DEPARTMENT OF THE INTERIOR

UNITED STATES GEOLOGICAL SURVEY

GEORGE OTIS SMITH, DIRECTOE

BULLETIN 491

THE

DATA OF GEOCHEMISTRY

SECOND EDITION

BY 

FRANK WIGGLESWORTH CLARKE

WASHINGTON

GOVERNMENT PRINTING OFFICE 

1911

CONTENTS.

Page.

Introduction.............................................................. 9

CHAPTER I. The chemical elements.......................................... 12

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

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

Relative abundance of the elements.................................... 21

The periodic classification.............................................. 34

Meteorites.........................................................'.... 38

CHAPTER II. The atmosphere............................................... 40

Composition of the atmosphere......................................... 40

 The relations of carbon dioxide to climate............................... 46

Rainfall............................................................... 48

The primitive atmosphere.............................................. 52

CHAPTER III. Lakes and rivers............................................. 56

Origin................................................................ 56

Statement of analyses................................................... 57

Springs.................. .(........................................... 59

Changes of composition................................................ 60

Analyses of river waters................................................. 63

The St. Lawrence basin............................................. 64

The Atlantic slope................................................. 66

The Mississippi basin.............................................. 69.

Southwestern rivers............................................... 76

Northwestern rivers............................................... 77

Rivers of California................................................ 78

The Saskatchewan system.......................................... 80

Summary for North America....................................... 81

Rivers of South America............................................ 82

Lakes and rivers of Europe.......................................... 84

Rivers of India and Java............................................ 96

The Nile.......................................................... 96

Organic matter in waters............................................... 97

Contamination by human agencies....................................... 99

Gains and losses in waters.............................................. 100

Chemical denudation.................................................. 102

CHAPTER IV. The ocean.................................................... 109

Elements in the ocean.....'............................................ 109

Composition of oceanic salts............................................. 112

Carbonates in sea water................................................ 117

Oceanic sediments..................................................... 119

Potassium and sulphates............................................... 127

The chlorine of sea water.............................................. 128

The dissolved gases.................................................... 130

Influence of living organisms............................................ 136

Age of the ocean...................................................... . 137

3

140210
4 CONTENTS.

Page.

CHAPTER V. The waters of closed basins.................................'... 143

Preliminary statement.................................................. 143

The Bonneville basin.................................................. 143

The Lahontan basin................................................... 146

Lakes of California.................................................... 149

Northern lakes.......................................................J. 151

Central and South America............................................ 153

Caspian Sea and Sea of Aral............................................ 153

The Dead Sea.................................................'........ 155

Other Russian and Asiatic lakes..:..................................... 157

Miscellaneous lakes.................................................... 160

Summary.............................................................. 162

CHAPTER VI. Mineral wells and springs..................................... 168

Definition............................................................ 168

Classification.......................................................... 169

Chloride waters....................................................... 170

Sulphate waters....................................................... 176

Carbonate waters. ............I........................................ 179

Waters of mixed type.................'................................. 181

Siliceous waters........................................................ 182

Nitrate, phosphate, and borate waters.................................... 185

Acid waters............................................................ 187

Summary of waters. ................................................... f 190

Changes in waters..................................................... 191

Calcareous sinter...................................................... 192

Ocherous deposits..................................................... 193

Siliceous deposits...................................................... 194

Reactions with adjacent material....................................... 198

Vadose and juvenile waters............................................. 201

Thermal springs and volcanism......................................... 202

Bibliographic note..................................................... 204

CHAPTER VII. Saline residues.............................................. 206

Deposition of salts....................................................... 206

Concentration of sea water.............................................. 207

The Stassfurt salts.........................................:............ 210

Other salt beds........................................................ 217

Analyses of salts........................................................ 219

Analyses of gypsuni.................................................... 220

Bitterns.:............................................................. 220

Sodium sulphate...................................................... 222

Miscellaneous desert salts.............................................. 224

Alkaline carbonates................................................... 225

Borates............................................................... 231

Nitrates.............................................................. 241

The alums.............................................................. 246

CHAPTER VIII. Volcanic gases and sublimates................................ 248

Gaseous emanations................................................... 248

Sublimates............................................................ 256

Occluded gases........................................................ 260

Volcanic explosions.................................................... 271

Summary........................................'....................... 275

CHAPTER IX. The molten magma........................................... 277

Temperature........................................................... 277

Influence of water...................................................... 282
CONTENTS.

CHAPTER IX. The molten magma Continued.

Magmatic solutions..................................................... 283

Eutectics.............................................................. 286

Separation of minerals.................................................. 290

Differentiation......................................................... 293

Radioactivity......................................................... 298

CHAPTER X. Rock-forming minerals......................................... 305

Preliminary statement.................................................. 305

Diamond and graphite.................................................. 306

Native metals.......................................................... 311

Sulphides............................................................ 316

Fluorides.............................................................. 318

Corundum............................................................. 319

The spinels........................................................... 324

Hematite.............................................................. 329

Titanium minerals..................................................... 330

Cassiterite and zircon ................................................. 335

Phosphates........................................................... 336

The silica minerals.................................................... 339

The feldspars......................................................... 345

Leucite and analcite.................................................. 350

The nephelite group.................................................... 353

The cancrinite-sodalite group........................................... 355

The pyroxenes......................................................... 357

The amphiboles....................................................... 364

The olivine group..................................................... 369

The micas............................................................. 372

The chlorites......................................................... 377

The melilite group.................................................... 378

The garnets........................................................... 380

Vesuvianite........................................................... 383

The scapolites........................................................ '383

lolite................................................................. 385

The zoisite group...................................................... 386

Topaz................................................................ 388

The andalusite group................................................... 389

Staurolite...........................:.......'.......................... 390

Lawsonite............................................................ 391

Dumortierite.......................................................... 391

Tourmaline............................................................ 392

Beryl.................,..........:...............................:... 393

Serpentine, talc, and kaolinite.......................................... 394

The zeolites.......................................................... 395

The carbonates...............'......................................... 396

CHAPTER XI. Igneous rocks............................................... 398

Preliminary considerations. .............................................. 398

Classification.......................................................... 399

Composition of rocks.................................................. 411

The rhyolite-granite group......................................... 412

The trachyte-syenite group ......................................... 416

Nephelite rocks................................................... 420

Leucite rocks...................................................... 424

Analcite rocks..................................................... 426

The monzonite group.............................................. 428
6 CONTENTS.

CHAPTER XI. Igneous rocks Continued. Page. 

Composition of rocks Continued.

The andesite-diorite series........................................... 430

The basalts........................................................ 434

Diabase........................................................... 437

The gabbros....................................................... 439

Femic rocks........T.............................................. 440

Basic rocks....................................................... 443

Limiting conditions................................................... 445

Proximate calculations................................................. 448

CHAPTER XII. The decomposition of rocks................................. 452

The general process................................................... 452

Solubility of minerals................................................. 454

Effects of vegetation................................................... 459

Influence of bacteria................................................... 460

Influence of animal life................................................ 461

Products of decomposition.............................................. 462

Rate of decomposition.................................................. 466

Kaolin................................................................ 468

Laterite and bauxite................................................... 469

Absorption..........................................................: 477

Sand................................................................. 478

Silt................................................................... 480

Glacial clays.......................................................... 483

Loess.................................................................. 485

Marine sediments,..................................................... 487

Glauconite............................................................ 492

Phosphate rock........................................................ 495

Ferric hydroxides..................................................... 504

Manganese ores....................................................... 508

CHAPTER XIII. Sedimentary and detrital rocks.............................. 513

Sandstones........................................................... 513

Flint and chert........................................................ 518

Shale and slate........................................................ 521

Limestone............................................................ 524

Dolomite.............................................................. 534

Iron carbonate........................................................ 545

Silicated iron ores...............................................'....... 547

Gypsum............................................................... 550

Native sulphur........................................................ 550

Celestite............................................................... 552

Barite................................................................. 553

Fluorite............................................................... 555

CHAPTER XIV. Metamorphic rocks.......................................... 557

Metamorphic processes................................................ 557

Classification.......................................................... 561

Uralitization.......................................................... 563

Glaucophane schists.................................................... 565

Sericitization......................................................... 566

Other alterations of feldspar........................................... 568

Chloritization........................................................ 573

Constitutional formulae.................................................. 574

Talc and serpentine.................................................... 575

Quartzite............................................................ 579
CONTENTS. . 7

CHAPTER XIV. Metamorphic rocks Continued. Page.

Metamorphosed shales................................................. 581

Ferruginous schists................................................... 582

Dehydration of clays.................................................. 583

Mica schist............................................................ 587

Gneiss............................................................... 591

Metamorphic limestones................................................ 593

Diagnostic criteria..................................................... 597

CHAPTER XV. Metallic ores................................................ 599

Definition............................................................. 599

Source of metals...................................................... 600

Gold................................................................. 613

Silver................................................................. 619

Copper................................................................ 625

Mercury............................................................. 633

Zinc and cadmium.................................................... 638

Lead................................................................. 645

. Tin.....................-.......................-.......-------------- 652

Arsenic, antimony, and bismuth. ..........................- - 656

Nickel and cobalt...................................................... 660

Chromium........................................................... 664

Molybdenum and tungsten............................................. 666

The platinum metals.. ................................................. 668

Vanadium and uranium................................................ 672

Columbium, tantalum, and the rare earths............................... 678

CHAPTER XVI. The natural hydrocarbons.................................. 681

Composition.......................................................... 681

Syntheses of petroleum................................................ 690

Origin of petroleum.................................................... 693

CHAPTER XVII. Coal...................................................... 705

Origin of coal.......................................................... 705

Peat.................................................................. 708

Lignite.............................................................. 711

Bituminous coal...................................................... 716

Anthracite...................... 1.................................... 718

The variations of coal.................................................. 721

The gases in coal..................................................... 723

Artificial coals....................................................... 726

The constitution of coal................................................ 729

INDEX. ................................................................... 733

THE DATA OF GEOCHEMISTRY.1

By F. W. CLARKE.

INTRODUCTION.

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

Ocean and the atmosphere, about eighty chemical elements are now 

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

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

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

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 seems 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 already known. 

The rarest substances, however, whether elementary or 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.

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 less impure; but most rocks are mixtures of species, in which, 

either by the microscope or by the naked eye, the individual components 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

i The first edition of this volume was published in 1908 as Bulletin 330 of the United States Geological 

Survey. The work has been revised and enlarged for the present edition.

9
10 THE DATA OF GEOCHEMISTRY.

rock, for example, may be composed mainly of eight chemical elements, 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 niterpenetrate 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
INTRODUCTION. . 11

second and third shells are relatively thin, and consist of material 

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 been a loss of salts leached out into the ocean, 

but ohe 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 ib 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 twenty-five 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.

i The recent Principles of chemical geology, by J. 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 are 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. l£ 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 nebulae 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, radio thorium, ionium, etc., are also disi F. W. Clarke, Pop. Scl. Monthly, January, 1873. See also the later well-known speculations of J. 

Norman Lockyer.

«This subject will be discussed at length later. 

12
THE CHEMICAL ELEMENTS. 13

regarded for the reasons that they are imperfectly known and geologically unimportant. The recently discovered celtium, and niton, 

the emanation of radium, are too little known to be included here.

The chemical elements.

Arsenic.............

Bismuth............

Boron..............

Cadmium...........

Csesium ............

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

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

Chlorine...........

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

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

Dysprosium........

Erbium............

Fluorine............

Gadolinium.........

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

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

Lanthanum...... . .

Lead...............

Magnesium. .......

Symbol.

Al 

Sb 

A 

As 

Ba 

Bi 

B 

Br 

Cd 

Cs 

Ca 

C

Ce 

Cl 

Cr 

Co 

Cb 

Cu

%

Eu 

F 

Gd 

Ga 

Ge 

Gl 

Au 

He 

H 

In 

I 

Ir 

Fe 

Kr 

La 

Pb 

Li 

Lu 

Mg 

Mn 

Hg

Atomic 

weight.

27.1 

120.2 

39. 88 

74.96 

137. 37 

208.0 

11.0 

79.92 

 112. 40 

132. 81 

40.09 

12.00 

140. 25 

35.46 

52.0 

58.97 

93.5 

63.57 

162. 5 . 

167.4 

152.0 

19.0 

157.3 

69.9 

72.5 

9.1 

197.2 

3.99 

1.008 

114.8 

126. 92 

193.1 

55.85 

82.9 

139.0 

207. 10 

6.94 

174.0 

24.32 

54.93 

200.6

Nickel.............

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

O WCTPTI

Potassium..........

Praseodymium......

Rubidium..........

Samarium..........

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

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

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

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

Strontium..........

Tellurium..........

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

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

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

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

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

Ytterbium 

(Neoytterbium)..

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

Symbol.

Mo 

Nd 

Ne 'Ni 

N 

Os 

0 

Pd 

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 

TJ 

V 

Xe

Yb 

Yt 

Zn 

Zr

Atomic 

weight.

96.0 

144.3 

20.0 

58.68 

14.01 

190.9 

16.00 

106.7 

31.04 

195.2 

39.10 

140.6 

226.4 

102.9 

85.45 

101.7 

150.4 

44.1 

79.2 

28.3 

107. 88 

23.00 

87.63 

32.07 

181.5 

127.5 

159. 2 

204.0 

232.4 

168.5 

119.0 

48.1 

184.0 

238.5 

51.06 

130.2

172.0 

89.0 

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.

i For an early table showing distribution, see 1-Slie de Beaumont, Bull. Soc. gfiol. France, 2d ser., vol. 4, 

1846-47, p. 1333,
14 THE DATA OP GEOCHEMISTRY.

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

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 

oxide 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. An 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 

sulpharsenicles 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. 

i 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 sulphobLsmuthides, and 

the telluride, oxide, carbonate, vanadate, and arsenate exist as relatively rare mineral species.

i 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 or 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 generally 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

Csesium. 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. AEL essential constituent of many rock-forming 

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

the pyroxenes, and scapolite. 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 once been identified in a meteorite.

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 aUanite, are all that need be 

mentioned here.

Chlorine^ The 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, tantalite, 

and samarskite being typical examples. All these minerals are 

most abundant in pegmacite veins.

i Also known as "niobium." The name columbium has nearly 40 years' priority.
16 THE DATA OF GEOCHEMISTBY.

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 

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.

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 hi 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 highly crystalline uraninite found 

in pegmatite. The massive mineral from metalliferous veins contains little or no helium. Trades 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.

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
THE CHEMICAL ELEMENTS. 17

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.

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

jron 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, limonite is a hydroxide, pyrite and marcasite are sulphides, siderite is 

the carbonate, and there are also many silicates, phosphates, arsenates, 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 quantities in the atmosphere.

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

associated with cerium, q. v.

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 a vanadate. Galena 

is frequently associated with pyrite, marcasite, and sphalerite.

Lithium. One of the alkaline metals. Traces of it are found 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 "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 magnesium silicates, and 

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

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 

101381° Bull 491 11 2
18 THE DATA OF GEOCHEMISTRY.

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

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

the hydroxide, psilomelane, 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 

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, 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 

josephinite. 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.

Nitrogen. The predominant element of the atmosphere, hi which 

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

derived substances as coal. Nitrates are 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 

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.,
THE CHEMICAL ELEMENTS. 19

and generally uncombined. To the latter statement there are two 

known 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 Kambler 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. 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.

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

i Proc. Eoy. Soc., vol. 77, ser. A, 1906, p. 472.

zSitzungsb. Berlin Akad., 1908, p. 851. See also a later paper in Chem. News, vol. 102,1910, p. 211.
20 THE DATA OF GEOCHEMISTRY.

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 tellurates 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.

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-earth 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 

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.1 Its commonest occuri F. P. Dunnington (Am. Jour. Sci., 3d ser., vol. 42, 1891, p. 491) has shown the abundance of titanium 

In soils and clays. He gives about eighty determinations.
THE CHEMICAL ELEMENTS. 21

rences 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.

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, the heaviest member of the argon group. 

Found in minute traces in the atmosphere.

Yttrium and ytterbium. Two rare-earth metals, which, with lutecium,1 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, but not 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, frankluiite; 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.

BELATIVE 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

1 The old ytterbium, the ytterbium of the former edition of this work, has been proved to be complex 

by G. Urbaln 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 aldebaranlum 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 THE DATA OF GEOCHEMISTRY.

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 6 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 l 

cubic miles, 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 expression 

for the composition of the known matter of our globe:

Composition of known matter of the earth.

Ocean. .......:................

Solid crust.....................

.................per cent..

....................do....

....................do....

2.5

0.03

7 ftQ

92.89

100. 00

2.7

0.03

6

KO

93.39

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 

be applied when needed.2 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

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

cubic miles. K. Karstens, more recently (Eine neue Berechnung der mittleren Tiefen der Oceane, Inaug. 

Diss., Kiel, 1894), put it at 1,285,935,211 cubic kilometers, or 307,496,000 cubic miles. Karstens gives a good 

summary of previous estimates, which vary widely. To change the figure given above would be a straining after unattainable precision.

2 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.
THE CHEMICAL ELEMENTS. 23

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 entire 

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.1 The 

maximum salinity observed by him amounted to 37.37 grams of salts 

in 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.......... .................

MgCl2 ................ ..........

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

CaS04 ... ....!.. .................

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

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

CaC08 ..........................

77.76

10.88

4.74

3.60

2.46

22

.34

100. 00

0.....

H.....

01.....

Na .

Mg....

Ca....

K.....

S.....

Br....

C.....

Composition of ocean.

. 85.79

. 10.67

. 2.07

1 14

14

. .05

. .04

no

. .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 

of the United States, excluding Alaska, 1.6 miles deep.2 . 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

> In vol. 1, Physics and chemistry.

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

the ocean would cover the entire globe 112 feet deep.
24 THE DATA OF GEOCHEMISTRY.

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. 1 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. 

The following averages are now available for comparison:

! A. My original average of 880 analyses, of which 207 were made in the laboratory 

of the United States Geological Survey and 673 were collected from other sources. 

Many of these analyses were incomplete.

B. The average of 680 analyses from the records of the Survey laboratories, plus 

some hundreds of determinations of silica, lime, and alkalies. The Survey data up 

to January 1, 1897.

C. The average of 830 analyses from the Survey records, plus some partial determinations. The Survey data up to January 1,1900.

D. An average of all the analyses, partial or complete, made up to January 1,1908, 

in the laboratories of the Survey.2

E. An average, computed by A. Harker,3 of 536 analyses of igneous rocks from 

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

to phosphorus and titanium.

F. An average of 1,811 analyses, from Washington's tables. 4 Calculated by H. S. 

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

Now, omitting minor constituents, which rarely appear except in 

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

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

z See Bull. U.,S. Geol. Survey No. 419,1910, p. 4, for details.

a 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. 106. In this average and in Barker's there are figures 

jor manganese, which I leave temporarily out of account. On the average composition of Minnesota rocks 

see F. F. Grout, Science, vol. 32,1910, p. 312.
THE CHEMICAL ELEMENTS. 25

although they are not absolutely comparable. The comparison 

assumes the following form:

Average composition of igneous rocks.

BiO».......................

Ala08 ... ...................

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

FeO........................

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

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

Na,,0...................... KaO...:.. ..................

HaOatl000 ................

H20 above 100°.. ...........

TiO... .....................

p o

Clarke.

A

58.59 

15.04 

3.94 

3.48 

4.49 

5.29 

3.20 

2.90

| 1.96

.55 

.22

99.66

B

59.77 

15.38 

2.65 

3.44 

4.40 

4.81 

3.61 

2.83

1.51

.53 

.21

99.14

c

59.71 

15.41 

2.63 

3.52 

4.36 

4.90 

3.55 

2.80

1.52

.60 

.22

99.22

D

60.97 

15.29 

2.63 

3.40 

3.96 

4.89 

3.47 

3.00 

.47 

1.48

.74

.26

100. 56

Harker.

E

58.98 

15.41 

4.78 

2.70 

3.71 

4.83 

3.18 

2.77

} 2.17

.52

.21

99.26

Washington.

F

58.239 

15. 796 

3.334 

3.874 

3.843 

5.221 

3.912 

3.161 

.363 

1.428 

1.039 

.373

100. 583

Although these six 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 omitted; in two it 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 rocks, reduced to uniformity.

&\QZ ....... ..................

Al O

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

FeO..........................

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

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

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

K26.. ........................

TiOa .. .......................

P O

A

59.97

15.39

4.03

3.56

4.60

5.41

3.28

2.97

.56

.23

100. 00

B

61.22

15.75

2.71

3.53

4.51

4.93

3.69

2.90

.54

.22

100. 00

C

61.12

15.77

2.69

3.60

4.46

5.02

3.63

2.87

.61

.23

100. 00

D

61.82

15.51

2.67

3.45

4.02

4.96

3.51

3.04

.75

.27

100. 00

E

60.76

15.87

4.92

2.78

3.82

4.97

3.28

2.85

.53

.22

100. 00

F

58.96

15.99

3.37

3.93

3.89

5.28

3.96

3.20

1.05

.37

100. 00

Of the averages, only D and F need be considered any further, 

for they include the largest masses of trustworthy data. A was only 

a preliminary computation, B and C are included under D; Barker's 

average contains too many incomplete analyses. D and F, however,
26 THE DATA OF GEOCHEMISTRY.

are not strictly equivalent. 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, and alkalies are generally all that is needed for petrographic 

purposes. The femic rocks are mineralogically more complex, and 

for them full analyses are necessary. The partial analyses, therefore, 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. This conclusion is in line with the criticisms of F. P. 

Mennell,1 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 may possibly be the most 

abundant, but the average composition is likely to be nearer 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 of the data given in my lormer papers see 

L. De Launay, Revue gfin. sci., Apr. 30,1904; and C. Ochsenius, Zeitschr. prakt. Geologie, May, 1898. Compare also R. A. Daly (Bull. U. S. Geol. Survey No. 209,1903, p. 110), who argues that the universal or fundamental magma is approximately basaltic. 

2 F. Loewinson-Lessing (Geol. Mag., 1911, p. 248) argues in favor of two fundamental magmas, the granitoid and gabbroid. These are thought to be present in about equal proportions in the iithosphere, and their 

average composition is close to that found by Clarke and Washington. On the mean atomic weight of the 

earth's crust see L. De Launay, Compt. Rend., vol. 150,1910, p. 1270.

> In this table all analyses of igneous rocks made in the laboratory of the Survey down to Nov, 1,1910, 

have been utilized.
THE CHEMICAL ELEMENTS. 

Average composition of igneous rocks in detail.

27

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

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

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

FeO................

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

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

Na20................

K26... ....... ......

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

H?0+ .............

Ti02 --. ............

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

C02 ........ ........

p o

S................-:.

n

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

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

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

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

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

O203 ...............

Vo08 ......... ?x^ Li20...... .........

Number of 

determinations.

1,584 

1,075 

1,124 

1,122 

1,210 

1,437 

1,496 

1,488 

781 

845 

1,025 

298 

628 

1,025 

748

o^fl zoo

96 

728 

611 

1,038 

284 

267 

87 

577

Average.

60.97 

15.23 

2.63 

3.48 

3.92 

4.87 

3.46 

3.04 

.48 

1.50 

.75 

.03 

.49 

.26 

.11 

.06 

.10 

.11 

.04 

.10 

.03 

.05 

.02 

.01

101. 74

Reduced to 

100 per cent.

59.93 

14.97 

2.58 

3.42 

3.85 

4.78 

3.40 

2.99 

.47 

1.47 

.74 

.03 

.48 

.26 

.11 

.06 

.10 

.11 

.04 

.10 

.03 

.05 

.02 

.01

100. 00

In elementary form.

0................

Si................

Al....... ........

Fe....... ........

Mg..... ..........

Ca.... ...........

Na.. .............

K.......... ......

H................

Ti...............

Zr...............

C...... ..........

P................ s.\.... ..........

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

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

Ba....... ........

Sr...............

Mn. .............

Ni..... ..........

Cr. ..............

V................

Li...............

47.05 

28.26 

7.98 

4.47 

2.34 

3.43 

2.54 

2.50 

.16 

.45 

.025 

.13 

.11 

.11 

.06 

.10 

.097 

.033 

.077 

.023 

.033 

.018 

.004

100. 000

In this computation the figures for C, Zr, Cl, F, Ni, Cr, and V are 

only very rough approximations. They are all, except possibly F, 

a little too high. They show, however, that these elements exist 

in igneous rocks in determinable quantities. The 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. It is probable that no one of them, 

except possibly copper, would reach 0.01 per cent. The elements 

not mentioned 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

1 Zeitschr. prakt. Geologic, 1898, pp. 225,314,377,413; 1899, pp. 10,274.

8 Science, January 5,1906; Econ. Geology, vol. 1,1905, p. 207. See also a curioiis paper by W. Ackroyd, 

In Chem. News, vol. 86,1902, p. 187. W. N. Hartley and H. Ramage (Jour. Chem. Soc., vol. 71,1897, p. 

533), have shown that some of the rarest elements, such as gallium and indium, are widely diffused in rocks 

and minerals. W. Vernadsky (Chem. Zent., 1910, vol. 2, p. 1775) has also found that indium, thallium, 

gallium, rubidium, and caesium are widely distributed in spectroscopic traces.
28 THE DATA OF GEOCHEMISTRY.

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 rocks.

A. Composite analysis of 78 shales; or, more strictly, the average of two smaller composites, properly 

weighted.

B. Composite analysis of 253 sandstones. 

C. Composite analysis of 345 limestones.

SiO...... ........................................

Ai n

FeA...... ......................................

FeO

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

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

Na20.. ..........................................

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

H20 at 110° ......................................

HoO above 110°... ................................

TiOa ...... .......................................

COj......... .....................................

P n

s. ................................................

S03 ..................... "........................

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

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

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

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

Li20. ............................................

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 

none 

trace 

trace 

.81

100. 46

B

78.66 

4.78 

1.08 

.30 

1.17 

5.52 

.45 

1.32 

.31 

« 1.33 

.25 

5.04 

.08

.07 

trace 

.05 

none 

trace 

trace

100. 41

C

5.19

.81

} .«

7.90 

42.61 

.05 

.33 

.21 

a. 56 

.06 

41.58 

.04 

.09 

.05 

.02 

none 

none 

.05 

trace

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 

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 comi These mixtures were prepared by G. W. Stose, under the direction of O. K. Gilbert. The analyses 

were made by H. N. Stokes in the laboratory of the United States Geological Survey. See Bull. U. S 

Geol. Survey No. 228,1904, p. 20.
THE CHEMICAL ELEMENTS. 29

position 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 of 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 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 2.54; 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 

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 0.90. This is 35 per cent of the

, l For an elaborate attempt in this direction, see C. R. Van Hise, A treatise on metamorphism: Mon. 

U. S. Geol. Survey, vol. 47,1904, pp. 947-1002.
30 THE DATA OF GEOCHEMISTRY.

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 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 the lithosphere 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 

mean elevation of all the continents is 2,411 feet. Hence, if all of 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:

i Text-book of geology, 4th ed., vol. 1,1903, p. 49.
THE CHEMICAL ELEMENTS. 31

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.

Feldspars. . ................................................

Clay b..... ............... .................................

Limonite. ..................................................

Other minerals. . ...........................................

Shale.

v 22.3

30.0

25.0

5.6

5.7

11.4

100.0

Sandstone.

66.8

11.5

6.6

1.8

11.1

2.2

 100.0

a Tho total percentage of free silica.

6 Probably serlcite 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, 4.79 

per cent of lime. This would form 8.55 per cent of calcium carbonate, or 11.2 per cent of an average limestone. But at least half of 

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 subjoined table. The analyses of the sedimentary rocks are 

recalculated to 100 per cent.

1 C. R. Van Hise (A treatise on metamorphism: Mon. U. S. Geol. Survey, vol. 47,1904, p. 940) divides 

the sedimentary rocks into 65 per 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 sedijijentaries into £0 per cent shales, 11 per cent sandstones, and 9 per cent limestones.
32 THE DATA OF GEOCHEMISTRY. 

Average composition of the lithosphere.

SiOa .........................

A\203 .. ....................

FeA...... ................

FeO............... .........

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

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

NajO....... .................

Ka0. 4 ... ...................

H20...... ..................

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

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

coa ...... ..................

P o

s^v.::::::::::::::::::::::

S08 .......... ............... ci..... .....................

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

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

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

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

NiO.................:. ......

Cr203 .......................

Va08 ... .....................

Li20. ......................

c... .......................

Igneous 

(95 per cent).

59. 93

14. 97

2.58

3.42

3.85

4.78

3.40

2.99

1.94

.74

.03

.48

.26

.11

.06

.10

.11

.04

.10

.03

.05

.02

.01

100. 00

Shale 

(4 per cent).

58.10

15.40

4.02

2.45

2.44

3.11

1.30

3.24

5.00

.65

2.63

.17

.64

.05

.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

41.54

.04

.09

.05

.02

.05

100. 00

Weighted 

average.

59.85

14.87

2.63

3.35

3.77

4.81

3.29

3.02

2.05

.73

.03

.70

.25

.10

.02

.06

.10

.10

.04

.09

.03

.05

.02

.01

.03

100. 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 

assumptions made as to the relative proportions of the sedimentaries. 

If the work were ideally exact, the last column of figures should differ from the first symmetrically, being higher in water and carbon 

dioxide and lower in all other constituents. Lime and potash, however, show small gains, which are abnormal and indicative to some 

extent of the errors above mentioned. It is possible that excessive 

weight has been assigned to the limestones, but on that theme it is 

hardly worth while to speculate. 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
THE CHEMICAL ELEMENTS. 33

been nj/ade, based upon the fact that all rocks are more or less porous. 1 

Tan tiise, however, has shown 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 

metres 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. In either 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 composition of the lithosphere, the hydrosphere and the atmosphere, 

then, is as follows:

Average composition of known terrestrial matter.

O W(TPT1

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

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

Bromine. ..................................

Lithosphere, 

93 per cent.

47. 17

28.00

7.84

4.44

3.42

2.27

2.43

2.49

.23

.44

.19

.06

Hydrosphere, 

7 per cent.

85.79

.05

.14

1.14

.04

10.67

.002

. 2.07

.008

Average, Including 

atmosphere.

49.85

26.03

7.28

4.12

3.18

2.11

2.33

2.33

.97

.41

.19

.20

i See A. Delesse, Bull. Soc. g6ol. France, vol. 29,1861, p. 64; J. D. Dana, Manual of geology, 4th ed., 1895, 

p. 209; W. B. Greenlee, Am. Geologist, vol. 18, 1896, p. 33; 0. Keller, Annales des mines, 9th ser., vol. 

12,1897, p. 32; C. S. Slichter, Water-Supply Paper U. S. Geol. Survey No. 67,1902, p. 14; T. C. Chamberlin and R. D. Salisbury, Geology, vol. 1,1904, p. 209; C. R. Van Hise, A treatise on metamorpnism: 

Mon. U. S. Geol. Survey, vol. 47, 1904, p. 129; M. L. Fuller, Water-Supply Paper U. S. Geol. Survey 

No. 160, 1906, p. 59.

a See A. D. Hall and N. J. H. Miller (Jour. Agr. Scl., vol. 2, p.'343), on nitrogen in unweathered sedimentary rocks. From 0.04 to 0.107 per cent was found. H. Erdmann (Ber. Deutsch. chem. Gesell., vol. 29, 

1896, p. 1710) found traces of nitrogen in several rare minerals from pegmatite. In a later paper, in Arbeiten 

auf den Gebieten der Gross-Gasindustrle, 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.

101381° Bull. 491 11 3
34 THE DATA OF GEOCHEMISTRY. ; 

Average composition of known terrestrial matter Continued. \

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

Barium. ...................................

Manganese. ................................

Strontium. ...............................

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

.

Lithosphere, 

93 per cent.

0.11

.11

.09

.08

.03

.10

.50

100. 00

Hydrosphere, 

7 per cent.

0.09

100. 00

Average, including 

atmosphere.

0.10

.10

.09

.08

.03

.03

.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 below atomic weight 56, and above 

that, in the analyses given on page 27, 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 we can go, but no farther. Of the actual proportions we know nothing.

THE PERIODIC CLASSIFICATION.

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:
Periodic classification of the elements. 1

Series.

1......

2......

3......

4......

5......

7......

10

11

19

Group 0.

He-4

Ne=20

A=39. 9

TTr R9 Q

Xe-130. 2

Group 1.

H=l

Li=7

Na=23

K=39. 1

Cu-63. 6

Eb=85. 5

Ag=107. 9

ria TOO Q

An 1Q7 9

Group 2.

Gl=9. 1

Mg=24. 4

Ca=40. 1

Zn=65. 4

O*. Q^ C

Cd=112. 4

Ba-137. 4

Hg-200. 6

"Do QO« A

Group 3.

B=ll

Al=27. 1

Sc-44. 1

Ga=70

Y en

In=115

La-138. 9

Tl-204

Group 4.

-

0=12

Si=28. 3

Ti=48. 1

Ge=72. 5

v*. on £

Sn=119

Ce-140. 25

Pb-206. 9

rpu OOO e;

Grou

N=14

V=51

A

Cb-93

Sb=

T'n 1 Q

T>

1 In this table the atomic weights are rounded off from the more 
36 THE 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, are 

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 Mendele'ef 

announced the law, he ventured to make specific predictions, and his 

prophesies 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, the youngest member of the elementary series, falls 

into its proper place in line with its near relative, barium.

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 

for neighbors rather than for substances that are more remote. For

1 See especially F. P. Venable, Development of the periodic law, Easton, Pennsylvania, 1896. The larger 

manuals of chemistry all discuss the law somewhat fully. T. Carnelley (Ber. Deutsch. chem. Gesell., 

vol. 17,1884:, p. 2287) has especially studied the bearings of the periodic law on the occurrence of the elements 

In rjature.
THE CHEMICAL ELEMENTS. ' 37

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 caesium 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 are 

comparatively few.

So much for the chemical side of the question. On the geological 

side other considerations must be taken into account, and it is easily 

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
38 THE DATA OF GEOCHEMISTRY.

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 1 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 sqluble. 

Solubilities of this order are yet to be experimentally studied. 5

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 farther. 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 

terrestrial nickel-iron of Ovifak 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

i Zeitsch. 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.
THE CHEMICAL ELEMENTS. 39

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.

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

A1203 - .....................................................

Fe..........................................................

FeO......................................... :..............

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

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

N%2Q..... ...................................................

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

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

Chromite ...................................................

Ni, Co. ................................:....................

S........................... '................................

P...........................................................

Found.

38.98

2.75

11.61

16.54

1.77

23.03

.95

i33

.56

.84

1.32

1.85

.11

100. 64

Kecalculated.

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. 69,1910, 

p. 52.

2 For a critical discussion of hypotheses relative to the nature and temperature of the centrosphere see 

H. Thiene, 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. 

THE ATMOSPHERE. 

COMPOSITION OF THE ATMOSPlLcjflE.

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 Sir William Ramsay for the following percentage estimate of their relative quantities.

The principal constituents of the atmosphere.

("Wvrypn

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........................................................ . 0123

These gases, with argon, are absolutely inert; and as they seem to 

have little geological significance they demand no further consideration here. 2

In addition to the elements enumerated above, ordinary air contains, in varying quantities, aqueous vapor, hydrogen dioxide, ozone, 

carbon dioxide, ammonia and other compounds of nitrogen, sometimes

1 Proc. Roy. 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. 

3 Helium, as the end product of radioactive changes, may demand some attention later.

40 .
THE ATMOSPHERE. 41

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.

V. Regnaulta. . . ...

R. W. Bunsena.....

R. Angus Smith «...

Do............

W. Hempel <=........

Do...............

bin. e 

E. W. Morley /.....

Locality of samples.

Paris...............

Heidelberg. .......

Manchester. .......

Mountains of Scotland.

Para...............

Cape Horn .........

Number 

of 

analyses.

n

100

28

32

34

45

46

41

28

20

45

Minimum.

20. 913

20. 840

20.78

20. 80

20. 901

20. 877

20.86

20.72

20.90

Maximum.

20. 999

20. 970

21.02

21.18

20. 939

20. 971

21.00

20.97

20.95

Mean.

20. 960

20. 924

20. 943

20. 970

20. 922

20. 930

20.92

20.89

20. 864

20. 933

a See R. Angus Smith's excellent book, Air and rain, London, 1872. This work contains hundreds of 

other analyses.

6 Ber. Deutsch. chem. Gesell., vol. 20,1887, p. 991. 

c Idem, vol. 18,1885, p. 1800. 

d Idem, vol. 20,1887, p. 1864. 

< Compt. Rend., vol. 102,1886, p. 422. 

/ Cited by Hempel in Ber. Deutsch. chem. Gesell., vol. 20,1887, p. 1864.

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 

significant variation of all, however, has been pointed out by E. W. 

Morley. 1 As oxygen is heavier than nitrogen, it has been supposed

i Am. Jour. ScU, 3d ser., vol. 18,1879, p. 168; vol. 22,1881, p. 417. For the distribution of the different 

gases in the atmosphere according to elevation see W. J. Humphreys, Bull. Mount Weather Observatory, 

vol. 2,1900, p. 68.
42 THE DATA OF GEOCHEMISTRY.

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 

is not absolutely established. 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 ultraviolet 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. 1 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.

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

i 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 (JourChem. Soc., vol. 97,1910, p. 868) the ozone in the atmosphere amounts to less than one part in four thousand 

millions.
THE ATMOSPHERE. 43

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 * 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 olefines and acetylenes............ .2

In short, air, according to Gautier, contains by volume about 1 part 

in 5,000 of free hydrogen, although Rayleigh's 2 experiments 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 

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, 3 formaldehyde exists in the atmosphere in

1 Annales chim. phys., 7th ser., vol. 22,1901, p. 5.

2 Phil. Mag., 6th ser., vol. 3,1902, p. 416. See also a criticism by A. Leduc, Compt. Bend., vol. 135,1902, 

p. 860; and replies to Rayleigh and Leduc by Gautier, idem, vol. 135, p. 1025; vol. 136, p. 21. Also a paper 

by G. D. Liveingand 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.

»Compt. Eend., vol. 138,1904, pp. 203,1272.
44 THE DATA OF GEOCHEMISTRY.

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 1 

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 2 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,3 abnormal 

extremes being avoided.

Determinations of carbon dioxide in air.

Analyst.

J. Reiset 0 ....................

Do.........................

T. C. Van Ntiys and B. F. 

Adams.& 

A. Petermann and J. Graftiau c . . 

E. A. Letts and R. F. Blake & . . .

Locality.

Paris...................

Near Dieppe. ...........

Bloomington, Indiana . .

Gembloux, Belgium.... 

Belfast.................

Number of determinations.

 92

18

525 

46

COs (volumes 

per!0,000ofair).

3.027

2.942

2.816

2.94 

2.91

iCompt. Rend., vol. 88,1879, p. 1007.

* Am. Chem. Jour., vol. 9,1887, p. 64.

c Cited by Letts and Blake.

dSci. Proc. Roy. Dublin Soc., vol. 9, pt. 2, 1900, pp. 107-270.

1 Annales chim. phys., 5th ser., vol. 29,1883, p. 427.

2 Jour. Chem. Soc., vol. 51,1887, p. 500. A later figure gives 17.41 pounds. See N. H. J. Miller, Jour. 

Agr. Sci., vol. 1,1905, p. 292. Miller cites data from Catania, Sicily, giving 20.89 pounds. G. Gray (Rept. 

Australasian Assoc. Adv. Sci., vol. 1,1888, p. 138) found 15.2 pounds per acre per annum in 4J years' observations at Lincoln, New Zealand.

s Very elaborate data are given in R. Angus Smith's Air and rain, to which reference has already been 

made. See also the excellent paper by E. A. Letts and R. F. Blake, Sci. Proc. Roy. Dublin Soc., vol. 9, 

pt. 2,1900, 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. 45

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 4 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 

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.

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, 5 for instance, from very

'A. Krogh (Meddelelser om Greenland, vol. 26, 1904, p. 419) estimates the total COa in the atmosphere 

at 2.4X1012 tons. Van Hise (Mon. U. S. Geol. Survey, vol. 47, 1904, p. 964) and Dittmar (Challenger 

Eeport, vol. 1, pt. 2, p. 954) give figures of the same order. Chamberlin (Jour. Geology, vol. 7,1899, p. 682) 

makes a somewhat higher estimate.

2For example, E. L. Moss (Proc. Roy. Dublin Soo., 2d ser., vol. 2,1878, p. 34) found that Arctic air is 

richer in carbon dioxide than the air of England. In air from Greenland A. Krogh (Meddelelser om Greenland, vol. 26,1904, p. 409) found the proportion of carbon dioxide to vary from 2.5 up to 7 parts in 10,000. 

The proportion determined by R. Legendre (Compt. Rend., vol. 143, 1906, p. 526) in ocean air was 3.35 

in 10.000.

8Annales chim. phys., 3d ser., vol. 10,1844, p. 456.

« Loc. oit. The present consumption of coal exceeds 1,000,000,000 tons. Krogh's figures should be correspondingly modified.

6 Phil. Mag., 5th ser., vol. 14,1882, p. 387.
46 THE DATA OF GEOCHEMISTEY.

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 

one hundred 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 * 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 2 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.

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, 3 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

i Am. Jour. Sci., 3d ser., vol. 19,1880, p. 349.

»Jour. Geology, vol. 7,1899, p. 682.

a Phil. Mag., 5th ser., vol. 41,1896, p. 237. Annalen d. Physik, 4th ser., vol. 4,1901, p. 690.
THE ATMOSPHERE. 47

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 regardsvolcanoes as the chief source of supply. Just as individual volca- 

.noes vary in activity from quietude to violence, so the volcanic 

activity of the globe has varied from tune 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, 1 who has 

attempted by means of it to account for glacial periods. E. Kayser,2 

on the other hand, has attempted to prove that the views of Arrhenius are untenable, on the ground of K. J. Angstrom's 3 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. Furthermore, C. G. Abbot and F. E. Fowle 4 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. Apparently, the controversy is not yet ended.5

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.

1 Zeitschr. Gesell. Erdkunde, Berlin, vol. 37, 1902, pp. 611, 671; idem, 1906, p. 533. Neues Jahrb., 1908, 

pt. 2, p. 74.

2 Centralbl. Min., Geol. u. Pal., 1908, p. 553; 1909, p, 660. Rejoinder by Arrhenius, idem, 1909, p. 481.

8 Annalen d. Physik, 4th ser., vol. 3, 1900, p. 720; vol. 6,1901, p. 163. Angstrom himself criticizes Arrhenius.

4 Annals Astroptiys. Observ., vol. 2,1908, pp. 172,175.

8 On the geologic side of the question see Kayser, loc. clt, and Lehrbuch der allgemelnen Geologie, 

3d ed., 1909, pp. 81-83. Also E. Koken, Neues Jahrb., Fest 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.
48 THE DATA OF GEOCHEMISTRY.

RAINFALL.

Among all the constituents of the atmosphere, aqueous vapor 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 reenforce 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 

solation 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 afterwards 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. 1 More than this trace is always present in the air, 

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,2 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

-

2- ........................

02 ....... ...................

GO*. .......................

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. Petterson and K. Sonde"n 3 found nearly 

34 per cent of oxygen. In dissolved air, then, and especially in rain, 

oxygen is concentrated, and in that way its effectiveness is increased.

1 See H. Brereton Baker, Proc. Roy. Soc., vol. 45,1888, p, 1.

2 Liebig's Annalen, vol. 93,1855, p. 48. See also M. Baumert, Idem, vol. 88,1853, p. 17, for evidence of the 

same order, 

s Ber. Deutsch. chem. GeselL, vol. 22,1889, p. 1439.
THE ATMOSPHERE. 49

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 impurities from the atmosphere, 

in quantities which vary with local conditions, and redistribute them 

upon the soil. Many analyses of rain water have therefore been 

made, not only at aglicultaral experiment stations, but also for sanitary purposes, and a few of the results obtained are given below.1 

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:

Nitrogen brought to the surface of the earth by rain. 

[Pounds per aero per annum.]

Locality.

Rothamsted, England &........

Near Paris c . ...................

Caracas, Venezuela d. ..........

Gembloux, Belgium ...........

Utah *. .......................

Nitrogen.

Ammoniacsi.

2.406

2.71

1.009 

1.006 

2.63 

5.06

Nitric.

1.13

0.516

2.443 

1.886 

1.06 

0.356

Total.

3.84 

. 8.93

9.20 

3.452 

3.541 

3.69 

5.42 

3.636 

2.08

Remarks.

5 years' average. 

1888-1901. 

11 years' average.

2$ years' average. 

5 years' average. 

20 years' average. 

3 years' average. 

3 years' average. 

3 years' average. 

4£ years 'average.

an. Warington Jour. Chem. Soc., vol. 51. 1887, p. 500. 

&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 table 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. 5G, 1889, p. 299. (Abstract.) 10.01 kilos per hectare. 

<J A. Muntz and V. Marcano. Compt. Rend., vol. 108, 1889, p. 1062.

"JTX. O. ^ Ij^l Al-LOa-l-U. OLJIL «/ * VILOillflOU} UVLtl* V11GLU* KJVV>. j WAt V/lf 4-<Ji7V. &DSt. llj p. 048. lOtOl KILOS pQF ll6Ctflr6.

/J. B. Harrison and J. Williams, Jour. Am. Chem. Soc., vol. 19,1897, p. 1.

a J. B. Harrison, Rept. Dept. Sci. and Agr., British Guiana, 1909-10. For earlier figures see preceding 

reference.

AG. H. Failyerand C. M. Breese, Second Ann. Rept. Exper. Sta., Kansas Agr. Coll., 1889.

<R, W. Erwin. Fourth Ann. Rept. Utah Agr. Coll. Exper. Sta., 1893.

^Hutchinson, Tenth Ann. Rept. Mississippi Agr. and Mech. Coll. Exper. Sta., 1897. See also Eighth 

Ann. Rept.

* G. Gray, Rept. Australasian Assoc. Adv. Sci., vol. 1,1888, p. 138. The figures include some albuminoid nitrogen.

In most cases ammonia is in excess over nitric acid; 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 sig1 For the older data see R. Angus Smith, Ah- and rain, London, 1872. 

101381° Buli. 491 11 4
50 THE DATA OF GEOCHEMISTRY.

nificance 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

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,2 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 ram 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 <*. ...............

Ceylon « ......................

Calcutta e . .....................

Madras e . ......................

Odessa, Russia /................

Barbados 9. ....................

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.

In 1887.

20 years' average.

4$ years' average.

a E. Kinch. Jour. Chem. Soc., vol. 77, 1900, p. 1271. 

6 R. Warlngton, 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, 

d Q. Bellucci, Jour. Chem. Soc., abstract, vol. 56,1899, p. 299. 42.531 kilos per hectare. 

 Cited by Miller, loc. cit.

/ J. Pirovaroff, Ann. geol. mln. Russie, vol. 9,1908, p. 274. 19 kilos per hectare. 

a J. B. Harrison and J. Williams, Jour. Am. Chem. Soc., vol. 19,1897, p. 1.

A J. B. Harrison, Kept. Dept. Sci. and Agr., British Guiana, 1909-10. For earlier figures see preceding 

reference. 

f G. Gray, Rept. Australasian Assoc. Adv. Sci., vol. 1, 1888, p. 138.

i T. Schloesing (Contributions a I'fitude de la chimie agricole, 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 ol 

the earth's surface.

On nitrates in the atmosphere see A. Muntz and E. Laine1 , Compt. Rend., vol. 152, 1911, p. 167. J. 

Hirschwald (Die Pruning der natvirlichen Bausteine, Berlin, 1908, p. 5) gives many data for ammomia 

and nitrates in the ah*.

3 See T. M. Drown, in Rept. Massachusetts State Board of Health, etc., vol. 1, December, 1889. MrsEllen 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, see 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.
NaCl...............

KC1. ..............

MgCl2 ..............

CaCL. .............

............... 37. 5

.............. 8.2

.............. 2.5

.............. 1.8

THE ATMOSPHERE. 51

Furthermore, we have the older researches of Pierre, 1 whose analyses were made in 1851 at Caen, in Normandy, where each hectare of 

soil was found to receive annually, in rain, the following impurities:

Na2S04 ........................... 8.4

K2S04 ............................ 8.0

CaS04 ........................... 6.2

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

Po§epn$-,2 as long ago as 1877, attempted to show that the sodium 

chloride of inland waters and saline lakes was derived largely from 

this source. Of late years the same idea has been strongly urged 

by W. Ackroyd,3 who has gone so far as to attribute the salinity of

the Dead Sea to chlorides brought by winds from the Mediterranean. 

Furthermore, A. Muntz 4 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.

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 terrestrial, furnishes the nuclei around which drops of rain are formed, 

and so reinforces the activity of atmospheric moisture. 5

1 See R. Angus Smith, Air and ram, 1872, pp. 223-232. Pierre also cites valuable data obtained by Barral, 

Bineau, 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.

s Sitzungsb. Akad. Wien, vol. 76, Abth. 1,1877, p. 179. See also a discussion of this memoir by E. Tietze, 

Jahrb. K.-k. geol. Reichsanstalt, vol. 27, 1877, p. 341. In a recent discussion of this subject E. Dubois 

(Arch. Musfie 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.

»Geol. Mag., 4th ser., vol. 8, 1900, p. 445. Proc. Yorkshire Oeol. and Polytech. Soc., vol. 14, p. 408. 

Chem. News, January 8,1904.

4 Compt. Rend., vol. 112,1891, p. 449.

6 See J. Aitken, Proc. Roy. Soc. Edinburgh, vol. 17,1890, p. 193.. An interesting lecture by A. Ditto 

(Revue 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.
52 THE DATA OF GEOCHEMISTRY.

THE PRIMITIVE ATMOSPHERE.

Although the main purpose of this memoir 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,3 postulates a universal, exhaustless reservoir of carbon, which should be

1 For a curious speculation on the mass of the atmosphere, seeR. H. McKee, Science, vol. 23,1906, p. 271. 

He argues that the present atmosphere is as great as the earth is capable of retaining.

2 Am. Jour. Sci., 3d ser., vol. 19,1880, p. 349.

3 Science, vol. 2,1883, p. 820.
THE ATMOSPHERE. 53

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 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,t 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 

that the unoxidized, but 'oxidizable, substances in the primitive rocks 

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, and he has been 

followed of late years by T. L. Phipson,3 J. Lemberg,4 John Stevenson,5 and Lord Kelvin. 8 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 ihe primeval atmosphere 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 fact 

that no oxygen has been found in the gases extracted from rocks is

1 Compt. Rend., vol. 87,1878, p. 541.

a 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.

8 Chem. News, vol. 67,1893, p. 135. Also several notes in vols. 68, 69, and 70. For Koene's work see Phip- 

' son's papers, 1893-94. o 

* Zeitschr. Deutsch. geol. Gesell., vol. 40,1888, pp. 630-634.

« Phil. Mag.,' 5th ser., vol. 50,1900, pp. 312, 399; 6th sen, vol. 4,1902, p. 435; vol. 9,1905, p. 88; vol. 11,1906, 

p. 226. 

8 Phil. Mag., 5th ser., vol. 47,1899, pp. 85-89. 
54 THE DATA OF GEOCHEMISTRY.

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. Smyth 1 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 uncombmed 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.

i Jour. Geology, vol. 13,1905, p. 319. 3 M6m. Soc. ingto. ciVils France, October, 1903, p. 346.
THE ATMOSPHERE. 55

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 fact? 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

1 Jour. 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 nehular hypothesis (1858) and the constitution of the sun (1865). Cited from New 

York edition of 1892.

« Wied. Annalen, vol. 5,1878, p. 405.

6 Geol. Foren. Forhandl., vol. 22,1900, p. 395.

6 For a historical summary relative to the supposed gaseous interior of the earth see S. Giinther, Jahresber. Geog. Gesell. Munchen, 1890-91, Heft 14, p. 1. See also the monograph by H. Thiene, Temperatur 

und Zustand des Erdinnern, Jena, 1907.
CHAPTER III.

LAKES AND RIVERS.»

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 portion 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 have now to study the nature of the dissolved matter 

alone, or, in other words, the composition of rivers and lakes. The

1 Excluding those belonging to closed basins.

2 Scottish Geog. Mag., vol. 3, p. 65,1887.

3 Estimates by F. W. Clarke, A preliminary study of chemical denudation, Smithsonian 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 the 

total runoff. His analytical data were too few and too limited in range for a olose computation.

56
LAKES ABTD RIVERS. 57

data are abundant, but unfortunately complicated by a lack of uniformity in the methods of statement, which latter 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 twelve such compounds must be assumed, and there is no definite law by winch their 

relative proportions can be calculated. A combination, however, is 

commonly taken for granted, and eacK chemist allots the several acids 

to the several bases according to his individual judgment. The 

twelve 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 fewBut 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 forrn, or as the silicic ion Si03 ? 

Are ferric oxide and alumina present as such, or in the ions of their

1 The ionic form of statement has been used in the Survey laboratory since 1883. In Europe it has had 

strong advocacy from Prof. C. von Than, Min. pet. Mitt., vol. 11, p. 487,1890. It is now rapidly supplanting the older system. On the geochemical interpretation of water analyses see Chase Palmer, Bull. U. S. 

Geol. Survey No. 479,1911.
58 THE DATA OF GEOCHEMISTRY.

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 are 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. The 

procedure may not be rigorously exact, but the error in it is usually 

very small. If we consider an analysis as representing the compo-. 

sition 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 half 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 most intelligible.

Before proceeding farther, 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 

water from Platte River near Greeley, Colorado,1 which he himself 

states in several forms. In the first column of the subjoined table

i Bull. Colorado Agr. Exper. Sta. No. 82,1903, p. 56.
LAKES AND RIVERS. 59

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.

Per 

cent.

SiOa .............. 1.26

S04 ................ 55.28

COj............... 8.78

01................. 3.79

Na............... 12.02

K................ .41

Ca................ 13.24

Mg................ 4.69

RaO,. ............. .53

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

so3 . ..........

C0a .... ......

01............

Na20.. ........

K20..........

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

MgO.........

(PeAl)a08 ------

Mn203 .... .....

Ignition. .....

Less 0=01. . . .

Grains 

per 

imperial 

gallon.

. . . . 0. 891

.... 32.601

. . . . 4. 554

. . . . 2. 681

.... 11.463

. . . . .355

.... 13.117

. . . . 5. 530

. . . . .189

. . . . . 189

. . . . 2. 397

73. 967 

. . . . .604

73. 363

CaS04 ........

MgS04 ........

K2S04 .......

Na2S04 .......

Nad........

Na2C03 .......

NajSiO........

(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

34. 2

1.3

1, 048. 5

100.00

"Ignition" omitted. 

Salinity, 1,014 parts per 

million.

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 Si02 into the radicle Si08 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.

SPRINGS.

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 are 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.1

i 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. 16, 1908, and 

E. Bartow, Bull. Univ. Illinois, vol. 6, No. 3,1908.
60 THE DATA OF GEOCHEMISTRY.

Analyses of spring water.

A. Spring near Magnet Cove, Arkansas. Analysis by H. N. Stokes.

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.

003..........................

S04 .........................

01..........................

Ca...... .....................

Mg... ......................

Na..........................

K.... ......................

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

Al O

Fe20.........................

Salinity, parts per million .....

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

5.72

3.97

27.17

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

.49

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 ram 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
LAKES AND RIVERS. 61

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 their 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 59 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. Cache la Poudre River above the north fork.

B. Cache la Poudre Elver water from faucet in laboratory at Fort Collins.

C. Cache la Poudre River 2 miles above Greeley. 

D. Cache la Poudre River 3 miles below Greeley. 

E. Platte River below mouth of the Cache la Poudre.

Grains per imperial gallon.

co2 ............ ......................

so3 ............... ..................

01....................................

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

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

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

Na20................................

K,0..~. .............................

SiOa ...........-...................:.

(AlFe)A--. -------------------------

Mn203 ...............................

Less 0=01..........................

A

0. 6029

.1946

.1037

.5238

trace

.1257

.3750

.0855

.6053

.0113

.0018

2. 6296 

.0234

2. 6062

B

2. 3731

1. 8699

.1055

3. 0364

.0223

.8857

.6631

.1921

.6245

.0171

.0112

9. 8009 

.0238

9. 7771

C

5.920,

54. 970

2.770

18. 938

12. 190

14. 590

.451

1.035

.079

trace

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. 359

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.

003..................................

S04 .................................

01............... .....................

Ca... ................................

Sr............................. .......

Mg...................................

Na..................................

K... .................................

SiOa .................................

Ba08 .................................

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

54, 33

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

» Bull. Colorado Agr. Exper. Sta. No. 82,1903.
62 THE DATA OF GEOCHEMISTRY.

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 

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 SiO2 and the SiO3 radicle may be neglected.

Analyses of ivater from Arkansas River at two points in Colorado.

C03 . ....................................................

S04 .. ....................................................

01.......................................................

Ca................................... ......................

Mg. .....................................................

Na.. ............................................. :.......

K. .....................................................

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

R203 - ...................................................

Canon 

City.

37.55

14.62

3.77

20.24

5.13

9.57

.60

8.19

.33

100. 00 

148

Rockyford.

2.65

60.69

4.89

12.78

3.76

14.50

.28

.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:

i 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., 4th ser., vol. 16,1903, p. 169.

a Bull. Soc. gfiol. France, 2d ser., vol. 14,1857, p. 352. A later analysis by Balland is given in Jour. Chem. 

Soc., vol. 36,1879, p. 699, abstract. Still another, by F. de Marigny, is cited by Roth. In Annales des 

mines, 5th ser., vol. 11,1857, p. 667, Marigny gives analyses of two other Algerian rivers.
LAKES AND BIVERS. 63

Analyses of water from River Chttif, 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.

003...................................................

so4 .................................................... ci... ..................................................

Ca. ...................................................

Mg.. .................. I...............................

Na........... ..........................................

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

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

A

0.93

40.36

26.40

7.46

4.12

20.64

.06

.03

100. 00 

6,670

B

1.11

25.87

39.28

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 three publications,1 in which a large number of American rivers have been 

studied with remarkable exhaustiveness. For each river or lake 

many analyses were made, in such a manner as to give its average

i Water-Supply Papers No. 230, by R. B. Dole, 1909; No. 237, by Walton Van Winkle and F. M. Eaton, 

1910; No. 239, by W. D. Collins, 1910. Water-Supply Paper 274, by Herman Stabler, also contains many 

analyses of river waters.
64 THE DATA OF GEOCHEMISTRY.

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 * 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.

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:

Analyses of water from the Great Lakes and the St. Lawrence.

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. Kept. Minnesota Geol. Survey, 1882, p. 174; by W. F. Jackman, cited by A. C. 

Lane in Water-Supply Paper U. S. Geol. Survey No. 31,1899, p. 27; and by G. L. Heath, Kept. State Board 

Geol. Survey Michigan, 1903, p. 119.

B. Lake Michigan at St. Ignace. Mean of 11 samples taken (between September 20,1906, and August 

20,1907. Analyses of Lake Michigan water at Milwaukee and of Milwaukee River, by G. Bode, are published in Geology of Wisconsin, vol. 1,1883, 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, Phil. 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.

co3 . .................

S04 ... ................ ci. ...................

N03 . ................

Ca...................

Mg...................

Na....................

K... .................

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

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

Salinity, parts per million. ................

A

47.42

3.62

1.89

.86

22.42

 5.35

1 5.52

12.76

.16

100. 00 

0.60

B

49.45

6.15

2.31

.26

22.21

7.01

1 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

6.44

4.87

10. 01

100. 00 

148

i Supplied by Chase Palmer. For details see Bull. U. S. Geol. Survey No. 479,1911.
LAKES AND RIVERS. 65

The following analyses represent tributaries to the St. Lawrence: *

Analyses of water from tributaries to the St. Lawrence.

H. Pigeon River, Minnesota. Analysis by W. A. Noyes, Eleventh Ann. Bept. Minnesota Geol. Survey1882, p. 174.

I. Grand River at Grand Rapids, Michigan. Mean of 34 composites of samples taken between October 

1,1906, 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 36 composites, between September 9,1906, to 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 MonU. 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 and J.

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.

O. Lake Champlain. Average of five analyses of samples taken in the broad lake, by M. 0. Leighton, 

Water-Supply Paper U. S. Geol. 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 236, 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 former edition of this book (Bulletin 330).

OH

so4 .................. ci. ........ ...........

NO

Ca... ...... ...........

Mg....................

Na...................

K....... ............

SiOa .. ................

Fe,03 .. ............. AI r>

Salinity, parts per

H

42.00

4.69

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

.89

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

1.52

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

12.24

.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

1.59

20.03

W. 12 *

100. 00 

45

0

45.81

11.03

1.78

21.19

4 21

| 8.80

5.58

1 1.60

'

100. 00 

67

a Includes small amounts of P0< and MnsO<.

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 

Maumee, 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.

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, Tittabawassee, 

and Boardman rivers, Manistee and Muskegon lakes, cited by A. C. Lane in Water-Supply Paper U. S. 

Geol. Survey No. 31,1903.

101381° Bull. 491 U 5
66 THE DATA OF GEOCHEMISTRY.

According to estimates made by engineers of the United States 

Army, the flow of the St. Lawrence past Ogdensburg is 248,518 cubicfeet 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 subjoined analyses are 

the most useful. In all of them bicarbonates are reduced to normal 

form, and organic matter is omitted from the calculation.

Analyses of waters from Atlantic slope I.

A. Moosehead Lake, Maine.

B. Rangeley 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. Merrimac 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 236, 1909. Analyses by C. F. Chandler of water from the Hudson, and its 

tributaries, the Mohawk and the Croton, are cited in the former 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, 

p. 703,1868; and another by H. Wurtz in Am. Chemist, vol. 4, pp. 99,133. 1873.

G. Delaware River at Lambertville, 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.

CO,.. T ................

S04 ....................

01...................

NO

Ca....................

Mg............. .......

Na...................

K.... .......... .......

SiO...................

A1263 -- ---------------

Fe203 -- -- - ------

Salinity, parts per milA

26.83

14.46

13.83

14.94

1.80

12.79

4.29

9.68

1 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

o. bo

100. 00 

48.3

D

28.15

12.78

8.78

17.14

4.18

6.16

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

3.02

18.64

4.08

6.84

1.33

7.72

.11

100. 00 

112
LAKES AND KIVERS. 67

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.

Analyses of waters from Atlantic slope II.

I. Potomac River at Cumberland, Maryland. Mean composition of 30 composite samples, taken between 

September 11,1906, and September 14,1907. Analyses by Dole, Roberts, Palmer, and Collins.

J. Shenandoah River at Millville, West Virginia. Composite of 36 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, Rept. to Richmond Board of Health, 1877, cited in the former 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.

O. Neuse River at Raleigh, North Carolina. Composite of 36 samples, October 1,1906, to October 19, 

_.907. 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.

C08 ..................

S04 .......... .........

01....................

N03 ............ .......

Ca.....................

Mg...................

Na....................

K....................

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

Al O

Fe2 03 ------------------

Salinity, parts per

I

 13. 69

44.85

4.95

.70

18.56

3.56

6.11

1.08

6.35

.15

100. 00 

130

J

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

8.67

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 7Q

2.35

9.10

2.04

37.68

2.51

100. 00 

71

N

34.99

5.90

2.95

.67

12.74

4.69

6.70

1.47

28.15

1.74

100. 00 

79

0

24.93

4.90

6.34

.43

8.50

2.59

10.09

1.87

37.47

9 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
68 THE DATA OF GEOCHEMISTRY.

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.

Analyses of waters of Atlantic slope III.

P. Cape Fear River at Wilmlngton, 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. Pedee River near Pedee, 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 Macori, 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. All the analyses in this table are from Water-Supply Paper 236. Potassium 

determinations supplied by Palmer.

C03 . .................

S04 ........ ...........

01.... ................

NO

Ca...................

Mg...................

Na......... ...........

K....................

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

FeaO,.. ..............

Salinity, parts per 

million. .............

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

1 9.62

33.65

.87

100. 00 

62

s

25.15

6.33

4.22

.60

9.49

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

.91

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

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. Chattahoochee 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 see R. S. Hodges, 

Geol. 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.
LAKES AND KIVEES. 69

G. Pearl River, near Jackson, Mississippi. Mean of 32 composites, October 16,1906, to October 19,1907. 

Same analysts as under B.

All the analyses in this table are recalculated from Water-Supply Paper 236, including later alkali determinations by Palmer.

r»/~v

so.......... .........

01....................

NO.,.. ...............

Ca. ..................

Mg......:............

Na..

K....... .............

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

Fe203 - -----------'----

Salinity, parts per

million......... .....

A

22.73

8.95

4.17

.90

13.12

2.09

1 10. 44

35.77

1.83

100. 00 

67

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 

Q9

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

89O£

F

33.34

6.37

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 much less 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. Taking the Mississippi 

itself first, the useful data are as follows, arranged in order going 

southward:
70 THE DATA OF GEOCHEMISTRY.

Analyses of water from Mississippi River.a

A. Mississippi River at Brainerd, Minnesota. Analysis by C. F. Sidener, Thirteenth Ann. Rept. 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 Carrollton, Louisiana. Analysis by C. H. Stone, Science, vol. 22, p. 472, 

1905. 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.

r\r\

80t .. ...... ..........

Gl.. ..................

NO

PO

Ca....................

Mg.. ................

Na...................

K. ..................

Si02 ........ .......... AI o

FeA.......... .......

Mn304 ...... ..........

Salinity, parts per 

million.... .........

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

1 5.65

9.09

.28

100. 00 

17Q

D

43.15

12.55

2.21

1.10

18.06

8.03

| 5.52

9.03

.35

100. 00 

90^

E

33.23

21.74

3.79

1.05

17.08

6.22

1 8.15

8.54

.20

100. 00 

9fiQ

F

30.23

20. 50

4.10

.81

17.16

5.72

8.09

1.52

11.44

.43

100. 00 

909

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

.13

100. 00

^ CD lob

a 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 former 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, Noda way,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. These relate to 

the lower Mississippi near New Orleans.

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. 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 BIVEES. 71

If we accept the figures given by J. L. Greenleaf,1 who puts the 

average outflow of the river at 664,000 cubic feet per second, the 

mean salinity of 166 parts per million corresponds to a total transport of material in solution of 98,369,000 metric tons annually. This 

is equivalent to a little over 78 metric tons from each square mile 

of territory drained. It is the contribution of the entire Mississippi 

Valley to the salinity of the ocean, but it is subject to some corrections that need to be determined hereafter.

The next table gives analyses of waters tributary to the upper 

Mississippi within the States of Minnesota and Wisconsin.2

Analyses of waters tributary to upper Mississippi River.

A. Lake Minnetonka. Analysis by W. A. Noyes, Geology of Minnesota, vol. 2,1888, p. 311.

B. Millelacs Lake. Analysis by J. A. Dodge, Geology of Minnesota, vol. 4,1899, p. 38.

C. Bigstone Lake. Analysis by C. F. Sidener, Thirteenth Ann. Eept. Geol. Nat. Hist. Survey Minnesota, 1884, p. 98. Empties into Minnesota River.

D. Heron Lake. Analysis by Noyes, Eleventh Ann. Rept. Geol. Nat. Hist. Survey Minnesota, 1882, 

p. 173. Empties into Des Moines River.

E. Rock River at Luverne, Minnesota. A tributary of Sioux River. Analysis by Noyes, Geology of 

Minnesota, vol. 1,1884, p. 550.

F. Minnesota River at Shakopee, 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.

G. 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.

003...................

S04 . .................

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

N03 .. ................

Ca............. .......

Mg.. ................

Na.......... .........

K. ..................

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

FeA-- -- --- - ---

AlA--- --------------

Salinity, parts per million........... ......

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

OQ

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

4.99

09

100. 00 

480

 G

30.49

18.09

1.42

.78

16.80

6.07

UO. 46

15.50

OQ

100. 00 

90

H

31.43

18.74

2.31

.99

15.44

7.50

1 8.93

14.33

3q

100. 00 

98

1 Am. Jour. Sci., 4th ser., vol. 2,1896, p. 29. Greenleaf gives detailed data for the important tributaries 

of the Mississippi. The area drained by the river is put at 1,259,000 square miles.

2 For analyses of several other Minnesota waters, see Water-Supply Paper U. S. Geol. Survey No. 193, 

1907,p. 133.
72 THE DATA OF GEOCHEMISTRY.

The following table gives analyses of waters tributary to the Mississippi in Illinois and Iowa:

Analyses of tributaries in Illinois and Iowa.

A. Bock River near Sterling, Illinois. Mean analysis of 36 composite samples, taken between August 1,

1906. and July 31,1907. W. D. Collins, analyst. Collins also gives a similar annual average for the river 

at Kockford.

B. Illinois River near Kampsville, Illinois. Mean of 36 composites, August 1, 1906, to July 31,1907. 

Collins, analyst. He 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 July31,1907. 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 6,1908, to September 16,1907. 

Same analysts as under D.

F. Des Moines 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 Paper 239; the 

others are from Dole, Water-Supply Paper 236.

Collins also gives annual averages for the composition of the waters of Kankakee, Fox, Vermilion, 

Sangamon, Muddy, Embarrass, Little Wabash and Cache rivers. In all, 19 rivers were studied, including 

the Mississippi.

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

S04 ................ ...........

01........... .................

N03 . ........................

Ca. ..........................

Mg........ ...................

Na..........................

K.. ..........................

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

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

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

| 5.59

7.24

.17

100. 00 

312

In the following table I give analyses of waters which reach the 

Mississippi from the eastward by way of the Ohio. 1 For the Ohio 

itself I have found no satisfactory data.

Analyses of waters tributary to Ohio River.

A. Allegheny River at Kittanning, Pennsylvania. Mean analysis of 36 composite samples taken between 

September 13,1906, and September 10,1907. R. B. Dole, M. G. Roberts, and C. Palmer, analysts.

B. Monongahela 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 Youghiogheny water.

C. Muskingum 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 16, 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 8,1906, 

to September 12,1907. Barr, Spaulding, and Van Winkle, analysts.

i An analysis of Monongahela water by C. D. Howard and one of water from the Cumberland by N. T. 

Lupton are given in the former edition of this book (Bulletin 330).
LAKES AND EIVEBS. 73

0. Wabash River at Vincennes, Indiana. Mean of 31 composites, September 9,1906, to September 16, 

1907. 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. 

I. 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 

24,1908. Van Winkle, Dole, Palmer, and Collins, analysts. Another average is given for the water at 

Knoxville, Tennessee.

All the 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.

C08 ............... ...................

S04 ........ ... . ..............

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

NO

r,n

Mg...................................

Na.................................... K....................:...............

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

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

C03 . .................................

S04 .. ... ........

01....................................

N03 .................................

Ca...................................

Mg...................................

Na....................................

K....................................

SiO,. ................................

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

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

1.97

21.51

8.11

2.75

.77

5.29

.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

For the largest tributary of the Mississippi the Missouri several 

analyses are available. They are given in the following table, together 

with analyses of its affluents. 1

1 Two analyses of water from the Missouri, not used here, are given in the former edition of this book. 

Another analysis by F. W. Traphagen is cited in E. W. Hilgard's Soils, p. 23, but the point of collection 

is not named.
74 THE DATA OF GEOCHEMISTRY.

Analyses of water from Missouri River and tributaries.

 A. Missouri River near Florence, Nebraska. Mean analysis of 36 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 W inkle, 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. 59, 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 Laratnie is printed in Fifth Rept. 

Bur. Soils, U. S. Dept. Agr., 1903.

H. Yellowstone Lake. Analysis by J. E. Whitfield, Bull. U. S. Geol. Survey No. 47,1888. This bulletin 

also gives analyses of Firehole and Gardiner rivers.

Analyses A to E are recalculated from Dole's Water-Supply Paper 236, with potassium determinations 

communicated by Palmer.

CO,. ................

S04 ..................

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

NO,.... ..............

Ca.. ..................

Mg.. ....... .........

Na...................

K. ..................

NF

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

AI r>

Fe-A.. ...............

Salinity, parts per 

million. ............

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

8.97

.24

100. 00 

426

C

25.63

30. 44

3.52

.85

15.22

4.68

9.07

1.90

8.49

.20

100. 00 

346

D

24.13

32. 77

3.15

.53

15.05

4.37

UO. 68

8.98

.34

100. 00 

426

E

29.43

22.18

2.18

.33

15.80

3.67

8.06

2.42

15.80

.13

100. 00 

302

F

27.35

11.16

3.11

13. 75.

2.45

7.34

.85

31.73

2,. Zb

100. 00 

212

G

19.59

37.48

6.32

15.07

5.10

8.82

1.96

4.54

| 1.12

100. 00 

49Q

H

20.93

7.12

7.96

7.29

.25

13.22

3.99

.34

35.51

3.39

100.00

In all but three of these waters sulphates predominate over carbonates, and calcium is less conspicuous than in the analyses 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. The Kansas or Kaw River, with its 

chief affluents, has been studied by E. H. S. Bailey and E. C. Franklin,1 

whose data, reduced as usual, are given below. It should be observed, 

however, that the analyses are not complete; the sodium was calculated and the potassium not considered at all. The localities mentioned are all in the State of Kansas, and the arrangement of the 

streams is from the west, eastward.

» Kansas Univ. Quart., vol. 3,1894, p. 91.
LAKES AND RIVERS. 75

Analyses of water from Kansas River and tributaries.

A. Smoky Hill>River below Salina.

B. Saline River above New Cambria.

C. Solomon River above Solomon.

D. Republican River above Junction City.

E. Blue River.

F. Delaware River at Perryville (not to be confused with the eastern river of the same name). Analysis 

by J. E. Curry.

G. Wakarusa River south of Lawrence. Analysis by J. E. Curry.

H. Kansas River, average of two analyses, one sample taken above Topeka, the other above Lawrence. 

The two are fairly concordant.

CO,.... ...............

QfY

ci.....................

Ca.......... ..........

Mg... .......... .......

Na..... ..............

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

(AlFe)208 .. ...........

Salinity, parts per 

million .............

A

16.07

24. 52

22.41

13.86

2.62

17 81

2.03

.68

100. 00 

1,017

B

13.70

16. 94

34.61

5.62

1.88

flfi 07

.98

.20

100. 00 

2,323

C

14.12

23. 36

24.55

11.58

2.16

 3015

3.63

.45

100. 00 

1,105

D

31. 41

10 71

10.02

15.62

3.19

1306

11.61

1.38

100. 00 

554

E

35.41

16. 17

6.48

18.90

4.91

7.89

O CQ

1.65

100. 00 

436

F

44.54

n

OQ

6.03

23.14

5.49

4.76

Q QQ

1.37

100. 00 

396

G

42.66

7 ^Q

6.69

23.27

3.12

12. 81

9 77

1.09

100. 00 

499

H

23.83

18 1 ^

18.80

14.76

3.51

15.45

4 81

.67

100. 00 

766

The four 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 

the Blue River carbonates begin to predominate; and in the easternmost rivers of the group, the Delaware and the Wakarusa, there is a 

close approximation in chemical character to the streams of the Atlantic slope. The Kansas River itself represents a blending of air the 

waters which flow into it.

Two analyses of water from the Arkansas River, by Headden, 

have already been cited, but it seems well to reproduce them here, 

with others of the same important stream and also of the Red River, 

as follows: 1

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. For recent analyses of Kansas waters see H. N. Parker, 

Water-Supply Paper 273,1911. They should supplant the analyses cited above.
76 THE DATA OF GEOCHEMISTRY.

Analyses of water from Arkansas River and tributaries.

A. Arkansas River at Canon City, Colorado.

B. Arkansas River at Rockyford, Colorado. Analyses A and B by W. P. Headden, Bull. Colorado Agr. 

Exper. Sta. No. 82,1903.

C. Arkansas River at Little Rock, Arkansas. High water, December 20,1888.

D. Arkansas River at Little Rock. Low water, August 22,1888. Analyses C and D by R. N. Brackett, 

Ann. Rept. Arkansas Geol. Survey, 1891, vol. 2, pp. 159,160. Recalculated here to standard form. According to J. C. Branner (idem, p. 164), the river carries in solution past Little Rock 6,828,350 tons annually.

E. Arkansas River at Little Rock. Mean analysis of 22 composite samples, taken between Novemcer 1, 1906, and October 24, 1907. Barr, Spaulding, Van Winkle, Dole, Palmer, and Collins, analysts. 

Recalculated from Water-Supply Paper 236.

F. Neosho River at Chanute, Kansas. A tributary of the Arkansas. Analysis by C. F. Gustavsen, 

Kansas Univ. Sci. Bull., vol. 2,1903, p. 243. Reduced from bicarbonate form.

G. Red River near Shreveport, Louisiana. Average of 34 composites March 19,1906, to March 19,1908, 

Dole, Palmer, Collins, and Evans, analysts. Recalculated from Water-Supply Paper 236, with later 

alkali determinations by Palmer.

on

so4 ......... .......... ci...... ..............

NO

Ca......... ............

Mg...................

Na

K.......... :.....-...

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

AljjOj..................

Fe208 - - ---

Salinity, parts per

A

37,55

14.62

3.77

20.24

5.13

9.57

.60

8.19

} .33

100. 00 

148

B

2.65

60.69

4.89

12.78

3.76

14.50

.28

.45

100. 00 

2,134

C

20.92

8.15

22.21

7.20

1.75

19.83

3.68

12.00

.61

3.65

100. 00 

109

D

10.80

12.61

38.55

7.60

1.67

25.92

.74

1.81

.24

.06

100. 00 

794

E

11.89

15.19

33.17

.33

8.99

2.13

1 23. 53 '

4.57

.20

100. 00 

630

F

21.74

16.08

2.78

15.76

.10

7.91

26.02

} 9.61

100. 00 

306

G

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 subjoined analyses represent this 

group. 1

1 An analysis of Rio Grande water by 0. Loew is given in Rept. U. S. Geog. Surveys W. 100th Mer., 

vol. 3,1875, p. 576. In the annual report of the same Survey for 1876 Loew gives an analysis of water from 

Virgin River, a tributary of the Colorado. For two analyses of the Pecos see B. B. 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.
LAKES AND EIVEES. 77

Analyses of water from southwestern rivers.

A. Brazos River at Waco, Texas. Mean analysis of 30 composite samples taken between December 

14, 1906, and November 19, 1907. Barr, Spaulding, Van Winkle, Dole, Palmer, and Collins, analysts. 

Recalculated from Water-Supply Paper 236, with later alkali determinations by Palmer.

B. Colorado River of Texas, at Austin. Mean of 36 composites, August 1,1905, to July 27,1906. W. H. 

Heileman, analyst, Water-Supply Paper 236.

C. Rio Grande at Laredo, Texas. Mean of 37 composites, August 1,1905, to August 2,1906. Heileman, 

analyst, loc. cit.

D. Rio Grande 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 Fe River, and Rio Bonito.

E. Pecos River, New Mexico. Average of six samples analyzed by Goss, loc. cit.

F. Colorado River at Yuma, Arizona. Average of seven composite samples, covering collections made 

between January 10,1900, and January 24,1901. Analyzed by R. H. Forbes and W. W. Skinner, Bull. 

Univ. Arizona Agric. Exper. Sta. No. 44,1902. The average composition of the water during a year.

G. Gila River at head of Florence canal, below The Buttes, Arizona. Average of four analyses, by 

Forbes and Skinner, representing twenty-one weekly composites. Samples taken between November 

28,1899, and November 5,1900.

H. Salt River at Mesa, Arizona. Average of six analyses covering forty 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 

Si08 . This is reduced to SiOa in the table.

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

S04 ..................

01.....................

NO

Ca....................

Mg... .................

Na.... ...............

K.. ...................

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

AlA...,. ............

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

Salinity, parts per

A

7.09

25.49

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

1 .92

100. 00 

321

C

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

I 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

H

Q fil

8.29

41.56

7.15

2.69

26.38

1.38

2.94

100. 00 

1 9<U

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 toils of 

salts, or about 59.6 metric tons from each square mile of its basin.

NORTHWESTERN RIVERS.

The following table contains analyses of waters tributary to the 

Pacific Ocean north of California.
78 THE DATA OF GEOCHEMISTRY.

Analyses of northwestern waters.

A. Yukon River at Eagle, Alaska. Analysis by G. Steiger. Reported by F. W. Clarke, Jour. Am. 

Chem. Soc., vol. 27,1905, p. 111.

B. Cedar River, Washington. Analysis by H. G. Knight, Rept. Washington Geol. Survey, vol. 1,1901, 

p. 285.

C. Snake River, Blackfoot area, Idaho.

D. Powder River near Baker City, Oregon. Analyses C and D made under the direction of F. K. Cameron, Fifth Rept. Bur. Soils, U. S. Dept. Agr., 1903. An analysis of Powder River at a different point is 

also given in this report.

E. Columbia River at Mayger, Oregon. Analysis by B. Pilkington. Reported by C. E. Bradley, Jour, 

Ind. Eng. Chem., vol. 2,1910, p. 294.

F. Willamette River at Corvallis, Oregon. Pilkington, analyst, loc. cit. Recalculated with the aid of 

a correction on p. 496 of the same journal.

G. Lost River, Klamath County, Oregon. Analysis by A. L. Knisely, Ann. Rept. Irr. and Drainage 

Investigations, U. S. Dept. Agr., 1904, p. 264.

PA

S04 .. .................

01....................

PO

Ca.....................

Mg. ..................

Na.......... ..........

K. ...................

NTT

SiOa ...................

k\£)3 ....... ...........

Fe203 ... ............... * o

Salinity, parts per million ................

A

46.16

10.75

.41

22.21

4.71

6.14

7.78

1.84

100. 00 

98

B

32.65

11.85

4.86

26.68

1 27

.81

5.81

} 16. 07

100. 00 

31

C

26.31

13.36

17.01

16.20

3.64

15.38

8.10

100. 00

247

D

3.17

64.28

.34

1.69

1.49

28.09

.94

100. 00 

1,481

E

31.66

10.62

10.62

.15

16. 80 '

4.83

7.72

7.91

.81

4.63

4.25

100. 00 

51.8

F

24.07

10.29

9.63

.17

8.31

2.19

10.72

6.13

1.14

26.48

.87

100. 00

45.7

G

52.64

3.37

1.46

14.12

12.06

2.78

.78

10. 42

| 2.37

100. 00 

220

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 edition of this 

book; * the following table is recalculated from the figures reported 

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.

___________________________i_____________

i Clear Lake, analysis by T. Price, cited in Water-Supply Paper U. S. Geol. Survey No. 45,1901. Feather 

River, by E. W. Hilgard, 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.
LAKES AND RIVERS. 79

Analyses of water from rivers of California.

A. Eussian 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+AIaO3. In recalculating, these determinations are assumed to be fair averages. Van Winkle and 

Eaton also give annual averages for Feather, Ynba, 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 3G composites, covering the year 1906. K 

and total RjOa 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 RaOa 

only determined during the first half year.

G. San Gabriel River near Rivera. Mean of 37 composites, covering the year 1908. Another average 

is given for the river at Azusa.

H. Santa Ana River above Mentone. Mean of two series, 1906 and 1908. K and RjOa determined 

during the first half of 1906. Another annual average is given for the river near Corona.

co8 ........ .......:

S04 . .................

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

NO

Ca....................

Mg....................

Na

K.....................

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

Al A

FeaOB 

Salinity, parts per milA

39,07

10.81

4.70

.77

14.61

7.62

110. 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
80 THE DATA OF GEOCHEMISTRY.

THE SASKATCHEWAN SYSTEM.

This complex river system comprises a number of important 

branches, which finally unite in the Nelson River and empty into 

Hudson Bay. The following analyses represent waters from this 

great drainage basin:

Analyses of waters from Saskatchewan system.

A. Eed River of the North at Fergus Falls, Minnesota. Analysis by W. A. Noyes, Eleventh Ann. 

Rept. Minnesota Geol. 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 D and E 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 

F and G by W. Dittmar, Rept. Progress Geol. Survey Canada, 1879-80, p. 77 C.

f\f\

so4 .............. .............

01............................

PO

N08 ..-.. ..- ...............

Ca....... ....................

Mg........ ...................

Na... ..........................

K................. ...........

Li...........................

SiOa ......... .................

(AlFe)203 --- .................

Salinity, parts per million. ....

A

32.52

25.56

.69

30.39

1.97

1.19

.60

7.08

100. 00 

202

B

41.20

15.71

4 SQ

.19

.28

17.55

8.23

5.64

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

.97

7 30

.64

100. 00 

180

F

50.36

3.08

21. 88

5.24

4.22

1.37

11.48

2.37

100. 00 

115

The following table gives analyses of the Bow River and its tributaries, the Bow being the main western branch of the Saskatchewan. 

All of 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.

1 Rept. Geol. Survey Canada, new ser., vol. 9,1878, pp. 39-45 R.
LAKES AND RIVERS. 81

Analyses of water from Bow River and tributaries.

H. Bow River at Calgary.

I. Elbow River at Calgary.

J. Highwood River at High River.

K. Fish Creek at McLeod Trail. 

L. Sheep River near Dowdney.

003.................................

S04 . .................................

01...................................

Ca..................................

Mg... .......... .......................

Na. ..................................

K.....................................

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

Fe.,0..................................

Salinity, parts per million. .............

H

48.21

14.69

.94

25.23

6.95

2.42

trace

1.56

trace

100. 00 

 128

i

44.66

18.80

.56

24.39

6.55

2.77 .42"

1.85

trace

100. 00 

217

j

47.78

13.22

.65

24.48

6.23

3.28

trace

4.36

trace

100. 00 

183

K

53.57

5.59

.51

18.82

7.57

7.14

1.34

5.46

trace

100. 00

938

L

45.55

17.13

.57

23.69

6.32

3.92

.43

2.39

trace

100. 00 

209

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 of the waters from 

east of the Missouri River, with one or two minor exceptions, are 

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 rivers; but the western tributaries of 

the Missouri, in general, teh1 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 the 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 

101381° Bull. 491 11 6
82 ' THE DATA OF GEOCHEMISTRY.

in carbonates. Eastern Kansas is fertile, and the eastern affluents 

reflect its character. It must be borne in mind, 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 sliould 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, 

may have a sulphate character quite independent of the climatic 

influences which otherwise seem to rule.

These 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 Illinois 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 commingling 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 the Argentine 

Republic, 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. 

Apart from a few scattered memoirs I have found little of value 

relating to the northern part of the continent. The following table 

gives the available data for the Amazon and its tributaries:

1 Compt. Rend., vol. 107, 1888, p. 908. See also J. Reindl, Natur. Wochenschr., vol. 20, 1905, p. 353.
LAKES AND RIVERS. 83

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 Reade in Evolution of Earth Structure.

B. The Amazon at Obidos. Mean of two analyses by F. Katzer. See Grundziigo der Geologie des 

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. TheTapajos. Analysis by Katzer, loc. cit. Katzer also gives analyses of water from Parana-mirira, 

the Maecuru, the Jtapacura-mirim, and several fresh-water lakes or lagoons.

co3 ........... ................................

so4 .......................................... ci.............................................

Ca. ...........................................

Mg..:.........................................

Na...........................................

K......... ....................................

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

(AlFe)203 - --.--- ---------- - ------ -.- -.- 

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

12.97

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

From the southern parts of South America the following waters 

have been analyzed:

Analyses of water from rivers in southern part of South America.

A. River Plata 5 miles above Buenos Ayres. Analysis by J. J. Kyle, Chem. News, vol. 38, 1878, p. 28.

B. River Plata near Buenos Ayres. 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, p. 326,1877.

G. Colorado River, Argentina. Analysis by Kyle, An. Soc. cient. Argentina, vol. 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.

co3 . .................

S04 ...................

01.... ................

N03 ........... ........

Ca...................

Mg...................

Na........... .........

K....................

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

A12 03 - ...............

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

Salinity, parts per million. ...............

A

17.45

7.69

12.59

6.18

3.31

17.34

3.09

21.32

6.62

4.41

100. 00 

91

B

11.59

17.97

18.11

6.68

3.71

1.42

24.89

i6.82

} 4.81 '

100. 00 

206

C

17.73

10.13

15.92

7.27

2.78

14.96

4.06

20.73

3.21

3.21

100.00 

98

D

24.23

3.90

.61

5.50

9.82

2.85

3.75

3.12

46.22

100. 00 

40

E

21.59

6.15

5.12

io.oi

2.97

5.92

44 "¥>

} 3.92 '

100.00 

66

F

39.10

1.23

4.43

1.95

17.82

1 Qfi

10.24

21.75

} 1.52 '

100. 00 

132

G

8.19

30.58

24.51

16.24

1.46

15.78

Q 94

100. 00 

651
84 THE DATA OF GEOCHEMISTRY.

Analyses of water from rivers in southern part of South America Continued.

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. C<5rdoba, 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 

de Atacama, vol. 3, Santiago, 1902, p. 191.

003..................

S04 ....... ............

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

N08 ............. ......

Ca. 3.. ................

Mg.. .................

Na......... ...........

K..... ...............

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

AUV ...............

FeA. ...............

S............. ........

Salinity, parts per million ................

H

39.47

5.76

6.41

16.53

3.27

9.09

4.67

8.58

1.10

5.12

100. 00 

160

I

.06

31.81

32.63

8.01

.36

26.48

.49

.16

100. 00 

9,185

J

9.94

27.75

21.51

11.29

2.87

16.12

4.41

6.11

100. 00 

1,213

K

39.13

13. 24

2.77

19.63

5.20

1.82

' 5.75

11.57

.89

100. 00

127

L

28.27

18.17

5.53

13. 20

2.53

7.19

10.20

12.33

.49

2.09

100. 00 

104

M

18.06

24.45

8.04

14.93

2.63

15.37

13.22

3.30

100. 00 

186

N

6.46

36.50

6.61

3.52

8.96

.36

35.39

1 2.20

100. 00 

731

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 is peculiar 

because of its high proportion of silica a condition which will be 

discussed later in the chapter.

LAKES AND RIVERS OF EUROPE.

Both Bischof and Roth cite numerous earl»y and often incomplete 

analyses of European river waters, but it is not necessary to reproduce 

all of them 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.
LAKES AND RIVERS. 85

Analyses of British waters.

A. Loch Baile a Ghobhainn, Lismore 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. The 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. 

376. Analyses are also given of the Thames at Battersea and Lambeth, of the New River and several springs. 

For other analyses of the 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, Jour. Chem. Soc., vol. 8,1856, p. 97, and H. M. Witt, Phil. 

Mag., 4th ser., vol. 12,1856, p. 114.

G. Lough Neagh, Ireland. Analysis by J. F. Hodges, Chem. News, vol. 30,1870, p. 103. An analysis of 

the river Bann is also given.

See also C. M. Tidy, Jour. Chem. Soc., vol. 37,1880, p. 208, forpartial analyses of the Thames, Lea, Severn, 

and Shannon. E. Hull, Geol. Mag., 1893, p. 171, cites analyses of Thirlmere, Bala Lake, and the Severn, 

which I am unable to trace to the original publications. In T. E. Thorpe's Manual of inorganic chemistry, 

vol. 1, p. 207, analyses of the Clyde and Loch Katrine are given. For analyses of the River Trent, see Jour.

Soc. Chem. Ind., vol. 30, 1911, p. 70.

rn

S04 .......... ......... ci.....................

NO....................

PO i^J4 ... ................

Ca...................

Mg.. .................

Na

K....................

SiOa ......... ..........

AlaOj...... ............

Fe2 03 ................

Salinity, parts per million ................

A

57.49

trace.

1.41

trace.

.02

37.77

.25

}

Q4

1.62

.50

100. 00 

160

B

23.35

15.70

17.08

17.22

2.98

1 13. 60

6.41

6. bo

100. 00 

31

C

23.15

16.29

14.19

16.32

3.54

1 9.17

10.62

D. 7.6

100. 00 

81

D

41.86

11.82

5.20

.84

30.10

1.95

2.26

2.25

3.26

I 4fi

> . 4o

100. 00

272

E

39.53

14.72

4.57

trace.

28.57

1.82

3.28

1.55

2.36

3. 60

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 W

6.72

100. 00 

155

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 downwards 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.

1 See W. W. Fisher, The Analyst, vol. 29, 1904, p. 29.

2 J. Thoulet (Bull. Soc. g6og., 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 also A. Delebecque and 

L. Duparc, Compt. Rend., vol. 114, 1892, p. 984; and Arch. sci. phys. nat., 3d ser., vol. 27,1892, p. 5C9; 

vol. 28,1892, p. 502.
86 THE DATA OF GEOCHEMISTRY.

Analyses of waters in western Europe.

A. The Meuse at Liege, Belgium. Computed from data given by W. Spring and E. Prost, Ann. Soc. 

geol. Belg., 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. P. Chandelon and J. W. Gunning are cited by Bischof.

B. The Seine at Bercy. Analysis by H. Sainte-Claire Deville, Annales chim. phys., 3d ser., vol. 23, 

1848, p. 42.

C. The Loire near Orleans. Analysis by Deville, loc. cit.

D. The Garonne at Toulouse. Analysis by Deville, loc. cit.

E. The Doubs at Rivotte. Analysis by Deville, loc. cit.

F. The Isere. Analysis by J. Grange, Annales chim. phys., 3d ser., vol. 24, 1848, p. 496. Grange also 

gives analyses of several small tributaries, and correlates them with then- geological surroundings.

G. The Rhone at Geneva. Analysis by Deville, loc. cit.

H. The Rhone. Average of five analyses by L. Lossier, Arch. sci. phys. nat., 2d ser., vol. 62,1878, p. 220. 

Organic matter rejected.

I. The Arve. Average of six analyses by Lossier, loc. cit.

J. Lac Leman. Analysis by R. Brandenbourg, cited by F. A. Forel in Me"m. Soc. Helvfit., 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. TheDouro. Analysis cited in Mem. Com. mapa geol. Espafia, Prov. Salamanca. Analyst not named.

co8~ ........................

S04 ... ....:................... ci...........................

N03 .........................

Ca...........................

Mg...........................

Na. ........

K....... .....................

Li...........................

SiOa .........................

AI n

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

Mn203 .......................

co3 ..... .....................

so4 ......................... ci................ ............

N03 ....... ..................

pn

Ca........ ...................

Mg............. ..............

Na ..........................

K.. ..I.......................

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

Al O

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

Salinity, parts per million .....

A

36.48

13.13

3.83

2.86

28.90

2.68

2.24

.87

.05

6.02

| 2.94

100. 00

G

27.92

23.18

.55

3.13

24.89

1.48

2.75

.88

13.08

2.14

100. 00 

182

B

39. 78

8.57

2.95

4.44

29.13

.63

2.87

.86

9.59

1Q

.99

100. 00 

254

H

36.69

26.68

.71

.31

26.42

3.66

1 3.98

1.55

100. 00 

170

C

30.92

1.72

2.16

14.31

1.34

6.93

1.64

31.59

5.29

4.10

100. 00 

134.

I

42.37

18.81

1.46

.32

29.64

3.17

1 2.53

1.70

100. 00 

192

D

33.07

5.59

1.40

18.99

.67

4.42

2.50

29. 53

2.28

1.55

100. 00 

137

J

33.87

26.66

.52

27.81

2.23

2.53

.25

5.63

} .50

100. 00 

152

E

50.41

1.53

.74

2.35

33.20

.40

1.53

.70

6.91

.92

1.31

100. 00 

230

K

59.14

trace.

.69

34.40

3.06

trace

trace

2.71

I traces '

100. 00 

144

F

34.14

24.11

4.53

25.40

3.67

f ^t. o£t

1.97

1.86

trace.

100. 00 

188

L

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
LAKES AND RIVERS. 87

have been exhaustively studied. In an elaborate thesis by F. E. 

Bourcart, 1 analyses are given 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 de 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 Molasse. Drains into the Aar.

E. LacRitom, above Airolo, Canton Ticino. Surface water.

F. Lac Ritom, lower layer of water, below 13 meters depth. This lake drains southward into Italy.

C08 ..........................

S04 ......................... ci............ ................

Ca...........................

Mg................. ........:.

Na. .........................

K............................

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

AlA+FeA"- ................

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

100. 00 

270.5

D

53.84

q qo

1.77

33.30

1.76

1.80

.93

3.03

.25

100. 00 

201.7

E

20.00

47 97

22. 12

5.47

1.22

1.64

2.28

100. 00 

122.5

F

2.29

ftQ 8Q

22.15

4.96

.09

.15

.42

.05

100. 00 

2,373

a Including traces of manganese.

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 

Illyes 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.2 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.

1 Thesis, Univ. Geneva, 1906. Les lacs alpines suisses, 4°, 130 pp. A few selected analyses appear in 

Arch. sci. phys. nat., 4th ser., vol. 15,1903, p. 467.

* See also incomplete analyses of the Starnberger, Kochel, and Walchen lakes by J. Gebbing, Jahresber. 

Geog. Gesell. Munchen. 1901-2, p. 55. Also W. Ule's monograph on the Wurmsee, published by the Vereln 

fiir Erdkunde, Leipzig, in 1901.
88 THE DATA OF GEOCHEMISTRY.

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. Hallstattersee, 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. Godefiroy, Jahresber. 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.

C08 ...................................

S04 . .................................

SI....................................

N02 ..... .............................

Ca....................................

Mg..... ........ .......................

Na...... .......... ...................

K.....................................

SiOa ....... ...........................

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

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

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

COs...................................

S04 . .................................

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

PO

Ca............ .........................

Mg....................................

Na

K........................ . .

Sio2 ..............:...................

AI n

Fea08 ..... ............................

Salinitv. t>arts rcer million. .............

A

50.83

11.62

.58

26.49

7.00

.99

.58

1.00

1 91 / ' 91

100. 00 

121

F

49.58

12.09

1.92

23.22

8.17

2.18

Q7

.92

.89

.06

100. 00 

191

B

48.46

14.78

.48

24.66

6.17

1.52

1.52

1.60

.73

.04

.04

100. 00

 227

G

50.59

6.54

.65

.05

32.65

3.41

.70

1 24

1.73

2.33

.11

100. 00 

98

c

54.69

4.73

1.5/

.07

24.09

7.98

.96

2.14

1.26

2.44

.07

100. 00 

139

H

38.43

9.43

10.94

26.37

3.88

6.50

9 77

1.31

}

37 .37

100. 00 

137.5

D

48.25

15.24

.58

26.17

6.56

1.10

.88

.44

.73

.05

100. 00 

207

I

51.68

8.99

2.44

27.54

5.21

2.82

.31

1 1.01

100. 00 

99

E

50.74

11.15

.55

26.94

5.78

1.05

1.07

1.62

1.05

.05

100. 00 

190

J

53.29

4.17

3.13

24.56

6.66

9 40

2.01

2.33

1.21

.15

100. 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 table following contains a part of them, recalculated 

to modern standards, with organic matter rejected.

i For an imperfect analysis of the Bodensee (Lake of Constance) see H. Bauer and H. Vogel, Jahresh. 

Ver. vaterl. Naturk. Wurttemberg, vol. 48,1892, p. 13. Many partial analyses of waters from Rhine tributaries are given by E. Egger, Notizbl. Ver. Erdkunde, Darmstadt, 1908, p. 105; 1909, p. 87. These two 

papers are on the hydrocbemistry of the Rhine.
LAKES AND RIVERS. 89

Analyses of water from the Rhine and its tributaries.

A. Lake of Zurich. Analyses by Moldenhauer, 1857, cited by Roth, Allgemelne und chemische Geologle, 

vol. 1, p. 456.

B. The Aar at Bern. Analysis by J. S. F. Pagenstecher, 1837, cited by Roth.

C. The Rhine at Basel. Analysis by Pagenstecher, loc. cit.

1 D. The Rhine at Strasburg. Analysis by H. Sainte-Claire Devllle, Annales chim. phys., 3d ser., vol. 23, 

1848, p. 42.

E. The Rhine near Mainz. Analysis by E. Egger, Notizbl. Ver. Erdkunde, Darmstadt, 1887, p. 9. An 

earlier analysis is in the volume for 1886, p. 21.

F. The Rhine at Cologne. Mean of seven analyses by H. Vohl, Jahresber. Chemie, 1871, p. 1323.

G. The Rhine at Arnheim. Analysis by J. W. Gunning, Jahresber. Chemie, 1854, p. 767.

H. The White Main.

I. The Red Main.

J. The united Main. Analyses H, I, and J by E. Spaeth, Inaug. Diss. Erlangen, 1889. Spaeth also 

gives analyses of water from the Rodach, Haslach, and Kronach, tributaries of the Main.

K. The Main above Offenbach. Analysis by C. Merz, Jahresber. Chemie, 1866, p. 987.

L. The Main at Frankfort. Analysis by G. Kerner. Cited by F. C. Noll, Inaug. Dlss. Tubingen, 1866, 

from a report published at Frankfort in 1801.

M. The Main above.its mouth. Analysis by E. Egger, Notizbl. Ver. Erdkunde, Darmstadt, 1886, p. 17.

N. The Nahe at Bingen. Analysis by Egger, idem, 1887, p. 5.

003....................

SO....................

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

NOwo3 ............. ......

Ca.....................

Mg............. ......

Na....................

K....................

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

AI o

Pea08 - ----

Salinity, parts per milrr>

so4 ...................

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

NO NU3 ....... ............

Ca.....................

Mg...................

Na....................

K....................

SiO....................

A1 O

Fe208 ..................

Salinity, parts per million................. .

A

51.64

7.90

.59

29.10

5.11

1.60

2.00

2.06

100. 00 

141

H

36.15

16.33

5.60

1.66

22.58

4.26

4.10

1.66

.6.47

} 1.19

100. 00 

126

B

48.60

14.63

.08

30.54

4.71

}

18 .1.

1.26

100. 00 

213

I

41.83

14.89

5.00

.71

23.91

5.85

2.64

1.75

3.10

} .32

100. 00 

194

C

53.05

7.96

.57

33.53

2.87

}

7<s

1.29

100. 00 

166

J

39. 69

15.46

4.76

1.43

23.07

5.52

2.86

2.04

4.69

} .«

100. 00 

147

D

36.69

8.38

.52

1.00

25.30

.61

2.17

.66

21.07

1.09

2.51

100. 00 

232

K

34.39

26.41

4.69

23.56

6.90

1.73

1.90

\ 42 I " 42

100. 00 

240

E

41.12

11. 13

3.65

1.63

(a)

31.81

3.95

2.08

1.05

2.69

} .89 '

100. 00 

 178

L

35.85

24.69

1.91

2L8i

7.30

1.25

trace

6.67

I 50

F . O4

100.00 

221

F

46.96

12.95

4.22

.24

26.48

6.15

2.73

.02

.15

.04

.06

100. 00 

190

M

29.43

22.43

8.39

1.12

(a)

19.57

5.77

6.64

1.44

4.12

QQ

.10

100. 00 

299

G

35.79

12.23

7.10

26. 18

3.84

6.34

4.04

3.59

}- .89 '

100. 00 

159

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 with AhOs, etc.
90 THE DATA OF GEOCHEMISTRY.

These analyses are evidently of very unequal value. The high 

silica found in the Khine by Deville is suspicious, and yet Deville was 

an accurate manipulator.

One of the most thorough hydrochemical studies ever made of any 

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 ievf analyses are also given from 

a rich mass of data derived from other authorities.2

Analyses of the Elbe and its tributaries.

A. The Moldau above Prague. Mean of three analyses by A. Bglohoubek, Sitzungsb. K. b8hm. Gesell. 

Wiss., 1876, p. 27.

B. The Moldau below Kralup.

C. The Adler near its mouth.

D. The Iser at its source.

E. The Iser near its mouth.

F. The Eger at its source. Analysis by E. Spaeth, Inaug. Diss., Erlangen, 1889.

G. The Eger above Konigsberg.

H. The Eger near its mouth, at Bauschowitz.

I. The Saale near its source. Analysis by Spaeth, loc. cit.

J. The Saale at Blankenstein. Analysis by A. Schwager, Geognost. Jahreshefte, 1891, p. 91. Schwager 

also gives analyses of the Saale at three other points, of its tributaries the Pulsnitz, Schwesnitz, Regnitz, 

and Selbitz, of the Eger, and of the upper Main.

K. The Weisswasser, one of the two chief sources of the Elbe.

L. The Elbe at Celakowitz, above the mouth of the Iser.

M. The Elbe at Melnik, above the mouth of the Moldau.

N. The Elbe at Leitmeritz, above the Eger.

O. The Elbe at Lobositz, below the Eger.

P. The Elbe at Tetschen, near the Bohemian frontier.

The analyses are by Hanamann, except where otherwise stated.

1 Archiv Natur. Landesdurchforschung Bo'hmen, vol. 9, No. 4,1894; vol. 10, No. 5,1898.

2 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. Ullik (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, Jahresber. Chemie, 1880, p. 1521. According to A. Schwager (Geognost. Jahreshefte, 1891, p. 35), 

the Saale carries out 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 fur Wasserversorgung, Heft 9, Berlin, 1907, p. 1."
LAKES AND KIVBES. 91

003...................

S04 ..................

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

N03 ..................

PO ru4 ..................

Ca....................

Mg....................

Na...................

K............... ......

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

(AlFe)203 . ............

Salinity, parts per million............ .....

rc\

S04 . .................

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

TMO

N03 ........ ..........

Ca........... .........

Mg....................

Na.... ...............

K.............. .......

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

Al O

FeA- ...............

Salinity, parts per million.... ............

A

32.86

11. 95

10.69

.47

13.52

4.88

10.22

5.19

8.96

1.26

100. 00

74

I

14.71

5.84

19.40

4.02

6.37

9.90

4.66

35.10

itraces

100. 00 

17

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

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

C

46.23

7.44

3.20

1.43

26.73

2.45

4.29

2.38

5.53

.32

100. 00 

195

K

16. 84

12.86

7.61

4.28

8.76

2.19

11.06

2.01

31.21

} 3.18

100. 00 

13

D

21.29

6.94

11.08

1.24

8.14

2.19

13.86

5.54

28.39

1.33

100. 00 

16

L

45.87

8.95

3.27

.90

26.41

3.21

3 93

2.46

4.09

1 91 r - yi

100. 00 

221

E

47.74

6.55

3.00

.78

28.15

2.47

3.71

2.01

4.96

.63

100. 00 

183

M

45.04

8.88

3.56

.94

26.37

2.77

4.02

3.06

4.66

} .70

100. 00 

205

F

11.68

7.06

23.85

6.79

2.24

11. 93

6.71

26.07

3.67

100. 00

17

N

40.27

10.86

5.00

1.22

22.87

3.24

5.62

2.79

7.27

. 00

100. 00 

157

' G

26.64

19.22

8.16

.50

12.86

3.51

11.66

2.98

12.19

2.28

100. 00 

80

0

38.41

12.45

5.96

1.28

22.19

3.23

6.35

2.87

6.42

1 84 r >H4

100. 00 

153

H

26.84

27.45

6.55

.46

15.42

4.05

10.46

3.50

4.17

1.10

100. 00 

176

p

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 gradually 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 in 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 

Schladabach 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.
92 THE DATA OF GEOCHEMISTRY.

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 their sources.

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.

003..................................

S04 .. .................................

01...... .................... .........

Ca................... ..................

Mg...................................

Na..... ....... ........................

K...... ..............................

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

FeA------------.----------- ----------

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 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 when otherwise stated the 

analyses are by A. Schwager. 1

Analyses of water from the Danube and its tributaries.

. A. The Woernitz above Wassertriidingen, Bavaria.

B. The Altmuhl above Herrieden, Bavaria.

Analyses A, B, by E. Muller, Inaug. Diss., Erlangen, 1893. Other dissertations upon Bavarian waters 

are by E. Kohn; 1889, M. Lechler, 1892; J. Mayrhofer, 1885, all from Erlangen. Spaeth'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. TheNaab.

D. The Regen. For older but incomplete analyses of the Regen, Ilz, and Rachelsee, see H. S. Johnson, 

Liebig's Annalen, vol. 95, 1855, p. 230. An analysis of 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, Jahresber. 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, an d 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. TheErlau.

J. The Danube above the Naab.

K. The Danube above Regensburg.

L. The Danube above the Ilz 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. Chemie, vol. 4,1883, p. 417.

O. The Danube at Budapest. Analysis by M. Ballo, Ber. Deutsch. chem. Gesell., vol. 11,1878, p. 441. 

Bicarbonates are here reduced to normal salts.

' Geognost. Jahreshefte, 1893, p. 84. In Schwager's analyses the iron is given as FeO. It is here 

recalculated into FeaOa. Traces of Mn, TiO2, and PsOs are ignored.
LAKES AND KIVEES. 93

C08 ............ .......

80t... ...............

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

N02 ... ............... NOs-.. .:............

Ca....................

Mg :. ................

Na...................

K. ..................

SiO, .................

A12 03 ---- --- ----------

FeA.......... .......

Salinity, parts per 

million... ..........

CO,.. ................

S04 ....

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

N0a ...................

N08 ...................

Ca. ..................

Mg...................

Na...... ..............

K........ ............

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

A1Al O 2U3 ................

Fe203 - ---------------

Salinity, parts per

A

41.14 

19.36 

3.66

21.81 

7.54 

2.37 

2.29 

1.28 } «;

100.00 I 

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 

6.50 

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

48.29 

10.52 

2.25 

.06 

1.19 

25.46 

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

167

H

44.85 

14.40 

2.20 

.09 

.28 

25.10 

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

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

' For three small lakes near Halle and Elsleben 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.
94 THE DATA OF GEOCHEMISTRY.

Analyses of water from central Europe.

A. The Weser at Rekum, 41 kilometers above its mouth. Mean of two analyses by F. Seyfert, Inaug. 

Diss. Rostock, 1893. Contamination, tidal or other, seems to be evident.

B. The Oder near Breslau. Sample taken at high water. Analysis by 0. Luedecke, Das Wassei* des 

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 der chemischen und physikalischen Geologie, 2d ed., 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. 6. Reduced from bicarbonate form.

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

S04 ...........................................

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

Ca............ ................................

Mg............................................

Na ...........................................

K.............................................

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

A1203 ---- ................................... --

Fe.,0..........................................

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

5.46

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

1 .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 0. Hofman-Bang. 1 The month in which the 

water was taken is given for each analysis.

Analyses of Swedish waters.

A. The Byske-elf, July. 

B. The Klarelf, April. 

C. The Klarelf, October.

D. The Ljusnan, June.

E. The Indalself, June. 

F. The Fyris, April. 

G. The Fyris, October.

nrj

S04 ........ ...........

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

NO

PO ru4 ...................

Ca ...................

Mg...................

Na....................

K.................... sio2 .......:.........

(AlFe)A- -----------

Salinity, parts per milA

50.60

4.01

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

} 18. 77

10 OQ

2.29

100. 00 

27.6

C

38.68

7.63

2.24

.46

11. 67

.51

8.42

3.78

1Q Y7

7.44

100. 00 

25.5

D

43.11

4.57

4.53

17.34

.24

9.05

5.87

13.70

1.59

100. 00

24.8

E

43.93

7.24

3.81

18.04

.38

11.33

4.89

5.78

4.60

100. 00 

33.7

F

29.14

24.58

3.15

27.49

1.69

2.92

2.36

6.00

2.67

100. 00 

170.3

G

14.30

39.08

3.27

.13

27.99

2.11

3.33

1.73

fi 1Q

1.87

100. 00 

178.1

i 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.
LAKES AND RIVERS. 95

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 oj Russian waters.

A. The Angernsee. Mean of two analyses.

B. TheBabitsee.

Analyses A and B by F. Ludwig, Die Kiistenseen des Rigaer Meerbusens, published by the NaturforscherVerein at Riga, 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 are all by C. Schmidt of Dorpat.

C. Lake Onega. M61. chim. phys. St. Petersburg Acad., vol. 11,1882, 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. See Melchlm. phys., vol. 8,1873, 

p. 494.

E. The Dwina at Archangel. Analysis cited by J. Koth, Allgem. chem. Geoi., vol. i, 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. Dragendorff, Jahresber. Chemle, 1863, p. 885.

Analyses of five Finnish river and lake waters are given by 0. Aschan, Jour, prakt. Chemie, 2d ser., 

vol. 77, 1908, p. 172. For an-analysis of the small Lake Ingol, Government of Yeneseisk, Siberia, see 

S. S. Zaleski, Chem. Zeitung, vol. 16,1892, p. 594.

on

S04 .................. ci............... ......

N08 ...... ............

PO

Ca. ...................

M<*

Na. ..................

K. ....................

Eb...................

NH4 .:..... ...........

8iOa ..................

AlA....... ..........

FeA......... ........

Salinity, parts per

A

51.80

7.51

2.99

23.57

7.89

2.18

1.00

1.61

.57

.88

100. 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 

106

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

1.46

100. 00 

69

H

32.51

23.62

8.93

25.25

5.33

.61

3.75

100.00 

197
96 THE 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. 26, 1873, 

p. 229. Fe recalculated into FeaOs. 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.

/-i/~l

so4 . ......................................... ci........... ..................................

N03 ............... ...........................

PO

Ca............................................ MS.. ..........................................

Na...........................................

K................. ............................

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

AI n

Fe203 -----------------------------------------

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. '

The water of the Nile 2 has been repeatedly analyzed, with varying 

results. The best data are as follows:

Analyses of water from the Nile.

A. The White Nile near Khartoum. Average of three analyses.

B. The Blue Nile. Average of three analyses. Analyses A and B by W. Beam, Second Eept. Wellcome 

Research Lab., Khartoum, 1906.

C. Average of twelve 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. 60,1880, p. 376. 

The total solids contained 10.36 per cent of organic matter.

D. 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.

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 Ch61u the river carries past Cairo annually 

51,428,500 metric tons of suspended solids and 20,772,400 metric tons hi solution. On nitrates in the Nile 

see A. Muntz, Compt. Rend., vol. 107,1888, p. 231.

2 Analyses of the other great African rivers seem to be lacking. For the Chelif and references to some 

smaller Algerian streams see p. 63 of this bulletin.
LAKES AND RIVERS. 97

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

S04 . ......................................... ci... ...........................................

NO

PO ru4 ..........................................

Ca. ...........................................

Mg..... .......................................

Na. ..........................................

K.............................................

SiOa ................................ ...........

FeaOa....... ..................................

A

42.97

.25

4.58

.25

9.78

3.00

17.66

6.79

14. 72

100. 00 

174

B

41.74

5.62

2.19

.11

18.38

4.66

5.43

1.32

20.55

100. 00 , 

130

C

36.50

17.44

4.47

trace

trace

20.10

4.01

3.04

7.97

} 6.47

100. 00 

168

D

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 verypeculiar, and at least improbable. 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 dissolved 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.

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

Danube.......................... 3. 25

James............................ 4.14

Maumee........................ 4.55

Nile....-........-.......-...--- 10.36

Hudson.......................... 11. 42

Rhine.......................... H-93

Cumberland..................... 12.08

Thames......................... 12.10

Genesee.......................... 12.80

101381° Bull. 491 11 7
98 THE DATA OF GEOCHEMISTRY.

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 

or 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 accurately known, but it 

consists in great part of a vague group of colloidal substances, whose 

precise nature is }^et to be made out. They appear to possess feebly 

acidic properties, and have therefore received specific names, humic, 

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 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.

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 Uruguay 

River is so far the extreme example 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 they can dissolve silica when alkalies are absent. As 

colloids they are more likely to precipitate silica than to bring it 

into solution.

In fact, the amount of silica in a water is quite independent of 

organic matter. Many small streams, near their sources, especially 

if they rise from crystalline rocks, carry a large relative proportion

1 See A. A. Julien, Proc. Am. Assoc. Adv. Sci., vol. 28,1879, p. 311. On the organic matter of waters in 

Finland, see 0. Aschan, Zeitschr. prakt. Geologie, vol. 15,1907, p. 56. On the chemical nature of the 

organic matter in soils, see O. Schreiner and E. C. Shorey, Bull. Bur. Soils No. 74, U. S. Dept. Agr.

2 A. Rodzyanko, Jour. Chem. Soc., vol. 62, pt. 2,1892, p. 1373. Abstract from Jour. Russ. Chem. Soc., 

vol. 22, p. 208.

3 Uompt. Rend., vo!. 70,1870, p. 1412.
LAKES AND EIVEKS. 99

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 in salinity but relatively high in 

silica and alkalies may almost certainly be attributed to igneous 

rather than to sedimentary surroundings. This silica is directly 

derived 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 afterwards 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.

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 OUT immediate purposes, best measured by the proportion of chlorine. A good 

example is furnished by the Chicago drainage canal, which empties 

into the Desplaines River and thence passes through, the 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 myself, and the table is to be read going downstream.

Total solids and chlorine in Illinois and Mississippi rivers.

Illinois River 

At Ottawa. ...................................

At Kampsville. ..............................

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.

Parts 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, arid 100 feet from 

the Missouri shore. The figures represent averages covering periods 

of from nine months to nearly the entire year 1900.

i Chemical survey of the waters of Illinois, 1897-1902, Univ. Illinois, 1903.
100 THE DATA OF GEOCHEMISTRY.

Total solids and chlorine in Mississippi River at Alton, III.

Midstream. . .....................................

Three-fourths distance across. .......................

Total 

dissolved 

solids.

Parts per 

mittion. 

194.1 

182.8 

160.6 

155.0 

154.2

Chlorine.

Parts per 

mittion. 

7.7 

7.1 

4.4 

4.1 

3.5

Per cent. 

3.97 

3.87 

2.74 

2.65 

2.27

The influence of the 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 Kaiikakee at Wilniington the proportion of chlorine during the same period was only 1.21 

per cent, and in the Fox River it was 1.98 per cent, calculated from 

the total matter in solution. The 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 crustaceans, mollusks, and some aquatic plants, withdraw calcium carbonate from solution; but how great their influence

i A good summary of the relations between normal and polluted waters in the eastern and middle States 

isgivenbyM.O.Leightonin 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 Kept. Rivers Pollution Commission, 1868, on the domestic water supply of Great Britain. 

This report contains abundant data on chlorine in waters.
LAKES AND BIVERS. 101

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 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 mam 

divisions still hold. Most 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 rain 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.

1 See N. Zelinsky, Jour. Chem. Soc., vol. C6,pt.2,1894, abstract, p. 200; also M. W. Beyerinck, idem, vol. 

80, pt. 2, abstract, p. 119; and R. H. Saltet and C. S. Stockvis, idem, vol. 80, pt. 2,1901, p. 265.
102 THE DATA OF GEOCHEMISTRY. 

CHEMICAL DENUDATION.

