, but quartz, albite^ spnene, and muscovite are also present. 

Another rock from Piedmont, containing glaucophane, garnet, 

hornblende, epidote, mica, and sphene, described by T. G. Bonney,5 

is called a glaucophane eclogite.

Geneticaly, the glaucophane rocks differ widely. Some of them 

are undoubtedly derived from mediosilicic or subsilicic igneous 

rocks; others from sedimentaries. In Greece, for example, according to R, Lepsius,6 some glaucophane schists represent gabbro and 

others are metamorphosed Cretaceous shales. "The epidote-glaucophane schist of Anglesey, Wales, described by J. F. Blake,7 was 

originally a diorite, and in this rock alterations of glaucophane to 

chlorite occur. In Piedmont, as described by S. Franchi,8 there are 

glaucophane rocks associated with amphjbolite, both, having been 

derived from diabase.. In Japan, according to B. Koto, 9 the metamorphosed material was formerly a diabase tuff, and the glaucophane 

was derived from diallage. By further alteration the glaucophane 

sometimes passes into crocidolite. And on Angel Island, in San 

Francisco Bay, California, a glaucophane schist studied by F. L. 

Ransome 10 has been developed from a radiolarian chert, probably 

by contact metamorphism. In many cases the genesis of thescrocks is obscure; but Washington suggests that the epidote-glaucoLAm. Jour. Sci., 4th ser., vol. 11,1901, p. 35. This memoir is a very complete summary of our knowledge 

up to its date of these rocks. It contains many analyses and abundant references to literature. See-also 

1C. Oebbeko, Zeitschr. Deutsch. geol. Gesell., vol. 38,1886* p. 634;. U. Qrubenmann, Eoscnbusch " Festschrift," 1906; E. H. Nutter and W. B. Barber, Jour. Geology, vol. 10,1902, p. 738; and J. P. Smith, Proc. 

Am. Philoa. Soc., vol. 45", 1906,. p. 183. The last two papers relate to the glaucophane rocks of California. 

Other.noteworthy papers are by E. Murgoci,. Bull. Dept. Geology Univ. California, vol. 4, 1906, p. 359; 

L. Milch, Neues Jahrb., Festband, 1907, p. 348; and T. J. Woyno, Neues Jahrb., Beil. Band 33,1911, p. 136.

* Bull. Geol. Soc. America, vol. 2,, 1890,, p. 413.

s Neues Jahrb., 1893, Band 2, p. 176.

4 Mon. U. S. Geol. Survey, vol. 13, 188S, p. 104'.

s Miueralog. Mag., vol. 7, 1887, p. 1,

o Geologic vou Attika, Berlin, 1893, pp. 102,133.

' Geol. Mag., 1888, p. 125.

sBoI. Com. geol. itaf., vol. 26,1895, p. 192.

9 Jour. Coll. Sci. Japan, vol. 1,1886, p. 85.

10 Bull. Dept. Geology Univ. California, vol. 1, p. 211.
METAMOKPH-ie ROCKS. 595

phane schists represent originally gabbroid magmas, while the 

quartz-glaucophane schists are metamorphosed quartzites or 

quartzose shales. For convenience differences of origin will be 

disregarded here and the analyses of this group of rocks are tabulated 

together, as follows:

Analyses of amphibolites and glaucophane schists.®

A. Amphibolite dike,, Palmer Center,-Massachusetts..

B. Amphibolite bed, Palmer Center. Analyses A and B, by W. F. HUlebrand, Bull. U. S. GeoK 

Survey No. 228,1904,,p. 36..

C. Amphibolite, CrystalFalls district, Michigan. Described.by.H. L. Smyth, MOD. U. S. Gcol. Survey, 

vol. 36,1899, p. 397. Analysis by H. N. Stokes. Probably derived from a diabase or'basalt. Contains 

hornblende, plagioclaso, biotite,. and. quartz,, with a httlo. rutile and magnetite.

D. Epidote-glaucophane schist, Mount Diablo, California.. Analysis.by W. H. Melville, Bull. GcoL 

Soc. America, vol. 2,1890, p. 413. Contains garne.ts. Possibly derived from shale.

 E. Garnet-glaucophane schist, Bandon, Oregon.. Analyzed and described by H. S. Washington, A'm. 

Jour. ScL, 4th ser.,. vol.. 11, 1901,. p. 35.. Contahis glaucophane, epidoto or zoisite, garnet, and white 

mica.

F.. Zbisite-glaucophanc schist, Sulphur Bank,. California.. Analysis- by Melville. Described by O. F. 

Becker, Mon. U. Si. Geol..Survey, vol..l3,,1888,.p.,104.

G. Mica-glaucophano schist, Island of Syra, Greece. Analyzed and'described by Washington, loc. cit.

H. Quartz-glaucophane schist, Fourmilo Creek, Coos County, Oregon. Analyzed and described, by 

Washington. Contains quartz, glaucophane, chloritc, muscovitc, and. garnet.

SiO...... .............

A1203 ..... ............

1<V> O

FeO................

MgO.......... ........

CaCK.. ............... -

Na,0........ ........ ICOHto............... &Q+. .............

TfO

G02 .. ................

Pa06 ......... ........ s!. .................

V203 ................

Cr203 .... ............

MO.3................

MnO.. ......... ......

SrO... ...............

BaO................. Li;,o.................

A

49. 57'

14. 23

3. 95-

8.01

6. 14

10. 19

3.06

.95

, .14.

1.33

2.03

Trace,

.21

.02

.04

Trace:

Trace.

.27

Trace?

Trace.

100. 14

B

51. 25

16. 53

1.81

7.67

5.87'

9.32

3.35

.78

.19

1.26

1 84

.3!

(?)

Unclet.

Trace.

Trace,

.28

C?)

J?)

Trace?

100. 46

C

50.36

13. 26

6. 30;

9,34

5.55

7.85.

2.11

1.14

1.55

1.55

1 77

.20

Trace.

99.59

D

47.84

16.88

4.99

5.56

7.89

11. 15.

3.20

.46

.17

1.81

.14

........

.56

100. 65

E.

49.15

15.87

410

7.58

7.53

9.06

3.59

.54

.16

1.07

1.19

Trace.

99.84

E

49.68

13. 60

186.

8.61

6:26

10.97

3.09

.12

| 3. 84

1. 31

.21

.04

99.59

G

58.26

16.21

3:44

4.63

4.99

3. 82

5.36

.39

\ .22-

/ .98

1.37

Trace.

99.67

IL

82.53

6.88

.59

4.11

1.86

.68

1.21

1 24

.07

135

'

Trace

100. 52

<J-A number of amphibolites from Massachusetts are described by B. K. Emerson in Mbn. U. S. Geol.

analyses of amphibolites from the Tyrol. See also a table of analyses in Rosenbusch, Elcmente der Gesteinslehro, p. 632. See also, on amphibolite, F.Backe,Min. pet. Mitt., vol.4,1882,p. 285: and Ji A. Ippea> 

Mitth. Naturwiss. ^7er. Steicrmark, 1892,p.328. Ippendescribes"normalamphibolitc/'andalsozoisite, 

pyroxene, feldspar, and garnet amphibolite. On amphibolite produced by the intrusion ol grauitu into 

_« limestone see F. D. Adams, Jour. Geology, vol. 17,1909, p. 1.
596 tfATA OF- GEOCHEMISTRY.

jSERICITIZATION. _

The conversion of feldspar into muscovite is one of the commonest processes of metamorphism, whether of igneous or of sedimentary 

rocks. In many instances the mica produced is the compact or fibrous -~~ 

variety known as sericite, which, in former times, was generally mistaken for talc. The so-called talcose schists of the earlier geologists 

have proved in most cases to be not talcose, but sericitic.1 The iden- w 

tity of sericite with muscovite was finally established by H. Laspeyres 2 in 1880, and since then its occurrence has been repeatedly 

investigated. The alteration is most conspicuous in regions where "~ 

the dynamic metamorphism has been most intense high temperature, the chemical activity of water, and mechanical stress all working together to bring it about. Any feldspathic rock may undergo *~ 

sericitization, but orthoclase rocks furnish the most typical examples. The derivation of sericitic schists and gneisses from granite, 

quartz porphyry, and diabase, and also from arkose and clay slate, > 

has been repeatedly observed.3

Sericite is commonly derived from orthoclase or microcline as, 

suggested above, but may be generated from plagioclase feldspars ^ 

also, the reactions in the two cases being different. In the formation of muscovite from orthoclase the necessary potassium is already 

present; but in order to produce muscovite from plagioclase a replacement of sodium by extraneous potassium is required. In either case 

the reaction which takes place may be represented by more than one " 

equation, although it must be admitted that the formulation is purely ^ 

hypothetical. Until the processes shall have been experimentally ^ 

reproduced the equations will remain doubtful.

First, orthoclase may be transformed to muscovite by the addition 

of colloidal alumina equivalent in composition to diaspore, thus:

KAlSi308 + 2A10.0H = KH2Al3Si3012 .

" This reaction is very simple chemically, but geologically improbable. \ 

It requires the presence of solutions containing much alumina, and it w 

is not easy to see whence they could be derived. It suggests, however, 

a possible relation between the formation of sericite and the 

alteration to bauxite, a possibility which deserves further investi- ^ 

gation.

A second, more probable, and even simpler reaction is the following:

3KAlSi3O8 + HaO = KH2Al3Si3012 + K2SiO3 + 5Si02 . " ^

» See G. H. Williams, Bull. U. S. Geol. Survey No. 62,1890, pp. 60-62, for historical details. . 

2 Zeitschr. Kryst. Min., vol. 4,1879, p. 245. _____ 

8See J. G. Lehmann, Untersuchungen iiber die Entstehung der altkrystallinischen.Schiefergestcine, 

Bonn, 1884; A. Wichmann, Verhandl. Naturhist. Ver. preuss. Rheinlande u. Westfalens, vol. 34,1877, p. 1; A. 

von Groddeck, Neues Jahrb., Beil. Band 2, 1883, p. 72; C. Schraidt, idem, Beil. Band 4,. 1886, p. 428, and 

0. Benedicks, Bull. Geol; Jnst. Upsala, vol. 7, 1904-5, p. 278. In Jahrb. K. preuss. geol. Landesanstalt, 

1885, pt. 1, Von Groddeck describes the derivation of sericite schists from clay slates. ^
METAMOBPHIC BOOKS. 597'

In this case water alone, acting on orthoclase at a high temperature 

and under pressure, forms muscovite, free silica, and potassium silicate, the last compound being leached away. The liberated silica 

may be partly removed in solution, or it can recrystallize as quartz, 

a mineral which almost invariably accompanies sericite in metamorphic rocks. Furthermore, the analyses of sericite usually show a 

small excess of silica over that contained in normal muscovite. A 

similar reaction with albite should yield the soda mica paragonite.

A modified form of the last reaction is in common use, which involves the introduction into the equation of carbonated water, as 

follows:

3KAlSi308 + H2 0 + C02 = KH2Al3Si3012 + K2C03 + 6Si02 .

In this case, however, the potassium carbonate would dissolve one 

molecule of the liberated silica, forming potassium silicate as before. 

The C03 would thus be set free again, ready to assist in further alterations of feldspar. Since carbonated waters, both of meteoric and 

of deep-seated origin, are very abundant, it is quite possible that 

this regenerative process is really in operation. If so, the reaction 

should be more vigorous than when water acts alone. The frequent 

association of calcite with sericite is an indication that carbonated 

solutions have helped to produce the change.1 If the alteration took 

place in presence of both albite and orthoclase, the potassium silicate 

would probably react upon the former mineral or upon its incipient 

decomposition products, so that muscovite only, without paragonite, 

would be formed. In the development of muscovite from plagioclase the presence of potassium-bearing solutions, which exchange 

alkalies with the sodium compounds, must be assumed. It is also 

probable, as shown by S. Paige and G. Steiger 2 that fluorine often 

plays an important part in sericitization.

OTHER ALTERATIONS OF FELDSPAR.

Apart from the phenomenon of sericitization, the plagioclase feldspars undergo a number of other metasomatic changes, whose records 

are preserved in the metamorphic rocks. Under the influence of 

carbonated waters the anorthite molecule may be decomposed, with 

the formation of calcite and the separation of silica. In this case the 

albite remains as a finely granular aggregate, the so-called "albite 

mosaic," which outwardly resembles quartz and with which quartz 

is commonly associated.3 When the lime of the anorthite is not com1 Compare W. Lindgren, Trans. Am. Inst. Min. Eng., vol. 30,1900, p. 608, in reference to the association 

with.calcite. See also A. F. Rogers (Econ. Geology, vol. 11, 1916, p. 118) on the hydrothermal origin of 

sericite. . .......

2 Jour..Washington Acad. Sci.,.vol. 8,1918,.p..234.

8 See K. A. Lessen, Jahrb. K. preuss., geol. Landesanstalt, 1884, pp. 525-530. See also 0. H. Williams, 

Bull. U. S. Geol. Survey No. 62,1890, p. 60.
\

598 DATA OF GEOCHEMISTRY.

pletely removed, it goes to form other silicates, such as epidote, zoisite, or actinolite. The latter reactions are by far the most frequent. 

The alteration of plagioclase to zoisite is exceedingly common, but 

it is rarely complete. As a rule mixtures of zoisite and feldspar 

remain, which were once thought to represent a distinct mineral species and to which the name saussurite was given. The mechanism of 

the change is obscure, but it is probably a double decomposition 

between the albite and anorthite molecules, brought about by the 

intervention of water. The feldspars, however, vary in composition; 

the water may contain other reacting substances in solution, and so 

the reactions are complicated in many ways. The following equation, which is plausible but not proved, represents the transformation of plagioclase into a mixture of zoisite, paragonite, and quartz, 

a mixture that sometimes occurs:

NaAlSi3O8 + 4CaAl2Si208 + 2H20 = 

Albite. Anorthite. Water.

2Ca2HAl3Si3 013 + H2NaAl3Si3O12 + 2SiO2 . 

Zoisite. Paragonite. Quartz.

When orthoclase molecules are present, muscovite will be formed; 

that is sericitization and saussuritization may go on together. With 

albite in excess, the saussurite mixture appears, but that again is 

variable. It may contain epidote, scapolite, or garnet; according 

to A. Cathrein,1 saussurite is sometimes derived from garnet; and all 

of these minerals may undergo complete or partial alterations into 

other compounds.

Saussuritic rocks have been described by many petrographers, 

and there is abundant literature covering them. F. Becke 2 reports 

a saussurite gabbro from Greece, consisting of saussurite and diallage, the latter partly altered to hornblende. P. Michael 3 describes 

another saussurite gabbro from Germany, in which garnet is also 

present, derived from diallage and partly altered to serpentine. 

Another saussurite gabbro from Sturgeon Falls, Michigan, was carefully studied by G. H. Williams.4 It contained saussurite derived 

from the complete alteration of plagioclase, diallage, hornblende 

partly secondary, and a little ilmenite, with some calcite, quartz, 

and a colorless chlorite. By further alteration this rock passes into 

a silvery schist, consisting mainly of chlorite, calcite, and secondary 

quartz, but with some feldspars remaining, partly sericitized. A 

rock designated as a zoisite-hornblende diorite, from the Bradshaw 

Mountains, Arizona, described by T. A. Jaggar and C, Palache,5

1 Zeitschr. Kryst. Min., vol. 10,1885, p. 444.

2 Min. pet. Mitt., vol. 1,1878, p. 247. .

s Neues Jahrb., 1881, Band 1, p. 32.

* Bull. U. S. Geol. Survey No. 62, 1890, pp. 67-76. Another saussuritized gabbro from the Upper 

Qiiinncsec Falls is described on pp. 102-104. On pp. 58-00 Williams gives a general discussion of this 

form of alteration, with historical details. Seo also A. Cathrein, Zeitschr. Kryst. Min., vol. 7,1883, p. 234.

B Bradshaw Mountains folio (No. 126),- Geol. Atlas U. S., U. S. Geol. Survey, 1905, pp. 4-5.
METAMORPHIC ROCKS. 599

contained 47 per cent of zoisite, derived from plagioclase, 17 per 

cent of actinolite, and smaller amounts of quartz, orthoclase, albite, 

chlorite, kaolin, and magnetite. The following analyses of zoisite 

rocks were made in the laboratory of the United States Geological

Survey:

Analyses of zoisite rocks.

A. Sturgeon Fallsgabbro, freshest form.

B. The same, altered form.

C. Silvery schist derived from Sturgeon Falls gabtoro. Analyses A, B, and C by B. B. Kiggs.

1). Zoisite-hornblende dioritc, Bradshaw Mountains. Analysis by George Stciger.

CJirv

AI263 --------------.------. - --- -- - - 

FeA... ......................................

FpO

MgO..........................................

CaO..........................................

NaaO... .......................................

KO

HgO .........................................

HaO+........... ..............................

Ti02 ................. .........................

CO......... ...................................

Po05 ........... ...............................

A

51.46

14.35

3.90

5.28

9.54

9.08

2.92

.24

| 3.30

.20

100. 27

B

38.05

24.73

5.65

6.08

11.58

1.25

2.54

1.94

} 7.53

.93

100. 28

C

45.70

16.53

4.63

3.89

9.57

4.28

.55

3.82

| 4.70

5.95

99.62

D

45. 73

19.45

5.28

3. 18

6.24

13. 8C

.64

.32

1. 57

3.56

.23

.28

Trace

100. 34.

Tlje sericitization of C is shown by the loss of sodium arid great 

increase of potassium. The Sturgeon Falls series is especially instructive as illustrating the occurrence of several alterations, partly 

simultaneous and partly successive, in the same rock formation. 

Saussurite, sericite, and uralite are all represented.

The transformation of plagioclase into scapolite is by no means 

rare, but the nature of the process is not always easy to trace. Scapolite is often formed by contact reactions between igneous rocks and 

limestones, as well as by processes resembling that of saussuritization. For the latter change, which is the one to be properly considered now, the classical example is furnished by the spotted gabbro 

of Oedegaarden. In this case a plagioclase-pyroxene rock has been 

altered into a scapolite-hornblende mixture, a rock which, according 

to Fouque and Levy,1 is retransformed on fusion into pyroxene and 

labradorite. The alteration, then, is reversible and one which ought 

to be studied quantitatively. The change from plagioclase to scapolite, as investigated by J. W, Judd,2 is probably due to the action of 

sodium chloride, which exists in solution in minute inclusions within

1 Bull. Soc. rain., vol. 2,1879, p. 113.

8 Mineralog. Mag., vol. S, 1889, p. 1S6. See also A. Michel-Le"vy, Bull. Soc. min., vol. 1,1S78, pp. 43,78. A 

similar rock from Bamle, Norway, containing sphcne, amphibole, and wcrncritc, is also described. Other 

noteworthy memoirs oa the Scandinavian rocks o£ this class are by A. E. Torncbohm and E. Svedmark, 

Gcol. Forcn. Forhaudl., vol. 6,1882, p. 192; vol. 7,1884, p. 293.
r

600 DATA OF GEOCHEMISTRY.

the original rock. It must be noted, howevei, that the Oedegaarden 

gabbro is in contact with veins of chlorapatite, from which some of 

the chlorine essential to the formation of scapolite may have been 

derived. , , 

In any case, the conversion of. plagioclase to scapolite requires the 

addition of new material. The scapolites, as shown by G. Tschermak,1 are mixtures of two end species meionite, Ca4Al6Si6025 , and w 

marialite, Na4Al3Si9O24Cl. These may be derived from anorthite and 

albite in accordance with the following empirical equations :

3CaAl2Si308 + CaO = Ca4Al6Si6025.

In order to change an ordinary plagioclase into an ordinary scapo-^ 4. 

lite, then, lime and sodium chloride must be taken up, and it is clear 

that these reagents may come from quite dissimilar sources. The 

change of pyroxene to amphibole may furnish the lime in some cases; 

apatite may yield it, with chlorine, in others; but no general rule, no 

exclusive group of reactions, can be postulated. The widely different 

conditions under which scapolitization may take place have been ^ 

well summarized by A. Lacroix,2 whose two memoirs upon the subject 

are most exhaustive. "

On the epidotization of plagioclase feldspar there is an abundant 

literature.3 Since epidote and zoisite are closely analogous in chemical structure, the process of alteration must resemble that of saus- -~~" 

suritization, from which it differs in detail. Epidote contains iron, 

typical zoisite does not; and that element seems commonly to be 

furnished by hornblende or pyroxene. Feldspar, augite, hornblende, ^ 

and biotite all alter into epidote ; and so, too, in some cases apparently 

does chlorite. The derivation of epidote from chlorite has been 

observed by G. F. Becker 4 in the rocks of the Comstock lode, and * 

although the observation is questioned by some authorities, it is 

not disproved. " Chemically, it is not improbable; but usually the two 

minerals, chlorite and epidote, form simultaneously from a common ^

1 See the section on scapolite in Chapter X, p. 399, ante.

a Bull. Soc. min., vol. 12, 1889, p. 83; vol. 14, 1891, p. 16. Lacroix states that wernerite gneisses are very . 

common. Lacroix and C. Baret (idem, vol. 10, 1887, p. 288) describe a wemerite pyroxenite. Wernerite, ~ 

it will be remembered, is one of the intermediate scapolites. SeealsoH. Wulf, Min. pet. Mitt, vol. 8, 1887, 

p. 213, on a scapolite-augite gneiss from Eerero Land, Africa; and F. Becke, idem, vol. 4, 1882, p. 285, on 

similar rocks from Lower Austria. Scapolite amphibolites are described by 0. Miigge, Neues Jahrb., Beil. 

Band 4, 1886, p. 583, from Masai Land; E. Dathe, Jahrb. K. preuss. geol. Landesanstalt, 1884, p. Ixxvi, from > 

Germany; and F. D. Adams and A. C. Lawson, Canadian Rec. Sci., vol. 3, 1888, p. 185, from Canada. ^ 

Adams and Lawson also describe two scapolite diorites. The scapolite rocks of northern New Jersey 

briefly described by F. L. Nason (Ann. Rept. State Geologist, 1890, p. 33), occur as dikes in crystalline 

limestone, and may have been formed by contact metamorphism. C. H. Smyth (Am. Jour. Sci., 4th ser., 

vol. 1, 1896, p. 273), has described the transformation of a gabbro into a gneiss containing pyroxene, horn- ^ 

blende, feldspar, and scapolite.

3 See A. Cathrein, Zeitschr. Kryst. Min., vol.. 7, 1883, p. 247; A. Schenck, Verhandl. Naturhist. Ver. 

preuss. Rheinlande u. Westfalens, vol. 41, 1884, p. 53; and G, H. .Williams, Bull. U. S. Geol. Survey No. 62, 

1890, p. 56, for summaries of the earlier observations.. .

« Mon. U. S. Geol. Survey, vol. 3, 1882, pp. 75, 76, 213. Criticized by Williams loc. cit., and H. Rosen- "** 

busch, Neues Jahrb., 1884, Band 2, Ref., p. 189.
METAMORPH1C ROCKS. 601

parent. In the rocks of Leadville, W. Cross l found epidote derived 

from orthoclase, plagioclase, biotite, and hornblende. G. H. Williams 2 observed its formation as a contact rim between feldspar and 

hornblende in the gabbro-diorite near Baltimore, and F. D. Chester 3 

described similar occurrences in Delaware. In some of Chester's 

specimens the epidote contained cores of feldspar.

Epidotization, then, represents a reaction between the feldspars 

and the ferromagnesian minerals of a rock, and when it is complete 

a mixture of quartz and epidote remains. Such a rock is known as 

epidosite, and its formation has been many times recorded. J. Lemberg 4 describes an alteration of this kind from augite porphyry; 

and Schenck 5 reports the derivation of epidosite from diabase. 

Unakite is a remarkable rock consisting of rose-colored orthoclase 

and green epidote, first described by F. H. Bradley 6 from western 

North Carolina. It has since been found near Milams Gap, Virginia. 

According to W. C. Phalen,7 who has studied this locality, the unakite is derived from a hypersthene akerite, or quartz-diallage syenite, 

and it contains, in addition to the two principal minerals, some 

quartz, iron oxides, zircon, and apatite. It passes into epidosite by 

further alteration. Epidote-quartz rocks from New Jersey have also 

been briefly described by L. G. Westgate.8 Here, as at Milams Gap, 

the epidote is thought to be derived from pyroxene.

Garnet is a common mineral of the metamorphic rocks, and is often 

indicated in their nomenclature. Garnet gneiss, garnet-mica schist, 

garnet hornfels, and garnet-olivine rock are good examples. In 

these rocks, however, garnet is commonly an accessory mineral rather 

than a main constituent. On the other hand, rocks are known consisting chiefly or largely of garnet, and one of these, eclogite, has 

been the subject of many investigations.9

Eclogite is essentially a rock composed of red garnet, with a green 

pyroxene, omphacite. It may also contain, subordinately, hornblende, quartz, zoisite, kyanite, and muscovite, with zircon, apatite, 

sphene, epidote, magnetite, pyrite, and pyrrhotite as minor accessories. 10 According to J. A. Ippen,11 the Styrian eclogites shade into 

omphacite rock on one side and into garnet rock on the other; that 

is, either mineral may predominate and give its own character to

I Mon. U. S. Geol. Survey, vol. 12,188C, pp. 341, 357.

a Bull. U. S. Geol. Survey No. 28,1886, p. 31.

« Bull. U. S. Geol. Survey No. 59,1890, p. 35.

4 Zeitschr. Deutsch. geol. Gesell., vol. 29,1877, p. 498.

»Verhandl. Naturhist. Ver. preuss. Rheinlande u. Westfalens, vol. 41,1884, p. 53.

o Am. Jour. Sci., 3d ser., vol. 7,1874, p. 519.

' Misc. Coll. Smithsonian lust., Quart. Issue, vol. 1,1904, p. 301.

e Ann. Rept. State Geologist New Jersey, 1895, p. 30.

9 See Zirkel's Lehrbuch der Petrographie, 2d ed., vol. 3, p. 369, for many references. The papers by Lohmann and Hezner, cited on the next page, also contain bibliographies.

1° See R. von Drasche, Jahrb. K.-k. geol. Reichsanstalt, 1871, Min. Mitt., p. 85, and E. R. Ricss, Min. pet. 

Mitt., vol. 1,1878, pp. 165,181.

II Mitt. Naturwiss. Ver. Steiermart, 1892, p. 328.
602 DATA OF GEOCHEMISTRY.

the mixture. The eclogites of the lower Loire, according to A. 

Lacroix,1 sometimes contain feldspar formed as a secondary mineral 

during the uralitization of highly aluminous pyroxenes. Lacroix 

shows that these rocks are products of dynamometamorphism. The 

crushing and fracturing of the original rocks has facilitated the circulation of the waters to which their alterations are due.

L. Hezner,2 who studied eclogite from the Oetzthal, in the Tyrolese 

Alps, regards it as a metamorphic derivative of gabbroid rocks. By 

further metamorphosis it passes into amphibolite, the eclogite being 

the deeper-seated phase. The garnet, he thinks, was formed by a 

reaction between plagioclase and olivine, or perhaps between plagioclase and pyroxene. The omphacite alters into hornblende, and so, 

too, does the garnet, but later. First eclogite, then garnet amphibolite, then amphibolite, is the order of these allied rocks. Plagioclase 

also appears, as observed by Lacroix, among the products of alteration, together with epidote, chlorite, magnetite, zoisite, and biotite.

The following analyses of epidote and garnet rocks are from the 

memoirs already cited:

Analyses of epidote and garnet rocks.

A, B. Epidosite derived from diabase, upper Ruhrthal, Germany. Analyzed and described by Schcnck.

C. Unakite, Milams Gap, Virginia. Analysis by Phalen.

D. Eclogite, Sulzthal, Styrin.

E. Eclogite, Burgstein, Styria. Analyses D and E by Hezner.

SiOo... ..............................

AlaOs. ...............................

Fe203 ........... .....................

Feb

MgO. ................................

CaO.................................

Na2 0................................

K20. ...... ............ ...............

H20-. .......... .....................

H20+-- ................... ...........

Ti02 .. ...............................

Zr02 .... .............................

P 0

M*d.. ...............................

FpS

A

42.13

19.21

11.19

2.52

.41

21.42

.29

.08

} 2.39

1.40

.08

.25

101. 37

B

50.26

13.72

9.18

2.97

2.20

16.30

.71

1.12

} 1.88

1.60

.39

Oft

100. 59

c

58.32

15.77

6.56

.89

.09

11.68

.32

4.01

} 1.73

(a)

Trace.

.48

.13

99.98

D

44.06

17.63

3.40

9.96

7.19

11.58

2.92

.91

.12

.17

2.29

100. 23

E

46.26

14.45

4.41

5.82

U QQ

11.66

9 4-^

1.51

1.10

.28

99.93

a Not separated from alumina. 

CHLORITIZATION.

In chloritization we find a stage of metamorphism which is nearly 

akin to decomposition. Any ferromagnesian mineral may alter into 

chloritic material, and that, by further change, may break down into

1 Bull. Soc. sci. nat. do 1'Quest de la France, vol. 1,1891, p. 81.

* Min. pet. Mitt., vol. 22,1903, pp. 437, 505. See also E. Joukovvsky, Compt. Rend., vol. 133,1001, p. 1312, 

on alterations of eclogite from Lac Cornu. Other valuable papers upon eclogite are by P. Lohmann, Neues 

Jahrb., 1884, Band 1, p. 83; and F. Becke, Min. pet. Mitt., vol.4,1882, pp. 317-322. Eclogites from California 

have been described by R. S. Holway, Jour. Geology, vol. 12, 1904, p. 344, and J. P. Smith, Proc. Am. 

Philos. Soc., vol. 45, 1906, p. 183.
METAMORPHIC -BOCKS. 603

-^ a mixture of carbonates, limonite, and quartz. The gabbros of Michigan, described by G. H. Williams,1 show clearly the successive steps 

of uralitization and chloritization, the final product often being a 

^ ehloritic schist. Diabase and diorite are often chloritized, gaining 

thereby the green color to which the common appellation "greenstone" is due. In diabase the ehloritic substance is commonly 

. derived from augite, calcite and quartz being formed at the same time. 

The alumina needed to produce' the chlorite is probably furnished by 

feldspar.2 Under anhydrous conditions, as we have already seen, 

_^ a reaction between feldspars and ferromagnesian minerals yields 

garnet; possibly the formation of chlorite is similar, but effected in 

presence of water. The alterability. of garnet into chlorite empha-

^ sizes this suggestion.

The chlorites developed in rocks of igneous origin are rarely definite 

species. They are, as a rule, variable mixtures, of which many have 

received specific names. Diabantite and prochlorite, both ferriferous, are perhaps the most common. Because of this vagueness, 

Rosenbusch prefers to use the collective term "ehloritic substance"

^ hi describing the products of this class. The general names "viridite" and "chloropite" have also been proposed; the one by H.

* Vogelsang, the other by C. W. Gumbel.

CONSTITUTIONAL FORMUL^.

* Although it is not yet possible to write positive reactions for all 

of the alterations that we have so far been considering, some of them 

are partly elucidated by the structural formulae of several minerals. 

A A number of these species are curiously alike in constitution, and with 

them other minerals, not specifically studied in this chapter, may 

also be compared. Taking the tripled formulae of orthoclase and

*y albite, which are suggested by the alteration of albite into marialite, 

the following system of formula) can be developed: 3

Orthoclase....................................... Al3(Si308)3K3 .

-* Albite..........................................Al3 (Si308)3Na3 .

Marialite........................................Al2 (Si308)3Na4 (AlCl).

Nephelite......................................Al3(Si04)3Na3 .

Paragoriite...............'.....,................ .Al3(Si04)3NaH2 .

"""' Muscovite......................................Al3 (Si04)3KH2 .

Topaz..........................................Al3(Si04)3 (AlF2)3 .

""' Andalusite....................................... Al3(Si04)3(A10) 3 .

"% Biotite............................................. Al2(Si04)3Mg2KH.

Garnet............ '. .............................Al2 (Si04 )3Ca3 .

Prelmite........................................Al2(Si04 )3Ca2H2 .

Zoisite......................................... Al2 (Si04 )3Ca2 (A10H). ^,j .__________________________________________ ____ .,

i Bull. U. S. Gcol. Survey No. 62,1890.

 » Seo O. W. Hawes, Am. Jour. Sci., 3d ser., vol. 9,1875, pp. 190, 454. Also A. Schenck, Verhandl. Natur. 

hist. Ver. preuss. Rheinlande u. Wostfalens, vol. 41,1884, p. 74. Chloritization is fully discussed by lloscnbusch in his Mikroskopischo Physiographie der massigon Gesteinc, 2d ed., vol. 2, pp. 180-184. 

""*' s See F. W. Clarke, Bull. U. S. Geol. Survey No. 588,1914, for an extended discussion of these formate.
604 DATA OF GEOCHEMISTRY.

Epidote resembles zoisite, but with iron partly replacing aluminum, 

and "similar replacements occur in the garnet group.

These formulae, however, are neither absolute nor final. They 

represent definite relations, and also the minimum molecular weights 

assignable to the several minerals, the true molecular weights being 

unknown and at present undeterminable. It is probable that some 

of the formulae should be doubled, and when that is done some striking new relations appear. This is shown in the following group of 

structural expressions:

v SiO4E=Al2 =SiO4,

Al SiO4=Al2 EESi04 Al ' Al Si04=Ca3=Si04 Al

Anorthite.

,Si04=Ca3=Si04v

Al Si04=Ca3EESi04 Al

N3i04==Ca3=Si04/

In melilite. 1

,Si04=Al2=Si04v

Al Si04=Ca3=Si04 Al

\Si04 Ca SiO/

Ca Ca

Lime earcolite.

v

Al Si04=ECa3=Si04 Al 

\Si04 SiO/

(AlO2Ca) 3 (A102Ca)3 

In gehlenite. 1

x 434, 

Al Si04E=Ca3=Si04 Al 

, Ca SiO/

A10H A1OH

Vesuvianite.

Garnet.

x

Al Si04=Ca3=Si04 Al 

iO, Ca SiO/

S2 H2

Prehnite.

xSi 424v 

Al Si04=Ca3=Si04 Al 

i04 Ca SiO/

Na Na

Soda sarcolite.

,Si04=Al2 =ESiO4v

Al-Si04=Ca3=Si04 Al

\Si04 Ca SiO/

AlOH AlOH

Zoisite.

. ,Si04==Al2 ==Si04v 

Al SiO4=Al2 =Si04 Al 

S\Si04=Ca2=Si04//

Ca 0 Ca

Meionite.

In the first gro^ip of formulae the fundamental nucleus, which occurs in all of them,2 is Al(SiO4 ) 3 . In the second group it is Al2 (Si04 )6,

1 These formulae represent the characteristic compounds in the mixed crystals, melilite and gehlenite. 

3 Except the trisilicate feldspars in -which the group SiaOe is equivalent to SiO<.
 METAMORPHIC ROCKS. ; . 605

or double the other... The two sets are identical in type/ and with their 

aid the observed alterations become intelligible. One species changes 

into another by replacements of atoms, the typical structures the 

nuclei, so to speak remaining undisturbed. When the trisilicate 

feldspars alter into orthosilicates, silica is liberated; but the other 

changes are simpler. For example, nephelite, topaz, and andalusite 

all change easily into muscovite; members of the garnet group can 

form epidote, biotite, or the normal chlorites, and so on. Pyroxenes 

and amphiboles, however, are compounds of different structure from 

those given in the foregoing table, and the mechanism of their alterations is not so clear. Some of the phenomena are easily.understood; 

others still await interpretation. It is possible to write empirical 

equations in all cases, but;they have slender value. A. correlation 

between molecular constitution and the'observed changes must be 

established before the chemistry of metamorphism can be completely 

outlined. The formulae given here represent the atoms as if they 

were arranged on a plane surface, in accordance with the laws of valency. The ultimate formulae, which will doubtless be developed at 

some future time, will assume the form of a tridimensional model. 

The relations now shown will then be shown more perfectly.

TALC AND SERPENTINE.

When distinctively magnesian silicates undergo hydrous metamorphism, which happens chiefly in the belt of weathering, the 

product is likely to be either talc or serpentine.1 Other hydrous silicates may be formed also, together with carbonates and the hydroxide, brucite; but the two species just named are the most important. 

I speak now, of course, with reference to alterations in place; such 

a rock as dolomite falls in quite another category.

A typical production of serpentine is from rocks containing olivine; 

and the probable reaction is as follows:

2Mg2Si04 + 2H2 0 + C02 = Mg3H4Si2 09 + MgCO.. 

Olivine. Serpentine. Magnesite.

Peridotites are especially liable to this sort of alteration, and 

many serpentine rocks can ,be assigned this origin.2 The well-known 

Lizard serpentine of Cornwall, for instance, has been shown by 

T. G. Bonney 3 to be an altered Iherzolite.

i According to 0. P. Merrill (Geol. Mag., 1899, p. 354) the formation of serpentine as a rock is a deep-seated 

process. This conception, however, does not preclude the generation of disseminated serpentine', regarded 

not as a rock but as a mineral species, within the belt of weathering. See also T. H. Holland, Geol. Mag., 

3899, p. 540.

« See F. Sandberger, Neues Jahrb., 1866', p. 385; idem, 1867, p. 176; G. Tschermak, Sitzungsb. K. Akad. 

Wiss. Wien, vol. 56,1867, p. 261; E. Weinschenk, Abhandl. K. bayer. Akad., Math.-phys. Klasse, vol. 18,, 

p. 651; J. Lemberg, Zeitschr. Deutsch. geol. Gesell., vol. 27, 1875, p. 531; B. Weigand, Jahrb. -K.-k. geol. 

Reichsanstalt, 1875, Min. Mitt., p. 183. F. Zirkel (Lehrbuch der Petrographie, 2d ed., vol. 3, p. 404) 

gives an extensive bibliography of serpentine.

8 Quart. Jour. Geol. Soc., vol. 33,1877, p. 884.
606 DATA OF GEOCHEMISTRY.

Pyroxenes, also, are- often converted into serpentine. The equation, in the case of diopside, is perhaps "as. follows:

3MgCaSi306 + 3C02 + 2H2 0 = Mg3H4Si2 09 + 3CaC03 + 4SiO,.

Diopside. Serpentine. Caleite. Quartz. jr

This reaction is sustained by the fact that serpentine rocks often 

contain quartz and calcite. When serpentine is formed from gabbro ^. 

or pyroxenite the change i& probably of this kind, although it may 

have been preceded by uralitization of the pyroxene. Serpentines 

derived from amphibolites have been repeatedly described.1 ^

In short, serpentine may be formed from -any silicate which happens to be rich in magnesia, such as olivine, pyroxene, amphibolc, 

garnet, 2 or chondrodite.3 It also appears to be produced by the +* 

action of percolating magnesian waters upon nonmagnesian minerals, 

such as feldspars, and possibly, even, quartz.4 J. Lemberg 5 has 

shown that solutions of magnesium carbonate will attack oligoclase, ^ 

replacing sodium by magnesium to a considerable extent; but alterations of this sort are not very common. Many reported changes of 

minerals to talc or serpentine have been erroneous, for compact mus- -*« 

covite is easily mistaken for them. A pseudomorphous mineral 

should be called serpentine or steatite only after thorough chemical 

and optical examination. The mere fact that a mineral is green, 

soft,, compact, and soapy to the touch is not enough to establish its 

character, '"*""'

In many localities serpentine is associated with dolomite or dolomitic limestone. In these cases, the mineral has been derived; from 

magnesian silicates, which were first formed within the limestone by 

metamorphic processes. In the limestones of Westehester County, 

New York, according to J. D. D'ana,6 the parent minerals were tremolite or actinolite. It is possible also that some dolomite itself may *<" 

have become silicated, yielding serpentine by alteration of the compounds thus formed. Similar views are advanced by S. F. Emmons 7 

with reference to serpentines found near Leadville, Colorado. The 

serpentine of Montville, New Jersey, which is also in dolomite, was 

shown by G. P. Merrill 8 to be derived from pyroxene, and the same 

conclusion was reached regarding the ophiolitc or ophicalcite of ^

1 B. K. Emerson (Mon. U. S. Geol. Survey, vol. 29,1898, p. 114) assigns tin's origin to the serpentine o£ ^ 

the Connecticut Valley. An Australian amphibolite serpentine has also been described by J. B. Jaquot, ^^ 

Bee, Geol. Survey New South Wales, vol. 5,1806-1898-, p. 21. ^P

2 See A. Schrauf, Zeitschr. Kryst. Min., vol. 6,1882, p. 321.

s See J. D. Dana, Anl. Jour, SeL, 3d ser.,, voL 8,I8T4, p. 371, on serpentine pseudomorphs from the- Tilly 

Foster mine.

4 See G. F. Becker, Mon. U. S. Geol. Survey, vol. 13,1888, pp. 108-128. , 

5< Zeitschr. Deutsch. geol. GeseD., vol. 22,1870, p. 345; vol. 24,1872, p, 255.. ^* 

° Am. Jour. SeL, 3d ser., vol. 20> 1880, p. 30.. 

i' Mon. U. S. Geol. Survey, vol. 12,1886, p. 282. 

8 Troc, U. S. Nat. Mus., vol. llr 1888,.p. 105.

* 
METAMOKPHIC ROCKS. 607

Warren County, New York. 1 The " verde-antique" marbles are 

familiar illustrations of this commingling of carbonates with serpentine. A quite different blending of serpentine with other minerals is 

that described by me from Stephens County, Washington.2 This mixture was apparently a normal serpentine; but upon analysis it was 

found to contain only 20 per cent of that species, with 60 per cent of 

brucite, 14 per cent of chlorite, and 5 per cent of hydromagnesite. 

Its origin, so far as I am aware, has not been determined.

In the quicksilver region of California G. F. Becker 3 found serpentines which had been decomposed by solfataric agencies until 

only the silica remained. Similar reductions of serpentine to opal, 

chalcedony, and quartz have been recorded by A. Lacroix. 4 The 

acids of volcanic fumaroles had removed the bases of the serpentine 

in the form of soluble sulphates.

From what has been said so far it is evident that serpentine originates in various different ways. Some* serpentine is merely altered 

peridotite, pyroxenite, or gabbro; and some of it is derived from 

dolomite or other sedimentary rocks. Indeed, the sedimentary origin 

of serpentine has had many strong advocates, the chief among them 

having been the late T. Sterry Hunt.5 L. Dieulaf ait 6 also has argued 

that the serpentines of Corsica are true sedimentary rocks. There is, 

in fact, no valid reason why siliceous magnesian sediments, precipitated or detrital, should not form beds of serpentine; but the rock is 

commonly a metamorphosed eruptive, or else the result of a secondary metamorphism of siliceous limestones. In both of these generally recognized modes of formation the chemical processes are the 

same. The same magnesian silicates are altered in the same way 

irrespective of their igneous, metamorphic, or sedimentary origin. 

In some cases magmatic waters may be the chief agent in effecting 

serpentkuzation. The serpentines of New South Wales, for example, are regarded by W. N. Benson 7 as due to the alteration of an 

intrusive peridotite by waters contained in the same magna.

Serpentine is a basic orthosilicate, talc an acid metasilicate. The 

former alters easily, and is readily decomposed; the latter is one of 

the least alterable and therefore among the most stable, under 

aqueous conditions, of mineral species. Both minerals are decomposed by heat, but differently. Serpentine breaks up into enstatite 

and olivine; talc into enstatite or anthophyllite and cjuartz, water

' Am. Jour. ScL, 3d ser.. vol. 20,1880, p. 30.

2 Bull. U. S. Geol. Survey No. 262,1905, p. G9.

s Mon. U. S. Geol. Survey, vol. 13,1888, p. 127.

i Compt. Rend., vol. 124,1887, p. 513.

G Mineral physiology and physiography, 188G, pp. 434-516. Hunt cites a largo amount of evidence from 

Italian sources.

o Compt. Rend., vol. 91,1880, p. 1000.

7 Am. Jour. Sci., 4th ser., vol. 4fi, 1918, p. 683. Beuson gives a long list of references to tlio literature cJ 

serpentine.
608 DATA OF GEOCHEMISTRY.

being eliminated in both cases. These decompositions may be 

written thus: 

Mg3H4Si2 09 = Mg2Si04 + MgSiO8 + 2H2 0. 

Mg3H,Si4012 = 3MgSi03 + Si02 + H20.

Talc, like serpentine, may originate in different ways; but.its commonest derivation seems to be by the alteration of amphiboles or 

pyroxenes. C. H. Smyth, 1 who studied the talc of St. Lawrence 

County, New York, found it to be derived in that region from enstatite 

and tremolite, according to. the following reactions:

4MgSiO3 + H2O + CO2 = Mg3H2Si4O12 + MgCO3 . 

Mg3CaSi4012 + H2 0 + G02 - Mg3H2Si4012 + CaC03 .

These reactions are much alike, and resemble those which are recog- . 

nized in the formation of serpentine. In fact, many serpentines 

contain admixtures of talc, and when the original rocks are at all 

aluminous, chlorites also may appear. Soapstone or steatite is 

impure, massive talc.

According to Smyth, the St. Lawrence County talc is found associated with crystalline limestones. J. H. Pratt 2 found the deposits 

of North Carolina to be in connection with marble, and capped by 

quartzite. In the same region pyrophyllite occurs, a hydrous silicate of aluminum, HAlSi206, which much resembles talc and may 

be mistaken for it. The talc itself appeared to be derived from 

tremolite. Smyth assumes that a siliceous limestone was first laid 

down, which became, by metamorphism, a tremolite-enstatite schist. 

The latter, by hydration, became talc. This, however, is not the 

only way in which steatite has been formed. A. Gurlt 3 reports its 

formation from dolomite along contacts with amphibolite; and C. H. 

Hitchcock 4 regards the steatites of New Hampshire as alterations 

of what was originally igneous matter. The talc of Mautern in 

Styria is traced by K. A. Redlich and F. Cornu 5 to the action of 

magnesian solutions upon the surrounding schists. Pseudomorphs 

of talc after many minerals have been described, but not all of the 

reports are authentic. The warning given under serpentine may well 

be recalled here. Pseudomorphs of talc after quartz, however, seem 

to be well known. 6 Much work needs to be done in order to determine the origin of soapstone generally.

1 School of Mines Quart., vol. 17,18%, p. 333. A paper by A. A. Julien on the origin of talc and sc.rpentine is in Annals New York Acad. Sci., vol. 24,1914, p. 23. 

' North Carolina Geol. Survey, Econ. Paper No. 3,1900. 

3 Sitzungsb. Niederrhein. Gesell. Natur u.-Heilkunde, Bonn, 1865, p. 126.

4 Jour. Geology, vol. 4,1896, p. 58.

6 Zeitschr. prakt. Geologic, 1908, p. 145.

e E. Weinschenkj Zeitschr. Kryst. Min., vol. 14,1888, p. 305.
METAMORPHIC ROCKS. 609

The following analyses represent talcose and serpentinous rocks 

of varied characters.

Analyses of talcose and serpentinous rocks.

A. Dark-green serpentine, Eowe, Massachusetts. Described by B. K. Emerspn-in Mon. U. S. Geol. 

Survey, vol. 29,1898. Analysis by G. Steiger.

B. Serpentine, Greenville, California. Described by J. S. Dillerin Bull. U. S. Geol. Survey No. 150,189S, 

p. 372. Derived mainly from pyroxene. Analysis by W. H. Melville.

C. Serpentine, Sulphur Bank, California. Described by G. F. Becker in Mon. U. S. Geol. Survey, vol. 

13,1888. Analysis by Melville.

D. Serpentine derived from pyroxenite, Mount Diablo, California. Analyzed and described by Melville, 

Bull. Geol. Soc. America, vol. 2,1890, p. 403.

E. Serpentinous rock of unusual composition; also from Mount Diablo. Analyzed and described by 

Melville, loc. cit.

F. "Ovenstone" from Canton Valais, Switzerland. Described by T. G. Bonncy (Geol. Mag., 1897, p. 

llO)asastageinthealterationof serpentine. - The original rock was perhaps a basalt or dolerite. Analysis 

by Emily Aston.

G. Brucite serpentine, Stevehs County, Washington. Described by F. W. Clarke, Bull. U. S. Geol. 

Survey No. 262,1905, p. 69. Analysis by G. Steiger.

H. Steatite, Griqualand West, South Africa. Described by E. Cohen, Neues Jahrb., 18S7, Band 1, p. 

119. Analysis by Van Eiesen.

Si02 .................

Al,0,.... ............

iVO

FeO

MgO......... ........

CaO. ................

Na,,0. -- --- -- - K9 6....... ........... H;O-. ........:....

HaO+... ...........

TiO

00 " " 

P 6

Oo03 - - ----- 

NiO.. ...............

CoO.................

MnO.................

SO..................

FcS2 ... ..............

A

40.42

1.86

2.75

4.27

35.95

.66 }.-"

.21

10.51

None.

1.44

Trace.

. .28

.53

Trace.

Trace.

.43

99.47

E

39.14

2.08

4.27

2.04

39.84

Trace.

}l2. 70

'

.11

100. 18

C

41.86

.09

4.15

38.63

}l4. 16

.24

Trace.

.20

99.93

D

40.50

.78

4.01

2.04

37.43

.39

.28

.16

2.81

10.94

Trace.

.41

.11

.13

99.99

E

30. 98

1.04

4.01

2.01

38.44

.22

.40

.16

.39

20.43

Trace.

.34

.42

.44

100. 15

F

44.94

5.47

4.88

3.47

25.57

8.76

OK

5.40

1 99

Trace.

9 on

n^i»Q(-»Q

99.83

G

13.08

1.63

1.75

.19

56.44

.33

None.

.85

23.94

2.03

99.74

 ' H

63.29

1.24

1.25

4.68

27.13

Trarp

} 4.40

100. 00

The presence of chromium and nickel in several of these rocks is a 

good indication of a relationship with the pyroxenite. and peridotites. Chromite and nickel ores are very generally associated with 

these magnesian eruptives.

QTJARTZITE.

The processes which operate in the metamorphism of sedimentary 

rocks are partly identical with those which we have just been considering. This fact has already been indicated in several connections. 

A shale, or sandstone, contains fragments of minerals, usually more or 

113750° 19 Bull. 695 39
610 DATA OF GEOCHEMISTRY.

less weathered, and these undergo the normal changes. " Feldspar 

becomes sericite, hornblende alters to chlorite, and so on, exactly as 

in the metamorphoses of igneous material. The substances affected 

are the same, and so are the reactions. The formation of serpentine 

from pyroxene, for example, is, as I have already said, the same 

process, whether it is effected upon the pyroxene of a gabbro or upon 

the pyroxene developed by contact metamorphism in a crystalline 

limestone.

There is, however, another set of changes which are peculiar to the 

sedimentaries. These rocks contain decomposition products, such as 

kaolinite, hydroxides of aluminum and iron, etc., which give rise to a 

different group of reactions, and these generate another class of mineral species. Kyanite, andalusite, sillimanite, staurolite, and dumortierite are among the minerals thus developed in schists which once, 

were shales. These minerals, again, can alter into mica, so that a 

mica schist may represent the outcome of a seriefe of transformations, 

the intermediate products having disappeared.

Just as the sedimentary rocks shade into one another, so, too, do 

their metamorphic derivatives, but with even greater complexity. 

For the metamorphosed rocks contain not only the original minerals 

of the sediments, but also the new products formed by alteration. 

Perhaps the simplest of these changes is that of a sandstone into a 

quartzite, which, in the first instance, is brought about by infiltration 

of silica. In this way the interstices of the sandstone are filled up 

and a porous rock is transformed into a compact one. But as sandstones are not all sand, so quartzites are not all silica., A micaceous 

sandstone yields a micaceous quartzite; a f eldspathic sandstone may 

form either an arkose gneiss, or by sericitization it can become a mica 

schist; and between these different rocks there are all manner of 

gradations. These changes, moreover, are often complicated by 

structural modifications due to dynamic agencies; so that from similar sandstones very different rocks can be derived. In some,cases 

the nature and order of the changes can be traced; in others they 

seem to be hopelessly obscure.1

The following analyses of quartzite and quartz schist are useful for 

comparison with the analyses of sandstones given in the preceding 

chapter: '

i For a full discussion relative to the formation.of quartzite, sen C. R. Van Hise, A treatise on metamorphism: Mon. U. S. Geol. Survey, vol. 47,1904, pp. 865-880. See also K. D. Irving, Bull. U. S. Geol. Survey 

No. 8,1884, p. 48; Am. Jour. Sci., 3d ser., vol. 25,1883, p. 401. Important papers on the subject have been 

written by C. Lossen, Zeitschr. Deutsch. geol. Gesell., vol. 19,1867, p. 615, and W. J. Sollas, Sci. Proc. Roy. 

Dublin Soc., vol. 7,1892, p. 169.
METAMORPHIC BOCKS. 611

 Analyses of quartzite and quartz schist.

A. Dark vitreous quartzite, Pigeon Point,'Minnesota. Contains quartz, with a little feldspar, chloritc, 

mica, and magnetite. Described by W. S. Bayley, Bull. U. S. Gcol. Survey No. 109,1893. Analysis by 

R.B. Riggs.

B. Red vitreous quartzite, Pigeon Point. Bayley and Riggs as above.

C. Quartzite, South Mountain, Pennsylvania. Described by F. Bascom, Bull. U. S. Gcol. Survey No. 

136,1896. Analysis by F. A. Genth, on p. 34.

D. Quartz schist, near Stevenson station, Maryland. Contains quartz, muscovitc, tourmaline, microcline, zircon, and iron stains. Described by Bayley, Bull. U. S. Gcol. Survey No. 150,1898, p. 302. Analysis by E. A. Schneider.

SiOa ...... ..........!..... .....................

Al.,0,---- Fp"0 ----- ------ ----- ----- --- --- -

FeO. ..........................................

MgO........ ..................................

CaO..........................................

Na,0.........................................

K20... ........................................

H20. ..........................................

Ti08 .... ......................................

P f>

MnO..........................................

A

74.22

10.61

7.45

.85

1.48

.56

2.12

1.08

M. 79

.16

None.

100. 32

B

83.69

7.50

1.81

.38

.35

.39

2.46

2.61

.72

Trace?

Trace.

99.91

c

a 92. 00

4.21

1.80

.04

.16

1.16

&.96

.14

.21

100. 68

D

91. 65

1.59

3.57

.21

.17

None.

.07

1.93

.60

.13

None

Trace.

99.92

84.13 per cent quartz, 7.87 per cent combined silica. b Loss on ignition.

METAMORPHOSED SHALES.

i

Shales, slates, phyllites, and mica schists form a continuous series 

of rocks which can be derived from clay, mud, or silt by progressive 

dehydration and crystallization.. Some mica schists, of course, are 

traceable back to igneous rocks, but they fall outside of the present 

category. 'In order to study the development of schists from shales 

or clays, we must consider what" compounds the latter contain capable of dehydration and what are produced in this class of metamorphoses.

This ground has already been partly covered in the two preceding 

chapters. The final products of rock decomposition, apart from 

those that are removed in solution, are hydroxides of iron and 

aluminum; free silica, anhydrous or opaline; and hydrous silicates 

of iron, aluminum, and magnesium. The simple hydroxides offer 

the least difficulties in the way of interpretation. The iron compounds yield hematite, which is a common mineral in the metarnorphic schists, and which, in presence of organic matter, may be 

reduced to magnetite.1 The aluminum hydroxides may furnish diaspore if the dehydration is, partial, or corundum when the reaction 

is complete. Opaline silica loses water and becomes converted

' Tf a bed of limonite be regarded as a sedimentary rock, a bed of hematite may be its metamorpliic 

equivalent.
612 DATA OF GEOCHEMISTRY.

into quartz. These changes are of the simplest character, but it is 

not .certain that they always take place. It is possible that the 

colloidal silica may react upon the colloidal hydroxides, and form 

silicates anew; but I am not sure that this class of reactions has been 

proved. They are conceivable, and therefore can not be left out of 

account. The known changes, as I have stated them, are those of 

the compounds themselves when not commingled with other substances. Hematite, magnetite, corundum, and quartz can be formed 

in the manner indicated; and hematite or magnetite schists (schists 

containing these minerals in conspicuous proportions) are not rare. 

The itabirite of Brazil is a rock of this kind, containing hematite, 

magnetite, and quartz.1 Similar rocks have been described by H. 

Coquand 2 in France, and 0. M. Lieber 3 in South Carolina. Coquand's rock is described as equivalent to a mica schist containing 

specular hematite in place of mica. Itabirite from Okande Land, 

West Africa, is reported by 0. Lenz 4 as containing quartz, hematite, 

and magnetite, with quartz predominating. Another example from 

the Gold Coast, described by C. W. Gumbel,5 contains also muscovite, 

ilmenite, and free gold. A German schist examined by C. Lessen' 

consisted of specular hematite and quartz.

FERRUGINOUS SCHISTS.

The ferruginous schists of the Lake Superior region may properly 

be mentioned here. According to C. R. Van Hisej7 they are derived 

from carbonate rocks which he calls sideritic slates. These, by oxidation, pass into limonitic or hematitic slates, and from the latter the 

schists are derived. Ferruginous cherts are also formed, and some 

banded rocks of chert and hematite which Van Hise calls jaspilite. 

The silicification of the original siderite is attributed to the action of 

silica contained in percolating waters. The following analyses of the 

schists were made in the laboratory of the United States Geological 

Survey:

1 See Zirkel, Lehrbuch der Petrographie, 2d ed., p. 570, forreferences. >

»Bull. Soc. g6ol. France, 2d ser., vol. 6,1849, p. 291.

> Kept. Survey South Carolina, 1855, pp. 89^94; 1857, p. 79; 1858, p. 107. . 

< Verhandl. K.-k. geol. Reichsanstalt, 1878, p. 168. .

» Sitzungsb. K. Akad. Wiss. Miinchen, 1882, p. 183.

 Zeitschr. Deutsch. geol. Gesell., vol. 19,1867, p. 614. Zirkel refers also to Norwegian examples reported 

by J. H. L. Vogt in a memoir which I have not seen.

' A treatise on metamorphism: Mon. U. S. Geol. Survey, vol. 47,1904, pp. 830-842. See also the literature 

therecited, and especially Mon. U. S. Geol. Survey, vol. 28,1895, by C. R. Van Hise and W. S. Bayley. 

On the metamorphism of oil shales by the combustion of their hydrocarbons, see R. Arnold and R. Anderson, Jour. Geology, vol. 15,1907, p. 750.
METAMORPHIC ROGKS.

Analyses of ferruginous schists.

613

A. Griinerite-magnetite schist, Marquette region, Michigan. Contains grunerite, magnetite, and 

quartz. Described by C. R. Van Hise and W. S. Bayley in Mon. U. S. Geol. Survey, vol. 28, 1895. 

Analysis by H. N. Stokes.

B. Actinolite-magnetiteschist, Mesabi Range, Minnesota. Described by W. S. Bayley, Am. Jour. Sci., 

3d ser., vol. 46,1893, p. 178. Consists of actinolite and magnetite. Analysis by W. H. Melville.

SiO-v.............................................. '.........-..

A1203 . .........................................................

Fea08 .. .........................................................

FpO

MgO.. .........................................................

CaO ...........................................................

Na,0. . ........ 1 .:..................'........................... H26-. .....:.........................................:........

Ti02 ..... ......................................................

PA...........................................................

MpO........ ...................................................

CuO. .-. .........................................................

A

46.25

.92

' 30. 62

16.92

2.13

1.69

None.

.42

MAHD

.07

1.01

TVflpp

100. 03

v

12.35

.10

58.68

21.34

4.08

1.91

Trace.

19

12

.25

1.22

100. 24

DEHYDRATION OF CLAYS.

Rocks like those just considered, obviously, may vary from nearly 

pure amphibole to nearly pure iron ore, and the quartz-hematite 

schists may range between the two extremes in the same way. In all 

cases, however, the final product represents the dehydration of hydroxides, followed by partial reduction in the case of the magnetite 

schists. The origin of the hydroxides, whether from carbonates or 

from silicates, is a separate* question.

The hydrous silicates of the sediments are chiefly those of aluminum. Some iron compounds also occur, such as glauconite, chloropal, 

or nontronite, but their mode of decomposition when hydrated is 

not clearly known. In many cases, probably, they break down into 

ferric oxide and quartz; but they also, doubtless, contribute to the 

formation of less hydrous minerals, like staurolite and chloritoid. 

Of these species, more later. Magnesian silicates must also exist in 

the sediments, as talcose or serpentinous matter, but their dehydration products have already been discussed.1

Many hydrous silicates of aluminum have been described. A few 

of them are definite, others are more or less doubtful. Some, probably, are colloidal mixtures, which should not be formulated as distinct 

chemical compounds. The following minerals in this class are recognized by Dana as true, species:

' Seep. 586,ante.
614 DATA OF GEOGHEMISTKY.

Kaolinite .'........... . ......................... .H4Al2Si209 .

Halloysite.....................................H4Al2Si209+aq.

Newtonite...'.................................. .H8Al2Si2Ou+aq.

Cimolite.............................................H6Al4Si9027 +3aq.(?)

Montmorillqnite................................H2Al2Si4012+^ aq.

Pyrophyllite....................................H2Al2Si4012 .

Allophane.....................................Al2Si05 .5aq.

Collyrite........................................Al4Si08 .9aq.

Schrotterite.................................... Al16Si3030 .30aq.

To this list rectorite 1 and leverrierite 2 should probably be added. 

Leverrierite, as described by P. Termier, has the composition of muscovite, with hydrogen replacing potassium, and a little iron equivalent to aluminum. Its formula, then, is HAlSi04 , or HgAlgSigO^, 

corresponding to muscovite, H2KAl3Si3012 . Rectorite, according to 

R. N. Brackett and J. F. Williams, has the same composition, plus 

an excess of water, which is driven off when the mineral is dried at 

110°. Possibly the mineral kryptotile, an alteration product of 

kornerupine or prismatine, may be a compound of the same order.3 

Silicates of this type, if their existence should be definitely established, would probably be found to be widely diffused and to play, an 

important part in the development olphyllite or mica schist. They 

should take up potassium from percolating solutions, forming muscovite a probability which deserves to be investigated with great care. 

"Upon complete dehydration all of the silicates in the list except 

collyrite and schrotterite should break down into mixtures of 

Al2Si05 and Si02 . Al2SiO5 represents empirically, the three minerals andalusite, kyanite, and sillimanite, which are isomeric but not 

identical. No other anhydrous silicate of aluminum alone is known 

to occur in nature. These three species, moreover, are all character- v 

istic of the metamorphic schists, and must have been formed in most i 

cases by some such process as that just indicated. Sometimes, however, other sources are to be assumed. For example, K. Dalmer 4 has 

described a phyllite containing muscovite and chlorite, which, by 

contact metamorphism, has been transformed into a tjiotite-andalusite 

schist. In this instance the andalusite seems to have been produced 

by a reaction between the two antecedent species. On the other hand, ; 

it has been shown by W. Vernadsky 5 that sillimanite is a normal constituent of hard porcelain, in which it is derived from kaolinite; and < 

also that kyanite and andalusite are convertible into sillimanite by 

heating to temperature of 1,320° to 1,380°. Kyanite often occurs I

1 Am. Jour. Sci., 3d set., vol. 42,1891, p. 16.

2 Bull. Soc. rain., vol. 22,1899, p. 27. See also K. S. barsen and E. T. Wherry, Jour. Washington A cad. ^ 

Sci., vol. 7,1917, p. 208. ' v

3 See J. Uhlig, Zeitschr. Kryst. Min., vol. 47, 1910, p. 215, and A..Sauer, Zeitschr. Deutsch. geol. Ciesell. x 

vol. 38, 18S6, p. 705.

4 Neues Jahrb., 1S97, Band 2, p. 156.

»Bull. Soc. rain., vol. 13,1890, p. 256. See also J. W. Mellor, Jour. Soc. Cbem. Ind., vol. 26, I907,p. 375.

\
METAMOEPHIC ROCKS. . 615

in mica schist, and also in long, bladed crystals embedded in quartz. 

All three species alter into mica, 1 so that here we have a group of 

facts which bear obviously upon the interpretation of metamorphic 

processes. We do not yet know, however, the conditions which determine the formation in a metamorphic rock of one or another of the 

three isomers. The chemical structure of the particular hydrous 

silicate from which andalusite, kyanite, or sillimanite has been 

derived probably has a distinct influence upon the reaction. Temperature, as shown by Vernadsky, must also be taken into account, and 

so, too, must pressure. The three minerals differ in density, and 

pressure may well help to determine which species shall form. The 

specific gravity of andalusite is near 3.2, that of sillimanite about 

3.25, and that of kyanite varies little from 3.6. Kyanite, then, would 

be likely to appear under the greatest pressures and andalusite under 

the least, other conditions being equal. The problem is complicated, 

however, by the fact that the same rock often contains more than one 

of these minerals, together with produ'cts derived from them. The 

argillite of Harvard, Massachusetts, according to B. K. Emerson,3 

contains andalusite inclosing silHmanite, both in every stage of alteration to muscovite. The argillites of this region, modified by intrusions of granite, show a zonal system of changes. Where the temperature was lowest, andalusite and sillimanite form. With more 

intense heat, staurolite and garnet appear. Influx of alkaline waters 

from the heated granite changes these species to muscovite, while 

nearest the granite feldspars develop.

Staurolite, HAl5FeSi2012 , specific gravity 3.75, is another mineral 

of the metamorphic schists, and one closely allied to the andalusite 

group. Its formation evidently requires the presence of iron in 

the sediments, and also conditions of temperature and pressure which 

could permit the retention of water. Garnet is one of its common 

associates, and so, too, are sillimanite and kyanite. Its most frequent matrix is mica schist; but its mode of formation is not yet 

clearly understood. Staurolite is always contaminated by inclusions 

of other substances, and it alters readily into mica.

With more iron and possible hydration, schists are formed containing chloritoid or ottrelite. Chloritoid has the formula 

H2FeAl2Si07 ; but that of ottrelite is not certain. The best evidence goes to show that the two minerals are alike in type, except 

that chloritoid is an orthosilicate, and ottrelite a trisilicate. On this 

supposition the two formulae become

A102Fe.SiO4 .A10H.H. AlO2Fe.Si308 .AlOH.H.

Chloritoid. Ottrelite.

1 The reported alteration of kyanite into steatite is most questionable. 1'robably a compact muscovita 

(damourite) has been mistaken for talc! 

> Bull. Geol. Soc. America, vol. 1,1889, p. 559.
616 DATA OF GEOCHEMISTBY.

Magnesium may replace iron to some extent, and in the Belgian 

ottrelites manganese plays a similar part. By dehydration, chloritoid would become AlO2Mg.Si04.Al, or Al2MgSi06, which is the 

formula of the aluminous constituent of augite and hornblende, 

and also of the imperfectly known mineral kornerupine. A relation 

between chloritoid and these silicates is therefore suggested, but 

what its real .significance may be is unknown. Broadly considered, 

chloritoid and ottrelite belong to a group of silicates intermediate 

between the micas and the chlorites, from either of which groups 

they may be derived, or into which they may alter. In the ottrelite 

schists of Vermont, according to C. L. Whittle, 1 chlorite is derived 

from ottrelite, and the latter mineral was one of the last to form. 

In the Belgian phyllites studied by J. Gosselet 2 mica sometimes 

replaces ottrelite. The formation of ottrelite after the other minerals of the schists was also noted by W. M. Hutellings 3 in a sericiteottrelite-ilmenite phyllite from Cornwall, and by J. E. Wolff 4 in a 

rock found at Newport, Rhode Island. In a collection of rocks from 

the Transvaal, J. Gotz 5 found ottrelite schist, andalusite schist, and 

an intermediate phase containing both ottrelite and andalusite.

Ottrelite and chloritoid are probably often confounded. At all 

events, chloritoid rocks have been less frequently described. C. Barrois 8 has reported them from the He de Groix, France; a. garnetchloritoid-quartz schist from Japan has been described by B. Koto;7 

and a rock from the province of Salzburg, Austria, studied by 

A. Cathrein, contained about 64 per cent of chloritoid, with 30 of 

quartz and some rutile. Other occurrences are well summed up by 

F. Zirkel,8 for both ottrelite and chloritoid. The abundant literature, .however, is mainly descriptive, and sheds little light upon the 

genesis of these minerals. The following analyses represent rocks 

characterized by the andalusite and chloritoid groups. All except 

one, by Klement, were made in the laboratory of the United States 

Geological Survey. 9 . 

1 Am. Jour. Sci., 3d ser., vol. 44,1892, p. 270.

2 Annales Soc. geol. du Nord, vol. 15, p. 185.

s Geol. Mag., 1889, p. 214.

4 Bull. Mus. Comp. Zool., vol. 16,1890, p. 159.

& Neues Jahrb., Beil. Band 4,1886, p. 143.

6 Annales Soc. g<k>l. du Nord, vol. 11,1884, p. 18.

' Jour. Coll. Sci. Japan, vol. 5,1893, p. 270.

8 Lehrbuch der Petrographie, 2d ed., vol. 3, pp. 282, 294,303-506.

9 On a remarkable andalusite rock in California see A. Knopf, Jour. Washington Acad. Sci., vol. 7, 

1917, p. 549.
METAMORPHIC EOCKS. 617

Analyses of uudalusite and chloritoid rocks.

A. Andalusite schist, Mariposa County, California. Analysis by W. F. Hillcbrand. Described by 

H. W. Turner, Seventeenth Ann. Kept. U. S. Geol. Survey, pt. 1,1896, p. 691. Contains quartz, biotitc, 

andalusitc, scricitc, and minor accessories.

B. Chiastolitc schist, Mariposa County, California. Analysis by G. Steiger. Described by Turner, 

' Bull. U. S. Geol. Survey No. 15.0, 1898, p. 342. Contains audalusite (chiastolite), sillimanite, mica, etc.

C. Andalusitc horn fols, Mariposa County. .Analysis by Steiger. Described by Turner, op. cit., p. 342. 

Contains quartz, andalusite, mica, etc.

D. Andalusito schist, Skamania County, Washington". Analyzed and described by W. T. Schallor, 

Bull. U. S. Geol. Survey No. 262, 1905, p. 105. Contains andalusite, 35 per cent; quartz, 32 per cent; 

Muscovite, 27 per cent; and minor accessories.

£. Kyanitc schist, Serra do Gigante, Brazil. Analysis by Hillebraud. Described by 0. A. Derby, Am. 

Jour. Sci., 4th scr., vol. 7,1899, p. 343... Consists mainly of tyanitc, chloritc, scricite, quartz, and rutilc.

F. Sillimanile schist, San Piego County, California. Analyzed and described by Schaller, Bull. No. 262, 

1895, p. 98. Mainly quartz, G9 per cent, and sillimanite, 31 per cent, neglecting water and minor accessories.

G. Chloritoid-phyllite, Liberty, Maryland. Analyzed by L. G. Eakins.' Called "ottrclite-phyllitc"' 

by G. H. Williams, but the characteristic mineral is chloritoid. See Bull. U. S. Geol. Survey No. 228, 

p. 59.

H. Ottrelitc schist, Moutherine, Belgium. Analyzed by C. Klement, described by A. F. llenard. 

Jlcnard's memoirs on the phyllites of the Ardennes (Bull. Mus. roy. hist. nat. Belgique, vol. 1,1882, p. 212;

vol. 2, 1883, p. 127; vol. 3, 1884, p. 230) are rich in data concerning rocks of this class. For this particular 

schist sec vol. 3, p. 255. It contains ottrelite, 40.11 per cent; sericite, 23.35 per cent; and quartz, 23.15 per 

cent.

SiO..................

FeO 3 ' MgO................

CaO................

K 6

H2 0-. ...............

H80+.. .............

TiO.................

> ZrO;.............-.. \ <~<

1 S03 .. .............. fa!- <?

F. ...:............. ci. ..................

MnO

BaO........ :.......

> SrO. ................

(Ni.Co)O...........

' FeS2 .-- --------- 

/

A

64.28

17. 28 

1.10

' 5.34

2.57

1.19

.91

2.93

.20

' 2.72

.65

.43

.27

.09

.10

Trace.

100. 06

B

62. 15

19. 34 

4.23

2.25

1.88

1.50

1.60

3.07

.19

1.79

.80

119

.13

99

.15

Trace.

.04

None

None.

100. 46

C

65. 10

17.77 

1.95

3.29

1.43

1. 38

2.25

2.45

.47

2.49

.72

1 21

.03

12

.14

None.

* nJ r\Ti &

100. 80

D

57.18

34. 10

.54

.28

.10

.63

.39

2:57

.69

2.02

.66

.02

.53

None

.04

.28

100. 03

E

38.32

28. 16 

2.24

4.02

12.04

.32

.16

1.11

.55

7.46

4.93

.09

Trace

Trace?

.47

. .16

.04

Trace.

] 00. 07

F

75. 54

18.65 

.35

.06

None.

.03

None.

None.

1.10

3.67

.48

.06.

Trace.

.10

100. 04

0

34. 92

32. 31 

10. 21

8.46

1.13

.36

2J2

1.87

} 5.29

3.37

.23

Trace.

100. 27

H

51. 93

27.45 

2.01

8.10

1.20

.1.8

.79

1. 60

| 3.92

.92

1. 05

.57

99.72

MICA SCHIST.

A great variety of other schists, corresponding to the variations in 

the sediments themselves, have.-received special descriptive names. 

Graphite schists, derived from carbonaceous shales; tourmaline 

schists, containing tourmaline, and garnet-mica schists are good 

examples. The commonest type of all, however, is the ordinary mica 

or sericite schist, which is essentially a mixture of quartz and mica,
618 DATA OF GEOCHEMISTRY.

with varying accessories. A paragonite schist contains the soda mica, 

paragonite, instead of the commoner muscovite. A shale passes into 

a slate; in that fine scales of mica develop, forming a phyllite", and 

with more complete recrystallization a mica schist is produced.' 

Mica schists also originate from the alteration of a granitic detritus 

consisting of quartz and feldspar,1 the latter mineral changing to 

muscovite, or, under undetermined conditions, to biotite. Chlorite, 

epidote, garnet, tourmaline, and feldspars are common accessory 

minerals in rocks of this class. The following analyses of mica 

schists were made in the Survey laboratory:

Analyses of mica schists.

A. Quartz-sericito schist, Mount Ascutney, Vermont. Analyzed by W. F. Hillebrand. Described by 

R. A. Daly in Bull. U. S. Geol. Survey No. 209,1903.

B. Sericite schist, Ladiesburg, Maryland. Analyzed by G. Steiger. Described by W. S. Bayley in 

Bull. U. S. Geol. Survey No. 150,1898, p. 317.

C. Sericite schist, Marquette region, Michigan. Analysis by Steiger. Described by C. R. Van Hise 

and W. R. Bayley, Mon. U. S. Geol. Survey, vol. 28,1895. Mainly sericite/and quartz.

D. Mica schist, Crystal Falls district, Michigan. Analyzed by H. N. Stokes. Described by IT. L. 

Smyth, Mon. U. S. Geol. Survey, vol. 36, 1898, p. 274. Contains biotite, quartz, some microcline, and 

magnetite.

E. Mica schist, near Gunflint Lake, Minnesota. Analyzed by T. M. Chatard. Contains biotite, quartz, 

feldspar (?), and pyrite, as reported by Van Hise.

F. Feldspathic mica schist, Mariposa County, California. Analyzed by Hillebrand. Described by 

H. W. Turner, Seventeenth Ann. Rept. U. S. Geol. Survey, pt. 1,1896, p. 691. Contains quartz, feldspar, 

biotite, muscovite, apatite, and specular iron.

SiO..........................

AUJ3 .------ -- - -----

Fe8 0s ...... ..................

FpO

MgO.........................

CaO.........-..... -'.........

K26. .........................

JJ2Q_j_

T102 . ......................... Zro2 . ......................:.

C02 . .........................

P o

so..........................

F

MnO.........................

BaO.........................

SrO. .........................

c.:..........................

FeSa .. .......................

A

90.91

4.18

.22

1.27

.37

.22

.77

.58

.06

.74

.28

.02

.18

.05

Trace.

Trace.

Trace. -

.10

.11

100. 06

B

57.24

23.48

3.19

4.87

.93

.09

1.18

3.55

.33

4.65

.08

OQ

None

99, 68

C

70.76

14.83

1.46

3.09

1.99

.36

.47

3.50

.09

2.70

.33

.26

99.84

D

64.71

16.43

1.83

3.84

2.97

.08

.11

5.63 .-31

2.79

.72

.02

Trace.

99.44

E

64.77

14. 45

1.84

4.54

2.34

2.33

1.37

5.03

.07

1.92

.60

.41

.20

.60

.11

100. 58

F

70.40

14. 70

.65

2.57

1.47

1.63

3.17

3.46

1Q

.91

.51

.05

.08

.09

Trace.

Trflfp

.15

100.03

1 See C. R. Van Hise, Bull. Geol. Soc. America, vol. 1,1899, p. 206, on schists from the Black Hills.
METAMORPHIC ROCKS. 619

Before leaving the subject of mica schist a word of caution may 

not be superfluous. It is often assumed that the mica in such a 

rock has been derived from the alteration of feldspathic particles 

contained in the original sediments, and this no doubt is frequently 

the case. The same process operates that is traced in the sericitization of an igneous rock, but it is not necessarily general. We have 

seen that muscovite can be formed from andalusite, for instance, 

and the latter probably from clay substance. In short, micas may 

form in a number of different ways, so that no single set of reactions 

can account for all of its occurrences. Sometimes its source can be 

determined, but not always.

Many schists contain tourmaline as an essential constituent. 

Dumortierite also occurs in them, perhaps more often than is commonly supposed. These species are borosUicates, and their generation 

is usually attributed to the agency of boron-bearing gases or vapors 

emitted from heated magmas along their contacts with sedimentary 

deposits. Boron compounds, and fluorine compounds also, exist in 

volcanic emanations, as was shown in Chapter VIII, and they probably produce, in many instances, the effects just ascribed to them. 

But here again caution is necessary. We do not know how widely 

boron and fluorine may be disseminated in rock-forming materials, for their determination in traces is very difficult and rarely 

attempted. Fluorine must be abundantly diffused as a constituent 

of the ubiquitous mineral apatite, and boron may be equally common. We observe its concentration in tourmaline, but we can not 

be positive as to its origin except in certain individual cases. One 

^ these seems to be the contact between mica schist and granite 

on Mount Willard, in the White Mountains of New Hampshire, as 

described by G. W. Hawes. 1 Here there are seven well-defined zones, 

as follows:

1. Argillitic mica schist, chloritic.

2. Argillitic mica schist, biotitic.

3. Tourmaline hornstone.

4. Tourmaline veinstone.

5. Mixed granite and schist.

6. Granite porphyry, biotitic.

7. Normal granite, hornblendic. This contains quartz, albite, orthoclase, hornblende, and some biotite. In the porphyry, biotite entirely replaces the hornblende.

The remarkably complete series of analyses by Hawes is given in 

the next table.

 i Am. Jour. .Sci., 3d sen, vol. 21, 1881, p. 21. 
620 DATA OF GEOCHEMISTRY.

Analyses of granite and mica schist near contact, Mount Willard.

A. The normal Albany granite. 

B. Porphyry, 3 feot from contact. 

C. Porphyry, 2 inches from contact. 

D. Tourmaline veinstone, on contact.

E. Tourmaline hornstone, 1 foot from contact. 

F. Schist, 15 leet from contact. 

G. Schist, 50 feet from contact. 

H. Schist, 100 feet from contact.

Si02 ......... ........

Al O

Fe203 ---- - ----------

FeO

MgO.. ...............

CaO. ................

Na20. ...............

K20. .................

H20........ ..........

Ti02 .. ...............

Bo03 ................

F

MnO.... .............

A

72.26

13.59

1.16

2.18

.06

1.13

3.85

5.58

.47

.45

Trace.

100. 73

B

73.09

12.76

1.07

4 98

.09

.30

3.16

5.10

73

.40

.08

101. 06

C

71.07

12.34

2.25

4.92

.19

.55

2.84

5.53

.72

.27

Trace.

100. 68

D

66.41

16.84

1.97

' 5.50

1.71

.37

1.76

.56

1.31

1.02

2.96

.25

.12

100. 78

E

67.88

14.67

2.37

3.95

1.29

.30

3.64

4.08

1.01

.93

.97

Trace.

.11

101. 20

F

66.30

16.35

.95

5.77

1.63

.24

1.11

3.40

3.02

1.28

Trace.

Trace.

100. 05

G

63.35

19.69

.72

5.48

1.77

T^rcipp

1.12

3.47

3.73

.1.00

.16

100. 49

II

61.57

20.55

2.02

4 98

1 97

.24

.68

4.71

4.09

1.10

.10

100. 61

The dehydration in passing from schist to granite is here very 

obvious, but the sudden appearance of boric oxide is more striking. 

That its concentration was brought about by pneumatolytic processes 

is the most reasonable hypothesis by which to account for its presence at the line of contact and its absence elsewhere. The mineralogical composition of the rocks D to H, as given by Hawes, presents 

a still clearer picture to the mind of the changes which have occurred:

Mineralogical composition of tourmaline rocks and mica schist, Mount Willard.

IMllQOAVTt'P

Chlorite. . .............................

Tourmaline. ..........................

D

50.03

" 1.94

2.86

45.95

E

50.82

} 29. 67

1.77

3.44.

14.92

F

45.15

j 43. 89

6.65

2.43

1.38

G

39.17

44.53

13.70

1.90

1.04

H

36.87

49.30

8.62

2.09

2.93

Here we see that the chlorite of the schist alters to biotite, by dehydration, as the contact is approached, and that the tourmaline has 

been formed largely at the expense of the micas. The absence of 

feldspar, which is abundant in the granite, is also noticeable. On 

the granite side of the contact the rocks are feldspathic; on the schistose side they are micaceous; at the contact neither feldspar nor mica 

is shown by Hawes's figures. Probably both minerals have contributed to the generation of tourmaline, which is related to both. Tourmaline often alters to mica, and tourmaline crystals are known inclosing cores of feldspar.
METAMORPHIC BOCKS. 621

GNEISS.

The gneisses form the largest group of metamorphic rocks, and 

represent both igneous and sedimentary formations. Some of them 

.are plutonic rocks, structurally modified; others are recrystalllzed 

sedimentaries. The term "gneiss," unfortunately, has been used in 

quite "different senses. For present purposes, J. F. Kemp's definition 1 may perhaps serve as well as any. He defines gneiss as a "laminated metamorphic rock, which usually corresponds in mineralogy 

to some one of the plutonic types." The gneisses "differ from schists 

in the coarseness of the laminations, but as these become fine they 

pass into schists by insensible gradations." Under this definition 

any plutonic rock may have its gneissoid equivalent, and C. H. Gordon 2 has proposed to name the gneisses accordingly. Thus we may 

have granitic gneiss, syenitic gneiss, dioritic gneiss, etc., including in 

the series foliated rocks derived from pyroxenite or peridotite. The 

common usage, however, is not quite so extreme, and the term 

gneiss is practically restricted to granular, laminated rocks analogous 

in composition to granite, syenite, or diorite. Chemically these 

gneisses differ very little from their igneous equivalents, but those 

derived from sedimentary rocks are likely to be relatively poor in 

alkalies and to contain minerals of calcareous origin. In some cases 

gneisses of sedimentary origin contain impurities of organic derivation, either coaly or graphitic. For example, in a gneiss from the 

Black Forest, H. Rosenbusch 3 found coaly particles which contained 

nitrogenous matter, undoubtedly derived from organic substances. 

A convenient aid to nomenclature is that offered by Rosenbusch,4 

who calls gneiss of igneous origin "orthogneiss," and that of sedimentary origin "paragneiss." There are also descriptive names of 

the ordinary character, which indicate mineralogical peculiarities. 

Chlorite gneiss, cordierite gneiss, tourmaline gneiss, garnet gneiss, 

epidote gneiss, sillimanite gneiss, albite gneiss, muscovite gneiss, biotite gneiss, two-mica gneiss, plagioclase gneiss, and orthoclase gneiss 

are names of this kind. The sedimentary varieties are also named 

genetically, as pelite gneiss, psammite gneiss, arkose gneiss, etc., 

according to the derivation of the rock from shaly, sandy, or arkose 

materials.

1 Handbook of rocks, 3d ed., p. 123.

*Bull. Geol. Soc. America, vol. 7,1895, p. 122

"Mitth. Grossh-bad. geol. Landesaristalt, vcl' 4, Helt 1,1900.

* Elemonte der GesteinsJehre, 2d ed. p. 484.
622 DATA OF GEOCHEMISTRY.

The following analyses of gneiss, with the exception of the Canadian example, were made by the chemists of the United States Geological Survey:

Analyses of gneisses.

A. Sedimentary gneiss, St. Jean de Matha, Quebec, Canada. Analysis by N. N. Evans. Described by' 

F. D. Adams, Am. Jour. Sci., 3d ser., vol. 50,1895, p. 67. Adams gives several other anlyses of gneisses.

B. Quartz-biotite-garnet gneiss, Fort Ann, New York. Analysis by W. F. Hillebrand. Reported by 

J. F. Kemp to contain quartz, garnet, biotite, orthoclase, some plagioclase, and zircon.

C. Average sample of mica gneiss, near Philadelphia, Pennsylvania. Analysis by Hillebrand. Described by F. Bascom, Maryland Geol. Survey, Cecil County volume, 1902, p. 116. Contains quartz, muscovite, feldspars, and minor accessories.

D. Gneiss from Dorsey's Run, Maryland. Analysis by Hillebrand. Described by C. R. Kcyes, Fifteenth Ann. Rept. U. S. Geol. Survey, 1895, p. 697. Probably of sedimentary origin.

E. Gneiss, probably sedimentary, Great Falls of the Potomac. Analysis by Hillebrand. Described by 

G. n. Williams, Fifteenth Ann. Rept. U. S. Geol. Survey, 1895, p. 670.

F. Biotite gneiss, Upper Quinnesec Falls, Menominee River, Michigan. Analysis by R. B. Riggs. 

Described by G. H. Williams, Bull. U. S. Geol. Survey No. 62,1890, p. 119. Contains biotite, soda orthoclase, quartz, and accessory sphene, zircon, and apatite...

G. Quartz-norite gneiss, Odessa, Minnesota. Analysis by H. N. Stokes. Described by W. S. Bayley 

Bull. U. S. Geol. Survey No. 150,1S98, p. 358. Contains quartz, plagioclase, and pyroxene, with accessory, 

biotite, garnet, pyrite, and magnetite.

SiOa ..................

AlaO..................

Fe203 .................

FeO.................

MgO..................

CaO. .................

Na20.................

K80......... ........

HaO ................ Hao+. ..:...........

Ti02 ... ...............

ZrOa :......... ........

coa ...................

P O

s?.v::::::v:::::::::

Fe7S8 ..... ...........

FeS2 .................

Cr808 ................

NiO. .......... .......

MnO..................

BaO.. ................

SrO. ..................

LiaO. .................

A

61. 96

19.73

4.60

1.81

.35

.79

2.50

f JL. oZi.

1.66

4.33

Trace.

99.55

B

65.09

16. 37

.93

5.64

2.40

2.40

3.31

1.93

.13

.58

.93

.01

.07

.11

.03

Trace.

.16

.03

TVflPia

Trace.

100. 12

C

66.13

15.11

2.52

3.19

2.42

1.87

2.71

2.86

.24

1.55

.82

(?)

.22

.03

Trace.

.20

Trace.

Trflpp

NOHG

99.87

D

48.92

16.57

4.21

9.18

5.98

9.69

2.47

1.56

. DO

Tvn rp

100. 26

E

78.28

9.96

1.85

1.78

.95

1.68

2.73

1.35

.12

.83

.70

.11

.08

.02

Trarp

Trace.

100. 44

F

67.77

16.61

2.06

1.96

1.26

1.87

4.35

2.35

} 1.69

.19

100. 11

G -

61.04

16.97

5.58

3.62

5.99

1.96

.55

\ At \ " 43

3.73

98.87

In a broad way the general order of change from clay to slate, 

shale, and. metamorphic schists is well shown by a series of averaged 

analyses compiled by C. R. Van Hise.1 The analyses chosen for 

combination were all of pelitic material.

i A treatise on metamorphism: Mon. U.S. Geol. Survey, vol. 47,1904, pp. 890,891,896. The data are all 

to be found in Bull. U. S. Geol. Survey No. 591,1910; the shale average on p. 23.
METAMOEPHIC EOCKS. 623

Average analyses of day, shale, slate, and schist.

A. Average of 12 analyses of clays and soils. 

B. Average or composite analysis of 78 shales. 

C. Average of 22 analyses of slates. 

D. Average of 5 analyses of schists.

Si02 . .........................................

A1303 . ........................................

Fe203 --------- ---------------------------- ---

FeO. ..........................................

MgO... ....... .......... .....................

CaO..........................................

Na20............ '.............................

KaO.. ..........................................

H20............ ......... ......................

Ti02 .. ........................................

C02 ...... :....................................

P O

S08 . .........................................

CL.... .........................................

F. ........................... ...............

MnO........ ..................................

SrQ......... ...... ............................

BaO. .........................................

Li.20. .........................................

FeS2 .. ........................................

C.... .........................................

A

54.28

14. 51

6.25

.77

2.99

5.04

1.21

2.12

8.41

.42

3.53

.09

.08

.02

.08

.24

100. 04

B

58. ,38

15.47

4.03

2.46

2.45

3.12

1.31

3.25

5. 02

.65

2.64

.17

.65

Trace.

None.-

.05

Trace.

.'81

100. 46

c

61.90

16. 54

2.73

3.63

2.99

1.07

2.57

3.15

3.84

.82

.59

.04

.03

Trace.

Trace.

Trace.

.01

Trace.

.11

.22

100. 24

D

65.74

17. 35

1.90

3.35

1.90

1.25

1.78

3.28

2.01

tt

None.

.12

.03

.07

.03

Trace.

.05

.58

99.99

In these figures, reading from clay to schist, we see a steady loss 

of water and of carbon dioxide. The latter has been gradually 

replaced by silica, and silica has also increased in proportion by its 

assumption as a cementing substance. Ferric iron, furthermore, is 

partly reduced to the ferrous state, and there is an apparent gain in 

alumina, which may be partly real, and so far due to cementation. 

The averages represent too few individual analyses to warrant any 

elaborate discussion of them, but they serve to illustrate the general 

tendency of the metamorphic processes.

METAMORPHIC LIMESTONES.

The metamorphism of limestone is effected by a variety of processes 

which are quite distinct in many particulars from those outlined in 

the preceding pages. A pure or relatively pure limestone may recrystallize into a compact marble, as shown in the chapter upon the 

sedimentary rocks. If it contains magnesium carbonate, dolomite is produced; and the presence of iron may determine the formation of mixed carbonates, such as ankerite or mesitite. These 

changes are of the simplest character and call for no further discussion now.
624 . DATA OF GEOCHEMISTEY.

But pure limestones are relatively rare. Sandy or argillaceous 

impurities are generally present, and also silicates produced by reactions with infiltrating waters. When limestones of this sort are metamorphosed, either dynamically or by contact with igneous injections, 

new minerals are generated, and the range of possibilities becomes 

very broad. Each impurity exerts its own peculiar influence, and 

operates to develop certain individual substances. Organic matter, 

for example, furnishes the material for graphite, which is very common in metamorphosed limestones. In the Adirondack region there 

are numerous beds of white, crystalline limestone, thickly spangled 

with brilliant hexagonal plates of graphite; and these localities are 

typical of many others.

When silica is the sole impurity of importance, it can crystallize as 

quartz, or react with the calcium carbonate to form the silicate, wollastonite. No more limpid crystals of quartz are known than those 

found in the cavities of Carrara marble. As for wollastonite, CaSi08 , 

it is often formed at contacts between limestone and igneous rocks, 

and it is also found disseminated through schists and gneisses. It 

must be remembered that shales and sandstones often contain calcareous matter, which undergoes the same transformations that the 

concentrated limestones experience. Calcium carbonate in a siliceous 

sedimentary rock may easily become the progenitor of wollastonite, 

garnet, scapolite, epidote, and other calciferous species. Carbon 

dioxide is expelled, and silicates are produced.

The development of wollastonite at an igneous contact, or, indeed, 

in any metamorphic rock, has peculiar geologic significance. E. T. 

Alien and W. P. White1 have shown that this mineral can be formed 

only at temperatures not exceeding 1,180°. Above that temperature 

it passes into the pseudohexagonal modification, which has often been 

prepared artificially, but. is unknown as a natural species. The 

presence of wollastonite, then, is evidence that the rock containing it 

had recrystallized at some temperature below the transition point. 

If that degree of heat were ever exceeded in a contact zone, we should 

expect the pseudohexagonal silicate to appear; since it does not, we 

are justified in assuming that this form of metamorphism is always 

effected at lower temperatures. We thus obtain a definite datum 

point in what has been called the "geologic thermometer."

The recrystallization of a sedimentary limestone containing limonitic impurities or hydroxides of aluminum will obviously produce 

inclusions of magnetite, hematite, or corundum. Magnetite has often 

been identified in crystalline limestones, and similar occurrences of 

corundum are not uncommon. The Burmese rubies, for example, are 

found in crystalline limestone, and sor too, are the red and blue

1 Am. Jour. Sci., 4th sen, vol. 21,1906, p. 89. The memoir is prefaced by a note from G. F. Becker, who 

points out the geologic bearing of the observations.
METAMOBPHIC ROCKS. 625

corundums of Newton, New Jersey. When alumina and silica are

,' present together, the reaction with calcium carbonate leads to the

. formation of various silicates, the conditions which determine the

appearance of each one, however, not being definitely known. Cin-

. namon garnet, vesuvianite, epidote, zoisite, and the scapolites are

among the species which appear most frequently. Gehlenite also

' occurs, but more rarely; for example, in marble, at the classical

locality of Monzoni in the Tyrol. 1 Metamorphosed limestone with

% inclusions of this class are common; for instance, in a belt extending

. from southwestern Maine to central Massachusetts. From two points

in this belt, at Raymond and Phippsburg, Maine, crystallized

anorthite has also been identified by analyses made in the laboratory

of the United States Geological Survey.2 The other feldspars as well,

albite, orthoclase, and the plagioclases, are known as contact minerals

or inclusions in crystalline limestones,3 and also the micas muscovite, 

biotite, and phlogopite. Phlogopite is essentially a mineral of this 

group of rocks, its formation and that of biotite requiring the presence 

of magnesium compounds. To form scapolites, sodium chloride is 

,; necessary, but that may easily come from percolating waters, or 

, from apatite. The alkalies required by the feldspars and micas may 

[ have a similar origin, or else be derived from impurities in the sediments from which the limestones were formed.

Nearly all limestones are more or less magnesian or ferruginous, 

facts which determine the formation of many metamorphic minerals. 

Magnesia, for instance, may crystallize by itself as periclase, and 

/ that species alters into brucite. Magnesia and alumina together give 

 ' rise to spinel. With silica, magnesian silicates, often ferriferous, 

may form, such as forsterite, olivine, enstatite, and hypersthene. 

^ With lime and magnesia together, monticeUite is produced, and also 

a wide range of pyroxenes and amphiboles. Augite, hornblende, 

diallage, diopside, actinolite, and tremolite are common in metamorphic limestones, and the minerals of the chondrodite-humite 

series are also characteristic of these rocks in many localities. The 

white, yellow, and brown magnesian tourmalines are other species of 

' this class. Furthermore, the olivines, pyroxenes, amphiboles, and 

' chondrodites alter into serpentine and talc, forming the ophicalcite 

marbles or verde antique. 4

' See C. Doelter, Jahrb. K.-k. geol. Reichsanstalt, 1875, p. 239. Doelter also reports hematite in these 

) marbles; and it has been identified by G. d'Achiardi in Carrara marble.

a Bull. U. S. Geol. Survey No. 220,1903, p. 27. Anorthite also occurs in the marble of Monzoni, in the 

Tyrol. See G. vom Rath, Zeitschr. Deutsch. geol. Gesell., vol. 27,1875, p. 379.

8 See, for example, G. Linck, Neues Jahrb., 1907, p. 21, on orthoclase from the dolomite of Campolongo.

«In Mon. U. S. Geol. Survey, vol. 46,1904, p. 221, W. S. Bayley described a talcose schist from the Aragon 

iron mine, Michigan, which was probably derived from a dolomite. An analysis of it, by G. Steiger, is 

given, and also its mineralogical composition. On the origin of secondary silicates in limestones see W. L. 

Uglow, Econ. Geology, vol. 8,1913, pp. 19, 215.'

113750° 19 Bull. 695 40
626 DATA OF GEOCHEMISTRY.

In a Scottish dolomitic marble containing forsterite, tremolite, 

diopside, and brucite, J. J. H. Teall 1 has observed a dedolomitization ; 

due to the silication of the double carbonate. That changes to 

diopside without change of ratios, and the partly altered rock shows l 

the two species in juxtaposition. The metamorphosis was effected 

by a plutonic intrusion, and where silica was deficient, brucite , 

appeared. Probably in the latter case magnesium carbonate was first 

reduced to periclase, MgO, which was later hydrated to brucite, 

Mg02H2 . The mixture of calcite and brucite is identical with the ' 

predazzite of the Tyrol.2 It may be noted that certain of the Adirondack limestones are regarded by J. F. Kemp 3 as having been 

originally siliceous dolomites, in which the silica and magnesia have 

segregated as pyroxene. In northern New Jersey, according to L. G. 

Westgate,4 a quartz rock and' a quartz-pyroxene rock have been 

formed by the metamorphism of limestones.

In addition to the minerals already named, the crystalline limestones contain many other less important species. Apatite, fluorite, 

rutile, perofskite, titanite, dysanalyte, and zircon are among them. 

By the reduction of sulphates, a considerable number of sulphides <. 

may be formed. At Carrara, for instance, G. d'Achiardi 5 found ; 

realgar, orpiment, sphalerite, pyrite, arsenopyrite, galena, chalcocite, * 

and tetrahedrite; and also native sulphur and gypsum. Pyrrhotite 

and molybdenite have been identified at other localities, and in the 

famous Binnenthal, in Switzerland, several rare sulphosalts occur\ 

in a crystalline dolomite. In short, the list of minerals now known 

as existing in metamorphosed limestones must comprise at least \ 

70 species., and possibly more.6

The rocks thus formed from limestones and dolomites, or from 

mixtures of these with siliceous material can vary from a nearly v 

pure, recrystallized carbonate to an indefinite aggregate of silicates 

alone. Even in a single bed the rocks may range from one extreme 

to the other. Analyses of such rocks, therefore, have little significance and are not often made. Three examples from the silicate side ^ 

of the group may serve to illustrate the variety of composition:

1 Geol. Mag., 1903, p. 513. A similar example is reported by F. H. Hatch and R. H. Restall, Quart. 

Jour. Geol. Soc., vol. 66,1910, p. 507. See also T. Crook, Geol. Mag., 1914, p. 339.

»See ante, p. 572.

»Bull. Geol. Soc. America, vol. 6,1894, p. 241. in the same volume, p. 263, C. H. Smyth discusses another, 

group of Adirondack limestones which were metamorphosed along contacts with gabbro. V,

«Am. Geologist, vol. 14,1894, p. 308. ^

6 Atti Soc. toscana sci. nat., Piaa, vol. 21,1905.

 Alistisgivenby'F.ZirkelinLehrbuchder Petrographie, 2ded., vol. 3, p.448. See also B. Lindemann, 

Neues Jahrb., Beil. Band 19,1904, p. 197. For the Ceylonese localities, see A. K. Coomara-Swamy, Quart. x 

Jour. Geol. Soc., vol. 58,1902, p. 399. J. F. Kemp and A. Hollick have described the crystalline limestones 

of Warwick, New York, in Annals New York Acad. Sci., vol. 7,1893, p. 644.
METAMORPHiC ROCKS. 627

Analyses of metamorphic silicate rocks.

A. Wollastonito gneiss, Amador County, California. Analysis by W. F. Hillebrand. Described by 

H. W. Turner, Seventeenth Ann. Rept. U. S. Geol. Survey, pt. 1,1896, p. 521. Consists mainly of wollastonitc, but garnet, quartz, and titanite are also present.

B. Prehnite rock, Black Forest, Germany. Analysis by C. Schnarrenberger. Described by H. Roscnbush, Mitt. Grossh. bad. geol. Landesanstalt, vol. 5, Heft 1,1905. Estimated to contain 46.2 per cent prehnite, 37.9 albitc, 13.8 actinohte, and 3.2 kaolin and nontronite. Probably formed from a marl containing 

34.5 per cent of carbonates with 65.5 silicates and quartz.

C. Garnet rock, Black Forest. Analysis by Schnarrenberger. Described by Rosenbusch, loc. cit. 

Probably derived from an original mixture of 48 per cent carbonates and 52 of silicates,- chic fly kaolin. Contains about 75 per cent garnet, 10 per cent soda-potash mica, and 15 per cent hornblende.

Si02 ........... .........................................

AI o

Fe2 08 ...................................................

FeO........... ........................................

McrQ

CaO ..................................................

Na.,0 ................................................. R n

H,0................................................... Ti'O

COo"

MnO.. . ...............................................

A

50. 67

6.37

.31

.50

.58

40.34

.14

.22

.39

90

.52

Trace.

100. 24

B

50.65

19.54

 3.34

IMnnp

3.92

16.11

3.91

.84

a 3. 10

TVflpp

100. 41

C

41. 01

18.50

6.57

11. 06

11. 02

10.31

.48

.31

1.18

100. 44

i a Loss on Ignition.

DIAGNOSTIC CRITERIA.

It is generally desirable, but not always easy, in the study of a

/ metamorphic rock, to determine whether it was of igneous or sedimentary parentage. For this purpose various criteria have been

 proposed, and chemical analysis furnishes some of them. On the 

chemical side the problem has been well discussed by E. S. Basting 

who points out a number of possibilities.

First, a study of analyses by the methods laid down in the quantitative classification of igneous rocks. In many cases the "norm" 

of a sedimentary rock is identical with that of some igneous rock, as 

shown in Washington's tables.2 In such instances no definite con-

, elusion can be reached from chemical evidence alone. But if the 

"norm" agrees with that of no known igneous rock, the analysis 

probably, but not certainly, indicates a sedimentary origin.

< Secondly, the manner in which the sedimentaries are formed 

suggests other chemical criteria. In most igneous rocks soda is an 

excess of potash, but decomposition changes the ratio, which, in 

sedimentary rocks, is often reversed. Dominance of potash over

i Jour. Geology, vol. 17, 1909, p. 445. See also J. D. Trueman, idem, vol. 20, 1912, p. 311, and rejoinder 

by Bastin, idem, vol. 21,1913, p. 103.

8 For example, an amphibolite derived from a granitic intrusion in limestone was shown by F. D. Adams 

(Jour. Geology, vol. 17, 1909, p. 1) to fall under the heading of auvergnose.
628 DATA OF GEOCHEMISTRY.

soda, then, is an indication of sedimentary origin. Dominance of 

magnesia over lime is another similar criterion, and any excess of 

alumina over the 1:1 ratio necessary to balance lime and alkalies 

is still another. Unusually high silica also affords presumptive evidence, which by itself is not conclusive, that a rock was derived from 

sediments. When two of these criteria are applicable to a metamorphic rock, there is a strong presumption established in favor of 

its former sedimentary character. When three apply, the conclusion is almost certain, and the concurrence of all amounts to positive 

proof. The analyses, however, must relate to fresh, unweathered 

material, and the criteria proposed apply only to silicates which might 

be metamorphosed plutonics or eruptives.

\
CHAPTER XV.

METALLIC ORES.

DEFINITION.

From a strictly scientific point of view, the terms metallic ore and. 

ore deposit have no clear significance. They are purely conventional 

expressions, used to describe those metalliferous minerals or bodies 

of mineral having economic value, from which the useful metals can 

be advantageously extracted. In one sense, rock salt is an ore of 

sodium, and limestone an ore of calcium; but to term beds of these 

substances ore deposits would be quite outside of current usage.

In the previous chapters of this work several forms of ore deposit 

have been described; and therefore the present chapter is in some 

measure supplementary. Its purpose is to deal with the subject 

more fully, and especially to give details concerning certain groups 

of ores which have been left out of account hitherto. Little has 

been said so far of the sulphides, and these are among the most 

important of economic minerals. Their genesis, their deposition in 

veins or pockets, their alterations and transferences are yet to be 

considered.

Upon the classification of or'e deposits there' has been much 

controversy, and various systems are in vogue.1 To the geologist 

or miner this question is most important; to the chemist it is less 

fundamental. Regarded from the genetic side, a large part of the 

field has been already covered; and it is easy to see that many ore 

deposits, if not all, fall under the headings of earlier chapters. For 

example, certain metallic ores occur as volcanic sublimates; others, 

like the titaniferous magnetites, are magmatic segregations, or local 

developments of igneous rocks. The sands and gravels that yield 

cliromite, tinstone, gold, platinum, etc., are detrital in character; 

many manganese and iron ores are sedimentary rocks, and from the

'.For recent papers and works on^this subject, see F. Po§epn#, Trans. Am. Inst. Min. Eng., vol. 23,1893, 

p. 197; J. H. L. Vogt, idem, vol'. 31,1901, p. 125; L. De Launay, Contribution a l'e"tude des gttesme'talliferes, Paris, 1897; J. F. Kemp, Ore deposits of the United States and Canada, New York, 1900; W. H. 

Weed and J. E. Spurr, Eng. and Min. Jour., vol. 75,1903, p. 256; R. Beck, Lehre von den Erzlagerstattcn, 

Berlin, 1903, and its English translation by Weed, New York, 1905; A. W. Stelzner and A. Bergcat, Die 

Erzlagerstatteri, Leipzig, 1904; C. R. Van Hise, A treatise on metamorphism: Hon. U. S. Geol. Survey, 

vol. 47, 1904, chapter 12; W. H. Weed, Trans. Am. Inst. Min. Eng., vol. 33,1903, p. 717; C. R. Keyes 

idem, vol. 30, 1900, p. 323; G. Gurich, Zeitschr. prakt. Geologic, 1899, p. 173; F. Beyschlag, P. Krusch, 

and J. H. L. Vogt, Die Lagerstiitten der nutzbaren Mineralien und Gesteine, Stuttgart, 1910. An English 

translation of vol. 1 appeared in 1914. On pp. 147-158 there is an elaborate discussion of the relative 

abundanceoftheheavymctals. Mineral deposits, New York, 1913, by W. Lindgren, is an excellent treatise 

on the subject. The annual reports of the U. S. Geol. Survey on mineral resources are rich in references 

to American localities.

629
630 DATA OF GEOCHEMISTEY.

latter nietarnorphic beds of magnetite or hematite are derived. Some 

ore bodies are residues from the concentration of limestones; others 

represent metasomatic replacements; others again are deposited or ' 

precipitated from solutions. In short, an ore body is simply a 

concentration of certain compounds of certain metals effected by 

processes with which we are already familiar. Since, however, each 

metal forms its own special compounds, and exhibits reactions 

peculiar to itself, it is best for chemical purposes to adopt a chemical 

classification, with which the broad, general principles can be con-elated. Each metal, therefore, will be treated by itself as a chemical 

individual and from a chemical point of view. Geologically it is 

important to know whether an ore deposit, laid down from solution, 

occupies the pores of a sandstone, a limestone cavern, or a fissure 

in the rocks; and it is also desirable to ascertain how these cavities 

or crevices were formed. To the chemist these considerations are 

for the most part irrelevant; but the conditions under which given 

compounds can be dissolved or precipitated are fundamental. What 

are the components of ore bodies? How -were they produced? 