Now, to sum up: A river is formed by the union of waters from 

many sources, 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 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 nineteen 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 Eeade, 2 for instance, in a well-known investigation, has 

calculated the amount of solid matter annually dissolved by water 

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

1 Scottish Geog. Mag., vol. 3,1887, p. 65.

2 Proc. Liverpool Geol. Soc., vol. 3,1876-77, p. 211. Reprinted under the title "Chemical denudation in 

relation to geological tune."
LAKES AND BIVEKS. 103

of surface. At this rate, by the solvent action of water alone, the 

level of England and Wales would be lowered 1 foot in 12,978 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

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.

North Atlantic. . ........................................

North Pacific. . ..........................................

Total. ...........................................

Area drained 

(square miles).

159, 400

123, 900

142, 100

315, 700

1, 265, 000

175, 000

230, 000

72, 700

270, 000

2, 753, 800

Dissolved solids 

(tons per square 

mile).

130

Q4

117

36

108

116

51

177

100

a 98

a Short tons of 2,000 pounds. The metric ton equals 2,205 pounds.

For the entire United States, 3,088,500 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

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, V irginia (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.
104 THE DATA OF GEOCHEMISTEY.

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 the rest of North America only a rough estimate is possible. 

The analyses of Canadian rivers 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 2 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, and through much of its course has scanty access to fresh 

rocks. It waters a region which is thoroughly leached, and therefore finds but little material to dissolve. Large areas in South 

America, like Peru and central Argentina, contribute nothing to the 

ocean and count for zero in measuring chemical denudation.

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 Frost give a factor of 139 tons.

1 Dole and Stabler's figure for the denudation factor of the Mississippi is considerably larger than that 

derived from Greenleaf's data and the analyses cited on pp. 70, 71, ante.

2 Evolution of earth structures, London, 1903, pp. 255-282.
LAKES AND RIVERS. 105

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 

of 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 

characteristics of those from the humid areas of the United States. 

In the latter the denudation factor is lowered by the arid regions of 

the 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 Saint 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 three millions of square miles to average like Europe, 

three millions like the United States, and one million 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

i Le Nil, 1'Egypte, le Soudan, Paris, 1891.
106 0?HE DATA OF GEOCHEMISTRY.

of the world is 2,735,000,000 metric tons annually, an estimate only 

a little more than half that given by Murray.1 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 

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 waters.

A. Waters of North America. Average computed from the data given by Dole in Water-Supply Papei 

236, and by Dole and Stabler in Water-Supply Paper 234. Each analysis is weighted proportionately to 

the total amount of material annually carried by the river. The alkalies are given with Palmer's determinations of potassium.

B. 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 Rio de la Plata is left out of account, for the analyses 

are not conclusive.

C. Waters of Europe. Average of 300 analyses of river and lake waters, first by groups, and then weighting each group proportionally 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 which 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, 1887, p. 65), as 

reduced to the uniform standard adopted in this book.. Organic matter as given by Murray is 10.37 per 

cent of the total solids.

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

so4 ...................

CL. ..................

N03 ... ................

Ca.....................

Mg. ..................

Na.......... ..........

K....................

(FeAl)A---------

SiOa ...................

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

9.51

100. 00 

11

E

32.75

8.67

5.66

.58

19.00

2.68

4.90

2.35

5.52

17.89

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

» 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 BIVEBS, 107

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 

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 one 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 N03 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; 1 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 per cent 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 C02 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 limestones, but if we accept 

the ratio as it stands we may use it to determine the approximate 

proportions of the CO3 radicle derived from limestones and from the

1 Estimate by A. von Tillo, actually 75.7 and 24.3.
108 THE DATA OF GEOCHEMISTRY.

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 

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 hi the next chapter in relation to 

the use of the data hi measuring geologic time.

1 Spring and Prost, in their work on the Meuse, and Uilik, in his study of the Elbe, have attempted to 

measure the amount of human contamination. This, obviously, must be very variable. In rivers like 

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 the amount 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 an iodate. 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 much smaller quantities.

Fluorine. Found directly, and also in the boiler scale of oceanic 

steamers. A. Carnot's determinations 6 show that the water of the 

Atlantic contains 0.822 gram of fluorine to the cubic meter. 7 P. 

Carles 8 has reported fluorine in the shells of mollusks.

Nitrogen. Present as ammonia, in organic matter, and in dissolved 

air. The ammonia of sea water has been repeatedly investigated.

i For the volume of the ocean and of Its contained salts, see ante, pp. 22, 23.

«Phil. Trans., vol. 155,1865, pp. 203-262. See also J. Roth, Allgemeine und chemlsche Geologie, vol. 1,1870, 

p.400; and W. Dittmar, Kept. Challenger Exped., Physics and chemistry, vol. 1,1884, pp. 1-251. A volume 

by Ren6 Quinton (L'eau de mer, 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.

a Chem. News, vol. 74,1896, p. 316.

< Compt. Rend., vol. 128,1899, p. 1069; vol. 129,1899, p. 9.

6 Zeitschr. anal. Chemie, vol. 17,1878, p. 305. 

o Annales des mines, 9th ser., vol. 10,1896, p. 175.

7 See also earlier determinations by G. Forchhammer and G. Wilson, Edinburgh New Phil. Jour., vol. 

48,1850, p. 345.

8 Compt. Rend., vol. 144, 1907, pp. 437, 1240.

109
110 THE DATA OF GEOCHEMISTRY.

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 further on 

in this chapter.

Arsenic. Detected by Daubree. A. Gautier 6 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 probably 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 also in the ashes of marine 

plants. J. A. Veatch,9 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. Determined quantitatively by Schmidt, whose analyses will be cited later.

Csesium. Also found by Sonstadt.

Barium and strontium. Can be detected by ordinary methods. 

Also found in the ashes of seaweeds and in boiler scale.11

1 Compt. Rend., vol. 81,1875, p. 619.

2 Annales cMm. phys., 5th ser., vol. 14, 1878, p. 380. Dieulafait mentions earlier work by Marchand 

and Boussingault.

a Contributions a l'6tude de la chimie agricole, in Fremy's Encyclopedic cblmiqu'e, 1888. 

< Proc. Roy. Soc. Edinburgh, vol. 17,1889, p. 89.

6 Monatsh. Chemie, vol. 14,1893, p. 675; vol. 15,1894, p. 596; vol. 16,1895, p. 591; vol. 20,1899, p. 1. See 

also E. Raben, Wissenschaftlichen Meeresuntersuchungen, vol. 11, Kiel, 1910, p. 303. Many determinations are given, and also a full summary of earlier work.

« Compt. Rend., vol. 137,1903, pp. 232,374.

7 Proc. Roy. Soc. Edinburgh, vol. 18,1891, p. 229.

s Wissenschaftlichen Meeresuntersuchungen, vol. 11, Kiel, 1910, p. 311.

9 Proc. California Acad. Sci., vol. 2,1859, p. 7.

10 Annales chim. phys., 5th ser., vol. 17, 1879, p. 377. See also Thorpe and Morton's analysis of water 

from the Irish Sea, 1871, cited on pp. 112,113. 

" On strontium in sea water see Dieulafait, Compt. Rend., vol. 84, 1877, p. 1303.
THE OCEAN. Ill

Aluminum and iron. Easily detected by direct methods.

Manganese. Easily detected. Noted by Forchhammer and also 

by Dieulafait.1 Concretions of manganese oxide are abundant over 

portions of the sea bottom. Reported by E. Maumene12 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.3 Also in the ashes of seaweeds and in certain corals.

Zinc. Reported in sea water by Dieulafait.4 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. According to A. 

Liversidge,5 silver is present hi 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 6 in 1872. Its presence has since been repeatedly 

verified. In 1892 C. A. Munster 7 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 8 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 9 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 10 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 11 found, also per metric ton, 11.1 milligrams 

of gold and 169.5 of silver. In deep-sea dredgmgs Wagoner 12 

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

1 Compt. Kend., vol. 96,1883, p. 718.

a Idem, vol. 98,1884, p. 1417.

3 Annales chim. phys., 5th set., vol 18,1879, p. 359.

< Idem, vol. 21,1880, p. 266.

6 Proc. Roy. Soc. New South Wales, vol. 29,1895, pp. 335, 350.

«Chem. News, vol. 25,1872, pp. 196, 231, 241; vol. 74,1896, p. 316; Am. Chemist, vol. 3,1872, p. 200.

7 Jour. Soc. Chem. Ind., vol. 11,1892, p. 351. From Norsk Tekn. Tidsskr.

8 Proc. Roy. Soc. New South Wales, vol. 29,1895, pp. 335,350.

9 Jour. Chem. Soc., vol. 71,1897, p. 298.

10 Trans. Am. Inst. Mm. Eng., vol. 27,1897, p. 615.

" Idem, vol. 31,1901, p. 806.

^Idem, vol. 38,1907, p. 704. P. DeWilde (Arch. sci. phys. nat., 4th ser., vol. 19,1905, p. 559) and A. 

Wiesler (Zeitschr. angew. Chemie, 1906, p. 1795) have published good summaries relative to the detection 

of gold in sea water, and also discussed the possibility of its economic recovery.
112 THE DATA OF GEOCHEMISTRY.

the amount of radium is inferred. 1 According to Joly, 1 cubic 

centimeter of sea water, on the average, contains 0.017 XlO~~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: 2

Analyses of oceanic salts.

A. Mean of 77 analyses of ocean water from many localities, collected by the Challenger expedition. 

W. Dittmar, analyst. Challenger Kept., Physics and chemistry, vol. 1, 1884, p. 203. Salinity 3.301 to 

3.737 per cent.

B. Atlantic water, mean of 22 samples collected on a voyage from the Cape of Good Hope to England 

C. J. S. Makin, Chem. 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. 142,1906, p. 320. Salinity 

32.420 grams per liter.

D. The Irish Sea. Analysis by T. E. Thorpe and E. H. Morton, Liebig's Annalen, vol. 158,1871, p. 122. 

The small amounts of Fe3 03, NH3 , and NaO5 are here added together. A trace of lithium was also 

reported.

E. The Baltic Sea between Oeland and Gothland. Analysis by C. Scbmidt, 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, PO4 , and SiO2 found by Schmidt are 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 F. Lahille, reported by E. H. Ducloux, An. Soc. cient. 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.

1 See R. J. Stratt, Proc. Roy. Soc., vol. 78A, 1907, p. 151; A. S. Eve, Phil. Mag., 6th sen, vol. 18,1909, 

p. 102; J. Joly, idem, vol. 15,1908, 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.

2 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. bo'hm. Gesell. 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. Berglund, Ber. Deutsch. chem. Gesell., vol. 18, 1885, p. 2888. 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. Vierthaler (Sitzungsb. Akad. 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, 3d 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.
THE OCEAN. 113

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. Schrnelck, 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 Zembla. Mean of two analyses by Schmidt, 

loc. cit.

L. The Siberian Ocean. Water collected by the Vega expedition. Mean of four analyses by Forsberg, 

Vega Exped. Kept., vol. 2,1883, p. 376. 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, midsea, 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 hero are the 

average from 42 analyses which were fairly complete. Salinity, 3.83G to 4.115 per cent.'

P. The Sea of Marmora. Natterer, Monatsh. Chemie, vol. 1C, 1895, p. 405; 44 partial analyses. Natterer 

gives the figures here xitilized as averages of varying numbers of determinations. Mg, Na, and K not 

determined. Salinity, 2.310 to 4.061 per cent.

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

Br........... .........

S04 . ................. co8 ...................

Na.......... .........

K....... ..............

Kb.......... .........

Ca...... ..............

Mg....... .............

Fe, Si02 , P04 .........

Fe, NH4 , N03 .........

(FeAl)203 , Si02 ........

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

Br............ ........

S04 ...... ............ cos-..:.. ............

Na...................

K............... ......

Rb....... ............

Mg.............. ......

Fe,Si02) P04 .........

A

55. 292 

.188 

7.692 

.207 

30. 593 

1.106

1.197 

3.725

100. 000

I

155. 46

7.59 

.30 

30.53 

1.12

1.21 

3.79

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

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

D

55.21 

.19 

7.69 

.09 

30.82 

1.16

1.21 

3.61

.02

100. 00

L

1 55. 45 

7.79

30.41 

1.17

1.18 

3.82

100. 00

E

55.01 

.13 

8.00 

.14 

30.47 

.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

F

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 

3.65

100. 00

G

55.24 

.17

7.54 

.34 

30.80 

1.10

1.22 

3.59

100. 00

0

55.30 

.16 

7.72 

.19 

30.51 

1.12

1.19 

3.81

100. 00

H

55.25

7.56 

.37 

30.76 

1.14

1.22 

3.70

100. 00

F

55.45 

.17 

7.67 

.28

1.22

101381° Bull. 491 11 8
114 THE DATA OF GEOCHEMISTBY.

. Q. The Black Sea. Average of six analyses by S. Kolotoff, Jour. Russ. Phys. Chem. Soc., vol. 24, 

1893, p. 82. Salinity, 1.826 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-Claye, Annales chlm. 

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, 1899, 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 5.854 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. chim., vol. 10, p. 594. Also Jahresber. 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. Analysis by W. Loebisch and L. Sipocz, 

Min. Mitt., 1876, p. 171.

ci...................

Br........... ..........

S04 ..................

C03...................

Na....... ............

K....... ..............

Rb.................

Ca.......... ..........

Mg.............. ......

Fe,Si02 , P04 .........

Q

55.12

.18

7.47

.46

30.46

1.16

i.41

3.74

100. 00

R

55.59

.14

7.67

.01

31.21

.64

.03

1.05

3.64

.02

100. 00

S

55.60

.13

7.65

.02

30.81

.97

.04

.89

3.87

.02

100. 00

T

5.5. 96

.18

7.49

.13

30.31

1.06

1.22

3.65

100. 00

U

55.46

.13

7.91

.04

30.23

.94

.03

1.19

4.03

.04

100. 00

V

55.43

.13

7.76

.03

30.67

.97

.04

1.19

3.75

.03

100. 00

W

55.41

.13

7.79

.05

30.89

.85

.03

1.16

3.67

.02

100. 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 

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
THE OCEAN. 115

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 O. 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.

A. Liquid intermingled with snow, collected on Arctic ice at 32°. 

B. Another sample free from snow, also collected at 32°.

Cl+Br.... .:.......... ......................................... so4 . ..........................................................

Na. ...........................................................

K..............................................................

Ca.. ...........................................................

Mg... ......... .................................................

A

62.47

1.26

25.88

Q7

2.00

7.42

100. 00

B

63.52

.82

27.85

1.06

1.51

5.24

100. 00

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

1 Natterer also, in the memoirs already cited, discusses the relations between density and salinity. So,. 

too, does H. Tomoe in Den Norske Nordhavs-Expedition, 1880. See also memoirs by A. Bouquet de la 

Qrye, 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.

2 Vol. 2,1882, pp. 948-1003.

3 Vega Exped. Kept., vol. 2,1883, pp. 349-380. 

* See 0. Pettersson, op. cit., 1883, p. 376.
116 THE DATA OF GEOCHEMISTRY..

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

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

1 Proc. Roy. Soc. Edinburgh, vol. 17,1889, pp. 100-101.

2 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. 14,190G, p. 221, and A, B. Macallurn, Trans. Canadian 

Jnst., vol. 7,1903, p. 535.
THE OCEAN. 117

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 

re-solution, however, occurs, especially where the waves have beaten 

the coral into sand, and this subject has been well studied by J. 

Murray and R. Irvine. 3 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, CaH2C206 is then formed, a compound which is 

only known in solution. Of this salt, as shown by F. P. Treadwell 

and M. Reuter,4 a liter of pure water at 15° can dissolve 0.3850 gram, 

a quantity which may be considerably increased by an excess of

» Compt. Eend., vol. 74,1872, p. 1552.

2 Proc. Eoy. Soc. Edinburgh, vol. 15,1888, p. 316. For other data on the solubility of calcium carbonate 

in sea water, see W. S. Anderson, Proc. Eoy. Soc. Edinburgh, vol. 16,1889, p. 318; and J. Thoulet, Compt. 

Eend., vol. 110, 1890, p. 652.

s Proc. Eoy. Soc. Edinburgh, vol. 17,1889, p. 79.

«Zeitschr. anorg. Chemie, vol. 17,1898, p. 170.
118 THE DATA OF GEOCHEMISTRY.

carbon dioxide in the water. In sea water this solubility is modified 

by the presence of other compounds. E. Cohen and M. Raken,1 

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 CaCO3 . According to G. Linck, 2 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.3 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 

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 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 Challenger expedition there 

is much valuable information on this point.4 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 indicated 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

1 Proc. Sec. Sci., Amsterdam Acad., vol. 3,1901, p. 63.

a Neues Jahrb., Beil. Bd. 16,1903, p. 505.

»W. Dittmar, Challenger Kept., Physics and chemistry, vol. 1,1884, p. 211.

1 See summary in vol. 2 of the Narrative, 1882, pp. 948 et seq.
THE OCEAN. 119

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, 1 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.2

In this system of gains and losses some otherwise unimportant 

constituents of sea water play an interesting part. Radiolarians, 

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.3 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 

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.4

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 substances that do 

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. 5 The larger deposits may be classified as follows:

»See J. Murray and R. Irvine, Proc. Roy. Soc. Edinburgh, vol. 17,1889, p. 79.

a 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.

»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.

* A recent treatise by L. W. Collet (Les d6p6ts marins, Paris, 1908) deals with this subject quite fully.

8 See also J. Murray, Geog. Jour., vol. 19,1902, p. 691; on material collected in 1901 by S. S. Britannia.
120 THE DATA OF GEOCHEMISTRY. 

Deposits on the ocean floor.

Name.

Radiolarian ooze ......................................

Pteropod ooze ........................................

Average depth 

in fathoms.

2,730

2,894

1 477

2,049

1 044

Percentage of 

CaC03 .

6.70

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:

Percentage of calcium carbonate on the ocean floor at various depths.

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

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, 

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 subaerial 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 fragments studied by Murray ana 

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
THE OCEAN. 121

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 preceptibly 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 ejectamenta 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.

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 

substance as a nucleus. 3 Even in shallow waters, as in Loch Fyne in 

Scotland, these nodules have been found,4 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 5 regards the manganese as derived, like the red 

clay, from the subaqueous decomposition of volcanic d6bris. C. W. 

Gumbel 6 attributes the nodules to submarine springs holding manganese in solution, which is precipitated on contact with sea water. 

Buchanan 7 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 oxidized. This 

view was contested by R. Irvine and J. Gibson,8 who showed that 

manganese sulphide was decomposed by sea water, the manganese 

redissolving as bicarbonate. J. B. Boussingault ° holds that the manganese was derived from carbonates carried in solution by oceanic 

waters, and a similar explanation has been offered by L. Dieulafait.10

» Compt. Rend., vol. 108,1889, p. 753. See also recent work by J. Joly, in Compt. rend. VIII. Cong. gfiol. 

internat., 1900, p. 774.

a Proc. Roy. Soc. Edinburgh, vol. 16,1889, p. 172.

^ For full description see Challenger Rept., Deep-sea deposits, 1891\ pp. 341-378. See also J. Murray and 

R. Irvine, Trans. Roy. Soc. Edinburgh, vol. 37,1895, p. 721.

* J. Y. Buchanan, Proc. Roy. Soc. Edinburgh, vol. 18,1890, p. 19.

6 Proc. Roy. Soc. Edinburgh, vol. 9,1876, p. 255.

6 See abstract in Neues Jahrb., 1878, p. 869.

7 Proc. Roy. Soc. Edinburgh, vol. 18,1890, p. 17.

8 Idem, vol. 18,1890, p. 54.

9 Annales chim. phys., 5th ser., vol. 27,1882, p. 289. 

»° Compt. Rend., vol. 96,1883, p. 718.
122 THE DATA OF GEOCHEMISTEY.

The oxidation of the carbonates is supposed to take place at the surface, through atmospheric contact, after which the precipitated oxide 

falls to the bottom of the sea.

Of all these theories, that of Murray seems to be the best substantiated. The manganese can e,asily 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 happened 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 land 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 1 

is the most complete one among the many which were made, and is 

therefore selected as representative. The entire sample contained 

Water..................................................:.... 29. 65

Aqueous extract 2 ............................................ 2. 44

Insoluble residue.......................................'..... 17. 93

Portion soluble in HC1....................................... 49. 97

99.99

The insoluble and soluble portions, recalculated separately, are 

represented in the subjoined statement:

Analysis of manganese nodule.

SiOa .. .................................................

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

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

FejOj... ...............................................

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

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

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

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

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

NiO. ....................... .,. .........................

CoO.....................................................

ZnO. ..................................................

CuO.. .................................................

PbO ..................................................

T120..... ..............................................

Na20. .................................................

K20. ...... ............................................. PA------------------------------------- ..............

v2 o5 .... ....... .......................................

Mo03 .... ...............................................

so3 ... ..................................................

C02 ........ ............................................

'PpToviHp nwcypTi

Portion soluble 

in HC1.

fi <U

26.97

4.60

4.02

42.94

1.96

.56

.20

.74

.10

.06

.22

.14

.20

.94

.58

9.42

99.99

Insoluble 

portion.

74.58

.72

19 Q3

4.79

1.45

.11

.67

3.62

.95

.11

99.93

1 Challenger Rept., Deep-sea deposits, 1891, pp. 417-423.

' Saline matter unavoidably inclosed in the nodules. Gibson gives its composition in detail.
THE OCEAN. 123

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 l 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 Klement,

show the composition of these bodies. A was from a depth of 150 

and B from 1,900 fathoms.

Analyses of phosphatic concretions from sea bottom.

p n

C02 ..... .......................................................

S03 . ............................................................

SiOa .. .........................................................

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

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

Rp O

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

A

19.96

12.05

1.37

1.36

39.41

.67

2.54

1.19

undet.

17.34

95.89

B

23.54

10.64

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 .. .........................................................

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

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

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

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.

i Challenger Kept., Deep-sea deposits, 1891, pp. 397-400. On the phosphatic nodules of the Agulhas 

Bank, see L. W. Collet, Proc. Roy. Soc. Edinburgh, vol. 25,1905, p. 862; and L. Cayeux, Bull. Soo. gdol. 

France, 4th ser., vol. 5,1906, p. 750.
124 THE DATA OF GEOCHEMISTRY.

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 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. 2

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.

1 Murray and Renard, Challenger Rept., Deep-sea deposits, p. 383,1891.

2 E. J. Jones (Jour. Asiatic Soc. Bengal, vol. 56, pt. 2,1887, p. 209) has described another 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. 125

Comparison of ocean and river water.

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 Dittmar's analyses, with Karstens's value for the 

volume of the ocean, 1,285,935,211 cubic kilometers, and a mean density of 1.020.

003...............................................

S04 ..............................................

01.................................................

Br................................................

NO

Na....... .........................................

K........ ..........................................

Ca................................................

Mg................................ ................

R203 ............ ..................................

a 0

SiOa ............. .................................

Sum..................... ..........................

A 

Annual from rivers 

(metric tonsXIO3 ).

961, 350

332, 030

155, 350

24, 614

158, 357

57, 982

557, 670

93, 264

75, 213

319, 170

2,735,OOOX103

B 

In ocean 

(metric tonsXIO12).

95.6

3, 553. 0

25, 538. 0

86.8

14, 130. 0

510.8

552.8

1, 721. 0

46,188. 0X10 l2

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.SX1012 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 

calcium has been 5,528,000 tons; if only 50,000,000 years it is 

11,056,000 tons. Subtracting these quantities from the total cal- / 

cium 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: *

so4 ..................................................

Ca. ...................................................

Mg................ ...................................

K.. ...................................................

RaO,.. ......'......-......................,............. sio2 ........... .......................................

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
126 THE DATA OF GEOCHEMISTRY.

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 geological 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 

ocean 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.

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 19.5 X 1016 metric tons. This estimate is not 

inconsistent with the foregoing computations. Purely mechanical 

sediments, such as river silt, volcanic ejectamenta, 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

1 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.
THE OOEAF. 127 

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 water 

are not at all alike. In river waters, on an average, the proportion 

of potassium is about one-fourth that of the sodium; 1 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 tins 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 2 ordinary soils will extract more potassium than 

sodium from solutions in which the salts of both 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.

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 Challenger 

report contain no mention of alkalies, but when the latter are noted 

the potassium is commonly, not always, in excess.8 In glauconite 

and phillipsite deposits potassium always predominates. L. 

Schmelck,4 in his analyses of clays from the northern Atlantic, records 

no alkalies, but K. Natterer,5 in sediments from the eastern Mediterranean and the Red Sea, found small quantities of potash and soda,

1 Many of the analyses of river water, as published, show no potassium, but this only means that they 

are Incomplete. In such cases the alkalies were weighed together and in calculation the potassium was 

ignored. This is especially true of boiler-water analyses.

a Landw. Versuchs-Stationen (Berlin), vol. 21,1877, p. 135. The absorption of potassium has been established by the work of many investigators.

»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.

« Den Norske Nordhavs-Expedition, pt. 9,1882, p. 35.

» Mqnatsh. Chemie, vol. 14,1893, p.'624; vol. 15,1894, p. 530; vol. 20,1899, p. 1.
128 THE DATA OF GEOCHEMISTRY.

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 their alkalies; but 

some of the potassium from the original volcanic material, with less 

sodium, has been retained in the production of zeolites. Nearer land 

potassium has been used in the formation of glauconite, and still 

nearer, when 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, 1 who finds that the 

giant algas of the California coast are 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.2

To the advocates of the nebular hypothesis the problem is comparatively simple. If our globe was formed by cooling from an incandescent 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,3 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

1 Jour. Indust. and Eng. Chem., vol. 1,1909, p. 777.

2 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 SO* in sea water see E. Ruppin, Zeitschr. anorg. Chemie, vol. 69,1910, p. 232.

3 Am. Jour. Sci., 2d ser., 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., vol. 7,2d ser., 1899, p. 23; and 

R. A. Taylor, Proc. Manchester Lit. Phil. Soc., vol. 50,1906, p. ix.
THE OCEAN. 129

which Hunt regards as fossil remainders from the early sea, may be 

cited in support of his views. On the other hand, K. A. Daly * has 

cited paleontological data in favor of the view that the pre-Cambrian 

ocean was nearly free 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 soft-bodied, 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.2 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 certain meteoric irons have crumbled into masses of rust and disappeared as specimens from museums. 

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. Daubre"e 3 

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,4 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

' Am. Jour. Sci., 4th ser., vol. 23,1907, p. 93. Also a later paper in Bull. Geol. Soc. America, vol. 20,1909, 

p.153.

a See T. C. Chamberlin, Jour. Geology, vol. 5,1897, pp. 653 et seq.; also H. L. Fairchild, Am. Geologist, 

vol. 23,1899, p. 94.

s Etudes synthe'tiques de gfiologie expfirimentale, 1879, p. 557.

«Geog. Jour., vol. 20,1902, p. 520. See also C. Doelter, Sitzungsb. Akad. Wien, vol. 112,1903, p. 704.

101381° Bull. 491 11 9
130 THE DATA OF GEOCHEMISTRY.

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, 2 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.

To illustrate the difference in solubility between the two principal 

atmospheric gases, we may use the data given by O. Pettersson and 

K. Sonde"n.3 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 + 0 = 100.

i Smithsonian Misc. Coll., vol. 56, No. 6,1910. 

. 2 Jour. Soc. Chem. Ind., vol. 23,1904, p. 358.

» Ber. Deutsch. chem. Gesell., vol. 22,1889, p. 1439. See also E. W. Bunsen, Gasometrische Methoden; 

W. Dittmar, in his Challenger report; and A. Hamberg, Bihang K. Svensk. Vet.-Akad. Handl., vol. 10,

No. 13,1884. " 
THE OCEAN. 

Solubility of nitrogen and oxygen in water at various temperatures.

131

Temperature.

0

6.00

6.32

9.18

13.70

14.10

Nitrogen 

absorbed.

cm3 .

19.53

16.34

16.60

15.58

14.16

14.16

Oxygen 

absorbed.

cm3 .

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. Tornoe, 1 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 t.o range from a minimum 

of 31.0 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. 0. Jacobsen,2 

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,3 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 

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 table following.

1 Den Norske Nordhavs-Expedition, Chemistry, 1880, pp. 1-23. Tornoe in this memoir gives a good 

summary of the earlier investigations. '

2 Die Ergebnisse der Untersuchungsfahrten S. M. Knbt. Drache, Berlin, 1886. An earlier memoir by 

Jacobsen is printed in Liebig's Annalen, vol. 167,1873, pp. 1 et seq.

s Challenger Kept., Physics and chemistry, vol. 1,1884. For the table cited below, see p. 224. Also for a 

summary of the results obtained, see the "Narrative " of the expedition.
132 THE DATA OF GEOCHEMISTRY.

' Solubility of nitrogen and oxygen in sea water at various temperatures.

Temperature.

0

5

10

15

20

25 '

30

35

Dissolved 

nitrogens

15.60

13.86

12.47

11.34

10.41

9.62

8.94

8.36

Dissolved 

oxygen."

8.18

7.22

6.45

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

a Supposed to be measured dry, at 0° C. and 760 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 

secondly 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-combined1 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.

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

i. 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 Groenland, vol. 26, 1904, 

pp. 333, 409.
THE OCEAN. 133

the normal calcium carbonate into the acid salt. Tornoe, as the average of 78 sea-water analyses, found 52.78 miligrams 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 

Challenger 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/ 7 free, or halfcombined acid, is more variable. Its average amount, in milligrams

to the liter, at different temperatures appears in the following tablet

Average amount of free carbonic acid in sea water at various temperatures.

Temperature:

25 to 28.7. .................. 35.88

20 to 25...................... 37.18

15 to 20...................... 42. 68

[Milligrams per liter.]

Temperature:

10 to 15...................... 43.50

5 to 10....................... 47.21

-1.4 to+3.2................ 53.31

That is, the ocean contains less free carbonic acid in warm than in 

cold latitudes. Its av.erage 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 depths. 

[Milligrams per liter.]

Surface........................... 42. 6

25 fathoms........................ 33. 7

50 fathoms........................ 48. 8

100 tathoms........................ 43. 6

200 fathoms....................... 44. 6

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 

necessary to form bicarbonates; in only 22 was it sufficient 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

i See vol. 1 of the report on physics and chemistry and part 2 of the "Narrative," p. 979; also J. Y. 

Buchanan, in Proc. Koy. Soc., vol. 22, pp. 192,483,1874. The tables cited are from the "Narrative."
134 THE DATA OF GEOCHEMISTRY.

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 are 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 gams 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 

interesting work of T. C. Chamberlin,2 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

1 Jour. Geology, vol. 7,1899, p. 585. See also memoirs by C. J. J. Fox, Trans. Faraday Soc., vol. 5,1909, 

p. 68; J. Stieglitz, Pub. 107, Carnegie Inst. of Washington, 1909, p. 235; E. Euppin, Zeitschr. anorg. Chemie, 

vol. 66,1910, p. 122. Ruppin discusses especially the alkalinity of sea water.

s Jour. Geology, vol. 5,1897, p. 653; vol. G, 1898, pp. 459, C09; vol. 7,1899, pp. 545, 667, 751. Chamberlin's 

views are criticized by A. Krogh in Meddelelser om Greenland, vol. 26,1904, pp. 333,409.
THE OCEAN. 135

ocean, they are consumed hi 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, \yhereas 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 limesecreting 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.

Chamberlin's theory is ingenious, but may perhaps carry more 

weight if stated in somewhat different form. C. G. Abbot and F. E. 

Fowle,1 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 

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.

1 Annals Astrophys. Observ., vol. 2,1908, pp. 172,176.
136 THE DATA OF GEOCHEMISTRY.

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 their 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 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.

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,4 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

1 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.

a See W. L. Carpenter in C. Wyville Thomson's Depths of the sea, 1874, pp. 502-511. Where C08 was 

abundant in bottom waters, the dredge brought up a good haul of living forms. Where it was deficient, 

the hauls were poor.

3 See J. Murray and R. Irvine, Proc. Roy. Soc. Edinburgh, vol. 17,1889, p. 89.

4 Trans: Roy. Soc. Edinburgh, vol. 37,1895, p. 481. See also Challenger Rept, Deep-sea deposits, 1891, 

p. 254; W. N. Hartley, Proc. Roy. Soc. Edinburgh, vol. 21, 1897, p. 25; and Murray and Irvine, idem/ 

p. 35.
THE OCEAN. 137

process, and according to N. Androussof, 1 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 their 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.2 

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 3 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 

J. Joly 4 in 1899. Joly, with Murray's figures for rainfall, run-off, and

1 Guide des excursions du VII. Cong. g6ol. internal., Mo. 29.

2 See, for example, Chapter I of the present volume, where the relative volumes of the sedimentary rocks 

are estimated.

s Phil. Trans., vol. 29, 1715, p. 296. See an abstract in G. F. Becker's Age of the earth: Smithsonian 

Misc. Coll., vol. 50, No. 6,1910; also in Science, vol. 31,1910, p. 459.

* Trans. Roy. Dublin Soc., 2d ser., vol. 7,1899, p. 23, and with later corrections, Kept. British Assoc. Adv. 

Sci., 1900, p. 369. Criticized by W. Mackie, Trans. Edinburgh Geol. Soc., vol. 8,1902, p. 240; and 0. Fisher, 

Geol. Mag., 1900, p. 124. See also V. von Lozinski, Mitt. K.-k. geog. Gesell. Wien, vol. 44,1901, p. 74. He 

cites a paper by E. von Rorner, 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; H. S. Shelton, 

Chem. News, vol. 99,1910, p. 253; Jour. Geology, vol. 18,1910, p. 190. The presidential address of W. J. 

Sollas (Quart. Jour. Geol. Soc., vol. 65,1909, p. xli) is mainly devoted to this theme. For more details see 

F. W. Clarke, Smithsonian Misc. Coll., vol. 50, No. 5,1910, and G. F. Becker, idem, No. 6. 
138 THE DATA OF GEOCHEMISTRY.

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 uncorrected 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 oi ocean. 

Annual JN a in rivers

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

the crude age of the ocean to which certain corrections are yet to be 

applied. 1 The first of these to be studied tenols 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. 2 Near the sea coast 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 most -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 

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;

1 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 is 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.

2 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.
THE OCEAN. 139

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, like 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 in 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 ^he four hot, dry months, 

sweep over the plains between it and the arm of the sea known as the 

Rann of Cutch. 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 Rajputana. 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.

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 ordinar}^ analyses merely means that they were not

» Chem. News, vol. 89,1904, p. 13. 2 Records Geol. Survey India, vol. 38,1909, p. 154.
140 THE DATA OF GEOCHEMISTRY.

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., is poured into 

the ocean, and so disturbs 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 time 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:

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,

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.
THE OCEAN. 141

excretory in great part, which can not be estimated, but we may 

assume, nevertheless, a maximum of 3 o per cent as the correction to 

be applied. Allowing 6 per cent, as 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 non-fluviatile, 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, 

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

' Presidential address, Quart. Jour. Geol. Soc., May, 1909.
142 THE DATA OF GEOCHEMISTRY.

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

*A valuable summary of the evidence relative to the age of the earth, by J. Joly, appeared in Philos 

Mag., 6th ser., vol. 22,1911, p. 358.
CHAPTER V.

THE WATERS OF CLOSED BASINS. 

PRELIMINARY STATEMENT.

In dealing with the ocean and its tribuatry 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 United States 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 times greater than that of sea water. An early, incomplete 

analysis by L. D. Gale and a questionable one by H. Bassett are

i Q. K. Gilbert, Lake Bonneville: Mon. 1,1890. I. C. Russell, The geological history of Lake Lahontan: 

tMon. XI, 1885.

143
144 THE DATA OF GEOCHEMISTRY.

hardly worth reproducing.1 The other available data, expressed in 

percentages of total salts, are as follows:

Analyses of water from Great Salt Lake.

A. By O.D. Alien,Kept.U.S. Geol.Expl.40thPar.,vol.2,1877,p.433. Water collected in 1869. Atrace 

of boric acid is also reported, in addition to the substances named in the table. Alien also gives analyses 

of a saline soil from 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. Ochsenius also gives an analysis of the salt manufactured 

from the water of Great Salt Lake.

D. By J. E. Talmage, Science, vol. 14,1889, p. 445. Collected in 1889. An analysis of a sample taken in 

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.

F. 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. Zeitung, vol. 32,1908, p. 409. Collected in October, 1907.

H. By W. Macfarlane, Science, vol. 32,1910, p. 568. Collected in February, 1910. A number of other 

analyses, complete or incomplete, are cited in this paper by Ebaugh and Macfarlane.

01.................

Br..'....... .........

S04 ................

003.................

Li..................

Na.... .............

K...................

Ca......... .........

Mg.. ................

Fe203 , A12 03 , SiO,. .

Salinity, per cent. . .

A

55.99

6.57

trace

33.15

1.60

.17

2.52

100. 00 

14. {, >4

B

56.21

6.89

.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

ft Q7

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. 00 

o 23. 036

F

55.25

6.73

34.65

9 fi4

.16

.57

100. 00

27.72

G

55. 11

6.66

32.97

3.13

.17

1.96

100. 00 

22.99

H

53.72

5

QC

32.81

4 99

.31

2.22

100. 00 

17.68

& 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. 2 The following table relates to some of the streams, except

1 They are cited in Gilbert's monograph. Bassett's analysis is exceedingly high in potassium.

2 In addition to the data given here, see analyses by J. T. Kingsbury, of City, Red Butte, Farmington, 

Emigration, Parleys, Big Cot.tonwood, 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.
THE WATERS OF CLOSED BASINS. 145

that Sevier Lake, an outlying remnant of Lake Bonneville, is included 

as a matter of convenience. The analyses are all reduced to standard 

form, with bicarbonate radicles recalculated to normal C03 . 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, Rept. No. 64, 

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. 9,1884, 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. 3,1875, p. 114. 

Sample taken in 1872.

01...................

S04 . .................

C03 ........... ........

Na.... ...............

K.... .................

Ca....................

Mg............. .......

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

(AlFe)203 .............

Salinity, parts per million........... ......

A

2.68

5.76

52.68

| 4.49

23. 69

6.86

3.84

100. 00 

185

B

32.36

8.16

21.53

1 20. 54

10.12

4.76

2.53

100. 00 

637

C

35.54

26.54

2.67

1 26. 13

7.59

1.53

100. 00 

892

D 

34.76

30.68

trace

1 23. 04

10.26

1.26

100. 00 

1,090

E

5.38

2.87

52.57

1 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 the Jordan River, has furnished material 

for a most instructive series of analyses, as follows:

Analyses of water from Utah Lake.

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. Collected 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....................................

S04 ............. ......................

C03 ..................................

Li.....................................

Na................. ...................

K... .................................

Ca......................... ............

Sr.. ..................................

Mg........... ........................

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

Salinity, parts per million .............

A

4.04

42.68

19.88

1 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

6.18

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

101381° Bull. 491 11- 10
146 THE DATA OF GEOCHEMISTRY.

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 twenty 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, the 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 of 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 exist 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 SiOr In no case }

i See analyses by R. W. Woodward, cited in Rept. U. S. Geol. Explor. 40th Par., vol. 2,1877, p. 435. 

Also an analysis by T. M. Chatard, in Bull. U. S. GeoL Survey No. 228,1904, p. 331.
THE WATERS OF CLOSED BASINS. 147

however, is the silica high enough to cause a serious error in this 

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 secure comparable results.

In the next table two groups of analyses appear. Lake Tahoe, a 

typical mountain lake of great purity, empties through the Truckee 

River, which terminates in Winnemucca and Pyramid lakes. These

waters are included in the first group. The second comprises the 

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^Paciflc Railroad.

C. Pyramid Lake, Nevada. Mean of four concordant analyses by Clarke.

D. Winnemucca Lake, Nevada. Analysis by Clarke.

E. Walker River, Nevada. Analysis 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............................

so4 ............... ............

C08 .. ........................

Na...... ......... .............

K....... .....................

Ca...........................

Mg...........................

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

(AlFe)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

C

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

1 18. 07

12.96

2.21

12.78

100.. 00 

180

F

OQ 77

21.29

17.34

1 34.83

.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

1 Except that of analysis B, which is more recent.
148 THE DATA OF GEOCHEMISTRY.

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 chloro-carbonate. 

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.

Analysis by T. M. Chatard.

Analysis by O. D. Alien, Kept. U. S. Geol. Explor. 40th Par., vol. 2,

G. Humboldt River, Nevada.

H. Humboldt Lake, Nevada. 

1877,p. 743.

I. The large Soda Lake, Ragtown, Nevada. Surface sample. Analysis by. Chatard.

J. 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 ...........................................

S04 . ................................:........

on

PO

B

r\ 4U7 . ........................................

Na............................ ................

K... ..........................................

Ca........ ....................................

Mg. ...........................................

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

Al O

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

fi 54

1.35

1.88

3.53

100. 00 

929

I

36.51

10.36

13.78

.25

36.63

2.01

99

.24

100. 00 

113, 700

J

35.38

10.50

15.89

.26

35.38

2.13

9^

.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

i See discussion by E. S. Dana, in Bull. U. S. Geol. Survey No. 12,1884. Calcite pseudomorphs, similar to thinolite and called pesudogaylussite, have been discussed by F. J. P. van Calker (Zeitschr. Kryst. 

Min., vol. 28,1897, p. 556) and C. 0. Trechmann (idem, vol. 35,1902, p. 283). The Australian glendonite 

is calcite pseudomorphous after glauberite, and sometimes forms crystals 15 to 20 inches long. See T. W. E. 

David, Rec. Geol. Survey New South Wales, vol. 8,1905, p. 162.
THE WATERS OF CLOSED BASINS. 149

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 material, 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.

In 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.
150 THE DATA OF GEOCHEMISTRY.

Analyses of water from alkaline lakes in California.

A. Mono Lake. Analysis by T. M. Chatard, Bull. U. S. Geol. Survey No. 60, p. 53, 1890. 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 others. 

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. 2?7, 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. 181,1906, p. 22. Sample taken in August, 1905. '

E. Black Lake, near Benton, Mono County. Analysis by Loew, op. cit., p. 191.

F. Tulare Lake in 1880.

G. Tulare Lake in 1889. Analyses F and G by E. W. Hilgard, Appendix to Rept. Univ. California 

Exper. Sta., 1900. This lake has an outlet during floods, but not at other times.

H. Borax Lake. Analysis by W. H. Melville, published by G. F. Becker in Mon. U. S. Geol. Survey, 

vol. 13,1888, p. 265. In addition to the substances named in the table, the original residue contained 4.5 

per cent of organic matter.

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

Br....................

I....................

S04 . .................

co3 ..... ....... .......

PO

B

r\ 4O7 . ................

N03 ..... .............

Li....................

Na.. .................

z................. ...

Rb,Cs................

Ca.............. ......

Mg... .................

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

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

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

MnA .............

As203 ................

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

4

100. 00 

339

-v C

25.67

9.95

23.51

.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

.02

.01

14

| .04

.05

100. 00 

213.700

E

7.68

13.24

37.73

39.05

2.03

.27

100. 00 

18, 500

F

17.38

16. 91

26.55

33.51

1.82

1.50

1.78

.55

100. 00 

1,360

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

1.52

.03

.35

.01 1-

100. 00 

76, 560

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.

i 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.
THE WATEES OF CLOSED BASINS. 151

NORTHERN LAKES.

The region of alkaline lakes continues northward from Nevada and 

California, and several of the waters have been analyzed. The 

analyses are given in the subjoined table.

Analyses of water from northern alkaline lakes.

A. Abert Lake, Oregon. Analysis by T. M. Chatard, Bull. U. S. Geol. Survey No. CO, 1890, p. 55. An

earlier analysis by Taylor is not in accord with this.

B. Harney Lake, Oregon. Analysis by George Steiger in the laboratory of the Survey.

C. Soap Lake, Washington. Analysis by Steiger, Bull. Ut S. Geol. Survey No. 113,1893, p. 113.

D. Soap Lake. Analysis by H. G. Knight, Ann. Kept. Washington Geol. Survey, vol. 1,1901, p. 295.

E. Moses Lake, Washington. Analysis by Knight, op. cit., p. 294.

F. 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.

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

SO4 .............. .............

co3 ..........................

PO

B4 07 ..""»-.»". .........

Na. .........................

K............................

Ca...........................

Mg...........................

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

Al O

Fea03 :.......................

Salinity, parts per million. ....

A

36.04

1.90

20.67

39.33

1.44

.62

100. 00 

39, 172

B

27.50

7.67

25.87

.92

35.78

1.91

.07

.28

100. 00 

10, 477

C

1Q OQ lo. 40

16.44

30.22

1 39. 60

.04

.42

100. 00 

28, 195

D

12.87

16.79

29.73

.49

38. 14

1.22

.29

.47

100. 00 

27, 416

E

3.88

2.87

51.56

19.86

8.41

7.25

5.06

f,u

100. 00 

2,966

F

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, Na2C03 .10H2O, of which an analysis is given. Moses 

Lake, the most dilute of all, is the only one which carries appreciable 

quantities of lime and magnesia. From the more concentrated waters 

these bases disappear almost completely. In Moses Lake they must 

be held in solution by an excess of carbonic acid, although no such 

excess is shown in the figures reported.
152 THE DATA OF GEOCHEMISTRY.

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. AVyoming Exper. Sta. No. 49,1901.

B. Big Lake.

C. Track Lake.

D. Bed 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. Old Wives or Chaplin Lake, Saskatchewan, Canada. Analysis by P. 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.

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; SiO2,12.2; R208 , 4.0 parts per million.

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

S04 .........................

CO........................... BA---- - ----- --

Na. ......................:..

K........... .................

Ca. ..........................

Mg....... .................... AI n

SiOa .........................

Salinity,0 parts per million. . . .

A

10.78

16.62

32.75

39.85

100. 00 

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 

77, 300

D

3.06

64.57

.57

29.89

.59

1.32

100. 00 

93, 100

E

4.98

61.86

1.54

30.65

trace

.97

100. 00 

27, 300

F

10.45

54.07

4.24

25.88

trace

5.36

100.00 

11, 278

a These figures for salinity have little or no significance, because the "lakes" vary from dry masses ol 

salts to solutions of differing 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. 

430,1910, p. 570.

Four of these lakes are essentially solutions of sodium sulphate, 

and resemble certain bodies of water on the Russian steppes.
THE .WATERS OF CLOSED BASIN'S. 153

CENTRAL AND SOUTH AMERICA.

For the saline waters of Central and South America the chemical 

data are very scanty. Four analyses, however, may be cited here:

Analyses of saline waters from Central and South America.

' A. Lake Chichen-Kanab ("little sea")j Yucatan. Analysis by J. L. I-Iowe and H. D. Campbell, Am. 

Jour. Sci:,4thser., 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. Lagoon of Tamentica, Chile. See F. J. San Roman, Desiertoi Cordilleras deAtacama, vol. 3, Santiago 

de Chile, 1902, p. 199. 

C. Rio Saladillo, Argentina. Analysis by Siewert, reported by A. W. Stelzner, Beitrage zur Geologio 

und Palaeontologie der argentinischen Republik, 1885. Sample taken at Puente del Monte. The river 

empties 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, 584,506,200 kilograms of salts. Stelzner also gives 

analyses by Doering of the Saladillo between Salta and Jujuy, and of Arroyo Salado in Patagonia.

D. Laguna de Epecu6n, Argentina. Analysis by M. M. Leguizamo'n, Trabajos Cuarto Cong. cient. PanAmericano, vol. 4, Santiago, 1910, p. 258.

ci...........................................

S04 . .........................................

C03 ....... ....................................

N08 ........... ................................

Na. ..........................................

K......... ....................................

Ca. ...........................................

Mg................................. ...........

Salinity, parts per million. .....................

A

8.14

58.64

11.99

.43

13.49

7.31

100. 00 

4,446

B

50.44

9.17

2.14

35.35

2.29

.01

.60

100. 00 

285, 500

C

56.74

4.82

36.40

1.63

.41

100. 00 

108, 250

D

42.96

17.19

2.13

37.72

100. 00 

285, 000

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

1 For analyses of some of these waters, the Elton, Bogdo, Indersk, and Stepanova lakes, see Roth, 

Allgemelne und chemlsche Geologle, vol. 1, p. 469. Modern and complete analyses are much to be desired; 

the old ones are unsatisfactory.
154 THE DATA OF GEOCHEMISTRY.

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 forming upon its bottom. . ^Near its margin 

gypsum crystals are formed; toward the center of the gulf sodium 

sulphate is deposited. 1 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. 2 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:

Analyses of Caspian and allied waters.

A. Caspian Sea. Mean of five analyses by C. Schmidt, Bull. Acad. St. Petersburg, vol. 24,1878, p. 177.

B. Caspian Sea. Analysis by A. Lebedintzefl, cited by W. Stahl, Natur. Wochenschr., vol. 20, 1905, 

p. 689. '

C. Karaboghaz Gulf. Analysis by Schmidt, loc. cit.

D. Karaboghaz Gulf. Analysis by Lebedintzefl, cited by Stahl, loc. cit.

E. Tinetzky Lake, a residue of concentration from the Caspian. Analysis by Schmidt, loc. cit.

F. Sea of Aral. .Analysis by Schmidt, cited from Roth, AUgem. chern. Geol., vol. 1, p. 465. Schmidt's 

analyses report bicarbonates, which are here reduced to normal salts. I have also consolidated the insignificant quantities of silica, phosphoric acid, and ferric oxide, which were determined separately.

G. Sea of Aral. Analysis by Stepanow, cited by S. Sowetow, Ann. Hydrog: und Marit. Meteorolog., 

1910, p. 658. Othef recent analyses are also mentioned, probably from the monograph by L. Berg on the 

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, Jahresber. 

Chemie, 1881, p. 1442. Analyses of the tributary rivers Sumbar and Tschandyr are also given.

01.....................

Br.. ..................

SO4 ..................

C03 ... ................

Na....... ............

K. ....................

Rb.. .................

Ca... .................

Mg... .................

Si02> P04 ,FeaOs ......

Salinity, per cent. . . . .

A*F

49 04

.05

23.99

.37

24.70

.54

.02

2.29

5.97

.03

100. 00 

1.294

# B

41 78

.05

23.78

.93

24.49

.60

2.60

5.77

100. 00 

1.267

C . C;Q QQ

.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 QQ

.13

21.25

18.46

.24

.01

.01

11.91

100. 00 

28.90

F

qc A(\

.03

30.98

.85

22.62

.54

.02

4.02

5.50

.04

100. 00 

1.084

G

OC /3O

31.27

.10

22.05

1.07

4.48

5.40

100. 00 

1.067

H

1 Q QQ

4Q nq

6.09

19.03

5.98

5.40

1.08

100. 00 

1.495

-f

Analyses C and D show that the Karaboghaz varies from time to 

time, both in composition and in concentration.

1 See S. Kusnetsofl, Zeitschr. prakt. Geologie, 1898, p. 26.

2 See N. S. Kurnakoff, Verhandl. Russ. k. min. 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, Natur. 

Wochenschr., vol. 20, 1905, p. 689. This paper is based on an official Russian report by Spiudler and 

Lebedintzefi, published in 1902. For an analysis of water from Lake Durun in Transcaspia see A. Stackmann, Jahresber. Chemie, 1887, p. 2531. "~~
THE WATERS OF CLOSED BASINS. 155

With the exception of the Atrek, 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 resembles 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,2 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.

1 Bergstrasser, in Petermann's Mittheilungen, 1858, pp. 104-105, has brought together 38 old analyses of 

salts from the lakes of Astrakhan and the mouth of the Volga.

2 Compt. Rend., vol. 62,1860, 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.
156 THE DATA OF GEOCHEMISTRY.

Analyses of water from 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.

E. Analysis by A. Stutzer and A. Reich, Chem. Zeitung, vol. 31,1907, p. 845.

L. 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 

Anderson is cited in the former edition of this book (Bulletin 330).

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

Br.........................

S04 .......................

rn

Na........................

K........................

Ca. ........................

Mg.......................

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

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

Br.........................

S04 . ......................

C08 ......................

NO........................

Na. .................;.....

K. .......................

NH4 ............ ............

Ca...... ...................

Mg.......................

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

(Al,Fe)203 .................

A

65.81

2.37

.31

11.65

1.85

4.73

13.28

trace.

100. 00 

19. 215

G

65.90

1.37

.13

11 99

3.70

trace.

5.69

12.09

trace.

100. 00 

22. 7697

B

70.25

1.55

.21

6.33

1.70

5.54

14.42

trace.

100. 00 

20. 709

H

65.22

2.08

.29

.01

1Q QQ

2.37

4.79

11.85

trace.

100. 00 

22. 2834

C

68.16

1.99

.22

10.21

1.00

1.53

16.89

trace.

100. 00 

24. 263

I

65.43

1.54

.20

11.70

3.53

trace.

5.60

11.85

.15

100.00 

20. 590

D

67.66

1.98

.22

10.20

1.62

1.51

16.81

trace.

100. 00 

24. 573

J

65.74

1.49

.33

11.60

3.40

5.02

12.42

100. 00 

21. 977

E

67.84

1.75

.22

10.00

1.79

1.68

16.72

trace.

100. 00 

25. 110

K

64.49

1.45 . 45

1 c 7K

3.24

4 nQ

10.53

100. 00 

22. 030

F

67.30

2.72

.24

5.50

1.68

6.64

15.92

trace.

100. 00 

25. 998

L

41.47

7.22

13.11

fvrtrtrt

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 arid the regions roundabout the 

Dead Sea contain many beds of rock salt and gypsum, and the neighboring Cretaceous strata are impregnated with the same substances.
THE WATERS OF CLOSED BASINS. 157

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 * and others have shown, contribute to the 

salinity of the waters. To some extent, probabry, 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 \vater 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 no iodine has been detected in it.3

OTHER RUSSIAN AND ASIATIC LAKES.

Mother liquors ha,ving 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 table 

following.

1 Bull. Soc. gfiol. France, 2d ser., vol. 23,1866, pp. 719-760.

2 Chera. News, vol. 89,1904, p. 13.

8 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. Soi., 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. 

Polytech. 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. Gmclin have only historical interest. 

A recent analysis by Mitchell (Berg- u. hiittenm. Zeitung, 1902, p. 225) is of doubtful value.
158

Analyses of Russian and Asiatic waters.

A. Elton Lake, Russia. Analysis by Erdmann, cited by Roth, Allgemeine und chemische Geologic, 

vol. 1, p. 469.

B. Red Lake, Perekop, Crimea. Analysis by Hasshagen.from Roth, op. cit.,p. 471. Roth gives analyses of sev.eral other Crimean salt lakes. Analyses of four Crimean lakes are given by A. Goebel, M61. 

chim. phys., vol. 5,1864, p. 326.

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 Urmiah, Persia. Analysis by R. T. Giinther and J. J. Manley, Proc. Roy. Soc., vol. 

65,1899, p. 312.

E. Salt lake near Shiraz, Persia. Analysis by K. Natterer, Monatsh. Chemie, vol. 1(>, 1895, p. 658.

F. Gaukharie Lake, southern Persia. Analysis by A. Heider, published by Natterer, op. cit., p. 673.

G. Koko-Nor, Tibet. Analysis by C. Schmidt, Bull. Acad. St. Petersburg, vol. 24,1878, p. 177. Bicarbonates 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 analyses of three saline lakes in Central 

Asfe, see Schmidt, idem, vol. 12,1887, p. 547.

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

Br.... ................

I.....................

S04 .................

co8 ....... ...........

Na......... .........

K......... ...........

Rb...... ............

NH4 ....... ..........

Ca......... ..........

Mg...................

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

Fe2 03 -. .-- -.------ -

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

100. 00 

2.10

D

57.33

5.06

33.98

.78

.32

2.53

100. 00 

14.85

E

58.17

.01

3.48

.23

35.51

.29

.01

.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

H

41.69

.04

16.30

6.66

28.64

.81

.04

.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 

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 recently studied by F. Ludwig. 1 The reduced analyses, 

arranged in the order of their chlorine, are as follows:

i Zeitschr. prakt. Geologic, vol. 11, 1903, p. 401. Ludwig also gives analyses of sediments and saline 

deposits from these waters.
THE WATEES OF CLOSED BASINS. 159

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 sample had a salinity 

of 25.35 per cent, and its salts contained 0.19 per cent of bromine.

C. LakeTagar.

D. Lake Beisk.

E. Bitter Lake.

F. Lake Altai.

O. Lake Biljo. This is the largest of the lakes and measures about 60 kilometers in circumference.

H. Lake JDomoshakovo.

01....................

Br......... ..........

so4 .................

co8 .... ........ ......

NO...... ............

Na..................

K... ........... ......

Ca...................

Mg...................

SiOa .. ...............

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

Fea03 ....... .........

Salinity, per cent. . .

A

48.28

14. 55

.22

3401

.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

C

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

3i. 32

1.01

.07

1.86

.01

.01

trace

100. 00 

10.47

E

20.02

43.83

1.53

31.78

1.38

.15

-1.28

.03

100. 00 

5.90

F

14.38

50.14

1.12

32.83

m

.05

.90

.03

.02

.01

100. OO1 

10. 88

G .

9.91

52.33

6.22

. 1.07

21.83

87

.43

7.28

.03

.03

100. 00

.88

H

3.71

63.62

.08

.07

30.61

59

.58

.74

trace

100. 00 

14.55

The last analysis in this table, that of Lake Domoshakovo, represents essentially a solution of sodium sulphate, with veiy 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 subjoined analyses, reduced to 

standard form, have been selected -1

i In M6m. 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.
160 THE DATA OF GEOCHEMISTRY.

Analyses of water from Siberian lakes.

A. Issyk-Eul. Mel phys. chim., St. Petersburg, vol. 11, 1882, p. 623. 

B. Iletsk salt lake, government of Orenberg. Op. cit., vol. 11,1882, p. 608. 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.

ci.......... ..................................

Br......... ....................................

80t ... .........................................

003...........................................

PO

Na..............................................

K.. ...........................................

Ca....... .....................................

Mg.... ...... ..................................

Fe. ............................................

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

S, sulphide. ...................................

A

15. 64

.03

55.94

1.26

.02

11.76

1.85

.94

12.50

.06

100. 00 

3,574

B

60.26

.47

38.86

.33

.08

100. 00 

155, 230

C

45-. 05

.11

20.23

28.01

.26

5.84

.50

100. 00 

13, 308

D :

37.96

.04

27.39

.98

23.29

.32

5.28

4.68

.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:
THE WATEES OF CLOSED BASINS. 161

Analyses of water from several European lakes.

A. Lake Laach, Germany. Analysis by G. Bischof, Lehrbuch der chemlschen und physlkalischen 

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. Illyfis or Medve Lake, near Szovata, Hungary. Analysis by B. von Lengyel, Ffildt. 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. K6zl., vol. 28, 

1889, p. 284. The data as published show discrepancies which detract from their value. Organic matter 

omitted.

E. Lake Tekir-Ghiol, Roumania. 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, Roumania. Analysis by Carnot, cited by Bujor, op. cit., p. 176. In winter this lake 

deposits crystallized sodium sulphate, mirabilite, NasSO^.lOHjO. In a memoir entitled "Apercu gfiologique sur les formations 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 Roumanian salt.

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

Br.. .........................

S04 ............... ............

co3 ...... ....................

N03 ..... :...................

PO

NB^..... ....................

Na. ..........................

K................. ..........

Ca.. .........................

Mg...... .....................

AlO

Fe.08 .... ....................

SiOa .........................

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

97

100. 00 

2,215

c

60.18

trace

.44

.04

39.02

.25

.03

"t"TQf*H

04

100. 00 

233, 747

D

19.07

22.56

19.22

.52

37.07

1.19

.20

.15

1 traces

09

100. 00 

6,276

E .

60.53

.18

.67

f"T*d/->P

trace

04 70

1.68

.28

1.84

} .03

.01

100. 00 

70, 877

F

98 9^

37 19

.27

01 nK.

OQ

2.16

} .02

.04

100. 00 

58, 038

Illyes 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.

i 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 Illyfis Lake; the salinity is 19.53 

per cent. See also F. Schafarzik, FSldt. K6zl., vol. 38,1908, p. 437.

101381° Bull. 491 11 11
THE DATA OF GEOCHEMISTRY.

With the analyses of five 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. Coheii, 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 NH4 , Fe, S, BOa, P0<, and I were also found. For the origin of the salt 

in this lake see ante, p. 139.

E. 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 ............. ......................

C03 ...... ............................

Na.............. ......................

K.............. ......................

Ca. ..................................

Mg........... ........................

(Al,Fe)a09 ... .........................

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

2.19

38.86

.09

trace

.01

t"l*Qf*A

100. 00 (?)

E

59.32

.22

1.65

undet.

35.07

.84

.13

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 the order of diminishing chlorine, only the main 

constituents being given:

Principal constituents of chloride waters.

Lake Tekir-Ghiol. ...........

Illy^s Lake. .................

Lake near Sniraz. .............

Lake Urmi. .................

Rio Saladillo. ................

Great Salt Lake (average).. . . .

Sambhar Lake. ...............

Cl,Br

60.71

60.26

60.18

59.67

59.54

58.18

57.33

56.74

55.64

55.48

53.00

S0<

0.67

.47

.44

1.29

1.65

3.48

5.06

4.82

6.52

7 fiQ

5.85

C08

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

35.43

31.70

38.95

Ca.

0.28

qq

.25

.82

.13

.46

.32

1.63

.34

1.20

Mg.

1.84

.08

.03

.83

 2.77

1.84

2.53

.41

2.22

3.72

.01
THE WATERS OF CLOSED BASINS. 163

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 ...................

C, Br, I.

68.55

66.96

64.22

S0<.

.28

6.82

C08 .

trace.

.04

Na,K.

13.04

19.90

11.27

Ca. 

4.26

2.01

.10

Mg.

13.90

11.13

17.55

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.

Tamentica Lagoon. ............

Kisil-Kul....... ..............

Lake Tagar . .. ................

Lacu Sarat. ..................

Bitter Lake. .................

Lake Altai. ...................

Old Wives Lake. ........... 1 .

Lake Domoshakovo. ...........

Cl, Br.

52.66

50.44

48.28

42.96

29.52

28.25

22.79

20.02

14.38

4.98

4.88

3.71

S0<.

10.88

9.17

14.55

17.19

34.99

37.12

42.32

43.63

50.14

61.86

62.34

63.62

CO8 .

0.22

2.13

1.55

.27

.61

1.53

1.12

1.54

.08

Na,K.

33.33

37.64

34.36

37.72

29.42

31.75

32.33

33.16

33.35

30.65

29.03

31.20

Ca.

0.12

.01

.69

.27

.39

.07

.15

.05

.68

.58

Mg.

3.01

.60

1.86

4.12

2.16

1.86

1.28

.90

.97

1.81

.74

» Monatsh. Chemie, vol. 16,1895, p. 666.
164 THE DATA OF GEOCHEMISTRY.

Some of these waters have been modified by human agency, which 

utilized them as sources of salt. They form, nevertheless, a natural 

series, hi which the alkaline radicles are nearly constant in proportion, while the chlorides and sulphates vary reciprocally.

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.

Buluktu-Kul. .................

Sea of Aral. ...................

Cl, Br.

45.16

41.96

38.00

35.43

SO*.

20. 23

23.88

27.39

30.98

C03 .

0.65

.98

.85

Na,K.

28.27

25.16

23.61

23.18

Ca.

2.44

5.28

4.02

Mg.

^ 84

5.87

4.68

5.50

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.

Principal constituents of sulphato-chloride bitterns.

Karaboghaz Gulf (average) .... 

Tinetzky Lake. ..............

Issyk-Kul. ................... J

Cl, Br.

51.86 

48.12

38.89

15.67

SO*.

16.48 

21.25

32.19

55 Q4

C03 .

0.07

.31

1 9fi

Na,K.

18.33 

18. 70

16.45

13.61

Ca.

0.28 

.01

44

Mg.

11.45 

nqi

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, which 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.

Goodenough Lake. ............

Black Lake. ..................

Palic Lake. ..................

Cl, Br.

3.88

4.99

7.64

7.68

15.68

SO*.

2.87

2.97

7.08

13.24

2.92

C08 .

51.56

50.97

41.41

37.79

41.02

Na, K.

19.86

27.05

42.82

41.08

35.75

Ca.

8.41

9.90

.02

.66

Mg.

7.25

9 77

04

3.35
THE WATERS OF CLOSED BASINS. 165

In the next group of waters carbonates and chlorides predominate, 

with sulphates in subordinate quantity.

Principal constituents of carbonate-chloride waters.

Humboldt Lake. .............

Cl, Br.

26.00

27.50

32.31

31.82

36.04

43.47

41.04

47.88

SOt.

7.67

.13

3.27

1.90

.03

5.25

3.76

.CO8 .

32.90

25.87

22.47

21.57

. 20.67

15.17

14.28

7.93

Na, K.

31.05

37.69

39.62

36.51

40.77

41.33

35.95

38.62

Ca.

3.57

.03

1.35

.25

.55

Mg.

3.62

.07

.35

1.88

2.28

.49

Borax Lake, which also contains 5.05 per cent of B407 in its saline 

residue, might well be put in a class by itself; but extreme subdivision 

is not now desirable.

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.

(ITOTOTIQ Tifilrp

Tulare Lake (average) ........

Lake Van. ...................

Lake Ruszanda. ...............

Walker Lake. .................

Soda Lake (average) ...........

Katwee salt lake. .............

Cl, Br.

10.78

13.07

25.67

23.34

18.82

27.08

19.07

23.77

35.95

36.67

S04.

16.62

16.62

9.95

12.86

18.84

11.95

22.56

21.29

10.42

12.33

C08 .

32.75

29.97

23.51

23.42

23.05

20.71

19.22

17.34

14.83

10.42

.Na, K.

39.85

39.48

40.01

39.78

36.78

38.84

38.26

34.83

36.00

40.55

Ca.

trace

0.02

.04

.89

.20

.90

Mg.

0.17

.01

.10

1.02

.57

.15

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 ...................

Cl, Br.

9.91

10.45

40.09

S0<.

52.33

54.07

. 17.84

C08 .

6.22

4.24

5.55

Na, K.

22.70

25.88

31.72

Ca.

0.43

1.77

Mg.

7.28

5.36

9 on

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
166 THE DATA OF GEOCHEMISTRY.

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 

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 hi quantitative terms, for the conditions of equilibrium 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 the 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 last 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
THE WATERS OP CLOSED BASINS. ., 167

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. 

MINEKAL 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 from the 

168
MINERAL WELLS AND'SPEINGS. 169

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 soffioni of Tuscany, helium and 

argon were found by E-. 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 

view the classification of springs is comparatively simple and foUows 

the lines laid down in the preceding chapters. Waters are classed

i Compt. Bend., vol. 151,1910, p. 1124.

* See Raylelgh and Ramsay, Zeitechr. phys. Chemie, vol. 16,1895, p. 362. Also Rayleigh, Proc. Roy. 

Soc., vol. 59,1896, p. 198.

» Gazz. chlm. 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., vol. 9,1908, p. 353, for a thorough review of the whole subject.
170 THE DATA OF GEOCHEMISTRY.

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 approximating 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. Kept. Geol. Survey Canada, vol. 15,1C02-3, p. 236 S, G. C. Hoflman gives 12 analyses of brines 

from Manitoba. A brine from a well 1,920 feet deep, at Sand Beach, Michigan, analyzed by S. P. Duffleld 

(Geol. Survey Michigan, vol. 5, pt. 2,1895, p. 82), is unusually rich In bromine.
MINERAL WELLS AND SPBINQS. 171

Analyses of chloride waters.

A. Brine from Syracuse, New York. Average of four analyses by C. A. Goessmann, published in Dana's 

System of mineralogy, 6th ed., p. 156.

B. Brine from Warsaw, New York. Analysis by F. E. Engelhardt, Bull.-New York State Mus. No. 11, 

1893, p. 38. 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 Pomeroy, Ohio. Analysis by G. W. Foulk, Bull. Ohio Geol. Survey, No. 8,1906, p. 27. 

The trace of iodine represents 0.004 gramme Nal per liter.

E. Humboldt salt well, Minnesota. Analysis by C. F. Sidener, 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. 7,1902, p. 79.

G. Artesian well, Abilene, Kansas. Analysis by E. H. S. Bailey and F. B. Porter, Univ. Kansas Geol. 

Survey, vol. 7,1902, p. 130. Well 1,260 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.

ci.......... ..........

Br............ ........

I......................

so4 ..................

PAco....................

Na.... ...............

K.....................

Ca.......... ..........

Sr.....................

Ba... .................

Mg.............. ......

Mn....................

Fe...................

FeA........... ......

Al ft

SiOa ........ ..........

Other solids...........

Salinity, per cent. ....

A

58.85

.01

2.29

.01

37.29

.03

1.28

.23

.01

100. 00 

16.84

B

59.71

1.19

38.38

.67

.05

100. 00 

26.34

C

\

fil 97

. .52

32.76

4.25

1.20

100. 00 

20.24

D

61.59

.13

trace .

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

.66

2.71

1.80

.02

.07

.36

100. 00 

5.72

F

59.60

1.33

38.38

.55

.ii

.03

100. 00 

29.31

G

61.65

29

.07

3L 57

i"l"Qf»£k

4.85

1.52

trace .

.05

trace .

100. 00 

17.89

H

59 96

37.20

.94

.29

.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.

The following analyses also represent the salts from chloride waters 

in which sodium is largely the predominant base.
THE DATA OF GEOCHEMISTRY.

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. 32,1886, p. 133. This water contains considerable quantities of free HjS and COs.

B. Upper Blue Lick Spring, Kentucky. Analysis by J. F. Judge and A. Fennel, cited by Peale, op. cit., 

p. 111. Also rich in HjS and COj. I represent here by X an indeterminate mixture of CagPjOg, AlaOs, and 

Fej03 . 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, pp. cit., p. 97.

E. Utah Hot Springs, 8 miles north of Ogden, Utah. Temperature 55° C. Analysis by F. W. Clarke, 

Bull. U. S. Geol. Survey No. 9,1884, p. 30.

F. Spring at Pahua, 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 disulphide.

In analyses D and F the bicarbonates of the original statement have been reduced to normal salts.

CL. ........ ..................

Br.... .......................

I, free........................

S04 . ........................

C08 ...... ....................

PO

Na ..........................

K....... .....................

Li. ..........................

Ca.... .......................

Mg......... ..................

Al.................. ..........

AlaO,....., ..................

Fe ..........................

FeaO......... .................

SiO...... :...................

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

.94

.61

30.38

3.76

4.90

.40

.02

90

100. 00 

23, 309

F

60.78

trace

.04

.11

.15

.17

.05

34.81

.02

3.14

.60

.01

+1*O f*Q

19

100. 00 

21, 060
MINERAL WELLS AND SPRINGS. 173

Analyses of chloride waters J Continued.

G. Water of Salsomaggiore, Italy. Analysis by R. Nasini and F. Anderlini, Gazz. chlm. ital., vol. 30, 

i, 1900, p. 305. Contains in 1,000 grams 0.00223 gram Mn and 0.00792 gram B4 0i. These are less than 0.01 per 

cent of the total solids.

H. The Marienquelle, Bavaria. Analysis by A. Lipp, Ber. Deutsch. chem. Gesell., vo~l: 30,1897, p. 309. 

Contains also much free COj.

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 POt, and 0.00016 

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 here given.

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. Bothamloy, Jour. Chern. Soc., vol. 89, 1881, p. 

502. The same author, in vol. 63, 1883, p. 685, gives analyses of waters from Askern, Yorkshire.

01............................

Br........ ...................

I.......... ...................

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

S04 .........................

S.............................

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

PO

As04 ....... ..................

B

/-\ 4U7 ........................

BCy........ .................

Na ..........................

K............................

Li...........................

NH4 .........................

Ca................. :.........

Sr. ........ ...................

Ba...........................

Mg...........................

Mn...........................

Fe".................... ......

FeA-. .......................

Cu...........................

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

Salinity, parts per million. ....

G

61.09

.15

.03

.18

trace

34. 04

.07

.12

3.21

.24

.82

.03

.01

.01

100. 00 

159, 000

H

52.72

.42

.54

7.66

trace

trace

33.08

trace

trace

4.15

1.34

.09

trace

100. 00 

2,970

I

56. 58-

.04

trace

.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

1.10

.34

.08

.29

.14

.03

100. 00 

30, 150

K

58.81

.19

.01

trace

.23

2.12

33.61

.48

.01

.03

2.65

.42

1.37

.07

100. 00 

14, 800

L

60.83

.07

trace

.02

1.23

23.45

.35

.03

7.28

.07

.76

3.12

.10

2.39

.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

1 For the common occurrence of Sr, Ba, Mn, As, etc., in mineral springs see J. C. Gil, Rev. Acad. ci. 

Madrid, vol. 8, 1909, p. 131. On selenium in mineral waters see F. Taboury, Bull. Soc. chim., 4th ser., 

vol. 5,1909, p. 865.
174 THE DATA OF GEOCHEMISTRY.

can be paid here. The last analysis given, that of the Chloride of 

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.

P. Water from the Silver Islet mine, Lake Superior. Analysis by F. D. Adams, Ann. Kept. Geol. 

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 

aboratory of the United States Geological Survey.

F. Water from boring on Kanab Creek, near Port Haney, British Columbia. Analysis by F. G. Wait, 

Ann. Kept. Geol. 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 A1C13 and part as A1303 .

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

Br....................

I.....................

S04 ....................

rr»

PO

Na.....................

K............. .......

Li....................

NH4 ..................

Ca....................

Sr.... ................

Mg.. .................

Al....................

Ali08 .................

Fe.............. ......

FeA. .. ............

Mn, Co...............:

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

Salinity, parts per milA

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

13.68

5.22

trace

100. 00 

46, 300

C

64.45

8.71

1.92

20.67

4.25

100. 00 

21, 660

D

61.57

.13

.48

18.33

.67

17.46

1.21

trace

.15

100. 00 

36, 000

E

63.55

.01

.01

5.63

none

30.78

.61

.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

16.65

.93

18.34

fl4

.43

.54

 f"l"0 f»O

1.78

100. 00 

7,813

1 Compt. Rend., vol. 103,1886, p. 1205.

2 See also the analysis of brine from a well at Alma, Michigan, by C. F. Chandler and C. E. Pellew, Geol. 

Survey Michigan, vol. 5, pt. 2,1894, p. 46. Also one of water from the Freda well, Keweenaw Point, Michigan, by G. A. K6nig, 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. List., vol. 12,1909, p. 114, and Proc. Lake Superior 

Min. Inst., 1908, p. 63.
MINEKAL WELLS AND SPRINGS. 175

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. Peale in Bull.' 

U. S. Geol. Survey No. 32,1886, 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.

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 COs. The PO* 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 hi Mon. U. 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.are 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 Stanlslawaquelle, near Karlsdorf, Galicia. Analysis by Von Dunin-Wasowlcz and J. Horowitz, 

Chem. Centralbl., 1899, pt. 2, p. 491. Bicarbonates reduced to normal salts. The NOs amounts to 0.02 

part per million. One kilogram of this water contains 2.157232 grams of free COs and 0.10665 gram of organic 

matter.

01........ ............

Br. ...... .............

I.....................

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

S04 ...................

S. ....................

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

NO

PO

B

r\ t(J7 ......... .........

Na...................

K... .................

Li.....................

G&....... .............

Sr... .................

Ba. ..'.................

Mg..............:....

Mn...................

Fe

FeA . 

Al....................

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

As.................... » 

Sb....................

Hg...................

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

Salinity, parts per million................. .

A

42.00

1.13

.02

trace

.08

18.59

trace

trace

27.62

.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

.02

.17

100. 00 

15, 238

C

41.95

.37

.02

trace

.04

18.66

trace

trace

28.84

1.83

.07

5.04

trace

.06

2.95

.07

.03

.07

100. 00 

20, 315

D

48.03

.05

.04

14.93

.49

.09

29.84

.41

trace

3.75

2.19

.02

.06

.16

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

11. 41

100. 00 

2,850

F

38.01

trace

trace

20.89

4.22

32.80

.72

trace

1.85

1.37

trace

trace

..

.14

100. 00 

8,870

G

34.60

} .02

.82

19.96

trace

37.29

.53

.01

3.64

1.44

.82

.01

.17

fiQ

100. 00 

7,639
176 THE DATA OF GEOCHEMISTRY.

SULPHATE WATERS.

The sulphate waters, or the waters in which SO4 is the principal 

negative ion, fall, like the chloride waters, into several groups, which 

shade one into another by 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 Abilene, Kansas, 130 feet deep. Analysis by E. H. S. Bailey, 

Univ. Geol. Survey Kansas, vol. 7,1902, p. 166. The "traces" refer to 4 parts N03 and 3.2 parts Fe per 

million of water.

B. Spring near Denver, Colorado. Analysis by L. G. Eakins, Bull. U. S. Geol. Survey No. 60, 1890, 

p. 174. Contains 210 parts of free COj 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 COS.

E. Water from C.ruzy, Hfirault, France. Analysis published by Braconnier, Annales des 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 epsomite.

F. St. Lorenzquelle, Leuk, Switzerland. Analysis by G. Lunge and R. E. Schmidt, Zeitschr. anal. 

Chemie, vol. 25,1886, p. 309. Contains 0.06 part Li, 0.05 part NH4 ,0.05 part Fe, and 0.11 part Mn per million in each case less than 0.01 per cent of the total solids.

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

SO4 ..................... ......

rn

TVJf)

POru4 ..................... ......

As...........................

Na . .....

K...................... ......

Li...........................

NH

Ca. ..........................

Sr............................

Ba..... ......................

Mg....... ....... .............

Mn............. ..............

Fe"......... .................

FeaOg........ ................

Al O

Al....................... ......

Cu...........................

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

Salinity, parts per million. ....

A

0.48

66.28

.60

30.46

1.08

.67

.41

.02

100. 00 

74, 733

B

2.62

72.56

11.23

.22

.53

12.79

trace

.05

100. 00 

60,584

C

6.56

57.42

6.48

.02

13.51

.48

.01

8.33

7.03

trace

trace

.16

100. 00 

5,518

D

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

.01

.07

100. 00 

101, 000

F

0.34

65.86

3.74

trace

trace

1.50

.30

trace

23.55

.05

3.07

\ «

.03

trace

1.55

100. 00 

1,948
MINEEAL WELLS AND SPRINGS. 177

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 HaSO< 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 Budos, Transylvania. Other papers in the volume give a nurnber 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. Alum well.Versailles, Missouri. Analysis by P. Schweitzer, Geol. Survey Missouri, vol. 3,1892,p. 131.

I. Water from Eoncegno, 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, 4 J miles west of Joplin, Missouri. Analysis by W. F. Hillebrand, Bull. U. S. 

Geol. Survey No. 113,1893, p. 49. Total COs, free and combined, 120.5 parts per million. A trace of lead is 

also reported.

so4 ............. ......................

r\r\

PO

HSABO4 ... ............................

As02 .................................

N«

K............. .......................

Li......................................

Ca. ..................................

Mg.... ...............................

Mn. ..................................

Fe".. .................................

Fe'"..................................

Al

Co...................................

Ni...................................

Cd.......... .........................

Zn...................................

Cu...................................

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

G

0.48

65.33

trace

.4i

.31

.32

3.00

1.48

.12

24.98

1.21

QO

.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 03

.23

1 Q3

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

13.09

3.05

trace

.01

1.19

100. 00 

7,683

K

0.48

52.76

8 Art

.67

4fi

11.32

.71

.42

. .11

08

.10

22.31

.04

2.54

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, 

101381° Bull. 491 11 12
178 THE DATA OF GEOCHEMISTRY.

Analyses ofjnine waters.

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, 4.6 Co, 6.8 K, and 1.5 P0<.

01.............:............:..........................

S04 ... .................................................

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

i*i*Q r*A

14.38

1.36

.08

6.49

10.74

trace

no

90

.86

100.00 

4,232

B

0.03

63.26

KA

4*1*0 r*c*

none

q EC

.26

09

4.88

24.80

.04

OQ

1.46

1.11

100.00 

9,754

C

0.01

fin 9Q

.04

\ VO PO

.26

10

.01

04

trace

trace

.37

38.72

.07

.06

100. 00 

117, 850

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 sulphate-chloride waters.

A. King's mineral spring, near Dallas. Twenty-sixth Ann. Kept. Indiana Dept. Geology, 1901, p. 32. 

Contains traces of Al, Fe, Ba, Sr, Li, Mn, Ni, Zn, Br, P04, and B«0;. 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, POt , and B^O;. 

Also 32.5 parts of HjS per million of water.

01..............................................................

S04 . ..........................................................

rn

Na. ...........................................................

K.. ............................................................

Ca.. ............. ..............................................

Mg.. ....... ....................................................

Si02 .. ........:................................................

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

5.21

.17

100. 00 

4,417
MINERAL, WELLS AND SPRINGS. 179 

CARBONATE 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, 

CaCOg and MgC03 are deposited, while the ferrous bicarbonate is 

broken up, and insoluble Fe2O3 , 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 reasonably 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 Some interesting carbonate waters from Colorado are described by W. P. Headden in Am. Jour. Sci., 

4th ser., vol. 27,1909, p. 305.
180 THE DATA OF GEOCHEMISTRY.

Analyses of carbonate waters.

A. McClelland well, Cass County, Missouri. Analysis by P. Schweitzer, Geol. Survey Missouri, vol. 3,

1892. p. 181.

B. Artesian water, La Junta, Colorado. Well 386 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, NO3 , Ba, NIL., 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 J. Bouquet, Annales chim. phys., 3d ser., vol. 42, 

1854, p. 304. Analyses of other Vichy waters and their sediments are given in this memoir.o

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. 61,'1890, p. 123. This 

water 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. Rept. 

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.

I. Parts per million of water.

Cl ................... I....................

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

S04 ..................

s....................

on

HC03 ........... ......

PO

As04 ............ ......

 R f\ OMj... ..............

N&..... ..............

K. ..................

Li....................

Ca.......... ..........

Sr...................

Me

Mn. .................

Fe...................

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

A1A.................

SiOa .. ................

A

94

,

88

1

1,287

581

4

2

12

2,069

B

66.9

71.1

791.5

668.7

6.4

4.4

2.5

2.4

3.4

51.0

1,668.3

c

231.4

5.2

151.0

1,095.9

.2

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

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

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

trace

5.24

1.76

i"TQl^A

66.27

18.85

.05

46. 57

qn

69.36

621. 69

a 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-rArchambault 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 Silvaand 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 to 0.004 gram per liter. In one Vichy water he found 0.018 gram, his maximum. This is 18 

parts per million.
MINERAL WELLS AND SPRINGS. 181

Analyses of carbonate waters Continued. 

II. Percentage of total solids, all carbonates normal.

Cl. .................. I....................

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

S04 . .................

S.............. ......

C03 ............. ......

P04 .. ................

As04 ........... .......

BA-- ---------------

Na...................

K. ..................

Li....................

Ca..... ...............

Sr. ..................

Mg. .................

Mn ..................

Fe...................

FeA---- -------------

ALA.......... ........

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

.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

£

3.84

.98

52.09

present

38.39

.64

trace

2.04

1 i, 99uu

.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

1.31

67.56

trace

1.13

.26

2.54

25.03

.21

.14

1.79

100. 00

H

0.28

1.68

38.72

.14

1.36

.46

17.18

trace

4.89

.01

17.24

.07

17.97

100. 00

WATERS OF MIXED TYPE.

The following analyses, which are all reduced to the normal standard, represent waters of mixed types, 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.
182 THE DATA OF GEOCHEMISTBY.

Analyses of waters of mixed types.

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, 

892, 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. Whitfleld, Bull. 

U. S. Geol. Survey No. 47,1888, p. 36. Free COa, 354 parts per million.

E. Orange Spring, Yellowstone National Park. Analysis by Gooch and Whitfleld, op. cit., p. 38. Free 

COs, 92 parts per million.

F. KQnigsquelle, Bad Elster, Saxony. Analysis by R. Flechslg, 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 COa is also present.

G. The Sprudel, Carlsbad, Bohemia. Analysis by F. Ragsky, cited by Roth, Allgeineine und chemische 

Geologie, vol. 1, p. 569. Contains 0.7604 gram free and half-combined COa, per kilogram. Also traces of Br. 

I,Li,B, Rb,andCs.

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.

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

Br....... ...........

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

S04 . .................

COa...................

PO

As04 ................

B

/v 407 ...................

Na...................

K. ..................

Li....................

NH4 .. ................

Ca....................

Sr. ..................

Mg ..................

Mn ..................

Fe...................

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

Al ...................

A1 O

SiO2 ..................

Salinity, parts per million............. ....

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

.35

100. 00 

3,008

D

10.09

30.34

21.65

.26

1.46

7.50

2.95

.13

.03

17.76

4.21

' .54

2.98

100. 00 

1,732

.E

10.07

trace

32.80

20.76

7.65

3.78

.10

17.50

4.09

.is

3.12

100. 00 

1,612

F

20.36

31.47

10.96

32.51

.45

.23

1.40

.44

.19

.59

1.40

100. 00 

4,991

G

11.52

.03

31.19

19.15

.01

32.49

1.35

2.23

-.01

.65

.01

.02

4-|*Q/>rt

1.34

100. 00 

5,431

H

27.34

30.58

7.13

8.96

4.25

5.89

15.85

100. 00 

225

SILICEOUS WATERS.

Waters characterized by a large relative proportion of silica are 

common, and a number of examples were noted among river waters, 

Uruguay River forming the 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

1 For example, the Opal Spring, in the Yellowstone National Park, carries 0.7620 gram of silica per kilogram of water.
WELLS AND SPRINGS.

usually reported as SiO^; 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 SiO3 , the dried residue being 

supposed to contain the sodium salt Na2Si03 ; but this is hardly more 

than a convenient device for evading a recognized uncertainty. In 

solution, according to L. Kahlenberg and A. T. Lincoln, 1 sodium 

metasilicate is hydrolyzed into colloidal silica and sodium hydroxide; 

and this conclusion was also reached by F. Kohlrausch 2 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 two waters just mentioned are as follows. Both are rather 

dilute 

' Jour. Physical Chem., vol. 2,1898, p. 77. s Zeitschr. physikal. Chemie, vol. 12,1893, p. 773.
184 THE DATA OP GEOCHEMISTRY.

Analyses of silicic waters not of volcanic origin.

A. Big Iron Spring, Hot Springs of Arkansas. Analysis by J. K. Haywood, Kept, to U..S. Dept. Interior, 

1902. This is a typical water, selected from among the 46 springs which were analyzed. All the hot springs 

in this group are very much alike. Haywood reports his carbonates wholly as bicarbonates, and his figures 

are here restated in normal form that is, HCOs 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. Rend., vol. 

104,1887, p. 1178. Temperature 79.4° C. In this water, which might also be classed as a sulphur water, 

the radicle SaOa represents the presence of thiosulphates, produced by the partial oxidation of sulphides. 

Thiosulphates have also been reported in other waters, and several examples from Indiana are cited in 

Twenty-sixth Ann. Kept. Indiana Dept. Geology, 1901, pp. 76,81,86.

01.............................................................. 1.27 4.38

Br, I.......................................................... traces

S04 ............................................................. 3.93 7.28

S203 .-................................................................. 4.81

S............................................................... ........ 3.38

CO............................................................. 41.47 12.14

N03 ........................................................... .23

P04 ........................................................... .03

B02 ............................................................ .64

Na............................................................ 2.38 26.09

K.............................................................. .80 2.00

Li............................................................. trace

NH4 ........................................................... .03

Ca............................................................. 23.54 1.01

Ba, Sr......................................................... traces

Mg............................................................. 2.56 trace

Mn............................................................. .17

Fe,Al.......................................................... .10

Si02 ........................................................... 22.85 38.91

	100.00 100.00 

Salinity, parts per million....................................... ° 199 244

a 284.8 in the original, where bicarbonates are included. In that statement HCOs forms 59.02 per cent 

of the total solids. This water might be equally well classed with the carbonate waters.

For.geyser waters and waters of similar character the data are

abundant and only a few examples need be utilized here.
MINEBAL WELLS AND SPRINGS. 185

Analyses of geyser waters.

C. Coral Spring, Norris Basin, Yellowstone 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, Yellowstone National Park. Analyses C to G by F. A. Gooch and 

J. E. Whitfleld, Bull. U. S. Geol. 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. Chem. Pharm., vol. 62,1847, p. 49.

I. Te Tarata, Roturua, New Zealand. The water which formed the white terrace of Rotomahana. A 

large excesssof silica over bases, represented as SiOs.

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 this memoir. J. S. Maclaurin, in Thirty-ninth Ann. Rept. Colonial Laboratory, Mines Dept, New 

Zealand, gives 23 analyses of mineral springs in New Zealand. Several of them are very high in silica. 

See also the Forty-second Report. For early analyses of Yellowstone waters see H. Leffman, Am. Jour. 

Sci., 3d ser., vol. 25, pp. 104, 351.

ci.. ....................

Br....................

S04 ..................

s......................

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

PO

AaO

TO BA-- f\

--- ------------

Na...................

K.. ...................

Li....................

NH4 ....... ...........

Ca............. .......

Mg.. ........... .......

Mn....................

Fe....... ............

Fe203 --- -- - ----- 

Ala08 ....... ..........

Al.....................

Si08 ....... ...........

SiO........ ...........

Salinity, parts per milC

36.61

1.84

.15

.08

2.24

21.44

4.45

.22.

.02

.39

.08

trace

.76

31.72

100. 00 

1,830

D

14. 93

trace

28.65

.29

2.38

15.65

4.89

trace

.13

1.42

none

none

.33

31. 33

100. 00 

808

E

trace

29.22

12.15

2.05

trace

trace

1 5.80

50.78

100. 00 

473

F

31.64

.25

1.30

8.78

.24

1.19

26.42

1.93

.40

trace

.11

.04

trace

trace

.12

27.58

100. 00 

1,388

Go

20.91

trace

1.31

25.01

.29

1.34

31.34

2.43

.15

.17

.17

.13

.17

16.58

100. 00 

1,336

H

13.52

9.01

.32

10.16

19.71

1.88

.28

.08

45. 04

100. 00 

1, 131

I

26.82

3.60

i"TQf*A

33.94

1.01

trace

.38

.09

.20

.01

33.95

100. 00 

2,064

J

37.52

4 Qfi

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 B407 , corresponding to about 11.5 per cent 

of anhydrous borax. 1 Nitrates are usually regarded as evidence of

i Boric acid in natural waters has been discussed by L. Dieulafaitin Compt. Rend., vol. 93,1881, p. 224; 

vol. 94,1882, p. 1352; and vol. 100,1885, pp. 1017,1240. According to L. Kahlenberg and O. Schreiner (Zeitschr. physikal. Chemie, vol. 20,1896, p. 547), the group BiCh is not the true ion of the borates. It is a convenient expression, however, for the negative radicle of borax.
186 THE DATA OF GEOCHEMISTRY.

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.1 The following analyses probably represent extreme examples 

of phosphates, borates, and nitrates in natural waters:

Analyses of phosphate, borate, and nitrate waters.

A. Hot spring from sulphur bank on 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. 188), 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 HzS, and a considerable amount of COj 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. «

01............................ I.............................

S04 . ..........................

C08 .......... ................

N03 ................... ........

B407 ...... ...........:........

P04 ...........................

Na............................

K................ ............

Li...........................

NH4 .......... .................

Ca........... ................

Mg......... ..................

Mn........... ................

Fe".......... ................

Fe'"... .......................

AL03 . ............;..........

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

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 

65,343

B

13.57

.32

22.38

27.98

QQ Q7

.48

.05

.41

.11

.73

100.00 

5,096

C

14.39

10.06

4.73

40.09

OR 40

.84

.02

.44

.03

.01

.90

100.00 

4,632

D

5.11

7.74

19.46

6.33

22.41

Q 00

trace

30.38

1.21

4.04

100.00 

490

E

5.45

27. 87

2.58

36.09

0 KO

.68

trace

15.93

5.17

.06

.06

2.58

100.00 

1,163

F

ift 44

14.04

12.78

24.62

10 CC

6.67

8.70

2.70

1.39

100.00 

3,455

o The mineral water of Cherrydale, Virginia, is also reported to be rich in nitrates. See analysis by J. K. 

Hay wood and B. H. Smith, of a commercial bottled sample, In Bull. Bur. Chemistry No. 91, U. S. Dept. 

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.

6 Reckoned with normal carbonates. With bicarbonates the salinity becomes 6,556 parts per million.

i See W. W. Skinner, Bull. Univ. Arizona Agr. Exper. Sta. No. 46,1903.
MINEKAL WE:LLS AND SPEINGS. 187

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 add waters from sedimentary rocks.

A. The Tuscarora'sour spring, 9 miles south'of Brantford, Canada. Analysis by T. Sterry Hunt, Qeol. 

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 SO8 ; it is here recalculated into 

H2SO«.

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. Rockbridge Alum Spring, Virginia. Analysis by M. B. Hardin, 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.

HaS04 , free.....................................

HN08> free.. ...................................

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

S04 , combined. ...............................

PO

Na ....... . . .... ....... .

K........ ......................... A..........

LL......... ..................................

Ca... .........................................

Mg.. ..........................................

Fe"..................... ......................

Fe"'...... ....... ..........;..... ..............

Mn.................... ........................

Ni............................................

Co............................................

Zn............................................

Cu.......................... .................

Al.............. ...............................

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

Total inorganic impurity, parts per million. .....

A

69.62

22.11

trace

.26

.44

3.70

.50

2.17

1.20

100.00 

6,161

B

47.87

.43

36.28

.87

.71

6.39

2.06

3.06

i.66

1.33

100.00 

a 5, 136

C

5.82

.18

75.14

1.19

2.24

12.55

2.88

100.00 

3,715

D

9.37

trace

.32

68.21

.22

.11

.01

.38

1.11

1.19

.69

.07

.05

.08

11.08

7.11

100.00 

464

a 4,685 when the free acid is reckoned as BOj.
188 THE DATA OP GEOCHEMISTRY.

Among volcanic waters acidity is much more common, and manyexamples of it are known. The following analyses are among the 

most typical, and are stated in the normal percentage form:

Analyses of add waters of volcanic origin.

A. Devil's Inkpot, Yellowstone National Park. Analysis by F. A. Gooch and J. E. Whitfleld, Bull. 

U. S. Geol. Survey No. 47,1888, p. 80. Acidity slight. This water is unique on account of its high proportion 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 CO3 and 5 parts of HsS per million. 

As an ammoniacal water this may be compared with the borate water from Clear Lake, California, previously 

cited.

B. Rio Vinagre,Colombia. Analysis byJ. B. Boussingault, Annaleschim. phys.,5thser., vol. 2,1874, 

p. 80. Free S03 recalculated into HsSO*. Boussingault also gives analyses of several saline waters from 

the same region. On p. 81 he estimates that Rio Vinagre at Purace carries,, each day, 46,873 kilograms of 

HsSO< and 42,150 kilograms of HC1. These figures correspond to 17,000 and 15,000 metric tons per annum.

C. Hot Spring, Paramo de Ruiz, Colombia. Analysis by H. Lewy, cited by Boussingault, op. cit., p. 91. 

Free S03 recalculated into HsSO^

D. Solfatara at Pozzuoli, Italy. Analysis by S. De Luca, Compt. Rend., vol. 70,1870, p. 408.

E. Brook Sungi Pait, from crater of Idjfin volcano, Java. Analysis by F. A. Fliickiger, Jahresber. 

Chemie, 1862. p. 820. Acid waters are not uncommon in Java.

HC1, free.............................

H2S04 , free. ...........................

H3B03 ... .............................

CL. ..................................

S04 ................. ..................

PO

BA-- ..............................

Na............. .......................

K................... .................

Li...................................

NH4 .................................

Ca. ..................................

Mg..... ..............................

Mn......... ........................

Fe". .................................

Fe'".................................

Al......... ...........................

Ae...................................

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

' A

0.18

1.29

2.73

67.66

.73

.24

.01

22.85

1.18

.36

trace

.10

2.67

100. 00 

3,365

B

35.92

1.89

4.75

43.97

3.08

2.45

7.14

.80

100. 00 

a 2, 969

C

5.50

44.17

4.96

31.71

3.22

1.21

2.31

1.53

3.18

2.21

100. 00 

b 8, 296

D

16.62

.34

55.08

.57

.58

2.91

.55

trace

3.47

7.16

12.72

100. 00 

c2,477

E

43.96

14.95

26.96

1.32

.39

2.05

.94

4.66

4.44

.33

100. 00 

18, 060

" 2,959 with free SO8 instead of HZSO<. 

K 7,023 with free S03 instead of HjSO«.

e 2,401 with free SO8 instead of HsSO«.
MINERAL WEI/LS AND SPRINGS. 189

Analyses of acid waters of volcanic origin Continued.

F. Hot Lake, White Island, Bay of Plenty, New Zealand. Analysis by C. Du Ponteil, Ann. Chem. 

Phann., vol. 96,1855, p. 193. Practically a 10 per cent solution of hydrochloric acid.

G. Probably the same water as that of F. Analysis by W. Skey, Trans. Now Zealand Inst., vol. 10, 

1877, p. 423. In a later analysis by J. S. Maclaurin (Prop. Chem. Soc., vol. 27,1911, p. 10), the presence of 

pentathionic acid is reported.

H. Cameron's Bath, Rotorua geyser district, New Zealand. Analysis by Skey, loc.cit. Contains 6 parts 

per million of HjS.

I. Yellow lake or hot pool, crater of Taal volcano, Luzon, Philippine Islands.

J. Green lake or pool, crater of Taal volcano. Analyses I and J by J. Centeno, Estudio geol<5gico del 

volcan de Taal, Madrid, 1885. Obscurely stated. Recalculated on the assumption that "fosfato s6dico" 

means NasPO*, and that sulphuric acid means HaSO* and not S08 . The free acid, however, should probably be all hydrochloric, with no sulphuric at all. In tins' 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 thesa Taal waters, see R. F. Bacon, Pnilippine Jour. Sci., vol. 1,1906, p. 433; vol. 2,1907, p. 115, 

Unfortunately, these analyses, which corroborate Centeno's, are stated in such form that I can not reduce 

them to the uniform standards.

For analyses of the California geysers, see Winslow Anderson, Mineral springs and health resorts of 

California, San Francisco, 1892, pp. 136-153. Some of these waters are strongly acid.

HC1, free.............................

HaS04> free. .........................

H3BO3 ......... ....................... ci...................... ..............

so4 ..~. ..............................

PO

BA......... .................. .......

Na..................... ...............

K................. ...................

Ca...................... .............

Mg................. ..................

Mn.. .................................

Fe" .................................

Fe'"..... ............................

Al.. ..................................

As...................................

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

F

65.42

11.69

10.64

1.91

trace

.75

.59

2.30

.34

trace

5.98

.35

.03

100. 00 

158, 051

G

69.99

9.96

11.34

1.56

.90

.50

.09

2.86

2.62

.18

100. 00 

194, 830

H

5.60

59.11

20.21

8.35

.32

.47

.22

<

.33

 trace

5.39

100. 00 

1,862

I

5.87

47.26

9.50

1.26

24.14

1.38

.56

.98

.78

5.35

.55

2.37

100.00 

26, 989

J

13.04

2.48

44.52

6.40

.73

20.75

3.03

.22

1.02

1.03

5.55

1.23

100. 00 

60, 023

Still another acid water, from the crater of Popocatepetl, was 

partially analyzed by J. Lefort. 1 It contained 11.009 grams of hydrochloric acid and 3.643 of sulphuric acid in 1,000 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

«Compt. Rend., vol. 56,1863, p. 909. 3 Annaleschim. phys., 5th sen, vol. 2,1874, p. 76.
190 THE DATA OF GEOCHEMISTRY.

may also be formed by volcanic heat, sulphur, either free or derived 

from sulphides, first burning to S02 , which afterward, in presence 

of moisture, oxidizes to H2SO4 . It is also to be borne in 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.1

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 in previous chapters; but 

the greater 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 aa 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. Sulphate-carbonate waters. S04 and C03 both abundant.

VI. Chloro-carbonate waters. Cl and CO3 both abundant.

VII. Triple waters, containing chlorides, sulphates, and carbonates in equally

notable amounts. 

VIII. Siliceous waters. Rich in Si02 .

IX. 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 suphate

i In Bull. U. S. Geol. Survey No. 315,1907, p. 489, W. T. Leecltes an analysis by W. M. Barrof a strongly 

acid water from the sulphur beds of Cove Creek, Utah. It contains 4,523 parts per million of free HSSO«
MINERAL WELLS ANT> SPRINGS. 191

water of the Devil's Inkpot. Many waters are obviously intermediate in character, like the brines containing both calcium and 

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 i 

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.

i Annales chim. phys., 4th ser., vol. 16, 1869, p. 202. See also a recent physlcochemical discussion by 

F. Auerbach, Zeitschr. physikal. Chemle, vol. 49,1904, p. 217,
192 THE 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:

CaH2C206 = CaC03 + H2O + CO2 ;

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, Yellowstone National Park. Analysis by 

F. A. Gooch, Bull. U. S. Geol. Survey No. 228,1904, p. 323.

B. Travertine, near Pulsating Geyser, Mammoth Hot Springs. Analysis by J. E. Whitfleld, 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. Kept. U. S. Geol. Survey, 1889, p. 619.

C. Lithoid tufa, Lahontan basin, Nevada. One of three analyses by 0. 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, Rept. U. S. Geol. Explor. 40th Par., vol. 1,1878, p. 502.

Insoluble. .....................................

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

Al O

YQ£>Z ....... ..................................

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

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

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

Na20.........................................

Li20.. ........................................

NaCl.........................................

01.................... .........................

S03 .. ........................................

C02 ................... ........................

P O

S2r.""v.-.":::::::::::::::::::::::::::::::::

A

0.09 } »

55. 37

.35

.04

.10

.44

43. H

.32

.17

100. 10

B

0.05 \ - 11

52.46

.90 :7i

.33

1.45

1.82

40.88

1.02

.30

100.03

C

1.70

1 25

f . 6O

50. 48

2.88

trace

trace

41.85

.30

2.07

99.53

D

8 4ft

1 31

tl*Gf*(*

46.38

3.54

.22

.48

ti*or»A

38.20

trace

1.71

100. 24
MINERAL WELLS AND SPRINGS. 193

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 As205 . 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.

OCHEROTJS 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. Sometines 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 Allgem. chem. Geol., vol. 1, p. 539.

s Annales chim. phys., 3d ser., vol. 42,1854, p. 332. For later analyses of Vichy deposits, see C. Girard 

and F. Bordas, Compt. Rend., vol. 132,1901, p. 1423.

s Ann. Chem. Pharm., vol. 73,1850, p. 217.

4 Proc. 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 COs, can 

hold barium in solution, notwithstanding the presence of sulphates. R. Delkeskamp, in Notizbl. Ver. 

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, Jahresber. Chemie, 1899, p. 635, on barium in artesian 

waters of Derbyshire.

6 Zeitschr. Kryst. Min., vol. 47,1909, p. 104.

« Oesterr. Zeitschr. Berg- u. Pluttenwesen, vol. 55,1907, p. 596.

7 Zeitschr. Kryst. Min., vol. 43,1910, p. 45.

8 See W. Lindgren, Econ. Geology, vol. 5,1910, p. 22.

9 Allgemelne und chemische Geologic, vol. 1, pp. 599, 600.

101381° Bull. 491 11 13
194 THE DATA OF GEOCHEMISTRY.

Analyses of ocherous deposits.

A. Deposit from Driburg, Germany. Analysis by F. J. H. Ludwig, Jahresber. Chemie, 1847-48,p. 1012.

B. Deposit from Nauheim, Germany. Analysis by Ewald, Jahresber. Chemie, 1847-48, p. 1012.

C. Deposit from Enclos des Ce'lestins, 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. 

Whitfleld 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.

FeA - 

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

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

Ga.C03 .... ....................................

MgC03 .. ......................................

NaCl, etc..............................'.-.......

so8 .. ........................................

P O v

AH O

As205 . .......................................

Soluble Si02 ... ................................

H20............ ...............................

Sand. ........................................

C02 and loss. . .................................

A

57. 303

6.683

.543

.063

23. 333

.542

5.388

6.145

100. 000

B

49.86

.40

20.81

2.59

2.81

23.53

100. 00

C

47.40

trace

10.85

6.03

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 * 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 

manganifem, 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

i Jour. Chem. Soc., vol. 92, pt. 2,1907, p. 888, abstract.
MINERAL WELLS AND SPRINGS. 195

in large quantities, great bodies of sinter are produced, and this has 

a composition approaching that of opal. Mineralogically, siliceous 

sinter is classed as a variety of opal, for it consists mainly of 

hydrated silica .with variable impurities. According to W. H. Weed,! 

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 algse, 

gradually hardens to suiter. 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. 

Explor. 40th Par., vol. 2,1877, p. 826.

SiOa .........................

41 f)

Fe203 --- -------------------- -

FeO... ...... .................

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

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

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

N&fi. .......................

NaCl........................

HaOo.......................

C....... .....................

S03 - ........................

S. ..........................

A

94.40

} .79

none

none

5.02

100. 21

B

93.60

1.06

trace

.50

4.71

trace

99.87

C

"89. 54

2.12

trace

1.71

.30

1.12

trace

5.13

99.92

D

83.10

6.02

.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

92.67

} .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

J 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 

Selangor, Malay States, contains, with 91.8 per cent of SiOa, 0.5 per cent of Sn02. See S. Meunier, Compt. 

Rend., vol. 110, 1890, p.'l083.

« Mon. U. S. Geol. Survey, vol. 13,1888, pp. 343-346.
196 THE DATA OP GEOCHEMISTRY.

hydroxide, gold, silver, and traces of zinc, manganese, cobalt, and 

nickel. 

The following analyses represent sinters from foreign localities: *:

Analyses of sinters from foreign localities.

G. Geyserite, Iceland. Analysis by A. A. Damour, Bull. Soc. g6ol. Prance, 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, Phil. Mag., 4th ser., 

vol. 5,1853, p. 285.

J. Sinter from geysers of Rotorua, New Zealand. Analysis by J. E. Whitfleld, discussed by W. H. 

Weed, Ninth Ann. Kept. 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 geyser district of New Zealand, according to J. M. Maclaren (Geol. Mag., 

1906, p. 511), there are also appreciable quantities of gold and.silver.

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

Al O ' '

Fe203 . ..............................-:

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

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

K20. .........................:.......

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

NaCl................................

HoO................. .................

SOg......... ..........................

G

87.67

} .71

.40

.82

10.40

100. 00

H

88.26

.69

3.26

trace

.29

.11

.11

4.79

2.49

100. 00

I

94.20

1.58

.17

.85

3.06

99.86

J

92.47

2.54

.15

.79

3.99

99.94

K

94.02

| 2.27

trace

.07

3.36

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 Yellowstone 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, Allgem. chem. Geol., vol. 1, p. 593.
MINERAL WELLS AND SPRINGS. 197

8iOa .. ...............

M2 03 .. ..............

Fe203 - ---------------

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

Mn02 .......... .......

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

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

Na20................

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

Li20.................

H20..... .............

C02 ... ...............

S03 ..... ..............

s. ....................

AH O

C, organic ............

A

54.36

5.90

25.48

.33

.17

1.86

1.30

1.21

9.60

.28

100. 49

B

50.03

2.15

trace

24.18

.32

.24

4.78

12.92

5.40

100. 02

C

54.22

18.03

.86

.32

.49

3.82

7.12

15.41

100. 27

D

21.36

3.11

9.17

6.19

38.65

.82

7.50

13.02

.09

99.91

E '

68.73

6. DO

.29

2.14

6.15

18.79

none

99.76

F

29.23

trace

1.91

.07

.50

3.03

64.29

1.04

100. 07

G

49.83

4.74

18.00

10.62

17.37

100. 56

H

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, FeAsO4 .2H20. This occurs still more perfectly at Joseph's 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 thrown 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.

i A. Hague, Am. Jour. Sci., 3d ser., vol. 34,1887, p. 171. See also J. E. Whitfleld, Bull. U. S. Oeol. Survey 

No. 55,1889, p. 65.
198 THE 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 

dissolved is redeposited as stalactite or stalagmite. In reactions of
MINERAL WELLS AND SPRINGS. 199

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 Daubre"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 

in 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 slightest trace of blurring. This 

observation has been confirmed by Chase Palmer. The water

1 On the magnitude of erosion by subterranean waters see H. Schardt, Bull. Soc. neuchateloise sci. nat., 

vol. 33,1907, p. 168.

2 Am. Jour. Sci., 4th ser., vol. 2,1896, p. 100.

s Etudes synth6tiques de geologic expe'rimentale, 1879, pp. 179 et seq. Other localities at which similar 

changes have been observed are also described. The Plombieres water is said to be a very dilute solution 

of alkaline silicates, but its exact composition is not given by Daubree. 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 DaubreVs statement.

< See Chapter HI for details on this subject. Also A. A. Julien, Proc. Am. Assoc. Adv. Sci., vol. 28, 

1879, p. 311.
200 THE DATA OF GEOCHEMISTRY.

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 precipitated, 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 

B,. A. Duncan 1 on Hawaiian soils show that a layer 6 inches thick 

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 Bemmelen 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

' 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 AND SPRINGS. 201

sources either a direct mixture or a solution from which ingredients 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. The 

Hunyadi Janos water is obtained from wells sunk near a mass of 

pyritiferous dolomite, and therefore its high proportion of magnesium sulphate is readily intelligible. 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 rhyelites, 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 formations is doubtless true; but beyond that it is hardly safe to generaliz.e. It is better to discuss each water by itself, and so seek to 

interpret its individual history.

VADOSE AND JUVENILE WATERS.

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

i Compt. Rend., vol. 108,1889, p. 149.

a A. C. Lane (Water-Supply Paper 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.
202 THE DATA OF GEOCHEMISTRY.

reopening of the question. E. Suess, 1 speaking with especial reference 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 magmatic waters, 

furthermore, are regarded by some authorities as the carriers of 

metallic salts, by which certain kinds of metalliferous veins have been 

filled.2

This subdivision of springs into vadose, or those which represent 

original infiltrations 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,3 

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 drouth. 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 commingled.

THERMAL SPRINGS AND VOLCANISM.

The work of Gautier, just cited, is intimately related to an earlier 

memoir,4 in which the close connection between volcanism and the

1 Geog. Jour., vol. 20,1902, p. 520. From a German original, which I have not seen. On the other hand, 

see E. H. L. Schwartz, Geol. Mag., 1904, p. 252; and J. M. Maclaren, idem, 1906, 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 the geyser waters of the Yellowstone National Park. See Scribner's Mag., May, 1904, 

p. 513, and Trans. Am. Inst. Min. Eng., vol. 16, 1887, p. 783; also his presidential address in Bull. Geol. 

Soc. America, vol. 22,1911, p. 103, and Science, vol. 33, p. 555.

2 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.

8 Compt. Rend., vol. 150,1910, p. 436. Other papers bearing on this subject, and on the origin of thecarbon 

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; P. Henrich, Zeitschr. prakt. Geologie, 

1910, p. 85; and O. Stutzer, idem, p. 346.

< 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. 688.
MINERAL WELLS AND SPRINGS. 203

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 

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 region, 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 1 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 sulpho-silicates, 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 ?

1 Compt. Rend., vol. 132, 1901, p. 740..

2 Helvite and danalite are other natural sulphosilicates widen might easily take part in the supposed 

reactions.

3 On vadose and juvenile carbonic acid in waters, see an elaborate discussion by B. Delkeskamp, Zeitschr. 

prakt. Geologic, 1906, p.-33; reviewed by W. Lindgren, Econ. Geology, vol. 1, 1906, p. 602.
204 THE DATA OF GEOCHEMISTBY.

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 

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 Hot 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 R. 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. Eock 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. No. 41, Agr. Exper. Sta.

South Dakota, 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. 

W. ANDERSON. Mineral springs and health resorts of California, San Francisco, 1892.

Contains many analyses, the greater number of them by the author.

1 Am. Jour. Sci., 4th ser., vol. 20,1905, p. 168.

2 Trans. Am. Electrochem. Soc., vol. 8,1905, p. 291.

3 Bull. U. S. Geol. Survey No. 395,1909,
MINEKAL WELI/S AND SPEINGS. 205

L. DE LAUNAY. Recherche1 , captage et ame"nagement des sources thermomine'rales,

Paris, 1899. 

A. CAKNOT and others. Analyses of French and colonial mineral waters: Annales des

mines, 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 Prance, Paris, 1894. Many

analyses and descriptions of the springs.

 GUYON. Etudes sur les eaux thermales de la Tunisie, Paris, 1864. 

M. HANRIOT. Les eaux mine'rales de I'Alg^rie, Paris, 1911. 

A. PvAiMONDi. Aguas minerales del Peru: El Peru, estudios mineraldgicos y geo!6gicos,

vol. 4, 1902, pp. 235-394.

L. DARAPSKY. Aguas minerales de Chile, Valparaiso, 1890. 

E. ABELLA Y CASARIEGO and J. DE VERA Y GO"MEZ. Estudio descriptive de algunas

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. 

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 systematic 

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 chemical 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 

ill 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 

206
SALINE EESIDUES. 207

in either ancient or modern times. 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 

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 alternations 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 substance 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 * 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

1 Annales chim. phys., 3d ser., vol. 27,1849, pp. 92,172.
208 THE DATA OF GEOCHEMISTRY.

different stages of the process. The four analyses, reduced to ionic 

form and to percentages of total solids, appear as follows:

Analyses of Mediterranean water and bitterns,

A. The water itself, density 1.0258. 

B. Bittern of density 1.21. 

C. Bittern of density 1.264. 

D. Bittern of density 1.32.

01.............................................

Br............................................

so4 .'.........................................

COs...........................................

Na ...........................................

K.......... ...................................

Ca.. ..........................................

Mg......... ............................. ......

Salinity, Der cent .............................

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 hid down in concentration of sea water.

Density .0

1. 0258 

1. 0500 

1. 0836 

1. 1037 

1. 1264 

1.1604 

1. 1732 

1. 2015 

1. 2138 

1. 2212 

1. 2363 

1. 2570 

1. 2778 

1. 3069

Tpta 

Salts in las

Sum

Volume.

1.000 

.533 

.316 

.245 

.190 

. 1445 

.131 

.112 

.095 

.064 

.039 

.0302 

.023 

.0162

il deposit. . 

t bittern. .

L. .........

Fe203.

0. 0030

.0030

.0030

CaC03.

0. 0642 

trace 

trace 

.0530

.1172

.1172

CaSO< 

2H2 0.

0. 5600 

.5620 

.1840 

.1600 

.0508 

.1476 

.0700 

.0144

1. 7488

1. 7488

NaCl.

3. 2614 

9. 6500 

7. 8960 

2. 6240 

2. 2720 

1. 4040

27.1074 

2. 5885

29.6959

MgSO*.

0. 0040 

.0130 

.0262 

.0174 

.0254 

.5382

.6242 

1. 8545

2. 4787

MgCl2.

0. 0078 

.0356 

.0434 

.0150 

.0240 

.0274

.1532 

3. 1640

3. 3172

NaBr.

0. 0728- 

.0358 

.0518 

.0620

.2224 

.3300

.5524

KC1.

0. 5339

.5339

a Given by Usiglio in Baumd degrees. Restated here in the usual specific gravities.
SALINE RESIDUES. 209

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 

localitiesatwhich.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 evidences 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 of 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.2 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

> Lehrbuch der chemischen und physikalischen Geologic, 2d ed., vol. 2,1864, p. 48.

s Die Bildung der Steinsalzlager und ihrer Mutterlaugensalze, Halle, 1877. See also a short paper in Proc. 

Acad. Nat. Sci. Philadelphia, 1888, p. 181. Ochsenius was sharply criticized by J. Walther in Das Gesetz 

der Wustenbildung, Berlin, 1900. Ochsenius replied ha Centralbl. Min., Geol. u. Pal., 1902, pp. 551,557,620; 

and a rejoinder by Walther appeared in the same journal, 1903, p. 211.

101381° Bull. 491 11 14
210 THE DATA OF GEOCHEMISTRY.

evaporation. Evaporation, of course, takes place only at the surface, 

and the upper layers, thus becoming denser, must sink, so producing 

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 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 part of 

the programme has yet been performed.

This theory of Ochsehius, 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 

layer 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 

with that of the original sheet of water the depth of the deposit might 

be very great. Such a deposit might also be reenforced by leachings 

from other salt beds, or from diffused salt in adjacent areas, a process 

which is now going on in the valley of the Dead Sea.

THE STASSFURT SALTS.

In the Stassfurt, or, more properly, the Magdeburg-Halberstadt 

region, the. order of deposits is as follows, going from the surface 

downward: 1

1. Drift, about 8 meters thick.

2. Shales, sandstones, and unconsolidated clays, of varying thickness.

3. Younger rock salt, thickness very variable, sometimes missing.

i From data given by H. Precht in Die Salz-Industrie von Stassfurt und Umgegend, 1889; L. Loewe, 

Zeitschr. prakt. Geologie, 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. Pfeiffer, 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 thesalinebeds by H. Everding, and their chemistry, 

by E. Erdmann, with exhaustive bibliographies. See also C. Riemann, Die Geologie der deutschen 

Salzlagerstiltten, Stassfurt, 1908;and H. E. Boeke, Uebersicht der Mineralogie, Petrographie, und Geologie 

der Kalisalzlagerstatten, Berlin, 1909.
SALINE, RESIDUES. 211

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 millimeters. 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 1 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 thirty 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 simple 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 in the 

salts and also iodine,3 and copper is reported by W. Biltz and

i 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.

a Pfeifler, Arch. Pharm., 3d ser., vol. 27, 1890, p. 1134. On the salt clay see E. Marcus and W. Biltz, 

Zeitschr. anorg. Chemie, vol. 08,1910, p. 91. Vanadium was detected in it.

s On bromine seeH. E. Boeke, Zeitschr. Kryst. Min., vol. 45,1908, p. 346. On iodine, A. Frank, Zeitschr. 

angew. Chemie, 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. Kraze, however, found it in the salts from Neu Stassfurt, Bleicherode, and 

Kalusz.
212 THE DATA OF GEOCHEMISTRY.

E. Marcus, as well as ammonium and nitrates. 1 Helium occurs in the 

salts in traces. 2

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 3 .........................CaS04 .2H20.

Glauberite........................ .CaS04 .Na2SO4 .

Polyhalite.........................2CaS04 .MgS04 .K2S04 .2H20.

Krugite...........................4CaS04 .MgS04 .K2S04 .2H20.

Kieserite..........................MgS04 .H20.

Epsomite......................... MgS047H20 (reichardtite).

Vanthoffite.......................MgS04 .3Na2S04 .

Bloedite...........................MgS04 .Na2S04 .4H20 (astrakanite).

Loewite...........................MgS04 .Na2S04 .2£H20.

Langbeinite...................... .2MgS04 .K2S04 .

Leonite..........................MgS04 .K2S04 .4H20.

Picromerite........................MgS04 .K2S04 .6H20 (schoenite).

Aphthitalite..............\....... K3Na (S04)2 (glaserite) . 4

Kainite................... 1......MgS04 .KC1.3H20.

Celestite, SrSO4 , 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,5 the 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 hydration, 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, 

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 vanthoffite, also anhydrous,

1 Zeitschr. anorg. Chemie, vol. 62,1909, p. 183; vol. '64,1909, p. 236.

2 R. J. Strutt, Proc. Eoy. Soc., vol. 81, ser. A, 1908, p. 278. E. Erdmann, Ber. Deutsch. chem. Gesell., 

vol. 43,1910, p. 777.

3 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 Ca2S208.4H2 0, and the hemihydrate, Ca^Os.HzO, a 

well-known artificial compound, furnishes evidence in favor of the higher formula.

* 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. Chemie, vol. 56,1906, 

p. 212) question the definiteness of the mineral, and regard it as a mixture of the two component sulphates.

6 Zeitschr. angew. Chemie, 1897, p. 68.
SALINE BESIDUES. 213

is associated with aphthitalite and loewite in the same horizon. The 

loewite is probably formed by dehydration of bloedite,1 and the 

vanthoffite 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, kieserite, 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 still being continued. 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 "Hartsalz" contains these substances together with kieserite. 

Douglasite, K2FeCl4 .2H20.(?) 

Carnallite, KMgCl3 .6H20.

Tachhydrite, 2MgCl2 .CaCl2 .12H20=3(RCl2 .4H20).4 

Bischofite, MgCl2 .6H20.

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

1 See J. H. Van't Hoff, Sitzungsb. Akad. Berlin, 1902, p. 414. Also Van't Hofl and W. Meyerhoffer, 

idem, 1903, p. 678; 1904, p. 659.

2 Mineralog. Mag., vol. 12,1899, p. 159.

s Van't Hofl 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 Salzablagerungen, Braunschweig, 1905; and an 

address in Ber. Internat. 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, 1906, p. 7. For a graphic 

representation of the saline associations see also H. E. Boeke, Zeitschr. Kryst. Min., vol. 47,1910, p. 273.

* Boeke, in a private communication, suggests that if the formula of carnallite is doubled, to 

K2Mg2Cl0.12H2O, tachhydrite becomes CaMg2Cla.l2H2O. That is, the salts are analogous, Ca in one 

replacing K2 in the other.
214 ' THE DATA OF GEOCHEMISTRY.

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," 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 doubtfulAnother mineral, rinneite, discovered by him in the "Hartsalz" of 

Saxony and the Harz, has the formula FeCl2 .3KCl.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.

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 

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

1 Sitzungsb. Akad. Berlin, 1902, p. 1106. See also J. H. Van't Hoff, F. B. Kenrick, and H. M. Dawson, 

Zeitschr. physikal. Chemie, vol. 39,1902, p. 27, on the conditions of formation of tachhydrite.

2 Centralbl. Min., Geol. u. Pal., 1904, p. 254.

a Neues Jahrb., 1909, pt. 2, p. 19. For 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 Stassfurt beds in Neues Jahrb., 1911, vol. 1, p. 48, and Centralb! 

Min., Geol. u. Pal., 1911, p. 48. See also F. Rinne and R. Kolb, idem, p. 357.

« O. Schneider- (Centralbl. Min., Geol. u. Pal., 1909, p. 503) regards the NaCl of rinneite as a 

mechanical admixture.
SALINE RESIDUES. 215

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 

tne 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 

rock salt, containing, with other impurities, from 6 to 7 per cent of 

the new mineral. Possibly syngenite, CaK2 (SO4 ) 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.5 The occurrence of

1 Zeitschr. angew. Chemie, vol. 21,1908, p. 1685. A short additional communication by Erdmann is in the 

same journal, vol. 22,1909, p. 238.

2 Cf. G. Lunge, Thorpe's dictionary of applied chemistry, vol. 3,1893, p. 268.

a According to J. H. Van't Hofi and F. Weigert, Sitzungsb. Akad. 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 Hofi 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.

» E. E. Basch, Sitzungsb. Akad. Berlin, 1900, p. 1084.
216 THE DATA OF GEOCHEMISTRY.

syngenite at Kalusz is below the potassium salts, in rock salt containing anhydrite. It is therefore the equivalent of polyhalite in position.1 

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 2 have shown that when magnesium chloride and sulphate are 

dissolved together and the solution then evaporated upon the 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.3 Beds of anhydrite may take up water and be 

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 4 as follows:

1. Glauberite, formed above 10°.

2. Langbeinite, formed above 37°.

 1 A. Aigner (Oesterr. Zeitschr. Berg- u. Hiittenwesen, 1901, p. 686) has described the Austrian polyhalite. 

For analyses of kainite, carnallite, etc., from Kalusz and Aussee, see C. von John, Jahrb. K.-k. geol. 

Keichsanstalt, vol. 42, 1892, p. 341. On mirabilite from Kalusz, see K. Zalozlecki, Monatsh. Chemie, 

vol. 13, 1892, p. 504. Two papers on the potash salts of Austria and the Tyrol by R. Gorgey are in Min. 

pet. Mitt., vol. 28,1909, p. 334, and vol. 29,1910, p. 148.

a Ber. Deutsch. chem. Gesell., vol. 14,1881, p. 2131.

s Cf. F. Hammerschmidt, Min. pet. Mitt., vol. 5,1882-83, p. 272; and J. F. McCaleb, Am. Chem. Jour., 

vol. 11,1889, p. 34.

Zeitschr. Elektrochemie, vol. 11,1905, p. 709.
SALINE. RESIDUES. 217

3. Loewite, formed above 43°.

4. Vanthoffite, formed above 46°.

5. Loewite with, glaserite, formed above 57°.

6. Loewite with vanthoffite, formed above 60°.

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.1

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 ife 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 constitutents 

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. 2 Here the origin from sea water is evident. On the 

other hand, waters containing little or no salt often deposit gypsum. 

I. C. Russell,3 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 common as an efflorescence or incrustation in caves,4 and it can be produced by the alteration of other rocks. The oxidation of pyrites in 

limestone may form gypsum; or, as was shown in the preceding chapter, it can originate from double decomposition between other metallic 

sulphates and calcium carbonate. L. W. Jowa,5 for example, prepared selenite in measurable crystals by the action of a solution of 

ferrous sulphate on chalk.

1 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 Hofl, Sitzungsb. Akad. Berlin, No. 39, 1910, 

p. 772.

« J. D. Dana, Manual of geology, 4th ed., p. 120.

» Mon. U. S. Geol. Survey, vol. 11, 1885, p. 84. The deposition of gypsum by Lake Chichen-Kanab, 

Yucatan, was mentioned in Chapter V (p. 153).

« See G. P. Merrill, Proc. U. S. Nat. Mus., vol. 17, 1905, p. 77.

 Annales Soc. g6ol. Belgique, vol. 23, 1895-96, p. cxxviii.
218 THE DATA OF GEOCHEMISTRY.

In the Salina formation of New York gypsum occurs above the 

salt, and its presence is attributed by Dana 1 to the alteration of the 

overlying "Waterlime" 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. 2 At Goderich, 

Canada, a similar but not identical alternation has been observed.3 

Here a boring 1,517 feet deep revealed dolomite and anhydrite, and 

above that were six beds of salt alternating with similar materials. 

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 concentration, or else quite independent of the salt below. Throughout 

the region of salt more or less anhydrite was found, but potassium 

compounds were either absent or present only in traces. Neither 

in New York nor in the Goderich deposits were the mother liquors 

permitted to crystallize.4

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 

beds were regarded as of marine origin. 5 Later, R. T. Hill 6 interpreted them as derived from hot saline waters rising from great 

depths, and a similar view was put forth by L. Hager. 7 E. Coste,8 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 

received its final interpretation. 9 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.

1 Manual of geology, 4th ed., p. 554.

2 See sections given in Bull. New York State Mus. No. 11,1893.

»T. S. Hunt, Geol. Survey Canada, Kept. 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.

6 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.

6 Jour. Franklin Inst., vol. 154,1902, p. 273.

' Eng. and Min. Jour., vol. 78,1904, pp. 137,180.

8 Jour. Canadian Min. Inst., vol. 6,1903. p. 73.

9 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.
SALINE RESIDUES. 219

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.1

Analyses of rock salt.

A. Salt from Goderich, Canada. Analysis by Gould, for T. Sterry Hunt, Geol. Survey Canada, Kept. 

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. 

C6rdoba, 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. 162.

NaCL......... ........

KC1........ '..........

CaCl2 . ................

MgCla ......... ........

Na2S04 ...............

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

CaS04 ................

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

NaaC08 ................

A1203 - .. .............

Fe203 - ---------------

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

Insoluble.. ...........

H20. .................

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 .1313

.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

In addition to the impurities shown in the analyses, rock salt frequently contains gaseous inclusions. These have been often examined, recently by N. Costachescu, 2 who finds some of them to consist

1 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 Roumanian salt. Some Roumanian 

samples contain as high as 99.9 per cent of sodium chloride.

2 Ann. Univ. Jassy, vol. 4,1906, p. 3. The author gives a good summary of earlier investigations.
220 THE DATA OF GEOCHEMISTBY.

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, 1 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. 2

Analyses of gypsum.

A. From Hillsboro, New Brunswick. Analysis by George Steiger. 

B. From Alabaster, Michigan. Analysis by Steiger. 

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.

so8 ... .............................

C02 ..................................

01.... .................................

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

Al O

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

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

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

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

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

H2O...... ............................

A

46.18

} ,0

32.37

1 ,n

20.94

.10

99.79

B

46.18

.03

.08

32.33

.05 } I4

20.96

.05

99.82

C

45.45

.85

.10

.12

32. 44

.33

20.80

100. 09

D

48. 14

.65

35.29

15.88

99.96

E

39.53

7.73

.04

I .H

38.46

.24

.07

.19

12.69

.45

99. 54

BITTERNS.

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 bittern are not often

1 Physikal. Zeitschr., vol. 6, 1905, p. 855. See also L. Wohler and H. Kasarnowski, Zeitschr. anorg. 

Chemie, vol. 47,1905, p. 853, and F. Cornu, Centralbl. Min., Geol. u. Pal., 1907, p. 166, and Neues 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. Deutsch. chem. Gesell., vol. 43, p. 777) ascribes the blue of salt to 

radioactivity, which is known to effect color changes in minerals.

2 For other data relative to the composition and origin of gypsum, see G. P. Grimsley and E. H. S. Bailey, 

Univ. Geol. Survey Kansas, vol. 5,1899. Also E. C. Eckel, 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 Kept. State Geologist, New 

York State Mus., 1903; and G. I. 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. Newland and H. 

Leighton, Bull. New York State Mus. No. 143,1910.
SALINE RESIDUES. 221

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. Bittern from "bay salt," Alameda Bay, California. Analysis by F. Gutzkow, cited in W. L. Rowland's report on salt, vol. 2, Tenth U. S. Census, 1883. 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. 44,1867, p. 80.

C. Bittern from the brine of Bay City, Michigan. Analysis by E. S. Fitch, cited by W. F. Cooper, Eept. 

State Board Geol. Survey Michigan, 1905, p. 389.

D. Bitterr from the saline of Medellin, Antioquia, Colombia. Analysis by J. B. Boussingauit, Annales 

chim. phys., 5th ser., vol. 2,1874, p. 102. Known locally as "oil of salt."

E. Bittern from salt works of Allendorf-an-Werra, Germany. Analysis by E. Reichardt, abstract in 

Jour. Chem. Soc., vol. 42,1882, p. 24.

01..... ...............................

Br............................ .........

I.....................................

S04 .................... ...............

Na....................................

K....................................

Li.....................................

NH4 ...................................

Ca...................................

Mg...................................

Al......... ...........................

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

Organic. ..............................

A

52.63

.27

15.14

18.89

1.88

11.19

100. 00 

34. 555

B

fiO 00

1.16

trace

.06

10.24

5.27

11.26

8.08

100. 00 

33. 567

C

55.15

19.25

.52

4.00

9.34

. 5.16

6.58

100. 00 

9.045

D

44.99

1.02

.03

14.07

25.97

11. 18

trace

.09

.28

2.37

100. 00 

33. 478

E

KK KC

.22

15.08

10.62

6.40

.01

.07

8.81

.02

3.21

100. 00 

29. 149

The excess of calcium over the amount deposited as gypsum is very 

striking in the Syracuse example. In A, D, and E calcium has been 

almost entirely deposited, and a large excess of the sulphuric ion 

appears. The concentration of potassium is also well shown in two 

of the bitterns.

The bittern from Michigan is remarkable for its very high proportion of bromine, and the analysis may not be correct. Still, the 

Michigan brines are important commercial sources of bromine, and 

so, too, are those of the Kanawha Valley, in West Virginia. For the 

latter I have found no satisfactory analyses. 2 A. L. Baker 3 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 veryappreciable amounts, from 38.4 to 59.2 milligrams per liter. The

1 In addition to Usiglio's analyses cited on p. 208, ante.

2 The Tenth Census report, previously cited, gives two analyses of bittern from Midland, Michigan, and 

an incomplete analysis of one from the Kanawha region; but they are not sufficiently conclusive to warrant 

reproduction.

^ Chem. News, vol. 44,1881, p. 207.
222 THE DATA OF GEOCHEMISTRY.

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.

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 winter 

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 the shore. The salt thus 

formed is the decahydrate, mirabilite, Na2S04 .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 Koumania,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 above is for the sake of simplicity. Their subdivision 

does not help to illustrate the phenomena now under discussion.

1 G. K. Gilbert, Mon. U. S. Geol. Survey, vol. 1,1890, p. 253.

2 L. Mrazec and W. Teisseyre, Apergu g6ologique sur les formations saliferes et les gisements de.sel en 

Roumanie, 1902. This memoir contains a bibliography relative to Roumanian salt, 

s Zeitschr. prakt. Geologic, vol. 11,1903, p. 401. Cf. ante, p. 159.
SALINE RESIDUES. 

Analyses of saline deposits in two Siberian lakes.

223

A. Deposit on bottom of Lake Altai. 

B. Deposit on shore of Lake Altai. 

C. Deposit on shore of Schunett Lake.

C02 . ..................................................

en

Na20.................................................

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

NaCl...................................................

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

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

A1203 . ................................. : ..............

FeA................. .................................

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

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

\ «

Ql

QQ 07 uy. a i

C

0.63

54.45

25.96

, 1.93

.92

.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 their 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.

N^,S04 .. .......................................................

Na2C03 . .......................................................

NaCl. .........................................................

CaS04 .. ........................................................

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

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

H o

Margin.

14.3

75.8

5.5

.7

3.6

.1

100. 0

Center.

84.6

.4

7.0

8.0

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.

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

» G. K. Gilbert, Mon. U. S. Geol. Survey, vol. 1,1890, pp. 224-227. See p. 145, ante, for the composition 

of the brine.
224 THE DATA OF GEOCHEMISTRY.

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 borates occur, separately or altogether, and many analyses of these products have been 

recorded. To the sulphato-chloride class the subjoined analyses belong, the other saline deposits being left for separate consideration

later. 2

Analyses of saline deposits from sulphato-chloride waters.

A. Salt, Osobb Valley, Nevada. Analysis by R. W. Woodward, Rept. U. S. Geol. Explor. 40th Par., 

vol. 2,1877, p. 707.

B. Saline efflorescence on desert, south of Hot Springs station, Nevada. Analysis by O. D. Alien, idem, 

p. 773.

C. Incrustation from Quinns River crossing, Black Rock Desert, Nevada. Analysis by 0. D. Alien, 

idem, p. 791.

D. Salt from Salt Lake, 7 miles east of the Zandia Mountains, New Mexico. Analysis by 0. Loew, Rept. 

U. S. Geol. Surv., W. 100th Mer., vol. 3,1875, p. 627.

E. Efflorescence from alkali flat, near Buffalo Spring, Nevada. Analysis by 0. D. Alien, op. cit., p. 731.

F. Efflorescence from Santa Catalina, Arizona. Analysis by O. Loew, op. cit., p. 628.

G. Salt from shore of lake near Percy, Nevada. Analysis by R. W. Woodward, Rept. U. S. Geol. Explor. 

40th Par., vol. 2,1877, p. 148.

H. Efflorescence on loess, near Cordoba, Argentina. Analysis by Doering, cited by A. W. Stelzner, 

Beitrage zur Geologie und Palaeontologie der Argentinischen Republik, 1885. A number of salts, etc., are 

described on pages 295-309. This one is remarkably rich in potassium.

NaCl.................

Na2S04 ................

NazCOs-. .............

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

MgCl2 .... .............

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

CaS04 ....... ..........

H,0... ................

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

4.66

100. 00

E

70.81

26.38

1.94

99.13

F

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

1 Das Gesetz der Wiistenbildung, Berlin, 1900, p. 149. Chapter 13 is devoted to the subject of desert salts. 

8 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.
SALINE RESIDUES. 225

These analyses, taken in connection with those of salt given on page 

219, 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 has gone on to 

a greater or less extent; hut 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 often form " playas," 01'" 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.

Analyses of incrustations deposited by alkaline lakes.

A. From western arm of Black Hock Desert, near the so-called "Hardin City," Nevada. Analysis by 

0. 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 Peko station, 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. 

G. 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,C03 . ..............

NaHC03 .............

Na2S04 ................

NaCL................

Na2B407 ---------------

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

KOI...... ..........

SiOa .......... ........

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

1.39

2.18

100. 00

' See I. C. Russell, Mon. U. S. Geol. Survey, vol. 11,1885, p. 81.

2 The analyses are here cited as recalculated by T. M. Chatard, Bull. U. S. Geol. Survey No. 60, 1890, 

pp. 55,56. The original statements do not adequately discriminate between carbonates and bicarbonates.

101381° Bull. 491 11 15
226 THE DATA OF GEOCHEMISTRY.

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

r\r\

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

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

(NH4 )2C03 .- .......... ........................

A

65.72

3.98

8.42

20.23

1.65

100. 00

B

62.22

10.57

K ^Q

20.62

100. 00

C

32.58

25.28

14.75

19.78

2.25

3.95

1.41

100. 00

D

75.95

4.67

1.46

12.98

4 Q4

100. 09

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 

by T. M. Chatard. 2 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 0. D. Alien, Kept. U. S. Geol. Explor. 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.

Na2C03 . ..............................................

NaHC03 ... ............................................

Na2S04 . ...............................................

NaCl... ................................................

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

H20. ..................................................

A

45. 05

34.66

1.29

1.61

.80

16.19

99.60

B

44.25

34.90

QQ

1.10

2.81

1 ^ Q^

100. 00

C

52.20

25.05

5.10

3.31

.27

14.16

100. 09

1 Appendix, Rept. Univ. California Exper. Sta., 1890. Other analyses are given in this report.

2 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.
SALINE RESIDUES. 227

These soda lakes also deposit crystals of gaylussite, of the formula 

CaC03.Na2C03.5H20,1 although the analysis of the water 2 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 3 

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 

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.

1 See analysis by O. D. 'Alien, Kept. U. S. Geol. Explor. 40th Par., vol. 2,1877, p. 749.

2 See p. 150, ante, for analysis of the water.

s Natural soda; its occurrence and utilization: Bull. U. S. Geol. Survey No. 60,1890, pp. 27-101. Cf. E. 

Le Neve Foster, Proc. Colorado Sci. Soc., vol. 3,1890, p. 245, for data concerning Owens Lake. See also 

G. Lunge, Zeitschr. angew. Chernie, 1893, p. 3.
228 THE DATA OF GEOCHEMISTRY.

Analyses of salts deposited by fractional crystallization from water of Owens 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 on page 150 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.

HaO............. .............

NaaCOg......................

NaHCOg......... .............

NaaS04 .......................

NaCl......... ..............

Na2B407 ......................

NaB02 .. ....................

KC1....... ...................

(CaMgXJOg............. .......

(AlFe) a08 ........ ............

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

Organic matter. ...............

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

J.07

.14

.01

.055

.032

.078

100. 385

C

4.33

22.84

10.53

25.44

35.06

1.12

.09

99.41

D

3.43

18.19

4.06

26.70

45.59

1.14

. Ub

99.17

E

2.24

12.51

3.88

19.01

60.99

1.21

.01

.05

99. 90

F

11.03

55.04

4.09

5.70

19.16

a2.01

2.93

.02

.16

100. 14

a Chatard supposes that the biborate could not exist in so strongly alkaline a solution as the mother 

liquor from which this crop was obtained.

From these analyses we see that the first crop of crystals consists 

largely of trona, Na2C03 .NaHCO3 .2H2O, 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 hi 

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 

the first column below, which is compared with the composition as 

calculated theoretically.

Composition of trona from Owens Lake, California.

Na2C03 ... . ................................................

NaHC03 . .................................................

NaCl. .....................................................

NajS04 .............. ........................................

HaO.... ..................................................

Found.

45.86

36.46

.32

1.25

16. 16

.02

100. 07

Calculated.

46.90

37.17

15. 93

100. 00

i Cf. also C. WinkJer, Zeitschr. angew. Chemie, 1893, p. 446; and B. Reinitzer, idem, p. 573.
SALINE. E.ESIDUES. . 229

The prevalent view concerning the origin of the Lahontan alkalies 

was stated in Chapter V (p. 149). 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 is 

accepted by E. von Kvassay 3 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 4 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

1 See analyses by T. M. Chatard, Bull. U. S. Geol. Survey No. 60,1890, 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.

s 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.

1 Am. Jour. Sci., 4th ser., vol. 2,1896, p. 123. See also paper in Kept. Univ. California Agr. Exper. Sta., 

1890, p. 87, followed by an experimental research by M. E. Jaffa.
230 . THE DATA OF GEOCHEMISTRY.

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,1 

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, 2 who examined the natron lakes of Egypt, observed the presence in them of algae, 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,3 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 waters contain 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.4 First, by 

direct derivation from volcanic rocks. Second, by reduction of 

alkaline sulphates. Third, by double decomposition between calcium bicarbonate and alkaline sulphates 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

1 Ber. Deutsch. chem. Gesell., vol. 29, 1896, p. 1034. See also a memoir by H. Vater, Zeitschr. Kryst. 

Min., vol. 30,1899, p. 373.

2 Chem. Zeitung, 1892, pp.-1645,1691.

8 Zeitschr. Gesell. Erdkunde, vol. 33,1898, p. 1. Several references to bacteriologic researches are given 

in this memoir.

« 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 EESIDUES. 231

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."

BORATES.

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 

in dealing with this class of compounds. Let us first examine the 

actual occurrences of borates as saline residues.2

Borax Lake, Lake County, California, has been repeatedly described.3 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 Chaguarama

1 The reports of the Bureau of Soils, U. S. Dept. Agr., and of the agricultural experiment stations of several Western States contain abundant literature on this subject. The report of the 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 the 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. Headden, Am. Jour. Sci., 4th ser., vol. 27,1909, p. 305.

2 For general information about American localities see Mineral Resources U. S. for 1882, p. 566; 1883-84, 

p. 858; 1889-90, p. 494; and 1901, p. 869, U. S. Geol. Survey.

3 Geol. Survey California, Geology, vol. 1, 1865, p. 97. G. F. Becker, Mon. U. S. Geol. Survey, vol. 13, 

1888, pp. 264-268. H. G. Hanks, Third Ann. Rept. State Mineralogist (California). For analyses of the 

water and of an adjacent hot spring, see ante, pp. 150,136. This lake, situated about 80 miles north of 

San Francisco, must not be confused with Searles's "Borax Lake" in San Bernardino County.
232 THE DATA OF GEOCHEMISTRY.

Valley, in Venezuela,1 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 Vulcano; 2 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................................'... H3B03 (orthoboric acid).

Larderellite................................. (NH4 )2B8 013 .4H20.

Bechilite................................... CaB407 .4H20 (borocalcite).

Lagonite................................... Fe^^O^R^O.

One of these salts is an ammonium borate, and another ammonium 

compound boussingaultite, (NH4) 2Mg(S04 ) 2 .6H20 is also formed 

at this locality. According to C. Schmidt 3 the condensible vapors 

from the fumaroles of Monte Cerboli contain boric 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 4 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:

Foreign matter in Tuscan lagoon waters. 

[Grams per liter.]

Castelnuovo. ...............................

Larderello. ..............................

Monte Rotondo, uppermost lagoon. ..........

Monte Rotondo, lowest lagoon. ............

Total solids.

8.565

6.720

2.005

22.575

Boric acid 

(H3B03 ).

4.154

4 039

1.100

19.300

Ammonium 

.sulphate.

1.695

.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 boric acid had been deposited. I have reduced his analysis 

to percentages of total solids, arid essentially to ionic form, except 

that for the excess of boric acid I prefer to use the symbol H3B03 .

" See E. Cortese, Eng. and Min. Jour., vol. 78, November 10, 1904. 

2 See A. Bergeat, Zeitschr. prakt. Geologie, 1899, p. 45.

s Ann. Chem. Pharm., vol. 98, 1856, p. 273. In vol. 102,1857, p. 190, Schmidt also describes the rocks 

of the region. 

4 Ding, polyt. Jour., vol. 212,1874, p. 493.
SALINE. EESIDUES. 233

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 ............................. 16.71

Grams

per liter.

Ca. ............................. 0.16

Mg.............................. 1.99

(AlFe)2 03 ..........:............ .06

Mn2 03 .......................... 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 the 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 

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." 2 That hypothesis 

was indicated by the presence of hydrogen sulphide in the boronbearing vapors. P. Bolley./ 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,4 in a later 

memoir than the one previously cited, traced 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 boric 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.

1 E,. Warington, Chem. Gaz., 1854, p. 419, with special reference to Vulcano, Lipari Islands. H. SainteClaire Deville and F. Wohler, Ann. Chem. Pharm., vol. 105,1858, p. 71. O. Popp, idem, 8thsupp. Bd., 1870, 

p. 5. E. Bechi, Bull. Soc. ind. 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.

2 See paper by A. Payen on the Tuscan fumaroles, Annales chim. phys., 3d ser., vol. 1,1841, p. 247. Ho 

adopts Dumas's theory.

8 Ann. Chem. Pharm., vol. 68,1848, p. 125.

< Atti Accad. Lincei, 3d ser., vol. 2,1878, p. 514. See also a summary by H. Schiff in Ber. Deutsch. chem. 

Gesell., vol. 11,1878, p. 1690.
234 THE DATA OF GEOCHEMISTRY.

In recent years E. Perrone 1 and R. Nasini 2 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 temperatures 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. 3 Here borax, as such, is found in considerable 

quantities; but the calcium salts ulexite and colemanite are by far the 

more important species.

In Esmeralda County, Nevada, at Teel's marsh, Rhodes's marsh, 

Columbus marsh, and Fish Lake, ulexite, NaCaB509 .8H2O, 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. 4 At 

Rhodes's marsh, according to Joseph Le Conte, 5 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, 6 attributes their borates to leachings 

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 Stassf urt, although its systematic study is hardly more than

i Carte idrographica d'ltalia, No. 31,1904, p. 355. .

a Abstract in Geol. Centrabl., vol. 8,1906, p. 413; and Atti 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. 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. g6ol. France, 2d ser., vol. 6,1848-49, p. 91; C. Sainte-Claire Devilleand 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 "soffloni" have been studied by R. Nasini, F. Anderlini, and R. Salvador! (Atti Accad. 

Lincei, 5th ser., Memorie, vol. 2,1895, p. 388), as well as by some of the above-named 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, isintheBull. Am.Inst. Min. Eng., 1909, p.867.

«Rept. State Mineralogist Nevada, 1871-72, p. 35. v

6 Third Ann. Rept. State Mineralogist California, 1883, p. 51.

6 Bull. U. S. Geol. Survey No. 213,1903, p. 401. See also J. E. Spurr, Bull. U. S. Geol. Survey No. 208, 

1903.
SALINE RESIDUES. 235

begun. Borings at this point, according to De Groot,1 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 

the same area'can be repeatedly worked over. In the workings the 

following mineral species have been found: 2

Anhydrite......................................CaS04 .

Gypsum...................................... .CaS04 .2H20.

Celestite...................................... .SrS04 .

Thenardite......................................Na2S04 .

Glauberite........................................ Na2Ca(S04 )2 .

Sulphohalite 3 ................................. .Na0(S04 )2ClF.

Hanksite.......................................Na22K(S04)0(C03 )2Cl.

Borax...........................................Na2B407 .10H20.

Colemanite.....................................Ca2B6O u .5H20.

Calcite.........................................CaC03 .

Dolomite......................................MgCa(C03 )2 .

Natron.........................................NaC03 .10H2 0.

Trona..........................................Na3H(C03 )2 .2H20.

Gaylussite 4 ...... r.............................Na2Ca(C03 )2 .5HaO.

Pirssonite 4 ................................ ^... .Na2Ca(C03 )2 .2H20.

Northupite 4 ....................................Na3Mg(C03 )2Cl.

Tychite 6 .....................................Na0Mg2 (C03)4S04 .

Halite......................................... .NaCl.

Soda niter. ................................... .NaNCv

Sulphur, from reduction of sulphates.

> Tenth Ann. Kept. California State Mining Bureau, 1890, p. 535.

2 De Groot also mentions cerargyrite, embolite, and gold; but these minerals have no obvious relationship 

to the other species.

3 S. L. Penfleld, Am. Jour. Sci., 4th ser., vol. 9,1900, p. 425.

4 J. H. Pratt, Am. Jour. Sci., 4th ser., vol. 2,1896, p. 123 et seq.; vol. 3,1897, p. 75.

B 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. 19,1890, p. 164, and Compt. Rend., vol. 143,1906, p. 403. The relations between the two species 

are perhaps more clearly expressed by formula) of the following type:

Tychite....................................................... .2MgCO8 .2NasCO3.Na2S04.

Northupite.....................................................2MgCOa .2Na2C08 .2NaCl.

On gaylussite and pirssonite see R. Wegscheider and H. Walter, Monatsh. Chemie, vol. 28,1907, p. 633.
236 THE DATA OF GEOCHEMISTRY.

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. 1 Here, 

interstratified with lake sediments, a solid bed of colemanite exists, 

which ranges from 5 to 30 feet in thickness and is highly crystalline. 

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. From another point in the Mohave Desert a new mineral has been 'reported 2 bakerite having the empirical formula 

8Ca0.5B203 .6Si02 .6H2 0; but its definite character is yet to be ascertained. Priceite, which is probably a massive form of colemanite, 

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 with serpentine.3 Pandermite, another 

variety of the same species, 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 chloride at 110° pandermite was formed to which Van't 

Hoff assigns the formula Ca8B20O38 .15H2O. Colemanite, Ca2B6On .5H2O, 

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.

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.6 This 

locality has been worked for borax, and the deposit is said to be

1 See M. R. Campbell, Bull. U. S. Geol. Survey No. 200; and W. H. Storms, Eleventh Ann. Rept. California State Mining Bureau, 1893, p. 345.

2 W. B. Giles, Mineralog. Mag., vol. 13,1903, p. 353.

3 Information received from J. S. Diller, who has examined the locality.

4 Eng. and Min. Jour., vol. 74,1902, p. 517. I

6 Sitzungsb. Akad. Berlin, vol. 39,1906, pp. 5GC, 689.

o W. D. Dennis, Eng. and Min. Jour., vol. 73,1902, p. 581.
SALINE RESIDUES. 237

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 

less closely, by ulexite. As early as 1844 A. A. Hayes * 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 Bafios 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. Farther east, in 

Argentina, several borate localities are known. J. J. Kyle 5 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,6 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.7 The same view is held by 

A. Jockamowitz 8 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 Phil. Mag., 4th ser., vol. 25,1863, p. 113.

<i Das Department Taltal (Chile), Berlin, 1900. See especially pp. 149,150,163. An abstract is printed in 

Zeltschr. prakt. Geologie, 1902, p. 153.

* An. Soc. cient. Argentina, vol. 10,1880, p. 169.

8 Annales Soc. gfiol. Belglque, vol. 28, M, 1900-1901, p. 99. Analyses of the ulexite are given.

1 1n Chem. Zeltung, 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 

Minlsterio de agricultura, Buenos Alres, 1907. For'an abstract, see Zeitschr. Kryst. Min.,vol.47,1909,p. 205.

s Bol. Cuerpo ing. minas, Peru, No. 49,1907.
238 THE DATA OF GEOCHEMISTRY.

The old localities for borax in Tibet and the. adjacent regions 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:

Boracite...................................... Mg7Cl2B16030 .

Pinnoite......................................MgB204 .3H20.

Ascharite.....................................3Mg2B205 .2H20.

Heintzite...................................... K2Mg4B2203S .14H20.

Hydroboracite(?)........................... .CaMgBflO u .6H20.

Sulphoborite..................................2MgS04 .4MgHB03 .7H20.

Of these species, hydroboracite is found in the lower deposits at 

Stassfurt,3 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.

In the gypsum beds of Nova Scotia ulexite, howlite, and cryptomorphite are found, associated with anhydrite, selenite, mirabilite, 

salt, aragonite, and calcite. 4 Howlite is represented by the formula 

H5CaB2Si014 ; cryptomorphite 5 is probably H2Na4Ca6 (B407 ) 9 .22H2O. 

If this gypsum is, as most authorities assume, a marine deposit, these 

salts occupy a position similar to that filled by hydroboracite at 

Stassfurt; but the total absence of magnesium is rather striking. 6

i Sitzungsb. Acad. Miinchen, vol. 8,1878, p. 518.

»W. S. Vernadsky and S. P. Popofl, Zeitschr. prakt. Geol., 1902, p. 79.

s In his paper on the borates of the German potash salts H. E. Boeke (Centralbl. Min., Geol. u. Pal., 1910, 

p. 531) does not mention hydroboracite. Its identification is perhaps not quite certain.

4 See H. How, Am. Jour. Sci., 2d ser., vol. 32,1861, p. 9; Phil. Mag., 4th ser., vol. 35,1868, p. 31; vol. 41, 

1871, p. 270.

6 Calculated by F. W. C. from How's analysis.

8 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.
SALINE RESIDUES. 239

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, they 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 source 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.1 That boric acid is emittecl from volcanic vents is, however, 

unquestionable. It is there associated with ammonium salts precisely 

as it is at Monte Gerboli 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 our 

borates to leachings 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

1 See, for example, a letter from AV. 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.
240 THE DATA OF GEOCHEMISTRY.

to explain all these deposits by the marine hypothesis, as in the 

memoirs of C. Ochsenius l and L. Dieulafait.2 Dieulafait tries to 

prove that all saline deposits are primarily derived from sea water, 

in either ancient or modern times, and even the Tuscan "somoni" 

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.

(2) Lake-bed deposits contain calcium borates, with nitrates 

near by.

(3) Volcanic waters and fumaroles, when they yield borates, yield 

ammonium compounds also.

1 Zeitschr. prakt. Geol., 1893, pp. 189,217. Borates especially on pp. 222,223.

2 Annales chim. phys., 5th ser., vol. 12,1877, p. 318; vol. 25,1882, p. 145. Also Compt. Rend., vol. 85, 

1877, p. 605; vol. 94,1882, p. 1352; vol. 100,1885, pp. 1017,1240.

3 Some of the Chilean thermal waters, analyzed by P. Martens (Actes Soc. sci. Chili, vol. 7,1897, p. 311), 

contain both borates and ammonium salts, but not in remarkable proportions.
SALINE. RESIDUES. 241 

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. 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.1 This supposition, however, may not cover all cases, for 

W. H. Hess 2 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 3 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 

compounds. The same substance is also reported to occur in large 

quantities at various other points hi southern California, especially 

'around Death Valley and along the boundary between Inyo and 

San Bernardino counties.4 It is said to form beds associated with

1 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, Annaleschim. phys., 4th ser., vol. 7, 

1866, p. 358, followed by a letter from Chabrifi on Algerian saltpeter. M. Glasenapp (Ann. Oeol. Min. 

Rnssie, vol. 12,1910, p. 42, abstract) describes an impregnation of potassium nitrate in the Senonian sand-, 

stones of the Caucasus.

' Jour. Geol., vol. 8,1900, p. 129. The views advanced by Hess have been disputed by H. W. Nichola 

(Jour. Geol., vol. 9,1901, p. 236), who regards guano as the chief source of cave nitrates.

sZeitschr. prakt. Geol., 1893, p. 60.

«G. E. Bailey, Bull. No. 24, California State Mining Bureau, 1902, pp. 139-188.

101381° Bull. 491 11 16
242 THE DATA OF GEOCHEMISTRY.

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,1 the rare 

species darapskite and nitroglauberite, 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,2 are found the largest known deposits of nitrates in the world. 

The crude sodium nitrate is termed locally "caliche," and the u 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,3 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 4 as being made 

up of the following layers: v

Section of typical calichera in Atacama Desert, Chile.

Ft. in.

1. Sand and gravel..................................................... 1-2

2. "Chusca," a porous, earthy gypsum................................... 6

3. A compact mass of earth and stones................................... 2-10

4. "Costra," a low grade caliche, containing much sodium chloride, feldspar, and earthy matter............................................. 1-3

5. "Caliche." (In the Tarapaca Desert it is from 4 to 12 feet thick)......... l£-2

6. "Coba," a clay..................................................... ±3

The costra contains a considerable amount of bloedite; the rarer

minerals, to be mentioned presently, are found in the caliche.

The composition of the caliche is very variable, as the following 

analyses, cited by R. A. F. Penrose, jr., show.5

1 Op. cit., p. 170.

2 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. Forties, Quart. Jour. Geol. Soc., 

vol. 17,1861, p. 7; C. Ochsenius, Zeitschr. Deutsch. geol. Gesell., 1888, p. 153; and L. 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.

4 Jour. Soc. Chem. Ind.,.vol. 12, 1893, p. 128. See also B. Simmersbach and F. Mayr, Zeitschr. prakt. 

Geol., 1904, p. 273.

6 Jour. Geology, vol. 18,1910, p. 14; D. G. Buchanan, analyst. For other analyses see L. Darapsky, Das 

Departement Taltal, Berlin, 1900; A. Zillaruello, An. Soc. cient. Argentina, vol. 68, p. 20; and F. W. Dafert, 

Monatsh. Chem., vol. 29,1908, p. 235.
SALINE. RESIDUES. 

Analyses of caliche.

243

NaN03 . ................

KN03 .................

NaCl. ................

CaCl2 ..................

MgCl2 . ...............

KC104 . ...............

Na,S04 . ..............

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

CaS04 ................

Na2B407 . .............

Nal..............:...

NaI03 ... .............

NH4 salts.............

Na2Cr04 . .............

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

2.07

.79

100. 00

V

c

41. 12.

3.43

3.58

.75

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

.94

3.13

4.80

.53

.07

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................................. 6NaN03 .2Na2S04 .3H20.

Lautarite..................................... CaI2Oa .

Dietzeite...................................... 7CaI20G .8CaCr04 .

The lautarite and dietzeite are remarkable as the first definitely 

known iodates to be found in the mineral kingdom, although A. A. 

Hayes 1 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 2 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 hi exceptional cases as high as 6.79 per cent of KC104 , have 

been discovered in Chilean nitrates.3 Finally, these nitrates always 

contain some borates, perceptible traces of rubidium and lithium, 

but probably no csesium,.4 The borates may be small in amount, but 

it is doubtful whether they are ever quite absent.

1 See ante, p. 237.

2 Annales chim. phys., 6th ser., vol. 11,1887,'p. 121.

a B. Sjollema, Chem. Zeitung, vol. 20/1896, 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.

«L. Dieulafait, Cornpt. Rend., vol. 98,1884, p. 1545.
244 THE DATA OF GEOCHEMISTRY.

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,1 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 2 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,3 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 deposit near Cochabamba, Bolivia.

KN03 ........................................................ 60. 70

Na2B407 ....................................................... 30. 70

NaCL........................................................ trace

H20.......................................................... trace

Organic matter.................................;............... 8. 60

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,4 who assumed a marine origin for the deposits, suggested 

that their nitrogen might be derived from the decomposition of great 

masses of seaweeds; but this view has not been generally accepted. 

For example, the beds at Maricunga 5 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, 

studied by W. Newton, 6 lies between the coast range and the Andes, 

3,000 feet above the sea, and the nitrate beds have peculiarities which

1 Jour. Soc. Chem. Ind., vol. 19,1900, p. 414.

2 Berg. u. Hiittenm. Zeitung, vol. 55,1896, p. 391. Two analyses are given.

aCompt. Rend., vol. 99,1884, p. 84.

« Jour, prakt. Chemie, vol. 102,1867, p. 459.

« See E. Semper and M. Blanckenhorn, Zeitschr. prakt. Geol., 1903, p. 309.

8 Jour. Soc. Chem. Ind., vol. 19,1900, p. 408. See also an earlier paper in Geol. Mag., 1896, p. 339.
SALINE RESIDUES. 245

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, 1 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,2 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,3 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 

of Chile and Argentina carbonated waters are the exception rather 

than the rule.

Penrose,4 in his very recent study of the nitrates, favors a marine 

origin for them, on the ground that the pampa, where the nitrate

1 Annales chim. phys., Gth ser., vol. 11,1887, p. 111.

8 Annales des mines, 9th ser., vol. 5,1894, p. 50.

s Zeitschr. 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.

4 Jour. Geology, vol. 18,1910, p. 16.
246 THE DATA OF GEOCHEMISTRY.

beds 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.

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. 1 It may be 

discarded, but it should at least be thoroughly investigated.

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

i 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.
SALINE. RESIDUES. 247

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, New Mexico. 1 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.

1 See C. W. Hayes, Bull. U. S. Geol. Survey No. 315,1907, p. 215. On alunogen in Colorado see W. P. 

Headden, Proc. Colorado Sci. Soc., vol. 8,1905, p. 62; also P. Termier on the derivation of alunite from 

feldspar, Bull. Soc. Min., vol. 31,1908, p. 215; W. Cross, Seventeenth Ann. Eept. U. S. Geol. Survey, pt. 2, 

1890, p. 314, and H. W.Turner', Am. Jour. Sci., 4th ser., vol.5,1898, p.'424,have described quartz-alunite 

rocks. On alunite in ore bodies see F. L. Ransome, Econ. Geology, vol. 2,1907, p. 667. These occurrences 

are products of rock decomposition rather than residues from saline waters.
CHAPTER VIII.

VOLCANIC GASES AND SUBLIMATES. 

GASEOUS EMANATIONS.

Regardless of all speculations as to the origin of the lithosphere 

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 independently of cosmogonic hypotheses. Fluid magmas are seen to issue 

from the earth and to solidify as lavas; they may be emitted quietly 

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 our 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 commonly 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 

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 

248
VOLCANIC GASES AND SUBLIMATES. 249

restored to the hydrosphere. For instance, F. Fouque",1 observing 

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, hydrogen 

sulphide, sulphur dioxide, carbon dioxide, carbon monoxide, hydrochloric acid, chlorine, methane, hydrofluoric acid, and silicon fluoride.2 

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 further back in time 

than to the middle of the last century, when R. W. Bunsen published 

the results of his Icelandic researches.3 From among his analyses of 

volcanic gases the following examples are selected:

Analyses of volcanic gases from Iceland.

A. From a fvunarole in the great crater of Hekla.

B. From a fumarole in tlie 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.

2 . .................................. oa ...... ..............................

H2 .......... ..........................

C02 ..................................

H

C1

S02 .. ................'.................

-

A

81.81

14.21

2.44

1.54

100. 00

B

78.90

20.09

1. 01

100. 00

C

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 top small for determination.

1 See A. Geikie, Textbook of Geology, 4th ed., p. 260. I have not been able to find the original source of 

this citation.

2 The two fluorine compounds are reported by A. Scacchi from Vesuvius, Catalogb del mineral! Vesuviani, Naples, 1887. See also E. S. Dana, System of Mineralogy, 6th ed., p. 169.

a Annales chiin. phys., 3d ser., vol. 38,1853, p. 215. For these analyses and others, see pp. 260-266. An 

earlier, classical memoir by Elie de Beaumont, entitled "Emanations volcaniques et metalliferes," appeared 

in Bull. Soe. g6ol. 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.
250 THE DATA OF GEOCHEMISTRY.

Among the sublimates formed by these fumaioles, Bunsen noted 

sulphur and various metallic chlorides, especially common salt. One 

sublimate; however, contained 81.68 per cent of ammonium chloride.

Because cf 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 

fumaroles 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.

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.

At Vulcano, Deville and Leblanc made a number of striking observations, which are well illustrated by the following selected analyses:

1 Bull. Soc. geol. France, 2d ser., vol. 13,1855-56, p. 606; vol. 14,1856-57, p. 254.

2 Annales chim. phys., 3d ser., vol. 52,1858, p. 5.
VOLCANIC CASES AND SUBLIMATES. 251

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.

C02 ...................................

S02 ..................................

H8S..................................

02 . .................................. "NT

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

24.9

100.0

D

6.4

83.1

.7

9.8

100.0

E

86.0

none

14.0

100.0

These analyses show very well the progressive change in the fumaroles as they recede from the eruptive center. 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 de Xirbi. 

D. From the Macaluba de Girgenti.

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

oa ............ ................................. Xt..... .......................................

CH4 .... .......................................

A

94.70

1.10

3.52

.68

100. 00

B

90.7

1.0

3.3

5.0

100.0

C*

0.70

5.17

20.40

73.73

100. 00

D

1.15

1.70

6.75

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; the fumaroles 

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* 1 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. Rend., vol. 61,1865, pp. 210, 421, 564, 754.
252 THE DATA OF GEOCHEMISTRY.

Analyses of gases from fumaroles at different temperatures, Vulcano. 

A. Temperature above 350°. B. Temperature 250°. C. Temperature 150°.

HCH-S02 .. ............................................

C02 ...................................................

02 .....................................................

AT

,^

73.80

23.40

.52

2.28

100. 00

T5

66.00

22.00

2.40

9.60

100. 00

c

27.19

59.62

2.20

10.99

100. 00

In 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 fumaroks, Vulcano.

HC1.. .................................................

H2 S. ...................................................

C02 ...................................................

02 .:. ..................................................

N

,

D

7.3

10.7

68.8

N 2.7

11.2

a 100. 7

E

63.59

7.28

29.13

100. 00

F

17.55

77.02

.70

4.73

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. Fouqu6'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.

H,S. ......................................................

C02 .... ....................................................

02 ................ ..................... .....................

G (temperature 90°).

11.43

56.67

5.72

26.18

100. 00

H (temperature 77.5°).

none

15.09

15.51

69.40

100. 00

i See note by Deville, Compt. Rend., vol. 61,1865, p. 567. For recent analyses of gases from Italian volcanic sources, see R. Nasini, F. Anderlini, and R. Salvadori, Gazz. chim. ital., vol. 36, fasc. 1,1906, p. 429-
VOLCANIC GASES AND SUBLIMATES. 253

An elaborate examination of the gases emitted by Etna during several eruptions led 0. Silvestri* to conclusions much like those reached 

by Deville and Leblanc, 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. ..................................................

KC1.......... .........................................

Na^CCV ................................................

Na2S04 ... .............................................

H20.... ...............................................

50.19

,50

11. 12

1.13

30.76

100. 00

63.02

.27

6.49

trace

30.22

100.00

76.01

.03

2.11

.75

21.10

100. 00

In 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 walls 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. As the temperature falls they 

develop hydrogen sulphide and deposit crystals of sulphur. Second, 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.

N2 ................ .........................................

Oa ............................. .............................

CO

H e 2b.......................................................

77.28

17.27

5.00

.45

100. 00

79 07

18.97

1.61

.35

100. 00

11 fenomeni vulcanic! presentati dell' Etna, etc., Catania, 1867. Tho data here given arc from an abstract 

by G. vom Rath, Neues Jahrb., 1870, pp. 51, 257. See also the great monograph, -'Dcr Aetna," by Sartorius von Waltershausen and A. von Lasaulx, 2 vols., Leipzig, 1880.
254 THE DATA OF GEOCHEMISTRY:

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 time 

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 25,1866. 

C. Gas collected March 7,1867, 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.

H2S ..........................................

C02 ..........................................

H2 ...........................................

CH4 .........................................

O2 ........t........ ..........................

N

A

trace

36.42

29.43

.86

.32

32.97

100. 00

B

trace

50.41

16.12

2.95

.20

30.32

100. 00

C

6.22

56.70

.07

21.11

21.9,0

100. 00

none

1.94

1.00

«24. 94

72.12

100. 00

«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

1 Neues Jahrb., 1878, p. 163.

? Santorin et ses Eruptions, Paris, 1879,
VOLCANIC GASES AND SUBLIMATES. 255

contact with hot lava, although Fouque" believed that they were present 

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 on Nea Kamfini. Collected over sulphurous water, 

at temperature 56°.

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 of eruptive field, March, 1867.

E. Gas collected near the port of St. George of Nea Kam6ni, March 9,1867.

HaS. ................................

C0a ..................................

Oa . .................................

N

<&+............... ...................

A

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

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. Our list must close with three analyses by 

H. Moissan 1 of gases from West Indian fumaroles, which are interesting on account of the determinations of argon. The analyses are 

as follows:

1 Compt. Rend., vol. 135,1902, p. 1085; vol. 138,1904, p. 936. For details relative to these fumaroles and 

other volcanic emanations, see the monograph by A. Lacroix, La Montagne Pelfie et ses eruptions, Paris, 

1904. F. Fouqu6, Corupt. Rend., vol. 66,1868, p. 915, analyzed gases from a submarine eruption near the 

Azores. H. Gorceix (idem, vol. 75,1872, pp. 154, 270; vol. 78,1874, p. 1309) examined gases from Vesuvius, 

Santorin, and Nlsyros; gases from St. Paul Island were studied by C. Velain; Idem, vol. 81,1872, p. 332.
256 THE DATA OF GEOCHEMISTRY.

Analyses of gases from West Indian fumaroles.

A. From a fumarole on Mont Petee, Martinique. Gas collected by Lacroix after the great eruption of 

May, 1902. 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.

ooa ...................................................

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

CH4 .................................................

H3 .......... .......................................

02 ... ................................................

N

A. ....................................................

HC1 .........:.......................................

H2S ..................................................

S, vapor .............................................

A

15.38

1.60

5.46

8.12

13.67

54.94

.71

99.88

B

52.8

7.5

36.07

.73

2.7

99.80

C

69.5

2.7

22.32

.68

4.5

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 Pel6e emanation, which emphasizes the 

observations made by W. Libbey l on Kilauea. He, by spectroscopic 

study of the volcanic flames, found that hydrogen, carbon monoxide, 

and hydrocarbons were probably present. Hydrogen had been similarly 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.

SUBLIMATES.

It has already been remarked that the gases issuing from a volcano 

are often if not always 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; 3 others result 

from decompositions of volatile matter; and still others are generated 

by reactions between different gases. For example, sulphur may be

i Am. Jour. Sci., 3d ser., vol. 47,1894, p. 372.

sCompt. Rend., vol. 64,1867, p. 1303; vol. 97,1883, p. 601.

s For example, ammonium chloride, which when vaporized is dissociated into NHg+HCl.
VOLCANIC GASES AND SUBLIMATES. 257

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.1

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,2 to the extent of 0.17 per cent; and 

A. Cossa 3 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 4 names realgar, boric acid, sodium 

chloride, ammonium chloride,5 ferric chloride, glauberite, lithium 

sulphate, sodium sulphate, alum, 6 hieratite,7 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. Lacroix 8 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. Casoria 9 and G. Freda. 10 These salts, however, are

1 On the conditions under which different modifications of sulphur are deposited around volcanoes 

see A. Brun, Chem. Zeitung, No. 15, 1909. Bran holds that the HjS,SOsreaction does not take place in 

solfataras.

2 E. Divers and T. Shimidzu, Chem. News, vol. 48,1883, p. 284

8 Zeitschr. anorg. Chomio, vol. 17,1898, p. 205. 

< Die Aeolischen Inseln: Abhandl. Math.-phys. Classe, K. bayer. Akad., vol. 20, Abth. 1,1899, p. 193.

6 Containing, according to Deville and Leblanc (Annales chlm. phys., 3d ser., vol. 52, 1858, p. 5), also 

iodide.

8 Potash alum, containing caesium, rubidium, and thallium. A. Cossa, Atti Accad. Lincei, 1878, pt. 2, 

p. 34.

7 Potassium silicofluoride, KaSiF6 . A. Cossa,'Compt. Rend., vol. 94,1882, p. 457.

8 Compt. Rend., vol. 142,1906, p. 1249. See also H. J. Johnston-Lavis, Nature, May 31,1906. In Bull. 

Soc. Mm., vol. 30,1907, p. 219. Lacroix has described the minerals of the Vesuvian fumaroles in considerable detail.

8 Abstract in Zeitschr. Kryst. Min., vol. 41,1906, p. 276. Casoria found molybdenum, bismuth, copper 

and zinc in Vesuvian salts.

10 Gazz. chim. ital., vol. 19,1888, p. 16.

101381° Bull. 491 11 17
258 THE DATA OF GEOCHEMISTRY.

interpreted by F. Henrich 1 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, Cu 2S05 ; and cyanochroite, 

K2Cu(SO4 ) 2 .6H20; with some hydrous chlorides and oxychlorides. 

Even manganese is found in the mineral chlormanganokalite, 

K4MnCl e , discovered by H. J. Johnston-Lavis.2 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 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. Lacroix 3 among the fumarole products 

of Mont Pele'e. Sodium carbonate is also produced in a secondary 

way. Silver was discovered by J. W. MaUet 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. Lacroix 5 and F. Zambonini 6 both report galena among the substances produced during the eruption of April, 1906, and Lacroix

mentions pyrite and pyrrhotite also.

The ammonium salts found in volcanic emanations were partially 

considered in the preceding pages. They are very common, but their 

significance has been variously interpreted. Some writers have 

argued that their 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,7 in 1875, found 

silvery incrustations of an iron nitride, Fe5N3 , on an Etna lava, and

1 Zeitschr. angew. Chemie, vol. 19,1906, p. 326; vol. 20,1907, p. 179.

2 Min. Mag., vol. 15,1908, p. 54.

* Bull. Soc. min., vol. 28,1905, p. 60. Lacroix (Compt. ,Rend., vol. 144,1907, p. 1397) has recently discovered a double sulphate of potassium and lead among the fumarole products of Vesuvius. This new 

mineral is named palmierite.

« Proc. Roy. Soc., vol. 42,1887, p. 1; vol. 47,1889-90, p. 277.

5 Compt. Rend., vol. 143,1906, p. 727.

6 Idem, p. 921. In Zambonini's great monograph, Mineralogia Vesuriana, published by the Naples 

Academy in 1910, full details are given of each species found at Vesuvius, together with thorough bibliographic references. ,

7 Gazz. chim. ital., vol. 5, p. 301,1875; Pogg. Annalen, vol. 157, p. 165,1876.
VOLCANIC GASES AND SUBLIMATES. 259

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. 

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 was 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 olivine 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 sublimation 

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. Schiitzenberger 4 has observed that silica gradually loses weight in a good wind 

furnace, whose temperature is far below that of the electric arc; and

1 Ber. Deutsch. chem. Gesell., vol. 39, p. 3530,1906; Chem. Zeitung, vol. 30, p. 740,1906; Centralbl. Min., 

Geol. u. Pal., 1907, p. 161. See also R. V. Matteucci, Centralbl. Min., Geol. u. Pal., 1901, p. 45, on ammonium 

chloride in the crater of Vesuvius.

2 Natur. Wochenschr., vol. 21, p. 740,1906.

» Le four electrique, pp. 32-49, Paris, 1897. See also Compt. Rend., vol. 116,1893, p. 1222.

« Compt. Rend., vol. 116,1893, p. 1230.
260 THE DATA OP GEOCHEMISTRY.

E. Cramer i 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 

grams of quartz were evaporated. At the temperature of melting 

cast iron, quartz was stable and lost no weight; although Moissan 2 

has observed that at 1,200° silica appears to have an appreciable 

tension. According to A. L. Day and E. S. Shepherd,3 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, 4 for example, 

reports leucite, augite, hornblende, mica, sodalite, microsommite, 

cavolinite, garnet, and possibly sanidine and vesuvianite as formed 

by sublimation at Vesuvius. Furthermore, experiments recently 

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. 5 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. 6 If the more volatile substances accumulate in 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

 Zeitschr. angew. Chemie, 1892, p. 484.

t Compt. Rend., vol. 138,1904, p. 243.

8 Science, vol. 23,1906, p. 670.

4 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 or minerals by sublimation.

6 3,900° to 4,000° absolute. See C. W. Waidner and G. K. Burgess, Bull. Bureau of Standards, vol. 1, 

1904, p. 109.

«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°. 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. 261

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 

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 consider 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" 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

1 See his letters to Josiah Wedgwood, in Scientific correspondence of Joseph Priestley, edited by H. 

Carrington Bolton, New York, 1892, privately published.

s 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.

6 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.

8 Am. Jour. Sci., 3d ser., vol. 12,1876, p. 171.

' Proc. Roy. Soc., vol. 59,1895-96, p. 223.
262 THE DATA OF GEOCHEMISTRY.

of gases, containing 24.8 per cent of C02 and 75.2 per cent of hydrogen. A year later 1 Tilden published the results of his experiments 

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 rocks.

Rock.

Granite. ......................

Basalt........................

Volume 

of gas.

2.8 

6.4 

7.3 

17.8 

8.0

Composition of gas.

CO2.

23.60 

5.50

77.72 

31.62 

32.08

CO.

6.45 

2.16 

8.06 

5.36 

20.08

CH<.

3.02 

2.03 

.56 

.51 

10.00

Ni.

5.13 

1.90 

1.16 

.56 

1.61

H2.

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 2 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 hi 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

1 Chem. News, vol. 75,1897, p. 169. Proc. Roy. Soc., vol. 60,1896-97, p. 453.

2 Proc. Roy. Soc., vol. 64,1898-99, p. 130.
VOLCANIC GASES AND SUBLIMATES. 263

observed by H. Sainte-Claire Deville and L. Troost.1 The absorbed 

gas is largely given out on cooling, in the form of bubbles. Even 

solid glass, at 200° and under a pressure of 200 atmospheres, has been 

found by J. B. Hannay 2 to absorb oxygen and carbon dioxi'de. 

When the charged glass is cooled under pressure the gases are 

retained, but on 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 3 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 SiP4 .. . ...............................................

H2S. ..........................................................

coa .. ..........................................................

Hydrocarbons ................................................. TTJ

H2 . ...........................................................

A

1.33

272.6

12.3

53.05

232. 50

571. 78

B

 ff»n/-»£x

22.7

237.5

e q

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:

Gases evolved by granite heated to 300° ivith water.

H£. ..........................................................

CO^......... ...................................................

H2 . ...........................................................

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

i Compt. Rend., vol. 57,1863, p. 965.

a Chem. News, vol. 44,1881, p. 3. A. A. Campbell Swinton (Chem. 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.

s Compt. Rend., vol. 131, 1900, p. 647; vol. 132, 1901, pp. 58, 189; vol. 136, 1903, p. 16. Annales calm, 

phys., 7th ser., vol. 22, p. 97,1901.
264 THE DATA OF GEOCHEMISTBY.

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 Iherzolite. 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.

oo

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

CH4 ........ ..................

2 . .........................

Volume of gas, cubic centimeters.....................

A

14.80

trace

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

none

4.20

2.53

31.09

2.10

99.17 

2,846

E

35.71

.45

4.85

1.99

56.29

.68

99.97 

2,517

F

78.35

11.85

1.99

.01

7.34

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.

C02 .. ..........................................................

HaS. ..........................................................

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

CH4 .. ..........................................................

H2 ............................................................

N

-

First 

third.

20.19

1.28

.57

2.04

75.54

.30

99.92

Last two 

thirds.

6.13

.41

1 ft9

.80

Ql fi4

.30

100. 30

A similar variation was exhibited during the evolution of gas from 

ophite.
VOLCANIC GASES AND SUBLIMATES. 265

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

EL,. .......................................................... 36. 20

N2 , etc. . i .................................................... 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. Hiittner. 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 . Kocks 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:

At temperatures between 1,200° and 1,250°, on the other hand, the 

equation becomes 

SCO + 2H20 = 2C02 + 2H2 + CO.

In another series of experiments, Gautier 3 found that hydrogen, 

at high temperatures, reduced carbon monoxide, forming carbon

» Zeitschr. anorg. Chemie, vol. 43, 1905, p. 8.

» Compt. Kend., vol. 142, 1906, p. 1382; Bull. Soc. chim., 3d sen, vol. 35, 1906, p. 929. Gautier gives 

references to earlier literature. See also 0. Boudouard, Bull. Soc. chim.. 3d ser., vol. 25, 1901. 

« Compt. Kend., vol. 150, 1910, p. 1564.
266 THE DATA OF GEOCHEMISTRY.

dioxide, water, and either free carbon or methane.1 At 900° to 

1,000° the reaction appeared to be 

Between 1,200° and 1,220° it was 

4CO + 8H2 = 2H20 + C02 + 3CH4 .

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 emitted 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 constituent 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, Fe304 , with formation of free 

hydrogen and hydrogen sulphide. Galena, in a current of superheated steam, was partly sublimed and recrystallized as such 3 and 

partly decomposed into metallic lead and free sulphur. A little sulphate 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 

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, carbon dioxide, and the solid constituents of lavas. Many of these reac1 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 Hs. The reaction suggested is CO+3H2=CH4+H20. 

s Compt. Rend., vol. 142, 1906, p. 1465; Bull. Soc. chim., 3d ser., vol. 35, 1906, p. 934. 

s This recalls the existence, already mentioned, of galena as one of the Vesuvian sublimates. 

«Compt. Rend., vol. 143, 1906, p. 7; Bull. Soc. chim., 3d ser., vol. 35, 1906. p. 939.
VOLCANIC GASES AND SUBLIMATES. 267

tions are reversible, and they give rise to nearly all the gaseous mixtures which appear in volcanic emanations. The nitrogen of the volcanic gases Gautier, like several other authorities, attributes to the 

presence of nitrides in the lava.

In a more general memoir Gautier. 1 has summed up his views 

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 

kilometer of granite would yield 26,400,000 metric tons of water and 

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 

passes Paris in the Seine during an average flow of twelve 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 up 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

i Annales des mines, 10th ser., voi; 9,1906, p. 316. Compare F. Loewinson-Lessing (Compt. rend. VII. 

Cong. geol. internat., 1897, p. 369), who attributes volcanic gases to the absorption of sedimentary rocks 

by magmas. Clays yield water, limestones furnish COz, etc.

»Proc. Roy. Soc., vol. 60,1896-97, p. 156. See also E. Stecher, 14. Ber. Naturw. Gesell. Chemnitz, 1900; 

A. Rossel, Arch. sci. phys. nat., 4th ser., vol. 14, 1902, p. 481; and H. Lenicque, M6m. Soc. ingto. civils 

France, October, 1903, p. 346.
268 THE DATA OF GEOCHEMISTRY.

of 0. Silvestri l 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, C02 , 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 H2 and CO2 

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, and locked up in the minerals when the magma 

consolidated.

In an important 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 chloro-silicates, 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 has 

been noted at many volcanic centers.

s 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.

« 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. g6n. sci., 1910, p. 51. His complete researches have been brought together in a superb quarto, Recherches sur 1'exhalaison volcanique, 

Geneva, 1911.
VOLCANIC GASES AND SUBLIMATES. 269

Ca2Cl2SiO3, 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.

C12 ..... .......................................

HC1. .........................................

S02 ............................ ................

C02 ...... .......................................

02 .............................................

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

A

59.64

11.63

7.99

6.73

.50

4.78

8.73

100. 00

13

49.94

15.54

11.61

6.87

trace.

5.68

10.36

100. 00

c

82.04

none.

2.46

8.89

none.

6.61

100. 00

D

63.2

none.

} 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 

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 obtained 

by former investigators, Brun claims that he studied relatively fresh

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.

a The temperature of the lava at Kilauea is given by Brun as 1290°±40°. Arch. sci. phys. nat., 4th ser., 

vol. 30,1910, p. 576.
270 THE DATA OF GEOCHEMISTRY.

or "live" material, while his predecessors examined old or "dead" 

rocks, such as granites, etc. The distinction is probably valid. 1

The publication of Brun'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 subjoined

composition.

Gases from Vesuvius.

HC1. .........................................

C02 .............. .............................

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

6.68

none.

trace.

6.00

24.88

62.44

100. 00

C

0.80

0.15

.54

4.59

21.23

72.69

100. 00

D

0.66

0.02

0.02

3.68

17.86

77.76

100.00

The water in these gases may of course have been of superficial 

origin. J. Prestwich 4 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. The most 

serious objection to Brun's opinions seems to be the fact that deepseated plutonic rocks, which presumably solidified out of reach of

1 Two of Chamberlin's analyses relate to gases from fresh Vesuvian lava, of the eruption of 1906. They 

contained principally COa with much SOs, some CO and CH<, and minor amounts of Ha and Na. These 

gases bear no resemblance to those reported by Brun. On the other hand R. Beck (Monatsber. Deutsch. 

geol. Gesell., 1910, p. 240) found in gas extracted from obsidian 14.47 per cent Cla and 50.75 TTC1.

2 For Gautier's share in the controversy see Arch. sci. phys. nat., 4th ser., vol. 24,1907, p. 4C3, and Revue 

sci., 5th ser., vol. 8,1907, p. 545, and Nov. 27,1909. See also K. Sapper, Centralbl. Mm., Geol. u. Pal., 

1909, p. 609, and A. C. Lane, Tufts Coll. Studies, vol. 3,1908, p. 39. Brun'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. . .

< Proc. Roy. Soo., vol. 41,1886, p. 117.
VOLCANIC GASES AND SUBLIMATES. 271

percolating waters from above, contain micas, of which water is one 

of the essential constituents. The analcite basalts and the highly 

hydrated pitchstones 1 are also difficult to understand if the magma 

is really anhydrous.

It is of course possible that Brun's views may be sustained by 

future investigations, but at .present the work of Gautier seems to be 

more general and more conclusive. 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. 2 

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 

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 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,3 

by A. C. Lane,4 by S. Arrhenius, 5 and more recently by C. Doelter.6

> According to 0. Stutzer (Monatsber. Deulsch. geol. Qesell., 1910, p. 102) the water of pltchstone is not 

magmatic.

2 Cf. A. Daubre'e, Etudes synth6tiques de g6ologle exp6rimentale, 1879, pp. 235-241. 

8 Beitrag zur Fysik der Eruptionen, Wien, 1877. 

< Bull. Geol. Soc. America, vol. 5, 1898, p. 259. 

« Geol. Foran. Fdrhandl., vol. 22, 1900, p. 411. 

«Sitzungsb. Akad. Wien, vol. 112,1903, p. 681.
272 THE DATA OF GEOCHEMISTRY.

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. Their 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 Bruh.

It is plain that the consideration of the volcanic gases is directly 

connected with various current speculations concerning the origin 

of the earth; and whether we incline to the nebular hypothesis or to 

the planetesimal conception lately developed by T. C. Chamberlin, 

we must take them into account. Chamberlin and R. D. Salisbury* 

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 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 2 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, in which it is absorbed

i Geology, vol. 1, pp. 588-594, 602-618,1904. See also ante, Chapter II, p. 55. According to Chamberlin 

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, Arizona, cited by W. W. Atwood, Jour, 

Geology, vol. 14, p. 138,1906.

s Geol. Fo'ren. F6rhandl., vol. 22, p. 411,1900.
VOLCANIC GASES AND SUBLIMATES. 273 

i

much as ordinary water is taken up by calcium chloride. 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 in 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 Daubre"e 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 

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 tunes 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,

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, Sltzungsb. Akad. 

Wlen, vol. 75,1877, pp. 170-174.

a See, for example, L. Troost and P. Hautefeuille, Compt. Rend., vol. 76,1873, p. 562; L. Callletet, 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.

a 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., 3d ser., 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. clt.

< Proc. Roy. Soc., vol. 64,1898-99, p. 130.

101381° Bull. 491 11 18
274 THE DATA OF GEOCHEMISTRY.

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,1 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 

from meteorites has been well developed by G. Tschermak, 2 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,3 and they are 

expelled in great measure during solidification. They are, moreover, 

expelled explosively, a fact which can be verified in any laboratory;

1 Ann. Chem. Pharm., vol. 163,1872, p. 2oO. A similar observation by M. Berthelot Is recorded by A. 

Daubre"e, Compt. Rend., vol. 74,1872, p. 1541.

* Sitzungsb. Akad. Wien, vol. 75,1877, p. 151.

8 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.
VOLCANIC GASES AND SUBLIMATES. 275

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 surface 

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, 1 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 retardsi the cooling of its 

surrounding matter. One gram of hydrogen, burning to form water, 

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.2

Second. The hydrogen burns to form more water vapor, and the 

carbon gases oxidize to carbon dioxide. From the sulphur, sulphur

i Monatsber. K. preuss. Akad., 1878, p. 558.

8 If Brun's views should be maintained this list will need to be materially modified.
276 THE DATA OF GEOCHEMISTRY.

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 

get 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 

reaction 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.
CHAPTER IX.

THE MOLTEN MAGMA.

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 

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, 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 thermo-couple 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, Phil. Mag., 

5th ser., vol. 47, p. 66; C. E. Stromeyer, Mem. Manchester Lit. Phil. 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.

8 For estimates of temperatures far within the earth, see Clarence King, Am. Jour. Sci., 3d ser., vol. 45, 

1893, p. 7; 0. 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 based upon very doubtful extrapolations. 

It is conceivable that the increase of temperature with depth may reach a limit which it can not exceed.

s See, for example, A. Schertel and T. Erhard, Beiblatter, 1879, p. 347; and Schertel, Idem, 1880, p. 542.

277
278 THE DATA OP GEOCHEMISTBY.

placed high-temperature pyrometry upon a new footing and have 

made practicable the class of determinations which we now require..

In 1891 J. Joly 1 described an instrument (the meldometer) by 

means of which the melting points of minerals could be rapildly 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, in 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 

minerals were fused in a gas furnace; later an electric furnace was 

employed.

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 

artificial minerals, and with thermoelectric couples which had been 

calibrated by comparison with the standards at the Physikalische

1 Proc. Roy. Irish. Acad., 3d ser., vol. 2, p. 1891, 38.

a Idem, vol. 4,1896; p. 399.

s 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.

* 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, Phil. Mag., 5th ser., vol. 47,1899, p. 66; 

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, p. 1905,49.

o 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.'lOO, 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. Mixtures similar to the last have also been studied by R. Rieke, Chem. Abst., vol. 2, 

1908, p. 985, from Stahl and Eisen, vol. 28.
THE MOLTEN MAGMA. 279

Reichsanstalt at Berlin. In these measurements the melting points 

were determined by noting the exact temperatures at which abrupt 

absorptions of heat occurred, and in that way errors of judgment 

were avoided.

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.

Melting points (°C.) of various minerals, as determined by different investigators. 

Feldspars and feldspatholds.

Mineral.

Anorthite, natural. . ....

Anorthite, artificial.. . . .

Labradorite............

Andesine. .............

AritAb.j, artificial. ......

Oligoclase.............

Albite.. ...............

Orthoclase.... .........

Leucite................

Nepheline.............

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, 04(HL, 2'i6

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

« 1, 340

o Approximate. Viscosity prevents exact measurements. 

Miscellaneous minerals.

Mineral.

Enstatite. ......................

MgSi03 , artificial. ..............

Hornblende. ...................

Fluorite........................

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

Day et al.

1, 557

1,540

* 1, 391

1,625

d 1, 387

1,816

a 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 crlstobalite 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 

1,685°. Alumina (corundum ?) melts, according to Hempel, at 1,880°, magnesia at 2,250°, and lime at 

1,900°. O. Boudouard (Jour. loon and Steel Inst.. 1905. pt. 1, p. 350) puts the melting point of silica at 

1,830°. According to P. D. Quensel (Centralbl. Min., Geol. u. Pal., 1906, pp. 657, 728), tridymite melts 

as low as 1,560°, and shows incipient fusion at 1,500°.

d Private communication from A. L. Day; determined on the natural mineral.
280 THE 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 semi-fluid 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°; FeSi03 , 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 into 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 

formation of minerals when a molten lava cools, although here again 

the data should be handled with great caution. A comparison of the

' Zeitschr. anorg. Chemie, vol. 55,1907, p. 159.

2 Idem, vol. 69,1911, p. 273.

s For a reply to criticisms see Day and Sosman, Am. Jour. Scl., 4th ser., vol. 31,1911, p. 341.
THE MOLTEN MAGMA. 281

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.

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.

The following temperatures, observed by Doelter, 1 will serve to 

illustrate this point.

1 Mln. pet. Mitt., vol. 21, 1902, p. 23. J. A. Douglas (Quart. Jour. Geol. Soc., vol. 63, 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. Oesell., vol. 57,1905, p. 201 (Monatsber.); 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.
282 THE DATA OF GEOCHEMISTRY. 

Melting points (°C.) of various igneous rocks.

Rock.

Granite, Predazzo. .....................................

Monzonite, Predazzo ..................................

Lava, Etna. ...........................................

Basalt, Remagen. ......................................

Limburgite. ...........................................

Phonolite. ..............................................

Nepheline syenite. .....................................

Softens.

1, 150-1, 160

1, 115-1, 125

1, 030-1, 060

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

1,090

1, 060-1, 100

According to A. Brun, 1 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,2 based upon the presence of leucite in 

Vesuvian lava. Doelter, however, assigned to leucite a melting point 

which is certainly too low,3 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. Lava 

at Torre del Greco, says A. Geikie,4 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.

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.

i Arch. sci. phys. nat., 4th ser., vol. 13,1902, p. 307. 

» Sitzungsb. Akad. Wien, vol. 112,1903, p. 681.

' 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°. 

«Text-book of geology, 4th ed., p. 304.
THE MOLTEN MAGMA. 283

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. 1 

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 o 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 

semipermeable 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 presence of water, was found by 

Barus to fuse at about 1,250°, while the resulting pumice melted at 

1,650°, approximately.3

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

i This comparison of a volcano with a bottle of soda water or champagne has been developed by S. 

Meunief. He assumes that the water was originally occluded or combined in the rocks, and when tho 

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. 1,1902, p. 386.

»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 alkaline silicates and had been In current use for many years.

'Compare F. Quthrie, Phil. Mag., 5th ser., vol. 18,1884, p. 117, on the change from obsidian to pumice 

by extrusion of water.
284 THE DATA OF GEOCHEMISTRY.

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. 1

. 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.2

From a physico-chemical 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 convenient it may be in ordinary cases.3 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

i A good example of the resorption of olivine in 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.

3 For good summaries on magmatic differentiation, 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, 

pt. 3, 1898, p. 334; and F. Loewinson-Lessing, Compt. rend. VII. Cong. g6ol. 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. Fouque", Bull. Soc. min., vol. 25, 1902, p. 349.

3 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 solvents, 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.
THE MOLTEN MAGMA. 285

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, i 

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. ...................................... i..............

Hornblende-mica porphyry. .................................

Rhyolite. ....................................................

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 still 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. 2 What these ions are we do not vet «/ know: * but their ultimate

identification is not hopeless. The extent of the ionization is also 

unknown, but its existence seems to be established. Furthermore, 

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

i Am. Jour. Sci., 3d ser., vol. 44,1892, p. 242.

8 The coexistence in certain rocks of antagonistic minerals like quartz and magnetite may be an evidence 

of dissociation. They should react to lorm 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 

therefore appear in the solid product. I offer this merely as a suggestion. H. J. Johnston-Lavis, Bull. 

Soc. beige g<5ol.,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 alumlnates from cooling magmas to dissociation.
286 THE DATA OF GEOCHEMISTRY.

melting point of its constituent minerals, and sometimes lower than 

the lowest among the latter. Doelter's figures, as cited on page 282, 

serve to illustrate this point, although the depression is not so marked 

as in the more familiar cases just mentioned. .The experiments by 

Michaela Vudnik 1 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 CaSi03 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

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 crystalline aggregate. Take for example a solution of common 

salt in water, which freezes at 22° C. with a definite proportion 

1 Centralbl. Min., Geol. u. Pal., 1904, pp. 295, 340, 364.

2 Idem, pp. 705, 739.

sZeitschr. anorg. Chemie, vol. 35,1903, p. 187.

< 1,540° according to Alien and White. See table of melting points, p. 279;

«A similar study of several binary mixtures of silicates is reported by R. C. Wallace, Zeitscbr. 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. 287

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 

Nad to 76.4 H20. 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 fused 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 anortliite, for example, 

crystallize together in all proportions, and the melting points of the 

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 groundrnass, 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

' F. Guthrie regarded these saline mixtures with water as definite compounds, which he termedcryohydrates. See Phil. Mag., 4th ser., vol. 49,1875, pp. 1,206,266; 5th ser., vol. 17,1884, p. 462. See also M. Roloff, 

Zeitschr. physikal. Chemie, vol. 17,1895, p. 325.
288 THE DATA OF GEOCHEMISTRY.

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 composition. This is not far from the molecular ratio 3AlKSi308 : 5SiO2 , 

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 olivine. 

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 orthoclasequartz ratio as given above. It is, however, a grave question

1 Technology Quart., vol. 13,1900, p. 41.

2 Am. Jour. Sci., 4th ser., vol. 22,1906, p. 265.

3 Phil. Mag., 4th ser., vol. 49,1875, p. 20.

« British Petrography, 1888, pp. 395-419.

6 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. Bygdfin, 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. 289

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. Fluidal 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 are 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 

attempt to apply modern physicochemical methods to the investigation 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 diffii Jour. Geology, vol. 18,1910, p. 297. Also, more in detail, in Bull. U. S. Geol. Survey No. 445,1911. 

a For the conditions under which quartz can form see the section on that mineral in the following chapter, 

s Monatsh. Chemie, vol. 28,1907, p. 1313; Sitzungsb. Akad. Wien, vol. 117,1908, pt. 1; Zeitschr. Elektrochemie, 1908, p. 552.

101381° Bull. 491 11 19
290 THE DATA OF GEOCHEMISTRY.

culties that confront us here are well pointed out by Roozeboom * in 

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 

depth undergoes a change of pressure, which modifies the relative 

solubility of its components and alters the position of the eutectic 

point.

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 

anything more complex than a four-component system is likely 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 tocrystallize. Their order of deposition will then depend upon three

iH. W. Bakhuis Roozeboom, Die heterogenen Gleichgewichte vom Standpunkte 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.. Bead (E'eon. 

Geology, vol. 1,1905, p. 101) has discussed the application of the phase rule to the- study of magmas, foul; 

his suggestions have been criticized by A. L. Day and E. S. Shepherd (idem, p. 286). C. Doelter (MAft, 

pet. Mitt., vol. 25,1907, p. 79) has studied what he calls the "stability fields" of certain minejals^
THE MOLTEN MAGMA. 291

essential conditions namely, their relative abundance/ their solubility in the eutectic, and their points of fusion. Other things being 

equal, the less soluble and less fusible sunstances 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 case 

of 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 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. 

Lenar6ic,4 M. Vucnik 5 and B. Vukits 6 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

. i F. Loewinson-Lessing (Compt. rend. VII. Cong. geol. internat., 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 law of mass action; or, in other words, that law will determine 

what silicates can form. Its detailed application, however, is perhaps not practicable.

"Die Silikatschmelzlosungen, pt. 1,1903, pp. 96-101.

s Min. pet. Mitt., vol. 18,1888-89, pp. 56, 57.

<Centralbl. Min., Geol. u. Pal., 1903, pp. 705, 743.

6 Idem, 1904, pp. 295,340, 364; 1906, p. 132.

6 Idem, 1904, pp. 705, 739. See also memoirs by B. K. Schmutz, Neues Jahrb., 1897, pt. 2, p. 124; K. 

Bauer, idem, Beil. Bd. 12, p. 535,1899; K. Petrasch, idem, Beil. Bd. 17, p. 498, 1903; H. H. Keiter, 

idem, Beil. Bd. 22, p. 183, 1906; R. Freis, idem, Beil. Bd. 23, p. 43,1907; V. Poschl.Centralbl.Min., 

.Geol. u. Pal., 1906, p. 571; Min. pet. Mitt., vol. 26,1908, p. 412; H. Schleimer, Neues Jahrb., 1908, vol. 2, 

p. l; M. Urbas, idem, Beil. Bd., vol. 25,1908, p. 261; M. Hauke, idem, 1910, p'. 1; Vera Hammerle, idem, 

Beil. Bd., vol. 29,1910, p. 719; and H. Andesner, idem, Beil. Bd., vol. 30,1910, p. 467.
292 THE DATA OF GEOCHEMISTRY.

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. 1 Still we may assume that olivine, 

Mg2Si04 , and enstatite, MgSi03, have magnesium ions in common, 

and with them the rule ought to work. Each should be less soluble 

in presence of the other than it is when present alone, 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, 2 namely, ores and oxides first, then 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 fusibility, 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

1 For a discussion of this subject in greater detail see J. H. L. Vogt, Min. pet. Mitt., vol. 27,1908, p. 133.

2 Neues Jahrb., 1882, pt. 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. 293

olivine may be due either to their relative infusibility, to their insolubility in the remainder of the magma, or, as Doelter 1 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

DIFFEKENTIATION.

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 

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 

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 

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, 

but its application to observed phenomena is quite the reverse. With 

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

1 Sitzungsb. Akad. 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.

a The importance of discriminating between the fusibility of a mineral and its solubility in a magma 

is strongly emphasized by A. Lagorio, in Zeitschr. Eryst. 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 sorvent action ceases. On viscosity as related to chemical composition in silicate fusions see 

E. Greiner, Inaug. Diss., Jena, 1907
294 THE DATA OF GEOC'HEMISTBY.

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 assumption 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 4 have done full justice to this side of the question. We need 

only take up broadly the hypotheses which have been suggested in 

order 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. Lagorio,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 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 8 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 7 

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, hi 

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

1 Barker, 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.

2 Bull. Philos. Soc. Washington, vol. 12,1892, p. 89. 

s Die Eruptivgesteine des Kristianiagebietes, pt. 3, 1898, pp. 276 et seq. 

* Compt. rend. VII. Cong. g6ol. internat., 1897, p. 308.

5 Min. pet. Mitt., vol. 8,1887, p. 421. This memoir is rich in-references to former literature, 

s Am. Jour. Sci., 4th ser., vol. 3,1897, p. 21.

7 Jour. Geology, vol. 1, 1893, p. 773. See also F. Loewinson-Lessing, Compt. rend. VII. Cong. geol. 

internat;, 1897, p. 390.
THE MOLTEN MAGMA. 295

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. The 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 entirely, leaving a local enrichment in lime salts as evidence of their 

former nature.1 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 

effectiveness is by no means universally admitted. R. A. Daly,2 a 

recent advocate of the assimilation theory, has sought to explain the 

mechanism of igneous intrusions by a process which he calls "magmatic stoping." 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 L6vy 3 that differentiation 

is brought about chiefly by a circulation at high temperatures and

1 See, for example, H. J. Johnston-Lavis, The ejected blocks of Monte Somma: Trans. Edinburgh Geo 

Soc., vol. 6,1892-93, p. 314. Also a paper in Natural Science, vol. 4,1894, p. 134. F. 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, 

pt. 1, p. 18), who operated on olivine, pyroxene, hornblende, biotite, feldspars, quartz, garnet, iolite, and 

zircon in 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.

8 Am. Jour. Sci., 4th ser., vol 15,190?, p. 269; vol. 16,1903, p. 107; vol. 20,1905, p. 185; vol. 20,1908, p. 17, 

and in the Rosenbusch " Festschrift," 1906, p. 203. Sec also Bull. U. S. Geol. Survey No. 209,1903, p. 104, 

on the rocks of Mount Ascutney. A discussion of Daly'c 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 Silikatschmelzlosungen, pt. 2, 1904, p. 225) regards the assimilation theory as quito 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. G, 1906,, p. 126; and A. P. Coleman, Jour. Geology, vol. 15,1907, p. 773.

»Bull. Soc. gfiol. France, 3d ser., vol. 25,1897, p. 367.
296 THE DATA OF GEOCHEMISTRY.

under great pressures 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, 1 

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 Michel 

LeVy's process would imply. In the Yellowstone Park, according to 

J. P. Iddings,2 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 

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 magmatic mass and to diminish its viscosity, thereby 

facilitating crystallization.

In a later paper than that previously cited G. F. Becker 3 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 lava. 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

1 The ancient volcanoes of Great Britain, vol. 2,1897, p. 477.

2 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.

a Am. Jour. Sci., 4th ser., vol. 4,1897, p. 257.
THE MOLTEN MAGMA. 297

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 l 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 Adirondack? from the lighter rocks of the same 

magmatic mass,2 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, LoewinsonLessing 3 has shown that in certain Vesuvian lavas leucite crystals' 

have risen to the top, while augite sank to the bottom.4 In the differentiation of the eruptive iron ores of Norway, as described by J. H. 

L. Vogt,5 the same process may operate, although Vogt gave another 

interpretation to the phenomena. In cases of this land the liquation 

hypothesis of J. Durocher 6 may be partly applicable, and we can easily 

Qonceive of the cooling magma as separating into lighter and heavier 

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,7 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

1 Bull. U. S. Geol. Survey No. 237,1905, p. 1S3. Compare also A. Barker, Quart. Jour. Geol. Soc., vol. 50, 

1894, p. 324; and T. L. Walker, Am. Jour. Sci., 4th sen, vol. 6, 1898, p. 410. 

3 See J. F. Kemp, Nineteenth Ann. Kept. U. S. Geol. Survey, pt. 3,1899, p. 417.

3 Studien ueber die Eruptivgesteine, St. Petersburg, 1899, p. 155.

4 Similar observations are recorded by much earlier workers, as, for instance, Charles Darwin, in Geo 

logical observations on volcanic islands, 1844, p. 117, and P. Scrope in his treatise Volcanos, 1872, p. 125. 

6 See summary by J. J. H. Teall in Geol. Mag., 1892, p. 82. 

8 Annalea des mines, 5th ser., vol. 11,1857, p. 217, 

' Min. pet. Mitt., vol. 18,1888-89, p. 233.
298 THE DATA OF GEOCHEMISTRY.

Schweig, 1 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 liquor 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, and 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 composition 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 2 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 a eutectic mixture, 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 some reference to recent 

speculations and investigations relative to the sources of volcanic 

heat. That heat, hitherto, has been commonly referred either tp the 

molten matter left over after the consolidation of the lithosphere, or 

to a generation from mechanical sources, such as pressure and the

i Neues Jahrb., Beil. Bd. 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.

a The sudden expansion of the gases released at the beginning of a volcanic eruption must exert a noteworthy cooling effect on the residual magma.
THE MOLTEN MAGMA, 299

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.1

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. Laborde........

E. Rutherford and II. T. Barnes.. 

C. Runge and J. Precht..........

F. Paschen.....................

J. Precht.......................

E. v. Schweidler and V. F. Hess. 

W. Duane.......................

W. Duane.......................

Compt. Rend., vol. 136, 1903, p.

673. 

Phil. Mag., 6th ser., vol. 7, 1904,

p. 202. 

Jour. Chem. Soc., vol. 86 (2), 1904,

p. 7. 

Physikal. Zeitschr., 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 ser., vol. 31,

1911, p. 247.

100 approx.

100 approx.

105.

12G.

134.4

118.

120.

104 to 117.

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,2 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, and 

polonium are also known, but their 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

1 A discussion of the purely physical or mechanical sources of heat does not fall within the scope of this 

treatise.

2 The most probable value is 118 cal.
300 THE DATA OF GEOCHEMISTRY.

is, as yet, only an unproved speculation.1 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 2 and the atmosphere, but is most marked in the older rocks, and it is mainly attributed to the wide-spread 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 recently been 

given, is a gas belonging to the helium-argon group. By decomposing 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.3 From Strutt's meas1 N. R. Campbell (Phil. 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.

2 The radioactivity of many spring waters 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 (Phil. 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 minerals.

3 See Radioactivity and geology, already cited. For Strutt'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, Phil. 

Mag., 6th ser., vol 14, 1907, p. 231. These authors also measured the radioactivity of various rocks near 

Montreal. See also memoirs by C. C. Farr and D. C. H. Florance, Phil. Mag., 6th ser., vol. 18,1909, p. 812; 

A. L. Fletcher, idem, vol. 20,1910, p. 36; vol. 21,1911, pp. 102, 770; A. Gockel, Jour. Chem. Soc., vol. 100, 

pt. 2,1911, p. 174, abstract; and E. H. Buchner, idem, p. 243, abstract. Recent papers by Joly, partly upon 

radium and partly upon thorium, are in Phil. Mag., 6th ser., vol. 17,1909, p. 760; vol. 18,1909, pp. 140,577; 

vol. 20.1910, pp. 125,353. 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, 0. 

Scarpa, Atti 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 (Phil. 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. 148.
THE MOLTEN MAGMA. 301

urements, as corrected by Eve and H&clntosh, 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 l.lXlO"12 

grams per gram, the mean of the two averages being 1.4xlO~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,1 

the mean radium content of igneous rocks is 5.5X10"12 grams per 

gram, and that of sedimentary rocks 4.3 X 10~12 . 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.2 

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.3 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.

On the purely qualitative side of the problem more can be said. 

It is proved that the surface rocks of the earth contain diffused radium, and that must be emitting heat at a definite rate. On this 

basis of fact Major C. E. Dutton4 has suggested that volcanic heat 

may be developed by radioactivity in limited tracts from 1 to 3 and

1 Radioactivity and geology, p. 275.

"G. von dem Borne (Zeitschr. Deutsch. geol. Gesell., vol. 58, 1906, p. 1) has found the granite of the 

Erzgebirge to be strongly radioactive.

8 See also C. Liebenow, Physikal. Zeitschr., vol. 5,1904, p. 625. 

« Jour. Geology, vol. 14,1906, p. 259.
302 THE DATA OF GEOCHEMISTRY.

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 Dutton explains the periodicity of eruptions, and he 

argues that no permanent reservoirs of molten magma are required 

in order to account for volcanic phenomena. Dutton's views have 

been opposed by G. D. Louderback,1 partly on geologic grounds, and 

partly because radiferous minerals, such as uraninite, are not found 

among volcanic products. On the other hand Joly 2 is inclined to 

favor Dutton'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.

In 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 3 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 helium 4 and probably 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.5 Given the amount of uranium or 

radium in a rock or mineral, and also the amount of helium which it

1 Jour. Geology, vol. 14,1906, p. 747.

2 Phil. 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. 60,1908, p. 431.

3 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. 148, 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 ha erbium. R. J. Strutt (Proc. Roy. Soc., 

vol. 81A, 1908, p. 278) suggests that the helium in the Stassfurt salts may be derived from potassium.

* According to F. Soddy (Phil. Mag., 6ta sen, vol. 16,1908, p. 513) uranium and thorium both yield helium.

6 See E. Rutherford, Radioactive transformations, p. 187. For applications of the method, see R. J. 

Strutt, Proc. 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. Becker, Bull. 

Geol. Soc. America, vol. 19,1908, p. 113; J. Joly, Radioactivity and geology, chapter 11; J. Koenigsberger, 

Geol. Rundschau, vol. 1,1910, p. 245; and A. Holmes, Proc. Roy. Soc., vol. 85A, 1911, p. 248.
THE MOLTEN MAGMA. 303

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.

Assuming that lead is the final product of the degradation of 

uranium, B. B. Boltwood 1 has sought to determine the age of certain minerals from the ratio between the two metals when both 

are present. The ratio multiplied by 10 10 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,2 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.

Mackintoshite (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 Rutherford, and yet the figures vary enormously, even for a single species. 

The assumption that lead is derived from uranium may be correct; 

but that all the lead in a given mineral had that origin is most doubtful. In the evolution of the chemical elements lead probably existed 

before uranium, and, being more stable, was developed in larger 

quantities. Magmatic lead, as represented by galena, is common 

in pegmatites, and may easily have become entangled with other

1 Am. Jour. Sci., 4th ser., vol. 23,1907, p. 86.

2 Bull. Geol. Soc. America, vol. 19,1.9.Q8,g.1.34%
304 THE DATA OF GEOCHEMISTRY.

minerals as an occluded impurity when crystallization first took 

place. This possibility is pointed out by Becker very clearly. 

The uranium-lead ratio is of very questionable value in computing the age of minerals.

Similar objections apply to the use of the helium-radium ratio, 

when it is assumed that all the helium was generated by radioactive 

decay. Helium is found in the nebulae, the hotter stars, and the sun; 

and the sun contains lead also; but uranium, thorium, and radium 

have not yet been recognized in the solar spectrum. Primordial 

helium, therefore, 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. An 

alternative hypothesis is suggested by certain beryls in which Strutt 2 

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. The assumption of primordial 

helium is, however, more probable, or at least less speculative. 

A. Piutti 3 has 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.4 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,5 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.

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. 6 

The high values found by radioactive measurements are therefore to 

be suspected until the discrepancies shall have been explained. 7

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.

2 Proc. Hoy. Soc., vol. 80 A, 1908, p. 572.

' Jour. Chem. Soc., vol. 100, pt. 2,1911, p. 88 (abstract).

< See A. Jaquerod and F. L. Perrot, Compt. Rend., vol. 139,1904, p. 789; vol. 144,1907, p. 135.

B Compt. Rend., vol. 148,1909, p. 1451; vol. 149,1909, p. 267.

8 See G. F. Becker, Smithsonian Misc. Coll., vol. 56, No. 6,1910.

7 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 Traits de radioactivit6,2 vols. Paris, 1910, is also most important. In 

Zeitschr. Elektrochemie, vol. 13, 1907, pp. 369-406, is a series of papers forming a symposium upon the 

subject.
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 tranformations 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 

101381° Bull. 491 11 20 305
306 THE DATA OF GEOCHEMISTRY.

implications; and each reported case of alteration, therefore, should 

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, ilmeiiite, 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°.
BOCK-FOEMING MINERALS. 307

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 

K. 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 Ettinger 8 

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 recent conclusions of 

Moissan, 11 who finds that when carbon is raised to a high temperature 

at atmospheric pressure it volatilizes without fusion and on cooling

1 Compt. Rend., vol. 135,1902, p. 921.

2 Proc. Roy. Soc. Edinburgh, vol. 11, 1880-81, p. 20. K. Chrustchofl (Zeitschr. anorg. Chemie, vol. 4, 

1893, p. 472) also obtained diamonds from solution in silver. Molten silver, he says, can dissolve about G 

per cent of carbon.

s Proc. Roy. Soc., vol. 30,1880, pp. 188, 450.

< Compt. Rend., vol. 116,1893, p. 218. Also C. Friedel, idem, p. 224. See also Q. Majorana, Atti Accad. 

Lincei, 5th ser., vol. 6, pt. 2,1897, p. 141.

5 Abstract in Geol. Mag., 1898, p. 226.

a Monatsh. Chemie, vol. 23,1902, p. 817.

' Sitzungsb. Akad. Wien, vol. 112, 1903, p. 507.

s Chem. Centralbl., 1896, pt. 2, p. 573. From Stahl u. Eisen, vol. 16, p. 585.

<> Chein. Zeitung, vol. 25, 1901, p. 979.

1° Zeitschr. Elektrochemie, vol. 8,1902, p. 273.

u 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. Flelssner, Oesterr. 

Zeitschr. Berg- u. Hiittenwesen, vol. 58,1910, pp. 521,539,550,570. See also P. Neumann, Zeitschr. Elektrochemie, vol. 15, 1909, p. 817.
308 THE DATA OF GEOCHEMISTRY.

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. 

Finally, 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.

In nature the diamond is ordinarily found 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,4 and Carcote, Chile, 5 and the meteoric iron of Canyon Diablo.6 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 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.7 The volcanic character of this matrix or "blue ground" 

was early recognized, and several authorities, notably the late H. 

Carvill Lewis,8 have ascribed the origin of the diamonds to the sol1 Compt. Rend., vol. 117,1893, p. 164.

2 Nature, vol. 72,1905, p. 397.

3 Proc! Boy. Soc., vol. 76 A, 1905, p. 458.

* M. Erofe'ef and P. Latschinofi, Jour. Russ. Chem. Soc., vol. 20,1888, p. 185. Abstract in Jour.Chein. 

Soc., vol. 56,1889, p. 224.

6 W. Will and J. Pinnow, Ber. Deutsch. chem. Gesell., vol. 23,1890, p. 345.

6 G. A. Koenig and A. E. Foote, Am. Jour. Sci., 3d ser., vol. 42,1891, p. 413.

i See E. Cohen, 5. Jahresber. Ver. Erdkunde, Metz, 1882, p. 129.

s 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 New York, 1909; and P. A. 

Wagner, Die diamantfuhrenden Gesteine Sudafrikas, Berlin, 1909. For bibliographic notes on diamond 

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. Met., vol. 17,1908, p. 277; and F. W. Voit/Eng. and Min. Jour.,vol. 

87,1909, p. 789.
BOCK-FORMING MINERALS. 309

vent 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 1 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,2 however, has sought to prove that 

the true matrix of the Cape diamond is eclogite, from which he 

says the mineral has crystallized as an original constituent, just as 

zircon crystallizes from granite. The very ultimate association of 

these diamonds with garnet lends support to this view. On the 

other hand, G. F. Williams 3 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 

apophyllite. If the diagnosis was correct, it throws doubt upon the 

igneous origin of the gem, for apophyllite is a highly hydrous mineral. 

According to H. S. Harger 4 the Vaal River diamonds are derived 

from andesitic lava, and H. Merensky 5 reports them in pegmatite and 

diabase. The diamonds recently discovered in Arkansas, however, 

are associated with a peridotitic rock closely resembling kimberlite.6 

In Brazil diamonds are associated with hydromica schists and the 

peculiar form of qu artzite known as itacolumite; and 0. A. Derby 7 

finds no evidence of olivine rocks anywhere in the diamond-bearing 

region. Similar conclusions have been reached by J. C. Branner.8 

Furthermore, near Bellary, Madras Presidency, India, M. Chaper 9 

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 10 found diamonds in a matrix

1 Ber. Deutsch. chem. Gesell., vol. 25,1892, p. 2470.

3 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 the 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.

8 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 J. R. Sutton, Nature, vol. 75,1907, p. 488.

« Trans. Geol. Soc. South Africa, vol. 12,1910, p. 139. See also E. H. V. Melvill, idem, p. 205, on stones 

from the Roberts-Victor mine.

6 Zeitschr. prakt. Geologie, 1908, p. 155.

e See G. F. Kunz and H. S. Washington, Am. Jour. Sci., 4th ser., vol. 24,1907, p. 275.

7 Am. Jour. Sci., 3d ser., vol. 24,1882, p. 34; Jour. Geology, vol. 6,1898, 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 Hiissak, the minerals of the Brazilian diamond sands are those 

derived from granites, gneisses, and older schists, such as amphibolite. An important earlier paper upon 

Brazilian diamonds is by C. Heusser and G. Claraz, Zeitschr. Deutsch. geol. Gesell., vol. 11,1859, p. 448.

8 Am. Jour. Sci., 4th ser., vol. 31,1911, p. 480.

9 Compt. Rend., vol. 98,1884, p. 113. More fully, in Bull. Soc. g6ol. 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. 

"> Rept. Brit. Assoc. Adv. §pi., 1906, p. 562. See also Chem. News, vol. 96,1907, p. 146. According to J. A. 

Thomson (Geol. Mag., 1909. p. 492), the matrix of the Inverell diamonds is dolerite.
310 THE DATA OF GEOCHEMISTRY.

of hornblende diabase. In short, though much evidence points to an 

igneous origin for the diamond, it is not necessary to assume that the 

same magma has yielded it in all cases.1

Graphite. Carbon, more or less impure. Bliombohedral. Atomic 

weight, 12; molecular weight probably below that of diamond. 

Specific gravity, 2.2. 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 0 . 2

Graphite is easily produced artificially and is therefore a common 

constituent of furnace slags. Here it is derived from the fuel. It is 

made on a commercial scale 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 has 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 geological 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 ° has shown that amorphous carbon can be dissolved in 

a fused potash glass containing a little calcium fluoride and rede1 An excellent monograph on the diamond, by E. Boutan, forms a volume in Fremy's Encyclopedic 

chimique, Paris, 1886. It concludes with a very full bibliography. On diamonds in California, see H. 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. 12,1906, p. 441.

a H. Moissan, Compt. Rend., vol. 135,1902, p. 921.

s Jour. Franklin Inst., vol. 147,1899, p. 475.

4 Zeitschr. anorg. Chemie, vol. 5,1894, p. 111.

6 Compt. Rend., vol. 140,1903, p. 405.

«Compt. rend. VHI. Cong. g6ol. internat., vol. 1,1900, p. 447.

7 Zeitschr. Deutsch. geol. Gesell., vol. 41,1889, p. 359. For a full account of the Ceylon graphite see A. K. 

Coomara-Swamy, Quart. Jour. Geol. Soc., vol. 56,1900, p. 609. This paper contains a valuable bibliography, 

s Jahrb. K.-k. geol. Reichsanstalt, Wien, vol. 48,1898, p. 274. 

»Ber. Deutsch. chem. Gesell., vol. 24,1891, p. 4093. Zeitschr. Naturwissenschaften, vol. 64,1891, p. 224.
BOCK-FORMING MINERALS. 311

posited as graphite. In other words, graphite can form 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 solution 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.

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 mica. 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. B as tin 3 to the dynamic metamorphism of carbonaceous sediments. T. H. Holland,4 however, has described an elseolite syenite 

from India in which graphite appears to be an original mineral; and 

Moissan 5 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.6 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.

Minute grams of jiative iron are not uncommon in certain eruptive 

rocks, especially in basalts. They were first identified by T. Andrews 7 in the basalt of Antrim, Ireland. More recently they have

1 Neues Jaarb., 1901, vol. 2, ref., p. 74.

2 Compt. rend. VIII. Gong. g6ol. internat., vol. 1,1900, p. 447.

»Econ. Geology, vol. 5,1910, p. 134.

<-Mem. Geol. Survey India, vol. 30,1901, p. 201.

6 Compt. Kend., vol. 121,1895, p. 538.

8 See K. J. V. Steenstrup, Mineralog. Mag., vol. 6,1884, p. 1; and J. Lorenzen, Idem, p. 14. Graphite 

from inclusions in basalt is also described by R. Brauns, Centralbl. Min., Geol. u. Pal., 1908, p. 97. On 

inorganic graphite from Lapland see 0. Stutzer, idem, 1907, p. 433. In Zeitschr. prakt. Geologic, 1910, 

p. 10, Stutzer has a long article on graphite deposits and their origin. See also A. N. Winchell, Econ. 

Geology, vol. 6,1911, p. 218.

' Kept. Brit. Assoc., 1852, pt. 2, p. 34.
312 THE DATA OF GEOCHEMISTRY.

been found by G. H. Cook 1 in the trap rocks of New Jersey; by 

G. W. Hawes 2 in the dolerite of Dry River, near Mount Washington, 

New Hampshire; by F. Navarro 3 in the basalt of Gerona, Spain; 

and by F. F. Hornstein 4 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.5 E. Hussak 6 

found particles of native iron in an auriferous gravel in Brazil; and 

A. Daubre"e and S. Meunier 7 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 8 in 1870, at Ovifak, Disco Island, 

Greenland. Here large masse's of iron, up to 20 tons in weight, had 

been weathered out like bowlders 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.9 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 10 graphite, amorphous ca,rbon, and grains of 

corundum were found.

This Ovifak iron is somewhat variable in composition, as the 

numerous analyses of it sho'w. 11 The following analyses by J. Lawrence Smith are enough to indicate its general character:

1 Ann. Kept. Geol. Survey New Jersey, 1874, p. 56.

2 Am. Jour. Sci., 3d ser., vol. 13,1877, p. 33. 

s Geol. Centralbl., vol. 7,1905, p. 184. 

4 Centralbl. Min., Geol. u. Pal., 1907, p. 276.

& See for example, A. Schwantke, Centralbl. Min., Geol. u. Pal., 1901, p. 65, and M. Seebach, idem, 1910, 

p. 641. » 

 Bol. Comm. geog. e geol. Sao Paulo, No. 7,1890, p. 14. 

' Compt. Rend., vol. 113,1891, p. 172. 

s Geol. Mag., 1872, pp. 460, 516.

9 There is abundant literature on this subject. See especially K. J. V. Steenstrup, Mineralog. Mag., 

vol. 6, p. 1,1884; J. Lorenzen, idem, p. 14; J. Lawrence Smith, Annales chim. phys., 5th ser., vol. 16,1879, 

p. 452; and A. Daubr6e, Etudes synthe'tiques de geologic expgrimentale, 1879, p. 555.

10 Compt. Bend., vol. 116,1893, p. 1269.

11 See the memoirs, already cited, by Nordenskiold, Lorenzen, and Smith. Also E. S. Dana, System 

of mineralogy, 6th ed., p. 28.
BOCK-FORMING MINERALS. 313

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, 6.42. 

C. Malleable nodule from dolerite. Specific gravity, 7.46. 

D. An irregular mass. Specific gravity, 6.80.

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

Fe...3..........................................

Ni.......................................... : .

Co............................................

Cu............................................

S............................. .................

P..............................................

C...... .......................................

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

M»O sio2 ............................................

Silicates. ......................................

H20...........................................

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

6.50

.79

.13

1.54

99.13

D

88.13

2.13

L07

.48

.36

.25

2.33

.08

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 Daubre"e/ 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 Daubre"e 

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 synth6tiques de g«5ologie expdrimentale, 1879, pp. 517, 574.

2 See also E. B. de Chancourtois, Bull. Soc. geol. France, vol. 29,1872, p. 210. C. Winkler (Ber. Math. phys. 

Classe, K.-silchs. Gesell. Wiss., February 5,1900) suggests that iron and nickel may have been brought up 

from below as carbonyls, Ni(CO)<, Fe(CO)5, and FeaCCO)? compounds which decompose easily, depositing 

their metals in the free state. Compare Weinschenk's suggest'on as to graphite, ante, p. 310.

3 Trans. New Zealand Inst., vol. 18,1885, p. 401.
314. THE 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 G. 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 peridotite. 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, Skey. B. Josephinite, Melville. C. Josephinite, Jamieson. D. Del Norte County, Jamieson. E. Souesite, Hoffmann. F. Piedmont. Analyzed for Sella by Mattirolo.

Ni....... ....................

Co...........................

Pe........... .................

FeySg................... ......

s.................... .........

Cu....... ....................

As...........................

P.............................

Si02 ..................:......

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

HaOatlOO°..................

H2O above 100°. . .............

01............................

C0a ......... .................

A

67.63

.70

31.02

.22

.43

100. 00

B

60.45

.55

23.22

.55

.50

.23

.12

12.26

.81

1.12

.04

.70

100. 55

C

68.61

1.07

19.21

.05

.59

.04

.10

9.45

. .50

99.62

D

68.46

1.07

IS Q7

AC

.56

.04

10

9.97

.44

99.75

E

75.50

22.02

V 90

1.16

99.88

F

7c o

26.6

101.8

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 com1 Quart. Jour. Geol. Soc., vol. 46,1890, p. 619.

2 Bull. U. S. Geol. Survey No. 113,1893, p. 54.

sCompt. Rend., vol. 112,1891, p. 171.

4 Am. Jour. Sci., 4th ser., vol. 19,1905, p. 319.

B Idem, p. 413. Jamieson urges that 'i;he original name awaruite should be used for all these irons.
EOCK-FOEMING MINEEALS. 315

pared. 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, * masses of iron can be picked up in this locality which 

weigh from 15 to 20 pounds. 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 from 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 magmatic irons described in the preceding pages.

Analyses of native iron of secondary origin.

A. From St. Josephs Island, Hoffmann. Specific gravity, 6.8612.

B. From Cameron Township, Ontario. Analysis by Johnston for Hoffmann. Specific gravity,7.257.

C. From Cameron, Missouri, Alien.

D. From Weaubleau, Missouri, Alien,

E. From Holden, Missouri, Alien.

Fe.......... ..........................

Ni...................................

Co...................................

Mn...................................

Cu...................................

s.....................................

P.....................................

c. ...................................

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

A

88.00

.10

.21

.51

.09

.12

.96

(?)

9.76

99.75

B

90.45

.75

none

undet.

undet.

7.26

98.46

C

99.16

.207

.065

.37

99. 802

D

99.39

undet.

.13

.31

99.83

E

97. 10

undet.

.176

1.65

98. 926

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. 5 W. Moricke 6 has found pri1 Am. Jour. Sci., 3d ser., vol. 33,1887, p. 73.

2 Trans. Roy. Soc. Canada, vol. 8, pt. 3,1890, p. 39.

s Ann. Rept. Geol. Survey Canada, vol. 6,1895, p. 23 R.

< Am. Jour. Sci., 4th ser., vol. 4, 1897, p. 99. Other occurrences of naturally reduced iron are reported 

by A. A. Inostranzeff, Geol. Zent., 1908, p.,611, from Russian Island near Vladivostok, and by E. Pfiwosnik, 

Oesterr. Zeitschr. Berg- u. Hiittenwesen, vol. 58,1910, p. 327, from Shotley Bridge, England.

6 See J. F. Kemp, Bull. U. S. Geol. Survey No. 193,1902, for a complete summary of our knowledge concerning native platinum, with many bibliographic references.

o Min. pet. Mitt., vol. 12,1891, p. 195.
316 THE DATA OF GEOCHEMISTRY.

mary gold in a pitchstone from Guanaco, Chile, and G. P. Merrill* 

has described a granite from Sonora in which it also appears. Still 

other examples are cited by R. Beck. 2 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.

PyrrJiotite. Hexagonal. 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. 3

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,4 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 5 produced crystals which appeared to be identical with 

troilite. Troilite was also formed by R. Lorenz, 6 who heated iron 

to redness in a stream of H2S. C. Doelter, 7 on the other hand, by 

the same reaction, and also with amorphous ferric oxide or hematite 

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.

1 Am. Jour. Sci., 4th ser., vol. 1, 1896, p. 309.

2 Lehre von den Erzlagerstatten, 2d ed., 1903. See also W. H. Weed, Eng. and Min. Jour., vol. 77,1904, 

p. 440; and R. W. Brock, idem, p. 511.

s See S. Meunier, Annales chim. phys., 4th ser., vol. 17,1869, p. 36; and G. Linck, Ber. Deutscll. chem. 

Gesell., vol. 32, 1899, p. 895.

< Compt. Rend., vol. 32,1851, p. 823.

6 Idem, vol. 66,1868, p. 1257.

6 Ber. Deutsch. chem. Gesell., vol. 24,1891, p. 1504.

' Zeitschr. Kryst. Min., vol. 11,1886, p. 30.
\

KOCK-FORMING MINEEALS. 317

Metallic sulphides, fairly crystallized, can also be formed in the 

wet way, when appropriate mixtures are heated together in sealed 

tubes. H. de Senarmont 1 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, and J. L. Crenshaw ° report 

that pyrrhotite is formed by the direct union of iron and sulphur at 

about 700°, and also by the dissociation of pyrite above 500°. It is 

also produced by the action of hydrogen sulphide upon ferrous salts 

between 75° and 200°. The variation of pyrrhotite from troilite is 

probably due to the presence of sulphur in "solid solution" in the 

monosulphide. In meteorites the excess of metallic iron renders the 

formation of pure troilite possible. Pyrite, in absence of air, is stable 

to about 500°.

Each of these processes finds some equivalent in nature. Dry gases, 

wet gases, and alkaline solutions charged with hydrogen sulphide are 

capable of 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. Vogt7 

has shown that sulphides are actually soluble in silicate magmas, 

especially at the higher temperatures, and that they are among the

1 Compt. Rend., vol. 32,1851, p. 409.

2 Ann. Chem. Pharm., vol. 129, 1864, p. 350.

» Zeitschr. 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.

8 Yearbook Carnegie Inst. Washington, 1910, p. 104.

7 Die Silikatschmelzlosungen, 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. Bastin in Jour. Geology, vol. 16,1908, p. 124.
318 THE DATA OF GEOCHEMISTRY.

earliest minerals to crystallize. Certain of the pyrrhotite deposits of 

Norway he regards as the direct products of magmatic segregation.

Isomeric with pyrite is the less stable species marcasite, which, 

however, is not found in igneous rocks. It is common in sedimentary 

formations and in metalliferous veins, but its precise mode of formation in nature is not certainly known. Alien, Johnston, and Crenshaw produced it by the action of hydrogen sulphide on ferric salts at 

about 200°. At 450° it is transformed into pyrite. The two species 

probably differ in molecular arrangement, but the evidence upon 

this point is far from conclusive. Various structural formulsB 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 limonite, goethite, hematite, and sulphates of iron. 

Perfect pseudomorphs of limonite after pyrite are common.2

Several other sulphides occasionally appear as primary minerals 

in igneous rocks. Molybdenite, MoS2 , is common in granites, and 

J. F. Kemp,3 in a pegmatite dike in British Columbia, found masses 

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, pyrite, galena, and chalcopyrite.4 

Some of these occurrences and many occurrences of pyrite also are 

doubtless secondary.

FLUORIDES.

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, elseolite syenite, and the crystalline 

schists. W. C. Brogger 5 reports it, both as an early separation in 

the augite syenites of Norway, and also as a contact mineral. It 

sometimes appears as a sublimation product or as the result of the

1 See E. Weinschenk, Zeitschr. Kryst. Min., vol. 17,1890, p. 501; A. P. Brown, Proc. Am. Pbilos. Soc., vol. 

33,1894, p. 225; and H. N. Stokes, Bull. U. S. Geol. Survey No. 186,1901. Stokes describes many elaborate 

experiments upon the relative solubility of pyrite and marcasite in chemical reagents. See also G. \V. 

Plummer> Thesis, Univ. Pennsylvania, 1910.

2 For a discussion in extenso of the decomposition of pyrite, see A. A. Julien, Annals New York Acad. 

Sci., vol. 3,1886, p. 365; vol. 4,1S87, p. 125.

8 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. R. Brauns (Centralbl. Min., Geol. u. Pal., 

1908, p. 97) found molybdenite in inclusions in basalt. 0. Stutzer (Zeitschr. prakt. Geologic, 1907, p. 371) 

has described magmatic bornite from South Africa.

* See Zeitschr. Kryst. Min. vol. 16, pt. 2, 1890, pp. 5-11. For very complete analyses of Norwegian 

pyrite, see E. Boettker, Rev g6n. chim. pure et app., vol. 9, p. 323.

5 Zeitschr. Kryst. Min., vol. 16, pt. 2,1890, p. 56.
ROCK-FORMING MINERALS. 319

action of fluoriferous gases upon other minerals, on volcanic lavas.1 

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.2

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,3 it is a concretionary secretion in eruptive 

granite. A more recent writer, R. Baldauf,4 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.5 It is a

double fluoride of aluminum and sodium, Na3AlF6 . Fluorine compounds, it must be observed, are rarely found in eruptive rocks. 

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, 0 

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. Fusible at about 2,250° C., according to H. Moissan.7 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.8 

They may be briefly grouped as follows: First, by direct fusion of 

amorphous alumina. Second, by the crystallization of alumina from

1 Zeitschr. Kryst. Mln., 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. Becquerel 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.

2 See the works cited elsewhere in this chapter, by Brauns, Bourgeois, and Fouqufi and L6vy.

3 Cited by F. Zirkel, Lehrbuch der Petrographie, vol. 3, p. 444. The original memoir by Johnstrup is 

not within my reach.

4 Zeitschr. prakt. Geologic, 1910, p. 432. Baldauf gives a good description of the rarer minerals associated 

with the cryolite.

" W. Cross and W. F. Hillebrand, Bull. U. S. Geol. Survey No. 20.

o The ordinary rounded-off atomic weights may be used for computations of molecular weights and 

volumes.

' Compt. Rend., vol. 115,18S2, p. 1034. 1,880° according to W. Hempel.

8 Fouque1 and L6vy, Synthese des mine'raux et des roches, Paris, 1882. L. Bourgeois, Reproduction artiflcielle des mine'raux, in Fremy's Encyclopedic chimique, vol. 2, 1st appendix. Morozewicz, Mm. pet. 

Mitt, vol. 18,1898, p. 23.
320 THE DATA OP GEOCHEMISTRY.

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, 1 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 2 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 

him only glass. When the alumina was reduced to 23 parts, zoisite 

was formed. W. Bruhns 3 obtained corundum in the wet way by 

heating alumina for ten hours to 300° in a platinum tube with water 

containing a trace of ammonium fluoride; but at 250° no crystallization 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 4 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.5 

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 littls silica, crystals of quartz appeared. By a 

similar reaction between ferric hydroxide and soda solution, Friedel 

obtained crystals of hematite.

From a geological standpoint the most important experiments 

upon the genesis of corundum are those of Morozewicz,6 who studied

1 Bull. Soc. mln., vol. 13,1890, p. 147.

2 Arch. sci. phys. nat, 3d ser., vol. 25,1891, p. 239.

a Neues Jahrb., 1889, pt. 2, p. 62.

< Annales chim. phys., 4th ser., vol. 4,1865, p. 153.

6 Bull. Soc. min., vol. 14,1891, p. 8.

« Min. pet. Mitt., vol. 18,1898, pp. 22-83. Also Zeitschr. Kryst. Min., vol. 24,1895, p. 281.
BOCK-FOBMING MINEBALS. 321

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.1 

The qualifying conditions are 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.mAl2 03 .?iSi02 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 together. With n>6, 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 : A12 03 :: 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.2 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 at once 

became significant, and in accordance with the rules developed by 

Morozewicz.

Pyrogenic corundum, according to A. Lagorio,3 is found in alumosilicate rocks only when the latter contain over 30 per cent of alumina,

1 Cordierite. The name iolite has priority and is given preference by Dana.

2 K. Busz (Geol. Mag., 1896, p. 492) found corundum in contacts between granite and clay slate on Dartmoor in Devonshire. A. K. Coomara-Swamy (Quart. Jour. Geol. 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. ,

8 Zeitschr. Kryst. Min., vol. 24,1895, p. 285. This memoir contains abundant literature references upon 

the occurrence of corundum in igneous rocks.