In what way are they redistributed ? These are some of the questions 

which the chemist is expected to answer. The details must be < 

studied with reference to the individual metals; but some general ' 

considerations require attention first.

SOURCE OF METALS.

Although the immediate derivation of metallic ores is often from 

sedimentary rocks, the original source of the metals is to be sought \ 

in the igneous magmas.1 In igneous rocks of some sort the metals 

were once diffused, and their presence in eruptive material is easily 

detected. G. Forchhammer 2 in a series of rock samples found traces 

of silver, copper, lead, bismuth, cobalt, nickel, zinc, arsenic, antimony, and tin, to say nothing of the commoner metals, iron and manganese. Some of the same elements were found in the ashes of plants, 

which had extracted them from the soil. From these experiments '- 

Forchhammer concluded that ore bodies derived their contents from 

the neighboring rocks, a conclusion at which other investigators have 

also arrived. In an elaborate series of researches F. Sandberger,3 

found that the dark silicates of many rocks contained lead, copper, 

tin, antimony, arsenic, nickel, cobalt, bismuth, and silver, and upon J 

these facts he based his famous theory of "lateral secretion," That x 

is, Sandberger concluded that metalliferous veins derived their metallic contents by lateral leaching from adjacent rocks. This theory, T*

1 C. R. Keyes (Bull. Am. Inst. Min. Eng., 1910, p. 527) has suggested the possible derivation of heavy 

metals from meteoritic matter, especially meteoric dust.

» Pogg, Annalen, vol. 95, p. 60.

* Untersuchungen iiber Erzgange, Wiesbaden, 1882 and 1885. See also Neues Jahrb.-, 1878, p. 291, on 

copper, lead, cobalt, and antimony in basalt.
 METALLIC ORES. 631

however, was subjected to much criticism by A. Stelzner, F. PoSepny, 

and others,1 it being shown that in some instances at least the countryrocks might have received secondary impregnations from the veins. 

In other investigations, some earlier and some more recent, the dissemination of heavy metals in igneous rocks is clearly proved. A. 

Daubre"e 2 found determinate quantities of arsenic and antimony in 

basalt namely, 0.01 gram of As and 0.03 of Sb to the kilogram. 

The same metals, together with lead and copper, were detected by 

G. F. Becker 3 in the fresh granites near Steamboat Springs, Nevada. 

In the porphyries of Leadville, Colorado, W. F. Hillebrand 4 was 

able to determine lead. Out of 18 samples, taken at points distant 

from ore bodies, three contained no lead, the richest carried 0.0064 

per cent, and the average was 0.002 per cent of PbO. One porphyry 

yielded 0.008 per cent of zinc oxide, and a rhyolite contained 0.0043 

per cent. Silver was also found in these rocks in variable quantities, 

the best average giving 0.0265 ounce per ton. Gold, although sometimes present in traces, was generally not found. Traces of silver 

in diabase and diorite are reported by G. F. Becker 5 near Washoe, 

Nevada, and in the quartz porphyry of Eureka J. S. Curtis 6 found 

both gold and silver. Silver, according to S. F. Emmons,7 is also 

present in the eruptive rocks of Ouster County, Colorado, and J. W. 

Mallet found it in volcanic ash from two points in the Andes. Ash 

from Cotopaxi 8 carried silver to the extent of 1 part in 83,600, and 

ash from Tunguragua 9 yielded 1 part in 107,000. The latter quantity is very near Hillebrand's average for the Leadville porphyries, 

which is equivalent to 1 part in 110,000. In recent volcanic ash 

from Vesuvius E. Comanducci 10 found 0.0854 per cent of copper 

oxide, with 0.0038 of cobalt oxide.

In four rocks granite, porphyry, and diabase from the Archean 

of Missouri J. D. Kobertson u determined the following percentages 

of lead, zinc, and copper:

Pb, 0.00197 to 0.0068; average, 0.004. 

Zn, 0.00139 to 0.0176; average, 0.009. 

Cu, 0.00240 to 0.0104; average, 0.006.

The adjacent Silurian and Carboniferous limestones also contained 

these metals, but in slightly smaller proportions.

i A. Stclzner, Zeitschr. Deutsch. geol. Gesell., vol. 31,1879, p. 644, and rejoinder by F. Sandberger,idem, 

vol. 23,1880, p. 350. F. PoSepny, Trans. Am. Inst. Win. Eng., vol. 23,1893, pp. 247-254.

* Compt. Rend., vol. 32,1851, p. 827.

»Mon. U. S. Geol.'Survey, vol.13,1888, p. 350.

«Idem, vol. 12,1886, pp. 591-594.

6 Idem, vol. 3,1882, pp. 223-227. Assays by J. S. Curtis.

n Idem, vol. 7,1884, pp. 80-92.

i Seventeenth Ann. Kept. U. S. Geol. Survey, pt. 2,189C, p. 471. Assays by L. G. Eaklns.

s Chem. News, vol. 55,1887, p. 17.

» Proc. Koy. Soc., vol. 47,1890, p. 277. 

»o Gazz. chim. ital., vol. 36, pt. 2, 1900, p. 797. 

11 Missouri Geol. Survey, vol. 7,1894, pp. 479-481.
632 DATA OF GEOCHEMISTRY.

According to L. Dieulafait,1 who tested hundreds of rocks, zinc 

and copper are always to be detected, and they are also present in 

sea water. Copper salts, it will be remembered, are often found 

among the sublimates of Vesuvius, Stromboli, and Etna, and A. B. 

Lyons 2 observed copper sulphate in the crater of Kilauea. In 15 

Hawaiian lavas Lyons found from 0.07 to 0.48 per cent of copper 

oxide; in average, 0.18 per cent. G. Steiger, however, in the laboratory of the United States Geological Survey, analyzed a composite 

sample of 71 Hawaiian lavas and found only 0.0155 per cent of copper, showing that Lyons's figures are doubtless much too high. A 

large series of igneous and metamorphic rocks of British Guiana, 

analyzed by J. B. Harrison,3 also yielded appreciable quantities of 

copper, with sometimes other heavy metals. In 36 rocks examined 

6 contained no copper, 12 contained in it traces, and one, a feldspathie 

tuff, carried 0.13 per cent. The average percentage of copper for the 

entire series was 0.025. In 23 samples lead was sought for and found 

in 5 of them, the maximum percentage being 0.02 per cent. Eight 

rocks yielded silver, from 4 to 54 grains per ton of 2,240 pounds, in. 

average, 25.5 grains; and out of 29 rocks only 1 was free from gold. 

The highest gold was 43 grains per ton; the mean was 6.5 grains.

Even more positive evidence as to the wide distribution of the 

heavy metals was obtained by F. W. Clarke and G. Steiger. 4 Large 

composite samples of igneous rocks, clays, and river silt were analyzed, and in them copper, lead, zinc, nickel, and arsenic were determined. The results obtained, in percentages, appear in the following

table:

Percentages of heavy metals in composite samples.

A. The "red clay" of the oceanic depths. Composite of 51 samples, dredged from the sea bottom and 

representative of all the great oceans. The larger part of this material was collected by the Challenger 

Expedition. Determinations (by E. C. Sullivan) of CuO, ZnO, PbO, and As2Oii made on 1.50-gram 

portions.

B. "Terrigenous clays," from oceanic depths of 140 to 2,120 fathoms. Composite of 52 samples, namely 

4 "green muds" and 48 "blue muds," also mainly from the Challenger Expedition. Determinations made 

on 300-gram portions.

C. Composite of 235 samples of Mississippi silt. For the heavy metals 200-gram portions were taken.

D. Composite of 329 igneous rocks, all American. Determinations on 90-gram portions.

NiO....... ..................

AH O

PbO........................

CuO.........................

ZnO.........................

A

0. 0320

.0010

.0073

.0200

.0052

B

0. 0630

Trace.

.0004

.0160

.0070

C

0. 0170

.0004

. 0002

.0043

.0010

D

0. 00655

. 00074

. 00081

. 01167

. 00638

Average.

0 09QR

.0005

0099

.0130

004Q

1 Annales chim. phys., 5th ser., vol. 18,1879, p. 349; vol. 21,1880, p. 256.

2 Am. Jour. Sci., 4th ser., vol. 2,1896, p. 424. In andesite from Lautoka, Fiji, H. I. Jensen found 0.034 

per cent of copper, on an average. Chem. News, vol. 96,1907, p. 245. The same quantity was found by 

R. C. Wells in a sample of the Columbia River basalt, which covers a large area.

1 Kept, on petrography of Cuyuni and Mazaruni districts, Georgetown, Demerara, 1905. On gold and 

silver in diabase, French Guiana, see E. D. Levat, Annales des mines, 9th ser., vol. 13,1898, p. 380; and 

also in Min. Industry, vol. 7, p. 315.

4 Jour. Washington Acad. Sci., vol. 4,1914, p. 58.

\
METALLIC ORES. 633

In the foregoing pages only a part of the available evidence has 

been presented, but it is enough to establish the point at issue. The 

heavy metals are widely disseminated, both in old and in recent 

igneous rocks, from which, by proper methods, they can be concentrated. In the laboratory of the United States Geological Survey 

such metals as nickel and chromium are often quantitatively estimated, as shown in the table on page 28. Copper is determined 

in exceptional cases only, but indications of its presence are frequently observed. Of its wide distribution hi igneous rocks there is 

no shadow of a doubt. From the rocks all of these metals are 

leached, and traces of them accumulate in the sea. From the sea 

water the heavy metajs are to some extent absorbed by living organisms, and the presence of copper in oysters has long been known. In 

a recent investigation by A. H. Phillips 1 copper, zinc, iron, manganese, and in two instances lead were detected in the soft parts of 

mollusks, crustaceans, and other marine invertebrates, although in 

very minute proportions. Whether these observations have any 

direct bearing upon the formation of ore bodies is very doubtful. 

The heavy metals also appear in many mineral springs,2 a fact which 

is capable of more than one interpretation. Such a spring may derive 

its contents from dispersed material, or it may rise from a segregated 

body of ore; its composition, therefore, merely tells us that the metalliferous compounds are more or less freely soluble. The traces of 

these metals are as a rule more easily detected in the sediments than 

in the waters themselves that is, they become concentrated in the 

insoluble precipitates that spring waters often deposit.

That sulphides of the heavy metals can be dissolved in or decomposed by water alone, there is some experimental evidence. P. De 

Clermont and J. Frommel 3 found that sulphides of iron, nickel, 

cobalt, antimony, arsenic, silver, and tin were attacked by boiling 

water, hydrogen sulphide being driven off. Some were acted upon 

even at temperatures below 100°; As2S3 at 22°, FeS at 56°, AgS2 at 

89°, and Sb2S3 at 95°. The sulphides of copper, zinc, mercury, cadmium, gold, platinum, and molybdenum, treated in the same way, 

gave no evidence of decomposition.

C. Doelter's experiments 4 were conducted differently. The natural sulphides, in fine powder, were heated with water in glass 

tubes to 80° during periods of 30 to 32 days. In a second series of 

experiments lasting 24 days, a solution of sodium sulphide was used

1 Carnegie Inst. Washington, Pub. No. 251,1917, p. 89. For other citations see Clarke and Wheeler, Prof. 

Paper U. S. Geol. Survey No. 102,1917, p. 51.

2 See ante, p. 184, for example.

8 Annales chim. phys., 5th ser., vol. 18,1879, p. 189.

< Min. pet. Mitt., vol. 11,1890, p. 319. Research continued by Q. A. Binder, idem, vol. 12,1891, p. 332.
634 DATA OF GEOCHEMISTRY.

instead of water. The following percentages of material passed into 

solution:

Material dissolved from natural sulphides in water and in sodium sulphide solution.

Galena. .....................................................

Stibnite. ...................................................

Pyrite. ....................................................

Bournonite. .................................................

Water 

alone.

1.79

5.01

2.99

.025

.1669

2.075

1.5

With 

sodium 

sulphide.

2.3

All.

10.6

.62

.11

3.9

3.2

In most of these experiments, but not in all, the dissolved substance 

had the same composition as the original material. That is, the 

minerals dissolved as such, without decomposition a conclusion that 

was strengthened by the observation that in most cases new crystallizations were formed. 1

According to Doelter, then, sulphides may be dissolved and recrystallized from water alone. This is important, but not a complete 

indication of what occurs in nature. Natural waters, as we well 

know, are not pure, but charged with various dissolved salts, which 

exert a varying influence upon the solution of sulphides. 'They also 

contain carbonic acid, and sometimes also the stronger mineral 

acids; and surface waters carry dissolved oxygen. All of these 

impurities take part in the solution, concentration, and redistribution of metallic ores, and their effects are furthermore varied by 

differences of temperature. A hot water, rising from great depths 

and free from oxygen, produces one set of changes; a cold surface 

water, highly oxygenated, acts quite differently. Direct solution of 

ores is more likely to occur in the one case, oxidation to soluble salts 

is commonly evident in the other. The main fact, that solution is 

effected in one way or another, is well illustrated, not only by the 

composition of mineral springs, but also by the analyses of mine 

waters. For example, in a water from a mine shaft near Broken 

Hill, J. C. H. Mingaye 2 found, in grains per gallon, 8.40 copper, 

10.67 zinc, 21.82 cobalt, and 6.71 nickel. The water was strongly 

acid. Two analyses of mine waters from the Comstock lode, cited

i Still more recently O. Weigel (Nachrichten K. Gesell. Gottingen, Math.-phys. Elasse, 1906, p. 525) has 

determined the solubility in pure water of the sulphides of Pb, Hg, Ag, Cu, Cd, Zn, Ni, Co, Fe, Mn, Sn, 

As, Sb, and Bi. All were slightly soluble. For an abridgment of this paper, see Zeitschr. physikal. Chemie, 

vol. 58,1907, p. 293.

» Records Geol. Survey New South Wales, vol. 8,1909, p. 292.
METALLIC ORES. 635

by J. A. Reid/ are accompanied by assays for gold and silver. The 

more concentrated of these waters contained 188. 09 milligrams per 

ton of water in silver, with 4.15 milligrams in gold. This water was 

also strongly acid.

An extraordinary water from a mine tunnel at Idaho Springs, Colorado, analyzed by R. C. Wells in the laboratory of the United States 

Geological Survey, contained nearly 8 grams per liter of an oxide 

of molybdenum, probably the so-called soluble molybdenum blue. 

The water also contained a large amount of free sulphuric acid, and 

was a dark greenish blue in color and only transparent in very thin 

layers. The molybdic compound formed about 25 per cent of the 

total impurity. The specific gravity of the water was 1.031 at 25° C. 

The analysis, stated in grams per liter, is as follows:

Anith/S'ix of molybdic mine ivaler.

Fe". ...............

Fe'"... .............

AL. ................

Ca. ...................

Mg.......... .......

Na..................

K. .........:.......

.. ........ 2.01

............. 1.75

97

............. .50

............. .73

9(\

............. 14

H(acid)..............

Mo02 .. .............

Mo03 ...............

QA

ci........... ........

............ 0. 13

........... Trace.

............ 7. 98

............ 18.26'17

39. 20

This water evidently originated from the oxidation of molybdenite, 

the rare mineral ilsemannite, of uncertain composition, having been 

.first formed. 2

Other typical mine waters are represented in the following table 

of analyses, which, when not otherwise stated, were made in the 

laboratory of the United States Geological Survey. All are reduced 

to the uniform ionic standard and to parts per million.3

1 Bull. Dept. Geology Univ. California, vol. 4, pp. 189, 192. In the same volume, p. 332, A. C. Lawson 

gives an analysis of water from the Ruth mine, Kobinson district, Nevada. According to W. 3. Sharwood 

(Econ. Geology, vol. 6,1911, p. 742) the water of the Homestake mine, South Dakota, also contains a trace ' 

of gold.

« For recent analyses of ilsemannlto see W. T. Schaller, Jour. Washington Acad., vol. 7,1917, p. 417; and 

H. F. Yancey, Chem. and Met. Engineering, vol. 19,1918, p. 186.

» For other analyses of mine waters, see J. A. Phillips, Philos. Mag., 4th ser., vol. 42, 1871, p. 401; A. 

Schrauf, Jahrb. K.-k. geol. Beichsanstalt, vol. 41,1891, p. 35; A. C. Lane, Proc. Lake Superior Min. Inst., 

vol. 12,1906, p. 97; W. H. Emmons and G. L. Harrington, Econ. Geology, vol. 8, p. 653,1913; W. J. Sharwood, idem, vol. 6, p. 742, 1911; C. R. Van Hise and C. K. Leith, Mon. U. S. Geol. Survey, vol. 52, pp. 

543, 579, 1911; J. S. Maclaurin, 45th Ann. Rept. Dominion Laboratory, New Zealand, 1912, pp'. 47, 48. A 

few others have already been cited in the chapter on mineral springs. F. PoSepny^ (Trans. Am. Inst. Min. 

Eng., vol. 23,1893, p. 240) has tabulated the occurrences of Sn, Sb, Cu, and As in mineral waters. In Trans. 

Am. Inst. Min. Eng., vol. 52, 1916, p. 657, ten analyses of zinc-bearing mine waters by G. A. Waring are 

given. In Bull. U. S. Geol. Survey No. 625, W. H. Emmons cites 41 typical analyses of mine waters. On 

the composition of watersfrom mines of sulphide ores see E. T. Hodge, Econ. Geology, vol. 10,1915, p. ]23.
636 DATA OF GEOCHEMISTRY.

Analyses of mine waters.

A. Water from 500-foot level of Geyser mine, Ouster County, Colorado.

B. Same locality as A,from the 2-000-foot level. Contains also traces of Br, I, F,and B^?. Analyses 

A and B by W. F. Hillebrand. Discussed by S. F. Emmons, Seventeenth Ann. Kept. U. S. Geol. Survey, 

pt. 2,1896, p. 462.

C. Water from the Stanley mine, Idaho Springs, Colorado. Analyses by L. J. W. Jones, Proc. Colorado 

Sci. Soc., vol. 6,1897, p. 48.

D. Hot water from a bore ho.le 2,316 feet deep, in the Mizpah mine, Tonopah, Nevada. Analysis by 

R. C. Wells. Bicarbonates here reduced to normal carbonates.

E. AVater from St. Lawrence mine, Butte, Montana. Analysis by HiUebrand.

F. Water from Mountain View mine, Butte, Montana. Analysis by Hillebrand. Contains a trace of 

arsenic.

G. Water from Alabama Coon mine, Joplin district, Missouri. Analysis by H.~N. Stokes.

H. Water from the Victor mine, Joplin district. Analysis by H. A. Buehler and V. A. Gottschalk, 

Econ. Geology, vol.5,1910, p.28. The authors also give three other analyses of Joplin mine waters. Their 

study relates to the oxidation of sulphide ores, and they tod that pyrite or marcasite accelerates the reactivity of other sulphides. Two more analyses of zinc-bearing mine waters from the Joplin district are 

reported by C. P. Williams, Am. Chemist, vol. 7, 1877, p. 286. See also E. H. S. Bailey, Water-Supply 

Paper U. S. Geol. Survey No. 273,1911, p. 349.

I. Water from the Burra Burra mine, Ducktown, Tennessee. One of a series of six analyses of mine 

waters by R. C. AVells.

J. AVater from the Rothschonberger Stolln, Freiberg, Saxony, at its point of discharge into the Triebisch 

Valley. Analysis by Frenzel. Described by H. Miiller, Jahrb. Berg- u. Hiittenw. Konig. Sachsen, 1885, 

p. 185. Discharges 479 kilograms of ZnO daily, or 175,024 kilograms per annum.

'

ci........... ...............

so4.. .......................

on

NO

POI.':::.::::::::::::::::::::

Nfl

Li.........................

Ca.. ......................

Sr.. ........................

Mg................... ......

Al.. ........................ W"

Fe".... ....................

Mn.........................

Ni ... . .............

Co.........................

Cu......... ................

Zn......................... cd.........................

Pb........................

Sn... ........ ...............

Si02 .......................

Total C02 . ...........

A

7.9

43.2

no. 5

10.6

36.4

Trace.

37.4

12.25

o.4

\ '

.8

Trace.

9 .

Trace.

25.9

286. 25

B

186. 40

161. 70

1, 513. 44

1.60

Trace.

198. 00

719. 45

2.85

146. 41

1.95

177. 67

1.06

| 3.50

-.57

.02

.34

1.35

24.42

3, 140. 73

2, 528. 46

C

 8.16

2, 039. 51

70.00

106.27

is?, is

93.50

3 19

1fi4 82

3.44

155. 58

77.05

49.66

43.80

3, 002. 06

D

35.6

327.2

87.9

Trace.

3.4

148.8

68.8

6.3

.7

I '

Trace.

64.8

744.2 

121.2

E

13.0

2, 672. 0

Traro

13 1

39.6

nqo e

61.6

oq c

159.8

19 0

1 5

/ ' 5

59.1

852.0

41.1

17.0

47.7

4. 204. 5 

23.7

, 0.8 per million.
METALLIC OEES. 

Analyses of mine ivaters Continued.

637

01..........................

S04 .. .......................

POK;:.Y:.:::::::::::::::::::

Na. .......................

Li.........................

Ca.........................

Me. ........................

AT............. ............

Fe"'.. ......................

Fe". .......................

Mn.. .......................

Ni. ........................

Co.........................

Cu.........................

Zn.........................

Od.........................

Si02 . ......................

H3SO4 . free. ...............

Total CO2 .. ...........

F

17.7

71, 053. 3

1.5

6.8

41.7

TVnpp

307.7

149.2

85.2

49.8

13.2

3.5

4.6

45, 633. 2

411.2

67.4

117, 846. 0 

8.9

G

2.7

6, 153. 2

49.9

None

CMC Q

25.2

142.1

| 474. 6

1.7

3.7

2. 412. 0

9.0

107.6

9, 727. 5

H

3.65

1, 647. 58

Q Oft

13.02

260. 45

48.60

11.70

142. 80

345. 10

23.20

251. 70

2, 751. 00 

87.0

I

0.1

6, 664. 0

19.8

23.4

67.6

40.6

433.0

2, 178. 0

.2

. 312.1

199. 8

55.6

129.6

10, 123. 8

J

12. 4

124.8

46. 4

14. 5

1 r < > 6. o

S. 9

 J8.0

o 231. 6

a 244.9 in the original.

Analysis A represents vadose or superficial water; B, water from 

the deep circulation. The difference in concentration is remarkable. 

Water F is essentially a strong solution of copper sulphate, formed 

by oxidation of sulphides. Such waters are common in copper mines, 

and from them the copper can in many cases be profitably recovered. 

The Ducktown water is also noteworthy on account of its high proportion of ferrous sulphate. 1

The phenomena of solution, then, are evidently of supreme importance in the concentration of metallic ores. This statement can be 

given the broadest possible construction. A magmatic ore owes its 

segregation to a relative insolubility in the magma. A residual or 

detrital ore is formed, at least in part, by the removal from a rock 

of the more soluble constituents, the less soluble thereby becoming 

concentrated. Sedimentary ores are deposited from solutions, either 

directly or by precipitation, and metalliferous veins represent another aspect of the same processes. The original magmatic rocks 

are separated, by solution or leaching, into different fractions; and 

then, by direct deposition, by precipitative reactions, or by metasomatic replacements, ore bodies, and especially vein fillings, are formed. 

In most cases, probably, the final, workable deposit is the outcome 

of a series of concentrations, the result of several interdependent processes, but the underlying principles are the same. By differences of 

solubility, the constituents of the earth's crust are separated from one

1 For the remarkable calcium chloride waters of the Lake Superior copper region, see ante, p. 181.
638 DATA OF GEOCHEMISTRY.

another, to be laid down again under different conditions and in 

different places.

The two fundamental facts with which we now have to deal are 

the dissemination of the heavy metals hi the igneous rocks and the 

circulation of the underground waters. Descending, meteoric waters 

effect some of the observed concentrations; lateral secretions bring 

about others, and waters ascending from unknown depths play their 

part in the complex of phenomena. Whether these waters have a 

common origin or not is unessential to the present discussion. It is 

held by some writers, notably by Suess, that certain of the ascending 

waters arise from the original magma and now see the light of day 

for the first time. This conception has been correlated with the 

notion that the heavier metals, by virtue of their high specific gravity, 

are concentrated at great depths, from which ^the solvent waters 

bring them to the surface.1 Speculations of this sort are interesting, 

but not necessary for present purposes. The fact that the ascending, 

deep-seated waters are hot, and therefore more powerful as agents 

of solution, is, however, most pertinent.

The general principles governing the circulation of the underground waters have been elaborately discussed by Van Hise,2 and 

need not be especially considered here. The arguments are mainly 

physical and geological, and have only partial relation to chemistry. 

These waters, ascending, descending, or lateral secreting, tend to 

gather into trunk channels, in which, sooner or later, some of the 

substances held in solution are deposited. Ore bodies are thus 

formed, but only in exceptional cases. By far the greater number of 

veins are barren of heavy metals, or at least so nearly barren that 

they need not be further described. Once in a while concentrations 

of h^eavy metals are produced, and in most cases, but not invariably, 

they appear in association with rock of igneous .origin.3 This association seems to be fundamentally important, so far as the metalliferous veins are concerned, and the problem of their origin is the 

only one now before us. Magmatic, .sedimentary, and detrital ores 

fall under other headings.

An -igneous effusion forces its way to the surface of the earth, 

thereby displacing and fracturing the rocks which were in its path. 

As it cools and shrinks, other crevices are formed, through which

1 See L. De Launay, Contribution al'6tude des gites metalliferes, 1897, p. 6; and F. PoSepn^. Trans. Am. 

Inst. Min. Eng., vol. 23, 1893, p. 206. J. H. L. Vogt (Trans. Am. Inst. Min. Eng., vol. 31, 1901, p. 125) 

and also C. R. Van Hise (A treatise on metamorphism: Mon. U.S. Geol. Survey, vol. 47,1904) dissent from 

this view. The importance or magmatic waters as vein fillers has been recently argued by A. C. Spencer, 

Trans. Am. Inst. Min. Eng., vol. 36,1906, p. 364. The magmatic waters are regarded by J. E. Spurr (Econ. 

Geology, vol. 2, 1907, p. 781) as residues representing the last stage of magmatic differentiation; and in 

them the heavier metals and other vein-filling materials are supposed to be concentrated.

2 A treatise on metamorphism: Mon. U. S. Geol. Survey, vol. 47,1904, chapter 12.

a See Beck's work on ore deposits. Also papers by J. F. Kemp, Trans. Am. Inst. Min. Eng., vol. 31, 

1901, p. 169; vol. 33,1903, p. 699; J. E. Spurr, idem, vol. 33,1903, p. 288; W. H. Weed, idem, vol. 33,1903, 

p. 715; W. Lindgren, idem, vol. 30,1900, p. 578.
/ METALLIC ORES. 639

*/

also the mineralized waters can find a passage. These waters may 

be partly magmatic, brought with the igneous matter from the 

depths, or partly gathered from sedimentary material; but whatever 

may have been their source, they are heated, and therefore their 

solvent power is increased. During solidification, moreover, any 

> water that was entangled within the molten rock is extruded, carrying its dissolved load into the open channels. . A blend of waters from 

different sources deep seated, superficial, and magmatic enters

J the crevices of the rocks, each part of the mixture contributing its 

share to their filling. The solutions thus commingled are, moreover, not all alike, and therefore chemical reactions, such as double 

decompositions and precipitations, become possible between them. 

The frequent concentrations of ores at points of intersection between 

two veins may possibly indicate reactions of this kind. These 

changes are also complicated by reactions between intruded rock and 

the formations which it has penetrated, and they vary with variations in the latter. Some ore deposits are evidently produced in 

zones of contact metamorphism, especially in limestones, and the ores 

are then associated with such characteristic minerals as garnet, wol-

") lastonite, pyroxene, vesuvianite, and so on. 1 Aqueous solutions take

/ part in some of these changes, penetrating the walls of the contact 

and bringing about metasomatic replacements. 2

In the ascent of an igneous intrusion, with its entangled waters, the 

so-called pneumatolytic processes appear to have some importance.

/ The molten magma contains gases and vapors other than the vapor 

of water, as we know from the phenomena of volcanism. Whether 

these gases are occluded, or evolved by reactions within the magma, is 

not material to the present discussion. In volcanic craters they form 

sublimates containing copper, iron, and other heavy metals, which 

often consist of chlorides. Ammonium chloride, fluorine compounds, 

and boric acid, which last is volatile in steam, are other common sub-

** stances in volcanic emanations.

In ore formation the magmatic chlorides and fluorides probably 

have definite functions. In the molten rock they convert some part

*\ of the heavy metals into compounds which are volatile at high temperatures and which therefore tend to gather at the margins of the 

intrusions. There, being soluble in water, they pass into solution, 

and so find their way into the open channels wherein deposition takes 

place. With them other substances are deposited, forming the 

gangue minerals calcite, quartz, barite, fluorite, etc. in even larger 

amounts.

1 See W. Lindgren, Trans. Am. Inst. MIn. Eng., vol. 31,1901, p. 226.

2 Lindgren, idem, vol. 30, 1900, p. 578. These contact deposits and metasomatic alterations are fully

> described by Lindgren, who gives excellent summaries of the earlier literature. Later papers by Lindgren

on ore deposits are in Econ. Geology, vol. 2,1907, pp. 105, 743. See also his volume on mineral deposits,

*' already cited u

4,
640 DATA OF GEOCHEMISTRY. V

The heavy metals, however, are notlaid down as chlorides orfluorides 

except in rare instances; but in other forms chlorine and fluorine have 

acted as primary agents in bringing about their concentration, 

water tends to hydrolyze the salts thus formed, other solutions 

react with them, and quite different compounds are precipitated. .In 

the case of tin the oxide is commonly produced; the other metals , 

tend to appear as sulphides. Chlorine and fluorine act only as temporary carriers of the metals, and when their work is done they enter 

.into other combinations. Fluorine remains in a gangue mineral, i 

fluorspar; the chlorine returns into circulation as a soluble alkaline 

chloride; that is, as common salt. I cite only the simplest cases.

The pneumatolytic process thus outlined is largely inferential and 

may not be entitle'd to much weight. Neither is it exclusive. We 

know that certain sulphides are magmatic minerals, and we have seen 

that they can be either dissolved or decomposed by heated waters. 

In the depths they would pass into solution with some evolution of 

hydrogen sulphide, as shown by the experiments of De Clermont and 

Frommel and in the researches of Doelter. The dissolved sulphides 

would be redeposited by the cooling solutions, and the hydrogen sulphide would serve as a precipitant for the chlorides or sulphates 

which we assume to have been otherwise formed. The phenomena \ 

must also vary as the magmatic waters happen to be alkaline or acid, 

solution predominating in the one case and decomposition in the 

other. Carbonated waters are to be regarded as intermediate waters 

from this point of view, which decompose sulphides at first and gen- \ 

erate actively solvent solutions that come into play later. That is, a 

water containing alkaline carbonates and free carbonic acid should 

decompose the sulphides at great depths under the conditions there 

existing of high temperature and pressure.

Alkaline sulphide solutions would thus be formed, in which the 

sulphides of the heavy metals are variably soluble. In such solutions 

the sulphides of tin, arsenic, and antimony dissolve freely and other <-' 

sulphides in very much smaller amounts. A partial separation should 

be thus effected, exactly as in the operations of an analytical laboratory. These, suppositions, however, need to be tested by experiment; > 

until that has been done, they are only tentative. s

We can not assume that all metalliferous veins are alike in origin, 

and it is therefore unwise to generalize too sweepingly about them. 

We may, nevertheless, imagine a typical case and follow a series of 

concentrations throughout its probable course, beginning with the 

still unconsolidated magma. But magmas are different and yield ^ 

very dissimilar rocks. One is mainly feldspathic, another mainly 

olivine, and a third solidifies to a pyroxenite. More commonly they 

are complex mixtures, and in their cooling a certain amount of differ- . 

entiation, the segregation of certain parts, takes place. v
METALLIC ORES. 641

In order to form an ore body the magma must probably be richer 

in heavy metals than is usually the case. We know that several sulphides exist as magmatic minerals and that they are more abundant 

in some places than in others, varying in this respect just as the feldspars do. In other words, the magmatic constituents are not uniformly distributed throughout the crust of the earth. A magma, 

then, with more than the average proportion of sulphides, rises to the 

surface of the earth and cools progressively. In so doing some segregation of sulphides must take place, and they become thereby concentrated at the margin of the cooling mass. The product of concentration may itself appear as a large and distinct ore body, like 

the Norwegian pyrrhotites, or it may be relatively trivial; but in 

either case a first step has been taken.

Upon this primary concentration the circulating waters may act, 

and indeed have been acting from the instant that cooling began. 

Obviously, the waters which first operate are either those which were 

occluded in or generated from the rising magma or which it encountered earliest in the course of its upward movement. These, therefore, are ascending waters, whatever their previous history may have 

been. Their condition at first is that of highly superheated and 

compressed steam, for they are above the critical temperature of water 

and can not liquefy until they have partly cooled. Below 365° they 

become possibly liquid and heavily charged with matter dissolved 

/from the magma and the adjacent rocks. Solids and gases are both 

dissolved, and the ascending solution, slowly cooling and mingling 

with other solutions as it rises, gradually deposits its burden. Its 

channel becomes filled with various minerals, ores, and gangues, and 

thus a second stage in the concentration is completed.

Of this process in detail we can not form a clear mental picture. 

The superheated solutions, formed at the beginning of the ascent, 

are something of which experience tells us very little. We know 

that water, at or above its critical temperature, attacks silicates 

vigorously, and that it will even, as shown by C. Barus,1 form a 

mutual solution with glass. But how it will act with molten rock 

under pressure, what sort of a solution it will then develop, we do not 

.know. It is fair to infer that the reactions will be both energetic 

and complex, and that supersaturated solutions are likely to be produced; but the waters which ultimately rise to the surface as thermal 

springs are at moderate temperatures and have lost much of their 

load. Furthermore, they have been modified by other waters, and 

reactions may have occurred of which no certain trace remains. If 

organic matter has reached the solutions at any point, sulphates 

must have undergone reduction to sulphides, and the latter comi See ante, p. 291. 

113750° 19 Bull. 695 41
642 DATA OF GEOCHEMISTRY. \

> pounds would therefore appear in more than one generation and in 

larger quantities. A multitude of different reactions are conceivably 

possible, and no one set can be summarized which shall cover all 

conditions. Surface waters, descending and then diffusing laterally 

leach great areas of rock in the belt of weathering, and so reenforce 

the filling of the veins. Without the concurrence of waters from all 

directions and for long periods of time, the development of large 

ore bodies would be most difficult to explain. Suppose, now, that 

by a complex of processes, such as have been described, segregative, 

solvent, pneumatolytic, and precipitative, a channel has become 

filled with mineral matter and transformed into a vein. Suppose, 

also, that the vein is at first a mixture of quartz and iron pyrites, 

containing in moderate proportions admixtures of chalcopyrite, 

galena, and zinc blende, with minute but perceptible traces of silver 

and gold. The vein rises from the zone Of anamorphism, through 

the belt of cementation, into the belt of weathering, where a third 

group of transformations, a new redistribution of material, occurs. 

These changes can be followed without much difficulty, and their 

character is partly known. 1

In the first place, the surface, waters, charged with oxygen and 

carbonic acid, attack the outcrop of ores, oxidizing them more or ^ 

less completely to sulphates. Sulphuric acid or acid salts are formed 

at the same time, which assist in the decomposition of the adjacent 

rocks. That decomposition is more than ordinarily extensive in th& \ 

vicinity of metalliferous veins, and the rocks therefore acquire a \ 

higher degree of permeability to the percolating waters.

The sulphates thus formed differ in solubility and are furthermore . 

affected by other substances contained in the waters. Gold is left in 

the free state, in which condition it may partly dissolve in ferric 

solutions, but for the most part remains unchanged. Silver is converted into chloride, for chlorine is rarely absent in such alterative 

processes, and that compound dissolves with some difficulty. Part '' 

of the silver, if much silver is present, may be reduced'to the metallic 

form and remain as native silver near the surface. The iron salts, 

which are ferrous at first, are soon oxidized to the ferric state, form- * 

ing basic compounds and passing finally into hydroxide or limonite. 

Some iron is dissolved and carried away; in certain cases this is done 

completely, but generally a mass of limonite is left upon the surface, 

the gossan or iron cap of mining terminology. At the surface, then, 

there is a concentration of iron, in which a large part of the gold and 

possibly some silver is retained. The other metals have been washed 

away, mor.e or less perfectly, and carried down to lower levels.

> For a summary of these alterations, see R. A. F. Penrose, Jour. Geology, vol. 2,1894, p. 288; also De 

Launay's memoir, previously cited. An interesting paper by Penrose on the causes of ore shoots is in 

Econ. Geology, vol. 5,1910, p. 97. On ore deposition by meteoric waters, see A. C. Lawson, Bull. Univ. y 

California, Dept. Geology, vol. 8,1914, p. 219.
METALLIC ORES. 643,

The sulphates of copper and zinc are very soluble; that of lead 

much less so. If the descending waters contain much silica, silicates 

like chrysocolla and calamine are likely to be formed. If carbonates 

are abundant in the solutions, malachite, azurite, smithsonite, and 

cerusite will appear. Oxides of lead and copper may also be produced, and any or all of these substances are to be found in the oxidized zone of an ore body. Below this zone the sulphate solutions 

meet the unaltered sulphides, and a secondary enrichment of them 

becomes possible. 1 The dominant sulphide, pyrite, reacts upon solutions of .copper and zinc sulphates, precipitating both metals as sulphides and passing into solution as sulphate of iron. This reaction 

is well known and was established experimentally. Thus at the 

upper portion of the unoxidized ores there is a concentration of copper, 

and perhaps of zinc, below which the original leaner ore continues to

its limit, whatever that point may be. In this way some " bonanzas " 

originate. A separation of the metals is effected at or near the surface, 

and the more soluble ones are concentrated by reprecipitation below. 

Although the broad general conception of secondary enrichment 

is simple enough, its detailed application to specific cases is not always 

easy. Complex solutions are acting upon complex mixtures of 

minerals, and the reactions which take place are very diverse. The 

sulphides differ in solubility; they form with different degrees of 

facility; and the conditions of their precipitation vary with conditions 

of concentration and temperature. There are, however, several 

researches on record, which help to show what may happen within an 

established ore body. As long ago as 1837, E. F. Anthon 2 studied 

the precipitation of soluble metallic salts by insoluble sulphides, and 

a similar, but much more elaborate series of experiments was carried 

out much later by E. Schurmann.3 In each investigation a series 

was established in which the sulphide of any one of the metals in it 

would be thrown down at the expense of any sulphide lower in the 

series. The series found by Schurmann was as follows: Palladium, 

mercury, silver, copper, bismuth, cadmium, antimony, tin, lead, 

zinc, nickel, cobalt, ferrous iron, arsenic, thallium, and manganese. 

For example, if a solution of copper were long in contact with the

1 On secondary enrichment, see W. II. Weed, Bull. Gcol. Soc. America, vol. 11,1899, p. 179; S. IF. Evaraons, Trans. Am. Inst. Min. Eng., vol. 30,1900, p. 177, and Weed, idem, p. 424; J. F. Kemp, Econ. Geology, 

vol. 1,1905, p. 11. On enrichment by ascending waters, see Weed, Trans. Am. Inst. Min. Eng., vol. 33, 

1903, p. 747. On downward enrichment, see F. L. Ransome, Econ. Geology, vol. 5, 1910, p. 205. Discussion by several writers of Ransome's paper appears in the same volume, pp. 387, 477, 678. See also G. J. 

Bancroft, Trans. Am. Inst. Min. Eng., vol. 38, 1908, p. 245, and Bull. Am. Inst. Min. Eng., 1909, p. 581; 

E. S. Bastin, Econ. Geology, vol. 8,1913, p. 51. U.S. Geol. Survey Bull. 529,1913, by W. H. Emmons, is a 

general summary of the subject. So, too, is the paper by C. F. Tolman, Min. and Sci. Press, vol. 106,1913, 

pp. 38,141,178, which closes with a long bibliography. Bull. No. 625 of the U. S. Geological Survey, by 

W. H. Emmons, is an elaborate monograph on the enrichment of ore deposits. Emmons gives a good 

bibliography of the subject on pp.°20-33. For early anticipations of the theory, see G. F. Becker, Trans. 

Am. Inst. Min. Eng., vol. 42,1911, p. 653.

2 Jour, prakt. Chemie, vol. 10,1837, p.'353. . 

8 Liebig's Annalen, vol. 249,1888, p. 326.
644 DATA OF GEOCHEMISTRY. \

s

sulphide of any metal following it in the series, it would decompose the latter with precipitation of copper sulphide. Starting with 

galena, the reaction CuS04 +PbS = CuS+PbS04 has been actually ( 

studied by R. C. Wells,1 in the laboratory of the United States Geological Survey, and the anticipated result was obtained. Wells has 

also investigated the precipitation of sulphides in pah's, and has > 

found that they are thrown down unequally. If to a solution containing iron and copper an alkaline sulphide is added in excess, both 

metals are completely precipitated. But if, in a neutral solution, 

there is a deficiency of the alkaline sulphide, all the copper is 

deposited before any iron is thrown down. Attempts to form double 

sulphides by precipitation were unsuccessful; but double sulphides 

such as chalcopyrite are among the most important ores.

The series of precipitations studied by Schurmann is evidently 

somewhat analogous to the well-known electrochemical series of the 

chemical elements and suggests that the phenomena of secondary 

enrichment may be of an electrical character. The problem of electrical activities in ore bodies was long ago examined by R. W. Fox * 

and has since received attention from a number of other investigators, l- most recently by V. H. Gottschalk and H. A. Buehler 3 and R. C. 

Wells."

Gottschalk and Buehler studied especially the oxidation of sulphides, and found that when two different minerals are immersed in 

the same solution one showed an increase of solubility while the other 

was more or less protected. They also found and measured the \ 

differences in electrical potential among the minerals studied and 

found that when two of them were brought in contact and moistened 

they formed a small battery. Such a contact, in presence of the percolating solutions of the earth's crust, may be an important factor 

in the process of oxidation of natural minerals.

Gottschalk and Buehler in their experiments used as a solvent 

only water. Wells, however, in a similar research measured the 

electrical potential of his minerals in various solutions and found wide 

differences. From this he concludes that the nature of the solvent 

is of fundamental importance and that by electrical activity different 

minerals may be produced, depending upon' the character of the ^ 

solutions. Evidently the application of theory to the discussion of 

any specific geological problem involves variable factors and may be 

exceedingly complex.

1 Econ. Geology, vol. 5,1910, p. 1.

2 Philos. Trans., 1830, pt. 2, p. 399; idem, 1835, pt. 1, p. 39; British Assoc. Adv. Sci. Kept., 1834, p. 572; >U~ 

idem, 1837, p. 133; Philos. Mag., 3d ser., vol. 23,1843, pp. 457, 491. See also W. J. Henwood, Annales des 

Mines, 3d ser., vol. 11, 1837, p. 585; A. von Strombeck, Karsteu's Archiv, vol. 6, 1833, p. 431; F. Reich. 

Poggendorf's Annalen, vol. 48, 1839, p. 287; W. Skey, Trans. New Zealand Inst., vol. 3, 1871, p. 232; C, 

Barus, Mon. U. S. Geol. Survey, vol. 3,1882, pp. 309-367. ,

3 Econ. Geology, vol. 7,1912, p. 15. An earlier paper is in vol. 5, p. 28,1910. 

< Bull. U. S. Geol. Survey No. 548,19145.
/ METALLIC ORES. 645

Analogous to the process by which the sulphides of a vein may be 

enriched, is another process that often operates in the formation of 

quite different ore bodies. This process has already been noted in 

relation to phosphate rock, and it consists in the precipitation of 

dissolved substances by limestone. A metalliferous solution, containing any of the heavy metals, percolates through limestone, and 

double decomposition takes place. The heavy metals, zinc, copper, 

iron, manganese, etc., are precipitated, and calcium goes into solution. 

Reactions of this kind have been experimentally studied by several 

investigators.1 The diffused metals, or rather their compounds, may 

be concentrated by solution and consequent removal of the remaining carbonate of lime. In this connection R. C. Wells 2 has investigated the relative solubilities of the metallic carbonates, much as 

was done by Schiirmann in the series of sulphides. The order found, 

beginning with the least soluble, was mercury, lead, copper, cadmium, zinc, iron, nickel, manganese, silver, calcium, magnesium. 

Each of these carbonates, under equal conditions, would precipitate 

those preceding it from aqueous solution. Wells, however, is careful 

to point out that the application of this series to specific cases involves 

consideration of mass effects which may change the order of precipitation.

In the foregoing discussion only ordinary solutions have been considered, but colloidal solutions must also be taken into account. 

j J. D. Clark and P. L. Menaul 3 have treated this phase of ore deposition experimentally and have shown that nearly all important metallic sulphides, arsenides, and sulpbo-salts may be dispersed as colloids under the influence of hydrogen sulphide in feebly alkaline 

solutions. The minerals are then in condition to migrate with the 

'solutions, and when the hydrogen sulphide escapes they are precipitated. Furthermore, when these solutions come into contact with 

calcareous or argillaceous material precipitation also occurs, and in 

the case of limestone, just as with ordinary solutions, replacement 

is effected.

The formation of ore bodies by magmatic segregation has already 

been mentioned and is merely a phase of magmatic differentiation, 

which was discussed in Chapter IX, ante. The titaniferous magnetites and some pyrrhotites form ore bodies of this kind, in which the 

heavy minerals have separated from the molten magma just as matte 

separates from slag. On this subject there is an elaborate memoir

'Seefor example, B. Irvine and W. S. Andersoii, Proc. Boy. Soc. Edinburgh, vol. 18, 1890, p. 52; \V. 

Meigen, Ber. Naturforsch. Gcsell. Freiburg, vol. 13,1903, p. 40; vol. 15,1905, p. 38; and inaugural dissertations, Freiburg, 1906, by L. Gassner and C. Mahler.

»Bull. U. S. Geol. Survey No. 609.

3 Econ. Geology, vol. 11,1916, p. 37. See also C. F. Tolman and J. D. Clark, idem, vol. 9, 1914, p. 559; 

and Clark, Univ. of New Mexico, No. 75,1914.
646 DATA OF GEOCHEMISTRY. \

v,

by W. H. Goodchild, 1 who has studied the process from various points 

of view, and has taken into account the influence of gaseous factors. 

To this paper other reference will be made later.

In this bare outline of what may be supposed to happen in the 

formation of a metalliferous deposit, details have been purposely 

left out of account. Their consideration naturally follows in the t 

succeeding pages, in which the metals are studied separately.2

GOLD. 3 (

Although gold is one of the scarcer elements, it is widely diffused 

in nature. It is found.in igneous rocks, sometimes in visible particles; 

it accumulates in certain detrital or placer deposits; it also occurs in 

sedimentary and metamorphic formations, in quartz veins, and in 

sea water.4 A notable amount of gold is now recovered from copper 

ores, during the electrolytic refining of the copper. A. Liversidge 5 

found traces of gold in rock salt from several localities, in quantities 

of about 1 to 2 grains per ton. F. Laur,8 in Triassic rocks taken from 

deep borings in the department of Meurthe-et-Moselle, France, found 

both gold and silver. The maximum amount in a sandy limestone, 

was 39 grams of gold and 245 of silver per metric ton, but most of the 

assays ran much lower.

Gold has been repeatedly observed as a primary mineral in igneous 

or plutonic rocks. G. P. Merrill 7 reports it in a Mexican granite, 

embedded in quartz and feldspar. W. Moricke 8 found visible gold \ 

in a pitchstone from Chile; and 0. Schiebe 9 discoveredrit in an \ 

olivine rock from Damara Land, South Africa. -

In a series of assays of rocks collected at points remote from .known 

deposits of heavy metals, L. Wagoner 10 found the following quantities, in milligrams per metric ton, of gold and silver. The samples ^ 

are Californian, except when otherwise stated.

1 Mining Mag., vol. 18,1918, pp. 20, 75,131,186, 240, 296; and vol. 19,1918, pp. 21, 78,135,188. See also a 

paper by J. T. Singewald, jr., in Min. and Sci. Press, vol. 114,1917, p. 733. Other memoirs on the subject 

will be considered under the headings of the individual metals, especially in reference to nickel.

2 The work of Sullivan on the precipitation of copper by shale, feldspar, etc., is noted later in the section 

of this chapter upon the ores of that metal. The ores of iron, manganese, and aluminum have been sufficiently described in the chapters upon rock-forming minerals, rock decomposition, and the sedimentary 

rocks.

8 For a list of the Survey publications on gold and silver see Bull. 470,1911.

4 See ante, p. 120.

 Jour. Chem. Soc., vol. 71,1897, p. 298.

«Compt. Rend., vol. 142,1906, p. 1409. Also in Compt. rend. Soc. iud. inine'rale, Sept.-Oct., 1906. :

7 Am. Joun Sci., 4th ser., vol. 1,1896, p. 309. Compare W. P. Blake, Trans. Am. Inst. Min. Eng., vol. 26, 

1896, p. 290.

s Min. pet. Mitt., vol. 12,1891, p. 195

"Zeitschr. Deutsch. geol. Gesell.,vol. 40, 1888, p. 611. For other examples see Stelzuer-Bergeat, Die \ 

Erzlagersfatten, pp. 69-70. See also J. Catharinet, Eng. and Min. Jour., vol. 79,1905, p. 127, on gold in the 

pegmatite of Copper Mountain, British Columbia. K. W. Brock (idem, vol. 77,1904, p. 511) reports gold 

in British Columbia porphyries. On primary gold in a Colorado granite, see J. B. Hastings, Trans. Am. 

Inst. -Mill. Eng., vol. 39,1909, p. 97. An association of gold with sillimanite is reported by T. L. Watson. 

Am. Jour. Sci., 3d ser., vol. 33,1912, p. 241. A. Lacroix found disseminated gold in a biotite gneiss from 

Madagascar; see Compt. Rend., vol. 132,1901, p. 180..

10 Trans. Am. Inst. Min. Eng., vol. 31,1901, p. 808.
METALLIC ORES.

Gold and silver in rods from California, Nevada, etc.

' [Milligrams per metric ton.]

647

Granite. ....................................................

Do....................................................

Do....................................................

Do....................................................

Do....................................................

Basalt. .....................................................

Marble. .....................................................

Marble, Carrara. .............................................

Au.

104

137

115

720

1,130

39

24

21

26

76

5

8.63

Ag.

7,660

1,220

940

15, 430

5,590

540

450

320

547

7,440

212

201

In a later investigation Wagoner 1 determined gold and silver in 

deep sea (Atlantic Ocean) dredgings. In six samples assayed the 

gold ranged from 15 to 267 milligrams per metric ton, and the silver 

from 304 to 1,963 milligrams.

These figures suggest a very general distribution of gold in rocks 

of all kinds. J. R. Don,2 however, in an extended investigation of 

the Australian gold fields, found that the deep-seated rocks contained 

gold only in association with pyrite. When pyrite was absent, 

gold was absent also. The country rocks of the vadose region, on 

the other hand, were generally impregnated with gold, even at a 

distance from the auriferous reefs, and Don supposes that the metal 

was probably transported in solution. This point will be discussed 

later.

Gold occurs principally in the free state or alloyed with other 

metals, such as silver, copper, mercury, palladium, rhodium, bismuth, and tellurium. Leaving detrital or placer gold out of account, 

its chief mineral associates are quartz and pyrite. Its connection 

with pyrite is so intimate that some writers have argued in favor of 

its existence as gold sulphide, 3 but the evidence in favor of that 

belief is very inadequate. No unmistakable gold sulphide has yet 

been found as a definite mineral species, nor is it likely to form 

except in an environment entirely free from reducing agents. The 

compounds of gold are exceedingly unstable, and the metal separates 

from them with the greatest ease.

> Trans. Am. Inst. Min Eng., vol. 38,1907, p. 704

2 Idem, vol. 27, 1897, p. 564. A. R. Andrew (Trans. Inst. Min. Met., vol. 19,1910, p. 276) questions the 

trustworthiness of many such assays of country rock. He thinks that gold as an impurity in litharge 

accounts for most of the reported findings.

8 See, for example, T. W. T. Atherton, Eng. and Min. Jour., vol. 52,1891, p. 698, and A. Williams, idem, 

vol. 53, 1892, p. 451. Williams cites an auriferous pyrite from Colorado which yielded no gold on amalgamation, but from which gold was extracted by solution in ammonium sulphide. Gold sulphide is 

soluble in that reagent. Hence the inference that it may have been present in the ore. See also a paper 

by W. Skey, Trans. New Zealand Inst., vol. 3, 1870, p. 216.
648 DATA OF GEOCHEMISTRY.

\

On the petrologic side gold is most commonly associated with 

rocks of the persilicic type, such as granite and its metamorphic 

derivatives. I refer now to its primary occurrences. It is not rare 

in association with dioritic rocks, but in rocks of subsilicic character 

it is exceedingly uncommon. Its very general presence in,quartz 

veins is testimony in the same .direction and suggests the probability 

that gold is more soluble in silicic magmas than in those richer in 

bases. The auriferous quartz veins were probably formed in most 

instances from solutions,% but J. E. Spurr 1 has argued that in some 

cases they are true magmatic segregations. This view was developed 

by Spurr in his studies of gold-bearing quartz from Alaska and 

Nevada, but it has been questioned, by C. R. Van Hise 2 and others.

The composition of native gold is variable. The purest yet found, 

from Mount Morgan, Queensland, according to A. Leibius,3 assayed 

as high as 99.8 per cent, the remainder being mainly copper, with a 

trace of iron. Gold commonly ranges from 88 to 95 per cent, with" 

more or less alloy of the metals already mentioned. The following 

analyses well represent the character of the variations:

Analyses of native gold.

A. Gold from Persia. Analyzed by C. Catlettin the laboratory of the United States Geological Survey.

B. Electrum, Montgomery County, Virginia. Analysis by S. Porcher, Chem. News, vol. 44, 1881, p. 

189.

C, D, E. Gold associated with native platinum, Colombia. Analysis by W. H. Seamon, Chem. News, 

vol. 46,1882, p. 216.

F. Amalgam, Mariposa County, California. Analysis by F. L. Sonnenschein, Zeitschr. Deutsch. jieol. \ 

Gesell., vol. 6,1854, p. 243. Specific gravity, 15.47. Near AuHgs. . v

G. Palladium gold. Taguaril, Brazil. Analysis by Seamon, Chem. News, vol. 46, 1882, p. 216. Kee 

Wilm, Zeitschr. anorg. Chemie, vol. 4,1893, p. 300, on palladium gold from the Caucasus. Also E. Hussak, 

Zeitschr. prakt. Geologic, 1906, p. 284, on palladium gold in Brazil.

H. Maldonite, or "black gold," Maldon, Victoria. Analysis by R. W. E. Maclvor, Chem. News, vol. 

55,1887, p. 191. An alloy near Au2Bi.

Au........... -..-...

Ag........ ..........

fn

Hg........... .......

Pd.. ..........

BL... ...............

Fe.......... .........

A

93.24

6.65

"NT r^iip

.11

100. 00

B

65.31

34.01

.14

.20

.34

100. 00

c

84.38

13.26

1.85

99.49

B

80.12

2.27

15.84

98.23

E

84. 01

7.66

7.06

98.73

F

39.02

60.98

100. 00

G

91.06

Trace.

8.21

99.27

H

65. 12 

34.88

100. 00 fr

1 See papers in Trans. Am. Inst. Mm. Eng., vol. 33,1903, p. 288; vol. 36,1906, p. 372. Also Econ. Geology, 

vol. 1,1906, p. 369.

2 A treatise on rnetarnorphism: Mon. U. S. Geol. Survey, vol. 47, 1904, pp. 1048-1049. ;Jee also J. B. 

Hastings, Trans. Am. Inst. Min. Eng., vol. 36, 1906, p. 647. -Hastings regards the Silver Peak ores as 

deposited by ascending waters along lines of fracturing.

s Proc. Roy. Soc. New South Wales, vol. IS, 1884, p. 37.
METALLIC ORES. 649

The tellurides l containing gold are also variable in composition, 

partly because most of them contain silver, and often other metals, 

which may be only impurities. Kalgoorlite and coolgardite, for example, which are tellurides of gold, silver, and mercury, are mixtures 

of the mercury compound, coloradoite, with other species.2 Calaverite 

and krennerite approximate to gold telluride alone. Sylvanite, petzite, muthmannite, and goldschmidtite are tellurides of gold and 

silver. The following analyses are sufficient to indicate the composition of the more important of these minerals:

Analyses of tellurides containing gold.

A. Calaverite, (AuAg)Te2 , Cripple Creek, Colorado. Analysis by W. F. Hillcbrand.

B. Krennerite, (AuAg)Te2) Nagyag, Hungary. Analysis by L. Sipo'cz, Zeitschr. Kryst. Min., vol. 11, 

1886, p. 210.

C. Sylvanite, (AuAg)Te2 , Grand View miue, Boulder County, Colorado. Analysis by F. W. Clarke, 

Am. Jour. Sci., 3d ser., vol. 14,1877, p. 286.

D. Potzite, (AuAg)Te2 , Norwegian mine, Calaveras County, California. Analysis by Hillebrand.

A.U.. ..........................................

Ae oS::::::::::::::::::::::::::::::::::::::::::::

Fe...........................................

Te.. .........................................

Se................. ............................

Mo............................................

Sb...........................................

FegOg.. .......................................

Insoluble. .....................................

A

38.95

3.21

57.27

.12

.33

99. 88.

:u

34.77

5.87

.34

.59

58. 60

.65

100. 82

.0

29.35

11. 74

58. 91

100. 00

:o

25. 16

41. 87

33. 21

Tvar»A

.08

100. 32

There has been much discussion over the tellurides of gold. B. 

Brauner 3 asserts that crystalline "polytellurides" can be formed, 

which dissociate upon heating, leaving the compound Au2Te as an 

end product. Theoretically, the telluride Au2Te3 should also be 

capable of existence. According to V. Lenher,4 the tellurides of gold 

are probably not definite compounds, but more in the nature of alloys. 

Attempts at the synthesis of a distinct compound failed. T. K. 

Rose,5 however, who studied the alloys of gold and tellurium, obtained 

a definite compound, AuTe2 , identical with the natural calaverite. 

The same result was also obtained by G. Pellini and E. Quercigh.6 

W. J. Sharwood 7 has pointed out the very general association of 

bismuth with tellurium gold ores.

1 For a general review of the tellurides, with references to literature, see J. F. Kemp, Min. Industry, 

vol. 6,1898, p. 295.

2 L. J. Spencer, Mineralog. Mag., vol. 13, p. 268, 1903. Spencer gives a good bibliography of the Australian tollurides.

B Jour. Chem. Soc., vol. 55,1889, p. 391.

< Jour. Am. Chem. Soc., vol. 24,1902,p. 358. See also E. 'D. Hall and V. Lenher, idem.p. 919. 

6 Trims. Inst. Min. Met., vol. 17,1908, p. 285.

6 Rend. E. accad. Lincei, 5th ser., vol. 19,1910, p. 445.

7 Econ. Geology, vol. 6,1911, p. 22.
650 ' ' DATA OF GEOCHEMISTRY. \

V

Although gold is primarily a magmatic mineral, it is also transported in and deposited from solutions. Many occurrences of gold 

indicate this fact very plainly. 0. Dieffenbach,1 for instance, mentions gold incrusting siderite at Eisenberg, near Corbach, in Germany. O. A. Derby 2 reports films of gold on limonite, from Brazil. 

A. Liversidge 3 found it hi recent pyrite, which formed on twigs in , 

a hot spring near Lake Taupo, New Zealand. J. C. Newbery 4 mentions gold in a manganiferous iron ore coating quartz pebbles, the 

quartz itself being free from gold. In the suiter of Steamboat ^ 

Springs, Nevada, G. F. Becker 5 found both gold and silver; 3,403 

grams of suiter gave 0.0034 of gold and 0.0012 of silver. Gold is 

also reported by J. M. Maclaren 8 in the siliceous suiter of the hot 

springs at Whakarewarewa, New Zealand. R. Brauns 7 has described 

gold as a cement joining fragments of quartz. The specimen of 

cinnabar from a fissure in Colusa County, California, mentioned by 

J. A. Phillips,8 which was covered by a later deposit of gold, is also 

suggestive. According to R. W. Stone,9 the coal of Cambria, Wyoming, contains appreciable quantities of gold. All of these occurrences are best interpreted on the assumption that the gold was 

precipitated from solution; and, indeed, they can hardly be explained 

otherwise. The fact that gold actually exists in natural solutions 

has already been shown hi regard to sea water and certain mine 

waters, and J. B. Harrison 10 has detected it in the water of Omai 

Creek, British Guiana. He has also found gold in the ash of ironwood; in confirmation of an earlier observation by E. E. Lungwitz. \ 

The occurrence of gold as a volcanic emanation has also been reported 

by W. H, Goodchild. 11 The crater of the volcano La Sufral, in Colombia, is periodically filled by jets of steam from which sulphur is 

deposited; and that sulphur contains an easily determinable proportion of gold. This mode of occurrence seems so far to be unique.

The natural solvents of gold appear to be numerous that is, if 

the recorded experiments are all trustworthy. G. Bischof 12 found 

that gold was. held in solution by potassium silicate, and Liversidge 13 

was able to dissolve the metal by digesting it with either potassium 

or sodium silicate under a pressure of 90 pounds to the square inch.

 Neues Jahrb., 1854, p. 324. 

2 Am. Jour. Sci., 3d ser., vol. 28,1884, p. 440.

8 Jour. Roy. Soc. New South Wales, vol. 11,1877, p. 262. - t 

«Trans. Roy. Soc. Victoria, vol. 9,1868, p. 52. 

i* Mon. U. S. Geol. Survey, vol. 13,1888, p. 344. 

« Geol. Mag., 1906, p. 511.

' Chemische Mineralogie, 1896, p. 406. . 

s Quart. Jour. Geol. Soc., vol. 35,1879, p. 390. On the natural associations of gold, see F. C. Lincoln, 

Econ. Geology, vol. 6,1911, p. 247.

« Bull. U. S. Survey No. 499,1912, p. 63.

* Geology of the gold fields of British Guiana, 1908, p. 209.

11 Mining Mag., vol. 19,1918,p. 191.

12 Lehrbuch der chemischen und physikalischen Geologic, 2d ed., vol. 3, p. 843. 

» Proc. Roy. Soc. New South Wales, vol. 27,1893, p. 303.
/ METALLIC ORES. 651

C. Doelter * claims that gold is perceptibly soluble in a 10 per cent 

sodium-carbonate solution, and also in a mixture of sodium silicate 

and bicarbonate. Solutions of alkaline sulphides have been found by 

several authorities, notably by W. Skey',2 T. Egleston, 3 G. F. Becker, 4 

and A. Liversidge, 5 to be effective solvents of gold; and Skey reports

, that even hydrogen sulphide attacks the metal perceptibly. All of 

these solvents occur in natural waters.

Solutions of ferric salts are also capable, under proper conditions,

-; of dissolving gold. According to- H. Wurtz, 6 ferric sulphate and 

ferric chloride are both effective. P. C. Mcllhiney,7 found that the 

chloride acted on the metal only in presence of oxygen, which serves 

to render the ferric salt an efficient carrier of chlorine. Some experiments by H. N. Stokes 8 in the laboratory of the United States Geological Survey, showed that ferric chloride and also cupric chloride 

dissolve gold easily at 200°. The reactions are reversible, and gold 

is redeposited on cooling. Ferric sulphate, according to Stokes, does 

not dissolve gold unless chlorides are also present. Perhaps the 

pseudomorph of gold after botryogen, a basic sulphate of iron, 

described by W. D. Campbell, 9 may have originated from some solution in ferric salts.

F. P. Dewey 10 has found that finely divided gold is perceptibly

soluble in nitric acid, but that observation has little bearing upon

its natural solution. W. J. McCaughey u has reported its solubility

, in hydrochloric acid solutions of iron alum and cupric chloride.

,' With rising temperature the solubility increases rapidly. N. Awer-

"' kiew 12 finds that gold is also dissolved by hydrochloric acid in presence of organic matter.

The usual laboratory solvent for gold, aqua regia, owes its efficienc}7 

to the liberation of free chlorine. T. Egleston " asserts that traces of 

nitrates with chlorides in natural waters can slowly dissolve the 

metal. J. K. Don 1 * found that weak hydrochloric acid, 1 part in 

3,250 of water, in presence of manganese dioxide, would take gold 

into solution. R. Pearce, 15 heated gold and a solution containing 40

, i Man. pet. Mitt., vol. 11,1890, p. 328.

2 Trans. New Zealand Inst., vol. 3,1870, p. 216; vol. 5, 1872, p. 382.

3 Trans. Am. Inst. Min. Eng., vol. 9,1880-81, p. 639.

4 Am. Jour. Sci., 3d ser., vol. 33,1887, p. 207.

6 Proc. Boy. Soc. New South Wales, vol. 27,1893, p. 303. 

< «Am. Jour. Sci., 2d ser., vol. 26,1858, p. 51.

7 Idem, 4th ser., vol. 2,1896, p. 293.

8 Econ. Geology, vol. 1,1906, p. 650.

8 Trans. New Zealand Inst., vol. 14, 1881, p. 457. Campbell's observations need to he verified. The 

specimen was found in the Thames gold field, New Zealand.

10 Jour. Am. Chein. Soc., vol. 32,1910, p. 318.

11 Idem, vol. 31, 1909, p. 1261. .

12 Zeitschr. anorg. Chemie, vol. 61,1909, p. 1..

is Trans. Am. Inst. Min. Eng., vol. 8,1879-80, p. 454.

n Idem, vol. 27, 1897, p. 564. According to Don, ferric salts are not effective solvents for gold.

15 Idem, vol. 22,1893, p. 739.
652 DATA OF GEOCHEMISTRY. \

grains of common salt to the gallon, with a few drops of sulphuric 

acid and some manganese dioxide, and obtained partial solution. 

T. A. Rickard 1 treated a rich Cripple Creek ore, which contained \ 

manganic oxides, with a solution of ferric sulphate, sodium chloride, 

and a little sulphuric acid, and practically all. of the gold dissolved. 

On immersing in this solution a fragment of black, carbonaceous v 

shale, the gold was reprecipitated. How far solutions of this kind can 

be produced in nature is uncertain; but the extreme dilution of the 

solvents may be offset by their prolonged action. The laboratory 

processes all tend to accelerate the reactions. V. Lenher's observation, 2 that strong sulphuric acid, in presence of oxidizing agents, such 

as the dioxides of manganese and lead, dissolves gold, is probably 

not applicable to the discussion of natural phenomena. W. H. 

Emmons,3 however, from a study of the experiments already cited, 

and also of the association of manganese oxides with gold in nature, 

has shown that the manganese plays an important part in the formation of auriferous deposits. Its effect is due to its interaction with 

acid solutions of chlorides, with which it generates chlorine; chlorine 

being the actual solvent of gold. In the presence of alkaline solutions, 

or of calcite, free chlorine can not appear, and the manganese oxides 

become inoperative.4 Calcite, however, and also magnesite have_been 

shown by V. Lenher 5 to be effective precipitants of gold.

The experiment by Rickard just cited, is especially suggestive as 

illustrating the ease with which gold is redeposited from its solutions. N 

So far is gold is concerned, the reducing agents are numberless, and x . many of them occur in nature. Organic matter of almost any kind 

will precipitate gold, and such matter is rarely, if ever, absent from 

the"soil. Gold, therefore, although it may enter into solution, is not 

likely to be carried very far. On mere contact with ordinary soils it 

would be at once precipitated.6

Gold is also thrown out of solution by ferrous salts, by other metals, 

and by many sulphides, especially by pyrite and galena.7 According - 

to Skey one part of pyrite will precipitate over eight parts of gold. 

The sulphides of copper, zinc, tin, molybdenum, mercury, silver, bismuth, antimony, and arsenic, and several arsenides, all act in the x

'Trans. Am. lust. Min. Eng., vol. 26,1896,p. 978.

a Jour. Am. Chem. Soc., vol. 26,1904, p. 550.

3 Bull. Am. Inst. Min. Eng., 1910, p. 767, and Jour. Geology, vol. 19,1911, p. 15. See also A. D. Brokaw, ^ 

Jour. Geology, vol. 18,1910, lOp. 32,1.

« See F. T. Eddingfleld, Philippine Jour. Sci., vol. 8A, 1913, p. 125; Econ. Geology, vol. 8, 1913, p. 498.

s Econ. Geology, vol. 13,1908, p. 161. See also H. H. Morris, Jour. Am. Chem. Soc., vol. 40, 1918, p. 917.

6 On the relations of vegetation to the deposition of gold see E. E. Lungwitz, Zeitschr. prakt. Geologic, 

1900, pp. 71, 213.

i See C. Wilkinson, Trans. Roy. Soc. Victoria, vol. 8, 1866, p. 11; W. Skey, Trans. New Zealand Inst., 

vol. 3, 1870, p. 225; vol. 5, 1872, pp. 370, 382; A. Livcrsidge, Proc. Roy. Soc. New South Wales, vol. 27, 

1893, p. 303; C. Palmer and E. S. Bastin, Econ. Geology, vol. 8, 1913, p. 140; F. F. Grout, idem, p. 407;- 

A. D. Brokaw, Econ. Geology, vol. 21, 1913, p. 251.
/ METALLIC ORES. 653

same way. So, too, does tellurium, according to V. Lenher,1 and also 

the so-called tellurides of gold. If the latter were definite compounds, they could hardly behave as precipitants for one of their 

constituent elements.

SILVER.2

f

Silver, like gold, is widely diffused in nature. Its presence in 

igneous rocks, together with gold, has been shown in the preceding

/ pages, and its existence in sea water was noted in an earlier chapter. 

A. Liversidge 3 found it in rock salt, seaweed, and oyster shells, while 

W. N. Hartley and H. Ramage 4 discovered spectroscopic traces of 

silver in a large number of minerals. Out of 92 iron ores of all 

classes only four were free from silver, and it was generally detected 

in manganese ores and bauxite. Blende, galena, and the pyritic ores 

almost invariably contain it. Argentiferous galena, silver-lead ore, 

is one of the chief sources of this metal.

Unlike gold, silver occurs not only native, but in compounds. 

The sulphides, sulphosalts, and halogen compounds are best known; 

but selenides, tellurides, arsenides, antimonides, and bismuthides also 

exist. These minerals or groups of minerals are best considered

; separately.

Native silver, like native gold, is rarely if ever pure. It commonly

contains admixtures of gold, copper, and other metals in extremely

variable proportions. Silver amalgam, for instance, ranges from 27.5

J to 95.8 per cent of silver, with from. 72.5 to 3.6 per cent of mercury.

' In the Lake Superior copper mines silver is often embedded in native 

copper, each metal being nearly pure. Specimens showing this 

association are locally known as "half-breeds."

In most cases native silver is a secondary mineral. It is often 

found in gossan, and R. Beck 5 mentions films of silver upon the 

scales of fossil fishes from the Mansfield copper shales. According

». to J. H. Lk Vogt 8 the native silver of Kongsberg is largely formed by 

reduction from argentite, although a derivation from proustite may 

also be observed. The silver thus formed is commonly filiform.7 In

' a subordinate degree crystallized silver appears as a primary deposit 

from solutions. Vogt regards a solution of silver carbonate or bicarbonate as the source of the metal, probably because of its association

1 Jour. Am. Chem. Spc., vol. 24,1907, p. 355. Sec also E. D. Hall and V. Lenher, idem, p. 919. Later 

papers by Lenher are in Econ. Geology, vol. 7,1912, p. 744; vol. 9,1914, p. 523. On the relations of colloidal 

gold to ore deposition, see Bastin, Jour. Washington Acad. Sci., vol. 5, p. 64,1915.

2 For a list of the Survey publications on gold and silver see Bull. U. S. Geol. Survey No. 470,1911.

8 Jour. Chein. Soc., vol. 71,1897, p. 298.

4 Idem, vol. 71,1897, p. 533.

8 Ore deposits, Weed's translation, p. 371. According to J. E. Spurr, cited by Einmons in Bull. U. S. 

Geol. Survey, No. 625, p. 271, silver replaces organic remains in the mines of Aspen, Colorado.

6 Zeitschr. prakt. Geologic, 1899, pp. 113, 177.

' 7 On the formation of "hair silver" se'e V. Kohlschuttcr and E. Eydmann, Liobig's Annalen, vol. 390, 

1912, p. 340.
654 DATA OF GEOCHEMISTRY. , \

with calcite, and thinks that ferrous compounds or carbonaceous substances are the precipitants.

The reduction of silver and its complete precipitation in the metallic state by organic matter was long ago observed by H. de Senarmont.1 T. A. Rickard 2 also found that it was thrown down as a 

metallic coating upon a black, carbonaceous shale. The reduction of 

the sulphide by hydrogen is also possible, but less likely to occur 

under natural conditions.3 Any reaction, however, which generated 

nascent hydrogen in contact with silver solutions would precipitate 'v 

the metal.

The nature of the silver solutions in metalliferous veins is not positively known. Apart from Vogt's suppositions, it seems probable that 

silver sulphate may be formed by oxidation of the sulphide. That 

salt, however, would almost certainly be transformed into chloride 

by the chlorides present in percolating waters. Silver chloride, 

although soluble with difficulty, is not absolutely insoluble, and very 

dilute solutions of it may well take part in the filling of veins. It 

has long been known, also, that silver is dissolved by hot solutions 

of ferric sulphate, a reaction which has been studied by H. N. Stokes 4 

in the laboratory of the 'United States Geological Survey. The reac- , 

tion, 2Ag+Fe2 (S04 ) 3 = Ag2S04 + 2FeS04 , is reversible, and crystal- ^ 

lized silver is redeposited on cooling. Stokes also found that a 

solution of copper sulphate, at 200°, was an effective solvent of silver, 

this reaction, like the other, being reversible. Pseudomorphs of , 

cerargyrite, ruby silver, argentite, and stephanite after native silver \ 

are mentioned by Dana.5

The .natural arsenides, antimonides, and bismuthides of silver are 

imperfectly known. An arsenide, Ag3As, was described by H. Wurtz,6 

under the name huntilite. Wurtz also reported an antimouide, animikite, Ag9Sb. Both minerals were found in the Silver Islet mine, 

Lake Superior. The commoner antimonide, dyscrasite, varies from 

Ag3Sb to Ag6Sb.7 The bismuthide, chilenite, is perhaps Ag6Bi. -<

Silver sulphide, Ag2S, is found in nature in two forms the isometric argentite, which is a common ore, and the rare orthorhombic 

acanthite. It is one of the easiest of the silver compounds to prepare, 

and is formed whenever moist hydrogen sulphide 8 comes into coni Annales chim. phys., 3d ser., vol. 32,1851, p. 140.

a Trans. Am. Inst. Min. Eng., vol. 26,1896, p. 978. '

3 See G. Bischof, Lehrbuch der chemischen und physikalischen Geologic, 2d ed., vol. 3, p. 856. Also J. 

Margottet, Compt. Rend., vol. 85,1877, p. 1142.

* Econ. Geology, vol. 1,1906, p. 649. See also the experiments of H.C.Cooke relative to secondary enrichment in Jour. Geology, vol. 21,1913, p.'l. He found that FeSO< is a precipitant of silver. v6 System of mineralogy, 6th ed., p. 20.

6 Eng. and Min. Jour., vol. 27,1879, pp. 55,124.

7 The compound AgsSb appears to be the only definite antimonide of silver, the others are mixed crystals. 

See C. T. Heycock and F. H. Neville,Philos. Trans., vol. 189A, 1897, p. 25; E. Maey, Zeitschr. physikal. 

Chemle, vol. 50,1904, p. 200; G. I. Petrenko, Zeitschr. anorg. Chemie, vol. £0,1906, p. 139, and T. Liebisch, 

Sitzungsb. K. Akad. Wiss. Berlin, 1910, p. 365. Petrenko cites other references.

8 Dry hydrogen sulphide does not attack silver.
METALLIC OBES. . 655

tact with any other silver salt, or with the metal itself. As crystallized argentite it has been prepared in several ways. J. Durocher V 

obtained it by the action of hydrogen sulphide upon silver chloride 

at high temperatures. J. Margottet 2 prepared argentite by passing 

the vapor of sulphur over silver at a low red heat/ With selenium 

or tellurium vapor the corresponding selenide and telluride of silver 

were formed. J. B. Dumas 3 obtained the crystallized sulphide by 

the same process. F. Roessler 4 crystallized argentite and the selenide 

from solution in molten silver, and the selenide also from fused bismuth. C. Geitner,5 by heating silver to 200° with a solution of 

sulphurous acid, obtained argentite. Silver sulphite, heated with 

water to the same temperature, broke down into argentite and crystallized silver. According to E. Weinschenk, 6 argentite is produced 

when silver acetate and a solution of ammonium, sulphocyanate are 

heated together to 180° in a sealed tube. In this case the decomposition of the sulphocyanate yields hydrogen sulphide, which is the 

actually effective reagent. Finally, W. Spring 7 claims to have 

found that silver and sulphur could be forced to combine by repeated 

compression together of the two finely divided elements. The pressure employed was 6,500 atmospheres". Silver and arsenic also unite 

under the same conditions. Spring's experiments, however, or. at 

least his deductions from them, are of doubtful validity. Later 

investigations have failed to confirm them.8

/ Some of these syntheses evidently have no exact parallel in nature. 

Probably the natural reactions are of the simplest kind. Sulphur, 

sulphur dioxide, or hydrogen sulphide acts either upon metallic silver 

or upon any of its naturally available compounds, solid or in solution, and the sulphide is formed. Its crystallization, which is accelerated by the laboratory methods, is presumably a question of time, 

aided by the slight solubility of the compound. The last remark, 

obviously, applies to many other sulphides also. The reduction of 

sulphate solutions by organic matter is another probable mode of 

generation.

It has already been shown that argentite is easily reduced to silver. Indeed, silver sulphide is the most readily reducible, that is, 

the least stable, of all the commoner sulphides. This is illustrated 

by its heat of formation, which is low compared with that of other 

sulphides. The following data, giving heats of formation from solid

1 Compt. Rend., vol. 32,1851, p. 825. 

' Idem, vol. 85,1877, p. 1142.

3 Annales chim. phys., 3d ser., vol. 55,1859, p. 147.

4 Zeitschr. anorg. Chemie, vol. 9,1895, p. 31.

5 Liobig's Annalcn, vol. 129,1804, p. 358. .

 Zoitschr. Kryst. Min., vol. 17,1890, p. 497.

' Ber. Deutsch. chem. Gesell., vol. 16,1883, pp. 324,1002; vol. 17,1884, p. 1218.

a See W. Hallock, Am. Jour. Sci., 3d ser., vol. 34,1887, p. 277; and Bull. U. S. Gcol. Survey No. 64,1890, 

p. 38. Also the general discussion of pressure effects by J. Johnston and L. H. Adams, Am. Jour. Sei. 

4th ser., vol. 35, i913, p. 205.
656 DATA OF GEOCHEMISTRY.

metal and solid sulphur, are furnished by Julius Thomson.1 The 

figures represent small calories.

Heats of formation of various sulphides.

PbS......................................................... 20,430

Cu2S........................................................ 20,270 ' HgS.......................................................... 16,890

Ag2S. -...................................................... 5,340

On the other hand, silver is precipitated from its solutions by 

pyrite, chalcopyrite, galena, and other sulphides.2 H. N. Stokes,3 

in the laboratory of the United States Geological Survey, found that 

marcasite, heated with silver carbonate and potassium bicarbonate 

solution at 180°, precipitated silver sulphide. According to R. 

Schneider,4 bismuth sulphide precipitates silver sulphide from a 

nitrate solution. A. Gibb and R. C. Philip, 5 also working with silver 

nitrate solutions, found that cuprous sulphide precipitated silver sulphide, while copper or cuprous oxide threw down metallic silver.

In a recent investigation by Chase Palmer and E. S. Bastin6 a 

considerable number of sulphides were treated with dilute solutions 

of silver sulphate at ordinary room temperatures. Metallic silver 

was precipitated by chalcocite, niccolite, coVellite(?), bornite, tennantite, alabandite, smaltite, marcasite, pyrrhotite, and chalcopyrite. 

Little or no reaction was observed with cinnabar, stibnite, pyrite, 

galena, millerite, sphalerite, jamesonite, orpiment, and realgar. A 

specimen of niccolite containing much cobaltite gave peculiarly 

suggestive results. The niccolite went completely into solution, 

precipitating an equivalent amount of silver, while the" cobaltite was 

unattacked. The arsenides generally were found to dissolve, while 

the sulpharseriides, like cobaltite and arsenopyrite, failed to react. 

A quantitative method for estimating the relative proportions of 

such minerals in a mixture is therefore now available, apart from the 

significance qf the data in the study of secondary enrichment. In 

certain details the results obtained are apparently inconsistent with 

the statements of previous investigators. This inconsistency is probably due to differences in the experimental conditions. Different 

solutions, whether acid or alkaline, different concentrations and 

temperatures, and impurities in the minerals studied would account 

for much discordance. Pyrite, for example, often contains admixtures of marcasite, the latter being an ^active precipitant of silver,

1 Thermochemische Untersuchungen, vol. 3,1883, p. 455.

»See W. Skey, Trans. New Zealand Inst., vol. 3,1870, p. 225.

» Econ. Geology, vol. 2,1907, p. 16.

' Jour, prakt. Chemie, 2d sen, vol. 41,1890, p. 414.

«Trans. Am. Inst. Min. Eng., vol. 36,1906, p. 667.

« Econ. Geology, vol. 8,1913, p. 140. Also Palmer, idem, vol. 9,1914, p. 664, and vol. 12,1917, p. 207. 00 

the application of these experiments to the study of the silver ore of Cobalt, Ontario, see Bastin, idem, vol. 

12, p. 219.
METALLIC ORES. 657

the former not. Such impure pyrite would evidently give an apparently abnormal reaction. The case of covellite is similarly questionable. The natural mineral contains some admixed chalcocite, which 

precipitates silver quantitatively. Pure cupric sulphide dissolves in 

a solution of silver sulphate, precipitating silver sulphide. It is 

desirable that reactions of this class should be further investigated 

with pure synthetic minerals, and also with solutions of silver chloride. 

The nitrate is not an appropriate solvent to use, for it probably 

does not occur in nature, and it may give rise to confusing secondary reactions. Primary reactions of this character described in 

the preceding paragraphs doubtless assist in the secondary enrichment of ore bodies, the silver being dissolved above and redeposited 

below.

The doubtful behavior of covellite as a precipitant of metallic 

silver is shown by the experiments of Gibb and Philip, which have 

already been cited. More recently E. Posnjak 1 and H. W. Ellery 2 

have also shown that covellite precipitates silver sulphide from solutions of silver, and not the free metal. Furthermore, F. F. Grout 8 

has proved that in the presence of ferric sulphate only silver sulphide 

is thrown down. Grout has especially studied the relations between 

cold acid sulphate solutions and alkaline extracts of metallic sulphides, in which the latter are reprecipitated. Chemically this 

reaction is one which would obviously take place; but Grout suggests 

that such alkaline solutions, ascending from below, may meet descending acid solutions and so cause the formation of ore deposits. These 

observations may fairly be correlated with the experiments by 

Clark and Menaul upon the colloid migration of sulphides, which 

were cited in a previous section of this chapter.4

The selenide of silver, naumannite, Ag2Se, is a well-known but rare 

mineral. A sulphoselenide, aguilarite, Ag4SSe, has also been described. Naumannite often contains lead, due to admixtures of 

the lead selenide.

Hessite is the normal telluride of silver, Ag2Te. Stutzite, Ag^e, is 

a more doubtful substance. The synthesis of hessite by Margottet has 

already been mentioned. B. Brauner 5 also obtained it by the same 

method. R. D. Hall and V. Lenher 6 prepared the compound by 

reducing silver tellurite, and they also found that a telluride was precipitated by the action of tellurium upon silver solutions. Two teli Jour. Am. Chem. Soc., vol. 36,1914, p. 2475.

 »Econ. Geology, vol. 10,1915, p. 580.

 »Idem, vol. 8,1913, p. 417.

*Other recent experiments relative to the solution and precipitation of silver ores are by L. G. Ravicz, 

Econ. Geology, vol. 10,1915, p. 368. That kaolin and orthoclase can precipitate silver from sulphate solutions has been shown by E. C. Sullivan in Bull. U. S. Geol. Survey No. 312,1907. In Bull. 025, pp. 252-263, 

W. H. Emmons has given many other related data.

8 Jour. Chem. Soc., vol. 55,1889, p. 388.

« Jour. Am. Chem. Soc., vol. 24,1902, p. 919.

113750° 19 Bull. 695 -42
658 DATA OF GEOCHEMISTRY.

lurides, AgTe and Ag2Te have been prepared by G. Pellini and 

E. Quercigh. l

Eucairite, CuAgSe; stromeyerite, CuAgS; sternbergite, AgFe2S3 ; 

and frieseite, Ag2Fe5S8J are rare silver-bearing minerals.

The sulphosalts formed by silver with the sulphides of arsenic, antimony, and bismuth are quite numerous.. Some of them are important v 

ores; others are mineralogical rarities; but, on account of their interrelationships, .all are significant. They may be arranged as follows:

Smithite.............. AgAsS2 ........................Monoclinic.

Miargyrite........... .AgSbS2 ........ -................Monoclinic.

Matildite............. AgBiS2 ..........................(?)

Proustite.............Ag3AsS3 ........................Rhombohedral.

Xanthoconite......... Ag3AsS3 ........................Monoclinic.

Pyrargyrite 2 .....'... Ag3SbS3 ....................... Khombohedral.

Pyrostilpnite. ........Ag3SbS3 ....................... .Monoclinic.

Tapalpite 3 ............ Ag3BiTe3 .......................Massive.

Stephanite............ Ag5SbS4 ..... ... >..................Orthorhombic.

Pearceite............. Ag9AsS6 ........................Monoclinic.

Polybasite.............Ag9SbS6 .......................Orthorhombic.

Polyargyrite...........Ag24Sb2S16 .....................Isometric. ',

Schapbachite.......... Ag2PbBi2S5 ...................... Orthorhombic. ,

Brongniardite.........Ag2PbSb2S6 .....................Isometric. (

Andorite............. AgPbSb3S8 .....................Orthorhombic.

Schirmerite.......... .(Ag2 ,Pb)3Bi4S9 . ................Massive.

Diaphorite. ......... .(Ag2 ,Pb)5Sb4Su .................Orthorhombic.

Freieslebenite. ...... .(Ag2,Pb)5Sb4Su .................Monoclinic.

Several other sulphosalts of lead and copper also contain replace- \ 

ments of'silver of considerable importance. Tennantite, CiigAs^, 

contains up to 13.65 per cent of silver; and tetrahedrite, CiigSb-jSy, up 

to 31.3 per cent. In cosalite, Pb2Bi2S5 , as much as 15.66 per cent of 

silver has been found. The tin and germanium sulphosalts, canfieldite, Ag8SnSfl , and argyrodite, Ag8GeS6 , are very rare minerals. Small 

admixtures of any of these compounds with other sulphides, however, would render the latter useful ores of silver. 

Several of these sulphosalts have been prepared synthetically. 

J. Durocher 4 claims to have obtained them by heating mixed chlorides 

of silver and antimony, or silver and arsenic, in a current of hydrogen 

sulphide. Details are not given. H. de Senafmont,5 by heating a 

salt of silver at temperatures ranging from 250° to 350° with a solution of an alkaline sulpharsenite or sulphantimonite in an excess of 

sodium bicarbonate, succeeded in producing pyrargyrite and proustite. . By precipitating a solution of silver nitrate with the potas-

»Atti R. accad. Lincei, vol. 19, pt. 2, 1910, p. 415.

»A mangaruferous sulphantimonide of silver, samsonite, allied to pyrargyrite, has been described by 

Werner and Fraatz, Centralbl. Min., Geol. u. Pal., 1910, p. 331. v 

3 Contains some sulphur partly replacing tellurium. " 

< Compt. Bond., vol. 32, 1851, p. 825. 

* Annales chim. phys.,, 3d ser., vol. 32, 1851, pp. 171-173. 
METALLIC ORES. 659

sium sulphantimonate, K3SbS3 , I. Pouget 1 obtained the amorphous 

compound Ag3SbS3 , equivalent in composition to pyrargyrite. 

C. Doelter 2 prepared miargyrite, pyrargyrite, and stephanite by a 

modification of Senarmont's method. Silver chloride, mixed with a 

sodium carbonate solution of potassium sulphantimonate in varying 

proportions, was heated with hydrogen sulphide in sealed tubes to 

80°-150°. Pyrargyrite was most easily formed; miargyrite appeared 

only once. Doelter 3 also heated silver chloride with antimony 

trichloride, sulphide, or oxide in hydrogen sulphide, and obtained 

similar results. H. Sommerlad 4 prepared pyrargyrite, miargyrite, 

and stephanite by heating antimony sulphide and silver chloride 

together. With arsenic trisulphide, proustite was formed. The 

same species, and also polyargyrite, were produced when the component sulphides were fused together in a stream of hydrogen sulphide. According to R. Schneider,5 potassium bismuth sulphide, 

KBiS2 , added to a solution of silver nitrate, precipitates the compound 

AgBiS2 . This, crystallized by fusion, becomes matildite. Matildite 

was also made by Roessler 6 when the sulphides of silver and bismuth 

were allowed to crystallize together from solution in molten bismuth.

F. M. Jaeger and H. S. van Klooster,7 by prolonging1 heating at 

200°-240° of a mixture of antimony trichloride and silver sulphide in 

a concentrated solution of sodium sulphide and sodium bicarbonate, 

obtained crystalline scales of pyrargyrite. By direct fusion of the 

component sulphides together in an atmosphere of nitrogen they prepared pyrargyrite, miargyrite, proustite and " arsenomiargyrite," the 

last named being probably identical with smithite. From the fusion 

diagrams they infer that some of Sommerlad's results were erroneous.

From these syntheses it is evident that the sulphosalts of silver 

are easily formed, and by various methods. Those which involve 

fusion are probably not operative in nature, for the ores under consideration are commonly associated with gangue minerals which 

could not be formed in that way. Quartz, calcite, fluorite, barite, 

etc., are vein minerals which can be deposited only from solution, 

and the same rule must hold for the accompanying sulphides. Solutions of silver, produced by oxidation of ores, probably react with 

great slowness upon sulphur compounds of arsenic, antimony, or 

bismuth; and the new minerals are produced under varying conditions. The nature of the primary sulphides and of the infiltrating 

solutions, together with conditions of concentration and temperature, 

determines the character of the sulphosalts to be formed. These con-

'Compt. Rend., vol. 124,1897, p. 1518.

1 Allgemeinc oheraischo Mineralogie, 1890, p. 152.

»Zeitschr. Kryst. Min., vol. 11, 1886, p. 29.

* Zoitschr. anorg. Chcmie, vol. 15, 1897, p. 173; vol. 18, 1898, p. 420.

5 Jour, prakt. Cheraic, 2d ser., vol. 41,1890, p. 414.

8 Zeitschr. anorg. Gnomic, vol. 9,1895, p. 31.

' Idem, vol. 78, 1912, p. 245.
660 DATA OF GEOCHEMISTRY.

ditions are imperfectly known, at least quantitatively, and so far as 

the natural phenomena are concerned; but the syntheses give hints 

which may aid in their future discovery. It is also possible that 

arsenical or antimonial solutions may react upon silver compounds, 

such as argentite or the chlorides, and so form sulphosalts of different 

kinds. The supposable reactions are many, and it is not easy to 

determine which ones have operated in any particular case.

The halide ores of silver remain to be mentioned. These are repre1 

sented by three distinct and several intermediate mineral species; 

the three being cerargyrite, or horn silver, AgCl; bromyrite, AgBr, 

and iodyrite, Agl. Embolite is a chlorobromide; iodobromite is represented by the formula 2AgCl.2AgBr.AgI; cu'proiodargyrite is near 

CuAgI2 ; and miersite is an isometric iodide of silver, the commoner 

iodyrite being hexagonal.1

All these minerals are secondary, and appear for the most part 

in the upper levels of ore bodies. Infiltrating solutions of chlorides, 

bromides, or iodides act upon the oxidation products of the primary 

ores, and precipitate these relatively insoluble species. They are not 

absolutely insoluble, however, and probably crystallize very slowly 

from extremely dilute solutions. A form of silver chloride identical 

in appearance with cerargyrite was prepared by F. Kuhlmann 2 when 

a solution of silver nitrate was allowed to mix very gradually with 

aqueous hydrochloric acid. The two solutions were separated by a 

porous layer of asbestos, pumice, or platinum sponge, through which 

they slowly commingled.3 Such a blending of solutions may take 

place in nature, through layers of decomposed rock substance, such 

as a sandy clay or a gossan.

\ COPPER.

The minerals.of copper are much more numerous than those of 

silver, and represent a wider range of composition. No oxidized ores 

of silver are known, but copper is found not only as oxide, but also in 

silicates, sulphates, phosphates, arsenates, carbonates, a basic nitrate, 

and.an oxychloride. The metal is easily oxidizable, and is also easily 

reduced; it therefore occurs both as native copper and in its many 

compounds.

1 See G. T. Prior and L. J. Spencer, Mineralog. Mag., vol. 13, 1902, p. 174, for a general paper on the 

cerargyrite group. .H. B. Kosmann (Leopoldina, vol. 30,1894, pp. 193, 203) has discussed the formation of 

these ores from a thermochemical point of view. . A mineral having the formula 20NaCl-t-AgCl has been 

called huantajayite. Recent papers on the genesis of these ores are by C. R. Keyes, Econ. Geology, vol. 2, 

1907, p. 774; Bull. Am. Inst. Min. Eng., July, 1911, p. 541; J. A. Burgess, idem, vol. 6,1911, p. 13, and vol. 

12,1917, p. 589; and J. W. Young, idem, vol. 13,1918, p. 224. See also A. Knopf, Econ. Geology, vol. 13, 

1918, p. 623.

* Compt. Rend., vol. 42,1856, p. 374.

3 H. Debray also crystallized the chloride, bromide, and iodide of silver from aqueous solutions in mercuric nitrate. Compt. Rend., vol. 70,1870, p. 995. This process can hardly be a reproduction of natural 

conditions. Recent papers on the solubility of silver halide's are by A. G. Melcher, Jour. Am. Chem. Soc., 

vol. 32,1910, p. 50; and W. E. Barlow, idem, vol. 27,1906, p. 1446. For other data see Emmons's citations 

in Bull. U. S. Gool. Survey No. 625,
/ METALLIC ORES. 661

(

Native copper is commonly, if not always, a secondary mineral, 

either deposited from solution or formed by the reduction of some 

solid compound. Pseudomorphs of copper after the oxide, cuprite, 

are well known; and remarkably perfect pseudomorphs after azurite, 

from Grant County, New Mexico, have been described by W. S. 

' Yeates.1 According to W. Lindgren,2 a vein of metallic copper at 

Clifton, Arizona, appears to have been formed from chalcocite. 

Examples of this general character might be multiplied indefinitely.

T. Carnelley 3 has shown that metallic copper is perceptibly attacked and dissolved by distilled water, and much more so by saline 

solutions resembling those existing in nature. The direct solubility 

of the sulphides was considered earlier in this chapter, and also the 

formation of strong sulphate solutions by oxidation of pyrite ores. 

From solutions such as these, but very dilute, the greater deposits of 

native copper appear to have been formed.

In the Lake Superior region the greatest known deposits of metallic 

copper are found.4 Its original home, perhaps as sulphide, was in 

the unaltered igneous rocks, but its concentrations are now found 

in the sandstones, conglomerates, and amygdaloids. In the sandstones and conglomerates it acts as a cement, and it also replaces 

pebbles and even boulders a foot or more in diameter. Some of the 

masses of copper are enormous; one, for example, found in the Minnesota mine in 1857, weighed about 420 tons. It is associated with 

other minerals of hydrous origin, such as epidote, datolite, calcite, 

, ( and zeolites, and calcite crystals are known which had been coated 

with copper, and then overgrown with more calcite. Lane also mentions a quartz crystal which had been corroded and mainly replaced 

by copper. Frequently the copper incloses nodules of native silver, 

which were evidently precipitated first and then enveloped by the 

baser metal. Had these metals been deposited from a fused magma 

they would have formed, not separately, but as an alloy. The 

reducing agent, according to Pumpelly, was probably some compound 

of iron, oxide or silicate; and R. D. Irving substantiates this opinion 

by citing particles of cementing copper which inclosed cores of 

magnetite. Pumpelly's conclusion was based upon the constant association of the Lake Superior copper with epidote, delessite, and the 

green earth silicates, all of which are ferriferous. H. N. Stokes 5

» Am. Jour. Sci., 3d ser., vol. 38,1889, p. 405. 

\ z Prof. Paper U. S. Geol. Survey No. 43,1905, p. 101.

' > Jour. Chem. Soc., vol. 30,1876, p. 1. See also R*. Meldrum, Chem. News, vol. 78,1898, p. 209. 

^ « See H. Credner, Neues Jahrb., 1869, p. 1; R. Pumpelly, Am. Jour. Sci., 3d ser., vol. 2, 1871, p. 348; 

Geol. Survey Michigan, vol. 1, pt. 2, 1873, and Proc. Am. Acad., vol. 13,1878, p. 253; M. E. Wadsworth, 

Bull. Mus. Comp. Zool., vol. 7,1880, p. 1; R. D. Irving, Mon. U. S. Geol. Survey, vol. 5,1883, chapter 10; 

A. C. Lane, Rept. State Bd. Geol. Survey Michigan, 1903, p. 239; Quart. Bull. Canadian Min. Inst., No. 13, 

1911, p. 81; and two volumes on the Keweenaw series, published by the Michigan Survey in 1911. In tho 

 », Keweenawan rocks of Minnesota F. F. Grout (Econ. Geology, vol. 5, 1910, p. 471) has found from 0.012 

to 0-029 per cent of copper. 

» Boon. Geology, vol. 1, p. 648,1906.
662 DATA OF GEOCHEMISTRY. . \

I

has; found that hornblende and siderite can precipitate metallic copper from a sulphate solution heated to 200°. Under certain condi^ 

tions, also,ferrous sulphate, pyrite, and chalcocite are capable, according to Stokes, of reducing cupric sulphate to the metallic state. Copper itself reacts with cupric sulphate solutions, reducing them to 

cuprous form. When such a solution of cuprous sulphate is produced ^ 

at a high temperature, it.deposits crystallized metallic copper upon 

cooling.1 In this way a hot ascending solution of cupric sulphate 

may dissolve copper and redeposit it at a higher, cooler level. H. C. 

Biddle,2 by heating a solution of ferrous chloride, cupric chloride, 

and potassium bicarbonate in an atmosphere of carbon dioxide under 

pressure, obtained a precipitate containing metallic copper. A. 

Gautier 3 has shown that superheated steam will reduce cuprous 

sulphide, chalcocite, to the metallic state, according to the reaction 

Cu2S + 2H2O = 2Cu + SO, + 2H2 .

Some experiments conducted in the physical laboratory of the 

United States Geological Survey 4 are very suggestive as regards the 

crystallization of copper and silver. Water, ammonium chloride, and 

tremolite were heated together during three and a half days, at 465° 

to 540°, in a steel bomb lined with a silver-plated copper tube. The 

tube was attacked near its base, and the two metals were redeposited 

in separate crystals in the upper and cooler regions of the apparatus. 

In the lower, hotter part an alloy of silver and copper was formed.

In some cases organic matter is evidently the reducing agent. H. ^ 

de Senarmont 5 showed that copper solutions were thus reduced at 

temperatures between 150° and 250°. R. Beck 6 mentions native 

copper filling the marrow cavities of fossil bones in the Peruvian 

sandstones of Corocoro, Bolivia. The films of copper often found in 

shales, as, for example, near Enid, Oklahoma, 7 were doubtless precipitated by substances of organic origin.8 ^

On the other hand, copper readily undergoes oxidation, yielding 

cuprite, malachite, and sometimes azurite. All of these species are 

known to occur as coatings upon the native metal. On buried

1 Stokes, Econ. Geology, vol. 1,1906, p. 648. See also earlier investigations cited by Stokes.

2 Jour. Geology, vol. 9, 1901, p. 430; and Am. Chem. Jour., vol. 26, 1901, p. 377. G. Fcrnekes (Econ. 

Geology, vol. 2,1907, p. 581) has also described the precipitation of copper from neutral chloride solutions 

by FeCl2 . See also C. F. Tolman and J. D. Clark, idem, vol. 9, 1914, p. 569, on the behavior of copper in '- 

electrolytic and colloidal solutions.

«Compt. Rend., vol. 142,1906, p. 1465. 

* Preliminary notice by F. E. Wright, Science, vol. 25, 1907, p. 389.

«Annales chim. phys., 3d ser., vol. 32,1851, p. 140. \x

* Ore deposits, Weed's translation, p. 499. 

. ' See E. Haworth and J. Bennett, Bull. Geol. Soc. America, vol. 12,1900, p. 2.

8 The association of copper ores, other than native copper, with organic remains is by no means rare. 

For example, E. J. Schmitz (Trans. Am. Inst. Min. Eng.,.vol. 26, 1896, p. 101) mentions impregnations 

of copper in fossil wood in the Permian of Texas. Percy (Metallurgy, vol. 1,1875, p. 211) refers to a cuprif- ^ 

erous peat in Wales which had actually been worked as an ore. Its ash contained about 3 per cent of 

copper.

V
METALLIC ORES. 663

Chinese copper coins of the seventh century A. F. Rogers 1 identified 

cuprite, malachite, azurite, cerusite, and occasional crystals of 

metallic copper. In the last case the oxidation had been followed 

by a reduction. Other similar examples are known.

Among the less important ores of copper there are three arsenides, 

an antimonide, some selenides, and a telluride. The arsenides are 

domeykite, Cu3As; algodonite, Cu6As; and whitneyite, Cu9As. 

Mohawkite is a domeykite containing several per cent of cobalt and 

nickel. Domeykite was produced artificially by G. A. Koenig, 2 who 

passed the vapor of arsenic over red-hot copper. Horsfordite is the 

antimonide, Cu6Sb. Two selenides are known, namely, berzelianite, 

Cu2Se, and umangite, Cu3Se2 . Crookesite is a selenide of copper, 

silver, and thallium, and rickardite is the telluride, Cu4Te3 . In the 

electrolytic refining of copper at Baltimore considerable quantities 

of tellurium accumulate in the slimes. It was probably diffused as 

telluride of copper in the original ores.

The sulphides of copper and its double sulphides with iron are the 

most important ores of this metal. Their composition is shown in 

the subjoined fonnulse:

Chalcocite................................................... Cu2S.

Covellite.......:........................................... .CuS.

Chalcopyrite................................................CuFeS2 .

Chalmersite 3 .................................................CuFe-jSg.

Cubanite-..................................................CuFe2S4 .

Bornite 4 ................................................... .Cu6FeS4 .

To this list the rare cobalt copper sulphide, carrollite, CuCo2S4 , may 

be added.

Several of these species have been found as furnace products, or 

obtained by intentional syntheses. As a furnace product, chalcopyrite has been several times reported; and A. N. Winchell 5 found it, 

together with bornite, thus formed, probably by sublimation, at 

Butte, Montana. On another product from the same locality, W. P. 

Headden 6 discovered cubanite. Chalcopyrite was first prepared by 

J. Fournet, 7 who simply fused pyrite and copper sulphide together.

1 Am. Geologist, vol. 31, 1903, p. 43. Similar coins, probably from the same find, are in the collections 

of the United States National Museum. A. Lacroix, Bull. Soc. min., vol. 32, 1909, p. 334, has reported 

chalcocite on ancient Roman coins.

2 Am. Jour. Sci., 4th ser., vol. 10,1900, p. 439.

»See E. Hussak,Centralbl. Min., Geol.u. Pal., 1906,p. 332. K. Schneider (Jour.prakt. Chemie, 2d ser., 

vol. 52,1895, p. 555) gives the formula here assigned to chalmersite to cubanite. According to B. L. Johnson, 

Chalmersite is abundant in some mines of Prince William Sound, Alaska. See Econ. Geology, vol. 12,1917, 

p. 519.

«Formula as established by B. J. Harrington, Am. Jour. Sci., 4th ser., vol. 16,1903, p. 151. The older, 

commonly accepted formula is Cu3FeS3 . On serial relations between the copper-iron sulphides, see E. H. 

Krausand P. Goldsberry, Am. Jour. Sci.; 4th ser., vol. 37,1914, p. 539. An important preliminary paper on 

these ores, by L. C. Graton and J. Murdoch is in Trans. Am. Inst. Min. Eng., vol. 45,1914. p. 26. On the 

composition of bornite, see A. F. Rogers, Science, vol. 42,1915, p. 387

6 Am. Geologist, vol. 28,1901, p. 244.

« Proc. Colorado Sci. Soc., vol. 8,1905, p. 39.

7 Annalos des mines, 3d ser., vol. 4,1833, p. 3.
664 DATA OF GEOCHEMISTRY.

F. de Marigny 1 obtained bornite by fusing pyrite with copper turnings and sulphur, a process essentially identical with Fournet's, the 

difference in product probably depending upon the proportions of 

the materials used.

J. Durocher,2 by the action of hydrogen sulphide upon the vapor 

of copper chloride, obtained copper sulphide in hexagonal tables, 

H. de Senarmont 3 heated a solution containing ferrous and cuprous 

chlorides, sodium persulphide, and a large excess of sodium bicarbonate to 250°, and so produced an amorphous precipitate having 

the composition of chalcopyrite. According to C. Doelter,4 malachite, 

heated with hydrogen sulphide solution to 80°-90° in a sealed tube, 

yields covellite. Cupric oxide, heated to 200° in a stream of hydrogen sulphide, was converted into covellite; at higher temperatures 

chalcocite formed. By gently heating a mixture corresponding to 

20uO + Fe203 in gaseous hydrogen sulphide, Doelter obtained chalcopyrite; and from a mixture of cuprous, cupric, and ferric oxides 

in the same gas at 100° to 200° he prepared bornite. E. Weinschenk 5 

effected the synthesis of both chalcocite and covellite by heating 

cuprous or cupric solutions with ammonium sulphocyanate to 80° 

in sealed tubes. It must be remembered in this connection that the 

sulphocyanate serves merely as a source of hydrogen sulphide under 

pressure.. A. F. Kogers 6 obtained covellite by heating sphalerite in 

a solution of copper sulphate at 150°-200° in a sealed tube; and E. A. 

Stephenson 7 found that when solutions of sulphides were heated insealed copper tubes, the tubes became lined with crystals of chalcocite.

A very complete synthetic investigation of the two copper sulphides is due to E. Posnjak, E. T. Alien, and H. E. Merwin.8 who 

fused copper and sulphur together and produced chalcocite. This, 

however, was always variable in composition, for the reason that an 

excess of sulphur was always present, in some form of solid solution. 

By heating the impure compound in a vacuum furnace to its melting 

point, 1,130°, pure chalcocite was obtained. Covellite was formed 

when either metallic copper or chalcocite was heated in a stream of 

hydrogen sulphide.

At several of the French thermal springs, Bourbonne-les-Bains, 

Plombieres, etc., A. Daubree Q found Roman coins and metals upon

1 Compt. Rend., vol. 58,1864, p. 967. 

J Compt. Rend., vol. 32,1851, p. 825. 

a Annales chim. phys.,3dser., vol. 32,1851, p. 166.. 

«Zeitschr. Kryst. Min., vol. 11,1886, pp. 34-36. 

'Idem, vol. 17,1890,p. 497. 

e School of Mines Quart., vol. 32,1911, p. 298. 

' Jour. Geology, vol. 24,1916, p. 189. 

s Econ. Geology, vol. 10,1915, p. 491.

»Annalesdesmines,7thser., vol. 8,1875,p. 439; Compt. Rend., vol.80,1875,p.461; Etudessynthetiqucs 

de g<5ologie exp6rimontale, pp. 72-86. See also A. Lacroix, Bull. Soc. min., vol. 32,1909, p. 333.
METALLIC ORES. 665

which, derived from the bronze, chalcocite,, chalcopyrite, bornite, and 

tetrahedrite had formed. Similar observations were made by C. A. 

de Gouvenain * at Bourbon-rArchambault. E. Chuard 2 found chalcopyrite upon bronze articles from the Swiss lake dwellings. In all 

of these instances the copper of the bronze had been attacked by 

waters containing either hydrogen sulphides or alkaline sulphides.

Of these sulphide ores, chalcopyrite, bornite, and chalcocite are by 

far the most important. Chalcopyrite and bornite are probably the 

primary compounds from which the others are in most cases derived, 

and they have been repeatedly identified as of magmatic origin. In 

Tuscany, according to B. Lotti,3 pyrite, chalcopyrite, bornite, ehalcocite, and sometimes blende or galena, occur in serpentinized rocks as 

original segregations. Similar occurrences in Serbia are reported by 

K. Beck and Baron W. von Fircks 4 and in dioritic rocks at Ookiep, 

Namaqualand, by A. Schenck.5 In a pegmatite near Princeton, 

British Columbia, J. F. Kemp 6 found bornite, which had all the 

appearance of a primary mineral. To original sources of this kind, 

segregated or disseminated sulphides, the other concentrations of 

copper ores may reasonably be attributed. These minerals are found 

also in veins, in contact zones, and in impregnations or replacements 

in sedimentary rocks, but the home of the copper in the first place 

must have been in rocks of igneous origin. To these primitive ores 

the syntheses by fusion may have some relation ; secondary depositions originated by other methods.

From chalcopyrite or bornite, commonly admixed with pyrite, the 

other ores of this group are generated. At a locality in the Altai 

Mountains, says P. Jereme'ef,7 every stage of transition from chalcopyrite to chalcocite may be observed. In the secondary enrichment 

of copper ores, pyrite plays an important part. Cupric solutions, 

formed by oxidation of ores in the upper levels of an ore body, react 

upon pyrite, and chalcocite is formed. This reaction has been partially studied by H. V. Winchell,8 who treated cupriferous pyrite 

with dilute solutions of copper sulphate and sulphur dioxide and. 

obtained films of cuprous sulphide. 0 The sulphides of arsenic, lead, 

and zinc precipitated copper sulphide from sulphate in the same way.

1 Coinpt. Rend., vol. 80,1875, p. 1297.

2 Idem, vol. 113,1891, p. 194.

3 Bull. Soc. g6ol. Belgicmc, vol. 3, Mem., 1889, p. 179. 

«Zeitschr. prakt. Gcologie, 19Q1, p. 321.

<>Zeitschn Dcutsch. gcol. Gescll., vol. 53, \*orhandl., 1901, p. 64. See also AV. H. Wood, Eng. and Min. 

Jour., vol. 79, 1905, p: 272. 

8 Trails. Am. lust. Mm. Eng., vol. 31, 1901, p. 182. See also J. Catharinct, Kng. and Min. .Tour., vol. 79,

1905. p. 125. Primary bornite and chalcopyrite in a dioritic rock of Plumas County, California, arc reported 

by H. W. Turner and A. F. Rogers, Econ. Geology, vol. 9, p. 359,1914.

'Zeitschr. Kryst. Miu., vol. 31,1899, p. 508.

8 Bull. Gcol. Soc. America, vol. 14,1903, p. 269. See also T. T. Read, Bull. Am. Inst. Min. Eng., March,

1906. p. 261, and E. C. Sullivan, idem; January, 1907, p. 143.
666 DATA OF GEOCHEMISTRY.

V

Chalcocite is thus formed both.from pyrite and zinc blende, according to W. Lindgren,1 at Clifton and Morenci, in Arizona. Chalcocite 

itself alters into chalcopyrite, bornite, and covellite,2 the last species 

being almost invariably of secondary origin. Covellite heated with 

a solution of sodium bicarbonate was found by H. N. Stokes 3 to 

yield chalcocite; and chalcocite reacts with copper sulphate to form 

both covellite and native copper. The precipitation of chalcocite by 

pyrite was also verified by Stokes.4 In short, these minerals are quite 

generally convertible one into another by very varied reactions, and 

their paragenesis, therefore, must be studied independently for each 'j 

deposit in which they occur. 5 \ 

In the experimental study of secondary enrichments the recent / 

investigation by E. G. Zies, E. T. Allea, and H. E. Merwin 6 are of 

much significance. They heated various sulphides in sealed tubes at 

different temperatures from 200° downward, with solutions of copper V 

sulphate, and noted the following transformations: :r

Pyrite to covellite and chalcocite.

Pyrrhotite to chalcopyrite and probably bornite.

Chalcopyrite to covellite and chalcocite.

Bornite to chalcocite.

Covellite to chalcocite.

Sphalerite and galena, first to covellite and then to chalcocite.

These changes are significant for the reason that copper sulphate is 

the reagent most commonly formed near the top of an ore body and . 

transferred thence in solution downward. The changes produced 

artificially are the ones which are most likely to occur. What variations from them, might be produced by other constituents of the (- 

enriching solution is not clear, but they are. not likely to be of great 

importance. The migration of unoxidized sulphides should, however, be taken into account. The total of enrichment may be the 

result of several distinct processes. 7 ^

Among the sulphosalts there are a number containing copper, as * 

follows:

' Prof. Paper U. S. Geol. Survey No. 43,1905, pp. 182-186. j

2 See Dana's System of mineralogy, 6th ed., p. 56. . t

' Econ. Geology, vol. 2,1907, p. 14. ?

« Bull. U. S. Geol. Survey No. 186,1900, p. 44. . *'

s At Copper Mountain, British Columbia, according to Kemp (Econ. Geology, vol. 1, 1905, p. 11), the

original ore was bornite; and from that mineral covellite with limonite, then chalcocite, and finally chalco- V -

cite with chalcopyrite were successively derived. See also J. Catharinct, Eng. and Min. Jour., vol. 79, ^

1905, p. 125. On secondary enrichm'ent of chalcocite ores seg A. C. Spencer, Econ. Geology, vol. 8,1913, '

p. 621. ' <

6 Econ. Geology, vol. 11,1906, p. 407. ^

' See also S. W. Young and N. P. Moore (Econ. Geology, vol. 11,1916, pp. 349, 574) on the influence of (

H2S in the enrichment of copper ore. * ?
METALLIC ORBS. 667

Chalcostibite...........'..............._...-................ .CuSbS2 .

Emplectite...............................................CuBiS2 .

Stylotypite l . ...........................°..................Cu3SbS3 .

Bournonite.............................................. -CuPbSbS3 . Wittichenite............................................ .Cu3BiS3 .

Aikenite..... ...\ .........................................CuPbBiS3 .

Enargite. ...'......................................-..... .CuqAsS4 .

Famatinite. ............................................ -Cu8SbS4 .

Tennantite................................................Cu8As2S7 .

Tetrahedrite................................ v .............Cu8Sb2S7 .

Klaprotholite. .......................................... -Cu6Bi4S9 .

Epigenite 2 . ...............................................Cu7As2S12 .

Cuprobiemutite............................................CiicBi8Si6 .

The foregoing formulae are typical and make no allowance for the 

frequent replacements of copper by other metals, or of bismuth, 

antimony, and arsenic by one another. For example, there are intermediate mixtures between tennantite and tetrahedrite, and bismuth, 

presumably as Cu8Bi2S7 , is sometimes present in them. There are 

also varieties of these minerals containing very notable proportions 

of silver, mercury, zinc, or lead; but all reduce to the same general 

type of formula.3

R. Schneider 4 by passing hydrogen sulphide into a solution containing bismuth trichloride and cuprous chloride obtained a precipitate having the composition of wittichenite. By subsequent fusion 

this product assumed the character of the natural mineral. In a 

later investigation 5 he treated a solution of cuprous chloride with the 

potassium salt KBiS2 and produced a compound which, after special 

purification and fusion, resembled emplectite. He also prepared 

emplectite by fusing cuprous sulphide and bismuth sulphide together. 

The synthesis of bournonite was effected by C. Doelter 6 when a 

proper mixture of the chlorides or oxycompounds of copper, lead, and 

antimony was heated in a stream of hydrogen sulphide to a temperature below redness. Above that, temperature the antimony compounds volatilize. Evidently the sulphosalts of arsenic and antimony can be generated only at relatively low temperatures. By 

heating cuprous chloride with antimony sulphide to 300VH. Sommerlad 7 prepared chalcostibite. Another preparation corresponding to Cu2Sb4S7 , was similarly obtained. By fusing together .their 

component elements, in proper proportion, F: Ducatte f obtained 

emplectite, aikenite,' and wittichenite.

1 Copper partly replaced by silver and iron.

2 Copper partly replaced by iron.

3 On the composition of tetrahedrite (fahlorz) see A. Kretschmer, Zeitschr. Kryst. Min., vol. 48, 1010, p. 

484. -.... 

4 Pogg. Annalen, vol. 127, 1866, p. 316.

6 Jour, prakt. Chemie, 2d ser., vol. 40, 1889, p. 564. 

«Zeitschr. Kryst. Min., vol. 11, 1886, p. 38.

7 Zeitschr. anorg. Chemie, vol. 18, 1898, p. 420.

8 Thesis, Univ. Paris, 1902.
668 DATA OF GEOCHEMISTRY.

S 

Of these sulphosalts, only- enargite, tetrahedrite, tennantite, and

bournonite are at all common. The other species are rarities. Enargite is an important ore at Butte, Montana, 1 and in the Tintic mines, 

Utah, it is the parent of a number of rare copper arsenates. Of 

the latter class, produced by the oxidation of enargite, W. F. Hillebrand 2 has identified olivenite, erinite, tyrolite, chalcophyllite, clino- ( 

clasite, mixite, conichalcite, and chenevixite. Several other natural 

arsenates of copper are known, and a number of phosphates; but 

they need no further consideration here.

The two oxides of copper, cuprite, Cu2 0, and tenorite, CuO, are 

well-known ores of secondary origin. Cuprite, which is by far the - more common, has been repeatedly observed as a furnace product,3 ' 

and also as an incrustation upon ancient objects of copper or bronze.4 ^ 

Both compounds are easily prepared synthetically. Crednerite is 

another oxidized compound, having the formula Cu2Mn4O9 . On V 

earthy oxide of manganese containing copper is known as lampadite.

Cuprous chloride, nantokite, CuCl, and the iodide, marshite, Cul, - 

are rare minerals of slight importance. The oxychloride, atacamite, 

Cu2Cl(OH) 3 , is more common, and in Chile it has some significance 

as an ore.5 Several syntheses of it have been reported. F. Field 6 

obtained atacamite by the action of calcium hypochlorite upon a solution of copper sulphate. C. Friedel 7 obtained it by heating a solution 

of ferric chloride with cuprous oxide to 250°. Neither of these syntheses, however, corresponds to any probable process in nature. The 

observed development of atacamite upon ancient copper and bronze 

gives a better notion of its genesis. G. Tschermak 8 reports an alteration of atacamite to malachite, and has shown that the change can ; 

be artificially reproduced when the oxychloride is slowly digested 

with sodium bicarbonate. Pseudomorphs of chrysocolla after atacamite have been described by C. Barwald.9 \,

The sulphates of copper, normal, basic, and double, are represented ' 

by a number of mineral species, but only two of them are important. 

These are the normal salt, chalcanthite, CuSO4 .5H2O; and the basic 

brochantite, Cu4S04 (OH)6 . Chalcanthite is deposited in crystalline 

form by the evaporation of cupriferous mine waters, and in some 

localities it is actually a workable ore. For example, at Copaquire,

1 On secondary enrichment at Butte see A. N. Rogers, Econ. Geology, vol. 8,1913, p. 781. On the para- > genesis of the Butte ores see J. C. Ray, idem, vol. 9,1914, p. 463. For experiments relative to copper enrichment see G. S. Nishihara, idem, p. 743.

» Bull. U. S. Geol. Survey No. 20, 1885, and No. 55, 1889.- f

' See, for example, A. Arzruni, Zeitschr. Kryst. Min., vol. 18,1891, p. 58.

4 In addition to cases already cited, see A. Lacroix, Bull. Soc. min., vol. 6, p. ITS.

6 For a description of an atacamite ore body, see J. A. W. Murdoch, Trans. Inst. Min. Met., vol. 9,1901, 

p. 300.

« Philos. Mag., 4th ser., vol. 24, 1862, p. 123.

i Compt. Rend., vol. 77, 1873, p. 211.

8 Jahrb. K.-k. geol. Reichsanstalt, vol. 23, Min. Mitt., p. 41. +

8 Zeitschr. Kryst. Min., vol. 7,1883, p. 169.
METALLIC ORES. 669

Chile, according to H. Oehmichen,1 chalcanthite is found in significant quantities as an impregnation in partially decomposed granitic 

rocks, associated with some malachite, azurite, and chrysocolla. 

Pyrite and chalcopyrite are also present, the oxidation of the latter 

mineral having furnished the sulphate. Brochantite, a rarer species, 

appears to be more common than is generally supposed. W. Lindgren 2 has called attention to its presence in the Clif ton-Morenci mines 

of Arizona, where it occurs in fibrous forms which might easily be 

mistaken for malachite. F. Field 3 prepared brochantite artificially 

by boiling a solution of copper sulphate with a very small quantity 

of caustic potash. S. Meunier 4 obtained it when copper sulphate 

solution was allowed to act during eleven months upon fragments of 

galena. Apparently, brochantite is easily formed by natural 

reactions.

Two basic carbonates of copper are common secondary ores. They 

are malachite, Cu2 (OH)2C03 , and azurite, Cu3 (OH)2 (C03 )2 . Both 

species are formed in the upper portions of ore deposits, by the 

action of carbonated waters upon copper compounds, or by reactions 

between cupreous solutions and limestones. They also are found in 

the patina of ancient bronzes. A. de Schulten 5 prepared malachite 

by heating precipitated copper carbonate with a solution of ammonium carbonate on a water bath during eight days. Later,6 upon 

heating a solution of copper carbonate hi carbonated water, he 

obtained a precipitate of malachite. L. Michel 7 reproduced azurite, 

together with the basic nitrate, gerhardtite, by leaving a solution of 

copper nitrate in contact with fragments of Iceland spar for several 

years.

Several silicates of copper are known. One of them, chrysocolla, 

CuSi03 .2H20, is common; the others, dioptase, CuELjSiO^ bisbeeite, 

v isomeric with dioptase, shattuckite, CuH2Si2 07 , and plancMite, 

H4Cu6Si5O18 , are rare.8

 A. C. Becquerel 9 obtained dioptase artificially by allowing a solution of potassium silicate to diffuse very slowly into one of copper 

nitrate. Chrysocolla is probably formed by the action of percolating waters, carrying silica, upon other soluble compounds of copiper. 

Possibly, also, it may be produced during processes of -secondary 

enrichment. E. C. Sullivan 10 has shown that powdered s,hale,"feld1 Zeitschr. prakt. Gcologie, 1902, p. 147.

a Prof. Paper U. S. Gcol. Survey No. 43,1905, p. 119.

3 Philos. Mag., 4th ser., vol. 24,1862, p. 123.

< Compt. Rend., vol. 86, 1878, p. 686.

' Idem, vol. 110,1890, p. 202. - '

8 Idem, vol. 122,1896, p. 1352.

7 Bull. Soc. min., vol. 13, 1890, p. 139.

8 On planchdito, see A. Lacroix, >Iineralogie de la France, vol. 4, p. 757, 1910. On shattuckito and bislieeite, see W. T. Schaller, Jour. Washington Acad. Sci., vol. 5, p. 7,1915. 

» Compt. Rend., vol. 67,1868, p. 1081. 

i» Econ. Geology, vol. 1, 1905, p. 67. Complete report in Bull. U. S. Oeol. Survey No. 312; 1907.
670 DATA OF GEOCHEMISTRY.

spar, biotite, etc., will withdraw copper from sulphate solutions, the 

reaction being one of double decomposition. The ordinary silicates 

lose alkalies or alkaline earths, which pass into solution and are 

replaced by copper. The cupriferous product may be partly silicate 

and partly hydrous oxides, but its investigation is as yet incomplete.

MERCURY.

Unlike gold, silver, and copper, mercury appears to be not widely 

diffused in nature, although it must be admitted that minute traces 

of the element are easily overlooked. Very small quantities of the 

precious metals can be determined by fire assay, but the volatility of 

mercury prevents its detection by such simple means.

Apart from the natural amalgams of silver and gold, which have 

already been mentioned, mercury occurs in the following minerals:

Native mercury.......................................Hg.

Cinnabar............................................. -HgS.

Metacinnabarite l ......................................HgS.

Tiemannite.. .........................................HgSe.

Coloradoite.................................."..........HgTe.

Onofrite...............................................Hg(S,Se).

Lehrbacliite..........................................HgSe+PbSe.

Livingstonite.;....................................... .HgSb4S7 . Montroydite.................:........................ .HgO.

Calbmel. .............................................. -Hg2Cl2 .

Terlinguaite.......................................... -Hg2C10.

Eglestonite............................................Hg4Cl20.

To these must be added kleinite, a curious sulphato-chloride of 

one of the mercuramm onium bases and also the allied mosesite. 

Ammiolite and barcenite are antimonates or antimonites of mercury, 

of uncertain composition. The native iodide of mercury is said to 

exist, but its identity is more than doubtful. Mercury is also found 

in some tetrahedrite, in proportions ranging as high as 17 per cent. 

Very few of these minerals have any economic significance. Cinnabar is almost the sole ore of mercury, although the native metal is 

sometimes found in notable quantities. In some of the California 

mines metacinnabarite, the black sulphide, was once abundant, and 

tiemannite, the selenide of mercury, was commercially worked at one 

tune in the Lucky Boy claim in Utah.2 Livingstonite is a workable 

ore at Huitzuco in Mexico, and barcenite is a substance produced by 

its oxidation.3 Montroydite, terlinguaite, eglestonite, mosesite, and 

kleinite are secondary minerals, which occur in small quantities as

1 Guadalcazarite is metacinnabarite containing a little zinc.

2 See G. F. Becker, Mon. U. S. Geol. Survey, vol. 13,1888, p. 385.

a E. HalSe (Trans. North of England Inst. Min. and Mech. Eng., vol. 45, 1895-96, p. 72) has described 

this locality. He ascribes the formation of the ores to solfataric action. J. Mactear (Trans. Inst. Minand Met., vol. 4,1895, p. 69), H. F. Collins (idem, p. 120), and J. D. Villarello (Mem. Soc. cient. Ant. Alzate, 

vol. 19,1902, p. 94; vol. 20, 1903, p. 389; and vol. 23, 1906, p. 395) have also described the Mexican quicksilver deposits. Mactear regards them all as of aqueous and probably of thermal origin.
METALLIC ORES. 671

derivatives of cinnabar/ in the mines of Brewster County, Texas.1 

Calomel has been found at several localities, but always as a secondary species.

Mercuric sulphide, as shown in the list of mineral species, occurs 

in two forms the red, rhombohedral cinnabar and the black, isometric metacinnabarite. To the one species the artificial product 

vermilion corresponds, while the ordinary precipitated sulphide, 

familiar to all analysts, is amorphous and black. Vermilion is prepared by many processes, which differ in detail but can be referred 

to two simple types.2 Mercury and sulphur, under the influence of 

heat, unite directly, and upon subliming the product the scarlet pigment is obtained. The other general process is based upon the fact 

that the black sulphide, when acted upon by solutions of alkaline sulphides, can be converted into the red form. To these fundamental 

processes, the wet and the dry, the various syntheses of crystalline 

cinnabar correspond, with the wet methods predominating.

According to Fouque" and LSvy,3 J. Durocher obtained cinnabar by 

the action of hydrogen sulphide upon mercuric chloride at a red heat. 

They also state that Deville and Debray prepared the mineral by 

heating the black precipitated sulphide with hydrochloric acid in a 

sealed tube at 100°. .

C. Doelter's experiments 4 were also conducted in sealed tubes. 

Crystals of cinnabar were formed when metallic mercury was heated 

with hydrogen sulphide at 70° to 90° during six days. By heating 

mercury with a-solution of hy.drogen sulphide on a water bath he 

also produced both cinnabar and the black modification..

Several syntheses of cinnabar are based upon the solubility of mercuric sulphide in alkaline-sulphide solutions. M. C. Mehu 5 found 

that the mercuric compound was insoluble in either sodium hydroxide 

. or sodium sulphide, but soluble in a mixture of the two. On dilution, the mixture deposited the black sulphide; but upon the passage 

of carbon dioxide through the solution the red modification, cinnabar, 

was formed. According to S. B. Christy, 6 amorplious mercuric sul1 See A. J. Moses, Am. Jour. Sci., 4th ser., vol. 16, 1903, P- 253. Kleinite was erroneously described by 

A. Sachs, Sitzungsb. K. Akad. Wiss. Berlin, 1905, p. 1091. Its true composition was first indicated by 

Hillebrand, Am. Jour. Sci., 4th set., vol. 21, 1906, p. 85, and later confirmed by Sachs, Centralbl. Min., 

Geol. u. Pal., 1906, p. 200. For data concerning the Terlingua and other deposits of Brewster Cojonty, 

see B. F. Hill, Am. Jour. Sci., 4th ser., vol. 16, 1903, p. 251; E. P. Spalding, Eng. and Min. Jour., vol. 

71,1901, p. 749; R. T. Hill, idem, vol. 74,1902, p. 305; W. B. Phillips, idem, vol. 77, 1904, "p. 160; vol. 18, 

1904, p. 212; M. P. Kirk and J. W. Malcolmson, idem, vol. 77,1904, p. 684; and W. P. Blake, Trans. Am. 

Inst. Min. Eng., vol. 25, 1896, p. 68. For a full discussion with analyses, of the composition of the Terlingua minerals, see W. F. Hillebrand and W. T. Schaller, Jour. Am. Chem. Soc., vol. 29, 1907, p. 1180, 

and also, in detail, in Bull. U. S. Geol. Survey No. 405, 1910. On mosesite, see Hillebrand and Schaller, 

Am. Jour. Sci., 4th ser., vol. 30,1910, p. 202. '

* A good summary of the individual methods for the preparation of vermilion is given in Thorpe's Die-, 

tionary of applied chemistry, vol. 3, article "Mercury."

8 Synthese des mine'raux et des roches, p. 313. These data seem not to have.been published previously 

but to appear for the first time in the volume cited. '

4 Zeitschr. Kryst. Min., vol. 11, 1886, p. 33. .

' Jahresb. Chemie, 1876, p. 282.

3 Am. Jour. Sci., 3d ser., vol. 17,1879, p. 453.
672 DATA OF GEOCHEMISTRY.

phide, heated in a sealed tube with alkaline solutions into which 

hydrogen sulphide had been passed, is converted, at temperatures 

between 200° and 250°, into cinnabar.' This reaction is retarded by 

the presence of carbon dioxide. The black sulphide, by five hours of 

heating to 180° with °a solution of potassium sulphydrate, was also 

transformed into cinnabar. A similar transformation of vermilion 

into cinnabar is also reported by A. Ditte.1 When an excess of vermilion is slowly acted upon by a solution of potassium sulphide it 

gradually changes into the crystallized mineral. The reactions, as 

interpreted by Ditte, are rather complex, and involve the formation 

and decomposition of two double sulphides, K2HgS2 and K5Hg5Sa . 

The results are also modified by variations in temperature and in the 

concentration of the solutions employed. J. A. Ippen's 2 observations resemble those of Christy. The black precipitated sulphide of 

mercury, heated in a sealed tube with a solution of sodium sulphide 

for two .months below 45°, became crystallized as cinnabar. The 

same black sulphide, similarly treated with hydrochloric acid, failed 

to yield the red form.

L. L. de Koninck 3 found that mercuric sulphide is very soluble in 

concentrated solutions of the alkaline sulphides, and also in the 

sulphidesv of calcium, strontium, and barium, but not-in solutions of 

sulphydrates. Upon slow dilution of the mercuric solutions thus 

obtained, red crystalline cinnabar was precipitated. Upon rapid 

dilution, the black amorphous sulphide was thrown down.

In a research upon the enrichment of mercury deposits T. M. 

Broderick 4 found that cinnabar dissolved in chloride waters but not 

in sulphate waters. From the chloride solutions thus formed calcite. 

precipitates an oxychloride of mercury, but if ferrous sulphate is 

present, calomel is formed by reduction. Stibnite, a common associate of mercurial ores, precipitates metallic mercury.

E. Weinschenk 5 prepared cinnabar by a process remotely akin to 

those employed by Durocher and Doelter. A solution of mercuric 

chloride and ammonium sulphocyanate was heated in a sealed tube 

from four to six days at a temperature between 230° and 250°. Both 

cinnabar ,and a black sulphide were obtained. In this case the 

ammonium sulphocyanate merely served as a generator of hydrogen 

sulphide,^which was the active reagent.

E. T. Alien and J. L. Crenshaw 6 in a thorough study of mercuric 

sulphide determined the conditions of formation- of the two natural 

forms, and also discovered a third, probably hexagonal modification, which has not been found in nature. The stable form, cinnabar, 

was produced in the usual way, by the action of an alkaline sulphide 

upon the amorphous, precipitated compound. Metacinnabarite was

1 Compt. Rend., vol. 98,1884, pp. 1271,1380. " « Econ. Geology, vol. 11,1916, p. 645.

» Min. pet. Mitt., vol. 14,1894, p. 114. ' » Zeitschr. Kryst. Min., vol. 17,1890, p. 498.

8 Annales Soc. ge"ol..Belgique, vol. 18,1891, p. xxv. »Am. Jour. Sci., 4th ser., vol. 34,1912, p. 367.
METALLIC ORES. 673

formed by the action of an excess of sodium thiosulphate upon sodium 

mercuric chloride in dilute solution. This solution was rendered 

slightly acid. Under alkaline conditions only cinnabar is formed; 

acidity is essential to the production of the less stable meta-compound. 

This condition also holds with regard to pyrite and marcasite, and also 

with the two modifications of zinc sulphide. In each case acidity 

controls the generation of the less stable mineral, alkalinity that of 

the more stable. These facts are correlated with the natural occurrences of the minerals. Cinnabar, the primary form, is probably 

deposited by ascending solutions, which are commonly alkaline. 

Descending solutions, acid from the oxidation of iron sulphides, control the formation of the secondary metacinnabarite.

Finally, a crystalline mass resembling livingstonite was- prepared 

by A. L. Baker, 1 who fused the sulphides of mercury and antimony 

together in an atmosphere of carbon dioxide.

It will be noticed that several of the syntheses of cinnabar involve 

the solubility of mercuric sulphide in solutions of alkaline sulphides 

or sulphydrates.2 On this subject, apart from synthetic considerations, there is a copious literature, and the earlier observations are 

by no means concordant. Even the recent data appear to be often 

contradictory. De Koninck, for instance, as already cited, found 

that the sulphide was insoluble in alkaline sulphydrates; but according to G. F. Becker 3 this statement is true only for cold solutions. 

Mercuric sulphide, heated with a solution of sodium sulphydrate on 

the water bath, dissolves, doubtless forming a double salt of the 

formula HgS.%Na2S. Salts of this type must be produced whenever 

mercuric sulphide is dissolved in an alkaline solution, and Ditte's 

researches have told us something of their nature.* The solubility 

 of the mercuric sulphide manifestly depends upon considerations of 

temperature, pressure, concentration, and the nature of the solutions 

employed, whether neutral salts, sulphydrates, or polysulphides. 

That mercuric sulphide is precipitated again by dilution has been 

shown by various observers, and Becker 5 reports admixtures of 

metallic mercury in the sulphide thus thrown down. Here, then, 

we have a possible explanation of the frequent association of free 

mercury and the black metacinnabarite, although relief of pressure 

may be in some cases the equivalent of dilution as a precipitant. 

Organic matter, also, is a probable agent of reduction, by which the

1 Chem. News, vol. 42,1880, p. 196.

2 According to G. A. Binder (Min. pet. Mitt., vol. 12,1892, p. 332), even distilled water, acting on cinnabar 

for five weeks at 90°, will dissolve traces of the mineral. ' -

8 Am. Jour. Sci., 3d ser., vol. 33, 1887, p. 199. In detail, with full summaries of earlier work, in Mon. 

U. S. Geol. Survey, vol. 13,1888, chapter 15. Also, preliminary, in Eighth Ann. Kept. U. S. Geol. Survey, 

pt..2,1889, p. 985.

4 A compound 2Na2S.5HgS.3H2O has been isolated and described by J. Knox, Trans. Faraday Soc., 

vol'. 4, p. 29,1908.

& Am. Jour. Sci., 3d ser., vol. 33,1887, p. 199.

113750° 19 Bull. 695 43
674 DATA OF GEOCHEMISTRY. *

metal is liberated. Bituminous substances, such as idrialite, napalite, etc., are commonly associated with cinnabar; and at the Phoenix 

mine in California an inflammable gas issuing from cracks in the rocks 

was found by W. H. Melville * to have the following composition:

Composition of gas at Phoenix mine. 

C02 ........................................................ 0.74 (

CH4 . ....................................................... 61.49

N2 ........................................................... 31. 44

09 . ......................................................... 6.33

 :ioo. oo

The hydrocarbon CH4 , it must be observed, is the first member of 

the paraffin series, to which some bitumens belong. Becker 2 has 

shown that hydrocarbons will precipitate mercuric sulphide from its 

alkaline solutions, first, probably, as metacinnabarite, which is afterward slowly transformed into cinnabar. Another suggestion, due to 

A. Schrauf,3 who has studied the occurrence of mercury ores in Idria, 

is that the metal may be liberated by the direct dissociation of cinnabar vapor. He also ascribes the formation of some metacinnabarite to the action of hydrogen sulphide upon native mercury. Here 

again we are reminded that the same point may be reached by more 

than one road.

According to Becker,4 the chief deposits of mercurial ores are all 

in the neighborhood of igneous rocks, from which it is highly probable they were originally derived. The deep-seated granites, hi his 

opinion, form the principal source of the mercury. The ore bodies 

in some cases fill fissures, fractures, or cavities in rocks, the latter 

being commonly of sedimentary character; and in other instances 

the cinnabar forms impregnations in sandstone or limestone. The 

ores are commonly associated with pyrite or marcasite, sulphur, 

calcite, barite, gypsum, opal, quartz, and other secondary minerals, 

and show distinct evidence that they have been brought up from 

below in solution.5 In many cases, if not in all, the evidence of

 r^ 

1 Mon. U. S. Geol. Survey, vol. 13,1888, p. 373.

2 Mineral Resources U. S. for 1892, U. S. Geoi. Survey, 1893, p. 139.

s Jahrb. K.-k. geol. Reichsanstalt, vol. 41, 1892, pp. 383, 396. Schrauf gives many citations of literature relative to mercury, and especially to the mines of Idria. ' t

4 Mon. U. S. Geol. Survey, vol. 13, 1888, and also, briefly, in Mineral Resources U. S. for 1892, p. 139. 

In the monograph, Becker has summed up the conditions at all important localities as known in 1887.

s In addition to Becker's monograph, see J. A. Phillips, Quart. Jour. GeoL.Soc., vol. 35, 1879, p. 390; 

and J. Le Conte and W. B. Rising, Am. Jour. ScL, 3d ser., vol. 24,1882, p. 23, on Sulphur Bank, California. 

Le Conte (idem, vol. 25,1883, p. 424) has discussed the deposits at Steamboat Springs, Nevada. See also, 

on Californian quicksilver ores, W. Forstner, Eng. and Min. Jour., vol. 78, 1904, pp. 385, 426; and in Bull. 

No. 27, California State Mining Bureau. Wendeborn (Berg- u. hiittenm. Zeitung, vol. 63,1904, p. 274) has 

described mercury deposits in Oregon; and G. F. Monckton (Trans. Inst. Min. Eng. (British), vol. 27, 

1904, p. 463) those of British Columbia. For a study of the mercury mines at Mount Avala, Serbia, see 

H. Fischer, Zeitschr. prakt. Geologic, vol. 14, 1906, p. 245. For an account of the mines at Almaden, 

Spain, see H. Kuss, Annales des mines, 7th ser., vol. 13, 1878, p. 39. On Huancavelica, Peru, see A. F. 

TTmlauff, Bol. Cuerpo ingen. minas Peru, No. 7,1904. F. Katzer (Berg- u. hiittenm. Jahrbuch, vol. 55, 

1907, p. 145) has described the mercury deposits of Bosnia. A list of the principal mercury deposits of 

the world, by L. Demaret, is given in Annales des mines de Belgique, vol. 9,1904, p. 35. Mercury deposits 

in the Phoenix Mountains, Arizona, are described by F. C. Schrader in Bull. U. S. Geol. Survey No. 690^-D, 

1918,
METALLIC ORES. 675

hydrous or solfataric origin is very clear. A. Liversidge,1 . for example, reports mercury and mercuric sulphide in hot-spring deposits 

near Ohaiawai, New Zealand; and in 3,403 grams of a sinter from 

Steamboat Springs, Nevada, Becker and Melville 2 found 0.0070 

gram of HgS. In Becker's opinion alkaline solutions containing 

sulphides are the natural solvents of the mercurial compounds; 

although V. Spirek 3 describing the deposits at Monte Amiata, Tuscany, suggests that the mercury was first dissolved as sulphate and 

precipitated later by alkaline polysulphides. For this supposition 

there seems to be little or no positive evidence. At Idria, A. Schrauf 4 

found no indications of the existence of alkaline thermal springs 

a bit of negative testimony which may or may not be important. It 

is not necessary, however, to assume that the mercurial solutions have 

been the same at all localities. In fact, they must have varied both 

in their chemical composition and in the physical conditions under 

which they came to the surface. Even the differences in the rocks 

through which the solutions travel would modify their properties.

ZINC AND CADMIUM.

Zinc, as has been shown in the earlier portions of this chapter, 

is widely diffused in the rocks, and it also occurs in minute proportions in sea water. Cadmium is found associated with zinc, and 

the very rare metals gallium and indium are also obtained from zinc 

ores. 5 Zinc is about 200 times as abundant as cadmium. 6

Although native zinc has been several times reported, its existence 

is doubtful. None of the occurrences is completely authenticated. 

The fundamental ore of zinc is the sulphide, ZnS, known as sphalerite, blende, or blackjack when crystallized in the isometric system, 

or as wurtzite when it is hexagonal. Cadmium is found almost 

exclusively as the sulphide, CdS, orgreenockite, which is also hexagonal.7 Many massive blendes are really mixtures of sphalerite 

and wurtzite. 8 The rare mineral voltzite is an oxysulphide of zinc, 

4ZnS.ZnO.

1 Jour. Roy. Soc. New South Wales, vol. 11, p. 262. See also J. Park, Trans. New Zealand Inst., vol. 38, 

1904, p. 27. Park cites another memoir by A. P. Griffiths, in Trans. New Zealand Inst. Min. Eng., vol. 2, 

p. 48. A later report by J. M. Bell and E. de C. Clarke is in Bull. New Zealand Geol. Survey No. 8,1909, 

p. 87.

8 Mon. U. S. Geol. Survey, vol. 13,1888, p. 344.

8 Zeitschr. prakt. Geologic, 1897, p. 369; idem, 1902, p. 297. Spirek gives references to other literature 

concerning Monte Amiata. See also R. Rosenlecher, Zeitschr. prakt. Geologic, 1894, p. 337, on this and 

other Tuscan deposits. On the mines of Vallalta-Sagron, see A. Rzehak, idem, 1905, p. 325.

4 Jahrb. K.-k. geol. Reichsanstalt, vol. 41,1892, p. 379.

6 On the occurrence of gallium, indium, germanium, and other rare metals in zinc blende, see G. Urbain, 

Compt. Rend., vol. 149,1909, p. 602. Also A. del Campo y Cerdan, Jour. Chem. Soc., vol. 106, pt. 2, p. 270, 

abstract. On gallium from Missouri-blende, see W. F. Hillebrand and J. A. Scherrer, Jour. Ind. Eng. 

Chem., v01. 8,1916, p. 225.

o see F. W. Clarke and G. Stelger, Jour. Washington Acad. Sci., vol. 4,1914, p. 57.

7 A basic carbonate of cadmium, otavite, and the crystallized oxide, CdO, are known as rare minerals. 

A useful summary on cadmium and its occurrences, by E. Jensch, is in Ahren's Sammlung chemische 

technologische Vortrage, vol. 3,1899, p. 201.

 s See J. Noelting, Zeitschr. Kryst. Min., vol. 17,1890, p. 220.
676 . DATA OF GEOCHEMISTRY.

Sphalerite, wurtzite, and greenockite have all been prepared synthetically, and wurtzite has been repeatedly observed as a furnace 

product. 1 According to H. de Senarmont,2 sphalerite is formed when 

zinc solutions are heated in sealed tubes in an atmosphere of hydrogen sulphide a method which was also employed by H. Baubigny.' 

J. Durocher 4 prepared- sphalerite by heating zinc chloride in a 

stream of hydrogen sulphide. Cadmium chloride treated in the 

same way gave greenockite.

By fusing precipitated cadmium sulphide with potassium carbonate and sulphur E. Schiiler 5 obtained crystals of greenockite. This 

observation has since been verified by R. Schneider.6 H. SainteClaire Deville and H. Troost 7 fused zinc sulphate, calcium fluoride, 

and barium sulphide together, and produced crystals of wurtzite. 

With cadmium sulphate greenockite was formed. They also obtained 

wurtzite by passing hydrogen over red-hot zinc sulphide. The latter 

was decomposed, forming zinc vapor and hydrogen sulphide/which 

reacted in the cooler parts of the apparatus to produce the crystalline mineral. Wurtzite and greenockite were prepared by T. Sidot 8 

when zinc or cadmium oxide was heated in the vapor of sulphur. In 

another paper 9 he states that amorphous zinc sulphide, heated in 

an atmosphere of nitrogen or Of sulphur dioxide, crystallizes into 

wurtzite. P. Hautefeuille 10 heated zinc and cadmium sulphide 

under a layer of powdery alumina; the two compounds volatilized 

and were redeposited on the surface df the alumina as wurtzite or 

greenockite. He also found that blende, heated to redness, was 

transformed into wurtzite. R. Lorenz u obtained wurtzite and 

greenockite by acting on the vapor of zinc or cadmium with hydrogen sulphide. This process recalls that of Deville and Troost.

Two hydrochemical processes have also yielded greenockite. C. 

Geitner 12 heated metallic cadmium with sulphurous acid to 200° in 

a sealed tube. A mixture of amorphous and crystalline sulphide was 

deposited. A. Ditte 13 found that amorphous cadmium sulphide 

could be dissolved in ammonium sulphydrate, especially at a temperature of 60°. On cooling, crystals of greenockite and free sulphur 

were formed.

1 See W. Stahl, Berg- u. hiittenm. Zeitung, 1888, p. 207; H. Forstner, Zeitschr. Kryst. Min., vol. 5/.I.SS1, 

p. 3:53; and II. Traube, Neues Jahrb., Beil. Band 9,1894, p. 151.

2 Compt. Rend., vol. 32,1851, p. 409. The description of the process is very vague.

3 See L. Bourgeois, Reproduction artiflcielle des mine'raux, p. 28.

4 Compt. Rend., vol. 32,1851, p. 825.

' > Liebig's Annalen, vol. 87,1853, p. 34.

« Poggendorf's Annalen, vol. 149,1873, p. 391.

7 Compt. Rend., vol." 52,1861, p. 920.

8 Idem, vol. 02,1860, p. 999.

9 Idem, vol. 63, I860, p. 188. ' 

»> Idem, vol. 93,1881, p. 824. . " (

11 Ber. Deutsch. chem. Gesell., vol. 24,1891, p. 1501. ''

12 Liebig's Annalen, vol. 129,1864, p. 350.

13 Compt. Rend., vol. 85, p. 402, 1877.
METALLIC ORES. . 677

E. T. Alien and J. L. Crenshaw * prepared greenockite in large 

crystals by the method of Lorenz. Only one modification of the 

sulphide was obtained. Wurtzite was formed by sublimation of 

zinc sulphide at about 1,200°-1,300°, and also by the action of hydrogen sulphide, derived from sodium thiosulphate, on acid solutions of 

zinc sulphate at 250°. By heating amorphous zinc sulphide in a 

solution of sodium sulphide at 350° in a steel bomb they obtained good 

crystals of sphalerite. Sphalerite was also produced, like wurtzite, 

in acid solutions, but with weaker acid and at higher temperatures. 

In alkaline solutions only sphalerite was formed. This distinction 

between the two minerals is like that already mentioned with regard 

to the sulphides of mercury and of iron. Sphalerite was also crystallized from solution in molten sodium .chloride and potassium 

polysulphide. At 1,020° sphalerite is transformed'in to wurtzite.

For geological purposes the hydrochemical syntheses of blende 

are the only ones of much importance; and they are paralleled by 

certain natural and recent occurrences of the mineral. G. Bischof,2 

for example, mentions a sinter, formed within historical times in an 

old lead mine, which contained 37.57 per cent of ZnS. It was probably produced by the action of decaying wood upon the zinc-bearing 

mine waters. In North St. Louis, Missouri, H. A. Wheeler 3 found 

massive blende embedded in lignite, where it had evidently been 

formed by the reducing action of organic matter upon other zinc 

compounds. C. R. ,Keyes 4 speaks of blende crystals, one-fourth 

inch across, which had grown on iron nails immersed in a mine water 

during fifteen years. W. P. Jenney 5 also refers to the deposition of 

crystallized blende on the walls of a tunnel which had been closed 

and flooded for ten or twelve years. Some crystals were deposited 

on the pick marks left by the miners.

Zinc sulphide is also known in nature as a chemical precipitate. 

In workings at Galena, Kansas, large cavities have been found, filled 

with a white mud which consisted of nearly pure zinc sulphide 

mingled with acid water.6 Evidently the zinc had been dissolved, 

probably by the oxidation of blende, and then thrown down again, 

either by sulphureted waters or by organic matter. Natural solutions of zinc sulphate exist in the region around Joplin, and have 

already been described in previous portions of this volume.7 An 

occurrence of sphalerite as a primary mineral in granite has been

 ' Am. Jour. Sci., 4th ser., vol. 34,1912, p. 341; vol. 38,1914, p. 373.

2 Lehrbuch der chemlschen und pbysikalischen Geologic, 2d ed., vol. 1, p. 559.

3 Trans. Acad. Sci. St. Louis, vol. 7, 1895, p. 123. Other associations of sphalerite with coal, also in 

Missouri, are mentioned by W. P. Jenney, in Trans. Am. Inst. Min. Eng., vol. 33,1903, p. 460. 

* Trans. Am. Inst. Min. Eng., vol. 31,1901, p. 611.

6 Idem, vol. 33,1903, p. 470.

» Described by J. D. Robertson, Am-. Jour. Sci., 3d ser., vol. 40,1890, p. 160; and by M. W. lies and J. D. 

Hawkins, Eng. and Min. Jour., vol. 49,1890, p. 499.

7 See ante, p. 184.
678 DATA OF GEOCHEMISTRY.

reported by E. Kimanii. 1 Such sphalerite, if really of magmatic 

origin, must have formed below the transition temperature to wurtzite, namely, 1,020°.

The oxidized compounds of zinc, as natural minerals, are fairly 

numerous. The following species are especially noteworthy:

Zincite............................................ZnO.

Gahnite 2 ..........................................ZnAl204 .

Franklirdte 2 ......................................ZnFe204 .

Chalcophanite 2 .....................................Zn0.2Mn02 .2H20.

Smithsonite.......................................ZnCOg.

Hydrozincite......................................ZnC03 .2Zn02H2 . Willemite 3 ..... I..................................Zn2Si04 .

Calamine...........................................Zn2H2Si05 .

Clinohedrite.........................................ZnCaH2Si05 .

Hardystonite.......................................ZnCa2Si2 07 .

Hodgkinsoioite.....................................Zn2Mn(Si04 )(OE)2 .

To this list may be added the phosphates, hopeite, 4 parahopeite, 

and kehoeite; the arsenates, adamite, kottigite, and veszelyite; descloizite, a vanadate of lead and zinc; and the sulphates, goslarite 

and zincaluminite. Jeffersonite is a zinc-bearing pyroxene, and danalite is a silicate plus sulphide, of zinc, manganese, iron, and glucinum. None of these species needs further mention except goslarite, 

ZnS04 .7H2 0, which is the compound of zinc existing in mine waters 

and in zinciferous springs. When zinc is removed from an ore body 

by solution, it is carried in this form.

Some experiments upon the origin of oxidized zinc ores have been 

made by Y. T. Wang.5 He found that the oxidation of sphalerite 

was caused by solutions of a ferric salt, preferably the sulphate; but 

soluble salts pf copper, silver, and lead also had a powerful solvent 

action upon the mineral. With solutions of zinc bicarbonates precipitate the normal salt, ZnC03 . With neutral carbonates the basic 

salt, hydrozincite, is precipitated. Silicate solutions convert the 

zinc sulphate into calamine; and limestone in a zinc solution is transformed into smithsonite. These observations, however, are not particularly novel.

Zincite, the natural oxide of zinc, is well known as a furnace product, and it has also been repeatedly synthetized.6 According to A.

1 Zeitschr. prakt. Geologic, 1910, p. 123. On the relations of sphalerite to other minerals, see L. P. Teas, 

Bull. Am. Inst. Min. Eng., 1917, pp. 1917-1931.

»The formulae here given are ideal. Part of the zinc is commonly replaced by manganese or iron. 

' Troostite is a manganiferous willemite.

* For a synthesis of hopeite, see C. Friedel and E. Sarasin, Bull. Soc. min., vol. 2,1879, p. 153.

* Trans. Am. Inst. Min. Eng., vol. 52,1916, p. 657. On the oxidized zinc ores of Leadvillesee G. F. Loughlin, Bull. U. S. Geol. Survey No. 681,1918.

8 See H. Traube, Neues Jahrb., Beil. Band 9, 1894, p. 151; and H. Ries, Am. Jour. Sci., 3d ser., vol. 48, 

1894, p. 256, on zincite as a furnace product. See also J. T. Cundell and A. Hutchinson, Mineralog. Mag., 

vol. 9,1892, p. 5. L. Bourgeois (Reproduction artificielle des min^raux) cites other examples, and so, 

too, does Ries. Bourgeois also mentions syntheses by Becquerel and Regnault, but his references are 

erroneous and I can not verify them.
METALLIC ORES. 679

Daubre'e,1 when zinc chloride and water vapor act upon lime at a red 

heat, zincite is formed. Ferrieres and Dupont 2 obtained it, at a 

similar temperature, by the action of steam upon zinc chloride alone. 

By heating the amorphous oxide in an atmosphere of oxygen, T. 

Sidot 3 was able to effect its crystallization. A. Gorgeu 4 prepared 

the mineral by several processes, one of which consisted in the gradual 

calcination of-zinc sulphate or nitrate. In this case better results 

were obtained when an alkaline sulphate was mingled with the zinc 

salt. Zincite was also formed when a mixture of zinc fluoride and 

potassium fluoride was strongly heated in a current of steam.

The zinc spinels, gahnite and franklinite, have also been artificially prepared. J. J. Ebelmen 5 obtained gahnite by fusing a mixture of alumina, zinc oxide, and boron trioxide. When ferric oxide 

was used in place of alumina, franklinite was formed. By vaporizing aluminum chloride and zinc chloride over lime at a red heat, 

A. Daubre'e 6 .prepared gahnite; and franklinite was similarly produced by using the- chlorides of iron and zinc. H. Sainte-Claire 

Deville and H. Caron 7 obtained gahnite by vaporizing a mixture of 

zinc and aluminum fluorides in presence of boric oxide. A. Stelzner 8 

found gahnite, with fayalite, in the walls of a muffle of a zinc furnace 

at Freiberg, where it had been formed by the action of zinc vapors 

upon the clay silicates. In another similar case, H. Schulze and 

Stelzner 9 report the formation of willemite and tridymite. The 

occurrence of crystallized willemite in a furnace slag has also been 

recorded by W. M. Hutchings. 10

According to A. Daubre'e, 0 willemite can be prepared by the action 

of silicon tetrachloride upon zinc oxide at a red heat. This, however, 

was denied by H. Sainte-Claire Deville, 11 who found.that willemite 

was decomposed by silicon chloride. - It is formed when silicon 

fluoride acts upon zinc oxide, and also by the action of zinc fluoride 

uponheated silica. A. Gorgeu 12 produced willemite'by two processes. 

First, zinc sulphate, calcined with an alkaline sulphate and silica, 

yields willemite and tridymite. Secondly, the mineral is formed 

when zinc chloride is fused with silica in presence of steam.

By heating metallic zinc with seltzer water in a sealed tube at 100°, 

L. Bourgeois 13 obtained crystals of smithsonite. G. Bischof 14 cites

1 Compt. Rend., vol. 39,1854, p. 135.

* See Bourgeois, op. cit., p. 56. 

»Compt. Rend., vol. 69,1869, p. 201. 

> < Idem, vol. 104,1887, p. 120.

 Annales cnim. phys., 3d sor., voL33,1861, p. 34.

«Compt. Rend., vol. 39,1854, p. 135.

7 Idem, vol. 46,1858, p. 766.

s Neues Jahrb., Band 1,1882, p. 170.

»Idem, Band 1,1881, p. 120. 

w Geol. Mag., 3d ser., vol. 7,1890, p. 31. 

" Compt Rend., vol. 52,1861, p. 1304. 

u> Idem, vol. 104,1887, p. 120. 

i" 'Reproduction artiflcielle des min^raux, p. 144. 

" Lehrbuch der chemischen und physikalischen Geologic, 2d ed., vol. 1, p. 561.
680 DATA OF GEOCHEMISTRY.

a number of instances in which zinc carbonate has formed as a 

deposit from natural waters.

In nature, zinc ores occur under a variety of conditions in true 

metalliferous veins, in metamorphic rocks, and under circumstances 

which indicate a sedimentary origin. In some cases they form 

metasomatic replacements of limestone. Percolating solutions of 

zinc, permeating limestones, would necessarily react upon the latter, 

the zinc being deposited as carbonate in place of the removed lime 

compounds. Pseudomorphs of smithsonite after calcite are well 

known. In an experiment reported by G. Piolti, 1 a fragment of 

calcite, immersed during 17^ years in a solution of zinc sulphate, 

became coated with smithsonite and gypsum.

In the introduction to this chapter evidence was adduced showing 

that zinc was present, albeit in small amounts, in Archean rocks, 

from which it may be concentrated. It is also found in diffused 

traces in many sedimentary rocks. L. Dieulafait 2 detected zinc in 

hundreds of samples of Jurassic limestone from central France. 

J. D. Robertson 3 found it, with lead and copper, in the limestones 

of Missouri, and J. B. Weems 4 determined lead and zinc hi the 

limestones and dolomites of the Dubuque region, Iowa. The average 

of nine samples analyzed by Weems gave 0.00326 per cent Pb and 

0.00029 per cent Zn. Robertson's figures are as follows for six 

Silurian magnesian limestones and seven limestones from the 

"Lower" Carboniferous; they are stated in percentages.

Lead, zinc, and copper in limestones.

Zinc......................................

^opper. ...................;..............

Silurian.

Trace to 0.00156

0.00016 to 0.01536

0.00040 to 0.00256

Lower Carboniferous.

Trace to 0.00346

Trace to 0.00255

Trace to 0.00880

Small as these proportions are, they are sufficient to account for 

the formation of the ore bodies in the regions studied. In each region 

a comparatively moderate amount of decomposition of the country 

rocks would supply the ores contained in the known deposits.5

Similar results to those of Weems and Robertson were obtained 

by A. M. Finlayson 6 in his study of the British lead and zinc deposits. 

These metals were found in the country rocks in quantities of the 

same order of magnitude, and were more abundant in the granites

1 Jour. Chem. Soc., vol. 100, p. 902,1911. Abstract. . 

' Compt. Rend., vol. 90,1880, p. 1573, and vol. 96,1883, p. 70. 

3 Missouri Geol. Survey, vol. 7,1894, pp. 479-481.

< Cited by S. Calvin and H. F. Bain, Iowa Geol. Survey, vol. 10,1900, p. 566.

6 See T. C. Chamberlin, Geology of Wisconsin, vol. 4,1882, pp. 367-553, and A. Winslow, Missouri Geol. 

Survey, vols. 6 and 7, especially vol. 7,1894, p. 467, etc. 

e Quart. Jour. Geol. Soc., vol. 66,1910, p. 299.
") METALLIC ORES. , 681

than in the limestones. Finlayson regards the metals as having been 

brought up in solution from below, in waters which contained alkaline sulphides and also fluorine. The order of deposition of the vein 

minerals was chalcopyrite, first, then fluorite, blende, galena, and 

finally pyrite.

This association of sphalerite with other sulphides is very general, 

so much so that economic geologists usually consider lead and zinc 

together. In the famous ore bodies of the Mississippi Valley the two 

£ ores are rarely found quite apart, although in one locality zinc may 

predominate, while lead is the chief thing of value in another. Calcite, dolomite, and sometimes fluorite or barite are frequent companions of the ores, and bituminous matter is often present also. By 

alteration of sphalerite, surface deposits of calamine and smithsonite 

are formed, just as oxidized ores are developed above bodies of copper

sulphide. Secondary crystallizations of sphalerite are also common

where solutions of zinc sulphate, formed near the top.of an ore body,

v have percolated downward, and been reduced to sulphide again. It

/ is highly probable that pyrite or marcasite may react upon the zincbearing solutions and aid in the regeneration of the sphalerite. Some 

experiments by H. N. Stokes,1 carried out in the laboratory of the 

United States Geological Survey, have shown the possibility of such 

reactions. Pyrite and marcasite heated to 180° with solutions of zinc 

salts and alkaline carbonates actually yield zinc sulphide. Sphalerite 

sometimes occurs in stalactitic forms, which could be deposited only 

from solutions. The- calamine and smithsonite are sometimes pure 

and crystalline, sometimes quite impure and earthy. The so-called 

"tallow clays" of Missouri and Arkansas are zinc-bearing clays, probably mixtures of aluminous silicates with calamine, and they contain

' frojn 4 to 5 per cent up to 56 per cent of zinc oxide.2 Similar clays, 

from an ore body at Leadville, Colorado, were analyzed by W. F.

 ^ Hillebrand.3

On the sedimentary lead and zinc ores of the Mississippi Valley 

there is a copious literature, with much discussion about genetic problems. Some authorities derive the ores from ascending, heated

' waters; some find their proximate sources in the adjacent limestones, 

and others trace them still further back to Archean rocks, or argue 

that the zinc and lead were deposited with the sediments from solution in the Silurian ocean. All agree, however, that the ores were

1 Econ. Geology, vol. 2,1907, p. 17. See also the work of Anthon, Schurmann, and others, already cited 

on p. 643, ante. 

»See W. H. Seamon, Am. Jour. Sci., 3d ser., vol. 39,1890, p. 38; and J. C. Branner, Ann. Kept. Arkan-

 sas Geol. Survey, vol. 5,1892, pp. 9-34. Both authors give analyses, and other analyses by T. M. Chatard 

arid H. N. Stokes can be found in Bull. U. S. Geol. Survey No. 228,1904, pp. 361, 362. A similar clay from 

Bertha, Virginia, with 12.1 per cent ZnO, was described by B. H. Heyward, Chem. News, vol. 44,1881, p. 

207. 

a Mon. U. S. Geol. Survey, vol. 12,1886, p. 603.
682 DATA OF GEOCHEMISTRY.

deposited from solution, which is the essential fact for the geochemist 

to .consider. 1

The zinc mines at Franklin and Sterling Hill, New Jersey, are of 

a different type from those of the Mississippi Valley, being indeed 

Unique. Here zincite, franklinite, and willemite, ores which are rare 

minerals elsewhere, are most abundant, while blende is present only 

in insignificant quantities. The ore bodies occur in crystalline limestone, in contact with gneiss, and the limestone is pierced by numerous granitic dikes. It seems probable, from the character of the ores 

and their mineralogical associations, that they were formed by contact metamorphism. A bed of limestone containing calamine and 

smithsonite, together with other impurities, might be expected to 

change, by thermal metamorphosis, into just such a formation as that 

at Franklin. The smithsonite would yield zincite, the willemite 

might be formed from calamine, and the franklinite and gahnite, with 

other spinels, could develop exactly as members of the spinel group 

develop in ordinary limestones. This hypothesis needs verification, 

but it is plausible and simple. In southwestern New Mexico, according to W. P. Blake, 3 zinc ores occur in a contact-metamorphosed 

limestone; but blende is the principal mineral. Blake, however, is 

inclined to correlate this deposit with that at Franklin, notwithstanding their differences. 3

1 For data concerning these deposits, see J. D. Whitney,-Rept. Geol. Survey Wisconsin, vol. 1, chapter 6, 

1862; T. C. Chamberlin, Geology of Wisconsin, vol. 4, 1882, pp. 367-553; W. P. Blake, Bull. Geol. Soc. 

America, vol. 5,1893, p. 25; U. S. Grant, Bull. Wisconsin Geol. Nat. Hist. Survey No. 9, 1903, and Bull. 

U. S. Geol. Survey No. 260,1905, p. 305; E. E. Ellis, idem, p. 310; A. G. Leonard, Iowa Geol. Survey, vol. 

6,1897, pp. 13-65; and Am. Geologist, vol. 16, 1905,'p. 288; H. F. Bain, Bull. U. S. Geol. Survey No. 225, 

1904, p. 202; A. Winslow, Missouri Geol. Survey, vols. 6 and 7,1894, and Jour. Geology, vol. 1,1893, p. 612; 

J. D. Robertson, Am. Geologist, vol. 15, 1895, p. 235; Bain, Van Hise, and Adams, Twenty-second Ann. 

Kept. U. S. Geol. Survey, pt. 2,1902, p. 23; W. P. Jenney, Trans. Am. Inst. Min. Eng., vol. 22,1894, pp. 

171,642; E. Hedburg, idem, vol. 31,1901, p. 379; J. C. Branner, Ann. Kept. Arkansas Geol. Survey, vol. 5, 

1892, and Trans. Am. Inst. Min. Eng., vol. 31,1901, p. 572; G. I. Adams, idem, vol. 34,1904, p. 163; Bull. 

U. S. Geol. Survey No. 213,1903, p. 187, and Prof. Paper U. S. Geol. Survey No. 24,1904; W. S. T. Smith, 

Bull. U. S. Geol. Survey No. 213,1903, p. 196, and A. Keith, Bull. U. S. Geol. Survey No. 225,1904, p, 208. 

. See also W. H. Case, Trans. Am. Inst. Min. Eng., vol. 22,1894, p. 511, on the zinc ores of Bertha, Virginia. 

S. F. Emmons (Trans. Am. Inst. Min. Eng., vol. 22,1894, p. 83) briefly discusses the origin of zinc ores, 

and so too does C. R. Van Hise in his Treatise on' metamorphism, Mon. U. S. Geol. Survey, vol. 47,1904, 

pp. 1125-1158. A zinc deposit in Nevada is described by Bain, Bull. U. S. Geol. Survey No. 285, 1906, 

p. 166. Other publications are by E. Haworth and others, Kansas Univ. Geol. Survey, vol. 8,1904; E. R. 

Buckley and H. A. Buehler, Missouri Bur. Geology and Mines, 2d ser., vol. 4,1906, and Buckley, idem, 

vol. 9, pt. 1,1908; H. F. Bain, Bull. U. S. Geol. Survey No. 294, 1907; T. L. Watson, Bull. Am. Inst. 

Min. Eng., March, 1906. 'See also Bain, Bull. Wisconsin Geol. Nat. Hist. Survey No. 19,1907; L. C. Snider. 

Oklahoma Geol. Survey, Bull. No. 9,1912; G. H. Cox, Econ. Geology, vol. 6,1911, p. 427. On the genesis 

of the Ozark deposits, see C. R. Keyes, Bull. Am. Inst. Min. Eng., 1909, p. 119; .Bull. U. S. Geol. Survey 

No. 606,1915, by C. E. Siebenthal, is an exhaustive treatise on the lead and zinc ores of .Toplin and the' 

adjacent regions.

* Trans. Am. Inst. Min. Eng., vol. 24,1895, p. 187.

8 For data regarding the Franklin region, see F. L. Nason, Arm. Kept. State Geologist New Jersey, 1890, 

p. 25; and J. F. Kemp, Trans. New York Acad. Sci., vol. 13,1893, p. 76. Kemp gives references to earlier 

literature. See also J. E. Wolff, Bull. U. S. Geol. Survey No. 213, 1903, p. 214, and A. C. Spencer, Ann. 

Kept. State Geologist New Jersey, 1908, and Geol. Atlas U. S., U. S. Geol. Survey, Franklin Furnace 

folio (No. 161), 1908. On the zinc ores of St. Lawrence County, New York, see Bull New York State Mus. 

No. 201, 1918.
> METALLIC OBE'S. 683

LEAD.

Although lead is one of the commoner heavy metals, native lead is 

exceedingly rare. It is known, however, from several localities, but 

^ it is always of secondary origin,, a product of reduction. 1

The principal ore of lead is the normal sulphide, galena, PbS. 

Allied to this are the rare selenide, clausthalite, and altaite, the corresponding telluride.2 The synthetic preparation of galena has been 

', effected by various methods, both wet and dry. J. Durocher 3 

' obtained it by the action of hydrogen sulphide upon lead chloride at a 

red heat. Any other salt of lead would probably serve the same 

purpose. Even the silicate of lead contained in glass, according toT. Sidot,4 when heated in the vapor of sulphur, yields galena. F. 

Stolba 5 produced crystals of the sulphide by heating the amorphous 

compound to dull redness with chalk. F. de Marigny 6 produced 

galena by fusing litharge with iron pyrites and starch. F. Roessler 7 

crystallized both galena and clausthalite from solution in molten 

** lead. By distillation of a mixture containing lead oxide, sulphur, 

/ and ammonium chloride, E. Weinschenk 8 also prepared crystals of 

galena. It is furthermore to be noted that galena is not uncommon 

in furnace slags, and that Mayencon 9 has reported its formation as 

a product of sublimation in a burning coal mine.

The foregoing syntheses of galena have small geological significance. In nature, the mineral appears to be commonly formed by 

i.. hydrochemical reactions, and these can be imitated in the laboratory. 

C. Doelter 1Q allowed lead chloride, sodium bicarbonate, and a solution 

of hydrogen sulphide in water to remain in a sealed tube at ordinary 

room temperature during five months. Crystals of galena were thus 

formed. E. Weinschenk " heated a solution of lead nitrate with 

* ammonium sulphydrate to 180° in a sealed tube and also obtained 

s^_* galena. H. N. Stokes 12 has found that pyrite or marcasite, heated 

with a solution of lead chloride to 180°, will precipitate lead sulphide. A. Daubre"e 13 observed the formation of galena, together with

1 A. Hambcrg (Zcitschr. Kryst. Min., vol. 17, 1890, p. 253) has suggested that at Harstig, Sweden, the 

,i lead was reduced by arsenious oxide.

2 Nagyagitc is a sulphotclluridc of lead, gold, and antimony. Naumannitc, lehrbachite, and zorgitc are 

seleiiides of lead with silver, mercury, or copper.

3 Compt. Rend., vol. 32,1851, p. 825. See also A. Carnot, cited by L. Bourgeois, Reproduction artilicielle 

cles mindraux, p. 30.

4 Compt. Rend., vol. 62,1806, p. 999.

5 Jahresb. Chorale, 1863, p. 242.

9 Compt. Rend., vol. 58,1864, p. 967.

7 Zeitschr, anorg. Chemie, vol. 9, 1895, p. 41. By passing selenium vapor over-melted lead G. Little 

(Liebig's Annalen, vol. 112, 1859, p. 211) also produced the selenide.

8 Zeitschr. Kryst. Min., vol. 17,1890, p. 489. 

' ? Compt. Rend., vol. 86,1878, p. 491.

^ .»o Zeitschr. Kryst. Min., vol. 11,1886, p. 41. A. C. Becqucrel (Compt. Rend., vol. 44,1857, p. 938) mentions a hydrochomical synthesis of galena, but too vaguely to warrant citation above.

» Zeitschr. Kryst. Min., vol. 17,1890, p. 497.

12 Econ. Geology, vol. 2,1907, p. 22.

" Etudes synihe'tiques de ggologie expe"rimentale, pp. 84,85.
684 DATA OF GEOCHEMISTRY.

a,nglesite and phosgenite, by the action of < the thermal waters of 

Bourbonne-les-Bains on metallic lead. Lead sulphide is also known 

in spring deposits, 1 and as a pseudomorphous replacement of other 

/ minerals. W. Lindgren 2 mentions replacements of calcite, dolomite, 

 and quartz, and also of orthoclase and rhodonite. W. H. Hobbs 3 

has described secondary galena as a surface film on cerusite, formed 

probably by the action of hydrogen sulphide on the latter mineral. 

That galena itself is slightly soluble in water and also in solutions of 

sodium sulphide has been shown by C. Doelter. 4 A. Gautier 5 has 

shown that galena is dissociated into its elements by the action of 

steam at a red heat. A little galena volatilizes and is redeposited in 

crystalline form, and some also is converted into sulphate. The presence of galena among the Vesuvian sublimates, mentioned in an 

earlier chapter of this volume, may be correlated with Gautier's 

observations.

The sulphosalts of lead are numerous, although, on account of 

their individual rarity, they have little significance as ores. 6 Sartorite, dufrenoysite, guitermanite, jordanite, rathite, and lengenbachite 

are sulpharsenides. Zinkenite, plagionite, jamesonite, semseyite, 

boulangerite, meneghinite, geocronite, kilbrickenite, and epiboulangerite are sulphantimonides. Other sulphantimonides of lead and 

silver are brongniardite, diaphorite, freieslebenite, and andorite. 

The sulphobismuthides are chiviatite, rezbanyite, galenobismutite, 

schirmerite, cosalite, schapbachite, kobellite, lillianite;, and beegerite. 

Teallite, cylindrite, and franckeite are sulphostannides, which, for 

present purposes, must be classified under tin.

According to J. Fournet, 7 zinkenite, PbSb2S4 , can be prepared by 

fusing galena and sfcibnite together in proper proportions. C. Doelter, 8 by heating antimony, antimony trioxide, and lead chloride 

together in gaseous hydrogen sulphide, obtained jamesonite, PbSb2S5 , 

mixed with stibnite and galena. By the action of molten lead chloride upon antimony trisulphide, H. Sommerlad 9 reproduced boulangerite, Pb3Sb2S6 ; zinkenite; jamesonite; warrenite 10 (domingite),

1 See, for example, the sinter described by G. F. Becker and W. H. Melville, Mon. U. S. Geol. Survey, 

vol. 13, 1888, p. 344.

2 Trans. Am. Inst. Min. Eng., vol. 30,1900, p. 578. 

Am. Jour. Sci., 3d ser., vol. 50,1895, p. 121.

Min. pet. Mitt., vol. 11,1890, p. 319. An iron wedge or chisel coated with galena is mentioned in Mineralog. Mag., vol. 16,1913, p. 340.

» Compt. Rend., vol. 142,1906, p. 1465.

 Bournonite and aikinite, which contain both lead and copper, have already been mentioned under the 

latter metal.

7 Cited by L. Bourgeois, Reproduction artificielle des mine'raux, p. 46, from Jour, prakt. Chemie, vol. 2, 

p. 490.

"Zeitschr. Kryst. Min., vol. 11, 1886, p. 40.

9 Zeitschr. anorg. Chemie, vol. 18, 1898, p. 420. Sommerlad's results have been called in question by 

F. Ducatte (Thesis, Univ. Paris, 1902) and J. Rondet (Thesis, Univ. Paris, 1904), who claim that the reactions employed really produce complex chlorinated sulphides, and not true sulphosalts.

i» According to L. J. Spencer (Mineralog. Mag., vol. 14, 1907, p. 207), warrenite is identical with jamesonite. W. T. Schaller (Zeitschr, Kryst. Min., vol. 48,1911, p. 562) regards it as a mixture of jamesonite and 

zinkenite.
 METALLIC ORES. 685

Pb3Sb4S8 ; and plagionite, Pb5Sb8S17 . By fusing lead sulphide and 

arsenic trisulphide together, he obtained sartorite (scleroclase), 

PbAs2S4, and dufrenoysite, Pb2As2S5 .

G. Pelabon,1 studying the fusion curve of the system PbS + Sb2S3 , 

found that zinkenite crystallized out at 558? , and jamesonite at 

610°. F. M. Jaeger and H. S. van Klooster,2 by a similar process, 

obtained only jamesonite and plagionite. The component sulphides 

were fused together in an atmosphere of nitrogen. They assert that 

Sommerlad's syntheses are incorrect.

.Whether any of these syntheses correspand to natural processes is 

questionable. The ore bodies in which the minerals occur appear to 

have been formed in most cases from mineralized solutions, or else 

by pneumatolytic reactions at temperatures which were not excessively high. Syntheses, to be geologically significant, should be conducted on the lines which nature seems to have followed.3

By oxidation, carbonation, etc., the sulphur compounds of lead are 

transformed into other minerals. Among them are the three oxides, 

massicot, PbO; minium, Pb304 ; and plattnerite, Pb02 . All these 

have been prepared synthetically in crystalline form, but in most 

cases by methods which scarcely resemble natural processes. A. C. 

Becquerel,4 by allowing an alkaline solution of alumina or silica to act 

slowly .upon a plate of lead, obtained crystals of massicot. The lead 

was surrounded by a coil of copper wire, and Becquerel attributed the 

synthesis to electrical action. It was more probably a simple hydrochemical process.

Lead carbonate, cerusite, PbC03 , is a common mineral, produced 

by the action of carbonated waters in the upper levels of ore bodies.5 

There are also the basic hydrocerusite, Pb3 (OH) 2 (CO3 ) 2 , and the rare 

dundasite, a carbonate of aluminum and lead.6 Becquerel 7 obtained 

crystals of cerusite when a solution of sodium and calcium carbonate 

acted gradually upon a plate of lead. E. Fremy 8 produced the 

mineral by the slow diffusion of a carbonate solution into a lead 

solution through a porous membrane. By some such gradual mingling of dilute solutions, the natural cerusite is probably often formed. 9

1 Compt. Rend., vol. 156, p. 706,1913.

2 Zeitschr. anorg. Chemic, vol. 78, p. 245, 1912.

" Jamesonite forms an important ore at La Sirena, near Zimapan, Mexico. See W. Lindgren and AV. L. 

AVhitehead, Econ. Geology, vol. 9, 1914, p. 435.

4 Compt. Rend., vol. 34,1852, p. 29. See also, for other researches, L. Bourgeois, Reproduction artificielle 

des min6raux, p. 56. L. Michel (Bull. Soc. mtn., vol. 13, 1890, p. 56) reports syntheses of minium and 

plattnerite.

5 A largo deposit of cerusite in the Terrible mine, at Use, Colorado, has been described by R. B. Brinsmade, Eng. and Min. Jour., vol. 83, 1907, p. 844. Its formation is ascribed to the action of descending 

waters.

« See G. T. Prior, Mineralog. Mag., vol. 14, 1906, p. 167.

7 Loc. cit.

8 Compt. Rend., vol. 63,1866, p. 714.

9 The syntheses of cerusite, by J. Riban (Compt. Rend., vol. 93,1881, p. 1026), and of hydrocerusite, by 

L: Bourgeois (Bull. Soc. min., vol. 11, 1888, p. 221), have no relation to natural processes.
686 DATA OF GEOCHEMISTRY.

H. von Dechen l has reported the case of an. old mine whose walls were 

covered with a thick coating of cerusite, which had been deposited 

from solution like sinter. A. Lacroix 2 has observed the mineral as 

a coating on old Roman coins. It is also produced by metasomatic 

replacement in limestones, and fossils, such as encrinites; have been 

found completely transformed into cerusite.3 The rare chlorocarbonate of lead, phosgenite, Pb2Cl2C03 , was reproduced by C. 

Friedel and E. Sarasin; 4 when lead chloride, lead carbonate, and 

water were heated together in a sealed tube to 180°. It was also 

prepared by A. de Schulten,5 who allowed a filtered solution of lead 

chloride to stand in a large flask while a current of carbon dioxide 

passed slowly through the vacant space above.

Cotunnitej lead chlorite, PbCl2 , is found in nature as a volcanic 

mineral, produced by sublimation. F. Stober 6 reproduced the mineral by this process, and also obtained it in minute crystals from 

simple solution in water or in aqueous hydrochloric acid.. It was also 

formed by A. C. Becquerel,7 much earlier, by allowing a solution of 

copper sulphate and sodium chloride to act upon galena during a 

period of seven years. The sulphate, anglesite, was obtained at the 

same time. The great rarity of cotunnite as a natural mineral is due 

to the strong tendency on the part of lead to form basic salts, and the 

basic chlorides are much more frequently found. Matlockite, Pb2OCl2 , 

and mendipite, Pb3 02Cl2 , have long been known. Schwartzembergite 

is like mendipite in composition, but with iodine largely replacing 

chlorine. Laurionite,8 paralaurionite, penfieldite, daviesite, and fiedlerite are oxychlorides of lead which have formed on ancient slags at 

Laurium, in Greece. Caracolite is a double salt of the composition 

PbOHCl + Na2S04 . Percylite, cumengeite, and pseudoboleite are 

oxychlorides of lead and copper, and boleite is similar in composition, 

but with silver chloride as an additional component.9

Lead sulphate, PbS04 , as the crystallized mineral anglesite, is a 

common oxidation derivative of galena. According to E. Jannetaz. 10 

galena is easily attacked by acid solutions of ferrous sulphate such as 

are generated by the oxidation of pyrite or marcasite. * The associaiNeuesJahrb.,1858, p. 216. .

»Bull. Soc. min., vol. 6,1883, p. 175.

s See Blode, Neues Jahrb., 1834, p. 638'.

< Bull. Soc. min., vol. 4,1881, p. 175.

B Idem, vol. 20,1897, p. 194.

6 Bull. Acad. roy. sci. Belgique, 3d ser., vol. 30,1895, p. 345.

' Compt. Rend., vol. 34, 1852, p. 29.

8 For a synthesis of laurionite, P,bOHCl, see A. de Schulten, Bull. Soc. min., vol. 20,1897, p. 186. On the 

rare minerals of Laurium, see A. Lacroix and De Schulten, Bull. Soc. min., vol. 31,1908, p. 79. Georgiadesite, 

a phosphate and chloride of lead, should be added to the list.

9 Percylite, cumengeite, and boleite have been made artificially by C. Friedel, Bull. Soc. min., vol. 15, 

1892, p. 96; 1893, p. 187; and vol. 17, 1894, p. 6. See also, in reference to these minerals, E. Mallard, Bull. 

Soc. min., vol. 16, 1893, p. 187; and G. Friedel, idem, vol. 29,1906, p. 14.

10 Bull. Soc. geol. France, 3d ser., vol. 3,1875, p. 310. G. Piolti (Jour. Chem. Soc., vol. 100, 1911, p. 902, 

abstract) obtained crystals of anglesite by the prolonged immersion of galena in a solution of potassium 

nitrate.
METALLIC ORES. 687

tion of galena with pyrite, therefore, is favorable to the formation 

of anglesite. Its synthasis by Beoquerel has already been mentioned, 

and it has also been prepared by Mace" / who added a solution of ferrous sulphate very slowly to one of lead nitrate. Essentially the 

same, process was successfully followed by E. Fremy 2 and by E. 

Masing,3 a soluble sulphate being allowed to diffuse very slowly into 

one of a lead salt in Masing's case lead nitrate. Lead sulphate, 

although relatively insoluble, is not absolutely so; it therefore can 

be crystallized, as the syntheses show, when it is formed with extreme 

slowness in very dilute solutions. Conditions of this sort probably 

attend the formation of anglesite in bodies of lead ore; but when carbonates are present in the percolating waters, cerusite is produced 

instead. The synthesis of anglesite by N. S. Manross, 4 who obtained 

it by fusing lead chloride with potassium sulphate, does not seem to 

correspond °with any natural mode of formation.

Lanarkite is a rare, basic sulphate of lead, Pb2SO5 .5 Caledonite 

and linarite are basic sulphates of lead and copper, and plumbojarosite and beaverite basic sulphates of lead and ferric iron. Leadhillite 

is a complex salt of the formula PbS04 .2PbC03 .Pb (OH) 2 . At Granby, 

Missouri, according to W. M. Foote, 8 it occurs as a pseudomorph 

after calcite and galena. In composition it suggests a double salt 

formed by the union of hydrocerusite and anglesite, in equimolecular 

proportions.7 Plumbojarosite, a highly hydrated sulphate of lead 

and iron, is abundant in some mines in Utah.8

Lead salts analogous to angelsite are the chromate, crocoite, 

PbCr04 ; the molybdate, wulfenite, PbMo04 ; and the tungstate, stolzite, PbWO4 . The rare phoenicochrorte 9 is a basic chromate, 

Pb3Gr2 09 ; vauquelinite is a chromate and phosphate, and beresovite 

is described as a chromate and carbonate of lead, which is not, however, the equivalent of leadhillite, for it contains no water.

When sodium tungstate is fused with lead chloride, according to 

N..S. Manross, 10 stolzite is formed; with sodium molybdate, wulfenite 

is {produced; and by fusing together potassium chromate and lead 

chloride he obtained crocoite. The formation of wulfenite as a 

furnace product 11 is probably due to some reaction of this kind..

1 Compt. Rend., vol. 36,18.53, p. 855. 

«Idem, vol. 63,1806, p. 714. 

8 Jahresb. Chemie, 1889, p. 4.

* Liebig's Annalen, vol. 82,1852, p. 348;

* For a synthesis of lanarkite, see A. de Schulten, Bull. Soc. min., vol. 21,1898, p. 142. 

« Am. Jour. Sci., 3d ser., vol. 50, 1895, p. 99.

* Palmicrile, a double sulphate of load and potassium, is found among the recent products of fumnrole 

action at \7esuvius.

8 In certain of the mines of Beaver County, plumbojarosite is abundant enough to be treated as an ore 

of lead. See B. S. Butler, Econ. Geology, vol. 8, 1913, p. 311.

'° Also'called melanochroite.

w Liebig's Annalen, vol. 82, 1852, p. 348. H. Schultzo (idem, vol. 120, 1863, p. 51) prepared wulfenito in 

the same way.

» See-J. F. L. Hausmann, idem, vol. 81, 1852, p. 224.
688 DATA OF GEOCHEMISTRY.

By slow diffusion of solutions of potassium chromate and lead nitrate 

into one another A. Drevermarin 1 obtained both crocoite and phoenicochroite. Cerasite and anlgesite were formed at the same time 

from impurities in the reagents. A. C. Becquerel 2 allowed a galvanic couple of lead and platinum to act for several years upon a 

solution of chromic chloride and obtained crystals which appeared 

to be crocoite. S. Meunier 3 found that phoenicochroite was formed 

when fragments of galena were immersed during six months in a solution of potassium dichromate. L. Bourgeois 4 boiled precipitated 

lead chromate with dilute nitric acid. From the hot, filtered solution ciystals of crocoite were deposited. Better results were obtained 

when the operation was conducted in a sealed tube at 130°. Lachaud 

and Lepierre 5 state that when amorphous lead chromate is boiled 

with a solution of chromic acid it crystallizes into crocoite. Phoenicochroite was formed when lead chromate and sodium chloride were 

fused together. Both chromates were obtained by Ltideking 6 upon 

exposing to the air during several months a solution of lead chromate 

in caustic potash. G. Cesaro 7 prepared crocoite by the same process, 

and with lead molybdate crystalline wulfenite was formed. E. 

Dittler 8 added a hot, concentrated solution of lead chloride to a 

dilute sulutioii of ammonium molybdate, and obtained an amorphous precipitate. This, dissolved in a solution of sodium carbonate, 

was gradually redeposited as wulfenite. Natural wulfenite, digested 

with sodium bicarbonate, yielded hydrocerusite. Of all these syntheses, that by Meunier seems best to represent the probable natural 

processes.

Three lead minerals, the chlorophosphate, pyromorphite, Pb5P3012Cl; 

the corresponding arsenate, mimetite, Pb5As3O12Cl; and the vanadium salt, vanadinite, Pb5V3012Cl, occur both independently and in

great variety of isomorphous mixtures. Endlichite, for example, is 

a mixture of the arsenic and vanadium compounds, and minerals 

intermediate between mimetite and pyromorphite are common. 

All these species have been prepared synthetically, and pyromorphite is also known as a furnace product in slag.9 N. S. Manross 10 

obtained pyromorphite by fusing lead chloride with tribasic sodium 

phosphate. H. Sainte-Claire Deville and H. Caron n fused lead phosphate, lead chloride, and sodium chloride together to produce pyromorphite, and L. Michel 12 accomplished the same purpose by the 

same process, only omitting the common salt. From fusions of lead 

arsenate with lead chloride G. Lechartier 13 and also Michel succeeded

1 Liebig's Annalen, vol. 87, 1853, p. 120; vol. 89, ' Bull. Acad. roy. sci. Belgique, 1905, p. 327.

1854, p. 11. 8 Zeitschr. Kryst. Min., vol. 53,1914, p. 158.

2 Compt. Rend., vol. 63,1866, p. 1. 9 J. J. Noggerath, Neues Jahrb., 1847, p. 37.

8 Idem, vol. 87,1878, p. 656. 10 Liebig's Annalen, vol. 82,1852, p. 348.

« Bull. Soc. min., vol. 10,1887, p. 187. ll Annales chim. phys., 3d ser., vol. 67,1863,'d 451.

6 Bull. Soc. chim., 3d ser., vol. 6,1891, p. 230. 12 Bull. Soc. min., vol. 10,18S7, p. 133.

s Am. Jour. Sci., 3d ser., vol. 44, p. 57. 13 Compt. Rend., vol. 65,18G7, p. 172.
METALLIC ORES. 689

in reproducing mimetite. Vanadinite was obtained by P. Hautefeuille 1 when vanadic oxide was fused with lead oxide and lead 

chloride. All of these syntheses, it will be seen, are similar and were 

effected by fusion, while the natural occurrences of the minerals indicate hydrochemical reactions. In the case of pyromorphite this 

natural process was simulated by H. Debray,2 who prepared pyromorphite by digesting lead pyrophosphate with a solution of lead 

chloride at 250°.

Other phosphates, arsenates, and vanadates containing lead and 

sometimes zinc, iron, or copper also, are plumbogummite, caryinite, 

carminite, lossenite, bayldonite, ecdemite, beudantite,3 svanbergite, 

hinsdalite, descloizite, cuprodescloizite, brackebuschite, and psittacinite. Bindheimite is a lead antimonate, formed by oxidation from 

sulphosalts of lead. Nadorite, PbClSb02 , and ochrolite, Pb6Cl2Sb207 , 

are perhaps of similar origin. All of these species are rare minerals 

and need not be considered further. The same may be said of the 

lead-bearing silicates, barysilite, ganomalite, hyalotekite, kentrolite, 

melanotekite, nasonite, roeblingite> and molybdophyllite. The 

roehlingite, however, from the zinc mines at. Franklin, New Jersey, 

is unique in containing a sulphite molecule combined with the silicate. 

An artificial lead silicate from furnace slag has been described by 

E. S. Dana and S. L. Penfield, 4 and also by H. A. Wheeler.5 -

The common association of lead ores with those of zinc was pointed 

out in the preceding section of this chapter. Blende and galena are 

both formed from solutions, but not always in the same manner. By 

differences in the solubility of their oxidation products the two 

metals are often separated from each other, for lead sulphate is 

slightly soluble, while zinc sulphate is easily so. Zinc, therefore, 

disappears from the upper portions of ore bodies much more rapidly 

than lead, and, for the same reason, so does copper. The lead ores 

of Eureka, Nevada, are regarded by J. S. Curtis 6 as the product of 

solfataric action; those of Leadville, Colorado, according to S. F. 

Emmons,7 were deposited from descending solutions, which had gathered their metallic burden from neighboring eruptive rocks. In both 

cases the ore bodies are interpreted as replacements in country rock.

1 Compt. Rend., vol. 77,1873, p. 896.

2 Annales chim. phys., 3d ser., vol. 61, 1861, p. 443. Recent syntheses of pyromorphite, mimetite, and 

vanadinite are by J. R. Mourelo, Rev. ge"n. sci., vol. 26,1915, p. 394; of mimetite by C. C. McDonncll and 

C. M. Smith, Am. Jour. Sci., 4th ser., vol. 42,1916, p. 139. These syntheses do not seem to parallel natural 

occurrences.

3 Phosphate, arsenate, and sulphate of lead. Svanbergite, hinsdalite, and the sulphate, beaverite, are 

allied to beudantite.

* Am. Jour. Sci., 3d ser., vol. 30,1885, p. 138. 

»Idem, vol. 32,1886, p. 272.

6 Mon. U. S. Geol. Survey, vol. 7,1884, chapters 7,8. 

' Idem, vol. 12,1886, p. 378.

113750° 19 Bull. 695 44
690 . DATA OF GEOCHEMISTRY.

TIN. 1

Tin is one of the rarer metals and its ores are not numerous. 

Native tin is occasionally found, but never in more than trifling quantities and in small grains.2 The ore of chief importance is the 

dioxide, cassiterite, SnO2 , but several sulphosalts are also known. 

They are

Stannite. ...........................'.............. .Cu2FeSnS4 .

Teallite3 .............................................PbSnS2 .

Cylindrite. .........................................Pb3FeSn4Sb2S14 .

Franckeite........................................... .Pb5FeSn3Sb2S 14 .

There is also a very rare borate of calcium and tin, nordenskioldine, 4 CaSnB206, which is interesting because it directly connects tin 

with boron. .The same is true of hulsite and paigeite, two iron-tin 

borates found in Alaska.5 Other minerals, especially those of the 

rare earths, sometimes contain small amounts of tin as an impurity, 

and the metal has also been found in zinc blende.6 

. Cassiterite has been repeatedly observed as a furnace product 

formed by the direct oxidation of tin. Recent occurrences of this 

kind are recorded by A. Arzruni 7 and J. H. L. Vogt,8 and L. Bourgeois 9 has identified the mineral in scoria from a bronze foundry. 

The first synthesis of cassiterite was performed by A. Daubree 10 when 

the vapor of stannic chloride was mixed with steam in a red-hot 

porcelain tube. Later the same chemist u prepared the mineral by 

passing the vapor of stannic chloride over heated lime. The crystallized oxide was obtained by H. Sainte-Claire Deville and H. Caron12 

when stannic fluoride and boric oxide were heated together to whiteness. H. Sainte-Claire Deville 13 also obtained it by heating the 

amorphous oxide in a slow current of hydrochloric acid gas and

1 For a paper on the occurrence and distribution of tin, with a bibliography, see F. L. Hessand L. C. 

Graton, Bull. U. S. Geol. Survey No. 260,1904, p. 160. A summary of tin localities is also given by W. P. 

Blake, in Mineral Resources U. S. for 1883-84, U. S. Geol. Survey, 1885, pp. 592 et seq.

2 A recent disco very of native tin is noted by E. S. Simpson in Ann. Kept'. Geol. Survey West Australia, 

1899, p. 52.

3 See G. T. Prior, Mineralog. Mag., vol. 14, 1904, p. 21, on the composition of teallite, cylindrite, and 

franckeite. See also A. Stelzner, Neues Jahrb., Band 2, 1893, p. 114, and A. Frenzel, idem, p. 125. On 

stannite and its alteration products from the Black Hills, see W. P. Headden. Am. Jour. Sci., 3d ser., 

.vol. 45,1893, p. 105.

* Described by W. C. Brogger, Zeitschr. Kryst. Min., vol. 16,1809, p. 61.

s See A. Knopf and W. T. Schaller, Am. Jour. Sci., 4t.h sec., vol. 25,1908, p. 323. Also Schaller, idem, 

vol. 29, 1910, p. 543.

6 See A. Stelzner and A. Schertel, Jahrb. Berg- u. Hiittcnw. Kb'nig. Sachsen, 1886, p. 52, on tin in black 

blende from Freiberg. It has also been found in the zinc ores of the Slocan district, British Columbia. 

See Rept. Comm. on Zinc Resources, etc., of British Columbia, Mines Branch, Dept. Interior, Ottawa, 

1906, p. 15.

7 Zeitschr. Kryst. Min., vol. 25, 1896, p. 467. .

s Idem, vol. 31,1899, p. 279.

» Bull. Soc. min., vol. 11, 1888, p. 58. 

10 Compt. Rend., vol. 29, 1849, p. 227. 

" Idem, vol. 39, 1854, p. 135. 

ls:Idem, vol. 46, 1858, p. 764. Details not given. 

u Idem, vol. 53, 1861, p. 161.
METALLIC ORES. 691

again by a repetition of DaubreVs first process. A. Ditte 1 noticed 

the formation of crystalline stannic oxide when the amorphous compound, mixed with calcium chloride and ammonium chloride, was 

subjected to a white heat.

According to C. Doelter,2 cassiterite is perceptibly soluble in water 

at 80°, and more so in presence of sodium fluoride. Some recrystallization from the solution was observed. This solubility is also 

indicated by several natural occurrences of tin. S. Meunier 3 found 

0.5 per cent of Sn02 in an opaline deposit, resembling geyserite, from 

a thermal spring in Selangor. J. H. Collins 4 reports tinstone as a 

cement in certain Cornish conglomerates, as an impregnation in longburied horns of deer, as pseudomorphs after feldspar,5 and as cappings on crystals of quartz. He also notes that cassiterite crystals 

often line fissures in quartz, the latter containing numerous fluid 

inclusions. An incrustation resembling "wood tin" was found by 

Collins on an ingot of ancient tin, having been formed by slow oxidation of the metal. Furthermore, Collins reports secondary crystallizations of cassiterite on reniform masses of "wood tin," and all of 

this evidence he regards as proof that the Cornish ores are of aqueous 

origin. Pseudomorphs of cassiterite after hematite were found by 

F. A. Genth 6 in tin ores from Durango, Mexico, and he also cites 

an observation by W. Semmons, who described specimens of bismuthinite coated with concentric layers of tinstone. It is possible 

in some of these cases that the tin-bearing solutions may have been 

derived from the oxidation of stannite, but this point seems to have 

received little or no consideration. Stalactitic cassiterite, from the 

Sierra de Guanajuato, Mexico, has been described by E. Wittich.7

Cassiterite has been noted as an original constituent of igneous 

rocks, 8 but it more commonly occurs in veins or stringers of quartz 

under conditions which indicate a secondary deposition. As a rule, 

tin-bearing veins are found in or near persilicic rocks, such as pegmatites and altered granites. Sometimes the association is with quartz 

porphyry, as at Mount Bischoff, in Tasmania, 9 and at certain Mexican 

mines; but at other localities of tin in Mexico the prevailing rock is

» Compt. Rend., vol. 96,1883, p. 701.

2 Mil. pet. Mitt., vol. 11, 1890, p. 325.

3 Compt. Rend., vol. 110,1890, p. 1083.

« Mineralog. Mag., vol. 4,1880, pp. 1,103, and vol. 5,1883, p. 121.

s According to C. Reid and J. B. Scrivenor (Mem. Geol. Survey Eng. and Wales, Geology of country 

near Newquay, 1906, p. 39), the so-called pseudomorphs are replacement of orthoclase by an aggregate of 

cassiterite, muscovite, and quartz. On the genesis of the Cornish ores, see also J. B. Hill and D. A. MacAJister, idem, Geology of Falmouth, Truro, etc., p. 167.

8 proc. Am. Philos. Soc., vol. 24,1887, p. 23. L. V. Pirsson (Am. Jour. Sci., 3d ser., vol. 42, 1891, p. 407) 

has described crystals of hematite inclosing cassiterite, from the same locality.

7 Zeitschr. prakt. Geologic, 1910, p. 121.

8 See ante, p. 348, in chapter on rock-forming minerals.

"On Tasmanian tin deposits see L. K. Ward, Bull. Geol. Survey Tasmania, No. 6,1909. Earlier separate 

papers by G. A. Waller and W. H. Twelvetrees were issued by the same office. On the Mount Bischoff 

mines, see W. von Fircks, Zeitschr. Deutsch. geol. Gesell., vol. 51, p. 431.
DATA OF GEOCHEMISTRY.

rhyolite or rhyolite tuff. In these instances, as at the Potrillos mine, 

in Durango, the ore is found along fault planes in the rhyolite.1 

The Cacaria mine, also in Durango, is in quartz porphyry. In the 

Malay Peninsula, according to R. A. F. Penrose,2 the prevalent 

stanniferous rocks are granite, or detrital matter derived from 

granite; but at Chongkat Pari, in Perak, cassiterite is extracted 

from limestone, and at Bruseh, Perak, it is found in seams in sandstone. These abnormal occurrences are perhaps due, as Penrose 

suggests, to infiltration of tin-bearing solutions a supposition 

which becomes probable in the light of evidence already cited. In 

Lander County, Nevada, according to A. Knopf,3 wood tin occurs in 

thin veins in rhyolite, associated with opal and tridymite. This 

association suggests a deposition from hot solutions.

The typical mode of occurrence of tin ores is in quartz veins cutting granite, the walls of the latter rock being altered into greisen. 

Greisen is essentially a granite in which the feldspars have been 

transformed into mica and of which topaz and tourmaline are frequent constituents. The mica is often, but not invariably, lithia 

bearing, either ordinary lepidolite or zinnwaldite. Bismuth ores, 

wolfram, and arsenopyrite are common associates of the tinstone.

These mineralogical data, the usual presence in stanniferous veins 

of species containing fluorine and boron, and also the alteration of the 

granite walls, have led to the very general belief that tin deposits of 

the ordinary type have been formed by the injection of vapors carrying the two elements above named and also the tin. This belief is 

strengthened by the various syntheses of cassiterite, in which boric 

oxide and chloride or fluoride of tin have taken part. The significance of the very rare mineral nordenskioldine, with its tin and boron 

together, here becomes apparent, although the species has not been 

found in any vein or deposit of the usual stanniferous type, but only 

hi a dike of elaeolite syenite. Ordinarily the two elements are separated, the boron going to the tourmaline molecules and the tin to 

form cassiterite. Fluorine is represented by topaz, fluorite, or apatite, and some tunes by the lithia-bearing phosphates triphylite and 

amblygonite.4 In some localities formerly worked for tin the lithia

i See 0. W. Kempton, Trans. Am. Inst. Min. Eng., vol. 25,1896, p. 997, and W. R. Ingalls, idem, p. 147. 

On the Sain Alto mines, Zacatecas, see E. Halse, idem, vol. 29,1900, p. 502, and J. N. Nevius, Eng. and Min. 

Jour., vol. 75, 1903, p. 920. This locality is also rhyolitic. On the tin deposits of Guanajuato, see A. H. 

Bromly, Trans. Am. Inst. Min. Eng., vol. 36,1906, p. 227.

« Jour. Geology, vol. 11, 1903, p. 135. On the ores of Banca and Billiton, see R. Beck, Zeitschr. prakt. 

Geologic, 1898,,p. 121. W. R. Rumbold (Bull. Am. Inst. Min. Eng., September, 1900) had described 

the tin deposits of the Kinta Valley, Malay States. He mentions deposits in limestone. On topaz and tin 

ores in Malaya see W. R. Jones, Geol. Mag., 1916, p. 255.

3 Econ. Geology, vol. 11,1916, p. 652.

4 For discussions on the genesis of cassiterite veins, see A. Daubre"e, Etudes synthe'tiques de geologic 

expfrimentale, pp. 28-71; J. H. L. Vogt, Zeitschr. prabt. Geologic, 1895, p. 145, and Trans. Am. Tnst. Min. 

Eng., vol. 31,1901, p. 125; and W. Lindgren, idem, vol. 30,1900, p. 578. See also F. Gautier, Actes Sop. sci. 

Chili, vol. 5, 1895, p. 92. R. Recknagel (Trans. Gcol. Soc. South Africa, vol. 12,1910, p. 128) attributes the 

South African tin deposits to magmatic differentiation, and in part to concentration by lateral secretion.
METALLIC ORES. 693

minerals, especially amblygonite and lepidolite, are now the species 

of chief commercial value.

American deposits of tin, more or less resembling those of Cornwall 

and Saxony, are found in the York region, Alaska; in Rockbridge 

County, Virginia, and near El Paso, Texas. The Alaskan field has 

been well studied by A. J. Collier * and A. Knopf , 2 who describe both 

lodes and placers. The typical cassiterite is disseminated in more or 

less altered granitic dikes, essentially greisen, consisting of quartz, 

zinnwaldite, calcite, and fluorspar. In one case the ore is intimately 

associated with tourmaline, and other borates and borosilicates, 

including the rare minerals hulsite and paigeite, are also found. It 

also occurs in veins which cut through metamorphic slates a 

rather unusual development. At the Cash mine, in Virginia, according to L. C. Graton,3 the ore is in quartz veins in granite, the walls 

of the veins being converted into greisen. W. H. Weed 4 and G. B. 

Richardson 5 have studied the tin deposits of the Franklin Mountains 

near El Paso, where the ore is found in quartz under conditions which 

Weed thinks, resemble those of Cornwall. The Temescal deposit, in 

southern California, as described by H. W. Fairbanks,6 may also belong to the class. The vein material consists almost wholly of tourmaline and quartz, formed by gradual replacement of the granite walls.

Another mode hi which cassiterite occurs is as an original constituent in pegmatite. It is thus found, although scantily, in the 

famous localities in Maine for lithia tourmalines and lepidolite. 

The workable cassiterite of the Carolina tin belt, according to L. C. 

Graton,7 is also in pegmatite, none being found in the wall rock. 

Here again lithia minerals are found, namely, lithiophilite and 

spodumene. The tin ores of the Black Hills, in South Dakota, seem 

to belong under this heading, and the Etta mine especially is noted 

for its enormous crystals of spodumene and columbite. In this 

locality crystalline faces of spodumene are exposed which are from 

30 to 40 feet long; and in the Ingersoll claim a single mass of columbite is said to have weighed more than 2,000 pounds.8 Cassiterite

1 Bull. U. S. Geol. Survey No. 229,1904; and also in Bull. No. 225,1903, p. 154; Bull. No. 259, 1905, p. 120; 

and Eng. and Min. Jour., vol. 76,1903, p. 999.

» Bull. U. S. Geol. Survey No. 345, 1908, p. 251; No. 358, 1908, and Econ. Geology, vol. 4, 1909, p. 214. 

See also A. H. Brooks, Mineral Resources U. S. for 1900, U. S. Geol. Survey, 1901, p. 267, and Bull. No. 213, 

1902, p. 92; and E. Rickard, Eng. and Min. Jour., vol. 75,1903, p. 30.

» Bull. U. S. Geol. Survey No. 293,1906, p. 44. See also T. Ulke, Mineral Resources U. S. for 1893, U. S. 

Geol. Survey, 1894, p. 178, and H. G. Ferguson, Bull. Virginia Geol. Survey No. 15A, 1918.

4 Bull. U. S. Geol. Survey No. 178,1901, and also in Bull. No. 213, 1902, p. 170.

» Bull. U. S. Geol. Survey No. 285,1905, p. 146.

8 Am. Jour. Sci., 4th ser., vol. 4,1897, p. 39.

i Bull. U. S. Geol. Survey No. 293, 1906, and also In Bull. No. 260, 1904, p. 188. Other papers on the 

Carolina belt are by J. H. Pratt, Mineral Resources U. S. for 1903, U. S. Geol. Survey, 1901, p. 337, and 

Pratt and D. B. Sterrett, Bull. North Carolina Geol. Survey No. 19,1904.

8 See W. P. Blake, Trans. Am. Inst. Min. Eng., vol. 13, 1885, p. 691. On the Black Hills mines, seo also 

E. W. Claypole, Am. Geologist, vol. 9,1892, p. 228, and J. D. Irving, Prof. Paper U. S. Geol. Survey No. 20, 

1904, p. 95.
694 DATA OF GEOCHEMISTRY.

in pegmatite, accompanied by corundum, is" reported by P. F. 

Molengraaf * from Swazieland, South Africa.

The tin ores of Bolivia represent still another class of associations. 

Cassiterite in masses resembling hematite, and the four sulphosalts 

of tin, are here found in veins carrying ores of silver, lead, and 

bismuth in rocks of recent volcanic origin. According to A. W. 

Stelzner 2 the rock is commonly dacite or trachyte; but at Potosi, 

as described by A. F. Wendt,3 the matrix is rhyolite. The vein 

matter is quartz, with carbonates and barite. In these deposits we 

evidently have a transition between the ordinary tin-bearing vein 

and the type of vein characterized by silver-lead ores. W. R. Rumbold,4 who has studied the Bolivian deposits, regards them as of 

pneumatolytic origin.

ARSENIC, ANTIMONY, AND BISMUTH.

Arsenic, antimony, and bismuth are three closely related elements. 

Arsenic, from a purely chemical point of view, is a nonmetal; for, 

despite its metallic appearance, it is an acid-forming element, and 

only in exceptional cases does it play the part of a base. Antimony 

is more commonly acid than basic, but in bismuth the basic character 

is strongly predominant, except in its sulphosalts.

All three elements are found native, and also in many closely 

related compounds. Among the latter the sulphosalts of silver, 

lead, copper, and tin have already been mentioned, and few others 

remain to be named. Berthierite is- a sulphantimonite of iron, 

FeSb2S4 , and lorandite is a sulpharsenite of thallium, TlAsS2 . There 

are also a number of arsenides, antimonides, and bismuthides 

of silver, copper, nickel, cobalt, platinum, etc., which are best considered under the several metals that characterize them. For 

present purposes it is enough to mention the iron arsenides, lollingite, 

FeAs? , and leucopyrite, Fe3As4 , and also the sulpharsenide, arsenopyrite, FeAsS. Arsenopyrite or mispickel is the most important 

ore of arsenic.

Native arsenic, native antimony, and native bismuth are all rather 

common minerals, and with them the arsenide of antimony, allemontite, SbAs3 , j may be grouped. There are also natural sulphides, 

selenides, and tellurides, as follows:

1 See abstract in Zeitschr. prakt. Geologic, 1900, p. 140.

2 Zeitschr. Deutsch. geol. Gesell.. vol. 49, 1897, p. 51. See also M. Frochot, Annales des mines, 9th ser., 

vol. 19, 1901, p. 186.

«Trails. Am. Inst. Min. Eng., vol. 19, 1890, p. 90.

« Econ. Geology, vol. 4, 1909, p. 321. See also J. T. Singewald and B. L. Miller, Eng. and Min. Jour,, 

vol. 102,1916, p. 533. Some of these ores contain germanium.
METALLIC ORES. 695

Realgar.....................................................AaS.

Orpiment. .................................................A82S3 .

Stibnite.....................................................Sb2S3 .

Metastibnite................................................Sb2S3 .

Bif inuthinite............................................... -Bi2S3 .

Guana j uatite................................................Bi2Se3 .

Tetradymite................................................Bi2Te3 .

Joseite ! .....................................................Bi2Te.

Wehrlite l ..................................................Bi3Te2 .

Grunlingite.................................................Bi4TeS3 .

Kermesite................................................... Sb2S20.

A sulphide of bismuth, antimony, copper, and iron, found in Tasmania, has b.een named histrixite. It may be a mixture of sulphides.

Several of these minerals have been produced artificially. J. 

Durocher 2 prepared stibnite and bismuthinite by the action of 

hydrogen sulphide upon the volatilized chlorides of antimony and 

bismuth. H. de Senarmont 3 found that when pulverized realgar or 

orpiment was heated to 150° with a solution of sodium bicarbonate 

in a sealed tube they dissolved and were later redeposited as crystallized realgar. Amorphous antimony sulphide, treated in the same 

way at 250°, also dissolved and crystallized as stibnite. The precipitated sulphide of bismuth, similarly heated to 200° with a solution of an alkaline sulphide, gave crystals of bismuthinite. E. We'inschenk 4 obtained orpiment and stibnite by heating solutions of arsenic 

or antimony with ammonium sulphocyanate to 180° in a.sealed 

tube. According to A. Carnot,5 stibnite and bismuthinite are easily 

formed by passing hydrogen sulphide at a dull red heat over other 

compounds of antimony or bismuth. Realgar, orpiment, stibnite, 

and bismuthinite are all reported by Mayencon 6 as found among the 

sublimation products of a burning coal mine.7

C. Doelter 8 states that stibnite at 80° is slightly soluble in water, 

and that recrystallization from the solution is also perceptible. The 

same statement holds for arsenopyrite, FeAsS. In several localities 

the deposition of arsenical or antimonial sulphides from hot springs 

has been observed. W. H. Weed and L. V. Pirsson 9 report both 

realgar and orpiment from a hot spring in the Yellowstone National 

Park, and G. F. Becker 10 found sulphides of arsenic and antimony

1 Formula approximate only. Sulphur or selenium partly replaces tellurium. 

3 Compt. Eend., vol. 32,1851, p. 825. 

8 Annales chim. phys., 3d ser., vol. 32,1851, p. 129. 

« Zeitschr. Kryst. Min., vol. 17,1890, p. 497.

5 See L. Bourgeois, Reproduction artificielle des min6raux, pp. 41, 42. 

o Compt. Rend., vol. 86,1878, p. 491; vol. 92,1881, p. 854.

' On the conditions governing the formation of orpiment and realgar, see W. Borodowsky, Sitzungsb. 

Naturf. Gesell. Univ. Dorpat, vol. 14, p. 159. Also in Chem. Abstracts, vol. 1,1907, p. 1106. 

s Min. pet. Mitt., vol. 11,1890, p. 322.

9 Am. Jour. Sci., 3d ser., vol. 42,1891, p. 401. At another spring in the Park, Arnold Hague (idem, vol. 

34,1887, p. 171) found a deposit of scorodite, an arsenate of iron.

10 Mon. U. S. Geol. Survey, vol. 13,1888, p. 344.
696 DATA OF GEOCHEMISTRY.

in a sinter at Steamboat Springs, Nevada. In 3,403 grams of this 

sinter, as analyzed by W. H. Melville, were found the following substances:

Sulphides, etc., found in sinter.

Grams.

Au........................................................... 0. 0034

Ag.......................................................... .0012

HgS....................................................... . 0070

PbS.............................................. 1......... . 0720

CuS..................'....................................... . 0424

Sb2S3+As2S3 ................................................ 78. 0308

Fe203 -...-..-.--..-...-..-...-....-...--.......--.-.-....... 3. 5924

The antimony sulphide was in the amorphous, orange-colored form, 

to which Becker gave the name of metastibnite. Crystals of ordinary 

stibnite have since been discovered by W. Lindgren 1 in the same 

sinter, apparently of quite recent formation. The locality, it must 

be observed, is one which yields mercury, and G. F. Becker 2 has 

reported stibnite from several quicksilver mines in California. A 

similar association of stibnite and cinnabar is found at Monte Amiata 

in Tuscany; 3 and at Huitzuco, Mexico, stibnite occurs with livingstonite, kermesite, barcenite, and some cinnabar in a matrix of gypsum.4 Cinnabar has also been noted in the antimony mines of Corsica.5 According to Coquand,6 the antimony ores at Pereta, Tuscany, 

are of solfataric origin. This mode of deposition, which genetically 

connects antimony and mercury, may be ascribed to the fact that 

both metals form easily volatile compounds. The same property is 

shared by arsenic, but deposits of other than solfataric nature are 

known. At least there are deposits in which no indication of solfataric action can now be discerned. The sulphides of arsenic and 

antimony are easily soluble in alkaline solutions, and in that way 

may be transported to points far distant from their original ore 

bodies. The sulphide of bismuth is much less soluble.