101381° Bull. 491 11 21
322 THE DATA OF GEOCHEMISTRY.

and such rocks are rare. Lagorio cites analyses of several examples, 

and Morozewicz * 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 2 from Canada; and corundum-bearing nepheline syenites, 

according to A. P. Coleman,3 are also found in the same region. In 

the Coimbatore district, Madras Presidency, India, T. H. Holland * 

found large crystals of corundum in an albite-orthoclase rock near its 

contact with elseolite 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 5 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, 8 but J. H. Pratt 7 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 8 as segregations in norite.9

1 Min. pet. Mitt., vol. 18,1898, pp. 212, 219. For present purposes the minor accessory minerals in these 

rocks may be ignored.

2 Am. Geologist, vol. 24,1899, p. 276.

s Jour. Geology, vol. 7, 1899, p. 437.

< Mem. Geol. Survey India, vol. 30,1901, pp. 201, 205. For Indian corundum hi general, see Holland, 

Manual of geology of India, Economic geology, pt. 1; F. R. Mallet, Rec. Geol. Survey India, vol. 5,1872, 

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 Mineralog. Mag., vol. 

11,1895, p. 56. 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. Gesell. Isis, 

July-Dec., 1907, p. 47.

6 Bull. Dept. Geology Univ. California, vol. 3,1903, p. 219.

s Bull. U. S. Geol. Survey No. 42,1887, p. 45. Chatard gives abundant references to literature. See also 

F. P. King's report upon Georgia corundum (Bull. Geol. 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, 1896. Vol. 1 of the North 

Carolina Geol. Survey, 1905, by Pratt and Lewis, is a valuable monograph on corundum and chromite.

i Am. Jour. Sci., 4th ser., vol. 6,1898, p. 49; vol. 8,1899, p. 227. In Mm. 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 ser., vol. 8, 

1899, p. 370.

s Am. Jour. Sci., 3d ser., vol. 33,1887, p. 194.

» For an account of the emery mine at Chester, Massachusetts, see B. K. Emerson, Mon. U. S. Geol. Survey, vol.29,1898, p.117. In Bull.U. S. Geol. Survey No. 269,1906, J. H. Pratt gives a very complete account 

of the corundum and emery of the United States, together with much information upon foreign localities. 

For the emery of Naxos, see S. A. Papavasiliu, Geol. Centralbl., vol. 8,1905, p. 99.
BOCK-FORMING MINERALS. 323

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 1 and L. V. 

Pirsson,2 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 natural conditions can alumina be liberated from its silicates ? 

This is a question which demands investigation, but it may be noted 

here that Vernadsky,3 by fusing muscovite, obtained sillimanite and 

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 one of the most refractory of minerals toward aqueous solvents, being insoluble in even the 

strongest acids, it is not absolutely unalterable by them. S. J. 

Thugutt 4 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. A similar prolonged treatment of corundum with a solution of the silicate K2Si5 0B 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, HA1O2 , 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.5 Among them 

gibbsite, spinel, sillimanite, kyanite, andalusite, pyrophyllite, muscovite, paragonite, chloritoid, margarite, zoisite, feldspars, tourmaline, 

and various vermiculites and chlorites have been recorded.0 Some of

1 Twentieth Ann. Eept. U. S. Geol. Survey, pt. 3,1900, p. 454.

a Idem, p. 552; Am. Jour. Sci., 4th ser., vol.'4,1897, p. 421. See also G. F. Kunz, Am. Jour. Sci., 4th ser., 

vol. 4,1897, p. 417.

a.Cited by Morozewicz, Min. pet. Mitt., vol. 18,1898, p. 25.

< Mineralchemische Studien, p. 104, Dorpat, 1891.

B For a discussion of the reactions which are supposed to produce the alterations of corundum, see C. R. 

Van Hise, Mon. U. S. Geol. Survey, vol. 47,1904, pp. 223-225.

e F. A. Genth, 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.
324 THE DATA OF GEOCHEMISTRY.

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 specimens need to be reenforced 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, FeAl2O4 . Molecular weight, 

174.1. Specific gravity, 3.93. Molecular volume, 44.3. Color, black. 

Hardness, 7.5 to 8.

These minerals, together with gahnite, ZnAl2O4 , magnetite, 

Fe"Fe'"2 04 , magnesioferrite, MgFe2O4 , franklinite, and chromite, 

form a natural isometric group, in which there are many intermediate 

mixtures. In the general formula R"R'"2 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 O=A1 0 Mg 0 A1=O, 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, Ceylon. 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. Rend., vol. 63,1866, p. 49.

D. From pyroxenite, Montana. Analysis by L. G. Eakins, Bull. U. S. Geol. Survey No. 220,1903, p. 20.

E. 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 Bb'hmerwald. Analysis by B. Quadrat, Liebig's Annalen, vol. 55,1845, p. 357.

M o

Cr208 -- -- --- - -- 

FotOa........... .............

FeO......... ........ .........

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

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

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

!Ji02 .........................

A

69.01

1.10

.71

26.21

2.02

99. 05

B

67.46

5.06

25.94

2.38

100. 84

C

59.06

10.72

13.60

17.20

100. 58

D

62.09

2.62

2.10

17.56

15.61

.16

.55

100. 69

E

60.79

5.26

21.74

12.84

100. 63

F

61.17

35.67

9 Q9

99.76
BOCK-FORMING MINERALS. 325

Members of the spinel group have been made artificially by 

methods which generally recall those mentioned under corundum. 

For example, S. Meunier 1 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 magmatic 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 have prepared spinel by direct fusion of its constituent oxides. The details 

of Morozewicz's experiments need not be repeated here.4 An interesting emphasis is given to them by the observations of G. Linck, 5

who found, in a German gabbro, spinel associated with sillimanite 

and corundum.8

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,7 spinel is among the compounds produced by 

the fusion of biotite, an observation which has been confirmed 

by C. Doelter.8 F. W. Clarke and E. A. Schneider 9 found it to be 

formed when clinochlore and xanthophyllite were strongly ignited, 

and Doelter 8 also obtained it by fusing the first-named species. 

Tourmaline, pyrope, and spessartite also yield spinel among the 

products of their fusion.10

According to Fpuque" and LeVy n spinel and melanite are formed 

when nephelite and augite are fused together, and Doelter and 

Hussak 12 obtained spinel from a mixture of fayalite and sarcolite. 

M. Vu6nik 13 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-elseplite mixtures were made by B. Vukits. 14

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.

* See also J. H. L. Vogt, Mineralbildung in Schmelzmassen, pp. 189-203. 

6 Sitzungsb. Akad. Berlin, 1893, p. 47.

 8 See also \V. Salomon. Zeitschr. Deutsch. geol. Gesell., vol. 42,1890, p. 525, for spinel in cordierite contact 

rocks in Italy.

' Cited by J. Morozewicz, Min. pet. Mitt., vol. 18; 1898. p. 59. 

s Neues Jahrb., 1897, pt. 1, p. 1. 

'Bull. U. S. Geol. Survey No. 113.1893, p. 30. 

'° Doelter, loc. cit., for tourmaline. C. Doelter and E. Hussak, Neues Jahrb., 188-t, pt. 1, p. 157, for garnets.

11 Synth&se des mineraux et des roches, p. 64.

12 Neues Jahrb., 1884, pt. 1, p. 157.

is Centralbl. Min., Geol. u. Pal., 1904, p. 297. Criticized by J. Morozewicz in the same journal, 1905, p. 148.

» Idem, 1904, pp. 710, 743.
326 THE DATA OF GEOCHEMISTRY.

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, Massachusetts, and in the norite at Crugers, New York.1 A number of remarkable spinel rocks from Elba have been described by P. Aloisi.2 A 

troctolite from Madagascar, rich in spinel, is reported by A. Lacroix.3 

Many of these occurrences are easily interpreted in the light of Morozewicz's experiments. The other experiments, cited above, 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.

Chromite. Isometric. Normal composition, FeCr2O4 , 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: 4

Analyses ofchromite.

A. From vicinity of Mundorff, British Columbia. Chrompicotite. Analysis by R. A. A. Johnston, for 

G. C. Hoffmann, Am. Jour. Sci., 4th ser., vol. 13,1902, p. 242.

B. From Corundum Hill, North Carolina. Analysis by C. Baskerville, 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 H. Traube, Zeitschr. Deutsch. geol. 

Gesell., vol. 46,1894, p. 50.

O203 --. ..............................

ALj03 .....................

Fe-A.................. ................

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

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

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

8iOa ...... .............................

*

A

55.90

13.83

14.64

15.01

.60

99.98

B

57.80

7 Q9

25.68

.69

5.22

2.80

100. 01

C

39.95

9Q 98

13.90

17.31

100. 44

Da

4Q 9Q

7 ^A

17.21

trace

18.66

6.51

99.11

E

41 93

24.58

2.28

16.99

.58

14.77

100. 43

a Also contains traces of lime, copper, and vanadium.

The earlier syntheses of chromite seem to have little or no geological bearing. S. Meunier,5 however, who prepared chromite by

i G. H. Williams, Am. Jour. Sci., 3d ser., vol. 33, 1887, p. 194. See also J. H. Pratt, Bull. U. S. Geol. 

Survey No. 269,1906, p. 34.

"Proc. verb. Soc. tosc. sci. nat., vol. 15, p. 60.

a Bull. Soc. min., vol. 31,1908, p. 318.

< A very complete collection of chromite analyses, down to 1884, with literature references, is given in 

M. E. Wadsworth's Lithological studies: Mem. Mus. Comp. Zoology, Cambridge, Mass., vol. 11, 1884. 

A mineral from Servia, of composition FeaOa.CrjOa, has been named chromitite by M. Z. JovitschitschMonatsh. Chemie, vol. 30,1909, p. 39.

5 Compt. Rend., vol. 110,1890, p. 424.
BOCK-FORMING MINERALS. .327

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 x thus interprets the chromite deposits of Norway, and J. H. Pratt 2 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, Fe304 , 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 wellknown subclass of ores. In a magnetite from the Tyrolese Alps 

T. Petersen 3 found 1.76 per cent of nickel oxide, and the magnetites 

of eastern Ontario may contain half as much.4

Magnetite is often observed as a furnace product, and it forms the 

"iron scale" of the blacksmith. W. Miiller 5 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 0 prepared it, well crystallized, by fusing together an iron silicate and lime 

According to H. Sainte-Claire Deville, 7 ferrous oxide, heated in a 

stream of hydrochloric acid, forms magnetite, while a mixture of 

magnesia and ferric oxide, similarly treated, yields magnesioferrite, 

MgFe204 . T. Sidot 8 obtamed 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

» Zeitschr. prakt. Geologic, 1S94, p. 384.

2 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.

a Neues Jahrb., 1867, p. 836.

« W. G. Miller, Rept. British Assoc., 1897, p. 600.

»Zeitschr. Deutsch. geol. Gesell., vol. 45,1893, p. 63.

« Compt. Bend., vol. 33,1851, p. 528.

' Idem, vol. 53,1861, p. 199.

»Idem, vol. 69,1869, p. 201.
328 THE DATA OF GEOCHEMISTRY.

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.1 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,2 for example, repeatedly obtained it by fusing various rocks in contact with 

limestone a procedure which recalls Ebelmen's experiment. Acmite upon fusion yields magnetite and a glass,3 and glaucophane 

gives similarly a mixture in which magnetite appears. By melting 

together biotite and microcline, Fouque1 and LeVy 4 obtained magnetite, 

leucite, and olivine. J. Lenarci6 5 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. Vu6nik6 and B. Vukits,7 who found magnetite among the fusion 

products of anorthite and hedenbergite, albite and hedenbergite, 

olivine and augite, elseolite and augite, and elseolite 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 nephelme 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. 8 . Some ores shade from magnetite 

into ilmenite, with over 40 per cent of titanic oxide. They frequently 

contain spinel, and sometimes, also, corundum.

i See J. Morozewicz, Min. pet. Mitt., vol. 18,1898, p. 84, and J. H. L. Vogt, Mineralbildung in Scnmelzmassen, pp. 203-212.

a Neues Jahrb., 1886, pt. 1, p. 128.

3 Doelter, Neues Jahrb., 1897, pt. 1, p. 1. See also M. Vu6nik, cited below.

< Synthese des mine'raux et des roches, p. 77.

6 Centralbl. Min., Geol. u. Pal., 1903, pp. 705, 743.

8 Idem, 1904, pp. 300, 342, 344, 345, 366, 369.

' Idem, 1904, pp. 705, 715, 743, 748.

« See J. H. L. Vogt, Zeitschr. prakt. Geologie, 1893, p. 6; 1894, p. 382; 1900, pp. 234, 370; 1901, pp. 9,180, 

289, 327. J. F. Kemp, Nineteenth Ann. Kept. U. S. Geol. Survey, pt. 3, 1899, p. 377; School of Mines 

Quart., vol. 20, p. 323,1899; vol. 21, p. 56,1900; Zeitschr. prakt. Geologie, 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 

Erzlagerstiitten, 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. Geologie, 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 

Lapland, see O. Stutzer, Neues Jahrb., Beil. Bd. 24,1907, p. 548.
BOCK-FORMING MINERALS. 329

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 griinerite and actinolite.1 Here the mineral is not of direct igneous origin. In the Mesabi 

district, according to C. K. Leith,2 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,3 from marcasite and pyrite, and from the oxidation of siderite 

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 GayLussac,4 the vapor of ferric chloride was decomposed by steam at a 

high temperature, and crystals of hematite were formed. A. Daubre"e 5 obtained it by passing ferric chloride vapor over lime; and 

H. Sainte-Claire Deville 6 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,7 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.8 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 the sulphur gases from the fuel upon 

the iron.9 Ferric chloride or sulphate 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, 19 on comparing the volcanic mineral with the 

artificial product, found them to be crystallographically identical.

1 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. 36,1899; and vol. 45,1903.

2 Mon. U. S. Geol. Survey, vol. 43,1903, pp. 101-115.

8 A treatise on metamorphism: Mon. U. S. Geol. Survey, vol. 47,1904, p. 229. 

< See R. Brauns, Chemische Mineralogie, 1896, p. 231. 

8 Compt. Rend., vol. 39,1854, p. 135. 

«Idem, vol. 52,1861, p. 1264.

* Zeitschr. anorg. Chemie, vol. 6,1894, p. 377; Bull. Acad. Belglque, 3d ser., vol. 27, p. 933. 

s See H. Vater, Zeitschr. Kryst. Min., vol. 10,1885, p. 391; and B. Doss, idem, vol. 20,1892. p. 566. 

«C. E. Munroe, Am. Jour. Sci., 4th ser., vol. 24,1907, p. 485. 

»o Zeitschr. Kryst. Min., vol. 18,1891, p. 46.
330 THE DATA OF GEOC'HEMISTBY.

W. Bruhns's experiment,1 in which hematite was formed by heating 

amorphous ferric oxide with water and a trace of ammonium fluoride 

to 300° in a platinum tube, seems to be less closely related to geological phenomena.

Fouque" and Levy 2 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,3 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 magnetite. 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,4 being 3.46 FeO 

and 2.63 Fe2 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 

accompanying the ferromagnesian minerals.

Hematite alters into limonite, magnetite, pyrite, marcasite, and 

siderite,5 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,6 in a Swedish ore, found molybdenum in very appreciable 

amounts.

TITANIUM MINERALS.

Umenite. Rhombohedral. Composition, FeTi03. Molecular 

weight, 152. Specific gravity, 4.5 to 5. "Molecular volume, 30.4. 

Color, black; luster, submetallic. Hardness, 5 to 6.

Umenite, menaccanite, or titanic iron has been little investigated 

upon the synthetic side. W. Bruhns 7 prepared it, mixed with some 

magnetite, by heating finely divided metallic iron, ferric oxide, and 

amorphous titanic oxide with hydrochloric acid in a platinum tube 

to 270-300°. In nature, however, it is found most widely diffused.

» Neues Jahrb., 1889, pt. 2, p. 02.

* Synthese des mine'raux et des roches, p. 236.

»Mineralbildung in Schmelzmassen, pp. 215-217. Cf. also J. Morozewicz, Min. pet. Mitt., vol. 18,1898, 

p. 84. 

< Bull. U. S. Geol. Survey No. 228,1904, p. 17.

* C. R. Van Hise, A treatise on metamorphism: Mon. U. S. Geol. Survey, vol. 47,1904, p. 226. 

« Zeitschr. Kryst. Min., vol. 25,1896, p. 94. 

i Neues Jahrb., 1889, pt. 2, p. 65.
BOCK-FORMING MINEEAI/S. 331

It occurs with or replacing hematite in granite and syenites and as an 

essential constituent in diorite, diabase, gabbro, basalt, etc., often 

with magnetite. 1 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 2 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,3 who prepared the latter compound artificially, do not favor this view. Ti203 as such has not been 

found as an independent mineral. T. Konig and 0. von der Pfordten 4 

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 5 

have shown, ilmenite sometimes contains large admixtures of the 

molecule MgTiO3 , 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 8 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, 7 this substance is essentially 

titanite, sometimes accompanied by rutile.

Pseuddbrookite. 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, 8 who gave it the formula Fe2Ti05 and made it 

isomorphous with andalusite, Al2Si05. The natural mineral, however, 

has the orthotitanate formula, as given above.0

PerofsJcite. 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.

1 See the papers of Vogt, Kemp, and others cited under magnetite. The titaniferous magnetites are 

mixtures of that species with ilmenite. See also A. Cathrein, Zeitschr. Kryst. Min.,vol. 8,1884, p. 321.

» Zeitschr. Kryst. Min., vol. 8,1884, p. 54.

» Annales chim. phys., 5th ser., vol. 8,1876, p. 38.

« Ber. Deutsch. chem. Gesell., vol. 22,1889, p. 1485.

6 Am. Jour. Sci., 4th ser., vol. 4,1897, p. 108.

«A description of geikielite by T. Crook and B. M. Jones is printed In Mineralog. Mag., vol. 14,1906, p. 160.

i Zeitschr. Kryst. Min., vol. 6,1882, p. 244.

8 Idem, vol. 20,1892, p. 566. Doss gives a good bibliography of pseudpbrookite.

8 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.
332 THE DATA OF GEOCHEMISTRY.

Perofskite has been prepared synthetically by several chemists. 

J. J. Ebelmen 1 obtained it by fusing titanic oxide with lime and 

potassium carbonate; and later 2 by the action of lime on an alkaline 

melt containing titanic oxide and silica. P. Hautefeuille 3 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, 4 observed its deposition from 

various fused mixtures resembling natural magmas in composition. 

Finally, P. J. Holmquist 5 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; 6 and is among the earliest secretions. It is particularly characteristic of melilite basalt, being, according to A. Stelzner, 7 the most 

faithful companion of melilite. At Catalao, Brazil, E. Hussak 8 

found a peculiar rock consisting of magnetite and perofskite; a titanSerous magnetite of a new kind. The mineral is also found in 

chlorite schist, limestone, quartz gneiss, 9 etc. Hussak observed its 

alteration into titanic oxide, and K. Schneider 10 has described perofskite as derived from titanite. .

Titanite. Monoclinic. Composition, CaTiSi05 . 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 u 

prepared it by fusing a mixture of silica and titanic oxide with calcium chloride. L. Bourgeois 12 obtained it, but obscurely developed, 

by fusing together its constituent oxides, silica, titanic oxide, and 

lime. L. Michel 13 fused ilmenite with calcium sulphide, silica, and 

carbon, which yielded a mixture of titanite, garnet, and a subsulphide of iron.

As a pyrogenic mineral titanite is found among the oldest secretions 

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

1 Compt. Rend., vol. 32,1851, p. 710.

2 Idem, vol. 33,1851, p. 528.

s Annales chim. phys., 4thser., vol. 4,1865, p. 163.

«Idem, 5th ser., vol. 29,1883, p. 479.

6 Bull. Geol. Inst. Upsala, vol. 3,1896-97, p. 181.

« See G. H. Williams, Am. Jour. Sci., 3d ser., vol. 34,1887, p. 137; J. S. Diller, idem, vol. 37,1889, p. 219.

' Neues Jahrb., Beil. Bd. 2,1883, p. 390. ' 

s Neues Jahrb., 1894, pt. 2, p. 297.

«See 0. Miigge, Neues Jahrb., Beil. Bd. 4,1886, p. 581. 

10 Neues Jahrb., 1889, pt. 1, p. 99. 

u Annales chim. phys., 4th ser., vol. 4,1865, p. 129. 

»Idem, 5th ser., vol. 29,1883, p. 474. 

»»Compt. Bend., vol. 115,1892, p. 830.
BOCK-FOBMING MINERALS. 333

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 x 

this product is a hydrous titanate of aluminum. An alteration of 

titanite into rutile has been observed by P. Mann 2 in the foyaite of 

the Serra de Monchique; and B. Doss 3 has reported pseudomorphs 

of anatase after sphene.

Rutile. Tetragonal. Composition, Ti02 . Molecular weight, 80.1. 

Specific gravity, 4.2. Molecular volume, 19.1. Color, commonly 

reddish 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. Daubre"e, 4 by the 

action of aqueous vapor upon titanic chloride at a red heat. By 

heating amorphous titanic oxide to redness in a current of hydrochloric acid gas, H. Sainte-Claire Deville and H. Caron 5 transformed 

it into a crystalline modification, and similar results were obtained 

by P. Hautefeuille and A. Perrey.6 By the prolonged heating of 

titanic oxide with boric acid J. J. Ebelmen 7 obtained rutile, and 

P. Hautefeuille 8 attained the same end when sodium tungstate or 

vanadate was used as flux. H. Traube 9 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, 10 by this method, prepared both rutile and anatase. Deville 

and Caron n 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 12 obtained a mixture of rutile 

and pyrrhotite. __________________________

i Bull. U. S. Geol. Survey No. 60,1890, p. 136.

»Neues Jahrb., 1882, pt. 2, p. 200.

s Idem, 1895, pt. 1, p. 128.

«Compt. Rend., vol. 29,1849, p. 227.

6 Idem, vol. 53,1861, p. 161.

«Idem, vol. 110,1890, p. 1038.

»Idem, vol. 32,1851, p. 330.

»Cited by Bourgeois, Reproduction artiflcielle des mine'raux, 1884, p. 85.

» Neues Jahrb., Beil. Bd. 10,1895-96, p. 470.

>o Idem, 1894, pt. 2, p. 147.

" Compt. Rend,, vol. 53,1861, p. 161.

" Idem, vol. 115,1892, p. 1020.
334 THE DATA OP GEOCHEMISTRY.

The three forms of titanic oxide were reproduced by P. Hautefeuille 1 by various modifications of the same general prieumatolytic 

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 products, which, when the 

operation was conducted at a strong red heat, was rutile. Brookite 

was formed by heating potassium titanofluoride in aqueous vapor, 

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 pneumatolytic 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 hornbrende gneiss from Freiberg, A. Bergeat 2 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, 3 consists essentially of 

rutile and apatite. Rutile is also found as a secondary mineral, 

derived from ilmenite and titanite. C. Doelter 4 found rutile to be 

slightly soluble in water, and more so in a solution of sodium fluoride. 

From such a solution, containing rutile, 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, diorite, the crystalline schists, shales, sandstones, and limestones. 5

i Annales chim. phys., 4th sen, vol. 4,1865, p. 129.

* Neues Jahrb., 1895, pt. 1, p. 232.

« Bull. U. S. Geol. Survey No. 430,1910, p. 200.

«Min. pet. Mitt., vol. 11,1890, p. 325.

6 For a very full summary of the occurrence of zircon and the titanium minerals, especially brookite and 

anatase, see II. Thiirach, Verhandl. Phys. med. Gesell. Wiirzburg, vol. 18, No. 10,1884. On the rutile of 

Nelson County, Virginia, see T. L. Watson, Econ. Geology, vol. 2,1907, p. 493.
HOCK-FORMING MINERALS. 335

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.

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. Daubre'e 1 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. 6 

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 R. 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 pegma1 Compt. Rend., vol. 29,1849, p. 227. 

»Idem, vol. 53,1861, p. 161. 

a Idem, vol. 96,1883, p. 701. 

< Idem, vol. 46,1858, p. 766. 

s Zeitschr. Kryst. Min., vol. 25,1896, p. 467. 

" Idem, vol. 31, p. 279.

i For a list of the minerals occurring with cassiterite, see W. Kohlmann, Zeitschr. Kryst. Min., vol. 24, 

1895, p. 350.

8 Neues Jahrb., 1885, pt. 2, p. 88.

» Zeitschr. Kryst. Min., vol. 33, 1900, p. 205.

10 Bull. U. S. Geol. Survey No. 293,1906.
336 THE DATA OF GEOCHEMISTRY.

tite 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 1 obtained it by heating zirconia in a 

current of silicon fluoride. Deville 2 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. Perrey 3 

obtained zircon when a mixture of silica, zirconia, and lithium molybdate was heated to 800°. Finally, K. Chrustschoff 4 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. 5 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. 6 They are Ca5 (P04) 3 F and Ca5 (PO4) 3 C1. 

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.

1 Compt. Rend., vol. 46,1858, p. 764.

2 Idem, vol. 52,1861, p. 780.

3 Idem, vol. 107,1888, p. 1000.

* Neues Jahrb., 1892, pt. 2, p. 232.

6 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.

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.
BOCK-FORMING MINEEALS. 337

The first synthesis of apatite was effected by A. Daubre'e, 1 who 

obtained it in crystals by passing the vapor of phosphorus trichloride 

over red-hot lime. N. S. Manross 2 fused sodium phosphate either 

with calcium chloride, calcium fiuoride, 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 3 successfully. G. Forchhammer 4 prepared 

chlorapatite 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, 5 who fused bone ash with ammonium chloride 

and either calcium chloride or fiuoride, and also by A. Ditte, 6 who 

repeated Forchhammer's experiment. By heating calcium phosphate 

with calcium chloride and water, under pressure, at 250°, H. Debray 7 

prepared chlorapatite. E, Weinschenk 8 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 9 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 (PO4 ) 2 .CaCl2 . 

Apatite has been reported as present in lead-furnace slags by W. M. 

Hutchins 10 and J. H. L. Vogt.11 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. Titaniferpus 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 12 regards it as having been formed by pneumatolytic 

agencies. According to R. Muller, 13 apatite is strongly attacked by

i Compt. Rend., vol. 32,1851, p. 625. 

' * Liebig's Annalen, vol. 82,1852, p. 353. 

3 Idem, vol. 97,1856, p. 95.

* Idem, vol. 90,1854, pp. 77,322. 

« Compt. Rend., vol. 47,1858, p. 985. 

« Idem, vol. 94,1882, p. 1592.

 ' Idem, vol. 52,1861, p. 44.

* Zeitschr. Kryst. Min., vol. 17,1890, p. 489. 

s Jour. Phys. Chem., vol. 15,1911, p. 464. 

 Nature, vol. 36,1887, p. 460. 

" Mineralbildung in Schmelzmassen, p. 263.

'3 See.his paper in Trans. Am. Inst. Min. Eng., vol. 31,1901, p. 134, and also papers in Zeitschr. prakt. 

 Geologic, 1894, p. 458; 1895, pp. 367.444, 465.

 '« Jahrb. K.-K. geol. Reichsanstalt, vol. 27, Min. pet. Mitt., 1877, p. 25.

.101381° Bull. 491 11 22
338 THE DATA OF GEOCHEMISTRY.

waters containing carbonic acid. Both lime and phosphoric acid 

pass into solution. A carbonated mineral allied to apatite has lately 

been described by W. Tschirwinsky, 1 under the name podolite. 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 

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, YP04, 

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,2 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 O. A. Derby,3 these two species, although they occur 

sparingly j are very common accessory minerals in Brazilian granites 

and gneisses. The monazite 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. O. A. 

Derby 4 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 5 found several occurrences of monazite, and 

one of xenotime. W. Ramsay and A. Illiacus 6 also report the presence of monazite in the pegmatites of Finland. W. E. Hidden 7 

found crystals of xenotime, intergrown with zircon, in a decomposing 

granite in He'nderson 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,8 who give very complete analyses of several samples. In North

1 Centralbl. Min., Geol. u. Pal., 1907, p. 279. According to W. T. Schaller (Am. Jour. Sci., 4th sen, vol. 30, 

1910, p. 309), podolite is identical with dahllite, which was described much, earlier.

2 Compt. Rend., vol. 80,1875, p. 304.

s Am. Jour. Sci., 3d ser., vol. 37,1889, p. 109; vol. 41,1891, p. 308. 

«Idem, 4th ser., vol. 13,1902, p. 211. 

5 Proc. Rochester Acad. Sci., vol. 1,1891, p. 198. 

« Zeitschr. Kryst. Min., vol. 31,1899, p. 317. 

i Am. Jour. Sci., 3d ser., vol. 36,1888, p. 380.

8 Zeitschr. Kryst. Min., vol. 37,1903, p. 550. Another memoir on the Brazilian sands, by A. 

appears in Ann. Escola de Minas, No. 6, Ouro Preto, 1903.
BOCK-FORMING MINEEALS. 339

Carolina 1 the sands are derived from gneiss, and W. Lindgren 2 

reports sands of granitic origin from the Idaho Basin, Idaho.

THE SILICA MINERALS.

Quartz. Rhombohedral. Composition, silicon dioxide, Si02 . 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.

Cristobalite.3 Pseudocubic. Composition like quartz, Si02 . Molecular weight, 60.4. Specific gravity, 2.348. Molecular volume, 25.7.

Tridymite. Hexagonal. Composition like quartz, Si02 . Specific 

gravity, 2.3. Molecular volume, 26.3.* Colorless or white. Hardness, 7. Fuses at about 1,625°.

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.4

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,5 

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. 6 The siliceous 

sinters deposited by hot springs are all classed as opal. At the hot 

springs of Plombie'res, in France, common opal and hyalite have been

1 See report on monazite by H. B. C. Nitze, Sixteenth Ann. Kept. U. S. Geol. 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 Kevue gfin. sci., vol. 9,1898, p. 145, and, translated into English, in 

Chem. News, vol. 77, pp. 135,145.

2 Am. Jour. Sci., 4th ser., vol. 4,1897, p. 63. Also in Eighteenth Ann. Kept. 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 the 

Malay Peninsula, idem, vol. 4,1906, p. 301.

s See G. vom Rath, Neues Jahrb., 1887, pt. 1, p. 198; E. Mallard, Bull. Soc. Min., vol. 13,1890, p. 172; 

P. Gaubert, idem, vol. 27,1904, p. 242.

4 See also A. L. Day and E. S. Shepherd on quartz glass, in Science, 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°.

6 For recent discussions upon the nature of chalcedony, etc., see A. Michel Lfivy and E. MunierChahnas, 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. Bd., 

vol. 25,1908, p. 182, on the relation of fibrous silica to quartz an* opal.

« For details concerning syntheses of opal, see I>. Bourgeois, Reproduction artificielle des mine'raiix, 

1884, p. 93.
340 THE DATA OF GEOCHEMISTRY.

formed by the action of the waters upon an ancient Roman cement. 1 

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.

On the artificial production of quartz and tridymite there have been 

many researches. P. Schafhautl 2 simply heated a solution of colloidal silica in a Papin digester, and obtained a crystalline deposit 

of quartz. H. de Senarmont 3 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 4 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; 5 and he furthermore observed 

its deposition from the waters of PlombiSres.8 To K. Chrustschoff 7 

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 8 produced quartz 

by heating, in a steel tube, caustic potash, gelatinous silica, and 

amorphous alumina nearly to redness during fourteen to thirty-eight 

hours. When the experiment was conducted at a higher temperature they obtained tridymite and quartz side by side. W. Bruhns,9 

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 fifty-three 

hours, tridymite was formed. E. Baur 10 claims to have obtained 

quartz and tridymite simultaneously, as did Friedel and Sarasin, 

when a mixture of silica, sodium aluminate, and water was heated 

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 u when

1 See A. Daubr6e, Etudes synthfitiques de g6ologie exp6rimentale, 1879, p. 189.

2 Cited by L. Bourgeois, Reproduction artificielle des mine'raux, 1884, p. 80. 

a Annales chim. phys., 3d ser., vol. 32,1851, p. 142. 

* Compt. Rend., vol. 39,1854, p. 135.

6 Etudes synth6tiques de g6ologie expfirimentale, 1879, p. 158. 

«Idem, p. 175.

' Am. Chemist, vol. 3,1873, p. 281. Compt. Rend., vol. 104,1887, p. 602. Neues Jahrb., 1897, pt. 1, p. 240, 

Referate. 

s Bull. Soc. min., vol. 2,1879, pp. 113,158.

9 Neues Jahrb., 1880, pt. 2, p. 62.

10 Zeitschr. physikai. Chemio, vol. 42,1903, p. 572. Questioned by A. L. Day and E. S. Shepherd, Am. 

Jour. Sci., 4th ser., vol. 22,1906, p. 276.

'- Centralbi. Min,, Gcol. u. Pal., 1906, pp. 339, 3H. The authors discuss at length the relations between 

quartz and tridymite.
KOCK-FOBMING MINERALS. 341

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 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 c 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. Hautef euille 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.

1 Cited by Day and Shepherd, op. cit., p. 297.

2 Proc. Roy. Soc. Edinburgh, vol. 11,1880, p. 37.

3 Ber. Deutsch. chem. Gesell., vol. 2,1869, p. 388.

«Neues Jahrb., 1887, pt. 1, p. 205.

B Idem, 1897, pt. 2, p. 147.

»Idem, 1881, pt. 1, p. 145.

' Bull. Soc. min., vol. 1,1878, p. 113.

8 Centralbl. Min., Geol. u. Pal., 1904, p. 87.

» Compt. Rend., vol. Ill, 1890, p. 509. 

w Bull..Soc. min., vol. 1,1878, p. 1.

» Cited by L. Bourgeois, Reproduction arttflcielln des mineraux, 1884, p. 81. 

12 Bull. Soc. min., vol. 4,1881, p. 244. 

" Arch. sci. phys. nat., 4th ser., vol. 25,1908, p. 610. See also Vogt, Min. pet. Mitt., vol. 25,1900, p. 408.
342 THE DATA OF GEOCHEMISTRY.

These experiments show that quartz may be produced without the 

intervention of water, but it is not always so formed. Quartz 

crystals often contain 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 1 found that quartz sand 

was transformed to tridymite at 1,500°, and suggested that the true 

inversion temperature might 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.

It is possible to go even farther in the use of ' 'quartz as a geologic 

thermometer," to use the significant expression of F. E. Wright and 

E. S. Larsen.5 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 ft 

quartz, the change being reversible. At ordinary temperatures all 

quartz is a quartz; but if at any time it has been heated above 575°, 

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.

In all probability quartz and tridymite are polymers of the fundamental molecule Si02 . Tridymite is the lower, less complex polymer, 

and is therefore the more stable at high temperatures. The syn-

! i Geol. Mag., 1906, p. 118.

2 Centralbl. Min., Geol. u. Pal., 1906, pp. 657, 728. .Quensel puts the melting point of tridymite as low 

as 1,560° and claims to have observed incipient fusion at 1,500°.

s 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., 4th ser., vol. 28,1909, p. 293.

6 Idem, p. 421. See also an earlier paper by 0. Miigge, Neues Jahrb., Festband, 1907, p. 181, and other 

memoirs cited by Wright and Larsen.
BOCK-FORMING MINERALS. 343

thetic data all bear out this conclusion and show the difficulty of 

preparing pyrogenic quartz from magmatic mixtures. J. Morozewicz 1 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 Le"vy,2 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.3 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 

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,4 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.

i Min. pet. Mitt., vol. 18,1898, pp. 158-166.

1 Synthese des mineraux et des roches, pp. 88,89.

» F. W. Clarke, Bull. U. S. Geol. Survey No. 228,1904, pp. 19,20.

«See p. 288, ante.
344 THE DATA OF GEOCHEMISTEY.

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 Pel6e has been especially studied by A. Lacroix. 1 

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. 2 The dissociation hypothesis, offered in the 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,3 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.4 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.5 These experiments by Spezia shed much light upon the

1 Bull. Soc. min., vol. 28,1905, p. 56. See also Lacroix on tridymite from Vesuvius, idem, vol. 31,1908, 

p. 323.

2 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. Geol. Survey No. 79,1891, on quartz basalts 

from California. Also a note by Diller, in Science, 1st ser., vol. 13,1889, p. 232, on porphyritic quartz in 

eruptive rockc. 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.

'Jour. Cbem. Soc., vol. 76, pt, 2,1899, p. 300.

< Idem, vol. 78, pt. 2,1900, p. 595.

»Idem, vol. 80, pt. 2, 1901, p. 605. For Spezia's original papers, of which these notes are abstracts, see 

Attl 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.
BOCK-FORMING MINERALS. 345

deposition of opal or quartz as a cementing material. There is also a 

suggestive experiment reported by Ramsay and Hunter, 1 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.2 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.

Orthoclase. Monoclinic. Composition, KAlSi3O8 . Molecular weight, 

279.4. Specific gravity, 2.56. Molecular volume, 109.1. Colorless, 

often reddish or yellowish, sometimes gray or green. Hardness, 

6 to 6.5.

Microcline. Triclinic. Composition, specific gravity, hardness, 

etc., like orthoclase.

ATbite. Triclinic. Composition, NaAlSi308 . Molecular weight, 

263.3. Specific gravity, 2.605. Molecular volume, 101.1. Colors as 

in orthoclase, commonly white. Hardness, 6 to 6.5.

Anorthodase. Triclinic. Intermediate in composition between 

albite and microcline.

Anorihite. Triclinic. Composition, CaAl2Si208 . Molecular weight, 

279.1. Specific gravity, 2.765. Molecular volume, 100.9. Fuses at 

1,542°. 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 3 this soda 

orthoclase is very nearly represented by a supposed albite from 

Kragero, Norway. Similarly, sodium may replace calcium in anorthite, forming a triclinic isomer of nephelite, with the formula 

Na2Al2Si2 08 . This compound has been prepared synthetically, and 

also identified by H. S. Washington and F. E. Wright 4 as a constituent of a feldspar from the Island of Linosa, east of Tunis. For the

iRept. British Assoc. Adv. Sci., 1882, p. 239.

2See C. W. Hayes, Bull. Gool. 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. Rinne, Centralbl. Min., Geol. u. Pal., 1904, p. 333. On the solubility 

of quartz in alkaline solutions, as conditioned by the fineness of its subdivision, see G. Lunge and C. Millberg, Zeitschr. angew. Chemie, 1897, p. 393.

8 Bull. Soc. chim., 4th ser., vol. 3, 1908, p. 894. W. T. Schaller (Am. Jour. Sci., 4th ser., vol. 30,1910, p. 

358) proposes to name this soda orthoclase barbierite.

* Am. Jour. Sci., 4Jh ser., vol. 29, 1910, p. 52.
346 THE DATA OF GEOCHEMISTRY.

sodium anorthite itself they propose the name carnegielite, 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, BaAlSi208 . 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......................................... Ab6Ant to Ab3An1 .

Andesine............:............................ Ab3An1 to Ab 1An1 .

Labradorite....................................... AbiAr^ to A^Aiia.

Bytownite......................................... AbiAn3 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.1 On purely chemical grounds, the 

prevalent opinion is the more probable, and the observations of A. L. 

Day and E. T. Alien 2 upon the melting points of the feldspars support this conclusion. Their data are as follows:

Melting points of feldspars.

Anorthite........................ 1, 542

A^Ang........................... 1, 500

Ab tAn2-.......................... 1,463

Al^Ant.......................... 1,419

Ab2An!.......................... 1, 367

AbgAn!.-........................ 1, 340

These figures give a regular curve, but from this point on to the 

albite molecule 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 3 observed its formation in 

slags, and J. Morozewicz 4 repeatedly obtained feldspars varying 

from labradorite to nearly pure anorthite in his experiments with 

artificial magmas. Fouque and LeVy 5 obtained anorthite directly 

from its constituents; and S. Meunier,8 upon fusing silica, lime, and 

aluminum fluoride together, found sillimanite, tridymite, and anor1 See for example W. Tarassenko, Zeitschr. Kryst. Min., vol. 36,1902, p. 182.

2 Am. Jour. Sci., 4th sen, vol. 19,1905, p. 93. 

8 Mineralbildung in Schmelzmassen, p. 181. 

< Min. pet. Mitt., vol. 18,1898, p. 156. 

* Synthese des mine'raux et des roches, p. 138. 

«Compt. Rend., vol. Ill, 1890, p. 509.
ROCK-FORMING MINERALS. 347

thite in the resultant mass. Anorthite is also formed by the breaking 

down of other more complex silicates. A. Des Cloizeaux, 1 by fusing 

garnet and vesuvianite, obtained crystals which Fouque" and LeVy 

identified as anorthite; and similar results are reported, with much 

more detail, by C. Doelter and E. Hussak.2 Doelter 3 also found 

anorthite among the products formed by fusing epidote, axinite, chabazite, and scolecite. Finally, C. and G. Friedel 4 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 5 

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 

been made synthetically by E. Dittler.0

All attempts to prepare the alkali feldspars by 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 Fouqu6 and LeVy 7 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. Lenarci6 8 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. Hautefeuille 9 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, 10 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 n produced both quartz and orthoclase, 

and a potassium feldspar was also obtained by Doelter 12 when a

1 Manuel de mineralogie, vol. 1,1862, pp. 277, 543.

2 Neues Jahrb., 1884, pt. 1, p. 158.

8 Idem, 1897, pt. 1, p. 1; Allgem. chem. Mineralogie, p. 183.

< Compt. Rend., vol. 110,1890, p. 1170.

6 Synthese des minfiraux et des roches, p. 145. 

o Min. pet. Mitt., vol. 29,1910, p. 273.

7 Synthese des mindraux et des roches, pp. 142-145.

8 Centralbl. Min., Geol. u. Pal., 1903, p. 705.

» Compt. Rend., vol. 84,1877, p. 1301. 

J° Idem, vol. 85,1877, p. 952. 

» Idem, vol. 90,1880, p. 830. 

» Neues Jahrb., 1897, pt. 1, p. 1.
348 THE DATA OF GEOCHEMISTRY.

mixture corresponding to KAlSiO4 was fused with potassium fluoride 

and silicofluoride. How these extraneous substances act is not clear. 

Day and Alien, 1 repeating a part of Hautefeuille's work, heated a 

powdered albite glass with sodium tungstate and succeeded in bringing about a 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 2 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 3 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. 

ChrustschofF, 4 who heated an aqueous solution of dialyzed silica with 

a little alumina and caus'tic potash to 300° during several months, 

when quartz and orthoclase formed. C. and G. Friedel 5 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 6 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.7 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 statei Am. Jour. Sci., 4th ser., vol. 19, 1905, p. 117. 

8 Compt. Rend., vol. 92,1881, p. 1374. 

3 Idem, vol. 97,1883, p. 290. 

«Idem, vol. 104,1887, p. 602. 

»Idem, vol. 110,1890, p. 1170.

6 Zeitschr. physikal. Chemie, vol. 42,1903, p. 567. The paper id illustrated by diagrams based upon the 

phase rule. 

iSee F. W. Clarke, Bull. U. S. Geol. Survey No. 228,1904, p. 20.
BOCK-FORMING MINERALS. 349

merit, 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. 1 Orthoclase, probably of 

aqueous origin, sometimes occurs as a gangue mineral in metalliferous 

fissure veins. 2

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 dioxide, 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 

of A. Daubr6e 3 are perhaps the most classic. Fragments of orthoclase 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 K2O were thus extracted and found in the filtered solution. 

To water charged with carbon dioxide 2 kilograms of orthoclase, 

after ten 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.4 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,5 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 orthoclase into 

albite. 8

1 For example, crystals of anorthite occur with epidote in the limestone of Phipsburg, 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 anorthite from the limestone of Franklin, New Jersey, near its contact with granite.

2 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.

3 litudes synthfitiques de g6ologie exp6rimentale, 1879, pp. 268-275.

4 Zeitschr. Deutsch. geol.'Geiell., vol. 39,1887, p. 559.

5 See J. W. Jucld, Mineralog. Mag., vol. 8,1889, p. 186, on the alteration of plagioclase into scapolite. 

8 For an example of this kind see F. A. Genth, Proc. Am. Philos. Soc., vol. 20,1882, p. 392.
350 THE DATA OF GEOCHEMISTRY. 

LEUCITE AND ANALCITE.

Leucite. Isometric. Composition, KAlSi206 . 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 .H2O. Molecular 

weight, 220.9. Specific gravity, 2.25. Molecular volume, 98.2. 

Colorless or white, sometimes tinted by impurities. Hardness, 5 to

5.5.

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 x 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. Lemberg 3 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.

Leucite and analcite are both 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,5 who also formed leucite, with other minerals, from 

various artificial magmas.6 By fusion of its constituents with potassium vanadate, P. Hautefeuille 7 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 8 and A. Duboin.9 C. Doelter, 10 by fusing a mixture 

equivalent to Al203 + 2SiO2 with sodium fluoride, prepared a soda 

leucite, NaAlSi206 . When microcline and biotite are fused together, leucite appears 

among the products; u and Doelter 12 found that it was formed when

1 Bull. Soc. min., vol. 19,1896, p. 363.

2 F. W. Clarke and G. Steiger, Bull. U. S. Geol. Survey No. 207,1902.

a Zeitschr. Deutsch. geol. Gesell., vol. 28,1876, pp. 537 et seq.

« Mineralchemische Studien, Dorpat, 1901, pp. 100,101.

& Synthese des mine'raux et des roches, p. 153.

« Bull. Soc. min., vol. 2,1879, p. Ill; vol. 3,1880, p. 118.

i Cited by L. Bourgeois, Reproduction artiflcielle des mine'raux, p. 130.

scompt. Rend., vol. 90,1880, p. 1009; vol. Ill, 1890, p. 509.

o Idem, vol. 114,1892, p. 1361.

10 Neues Jahrb., 1897, pt. 1, p. 1.

" Fouque" and L6vy, Synthese des mine'raux et des roches, p. 77.

"Loc.cit.
BOOK-FORMING MINEBALS. 351

muscovite, lepidolite, or zinnwaldite was fused alone. It was also 

produced hydrochemically by C. and G. Friedel 1 when muscovite was 

heated to 500° in a steel tube with silica and a solution of potassium 

hydroxide.

The syntheses of analcite have all been effected under pressure, and 

in the wet way. A. de Schulten 2 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.3 C. Friedel and E. Sarasin 4 prepared analcite by 

heating precipitated aluminum silicate with sodium silicate and water 

to 500° in a sealed tube. J. Lemberg 5 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 6 the 

reaction with andesine is not reversible. The two alterations, therefore, are chemically unlike. Analcite may also be generated by alteration from elseolite and aegirite.7 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.8 In 

an artificial leucite-tephrite magna, kept at a red heat, the difficulty 

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.9

Analcite is most frequently found as a secondary mineral, the product of zeolitization; and until recent years it was supposed to have

1 Compt. Rend., vol. 110,1890, p. 1170.

2 Idem, vol. 90,1880, p. 1493; Bull. Soc. min., vol. 3,1880, p. 150. 

a Compt. Rend., vol. 94,1882, p. 96. 

«Idem, vol. 97,1883, p. 290.

<* Zeitschr. Deutsch. geol. Gesell., vol. 39,1887, p. 559. 

« Neues Jahrb., Beil. Bd. 9, 1894-95, p. 604.

i See W. C. Brogger, Zeitschr. Kryst. Min., vol. 16, 1890, pp. 223, 333. 

s Zeitschr. Kryst. Min., vol. 24,1895, p. 293.

o On the formation of leucite in igneous rocks, see H. S. Washington, Jour, Geology, vol. 15, 1907, pp. 

257,357.
352 THE DATA OF GEOCHEMISTRY.

no other origin. It was often noted in eruptive rocks, but it was 

supposed to be always the result of alteration. It is now generally 

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. Lindgren,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 6 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. Coleman.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.

1 Am. Jour. Sci., 3d ser., vol. 45,1893, p. 286. 

2 Jour. Geology, vol. 4,1896, p. 679.

a Idem, vol. 5, 1897, p. 684.

* Sixteenth Ann. Kept. U. S. Geol. Survey, pt. 2,1895, p. 36.

6 Am. Jour. Sci., 4th ser., voi: 6,1898, p. 182. 

e 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.

»W. C. Brogger, Zeitschr. Kryst. Min., vol. 16,1890, p. 199.

10 See A. Sauer, Zeitschr. Deutsch. 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. Rept. Geol. Survey Arkansas, 1890, vol. 2, p. 267; E. Hussak, 

Neues Jahrb., 1S90, pt. 1, p. 166; and E. Scacchi, Rendiconti Accad. Napoli, vol. 24, p. 315.
BOCK-FORMING MINERALS. 353 

THE NEPHELITE GROUP.

Nephelite or elseolite. Hexagonal. Simplest empirical formula, 

NaAlSi04 . Corresponding molecular weight, 142.5. Specific gravity, 2.55 to 2.65. Molecular volume, 54.8. Normally white or colorless; often tinted yellow, gray, greenish, or reddish by impurities. 

Hardness, 5.5 to 6.

Kaliophilite or pliacelite. Hexagonal. Composition, KAlSi04 . 

Molecular weight, 158.6. Specific gravity, 2.5 to 2.6. Molecular 

volume, 6.1. Colorless. Hardness, 6.

Eucryptite. Hexagonal. Composition, LiAlSiO4 . 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 inthe normal orthosilicate. This supposition is put in more definite 

shape hy H. W. Foqte 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 canerinite, 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 mixcrystals 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 . This equivalency of nephelite and 

kaliophilite is well shown by an experiment of J. Lemberg.3 He 

heated elseolite one hundred hours to 200° with a solution of potassium 

silicate, and obtained an amorphous product having the composition 

KAlSi04 .

1 Am. Jour. Sci., 4th ser., vol. 31, 1911, p. 25. Other recent discussions of the constitution of nephelite 

are by J. Morozewicz, Bull. Acad. Sci. Cracow, 1907, p. 958; and Silvia Hillebrand, Sitzungsb. Akad. Wien, 

vol. 99, pt. 1,1910.

2 Jour. Chem. Soc., vol. 98, pt. 2,1910, p. 1078. Abst. from Rend. Accad. sci. fls. mat., Napoli, 1910. 

'Zeitschr. Deutsch. geol. Gesell., vol. 37,1885, p. 966.

101381° Bull. 491 11 23
354 THE DATA OF GEOCHEMISTRY.

P. Hautefeuille l prepared an artificial nephelite by fusing a mixture of silica and sodium aluminate with a flux of lithium vanadate. 

Fouque" and Levy 2 obtained the mineral more directly by fusing its 

constituents together, and so, too, did C. Doelter.3 Doelter's preparation agreed closely with the empirical formula NaAlSi04 . According to Fouque" and L6vy, nephelite is one of the minerals which crystallize most easily from fusion. S. Meunier 4 prepared nephelite less 

simply, by fusing silica, alumina, and soda with cryolite; and A. 

Duboin 5 effected the synthesis of kaliophilite when potassium fluoride, alumina, and silica or potassium fluosilicate were fused together. 

By similar processes Doelter 6 obtained both nephelite and kaliophilite. C. and G. Friedel 7 converted muscovite into nephelite by heating with a 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 8 when kaolin 

and dry sodium carbonate were heated together, and a similar result 

was reached by A. Gorgeu 9 and P. G. Silber. 10 When Gorgeu heated 

kaolin with potassium iodide, a salt like kaliophilite was formed. In 

these reactions the temperature was kept below that at which the 

materials would sinter together.

Nephelite is rarely found except in igneous rocks.11 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 an 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. 12 In a

nepheline syenite from an island off the coast of Guinea, A. Lacroix 13 

found crystals of sodium fluoride, NaF. This new mineral species 

he named villiaumite.

Nephelite and elseolite are peculiarly subject to alteration. 14 Natrolite, analcite, hydronephelite, thomsonite, sodalite, muscovite, and 

kaolin are among the products thus formed. Eucryptite also alters

1 Cited by Fouqu6 and LeVy, loc. cit.

a Synthese des mine'raux et des roches, p. 155.

s Zeitschr. Kryst. Min., vol. 9,1884, p. 321.

* Compt. Rend., vol. Ill, 1890, p. 509.

B Idem, vol. 115,1892, p. 56.

6 Neues Jahrb., 1897, pt. 1, p. 1.

i Compt. Rend., vol. 110,1890, p. 1170.

e Liebig's Annalen, vol. 194,1878, p. 5.

9 Annales chim. phys., 6th ser., vol. 10,1887, p. 145. 

J° Ber. Deutsch. chem. Qesell., vol. 14,1881, p. 941.

» Nephelite is reported by Max Bauer (Neues Jahrb., 1896, pt. 1, p. 85; 1897, pt. 1, p. 258) in certain 

crystalline schists, and also associated with chlorite in jadeite.

12 See the experiments of J. Morozewicz, Mln. pet. Mitt., vol.18,1898, pp. 1,105. Compare also J. Lenar6i6, 

Centralbl. Min., Geol. u. Pal., 1903, pp. 705,743. 

i» Compt. Rend., vol. 146,1908, p. 213. 

" See W. C. BrSgger, Zeitschr. Kryst. Min., vol. 16,1890, pp. 223 et seq.
ROCK-FORMING MINERALS. 355

into muscovite.1 This indicates that the simplest empirical formulae of the nephelite minerals should be tripled.

THE CANCRINITE-SODALITE GROUP.

Cancrinite. Hexagonal. Composition uncertain, but probably 

best represented by the formula Al3Na4HCSi3O15 . Corresponding 

molecular weight, 511.5. Specific gravity, 2.4. Molecular volume, 

213. tDolor commonly yellow, but also white, gray, greenish, bluish? 

or reddish. Hardness, 5 to 6.

Sodalite.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, Al3Na3CaSSi3016 , but varying in the 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 hauynite, but 

without calcium, Al 3Na5SSi3016 . 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 cancrinite 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 6 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 was replaced by other salts; but the new substances differed from 

the natural minerals in containing water of crystallization.7 A discussion of these salts, however, would lead us too far afield.

i See G. J. Brush and E. S. Dana, Am. Jour. Sci., 3d ser., vol. 20,1880, p. 266.

3 A variety of sodalite containing some sulphur has been named hackmannite by L. H. Borgstrom, 

Zeitschr. Kryst. Mln., vol. 37, 1903, p. 284. A sodalite from Monte Somma containing molybdenum Is 

described by F. Zambonini, Mineralogia vesuviana, p. 214, under the name molybdosodalite.

» Bull. U. S. Geol. Survey No. 125,1895, pp. 22-24.

< Zeitschr. Kryst. Min., vol. 18,1891, p. 209.

» Zeitschr. Deutsch. geol. Gesell., vol. 37,1885, p. 969.

fl Mineralchemische Studlen, Dorpat, 1891.

' A "chromate sodalite," containing NajCrO*, has lately been described by Z. Weyberg, Centralbl. Min., 

Geol. u. Pal., 1904, p. 727. It differs from the hydrated compound prepared by Thugutt.
356 THE DATA OF GEOCHEMISTRY.

An artificial cancrinite was obtained by Lemberg 1 when alumina, 

sodium silicate, and sodium carbonate solution were heated together 

under pressure; and also by the action of sodium carbonate, fused in 

its waters of crystallization, upon elseolite.2 Labradorite, heated to 

215° with sodium carbonate solution, also gave him cancrinite.3 C. 

and G. Friedel 4 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 carbpnate, a hydrous noselite was 

formed.5 The same authors obtained sodalite by treating muscovite 

at 500° with sodium chloride and caustic soda.6 Lemberg 7 produced 

sodalite by fusing nephelite with common salt; and the fusion of 

elseolite or sodalite with sodium sulphate gave noselite.8 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 9 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 0 .10 Sodalite, then, has been derived by artificial 

means from elseolite, muscovite, and kaolin. It was also obtained by 

Z. Weyberg n 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 12 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 gave a compound having the formula already assigned to sodalite; elseolite, 

similarly treated, yielded a substance richer in chlorine. Morozewicz concludes that two kinds of sodalite exist; to one he gives 

the formula 2(Na2Al2Si208 )-)-NaCl, while the other agrees with 

3(Na2Al2Si208) + 2NaCl.

1 Zeitschr. Deutsch. geol. Gesell., vol. 35,1883, p. 593.

«Idem, vol. 37,1887, p. 963.

8 Idem, vol. 39,1887, p. 559. For a recent discussion of the constitution of cancrinite see Thugutt, Neues 

Jahrb., 1911, pt. 1, p. 25.

< Bull. Soc. min.. vol. 14,1891, p. 71.

B Idem, vol. 13,1890, p. 238.

«Compt. Rend., vol. 110,1890, p. 1170.

' Zeitschr. Deutsch. geol. Gesell., vol. 28,1876, p. 602.

s Idem, vol. 35,1883, p. 590.'

»Neues Jahrb., Beil. Bd. 9,1894-95, p. 576. 

10 Mineralchemische Studien, p. 18. 

u Centralbl. Min., Geol. u. Pal., 1905, p. 717. 

w Min. pet. Mitt.. vol. 18,1898, pp. 128-147.
EOCK-FOBMING MINERALS. 357

Cancrinite occurs only in elseolite syenite and allied rocks, closely 

associated with nephelite and sodalite. W. Ramsay and E. T. 

Nyholm x 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 hydronephelite 

and natrolite. . Hatiynite 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 12 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.

Hypersthene. 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 MgSi03 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. 

DaubrSe 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 the 

melts. He also prepared the same substance by fusing olivine with 

silica, and he found that when serpentine was melted it broke down 

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 6 produced a silicate which he

1 Bull. Comm. geol. Finland, vol. 1,1895, p. 1. }

2 See W. C. Brogger, Zeitschr. Kryst. Min., vol. 16,1890, p. 240; also L. Saemann and F. Pisani, Annales 

Chim. phys., 3d ser., vol. 07,1863, 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 Tenerifle has been described by H. Preiswerk, Centralbl. Min., Geol. u. 

Pal., 1909, p. 393.

4 Annales chim. phys., 3d ser., vol. 33,1851, p. 58.

6 Compt. Rend., vol. 62,1866, pp. 200, 369, 660.

8 Annales chim. phys., 4th ser., vol. 4,1865, p. 174.
358 THE DATA OF GEOCHEMISTRY.

identified with enstatite, by dissolving amorphous silica in molten 

magnesium chloride, and S. Meunier 1 effected its synthesis by acting 

on metallic magnesium with silicon chloride and water vapor.

Later investigations, however, by F. Fouque and A. Michel LeVy,2 

and also by J. H. L. Vogt,3 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 4 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,5 it has been found that magnesium metasilicate exists in 

four modifications, two being pyroxenes and two amphiboles. The 

monocUnic pyroxene is formed whenever a melt having its composition is allowed to crystallize at temperatures a little below its melting 

point, 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. Themonoclinic pyroxene, then, is the most stable form of magnesium 

metasilicate.

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.

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,6 the orthorhombic pyroxenes separate from metasilicate magmas when the ratio 

Mg + Fe : Ca is 3 : 1 or greater. Both species undergo alteration, 

through hydration, into talc 7 and serpentine. Bastite is an alteration product of this kind, having the composition of serpentine.

Wollastonite. Monoclinic. Composition, CaSi03 . Minimum molecular weight, 116.5. Specific gravity, 2.85. Molecular volume, 40.5. 

Color, white, often tinted by impurity. Hardness, 4.5 to 5.

i Compt. Rend., vol. 90.1880, p. 349; vol. 93,1881, p. 737.

' Synthese des minfiraux et des roches, 1882.

a Mineralbildung in Schmelzmassen, 1892> p. Tl.

«Loc. cit.

6 Am. Jour. Sci., 4th scr., vol. 22,190G, p. 385.

8 Min. pet. Mitt., vol. 18,1898, p. 110.

1 See C. H. Smyth, School of Mines Quart., vol. 17,1896, p. 333.
BOCK-FORMING MINEEALS. 359

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, 1 and has been 

repeatedly observed in slags. 2 Wollastonite has also been found in 

slags, but rarely. 3 E. Hussak,4 however, by fusing and slowly cooling a glass containing silica, soda, lime, and boric acid, obtained 

crystals of wollastonite. C. Doelter 5 also effected the synthesis of 

wollastonite by fusing calcium metasilicate with sodium fluoride.

According to E. T. Alien and W. P. White,6 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 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,7 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 

of contact metamorphism, especially in limestones. It occurs also in 

feldspathic schists. H. Wulf 8 has described a rock from Hereroland, Africa, which consisted of wollastonite and diopside in nearly 

equal proportions. The alteration of wollastonite to ordinary pyrox- 

.ene has been reported by C. H. Smyth.9 The secondary mineral 

pectolite, HNaCa2Si309, is regarded as a derivative of wollastonite.

Diopside. Monoclinic. Composition, CaMgSi206 . 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, CaFeSi2O6 . Molecular 

weight, 248.8. Specific gravity, 3.5 to 3.6. Molecular volume, 70.- 

Color, grayish green to black. Hardness, 5 to 6.

'See L. Bourgeois, Bull. Soc. min., vol. 5,1882, p. 13; A. Gorgeu, idem, vol. 10,1887, p. 273; and C. Doeltor, Neues Jahrb., 1886, pt. 1, p. 119.

"See J. H. L. Vogt, Mineralbildung in Schmelzmassen, 1892, pp. 34-80.

3See Vogt, loc. cit., and P. Heberdey, Zeitschr. Kryst. Min., vol. 26,1896, p. 22.

'Zeitschr. Kryst. Min., vol. 17,1890, p. 101.

B Min. pet. Mitt., vol. 10,1888, p. 83.

«Am. Jour. Sci., 4thser., vol. 21,1906, p. 89. See also A. L. Day, E. S. Shepherd, and F. E. Wright, idem, 

vol. 22, p. 265. The synthetic wollastonite reported by L. v. Szathmary (Foldt. Kozl., vol.39,1909, p. 314) 

was the pseudomineral. See B. Mauritz, idem, p. 505.

'Prefatory note to the memoir by Alien and White.

8Min. pet. Mitt., vol. 8, 1887, p. 230.

»Am. Jour. Sci., 4th ser., vol. 4,1897, p. 309.
360 THE DATA OF GEOCHEMISTRY.

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 MnSi03 and ZnSi03 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 be 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. 1 A. Daubre"e, 2 on heating water to incipient redness in a glass tube, obtained crystals of diopside. G. Lechartier 3 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 4 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,5 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 

mineral was 3.275, and the melting point 1,380°. 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 diallage is expecially 

characteristic of gabbro. They also occur as secondary minerals. 

R. Brauns 6 has observed the variety salite, as formed in a picrite by 

the action of aqueous solutions upon olivine and plagioclase.

Acmite or xgirite Monoclinic. Normally NaFe'"Si 206 , 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, NaAlSi 206 . 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, LiAlSi 206 . 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.

1 See citations in L. Bourgeois, Reproduction artificielle des mine'raux, pp. 115-116; and Fouqu<5 and 

LeVy, Synthese des mine>aux et des roches, pp. 102-103. Also G. J. Brush, Am. Jour. Sci., 2d ser., vol. 

39, 1865, p. 132.

2 Etudes synthe'tiques de geologic exp6rimentale, pp. 159-176.

3 Compt. Rend., vol. 67,1868, p. 41. Compare A. Gorgeu, Bull. Soc. min., vol. 10,1887, pp. 273, 276. 

* Min. pet. Mitt., vol. 18,1898, pp. 123 et seq. See also J. H. L. Vogt, Die Silikatschmelzlosungen, pt. 1. 

1903, pp. 28-49.

6 Am. Jour. Sci., 4th ser., vol. 27,1909, p. 1. 

"Neues Jahrb., 1898, pt. 2, p. 79.
ROCK-FORMING MINERALS. 361

These alkali pyroxenes, as they are often called, are interesting 

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,1 and more exhaustively by G. J. Brush and E. S. Dana,2 

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. 3 C. Doelter,4 however, from the fusion of an artificial mixture of the oxides, obtained some acmite. H. Backstrom5 

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 6 also obtained acmite by fusing a mixture of the composition 2Si02 + Fe203 + 

Na2 0 with a large excess of sodium chloride. According to J. Morozewicz,7 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.

Acmite is a mineral of eruptive rocks, generally of those which 

contain leucite or nephelite. It is especially, common in elsBolite 

syenite. Concerning the petrologic relations of jadeite less is known; 

but S. Franchi 8 has identified the mineral as an essential constituent 

of certain eruptive rocks in Piedmont. Acmite or aegirite, according 

to W. C. Brogger,9 alters into analcite. J. Lemberg, 10 by heating

1 Ann. New York Acad. Sci., vol. 1,1879, p. 318. 

8 Am. Jour. Sci., 3d ser., vol. 20,1880, p. 257. 

s M. VuCnik, Centralbl. Min., Geol. u. Pal., 1904, p. 309. 

< Neues Jahrb., 1897, pt. 1, p. 16. 

6Bull. Soc. Min., vol. 16,1893, p. 130. 

»Centralbl. Min., Geol. u. Pal., 1905, p. 717. 

7 Min. pet. Mitt., vol. 18,1898, p. 123.

8 Eendiconti Accad. Lincei, vol. 9, pt. 1,1900, p. 349. On the jadeiteof Upper Burma, see A. W. G. Bleeck, 

Zeitschr. prakt. Geologie, 1907, p. 341.

8 Zeitschr. Xryst. Min., vol. 16,1890, p. 333. Broge;er cites many references to the literature of acmite. 

10 Zeitschr. Deutsch. geol. Gesell., vol. 39,1887, p. 584.
362 THE DATA OF GEOCHEMISTRY.

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.

Augite. 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 oxide 

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 MgAl2Si06 , and may represent the aluminous constituent of the nonalkaline augites. When alkalies are present they 

probably represent molecules analogous to or identical with acmite 

and jadeite.

The following analyses of rock-forming augite 1 were all made in 

the laboratory of the United States Geological Survey:

Analyses of augite.

A. From nepheline basalt, Black Mountain, Uvalde quadrangle, Texas. W. F. Hillebrand analyst. 

B. From dolerite, near Valmont, Colorado. Analyzed by L. G. Eakins. 

. C. From tinguaite, Two Buttes, Colorado. Analyzed by Hillebrand. 

D. From granite, Silver Cliff, Colorado. Eakins, analyst.

E. From a dyke, Silver Cliif. Eakins, analyst.

F. From basalt, Mount Taylor region, New Mexico. Analyzed by T. M. Chatard.

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

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

A1208 ........................ OA---. .....................

Fea08 --- -- .-.-. -- - - -

FeO... ....... ................

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

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

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

Na20........................

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

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

p o

Sfr::.v:.:::::::::::::::::::

A

45. 23

4.28

7.73

2.95

4.07

.07

12.25

23.37

.47

.12

.05

none

.37

300. 96

B

49.10

7.95

8.30

12.37

22.54

trace

trace

100. 26

c

47.54

3.00

4.14

trace

5.64

6.42

.36

10.05

21.57

1.38

.12

trace

100.22

D

48.72

9.27

3.77

6.34

.34

14.67

16.79

.19

.18

100. 27

E

54.87

6.34

2.88

4.61

.14

14.47

15.87

.28

.31

99.77

F

47.06

1.82

7.77

trace

1.30

8.15

.20

13.52

19.33

.33

.11

trace

.06

.20

99.85

iFrom Bull. U. S. Geol. Survey No. 419,1910, pp. 262, 263.
KOCK-FORMING MINERALS. 363

Augite is a common mineral in slags, 1 and is easily produced from 

its constituents by simple fusion.2 It was repeatedly obtained by 

Fouque" and LeVy,3 both by itself and in association with other minerals, in their classic experiments upon the synthesis of rocks. J. 

Morozewicz* also has found both ordinary augite and the alkaline 

varieties in the products yielded by his artificial magmas. The molecule RAl2Si00 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. 5 Biotite and clinochlore 

also yield it among the products of their thermal decomposition. 6 

C. Doelter 7 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 RAl2Si06 . According to

J. Lenar6ic,8 magnetite and labradorite, fused together, yield augite. 

So, too, does hedenbergite when fused with anorthite, albite,9 or 

corundum. 10

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-caUed zircon pyroxenes, rosenbuschite, 

lavenite, wohlerite, and hiortdahlite are, found in the elaeolite 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 Fe2Si309 . It has been found not only as a natural 

mineral, but also as a furnace product in slag. 11

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/2 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

1 See J. n. L. Vogt, Mineralbildung iri Schmelzmassen, p. 34.

2 For early syntheses, see Fouqu6 and L6 vy, Synthese des minfiraux et des roches, p. 102. 

8 Op. cit., pp. CO, 67, 105.

 Min. pet. Mitt., vol. 18, 1898, pp. 107, 113, 120, 123, 124.

6 C. Doelter, Allgem. chem. Mineralogie, pp. 182,183.

«Doelter, Neues Jahrb., 1897, pt. 1, p. 1.

1 1dem, 1884, pt. 2, p. 51.

BCentralbl. Min., Geol. u. Pal., 1903, pp. 705, 743.

 M. Vu6nik, idem, 1904, pp. 300, 342.

10 B. Vukits, idem, 1904, p. 705.

11 See L. Buchrucker, Zeitschr. Kryst. Min., vol. 18, 1891, p. 626.

"See IT. Ries, Ann. New York Acad. Sci., vol. 9, 1896-97, p. 124, in an important memoir upon the 

pyroxenes of New York.
364 THE DATA OF GEOCHEMISTRY.

marginal zones derived from olivine. 1 Diallage and hypersthene 

rocks alter into amphibolites.2

NOTE. For theoretical discussions upon the constitution of the pyroxenes see G. 

Tschermak, Jahrb. K.-k. geol. Reichsanstalt, vol. 21, 1871, Min. pet. Mitth., p. 17. 

C. Doelter, Min. pet. Mitt., vol. 2, 1879, p. 193. F. W. Clarke, Bull. U. S. Geol. 

Survey No. 125, 1895. J. W. Ketgers, Zeitschr. physikal. Chemie, vol. 16, 1895, 

p. 614. P. Mann, Neues Jahrb., 1884, pt. 2, p. 172. A. Merian, idem, Beil. Bd. 3, 

1884, p. 252. The literature upon this subject is very voluminous.

THE AMPHIBOLES.

Anthophyllite. Orthorhombic. Composition like enstatite or 

bronzite (MgFe) Si03 , with the magnesium silicate predominating. 

Specific gravity, 3 to 3.2. Color, gray, brown, green, and intermediate 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.3

Tremolite. Monoclinic. Composition, CaMg3Si4O12 . 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.4

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, FeSiO3 alone. 5 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

1 See G. H. Williams, Am. Jour. Sci., 3d ser., vol. 31,1886, p. 35, and F. D. Adams, Am. Naturalist, vol. 

19,1885, p. 1087. Williams gives a number of references to alterations of this kind.

2 Williams, Am. Jour. Sci., 3d ser., vol. 28,1884, p. 258.

3 An.iron anthophyllite, FeSiOa, associated with the fayalite of Rockport, Massachusetts, has been 

described by C. H. Warren, Am. Jour. Sci., 4th ser., vol. 16, 1903, p. 337.

4 See G. P. Merrill, Proc. U. S. Nat. Mus., vol. 18,1896, p. 281, for a good summary of our knowledge of 

asbestos.

6 A. C. Lane and F. F. Sharpless (Am. Jour. Sci., 3d ser., vol. 42, 1891, p. 505) have applied the name 

griinerite to a ferromagnesian amphibole like cummingtonite.
BOCK-FORMING MINERALS. 365

iron regions near Lake Superior actinolite-magnetite schists are 

common. 1

Anthophyllite, tremolite, and actinolite alter easily into talc, serpentine, and calcite. The reverse alteration, of talc into anthophyllite, has been reported by Genth. 2 Uralite, which has ordinarily the 

composition of actinolite, is an amphibole derived by alteration from 

similarly constituted pyroxenes. 3

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. 4 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.

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

TiOa .........................

AloOo........................

FcO

Fpf)

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

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

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

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

NaaO........................

H20..........................

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' 

0.1

100. 45

F

45.79

1.20

11.37

.42

.42

.39

2] 11

12.71

1.69

2.51

.67

2.76

101. 04 

1.16

99.88

1 See W. S. Bayley, Am. Jour. Sci., 3d ser., vol. 46,1893, p. 176. Also C. R. Van Hise, C. K. Leith, and 

others, in Mon. U. S. Geol. Survey, vol. 28,1897; vol. 43,1903.

2 Proc. Am. Philos. Soc., vol. 20,1882, p. 393.

s On the theory of uralitization see L. Dnparc and T. Hornung, Compt. Rend., vol. 139, 1904, p. 223. 

See also Duparc, Bull. Soc. min., vol. 31,1908, p. 50. 

< Am. Jour. Sci., 4th ser., vol. 23,1907, p. 23.
366 THE DATA OF GEOCHEMISTKY.

The synthesis of hornblende was first effected by K. Chrustschoff. 1 

He heated a solution containing dialyzed silica, alumina, and ferric 

hydroxide, with some ferrous hydroxide, magnesium hydroxide, and 

lime water, for three months to 550° in a closed digester, and obtained 

crystals of amphibole. C. Doelter,2 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,3 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,4 when anthophyllite or hornblende is fused, 

a pyroxene, sometimes with olivine, is formed. According to A. 

Lacroix,5 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 6 and B. Kolenko. 7

1 Compt. Rend., vol. 112,1891, p. 677.

2 Neues Jahrb., pt. 1, p. 1,1897.

« Am. Jour. Sci., 4th ser., vol. 22,1906, p. 385.

«Zeitschr. Deutsch. geol. Oesell., vol. 37,1885, p. 10.

6 Mingralogie de la France, vol. 1,1893-1895, pp. 668-669. 

« Mln. pet. Mitt., vol. 4,1882, p. 450.

7 Neues Jahrb., pt. 2,1885, p. 90.
HOCK-FORMING MINERALS. 367

Ordinarily, the constitution of the hornblendes is supposed to be 

analogous to that of augite, metasilicates of the form RSi03 being 

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 formula 

of diopside, MgCaSi206, and tremolite, CaMg3Si 4012 . 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 R8$i 8024 

in the pyroxene series and R4Si 4012 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 1 has sought to explain the relations between the two 

groups of minerals upon the supposition that they are mixtures of 

the two classes of salts just named. There are still other interpretations of the hornblendes. R. Scharizer 2 regards them as mixtures of 

actinolite with an orthosilicate isomeric with garnet, R"3R'"2Si3012 , 

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 RAl2Si00 . The 

synthesis of such, a compound, or its discovery as an actual mineral 

would go far toward settling the constitution of this important 

group.

An interpretation of the amphiboles quite unlike that of Tschermak 

has been proposed by S. L. Penfield and F. C. Stanley. 8 They assume 

the existence in them of bivalent molecules, A12OF2 , A120(OH) 2 ,

1 Am. Jour. Sci., 3d sen, vol. 38,1889, p. 154. See also F. W. Clarke, Bull. U. S. Geol. Survey No. 125, 

1895.

2 Neues Jahrb., pt. 2,1884, p. 143. '

8 Sitzungsb. Akad. Wlen, vol. 85, pt. 1,1882, p. 153. See also H. Haefcke, Doct. Dlss., Gottingen, 1890.

«Am. Geologist, vol. 21,1898, p. 370.

6 Am. Jour. Sci., 4th ser., vol. 1,1896, p. 210. "Hostlngsite."

8 Idem, vol. 23, 1907, p. 23. Other discussions of the constitution of the amphiboles are by S. Krcutz, 

Sitzungsb. Akad. Wlen, vol. 117, pt. 1,1908/p. 877, and G. Murgoci, Bull. Dept. Geology, Univ. California, 

Vol. 4,1906, p. 359.
368 THE DATA OF GEOCHEMISTRY.

A1203R", and Al204R"Na2, and also the univalent group MgF, in 

order to account for fluorine, water, and alumina. All of the amphiboles are then formulated as polymetasilicates.

All of these interpretations of the amphibole group need careful 

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 tremolite 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. How far this 

conclusion may affect the formulae of the minerals can be determined 

only after a careful revision of all the trustworthy hornblende 

analyses, but it will probably lead to simplification.

Glaucophane.^-M.on.oclinic. Normally NaAlSi206 .(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, 2NaFeSi206 .FeSi03 . Color, 

black.

Crocidolite. Composition, NaFeSi206 .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 

and glaucophane.

Arfvedsonite. Monoclinic. The composition is approximately 

4Na2Si03 + 13FeSi03 + 3CaSi03 + Fe''Al2Si06 , but probably variable. 

Specific gravity, 3.45. Color, black. Hardness, 6.

Barkevikite. Intermediate between arfvedsonite and hornblende.4 

Color, black. Specific gravity, 3.43.

jEnigmatite. Triclinic. Essentially a metasilicate of sodium and 

ferrous iron, but with titanium replacing a part of the silicon, and a 

small admixture of the basic salt RFe'"2Si06 . 5 Specific gravity, 3.80. 

Color, black.

1 Am. Jour. Sci., 4th ser., vol. 26,1908, p. 101.

2 Sitzungsb. Akad. Wien, vol. 100, pt. 1,1891, p. 176.

a Bull. Dept. Geology Univ. California, vol. 1,1894, p. 181.

< For a discussion of the composition of barkevikite, see W. C. Brogger. Zeitschr. Kryst. Min., vol. 15, 

1890, p. 412.

6 See Brogger, op. cit., pp. 428-429. See also J. Soellner, Neues Jahrb., Beil.'Bd. 24,1907, p. 475, who has 

described a new mineral, rhoenite, allied to senigmatite.
ROOK-FORMING MINERALS. 369

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 MgSi03 in addition to the aluminous compounds. None of them has been prepared 

synthetically, and, like the other amphiboles, they yield pyroxenes 

upon fusion.1

Glaucophane occurs chiefly in a series of glaucophane schists and in 

eclogite. 2 It has also been observed in some eruptive rocks. It alters 

into chlorite, feldspar, and hematite.3 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. 4

Arfvedsonite and barkevikite occur chiefly in augite and elseolite 

syenites, also in a granite. vEnigmatite is known chiefly from the 

sodalite syenite of Greenland; but cossyrite, which is probably the 

same mineral, was found in a rhyolite lava. Arfvedsonite alters into 

acmite and lepidomelane,5 and so also does barkevikite.6

Kaersutite from Greenland and linosite from the island of Linosa, 

east of Tunis, are aluminous amphiboles rich in titanium. In linosite H. S. Washington 7 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.

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

1 See Brogger, op. cit, p. 410, with reference to arfvedsonite. C. Doelter (Min. pet. Mitt., vol. 10, 1888, 

p. 70) fused glaucophane with sodium fluoride and magnesium fluoride and obtained a product resembling 

acmite.

a See K. Oebbeke, Zeitschr. Deutsch. geol. Gesell., vol. 38, p. 634,1886, forasummary of occurrences and 

bibliography. Also H. S. Washington, Am. Jour. Sci., 4th ser., vol. 11, 1901, p. 35; G. F. Becker, Mon. 

U. S. Geol. Survey, vol. 13,1888, p. 102; and H. Eosenbusch, Sitzungsb. Akad. Berlin, 1898, 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. 183.

«L. Colomba, Zeitschr. Kryst. Min., vol. 26,1896, p. 215.

«On riebeckite rocks, see G. T. Prior, Min. 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. 20,19Q5, p. 133. According to Murgoci, riebeckito 

forms only from persilicic magmas. Riebeckite rocks from Oklahoma are described by A. F. Rogers in 

Jour. Geology, vol. 15,1907, p. 283.

6 W. C. Brogger, Zeitschr. Kryst. Min., vol. 16,1900, pp. 407-410; also N. V. Ussing, idem, vol. 26,1896, 

p. 104.

«Brogger, op. cit., pp. 418-422.

' Am. Jour. Sci., 4th ser., vol. 26,1909, p. 187.

101381° Bull. 491 11 24
370 THE DATA OF GEOCHEMISTKY.

which the magnesium salt predominates, is known as olivine, chrysolite, or peridot. A variety containing a large amount of iron is called 

hyalosiderite. Hortonolite is another member of the group, containing much iron, less magnesia, and about 4.5 per cent of manganese 

oxide. The compound Mn2Si04 occurs as tephroite, and roepperiteis 

a variety containing zinc. Khebelite is intermediate between fayalite 

and tephroite. All of these minerals are represented by the general 

orthosilicate formula K2Si04 . 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, CaMnSi0 4 , 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 

Daubree 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 

product. G. Lechartier 9 fused silica and magnesia with calcium 

chloride, and P. Hautefeuille 10 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

1 See A. Damour, Bull. Soc. min., vol. 2,1879, p. 15; and L. Brugnatelli, Zeitschr. Kryst. Min.,. vol. 39,1904, 

p. 209.

2 See Fouque" and Levy, Synthese des mineraux et des roches, p. 96; L. Bourgeois, Reproduction artiflcielle 

des mineraux, pp. 108-110; Vogt, Mineralbildung in Schmelzmassen, p. 8. A. Stelzner and H. Schulze 

(Neues Jahrb., 1882, pt. 1, p. 170) have described a slag containing a zinc-bearing fayalite; and H. Laspeyres 

(Zeitschr. Kryst. Mm., vol. 7,1883, p. 494) has reported another furnace product having the composition 

MnFe3Si3 08.

» Cited by Fouque and Levy, op. cit., p. 97.

< Bull. Soc. min., vol. 4,1881, p. 279.

6 Compt. Rend., vol. 92, 1881, p. 367.

«Annales chim. phys., 3d ser., vol. 33,1851, p. 56

' Compt. Rend., vol. 62,1866, pp. 200, 369, 660. 

' 8 Etudes synthetiques de geologic expeiimentale, p. 524.

» Compt. Rend., vol. 67,1868, p. 41.

10 Annales chim. phys., 4th ser., vol. 4,1865, p. 129.
BOCK-FORMING MINERALS. 371

enstatite or enstatite and olivine together were formed. S. Meunier,1 

by heating magnesium vapor to redness in a mixture of water vapor 

and silicon chloride, obtained both olivine and enstatite. Fayalite 

was prepared by A. Gorgeu, 2 who heated ferrous chloride with silica 

to redness in a stream of moist hydrogen. Olivine is also formed, according to C. Doelter, 3 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 

was obtained by E. T. Alien, F. E. Wright, and J. K. Clement,4 

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, 5 associated with tridymite in lithophyses of 

rhyolite and obsidian in the Yellowstone Park. A similar occurrence in the Lipari Islands is reported by Iddings and S. L. Penfield.6 At Rockport, Massachusetts, fayalite has been found in 

granite.7 Olivine is also a common constituent of meteorites, and is 

often conspicuously associated with metallic iron. As products of 

thermal metamorphism olivine and forsterite are found in limestones 

and dolomites, frequently accompanied by spinel.8 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 Jeremeef 9 has 

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 10 and B. Kolenko.11 By a reaction

i Compt. Eend., vol. 93,1881, p. 737.

a Idem, vol. 98, 1884, p. 920.

» Min. pet. Mitt., vol. 10,1888, p. 67; and Neues Jahrb., 1897, pt. 1, p. 1.

«Am. Jour. Sci., 4th ser., vol. 22,1906, p. 385.

6 Idem, 3d ser., vol. 30,1885, p. 58.

»Idem, vol. 40,1890, p. 75.

i See S. L. Penfield and E. H. Forbes, Am. Jour. Sci., 4th ser., vol. 1,1896, p. 129.

s See C. T. Clough and W. Pollard, Quart. Jour. Geol. Soc., vol. 55,1899, p. 372.

9 Zeitschr. Kryst. Min., vol. 32,1900, p. 430. 

« Min. pet. Mitt., vol. 4,1882, p. 450. 

» Neues Jahrb., 1885, pt. 2, p. 90.
372 THE DATA OF GEOCHEMISTEY.

between olivine and feldspar, according to R. Brauns, 1 a pyroxene 

can be formed. Monticellite alters into serpentine and pyroxene; 

and C. H. Warren 2 found a ferrous anthophyllite, FeSi03 , derived 

from the fayalite of Rockport.

THE MICAS.

Muscovite. Monoclinic. Composition normally Al3KH2Si3O12 . 

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 Al3KH2Sig024 . Fuchsite is a 

muscovite containing small amounts of chromium, replacing aluminum. Baddeckite 3 appears to be a muscovite containing much ferric 

iron, due to admixtures of the compound Fe3KH2Si3012 . F. W. 

Clarke and N. H. Darton 4 have described an altered mica which 

seems to be derived in part from the same ferric salt. Roscoelite is 

similar, but with nearly two-thirds of the aluminum replaced by 

vanadium.5 Sericite, margarodite, damourite, gilbertite, etc., are 

muscovites of secondary origin.

Paragonite. Monoclinic. A sodium mica, Al3NaH2Si3012 , corresponding 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-bearmg 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, Al(OH) 2 .Si3O12 .R/3 , 

is probably a derivative, by hydration, of lepidolite; but it may 

be ,an alteration of tourmaline. Polylithionite is another lithia mica 

in which the ratio Si: 0 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 cryophyllite. 

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, Al2Mg2KHSi3O12 , but 

with admixtures of the corresponding ferric and ferrous salts in

1 Neues Jahrb., 1898, pt. 2, p. 79.

2 Am. Jour. Sci., 4th ser., vol. 16,1903, p. 337.

3 G. C. Hoffman, Ann. Kept. Geol. Survey Canada, vol. 9,1896, p. 11 R. 

«Bull. U. S. Geol. Survey No. 167,1900, p, J54. 

» F. W. Clarke, idem, p. 73.
BOCK-FORMING MINEEALS. 373

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.

Phlogopite. Monoclinic. Composition variable; typical phlogopite approximates to AlMg3KH2Si3012 . 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' 'H2Si07 ; 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 

possible to be certain whether a change of that order may not have 

begun. In spite of all difficulties, however, the micas can be expressed 

by a small number of generalized formulae, which are all derivable 

from one general type, as follows :

Muscovite, R///3R/3(Si04)3 and R///3R/3(Si308)3 . 

Biotite, R///2R//2R/2(Si04)3 and R///2R//2R/2(Si308)3 . 

Phlogopite, WWW^SiOJ, and R"^R"3R'3(Si3O8)3 .

> Triclinic according to H. F. Keller and A. C. Lane, Ara. Jour. Sci., 3d ser., vol. 42, 1891, p. 499.
374 THE DATA OF GEOCHEMISTRY.

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, namely, R'" F2 .Si308R'3 in lepidolite, zinnwaldite, 

and some phlogopites, and the clintonite molecule R'"02R". 

Si3O8 .R/ 3 , with its orthosilicate equivalent R'"02R".SiO4.R' 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 hydrogen replaced by some other monad radicle. To Fouque" 

and LeVy's 4 synthesis 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 

of white mica. This transformation is instructive, for andalusite 

alters into muscovite quite readily. P. Hautefeuille and L. P. de 

Saint-Gilles 6 fused the constituents of an iron mica with potassium 

silicofluoride and found crystals resembling mica in their product. 

K. ChrustschofFs 7 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

1 Zeitschr. Kryst. Min., vol. 47,1910, p. 215. See also A. Sauer, Zeitschr. Deutsch. geol. Gesell., vol. 38, 

1886; p. 705.

2 Zeitschr. Kryst. Min., vol. 2, p. 14,1878; vol. 3,1879, p. 122.

3 Berg- u. Hiittenm. Zeitung, vol. 47, p. 197.

4 Compt. Rend., vol. 113,1891, p. 283.

5 Allgem. chem. Mineralogie, p. 207. 

8 Compt. Rend., vol. 104,1887, p. 508. 

' Min. pet. Mitt., vol. 9,1887, p. 66.
BOCK-FORMING MIFEBALS. 375

slow cooling, the mass contained a micaceous mineral, which was 

separated and analyzed. It was essentially an anhydrous biotite. 

J. Morozewicz l 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,2 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 

fluoride, 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 + Mg2Si04 , 

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 

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 

of 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 scapolites, 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 

secondary after muscovite, for it 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.3 Pressure seems to con1 Neues Jahrb., pt. 2,1893, p. 48.

2 Idem, pt. 2, 1888, p. 178; pt. 1,1897, p. 1. Also Min. pet. Mitt., vol. 10, 1888, p. 67.

»For a discussion of this alteration, see H. S. Washington, Jour. Geology, vol. 4,1896, p. 257.
376 THE DATA OF GEOCHEMISTRY.

dition its formation. Phlogopite occurs chiefly in granular Archean limestones and in serpentine; but W. Cross 1 has described 

it as a constituent of a peculiar igneous rock, wyomingite. Chloritoid 

and ottrelite are found only in phyllitic schists,2 and are of minor 

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 3 transformed muscovite into nephelite, sodalite, 

leucite, orthoclase, and anorthite. Upon fusion, according to C. 

Doelter,4 muscovite breaks up into leucite, glass, and a substance resembling nephelite. Lepidolite and zinnwaldite :. nave in a similar 

manner. W. Vernadsky 5 observed corundum and sillimanite among 

the fusion products of mica. From the composition of muscovite a 

splitting up into water, leucite, and sillimanite may be inferred, 

according to the equation 

Al3KH2Si3012 =AlKSi2 06 + Al2Si05 + H20;

and with this the reported derivation of muscovite from leucite can 

be correlated. 6 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 7 

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 

additional, loosely combined water. From the typical ferromagnesian micas the following derivatives are thus formed:

From Al2Mg2KHSi3012 ...... Al2Mg2H2Si3012 .3H20.

From AlMg2KH2Si3012 ..... .AlMg3H3Si3012 .3H20.

From any mixture of biotite and phlogopite molecules the corresponding hydrated 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. 8

' Am. Jour. Sci., 4th ser., vol. 4,1897, p. 115.

2 See A. Cathrein, Min. pet. Mitt., vol. 8,1887, p. 331; and L. van Werveke, Neues Jahrb., 1885, pt. 1, p. 227.

s Compt. Rend., vol. 110,1890, p. 1170.

< Neues Jahrb., pt. 1,1897, p. 1.

s Cited by Morozewicz, Min. pet. Mitt., vol. 18,1898, p. 26.

«See Doelter's experiment, cited above.

' Geol. Foren. Forhandl., vol. 18,1896, p. 162.

s On the alteration products of the magnesian micas, see E. Zschimmer, Jenaische Zeitschr., vol. 32,1898, 

p. 551. On the action of water upon micas, A. Johnstone, Quart. Jour. Geol. Soc., vol. 45,1889, p. 363. For 

analyses of vermiculities, see E. S. Dana, System of mineralogy, 6th ed., pp. 664-668; also F. W. Clarke and 

E.A. Schneider, Bull. U.S. Geol. Survey No. 78,1891,; Bull. No. 90,1892. The earlier papers of J. P. Cooke 

and F. A. Genth are also important.
ROCK-FORMING MINEKAIvS. 377

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, 1 who assigns to them the 

annexed empirical formulas :

Clinochlore. ............................... .1 __,,., ,-, N . , . ~

Penninite.. ............ ............. ........ }H8(Mg,Fe)6Al2Si3018 .

Prochlorite. ............................... .H40(Fe,Mg)23AluSi13090 .

Corundophilite. ............................ .H2o(Fe,Mg) uAl8Si6048 .

Daphnite. .................................. H56Fe27Al29Si180121 .

Cronstedtite. .............................. .H6(Fe,Mg)3Fe///2Si2013 .

Thuringite. ................................ .H18Fe8(Al,Fe)8Si6041 .

Stilpnomelane. ..............................

Strigovite. ................................ .H4(Fe,Mn)2(Fe,Al)2Si2011 .

Diabantite. ................................ .H18(Mg,Fe) 12Al4Si9045 .

Aphrosiderite. .............................. .H10(Fe,Mg)6Al4Si4 02S .

Delessite. . ................................ .H10(Mg, Fe)4Al4Si4 022 .

Rumpfite. ................................ .

To these may be added the more or less uncertain minerals amesite, 

metachlorite, klementite, chamosite, epichlorite, etc.

None of the formulae given above are 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. 2 The 

simplest and most natural interpretation of the chlorites represents 

them as formed from a series of compounds parallel with those identified in the micas and vermiculites, according to the following 

scheme :

Normal micas. Vermiculites. Normal chlorites.

Al3KH2(Si04 )3 . ........................... ............................

Al2Mg2KH(Si04)3 . Al2Mg2H2 (Si04 )3 .3H20. Al2 (MgOH)4H2(Si04 )3 .

AlMg3KH2 (Si04 )3 . AlMg3H3 (Si04 )3 .3H20. Al(MgOH)8H3(Si04 )3 .

A102Mg.Si04 .R'3 . A102Mg.Si04R'3 .3H20.

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 interme1 System of mineralogy, Cth ed., p. 643.

2 See G. Tschermak, Sitzungsb. Akad. Wien, vol. 99, pt. 1 , 1890, p. 174; vol. 100, pt. 1, p. 29. R. Brauns, 

Neues Jahrb., pt. 1 , 1894, p. 205, and Chemlsche Mineralogie, p. 221. F. W. Clarke, Bull. U. S. Geol. Survey No. 125, 1895, p. 53. An earlier discussion by Clarke, on different lines, is given in Bull. U. S. Geol. 

Survey No. 113, 1893, p. 11.
378 THE DATA OF GEOCHEMISTEY.

diate between biotite and phlogopite. Prochlorite appears to be a 

derivative of the last molecule, having the formula 

A102R'.Si04 .(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 the^ 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 evidence against 

Tschermak's theory of the chlorite group, in which the normal series 

is regarded as formed by mixtures of serpentine, H4Mg3Si209 , with 

amesite, H4Mg2Al2Si09 . 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 insoluble 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 

muscovite with 25 of chlorite, is reported by K. Dahner. 8 With

almost no change of composition, other than loss of water,. it was 

transformed into a mixture of andalusite and biotite.

THE MELILITE GROUP.

Melilite. Tetragonal. The composition is uncertain, but near 

Al2Ca6Si5019; with Fe"' replacing some Al, and Mg or Na replacing a part of the Ca. The mineral is very variable in composition. 

Specific gravity, 2.9 to 3.1. Hardness, 5. Color, white, yellow, 

greenish yellow, brown.

i For the other chloritic minerals see F. W. Clarke, Bull. U. S. Geol. Survey No. 125,1895, pp. 53-55. 

8 For a complete discussion of pseudomorphous chlorite after pyrope, see J. Lemberg, Zeitschr. Deutsch. 

geol. Gesell., 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. 

6 Neues Jahrb., pt. 1,1897, p. 1. 

«Idem, pt. 2,1897, p. 156.
KOCK-FORMING MINERALS. 379

Gehlenite. Tetragonal. The normal composition is probably 

Al2Ca3Si2O10. Corresponding molecular weight, 391.3. Specific 

gravity, 3. Molecular volume, 130.4. Hardness, 5.5 to 6. Color, 

grayish green to brown.

Akermannite. Tetragonal. Composition, Ca4Si3 010, with about 

one-third of the calcium replaced by magnesium. According to A. L. 

Day and E. S. Shepherd * 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 is reported by F. Zambonini 2 as occurring in calcareous blocks 

at Monte Somma.

These three isomorphous silicates are closely related to one another. 

J. H. L. Vogt 3 regards gehlenite and akermannite as the two independent species, which, isomorphously commingled, form the variable melilite. This view is plausible, but not universally accepted. It

is not at all certain that ideally pure melilite or gehlenite has been 

found and analyzed. 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.

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 

Fouqu6 and LeVy 8 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. 

Fouqu6 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

1 Am. Jour. Sci., 4th ser., vol. 22,1906, p. 265.

a Mineralogia Vesuviana, p. 255.

8 Mineralbildung in Schmelzmassen, 1892, pp. 96-176. See also G. Bodlander, Neues Jahrb., pt. 1,1893, 

p. 15; and F. Fouqu6, Bull. Soc. min., vol. 23,1900, p. 10. Also a more recent discussion by Vogt, Die 

Silikatschmelzlosungen, pt. 1, 1903, p. 49. F. Zambonini (Zeitschr. Kryst. Min., vol. 41, 1906, p. 226) 

has advanced strong arguments against Vogt's hypothesis.

4 See L. Bourgeois, Reproduction artiflcielle des mine'raux, p. 123. J. H. L. Vogt, Mineralbildung in 

Schmelzmassen, 1892. F. Fouqufi, Bull. Soc. min., 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.

6 Min. pet. Mitt., vol. 18,1898, p. 191.

6 Bull. Soc. min., vol. 2,1879, p. 105.

' Idem, vol. 23,1900, p. 10.

8 Neues Jahrb., pt. 1,1892, p. 53.

»Idem, pt. 2,1892, p. 73.

10 Annales chim. phys., 5th ser., vol. 29,1883, p. 450.
380 THE DATA OP GEOCHEMISTRY.

certain other oxides commingled in proper proportions, but could 

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. The existence of a purely calcic melilite remains to be established. 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

Alterations of melilite seem to have been little studied. A. Cathrein 5 has described pseudomorphs of pyroxene (fassaite) and grossularite after gehlenite. By heating gehlenite with a solution of 

potassium carbonate to 200°, J.Lemberg 8 obtained calcium carbonate 

and an amorphous product having the composition of a potassium 

mica.

THE GARNETS.

Grossularite. Isometric. Composition, CagA^SigO^. 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, Mg3Al2Si3O12 . Molecular weight,

404,6. Specific gravity, 3.7. Molecular volume, 109.4. Color, deep

red to nearly black.

Almandite. Isometric. Composition, Fe^Al2Sis012 . Molecular 

weight,' 499.1. Specific gravity, 3.9 to 4.2 Molecular volume, 118. 

Color, red to brown and black. Pyrope and almandite shade one into 

the other through varying mixtures of the iron and magnesium compounds.

Spessartite. Isometric. Composition, Mn3Al2Si3O12 . Molecular 

weight, 496.4. Specific gravity, 4.2. Molecular volume, 118. Color, 

red to brown.

1 Neues Jahrb., pt. 1, 1884, p. 159.

2 Idem, pt. 1,1897, p. 1.

a Annales chim. phys., 5th ser., vol. 29, 1883, p. 448. *

« For data upon melilite rocks see A. E. Tornebohm, Geol. Foren. Forhandl., vol. 6, 1882, p. 240. A. 

Stelzner, Neues Jahrb., Beil. Bd. 2, 1883, p. 369. F. D. Adams, Am. Jour. Sci., 3d ser., vol. 43, 1892,p.2C9. 

C. H. Smyth, idem, vol. 46, 1893, p. 104. The last two references deal with American occurrences.

o Mm. pet. Mitt., vol. 8, 1887, p. 400.

"Zeitschr. Deutsch. geol. Gesell., 1892, p. 237.
KOCK-FORMING MINERALS. 381

Andradite, melanite, or common garnet. Isometric. Composition, 

Ca3Fe'"2Si 3012 . Molecular weight, 509.3. Specific gravity, 3.85. 

Molecular volume, 158.2. Color, green, yellow, brown, or black.

Uvarovite. Isometric. Composition, Ca3Cr2Si 3012 . 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 Ca8 (Fe,Ti/ '') 2 (SiTi lv)3013 . 1 

The sodium garnet lagoriolite, Na6AJ 2Si3012 , 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 due 

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 

grossularite with sodium and magnesium fluorides, Doelter 5 obtained 

biotite, anorthite, meionite, olivine, and magnetite. L. Bourgeois,0 

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 

produced. The syntheses of garnet reported by several early investigators.8 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 ° 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

JR. Soltmann (Zeitschr. Kryst. Min., vol. 18,1891, p. 628) has described a melanite garnet containing 

11.01 per cent of TiOa, which should probably be partly reduced to Ti 203.

2 Min. pet. Mitt., vol. 18,1898, p. 147.

8 For systematic papers on the garnet group see W. C. Brogger and H. Backstro'rn, Zeitschr. Kryst. Min., 

vol. 18,1891,p. 209; and E. Weinschenk, idem, vol. 25,1896, p. 365.

«Neues Jahrb., pt. 1,1,884, p. 158.

sidem.pt. 1,1897, p. 1.

8 Annales chim. phys., 5th ser., vol. 29,1883, p. 458.

T Mineralbildung in Schmelzmassen, 1892, p. 187.

s See Fouque" and Levy, Synthese des rnine'raux et des roches, p. 122.

 Annaleschim. phys., 6th ser., vol. 4,1885, pp. 536,553.
382 THE DATA OF GEOCHEMISTRY.

grossularite. Fouque" and LeVy 1 report melanite as formed when 

nephelite and pyroxene are fused together. L. Michel 2 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. 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.

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 emptives, 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 3 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.

Alterations of garnet are exceedingly common. A. Cathrein,4 

describing the rocks of a single region, reports pseudomorphs after 

garnet of scapolite, epidote, oligoclase, hornblende, saussurite, and 

chlorite. Chloritic pseudomorphs are perhaps the most frequent.5 

The pyrope found in peridotite rocks is often surrounded by a zone 

or shell of altered material, to which A. Schrauf 6 has given the 

name kelyphite. It is, however, not a substance of uniform composition. The kelyphite studied by A. von Lasaulx 7 was mainly 

a mixture of pyroxenes and amphiboles. J. Mrha 8 described a 

kelyphite consisting of bronzite, monoclinic pyroxene, picotite, and 

hornblende. The pyrope from the peridotite dikes of Elliott 

County, Kentucky, described by J. S. Diller 9 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

1 Compt. Rend., vol. 87,1878, p. 962.

2 Idem, vol. 115,1892, p. 830.

3 Am. Jour. Sci., 3d ser., vol. 31,1886, p. 432. 

«Zeitschr. Kryst. Min., vol. 10,1885, p. 433.

6 See for example J. Lemberg, Zeitschr. Deutsch. geol. Gesell., vol. 27,1875, p. 531; and S. L. Penfleld 

and F. L. Sperry, Am. Jour. Sci., 3d ser., vol. 32,1886, p. 307. 

o Zeitschr. Kryst. Min., vol. 6,1882, p. 358.

i Verhandl. Naturhist. Ver. preuss. Rheinland u. Westfalen, vol. 39, pt. 2,1882, p. 114. 

s Min. pet. Mitt., vol. 19,1899, p. 111. 

<> Bull. U. S. Geol. Survey No. 38,1887.
BOCK-FORMING MINERALS. 383

of other minerals. P. Jereme'ef l has recorded pseudomorphs of 

grossularite after vesuvianite; and grossularite after gehlenite was 

observed by A. Cathrein.2

VESUVIANITE.

Tetragonal. Composition variable, and best represented by the 

general formula Al2Ca7Si6O24B/4 ; 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.3 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. 

Pseudomorphs of grossularite after vesuvianite have been reported 

by P. Jeremeef.4 When vesuvianite is fused, it breaks up into 

meionite, melilite, anorthite, and possibly a lime olivine.5

THE SCAPOLITES.

Meionite. Tetragonal. Composition, Ca4Al6Si6O25 . Molecular 

weight, 893.4. Specific gravity, 2.72. Molecular volume, 328.4. 

Colorless or white. Hardness, 5.5 to 6.

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. 6 Intermediate between them, and analogous to the plagioclase feldspars lying between 

anorthite and albite, are the following scapolites, which have received 

independent names:

Wernerite...........;............................ MegMaj to M^M^

Mizzonite or dipyre................................ MejMaa to MejMag

The reported syntheses of scapolite are not altogether conclusive. 

L. Bourgeois 7 attempted to prepare meionite by fusing together its

1 Zeitschr. Kryst. Min., vol. 31,1899, p. 505.

2 Min. pet. Mitt., vol. 8,1887, p. 400.

3 See F. W. Clarke and G. Steiger, Bull. U. S. Geol. Survey No. 262,1905. For other interpretations of 

vesuvianite see P. Jannasch and P. Weingarten, Zeitschr. anorg. Cbemie, vol. 8,1895, p. 356; M. Weibull, 

Zeitschr. Kryst. Min., vol. 25,1895, p. 1; A. Kenngott, Neues Jahrb., pt. 1,1891, p. 200; H. Sjogren, Geol. 

F6ren. Forhandl., vol. 17,1895, p. 267.

«Zeitschr. Kryst. Min., vol. 31,1899, p. 505.

B C. Doelter and E. Hussak, Neues Jahrb., 1884, pt. 1, p. 158.

o Min. pet. Mitt., vol. 7, p. 400,1886; Monatsh. Chemie, vol. 4, 1883, p. 851. Compare F. W. Clarke's 

constitutional formula in Bull. U. S. Geol. Survey No. 125,1895.

' Annales chim. phys., 5th ser., vol. 29,1883, pp. 446, 472.
384 THE DATA OF GEOCHEMISTRY.

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 1 obtained an artificial rock containing scapolite; and a 

similar experiment with eclogite also yielded the mineral. The same 

procedure with epidote and fluorides gave C. Doelter 2 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. The exact conditions which 

permit the formation of scapolites are yet to be determined.

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.3 

In Norway scapolite rocks are associated with masses of apatite, 

especially at Oedegaarden. In this instance J. W. Judd 4 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 

stresses. A. Lacroix,5 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 

L6vy 6 transformed it back again into pyroxene and labradorite.- A 

Canadian scapolite diorite has been described by F. D. Adarris and 

A. C. Lawson,7 and H. Lenk 8 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,"

> Neues Jahrb., 1897, pt. 2, pp. 133,149.

sIdem, pt. 1, p. 1.

«See F. Zirkel, Lehrbuch der Petrographie, vol. 1, 1893, p. 382. W. Salomon, Min. pet. Mitt., vol. 15, 

1895, p. 159, gives a good bibliography relative to dipyre.

«Mineralog. Mag., vol. 8,1889, p. 186.

Bull. Soc. min., vol. 14,1891, p. 16. In vol. 12,1889, p. 83, Lacroix has an elaborate monograph upon 

scapolite rocks.

« Bull. Soc. min., vol. 2,1879, p. 112.

i Canadian Rec. Sci., vol. 3,1888, p. 186.

«Neues Jahrb., 1899, pt. 1, ref. 73.
BOCK-FORMING MINERALS. 385

after scapolite are very common. Alterations into epidote, steatite, 

kaolin, and free silica are also recorded. A. Cathrein 1 has reported 

pseudomorphs of scapolite after garnet.

IOLITE.

lolite or cordierite. Orthorhombic. H2 (Mg,Fe) 4Al8Si10037 .2 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,3 who 

fused silica, magnesia, and alumina together in proper proportions. 

J. Morozewicz 4 also obtained it in his experiments upon artificial 

magmas, supersaturated with alumina, of the general formula 

RO.mAl203 .7iSi02 . 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 . 5 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.

lolite is found in nature in a great variety of rocks, including both 

metamorphic rocks and eruptives. 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.6 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 7 

consisted mainly of biotite, quartz, and iolite, with some plagioclase. 

lolite is also well known as a product of contact metamorphism. For 

example, Bucking 8 found it in sandstones which had been vitrified 

by contact with basalt; and Kikuchi 9 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,

1 Zeitschr. Kryst. Min., vol. 9, 1884, p. 378; vol. 10, 1885, p. 434.

2 Formula based upon 0. C. Farrington's analysis, Am. Jour. Sci., 3d ser., vol. 43, 1892, p. 13. M. Weibull 

(Geol. Forcn. Forhandl., vol. 22, 1900, p. 33) regards the mineral as anhydrous, and writes the formula

s Annalcs chim. phys., 5th ser., vol. 29, 1883, p. 462.

« Miu. pet. Mitt., vol. 18, 1898, pp. 68, 167. See ante, p. 321, under "Corundum."

» Neues Jahrb., pt. 1, 1894, p. 79.

« See H. Bucking, Ber. Senckenbergischen naturforsch. Gesell., Abhandl., 1900, p. 3; J. Szabd, Neues 

Jahrb., Beil. Ed. 1, 1881, p. 308; E. Hussak, Sitzungsb. Akad. Wien, vol. 87, pt. 1, 1883, p. 332; Neues 

Jahrb., pt. 2, 1885, p. 31; A. Harker, Geol. Mag., 1906, p. 176.

* Am. Jour. Sci.. 3d ser., vol. 36, 1888, p. 57. 

 8 Loc. cit.

 Jour. Coll. Sci. Japan, vol. 3, 1890, p. 313. Kikuchi also describes an alteration of the iolite into pinite.

101381° Bull. 491 11 25
386 THE DATA OF GEOCHEMISTRY.

aspasiolite, gigantolite, fahlunite, pinite, etc!., are merely altered 

iolite. 1

THE ZOISITE GROUP.

Zoisite. Orthorhombic.2 Composition, HCa-jAlgSigO^. 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.

Allanite 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 3 claimed to 

have produced zoisite by fusing 40 parts of silica with 37 of lime 

and 23 of alumina. C. Doelter, 4 upon fusing epidote powder with 

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 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.5 It 

is not at all uniform in composition.

Epidote, like zoisite, is a mineral of the crystalline schists, although 

C. R. Keyes 6 has cited evidence to show that it is a primary mineral 

in certain granites of Maryland. It is there intergrown with allanite

1 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, Bull. U. S. Geol. 

Survey No. 125, 1895, p. 83. .

2 For optical variations in zoisite, see P. Termier, Bull. Soc. min., vol. 21, 1898, p. 148; vol. 23, 1900, p. 50. 

Tormier regards the silicate HCa2R"'3Si3Oi3 as trimorphous.

a Arch. sci. phys. nat., 3d ser., vol. 25, 1891, p. 239.

.< Neues Jahrb., 1897, pt. 1, p. 1.

B 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.

e Bull. Geol. Soc. America, vol. 4, 1893, p. 305.
ROCK-FORMING MINERALS. 387

and was also observed inclosed in primary sphene. A. Michel LeVy 1 

also regards the epidote of certain Pyrenean ophites as primary. 

It is also found, according to B. S. Butler, 2 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.3

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 4 has reported piedmontite in a rhyolite from Pennsylvania and N. Yamasaki 5 

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.

Allanite is widely diffused as a primary accessory in many igneous 

rocks. J. P. Iddings and W. Cross,7 who have pointed out its 

importance, cite occurrences of allanite in gneiss, granite, quartz por- 

 phyry, diorite, andesite, dacite, rhyolite, etc. W. H. Hobbs,8 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,9 A. Lacroix, 10 G. H. Williams, 11 and others. In the 

granite of Pont Paul, France, allanite is sometimes enveloped by 

biotite. 12 W. Mackie J3 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.

1 Bull. Soc. gSol. France, 3d ser., vol. 6, p. 161.

2 Am. Jour. Sci., 4th sor., vol. 28,1909, p. 27. Butler gives many references to literature.

8 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. 46,18S3, p. 50. This paper contains many references to literature.

6 Jour. Coll. Sci. Japan, vol. 9,1897 p. 117.

« Gee B. Koto, idem, vol. 1 1887, p. 303.

i Am. Jour. Sci., 3d ser.. vol. 30,1885, p. 108.

8 Idem, vol. 38,1889, p. 223.

8 Canadian Rec. Sci., vo.. 4,1891, p, 344.

"> Bull. Soc. min., vol. 12,1889. pp. 138,157, 210.

» Bull. U. S. Geol. Survey No. 62,1890.

12 A. Michel Le>y and A. Lacroix. Bull. Soc. min., vol. 11,1888, p. 68.

is Trails. Edinburgh Geol. Soc., vol. 9,1909, p. 216.
388 THE DATA OF GEOCHEMISTRY.

TOPAZ.

Orthorhombic. Simplest empirical formula, Al2SiO4F2 , but with 

part of the fluorine commonly replaced by hydroxyl. 1 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. 2

The synthesis of a product allied to topaz was early reported by 

A. Daubree,3 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,4 repeating the experiment, 

obtained no fluoriferous silicate. C. Friedel and E. Sarasin 5 claim to 

have prepared topaz by heating alumina, silica, water, and hydrofluosilicic acid together at 500°, but give no details nor analyses. A. 

Reich 6 subjected a mixture of silica and aluminum fluoride to a 

strong red heat, and afterwards 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, 

Tasmania, has been described by A. von Groddeck 7 as a porphyritic 

topazfels. The Brazilian topazes are found in decomposed material, 

which, according to 0. A. Derby,8 was probably a mica schist derived 

from an antecedent augite or nepheline syenite. In Colorado and 

Utah topaz occurs in lithophyses of rhyolite.9 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.10 

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 11 converted 

it into an alkaline alumo-silicate of presumably zeolitic character. 

At a white heat topaz loses fluorine and becomes transformed into 

sillimanite. 12

> S. L. Penfleld and J. C. Minor, Am. Jour. Sci., 3d ser., vol. 47,1894, p. 387.

s See F. W.Clarke and J. S. Diller, Bull. U. S. Geol. Survey No. 27,1886, and alsoClarke, Bull. No. 125,1895.

» Etudes syuthe'tiques de ge"ologie exp6rimentale, p. 57.

4 Compt. Rend., vol. 52,1861, p. 780.

» Bull. Soc. min., vol. 10,1887, p. 169.

«Monatsh. Chemie, vol. 17,1806, p. 149.

7 Zeitschr. Deutsch. geol. Gesell., vol. 36,1884, p. 642.

8 Am. Jour. Sci., 4th ser. ; vol. 11,1901, p. 25.

9 See W, Cross, idem, 3d ser., vol. 31,1886, p. 432.

10 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. 

u Zeitschr. Deutsch. geol. Gesell., vol. 40,1888, pp. 651 et seq. 

» W. Vernadsky, Bull. Soc. min., vol. 13,1890, pp. 259-260.
ROCK-FORMING MINERALS. 389 

THE 4NDALTJSITE GROUP.

Andalusite. Orthorhombic. Simplest empirical formula, Al 2Si05 ; 

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) 2Si03 / In an interesting investigation by W. Vernadsky 2 

it is shown that both andalusite and kyanite are transformed into 

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,3 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,4 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.5 

In the magmatic mixture RO.mAl2O3 .7&Si02 , if magnesia and iron are 

absent, m=l, and n is greater than 6, sillimanite is developed. K. 

Dalrner 6 has reported the alteration of a chlorite-mica phyllite into a 

mixture of andalusite and biotite.

1 A different but not very plausible interpretation of these species has been offered by K. Zulkowski, 

Monatsh. Chemie, vol. 21,1900, p. 1086.

2 Bull. Soc. min., vol. 13,1890, p. 250; Compt. Rend., vol. 110,1890, p. 1377. For earlier syntheses of these 

minerals, by Daubre'e, Deville and Caron, Fremy and Feil, Meunier, and Hautefenille and Margottet, see 

L. Bourgeois, Reproduction artificielledesrnin<§raux, pp. 119,120. Theprocesses.exceptinthelastinstance, 

involved the use of aluminum fluoride, silicon fluoride, or silicon chloride, and were therefore indirect.

s Am. Jour. Sci., 4th ser., vol. 28,1909, p. 293.

'Monatsh. Chemie, vol. 17,1896, p. 149.

»Min. pet. Mitt., vol. 18,1898, p. 72.

BNeues Jahrb., 1897, pt. 2, p. 156.
390 THE DATA OF GEOCHEMISTRY.

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.

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. 1

Andalusite alters to muscovite, 2 and sometimes also to chlorite and 

kaolin. 3 J. Lemberg,4 by heating andalusite or kyanite with alkaline 

silicates or carbonates under pressure, converted them into zeolitic 

substances. C. Doelter,5 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 

based partly upon their alterability into muscovite. On this basis 

the three species compare as follows:

Andalusite......................................... Al3 (Si04) 3(A10)3 .

Topaz............................................. Al8(Si04)8 (AlF2)3 .

Muscovite......................................... Al3 (Si04)3KH2 .

STAUBOLITE.

Orthorhombic. Composition, HFeAl5Si2 013 , 6 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,7 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. 8 P. Hautefeuille and J. Margottet, 9 in their memoir 

upon the synthesis of certain phosphates, also mention the production of a mineral resembling staurolite, but give us 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. 10 

The reported alteration into steatite is very questionable.

1 J. Kovaf, Zeitschr. Kryst. Min., vol. 34,1901, p. 704.

2 A. Gramann, Neues Jahrb., pt. 2, 1901, p. 193.

a P. E. Haefele, Zeitschr. Kryst. Min., vol. 23,1894, p. 551.

^ Zeitschr. Deutsch. geol. Gesell., vol. 40,1888, p. 651.

5 Allgem. chem. Mineralogie, p. 207.

6 Established by S. L. Penfield and J. H. Pratt, Am. Jour. Sci., 3d ser., vol. 47,1894, p. 81.

' Compt. Rend., vol. 46,1858, p. 764.

8H. Sainte-Claire Deville, idem, vol. 52,1861, p. 780.

s Idem, vol. 96,1883, p. 1052.

1° See analysis in Bull. U. S. Geol. Survey No. 220,1903, p. 54.
BOCK-FORMING MINERALS. 391 

LAWSONITE.

Orthorhombic. Composition, H4CaAl2Si2010 . 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 1 in 1895, in a glaucophane-bearing schist from Tiburon Peninsula, California. It has 

since been found by S. Franchi and A. Stella 2 in the metamorphic 

schists of the Alps; by C. Viola 3 in the saussuritized gabbros of 

southern Italy; and by A. Lacroix 4 in similar rocks and glaucophane schists from Corsica and New Caledonia. J. P. Smith 5 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 

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. Cornu,6 the compound H4CaAl2Si2O9 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.

DUMORTIERITE.

Orthorhombic. Composition, Al8HBSi3020 . 7 Molecular weight, 

634. Specific gravity, 3.3. Molecular volume, 192. Color, blue, 

bluish green, lavender, or black. Hardness, 7.

Dumortierite was orginally 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.8 

It has been observed in pegmatite, in cordierite gneiss, 9 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. It 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

iBull. Dept. Geology Univ. California, vol. 1, 1895, p. 301. See also F. L. Ransome and C. Palache, 

Zeitschr. Kryst. Min., vol. 25,1896, p. 531; and W. T. Schaller and W. F. Killebrand, Bull. U. S.-Geol. 

Survey No. 262, 1905, p. 58.

3 Cited by P. Termier, Bull. Soc. min., vol. 20,1897, p. 5. See also Termier, idem, vol. 27,1904, p. 265. 

. aZeitschr. Kryst. Min., vol. 28,1897, p. 553.

«Bull. Soc. min., vol. 20, 1897, p. 309.

5 Proc. Am. Philos. Soc., vol. 45,1907, p. 183. See also A. S. Eakle, Bull. Dept. Geology Univ. California, 

vol. 5,1907, p. 82.

B Min. pet. Mitt., vol. 25,1906, p. 249.

i As determined by W. T. Schaller, Bull. U. S. Geol. Survey No. 262,1905, pp. 91-120. See also W. E. 

Ford, Am. Jour. Sci., 4th ser., vol. 4,1902, p. 426. Ford's formula differs slightly from Schaller's.