Stibnite is the most important ore of antimony. Its deposition 

from solution is in most cases evident, and its alkaline solutions, 

which also dissolve silica, seem to have formed the typical occurrences, 

in which stibnite is intimately associated with quartz. It is so found y 

in the mines of Sevier County, Arkansas; 7 in Mexico and in Corsica, 

where the ore bodies occur in sericitic schists. At Kostainik, in **' 

Serbia, according to R. Beck and W. von Fircks,8 the stibnite is i 

found in trachyte, in graywacke, and also as a replacement in lime1 Trans. Am. Inst. Min. Eng., vol. 36,1906, p. 27.

2 Op. cit.,p.389. ^

3 B. Lotti, Zeitschr. prakt. Geologie, 1901, p. 43. v

4 J. G. Aguilera, Trans. Am. Inst. Min. Eng., vol. 32,1902, p. 307.

&Nentien, Annalesdes mines, 9th ser., vol. 12,1897, p. 251. *~" 

«Bull. Soc. g6ol. France, 2d ser., vol. 6,1848-49, p. 91.

'See C. E. Wait, Trans. Am. Inst. Min. Eng., vol. 8,1879, p. 42; J. C. Branner, Ann. Rept. Arkansas > *« 

Geol. Survey, 1888, vol. 1, p. 136; and G. H. Ashley, Proc. Am. Philos. Soc., vol. 36,1897, p. 300. 

s Zeitschr. prakt. Geologie, 1900, p. 33. -
METALLIC ORES. 697

stone. Arsenopyrite also occurs most commonly with quartz, 

oftenest in metamorphic schists and sometimes in serpentine. 1 

When either arsenic, antimony, or bismuth is found in a metalliferous 

vein, associated with silver, copper, or lead, it is usually combined 

with those metals in the form of sulphosalts.

By oxidation of the sulphides a large number of secondary minerals can be formed. First of all are the oxides, as follows:

Arsenolite 2 ......................................As203) isometric.

Claudetite 2 ......................................As203 , monoclinic.

Senarmontite................................... Sb203 , isometric.

Valentinite......................................Sb203 , orthorhombic.

Cervantite.......................................Sb204 .

Bismite, or bismuth ocher 3 ......................Bi203 .3H20.

Stibiconite......................................H2Sb206 .

Bismuth also forms two basic carbonates, bismutite and bismutosphserite, and a rare oxychloride, daubreeite. The oxides of antimony form important ore bodies at Altar, Sonora, Mexico,4 and in 

Neocomian limestone at Mount Hamimat, Province of Constantine, 

Algeria.0

From oxidation of the sulphosalts a large number of arsenates, 

antimonates, and various compounds of bismuth have been derived. 

Some of these were mentioned in the preceding sections of this 

chapter; others are salts of calcium, magnesium, iron, or manganese. 

For example, pharmacoJite is an arsenate of lime, pharmaco'siderite 

an arsenate of iron, and sarkinite an arsenate of manganese. Atopite, 

schneebergite, and romeite are antimonates of lime. Some of these 

compounds, and there are many others, may have been formed by 

the action of percolating arsenical or antimonial solutions upon 

carbonates of lime, magnesia, manganese, or iron, or upon hydroxides 

of the two metals last named. There are also arsenates of bismuth, 

and a tellurate, a vanadate, a molybdate, and a silicate of the same 

base. The strange mineral longbanite is an antimonio-silicate of 

manganese and iron; derbylite and lewisite are antimonio-titanates 

of iron and lime, respectively; and mauzeliite is a similar salt of 

calcium and lead. Derbylite, lewisite, and tripuhyite, Fe2Sb2O7 , are 

found in the cinnabar-bearing gravels of Tripuhy, Brazil.6 They 

were derived from mica schists, but their association with cinnabar 

is suggestive.

1 On the arsenic mines of Hastings County, Ontario, see J. W. Wells, Kept. Bur. Mines, Ontario, 1902, 

p. 101. J. L. Cowan (Eng. and Min. Jour., vol. 78,1904, p. 105) has described an arsenicmino at Briuton, 

Virginia. For the antimony mines of Nova Scotia see W. R. Askwith, Canadian Min. Rev., vol. 20,1901, 

p. 173.

' The true molecular weight, as shown by the vapor density, is more probably represented by the formula As«O6 . A similar doubling may be proper for the other oxides and sulphides of this group.

8 On the composition of bismuth ocher see W. T. Schaller, Jour. Am. Chem. Soc., vol. 33,1911, p. 162.

* E. T. Cox, Am. Jour. Sci., 3d ser., vol. 20,1880, p. 421.

o Coquand, Bull. Soc. ge"ol. France, 2d ser., vol. 9, 1851-52, p. 342.

8 See E. Hussak and G. T. Prior, Mineralog. Mag., vol. 11,1895, pp. 80,176, 302.
698 DATA OF GEOCHEMISTRY.

NICKEL AND COBALT. 1

Among the minor constituents of igneous rocks, nickel is one of 

the commonest. Cobalt is also widely diffused, but in much smaller 

proportions.2 In 262 analyses of igneous rocks made in the laboratory of the United States Geological Survey an average of 0.0274 

per cent of nickel oxide was found. Had it been sought for in all 

cases, this figure might have been slightly reduced, but perhaps not 

materially.

Nickel and cobalt are characteristic elements in meteoric irons 

and also in terrestrial irons of similar character. Indeed, some of 

the "irons" of which analyses are given in another chapter of this 

book 3 are more truly described as native nickel, that being the 

metal which predominates in them. Awaruite and josephinite are 

nickel irons of this kind, in which the percentage of nickel reaches 

60 or even more.

The ores of these metals fall into three principal classes, namely, 

sulphides or arsenides, oxides, and silicates. In the first case the 

chief minerals are as follows:

Millerite.....................NiS.

Beyrichite....................Ni3S4 .

Polydymite 4 ..................Ni4S5 .

Niccolite..................... NiAs.

Chloanthite...................NiAs2 .

Rammelsbergite............... NiAs2 .

Gersdorffite...................NiAsS.

Pentlandite 6 ................. .(Fe,Ni)S.

Jaipurite......................CoS.

Linnseite....."............... .Co3S4 .

Smaltite......................CoAs2 .

Safflorite. .................... CoAs2 .

Skutterudite 5 ..................CoAs3 .

Cobaltite.....................CoAsS.

Carrollite.....................Co2CuS4

Two other arsenides of nickel have recently been described,7 

maucherite and temiskamite. A careful study of the two by Chase 

Palmer, however, has shown that they are identical, and that the 

true formula is Ni4As3 .

.With these minerals we may include the nickel telluride, melonite, 

and the antimonide, breithauptite, NiSb. Ullmannite is a sulphide 

of antimony and nickel, NiSbS.8 Corynite and wolfachite are mix1 For a general paper upon nickel and its occurrences see P. Argall, Proc. Colorado Sci. Soc., vol. 4,1893, 

p. 395. A note by A. G. Charlton follows (p. 420) on Colorado nickel ores. Oh nickel in the Mansfeld 

copper shales see Baeumler, Zeitschr. Deutsch. geol. Gesell., vol. 9,1857, p. 25. On cobalt ores at Schweina, 

Thuringia, see F. Beyschlag, Zeitschr. prakt. Geologic, 1898, p. 1. ' On cobalt in Mexico, G. de J. Caballero, 

Mem. Soc. cient. Ant. Alzate, vol. 18,1902, p. 197. 0. Stutzer (Zeitschr. prakt. Geologic, 1906, p. 294) has 

described tourmaline-bearing cobalt veins at San Juan, Atacama, Chile. The ore is cobaltite. c An important volume is the Report of the Royal Ontario Nickel Commission, Toronto, 1917.

2 On the wide diffusion of cobalt and nickel in nature see K. Kraut, Zeitschr. angew. Chemie, 1906, p. 1793. 

8 See ante, p. 326.

4 The Sudbury polydymite is Vfery nearly NiaFeSo.

5 There is also a variety containing much nickel replacing cobalt. Bismutosmaltite, Co(AsBi)3, is a 

related mineral.

G Another nickel-iron sulphide has been called gunnarite. Its formula is near Fe-^NisSa. Still another, 

akin to pentlandite, is the incompletely described heazlewoodite.

7 On maucherite, see F. Grunling, Centralbl. Min., Geol. u. Pal., 1913, p. 225. On temiskamite, T. L. 

Walker, Am. Jour. Sci., 4th ser., vol. 37, 1914, p. 170. Palmer's work is in Econ. Geology, vol. 9, 1914, 

p. 664.

8 A similar sulphide, with bismuth partly replacing antimony, has been named kallilite.
METALLIC ORES. 699

tures of a salt of the last type with the corresponding salt NiAsS. 

Glaucodot is sulpharsenide of cobalt and iron, and alloclasite is similar, but with bismuth partly replacing arsenic. Another mineral of 

the formula NiCoS2Sb2 has been named willyamite.

Arsenides and antimonides of nickel are known as accidental furnace products.1 The crystalline sulphides of cobalt and nickel have 

also been repeatedly prepared artificially. li. deSenarmont 2 heated 

solutions of potassium sulphide with nickel or cobalt chloride to temperatures between 160° and 180° in a sealed tube, and obtained the 

compounds NiS, Ni3S4 , and Co3S4 , corresponding to the natural minerals. C. Geitner 3 also produced crystals of Ni3S4 by heating metallic nickel with sulphurous acid or a solution of nickel sulphite under 

pressure to 200°. E. Weinschenk4 heated solutions of cobalt or 

nickel salts with ammonium sulphocyanate to 180° in a sealed tube 

and so produced crystalline NiS or CoS, respectively. T. Hiortdahl 5 

also produced jaipurite by fusing cobalt sulphate with barium sulphide and common salt.

These scanty data show that the minerals of this group may be 

produced in either the wet or the dry way, and their natural occurrences point to the same conclusion. Millerite, for instance, forms 

beautiful tufts of slender, hairlike needles in geodes lined with crystals of dolomite. Specimens of this kind are familiar objects to collectors of minerals. Millerite is also reported by Des Cloizeaux ° as 

found in the coal measures of Belgium, and he mentions linnseite in. 

coal from Glamorganshire, Wales. On the other hand, as J. H. L. 

Vogt 7 has shown, the °nickeliferous pyrrhotites are often, if not 

always, distinct segregations from molten magmas. On this subject, 

however, controversy still reigns, and especially with reference to the 

nickel ores of Sudbury, Canada. Here the ores are chiefly pyrrhotite with admixtures of pentlandite, a certain amount of chalcopyrite 

being also present. The matrix is norite, although the earlier 

observers termed it diorite. Their magmatic origin has been advocated by R. Bell, 8 H. B. von Foullon, 0 T. L. Walker,10 A. P. Coleman/ 1

1 See L. Bourgeois, Reproduction artiftcielle des mine'raux, p. 35, for old instances. Also A. Brand, 

Zeitschr. Kryst. Mill., vol .12,1887, p. 234, on breithauptite.

2 Annalos chim. phys., 3d ser., vol. 32,1851, p. 129.

3 Liebjg's Annalen, vol. 129,1864, p. 350.

4 Zeitschr. Kryst. Min., vol. 17,1890, p. 497.

& Compt. Rend., vol. 65,1867, p. 75. Jaipurite is also known as syepoorite.

6 Bull. Soc. min., vol. 3,1880, p. 170.

7 Zeitschr. prakt. Geologic, 1893, pp. 125,357.

3 Bull. Geol. Soc. America, vol. 2,1890, p. 125. Another paper by Bell, on Sudbury, appears in Ann. 

Kept. Geol. Survey Canada, 2d ser., vol. 5, F, 1890-91.

8 Jahrb. K.-k. geol. Reichsanstalt, vol. 42,1892, p. 223. The nickel ores of Schwelderich, Bohemia, are 

described as analogous to those of Sudbury. 

10 Quart. Jour. Geol. Soc., vol. 53,1897,p. 40.

" Bull. Geol. Soc. America, vol. 15,1904, p. 551. J_u Rept. Ontario Bur. Mines, 1904, pt. 1, p. 192, Colcmun 

has a long paper on the " Northern Nickel Range." The report of the same bureau for 1905, pt. 3, contains 

a monograph by Coleman on the Sudbury ores. A later paper by Coleman is in Jour. Geology, vol. 51, 

1907, p. 759, and another in Econ. Geology, vol. 12, p, 427,1917.
700 DATA OF GEOCHEMISTRY.

D. H. Browne, 1 and others. A. E. Barlow,2 for example, repeatedly 

speaks, of the "nickel-bearing eruptive." Browne compares the 

occurrences at Sudbury with the phenomena observed in cooling a 

copper-nickel matte, in which the copper sulphides concentrate along 

the margins of the mass, and the nickel sulphides at the center, 

This arrangement of ores, chalcopyrite near the wall rock, then pyrrhotite carrying nickel, and finally nickel sulphide, is the order 

observed at Sudbury.

R. Beck,3 C. W. Dickson,4 and W. Campbell and C. W. Knight,5 

on the other hand, have argued strongly in favor of a secondary 

origin of these ores a deposition from circulating solutions.6 A 

similar view is expressed by F. W. Voit 7 concerning the nickel ores 

of Dobschau, Hungary. Here the arsenides of nickel occur in a 

carbonate gangue at or near contacts of diorite. At Mine La Motte, 

Missouri, linnseite is found with lead and copper ores in bodies which 

C. R. Keyes 8 describes as metasomatic replacements in limestone. 

Small quantities of nickel are shown in analyses of the adjacent 

granites.

At the Gap mine, in Lancaster County, Pennsylvania, pyrrhotite 

and chalcopyrite occur with secondary millerite in an amphibolite, 

which J. F. Kemp 9 thinks is an altered gabbro or norite. This 

deposit Kemp regards as originally magmatic. In the serpentines 

of Malaga, Spain, according to F. Gillman,10 niccolite is found, 

altered to silicates of nickel at the surface, but associated with chromite and augite in the norites below. Here again a magmatic origin 

is indicated. The nickeliferous pyrrhotites of the southern Schwarzwald are regarded by E. Weinschenk u as not magmatic.

Near Lake Temiskaming, Ontario, an extraordinary group of 

deposits of associated cobalt, nickel, arsenic, and silver ores was 

discovered in 1903.12 In this district native silver and native bismuth are found, together with niccolite, chloanthite, smaltite, milleri School oLMines Quart., vol. 16,1895, p. 297; and Econ. Geology, vol. 1,1906, p. 487.

«Econ. Geology, vol. 1,1906, pp. 454,545.

> The nature of ore deposits, Weed's translation, p. 41.

* Trans. Am. Inst. Min. Eng., vol. 34, p. 3,1904. See also Jour. Canadian Min. Inst., vol. 9,1906, p. 236.

* Eng. and Min. Jour., vol. 82,1906, p. 909. These authors base their opinions on the microscopic structure of the pyrrhotite.

e Other memoirs upon Sudbury and its ores are by J. H. Collins, Quart. Jour. Geol. Soc., vol.44,1888, 

p. 834; J. Garnier, Me"m. Soc. inge"n. civils (France), vol. 44, p. 239; E. R. Bush, Eng. and Min. Jour., vol. 

57,1904, p. 245; T. L. Walker, Am. Jour. Sci., 3d ser., vol. 47, 1894, p. 312: F. W. Clarke and C. Catlett, 

Bull. U. S. Geol. Survey No. 64, 1890, p. 20; S. St. Clair, Min. and Sci. Press, vol. 109,1914, p. 248; L. T. 

Silver, Canadian Min. Rev., vol. 21,1902, p. 207; T. L. Walker, Econ. Geology, vol. 10,1915, p. 536; A. M. 

Bateman, idem, vol. 12,1917, p. 391; M. A. Dresser, idem, p. 563; W. H. Goodchild, idem, vol. 13,1918, p. 

137; H. M. Roberts and R. D. Longyear, Bull. Am. Inst. Min. Eng., 1918, p. 554.

7 Jahrb. K.-k. geol. Rcichsanstalt, vol. 50,1900, p. 717.

8 Missouri Geol. Survey, vol. 9, pt. 4,1896, p. 82.

9 Trans. Am. Inst. Min. Eng., vol. 24,1894, p. 620. 

i» Trans. Inst. Min. and Met. (London), vol. 4, lS96,.p. 159.

11 Zeitschr. prakt. Geologic, 1907, p. 73.

12 See the reports by W. G. Miller, Rept. Ontario Bur. Mines, 1904, pt. 1, p. 96; 1905, pt. 2. Also in Eng! 

and Min. Jour., vol. 76,1903, p. 888.
METALLIC ORES. 701

ite, cobaltite, argentite, dyscrasite, pyrargyrite, tetrahedrite, arsenopyrite, etc., in relations which are interpreted by Miller as suggesting 

a deposition from heated waters, which latter were "probably 

associated with the post-Middle Huronian diabase and gabbro 

eruption." According to Miller, the deposits are analogous to 

those of Annaberg, Saxony, and Joachimsthal, Bohemia, which are 

classical localities for cobalt and nickel minerals. The original 

source of the Temiskaming ores has not yet been clearly determined. 

They may represent a leaching of the accompanying eruptive rocks, 

or they may have been brought from below; at all events, they are 

not igneous segregations. 1

By oxidation or carbonation the sulphides and arsenides of nickel 

and cobalt are transformed into sulphates, arsenates, carbonates, 

oxides, etc. Morenosite, NiS04 .7H2 0; bieberite, CoS04 .7H2 0; the 

arsenates, roselite, erythrite, annabergite, forbesite, and cabrerite; 

the carbonates sphserocobaltite, zaratite, and remingtomte; the oxide 

bunsenite; and the hydroxides asbolite, heubachite, heterogenite, 

transvaalite, etc., are among these products of alteration. Bunsenite, 

NiO, was prepared artificially by J. J. Ebelmen, 2 through the action 

of lime on fused nickel borate. Ferrieres and Dupont 3 also obtained it by heating nickel chloride to redness in a current of steam. 

Neither process seems to hear any close relation to the observed 

occurrences of bunsenite in nature. Asbolite, or earthy cobalt, is 

an indefinite mixture of manganese and cobalt hydroxides, and has 

some significance as a workable ore.4 This association of cobalt and 

manganese is not uncommon, and many manganese ores contain more 

or less cobalt.

The hydrous silicates of nickel form a distinct class of ores, differing genetically from the sulphides. They are found in connection 

with serpentine or other hydromagnesian rocks, and in some instances, 

if not always, they represent concentrations from peridotitic magmas, 

and especially from nickeliferous olivine. At Riddles, Oregon, for 

example, the parent rock is a saxonite or harzburgite, containing, 

as shown by my own analysis, 5 0.10 per cent of NiO. The olivine 

separated from the rock contained 0.26 per cent; and from this mineral the nickel silicates were doubtless formed. Similar silicate ores

1 These ores have recently been studied microscopically by W. Campbell and C. W. Knight (Econ. 

Geology, vol. 1,1906, p. 767), who find that smaltite was first formed, then niccolite, then calcite, with 

argentite, native silver, and native bismuth later.

2 Compt. Rend., vol. 33,1851, p. 525.

3 See L. Bourgeois, Reproduction artificielle des min<5raux, p. 51.

4 As at Mine Lamotte, Missouri, and in New Caledonia. On the New Caledonia cobalt ores, see G. M. 

Colvocoresses, Eng. and Min. Jour., vol. 76,1903, p. 816, and A. Liversidge, Minerals of New South Wales, 

pp. 275 et. seq.

» F. W. Clarke and J. S. Diller, Bull. U. S. Geol. Survey No. 60, 1890, p. 21. See also, with regard to 

this locality, A. R. Ledoux, Canadian Min. Rev., vol. 20,1901, p. 84; W. L. Austin, Proc. Colorado Sci. 

Soc., vol. 5, 1898, p. 173; and H. B. von Foullon, Jahrb. K.-k. geol. Reichsanstalt, vol. 42, 1892, p. 223, 

Von Foullon also describes the deposits at Revda, Frankenstein, and Mount Avala'. A later report of 

the Riddles ores, by G. F. Kay, appears in Bull. U. S. Geol. Survey No. 315,1907, p. 120.
702 DATA OF GEOCHEMISTRY.

are found in North Carolina; l at Revda in the Urals; at Frankenstein, Prussian Silesia, in serpentine; and at Mount Avala, Serbia, 

with mercurial minerals. The most important deposits, however, 

are in New Caledonia,2 where asbolite also occurs. Chromite and various hydromagnesian minerals are generally associated with the nickel 

ores.

These silicates are rarely, if ever, found as definite mineral species, 

although they have been described as such. Genthite appears to be 

H4Mg2Ni4 (Si04 ) 3 .4H2 0, and connarite is near H4Ni2Si3 010 . Another silicate from New Caledonia, called nepouite,3 has been given 

the formula (NiMg) 3Si2 07 .2H2 0. Alipite, desaulesite, garnierite, noumeite, pimelite, refdanskite, and rottisite are uncertain substances, 

mixtures of nickel silicates with magnesian compounds and free 

silica. The following analyses will serve to illustrate the variable 

composition of these ores:

Analyses of nickel silicates.

A. From Riddles, Oregon. Analysis by F. W. Clarke, Bull. U. S. Geol. Survey No. 60,1890, p. 21.

B. From Riddles. Analysis by-Hood, Mineral Resources U. S. for 1882, U. S. Geol. Survey, 1883, p, 404. 

Probably this sample was dried at or near 100° before analyzing.

C, D, E. From New Caledonia. Analyses by A. Liversidge, Minerals of New South Wales, pp. 275-280> 

Liversidge gives 19 analyses in all, including several by Leibius.

Si02 ......... .........................

AI o

Fe203 ...... .......... ................. Nib..................................

MgO........... .......................

H2O at 100°....... ....................

A

44.73

| 1.18

27.57

10,56

8.87

6.99

99.90

B

40. 55

} 1.33

29.66

21.70

1 7.00

'

100. 24

C

48.25

} .55

14.60

16.40

10.95

8.82

99.57

B

38.35

.40

.15

32.52

10.61

fi 44

n ^Q

100. 00

E

50.15

.577

Trace.

10.20

17.43

11.28 in Q7

100.00

In one respect all the ores of nickel seem to agree. Their magmatic 

associate is always a subsilicic rock, such as norite, peridotite, or 

sometimes diabase or diorite. In no case are they clearly shown to 

have originated from persilicic magmas.

CHROMIUM.

Like nickel, chromium is widely diffused in the subsilicic rocks, 

the average proportion found in 256 analyses of igneous rocks in the 

laboratory of the United States Geological Survey being 0.05 per

1 See H. J. Biddle, Mineral Resources U. S. for 1886, U. S. Geol. Survey, 1887, p. 170. The mother rock 

here is dunite. See also A. E. Barlow, Jour. Canadian Min. Inst., vol. 9,1906, p. 303. Barlow regards these 

ores as formed by the leaching of the peridotite.

2 See A. Liversidge, Minerals of New South Wales, p. 275; J. Gamier, Compt. Rend., vol. 86, 1878, p. 

684; D. Levat, Mfrn. Assoc. frang. av. sci., 1887, p. 534; and F. D. Power, Trans. Inst. Min. Met., vol. 8, 

1900, p. 427. Liversidge gives several analyses of garnierite and noumeite. See also J. S. Leckie, Jour. 

Canadian Min. Inst:, vol. 6,1903, p. 169.

8 E. Glasser,Compt. Rend., vol. 143,1906, p. 1173. Also Annales des mines, 10thser., vol. 4,1904, p. 448.
METALLIC ORES.

cent of Cr2O3 . The native metal has not been found, nor are any terrestrial sulphides of chromium known, although the mineral daubre"eHte, FeCr2S4 occurs in some meteoric irons. The one important ore 

of chromium is chromite, or chromic iron. There are also the lead 

chromates, mentioned in a previous section of this chapter; the two 

sulphates knoxvillite and redingtonite: and the silicates represented 

by chromiferous garnet, diopside, mica, and tourmaline. The claylike silicates avalite, milosin, and alexandrolite also contain chromium 

as an essential constituent. 1 Dietzeite, from the Chilean niter beds, 

is an iodate and chromate of calcium. Of all these species chromite 

alone needs any further consideration.

In the chapter upon rock-forming minerals chromite was described 

as a member of the spinel group. Its ideal formula is FeCr204, but it 

rarely, if ever, is found in a state of even approximate purity. It 

commonly contains isomorphous admixtures of other spinels, whose 

presence is revealed in the analyses. The following examples will 

serve to illustrate its variations: 2

Analyses of chromite..

A. From Price Creek, North Carolina. Analysis by C. Baskerville.

B. From Corundum Hill, North Carolina. Baskerville.

C. From Corundum Hill. Analysis by T. M. Chatard, in the laboratory of the United States Geological 

Survey.

D. From Webster, North Carolina. Analysis by I-I. W. Foote. Variety named mitchellitc. For A, B, 

and D, see J. H. Pratt and J. V. Lewis, North Carolina Geol. Survey, vol. 1, p. 369,1905. Magnochromito 

is another name for a magnesian chromite.

E. From Tampadel, lower Silesia. Analysis by Laszczynski. Described by H. Traube, Zeitschr. 

Peutsch. geol. Gesell., vol. 46, p. 50,1894.

/

rv n

±+ Feb.3..................................

^MnO. ....... ..........................

CoO.NiO.............................

*> CuO. .................................

j MgO..................................

CaO.. ................................

-; TiOo......... ......................... ' p o

j

A

59.20

7. 15

25.02

.92

4.42

3.20

99.91

B

57.20

7.82

25.68

.69

5.22

2.80

99.41

r

45.94

2.51

42.90

.84

.16

.40

2.81

1.40

3.20

.36

19

100. 64

D

39.95

29.28

13.90

17. 31

100. 44

E

41. 23

24. 58

19.04

.58

14. 77

100.20

Chromite was first produced artificially by J. J. Ebelmen, 3 who 

fused chromic oxide, ferric oxide, and boric oxide together, with a 

little tartaric acid added to reduce the iron to the ferrous state. By 

adding small amounts of alumina and magnesia the composition

1 See S. M. Losanitsch, Ber. Deutsch. chem. Gesell., vol. 28,1895, p. 2631.

2 See also table in Chapter X, on rock-forming minerals, p. 339. Two of the analyses there given arc repeated here, 

s Annales chiin. phys., 3d ser., vol. 22,1848, p. 228.
704 DATA OF GEOCHEMISTRY.

of the product was made to vary, like that of the natural mineral. 

J. Clouet 1 also prepared chromite by essentially the same process, 

only with trifling differences in detail. S. Meunier 2 obtained 

chromite by oxidizing an alloy of iron and chromium, and suggested 

that such an alloy might be brought up from great depths and 

oxidized by vapors near the surf ace of the earth. There is no direct 

evidence, however, to show that such an alloy exists in nature, and 

the common presence of chromite in meteorites indicates a different 

origin for the mineral.

Chromite is almost exclusively found in subsilicic rocks, such as 

peridotites and the serpentines derived from them. Its occurrence 

in placers as a detrital mineral is of course not excluded by this 

statement. It is distinctly a magmatic mineral, as Vogt and others 

have shown.3

MOLYBDENUM AND TUNGSTEN.

Although molybdenum and tungsten are members of the same 

elementary group with chromium, their geologic affinities are not 

the same. Chromium, as we have seen, is found characteristically in 

subsilicic rocks, while molybdenum and tungsten are commonly associated with granite. Neither metal is found free in nature, nor is 

either one widely diffused.

The principal ore of molybdenum is the sulphide, molybdenite, 

MoS2 . The molybdate of lead, wulf enite, has already been described. 

Calcium molybdate, powellite, koechlinite, the molybdate of bismuth, and belonesite, the molybdate of magnesium, are also known. 

Pateraite is probably an impure molybdate of cobalt. Molybdic 

ocher is a common oxidation product of molybdenite. It is, as shown 

by W. T. Schaller,4 a hydrous ferric molybdate. Another oxidation 

product of molybdenite, ilsemannite, was originally described as an 

oxide, Mo02 .4Mo03 ; but a mineral which is probably the same 

species was found by Schaller 5 to be a sulphate, MoO3 .S03 .5H2O.

1 Annaleschim, phys., s4thser., vol. 16,1869, p. 90.

2 Compt. Rend., vol. 110,1890, p. 424. 

3 See J. H. L. Vogt, Zeitschr. prakt. Geologic, 1894, with special reference to Norwegian deposits. On 

chromite at Kraubath, Styria, see F. Tlyba, idem, 1900, p. 337; and in Asia Minor, K. E. Weiss, idem, 1901, 

p. 250. R. Helmhacker (Min. Industry, 1895, p. 94) describes Austrian localities. On chromite in Maryland, see W. Glenn, Trans. Am. Inst. Min. Eng., vol. 25,1896, p. 481; and on Canadian ores, the same author 

in Seventeenth Ann. Rept. U. S. Geol. Survey, pt; 3,1890, p. 261. M. Penhale (Min. Industry, 1895, p. 92) 

also describes Canadian chromite. The chromite of North Carolina is discussed by J. H. Pratt in Am. 

Jour. Sci., 4th ser., vol. 7, p. 281; and Trans. Am. Inst. Min. Eng., vol. 29,1899, p. 17. See also J. H. Pratt 

and J. V. Lewis, North Carolina Geol. Survey, vol. 1,1905, p. 369.

4 Am. Jour. Sci., 4th ser., vol. 23,1907, p. 297. For koechlinite see also Schaller, Jour. Washington Acad. 

Sci., vol. 4,1914, p. 354.

o Jour. Washington Acad. Sci., vol. 7,1917, p.635, 418. See ante, p. , forthe analysis of a remarkable molybdic mine water, probably derived from the solution of ilsemannite. Also H. F. Yancey, Chem. Met. 

Eng., vol. 18,1918, p. 186.
METALLIC ORES. 705

Artificial molybdenite has been prepared by A. de Schulten.1 

Potassium carbonate was fused with sulphur, and molybdic oxide was 

gradually added, in successive portions, to the melt. Crystals of 

molybdenite were thus formed. Powellite, also, has been made by 

L. Michel,2 who heated sodium molybdate, calcium chloride, and 

sodium chloride together. A little sodium tungstate was added to 

the mixture, in order to reproduce more exactly the natural mineral, 

in which some tungsten is found.

As a rule, molybdenite is a fairly pure compound, although 

Michel 3 has described a variety containing 28.37 per cent of bismuth. 

It was evidently a mixture of molybdenite with bismuthinite. Bismuth is a not infrequent associate both of molybdenite and of 

wolfram.

At Crown Point, Washington, according to A. R. Crook,4 large 

quantities of molybdenite are found in a quartz vein in granite. At 

^ Cooper, Maine, as described by G. 0. Smith,5 the molybdenite is 

found in pegmatite dikes and also in the adjacent granite. It may 

be either an original mineral or an impregnation; probably, says 

Smith, the latter. In Canada molybdenite occurs under a variety 

of conditions, often in granite, but also, according to J. W. Wells,6 

in veins cutting limestone, and associated with pyroxene, calcite, 

quartz, mica, pyrite, etc. The mineral was found embedded sometimes in pyroxene and sometimes in pyrrhotite, and Wells furthermore reports it in veins through pyroxenite. The nature and origin 

of these unusual associations remain to be determined. They 

probably represent contact metamorphism.7

The ores of tungsten are by no means numerous. In addition to 

stolzite, which was mentioned among the ores of lead, there are the 

, tungstate of iron, wolframite, or ferberite when the compound is 

entirely free from manganese; the tungstate of manganese, hubnerite; calcium tungstate, scheelite; the copper salt, cuprotungstite; 

and the recently discovered sulphide, tungstenite, WS2 , the equivalent of molybdenite, which it resembles. 8 There is also an alteration 

product, tungstic ocher, which in one instance at least has been shown by 

W. T. Schaller 9 to be a hydrous ferric tungstate, Fe203 . WO3 .6H2O, and 

to which he has given the name ferritungstite. Of these, wolframite,

« Geol. Foren. Forhandl., vol. 11,1889, p. 401. 

2 Bull. Soc. min., vol. 17,1894, p. 612. 

a Idem, vol. 22,1899, p. 29. 

« Bull. Geol. Soc. America, vol. 15,1904, p. 283. 

& Bull. U. S. Geol. Survey No. 260,1905, p. 197.

8 Canadian Min. Rev., vol. 22, 1903, p. 113. On molybdenite in Ontario. See A. L. Parsons, Rcpt. 

Ontario Bur. Mines, No. 26, pf. 1,1017, p. 275.

' Bull. No. Ill of the U. S. Bur. Mines, 1916, by F. W. Horton, is a good general report on molybdenum. 

«See R. C. Wells, Jour. Washington Acad. Sci., vol. 7,1917, p. 596. 

0 Jour. Washington Acad. Sci., vol. 1,1911, p. 24.

113750° 10 Bull. 695 45
706 - DATA OF . GEOCHEMISTRY.

hubnerite, ferberite, and scheelite are economically important, and- all 

four have been prepared artificially;1

N. S. Manross 2 obtained scheelite by fusing sodium tungstate with 

calcium chloride. A. Cossa 3 also prepared it by fusing the amorphous compound, CaW04, with common salt. H. Debray 4 heated 

amorphous calcium tungstate with lime in a current of gaseous hydrochloric acid, and so effected its crystallization. He also heated a mixture of tungstic oxide and ferric oxide in the same gas, forming in 

that way both wolframite and magnetite. Some of the tungstic oxide 

crystallized at the same time. A. Geuther and E. Forsberg 5 produced wolframite and its manganesian varieties by fusing sodium 

tungstate with ferrous chloride or with the mixed chlorides of iron 

and manganese. L. Michel, 0 by fusing sodium tungstate and sodium 

chloride with the chlorides of calcium, manganese, iron, or lead, 

obtained scheelite, hubnerite, wolframite, and stolzite, respectively.

Wolframite is a frequent companion of tin ores, especially in 

greisen, the cassiterite and the tungsten minerals -having developed 

in much the same way. In the Cornish tin mines wolframite is an 

annoying impurity, and it also occurs, according to J. D. Irving,7 in 

the Etta tin district of the Black Hills. Near Lead City, in the same 

region, however, Irving found wolframite in magnesian limestone, 

where it had apparently been formed by metasomatic replacement. 

This occurrence was secondary, the primary wolframite being found 

in quartz veins cutting granite rocks. At Osceola, Nevada, hubnerite 

is abundant, with some scheelite, in veins of white quartz in a porphyritic granite.8 The tungsten- deposits of the Dragoon Mountains, 

Arizona, are of the same character,9 the ore being principally hubnerite, with scheelite and some wolfram. The tungsten mine at Trumbull, Connecticut, where wolframite, scheelite, and tungstic ocher are 

found, has been described by A. Gurlt 10 and W. H. Hobbs.11 In the 

Sierra de Cordoba, Argentina, according to G. Bodenbender, 12 the

1 Wolframite is hardly to be regarded as a definite species. It is really a mixture of ferberite and 

hiibneritc.

I Licbig's Annalen, vol. 81,1852, p. 243.

3 Cited by L. Bourgeois, Reproduction artificielle des mineraux, p. 172.

4 Compt. Rend., vol. 55,1862, p. 287.

6 Liebig's Annalen, vol. 120,1861, p. 270. 

«Bull. Soc. min., vol. 2,1879, p. 142.

7 Trans. Am. Inst. Min. Eng., vol. 31,1901, p. 683. Seealso J. D. Irving and S. F. Emmons, Prof. Paper 

U. S. Geol. Survey No. 26,1904, p. 163.

s See F. B. Weeks, Twenty-first Ann. Rept. U. S. Geol. Survey, pt. 6,1901, p. 319, and F. -D. Smith, 

Eng. and Min. Jour., vol. 73,1902, p. 304.

9 See W. P. Blake, Trans. Am. Inst. Min. Eng., vol. 28,1898, p. 543, and F. Rickard, Eng. and Min. Jour., 

vol. 78,1904, p. 263.

"> Trans. Am. lust. Min. Eng., vol. 22,1893, p. 236.

II Twenty-second Ann. Rept. U. S. Geol. Survey, pt. 2,1902, p. 13.

iiZeitschr. prakt. Geologic, 1804, p. 409. On the tungsten ores of Colorado, see W. Lindgren, Econ. 

Geology, vol. 2,1907, p. 453, and R. D. George, First Rept. Colorado- Gccl. Survey, 1908, p. 7. On tungsten, 

deposits in the Cocur d'Alene region, Idaho, see H. S. Auerbach, Eng. and Min. Jour., vol. 86,1908, p. 1146.
METALLIC ORES. 707

wolframite is again in quartz veins in granite, and molybdenite is 

sometimes present also. These illustrations of tungsten occurrences 

are ample for present purposes.

On the genesis of tungsten ores there is a recent paper by R. H. 

Rastall/ who has studied the subject from all points of view. The 

common association of wolfram with cassiterite in granite or pegmatite 

he regards as of magmatic origin. Scheelite is often a product of the 

contact between such granite and limestone. Other modes of occurrence as in metalliferous veins are like those of its common associate, 

tin. For details the original memoir should'be consulted.

THE PLATINUM METALS.

The metals platinum, iridium, osmium, palladium, rhodium, and 

ruthenium form a well-defined natural group of elements, which are 

found associated with one another, and in less degree with iron, 

nickel, chromium, etc. With two exceptions the platinum metals 

occur native, or in alloys, which vary much in composition, and have 

received many specific names. The two exceptions are laurite, 

ruthenium sulphide, RuS2 ; and sperrylite, platinum arsenide, PtAs2 . 

The native metals and recognized alloys are as follows:

Native platini.ua. 

Native iridium and platiniridium. 

Native palladium, isometric. 

Allopalladium, rhombohedral.

IridosminePevyanskite' over 40 per cent Ir> 

\Siserskite, 30 per cent Ir, or less.

Palladium gold.2 

Rhodium gold.

The list might be extended by subdivision, but the increase in 

names would be meaningless. The following selected analyses fairly 

represent the great variations in native platinum: 3

1 Ocol. Mag., 1918, pp. 193,241,293,367. Bull. U. S. Geol. Survey No. G52,1917, by F. L. Hess, is a useful 

summary of the occurrences of tungsten ores.

2 See section on gold, ante, p. G48.

s See J. F. Zemp, Bull. U. S. Geol. Survey No. 193,1902, for a full collection of analyses, bothof platinum and iridosmine. Other analyses by W. J. Martin, jr., appear in Sixteenth Ann. Rcpt. U. S. Geol. 

Survey, pt. 3,1895, p. 033. See also Dana's System of mineralogy, 6th cd., pp. 26, 27. Recent analyses of 

Uraliau platinum by L. Duparc and H. C. Holtz arc in Min. pet. Mitt., vol. 29, 1910, p. 498. 0. P. 

Merrill (Proc. Nat. Acad., vol. 1; 1915, p. 429) reports the presence of Pt, Pd, Ir, and Ru in meteorites. 

See also J. C. H. Mingaye (Rec. Gool. Survey New South Wales, vol. 9,1910, p. 159) on Pt, Pd, and Ir in 

Australian meteorites. 
708 DATA OF GEOCHEMISTRY.

Analyses of native platinum.

A. From Cboco, Colombia. Analysis by H. Sainte-Claire Deville and H. Debray, Annales chim. phys., 

3d ser., vol. 56,1859, p. 449.

B. From California. Deville and Debray.

C. Nugget found near Plattsburg, New York, of 54 per cent chromite and 46 per cent metallic platinum. 

Analysis of the platinum by P. Collier, Am. Jour. Sci., 3d ser., vol. 21,1-881, p. 123.

D. From Nizhni Tagilsk, Urals, Deville and Debray.

E. From Nizhni Tagilsk, blackish magnetic grains. Analysis by J. von Muchin (commonly but erroneously quoted as Minchin), cited, with other analyses, by N. von Kokscharof, Materialien zur Mineralogie 

Russlands, vol. 5,1866, p. 186.

F. Granite Creek, British Columbia. Nonmagnetic portion of sample. Analysis by G. C. Hoffmann, 

Trans. Roy. Soc. Canada, vol. 5, sec. 3, p. 17.

G. Magnetic portion of F. Analysis by Hoffmann.

H. From Condado, Minas Geraes, Brazil. Analysis by E. Hussak, Zeitschr. prakt. Geologic, 1906, p. 

284. For a paper by Hussak on platinum and palladium in Brazil, see Sitzungsb. Akad. Wien, vol. 113, 

Abth. 1,1904, p. 379.

Pt..................

Ir. ..................

Os.................

Pd. .................

Rh................

Au.................

Cu.................

Fe..................

A1803 ........ ......

Cab...............

MgO...............

Sand. ...............

Chromite ...........

A

86.20

.85

.50

1.40

1.00

.60

7.80

.95

.95

100. 25

B

85.50

1.05

.60

1.00

.80

1. 40

6.75

1.10

2.95

101. 15

C

82.81

.63

3.10

.29

.40

11.04

1.95

.07

.03

100. 32

D

76.40

4.30

1.40

.30

.40

4.10

11.70

.50

1.40

100. 50

E

68. 95

1.34

Trace.

.21

3.30

1,59

18. 93

3.75

98.07

F

68. ] 9

1.21

.26

3.10

3.09

7.87

14.62

1.95

100. 29

G

78.43

1.04

.09

1.70

3.89

9.78

3.77

1 97

99.97

H

72.96

88

Undet.

21.82

Undet.

Trace.

.42

96.08

In another sample of Uralian platinum, A. Terreil 1 found 0.75 

per cent of nickel. A remarkable nugget from the river Approuague, 

French Guiana, gave A. Damour 2 41.96 Pt, 18.18 Au, 18.39 Ag, and 

20.56 per cent Cu. This sample is altogether exceptional.

The subjoined analyses are of native iridium, platiniridium, and 

iridosmine.

i Compt. Rend., vol. 82,1876, p. 1116. s Idem, vol. 52, 1861, p. i
METALLIC ORES. 709

Analyses of native indium, etc.

A. Native iridium. Nizhni Tagilsk, Urals.

B. Platiniridium, probably from Brazil. Analyses A and B by Svanberg, Berzelius's Jahresb., vol*. 

15,1834, p. 205.

C. Iridosmine from Colombia.

D. Iridosmine from the Urals.

E. Iridosmine from the Urals. Analyses C, D, and E by Deville and Debray, Annales chim. phys., 3d 

ser., vol. 56,1859, pp. 481, 482.

Ir. .................................. pt........................ :..........

Os. .................................

Pd. ..................................

Rh. ................................

Ru .................................

Cu..................................

Fe........... ........................

A

76.80

19.64

.89

L 78

99.11

B

27.79

55. 44

Trace.

.49

6.86

3.30

4.14

98. 02

C

70.40

.10

17. 20

12.30

None.

100.00

D

77. 20

1.10

21. 00

.50

.20

Trace.

100. 00

E

43.94

14

48.85

1.65

4.68

.11

.63

100. 00

The indefinite character of these natural alloys seems to be perfectly evident.

The platinum and iridosmine of commerce are almost entirely from 

detrital or placer deposits, but their primary geologic affinities' are 

subsilicic. That is, the ores are associated with chromite and other 

products of the decomposition of peridotic rocks, from which they 

were undoubtedly derived. Chromite has been repeatedly observed 

adherent to or interpenetrating platinum nuggets, and A. Inostranzeff * has reported platinum in place in the dunite, or rather serpentine, of Mount Solovief in the Urals. On the Tulameen River, 

British Columbia, according to J. F. Kemp,2 the mother rock is also 

dunite, and grains of platinum are found with both chromite and 

olivine adhering to them. Even the serpentine of this region yields 

traces of platinum, upon careful assay. The black sands of the 

Pacific coast, from British Columbia southward to California, contain 

platinum, and also iridosmine, and their origin is peridotic.3 According to H. Bancroft,4 platinum is found in certain peridotite dikes in 

Clark County, Neva'da. On the other hand, L. Duparc, 5 who has 

devoted much study to Uralian platinum, reports its association 

with pyroxenite and gabbro.

 See English translation from the Russian in Bull. U. S. Geol. Survey No. 193, 1902, p. 76.

2 Bull. U. S. Geol. Survey No. 193,1902. A brief monograph on the geologic relations and distribution of 

platinum.

a See D. T. Day, Nineteenth Ann. Rept. U. S. Geol. Survey, pt. 6, 1899, p. 265. Also Day and R. H. 

Richards, Bull. U. S. Geol. Survey No. 285,1906, p. 150. In Trans. Am. Inst. Min. Eng., vol. 30, 1900, p. 

702, Day has a memoir on platinum in North America.

« Bull. U. S. Geol. Survey No. 430,1910, p. 192.

6 Aroh. Sci. phys. nat., 4th ser., vol. 30, 1910, p. 379; and vol. 31, 1911, p. 211. An earlier memoir by 

Duparc is in vol. 15, 1903, pp. 287, 377, which includes a bibliography of Uralian platinum. See also A. 

SaytzefT, Zeitschr. prakt. Geologie, 1898, p. 395; C. W. Purington, Trans. Am. Inst. Min. Eng., vol. 29,1899, 

p. 3; and R. Spring, Zeitschr. prakt. Geologie, 1905, p. 49.
710 DATA OF GEOCHEMISTRY.

A. Daubree, 1 many years ago, commenting upon the constant 

association of platinum with olivine rocks and chromite, pointed out 

the similarity of these rocks to meteorites. Much later, J. M. Davison 2 announced the presence of platinum and iridium in the meteoric 

iron of Coahuila. Still more recently, S. Meunier 3 -has discussed 

this relationship at some length, and argued that, contrary to the 

usual view, the native platinum and iron of these rocks are not magmatic, but are introduced as vaporized chlorides and subsequently 

reduced by heated hydrogen. This mode of introduction and deposition Meunier reproduced artificially, but the application of the 

experiments to meteorites is not quite clear.

In a number of cases platinum has been detected in sedimentary 

or metamorphic rocks. Kemp 4 mentions its occurrence in certain 

Pennsylvanian shales, and states also that the palladiuni gold of 

Brazil is sometimes associated with itabirite. E. Hussak 5 found 

palladium gold in a contact limestone, and reports the platinum of 

Brazil not only from olivine rocks, but also from a conglomeritic 

quartzite. According to J. B. Jaquet,0 platinum occurs near Broken 

Hill, Australia, in ironstone, ferruginous claystone, and decomposed 

gneiss. It is also said to be present in the ash of certain Australian 

coals.7 F. Sandberger 8 identified platinum hi limonite nodules from 

Mexico. In an altered limestone lens in Sumatra, L. Hundeshagen 9 

found platinum up to 6 grams per metric ton. The metal was in 

wollastonite, which formed from 85 to 88 per cent of the rock, with 

12 to 14 per cent of grossularite. Hundeshagen regards this occurrence as due to the introduction of hot solutions containing gold, 

silver, and platinum into the metal-bearing rock. Natural solutions 

of platinum, however, do not appear to have been observed; and its 

solubility in natural solvents is undetermined. Possibly the platiniferous quartz from the south island of New Zealand, described by 

J. B. Bell,10 had a similar origin. The quartz veins, however, were 

near altered magnesian eruptives, in which no platinum was found.

The occasional presence of platinum in sulphide ores has long been 

known, although it has attracted serious attention only within recent 

years. E. Gueymard 11 found it in tetrahedrite, in a gangue of dolo1 Compt. Rend., vol. 80,1875, p. 707.

2 Am. Jour. Sci., 4th ser., vol. 7,1899, p. 4.

s Compt. Rend. VII Cong. gool. internal., 1S97, p. 157.

< Bull. U. S. Geol. Survey No. 193,1902.

& Zeitschr. Kryst. Min., vol. 42,1906, p. 399.

6 Rec. Geol. Survey, New South Wales, vol. 5,1896-1898, p. 33. See also J. C. H. Mingaye, Ann. Rept. 

Dept. Mines, New South Wales, 1889, p. 249.

i See Seventeenth Ann. Rept. 17. S. deal. Survey, pt. 3,1896, p. 282.

s Neues Jahrb., 1875, p. 625.

»Trans. Inst. M^n. and Met., vol. 13,1903-4, p. 550.

w Econ. Geojlogy, vol. 1,1900, p. 749.

11 Compt. Rend., vol. 29, 1849, p. 814. See also Gueymard, Bull. Soc. g(5ol. France, 2cl s3r., vol. 12, 

7854-55, p. 429, on other occurrences of platinum in the Alps.
METALLIC ORES. 711

mite, quartz, and barite, at Chapeau Mountain, in the French Alps. 

The country rock was a metamorphic limestone. H. Rossler 1 detected both platinum and palladium in silver bullion; and H. Vogel a 

reports its presence in the metallic ores of Boitza, Transylvania. 

Much more striking, however, is the presence of platinum in the 

sulphide ores of Sudbury, Canada. Here it is found as the arsenide, 

sperrylite,3 associated with nickeliferous pyrrhotite and chalcopyrite, 

but most intimately with the latter. F. W. Clarke and C. Catlett,4 

however, showed its presence in massive polydymite. At the Rambler mine, in Wyoming, both platinum and palladium are found in 

covellite, in ores derived from diorite.5 Here, also} sperrylite has 

been identified.0 At this locality palladium appears to be more 

abundant than platinum, but its mode of combination is as yet undetermined. Sperrylite has furthermore been found by J. Catharinet 7 

in the pegmatite of Copper Mountain, British Columbia. One small 

crystal was embedded in biotite. Platinum is also present, according 

to C. W. Dickson,8 in chalcopyrite from the Key West mine, Bunkerville, Nevada; but sperrylite could not be detected. J. H. L. Vogt ° 

found platinum to be present in the nickeliferous pyrrhotites of Norway, and R. W. Brock 10 discovered traces of it in sulphide-bearing 

quartz at the Mother Lode claim, Yale district, British Columbia. 

These occurrences have led to much searching after platinum in 

copper and nickel ores, and the search is likely to be occasionally 

fruitful.11 The presence of platinum in sulphide ores near Broken 

Hill has been reported by J. C. H. Mingaye.12 In plumbojarositc 

from Goodsprings, Nevada, R. C. Wells 13 found up to 0.2 per cent 

of palladium, with a trace of platinum.

1 Licbig's Annalen, vol. 180,1875, p. 240.

2 Ocstcrr. Zeitschr. Berg- u. Huttenw., vol. 39, p. 32.

<> See H. L. Wells, Am. Jour. Sci., 3d ser. r vol. 37,1889, p. 67. Sperrylite lias since been found by W. E. 

Hidden (idem, 4th se'r., vol. G, 1898, p. 381), and by Hidden and J. H. Pratt (idem, vol. 6,1898, p. 467), at 

two localities in North Carolina, associated with rhodolite garnet. For details concerning Sudbury, seo 

the section on nickel and cobalt, ante, p. 700.

4 Bull. U. S. Geol. Survey No. 64,1890, p. 20.

6 See W. C. Knight, Eng. and Min. Jour., vol. 72,1901, p. 845; vol. 73,1902, p. 696; J. F. Kemp, Cent. 

Geol. Dept. Columbia Univ., vol. 11, No. 93,1903; S. F. Emmons, Bull. U. S. Gcol. Survey No. 213,1903, 

p. 94; and T. T. Read, Eng. and Min. Jour., vol. 79,1905, p. 985.

s H. L. Wells and S. L. Penfield, Am. Jour. Sci., 4th ser., vol. 13,1902, p. 85.

7 Eng. and Min. Jour., vol. 79,1905, p. 127.

8 Jour. Canadian Min. Inst., vol. 8, 1905, p. 192. Memoir on the distribution of the platinum metals 

in other sources than placers. On platinum and palladium in blister copper, see A. Eilers, Buli. Am. 

Inst. Min. Eng., No. 78,1913, p. 999. In graywacke, T. Krusch, Metall u. Erz, vol. 11,1914, p. 545. 

0 Zeitschr. prakt. Geologic, 1902, p. 258.

1(> Eng. and Min. Jour., vol. 77,1904, p. 280.

11 According to W. Baragwanath (Bull. Geol. Survey Victoria, No. 20,1906), platinum is found in the 

Thomson River copper mine in a hornblende rock rich in chalcopyrite.

!2 Rec. Geol. Survey New South Wales, vol. 8,1909, p. 287, and vol. 9,1916, p. 127.

" Work done in the laboratory of the U. S. Geological Survey. On the Goodsprings deposit, seo A. 

Znopf, Bull. U. S. Geol. Survey No. 620-A, 1915, and L. A. Palmer, Min. Eng. Jour., vol. 102,1910, p. 123.
712 DATA OF GEOCHEMISTKY.

VANADIUM AND URANIUM.

Although vanadium and uranium are chemically unlike, they occur 

together in one of their important ores, and are therefore considered 

together in this section. Vanadium is a member of the phosphorus 

group of elements; uranium is more akin to molybdenum and tungr 

sten, and the two metals are also magmatically opposed. Vanadium 

is most common in ferromagnesian rocks, while uranium minerals 

occur more frequently in granites and pegmatites.

Vanadium is reckoned among the rarer elements, and yet it is 

widely diffused. Traces of it are common in iron ores, especially in 

the titaniferous magnetites, and it is found, when sought for, in rocks 

of nearly every class.1 W. F. Hillebrand,2 in a special investigation, 

examined 57 igneous rocks, and found vanadium, in most cases, in 

weighable proportions. The smallest traces were in persilicic rocks, 

but in subsilicic varieties the amount, reckoned as V203, frequently 

ran as high as 0.03 to 0.05 per cent. In the ferromagnesian minerals 

separated from some of the rocks the proportion of vanadium was 

even higher, in one biotite, for example, reaching 0.127 per cent of 

V2O3 . Hillebrand also found vanadium in slates and in other sedimentary rocks. A composite of 253 sandstones gave 0.003, and 

another of 498 limestones gave 0.004 per cent of vanadious oxide.

H. Sainte-Claire Deville 3 found vanadium in French bauxite, in 

cryolite, and in rutile. P. Beauvallet 4 detected it in a French clay. 

In bricks made from a clay found near Sydney, Australia, according 

to E. H. Rennie,5 vanadium is present to a perceptible amount. 

Other Australian clays and shales gave J. C. H. Mingaye 6 similar 

results. He also found vanadium in the ash of coals and in the oilbearing shales of Scotland. E. Bechi 7 reports vanadium in clays, 

schists, and the ashes of plants,8 and C.. Baskerville ° found it in the 

ashes of peat from North Carolina. A. Jorissen 10 discovered it in 

delvauxite, which is a hydrous phosphate of iron.

i See A. A. Hayes, Proc. Am. Acad. Arts and Sci., vol. 10,1875, p. 294. Hayes found vanadium in many 

rocks, and also in the waters of Brookline, Mass. Arsenic and vanadium have been detected in 

the underground waters of Bell-Ville, Argentina. See A. A. Bado, Bol. Acad. Nac. Ciencias, Argentina, 

vol. 23, pt. 1,1918, p. 85. For determinations of vanadium in lavas of Vesuvius and Etna, see L. Ricciardi, 

Gazz. chim. ital., vol. 13,1883, p. 259. Scattered determinations are numerous.

a Bull. U. S. Geol. Survey No. 167,1900, p. 49. See also J. H. L. Vogt, Zeitschr. prakt. Geologic. 1899, 

p. 274, on the distribution of vanadium in rocks. W. Pollard (Summ. Prog. Geol. Survey Great Britain,. 

1902,p. 60) has found vanadium in a number of rocks. On vanadium in the Stassfurt salt clay see E. Marcus. 

and W. Biltz, Zeitschr. anorg. Chemie, vol. 68,1910, p. 91.

a Annales chim. phys., 3d ser., vol. 61,1861, pp. 309,342. See also L. Dieulafait, Compt. llend., vol. 93,, 

1881, p. 804.

4 Compt. Rend., vol. 49,1859, p, 301.

s Proc. Roy. Soc. New South Wales, vol. 17,1SS3, p. 133. He cites similar exam pies from other authorities.

e Rec. Geol. Survey New South Wales, vol. 7,1903, p. 219.

' Atti R. accad. Lincei, 3d ser., vol. 3,1S79, p. 403.

8 See also E. Demargay, Cornpt. Rend., vol. 130,1900, p. 91.

9 Jour. Am. Chem. Soc., vol. 21,1S99, p. 706.

"0 Annales Soc. g6ol. Belgique, vol.. 6,1878-79, p. 41.
METALLIC ORES. 713

A still more remarkable occurrence of vanadium was noted by J. J. 

Kyle 1 in a lignite from San Raf ael, Province of Mendoza, Argentina. 

The coal yielded only 0.63 per cent of ash, but the latter, upon analysis, was found to contain 38.22 per cent of V205 , together with silicates and sulphates of other metals. In a similar coal, probably 

from the same region, A. Mourlot 2 obtained 38.5 per cent of V2 0s 

from the ash; and in another, from Yauli, Peru, Torrico y Meca 3 

discovered 38 per cent. .The ash of a grahamite from near Page, 

Oklahoma, analyzed in the laboratory of the United States Geological Survey by R. C. Wells, contained 12.2 per cent of V205 . 

In the ash of an asphalt from Nevada the same chemist found nearly 

30 per cent, and in the ash of Trinidad manjakB. Salkover found 0.52 

per cent of vanadium. These ash analyses, taken together with the 

finding of vanadium in the ashes of wood and peat, suggest that plants 

have played some part in the concentration of vanadium. Other 

evidence of similar purport will be cited later.

The definite minerals containing vanadium as an. essential constituent are not very numerous. Some of them, vanadates of lead, 

such as vanadinite and descloizite, were mentioned .in a previous 

section of this chapter. Volborthite and calciovolborthite are vanadates of copper, with other bases, and pucherite is a yanadate of bismuth. Mottramite, a vanadate of copper and lead, found at Alderley 

Edge, in England, has had some significance as a workable ore. It 

occurs as an impregnation in Keuper sandstone.4 A Mexican variety 

of descloizite, ramirite,5 has also been commercially exploited. These 

vanadates, with the exception of mottramite, occur principally in 

metalliferous veins; and A. Ditte 6 attributes their formation to 

percolating vanadiferous waters acting on other compounds, most 

commonly the compounds of lead. The so-called vanadic ocher is 

doubtful.

A sulphovanadate of copper, sulvanite, Cu3VS4 , is found in South 

Australia.7 At Minasragra, near Cerro de Pasco, Peru, another sulphide of vanadium, patronite, is found, associated with pyrite, in a 

carbonaceous substance resembling a coal but abnormally rich in 

sulphur.d This occurrence may well be correlated with the other 

discoveries of vanadium in the ash of coal; and the sulphates, equiva1 Chem. News, vol. 66,1892, p. 211.

2 Compt. Rend., vol. 117,1893, p. 546.

3 Abstract from a Peruvian original, in Jour. Chem. Soc., vol. 70, pt. 2,1896, p. 252. For more details, 

see D. F. Hewett, Bull. Am. Inst. Min. Eng., 1909, p. 291.

4 See H. E. Koscoe, Proc. Roy. Soc., vol. 25,1876, p. 111.

6 Sce'G. de J. Caballero, Mem. Soc. cient. Ant. Alzate, vol. 20,1903, p. 87.

6 Compt. Rend., vol. 138,1904, p. 1303.

' See O. A. Goyder, Jour. Chem. Soc., vol. 77,1900, p. 1094.

a See D. F. Hewett, Eng. and Min. Jour., vol. 82, 1908, p. 385; and J. J. Bravo, Inform, y Mem. Bol. 

Sec. Ingen. minas, Lima, vol. 8, 1906, p. 171. For a later and much more complete description of tho 

sulphide, patronite, and its associated minerals, see W. F. Hillebrand, Am. Jour. Sci., 4th ser., vol. 24, 

1907, p. 141. Thebituminous matrix he names quisqueite.
714 ' DATA- OF-G-EOC-HEMISTRY.

lent to 13.70 per cent of S03 , found by Kyle in his analysis, may-show 

tliat he too had originally a sulphide to deal with which was oxidized 

during combustion. Associated with and derived from patronite are 

the calcium vanadates hewettite, pascoite, and fernandinite, a vanadium sulphate, minasragrite, and other alteration products.1

The rare mineral ardennite is a vanadio-silicate of manganese and 

aluminum. Roscoelite appears to be essentially a muscovite in which 

vanadium has partly replaced aluminum.2 It contains about) 24 

per cent of V203 . In a green sandstone from Placerville, Colorado, 

W. F. Hillebrand 3 found 3.50 per cent of V203 , which was present in 

a replacement of the original calcareous cement. The green mineral, 

isolated, contained 12.84 per cent of V203 and was apparently a 

variety of roscoelite, or else a closely related compound.

The metal uranium is much less abundantly diffused than vanadium. It is found in a number of rare minerals phosphates, arsenates, sulphates, carbonates, and silicates which are all of secondary 

origin. Autunite, a phosphate of uranium and lime, is not uncommon in the form of yellow scales on granite or gneiss, but the other 

species are much less frequently seen. A number of other minerals, 

samarskite, euxenite, etc., are columbates or tantalates containing 

uranium, and these are primary constituents of pegmatite.

The only uranium ores of any importance are uraninite or pitchblende and carnotite. Uraninite is found crystallized in pegmatites, 

and also massive hi metalliferous veins, as at Joachimsthal,4 in 

Bohemia, and Johanngeorgenstadt, in Saxony. It varies much in composition, so much so that different modifications of it have received 

different names, such as cleveite, nivenite, broggerite, etc. The following analyses, by W. F. Hillebrand, 5 will serve to illustrate the 

variations.

' On hewettite and pascoite see W. F. Hillebrand, H. E. Menvin, and F. E. Wright, Proc. Am. Philos. 

Soc., vol. 53,1914, p. 31. The two other species are described by W. T. Schaller, Jour. Washington Acad* 

Sci., vol. 5,1915, p. 7.

2 Bull. U. S. Geol. Survey No. 167,1900, p. 73.

s Bull. U. S. Geol. Survey No. 262,1905, p. 18.

< On tho Joachimsthal ores, see Janda, Oesterr. Zeitschr. Berg- u. Hiittenw., vol. 50, p. 283; also J. Step 

and F. Becke, Zeitschr. prakt. Geologic, 1905, p. 148. R. Pearce (Proc. Colorado Sci. Soc., vol. 5, 1895, 

p. 156) has described the occurrence of uraninito in a mine near Central City, Colorado. On uranium ores 

in German East Africa, seo W. Marckwald, Centralbl. Min., Geol. u. Pal., 1906, p. 761.

6 Seo Bull. U. S. Geol. Surrey No. 78,1891, p. 43, and No. 90,1892, p. 23, for details; also Bull. No. 220, 

1903, pp. 111-114. 22 analyses in all are given. On the pitchblende of Joachimsthal seo R. Jaffe, Zeitschr. 

prakt. Geologic, 1912, p. 425.
METALLIC ORES. 715

Analyses ofuraninite.

A. Hale's quarry, Glastonbury, Connecticut. 

B. Near Central. City or Blackhawk, Colorado. 

C. Johanngeorgenstadt, Saxony.

D. Nivenitc, Llano County, Texas. 

E. Broggerite, Annerod, Norway. 

F. Cleveite, Arcndal, Norway.

uo............................

uo-.. ............... ..........

Th02 .. .............. ..........

CeOa... ......................

Zr02 . ........................

(La, DiU)3 ...................

(Yt,Er)203 ... ................

A1 203 .. ......................

Fe203 . .......................

Feb..........................

PbO.. ........................

ZnO.........................

CuO.........................

MnO.........................

CaO...........................

MgO.........................

BiA--- ....... .:'.. ..........

V205 , Mo03 , W03 .. ............

Alkalies. .....................

SO.......................... p6

AfljO,.. ........ ...............

He...- .. ......................

H20. .........................

Si02 .........................

CuFeS.............. .............

FeSo..... ....................

Insoluble. ....................

A

2G.48

57. 43

9.79

.25

.13

.20

. 40

3. 26

Trace.

.08

Trace.

Undet.

.61

.16

.70

99.49

B

25. 26

58.51

.22

7.59

.32

.70

.44

. .1.6

.84

Trace?

Trace?

.22

.43

.02

1.96

2.79

.12

.24-

99.82

c

'22.33

59.30

1ST rin P

None.

None.

.20

21

6.39

.17

.09

1.00

.17

.75

.75

.31

.19

.06

2.34

Trace.

3.17

.50

97.93

D

20.89

44. 17

6.69

.34

.34

2.36

9.46

.14

10.08

.32

.08

1.48

.46

1.47

98. 28

E

30. 63

46. 13

6.00

.18

.06

.27

1. 11

.25

9.04

.37

Trace.

.02

.17

.74

.22

4.42

99. 61

F

41. 71.

24. 18

 3. G6

0.76

.03

10. 54

1:06

.10

.23

Undet.

1.23

.90

1.10

94. 50

From these analyses no single definite formula can be deduced. 

The uranium, it is clearly seen, exercises a double function, acid and 

basic, the latter being represented by the radicle uranyl, U02 . With 

this base other bases are variably present thoria, zirconia, the rare 

earths, and oxide of lead, sometimes one and sometimes another predominating. There are also impurities of several kinds which can 

not be clearly distinguished from essential constituents, and some of 

the variations may be due to incipient alterations. For example, the 

varying ratios between U02 and U03 may be ascribed to oxidation, 

the increase in U03 marking stages in the process of transformation 

of uraninite into gummite, a well-known alteration product of pitchblende. In gummite, which is a hydrous oxide of uranium 1 plus 

other bases, with from 61 to 75 per cent of U03 , the final transformation of uraninite is seen.

From a physical point of view uraninite is an extraordinary mineral. In it helium was first discovered, and later the radioactive 

elements polonium and radium. Uranium and its compounds are 

themselves radioactive, but radium is vastly more so; and the latter,

1 For analyses of gummite, see H. von Foullon, Neues Jahrb., 1885, pt. 1, Ref., p. 21, and F. A. Oonth, 

Am. Chem. Jour., vol. 1,1879, p. 89.
716 DATA OF GEOCHEMISTRY.

while distinctly an element so far as its chemical characteristics are 

concerned, undergoes disintegration, yielding a series of emanations 

which seems to end in the production of helium. Radioactivity, then, 

appears to be a phenomenon of atomic decay; but the subject is one 

which hardly falls within the scope of this treatise. For the present 

it is enough to say that the chief sources of radium to-day are in the 

uraninite of Joachimsthal and in carnotite, and that uranium itself 

is the progenitor of its more highly active companion.

Carnotite, which is essentially a vanadate of uranium and potassium, but with other bases present also, was first described by C. 

Friedel and E. Cumenge.1 It is found as a canary-yellow impregnation in sandstone in western Colorado and eastern Utah. The former 

field has been studied by W. F. Hillebrand and F. L. Ransome,3 

the latter by J. M. Boutwell.3 An outlying region for carnotite in 

Rio Blanco County, Colorado, has also been described by H. S. Gale.4

The following analyses of carnotite, by Hillebrand, will show its

general character:

Analyses of carnotite.

A. Copper Prince claim, Roc Creek, Montrose County, Colorado.

B. Yellow Boy claim,-La Sal Creek, Montrose County. . . .

uo,.. ............................................... .......... v&.. ................. ........................................

P O

As205 . ........................................................

Al O

FeA ....................................................

OaO ...........................................................

SrO............................................................

BaO. ..........................................................

MgO... ........................................................

K20..........................................................

Na20 ..........................................................

LL.O... ........................................................

H

"o

H20+....... .......... ................................ .......

PbO.............. :................................:.... ......

CuO... ........................................................

Mo03 .........................................................

Si02 .. .........................................................

TSO

rn

A 

54.89

18.49 ".80

Trace.

.09

.21

. 3.34

.02

.90

.22

6.52

.14

Trarp

2.43

2.11

.13

.15

.18

.15

.03

.56

7.10

98.46

B

54.00

18.05

.05 "Wrt'np

.29

49

1.86

TTOPP

2.83

.14

K. 4fi

.13

Trace.

3.16

2.21

.07

Trace.

05

.20

ir?) W one

10.33

99.25

1 Compt. Rend., vol. 128,1890, p. 532. Tyuyamunite, a recently described mineral, is a calcium carnctite, originally from Siberia but also found in Utah.

2 Bull. U. S. Geol. Survey No. 262,1905, p. 9.

3 Bull. U. S. G-eol. Survey No. 260,1904, p. 200.

« Bull. U. S. Geol. Survey No. 315,1907, p. 110. Gale (Bull. 340,1908, p. 258) has also described carnotite 

from Routt County, Colorado. See also H. Fleck and W. G. Haldane (Rept. State Bur. Mines, 1905-6, p. 

47) on the uranium and vanadium deposits of southern Colorado. Bull. U. S. Bureau of Mines No. 70, by 

R. B. Moore and K, L. Kithil, is essentially a monograph on the ores of vanadium and uranium. The 

Colorado ores are now being worked as a source of radium. On carnotite from Mauch Chunk, Pennsylvania, see E. T. Wherry, Am. Jour. Sci., 4th ser., vol. 33,1912, p. 574. On vanadium deposits in Colorado, 

Utab,and Mexico, see F. L. Hess, Bull. U. S. Geol. Survey No. 530,1913, pp. 142,157,101.
METALLIC ORES. 717

With the carnotite a vanadiferous silicate also occurs, which may 

be akin to roscoelite. Two calcium vanadates, metahewettite and 

pintadoite, and a vanadate of uranium, uvanite, are also present.1

In the Utah field, as described by Boutwell, not only carnotite, but 

other vanadates, such as calciovolborthite, are found. In Wildhorse 

Canyon a black, carbonaceous sandstone also occurs, in which vanadium is present. This recalls the occurrences of vanadium in coals 

elsewhere. In the San Rafael Swell the carnotite is found principally 

on or near the fossil remains of plants, whose organic matter, Boutwell suggests, may have acted as precipitants of vanadium. The 

same association with fossil wood was also noted by Gale. No sulphide of vanadium, however, like that of Peru, has yet been identified 

in this region. Carnotite has also been reported by D. Mawson 2 in 

the pegmatite of "Radium Hill," South Australia.

In some experiments upon the formation of tnese ores F. B. 

Notestein 3 has shown that both uranium and vanadium are precipitated from sulphate solutions by calcite. Their common association with gypsum is explained by this reaction.

Uranium, like vanadium, has been found in coal. In an anthracitic bitumen from Sweden, described by A. E. Nordenskiold,4 the 

ash contained about 3 per cent of U308, with some nickel oxide and 

rare earths. In the ash of Swedish "kolm," a bituminous coal, H. 

Liebert,5 working in C. Winkler's laboratory, found from 1.68 to 2.87 

per cent of U308 . An anthracitic mineral from a pegmatite vein in 

the Saguenay'district, Canada, yielded J. Obalski 6 2.56 per cent of 

uranium, equivalent to 35.43 per cent in the ash. The significance 

of these occurrences remains to be determined.

COLUMBITJM, TANTALUM, AND THE RARE EARTHS.

A striking feature in the recent development of chemical industries has been the utilization of rare elements which previously had 

only scientific interest. The invention of incandescent gas lighting 

has created a demand for several of these substances, and that reason 

alone is enough to justify their brief consideration here.

Columbium 7 and tantalum are acid-forming elements, whose 

typical oxides have the formulae Cb2O5 and Ta2O5 . They enter into 

the composition of a considerable number of minerals, which are

1 On ractahewcttite see Hillcbrand, Merwin, and Wright, loc. cit. The two other species are described 

by F. L. Hess and W. T. Schaller, Jour. Washington Acad. Sci., vol. 4, 1914, p. 576. On the origin of 

carnotito see Hess, Econ. Geology, vol. 9,1914, p. 675.

2 Trans. Eoy. Soc. South Australia, vol. 30, 1906, p. 188.

3 Econ. Geology, vol. 13,1918, p. 50. 

* Compt. Rend., vol. 116, 1893, p. 677. 

« Seo C. Winkler, Zeitschr. Kryst. Min., vol. 37,1903, p. 287. 

» Jour. Canadian Min. Jjist., vol. 7, 1904, p. 245.

7 Known In Germany as niobium. The name columbium has more than 40 years' priority and refers to 

the original discovery of the element in a mineral from America. Niobium is ctymologically meaningless.
718 DATA OF GEOCHEMISTRY.

found principally in pegmatites. Among these, coiumbite, tantalite, 

samarskite, and euxenite are by far the most important. Coiumbite 

and tantalite are salts of iron, FeCb2 06 and FeTa2 08, which commonly occur more or less isomorphously commingled, often with 

manganese partly replacing the iron. Metallic tantalum1 has recently 

been utilized as a substitute for the carbon filament in incandescent 

electric lights, and tantalite is the chief source from which it can be 

obtained.2 The supply so far is mainly from Scandinavian localities.

Zirconium and thorium are tetrad metals forming oxides of the 

type R02 . They also are found in granitic rocks, and zirconium 

compounds are almost always present in. nepheline syenites. The 

chief zirconium mineral, zircon, ZrSi04 , has already been described 

in the chapter upon rock-forming minerals. The mineral baddeleyite, found in Ceylon and Brazil, is the oxide, Zr02 . Eudialyte, catapleiite, and the zircon-pyroxenes are complex silicates containing 

zirconia. Zircon syenite and eudialyte syenite are rare but wellknown rocks, and zircon also occurs, though not commonly, in contact limestones. The most remarkable American locality for zircon 

is near Green River, in Henderson County, North Carolina, where 

it is found abundantly in a decomposed pegmatite dike. From this 

source many tons of zircon have been obtained.

The typical thorium mineral is also a silicate, thorite, ThSi04. 

The ideal species, however, has not been found, for the actual specimens are always more or less altered. The chief source of thoria, 

which is used in the manufacture of mantles for incandescent gasburners, is from monazite sand, in which the thorium compounds 

exist as variable impurities. Thoiianite, a thorium-uranium oxide 

from Ceylon, is noteworthy for being richer in helium than any 

other known mineral. Like uranium,, thorium is strongly radioactive, and so are its compounds.3

In the group of elements known as the metals of the rare earths, 

the following members have been identified: Scandium, yttrium, 

lanthanum, cerium, praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, erbium, thulium, holmium, 

lutecium, and ytterbium. Among these yttrium and cerium may be 

regarded as the type elements, and they are, moreover, the most 

important. In the mineral kingdom these substances occur in a 

large number of compounds fluorides, carbonates, silicates, phosphates, columbates, and tantalates, minerals which are found, like 

the other species mentioned in this section, principally in granites, 

gneisses, and pegmatites.

1 Nativo tantalum has been reported from two localities in Siberia by T. "Walthcr, Nature, 1909, p. 335, 

and W. von John, idem, 1910, p. 398.

2 Sec Wcrncr von Bolton, Zeitschr. angcw. Chcmic, 1906, p. 1537.

s For an elaborate paper on the occurrence of thorium in the mineral kingdom, see J. Schilling, Zeitschr. 

angw. Chemie, 1902, p. 8C9.
METALLIC ORES. 719

Cerium, which is always accompanied by lanthanum, neodymium; 

and praseodymium, is obtainable principally from three minerals 

which are found in reasonably large quantities. Cerite, a hydrous 

silicate of these elements, forms a bed in gneiss at Bastnas, Sweden. 

It was for a long time the only commercial source of cerium compounds. . Allanite, a more complex silicate of cerium, aluminum, and 

'other bases, is also abundant enough to be an available ore. It is 

not a very rare mineral, and a notable locality for it is on Little 

Friar Mountain, Amherst County, Virginia.1 Allanite has also been 

found associated with iron ores, as, for example, with the magnetite 

of Moriah, near Lake Champlain.

Monazite, the phosphate of cerium, which is normally CeP04 , is, 

however, the chief source of the cerium earths at the present day. 

It is obtained for commercial puiposes from detrital deposits of 

monazite sand,2 and yields both cerium and thorium compounds. 

Monazite, the allied yttrium phosphate, xenotime, and allanite have 

all been adequately considered in the chapter upon rock-forming 

minerals. The following analyses of monazite are by S. L. Penfield: 3

Analyses of monazite.

A. From Portland, Connecticut. B. From the sands of Brindlctown, North Carolina. C. From 

Amelia Court House, Virginia.

P 0

Ce 0

(La. Dij ,63 - . .......................................... Th6,. .:..J..... ....................................... sio2 : .................................................

A

28.18

38.54

28.33

8.25

1.67

.37

100. 34

B

29.28

31. 38

30.88

G.49

1.40

20

99.63

C

26. 12

29. 89

2fi. 66

14. 23

2.85

.67

100. 42

Yttria and its companions, erbia, terbia, ytterbia, etc., are obtained 

for the most part from gadolinite, Gl2FeYt2Si2O10 . These oxides, 

therefore, are sometimes called the "gadolinite earths." The type 

locality for this species is Ytterby, in Sweden, and other Swedish 

localities have yielded the mineral. A more remarkable occurrence 

of gadolinite and other allied minerals is at Baringer Hill, Llano 

County, Texas. Here, in a giant pegmatite containing enormous 

crystals of quartz and feldspar, gadolinite is found in large crystals,

1 See J. W. Mallet, Am. Jour. Sci., 3d ser., vol. 14,1877, p. 397.

2 On the monazito sand of North Carolina; see H. B. C. Nitzc, Bull. North Carolina Gool. Curvcy No. 9, 

1398. Also the references on p. 356, ante. Nitzc cites 37 anal3rscs of monazite. On ir.onazite sand in tho 

tin-bearing alluvium of the Malay Peninsula, sec Bull. Imp. Inst., vol. 4,1CC6, p. SCI.

* Am. Jour. Sci., 3d ssr., vol. 24, 1882, p. 250. Tho symbol Di represents tho eld didymium, v/hich is 

now known to bo a mixture of neodymiurn, praso'jdyrrau:n, samarium, etc.
V 

720 DATA OF GEOCHEM1STBY. t

together with yttrialite, thorogummite, nivenite, fergusonite, allanite, 

tengerite, cyrtolite, ro.wlandite, mackintoshite, and yttrocrasite. 

Several of these species and varieties are peculiar to this locality.1

i See W. E. Hidden and J. B. Mackintosh, Am. Jour. Sci., 3d ser., vol. 38, 1889, p. 474; Hidden, idem, 

vol. 42,1891, p. 430; Hidden and W. F. Hillebrand, idem, vol. 46,1893, pp. 98, 208; Hillebrand, idem, 4th 

ser., vol. 13,1902, p. 145; Hidden, idem, vol. 19,1905, p. 425; Hidden and C. H. Warren, idem, vol. 22,1906, 

p. 515.
CHAPTER XVI.

THE NATURAL HYDROCARBONS. ^

COMPOSITION.

Natural gas, petroleum, bitumen, and asphaltum are all essentially 

compounds of carbon and hydrogen, or, more precisely, mixtures of. 

such compounds in bewildering variety. They contain, moreover, 

many impurities sulphur compounds, oxidized and nitrogenous sub-

- stances', etc. whose exact nature is not always clearly defined. The 

proximate analysis of a petroleum or bitumen consists in separating 

its components from one another, and in their identification as compounds of definite constitution.

All the hydrocarbons fall primarily into a number of regular series, 

to each of which a generalized formula may be assigned, in accordance

vu with the following scheme:

1. C nH2n+2 . 6. C nH2n_8 .

2. C nH2n . 7. C nH2n_10 .

3. C,,H2n_2 . 8. C DH2n_12 .

4. C H _j. _ .

5. C nH2n_0 . 18. C nH2n_32 .

Members of the first eight series have been discovered in petroleum.

These expressions, however, have only a preliminary value, although

they are often used in the classification of petroleums. Each one

" represents a group of series homologous, isomeric, or polymeric, 

as the case may be and for precise work these must be taken separately. The first formula, for example, represents what are known

'' as the paraffin hydrocarbons, which begin with marsh gas or methane,

> -,-CH4 , and range at least as high as the compound C35H72 . Even these 

are again subdivided into a number of isomeric series the primary,

" secondary, and tertiary paraffins which, with equal percentage composition, differ in physical properties by virtue of differences of 

atomic arrangement within the molecules. Each member of the 

series differs from the preceding member by the addition of the

_ group CH2 , and also by the physical characteristics of greater condensation. Methane, CH4 , for example, is gaseous; the middle mem-

""* bers of the series are liquids, with regularly increasing boiling points; 

the higher members are solids, like ordinary paraffin. These hydrocarbons are especially characteristic of the Pennsylvania petroleums, 

from which the following members of the series have been separated. 1

 » i The table is condensed from H. Hofer's valuable work, Das Erdol, 2d cd., Braunschweig, 1906, pp. 58-59. 

A third edition appeared in 1912. A useful treatise on asphalts and allied substances is by H. Abraham, 

_ Now York, 1918. '

113750° 19 Bull. 695 46 721
722 DATA OF GEOCHEMISTRY.

Paraffins from Pennsylvania petroleum.

Name.

1. Gaseous:

Ethane. .............................

2. Liquid: 

Pentane ..............................

f^Jr*"t"on A

Nonane. ......... ....................

Decane. ..............................

Eiidecane. . ...........:..............

Dodecane ...........................

T1 !*! C\ flp£l Tl O

Tetradecane. .........................

Pentadecane. .........................

Hexadecaue. .........................

.3. Solid: 

Octodecane. . ........................

Pentatriacontane a . ....... \ ..........

Formula.

CH4 . ......

f1 TT

C

l-T

C TT 4M10 . ....

r L5TT U12 . - - - -

r\ TT C GH14 . ....

C7H10 . ....

C

Tl1

r\ C UHTJ24 .....

r C UTT H30 .....

r ft

r1 . TT

r TT

r TT

n L TT 29U60 .....

L31H64 .....

r C TT 34H70 .....

^35n72- 

Melting point.

°c.

-186

-172.1

- 51

- 31

- 26

- 12

_L 4

18

37

48

50-51

53-54 

55-56

60

62-83

66

67-68

71-72

76

Boiling point.

 °c.

^164

- 84.1

- 37

 + *

37

G9

f)R

125

150

173

195

214

252

a For a description of these, higher, solid paraffins, see C. F. Mabery, Am. Chem. 'Jour., vol. 33, 1905, p. 251. 

The literature of these substances is so voluminous that I can not attempt to give exhaustive references. 

C. Hell and C. Hagele (Ber. Deutsch. chem. Gesell., vol. 22, 1889, p. 504) have described an artificial hydrocarbon,

To this list the isomeric secondary paraffins isobutane, isopentane, 

isohexanc, isoheptane, and isooctane must be added, and even thcn 

the list is probably not . complete. For instance, the solid paraffins 

C27H56 and C30H62 have been found in petroleum,

Natural gas consists almost entirely of paraffins, mainly of methane, 

with quite subordinate impurities. In six samples from West Virginia, analyzed by C. D. Howard, 1 the total paraffins varied between 

94.13 and 95.73 per cent. Methane ran from 79.95 to 86.48 per cent 

and ethane from 7.65 to 15.09. In all but one of 41 samples of natural 

gas, mostly from Kansas and adjoining States, H. P. Cady and D. F. 

McFarland 2 found helium, from a trace up to 1.84 per cent, together 

with some argon and neon. E. Czako 3 also found helium in European gases. .

 

1 West Virginia Geol. Survey, vol. 1A, 1904, p. 550.

2 Kansas Univ. Geol. Survey, vol. 9, 1903, p. 228. See also Trans. Kansas Acad. Sci., vol. 20, 1907, p.. SO, 

and vol. 21, 1908, p. 04.

3 Dissertation, Tech. Hochschule, Karlsruhe, 1913. Also Zeitschr. anorg. Chcmic, vol. 82, 1913, p. 249.
THE NATURAL HYDROCARBON'S. 723

Analyses of natural gas .a

A. From Creighton, Pennsylvania.

B. From Pittsburgh, Pennsylvania.

C. From Baden, Pennsylvania.

D. From Vancouver, British Colubibia. Analyses A to D by F. C. Phillips, Am. Chem. Jour., vol. 1C, 

189-1, p. 400. Selected from a table of seventeen analyses to show extreme variations.

E. Mean of four gases from Indiana and three from Ohio, analyzed by C. C. Howard for the United States 

Geological Survey. Cited by W J McGco, Eleventh Ann. Ilept. U. S. Gcol. Survey, pt. 1,1891, p. 592.

F. From Osa\vatamie, Kansas. From a table of seven analyses by E. II. S. Bailey, Kansas Univ. 

Quart., vol. -I, 1S95, p. 1.

CH4 ...... ....................

C2H4 , etc..... ................

CO............................

CO............................ H,:................ ...........

N

"

H2S. ..........................

o.............. ;..............

A

96.36

3.64

pJmiP

ATrmp

NoTIG

100. 00

B

98.90

.40

.70

None

None

100. 00

c

87.27

.41

12.32

TVJ r>"HP

pJnnp

100. 00

D

93.56

.14

None.

6.30

1ST nn P

TVJ nil P

100. 00

E

93.36

.28

.53

.25

1.76

3.28

.18 '.29

99.93

F

97. 63

.22

1.32

.22

.60

T vi r*p

100. 00

a Sec also C. F. Mabery. Am. Chem. Jour., vol. 18,1896, p. 215, fjr analyses of gas, largely methane, from 

southern Ohio. Hofer (Das Erdol, pp. 100-103) gives many other data. In Boverton Ecdwood's Petroleum and its products, 2d ed., vol. 1,1906, pp. 246-250, full tables of analyses are given, with excellent references to literature. An unusual analysis is cited by G. B. Richardson in Bull. U. S. Geol. Survey No. 

2GO, 1905, p. 481. Many other analyses are published in Trans. Am. Inst. Min. Eng., vol. 15, pp. 529 ct seq. 

For analyses of California!! gas see G. A. Burrell, Bull. U. S. Bur. Mines No. 19,1911, p. 47. On liquefaction of natural gas. see L. C. Alien and G. A. Burrell, Tech. Paper U. S. Bur. Mines No. 10,1912. Other 

analyses by Burrell and G. G. Oberfell are in U. S. Bur. Mines, Tech. Paper No. 109,1915. 

 6 Largely CH.|, with more or less ethane. CO not found by Phillips.

The analyses of Pennsylvania gases by S. P. Sadtler* gave somewhat different results. In gas from four different wells he found, 

in percentages, CH4, 60.27 to 89.65; CJE^, 4.39 to 18.39; and H2 , 4.79 

to 22.50. These high figures for hydrogen are unusual and suggest 

a resemblance to coal gas. In all cases, however, methane is the preponderating constituent, the characteristic hydrocarbon of natural 

gas. In the natural gas of Point Abino, Canada, F. C. Phillips 2 

found 96.57 per cent of paraffins and 0.74 of H2S.

Hydrocarbons of the form CnH2n are, as constituents of petroleum, 

of equal importance to the paraffins. These again fall into several 

independent series, which vary hi physical properties and in their 

chemical relations, but are identical in percentage composition. One 

series, the olefines, is parallel to the paraffin series, and the following 

members of it are said to have been isolated from petroleum. 3

1 Second Gcol. Survey Pennsylvania, Kept. I, 1876, pp. 146-160. Sadtler cites some analyses by other 

chemists.

2 Jour. Arn. Chem. Soc., vol. 20,1S98, p. 696. 

s Soo H. Hofcr, Das Erdol, p. 65.
724 DATA OF GEOCHEMISTRY. 

So-called "olefines" isolated from petroleum.

Name.

1. Gaseous:

Propylene. ...........................

Butylene. . ...........................

2. Liquid:

TT p v v 1 P Ti p

T^PPvlpTlP

Duodecylene. . .......................

HPri HP/** vl pn p

Cetene ..............................

3. Solid:

Formula.

C

TT 

2^4- ......

C3H6 .......

C

TT 4H8 .......

r L5TT±l,0 . . .

/-I TT L6H12 . . .

C7H14 . . .

08M10 . . .

UM, 8 . . .

r L UTTM22 .....

C12H24 .....

r TT

r> TT

r< 0 TT 27HS4 . ....

Melting point.

°c.

65-66

fi?

Boiling point.

°c.

-103

- 18

- 5

+ 35

68

. . 98

124

153

172

195

216

232. 7

275

This table is probably exact in an empirical sense, but not so constitutionally. Hydrocarbons of the indicated composition have undoubtedly been found, and some of them are certainly olefines. 

According to C. F. Mabery,1 however, the true olefines, the "openchain '' series, are present in petroleum at most in very small amounts. 

In Canadian petroleum Mabery and W. 0. Quayle 2 identified hexylene/ heptylene, octylene, and nonylene. In other cases, and notably 

in the Russian petroleums, the compounds CnH2a are not olefines, but 

cyclic hydrocarbons of the polymethylene series, which were originally called naphthenes. They were at first supposed to be derivatives 

of the benzene series, and it is only within recent years that their true 

constitution has been determined. In Russian oils they are the principal constituents, and according to C. F. Mabery and E. J. Hudson 3 

they also predominate in California petroleum.

Members of the series from C7H14 to C15H30 were isolated from the 

California material. Mabery and S. Takano 4 also found that Japanese petroleum consisted largely of CnH2n hydrocarbons. Other similar occurrences are recorded in the treatises of Hofer and Redwood.5

The series CnH2n_2 is often called the acetylene series, after its 

first member, acetylene, C2H2 . The lower members of this series

1 Jour. Am. Chcm. Soc., vol. 28,1906, p. 415. An important summary of our knowledge relative to the 

composition of American petroleums.

2 Proc. Am. Acad. Arts and Sci., vol. 41,1905, p. 89.

3 Idem, vol. 36,1901, p. 255.

< Idem, p. 295.

B. In vol. 2 of Redwood's great work, there is a bibliography of petroleum covering nearly 6,000 titles. 

In the text Redwood gives a full discussion of the composition of various petroleums, and so too does Hofer. 

Only the barest outline of the subject can be given here, and that must presuppose a knowledge on the 

part of the reader of elementary organic chemistry.
THE NATURAL HYDROCARBONS. 725

seem not to have been found in petroleum; but several of its higher 

members are characteristic of oils from Texas, Louisiana, and Ohio. 

In oil from the Trenton limestone of Ohio, Mabery and 0. H. Palm * 

found hydrocarbons having the composition C10H36 , C21H40 , C22H42 , 

and C24H46 . With these compounds were members of the CnH2n 

series as high as C17H34 . There were also members of the next series, 

CnH2n_4 namely, C23H42 , C24H44 , and C25H46 . In petroleum from 

Louisiana, C. E. Coates and A. Best 2 found the hydrocarbons C12H22 

and C14H26 . These, together with C16H30 , were also separated by 

Mabery 3 from Texas oils. These oils are furthermore peculiar in 

containing free sulphur, which separates out in crystalline form.4 In 

petroleum from Santa Barbara, California, Mabery 5 discovered 

hydrocarbons of the three series CnH2n_2, CnH2n_4 , and CnH2n_8 , represented by the formulae C13H24 , C16H30 , C17H30 , C18H32 , C24H44 , C27H46 , 

and C29H50 . A remarkable oil from the Mahonmg Valley, Ohio, 

according to Mabery,0 consists almost entirely of hydrocarbons of 

the series CnH2n_2 and CnH2n_4 . Paraffins are entirely absent.

Hydrocarbons of the'series CnH2n_6 , the " aromatic" or benzene 

series, occur in nearly all petroleums, but in usually subordinate 

amounts. Their empirical formulae, ignoring the existence of isomeric compounds, are as follows:

Benzene....................................................... C0H6

Toluene.......................................................C7H8

Xylene.......................................................C8H10

Cumene.......................................................C9H12

Cymene....................................................... C, 0H14

Etc.

According to Mabery,7 Pennsylvania petroleum contains small proportions of the lower members of this series, and Mabery and Hudson 8 

found larger amounts of them, especially of the xylenes, in California 

oil. Numerous other examples are cited by Hofer and Redwood, but 

they need not be multiplied here.0 Naphthalene, Cj0H8 , is the only 

compound of the series CnH2n-12 which has been certainly identified

1 Am. Clicm. Jour., vol. 33,1905, p. 251.

2 Jour. Am. Chem. Soc., vol. 25,1903, p. 1153.

3 Idem, vol. 23,1901, p. 264. See also on Texas oils, C. Richardson and E. C. Wallace, Jour. Soc. Chem. 

Ind., vol. 20,1901, p. 690; F. C. Thiele, Am. Chem. Jour., vol. 22,1899, p. 489; W. B. Phillips, Bull. Univ. 

Texas No. 5, 1902; C. W. Hayes and W. Kennedy, Bull. U. S. Geol. Survey No. 212, 1903; R. T. Hill, 

Trans. Am. Inst. Min. Eng., vol. 33,1903, p. 3G3; and N. M. Fenncman, Bull. U. S. Geol. Survey No. 282, 

190C. Fcnneman describes both Texas and Louisiana petroleums. On the composition of Kansas oils, 

sec F. W. Bushong, Kansas Univ. Geol. Survey, vol. 9, 1908, p. 303. In the same volume, p. 187, 

E. Haworth discusses the origin of oil and gas.

«ScoC. Richardson and E. C. Wallace, Jour. Soc. Chem. Ind., vol. 21,1902, p. 310; and Thiele, Chem. 

Zcitung, vol. 20,1902, p. 896.

5 Am. Chem. Jour., vol. 33,1905, p. 270.

6 Jour. Ind. Eng. Chem., vol. 6,1914, p. 101. 

i Jour. Am. Chem. Soc., vol. 28,1906, p. 418. 

8 Proc. Am. Acad. Arts and Sci., vol. 36,1890, p. 255.

8 R. Zalozicclci and J. Hausmann (Zcitschr. angew. Chemie, 1907, p. 1761) have called attention to the 

richness of Rumanian petroleum in aromatic hydrocarbons.
726 DATA OF GIMCfl'.'KMISTRY.

in petroleum. It was found by C. M. Warren and F. H. Storer 1 in 

Rangoon oil, and also by Mabery and Hudson in oil from California. 

In one of Mabery and Hudson's distillations of crude oil so much 

naphthalene was present that the distillate became solid on slight 

cooling. Still more complex hydrocarbons have been found in petroleum residues, but it is possible that they were formed during the 

process of refining. It is not certain that they were present in the 

natural oil.2

In many petroleums small quantities of oxidized bodies arc contained, sometimes complex acids, sometimes phenols. According to 

Mabery,3 the phenols are found in notable proportions in some Callfornia oils but not in petroleum from the eastern part of the United 

States.

L

Nearly all petroleums contain nitrogen, from a trace up to 1 per 

cent and over. It appears to exist in most cases, if not in all, in the 

form of complex organic bases, but their constitution is yet to be 

determined. They are peculiarly abundant in California oil, in which 

they were discovered by S. F. Peckham,4 and Mabery 5 has shown 

that in some cases they constitute from 10 to 20 per cent of the crude 

petroleum. Mabery isolated compounds of this class ranging from " 

C12H17N to C17H21N, although these formulae are subject to some 

uncertainty.

Petroleum free from sulphur is extremely rare, but the amount 

of this constituent is commonly very small. In some instances, however, the sulphur compounds are annoyingly abundant, as, for example, in the Lima oil of Ohio. In this oil Mabery and A. .W. Smith 6 

found normal sulphides of the paraffin series and isolated ten com- . 

pounds ranging from methyl sulphide, C2H«S, to hexyl sulphide, 

C^H^S. In Canadian petroleum Mabery and Quayle 7 discovered 

another series of sulphur compounds, of the general formula CnH2nS, -r 

which they named thiophanes. Eight members of this series were 

described, between C7H14S and C18H36S. Other sulphur compounds 

have been mentioned as occasional admixtures in petroleum, and the 

occurrence of free sulphur in Texas oil has already been noted.8

i Mein. Am. Acad. Arts and Sci., 2d ser., vol. 9,1805, p. 208. 

. * For data and references, see Hofcr, Das Erdol, p. 74. 

»Jour. Am. Chcm. Soc., vol. 28,1900, p. 590.

* Am. Jour. Sci., 3d ser., vol. 48,1894, p. 250. 

«Jour. Soc. Chcm. Ind., vol. 19,1900, p. 505. F. X. Bandrowsky (Monatsh. Chcmie, vol. 8,18S7, p. 224) 

and A. Wellcr (Ber. Deutsch. chcm. Gesell., vol. 20,18S7, p. 2097) have detected nitrogenous bases in European oils. *" 

e Am. Chem. Jour., vol. 13,1891, p. 233.

* Proc. Am. Acad. Arts and Sci., vol. 41,1905, p. 89. A paper by R. Kayscr, published in 1897, con- ' 

tains data relative to sulphur compounds in Syrian asphalt oils. I have not been able to consult his 

original memoir. Cited by W, C. Day in Jour. Franklin Inst., vol. 140,1895, p. 221, and also in Kohler's , 

treatise on asphalt.

8 Onsulphur in California petroleum;,sec S. F. Pcckhara, Proc..Am,.rhilos..Soc.,-vol. 30, 1897, p. 103. 

Also S. F. and H. E. Peckham, Jour. Soc. Chcm. Ind., vol. 1C, 1897, p. 996, on tho sulphur content of 

bitumens. On the specific gravity, of sulphiiroils sco G. S. Rogers, Trans. Am. Inst. Min..Eng. vol. 52, 

1917, p. 989. -
THE NATURAL HYDROCARBONS. 727

In many, perhaps in all gas and oil fields the gas or oil is accompanied by deep-seated waters, which often approach ocean water in 

composition, although modified by local conditions and differing in 

concentration. Such waters are variously interpreted sometimes as 

fossil sea water, which was entrapped in the priginal sediments, a<nd 

sometimes as derived by leaching from beds of salt. These waters 

have not received as yet the exhaustive study which they deserve, 

although there is a moderate amount of literature with reference to 

them. G. S. Rogers, 1 for example, has studied the oil-field waters 

of San Joaquin Valley, California, and has found that as the oil zone 

is approached the sulphates diminish in amount and sulphides appear 

showing that reduction has occurred. In the surface waters sulphates, 

calcium and magnesium predominate; chlorides and sodium are more 

conspicuous in the deeper flow. The investigation is being continued 

and may help to shed more light upon the vexed problem of the 

origin of petroleum.

Between liquid petroleum and solid asphalt there are numberless 

intermediate substances. Indeed, there is no distinct break in the 

continuity of the series from natural gas to bituminous coal.2 The 

latter contains solid hydrocarbons of undetermined character, which 

break up under the influence of heat, yielding coal gas and various 

tarry products. Some of the heavier hydrocarbon mixtures are viscous, pasty semifluids; others are black, brittle solids, which resemble coal in their outward appearance. Albertite, grahamite, uintaite, 

and the so-called "pitch coal" of Oregon are familiar examples of 

these solid forms.

Many of the solid hydrocarbons have been described as mineral 

species and given specific names.3 Scheererite, fichtelite, konlite, 

hatchettite, ozokerite, zietrisikite, elaterite, hartite, napalite, tabbyite, etc., are among the substances. They vary widely in composition, being commonly, if not in all cases, mixtures, and they represent different series of hydrocarbons. They also occur under widely 

differing conditions, indicating genetic distinctions. Some are found 

in coal in such a way as to show their derivation from vegetable 

resins; others appear to be inspissated petroleums; others again are 

associated with metallic ores, and are seemingly of solfataric origin. 

Napalite, for example, is found with ores of mercury in California, 

and the oxygenated compound idrialite occurs under similar conditions in the quicksilver mine of Idria.'^ Most of these substances are 

found in small quantities, and are so imperfectly described that they

. i Bull. U. S. Cool, Survey No. 053,1917. See also R. O. Ncal, Bull. Arn. Inst. Min. Eng., Jan., 1919, p. 1.

2 This continuity, and the probable community of origin is emphasized by Mabery, Jour. Ind. Eng. 

Chem., vol. 6,1914, p. 101. See also David White, Jour. Washington Acad. Sci., vol. 5,1915, p. 189.

3 See Dana, System of mineralogy, 6th ed., pp. 996-1024.

< Bitumen is also common in the New Almaden mines. Its association with the lead and zinc ores of 

Missouri and with the copper-bearing shales of Mansfeld, Germany, is an occurrence of a different order, 

with which solfataric action has nothing to do.
728 DATA OF GEOCHEMISTRY.

need no detailed consideration here. Others, like ozokerite, albeit 

tite, grahamite, uintaite, and the various asphaltums and bitumens, 

occur in large deposits and are of commercial significance.

Ozokerite, for instance, is an important source of paraffin. In 

fact, it appears to consist largely of the higher hydrocarbons of the 

paraffin series, although some varieties probably contain compounds 

of the form CnH2n . In Caucasian ozokerite F. Beilstein and E. 

Wiegand 1 found a hydrocarbon to which they gave the name lekene, 

and which appears to be a polymer of CH2 . In the ^ozokerite of 

Utah 2 paraffin predominates, of composition between C^H^ and

^25^52-

Uintaite, or gilsonite,3 is another black, brittle, lustrous mixture 

of hydrocarbons found in the Uinta Mountains, Utah. Another 

similar mineral from Utah was named wurtzilite by W. P. Blake. 4 

The exact nature of these hydrocarbons is yet to be determined. The 

same remark may be applied to the albertite 5 of New Brunswick, 

the grahamite 6 of West Virginia, the -pitch coal" 7 of Coos Bay, 

Oregon, and other like substances. The albertite and grahamite 

fill veinlike fissures in the country rock, into which they were possibly injected when fluid. These hydrocarbons, it should be observed, 

are fusible, therein differing from coal. They are also variably 

soluble in organic solvents. Their origin is obscure. Some authors 

attribute them to the oxidation of lighter oils; others, like S. F. 

Peckham 8 regard them as residues from a natural distillation of 

petroleum. The oxidation theory is borne out by the fact that 

grahamite, according to White, contains 13.5 to 14.7 per cent of 

oxygen, while W. C. Day found 14.61 per cent in the Oregon mineral. 

Furthermore, W. P. Jenney, 9 by aspirating heated air through Pennsylvania petroleum for several hours, partially converted the oil 

into a substance resembling grahamite. In this experiment, obvi1 Ber. Deutsch. chem. Gesell., vol. "1C, 1883, p. 1547.

2 On Utah ozokerite, see J. S. Newberry, Am. Jour. Sci., 3d ser., vol. 17,1879, p. 340; and A. N. Seal, JourFranklin Inst., vol. 130,1890, p. 402. A monographic paper on ozokerite by E. B. Gosling (School of Mines 

Quart., vol. 16, 1894, p. 41) contains a bibliography of the mineral. Dcr Erdwachsbergbau in Boryslaw, 

by J. Muck, Berlin, 1903, is an important monograph on ozokerite.

3 Uintaite has priority, but gilsonite is the name most commonly used. On this bitumen see J. MLocke, Trans. Ann. Inst. Min. Eng., vol. 17,1887, p. 162; R. W. Raymond,idem, vol. 18,1888, p. 113; W. P. 

Blake, idem, vol. 18,1890, p. 563; G. H. Stone, on Utah and Colorado asphalts, Am. Jour. Sci., 3d ser., 

vol. 42,1891, p. 148; and G. H. Eldridge, Seventeenth Ann. Sept. U. S. Geol. Survey, pt. 1,1896, p. 915, 

and also Bull. No. 213, 1903, p. 296. A chemical investigation of gilsonite by W. C. Day is reported in 

Jour. Franklin Inst., vol. 140,1895, p. 221.

«Trans. Am. Inst. Min. Eng., vol. 18, 1890, p. 497; Eng. and Min. Jour., vol. 48, 1889, p. 542; vol. 49, 

1890, p. 106.

B C. H. Hitchcock, Am. Jour. Sci., 2d ser., vol. 39,1865, p. 267; and S. F. Peckham, idem, vol. 48,1869, 

p. 362.

6 J. P. Lesley, Proc. Am. Philos. Soc., vol. 9,1§63, p. 183; and.I. C. White, Bull. Geol. Soc. America, vol. 

10,1898, p. 277. J. P. Kimball (Am. Jour. Sci., 3d ser., vol. 12,1876, p. 277) has described a "grahamite" 

from Mexico. See also B. Doss, Centralbl. Min., Geol. u. Pal., 1914, p. 609.

' W. C. Day, Nineteenth Ann. Kept. U. S. Geol. Survey, pt. 3,1898, p. 370.

8 Peckham, loc. cit., and also Am. Jour. Sci., 3d ser., vol. 48,1894, p. 389.

» Am. Chemist, vol. 5,1875, p. 359. For analyses of Texas grahamite see E. T. Dumble, Trans. Am. Inst. 

Min. Eng., vol. 21,1893, p. 601.
THE NATURAL HYDROCARBONS. 729

ously, the more volatile hydrocarbons were distilled away. The two 

processes, oxidation and distillation, went on simultaneously.

In most cases the solid hydrocarbons found in nature are not given 

specific names, but are known generically as asphalt or bitumen. 

The pasty, viscid varieties are called maltha. There are also mixtures of these substances with the material of sandstones, shales, and 

limestones, forming the so-called asphalt rocks, from which oils or 

tars can be separated by distillation or melting.

Asphalt- and asphalt rock are widely diffused in nature, being 

found in all parts of the world. Probably the most remarkable 

occurrence of asphalt is that of the famous "Pitch Lake" in Trinidad, which has been many times described best, so far as chemical 

questions are concerned, in three papers by Clifford Richardson. 1 According to Richardson, the "lake" occupies the crater of an old mud 

volcano or geyser, which has become filled with "pitch." This is an 

emulsion of water, gas, bitumen, with some other organic substances, 

and mineral matter. The gas, which is continually evolved, consists 

principally of hydrogen sulphide and carbon dioxide. The water 

which permeates the pitch is rich in saline matter, mainly sodium 

chloride, but it also contains small quantities of berates and of 

ammoniacal salts, which indicate that it is probably of volcanic origin. An analysis of the purified bitumen gave the following results:

Analysis of Trinidad bitumen.

c................................

H..... ...........................

S....... ..........................

N...............................

............................. 82. 33

............................. 10. 69

.:........................... 6.16

............................. .81

99. 99

The sulphur content of this material led to an investigation of 

other asphalts. In eighteen hard asphalts the sulphur ran from 3.28 

to 9.76 per cent, while in soft asphalts or malthas only 0.60 to 2.29 

per cent was found. This leads to the suggestion that sulphur has 

been active in hardening the bitumen; that is, in effecting the condensation and polymerization of the hydrocarbons.2 Oxygen may 

act in the same way, but is eliminated, after union with hydrogen, as

1 Jour. Soc. Chcm. Ind., vol. 17,1898, p. 13; Rept. Inspector Asphalts and Cements, Washington, D. C., 

year ending June 30,189% Proc. Am. Soc. Testing Materials, vol. 6,1906, p. 509. See also N. S. Manross, 

Am. Jour. Sci., 2d ser., vol. 20,1855, p. 153. W. Merivale (Trans. North of England Inst. Mcch. and Min. 

Eng., vol.47,1898, p. 119, has described the "manjak" of Barbadoes, an asphalt resembling that of Trinidad. 

See also R. W. Ells, Ottawa Naturalist, vol. 23, 1907, p. 73. A recent paper by Richardson is in Jour. 

Phys. Chem., vol. 19,1915, p. 241.

2 A well-known method for preparing H2S is to fuse paraffin with sulphur. The reaction doubtless 

involves a union of tho residues from which-hydrogen has been partially withdrawn that is, tho formation of a more condensed hydrocarbon molecule. The reaction does not seem to have been exhaustively 

studied. Some artificial "asphalts" have been prepared by heating petroleum residues with sulphur, 

and a similar substance, "byerlite," is made by tho slow distillation of such residues in presence of air. 

The latter product resembles gilsonite. See C. F. Mabery and J. H. Byerly, Am. Chem. Jour., vol. 18, 

1896, p. 141. See also references to the sulphur processes in Kobler's monograph, p. 119.
730 DATA OF GEOCHEMISTRY.

water. Richardson concludes that the bitumen consists in great 

part of unsaturated hydrocarbons, but their exact nature remains 

undetermined. 1 He also describes the Bermudez, Venezuela, locality. 

In a recent article Richardson 2 has also studied at length the 

nature of grahamite, and given many analyses of samples from 

different localities. It is mainly derived from the condensation of 

paraffin oils, and so differs from gilsonite and manjak, which were 

formed by unsaturated hydrocarbons. Grahamite differs from 

albertite in being soluble in carbon bisulphide; a distinction which 

leads to the designation of albertite as a pyrobitumen, or .more completely metamorphosed petroleum. Richardson also gives examples 

of the presence of vanadium in the ash of grahamite, a fact already 

noticed in the preceding chapter.

SYNTHESES OF PETROLEUM.

Hydrocarbons, notably methane, ethane, acetylene, and benzene, 

have been repeatedly prepared by laboratory methods from inorganic 

sources, and also by the breaking down of more complex organic 

matter. Some of the methods employed have led to the production 

of substances resembling petroleum, and these alone demand consideration here. Let us begin with the inorganic material.

When cast iron is dissolved in an acid, hydrogen is evolved, but 

with contaminations that were long ago recognized as akin to hydrocarbons. In 1864 H. Hahn 3 attempted to determine their exact 

nature by passing the gas through bromine. Organic" bromides were 

thus formed, corresponding to the defines from C2H4 to C7H14 , the 

general formula being CnH2nB.r2 . In hydrogen evolved from spiegeleisen Hahn found still higher hydrocarbons/ up to C1(JH32 . These 

were collected by direct condensation in wash bottles without the 

use of bromine.

In 1873 similar experiments were reported by F. H. Williams,4 

who dissolved spiegeleisen in hydrochloric acid. The gas evolved 

was passed through tubes immersed in a freezing mixture, and 

afterward through bromine. In one experiment 7,430 grams of

i On the composition of asphalt, see also H. Endcmann, Jour. Soc. Chem. Ind., vol. 1C, 1897, p. 121. For 

analyses of Texas asphalts see H. W. Harper, Bull. Texas Univ. Min. Survey No. 3,1902, p. 108. Elaborate 

data are also given by G. H. Eldridge, Twenty-second Ann. Kept. U: S. Geol. Survey, pt. 1,1901, p. 209, 

in a long paper on the asphalts and bituminous rocks of the United States. Important monographs on 

asphalt are by H. Kohler, Die Chemie und Technologic der naturlichen und kiinstlichen Asphalte, Braunschweig, 1904; and P. Narcy, Les bitumes, Paris, 1898. See also T. Posewitz, Mitt.K. ungar. geol. Anstalt, 

vol. 15, Heft 4,1907, pp. 235-463, on petroleum and asphalt in Hungary. Memoirs on the proximate composition of petroleum arc innumerable. I have cited, principally, those of Mabery, because they relate 

specifically to American oils. The limited scope of this volume prevents me from going into details, and 

a vast literature must be passed over. The fundamental labors of Pelouze and Cahours in France, of Schorlemmcr in England, of Markownikoff in Russia, and of others in nearly every country of Europe, can not 

be given the consideration here which is properly due them. 

 JJour. Am.Chem. Soc., vol.32,1910, p. 1032.

«Liebig's Annalen, vol. 129,1864, p. 57. Hahn gives references to the earlier investigations.

4 Am. Jour. Sci., 3d ser., vol. 6,1873, p. 363.
THE NATURAL HYDROCARBONS. 731

iron gave 49 grams of directly condensible hydrocarbons, with 325.5 

grams of bromides; and other experiments yielded similar results. 

The nature of the hydrocarbons was not further investigated.

Much more elaborate researches were those conducted by 

S. Cloez,1 in the years 1874 to 1878. Hydrochloric or sulphuric acid 

was allowed to act on large quantities of spiegeleisen, and the hydrogen, partly by direct condensation and partly by absorption in bromine, yielded abundant hydrocarbons and their bromides, which were 

separated by fractional distillation and identified. Ferromanganese 

gave a particularly large product of hydrocarbons, and a cast manganese, containing 85.4 per cent of metal, was even attacked by water 

alone, with evolution of similarly carburized hydrogen. In his first 

paper Cloez reports that he obtained octylene, C8H16, by direct condensation, with bromheptylene, C7H13Br, and bromoctylene, C8H15Br, 

from the bromine solution. In his second paper he described the 

products obtained during the solution of 600 kilograms of white cast 

iron, which yielded 640 grams of oily hydrocarbons, 2,780 grams of 

bromolefines, and 532 grams of paraffins. Seven of the latter were 

identified, from C10H22 up to C16H34 , hydrocarbons identical with 

those which occur in petroleum; that is, from the carbides contained in cast iron, a mixture of hydrocarbons chemically resembling 

petroleum can be prepared.

 In recent years, through the development of the electric furnace 

by Moissan, many carbides have been made and investigated. The 

greater number of these compounds react with water, yielding hydrocarbons, and the production of acetylene, as an illuminating gas, from 

calcium carbide, has become an important industry. The metallic 

carbides, however, differ in their yield of hydrocarbons, and the 

results obtained may be summarized as follows: 2

The carbides of lithium, sodium, potassium, calcium, strontium, 

and barium, treated with water, yield acetylene, C2H2 .

The carbides of aluminum and glucinum yield principally methane, 

CH4 .

The carbide of manganese yields a mixture of methane and 

hydrogen.

The carbides of yttrium, lanthanum, cerium, thorium, and uranium yield mixtures of acetylene, methane, ethylene, and hydrogen. 

The cerium, lanthanum, and uranium compounds also yield some 

liquid *and solid hydrocarbons. From 4 kilograms of uranium carbide Moissan obtained 100 grams of liquid hydrocarbons, consisting

1 Compt. Rend., vol. 78,1874, p. 1565; vol. 85,1877, p. 1003; vol. 86,1878, p. 1248.

2 See H. Moissan, Compt. Rend., vol. 122,1896, p. 1462. Also a summary by J. A. Hathows, Jour. Am. 

.Chem. Soc,, vol. 21,1899, p. 647. Berthelot (Compt. Rend., vol. 132,1901, p. 281) has discussed the rcac- 

.tions thermochemically. See also M. A. Damiens (Annales do cliimie, 9th ser., vol. 10,1918, p. 137) on tho 

carbides of the cerium group.
732 DATA OF GEOCHEMISTRY.

largely of defines, with, some members of the acetylene series and 

some saturated compounds.

According to R. Salvadori,1 hydrocarbons can be generated by 

heating together calcium carbide and ammonium chloride, an 

observation which has been confirmed by A. Brun.2 Furthermore, 

G. Steiger, in the laboratory of the United States Geological Survey, 

obtained both saturated and unsaturated hydrocarbons by the similar action of ammonium chloride upon the native iron of Ovifak. 

Ammonium chloride, it must be remembered, is one of the most characteristic of volcanic emanations. The bearing of these observations 

upon theories of petroleum formation will be discussed later.

It will be observed that acetylene is a common product of these 

reactions. But acetylene is not a constituent of petroleum. P. 

Sabatier and J. B. Senderens,3 however, have found that when a 

mixture of hydrogen and acetylene is brought into contact with 

finely divided metallic nickel at a temperature of 200° a mixture of 

paraffins is formed which resembles Pennsylvania petroleum. 

Acetylene alone, in presence of nickel, also yields aromatic hydrocarbons, and a mixture is produced resembling Russian oil. In 

this connection it should be noted that M. Berthelot 4 long ago 

proved that acetylene, when heated to the temperature at which 

glass begins to soften, polymerizes into benzene. Three molecules 

of C2H2 yield one of C6H6 . Benzene itself, when heated under 

suitable conditions, loses hydrogen, and the residues combine to 

form diphenyl, C12H10 .

From acetylene, then, as a starting point, higher hydrocarbons 

may be generated. These, again, at high temperatures, act upon 

one another, and the complexity of the final product may be very 

great. Furthermore, carbon and hydrogen can unite directly. 

When the electric arc is formed between carbon terminals in an 

atmosphere of hydrogen, acetylene is produced a reaction discovered by Berthelot.5 According to W. A. Bone and D. S. Jerdan,6 

methane and ethane are formed at the same time, but at a lower 

temperature (about 1,200°) methane is the sole product of the union.

1 Gazz. chim. ital., vol. 32, 1902, p. 496.

2 Arch. sci. phys. nat., 4th ser., vol. 27, 1909, p. 113.

« Compt. Rend., vol. 134, 1903, p. 1185. Similar results to those of Sabatier and Senderens hav« also been 

obtained by K. Charitschkoff, Chem. Zentralbl., 1907, p. 294. A paper by Charitschkofl on the origin of 

petroleum is abstracted in Jour. Chem. Soc., vol. 102, pt. l, 1912, p. 329.

4 Annales chim. phys., 4th ser., vol. 12, 1867, p. 52. According to E. Briner and A. Wroczynski (Arch. 

Sci. Phys. Nat., 4th ser., vol. 32, 1911, p. 389), the polymerization of acetylene is much aided by pressure.

» Annales chim. phys., 3d set., vol. 67, 1863, p. 64.

6 Jour. Chem. Soc., vol. 71, 1897, p. 41; vol. 79, 1901, p. 1042. See also J. N. Pring and R. S. Button, 

idem, vol. 89, 1906, p. 1591. Also W. A. Bone and H. F. Coward, Jour. Chem. Soc., vol. 93, 1908, p. 1975; 

vol. 97, 1910, p. 1219.
THE NATURAL HYDROCARBONS. 733

Even by passing hydrogen over charcoal at 1,200° methane may be 

formed.

So much for the inorganic syntheses of hydrocarbons. On the 

other side of the question it has long been known that the destructive 

distillation of organic matter, animal or vegetable, under conditions 

which preclude the free access of air, will produce hydrocarbons and 

nitrogenous bases. This fact was first applied to the production of 

an artificial petroleum by C. M. Warren and F. H. Storer 1 as far 

back as 1865. They prepared a lime soap from menhaden (fish) oil, 

which, on destructive distillation, yielded a mixture of hydrocarbons 

hardly distinguishable from coal oil 2 or kerosene. From this 

mixture they isolated and identified the paraffins pentane, hexane, 

heptane, and octane; the defines amylene, hexylene, heptylene, 

octylene, nonylene, decylene, undecylene, and duodecylene, together 

with benzene, toluene, xylene, and isocumene, members of the 

aromatic series. A true artificial petroleum had been prepared.

In 1888 C. Engler's famous investigations 3 were announced. He 

distilled menhaden oil, unsaponified, at a temperature between 320° 

and 400°, and under a pressure of ten atmospheres. The distillate 

resembled petroleum and contained the paraffins from C5H12 up to 

C7H10 . In a later memoir 4 he mentions the isolation of normal 

octane and nonane, with secondary hexane, heptane, and octane. 

In a still later research with T. Lehmann 5 he also obtained olefines 

from C0H12 up to C9H18 and some derivatives of the benzene series. 

These experiments upon fish oil confirmed those of Warren and 

Storer, but differed from theirs in the direct use of the oil instead 

of its fatty acids alone. The lime soap of the American chemists 

contained only the acids of the oil, separated from its glycerine. The 

entire oil was used by Engler. From this crude product Engler also 

prepared an illuminating oil, practically indistinguishable from 

commercial kerosene.6

Analogous experiments, but with a somewhat different purpose, 

were carried out by W. C. Day.7 A mixture of fish (fresh herring) 

and resinous pine wood was distilled from an iron retort, the process 

being continued to complete carbonization of the residual material. 

The distillate consisted of a mixture of oil and water, and the oil, 

upon redistillation, yielded a residue closely resembling gilsonite. 

When fish alone was distilled, the final product was more like

1 Mem. Am. Acad. Arts and Sci., 2d ser., vol. 9,1865, p. 177.

* Coal oil is oil distilled from shale or coal. The term is not synonymous with petroleum, although it ia 

often, loosely, so used;

" Ber. Deutsch. chem. Gesell., vol. 21,1888, p. 1816. 

< Idem, vol. 22,1889, p. 592.

6 Idem, vo!30,1897, p. 2365. A paper by C. Engler and E. Severin on artificial petroleum is in Zeitschr. 

angew. Chemie, vol. 25,1912, p. 153. 

a Observations confirmed by Redwood, Petroleum and its products, 2d ed., vol. 1, p. 259.

7 Am. Chem. Jour., vol. 21,1899, p. 478.
734 DATA OF GEOCHEMISTRY.

elaterite. Wood alone gave a similar oil, wiih a similar residue on 

redistillation. In this research, then, artificial asphalts were 

obtained, curiously resembling the natural substances. They also, 

like ordinary asphalt, contained some nitrogen.

Vegetable oils likewise yield hydrocarbons upon destructive 

distillation. S. P. Sadtler, 1 for example, established this fact with 

regard to linseed oil, but the nature of the product was not completely 

.determined. Engler 2 obtained hydrocarbons by the distillation of 

colza and olive oils, as well as from fish oil, butter, and beeswax. 

Furthermore, J. Marcusson 3 cites an experiment in which pure oleic 

acid was heated for several hours'to 330° in a sealed tube. On 

opening the tube there was a strong evolution of gas, and in the 

residue a product was found which completely resembled a lubricating oil from petroleum. These examples are only two out of many 

which .might be adduced.

ORIGIN OF PETROLEUM.

Probably no subject in geochemistry has been more discussed 

than that of the origin of petroleum. Theory after theory has been 

proposed, and controversy is still active. The evidence is abundant 

but contradictory, and leads to different conclusions when studied 

from different points^ of view.

The theories so far advanced may be divided into two categories 

the inorganic and the organic. Let us examine the hypotheses separately. The earlier speculations connecting the formation of petroleum with volcanic phenomena may be passed over, for the reason that 

they were framed at a time when essential evidence was not available. 

They were speculations, nothing more. The modern era begins with a 

memoir by M. Berthelot, 4 published in 1866.

Berthelot started from a supposition of Daubre"e that the interior 

of the earth might contain free alkaline metals. Upon these, as Berthelot had previously shown, carbon dioxide could react at high temperatures, forming acetylides from which, with water, acetylene 

would be generated, with all of its possibilities of condensation into 

higher hydrocarbons. The weak point of the hypothesis, which Berthelot only advances tentatively, is that no evidence exists to show 

that the alkaline metals are present in an uncombined state at any 

point below the surface of the earth. The starting point is a pure 

assumption, which is more likely to be erroneous than true.

Leaving out of account the oft-cited paper by H. Byasson, 5 which 

has ho present value, we come next to the famous carbide theory of

1 Proc. Am. Philos. Soc., vol. 36,1897, p. 93.

2 Cong. internat. du p^trole, Paris, 1900, p.'20. " .

3 Chem. Zeitung, vol. 30^1906, p. 789.

«Annales chim. phys., 4th ser., vol. 9,1866, p. 481.'

* Compt. Rend., vol. 73 ,1871, p. Gil. A later, separate brochure by Byasson I have not seen.
THE NATURAL HYDROCARBONS. 735

D. MendelSef, 1 published in 1877. This theory presupposes the 

existence of iron carbides within the earth, to which percolating waters 

gain access, generating hydrocarbons. If such carbides exist at reasonable depths below the surface of the earth, the suggested reactions 

would presumably take place; but the major premise is as yet 

unproved. The actual existence of the carbides in nature remains to 

be demonstrated.

MendeleWs hypothesis naturally attracted much attention and 

was rendered plausible by researches like those of Hahn, Williams, 

and Cloez upon the production of hydrocarbons from cast iron. It 

was still further strengthened by the discoveries of Moissan in his 

development of the electric furnace, and has had many advocates. 

Moissan 2 himself has adopted it, and also suggested that volcanic 

explosions may perhaps be caused by the action of water upon subterranean carbides. He admits, however, that some petroleums are possibly of organic origin. The presence of marsh gas in volcanic emanations 3 may be cited in support of Moissan's suppositions, but this 

well-recognized fact can be interpreted otherwise. Another favorable 

datum has been furnished by 0. Silvestri,4 who found in basaltic lavas 

from near Etna both liquid oils and a solid paraffin which melted at 

56°. Similar observations have been made by A. Brun,5 in his study 

of the Javanese volcanoes. He regards the petroleum of Java as of 

volcanic origin. But these oils, as well as the marsh gas, may conceivably have been formed either through a direct union of carbon 

and hydrogen or from material distilled by volcanic heat out of 

adjacent sedimentary rocks. The same considerations also apply 

to the petroleum field near Tarnpico, Mexico, as described by E. 

Ord6nez, Gl which is dited by E. Coste 7 in support of his elaborate 

argument in favor of the inorganic origin of petroleum. In this field 

the oil rises close to volcanic cones; which, however, have been 

forced up through a great thickness of Cretaceous shales. The possibility of a distillation of oil from organic matter in the sediments 

must here be taken into account. This has been done by E. De 

Golyer, 8 who has shown that the oil of the Tampico-Tuxpam region 

probably came by migration from adjacent limestones. In fact some 

of the oil is in no wise related to the igneous intrusions.

1 Bcr. Deutsch. chem. Gescll., vol. 10,1877, p. 229; Jour. Chem. Soc., vol. 32, p. 283. Scoalso Mcndclccf's 

Principles of chemistry, English translation, vol. 1,1891, pp. 3G4-3G6.

2 Compt. Eend., vol. 122,1896, p. 1462. See also S. Meunier, idem, vol. 123,1890, p. 1327.

a See ante, Chapter VIII. 

 * Gazz. chim. ital., vol. 7,1877, p. 1; vol. 12,1882, p. 9.

6 Arch. sci. phys. nat., 4th ser., vol. 27,1909, p. 113.

6 Min. and Sci. Press, vol. 95,1907, p. 249.

' Jour. Canadian Min. Inst., vol. 12,1909, p. 273. For. earlier papers by Coste sec the same journal, vol. C, 

1903, p. 73, and T.rans. Am. Inst. Min. Eng., vol. 35,1905, p. 288. F. Rigaud (Rev. univ. des mines, 4th ser., 

vol. 31, 1910, p. 145) has also argued in favor of the inorganic origin of petroleum. See also I. Guarcschi, 

Petrolii cd emanazioni tcrrestri, Torino, 1917.

8 Econ. Geology, vol. 10,1915, p. G50.
736 DATA OF GEOCHEMISTEY.

Another instance of oil in igneous rocks, in Williamson County, 

Texas, has been reported by J. A. Udden. 1 The rock is a porous eruptive, largely changed to serpentine, which has invaded beds of chalk 

and marl rich in organic remains, especially of foraminifera. These 

were probably the true sources of the petroleum.

A different line of investigation relative to the genesis of petroleum is that proposed tentatively by G. F, Becker. 2 If petroleum is 

derived from iron carbides, as the inorganic theory assumes, there 

should be magnetic irregularities in oil-bearing regions. This he 

finds to be the case in the Appalachian oil field, where the lines of 

magnetic declination are sensibly deflected. Similar irregularities 

appear in the oil fields of California, and magnetic disturbances 

are also recorded in the region of the Caucasus. The observations 

are not absolutely conclusive, but they are compatible with the 

inorganic theory.

Two other speculations upon the genesis of petroleum from inorganic matter remain to be mentioned, if only for the sake of completeness. N. V. Sokoloff, 3 in 1890, argued that the bitumens are of 

cosmic origin, formed initially during the consolidation of the planet, 

inclosed within the primeval magma, and since emitted from the 

earth's interior. In support of this conception he cites the occasional 

finding of hydrocarbons in. meteorites, 4 cases in which the possibility 

of an organic origin seems to be absolutely excluded.

The other speculation is that of O. C. D. Ross, 5 who has tried to 

show that petroleum may originate from the action of solfataric 

gases upon limestones. Ross wrote various chemical equations to 

show how the reactions might occur, but they are improbable and 

experimentally unverified.

It will be seen, upon consideration, that these inorganic theories 

concerning the origin of petroleum relate not only to its proximate 

genesis, but to fundamental questions of cosmology. Sokoloff's 

hypothesis is an indication of this fact, and the assumption of 

carbides within the earth represents an effort in the same direction. 

An illustration of this implication is to be found in Lenicque's 

remarkable memoir, 6 which was cited in Chapter II of this volume.

i Econ. Geology, vol. 10, 1915, p. 683.

* Bull. U. S. Geol. Survey No. 401,1909.

s Bull. Soc. imp. nat. Moscou, new ser., vol. 3,1890, p. 720.

< See F. Wohler, Liebig's Annalen, vol. 109,1859, p. 3-19, on carbon compounds in the meteorite of Kaba, 

Hungary. Also S. Meunier, Compt. Rend., vol. 109, 1889, p. 976, on the meteorite of Mighei, Russia. 

A. E. Nordenskiold (Poggendorf's Annalen, vol. 141,1870, p. 205) found carbonaceous matter in the meteorite of Hessle, Sweden; and G. Tschermak (Sltzungsb. K. Wiss. Akad. Wien, vol. 62, Abth. 2,1870, p. 855) 

reports 0.85 per cent of a hydrocarbon in the stone which fell at Goalpara, India. The well-known meteors 

of Orgueil, France, and Cold Bokkeveld, South Africa, were largely carbonaceous. On Orgueil, see S. Cloe'z, 

Compt. Rend., vol. 59, 1864, p. 37. Graphite and amorphous carbon arc common in meteorites, and in 

some falls diamonds have been found.

»Chem. News, vol. 64,1891, p. 14. A criticism by Redwood appears on p. 215.

« Mem. Soo. ing6n. civils France, October, 1903, p. 346.
THE NATURAL HYDROCARBONS. 737

If the molten globe had at any time a temperature like that of the 

electric furnace, carbides, silicides, nitrides, etc., would be among the 

earliest compounds to form, and oxidation could not begin until later. 

Under such conditions some carbides might remain unoxidized 

through many geologic ages, to be reached by percolating waters at 

the present day. The development of hydrocarbons would then 

inevitably follow, although to what extent they might be subsequently consumed no one can say. The theory is plausible, but is it 

capable of proof? Furthermore, does it account for any accumulations of petroleum such as yield the commercial oils of to-day? 

These essential questions are too often overlooked, and yet they are 

the main points at issue. We may admit that hydrocarbons are 

formed within volcanoes, but the quantities definitely traceable to 

such a source are altogether insignificant. Bitumens occur in small 

amounts in many igneous rocks, but never in large volume. They 

are, moreover, absent, at least in significant proportions, from the 

Archean, and first appear abundantly in Paleozoic time. From the 

Silurian upward they are plentiful, and commonly remote from 

great indications of volcanic activity. Even such an occurrence as 

that of the Pitch Lake in Trinidad, where asphalt is associated with 

thermal waters, does not necessarily imply a community of origin. 

It is at least conceivable that the solfataric springs may. have acted 

upon sedimentary accumulations of oil, partly by vaporizing the 

latter and so bringing it to the surface, and partly by effecting, with 

the aid of steam and sulphur, the condensations or polymerizations 

that are observed. These considerations serve to show the need of 

great caution in dealing with this class of problems and to warn us 

against hasty generalizations. Speculations based upon individual 

occurrences of petroleum are of very little value. The entire field, 

in all of its complexity, must be taken into account.

Admitting that methane is sometimes formed as 'a volcanic 

emanation, we must also recognize the fact that it is more commonly 

of organic origin. Its popular name, " marsh gas," is verbal evidence 

of its derivation from decaying vegetation. Ordinarily, it is generated in apparently small amounts, but gas in Iowa wells has been 

described 1 which occurs in the drift and seems to be of vegetable 

origin. Buried vegetation alone can account for its development 

under the observed conditions.

Apart from the natural occurrences of marsh gas, either in swamps 

or as the "fire damp" of coal mines, its artificial production has been 

studied experimentally. F. Hoppe-Seyler 2 and H. Tappeiner 3 have

1 See A. G. Leonard, Proc. Iowa Acad. Sci., vol. 4, p. 41. F. M. Witter (Am. Geologist, vol. 9,1892, p. 319) 

has described a gas well, about 100 feet deep, near Letts, Iowa.

2 Ber. Deutsch. chem. Gescll., vol. 16, 18S3, p. 122.

3 Idem, pp. 1734, 17-10. See also L. Topoff, abstract in Jour. Cliem. Soc., vol. 2S, 1875, p. 1209, on gas 

from river mud near sewer openings.

113750° 19 Bull.695 47
738 DATA OF GEOCHEMISTRY.

shown that it is formed by the fermentation of cellulose, .together 

with carbon dioxide and free .hydrogen. During the .decay of :seaweeds, however, according .to F. C. Phillips, 1 a .little methane is at 

first :evolved, the generated gases consisting largely of carbon dioxide, 

hydrogen, .and nitrogen. The apparatus in which .the experiment 

was performed was allowed to .stand in position for two and a half 

years, and .during that time, following the first rapid evolution of 

gas, a very .slow, continuous production was observed. At the .end 

of the period the gas consisted of .methane. Phillips -concludes, 

from this evidence, that buried vegetable matter, afiter a brief era of 

rapid gas evolution, may pass into a condition of extremely slow 

decay when methane is generated. It is possible, however, that 

methane is not the only hydrocarbon thus produced.

From data of this kind, and from the experiments cited in the 

preceding section of this chapter, it is evident that hydrocarbons 

analogous to natural gas, petroleum, and asphalt may be derived 

either from animal or vegetable matter, or from both. This, I think, 

admits of no dispute, but argument is possible relative to the genesis 

of the larger accumulations of -mineral oil. Engler'.s researches 

have led to a widespread belief in the animal origin of petroleum, 

although the details of the transformation process .are very diversely 

interpreted.2 Englei13 himself ascribes the derivation of petroleum 

from animal remains to a putrefactive process, which -removes the 

nitrogen compounds. The fats remain, to be altered by heat and 

pressure 4 into hydrocarbons, whose boiling points lie below 300°.; 

and these later .undergo a partial, autopolymerization into denser 

forms. How far such a polymerization may be possible, if indeed 

it is possible at all, is a matter of uncertainty. C. F. Mabery '5 holds 

that the changes are always in the opposite direction and that the 

more complex hydrocarbons are formed first, partially breaking 

down afterward into lower members of the series. J.. Marcussoii" 

holds the same view. The putrefactive removal of the albuminoid

i Am. Chem. Jour., vol. 10,1894, p. 427..

 For a very complete summary .of all.the hypotheses relative .to the formation-ofpetroleum, seeHofer, 

Das Erdol, 1908, pp. 160-229. See also Redwood, Petroleum and its products, vol. 1, 1906, pp. 250-261. 

Othersummaries:are by Aisinmann,, Zeitschr. angew. Ghemie, 1S93> p. 739.; idem, 1894,<p. 122; C. Element, 

Bull. Soc. belgeigdol,, vol. 11, proc. verb.,.lS9/?, p. .76; R. Zuber, Zeitschr. prakt. Geolpgie, 1898, p. 84;.aiid 

E.-Orton,Buli. Geol. Soc. America, vol. 9,1897, p. 85. Recent memoirs on thesubject are by P. de Wilde, 

Arch. sci. .phys. nat., 4th ser., v,ol. .23,1907, p. '559, and C. Neuberg, Sitzungsb. K. A'kad. Wiss. Berlin, 

May 16,1907.

s Ber. Deutsch. chem. Gesell., vol. 30,1897, p. 2358. For more recent articles by Engler see Zeitschr. 

angew.'Chemie, vol. .21,1908, p. 1585; Vorhandl. maturwiss. Vereins, Karlsruhe, 1908, vol. 20, p.'65, and 

Compt. rend. Cong.tinteraat.p<§trole, >Bucarest, 1910, vol. 2, p. 1. The last-named volume contains many 

papers on various subjects relating to petroleum.

< The importance of pressure in petroleum .formation was also urged by :'G. .Kramer and 'W.. Bottoher 

(Ber. Deutsch. chem. Gesell., vol..20,.1887,.p. 505), in .their .comparison .of .the.hydrocarb.ons contained-in 

petroleum and eoal.oil or tar. -H. Monkeand F. Beyschlag (Zeitschr. prakt. :Geologie, 1905, ;pp.,l, 65, .421) 

emphasize the putrefactive process, which .yields petroleum, as compared with the .carbonizing -process, 

which forms coal. . .

s Jour. Am. Ghem. Soc., vol..28,1900., p. 429.

6 Ohcm. Zeitung, vol. 30,-1906, p. 788.
THE NATURAL HYDROCARBONS. 739

substances is also to be questioned, and it is certainly not universal. 

The nitrogen bases of California petroleum furnish perhaps the 

strongest evidence that the proteids contribute their share to the 

make-up of petroleum, and show also that these particular oils are 

of animal origin.

Several other writers have brought evidence to bear in favor of 

the derivation of petroleum from fish remains. Dieulaf ait * observed 

that the copper shales of Mansfeld are strongly impregnated with 

bitumen, and also rich in fossil fish. The petroleum of Galicia is 

always associated with menilitic schists in which fish remains are 

peculiarly abundant. C. Engler 2 cites some computations by Szajnocha, to the effect that the annual catch of herring on the north 

coast of Germany would, if its fats were half converted into petroleum, yield in 2,560 years as much oil as Galicia has produced. G. A. 

Bertels,3 on the other hand, attributes the Caucasian petroleums to 

the decomposition of mollusks. In the Kuban district, the oil, 

accompanied by salt water, exudes directly from beds of molluscan 

remains, which occur in enormous quantities.

Engler, of course, was not the first to advocate a derivation of 

petroleum from animal remains. His views have received special 

attention because of their experimental basis. C. Ochsenius, 4 for 

instance, has sought to connect the formation of petroleum with that 

of the mother-liquor salts which accumulate during the last stage 

of the evaporation of sea water. According to this writer, petroleum 

is generated from marine organisms, preferably the larger forms, 

which are buried beneath air-tight sediments and slowly acted upon 

by the above-named saline residues. As an argument in favor of 

this hypothesis, he calls attention, as many others have done, to the 

common association of brine with petroleum, and cites analyses of 

such waters. This association of salt and oil is strongly emphasized 

by L. Mrazec 5 in his studies of Roumanian petroleum. F. Heusler 6 

also, while indorsing Engler's principal conclusions, invoked the aid 

of aluminum chloride as an agent in effecting a polymerization of 

the hydrocarbons. According to Ochsenius's theory, magnesium

1 Cited by A. Jaccar.d, Arch. sci. phys. nat., 3d ser., vol. 24, 1890, p. 106.

2 Ber. Deutsch. chem. Gcscll., vol. 33,1900, p. 16. See also Cong. internal, du pelrole, 1900, p. 30.

s Cited by Hofer, Das Erdol, 1906, p. 219. F. Hornung (Zeitschr. Deutsch. gcol. G«sell., vol. 57, Monatsb., 1905, p. 534) argues in favor of fishes as the raw material of petroleum. 'See also J. J. Jahn, Jahrb. 

K.-k. geol. Reichsanstalt, vol. 42,1892, p. 361. For arguments against the theory of Engler, see D. Pantanelli, Bull. Soc. geol. ital., vol. 25,1906, p. 795. Pantanelli seems to favor the inorganic origin of petroleum. W.. Ipatief (Jour, prakt. Chem., ser. 2, vol. 84, 1911, p. SOO) favors the organic origin, and so does 

Mabery (Econ. Geology, vol. 11,1916, p. 511), who shows that the nitrogen bases found in oil could not 

form or exist at volcanic temperatures.

« Chem. Zeitung, vol. 15,1891,'p. 935, and Zeitschr. Deutsch. gcol. Gescll., voj. f.S, 1SSO, p. 239. See also 

his papers cited in Chapter VII, ante.

BCompt. rend. Cong. internal, petrolc, Bucarcst, 1910, vol. 2, p. 80. Also L'industric du p6trolo en 

Roumanio, Bnearest, 1910. The presence of methane, ethane, etc., in rock salt -has been studied by N. 

Costachescii, Annales sci. Univ. Jassy, vol. 4, 1900, p. 3. Cu the animal origin of petroleum sec also L. 

Singer, Inaug. Diss., Zurich, 1893.

e Zeitschr. angew. Chemie, 1896, pp. 2S8,318.
740 DATA OF GEOCHEMISTRY. 

chloride was the active substance. These suggestions are of very 

little value, for the reason that the laboratory reactions with 

aluminum chloride are effected with the anhydrous salt and not 

with its hydrolyzed aqueous solutions. It is not shown experimentally that the latter would be effective, nor does aluminum 

chloride occur in any notable quantity hi natural waters.1 A more 

probable function of the salts, according to R. Zaloziecki,2 is to retard 

and modify the decay of animal matter on or near the seashore, and 

so to give time for its transformation into petroleum. The latter 

process need not be very slow, for E. Sickenberger 3 has shown that in 

small bays of the Red Sea, where the salinity reaches 7.3 per cent, 

petroleum is actually forming as a scum upon the surface of the water. 

Living forms are abundant in these bays, and their remains, after 

death, furnish the hydrocarbons. The latter are to some extent 

absorbed into the pores of coral reefs, and so contribute to the formation of bituminous limestones. A still earlier publication by O. F. 

Fraas,4 contains data of similar purport. Fraas found in Egypt 

shells filled with bitumen, and noticed that the bituminous beds .were 

rich in fossils, while the nonbituminous strata were poor. In the 

region of the Dead Sea, also, Fraas noticed that bitumen was abundant 

in beds of baculites, from which it exudes to accumulate upon the 

shore. In this connection it may well be noted that the brines which 

are so often associated with petroleum have, as a rule, a composition 

indicative of a marine origin, and do not resemble solfataric or volcanic waters.5 Furthermore, Mendele*ef s objection to the possibility 

of forming petroleum at the bottom of the sea namely, that being 

lighter than water it would float away and be dissipated is not only 

negatived by Sickenberger's observations, but also by the well-known 

fact that mud and clay are capable of retaining oily matters mechanically. The littoral sediments probably aid in the process of petroleum formation, if only to the extent of retaining the fatty substances 

from whiph the oil is to be produced. The beds of sulphur which occur 

adjacent to some oil wells, notably in Texas, were probably formedby the reducing action of organic matter upon sulphates, such as 

gypsum, 'a mineral which is often associated with marine deposits and 

with petroleum. The association of gas, oil, salt, sulphur, and gypsum, which some writers ha?e taken as evidence of former volcanism, 

is much more simply interpreted, both chemically and geologically,

1 A possible exception to this statement is cited by Ochsenius (Zeitschr. Deutsch. geol. Gesell., vol. 48,

1896. p. 239), who mentions a water containing, in its solid residue, 23.91 per cent of Aids. This water 

accompanied a petroleum.

2 Chem. Zeitung, vol. 15,1891, p. 1203.

3 Idem, p. 1582.

aBull. Soc. sci. nat. Neuchatel, vol. 8,1868, p. 58. Sec also F. C. Thillips, Proc. Am. Philos. Soc., vol. 36,

1897. p. 121, on petroleum inclosed in fossils.

* The waters accompanying the naphtha of the Grosny.district, Russia, as analyzed recently by K. 

Charit°ch!toff (Chcm. Zeitung, 1907, p. 295), appear to be exceptional. Tn these sodium carbonate is more 

abundant than the chloride, and salts of ammonium and the amines are also present.
THE NATURAL, HYDROCARBONS. 741

as due to the decomposition of organic matter in shallow, highly saline 

waters near the margin of the sea.

The derivation of petroleum from vegetable remains has had many 

advocates, although the hypotheses have not all been framed on the 

same lines. L. Lesquereux,1 studying the Devonian oils of the eastern 

United States, argued in favor of their derivation from cellular 

marine plants, especially fucoids, whose remains abound in the petroliferous formations. Ligneous or fibrous plants, on the other hand, 

yield coal. This hypothesis led Vouga 2 to suggest that great masses 

of fucus, like those of the Sargasso Sea, might sink to the bottom of 

the ocean, and there, decomposing under pressure, could yield petroleum. Redwood 3 states that the salt marshes of Sardinia are sometimes covered by sheets of seaweed, which are in process of decomposition into an oily, substance resembling petroleum, and similar occurrences have been noted on the coast of Sweden. These phenomena 

are probably not exceptional, and deserve a more precise examination 

than they have received hitherto. An observation by W. L. Watts 4 

that the saline waters associated with petroleum in the central valley 

of California are unusually rich in iodine appears to have some relation 

to this class of hypotheses. Watts connects this iodine with the 

familiar content of iodine in seaweed, and regards the lattei as a 

probable source of this particular oil.

Data of this class might be multiplied almost in definitely. For 

instance, 0. E. Bertrand and B. Renault 5 have shown that Boghead 

mineral, torbanite, and kerosene shale, from which oils are distilled, 

are derived from gelatinous algee, whose remains are embedded in 

what was once a brown humic jelly. This observation may be correlated with the views advanced by J. S. Newberry ° and S. F. Peckham,7 who regard the liquid petroleums as natural .distillates from 

carbonaceous deposits, which latter were laid down at depths below 

the horizons where the oil is now found. The heat generated during 

metamorphism is supposed to be the dynamic agent in this process, 

although many productive regions show no evidence that any violent 

metamorphoses have ever occurred.8

1 Bull. Soc. scl. nat. Neuchfttel, vol. 7,1866, p. 234.

2 See discussion following Lesquercux's communication.

a Petroleum and its products, 2d ed., vol. 1, pp. 126, 142.

< Bull. California State Min. Bur. No. 19, p. 202. See also Bull. No. 3 for more details. In Bull. No. 16, 

1899, A. S. Cooper discusses at length the genesis of petroleum and asphalt in California. Bulls. Nos. 31 and 

32 also relate to this subject.

8 Compt. Rend., vol. 117,1893, p. 593. Sec also Bertrand, Compt. rend. VIII Cong. ggol. internal., 1900, 

p. 458. According to E. C. Jeffrey (Proc. Am. Acad. Arts and Sci., vol. 46,1910, p. 273), the supposed gelatinous algce are the spores of vascular cryptogams.

6 Geology of Ohio, vol. 1,1873, p. 158. See also an earlier paper by Newberry, Rock oils of Ohio, in Fourteenth Ann. Ropt. Ohio State Board Agr., 1S59, p. 605.

7 Proc. Am. Philos. Soc., vol. 10, 1868, p. 445; vol. 37, 1898, p. 108.

8 H. Stremme (Centralbl. Min., Geol. u. Pal., 1908, p. 271) has shown that the polymerisation of petroleum 

may itself generate heat.
742 DATA OF GEOCHEMISTRY.

In 1843 E. W, Binney and J. H. Talbot 1 reported a peculiar occurrence of petroleum permeating a peat bog, Down Holland Moss, not 

far from Liverpool, England. The origin of this oil was obscure, 

but was attributed by the authors to an alteration of the peat itself, 

a mode of genesis which later writers have doubted. J. S. Newberry,2 however, states that in the Bay of Marquette, where the shore 

consists of peat overlying Archean rocks, bubbles of marsh gas arise, 

together with drops which cover the surface of the water, in spots, 

with an oily film. The following investigations seem to bear upon 

the problems suggested by these observations:

In 1899 A. F. Stahl 3 and, independently, G. Kramer and A. Spilker 4 called attention to a possible derivation of petroleum from 

diatoms, which abound in certain bogs. These organisms, according to Kramer and Spilker, contain drops of oily matter, and from 

diatomaceous peat a waxy substance, resembling Ozokerite, can be 

extracted.5 The theory, based upon these data, is briefly as follows: A lake bed becomes filled in time with diatomaceous accumulations, over which a cover of other growths or deposits is formed. 

By decay of the organic substances, ammonium carbonate is produced, which hydrolyzes the wax, and from the resulting acid carbon 

dioxide, carbon monoxide, and water are gradually eliminated. 

Ozokerite is thus formed, which, at moderate temperatures and under 

pressure, becomes converted into liquid petroleum. With higher 

temperatures and pressures, in presence of sulphur, .heavier oils and 

asphalt may be generated. In support of this hypothesis the 

authors describe a lake bed, near Stettin, which is about 23 feet 

thick and consists chiefly of diatoms. This deposit yields a wax containing over 10 per cent of sulphur, and from it a hydrocarbon, 

resembling the lekene from ozokerite, was isolated.

Kramer and Spilker's views have not met with very general 

acceptance, but they seem to contain elements of value. H. Potonie"'s 

hypotheses,6 for example/seem to be a broadening of Kramer and 

Spilker's. This writer calls attention to the "faulschlamm" or 

"sapropel," a slime, rich in organic matter, which is formed from 

gelatinous algae, and accumulates at the bottom of stagnant waters. 

Such a slime, Potonie" believes, may be the parent substance from 

which bitumen, by a process of decay, was probably derived. In this 

connection, and with reference to the adequacy of the proposed 

source, it is well to remember the enormous accumulation of " oozes," 

namely, the radiolarian .and globigerina oozes, on the bottom of the

1 Published in Trans. Manchester Gcol. Soc., vol. 8, 1808, p. 41. Curiously, a later paper by Binney 

appears earlier, namely, in vol. 3,1800, p. 9.

2 Annals New York Acad. Sci., vol. 2, 1882, p. 277.

3 Chcm. Zeitung, vol. 23, 1899, p. 144. Also note in vol. 30, 1906, p. 38.

* Ber. Deutsch. chcm. Gesell., vol. 32, 1899, p. 2940; vol. 35,1902, p. 1212. . Criticism by Engler in vol. 33, 

1900, p. 7.

5 See also C. E. Guignet, Compt. Rend., vol. 91, 1880, p. 888, on wax from peat, 

o Natur. Wochenschr,, vol. 20,1905, p. 599.
THE NATURAL HYDROCARBONS. 743

sea. The organic matter thus indicated is certainly abundant enough, 

if it can decay under proper conditions, to form more hydrocarbons 

than the known deposits of petroleum now contain.1

These remarks upon the oceanic sediments at once suggest an intermediate group of hypotheses, which assume a mixed origin for petroleum. Animal matter in some cases, vegetable matter in others, or 

both together, are supposed to be the initial source of supply. A. 

Jaccard,2 for example, argues that the liquid oils are derived from 

marine plants, while the viscous or solid bitumens may originate 

from mollusks, radiates, etc. Some oils, again, are supposed to be of 

mixed origin, and it would seem probable that the last class is the 

most common. Ideas of this land have repeatedly been enunciated 

with reference to American petroleums that of Pennsylvania being 

attributed to marine vegetation, that of California to animal remains. 

The American literature of petroleum is rich in suggestions of this 

order.3

It has long been known that some petroleums are optically active; 

that is, they are able to rotate a ray of polarized light, sometimes to 

the right and sometimes to the left. This, according to P. Walden,4 

gives us an important datum toward determining the origin of 

petroleum. Only the oils derived from organic matter, Walden 

asserts, can possess this property, the hydrocarbons prepared from 

inorganic materials, such as metallic carbides, being optically inert. 

The oils distilled from coal, which is evidently of vegetable origin, 

are active; and petroleum, which has the same peculiarity, is presumably formed from similar materials. The activity is attributed by 

some writers to derivatives of cholesterin, of animal origin, or else 

to its vegetable equivalent, phytosterin. 5 Apart from this detail the

i Those oceanic sediments a're especially noticed by Engler in a paper read before the petroleum congress 

in 1900 (Cong. internat. du ptStrole, Paris, 1900, p. 28). In A. Becby Thompson's monograph, The oil fields 

of Russia, London, 190-1, pp. 85-87. a theory is developed to account for the probable formation of bitumens 

on the sea bottom. Thompson regards flsh remains as an important source of supply. G. P. Mikhailovski 

(Bull. Com. gcol. St. Petersburg, vol. 25,1908, p. 319) derives the Caucasian petroleum from marine sediments. C. B. Morroy (Bull. Geol. Survey Ohio, No. 1,1903, p. 313) suggests that bacteria have been the 

thief agents in transforming other organic matter into hydrocarbons.

aEclog. Gool.Helvot., vol. 2,1890, p. 87. Seealso Arch.sci. phys. nat, 3d sen, vol. 23,1890, p. 501; vol. 

24,1890, p. 106. Jaccard studied especially the bitumens of the Jura.

8 In addition to the memoirs already cited, see the reports of the Second Geol. Survey Pennsylvania. 

Also J. A. Bownocker, Geol. Survey Ohio, 4th ser., Bull. No. 1,1903; S. S. Gorby, Sixteenth Ann. Rept. 

Indiana Dept. Geol. and Na{;. Hist., 1888; W. S. Blatchley, idem, Twenty-eighth Ann. Kept., 1904; E. 

Haworth, Kansas Univ. Geol. Survey, vol. 1,1896, p. 232; H. P. H. Brumcll, Cool. Survey Canada, now 

ser., Ann. Rept. 5, Q, 1893; and W J McCeo, Eleventh Ann. Rept. U. S. Gool. Survey, pt. 1,1891, p. 589. 

L. Harperath (Bol. Acad. nac. cien. Cordoba (Argentina), vol. 18., 1905, p. 153) has published along mcmoii1 on petroleum and salt. L. V. Dalton (Econ. Geology, vol. 4,1909, p. 603) advocates the organic origin of 

petroleum.

< Chem. Zeitung, vol. 30,1906, pp. 391,1155,1168. Walden cites many examples of this optical activity. 

See also Engler, idem, p. 711, and F. W. Bushong, Science, vol. 38,1913, p. 39.

»Soe M. Rakusin, Chem. Zeitung, vol. 30, 1906. p. 1041; Ber. Deutsch. chcm. Gesell., vol. 42, 1908, pp. 

1211,1640, 4075; J. Marcusson, Chem. Zoitung, vol. 31,1907, p.' 419; vol. 32,1908, pp. 377, 391; R. Albrccht, 

Inaug. Diss., Karlsruhe.-1907; L. Ubbelohde, Ber. Deutsch. chem. Gesell., vol. 42, 1909, p. 3242; vol. 43, 

1910, p. 608. R. Zaloziecki and H. Klarfeld (Chem. Zei'ung, vol. 31, 1907, pp. 1155. 1170) question the 

cholesterin theory and favor that of Potonie". See also Zaloziecki, Compt. rend. Cong. intern'at. pe"trolo, 

Bucarest, 1910, p. 718.
744 DATA OF GEOCHEMISTRY.

general conclusions are exceedingly important, but need to be more 

thoroughly tested before they can demand universal acceptance. 

The presumption, however, is strongly in their favor.

In any attempt to discover the genesis of petroleum the quantitative adequacy of the proposed sources must be taken into account. 

In such an inquiry superficial observations are deceptive, for one is 

apt to overrate the visible and productive accumulations which furnish the oils of commerce. These, seem large, but they are relatively 

insignificant. As Orton * has said, disseminated petroleum is wellnigh universal; the accumulations are rare. In certain districts the 

shales and limestones are generally impregnated with traces of bitumens, which seem at first sight to be insignificant, but which really 

represent enormous quantities. In the Mississippian ("sub-Carboniferous") limestones of Kentucky petroleum is generally present. 

If it amounts to only 0.10 per cent, each square mile of rock, with a 

thicknes's of 500 feet, would yield about 2,500,000 barrels of oil. 

Even more striking are the figures given by T. Sterry Hunt,2 who 

estimates that in the limestone of Chicago, with a thickness of 35 

feet, there are 7,743,745 barrels of oil to each square mile of territory. 

Figures like these, together with the computations, previously cited, 

made by Szajnocha relative to Galician petroleum, lead to the conviction that the formation of bitumens is a general process and by 

no means exceptional. Wherever sediments are laid down, inclosing 

either animal or vegetable matter, there bitumens may be produced. 

The presence of water, preferably salt, the exclusion of air, and the 

existence of an impervious protecting stratum of clay seem to be 

essential conditions toward rendering the transformation possible. 

Seaweeds, mollusks, crustaceans, fishes, and even microscopic organisms of many kinds may contribute material to the change. In some 

cases plants may predominate; in others animal remains; and the 

character of the hydrocarbons produced is likely to vary accordingly, just as petroleum varies in different fields. In one region we 

find chiefly paraffins, in another naphthenes, and in another nitrogenous or sulphureted oils. Such differences can not be ignored, and 

they are most easily explained on the supposition that different 

materials have yielded the different products. On this class of problems the chemist, the geologist, and the paleontologist must work 

together. Physics also is entitled to be heard; for, as D. T. Day 3 

has shown, petroleum, by simple filtration through fuller's earth, can

1 First Ann. Rept. Geol. Survey Ohio, 1890, chapter 11; Geol. Survey Kentucky, Report on occurrence 

of petroleum, etc., 1888-89.

3 Chemical and geological essays, 1875, p. 168.

s Cong. internat. p6trole, Paris, 1900, p. 53. See also J. E. Gilpin and O. E. Bransky, Am. Chem. Jour., 

vol. 44,1910, p. 251; and Gilpin and P. Schneeberger, Am. Chem. Jour., vol. 50,1913, p. 59. These authors 

show that fuller's earth exerts a selective absorption for unsaturated hydrocarbons and organic sulphides. 

See also C. Richardson, Jour. Inst. Eng. Chem., vol. 8,1916, p. 4, on the possible influence of colloidal clays 

in transforming petroleum into asphalt.
THE NATURAL HYDROCARBONS. . 745

be separated into fractions which differ in density and viscosity and 

are therefore of different composition. Such a filtration, or, more 

precisely, diffusion, must take place in nature wherever migrating 

hydrocarbons traverse permeable strata.

By whatever class of reactions petroleum is generated, it doubtless 

appears first in a state of dissemination. How does it become concentrated ? This question does not fall within the domain of chemistry, and can not be properly discussed here. 1 Probably circulating 

waters have much to do with the process, but whatever that may be 

the laws governing the motion of liquids must inevitably rule. The 

oils must gather in proper channels, moved by gravitation, or by 

hydrostatic pressure of waters behind or below them, or by the pressure of dissolved and compressed gases, and they accumulate in 

porous rocks or cavities under layers of impervious material. When 

the latter are lacking, or when the hydrocarbons enter large areas of 

porous rocks, they may be either evaporated or rediffused. Pressure, 

temperature, viscosity, and the character of the surrounding rocks 

must all be taken into account, and each productive area needs to be 

studied independently with reference to its local conditions.

In conclusion, I may be allowed to suggest that nearly all of the 

proposed theories to account for the origin of petroleum embody 

some elements of truth. SokolofFs cosmic hypothesis is sustained by 

the fact that hydrocarbons are found in meteorites. The volcanic 

hypothesis is sustained by the fact that hydrocarbons occur among 

volcanic emanations. The organic origin of petroleum, however, 

seems to be best supported by the geologic relations of the hydrocarbons, which are found in large quantities only in rocks of sedimentary 

character. Any organic substance which becomes inclosed within 

the sediments may be a source of petroleum, and when the latter 

happens to be rich in nitrogen, animal matter was probably the 

initial material. There is no evidence to show that any important 

oil field derived its hydrocarbons from inorganic sources.2

1 For a discussion of this problem, see H. Hofer, Das Erdol, 1906, p. 223. Also G. I. Adams, Trans. Am. 

lust. Min. Eng., vol. 33, 1903, p. 340; and D. T. Day, idem, p. 1053. Orton's reports, previously cited, 

con tain important contributions on this theme.

a The controversies relative to the genesis of petroleum have created a voluminous literature, of which 

only the main points have been considered here. For an excellent summary of the subject, see Engler 

and Hofer's great treatise Das Erdol, vol. 2, Leipzig, 1909, pp. 59-142. On the genetic relations between 

petroleum and coal, see David White, Jour. Washington Acad. Sci., vol. 5,1915, p. 1S9. In a recent paper 

(Jour. Am. Chem. Soc., vol. 41,1919, p. 1190) C. F. Mabery has shown that nitrogen is an almost invariable constituent of petroleum, which proves the organic origin of the oil.
CHAPTER XVII. 

COAL.

ORIOIN OF COAk.

Although doubts may exist as to the origin of petroleum, there are 

none whatever as to the essential origin of coal. It is obviously derived, from vegetable matter, by a series of changes which are plainly 

traceable, even though their mechanism is not fully understood. 

Vegetation, peat, lignite, soft coal, anthracite, and some graphitic 

minerals forni a series of-substances which grade one into another in 

an unbroken line, reaching from complex organic, oxidized compounds at one end to nearly but not quite pure carbon at the other. 

All these bodies, except perhaps the last, are indefinite mixtures 

which vary in composition, and it>is therefore impracticable to write 

chemical equations that shall properly represent their transformations. Such equations, to be sure, have been suggested and written, 

but they embody fallacies which are easily exposed. They start 

from the assumption that the principal initial compound contained 

in vegetation is cellulose, a definite carbohydrate of the formula 

C8H1005 , which gradually loses carbon dioxide, marsh gas, and water, 

and so yields the series of products represented by the different kinds 

of coal. 1 This assumption, like most other assumptions of its class, is 

partly true and partly false. Cellulose is an important constituent 

of vegetable matter, but it stands by no means alone. When it 

decays, it loses the substances named above and it also undergoes 

other changes which are difficult to measure. In every swamp or 

peat bog the waters are charged, more or less heavily, with soluble 

organic matter of which the written reactions take no account. This 

soluble matter is found in the waters of all bogs and streams, and it 

is just as much a factor in the real reactions as are the gaseous products or the solid carbonaceous residues.

If, instead of the composition of cellulose, we begin with the composition of wood, we shall have a better starting point for our series 

of derivatives. Wood or woody fiber is by no means the only substance to be considered, but it is the most important one, and its 

ultimate composition has been well determined. Its proximate comi The formula CcHio05 represents only the empirical composition of cellulose, and not its true molecular 

weight. According to A. Nastukoff (Bcr. Dcutsch. chem. Ocsell., vol. 33,1900, p. 2237), the true formula 

is probably -lOCcHioOo, or Cw>SmOa.oo- This may be an exaggeration, but the molecular weight of cellulose 

is certainly high. For an attempt to write chemical equations representing coal formation, see J. F. Hoffmann, Beitr. Gcophys., vol. 7,1905, p. 327.

746
COAL. 747

position is not so clearly known, but certain available facts are pertinent to the present discussion. It contains cellulose, C6H1005 , and 

a substance known as lignone, lignin, or lignocellulose, in about 

equal proportions, together with other minor organic constituents, 

such as gums and resins, 1 and .some inorganic matter which forms its 

ash. To lignocellulose, according to Cross and Bevans,2 the formula 

C12H1809 may be assigned; and it is best represented by jute fiber, 

which consists almost wholly of this substance.

If, now, we compare the percentage composition of cellulose, lignocellulose, and wood, we shall see how unsafe it is to write equations 

intended to show the derivation of coal upon the basis of cither definite compound alone. The data are as follows:

Composition of cellulose, lignocellulose, and ivood.

A. The composition of cellulose, calculated from its formula.

B. The composition of lignocellulose, similarly computed.

C. The average composition of twenty-four woods, analyzed by Pctcrscu and Scho'cllcr, Licbig's AnnaJen , vol .17,1836, p. 139, .Samples dried and finely powdered.

D. Average of thirty-six analyses of five different woods, by E. Chovanclicr, Annalcs clihn. pliys., 3d 

scr-., vol. 10,1844, p. 129. Samples dried in vacuo at 140°.

E. Average of eight analyses of woods by W. Baer, Jahresb. Chemie, 18*17-48, p. 1112. Ash from 0.53 to 

2.03 per cent.

F. Average of seven Danish woods, analyzed by E. Gottlieb, Jour. Chcm. Soc., vol. 40, ISS-l, p. 477 

(abstract). Dried at 115°.

G. Average composition of five acrogcn plants, of the genera Lycopodium, Equisctum, Aspidium. and 

Cijailiea, by G. W. Hawes, Am. Jour. Bci., 3d scr., vol. 7,1874, p. 585. In Equisetum the ash ran as luga 

as 11.82 per cent. . .

c. ..................

H.. .................

0. ..................

A

44.43

6.22

49.35

100. 00

B

47. 06,

5.89

47.05

100. 00

C

49.31

6.29

44.40

100.00

D

51.21

6.24

42.55

100.00

E

49.16

6.10

44.74

100. 00

F

49.76

6.14

44. 10

100. 00

V,

48.83

6.37

44.80

100. 00

All of these analyses are recalculated to an ash-free basis. In the 

table, for uniformity, the nitrogen is added to the oxygen. Chevandier found, in mean, 1.10 per cent of nitrogen in his woods, hut Gottlieb obtained only 0.04 to 0.10. In Hawes's analyses the nitrogen 

ranged from 1.21 to 2.17 per cent. The differences between the wood 

analyses are principally due to differences in drying.

From these figures we see that cellulose contains about 5 per cent 

more oxygen than carbon, while in wood the reverse statement is very 

nearly true. Even lignocellulose contains less carbon than is actually 

found in wood. The figures for wood given in column F approximate 

very nearly to the formula C6H9 04 , and that expression might bo 

used were wood a definite substance. Its employment, however, is

» See M. Singer, Monatsh. Chemie, vol. 3, 1882, p. 395, on the subordinate constituents of wood. The 

subject is one which can not be properly developed here. 

2 Jour. Chcm. Soc., vol. 55,1889, p. 199.
748 DATA OF GEOCHEMISTRY.

more likely to cause misapprehension than to aid in the elucidation of 

problems. At best it can only be taken as a convenient collocation 

of symbols, more easily borne in mind than the actual percentages.

It is generally admitted, I think, by all competent investigators 

that coal originated from vegetation which grew in swampy or 

marshy places. As the vegetation died it underwent a partial decay 

and was buried under successive layers, either of matter like itself or 

else of sediments such as clay. In that way it was protected from 

complete atmospheric oxidation and at the same time subjected to 

a gradually increasing pressure and doubtless to some heat generated thereby. The vegetation was of many kinds trees, ferns, 

grasses, sedges, mosses, etc. and these all contributed variously to 

the formation of the future coal. Trees standing erect within a bed 

of coal, their roots still remaining embedded in an underlying stratum 

of clay, tell a part of the story. Fossil ferns, and even the remains 

of microorganisms, also add their testimony to what has occurred. 

In some cases beds of lignite represent submerged forests; and in 

others, as shown by many geologists, the coal was probably formed, 

not from vegetation in place, but from drifted materials, a condition, 

however^ which does not affect the chemistry of the carbonizing 

process. The slow decay of the buried substances is the essential 

thing for the chemist to consider. With the vegetable matter some 

animal remains were undoubtedly commingled, helping to increase the 

nitrogen content of the coal; and the ash of the latter was augmented 

by more or less inorganic sediment, derived from the wash of the 

land in times of flood. Certain coals and carbonaceous rocks, such 

as cannel, Boghead, oil shale, etc., are attributed by H. Potonie 1 to 

the decomposition of "sapropel," a sort of slime made up largely of 

gelatinous algae, mixed with some animal remains. This view has 

received much acceptance, but E. C. Jeffrey 2 has shown that in 

some cases at least the supposed fossil algse are really the spores of 

vascular cryptogams.

In their memoir on the origin of coal D. White and R. Thiessen 3 

give an excellent summary of the diverse theories upon the subject. 

Their conclusions, based on field studies and microscopic investigations, are that "all coal was laid down in beds analogous to the peat 

beds of to-day." They regard it as "chiefly composed of residues 

consisting of the most resistant components of plants, of which 

resins, resin waxes, waxes, and higher fats, or the derivatives of the 

compounds comprising them are the most important." The algal

1 Die Entstehung dcr Steinkohle, Berlin, 1910. See also citation in the preceding chapter and the references to the work of Bertrand and Eenault. Also H. Stremme, Monatsber. Deutsch. geol. Gesell., vol. 59, 

1907, p. 153.

2 Proc. Am. Acad. Arts and Sci., vol. 46, 1910, p. 273. For a recent paper by Jeffrey on the origin of 

coal see Jour. Geology, vol. 23,1915, p. 218. 

3 The origin of coal: Bull. U. S. Bur. Mines No. 38, 1913. Another important work on the subject is 

by O. Stutzer, Kohle (Allgemeine Kohlengeologic), Berlin, 1914.
COAL. 749

~ and gelosic theories of the origin of coal they dismiss as undemonstrated. The views of White and Thiessen probably represent the 

general consensus of opinion.

The oil shales, from which shale oil is distilled, especially in Scotland, seem to be, in one sense at least, intermediate between coal 

and petroleum. That is, they may contain some original oil, but 

most of the product is the result of the destructive distillation of 

matter analogous to certain varieties of bituminous coal or of asphalt, 

just as in the production of illuminating gas the heavier hydrocarbons are broken down, yielding lighter oils', tarry matter, and gas. 

Ammoniacal solutions are also produced and form a valuable part 

of the yield. According to D. E. Winchester,1 who has studied the

* oil shales of Colorado and Utah, the shales contain an immense amount 

of vegetable matter, with some remains of fishes and insects. From 

these substances the oil-producing hydrocarbons were evidently

 * derived.

A moment's consideration will suffice to show that the process of 

vegetable decay could not have been uniform. The softer plant tis-

~ sues decompose most rapidly; the more compact ligneous masses 

endure much longer. Even the trunks of trees must exhibit similar 

variations, for woods differ in hardness and compactness, and the 

resinous varieties will rot the slowest of all. The resins themselves 

show the minimum of change, and where they were most abundant 

their fossil remnants are found. Amber, fossil copal, the waxes 

found in peat bogs, and a multitude of similar substances have been 

thus preserved. In lignite and bituminous coal aggregations and 

often large masses of resinous bodies not infrequently occur, and in a 

disseminated form, unrecognizable by the eye, they must be almost 

invariably present. Their quantity, of course would depend upon 

the exact character of the vegetation from which a given coal bed 

was formed.

The nature and distribution of the fossil resins deserve much more 

careful study than they have yet received. Much rarer than the 

resins are the salts of organic acids, which are sometimes found in 

coal, especially in lignite. Three of these are well-defined species, 

namely, whewellite, calcium oxalate; humboldtine, ferrous oxalate; 

and mellite, the aluminum salt of mellitic acid, A1C606 .9H20. Compounds of this class are significant in showing the range and variety 

of the reactions which take part in the formation of coal. Oxalic 

acid is easily formed from cellulose, and it is therefore surprising that 

its salts are not more frequently discovered in peat or coal. The 

soluble oxalates, of course, would be leached away; but calcium 

oxalate is insoluble and ought to be more common.

i Econ. Geology, vol. 12,1917, p. 505; Bull. U. S. Geol. Survey Nos. 641-F, 1916, and 691-B, 1918. Tho 

J last bulletin contains an extensive bibliography of the subject. On the Scottish oil shales and torbanite, 

seeH. R. J. Conacher, Geol. Mag., 1917, p. 93.
750 DATA OF GEOCHEMISTRY.

In addition to its '.organic constituents coal :also 'contains .more or 

less inorganic matter which on combustion .remains as ash. This 

was originally for the most part of sandy or clayey character., of 

variable composition; but rarer impurities are sometimes found. 

The occurrence >of ;gold, silver., vanadium, and uranium was already 

noticed in Chapter XV -of this work; :and to these, according to 

S.tutzer, -molybdenum must be added. Stutzer l .also -mentions, as 

having been found in coal, >millerite, cinnabar,, chalcopyrite, bornite, 

sphalerite, galena, ,and malachite.. Pyrite or marcasite is commonly 

present, and -often in annoying '-quantities.. The almost 'Omnipresent 

radium was detected in certain Alabama coals by S.. J. Lloyd .and

J. :Cunningham. 2

PEAT.

The first stage in the .development of ooal -from vegetable .matter 

seems to be -represented, :at least approximately, by the formation of 

peat. The process, as observed, has already been outlined. Mosses, 

grasses, and other plaints -any plants, in fact, which can thrive in 

marshes grow., die, and are buried, layer after layer. On the surface -of a bog we :see the growing plants; .a -little below the surface, 

their recognizable remains.; .stiM -deeper, we find .a black, semigelatinous substance from which the vegetable structure has largely disappeared.3 This substance, saturated with moisture, is peat; -dried, 

it becomes a valuable fuel.

Many analyses -of peat have been made, and, as might be -.expected, 

they vary widely. The following series by J. Websky 4 is -especially 

suggestive. The samples were dried .at 100°, and the analyses calculated .on an .ash-feee basis.

Analyses of sphagnum and peat.

A. Sphagnum, -the-chief plant of the peat bogs. 

B. Light peat, near surface. 

C. Light peat.

X>. .Moderately light peat.

E, F. Black peat.

G. Heavy brown peat.

C. .....................

H.....................

 O.....................J

N... ........................

A '

49.88

.6.54

42. 42

1.16

100. 00

03 i

.50.:33

5. .99

42. '63;

1.05 ' 

100/00

' -C

50. 86 1

.5.80

42. :57

.,77'

100. =00 '

D

59. .71

5. 27 '

'32. 07

2. 95

100. -00

E

59. 70

5.70

38. 04

1. 56

100.00

'F

59.71

5.27

;32.-07 ;

2. 95

100.00

 G

62. 54

6. 81

59. 24

1. 41

100.00

The progressive increase in carbon in passing from sphagnum to 

heavy peat is clearly -shown.

1 Op. cit., pp. 19, 193. 

- 2 Am.-Ohem. Jour.,-vol.-50,1913, ;p. 47.

15 -On the rapidity of-formation-of peat, see a summary'by-G. JK. Ashley, Econ. C.cology, vbl.^lOOT.ip. 34. 

« Jour. prafct.'Ohemie, vol.'92,1864, p. "65. <
.GOAL. - 75.1

A few other analyses of peat may.be profitably cited as follows: 1

Analyses of peat.

A. From Thesy, France. Analysis by Marsilly, Annales clcs mines, 5th ser., vol. 12, p. 406. Dried 24 

hours in vacuo. " 

. J3. Prom Camon, France. Also by Marsilly, who.gives seven analyses in all. Dried 24 hours in vacuo.

C. From Hor in Schonen. Analysis by O. Jacobscn, I j.ebig's Annalen, vol. 157,1871, p. 240. Dried 

at 100°.

D. From a lake in Cashmere. Analysis by C. Tookcy. Sec Percy's Metallurgy, vol. 1,1S75, p. 200.

E. Average often analysis cited by Roth,.Allgcmcinc chcmischc Geologic, vol. 2, p. 642.

C............ .........................

H........ ....... ......................

0.......... ...........................

N.......... ..........................

Ash... ................................

A

50. 67

5.76

34.95

1 Q°

6. 70

100. 00

p.

46.11

5.99

35.87

2.63

9.40

100. 00

0

51. 38

6. 49

35.43

1.68

5.02

100. 00

:D

37. 15

4.08'

93 48

2.02

33. 27

100. 00

E

51. 97

6.05

34 09

1 34

6. 61

100. 00

Reduced to an ash-free basis, in order to compare the organic matter with that of wood, the analyses ^assume the following form:

Analyses of peat reduced to asli-frcc 'basis.

G... .......... .........................

H.....................................

o.......... .........:. ................

N..... ...............................

A

54.31

6.18

'37. 46

2.05

100. 00

B

50.89

6.61

39. 58

2.92

100. 00

C

54. 10'

6.83

37. 30

1.77

100. 00

D

55.67

' 6.11

3'5. 19

3.03

100. 00

E

55.65

 6.48

36.43

1.44

100. 00

As compared with the data already .given for wood, these figures 

show an increase in carbon, a decrease in oxygen, and a notable enrichment in nitrogen. The last gain may be partly from animalmatter.

The nature of the -changes which have taken place in .the transformation of vegetable matter into peat is imperfectly understood, 

When ligneous fiber decays it yields an amorphous mixture -of substances which are known collectively as humus, ,and .are partly of 

acidic nature. 'The substances .are very ill-defined bodies, although 

various formulae have been assigned to .them, 'but none can be said

1 For still other analyses, see Both and Percy, as cited, and vol. 1 of Grove and Thorp's Chemical technology, -pp. 14-20. -In the latter work, p. 16, will-be found 27 analyses'Of-peat ashes, -by Kane and Sullivan. 

Pctcrson and Ncssler CNeues Jalirb.,1881/p. 82).give 17 ultimate analyses of German'peat, mth.soparato 

analyses of the ash. In 'a paper by H. B. Kummcl (Eeon. Geology, vol. 2, 1907, p. 24), .there.are many 

technical analyses of New Jersey <peat, -With calorimctric data. On.the mechanism of peat .formation, sco 

N. S. Shaler, Sixteenth Ann. Ropt. U. S. .Geol. Survey, pt. 4,1895. p. 305. An important-general .paper 011 

peat, its rate of growth, its resins, etc., by E. Angus Smith, is'.givcnln Mom. Lit. Philos. See. Manchester, 

1876, p. 281. See.also T. .R. Jones, Proc. Geologists' Assoc., vol. 0,13SO, p. 207, and-C. A. 'Davis, Rcpt. State 

Board Gcol. Survey Michigan, 1905, p. 97, and Econ. Geology, vol. 5,1910,'p. 37. Davis also.has a chapter 

on peat in White and Thicssen's memoir.
752 DATA OF GEOCHEMISTRY.

to be established. The acid portions dissolve in alkaline solutions, and so are partly washed away; but the salts formed with lime 

and iron, being insoluble, probably remain behind. The ash of peat 

is commonly rich in lime, not as carbonate, and also in iron, the latter 

appearing often in large beds of bog ore. The formation of the humus 

appears to take place by a fermentative process, which eliminates 

some carbon, hydrogen, and oxygen in the form of carbon dioxide, 

marsh, gas, and water; and micro-organisms play some part in producing the changes observed. On this point, however, there is 

some doubt, Friih and Schroter, 1 for example, regarding the microbian 

influence is very small.

Broadly speaking, with temporary disregard of minor constituents, a bed of peat may be said to consist of water, inorganic matter, 

vegetable fiber, and humus. From this point of view H. Borntrager 2 

has made analyses of peat, finding in the black varieties from 25 to 

60 per cent of humic substance, with 30 to 60 of fiber. Two of his 

analyses are as follows:

Analysis of peat (Borntrager).

A. Liglit-colored peat, Hannover. Mean of two analyses. 

B. Black peat, Oldenburg.

Water. . .........................................................

Ash.............................................................

Fiber ....:.:............

A

29.50

3.05

54.95

12.50

100. 00

B

20.0

3.0

47.0

30.0

100. 0

In the light-colored peat evidently the changes have not gone so 

far as the other.

In some peat beds isolated masses of humic substance are found, to 

which the mineralogical name dopplerite has been.given.3 According 

to F. G. Kaufmann,4 this substance is identical with the part of peat 

which dissolves in caustic alkali solutions, and he therefore regards 

peat as a mixture of dopplerite with partly decomposed vegetable 

matter. He gives analyses by Muhlberg of dopplerite from the peat 

of Obbiirgen, Canton Unterwalden, Switzerland, which, in mean, are 

as follows:

1 Die Moore der Schweiz, Bern, 1904, a superb quarto monograph issued by the Swiss Geological Commission. Sec especially chapter 3, on peat. The volume contains a bibliography of 280 titles. On the 

microbian side of the question, see B. Renault, Compt. Rend., vol. 127,1898, p. 825.

2 Zeitschr. anal. Chemie, vol. 39,1900, p. 694: vol. 40,1901, p. 639.

3 See Dana, System of mineralogy, 6th ed., p. 1014. For additional data on dopplerite, see C. Claesson, 

Chem. Zeitung, vol. 22,1898, p. 523, and W. Alexejeff, Zeitschr. Kryst. Min., vol. 20,1902, p. 187. 

< Jahrb. K.-k. geol. Reischsanstalt, vol. 15,1865, p. 283.
COAL. 753

Average composition ofdopplerite.

C............................................................. 56.46

H............................................................. 5.48

0+N........................................................ 38. 06

100. 00

The organic portion of dopplerite from the original locality at 

Aussee, Styria, gave W. Demel 1 nearly identical results, and he 

assigns to the substance the formula C12H1406 . Its actual occurrence in peat, however, is thought by Demel to be as a lime salt and 

not as the free organic acid.

Peat also contains some ill-defined resinous substances, which are 

extractable by solution in hot ether or alcohol. In 0. Jacobsen's 

experiments 2 their quantity ran from 2.5 to 3.26 per cent. A crystalline hydrocarbon, fichtelite, is sometimes found in the buried coniferous woods of peat beds. It appears to have been derived from the 

terpenes of the wood, but its exact nature is uncertain.3 C. Hell 

assigned it the formula 4 C30H54 , and L. Spiegel has argued in favor 

of 018H30 . The possible derivation of petroleum-like hydrocarbons 

from peat was discussed in the preceding chapter.

In its youngest forms peat is loosely compacted, but as it accumulates the under portions become compressed, and what was once a 

foot thick may shrink to 3 inches.5 In various localities peat beds 

have been found buried beneath sediments or drifts. Dawson 6 mentions peat underlying boulder clay in Cape Breton Island, and beds 

covered by drift have been reported in Iowa.7 In all probability 

these occurrences are not exceptional, and the pressure developed by 

the covering material doubtless aids in the transformation of peat 

into coal.8

LIGNITE.

Under the names lignite and brown coal a number of substances 

are comprised which lie between peat on one side and bituminous 

coal on the other. The names are conventional and not always 

appropriate, for some lignites are not ligniform, and others are not

i Ber. Deutsch. chom. Gesell., vol. 15,1882, p. 2961.

»Liebig's Annalen, vol. 157,1871, p. 240. See also Mulder, idem. vol. 32,1839, p. 305.

a On fichtelite, soe T. E. Clark, Liebig's Annalen, vol. 103, 1857, p. 236; C. Hell, Ber. Deutsch, chem. 

Gesell., vol. 22,1889, p. 498; E. Bamberger, idem, p. 635, and L. Spiegel, idem, p. 3369. Also M. Schuster, 

Min. pet. Mitt., vol. 7,1885, p. 88.

4 Reduced to simpler, comparable terms, those formula: become, respectively, CuJIa and CuH^. The 

difference is slight.

* See G. H. Ashley, Econ. Geology, vol. 2,1907, p. 34.

8 Acadian geology, 2d ed., p. 68.

i See T. H. MacBride, Proc. Iowa Acad., vol. 4,1897, p. 63; and T. E. Savage, idem, vol. 11, 1903, p. 103.

B On American peats, see H. Ries, Fifty-fifth Ann. Rept. New York State Mus., 1903, p. r55; A. L. 

Parsons., idem, Fifty-seventh Ann. Rept., vol. 1, 1905, p. 16. Parsons cites many analyses. In Ann. 

Rept. State Geologist New Jersey, 1905, p. 223, W. E. McCourt and C. \V. Parmalee describe peat deposits 

and give a bibliography of the subject. See also R. Chalmors, Min. .Res. Canada, 1904, Bull, on Peat, for 

Canadian data. A partial bibliography of peat is given by J. A. Holmes in Bull. U. S. Geol. Survey No. 

290, .1906, pp. 11-15.

113750° 19 Bull. 695 48
754 DATA or GEOCHEMISTRY.

brown, but black. Geologically, they are modern coals, Tertiary and 

Mesozoic, and their composition bears some relation to their age. 

The most recent approach peat; the oldest are nearer the true 

coals. This is a general, not an. absolute relation, for in some cases 

lignites have been transformed into apparently bituminous coals, or 

even, by metamorphic action, into anthracitic varieties. 1 In many 

instances fossil charcoals have been observed, resembling ordinary 

charcoal; and these owe their peculiarities, perhaps, to forest fires, 

caused either by lightning or by eruptions of. igneous rocks. 2

Among the lignites several distinct varieties exist, which have 

received characteristic names, as follows:

1. True or xyloid lignite. This is essentially fossil wood in which 

the ligneous structure is more or less perfectly preserved.

2. Earthy brown coal. This variety is earthy in structure, as its 

.name indicates, and it is often accompanied by mineral resins or 

fossil hydrocarbons.

3. Common brown coal. The common, compact form of lignite, 

and the one best known as a fuel.

4. Pitch coal, a compact yariety, so named for its peculiar luster.

5. Glance coal. A hard and very compact form of lignite, most 

nearly resembling the Carboniferous coals.

6. Jet. A very hard variety, probably derived from the fossilization of coniferous wood. 3 Used for jewelry and other' ornamental 

purposes.

As might be supposed, the lignites exhibit a wide range of variation 

in their composition. The following analyses, selected from a table 

in Percy's Metallurgy, 4 show this fact clearly. They have been recalculated upon an ash-free, water-free basis.

Analyses of foreign lignites.

A. From Tcuditz, Germany. Analysis by Wagner.

B. From Sardinia. Analyst not named.

C. From Schonfeld, Bavaria. Analysis by Nendtwich.

D. From European Turkey. Analyzed by W. J. Ward in Percy's laboratory.

E. From Sardinia. Analyzed by C. Tookey, in Percy's laboratory.

c.................. ....................

H..... ........ ...... ..................

0+N...... ............................

A

57.02

5.94

37.04

100. 00

p.

63.71

5.05

31.24

100.00

c

69.82

5.90

24.28

100. 00

D

75.08

5.44

10.48

100.00

E

82.26

6.52

11 22

100. 00

1 These transformations have been doubted by Donath, whose work is cited later.

2 See, for example, A. Datibre>, Cbmpt. Rend., vol. 19 1844, p. 126, on "mineral charcoal" from the 

Saarbrucken coal field.

»See P. E. Spielmann, Chem. News, vol. 94,1906, p. 281; vol. 97,1908, p. 181. For an analysis of Spanish 

jet see J. B. Boussingault, Annales chim. phys., 5th ser., vol. SJ, 1883, p. 383. The latter memoir contains 

many other analyses of fossil combustibles. .

* 1875 edition, vol. 1, pp. 312-313. From a table of 41 analyses.
COAL. 755

For technical purposes coal analyses are commonly reported in a 

different form. Moisture and ash are important factors to consider, 

and so, too, is the distinction between the "volatile matter" and the 

"fixed carbon." In lignites the moisture is usually very high, for 

these coals are peculiarly hygroscopic. Like other coals, they also 

contain sulphur, which is partly organic, partly present as inclosures 

of pyrite or marcasite, and partly in the form of sulphates, such as 

gypsum.1 The following analyses from the reports of the fuel-testing plant of the United States Geological Survey 2 are fair examples 

of the technical mode of statement. All samples were air dried.

Analyses of American lignites.

A. Brown lignite, Williston, North Dakota.

B. Lignite from Texas.

C. Lignite from Tesla mine, Alamcda County, California.

D. Lignite from Wyoming.

E. Black lignite from Red Lodge, Montana. A coal of doubtful cliaracter. Not certainly lignite.

0

Ash.... ..............................

A

16.70

37.10

39.49

6.71

100. 00 

.63

B

22.48

31.36

26.73

19.43

100. 00 

.56

c

18.51

35.33

30.67

15.49

100. 00 

3.05

D

17.69

37.96

39.57

4.79

100. 00 

.63

E

9.05

36.70

43.03

11.22

100. 00 

1.76

The elementary analyses of these coals, when ash, mositure, and 

sulphur are thrown out, show less variation.

Elementary analyses of American lignites.

c..... .................................

H....................................

N.....................................

o.... ................................

A

72.62

4.93

1.20

21.25

100.00

B

73. 63

5.07

1.35

19.95

100.00

c

75. 19

6.18

1.04

17.59

100. 00

I)

75.97

5.36

1.41

17. 26

100. 00

E

77. 47

5.44

1.75

15.34

100. 00

For further comparison of the lignites with other fossil fuels, the 

subjoined averages will be useful. The data are reduced to an ashfree and water-free standard.

1 The resinoid substances which have been named quisqucite, tasmanitc, and trinkerite are rich in 

organic sulphur compounds of undetermined character. See Dana, System of mineralogy, Cth ed., p. 1010.

2 Prof. Paper No. 48, pt. 1, and Bull. No. 290,1900. Analyses made under the direction of E. E. Sommermeier.
756 DATA OF GEOCHEMISTRY.

Average analyses of lignites.

A. Average of 22 Texas lignites, analyzed by Magnenat and Wooten. Dried at 105°-. From E. T. 

Bumble's Report on the brown coal and lignite of Texas: Geol. Survey Texas, 1892, p. 213. This volume 

contains many technical analyses of lignites and also tables of analyses of German, Austrian, and Italian 

brown coals.

B. Average of 10 analyses from the report of the fuel-testing plant of the United States Geological 

Survey already cited.

C. Average of 29 lignites from various parts of the world. Analyses by C. Tookey and W. J. Ward in 

Percy's laboratory. Percy's Metallurgy, vol. 1, pp. 312-321.

. c......................................................

H... ................................................. o................. .......................................

N..... ..................................................

A

69. 82

4.72

] 25.46

'

100. 00

B

74.86

5.32

18.51

1.31

100. 00

C

74.17

5.67

} 20.16

'

100.00

Data of this kind might be almost indefinitely multiplied.1 

The resinoids and fossil hydrocarbons are especially abundant in 

brown coals, both as visible masses and in a disseminated condition. 

Organic solvents, such as benzene, will extract matter of this kind 

from lignite, but the substances thus obtained are not of definite composition. In some cases oily fluids exude from brown coal,2 although 

instances of this kind are probably rare. Solid bodies are the rule. 

An extreme example of extractive matter in coal is that reported by 

Watson Smith,3 who, in a Japanese lignite, found 9.5 per cent of substance soluble in benzene.

In their Jbehavior toward reagents the lignites are more akin to 

peat than to the Carboniferous coals. Like peat, they contain humic 

compounds which are soluble in solutions of caustic alkalies. According to E. Fremy,4 peat yields abundant "ulmic acid" to alkaline 

solvents, xyloid lignite yields less, and compact lignite little or none 

at all. The bituminous coals and anthracite are insoluble in alkaline 

solutions. Occasionally these humic bodies are found hi remarkable 

concentrations. The ''paper coals" of Russia, for example, contain layers of humic matter, which is soluble in ammonia.5 In the 

brown coal of Falkenau, Bohemia, C. von John 6 found a native 

humus, soluble in ammonia or sodium carbonate solution, which 

had approximately the composition C46H46025 . Von John cites 

other examples reported by other observers. Furthermore, the

1 See the great monograph by C. Zincken, Die Physiographic der Braunkohle, Hannover, 1867; and its 

Ergilnzung, published at Hallein 1871. -In Grove and Thorpe's Chemical technology, vol. 1, many analyses 

are given; and others are cited in F. Fischer's Chemische Technologic der Brennstofle, Braunschweig, 

1897, vol. 1. E. F. Burchard, in Proc. Sioux City (Iowa) Acad., vol. 1,1904, p. 174, has reported data for 

some Nebraska lignites.

2 See A. A. Hall, Jour. Soc. Chem. Ind., vol. 26,1907, p. 1223; J. B. Cohen and C. P. Finn, idem, vol. 31, 

1915, p. 12; P. P. Bedson, idem, vol. 26,1907, p; 1224. White and Thiessen (The origin of coal, p. 274) 

regard the oils in coal as derived from spore exines and pollen grains.

3 Jour. Soc. Chem. Ind./vol. 10, p. 975, 1891.

< Compt. Eend., vol. 52,1861, p. 114.

s See R. Zeiller, Bull. Soc. ge"ol. France, 3d ser., Vol. 12, 1884, p. 680.

eVerhandl. K.-k. geol. Reichsanstalt, p. 64, 1891.
COAL. 757

pigment known as Cassel brown is a fossil humus from the Tertiary 

near Cassel, Germany.1

Fremy found that lignite was also soluble in alkaline hypochlorites, 

while the true coals were not. It was also strongly attacked by nitric 

acid, with conversion into a yellow resinous body, soluble in an 

excess of the reagent or in solutions of the alkalies. Bituminous coal 

and anthracite, on the other hand, were feebly attacked, anthracite 

.in particular with extreme slowness. These coals, however, dissolved in mixtures of nitric and sulphuric acids, yielding solutions 

from which water precipitated a humus compound. Woody tissue, 

heated during several days to 200°, became comparable with lignite 

in its behavior toward reagents.

Since Fremy's time the action of nitric acid and other oxidizing 

agents upon coal has been studied by various investigators. E. Guignet,2 for example, found that nitric acid acted upon coal with the 

formation of products more or less analogous to the nitrocelluloses, 

arid similar observations were recorded by K. J. Friswell.3 A committee of the British Association 4 also conducted some experiments 

upon the proximate constitution of coals. They not only studied the 

action of solvents to some extent, but also examined the action of 

hydrochloric acid and potassium chlorate upon coal. That powerful 

oxidizing mixture produced compounds which resembled the chlorinated derivatives of jute fiber. The work of the committee seems 

never to have been pushed to completion.

The researches thus briefly summarized, it will be observed, relate 

partly to lignite and partly to other coals. They suggest relations 

between the coals and vegetable fiber, but for several reasons they 

are inconclusive. The records are often inexplicit, and the experiments are not all strictly comparable. When nitric acid, for example, 

is employed as a test reagent, it should be under commensurable conditions, such as uniform fineness of subdivision on the part of the 

coal and equality of concentration on .the side of the acid. Time and 

temperature also must be taken into account. A hot, strong acid, 

applied to a finely powdered coal, would act differently from a cold, 

weak acid on coarser material. To neglect of details like these some 

of the discordances in the records are probably due.

In recent years E. Donath and his associates 5 have studied one 

phase of the nitric acid reaction with much care. Dilute nitric acid,

1 See a recent description by P. Malkomesius and R. Albert, Jour, prakt. Chcmic, 2d ser., vol. 70,1904, 

p. 509..

2 Compt. Rend., vol. 88, 1879, p. 590.

8 Proc. Chem. Soc., vol. 8, 1892, p. 9. W. C. Anderson and J. Roberts (Jour. Soc. Chem. In'l., vol. 17, 

189S, p. 1013) have also studied the action of nitric acid on coal and made several analyses of the "coal 

acids" so obtained.

< Ann. Rept. Brit. Assoc., 1894, p. 246; idem, 1896, p. 3<!0. '

6 Donath, Chem. Zeitunp;, 1905, p. 1027, and Zeitschr. anorg. Chemie, 1906, p. 057. Donath and II. Ditz, 

Oestcrr. Zeitschr. Berg- u. Huttenw., vol. 51,1903, p. 310. Donath and F. Briiunlich, Chem.Zeitung, 190-1, 

pp: 180, 953.
758 DATA OF GEOCHEMISTRY.

one part to nine of water, at a temperature of 70°, will attack lignite 

vigorously, but is without action upon bituminous coal. Even a 

brown-coal "anthracite," a product of contact me.tamorphism by an 

intrusion of phonolite, behaved like ordinary lignite toward nitric 

acid. From evidence of this kind Donath concludes that lignite and 

true coal are chemically unlike and of dissimilar origin. They 

behave differently toward reagents, and yield.different products upon 

destructive distillation. Neither by time, according to Donath, nor 

by heat, can lignite be transformed into coal.. Lignite, .he. thinks, is, 

derived from materials rich in lignocellulose, as shown by the presence of humic compounds in it. The true coals, on the other hand, 

were formed from substances which were either free from woody 

fiber, or nearly so. In the formation of bituminous coal, which is often 

rich in nitrogen, the proteids of animal matter probably took part.

It would be premature, I think, to accept Donath's conclusions 

throughout, but his evidence; taken together with that of earlier 

investigators, shows distinct chemical differences between the lignites 

and the coals. In lignites the humic compounds are readily detected, 

but in coal they are less apparent. .Nitric acid acts easily on lignite, 

but with much less vigor upon bituminous coal or anthracite. How 

far the latter substances are derivable from the former, however, is a

separate question.

BITUMINOUS COAL.

In composition, at least empirically, the bituminous coals lie 

between the lignites and anthracite. To some extent they overlap 

the lignites, so that it is not'always easy to say where one group 

ends and the other begins. The following analyses of bituminous 

coals, all of Carboniferous age, are taken from the reports of the fueltesting plant of the United States Geological Survey. They are 

selected in order to show something of the recognized variations. 1

First, there are the conventional proximate analysesProximate analyses of bituminous coals.

A. Ehrenfeld, Pennsylvania. Bull. No. 290, p. 179.

B. Brace, Pennsylvania. Idem, p. 184...

C. Vlgo County, Indiana. Idem, p. 109. ~ .

D. Altoona, Iowa. Prof. Paper No. 48, p. 223. 

F. Shawncc, Ohio. Bull. No. 290, p. H5. 

F. Staunton, Illinois. Idem, p. 03.

Fixed carbon. . ................

Ash..........................

A

3.51

16.82

73.04

6.63

100. 00 

.94

B

2.61

34.92

56.30

6.17

100. 00 

1.26

C

9.55

36. 19

43.65

10. 61

100. 00

3.72

D

4.52

40.96

38.99

15.53

100. 00 

6.83

E

9.90

33. 66

44. 86

11. 58

100. 00 

1.81

F

13.72

36. 24

39.72

in oo

100.00 

3.96

 . ._|

1 The high moisture of these coals is due to the fact that the samples were sealed up immediately after 

collection in the mines and were not dried: -Many analysesof American coals are given in Bull. U. S. Bur. 

Mines, No. 22, 1913, by N. W. Lord. See also Bull. 85, 191-1. for many other analyses. -' 
COAL. 759

 With one exception the volatilizable part of these eoals is less in 

amount than the fixed carbon. With the lignites the reverse statement is generally true. The ultimate analyses of«the same coals, 

recalculated to a water, ash, and sulphur free basis, are as follows:

Ultimate analyses of bituminous coals.

.

c. ...........................

H.. ..........................

N.. ............. ..............

o. ...........................

A

90.78

4.69

1 40

3.13

100. 00

B

85.73

5.49

1.75

7.03

100. 00

C

84.19

. 5.82

1,42

8.57.

100. 00

D

82.92

6.06

1.27

9.75

100. 00

E

82.20

5.45

 1.60

1.0. 75

100. 00

F

81.87

5.85

1.36

10.92

100. 00

The reciprocal variation of carbon and oxygen, the latter rising as 

the former falls, is here very well shown.

Even in a single mine the composition of the coal may vary within 

fairly wide limits. For example, F. Fischer * gives 24 comparable 

analyses of coal from the Unser Fritz mine, district of Arnsberg, 

Westphalia. From the table, in which the analyses are reduced to 

an ash and sulphur free standard, I select the following examples, 

which show the maximum and minimum proportion of each constituent. In the last column I give the average of the entire series: 

Analyses of coal from Unscr Fritz mine.

C...... ......................

H......... ...................

N..............:.. .............

0.... ........................

A

85.33

5.20

1.49

7.98

100. 00

B

85.06

4.66

1.35

8.93

100. 00

C

84.28

4.85

1.87

9.00

100. 00

D

82. 34

4.94

1.18

11. 54

100. 00

E

80.69

4.94

1.29

1.3. 08

100.00

F

83.81

4.98

1.47

9.74

100. 00

Other variations, due to the peculiar character of certain coaly 

material, are illustrated by the following analyses:

Analyses of fossil plants and cannel coal.

A. Average of six analyses of fossil plants, from the coal beds of Comentry, France, by S. Meunier, in 

Fremy's Encyclopedic chimique, vol. 2 (Compltoent, pt. 1), p. 152. The plants were perfectly preserved 

as to structure, but entirely transformed into coal. The genera Calamodendron, Cordaites, Lepidodendron, 

Psaronius, Ptychopteris, and Megaphyton are represented in this average. The variations between them 

are small.

B. Analysis of Wigan cannel, by F. Vaux, Jour. Chem. Soc., vol. 1,1840, p. 320.

C. Analysis of Tyncside cannel, by H. Taylor, Edinburgh New Philos. Jour., vol. 50,1851, p. 145. All 

three analyses are here recalculated to the ash-free basis.

c......................................... :...........

H.....................................................

N......................................................

o... ...........:......................................

A

82.45

4.75

.43

12.37

100. 00

B

83. 58

5.77

2.21

8.44

100. 00

C

87.89

6.53

2.08

3.50

100. 00

1 Zeitschr. angow. Chemie, 1894, p. 605. See also his Chomische Technologic der Brcnnstoffc, vol. 1, pp. 

518-520. -....! , . . . :. ..:
760 DATA OF GEOCHEMISTRY.

The suggestive feature of the foregoing trio is in the proportion of 

nitrogen. The fossil plants contain very little nitrogen; the cannels 

are abnormally Kigh. The inference is that plant remains have contributed but a small part of the nitrogen contained in coal, and that 

the main supply has come from other sources. The most obvious 

source is animal matter, and this was probably the source of the nitrogen in cannel. Newberry'1 long ago pointed out that fish remains 

are abundant in cannel coal, and he argues that the beds were laid 

down under water. Vegetable matter formed a carbonaceous paste, 

in which the fish remains became embedded and which consolidated 

to produce cannel coal.

For comparison with other varieties of coal, the subjoined averages 

will be useful. Moisture, sulphur, and ash are excluded from the 

table, except when otherwise specified.

Average analyses of bituminous coal.

A. Average of 20 analyses of bituminous coals from Pennsylvania, Maryland, Virginia, and West Virginia. Combined from data given in the reports of the fuel-testing plant of the United States Geological 

Survey.

B. Average of 40 analyses of bituminous coals from Ohio, Indiana, Illinois, Iowa, and Missouri. Also 

from the above-named reports.

C. Average of 15 analyses of Scotch coals, by W. D. Anderson and J. Roberts, Jour. Soc. Chem. Ind., 

vol. 17,1898, p. 1013. Sulphur is included in the figure for oxygen.

D. Average of 18 coals from Newcastle, 28 from Lancashire, and 7 from Derbyshire, England. Recalculated from averages cited by Fischer, in Chemische Technologic der BrennstoGe, vol. 1, p. 512.

c..... ........................................

H. ..........................................

N. ........................................... o.............................................

A

87.52

5.20

1.61

5.67

100. 00

B

82.91

5.70

1.49

Q QO

100. 00

c

83.65

5.48

1.86

Q 01

100. 00

D

84.19

5.58

1.41

8.82

100. 00

The peculiar chemical differences between the bituminous coals 

and lignite were described in the preceding section of this chapter. 

Many coals, which are apparently bituminous, and in fact are bituminous so far as technical uses are concerned, are really lignitic; at 

least so far as can be judged from their origin. Their true character 

must be determined by researches like those of Fremy and Donath, 

but refined methods of investigation are yet to be devised.

1 Am. Jour. Sci., 2d ser., vol. 23,1854, p. 212. J. Rote (Geol. Mag., 1866, p. 208) has also called attention 

to the fish remains in Lancashire cannel. B. Renault (Bull. Soc. ind. min., 3d ser., vol. 14, p. 138) regards 

cannel as formed from the spores of cryptogams. No algse are found in it, or very few. See also E. C. 

Jefirey, Proc. Am. Acad. Arts and Sci., vol. 46,1910, p. 273.
COAL. 761

ANTHRACITE.

In anthracite the transformation of vegetable matter into carbon 

approaches its limit. On one side of this class of coals we find the 

variety known as Semianthracite; on the other they approximate to 

graphite. The technical analyses of anthracite show a large proportion of fixed carbon, with relatively little volatizable matter a 

relation which appears in the following table:

Proximate analyses of anthracite.

A. Semianthracite, Coal Hill, Arkansas. From report of the coal-testing plant, Prof. Paper U. S. Ceol. 

Survey No. 48,190G, p. 202.

B. Anthracite culm, Scranton, Pennsylvania. Idem, p. 245.

C. Lykens Valley, Pennsylvania.

D. Schuylkill coal, Pennsylvania.

E. Cameroncoal, Pennsylvania. Analyses C, D, and E, by A. S. McCreath, Kept. Second Geol. Survey, 

Pennsylvania, vol. MM. This volume contains many other proximate analyses of coals. See also C. A. 

Ashburner, Trans. Am. Inst. Mm. Eng., vol. 14,1875-76, p. 70fi, for a tabulated classification of Pennsylvania anthracites. A large number of proximate analyses are there cited. For analyses of Colorado 

anthracites, see W. P. Headden, Proc. Colorado Sci. Soc., vol. 8,1907, p. 257.

Volatile. ...........'...................

Sulphur. ............................

Ash.................................

A

] 28

12.82

73.69

12.21

100. 00

B

2.08

7.27

74.32

16. 33

100. 00

C

2.27

8.83

78.83

.68

9.39

100. 00

:D

2.98

3.38

87.13

.66

5.85

100. 00

E

1.82

6.18

86.75

.75

4.50

100.00

Ultimate analyses of anthracites are much less numerous than for 

the other varieties of coal. The subjoined table, however, is enough 

for present purposes. Ash, sulphur, and moisture are excluded.

Ultimate analyses of anthracite.

A. Semianthracite. Arkansas; the same as A in the preceding table.

B. Welsh anthracite, analysis by F. Vaux, Jour. Chem. Soc., vol. 1,1848, p. 324.

C. From Scranton, Pennsylvania. Coal B of the preceding table.

D. From Mauch Chunk, Pennsylvania. Analysis by J. Percy, Quart. Jour. Oeol. Soc., vol. 1, 1845, 

p. 204.

E. From Province of Hunan, China. Analysis by F. Haeussermann and W. Naschold, Zeitschr. angew. 

Gnomic, 1894, p. 263. This paper contains twenty-eight analyses of Chinese coals, most of them anthracitic.

F. From the Bajewka, Ural. Analysis by Alexejeff, cited by Bertelsmann in an important memoir 

upon the nitrogen of coal, in Ahren's Sammlung chemischer und chemisch-technischer Vortriige, vol. 9, 

p. 339. A valuable table of coal analyses Is there given.

G. Average of sixteen analyses of anthracite, compiled from various sources.

C............... ......

H. ..................

N....................

0.....................

A

91.47

4.25

1.64

2.64

100. 00

B

92.73

3.37

.85

3.05

100. 00

C

93. 90

3.22

LOO

1.88

100. 00

r>

94. 63

2.73

1.36

1.28

100. 00

E

94.68

9 ?Q

.76

2.27

100. 00

F

97. 46

.61

.35

1.58

100. 00

G

93.50

2 81

Q7

9 79

100. 00
762 - DATA OF GEOCHEMISTRY.

Anthracite, however, is not .the extreme end of the coal series. 

There are pre-Carboniferous coals, which are found only in small 

quantities, arid which approach still more closely to pure carbon. 

The following substances belong in this class, with the possible exception of the first example. The crude analyses are given first.

Analyses of anthraxolite, schungite, and graphitoid.

A. Anthraxolite. near Kingston, Canada. Analysis by W. H. Ellis, Chem. News, vol. 76,1897, p. 186. 

Found in Lower Silurian limestone.

B. Anthraxolite, near Sudbury, Canada. Analysis .by. Ellis, loc. cit. Found in tho Cambrian. Ellis 

gives partial analyses of anthraxolites from three other localities. See also A. P. Coleman, Sixth Ann. 

Kept. Qntario Bur. Mines, 1897. 

C. Schungite, from Schunga, near Lake Onega, Russia. Mean of six analyses, reduced to anhydrous 

form, by A. Inostranzeff, Neues Jahrb., 1880, Band 1, p. 97; see also the same journal for 1886, Band 1, p. 92. 

Found in the Huronian.

D. Graphitoid, from the mica schist and phyllito of the Erzgebirge. Analysis by A. Sauer, Zeitschr. 

Deutsch. geol. Gesell., vol. 37,1885, p. 441.

C.. ......................:...-................

H......... .................................... N............:... .............................

s........... :..................................

o....... ......................................

HiO.. ......... ................................

Ash...........................................

'}

A

90.25

4.16

.52

.66

3.69

.72

100. 00

B

94.92

.52

1.04

.31

1.69

1.52

100. 00

C

98.11

.43

.43

1. 09

100. 06

D

24. 855

.06

L 01

73. 854

99. 779

Rejecting ash, water, and sulphur, these analyses assume the following form, comparable with the analyses of other coaly substances:

Recalculated analyses of anthraxolite, schungite, and graphitoid.

C..... ........................................

H. ...... .......................................

N.. ............................................

0....... ...................:..................

A

91.53

4 99

.53

3.72

100. 00

B

96.69

.53

1.05

1.73

100. 00

C

99.12

44

44

100.00'

D

99.76

94

100. 00

These minerals, and many anthracites also, might be properly 

described as metamorphic coals. They can not, however, even in the 

extreme cases, be termed graphitic, for they consist mainly of amorphous carbon. Graphite is a crystalline mineral, and upon treatment with, powerful oxidizing agents it can be transformed into a 

substance known as graphitic acid,1 CnH405 . The amorphous carbons do not yield this derivative, and Inostranzeff failed to obtain it 

from schungite. The approach to .graphite, therefore, is empirical

1 See B. C. Brodie, Liebi'g's Annalcn, vol. 114,1800, p. 0.
COAL. 763

only, and not constitutional-^-a conclusion which needs to be checked 

by a study of many other so-called "graphitic coals." That term 

may be applicable in some cases, but they are yet to be established.

THE VARIATIONS OF COAL.

For comparison of all the fuels, starting with wood and ending 

with anthracite, the subjoined table has been compiled from the 

data given in the preceding pages. In the case of wood the figure 

for nitrogen is the mean of the determinations by Chevandier, Gottlieb, aud Hawes.

Average composition of fuels.

Wood ........................................

Peat. ........................................

Bituminous coal . . . ...........................

C

49.65

55.44

72.95

84.24

93.50

11

6.23

6.28

5.24

5.55

2.81

N

0.92

1.72

1.31

1.52

.97

0

43.20

35.56

20.50

8.69

2.72

This table may be restated in a different form, so as to show the 

.proportion.of the other elements to 100 parts of carbon. It then 

appears as follows:

Comparative proportions of constituents of fuels.

Wood ........................................

Peat. ..........................................

Anthracite. ....................................

c

100

100

100

100

100

Jt

12.5

11. 3

7.2

6.6

3.0

N

1.8

3. 1

1.8

1.8

1.3

o

87.0

64.1

28.1

10.3

2.9

A steady decrease in hydrogen and oxygen thus becomes apparent. 

The data for nitrogen, however, are less conclusive, because of the 

uncertainty in the analyses of wood. If Hawes's average for the 

acrogen plants, 1.59 per cent of nitrogen, be taken, then its ratio 

becomes 3.1, identical with the figure for peat, and a definite decrease 

follows. New analyses of wood, with references especially to its 

nitrogen content, are much to be desired.

A closer scrutiny of the foregoing table reveals still another fact, 

namely, that the proportional decrease in oxygen is greater than in 

the case of hydrogen. In cellulose, C6H10O5 , these two elements exist 

in exactly the proportions required to form water. In wood the 

hydrogen is slightly in excess of that ratio (1:8), and the excess 

steadily increases until in anthracite it is proportionally very large. 

In wood the ratio is nearly 1:7; in anthracite, roughly, 1:1.
764 DATA OF GEOCHEMISTRY.

This progressive variation in the ultimate composition of the 

coals implies a corresponding variation in their proximate character, 

a class of changes to which attention has already been called. Even 

the crudest analyses are conclusive in regard to one form of variation. Peat, ignited in a covered crucible, yields much volatile matter 

and relatively little fixed carbon. In lignite the fixed carbon is 

higher, but commonly less than the volatile products. Bituminous 

coal is progressively richer in fixed carbon, while in anthracite the 

volatile portion has become exceedingly small. This particular 

variability is so characteristic that the ratio between fixed carbon 

and volatile matter has been adopted by some authorities as a basis 

for the classification of coals.1 Such a method of classification has 

the merit of convenience, for it requires only proximate analyses, 

which are numerous and easily made, although it must be admitted 

that their accuracy is often questionable. Moreover, the nature of 

the volatile matter varies in different kinds of coal, a part of it being 

combustible, and a part consisting of water and other noncombustible products formed during, the process of burning. In fact, 

the volatile matter is exceedingly complex, as is shown by a study of 

the substances formed when coal is distilled for the production of 

illuminating gas. The gas itself may contain hydrocarbons, freehydrogen, both oxides of carbon, nitrogen, and compounds of sulphur. Ammoniacal water solutions are also produced, together with 

coal tar; and in the latter a number of complex hydrocarbons are 

found, and also oxidized bodies such as phenol. In 20 analyses of 

coal gas, P. F. Frankland 2 found the following range of variations 

in the percentages of the principal constituents:

Variations in composition of coal gas.

C02 ................................................... Oto 2.73

02 ..................................J.......1.......... Oto 1.00

N2 .................................................... 2.07 to 10.84

H2 ..................................................... 33.24 to 53.79

CO................................................... 2.46 to 7.14

CH4 ................................................... 36.55 to 42.93

The other products of distillation, obviously must have been 

equally variable. The destructive distillation of wood yields substances quite unlike those derived from coal; methyl alcohol, acetone, 

and acetic acid being conspicuous among them.3

On account of this distinction between the combustible and noncombustible portions of the distillates from coal, S. W. Parr 4 has 

proposed a technical classification of these fuels which differs esseni See, for example, P. Frazer, Trans. Am. Inst. Min. Eng., vol. 6,1877-78, p. 430, and C. A. Ashburner, 

dem, vol. 14,1885-86, p. 706. . .

8 Jour. Soc. Chem. Ind., vol. 3,1884, p. 273. - 

3 A good article on the distillation of wood is in Watts's Dictionary of applied chemistry, vol. 3,1893, p. 

1026. The subject can not be discussed at length here.

« Bull. No. 3, Illinois Geol. Survey, 1906. Also Jour. Am. Chem. Soc., vol. 28,1906, p. 1425.
COAL. 765

tially from the system above mentioned. His scheme is based upon 

the ratio between the total carbon and the carbon of the volatile 

matter, which latter is largely but not wholly combustible. He also 

takes into account the percentage of "inert volatile" matter, which 

seems to vary in a manner characteristic of the different groups of 

coals. M. R. Campbell,1 on the other hand, has argued in favor of 

the ratio C:H, with which he has classified the analyses made at the 

fuel-testing plant. These classifications are chiefly of technological 

significance, and then? discussion falls outside the range of this work. 

The most important variations in coal, however, are those which 

were outlined under lignite. Passing from peat to anthracite there 

is a progressive diminution in the proportion of humus substances 

and also in the solubility of the coals in various reagents. The 

necessary details to illustrate these variations have already been 

given and need no further repetition here.

THE GASES IN COAL.

Both peat and coal, the latter in all its varieties, contain occluded 

or inclosed gases, often in large amount. In coal mines they sometimes escape in formidable volume, forming the so-called choke damp 

and fire damp of mining parlance. The choke damp consists of 

carbon dioxide or nitrogen or both together; the fire damp is principally methane.

The development of these gases can be traced back to the earliest 

stages of coal formation, when marsh gas was produced, along with 

carbon dioxide, in the process of vegetable decay. The evolution of 

methane from swamps was mentioned in the preceding chapter, with 

reference to its existence in petroleum and as natural gas. Its emanation from peat is another example of the same phenomenon, and 

is mentioned now for the reason that it was quantitatively studied 

by Websky.2 In a single analysis of gas extracted from peat he 

obtained the following percentages:

C0a ........................................................... 2.97

CH4 ........................................................... 43.36

Na ............................................................ 53. 67

. 100.00

The nitrogen from this gas is presumably a residue from the ground 

air, the oxygen of the latter having been consumed, partly to form 

carbon .dioxide and partly water.