8 See Scnaller'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, 1889, p. 211.
392 THE DATA OF GEOCHEMISTEY.

to W. Vernadsky,1 dumortierite, at a white heat, is converted into 

sillimanite. What other product is formed at the same time is not 

stated.2

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:

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.3 The following formulae seem to be best sustained by evidence : 4

(1) Al8R'5Si6B3031 .

(2) Al7R'8Si6B3031 .

(3) Al5R'14Si6B3031 .

In No. 3 the IT 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 

Al3R/ 9 (BOH) 2Si4O19 , proposed by S. L. Penfield and H. W. Foote,5 

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,

i Bull. Soc. min., vol. 13,1890, p. 256.

8 G. I. Finlay (Jour. Geology, vol. 15,1907, p. 479) reports dumortierite and corundum as original pyrogenic 

constituents of a pegmatite dike near Canon City, Colorado.

8 See C. Rammelsberg, Neues Jahrb., pt. 2,1890, p. 149. A. Kenngott, idem, pt. 2,1892, 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. P. 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. E. A. Wulfing, Min. pet. Mitt., vol. 10,1888, p. 161.

< 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. 125,1895.

5 Am. Jour. Sci., 4th ser., vol. 7,1899, p. 97; vol. 10,1900, p. 19.
BOCK-FORMING MINEEALS. 393

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 1 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,2 tourmaline yields olivine and spinel.

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 3 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 4 carried 2.76 per cent of K2O; and F. C. Robinson, 5 in another 

example, found 2.76 per cent of P205 .

J. J. Ebelmen 6 succeeded in recrystallizing beryl by fusion with 

boric oxide. P. Hautefeuille and A. Perrey 7 obtained it in crystals 

by fusing a mixture of alumina, glucina, and silica with the same 

flux. H. Traube 8 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.

1 Bull. Geol. Soc. America, vol. 10,1898, p. 21.

2 Neues Jahrb., 1897, pt. 1, p. 1.

» Am. Jour. Sci., 3d ser., vol. 28,1884, p. 25; vol. 36, 1888, p. 317.

« Jour. Am. Chem. Soc., vol. 16,1894, p. 65.

B Jour. Anal, and Appl. Chem., vol. 6,1892, p. 510.

o Annales chim. phys., 3d ser., vol. 22,1848, p. 237. . .

' Compt. Rend., vol. 106,1888, p. 1800.

8 Neues Jahrb., 1894, pt. 1, p. 275.
394 ' THE DATA OP GEOCHEMISTRY.

SERPENTINE, TALC, AND KAOLINITE.

Serpentine. Opticall}' monoclinic, but not known in true crystals. 

Composition, H4Mg3Si2 09 . 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. 1 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 

have become transformed into impure serpentine. Gabbro,2 peridotite,3 .and amphibolite 4 may undergo this change. 5 The alterative 

process, however, does not end here. Serpentine itself may undergo 

further alteration, yielding brucite, magnesite, hydromagnesite, etc. 

R. Brauns 6 has described a derivative of serpentine, which he- calls 

webskyite, H6Mg4Si3 013 .6H2 0; and F. W. Clarke 7 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.8 When serpentine is fused it yields a mixture of olivine and enstatite. 9

Talc. Monoclinic. Composition, H2Mg3Si4 012 . 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. 10 Assuming the 

change to be brought about by carbonated'water, the reactions may 

be simply written as follows:

CaMg3Si4012 +H20 + C02 = H,Mg3Si4012 + CaC03 . 

Mg4Si4012 + H20 + C02 = H2Mg3Si4012 +MgCO3 .

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.

1 See for example, A. Gages, Kept. Brit. Assoc., 1863, p. 203. Gages's product resembled deweylite.

2 See L. Finckh, Zeitschr. Deutsch. geol. Gesell., vol. 50,1898, p. 108.

3 See G. H. Williams, Am. Jour. Sci., 3d ser., vol. 34,1887, p. 137.

< See J. B. Jaquet, Rec. Geol. Survey New South Wales, vol. 5,1905, p. 18.

6 For general discussion over the 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. Bd. 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.

s See G. F. Becker, Mon. U. S. Geol. Survey, vol. 13,1888, pp. 108 et seq.; also A. Lacroix, Compt. Rend., 

vol. 124, 1897, p. 513.

8 Daubree; see ante, p. 357, under enstatite.

i" See C. H. Smyth, School of Mines Quart., vol. 17,1896, p. 333, and J. H. Pratt, North Carolina Geol. 

Survey, Economic Paper No. 3.
BOOK-FORMING MINEBALG. 395

According to F. A. Genth, talc may alter into anthophyllite. 1 

When talc is ignited, it loses water, and one-fourth of the silica is 

split off in the free state.2 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, H4Al2Si2 09 . Molecular 

weight, 259. Specific gravity, 2.6. Molecular volume, 99.6. Color, 

white, often tinted by impurities.

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 rock-making 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. ........... ...^..................... CaAl2Si6010 .5H20.

Stilbite......................................... CaA.l2Si0010 .6H20.

Laumontite.................................... CaCl2Si4012 .4H20.

Chabazite....................................... CaAl2Si4 012 .6H20.

Thomsonite.................................... CaAl2Si208 .2£H20.

Scolecite....................................... CaAl2Si3 010 .3H20.

Natrolite....................................... Na2Al2Si3010 .2H20.

Hydronephelite................................. HNa2Al3Si3Oi2 .3H20.

To these may be added ptilolite, mordenite, brewsterite, epistilbite, 

phillipsite, gismondite, laubanite, gmelinite, levynite, faujasite, 

eclingtonite, mesolite, erionite, wellsite, and perhaps other species. 

As a rule, hi the lime-bosring 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 formulae 

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 3 are other secondary minerals whose mode of occurrence is like that of the true

i Proc. Am. Philos. Soc., vol. 20,1882, p. 381.

a F. W. Clarke and E. A. Schneider, Bull. U. S. Geol. Survey No. 78,1891, p. 13.

3 On apophyllite as a rock-forming mineral, see F. Cornu, Centralbl. Min., Geol. u. Pal., 1907, p. 239.
396 THE DATA OF GEOCHEMISTRY.

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, 1 for example, produced phillipsite, levynite, and gmelinite by heating solutions of potassium silicate with 

sodium or potassium aluminate to 170°. C. Doelter 2 prepared apophyllite, okenite, chabazite, heulandite, stilbite, laumontite, thomsonite, 

natrolite, and scolecite by various processes; and J. Lemberg 3 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.4 At 

the hot springs of Plombie'res A. Daubre"e 5 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 afterwards discovered at other hot springs hi France and 

Algeria.-6

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; 7 and A. Lacroix 8 

discovered several of the species under conditions which showed a 

recent origin from cold percolating waters.

THE CARBONATES.

Cdlcite. 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.

1 Compt. Rend., vol. 54,1862, p. 324.

2 Neues Jahrb., 1890, pt. 1, p. 118.

sZeitschr. Deutsch. geol. Gesell., vol. 28, 1876, p. 519. On artificial zeolites see also F. Singer, Diss., 

Tech. Hochschule, Berlin, 1910.

« See ante, p. 351.

5 IStudes synthfitiques de gfiologie expdrimentale, p. 179.

« Idem, p. 199.

' Eept. Challenger Exped., Narrative, vol. 1, pt. 2,1885, pp. 774, 815.

8 Compt. Rend., vol. 123, 1896, p. 761. The localities described are in the Pyrenees. Plagioclase and 

scapolite were the parent minerals.
BOCK-FOKMING MINERALS. 397

Dolomite. Rhombohedral. Composition, CaMgC206 . 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, 2'9.9. Hardness, 

3.5 to 4. Color, gray to brown, sometimes white. Breunnerite and 

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 + CO2 ; 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.

1 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; O. 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 

uephcline 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 the 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.

1 A somewhat different estimate is given by H. S. Washington in Prof. Paper U. S. Geol. Survey No. 14, 

1903, p. 155. Its general purport is, however, much the same as mine.

398
IGNEOUS ROCKS. 399

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 

ver}>- 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 indefinite 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 ejnphasized.
400 THE DATA OP GEOCHEMISTRY.

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 devitrifying 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 fines, 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 less 

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 

£rom the analytical data are the ultimate criteria. Good analyses are 

easily obtained; their discussion involves no questionable hypotheses, 

and their classification is comparatively easy.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.

1 Such a classification has been proposed by H. Warth, Geol. Mag., 1906, p. 131, and elaborated in Proc. 

Roy. Soc. Edinburgh, vol. 28,1907, p. 85.
IGNEOUS ROCKS. 401

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, 

arid magmatically 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 pseudoid entity 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.

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 pheno-. 

crysts 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

'For example, H. Andesner (NeuesJahrb., Bell. Bd., vol. 30,1910, p. 467) fused ahornblendite containing 

principally hornblende, and some zoisite, quartz, rutile, and apatite. The product had the character of 

abasalt, with microscopic crystals of magnetite, augite, and plagioclase.

a Twenty-first Ann. Kept. U. S. Geol. Survey, pt. 3,1901, p. 519. Science, vol. 20, 1904, p. 550. Pub. 

Carnegie Inst. Washington, No. 31.

»See ante, Chapter IX, pp. 286-290.

101381° Bull. 491 11 26
402 THE DATA OF GEOCHEMISTBY.

Vogt. 1 That magmas and the products of their solidification must 

be studied on physicochemical lines is generally admitted, and a 

euteetic 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 that micropegmatite is a 

euteetic mixture of quartz and feldspar, and Vogt has gone still 

further in the development of probabilities. In a recent memoir 2 he 

has sought to show that a large number of eruptive rocks fall into two 

classes, which he terms "anchi-eutektische" and "anchi-monomineralische;" that is, nearly euteetic 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 wliich it is much 

more nearly allied than with the classification by radicles or oxides. 

The classification by analyses deals with the latter; the mirieralogical 

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 

euteetic 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

i F. Guthrie, Phil. Mag., 4th ser., vol. 49, 1875, p. 20. A. Lagorio, Min. pet. Mitt., vol. 8, 1887, p. 421. 

Teall, British petrography, 1888, pp. 392-402. A. C. Lane, Jour. Geol., 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. 361. Later discussions of the subject are by H. E.Johannson, Geol. Foren. F6rhandl.,vol. 27,1905, 

p. 119; S. Zemduzny and F. Loewinson-Lessing, Geol. Centralbl./vol. 8,1906, p. 393; and A. Bygdfe, Bull. 

Geol. Inst. Upsala, vol. 7, p. 1, 1906. Some difficulties in the-way of an euteetic classification have been 

clearly pointed out by W. Cross, in Quart. Jour. Geol. Soc.,*vol. 66,1910, pp. 485-488.

3 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 plagipclases, as single components.
IGNEOUS ROCKS. 403

 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 dissimilar significance. Their fallaciousness can be illustrated by considering the composition of the two fundamental olivines, 

forsterite and fayalite, Mg2Si04 and Fe2SiO4 .

Composition offorsterile and fayalite.

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

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

FeO................ ........................................

Forsterite.

42.8

. 57.2

100. 0

Fayalite.

29.5

70.5

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 obyiously 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 basylic 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, andfemic, 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 the volume upon the " Quantitative classification of igneous 

rocks," 1 by W. Cross, J. P. Iddings, L. V. Pirsson, and H. S. Washington, tho 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

1 Chicago, University of Chicago Press, 1903.
'404 THE DATA OF GEOCHEMISTRY.

superfluous, for the details are easily found elsewhere. 1 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 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 value 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, A12 03 ................................................ C.

Orthoclase, K2O.Al203 .6Si02 ............. or.

Albite, Na2O.Al203 .6Si02 ................ ab.

Anorthite, CaO.Al203 .2Si02 ............. an.,

Leucite, K2O.Al2 03 .4Si02 ............... Ic."

Nephelite, Na20.Al203 .2Si02 ............ ne.

Kaliophilite, K2O.Al203 .2Si02 ........... kp.

Sodalite, 3(Na2O.Al2 03 .2Si02).2NaCL.... so.

....... F.

Feldspars.

...................... L.

Lenads, 2 or feldspathoids.

Noselite, 2(Na2O.Al2 03.2Si02).Na,2S04 ... no.,

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

1 Among the modern classifications the following are especially important: H. Rosenbusch, Elemente 

der Gesteinslehre, 1898, p. 66. J. J. H. Teall, British petrography, 1888, pp. 70-77. F. Loewinson-Lessing, 

Compt. rend. VII. Cong. g6ol. 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 Eruptivgesteine 

des Kristianiagebietes, pt. 3,1898, p. 302. A paper by E. Sommerfeldt (Centralbl. Mta., 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. u. Pal., 1910, p. 169; and W. Cross, Quart. Jour. 

Geol. Soc., vol. 66,1910, p. 470.

2 From leucite and nephelite.
IGNEOUS BOCKS. 405

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 

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:

.P.

.0.

E.

T.

.M.

.A.

Acmite, Na2O.Fe2O3.4SiO2- ..................... .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.

Akermanite, 4Ca0.3Si02 . ....................... .am

Magnetite, FeO.Fe203 . ........................... .mt.

Chromite, FeO.Cr2 03 . ............................ cm

Hematite, Fe203 . ............................... .hm.J

Ilmenite, FeO.Ti02 . ............................ .11.

Titanite, CaO.T102 .Si02 . ....................... .tn.

Perofskite, CaO.T102 . .......................... .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
406 THE I>ATA OP GEOCHEMISTEY.

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.

Composition of Butte granite.

Norm.

Quartz..................... 19. 38

Orthoclase. ............... 25.02

Albite..................... 23.58

Anorthite................. 18.07

Diopside................... .67)

Hypersthene.............. 6. 7Sj

Magnetite................. 3. Oil

Ilmenite................... 1.22J

Pyrite..................... . 24j

Apatite................... . 31j

Etc........................ .99

66.67

7.45

4.23

55

Mode. 

Quartz...................... 22. 86

Orthoclase. ............... 18. 35]

Albite..................... 23.06 \5S. 09

Anorthite................. 16. 6sJ

Biotite............. I...... 10.92J

Hornblende................ 3.56)

Magnetite................. 1.86

Ilmenite................... .46

Pyrite..................... .241

Apatite................... . 31j

Etc........................ .85

 14.48

2.32

.55

99. 27 99. 15 

The divergence between convention and reality is evident 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 

fixed within certain arbitrary limits by the ratios between the salic 

and the femic minerals. These classes are as follows:

sal I. Persalane: Extremely salic .................... f >~r~

sal II. Dosalane: Dominantly salic. . .................. ?-

7 

r

7 5

III. Salfemane: Equally salic and femic............. f <~3~>~jT

IV. Dofemane: Dominantly femic.

V. Perfemane: Extremely femic.

fern

fern
IGNEOUS E.OCKS. 407

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, pyrite, et°- , represented by A. In Classes I 

to III the subdivision is effected through the ratio QFL : 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 : 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 

"~~ QFL 7 ,POM 7

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
408 THE DATA OP GEOCHEMISTEY.

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 53'

3. Quarfelic: Equal quartz and feldspar.............. - < > 

F 35 

Q 3 1

4. Quardofelic: Feldspar dominant................... < > 

F 5 7 

Q or L 1

5. Perfelic: Feldspar extreme....................... < 

F 7 

L 3 ' 1

6. Lendofelic: Feldspar dominant.................... < > 

F 5 7 

L "5 3

7. Lenfelic: Equal feldspar and lenad................ - < > 

F 3 5 

L 7 5

8. Dolenic: Lenad dominant......................... < > 

F 1 3 

L 7

9. Perlenic: Lenad extreme.......................... > 

F I

In Classes IV and V the femic ratio P + O : M is used to designate

the orders. They are:

P+0 7

1. Perpolic: Silicate extreme...................... > 

. M 1 

P+0 7 5

2. Dopolic: Silicate dominant..................... < > -

M 1 3 

P+0 5 3

3. Polmitic: Silicate and nonsilicate equal.......... </^> 

M 35 

P+0 3 ]

4. Domitic: Nonsilicate dominant................. < > 

M 57 

P+0 1

5. Permitic: Nonsilicate extreme.................. < 

M 7

Iii 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 rnineralogical, and expressed in terms of the standard or normative minerals.
IGNEOUS ROCKS. 409

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 : salic CaO is the determining factor. In Classes IV 

and V the molecular ratio of femic CaO + (MgFe) 0 : 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 Na2 0 

under the general symbol of R2 0, the rangs under the orders of 

Classes I to III develop thus:

1. Peralkalic....................................

2. Domalkalic...................................

3. Alkalicalcic...................................

4. Docalcic.....................................

5. Percalcic......................................

CaO

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 Zime the word mirlic is suggested. Uniting MgO, FeO, and CaO under the symbol RO we now have in the

distinctively femic classes these rangs:

HO 7 

1. Permirlic...................................

R2 0 1 

BO 7 5

2. Domirlic...................................... < > 

R2 0 1 3 

BO 5 3

3. Alkalimirlic.................................... < > 

R?0 3 5 

BO 3 1

4. Domalkalic.................................... < > 

B20 5 7 

BO 1

5. Peralkalic..................................... < 

B20 7

The femic rangs are again subjected to a fivefold subdivision into 

sections, depending upon the ratio (MgFe) O : CaO; and they are also 

divided into subrangs which indicate the ratio between magnesia 

and ferrous oxide. So also, in Classes I to III there are subrangs
410 THE DATA OP GEOCHEMISTKY.

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 + 0: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 : R2 0; R2 0 : CaO; (MgFe) 0 : CaO; and MgO : 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, 

e'xpressive 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 classification like that now in vogue would have to be

1 For the detailed development of this notation, which can be extended to grads and subgrads, see H. S. 

Washington, Prof. Paper U.S. Geol. Survey No. 28,1904, pp. 13-15. On the calculation of norms, see G. I. 

Flnlay, Jour. Geology, vol. 18,1910, p. 58. *
IGNEOUS BOCKS. 411

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 two 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 1900, 

are of the highest value and go far to justify the system.

COMPOSITION OP BOCKS.

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. 419. 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 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.

1 The need of rock names for field use is fully recognized by the authors of the quantitative system.

2 Prof. Papers U. S. Geol. Survey Nos. 14 and 28. For analyses made in the laboratories of the Survey, 

see also Bull. No. 419. For an extended application of the quantitative classification, see Washington's 

Roman comagmatic region, Pub. No. 51 of the Carnegie Institution, 1906. For reviews and criticisms of 

the new system, see A. Michel Levy, Bull. Carte geol. France, No. 92, 1903; A. Hjarker], Geol. Mag. 

1903, p. 173; J. W. Evans, Science Progress, vol. 1, 1906, p. 259; E. B. Mathews, Am. Geologist, vol. 31, 

1903, p. 399; and L. Milch, Centralbl. Min., Geol. u. Pal., 1903, p. 677.
412 THE DATA OF GEOCHEMISTEY.

THE RHYOUTE-GrRANITE 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 

quartz, 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 familar group of rhyolites and granites. With this group it is convenient to begin.

In the broadest sense, granite may be defined as a holocrystalline, 

plutonic 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, arid 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 Rhyolite 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.

Analyses of rhyolites.

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. Magdeburgose.

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 Clifl, 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.____________________________________________________

1 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. Bastin, Jour. Geology, vol. 18,1910, p. 297; and A. Barker, 

Natural history of igneous rocks, p. 293.
IGNEOUS BOCKS. 413

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 ard feldspar. Symbol, 

1.3.2.3. Tehamose.

F. From " Elephant's Back," Yellowstone National Park. Analysis by Whitfleld. Reported by J. P. 

Iddings to contain quartz and sanidine, with a little augite and magnetite, in a glassy groundmass. Symbol, 

1.3.2.3. Tehamose.

G. From Haystack Mountain, Aroostook County, Maine. Analysis by Hillebrand. Described by H. E. 

Gregory. Contains quartz, albite, and orthoclase, 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, hypersthene, and magnetite, in a glassy groundmass crowded with microlites of feldspar and 

augite. Symbol, 1.4.2.4. Lassenose.

SiO........ ...........

AljOg.................

FeA ..............

FeO. ................

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

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

Na.0..... ............

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

HaO-. ..............

HaO+. ..............

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

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

P O

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

BaO. .....:...........

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

Li20......... .........

SO...................

FeS2 . ........ .........

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

A

73.23

12,73

.99

.16

.22

.61

1.91

5.17

.53

4.51

.09

.02

trace

.02

trace

100. 19

B

74.24

14.50

1.27

.67

.25

.11

3.00

3.66

2.04

.20

.07

.06

.18

trace

.03

100. 28

C

75.52

14.11

1.74

.08

.10

.78

3.92

3.63

1 .39

none

.11

100. 38

D

75.19

13.77

.61

1.37

.09

.68

3.83

3.33

I ft* > . 65

none

.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

trace

.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

G

75.98

12.34

.85

.93

.15

.13

4.02

4.44

.24

.64

.17

.03

.03

trace?

.07

trace?

none

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

trace

99.63

Norms.

Q... ..................

an ...................

C... ..................

hy........... ........

mt........... .........

hm............... .....

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

F

36.1

25.0

27.8

5.6

.4

3.3

.7

G

35.1

26.1

33.5

.6

.8

1.4

1.2

H

07 A.

16.7

43.0

8.1

1.2

1.4

.8
414 THE DATA OF GEOCHEMISTKY.

The following analyses 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. Eaklns. 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, Plumas 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.

SiO............ ........................

AI n

FeA... ...............................

FeO...... ...... ......................

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

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

NagO....... ...........................

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

H20.................... .............

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

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

Zr02 .................:.................

C02 . .................................

P O

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

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

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

Li20....................................

Cr203 .. ...............................

VA-, ................................

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

Cu.................... ...............

FeS2 .. .................................

A

79.75

10. 47

.64

.92

.13

.15

1.36

6.01

.08

.60

.15

.05

.06

i"T*O f*&

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

.03

.39

100. 06

C

73.50

14.87

.95

.42

.29

2.14

3.46

3.56

} .90

none

.03

trace

100. 12

D

71.56

14.27

1 .89

.42

1.18

3.00

4.37

.36

.79

. .38

.13

.28

.01

.06

2.29

99.99

E

73.25

13.25

1.74

.28

2.23

2.69

3.79

.07

1.03

1.05

.58

99. 96

Norms.

Q... .................................

ab.......... ..........................

an.......... ..........................

C........................ ..............

di....................... ..............

hy...................... ..............

mt. ..................................

a.............................. ........

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

CM O

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. 415

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. Magdeburgose.

B. Biotite granite, Sentinel Point, Pikes Peak, Colorado. Described by Mathows. Contains microcline, microcline-perthite, quartz, biotite, a little oligoclase, and accessory fluorite, apatite, zircon, sphene, 

allanite, and me.gnetite. 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. Omeose.

D. Biotite granite, Mount Ascutney, Vermont. 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 H. W. Turner. Contains orthoclase, 

quartz, plagioclase, a little microcline, brown mica, and iron ore. Symbol, 1.4.2.3. Toscanose.

SiOo...... ............ AI n

Fe203 -----------------

FeO...................

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

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

Na2 0........... ......

KjO...................

HaO..................

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

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

ZrQ2 ... ...............

cq.............. ......

P O

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

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

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

Li,Q..... .............

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

01.....................

FeSa ... ...... .........

A

74.40

14. 43

.89

.22

.07

.58

1.76

6.56

.15

.92

.12

.22

trace

trace

none

trace

.04

100. 36

B

77.03

12.00

.76

.86

.04

.80

3.21

4.92

.14

.30

.13

trace

trace

trace

none

trace

.36

100. 55

C

73.90

13.65

.28

.42

]4

.23

2.53

7.99

.16

.33

.07

.05

trace

trace

none

trace

99.75

D

71.90

14.12

1.20

.86

.33

113

4.52

4.81

.18

.42

.35

.04

91

.11

.05

.04

.06

09

100. 35

E

72.42

13.04

.68

2.49

.58

.66

3.44

4.97

} 1.21

.40

.20

.09

.15

trace?

100. 33

F

75.92

12.96

.33

1.40

trace

.15

4.60

4.15

.16

.32

.05

03

.04

trace

none

trace

.12

100. 23

G

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

none

100. 33

Norms.

Q... ..................

ab....... ..............

C.....................

di...... ..............

hy.. .................

il........... ..........

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

1.1

.3

1 Q

.6

E

90 4

30.0

28.8

3.2

.8

5.0

q

.8

F

32.0

24.5

38.8

.8

.6

2.2

.2

G

33.1

36.1

22.0

5.8

1.2

1.1

.6

n

36.3

30.6

25.2

5.0

1.0

.7

1 A. Gautier (Compt. Rend., vol. 132,1901, p. 932) found traces of'nitrpgen, argon, arsenic, and iodine in 

, granite.
416 THE DATA OF GEOCHEMISTRY.

All of 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 gra; fees 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 micas, 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.

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 rhyolites, 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. S. 

Daly. Contains orthoclase, plagioclase, quartz, hornblende, magnetite, apatite, and zircon, with very 

little biotite, titanite, diopside, and allanite. Magmatic symbol, 1.5.1.3. Phlegrose.

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, segirite, 

augite, quartz, and apatite, with an occasional zircon and traces of biotite. Symbol, 1.5.1.4. Nordmarkose.

C. Biotite trachyte, Dike Mountain, Yellows tone 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. Nordmarkose.

D. Soda syenite porphyry, Moccasin Creek, Tuolumne County, California. Analysis by Stokes. 

Described by H. W. Turner. Consists mainly of albite, with possibly aegirite. Symbol, 1.5.1.5. Tuolumnose.

E. Soda syenite, Douglas Island, Alaska. Analysis by Hillebrand. Described by G. F. Becker. Contains 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 contain orthoclase, plagioclase, biotite, and chlorite. Symbol, 1.5.2.3. Pulaskose.

G. Augite syenite porphyry, Copper Creek basin, Yellowstone Nat " nal Park. Analysis by Hillebrand. 

Contains, according to Hague and Jaggar, augite. biotite, orthoclase, a little hornblende, and quartz. Symbol, 1.5.2.4. Laurvikoss.

1 Or undistributed alumina.
IGNEOUS ROCKS. 417

H. Augite syenite, Turnback Creek, Tuolumne County, California. Analysis by Stokes. Reported by 

Turner to contain orthoclase and augite, with less plagioclase and quartz. Symbol, II.5.1.2. Highwoodose.

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. Monzonose.

J. Syenite, La Plata Mountains, Colorado. Analysis by Stokes. Reported by W. Cross to contain much 

alkali feldspar, some oligoclase, augite, biotite, and hornblende, with a little titanite, magnetite, and apatite. 

Symbol, II.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. Akerose.

8i09 .. ....................... AI n

Fe2 03 .......................

FpO

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

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

Mi O

K2A u.......... ' ..- .....--. - 

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

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

Tif)

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

oouo......... .................

£.U8 ...... .......... .........

01... .........................

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

MnO.. ....'...................

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

SrO.......................... VA- - -.-..--..-.-.- -

Li20. ........................

FeS2 ..... ....................

Si03 ...........................

AljOg........ ..................

FOyO,... .......................

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

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

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

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

K&....... ...................

H80.........................

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

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

ZrOa ...........................

CO,. .........................

P O

soa ...........................

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

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

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

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

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

LijjO...........................

A

65.43

16.11

1.15

2.85

.40

1.49

5.00

5.97

.19

.39

.50

.11

.13

.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

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

100. 10

C

63.24

17.98

2.67

.85

.63

.93

6.27

5.47

.37

.80

.38

trace

.22

.04

.25

.03

.01

100. 14

H

61.28

14.71

1.21

2.85

1.69

5.61

2.99

7.70

.28

.43

.41

.16

.08

.72

.04

100. 16

D

67.53

18.57

1.13

.08

.24

.55

11.50

.10

.15

.31

.07

.11

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

trace

100. 15

E

63.01

18.47

.06

.32

.06

2.66

10.01

.39

.05

97

.13

o m

.06

.06

o?

.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

90

.14 .11

i"rfir*A

100. 14

F

57.73

18.93

1 Q7

1.92

Q1

2.78

5.52

6.11

99

O qq

.33

trace

oc

.25

.06

.16

OQ

.01

i*i»nf»<a

02

100. 20

K

58.28

17.89

q on

1 73

1.51

3.69

5.89

5.34

.17

Qft

.64

.26

.06

.36

.05

100. 05

101381° Bull. 491 11 27
418 THE DATA OF GEOCHEMISTRY.

Analyses of trachyte-syenite rocks Continued. 

Norms.

Q............................

di.............................

wo.............................

hy... ........... ..............

ol..... ........... .............

il............................

pr... ...... ...................

Q............................

ab... .........................

di.............. ...............

wo................... ..........

hy.............................

ol..... ........................

hm ...........................

il..............................

A

8.8

35.6

42.4

3.6

3.4

2.4

2.1

q

B

5.3

33.9

51.9

2.8

1.4

1.6

1.0

Q

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

16.0

1.9

1.6'

.8

D

0.6

95.4

1.4

1.3

.5

o

.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

Q

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 I..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 BOCKS. 419

Analyses offemic syenites.

A. Soda minette, Brathagen, Laugendal, Norway. Analysis by V. Schmelck. Described by W. C. 

Brogger (Die Eruptivgesteine des Kristianiagebietes, vol. 3, 1898, p. 130). Contains, in approximate 

percentages, 54 soda feldspar, 29 lepidomelane, 13 aegirine-augite, 2J apatite, and 1 sphene. Magmatic 

symbol, II.5.2.4. Akerose.

B. Soda minette, Hao, Langesund Fjord, Norway. Analysis by Schmelck, description by Brogger 

(Die Eruptivgesteine des Kristianiagebietes, vol. 3, 1898. p. 139). Contains about 51J per cent soda feldspar, 26.5 lepidomelane, 16§ diopside, 2J each of apatite and sphene. Symbol, II.6.1.4. 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 olivine. Symbol, 

III.5.2.2. Prowersose..

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, ana 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, Avith biotite, iron ore, andesine, apatite, olivine, and 

a trace of kaolin. Symbol, III.6.2.3. Shonkinose.

SiO2 . ......:.........................

A1203 - ....-.........-........----.-.-

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

Feb.3 ............................... Mgo.................... :............

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

Na20................................

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

H20............................... E/H.......... ....................

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

C02 ..................................

P O

s6,r.v:::::"::::::::::::::::::::::: 01.'.. ...............................

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

V203 ... .............................

Cr203 ...............................

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

4.09

5.70

3.54

6.10

5.43

4.45

| 1.10

1.95

1.15

.30

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

9.87

3.46

5.01

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

12.29

2.88

5.77

9.19

9.65

2.22

4.96

.26

.56

1.44

.98

.22

.08

.43

.08

trace

99.99

Norms.

TIP

di...... :............................

ol...................................

il....................................

ap ..................................

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

' 29.5

5.3

8.6

6.8

26.5

11.7

4.2

2.6

2.2
420 THE DATA OP GEOCHEMISTEY.

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 a's 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, nephehte, 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 so little 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. Magmatic symbol, 1.6.1.4. Miaskose.

B. Phonolite, Black Hills, South Dakota. Analysis by W. F. Hillebrand. Described by W. Cross. 

Contains orthoclase, nephelite, segirite, 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, segirite, etc. Symbol, 1.6.1.4. Miaskose.

D. Phonolite, Pleasant Valley, Colfax County, New Mexico. Analysis by Hillebrand. Reported 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. Judithose. . 

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, Basanite, 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. Basanite, Mount Inge, Uvalde County, Texas. Analysis by Hillebrand; description by Cross. Contains orthoclase, nephelite, hornblende, augite, agirine-augite, olivine, magnetite, apatite, and a trace of 

pyrite. Symbol, II.7.1.4. Lujavrose.
IGNEOUS BOCKS. 421

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

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

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

FeO.................

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

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

Na20.................

K26.................

H20..................

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

TiOa ..................

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

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

p o

S03 ..................

S. ...................

01.. .................

F

V203 .................

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

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

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

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

Li20..................

A

54.22

20.20

2.35

1.02

.29

.70

9.44

4.85

.42

5.57

.38

.11

.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

1.38

10.53

5.74

.12

.86

.26

.09

.06

.10

.03

.12

trace

.08

.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

.01

.23

none

.15

none

.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

5.89

8.00

3.80

.18

1.59

1.74

.05

.49

.09

.29

.06

.19

.02

.10

.10

trace

99.93

Norms.

or.. .................

TIP

ac ...................

di.. ..................

ol....................

il.....................

ap.. .................

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

L2

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

3.9

3.7

1.7

H

22.2

14.1

3.1

29.0

18.6

.8

4.9

3.4

1.1
422 THE DATA OF GEOCHEMISTRY.

The following table contains analyses of deep-seated rocks of the 

nephelite series:

Analyses of deep-seated nephelite rocks.

A. Elaeolite syenite, or litcMeldite, Litchfield, Maine. Analysis by L. G. Eakins. Described by W. S. 

Bayley. Contains elseolite, two feldspars, and lepidomelane, with accessory sodalite, cancrinite, and 

zircon. Magmatic symbol, 1.5.1.4. Nordmarkose.

B. Elseolite syenite, Beemersville, New Jersey. Analysis by Eakins. Described by J. P. Iddings. 

Contains nephelite, orthoclase, segirite, 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 F. L. Ransome. 

Contains alkali feldspars, altered nephelite, amphibole, biotite, cancrinite, plagioclase, inuscovite, ajgirineaugite, apatite, fluorite, and traces' of magnetite, with secondary analcite, sericite, and natrolite (?). Symbol, 

1.6.2.4. Viezzenose.

D. Eteolite 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, H.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 aegirite, 

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. g6ol. 

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, H.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.

SiOa ........... .......

A12O8 .. ...............

FeAFeO

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

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

Na20....... ..........

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

EJ)-. ..............

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

TSO

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

C02 ............ .......

P O

s&°!:::::::::::::::::

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

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

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

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

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

VA.................

Li203 ............ ......

A

60.39

22.57

.42

2.26

.13

.32

8.44

4.77

1 W

\ >5/

.08

99.95

B

53.56

24.43

2.19

1.22

.31

1.24

6.48

9.50

1 Q3

> . <70

.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

5.34

.15

.50

.81

.12

.03

.08

trace

trace

99.98

E

54.34

19.21

3.19

2.11

1.28

4.53

6.38

5.14

.14

1.17

1.09

.07

.27

.07

.28

.08

.24

.16

.02

trace

99.77

F

45.28

27.37

3.53

.49

.33

1.22

17.29

3.51

1 .40

.19

99.61

G

43.02

24.63

3.59

2.17

1.96

5.47

14.81

2.99

.63

' .70

99.97

H

44.65

13.87

6.06

2.94

5.15

9.57

5.67

4.49

Qfi

2.10

.95

.11

1.50

.61

trace

.17

.76

.37

trace

99.93
IGNEOUS BOCKS. 423

Analyses of deep-seated nephelite rocks Continued. 

Norms.

ab ...................

Ic......... ...........

kr>

so.....................

no ...................

c.....................

nr»

di....................

ol....................

am.. ................

a.......... ...........

QT~»

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

q

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

1.9

2.3

1.5

E

30.6

34.1

9.2

6.0

3.9

6.9

1.3

4.6

2.0

..7

F

16.1

65.0

10.2

3.4

3.4

.8

G

9.6

59.4

3.2

10.2

1.0

5.8

8

0

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 nephelino syenites is given by W. C. Brogger in his work Die 

Eruptivgesteino 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., 4th ser., 

vol. 17,1904, p. 269. It contains 72.2 per cent of nephelite, 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, and R. A. Daly, Bull. Geol. Soc. America, vol. 21,1910, p 87.
424 THE DATA OP GEOCHEMISTRY.

LEUCITE BOCKS.

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 of leucite rocks.

A. Pseudoleucite-sodalite tinguaite, Bearpaw Mountains, Montana. Analysis by H. N. Stokes. 

Described by W. H. Weed and L. V. Pirsson. Contains orthoclase, nephelite, sodalite, noselite, segirite, 

diopside, and fluorite. Magmatic symbol, II.7.1.3. Janeirose. Although leucite is not reported here, it 

appears abundantly in the norm. 0

B. Arkite, or leucite syenite, Magnet Cove, Arkansas. Described and analyzed by H. S. Washington, 

Jour. Geology, vol. 9, 1901, p. 616. Contains, in percentages, orthoclase, 3.9; leucite, 36.9; nephelite, 25.5; 

segirite, 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. F. Hillebrand. Described 

by W. Cross. Contains phlogopite, leucite, diopside, and apatite. Symbol, III.6.1.1. Wyomingose.

D. Leucitite, Bearpaw Mountains, Montana. Analysis by Stokes. Described by Weed and Pirsson 

as an oliv-ine-free leucite basalt. Contains leucite, augite, iron oxides, rarely biotite, and a little glassy 

base. Symbol, IU.8.1.2. Chotose.

E. Leucitite, Alban Hills, Italy. Described and analyzed by Washington, Am. Jour. Sci., 4th ser., 

vol. 9, p. 53,1900. 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 perofskite 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.

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

ALO.. ...............

. _ & _0 Fe203 ................

FeO..................

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

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

Na20................

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

HaO.................

H/H................

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

TaQ^.. ...............

C02 ..................

p n

s&°?::.:::::::::::::::

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

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

Cr203 .................

Di203 .. ....... ........

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

MO.................

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

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

Li20.................

A

51.93

20.29

3.59

1.20

.22

1.65

8.49

9.81

MO

.99

.20

.25

.06

.67

.70

.27

.09

.07

100. 58

B

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

7.09

5.99

1.37

9.81

.93

1.72

2.27

1.89

.74

.03

.50

.10

.03

.05

1.23

.24

100. 62

D

46.51

11.86

7.59

4.39

4.73

7.41

2.39

8.71

. 1.10

2.45

.83

.80

.05

.04

.22

.04

.50

.16

99.78

E

45.99

17.12

4.17

5.38

5.30

10.47

2.18

8.97

.45

.37

.25

100. 65

F

42.65

9.14

5.13

1.07

10.89

12.36

.90

7 QQ

2.04

2.18

1.64

1.52

.58

.03

.47

.07

.11

.12

.89

.33

trace

100. 11

G

46.06

10.01

3.17

5.61

14.74

10.55

1 31

5.14

| 1.44

.73

.21

.05

flQ

.32

.20

99.57
IGNEOUS ROCKS. 425

Analyses of leudte rocks Continued.

Norms.

or. ...................

an..... ...............

Ic

ne. .................

so....................

no....................

ac....................

di...................

wo. ..................

ol.....................

il....................

ap . . ... .

ft.....................

A

33.9

18.7

9.8

5.3

10.2

5.7

.5

.7

B

1.1

37.9

29.8

9.6

12.0

4.9

1.8

2.8

C

44.5

10.5

1.7

7.4

13.9

7.9

.8

4 i

4.5

D

7.8

34.0

10.8

6.9

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 plutonic 

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 microclme together, 

Fouque" and LeVy 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 hauynite, are also 

noteworthy constituents of certain rare rocks, which we need not 

consider in detail. Sodalite syenite, hauynophyre, 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.

1 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 of the Carnegie Institution, Washington, 1906.

2 See H. Backstrom, Geol. Foren. Forhandl., vol. 18,1896, p. 155. 

' Synthese des mine'raux et des roches, p. 77.

« For analyses see Washington's Tables, Prof. Paper U. S. Geol. Survey No. 14,1903, pp. 201, 215, 303, 

305, 349, 351.
426 THE DATA OF GEOCHEMISTKY.

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 following analyses represent the last-named rock 

family:

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 ser., vol. 45,1893, p. 286. Contains, in percentages, orthoclase, 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. 1S2. 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. Ileronite, 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; ffigirite, 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 W. H. 

Weed and L. V. Pirsson, Contains olivine, augite, biotite, analcite, and apatite, with traces of serpentine 

and chiorite. 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. 

Monchiquose.

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. Monchiquose.

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. Monchiquose.

H. Analcite basalt, near Cripple Creek, Colorado. Analysis by Hillebrand. Described by W. Cross. 

Contains augite, olivine, analcite, alkali feldspars, biotite, and apatite. Symbol, III.6.2.4. Monchiquose.

1 Proc. California Acad. Sci., 2d ser., vol. 3,1891, p. 51.

2 See citations under analcite in Chapter X, ante, pp. 351,352. 

a Sixteenth Ann. Kept. U. S. Geol. Survey, pt. 2,1896, p. 32. 

«Jour. Geology, vol. 4,1896, p. 679. 

5 Min. pet. Mitt., vol. 11,1890, p. 454.
IGNEOUS ROCKS. 427

SiO...................

AlaOa . ..........

Fe2 03 ...... ...........

FeO

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

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

NaoO.................

KoO................. "EQQ-. ..............

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

TiOo.................

ZrO;.................

C02 ............ .......

p ^.u..... r> ..............

01. ......... .1.......

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

Cr203 . ...............

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

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

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

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

Li20..................

A

56.45

20.08

1.31

4.39

.63

2.14

5.61

7.13

.26

1.51

.29

.13

.43

Of)

100. 45

B

56.75

20.69

3.52

.59

.11

.37

11.45

2.90

.04

3.18

.30

.28

trace

100. 18

c

52.73

20.05

3.43

.99

.17

,3.35

7.94

4.77

.69

4.85

.93

.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

.07

trace

.32

.15

99.90

E

46.48

16.16

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

100. 01

G

47.82

13.56

4.73

4.54

7 49

8 Ql

A Q7

3.23

} 3.37

.67

1.10

tniCG

.04

trace

.16'

.21

100. 20

H

45.59

19 QR

4 Q7

4 70

8.36

11.09

4.53

1. 04

.51

3.40

1.32

.03

Ql

.05

14

.is

.12

99.87

Norms.

ab ...................

1-1 P

so ...................

n f\

di..... ...............

ol....................

il.....................

A

41.7

28.3

10.6

3.4

5.9

6.1

1.9

.6

B

17.2

46.6

23.6

6.0

.5

.5

2.0

C

23.4

30.9

5.0

19.6

.1.0

4.4

3.2

1.1

D

18.9

14.7

3.6

11.1

24.4

15.2

5.8

1.4

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.
428 THE DATA OF GEOCHEMISTEY. 

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 of these rocks carry orthoclase or 

anorthoclase with plagioclase in approximately equal amounts, with 

or without quartz, and with smaller amounts of the ferromagnesian 

silicates. The next table 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. Toscanose.

B. Quartz monzonite, Telluride quadrangle, Colorado. Analysis by H. N. Stokes. Described by W. 

Cross. Contains orthoclase and plagioclase in nearly equal amounts, quartz, augite, hornblende, biotite, 

magnetite, and apatite. Symbol, 1.4.2.3. Toscanose.

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. Toscanose.

D. Monzonite, Tintic district, Utah. Analysis by Stokes. Described by G. W. Tower and G. O. Smith."' 

Contains orthoclase, plagioclase, quartz, hornblende, biotite, magnetite, apatite, zircon, and titanite, with a; 

little chlorite and epidote. Symbol, II.4.3.3. Harzose.

E. Monzonite (yogoite), Yogo Peak, Little Belt Mountains^ Montana. Analysis by Hillebrand. De-} 

scribed by W. H. Weed and L. V. Pirsson. Contains orthoclase, oligoclase, pyroxene, hornblende, biotite,] 

apatite, titanite, iron ore, and a little kaolin. Symbol, II.5.2.3. Momonose.

F. Augite latite, Dardanelle 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 Ransome. 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, quartz, titanite, magnetite, and! 

apatite. Symbol, II.5.3.4. Andose.
IGNEOUS BOCKS. 429

SiO........ ...........

AI n

Feo08 .................

FeO...................

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

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

NaoO. ................ K3)............ .......

H20..................

HjO+. ...............

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

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

GO....................

P O

sfr.v.v.v.v.::::::::

so...... .............

01..................... VA 

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

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

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

Li20..................

FeS2 ..................

C.....................

A

68.42

15.01

.97

1.93

1.21

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

.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

1.05.

.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

.87

.78

.42

.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

.80

.59

10

.32

.13

trace

"

100. 19

'F

59.43

16.68

9 "S4

3.48

1.84

4.09

3.72

5.04

.27

.72

1.38

.08

.58

.05

trace

.14

trace

none

100. 04

G

56.19

16.76

q AC

4.18

3.79

6.53

2.53

4.46

.34

.66

.69

.55

10

1Q

trace

trace

100. 02

H

C7 Aft

18.48

3 74.

9 10

1.71

6.84

4.52

3.71

.08

.28

.86

.36

.03

.09

.15

.08

trace

100. 45

Norms.

Q............. ........

or.....................

c.....................

di....................

hy...................

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

12.4

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

i.9. i

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
430 THE DATA OP GEOCHEMISTKY.

THE ANDESITE-DIORITE 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 inclu. 

sions, and glass. Magmatic symbol, 1.4.2.4. Lassenose.

B. Quartz diorite, near Enterprise, Butte County, California. Analysis by W. F. Hillebrand. Reported 

by H. W. Turner to contain plagioclase, potash feldspar, quartz, hornblende, mica, and accessories. 

Symbol, 1.4.2.4. Lassenose.

C. Dacite, Sepulcher Mountain, Yellowstone National Park. Analysis by J. E. Whitfleld. Described 

byj. P. Iddings. Contains plagioclase, quartz, biotite, and hornblende. Symbol, 1.4.3.4. Yellowstonose.

D. Quartz diorite, Pigeon Point, Minnesota. Analysis by Hillebrand. Described by W. S. Bayley. 

Contains feldspar, quartz, hornblende, chlorite, magnetite, apatite, and rutile. Symbol, II.4.2.3. 

Adamellose.

E. Quartz-mica diorite, near Milton, Sierra County, California. Analysis by Hillebrand. Described 

by Turner. Containes plagioclase, quartz, hornblende, brown mica, iron ore, and apatite. Harzcse.

F. Quartz-mica diorite, Electric Peak, Yellowstone National Park. Analysis by Whitfleld. 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 epidote. Symbol, II.4.4.3. Bandose.

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

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

FeA........... ......

FeO...................

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

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

Na20. - - --- --------

KoO...................

H20..................

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

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

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

C02 ...................

p d

S03 . ................. ci... ............... ....

V2<v--. ..... 

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

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

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

Li20.......... ........

C............. ........

A

68.10

15.50

3.20

none

.10

3.02

4.20

3.13

2.72

.15

.03

trace

.06

trace

none

100. 21

B

70.36

15.47

.98

1.17

.87

3.18

4.91

1.71

. .06

1.00

.20

.11

trace

.06

trace

trace

100. 08

C

65.66

15.61

2.10

2.07

2.46

3.64

3.65

2.03

} 1. 07

1.37

trace

.13

.12

none

.36

100. 27

D

57.98

13.58

3.11

8.68

2.87

2.01

3.56

3.44

1 2.47

1.75

.29

.13

.04

trace

99.91

E

57.26

6.51

3.27

5.19

3.41

6.69

2.65

2.93

.20

.95

.53

.30

.18

.10

.06

trace

100. 23

F

65.11

16.21

1.06

3.19

2.57

3.97

4.00

2.51

} .94

.71

.02

trace

none

.04

100. 33

G

58.09

17.46

1.12

5.08

4.06

6.24

2.94

2.02

.29

1.45

.95

.21

.17

.05

.02

none

.07

.04

none

.11

100. 37

H

58.57

16.10

2.89

6.12

2.33

7.39

2.11

1.01

.21

1.27

1.41

09

.37

.02

.18

trace

trace

100. 07
IGNEOUS ROCKS.

Analyses ofdacitcs and quartz dioritcs Continued. 

Norms.

431

Q.....................

or.....................

c.....................

di....................

hy...................

mt........... .........

il..... ................

tn......... ............

A

25.4

18.3

35.6

14.2

.7

3.' 2

.4

D

27.1

10.0

41.4

15.3

3.1

1.6

.5

C

25.0

12.2

30.9

18.1

.7

6.2

2.8

2.6

D

11.1

20.0

29.9

10.0

.5

17.7

8.0

3.4

E

10.3

17.2

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

G

11.2

12.2

24.6

28.4

2.1

16.0

1.6

1.8

H

21.3

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.
432 THE DATA OF GEOCHEMISTRY.

Analyses ofandesites.

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 tridymiteMagmatic symbol, 1.5.2.3. 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.5.2.4. Akerose.

C. Augite andesite, Dike Mountain, Yellowstone National Park. Analysis by Hillebrand. According 

to Arnold Hague and T. A. Jaggar it contains plagioclase, augite, apatite, magnetite, and serpentinized 

olivine. Symbol, II.5.3.3. Shoshonose.

D. Augite-bronzite andesite, 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 magnetite. Symbol,

II.5.4.3. Hessose.

F. Augite andesite, near Electric Peak, Yellowstone National Park. Analysis by Hillebrand. 

Described by J. P. Iddings. Contains plagioclase, malacolite, actinolite, and magnetite. Symbol,

III.5.3.3. Kentallenose.

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

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

FeA.. ......................

FeO..........................

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

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

Na20........................

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

H20.........................

HP0+.............. ..........

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

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

P O

v2o...... ......................

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

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

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

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

Li20.........................

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

.48

.04

.21

.01

.20 .10'

trace

.05

99.94

D

56.63

16.85

3.62

3.44

4.23

7.53

3.08

2.24

.80

.51

.67

.16

.04

.23

.09

! trace

.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

.11

.04

100. 06

F

50.59

11.49

1.83

7.64

11.27

8.79

2.27

2.33

.21

1.76

.80

.48

.04

.17

.06

.10

.03

99.86

Norms.

Q............................

or............................

ab...... ......................

di...........................

by........ ...... ..............

of.................. ...........

mt...... .....................

hm. ...........................

a............................

aD....

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

1.0

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

1Q 4

13.9

22.4

8.7

14.1

2.6

1.5

1.0
IGNEOUS BOCKS. 433

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 

called "camptonite." Tonalite and kersantite are other varieties. 

The following analyses represent the diorite group:

Analyses of diorites.

A. Diorite, Mount Ascutney, Vermont. Analysis by W. F. Hillebrand. Described by R. A. Daly. 

Contains hornblende, augite, biotite, plagioclase, titaniferous 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, 11.5.2.4 A kerose.

C. Diorite, Crazy Mountains, Montana. Analysis by Hillebrand. According to J. E. Wolfl 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. Andose.

E. Diorite, South Honcut Creek, Butte County, California. Analysis by Hillebrand. Reported by 

H. W. Turner to contain feldspar, hornblende, and a little chlorite. Symbol, II.5.3.5. Bcerbachose.

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. Camptonose.

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.

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

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

Fe2 03 ----- ---- -- 

FeO...................

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

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

Na20. ................

K2 0. - - - -- -- --

H30..................

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

TiO.......... .........

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

C02 ...................

P205 ..................

01.....................

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

vao..................

Cra03 ... ...............

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

(NiCo)O...............

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

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

Li20..................

FeS,. ........ .........

A

57.97

17. ?,8

2.23

3.75

2.20

4.33

4.31

4.12

.18

.57

} 1.54

.05

.64

.04

.15

.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

99.96

C

57.97

15.65

.73

2.80

4.96

10.93

3.03

3.16

.22

.38

.60

.15

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

.11

09

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

100. 12

F

47.25

15.14

5.05

4.95

6.87

9.98

2.39

2.60

.40

2.12

1.22

1.87

.25

.05

.17

.02

.08

.05

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

.24

1.62

2.03

.26

.03

.01

.22

.03

trace?

trace?

trace

99.98

101381° Bull. 491 11- -28
434 THE DATA OF GEOCHEMISTRY.

Analyses ofdiorites Continued. 

Norms.

Q............ .........

ab.................

an.................

di...... ..............

hy...................

cl...... ..............

mt........... . ........

il.....................

A

4 Q

24.5

37.2

15.0

2.5

6.9

3.2

2.9

1.3

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

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, ard a little biotite. 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 augito, plagioclase, clivine, and iron ores. 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. 

Camptonose.

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.

See J. S. Diller, Bull. U. S. Geol. Survey No. 79,1891.
IGNEOUS ROCKS. 435

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

Al O

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

FeO

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

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

NaoO. .......... .......

K26. .................

H2 0.................

HaO+................

Ti03 ... ................

P r-u........ O ............

oU3 .- ................. ci....................

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

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

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

&0. .................

Li2 0. ..................

FeS,... ................

A

49.69

18.06

2.64

6.19*

5.73

8.24

2.99

3.90

I 91 / ' 91

.85

.81

.13

.13

100. 27

B

48.76

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

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

100. 21

E

47.94

18.90

2.21

8.59

8.21

9.86

2.81

.29

.39

.74

.57

.15

trace

none

none

100. 66

F

48.35

15.47

4.80

7.58

8.15

8.81

3.09

.95

.28

.73

1.33

.33

.07

.21

.02

.06

.03

100. 26

G

52.40

13. 55

2.73

9.79

5.53

10. 01

2.32

.40

.62

1.05

1.08

.12

.26

trace?

none

.13

99.99

Norms.

Q......................

or. ...................

ab....................

an....................

TIP

di.... .................

hv.--». "".."»

ol.....................

il....... ........ .......

QY\

A

22.8

19.4

24.5

3.1

9.4

12.8

3.7

1.7

1 q

B

17.2

26.7

19.2

1.1

14.1

6.5

8.6

3.1

1.3

c

6.9

9.5

25.2

' 26.7

9.6

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

23.6

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

2.2

19.4

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 420-427.
436 THE DATA OF GEOCHEMISTKY.

Analyses of basaltic rocks.

A.Kulaite,Kula,Lydia,AsiaMinor. Described and analyzed by H. S.Washington, Jour. Geology, vol. 8, 

1900, p. 613. Contains, in percentages,anorthite, 17.9; albite, 8.4; orthoclase, 23.4; nephelite,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, loc. 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.

C. 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 

of nephelite. Symbols, IV,15 .1.2. 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,22 .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 .................

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

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

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

Na20.................

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

H20..................

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

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

PA- - - ---- - s?. ?.......... .......

S03 ..................

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

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

v2o3 .................

Cr,03 ------------------

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

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

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

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

Li20..................

A

48.35

19.94

2.48

5.25

5.15

7.98

5.47

3.99

.16

.22

.12

.84

99.95

B

49.90

19.89

2.55

4.78

5.05

7.21

5.60

3.74

.13

.19

.93

<

99.97

C

45.11

12. 44

2.67

9.36

11.56

10.61

3.05

1.01

.16

.78

2.34

.51

.01

.11

.04

.22

.04

trace

100. 02

D

46.04

12.23

3.86

4.60

10.38

8.97

2.42

5.77

| 2.87

.64

1.14

trace

.11

.48

.25

99.76

E

41.43

9.80

3.28

5.15

13.40

16.62

1.64

7.40.

},n

.29

none

100. 12

F

40.32

9.46

4.75

7.48

18.12

10.55

2.62

1.10

.57

1.25

2.66

.68

.01

trace

.05

.04

.25

.06

.06

.03

trace

100. 09

G

39.92

8.60

4.40

8.00

20.17

10.68

1.91

1.03

.43

1.45

 2.70

.51

fvQpO

.07

.04

.14

.24

.06

.06

.04

trace

100. 45

H

37.96

10.14

3.69

7.59

14.69

16.28

2.18

.69

.39

1.82

2.93

1.13

.04 -.03

frflpp

.07

.05

.08

.22

.04

.06

.05

trace

100. 13
IGNEOUS ROCKS. 437

Analyses of basaltic rocks Continued. 

Norms.

or.....................

ne ...................

kr> K^... .................

Ic....................

ac.. ...................

di............. .........

ol......... ...........

il.......... ...........

ap ...................

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

11.1

11.9

2.6

29.3

26.2

7.0

5.1

1.6

G

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 '' leucite 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.
438 THE DATA OF GEOCHEMISTRY.

Analyses of diabase.

A. Turnpike Creek, Kittitas County, Washington. Analysis by W. F. Hillebrand. 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 chlorite, v/ith probably a little 

quartz. Symbol, II.4.4.3. Bandose.

C. Shoshone Canyon, Yellowstone National Park. Analysis by Hillebrand. Contains, according to 

Arnold Hague and T. A. Jaggar, plagioclase, augite, and chlorite. Symbol, H.5.3.4. Andosc.

D. Aroostook Falls, Maine. Analysis by Hillebrand. Description by H. E. Gregory. Contains plagioclase, pyroxene, pyrite, apatite, chlorite, and a little calcite. Symbol, H.5.3.5. BeerbacJiose.

E. Diabase porphyry, near Milton, Sierra County, California. Analysis by Hillebrand. Described by 

H. W. Turner. Contains plagioclase, augite, and hornblende. Symbol, III.5.3.4. Camptonose.

F. Mount Ascutney, Vermont. Analysis by Hillebrand. Described by R. A. Daly. Contains plagioclase, augite, and magnetite. Symbol, IH.5.4.3. Auvergnose.

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

Al f)

Fe2 03 . .......................

FeO..... .....................

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

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

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

K2 0..........................

H2 0.........................

H2 0+........................

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

C02 ..........................

P f)

01............................

V2 03 .. .......................

MnO... ..........:...........

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

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

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

lAyO. ........................

Fe&i...... ...................

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

.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

.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

.14

trace

.11

.06

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

10.86

10.32

2.00

1.63

.17

1.16

.60

.21

.21

.04

.07

99.92

F

49.63

14.40

2.85

8.06

7.25

9.28

2.47

.70

.27

1.47

1.68

1.36

. .25

.07

.17

.04

.22

100. 17

Norms.

Q.. ..........................

ab............................

di...........................

hy. .........................

of...........................

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

11.1

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

1.5

4.4

21.0

25.9

16.6

19.8

4.2

3.2
IGNEOUS BOOKS. 439

THE GAB BROS.

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 

monoclinic 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, p. 340,1900. Nearly pure plagioclase. Magmatic symbol, 1.5.5. Canadase.

B. Gabbro, near Emigrant Gap, Placer County, California. Analysis by W. F. Hillebrand. Described 

by W. Lindgren. Contains biotite, hypersthene, diallage, plagioclase, and orthodase. Symbol, II.5.3.4. 

Anilose,

C. Gabbro, Emigrant Gap, California. Analysis by Hillebrand. Described by Lindgren. Contains 

hypersthene, diallage, plagioclase, and orthodase. Symbol, III.4.3.4. Vaalose.

D. Norite, Elizabethtown, Essex County, New York. Analysis by Hillebrand. Described by J. F. 

Kemp. Contains labradorite, hypersthene, garnets, augite, hornblende, biotite, magnetite, and apatite. 

Symbol, III.5.3.4. Camptonose.

E. Bronzite norite, Crystal Falls, Michigan. Analysis by G. Steiger. Described by J. M. Clements 

and H. L. Smyth. Contains bronzite, hornblende, and labradorite. Symbol, III.5.4.3. Auvergnose.

F. Olivine gabbro, Birch Lake, Minnesota. Analysis- by H. N. Stokes. Contains a largo proportion 

of diallage and olivine. Symbol, III.5.4.3. Auvergnose.

G. Hypersthene gabbro, Wetheredville, Maryland. Analysis by Hillebrand. Described by G. H. 

Williams. Contains hypersthene, diallage, plagioclase, magnetite, and apatite. Symbol, III.5.5. Kedabeltasc.

H. Hypersthene gabbro, Gunflint Lake, Minnesota. Analysis by Stokes. Described by W. S. Bayley. 

Contains hyperstheno, biotite, diallage, magnetite, and plagioclase. Symbol, IV. 1.1.2. Cookose.

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

Al O

Fe2 03 -----------------

FpO

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

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

Na O

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

H2 0................

'SL&+. ..............

TiO

rn

P2 05 ........ ..........

S......... ...........

Vn03 .................

Ora08 - --.--- -- -----

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

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

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

SrO...<...............

LiaO......... .........

A

45.78

30.39

1.33

1.22

2.14

16. 66

1. 66

.10 }.«

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

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

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

trace

99.98

E

43. 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

.16

100. 03

G

44.76

18.82

2.19

4.73

11. 32

14. 58

.89

.11

.17

2.36

.13

none

.08

.15

100. 29

H

46.96

14. 13

.76

14.95

15.97

2.32

.35

1. 68

.07

1.26

.62

.03

trace

.93

.06

100. 09
440

Analyses of gabbros Continued. 

Norms.

Q............. ........

or. ..................

ab...................

an ...................

ne. ..................

C...... ...............

di....................

hy.. ........ .........

ol....................

mt.... ....... .........

il......... ............

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

7.5

57.5

6.0

1.2

1.1

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 rnineralogical classification. It 

separates things which, with the exception above noted, are essentially distinct.

FEMIC ROCKS.

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 hornblende and olivine; in wehrlite, diallage and olivine; in Iherzolite, 

diopside, a rhombic pyroxene, and olivine. Websterite contains 

bronzite and diopside, and so forms the pjroxenite end of the series. 

The nomenclature is varied, and the terms are not rigorously used. 

Hornblendite is a femic rock in which hornblende is the prevailing 

mineral.1 The following table deals with the rocks in which pyroxenes predominate:

i Two analyses of hornblendites are given in Washington's tables, Prof. Paper U. S. Geol. Survey No. 14, 

1903, pp. 345,359.
IGNEOUS BOCKS. 441

Analyses of pyroxenites.

A. Cortlandtite, Belchertown, Massachusetts. Analysis by L. G. Eakihs. Described by B.K.Emerson. 

Contains hornblende, pyroxene, biotite, olivine, and magnetite. Magmatic symbol, IV.12.1.1. Belcherose.

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.ls.1.2. WeMose.

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.

D. Pyroxenite, Baltimore County, Maryland. Analysis by J. E. Whitfleld. Described by G. H. 

Williams. Contains hypersthene and diallage. Symbol, V.li.1.1. Maricose.

E. Websterite, Webster, North Carolina. Analysis by E. A. Schneider. Described by Williams. 

Consists of diopside and bronzite. Symbol, V.l'.2.1. Websterose. '

F. Websterite, Oakwood, Maryland. Analysis by W. F. Hillebrand. Described by A. G. Leonard. 

Contains hypersthene and diallage. Symbol, V.I1 .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.12 .1.1. Baltimoriase.

H. Pyroxenite, Baltimore County, Maryland. Analysis by Whitfleld. Described by Williams. Contains hypersthene and diallage. Symbol, V.V.1.2. Baltimorose.

SiOa . ...............

Al O

FeA.. .............

FeO.................

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

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

NaA -. -- --- -- 

K /s

HaO-. ..............

^0+- --------------

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

P O

coa .. ...............

s. ...................

so8 .................. ci................... VA... ..............

Cr A ................ Mno.. ..............

(NiGo)0. ............

FeS2 . ...............

A

48.63

5.32

2.91

3.90

21.79

13.04

.34

.23.

} 2.81

.47

.21

.36

.12

100. 13

B

48.95

5.69

1 90

12.11

23.49

5.33

-1.58

.79

1 18 / ' ih

.81

.12

.05

.08

.16

100. 54

C

46.13

4.69

.73

16.87

25.17

4.41

.08

trace

} 1.38

.73

.07

.24

.04

trace

flQ

100. 63

D

51.94

2.53

2.88

9.38

25.97

3.60

} 2.82

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

} .50

1.08

7.64

.12

trace

.44

.19

100. 63

H

50.80

3.40

1 39

8.11

22.77

12.31

>trace

1 W f . U&

none

trace

.24

.32

.17

100. 03

Norms.

Q . ................

or. ..................

di.......... ..........

hv.. .................

ol. ...................

mt. .................

H.. .................

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

.6

6.7

8.9

76.4

2.8

E

1.7

2.6

32.7

57.1

5.1

F

.6

1.0

3.2

48.9

41.4

2.1

.5

G

4.2

2.2

22.6

34.3

16.3

8.4

3.0

H

9.2

41.4

33.8

12.2

2.1
442 THE DATA OP GEOCHEMISTRY.

The general presence of chromium and nickel in 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, Hchester, Maryland. Analysis by W. F. Hillebrand. Described by G. H. Williams. 

. Contains olivine, pyroxene, and hornblende partly altered to talc. Magmatic symbol, IV.1A1.1. 

Cortlandtosc.

B. Peridotite, near Silver CliS, Colorado. Analysis by L. G. Eakins. Described by W. Cross. Contains 

hornblende, biotite, hypersthene, olivine, a little plagioclase, apatite, pyrrhotite, and slllimanite. Symbol, 

IV.1U.2. Custerose.

C. Peridotite, near Opin Lake, Michigan. Analysis by Hillebrand. Described by C. R. 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, muscovite, magnetite, calcite, chlorite, and 

other secondary products. Symbol, IV.2*.1.2. Subrang of Casseliase.

E. Saxonite, Douglas County, Oregon. Analysis by F. W. Clarke. Described by J. S. Diller and F.MV. 

Clarke. Contains olivine and enstatite, with a little magnetite and chromite. Symbol, V.1<.1.1.

F. Dunite, Corundum Hill, North Carolina. Analysis and description by 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 olivino and serpentine, with magnetite, magnesite, and calcite. Symbol, V. 1M.1. Dunose.

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

AlA 

Pe208 .......... .......

FeO. .................

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

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

Na20..... .............

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

H20.................

K?0+.... ............

TiO

C02 ...................

PA..---.-------.-

01....................

Cr203 ----- ------------

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

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

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

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

3.70

.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

.10

99.80

F

40.11

.88

1.20

6.09

48.58

2.74

.is

.56

100. 34

G

38.40

.29

3.42

6.69

45.23

.35

. Uo

.24

4.11

1.10

trace

.06

.07

.24

.10

100. 38
IGNEOUS BOCKS. 443

Analyses of peridotites Continued.

Norms.

ab....................

an....................

ne....................

Ic

C......... ............

di............... ......

hy....................

ol............ .........

hm. ..................

il.....................

ap....................

A

0.6

3.1

10.6

4.4

16.8

47.9

5.1

.9

B

5.0

12.6

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

9.6

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 Q

4.7

89.7

1.6

.8

G

0.8

.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 

tin's 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 ROCKS.

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 corundum 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.

i Jour. Geology, vol. 16,1908, p. 124.
444 THE DATA Or GEOCHEMISTRY.

Analyses of basic and titaniferous rocks.

A. Corundum pegmatite, Ural Mountains, Siberia. Described and analyzed by J. Morozewicz, Min. 

pet. Mitt., vol. 18, p. 219, 1898. 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 a little spinel, anorthite, biotite, and zircon. Symbol, I1 .5.5. Kyschtymase.

C. Hmenite norite, Soggendal. Norway. Described and analyzed by C. F. Kolderup, Bergens Museums 

Aarbog, 1896, p. 1G5. Contains, in approximate percentages, ilmenite, 37.5; hypersthene, 40.1; anorthite, 

11; albite, 8.7; orthoclase, 0.9. Symbol, IV.SU.S. Bergemse.

D. Titaniferous iron ore, Lincoln Pond, Essex County, New York. Analysis by W. F. Hillebrand. 

Described by J. F. Kemp. Symbol, IV.42 .1.4. Adirondackiase.

E. Titaniferous iron ore, Elizabethtown, New York. Analysis by Hillebrand. Described by Kemp. 

Symbol, IV.4'.1.4. Champlainiase.

F. Magnetite spinellite, Routivaara, Finland. Analyzed and described by W. Petersson, Geol. Foren. 

Forhandl., vol. 15, p. 49, 1893. Symbol, V.5M.4. No magmatic name assigned.

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

Al O

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

FeO

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

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

Na20........... ..............

K20..... ..........:..........

H20............... ...........

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

C02 ...... ....................

p o

S............. ................ ci........................... VA-- .-- --.. ---.--- ---- 

rv n

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

Corundum. . ..................

A

40.06

13.65

.35

.15

.30

3.71

5.20

.46

35.40

99.28

B

16.80

13.89

.76

.ei

7.26

.38

.13

.76

059.51

100. 10

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

i.68

16.45

.17

.02

.09

trace

.61

.55

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

a Including a little spinel.

Norms.

or............................

ab. ...........................

Ic. ..........................

c............................

hy.... ......... ...............

ol. ..........................

rut..... ......................

il.. ..........................

a

7-\ .

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

44.5

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
IGNEOUS BOCKS. 445

The cumberlandite1 of Cumberland, Rhode Island, a peridotite rich 

in titanif erous magnetite, also belongs in this group; and many other 

similar mixtures are known. A magnetite syenite porphyiy (kirunose), described by P. Geijer,2 contains 63.8 per cent of albite, with 

38.7 of magnetite, and minor accessories. A unique dike rock, found 

in Nelson County, Virginia,3 consists almost entirely of apatite and 

rutile, or of apatite and ilmenite. One sample of this nelsonite contained 57.9 per cent of rutile and 38.3 of apatite. The New York 

(Adirondack) ores,4 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 

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 upon the separation of corundum, iolite, etc., from 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.

Potassium. ........

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

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

A/To on PQI 11 TYI

Maximum silica.

Orthoclase, KAlSi,03 . .........

Albite, NaAlSi308 . ............

Enstatite, MgSi03". ...........

Acmite, FeNaSi206 . ..........

Albite, NaAlSigOg. ............

Minimum silica.

Leucite, KAlSi20Q . 

Nephelite, NaAlSi04 . 

Anorthite, CaAl2Si2 08 .« 

Forsterite, Mg2Si04\r, 1 - Fayalite, Fe|i04 4j°llvlneMagnetite, Fe304 . 

Corundum, A1203 .

a Melilite, a basic silicate, is here left purposely out of account, and so, too, is akermanite.

i See B. L. Johnson and C. H. Warren, Am. Jour. Sci., 4th ser., vol. 25,1906, p. 1, for description and 

analysis of the Cumberland rock.

a Oeol. Kiruna district, Stockholm, 1910, p. 60.

s Described by T. L. Watson and S. Taber, Bull. U. S. Geol. Survey No. 430,1910, p. 206.

4 Recent 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.
446 THE DATA OF GEOCHEMISTRY.

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 hi 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 

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. Feldspars 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
IGNEOUS ROCKS. 447

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 biotite; sodium may yield albite, 

nephelite, analcite, alkali hornblende, or acmite; calcium appears in 

p3TOxene, amphibole, anorthite, or melilite; magnesium in pyroxene, 

amphibole, olivine, or biotite; iron in pyroxene, amphibole, olivine, 

acmite, 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-, rneta-, and. tri-silicates are then capable of 

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 

acids 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 titanatea, and iron ores. These are almost invariably 

the first minerals to crystallize.

i Elemente der Gesteinslehre, 1898, p. 40.
448 THE DATA OF GEOCHEMISTRY.

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 tha metasilicates; olivine, for example, separating before pyroxene.

3. Feldspars and lenads in the order anorthite, plagioclase, alkali feldspars, nephelite, leucite.

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 aluinosilicates, 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.

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 proportion 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 the 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; hi 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.
IGNEOUS EOCKS. 449

Two rocks of relatively simple composition are the following, for 

which data are given in Survey Bulletin 419, and also in Washington's tables.

A. Granite-syenite porphyry, Little Rocky Mountains, Montana. Analysis by H.N. Stokes. Described 

by W. H. Weed and L. V. Pirsson. Contains 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. Toscanose.

Analyses. Norms.

SiOa ...................

Al O

Fe203 --- - 

FpO

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

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

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

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

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

Na.,0.................. K26..................

HaO.................

HaO+................

TiOa ...................

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

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

Q. ...................

an.... ................

c......................

hy....................

hm. ..................

A

20.2

27.8

40.9

5.0

3.5

q

.2

.4

B

27.8

oq Q

9Q Q

13 1

.9

q q

q

In calculating the actual composition of these rocks, it is best to 

first eliminate the accessories. Zr02 is calculated as zircon, Fe2 03 

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)2KHSi3012 . 

Upon comparing KjO 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.

101381° Bull. 491 11 29
450 THE DATA OF GEOCHEMISTBY.

Calculated composition of rocks represented in preceding table.

("J 1 1 O !«+ 17

Albite .........................................................

Biotite ........................................................

MgSi03 ... .....................................................

Titanite. .......................................................

Rutile. . ........................................................

Magnetite .....................................................

Hematite. ......................................................

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

.24

.93

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 component 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 biotite, 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 tho 

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 proportions of 

the elements may be calculated, and the results obtained, c.an. b.eo
 IGNEOUS ROCKS. 451

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 for 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.

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 unsatisfactory. See also A. Rosiwal, Verhandl. K:-k. geol. Reichsanstalt, 1898, p. 143.
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 composition, 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 vplcanic 

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. 265.

2 See ante, pp. 48 et seq.

452
THE DECOMPOSITION OF BOCKS. 453

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 water at different temperatures.

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 carbon 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,

» 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.

»W. 0. 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.
454 THE DATA OF GEOCHEMISTKY.

and intensify the activity of the percolating waters. The sulphates 

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 R. 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 ser., vol. 5, 1848, p. 401.

2 The temperature at which the experiment was conducted was 60°, presumably Fahrenheit.

3 Etudes synthgtiques de geologie experimentale, pp. 271-275. See also p. 252 for an experiment upon 

the solubility of granite.

4 Neues Jahrb., 1867, pp. 77, 769.

5 Jahrb. K.-k. geol. Reichsanstalt, vol. 27, Min. Mitt., 1877, p. 25. Miiller gives a good summary of previous 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. Cam,eron and J. M. Bell, is in 

Bull. No. 30, Bureau of Soils, U. S. Dept. Agric., 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, pyrophyllite, nontronite, etc., giro acid 

reactions.
THE DECOMPOSITION OF BOOKS. 

Material extracted from minerals by carbonated water.

455

Oligoclase. .

Hornblende

Do.....

Do.....

Do......

Olivine. . ..

Serpentine.

Si02.

0. 1552

.237

.419

.873

.354

AUOs.

0. 1368

9. 1713

trace

K2 0.

1. 3527

trace

NaaO.

2.367

MgO.

1.291

2.649

CaO.

3.213

8.528

1.696

2.168

1.946

PsO,.

1.417

1.822

2.12

FeO.

4.829

.942

2.428

8.733

1.527

Sum.

0.328

.533

1.536

.307

1.821

1.529

2.018

1.976

2.111

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 possiblity of gain by hydration seems not 

to have been considered. The data given are as follows:

Relative solubility of various minerals in water.

Epidote .......................................................

Chlorite .......................................................

Talc...........................................................

Muscovite .....................................................

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

1 Inang. Diss., Leipzig, 1882.

2 Quart. Jour. Geol. Soc., vol. 45,1889, p. 363. 

a Proc. Roy. Soc. Edinburgh, vol. 15, 1888, p. 436. 

< Trans. Edinburgh Geol. Soc., vol. 5,1887, p. 282.
456 THE DATA OF GEOCHEMISTRY.

the most soluble; hornblende and augite were acted upon even more 

rapidly. These observations seem to be in harmony with those of 

Muller, 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, sodalite, 

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 nitrate 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 ' i O

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

1 Min. pet. Mitt., vol. 11,1890, p. 319.

2 Bull. U. S. Geol. Survey No. 1C7,1900, p. 156.

3 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 electrolytic extraction 

of potash from feldspars. Other papers on the solubility of rocks are by W. G. Levison, Bull. New York 

Mineralogical 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; and F. Sicha, 

Inaug. Diss., Leipzig, 1891.
THE DECOMPOSITION OF ROCKS. 45*7

rule can be laid down to determine what the effects of waters in any 

particular case will be.

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 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 

iss 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

1 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. Scl., 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.

3 S. J. Thugutt, Mineralchemische Studien, 1901, p. 104.

8 Am. Jour. Sci., 4th ser., vol. 16,1903, p. 181.
458 THE DATA OF GEOCHEMISTBY.

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* in certain granites of the 

District of Columbia, and by O. A. Derby 2 at railway cuttings in 

Brazil. In the latter case, the rocks, when first uncovered, were so 

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 converted 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 

are not entirely altered, and the loose products therefore exhibit 

many variations. In general terms, the streams separate the disintegrated 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 reconsohdation. 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 promptness 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.

Vi

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 

of organic matter derived from the decay of vegetation. This

» Bull. Geol. Soc. America, vol. 6,1895, p. 321.

* Jour. Geology, vol. 4,1896, 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.
THE DECOMPOSITION OF ROCKS. 450

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 land. 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 waters 

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 their 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 

mechanically in the work of disintegration. 3 The roots, moreover, 

commonly contain organic acids, which act with much vigor upon

1 See E. W. Hilgard, Am. Jour. Sci., 4th ser., vol. 2,1896, p. 100. Hllgard suggests that the inclusions of 

carbon dioxide found in quartz may supply notable quantities of that substance to underground waters.

*In addition to previous references, see also W. B. Schmidt, Min. pet. Mitt., vol. 4,1882, p. 1, on the action 

of sulphurous acid upon volcanic rocks. The action of hot solutions, not necessarily acid, has been compared with the effects of weathering by E. Steidtmann; Econ. Geology, vol. 2,1908, p. 381. An important 

memoir on weathering, by K. D. Glinka, is in Trav. Soc. Imp. Nat. St. PStersbourg, vol. 34, 1906, p. 1. 

On the decomposition of basalt see H. Stremme, Monatsh. Deutsch. geol. Gesell.. 1910, p. 180.

3See A. Geikie, Text-book of geology, 4th ed., p. 600, and G. P. Merrill, Rocks, rock weathering, and 

soils, p. 201. '
460 THE DATA OF GEOCHEMISTRY.

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 1 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 determinable by analysis.2

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, humic, ulmic, crenic and apocrenic acids, 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 3 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 4 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.5

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 6 has found the 

decayed rocks of Alpine summits, where no other life exists, swarm1 Annals New York Acad. Sci., vol. 1,1877, p. 1; vol. 2,1880, p. 1.

2 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 Jahresber, 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.

a Chem. Abstr., 1909, p. 2600. From Jour. exp. Landw., vol. 9,1908, p. 272.

«Neues Jahrb., Beil. Bd. 31,1910, p. 1, and Jour, prakt. Chemie, 2d ser., vol. 82,1910, p. 414.

6 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. Geologie, 1909, p. 353; 

1910, p. 389. The recent literature upon the humus acids is very voluminous.

a Annales chim. phys., 6th ser., vol. 11,1887, p. 136; Compt. Rend., vol. 110,1890, p. 1370.
THE DECOMPOSITION OF BOCKS. ' 461

ing with the nitrifying ferment. The limestones and micaceous 

schists of the Pic du Midi, in the Pyrenees, and the decayed calcareous schists 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 1 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,2 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,3 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 *nay 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 4 and J. C. Branner,5 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, 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 drain1 Zeitschr. angew. Chemie, 1899, p. 402.

8 Am. Jour. Sci., 4th ser., vol. 3,1897, p. 438.

8 See ante, p. 102.

« Am. Geologist, vol. 3,1889, p. 351.

 Bull. Geol. Soc. America, vol. 7,1896, p. 255; vol. 21,1910, p. 449.
462 THE DATA OF GEOCHEMISTRY.

ing, grading, irrigating, fertilizing, and cultivating the soil, by tunneling, quarrying, and mining, the processes of rock decomposition 

are promoted hi 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 hi 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.

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:

' For a good general discussion of the data, see G. P. Merrill, Rocks, rock weathering, and soils, pp. 

206-240. See, also, papers by J. Lemberg, Zeitschr. Deutsch. geol. Gesell., vol. 27,1875, p. 581; vol. 28, 

1876, p. 519; vol. 35,1883, 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 BOCKS. 463

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, feldspars, 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. Analyses 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. Kept. Geol. 

Survey Arkansas, 1890, vol. 2, pp. 81-82. a, The fresh rock, analysis 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.

Si09 ................

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

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

FeO.................

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

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

Na20.................

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

TiO,.. ..............

p r2o us ................

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

Al O

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

FeO .................

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

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

Na20................

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

H20..................

Tin

P ^o... O ...............

I

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

f>(\ OO 69. do

14.33

3.60

2.44

3.21

2.70

2.67

1.22

undet.

.10

99.60

c

b

58.50

25.71

1 3.74

trace

.44

1.37

1.96

5.85

97.57

1

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

L

C

65.69

15.23

1 4.39

2.64

2.63

2.12

2.00

4.70

.31

.05

99.76

I

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

9Q 84.

1 3.69

4.60

4.41

3. 36

2.49'

8.12

99.90

)

b

58.16

15.03

10.59

1.99

4.57

2.56

1.68

1.77

3.52

.43

.07

100. 37
464 THE DATA OF GEOCHEMISTRY.

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, limenite, 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.

F. Diorite, Albemarle County, Virginia. Described and analyzed by G. P. Merrill, Rocks, 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 by G. Attwood, Quart. Jour. Geol. Soc., vol. 35, 

1879, p. 586. 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, The fresh rock; b, decomposed rock. Holland and Dickson also give data relative 

to the decomposition of a granite and a sandstone.

I. Augite diorite, Magnetberg, southern Urals. Described by J. Morozewicz, abstract in Zeitschr. Kryst. 

Min., vol. 39,1904, p. 612. 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 .......

A1 O

Fe203 ......

FeO.......

MgO.......

CaO.......

Na.0......

K26........

p o

MnO.......

SiO,. ......

A1__ 2fi 0_ 3O ......

Fe203 ......

FeO.......

MgO.......

CaO.......

Na-0......

K20. .......

H20...... 

H20+..... 

Ti02 .......

C02 ........

MnO.......

a

49.57

15.37

12.34

7.41

9.65

1.99

.85

.17 

3.10

\VQC*C*

« 100. 45

G

b

41.77

19.34

13.21

4.63

5.01

4.98

.83

.69

2.55 

7.30

a 100. 31

C

43.'46

18. 39

20.43

3.46

2.37

.14

.59

3.39 

7.95

« 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

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 1? 70 

2.82

6.03

3.93

1.75

3.73

.70

.52

99.81

H

b

44.93

16.27

13.37

6.40

1.84

2.03

.84

| 12. 55 

1.34

.28

99.85

c

36.61

40. 68

4.02

3.44

2.14

1.82

10.97

99.68

a

4fi Q7

16.16

10.66

4.38

4.56

9.02

4.47

1.26

} 1.74 

.14

.75

100. 11

P

a

46.75

17.61

) 16. 79 '

I

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 94

1.52

| 2.24 

.07

.68

100. 04

b

42.44

25.51

1 19.20

.21

.37

.56

.49

10.92

.29

99.99

c

47 99

on OQ

5.51

2.02

4.39

6.93

2.56

1.52

} 8.78 

trace

.66

99.68

Including traces of Cu and S. P absent.
THE DECOMPOSITION OF EOCKS. 465

All of 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 be small, when actually they are quite noteworthy. 

The apparent gains in alumina are only relative, and so, too, 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 

one hundred.

Results of decomposition of certain rocks.

I. Percentage of rock lost.

SiO........................... AI n

FeO, Fea08 .....................

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

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

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

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

K26.... .......................

P f)

Granite.

10.50

.46

.36

.81

.77

.85

.04

13.79

Gneiss.

31.90

1.30

.80

4.44

2.68

3.55

44.67

Diabase.

8.48

standard

2.42

.32

.68

1.83

.50

.62

.08

14.93

Diorite.

17.43

3.53

4.97

9.20

2.17

.21

37.51

101381° Bull. 491 11 30
466 THE DATA OF GEOCHEMISTRY.

Results of decomposition of certain rocks Continued. 

II. Percentage loss of each constituent.

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

A1A-.......................

FeO, Fea08 .....................

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

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

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

Na20.........................

KJ)................ ...........

p o

Granite.

14.89

3.23

standard

1.49

25.21

28.62

31.98

40.00

Gneiss.

52.45

standard

14.35

74.70

100. 00

95.03

83.52

Diabase.

18.03

18.10

41.57

21.70

25.89

12.83

29.15

11.39

Diorite.

37.31

- 21. 03

97.17

97.30

84.87

38.75

19. 87

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 taken 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
THE DECOMPOSITION OF BOOKS. 467

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 

powder, but much of the debris 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 3 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.

b

Insoluble in HC1 ............................................

Soluble Si02 . ....... ........................................

AljOj......................................................

Fe.,0,.... ..................................................

Mna04 .. ....................................................

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

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

Na2 0. . ....................................................

K2 0........................................................

P O

so...... ..................................................

A

84. 031

4.212

4.296

3.131

.133

.225

.108

.091

.216

.113

.052

3.644

100. 252

B

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.

i Report on the relations of soil to climate: Bull. No. 3, U. S. Weather Bureau, 1892. 

a See I. C. Russell, Bull. Geol. Soc. America, vol. 1,1890, p. 135. Also compare 0. P, Merrill, Rocks, 

rock weathering, and soils, pp. 278, 285. 

8 Op. cit., p. 30,
468 THE DATA OF GEOCHEMISTBY.

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, H4Fe2Si2O9 , are 

perhaps the most important. 1 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, 

yielding a ferric hydroxide, limonite, as a final product of aqueous 

action. According to Weinschenk, mixtures of kaolinite and nontronite are sometimes found, in 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. Rosier,2 kaolinite is only produced by pneumatolytic action that is, 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. F. H. Butler,3 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. Wtist 4 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,5 

J. E. Barnitzke,6 F. Weiss,7 K. Endell,8 and others. H. Stremme 9 

recognizes the almost self-evident fact that any of the suggested processes may be operative, weathering, pneumatolytic action, and 

kaolinization by moor waters, but ascribes their efficiency in all 

cases to the chemical activity of carbonic acid. Jointly with

1 This equivalency between kaolinite and nontronite was suggested by E. Weinschenk, Zeitschr. Kryst. 

Min., vol. 28,1897, p. 160. A. Bergeat, however (Centralbl. Min., Geol. u. Pal., 1909, p. 161), describing 

nontronite derived from wollastonite, assigns it a different formula HaFejSigOjs.

2 Neues Jahrb., Beil. Bd. 15,1902, p. 231. RSsler gives a bibliography relative to kaolinization, embracing 

303 titles. See also O. Stutzer, Zeitschr. prakt. Geologic, 1905, p. 333, who accepts Rb'sler's view, and J. M. 

van Bemmelen, Zeitschr. anorg. Chemie, vol. 66, 1910, p. 322. Van Bemmelen, however, does not accept 

the theory exclusively, but admits that weathering may also produce kaolin. In a recent paper, Zeitschr. 

prakt. Geologic, 1908, p. 251, Rosier defends his views.

3 Min. Mag., vol. 15,1908, p. 128.

< Zeitschr. prakt. Geologie, 1907, p. 19.

5 Jour, prakt. Chemie, ser. 2, vol. 78,1908, p. 280.

6 Zeitschr. prakt. Geologie, 1909, p. 457.

' Idem, 1910, p. 353.

s Sprechsaal, Nos. 19, 20,1910.

9 Zeitschr. prakt. Geologie, 1908, pp. 122, 443,
THE DECOMPOSITION OF BOCKS. 469

C. Gagel i Stremme describes one instance of kaolinization by the 

waters of a cold carbonated spring. V. Selle,2 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 can fit all its occurrences.

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.3

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.4 W J McGee 5 compares laterite with 

the ferruginous clays and soils of the upper Mississippi, and F. R. 

Mallet 6 regards the iron ores associated with the basalts of Ulster 

as having a lateritic character. W. Maxwell,7 describing the red 

soils of the Hawaiian Islands, which are derived from lavas by 

the action of volcanic acids, points out their similarity to laterite. 

T. H. Holland 8 suggests that lateritization may be due, in part at

1 Centralbl. Min., Geol. u. Pal., 1909, p. 427.

2 Jour. Chem. Soc., vol. 96, pt. 2, p. 63, abstract from Zeitschr. Naturwiss., vol. 79,1907, p. 321.

" On the constitution of the clay silicates see H. Le Chatelier, Zeitschr. physikal. Chemie, vol. 1,1887, 

p. 396.

* See R. D. Oldham, Manual of the geology of India, 2d ed., 1893, pp. 348-370. P. Lake (Mem. Oeol. 

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 ser., 

Heft 62,1909.

o Geol. Mag., 1880, p. 310.

0 Rec. Geol. Survey India, vol. 14,1881, p. 139.

7 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.

s Geol. Mag., 1903, p. 59.
470 THE DATA OF GEOCHEMISTRY.

least, to the activity of bacilli or other micro-organisms which could 

live in a warm climate but not in colder regions. J. Walther x and 

S. Passarge 2 call attention to the relatively large proportion of nitric 

acid in rainfall during tropical thunderstorms, and regard it as a 

possible agent 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 

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 3 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,4 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,5 the laterite of Malabar is produced in situ from gneiss. M. 

Bauer 6 has described "granite laterite" and "diorite laterite" from 

the Seychelle Islands; in Surinam, according to G. C. Du Bois,7 its

usual parent is diabase; in the Hawaiian Islands it is formed from

recent lavas.8 There are many analyses of laterite, some of them

1 Verhandl. Gesell. Erdkunde, vol. 1.6,1889, p. 318.

2 Kept. Sixth Internat. Geog. Cong., London, 1S95, p. 671.

s Bull. Dept. Agr., Indes N6erlandaises, No. 28,1909. An earlier paper on laterite is in No. 17,1908.

< Geol. Mag., 1910, pp. 439, 488, 553. On laterite from diabase, idem, 1911, p. 120.

5 Mem.'Geol. Survey India,vol. 24, pt. 3,1890, p. 17. M. Maclaren(Geol. Mag., 1906, p. 536) regards the 

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. Met., vol. 19,1910, 

p. 432), who regards the hydroxides of laterite as deposited from ascending, mineralized waters. Other 

recent papers on laterite are by J. R. Kilroe (Geol. Mag., 1908, p. 534), J. Chautard (Compt. Rend. Soc. 

ind.min., April, 1908, p. 119), Chautard and P. Lemoine(Bull. Soc.ind.min., 4thser.,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 Beinmelen (Zeitschr. anorg. Chemie, vol. 66,1910, p. 322) discusses laterite and 

kaolin. See also R. Lenz, Inaug. Diss., Freiburg, 1908.

6 Neues Jahrb., 1898, pt. 2, p. 192. Also a later paper by Bauer in Neues Jahrb., Festband, 1907, p. 33.

7 Min. pet. Mitt., vol. 22,1903, p. 1. Du Bois gives several analyses of laterite.

s 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. Dunst'an (Rec. Geol. Survey 

India, vol. 37, pt. 2,1908, p. 213) found unusual amounts of TiOa, up to 13.76 per cent.
THE DECOMPOSITION OF BOCKS. 471

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:

Analyses of laterite.

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

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

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

H20 ......................................................

Granite laterite.

52.06

29.49

4.64

14. 40

100. 59

Diorite laterite.

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 R03H3, 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, A103H3 ; diaspore, A102H, and limonite, 

Fe4H6 09 . 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 a bauxite, and C, D, E, and F laterite, found in situ.

Analyses of gibbsite, bauxite, and laterite.

Quartz.......................

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

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

FeA... .....................

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

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

Ti08 .........................

H30..........................

A

2.78

62.80

.44

.03

.20

.04

33.74

100. 03

B

0.93

67.88

4.09

.36

1.04

26.47

100. 77

C

3.90

54.80

13.75

.35

.38

26:82

100. 00

D

0.37

43.83

26.61

.36

4.45

23.88

100. 00

E

10.52

.23

35.38

34.27

.40

.10

19.00

100. 00

F

0.90

26.27

56.01

.20

.64

1.59

14.39

100. 00

1 Geol. Mag., 1903, p. 154. Only a selection from among a large number of analyses can be given here. 

See also H. Warth, Min. Mag., vol., 13,1902, p. 172, for a description of Indian gibbsite, and L. L. Fermor, 

Rec. Geol. Survey India, vol. 34,1906, p. 167, on gibbsite and manganese ores in laterite.
472 THE DATA OF GEOCHEMISTEY.

The following analyses (G to J) represent detrital laterites:

Analyses of detrital laterites.

Quartz. ........................

Kaolinite. ......................

Balance, identical with bauxite

0

A1203 ..........

FeA.. ........

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

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

TiOa ..... ......

HaO... .........

G

6.67

28.77

15.40

41.50

none

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

9.58

28.38

.01

5.34

100. 00

I

24.39

20.22

47.39

trace

.38

.01

7.61

100.00

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.

1 See T. L. Watson, Bull. No. 11, Geol. Survey Georgia, 1904, for a good summary of the literature of 

bauxite, and a bibliography.

2 See H. Coquand, Bull. Soc. g<5ol. France, 2d ser., vol. 28,1870, p. 98. Aug6, idem, 3d ser., vol. 16,1880, 

p. 345. F. Laur, Trans. Am. Inst. Min. Eng., vol. 24,1894, p. 234. For a later paper by Laur see Compt. 

Rend. Soc. ind. min., 1908, p. 430. On the composition of bauxite see H. Arsandaux, Compt. Rend., vol. 

148,1909, pp. 937,1115. 

s See Coquand and Aug6, as just cited; also S. Meunier, Compt. Rend., vol. 90,1883, p. 1737; Bull. Soc. 

g6ol. France, 3d ser., vol. 17,1888, p. 64. Aug6 argues from an erroneous datum relative to supposed bauxite 

formed by geysers in the Yellowstone National Park. F. Parmentier (Compt. Rend., vol. 115,1892, p. 125) 

has called attention to the occurrence of alumina in mineral waters.
THE DECOMPOSITION OF ROCKS. 473

In several German localities bauxite is found, like laterite, as a 

direct residue from the decomposition of basalt. 1 The bauxite in 

some cases shows the structure of the original rock. Auge" 2 observed 

bauxite at one locality in Auvergne resting on gneiss and partly overlaid by basalt. In Ireland G. A. J. Cole 3 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. 

G. H. Kinahan,4 however, describing other Irish localities where the 

bauxite 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,5 H. McCalley,6 C. W. 

Hayes,7 and T. L. Watson.8 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, 

halloysite, and kaolin, and attributes its formation to heated ascending waters, which have decomposed pyrite in the underlying shales. 

Aluminous solutions were thus brought to the surface, to be precipitated by carbonate of lime. A similar intervention of sulphates has 

been suggested by A. Liebrich 9 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,10 gives added 

emphasis to this suggestion. The alteration of rhyolite to a quartzalunite and a quartz-diaspore rock in the Rosita Hills, Colorado,

1 See A. Streng; Zeitschr. Deutsch. geol. Gesell., vol. 39,1887, p. 621. A. Liebrich, Inaug. Diss., Zurich, 

1891. T. Petersen, Ber. XXVI. Vers. Oberrhein. geol. Vereins, 1893, p. 38. J. Lang, Ber. Deutsch. chem. 

Gesell., vol. 17,1884, p. 2892. 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 Szddeczky, Foldt. Kozl., vol. 35,1905, p. 247, aud R. Lachmann, Zeitschr. 

prakt. Geologic, 1908, p. 353.

2 Loc. cit.

8 Trans. Roy. Dublin Soc., 2d ser., vol. 6,1896, p. 105.

< Trans. Manchester Geol. Soc., vol. 22,1894, p. 458. In the same volume,p. 524, analyses of Irish bauxites 

by W. Peile are given, and there is still another paper on the subject by G. G. Blackwcll, p. 525. The 

analyses show large admixtures of titanic oxide in the bauxite.

6 Geol. Survey Georgia, The Palaeozoic group, 1893, p. 214. 

0 Geol. Survey Alabama, pt. 2,1S97.

7 Sixteenth Ann. Rept. U. S. Geol. Survey, pt. 3,1895, p. 547. See also Trans. Am. Inst. Min. Eng., 

1894,p. 243.

8 Bull. No. 11, Geol. Survey Georgia, 1904.

" Zeitschr. prakt. Geologic, 1897, p. 212.

Jo Trans. Am. Inst. Min. Eng., vol. 24,1894, p. 573.
474 THE DATA OF GEOCHEMISTBY.

described by W. Cross; 1 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. 2 The latter 

species, it may be observed, was prepared synthetically by A. De 

Schulten,3 by passing a current of carbon dioxide through a hot alkaline solution of aluminum hydroxide. Distinct crystals of gibbsite 

were thus obtained.

The bauxite of Arkansas has been studied by J. F. WillianiSj4 J. C. 

Branner, 5 and C. W. Hayes.6 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 elaeolite syenite. Both 

gibbsite and diaspore are known as decomposition products of elaeolite and sodalite,7 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. 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 .H2 0, and gibbsite, A1203 .3H2 0; but is sometimes

1 Seventeenth Ann. Rept. 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. Ransome, Econ. Geol., vol. 2,1907, p. 

673. Ransome also reports intergrowths of alunite and diaspore.

s See W. B. Phillips and D. Hancock, Jour. Am. Chem. Soc., vol. 20,1898, p. 209. Admixtures of kaolin, 

halloysite, and sand were noted. See also Watson's bulletin, loc. cit., and A. E. Hunt, Trans. Am. Inst. 

Min. Eng., vol. 24,1894, p. 855. Titanic oxide is almost invariably present, in some cases reaching as high 

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.

» Bull. Soc. min., vol. 19,1896, p. 157.

4 Ann. Rept. Geol. Survey Arkansas, vol. 2,1890, p. 124. '

6 Jour. Geology, vol. 5,1897, p. 263. This review contains a bibliography of bauxite, and references to 

earlier papers by Branner.

" Twenty-first Ann. Rept. U. S. Geol. Survey, pt. 3,1901, p. 435.

* See S. J. Thugutt, Neues Jahrb., Beil. Bd. 9,1895, p. 609. Also W. C. Brogger, Zeitschr. Kryst. Min., 

vol. 16,1890, p. 50.
THE DECOMPOSITION OF BOOKS. 475

near one and sometimes near the other. It seems, in fact, to be a 

mixture of the two hydrates, but in an amorphous condition. 1 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. 2 The ordinary, precipitated, gelatinous hydroxide has the same composition, according to E. T. 

Alien; 3 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 

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 4 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. Although rare as a recognizable substance, it 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,5 on comparing French soils with 

soils from Madagascar, found the latter to contain much free alumina, while in France1 there appeared to be chiefly, if not exclusively, 

silicates. Similar observations were made by J. M. van Bemmelen 6 

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 7 leads to the same conclusions. In these cases the 

bauxite or laterite substance is diffused instead of being concentrated.

1 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 TiOa reaches 12.21 

per cent.

2 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.

»Chem. News, vol. 82,1900, p. 75. On this subject there is a voluminous literature, and the published 

data are very discordant.

4 Rec. trav. chim., vol. 7,1888, p. 75. Zeitschr. anorg. Chemie, vol. 18,1898, p. 132.

» Compt. Rend., vol. 132, 1901, 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.

»Zeitschr. anorg. Chemie, vol. 42,1904, p. 265.

' Lavas and soils of the Hawaiian Islands.
476 THE DATA OF GEOCHEMISTRY.

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 impurities 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.

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

1 Annales chim. phys., 3d ser., vol. 61, 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. Riley, Jour. Chem. Soc., vol. 15,1862, p. 311, and vol. 16,1863, 

p. 387. See also F. Pi Dunnington, Am. Jour. Sci., 3d ser., vol. 42,1891, p. 491.

2 Zeitschr. Deutsch. geol. Gesell., vol. 56, Monatsb., 1904, p. 17.
THE DECOMPOSITION OF BOCKS. 477

formation. Possibly lialloysite, which has the composition of 

kaolinite plus water, but which is decomposed by acids, is such an 

intermediate compound. The association of lialloysite 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 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 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 will 

take up potash more readily than lime, magnesia, or soda, and retain 

it tenaciously. This absorption 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, and preferably the former, were especially 

active as absorbents, and most so in presence of calcium carbonate. 

That is, the last-named compound converted,other alkaline salts into 

carbonates, which were more easily absorbed. J. Lemberg's papers 5 

upon 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.

1 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, and 1911, p. 197, in the cases of allophane, halloysite, and montmorillonite. 

Their deflniteness as compounds, on the other hand, is affirmed by S. J. Thugutt, idem, 1911, p. 97. Several of these minerals have been studied physically by E. Lowenstein, Zeitschr. anorg. Chemie, vol. 63, 

1909, p. 69, whose experiments are favorable to their integrity.

2 See A. Liebrich, Zeitschr. prakt. Geologie, 1895, p. 275.

«Jour. Eoy. Agr. Soc. England, vol. 11, 1850, p. 313; vol. 13, 1852, p. 123.

«Jour. Chem. Soc., vol. 21,1868, p.. 1.

s See especially the memoir in Zeitschr. Deutsch. geol. Gesell., vol. 28, 1876, p. 519.

« Mitth. Or. Badisch. 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. Bad. 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. Do.pt. 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.
478 THE DATA OF GEOCHEMISTRY.

Double decomposition, however, is not the only process to be considered in this connection. Warington's experiments .point directly 

to an absorption by colloids, namely, the colloidal hydroxides of iron 

and alumina. According to J. M. van Bemmelen/ 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 

streams, by glacial ice, or by winds and it is accompanied to a certain 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 composed 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

1 Zeitschr. anorg. Chemie, vol. 23,1900, p. 321. See especially pp. 358 and 364. An earlier paper by Van 

Bemmelen in Landw. Versuchs-Stationen (Berlin), vol. 21, p. 135, should also be noted.

2 Zeitschr. anorg. Chemie, vol. 42,1904, p. 314.

3 Chimie agricole, in Fremy's Encyclopedic chimique, p. 67.

< Zeitschr. anorg. Chemie, vol. 41,1904, 325.

s 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.

o See also F. E. Grout, Jour. Am. Chem. Soc., vol. 27, 1905, p. 1037. Grout admits that colloids may 

assist in producing plasticity, but thinks that "molecular attraction" is a more important cause. A paper 

by R. Lucas on the physical properties of clays appeared in Centralbl. Min., Geol. u. Pal., 1906, p. 33.
THE DECOMPOSITION OF KOCKS. 479

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; hence 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 sands 

of many well-known localities represent concentrations of heavy and 

slightly alterable minerals, such as magnetite, ilmenite, chromite, 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, chromite, 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, chromite, garnet, olivine, amphibole, pyroxenes, calcium carbonate, sodium and potassium chlorides, and clay. In a glacial sand 

from the Tyrol, H. Wichmann 4 discovered quartz, orthoclase, micas, 

chlorite, epidote, hornblende, actinolite, 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. 36,1887, p. 91. 

»Bull. Soc. mln., vol. 1,1878, p. 39. 

»Idem, vol. 4,1881, p. 262.

< Mln. pet. Mitt., vol. 7,1886, 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. 

5 Quart. Jour. Geol. Soc., vol. 38,1882, p. 110.
480 THE DATA OP GEOCHEMISTBY.

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 1 on 

the dune sands of Holland. In these the principal minerals are quartz, 

garnet, augite, .hornblende, tourmaline, epidote, staurolite, rutile, 

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, 

Florida, analyzed by G. Steiger in the laboratory of the United States 

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 subsilicic igneous rocks. 

F. Blown sand.

SiOa .........................

A12 03 ........................

FeA.... ....................

FeO..........................

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

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

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

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

Na2 0........................

P 0

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

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

. .46

.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

fl 44

oq

.16

4- 1«0 |-»/}

i'Tor'O

1 1Q

.70

.65

100. 42

SILT.

Between sand and silt the difference is partly one of land 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

' i Neues Jahrb., 1896, vol. 1, p. 16; Rec. trav. cMm., vol. 11,1892, p. 169.

a Trans. Edinburgh Geol. Soc., vol. 8,1901, p. 60. On the mineralogical examination of sands see also 

C. H. Warren, Technology Quart., vol. 19, 1906, p. 317. For analyses of American glass sands see Bull. 

TJ. 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. 

Failyer, J. 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.
THE DECOMPOSITION OF KOCKS. 481

and silt differ in composition, but not radically. In sand quartz is 

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 t 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 

chemischen und physikalischen Geologie, 2d ed., vol. 1, p. 498. Bischof gives other data also concerning 

Rhino deposits.

B. Danube silt, at Vienna. Analysis by Bischof, 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, 1896, p. 259. See also 

analyses cited by G. Bischof, op. cit., pp. 518-521; and others cited by L. Horner, in two memoirs Phil. 

Mag., 4th ser., vol. 9, 1855, p. 469; Phil. Trans., vol. 148, 1859, p. 61. In Science, vol. 23, 1906, p. 364, 

there is an incomplete analysis by C. H. Stone of Mississippi silt. For modern analyses of silt from the 

Danube and its tributaries see J. F. Wolfbauer, Monatsh. Chemie, vol. 4,1884,-p. 417, and A. Schwager, 

Geognost. Jahreshefte, 1893, p. 87. F. Schucht (Jahrb. K. preuss. geol. Landesanstalt, vol. 25, p. 442) cites 

analyses of Elbe silt by H. Siissenguth.

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

Al O

FeaOg.. ..............................:.....-...

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

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

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

K.O........ ...................................

N&fi. ........................................

CaC03 ........................................

MgC03 .................................. .......

FeC03 . ........................................

cr» i&--:::::::.-.::::::::::::::::::::::::::::::::

3,0+.........................................

Organic matter. . ...............................

Loss. ..........................................

A

50.14

4.77

2.69

.35

.34

.77

.55

.54

30.76

1.24

5.20

} .99

1.66

100. 00

B

45.02

7.83

9.16

.44

.32

(?)

(?)

24.08

6.32

} 4.58

&2. 25

100. 00

C

49.67

11.98

11.73

.27

.88

1.29

.69

23.21

99.72

D

45.10

15.95

13.25

o fM

4.85

1.95

.85

 34

6.70

« 8. 84

100. 47

a Loss on ignition. 

101381° Bull. 491 11 31

& Probably including alkalies.
482 THE DATA OF GEOCHEMISTRY. ,

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 Nile mud is a much more typical 

product.

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 1 at approximately 812,500,000,000 pounds, or about 

370,000,000 metric tons. The Nile, according to A. Chelu,2 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. 3 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 explanation of the 

phenomenon is still obscure. 4 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 5 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 flocculent precipitate which 

quickly subsides and carries down with it, mechanically inclosed, 

even the finest sediments. The remarkable clearness of 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 assist 

hi bringing it about.

1 Report on physics and hydraulics of Mississippi River, 1876, p. 148.

2 Le Nil, le Soudan, 1'Egypte, 1891, p. 177.

3 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.

< See C. Schlosing, Compt. Rend., vol. 70,1870, p. 1345; W. H. Brewer, Am. Jour. Sci., 3d ser., vol. 29,1885, 

p. 1; C. Barus, Bull. U. S. Geol. Survey No,36,1886; Barusand E. A. Schneider, Zeitschr. physikal. Chemie, 

vol. 8,1891, p. 285; W. Spring, Rec". trav. chim., vol. 19, 1900, p. 204; and G. Bodliinder, Neues Jahrb., 

1903, pt. 2, p. 147. See also T. S. Hunt, Proc. Boston Soc. Nat. Hist., vol. 16,1874, p. 302; W. Ramsay, 

Quart. Jour. 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, 8th ser., 

vol. 19,1891, p. 5.

5 Bull. Acad. Belgique, 3d ser., vol. 34,1897, p. 578.
THE DECOMPOSITION OF BOCKS. 483

GLACIAL 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 1 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, made by 

Kiggs in the laboratory of the United States Geological Survey, and 

cited by Chamberlin and Salisbury in the memoir mentioned above. 

With them I give two analyses by W. Mackie 2 of bowlder clay from

Scottish localities.

Analyses of clays.

(1) Residuary clays, dried at 100°:

A. From Dodgeville, Wisconsin, 4J feet below surface. 

B. The same, 8J feet below surface. 

C. From Cobb, Wisconsin, 4$ feet below surface. 

D. The same, 84 feet below surface.

(2) Glacial or drift clays:

E, F. From Milwaukee. Dried at 100°. 

G, H. Scottish bowlder clays, Mackie.

SiOa ..................

AljOg.. ...............

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

FpO

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

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

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

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

H20..... ..............

TiOa ..................

P 0

Mn<5... ........ .......

C02 ........... ........

S03 . .................

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

A

71.13

12.50

5.52

.45

.38

.85

2.19

1.61

4.63

.45

.02

.04

.43

.19

100. 39

B

49.59

18. 64

17.19

.27

.73

.93

.80

.93

10. 46

.28

.03

.01

.30

.34

100. 50

C

49.13

20.08

11.04

.93

1.92

1.22

1.33

1.60

11.72

.13

.04

.06

.39

1.09

100. 68

D

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

trace

18.76

.32

.13

.06

100. 27

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

G

80. 13

9.06

| 2.44

.50

.72

.66

2.08

« 4. 11

.14

99.84

H

74.89

12.22

} 4.29

.07

1.58

1.06

2.64

«3.21

.07

.17

100. 20

« Loss on ignition. Must include GOa and organic matter.

In the two Wisconsin clays the carbonates represent magnesian 

limestone. The Scottish clays had evidently a different parentage. 

Glacial clays often contain carbonates, which are rarely conspicuous

1 Sixth Ann. Kept. U. S. Geol. Survey, 1885, pp. 249-250. 

s Trans. Edinburgh Geol. Soc., vol. 8, 1901, p. 60.
484 THE DATA OF GEOCHEMISTRY.

in rock residues.1 Even residual soils derived from the decay of 

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 days.

A. Residual clay from so-called Trenton limestone, Lexington, Virginia. Analysis by R. B. Rlggs. 

Described by I. C. Russell, Bull. U. S. Geol. Survey No. 52,1889. Russell especially discusses the cause of 

red coloration in clays. On this subject see also W. O. Crosby, Am. Geologist, vol. 8,1891, 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. Hillebrand. Described 

by Russell, op. cit.

Si02 .......................... :......................

A1 O

YezO................. .................................

FeO..................... ..............................

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

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

Na20.................................................

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

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

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

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

P O

C02 ............... ....................................

A

43.07

25.07

15.16

.03

.63

1 90

2.50

} 12. 98

100. 64

B

55.90

19.92

7.30

.39

1.18

.50

.23

4 7Q

9 ^4

6.52

.20

.10

.38

99.95

C

55.42

22.17

8.30

1.45

.15

.17

2.32

2.10

7.76

99.84

1 Innumerable analyses of clays and soils have been made for agricultural and other industrial purposes. 

Several States have issued special reports upon their clay industries. Among the reports of geological 

surveys are those of Connecticut, Bull. No. 4, 1905, G. F. Loughlin; New Jersey, 1878, G. H. Cook; New 

Jersey, vol. 6, 1904, H. Ries and H. B. Kummel; Maryland, vol. 4, pp. 203-503, Ries; Virginia, Bull. No. 

11,1906, Ries; West Virginia, vol. 3, 1905, G. P. Grimsley; South Carolina, Bull. No. 1, 4th ser., 1904, E. 

Sloan; Georgia, Bull. No. 6 A, 1898, G. E. Ladd; Alabama, Bull. No. 15,1900, Ries; Wisconsin, Bull. No. 7,

1901, E. R. Buckley; Missouri, vol. 11, 1896, H. 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. U. S. Geol. Survey No. 228, 

pp. 351-370. Ries, Sixteenth Ann. Rept. U. S. Geol. Survey, 1895, pp. 554-574, gives a long table of analyses 

of American clays, and a general report by Ries forms Prof. Paper 11 of the Survey, 1903. Bull. U. S. 

Geol. Survey No. 143, 1896, 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 material on soils, and so, too, do the volumes on cotton production published by the Tenth U. S. Census. The literature regarding soils is too voluminous to admit 

of any summary here. Recent papers of interest are those by N. Sibirtzew, Compt. rend. VII. Gong, 

internat. 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 Schlosing and Van Bemmelen on tropical soils has already been cited. 

W. Maxwell (Lavas and soils of the Hawaiian Islands, Honolulu, 1898) and A. B. Lyons (Am. Jour. Sci., 

4th ser., vol. 2, 1896, p. 421) have also contributed to this phase of the subject. On the constitution of 

arable soils see L. Cayeux, Ann. Soc. geol. du Nord, vol. 34,1905, p. 146. On the origin and nature of soils 

see N. S. Shaler, Twelfth Ann. Rept. U. S. Geol. Survey, pt. 1,189i, 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," published in 1906.
THE DECOMPOSITION .OF BOOKS. 485 

LOESS.

In its chemical compostion, the widespread earthy deposit known 

as loess closely resembles the glacial clays. It 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. Kichthofen, 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 

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,2 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,3 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 4 as a glacial silt, 

deposited along the margins of glaciers during the glacial period. 

W. F. Hume,5 studying the Russian loess, described that also as

1 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. Schwager, 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. Other analyses of loess are to be found in the older treatises of 

Bischof and Roth.

2 Geol. Mag., 1889, pp. 289, 342.

s Am. Jour. Sci., 4th ser., vol. 6,1898, p. 299. Keyes describes the dust storms of the Missouri Valley, 

In which great quantities of aerial sediments are carried from place to place.

«Eleventh Ann. Rept. U. S. Geol. Survey, pt. 1,1891, pp. 291, 435. See also F. Leverett, 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. Emmons in Mon. U. S. Geol. Survey, vol. 27,1890, p. 263.

s Geol. Mag., 1892, p. 549.
486 THE DATA OF GEOCHEMISTRY.

glacial silt, distributed partly by winds and partly by floods. C. 

Davison* 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 2 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 may 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,3 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. Chemical analyses of loess seem not to be 

very numerous. The following were made in the laboratory of the 

United States Geological Survey:

Analyses of loess.

A. Near Galena, Illinois.

B. Near Dubuque, 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. Oeol. Survey, 1885, p. 282. Samples dried at 100°.

E. Cheyenne, Wyoming.

F. Denver, Colorado.

G. Highland, Colorado. Analyses E to G by L. G. Eakins. Discussed by S. F. Emmons, Mon. U. S. 

Geol. Survey, vol. 27,1896, p. 263, together with several other examples.

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

A1203 ................ it 0 '

FeA. ...............

FeO ................

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

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

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

Na20 ................

K2 0. .................

H20. .................

TiO

p o

C0a ......... .........

C, organic ............

S08 ...................

01....................

A

64.61

10.64

2.61

.51

.05

3.69

5.41

1.35

2.06

2.05

.40

.06

6.31

.13

.11

.07

100. 06

B

72.68

12.03

3.53

.96

.06

1.11

1.59

1.68

2.13

2.50

.72

.23

.39

.09

.51

.01

100. 22

C

60.69

7.95

2.61

.67

.12

4.56

8.96

1.17

1.08

1.14

.52

.13

9.63

.19

.12

.08

99:62

D

74.46

12.26

3.25

.12

.02

1.12

1.69

1.43

1.83

2.70

.14

.09

.49

.12

.06

.05

99.83

E

67.10

10.26

2.52

.31

1.24

5.88

1.42

2.68

5.09

.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. 40

G

60.97

15.67

5.22

.35

trace

1.60

2.77

.97

2.28

9.83

.19

.31

100. 16

1 Quart. Jour. Geol. Soc., vol. 50,1894, p. 472.

2 Jour. Geology, vol. 5,1897, p. 795. See also T. C. Chamberlin and R. D. Salisbury, Sixth Ann. Rept. 

U. S. Geol. Survey, 1885, p. 250. 

s Bull. U. S. Geol. Survey No. 150,1898, p. 65.
THE DECOMPOSITION OF BOOKS. 487

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 Lake City, Utah. B. Santa Fe,New Mexico. C. Fort Wingate, New Mexico. D. Humboldt, 

Nevada.

SiO,.. ........................................

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

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

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

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

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

Na20.........................................

K26. ........................................

H20. ........................................

P O &,r;::::::::::::::::::::::::::::::::::::::::

Organic matter . . . ............................

QH

01 ...........................................

A

19.24

3.26

1.09

trace

2.75

38.94

trace

trace

1.67

.23

29.57

2.96

.53

.11

100. 35

B

66.69

14.16

4.38

.09

1.28

2.49

.67

1.21

4.94

.29

.77

2.00

.41

.34

99. 72'

C

26.67

.91

.64

trace

.51

36.40

trace

trace

2.26

.75

25.84

5.10

.82

.07

99.97

D

44.64

13.19

5.12

.13

2.96

13.91

.59

1.71

3.89

.94

8.55

3.43

.64'14

99.84

The extremely variable but generally calcareous nature of these 

soils is sufficiently indicated.

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

1 Seep. 118, ante.

2 See 3. Murray and A. Renard, Proc. Roy. Soc. Edinburgh, vol. 12,1883-84, p. 474.
488 THE DATA OF GEOCHEMISTRY.

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, 1 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 deposits," Murray and 

Renard 2 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.

Mean depth and area covered by marine sediments.

Littoral deposits (between tide marks) ....................

Shallow-water deposits (low water to 10 

Terrigenous deposits, near land ........<

Pelagic deposits, deep water, far from

0 fathoms)....... . .

Volcanic mud..... 

Volcanic sand..... 

Green mud .......

Green sand........

Red mud..........

Blue mud.........

'Pteropod ooze.... . 

Globigerina ooze. . 

Diatom ooze......

Radiolarian ooze. .

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, 000 

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 ejectamenta. 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 was discussed 

in a former chapter 3 of this work, together with the composition of 

the peculiar manganese and phosphatic nodules which ar.e often 

found in great numbers in the deeper parts of the sea.

' R. Pumpelly, Am. Jour. Sci., 3d ser., vol. 17,1879, p. 133. 

2 Challenger Rept., Deep-sea deposits, 1891, table on p. 248. 

»Chapter IV, p. 120, ante.
THE DECOMPOSITION OF KOCKS. 489

Analyses of marine sediments.

A. Red clay. Twenty-three analyses by J. S. Brazier are tabulated on page 198, 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 ooze. 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.

All samples dried at 110° previous to analysis. The soluble and insoluble portions in analyses A, B, and 

D are not separated in the following table.

See also J. B. Harrison and A. J. Jukes Brown, Quart. Jour. Geol. Soc., vol. 51, 1895, p. 313, for other 

analyses of red clay and oceanic oozes. For 14 recent analyses of red clay, see W. A. Caspari, Proc. Roy. 

Soc. Edinburgh, vol. 30,1910, p. 183. "

Ignition...................... siOa .........................

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

FejOa-. ......................

Mn02 ............... ..........

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

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

CaC03 .........................

Ca3P208 -----------. --- -------

CaS04 ................ ........

MgCOg.. .....................

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 

.39 

.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.

G. Blue mud. Analysis by J. S. 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. 

K. Volcanic mud. Analysis by Brazier, page 450.

Analyses G to K represent "terrigenous "deposits. Brazier's samples were all dried atllO". Thesoluble 

and insoluble portions are here united.

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

Al O

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

MnOa .................................

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

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

NajQ........................... .......

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

CaC03 ... ......... .."............ .......

Ca3P208 . ...............................

CaS04 .. ............................... Mgco3 ... ..................:...........

so3 ...................................

coa ........... .......................

01....................................

LessO=Cl......................