The gases occluded by lignite, so far .as our information now goes, 

are of quite a different character. As analyzed by J. W. Thomas,3 

who obtained his material by heating lignite in vacuo to 50°, 100°,

1 Prof. Paper U. S. Geol. Survey No. 48,1906, pp. 156-173. See also P. Fraser, Bull. Am. Inst. Min. Eng., 

March, 1906; L. P. Breckenridge, Bull. U. S. Geol. Survey No. 325, 1907, p. 68.

2 Jour, prakt. Chemie, vol. 92,1864, p. 76.

3 Jour. Chem. Soc., vol. 32,1877, p. 146. Soealso Zitowitsch, Jour, prakt. Chem. 2d sen, vol. 6, 1873, 

p. 79, on gases from Bohemian lignites.
DATA OF GEOCHEMISTRY.

and 200°, successively, they consist principally of carbon dioxide, with 

subordinate carbon monoxide and nitrogen, and insignificant proportions of oxygen and hydrocarbons. The following examples are sufficient to show the generaljiature of his analyses:

Analyses of gases from lignite.

A. Gas from Bohemian lignite, extracted at 100°.

B. Gas from Bovey Heathfield lignite at 50°; 100 grams of coal gave 50.1 cubic centimeters of gas.

C. Gas from the same coal at 109°, 59.9 cubic centimeters.

D. Steam coal. 147.4 cubic centimeters gas. ' 

E. Gas evolved from sample Don heating to 200". , .

C02 ..... ................ .............

CO.. ................................

CH4 .. ................................

Olefiues. ..............................

C3H8 .... ..............................

Oo........... ......................... N;. ..................................

'

A

96.41

1.20

Traces.

.32

2.17

alOO. 10

13

87.25

3.59

94

8.92

100. 00

C'

89.53

5.11

. qo

5.03

100. 00

D 

96.05

3.20

.33

.42

100. 00

E

86.30

7.41

O 9.4.

2.08

.53

04.

100. 00

a The error in summation is probably clue to an unidentifiable misprint in the original.

Marsh gas, it will be seen, only appears in the product of heating 

lignite to 200° after decomposition had begun. In these lignites, at 

least, marsh gas is not normally occluded, but it would be rash to say 

that all other lignites follow the same rule. It is desirable that many 

more lignites should be examined in order to see whether or not they 

exhibit the same peculiarity. The samples studied by Thomas may 

possibly be exceptional.

In another investigation Thomas * examined the gases extracted in 

vacuo at 100° from cannel and jet. The analyses are subjoined, 

with a statement of the volume of gas yielded by 100 grams of each

sample.

Ayalyses of gases from cannel coal and jet. 

A. Wigancanncl. 421.3 cubic centimeters gas. 

B. Wigancanncl. 350.G cubic centimeters gas. 

C. Scotch cannel, Wilsontown. 1G.8 cubic centimeters gas. 

D. Scotchcanriel, Lcsmahag'o. 55.7 cubic centimeters gas. 

E. Cannel shale, Lasswade, near Edinburgh. 55.7 cubic centimeters gas. 

F. Whitbyjet. 30.2 cubic centimeters gas.

CO...... ..................... CH;........... ...............

C TT

r TT

.

A

G. 44

80.69

4. .75

8. 12

100.00

B

9.05

77.19

7.80

5.96

100.00

c

' 53.94

. 46. 06

100.00

D

84.55

.9i

M cCA

100.00

E

68.75

9 fi7

28.58

100.00

F

10.93

Rfi on

2 17

100. 00

Jour. Chcm. Soc., vol. 30, 1876, p. 144.
COAL.

The variations here are most remarkable. Methane predominates 

in. the gases from two cannels, carbon dioxide and nitrogen in the 

other three. In jet the proportion of butane is extraordinary, especially for the reason that jet is essentially a fossil wood, or in other 

words, a lignite.

The gases occluded by bituminous coal have been studied by several 

chemists. E. von Meyer * investigated a number of German coals, 

and also a series from the north of England. Several coals from the 

Newcastle region were studied by P. P. Bedson 2 and W. McConnell.3 

For Welsh coals there are data by J. W. Thomas.4 In Thomas's 

memoir both bituminous coals and anthracite are included, and from 

it I select the following analyses. The gases were extracted at 100° 

in vacuo, and in volumes which are referred to the uniform standard 

of 100 grams of coal.

Analyses of gases from bituminous and anthracite coal.

A. Bituminous coal. 55.9 cubic centimeters gas. 

B. Bituminous coal. 39.7 cubic centimeters gas. 

C. Bituminous coal. 55.1 cubic centimeters gas. 

D. Steam coal. 147.4 cubic centimeters gas.

E. Steam coal. 194.8 cubic centimeters gas.

F. Anthracite. G00.fi cubic centimeters gas.

G. Anthracite. 555.5 cubic centimeters gas.

rn OU^.........-.........

02 ..... ..............

N

A

36.. 42

.80

62.78

100. 00

B

9.43

31.98

2.25

56.34

100. 00

c

"5.44

63.76

1.05

29.75

100. 00

D

18.90

67.47

1.02

12.61

100. 00

E

5 04

87:30

.33

7.33

100. 00

F

14.72

84.18

1.10

100. 00

0

2.62

93.13

4.25

100. 00

The gases obtained by Von Meyer from Saxon and Westphalian 

coals were similarly variable in composition. In some of them ethane 

was reported up to 23 per cent; and also hydrocarbons, in small 

amount, of undetermined character. By weight the gases form only 

a fraction, usually a small fraction of 1 per cent of any coal.

The variability thus shown may easily be misinterpreted. The 

coals emit gases even in the mines, and the laboratory samples, therefore, do not represent the true character of the material under ground. 

Something is lost in transit from the mine to the laboratory, and its 

amount is conditional upon the texture of the coal. A hard, compact 

anthracite retains much of its gaseous charge; a porous coal, on the 

other hand, will lose much. So we see that the bituminous coals contain, as a rule, less gas hi the laboratory than the anthracites, although 

the bituminous mines are the most seriously affected by fire damp.

1 Jour, prakt. Chemie, 2d scr., vol. 5,1872, pp. 144, 407; vol. 0,1873,'p. 389. Data reproduced in Percy's 

Metallurgy, vol. 1,1875, p. 283.

2 Trans. North of England Inst. Min. Mech. Eng., vol. 37, p. 245. 

B Jour. Soc. Chem. Ind., vol. 13, 1894, p. 25. 

1 Jour. Chem. Soc., vol. ?S, 187G, p. 793.
768 DATA OF GEOCHEMISTRY.

In the coal beds themselves the bituminous coals are richest in 

gaseous occlusions. McConnell, in the memoir previously cited, 

also points out that in the Newcastle region the older and deeper coals 

contain the most methane, while in the younger seams carbon dioxide 

may predominate even to the exclusion of combustible gases. In his 

investigation of the Welsh coals, Thomas analyzed 14 samples of gases 

emitted from crevices or "blowers" in the mines, and found that they 

contained from 47.37 to 97.65 per cent of methane, with over 94 

per cent in all but two of them. Other earlier analyses of colliery 

gases have told essentially the same story.1 Methane is the principal 

gas of coal beds.

ARTIFICIAL COALS.

Various attempts have been made to prepare artificial coals in the 

hope of gaining some information upon the genesis of the natural 

products. Two lines of research are represented in these efforts, but 

neither has yet led to any final conclusions.

In the first class of experiments it was sought to produce coals by 

pressure. W. Spring 2 subjected peat to a pressure of 6,000 atmospheres, and transformed it into a hard, black, brilliant solid which 

was outwardly undistinguishable from coal. On the other hand, R. 

Zeiller,3 working with pressures of 2,000 to 6,000 kilograms to the 

square centimeter, found that peat and also the "ulmic acid" from 

the paper coals of Russia were merely compacted without change 

of chemical character. They retained their solubility in ammonia 

and showed no evidence of a true transformation into coal. Some 

experiments by Gumbel,4 who subjected lignite to pressure as high 

as 20,000 atmospheres, showed that even under such conditions no 

serious changes were produced and that the vegetable structure was 

in great measure preserved.

In the second class of experiments heat is used as the transforming 

agent. In the ordinary process of charcoal burning wood is heated 

out of free access of air, decomposition ensues, volatile matter is 

expelled, and a form of amorphous carbon finally remains in the 

kiln. Violette, 5 who has studied this process with great care, found 

that when wood was heated nearly to 400° in a sealed tube, 78.5 per 

cent of it remained as a solid residue which had all the appearance

1 See G.Bischof, Edinburgh New Philos. Jour., vol. 29,1840, p. 309; vol. 30,1840, p. 127; T. Graham, Mem. 

Chem. Soc., vol. 3, 1845, p. 7; Lyon Playfair, Mem. Geol. Survey Great Britain, vol. 1, 1846, p. 460. A 

recent paper on the gases in coal is by F. G. Trobridge, Jour. Soc. Chem. Ind., vol. 25,1906, p. 1129. See 

also the analyses of explosive gases from American coals by R. T. Chamberlin, in Bull. U. S. Geol. 

Survey No. 383, 1909. In them methane is the important constituent. On the other hand, gases from 

Silcsian coal analyzed by J. Meyer (Jour, prakt. Chem., 2d ser., vol. 90,1914, p. 141) contained principally 

carbon dioxide (choke damp), with some oxygen and nitrogen, and methane occasionally. Recent woik 

on gases in coal by C. H. Porter and F. K. Ovitz is published in Tech. Paper U. S. Bur. Mines No. 2,1911.

a Bull. Acad. roy. sci. Belgique, vol. 49,1880, p. 367.

s Bull. Soc. g<§ol. France, 3d ser., vol. 12,1884, p. 680.

4 Sitzungsb. Math.-phys. Classe, K. bayer. Akad. Wiss. Mflnchen, vol. 13, 1883, p. 141.

e Annaleschim. phys., 3d ser., vol. 32,1851, p. 304.
COAL. 769

of a fatty coal. In this case the volatile substances exerted a great 

pressure upon the contents of the tube, and a product very different 

from ordinary charcoal was formed. By heating wood under conditions which permitted the volatile matter to escape, he obtained 

a series of charcoals which varied in composition according to the 

temperature at which they were prepared. The experiments were 

conducted at temperatures ranging from 150° to the melting point 

of platinum; and his analyses of the products thus formed, 28 in 

all, show progressive changes, analogous to the changes observed in 

the passage from wood to anthracite. The charcoals, however, are 

not identical with coal, but differ from it both texturally and 

chemically. A finished charcoal is really the analogue of coke, being 

in fact the coke of wood; but in its preparation it is possible to trace, 

step by step, the breaking down of the original ligneous fiber. For 

that reason it is most desirable that the chemistry of charcoal burning 

should be studied much more in detail than it has been hitherto.

Violette's experiments with wood in sealed tubes were not the first 

of their kind. Early in the nineteenth century Sir James Hall 

obtained an artificial coal by heating wood in a closed cylinder of 

iron, and in 1850 or 1851 C. Cagniard-Latour l performed essentially 

the same experiment in tubes of glass. These earlier experiments, 

however, were merely qualitative, for the products obtained were not 

analyzed.

In 1879 Fremy 2 published an interesting series of observations, 

based upon experiments with carbohydrates other than cellulose, and 

upon the so-called "ulmic acid" from two sources. One example of 

ulmic acid was extracted from peat; the other was prepared from a 

constituent of woody tissue to which Fremy gave the name vasculose. 

The substances were all heated in sealed glass tubes to temperatures 

which seem to have been near 300° and yielded residues which 

behaved in all respects like coal. When heated to redness, they 

gaVe off water, gas, and tar and left behind a remainder of coke. 

These artificial coals had the following composition:

Composition of artificial coals.

Coal from sugar. .......................................

c

66.84

68.48

78.78

76.06

78.78

II

4.78

4.68

5.00

4.99

5.31

0

28.43

26.84

16.22

18.95

1 Q 9ft

The similarity of these products to natural coals, especially in the 

last three examples, is evident.

> Compt. Rend., vol. 32, 1851, p. 295. 2 Idem, vol. 88,1S79, p. 1048. 

11.3750° 19 Bull. 695 49
770 DATA OF GEOCHEMISTRY.

Still more recent experiments of this order are those of S. Stein.1 

He heated wood with water in sealed tubes, but at different temperatures, and partially analyzed the coaly substances thus obtained. 

His results are briefly as follows:

Experiments to obtain coaly products from wood.

Temperate e.

245

250

255

265

275

280

290

Time of 

heating.

Hours.

9

6

6

5

6

5

5

C

Per cent.

64.3

69.2

70.3

72.8

74.0

77.6

81.3

H

Per cent.

5.4

5.1

5.2

4.7

4,5

4.1

3.8

Here we have a series of products ranging in composition from a 

substance near peat to one more closely resembling coal. Only, it 

must be observed, the hydrogen toward the end of the series is lower 

than in coals showing the same percentage of carbon. The parallelism between the artificial and the natural substances is therefore not 

quite complete. The natural inference from this conclusion is that 

agencies other than heat and pressure have taken part in the carbonization of vegetable matter, and these may have been microbian 

in character. The function of heat is to decompose the organic complexes; that of pressure is to retard the change and to prevent the 

.escape of the volatile products; the combined effect must vary with 

variations in the intensity of the two agencies. If an exact adjustment of heat and pressure could be arranged, it is possible that a 

true artificial coal might be prepared, but this is mere supposition.

From one point of view the experiments with sealed tubes appear 

to be irrelevant. The change of woody fiber to peat or lignite is 

initiated at low temperatures and under nearly atmospheric pressure 

conditions quite unlike those which either Violette or Stein adopted. 

As the rotted material becomes buried the pressure upon it increases, 

but, except where igneous intrusions have operated, there is nothing 

to show that especially high temperatures have been at work. The 

element of time, however, must be considered. The natural processes 

are carried on slowly; and it may be that the laboratory methods 

merely accelerate them. So far, then, the experiments are pertinent 

but inconclusive. They certainly do not cover all the ground. All 

that can be said is that moderate temperatures and pressures, operating for a long time, may produce results resembling those which 

are brought about rapidly in the laboratory.

1 Chem. Ccntralbl., 1901, pt. 2, p. 950. From a Hungarian original which I have not seen. F. Bergius 

(Jour. Soc. Chcm. Ind.., vol. 32, 1913, p. 402) heated cellulose with water under pressure at 340°, and obtained a product undistinguishable from coal.
COAL. 771

 In order to account for what we might call the anthragenetic 

process, various hypotheses have been framed. J. F. Hofmann,1 for 

example, has used the analogy offered by the spontaneous combustion of grain, flax, and hay, and suggested that something of the 

same sort may happen in the buried materials from which coal is 

formed. In that phenomena heat is generated by fermentation, 

and when actual inflammation is prevented by lack of air a partial 

carbonization may occur. In cases of this kind heat is generated 

locally and an imperfect combustion occurs. Hofmann's suggestions 

are interesting, but, so far as the formation of coal is concerned, the 

evidence in their favor is very incomplete.

How far micro-organisms are active in the formation of coal is 

doubtful. They abound in the stagnant waters of swamps, and 

certainly have much to do with the earlier stages of vegetable decay. 

They start the process, but at the same tune they generate antiseptic 

compounds which limit their activity. Peat, not far below the surface, is distinctly antiseptic and inimical to microbian life. Nevertheless, a number of authorities have argued strongly in favor of 

these organisms as principal agents in anthragenesis. B. Renault 2 

has found their remains in lignite and coal in significant abundance 

and variety.

THE CONSTITUTION OF COAL.

In the preceding pages, under other captions, I have cited a good 

deal of evidence relative to the substances found in coal or from 

which coal has been derived. Its vegetable origin is clear and needs 

no further discussion now; its present constitution is more difficult 

to determine.

The question of constitution presents itself under two aspects, the 

one structural the other chemical. On the one side microscopic evidence is available, and it is seen that coal contains vegetable remains, 

micro-organisms, resinoid bodies, and so on. In some coals spores or 

spore cells are abundant; 3 in others, as shown by Renault, remains of 

algae are found. The lignites are obviously derived from woody fiber, 

and, in short, in many cases the proximate origin of the coals is not 

difficult to determine. Their structure, microscopic, or macroscopic, 

tells a pretty clear story.

i Zeitschr. angeiv. Chemie, 1902, p. 821.

' Bull. Soc. ind. min., 3d ser., vol. 13,1899, p. 865; vol. 14,1900, p. 1. See also L. Lemiere, idem, 4th scr., 

vol. 4,1905, pp. 851, 1248, and vol. 6, 1908, p. 273. Also in Compt. rend. VIII Cong. ge"ol. intemat., 1900, 

p. f>02. LomiSre regards the soluble or diastatic ferments, derived from living vegetation, as also operative 

In the process of vegetable decay.

 3 See J. W. Dawson, Am. Jour. Sci., 3d ser., vol. 1, 1871, p. 256. E. Orton (idem,.vol. 24,1882, p. 171) 

states that spore cases are abundant in the "sub-Carboniferous" rocks of Ohio, and are also found in the 

Devonian. On the microscopic structure of the natural hydrocarbons, resins, and coals, see Fischer and 

Rust, Zeitschr. Kryst. Min., vol. 7, 1882, p. 209. The important memoirs by Bert-rand and Renault and 

by Jeffrey have already been referred to. See also White and Thicsscii's bulletin on the origin of coal, 

already cited, for a full summary of this subject, with many additional details.
772 DATA OF GEOCHEMISTRY.

On the chemical side the problems are much less simple. The 

proximate constituents of coal are most imperfectly known and the 

little knowledge we have is mainly qualitative. The necessary 

investigations are difficult, the methods are not well formulated, and 

the available data are scattered and fragmentary. To what extent 

free carbon exists in coals is still an open question. It is probably 

absent from lignite and abundant in the extreme anthracites; but 

its quantitative determination can not be effected by any known 

analytical process.

There are two distinct lines of attack upon the problem in question. First, by means of solvents, to extract certain constituents of 

coal and to identify them. Some of these constituents, which are 

commonly small in amount, can be dissolved by gasoline, ether, benzene, chloroform, alcohol, and other organic solvents. The extractive matter thus obtained is, unfortunately, not simple, but seems 

to contain a mixture of .substances whose nature is yet to be determined. By handling large quantities of material these bodies may be 

obtained in sufficient abundance for more complete investigation, 

and their separation into definite fractions is by no means hopeless.1 

The remarkable solvent action of pyridine upon some of the constituents of coal, as studied in recent years by several investigators,2 

also offers a promising line of attack upon the problems.

Alkaline solvents, such as caustic soda, caustic potash, and ammonia, dissolve, as we have already seen, humic substances from peat 

and brown coal, but not from the older carbons. These substances 

are indefinite, but in time their nature may be determined, and their 

correlation with the ligneous carbohydrates ought then to become 

possible. If, however, as is supposed, some coals are derived from 

gelatinous algae, the problem becomes more complex. The chemical 

constitution of those forms of vegetation is still very obscure. Up 

to the present time the mistake has been made, by chemists engaged 

in the study of coal, of assuming that the celluloses are the chief 

starting points an assumption which is not unqualifiedly true. Carbons of animal origin also require attention. Much preliminary work 

of this kind remains to be done.

i On this subject see the authorities already cited. Also P. Siepmann, Preuss. Zeitschr. Berg-, Hiitten- u. 

Salinenwesen, vol. 39, 1891, p. 27. F. Muck (Die Chemie der Steinkohle, Leipzig, 1891) gives a good 

summary of earlier investigations by Dondorff, Reinseh, etc. An interesting memoir by W. C. Anderson 

(Proc. Philos. Soc. Glasgow, vol. 29,1897, p. 72) also describes a number of important experiments.

a T. Baker, Trans. Inst. Min. Eng., vol. 20,1900, p. 159; and P. P. Bedson, Jour. Soc. Chera. Ind., vol. 27, 

1908, p. 147. See also E. Donath, Chem. Zeitung, vol. 32,1908, p. 1271; L. Vignon, Compt. Rend., vol. 158, 

1914, p. 1421; A. Wahl, idem, vol. 154, p. 1095. J. C. W. Frazer and E. G. Hoffman (Tech. Paper U. S. Bur. 

Mines No. 5,1912) have studied the extracts obtained from coal with phenol. A. Pictet and L. Ramseyer 

(Ber. Deutsch. Chem. Gesell., vol. 44,1911, p. 2486), by extraction with hot benzene obtained hexhydrofluorene, Cw Hi6 . In a later paper (Compt. Rend., vol. 163,1916, p. 358), Pictet, Ramseyer, and O. Kaiser 

report the extraction of other hydrocarbons up to CaoHw- By solution with carbon disulphide E. Donath 

and 0. Manouschek (Chem. Zeitung, 1908, p. 1271) extracted anthracene and chrysene from a German 

coking coal.
COAL. 773

The direct separation of its constituents from coal is, however, 

possible only to a very limited extent. Hence the second line of 

attack, the conversion of these bodies into recognizable derivatives, 

is also essential. Not only do we need more experiments along the 

line developed by Donath, whose distinction between the lignites and 

the true coals has already been discussed, but much more needs to be 

done in the study of oxidation products, chlorine derivatives, etc. 

For example, in addition to the researches upon the nitrocompounds 

derivable from coal and the chlorination experiments reported to the 

British Association, there are investigations like that conducted by 

L. Schinnerer and T. Morawsky.1 These chemists fused lignite with 

caustic soda, and by distillation of the melt obtained pyrocatechin, 

which is a benzene derivative. The true coals, so far as examined, 

did not yield this compound, which seems to have been produced 

from the resinoid constituents of the lignite. By experiments of this 

order the compounds existing in coal can be correlated with other 

substances of known constitution, and some at least of the problems 

which confront us may be solved. The future chemistry of coal will 

be shaped by a study of its immediate constitution and not by the 

multiplication of empirical analyses.3

1 Ber. Deut9ch. chcm. Gcscll., vol. 5,1872, p. 185.

a Theniouographcmtheconstitutionofcoalby M. C. Stopcsancl R. V. Wheeler, published by the Departin eut of Scientific and Industrial Research, London, 1918, is an important summary cf the subject, with an 

excellent bibliograply. Other recent investigations are by Arthur H. Clark and R. V. Wheeler, Jour. 

Chcm. Soc.,vol. 103,1913,p. 170<1; M. J. Burgess and Wheeler, idem, vol. 97, 1910,p. 1917, vol. 99,1911, p. 

649, vol. 105,1914, p. 131; D. T. Jones and Wheeler, idem, vol. 105,1914, p. 2562; vol. 107,1915, p. 1318; and 

vol. 109,1916, p. 707.

INDEX.

A.

Aar, River, analysis of water................ 97

Abbot, C. G., and Fowle, F. E., carbon dioxide and climate................. 50,144

Abbot, H. L. See Humphreys and Abbott. 

Abort Lake, analysis of water............. 159,172

Abich, H., analyses of spinel................ 338

Abilena well, analysis....................... 183

Abilcne artesian well, analysis............... 178

Abraham, H., asphalt....................... 721

Absorption, of substances by soils............ 496

Acanthitc................................... 654

Acetylene............................. 724,731,732

Acetylene series............................. 724

Achcson, E. G., artificial graphite........... 322

d'Achiardi, A., origin of berates.............. 240

d'Achiardi, G., minerals in marble........... 626

origin of boratcs......................... 240

Ackroyd, W., atmospheric transport of salt 54,

147,148,165 

relative abundance of elements.........' 28

Acmito.................................... 375,376

Actinium.................................... 308

Actinolitc................................. 379,380

Actinolite-magnetite schist................ 379,613

Adamellosc-................................. 448

Adamite.................................... 678

Adams, B. F.,cited......................... 47

Adams, F. D., allanite and epidote.......... 404

alteration of pyroxene................... 378

amphibolite........................... 595,627

analyses by............................. 88,181

compression of granite................... 34

mclilito rocks............................ 396

moamouthite............................ 441

primary calcite.......................... 414

Adams, F. D., and Dick, W. J., phosphate

roclr............................. 519

Adams, F. D., and Harrington, B. J., hastingsitc.......................... 382

Adams, F. D., and Lawson, A. C., scapolito

diorite......................... 401,600

Adams, G. L, concentration of petroleum..... 745

gypsum............................... 226,578

native sulphur.......................... 579

salt deposits............................. 224

zinc deposits............................ 682

Adams, L. H. See Johnston and Adams. 

Adirondackiasc.............................. 402

Adler, River, analysis of water.............. 99

Adobe soil..-.--....................:...... 505,506

Adriatic Sea................................. 121

Adschi-Darja. See Karaboghaz.

Aegtri te..................................... 375

Aenigmatite.................................. 383

Agate....................................... 352

Aguilarite................................. 657,696

Page. 

Aguilera, .T. G., stibnite..................... C96

Aichino, G., bauxite......................... 492

Aigner, A., polyfcalite....................... 222

Aikinite..................................... C67

Air, dissolved, composition of................ 51

See also Atmosphere. 

Aisinmann, , origin of petroleum........ 738

Aitkin, J., atmospheric dust................. 54

Akermanite................................. 391

Akerose....................... 435,437,440,450,451

Alabama River, analysis of water............ 74,75

Alaska, rivers of............................. 87

Alaskite.-................................... 430

Alaskose.................................. 431,433

Albanose ................................... 442

Albert, R. See Malkomcsius and Albert. 

Albertitc.............................. 727,728,730

Albite................................. 287,359,362

Albite mosaic............................... 597

Albrecht, R., optical activity of petroleum.... 743

Alcyonaria................................ 522,565

Aldebaranium............................... 21

Alexandrolite............................... 703

Alexejeff, W.,dopplerite.................... 752

Alferric minerals............................ 422

Algte, as limestone makers......... 548,553,564,565

as source of bitumens.................. 741,742

in relation to coal........................ 748

magnesium carbonate in................ 505

siliceous................................. 511

Algodonitc......'............................ 6G3

Alipite...................................... 702

Alkali,insoils............................. 231-237

Allanite............................... 402,404,719

Allegheny River, analysis of water........... 79

Allemontite................................. 63-t

Alien, E. T., aluminum hydroxide........... 493

analyses by............................ 226,327

native iron.............................. 327

pentathionatcs.......................... 266

synthesis of quartz....................... 354

See also Davy and Alien; Posnjak, Alien, 

and Merwin; Zies, Alien, and 

Mcrwin. 

Alien, E. T., and Clement, J. K., water in

amphiboles...................... 383

Alien, E. T., and Crenshaw, J. L., greenockite, .

pyrite, and marcasite........... 329

sulphides of mercury.................. 672,673

sulphides of zinc......................... 679

Alien, E. T., Johnston, J., and Crenshaw,

J. L., sulphides of iron.......... 329

Alien, E. T., and White, W. P., fusion oflimo

silicate......................... .286,294

synthesis of diopsidc--.................. 374

wollastonite........................... 873,024

775
776 I5TDEX.

Page. 

Alien, E. T., Wright, F. E., and Clement,

J. K., forsteritc. -........................ 388

magnesium silicate............... 286,372,381

Alien, I. C., and Burrell, G. A., natural gas.. 72 

Alien, 0. D., analyses by.. 153,157,198,229,230,232 

Ailing, H. L., graphite...................... 322

Alloclasite................................... 699

AUopalladium............................... 707

AUophane............................. 412,495,614

Alma well, analysis cited.................... 181

Almandite.................................. 396

Aloisi, P., spinel rocks...................... 338

Altai, Lake, analysis of water............. 167,171

saline deposit......................... 228,229

Altaite....................................... 683

Altmiihl, River, analysis of water........... 101

Aluminum, distribution..................... 13

in sea water............................. 120

Alum shale.................................. 543

Alums.................................... 254,265

Alunite..................................... 254

Alunogen................................... 254

Alway, F. J., loess.......................... 505

Alway,F.J.,andGortner,R.A., water analysis 160 

Amalgam................................. 648,653

Amazon River, analyses of water............ 91

Amber...................................... 749

Amblygonite................................ 692

Amesite...................................... 392

Ammiolite.................................. 670

Ammonia, in rainfall........................ 51,52

in sea water............................. 119

Ammonium fluoride, in volcanic gases....... 255

Amphiboles............................... 379-384

Amphibolite.............................. 378,595

Amsoldingen, Lac........................... 95

Ana River, analysis of water................ 159

Analcite............................... 383-366,376

Analcite rocks....................:.:.. 444,445,366

Anamorphism, zone of.................... 587-589

Anatase................................... 346,347

Andalusite........................ 405-407,614-615

Andalusite rocks...................... 406,614,615

Anderlini, F. See Nasiui, R. 

Andersen, O. See Bowen and Andersen. 

Anderson, W., cited....................... 158,210

Anderson, W. C., experiments on coal....... 772

Anderson, W. C., and Roberts, J., coal.... 757,7GO

Anderson, W. S., solubility of calcium carbonate.. ........................ 126

See also Irvine and Anderson. 

Andesine.................................. 282,359

Andesite.............................. 448-450,482

Andesner, H., fusion of gabbroid magma.. 300,418 

And-orite.................................. 658,684

Andose.................... 446,450,451,452,456,457

Andouard, A., phosphate rock.............. 517

Andradite................................... 397

Andro", G., cited............................. 475

Andre"e, K., bibliography of oceanic sedimentation ........................... 510

eelestite................................. 582

fluorite in sediments..................... 585

Andrew, A. R., gold in country rock........ 647

phosphate rock.......................... 526

Andrews, E. C., magmatic assimilation...... 304

Page. 

Andrews, T., native iron.................... 324

Androscoggin River, analysis of water....... 72

Androussof, N., reduction of sulphates by

bacteria....................... 146,511

Anemousite................................. 359

Anger, F. A., shale.......................... 545

Angernsee, analysis of water.................. 103

Anglesite.............................. 684,680. G87

Angstrom, K. J., carbon dioxide and climate. 49 

Anhydrite......................... 218,221,242,250

Animikite................................... 654

Ankerite.................................. 562,572

Annabergite................................. 701

Annecy, Lake of, analysis of water.......... 9-1

Annelids.................................. 522,565

Anorthite...................... 287,288,359-362,604

Anorthcclase................................ 359

Anorthosite................................. 457

Ansdell, G. Sec Dewar and Ansdell.

Ansel, H., iron ores.......................... 577

Anthon, E. F., precipitation of sulphides.... C43

Anthophyllite......................... 379,380,387

Anthracite................................ 761-763

Anthraxolite................................. 762

Antimony, distribution...................... 14

ores of................................. 694-697

Ants, geological work of..................... 480

d'Aoust, V., oolite........................... 548

Apatite................................ 349,350,519

Aphrosiderite................................ 392

Aphthitalite................................ 218

Apjohn, J., water of the Dead Sea............ 165

Aplite..................................... 430-433

Apophyllite............................... 320,412

Aragonite...................... 138,413,549-553,562

Aral, Sea of, analysis of water......... 162-163,171

Arapahite................................... 463

Arapahose................................... 463

Arctic Ocean, analyses of water.............. 122

Arctowski, H., synthesis of hematite........ 342

Ardennite................................... 714

Arfvedsonite............................... 383-384

Argall, P., distribution of nickel............. 698

Argentite............:.................... 654,655

Argon, distribution.......................... 14,42

in fumaroles........................... 250,262

in spring waters.......................... 176

Argyrodite................................... 658

Arias, Rio de, analysis of water.............. 92

Arkansas Hot Springs, analysis of water..... 190

Arkansas River, analysis of water............ 67,82

Arkansose................................... 442

Arkite....................................... 442

Arnold, R., and Anderson, R., alteration of

shale............................. 612

Aromatic hydrocarbons..................... 725

Arrhenius, S. A., carbon dioxide and climate.49,143 

nature of earth's interior................. 58

volcanic explosions.................... 280,281

Arsandaux, H., analysis by................ 489,518

bauxite.................................. 491

laterite................................... 489

Arsern, C. W., graphite...................... 323

Arsenic, distribution........................ 14

in sea water.............................. 119

ores of................................. 694-697
INDEX. 777

Page. 

Arsenolite................................... 697

Arsenomiargyrito............................ C59

Arsenopyritc............................... 694,627

Artis, B., analysis of rain water.............. 53

Arva-Polhora, analysis of water.............. 180

Arve River, analysis of water................ 94

Arznmi, A., cassiterite as a furnace product. 348,690

cuprite.................................. 6G8

hematite................................. 342

Asbestos..................................... 379

Asbolite............................... 532,701,702

Aschan, 0., humus in natural waters........ 106

iron ores................................. .529

waters of Finland........................ 103

Asch.irite.................................. 220,245

Ashburncr, C. A.,anthracite................. 761

classification of coals..................... 764

Ashlcy, G. H., antimony deposits............ 696

formation of peat...................... 750,753

See also Blatchley and Asliley. 

Ashley, II. E., colloids in clay............... 497

Ashlcy, J. M.,cited.......................... 93

Askwith, W. R., antimony mines........... C97

Aspasiolitc.................................. 402

Asphalt............................... 721,727-730

Assiniboine River, analysis of water......... 88

Aston, E., analysis by....................... 609

Astrakanitc................................. 218

Atacamite................................... 668

Atherton, T. \V. T., gold sulphide........... 647

Atlantic Ocean, analyses of water............ 122

Atlin, spring near, analysis.................. 186

Atmosphere, composition of................. 42-48

mass of.................................. 22

the primitive............................ 55-58

Atomic weights............................. 13

Atopitc...................................... 697

Atrck River, analysis of water............... 163

Attcrbcrg, A., alteration of topaz............ 405

latcrito.................................. 489

Attwood, G., decomposition of diabase...... 483

Audoynaud, A., ammonia in sea water...... 119

Auorbach, F., cited......................... 197

Aucrbach, H. S., tungsten deposits.......... 706

Aug(5, , bauxite......................... 491

Augite ................................ 268,2S7,377

Austin, W. L., nickel ores................... 701

Autunito.................................... 714

Auvcrgnosc................... 451,452,450,457, G27

Avalitc...................................... 703

Awaruite.................................. 326,698

Awerkiew, N., solubility of gold............. 651

Azurite.................................... G61,669

B.

Babingtonite................................ 378

Babitsco, analysis of water.................. 103

Bacon, R. F., analyses cited................. 195

Bacteria, as agents in rock decomposition '.... 480

Bacterial precipitation of calcium carbonate. 146,547 

Bad Elstor, analysis of water from........... 188

Baddeckito.................................. 387

Baddcleyito................................. 718

Baclo, A. A., arsenic and vanadium in water. 92,712 

Biickstrom, IT., fusion of micas............ 391,443

on Sorot's principle...................... 303

synthesis of acmite...................... 370

Tage. 

Baer, W., analyses of wood.................. 747

Baerwakl, C., pscudoinorphs of carysocolla.. CCS 

Bacumlcr, , nickel in shale.............. 698

Baeumlerite................................. 220

Baikal, Lake, analysis of water.............. 103

Bailey, E. II. S., analyses by.......... 182,183,723

zinc in mine waters...................... 636

Bailey, E. H. S., and Case, E. C., analyses

by............................. 178,225

Bailey, E. II. S., and Franklin, E. C., water

analyses......................... £0

Bailey, E. II. S., and Porter, F. B., analysis

by............................... 178

Bailey, G. E., California borates............. 240

soda niter......°........................ 249

Bailey, R. K., analyses by.................. 153

Bain, II. F., fJuoritc......................... 585

lead and zinc deposits................... 682

Baker, A. L., bromine in bittern............ 227

systhesis of livingstonitc................. 673

Baker, H. B.,cited.......................... 50

Baker, T., extracts from coal................ 772

Bakcrite..................................... 243

Balatonsce, analysis of water................ 102

Balch, D. M., potassium chloride in alg».... 137

Baldacci, L., sulphur deposits............... 580

Baldauf, R., cryolite......................... 331

Balland, , cited......................... 67

Ballo, M., water analysis.................... 101

Ball<5, R., and Dittler, E., mineral syntheses. 376 

Ballston waters, analyses.................... 182

Baltic sea, analysis of water................. 122

Baltimoriaso................................. 459

Baltimoroso................................. 459

Bainbcrgcr, E., flchtclitc.................... 753

Bancroft, G. J., origin of oro bodies.......... 643

Bancroft, H., platinum in dikes............. 709

Bandose................................... 448,456

Bandrowsky, F. X., nitrogen in petroleum.. 726 

Baragwanath, W., platinum................ 711

Barber, W. B. See Nutter and Barber. 

Barbicr, P., and Prost, A., composition of

. feldspars........................ 359

Barbicrite................................... 359

Barbour, E. II., and Torrey, J., siliceous

oolite............................ 542

Barcenitc................................. 670,698

Barchatow bitter lake, analysis of water.... lf,S, 171

Baret, C. Sec Lacroix and Baret.

Barima River, analysis of water............. 90

Barite............................. 134,530,582-584

Barium, distribution........................ 14

in sea water.............................. 120

Barkcvikitc............................... 383,384

Barlow, A. E., nickel deposits............. 700,702

Barlow, W. E., solubility of silver halides... 660 

Barnard, H. E., analysis of water............ 72

Barnes, H. T. See Rutherford and Barncs. 

Barnitzkc, J. E., kaolinization............... 487

Barr, W. M., analyses by..... 76,77,78,79,80,82,83

Cove Creek acid water................... 194

Barrandite................................ 516,519

Barrell, J., magmatic assimilation........... 301

ago ol the earth.......................... 314

Barrois, C.,chloritoid rocks.................. 616

Barschall, H. See Van't Hoff and Barschall. 

Bartow, E., waters of Illinois................ 64
778 INDEX.

Pago. 

Barus, C., electricity in ore bodies........... 664

sedimentation........................... 502

thermo-couple........................... 285

water glass.................... 291,292,589,041

Barus, C., and Iddings, J. P., electric conductivity of molten rocks........ 293

Barysilite................................... 689

Basalt................................. 444,452-455

fusibility.............................. 290,293

Basanitc..................................... 438

Bascli.E. E.,syngcniteandpolyhalitc...... 222

Basicrocks................................ 461-464

Baskcrville, C., analyses by................ 339,703

vanadium in peat....................... 712

See also Corse and Baskervillc. 

Bassett, H., cited............................ 152

Bossier, R. S., siliciflcation of fossils......... 557

Bastin, E.S.,colloidal gold.................. 653

diagnostic criteria of mctamorphic rocks. 627 

origin of graphite........................ 323

pegmatite............................. 297,430

pyrrhotitic peridotite.................. 330,461

silver ores of Cobalt, Ontario............. 650

secondary enrichment................... 643

Bastin, E. S., and Hill J. M., magmatic sulphides........................... 330

See aho Palmer and Bastin. 

Bastite...................................... 373

Batcmr.n, A. M., Sudbury ores.............. 700

Baubigny, H., synthesis of sphalerite........ 676

Bauer, H., and Vogcl, H., cited.............. 97

Bauer, K., fusion of mineral mixtures....... 300

Bauer, M., laterite........................... 4S9

ncphelitein schists...................... 368

Bauerman, H., and Foster, C. Le Neve,

celestitc......................... 581

Baughman,W. F. SceSkinnerand Baughman. 

Baumann, A., and Gully, E., humus acids.. 479 

Baumert, M., composition of dissolved air.. 51,472 

Baur, E., hydrothermal syntheses........... 589

synthesis of quartz and tridymite........ 353

synthesis of quartz and feldspars......... 362

Bauxite................................... 488-496

Baxter, C. P., and Grovcr, F. L., atomic

weight of lead .................. 314

Bayldonite.................................. 689

Bayley, W. S., actinolite-magnetite schist... 379 

graywacke............................... 538

iron ores.............................. 341,575

talcose schist............................ 625

Beam, W., water analyses................... 105

Bear River, analysis of water................ 154

Beard, E. E. See Watsonand Beard. 

Beaumont, E. dc, distribution of the elements 13 

volcanic emanations..................... 256

Beauvallct, P., vanadium in clay............ 712

Beaverite.................................... 689

Bechamp, A., equilibrium in mineral waters. 197 

hydrogen sulphide and calcium carbonate.............................. 580

Bechi, E., origin ofboratcs................ 239,240

distribution of vanadium................ 712

Bechilite.................................... 238

Beck, R., cassiterite in granite............... 348

diamond................................ 320

Pago. 

Beck, R., gases from obsidian............... 278

magnetite............................... 341

native copper............................ 662

native silver............................. 653

nickel deposits........................... 700

ore deposits............................. 629

primary gold............................ 328

tin ores.................................. 692

Beck, R., and Fircks, W. von, copper ores.. 665 

stibnitc.................................. 696

Beckc, F., amphibolite...................... 595

changes of volume in metamorphism.... 591

eclogite.................................. 602

graphic symbols......................... 470

hornblende pscudomorphs............. 381,387

saussurite gabbro........................ 598

scapolitc rock............................ 600

specific gravity of igneous rocks.......... 416

See also St5p and Bcckc. 

Becker, A., fusion of hornblende............. 381

fusion of limestone....................... 555

Becker, G. F., ago of minerals............. 311,313

age of ocean........................... 146,150

arsenic and antimony in sinter..... 201,695,600

borates.................................. 233

Borax Lake............................. 238

constitution of amphibolcs and pyroxenes 382 

cpidote from chlorite.................... 600

eutectics as solvents..................... 293

eutectic classification of rocks............ 419

formation of native sulphur.............. 578

fractional crystallization in magmas...... 305

geological significance of wollastonitc... 373,624 

glaucophanerocks..................... 334,594

gold in sinter.......................... 201,050

heavy metals in granite.................. 631

magmatic differentiation................ 303

mercury ores.................. 670,673,674,675

minerals in sandstone................... 538

nature of magmatic solutions............ 293

oceanic chlorine......................... 139

origin of petroleum...................... 736

pore space in sandstone.................. 536

radioactivity.......................... 313,314

secondary enrichment................... 643

serpentine......................... 411,606,607

solvents of gold. ...................*...... 651

Steamboat Springs.... 192,201,631,650,675,696

viscosity of lava......................... 303

waters ofSulphur Bank.................. 192

Becker, G. F., and Melville, W. H., mercury

in sinter......................... 675

Becqucrcl, A. C., synthesis of dioptase....... 669

synthesis of lead ores.......... 683,685,686,688

Bccquerel, H., and Moissan, H., free fluorine

influorite....................... 331

Bedson, P. P., barium in water.............. 582

constitution of coal...................... 772

gases in coal............................. 767

paraffin in coal........................... 756

Beegerite.................................... 684

Beemerose................................... 440

Beerbachose...................:...:....... 451,456

Beilstein, F., and Wiegand, E., ozokerite.... 728

Beisk, Lake, analyses of water............. 167,171

saline deposits........................... 228
INDEX. 779

Page.

Bcistlc, C. P. See Frcar and Beistlc. 

Belchcrosc. ................................. 459

Beldongritc................................. 532

Bell, J. B., platiuiferous quartz.............. 710

Bell, J. M. See Cameron and Bell.

Bell, J. M., and Clarkc, E. do C., mercury in

sinter............................ 675

Bell, R., corrosion oflimcstonc.............. 550

nickel deposits.......................... 699

Bcllucci, G., chlorides in rain................ 53

BSlohoubek, A., water analysis.............. 99

> Bcloncsitc................................... 704

Bcmmelcn, J. M. van, absorbent power of

hydrogcls........................ 497

absorption of potassium by clays........ 136

aluminum hydroxides................... 494

decomposition of rocks.................. 487

hydroxides of iron..................... 528,529

latcritc.................................. 489

tropical soils............................. 494

zcolitic silicates in soil................... 206

Bemmolcn, J. M. van, Hoitsema, C., and

Klobbie, E. A., bog iron ore... 528,530 

Bcmmelcn, J. M. van, and Klobbie, E. A.,

iron hydroxides................. 529

Benedicks, C., sericitic rocks................. 590

Bcnodict, F. G., atmospheric oxygen........ 43

Bcnnctt, J. See Haworth and Bonnctt.

Bcnson, W. W., serpentine.................. 607

Bcntz, G., baritc............................ 584

Benzene series............................... 725

Bcraunite................................... 516

Bcresovite................................... 687

Berg, L., Sea of Aral......................... 163

Bcrgeat, A., boric acid from Vulcano........ 238

nontronite............................... 486

occurrence of titanium minerals......... 347

volcanic sublimates...................... 265

Bergenose................................... 482

Bcrgius, F., artificial coal.................... 770

Berglund, E., bromine in sea water.......... 121

Bcrstriisser, , cited....................... 163

Bergt, -, analysis by ..................... 543

Bertels, G. A., origin of petroleum........... 739

Berthelot, M., gases in native iron........... 282

origin of petroleum.................... 732,734

synthetic hydrocarbons.................. 731

Berthier, , synthesis of olivine........... 385

Berthierine.................................. 577

Berthierite.................................. 094

Bertrand, C. E., and Kenault, B., origin of

bitumen......................... 741

Bertrandite.................................. 410

Benverth, F., constitution of hornblende.... 382

Beryl........................................ 410

gases from............................. 270,312

Beryllium. See Glucinum.

Beryllonite.................................. 410

Berzelianite................................. 663

Best, A. See Coates and Best.

Beudantite.................................. 689

Beyer, S. W., clays.......................... 503

Beyerinck, M. W., cited..................... 110

Beyrichite................................... 698

Beyschlag, F., cobalt ores................... 698

See also Monke and Beyschlag.

Page.

Beyschlag, Krusch, and Vogt, ore deposits.. 629 

Bickell, C., analysis by...................... 202

Biddle, H. C., precipitation of copper........ 662

Biddle, H. J., nickel ores.................... 702

Bieberite.................................... 701

Big Blue River, analysis of water...........? 81

Big Lake, analysis of water.................. 160

Biggs, J. W. H. See Clowes, F.

Bigstone Lake, analysis of water............. 77

Biljo Lake, analysis of water............. 167,173

Biltz, W., and Marcus, E., borates at Stassfurt.............................. 245

copper in Stassfurt salts................. 218

nitrates and ammonia in Stassfurt salts.. 218 

See also Marcus and Biltz. 

Binder, G. A., solubility of cinnabar......... 673

solubility of sulphides................ 633,634

Bindheiinite................................. 689

Bingham, H. See Jamieson and Bingham. 

Binney, E. W., and Talbot, J. H., petroleum

in peat.......................... 742

Biotite.................................... 386-392

Biquard, R. See Moareu, C.

Bird, M., analysis by........................ 178

Birge, E. A., and Juday, C., analysis cited.. 77 

Bisbeeite.................................... 669

Bischof, G., analyses by......... 101,102,168,500

cements in sandstone.................... 536

dolomitization........................... 566

gases in coal............................ 768

origin of salt beds........................ 215

reduction of silver sulphide.............. 654

solvents of gold.......................... 650

sphalerite in sinter....................... 677

zinc carbonate........................... 679

Bischoflte.........".......................... 219

Bismite..................................... 697

Bismuth, distribution....................... 14

ores of................................. 691-697

Bismuthinite................................ 695

Bisrnutite................................... 697

Bismutosmaltite............................. 698

BismutosplKcrite............................ C97

Bistincau, brine, analysis of................. 178

Bitter Lake, analysis of water............ 167,171

Bitterns......................... 170,172, 214, 227

Bitumen.................................... 721

Bituminous coal...................... 75S-760, 763

Bizio, G., litlu'um in sea water............... 119

Black Lake (California), analysis of water. 158,172 

Black Lake (Rournania)..................... 169

Black Sea, analysis of water..'............... 122

Blackwelder, E., phosphate rock............ 519

Blackwell, G. G., bauxite................... 492

Blairmorite.................................. 444

Blake, J. F., glaucophane schist............. 594

Blake, W. P., bauxite....................... 492

gilsoniteand wurtzilite.................. 728

primary gold............................ 646

Terlingua mines......................... 671

tin deposits........................... 690,693

tungsten ores............................ 706

zinc deposits............................. 682

Blanc, G. A., radiothorium.................. 309

Blanckenhorn, M. See Semper and Blauckenhorn.
780 INDEX.

Blatchley, W. S., clays...................... 503

petroleum............................... 743

Blatchley, W. S., and Ashley, G. H., marl.. 549 

Bleeck, A. W. G.Jadeite.................... 370

Bleicher, , iron ores...................... 577

Blende..................................... 675-678

Blbedite................................... 218, 250

Blount, B. See Chad wick and Blount. 

Bluejoint Lake, analyses of water........ 160,172

Blue Lick Springs, analysis of water......... 179

Blum, W., Great Salt Lake.................. 153

Blum and Leddin, Carlsbad spriidelstein.... 199

B obierrc, composition of rainfall............. 53

Bobierrite................................... 517

Bode, G., cited.............................. 70

Bodenbender, G., wolframite................ 706

Bodlander, G., analysis by.................. 575

melilitein Portland cement.............. 394

sedimentation........................... 502

Bodtker, clay................................ 510

Bb'ggild, O., cryolite......................... 331

Boekc, H. E., borates in potash salts........ 245

bromine in potash salts.................. 218

carnallite and tachhydrite............... 219

lusion of carbonates...................... 555

garnet................................... 397

graphic representation of Stassfurt salts.. 219 

iron in potash salts...................... 220

rinneitc.................................. 220

Bottcher, W. See Kramer and Bottcher. 

Bocttker, E., Norwegian pyrite.............. 331

Boghead mineral............................ 748

Bog iron ore............................... 528-530

Boleite...................................... 686

Bolley, P., origin of borates.................. 240

Bolton, H. C., solubility of minerals in organic acids....................... 479

Bolton, W. von, recrystallization of diamond

tantalum................................ 718

Boltonlte.................................... 386

Boltwood, B.B., age of minerals........... 313,314

radioactivity of hot springs.............. 210

Bone, W. A., and Coward, H. F., union of

carbon and hydrogen............ 732

Bone, W. A., and Jordan, D. S., synthetic

hydrocarbons.................... 732

Bonncville, Lake........................... 152-155

Bonney, G. T., glaucophane eclogite......... 594

matrix of diamond....................... 320

serpentine............................. 605,609

Bonyssy. See Hcnriet and Bonyssy.

Booth, J. C., and Muckle, A., Dead Sea...... 165

Boracite................................... 220,245

Borates................................ 220,237-248

Borax..................................... 237-248

Borax Lake, analysis of water............. 158,172

borax from.............................. 238

Bordas, F. See Girard, C.

Borgstrom, L. H., hackmannitc............. 369

scapolite................................. 400

Boric acid................................. 238,265

Borickite.................................... 516

Borne, G. von dem, radioactivity of granite.. 309 

Bornitc.................... 330,663,664,665,666,750

Borntragcr, H., analyses of peat............. 752

Borocalcite.................................. 238

Borodowsky, W., orpimcnt and realgar...... 695

Boron, distribution.......................... 14

in sea water............................. 119

nitride................................. 239,240

sulphide................................. 240

Boronatrocalcite............................. 243

Bosworth, T. 0., Scottish sands............. 499

Bothamley, C. n., analysis by............... 180

Boudouard, O., melting point of silica..... 273,287

Boulangeritc................................. 684

Bouquet, J., analyses by..................... 186

spring deposits........................ 199,200

Bouquet dela Grye, A., cited................ 124

Bourcart, E., Swiss lakes.................... 95

B ourgeois, L., cassiteritc in scoria............ C90

formation of perolskitc................... 344

lusion of garnet.......................... 397

synthesis ol crocoitc...................... CS8

of hydrocerusite..................... 685

of iolitc.............................. 401

oi meionite.......................... 400

of melilite and gchlonitc........... 395,396

of opal............................... 352

of smithsonitc....................... 679

of spcssartite......................... 398

of titanitc............................ 345

of wollastonite....................... 373

Bourgeois, L., and Traube, EL, synthesis of

dolomite......................... 561

Bourgoin and Chastaiug, analysis by........ 192

Bournonite................................ C67,668

Boussingault, J. B., analyses by........... 194,227

carbon dioxide irom volcanoes........... 47

Dead Sea................................ 164

jet....................................... 754

manganese nodules...................... 131

nitrate earth............................. 248

origin of acid in volcanic waters.......... 195

Boussingaultitc............................ 238,248

Boutan, E., diamond........................ 322

Boutron-Charlard, A. F., and Henry, O.,

Dead Sea........................ 165

Boutwell, J. M., carnotitc.................... 716

Bowen,N. L.,carnegieite.................... 359

differentiation in silicate melts........... 306

fusion of cnstatite........................ 300

magnetic differentiation................. 306

melting points of silicates............... 286

ncphclite................................ 367

Bowen, N. L., and Andersen, 0., forsteritc.372,386 

magnesium metasilicatc................. 372

melting points of minerals............. 286,360

Bownockcr, J. A.,petroleum................ 743

Bow River, analysis of water................ 88

Brachiopods........................... 521,522,565

Brackebuschite.............................. 689

Brackett, R. N., analyses by........... 81,482,543

Brackett, R. N., and Williams, J. F., rcctorite............................ 614

Braconnier, , analysis by................ 183

Bradley, F. II., unakite..................... 601

Bradley, W. M. See Foote and Bradley. 

Braunlich, F. See Donath and Braunlich. 

Bragard. See Fernandez and Bragard. 

Brand, A., artificial breithauptite............ 699

Brandcnbourg, R., water analysis............ 94
INDEX. 781

raje. 

Branner, J. C., antimony deposits........... 093

bacterial decomposition ol rocks......... 483

bauxite.................................. 493

clays.................................... 503

diamond................................. 321

geological work of ants................... 480

magnesia in coral reef.................... 567

novaculitc............................... 540

phosphorite.............................. 524

sandstone reels.......................... 530

tallow clays.............................. 081

thermal disintegration of rocks........... 472

zinc deposits............................. C82

Branner, J. C., and Newsom, J. P., phosphorite............................... 524

Bransky, O. E. Sec Gilpin and Bransky. 

Branson, 0. E., origin of salt beds........... 215

Brauner, B.,goldtelluride................... 649

synthesis ol hessite...................... 657

Braunitc.................................... 531

Brauns, E., alteration of olivinc............. 387

conchitc................................. 550

gold in a cement........................ 650

graphite and molybdenite in basalt.... 323,330

origin ofsalito........................... 375

silvialite................................. 400

theory of micas.......................... 392

websbyite............................... 411

Bravo, .T. J., vanadium ores................. 713

Brazier, J. S., analyses by................. 508,509

Brazos River, analyses of water............. S3

Brcckenridge, L. P., classification of coals... 765 

Breesc, C. M. See Failyer and Breese. 

Brcitenlohner, J. J., on the Elbe............. 98

Breithauptite............................. 698,699

Brcunneritc............................... 413,572

Brewer, W. H., sedimentation............... 502

Brewsterite................................. 412

Briegleb, H., synthesis of apatite............ 349

Briner, E., and Wroczynski, A., polymerization ofacetylene................. 732

Brinsmadc, R. B., cerusitc deposit.......... 685

Brochantite............................... 668,669

Brock, R. W., gold in igneous rocks....... 328,646

platinum................................ 711

Broderick, T. M., secondary enrichment..;.. 672 

Brodie, B.C., graphitic acid................ 762

synthesis of methane.................... 269

Brogger, W. C., alteration of acmite to analcite............................. 376

alteration of analcite..................... 366

of arf vcdsonite and barkevikite...... 384

ofelseolitc........................... 365

classification of igneous rocks............ 421

composition of barkevikite.............. 383

formula of tenigmatitc................... 38-1

gibbsite and diaspore.................... 493

magmatic differentiation............. 292,302

nephcline syenites..................... 368,441

nordcnskjoldine......................... C90

occurrences of fluorite................... 331

of zircon............................. 348

sprcustoin............................... 371

sulphides in pegmatite.................. 331

Brogger, W. C., and Biickstrom, H., the garnet group..................... 369,397

Page. 

Broggerite................................... 715

Brokaw, A. D., precipitation of gold......... 652

solubility of gold........................ 052

Bromine, distribution....................... 14

in bittern............................. 165,227

Bromly, A. H., tin deposits................. 692

Bromyrite.- -................................ COO

Brongniarditc............................. 658,68-1

Bronze, minerals formed on........... 663,665,668

Bronzite................................... 371,373

Brookite.................................. 346-347

Brooks, A. H.,tin deposits.................. 693

Brooks, W. K., abundance of life in pecan... 145 

Brown, A. P., pyrite and marcasitc......... 330

Brown, B. E., water analyses.............. 83,154

Brown, C. R. See Judd and Brown.

Brown, F. C., geologic time... -.............. 315

Brown, L. See Meadows and Brown.

Brown, L. P., phosphorite.................. 523

Brown, T. C., oolite......................... 551

Brownc, D. H., nickel deposits.............. 700

Brucite........................... 411,562,572,607

Brugnatelli, L., titanolivine................. 385

Bruhns, W., synthesis of corundum......... 333

synthesis of hematite................... 342

of ilmenite......................... 343

of quartz and trid ymitc............. 353

Brumell, H. P. H., petroleum............... 743

Brun, A.,.deposition ofsulphur.............. 264

fusibility of basalt........................ 2SO

granite.................................. 430

melting points of minerals......... 286,287,288

metals in volcanic exhalations.......... 265

origin of petroleum...................... 735

synthesis of coriindum................... 332

of hydrocarbons..................... 732

of quartz and tridymite............. 354

of zoisitc............................. 402

volcanic gases......................... 276,277

volcanic hydrocarbons.................. 277

volcanism......................... 260,270,277

water in muscovite...................... 279

Brun, A., and Collet, L. W., volcanism...... 276

Brunlechner, A., formation of iron ores...... 575

Brunswick well, analysis................... 179

Brush, G. J., pyroxene in slag............... 374

Brush, G. J., and Dana, E. S., alteration of

spodumenc..................... 375

eucryptite............................. <3G9

Brushite.................................... 517

Bryozoa..................................... 565

Buchanan, D. G., analysis by............... £50

Buchanan, J., section of nitrate deposit...... 249

Buchanan, J. Y., density of sea water....... 124

manganese nodules...................... 131

marine mud............................. 510

oceanic carbonic acid.................... 142

Bucher, W. A., oolite....................... 551

Biichncr, E. H., radioactivity of rocks....... 309

Buchrucber, L., babingtonite in slags........ 378

Bucking, H., iolite.......................... 402

Bucklcy, E. R.,clays....................... 503

lead and zinc ores....................... 682

Bucklcy, E. R., and Buchlcr, H. A. zinc deposits ........................... 682

Buckman, H. 0., clays and kaolin........... 487
782 INDEX.

Pago. 

Buehler, H. A., and Gottschalk, V., analyses

of mine waters................. 636

Buehler, H. A. See also Bucklcy and

Buehler. 

Bujor, P.,cited.............................. 168

Buluktii-Kul, analysis of water............ 168,171

Bunscn, E. W., composition of dissolved

air........................... 43,51,471

fundamental magmas.................... 302

gases in rock salt........................ 269

magmatic solutions...................... 302

oxygen of the atmosphere............... 43

volcanic gases......................... 256-257

Bunscnite................................... 701

Burada, A., the Black Sea................... 121

Burchard, E. F., lignite..................... 756

Burgess, G. K. See Waidner and Burgess. 

Burgess, J. A., halide ores of silver........... 660

Burgess, M. J., and Wheeler, R. V., volatile

constituents of coal.............. 773

Burnett, J. B., barite concretions............ 583

Burrell, G. A., natural gas................... 72-3

See also Alien and Burrell. 

Burrell, G. A., and Oberfeld, G. G., analyses

of natural gas.................... 723

Burton, C. V., artificial diamond............ 319

Burton, R. C., laterite....................... 489

Busch, E. E., nicke! deposits................ 700

Buschraann, J. 0., von, Das Salz............ 225

Bushong, F. W., petroleum............... 725,743

Bushong, F. W., and Weith, A. J., analyses

by............................... 81,82

Busz, K., analysis by...................... 489,490

corundum............................... 334

Butler, B. S., epidote........................ 403

plumbojarosite.......................... 687

Butler, B. S., and Gale, H. S., alunite....... 254

Butler, F. H., kaolinization................. 487

Biitschli, 0., calcareous organisms......... 554,564

celestite in radiolarian................... 581

Butte, Montana, mine water................. 185

Buttgenbach, G., Argentine borates......... 244

Byasson, H., origin of petroleum............ 734

B yerlite..................................... 729

Byerly, J. H. See Mabery and Byerly.

Bygden, A., eutectics...................... 296,419

B yske-elf, analysis of water.................. 103

By townite................................... 359

C.

Caballero, G. de J., cobalt in Mexico......... 098

ranurite.............................."... 713

Cabrerite.................................... 701

Cache la Poudre Eiver, analyses of water.... 66

Cacoxenite... .c............................. 516

Cadell, H. M., cited on Stassfurt saltsl....... 216

Cadmium, distribution...................... 14

ores of................................. 675-687

Cady, H. P., and McFarland, D. F., composition of natural gas.............. 722

Cjcsium, distribution........................ 15

in sea water:............................' 119

Cagniard-Latour, artificial coal.............. 769

Cahaba River, analysis of water............. 74,75

Cailletet, L., hydrogen in iron............... 282

Calamine.................................... C78

Calaverite................................... 649

Page.

Calb, G. See Jannasch and Calb. 

Calcareous algae....................... 553,564,565

Calcareous sinter.......................... 198-199

Calcioferrite................................. 516

Calciovolborthite.......................... 713,717

Calcite................. 138,242,413,549-553,562,572

inclosing sand........................... 535

Calcium, distribution........................ 15

Calcium carbonate, circulation of............ 128

proportions on ocean floor............. 126-129

solubility of........................... 126-129

Calculation of rock and analyses........... 4C8,469

Calderon, C. S., Chaves, D. F., and Pulgar,

P. del, glauconite................ 512

Caledoni te................................... 687

Caliche.................................... 249,250

California geysers............................ 194

Californite................................... 399

Calker, F. J. P. van, pseudogaylussite....... 157

Callainite.................................... 516

Calomel..................................... 670

Calvin and Bain, zinc ores................... 680

Cameron, F. K., alkali in soils............... 237

water analyses........................... 154

Cameron, F. K., and Bell, J. M., solubilities............................ 224,473

Cameron, F. K., and Hurst, L. F., solubility

of calcium phosphate.......... 515,516

Cameron, F. K., and McCaughey, W. J., synthesis of apatite.................. 350

Cameron, F. K., and Seidell, A., solubility of

calcium phosphate............. 515,516

Campbell, H. D. SeeHowe, J. L.

Campbell, J. M.,laterite..................... 489

Campbell, M. E., borate deposits.. 240,241,242,243

classification of coals-.................... 765

Campbell, N. E., radioactivity.............. 308

Campbell,N. K., and Wood, A.,radioactivity. 311 

Campbell, W., and Knight, G. W., cobalt ores. 701

nickel deposits.......................... 700

Campbell, W. D., pseudomorph of gold...... 651

Campo, A. del, ammonium fluoride in volcanic gases....................... 256

rare metals in ores....................... 675

Camptonite.................................. 451

Camptonose....................... 451,452,456,457

Canada, mineral springs..................... 211

Canadase.................................... 457

Cancrinite................................. 369-371

Cancrinite syenite........................... 371

Canfleldite................................... C58

Cannelcoal............................ 759,760,766

Cape Fear Eivcr, analysis of water........... 74

Caracolite.................................... 686

Carbides, metallic......................... 275,731

Carbon, distribution......................... 15

Carbon dioxide in the atmosphere........... 46-50

Carbonates in sea water.................... 126-129

Carbonates, alkaline....................... 231J237

origin of............................... 231-237

Carbonic acid, oceanic....................... 141

Carbonyls, metallic.......................... 325

Carborundum............................... 322

Carles, P., barium and sulphates in natural

water.............................. J.99

fluorine in shells of mollusks............. 118

in spring water...................... 188
INDEX. 783

Page. 

Carlsbad Sprudel water, analysis............ 188

Carminito................................... 689

Carnallitc.................................... 219

Camcgicitc.................................. 359

Carnclley, T., on periodic law................ 38

solubility of copper...................... 651

Carnot, A., fluorine in phosphates......... 519,520

fluorine in sea water................... 118,520

galena................................... 683

inincrvito- -- -............................ 518

phosphate rock.......................... 515

syntheses of stibnite and bismuthinite. - - C95 

water analysis......................... 16S, 192

Carnotito.................................. 714,716

Caron, H. See Devillc and Caron.

Carpenter, W. L., oceanic carbonic acid. 145,552,553

Carromto.................................. 663,693

Carstone..................................... 539

Cary, L. R., alcyonaria as reef builders...... 568

Caryinito.................................... 689

Casares, J., fluorine in spring water.......... 188

Case, E.G. See Bailey and Case.

Case, W. H., zinc deposits.......:........... 682

Casoria, E., palmerite........................ 518

volcanic sublimates...................... 265

Caspar!, AV. A., glauconite................... 513

red clay.................................. 510

Caspian Sea........................... 162,163,171

Casscl brown................................. 757

Casscliaso. -.................................. 460

Casselosc.................................... 454

Cassiopeium................................. 21

Cassitcritc............................. 348,690-694

Castorina, G. T.,radioactivity oflava........ 309

Cataplciito................................... 718

Catharinet, J., copper ores ................ 665,666

gold in pegmatite........................ 646

sperrylite in pegmatite................... 711

Cathrein, A., alterations of garnet.......... 398,399

chloritoidrock......................... 391,616

cpidotization............................ 600

loucoxeno................................ 341

occurrence of chloritoid.................. 391

psoudomorphs after gehlenite............ 390

after scapolite........................ 401

saussurite. -.............................. 598

titanifcrous magnetite................... 343

Catlctt, C., analyses by.................... 556,648

See also Clarke and Catlctt. 

Caycux, L., chalk........................... 551

gaize.-................................... 540

glauconite............................. 512,514

glauconitic iron ore...................... 528

oolitic iron ores.......................... 578

phosphatic nodules...................... 132

soils..................................... 503

Cobollitc..................................... 396

Cocilosc...................................... 459

Cedar R iver, Iowa, analysis of water......... 78

Ccdarstrom, A., cited........................ 344

Coladonite............................. 512,513,514

Celestite........................... 218,242,581,582

Cellulose .............................. 746,747,703

Celsian...................................... 359

Cementation, belt of....................... 587,588

Cements in sandstone...................... 535,530

Page. 

Ccnteno, J., analyses by..................... 195

Cerargyrite................................ 242,660

Ccritc........................................ 719

Cerium, distribution......................... 15

sources of................................ 719

Cerusito............................... 684,685,686

Cervantite................................... 697

Ccs&ro, G., synthesis of crocoite and wulfenitc. 683 

Chabazite.................................... 412

Chabrie, , Algerian saltpeter............. 218

Chadwick, 0., and Blount, B., analysis by... 105 

Chalcanthite............................... 688,669

Chalcedony.................................. 352

Chalcocitc............................. 663,665,666

Chalcophanite............................... 673

Chalcophyllite............................... 603

Chalcopyrite............... 330,663,664,665, C66,750

Chalcostibito................................ 667

Chalk...................................... 546,551

Chalmers, R., peat........................... 753

Chalmersite.................................. 6S3

Chamberlin, R. T., borax lake of Ascotan.... 244

gases from coal........................... 7C8

gases from rocks........... 276,278,280,281,232

Chamberlin, T. C., carbon dioxide in atmosphere... ......................... 47

influence of oceanic carbonates on climate ........................... 48,144

loess......................... 505

planetesimal hypothesis............ 58,138,280

zinc ores............................... 680,682

Chambcrlin, T. C., and Salisbury, R. D.,

clays.......................... 502,505

volcanism............................... 280

volume of ground water................. 34

Chambers, A. A. See Dole and Chambers. 

Chamosite.................................. 392,577

Champex, Lac............................... 95

Champlain, Lake, analysis of water.......... 70

Champlainiase............................... 462

Chance, H. II., origin of iron ores............ 527

Chancourtois, E. do, metals in earth's interior 325 

water analysis........................... 166

Chandelon, J. T. P., cited.................... 91

Chandler, C. F., analyses by......... 70,72,181,182

Chaper, M., diamonds in pegmatite.......... 321

Chaplin Lake................................ 160

Charante, G. M. van, analysis of water....... 523

Charcoal .................................. 70S

Charcoal, fossil............................... 754

Charitschkoff, K., synthetic hydrocarbons... 732 

waters accompanying naphtha.......... 740

Charlton, A. G.,nickel ores................... 698

Charlton, H. W., analysis by................ 444

Chastaing, . SeeBourgoin and Chastaing. 

Chatard, T. M., analyses by.... 65,154,157,158,159,

232,233,377,459,460,539,544,556,575,618,703 

natural soda........................... 233,235

origin of corundum...................... 335

tallow clay............................... 681

Chateau, , Algerian phosphates........... 523

Chattahoochee River, analysis of water....... 74,75

Chautard, J., lateritization................... 489

Chautard, J., and Lemoine, P., lateritiaation. 489

Chaves, D. F. Sec Calderon, C. S., etc.

Chazal, P.E., phosphate rock................ 623
784 INDEX.

Page. 

Chehalis River, analysis of water............. 86

Ch&if River, analyses of water............... 67,68

Cheltenham waters, analysis............... 182,183

Ch<3u, A., sediment of the Nile............ 114,501

water of the Nile......................... 104

Chemical denudation...................... 110-117

Chenevixite...'.'.". ............................ 008

Cherrydale mineral water.................... 191

Chert...................................... 540-543

Chester, A. H., on waters of New Jersey....... 72

Chester, F. D., epidotization................. C01

Chevallier, A., cited.......................... 124

Chevandier, E., analyses of wood............ 747

Chewaucan River, analysis of water.......... 159

Chiastolitc schist............................. 017

Chicago drainage canal....................... 108

Chichen-Kanab, Lake, analysis of water...... 101

Chicmsee, analysis of water.................. 96

Chilenite........................!............ 054

China Sea, analysis of water.......... 1....... 122

Chippewa River, analysis of water........... 77

Chiviatite.................................... CS4

Chloanthite.................................. 098

Chlorides in rainfall.......................... 53,54

Chlorine, distribution........................ 15

in atmosphere............................ 53,54

in potable waters................... 53,108,109

in sea water, origin of.................. 137-139

in volcanic gases.....'.................... 250

Chlorites............................... 392-394,602

Chloritization.............................. 602,003

Chloritoid.......................... 388,391.015,016

Chloritoid-phyllitc........................... 017

Chlormanganokalito.......................... 265

Chlorophyll!to............................... .402

Chloropal.................................... 488

Chloropite................................... 603

Chlorothionite............................... 205

Chlorspodiosite.............................. 350

Cholcsterin.................................. 743

Chondrodrite................................ 006

Chotose...................................... 442

Christie, W. A. K., Cis-Indus salt beds....... 223

See also Holland and Christie.

analysis by.............................. 169

Christy, S. B., synthesis of cinnabar....... 071,072

Chromic iron ore. See Chromite.

Chromite.......................... 338,339,702-703

Chromi tite................................... 339

Chromium, distribution..................... 15

ores of................................. 702-704

Chrompicotitc............................... 339

Chrustschoff, K., artificial diamond......... 318

synthesis of hornblende.................. 380

of mica.............................. 390

of quartz and feldspar................ 362

of quartz and tridymite............ 353,354

of zircon............................. 349

Chrysocolla................................ 008,069

Chrysolite................................... 385

Chuard, E., alteration of bronze.............. 865

Church, A. H., silicification of coral....... 511,541

Cimarron River, analysis of water............ 82

Cimolite............................... 412,488,614

Cincinnati artesian well, analysis............ 179

Cinnabar.............. 070,671,672,673,674,075,750

Page. 

Ciplyte....................................... 520

Cirkel.F., graphite......;................... 323

City Creek, analysis of water.................. 154

Claesson, C., Dopplerite:.................... 752

Clapp.F. G., limestones...................... 556

Claraz, G. See Heusser and Claraz. 

Clark, Arthur II., and Wheeler, R. V., volatile constituents of coal.......... 773

Clark, Austin H., crinoids................... 564

Clark, G. F., cited........................... 93

Clark, J. D., colloidal sulphides.............. 645

See also Tolman and Clark. 

Clark, J. D., and Menaul, P." L., colloidal

sulphides....................... 645,657

Clark, T. E., fichtelite....................... 753

Clark, W. B., greensand..................... 513

Clarke, F. W., ago of ocean................ 147-151

alteration of iolite........................' 402

analyses by........................ 65,154,156,

179,188,460,556,649,702 

average abundance of minerals......... 362,415

average compost ion of igneous rocks.. 24-28 

brucite-serpentine..................... 411,607

chemical denudation.................... 59,114

clays.......;............................. 488

constitutional formulae................. C03-605

constitution of amphiboles............. 382,383

of pyroxenes... '. ..................... 379

cookeite................................. 387

cryptomorphite.......................... 245

evolution of the elements................. 12

formula ofcancrinite..................... 309

glauconite and greenalitc............... 513,576

isotopic lead............................. 314

melilite group............................ 395

molecular weight of silica................ 356

roscoelite................................ 387

silica niKllifo.......................... 107,511

solubility of minerals.................... 475

specific gravity of igneous rocks.......... 416

theory of chlorites....................... 392

total run-off of rivers..................... 59

zeolites.................................. 413

Clarke, F. W., and Catlett, C., nickel ore... 700,711 

Clarke, F. W., and Barton, N. H., iron mica.. 387 

Clarke, F. W., and Diller, J. S., alteration of

topaz.......................... 404,405

nickel silicate............................ 701

Clarke, F. W., and Salkover, B., analysis of

crustaceans...................... 522

Clarke, F.W., and Schneider, E. A., calcination of talc..................... 411

formation of spinel....................... 338

micas and vermiculites................ 382,393

Clarke, F. W., and Steiger, G., abundance of

heavy metals................... 28,632

ammonium analcite and leucite.......... 364

analyses of lobster shells................. 522

cadmium................................ 675

vesuvianite. .............................. 399

Clarke, F. W., and Wheeler, W. C., echinoderms, etc..... 521,523,564,565,568,633

Claude, G., composition of air................ 42,45

Claudetite................................... 697

Claus, C., phosphatic sandstone........... 520,537

Clausmann, P. Sec Gautier and Clausmann. 

Clausthalite.................................. 683
INDEX. 785

Page. 

Claypole, E. W., tin deposits.............. 693

Gays...................................... 502-504

dehydration of......................... 613-617

plasticity of.............................. 497

Clays, oceanic...................... 129,130,507-511

Clear Lake, analysis of hot spring near........ 192

Clement, J. K. See Alien, E. T.

Clements, J. M., iron ores.................. 341,575

Clemm, W., silication of limestones.......... 557

Clermont, P. de, and Frommel, J., solubility

of sulphides:..................... 633

Cleveite...................................... 715

Climate, influence of carbon dioxide on. 49-50,144 

Clinochlore................................... 392

Clinoclasite.................................. '668

Clinohedrite................................. 678

Clinozoisite.................................. 402

Clintonite.................................... 388

Clb'ez, S., hydrocarbons in iron............... 731

Clouet, J., synthesis of chromite............. 704

(/lough, C. T., and Pollard, W., occurrence

of olivine........................ 386

Clowes, F., baryticdeposits................. 582

barytic sandstones....................... 537

Cowes, F., and Biggs, J. W. H., solubility of

oxygen in sea water............. 139

Coal......;................................ 746-773

Coal oil..................................... 733

Coates, C. E., and Best, A., petroleum....... 725

Cobalt, distribution....:..................... 15

in ashes ofsea weeds..................... 120

ores of................................. 698-702

Cobaltite.................................... 698

Cochenhausen, E. von, water analysis....... 153

Codington, E. W., phosphate rock........... 524

Cohen, E., matrix of diamond............... 320

salt lake in Transvaal.................... 169

Cohen, E., and Raken, M., solubility of calcium carbonate.................. 127

Cohen, J. B., and Finn, C. P., oils from coal.. 756 

Cohn, F., travertine......................... 548

Cole, G. A. J., bauxite....................... 491

-Cole, G. A. J., and Little, 0. H., calcite and

aragonite in fossils............... 551

Coleman, A. P., anthraxolite................ 762

corundum-nepheline syenite............'. 334

heronite................................. 3G6

magmas and ores........................ 331

magmatic assimilation................... 304

nickel deposits.......................... 699

Colemanite............................ 240,242,243

Collet, L. W., oceanic deposits............ 129,513

phosphatic nodules...................... 132

See also Brim and Collet.

Collet, L. W., and Lee, G. W., glauconlte... ; 513 

Collier, A. J., tin deposits.................... 693

Collier, P., native platinum.................. 708

Collins, H. F., mercury ores................. 670

Collins, J. H., nickel deposits................ 700

tin ores.................................. 691

Collins, W. D., analyses of water............ 68,

70,72,73,74,75,76,77,78,79,80,82,83 

Colloids in clay........................ 494,497,502

CoHophanite............................... 517,519

Page.

Collot, L., distribution of barium and strontium. ............................ 582

Collyrite..................................... 614

Colomba, L., alteration of glaucophane....... 384

Colorado River (Argentina), analysis of water 92

Colorado River (Arizona), analysis of water.. 83

How of................................... 83

Colorado River (Texas), analysis of water... 83 

Coloradoite.................................. 670

Columbia River, analysis of water........... 85

Columbite................................. 693,718

Columbium, distribution..................... 15

sources................................ 717-718

Colvocoresses, G. M., cobalt ores............. 701

Comanducci, E., copper and cobalt in volcanic ash........................ 631.

Conacher, H. R. J., oil shale................. 749

Conchite..................................... 550

Condit, D. D., minerals in sand............. 499

Conichalcite................................. 668

Connarite.................................... 702

Connate waters.............................. 207

Conneautsville well, analysis................. 181

Consanguinity of rocks....................... 301

Contamination of river waters............. 108,109

Cook, E. H., cited........................... 48

Cook, G. H., clays...s....................... 503

green sand marl......................... 513

marl..................................... 548

native iron............................... 324

Cooke, H. C., secondary enrichment......... ,654

Cooke, J. P., vermiculites.................... 392

Cooke, W. T. See Mawson and Cooke. 

Cookeite..................................... 387

Cookose...................................... 457

Coolgardite.................................. 649

Coomara-Swaniu,, A. K., Ceylonese graphite. 322 

corundum............................... 334

minerals in limestone.................... 626

Cooper, A. S., origin of petroleum............ 741

Copal......................................... 749

Copiapo, Rio, analysis of water.............. 02

Copper, distribution......................... 16

in sea water.............................. 120

ores of................................. 660-670

Copper River, analysis of water.............. 87

Coppock, J. B., cited........................ 122

Coquand, H., antimony ores............... C96,697

bauxite.................................. 491

boratcs.................................. 240

itabirite................................. 012

Coquina................................... 553,556

Coral.............................. 546,554,556,565

siliciflcation of........................... 511

Coral rock................. 549,510,550,553,554,566

Cordieritc..................'................ 401,402

Cornet, F. L., phosphatic chalk.............. 523

Cornet, J. See Renard and Cornet. 

Cornish, V., and Kendall, P. F., calcite and

aragonite in shells............... 551

Cornu, F., acid reactions of minerals......... 473

color of salt.............................. 226

hibschite................................ 408

rock-forming apophyllitc................. 412

113750° 20 50
786 INDEX.

Page. 

Cornu, F., tests for calcitc and dolomite..... 563

See also Rcdlich and Cornu. 

Cornu, F., and Vctter, F., aragonite sinter... 199 

Coronadite....._..._. .......,.,......,. 532

Oorongamite, Lake, analysis of water...... 169,170

Corse, M. B.,nnd Bask&rville,C., analysis by. 514 

Corstorphine, G.. S.., matrix of diamond .. 320 

Cortesc, E., hot springs of Venezuela......... 238

CortijH., cited.............................. VI

Cortlandtite............................ 458,459,460

Cortlandtose................................. 460

Corundophilite.............................. 392

Corundum............................. 287,332-336

Corundum rocks....................... 334,462,464

Corynite .................................... -698

Cosalite.................................... 658,684

Cossa, A., synthesis of scheelitc.............. 706

tellurium in sulphur..................... 255

volcanic sublimates....................... 265

'Cossyrito............................................... '384

Costachescu, N., gasesinsalt.............. 226,739

Coste, E., origin of petroleum............... 735

salt and oil.. .......................... 224

Cotton, L, A,, diamond in dolerite.......... 321

Ootunnite.........................«.'...-...-. 680

Courantync River, analysis of v/ater......... 91

Cove Creek, Utah, .sulphur bod............... 184

Covcllite............................... 663,004,066

Coward, H. F. See Bone and Cov/:ard.

Cowcn, J. L,, arsenic mine................... 697

Cox,E. T,,antimcmyt>res.................... 697

phosphate rock........................... 524

Cox, G. H., zinc deposits. ..................... 682

Craig, A. W., and Wilsmorc, N. T. M., water

analysis ......................... 169

Cramcr, E., volatility of silica............... :267

Cransac, analysis of water from.............. 192

Crater Lake, analysis of v.ratcr................ 86

Craw, J. \V., analysis by.................... 193

Crawley, J. T,, and Duncan, E.. A., absorption of .potassium by soils........ £06

Credner, H., native copper...................... 001

Crednerite..................................... 668

Crenothrix.................................... 200

Crcnshaw, J. L. See Alien, Johnston, and

Crenshaw. 

Cresson, C. M.,citod........................ 72

Crinoids, composition of........................ 564

Cristobalite............................. 287,352-356

Crocidolite.............................. 379,383,384

Crocoite..................................... 687

Cronstedtitc................................ 392,576

Crook, A. R,., molybdenite.................. 705

Crook, T., dedolomitization................... 626

Crook, T,, and Davis, G. M., fluoriieinsand. 499 

Crook, T., and Jones, B. M.., .geikielitc........ 344

Crookcs, Sir W., artificial diamond......... 319,320

Crookcsite................................... <563

Crosby, W. O., coloration of clay............. 504

sandstone dikes......................... 539

Crosnier, L.,crystallized sands............... 536

Gross, C. F., and Bevan, E. J., lignocellulose. 747 

Cross, W., analcitebasalt.................... 366

analcite in phonolite.................... 444

classification of rocks.................. 419,421

Page. 

Cross, W., cpidoto. ..:....... ................ C01

garnet in rhyolito....................... 398

phlogopitc in r/yomingito............... 391

quartz-alunitc and quartz-diasporc

rocks.......................... 254,4&3

sandstone dikes......................... 539

topaz in rhyolitc........................... 405

See also Jddings and Cross. , 

Cross, W., and Hillcbrand, \V. F., cryolite.. 331 

Cross, Iddings, Pirsson, and Washington,

quantitative classification..... 421-429

Crossite..................................... 383

Crustaceans.............'................. 522,505,633

Crazy r/ell, analyses......................... 183

Cryohydratcs............................... 295

Cryolite..................................... 331

Cryophyllitc.............................. 387,391

Cryptomorphitc............................. 245

Crystallization, fractional, in magmas. -...... 305

Gubanitc...................................... 063

Cumberland River, analysis of water........ 79

Cumbcrlandite............................... 463

Cumcngc, E. See Friedel and umengc. 

Cumengeitc................................. 686

Cummingtonitc............................. 379

Cundcll, J. T., and Hutchinson, A., zincito.. 678 

Cunningham, J. See Lloyd and Cunningham. 

Cunningham, J. A.^ order of deposition of

minerals........................ 300

Cuprite..................................... 668

Cuprobismutitc............................. 007

Cuprodescloizitc.................;........... 689

Cuproiodargyritc....................... '..... 660

Cuprotungstite............................... 705

Curie, M.S., radioactivity................... 315

Curie, P., and Labcrdc, A.,hcat from radium. 307 

Currie, J., cited, on Stassfurt salts........... 210

Curtis, J. S., 'gold -and silver in quartz porphyry ........................... 031

origin of lead ores....................... 689

Cusack, R., molting points of minerals..... 286,287

Cushman, A. S., plasticity <of clays.......... 497

solubility -of minerals.................... 475

Cushman, A. S., and Hubbard, P., extraction of potash from feldspar...... 475

Custcrose.................................... 4CO

Cyanite. 'See Kyanitc.

Cyanochroite.-............................... 205

Cyiindrite................................. 084,090

Cymatolitc................................... 375

Cyrtolite.................................... 720

Czako, E., helium in natural gas............ *22

D.

Daeite..................................... 448,449

Dafert, F.W.,caliche........................ 250

Dahllite....... -............................ 350,519

Dahms, P., analysis by...................... 593

Dake, C. L., iron ores........................ 528

Dale, T, .N., slate............................. 545

Ball, W. H., ooquina......................... 559

Dall, W. H., and Harris, G. D,, .Florida

phosphates...................... 517

Dallas, mineral spring near, analysis......... 185
INDEX. 787

Page. 

Dalmcr, K., metamorphosis of phyllite....-.................:.. 394,400,614

Dalton, L. V., origin of petroleum............ 743

Daly, R. A., average composition of rode

types............................ 25,416

dolomite............-.............-...----- 571

evolution of limestones.................. 556

magmatic differentiation in Hawaii...... 292

magmatic stoping........................... 304

mctamorpMsm.......................... 591

origin of alkaline rocks................... 441

pro-Cambrian ocean...................... 138

sedimentary feldspars.................... 362

the fundamental magma................. 27'

Damiens, M. A.,'hydrocarbons from carbides. 731 

Damour, A. A., analysis by.................. 202

Icelandic geysers......................... 190

native platinum.......................... 708

prcdazzitc............................... 572

titauolivine.............................. 385

Damourite................................... 387

Dan River, analysis of water ................. 73

Dana, J. D., dolomitization.................. 566

gypsum andsalt................ ......... 224

serpentine............................... ti06

volume of ground water.................. 31

Dana, E. 8., thinolite........................ 151

See also Brush and Dana.

Dana, E. S., and Penfield, S. L., lead silicate 689 

Danalitc..................................... 678

Dannemoritc................................. 379

Danube River, analysis of silt.............. 500

analyses of water......................... 101

baphriitc.................................... 392

Darapskltc................................ 249,250

Darapsky, L., Chilean borates............... 244

Chilean nitrates.................... 249,250,252

Darton, N. H., Florida phosphates.......... 517

See also Clarke and Darton. 

Darwin, C., volcanic islands................. 305

Dathc, E.,-scapolite rocks.................... 600

Datolite....................................... 412

Daubf 6c, A.) alteration of bronze............. 664

arsenic in.sca water...................... 119

arsenic and .antimony in basalt_....... 631

associations of platinum..................... 710

calcination of serpentine............... 371,411

ferrous chloride in native iron............ 139

formation ofgalcna........................ 683

of hyalite and zeolites at Plombiercs.......................... 205,413

of olivinc............................ 385

fossil charcoal............................ 75-1

origin ofcassitcritc....................... 692

of native iron...................... 324,325

sea water and volcanism............... '279,281

solubility of orthoclasc................. 363,473

synthesis of apatite.................. 349

of brookite........................... :346

ofcassiterite....................... 348/690

of diopsidc........................... 374

.of onstaiite....-.- -................... 371

.of gahnite. ........................... C79

of hematite............................. 342

of quartz............................. 353

oftopaz.............................. 404

of willemite.......................... 679

of zinc ores........................... 079

zeolites at Plombieres.................. 205,413

Page. 

Daubrfo, A., and Mounicr, Q., native iron.... 324

Daubrdeilc................................... 697

Daubr&ilite.................................. 703

Daudt, H. W.,analysisby.................... 160

David, T. W. E., glcndonitc................. 151

matrix of diamond....................... 32i

Davidson, W. B. M., phosphate rocks...... 517,524

Davics, D. C,, Welsh phosphates............. 521

Davies, G. M. See Crook and Davics. 

Daviesite...................................... 086

Davis, C. A., diatoms in peat................ 205

marL...................................... 549

peat..................................... 751

Davis, E. P., chert........................... 541

Davis, N. J3., plasticity of clays............. 497

Davjson, C., loess............................. 595

Davison,J. M., platinum,.ctc., in meteorites. 710 

Dawson, £. M. See Van't Hoff, Kcnrick,

and Dawson. 

Dawson, J. W., origin of gypsum........... 240,578

peat...................................... 753

spore cases in coal........ 5.............. 771

Dawsonitc.. -................................ 494

Day, A. L., melting points of minerals....... 288

Day, A.L., and Alien, E. T., fusion of feldspars........................... 286,360

sublimation of feldspars.................. 268

syntheses of feldspars.................. 360,361

Day, A. L., and Shepherd, E. S., &kcrmanite silicate........................ 394

formation of quartz and tridymllc....... 355

lime silicates........................... 2S6,290

phase rule............................... 293

quartz glass.............................. 352

temperature of lava.................... -277,290

volatility of quartz..................... 268,352

volcanic gases......................'...... 260

Day, A. L., and Sosmsn, R. B.., feldspars.... 300

graphite- .............................. 322

melting points of minerals......... 286,2SS, 363

Day, D. T., filtration of petroleum........... 744

phosphate rock.......................... 520

platinum................................ 709

Day, D. T., and Richards, R. H., platinifcrous.sands...................... 703

Day, W.C., artificial asphalt................ 733

gilsonitc................................. 723

pitch coal................................ 728

Dead Sea.......................... 163-165,170,216

Dean, R. S., chert........................... 541

Death Gulch, water from.................... 2CO

De Bcnneville, J. S., potash in beryl......... 410

Debray, H., synthesis of apatite............. 350

synthesis of pyromorphitc............... 6S9

ofschcelite.......................... 7C6

of silver halides...................... 6CO

See also Deville and Detoray. 

Dechcn, H. van, cerusitc sinter.............. 688

Decomposition .of .rocks.................... 471-534

Dedolomitization............................ 626

Doe, River, analysis of water.................. 93

De Golyer, E., petroleum.................... 735

De Gouvcnain, , fluorine in Vichy water. 1S3 

De Groot, H., berates ................. 240,241,2)2

DC KTalbj C., Chile nitrates................._ 253

De Laana;.-, L. See Lauaay, L. De.
788 INDEX.

Page.

Delaware River (Kansas), analysis of water... 81 

Delaware River (N. J.), analysis of water..... 72

Delebecque, A., Lac Le'man................. 94

Delebecque, A., and Dnparc, L., French lakes 94 

Delesse, A., volume of ground water......... 34

Delessite.................................... 392

Pelkeskamp, R., barium in natural waters. 199,582 

bauxite.................................. 494

vadose and j uvenile carbonic acid........ 208

Delvauxite.................................. 712

Demaret, L., zinc deposits................... 674

Demarcay, E., vanadium.................... 712

Demel, W., dopplerite....................... 753

Demerara River, analysis of water........... 91

Dennis, W. D., cited........................ 243

Denudation, aerial.......................... 136

Denudation, chemical..................... 110-117

Denver, spring near, analysis, i......... °..... 182

Derby, 0. A., Brazilian diamonds........... 321

Brazilian topaz.......................... . 405

disintegration of rocks................... 477

gold on limonitei........................ 650

manganese ore. .......................... 533

novaculite.........................------ 540

occurrence of monaziteand xenotime..... 351

Derbylite................................... 697

Desaulesite.................................. 702

Deschutes River, analysis of water.......... 86

Des Cloizeaux, A., formation of anorthite..... 360

nickel ores............................... 699

Descloizite............................ 678,689,713

DC Smet, Lake, analysis of water.......... 160,171

Des Moines River, analysis of water......... 78

Deville, C. Sainte-Claire, dolomitization..... 558

fumaroles of Vesuvius................... 257

Deville, C. Sainte-Claire, and Leblanc, F.,

boric fumaroles.................. 240

volcanic gases......................... 257,258

volcanic sublimates..................... 265

Deville, H. Sainte-Claire, synthesis of cassiterite........................... 348,690

synthesis of hematite.................... 342

of magnetite......................... 340

of willemite......................... 679

of zeolites......................... 413,414

of zircon............................. 349

titanium and vanadium in bauxite.... 495,712

topaz.................................... 404

water analyses.......................... 94,97

Deville, H. Sainte-Claire, and Caron, H.,

synthesis of apatite.............. 350

synthesis of cassiterite................. 348,690

of gahnite........................... 679

of pyrornorphite..................... 688

of rutile............................. 346

of staurolite (?)...................... 407

of zircon............................. 349

Deville, H. Sainte-Claire, and Debray, H.,

native platinum............... 708,709

synthesis of cinnabar.................... 671

Deville, H. Sainte-Claire, and Troost, L.,

occlusion of gases by glass....... 270

synthesis of greenockite and wurtzite.... 676

Deville, H. Sainte-Claire, and Wohler F.,

boron nitride.................... 239

Devils Inkpot, analysis of water............. 194

Devils Lake, analysis of water............. 160,173

Page. 

Dewar, J., cited............................. 45

Dewar, J., and Ansdell, G., gases in meteorites....................................... 282

Dewey, F. P., solubility of gold............. 651

Deweylite. -................................. 411

De Wilde, P., gold in sea water............... 121

origin of petroleum...................... 738

Diabantite................................ 392,603

Diabase............................... 455,456,483

Diallage................................... 375,378

Diamond ................................. 317-322

Diaphorite................................ 658,684

Diaspore.............................. 333,491,493

 Diatom ooze........................... 129,508,511

Diatoms, as sources of petroleum............ 742

in peat.................................. 205

Dick, A. B., minerals in sand............... 498

Dick, W. G. See Adams and Dick.

Dickson, C., formation of barite............. 584

Dickson, C. W., nickel deposits.............. 700

platinum ores............................ 711

Dickson, E. See Holland and Dickson. 

Dieffenbach, 0., gold on siderite............. 650

Diersche, M., origin of graphite.............. 322

Diesel, W., testsforcalciteandaragbnite. -... 550 

Dietze, A., water analysis................... 92

Dietzeite.................................. 250,703

Dieulafait, L., ammonia in sea water........ 119

barite................................... 582

bitumen in shale........................ 739'

boric acid in natural waters............. 191

Chilean nitrates......................... 251

copper in sea water...................... 120

lithium in sea water..................... 119

manganese in sea water.................. 120

manganese nodules...................... 131

origin of borates......................... 247

precipitation of iron ores................. 574

serpentine............................... 607

strontium in sea water.................. 120

sulphur deposits......................... 580

thermochemistry of iron and managanese........................... 533,534

vanadium............................... 713

zinc and copper in rocks................. 632

zinc in limestone........................ 680

in sea water......................... 120

Diller, J. B., alteration of pyrope............. 399

loess. ..................................... 505

meliliteand gehlenitein slags............. 395

occurrence of perofskite.................. 345

priceite.................................. 243

quartz basalt............................ 357

sandstones............................ 538-539

See also Clarke and Diller. 

Dinsmore, S. C., analyses by................ 87

Diopside.................................. 287,374

Dioptase.................................... 669

Diorite................................ 450,451,483

Dipyre...................................... 400

Dissociation in magmas..................... 293

Ditte, A., metals in the atmosphere.......... 54

origin of vanadates...................... 713

 synthesis of apatite...................... 350

of cassiterite....................... 348,691

of cinnabar.......................... 672

of greenockite....................... 676
INDEX. 789

Pago. 

Dittler, E., melting points of silicates........ 288

synthesis of plagioclase.................. 301

of wulfenite.......................... 088

See also Ballo" and Dittler, Doelter and

Dittler. 

Dittler, E., and Doelter, C., bauxite......... 494

Dittmar, W., analyses of dissolved air.. 47,140,141 

analyses of ocean water................. 23,122

oceanic salts............................. 23

water of Ilayes River.................... 88

Dittmarite................................... 510

Ditroite..................................... 441

Dittrich, M,, decomposition of rocks... 473,482,490 

relations between spring waters and rocks. 207 

Ditz, H. See Donath and Ditz. 

Divers, E., and Shimidzu, T., tellurium in

sulphur.......................... 205

Dniester, River, analysis of water............ 103

Dodge, J. A., analysis of water............... 83

Doelter, C. ( alteration of andalusite.......... 400

constitution of pyroxene................. 379

formation of augite...................... 378

of anorthite.......................... 3CO

of magnetite......................... 340

of melilite.......................... 1 390

of spinel............................. 338

fusibility of rocks........................ 290

fusion ofclinochlore................... 378,393

ofepidoto.......................... 378,402

of garnet...................."....... 378,397

ofglaucophane.'.................... 384,390

of micas........................... 378,391

of tourmaline...................... 390,409

gehlenite in limestone................... C25

magmatic dissociation................. 293,297

melting points of minerals......... 280,287,290

solubility of minerals.. 347,475,033,084,091,095 

solvent of gold........................... 051

stability fields of minerals............. 298,301

synthesis of acmito...................... 375

of bournonito........................ CC7

ofcinnabar.......................... 071

of covellite and chalcqpyrite......... 004

of feldspar........................... 301

of galena............................. 683

of hornblende........................' 381

' ofjamesonite........................ 084

ofleucite............................ 304

of mcionite.......................... 400

of mica.............................. 389

of nephelite and kaliophilitc....... 307,308

of olivine............................ 380

of pyrite and pyrrhotitc........... 328,329

of sulphosalts........................ 059

of vvollastonite....................... 373

of zeolites............................ 413

volcanic chlorine......................... 139

volcanic explosions...................... 280

Doelter, C., and Dittler, E., the silicate

MgAl2Si06........................... 382

Doelter, C., and Hoornes, R., dolomitization. 507 

Doelter, C., and Eussak, E., formation of

anorthite........................ ' 300

formation of melilite..................... 390

ofspinel............................. 338

fusion of garnet........................... 397

of mineral mixtures.................. 303

of vesuviauite....................... 399

Page. 

Docring, A-., analyses by.................... 92,230

cited..... ...... J ........................^ 1C1

Doherty, W. M., manganese nodules......... ' 531

Dolbear, S. H., magnesito................... 573

Dole, R. 13., analyses of water.. 08,70,72,73,74,75,

70,77,79,80, £2, S3

brines of Silver Peak Marsh.............. 177

rejoinder to Shelton..................... 151

statement of water analyses.............. CO

Dole, R. B., and Chambers, A. A., analyses

of water......................... 87

Dole, R. B., and Stabler, H.;chemical denudation.. .......................... 112

silt carried by rivers: ....I.:............. 501

Dolcrophanite............................... 205

Dolomite...................... 242,413,557-573, G2G

Domey kite.......................:........... 003

Domingitc.................. I................ 084

Domoshakovo, Lake, analysis of water... 107,171 

salino deposits........................... 228

Don, River, analysis of water................ 93

Don, J. Redistribution of gold.............. 047

gold in sea water........................ 120

solvent of gold........................... C51

Donath, E., action of nitric acid on coal...... 757

extracts from coal........................ 772

humus substances.../................... 758

Donath, E., and Briiunlich, F., reactions of

lignite............................ 757

Donath, E., and Ditz, H., reactions of lignite 757 

Donath, E., and Manouschek, O., hydrocarbons from coal................ 772

Dopplerite................................. 752,753

Doss, B., anatase psoudomorphs............. 340

artificial hematite........................ 342

grahami te............................... 728

melnikovite............................. 330

pseudobrookitc.......................... 344

sand in gypsum......................... 535

synthesis of rutile and anatase........... 340

Doubs, River, analysis of water.............. 94

Doughty Springs............................ 199

Douglas, J. A., volume of molten minerals... 290 

Douglasito................................. 219,220

Douro, River, analysis of water.............. 94

Drabble, G. C., see Wcdd and Drabble. 

Dragendorff, J. G. W., analysis of water..... 103

Draper, D., and Goodchild, W. H., origin

of diamond...................... 321

Drasche, R. von.eclogite.................... C01

Dresser, M. A., Sudbury ore................. 700

Drevermann, A., syntheses of lead ores...... 088

Drew, G. H., bacterial precipitation of colcium carbonate................ 547,503

Drown, T. M., chlorine maps............... 53

Duane, W., heat from radium............... 307

Duboin, A., synthesis of kaliophilite......... 308

synthesis of leucite...................... 304

Dubois, E., atmospheric transport of salt.... 54

chemical denudation.................... 147

circulation of calcium carbonate......... 128

ratio of sodium to chlorine in rivers...... 139

Du Bois, G. C., laterite................... 488,489

Ducatte, F., siflphosalts of copper........... 007

sulphosalts of lead....................... 084

Ducloux, E. n., analysis of sea water........ 122

103SS.................................... 504

mineral springs of Argentina............ 211
INDEX.

Pago. 

Dudley, W. L.,vivianite.................... 510

Dufilold, S. P., analysis cited., -.............. 177

Dufrcnite................................... 510

D uf renoysite................................ 084

Duinas, J. B., origin of boric acid............ 240

synthesis of argentite.................... 655

Bumble, E. T., grahamite..................... 728

iron ores............................... 578

Dumont, J., decomposition of potassium carbonate by clay.................. 493

solubility of rocks.......................... 475

Dumortierite............................ 408,619

Duncan, R. A. See Crawlcy, J. T. 

Dundasite.................................. 494,084

Dunin-Wasowicz and Horowitz, J., analysis

by............................. 182

Dunite............................... 386,458,460

Dunn, 12. J., diamond....................... 320

Dunn, J. T., barium and strontium in mine

waters.......................... 582

Dunn, W. H., analysis of salt................ 225

Dunnington, F. P., deposition of manganese. 534 

titanium in clays........................ 495

Dunose..................................... 400

Dunstan, W. R., laterite.................... 489

Duparc, L., analysis of water................ 94

hot springs.............................. 550

transformation of pyroxene.............. 380

Uralian platinum....................... 709

See also Delebccque.

Duparc, L., and Holtz, H. C., Uralian platinum........................... 707

Duparc, L.,andHornung,T.,uralitization. 380,592 

Durand-Claye, L., cited..................... 122

Durocher, 7., copper sulphide............... 664

liquation in magmas.................... 305

synthesis of argentite.................... 055

of cinnabar.......................... 071

of dolomite........................... 558

of galena............................ 083

of grecnoekite and sphalerite........ 670

of pyrite............................. 328

ofstibniteandbisrauthinitc......... -695

ofsulphosalts....................... 658

the fundamental magmas-............... 802

Durun Lake................................ 162

Dust, atmospheric ......................... 54,136

Dutoit, A. L., matrix of diamond........... 320

Dntton, C. E .j radioactivity and voleanism.. 310 

Dwina, Kiver, analysis of water............... 103

Dyscrasite.................................. £54

Dyson, F. W., radium in the sun............ 312

Dysprosium................................. 16

E.

Eakins, L. G., analyses by........... 183, 338,377,

432, 440, 450, 451, 452, 459,

460, 500, 544, 556, 571, 017

fluorine in fossil bono................. 520

xanthitane.............................. 345

Eakle, A. S., lawsonite..................... 407

E ast Saginaw, brine, analysis of............. 178

Eoton, F. M. See Van Winkle and Eaton. 

Ebaugh, W. C., and Macfarlane, W.,-Great

SaltLake........................ 153

Ebaugh, W. C., and Williams, E., Great Salt

Lake........................... 153

Page. 

Ebolrnon, J. J., synthesis of boryl............ 410

synthesis of bunscnito................... 701

ofchromito.......................... 703

of enstatite.......................... 371

of forsterite.......................... 385

of gahnite........................... 079

of magnetite-........................ 340

of perof skitc......................... 344

of rutile............................. 340

Eberhard, G., scandium..................... 19

Ecdomite.................................. 689

E chinoderms, comp osition of................ 565

Eckcl,E.C.,gypsum....................... 220

limestone and comcnt.............'...... 555

phosphorite............................. 523

slate................................... 545

See also Hayes and Eckcl. 

Eclogite............................... 320,398,001

Eddingfield, F. T., deposition of gold....... 652

Edenite..................................... 380

Edingtonite................................. 412

Edwards, M. G., aluminum hydratesin clay. 494 

Eger River,analyses of water.............. 99

Egger,E., analyses of water............... 97,93

Egglestone, W. M., fluorspar................ 585

Egleston, T., solvents of gold................ 651

Eglcstonitc.................................. 670

Ehrlich, T. See Kolkwitz, R.

Eichlciter, C. F., arsenical spring............ 184

Eilers, A., platinum and palladium in copper. 711 

Eisenhuth, K., analysis by.................. 575

Eitcl, W., sillimanite........................ 406

ElECOlite.................................. 367-371

Elseolite syenite......................... 440,482

Elatcrite.................................... 727

Elbe River, analyses of water............... 99

E Ibow TUver, analysis of water.............. 83

Eldridge, G. H., asphalt.................. 728,730

Florida phosphates...................... 524

Electrical activity in ore bodies............. 644

Elcctram................................... C48

Elements, distribution...................... 13-21

nature.................................. 12

periodic classification.................... 36-40

relative abundance...................... 22-35

table of................................. 13

Ellery, H. H., precipitation of silver........ 657

Ellis, E. E., sine deposits.................. 682

Ellis, W. H., anthraxolitc................... 762

Ells,R. W.,manjak......................... 729

Elschner, C., phosphate rock................ 526

Elsden, J. V., chemical geology.............. 11

Elsworthy, R. T., mineral springs of Canada. 211 

Elton Lake, analysis of -water............. 166,170

Embolite. .. ...............'................ 242,660

Emerson, B. ~K., amphibolite................ 595

anda'lusi te and sillimaultc .............. 615

emery................................... 335

serpentine............................... 606

Emery................................ 332,335,496

Emmons, S. F., fluorite....................... 585

loess..................................... 505

ores of Leadville. ......................... 689

platinum................................ 711

secondary enrichment................... 643

serpentine............................... 006

silver in eruptive rocks.................. 031

zinc ores................................. 682
INDEX,

Page. 

Emmons, W. H., manganese and gold........ .652

/mine waters............................... 635

molybdenite................................ 33D

.secondary enrichment........................ 643

Emmons, W. H., and Harxington, G. L.,

mine waters...................... 635

 Emplcctite........................................ 667

Enargite..................................... 667,668

E ndell, K., acids of moor waters............... 479,,

origin of kaolin........................... 48.7

Sac also Smits and Endcli. 

Eadofl, K., and Rieke, R., cristobalitc..... '352,.355

spodumenc................................... 376

Endemann, H., asphalt...................... 733

Endlichite......................_.............. 688

JSngelhardt, A., phosphate rock............... 520

Engelhardt, F. E., analysis by................ 178

Englcr, C., artificial petroleum._.......... 733,734

origin of .petroleum.................. ;738,739,743

Engler, C., and Lehmann, T., artificial petroleum.................:.......... . 733

Engler, C., and .Severin, E,, -artificial petroleum. .... .....-._..,............ 733

Enstatite.................................. .287,371-373

.Epocue'n, Lagoon, analysis of water.,....... 161,171

.Epiboulangcrlte............................... 684

Epichlorite..._............................... '392

 Epidosyte...................................... 403

.EpidotO.....................,..,........... 402,403,600

Epidotcrocks............................ £00,601,602

Epidotization........................... 403,600,601

Epigonito.......................................... 667

:Epistilbitc................................... 412

.Epsomitc..................................... .218,537,250

.Erbium............................................ 16

Srdmann, , water analysis................ 168

Erdinann, E., blue rock salt..................... 226

 Stassfurt.salts........................ 216,218,221

Erdinann, H.,abundance of nitrogen.......... 34

nitrogen in.mincrals................. ... 269

Uric, Lake, analysis of water..................... 70

Erinite............................... -......,,... 668

Erionite......................................... 412

Er'lau, River, analysis of water................ 101

EroftSef, M., andXatschlnoff, P., diamondsin

meteorite......................... '319

 Erwin, E. W.,-eited.......................... .52

Erythrite........................................ 701

Erythrosidorite................................ '265

Eschcr, B. G., igneous rocks....................... 470

 Essen, J. von, solubility of carbonates........ 547

Esseqmbo Uiver, analysis ol water.......... 91

Essoxose.................................... 438,454

Etard, A., and Olivier, L., reduction-of-sulphates by microbes................... 579

Eltingcr, . 'SceFranckandEttingcr.'

 Exicaitito. -.................................... '658

:Eucryptrito.......:................ '367,-3eS, 375,:376

Euctolite...................................... 454

Eudialyte................................... 718

Euplcctella.................................. 511

'Europium..................................... 16

Eutectics.............................. '295-298,419

Euxcnlte................................... 714,718

E vansito.................................... 516

Evans, J. R., analyses of water..... ..74,75,76,79,82

Page. 

Ex-ana, J. "W".,analcltcinmonchiquite....... 363

quantitative classification............... 429

Evans, N.TST., analysis by................... G22

Eve, A. 'S., radioactivity................... 121,308

Eve, A. S., and Mclntosh, D., radioactivity. 309 

Everding, H., Stassfurt salts................ 216

E.wald, , analysis by..................... 200

Ewing, A. L.,limestone erosion............. 557.

Excelsior Spring, analysis................... ISO

Eydmann, E. See Kohlschiitter and Eydmann.

Tahlunitc................................... 402

Pailycr, G. H., barium in soils............... 14

See also Schreincr and Fallyer. 

l? ailycr, G. H., and Breese, C. M., nitrogen

compounds in rain............... 52

Failycr, G. H., Smith, J. G,, and Wade, H. R.,

composition of soil particles....... 499

Fairbanks,.!!. W., analcite-diabase............ 366

tin deposits............................... 693

Fairchlld, IL L., planetcsimal hypothesis.. 58,138

 Fairhaven.Springs, analysis................. -188

Tamatinite.................................... 607

JFarr, C. C., and.Florance, D. C. H., radiumin

rocks....._...................... 309

JEarrington, O. C., formulae!iolitc,......... 401

meteorites........................._....... 41

.Farup, P. See Van't Hoffi and Farup.

Faujasite.................................... 412

Tayalitc..................................... 385,421

Field, W., synthesis of pyritc................. 329

feldspars.................................. 358-363

alterations of....................... 363,597-602

melting points............................ 287,360

sublimation of............................ 268

J?cmic minerals.............................. 423

rocks........................'.'....'.'. 437,458-461

Tenncl, A. C. £ce Judge, J.. F.

JPauneman, N. M., petroleum.................. 72'r>

JEenncr, C. N., rcsorption of olivinc........... 222

silica......'..'.."......................... 352,355

iFcrbcritc..............................'.:........ 705

Tcrguson, H. G., tin in Virginia... '.. ........ 693

 Ferguson,, J. B., reactions between .gases..... 274

.Ferguson, J. B., and Merwin, H. C., cristobalite and tridymitc............... 287

Fergusonite............................... 313,720

Fermor, L. L.,garnet...."........ .........-... 397

garnet rocks................................ .398

latcrite.-..............................~.. 489,490

manganese ores..................._....... 532

quantitative classification of igneous rocks 429 

.quartz-barite rock.......................... '584

Fernandez and Bragard, analyses by ........ 583

Feraandinitc.................................... 714

.Fernekcs, G., precipitation of copper........ 662

terrier, W. F., phosphate rock................ 519

Iterricrcs and Dupont, synthesis of bunscnito 701 

of zincitc................................ 679

iFcrritungstitc ................ J................ 705

 Fcrrodolomito............................... 575

.Fersmann, A. E., relativc abundance o'f elements....... ........................ .27

Fibrolite.'............................_....... 405
792 INDEX.

Page. 

Fichtelite.................................. 727,753

Ficdlerite.................................... C86

Field, F., analysis by........................ 576

silver in sea water....................... 120

synthesis of copper minerals........... 668,669

Finckh, R. E., organisms at Funafuti....... 568

Finckh, L-., igneous rocks.................... 470

serpentine from gabbro.................. 411

Finkbiner, N. M., analysis by............... 86

Finlay, G. I., calculation of norms........... 428

dumortieri te............................. 408

Finlayson, A. M., genesis of lead and zinc

ores........................... 680,681

Finn, C. P. See Cohen and Finn.

Fircks, W. von, tin deposits................. ' 691

See also Beck and Fircks. 

Firkct, H., dolomite......................... 571

Fischer, F., coal analyses.................. 756,759

Fischer, H., formation of oojite............".. 551

mercury deposits..^..................... 674

Fischer and Rust, microscopic structure of

coal............................. 771

Fischer, T. See Wedding and Fischer. 

Fischerite................................... 516

Fish Creek, analysis of water................ 88

Fisher, O.,criticism of Joly.................. 147

internal t emperature o f the earth........ 285

Fisher, W. W., water of Thames............. 94

Flagg, J. W., Chilean nitrates................ 249

Flechsig, R., analysis by.................... 188

Fleck, H., water analysis.................... 164

Fleck, H., and Haldane, W. G., carnotite.... 716

Flcischer, A., volume of molten basalt....... 290

Fleissner, H., diamonds in slag.............. 318

Fletcher, A. L., melting points of minerals... 286

radioactivity of rocks.................... 309

See also Joly and Fletcher. 

Flint.................................. 352,540-543

Flint River, analysis of water................ 74,75

Florance, D. C. H. See Farr and Florancc. 

Flores, T., tequesquite....................... 234

Fliickiger, F. A., analysis by................ 194

Fluocerite................................... 331

Fluorine, distribution....................... 16

free,in fluorite-.......................... 331

in mineral waters................... 69,187,188

in sea water............................. 118

in volcanic gases......................... 255

Fluorite......................:.... 199,287,331,585

Fluorspar. See Fluorite.

Foerste, A. F., Clinton iron ores............. 529

Forstner, H., wurtzite as furnace product...674,676 

Fobs, F. J., fluorspar........................ 585

Foote, E.A. See Kocnig and Foote.

Foote, H. W., analyses by......... 339,444,454,703

calcite and aragonite..................... 549

See also Penfleld and Foote. 

Foote, H. W., and Bradley, W. M., analcite. 363 

. nephelite................................ 367

Foote, W. M.,leadhillite.................... 687

Foraminifera................................ 565

Forbes, D., borate from hot springs.......... 247

Chilean nitrates......................... 249

South American borates................. 244

Forbes, E. H. See Penfield and Forbes. 

Forbes, R. H., and Skinner, W. W., water

analyses......................... 83

Page. 

Forbesite.................................... 701

Forchhammer, G., chemistry of the ocean. 118,120 

heavy metals in rocks................... 630

magnesia in shells and corals........... 554,563

synthesis of apatite...................... 349

Ford, W. E., formula of dumortieritc........ 408

See also Penfield and Ford. 

Forel, F. A., on Lac Leman................. 94

0 Formaldehyde in atmosphere................ 46

Formentj, C., bauxite....................... 492

Formula, constitutional................... 603-605

Forsberg, -. , cited....................... 122,124

Forsberg, E. See Geuthcr and Forsberg. 

Forsterite......................... 372,384,385,421

Forstner, W., mercury ores.................. 674

Foster, C. Le Neve, Owens Lake............ 234

See also Bauerman and Foster. 

Foulk, C. W., analysis by................... 178

Foullon, H. B. von, gummite................ 715

nickel deposits......................... 699,701

Thodusitc................................ 383

Fouqud, F., formation ofmclilite.......... 394,395

magmatic differentiation................ 292

steam from Etna........................ 255

volcanic gases................. 258,259,260,262

Fouque", F., and Gorceix, H., boric fumaroles 240 

Fouqu6, F., and Michcl-L^vy, A., crystallization ofsilica..................... 356

formation of hematite.................... 340

of magnetite......................... 342

of melanite.......................... 398

of nephelite........................ 367,368

of spinel............................. 338

fusion of biotite and microcline........ 364,443

of scapolite rock................... 401,599

synthesis of augite....................... 377

ofenstatite.......................... 372

offeldspars........................ 360,361

ofleucite............................ 364

of melilite........................... 395

of mica trachyte..................... 389

of olivine.......................... 385,386

Fournet, J., synthesis of chalcopyrite......... 66

synthesis of zinkenite.................... 684

Fox, C. J. J., carbon dioxide in sea water.... 143

Fox, R, W., electrical activity in tire bodies.. 644 

Foyaite...................................... 441

Fraas, 0. F., formation of bitumen........... 740

Fraatz, T. See Werner and Fraatz.

Franchi, S., glaucophane rocks.............. 594

jadeite rocks............................. 376

Franchi, S., and Stella, A., lawsonite in schist 407 

Francis, W. D., iron ores.................... 528

Franck, L., and Ettinger, diamonds in steel.. 318 

Franckeite................................ 684,690

Francolite................................... 519

Frank, A., iodine in potash salts............. 218

Frankforter, G. B., water from Death Gulch. 200 

Frankland, P. F ., coal gas................... 764

water analysis........................... 91

Franklin, E. C. See Bailey, E. H. S. 

Franklinite........................ 338,678,679,682

Fraps, G. S., and Tilson, P. S., water of Rio

Grande.......................... 82

Frazer, J. C. W., and Hoffman, E. J., experiments on coal.................... 772

See also Kastle, J. H., etc. 

Frazer, P., classification of coals........... 764,765
INDEX. 793

Page. 

Frear, W., and Beistle, C. P., soils........... 503

Frech, F., carbon dioxide and climate....... 49

 Frechette, H., magnesite.................... 523

Freda well, analysis cited.................... 181

Freda, G., volcanic sublimates.............. 205

Free, E. E., aerial denudation............... 136

Freis, R., fusion of mineral mixtures........ 300

Freieslebenite............................. 658,684

Fremy, E., artificial coal.................... 769

composition of bones.................... 521

humic substances in coal.............. 756,757

synthesis of anglesite.................... 687

of cerusite........................... 685

Frenzel, A., Bolivian tin ores................ 690

formula of pseudobrookite............... 344

mine water.............................. 636

Fresenius, C. R., analysis by................ 180

manganese and iron in spring waters..... 533

Fresenius, H., analysis by................... 164

Friedel, C., diamond........................ 318

lead oxychlorides........................ 686

nesquehonite............................ 561

synthesis of atacamite................... 608

Friedel, C., and Cumenge, E., carnotite...... 716

Friedel, C. and G., alteration of muscovitc... 391 

artificial cancrinite.................... 370

conversion of muscovite into nephelite... 368 

formation of leucite...................... 364

syntheses of feldspars.... r............. 360,362

Friedel, C., and Guerin, J., synthesis of ilmenite............................... 343

Friedel, C., and Sarasin, E., formation of

quartz and feldspar.............. 361

synthesis of analcite................... 365,413

of hopeite........................... 678

of phosgenite........................ 686

of quartz and tridymite............. 353

of topaz............................. 404

Friedel, G., hydration of analcite............ 364

lead oxychlorides........................ 686

synthesis of corundum................... 333

of kaliophilite........................ 368

Friedel, G., and Grandjean, F., synthesis of

chlorite.......................... 393

Friedliinder, J., artificial diamond........... 318

Friedmann, A., analysis by................. 164

Frieseite..................................... 658

Frio, Rio, analysis of water.................. 92

Friswell, R. J., action of nitric acid on coal.. 757 

Frochot, M., tin deposits.................... 694

Frommel, J. See Clermont and Frommel.

Fruh and Schroter, peat..................... 752

Fuchsite..................................... 387

Fuller, M. L., corrosion of quartz.......... 358,476

volume of ground water................. 34

Fuller's earth................................ 503

Fumaroles................................. 257-264

Fumaroles, boric............................ 238

Funafuti, atoll of.......................... 567-568

Funk, \V., decomposition of feldspars......... 475

Fyris, River, analysis of water............... 103

G. 

G abbro.................................... 456-458

Gabbro-nelsonite............................ 403

Gabriel, G. A..cited......................... 78

Gadolinite................................... 719

Page. 

G adolinium................................. 16

Gaertner, A., bog iron ore................... 528

Gagel, C., and Stremme, H., origin of kaolin. 487 

Gages, A., synthesis of serpentine............ 410

Gahnite............................... 338,678,679

Caize...........:...................... 539-540,542

Gale, H. S., carnotite........................ 716

colemanite......................:....... 243

magnesite............................... 573

salines of Great Basin................... 230

Gale, H. S., and Schaller, W. T., minerals of

Searles Marsh:.................. 242

Gale, L. D., cited............................ 152

Galena............................ 266,683,684,750

Galenobismutite............................. 684

Gallium, distribution....................... 16,675

Ganomalite.................................. 689

Cans, R., clay silicates...................... 495

Garda, Lago di, analysis of water............ 96

Gardner, R. F., analysis by .................. 227

Garnet............................ 396-399,601,604

Garnet rocks...................... 398,601,602,627

Gamier, J., nickel deposits................ 700,702

Garnierite................................... 702

Garonne, River, analysis of water........... 94

G arwood, E. J., calcareous algse............. 5.53

Gas, natural............................... 721-723

Gases in coal.......................... 765,766,767

Gassner, L., phosphatization................ 557,

Gassner, L., and Mahler, C., precipitation of 

metals................................... 645

Gaubert, P., cristobalite..-................... 352

G aukhane Lake, analysis of water......... 166,170

Gautier, A., arsenic in sea water.............. 119

chemistry of volcanism................ 275,279

decomposition of galena................. 684

fluorine in volcanic gases................ 256

fumarole gases........................... 256

galena................................... 684

hydrogen in atmosphere......... '........ 45

iodine in sea water....................... 118

juvenile and vadose waters............ 208,209

minervite................................ 518

nitrogen, argon, arsenic, iodine in granite. 433 

occluded and volcanic gases.......... 271,272,

273,274,278 

origin of nitrates......................... 252

reduction of copper sulphide............. 662

thermal springs and volcanism.......... 208

Gautier, A., and Clausmann, P., fluorine in

natural waters.............. 69,118,1S7

Gautier, F., tin deposits..................... 692

Gay-Lussac, cited........................... 51

formation of hematite................... 342

Gaylussite............................. 157,233,242

Gebbing, J., cited........................... 96

Gebbart, H., synthesis of barite............. 584

Gedrite...................................... 379

Gedroiz, H., humus in soils.................. 479

Gegenbaur, V., water of the Adriatic........ 121

Gehlenite............................. 394-396,604

Geijer, P., magnetite syenite.............. 464

Geikie, Sir A., bog iron ore.................. 528

elevation of continents................... 31

order of raagmatic eruptions............. 304

saline matter in rivers................. 112,113

temperature of molten lava.............. 290
794 INDEX.

Page. 

.Geikielite.................................... 344

Geitner, C., synthesi s of aigentitc............ 655

synthesis of beyrieWte....-..-.-.,....... £99

of greenockite... ........................ 676

efpyrlte............................. '329

Gcnesee Baver, analysis of water............. 70

Genth, F..A.,alterationofcorunduni."....... 336

alteration of orthoclase to albitc......... 363

of talc.......................... -..380,411

analyses by...........,.-.-...- ~........ 164,611

guminite...- -.............. .._......... .715

lansfordite................................... 561

pseudomorphouscassiteritc.................. «91

vcrmiculitcs............................. 392

water of Dead Sea.......................... 164

Genth, F. A., and .Penfield, S. L., ncsquchonite............................. Ml

Genthite..................................... 7.02

Geocronite...... ........................... .684

Geological thermometer................... 223,355,624

George, E. D..,ltungsten deposits...-._.... .706

Georgjadesite.,........................ .....,..-.-....... fiSD

Gorhardtite......., .... ..................... £69

Germanium..'..................,............... _........... 16,-6.75

Gcrsdorffite.......................... .,.- ....,. £98

Ccnther,, A., formula .of gypsum.. ........... .218

Geuther, A., and Forsberg, E., .synthesis-of

wolframite........................ 706

Geyserite,,,.......................... ... ,.. -202

Gibb, A., .and Philip, R. G., precipitation «f

silver sulphide.................. '656,657

Gibbsite...................... ......... 490,491,492,493

(Gibson, J.^analysistofinanganesejiodule.-.. 131,132

See also Irvine,, JR.. 

Giebeler, H.,, radium in Nova Geminorum.... 312

 Gigantolite............... ..................... 402

Gil,J.C., fluorinein spring waters............. 188

barium,, etc,, in sprang waters-.... ......... 180

Gila Eiver, analysis of water................. 83

Gilbert, G...K, Lake Bonneville................ 152

mirabllite at Great Salt Lake................ 228

salts of Sevier Lake............................. 229

tufa...................................... '548

Gilbertite.......,.................................. 387

Giles, W.B.,bakerite.......................... 243

%Gillman, J1 ., nickel deposits................. 700

Gilpin, J. E.j, .and Bransky, O. E., fuller!s

earth.................................. 744

iGilpin, J. E., and Sehneebergerj P., fuller;s

earth.................................. 744

'Gilsonite,.......,...,...........,.. . 727,728,730

fGinsburg,.A. S.^.synthesis of nephelite....... .368

iGinsburg, I.., kaolin.............................. -487

Girard, C,, and Bordas, J?., sprang deposits... 199 

fGirardin, J., magnesian travertine............. -559

'Girty, G, H.,phosphate beds................. .521

iGismondite ................................... 412

(Glance coal............................................... ,754

Ctlasenapp, M., niter in sandstone...... ... .248

Glaser, M. fifee.'Ealmarm., W.

(Glasente,....................................... :218

'Glass, occlusion of gaseslDy................... '271

Glasser, B^Jiepouitc........................... 702

iGlauberitc................................. 218,242,250

iGlaucochroite................................... 375

.Glaucodot....................................... C99

iG-lauconite..-.....-............ 133,134,.511-515,576

Page. 

Glaucophane........... >................... 383,384

Glaucophane schists...................... 384,594,, :595

Gleditsch, E., uranium and .radium........... 312

Glendoriite................................... 157

Glenn, "W., chromite deposits................ 70-1

Glinka, K., glaucoriite...................... 513,514

kaolin...................................... 494

weathering of minerals.................. 478

GJobigerina ooze......................... 129,508,551

Glucinum, distribution...................... 16

Gmeliriite................................... 412

Gmundenersee, analysis of water............. C6

Gneiss.................................. 482,621-623

Goebel, A., cited............................. 166

Gockel, A., radioactivity of rocks............ 309

Godeffiroy, E., analysis of water............. 96

Gorgcy, R., salts of Hall, Tyrol............... 222

Goessmann, C, A.,, analyses by............ 178,227

Goethite....................................... 527

G-atz, J., ottrelite rocks....................... 616

Gold, distribution............................. 16

in coal.................................... 650

in igneous rocks......................... 328

in sea water........................... 120,121

ores of................................. 646-653

solvents of............................... 650,651

 fioldberg, A,,.cited ...,....... ..'......_......... 188

Gjoldsberry, P. See Kraus and Goldsberry.. 

Galdschmidt, V., composition of tourmaline. 

Goiaschmidtite.................................. 649

G.ooch, F. A., ana'lyses'by................... 198

Goocb, F. A., and Whitfield, J. E., analyses

by.......................... 188,190,194

Goodchild, W. H., gold in sulphur........ 266V 650

ore deposits............................. 646

pFite................................... 330

Sudhury ores............................. ^.. 700

See also Draper and Goodchild. 

Gaodenough Lake, analysis of water........ 160, 172

GJOOSC Lake, analysis of water................ 86

Gorby, S.'S., petroleum....................... 742

Gorceix, H., volcanic gases................... 262

See Fougu6 and Gorceix. 

Gordon, C. H., change of augite to hornblende......................... 593

nomenclature of gneiss................... 621

;Gorgeu, A., analyses by...................... 532

synthesis of layalite...................... 386

ofncphelite.......................... 368

of pseudo-wollastonite............... 373

of pyroxene.......................... 374

of spessartite.......................... 398

of willcmite......................... .679

of zincite............................... C79

wad..................................... 531

Gortner, B. A. See Alway, F. J. 

Gorup-Besanez, E. von, formation of magnesian carbonates................ 559

Goslarjte...................................... B7S

Gosling, E. B.j ozokerite...................... 728

Goss, A., water analysis........................ '83

Gosselet, J., phyllites........................ 616

Gossncr, B., on glaserite .................. 218

 Gottlieb, E.j analyses of wood............... 747

iGotlschalk, V. H., and Buehlcr, H. A.,electrical activity in ore bodies....... 644

See also Buehler and Gottschalk.
INDEX, .795

Pago. 

Gouvenain, C. A. de, alteration of bronze.... 665

Goyder, G. A.,sulvanite.................... 713

Grabau, A. W., classification of sedimentary

rocks............................ 035

Graftiau.J., cited........................... 52

Graham, R. P. D. See Poitevin and Graham. 

Graham, T., colliery gases................... 768

gases from meteorites.................... 282

Graham, T., Miller, W. A., and Hofmann,

A. W., water of the Thames..... 93

Grahamite............................ 727,723,730

Gramann, A., alteration of andalusitc....... 406

Grandite.................................... 397

Grand River, analysis of water.............. 70

Grand Ronde River, analysis of water....... 85

Grand jean, , formation of dolomite...... 566

Grange, J., analyses of water.................. 94

Granite........................ 433,434,468,482,619

radioactivity of.......................... 309

sulphur waters from..................... 209

Granitito.................................... 433

Grant, U. S., zinc deposits................... 6S2

Graphite.............................. 322,323,762

Graphitic acid............................... 762

Graphitoid.................................. 762

Graton. L. C., tin deposits................. 348,693

See also Hess and Graton. 

Graton, L. C., and Murdoch, J., copper-iron

sulphides........................ 663

Grey, G., impurities in air................ 46,52,53

Greywackc................................ 538,539

Groat Salt Lake, analyses of water......... 153,170

Greaves, G. E., and Hirst, C. T., waters of

Utah............................ 153

Greenalite......................... 341,513,576,577

Greenlee, W. B., volume of ground water..... 34

GrecnocMte............................... 675-076

Greensand. See Glauconite.

Gregory, J. W., phosphate rock.............. 519

Greinacher, H., radioactivity................ 307

Greiner, E., silicate fusions.................. 301

Groisen...................................... 692

Greshoff, M., analysis by, cited.............. 192

Griffiths, A. P., mercury ores................ 675

Grimsley, G. P.,clays....................... 503

gypsum................................ 226,578

Griswold, L. S.,novaculite.................. 540

Groddock, A. von, sericitic rocks............. 596

topazfels................................. 405

Grossmann, M., gases from lava.............. 276

Grosspiotsch, O. Sec Redlich and Grosspietsch. 

Grossularite............................... 396-399

Groth, P., constitution of kyanite............ 405

Ground water, volume of.................... 34

Grout, IT. F., average composition of Minnesota rocks........................ 25

copper in country rock................... 661

magmatic differentiation................ 306

plasticity of clays........................ 497

precipitation of gold ..................... 652

of silver.............................. 657

Orubenmann, U., cyrstalline schists....... 591,592

glaucophane rocks..........'.............. 594

Griinsbcrg, K., carbonates of alkaline earths . 570 

Grunerite.................................... 379

Page. 

Griinerite-magnetite schist................. ^-.. 613

Griinling, F.,maucherite..................... 698

Griinlingite.................................. 095

Guano............................. 248,252,516,517

Guadalcazaritc.............................. 670

G uanajuatite................................ 695

Guarcschi, I., petroleum..................... 735

Gumbol, C. W. von, chloropito.............. 693

compression of lignite-................... 763

dolomite............................... 563,564

glauconitc............................. 512,513

itabirito................................. 612

origin of manganese nodules............. 131

Giinther, R. T., and Manley, J. J., water

analysis......................... 10G

Giinther, S., interior of earth................ 53

Giirich, G., ore deposits...................... 529

Gudrin, J. See Friedel end Gu<5rin.

G ueymard, E., platinum in tetrahedrite..... 710

Guignct, Enaction of nitric acid on coal..... 757

Guignet,C. E., waxfrompeat............... 742

Guitcrmamto................................ 6S4

Gulf of Mexico, analysis of water............ 122

Gully, E. See Baumann and Gully.

Gummito.................................... 715

Gunnarite................................... 698

Gunning, J. W., analyses of water........... 94,97

Gurlt, A., talc............................... 018

tungsten deposit......................... 706

Gnstaysen, C. N., analysis of water.......... 82

Guthrio, F., change of obsidian to pumice.... 292

cryohydratcs.............'............... 295

eutcctics............................... 296,419

Guyo, Kovacs, and Wourtzol, density of air.. 4-1 

Gypsum....... 218,223,224,226,242,246,250,535,578

Gyrolito..................................... 412

H. 

Habcrmann, J., formation of gypsum........ 578

Hackmannite................................ 309

Haofcko, H., constitution of hornblende..... 382

Haefele, P. E., alteration of andalusito....... <JOC>

Hagele, C. See Hell and Htigelo.

Haehnol, O., kaolinization................... 487

Haoussermann, F., and Naschold, W., coal

analyses......................... 761

Hager, L., salt deposits...................... 224

Hague, A., origin of Yellov/stone hot springs. . 207

scorodite in spring deposit............. 203, C95

Hahn, H., hydrocarbons in iron............. 730

Haldane, W. G. See Fleck and Haldano.

Hale, D. J.,marl............................ 549

Halite..................................... 219,242

See aZso Salt. 

Hall, A. A., oilsfromcoal.................... 750

Hall, A. D., and Miller, N.J.H., nitrogen in

rocks....!....................... 34

Hall, C. W., and Sardeson, F. W., dolomite . 560 

Hall, Sir J., artificial coal.................... 769

fusion of limestone....................... 555

Hall, R. D., and Lenher,V., tellurides.. 649,653,657 

Halley, E., age of ocean...................... 140

Hallock, W., effects of pressure.............. 655

Halloysite......................... 412,488,495,614

Hallstiitt, Lake of, analysis of water.......... 90

Halotrichite................................. 25t

Halse, E., mercury ores...................... . 670

tin deposits.............................. 692
796 INDEX.

rage. 

Hamberg, A.,cited.......................... 142

native lead.............'................. 683

Hamilton, N. D. Sec Parr and Hamilton. 

Hammerle, V., silicate fusions............... 300

Hammerschmidt, F., cited.................. 222

Hanamann, J., waters of Bohemia....... 98,99.100

Hancock, D. See Phillips and Hancock.

Hanks, H. G., California borates........... 238,240

Hanksite.................................... 242

Hannay, J. B., artificial diamond............ 318

occlusion of gases by glass................ 271

Hannayite................................... 517

Harder, E. C., iron bacteria.................. 528

manganese ores.......................... 533

Hardin, M. B., analysis by.................. 193

Hardman, E. T., analysis by................ 543

leaching of dolomite..................... 559

Sec also Hull and Hardman. 

Hardpan.................................... 479

Hardystonite................................ 678

Harger, H. S., diamonds..................... 321

Harker, A., average composition of igneous

rocks............................ 25

crystallization of magmas................ 290

hybridism............................... 303

magmatic differentiation................ 305

origin of pegmatite...................... 430

primary iolite........................... 402

quantitative classification of rocks....... 429

Harkins, W. D., evolution of elements....... 39

Harkness, R., dolomite...................... 567

Harmotome................................. 412

Harney Lake, analysis of water............ 159,172

Harper, H. W., asphalt...................... 730

Harpcrath, L., Argentine salt................ 225

petroleum and salt...................... 743

Harrington, B. J., analysis by............... 593

bomite.................................. 663

hydrogen sulphide in calcite........... 269,546

See also Adams and Harrington. 

Harrington, G. L. See Emmons and Harrington. 

Harris, G. D., salt deposits.................. 225

See also Call and Harris. 

Harris, J. E., absorption in soils............. 497

Harrison, J. B., bauxite..................... 491

gold in creek water...................... 650

gold in wood ashes....................... 650

heavy metals in rocks................... 632

laterite.................................. 489

rain water................................ 52,53

Harrison, J. B., and Jukes-Brown, A. J., coral

rock............................. 554

red clay................................. 509

Harrison, J. B., and Reid, R. D., waters of

British Guiana.................. 90

Harrison, J. B., and Williams, J., chlorides in

rain............................. 53

nitrogen compounds in rain.............. 52

Harrogate, analyses of waters................ 18Q

Hartite...................................... 727

Hartleb, R. See Stutzer and Hartleb.

Hartley, W. N., gases in rocks............... 269

reduction of sulphates................... 146

Hartley,W. N., and Ramage, H.,distribution 

of rare elements............. 28,527,653

Hartsalz..................................... 219

-Harzose ............:........- ............. 446,448

Hasselberg, B., absence of uranium from sun. 312 

Hasshagen, , water analysis............... 166

Hasslingcr, R. von, artificial diamond....... 318

Hasslinger, R. von, and Wolff, J., diamond.. 318 

Hastings, J. B., gold ores.................. 646,648

origin of pegmatite....................... 430

Hastingsite.................................. 382

Hatch, F. H., classification of igneous rocks.. 421 

diamonds................................ 320

Hatch, F. H., and Rastall, R. H., dedolomitization........................... 626

Hatchettite.................................. 727

Hauenschild, G., predazzite................. 572

Hauer, K. von, analysis of water............ 168

Hauke, M.,eutecties......................... 300

Hauynite.................................. 369,371

Haiiynophyre............................... 443

Haushofer, dolomite and magnesitc.......... 562

solubility of minerals.................... 473

Hausmann, J. See Zaloziecki and Hausmann. 

Hausmann, J. F. L., wulfcnite.............. 687

Hausmannite................................ 531

Hautefeuille, P., synthesis of cnstatite....... 372

syntheses of feldspars................... 361

of greenockite and wurtzite.......... 676

ofleucite............................ 364

of lithium-aluminum silicates........ 376

of nephelitc.......................... 367

of olivine............................ 386

ofperofskite......................... 344

of quartz and tridymite.............. 354

of rutilc, brookite, and anatase....... 346

titanite.............................. 345

vanadinite........................... 689

See also Troost and Hautefeuille. 

Hautefeuille, P., and Margottet, J., synthesis

of quartz and tridymite.......... 354

synthesis of staurolite (?)................ -407

Hautefeuille, P., and Perrcy, A., crystallization oftitanic oxide.............. 346

synthesis of beryl........................ 410

of corundum......................... 332

of zircon............................. 349

Hautefeuille, P., and Saint-Gillcs, L. P. de,

synthesis of mica................ 390

Hawes, G. W., alteration of granite.......... 619

analyses by............................ 619,750

chloritization.. ........................... 603

native iron....'.......................... 324

Hawcs, G. W., and Wright, A. W., gases in

quartz........................... 269

Hawkins, J. D. See lies and Hawkins. 

Haworth, E., petroleum................... 725,743

zinc deposits............................. 682

Haworth, E., and Bennctt, J., native copper. 662 

Hayes, A. A., distribution of vanadium..... 712

sodium iodate in Chilean niter......... 244,250

South American borates................. 244

Hayes, C. W., alunogen deposits............. 254

bauxite................................ 492,493

corrosion of quartz..................... 358,476

iron ores................................. 529

phosphatic sandstones.................. 537

phosphorite............................. 523

Hayes,C. W.,and Eckel, E.G.,iron ores.... 529

Hayes, C. W.,and Kennedy, W., salt deposits 229 

Texas petroleum........................ 725

Hayes.C. W.,and Ulrich, E. 0.,phosphorite. 523
INDEX. 797

Page. 

Haycs .River, analysis of water.............. 88

Hayhurst, W., and Pring, J. W., ozone in

atmosphere...................... 44

Hay wood, J. K., analysis by................ 100

Haywood, J. K., and Sirijith, B. H., analyses

cited.......................... 182,101

Headden, W. P.,action of water on orthoclasc 476 

alunogen................................ 254

analyses o* river waters......... 61,62,66,67,82

anthraei te ............................... 761

baryticsinter.......................... 199,582

carbonate waters......................... 186

cubanite............................ '.... 663

natron................................... 237

nitiates in soil.......................... 248

stannite................................. 690

Heath, G. L.,cited.......................... 70

Heazlewoodite............................... 698

Hcbcrdcy, P.,melilitcandgehleniteinslags.. 395 

wollastonite in slags..................... 373

Hedburg, E., zinc deposits.................. 682

Hcddlc, M. F., analysis by.................. 514

Hedenbcrgite.............................. 374,378

Hedrumite.................................. 441

Hcidcr, A., analysis by...................... 166

Heilcman, W. H., water analyses............ 83

Hein, H., fibrous silica....................... 352

Hcinisch, W., graphite in soils............... 323

Hcintzite.................................. 220,245

Helium, distribution.................... 16,42,218

generation from radium........... 311,715,726

infumarole gases-..................... 256,262

in natural gas........................... 722

in spring waters....................... 176,312

Hell, C., flchtelite........................... 753

Hell, C., and Hagele, C., artificial paraffin..... 722

Hclmhaclccr, R., chromite deposits.......... 704

Helvite...................................... 209

Hematite.......................... 265,287,342,343

Hempcl, W,,melting points of minerals. 286,287,332 

oxygen of the atmosphere............... 43

volcanic gases........................... 262

Hcnrich, F.; cited......................... 208,475

volcanic sublimates..................... 265

Henrict, H., formaldehyde in atmosphere... 46 

Henrict and Bonyssy, ozone................. 44

Henriot, E.,radioactivity................... 311

Henriot, E., and Varon, G., radioactivity.. - 311 

Hcnwood, W. J., electrical activity in ore

bodies........................... 644

Heraeus, W. C., melting points of shales and

clays............................ 286

Hcrapath, T. J., and W., the Dead Sea...... 165

Hcrbst", C., ocean water...................... 122

Hcrcynite................................. 336,337

Hcrdcrite................................... 410

Heron Lake, anal ysis of water............... 77

Hcronitc.................................. 366,444

Hess, F. L.,camotite....................... 717

magnesite............................... 573

tungsten deposits....................... 707

vanadium deposits...................... 716

Hess, F. L., and Graton, L.C., distribution of

tin.............................. 690

Hess, F, L., and Schaller, W. T., vanadium

minerals......................... 717

See also Watson and Hess.

Page. 

Hess, V. F. See Schweidler and Hess.

Hess, W. H., cave nitrates.................. 248

Hessitc...................................... 657

Hessosc................................... 450,452

Heterogenlto................................ 701

Heubachite................................. 701

Hculandite........;......................... 412

Heumite.................................... 441

Heuslcr, F., formation of hydrocarbons...... 739

Heusser, C., and Claraz, G., Brazilian diamonds .......................... 321

Hcwett, D.F.,sulphurin Wyoming......... 579

vanadium ores.......................... 713

Hewettite................................... 714

Heycock, C. T., and Neville, F. H., silver

antimonide...................... 654

Heyward, B. H., tallow clays............... 681

Hezncr, L., amphibolite..................... 595

eclogito.................................. C02

Hibsch, J. E., primary zeolites.............. 412

Hibschite................................... 408

Hicks, H., phosphatic fossils................. 521

Hicks, W. B., analyses by................... 158

Hidden, W. E., Llano County minerals..... 720

sperrylite................................ 711

xenotime ingranite..................... 351

See also Judd and Hidden. 

Hidden, W. E., and Mackintosh, J. B.,

gadolinite, etc................... 720

Hidden, W. E., and Pratt, .T. H., sperrylite... 711 

Hidden, W. E., and Warren, C. H., yttrocrasite........................... 720

Hiddenite................................... 375

Hicratitc.............. ...................... 265

Highwood River, analysis of water.......... 88

Highwoodose................................ 435

Hikutaia Spring, analysis................... 186

Hilgard, E. W., analyses by........ 83,158,232,486

arid and humid soils compared.......... 486

carbonates as sol vents of silica........... 478

disintegration of rocks................... 485

origin of alkaline carbonates in soil. 205,236,237 

soils..................................... 503

Hilger, A., analysis of holothurian........... 564

Hill, B. F., Terlinguamines................. 671

Hill, J. B., and MacAlister, D. A., Cornish tin

ores............................. 691

Hill, J. M. See Bastin and Hill.

Hill, R. T., salt deposits..................... 224

Terlingjia mines......................... 671

Texas petroleum........................ 725

Hillebrand, Sylvia, nephelite................ 367

Hillcbrand, W. F., analyses by.............. 184,

185,186,377,431,432,433,434,435,437,438, 

440,442,444,446,448,450,451,452,454,456, 

457,459,460,462,504,510,532,544,546,571, 

575,595,617,618,622,627,636,649,715,716 

copper arsenatcs......................... 668

distribution of vanadium................ 712

heavy metals in rocks................... 631

kleinitc.................................. 671

patronitc-................................ 713

quisqucite............................... 713

rare-earth minerals...................... 720

roscoelite................................ 714

slate..................................... 545

zinc-bearing clay..............'.......... 681

See also Cross and Hillebrand.
INDEX.

Page.

Hillebrand, W. F., Mcrwin, H. -E., and 

W-right, F. F,., vanadium minerals.. .....................,...... 714, '717

Hillebrand, W. F,, and Ransome, F. L.,

camotitc........................ 716

JHillebiand, W. F.., and Schallcr, W. T,,,

Tcrlingua minerals.............. 671

See aZso-Schaller and Hillebrand. 

Hfllebrand, W. F,,:and'Scherrer, J. A.,-gallium.............................. 1575

Himmelbauor, A., scapolite. ................... 400

Himstedt, F., radioactivity.................. 308

Hinde, G. J., flint andxihert,................. 541

.Hinden, F., dolomite and limestone......... -563

Hinsdalite.................................... '689

Hiortdahl, T..,.synthesis of jaipurite......... 699

-HiortdahUte.................................. 378

Hirschvv aid, J., nitrogen compounds in rain.. .52 

Hirst, C. T, See Greaves and Hirst.

Hitchcock, C, H.,.albertite-................... 728

phosphate rock................................ 517

steatite.................................... COS

Hobbs, W, H., allanite and epidote.......... 404 ;

secondary galena..................... . 684

tungsten deposit-........................ 706

Hodge, E. T., mine waters...._....,......... 635

Hodges, J. F.., watet,snalysis............. ... S3 ',

Hodges, R. S^.cited.......................... 75

Hodgkinsonite............................... 678 , Hogboni, A. G., cited by Arrhenius.......... 49 ,

dolomitization..............__....... 504-566 .

Hoernes, R. -See noeltcr.and Hocrnes.

Hoff. .See Van't Hoff.

Hoffman, E, J. ./SeeiFrazer and Hoffman.

Hoffman, L.,iron ores....................... 577

Hoffmann, E.. W_, solubility of minerals..... 474

Hoffmann, G. C,, allanite in rgranite.......... 404 I

analysisby,cited............................ 177 ,

baddeckite......,....----.....-...-.--.,.. 387 j

nativeiron................................... 327 ;

native platinum......................... 708 

souesitc.................................. 326 :

'Hoffmann, R., synthesis of ncphclite........ 368 '

Hofman, H. O., -eutccties in slags............ "298

Hofmann, J. F., formation ol coal.......... 746,771

Hofmann-Bang, 0., rivers of Sweden...... 102,103

.Hoitsema, S. See Bemmelen, J. M., van, etc. 

Holland, P., and Dlckson, E., decomposition

of diabase................. v..... 483

Holland, T.H.,bauxite..................... 493 ,

corundum rock.......................... 334

desertsalts..........:......-.......-.... 230

 disintegration of rocks................... 477,483 |

graphite in syenite...................... 32g ;

latcritc................................... 488 '

primary calcitc.......................... 414

quartz-baritorook....................... 584

serpentine............................... 605 

Holland, T. H., and Christie, W. A. K,, the

Sambhar-salt lake............... 148

Hollandite.................................. 532

Hollick, A. See Kemp -and Hollick.

Page. 

Holmes, A., ago of car-th...................... 314

classification-:ol igneous -rooks ........... 419

distribution of radium...................... 310

laterite.................................. 4S9

radioactivity................._............ 311

Holmes, A., and Lawson, R. W.,age jof min-

 crals-............................... 314

Holmes, H. N., ozone in atmosphere. ..... 44

Holmes, J. A., peat............................ 753

.Holmium..................................... 16

Holmquist, P. J., cristobalite and tridymitc. 354

synthesis of perofskite... . ..._,..,.. 345

Holmquistite................................ 383

.'Holothurian, analysis of...................... 504

Holtz, H. C. See Duparc and Holtz.

Holway, R. S., cclogitc...................... 602

 Hood,, , analysis by.......................... 702

H-opeito....................................... 678

Hopkins, A. T.., chlorine maps ............. 53

 Hopkins, T. C., limestones.................. 556

Hopmann, H., water analysis.-._.......... Ifi9

ETroppc-Seylcr, F., formation of raarsh.gas.... 737

:synthosis of dolomite...................... £60

Hornblende....................... 268,287,380-383

Hornblenditc................................ 458

Horner, L., silt............................... 500

Hornstcin, F. F., native iron... .............. 324

Hornung, F., origin of petroleum............ 739

Hornung, M., analysis of red mud........... .510

Hornung, T. See Duparc and Hornung.

Horowitz, J. See Dunin-Wasowicz.

. Horsford, E. W., cited........................ 71

Horsforditc.................................... 663

Horton, F. W., molybdenum............... 705

Hortonolitc.................................... 385

Horwood, A, R.., calcite and aragonite in

fossils............................... 551

Hoskins, A. P., glauconite................. 513,514

Hovey, E. O.., artesian well at Key West.... 509

 cordierite gneiss. . ... ............. 402

siliceous oolite....-._............._...... 542

 How, H., berates of Nova Scotia........:...... 245

 Howard, C. C., natural gas...... .......... .723

.Howard, C. D., analyses by... ............ 79,722

Howo, E., magmatic sulphides.. ........ 330

Howe, J. L., and Campbell, H. D,7 on Chichcn-Kanab....................... 161

 Howlite............................................ .245

Huacachinia, .Lake, .anal ysis of water....... 1G1,173

Huantajayite................................... 660

Hubbard, P. 'See Cushman and Hubbard. 

Hubnerite................................. 705,706

Hudleston, W. H., phosphatic fossOs........ 521

Hudson, E. J. See Mabery and Hudson. 

'Hiittner, K., gases in rocks.................. 273

Hudson River/analyscs of .water........._.. 72

Hughes, G., phosphate rock................. 517

Hull, E., cited............................... .93

Hull, 13., and'Hardman, E. T,, chert...... 540,541

.Hulsite.................................... 690,693

Humboldt and G ay-Lussac, cited........... 51

Humboldt La"kc, analysis of water......... 157,172

Humboldfc River, analysis ol water........... 157
INDEX. 799

Page. 

Humboldt salt well, analysis................ 178

Humboldtinc............................... 749

Hume, W. F., loess.........................'. 505

nitrate shales. -.......................... 248

Humphreys, A. A., and Abbot, H. L., sediment of Mississippi River........ 501

Humphreys, W. J., gases in atmosphere..... 44

rare earths in fluoritc.................... 331

volcanic dust and climate................ 50

Humus acids.................. 103,205,479,756,758

Hundcshagen, L., platinum in \vollastonite-. 710 

Hungary, salt and warm lakes of...... 168,169,170

Hunt, A. E., bauxite........................ 492

Hunt, T. S., abundance of petroleum....:... 744

alteration of siderite..................... 574

analyses by......................... 69,181,193

cosmical atmosphere..................... 55

formation of dolomite................. 558,563

on atmospheric carbon dioxide.......... 43

origin of alkaline carbonates............. 235

primeval ocean.......................... 133

salt and gypsum........................ 224

sedimentation........................... '502

serpentine............................... 607

See also Logan and Hunt. 

Hunt, W. F., origin of Sicilian sulphur....... 579

See also Kraus and Hunt. 

Hunter, J. F. See Larscn and Hunter. 

Hunter, M., analysis by..................... 444

Hunter, M., and Rosenbusch, Hi, monchiquitc............................ 444

Huntilitc..................................... 654

Hurlbut, E. B.,analysis by.................. 442

Huron, Lake, analysis of water............... .70

Hurst, L. F. See Cameron and Hurst.

Hussak, E., associates of diamond............ 321

chalmersito.............................. 663

leucite pscudomorphs.................... 366

nativeiron..... -..................:...... 324

palladium gold......................... 648,710

perofskite-magnetite rock-............... 345

platinum and palladium................. 70S

primary iolitc-........................... 402

synthesis of wollastonito................. 373

See also Dooltcr and Hussak. 

Hussak, E., and Prior, G. T., derbylito, etc.. 697 

Hussak, E., and Rcitinger, J., monazitc sand 351 

Hutchings, W. M., apatite in slag.... i........ 350

clays and shales.......................... 545

minerals in sand.......................... 498

ottrclite.................................. 616

willemitc in slag............................ 679

Hutchinson, , cited..................... 52

Hutchinson, A., Mcigen's reaction........... 550

See also Cundcll and Hutchinson. 

Hutchinson, brine,analysis of................ 178

Button, R. S. See Pring and Hutton.

Hyalife......................................... 352

Hyalophanc...................................... 359

Hyalosiderite................................ 385

Hyalotekite.................................. 689

Hydrargillito. See Gibbsite.

Hydroboracltc............................. 220,245

Hydrocarbons.............................. 721-745

in lava................................ 276,735

Bydrooerusite.. ......................... 685,688

Hydrogen, distribution....................... 17

in atmosphere............................ 45

Hydrogen dioxide in atmosphere............. 44

Hydrogoethite............................... 527

Hydroids.................................... 565

Hydromagnesitc............................ 411,572

Hydroncphclite.............................. 412

Hydrozincitc................................. 678

Hypersthene............................... 371,378

I.

Iceland, analysis of geyser water from........ 190

slater from............................... 202

volcanic gases from....................... 256

Iddings, J. P., consanguinity of rocks. ...... 301,302

fayalitc in rhyolitc............'........... 386

magmatic differentiation............... 292,302

order of igneous eruptions................ 304

quartz basalt............................. 357

rock diagrams............................ 470

See also Tiarus and Iddings. 

Iddings, J. P., and Cross, \V., primary allanito.............................-: 404

Iddings, J. P., and Penfield, S. L., fayalite in

rhyolitc.......................... 380

Idocrasc. See Vesuvianitc.

Idrialite...................................... 674

Igelstrom, L. J., molybdenum in hematite... 3-13 

Igneous rocks.............................. 415-470

average composition...................... 26

classification of......................... 416-429

Ihlseng, M. C., phosphate rock............... 526

Ijolite........................................ 440

lies, M. W., and Hawluns, J. D., precipitated

zinc sulphide..................... 677

Iletsk salt lake, analysis of water...:....... 168,170

Illiacus, A. See Ramsay and Illiacus.

Illinois River, analysis of water.............. 78

chlorine in................................ 108

Illyes Lake, analysis of water.......... 168,169,170

Ilmenite................................... 343,344

Ilmcnite-nclsonitc............................ 463

Ilmenito norite............................... 462

Ilscmannitc............................... 635,704

Ilosvay, L. von, water analysis............... 102

Hz, River, analysis of water.................. 101

Imperial, Pennsylvania, analysis of brine.... 181

Indalself, analysis of water................... 103

Indian Ocean................................ 122

Indium, distribution....................... 17,675

Infusorial earth.............................. 543

Ingalls, W. R., tin deposits.................. C92

Logol, Lake.................................. 103

.Inn, River, analysis of water................. 101

Inostranzoff, A., native iron.................. .327

native platinum.......................... 709

schungite................................ 762

d'lnvilliers, E. V., phosphate rock........... 517

Iodine, distribution........................... 17

in sea water.............................. 118

inspring water........................... 179

lodobromitc................................. 660

lodyrite.._................................. 660

Iolitc....................................... 401,402

Ionian Sea................................... 121

Ionium...................................... 308
800 INDEX.

Page. 

Iowa River, analysis of water................ 78

Ipatief, W., origin of petroleum.............. 739

Ippen, J. A., amphibolitc.................... 595

eclogite.............................'..... 601

synthesis of cinnabar...................... 672

Iridium............................. 17,328,707,709

Iridosrhine................................. 707,709

Iiish Sea, analysis of water................... 122

Iron, distribution............................ 17

hydroxides of.......................... 526-530

in sea water.............................. 120

meteoric, chlorides in.................... 138

native.................................. 323,327

nitride.................................. 266,267

occlusion of gases by..................... 282

Iron bacteria.................... ........... 528

Iron ore............................ 526-530,573-578

titaniferous.............................. 462

Irvino, R. See Murray, Sir J.

Irvine, R., and Anderson, W. S., phosphatization............................ £57

Irvine, R., and Gibson, J., manganese nodules.............................. 131

Irvine, R., and Young, G., solubility of calcium carbonate................. 126

Irving, J. D., tin deposits.................... 693

Irving, J. D., and Emmons, S. F., tungsten

ores.............................. 706

Irving, R. D., native copper................. 661

quartzite................................... 010

Irving, R. D., and Van Hise, C. R.,

chert ........................... 542

enlargement of quartz grains............. 536

Isar River, analysis of water................. 101

Iser River, analyses of water................. 99

Isere, River, analysis of water............... 94

Isochlors.................................... 53,147

Isotopes..................................... 313

Issyk-Kul, analysis of water............... 168,172

Istrati, C. I., Roumanian salt................ 225

Itabirite.................................. 612, 710

Itacolumite.................................. 321

J. 

Jaccard, A., origin of petroleum.............. 743

Jackman, W. F.,cited....................... 70

Jackson, D. D.,cited........................ 53

J acobsen, 0., analyses of dissolved air....... 140

analysis of peat.......................... 751

resins in peat............................ 753

Jacquot, E., and AVillm, E., mineral

springs........................ 205,211

Jaczewski, L., origin of graphite............. 323

Jadeite...................................... 375

Jaeger, F. M., analysis by................... 530

Jaeger, F. M., and Sirnek, A., synthesis of

spodumene...................... 376

Jaeger, F. M., and Van Klooster, H. S., syntheses of sulphides............. 659,685

Jaenecke, E., oceanic salts................. 216,219

Jaffa, M. E., alkaline carbonates,............ 236

JafTe, R., pitchblende........................ 714

Jaggar, T. A., temperature of lava........... 277

Jaggar, T. A., and Palache, C., zoisite rock...' 598 

Jahn, J. J., origin of petroleum............... 739

Jaipurite.................................... 698

Page. 

James River, analyses of water.............. 73

Jamesonite.....................;............ 684

Jamieson, G. S., nickel-irons................. 326

See also Penfield and Jamieson. 

Jamieson, G. S., and Bingham, H., analysis of

water............................ 161

Janda, , uranium ores.................... 714

Janeirose.................................... 442

Jannasch, P., and Calb, G., composition of

tourmaline..;................... 409

Jannasch, P., and Weingarten, P., vesuvianite............................ 399

Jannetaz, E., formation of anglesite.......... 686

Janssen, J., volcanic gases................... 263

Jaquerod, A., and Perrot, F. L., helium-.-.. 312 

Jaquet, J. B., platinum in ironstone........ 710

serpentine............................. 411,606

Jarman, J. L., analysis by................... 532

Jasper....................................... 352

Jaspilite .......^............................ 612

Java, rivers of............................... 104

Jefrersonite................................ 374,678

Jeffrey, B.C., origin of petroleum and coal... 741

748,760 

Jenkins, 0. P., epsomite lakes............... 237

Jenkins, , analysis by ................... 532

Jenney, W. P., artificial grahamite.......... 728

recent blende............................ 677

zinc deposits............................. 682

Jennings, E. P.,magmaticiron ores......... 341

Jensch, E., cadmium........................ 675

Jensen, H. I., copper in andesite............. 632

origin of alkaline rocks................... 441

Jentzsch, A., German lakes.................. 102

Jerden, D. S. See Bone and Jerden.

Jereme'ef, P., chalcopyrite and chalcocite..... 665

, pseudomorphous garnet................. 399

pseudomorphs after olivine.............. 386

Jems, W. P., Tuscan fumaroles............. 246

Jet........................................ 754,766

Joannis, A., fusion of limestone.............. 555

Jockamowitz, A., borax..................... 244

Jodidi, S. L., organic matter of soils.......... 106

Johannsen, A., classification of igneous rocks. 470

planimeter method...................... 470

Johannsen, A., and Stephenson, E, A., the

Rosiwal method ................ 470

Johansson, H; E., eutectics................ 296,419

John, C. von, humus acid in coal............ 756

kainite and carnallite.................... 222

Nile mud................................ 500

John, W. von, native tantalum.............. 718

John Day River, analysis of water........... 85

Johns, C., transition point of quartz......... 355

Johnson, B. H., and Warren, C. H., cumberlandite.......................... 463

Johnson, B. L., chalmersite.................. 663

Johnson, H. S.,cited........................ 101

Johnson, J. P., diamond..................... 320

Johnson, L. C., Florida phosphates.......... 517

Johnston, J., high pressure investigations ... 588

See also Alien and Johnston. 

Johnston, J., and Adams, L. H., effects of

pressure ...................... 588,655

Jobnston, J., Merwin, H. E.,and Williamson,

E. D., calcium carbonate........ 550
INDEX. 801

Page.

Johnston, J., and Niggli, P., metamorphism. 5S6 

Jchnston, J., and Williarnson, E. IX, carbonates in sea water................. 127

solubility of calcite.................... 127,547

Johnston, R. A. A., analyses by........... 327,339

awaruito................................ 320

Johnston-Lavis, H. J., absorption of rocks by

magmas......................... 303

quartz in basalt.......................... 293

Vesuvian sublimates..................... 265

Jolmstone, A., action of water on micas ..... 392

solubility of minerals.................. 130,474

Johnstrup, F., cryolite....................... 331

Joly, J., age of the earth................... 13S, 147

age of minerals......................... 311,315

meldometer.............................. 2S6

melting point of minerals................ 2S7

order of deposition cf minerals........... 300

radium and geology...................... 80S

radium in rocks.......................... 369

radium in sea water................... 121,308

radioactivity and volcanism............. 310

sedimentation........................... 502

sublimation of enstatite.................. 268

volume of oceanic salts.................. 24

volume of oceanic sediments............. 136

Joly, J., and Flctcher, A. L., pleochroic halos. 315 

Joly, J., and Kutherford, E., pleochroic halos. 315 

Jones, D. T., and Wheeler, R. V., constitution

of coal............ ............. 773

Jones, E. J., barite modules .................. 134

Jones, L. J. W., mine water................. 630

Jones, T. R., chert..................:....... 540

peat................:.................... 751

Jones, W. R., cited.......................... 201

tin in Malaya............................ 692

Jonesvillc acid water, analysis............... 193

Jordan River, analysis of water.............. 161

Jordan River (Utah), analysis of water...... 154

Jordanite..................................... 684

Jorissen, A., vanadium in delvauxite........ 712

Joseite-...................................... 695

Josepliinite................................ 326,698

Joukowsky, E., eclogite..................... 602

Jourdy, E., dolomitization.................. 570

Jovitschitsch, M. Z., chrornitite.............. 339

Jowa, L., synthesis of selenitc............. 224,578

Juday, C'. See Birgo and Juday.

Judd, J. W., alteration ofplagioclasctoscapclitc............................ 363,599

atoll of Funafuti......................... 567

corundum rock.......................... 334

origin of scapolite........................ 400

pressure and chemical change............ 285

scapolite rock............................ 334

Judd, J. W., and Brown, C. R., Burmese corundum ......................... 334

Judd, J. W., and Hidden, W. E., ruby...... 335

Judge, J. F.,and Fennel, A. C., analysis by... 179 

Judi those.................................... 438

Jukes Brown, A. J. See Harrison and Jukes 

Brown.

113750° 20 51

Page. 

Julicn, A. A.,alteration ofspodumenc....... 375

decomposition of pyiitc.................. 330

geological effects of humus acids......... 106,

205,479,542 

phosphate rock.......................... 517

talc and serpentine...................... 608

Juvenile waters............................ 207,208

K. 

Kaersutite................................... 384

Kahlcnberg, L., and Lincoln, A. T., hydrolysis of silicates.................... 189

Kahlenberg, L., and Schreiner, 0., boratc

ions............................. 191

Kainite...................................... 218

Kaiser, E., African diamonds................ 320

alteration of basalt...................... 495

decomposition of rocks.................. 482

Kaiser, 0. Sec Pictet ct al.

Kalamazoo River, analysis of water......... 70

Kalcczinzky, A., water analysis........... 16S, 169

Kalgoorlite.................................. 649

Kaliophilite............................... 367,368

Kalkowsky, E., corundum granulitc......... 334

Kallerudose................................. 433

Kallilite..................................... 698

Kalmann, W., and Glaser, M., analysis by.. 180,184 

Kanab Creek, analysis of water from near.... 181

Kanolt.C. W., melting points of oxides.... 287,332

Kansas River, analysis of water............. 81

Kaolin.................................... 486,487

Kaolinite.......................... 411,412,486,6M

Kapouran, analysis of water................. 181

Karabot'haz, Gulf............. 162-163,172,216,228

Karlsbrunn, analysis of water from.......... 186

Karlsd orf waters, analysis.................. 182

Karstens, K., volume of the ocean........... 22

Kasarnowski, H. See Wo'hlcr and Kasarnowski. 

Kaskaskia River, analysis of water.......... 78

Kastlc, J. H., Frazcr, J. C. W., and Sullivan,

C., phosphatic chert............. 542

Katamorphisrn, zone of.................... 587,589

Katwec salt lake, analysis of water........ 109,173

Katzer, F., analyses of Amazon water....... 91

analyses of sea water cited............... 121

mercury deposits........................ 674

Kaucr, A., analysis by...................... 183

Kaufmann, F. C., dopplerite................ 753

Kay, G. F., nickel ores...................... 701

Kayser, E., carbon dioxide and climate...... 19,50

Kayscr, R., sulphur in petroleum........... 726

Kedabekase................................. 457

Kehoeite.................................... 678

Keith, A., zinc deposits..................... 682

Kellcr, G., formation of limonite............ 574

Keller, H. F., and Lane, A. C., chloritoid.... 388

Keller, O., volume of ground water.......... 34

Kellermann, K. F., and Smith, W. R., bacterial precipitation of calcium carbonate .......................... 547

Kelly, A.,conchitc.......................... 550
802 INDEX.

Page. 

Kelscy,H.G., cited......................... S3

Kelvin, Lord, effect of pressure on fusibility.. 285 

primitive atmosphere.................... 50

Kelyphite................................... 399

Kemp, J. F., bornito in pegmatite..... 331,665,666

Franklin zinc ores....................... 682

gneiss defined.......................'.... 621

gravitative differentiation in magmas.. 305,306 

ground water............................. 3-1

iron ores............................... 464,529

magmatic magnetite..................... 341

metamorphosed dolomite................ 626

molybdenite in pegmatite............... 330

nickel ores............................... 700

. ore deposits............................. 629

platinum ores............. 328,707,709,710,711

relative abundance of elements.......... 28

secondary enrichment................... 643

tollurides................................. 649

Kemp, J. F., and Hollick, A.,limestone..... 626

Kempton, C. W., tin deposits................ 692

Kendall, J., solubility of calcium carbonate.. 127 

Kcndall, P. F., calcite and a'ragonite in shells. 551 

Kennedy, W, See Hayes and Kennedy. 

Kennedy, W. T. See McLennan and Kennedy.

Kenngott, A., alkaline reaction of minerals... 473 

composition of tourmaline............... 409

vesuvianite.............................. 399

Kendrick, F. B. See \7an't Hoff, Kendrick,

and Dawson. 

Kentallenose.............................. 450,451

Kentrolite................................... C89

Kentucky Eiver, analysis of water.......... 79

Kermesite................................. 695,696

Kern-theorie................................ 421

Kerner, G., water analysis .................. 98

Kerosene shale.............................. 741

Kcrr, W. C., marl........................... 549

Kcrsantite................................ 436,451

Kettner; C. H., analysis by.................. 530

Koyes, C. K., borax deposits................ 240

genesis load and zinc ores ............... 682

gypsum................................. 578

linnaeite................................. 700

loess..................................... 505

ore deposits............................. 629

origin of cerargyritc...................... C60

primary epidote......................... 403

recent blende............................ 677

ultimate source of ores................... 630

Kieserite......................^............. 218

Kikuchi, , occurrence of iolite............ 402

Kilauea, gases from.......................... 260

Kilbrickenitc................................ 684

Kilroc, J. R., laterite and bauxite........... 489

Kimball, J. P., grahamite................... 728

iron ores............................... 529,574

Kimberlite.................................. 320

Kinahan, G. H.,bauxite.................... 492

Kinch, E., sodium chloride in rain.......... 53

King, C., internal temperature of the earth... 285 

King, F. P., Georgia corundum............. 335

Kingsbury, J. T., waters of Utah............ 153

Kirk, M. P., and Malcolmson, J. W., Terlingua minerals.................. 671

Kirunose..........................._...... 464

Kisil-Kul, analysis of water................ 167,171

saline deposits........................... 228

Kispatic, M., bauxite........................ 494

Kitchell, \Y., marl.......................... 548

Kitchin, E. S., and Winterson, W. G., argon

and helium in minerals.......... 269

Klaprotholitc...................'............. 667

Klarelf, analysis of water.................... 103

IQarfeld, H. See Zaloziecki and Klarfeld. 

Kleinite................................... 670,671

Klernent, C., analyses by.............. 132,133,617

formation of dolomite.............. 560,563,566

laterite.................................. 489

origin of petroleum...................... 738

Klementito.................................. 392

Klemm, G., minerals in sandstone........... 538

Klobbie, E. A., analysis by.................. 530

See also Bemmelen, J. M. van, etc. 

Knebelite................................... 385

Knight, C. W., analcite trachyte............ 366

See also Campbell and Knight. 

Knight, H. G., water analyses.............. 86,160

Knight; "W. C., platinum in corellite........ 711

Knisely, A. L., water analyses.............. 86

Knop, A., enlargement of quartz grains...... 536

Knopf, A., andalusite rock................ 406,616

average composition of rocks ............ 25

dumortierite rock....................... 408

platinum and palladium ................ 711

silver halides............................ 660

strontianite.............................. 582

tin deposits............................ 692,693

Kuopf, A., and Schaller, W. T., hulsite and

paigeite.......................... 690

Knox, J., mercury sodium sulphide......... 673

Knox, W. J.,impurities in rain.............. 51

Knoxvillite................................. 703

Kobellite.................................... 684

Koch, A., celcstite and barite................ 581

cited.................................... 344

Kochelsee, analysis of water................. 96

Kodurite..".................................. 398

Kobrich, bauxite........................... 491

Koechlinite................................. 704

Ko'hler, H., asphalt.......................... 730

Koehlichen, K,,cited........................ 218

Koehn, E.,cited............................ 101

Koenc, C. J., primitive atmosphere.......... 56

Koenenite................................... 220

Koenig, A., genesis of diamond.............. 322

Koenig, G. A., analysis cited................ 181

synthesis of domeykite.................. 663

Koenig, G. A., and Foote, A. E., diamonds

in meteorite..................... 319

Konig, T.,and Pfordten, 0. von dcr, ilmenite. 344 

Koenigsbcrger, J., radioacitivity............. 311

temperature relations.................... 289

Ko'nigsberger, J., and Miillcr, W. J., synthesis of quartz and tridymite... 353 

Konigsee, analysis of water................. 96

Konlite...................................... 727

Kottigite.................................... 678

Koettstorfer, J., iodine in sea water.......... 118

Kohlmann, W., associates of cassiteritc...... 348

Kohlrausch, F., hydrolysis of silicates....... 189
INDEX. 803

Page. 

Kohlschiitter, V., and Eydmann, E., hair

silver............................ C53

Koken, E., carbon dioxide and climate...... 50

Koko-Nor, analysis of water............... 160,173

Kolenko, B., hornblende pseudomorphs... 381,387 

Koldcrup, C. F., analysis by................ 402

Kolkwitz, E., and Ehrlich. F., on tho Elbe.. 08 

Kolotofl, S., analysis of sea water............ 122

Koninck, L. L. de, synthesis of cinnabar..... C73

KonincMto................................ 510,672

Kornerupinc.......................... 377,014-610

Kosmann, H. B., silver halidcs.............. 600

Koto, B., chloritoid rock.................... 010

glaucophane rocks....................... 594

picdmontitc............................. 403

Kovacs. StfeGuyectal.

KovaF, J., kyani to in limestone.............. ' 406

Kriimor, G., and Bottcher, "W., origin of petroleum. ........................ 738

Kramer, G., and Spilker, A., origin of petroleum......................... 742

ICragorite.................................... 464

Kraus, 'E. H., celestite....................... 581

Kraus, E. H., and Goldsberry, P., copperiron sulphides................... 663

Kraus, E. H., and Hunt, W. F., celestite.... 581

Kraut, K., diffusion of cobalt and nickel.... 698

Krazc, K., Stassfurt salts.................... 218

Krcmcrsite.................................. 265

Krennorito................................. 649

Krctschmer, A., composition of fahlcrz...... 667

ICrouslor, U., oxygen of tho atmosphere...... 43

Krcutz, S., amphibole....................... 382

the Meigcnreaction...................... 550

Krogh, A., annual consumption of coal...... 47

oceanic carbonic acid.................... 141

air from Greenland...................... 47

Ivriimmel, 0., volume of the ocean.......... 22,24

Kruft, L., phosphorite....................... 520

Krugitc..................................... 218

Krusch, P., platinum in graywacko......... 711

Krypton................................ 17,42,176

Kryptotile................................ 389,614

Ktypcite.................................... 550

Kiimmcl, H. B.,clays....................... 503

peat..................................... 751

Kuhlinann, F., phosphate rock.............. 520

silication of limestone.................... 557

synthesis of ccrargyrite.................. 660

Kulaite. ...................................... 454

Kultascheff, N. V., fusion of mixed silicates. 294,296 

Kunz, G. F., Montana corundum........... 335

Kunz, G. F., and Washington, H. S., Arkansas diamonds.................... 321

Kunzitc................................... 375,376

Kupffcr, A. E., native iron.................. 327

Kumakoff.N. S., on Karaboghaz............. 162

Kurtz, C. M., analyses by................... 238

Kusnetsoff, S., on Karaboghaz.............. 162

Kuss, H., mercury deposits.................. 674

Kvassay, E. von, origin of alkaline carbonates. 236 

Kyanitc........................... 405-407,614,015

Kyanito schist............................... 617

Kyle, J. J., Argentine boratcs................ 244

vanadium in lignite......;............... 713

watev analyses........................... 92

Page. 

Kyschtymase............................... 462

Kyschtymite.............................. 334,462

Laabitter spring, analysis................... 183

Laach, Late, analysis of water............ 168,172

Labordc, A. See Curie and Laborde. 

Labradorite....................... 287,359,360,363

Laby, T. H. See Mawson and Laby.

Lachat, , celestite....................... 581

Lachaud and Lcpicrrc, lead chromatcs...... C88

Lachmann, R.,later!te...................... 491

Lacroix, A., absorption of limestone by

granite................'... 1..... 303

allanite and epidotc..................... 404

alteration of bronze................ 663,668,686

alteration ol hornblende to augitc........ 381

alteration of serpentine................ 411,607

amphiboiitc............................. 599

berthicrinc.......'...................... 577

boric acid in fumarolcs.................. 239

chalcocite on old coins................... 603

constitution of phosphorite.............. 519

dumorticrito in gneiss................... 408

cclogite rocks............................ 602

formation of zeolites..................... 413

glauconite............................... 512

gold in gneiss............................ 640

ktypeite................................. 550

lateritc.................................. 489

mincrvitc............................... 518

Mont Petee........................ 262,266,357

occurrence of lawsonitc.................. 407

phosphates of lime....................... 519

phosphatized andesito................... 517

planch&tc............................... 669

recent cerusite........................... 686

scapolito rocks......................... 401,600

spinel in troctolitc....................... 33S

tridymitc............................... 357

villiaumitc............................. 368

volcanic sublimates.................... 265,266

wollastonito in aplitc.................... 374

See also Michel-L6vy and Lacroix. 

Lacroix, A., and Barct, C., wernerite rock... COO 

Lacroix, A., and de Schultcn, A., Laurium

slag minerals................... 6S6

Lacu Sarat, analysis of water............. 168,171

saline deposits.......................... 228

Laczczynski, , analysis of chromito... 339,703 

Ladd, G. E., clays......................... 503

Ladurcau, A., sulphur in atmosphere........ 46

Lagonitc............'........................ 23S

Lagoiio, A., eutcctics........................ 419

formation 01 leucitc...................... 305

fusibility and solubility distinguished.... 301

glass-base................................ 302

pyrogcnic corundum.................... 334

solubility of minerals in magmas........ 303

Lagoriolitc.................................. 397

Lahontan, Lake........................... 155-158

Laine1 , E. See Muntz and Lainfi.

La Junta artesian well, analysis............. 186

Lake, T., lateritc.......................... 488,483

Lampaditc............-...............'..... 531,668

Lamprophyre............................ 436,437

Lanarluto.................................. 687
804 INDEX.

Page. 

Lane, A. C., criticism of Brun............... 278

cutcctics............................... 296,419

magmatic gases........................ 281, 282

mine waters............................. 635

native copper............................ 661

the ocean................................ 125

volcanism................................ 280

waters of Michigan............. 70,181,207,210

See also Keller and Lane.

Lans, A. C.,and Sharpless, F. F., gruncrite.. 379 

Lang J., bauxite............................ 491

Lang, R.,lublinite.......................... 550

Langbeinite................................. 218

Lansfordite.................................. 561

Lanthanite.................................. 17

Lanthanum................................. 17

Lapis lazuli.................................. 369

Lapparont, A. do, distribution of solfataras.. 207 

Laramie lakes, analyses of water........... 160,171

Laramie River, analyses of water............ 80

Larderellite.................................. 238

Larsen, E. S., perofskito rock................ 345

. priceiteandpandermite................. 243

See also Washington and Larsen; Wright

and Larsen.

Larsen, E. S., and Hicks, W. B. searlesite... 243 

Larsen, E. S., and Hunter, J. F., molilito

rock............................. 396

Larsen, E. S., and Schaller, W. T., cebollite. 396 

Larsen, E. S., and Steiger, G., cancrinite..... 369

Larsen, E. S., and Wherry, E. T., leverrierite. 614 

Lartet.L., on Dead Sea................... 165,559

Lasaulx, A. von, alteration of rutile......... 343

kelyphite................................ 399

sulphur deposits......................... 579

See also Sartorius and Lasaulx. 

Laschenko, P. V., aragonitc................. 550

Lasne, H., phosphorite...................... 526

Laspeyres, H., olivine as a furnace product. 385 

sericito.................................. 596

Lassenose................................. 431,448

Lateral secretion............................. 630

Laterite................................... 488-496

Latite....................................... 446

Latouche, T. H. D., and Christie, W. A. K.,

analysis by...................... 169

Latschinofl, P. See Erofe"ef and Latschinofi. 

Lattermann, G., barytic sinter............. 582,583

Lattimore, S. A., analysis by................ 229

Laubanito................................... 412

Laumontite................................. 412

Launay, L. De, average composition of

igneous rock..................... 27

cited.................................... 208

diamond................................ 320

magmatic waters........................ 638

mean atomic weight of lithosphere....... 27

ore deposits.............................. 629

Laur, F.,bauxite............................ 491

gold and silver in Triassic rooks.......... 646

Laurdalite................................... 441

Laurdalose................................ 437,438

Laurionite................................... CS6

Laurite...................................... 707

Laurvikose.................................. 435

Lautarite.................................... 250

Lavenite.................................... 378

Lawrenceite................................. 138

Lawson, A. C., chert........................ 541

corundum rock.......................... 335

mine water.............................. 635

ore deposition........................... 639

See also Adams and Lawson. 

Lawson, A. C., and Palache, C., chert....... 541

Lawson, R. W., age of earth................. 313

Lawsonite................................. 407,408

Lazurite..................................... 209

Lead, distribution........................... 17

from uranium..........:................ 311

occurrence in a coral..................... 120

ores of................................. 6S3-689

'LeadhiUite.................................. 687

Lebedintzeff, A., water analyses............. 163

Leblanc, F. See Deville and Leblanc. 

Lechartier, G., synthesis of mimetite........ 688

syntheses of olivino...................... 386

synthesis of pyroxene.................... 374

Le Chatelier, H., Algerian alkaline deposits.. 236 

clay substances in marl.................. 557

constitution of clay silicates.............. 488

cristobalite.............................. 355

formation of granite..................... 430

fusion of limestone....................... 555

marl..................................... 557

modifications of quartz.................. 355

thermocouple............................ 285

Le Chatelier, H.,and Wologdine, S.,graphite. 322 

Lechler, M., Bavarian waters.........;...... 101

LecMe, J. S., nickel ores..................... 702

Le Conte, J., Nevada boratcs................ 241

Le Conte, J., and Rising, W. B., mercury

deposits......................... 674

Leddin, . See Blum.

Ledoux, A. R., nickel ores................... 701

Leduc, A., hydrogen in atmosphere.......... 45

Lee, G. W. See Collet and Lee.

Lee, W. T., Cove Creek sulphur........... 194,5SO

Leffman, H., waters of Yellowstono Park.... 190

Lefort, J., analysis by....................... 195

Legendre, R., carbon dioxide in air.......... 47

Leguizamon, M. M., water analysis.......... 161

Lender, J., phosphatic nodules.............. 526

Lehmann, B., sericitic rocks................. 596

Lehmann, T. See Engler and Lehmann. 

Lehrbachite............................... 670,683

Leibius, A., gold............................ 648

Leighton, H. See Ncwland and Leigh ton. 

Leighton, M. 0., analyses of water........... 70

normal and polluted waters.............. 109

Leith, C. K., actinolite-magnetite schist..... 379

glauconite and greenalite.......... 513,576,577

origin of magnetite...................... 341

See also Van Hise and Leith. 

Leith, C. K., and Mead, W. J., iron ores..... 529

metamorphic geology................... 591

Leitmeier, H., calcium carbonate.......... 199,549

nesquehonite......................... 561,570

spring deposits.......................... 199

Lekene...................................... 728

Leman, Lac, analysis of water............... 94
INDEX. 805

Page. 

Lemberg, J., alterations of feldspar........ 303,606

alteration of spodumene and jadeite..... 376

of topaz............................. 405

artificial cancrinite...................... 309

ehlorito pseudomorphs.................. 393,399

composition of socialite................ 369,370

decomposition of rocks................... 482

double decompositions in silicates....... 496

epidotization............................ 601

fusion oflimestone....................... 555

kaliophilite and ncphelite................ 367

Icucite and analcitc...................... 365

predazzito............................... 572

primitive atmosphere.................... 56

reactions with andalusite and kyanite... 406 

withgehlem'te....................... 396

serpentine............................... 605

silication of limestones................... 557

syntheses of zeolites................... 406,413

tests for calcite and dolomite............. 562

Leme'tayer, P., water analysis............... 92

Lemiere, L., formation of coal............... 771

Lemoine, P. See Chautard and Lernoine. 

LcnarciC, J., formation of augite............. 378

formation of magnetite.................. 341

of nephclitc.......................... 368

fusion of mineral mixtures............... 300

re:rystallization of albite................ 361

Lenecek, 0., predazzite...................... 572

Lengenbachite.............................. 684

Lengycl, B. von, analysis of water........... 168

I.enher, V., gold telluride.................... 649

precipitation of gold................... 652,653

solution of gold.......................... 652

See also Hall and Lenher. 

Lenher, V., and Merrill, H.'B., solubility of

silica............................ 476

Lcnicque, H., carbide theory of volcanism... 275 

origin of petroleum...................... 736

primitive atmosphere.................... 57

Lenk, H., augitc-scapolite rock.............. 401

Lcnox, L. R., corals......................... 554

Lenz, O., itabirite........................... 612

Lenz, R.,laterite............................ 489

Leonard, A. G., gas well..................... 737

zinc deposits............................. 682

Leonite...................................... 218

Lcpape, A. See Moureu and Lepape.

Lepidolite...................... 387,388,390,391,692

Lepidomelane............................... 388

Lepidophceite............................... 532

Lepierre, C.,fluorineinspringwaters........ 188

Lepsius, B., composition of dissolved air..... 472

Lcpsius, R., glaucophaneschists............. 594

Lcrmondose..;.............................. 461

Lesley, J. P., grahamite..................... 728

Lesquereux, L., origin of petroleum......... 741

Lester, O. C., radioactivity of water......... 209

Letheby, H., water analyses................. 105

Letts, E. A., and Blake, R. F., carbon dioxide

in air............................ 46,47

Leube, G., dolomite......................... 563

Page. 

Lcucite................................ 268,363-366

melting point.......................... 287,290

Leucite basalt............................... 454

Leucitc rocks.......................... 442,443,454

Leucite syenite.............................. 442

Leucitite.................................... 442

Leucopyrite................................. 694

Leucoxene.................................. 344

Leuk, analysis of water...................... 183

Lcvat, E. D., gold and silver in diabase..... 632

nickel ores............................... 702

phosphate rock.......................... 524

Leverett, F., loess........................... 505

Lev«rrlerite............................... 389,614

Lcvi, M. G., radioactivity of lava............ 309

Levin, M., decay .of uranium.............. 311,313

Levin, M., and Ruer, R., radioactivity.... 308,311

Levings, J. H., gelatinous silica in ore bodies. 352 

Levison, W. G., decomposition of rocks.... 472,475

L6vy. See Michel-LeVy; Fouque1 and MichelLdvy. 

Levy, A., nitrogen compounds in rain....... 52

Levynite.................................... 412

Lewin, L. See Schweinfurth and Lewin.

Lewis, H. C., origin of diamond.............. 320

Lewis, J. V., North Carolina corundum..... - 335

See also Pratt and Lewis. 

Lewisite..................................... 697

Lewy, H., analysis by....................... 194

Lherzolite................................... 459

Libbey, W., volcanic gases.................. 263

Liebenow, C., radioactivity.................. 310

Lieber, 0. M.,itabirite...................... 612

Liebert, H., uranium in coal................. 717

Liebisch, T., silver antimonides............. 654

Liebrich, A., bauxite...................... 491,492

Lienau, H.,bauxite......................... 493

Lignin....................................... 746

Lignite................................ 753-758,763

Lignocellulose............................. 746,758

Lignone..................................... 746

Lillianite.................................... 684

Limburgite, fusibility.......................

Limburgose................................. 454

Limestone......................... 546-557,623-627

average composition..................... 29,32

formation of........................... 127,128

Limnite..................................... 527

Limonite...'............................... 527,574

Linarite..................................... 687

Linck, G., associates of spinel................ 338

oolite.................................. 551,552

origin of clay............................ 487

origin of dolomite........................ 559

orthoclasc in dolomite................... 625

solubility of calcium carbonate.......... 127

troilite.................................. 328

Lincoln, A. T., See Kahlenberg, L.

Lincoln, F. C.,gold.......................... 650

igneous rocks............................ 421

magmatic gases.......................... 284

Lindemann, B., minerals in limestone....... 626

Lindgren, W., analcite in rocks............ 366,444
806 INDEX.

Page. 

Lindgren, W., broohantitc .................. 669

chalcoclte.............................. 661,666

fiuorite in sinter......................... 199

magmatic magnetite..................... 341

magmatic waters as vein fillers........ 203,63S

monazite sand........................... 351

native copper............................ 661

Ojo Caliente............................. 186

ore deposits............................ 629,639

orthoclaso as a ganguo mineral........... 362

pscudomorphous galena................. 684

scricite and calcite....................... 597

sodalitesyenite.................... 366,371,444

stibnite in sinter......................... <£%

tin deposits.............................. 692

tungsten ores............................ 706

Lindgren, W., and Hillebrand, W. F.,

coronaditc....................... 532

Lindgren, W., and Whitehead, W. L., jamcsonite............................ 685

Lingula................................... 521,522

Linnaate.................................... 698

Linosite..................................... 384

Liparitc...................................... 432

Liparose............................... 431,433,468

Lipp, A., analysis by........................ 180

Lisboa, A., monazite sand................... 351

Litchfieldite................................. 441

Litbiophilite................................. 693

Lithium, distribution....................... 17

In sea water............................. 119

Lithospliero, average composition........... 24-35

volume of................................ 22

Little, C!.,leadsclcnidc...................... 683

Little, 0. H. See Cole and Little.

Livcing, G. D., cited......................... 45

Liversidge, A., analyses by................ 181,702

bog iron oro............................. 530

cobalt ores............................. 701,702

coral..................................... 554

distribution of silver..................... 653

gold in recent pyrite..................... 650

in sea water......................... 120

in rock salt........................ 120,646

mercury in sinter........................ 675

precipitation of gold..................... 652

silver in sea water....................... 120

solvents of gold........................ 650,651

Livingstonite.............................. 670,696

Ljubavin, N., cave earth.................... 248

Ljusnan, River, analysis of water............ 103

Lloyd, S. J., radium in sea water............ 121

Lloyd, S. J., and Cunningham, J., radium in

coal............................. 750

Loch Baile a Ghobhainn, analysis of water.. 93 

Locke, J. M., uintaite........................ 728

Lockyer, J. N.,cited........................ 12

Loebisch, W., and SipScz, L., water analysis. 122 

Lollingite.................................. 331,694

Loess...................................... 504-506

Loow, O., analyses by............... 82,154,158,230

Loowe, L., cited, on Stassfurt salts.......... 216

Lowenstein, H., clays....................... 495

Page. 

Loewinson-Lessing, F., average composition

of igneous rocks.................. 25

classification of igneous rocks............ 421

eutoctics............................... 299,419

fractional crystallization................. 305

magnetic differentiation.............. 2D2,302

origin of volcanic gases................... 275

solubility of minerals in magmas......... 303

Loewite... ............................... 218

Logan, W. E., and Hunt, T, S;, phosphatic

shell............................. 521

Lohmann, P., eclogito....................... C02

Loire, River, analysis of water............... 94

Lonar Lake, analysis of water............. 109,172

Long, J. H.,cited........................... 70

Longbanite.................................. 097

Longyoar, R. D. See Roberts and Longycar. 

Lorandite................................... 094

Lord, E. G. E., analysis by......;........... 457

Lord,N. W.,coal........................... 758

Lorcnz, N. von, water analysis.............. 98

Lorenz, R., synthesis of greenockito and

wurtzite.__.................... G76

synthesis of troilite...................... 328

Lorenzen, J., graphite in basalt.............. 323

native iron.............................. 324

Loretz, H., iron ores......................... 577

Losanitscb, S. M., chromiferous clays........ 703

Losscn, C., itabirito.......................... 612

quartzitc................................ 610

Losscn, 1C A., albito alterations............. 597

Losssnite.................................... 6S9

Lossier, L., water analyses................... 94

Lost River, analysis of water................ 86

Lotti, B., copper ores........................ CCS

stibnite and cinnabar.................... 69G

Lotz, H.,cited............................... 478

Louderback, G. D., radioactivity and volcanism.......................... 310

Loughlin,G.F.,clays......................... 503

zinc oros................................. G78

Louisville artesian well, analysis............ 1S2

Lowe River, analysis........................ 87

Lozinski, V. von, chemical denudation...... 147

Lublinite.................................... 550

Luca, S. dc, analysis by..................... 191

Lucas, A., chemistry of tho Nile............. 10-1

natural soda............................. 231

Lucas, R., physical properties of clays....... 497

Ludlamite................................... 516

Ludwig, A., artificial diamond.............. 318

Ludwig, E., analyses by................... 183,186

Ludwig, F.,analyses by........... 103,167,228,229

Ludwig, F. J. H., analyses by._........... 200

Luedecko, 0., water of the Oder............. 102

Luedeking, C., lead chromates............... 688

Luedeking, C., and Wheeler, H. A., barito... 583 

Luncburgite................................. 245

Lujavrose................................... 438

Lukens, H. S., scandium in wolfram......... 19

Lunge, G., cited, on S tassfurt salts......... 216,221

natural soda............................. 234

Lungo, G., and Millberg, C., solubility cf

quartz........................... 353
INDEX. 807

Page.

Lungo, G., and SchmicU, R. E., analysis by.. 183 

Lunn, A. C., Internal temperature of the

earth..........'.................. 285

Lungwitz,E.E.,gold..............:...... 650,652

Lupton,N. T., analysis of water, cited....... 79

Lutecine.................................... 353

Lutecium................................... 17

Luz, A., bauxite............................. 494

Luzi, W., corrosion of diamond.............. 320

formation of graphite.................... 322

Lyell, C., precipitated calcium carbonate.... 547

Lyons, A. B., copper in lava................. 632

soils..................................... 503

M. 

Mabery, C, F., natural gas................. 722,723

petroleum............................. 722,724,

725,726,727,738,739 

Sec also Eobinson, A. E.

Mabery, C. F., and Byerly, J. E., byerlite... 729 

Mabery, C. F., and Hudson, E. J., petroleum..................... 724,725,720

Mabery, C. F., and Palm, 0. H., Ohio petroleum............................ 725

Mabery, C. F., and Quayle, W. 0., petroleum.......................... 724,726

Mabery, C. F., and Smith, A. W., Lima oil.. 720 

Mabery, C. F., and Takano, S., Japanese petroleum......................... 724

MacAlister, D. A. See Hill and MacAlister. 

Macallum, A, B.,cited...................... 125

MacBride, T. H., peat....................... 753

McCalcb, J. F.,cited......................... 222

McCalley, H., bauxite....................... 492

McCtillie, S. W., iron ores.................. '529;578

limestones............................... 556

phosphate rock.......................... 520

waters of Georgia....................... 64,210

McCaughey, W. J., solubility of gold......... 651

McClelland well, analysis.................... 186

McClondon, J. F., carbonates in sea water... 127 

McConuoll, W., gases in coal................. 767

McCourt, W. E., and Parmeleo, C. W., peat. 753 

McCreath, A. S., coal analyses............... 761

McDonnell, C. C., and Smith, C. M., synthesis

of mimetito...................... 688

Mace', , synthesis of anglesite............. 687

Macfarlane, W. See Ebaugh and Macfarlane. 

McGeo, W J, bitumens....................... 743

laterite.................................. 488

loess..................................... 505

Mcllkeney, P. C., solvent of gold............ 651

Mclntosh, D. See Eve, A. S.

Mclvor, R. W. E., guano phosphates........ 516

maldonite............................... 648

McKce, R. H., mass of atmosphere.......... 55

McKcnzie, J. D., blairmorite................ 444

primary analcite......................... 366

Mackie, W., allanito in granite............... 404

analyses of clays....................... 502/503

analyses of sand......................... 499

calcium fluorido as cement............... 537

on age of the earth....................... '147

sandstones............................... 539

Mackintosh, J. B. See Hidden and Mackintosh. 

Mackintoshite............................. 313,720

 ? Page. 

Maclaren, J. N., gold and silver in sinter.... 202,650

hot springs of New Zealand.............. 207

Maclaren, M., laterite........................ 489

Maclaurin, J. S., cited, on New Zealand

spring waters.................. 190,195

mine waters........................:.... 635

McLennan, J. C., and Kennedy, W. T., radioactivity ......................... 311

McNairn, W.H.,apatite.................... 519

Macomb deep well, analysis of water......... 183

Mactcar, J., mercury ores.................... 670

Madupite.,.................................. 442

Madupose................................... 442

Maey, E., silver antimonidc................. 654

Magdeburgose......................... 431,432,433

Magma, temperature of...................... 277

Magmatic assimilation....................... 303

Magmatic differentiation.............. 292,301-307

Magmatic dissociation....................... 297

Magmatic solutions........................ 292-294

Magmatic stoping........................... 304

Magmatic waters............................ 208

Magncnat and Wootcn, analyses by......... 756

Magncsioferrite.............................. 338

Magnesite............................. 411,413,562

Magnesium, distribution..................... 17

Magnetite................. 287,338,340-342,572,573

Magnetite basalt............................. 463

Magnetite spinellito......................... 462

Magnetite syenite............................ 464

Magnochromite.............................. 703

Mahanuddy River........................... 104

Mahler, 0., calcite and dolomite........... 560, 563

Main, River, analysis of water............... 98

Majima, M. See Yamashita and Majima. 

Majorana, Q.,diamond...................... 318

Maldn, C. J. S., analysis of sea water......... 122

Malacca, Straits of........................... 122

Malachite.................................. 669,750

Malaguti, Durocher and Sarseaud, silver in

sea water........................ 120

Malbot, H. and A., phosphorite............. 523

Malcolmson, J. W.' See Kirk and Malcolmson. 

Maldonite................................... 648

Malheur Lake, analysis of water........... 159,172

Malignose................................... 440

Malkomesius, P., and Albert, R., Cassel

brown........................... 757

Malladra, A., water from fumarole........... 279

Mallard, E., cristobalite..................... 352

lead oxychlorides........................ 086

Mallet, F. R., Indian corundum............. 334

laterite.................................. 488

lateritic manganese.................... 532,533

on langbeinite........................... 219

Mallet, J. W., allanite....................... 719

analysis by.............................. 202

gases from meteorites.................... 282

silver in volcanic ash.................. 266,631

Maltha...................................... 729

Manchot, W., ilmenite....................... 344

Mangandolomite............................. 575

Manganese, distribution..................... 18

in sea water............................. 120

ores of......................^.......... 531-534
808 INDEX.

Page. 

Manganese nodules.................... 130-132,531

Manganite..................'................. 531

Manganosite................................. 531

Manitoulin Island, analysis of water from.... 181

Manjak................................ 713,729,730

Manley, J. J. See Gunther, R. T.

Mann, P., alteration of titanite.............. 345

constitution of pyroxenes................ 379

Manouschek, 0. See Donath and Manouschek. 

Manross, N. S., asphalt...................... 729

synthesis of apatite.................:.... 349

of lead ores ........................ 687,688

of scheelite.'......................... 706

Mansfield, G. R., phosphate rock............ 525

Marcano, V. See Muntz, A.

Marcasite.................:.................. 330

Marck, W. von der, analysis of sandstone... 536,537 

Marckwald, W., radioactivity............... 315

uranium ores. .......................... 714

Marcus, E., saltclay.......:................. 217

Marcus,E.,andBiltz,W.,Stassfurt salt clay 217,712

See also Biltz and Marcus. 

Marcusson, J., artificial petroleum........... 734

origin of petroleum...................... 738

optical activity of petroleum............. 743

Mare Morto, analysis of water................ 122

Margarite.................................... 388

Margarodite................................. 387

Margottet, J., reduction of silver sulphide.... 654

synthesis of argentite.................... 655

. See also Hautefeuille and Margottet. 

Marialite.................................. 400,600

Maricose..................................... 459

Marienquelle, analysis of water.............. 180

Marignac, C. de, synthesis of dolomite....... 558

Marigny, F. D., Algerian waters............. 67

synthesis of bornite...................... 664

synthesis of galena....................... 683

Marin, A. See Rubio and Marin. 

Marl................................... 513,548,549

Marmora, Sea of, analysis of water........... 122

Marsden, R. S., artificial diamond........... 318

formation of crystalline silica............ 353

Marsh gas......................... 735,737,738,766

Marshite..................................... 668

Marsilly, , analysis of peat............... 751

Martens, P., Chilean thermal waters......... 247

Martin, K., phosphate rock.................. 517

Martin, W. J., platinum ores................ 707

Martinite................................... 517

Masing, E., synthesis of anglesite............ 687

Mason, W. P., analysis by.................. 186

Massicot.................................... 685

Massol, G., helium in spring water..:........ 176

Matthews, E. B., classification of rocks...... 429

Matildite.................................. 658,659

Matlockite.................................. 686

Matson, G. C., phosphorite.................. 524

Matteucci, R. V., volcanic ammonium chloride............................. 267

Matthews, W. D., phosphatic nodules....... 521

Maucherite.................................. 698

Maumee River, analysis of water............ 70

Maurnene', E., manganese in sea weeds....-.- 120

Mauritz, B., synthetic wollastonite.......... 373

Mauzeliitc-.................................. 697

Mawson, D.jCarnotite..:...-.............'... 717

Mawson, D., and Cooke, W. T., phosphates

from guano...................... 518

Mawson, D., and Laby, T. H., radioactivity

of minerals...................... 309

Maxwell, W., Hawaiian lavas and soils. 488,489,494 

Maycncon, , artificial galena............. 683

sulphides formed in burning coal mine... 695 

Mayr, F. See Simmersbach and Mayr. 

Mayrhofer, J.,cited.......................... 101

Mead, W. J., average composition of igneous

rocks............................ 25

bauxite................................. 493

relative proportions of sedimentary rocks. 30,33 

See also Smith and Mead.

Meadows, T\ C., and Brown, L., phosphorite. 523 

Mecca, holy well at, analysis of water........ 192

Mediterranean Sea, analysis of water...... 122,214

Medve Lake................................. 168

Mehu, M. C., synthesis of cinnabar.......... 671

Meigen, W., caleite and aragonite...... 549,550,551

calcium carbonate as precipitant of metals.............................. 645

dolomite................................ 559

latcrite.................................. 489

Meionite.............................. 399,600,604

Melanite...'................................. 397

Mclanochroite............................... 687

MelanoteMte................................ 689

Melcher, A. G., silver halides................ 600

Meldrum, R., solubility of copper........... 661

Melilite............................... 394,396,604

Mellite...................................... 749

Mellor, J. W., clay silicates................ 488,614

Melnikovite................................. 330

Melonite.................................... 698

Melvill, E. H. V., diamonds................. 321

Melville, W. H., analyses by............. 158,182,

192,326,444,539,544,595,609,613,674,696 

glaucophane rock........................ 594

joscphinite.............................. 326

Menaccanite................................. 343

Menaul, P. L. See Clark and Menaul. 

Mendelecf, D., origin of petroleum........... 735

periodic classification.................... 38

Mendipite...................................' 686

Meneghinite................................. 684

Mennell, F. P., average composition of igneous rock......................... 27

laterite.................................. 489

Mcrawoc River, analysis of water............ 104

Mercury, distribution....................... 18

ores of................................. 670-675

Mcrensky, H.,diamonds.................... 321

Merian, A., constitution of pyroxenes........ 379

Merivale, W., manjak....................... 729

Merrill, F. J. H., gypsum................... 578

Merrill, G. P., analyses by................. 482,483

asbestos................................. 379

cave gypsum............................ 224

disintegration of rocks. 476,477,479,482,483,484 

gold in granite........................ 328,646

meteorites............................. 41,7C7

onyx marble............................ 547

serpentine........................... 605,606
INDEX. 809

rage.

Merrill, H. B. See Merrill and Lcnher. 

Morrill, J. A., flint........................... 541

Mcrrimac River, analysis of water........... 72

Merwin, II. E. See wlcr Fcrguson, Hillcbrand, Johnston, Posnjak, Rankin, Zics.

Merz, A. R., and Gardner, R. F., analyses by. 227 

Merzi, C., water analysis..................... 98

Mesitite................................... 414,573

Mcsolitc..................................... 412

Me'tabrushite................................ 517

Metachlorito................................. 392

Mctacinnabarite........................... 670,674

Mctahowcttitc............................... 717

Metallic ores............................... 629-720

Mctam orphic rocks.................'....... 586-628

Mctastibnite .......................'....... 695,696

Meteorites, average composition............. 40,41

diamonds in............................. 319

gases from............................. 269,282

hydrocarbons in......................... 736

Metzger, C., water analysis.................. 101

Meunier, S., analysis by..................... 181

bauxite................................. 491

carbon in meteorite.......'.............. 736

composition of fossil plants.............. 759

origin of petroleum...................... 735

of platinum......................... 710

planetary atmospheres.................. 56

synthesis ofanorthite................... 360

synthesis of brochantite................. 669

. ofchromite........................ 339,704

of cnstatitc.......................... 372

ofleucite............................ 304

of nephelite......................... 368

of olivino............................ 386

of phoonicochroite................... 688

of spinel............................. 338

of tridymite......................... 354

t i n in sinter........................... 201,691

troilite.................................. 328

volcanic explosions...................... 291

See also Daubre'o and Mounier. 

Meuscjlivcr, analysis of water............... 94

Mexico, Gulf of.............................. 122

Meyer, E. von, gases in coal................. 767

Mcycr, J., gases in coal...................... 768

Meyer, 0. calcite and dolomite.............. 562

Moyerhoffcr, W., phase rule................. 298

See also Van't Hofl and Meyerhoffer. 

Miami River, analysis of water.............. 79

Miargyrito................................ 658,659

Miaskose.................................. 438,444

Micas...................................... 387-392

Mica schist................................. 617-620

Michael, P., saussuritegabbro................ 598

Michcl, L., bismuth in molybdenite......... 705

synthesis of azurite....................... 669

of lead ores......................... 685,688

of melonite-.......................... 398

of minium and plattnerite........... 685

of powellite.......................... 705

of rutile.............................. 347

of titanite-..... ? ..................... 345

of tungsten minerals................. 706

Page.

Michcl-L6vy, A., magmatic differentiation... 304 

minerals in sand......................... 498

primary cpidote.......................... 403

quantitativeclassification................ " 429

scapol i te gabbro.......................... 599

Michcl-L6vy, A., and Lacroix, A., envelopment of allanite.................. 404

Michel-Lgvy, A., and Municr-Chalmas, E.,

chalcedony....................... 352

Michigan, Lake, analysis of water............ 70

Microcline................................... 359

Micrometric analysis of rocks................ 470

Micro-organisms in coal formation........... 771

Micropegmatite, as an cutectic............... 296

Microsommite.............................. 268,369

Middlemiss, C. S., Indian corundum......... 334

Miersi tc...................................... 660

Mikhailovsky, G. P., origin of naphtha'...... 743

Miklucho-Maclay, M. von, occurrence of

cassiterite........................ 348

Milch, L., glaucophanerocks...;.............. 594

quantitative classification. ................ 429

Milford,L.R., cited......................... 182

Millar, C. C. H., phosphates............:..... 523

MiUberg, C. See Lunge and Millbcrg.

Mil,le Lacs Lake, analysis of water........... 77

Miller, A. M., phosphatic fossils.-............ 521

Miller, B. L., graphite....................... 323

See also Singewald and Miller. 

Miller, N. H. J., composition of rain water. 46,52,53 

Miller, W. G., cobalt ores.................... 700

corundum anorthosite................... 334

iron ores................................. 529

1 imestone................................ 556'

magmatic assimilation................... 304

nickel in magnetite...................... 340

Miller, W. J., metamorphism................ 591

Milleritc.........'................. I.... 698,699,750

Mills, J. E., geological work of ants.......... 4SO

Milosin...................................... 703

Mimeti te.................................... 688

Minasragritc................................. 714

Minervite.................................. 518,519

Mincttc.................................... 436,437

Minette (iron ore)............................ '577

Mine waters................................ 635-637

Mineral waters, classification....... 170-173,176-177

Mingaye, J. C. H,, analysis by............. 188,518

cave phosphates......................... 518

mine water.............................. 634

platinum.......................... 707,710,711

vanadium in clay........................ 712

Minium...................................... ,6S5

Minnesota River, analysis of water........... 77

Minnetonka, Lake, analysis of water......... 77

Minor, J. C. See Penfield and Minor. 

Minssen, H., and Tackc, B., solubility of

calcium phosphate............... 515

Mirabilite.......................... 168,228,242,250

Miser, H. D., Arkansas diamonds............. 321

Mispickel..................................... 694

Missouri River, analyses of water.............. 80

Missourite................................... 442
810 INDEX.

Page. 

Mississippi Eiver, analyses of water.......... 76

chlorine in............................... 108

sedimentation in......................... 501

silt....................................... 501

Mittagong chalybeate spring, analysis........ 188

Mitchell, , water analysis cited........... 165

Mitchellite................................... 703

Mixite....................................... 668

Mizzoniic.................................... 400

Moricke, W., gold in pitchstonc............ 328,646

Mofettes..................................... 257

Mohawkite................................... 663

Mohawk River, organic matter in............ 106

Mohr,E.C. J.,laterite....................... 489

rivers of Java............................ 104

Moissan, H., analyses of volcanic gases..... 262,263

carborundum in meteorite ................ 322

graphite in native iron................... 323

meltingpoint of corundum............... 332

metallic carbides....................... 275,731

on diamond............................ 318,319

origin of petroleum....................... 731

origin of volcanic activity.............. 275,281

volatility of metallic oxides.............. 267

Sec also Becqucrel and Moissan. 

Moitessier, A., artificial dolomite............. 559

Moldau River, analysis of water.............. 99

Moldenhauer, F., analysis by................ 97

the Dead Sea............................ 165

Molengraaf, G. A. F., cordicrite vitrophyritc- 401 

Molcngraaf, P. F., cassiterite................. 694

Mollusks............................... 565,633,739

Molybdenite................................. 330

Molybdenum, distribution................... 18

in mine water............................ 635

ores of.................................. 704-707

Molybdic ocher.............................. 704

Molybdophyllite............................. 689

Molybdosodalite............................. 369

Monazite............................... 350,351,719

M onchiquite................................. 444

Monchiquose................................ 444

Monckton, G. F., mercury deposits.......... 674

Monetite..................................... 517

Monke, H., and Beyschlag, F., origin of

petroleum........................ 738

Monmouthite................................ 441

Mono Lake, analysis of water.............. 158,173

Monongahela Kiver, analysis of water........ 79

Montcsano Springs, analysis.................. 179

Monticellite................................ 385,387

Montmorillonite........................ 412,495,614

Montroyditc................................. 670

Monzonite................................. 446,447

Monzonose............................. 435,446,451

Moore, C. C., barytic sandstones............. 537

sandstones............................... 539

Moore, E. J., bog iron ore.................... 528

Moore, E. S., siliceous oolites................ 542

Moore, G. E., analysis by.................... 192

Moore, N. P. See Young and Moore 

Moore, R. B., and Kithil, K. L., uraniumvanadium ores.................... 716

Moosehead Lake, analysis of water........... 72

Morawsky, T. See SeMnnercr and Morawsky. 

Mordenite................................... 412

Moreing, C. A., manganese ores.............. 533

Page. 

Morenosite.................................. 701

Morcy, G. W., and Niggli, P., hydrothermal

syntheses........................ 589

Morley, E. W., variations in atmospheric

oxygen.......................... 43,44

Morlot, A. von, sand calcites ................ 535

synthesis of dolomite ......±............. 558

Morozewicz, J., alteration of diorite.......... 483

analysis by.............................. 462

artificial feldspars...................I.... 360

composition of nephelito................. ^67

formation of acmite...................... 376

of augite............................. 378

of corundum....................... 332-334

of enstatite.......................... 373

of hematite........... ; .............. 342

ofiolitp............................ 334,401

of magnetite......................... 340

of mclilite........................... 395

of mica.............................. 390

of nephelite.......................... 368

of pyroxene.......................... 374

of quartz and tridymite.............. 356

ofsillimanite...................... 333,408

of spinel............................. 333

lagoriolite............................... 397

gravitative adjustment in magmas....... 306

syntheses of noselite, haiiynite, and sodalite............................ 370,371

of pyroxenes....................... 373,374

solubility of alumina in magmas......... 299

Morrey, C. B., origin of petroleum........0.. 743

Morris, H. H., precipitation of gold.......... 652

Morse, H. W., gases in fluorite............... 331

Morton, E. H. See Thorpe, T. E.

Moses, A. J., mercury minerals.............. 671

Moses, 0. A., phosphate rock................ 523

Moses Lake, analysis of water.............. 160,172

Mosesite................................... 670,671

Moss, E. L.,ou Arctic air.................... 47

Mottramite.................................. 713

Moulton, F. R., internal temperature of the

earth............................ 285

Mourolo, J. R.,mineral syntheses...... 338,350,689

Moureu, C., and Biquard, R., argon and

helium in waters................ 176

radioactivity of waters................... 176

Moureu, C., and Lepape, A., helium in spring

waters........................... 312

Mourlot, A., vanadium in coal............... 713

Mrazec, L.,petroleum....................... 739

Mrazec, L., and Teisseyre, W., Roumanian

salts............................. 223

salt lakes of Roumania.................. 168

Mrha, J.,kelyphite.......................... 399

Muchin, J., von, analyses by................ 70S

Muck, F., constitution of coal................ 772

Muck, J., ozokerite.......................... 728

Muds,oceanic............................. 508,509

Mugge, 0.,calciteandaragonite............. 549

fluorite as cement....................... 537

forms of silica............................ 355

lublinite................................. 550

occurrence of pcrofskite.................. 345

scapolito amphibolite.................... 600

. transition of quartz...................... 355

Miilhauser, 0., artificial graphite........... 322
INDEX. 811

Page. 

Muller, E., water analysis................... 101

Miillcr, H., mine water...................... 636

Muller, R., solubility of minerals.. 350,473,474,515 

Miillcr, W., artificial magnetite.............. 340

Muller, W. J. Sec Konigsberger and Muller. 

Muller, W. T., and Konigsberger, J., hydrothermal syntheses............... 589

Muellerite................................... 516

Minister, C. A., gold in sea water............ 120

Minister, H.j bauxite.-...................... 491

Mumford, E. M., iron bacteria............... 523

Munroe, C. E., artificial hematite............ 342

Muntz, A., atmospheric transport of salt..... 54

bacterial decomposition of rocks......... 480

bromine in Chilean niter................. 250

nitrates in the Nile...................... 104

origin of nitrates......................... 252

Muntz, A., and Aubin, E., oxygen of the

atmosphere...................... 43

Muntz, A., and Laine", E., nitrates in the

atmosphere...................... 52

Muntz, A., and Marcano, V., black waters of

South America.................. 90

cave nitrates............................. 248

nitric acid in rainfall..................... 52

Murdoch, J. See Graton and Murdoch. 

Murdoch, J. A. W.,atacamite............... 668

Murgoci, G. M., amphiboles................. 382

glaucophane schists...................... 594

riobockito rocks.......................... 384

Murray, Sir J., chemical reactions on ocean

floor............................. 130

oceanic carbonic acid.................... 142

origin of manganese nodules............. 131

saline matter in rivers................... Ill

total annual rainfall and run-off......... 59

volume of the ocean..................... 22

Murray, J., and Irvine, R., ammonia in sea

water............................ 119

calcium carbonate in sea water........ 127,128

discharge of rivers.......................59,125

formation of siliceous ooze............... 511

maintenance of marine life............... 145

manganese nodules...................... 131

ro-solution of coral rock.................. 126

secretion of lime salts by marine animals 126 

sediment in sea water.................. 501,503

silica in sea water........................ 119

Murray, J., and Renard, A. F., deep-sea deposits...................... 128-130,512

giauconite............................. 133,512

oceanic sediments................. 128,129,130

phosphatic nodules.................... 132,521

solubility of silica........................ 128

Murray, R.M., the Dead Sea................ 165

Muscovite................................. 387-392

Muskingum River, analysis of water......... 79

Muthmannite............................... 649

N.

Naab River, analysis of water............... 101

Nacken, R., synthesis of apatite............. 350

Nadorite.................................... 689

Nagyagitc................................... 683

Nahe, River, analysis of water .............. 98

Nahnscn, M., dolomite...................... 570

Nantior, A., phosphorite..................... 426

Nantokite................................... 668.

Napalitc................................... 674,727

Naphthcncs................................. 724

Naphthalene................................ 725

Naschold, W. See Haeussermann and

Naschold. 

Nasini, R., origin of boric acid............... 240

See also Pcrrone and Nasini. 

Nasini, R., and Andcrlini, F., analysis by... 180 

Nasini, R., Anderlini, F., and Salvador!, R.,

fuinarolo gases............. 176,240,250

Nasini, R., and Levi, M. G., radioactivity of

lava............................. 309

Nasiui, R., Levi, M. G., and Agcno, F., water

analysis......................... 184

Nason, F. L., Franklin zinc ores............. 682.

iron ores................................. 572

scapolite rocks........................... 600

Nasonitc.................................... 6S9

Nastukoff, A., cellulose...................... 740

Natrolite................................;... 412

Natron............................ 160,233,237,248

Natron Lake, analysis of water............ 169,172

Natterer, K., ammonia in sea water......... 119

analysis of water....................... 122,166

carbonates in sea water.................. 142

diffusion of salts......................... 170

marine muds............................ 510

potash in marine sediments.......'....... 137

Natural gas. ................................ 721-723

Naumannite............................... 657,CS3

Navarro, F., native iron..................... 324

Ncagh, Lough, analysis of water............. 93

Neal, R. O., oil-field waters ................. 727

Nebular hypothesis........................ 137,138

Negro, Rio, analysis of water................ 92

Nelson, J. L.,analysis by.................... 380

Nelson River, analysis of water.............. 88

Nelsonite.................................... 463

Nelsonosc................................... 403

Nendtwich, , analysis by................ 754

Nenticn, .antimony ores................ 690

Neodymium................................. 18

Neon....................................... 18,42

Neosho River, analysis of water............. 82

Neoyttcrbium............................... IS

Nephclitc.............................. 287,366-369

Nephclito basalt............................. 454

Ncphclite rocks........................ 438-441,454

Nephclito syenite............................ 440

Nephrite.................................... 379

Ncpouitc.................................... 702

Ncsquchonitc............................. 561,570

Ncsslcr. See Pcterscn and Ncsslcr.