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

1.07

2.02

100. 00

K

6.22

34.12

9.22

15.46

1.44

.22

32.22

trace

.27

.83

100. 00
490 THE DATA OF GEOCHEMISTKY.

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.

Analyses of composite samples of marine sediments.

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 "green muds" and forty-eight 

"blue muds." Analysis by G. Steiger.

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

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

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

rv n

FeA.. ............ .........................................

FeO................. ......................../..............

NiO.CoO.. ................................................

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

Mn02 .. .....................................................

MgO.. ...:.........................'........................

CaO ............................ . , .........................

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

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

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

NaaO.. ....................................................

V2 03 - .....................................................

Mo03 . ......................................................

P O

s^.:.v.v;:::::::::::::::::::::::::::::::::::::::::::::::

CuO ....................................................... Pbo....:...................................................

ZnO.. .....................................................

C................... .......................................

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

A

54.48

.98

15.94

.012

8.66

.84

.039

1.21

3.31

1.96

.056

.20

2.85

2.05

.035

..001

.30

.024

.008

.005

7.04

100. 000

B

57.09

1.27

17.24

.05

5.07

2.30

.12

2.17

2.04

.03

.06

2.25

1.05

.03

.21

.13

.02

undet

1.69

7.18

100. 00

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 ocean-
THE DECOMPOSITION OF BOCKS. 491

ography.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 

reduction red sediments are formed; if the reducing process preponderates, the sediments are blue. In the Black Sea, according to N. 

Androussow,3 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 K.. Irvine 4 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 algse 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. 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 their 

formation can be imitated artificially. A. H. Church,5 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.

1 See, for example, K. Natterer, on Mediterranean muds, Monatsh. Chemle, 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-Nordhavs 

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) described 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).

2 Proc. Roy. Soc. Edinburgh, vol. 18,1890-91, p. 17.

8 Guide des excursions du VII Gong, gfiol. internal., No. 29,1897, p. 6.

* Proc. Roy. Soc. Edinburgh, vol. 18,1890-91, p. 229.

6 Jour. Chem. Soc., vol. 15,1862, p. 109.
492 THE DATA OF GEOCHEMISTRY.

GLAUCONITE.

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 

exceedingly 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 Kenard,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 coUoidal 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

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.

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. Akad. 

Miinchen, vol. 16, 1886, p. 417; vol. 26. 1896, p. 545. Also D. S. Calderon, D.'F. Chaves, and P. del Pulgar, 

An. Soc. espafi. hist, nat., vol. 23,1894, p. 8. The older literature of the subject is unimportant for present 

purposes.

3 Contributions a P6tude micrographique des terrains sedimentaires: M6m. Soc. ge"ol. du Nord, vol. 4, 

pt. 2, 1897, pp. 163-184.
THE DECOMPOSITION OF BOOKS. 493

The granules of glauconite from marine mud and from the sedimentaiy rocks, although not found as definite crystals, have nevertheless a distinct cleavage, and are interpreted by A. Lacroix 1 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, 

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'"KSi2O8 .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

' MinSralogie de la France, vol. 1, 1893-1895, p. 407. Lacroix gives a number of analyses of French and 

Belgian glauconites.

2 Sitzungsb. Akad. Miinchen, vol. 20,1890, p. 545.

aZeitschr. 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. Eend., vol. 142, 1906, p. 999. The authors give an analysis of very pure marine 

glauconite. Two other analyses are given by W. A. Caspari, Proc. Roy. Soc. Edinburgh, vol. 30, 1910, p. 

364. Caspari also describes the synthesis of a compound resembling glauconite. An important monograph 

by Collet, Les d§p6ts marins, was published at Paris in 1908.

6 Many analyses of greensand marls are given by G. H. Cook, in Geology of New Jersey, 1868, pp. 414 et 

seq. OnNew Jersey greensands see also W. B. Clark, Jour. Geol., vol. 2,1894, p. 161. On Irish glauconite, 

see A. J. Hoskins, Geol. Mag., 1895, p. 317.
494 THE DATA OF GEOCHEMISTRY.

Analyses of glauconite and celadonite.

A. Glauconite, from Woodburn, Antrim, Ireland. Analysis by A. P. Hoskins, Geol. Mag., 1895, p. 320.

B. Glauconite from Cretaceous sandstone, Padi, Government Saratoff, Russia. 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. Baskerville, Am. Chem. Jour., vol. 14, 1892, p. 027. 8.22 per cent of the silica is stated separately as quartz.

D. Oceanic glauconite, mean of four analyses made by L. Sipocz for Murray and Renard, Challenger 

Rept., 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. 26,1896, p. 545.

F. Celadonite, Monte Baldo, near Verona, Italy. Analysis by Schwager. See Q umbel, 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 .................

A1203 -- ..............

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

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

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

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

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

Na20..................

K^O.. ................

Li20.................

HaO.------ -----------

TiO

P O

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

9.56

21.46

1.58

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

} 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

trace

.24

.07

100.47

G

54.84

3.52

12.64

4.90

.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 1 that glauconite is frequently present in 

arable soils, in all conditions from perfect freshness to complete 

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.

' Annales Soc. ge"ol. du Nord, vol. 34,1905, p. 146.
THE DECOMPOSITION OF BOCKS. 495

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 1 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.

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, arid since natural 

waters differ in composition the solvent .process is necessarily variable. 

Cameron and Hurst, 7 who studied the solution of iron, aluminum, 

and .calcium phosphate, showed that the process is one of hydrolysis, 

the solution becoming acid,8 and less soluble basic phosphates being

1 See p. 337, and also the analyses of igneous rocks given in Chapter XI.

3 For goodsummaries relative to theoccurrenceofeconomicallyimportantphosphatesoflime,seeR. A. F. 

Penrose, Bull. U. S. Geol. Survey No. 46,1888; A. Carnot, Annales des mines, 9th ser., vol. 10, 1896, 

p. 137; and E. Nivoit, in Fremy's Encyclopedic chirnique, vol. 5, sec. 1, pt. 2,1884, p. 83. All these memoirs contain numerous analyses, and Penrose gives a bibliography of the subject down to 1888.

» See F. K. Cameron and L. A. Hurst, Jour. Am. Chem. 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. Schlosing 

(Compt. 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. 454.

6 Jour. Chem. Soc., vol. 78, pt. 2,1900, p. 618. Abstract.

8 Am. Jour. Sci., 3d ser., vol. 43,1892, p. 402.

i Loc. cit.

8 Apatite gives alkaline reactions. F. K. Cameron and A. Seidell, Jour. Am. Chem. Soc., vol. 27, 1905, 

p. 1510.
496 THE DATA OF GEOCHEMISTBY.

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,1 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, Fe3P208 .8H20, for example, is not uncommon in clays; it is found lining belemnites and other fossils at Mullica Hill, New Jersey; and near Edgeville, Kentucky, W. L. Dudley 2 

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, turquois, callainite, peganite, sphaerite, evansite, 

wardite, and zepharovichite. Most of these minerals are rare 

species, found in very few localities, and need no further consideration 

here.3 Wavellite, however, has been mined near Mount Holly 

Springs, Pennsylvania, and used as a source of phosphoric acid.4

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 may be 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.5 The following compounds are the best 

known among them:

Monetite................................... HCaP04 .

Brushite...................................HCaP04 .2H20.

Metabrushite...............................2HCaP04 .3H20.

Martinite.................................2H2Ca5(P04 )4 .H20.

Collophanite............................... Ca3P208 .H20.

Bobierrite................................Mg2P208 .8H20.

Newberyite.............................. .HMgP04 .3H20.

Hannayite................................Mg3P208 .2H2NH4P04 .8E2O.

Stmvite................................. .NH4MgP04 .6H20.

Stercorite................................. .HNaNH4P04 .4H2 0.

1 Jour. Chem. Soc., vol. 19,1866, p. 296.

2 Am. Jour. Sci., 3d ser., vol. 40,1890, p. 120.

3 For details concerning these minerals, see Dana's System of mineralogy and its 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.

6 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 BOCKS. 497

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 sometimes present in 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-Conn6 table, 

near the coast of French Guiana. All of these represent changes 

brought about by percolations from bird guano.

In the Minerva grotto, department of FH6rault, France, A. Gautier 6 found brushite, tribasic calcium phosphate, and a phosphate 

of aluminum to which he gave the name minervite. To this he 

assigned the formula A12P2 08 .7H2 0, but his data seem to have been 

based on impure material. A later analysis by A. Carnot 7 gives the 

mineral a very different composition. In the same memoir Carnot 

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

l For the Navassa phosphate, see E. V. d'lnvilliers, Bull. Geol. Soc. America, vol. 2,1891, p. 75. W. B. 

M. Davidson (Trans. Am. Inst. Min. Eng., vol. 21,1892-93, p. 139), thinks it may be a residual concentration from phosphatic limestone and not a guano product. For Sombrero, see A. A. Julien, Am. Jour. Sci., 

2d ser., vol. 36,1863, 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 the 

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 phosphate see G. Hughes, Quart. Jour. Geol. Soc., vol. 41,1885, p. 80.

2 Quart. Jour. Geol. Soc., vol. 54,1898, p. 230.

3 Bull. Soc. min., 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.

6 Compt. Rend., vol. 119,1894, p. 1011.

« Annales des mines, 9th ser., vol. 5,1894, p. 1. Compt. Rend., vol. 116,1893, pp. 928,1023. .

i Annales des mines, 9th ser., vol. 8,1895, p. 319. Compt. Rend., vol. 121,1895, p. 152.

101381° Bull. 491 11 32
498 THE DATA OF GEOCHEMISTRY.

true of a white, pulverulent substance described by J. C. H. Mingaye 1 

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, Teall.

B. Martinique, analysis by Arsandaux.

C. Redonda, Shepard.

D. Grand-Conne'table, Andouard.

E. Minerva Grotto, Carnot. 

F. Oran, Carnot. 

. G. Jenolan caves, Mingaye. 

H. Controne, Sicily, Casoria.

P205 ......... .........

Al O

Fe£>9 ... ..............

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

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

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

Na20.................

NH8 ......... .........

F.. 3 .. ...............

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

BO,.. ................

C02 ....... ............

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

Insoluble..............

H20, 100°.............

H20, 180°.............

H20, 200°.............

H20, ignition. .........

A

38.5

25.9

7.4

1 5.0

23.0

99.8

B

41.20

34.20

24.50

99.90

C

43.20

14.40

16.60

.57

1.60

100. 37

D

39.10

25.59

8.03

1.40

trace

.06

1.70

621. 24

2.50

99.62

E

37.. 28

18.59

.83

.33

1.40

'8.28

.52

trace

trace

trace

} 4.35

23. 70

4.50

99.78

F

35.17

18.18

.31

5.80

.48

trace

trace

trace

11.60

13.40

14.80

99.74

G

40.83

20.70

.20

trace

trace

9.01

i. i2

99.55

Ho

37.10

22.89

1.17

8.04

.02

.61

.36

7.87

c21. 29

99.35

a This substance, named palmerite by E. Casoria (Zeitschr. Kryst. Min., vol. 42, 1906, 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 to minervite.

6 At 105°.

c Loss on ignition. ,

Although these analyses do not represent pure compounds, they 

yield approximations to simple formulae. A, B, and D are not far

from variscite, A1PO4 .2H2O. C suggests the analogous barrandite, 

(AlFe)P04 .2H20. Minervite, especially as shown in Mingaye's analysis, probably contains a salt of the composition H2KA12 (PO4 ) 3 .6H2 0. 

To establish any of these formulae, however, would require much 

more careful investigation than has hitherto been practicable and 

upon more homogeneous material.

The phosphates of the Minerva grotto, according to Gautier,2 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 minervite, and 

even a clay was altered by the reagent. Siderite, FeC03 , similarly

1 Rec. Geol. Survey New 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. Cooke 

in Trans. Roy. Soc. South Australia, vol. 31,1907, p. 65.

> Annales des mines, 9th ser., vol. 5,1894, p. 1. Compt. Rend., vol. 116,1893, pp. 928,1023,
THE DECOMPOSITION OF BOOKS. 499

treated with ammonium phosphate, was converted into a salt of the 

composition Fe3 (P04 ) 2 .6H20; 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.1 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, 

Ca5 (P04 )3F; but some varieties are more nearly the normal tricalcium phosphate, Ca3 (POJ 2 . According to A. Carnot,2 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 3 identifies collophanite, dahllite (Ca6 (P04)4. 

CaC03 .£H20) and francolite, which also contains calcium carbonate. 

To the phosphorite 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 4 assigned the formula 4Ca0.2P2O5 .Si02 , 

regarding the substance as a definite mineral species to which he 

gave the name ciplyte. In an Algerian phosphate, G. Schuler 5 found 

chromium, to an average amount of 0.057 per cent of Cr2O3 . Oxides 

of iron, alumina, magnesia, calcium carbonate, gypsum, silica, 

sand, and clay are common impurities. Nitrogenous organic matter 

is also often present. Some so-called phosphate rocks are merely 

phosphatized limestones, sandstones, or shales. In certain Cretaceous sandstones of Russia, calcium phosphate occurs as a cement 

for the sand grains and also in the form of fossil bones and fossil 

wood. The wood has been completely replaced by phosphate.6 

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,

1 Even the highly crystallized Canadian apatites of the Grenville series are regarded by W. H. McNairn 

as originally marine deposits which have undergone metamorphisni. Trans. Canadian Inst., vol. 8, p. 495.

2 Compt. Rend., vol. 114,1892, p. 1003.

3 Idem, vol. 150,1910, pp. 1213,1388. See also his Mineralogie de la France, vol. 4, pp. 555-586. 

«Annales Soc. geol. du Nord, vol. 16,1888-89, p. 270. 

6 Zeitschr. angew. Chemie, 1898, p. 1101.

 See a table of 18 analyses by A. Engelhardt, Claus. P. Latschinow, and P. Kostychew in Revue da 

geologic, vol. 7,1867-68, p. 320. The wood, bone, and cement have practically the same composition.
500 THE DATA OF GEOCHEMISTRY.

as A. Carnot 1 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 in 

phosphorites, but the presence of bromine is more doubtful.2

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.3 Some phosphate 

is also dissolved, but it is in part redeposited around nuclei, such as 

shells or fragments of bone, forming the phosphatic nodules which 

are so often found upon the ocean floor.4 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 5 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 

the richest; crustacean remains probably come next; mollusks and 

corals are the poorest. As a rule, molluscan shells and corals consist 

mainly of calcium carbonate, but some species are highly phosphatic. 

In a recent lingula, for instance, W. E. Logan and T. S. Hunt 6 

found 85.79 per cent of calcium phosphate. The fossil casts of a gasteropod, Cyclora, are also, according to A. M. Miller, 7 rich in phos1 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.

2 See F. Kuhlmann, Compt. Rend., vol. 75,1872, p. 1678.

s See discussion by L. Kruft, Neues Jahrb., Beil. Bd. 15,1902, p. 1. This memoir relates to the distribution of phosphorite in the older Paleozoic formations of Europe.

«See J. Murray and A. F. Renard, Challenger Rept., Deep-sea deposits. 1891, pp. 397-400. Also ante, 

in Chapter IV, p. 123.

& Bull. Acad. Belgique, vol. 21,1891, p. 126.

e Am. Jour. Sci., 2d ser., vol. 17,1854, p. 236.

' Am. Geologist, vol. 17,1896, p. 74.
THE DECOMPOSITION OF EOCKS. 501

phate. The Cambrian phosphates of Wales are regarded by H. 

Hicks * as derived in large part from crustaceans, a supposition which 

is borne out by W. H. Hudleston's analyses.2 The shell of a giant 

trilobite contained 17.05 per cent of P205 ; 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.

The deposits thus formed by animal remains, upon the bottom of 

the sea, are at best but moderately phosphatic. 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 residuary deposit, more or less impure, and varying much in

richness. The beds near Mons, in Belgium, according to F. L. 

Cornet,3 were thus derived from phosphatic chalk, from which the 

calcareous shells have disappeared, while the flints, siliceous sponges, 

and vertebrate bones are unchanged. According to Chateau 4 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,5 to account for the nodular phosphates of South Carolina, 

and it seems to apply equally well to the other phosphorite deposits 

of the United States.

The phosphorites of Tennessee, which have been somewhat exhaustively studied,6 furnish an excellent illustration of the several

1 Quart. Jour. Geol. Soc., vol. 31,1875, p. 368. On p. 357 of the same journal there is another paper by 

D.C.Davies on the same region. W. D. Matthew (Trans. New York Acad. Sci., vol. 12, p. 108) has described 

phosphatic nodules from the Cambrian of New Brunswick.

2 Quart. Jour. Geol. Soc., vol. 31,1875, p. 370.

s Idem, vol. 42,1886, p. 325.

«M6m. Soc. ingfin. civils, August, 1897, p. 193. Analyses of Algerian phosphates, by H. and A. Malbot, 

are given in Compt. Rend., vol. 121,1895, p. 442. The phosphorites of Tunis are described by P. Thomas 

In Bull. Soc. geol. France, 3d ser., vol. 19, 1891, p. 370. See also O. Tietze, Zeitschr. prakt. Geologic, 

1907, p. 229, on the phosphates of Tunis and Algeria. Tietze gives numerous references to the literature of 

these deposits. See also C. Pilotti, Pub. Corpo reale delle miniere, Rome, 1908.

5 Proc. Boston Soc. Nat. Hist., vol. 13,1870, p. 222, and also later in the introduction to R. A. F. Penrose'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, The phosphates of America, New York, 

1891; and C. C. H. Millar, Florida, South Carolina, and Canadian phosphates, London, 1892. The earlier 

literature is well summed up in Penrose's bulletin.

6 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. Rept.,pt.6,cont.,1899,p. 633; Twentyfirst Ann. Rept., pt. 3,1901, p. 473; and Bull. No. 213,1903, p. 418. L. P. Brown, Nineteenth Ann. Rept, 

pt. 6, cont., 1898, p. 547. E. C. Eckel, Bull. No. 213,1903, p. 424. The latest discussion, by Hayes and 

E. O. Ulrich, is given in Geol. Atlas U. S., folio 95,1903. See also T. C. Meadows and L. Brown, Trans. 

Am. Inst. Min. Eng., vol. 24,1895, p. 582; Hayes, idem, vol. 25,1896, p. 19; J. M. Saflord, Am. Geologist, 

vol. 18,1896, p. 261; and W. B. Phillips, Eng. and Min. Jour., vol. 57,1894, p. 417.
502 THE DATA OF GEOCHEMISTRY.

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 mollusks, such as lingula. 

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/ 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 limestones 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 Branner and J. F. Newsom, Bull. 

Arkansas Agr. Exp. Sta. No. 74, and A. H. Purdue, Bull. U. S. Geol. Survey No. 315,1907, p. 463. The 

Devonian black phosphates of the Pyrenees, described by D. Levat (Annales des mines, 9th ser., vol. 15, 

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 

Mm. Jour., voL 53,1892, p. 380. See also E. H. Sellards, Third Ann. Rept. Florida State Geol. Survey, 

1909-10.
THE DECOMPOSITION OF BOCKS. 

Analyses of Florida phosphates.

503

A. From near Sunnyside, Tjaylor County.

B, C. From LuravBle district, Suwanee County.

D. From Albion district, Levy County.

SiO............................................

TiO;.................... :...................

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

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

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

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

K,,0.........................................

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

p r.jUn s ........................................

G02 ....... ..................................

so3 . .........................................

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

H20 at 105°...............-.. .................

A

3.44

.13

1.49

1.43

48.81

.23

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

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

21.17

3.10

23. 95

.15

| .40

25.38

2.14

.15

1.42

1.27

10. 35

100. 57 

.60

99.97 

.22

A new phosphate field, probably the largest known, is in the States 

of Idaho, Wyoming and Utah. At the date of writing it is still under 

investigation.1 The subjoined partial analyses of rock from this 

region are also by Mr. Steiger.

Analyses of western phosphates.

A. 2$ miles west of Cokeville, Wyoming. 

B. Dunellan lode, 8 miles southwest of Sage, Utah. 

C. Elsinore claim, 3 miles west of Devils Slide, Utah. 

D. 8 miles southeast of Georgetown, Idaho.

Insoluble ....................................

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

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

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

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

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

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

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

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

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

C02 ...........................................

P O

s6°f::::::::.v.::::::::::::::::::::::::::::::::

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

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

A

2.62

.46

.97

.40

.35

48.91

.97

.34

1.02

1.34

2.42

33.61

2.16

.40

95.97

B

1.82

.30

.50

.26

.22

50.97

2.00

.47

.48

.57

1.72

36.35

2.98

.40

99.04

C

9.40

undet.

.90

.33

.26

46.80

2.08

.58

.61

.75

2.14

32.05

2.34

.66

98.90

D

10.00

.89

.73

.28

45.34

1.10

.48

1.04

1.14

6.00

27.32

1.59

.60

96.51

1 See report by H. S. Gale and R. W. Bichards, Bull. U. S. Geol. Survey No. 430,1910, p. 457; and E. 

Blackwelder, idem, p. 537. Earlier reports by F. B. Weeks and W. F. Ferrier are in Bulls. 315 and 340.
504 THE DATA OF GEOCHEMISTRY. f

NOTE. For other data on American phosphates, see R. A. P. 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 l 

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. Rept. 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 scoie 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, Neues 

Jahrb., Beil. Bd. 22,1906, p. 48. On French phosphates, A. Nantier, Compt. Rend., 

vol. 108, 1889, p. 1174; and H. Lasne, Bull. Soc. ge"ol. France, 3d ser., vol. 18,1889-90, j 

p.441. ' 

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. . .

Several hydroxides of iron have been given definite rank as mineral / 

species. They are: '

Turgite.................. 2Fe203 .H20. Contains 94.6 per cent Fe203 .

Goethite.................. FeaOg.E^O. Contains 89. 9 per cent Fe2 03 .

Limonite............... 2Fe203 .3H20. Contains 85.5 per cent Fe203 . P

Xanthosiderite........... Fe2 03 .2H20. Contains 81.6 per cent Fe203 . |

Limnite.................. Fe203 .3H20. Contains 74.7 per cent Fe203 .

Of these only one, goethite, is crystalline; the others are amorphous, 

and all sorts of mixtures between them are likely to occur. 1 They i 

are also often admixed with siderite, FeC03 , which is itself an impor- | 

tant 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 

rarest 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

 » Perhaps the hydrogoethite, 3FeaO3 .4H2O, of P. A. Zemjatschensky (Zeitsch. Kryst. Min., vol. 20, p. 185) 

is such a mixture. 

2 See W. N. Hartley and H. Ramage, Jour. Chem. Soc., vol. 71,1896, p. 533.
THE DECOMPOSITION OF ROCKS. 505

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. 1 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. 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 above. The following analysis of a spring water, 

which rises under a layer of ore at Ederveen, Netherlands, is cited by 

Van Bemmelen 2 to indicate the source from which the iron oxides 

were derived. The figures refer to milligrams per liter.

Analysis of spring water at Ederveen, Netherlands.

Ca..................

M"

FP

Mil..................

K............. ......

Nti

Al O

01..................

............. 107.6

............. 5. 6

............. 19. 6

............. 11. 4

............. 0. 9

............. 10. 0

............. 3. 3

.............. 15.2

S04 .................

H3P04 ....... ........

cos ........... .......

SiO..................

0 Q

............ 10. 9

............ 207.6

............ 18. 0

............ 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 3 of Swedish lakes, in which layers of bog ore several inches 

thick accumulated in the course of twenty-six years. According to 

N. S. Shaler,4 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

1 On the pyritic origin of iron ores see H. M. Chance, Eng. Min. Jour., vol. 86, 1908, p. 408, and Trans. 

Am. Inst. Min. Eng., vol. 39,1909, p. 522. Chance regards this origin as very general.

2 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.

3 Text-book of geology, 4th ed., p. 187.

«Tenth Ann. Kept. U. S. Geol. Survey, pt. 1,1890, p. 305.
506 THE DATA OF GEOCHEMISTRY.

mud. 1 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.2 These organisms 

are found in the ground water and the soil. From sulphate solutions 

the iron may be precipitated by carbonates, phosphates, or 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 3 suggests that in some 

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. 4 

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 5 as formed by the replacement of lime in bryozoan 

remains; although C. H. .Smyth 6 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 7 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. 8

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

1 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, pt. 2, p. 273, ref.; J. H. L. Vogt, Zeitschr. prakt. Geologie, 1894, p. 30, and 

1895, p. 38; G. Reiriders, Verhandel. 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.

2 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.

a Ann. Rept. Geol. Survey Arkansas, vol. 1,1892, p. 124. See also L. Cayeux, Compt. Rend., vol. 142, 

1906, p. 895.

« See J. P. Kimball, Am. Jour. Sci., 3d ser., 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. Geol. 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.

5 Am. Jour. Sci., 3d ser., vol. 41,1891, p. 28.

»Idem, vol. 43,1892, p. 487.

7 See A. C. Spencer, Bull. U. S. Geol. Survey No. 340, 1908, p. 318; C. M. Weld, Bull. Am. Inst. Min. 

Eng. No. 32,1909, p. 749; C. K. Leith and W. J. Mead, idem, Bull. No. 51,1911, p. 217. The last bulletin 

contains five other papers on the Cuban ores.

8 See G. 0. Smith and B. Willis, Trans. Am. Inst. Min. Eng., vol. 30, p. 356.
THE DECOMPOSITION" OF ROCKS. 507

red, and in texture they differ as widely. J. M. van Bemmelen * 

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.2 According to P. Nicolardot,3 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.

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 in the memoir by

J. M. van Bemmelen, C. Hoitsema, and E. A. Klobbie.4 These variations are shown in ore from a single locality, and the substances mentioned are mostly crystalline. The Fe2O3 represents the amorphous 

variety.

Analyses of bog ore. 

A. By G. Eeinders. B. By E. A. Klobbie. C. By F. M. Jager. D. By C. H. Kettner.

Fe20,.... ......................................

FeC03 . ........................................

MnCCJ3 . .......................................

CaC03 . .......................................

MgC03 ........................................

Fe3 (P04 )2 . .....................................

Y&'pd?..... .................................

CaS04 . ........................................

A103 .........................................

KC1...........................................

NaCl...........................................

Soluble Si02 . ..................................

Organic matter. ................................

H20 at 100°.. . ................................

H20, ignition. .................................

A

10.58

20.77

4.04

2.27

.17

4.30

.07

.93

.03

.23

| 49. 30

1.57

3.68

2.'06

100. 00

B

2.49

37.70

.67

4.46

.10

1.75

.21

trace

.82

50.02

.03

.95

1.12

100. 32

C

8.0

30.6

4.0

2.9

1 49.1

1.8

| 3.3

99.7

D

36. 49

6.12

2.91

4.10

.21

' 5.47

1.76

.60

trace

trace

6.30

19.30

1.20

12. 10

4.00

100. 56

1 Rec. trav. chim., vol. 7,1838, 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. Chemie, 

2d ser., vol. 46,1892, p. 529.

2 See also W. Spring, Bull. Acad. Belgique,3d ser., vol. 34,1897, p. 578, on the relations of humus to iron in 

natural waters, already cited on p. 482, ante. The same subject has recently been discussed by 0. Aschan, 

Zeitschr. prakt. Geologie, vol. 15,1907, p. 56.

' Annaleschim.phys.,8th ser., vol. 6,1905,p.334. Nicolardot cites many references to former investigations upon the precipitated hydroxides. See also Otto Ruff, Ber. Deutsch. chem. Gesell., vol. 34,1901, 

p. 3417.

4 Zeitschr. anorg. Chemie, vol. 22,1900, p. 319.
508 THE DATA OF GEOCHEMISTRY.

The subjoined analyses of limonitic bog iron from Mittagong, 

Australia, are cited by A. Liversidge.1 They are quite different from 

those shown in the preceding group.

Analyses of Australian bog ores.

J?e,0a....... ..................................

A1203 - .....-...--..............--.--..--.-.-.-

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

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

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

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

P205 ....... ...................................

863?--............. ..........................

E

68.37

4.63

14.10

trace

3.00

9.72

99.82

F

57.61

24.30

6.41

trace

trace

1.20

10.38

99.90

G

74.71

3.04

.43

10.10

2.20

9.70

100. 18

U

65.84

4.49

1.40

.48

14.27

.25

.11

2.30

10.86

100. 00

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,2 

and similar nodular forms have been observed that were of recent

terrestrial origin. May Thresh 3 discovered small hard black nodules 

resembling seeds in the bowlder clay of Essex, England; and similar 

bodies were found by W. M. Doherty * on the surface of the ground in 

Australia.

Manganese differs from iron, however, in its degrees 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 .H20, corresponds in type with goethite 

and diaspore; and hausmannite, Mn304 , is the equivalent of magnetite, although the two species are crystallographically unlike. Polianite and pyrolusite, two crystallized forms of the dioxide, Mn02 , are 

not matched by any compound of iron, and this oxide forms the

1 Minerals of New South Wales, p. 99. The analyses were made by the "government analyst."

2 See p. 123, ante.

3 Jour. Chem. Soc., vol.' 82, pt. 2, ref. 567,1902. 

« Rept. Australasian Assoc. Adv. Sci., 1898, p. 339.
THE DECOMPOSITION OF BOCKS. 509

chief manganese ore. Braunite, to which the formula 3Mn203.MnSi03 

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 &re amorphous, 1 and probably represent colloidal 

complexes, such as were mentioned in connection with the sedimentary ores of iron. The following analyses represent substances in this 

class, ranging from the crystalline pyrolusite to the earthy wad, or 

bog manganese, the cupriferous lampadite, etc.:

Analyses of manganese ores.

A. Pyrolusite, Crimoramine, 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.

C. Psilomelane, Romaneche, France. Analysis by A. Gorgeu, Bull. Soc. min., vol. 13,1890, 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. 21; 

vol. 16, 1898, pp. 96,133. Also Bull. Soc. chim., 3d ser., 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 lepidophaeite, Kamsdorf, Thuringia. Analysis by Jenkins, for A. Weisbach, Neues 

Jahrb., 1880, pt. 2, p. 109. This mineral shows exceptionally high hydration.

MnO,. ......................

MnO'.........................

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

A12 03 ........................

PbO........................

CuO.........................

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

CoO.........................

ZnO.........................

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

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

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

KtO... .....................

Na2 0........................

H26-.... ..................

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

P2n Us. ........................

AB^I.. .....................

Sb^O,..,.. ...................

CaS04 ......................

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

Insoluble ...................

A

95.88

.62

.22

.27

.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

\ *

.40

16.20

.20

} .!0

| 4.65

1.50

.25

.15

100. 10

D

64.98

7.27

} 1.10

.30

1.65

15.45

trace

trace

.80

| 5.00

.05

.60

.40

.80

1.40

99.80

E

68.86

7.51

} 2.23

14.42

| 5.08

1 QR

100. 08

F

58.77

9.59

11. 48

1 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

i According to A. Gorgeu (Bull. Soc. min., vol. 13,1890, p. 27), the variety known as wad is sometimes 

crystallized.
510 THE DATA OF GEOCHEMISTRY.

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 

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,4 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.5

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 limonites 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, 6 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

i 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 oxides of manganese and iron, to which he gives the names vredenburgite, sitaparite, and beldongrite.

a Am. Jour. Sci., 4th ser., vol. 18,1904, p. 448. '

s Rec. Geol. Survey India, vol. 12,1879, p. 99; vol. 16,1883, p. 116.

«Am. Jour. Sci., 4th ser., vol. 12,1901, p. 18.

5 A very full monograph on manganese ores, by R. A. F. Penrose, forms vol. 1 of the Annual Report of 

the Arkansas Geological Survey for 1890. See also an article by Penrose, Jour. Geol., 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. H. 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.

6 Cited by G. Bischof, Lehrbuch der chemischen und physikalischen Geologic, 2d ed.. vol. 1, p. 540.
THE DECOMPOSITION OF BOOKS. 511

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 thermochemical 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 thermochemical equations used by Dieulafait are as follows:

2FeO + 0 = Fe203 + 26.6 Cal. 

2MnO + 20 - 2Mn02 + 21.4 Cal.

Hence, if oxygen acts on a mixture of FeO and MnO, or upon substances equivalent to them, ferric oxide will form first and be the

more stable.

FeO + CO2 = FeCO3 + 5.0 Cal. 

MnO+C02 =MnC03 + 6.8 Cal.

When 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, Fe2 03 and Mn02 

will both be formed; but if they act slowly, in small quantities, the 

oxygen will go to produce Fe2 03 , 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 Mn02 and 

CO2 later.

In the last of Dieulafait's papers he gives the heat of formation 

of several manganese compounds:

Mn + S, 22.6 Cal.

Mn + 0, 47.4 Cal.

Mn + 0 + C02 , 54.2 Cal.

Mn + O2 , . 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 2 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

i Compt. Rend., vol. 101,1885, pp. 609, 644, 676. 

a Am. Jour. Sci., 3d ser., vol. 36,1888, p. 175.
512 THE DATA OF GEOCHEMISTKY.

same time ferric sulphate and ferric hydroxide, under favorable 

conditions, may also be formed. In contact with manganese carbonate, in presence of air, 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 the 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.
CHAPTER XIII.

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 cemeriting 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 48.58

' On a classiflcation of the sedimentary rocks, see A. W. Grabau, Am. Geologist, vol. 33,1904, p. 228. 

"Haidinger's Berichte, vol. 2,1846-47, p. 107. 

4.m. Jour. Sci., 4th ser., vol. 9,1900, p. 352.

101381° Bull. 491 11 33 513
514 THE DATA OF GEOCHEMISTRY.

per cent have been found on the Astrakhan steppe, according to 

B. Doss, 1 who also mentions gypsiferous sandstones. Crystals of 

barite inclosing sand are also well known. J. E. Pogue 2 has described 

crystallized barite inclosing from 44 to 53 per cent of sand from the 

oasis of Kharga, Egypt; and H. W. Nichols 3 reports similar material 

found in Oklahoma. As a rule, however, the cementing material of 

a sandstone is quite 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.4 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,5 the interstitial space in a sandstone made up of 

closely packed spherical grains amounts to 25.96 per cent. C. R. 

Van Hise 6 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.7 Calcium carbonate is the most abundant salt derivable from percolating waters, and is easily deposited

therefrom; hence its frequency in the sediments, even in those which 

are not laid down in contiguity 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

1 Zeitschr. Deutsch. geol. Gesell., vol. 49,1897, p. 143.

2 Proc. U. S. Nat. Mus., vol. 38,1910, p. 17. Pogue gives a good list of other occurrences.

s Pub. No. Ill, Field Columbian Mus., 1906, p. 31.

< 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. 24,1882, 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, 

5th ser., vol. 2,1852, p. 5; and A. Daubre"e (Etudes synthetiques de geologic expfirimentale, pp. 226-230) 

cites a number of European examples.

5 Mon. U. S. Geol. Survey, vol. 13,1888, p. 399.

«Idem, vol. 47,1904, p. 863.

' Calcium carbonate, up to nearly 30 per cant, 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 the Bull. 

Mus. Comp. Zool., 1904. Branner mentions similar reefs in the Levant.
SEDIMENTARY AND DETEITAL BOOKS. 515

sandstone from Lohne, Westphalia, by W. von der Marck, 1 may 

illustrate the complexity of these mixtures.

Analysis of sandstone from Westphalia.

Insoluble portion. . . . . .<

\Ga.GO,.. ..............

MgCO...... ...........

FeC03 .. ...............

Ca P 0

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

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

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

Al O

H 20

............... 39.50

............... 7. 23

............... 7. 54

............... 3. 90

............... .82

............... 2. 12

............... 36.65

91

............... .03

CO

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,2 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 3 

found 13.60 per cent of P205 , equivalent to 22.64 of Ca3P208 . In the 

same sandstone 4.98 per cent of calcium fluoride was also present. 

Calcium fluoride has also been reported by W. Mackie 4 as a cementing material in a Triassic sandstone from Elginshire, Scotland in 

one case up to 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 5 has described specimens containing from 

28.20 to 50.06 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. 8 

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.

1 Verhandl. Naturhist. Ver. preuss. Rheinlande u. Westphalens, vol. 12, 1855, p. 269. Many other 

similar analyses are given. G. Bischof (Lehrbuch der chemischen und physikalischen Geologie, 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.

2 Seventeenth Ann. Eept. U. S. Geol. Survey, pt. 2,1896, pp. 527, 539.

s Jahrcsber. Chemle, 1852, p. 980.

< Eept. Brit. Assoc. Adv. Sci., 1901, p. 649. See also 0. Miigge, Centralbl. Min., Geol. u. Pal., 1908, p. 33.

s Proc. Roy. Soc., vol. 46,1889, p. 363; vol. 64,1899, p. 374. See also W. Mackie, Kept. Brit. Assoc. Adv. 

3ci., 1901, p. 649; C. B. Wedd, Geol. Mag., 1899, p. 508; and C. C. Moore, Proc. Liverpool Geol. Soc., vol. 8, 

1898, p. 241. Moore gives several good analyses of sandstones. In some of them small amounts of cobalt 

and nickel were found.

«See ante, p. 193. See also R. Delkeskamp, Notizbl. Ver. Erdkunde, 4th ser., Heft 21,1900, p. 47.
516 THE DATA OF GEOCHEMISTBY.

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, 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 their 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. Their 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

i Described by W. S. Bayley in Bull. U. S. Geol. Survey No. 150,1898, p. 84. Compare C. E. Van Hise. 

Am. Jour. Sci., 3d ser., vol. 31,1886, p. 453, for data concerning other similar rocks in the same region.

zZeitschr. Deutsch. geol. Gesell., vol. 34,1S82, p. 771.

3 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. 150,1898, pp. 72-84.
SEDIMENTARY AND DETKITAL BOOKS. 517

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, and 

therefore in the sandstones. The feldspars and ferromagnesian minerals, however, are quite commonly altered or even removed, the more 

stable 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 folio whig 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. Schneider. Described by J. S. Diller, 

Bull. U. S. Geol. Survey No. 150,1898, p. 80. Nearly pure quartz.

B. Brown sandstone, Hummelstown, Pennsylvania. Analysis by Schneider. Described by Diller, 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. Phillips, Quart. Jour. Geol. Soc., vol. 37,1881, p. 6. Consists of quartz grains cemented by brown 

iron Ore, With very little feldspar and mica. 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. Geol. Soc. America, vol. 1,1889, p. 411. Made up of quartz, feldspar, and biotite, with a 

calcite cement. Contains also serpentine, tttanite, magnetite, and zircon. Other "sandstone dikes" near 

Pikes Peak, Colorado, have been described by W. Cross. They probably represent quicksands which were 

injected into fissures. See also C. O. Crosby, Bull. Essex Inst., vol. 27,1895, p. 113.

E. Miocene sandstone, Mount Diablo, California. Analyzed and described by W. H. Melville, Bull. 

Geol. 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. Bayley, Bull. 

U. S. Geol. Survey No. 150,1898, p. 84. Contains quartz, feldspars, iron oxides, and probably kaolin. In 

the cement are chlorite, quartz, magnetite, pyrite, rutile, sometimes biotite, and either muscovite or kaolin.

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

TiO

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

FeA- -..---- .......

FeO.................

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

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

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

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

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

Na20...............

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

Li./)................

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

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

P O

oS?:::.v.:::::::::::

S03 . .................

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

A

99.42

1 31 1 ' 6L

\ 18 r - i&

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

.4.2

100. 03

D

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

78.63

.25

4.78

1.08

.30

trace

5.52

.05

H7

' .45

1.32

.31

"1.33

.08

5.04

.07

trace

100. 41

G

84.86

.41

5.96

1.39

.84

trace

1.05

.01

.52

.76

1.16

.27

«1.47

.06

1.01

.09

trace

99.86

H

76.84

11.76

.55

2.88

trace

.70

1.39

2.57

1.62

} 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

»For additional analyses, see 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 Geol. Soc., vol. 8,1899, pp. 58, 

59) give a number of good analyses of Scottish sandstones. See also C. C. Moore, Proc. Liverpool Geol. 

Soc., vol. 8,1898, p. 241, for English examples.
518 THE DATA OF GEOCHEMISTRY.

L. Cayeux l 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 any 

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 

theory. That the replacement of calcium carbonate by silica is possible, no one can deny, for silicified shells and corals are common.

1 M6m. Soc. gfiol. 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 dissolve, the rate of solijtion 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. 3,1890) and a paper by the 

same author in Proc. Boston Soc. Nat. Hist., vol. 26,1894, p. 414. Compare also O. 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 rocks of this character.

s Quart. Jour. Geol. Soc., vol. 50,1894, p. 380.

* E. Hull and E. T. Hardman, Sci. Traps. Roy. Dublin Soc., new ser., vol. 1, 1878, pp. 71, 85, on the 

Carboniferous cherts of Ireland; A. Renard, Bull. Acad. 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. 519

The pseudomorphs of chalcedony or opal after coral, from Tampa 

Bay, Florida, are conspicuous examples of this change. Furthermore, 

A. H. Church 1 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.

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,2 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.3 Cherts crowded

with these spicules have been described by various authors, especially by W. J. Sollas 4 and G. J. Hinde. 5. 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.6 In order to 

account 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. 

Julien 7 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 8 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 concretions,

1 Jour. Chem. Soc., vol. 15,1862, p. 107.

2 Lawson, Fifteenth Ann. Kept. U. S. Geol. Survey, 1895, p. 420; Lawson and Palache, Bull. Dept. Geology Univ. California, vol. 2,1902, pp. 354,365; Ransome, idem, vol. 1,1894, p. 193.

8 See Thoulet, Bull. Soc. min., vol. 7,1884, p. 147.

«Ann. and Mag. Nat. Hist., 5th ser., vol. 6,1880, pp. 384,437; vol. 7,1881, p. 141.

o Phil. Trans., vol. 176,1885, p. 403; Geol. Mag., 1887, p. 435; idem, 1888, p. 241.

8 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. Zool., vol. 28, 1895, p. 1) has described fossil sponges from flints found in the 

Cretaceous near Austin, Texas.

' Proc. Am. Assoc. Adv. Sci., 1879, p. 396.

s See ante, p. 194.
520 THE DATA OF GEOCHEMISTRY.

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. 1 It is 

possible that a single formation may represent more than one of 

these processes. R. D. Irving and C. R. Van Hise,2 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: 3

Analyses of chert and allied rocks.

A. Novaculite, Rockport, Arkansas. Analysis by R. N. Brackett. From Griswold's monograph, p. 167.

B. Chert, Belleville, Missouri. Analysis by E. A. Schneider, Bull. U. S. Geol. Survey No. 228,1904, 

p. 297. Other analyses are given on the same page.

C. Chert from the Upper Carboniferous of Ireland. Analysis by E. T. Hardman, Sci. Trans. Roy. Dublin Soc., new ser., vol. I,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, Rept. U. S. Geol. Explor. 40th Par., vol. 

2,1877, p. 768.

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

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

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

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

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

CaC03 ...............................

CaS04 ...............................

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

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

Na/K....... ........................

P O

Ignition. .............................

A

QQ 47

.17

.12

OQ

.05

.07

.15

.12

100. 24

B

98.17

}. .83

.05

.01

.78

99.84

C

95.50

.10

1.95

.15

.87

trace

trace

1.43

100. 00

D

98.72

} .54

.09

1 .26

.34

99.95

E

86. 70

4.09

1.26

.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.

1 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, Abhandl. Gesell. Isis, 1892, p. 115. See also G. R. Wieland, Am. 

Jour. Sci., 4th ser., vol. 4,1897, p. 262, who ascribes these oolites to the agency of hot springs.

2 Tenth Ann. Rept. U. S. Geol. Survey, pt. 1,1890, p. 397. See also C. R. Van Hise, A treatise on metamorphism: Mon. U. S. Geol. Survey, vol. 47,1904, pp. 847-853.

3 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 PsOs.
SEDIMENTARY AND DETEITAL BOCKS. 521

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 aconsolidated 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 

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 419, pages 211-218.

1 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.
522 THE DATA OF GEOCHEMISTRY.

Analyses of shales.

A. 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 W. 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 W. H. Melville.

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

TiO

AI o

Fe203 ---- -------------

FeO. ................

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

ZnO........... .......

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

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

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

Na2 0....... ..........

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

LiaO..................

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

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

P205 .. ................ cb2 !..................

S03 ..................

s. ...................

0.....................

Hydrocarbons. .......

Organic matter. ......

Pyrite. ...............

Cnalcopyrite. .........

A

60.15

.76

16.45

4.04

2.90

trace

1.41

.04

2.32

1.01

3.60

.89

3.82

.15

1.46

.58

.88

100. 46

B

55.43

.46

13.84

4.00

1.74

trace

5.96

.06

2.67

1.80

2.67

trace

2.11

3.45

.20

4.62

.78

~.69

100. 48

C

61.25

.66

15.60

1.35

3.04

.07

.03

3.40

4.16

.44

6.74

trace

.62

2.09

.08

.25

.03

99.81

D

55.02

.65

21.02

5.00

1.54

1.60

.04

2.32

.81

3.19

.03

2.44

5.65

.06

.83

.02

a. 32

100.54

E

51.03

13. 47

8.06

.78

1.15

.41

3.16

1 81 / ' 8i

.31

7.29

13.11

3.32

6102.90

F

45.89

.52

13.24

3.88

12.09

2.12

.47

2.31

1.38

4.16

.17

10.38

3.47

100. 08

G

41.32

.48

20.71

2.59

5.46

.17

9.91

1.91

7.19

.88

8.78

.08

.55

100. 03

H

25.05

8.28

.27

2.41

4.11

27.87

2.61

1.44

2.86

.08

24.20

99.18

a Carbonaceous matter. 6 Less 0=8,100.17.

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 

reagent 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 silicates 

and the residual feldspars. Scales of detrital mica are, of course, 

common in the sediments; but in the slates the feldspar grains have
SEDIMENTARY AND DETBITAL BOCKS. 523

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 chlori'tes, evidently, were derived from the debris 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 ottrelite, 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

Analyses of roofing slates.

A. Sea-green slate, Pawlet, Vermont. B. Purple slate, Castleton, Vermont. C. Black slate, Benson, 

Vermont. D. Red slate, near Hampton Village, New York. E. Green slate, near Janesville, New York. 

F. Black slate, Slatington, Pennsylvania.

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

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

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

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

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

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

Na20..........................

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

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

H20+.-. ......................'.

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

C02 ....... ...................

P 0

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

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

FeS2 .........................

NH3 .........................

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

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

.01

100. 23

C

59.70

16.98

.52

4.88

3.23

1.27

1.35

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

.05

.10

.04

.03

100. 00

E

56.49

11.59

3.48

1.42

6.43

5.11

.52

3.77

.37

2.82

.48

7.42

.09

.30

.06

.03

100. 38

F

56.38

15.27

1.67

3.23

2.84

4.23

1.30

3.51

.77

4.09

.78

3.67

.17

OQ

.08

1.72

.59

100. 39

1 Geol. Mag., 1894, pp. 36, 64; idem, 1896, pp. 309, 343.

2 See especially W. M. Hutchins, loc. cit.; H. C. Sorby, Quart. Jour. Geol. Soc., vol. 36, Proc., 1880, pp. 

66-80; 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.

3 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 (Allgem. chem. Geol., vol. 2, p. 588) tabulates 15 analyses of European clays 

and shales, and H. Rosenbusch (Elemente der Gestelnslehre, 2d ed.,p. 442) gives a table of 19. See also 

E. C. Eckel, Jour. Geology, vol. 12,1904, p. 25, for the average composition of 36 American roofing slates.
524 THE DATA OF GEOCHEMISTRY.

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 "stinkstone" of certain well-known localities. 

This pecularity is well shown by a bed of calcite 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, 

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, 2 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 rock of this class is stalagmitic, from 

caverns, and some of it is formed by springs.3 Its variations in color

1 Am. Jour. Sci., 4th ser., vol. 19,1905, p. 345.

2 See ante, p; 192. Analyses of tufa and travertine are there given.

a 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 calcite, rarely aragonite.
SEDIMENTARY AND DETBITAL BOCKS. 525

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. 1

When fresh waters, charged with carbonates, enter the sea, a direct 

precipitation of calcium carbonate may occur. This form of deposition, however, is exceptional, and few authentic examples of it are 

recorded. 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, 2 in the delta of the Rhone, and a 

similar precipitate has been reported along the coast of Florida.3

At Pyramid and Winnemucca lakes, in Nevada, great masses of 

calcareous tufa are formed, and sometimes, according to I. C. Russell,4 the deposit takes the shape of oolitic sand. In the latter instance 

the precipitated 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 5 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 6 to the action of 

minute algae. This mode of formation needs to be considered further.

In 1864 Ferdinand Cohn 7 studied the formation of travertine at 

the waterfalls of Tivoli. He found there that many aquatic plants, 

especially species of CTiara, mosses, and algae, 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

i On the solubility of calcium carbonate and other carbonates of the series RCOj in pure and carbonated 

water, see J. von Essen, Thesis, Univ. Geneva, 1907.

a Principles of geology, 12th ed., vol. 1, p. 426.

a See S. Sanford, Second Ann. Eept. Florida Qeol. Survey, 1908-9, pp. 224-5,228. Also T. W. Vaughan, 

Pub. 133, Carnegie Inst. Washington, 1910, pp. 114,168 et seq.

«Mon. U. S. Geol. Survey, vol. 11,1885, pp. 61,189.

"Idem, vol. 1,1890, p. 167.

o 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.

'Neues Jahrb., 1864, p. 580. An earlier paper by Cohn (1862), 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, 1889, p. 613) 

has shown that the travertine formed around the hot springs of the Yellowstone National Park is produced by the aid of algse.
526 THE DATA OP GEOCHEMISTRY.

of its second molecule of carbonic acid, and the insoluble neutral cavbonate 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* 

pointed out that CTiara took an active part in the production of freshwater marl. In 1900 C. A. Davis 2 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, CJiara, 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 3 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 algse. 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.4 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 precipita-

' First Ann. Rept. Geol. Survey New Jersey, 1855, p. 50. See also G. H. Cook, Geology of New Jersey, 

1868, p. 172.

2 Jour. Geology, vol. 8, 1900, pp. 485, 498; vol. 9,1901, p. 491.

3 Twenty-fifth Ann. Rept. 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, Geol. Survey Michigan, 

1900.

«Ber. Naturforsch. Gesell. Freiburg, vol. 4,1889, p. 288.
SEDIMENTARY AND DETBITAL BOOKS. 527

tion 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 distinct modifications calcite and aragonite. Calcite 

crystallizes in the rhombohedral 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.1 

Aragonite alters easily to paramorphs of calcite, but the reverse 

change rarely, if ever, occurs. The reported paramorphs of aragonite after calcite are of doubtful authenticity.

In recent years two other varieties of calcium carbonate have been 

described as distinct from calcite and aragonite. The carbonate of 

some molluscan shells, which had been called aragonite, was made 

into a distinct species by Agnes Kelley,2 who named it conchite. The 

pisolite formed at the hot springs of Hammam-Meskoutme, Algeria, 

was given specific rank by A. Lacroix,3 under the name ktypeite. 

Both of these alleged species have since been identified with aragonite 4 and need no further consideration here.

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.5 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 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. 366, 378; vol. 27,1897, p. 477; and vol. 30, 1899, pp. 295, 485. See also 0. Mugge, Neues Jahrb., 

Bell. Bd. 14, 1901, p. 246, and H. Leitmeier, Neues Jahrb., 1910, Bd. 1, p. 49. On the conditions under 

which calcite and aragonite are formed as chemical precipitates see W. Meigen, 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.

2 Mineralog. Mag., vol. 12,1900, p. 363.

8 Compt. Rend., vol. 126,1898, p. 602. For another description of this deposit see L. Duparc, Arch. scl. 

phys. nat., 3d ser., vol. 20,1888, p. 537.

< On conchite, see R. Brauns, Centralbl. Min., Geol. u. Pal., 1901, p. 134. H. Vater (Zeitschr. Kryst. 

Min., vol. 35,1902, p. 149) examined both conchite and ktypeite. Vater also describes the Carlsbad "sprudelstein," which is aragonite.

«Centralbl. Min., Geol. u. Pal., 1901, p. 577; Ber. Oberrhein. geol. Verein, 1902, p. 31; Ber. Naturforsch. 

Gesell. Freiburg, vol. 15, 1905, p. 55. See also A. Hutchinson, Mineralog. Mag., vol. 13, Proc., 1903, p. 

xxviii; G. Wyroubofl, Bull. Soc. min., vol. 24,1901, p. 371; and S. Kreutz, 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.
528 THE DATA OF GEOCHEMISTBY.

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 

in his 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. Only 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.6 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. Geol. Soc., vol. 35, Proc., 1879, p. 56.

2 Geol. Mag., 1888, p. 66. See also P. Tesch, Proc. Sec. Scl., Amsterdam Acad., vol. 11,1908, p. 236; A. 

R. Horwood, Geol. Mag., 1910, p. 173; and G. A. J. Cole and 0. H. Little, idem, 1911, p. 49.

» Kept. Brit. Assoc. Adv. Sci., 1896, p. 789.

«Idem, 1896, p. 791.

5 M6m. Soc. gfiol. du Nord, vol. 4, pt. 2,1897, p. 518.

8 See C. Wyville Thomson, Depths of the sea, London, 1874, pp. 467, 501.

»0p.cit.,p.257.

8 Neues Jahrb., Beil. Bd. 16, p. 495. Linck gives a good summary of previous literature upon oolite. 

See also H. Fischer, Monatsh. Deutsch. geol. Gesell., 1910, p. 247.
SEDIMENTARY AND DETEITAL BOCKS. 529

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 Meigsn'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° aragonite was formed. In sea water, then, the separation of calcium carbonate in one modification or the other is conditional upon the process 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 carbonate 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 * 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 

locality, the gases were composed as follows:

1 See R. Brauns, Chemische Mineralogie, pp. 377-378, for a summary of this subject. 

101381°^Bull. 491 11 34
530 THE DATA OF GEOCHEMISTRY.

, Gases extracted from sea water collected at different depths.

N02

f^f\

862 fathoms 

(bottom).

17.22

34.50

48.28

100. 00

800 fathoms.

17.79

48.46

33.75

100. 00

750 fathoms.

18.76

49.32

31.92

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, 2 limonite, deposited by a chalybeate 

spring, serves as the cementing substance.

In the Bay of Naples, according to J. Walther,3 calcareous algae, 

especially of the genus Lithothamnion, are conspicuous makers of 

limestone; and similar observations have been made elsewhere by 

others. ' Lithothamnion is a seaweed whose framework or skeleton 

consists of calcite; another genus, Halimeda, which is also active in 

limestone making, contains aragonite.

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, arid 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 

pure carbonate of lime, but a little organic matter is also present,.

1 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.

2 Am. Jour. Sci., 3d ser., vol. 34, 1887. p. 163.

3 Zeitschr. Deutsch. geol. Gesell., vol. 37,1885, p. 329. 

.«Bull. Mus. Comp. Zool., vol. 42, 1903, pp. 53-126.
SEDIMENTARY AND DETBITAL ROCKS. 531

some earthy matter, and very small quantities of calcium phosphate. 

In corals from the Gulf Stream S. P. Sharpies * found from 95.37 

to 98.07 per cent of CaC03 , and 0.28 to 0.84 of Oa3P208 - 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 a,re 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 calcium carbonate may be apparently fused. 

Over a century ago Sir James Hall * heated limestone in closed

i Am. Jour. Sci., 3d ser., vol. 1,1871, p. 168.

a See, for example, A. Liversidge, Proc. Roy. Soc. New South Wales, vol. 14,1880, p. 159; on coral from 

New Hebrides, and coral rock from Duke of York Island. Also A. J. Jukes-Brown and J. B. Harrison, 

Quart. Jour. Geol. Soc., vol. 47, 1891, p. 224, «n coral rocks from Barbadoes. A number of analyses of 

coquina, coralline limestones, etc., are given in Bull. U. S. Geol. Survey N«. 228, 1904. Several analyses 

by H. W. Nichols appear in Pub. Ill, Field Colombiui Mug., IMS, p. 31.

aZeitschr. a'horg. Chemie, vol. 11,1896, p. IflO.

«Trans. Roy. Soc. Edinburgh, vol. 6, 1812, p. 71. The experiments were performed in 1805. For a 

summary of the results obtained by Bucholz, Petzholdt, and Richthofen, see J. Lemberg, Zeitschr. Deutsch. 

geol. Gesell., vol. 24, 1872, pp. 237-241. Lemberg criticizes the conclusions drawn from Hall's data, and 

expresses a strong doubt as to whether fusion actually occurred.
532 THE DATA OF GEOCHEMISTRY.

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, 1 

however, transformed a compact limestone into marble as Hall had 

done, but without evidence of fusion; and A. Becker,2 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 3 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 4 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 suggets that the melting point of calcium carbonate may perhaps be 

lowered by pressure. H. E. Boeke, 5 however, found that although

the carbonate sinters together at temperatures between 1,400° and 

1,500°, under a pressure of 30 atmospheres of carbon dioxide, it 

undergoes partial dissociation, but does not appear to fuse.

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 nor occur; at all events 

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

1 Pogg. Annalen, vol. 118,1863, p. 565.

2 Min. pet. Mitt., vol. 7,1886, p. 122. Becker also gives a good summary of the earlier literature of the 

subject.

3 Compt. Rend., vol. 115,1892, pp. 817,1009. Two papers. 

«Idem, vol. 115,1892, pp. 934,1236. Two papers.

( Zeitschr. anorg. Chemie, vol. 50,1906, p. 244. Boeke found that aragonite is transformed into calcite 

at about 470°.
SEDIMENTARY AND DETRITAL. EOCKS. 533

no more than to dissolve and redeposit particles of carbonate, it 

would go far toward producing the observed change in structure. 

Under those 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 (Siderostria), Bermuda. Analysis by L. G. Eakins. 

G. Composite analysis, by II. N. Stokes, of 345 limestones.

H. Composite analysis by Stokes of 498 limestones used for building purposes. Does the high proportion of silica determine the availability of these rocks to structural ends? 

Ideally pure calcium carbonate contains 56.04 per cent of CaO and 43.96 of COj.

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

TiO...................

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

Fea08 ......... ........

FeO.......... .........

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

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

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

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

NazO... ...... ........

Li.,0......... .........

H,0......... .........

H2 0+... ..............

P O

c$r.::.v.::::::::::::

s......................

S08 .. ........ ....... ci.....................

Organic.......... ......

A

0.95

.09

none

.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

.,8

.06

40.34

.07

99.84

C

1.15

} .45

.26

53.80

.56

} .07

.23

.69

42.69

none

99.90

D

« 4. 03

| .20

51.33

.72

. bo

} .83

41.07

.89

.27

99.97

E

0.25

} .56

51.52

2.08

} 3.19

41.58

99.18

F

0.23

1>trace

55.16

.20

1 54 \ -M

43.74

99.87

G

5.19

.06

.81

1 ^4 }

.05

42.61

7.90

.33

.05

irci^c*

.21

6.56

.04

41.58

no

.05

.02

100. 09

H

14.09

.08

1.75

1 .77

.03

40.60

4.49

.58

.62

f"PQf»O

.30

&.88

.42

35.58

.07

.07

.01

100. 34

o Insoluble in hydrochloric acid. & 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. Rept. Geol. Survey Arkansas, vol. 4,1890; S. W. McCallie, Bull. No. 1, Geol. 

Survey Georgia, 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. No. 44, New York State Mus., 

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, Bull. 

Qeol. Soc. America, 1909, vol. 20, p. 153.
534 THE DATA OF GEOCHEMISTRY.

guano islands.1 By oxidation of inclosed pyrite, acid sulphates can 

be formed, and these will 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. By far 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 1 

foot in nine thousand years.

DOLOMITE.

In the foregoing pages upon limestone, the magnesian varieties 

have been purposely left out of account. They represent transitions 

from calcium carbonate to dolomite, CaMg(CO3 ) 2 , a rock of great 

importance both practically and theoretically, and one which demands separate consideration. In addition to dolomite, it is neces1 On the silicification of limestones see F. Kuhlmann, Ann. Chem. Pharm., vol. 41,1842, p. 220; J. Lembe.rg, Zeitschr. Deutsch. geol. Gesell., vol. 28, 1876, p. 562; and W. Clemm, Inaug. Diss. Freiburg, 1909. 

On the silicification of fossils, R. S. Bassler, Proc. U. S. Nat. Mus., vol. 35,1908, p. 133. On phosphatization 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.

8 See I. C. Russell, Bull. U. S. Geol. 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, 

i Compt. Rend., vol. 118, 1894, p. 262. 

»Am. Jour. Sci., 3d ser., vol. 29, 1885, p. 29. 

«Or 29.173 grams per square meter.
SEDIMENTARY AND DETRITAL ROCKS. 535

sary also to consider magnesium carbonate itself, magnesite, and its 

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 * 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 ° 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

i Cited in a memoir by A. Favre, Compt. Rend., vol. 28,1849, p. 364.

a Idem, vol. 33, 1851, p. 64.

s Idem, vol. 47, 1858, p. 91.

< Jahresber. Chemie, 1847-48, p. 1290. Also Compt. Rend., vol. 26,1848, p. 311.

<sRept. Brit. Assoc. Adv. Sci., 1856, p. 77.

«Am. Jour. Sci., 2d ser., vol. 28, 1859, pp. 170, 365; vol. 42, 1866, p. 49.
536 THE DATA OP GEOCHEMISTRY.

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.

Still more recently G. Linck * 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.

In several instances the deposition of magnesian travertine and 

even of crystallized dolomite from natural waters has been observed. 

According to J. Girardin,2 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 3 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.4 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 5 found that springs 

from the dolomites of the Jura, which contain calcium and 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,6 when artificial solutions of calcium and 

magnesium bicarbonate were allowed to evaporate spontaneously at 

ordinary temperatures. Only mixtures were formed, no dolomite.

iMonatsh. Deutsch. geol. Gesell., 1909, p. 230. W. Meigen (Geol. Rundschau, vol. 1, 1910, p. 131) 

repeated Linck's experiment, but unsuccessfully. 

2 Annales des mines, 3d ser., vol. 11,1837, p. 460. 

sjahresber. Chemie, 1866, p. 178.

< Cited by L. Lartet, Bull. Soc. g6ol. France, 2d ser., vol. 23,1866, p. 750. 

6 Liebig's Annalen, 8th Supp. Bd., 1872, p. 230. 

iNeues Jahrb., 1866, p. 1.
SEDIMENTARY AND DETBITAL BOOKS. 537

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 calcuim 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. Klement'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, 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 tune, 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

Two other investigations upon the synthesis of dolomite remain 

to be mentioned. L. Bourgeois and H. Traube 4 obtained it by heating a solution of magnesium chloride, calcium chloride, and potas1 Zeitschr. Deutsch. geol. Gesell., vol 27,1875, p. 509. In this connection It may be noted that H. C. Sorby 

(Quart. Jour. Geol. Soc., vol. 35, Proc., 1879, p. 56) found that Iceland spar, in a solution of magnesium 

chloride, became slowly incrusted with magnesium carbonate.

a Bull. Soc. beige gfiol., vol. 9, M6m. 3,1895. Min. pet. Mitt., vol. 14,1894, p. 526. See also experiments 

by O. Mahler; Inaug, Diss., Freiburg, 1906.

s See Blum's Pseudomorphosen, p. 51, and Nachtrag, p. 23.

«Bull. Soc. min., vol. 15,1892, p. 13.
538 THE DATA OP GEOCHEMISTRY.

slum 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. PfafiY 

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 a 

later paper, however, Pfaff 2 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 MgCO3 .3H20, which corresponds to the rare mineral nesquehonite. This species, described 

by F. A. Genth and S. L. Penfield,3 from the Nesquehoning anthracite mine in Pennsylvania, was there produced by the alteration of a 

basic carbonate, lansfordite,4 3MgC03 .Mg(OH) 2 .2lH20, which first 

formed as stalactites in one of the galleries. Nesquehonite has since 

been identified by G. Friedel 5 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, 

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 lime1 Neues Jahrb., Beil. Bd. 9,1894, p. 485. A later paper by Pfaff is published in vol. 23,1907, p. 529.

2 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. 397), 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.

s Am. Jour. Sci., 3d ser., vol. 39,1890, p. 121.

« Described by Genth, Zeitschr. Kryst. Min., vol. 14,1888, p. 255.

6 Bull. Soc. min., vol. 14,1891, p. 60. See also H. Leitmeier (Zeitschr. Kryst. Min., vol. 47,1909, p. 118) 

on the deposition of magnesian hydrocarbonates by the mineral springs of Rohitsch, Styria.
SEDIMENTARY AND DETBITAL BOCKS. 539

stones 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 microchemical 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 

reagent deposits a violet coating upon calcite surfaces, but leaves 

dolomite uncolored. According to F. Cornu,3 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 4

i Upon these differences in solubility, there is an abundant literature, which has been well summarized 

by A. Vesterberg, Bull. Geol. Inst. Upsala, vol. 5,1901, p. 97; vol. C. 1905, p. 254., See also the synthetic 

papers already cited, and Haushofer, Sitzungsb. Akad. Miinchen, vol. 11,1881, p. 220.

* Zeitschr. Deutsch. geol. Gesell., vol. 40,1888, p. 357. In vol. 39,1887, p. 489, Lemberg describes tests 

based upon the use of ferric chloride and ammonium sulphide. In a still earlier paper (op. cit., vol. 24,1872, 

p. 226) Lemberg gives tests with silver nitrate, which stains calcite and dolomite, after ignition, unequally. 

See also Otto Meyer, Zeitschr. Deutsch. geol. Gesell., vol. 31,1879, p. 445.

* Centralbl. Min., Geol. u. Pal., 1906, p. 550.

«Verhandl. Naturforsch. Gesell. Basel, vol. 15, 1903, p. 201. 0. Mahler (Inaug. Diss., Freiburg, 1906) 

finds the ferric chloride unsatisfactory, but obtained good results with the copper salt.
540 THE DATA OF GEOCHEMISTRY.

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 1 

described a "fresh-water dolomite" near Ulm, in Bavaria; and C. 

W. Giimbel, 2 studying the dolomites of the same region, which are 

interbedded with limestones, likewise asserts their sedimentary origin. T. Scheerer 3 also argues that the oldest dolomites were formed 

as chemical precipitates; and T. Sterry Hunt's 4 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. When the carbonates are thrown down together, 

heat and pressure may combine to bring about their union. These 

suggestions relate to possibilities only; and it would be rash to assert 

positively that dolomites are ever formed on a large scale by direct 

sedimentation.

Magnesian carbonates are, however, deposited with calcium carbonate by marine organisms, albeit in small relative amounts. G. Forchhammer 5 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 confirmed by many other investigators. In LitTiothamnium nodosum 

Giimbel 6 found 2.66 per cent of MgO and 47.14 of CaO; and A. G. Hogbom 7 in fourteen analyses of algae belonging to this genus reports 

from 1.95 to 13.19 per cent of MgC03 . To these higher figures reference will be made later. In the skeleton of a recent crinoid, H. W. 

Nichols 8 found about 11 per cent of magnesium carbonate, a result 

which has been confirmed by C. Palmer in the laboratory of the U. S. 

Geological Survey.

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, 9 show this fact very

1 Neues Jahrb., 1840, p. 371.

2 Sitzungsb. Akad. Miinchen, 1871, Heft 1, p. 45.

3 Neues Jahrb., 1866, p. 1.

< See Chemical and geological essays, p. 80, and the literature already cited.

6 Neues Jahrb., 1852, p. 854.

6 Abhandl. Akad. Miinchen, vol. 11,1871, p. 26.

7 Neues Jahrb., 1894, vol. 1, p. 262. The analyses were made by a number of chemists for Hogbom, 

who gives data for several shells and corals also. In the latter organisms the magnesia was low.

8 Pub. No. Ill, Field Columbian Museum, 1906, p. 31. See also A. H. Clark, Proc. U. S. Nat. Mus., 

vol. 39,1911, p. 487. 

» Op. cit., p. 267.
SEDIMENTARY AND DETEITAL BOCKS. 541

well, and also illustrate the tendency of the magnesium carbonate 

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. Grand] ean l 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 memoir. 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 

MgC03 to. 100 of CaC03 ; and from these figures the ratio was 

gradually raised to 36 MgCO3 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,4 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

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.

* For an elaborate discussion of this side of the dolomite problem see G. Bischof, Lehrbuch der chemfschen 

und physikalischen Geologie, 2d ed., pp. 52-91. The older data are well summarized. See also C. W. Hall 

and F. W. Sardeson, Bull. Geol. Soc. America, vol. 6,1894, p. 189.

* See Dana's Coral and coral islands, 3d ed., p. 393. Analyses by B. Silliman, jr. The island is called 

Metia by Dana.
542 THE DATA OF GEOCHEMISTRY.

experiments of various chemists, as cited in the preceding pages, have 

shown that the indicated reaction can actually take place. Klement's 

experiments, especially, have helped to make this point clear. In a 

coral reef from Porta do Mangue, Brazil, J. C. Branner 1 reports 

6.95 per cent of magnesia, equivalent to 14.5 of carbonate, while the 

corals themselves continued 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 rising to 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

The most striking illustration of this mode of transformation is 

furnished by the borings on the atoll of Funafuti, as discussed by 

J. W. Judd.4 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, feet.

4

13

15

20

26

55

110

159

200

250

Percentage 

MgCO3 .

4.23

7.62

16.4

11.99

16.0

5.85

2.11

0.79

2.7

4.9

Depth, feet.

295

400

500

598

640

698

795

898

1,000

1,114

Percentage 

MgC03 .

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 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

1 Bull. Mus. Comp. Zool., vol. 44,1904, p. 264. Analysis of rock by R. E. Swain, of the corals by L. R. 

Lenox.

a Idem, vol. 42,1903, pp. 53-126.

s See R. Harkness, Quart. Jour. Geol. Soe., rol. 15,1859, p. 103, on dolomite Hear Cork, Ireland. Also 

C. .Doelter and R. Hoernes, Jahrb. K.-k. geol. Reichsanstalt, vol. 25, p. 293. These authors give a bibliography of dolomitization, down to 1875, the date of their memoir.

4 The atoll of Funafuti, published by the Royal Society, London, 1904. For Judd's report on the chemical examination, see pp. 362-389.
SEDIMENTARY AND DETRITAL ROCKS. 543

reef-forming organisms. Some of these are more soluble than others, 

as we have already seen. Algse, especially Liihothamnion and Halimeda, are abundant at Funafuti, and Judd suggests that the abnormally high magnesia found by Hogbom in these organisms may also 

be due to leaching, possibly aided by carbon dioxide derived from the 

decomposition of the plants after death. The replacement of lime by 

magnesia extracted from sea water probably takes place at the same 

time, so that two distinct processes combine to produce the final 

result. It is noticeable that the lower portions of the core, which 

were the earliest deposited and have therefore been acted upon for 

the longest time, are the most completely changed.

In this double process of leaching and replacement, we find the 

nearest approach to a satisfactory theory of dolomitization in coral 

reefs. It is,- however, not general, as the following analyses by 

George Steiger, 1 of borings from an artesian well at Key West,

Florida, clearly show:

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 dolomitization by replacement need 

not be limited to the action of sea water upon coral reefs. Magnesian 

spring waters may be equally effective, and are so locally, as observed 

by J. E. Spurr 2 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.

1 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. 28,189f>, p. 63.

" Mon. U. S. Geol. Survey, vol. 31,1898, p. 206. Spurr (p. 216) also reports an interesting siliciflcation 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 describe^ by J, A. Phillips, Quart. Jour. 

Geol. Soc., vol. 31,1875, p. 324.
544 THE DATA OF GEOCHEMISTKY.

The following analyses of magnesian limestones were made in the 

laboratory of the United States Geological Survey. 1 Other analyses 

in abundance are scattered through the literature of limestones.

Analyses of magnesian limestones.

A. Green Peak Quarry, Dorset, Vermont. Analysis by George Steiger. Described by T. N. Dale in 

Bull. No. 195,1902.

B. ".Knox dolomite," Morrisville, Alabama. Analysis by W. F. Hillebrand. Described by I. C. Russell in Bull. No. 52, 1889.

C. Penokee district, Wisconsin. Analysis by Hillebrand. See R. D. Irving and C. R. Van Hise, in 

Mon., vol. 19,1892.

D. "Niobrara dolomite," Denver Basin, Colorado. Analysis by L. G. Eakins. Described by Emmons, 

in Mon., vol. 27,1896.

E. Near Red Mountain, Silver Peak district, Nevada. Analysis by Steiger.

F. The theoretical composition of ideally pure dolomite.

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

Al O

Fe2 03 --- ---------------------

FpO

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

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

CaO......................"...

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

K2 0. -------------------------

H20.............. ...........

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

(XX. .........................

P D

01............................

A

8.36

1.77

.22

1.08

16.68

29.03

.06

1.08

.03

.42

41.66

100. 39

B

3.24

.17

.17

.06

20.84

29.58

| .30

45.54

99.90

C

0.63

.03

.75

.08

20.68

30.94

| .27

46.27

trace

99.65

D

12.01

.54

.11

.20

18.03

27.49

1 «i j .61

41.40

.03

100. 42

E

0.31

1.89

20.19

30.35

47.21

99.95

F

21.9

30.4

47.7

100.0

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 Dam6ur,2 G. Hauenschild,3 J. Roth,4 and J. Lemberg,5 as a mixture of calcite and brucite, Mg02H2 . 0. Lene6ek,6 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 fay the transformation of its magnesium carbonate into a basic salt or into hydroxide. The latter

1 See Bull. No. 228,1904, pp. 301-335, for these analyses and others.

2 Bull. Soc. gfiol. France, 2d sen, vol. 4,1847, p. 1050.

3 Sitzungsb. Akad. Wien, vol. 60,1870, p. 795.

< See Allgem. chem. Geol., vol. 1, pp. 422-425. Roth cites many analyses of altered dolomites, and gives 

the data concerning predazzite with considerable fullness. 

6 Zeitschr. Deutscli. geol. Gesell., vol. 24,1874, p. 187. 

e Min. pet. Mitt., vol. 12,1892, pp. 429,447. Lenecek gives a good summary of the literature of predazzite.
SEDIMENTARY AND DETBITAL BOCKS. 545

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.1

IRON CARBONATE.

Another important rock-building carbonate is siderite, the ferrous 

carbonate FeC03 . Its formation as bog ore has already been considered,2 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 CaFeC2O6 exists isomorphous with and equivalent to 

the magnesian compound, dolomite. The two salts, CaFeC200 and 

CaMgC2 06 , 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 3 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 

hydroxide was formed. A similar precipitation of limonite was 

observed by G. Keller 4 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,5 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, 6 these ores were

i Arch. Naturkunde Liv., Esth. u. Kurlands, 1st ser., vol. 3,1864, p. 142.

3 See ante, p. 505.

8 Quart. Jour. Geol. Soo., vol. 35, Proc., 1879, p. 73.

< Neues Jahrb., 1882, pt. 1, ref., p. 363.

» Am. Jour. Sci., 3d ser., vol. 42,1891, p. 231.

« Compt. Rend., vol. 100,1885, p. 662.

101381° Bull. 491 11 35
546 THE DATA OF GEOCHEMISTRY.

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,1 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 of iron sinter.

Si02 .......................................................... 1.37

Fe203 ......................................................... 63. 03

AlA......................................................... .08

S03 .......................................................... 8. 35

HoO 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 2 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 being in great 

measure secondary bodies derived from iron carbonates of sedimentary origin. The process by which their concentration was probably 

effected has been summed up by C. R. Van Hise 3 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

1 Am. Geologist, vol. 7,1891, p, 48.

2 Canadian Naturalist, vol. 9,1881, p. 431.

a Twenty-first Ann. Kept. U. S. Geol. Survey, pt. 3, 1900, p. 326. Monographs 19, 28, 36, 43, 45, 

and 46 of the Survey, by Irving, Van Hise. Clements, Smyth, Bayley, and Leith, deal exhaustively with 

these "Lake Superior" ores. See also J. E. Spurr, Bull. No. 10, Geol. Nat. Hist. Survey Minnesota, 1894, 

on the Mesabi ores; and S. Weidman, Bull. No. 13, Wisconsin Geol. Nat. Hist. Survey, 1904, 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 depo'sits.
SEDIMENTARY AND DETRITAL. ROCKS. 547

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 1 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. Hlllebrand. 

B. Iron carbonate, Penokee district, Michigan. Analysis by R. B. Riggs. 

C. Iron carbonate, Gunflint Lake, Canada. Analysis by T. M. Chatard.

D. Ferrodolomite, Marquette district, Michigan. Analysis by G. Steiger. For analyses A, B, C, D, 

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, Neues 

Jahrb., 1892, pt. 2, p. 236.

F. Mangandolomite, Greiner, Tyrol. Analysis by K. Eisenhuth, Zeltschr. Kryst. Mln., vol. 35, 1902, 

p. 582. Other analyses of dolomite, etc., are given in this paper.

Insoluble. ....................

SiOa .........................

TiO

A1 O

FeA-... ...................

FeO............. .............

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

CoO.........................

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

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

H2O-. .......................

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

P O

§&:::::::::::::::::::::::::

QA

A

28.86

.20

1.29

1.01

37.37

.97

.74

3.64

} .68

25.21

99.97

B

15.62

4.27

8.14

32.85

5.06

.81

2.66

. Do

30.32

100. 41

C

23.90

none

.07

.44

10.72

.28

22. 25>

8.52

.99

32.42

.17

99.76

D

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

F

0.16

6.59

23.41

10.48

14.58

45.59

100. 81

SILICATED 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 2 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.3 C. K. Leith,4 however, in his

1 Zeitschr. prakt. Geologie, 1893, p. 301.

2 Ann. Rept. Geol. Survey Arkansas, vol. 1,1892. This is a monograph on the iron ores of Arkansas. 

»Bull. No. 10, Geol. Nat. Hist. Survey Minnesota, 1894. 

«Mon. U. S. Geol. Survey, vol. 43,1903, pp. 237-279.
548 THE DATA OF GEOCHEMISTRY.

report on the Mesabi district, has shown that the green mineral of 

the ferruginous cherts is not glauconite, but a hydrated ferrous or 

ferroso-ferric silicate, containing no potassium. To this silicate he 

gives the name greenalite. Its composition, as shown by the analyses 

made by G. Steiger* 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 2 of a green, massive, chloritic mineral associated with the cronstedtite of Cornwall:

Analyses of greenalite, etc. . t

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

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

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 

silicate, 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 wholly 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 expla1 See C. K. L«ith, Mon. U. S. Geol. Survey, vol. 43,1903, p. 246. Discussion by F. W. Clarke.

2 Phil. Mag., 5th ser., vol. 5,1878, p. 62.
SEDIMENTARY AND DETRITAL HOCKS. 549

nation 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, is represented by the empirical formula 

3Fe().Al203 .2Si02 .3H20. 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. R. 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 allied silicates, were all formed by similar reactions, different 

local conditions having determined which product should appear.0

i Zeitschr. Kryst. Min., vol. 11,1886, p. 601.

»Neues Jahrb., Bell. Bd. 19,1904, p. 40.

' See A. Lacroix, Mindralogie de la France, vol. 1, p. 401, for this and other French occurrences.

* On the ores, locally known as "minette," of Luxemburg and Lorraine, see Bleicher, Bull. Soc. indust. 

de 1'Est, 1894; L. Hoffman, Verhandl. Naturhist. Ver. preuss. Rheinland, etc., vol. 55, 1898, p. 109; H. 

Ansel, Zeitschr. prakt. Oeologle, 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. ,

«Neues Jahrb., Beil. Bd. 19,1904, p. 79. Zalinski gives a good summary of the various theories which 

have been framed hi order to account for these ores.

 In addition to the literature already cited, the following American reports on iron ores are worth 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, Geol. Survey Georgia, 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; Kept, of Progress F, Second Geol. Survey Pennsylvania, 1878, on the ores of the Juniata 

Valley; E. T. Dumble, 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 de fer oolitique de France, by L. Cayeux (Ministere Trav. Publ., Paris, 1909) ia an 

important recent monograph.
550 THE DATA OF GEOCHEMISTRY.

GYPSUM.

The occurrence of gypsum as a sedimentary rock has already been 

partially considered.1 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,2 or derived from the oxidation of pyrite, by acting upon 

limestones, also produc.e 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,3 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. 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.4

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 5 

2H2S + 02 = 2H20 + 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 H20 + S develops only 

59,100 calories. Hence, where oxygen is in excess, as at the surface, 

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 6 to solfataric activity.

« See ante, pp. 211-220.

* J. W. Dawson (Acadian geology, 1891, p. 262) attributes the formation of gypsum in Nova Scotia to 

the action of sulphuric acid, derived from volcanic sources, on limestones.

s Annales Soc. ge"ol. Belgique, vol. 23,1896, p. cxxvii.

4 Fordata upon American gypsum see G. P. Qrimsley, Geol. Survey Michigan, vol. 9, pt. 2,1904; Grimsley 

and E. H. S. Bailey, Univ. Geol. Survey Kansas, vol. 5,1899; C. R. Keyes, Iowa Geol. 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.

& See G. F. Becker, Mon. U. S. Geol. Survey, vol. 13,1888, p. 254; and J. Habennann, Zeitschr. anorg. 

Chemie, vol. 38,1904, p. 101.

« Bull. U. S. Geol. Survey No. 225,1904, p. 497.
SEDIMENTARY AND DETEITAL BOOKS. 551

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. 1 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 vol-. 

canic 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 solfataras, 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.2 A. von Lasaulx,3 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 4 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 

A. Be'champ,5 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,6 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

i See especially E. Plauchud, Compt. Rend., vol. 84,1877, p. 235; vol. 95,1882, p. 1363. Also A. Etard 

and L. Olivier, idem, vol. 95,1882, p. 846.

8 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.

a Neues Jahrb., 1879, p. 490.

< Sull' origine del solfo nei giacimenti solflferi della Sicilia, Torino, 1892. The theories relative to the 

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.

6 Annales chim. phys., 4th ser., vol. 16,1869, p. 234.

0 Op. cit., p. 119.
552 THE DATA of GEOCHEMISTRY.

gypsum is likely to be formed. 1 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 2 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 3 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.4 It is derived0 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.

CELESTITE.

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,5 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 6 has also reported celestite as extensively dissemi1 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. "

2 Bull. Geol. Inst. Upsala, vol. 1, No. 2,1893. A similar inclusion was earlier described by O. Silvestri, 

Gazz. cblm. ital., vol. 12,1882, p. 9.

a Univ. Texas Mineral Survey, Bull. No. 2,1902. See also G. B. Richardson, idem, Bull. No. 9,1904, 

p. 68. The sulphur deposits of Louisiana are described by L. Baldacci, II giacimento solfifero della Louisiana, Rome, 1906.

4 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, Bd. 1, p. 259.

& Am. Jour. Sci., 4th ser., vol. 21,1906, p. 237. See also W. H. Sherzer, idem, 3d ser., vol. 50,1895, p. 246; 

and Geol. Survey Michigan, vol. 7, pt. 1,1900, p. 208.

8 Am. Jour. Sci., 4th ser., vol. 18,1904, p. 30.
SEDIMENTARY AND DETRlTAL BOOKS. 553

nated 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.1 

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,2 celestite and barite 

occur together in bituminous limestone. H. Bauerman and C. Le 

Neve Foster 3 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.4 Examples of this kind might

be multiplied almost indefinitely. Strontium and calcium are so

nearly related chemically that their common association in rocks is 

something to be naturally expected.

BARITE.

Barite, the barium sulphate, BaS04 , is closely akin mineralogically 

to celestite, but is more characteristically found in metalliferous veins 

than in bedded formations.5 Its occurrence as a cement in sandstones 

has already been noticed,6 and it has also been observed as a sintery 

or even stalactitic deposit from spring and mine waters.7

P. P. Bedson 8 found barium to be present in notable amounts in 

an English colliery water; and T. Richardson 9 has described a 

deposit of barite from a similar solution. Like deposits from other 

English collieries have been reported by F. Clowes, 10 who analyzed 

samples containing from 81.37 to 93.35 per cent of BaS04 . 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, 11 large masses 

of sinter have formed, consisting at some points of nearly pure 

barium sulphate, which at other points is mixed with minor to domi1 Kraus, Am. Jour. Sci., 4th set., vol. 19,1905, p. 286.

»Min. pet. Mitt., vol. 9,1888, p. 416.

8 Quart. Jour. Geol. Soc., vol. 25,1869, p. 40.

«Annales des mines, 7th ser., vol. 20,1881, p. 557.

6 See L. Dieulafait, Compt. Kend., vol. 97,1883, p. 51.

6 See ante, p. 515.

' For the distribution of barium in waters, etc., see R. Delkeskamp, Notizbl. Ver. Erdkunde, 4th ser., 

Heft 21,1900, pp. 47-83. On the distribution of barium and strontium in sedimentary rocks, see L. Collot, 

Compt. Rend., vol. 141,1905, p. 832.

s Jour. Soc. Chem. Ind., vol. 6,1887, p. 712.

» Rept. Brit. Assoc., 1863, p. 54.

w Proc. Roy. Soc., vol. 46,1889, p. 368. 

»i Proc. Colorado Sci. Soc., vol. 8,1905, p. 1.
554 THE DATA OF GEOCHEMISTRY.

nant quantities of calcium carbonate. Barytic 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.1 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:

Analyses of spring and mine waters at Lautenthal.

BaCl2 . ..................................................

SrCl,. ..................................................

CaCl2 ...................................................

MgCl2 ....................................... ............

NaCl. .................................................

KC1....................................................

Mg804 .............. ....................................

ZnS04 . .................................................

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.2

Barium and strontium sulphates in deposits at Lautenthal.

BaSO

SrSO 4

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 calcium sulphate 

is often present also. A remarkable banded barite, from Pettis 

County, Missouri, described by C. Luedeking and H. A. Wheeler, 3 

had the following composition:

Analysis of barite from Pettis County, Missouri.

BaSO

SrS04 . ..............................

CaS04 ..... ...........................

(NH4)2S04 ....... ....... ....... .......

H20..................................

......................... 87. 2

......................... 10. 9

......................... .2

......................... .2

................... ..... 2.4

100.9

1 Jahrb. K. preuss. geol. Landesanstalt, 1888, p. 259. A similar deposit of barium and strontium sulphates 

from an English mine water is described by J. T. Dunn, Chem. News, vol. 35,1877, p. 140.

2 Complete analyses are given in the original memoir by Lattermann.

s Am. Jour. Sci., 3d set., vol. 42,1891, p. 495. The presence of ammonium salts was independently verified 

by tests in the laboratory of the United States Geological Survey.
SEDIMENTARY AND DETRITAL ROCKS. 555

The presence of an ammonium salt in such a mineral is most

unusual. \

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 * 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; and 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 2 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.3

Various syntheses of crystalline barite are on record. One of the 

latest by Hilda Gebhart,4 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.

FLUORITE.

Fluorite or fluorspar, calcium fluoride, CaF2 , is also a common 

mineral in dolomites and limestones,5 and it is often associated with 

galena and zinc blende. Crystals of it are found in limestone geodes,

1 School of Mines Quart., vol. 23,1902, p. 366.

a Rec. Geol. Survey India, vol. 30,1897, p. 236.

s On the genesis of barite see an important paper by G. B. Trener, Jahrb. K.-k. geol. Reichsanstalt, vol. 

53,1908, 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.

* Min. pet. Mitt, vol. 29, 1910, p. 185.

6 See ante, p. 318, for an account of fluorite as a rock-forming mineral. Also p. 515 for fluorite as a cement 

in sandstones. For an exhaustive memoir on fluorite in sediments see K. Andr6e, Min. pet. Mitt., vol. 

28,1909, p. 685.
556 THE DATA OP GEOCHEMISTBY.

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. 1

i For a description of the great fluorspar deposits in Kentucky and southern Illinois see S. F. Emmons, 

Trans. Am. Inst. Min. Eng., vol. 21,1893, p. 31; H. F. Bain, Bull. U. S. Geol. Survey No. 255,1905; E. O. 

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. 

Geologic, 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.

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 ah1 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 uralitization, 

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 quartz.

557
558 TEE DATA OF GEOCHEMISTRY.

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 cases 

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." This process generates new minerals within 

a rock, and introduces like solutions, 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 convenince, but its application to concrete 

examples of metamorphism 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 metamorphism. The 

ideal simplicity is not often found.

In the study of metamorphic phenomena the conceptions developed 

by C. R. Van Hise 1 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 belts 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 reconsolidation of sedimentary material. It is, in short,

'A treatise on metamorphiam: Mon. U. 8. GeoL Survey, vol. 47t 1904.
METAMORPHIC ROCKS. . 559

the birthplace of such rocks as shales and sandstones. In the belt 

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 waterUnder 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 examples, typical minerals of the metamorphic rocks.

According to C. E. 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 of 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 then- 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 katamorphism, 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 suboapillary and
560 THE DATA OF GEOCHEMISTRY.

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 was 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 

be 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.

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 

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

i See ante, p. 283.
METAMOEPHIC BOOKS. 561

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.

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

i See ante, pp. 260 et seq., for the experiments of Tilden, Travers, Gautier, etc. 

J01381 0 Bull. 491 11 36
562 THE DATA OF GEOCHEMISTRY.

from an igneous rock or from one of sedimentary origin, the product 

being sensibly the same in both cases. Is 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; secondthose 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 

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 ;3

i U. Grubenmann (Die Kristallinen Schiefer, Berlin, vol. 1,1904; vol. 2, 1907) has attempted to form a 

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 axe to the 

first edition.

a Neues Jahrb., 1896, pt. 2, p. 182.

s Die Kristallinen Schiefer, Berlin, 1904, pp. 34-38. Grubenmann's data are taken from a paper by 

F. Becke, in Compt. rend. IX. Gong. geol. internat, 1903, p. 553. See also F. Loewinson-Lessing, Studien 

iiber die Eruptivgesteine: Compt. rend. VII. Gong. geol. internat., St. Petersburg, 1897.
METAMOEPHIC KOCKS. 563

and although the calculations are necessarily crude, they are none 

the less conclusive. 1 The fact that there 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 plagioclase.

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.

TJKALITIZATION.

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.2 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 3 in a dike at Scourie, Sutherlandshire, 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.

1 For a tabulation of the volume changes attending the alteration of minerals, see C. R. Van Hise, A 

treatise on metamorphism: Mon. U. S. Geol. Survey, vol. 47,1904, pp. 397-408.

a 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. 139,1904, p. 223, on a theory of uralitization.

»British petrography, 1888, p. 198; also in Quart. Jour. Geol. Soc., vol. 41,1885, p. 137,
564 THE DATA OF GEOCHEMISTRY.

Analyses of pyroxene rocks before and after alteration.

Aa. The plagioclase-pyroxene rock of the Scourie dike.

Ab. The derived hornblende schist. Analyses by Teall, loc cit.

Ba. Pyroxene from the center of a crystal, Templeton, Canada.

Bb. Intermediate portion of the same crystal.

Be. Hornblende forming the rim of the crystal. Analyses B by B. J. Harrington, Geol. Survey Canada, 

Rec. of Progress, 1877-78, p. 21 G.

Ca. Diallage from a gabbro, Transvaal, South Africa.

Cb. Uralite from alteration of the diallage. Analyses C by P. Dahms, Neues Jahrb., Beil. Bd. 7, p. 99, 

1891.

Si02 ... .......... ............. Ai2 o3 .....................:...

Fea03 . ......................

FeO..... ............ ........

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

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

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

NazO........... ................

K-0... ......................

HoO. ........................

TiOa ............. :..........

C0a .........................

Aa.

47.45

14.83

2.47

14.71

5.00

8.87

2.97

.99

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

o 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

1 See G. Rose, Zeitschr. 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. 

a On amphibolite produced by the intrusion of granite into limestone, in the Laurentian rocks of Canada, 

see F. D. Adams, Jour. Geology, vol. 17,1909, p. 1.
ME.TAMOEPHIC BOCKS. 565 

GLAUCOPHANE SCHISTS.

The glaucophane schists differ from the amphibolites in that they 

contain the soda amphibole instead of hornblende. H. S. Washington * divides these rocks into three classes, namely, epidote-glaucophane schist, mica-glaucophane schist, and quartz-glaucophane 

schist; but he also recognizes the fact that there are many transitional 

varieties. W. H. Melville,2 for example, has described a garnetglaucophane schist from Mount Diablo, California; and A. Wichmann 3 an epidote-mica-glaucophane schist from Celebes. A zoisiteglaucophane schist from Sulphur Bank, California, is also mentioned 

by G. F. Becker.4 It consists chiefly of glaucophane and zoisite, but 

quartz, albite, sphene, 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.

Genetically, the glaucophane rocks differ widely. Some of them 

are undoubtedly derived from medibsilicic 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 amphibolite, 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 these rocks is obscure; but Washington suggests that the epidote-glaucophane schists represent originally gabbroid magmas, while the quartz-glaucophane schists are metamorphosed quartzites or quartzose shales. For convenience, differences

1 Am. Jour. Sci., 4th ser., vol. 11,1901, p. 35. This memoir is a very complete summary of our knowledge 

of these rocks. It contains many analyses, and abundant references to literature. See also K. Oebbeke, 

Zeitschr. Deutsch. geol. Gesell., vol. 38, 1886, p. 634; U. Grubenmann, Eosenbusch "Festschrift," 1900; 

E. H. Nutter and W. B. Barber, Jour. Geology, vol. 10, 1902, p. 738; and J. P. Smith, Proc. Am. Philos. 

Soc., vol. 45,1906, p. 183. The last two papers relate to the glaucophane rocks of California. Other note, 

worthy papers are by E. Murgoci, Bull. Dept. Geology Univ. California, vol. 4,1906, p. 359; and L. Milch, 

Neues Jahrb., Festband, 1907, p. 348.

» Bull. Geol. Soc. America, vol. 2,1890, p. 413.

a Neues Jahrb., 1893, pt. 2, p. 176.

«Mon. U. S. Geol. Survey, vol. 13,1888, p. 104.

6 Mineralog. Mag., vol. 7,1S87, p. 1.

o Geologie von Attika, Berlin, 1893, pp. 102,133.

i Geol. Mag., 1888, p. 125.

» Bol. Com. geol. ital., vol. 26,1895, p. 192.

 Jour. Coll. Sci. Japan, vol. 1,1886, p. 85.

10 Bull. Dept. Geology Univ. California, vol. 1, p. 211.
566 THE DATA OF GEOCHEMISTRY.

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.0

A. Amphibolite dike, Palmer Center, Massachusetts.

B. Amphibolite bed, Palmer Center. Analyses A and B by W. F. Hillebrand, Bull. U. S. Geol. Survey 

No. 228,1904, p. 36.

C. Amphibolite, Crystal Falls district, Michigan. Described by H. L. Smyth, Mon. U. S. Geol. Survey, 

vol. 36,1899, p. 397. Analysis by H. N. Stokes. Probably derived from a diabase or basalt. Contains 

hornblende, plagioclase, biotite, and quartz, with a little rutile and magnetite.

D. Epidote-glaucophane schist, Mount Diablo, California. Analysis by W. H. Melville, Bull. Geol. Soc. 

America, vol. 2,1890, p. 413. Contains garnets. Possibly derived from shale.

E. Garnet-glaucophane schist, Bandon, Oregon. Analyzed and described by H. S. Washington, Am. 

 Jour. Sci., 4th ser., vol. 11,1901, p. 35. Contains glaucophanej epidote or zoisite, garnet, and white mica.

F. Zoisite-glaucophane schist, Sulphur Bank, California. Analysis by Melville. Described by G. F. 

Becker, Mon. U. S. Geol. Survey, vol. 13,1888, p. 104.

G. Mica-glaucophane schist, Island of Syra, Greece. Analyzed and described by Washington, loc. cit.

H. Quartz-glaucophane schist, Fourmile Creek, Coos County, Oregon. Analyzed and described by 

Washington. Contains quartz, glaucophane, chlorite, muscovite, and garnet.

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

Al O

FeA........ ........

FeO...................

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

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

NaaO..... ............

K-0.. .................

H20..................

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

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

C02 ............. ......

p fi

s......................

V203 .. ...............

Gifis.. ................

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

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

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

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

Li20..... .............

A

49.57

14.23

3.95

8.01

6.14

10.19

3.06

.95

.14

1.33

2.03

.21

.02

.04

trace

trace

?,1

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

.31

( P

undet.

trace

.28

(?)

(?)

trace?

100. 46

1C

50.36

13.26

6.30

9.34

5.55

7.85

2.11

1.14

1.55

1.55

1.77

.20

tTOPO

99.59

D

47.84

16.88

4.99

5.56

7.89

11.15

3.20

.46

.17

1.81

.14

Kft

100. 65

E

49.15

15.87

4.10

7.58

7.53

9.06

3.59

.54

.16

1.07

1.19

^"FQ/">O

99.84

F

49.68

13.60

1.86

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

4-vn /-»A

99.67

H

82.53

6.88

.59

4.11

1.86

.68

1.21

1.24

.07

1.35

"f T*Q f*Q

100. 52

a. A number of amphibolites from Massachusetts are described by B. K. Emerson in Mon. U. S. Geol. Survey, vol. 29, 1898. For analyses see also Bull. 419,1910, pp. 19-21. These amphibolites are regarded as 

derived from argillaceous limestones. L. Hezner (Min. pet. Mitt., vol. 22,1903, p. 505) gives several analyses 

of amphibolites from the Tyrol. See also a table of analyses in Rosenbusch, Elemente der Gosteinslehre, 

p. 532. See also, on amphibolite, F. Becke, Min. pet. Mitt., vol. 4, 1882, p. 285; and J. A. Ippen, Mitth. 

Naturwiss. Ver. Steiermark, 1892, p. 328. Ippen describes "normal amphibolite," and also zoisite, pyroxene, feldspar, and garnet amphibolite.

SERICITIZATION.

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
ME.TAMOBPHIC BOOKS. 567

ha,ve proved in most cases to be not talcose, but sericitic. 1 The identity of sericite with muscovite was :finally established by H. Laspeyres2 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 1 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 + 2A1O.OH = KH2Al3Si3012 .

This reaction is very simple chemically, but geologically improbable. 

It requires the presence of solutions containing much alumina, and it 

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 investigation.

A second, more probable, and even simpler reaction is the following:

3KAlSi3O8 + H2O = KH2Al3Si3 012 + K2Si03 + 5Si02 .

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,

i See G. H. Williams, Bull. U. S. Geol. Survey No. 62,1890, pp. 60-62, for historical details.

* Zeitschr. Kryst. Min., vol. 4,1879, p. 245.

8 See J. G. Lehmann, Untersuchungen uber die Entstehung der altkrystallinischen Schiefergesteine, Bonn, 

1884; A. Wichmann, Verhandl. Natur. Ver. preuss. Rheinl. u. Westfalens, vol. 34,1877, p. 1; A. von Groddeck, Neues Jahrb., Beil. Bd. 2,1883. p. 72; C. Schmidt, idem, Beil. Bd. 4, 1886, p. 428, and C. Benedicks, 

Bull. Geol. Inst. 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.
568 THE DATA OF GEOCHEMISTRY.

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:

3KAlSi3 08 + H2O + C02 = KH2Al3Si3 012 4- 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.

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. 2 When the lime of the anorthite is not completely 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

1 Compare W. Lindgren, Trans. Am. Inst. Min. Eng., vol. 30,1900, p. 608, in reference to the association 

with calcite.

2 See K. A. Lossen, Jahrb. K. preuss. geol. Landesanstalt, 1884, pp. 525-530. See also G. H. Williams, 

Bull. U. S. Geol. Survey No. 62,1890, p. 60.
METAMORPHIC ROCKS. 569

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:

NaAlSi308 + 4CaAl2Si208 + 2H2 0 = 

Albite. Anorthite. Water.

2Ca2HAl3Si3013 + H2NaAl3Si3012 + 2Si02 . 

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 pa'sses 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 

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.

i Zeitschr. Kryst. Min., vol. 10,1885, p. 444. 

a Min. pet. Mitt., vol. 1,1878, p. 247. 

s Neues Jahrb., 1881, pt. 1, p. 32.

* Bull. U. S. Geol. Survey No. 62,1890, pp. 67-76. Another saussuritized gabbro from the Upper Quinnesec Falls is described on pp. 102-104. On pp. 58-60 Williams gives a general discussion of this form of 

alteration, with historical details. See also A. Cathrein, Zeitschr. Kryst. Min., vol. 7,1883, p. 234.

* Bradshaw Mountains folio (No. 126), Geol. Atlas U. S., U. S. Geol. Survey, 1905, pp. 4-6.
570 THE DATA OF GEOCHEMISTRY.

Analyses ofzoisite rocks.

A. Sturgeon Falls gabbro, freshest form.

B. The same, altered form.

C. Silvery schist derived from Sturgeon Falls gabbro. Analyses A, B, and C by R. B. Riggs.

D. Zoisite-hornblende diorite, Bradshaw Mountains. Analysis by George Steiger.

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

A1203 ----- ----- ..............................

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

FeO........... ..... ..........................

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

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

Na2O..... ....... ...........................

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

H2O.............. .................... .......

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

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

CO,.... .......................................

p n

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

9 F>4

1.94

} 7.53

.93

100. 28

C

45.70

16.53

4.63

3.89

9.57

4.28

.55

3.82

1 4.70

5.95

99.62

D

45.73

1Q 45

5.28

3.18

fi 94

13.86

.64

.32

1.57

3.5690

.28

100. 34

The sericitization of C is shown by the loss of sodium and 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 

the original rock. It must be noted, however, 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.

1 Bull. Soc. min., vol. 2,1879, p. 113.

2 Min. Mag., vol. 8, 1889, p. 186. See also A. Michel Levy, Bull. Soc. min., vol. 1,1878, pp. 43, 78. A 

similar rock from Bamle, Norway, containing sphene, amphibole, and wernerite, is also described. Other 

noteworthy memoirs on the Scandinavian rocks of this class are by A. E. Tornebohm and E. Svedmark, 

Geol. Foren. Forhandl., vol. 6,1882, p. 192; vol. 7,1884, p. 293.
METAMORKEIC BOOKS. 5Yl

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, Ca4Al0Si0025; and 

marialite, Na4Al3Si0 024Cl. These may be derived from anorthite 

and albite in accordance with the following empirical equations:

3CaAl2Si208 + CaO = Ca4Al6Si 8025 . 

3NaAlSi308 + NaCl = Na4Al3Si9024Cl

In order to change an ordinary plagioclase into an ordinary scapolite, 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 saussuritization, 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 

parent. In the rocks of Leadville, W. Cross 5 found epidote derived 

from orthoclase, plagioclase, biotite, and hornblende. G. H. Williams ° observed its formation as a contact rim between feldspar and

1 See the section on scapolite in Chapter X, p. 383, ante.

2 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 wernerite pyroxenite. Wernerite, 

It will be remembered, is one of the intermediate scapolites. See also H. Wulf, Min. pet. Mitt., vol. 8,1887, 

p. 213, on a scapolite-augite gneiss from Herero Land, Africa; and F. Becke, idem, vol. 4, 1882, p. 285, on 

similar rocks from Lower Austria. Scapolite amphibolites are described by O. Mtigge, Neues Jahrb., Beil. 

Bd. 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. Kept. 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, hornblende, feldspar, 

and scapolite.

' See A. Cathrein, Zeitschr. Kryst. Min., vol. 7,1883, p. 247; A. Schenck, Verhandl. Naturhist. Ver. preuss. 

Rheinl. 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. Rosenbusch, Neues Jahrb., 3884, pt. 2, Ref., p. 189.

6 Moa. U. S. Geol. Survey, vol. 12,1886, pp. 34], 357.

8 Bull. U. S. Geol. Survey No. 28,1886, p. 31.
572 THE DATA OF GEOCHEMISTRY.

hornblende in the gabbro-diorite near Baltimore, and F. D. Chester * 

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 2 describes an alteration of this kind from augite porphyry; 

and Schenck 3 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 4 from western 

North Carolina. It has since been found near Milam's Gap, Virginia. 

According to W. C. Phalen,5 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. 6 Here, as at Milam's 

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.7

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.8 According to J. A. Ippen, 9 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. 

the mixture. The eclogites of the lower Loire, according to Al 

Lacroix, 10 sometimes contain feldspar formed as a secondary minera 

during the uralitization of highly aluminous pyroxenes. Lacroix 

shows that these rocks are products of dynamometamorphism. The

i Bull. U. S. Geol. Survey No. 59,1890, p. 35.

* Zeitschr. Deutsch. geol. Gesell., vol. 29,1877, p. 498.

s Verhandl. Naturhist. Ver. preuss. Rheinl. u. Westfalens, vol. 41, 1884, p. 53.

< Am. Jour. Sci., 3d ser., vol. 7,1874, p. 519.

5 Misc. Coll. Smithsonian Inst., Quart. Issue, vol. 1,1904, p. 301.

«Ann. Rept. State Geologist New Jersey, 1895, p. 30.

' See ZirkeFs 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.

8 See R. von Drasche, Jahrb. K.-k. geol. Reichsanstalt, 1871, Min. Mitt., p. 85, and E. R. Riess, Min. pet. 

Mitt., vol. 1,1878, pp. 165, 181.

8 Mitt. Naturwiss. Ver. Steiermark, 1892, p. 328.

10 Bull. Soc. sci. nat. de 1'Ouest de la France, vol. 1,1891, p. 81.
METAMOBPHIC KOCKS. 573

crushing and fracturing of the original rocks has facilitated the circulation of the waters to which their alterations are due.

L. Hezner,1 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 ecogite 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. Epldoslte derived from diabase, upper Buhrthal, Germany. 

C. Unakite, Milam's Gap, Virginia. Analysis by Phalen. 

D. Eclogite, Sulzthal, Styria. 

E. Eclogite, Burgstein, Styria. Analyses D and E by Hezner.

Analyzed and described by Schenck.

SiOa . ................................

AI o

FeA. ..............................

FeO............ ......................

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

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

Na.0. ............... .I.... ..........

K26. ................................

H20-......................"..........

H?0+. ..............................

Ti02 - ................................

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

P O

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

FeS2 ......................... ........

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

.26

100. 59

C

58.32

15.77

6.56

.89

.09

11. 68

.32

4.01

} 1.73

(a).

.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

11.99

11.66

2.45

1.51

1.10

.28

99.93

o Not separated from alumina. 

CHLOBITIZATION.

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

i Min. pet. Mitt., vol. 22,1903, pp. 437,505. See also E. Joukowsky, Compt. Rend., vol. 133,1901, p. 1312, 

on alterations of eclogite from Lac Corau. Other valuable papers upon eclogite are by P. Lohmann, Neues 

Jahrb., 1884, pt. 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. Phjlos, 

Spc., vol. 45,1906, p. 183.
574 THE DATA OF GEOCHEMISTRY.

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 

chloride schist. Diabase and diorite are often chloritized, gaining 

thereby the green color to which the common appellation "greenstone" is due. In diabase the chloritic 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 emphasizes 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 "chloritic substance" 

in 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. Gtimbel.

CONSTITUTIONAL FORMULAE.

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 formulsB of several minerals. 

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 formulas of orthoclase and 

albite, which are suggested by the alteration of albite into marialite, 

the following system of formulae can be developed: 3

Orthoclase......................................Al3 (Si3 08 )3K3.

Albite......................................... Al3 (Si308)3Na3 .

Marialite....................................... Al2(Si3 08 )3Na4(AlCl).

Nephelite....................................... Al3(Si04 )3Na3 .

Paragonite..................................... 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 .

Prehnite....................................... Al2 (Si04 )3Ca2H2 .

Zoisite........................................... Al2(Si04 )3Ca.,(A10H).

i Bull. U. S. Geol. Survey No. 62,1890.

«See G. W. Hawes, Am. Jour. Sci., 3d ser., vol. 9,1875, pp. 190,454. Also A. Schenck, Verhandl. Naturhist. Ver. preuss. Rheinl. u. Westfalens, vol. 41,1884, p. 74. Chloritization is fully discussed by Rosenbusch 

in his Mikroskopische Physiographic der massigen Gesteine, 2d ed., vol. 2, pp. 180-184.

»See F. W. Clarke, Bull. U. S. Geol. Survey No. 125,1895, for an extended discussion pf these formulae.
METAMOEPHIC BOOKS. 575

Epidote resembles zoisite, but with iron partly replacing aluminum, 

and similar replacements exist in the garnet group. Anorthite, 

meionite, and the normal chlorites are representable by formulae of 

the same type, but slightly more complex, and many other aluminosilicates follow the same rule.

From these formulae, which are identical in type, the observed alterations become intelligible. One species changes into another by 

replacement 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 described.

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 + 2H20+C02 - Mg3H4Si209 +MgC03 . 

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.

1 According to G. 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 F. Sandberger, Neues Jahrb., 1866, p. 385; idem, 1867, p. 176; G. Tschermak, Sitzungsb. Akad. 

Wien, vol. 56,1867, p. 261; E. Weinschenk, Abhandl. K.-bayer. Akad., Math.-phys. Klasse, vol. 18, p. 651; 

J. Lemberg, Zeitschr. Deutsch. geol. Gesel]., 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.

« Quart. Jour. Geol. Soc., vol. 33,1877, p. 884.
576 THE DATA OF GEOCHEMISTRY.

Pyroxenes, also, are often converted into serpentine. The equation, in the case of diopside, is perhaps as follows:

3MgCaSi206 + 3C02 + 2H20 =Mg3H4Si209 + 3CaC03 + 4Si02 . 

Diopside. Serpentine. Calcite. Quartz.

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 is 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, amphibole, 

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 muscovite 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 Westchester County, 

New York, according to J. D. Dana, 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 ophiolite or ophicalcite of 

Warren County, New York. 9 The "verde-antique" marbles are

1 B. K. Emerson (Mon. U. S. Geol. Survey, vol. 29,1898, p. 114) assigns this origin to the serpentines of the 

Connecticut Valley. An Australian amphibolite serpentine has also been described by J. B. Jaquet, Rec. 

Geol. Survey New South Wales, vol. 5,1896-1898, p. 21.

a See A. Schrauf, Zeitschr. Kryst. Min., vol. 6,1S82, p. 321.

a See J. D. Dana, Am. Jour. Sci., 3d ser., vol. 8,1874, p. 371, on serpentine pseudomorphs from the Tilly 

Foster mine.

< See G. F. Becker, Mon. U. S. Geol. Survey, vol. 13,1888, pp. 108-128.

B Zeitschr. Deutsch. geol. Gesell., vol. 22,1870, p. 345; vol. 24,1872, p. 255.

«Am. Jour. Sci., 3d ser., vol. 20,1880, p. 30.

* Mon. U. S. Geol. Survey, vol. 12,1886, p. 282. 

s Proc. U. S. Nat. Mus., vol. 11,1888, p. 105.

 Am. Jour. Sci.; 3d ser., vol. 20,1880, p. 30.
METAMOEPHIC KOCKS. 577

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. 1 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 2 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.3 The 

acids of volcanic fumaroles had removed the bases of the serpentine 

iii 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.4 L. Dieulafait 5 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.

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 quartz, water 

being eliminated in both cases. These decompositions may be 

written thus:

Mg3H4Si2O9 = Mg2Si04 + MgSi03 + 2H2O. 

Mg3H2SiA2 = 3MgSiO3 + Si02 + H2O.

Talc, like serpentine, may originate in different ways; but its commonest derivation seems to be by the alteration of amphiboles or

i Bull. U. S. Geol. Survey No. 262,1905, p. 69. 

3 Mon. U. S. Geol. Survey, vol. 13, 1888, p. 127.

3 Compt. Rend., vol. 124, 1887, p. 513.

4 Mineral physiology and physiography, 1886, pp. 434-516. Hunt cites a large amount of evidence from 

Italian sources. 

. 6 Compt. Rend., vol. 91,1880, p. 1000.

101381° Bull. 491 11 37
578 THE DATA OF GEOCHEMISTRY.

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:

4MgSi03 + H20+C02 =Mg3H2Si4012 +MgC03 .

Mg3CaSi4O12 + H20+C02 =Mg3H2Si4O12 + CaC03 .

These reactions are much alike, and resemble those which are recognized in tfye 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 ma}r 

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. EL 

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.

The following analyses represent talcose and serpentinous rocks 

of varied characters.

1 School of Mines Qyart., vol. 17,1896, p. 333.

a North Carolina Geol. Survey, Econ. Paper No. 3,1900.

aSitzungsb. Niederrhein. Gesell., Bonu, 1865, p. 126.

< Jour. Geology, vol. 4,1896, p. 58.

6 Zeitschr. prakt. Geologic, 1908, p. 145.

« E. Weinschenk, Zeitschr. Kryst. Min., vol. 14,1888, p. 305.
ME.TAMORPHIC BOOKS. 579

Analyses of talcose and serpentinous rocks.

A. Dark-green serpentine, Rowe, Massachusetts. Described by B. K. Emerson in Mon. U. S. Geol. 

Survey, vol. 29,1898. Analysis by G. Steiger.

B. Serpentine, Greenville, California. Described by J. S. Diller in Bull. U. S. Geol. Survey No. 150, 

1898, 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. Bonney (Geol. Mag., 1897, p. 

110) as a stage in the alteration of serpentine. The original rock was perhaps a basalt or dolerite. Analysis 

by Emily Aston.

G. Brucite serpentine, Stevens 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., 1887, pt. l,p. 119. 

Analysis by Van Riesen.

SiOa ..................

A1208 -- - - --

Fe203 ---- -------------

FeO...................

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

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

Na20.................

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

HaO-..... ......

HaO+..... ............

TiO

C0a ............ .......

P O

fv n

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

CoO...... ............

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

S08 ..................

FeSa .................

A

40.42

1.86

2.75

4.27

35.95

.66

}

1 d .1U

.21

10.51

1.44

.28

.53

trace

.43

99.47

B

39.14

2.08

4.27

2.04

39.84

Il2. 70

.11

100. 18

C

41.86

.09

4.15

38.63

}l4: 16

.24

.20

99.93

D

40.50

.78

4.01

2.04

37.43

.39

.28

.16

2.81

10.94

.41

.11

.13

99.99

E

30.98

1.04

4.88

2.01

38.44

.22

.40

.16

.39

20.43

.34

.42

.44

100. 15

F

44.94

5.47

1.75

3.47

25.57

8.76

.35

5.40

1.22

2,90

trace

99.83

G

13.08

1.63

1.25

.19

56.44

.33

none

none

.85

23.94

2.03

99.74

H

63.29

1.24

.16

4.68

27.13

J 4.40

100. 90

The presence of chromium and nickel in several of these rocks is a 

good indication of a relationship with the pyroxenites 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, usuaUy more or 

less weathered, and these undergo the normal changes. Feldspar 

becomes sericite, hornblende alters to chlorite, and so on, exactly as
580 THE DATA OF GEOCHEMISTRY.

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 series 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 feldspathic 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, see C. R. Van Hise, A treatise on metamorphism: Mon. U. S. Geol. Survey, vol. 47,1904, pp. 865-880. See also R. 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 BOOKS. 581

Analyses of quartzite and quartz schist.

A. Dark vitreous quartzite, Pigeon Point, Minnesota. Contains quartz, with a little feldspar, chlorite, 

mica, and magnetite. Described by W. S. Bayley, Bull. U. S. Geol. 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. Geol. Survey No. 

136,1896. Analysis by F. A. Genth, on p. 34.

D. Quartz schist, near Stevenson station, Maryland. Contains quartz, muscovite, tourmaline, microcline, zircon, and iron stains. Described by Bayley, Bull. U. S. Geol. Survey No. 150,1898, p. 302. Analysis by E. A. Schneider.

SiOa .. ........................................

Al O

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

Feb..:........................................

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

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

Na20.........................................

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

HaO... ........................................

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

P O

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

A

74.22

10.61

7.45

.85

1.48

.56

2.12

1.08

61.79

.16

100. 32

B'

83.69

7.50

1.81

.38

.35

.39

2.46

2.61

.72

trace?

99.91

c

a 92. 00

4.21

1.80

.04

.16

. 1.16

b.96

.14

.21

100. 68

D

91.65

1.59

3.57

.21

.17

none

.07

1.93

.60

.13

tfflPA

99.92

a 84.13 per cent quartz, 7.87 per cent combined silica. 6 Loss on ignition.

METAMORPHOSED SHALES.

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 metamorphic 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

1 If a bed of limonite be regarded as a sedimentary rock, a bed of hematite may be its metarnorphic 

equivalent.
582 THE 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 kiind, containing hematite, 

magnetite, and quartz.1 Similar rocks have been described by H.

Coquand 2 in France, and 0. M. Lieber 3 

quand's rock is described as equivalent to

in South Carolina. Coa 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. Lossen ° 

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 Hise,7 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 caUs 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:

 i See Zirkel, Lehrbuch der Petrographie, 2d ed., p. 570, for references,

2 Bull. Soc. g<5ol. France, 2d ser., vol. 6,1849, p. 291.

3 Eept. Survey South Carolina, 1855, pp. 89-94; 1857, p. 79; 1858, p. 107.

4 Verhandl. K.-k. geol. Reichsanstalt, 1878, p. 168.

6 Sitzungsb. Akad. 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.

i A treatise on metamorphism: Mon. U. S. Geol. Survey, vol. 47,1904, pp. 830-842. See also the literature 

there cited, 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 E. Arnold and R. Anderson, Jour. Geology, vol. 15,1907, p. 750.
MB.TAMOEPHIC BOOKS. 583

Analyses of ferruginous schists.

A. Griinerite-magnetite schist, Marquette region, Micl- ..n. Contains griinerite, 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 AV. H. Melville.

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

A1AI 2nU3 . .........................................................

Fe,03 . . ........................................................

FeO

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

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

Na2 0 ..........................................................

H26..... .......................................................

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

P205 -----------------------------------------------------------

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

CuO. ..........................................................

A

46.25

.92

30.62

16.92

2.13

1.69

.42

,.07

1.01

100. 03

B

12.35

.10

58.68

21.34

4.08

1.91

.19

.12

.25

1 99

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 dehydrated, 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

1 See p. 577, ante.
584 THE DATA OF GEOCHEMISTRY.

chemical compounds. The following minerals in this class are recognized by Dana as true species :

Kaolinite. . ................................... .H4

Halloysite. .................................... H4Al2Si209+aq.

Newtonite. .................................. .H8Al2Si2Ou+aq.

Cimolite..... . ............................... .H6Al4Si9027 +3 aq. (?)

Montmorillonite. .............................. .H2Al2Si4012+n aq.

Pyrophyllite. ................................ .H2Al2Si4012 .

Allophane. ................................... . Al2Si05 .5aq.

Collyrite. ..................................... Al4Si08 .9aq.

Schrotterite. . .................................. Al16Si3 030 .30aq.

To this list rectorite l 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 HAlSiO4 , or H3Al3Si3012 , 

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 of phyllite 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 SiO2 . Al2Si05 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 characteristic of the metamorphic schists, and must have been formed in most 

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 biotite-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 con1 Am. Jour. Sci., 3d ser., vol. 42, 1891, p. 16.

2 Bull. Soc. min.j vol. 22, 1899, p. 27.

8 See J. Uhlig, Zeitschr. Kryst. Min., vol. 47, 1910, p. 215, and A. Sauer, Zeitschr. Deutsch. geol. Gesell., 

vol. 38, 1886, p. 705. 

< Neues Jahrb., 1897, pt. 2, p. 156. 

6 Bull. Soc. min., vol. 13, 1890, p. 256. See also J. W. Mellor, Jour. Soc. Chem. Ind., vol. 26, 1907, p. 375,
METAMOBPHIC BOOKS. 585

stituent of hard porcelain, in which it is derived from kaolinite; and 

also that kyanite and andalusite are convertible into sillimanite by 

heating to a temperature of 1,320° to 1,380°. Kyanite often occurs 

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 wnich bear obviously upon the interpretation of metamorphic 

processes. We do not yet know, however, the conditions which determine the formation in a 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 products derived from them. The argillite of Harvard, Massachusetts, according to B. K. Emerson,2 contains andalusite inclosing sillimanite, 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, HAl5FeSi2013 , 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 retentipn 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 

H3FeAl2Si07 ; but that of ottrelite is not certain. The best evidence goes to show that the two minerals are alike in type, except

i The reported alteration of kyanite into steatite is most questionable. Probably a compact muscovite 

(damourite) has been mistaken for talc. 

* Bull. Geol. Soc. America, vol. 1,1889, p. 559.
586 THE DATA. OF GEOCHEMISTRY.

that chloritoid is an orthosilicate, and ottrelite a trisilicate. On this 

supposition the two formulae become

A102Fe.Si04 .A10H.H. AlO2Fe.Si308 .A10H.H.

Chloritoid. Ottrelite.

Magnesium may replace iron to some extent, and in the Belgian 

ottrelites manganese plays a similar part. By dehydration, chloritoid would become A102Mg.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. Hutchings,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 ° 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.

1 Am. Jour. Sci., 3d ser., vol. 44,1892, p. 270.

2 Annales Soc. gSol. du Nord, vol. 15, p. 185.

s Geol. Mag., 1889, p. 214.

« Bull. Mus. Comp. Zool., vol. 16,1890, p. 159.

6 Neues Jahrb., Beil. Bd. 4,1886, p. 143.

»Annales Soc. g6ol. du Nord, vol. 11,1884, p. 18.

7 Jour. Coll. Scl. Japan, vol. 5,1893, p. 270.

8 Lehrbuch der Petrographie, 2d ed., vol. 3, pp. 282,294,303-306.
METAMOBPHIC BOCKS. 587

Analyses ofandalusite and chloritoid rocks.

A. Andalusite schist, Mariposa County, California. Analysis by W. F. Hillebrand.' Described by H. W. 

Turner, Seventeenth Ann. Rept. U. S. Geol. Survey, pt. 1,1896, p. 691. Contains quartz, biotite, andaluslte, 

sericite, and minor accessories.

B. Chiastolite schist, Mariposa County, California. Analysis by G. Steiger. Described by Turner, Bull. 

U. S. Geol. Survey No. 150,1898, p. 342. Contains andalusite (chiastolite), sillimanite, mica, etc.

C. Andalusite hornfels, Mariposa County. Analysis by Steiger. Described by Turner, op. cit., p. 342. 

Contains quartz, andalusite, mica, etc.

D. Andalusite schist, Skamania County, Washington. Analyzed and described by W. T. Schaller, 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.

E. Kyanite schist, Serra do Gigante, Brazil. Analysis by Hillebrand. Described by 0. A. Derby, Am. 

Jour. Sci., 4th ser., vol. 7,1899, p. 343. Consists mainly of kyanite, chlorite, sericite, quartz, and rutile.

F. Sillimanite schist, San Diego County, California. Analysed and described by Schaller, Bull. No. 262, 

1895, p. 98. Mainly quartz, 69 per cent, and sillimanite, 31 per cent, neglecting water and minor accessories.

G. Chloritoid-phyllite, Liberty, Maryland. Analyzed by L. G. Eakins. Called "ottrelite-phyllite" by 

G. H. Williams, but the characteristic mineral is chloritoid. See Bull. U. S. Geol. Survey No. 228, p. 59.

H. 0 ttrelite schist, Montherme', Belgium. Analyzed by C. Element, described by A. F. Renard. Renard'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 see vol. 3, 

p. 255. It contains ottrelite, 46.11 per cent; sericite, 23.35 per cent; and quartz, 23.15 per cent.

SiOa ................

A1203 --- ............

Fe203 --- ------------

FeO.................

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

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

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

K,0. ................

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

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

TiOa ................

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

C....... ............

sos .......... ........

,<a

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

01...................

P O

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

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

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

(NiCoK). ............

LijO. '...............

FeSa ..............l.

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

trace

100. 06

B

62.15 

19.34 

4.23 

2.25 

1.88 

1.50 

1.60 

3.07 

.19 

1.79 

.80

1.12 

.13

.22 

none 

.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

i.2~i

.03

.12 

trace 

.14 

none 

none 

none

none

100. 80

D

57.18 

34.10 

.54 

.28 

.10 

.63 

.39 

2.57 

.69 

2.02 

.66 

.02

.53 

none 

.04 

trace?

none 

.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?

.47 

.16

trace 

.04

trace

100. 07

F

75.54 

18.65 

.35 

.06 

none 

.03 

none 

none 

1.10 

3.67 

.48 

.06

trace

.10

100. 04

G

34.92 

32.31 

10. 21 

8.46 

1.13 

.36 

2.12 

1.87

j 5.29 

3.37

.23 

trace

100. 27

H

51.93 

27.45 

2.01 

8.10 

1.20 

.18 

.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,
588 THE 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. Mca 

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-sericite 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. S. 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 H. L. 

Smyth, Mon. U. S. Geol. Survey, vol. 36, 1898, p. 274. Contains biotite, quartz, some microcline, and 

magnetite.

E. Mica schist, near Guriflint 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.

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

Al O

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

FeO

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

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

Na20........................ K.O:..,...... ................

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

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

TiO

ZrOa ... ......................

rr>

p r>

so,. ........................

F

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

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

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

Li20. ........................

C.... ........................

FeS2 -. .......................

A

90.91

4.18

.22

1.27

.37

.22

.77

.58

.06

.74

.28

.02

.18

.05

none

trace

.10

.11

100. 06

B .

57.24

23.48

3.19

4.87

.93

.09

1.18

3.55

.33

4.65

.08

.09

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

q 17

3.46

.19

.91

.51

.05

.08

.09

.15

100. 03

i See C. R. Van Hise, Bull. Geol. Soc. America, vol. 1,1899, p. 206, on schists from the Black Hills.
METAMOEPHIC BOOKS. 589

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 borosilicates, 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 an earlier chapter,1 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 

of these seems to be the contact between mica schist and granite 

on Mount Willard, in the White Mountains of New Hampslu're, as 

described by G. W. Hawes.2 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 See ante, Chapter VIII.

«Am. Jour. Sci., 3d ser., vol. 21,1881, p. 21.
590 THE DATA OF GEOCHEMISTRY.

Analyses of granite and mica schist near contact, Mount Willard.

A. The normal Albany granite. 

B. Porphyry, 3 feet from contact. 

C. Porphyry, 2 inches from contact. 

D. Tourmaline veinstone, on contact.

E. Tourmaline hornstone, 1 foot from contact. 

F. Schist, 15 feet from contact. 

G. Schist, 50 feet from contact. 

H. Schist, 100 feet from contact.

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

A1203 --.------ - -

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

FeO................. Mgo. ..............:..

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

Na20. ................

KtO. ................

H20.... .............

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

B203 - --- .............

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

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

A

72.26

13.59

1.16

2.18

.06

1.13

3.85

5.58

.47

.45

100. 73

B

73.09

12.76

1.07

4.28

.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

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

.11

101. 20

F

66.30

16.35

.95

5.77

1.63

.24

1.11

3.40

3.02

1.28

100. 05

G

63.35

19.69

.72

5.48

1.77

1.12

3.47

3.73

1.00

.16

100. 49

H

61.57

20. 55

2.02

4.28

1.27

.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 JI, 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.

Biotite. ...............................

Chlorite..... ..........................

Magnetite... . .........................

D

50.03

1.94

2.86

45.95

E

50.82

| 29. 67

1.77

3.44

14.92

F

45.15

| 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.
METAMOBPHIC BOOKS. 591

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 recrystallized 

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. Eosenbusch 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.

The following analyses of gneiss, with the exception of the Canadian example, were made by the chemists of the United States 

Geological Survey.

i Handbook of Rocks, 3d ed., p. 123.

» Bull. Geol. Soc. America, vol. 7,1895, p. 122.

»Mitth. Gr. badisch. geol. Landesanstalt, vol. 4, Heft 1,1899.

< Elements der Gesteinslehre, 2d ed., p. 484.
592 THE DATA OF GEOCHEMISTRY.

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 analyses 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. Keyes, 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. H. 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. 150,1898, p. 358. Contains quartz, plagioclase, and pyroxene, with accessory 

biotite, garnet, pyrite, and magnetite.

SiOa .................

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

Fe203 - ---------------

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

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

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

Na20..................

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

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

H20+- ...............

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

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

C02 . .................

P O

s?°v.::::::::::::::::

Fe7S8 ... ..............

FeSa . ................

O203 . ................ Nib... ..............

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

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

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

Li20.................

A

61.96

19.73

4.60

1.81

.35

.79

2.50

j 1.82

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

.16

.03

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

none

99.87

D

48.92

16.57

4.21

9.18

5.98

9.69

2.47

1.56

. DO

trace

100. 26

E

78.28

9.96

1.85

1.78

.95

1.68

2.73

1.35

.12

.83

.70

.11

.08

.02

trace

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

1 43 1 -^

3.73

98.87

In a broad way the general order of change froni 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.

1 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. 419,1910; the shale average on p. 10.
METAMOBPHIC EOCKS. 593

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.

8i03 .:,......... ..............................

A12 03 - .......................................

Fe/)3 - ........................................

FeO.3... .......................................

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

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

Na20.........................................

K26. ..........................................

H20...........................................

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

mco^---------------

s6,?v:::::::::::::::::::::::::::::::::::::::: ci............ .................................

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

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

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

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

Li20..... .....................................

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. 4.6

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

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

.55

none

.12

flQ

.07

.03

.05

trace

.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 metamorpMc processes.

METAMORPHIC LIMESTONES.

The metamorphism of limestone is affected 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.

101381° Bull. 491 11 38
594 THE DATA OF GEOCHEMISTRY.

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, 

CaSiO3 , 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. White 1 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

' Am. Jour. Sci., 4th ser., 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.
METAMOEPHIC BOOKS. 595

found in crystalline limestone, and so, too, are the red and blue 

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. Cinnamon 

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, monticellite 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

1 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.

3 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. Stei 

ger, is given, and also its mineralogical composition.
596 THE 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 

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 here 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, dysanalytej 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 

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. Rastall, Quart. 

Jour. Geol. Soc., vol. 66,1910, p. 507.

2 See ante, pp. 544, 545.

3 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. 

«Am. Geologist, vol. 14,1894, p. 308.

5 Atti Soc. toscana sci. nat., Pisa, vol. 21,1905.'

6 A list is given by F. Zirkel in Lehrbuch der Petrographie, 2d ed., vol. 3, p. 448. See also B. Lindemann 

Neues Jahrb., Beil. Bd. 19,1904, p. 197. For the Ceylonese localities, see A. K. Coomara-Swamy, Quart. 

Jour. Geol. Soc., vol. 58,1902, p. 399. J. F. Kemp and A. Hollick have described the crystalline limestones 

of Warwick, New York, hi Annals New York Acad. Sci., vol. 7, 1893, p. 644.
METAMORPHIC ROCKS. 597

Analyses of metamorphic silicate rocks.

A. Wollastonite gneiss, Amador County, California. 'Analysis by W. F. Hillebrand. Described by 

H. W. Turner, Seventeenth Ann. Kept. U. S. Geol. Survey, pt. 1,1896, p. 521. Consists mainly of wollastonite, but garnet, quartz, and titanite are also present.

B. Prehnite rock, Black Forest, Germany. Analysis by C. Schnarrenberger. Described by H. Rosenbusch, Mitt. Gr. badisch. geol. Landesanstalt, vol. 5, Heft 1,1905. Estimated to contain 46.2 per cent 

prehnite, 37.9 albite, 13.8 actinolite, 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 Kosenbusch, loc. cit. 

Probably derived from an original mixture of 48 per cent carbonates and 52 of silicates, chiefly kaolin. 

Contains about 75 per cent garnet, 10 per cent soda-potash mica, and 15 per cent hornblende.

SiOa ......... ...........................................

A12 03 . ................................................

Fe2 03 . ................................................

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

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

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

Na20.................. -K2b........ ...........................................

H20. ..................................................

TiOa ....... ...........................................

C02 ...................................................

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

A

50.67

6.37

.31

.50

.58

40 34

.14

.22

.39

.20

.52

trace

100. 24

B

50.65

19.54

3.34

none

3.92

16.11

3.91

.84

a 3. 10

100. 41

C

41.01

18.50

6.57

11.06

11.02

10.31

.48

.31

1.18

100. 44

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. Bastin,1 

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 conclusion 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 in 

excess of potash, but decomposition changes the ratio, which, in

1 Jour. Geology, vol. 17,1909, p. 445.

2 For example, an amphibolite derived from limestone was shown by F. D. Adams (Jour. Geology, vol. 

17,1909, p. 1) to fall under the heading of auvergnose.
598 THE DATA OP GEOCHEMISTRY.

sedimentary rocks, is often reversed. Dominance of potash over 

soda, then, is an indication of sedimentary origin. Dominance of 

magnesia over lime is another similar criterion, and any excees 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 OEES. 

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 ore 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 chromite, tinstone, gold, platinum, etc., are detrital in character; many manganese 

and iron ores are sedimentary rocks, and from the latter metamorphic 

beds of magnetite or hematite are derived. Some ore bodies are resi1 For recent papers and works on this subject, see F. Posepny, 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 1'etude des gites metalliferes, 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 Erzlagerstatten, 

Berlin, 1903, and its English translation by Weed, New York, 1905; A. W.Stelzner and A. Bergeat, Die 

Erzlagerstatten, 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. Geologie, 1899, p. 173; F. Beyschlag,.P. Krusch, 

and J. H. L. Vogt, Die Lagerstatten der nutzbaren Mineralien und Gesteine, Stuttgart, 1910.

599
600 THE DATA O'F GEOCHEMISTRY.

dues 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 correlated. 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 

these facts he based his famous theory of "lateral secretion." That 

is, Sandberger concluded that metalliferous veins derived their metallic contents by lateral leaching from adjacent rocks. This theory 

however, was subjected to much criticism by A. Stelzner, F. Pos"epny,

1 C. E. Keyes (Bull. Am. Inst. Mln. Eng., 1910, p. 527) has suggested the possible derivation of heavy 

metals from meteoritic matter, especially meteoric dust.

2 Pogg. Annalen, vol. 95, p. 60.

3 Untersuchungen iiber Erzgange, Wiesbaden, 1882 and 1885. See also Neues Jahrb., 1878, p. 291, on 

copper, lead, cobalt, and antimony in basalt.
OBES, 601

and others,1 it being shown that in some instances at least the country 

rocks 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 determinable 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, though sometunes 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. Eramons,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 107,200. 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. Robertson 11 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.

> A. Stelzner, Zeitschr. Deutsch. geol. Gesell., vol. 31,1879, p. 644, and rejoinder by F. Sandberger, idem, 

vol. 23,1880, p. 350. F. Pogepny, Trans. Am. Inst. Min. Eng., vol. 23,1893, pp. 247-254. 

a Compt. Rend., vol. 32,1851, p. 827. 

s Mon. U. S. Geol. Survey, vol. 13,1888, p. 350. 

4 Idem, vol. 12,1886, pp. 591-594.

6 Idem, vol. 3,1882, pp. 223-227. Assays by J. S. Curtis. 

«Idem, vol. 7,1884, pp. 80-92.

' Seventeenth Ann. Rept. U. S. Geol. Survey, pt. 2,1896, p. 471. Assays by L. G. Eakins. 

s Chem. News, vol. 55,1887, p. 17.

9 Proc. Roy. Soc., vol. 47,1890, p. 277.

10 Gazz. chim. ital., vol. 36, pt. 2,1906, p. 797.

11 Missouri Geol. Survey, vol. 7,1894, pp. 479-481.
602 THE 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. A still larger series of igneous and 

metamorphic rocks from British Guiana, analyzed by J. B. Harrison,3 also yielded appreciable quantities of cppper, with sometimes 

other heavy metals. In 36 rocks examined 6 contained no copper, 

12 contained it in traces, and one, a feldspathic 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.

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 upon page 27. Copper is determined 

in exceptional cases only, but indications of its presence are frequently 

observed. In a typical sample of the Columbia River basalt, which 

covers a large area, R. C. Wells found 0.034 per cent of copper. It 

is probably as abundant as nickel, and possibly more so. Of its wide 

distribution in 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. They also appear in many mineral springs,4 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 true origin of the latter is not thereby explained.

1 Annaleschim. 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.

a Rept. 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. 386; and 

also In Min. Industry, vol. 7, p. 315.

i See p. 177, ante, for examples. The traces of heavy metals which spring waters contain are often more 

easily detected in their sediments; that is, they become concentrated in the insoluble precipitates that 

spring waters often deposit.
METALLIC ORES. 603

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 1 found that sulphides of iron, nickel, 

cobalt, antimony, arsenic, silver, and tin were attacked by boiling 

water, hydrogen sulphide being given off. Some were acted upon 

even at temperatures below 100°; As2S3 at 22°, FeS at 56°, Ag2S 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 2 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 instead of 

water. The following percentages of material passed into solution:

Material dissolved from natural sulphides in water and in SOdlUm Sulphide solution.

Galena. .................................................... ^

Pyrite. . ...................................................

Blende. ...................................................

Chalcopyrite. ..............................................

Bournonite ................................................

Arsenopyrite. ...............................................

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.3

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

1 Annales chim. phys., 5th ser., vol. 18,1879, p. 189.

2 Min. pet. Mitt., vol. 11,1890, p. 319. Eesearch continued by G. A. Binder, idem, vol. 12,1892, p. 332.

a Still more recently 0. Weigel (Nachrichten K. Gesell. Gottingen, Math.-phys. Klasse, 1906, p. 525) has 

determined the solubility in pure water of the sulphides of Pd, 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.
604 THE DATA OF GEOCHEMISTRY,

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 1 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 

by J. A. Reid,2 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. 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

Analyses of mine waters.

A. Water from 500-foot level of Geyser mine, Custer County, Colorado.

B. Same locality as A, from the 2,000-foot level. Contains also traces of Br, I, F, and B^O?. Analyses 

A and B by W. F. Hillebrand. Discussed by S. F. Emmons, Seventeenth Ann. Rept. 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 hole 2,316 feet deep, in the Mizpah mine, Tonopah, Nevada. Analysis by 

R. C. Wells. Bicarbonates here reduced to normal carbonates.

E. Water from St. Lawrence mine, Butte, Montana. Analysis by Hillebrand.

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 find 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.

I. Water from the Burra Burra mine, Ducktown, Tennessee. One of a series of six analyses of mine 

waters by R. C. Wells.

J. Water from the Rothschonberger Stolln, Freiberg, Saxony, at its point of discharge into the Triebisch 

Valley. Analysis by Frenzel. Described by H. Muller, Jahrb. Berg- u. Hiitt. Konig. Sachsen, 1885, p. 

185. Discharges 479 kilograms of ZnO daily, or 175,024 kilograms per annum.

1 Records Geol. Survey New South Wales, vol. 8,1909, p. 292.

2 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, Robinson district, Nevada.

3 For other analyses of mine waters, see J. A. Phillips, Phil. Mag., 4th ser., vol. 42,1871, p. 401. A. Schrauf, 

Jahrb. K.-k. geol. Reichsanstalt, vol. 41,1891, p. 35. A. C..Lane, Proc. Lake Superior Min. Inst., vol. 12, 

1906, p. 97. A few others have already been cited in the chapter on mineral springs. F. PoSepnJ- (Trans. 

Am. Inst. Min. Eng., vol. 23,1893, p. 240) has tabulated the occurrences of Sn, Sb, Cu, and As in mineral 

waters.
METALLIC OEES. 605

01.............. ............

S04 ................ .........

co».. ......................

N03 . ......................

POl^:.y.::::::::::::::::::::

Na........................

Li.........................

Ca.........................

Sr..... .....................

Mg.........................

Al..........................

Fe'". .......................

Fe". .......................

Mn.........................

Ni.........................

Co.........................

Cu.........................

Zn........ ................

Cd.........................

Pb.............. ...........

Sn... .......................

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

Total C02 . ...........

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

S04 .. .......................

PO

K..........................

Na. .......................

Li.........................

Ca.........................

Mg.........................

Al..........................

W. ............... ........

Fe".. ......................

Mn............... ..........

Ni.........................

Co.........................

Cu.........................

Zn.........................

Cd.........................

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

H2S04 , free. ...............

Total C02 . ...........

A

7.9

43.2

110.5

10.6

36.4

37.4

12.25

0.4

} '

.8

trace

.2

trace

25.9

286. 25

F

17.7

71, 053. 3

1.5

6.8

41.7

trace

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

B

186. 40

161. 70

1, 513. 44

1.60

198. 00

71 Q 4^1

2.85

146. 41

1.95

177. 67

1.06

1 3.50

.57

.02

.34

1.35

24.42

3, 140. 73 

2, 528. 46

G

2.7

6, 153. 2

.5

49.9

none

345.3

25.2

142.1

| 474. 6

1.7

3.7

2, 412. 0

9.0

107.6

9, 727. 5

c

 8.16

2, 039. 51

70.00

106. 27

187. 15

93.50

3.12

164. 82

3.44

155. 58

77.05

49.66

43.80

3, 002. 06

H

3.65

1, 647. 58

3.20

13. 02

260. 45

48.60

11.70

142. 80

345. 10

23.20

251. 70

2, 751. 00 

87.0

D

35.6

327.2

87.9

3.4

148.8

68.8

6.3

.7

\ '

trace

64.8

744.2 

121.2

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

E

13.0

2, 672. 0

13.1

39.6

132.5

61.6

83.5

| 159. 8

12.0

1 5

/ " 5

59.1

852.0

41.1

17.0

47.7

4, 204. 5 

23.7

J

12.4

124.8

46.4

14.5

> o.o

8.9

18.0

" 231. 6

AhOs+PaOs, 0.8 per million. 6244.9 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.
606 THE DATA OF GEOCHEMISTRY.

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 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 in 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.2 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,3 and

i For the remarkable calcium chloride waters of the Lake Superior copper region see ante, p. 174.

* See L. De Launay, Contribution a l'6tude des gites me'talliferes, 1897, p. 6; and F. PoSepny, 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. E. Van Hise (A treatise on metamorphism: Mon. U. S. Geol. Survey, vol. 47,1904) dissent from 

this view. The importance of 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.

8 A treatise on metamorphism; Moru U. S. Geol. Survey, vol. 47,1904, chapter 12.
METALLIC ORES. * 607

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 heavy metals are produced, and in most cases, but not invariably, 

they appear in association with rocks of igneous origin. 1 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 

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 

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, wollastonite, pyroxene, vesuvianite, and so on. 2 Aqueous solutions take 

part in some of these changes, penetrating the walls of the contact 

and bringing about metasomatic replacements. 3

i 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.

a See W. Lindgren, Trans. Am. Inst. Min. Eng., vol. 31,1901, p. 226.

8 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.
608 THE DATA OF GEOCHEMISTRY.

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 substances 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.

The heavy metals, however, are not laid down as chlorides or fluorides except in rare instances; but in other forms chlorine and fluorine 

1 have acted as primary agents in bringing about their concentration, 

and water tends to hydrolyse 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, 

fluor spar; 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 entitled 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 generate actively solvent solutions that come into play later. That is, a
METALLIC ORES. 609

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.

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 differentiation, the segregation of certain parts, takes place.

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 

101381° Bull. 491 11 39
610 THE DATA OF GEOCHEMISTRY.

with other solutions as its 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 no*", 

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 compounds 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 partially known.2

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

1 See ante, p. 283.

2 For a summary of these alterations, see R. A. F. Penrose, Jour. Geology, vol. 2,1894, p. 288. Also Do 

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.
METALLIC OEES. 611

rocks. That decomposition is more than ordinarily extensive in the 

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, forming 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, more or less perfectly, and carried down to lower levels.

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 

cerussite 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

i On secondary enrichment, see W. H. Weed, Bull. Geol. Soc. America, vol. 11, 1899, p. 179; S. F. 

Emmons, Trans. Am. Jnst. 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. Eansome, Econ. Geology, vol. 5,1910, p. 205. 

Discussion by several writers of Eansome'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.
612 . THE DATA OF GEOCHEMISTRY.

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. Anthon1 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.2 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 

sulphide of any of the metals following it in the series, it would 

decompose the latter with precipitation of copper sulphide. The 

reaction CuS04 + PbS = CuS + PbS04 has been actually studied by 

R. C. Wells,3 in the laboratory of the United States Geological 

Survey. Wells has also investigated the precipitation of sulphides 

in pairs, 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.

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.4 The diffused metals, or rather their compounds, may

1 Jour, prakt. Chemie, vol. 10,1837, p. 353.

2 Liebig's Annalen, vol. 249,1888, p. 326.

«Econ. Geology, vol. 5,1910, p. 1.

< See for example, R. Irvine and W. S. Anderson, Proc. Roy. Soc. Edinburgh, vol. 18, 1890, p. 52; W. 

Meigen, Ber. Naturforsch. Gesell. Freiburg, vol. 13,1903, p. 40; vol. 15,1905, p. 38; and inaugural dissertations, Freiburg, 1906, by L. Gassner and C. Mahler.
METALLIC OKES. 613

be concentrated by solution and consequent removal of the remaining 

carbonate of lime.1

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 

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,° 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 discovered it 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 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.

2 The ores of iron, manganese, and aluminum have been sufficiently described in the chapters upon rockforming minerals, rock decomposition, and the sedimentary rocks.

3 For a list of the Survey publications on gold and silver see Bull. 470,1911.

< See ante, p. 111.

6 Jour. Chem. Soc., vol. 71,1897, p. 298.

e Compt. Rend., vol. 142,1906, p. 1409. Also in Compt. Rend. Soc. ind. minerale, Sept.-Oct., 1906.

' Am. Jour. Sci., 4th ser., vol. 1,1896, p. 309. Compare W. P. Blake, Trans. Am. Inst. Min. Eng., vol. 26. 

1896,p. 290.

«Min. pet. Mitt., vol. 12,1891, p. 195.

"Zeitschr. Deutsch. geol. Gesell., vol. 40, 1888, p. 611. For other examples see Stelzner-Bergeat, Die 

Erzlagerstiitten, 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. R. 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. Min. Eng., vol. 39,1909, p. 97.

10 Trans. Am. Inst. Min. Eng., vol. 31,1901, p. 808.
614 THE DATA OF GEOCHEMISTRY.

Gold and silver in rocks from California, Nevada, etc. 

[Milligrams per metric ton.]

Granite .................................................

Do. .................................................

Do. ................................................

Syenite, Nevada ........................................

Sandstone ...............................................

Do..................................................

Do..................................................

Marble ............................................'......

Marble, Carrara ..........................................

Au.

104

137

115

720

1,130

39

24

21

26

76

5

8.63

A<g.

7,660

1,220

940

15, 430

5,590

540

450

320

547

7,440

212

201

These figures suggest a very general distribution of gold in rocks 

of all kinds. J. R. Don/ 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,2 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.

On the petrologic side gold is most commonly associated with 

rocks of the persilicic type, such as granite and its metamorp.hic 

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

1 Trans. Am. Inst. Min. Eng., 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.

2 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.
METALLIC OKES. 615

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. Catlett in the laboratory of the United States Geological Survey.

B. Electrum, Montgomery County, Virginia. Analysis by S. Porcher, Chein. News, vol. 44,1881, p. 189.

C, D, E. Gold associated with native platinum, Colombia. Analyses by W. H. Seamon, Chem. News, 

vol. 46,1882, p. 216.

F. Amalgam, Mariposa County, California. Analysis by F. L. Sonnenschein, Zeitschr. Deutsch. geol. 

Gesell., vol. 6,1854, p. 243. Specific gravity, 15.47. Near AuHg3 .

G. Palladium gold. Taguaril, Brazil. Analysis by Seamon, Chem. News, vol. 46, 1882, p. 216. See 

Wilm. Zeitschr. anorg. Chemie, vol. 4,1893, p. 300, on palladium gold from the Caucasus. Also E. Hussak, 

Zeitschr. prakt. Gcologie, 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 AuaBi.

Au ..................

Ag ..................

Cu. .................

Eg..................

Pd ..................

Bi.. .................

Fe ..................

A

93.24

6.65

.11

100. 00

B

65.31

34.01

.14

.20

.34

100. 00

C

84.38

13.26

1.85

99.49

D

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

trace

99.27

H

65.12

34.88

100. 00

The tellurides 4 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

1 See papers in Trans. Am. Inst. Min. Eng., vol. 33,1903, p. 288; vol. 36,1906, p. 372. Also Econ. Geology, 

vol. 1,1900, p. 369.

2 A treatise on metamorphism: Mon. U. S. Geol. Survey, vol. 47,1904, pp. 1048-1049. See 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.

3 Proc. Roy. Soc. Now South Wales, vol. 18,1884, p. 37.

* For a general review of the tellurides, with references to literature, see J. F. Kemp, Min. Industry, 

vol. 6,1898, p. 295.
616 THE DATA OF GEOCHEMISTRY.

of the mercury compound, coloradoite, with other species. 1 Calaverite approximates to gold telluride alone. The following analyses are 

sufficient to indicate the composition of these minerals:

Analyses of tellurides containing gold.

A. Calaverite, (AuAg)Te2, Cripple Creek, Colorado. Analysis by W. F. Hillebrand.

B. Krennerite, (AuAg)Tea, Nagyag, Hungary. Analysis by L. Sipocz, Zeitschr. Kryst. Min., vol. 11, 

1886, p. 210.

C. Sylvanite, (AuAg)Tes, Grand View mine, Boulder County, Colorado. Analysis by F. W. Clarke, 

Am. Jour. Sci., 3d ser., vol. 14, 1877, p. 286.

D. Petzite, (AuAg)2Te, Norwegian mine, Calaveras County, California. Analysis by HiUebrand.

Au...................................... ......

Ag. ............................................. cL...... ......................................

Fe.......... ..................................

TQ.......... ..................................

Se............................................

Mo...........................................

Sb............................................

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

Insoluble. ....................................

A

38.95

3.21

57.27

.12

.33

99.88

B

34.77

5.87

.34

.59

58.60

.65

100. 82

C

29.35

11.74

58.91

100. 00

D

25.16

41.87

33.21

. .08

' 100. 32

There has been much discussion over the tellurides of gold. B. 

Brauner 2 asserts that crystalline " poly tellurides" 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,3 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,4 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.5 

W. J. Sharwood 6 has pointed out the very general association of 

bismuth with tellurium gold ores.

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, 7 for instance, mentions gold incrusting siderite at Eisenberg, near Corbach, in Germany. 0. A. Derby 8 reports films of gold on limonite, from Brazil.

1 See L. J. Spencer, Mineralog. Mag., vol. 13,1903, p. 268. Spencer gives a good bibliography of the Australian tellurides.

2 Jour. Chem. Soc., vol. 55,1889, p. 391.

3 Jour. Am. Chem. Soc., vol. 24,1902, p. 358. See also R. D. Hall and V. Lenher, idem, p. 919.

< Trans. Inst. Min. Met., vol. 17,1908, p. 285.

6 Rend. Accad. Lincei, 5th ser., vol. 19,1910, p. 445. '

o Econ. Geology, vol. 6,1911, p. 22.

i Neues Jahrb., 1854, p. 324.

s Am. Jour. Sci., 3d ser., vol. 28,1884, p. 440.
METALLIC OEES. 617

A. Liversidge 1 found it in recent pyrite, which formed on twigs in 

a hot spring near Lake Taupo, New Zealand. J. C. Newbery 2 mentions gold in a manganiferous iron ore coating quartz pebbles, the 

quartz itself being free from gold. In the sinter of Steamboat 

Springs, Nevada, G. F. Becker 3 found both gold and silver; 3,403 

grams of sinter gave 0.0034 of gold and 0.0012 of silver. Gold is 

also reported by J. M. Maclaren 4 -in the siliceous sinter of the hot 

springs at Whakarewarewa, New Zealand. R. Brauns 5 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,0 which was covered by a later deposit of gold, is also 

suggestive. 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 natural solvents of gold appear to be numerous that is, if 

the recorded experiments are all trustworthy. G. Bischof 7 found 

that gold was held in solution by potassium silicate, and Liversidge 8 

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. 

C. Doelter 0 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,10 T. Egleston, 11 G. F. Becker,12 

and A. Liversidge, 13 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, 14 ferric sulphate and 

ferric chloride are both effective. P. C. Mcllhiney l5 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, 16 in the laboratory of the United States Geological Survey, showed that ferric chloride and also cupric chloride

1 Jour. Roy. Soc. New South Wales, vol. 11,1877, p. 262.

2 Trans. Roy. Soc. Victoria, vol. 9,1868, p. 52. 

a MOD. U. S. Geol. Survey, vol. 13,1888, p. 344. 

<Geol. Mag., 1906, p. 511. 

&Chemische Mineralogie, p. 406,1896.

«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.

' Lehrbuch der chemischen und physikalischen Geologie, 2d ed., vol. 3, p. 843. 

8 Proc. Roy. Soc. New South Wales, vol. 27,1893, p. 303. 

»Min. pet. Mitt., vol. 11,1890, p. 328.

10 Trans. New Zealand Inst., vol. 3,1870, p. 216; vol. 5,1872, p. 382.

11 Trans. Am. Inst. Min. Eng., vol. 9,1880-81, p. 639.

w Am. Jour. Sci., 3d ser., vol. 33,1887, p. 207.

is Proc. Roy. Soc. New South Wales, vol. 27,1893, p. 303.

>< Am. Jour. Sci., 2d ser., vol. 26,1858, p. 51.

" Idem, 4th ser., vol. 2,1896, p. 293.

<«Econ. Geology, vol. 1,1906, p. 650.
618 THE DATA OF GEOCHEMISTRY.

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, 1 may have originated from some solution in ferric salts.

F. P. Dewey 2 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 3 has reported its solubility 

in hydrochloric acid solutions of iron alum and cupric chloride. 

With rising temperature the solubility increases rapidly. N. Awerkiew 4 finds that gold is also dissolved by hydrochloric acid in presence of organic matter.

The usual laboratory solvent for gold, aqua regia, owes its efficiency 

to the liberation of free chlorine. T. Egleston 5 asserts that traces of 

nitrates with chlorides in natural waters can slowly dissolve the 

metal. J. R. Don 6 found that weak hydrochloric acid, 1 part in 

1,250 of water, in presence of manganese dioxide, would take gold 

into solution. R. Pearce 7 heated gold and a solution containing 40 

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 8 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 

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, 9 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, 10 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.

iTrans. New Zealand Inst., vol. 14, 1881, p. 457. Campbell's observation needs to be verified. The 

specimen was found in the Thames gold field, New Zealand. 

2 Jour. Am. Chcm. Soc., vol. 32,1910, p. 318. 

a Idem, vol. 31,1909, p. 1261. 

a Zeitschr. anorg. Chemie, vol. 61,1909, p. 1. 

* Trans. Am. Inst. Min. Eng., vol. 8,1879-80, p. 454.

8 Idem, vol. 27,1897, p. 564. According to Don, ferric salts are not effective solvents for gold. 

' Idem, vol. 22,1893, p. 739.

8 Idem, vol. 26,1896, p. 978.

9 Jour. Am. Chem. Soc., vol. 26,1904, p. 550.

i° 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, p. 321.
METALLIC OEES.

The experiment by Bickard just cited is especially suggestive as 

illustrating the ease with which gold is redeposited from its solutions: 

So far as gold is concerned, the reducing agents are numberless, and 

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.1

Gold is also thrown out of solution by ferrous salts, by other metals, 

and by many sulphides, especially by pyrite and galena. 2 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 

same way. So too does tellurium, according to V. Lenher,3 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. 4

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 5 found it in rock salt, seaweed, and oyster shells, while 

W. N. Hartley and H. Ramage 0 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 many 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 

to 95!8 per cent of silver, with from 72.5 to 3.6 per cent of mercury.

1 On the relations of vegetation to the deposition of gold see E. E. Lunqwitz, Zeitschr. prakt. Geologie, 

1900, pp. 71, 213.

3 See C. Wilkinson, Trans. Boy. 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. Liversidge, Proc. Roy. Soc. New South Wales, vol. 27, 

1893, p. 303.

3 Jour. Am. Chem. Soc., vol. 24,1902, p. 355. Also R. D. Hall and V. Lenher, idem, p. 919.

4 For a list of the Survey publications on gold and silver see Bull. 470,1911. 

6 Jour. Chem. Soc., vo!. 71,1897, p. 298. 

8 Idem, vol. 71,1897, p. 533.
620 THE DATA OF GEOCHEMISTRY.

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 1 mentions films of silver upon the 

scales of fossil fishes from the Mansfeld copper shales. According 

to J. H. L. Vogt 2 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. 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 

with calcite, and thinks that ferrous compounds or carbonaceous substances are the precipitants. Pyrite precipitates the silver as sulphide.

The reduction of silver and its complete precipitation in the metallic state by organic matter was long ago observed by H. de Senarmont.3 T. A. Rickard 4 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. 5 Any reaction, however, which generated 

nascent hydrogen in contact with silver solutions would precipitate 

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 solutions of 

ferric sulphate, a reaction which has recently been studied by H. N. 

Stokes 6 in the laboratory of the United States Geological Survey. 

The reaction, 2Ag + Fe2 (SO4 ) 3 =Ag2S04 + 2FeS04J is reversible, and 

crystallized 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.7

1 Ore deposits, Weed's translation, p. 371.

2 Zeitschr. prakt. Geologie, 1899, pp. 113,177. 

s Annales chim. phys., 3d ser., vol. 32,1851, p. 140. 

* Trans. Am. Inst. Min. Eng., vol. 26,1896, p. 978.

8 See G. Bischof, Lehrbuch der chemischen und physikalischen Geologie, 2d ed., vol. 3, p. 856. Also J. 

Margottet, Compt. Rend., vol. 85, 1877, p. 1142. 

« Econ. Geology, vol. 1, 1906, p. 649. 

' System of mineralogy, 6th ed., p. 20.
METALLIC ORES. 621

The natural arsenides, antimonides, and bismuthides of silver are 

imperfectly known. An arsenide, Ag3As, was described by H. Wurtz, 1 

under the name huntilite. Wurtz also reported an antimonide, 

animikite, Ag0Sb. Both minerals were found in the Silver Islet 

mine, Lake Superior. The commoner antimonide, dyscrasite, varies 

from Ag3Sb to Ag6Sb. 2 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 3 comes into contact with any other silver salt, or with the metal itself. As crystallized argentite it has been prepared in several ways. J. Durocher 4 

obtained it by the action of hydrogen sulphide upon silver chloride 

at high temperatures. J. Margottet 5 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 6 obtained the crystallized sulphide by 

the same process. F. Roessler 7 crystallized argentite and the selenide 

from solution in molten silver, and the selenide also from fused bismuth. C. Geitner,8 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, 0 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 10 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.

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 solui Eng. and Min. Jour., vol. 27,1879, pp. 55,124.

a The compound Ag3Sb 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; K. Macy, Zeitschr. physikal. 

Chemie, vol. 50,1904, p. 200; G. I. Petrenko, Zeitschr. anorg. Chemie, vol. 50,1906, p. 139, and T. Liebisch, 

Sitzungsb. Berlin Akad., 1910, p. 365. Petrenko cites other references.

a Dry hydrogen sulphide does not attack silver.

< Compt. Rend., vol. 32,1851, p. 825.

6 Idem, vol. 85,1877, p. 1142.

0 Annales chirn. phys., 3d ser., vol. 55,1859, p. 147.

7 Zeitschr. anorg. Chemie, vol. 9,1895, p. 31.

8 Liebig's Annalen, vol. 129, 1864, p. 358.

9 Zeitschr. Kryst. Min., vol. 17, 1890, p. 497.

10 Ber. Deutsch. chem. Gesell., vol. 16,1883, pp. 324,1002; vol. 17,1884, p. 1218.
622 THE DATA OF GEOCHEMISTRY.

tion, 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 folio wing, data, giving heats of formation from solid 

metal and solid sulphur, are furnished by Julius Thomsen. 1 The 

figures are for 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. 

Reactions of this class doubtless assist in the secondary enrichment of 

ore bodies, the silver being dissolved above and redeposited below.

In changes of this order the thermal values and also the differing 

solubilities of all the compounds taking part in the phenomena need 

to be considered, but the data are as yet imperfectly known.

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, Ag4Te, is 

a more doubtful substance. The synthesis of hessite by Margottet has 

already been mentioned. B. Brauner 6 also obtained it by the same

1 Thermochemische Untersuchungen, vol. 3,1883, p. 455.

2 See W. Skey, Trans. New Zealand Inst., vol. 3,1870, p. 225.

3 Econ. Geology, vol. 2,1907, p. 16.

< Jour, prakt. Chemie, 2d ser., vol. 41,1890, p. 414.

5 Trails. Am. Inst. Min. Eng., vol. 36,1906, p. 667.

6 Jour. Chem. Soc., vol. 55,1889, p. 388.
METALLIC OKES. 623

method. R. D. Hall and V. Lenher 1 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 tellurides, AgTe and Ag2Te have been prepared by G. Pellini and 

E. Quercigh. 2

Eucairite, CuAgSe; stromeyerite, CuAgS; sternbergite, AgFe2S3 ; 

and frieseite, Ag2Fe5S8; 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 

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 3 ..........Ag3SbS3 .........................Rhombohedral.

Pyrostilpnite.......... Ag3SbS3 .........................Monoclinic.

Tapalpite 4 ............Ag3BiTe3 .......................Massive.

Stephanite............Ag5SbS4 ........................Orthorhombic.

Pearceite............. Ag9AsSc .........................Monoclinic.

Polybasite............. Ag9SbS0 ......................... Orthorhombic.

Polyargyrite........... Ag24Sb2S15 ...................... Isometric.

Schapbachite.......... Ag2PbBi2S5 ...................... Orthorhombic.

Brongniardite......... Ag2PbSb2S5 ...................... Isometric.

Andorite............... AgPbSb3SG ...................... Orthorhombic.

Schirmerite.......... .(Ag2 ,Pb)3Bi4Sg..................Massive.

Diaphorite.............(Ag2 ,Pb)5Sb4S u ..................Orthorhombic.

Freieslebenite..........(Ag2 ,Pb)5Sb4S n ..................Monoclinic.

Several other sulphosalts of lead and copper also contain replacements of silver of considerable importance. Tennantite, Cu8As2S7 , 

contains up to 13.65 per cent of silver; and tetrahedrite, Cu8Sb2S7 , 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, Ag8SnS6 , 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 5 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 Senarmont, 0 by heating1 a

1 Jour. Am. Chem. Soc., vol. 24,1902, p. 919.

2 Atti Accad. Lincei, vol. 19, pt 2,1910, p. 415.

8 A manganiferous sulphantimonide of silver, samsonlte, allied to pyrargyrite, has been described by 

Werner and Fraatz, Centralbl. Min., Geol. u. Pal., 1910, p. 331. 

«Contains some sulphur partly replacing tellurium. 

» Compt. Rend., vol. 32, 1851, p. 825. 

0 Annales chim. phys., 3d ser., vol. 32,1851, pp. 171-173.
624 THE DATA OF GEOCHEMISTRY.

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 potassium 

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 SenarmomVs 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 polyargyfite, 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.

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 conditions are still unknown, 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

1 Compt. Rend., vol. 124,1897, p. 1518.

2 Allgem. chem. Mineralogie, p. 152.

3 Zeitschr. Kryst. Min., vol. 11,1886, p. 29.

4 Zeitschr. anorg. Chemie, vol. 15,1897, p. 173; vol. 18,1898, p. 42(X 

6 Jour, prakt. Chemie, 2d ser., vol. 41,1890, p. 414. 

«Zeitschr. anorg. Chemie, vol. 9,1895, p. 31.
METALLIC OEES. . 625

1 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 haloid ores of silver remain to be mentioned. These are 

represented 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; cuproiodargyrite 

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.

. 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.

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+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, and J. A. Burgess, idem, vol. 6,1911, p. 13. :

2 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.

101381° Bull. 491 11 40
626 THE DATA OF GEOCHEMISTRY.

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 bowlders 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 

has found that hornblende and siderite can precipitate metallic copper from a sulphate solution heated to 200°. Under certain conditions, 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

1 Am. Jour. Sci., 3d ser., vol. 38,1889, p. 405.

2 Prof. Paper U. S. Geol. Survey No. 43,1905, p. 101.

3 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, and Quart. Bull. Canadian Min. Inst., 

No. 13, 1911, p. 81. In the 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.

5 Econ. Geology, vol. 1,1906, p. 648..
METALLIC ORES. 627

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 +2H20 = 2Cu +S02 +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. Beck6 mentions native 

copper rilling 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 

Chinese copper coins of the seventh century A. F. Rogers 9 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.

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. Fernekes (Econ. 

Geology, vol. 2,1907, p. 581) has also described the precipitation of copper from neutral chloride solutions 

by FcCl2.

a Comp. 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.

« 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, 1890, p. 101) mentions impregnations, 

of copper in fossil wood in the Permian of Texas. Percy (Metallurgy, vol. 1,1875, p. 211) refers to a cupriferous peat in Wales which had actually been worked as an ore. Its ash contained about 3 per cent of 

copper.

»Am. Geologist, vol. 31, 1903, p. 43. Similar coins, probably from the same find, are in the collections 

of the United States National Museum.
628 THE DATA OP GEOCHEMISTRY.

Among the less important ores of copper there are three arsenides, 

an antimonide, some selenides, and a telluride. The arsenides are 

domeykite, Cu 3As; algodonite, Cu6As; and whitneyite, Cu 9As. 

Mohawkite is a domeykite containing several per cent of cobalt and 

nickel. Domeykite was produced artificially by G. A. Koenig, 1 who 

passed the vapor of arsenic over red-hot copper. Horsfordite is the 

antimonide, Cu6Sb. Two selenides are known, namely, berzelianite, 

Cu 2Se, and umangite, Cu 3Se 2 . Crookesite is a selenide of copper, 

silver, and thallium, and rickardite is the telluride, Cu4Te 3 . 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 formulae:

Chalcocite.................................................. Cu2S.

Covellite.................................................... CuS.

Chalcopyrite................................................ CuFeS2 .

Chalmersite 2 ................................................. CuFe2S3 .

Cubanite...................................................CuFe2S4 .

Bornite 3 .................................................... Cu5FeS4 .

To this list the rare cobalt copper sulphide, carrollite, CuCo 2S4 , 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 4 found it, 

together with bornite, thus formed, probably by sublimation, at 

Butte, Montana. On another product from the same locality, W. P. 

Headden5 discovered cubanite. Chalcopyrite was first prepared by 

J. Fournet, 6 who simply fused pyrite and copper sulphide together. 

F. de Marigny7 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,8 by the action of hydrogen sulphide upon the vapor 

of copper chloride, obtained copper sulphide in hexagonal tables. 

H. de Senarmont 9 heated a solution containing ferrous and cuprous

1 Am. Jour. Sci., 4th ser., vol. 10,1900, p. 439.

2 See E. Hussak, Centralbl. Min., Geol. u. Pal., 1906, p. 332. R. Schneider (Jour, prakt. Chemie, 2d ser., 

vol. 52,1895, p. 555) gives the formula here assigned to chalmersite to cubaaite.

a Formula as established by B. J. Harrington, Am. Jour. Sci., 4th ser., vol. 10,1903, p. 151. The older, 

commonly accepted formula is Cu3FeS3 .

* Am. Geologist, vol. 28,1901, p. 244.

5 Proc. Colorado Sci. Soc., vol. 8,1905, p. 39.

B Annales des mines, 3d ser., vol. 4,1833, p. 3.

' Compt. Rend., vol. 58,1864, p. 967.

s Idem, vol. 32,1851, p. 825.

9 Annales chim. phys., 3d ser., vol. 32,1851, p. 166.
METALLIC ORES. 620

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,1 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 

2CuO + Fe 203 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 2 

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.

At several of the French thermal springs, Bourbonne-les-Bains, 

Plombieres, etc., A. Daubree 3 found Roman coins and metals, upon 

which, derived from the bronze, chalcocite, chalcopyrite, bornite, and 

tetrahedrite 'had formed. Similar observations were made by C. A. 

de Gouvenain 4 at Bourbon-1'Archambault. E. Chuard 5 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 sulphide 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, 6 pyrite, chalcopyrite, bornite, chalcocite, and sometimes blende or galena, occur in serpentinized rocks as 

original segregations. Similar occurrences in Servia are reported by 

R. Beck and Baron W. von Fircks; 7 and in dioritic rocks at Ookiep, 

Namaqualand, by A. Schenck.8 In a pegmatite near Princeton, 

British Columbia, J. F. Kernp 0 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

1 Zeitschr. Kryst. Min., vol. 11,1886, pp. 34-36.

2 Idem, vol. 17,1890, p. 497.

8 Annales des mines, 7th ser., vol. 8,1875, p. 439; Compt. Bend., vol. 80,1875, p. 461; Etudes synthe'tiques 

de geologic expdrimentale, pp. 72-86. See also A. Lacroix, Bull. Soc. min., vol. 32,1909, p. 333.

< Compt. Rend., vol. 80,1875, p. 1297.

6 Idem, vol. 113,1891, p. 194.

8 Bull. Soc. geol. Belgique, vol. 3, Mem., 1889, p. 179. 

 i Zeitschr. prakt. Geologic, 1901, p. 321.

8 Zeitschr. Deutsch. geol. Gesell., vol. 53, Verhandl., 1901, p. 64. See also W. H. Weed, Eng. and Min. 

Jour., vol. 79,1905, p. 272.

9 Trans. Am. Inst. Min. Eng., vol. 31,1901, p. 182. See also J. Catherinet, Eng. and Min. Jour., vol. 79, 

1905, p. 125.
630 THE DA*A OF

also in veins, in contact zones, and as 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,1 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, 2 who treated cupriferous pyrite 

with dilute solutions of copper sulphate and sulphur dioxide and 

obtained films of cuprous sulphide. The sulphides of arsenic, lead, 

and zinc precipitated coppercsulphide from sulphate in the same way. 

Chalcocite is thus formed both from pyrite and zinc blende, according to W. Lindgren, 3 at Clifton and Morenci, in Arizona. Chalcocite 

itself alters into chalcopyrite, bornite, and covellite, 4 the last species 

being almost invariably of secondary origin.- Covellite heated with 

a solution of sodium bicarbonate was found by H. N. Stokes 5 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.6 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 

deposit in which they occur.7 No simple rules can be formed to cover 

all cases, and a part of the difficulty arises from the fact that many 

of the reactions are reversible.

Among the sulphosalts there are a number containing copper, as 

follows :

Chalcostibite. ............................................. CuSbS2 .

Emplectite. . ............................................ .CuBiS2 .

Stylotypite 8 .............................................. Cu3SbS3 . '

Bournonite. . ............................................ .CuPbSbS3 .

Wittichenite ............................................... Cu3BiS3 .

Aikenite ................................................... CuPbBiS3 .

1 Zeitschr. Kryst. Min., vol. 31, 1899, p. 508.

2 Bull. Geol. 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. 

s Prof. Paper U. S. Geol. Survey No. 43, 1905, pp. 182-186. 

< See Dana's System of mineralogy, 6th ed., p. 56.

5 Econ. Geology, vol. 2, 1907, p. 14.

6 Bull. U. S. Geol. Survey No. 186, 1900, p. 44.

* At Copper Mountain, British Columbia, according to Kemp (Econ. Geology, vol. 1, 1905, p. II), the 

original ore was bornite; and from that mineral covellite with limonite, then chalcocite, and finally chalcocite with chalcopyrite were successively derived. See also J. Catharinet, Eng. and Min. Jour., vol. 79, 

1905, p. 125.

8 Copper partly replaced by silver and iron.
METALLIC OSES. 631

Enargite................................................... Cu3AsS4 .

Famatinite....................:........................... Cu3SbS4 .

Tennantite................................................ Cu8As2S7 .

Tetrahedrite..............................................CugSb.jS?.

Klaprotholite.............................................. Cu6Bi4 S9 .

Epigenite 1 ............................................... .Cu7As2Si2 . '

Cuprobismutite........................................... Cu6Bi8S16 .

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 Cu 8Bi2S7 , 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. 2

R. Schneider 3 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 4 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 5 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 300°, Ii. Sommerlad 0 prepared chalcostibite. Another preparation, corresponding to Cu2Sb4S7 , was similarly obtained. By fusing together their 

component elements, in proper proportion, F. Ducatte 7 obtained 

emplectite, aikenite, and wittichenite.

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, 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. Hille1 Copper partly replaced by iron.

2 On the composition of tetrahedrite (fahlerz) see A. Kretschmer, Zeitschr. Kryst. Min., vol. 48,1910, p. 

484.

s Pogg. Annalen, vol. 127,1806, p. 316. 

«Jour, prakt. Chemie, 2d ser., vol. 40,1889, p. 564. 

& Zeitschr. Kryst. Min., vol. 11,1886, p. 38. 

« Zeitschr. anorg. Chemie, vol. 18,1898, p. 420. 

* Thesis, Univ. Paris, 1902.
632 THE DATA OF GEOCHEMISTRY.

brand 1 has identified olivenite, erinite, tyrolite, chalcophyllite, clinoclasite, 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, Cu 2 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, 2 

and also as an incrustation upon ancient objects of copper or bronze.3 

Both compounds are easily prepared synthetically. Crednerite is 

another oxidized compound, having the formula Cu 3Mn409 . An 

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.4 Several-syntheses of it have been reported. F. Field 5 

obtained atacamite by the action of calcium hypochlorite upon a solution of copper sulphate. C. Friedel 6 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. Tschermak7 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 chrysocoUa after atacamite have been described by C. Barwald.8

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, CuS04 .5H2 0; 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, 

Chile, according to H. Oehmichen,9 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. Lind1 Bull. U. S. Geol. Survey No. 20,1885, and No. 55,1889.

2 See, for example, A. Arzruni, Zeitschr. Kryst. Min., vol. 18,1891, p. 58.

3 In addition to cases already cited, see A. Lacroix, Bull. Soc. min., vol. 6, p. 175. 

* For a description of an atacamite ore body, see J. A. W. Murdoch, Trans. Inst. Min. Met., vol. 9,1901, 

p. 300.

6 Phil. Mag., 4th ser., vol. 24,1862, p. 123. . 

« Compt. Rend., vol. 77,1873, p. 211.

7 Jahrb. E.-k. geol. Reichsanstalt, vol. 23, Min. Mitt., p. 4L . 

s Zeitschr. Kryst. Min., vol. 7,1883, p. 169. 

9 Zeitschr. prakt. Geologic, 1902, p. 147.
METALLIC OSES. 633

gren 1 has called attention to its presence in the Clifton-Morenci mines 

of Arizona, where it occurs in fibrous forms which might easily be 

mistaken for malachite. F. Field 2 prepared brochantite artificially 

by boiling a solution of copper sulphate with a very smaU quantity 

of caustic potash. S. Meunier 3 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, Cu 2 (OH) 2C03 , and azurite, Cu 3 (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 4 prepared malachite

by heating precipitated copper carbonate with a solution of ammonium carbonate on a water bath during eight days. Later,5 upon 

heating a solution of copper carbonate in carbonated water, he obtained a precipitate of malachite. L. Michel 6 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.

Two silicates of copper, dioptase and chrysocolla, are well-known 

minerals. Dioptase, CuH2Si04 , is rare; chrysocolla, CuSi03 .2H2 0, is 

common. A. C. Becquerel 7 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 

copper. Possibly, also, it may be produced during processes of secondary enrichment. E. C. Sullivan 8 has shown that powdered shale, 

feldspar, 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 smaU quantities of the

1 Prof. Paper U. S. Geol. Survey No. 43,1905, p. 119.

2 Phil. Mag., 4th ser., vol. 24,1862, p. 123.

a Compt. Rend., vol. 80,1878, p. 686.

< Idem, vol. 110,1890, p. 202.

& Idem, vol. 122,1S9C, p. 1352.

« Bull. Soc. mm., vol. 13,1890, p. 139.

i Compt. Rend., vol. 67,1808, p. 1081.

8 Econ. Geology, vol. 1,1905, p. 67. Complete report in Bull. U. S. Geol. Survey No. 312,1907.
DATA OF &EOCHEM1STBY'.

precious metals can be determined by fire assay, but the volatility of 

mercury prohibits 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).

Lehrbachite............................................. HgSe+PbSe.

Livingstonite............................................ HgSb4S7

Montroydite.............................................HgO.

Calomel.................................................Hg?Cl2 . '

Terlinguaite.............................................Hg2C10.

Eglestonite.............................................Hg4Cl20.

To these must be added kleinite, a curious sulphate-chloride of 

one of the mercurammonium 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. Ginnabar 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 

time 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

derivatives of cinnabar, in the mines of Brewster County, Texas. 4 

Calomel has been found at several localities, but always as a secondary 

species.

1 Guadalcazarite is metacinnabarite containing a little zinc.

2 See G. F. Becker, Mon. U. S. Geol. Survey, vol. 13,1888, p. 385.

s 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. Min. 

and Met., vol. 4,1895, p. 69), H. F. Colliris (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.

4 See A. J. Moses, Am. Jour. Sci., 4th ser., vol. 16,1903, p. 253. Kleinite was erroneously described by 

A. Sachs, Sitzungsb. Akad. Berlin, 1905, p. 1091. Its true composition was first indicated by Hillebrand, 

Am. Jour. Sci., 4th ser., 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 County, 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, 

Bull. U. S. Geol. Survey No. 405,1910. On mosesite, see Hillebrand and Schaller, Am. Jour. Sci., 4th ser., 

vol. 30,1910, p. 202.
x METALLIC

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. 1 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 LeVy,2 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 3 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 hydrogen 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 4 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,5 amorphous mercuric sulphide, 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. 6 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

I A good summary of the individual methods for the preparation of vermilion is given in Watts' Dictionary of applied chemistry, vol. 2, article "Mercury."

II 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. 

8 Zeitschr. Kryst. Min., vol. 11,1886, p. 33. 

« Jahresber. Chemie, 1876, p. 282. 

5 Am. Jour. Sci., 3d ser., vol. 17,1879, p. 453. 

'Cornpt. Rend., vol. 98,1884, pp. 1271,1380.
636 THE DATA -OF GEOCHEMISTRY.

interpreted by Ditte, are rather complex, and involve the formation 

and decomposition of two double sulphides, K2HgS2 and K2Hg5S6 . 

The results are also modified by variations in temperature and in the 

concentration of the solutions employed. J. A. Ippen's 1 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 2 found that mercuric sulphide is very soluble in 

concentrated solutions of the alkaline sulphides, and also in the 

sulphides 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.

E. Weinschenk 3 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.

Finally, a crystalline mass resembling livingstonite was prepared 

by A. L. Baker,4 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.5 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,6 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

1 Min. pet. Mitt., vol. 14,1894, p. 114.

2 Annales Soc. g6ol. Belgique, vol. 18,1891, p. xxv.

3 Zeitschr. Kryst. Min., vol. 17,1890, p. 498.

* Cited by Dana, System of mineralogy, p. 110, from Chem. News, vol. 42,1880, p. 196.

5 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.

6 Am. Jour. Sci., 3d ser., vol. 33, 1887, p. 199. In detail, with full summaries of earlier work, in MOD. 

U. S. Geol. Survey, vol. 13,1888, chapter 15. Also, preliminary, in Eighth Ann. Rept. U. S. Geol. Survey, 

pt. 2,1889, p. 985.
METALLIC OEES. . 637

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 1 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 

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 2 to have the following composition :

Composition of gas at Phoenix mine.

co2 ::......... .............................................. 0.74

OH4 ..........'................................................. 61.49

JXa ........................................................... 31.44

0,.......................................................... 6. 33

100. 00

The hydrocarbon CH4 , it must be observed, is the first member of 

the paraffin series, to which some bitumens belong. Becker 3 has 

shown that hydrocarbons will precipitate mercuric sulphide from its 

alkaline solutions, first, probably, as metacinnabarite, which is afterwards slowly transformed into cinnabar. Another suggestion, due to 

A. Schrauf,4 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,5 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, in 

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.

1 Am. Jour. Sci., 3d ser., vol. 33, 1887, p. 199.

2 Mon. U. S. Geol. Survey, vol. 13,1888, p. 373.

a Mineral Resources U. S. for 1892, U. S. Geol. Survey, 1893, p. 139.

< Jahrb. K.-k. geol. Reichsanstalt, vol. 41, 1892, pp. 383, 396C Schrauf gives many citations of literature relative to mercury, and especially to the mines of Idria.

» Mon. TJ. 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.
638 THE DATA OF GEOCHEMISTRY.

The ores are commonly associated with pyrite or marcasite, sulp'nur, 

calcite, barite, gypsum, opal, quartz, and other secondary minerals, 

and show distinct evidence that they have been brought up from 

below in solution. 1 In many cases, if not in all, the evidence of 

hydrous or solfataric origin is very clear. A. Liversidge,2 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 3 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 4 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 evidenced At Idria A. Schrauf 5 

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. 6

1 In addition to Becker's monograph, see J. A. Phillips, Quart. Jour. Geoi. Soc., vol. 35, 1879, p. 390;

and J. Le Conte and W. B. Rising, Am. Jour. Sci., 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, p. 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. 403) those of British Columbia. For a recent study of the mercury mines at Mount Avala, Servia, 

see H. Fiseher, 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. 

Umlauff, Bol. Cuerpo ingen. minas Peru, No. 7,1904. F. Katzer (Berg- u. huttenm. 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 Belgiqne, vol. 9,1904, p. 35.

a 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 laterreport by J.M.Bell and E. de C. Clarke is in Bull. New Zealand Geol. Survey No. S, 1909, 

p. 87.

s Mon. U. S. Geol. Survey, vol. 13,1888, p. 344.

* 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.

5 .Tahrb. 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.
METALLIC OEGES. 639

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 black-jack when crystallized in the isometric system, 

or as wurtzite when it is hexagonal. Cadmium is found almost 

exclusively as the sulphide, CdS, or greenockite, which is also hexagonal. 1 Many massive blendes are really mixtures of sphalerite 

and wurtzite. 2 The rare mineral voltzite is an oxysulphide of zinc, 

4ZnS.ZnO.

Sphalerite, wurtzite, and greenockite have all been prepared synthetically, and wurtzite has been repeatedly observed as a furnace 

product.3 According to H. de Senarmont,4 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.5 

J. Durocher 0 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. Schuler 7 obtained crystals of greenockite. This 

observation has since been verified by R. Schneider. 8 . H. SainteClaire Deville and H. Troost 9 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 10 

when zinc or cadmium oxide was heated in the vapor of sulphur. In 

another paper 11 he states that amorphous zinc sulphide, heated in 

an atmosphere of nitrogen or of sulphur dioxide, crystallizes into 

wurtzite. P. Hautefeuille 12 heated zinc and cadmium sulphide 

under a layer of powdery alumina; the two compounds volatilized 

and were redeposited on the surface of the alumina as wurtzite or 

greenockite. He also found that blende, heated to redness, was

transformed into wurtzite. R. Lorenz 13 obtained wurtzite and

 

i A basic carbonate of cadmium and the crystallized oxide, CdO, are recently discovered minerals.

a See J. Noelting, Zeitschr. Kryst. Min., vol. 17, J890, p. 220.

a See W. Stahl, Berg- u. Mttenm. Zeitung, 1888, p. 207; H. Forstner, Zeitschr. Kryst. Min., vol. 5,3881, 

p. 363; and H. Traube, Neues Jahrb., Beil. Bd. 9,1894, p. 151.

* Compt. Rend., vol. 32,1851, p. 409. The description of the process is very vague.

B See L. Bourgeois, Reproduction artiflcielle des mine'ranx, p. 28.

« Compt. Rend., vol. 32,1851, p. 825.

i Liebig's Annalen, vol. 87,1853, p. 34.

s Pogg. Annalen, vol. 149.1873, p. 391.

» Compt. Rend., vol. 52,1861, p. 920. 

'«Idem, vol. 62, I860, p. 999.

» Idem, vol. 63,1866, p. 188. ' 

»Idem, vol. 93, 1881, p. 824. 

» Ber. Deutsch, chern. Gesell., vol. 24,1891, p. 1501,
640 THE DATA OF GEOCHEMISTRY.

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 1 heated metallic cadmium with sulphurous acid to 200° in 

a sealed tube. A mixture of amorphous and crystalline sulphide was 

deposited. A. Ditte 2 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.

For geological purposes these syntheses of blende and wurtzite are 

very suggestive. Blende is formed at relatively low temperatures, 

and at higher temperatures it is transformed into the hexagonal 

modification. An ore body containing wurtzite is therefore, probably, a product of relatively high temperatures. What these temperatures are and at what temperatures the transformation takes 

place remain to be determined. The hydrochemical syntheses of 

blende, furthermore, are paralleled by certain natural occurrences of 

the mineral. G. Bischof,3 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 4 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 5 .speaks of blende 

crystals, one-fourth inch across, which had grown on iron nails 

immersed in a mine water during fifteen years. W. P. Jenney6 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. 7 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 sin previous portions of this volume.8 An

1 Liebig's Annalen, vol. 129,1864, p. 350.

2 Compt. Rend., vol. 85,1877, p. 402.

3 Lehrbuch der chemischen und physikalischen Geologic, 2d ed., vol. 1, p. 559.

«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.

-'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 Mill. Jour., vol. 49,1890, p. 499. 

8 See ante, p. 177.
METALLIC ORES. 641

occurrence of sphalerite as a primary mineral in granite has been 

reported by E. Bimann.1

The oxidized compounds of zinc, as natural minerals, are fairly 

numerous. The following species are especially noteworthy:

Zincite...........................................ZnO.

Gahnite 2 ..........................................ZnAl204 .

Franklinite 2 ....................................... ZnFe204 .

Chalcophanite 2 ...................................Zn0.2Mn02 .2H20.

Smithsonite.......................................ZnC03 .

Hydrozincite......................................ZnC03 .2Zn02H2 . Willemite 3 .........................................Zn2Si04 .

Calamine........ 1..................................Zn2H2Si05 .

Clinohedrite.......................................ZnCaH2Si05 .

Hardystonite.....................................ZnCa2Si207 .

To this list may be added the phosphates, hopeite 4 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 need further mention except goslarite, ZnS04 .7H2O, 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.

Zincite, the natural oxide of zinc, is well known as a furnace product, and it has also been repeatedly synthetized.5 According to A. 

Daubre'e,6 when zinc chloride and water vapor act upon lime at a red 

heat, zincite is formed. Ferrieres and Dupont 7 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 8 was able to effect its crystallization. A. Gorgeu 9 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 10 obtained gahnite by fusing a

1 Zeitschr. prakt. Geologic, 1910, p. 123.

2 The formulae here given are ideal. Part of the zinc is commonly replaced by manganese or iron.

8 Troostite is a manganiferous willemite.

4 For a synthesis of hopeite, see C. Friedel and E. Sarasin, Bull. Soc. min., vol. 2,1879, p. 153.

6 See H. Traube, Neues Jahrb., Bell. Bd. 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, Min. Mag., vol. 9,1892,

p. 5. L. Bourgeois (Reproduction artificielle des mineraux) 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.

6 Compt. Rend., vol. 39,1854, p. 135.

' See Bourgeois, op. cit., p. 56.

8 Compt. Rend., vol. 69,1869, p. 201.

 Idem, vol. 104,1887, p. 120.

10 Annales chim. phys., 3d ser., vol. 33,1851, p. 34.

101381° Bull. 491 11 41
642 THE DATA OF GEOCHEMISTRY.

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. 

Daubree 1 prepared gahnite; and franklinite was similarly produced 

by using the chlorides of iron and zinc. H. Sainte-Claire Deville 

and H. Caron 2 obtained gahnite by vaporizing a mixture of zinc 

and aluminum fluorides in presence of boric oxide. A. Stelzner 3 

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 4 report the formation of willemite and tridymite. The I 

occurrence of crystallized willemite in a fujnace slag has also been 

recorded by W. M. Hutchings.5 \

According to A. Daubre'e, 1 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, 6 who found that willemite was decomposed by silicon chloride. It is formed when silicon j 

fluoride acts upon zinc oxide, and also by the action of zinc fluoride 

upon heated silica. A. Gorgeu 7 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 8 obtained crystals of smithsonite. G. Bischof 9 

cites 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 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 10 detected zinc in

1 Compt. Rend., vol. 39,1854, p. 135.

2 Idem, vol. 46,1858, p. 766.

» Neues Jahrb., pt. 1,1882, p. 170.

< Idem, pt. 1,1881, p. 120.

6 Geol. Mag., 3d ser., vol. 7,1890, p. 31.

<> Compt. Rend., vol. 52,1861, p. 1304.

' Idem, vol. 104,1887, p. 120.

s Reproduction artificielle des mineraux, p. 144.

9 Lehrbuch der chemischen und physikalischen Geologie, 2d ed., vol. 1, p. 561.

10 Compt. Rend., vol. 90,1880, p. 1573, and vol. 96,1883, p. 70.
METALUEC ORES. 643

hundreds of samples of Jurassic limestone from central France. J. D. 

Robertson 1 found it, with lead and copper, in the limestones of Missouri, and J. B. Weems 2 determined lead and zinc in 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, zine, and copper in limestones.

Lead. .................................

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

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.3

Similar results to those of Weems and Robertson were obtained 

by A. M. Finlayson 4 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 

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, 

have percolated downward and been reduced to sulphide again. It

i Missouri Geol. Survey, vol. 7,1894, pp. 479-481.

a Cited by S. Calvin and H. F. Bain, Iowa Geol. Survey, vol. 10,1900, p. 566.

 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. 

< Quart. Jour. Geol. Soc., vol. 66,1910, p. 299.
644 THE DATA OF GEOCHEMISTRY.

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 from 

4 or 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 

deposited from solution, which is the essential fact for the geochemist to consider.4

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

1 Econ. Geology, vol. 2,1907, p. 17. See also the work of Anthon, Schurmann, and others, already cited 

on p. 612, ante.

2 See W. H. Seamon, Am. Jour. Sci., 3d ser., vol. 39, 1890, p. 38; and J. C. Branner, Ann. Kept. Geol. 

Survey Arkansas, vol. 5,1892, pp. 9-34. Both authors give analyses, and other analyses by T. M. Chatard 

and 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 percent ZnO, was described by B. H. Heyward, Chem. News, vol. 44,1881, p. 207.

s Mon. U. S. Geol. Survey, vol. 12,1886, p. 603.

4 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; Bam, Van Hise, and Adams, Twenty-second Ann. 

Rept. 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. Rept. Geol. Survey Arkansas, 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 recent publications are by E. Haworth and others, Kansas Univ. Geol. Survey, vol. 8,1904; E. R. 

Buckley and H. A. Buehler, Missouri Bur. Geol. and Mines, 2d ser., vol. 4,19Q6; 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. On the genesis of the Ozark deposits, see C. R. Keyes, 

Bull. Am. Inst. Min. Eng., 1909, p. 119.
METALLIC OEES. 645

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 miheralogical 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,1 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.2

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.3

The principal ore of lead is the normal sulphide, galena, PbS. 

Allied to this are the rare selenide, clausthalite, and altaite, the corresponding telluride.4 The synthetic preparation of galena has been 

effected by various methods, both wet and dry. J. Durocher 5 

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 to 

T. Sidot,6 when heated in the vapor of sulphur, yields galena. F. 

Stolba 7 produced crystals of the sulphide by heating the amorphous 

compound to dull redness with chalk. F. de Marigny 8 produced 

galena by fusing litharge with iron pyrites and starch. F. Roessler 9 

crystallized both galena and clausthalite from solution in molten

1 Trams. Am. Inst. Min. Eng., vol. 24,1895, p. 187.

2 For data regarding the Franklin region, see F. L. Nason, Ann. 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.

s A. Hamberg (Zeitschr. Kryst. Min., vol. 17,1890, p. 253) has suggested that at Harstig, Sweden, the 

lead was reduced by arsenious oxide.

« Nagyagite is a sulphotelluride of lead, gold, and antimony. Naumannite, lehrbachite, and zorgite are 

selenides of lead with silver, mercury, or copper.

s Compt. Rend., vol. 32,1851, p. 825. See also A. Carnot, cited by L. Bourgeois, Reproduction artlficielle des minfiraux, p. 30.

" Compt. Rend., vol. 62,1866, p. 999.

i Jahresber. Chemie, 1863, p. 242.

s Compt. Rend., vol. 58,1864, p. 967.

9 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.
646 THE DATA OF GEOCHEMISTRY.

lead. By distillation of a mixture containing lead oxide, sulphur, 

and ammonium chloride, E. Weinschenk1 also prepared crystals of 

galena. 'It is furthermore to be noted that galena is not uncommon 

in furnace slags, and that Mayencon2 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 

hydrochemical reactions, and these can be imitated in the laboratory. 

C. Doelter 3 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. Weinschenk4 heated a solution of lead nitrate with 

ammonium sulphydrate to 180° in a sealed tube and also obtained 

galena. H. N. Stokes 5 has found that pyrite or marcasite, heated 

with a solution of lead chloride to 180°, will precipitate lead sulphide. A. Daubre'e 6 observed the formation of galena, together with 

anglesite and phosgenite, by the action of the thermal waters of 

Bourbonne-les-Bains on metallic lead. Lead sulphide is also known 

in spring deposits,7 and as a pseudomorphous replacement of other 

minerals. W. Lindgren8 mentions replacements of calcite, dolomite, 

and quartz, and also of orthoclase and rhodonite. W. H. Hobbs 9 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.10 A. Gautier 11 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.12 Sarto1 Zeitschr. Kryst. Mm., vol. 17,1890, p. 489. 

" Compt. Rend., vol. 86,1878, p. 491.

s Zeitschr. Kryst. Min., vol. 11,1886, p. 41. A. C. Becquerel (Compt. Rend., vol. 44,1857, p. 938), mentions a hydrochemical synthesis of galena, but too vaguely to warrant citation above.

« Idem, vol. 17,1890, p. 497. '

5 Econ. Geology, vol. 2,1907, p. 22.

6 Etudes synthe'tiques de g6ologie exp6rimentale, pp. 84,85.

f See, for example, the sinter described by G. F. Becker and W. H. Melville, Mon. U. S. Geol. Survey, 

vol. 13,1888, p. 344.

s Trans. Am. Inst. Min, Eng., vol. 30,1900, p. 578. 

s Am. Jour. Sci., 3d ser., vol. 50,1895, p. 121. 

10 Min. pet. Mitt., vol. 11,1890, p. 319. 

» Compt. Rend., vol. 142,1906, p. 1465.

12 Bournonite and aikinite, which contain both lead and copper, have already been mentioned under the 

latter metal.
METALLIC ORES. 647

rite, dufrenoysite, guitermanite, jordanite, rathite, and lengenbacliite 

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,1 zinkenite, PbSb2S4, can be prepared by 

fusing galena and stibnite together in proper proportions. C. Doelter,2 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 3 reproduced boulangerite, Pb3Sb2S0 ; zinkenite; jamesonite; warrenite 4 (domingite), 

Pb3Sb4S9 ; and plagionite, Pb5Sb8S17 . By fusing lead sulphide and 

arsenic trisulphide together, he obtained sartorite (scleroclase), 

PbAs2S4 , and dufrenoysite, Pb2As2S5 . Whether any of these syntheses correspond 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.

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, 5 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.

i Cited by L, Bourgeois, Reproduction artificielle des mine'raux, p. 40, from Jour, prakt. Chemie, vol. 2, 

p. 490.

a Zeitschr. Kryst. Min., vol. 11,1886, p. 40.

' 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.

«According to L. J. Spencer (Min. 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.

6 Compt. Rend., vol. 34,1852, p. 29. See also, for other researches, L. Bourgeois, Reproduction artificielle 

des mine'raux, p. 56. L. Michel (Bull. Soc. min., vol. 13, 1890, p. 56) reports syntheses of minium and 

plattnerite.
648 THE DATA OF GEOCHEMISTRY.

Lead carbonate, cerusite, PbC03, is a common mineral, produced 

by the action of carbonated waters in the upper levels of ore bodies. 1 

There are also the basic hydrocerusite, Pb3 (OH) 2 (C03) 2 , and the rare 

dundasite, a carbonate of aluminum and lead. 2 Becquerel 3 obtained 

crystals of cerusite when a solution of sodium and calcium carbonate 

acted gradually upon a plate of lead. E. Fre'my 4 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.5 

H. von Dechen 6 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 7 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. 8 The rare chlorocarbonate of lead, phosgenite, Pb2Cl2C03, was reproduced by C. 

Friedel and E. Sarasin 9 when lead chloride, lead carbonate, and 

water were heated together in a sealed tube to 180°. It was also 

prepared by A. de Schulten, 10 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.

Cotunnite, lead chloride, PbCl2, is found in nature as a volcanic 

mineral, produced by sublimation. F. Stober u 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, 12 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, Pb302Cl2, have long been known. Schwartzembergite 

is like mendipite in composition, but with iodine largely replacing

1 A large deposit of cerusite in the Terrible mine, at Use, Colo., has recently 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.

2 See G. T. Prior, Mineralog. Mag., vol. 14,1906, p. 167.

* Loc. cit.

4 Compt. Rend., vol. 63,1866, p. 714.

s 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. 

<> Neues Jahrb., 1858, p. 216.

* Bull. Soc. min., vol. 6,1883, p. 175.

<> See Blode, Neues Jahrb., 1834, p. 638.

9 Bull. Soc. min., vol. 4,1881, p. 175. 

1° Idem, vol. 20,1897 ,p. 194.

« Bull. Acad. Belgique, 3d ser., vol. 30,1895, p. 345. 

w Compt. Rend., vol. 34,1852, p. 29.
I METALLIC ORES. 649

chlorine. Laurionite,1 paralaurionite, penfieldite, daviesite, and fiedj lerite 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, 

,1 but with silver chloride as an additional component. 2 

j Lead sulphate, PbSO4 , as the crystallized mineral anglesite, is a 

common oxidation derivative of galena. According to E. Jannetaz 3 

galena is easily attacked by acid solutions of ferrous sulphate such as 

/ are generated by the oxidation of pyrite or marcasite. The association of galena with pyrite, therefore, is favorable to the formation 

of anglesite. Its synthesis by Becquerel has already been mentioned, 

/ and it has also been prepared by Mace1 ,* who added a solution of fer- 

< rous sulphate very slowly to one of lead nitrate. Essentially the 

'j same process was successfully followed by E. Fremy 5 and by E. 

/ Masing," a soluble sulphate being allowed to diffuse very slowly into 

j one of a lead salt in Masing's case lead nitrate. Lead sulphate, 

'j although relatively insoluble, is not absolutely so; it therefore can 

I be crystallized, as the syntheses show, when it is formed with extreme 

/ slowness in very dilute solutions. Conditions of the sort probably 

j attend the formation of anglesite in bodies of lead ore; but when car- 

« bonates are present in the percolating waters, cerusite is produced 

instead. The synthesis of anglesite by N. S. Manross,7 who obtained 

j 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, Pb2S05 .8 Caledonite 

and linarite are basic sulphates of lead and copper, and plumbojarosite is another basic sulphate 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,9 it occurs as a pseudomorph 

f . after calcite and galena. In composition it suggests a double salt 

| formed by the union of hydrocerusite and anglesite, hi equimolecular 

I proportions.10 Plumbojarosite, a highly hydrated sulphate of lead 

and iron, is abundant in some mines in Utah.

1 For a synthesis of laurionite, PbOHCl, see A. de Schulten, Bull. Soc. mln., vol. 20,1897, p. 186. On the 

rare minerals of Laurium, see A. Lacroixand De Schulten, Bull. Soc. mln., vol. 31,1908, p. 79. Georgiadesite, 

a phosphate and chloride of lead, should be added to the list.

2 Percylite, cumengeite, and boleite have been made artificially by C. Friedel, Bull. Soc. min., vol. 15, 

1892, p. 96; vol. 16,1893, p. 187; and vol. 17,1894, p. 6. See also, in reference to these minerals, E. Mallard, 

Bull. Soc. min., vol. 16,1893, p. 184, and G. Friedel, idem, vol. 29,1906, p. 14.

a Bull. Soc. gfiol. France, 3d ser., vol. 3,1875, p. 310. 

A < Compt. Rend., vol. 36,1853, p. 825. 

o Idem, vol. 63,1866, p. 714. 

o Jahresber. Chemie, 1889, p. 4.

7 Liebig'a Annalen, vol. 82,1852, p. 348.

8 For a synthesis of lanarkite, see A. de Schulten, Bull. Soc. min., vol. 21,1898, p. 142. 

0 Am. Jour. Sci., 3d ser., vol. 50,1895, p. 99.

10 Palmierite, a double sulphate of lead and potassium, is found among the recent products of fumarole 

action at Vesuvius.
650 THE DATA OP GEOCHEMISTRY.

Lead salts analogous to anglesite are the chromate, crocoite, 

PbCrO4 ; the molybdate, wulfenite, PbMoO4 ; and the tungstate, stolzite, PbWO4 . The rare phcenicochroite x is a basic chromate, 

Pb3Cr2 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,2 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 3 is probably due to some reaction of this kind. 

By slow diffusion of solutions of potassium chromate and lead nitrate 

into one another A. Drevermann 4 obtained both crocoite and phcenicochroite. Cerussite and anglesite were formed at the same time 

from impurities in the reagents. A. C. Becquerel 5 allowed a galvanic couple of lead and platinum to act for several years upon a 

solution of chromic chloride and secured crystals which appeared 

to be crocoite. S. Meunier 8 found that phcenicochroite was formed 

when fragments of galena were immersed during six months in a 

solution of potassium dichromate. L. Bourgeois 7 boiled precipitated 

lead chromate with dilute nitric acid. From the hot, filtered solution crystals of crocoite were deposited. Better results were obtained 

when the operation was conducted in a sealed tube at 130°. Lachaud 

and Lepierre 8 state that when amorphous lead chromate is boiled 

with a solution of chromic acid it crystallizes into crocoite. Phosnicochroite was formed when lead chromate and sodium chloride were 

fused together. Both chromates were obtained by Liideking 9 upon 

exposing to the air during several months a solution of lead chromate 

in caustic potash. Of all these syntheses, that by Meunier seems 

best to represent the probable natural processes.

Three lead minerals, the chloro-phosphate, pyromorphite, 

Pb5P3O12Cl; the corresponding arsenate, mimetite, Pb5As3012Cl; and 

the vanadium salt, vanadinite, Pb5V3012Cl, occur both independently 

and in a 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.

1 Also called melanochroite.

2 Liebig's Annalen, vol. 82, 1852, p. 348. H. Schultze (idem, vol. 126,1863, p. 51) prepared wulfenite in 

the same way.

3 See J. F. L. Hausmann, idem, vol. 81,1852, p. 224.

«Idem, vol. 87,1853, p. 120; vol. 89,1854, p. 11.

o Compt. Rend., vol. 63,1866, p. 1.

8 Idem, vol. 87,1878, p. 656.

' Bull. Soc. min., vol. 10,1887, p. 187.

8 Bull. Soc. chim., 3d ser., vol. 6,1891, p. 230.

s Am. Jour. Sci., 3d ser., vol. 44, p. 57.
METALLIC ORES. 651

All these species have been prepared synthetically, and pyromorphite is also known as a furnace product in slag.1 N. S. Manross 2 

obtained pyromorphite by fusing lead chloride with tribasic sodium 

phosphate. H. Sainte-Claire Deville and H. Caron 3 fused lead phosphate, lead chloride, and sodium chloride together to produce pyromorphite, and L. Michel 4 accomplished the same purpose by the 

same process, only omitting the common salt. From fusions of lead 

arsenate with lead chloride G. Lechartier 5 and also Michel succeeded 

in reproducing mimetite. Vanadinite was obtained by P. Hautefeuille 6 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,7 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,8 descloizite, 

cuprodescloizite, brackebuschite, and psittacinite. Bindheimite is a 

lead antimonate, formed by oxidation from sulphosalts of lead. 

Nadorite, PbClSbO2 , and ochrolite, Pb6Cl2Sb2O7 , 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 roeblingite, however, from the zinc mines at Franklin, New Jersey, is unique in contaming 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 9 and also by H. A. Wheeler. 10

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

i J. J. Nb'ggerath, Neues Jahrb., 1847, p. 37. 

* Liebig's Annalen, vol. 82,1852, p. 348. 

a Annales chim. phys., 3d ser., vol. 67,1803, p. 451. 

< Bull. Soc. min., vol. 10,1887, p. 133. 

s Compt. Rend., vol. 65,1867, p. 172. 

o Idem, vol. 77,1873, p. 896. 

' Annales chim. phys., 3d ser., vol. 61,1861, p. 443. 

8 Phosphate, arsenate, and sulphate of lead. 

» Am. Jour. Sci., 3d ser., vol. 30,1885, p. 138. 

«Idem, vol. 32,1886, p. 272.
652 THE DATA OF GEOCHEMISTRY.

than lead, and, for the same reason, so does copper. The lead ores 

of Eureka, Nevada, are regarded by J. S. Curtis * as the product of 

solfataric action; those of Leadville, Colorado, according to S. F. 

Emmons,2 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.

TIN.3

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.4 The ore of chief importance is the 

dioxide, cassiterite, Sn02 , but several sulphosalts are also known. 

They are 

Stannite............................................ .Cu2FeSnS4 .

Teallite 5 ...........................................PbSnS2 .

Cylindrite.......................................... Pb3FeSn4Sb2S14 .

Franckeite............................................ Pb5FeSn3Sb2Su.

There is also a very rare borate of calcium and tin, nordenskioldine,6 CaSnB2O6 , 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.7 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.8

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 9 and J. H. L. Vogt,10 and L. Bourgeois 11 has identified the mineral in scoria from a bronze foundry. 

The first synthesis of cassiterite was performed by A. Daubr6e 12 when 

the vapor of stannic chloride was mixed with steam in a red-hot

1 Mon. U. S. Geol. Survey, vol. 7,1884, chapters 7,8.

2 Idem, vol. 12,1886, p. 378.

3 For a paper on the occurrence and distribution of tin, with a bibliography, see F. L. Hess and 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 Eesources U. S. for 1883-84, U. S. Geol. Survey, 1885, pp. 592 et seq.

< A recent discovery of native tin is noted by E. S. Simpson in Ann. Rept. Geol. Survey West Australia, 

1899, p. 52.

5 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., pt. 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.

8 Described by W. C. Brogger, Zeitschr. Kryst. Min., vol. 16,1890, p. 61.

' See A. Knopf and W. T. Schaller.Am. Jour. Sci., 4th ser., vol. 25,1908, p. 323. Also Schaller, idem, 

vol. 29,1910, p. 543.

8 See A. Stelzner and A. Schertel, Jahrb. Berg- u. Hvitt. Ko'nig. Sachsen, 1886, p, 52, on tin in biack 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.

9 Zeitschr. Kryst. Min., vol. 25,1896, p. 467. 

i° Idem, vol. 31,1899, p. 279. 

" Bull. Soc. min., vol. 11,1888, p. 58. 

» Compt. Rend., vol. 29,1849, p. 227.
METALLIC ORES. 653

porcelain tube. Later the same chemist 1 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. Caron 2 

when stannic fluoride and boric oxide were heated together to whiteness. H. Sainte-Claire Deville 3 also obtained it by heating the 

amorphous oxide in a slow current of hydrochloric acid gas and 

again by a repetition of DaubreVs first process. A. Ditte 4 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,5 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 0 found 

0.5 per cent of Sn02 in an opaline deposit, resembling geyserite, from a 

thermal spring in Selangor. J. H. Collins 7 reports tinstone as a 

cement in certain Cornish conglomerates, as an impregnation in longburied horns of deer, as pseudomorphs after feldspar 8 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 9 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 Guanojuato, Mexico, has been described by E. Wittich.10

Cassiterite has been noted as an original constituent of igneous 

rocks 11 but it more commonly occurs in veins or stringers of quartz,

i Compt. Rend., vol. 39,1854, p. 135.

« Idem, vol. 46,1858, p. 764. Details :iot given.

8 Idem, vol. 53,1861, p. 161.

< Idem, vol. 96,1883, p. 701.

» Min. pet. Mitt., vol. 11,1890, p. 325.

«Compt. Rend., vol. 110,1890, p. 1083.

 > Mineralog. Mag., vol. 4,1880, pp. 1,103, and vol. 5,1883, p. 121.

8 According to C. Reld and J. B. Scrivenor (Mem. Geol. Survey Eng. and Wales, Geology of country near 

Newquay, 1906, p. 39), the so-called pseudomorphs are replacements 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. MacAlister, 

idem, Geology of Falmouth, Truro, etc., p. 167.

» Proc. Am. Philos. Soc., vol. 24,1887, p. 23, L. V. Pirsson (Am. Jour. Scl., 3d ser., vol. 42,1891, p. 407), 

has described crystals of hematite Inclosing cassiterite, from the same locality.

10 Zeltsch. prakt. Geologie, 1910, p. 121.

11 See ante, p. 335, in chapter on rock-forming minerals.
654 'THE DATA OF GEOCHEMISTRY.

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,1 and at certain Mexican 

mines; but at other localities of tin in Mexico the prevailing rock is 

rhyolite or rhyolite tuff. In these instances, as at the Potrillos mine, 

in Durango, the ore is found along fault planes in the rhyolite.2 

The Cacaria mine, also in Durango, is in quartz porphyry. In the 

Malay Peninsula, according to R. A. F. Penrose,3 the prevalent 

stanniferous rocks are granitic, 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.

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 

in a dike of elseolite 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 sometimes by the lithia-bearing phosphates triphylite and

1 On Tasmanian tin depositssee L. K. Ward, Bull. Geol. Survey Tasmania, No. 6,1909. Earlierseparate 

papers by G. A. Waller and W. H. Twelvetrees were issued by the same office. On the Mount Bischofl 

mines, see W. von Fircks, Zeitschr. Deutsch. geol. Gesell., vol. 51,1899, p. 431.

2 See C. 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.

s Jour. Geol., vol. 11,1903, p. 135. On the ores of Banca and Billiton, see R. Beck, Zeitschr. prakt. Geologie, 1898, p. 121. W. R. Rumbold (Bull. Am. Inst. Min. Eng., September, 1906) has described the tin 

depositsof the Kinta Valley, Malay States. He mentions deposits in limestone.
METALLIC ORES. 655

amblygonite.1 In some localities formerly worked for tin the lithia 

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,2 and A. Knopf,3 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,4 the ore is in quartz veins in granite, the walls 

of the veins being converted into greisen. W. H. Weed 5 and G. B 

Richardson 6 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,7 may also 

belong to this class. The vein material consists almost wholly of 

tourmaline and quartz, formed by gradual replacement of the granite 

walls.

Another mode in 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,8 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

1 For discussions on the genesis of cassiterite veins see A. Daubrfie, Etudes synthdtlques de gfiologie 

experimentale, pp. 28-71; J. H. L. Vogt, Zeitschr. prakt. Geologic, 1895, p. 145, and Trans. Am. Inst. Min. 

Eng., vol. 31,1901, p. 125; and W. Lindgren, idem, vol. 30,1900, p. 578. See also F. Cautier, Actes Soc. scl. 

Chili, vol. 5,1895, p. 82. R. Recknagel (Trans. Geol. 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.

* 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.

a 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.

5 Bull. U. S. Geol. Survey No. 178, 1901, and also in Bull. No. 213,1902, p. 170.

o Bull. U. S. Geol. Survey No. 285, 1905, p. 146.

' Am. Jour. Sci., 4th ser., vol. 4,1897, p. 39.

s Bull. U. S. Geol. Survey No. 293, 1906, and also in Bull. No. 2CO, 1904, p. 188. Other papers on the 

Carolina belt are by J. H. Pratt, Mineral Resources U. S. for 1903, U. S. Geol, Survey, 1904, p. 337, and 

Pratt and D. B. Sterrett, Bull. North Carolina Geol. Survey No. 19,1904.
656 THE DATA OF GEOCHEMISTRY.

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. 1 Cassiterite 

in pegmatite, accompanied by corundum, is reported by P. F. 

Molengraaf 2 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 3 the rock is commonly dacite or trachyte; but at Potosi, 

as described by A. F. Wendt,4 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. E. Rumbold,5 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 casss 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 2 , and leucopyrite, Fe3As 4 , 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, allemoni See W. P. Blake, Trans. Am. Inst. Min. Eng., vol. 13,1885, p. 691. On the Black Hills mines, see also 

E. W. Claypole, Am. Geologist, vol. 9,1892, p. 228, and J. D. Irving, Prof. Paper U. S. Geol. Survey No. 26, 

1904, p. 95.

* See abstract in Zeitschr. prakt. Geologie, 1900, p. 146.

' Zeitschr. Deutsch. geol. Gesell., vol. 49,1897, p. 51. See also M. Frochot, Annales des mines, 9th ser., 

vol. 19,1901, p. 186.

«Trans. Am. Inst. Min. Eng., vol. 19, 1890, p. 90.

oEcpn. Geplpgy, vol. 4,1909, p. 321.
METALLIC ORES. 657

tite, SbAs3 , may be grouped. There are also natural sulphides, 

selenides and tellurides, as follows:

Realgar...................................................... AsS.

Orpiment.................................................... As2S3 .

Stibnite..........'............................................ Sb2S3 .

Metastibnite................................................ Sb2S3 .

Bismuthinite................................................ Bi2S3 .

Guanajua.tite................................................ Bi2Se3 .

Tetradymite................................................. Bi2Te3 .

Joseite'..................................................... Bi2Te.

Wehrlite 1 ................................................ .Bi3Te2 .

Grunlingite..................................................Bi4TeS3 .

Kermesite................................................... Sb2S20.

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. Weinschenk 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

> Formulae approximate only. Sulphur or selenium partly replaces tellurium.

2 Compt. Eend., vol. 32,1851, p. 825.

s Annales chim. phys., 3d ser., vol. 32,1851, p. 129.

< Zeitscbr. Kryst. Min., vol. 17,1890, p. 497.

6 See L. Bourgeois, Reproduction artiflcielle des mineraux, pp. 41,42. 

« Compt. Rend., vol. 86,1878, p. 491; vol. 92,1881, p. 854.

7 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. HOC.

8 Min. pet. Mitt., vol. 11,1890, p. 322.

" Am. Jour. Sci., 3d ser., vol. 42,1891, p. 401. At another spring in the Park, Arnold Hague (idem, voh 

34,1887, p. 171) found a deposit of scorodite, an arsenate of iron. 

«o Mon. U. S. Geol. Survey, vol. 13,1888, p. 344.

101381° Bull. 491 11 42
658 THE DATA OF GEOCHEMISTRY.

I

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 ....................................................... . 0720

CuS... ...................................................... .0424

Sb2S3+As2S3 ..... . ........................................... 78. 0308

. ................. ................................... 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 gyp^ 

sum.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 hi 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 ultimately associated with quartz. It is 

so found in the mines of Sevier County, Arkansas; 7 in Mexico, and in 

Corsica, where the ore bodies occur in sericitic schists. At Kostainik, 

in Servia, according to R. Beck and W. von Fircks,8 the stibnite is

1 Trans. Am. Inst. Min. Eng., vol. 36, 1906, p. 27.

2 Op. cit.,p. 389.

» B. Lotti, Zeitschr. prakt. Geologic, 1901, p. 43. 

< J. G. Aguilera, Trans. Am. Inst. Min. Eng., vol. 32, 1902, p. 307. 

5 Nentien, Annales des mines, 9th ser., vol. 12, 1897, p. 251. 

n Bull. Soc. geol. France, 2d ser., vol. 6, 1848-49, p. 91.

i See C. E. Wait, Trans. Am. Inst. Min. Eng., vol. 8, 1879, p. 42; J. C. Branner, Ann. Kept. Geol. Survey 

Arkansas, 1888, vol. 1, p. 136; and G. H. Ashley, Proc. Am. Philos. Soc., vol. 36, 1897, p. 306. 

8 Zeitschr. prakt. Geologic, 1900, p. 33.
METALLIC ORES. 659

found in trachyte, in graywacke, and also as replacements in limestone. 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..................................... -H2Sb205

Bismuth also forms two basic carbonates, bismutite and bismutosphaerite, and a rare oxychloride, daubre"eite. The oxides of antimony 

form important ore bodies at Altar, Sonora, Mexico,4 and in Neocomian limestone at Mount Hamimat, province of Constantine, Algeria.5

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, pharmacolite is an arsenate of lime, pharmacosiderite an 

arsenate of iron, and sarkinite an arsenate of manganese. Atopite 

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, 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, Fe2Sb2 07 , are found in the cinnabar-bearing gravels 

of Tripuhy, Brazil. 8 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 arsenic mine at Brinton, 

Virginia. For the antimony mines of Nova Scotia, see W. R. Askwith, Canadian Min. Rev., vol. 20,1901, 

p. 173.

2 The true molecular weight, as shown by the vapor density, is more probably represented by the formula 

As&e. A similar doubling may be proper for the other oxides and sulphides of this group.

3 On tho composition of bismuth ocher, see W. T. Schaller, Jour. Am. Chem. Soc., vol. 33,1911, p. 1C2.

« E. T. Cox, Am. Jour. Sci., 3d ser., vol. 20,1880, p. 421.

6 Coquand, Bull. Soc. g6ol. France, 2d ser., vol. 9, 1851-52, p. 342.

" See E. Hussak and G. T. Prior, Mineralog. Mag., vol. 11,1895, pp. 80,170, 302.
660 THE DATA OF GEOCHEMISTRY.

NICKEL AND COBALT. 1

Among the minor constituents of igneous rocks, nickel is one of 

the commonest. Cobalt also is 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 metepric 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 ................... (FeNi)S.

Jaipurite...................... CoS.

Linnseite....................... Co3S4 .

Smaltite........................ CoAs2 .

Safflorite....................... CoAs2 .

Skutterudite 5 .................. CoAs3 .

Cobaltite....................... CoAsS.

Carrollite....................... Co,CuS,

With these minerals we may include the nickel telluride, melonite, 

and the antimonide, breithauptite, NiSb. Ullmannite is a sulphide 

of antimony and nickel,7 NiSbS. Corynite and wolfachite are mixtures 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.

J.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. On 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. Geologie, 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. Geologie, 1906, p. 294) has 

described tourmaline-bearing cobalt veins at San Juan, Atacama, Chile. The ore is cobaltite.

2 On the wide diffusion of cobalt and nickel in nature, see K. Kraut, Zeitschr. angew. Chemie, 1906, p. 1793.

3 See ante, p. 314.

«The Sudbury polydymite is very nearly NijFeSs.

6 There is also a variety containing much nickel replacing cobalt. Bismutosmaltite, Co(AsBi)3, is a 

related mineral.

e Another nickel-iron sulphide has been called gunnarite. Its formula is near FesNisSs- Still another, 

akin to pentlandite, is the incompletely described heazlewoodite.

7 A similar sulphide, with bismuth partly replacing antimony, has been named kallilite.
METALLIC OBES. 661

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. H. de Senarmont 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. Weinschenk 4 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 bs 

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 0 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,9 T. L. Walker, 10 A. P. Coleman, 11 

D. H. Browne,12 and others. A. E. Barlow,13 for example, repeatedly 

speaks of the "nickel-bearing eruptive." Browhe compares the 

occurrences at Sudbury with the phenomena observed in cooling a

1 See L. Bourgeois, Reproduction artiflcielle des mine'raux, p. 35, for old instances. Also A. Brand, 

Zeitschr. Kryst. Min., vol. 12,1887, p. 234, on breithauptite.

2 Annales chim. phys., 3d ser., vol. 32,1851, p. 129.

s Liebig's Anualen, vol. 129,1864, p. 350.

« Zeitschr. Kryst. Min., vol. 17,1890, p. 497.

& Compt. Rend., vol. 65,1867, p. 75. Jaipurite is also known as syepoorite.

n Bull. Soc. min., vol. 3,1880, p. 170.

' Zeitschr. prakt. Geologie, 1893, pp. 125, 357.

s Bull. Geol. Soc. America, vol. 2,1890, p. 125. Another paper by Bell, on Sudbury, appears In Ann. 

Rept. Geol. Survey, Canada, 2d ser., vol. 5, F. 1890-91.

" Jahrb. K.-k. geol. Reichsanstalt, vol. 42,1892, p. 223. The nickel ores of Schweiderich, 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. In Rept. Ontario Bur. Mines, 1904, pt. 1, p. 192, Coleman 

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. 15, 

1907, p. 759.

" School of Mines Quart., vol. 16,1895, p. 297; and Econ. Geol., vol. 1, p. 487,1906.

' Econ. Geology, vol. 1,1906, pp. 454, 545. 
662 THE DATA OF GEOCHEMISTRY.

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,1 C. W. Dickson,2 and W. Campbell and C. W. Knight,3 

on the other hand, have argued strongly in favor of a secondary 

origin of these ores a deposition from circulating solutions.4 A 

similar view is expressed by F. W. Voit 5 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 6 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 7 thinks is an altered gabbro or norite. This 

deposit Kemp regards as originally magmatic. In the serpentines 

of Malaga, Spain, according to F. Gillman,8 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 9 as not magmatic.

Near Lake Temiskaming, Ontario, an extraordinary group of 

deposits of associated cobalt, nickel, arsenic, and silver ores has 

recently (1903) been discovered. 10 In this district native silver and 

native bismuth are found, together with niccolite, chloanthite, smaltite, millerite, 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

1 The nature of ore deposits, Weed's translation, p. 41.

2 Trans. Am. Inst. MIn. Eng., vol. 34, p. 3,1904. See also Jour. Canadian Min. Inst., vol. 9,1906, p. 236.

s Eng. and Min. Jour., vol. 82,1906, p. 909. These authors base their opinions on the microscopic structure of the pyrrhotite.

« Other memoirs upon Sudbury and its ores are by J. H. Collins, Quart. Jour. Geol. Soc., vol. 44,1888, 

p. 834; J. Gamier, Me"m. Soc. ingto. 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; and L. P. Silver, Canadian Min. Rev., vol. 21,1902, p. 207.

5 Jahrb. K.-k. geol. Relchsanstalt, vol. 50,1900, p. 717.

<>Missouri Geol. Survey, vol. 9, pt. 4,1896, p. 82.

i Trans. Am. Inst. Min. Eng., vol. 24,1894, p. 620.

«Trans. Inst. Min. and Met. (London), vol. 4,1896, p. 159. 

. »Zeitschr. prakt. Geologic, 1907, p. 73.

1° 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 OKES. 663

are classical localities for cobalt and nickel minerals. The original 

source of the Temiskaming qres 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 .7H20; bieberite, CoS04 .7H20; the 

arsenates, roselite, erythrite, annabergite, forbesite, and cabrerite; 

the carbonates sphserocobaltite, zaratite, and remingtonite; the oxide 

bunsenite; and the hydroxides asbolite, heubachite, heterogenite, 

transvaalite, etc., are among these products of alteration. Bunsenite, 

MO, 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 bear 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 

are found in North Carolina; 8 at Kevda in the Urals; at Frankenstein, Prussian Silesia, in serpentine; and at Mount Avala, Servia, 

with mercurial minerals. The most important deposits, however, are

i These ores have recently been studied microscopically by W. Campbell and C. W. Knight (Econ. 

Geology, vol. 1, 190C, p. 767), who find that smaltite was first formed, then niccolite, then calcite, with 

argentite, native silver, and native bismuth later.

3 Compt. Eend., vol. 33,1851, p. 525.

3 See L. Bourgeois, Reproduction artificielle des minfiraux, 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 recent report on 

the Riddles ores, by G. F. Kay, appears in Bull. U. S. Geol. Survey No. 315,1907, p. 120.

8 See H. J. Biddle, Mineral Resources U. S. for 1886, U. S. Geol. Survey, 1887, p. 170. The mother rock 

here Js 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.
664 THE DATA OF GEOCHEMISTRY.

in New Caledonia, 1 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 

H4Mg2Ni2 (Si04) 3 .4H20, and connarite is near H4Ni2Si3010 . Another silicate from New Caledonia, called nepouite, 2 has been given 

the formula (NiMg) 3Si2O7 .2H2O. 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, p. 21,1890.

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 r»

Fe2 03 - ............................ ...

NiO............. ....................'..

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

HoO 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

} 7.00 '

100. 24

C

48.25

| .55

14.60

16.40

10.95

8.82

99.57

D

38.35

.40

.15

32.52

10.61

6.44

11.53

100. 00

E

50.15

.57

trace

10.20

17.43

11.28

10.37

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 casfc 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 

cent of Cr203 . The native metal has not been found, nor are any terrestrial sulphides of chromium known, although the mineral daubre"elite, FeCr2S4 , occurs in some meteoric irons. The one important ore

i See A. Liversidge, Minerals of New South Wales, p. 275; J. Gamier, Compt. Rend., vol. 86,1878, p. 

684; D. Levat, M6m. Assoc. franc, 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.

2E. Glasser, Compt. Rend., vol. 143, 1906, p. 1173. Also Annales des mines, 10th ser., vol. 4, 1904, 

p. 448.
METALLIC OEES. 665

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 FeCr2 04 , 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 H. W. Foote. Variety named mitchellite. For A, B, 

and D, see J. H. Pratt and J. V. Lewis, North Carolina Geol. Survey, vol. 1, p. 369,1905. Magnochromite 

is another name for a magnesian chromite.

E. From Tampadel, lower Silesia. Analysis by Laszczynski. Described by H. Traube, Zeitschr. 

Deutsch. geol. Gesell., vol. 46, p. 50,1894.

Cr203 ---------------------------------

A1208 ..................................

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

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

CoO.NiO..............................

CuO...................................

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

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

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

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

P O

A

59.50

7.15

25.02

.92

4.42

3.20

99.91

* B

57.20

7.82

25.68

.69

5.22

2.80

,)9. 41

C

45.94

2.51

42.90

.84

.16

.40

2.81

1.40

3.20

.36

.12

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 

of the product was made to vary, like that of the natural mineral.

» See S. M. Losanitsch, Ber. Deutsch. chem. Gesell., vol. 28,1895, p. 2631.

aSee also table in Chapter X, on rock-forming minerals, p. 326. Two of the analyses there given are 

repeated here. > s Annales chim. phys., 3d ser., vol. 22,1848, p. 228.
666 THE DATA OF GEOCHEMISTRY.

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 surface 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, 

MoS^. The molybdate of lead, wulfenite, has already been described 

in a previous section. Calcium molybdate, powellite, is a rare mineral, and natural molybdates of cobalt and magnesium are imperfectly known, Molybdic ocher is a common oxidation product of 

molybdenite. It is, as shown by W. T. Schaller,4 a hydrous ferric 

molybdate, Fe2 (Mo04 ) 3 .7|H2O.

Artificial molybdenite has been prepared by A. de Schulten.5

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,6 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.

1 Annales chim. phys., 4th ser., vol. 16,1869, p. 90.

2 Compt. Rend., vol. 110,1890, p. 424.

3 See J. H. L. Vogt, Zeitschr. prakt. Geologie, 1894, with special reference to Norwegian deposits. On 

chromite at Kraubath, Styria, see F. Ryba, 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. 3,1896, 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., p. 281, vol. 7; 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.

« Am. Jour. Sci., 4th ser., vol. 23,1907, p. 297. Work done in the laboratory of the United States Geological Survey.

* Geol. Foren. FSrhandl., vol. 11,1889, p. 401.

« Bull. Soc. min., vol. 17,1894, p. 612.
METALLIC ORES. 667

As a rule, molybdenite is a fairly pure compound, although 

Michel 1 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,2 large 

quantities of molybdenite are found in a quartz vein in granite. At 

Cooper, Maine, as described by G. 0. Smith,3 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,4 

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.

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, htibnerite; calcium tungstate, scheelite; the copper salt, cuprotungstite; and 

an alteration product, tungstic ocher. Of these, wolframite, hubnerite, and scheelite are economically important, and all three have 

been prepared artificially.

N. S. Manross 5 obtained scheelite by fusing sodium tungstate with 

calcium chloride. A. Cossa 0 also prepared it by fusing the amorphous compound, CaW04 , with common salt. H. Debray 7 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 acid 

crystallized at the same time. A. Geuther and E. Forsberg 8 produced wolframite and its manganesian varieties by fusing sodium 

tungstate with ferrous chloride, or with the mixed chlorides of iron 

and manganese. L. Michel,9 by fusing sodium tungstate and sodium 

chloride with the chlorides of calcium, manganese, iron, or lead, 

obtained scheelite, hubnerite, wolframite, and stolzite, respectively.

1 Bull. Soc. mln., vol. 22,1899, p. 29.

2 Bull. Geol. Soc. America, vol. 15,1904, p. 283.

3 Bull. U. S. Geol. Survey No. 260,1905, p. 197.

« Canadian Min. Rev., vol. 22,1903, p. 113.

6 Liebig's Annalen, vol. 81,1852, p. 243.

6 Cited by L. Bourgeois, Reproduction artificielle des mineraux, p. 172.

' Compt. Rend., vol. 55,1862, p. 287.

8 Liebig's Annalen, vol. 120,1861, p. 270.

8 Bull. Soc. min., vol. 2,1879, p. 142.
THE DATA OF GEOCHEMISTRY.

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,1 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.2 The Tungsten deposits of the Dragoon Mountains, 

Arizona, are of the same character,3 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 4 and W. H. Hobbs.5 In the 

Sierra de Cordoba, Argentina, according to G. Bodenbender,6 the 

wolframite is again in quartz veins in granite, and molybdenite is 

sometimes present also. These illustrations of tungsten occurrences 

are ample for present purposes.

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 d.egree 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 platinum.

Native iridium, and platiniridium. 

Native palladium, isometric. 

Allopalladium, rhombohedral. 

Iridosmine.1 Nevyanskite over 40 per cent Ir. 

I Siserskite, 30 per cent Ir, or less. 

Palladium gold.7 

Rhodium gold. 7

1 Trans. Am. Inst. Min. Eng., vol. 31,1901,V 683. See also J. D. Irving and S. F. Emmons, Prof. Paper 

U. S. Geol. Survey No. 26,1904, p. 163.

2 See F. B. Weeks, Twenty-first Ann. Kept. U. S. Gdol. Survey, pt. 6,1901, p. 319; and F. D. Smith, 

Eng. and Min. Jour., vol. 73,1902, p. 304.

8 See W. P. Blake, Trans. Am. Inst. Min. Eng., vol. 28, 1898, p. 543, and F. Pvickard, Eng. and Min. 

Jour., vol. 78,1904, p. 263.

4 Trans. Am. Inst. Min. Eng., vol. 22,1893, p. 236.

5 Twenty-second Ann. Kept. U. S. Geol. Survey, pt. 2,1902, p. 13.

«Zeitschr. prakt. Geologic, 1894, p. 409. On the tungsten ores of Colorado, see W. Lindgren, Econ. 

Geology, vol. 2,1907, p. 453, and B. D. George, First Rept. Colorado Geol. Survey, 1908, p. 7. On tungsten 

deposits in the Coeur d'Alene region, Idaho, see H. S. Auerbach, Eng. and Min. Jour., vol. 86,1908, p. 1146.

? See section on gold, ante, p. 615.
METALLIC ORES. 669

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: 1

Analyses of native platinum.

A. From Choco, 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. 21,1881, 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. Hofimann, 

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. Geologie, 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............... ......

O«

Pd..... ..............

Rh...................

Au....................

Cu............. .......

Fe...................

Iridosmine............

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

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

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

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

.21

3.30

1.59

18.93

3.75

98.07

F

68.19

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

1.27

99.97

H

72.96

.88

21.82

undet.

trace

.42

96.08

In another sample of Uralian platinum, A. Terreil 2 found 0.75 

per cent of nickel. A remarkable nugget from the river Approuague, French Guiana, gave A. Damour 3 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 See J. F. Kemp, Bull. U. S. Geol. Survey No. 193,1902, for a full collection of analyses, both of platinum 

and iridosmine. Other analyses by W. J. Martin, jr., appear in Sixteenth Ann. Kept. U. S. Geol. Survey, 

pt. 3,1895, p. 633. See also Dana's System of mineralogy, 6th ed., pp. 26, 27. Recent analyses of Uralian 

platinum by L. Duparc and H. C. Holtz are in Min. pet. mitt., vol. 29,1910, p. 498. 

2 Compt. Rend., vol. 82,1876, p. 1116.

| 3 Idem, vol. 52,1861, p. 688.
670 THE DATA OF GEOCHEMISTRY.

Analyses of native iridium, etc.

A. Native iridium. Nizhni Tagilsk, Urals.

B. Platiniridium, probably from Brazil. Analyses A and B by Svanberg, Berzelius's Jahresber., 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

1.78

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

100. 00

D

77.20

1.10

21.00

.50

.20

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, Nevada. On the other hand L. Duparc,5 who has 

devoted much study to Uralian platinum, reports its association 

with pyroxenite and gabbro.

A. Daubre"e, 8 many years ago, commenting upon the constant 

association of platinum with olivine rocks and chromite, pointed out

1 See English translation from the Russian in U. S. Geol. Survey Bull. 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.

3 See D. T. Day, Nineteenth Ann. Kept. 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.

5 Arch. 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. 

Saytzeff Zeltschr. prakt. Geologic, 1898, p. 395; C. W. Purington, Trans. Am. Inst. Min. Eng., vol. 29,1899, 

p. 3; and R. Spring, Zeitschr. prakt. Geologic, 1905, p. 49.

<>Compt. Rend., vol. 80,1875, p. 707.
METALLIC ORES. 671

the similarity of these rocks to meteorites. Much later, J. M. Davison 1 announced the presence of platinum and iridium in the meteoric 

iron of Coahuila. Still more* recently, S. Meunier 2 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 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 3 mentions its occurrence in certain 

Pennsylvanian shales, and states also that the palladium gold of 

Brazil is sometimes associated with itabirite. E. Hussak 4 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,5 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. 8 F. Sandberger 7 identified platinum in limonite nodules from 

Mexico. In an altered limestone lens in Sumatra, L. Hundeshagen 8 

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, recently described by J. B. Bell,9 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 10 found it in chalcocite, in a gangue of dolomite, 

quartz, and barite, at Chapeau Mountain, in the French Alps. The 

country rock was a metamorphic limestone. H. Rossler 11 detected

i Am. Jour. Sci., 4th ser., vol. 7,1899^ p. 4.

5 Compt. rend. VII. Cong. geol. internat., 1897, p. 157.

a 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. Kept 

Dept. Mines, New South Wales, 1889, p. 249.

«See Seventeenth Ann. Kept. U. S. Geol. Survey, pt. 3,1896, p. 282.

' Neues Jahrb., 1875, p. 625.

sTrans. Inst. Min. Met., vol. 13,1903-4, p. 550.

"Econ. Geology, vol. 1,1906, p. 749. 

i°Compt. Rend., vol. 29,1849, p. 814. 

it Liebig's Annalen, vol. 180,1875, p. 240.
672 THE DATA OF GEOCHEMISTRY.

both platinum and palladium in silver bullion; and H. Vogel 1 

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,2 associated with nickeliferous pyrrhotite and chalcopyrite, 

but most intimately with the latter. F. W. Clarke and C. Catlett,3 

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. 4 Here, also, sperrylite has 

been identified.5 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 6 

in the pegmatite of Copper Mountain, British Columbia. One small 

crystal was embedded in biotite. Platinum is also present, according 

to C. W. Dickson,7 in chalcopyrite from the Key West mine, Bunkerville, Nevada; but sperrylite could not be detected. J. H. L. Vogt 8 

found platinum to be present in the nickeliferous pyrrhotites of Norway, and R. W. Brock 9 -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. 10 The presence of platinum in sulphide ores near Broken Hill 

has been reported by J. C. H. Mingaye. 11

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 tungsten, 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.

1 Oesterr. Zeitschr. Berg- u. Hiittenw., vol. 39, p. 32.

2 See H. L. Wells, Am. Jour. Sci.,3dser.,vol. 37,1889, p. 67. Sperrylite has since been found by W. E. 

Hidden (idem, 4th ser., vol. 6,1898, 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, see 

the section on nickel and cobalt, ante, p. 661.

sBull. U. S. Geol. Survey No. 64,1890, p. 20.

<See W. C. Knight, Eng. and Min. Jour., vol. 72, 1901, p. 845; vol. 73,1902, p. 696; J. F. Kemp, Cont. 

Geol. Dept. Columbia Univ., vol. 11, No. 93,1903; S. F. Emmons, Bull. U. S. Geol. Survey No. 213,1903, 

p. 94; and T. T. Read, Eng. and Min. Jour., vol. 79,1905, p. 985.

5 H. L. Wells and S. L. Penfleld, Am. Jour Sci., 4th ser., vol. 13,1902, p. 95.

e Eng. and Min. Jour., vol. 79,1905, p. 127.

"Jour. Canadian Min. Inst., vol. 8,1905, p. 192. Memoir on the distribution of the platinum metals 

in other sources than placers.

8 Zeitschr. prakt. Geologie, 1902, p. 258.

»Eng. and Min. Jour., vol. 77,1904, p. 280.

10 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.

"Rec. Geol. Survey New South Wales, vol. 8,1909, p. 287.
METALLIC OEES. 673

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 

ever higher, in one biotite, for example, reaching 0.127 per cent of 

V203 . 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 0 similar 

results. lie 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 9 found it in the 

ashes of peat from North Carolina. A. Jorissen 10 discovered it in 

delvauxite, which is a hydrous phosphate of iron.