Neubcrg, C., origin of petroleum............. 738

Neumann, P., diamonds in iron............. 318

Ncusc River, analysis of water............... 73

Nevadite.................................... 432

Ncvius, J. N., tin deposits................... 692

Nevyanskitc................................. 707

Newberry, J. S., bog iron ore................ 528

canncl coal.............................. 760

origin of petroleum.................... 741,742

ozokerite............'.................... 728

Ncwbcry, J. C., gold in iron ore.............. 650

Newbcryite............................:.... 517

Newlaud, D. H.,iron ores................... 464
812 INDEX.

Newlaud, D. H.,and Leighton, H., gypsum.. 220 

Newsom, J. F. See Branucr and Ncwsom. 

Newton, E., iron ores........................ 527

Newton, W., origin of nitrates............... 252

Newtonite................................. 412,614

New Zealand geysers, analyses of waters.... 190

sinter from............................ 195,202

Niccolite....-............................... 698

Nicliols, H. W., cave nitrates................ 248

Corals and crinoids..................... 554,564

sand baritcs............................. 536

Nieholson, E., analysis of water............. 104

Nickel, distribution......................... 18

in ashes of sea weed...'.................. 120

'ores of................................. 698-702

Nickel-iron, native.......................... 326

Nicolardot, P., hydroxides of iron........... 529

Nicdcrstadt, K., Mcigen 's reaction.......... 550

Niggli, P., gas mineralizers.............'..... 284

hydrothermal syntheses...:.............. 589

metamorphic rock series................. 591

See also Johnston arid Niggli; Morcy and

Niggli; Schlaeppfer and Niggli, 

Nile River, analysis of mud................. 500

analyses of water................ J....... 105

'sedimentation in........................ 501

Niobium. See Columbium.

Nishihara, G. S.-, secondary enrichment..... 668

N iton..;...;.:..'..;.........'................ is

Nitrate deposits...'..'.'..................... 248-253

Nitric acid in rainfall........................ 51,52

Nitrogen, distribution....................... 18,34

in sea water............................. 119

proportions in the atmosphere........... 42,45

volcanic................................. 266

Nitrogen bases in petroleum............... 726,739

Nitroglauberite............................ 249,250

Nitze, H. B.C., iron ores.................... 578

monazite.............................. 351,719

Nivcnitc.............................. 313,715,720

Nivoit, E., phosphate rock.................. 515

Noccrite..................................... 265

Nocggerath, J. J., pyromorphite in slag...... 688

Noellner, C., origin of nitrates............... 251

Noclting, J., zinc blende..................... 675

Noir, Lac.................................... 95

Noll, J.C., cited............................. 98

Nontronite.................................. 486

Nordcnskiold, A. E., carbon in meteorite... 736 

native iron in Greenland................ 324

uranium in coal......................... 717

Nordcnskioldinc...............:........... 690,692

Nordmarkite................................ 434

Nordmarkose.............................. 434,440

Norite....................................... 457

North Platte River, analysis of water....... 80

Northupite.................................. 242

Norton, J. H., cited......................... 81

Norzi, G. See Porlezza and Norzi.

Nosean. SeeNoselite.

Nosean sanidinite............................ 443

Nosclito................................... 369,371

Notestein, F. B., uranium and vanadium

ores.............................. 717

Noumeite.................................... 702

Novaculite. ...jO.......................... 540,543

Page.

Noyes, W. A., analyses by.. 70,77,88,185,482,549 

Nutter; E. H., and Barber, W. B., glaucophano rocks..................... 594

Nutting, P. G., uranium and solar spectrum. 312 

Nyholm, E. T. See Ramsay and Nyholm.

0. 

Oak Orchard acid spring, analysis........... K3

Obcrfcll, G. G. See Burrell and Obcrfcll. 

Obalski, J., uranium in pegmatite........... 717

Obsidian.................................... 431

Occlusion of gases in rocks................. 2CS-2SO

Ocean, age of.............................. 146-151

composition of.................. 23,121-120,170

elements in............................ 118-121

gases in................................ 139-5.44

influence of living organisms on.......... 145

the primeval........................... 137-139

volume of................................ 22

Ocean water, carbonates in................ 126-129

changes in composition duo to freezing... 124 

concentration of....................... 121-124

density and salinity of................. 121-120

Oceanic salts, composition of............... 121-120

volume of................................ 23

Oceanic sediments................. 129-136,507-515

Ochers as spring deposits.................. 199,200

Ochrolite.................................... GS9

Ochscnius, C., average composition of igneous

rock............................. 27

cited, on Stassfurt salts................ 215,210

on Great Salt Lake...................... 153

origin of alkaline carbonates............. 236

. of borates............................ 247

of petroleum....................... 739,740

of salt beds.......................... 215

saltpeter deposits.................. 248,249,252

Ocmulgee River, analysis of water........... 74

Oconee River, analysis of water.............. 74

Octahedrite................................ 346,347

Oddn, S., organic matter of soils............. 106

Oder, River, analysis of water............... 102

Oebbeke, K., glaucophane rocks........... 384,594

Oehmichen, H., chalcanthite................ 669

Ogden River, analyses of water.............. 154

Oil shale..................................... 749

Oinouye, G., deposition of sulphur.......... 264

O.jo Caliente, analysis of water............. 186,187

Okcchobee, Lake, analysis of water.......... 74

Okenite..................................... 412

Oklahoma river waters....................... si

Oldham.R. D.,lateritc...................... 488

Old Wives Lake, analysis of water......... 160,171

Olefines............................... 724,730,731

Olctte Springs, analysis...................... 190

Oligoclase................................. 287,359

Olivenite.................................... 668

1'Olivier, V., Chilean nitrates................ 249

Olivine.................................287,384-387

Om, River, analysis of water................ 103

Omak Lake, analysis of water............. 160,173

Omeose...................................... 433

Omphacite.................................. C02

Onega, Lake, analysis of water............... 103

Onofrite..................................... 670

Onyx marble................................ 547

Oolite, calcareous ......................... 155,551
INDEX. 813

Oolite, siliceous............................ 542, £43

Oolitic sand............................... 548,550

Oostananla River, analysis of water.......... 74,75

Opal.................................. 201,352-358

Ophicalcitc.................................. COG

Ophiolite.................................... COO

Orcldfiez, E., petroleum....................... 735

Organic matter in rock decomposition. 105-107,205 

Organic matter in waters................... 100

Orpiment.................................... 095

Orthite...................................... 402

Orthoclase............................. 287,358-303

Orthogneiss.................................. C21

Ortlieb, J., ciplyte........................... 520

Orton, E., dissemination of petroleum....... 744

origin of petroleum...................... v 738

spore cases in coal....................... 771

Osage River, analysis of water............... 82

Osann, A., classification of igneous rocks..... 421

holmquistite............................. 383

rock diagrams........................... 470

Osmium................................... 18,328,707

Osteolite..................................... 510

Oswegatchie River, analysis of water........ 70

Otavite... ................................... C75

Ottawa River, analysis of water............. 70

Otten, F. K., river waters................... 103

Ottrclitc........................... 388,391,015,010

Ottrelite schist............................ 010,017

Cutwater, R., analysis of water.............. 73

0 vcnstone.................................... C09

Ovitz, F. K. Sec Porter and Ovitz.

Owens Lake, analysis of water............. 158,173

soda from.............................. 233-235

Owens River, analysis of water.............. 158

0wyhee River, analysis of water../.......... 85

Oxygen, concentrated by solution........... 51

distribution.............................. 18

proportions in the atmosphere........... 42-44

solubility in salt water................... 51

Or.okcritc.............................. 727,72S,742

Ozone in atmosphere........................ 44

P. 

Pack, J. W., gold in sea water............... 121

Packard, R. L., analysis by................. 4S2

Pagenstecher. J. S. F., water analyses....... 97

Pahua Spring, analysis...............'....... 179

Pnigc, 3., and Stciger, G., serialization...... 597

Paigcito................................... 090,093

Palache, C., crossite......................... 383

See also Jaggar and Palache; Lawson and 

Pabche; Ransome and Palache. 

Polio Lake, analysis of water.............. 108-172

Palladium.............................. 18,707,711

Palladium gold........................ 048,707,710

Palm, 0. H. See Jfabcry and Palm.

Palmer, A. W., chlorine in river waters...... 108

Palmer, C., alkali determinations............ 09

analyses by............................ 70,

72,73,74,75.70,77,79,80,82,83,179 

composition of crinoids.................. 5(51

diatoms in peat.......................... 206

interpretation of water analyses......... 64

sulphides of nickel...................... COS

Page. 

Palmer, C., and Bastin, E. S., precipitation

of silver and gold by ores..... 05:,056 

Palmer, L. A., niagnesite.................. 573

platinum in sulphide ores................ 711

Palmerite ................................... 513

Palmieritc................................ 200, GS7

Pamfil,G. P., gases in ro3ks................. 270

Pancbianco, G., Meigen's reaction........... 5£0

Pandermite................................. "43

Pantanelli, D., origin of petroleum.......... 739

Papagayos, Rio del os, analysis of water..... 92

Papavasiliu, S. A.,, emery................... 335

Papcrcoal.................................. 750

Pappe, A., and Richmond, H. D., salf-. 225

water- analysis.......................... 1CD

Paraflin series......................... 721-723,731

Paragonitc................................ 337,618

Paragnciss.................................. 621

Paralaurionitc............................... CSO

Paramo do Rui:;, hot spring, analysis........ 194

Parana, River, analysis of water............. C2

Pardee, J. T., phosphate rock............... 525

Pargasitc........... -a ....................... 380

Parinacochas, Lake, analysis of water..... 161,171

Park, J., mercury ores....................... 675

Parker, E. G., absorption by soils........... 496

Parker, H. N., and Bailey, E. H. S., waters

of Kansas....................... 03

Parmelee,C.W. Sec McCourtand Parmelcc. 

Parmentier, F., alumina in mineral waters.. 431

synthesis of quartz and tridymite....... 354

Parr, S. W., classification of coals............ 764

Parry, J., gases in iron...................... 282

Parsons, A. L., gypsum..................... 226

molybdenite............................ 705

peat...... 1.............................. 753

Parsons, C. A., artificial diamonds........... 319

Paschcn, F., heat of radium................. 307

Pascoite..................................... 714

Passargc, S., laterite......................... 4S8

Pateraitc.................................... 704

Patronite............................... '..... 713

Patten, H. E., and Waggaman, W. H., absorption in soils................. 490

Patton,H. B., formation of tourmaline...... 409

Paycn, A., Tuscan fumaroles-............... 240

Pearce, R., solvent of gold................... 651

uraninitc................................ 714

Pcarccitc.................................... 658

Pearl River, analysis of water............... 74,75

Peat- -................................ 750-753,763

cupriferous.............................. 662

diatoms in.............................. 206

Pechcr, F., cited............................ 101

Peck, E. L., composition of rain and snow.. 53 

Peckham, S. F.,albcrtitc.. ................. 7:8

origin of petroleum...................... 741

petroleum............................... 726

Peckbam, S. F. and H. E., sulphur in petroleum ............................ 726

Pecos River, analysis of water............... 83

Pectolite.................................. 374,412

Pcedce River, analysis of water............. 74

Peganite......'.............................. 516
814 INDEX.

Page. 

Pegmatite................................... 297

Peile, W., bauxite........................... 492

Peipus, Lake, analysis of water.............. 103

Pckatjangan, River, analysis of water....... 10-1

Pelabon, G., jamesonite and zinkenite....... 685

Pelican Lake, analysis of water............ 160,173

Pelikan, A., analcite phonolite.............. 366

Pellini, G., and Quercigh, E., tcllurides of

gold............................. 649

tellurides of silver....................... 658

Pemberton, H., and Tucker, G. P., water

analyses......................... 160

Pencatite.................................... 572

Penfleld, S. L., analyses by................. 719

caesium beryl............................ 410

sulphohalite............................. 242

See also Dana and Penfield; Genth and 

Penfleld; Iddings and Penfield; 

Wells and Penfleld.

Penfleld, S. L., and Foote, H. W., composition of tourmaline............... 409

magnesia in ilmenite.................... 344

Penfleld, S. L., and Forbes, E. H., fayalite

in granite....................... 386

Penfield, S. L., and Ford, W. E., sand calcite 535 

Penfleld, S. L., and Jamieson, G. S., tychite. 242 

Penneld,. S. L., and Minor, J. C., formula of

topaz............................ 404

Penfleld, r3. L., and Pratt, J. H., formula of

staurolite........................ 407

Penfleld, S. L., and Sperry, F. L., chlorite

pseudomorphs.................. 399

Penfleld, S. L., and Stanley,-F. C., composition of hornblende......... 380,382,383

Penfieldite.................................. 686

Pcnhale, M., chromite deposits.............. 704

Pcnninite................................... 392

Penrose, R. A. F., alterations of ore deposits. 642 

causes of ore shoots...................... 642

Chilean nitrates....................... 250,253

iron ore from glauconito........... 528,529,576

manganese ores.......................... 533

phosphate rock.................... 515,523,526

tin deposits............................. 692

Pcntathionatcs............................ 195,266

Pcntlandite................................. 698

Perchlorates in Chilean niter................ 250

Percy, J., coal analysis...................... 761

copper in peat........................... 662

Percylite.................................... 686

Pcriclase.................................... 572

Peridot..................................... 385

Pcridotite............................. 320,460,461

Periodic classification of the elements........ 36-40

Pcrofskite................................... 344

Pcrofskite-apatite-magnetite................. 463

Pcrrey, A. See Hautcfeuille and Perrey. 

Pcrronc, E., origin of borates................ 240

Pcrrot, F. L. See Jaquerod and Perrot. 

Peter, R., matter extracted from soil by

plants............:.............. 479

cited.................................... 179

Petcrmann, A., and Graftiau, J.,cited....... 47,52

Petorsen, T., bauxite....................... 491

nickelin magnetite..................... 340

Peterscn and Nessler, analyses of peat...... 751

Page. 

Petersen and Schodler, analysis of wood..... 747

FotersEon, W., analysis by........... 1....... 402

Petrasch, K., fusion of mineral mixtures.... 300

Petrenko, G. I., silver antirnouide.......... 654

Petroleum................................. 721-745

Petterson, A., heat of radium................ 307

Petterssbn, O., brine from melting ice....... 12-1

Pettersson, O., and Sonden, K., on air from

sea water....................... 51-140

Petzite...................................... 619

Pfaff, F. W., dolomitization................. 561

Pfeifler, E., cited on Stassfurt salts........ 216,217

Pfordten, 0. von der. See Konig, T.

Phacelite.................................... 367

Phalen, W. C., celestite...................... 581

unakite.................................. 601

Pharmacolite................................ 697

Pharmacosiderite............................ 697

Phenol, in petroleum........................ 726

Philip, R. S. See Gibb and Philip. 

Philippi, E., carbon dioxide and climate... -. 50 

dolomite................................. 561

Phillips, A. H., heavy metals in marine organisms ......................... 633

Phillips, F. C., formation of marsh gas........ 738

natural gas.............................. 723

petroleum in fossils...................... 740

Phillips, J. A., action of sea water on rocks .. 570 

desert sand............................ 498.4G9

gold on cinnabar......................... 650

mercury deposits........................ 674

mine waters............................. 635

sandstone............................... 539

Phillips, W. B., iron ores..................:. 578

petroleum.......... 1.................... 725

phosphorite............................. 523

Terlingua mines......................... 671

Phillips, W. B., and Hancock, D., bauxite.. 492 

Phillipsite................................... 412

Phipson, T. L., primitive atmosphere....... 56

Phlegrose................................... 434

Phlogopite................................ 388-382

Phcenicochroite............................. 687

Phonolite.................................... 438

Phosgenite................................ 684,686

Phosphate rock............................ 515-526

Phosphatic nodules.................... 132,133,521

Phosphorite............................... 519-526

Phosphorus, distribution.................... 18

in sea water............................. 119

Phosphosiderite............................. 516

Phyllite........................... 011,614,617,618

Phy tostearin................................ 743

Pichard, P., solubility of minerals........... 473

Pickeringite................................. 244

Picotite.....-..-............................ 338

Picrite..................................... 458,459

Picromerite.................................. 218

Pictet, A., and Ramseyer, L., experiments

on coal.......................... 773

Pictet, A., Ramseyer, L., and Kaiser, 0.,

hydrocarbons in coal............. 773

Piedmontite............................... 402,403

Pierre, I., salts in rainfall.................... 53,54

Pigeon River, analysis of water............. 70

Pilotti, C., phosphates....................... 523
INDEX. 815

Page. 

Pimelite..................................... 702

Pinitc........................--------- 390,401,402

Pinnoite................................... 220,245

Pinnow, J. See Will and Pinnow.

Pintadoite................................... 717

Piolti, G-., precipitation of zinc by calcite.... 680

synthesis of anglesito.................... 6S6

PirovaroG, J., chlorine in rain............... 53

Pirsson, L. V., cassiterite in hematite........ 691

crystallization of magmas................ 305

primary analcite...................... 366,444

See also Weed and Pirsson. 

Pirssonite................................... 242

Pisani, F., analysis of spinel.-......---.-- - 338

See also Saernann and Pisani. 

Pisolite...................................... 550

Pissis, A., nitrates........................... 249

Pistomesite.................................. 573

Pitchblende............................... 309,714

Pitch coal............................. 727,728,754

Piutti, A., helium in minerals............... 312

Plagionite................................... 684

Planchelte................................... C70

Planetesimal hypothesis.................... 58,138

Plata, River, analysis of water............... 92

Platania, G., temperatures at Etna.......... 290

Platiniridium............................. 707,709

Platinum, distribution...................... 19

in igneous rocks......................... 328

ores of................................. 707-711

Plattc River, analysis of water............ 62,66,80

Plattensee, analysis of water................. 102

Plattnerite.................................. 685

Plauchud, E., reduction of sulphates by microbes ........................... 579

Playa Lakes............................... 231,505

Play fair, L., colliery gases................... 768

Pleochroic halos............................. 315

Pleonaste.................................... 338

Plombi&res, action of hot waters at, on brick.205,413

analyses of waters cited............ 205,352,353

Plumbogummito............................ 689

Plumbojarosite............................ 687,711

Plummer, G. W., pyrite and marcasite...... 330

Podolite..................................... 350

Poeschl, V., silicate fusions.................. 300

Pogue, J. E., sand barites................... 536

Poitevin, E.,and Graham, R. P. D., diamond

in chromite...................... 321

Pollard, W., uranium and vanadium in rocks. 712

See also Clough and Pollard. 

Polianite.................................... 531

Polonium................................. 308,715

Polyargyrite............................... 658,659

Polybasite................................... 658

Polydymite................................. 698

Polyhalite................................... 218

Polylithionite............................... 387

Polymethylenes............................. 724

Pomeroy, Ohio, brine....................... 178

Ponte, G. G., Etna.......................... 260

Ponteil, O. du, water analysis............... 195

Poole, H. H., radioactivity.................. 309

Popocatepetl, water from.................... 195

Popoff, L., gas from river mud.............. 737

Popoff, S. P. See Vernaclsky and Popoff.

Page. 

Popovici, Saligny, and Georgesco, water

analysis......................... 1G8

Popp, 0., boron nitride...................... 239

urao..................................... 233

water analysis........................... 105

Porcher, S., olectram........................ 648

Porlezza, C., and Norzi, G., argon and helium

in fumaroles..................... 262

Porter, F. B. See Bailey, E. H. S.

Porter, H. C., and Ovitz, F. K., gases in coal. 768

Porter, J. L., analysis of water............... 70

Porter, J. T., fuller's earth................... 503

Poscpny, F., atmospheric transport of salt... 54 

lateral secretion........................ 630,631

heavy metals in waters................ 635,638

ore deposits.............................. 629

Poscwitz, T., asphalt and petroleum......... 730

Posnjak, E., experiments on copper ores..... 657

Posnjak, E., Alien, E. T., and Mcrwin, II.

E., copper sulphides............. 664

Potaro River, analysis of water.............. 91

Potassium, distribution...................... 19

in seaweed............................... 137

proportion of, in ocean................. 130-137

Potassium nitrate. See Saltpeter.

Potassium salts, absorption by clays......... 200

Potomac River, anatysis of water..........:. 73

Potonid, H., origin of coal..................... 743

origin of petroleum....................... 742

Pougot, I., artificial pyrargyritc.............. 659

Powder River, analysis of water cited........ £6

Powcllitc.................................... 704

Power, F. D., nickel ores.................... 702

Pozzi-Escot, E., analysis by................. 161

Pozzuoli, analysis of solfatara water.......... 194

Praseodymium.............................. 19

Prascolitc.................................... 402

Pratt, J. H., chromite deposits......... 338,340,704

corundum............................... 335

gaylussite, northupito, pirssonito........ 242

occurrence of spinel...................... 338

origin of talc............................. 411

talc...................................... 6C8

See also Hidden and Pratt; Penfield and

Pratt.

Pratt, J. H., and Lewis, J. V., chromite deposits.......................... 703,7C4

Pratt, J. H., andStcrrctt, D.B., tin deposits. 6f3 

Pratt, N. A., phosphate rock................ 524

Pratt, W. E., iron ores....................... 529

Prccht, H., cited, on Stassfurt salts.......... 216

on langbeinito........................... 218

Prccht, H.; and Wittjcn, B., kieserite........ 222

Prccht, J., heat ofradium................... 207

See also Runge and Precht. 

Predazzitc.................................. 572,626

Prchnite..................................... 604

Prchnitc rock................................ 627

Preiswerk, H., sodalite trachyte............. 371

Pressure and chemical change............... 285

Prestwich, J., water in volcanism............ 279

Pretoria salt lake, analysis of water........ 169,172

Price, T., water analysis.................... 83,194

Priceite...................................... 243

Priestley, J., gases in rocks............;..... 269

Primero, Rio, analysis of water.............. 92
816 INDEX.

Page. 

Pring, ,T. N., ozone in atmosphere... -........ 44

Pring, J. N., and Button, R. S., synthetic

hydrocarbons.................... 732

See also Hayhurst and Pring. 

Prior, G. T., dundasite...................... 685

riebeckite rocks.......................... 384

teallite, etc.............................. C90

See also Hussak and Prior. 

Prior, G. T., and Spencer, L. J., cerargyritc

group............................ 660

Prismatine ................................. 377

Priwoznik, E., native iron................... 327

Prochlorite................................ 392,603

Prost, E. See Spring, W.

Proustite.................................. 658,659

Prowersose.................................. 437

Przibylla, C., formation of carnallite......... 220

Pseudoboleite............................... 686

Pscudobrookite.............................. 344

Pscudogaylussite............................ 157

Pscudoleucite................................ 366

Pseudonephelite........................ 1.... 367

Pseudowollastonite.......................... 373

Psilomclane..:.....'......................... 531

Psittacinite-................................. 689

Ptcropod ooze......................... 129,508,551

Ptilolite........'..........................'... 412

Pucherite.................................... 713

Puiggari, M;,cited....*...................... 92

Pulaskose............................. 434,444,450

Pulgar, P. del. See Calderon,C. S., etc. 

Pnmpelly, R., native copper................. 661

loess..................................... 504

sedimentation........................... 507

Purdue, A. H., phosphate rock.............. 524

Purington, C. W., Uralian platinum......... 709

Pyramid Lake, analysis of water........... 156,172

Pyrargyrite................................ 658,659

Pyrite..................................... 328-330

Pyrocatechin................................ 773

Pyrochroite.................................. 531

Pyrolusite................................... 531

Pyromorphite............................... 688

Pyrope...................................... 396

Pyrophanite.. -.............................. 344

Pyrophyllite....................... 412,488,608,614

Pyrostilpnite.. -...................:......... 658

Pyroxene.................................. 371-379

Pyroxenite............................ 378,458,459

Pyrrhotite................................. 328-330

QQuadrat, B., analysis of spinel............... 338

Quantitative classification of rocks......... 421-429

Quartz............................ 287,297,352-358

gaseous inclusions in.....^............... 269

melting point.......................... 287,288

volatility of........................... 267,288

Quartz-alunite rock.......................... 492

Quartz-barite rock........................... 584

Quartz basalt.................t.............. 452

Quartz-diaspore rock........................ 492

Quartz diorite............................... 448

Quartz monzonite........................... 446

Quartz porphyry............................ 432

Quartzine ......^........................... 352

Quartzite.................................. 609-611

Quaylc, W. 0. See Mabory and Quaylc. 

Quensel, P. D., formation of quartz and'

tridymitc...................... 287,355

Quercigh, E., lublinitc....................... 550

See also Pcllini and Qusrcigh. 

Quercylite................................... 520

Quincy mine, water from.................... ^ 181

Quinton, R., ocean water.................... 118

Quisqueite................................. 713,755

R.

Rabcn, E., nitrogen and silica in sea water... 119 

Radioactivity.......... 176,199,209,210,307-315,716

Radiolarian chert............................ 541

ooze............................... 129,508,511

Radiothoriuin............................... 309

Radium............................ 19,307,715,716

emanation............................... 19

in coal................................... 750

in rocks................................. 309

in sea water........................... 121,308

in springs.............................. 209,210

Radominsky, F., synthesis of monazitc and

xenotime......'.................. 351

Ragsky, F., analysis by..................... 188

Rainfall..................................... 50-54

Raken, M. See Cohen, E.

Rakusin, M., petroleum..................... 743

Ramage, H. See Hartley, W. N.

Ramirito.................................... 713

Rammolsberg, C., composition of tourmaline.............................. 409

Rammelsbergite............................. 698

Ramsay, Sir W., composition of the atmosphere............................ 42

sedimentation........................... 502

See also Rayleigh and Ramsay. 

Ramsay, W., and Travers, M. W., argon and

helium in minerals.............. 269

Ramsay, W. (of Helsingfors), and llliacus,

A., monazite in pegmatite....... 351

Ramsay, W., and Nyholm, E. T., cancrinite

syenite.......................... 371

Ramsay and Hunter, sintering of silica...... 358

Ramseyer, L. See Pictet and Ramseyer. 

Rangeley Lake, analysis of water............ 72

Rankin, G. A., and Morwia, H. E., iolite.... 401

See also Shepherd and Rankin. 

Ransome, F. L., alunite and diaspore...... 254,492

chert.................................... 541

enrichment of sulphides................. 643

glaucophane schist....................... 594

lawsonite................................ 407

See also Hillebrand and Ransome. 

Ransome, F. L., and Palache, C., lawsonite.. 407 

Raritan River, analysis of water............. 27

Rastall, R. H., tungsten ores................ 707

See also Hatch and Rastall. 

Rastall, R. H., and Wilcockson, W. H.,

accessory minerals in granite..... 434

Rath, G. vom, anorthite in marble.......... 625

cristobalite.............................. 3f>2

sublimed silicates........................ 268

sulphur deposits......................... 5SO

Rathite..................................... 6S4

Ravicz, L. G., secondary enrichment........ 657

Ray, J. C.,Butteores....................... 60S
INDEX. 817

o Page.

Rayleigh, Lotd, argon in springs............ 170

hydrogen in atmosphere................. 45

Rayleigh, Lord, and Ramsay, W., argon in

springs.......................... 176

Raymond, R. W., uintaito.................. 72S

Read, T. T., copper sulphide................ 665

phase rule............................... 29S

platinum................................ 711

Read, W. T., analysis by.................... 74

Reade, T. M., chemical denudation.... Ill, 113,116

Realgar..................................... C95

Reeknagel, R., origin of tin deposits......... 692

Rectorito................................:... 614

Red clay, oceanic.................. 129,130,508,510

Red Lake, analysis of water........... 160,166,170

Red River (Louisiana), analyses of water... 82 

Red River of the North, analyses of water.... 8S

Red Sea, analyses of water.................. 122

Redingtonite................................ 703

Redlich, K. A., magncsite................... 573

Rodlich, K. A., and Cornu, F., talc.......... 60S

Redlich, K. A., and Grosspietsch, O.,magnesite ............................. 572

Redwood, B.,petroleum.................. 724,741

Reese, C. L., solubility of calcium phosphate. 515 

Rcfdanskito................................. 702

Regcn River, analysis of water.............. 101

Regnault, V., oxygen of the atmosphere..... 43

Reich, A., synthesis of sillimanite........... 406

of topaz................................. 404

Sec also Stutzer, A. 

Reich, F., electrical activity in ore bodies.... G44

Reichardt, E., analysis of bittern............ 227

Rcichardtite................................ 21S

Reichort, F., Argentineborates.............. 244

Reid, C., and Scrivenor, J. B., cassiterite.... 691

Reid, J. A., mine water..................... C35

Rcid, AV. F., Argentine nitrates............. 251

Reinders, G., bog iron ore................. 528,530

Reincr, P., tourmaline...................... 409

Rcindl, J., cited............................. 90

Roinitzer, B., trona......................... 234

Reisct, J., carbon dioxide in air.............. 47

Rciter, H. II., fusion of mineral mixtures.... 300

Roilinger, J. Sec Hussak and Reitinger. 

Remingtonite............................... 701

Renard, A. F., phthanitc.................... 540

phyllites.. .............................. 617

Sec also Murray, J.

Renard, A. F., and Cornet, J., phosphorite.. 521 

Renault, B., canncl coal..................... 760

peat..................................... 752

micro-organisms in coal.................. 771

Sec also Bertrand and Renault. 

Renner, O., baeumlerite..................... 220

Rennie, K. H., vanadium in clay............ 712

Rosins...................................... 749

Republican Ri ver, analysis of water......... 81

Retgers, J. W., constitution of pyroxenes.... 379

mineralsin sand........................ 499

Renter, M. See Treadwell, F. P.

Reyor, E., volcanism........................ 2SO

Rcyes, Rio de los, analysis of water.......... 92

Rczban}^.................................. 684

Rhoineclc, H., composition of tourmaline.... 409

Rhine River, analyses of silt................. 500

analyses of water........................ 97

113750° 20 52

Page. 

Rhodium.............................. 19,328,707

Rhodium gold..................'............: 707

Rhodochrosite............................... 573

Rhodonite...........'........................ 374

Rhodose...................................... 463

Rhodusite................................... 383

Rhoenite.................................... 384

Rhone, River, analysis of water.............. 94

Rhyolite.................................. 430,431 (

fusibility................................ 293 '

Riban, J., synthesis of cerasitc..........1.... 685

Ricciardi, L., vanadium in lava............. 712

Richards, Ellen S., chlorine maps........... 53

Richards, R. H. See Day and Richards. 

Richards, T. W., isotopic lead .............. 314

Richardson, C., asphalt.................... 729,730

grahamite............................... 730

origin of petroleum...................... 744

Richardson, C., and Wallace, E. C., Texas

petroleum....................... 725

Richardson, G. B., natural gas.............. 723

sulphur deposits......................... 580

tin deposits.............................. 693

waters of Utah.......................... 153

Richardson, T., barytic deposit.............. 582

Richmond, H. D. See Pappc, A.

Richteritc................................... 379

Richthofcn, F., loess........................ 504

Rickard, E., tin deposits.................... 693

Rickard, F., tungsten ores................... 706

Rickard, T. A., precipitation of silver....... 654

solution and deposition of gold.......... 652

Rickardito.................................. 663

Ricketts, L. C.,cited........................ 161

Ricbcckitc................................ 383,384

Riedel, 0., cited............................. 216

Rickc, R., melting points of silicates......... 288

See also Endell and Rickc. 

Ricmann, C., Stassfurt salts................. 216

Ries, H., alteration of pyroxenes............. 378

clays.................................. 487,503

limestones............................... 556

peat..................................... 753

zincite................................... 678

Riess, E. R., cclogitc........................ 601

Rigaud, F., origin of coal and petroleum..... 735

Riggs, R. B., analyses by.................... 448,

504,506,575,599,611,622 

Riley, E., titanium in clays................. 495

Rimann, E., magmatic sphalerite........... 678

Rinnc, F., koencnito........................ 220

reactivity of quartz...................... 358

Rinne, F., and Kolb, R., Stassfurt salts..... 220

Rinncitc.................................... 220

Rio Grande, analysis of water............... 83

Rising, W. B. See Le Contc and Rising.

Rislcr and "Walter, Lac L<5man.............. 94

Ritom, Lac, analysis of water ............... 95

Ritter, A., nature of earth's interior......... 58

Rivas, S., cited.............................. 92

Roanoke River, analysis of water............ 73

Roberts, H. M., and Longyear, R. D., Sudbury ores........................ 700

Roberts, J. See Andcrson and Roberts.

Roberts, M. G., analyses by..... 70,72,73,74,75,79

Roberts-Austen, W. C., melting points of

minerals....................... 286,287
818 INDEX.

Page. 

Robertson, J. D., heavy metals in rocks.... 631,680

precipitated zinc sulphide................. 677

zinc deposits.......................... 68Q..682

Robinson, A. C., and Mabery, G. F., analysis

by............................... 181

Robinson, F. C., analyses of water............ 72

phosphoric acid in beryl.................. 410

Rockbridge Alum Spring, analysis.......... 193

Rock River (Illinois), analysis of water...... 78

Rock River (Minnesota), analysis of water... 77 

Rodzyanko, A., cited......................... 108

Roeblingite................................... 689

Roepperite. ................................. 385

Roeslcr, H., kaolinization.................... 487

Roessler, F., synthesis of argentite........... 655

of matildite.............................. G59

of galena and clausthalitc................ 683

Rosslcr, H.,platinum in silver bullion....... 711

Rottisite...................................... 702

Rofe, J., cannel coal......................... 760

Rogers, A. F., alterations of copper........... 663

bornite.................................. 663

corundum syenite....................... 334

covellite................................. 664

dahllite, etc............................... 519

riebeckite rocks.......................... 3S4

secondary enrichment................... 668

sericitization............................ 597

See also Tolman and Rogers. 

Rogers, A. H., and Van Wagenon, H, R.,

Chile nitrates.................... 253

Rogers, G. S., emery........................ 332

interpretation of water analyses......... 64

oil-field waters.......................... 727

petroleum............................... 726

Rogers, W. B. and R. E., solubility of minerals............................. 473

Rogue River, analysis of water.............. 86

Rohland, P., plasticity of clays.............. 437

Roloff, M., cited............................. 295

Rombnrgh, P. van, analysis by............. 192

Romeite..................................... 697

Romer, E. von, cited........................ 147

Roncegno, analysis of water from............ 184

Rondct, J., sulphosalts of lead-................. 684

Roozcboom, H. W. B., phase rule............ 298

Roscoe, H. E.,.mottramite.................... 713

Roscoelite................................. 387,714

Rose, G., fusion of limestone................ 555

synthesis of tridymi tc................... 354

uralitization............................. 598

Rose, T. E., alloys of gold and tellurium.... 649

Rcsclitc...................................... 701

Roselandose................................. 463

Roscn, F., alteration oi dolomite............ 572

Rosenbaeh, 0., volcanic nitrogen............. 267

Rosenbusch, H., chloritic substance........... 603

classification of igneous rocks.............. 421

epidotization............................ 600

garnet and prehnitc rock................ 627

glaucophane rocks........................ 384

gneiss..................................... 621

order of deposition ol minerals......... 300,467

succession of minerals in igneous rocks... 467 

venanzite............. ...................... 454

See also Hunter and Rosenbusch.

C Page. 

Rosenbuschite................................ 378

Rosenlcchcr, R., mercury deposits............ 675

Rosiwal, A., physical analysis of rocks....... 470

Ross, O. C. D., origin of petroleum.......... 736

Ross, W. S., nitrates........................ 249

R6sza, M., Stassfurt salts.................. 210,222

Rossel, H., carbide theory of volcanism...... 275

Roth, J., predazzite......................... 572

Rothpletz, A., oolitic sand................... 548

Roumania, salt lakes of...................... 168

Rousseau, G., artificial diamond............. 31D

Roux, B., water analysis.................... 164

Rowlandite................................. 720

Rubidium, distribution..................... 19

in feldspar............................... 301

in sea water.............................. 119

Rubio, C., and Marin, A., potash salts in

Spain........................... 222

Rudier, F. W., volcanoes.................... 284

Rucr, R. See Levin and Ruer.

Ruff, 0., diamond.......................... 319

iron hydroxides.......................... 529

melting point of corundum.............. 332

Rumbold, \V.. R., tin deposits............. 092,694

Rumpfite........................................ 392

Runge, C., and Precht, J., heat of radium.... 307

Ruppin, E., ocean water.................. 137,143

Russ, F., aluminum hydroxides............. 493

Russell, I. C., adobe soil-.................... 505

calcareous tufa......................... 198,548

disintegration of rocks..................... 485

gypsum.................................. 223

Lake Lahontan......................... 152,155

playa lakes.............................. 505

residual clays.......................... 504,557

Russian River (California), analysis of water. 81

Rust. See Fischer and Rust.

Ruszanda, Lake, analysis of water......... 168,173

Ruthenium.............................. 19,328,707

Rutherford, E., age of minerals.............. 311

radioactivity.................................. 311

See also Joly and Rutherford. 

Rutherford, E., and Bames, E. T., heat of

radium........................... 307

Rutile..................................... 346,347

Rutile-nelsonite............................. 483

Rutley, F., novaculite.. -.................... 540

Ryba, F., chroinite deposit.................. 704

Rzehak, A., mercury deposits............... 675

S.

Saalc, River, analysis of water............... 99

Sabatior, P., and' Senderens, J. B., synthetic

hydrocarbons.................... 732

Sacc, F., niter in Bolivia.................... 251

Sachs, A., klcinite........................... 671

Sachsse, R., water analysis.................. 164

Sacramento River, analysis of water......... 84

Sadtlcr, S. P., distillation of linseed oil...... 734

natural gas................................. 723

Saemann,. L.,. and Pisani,. F., alteration of

cancrinite......................... 371

Safflorite'.................................... 698

Safford, 3. M.., phosphorite-.................. 523

Sahrbom, N., analysis by.................... 440
INDEX. 819

Page. 

Saint-Gillcs, L. P. do. See Hautofeuillo and

Saint-Gilles. 

St. Clair, S., Sudbury ores................... 700

St. Lawrence River, analyses of water....... 70

flow of................................... 71

Saladillo, Rio, analysis of water........ 02.161,170

Salic minerals................................ 422

Salinas Eivcr, analysis of water.............. 84

Saline River, ana^is of water............... 81

Salisbury, J. H., the Dead Sea............... 165

Salisbury, R. D., mineral matter in the sea.. 125

Sec also Chambcrlin and Salisbury. 

Salite........................................ 375

Salkover, B., vanadium in manjak.......... 713

See also Clarke and Salkover. 

Salomon, W., occurrence of spinel........... 338

scapoli te................................. 400

Salsomaggiorc, water of, analysis............ 180

Salt................................... 219,223-226

Salt beds, origin........................... 212-216

Saltct, R. H., and Stockvis, C. S., cited...... 110

Saltpeter.................................... 248

Salt River,'analysis of water................. 83

Saluda River, analysis of water.............. 74

Salvador!, R., synthetic hydrocarbons....... 732

See also Nasini, R. 

Samarium................................... 19

Samarskitc................................ 713,718

Sambhar Salt Lake..................... 148,169,170

Samoilov, J. V., origin of barito, etc....... 582,583

phosphorite............................. 526

Samsonite................................... C58

Sand...................................... 497-499

Sandberger, F., analyses by................. 190

lateral secretion......................... 630

platinum in limonitc.................... 710

serpentine............................... 605

Sandstone................................. 535-540

average composition..................... 29

Sandstone reefs.............................. 536

Sanforcl, S., precipitated calcium carbonate.. 547 

San Gabriel River, analysis of water......... 84

San Joaquin River, analysis of water........ 84

San Rom&n, F. J., water analysis............ 161

Santa Ana River, analysis of water.......... 84

Santa Clara River, analysis of water, cited... 83 

Santa Maria River, analysis of water........ 84

Santa Ynez River, analysis of water......... 84

Saponite.................................... 411

Sapper, K., volcanoes of Java................ 278

Sapropel.................................. 742,748

Sarasin, E. See Friedel and Sarasin.

Saratoga waters, analyses.................... 182

Sarcolite r.................................. 394,604

Sardeson, F. W. See Hall and Sardcson. 

Sarkinfte.................................... 697

Sartoritc.................................... 684

Sartorius voa Waltershausen and Lasaulx,

A. von, Etna.................... 260

Saskatchc wan River system................. 88

Sassolite..................................... 238

Saucr, A., alteration of leucite to analcitc.... 366

graphifeoid .............................. 762

kryptotilo............................. 389,614

Saussurite................................. 403,598

Page. 

Savage, T. E., peat.......................... 753

Savannah River, analysis of water........... 74

Savu-Savu Spring, analysis of............... 181

Saxonite.................................... 458,4CO

Saytzcff, A., Uralian platinum.............. 709

Scacchi, A., fluorito on lavas................. 25C

leucite pscudomorphs................... SCO

sublimed silicates........................ 2GS

Vcsuvian sublimates.................. 266,268

Scandium................................... 19

Scapolite.............................. 399-401,600

Scapolite rocks............................ 401,600

Scarpa, 0., radioactivity of lava............. 309

Schafarak, F., the Mcdve Lake............. 169

Schafhiiutl, P., synthesis of quartz........... 353

Schallcr, W. T., analyses by............... 160,617

barbieritc................................ 359

bisbocito and shattuckitc................ 669

bismuth ocher........................... 697

dahllite and podolite.................... 350

dumortierite............................. 408

ferritungstite............................ 705

hulsitc and paigeitc- -.................... 690

ilscmannitc............................ 635,704

koechHmtc............................... 704

mclilitc group........................... 395

molybdic ocher.......................... 704

nephelitc................................ 367

tourmaline.............................. 409

trcmolito................................ 383

vanadium minerals...................... 714

warrenite................................ 684

Schaller, W. T., and Hillebrand, W. F.,

lawsonite........................ 407

See also Hillebrand and Schallcr; Hess

and Schallcr. 

Schapbachite.............................. 65S,6S4

Schardt, H., subterranean erosion........... 205

Scharizer, R., composition of tourmaline..... 409

constitution of horblcnde................ 3S2

Scheelite............................... 705,700,707

Scheercr, T., formation of dolomite.......... 559

of magnesian carbonates............. 563

Schecrerito................... J.............. 727

Schefforito................................... 374

Schenck, A., chloritization................... 003

copper ores.............................. 605

epidotization.................. 403,600,001,602

Sobering, H. G., loess....................... 504

Scherrer, J. A. See Hillobrand and Schcrrcr. 

Schertol, A., melting points of minerals...... 285

Sec also Stelzner and Schertel. 

Sohertel, A., and Erhard, T., cited......... 285

Schertelito................................... 516

Scheming, G., diamond sands............... 320

Schickendantz, F.,cited..................... 230

Schlebe, O., gold in olivine rock............. 646

Schilling, J., distribution of thorium......... 718

Scliionerer, L., and Morawsky, T., pyrocatechin from lignite............... 773

Schirmerite................................ 658,634

Schlaepfler, M., and Niggli, P., hydrothcrmal

syntheses........................ 5S9

Schlagiatweit, H. von, Tibetan borax....... 215

Schleimer, II., silicate fusions................. 303
820 IHDEX.

Page. 

Schllcrsee, analysis of water................. 96

Schlosing, C., sedimentation................. 502

Schloesing, T., ammonia in atmosphere...... 52

ammonia in sea water................... 119

analyses of sea water..................... 122

oceanic carbonic acid.................. 12G; 141

plasticity of clays........................ 497

solubility of calcium carbonate.......... 120

solubility of calcium phosphate.......... 515

tropical soils............................. 494

Schlundt, H., radioactivity of waters........ 210

bchlundt, H., and Moore, R. B., radioactivity

of waters........................ 210

Schmelck, L., analyses by................. 122,437

calcareous organisms..................... 564

marine clays............................. 137

marine muds............................ 510

Schmidt, C., chamosite...................... 577

sericitic rocks............................ 596

Schmidt, C. (Dorpat), water analyses........ 103,

122,103,166,239 

fumaroles of Monte Cerboli.............. 238

.Scbinidt, R. E. Sec Lunge, G.

Schmidt, W. B., action of sulphurous acid on

rocks............................ 478

Schiaitz, E. J., copper iu fossil wood......... 662

Scbrnutz, K. B., artificial scs polite rock..... 400

formation of tridymite................... 354

fusion of mineral mixtures............... 300

Schnarrenberger, C., analysis by............. 627

Schneoberger, P. See Oilpin and Schneoberger. 

Schneebergite................................ 097

Sclmeider, E. A., analyses by................. 202,

459,539,543,611 

augite andesite.......................... 482

See also Barus, C.; Clarke and Schneider. 

Schneider, J., water analysis................. 168

Schneider, K., origin of perofskite............ 345

Schneider, 0., rinneite....................... 220

Schneider, E., cubauite...................... 663

precipitation of silver sulphide........... 656

synthesis of cmplectite................... 667

of greenockito....................... 676

of matildite......................... 659

of wittichcnite....................... 667

Schodlcr. Se.e Petersen and Schodler.

Schoeller, water analyses...........'......... 92

Schoonito.................................... 218

Schorlomite................................. 397

Schrader, F. C., mercury deposits........... 674

Schrauf, A.,kelyphite ...................... 399

mercury ores...:...................... 67-1,675

mine waters............................. 635

serpentine from garnot................... 606

Schreibersite................................ 324

Schreinor, 0., and Failyer, 0. H., absorbent

power of soils.................... 496

See also Kahlenberg, L. 

Schreiner, O.,and Shorey, E. C., organic matter of soils....................... 106

Schrb'ter. See Friih and Schrotor. 

Schrotterite................................. 614

Schucht,F., cited............................ 500

Schuler, E.,synthesis of grcenockite......... 676

ScMler, G., chromium in a phosphate....... 520

Page. 

Schiirmann, E., corundum in basalt......... 334

precipitation of sulphides.............. 643, C44

Schiitzenberger, P., volatility of silica....... 267

Schulten, A. de, sj'nthesis of aualcitc...... 365,413

synthesis of gibbsi to................... 492,493

of lanarkite.......................... 687

oflaurionito......................... 6S6

of malachite......................... 669

of molybdenite...................... 705

of northupite and tychite............ 242

of phosgonite........................ 6S6

See also Lacroix and Do Schulten. 

Schultz, A. R.,cited......................... 161

Schultze, H., synthesis of wulfcnito.......... 087

Schulze, H., and Stelzner, A., artificial tridymite. ............................ 354

artificial willemite....................... 679

Schunett, Lake, analysis of water.......... 107,172

Schungito................................... 702

Schuster, M., fichtelito....................... 753

Schwager, A., analyses by........ 90,98,99,101,514

loess..................................... 504

river silt.............................'.... 500

Schwantke, A., artificial tridymite.......... 354

chemical system of eruptive rocks........ 421

iron in basalt............................ 324

osteolito and staflelite................... 516

Schwarz, E. II. L.. African hot springs...... 207

interior of earth.......................... 41

primitive atmosphere.................... 53

Sch war tzembergite.......................... 6S6

Schwarz, R., forms of silica.................. 353

Schwarzenbach, , the Dead Sea.......... 165

Schweidler, E. von, and Hess, V. F., heat of

radium.......................... 307

Schwcig, M., magmatic differentiation....... 306

Schwcinfurth, G., and Lcwin, L., origin of

alkaline carbonates.............. 236

Schweitzer, P., analyses by........ 179,184, ISO, 188

Schwortschlager, J., water in volcanic gases.. 278 

Scolecite..................................... 412

Scorodite as a spring deposit....'........... 203,695

Scott, A., classification of rocks.............. 418

primary analcite......................... 306

Scrivcnor, J. B., topaz-bearing rocks......... -'.05

See also Reid and Scrivenor. 

Scropc, P., volcanoes........................ 305

Seal, A. N., ozokerite........................ 728

Seamon, W. H.,analyses by................. 648

tallow clays............................. 681

Soarlesitc.................................... 242

Secondary enrichment..................... G43-645

Sedimentary rocks........................ 535-585

average composition..................... 29

volume of............................... 30,31

Sedimentation............................. 501,502

Seebach, M., native iron..................... 32-1

Seidell, A., water analysis.................. S3,154

See also Cameron and Seidell. 

Seine, River, analysis of water............... 94

Selenite. See Gypsum.

Selenium, distribution....................... 19

in mineral springs....................... ISO

Selcnsulphur............................... 265

Sclla, A., nickel iron......................... 326

Sellards,E. H.,phosphaterock.............. 524
INDEX. 821

Page. 

Sellc, V. , origin of kaolin .................... 4S7

Semper, E., and Blanckenhorn, M., origin of

nitrates.......................... 254

Semperand Michels, Chilean nitrates........ 249

Semscyite ................................... 68-1

Senarmont, H. de, precipitation of silver .... 654

reduction of copper...................... 662

synthesis of chalcopyrite................. 664

of pyrargyrite and proustito ......... 658

of pyri to. . ........................... 329

of quartz ............................ 353

ofroalgar,stibnitc,and bismuthinitc. 695 

of sphalerite .'....................-.-- 676

sulphides of cobal t and nickel ........... 699

Senarmontito. . .............................. 096

Scndcrens,J. B. S«eSabatierandSenderens. 

Serajoe River, analysis of water. ............. 104

Sericite. ................................... 3S7, 596

Serpentine .................... 393, 410, 411, C05-609

Scstini, F., solubility ofmincrals. ........... 473

Sovcrin, E. See Engler and Severin.

Sevier Lake, analysis of water. ............ 154, 171

deposits from. . .......................... 229

Scytcrtitc.. ................................. 388

Sey fort, F . , water analysis. .................. 102

Shale. ..................................... 543-546

average composition. . ................... 29, 32

Shalcr, N. S., bog iron ore ................... 528

peat. . ................................... 751

phosphorite ............................. 523

soils ..................................... 503

Shales, metamorphosed .................... 611, 612

Shand, S. J., classification of igneous rocks. 418,419 

Sharpies, S. P., coral.. ...................... 554

phosphate rock. ......................... 517

solubility of calcium phosphate .......... 515

Sharplcss, F. F. See Lane and Sharplcss. 

Shanvood, W. J., mine waters. .............. 635

tclluride gold ores . ...................... 649

Shattuckitc ................................. 669

Sheep Creek, analysis of water. .............. 88

Shclton, H. S., age of earth, etc. ........... 151, 314

Shcuandoah River, analysis of water. ....... 70

Shepard, C. U., jr., phosphate rock .......... 517

Shepherd, E. S. See Day and Shepherd. 

Shepherd, E. S., and Rankin, G. A., binary

systems of alumina, etc. ......... 286

gehlenitc ................................ 394

synthesis of corundum................... 333

of garnet ............................ 398

of mcionite .......................... 400

of sillimanitc ........................ 406

of spinel. ................................ 338

Shepherd, E. S., Rankin, G. A., and Wright,

F. E., cristobalite ............... 355

Shcrlock, R. L., dolomite... ............... 567,569

Shcrzcr, W. H., celcstite.. . .................. 581

sand ..................................... 499

Shiraz, salt lake near, analysis of water. ... 166,170

Shoal Creek, analysis of water. .............. 184

Shonkinite ................................ 436, 437

Shonkinosc. ................................. 437

1 Sborcy, E.G. See Schrcincr and Shorcy. -- 

1 Shoshonose. . ...................... 446, 450, 451, 452

Shutt, F. T., nitrogen in rain. ............... £1

Pnge.

Shutt, F. T.,and Spencer, A. G., water analysis.......... ................. 70

Sibertzew, N., soils.......................... 503

Siberian Ocean, analyses of water............ 122

Sicha, A., action of carbonated water on minerals.. ........................... 475

Sickcnbergcr, E., formation of petroleum.... 743

origin of alkaline carbonates............. 236

Sidencr,C. F., analyses of water......... 76,77,178

Siderite........................... 413,519,573-575

Siderophyllitc............................... 388

Sidot, T., synthesis of galena....;........... 683

synthesis of grccnockite and wurtzite.... 676

of magnetite......................... 3-10

of troilite................ i........... 328

ofzincite............................ 679

Siebenthal, C. E., limestone................. 556

marl..................................... 549

zinc and lead ores....................... 682

Siedcntopf, H., color of salt.................. 226

Siemens, E. W. von, volcanic explosions.... 283

Siepmann, P., constitution of coal........... 772

Siewert, M., water analysis................. 92,161

Silber, P. G.,synthesis of ncphelite.......... 368

Silica, in river waters........................ 107

in sea water........................... 119,128

volatility of........................... 267,268

Silicates, hydrolysis of....................... 189

solubility of....................... 130,473-478

Siliceous sinter.........'............... 200-202; 542

Silico-azo-humic acid....................... 106

Silicon, distribution......................... 20

Silliman, B., jr., the Dead Sea............... 165

Sillimanite........................... :. 2R7,405-407

Sillimanite schist............................ 617

Silt........................................ 499-502

Silva, A. F. de, and d'Aguiar, A., fluorine in

spring waters.................... 188

Silver, distribution.......................... 20

in native copper......................... 653

in sea water. ........................... 120

in volcanic ash .......................... 266

occlusion of oxygen by.................. 283

ores of.........................."....... 653-660

Silver Islet, analysis of water from........... 181

Silver Lake, analysis of water............. 160,172

Silver, L. P., nickel deposits................. 700

Silvestri, 0., fluid inclusion in sulphur...... 580

hydrocarbons in lava.................. 276,734

iron nitride............................ 266,267

volcanic gases........................... 260

Silvialitc.................................... 400

Silvies River, analysis of water.............. 100

Simek, A. See Jaeger and Simek. 

Simmersbach, B., and Mayr, F., nitrate deposits.. .......................... 2-19

Simpson, E. S.,latcritc...................... 4S9

native tin............................... 690

Singer, F., zeolites........................... 413

Singer, L., origin of petroleum............'... 739

Singer, M., constituents of wood............. 747

Singewa'-d, J. T., magmatic ores............. 646

titaniferous iron ores..................... 464

Singewald, J. T., and Miller, B. L., Chile ' 

nitrates.............................'. 253

silver-tin ores].......................... 694
822 INDEX.

Sinter, barytic............................ 199,582

Sinter, calcareous.......................... 198,19$

Sinter, ferruginous.......................... 574

Sinter, siliceous....................... 200-202,542

Sipocz, L., analysis by...................... 514

krennerito............................... 649

See also Locbisch and Sipocz. 

Sippy, W. L., analysis by ................... 81

Siserskite.................................... 702

Sitaparite................................... 532

Sjogren, E., bog iron ore.................... 523

fluid inclusion in sulphur................ SSO

Scandinavian iron ores.................. 464

vesnvianite.............................. 399

Sjollema, B., perehlorates in soda niter...... 2-50

Skagit River, analysis of water.............. 80

Skeats, E. M., acid water from sulphur beds. 580 

Skeats, E. W., coralline lim estone........... 553

dolomite.............................. 567,569

magnesia in coral reef.................... 567

phosphate rock........................... 520

Skey, \V., analyses by............. 179,186,199,195

awaruite................................ 325

electrical activity in ore bodies........... 644

gold sulphide............................. 647

ocean water............................. 121

precipitation of gold..................... 652

of silver sulphide.................... 658

solvents of gold.......................... 651

Skinner, \V. W., mineral springs............ 191

underground waters of Arizona.......... 191

See also Forbes, R. H.

Skinner, W. W., and Baughman, W. F., barium in natural brines............ ISO

Skutterudite................................ 693

Slate...................................... 543-546

Siichter, C. S., volume of ground water...... 34

Sloan.E., clays.............................. 503

Slosson, E. E., water analyses.............. 80,160

Smaltite..................................... 693

Smart, C., water analyses.................... 153

Smith, A. "W. See Mabery and Smith.

Smith, B. H. See Hay wood,. J. K.

Smith, C. M. See McDonnell and Smith.

Smith, E. A., phosphate rock................ 526

Smith, F. D., tungsten ores.................. 706

Smith, G. 0., molybdenite.................. 705

Smith, G. 0., and Wiliis, B., iron ores....... 529

Smith, J., river waters....................... 93

Smith, J. G., cited........................... 160

See also Failyer and Smith. 

Smith, J. L., analysis by.................. 182,325

native iron.............................. 324

Smith, J. P., ec'.ogite........................ 602

glaucophane rocks..................... 384,594

lawsonite rocks.......................... 407

Smith, N. R. See Kellerman and Smith.

Smith, R. A., oxygen of the atmosphere..... 43

peat..................................... 751

Smith, Watson, resins in lignite............. 756

Smith, W. S. T., zinc deposits................ 682

See also Ulrich and Smith. 

Smithi to.................................. 658,659

Smithsonitc............................... 678,679

Smits, A., and Endell, K., cristobalite....... 355

Smoky Hill River, analysis of water......... 81

Smolensky, G., synthesis of titanite......... 345

Page. 

Smoot, L. E., analysis by................... 193

Smyth, C. H., jr., alkaline rocks............. 441

alteration of pyroxene................. 373,374

Clinton iron ores......................... 529

corrosion of quartz..................... 358,476

limestone................................ 62G

losses of atmospheric oxygen............. 57

meliiite rocks............................ 393

metamorphosed gabbro.................. 600

solubility of rocks....................... 475

talc..................................... 411,603

Smyth, H. L., iron ores................... 341,575

Snake River, analysis of water.............. 85

Snider, L. C., zinc ores...................... 6S2

Soap Lake, analysis of water................ ICO

Soapstone................................... 603

SodaLake, sodafrom........................ 233

Soda Lakes, analyses of water............. 157,173

Sodalite........................... 268,277,369-371

Sodalite syenite....................... 371,443,4-14

Sodalite trachyte............................. 371

Soda niter............................. 242,248-253

Soddy, F., origin of helium.................. 311

Sodium, distribution........................ 20

metallic, insalt.......................... 226

sulphate deposits...................... 223-230

Sodium chloride, in rainfall.................. 53

See also Salt. 

Soellner, J., rhoenite........................ 384

Soils.......................................... 436

SokoloCf, N. V., origin of petroleum.......... 730

Sollas, W. J., chert and flint............... 541,542

geologic time.......................... 147,150

order of deposition of minerals........... 300

quartzite................................ 610

Solomon River, analysis of water............ 8.1

Soltmann, R., melanitc...................... 397

Solubility of minerals...................... 473-473

Sommerfeldt, E., classification of igneous

rocks............................ 421

Sommerlad, H., synthesis of chalcostibite.... 667

syntheses of sulphosalts................. 659

sulphosal ts of lead....................... 6S4

Sommermeier, E. E., coalanalyses.......... 755

Sonden, K.,cited............................ 51

Sonncnschein, F. L., amalgam............... 6-13

Sonstadt, E., caesium and rubidium in sea

water............................ 119

gold in sea water........................ 120

iodine in sea water...................... 113

Sorby, H. C., calcite and aragonite.......... 551

enlargement of quartz grains............. 536

formation of magnesium carbonate...... 558

of siderite and limonite.............. 573

magnesium sulphate in gypsum......... 560

shale.................................... 545

Soret's principle............................. 302

Sosman, R. B., volcanic explosions.......... 233

See also Day and Sosman. 

Souesite..................................... 328

Sowetow, S., Sea of Aral..................... 163

Spaeth, E., water analyses................ 93,99,101

Spalding, E. P., Teninguamines............ 671

Spandite.................................... 307

Spangenberg, K., synthesis of dolomite....... 559

tests for dolomite........................ 563

Spaulding, H. S., analyses by.. 76,77,78,79, SO, 82,83
INDEX. 823

Page. 

Speiiccr, A. C., Franklin zinc ores........... 682

iron ores................................ 529

magmaticwaters...................... 208,638

secondary enrichment.................. 666

Spencer, A. G. See Sliutt and Spencer.

Spencer, Herbert, nature of earth's interior. 58

Spencer, J. W., bauxite..................... 492

Spencer, L. J., jamesonite................... 684

. tellurides....................-.-...'......- 649-

See also Prior and Spencer. 

Sperry, F. L. See Penfield and Sperry. 

Sperrylite................................. 707,711

Spessartite.................................. 398

Spezia, G., effects of pressure................ 588

formation of quartz and opal............ 358

metallic sodium in salt.................. 226

solubility of quartz.................. 353,476

sulphur deposits...................... 579,580

Spbacrite.....-.-............................ 510

Sphaorocobaltite............................ 701

Sphalerite........................... 675-678,750

Spacne-..................................... 345

Spica, M., and Halagian, G., Italian waters.. 96- 

Spiegel, L., lichtelite......................... 753

Spiclmann, P., jet........................... 754

Spilker, A. See Kriimer and Spilker. 

Spinel................................... 336-332

Spirek^7 .,mercuryorcs................... 675

Spodumene......................... 375, 376, 691

Spokane River, analysis of water.. ^........ 85-

Sponges..................................... 565

Spreustein................................... 371

Spring, R., platinum ores................... 7QD

Spring, "W., argentite formed by pressure.... 655

coloration of clay....................... 504

compression of chalk.................... 554

of peat................................ 7CS

humus and iron in waters............. 502,529

precipitation of organic matter by iron.. 502 

sedimentation........................... 502

Spring, W., and Prost, E., water of the

Mouse.......................... 94,117

Spring River, zinc in......................... 184

Springs, potable, analyses of................. 65

Spurr, J. E., alaskite and tcrdri.Hite......... 430

berates.................................. 242

dolomitization.......................... 570

glauconite............................... 576

iron ores.............................. 575,576

magmatic quarts veins.................. 618

magmatic waters....................... 638

ore deposits............................. 638

primary pyrrhotito...................... 330

replacement of organic remains by silver. 653 

succession of igneous rocks................ 304

Srebenica, spring, analysis.................. 184

Stabler, H., interpretation of water analyses. 63 

river waters.............................. 68

See also Dole and Stabler. 

Stackman, A., Lake Durun................. 162

StaiTclite.................................... 516

Stahl, A. F., origin of petroleum............. 742

Pago. 

Stahl, W., on Karaboghaz................... 162

zinc sulphide............................ 670

Stanley, F. C. See Penfield and Stanley. 

Stannite..................................... 690

Stapff, F. M., bog-iron ore................... 523

Starnbergersee, analysis of water......... 96

Stassfurt salts............................. 216-223

Staurolite................................. 407,615

Steamboat Springs, analysis of.............. 182

sinter front.................... 201,650,675,690

Steatite................................... 411,600

Stecher, E., carbide theory of volcanism..... 275

Steenstrup, K. J. V., graphite in basalt..... 323

native iron............................ 32-1,323

Steidtmann, E., alteration of rocks.......... .478

dolomite......................... 561,5G2; 571

Steiger, G., analyses by.................. 87,122

159, 100, 181, 188,220, 440/443, 457, 463, 499, 

501, 504,510, 522, 525, 526, 544, 550, 560, 571, 

575, 570, 599, 609,617, 618. 

copper in lava...........;.............. 632

Mississippi silt......................... 501

solubility of minerals...................... 475

. synthetichydroearbons................. 732

See also under Clarice, Laisen, Paige, and

Watson. 

Stein, G., formation of quarts............... 355

fusion of quartz and silicates............ 288

Stein, S-, artificial coal....................... 770

Steinmann, G., precipitation of calcium carbonate. ..........'......-........ 519

Stelzner, A. W., artificial gahnitc............ 679

associates of perofskite................'... 345

Bolivian tin ores...................... 690,691

lateral' secretion....................... 630, C31

melilite rocks............................ 396

Rio Saladillo............................ 101

See also Schnlze and Stelzncr. 

Stefzner; A. W., and Bergeat, A., ore deposits. ........................ 629,646

Stelzner, A. W., and SeherteJ, A., tin in

blende......................... C90

Stelzncr, A. W., and Schulze, H., fayalitc

in slags........................ 385

St&p, J., andBecke,. F., uranium ores....... 714

Stepanow, , analysis of Trater........... 103

Stephanite................................ 658,659

Stepheasoii, E. A., analcite................. 384

chalcocite.-............................. 661

hydrothermal alterations................ 589

sohibility of minerals...................... 473

Stercorite.................................. 517

Sternbergite................................. 658

Sterrett, D. B. See Pratt and Sterrcttr. 

Stevenson, I.r primitive atmosphere......... 56

Stibiconite.................................. 697

Stibnite.................................... 694-, 696

Stieglitz, J., carton dioxide of the atmosphere. ........................... 143

Stikine River, analysis of water.............. 87

Stilbite...................................... 412

Stirpnomelane................................ 392

Stockvis, C. S. See Saltet, R. H.

Stober, F., synthesis of cotunuite-.......... 686
INDEX.

Page. 

Stokes, H. N., analyses by................... 29,65,

185,431,432,434,435,437,438,442,444,446,452,

450,459,468,539,544,556,595,613,618,622,636

formation of copper sulphides........... 666

of sphalerite......................... 681

precipitation of copper................ 661,662

of lead sulphide..................... 683

pyrite and marcasite.................... 330

solution and deposition of silver....... 654,656

solution of gold......................... 651

tallow clay.............................. 681

Stoklasa, J., volcanic nitrogen............... 267

Stolba, F., en the Moldau...................

synthesis of galena...................... ' Stolzite................................ 687,705,706

Stone, C. H., analyses of water............. 76,158

Mississippisilt........................... 501

Stone, G.H., asphalt.......................... 728

Stone, B. W.,goldin coal.............'...... 650

Stopes, M. C., and Wheeler, R. V., constitution of coal...................... 773

Storcr, F. H. See Warren and Storer.

Storms, W. H., borate deposits.............. 242

Stosc, G. \V., wavellite...................... 516

Streclcer, A. and H., marine mud............ 510

Stremme, H., allophanc, halloysite, etc...... 495

coal..................................... 748

decomposition of basalt.................. 478

humus substances....................... 479

kaolinization............................ 487

polymerization of'hydrocarbons......... 791

See also Gagel and Stremme. 

Streng, A., bauxite.......................... 491

Strengite.................................... 516

Strigovitc.................................... 392

Strombeck, A. von, electrical activity in ore

bodies........................... 644

Stromeyer, C. E., fusibility and pressure.... 285

Strorneyerite................................ 658

Strong, W. W., radioactivity.............. 308,311

Strontianite................................. 382

Strontium, distribution of................... 20

In sea water............................. 120

Strutt, R. J-, age of minerals................ 311

gases in rocks............................ 276

helium and geologic time................ 311

helium in beryl.......................... 312

helium in saline minerals................ 218

radioactivity of rocks.................. 309,310

radiumin ocean water................... 121

Struvlte..................................... 517

Stubbs, W. C., phosphate rock.............. 526

Stutzer, A., and Hartleb, R., bacterial decomposition of cement............... 480

Stutzer, A., and Reich, A., water analysis.... 164

Stutzer, O., cobalt ores...................... 698

graphite................................. 323

juvenile springs......................... 208

kaolinite................................ 487

magmatic bornite....................... 330

magnetite ores........................... 341

origin of sulphur........................ 579

primary calcite.......................... 414

sulphides in coal........................ 750

water of pitchstone...................... 279

Stutzlte..................................... 657

Page. 

Stylotypite.................................. 667

Suess, E., vadose and juvc::ile waters........ 207

volcanic additions to oceanic salts....... 139

Sussenguth, H., cited...................... 98,500

Suez Canal, analysis of water................. 122

Sullivan, E.G., copper sulphides............ 665

deposition of copper................... 069,670

of silver................................. 657

Sullivan, G. See Kastle, J. H., etc.

Sulphates, reduction by micro-organisins... 146,510

Sulphates in sea water..................... 136-137

Sulphides, solubility of.................... 633,634

Sulphoborite.............................. 220,245

Sulphohalitc................................ 242

Sulphur, distribution........................ 20

in atmosphere........................... 46

in petroleum............................ 726

native............................. 242,579,580

Sulphur Bank, analyses of waters from...... 192

Sulvanite.................................... 713

Summer Lake, analysis of water........... 159,172

Sundell, J. G., cancrinite syenite............ 331

Sundt, L., Chile nitrates:................... 253

Sungi Pait, Brook, analysis of water......... 194

Superior, Lake, analysis of water............ 70

Susquehanna River, analysis of water....... 72

Sutton, J. R., diamond...................... 320

Svanberg, , analyses by................. 709

Svanbcrgite................................. C89

Svedmark, E., uralitization................. 593

See also Torncbohm and Svedmark. 

Svendsen, S., analyses of dissolved air....... 140

Sweden, rivers of............................ 103

Swinton, A. A. C., occlusion of gases by glass. 271 

Switzerland, lakes of........................ 95

Syenite................................ 434,435,436

Syepoorite. Sec Jaipurite. 

Sylvanite.................................... 049

Sylvinite.................................... 219

Sylvite....................................... 219

Syngenite................................... 222

Syntagmatite............................... 382

Syracuse, New York, brine, analyses of...... 178

Szabo, J., primary iolito..................... 402

Szadeczky, J. von, bauxite................... 491

Szajnocha, , origin of petroleum....... 739,744

Szathmdry, L. von, wollastonitc............. 374

T.

Taal Volcano, analyses of water from........ 195

Tabbyite.................................... 727

Taber, S. See Watson and Taber.

Taboury, F., selenium in spring waters...... ISO

Tachhydrite................................. 219

Tacke B. See Minssen and Tackc.

Tagar Lake, analysis of water............. 167,171

Tahoe, Lake, analysis of water.............. 156

Takano, S. See Mabery and Takano.

Talbot, J. H. SeeBinney andTalbot.

Talc................................... 411,605-609

Tallow clay.................................. 681

Talmage, J. F., water analyses.............. 153

Tamentico, Lagoon, analysis of water...... 161,171

Tanana River, analysis of water............. 87

Tanatar, S., origin of alkaline carbonates..... 236

Taney, Lac.................................. 95
INDEX. 825

Page. 

Tantalite..................................... 71S

Tantalum, distribution of................... 20

native................................... 718

sources of.............................. 717,718

Tapajos, River, analysis of water............ 91

Tapalpite.................................... C58

Tappeiner, H., formation.of marsh gas....... 737

Tarr,W. A., barite......................... 5S4

chert.................................... 541

Tarassenko, W., constitution of feldspar..... 359

Tasmanite................................... 755

Tate, N., analysis of water. ................. 70

Taylor, F. W., analysis by................ 159,225

Taylor, H., analysis of canncl................ 759

Taylor, E. A., cited......................... 138

Taylor, W. H., analysis of water cited....... 73

Teall, J. J. H., classification of igneous rocks.. 421 

dedolomitizatiou........................ 626

differentiation........................... 305

eutcctic mixtures in rocks.............. 296,419

origin of serpentine...................... 411

phosphate rock.................... 517,518,526

phosphatizcd trachyte................... 517

the Scourio dike....................... 592,593

Tcallite.................................... 684,690

Teas, L. P., zinc ores........................ 678

Tcgernsce, analysis of water................. 96

Tchamose................................... 431

Teisseyre, W. See Mrazcc and Tcissoyrc. 

Tckir-Ghiol, Lake, analysis of water....... 168,170

Tclluridcs............. 649,657,658,663,670,683,695

Tellurium, distribution...................... 20

in copper................................ 663

in sulphur............................... 264

Temiskamitc................................ 60S

Tcngerite.................................... 720

Tcnnantito....'........................ 658,667,668

Tennessee River, analysis of water........... 79

Tcnoritc................................... 265,668

Tcphroitc................................... 385

Tcppej, G. H., monazite sand............... 351

Tcqucsquite................................. 234

Terbium.................................... 20

Tcrlinguaite................................. 670

Tcrmier, P., alunite......................... 254

lawsonite................................ 407

leverrierite.............................. 614

optical variations in zoisite.............. 402

riebeckite rocks.......................... 384

Tcrreil, A., artificial dolomite................ 559

native platinum......................... 709

water analyses........................... 164

Tesch, P..solubility of fossils................ 551

Tetlow, W. E., water analysis............... 93

Tetradymite................'................. 695

Tctrahedrite....................... C58,667,668,670

Thallium, distribution....................... 20

Thames, River, analysis of water............ 93

Than, C. von, ionic statement of water analyses............................. 60

Thenard, P., silico-azo-humic acid........... 106

Thenardite................................ 242,250

Theralite.................................... 440

Thermonatrite.. 1........................... 233

Thiele, F. C., Texas petroleum........ I..... 725

Thiene, H., nature of earth's interior........ 41,58

Page.

Thicsscn, R. See White and Thiessen. 

Thiuolitc.:..........:....................... 156

Thiophancs..........................:...... 726

Thiosulphates in spring waters.............. 190

Thoma, , gases in iron................... 282

Thomas, J. W., gases in coal....... 765,700,767,768

Thomas, P., phosphorite.................... 523

Thompson, A. B., formation of bitumens.... 743

Thomson, L, thermochemistry of sulphides... 655 

Thomson, J. A., matrix of diamond....... 320,321

Thomson, R. D., cited...................... 93

Thomsonite................................. 412

Thorianite................................... 718

Thorite...................................... 718

Thorium, distribution....................... 20

sources of................................ 718

Thorkclsson, T., hot springs of Iceland...... 258

Thornton, W. M., jr., analyses by........... 463

Thorogummitc.............................. 720

Thorpe, T. E., analyses by............ 180,182,183

Thorpe, T. E., and Morton, E. H., analysis of

sea water......................... 122

Thoulet, J., chert............................ 541

desert sand............................... 498

lakesof the Vosges....................... 94

sedimentation........................... 502

solubility of calcium carbonate. .... ..,.. 126

of silicates........................... 130

Thresh, M., manganese nodules.............. 531

Thiirach, II., occurrence of zircon and titanium minerals:................ 347,349

Thugutt, S. J., allophanc, halloysitc, etc..... 495

alteration of corundum................ 336,476

alteration of wollastonitc................ 374

cancrinite............................... 370

composition of sodalito................ 369,- 370

decomposition o f ncphclitc.............. 368

gibbsite and diasporc.................... 493

leucite and analcite...................... 364

ncphelite................................ 367

reactions of calcitc and aragonite......... 550

Thulium.................................... 20

Thuringite................................ 392,577

Tidy, C. M., water analyses cited............ 93

Tiemannite.................................. 670

Tietzo, E., atmospheric transport of salt..... 54

Tietze, 0., phosphorite...................... 523

Tilden, W. A., gases in rocks................ 269

Tillo, A. von, areas of igneous and sedimentary rocks....................... 116

Tilson, B. S.,cited.......................... 82

See also Fraps and Tilson. 

Tin, distribution............................ 20

in sinter............................... 201,691

ores.................................... 690-694

Tinetzky Lake, analysis of water.......... 163,172

Tinguaite.............................. 438,442,444

Tinstone. See Cassiteritc.

Titanito..................................... 345

litanolivine.................................. 385

Titanium, distribution...................... 21

To'rnebohm, A. E., melilite rocks............ 396

Tornebohrn, A. E., and Svedmark, E., scapolito rocks....................... 599

Tornebolim, A. S., enlargement of quartz

grains........................... 536
826 INDEX.

Page. 

Tolman, C. F., jr., oceanic carbonic acid.... 143

secondary enrichment.................. 643-

Tolman, C. F., jr., and Clark, J. D., electrolytic behavior of copper......... 645,662

Tolman, C. F., jr., and Rogers, A. F., magmatic sulphides................... 331

Tolomei, G., iron bacteria................... 528

Tombigbee River, analysis of water........... 74,75

Tonalito...................................... 451

Tonalose................................... 448,456.

Tookey, C., analyses by.................. 751,754,756

Topaz..................................... 404,405

Torbanite................................... 749

Tordrillite................................... 430

Tornoe, H., density of sea water............... 124

analyses of dissolved air................ 140,142

Torrico y Mcca, vanadium in. coaL..... ...... 713

Torrey, J. See Barbour and Torrey.

Toscanose......................... 432,433,.446,468-

Tourmaline.................................. 408,403

Tourmaline hornstone........................ C19

Tower, W. S., Chile nitrates................. 249

Trachyte.................................. 434-436

Track Lake, analysis of water................ 160

Transvaalite.................................... 701

Traphagen, W.,cited......................... 80

Traubo, H., sublimation of minerals.......... 268

synthesis of beryl......................... 410

of rutilc............................... 346

wurtzitc- as furnace product.............. 676

zincite................................... 078

See also Bourgeois and Traube. 

Traunscc, analysis of water.................. 96

Travaglia, R., formation of sulphur deposits. 579 

Travers,M. V/.,gascsfrom meteorites........ 282

gases from minerals and rocks.............. 270

Travertine............................... 198,546,548

Treadwcll, F. P., and Router,. H., solubility

of calcium bicarbonate............ 127

Trechmann, C. 0., pseudogaylussite........... 157

Tremolitc.............................. 287,.379,3SO

Troner, G. B., genesis of barito............... 584

Tridymite............................. 287,352-357

Trinkerite.................................... 755

Triphylite................................... 692

Tripoli......................................... 541

Tripuhyite................................... 697

Trobridge,. F. G., gases in coal............... 768

Troilite....................................... 328

Trona............................. 157,233,234,242

Trcost, L. See Dcville and Troost.

Troost, L., and Hauteleuille, P., gases in iron 282

Troostite.................................... G78

Truchot, P.,. monazite, thorite, and zircon... 351 

Truckce River, analysis of water............. 156

Trucman, J. D., diagnostic criteria........... 627

Tscherinak, G., alteration of atacamito....... C6S

carbon in meteorite........................ 730

constitution of pyroxenes................. 379

composition of tourmaline................ 409

gaseous occlusions......................... 282

scapolite group.......................... 400,600

serpentine................................. 605

theory of chlorites...................... 392,393

of micas............................. 389

vclcanism............................... 283

Page. 

Tschirwinsky, W., phosphorite.............. 520

podolite.................................. 350

Tsuneto, K., phosphorite.................... 526

Tucan, F., bauxite........................... 494

dolomitization............................ 501

Tucker, G. P. See Pcmbcrton, H.

Tufa, calcareous................... 156/198,546,548

Tulare Lake, analyses of water............. 158,173

Tungsten, distribution....................... 21

ores..................................... 704-707

Tungstentt'o................................. 705

Tungstic ocher............................... 705

Tuolumnose.................................. 434

Turgite....................................... 527

Turner, H. TV*., California diamonds......... 322

quartz-alunito rock..................... 254,492

Turner, H. W., and Rogers, A. F., primary

sulphides........................ 665

Turquoise..................................... 516

Turrentine, J. W., brines and bitterns..... 177,227

Tusearora sour spring, analysis.............. 193

Tyrolite..................................... 668

Tychitel..................................... 242

Tyrrell, G. W., analcitc rocks................ 366

quantitative classification of igneous 

rocks ................................. 429

Tyrrell, J. B., native iron.................... 327

Tysonitc..................................... 331

Tyuyamunite............................... 716

U.

Ubbelohde, L., optical activity of petroleum. 743 

ITdden, J. A., aerial denudation............. 135

petroleum in igneous rocks............... 636

Uglow, W. L., secondary silicates in limestone. 625 

Uhlig, J., garnet............................. 397

kornerupino........................... 377,614

kryptotile and prismatine................ 3SO

Uintaite................................... 727,72S

Ule, W., the Mansfeldcr lakes.............. 96,102

Ulexitc............................. 240,241,244,245

UIke, T., tin deposits......................./ 693

Ullik, F.,on the Elbe...................... 98,117

TJIlmannite.................................. 693

Ulrich, E.G. See Hayes and TJlrich.

Ulrich, E.G., and Smi'th, W. S. T., fluorito.. 5S5

Ulrich; G. H. F., awaruite................... 326

Umangite.................................... 063

TJmatilla River, analysis of water............ 86

TJmlauff, A. F., mercury deposits............. 674

Umpqua River, analysis of water............ 80

TJmptekose................................... 440

Unakite....................................... C01

Uralito..................................... 3SO,592

Uralitization.......................... 3SO, 592,593

Uralosc....................................... 462

Uraninlte................................. 714,715

Uranium, distribution....................... 21

ores of.................................. 712-717

See also under Radioactivity. 

Urao. See Trona. 

Urbain, G., rare earths in fiuoritc............

rare metals in blende....................

ytterbium...............................

Urbainite................................. 343,

TJrbas, M., silicate fusions...................
INDEX. 827

Page 

Urmi, Lake, analysis of water............. 1CG, 170

Urtitc....................................... 440

Urtosc....................................... 440

Uruguay River, analysis of water............ 92

silica in.................................. 107

Usiglio, J., concentration of sea water....... 213,214

Ussing, N. V., alteration of arfvedsonitc.... 3S9

Utah Hot Springs, analysis.................. 179

Utah Lake, analysis of water................ 151

Uvaldoso.................................... 454

Uvanito...\................................. 717

Uvarovito................................... 397

Vaalose...................................... 457

Vadoso waters....................:.......... 207

Valcntin, J., fluoritc......................... 585

Valentine, W., analysis by.................. 458

Valcntincr, S., cited......................... 218

Valcntinite.................................. 697

Van, Lake, analysis of water.............. 1C6,173

Vanadic ochcr............................... 713

Vanadinitc................................. 6SS, 713

Vanadium, distribution..................... 21

in bauxite............................... 712

in bitumen.............................. 713

in salt clay.............................. 217

ores of................................. 712-717

Van Hisc, C. R., actiuolite magnetite schist.. 379 

alterations of corundum................. 33G

of hematite.......................... 343

amount of carbon dioxide in atmosphere. 47 

average composition of clays, schist, etc. C22,623 

chert.................................... 542

ferruginous schists....................... 612

fineness of sand particles................. 544

formation of iron ores.................. 528,575

magmatic quartz veins.................. 648

magmatic waters........................ 638

mica schist.............................. 618

ore deposits.............................. 629

origin of magnetite...................... 341

porosity of sand......................... 536

quartzitc................................ 610

relative proportions of sedimentary rocks. 33 

volume changes in alteration of minerals................................ 588,592

volume of ground water................. 34

zinc deposits............................. 682

zones in lithospherc..................... 586

See aha Irving and Van Hisc. 

Van Hisc, C. R., and Lcith, C. K., mine

waters........................... 635

Van Horn, F. R., alkali-hornblende......... 382

Van Niiys, T. C., and Adams, B. F., cited... 47 

Van Riesen, , analysis by ................ 603

Van't Hofl, J. H., geological thermometer... 223 

on Stassfurt salts........................ 219

syntheses of borates..................... 243

Vant Hoff, J. H., and Barschall, H., on glaserite............................. 218

Van't Hoff, J. II., and Farup, P., marine

anhydrite....................... 221

Van't HorT, J. H., Kcnrick, F. B.,and Dawson, H. M.,tachhydritc.......... 220

Van't Hoff, J. H., and Meycrhoilcr, W., on

langbeinite...................... 219

Pago. 

Van't Hoff, J. H., and Wcigcrt, F., formation

of anhydrite..................... 221

Vanthoffite.................................. 218

Van Tuyl, J. H., chert....................... 511

dolomite................................. 571

oolite.................................... 551

Van Wagenen, H. R. See Rogers and Van

Wagcnen. 

Van Wagcnen, T., sodanitcr................ 253

Van Winkle, W., analyses by.............. 76,77,

78,79,80,82,83,84, 

85,80,158,159,100 

Van Winkle, W., and Eaton, F. M., waters of

California.................... 68,84,158

Variscito.................................. 516,519

Varon, G. See Hcnriot and Varon.

Varvicitc.................................... 532

Vasculose................................... 709

Vater, H., alkaline carbonates............... 236

anhydrite............................... 221.

artificial hematite....................... 342

calcite and aragonitc................... 549,550

. forms of calcium carbonate.............. 550

Vateritc....................................'. 550

Vaubcl, W., aragonitc....................... 519

Mcigen's reaction........................ 550

Vaughan, T. W., fuller's earth............... 503

precipitation of calcium carbonate....... 547

Vauquelinitc................................ C87

Vaux, F., coal analyses...... J............. 759,7CO

Veatch, J. A., boron In sea water............ 191

Vcatch, 0., bauxite......................... 492

Vegetation, as agent of rock decomposition. 478,

479 

related to precipitation of gold......... 650,052

Veins, metalliferous....................... 638-042

Vclain, C., artificial tridymito............... 354

volcanic gases........................... 202

Venable, F. P., on periodic law.............. 38

Venanzite................................... 454

Venanzoso................................... 454

Verde-antique............................... 607

Vcrmiculitc................................. 391

Vermilion................................... 671

Vcrnadsky, W., antlalnsito, kyanitc, sillimanite..................... 405,400,614,615

artificial corundum.................... 335

calcination of dumortierito............... 408

of topaz............................. 405

formation of silh'manite............ 406,614,615

of spinel............................. 338

fusion of mnscovito.................... 335,391

occurrence of native elements............ 28

rare elements in rocks................... 28

rubidium in feldspar..................... 361

Vcrnadsky, W., and Popoff, S. P., borax ... 245 

Vcrnon-Hareourt, L. V., sedimentation...... 502

Versailles alum well, analysis................ 184

Vesterbcrg, A., dolomite and magnesite..... 562

Vesuvianite............................... 399,604

Vcszelyite................................... 678

Vettcr, F. Sec Cornu and Vetter.

Vichy, spring deposits..................... 199,200

Vichy waiters, analyses.................... 180,188

Victoria Nyanza, analysis of water........... 105

Vierthaler, A., cited......................... 121

Viezzenoso................................... 440
828 INDEX.

Page. 

Vignon, L., experiments on coal............. 772

Villarello, J. D., mercury ores............... C70

Ville, L., River Ch<§lif....................... 67

Villiaumite................................".. 3G8

Vils, River, analysis of water....;........... 101

Vinagrc, Rio, analysis of water.............. 194

Viola, C., occurrence of lawsonite...;........ 407

Violette, , charcoal.................... 7C8,769

Virginia Hot Springs, analysis of water...... 188

Virginose.................................... 463

Viridite.............................'........ 603

Viry phosphatic water, analysis ............. 192

Vistula River, analysis of silt................ 500

analysis of water........................ 102

Vivianite.......................:............ 516

Voelcker, J. A., composition of apatite....... 349

Voelckeritc.................................. 519

Vogel, H., platinum in metallic ores......... 711

Vogel, 0., strontium in corals................ 581

Vogelsang, H., viridite...................... 603

Vogt, J. H. L., anorthite in slags............ 360

apatite in slag.......:................... 350

augito in slags........................... 377

bog iron ore............... 1............. 528

cassiterite as a furnace product........ 348,690

chromite deposits...................... 339,704

: distribution of the elements.:........... 28,40

of vanadium......................... 712

eutectic mixtures in rocks.............. 296,297

eutectics in classification of rocks....... 419,420

formation of hematite................... 342

of magnetite.........:............. 340,341

fusibility and pressure................... 285

fusion of garnet.......................... 397

gehlenito group........................ 354,395

ionization in magmas.................... 300

magrnatic iron ore....................... 305

magma tic pyrrhotite.................. 330,699

magmatic waters........................ 638

manganese ores.......................... 533

melting points of minerals............... 286

mica in slag............................. 389

native silver............................. 653

olivine in slags........................... 385

on assimilation theory................... 304

ore deposits.............................. 629

platinum in pyrrhotite.................. 711

solubility of sulphides in magmas..... 299,330

synthetic enstatite................ '....... 372

tin deposits.............................. 692

wollastonite in slags..................... 373

Vohl, H., water analysis..................... 97

Voit, F. W., nickel deposits................. 700

origin of diamond....................... 320

Volborthite.................................. 713

Volcanic dust and climate................... 50

Volcanic gases............................. 255-264

Volcanic explosions......................... 280-284

Volcanic mud and sand..................... 508

Volcanism, ascribed to radioactivity......... 310

hot springs and.......................... 209

Voltzite..................................... 075

Vouga, , origin of petroleum............. 741

Vrbaite...................................... 20

Pago. 

Vreclenburgite..... .v........................ 532

Vutoik, M., formation of augite.............. 378

formation of hercynite................... 338

of magnetite......................... 341

fusion of acmite......................... 375

of mineral mixtures................. 294,300

Vukits, B., formation of augite.............. 378

formation of magnetite.................. 341

of spinel............................. 338

fusion of mineral mixtures............. 294,300

W. 

Wabash River, analysis of water............ 79

Wad........................................ 531

Wade, H. R. See Failyer, G. H.

Wadsworth, M. E., chromite................ 339

native copper............................ 001

Waggaman, W. H. See Patten and Waggaman. 

Wagner, P. A., diamond.................... 320

Wagoner, L., gold and silver in deep-sea

dredgings...................... 121,047

gold and silver in rocks................ 040,047

gold in sea water...................... 120,121

Wahl, A., experiments on coal.............. 772

Wahl, W. H., composition of meteorites..... 41

Waidner, C. W., and Burgess, G. K., temperature of electric arc........... 208

Waini River, analysis of water.............. 91

Wait, C. E., antimony deposits.............. 09C

Wait, F. G., analyses by........... 88,100,181, ISO

Walchensce, analysis of water............... 00

Walden, P., origin of petroleum............. 743

Walker, P. H., analysis by..........:....... 532

Walker, T. L., magmatic differentiation..... 305

nickel deposits......................... 099,700

primary calcitc.......................... 414

tcmiskamite............................. 093

Walker Lake, analysis of water............ 156,173

Walker River, analysis of water............. 150

Wallace, E. C. See Richardson and Wallace. 

Wallace, R. C., dolomite..................... 570

gypsum and anhydrite................ 220,578

silicate fusions........................... 294

Wallace, W., sandstones..................... 539

Waller, E., analyses by.................... 153,339

Waller, S. A., and Twclvctrecs, W. H., tin

deposits......................... 091

Wallcrant, F., chalcedony................... 352

Wallieh, G. C., flint......................... 541

Walter, H. See Wegscheidcr and Walter. 

Walthcr, J., calcareous algce................. 553

criticism of Ochscuius................... 215

desertsalts.............................. 229

origin of graphite........................ 322

latcrite.................................. 488

Walthcr, P., native tantalum................ 718

Wang, Y. J., zinc ores....................... 078

Wanklyn, J. A., free iodine in spring water.. 179 

Ward, L. K., tin deposits.................... 091

Ward, W. J., analysis by.................... 754

Wardite..................................... 516

Waring, G. A., springs of California.......... 210

of Alaska..............'......,........... 211

Waring, W. G., mine waters................. 635
INDEX. 82'9

Tagc.

Warington, R., absorbent power of hydroxides............................. 496

ammonia in rainfall...................... 52

chlorides in rain......................... 53

decomposition of calcium phosphate..... 516

origin of boric acid....................... 239

sulphur in the atmosphere............... 46

Warren, C. H., anorthitc in limestone........ 362

iron-anthophyllitc..................... 379,387

mincralsin sand......................... 499

urbainite.............................. 343,464

Sec also Hidden and Warren; Johnson and

Warren. 

Warren, C. M., and Storcr, -F. H., artificial

petroleum....................... 733

Rangoon oil............................. 726

Warrcnite................................... 684

Warsaw, N. Y., brine, analysis of............ 178

Warth, H., calcium carbonate............... 549

classification of igneous rocks............ 417

gibbsite.................................. 490

Warth, H. and F. Jv latcrite and bauxite.... 490

Washington, H. S., alteration of biotitc...... 391

analcite basalt........................... 366

analcite in tinguaite..................... 366

analcite rocks ........................... 444

analyses by.................... 442,444,454,595

association of elements................... 40

average composition of ign:ous rocks..... 25

distribution of the elements.............. 40

' glaucophane rocks..................... 384,596

kaersutitc and linositc................... 384

leucite in igneous rocks................ 305,443

quantitative classification.............. 428,429

relative abundance of minerals........... 415

Washington, n. S., and Larscn, E. S., magnetite basalt................... 341,453

Washington, H. S., and Wright, F. E., carncgieite.......................... 355

See also Kunz and Washington. 

Water, influence of, on magmas............ 291,292

Water analyses, statement of................ 60-62

Watcrcc River, analysis of water............. 74

Water glass.......:.......................... 291

' Waters, classification of................ 170,177,196

Waters, J. W., radioactive minerals.......... 309

Watson, H. E., helium and neon in air...... 42

Watson, T. L., baritc........................ 584

bauxite.................................. 491

decomposition of diabase................ 483

gold insillimanite....................... 646

kragerito...........:.................... 464

manganese ores.......................... 533

nolsonite................................ 463

Virginia rutilc........................... 346

weathering of allanitc.................... 404

zinc deposits............................. 682

Watson, T. L., and Beard, R. E., colors of

quartz........................... 352

Watson, T. L., and Hess, F.L., zirconifcrous

sandstone........................ 349

Watson, T. L., and Steigcr, C., corundum

spinellite.................... 464

Watson, T. L.,andTaber, S.,nclsonitc...... 347

Watts, W. L., waters accompanying petroleum -.'......................... 741

Wavcllite.................................... 516

Way, J. T., absorption of potassium by soils. 496 

Waync, E. S., analysis by................... 179

Weathering, belt of.......................... 5S7

Weber River, analysis of water.............. 154

Websky, J., analyses of peat................. 750

gasfrorn peat............................ 765

Webskyite................................... 411

Webstcrite............................ 37cS, 458,459

Websterosc.................................. 459

Wedd, C. B., barytic sandstones............. 5'J7

Wedd.C. B., and Drabble,G.C., fluorspar... 585 

Wedding, H., and Fischcr, T., gases in iron.. 282 

Weed, W. H., copper ores................... 665

gold in igneous rocks..................... 328

iron sinter............................... 574

on siliceous sinters..................... 201,202

ore deposits............................ 629,643

secondary enrichment................... 643

tin deposits.............................. 633

travertine............................. 198., 548

Weed, W. H., and Pirsson, L. V., alteration

of leucite to analcite.............. 366

origin of corundum...................... 335

orpiment and realgar.................... C95

Weed, W. H., and Spurr, J. E., ore deposits. 629 

Weeks, F. B., tungsten ores................. 706

Weeks, J. D., manganese deposits........... 533

Wcems, J. B., lead and zinc in limestones.... CSO

Wegcner, A., composition of atmosphere..... 42

Wegscheider, R., and Walter, H., gaylussito

and pirssonitc................... 242

Wchrlitc................................... 459,695

Wchrlosc.................................... 459

Weibull, M., formula of iolite................ 401

manganese in spring water............... 200

vcsuvianitc:............................. 399

Wcidman, S., clays.......................... 502

iron ores................................. 575

Weigand, B., serpentine..................... 605

Wcigel, O., solubility of sulphides........... 634

Weigert, F. Sec Van't Hoff and Weigert. 

Weingarten, P. Sec Jannasch and Wcingartcn. 

Weinschenk, E., constitution of pyritc...... 330

garnet group............................ 397

nickel ores............................. 699,700

nontronite............................. 480,487

origin of graphite...................... 322,323

serpentine............................... 605

synthesis oi apatite...................... 350

oi argcntitc.......................... 655

of chalcocite and covcllitc........... 664

oi cinnabar.......................... 672

of galena............................ 683

of orpiment and stibni tc............. 695

talc pseudornorphs...................... 608

Wciss, F., origin of kaolin................... 482

Wciss, K. E.,chromito deposit.............. 704

Weisswasscr, analysis ol water.............. 99

Wcith, A.' J., analyses by.................... 81

Weld, C. M., iron ores....................... 529

Wellcome, H. S., analysis of salt............. 225

Wellcr, A., nitrogen In petroleum........... 726

Wells, G. M., phosphate rock................ 524

Wells, H. L., spcrrylitc... ................... 711
830 INDEX.

Page.

"Wells, H. I/., and Pcnfield, S. L., sperrylitc. 711 

Wells, J. W., arsenic mine................... 697

molybdenite............................ 705

Wells, B.C., carbon dioxide in sea water.... 127

copper in lava........................... 632

electric potential of ores................. 644

mine waters........................... 635,636

palladium in plumbojarositc............. 711

precipitation ol sulphides................ 644

solubility of carbonates................ 127,645

tungstenite.............................. 705

vanadium in asphalt.................... 713

Wellsitc..................................... 412

Wclsbach, Auer von, ytterbium............. 21

Wendeborn, , mercury deposits.......... 674

Wendt, A. F., tin deposits.................. 694

Wcrling, P., loess........................... 504

Wcrner and Fraatz, samsonite............... 658

Werneritc................................... 399

Wcrvekc, L. van, occurrence of chloritoid... 391 

iron ores................................. 577

Weser River, analysis of water.............. 102

Westgatc, L. G., epidotc-quartz rock........ 601

metamorphosed limestone............... 620

Westphal, J., cited, on Stassfurt salts........ 216

West Baden Spring, analysis................ 185

Wcthcred.E. B.,oolite...................... 548

Weyberg, Z., synthesis of acmitc ............ 376

of sodalite........................... 370

the silicate K2Al2Si06 ............... 382

Wheeler, A. S., analyses of sea water........ 122

Wheeler, H. A., blende in lignite............ 679

clays.................................... 503

lead silicate............................. 689

See also LuedekLag and Wheeler. 

Wheeler, R. V. See under Burgess, Clark,

Jones, and Stopes. 

Wheeler, W. C., analyses by........... 511,521,522

Sec also Clarke. and Wheeler. 

Wherry, E. T.,carnotite..................... 716

See also Larsen and Wherry. 

WhewcllitC................................... 749

Whipple, G. C,, and Jackson, D. D., chlorine

maps............................ 53

Whitby well, analysis....................... 181

White, A. F., chemical denudation.......... 112

White, C. J., ocean xvater.................... 121

White, D., petroleum...................... 727,745

White, D., and Thiessen, R., origin of coal.. 748,

756,771 

White, I. C., grahamite...................... 728

White, J., barium in artesian, water.......... 200

White, W. P. See Alien and White. 

Whitehead, W. L. See Lindgren and Whitehead. 

White Island hot lake, analyses of water..... 195

White River, analysis of water.............. 79

White Sea, analysis of water................. 122

Whitfield, J. E., analyses by.... 80,198,200,201,202,

203,431,448,459,574 

Whitman, A. R., origin of pyrito ............ 330

Whitney, J. D., zinc deposits................ 682

Whitneyitc.................................. 663

Whittle, C. L.,ottrcliteschist............... 616

Wibcl, E., cited............................. 121

Page, 

Wichmann, A., alteration of iolitc............ 402'

glaucophane rock........................ 594

minerals in sand......................... 498

scricitic rocks............................ 593

Wiegand, E. See Beilstein and Wiegand. 

Wieland, G. R.,siliceous oolite.............. 512

Wiesbaden, analysis oi water................ ISO

Wieslcr, A., gold in sea water................ 121

Wiesner, G. H., nitrogen and chlorine in rain. 51 

Wilcockson, W. E:. See Rastall and Wilcockson. 

Wilder, F. A.,gypsum...................... 226

Wilkc, E., rubidium in potash salts......... 218

Wilkinson, C., precipitation of gold.......... 652'

Will, W., and Pinnow, J., diamonds in

meteorite........................ 319

Willamcttc River, analysis of water......... 85

Willernite............................. 678,679,032

Williams, A., gold sulphide................. 647

Williams, C. P., zinc in waters............ 185,636

Williams, F. H., hydrocarbons in iron..... 730,731

Williams, G. F., matrix of diamond......... 320

Williams, G. H., allanito and cpidotc........ 404

chloritization............................ COS

corundum, emery, and spinel............ 335

cpidotization.......................... 600,601

occurrence of magnetite.........:........ 341

of perofskitc......................... 345

of spinel............................. 338

picdmontitc in rhyolitc.................. 403

saussuritc rocks ...................... 403,508

sericitization............................ 59G

serpentine from pcridotitc............... 411

uralitization............................. 592

Williams, I. A., clays........................ 503

micrometric analysis of rocks............ 470

Williams, J., cited........................... 52

Williams, J. F., bauxite..................... 493

pscudoleucite............................ 3S6

See also Brackett and Williams. 

Williams, K. See Ebaugh and Williams. 

Williamson, E. D. See Johnston et al. 

Willis, B., cited............................. 5!9

Willis, J. L., phosphate rock................ 519

Willin, E., analyses by..................... 109,190

See also Jacquot and Willm. 

Willyamite.................................. GOO

Wilm, , palladium gold.................. 648

Wilmington Lake, analysis of water....... 160,173

Wilsmore, N. T. M. See Craig, A. W.

Wilson, M. E., magnesite.................... 573

Wiluite...................................... 399

Winchell, A., cosmical atmosphere.......... 55

Winchell, A. N., chalcopyrito and bornitc... CC3 

classification of igneous rocks............ 418

origin of graphite........................ 323

Winchsll, H. V., chalcocite.................. 065

Winchell, N. H., silicated iron ores.......... 576

Winchell, N. n. and H. V., iron ores........ 575

Winchester, D. E., oil shale................. 749

Winkler, C., origin of nickel-iron............. 325

trona.................----............... 234

vanadium in coal........................ 717

Winklcr, L. W., iodine in sea water......... 113

Winnemucca Lake, analyses of water...... 156,173
INDEX. 831

Pago. 

Winslow, A., zinc ores..................... 680,082

Wisconsin River, analysis of water.......... 77

Witt, H. M., river water..................... 93

Witter, F. M., gas well...................... 737

Wittich, E., cassiterite...................... 091

Wittichenite................................ G67

Wittjcn, B. See Prccht and Wittjcn.

Wittstein, G., water analysis................ 101

Woehler, F., carbon in meteorites........... 73G

gases from meteorites.................... 2S2

synthesis of pyrite....................... 328

See also Devillc and Wohler. 

Woollier, £., and Kasarnowski, color of salt.. 220 

Wohlcrito................................... 378

Woernitz, River, analysis of water........... 101

Wolf, T., volcanic gases..................... 261

Wolfachite.................................. 638

Wolfbauer, J. F., water of the Danube.. 101,102,500 

Wolff, F. von, volcanism and radioactivity.. 310 

Wolff, J., artificial diamond................. 318

waters of Mecklenburg................... 102

Wolff, J. E., Franklin zinc ores.............. 682

ottrelite................................. 616

Wolframite................................ 705,703

Wollastonito...................... 287,288,373,621

Wollastonito gneiss.......................... 627

Wollc, C. A., analysis of spinel.............. 333

Wologdino, S. See Le Chatelier and Wologcline. 

Wood..................................... 746,763

Wood, A. See Campbell and Wood.

Woodward, R. S., geodetic data............. 22

Woodward, R. W., analyses by............. 155,

198,201,230,232,543 

Woolnough, W. G., laterite.................. 489

Wootcn. See Magucnat and Wootcn.

Workman, R., primary calcite............... 414

Woyno, T. J., glaucophane schists........... 594

Wright, A. W., gases from meteorites........ 2S2

gases in rocks............................ 269

See also Hawes and Wright. 

Wright, F. E., crystallized copper and silver.. 662

Sec also Alien, E. T.; Hillebrand, W. F.;

Shepherd, E. S. 

Wright, F. E., and Larscn, E. S., quartz as

geological thermometer.......... 355

Wroczynski, A. See Brincr and Wroczynsld. 

Wiilfing, E. A., composition of tourmaline... 409 

Wiirmsee, analysis of water.................. 90

Wtist, E., kaolin............................ 487

Wulf, H., scapolito rock..................... 000

Wulf, J., Wollastonito rock................... 374

Wulfcnite..................................087,704

Wurtz, H., analysis of water cited........... 71

huntilite and animikitc.................. 054

solvent of gold........................... G51

Wurtzilito................................... 723

Wurtzito.................................. 675-678

Wyatt, F., phosphates...................... 523

Wyomingite................................. 442

Wyomingose................................ 442

Wyrouboff, G., Moigcn 's reaction............ 550

Wysor, D. C., bauxite....................... 493

X. Page, 

Xanthitane................................ 345,49J

Xanthoconitc................................ 653

Xanthophyllitc............................... 333

Xanthosiclerite.............................. 527

Xenon.................................. 21,42,176

Xenotime................................. 351,719

Xingti, River, analysis of water.............. 91

Yakima River, analysis of water............. 85

Yamasaki, W., piedmontitc................. 403

Yamashita, Y., and Majima, M., melting

points of minerals............... 230

Yancey, II. F.,ilsemannitc................ 635,701

Yeatcs, W. S., copper pseudomorphs........ GGl

Yellowstone National Park, analyses of waters. ........................ 80,183,190

spring deposits............ 193,200,201,202,203

Ycllowstonose............................... 448

Yeniseisk, Siberia, saline lakes .............. 107

Yogoite..................................... 41C

Young, A. A., enlargement of quartz grains.. 530 

Young, B. R., analcitc diabase.............. 3CG

Young, G. J., salines of Great Basin......... 230

Young, G. See Irvine, R.

Young, J. W., silver halidcs................. GOO

Young, S. W., and Moore, N. P., secondary

enrichment...................... CCG

Ytterbium................................... 21

Yttrialite................................. 313,720

Yttrium, distribution........................ 21

sources of................................ 719

Yttrocerite.................................. 331

Yttrocrasitc................................. 720

Yukon River, analysis of water.............. 87

Zaleski.S.S., cited.......................... 103

Zalinski, E. R., thuringitc ajid chamosite.... 577

Zaloziecki, R., formation of petroleum....... 740

mirabilite............................... 222

Zaloziecki, R., and Hausmann, J., Roumanian petroleum.................. 725

Zaloziecki, R., and Klarfeld, H., optical activity of petroleum.............. 713

Zambonini, F., age of earth.................. 313

akerrnanite.............................. 394

gohlenite group.......................... 394

molybdosodalitc......................... 309

pseudonephelite......................... 307

sublimed galena......................... 200

Zaracristi, , Colombian nitrates.......... 2 jl

Zaratite..................................... 701

Zeiller, R., compression of peat.............. 703

paper coal............................... 750

Zelinsky, N., cited.......................... 110

Zemcuzny, S.,eutectics...................... 419

Zemjatschensky, P. A., hydrogoethite....... 527

Zem-zem, analysis of water.................. 192

Zeolites................................ 303,412,413

Zepharovichite.............................. 510

Zics, E. G., Alien, E. T., and Merwin, H. E.,

secondary enrichment........... 606
832 INDEX.

Pago. 

Zietrisikitc.................................. 727

Zillaruello, A., Chilean nitrates.............. 250

Zilliacus, A., analysis by..................... 440

Zinc, distribution........................... 21

in river water............................ 184

in sea water............................... 120

ores of.................^............... 675-687

Zincaluminite............................... 678

Zincite................................ 678,679,682

Zinkeuite.. -................................. 684

Zinnwaldite....................... 387,388,391,692

Zircon............................. 269,348,349,718

Zircon pyroxenes.......................... 378,718

Page.

Zirconiferous sandstone...................... 349

Zirconium, distribution...................... 21

sources of................................ 718

Zirkel, F., ottrelite and chioritoid........... 616

Zitowitsch, , gases in coal................ 765

Zoisite................................... 402,403,604

Zoisite rocks................................. 599

Zorgite...................................... 683

Zschiramer, E., alteration of micas........... 392

Zuber, E,., origin of petroleum............... 738

Zulkowski, K., andalusite group............. 403

Zurich, Lake of, analysis of water............ 97

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