A still more remarkable occurrence of vanadium was noted by J. J. 

Kyle 11 in a lignite from San Rafael, 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 12 obtained 38.5 per cent of V2O5 

from the ash; and in another, from Yauli, Peru, Torrico y Meca 13

1 See A. A. Hayes, Proc. Am. Acad., vol. 10,1875, p. 294. Hayes found vanadium in many rocks, and 

also in the waters of Brookline, Massachusetts. For determinations of vanadium in lavas of Vesuvius and 

Etna, see L. Ricciardi, Oazz. chim. ital., vol. 13,1883, p. 259. Scattered determinations are numerous.

2 Bull. U. S. Geol. Survey No. 167,1900, p. 49. See also J. H. L. Vogt, Zeitschr. prakt. Geologic, 1S99, 

p. 274, on the distribution of vanadium in rocks. W. Pollard (Summ. Prog. Geol. Survey Great Britain, 

1902, p. GO) 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. C8,1910, p. 91.

8 Annales chim. phys.,-3d ser., vol. 61, 186], pp. 309, 342. See also L. Dieulafait, Compt. Rend., vol. 

03, 1881, p. 804.

« Compt. Rend., vol. 49, 1859, p. 301.

& Proc. Roy. Soc. New South Wales, vol. 17, 1883, p. 133. He cites similar examples from other 

authorities.

8 Rec. Geol. Survey New South Wales, vol. 7, 1903, p. 219.

i Atti Accad. Lincei, 3d ser., vol. 3, 1879, p. 403.

a See also E. Demarcay, Compt. Rend., vol. 130,1900, p. 91.

»Jour. Am. Chem. Soc., vol. 21, 1S99, p. 70R.

;o Annales Soc. gdol. Belgique, vol. 6, 1878-9, p. 41.

11 Chem. News, vol. 66, 1892, p. 211. 

'" Compt. Rend., vol. 117, 1893, p. 546.

13 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.

101381° Bull. 491 11 43
674 THE DATA OF GEOCHEMISTRY.

discovered 38 per cent. The ash of a grahamite from near Page, 

Oklahoma, analyzed in the laboratory of the United States Geological Survey by K. C. Wells, contained 12.2 per cent of V205 . 

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 vanadate 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.1 A Mexican variety 

of descloizite, ramirite, 2 has also been commercially exploited. These 

vanadates, with the exception of mottramite, occur principally in 

metalliferous veins; and A. Ditte 3 attributes their formation to percolating vanadiferous waters acting on other compounds, most commonly the compounds of lead.

A sulphovanadate of copper, sulvanite, Cu 3VS4 , is found in South 

Australia.4 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.5 This occurrence may well be correlated with the other 

discoveries of vanadium in the ash of coal; and the sulphates, equivalent to 13.70 per cent of S03 , found by Kyle in his analysis, may show 

that he too had originally a sulphide to deal with which was oxidized 

during combustion.

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.6 It contains about 24 

per cent of V2O3 . In a green sandstone from Placerville, Colorado, 

W. F. Hillebrand 7 found 3.50 per cent of V2 03, which was present in 

a replacement of the original calcareous cement. The green mineral, 

isolated, contained 12.84 per cent of V2 03 and was apparently a 

variety of roscoelite, or else a closely related compound.

1 See H. E. Roscoe, Proc. Roy. Soe., vol. 25,1876, p. 111.

2 See G. de J. Caballero, Mem. Soc. cient. Ant. Alzate, vol. 20, 1903, p. 87.

s Compt. Rend., vol. 138,1904, p. 1303.

< See G. A. Goyder, .Tour. Chem. Soc., vol. 77,1900, p. 1094.

5 See D. F. Hewett, Eng. and Min. Jour., vol. 82, 1906, p. 3S5; and .1. J. Bravo, Inform, y Mem. Pol. 

Soc. ingen. minas, Lima, vol. 8, 1908, p. 171. For a later and much more complete description of the 

sulphide, patronite, and its associated minerals, see W. F. Hillebrand, Am. Jour. Sci., 4th ser., vol. 24. 

1907, p. 141. The bituminous matrix he names quisqueite. A still later memoir on vanadium deposits 

in Peru, by Hewett, is in Bull. Am. Inst. Min. Eng., 1909, p. 291.

« Bull. U. S. Geol. Survey No. 167, 1900, p. 73.

' Bull. U. S. Geol. Survey No. 262,1905, p. 18.
METALLIC ORES. 675

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 in metaUiferous veins, as at Joachimsthal, 1 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, 2 will serve to illustrate the 

variations:

Analyses of uraninite.

A. Hale's quarry; Glastonbury, Connecticut. 

B. Near Central City or Blackhawk, Colorado. 

C. Johanngeorgenstadt, Saxony.

D. Nivenite, Llano County, Texas. 

E. Broggerite, Annerod, Norway. 

F. Cleveite, Arendal, Norway.

U03 . ........................

uo2 .........................

ThOa ........................

Ce02 ........................

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

(La, Di)203 ... ................

Y,Er)aO... ..................

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

Fe2 03 .......................

FeO........... ...............

PbO..........................

ZnO. .......................

CuO.........................

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

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

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

Bi203 .......................

V205 , Mo03 ,W03 . .............

so..........................

PO

He

H20.........................

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

CuPeSj......................

FeSa .. .......................

A

26.48

57.43

9.79

.25

.13

.20

.40

3.26

.08

trace

undet.

.61

.16

.70

99.49

B

25.26

58.51

.22

7.59

.32

.70

.44

.16

.84

.22

.43

.02

1.96

2.79

.12

.24

99.82

C

22.33

59.30

none

none

none

20

.21

6.39

.17

.09

1.00

.17

.75

.75

.31

.19

.06

2.34

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

. 66

9.76

.03

10 R4

1.06

.10

.23

1.23

.90

1.10

94.50

1 On the Joachimsthal ores, see Janda, Oesterr. Zeitschr. Berg- u. Hiittenw., vol. 50, p. 283; also J. 

St6p and F. Becke, Zeitschr. prakt. Geologie, 1905, p. 148. R. Pearce (Proc. Colorado Sci. Soc., vol. 5, 

1895, p. 156) has described the occurrence of uraninite in a mine near Central City, Colorado. On uranium 

ores .in German East Africa, see W. Marckwald, Ceritralbl. Min., Geol. u. Pal., 1906, p. 761.

* See Bull. U. S. Geol. Survey 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.
676 THE DATA OF GEOCHEMISTRY.

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 uranium1 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, 

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 source of radium to-day is in the 

uraninite of Joachimsthal, and that uranium itself may be 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.2 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. 4 An outlying region for carnotite in 

Rio Blanco County, Colorado, has recently been described by H. S. 

Gale. 5

The following analyses of carnotite, by Hillebrand, will show its 

general character:

1 For analyses of gummite, see H. von Foullon, Neues Jahrb., 1885, pt. 1, Ref., p. 21, and F. A. Genth, 

Am. Chem. Jour., vol. 1,1879, p. 89.

2 Compt. Rend., vol. 128,1899, p. 532. 

s Bull. U. S. Geol. Survey No. 262,1905, p. 9. 

< Bull. U. S. Geol. Survey No. 260,1904, p. 200.

6 Bull. U. S. Geol. Survey No. 315,1907, p. 110. 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.
METALLIC ORES. 67'

 Analyses of carnotite.

A. Copper Prince claim, Eoc Creek, Montrose County, Colorado. 

B. Yellow Boy claim, La Sal Creek, Montrose County.

uos .. ..........................................................

v,ofi .... ......................................................

P O

A« n

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

FeaOa ... .......................................................

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

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

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

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

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

Na20. .........................................................

Li20 ............................-....-.- - -- 

HaO- ........................................................

HaO+........................................................ Pbo.................................................. ........

CuO. ..........................................................

Mo03 .........................................................

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

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

C02 . ..........................................................

A

54.89

18.49

.80

.09

.21

3.34

.02

.90

.22

6.52

.14

trace

2.43

0 11

.13

.15

.18

.15

.03

.56

7.10

98.46

B

54.00

18. 05

.05

.29

.42

1.86

2.83

.14

5.46

.13

trace

3.16

2.21

.07

trace

.05

.20

(?)

none

10.33

99.25

With the carnotite a vanadif erous silicate also occurs, which may be 

akin to roscoelite.1 The origin of these Colorado ores is not known.

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. The genesis of these strange ores is yet to be discovered. Carnotite has also been reported by D. Mawson 2 in the pegmatite of "Radium Hill," South Australia.

Uranium, like vanadium, has been found in coal. In an anthracitic bitumen from Sweden, described by A. E. Nordenskiold,3 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.

i According to A. II. Phillips (Proc. Am. Philos. Soc., vol. 43,1904, p. 157), the Utah carnotite contains 

radium.

a Trans. Roy. Soc. South Australia, vol. 30,1906, p. 188. 

3 Compt. Rend., vol. 116,1893, p. 677.
678 THE DATA OF GEOCHEMISTRY.

Liebert, working in C. Winkler's laboratory, found from 1.68 to 2.87 

per cent of UgOg. 1 An anthracitic mineral from a pegmatite vein in 

the Saguenay district, Canada, yielded J. Obalski 2 2.56 per cent of 

uranium, equivalent to 35.43 per cent in the ash. The significance 

of these occurrences remains to be determined.

COLTJMBIUM, 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.

Columbium3 and tantalum are acid-forming elements, whose 

typical oxides have the formulae Cb205 and Ta205 . They enter into 

the composition of a considerable number of minerals, which are 

found principally in pegmatites. Among these, columbite, tantalite, 

samarskite, and euxenite are by far the most important. Columbite 

and tantalite are salts of iron, FeCb2O6 and FeTa2 06, which commonly occur more or less isomorphously commingled, often with 

manganese partly replacing the iron. Metallic tantalum4 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. 5 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, ZrO2 . 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 speci1 See C. Winkler, Zeitschr. Kryst. Min., vol. 37,1903, p. 287.

2 Jour. Canadian Min. Inst., vol. 7,1904, p. 245.

8 Known in Germany as niobium. The name columbium has about 40 years' priority and refers to the 

original discovery of the ore in America. Niobium is etymologically meaningless.

< Native tantalum has been reported from two localities in Siberia by P. Walther, Nature, 1909, p. 335, 

and W. von John, idem, 1910, p. 398.

6 See Werner von Bolton, Zeitschr. angew. Chemie, 1906, p. 1537.
METALLIC OEES. 679

mens 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. Thorianite, 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. 1

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.

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.2 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 CePO4 , is, 

however, the chief source of the cerium earths at the present day. 

It is obtained for commercial purposes from detrital deposits of 

monazite sand, 3 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: 4

1 According to C. Bask'erville (Jour. Am. Chem. Soc.,vol. 26,1904, p. 922), the thorium previously described 

is a mixture of three elements, thorium, berzelium, and carolinium. His results, however, have been 

doubted, and the question is not yet finally settled. For an elaborate paper on theoccurrence of thorium 

in the mineral kingdom, see J. Schilling, Zeitschr. angew. Chemie, 1902, p. 869.

3 See J. W. Mallet, Am. Jour. Sci., 3d ser., vol. 14,1877, p. 397.

3 On the monazite sand of North Carolina, see H". B. C. Nitze, Bull. North Carolina Geol. Survey No. 9, 

1898. Also the references on p. 338, ante. Nitze cites 37 analyses of monazite. On monazite sand in the tinbearing alluvium of the Malay Peninsula, see Bull. Imp. Inst., vol. 4,1906, p. 301.

«Am. Jour. Sci., 3d ser., vol. 24, 1882, p. 250. The symbol Di represents the old didymium, which is 

now known to be a mixture of neodymium, praseodymium, samarium, etc.
680 THE DATA OF GEOCHEMISTRY.

Analyses ofmonazite.

A. From Portland, Connecticut. B. From the sands of Brindletown, North Carolina. C. From Amelia 

Court House, Virginia.

P o

CeA-- ................................................

(La, Di)8 03 ----- -------- ................................

Th02 ...................................................

SiQf............. .......................................

Ignition ...............................................

A

28.18

38.54

28.33

8.25

1.67

.37

100. 34

B

29.28

31.38

30.88

6.49

1.40

.20

99.63

c

26.12

29.89

26.66

14.23

2.85

.67

100. 42

Yttria and its companions, erbia, terbia, ytterbia, etc., are obtained 

for the most part from gadolinite, Gl2FeY2Si2010 . 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 Barringer Hill, Llano 

County, Texas. Here, in a giant pegmatite, containing enormous 

crystals of quartz and feldspar, gadolinite is found in large crystals, 

together with yttrialite, thorogummite, nivenite, fergusonite, allanite, 

tengerite, cyrtolite, rowlandite, mackintoshite, and yttrocrasite. 

Several of these species and varieties are peculiar to this locality. 1 

According to Hidden, most of these minerals are radioactive, and 

both he and his assistant, working in the deposit, were annoyed by an 

irritation of the skin like that produced by the radium emanations or 

the X rays.

1 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 substances, 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 

with the following scheme:

! CnH2ll+2 . 6. CnH2n_8 .

2. CnH2n . 7. CnH2n_10 .

3. CnH2ll_2 . 8. CnH2n_12 .

4. CnH2n_4 . . .

5. CnH2n_e . . 18. CnH2n_;

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 mem681
682 THE DATA OF GEOCHEMISTRY.

bers of the series are liquids, Avitli 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

Paraffins from Pennsylvania petroleum.

Name. 

1. Gaseous: 

Methane. ............................

Ethane. .............................

Propane. .............................

Butane. .............................

2. Liquid: 

Pentane. ..........:..................

Hexane. .............................

Heptane. ............................

Octane.................. ....... . ..

Decane. ..............................

Endecane. ...........................

Dodecane ...........................

3. Solid: 

Octodecane. .........................

Eicosane. ............................

Nonocosane. ..........................

Dotriacontane .......................

Tetratriacontane. . ...................

Pentatriacontane a. ...................

Formula.

CH4 .......

n TT

r\ TT 05H12 ......

06H14 ......

UH16 ......

C9H ..... r\ TT 010H22 .....

CnH24 .....

Wtt26 .....

n C14HTT 30 .....

C15H22 .....

r\ TT UgHjg.....

r TT

P TT

n TT

r* ^31^64 TT - -

fl TT

r TT

Melting point.

°C. 

-186

-172. 1

- 51

- 31

- 26

- 12

+ 4

18

37

48

50-51

53-54

55-56

60

62-63

66

67-68

71-79

76

Boiling point.

"C. 

-164

- 84.1

- 37

+ 1

37

69

98

125

150

173

195

214

252

o 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, 

isohexane, isoheptane, and isooctane must be added, and even then 

the list is probably not complete. For instance, the solid paraffins 

C27H5e 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, 2 the total paraffins varied between 

94.13 and 95.73 per cent. Methane ran from 79.95 to 86.48 per cent

« The table is condensed from H. Hofer's valuable work, Das Erdol, 2d ed., Braunschweig, 1906, pp. 58-59. 

2 West Virginia Geol. Survey, vol. 1 A, 1904, p. 556.
THE NATURAL HYDROCARBONS. 683

and ethane from 7.65 to 15.09. The following analyses from other 

sources may be cited more in detail: 1

Analyses oj natural gas.

A. From Creighton, Pennsylvania.

B. From Pittsburg, Pennsylvania.

C. From Baden, Pennsylvania.

D. From Vancouver, British. Columbia. Analyses A to D by F. C. Phillips, Am. Chem. Jour., vol. 16, 

1894, p. 406. 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 McGee, Eleventh Ann. Rept. U. S. Geol. Survey, pt. 1,1891, p. 592.

F. From Osawatamie, Kansas. From a table of seven analyses by E. H. S. Bailey, Kansas Univ. 

Quart., vol. 4,1895, p. 1.

CH

Paraffins'1 ....................

C2H4 , etc...... ...............

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

jj 2

N2

g2 g

Q 2

2

A

96.36

3.64

none

none

100. 00

B

98.90

.40

none

.70

none

100. 00

c

87.27

.41

none

12.32

100. 00

D

93.56

.14

none

6.30

100. 00

E

93.36

.28

.53

.25

1.76

3.28

.18

.29

99.93

F

97.63

.22

1.32

.22

none

.60

100. 00

<* Largely CH<, with more or less ethane. CO not found by Phillips.

The analyses of Pennsylvania gases by S. P. Sad tier 2 gave somewhat different results. In gas from four different wells he found, 

in percentages, CH4 , 60.27 to 89.65; C2H6 , 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 3 

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 in 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. 4

1 See also Mabery, Am. Chem. Jour., vol. 18,1896, p. 215, for analyses of gas, largely methane, from southern Ohio. Hofer (Das Erdol, pp. 100-103) gives many other data. In Boverton Redwood'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. 260,1905, 

p. 481. Many other analyses are published in Trans. Am. Inst. Min. Eng., vol. 15, pp. 529 et seq. Many 

analyses of Kansas gases are given by H. P. Cady and D. F. McFarland, Kansas Univ. Geol. Survey, 

vol. 9,1908, p. 228. They found in nearly all samples appreciable quantities of helium, and also argon and 

neon. See also Trans. Kansas Acad. Sci., vol. 20,1907, p. 80; vol. 21,1908, p. 64.

2 Second Geol. Survey Pennsylvania, Rept. 1,1876, pp. 146-160. Sadtler cites some analyses by other 

chemists.

3 Jour. Am. Chem. Soc., vol. 20,1898, p. C96. 

« See H. Hofer, Das Erdol, p. 65.
684 THE DATA OF GEOCHEMISTRY. 

So-called "olefmes" isolated from petroleum.

Name.

1. Gaseous: 

Ethylene. ............................

Propylene. ..........................

Butylene. ............................

2. Liquid:

Hexylene ...........................

TViH Pfvlpnp

3. Solid:

Formula.

C

TT 

2J±4 .......

C

TT 

4J18 . ......

rO1 TT 5i±10 --.-.-

C\ TT 06M 12 ......

C7H14 ......

P 09HTT 18 ......

010M20 .....

r\ TT

C

TT" 

, 6H32 . . ...

P TT

r\ TT JH*«-----

Melting point.

65-66

62

Boiling point.

-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 defines. 

According to C. F. Mabery, 1 however, the true defines, 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 CnH2n are not olefines, but 

cyclic hydrocarbons of the polymethylene series, which were originally called naphtenes. 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 

seem not to have been found in petroleum; but several of its higher

1 Jour. Am. Chem. Soc., vol. 28,1900, p. 415. An important summary of our knowledge relative to the 

composition of American petroleums.

2 Proc. Am. Acad., vol. 41,1905, p. 89.

s Idem, vol. 36,1901, p. 255.

* Idem, p. 295.

6 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. 685

members are characteristic of oils from Texas, Louisiana, and Ohio. 

In oil from the Trenton limestone of Ohio, Mabery and 0. H. Palm 1 

found hydrocarbons having the composition C19H30 , C21H40 , C?2H42 , 

and C24H4e . With these compounds were members of the Cnli2n 

series as high as C17H34 . There were also members of the next series, 

CnH2D_ 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 , C10H30 , C17H30, C18H32 , C24H44 , C27H46 , 

and C29H50 .

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.....................................................C8Ha

Toluene......................................................C7H8

Xylene.....................................................C8H10

Cumene.....................................................C9H12

Cymene..................................................... C10Hj4

Etc.

According to Mabery,0 Pennsylvania petroleum contains small proportions of the lower members of this series, and Mabery and Hudson 7 

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.8 Naphthalene, C10H8 , is the only 

compound of the series CnH2n_ 12 which has been certainly identified 

in petroleum. It was found by C. M. Warren and F. H. Storer 0 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

1 Am. Chem. 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. No. 

5, Univ. Texas, 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. 303; and N. M. Fenneman, Bull. U. S. Geol.Survey No. 282, 

1906. Fenneman describes both Texas and Louisiana petroleums. On the composition of Kansas oils 

see 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.

«See C. Richardson and E. C. Wallace, Jour. Soc. Chern. Ind., vol. 21,1902, p. 316; and Thiele, Chem. 

2eitung, vol. 26,1902, p. 890.

6 Am. Chem. Jour., vol. 33,1905, p. 270.

s Jour. Am. Chem. Soc., vol. 28,1906, p. 418.

7 Proc. Am. Acad., vol. 36,1890, p. 255.

8 R. Zaloxiecki and J. Hausmann (Zeitschr. angcw. Chemie, 1907, p. 1701) have called attention to the 

richness of Roumanian petroleum in aromatic hydrocarbons. 

» Mem. Am. Acad., 2d ser., vol. 9,1865, p. 208.
686 THE DATA OP GEOCHEMISTRY.

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 originally present 

in the natural oil. 1

In many petroleums small quantities of oxidized bodies are contained, sometimes complex acids, sometimes phenols. According to 

Mabery,2 the phenols are found in notable proportions in some California oils, but not in petroleum from the eastern part of the United 

States.

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,3 and Mabery 4 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 5 

found normal sulphides of the paraffin series, and isolated, ten compounds ranging from methyl sulphide, C2H0S, to hexyl sulphide, 

C12H26S. In Canadian petroleum Mabery and Quayle 8 discovered 

another series of sulphur compounds, of the general formula CnH2nS, 

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. 7

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. 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 vis1 For data and references, see Hofer, Das Erdol, p. 74.

3 Jour. Am. Chem. Soc., vol. 28,1906, p. 596.

s Am. Jour. Sci., 3d ser., vol. 48,1894, p. 250.

«Jour. Soc. Chem. Ind., vol. 19,1900, p. 505. F. X. Bandrowsky (Monatsh. Chemie, vol. 8, 1887, p. 224) 

and A. Weller (Ber. Deutsch. chem. Gesell., vol. 20,1887, p. 2097) have detected nitrogenous bases In European oils.

s Am. Chem. Jour., vol. 13,1891, p. 233.

s Proc. Am. Acad., vol. 41,1905, p. 89. A paper by R. Kayser, published in 1897, contains 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.

i On sulphur in California petroleum, see S. F. Peckham> Proc. Am. Philos. Soc., vol. 36, 1897, p. 108. 

Also S. F. and H. E. Peckham, Jour. Soc. Chem. Ind., vol. 16,1897, p. 996, on the sulphur content of bitumens.
THE NATURAL HYDROCARBONS. 687

cous, 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. 1 Scheererite, fichtelite, konlito, 

hatchettite, ozokerite, zietrisikite, elaterite, hartite, napalite, etc., are 

among these 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.2 Most of these substances are found in 

small quantities, and are so imperfectly described that they need no 

detailed consideration here. Others, like ozokerite, albertite, 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 3 found a hydrocarbon to which they gave the name lekene, 

and which appears to be a polymer of CH2 . In the ozokerite of 

Utah paraffin predominates, of composition between C18H38 and

C^Hsz- 4

Uintaite, or gilsonite,5 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.0 

The exact nature of these hydrocarbons is yet to be determined. The

1 See Dana, System of mineralogy, Oth ed., pp. 990-1024.

 Bitumen is also common in the New Almaclen 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.

a Ber. Deutsch. chem. Gesell., vol. 10,1883, p. 1547.

< On Utah ozokerite, see J. S. Newberry, Am. Jour. Sci., 3d ser., vol. 17,1879, p. 340; and A. N. Seal, 

Jour. Franklin Inst., vol. 130,1890, p. 402. A monographic paper on ozokerite by E. B. Gosling (School 

of Mines Quart., vol. 10,1894, p. 41) contains a bibliography of the mineral. Der Erdwachsbergbau in 

Boryslaw, by J. Muck, Berlin, 1903, is an important monograph on ozokerite.

6 Uintaite has priority, but gilsonite is the name most commonly used. On this bitumen, sec J. M. 

Locke, Trans. Am. Inst. Min. Eng., vol. 17,1887, p. 102; R. W. Raymond, idem, vol. 18,1888, p. 113; W. 

P. Blake, idem, vol. 18,1890, p. 503; G. H. Stone, on Utah and Colorado asphalts, Am. Jour. Sci., 3d ser., 

vol. 42,1891, p. 148; and G. H. Eldridge, Seventeenth Ann. Rept. U. S. Geol. Survey, pt. 1,1890, p. 915, 

and also Bull. No. 213, 1903, p. 290. A chemical investigation of gilsonite by W. C. Day is reported iu 

Jour. Franklin Inst., vol. 140,1895, p. 221.

«Trans. Am. Inst. Min. Eng.,N vol. 18, 1890, p. 497; Eng. and Min. Jour., vol. 48, 1889, p. 542; vol. 49, 

1890, p. 106.
68.8 THE DATA OF GEOCHEMISTRY.

same remark may be applied to the albertite l of New Brunswick, ,, 

the grahamite 2 of West Virginia, the "pitch coal" 3 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, 4 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,5 by aspirating heated air through Pennsylvania petroleum for several hours, partially converted the oil 

into a substance resembling grahamite. In this experiment, obviously, 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. 6 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 borates and of

1 C. H. Hitchcock, Am. Jour. Sci., 2d ser., vol. 39,1865, p. 267; and S. F. Peclcham, idem, vol. 48,1869, 

p. 362.

2 J. P. Lesley, Proc. Am. Philos. Soc., vol. 9,1863; 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.

» W. C. Day, Nineteenth Ann. Kept. U. S. Geol. Survey, pt. 3,1898, p. 370.

1 Peckham, loc. cit., and also Am. Jour. Sci., 3d ser., vol. 48,1894, p. 389.

6 Am. Chemist, vol. 5,1875, p. 359. For analyses of Texas grahamite see E. T. Dumble, Trans. Am. Inst. 

Min. Eng., vol. 21, p. 601.

6 Jour. Soc. Chem. Ind., vol. 17,1898, p. 13; Kept. Inspector Asphalts and Cements, Washington, D. C., 

year ending June 30,1892; 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. Mech. and Min. 

Eng., vol. 47,1898, p. 119, has described the " manjak " of Barbadoes, an asphalt resembling that of Trinidad. 

See also K. W. Ells, Ottawa Naturalist, vol. 23,1907, p. 73.
THE NATURAL HYDROCARBONS. 689

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... .......................................................... 82.33

H........................................................... 10. 69

S............................................................ 6.16

N............................................................ .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. 1 Oxygen may 

act in the same way, but is eliminated, after union with hydrogen, as 

water. Richardson concludes that the bitumen consists in great part 

of unsaturated hydrocarbons, but their exact nature remains undetermined. 2 He also describes the Bermudez, Venezuela, locality.

In a recent article Richardson 3 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.

i A well-known method for preparing HiS ia to fuse paraffin with sulphur. The reaction doubtless 

involves a union of the residues from which hydrogen has been partially withdrawn that is, the formation 

of a more condensed hydrocarbon molecule. The reaction does not seem to have been exhaustively studied. 

Somo artificial "asphalts" have been prepared by heating petroleum residues with sulphur, and a similar 

substance, "byerlite," is made by the 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 Kohler's monograph, p. 119.

* On the composition of asphalt, see also H. Endemann, Jour. Soc. Chem. Ind., vol. 10,1897, 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 nattirlichen 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 anH. asphalt in Hungary. Memoirs on the proximate composition of petroleum are 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 Pelouzo and Cahours in France, of Schorlemmer in England, of Markownikoff in Russia, and of others in nearly every country of Europe. «an not 

be given the consideration here which is properly due them.

a Jour. Am. Chem. Soc., vol. 32,1910, p. 1032.

101381° Bull. 491 11 44 /' ' '%
690 THE DATA OF GEOCHEMISTRY.

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 1 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 CnH2nBr2 . In hydrogen evolved from spiegeleisen Hahn found still higher hydrocarbons, up to C16H32 . These 

were collected by direct condensation in wash bottles without the 

use of bromine.

In 1873 similar experiments were reported by F. H. Williams,2 

who dissolved spiegeleisen in hydrochloric acid. The gas evolved 

was passed through tubes immersed in a freezing mixture, and afterwards through bromine. In one experiment 7,430 grams of 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. Cloe'z,3 

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.

1 Liebig's Annalen, vol. 129,1864, p. 57. Hahn gives references to the earlier investigations.

2 Am. Jour. Sci., 3d ser., vol. 6,1873, p. 363.

3 Compt. Rend., vol. 78,1874, p. 1565; vol. 85,1877, p. 1003; vol. 80,1878, p. 1248.
THE NATURAL HYDROCARBONS. 691

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: 1

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 

largely of olefines, with some members of the acetylene series and 

some saturated compounds.

According to R. Salvadori,2 hydrocarbons can be generated by 

heating together calcium carbide and ammonium chloride; an 

observation which has been confirmed by A. Brun.3 Furthermore, 

G. Steiger, in the laboratory of the United States Geological Survey, 

obtained bath 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 the6nes of petroleum formation will be discussed later.

It will bv observed that acetylene is a common product of these 

reactions. But acetylene is not a constituent of petroleum. P. 

Sabatier and J. B. Senderens, 4 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 5 long ago proved that acetylene, 

when heated to the temperature at which glass begins to soften, poly-

' See H. Moissan, Compt. Rend., vol. 122,1896, p. 1462. Also a summary by J. A. Mathews, Jour. Am. 

Chem. Soc., vol. 21,1899, p. 647. Berthelot (Compt. Rend., vol. 132,1901, p. 281) has discussed the reactions 

thermochemically.

2 Gazz. chim. Hal., vol. 32,1902, p. 496.

s Arch. sci. phys. nat., 4th ser., vol. 27,19C9, p. 113.

4 Compt. Rend., vol. 134,1903, p. 1185. Similar results to those of Sabatier and Senderens have also been 

obtained by K. Charitschkofl, Chem. Zentralbl., 1907, p. 294.

6 Annales chim. phys., 4th ser., vol. 12,1867, p. 52.
692 THE DATA OF GEOCHEMISTEY.

merizes 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 :

2C6H9 2H=C12H10 + H2

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 hi an atmosphere of 

hydrogen, acetylene is produced a reaction discovered by Berthelot.1 

According to W. A. Bone and D. S. Jerdan,2 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. 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 3 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 4 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 5 were announced. He 

distilled menhaden oil, unsapcinified, 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 

C7H16 . In a later memoir 6 he mentions the isolation of normal 

octane and nonane, with secondary hexane, heptane, and octane. In a 

still later research with T. Lehmann7 he also obtained olefines from 

C6H12 up to C9H18 and some derivatives of the benzene series. These

1 Annaleschim. phys.,3dser., vol. 67,1863, p. 64.

2 Jour. Chem. Soc., vol. 71,1897,p.41; vol. 79,1901, p. 1042. See also J.N.Pring and R.S. Hutton.idsm, 

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.

3 Mem. Am. Acad., 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 

is often, loosely, so used.

& Ber. Deutsch. chem. Gesell., vol. 21,1888, p. 1816. 

e Idem, vol. 22,1889, p. 592. 

' Idem, vol. 30,1897, p. 2365.
THE NATURAL HYDBOCABBONS. 693

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 his crude product Engler also prepared 

an illuminating oil, practically indistinguishable from commercial 

kerosene. 1

Analogous experiments, but with a somewhat different purpose, 

were carried out by W. C. Day.2 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. 1 

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 elaterite. Wood alone gave a similar oil, with 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,3 for example, established this fact with 

regard to linseed oil, but the nature of the product was not completely 

determined. Engler 4 obtained hydrocarbons by the distillation of 

colza and olive oils, as well as from fish oil, butter, and beeswax. 

Furthermore, J. Marcusson 5 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.

1 Observations confirmed by Redwood, Petroleum and its products, 2d ed., vol. 1, p. 259.

2 Am. Chem. Jour:, vol. 21,1899, p. 478. 

s Proc. Am. Philos. Soc., vol. 36, p. 93. 

0 Cong. internal, du pStrole, Paris, 1900, p. 20. 

t Chem. Zeitung, vol. 30,1900, p. 789.
694 THE DATA OF GEOCHEMTSTEY.

They were speculations, nothing more. The modern era begins with a 

memoir by M. Berthelot,1 published in 1866.

Berthelot started from a supposition of Daubree 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,2 which 

has no present value, we come next to the famous carbide theory of 

D. Mendeleef,3 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.

Mendele"ef's hypothesis naturally attracted much attention and 

was rendered plausible by researches like those of Hahn, Williams, 

and Cloe'z 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 4 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 5 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,6 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,7 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

1 Annales chim. phys., 4th ser., vol. 9, 1866, p. 481.

2 Compt. Rend., vol. 73,1871, p. 611. A later, separate brochure by Byasson I have not seen, 

s Ber. Deutsch. chem. Gesell., vol. 10,1877, p. 229; Jour. Chem. Soc., vol. 32, p. 283. See also Mendeleef's 

Principles of chemistry, English translation, vol. 1, 1891, pp. 364-366. 

< Compt. Rend., vol. 122,1896, p. 1462. See also S. Meunier, idem, vol. 123,1896, p. 1327. 

5 See ante, Chapter VIII.

o Gazz. chim. ital., vol. 7, 1877, p. 1; vol. 12, 1882, p. 9. 

7 Arch. sci. phys. nat., 4th ser., vol. 27,1909, p. 113.
THE NATURAL HYDROCARBONS. 695

adjacent sedimentary rocks. The same considerations also apply 

to the petroleum field near Tampico, Mexico, as described by E. 

Ordonez,1 which is cited by E. Coste 2 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.

A different line of investigation relative to the genesis of petroleum 

is that proposed tentatively by G. F. Becker.3 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,4 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,5 cases in which the possibility 

of an organic origin seems to be absolutely excluded.

The other speculation is that of 0. C. D. Ross,6 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

1 Min. Sci. Press, vol. 95,1907, p. 249.

2 Jour. Canadian Min. lust., vcl. 12,1909, p. 273. For earlier papers by Coste see the same journal, vol. 0, 

1903, p. 73, and Trans. Am. lust. 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.

3 Bull. U. S. Geol. Survey No. 401,1909.

« Bull. Soc. imp. nat. Moscou, new scr., vol. 3,1890°, p. 720.

& See F. Wohler, Liebig's Annalen, vol. 109,1859, p. 349, on carbon compounds in the meteorite of Kaba, 

Hungary. Also S. Meunicr, Compt. Rend., vol. 109,1389, p. 976, on the meteorite of Mighei, Russia. A. E. 

NordensMold (Pogg. Annalen, vol. 141,1870, p. 205) found carbonaceous matter in the meteorite of Hessle, 

Sweden; and G. Tschermak (Sitzungsb. 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. Cloez, Compt. Rend., vol. 

59,1864, p. 37. Graphite and amorphous carbon are common in meteorites, and in some falls diamonds 

have been found.

6 Chem. News, vol. 04,1891, p. 14. A criticism by Redwood appears on p. 215.
696 ?H'E DATA OF GEOCHEMISTRY.

within the earth represents an effort in the same direction. An illustration of this implication is to be found in Lenicque's remarkable 

memoir/ which was cited in Chapter II of this volume. 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 solf ataric 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 2 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

» M6m. Soc.'ingen. civils France, October, 1903, p. 346.

* 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.
THE NAlUBAL HYDROCARBONS. 69*7

studied experimentally. F. Hoppe-Seyler 1 and H. Tappeiner 2 have 

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,3 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, after 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.4 Engler 5 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 6 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 7 holds 

that the changes are always in the opposite direction and that the 

more complex hydrocarbons are formed first, partially breaking

1 Ber. Deutsch. chem. Gesell., vol. 16,1883, p. 122.

2 Idem, pp. 1734,1740. See also L. Popofi, abstract in Jour. Chem. Soc., vol. 28,1875, p. 1209, on gas from 

river mud near sewer openings.

a Am. Chem. Jour., vol. 16,1894, p. 427.

« For a very complete summary of all the hypotheses relative to the formation of petroleum, see H6fer, 

Das ErdSl, 1906, pp. 160-229. See also Redwood, Petroleum and its products, vol. 1,1906, pp. 250-261. 

Other summaries are by Aisinmann, Zeitschr. angew. Chemie, 1893, p. 739; idem, 1894, p. 122; C. Klement, 

Bull. Soc. beige g<5ol., vol. ll.proc. verb., 1897, p. 76; R. Zuber, Zeitschr.prakt. Geologic, 1898,p.84; and E. 

Orton, Bull. Geol. Soc. America,vol. 9,1897, p. 85. Very recent memoirs on the subject are by P. De Wilde, 

Arch. sci. phys. nat., 4th ser., vol. 23,1907, p. 559, and C. Neuberg, Sitzungsb. K.preuss. Akad., May 16, 

1907.

* Ber. Deutsch. chem. Gesell., vol. 30, 1897, p. 2358. For more recent articles by Engler see Zeitschr. 

angew. Chemie, vol. 21,1908, p. 1585; Verhandl. naturwiss. Vereins, Karlsruhe, 1908, vol. 20, p. 65; and 

Compt. rend. Cong. internat. pe'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. BCttcher 

(Ber. Deutsch. chem. Gesell., vol. 20.1887, p. 595), in their comparison of the hydrocarbons contained in 

petroleum and coal oil or tar. H. Monke and F. Beyschlag (Zeitschr. prakt. Geologie, 1905, pp. 1,65, 421) 

emphasize the putrefactive process, which yields petroleum, as compared with the carbonizing process, 

which forms coal.

' Jour. Am. Chem. Soc., yol. 2S, 1906, p. 429.
698 THE DATA OF GEOCHEMISTRY.

down afterward into lower members of the series. J. Marcusson 1 

holds the same view. The putrefactive removal of the albuminoid 

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. Dieulafait 2 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 3 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,4 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,5 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 6 in his studies of Roumanian petroleum. F. 

Heusler 7 also, while indorsing Engler's principal conclusions, 

invoked the aid of aluminum chloride as an agent in effecting

1 Chem. Zeitung, vol. 30,1906, p. 788.

2 Cited by A.Jaccard, Arch. sci. phys. nat., 3d ser., vol. 24,1890, p. 106.

a Ber. Deutsch. chem. Gesell., vol. 33,1900, p. 16. See also Cong. internal du petrole, 1900, p. 30.

4 Cited by Hofer, Das Erdol, 1906, p. 219. F. Hornung (Zeitschr. Deutsch. geol. Gesell., vol. 57, Monatsber., 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. Hal., vol. 25,1906, p. 795. Pantanelli seems to favor the inorganic origin of petro. 

leum.

& Chem. Zeitung, vol. 15,1891, p. 935, and Zeitschr. Deutsch. geol. Gesell., vol. 48,1896, p. 239. See also 

his papers cited in Chapter VII, ante. '

8 Compt. rend. Cong. internal. p6trole, Bucarest, 1910, vol. 2, p. 80. Also L'industri'e du pStrole en 

Roumanie, Bucarest, 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. On the animal origin of petroleum see also L. 

Singer, Inaug. Diss., Zurich, 1893.

' Zeitschr'. angew. Chemie, 1896, pp. 288,3is. '
THE NATURAL HYDROCARBONS. 699

a polymerization of the hydrocarbons. According to Ochsenius's 

theory, magnesium 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 in 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 0. 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 which the oil is to be produced. The beds of sulphur which occur 

adjacent to some oil wells, notably in Texas, were probably formed 

by 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 have taken as evidence of former volcanism,

1 A possible exception to this statement is cited by Ochsenius (Zeitschr. Deutsch. gcol. Gesell., vol. 48,

1896. p. 239), who mentions a water containing, hi its solid residue, 23.91 per cent of A1C13 . This water 

accompanied a petroleum.

2 Chem. Zeitung, vol. 15,1891, p. 1203.

s Idem, p. 1582.

< Bull. Soc. sci. nat. Neuchatel, vol. 8,1868, p. 58. See also F. C. Phillips, Proc. Am. Phil. Soc., vol. 36,

1897. p. 121, on petroleum inclosed in fossils.

s The waters accompanying the naphtha of the Grosny district, Russia, as analyzed recently by K. 

Charitschkoff (Chem. Zeitung, 1907, p. 295), appear to be exceptional. In these sodium carbonate is more 

abundant than the chloride, and salts of ammonium and the amines are also present.
700 THE DATA OF GEOCHEMISTRY.

is much more simply interpreted, both chemically and geologically, 

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 latter as a 

probable source of this particular oil.

Data of this class might be multiplied almost indefinitely. For 

instance, C. E. Bertrand and B. Renault 5 have shown that Boghead 

mineral, torbanite, and kerosene shale, from which oils are distilled, 

are derived from gelatinous algae, 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. sci. nat. Neuchatel, vol. 7,1866, p. 234.

2 See discussion following Lesquereux's communication.

s Petroleum and its products, 2d ed., vol. 1, pp. 126,142.

«Bull. California State Mining 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.

o Compt. Rend., vol. 117,1893, p. 593, See also Bertrand, Compt. rend. VIII. Cong. ge"ol. internat., 1900, 

p. 458. According to E. C. Jeffrey (Proc. Am. Acad., vol. 46,1910, p. 273), the supposed gelatinous algifi 

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. Rept. Ohio State Board Agr., 1859, p. 605.

1 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 polymerization of petroleum 

may itself generate heat.
THE NATURAL HYDBOCABBONS. 701

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

1 Published in Trans. Manchester Geol. Soc., vol. 8, 1868, p. 41. Curiously, a later paper by Binney 

appears earlier, namely, in vol. 3,1860, p. 9.

2 Annals New York Acad. Sci,, vol. 2,1882, p. 277. 

a Chem. Zeitung, vol. 23,1899, p. 144. Also note In vol. 30,1906, p. 18.

< Ber. Deutsch. chem. Gesell., vol. 32,1899, p. 2940; vol. 35,1902, p. 1212. Criticism by Engler in vol. 33, 

1900, p. 7.

8 See also C. E. Guignet, Compt. Bend., vol. 91,1880, p. 888, on wax from peat. 

8 Natur. Wochenschr., vol. 20,1905, p. 599.
702 THE DATA OF GEOCHEMISTRY.

source, it is well to remember the enormous accumulation of "oozes," 

namely, the radiolarian and globigerina oozes, on the bottom of the 

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 kind 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

1 These oceanic sediments are especially noticed by Engler in a paper read before the petroleum congress 

5n 1900 (Cong. internat. du pfitrole, Paris, 1900, p. 28). In A. Beeby Thompson's monograph, The oil fields 

of Russia, London, 1904, pp. 85-87, a theory is developed to account for the probable formation of bitumens 

on the sea bottom. Thompson regards fish remains as an important source of supply. G. P. Mikhailovski 

(Bull. Com. geol. St. Petersburg, vol. 25,1908, p. 319) derives the Caucasian petroleum from marine sedi. 

ments. C. B. Morrey (Bull. Geol. Survey Ohio No. 1,1903, p. 313) suggests that bacteria have been the 

chief agents in transforming other organic matter into hydrocarbons.

2 Eclog. Geol. Helvet., vol. 2,1890, p. 87. See also Arch. sci. phys. nat., 3d ser., vol. 23,1890, p. 501; vol. 

24,1890, p. 106. Jaccard studied especially the bitumens of the Jura.

' 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. Kept. 

Indiana Dept. Geol. and Nat. Hist., 1888; W. S. Blatchley, idem, Twenty-eighth Ann. Eept., 1904; E. 

Haworth, Kansas Univ. Geol. Survey, vol. 1,1896, p. 232; H. P. H. Brumell Geol. Survey Canada, new 

ser., Ann. Kept. 5, Q, 1893; and W J McGee, Eleventh Ann. Kept. U. S. Geol. Survey, pt. 1,1891, p. 589. 

L. Harperath (Bol. Acad. nac. cien. C<5rdoba (Argentina), vol. 18,1905, p. 153) has published a long memoir 

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.
THE NATURAL HYDROCARBONS. 703

to its vegetable equivalent, phytosterin.1 Apart from this detail the 

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 2 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 

thickness of 500 feet, would yield about 2,500,000 barrels of oil. 

Even more striking are the figures given by T. Sterry Hunt,3 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

»See M. Rakusin, Chem. Zeitung, vol. 30,1906, p. 1041; Ber. Deutsch. chem. Gesell., vol. 42,1908, pp. 

1211,1640,4675; J. Marcusson, Chem. Zeitung, vol. 31,1907, p. 419; vol. 32,1908, pp. 377,391; R. Albrecht, 

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. Zeitung, vol. 31, 1907, pp. 1155, 1170) question the 

cholesterin theory and favor that of Potonifi. See also Zaloziecki, Compt. rend. Gong, internat. petrole, 

Bucarest, 1910, p. 718.

«First Ann. Kept. Geol. Survey Ohio, 1890, chapter 11; Geoh Survey Kentucky, Report on occurrence 

of petroleum, etc., 1888-89.

3 Chemical and geological essays, 1875, p. 168.
704 THE DATA OF GEOCHEMISTRY.

materials have yielded the different products. On this class of problems the chemist, the geologist, and the paleologist must work 

together. Physics also is entitled to be heard; for, as D. T. Day 1 

has shown, petroleum, by simple filtration through fuller's earth, can 

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. i

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.2 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. Sokoloff's 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. 3

i Cong. internat. pgtrole, Paris, 1900, p. 53. See also J. E. Gilpin and O. E. Bransky, Am. Chem. Jour., 

vol. 44,1910, p. 251. These authors show that fuller's earth exerts a selective absorption for unsaturated 

hydrocarbons and organic sulphides.

' For a discussion of this problem, see H. Hofer, Das Erdol, 1906, p. 223. Also G. I. Adams, Trans. Am. 

Inst. Min. Eng., vol. 33,1903,p.340;andD. T. Day, idem, p. 1053. Orton's reports, previously cited, contain important contributions on this theme.

3 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.
CHAPTER XVII.

COAL. 

ORIGIN OF COAL.

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 form 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 

C6H10 05 , 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 subi The formula CeHioOs represents only the empirical composition of cellulose, and not its true molecular 

weight. According to A. Nastukofl (Ber. Deutsch. chem. Gesell., vol. 33,1900, p. 2237), the true formula 

is probably 40CeHio05, or CwoHwoOsoo- 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. Hofimann, Beitr. Geophys., vol. 7,1905, p. 327.

101381° Bull. 491 11 45 705
706 THE DATA OF GEOCHEMISTBY.

stance to be considered, but it is the most important one, and its 

ultimate composition has been well determined. Its proximate composition is not so clearly known, but certain available facts are pertinent to the present discussion. It contains cellulose, C6H10 05 , 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 Bevan, 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 either definite compound alone. The data are as follows:

Composition of cellulose, lignocellulose, and wood.

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 Petersen and Schodler, Liebig's Annalen, vol. 17,1836, p. 139: Samples dried and finely powdered.

D. Average of thirty-six analyses of five different woods* by E. Chevandier, Annales chim. phys., 3d 

ser., vol. 10,1844, p. 129. Samples dried in vacuo at 140°.

E. Averageof eight analyses of woods by W. Baer, Jahresber. Chemie, 1847-48, p. 1112. Ash from 0.53 to 

2.03 per cent.

F. Average of seven Danish woods, analyzed by E. Gottlieb, Jour. Chem. Soc., vol. 46, 1884, p. 477 

(abstract). Dried at 115°.

G. Average composition of five acrogen plants, of the genera Lycopodium, Equisetum, Aspidium, and 

Cyathea, by G. W. Hawes, Am. Jour. Sci., 3d ser., vol. 7,1874, p. 585. In Equisetum the ash ran as high 

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

G

48.83

6.37

4480

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, but Gottlieb obtained only 0.04 to 0.10. In Hawes's analysis 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 C6H904 , and that expression might be

i 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. 

* Jour. Chem. Soc., vol. 55,1889; p. 199.
COAL. 707

used were wood a definite substance. Its employment, however, is 

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 succesive 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 

fermentative heat and to a gradually increasing pressure. The vegetation was doubtless 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 6f 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 undoubedly 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 algae are really the spores of vascular cryptogams.

A moment's consideration will suffice to show that the process of 

decay could not have been uniform. The softer plant tissues 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.

1 Die Enstehung der Stelnkohle, Berlin, 1910. See also citation in the preceding chapter, and the references to the work of Bertrand and Renault. Also H. Stremme, Monatsber. Deutsch. geol. Gesell., vol. 59, 

1907,p. 153.

2 Proc. Am. Acad., vol. 46,1910, p. 273.
708 THE DATA OF GEOCHEMISTRY.

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 .9H2O. 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.

PEAT.

The first stage in the development of coal 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 plants 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; still deeper, we find a black, semigelatinous substance from which the vegetable structure has largely disappeared.1 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 2 is especially 

suggestive. The samples were dried at 100°, and the analyses calculated on an ash-free basis.

Analyses of sphagnum and peat.

A. Sphagnum, the chief plant of the peat bogs. 

B. Light peat, near surface. 

C. Light peat.

D. Moderately light peat.

E, F. Black peat.

G. Heavy brown peat.

c........... ...........

H.. .................. o...... ...............

N. ........ ............

A

49.88

6.54

42.42

1.16

100. 00

B

50.33

5.99

42.63

1.05

100. 00

C

50.86

5.80

42.57

.77

100. 00

D

59.71

5.27

32.07

2.95

100. 00

E

59.70

5.70

33.04

1.56

100. 00

F

59.71

5.27

32.07

2. '95

100. 00

G

62.54

6.81

29.24

1.41

100.00

1 On the rapidity of formation of peat, see a summary by G. H. Ashley, Econ. Geology, vol. 2,1907, p. 34.

2 Jour, prakt. Chemie, vol. 92,1864, p. 65.
COAL. 709

The progressive increase in carbon in passing from sphagnum to 

heavy peat is clearly shown. 

A few other analyses of peat may be profitably cited, as follows: 1

Analyses of peat.

A. From Thesy, France. Analysis by Marsilly, Annales des mines, 5th ser., vol. 12, p. 406. Dried 24 

hours in vacuo.

B. From Camon, France. Also by Marsilly, who gives seven analyses in all. Dried 24 hours in vacuo.

C. From "Hb'r in Schonen." Analysis by O.'Jacobsen, Liebig's Annalen, vol. 157,1871, p. 240. Dried 

at 100°.

D. From a lake in Cashmere. Analysis by C. Tookey. See Percy's Metallurgy, vol. 1,1875, p. 206.

E. Average of ten analyses cited by Roth, Allgem. chem. Geol., vol. 2, p. 642.

c.................. ....................

H........ ............................ o....................................

N.......................................

Ash..................................

A

50.67

5.76

34.95

1 Q?

6.70

100. 00

B

46.11

5.99

35.87

2.63

9.40

100. 00

C

51.38

6.49

35.43

1.68

5.02

100. 00

D

37.15

4.08

23.48

2.02

33.27

100. 00

E

51.97

6.05

34.02

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 ash-free basis.

c........................ ..............

H.... ...... ..........................

0....................................

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

35.19

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 animal 

matter.

The nature of the changes which have taken place in the transformation of vegetable matter into peat are partly understood. When 

ligneous fiber decays it yields an amorphous mixture of substances 

which are known as the humus acids, humic, ulmic, crenic, and apocrenic acids being specific names. These acids are very ill-defined

1 For still other analyses, see Roth and Percy, as cited, and vol. 1 of Groves 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. 

Petersen and Nessler (Neues Jahrb., 1881, p. 82) give 17 ultimate analyses of German peat, with separate 

analyses of the ash. In a paper by H. B. Kummel (Econ. Geology, vol. 2, 1907, p. 24), there are many 

technical analyses of New Jersey peat, with calorimetric data. On the mechanism of peat formation, see 

N. S. Shaler, Sixteenth Ann. Kept. U. S. Geol. Survey, pt. 4,1895, p. 305. An important general paper on 

peat, its rate of growth, its resins, etc., by R. Angus Smith, is given in Mem. Lit. Phil. Soc. Manchester, 

1876, p. 281. See also T. R. Jones, Proc. Geologists' Assoc., vol. 6,1880, p. 207, and C. A. Davis, Kept. State 

Board Geol. Survey Michigan, 1906, p. 97 and Econ. Geology, vol. 5,1910, p. 37.
710 THE DATA OF GEOCHEMISTRY.

bodies, and various formulae have been assigned to them, but none 

can be said to be established. The acids dissolve in alkaline solutions, and so are partly washed away; but the salts formed with lime 

and iron probably remain, being insoluble, behind. The ash of peat 

is commonly rich hi lime, not as carbonate, and also in iron, the latter 

appearing often in large beds of bog ore. The formation of the 

humus acids 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 as 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 the humic substance, with 30 to 60 of fiber. Two of 

his analyses are as follows:

Analyses of peat (Borntrager).

A. Light-colored peat, Hannover. Mean of two analyses. 

B. Black peat, Oldenburg.

Water..........................................................

Ash............................................................

Fiber..........................................................

Humus acids. ..................................................

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 in 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 Obburgen, 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. See 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. Chemle, vol. 39,1900, p. 694; vol. 40,1901, p. 639.

* 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. Reichsanstalt, vol. 15,1885, p. 283.
COAL.

Average composition of dopplerite.

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 C30H54 , and L. Spiegel has argued.in favor 

of C18H30 . 4 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 drift. Dawson 6 mentions peat underlying bowlder 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

»Ber. Deutsch. chem. Gesell., vol. 15,1882, p. 2961.

2 Liebig's Annalen, vol. 157, 1871, p. 240. See also Mulder, idem, vol. 32, 1839, p. 305.

»On flchtelite, see 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.

«Eeduced to simpler, comparable terms, these formulae become, respectively, Ci6Hs7 and C^H^. The 

difference is slight.

» See G. H. Ashley, Econ. Geology, vol. 2,1907, p. 34.

«Acadian geology, 2d ed., p. 68. ( '

' See T. H. MacBride, Proc. Iowa Acad., vol. 4,1897, p. 63; and T. E. Savage, idem, vol. 11,1903, p. 103.

8 On American peats, see H. Ries, Fifty-fifth Ann. Kept. 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. W. Parmelee describe peat deposits 

and give a bibliography of the subject. See also R. Chalmers, 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.
712 THE DATA OF 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, 

produced 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 variety, 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, 

i

A. From Teudi,tz, Germany. Analysis by Wagner.

B. From Sardinia. Analyst not named.

C. From Schonfeld, Bohemia. 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

B

63.71

5.05

31.24

100. 00

C

69.82

5.90

24.28

100. 00

D

75.08

5.44

19.48

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. Daubr6e,.Compt. Rend., vol. 19, 1844, p. 126, on "mineral charcoal" from the 

Saarbriicken coal field.

3 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. 29,1883, p. 382. The latter memoir contains 

many other analyses of fossil combustibles. v

<1875 edition, vol. 1, pp. 312-313. From a table of 41 analyses.
COAL. 713

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, Alameda County, California.

D. Lignite from Wyoming.

E. Black lignite from Red Lodge, Montana. A coal of doubtful character. Not certainly lignite.

Moisture.. . ...........................

Fixed carbon ........................

Ash. .................................

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

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

39.56

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, moisture, and 

sulphur are thrown out, show less variation.

Elementary analyses of American lignites.

,

C. ...................................

H. ...................................

N. ..................................

0....................................

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

D

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 quisqueite, tasmanite, and trinkerite are rich in 

organic sulphur compounds of undetermined character. See Dana, System of mineralogy, 6th ed., p. 1010.

2 Prof. Paper No. 48,pt. 1, and Bull. No. 290,1906. Analyses made under the direction of E. E. Somermeler.
714 THE 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 Geol. 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... ..................................................

0.....................................................

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 behavior toward reagents the lignites are more akin to 

peat than to the Carboniferous coals. Like peat, they contain mimic 

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 mimic bodies are found in 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 

Erganzung, published at Halle in 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 Brennstoffe, 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 E. Donath, Zeitschr. anorg. Chemie, 1906, p. 657.

»Jour. Soc. Chem. Ind., 1891, p. 975.

< Compt. Rend., vol. 52,1861, p. 114.

* See R. Zeiller, Bull. Soc. g6ol. France, 3d ser., vol. 12,1884, p. 680.

s Verhandl. K.-k. geol. Reichsanstalt, p. 64,1891.
COAL: 715

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, 

and similar observations were recorded by R. 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. Chemie, 2d ser., vol. 70,1904, 

p. 509.

2 Compt. Rend,, vol. 88, 1879, p. 590.

» Proc. Chem. Soc., vol. 8,1892, p. 9. W. C. Anderson and J. Roberts (Jour. Soc. Chem. Ind., vol. 17, 

1898, p. 1013) have also studied the action of nitric acid on coal, and made several analyses of the "coal 

acids "so ob tamed.

«Ann. Rept. Brit. Assoc., 1894, p. 246; idem, 189C, p. 340.

6JDonath, Chem. Zeitung, 1905, p. 1027, and Zeitschr. anorg. Chemie, 1906, p. 057. Donath and H. Ditz, 

Oesterr. Zeitschr. Berg- u. Huttenw., vol. 51,1903, p. 310. Donath and F. Braunlich, Chem. Zeitung, 1904, 

pp. 180, 953. . '
716 THE DATA OF GEOCHEMISTBY.

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 metamorphism 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 brown coals, so that it is not always easy to say where the one 

group ends and the other begins. The following analyses of bituminous coals, all of Carboniferous age, are taken from the reports of the 

fuel-testing 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 analyses: 

Proximate analyses of bituminous coals.

A. Ehrenfeld, Pennsylvania. Bull. No. 290, p. 179. 

B. Bruce, Pennsylvania. Idem, p. 184. 

C. Vigo County, Indiana. Idem, p. 109.

D. Altoona, Iowa. Prof. Paper No. 48, p. 223. 

E. Shawnee, Ohio. Bull. No. 290, p. 145. 

F. Staunton, Illinois. Idem, p. 63.

Ash...........................

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

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

Q Qfl

33.66

44.86

11.58

100. 00 

1.81

F

13.72

36.24

39.72

10.32

100. 00 

3.96

i 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.
COAL. 717

With one exception the volatilizable part of these coals 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. ..........................

0.. ..........................

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

10.75

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 1 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 Unser Fritz mine.

c............................

H............................

N. ..........................

0-. ..........................

85.33

5.20

1.49

7.98

100. 00

85.06

4.66

1.35

8.93

100. 00

84.28

4.85

1.87

9.00

100. 00

82.34

4.94

1.18

11.54

100. 00

80.69

4 Q4

1.29

13.08

100. 00

83.81

4 Q8

1.47

q 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 Commentry, France, by S. Meunier, in 

Fremy's Encyclopedic chimique, vol. 2 (Complement, 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 Tyneside cannel, by H. Taylor, Edinburgh New Phil. 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. angew. Chemie, 1894, p. 605. See also his Chemische Technologie der Brennstoffe, vol. 1, pp. 

518-520.
718 THE 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 high. 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 Brennstofle, 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

9.90

100. 00

C

83.65

5.48

1.86

9.01

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.

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

' Am. Jour. Sci.,2dser.,vol. 23,1854, p. 212. J. Rofe (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.-13S) regards 

cannel as formed from the spores of cryptogams. No algae are found in it, or very few. See also E. C. 

Jeffrey, Proc. Am. Acad., vol. 46,1910, p. 273.
COAL. 719

graphite. The technical analyses of anthracite show a large proportion of fixed carbon, with relatively little volatilizable matter a 

relation which appears in the following table:

Proximate analyses of anthracite.

A. Semianthracite, Coal Hill, Arkansas. From report of the coal-testiug plant, Prof. Paper U. S. Geol. 

Survey No. 48,1906, p. 202.

B. Anthracite culm, Scranton, Pennsylvania. Idem, p. 245.

C. Lykens Valley, Pennsylvania.

!D. Schuylkill coal, Pennsylvania.

E. Cameron coal, Pennsylvania. Analyses C, D, and E by A. S. McCreath, Rept. Second Geol. Survey 

Pennsylvania, vol. MM. This volume contains many other proximate analyses of coals. See also C. A. 

Ashburner, Trans. Am. Inst. Min. Eng., vol. 14,1875-76, p. 706, 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

1.28

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. Geol. Soc., vol. 1,1845, 

p. 204.

E. From Province of Hunan, China. , Analysis by F. Haeussermann and W. Naschold, Zeitschr. angew. 

Chemie, 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 Vortrage, 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.....................

O. ...................

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

1.00

1.88

100. 00

D

94.63

2.73

1.36

1.28

100. 00

E

94.68

2.29

.76

2.27

100.00

F

97.46

.61

qc

1.58

100. 00

G

no en

2 81

Q7

o 70

100. 00

Anthracite, however, is not the extreme end of the coal series. 

There are pre-Carboniferous coals, which are found only in small 

quantities, and which approach still more closely to pure carbon.
720 THE DATA OF GEOCHEMISTRY.

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 the Cambrian. Ellis 

gives partial analyses of anthraxolites from three other localities. See also A. P. Coleman, Sixth Ann. 

Kept. Ontario 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, pt. 1, p. 97; see also the same journal for 1886, pt. 1, p. 92. 

Found in the Huronian.

D. Graphitoid, from the mica schist and phyllite of the Erzgebirge. Analysis by A. Sauer, Zeitschr. 

Deutsch. geol. Gesell., vol. 37,1885, p. 441.

c.... .........................................

H.......... ...................................

N. ...........................................

s. ........................................... 0.............................:...............

H20............ ...............................

AaVi

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

1.01

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. ........................................... o........... ..................................

A

91.53

4.22

.53

3.72

100. 00

B

96.69

.53

1.05

1 73

100. 00

c

QQ 19

.44

.44

100. 00

D

QQ 7fi

.24

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 CUH405 . The amorphous carbons do not yield this derivative, and Inostranzeff failed to obtain it 

from schungite. The approach to graphite, therefore, is empirical 

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.

1 See B. C. Brodie, Liebig's Annalen, vol. 114,1860, p. 6.
COAL. 

THE VARIATIONS OF COAL.

721

For comparison of all the fuels, starting with wooa 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 and Hawes.

Average composition of fuels.

Wood. ........................................

Peat. .........................................

Lignite. ......................................

Bituminous coal. ..............................

A n tVi ro r\ IP

C

49.65

55.44

72.95

84.24

93.50

H

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. .........................................

Lignite. ......................................

Bituminous coal. ..............................

Anthracite. ...................................

C

100

100

100

100

100

H

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 reference 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, C6H1005 , 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.

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 

101381° Bull. 491 11 46
722 THE DATA OP GEOCHEMISTRY.

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, free 

hydrogen, 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. Frankland2 found the following range of variations 

in the percentages of the principal constituents:

Variations in composition of coal gas.

C02 .................................................... Oto 2.73

02 ...................-.....-......--.................. Oto 1.00

N2 .................................................... 2.07 to 10.84

H2 .................................................... 33.24 to 53.79

GO................................................... 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. Parr4 has 

proposed a technical classification of these fuels which differs essentially from the system above mentioned. His scheme is based upon 

the ratio between the total carbon and the carbon of the volatile

1 See, for example, P. Frazer, Trans. Am. Inst. Min. Eng., vol. 6,1877-78, p. 430, and C. A. Ashburner, 

idem, vol. 14,1885-86, p. 706.

2 Jour. Soc. Chem. Ind., vol. 3,1884, p. 273.

s 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 Jouv. Am. Chem. Soc., vol. 28,1906, p. 1425.
COAL. 723

matter, which latter is largely but not wholly combustible. He also 

bakes 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 their 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 

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:

C02 .......................................................... 2.97

CH4 ......................................................... 43.36 '

N2 ......................................................... 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°, 

and 200°, successively, they consist principally of carbon dioxide, with

i Prof. Paper U. S. Geol. Survey No. 48,1906, pp. 156-173. See also P. Frazer, Bull. Am. Inst. Mln. Eng., 

March, 1906; L. P. Breckenridge, Bull. U. S. Geol. Survey No. 325,1907, p. 68.

a Jour, prakt. Chemie, vol. 92,1864, p. 76.

3 Jour. Chem. Soc., vol. 32,1877, p. 146. See also Zitowitsch, Jour, prakt. Chemie, 2d ser., vol. 6,1873, p. 79, 

on gases from Bohemian lignites.
724 THB DATA OF GEOCHEMISTRY.

subordinate carbon monoxide and nitrogen, and insignificant proportions of oxygen and hydrocarbons. The following examples are sufficient to show the general nature of his analyses:

Analyses of gases from lignite.

A. Gas from Bohemian lignite, extracted at 100°.

B. Gas from Bovey Heathfleld lignite at 50°; 100 grams of coal gave 56.1 cubic centimeters of gas.

C. Gas from the same coal at 100°, 59.9 cubic centimeters.

D. Steam coal. 147.4 cubic centimeters gas.

E. Gas evolved from sample D on heating to 200°.

C02 . .................................

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

CH4 ..................................

defines .............................

02 ........ ..........................

A

96.41

1.20

.32

2.17

olOO. 10

B

87.25

3.59

.24

8.92

100. 00

C

89.53

5.11

.33

5.03

100. 00

D

96.05

3.20

.33

.42

100. 00

E

86.30

7.41

3.34

2.08

.53

.34

100. 00

a The error in summation is probably due 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 1 examined the gases extracted in 

vacuo at 100° from cannel coal and jet. The analyses are subjoined, 

with a statement of the volume of gas yielded by 100 grams of each

sample.

Analyses of gases from cannel coal and jet.

A. Wigan cannel. 421.3 cubic centimeters gas.

B. Wigan cannel. 350.6 cubic centimeters gas.

C. Scotch cannel, Wilsontown. 16.8 cubic centimeters gas.

D. Scotch cannel, Lesmahago. 55.7 cubic centimeters gas.

E. Cannel shale, Lasswade, near Edinburgh. 55.7 cubic centimeters gas.

F. Whitbyjet. 30.2 cubic centimeters gas.

coa ..... ....................

CH4 ........................

r\ TT OH8 ... ....................

O4J1 jo .......................

A

6.44

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

.91

14.54

100. 00

E

68.75

2.67

28.58

100. 00

F

10.93

86.90

2.17

100. 00

1 Jour. Chem. Soc., vol. 30,1876, p. 144,
COAL. 725

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 1 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. 600.6 cubic centimeters gas. 

G. Anthracite. 655.5 cubic centimete-s gas.

C02 . .................

CH4 . .................

02 ....................

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

G

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 be easily 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

i Jour, prakt. Chemie, 2d ser., vol. 5,1872, pp. 144, 407; vol. 6,1873, p. 389. Data reproduced in Percy's 

Metallurgy, vol. 1,1875, p. 283.

«Trans. North of England Inst. Min. Mech. Eng., vol. 37, p. 246. 

" Jour. Soc. Chem. Ind., vol. 13,1894, p. 25. 

< Jour. Chem. Soc., vol. 28,1876, p. 793.
726 THE DATA OF GEOCHEMISTRY.

other hand, will lose much. So we see that the bituminous coals contain, as a rule, less gas in the laboratory than the anthracites, although 

the bituminous mines are the most seriously affected by fire damp. 

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 dioxid 

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 indistinguishable 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 u 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 Gtimbel,4 who subjected lignite to pressures 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

1 See G. Bischof, Edinburgh New Phil. 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.

2 Bull. Acad. Belgique, vol. 49,1880, p. 367.

3 Bull. Soc. ge"ol. France, 3d ser., vol. 12,1884, p. 680.

< Sitzungsb. Math.-phys. Classe, K.-bayer. Akad. Wiss., Munchen, vol. 13,1883,p. 141.

6 Annales chim. phys., 3d ser., vol. 32,1851, p. 304.
COAL. 727

cent of it remained as a solid residue which had all the appearance 

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 1 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 froiri ulmic acid, vasculose. .........................

C

66.84

68.48

78.78

76.06

78.78

H

4.78

4.68

5.00

4.99

5.31

o

28.43

26.84

16.22

18.95

18.26

 Compt. Rend., vol. 32,1851, p. 295. 2 Idem, vol. 88,1879, p. 1048.
728 THE DATA OF GEOCHEMISTRY.

The similarity of these products to natural coals, especially in the 

last three examples, is evident.

The most recent experiments of this order seem to be 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.

Temperature.

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 a 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, operi Chem. Centralbl., 1901, pt. 2, p. 950. From a Hungarian original which I have not seen.
COAL. 729

ating for a long time, may produce results resembling those which 

are brought about hurriedly in the laboratory.

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 phenomenon heat is generated by fermentation, 

and when actual inflammation is prevented for lack of air a partial 

carbonization may occur. In cases of this kind heat is generated 

locally and an imperfect combustion occurs. Hermann'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 time 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; it 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

' Zeitschr. angew. 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 ser., 

vol. 4,1905, pp. 851,1248, and vol. 6,1906, p. 273. Also in Compt. rend. VIII. Cong. gfiol. internat, 1900, 

p. 502. Lemiere regards the soluble or diastatic ferments, derived from living vegetation, as also operative 

in the process of vegetable decay.

s 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 Bertrand and Renault and 

by Jeffrey have already been referred to.
730 THE DATA OF GEOCHEMISTRY.

difficult to determine. Their structure, microscopic or macroscopic, 

tells a pretty clear story.

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 affected 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 bo dissolved by gasoline, ether, benzene, chloroform, alcohol, and other organic solvents. The extractive 

matter thus obtained is, unfortunately, not simple, but seems to contarn 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. Car- 

"bons of animal origin also require attention. Much preliminary work 

of this kind remains to be done.

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,

i On this subject see the authorities already cited. Also P. Siepmann, Preuss. Zeitschr. Berg-, Hiittenu. SalJnenwesen, vol. 39,1891, p. 27. F. Muck (Die Chemie der Steinkohle, Leipzig, 1891) gives a good summary of earlier investigations by Dondorff, Reinsch, etc. An interesting memoir by W. C. Anderson (Proc. 

Philos. Soc. Glasgow, vol. 29,1897, p. 72) also describes a number of important experiments.

* T. Baker, Trans. Inst. Min. Eng., vol. 20,1900, p. 159; and P. P. Bedson, Jour. Soc. Chem. Ind., vol. 27, 

1908, p. 147. See also E. Donath, Chem. Zeitung, vol. 32,1908, p. 1271.
COAL. 731

is also essential. Not only do we need more experiments along the 

Tine 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.

A Ber. Deutsch. chem. Gesell., vol. 5,1872, p. 185.

INDEX.

A. Page.

Aar, River, analysis of water................ 89

Abbot, C. G., and Fowle, F. E., carbon dioxide and climate................ 47,135

Abbot, H. L. See Humphreys and Abbott. 

Abert Lake, analysis of water............. 151,165

Ablch, H., analyses of spinel................ 324

Abilena well, analysis....................... 176

Abilene artesian well, analysis............... 171

Absorption, of substances by soils......... 477,478

Acanthite................................... 621

Acetylene................................. 684,691

Acetylene series........................... 684,685

Acheson, E. G., artificial graphite........... 310

d'Achiardi, A., origin of borates............. 234

d'Achiardi, G., minerals in marble........ 595,596

origin of borates......................... 234

Ackroyd, W., atmospheric transport of

salt ............................ 51,157

relative abundance of elements.......... 27

Acmite.................................... 360-362

Actinium .................................. 12,299

Actinolite................................... 364

Actinolite-magnetite schist.................. 583

Adamellose................................. 430

Adamite.................................... 641

Adams, B. F.,cited......................... 44

Adams, F. D., allanite and epidote.......... 387

alteration of pyroxene.................. 364

analyses by............................ 80,174

melilite rocks............................ 380

monmouthite........................... 423

primary calcite........................... 397

Adams, F. D., and Harrington, B. J., hastingsite.......................... 367

Adams, F. D., and Lawson, A. C., scapolite

diorite........................ 384,571

Adams, G. I., concentration of petroleum.... 704

gypsum................................. 220

native sulphur.......................... 550

salt deposits........................... 218,220

zinc deposits............................ 644

Adirondackiase............................. 444

Adler, River, analysis of water.............. 90

Adobe soil................................ 485,487

Adriatic Sea................................. 112

Adschl-Darja. See Karaboghaz.

Aegirite................................... 360-362

Aenigmatite................................. 368

Agate....................................... ' 339

Aguilarite................................... 622

Aguilera, J. G., stibnite..................... 658

Aichino, G., bauxite........................ 474

Aigner, A., polyhalite....................... 216

Page. 

Aikenite.................................... 630

Air, dissolved, composition of............... 453

See also Atmosphere. 

Aisinmann, , origin of petroleum........ 697

Aitken, J., atmospheric dust................ 51

Akermannite................................ 379

Akerose....................... 417,419,422,432,433

Alabama Elver, analysis of water........... 68

AlasMte..................................... 412

Alaskose.................................. 412,415

Albanose.................................... 424

Albert, R. See Malkomesius and Albert. 

Albertite.................................. 687-689

Albite..................................... 345-349

Albite mosaic............................... 568

Albrecht, R., optical activity of petroleum... 703 

Aldebaranium.............................. 21

Alexandrolite............................... 665

Alexejeff, W., dopplerite.................... 710

Alferric minerals............................ 404

Algae, as limestone makers............ 530,540,543

as source of bitumens.................. 700,701

magnesium carbonate in................ 543

Algodonite.................................. 628

Alipite...................................... 664

Alkali, in soils............................. 225-231

Allanite........................... 386,387,679,680

Allegheny River, analysis of water.......... 72

Allemontite............................... 656,657

Alien, E. T., aluminum hydroxide.......... 475

analyses by........................... 220,315

native iron.............................. 315

synthesis of quartz...................... 341

See also Day and Alien. 

Alien, E. T., and Clement, J. K., water in

amphilboles..................... 368

Alien, E. T., Johnston, J., and Crenshaw,

J. L., sulphides of iron........ 317,318

Alien, E. T., and White, W. P., fusion of lime

silicate.......................... 278

synthesis of diopside.................... 360

wollastonite........................... 359,594

Alien, E. T., Wright, F. E., and Clement,

J. K., magnesium silicate........ 278,

358,366,371

Alien, 0. D., analyses by.. 144,148,192,224,225,226 

Alloclasite................................... 660

Allopalladium............................... 668

Allophane................................. 395,584

Alma well, analysis cited.................... 174

Atmandite.................................. 380

Aloisi, P., spinel rocks...................... 326

Altai, Lake, analysis of water............. 159,163

saline deposit........................... 223

733
734 INDEX.

Page. 

Altalte...................................... 645

Altmuhl, River, analysis of water........... 92

Aluminum, distribution..................... 13

in sea water............................. Ill

Alum shale.................................. 521.

Alums.................................... 246,257

Alunite..................................... 247

Alunogen................................... 247

Alway F. J., and Gortner, R. A., water analysis .............................. 152

Amalgam................................. 615,619

Amazon River, analyses of water............ 83,98

Amber...................................... 707

Amblygonite................................ 655

Amesite..................................... 377

Ammiolite.................................. 634

Ammonia, in rainfall........................ 49

in sea water............................. 110

Amphiboles............................... 364-369

Amphibolite.......................... 566,571,573

Amsoldingen, Lac........................... 87

Analcite........................... 350-352,361,362

Analciterocks......................... 352,426,427

Anamorphism, zone of...................... 558

Anatase................................... 333-335

Andalusite........................ 389,390,584,585

Andalusite rocks............................ 587

Anderlini, F. See Nasini, R.

Anderson, , cited........................ 156

Anderson, W., cited....................... 150,189

Anderson, W. C., experiments on coal....... 730

Anderson, W. C., and Roberts, J., coal.... 615,618

Anderson, W. S., solubility of calcium carbonate .......................... 117

See also Irvine and Anderson. 

Andesine.................................... 346

Andesite.............................. 430-432,463

Andesner, H., fusion of gabbroid magma.... 401

Andorite.................................. 623,647

Andose.................... 428,432,433,434,438,439

Andouard, A., phosphate rock............ 497,498

Andradite................................... 381

Andree, K., fluorite in sediments............ 555

Andrew, A. R., gold in country rock........ 614

phosphate rock............... ......... 504

Andrews, E.G., magmatic assimilation...... 295

Andrews, T., native iron.................... 311

Androscoggin River, analysis of water....... r 66

Androussof, N., reduction of sulphates by

bacteria....................... 137,491

Anemousite................................. 346

Anger, F. A., shale....;..................... 524

Angemsee, analysis of water................. 95

Anglesite.............................. 646,648,649

Angstrom, K. J., carbon dioxide and climate. 47 

Annecy, Lake of, analysis of water.......... 86

Anhydrite......... 211,212,215,216,217,218,235,243

Animikite................................... 621

Ankerite.................. . ................. 545

Annabergite................................. 663

Anorthite............................. 345-349,595

Anorthoclase................................ 345

Anorthosite................................. 439

Ansdell, G. See Dewar and Ansdell.

Ansel, H., iron ores......................... 549

Anthon, E. F., precipitation of sulphides.... 612

Page. 

Anthophyllite............................... 364

Anthracite................................ 718-721

Anthraxolite................................ 720

Antimony, distribution..................... 14

ores of................................. 656-659

Ants, geological work of..................... 461

d'Aoust, V., oolite........................... 525

Apatite............................... 336-338,495

Aphrosiderite............................... 377

Aphthitalite................................ 212

Aplite....................................... 412

Apjohn, J., water of the Dead Sea............ 157

Apophyllite............................... 309,395

Aragonite............................. 396,527-534

Aral, Sea of, analysis of water............. 154,164

Arctic Ocean, analyses of water.............. 113

Arctowski, H., synthesis of hematite........ 329

Ardennite................................... 674

Arfvedsonite................................ 368

Argall, P., distribution of nickel............. 660

Argentite................................... 621

Argon, distribution...................... 14,40,683

in spring waters......................... 169

Argyrodite.................................. 623

Arias, Rio de, analysis of water.............. 84

Arkansas Hot Springs, analysis of water..... 184

Arkansas River, analysis of water........... 62,76

flow of.................................. 76

Arkansose................................... 424

Arkite...................................... 424

Arnold, R., and Anderson, R., alteration of

shale............................ 582

Aromatic hydrocarbons..................... 685

Arrhenius, S. A., carbon dioxide and climate. 46 

nature of earth's interior................. 55

volcanic explosions.................... 271,272

Arsandaux, H., analysis by................. 498

bauxite................................. 472

laterite.................................. 470

Arsenic, distribution........................ 14

in sea water............................. 110

ores of................................. 656-659

Arsenolite................................... 659

Arsenopyrite.......................... 603,656,659

Arva-Polhora, analysis of water............. 173

Arve River, analysis of water................ 86

Arzruni, A., cassiterite as a furnace product. 335,652 

1 cuprite.................................. 632

hematite................................ 329

Asbestos.................................... 364

Asbolite............................... 509,663,664

Aschan, 0., humus in natural waters........ 98

iron ores................................. 507

waters of Finland........................ 95

Ascharite.................................. 214,238

Ashburner, C. A., anthracite................ 719

classification of coals..................... 722

Ashley, G. H., antimony deposits........... 658

formation of peat...................... 708-711

See also Blatchley and Ashley. 

Ashley, J. M., cited.......................... 85

Askwith, W. R., antimony mines........... 659

Aspasiolite.................................. 386

Asphalt................................... 686-689

Assiniboine River, analysis of water......... 80

Aston, E., analysis by....................... 579
INDEX. 735

Page. 

Astrakanlte................................. 212

Atacamite................................... 632

Atherton, T. W. T., gold sulphide............ 614

Atlantic Ocean, analyses of water............ 112

Atlin, spring near, analysis.................. 180

Atmosphere, composition of................. 40-46

mass of.................................. 22,52

the primitive............................ 52-55

Atomic weights.............................. 13

Atopite...................................... 659

Atrek River, analysis of water............... 154

Atterberg, A., alteration of topaz............ 388

laterite.................................. 470

Attwood, G., decomposition of diabase...... 464

Aubin, E., cited............................. 41

Audoynaud, A., ammonia in sea water....... 110

Auerbach, F., cited.......................... 191

Auerbach, H. S., tungsten deposits.......... 668

Aug6, , bauxite........................ 472,473

Augite..................................... 362-364

Augite, melting point........................ 279

Austin, W. L., nickel ores................... 663

Autunite.................................... 674

Auvergnose........................ 433,434,438,439

Avalite...................................... 665

Awaruite.................................. 314,660

Awerkiew, N., solubility of gold............. 618

Azurite...................................... 633

B. 

Babingtonite................................ 363

Babitsee, analysis of water................... 95

Backstrb'm, H., fusion of micas............ 376,425

on Soret's principle...................... 294

synthesis of acmite...................... 361

Bacon, R. F., analyses cited................. 189

Bacteria as agents in rock decomposition.. 460,461 

Bad Elster, analysis of water from............ 182

Baddeckite.................................. 372

Baddeleyite................................. 678

Baer, W., analyses of wood.................. 706

Baerwald, C., pseudomorphs of chrysocolla.. 632 

Baeumler, , nickel in shale............... 660

Baikal, Lake, analysis of water.............. 95

Bailey, E. H. S., analyses by.............. 176,683

Bailey, E. H. S., and Case, E.-C., analyses

by............................. 171,219

Bailey, E. H. S., and Franklin, E. C., water

analyses......................... 74

Bailey, E. H. S., and Porter, F. B., analysis

by............................... 171

Bailey, G. E., California borates............. 234

soda niter............................. 241,242

Bain, H. F., fluorite......................... 556

lead and zinc deposits................... 644

Baker, A. L., bromine in bittern.. .......... 221

synthesis of livingstonite................ 636

Baker, H. B., cited....:..................... 48

Baker, T., extracts from coal............... 730

Bakerite..................................... 236

Balatonsee, analysis of water................ 94

Balch, D. M., potassium chloride in algse.... 128

Baldacci, L., sulphur deposits............... 552

Baldauf, R., cryolite......................... 319

Balland, , cited.......................... 62

Ballo, M., water analysis.................... 92

Page. 

Ballston waters, analyses.................... 175

Baltic sea, analysis of water................. 112

Baltimoriase................................. 441

Baltimorose................................. 441

Bamberger, E., fichtelite.................... 711

Bancroft, G. J., origin of ore bodies.......... 611

Bancroft, H., platinum in dikes............. 670

Bandose................................... 430,438

Bandrowsky, F. X., nitrogen in petroleum.. 686 

' Baragwanath, W., platinum................. 672

Barber, W. B. See Nutter and Barber. 

Barbier, P., and Prost, A., composition of

feldspars........................ 345

Barbierite................................... 345

Barbour, E. H., and Torrey, J., siliceous

oolite............................ 520

Barcenite..................................634,658

Barchatow bitter lake, analysis of.water... 160,164

Baret, C. See Lacroix and Baret.

Barite......................... .124,514,515,553-555

Barium, distribution................... 14,653-555

in sea water............................. 110

in soils.................................I 14

Barkevikite................................. 368

Barlow, A. E., nickel deposits............. 661,663

Barnard, H. E., analysis of water............ 66

Barnes, H. T. See Rutherford and Barnes. 

Barnitzke, J. E., kaolinization............... 468

Barr, W. M., analyses by..... 70,71,72,73,74,76,77

Cove Creek acid water................... 190

Barrandite................................ 496,498

Barrell, J., magmattc assimilation........... 295

Barrois, C., chloritoid rocks................. 586

Barschall, H. See Van't Hoff and Barschall. 

Bartow, E., waters of Illinois................ 59

Barus, C., sedimentation.................... 482

thermo-couple........................... 277

water glass........................ 283,560,610

Barus, C., and Iddings, J. P., electric conductivity of molten rocks........ 285

Barysilite................................... 651

Basalt.......................... 426,434,435,436,437

fusibility.............................. 282,285

Basanite.................................... 422

Basch, E. E., syngenite and polyhalite...... 215

Basic rocks................................ 443,444

Baskerville, C., analyses by............... 326,665

thorium................................. 679

vanadium in peat....................... 673

See also Corse and Baakerville. 

Bassett, H., cited........................... 143

Bassler, R. S., siliciflcation of fossils......... 534

Bastin, E. S., diagnostic criteria of metamorphicrocks................. 597,598

origin of graphite........................ 311

pegmatite............................. 289,412

pyrrhotitic peridotite.................. 317,443

Bastite...................................... 358

Baubigny, H., synthesis of sphalerite........ 639

Bauer, H., and Vogel, H., cited............. 88

Bauer, K., fusion of mineral mixtures....... 291

Bauer,M.,laterite........................ 470,471

nephelite in schists...................... 354

Bauerman, H., and Foster, C. Le Neve,

celestite......................... 553

Baumann, A., and Gully, E., humus acids.. 460
736 INDEX.

Page.

Baumert, M., composition of dissolved air.. 48,453 

Baur,E., synthesis of quartz and trldymlte. 340,348 

Bauxite................................... 469-477

Bayldonlte.................................. 651

Bayley, W. S., actlnollte-magnetite schist... 365 

graywacke.............................. 516

Iron ores.............................. 329,546

talcose schist............................ 595

Beam, W., water analyses................... 97

Bear River, analysis of water................ 145

Beaumont,E.de,distributionoftheelements. 13 

volcanic emanations..................... 249

Beauvallet, P., vanadium in clay........... 673

Bfichamp, A., equilibrium in mineral waters. 191

hydrogen sulphide and calcium carbonate. 551

Bechi, E., origin of borates.................. 233

distribution of vanadium................ 673

Bechilite.................................... 232

Beck, R., cassiterite in granite............... 335

diamond................................ 308

gases from obsidian...................... 270

magnetite............................... 328

native copper........................... 627

native silver............................. 620

nickel deposits.......................... .662

ore deposits........................... 549,599

primary gold............................ 316

tin ores.................................. 654

Beck, R., and Fircks, W. von, copper ores.. 629 

stibnite................................. 658

Becke, F.,amphibolite...................... 566

changes of volume in metamorphism.... 562

eologite.................................. 573

graphic symbols......................... 451

hornblende pseudomorphs............ 366,371

saussurite gabbro......................... 569

scapolite rock........................... 571

See ako Step and Becke. 

Becker, A., fusion of hornblende............ 366

fusion of limestone...................... 532

Becker, G. F., age of minerals......... 302,303,304

age of ocean........................... 137,141

arsenic and antimony in sinter........ 657,658

borates...................:............. 231,232

Borax Lake............................. 150

constitution of amphiboles and pyroxenes 367 

epidote from chlorite.................... 571

eutectic classification of rocks............ 401

fractional crystallization in magmas...... 296

formation of native sulphur.............. 550

geological significance of wollastonite..... 359

glaucophane rocks..................... 369,565

gold in suiter............................ 617

heavy metals in granite.................... 601

magmatic differentiation................ 294

mercury ores...................... 634,636,637

minerals in sandstone.................... 516

nature of magmatic solutions............ 284

oceanic chlorine......................... 129

origin of petroleum...................... 695

pore space in sandstone.................. 514

radioactivity............................ 303

serpentine......................... 394,576,577

solvent of gold.......................... 617

Steamboat Springs........ 195,601,617,638,658

waters of Sulphur Bank................. 186

Page. 

Becker, G. F., and Melville, W. H., mercury

in sinter......................... 637

Becquerel, A. C., synthesis of dioptase........ 633

syntheses of lead ores.......... 646,647,648,650

Becquerel, H., and Moissan, H., free fluorine

in fluorite....................... 319

Bedson, P. P., barium in water............. 553

constitution of coal...................... 730

gases In coal............................. 725

Beegerite.................................... 647

Beemerose................................... 422

Beerbachose..........................:.... 433,438

Beilstein, F., and Wiegand, E., ozokerite..... 686

Beisk, Lake, analyses of water............. 159.163

saline deposits........................... 222

Beistle, C. P. See Frear and Beistle.

Belcherose .................................. 441

Beldongrite............... I..........'....... 510

Bell, J. B., platiniferous quartz.............. 671

Bell, J. M. See Cameron and Bell.

Bell, J. M., and Clarke, E. de C., mercury in

sinter............................ 638

Bell, R., corrosion of limestone.............. 534

nickel deposits.......................... 661

Bellucci, G., chlorides in rain................ 50

Bfilohoubek, A., water analysis.............. 90

Bemmelen, J. M. van, absorbent power of

hydrogels........................ 478

absorption of potassium by clays......... 127

aluminum hydroxides................... 475

decomposition of rocks.................. 468

hydroxides of iron................'. 504,506,507

laterite.................................. 470

tropical soils............................. 475

zeolitic silicates in soil................... 200

Bemmelen, J. M. van, Hoitsema, C., and

Klobbie, E. A., bog iron ore.... 505,507

Bemmelen, J. M. van, and Klobbie, E. A.,

iron hydroxides................. 507

Benedicks, C., sericitic rocks................. 567

Bennett, J. See Haworth and Bennett.

Benzene series............................... 685

Beraunite................................... 496

Beresovite................................... 650

Berg, L., Sea of Aral........................ 154

Bergeat, A., boric acid from Vulcano........ 232

nontronite.............................. 468

occurrence of titanium minerals......... 334

ore deposits............................. 599

volcanic sublimates...................... 257

Bergenose................................... 444

Berglund, E., bromine in sea water.......... 112

Bergstrasser, , cited..................... 155

Bergt, , analysis by...................... 520

Bertels, G. A., origin of petroleum..........; 698

Berthelot, M., gases in native iron........... 274

origin of petroleum...................... 694

synthetic hydrocarbons................ 691,692

Berthier, ,-synthesis of olivine........... 370

Berthierine.................................. 549

Berthierite.................................. 656

Bertrand, C. E., and Renault, B., origin of

bitumen......................... 700

Bertrandite................................. 393

Berwerth, F., constitution of hornblende.... 367

Beryl.................................-...!.. 393
INDEX. 737

Page. 

Beryl, gases from ............................ 262

Beryllium. See Glucinum.

Beryllonite.................................. 393

Berzelianite................................. 628

Berzelium................................... 679

Best, A. See Coates and Best.

Beudantite.........'......................... 651

Beyer, S. W., clays.......................... 484

Beyerinck, M. W., cited..................... 102

Beyrichito................................... 660

Beyschlag, F., cobalt ores................... 660

See also Monke and Beyschlag. 

Beyschlag, Krusch, and Vogt, ore deposits .. 599 

Bickell, C., analysis by...................... 196

Biddle, H. C., precipitation of copper......... 627

Biddle, H. J., nickel ores.................... 663

Bioberite.................................... 663

Biggs, J. W. H. Sec Clowes, F.

Bigstone Lake, analysis of water............. 71

Biljo Lake, analysis of water.............. 159,165

Biltz, W., and Marcus, E., copper in Stassfurt salts........................ 211

nitrates and ammonia in Stassfurt salts... 212 

See also Marcus and Biltz. 

Binder, G. A., solubility of cinnabar......... 638

of sulphides............................. 603

Bindheimite................................. 651

Binnoy, E. W., and Talbot, J. H., petroleum

in peat.......................... 701

Biotite.................................... 372-376

Biquard, R. See Moureu, C.

Bird, M., analysis by........................ 171

Bischof, G., analyses by............. 92,94,161,481

cements in sandstone.................... 515

dolomitization........................... 541

gases in coal............................. 726

origin of salt beds........................ 209

reduction of silver sulphide.............. 620

solvents of gold.......................... 617

sphalerite in sinter...................... 640

zinc carbonate........................... 642

Bischofite................................... 213

Bismite..................................... 659

Bismuth, distribution....................... 14

ores of................................. 050-659

Bismuthinite.............................. 657,667

Bismutite................................... 659

Bismutosmaltite............................. 660

Bismutosphffirite............................ C59

Bistineau; brine, analysis of................. 17i

Bitter Lake, analysis of water.............. 159,163

Bitterns............................... 208,220,221

Bitumen.................................. G8C-689

Bituminous coal..............:........ 716-718,721

Bizio, G., lithium in sea water............... 110

Black Lake (California), analysis of water.. 150,164 

Black Lake (Roumania)....'................. 161

Black Sea, analysis of water................. 113

Blackwell, G. G., bauxite................... 473

Blake, J. F., glaucophane schist............. 565

Blake, R. F., cited.......................... 44

Blake, W. P., bauxite....................... 473

gilsonito and wurtzilite.................. 087

primary gold............................ 613

Terlingua mines......................... 634

tin deposits............................ 652,656

101381° Bull. 491-

Page. 

Blake, W.P.,tungsten ores.................. 668

zinc deposits...................... 634,644,045

Blanc, G. A., radioactivity.................. 300

radiothorium............................ 300

Blanckenhorn, M. See Semper and Blanckenhorn. 

Blatchley, W. S., clays...................... 484

petroleum............................... 702

Blatchley, W. S., and Ashley, G. H.; marl,. 526 

Bleeck, A. W. G., jadeite.................... 361

Bleicher, , iron ores...................... 549

Blende........................ 603,639-641,643,644

Bloedite................................... 212,243

Blue Lick Spring, analysis.................. 172

Blue River, analysis of water................ 75

Blum, W., Great Salt Lake.................. 144

Blum and Leddin, Carlsbad spriidelstein.... 193

Bobierre, composition of rainfall............. 51

Bobierrite................................... 496

Bode, G., cited.............................. 64

Bodenbender, G., wolframite................ 668

Bodlander, G., analysis by.................. 547

melilite in Portland cement.............. 379

sedimentation........................... 482

Bodtker, clay............................... 491

Boeke, H. E., borates in potash salts........ 238

bromine in potashsalts.............i.... 211

carnallite ahd tachhydrite .............. 213

graphic representation of Stassfurt salts.. 213 

iron in potash salts...................... 214

rinneite................................. 214

sintering of calcium carbonate........... 532

Bottcher, W. See Kramer and Bottcher. 

Boettker, E., Norwegian pyrite............. 318

Boghead mineral............................ -700

Bog-iron ore....................... 505-508,545,710

Boleite...................................... 649

Bolley, P., origin of borates................ : 233

Bolton, H. C., solubility of minerals in organic acids...................... 460

Bolton, W.von,tantalum ................... 678

Boltonite.................................... 371

Boltwood, B. B., age of minerals............ 303

radioactivity of hot springs.............. 204

Bone, W. A., and Coward, H. F., union of carbon and hydrogen............... 692

Bone, W. A., and Jerdan, D. S., synthetic

hydrocarbons................... 692

Bonneville, Lake............................ 143

Bonney, G. T., glaucophane eclogite......... 565

matrix of diamond.................... 308,309

serpentine............................... 575

Bonyssy, see Henriet and Bonyssy.

Booth, J. C., and Muckle, A., Dead Sea..... 157

Boracite................................... 214,238

Borates............................... 214,231-240

Borax..................................... 231-240

Bcrax Lake, analysis of water............. 150,165

borax from.............................. 231

Bordas, F. See Girarcl, C.

Borgstrom, L. H., hackmannite............. 355

Boric acid....:........................ 232-233,257

Borickite.................................... 496

Borne, G. von dem, radioactivity of granite.. 301 

Bornite........................... 318,628,629,630

Borntrager, H., analyses of peat............. 710
738 INDEX.

Page. 

Borocalcite......."........................... 232

Borodowsky, W., orpiment and realgar...... 657

Boron, distribution.......................... 14

in sea water............................. 110

nitride.................................. 233

sulphide................................. 233

Boronatrocalcite............................. 236

Bothamley, C. H., analysis by.............. 173

Boudonard, 0., melting point of silica..... 265,279

Boulangerite................................ 647

Bouquet, J., analyses by.................. 180,194

spring deposits........................ 193,194

Bouquet de la Grye, A., cited............... 114

Bourcart, E., Swiss lakes..................... 87

Bourgeois, L., cassiterite in scoria........... 652

formation of perofskite................... 332

fusion of garnet.......................... 381

synthesis of crocoite..................... 650

of hydrocerusite..................... 648

of iolite.............................. 385

of meionite.......................... 383

of melilite and gehlenite........... 379,380

of smithsonite....................... 642

of spessartite........................ 381

of titanite........................... 332

of wollastonite...................... 359

Bourgeois, L., and Traube, H., synthesis of

dolomite......................... 537

Bourgoin and Chastaing, analysis by........ 186

Bournonite................................ 603,630

Boussingault, J. B., analyses by........... 188,221

carbon dioxide from volcanoes........... 45

Dead Sea................................ 156

jet....................................... 712

manganese nodules...................... 121

nitrate earth............................ 241

origin of acid in volcanic waters......... 189

Boussingaultite............................. 232

Boutan, E., diamond........................ 310

Boutron-Charlard, A. F., and Henry, O.,

Dead Sea........................ 157

Boutwell, J. M., carnotite................. 676,677

Bownocker, J. A., petroleum................ 702

Bow River, analysis of water................ 81

Brackebuschite.............................. 651

Brackett, R. N., analyses by........... 76,463,520

Brackett, R. N., and Williams, J. F., rectorite......... .................. 584

Braconnier, , analysis by................ 176

Bradley, F. H., unakite..................... 572

Bradley, W. M. See Foote and Bradley. 

Braunlich, F. See Donath and Braunlich, 

Bragard. See Fernandez and Bragard. 

Brand, A., artificial breithauptite........... 661

Brandenbourg, R., water analysis........... 86

Branner, J. C., antimony deposits........... 654

bacterial decomposition of rocks......... 461

bauxite................................. 474

clays.................................... 484

diamonds............................... 309

flow of Arkansas River.....:.......-..... 76

geological work of ants.................. 461

magnesia in coral reef.................... 542

novaculite............................... 518

phosphorite............................. 502

sandstone reefs.,..,.,,.,,,,,,.,,........ 514

Page. 

Branner, J. C., tallow clays.................. 644

thermal disintegration of rocks.......... 452

zinc deposits............................ 644

Branner, J. C., and Newsom, J. F., phosphorite............................... 502

Bransky, O. E. See Gilpin and Bransky. 

Brauner, B., gold telluride.................. 616

synthesis of hessite...................... 622

Braunite.................................... 509

Brauns, R., alteration of olivine............. 372

conchite................................. 527

gold in a cement......................... 617

graphite and molybdenite in basalt...... 318

origin of salite........................... 360

theory of micas.......................... 377

webskyite............................... 394

Bravo, J. J., vanadium ores................. 674

Brazier, J. S., analyses by................... 489

Brazos River, analyses of water............. 77

Breckenridge, L. P., classification of coals... 723 

Breese, C. M. See Failyer and Breese. 

Breitenlohner, J. J., on the Elbe............. 90

Breithauptite............................... 660

Breunnerite............................... 397,545

Brewer, W. H., sedimentation.............. 482

Brewsterite................................. 395

Briegleb, H., synthesis of apatite............ 337

Brinsmade, R. B., cerusite deposit.......... 648

Brochantite............................... 632,633

Brock, R. W., gold in igneous rocks....... 316,613

platinum................................ 672

Brodie, B.C., graphitic acid................. 720

synthesis of methane.................... 266

Brogger,W. C., alteration of acmite to analcite 361 

alteration of analcite.................... 352

of arfvedsonite and barkevikite...... 369

of elseolite........................... 354

classification of igneous rocks............ 404

composition of barkevikite.............. 368

formula of senigmatite................... 368

gibbsite and diaspore.................... 474

magmatic differentiation.............. 284,293

nephelinesyenites....................... 423

nordenskioldine......................... 652

occurrences of fluorite................... 318

of zircon............................. 336

spreustein............................... 357

sulphides in pegmatite.................. 318

Brogger, W. C., and Backstrom, H., the garnet group..................... 355,381

Broggerite............................ 1...... 675

Brokaw, A. D., solubility of gold............ 618

Bromine, distribution....................... 14

in bittern................................ 208

Bromly, A. H., tin deposits................. 654

Bromyrite.................................. 625

Brongniardite............................. 623,647

Bronze, minerals formed on........... 627,629,632

Bronzite.................................... 357

BrooMte.................................. 333-335

Brooks, A. H., tin deposits.................. 655

Brooks, W. K., abundance of life in ocean..... 136

Brown, A. P., pyrite and marcasite......... 318

Brown, B. E., water analyses.............. 78,146

Brown, C. R. See Judd and Brown. 

Brown, L. See Meadows and Brown.
INDEX. 739

Page. 

Brown, L. P., phosphorite.................. 501

Browne, D. H., nickel deposits.............. 661

Bruclte................................... 539,577

Bruguatelli, L., titanolivine................. 370

Bruhns, W., synthesis of corundum......... 320

synthesis of hematite.................... 330

of ilmenite.......................... 330

of quartz and tridymite............. 340

Brumell, H. P. H., petroleum............... 702

Brun, A., deposition of sulphur............. 257

fusibility of basalt....................... 282

melting points of minerals............. 278,280

origin of petroleum...................... 694

synthesis of corundum.................. 320

of hydrocarbons..................... 691

of quartz and tridymite.............. 341

of zoisite ............................ . 386

volcanic gases......................... 268-271

volcanic hydrocarbons .................. 694

volcanism............................. 268-271

Brun, A., and Collet, L. W., volcanism...... 268

Brunlechner, A., formation of iron ores...... 547

Brunswick well, analysis ..................... 172

Brush, G. J., pyroxene in slag............... 360

Brush, G. J., and Dana, E. S., alteration of

spodumene...................... 361

eucryptite......................... 353,354,361

Brushite.................................. 496,497

Buchanan, D. G., analysis by............. 242,243

Buchanan, J., section of nitrate deposit...... 242

Buchanan. J. Y., density of sea water....... 114

manganese nodules...................... 121

marine rnud............................. 491

oceanic carbonic acid.................... 133

Buchner, E. H., radioactivity of rocks....... 300

Buchrucker, L., babingtoiiite in slags....... 363

Bucking, H., occurrence of iolite............ 385

Buckley, E. Jt.,c\&ys....................... 484

Buckley, E. 11., and Buehler, H. A., zinc deposits. .......................... 644

Buehler, H. A., and Gottschalk, V., analyses

of mine waters.................. 604

Buehler, H. A. See also Buckley and

Buehler. 

Bujor, P., cited............................. 161

Biiluktu-Kul, analysis of water............ 160,164

Bunsen, E. W., composition of dissolved air. 48,

130,453 

fundamental magmas................... 293

gases in rock salt........................ 261

magmatic solutions..................... 294

oxygen of the atmosphere............... 41

volcanic gases........................... 249

Bunsenite................................... 663

Burada, A., the Black Sea.................. 112

Burchard, E. F., lignite..................... 714

Burgess, G. K. See Waidner and Burgess. 

Burgess, J. A., halide ores of silver.......... 625

Burton, C. V., artificial diamond............ 308

Buschmann, J. 0., von, Das Salz............ 218

Bush, E. R., nickel deposits................. 662

Bushong, F. W., petroleum................. 685

Busz, K., analysis by....................... 471

corundum............................... 321

Butler, B. S., epidote....................... 387

Butler, F. H., kaolinization................. 468

Page. 

Buttgenbach, G., Argentine borates......... 237

Byasson, H., origin of petroleum............ 694

Byerlite..................................... 689

Byerly, J. H. See Mabery and Byerly.

Bygd6n, A., eutectics...................... 288,402

Byske-elf, analysis of water.................. 94

Bytownite.................................. 346

C.

Caballero, G. de J., cobalt in Mexico......... 660

ramirite................................. 674

Cabrerite.................................... 663

Cache la Poudre River, analyses of water.... 61

Cacoxenite.................................. 496

Cadell, H. M., cited on Stassfurt salts........ 210

Cadmium, distribution...................... 14

ores of................................. 638-640

Cady, H. P., and McFarland, D. F., composition of natural gas............. 683

Caesium, distribution........................ 15

in sea water............................. 110

Cagniard-Latour, artiflcal coal............... 727

Cahaba River, analysis of water............. 68

Cailletet, L., hydrogen in iron............... 273

Calamine.............................. 641,643-645

Calaverite................................... 616

Calb, G. See Jannasch and Calb.

Calcareous sinter.............. 192,193,524,525,526

Calcioferrite................................. 496

Calciovolborthite.......................... 674,677

Calcite........................ 235,396,397,524-534

inclosing sand........................... 513

Calcium, distribution........................ 15

Calcium carbonate, circulation of............ 119

proportions on ocean floor......L........ 120

solubility of........................... 117-119

Calculation of rock analyses............... 448-451

Calderon, C. S., Chaves, D. F., and Pulgar,

P. del, glauconite............... 492

Caledonite................................... 649

Caliche.................................... 242-243

California geysers............................ 189

Californite................................... 383

Calker, F. J. P. van, pseudogaylusslte...... i 148

Callainite.................................... 496

Calomel..................................... 634

Cameron, F. K., alkali in soils............... 231

water analyses.......................... 78,145

Cameron, F. K., and Bell, J. M., solubilities. ........................... 218,454

Cameron, F. K., and Hurst, L. F., solubility

of calcium phosphate............ 495

Cameron, F. K., and McCaughey, W. J.,synthesis of apatite. ................ 337

Cameron, F. K., and Seidell, A., solubility of

calcium phosphate.............. 495

Campbell, H. D. See Howe, J. L.

Campbell, J. M., laterite..................... 470

Campbell, M. R., borate deposits.......... 234,236

classification of coals..................... 723

Campbell, N. R., radioactivity............ 300,302

Campbell, N. R., and Wood, A., radioactivity........................... 302

Campbell, W., and Knight, G.W., cobalt ores. 663

nickel deposits.......................... 662
740 INDEX.

Page. 

Campbell, W. D., pseudomorph of gold...... 618

Camptonite.................................. 433

Camptonose....................... 433,434,438,439

Canadase.................................... 439

Cancrinite................................. 355-357

Cancrinite syenite........................... 357

Canfleldite................................... 623

Cannel coaL........................... 717,718,724

Cape Fear River, analysis of water .......... 68

Caracolite................................... 649

Carbides,metallic..................... 267,691,694

Carbon, distribution......................... 15

Carbon dioxide in the atmosphere........... 42-46

Carbonates in sea water.................... 117-119

Carbonates, alkaline....................... 225-231

origin of................................. 199

Carbonic acid, oceanic..................... 132-135

Carbonyls, metallic.......................... 313

Carborundum............................... 310

Carles, P., barium and sulphates in natural

water............................ 193

fluorine in shells of mollusks............. 109

in spring water...................... 180

Carlsbad Sprudel water, analysis............ 182

Carminite................................... 651

CarnaUite.................................. 213,214

Carnegieite.................................. 346

Carnelley, T., on periodic law................ 36

solubility of copper...................... 626

Carnot, A., fluorine in phosphates............ 500

fluorine in sea water..................... 109

galena................................... 645

minervite.............................. 497,498

phosphate rock........................ 495,499

syntheses of stibnite and bismuthinite..................................... 657

water analysis......................... 161,186

Carnotite.................................. 676,677

Carolinium.................................. 679

Caron, H. See Deville and Caron.

Carpenter, W. L., oceanic carbonic acid.... 136,530

CarroUite.................................. 628,660

Carstone..................................... 517

Caryinite.................................... 651

Casares, J., fluorine in spring water.......... 180

Case, E. C. See Bailey and Case.

Case, W. H., zinc deposits................... 644

Casoria, E., palmerite....................... 498

volcanic sublimates...................... 257

Caspari, W. A.,glauconite................... 493

red clay................................. 489

Caspian Sea........................... 153-155,164

Cassel brown................................ 715

Casseliase.................................... 442

Casselose...................:................ 436

Cassiopeium................................. 21

Cassiterite............................. 335,652-656

Castorina, G. T., radioactivity of lava....... 300

Catapleiite................................... 678

Catharinet, J., copper ores................. 629,630

gold in pegmatite........................ 613

sperrylite in pegmatite.................. 672

Cathrein, A., alterations of garnet.......... 382,383

chloritoid rock........................... 586

epidotization............................ 571

leucoxene................................ 331

Cathrein, A., occurrence of chloritoid........ 376

pseudomorphs after gehlenite............ ' 380

after scapolite....................... 385

saussurite............................... 569

titaniferous magnetite................... 331

Catlett, C., analyses by.............:...... 533,615

See also Clarke and Catlett. 

Cayeux, L., chalk........................... 528

gaize................................:... 518

glauconite............................. 492,494

glauconitic iron ore...................... 506

oolitic iron ores.......................... 549

phosphatic nodules...................... 123

soils..................................... 484

Cecilose...................................... 441

Cedar River, Iowa, analysis of water......... 72

Ced ar River, Wash., analysis of water....... 78

Cedarstrom, A., cited........................ 331

Celadonite................................. 493,494

Celestite........................... 212,235,552,553

Cellulose............................... 705,706,721

Celsian...................................... 346

Celtium..................................... 13 '

Cementation, belt of......................... 558

Cements in sandstone...................... 513-516

Centeno, J., analyses by..................... 189

Cerargyrite................................... 625

Cerite....................................... 679

Cerium, distribution......................... 15

sources of................................ 679

Cerusite................................... 648,649

Cervantite.................................... 659

Chabazite................................... 395

Chabri6, , Algerian saltpeter........... 241

Chalcanthite................................. 632

Chalcedony................................ 339,519

Chalcocite................................. 628-630

Chalcophanite............................... 641

Chalcophyllite............................... 632'

Chalcopyri'te....................... 318,603,628-630

Chalcostibite................................ 630

Chalk...................................... 524,528

Chalmers, R.,peat.......................... 711

Chalmersite................................. 628

Chamberlin, R. T., gases from rocks....... 268,272

Chamberlin, T. C., influence of oceanic carbonates on climate............... 134

loess..................................... 486

planetesimal hypothesis................ 55,129

zinc ores................................. 644

Chamberlin, T.C., and Salisbury, R. D., clays. 483 

volcanism............................... 272

volume of ground water................. 33

Chamosite................................. 377,549

Champex, Lac............................... 87

Champlain, Lake, analysis of water.......... 65

Champlainiase............................... 444

Chance, H. M., origin of iron ores............ 505

Chancourtois, E. de, metals in earth's interior. 313 

water analysis........................... 158

Chandelon, J. T. P., cited................... 86

Chandler, C. F., analyses by............. 65,66,175

Chaper, M., diamonds in pegmatite.......... 309

Chaplin Lake................................. 152

Charante, G. M. van, analysis of water....... 505

Charcoal................................... 726,727
INDEX.

Page. 

Charcoal, fossil.............................. 712

Charitschkoff, K., synthetic hydrocarbons... 691 

waters accompanying naphtha.......... 699

Charlton, A. G., nickel ores.................. 660

Charlton, H. W., analysis by................ 426

Chastaing, . See Bourgoin and Chastaing. 

Chatard, T. M., analyses by................. 60,

145,148,150,151,225,226,228,362.

441, 442,517, 522,533, 547,588, 665

natural soda....................... 150,227-228

origin of corundum...................... 322

tallow clay.............................. 644

Chateau, , Algerian phosphates.......... 501

Chattahoochee River, analysis of water...... 68

Chautard, J., lateritization.................. 470

Chautard, J., and Lemoine, P., lateritization. 470

Chaves, D. F. See Calderon, C. S., etc.

Chazal, P. E., phosphate rock............... 501

Che'lif, River, analyses of water.............. 63

Cheltenham waters, analysis............... 175,176

Ch61u, A., sediment of the Nile.............. 482

water of the Nile....................... 96,105

Chemical denudation...................... 102-108

Chenevixite.......'.......................... 632

Cherrydale mineral water.................... 186

Chert.......................... 518-521,548,549,582

Chester, A. It., on waters of New Jersey..... 66

Chester, F. D., epidotization................ 572

Chevallier, A., cited......................... 114

Chevandier, E., analyses of wood............ 706

Chiastolite schist............................ 587

Chicago drainage canal..................... 99,100

Chichen-Kanab, Lake, analysis of water... 153,164 

Chiemsee, analysis of water.................. 88

Chilenite.................................... 621

China Sea, analysis of water................. 113

Chippewa River, analysis of water........... 71

Chiviatite................................... 647

Chloanthite................................. 660

Chlorides in rainfall......................... 50

Chlorine, distribution....................... 15

in atmosphere........................... 50

in potable waters........................ . 50

in sea water, origin of.................. 128-130

in volcanic gases....................... 269,270

Chlorites.................................. 377,378

Chloritization............................. 573,574

Chloritoid............................. 373,585,586

Chloritoid-phyllite.......................... 587

Chlormanganokalite......................... 258

Chlorophyllite.............................. 385

Chloropite.................................. 574

Chlorothionite.............................. 258

Chlorspodiosite.............................. 337

Cholesterin.................................. 702

Chondrodite................................ 576

Chotose..................................... 424

Christie, W. A. K. See Holland and Christie. 

Christy, S. B., synthesis of cinnabar......... 635

Chromic iron ore. See Chromite.

Chromite...................... 324,326,327,665,666

Chromitite.................................. 326

Chromium, distribution..................... 15

ores of................................. 664-666

Chrompicotite............................... 326

Page. 

Chrustschoff, K., artificial diamond......... 307

synthesis of hornblende................. 366

of mica.............................. 374

of quartz and feldspar............... 348

of quartz and tridy mite........... 340,341

of zircon............................ 336

Chrysocolla................................. 633

Chrysolite................................... 370

Chuard, E., alteration of bronze............. 629

Church, A. H., siliciflcation of coral....... 491,519

Cimolite.................................. 395,584

Cincinnati artesian well, analysis............ 172

Cinnabar.............................. 634,635,658

Ciplyte...................................... 499

City Creek, analysis of water................ 145

Claesson, C., dopplerite..................... 710

Clapp, F. G., limestones.................... 533

Claraz, G. See Heusser and Claraz.

Clark, A. H., crmoids....................... 540

Clark, G.F.,cited..............\........... 85

Clark, T. E.,fichtelite....................... 711

Clark, W. B., greensand..................... 493

Clarke, F. W., age of ocean................ 137-142

alteration of iolite....................... 386

analyses by. 60,145,147,172,182,442,533,616,664 

average composition of igneous rocks..... 24-27

brucite-serpentine................. 394,577,579

chemical denudation............... 56,106,137

constitutional formulae.................. 574

constitution of amphiboles.............. 368

of pyroxenes........................ 364

evolution of the elements................ 12

formula of cancrinite.................... 355

' glauconite and greenalite.............: 493,548

roscoelite................................ 372

solubility of minerals.................... 456

' theory ofchlorites..................... 377,378

total run-off of rivers.................... 56

Clarke, F. W., and Catlett, C., nickel ore.. 662,672 

Clarke, F. W., and Darton, N. H., iron mica. 372 

Clarke, F. W., and Diller, J. S., alteration of

topaz............................ 388

nickel silicate........................... 663

Clarke, F. W., and Schneider, E. A., calcination of talc...................... 395

formation of spinel.................... 325,378

micas and vermiculites.................. 376

Clarke, F. W., and Steiger, G., ammoniumanalciteand leucite.............. 350

vesuvianite............................. 383

Claude, G., composition of air............... 40,43

Claudetite................................... 659

Claus, C., phosphatic sandstone............. 515

Clausthalite................................. 645

Claypole, E. W., tin deposits................ 656

Clays..................................... 483-491

dehydration of........................ 583-587

plasticity of............................. 478

Clays, oceanic..................... 120,127,488-490

Clear Lake, analysis of hot spring near....... 186

Clement, J. K. See Alien, E. T.

Clements, J. M., iron ores................. 329,546

Clemm, W., silication of limestones.......... 534

Clermont, P. de, and Frommel, J., solubility

of sulphides................... 603,608

Cleveite..................................... 676
742 INDEX.

Page. 

Climate, influence of carbon dioxide on...... 46,47

Clinochlore.................................. 377

Clinoclasite.................................. 632

Clinohedrite..................:.............. 641

Clintonite................................... 373

Cloez, S., hydrocarbons in iron............ 690,695

Clouet, J., synthesis of chromite............. 666

Clough, C. T., and Pollard, W., occurrence

of olivine........................ 371

Clowes, F., bary tic deposits................. 553

bary tic sandstones...................... 515

Cowes, F., and Biggs, J. W. H., solubility of

oxygen in sea water............. 130

Coal....................................... 705-731

Coates, C. E., and Best, A., petroleum....... 685

Cobalt, distribution......................... 15

in ashes of sea weeds.................... Ill

ores of................................. 660-664

Cobaltite....................:.t ............. 660

Cochenhausen, E. von, water analysis....... 144

Codington, E. W., phosphate rock.......... 502

Cohen, E., matrix of diamond............... 308

salt lake in Transvaal................... 162

Cohen, E., and Raken, M., solubility of calcium carbonate.................. 118

Cohn, F., travertine......................... 525

Cole, G. A. J., bauxite....................... 473

Cole, G. A. J., and Little, O. H., calcite and

aragonite in fossils............... 528

Coleman, A. P., anthraxolite................ 720

corundum-nepheline syenite............. 322

heronite............................... 352,426

magnetic assimilation.................... 295

nickel deposits........................... 661

Colemanite........................ 234,235,236,240

Collet, L. W., oceanic deposits............. 119,493

phosphatic nodules...................... 123

See also Bran and Collet.

Collet, L. W., and Lee, G. W., glauconite... 493 

Collier, A. J., tin deposits..............'...... . 655

Collier, P., nativeplatinum.................. 669

Collins, H. F., mercury ores................. 634

Collins, J. H., nickel deposits................ 662

tin ores.................................. 653

Collins, W. D., analyses of water............ 65,

66,67,68,69,70,71,73,74,76,77 

Collophanite............................... 496,499

Collot, L., distribution of barium and strontium. ........................... 553

Collyrite..................................... 584

Colomba, L., alteration of glaucophane...... 369

Colorado River (Argentina), analysis of water. 83 

Colorado River (Arizona), analysis of water.. 77

flow of................................... 77

Colorado River (Texas), analysis of water... 77 

Coloradoite..............................:. 616,634

Columbia River, analysis of water........... 78

Columbite,................................ 656,678

Columbium, distribution.................... 15

sources.................................. 678

Colvocoresses, G. M., cobalt ores............. 663

Comanducci, E., copper and cobalt in volcanic

ash.............................. 601

Conchite..............................;...... 527

' Conichalcite................................. 632

Connarite.................................... 664

Page. 

Conneautsville well, analysis................ 174

Consanguinity of rocks...................... 293

Contamination of river waters.............. 99,100

Convection in magmas..................... 296,297

Cook, E. H., cited........................... 45

Cook, G. H., clays........................... 484

greensand marl.......................... 493

marl..................................... 526

native iron.............................. 312

Cooke, J. P., vermiculites.................... 376

Cooke, W. T. See Mawson and Cooke. 

Cookeite..................................... 372

Cookose..................................... 439

Coolgardite.................................. 615

Coomara-Swamy, A. K., Ceylonese graphite. 310 

corundum............................... 321

minerals in limestone.................... 596

Cooper, A. S., origin of petroleum............ 700

Copal........................................ 707

Copiapo, Rio, analysis of water.............. 84

Copper, distribution......................... 16

in sea water............................. Ill

ores of................................. 625-633

Coppock, J. B., cited........................ 114

Coquand, H., antimony ores................. 658

bauxite.................................. 472

borates.................................. 234

itabirite................................. 582

Coquina................................... 530,533

Coral...................................... 531,533

silicification of......................... 492,519

Coral rock............................. 531,540,541

Cordierite................................... 385

Cornet, F. L., phosphatic chalk............. 501

Cornet, J. See Renard and Cornet. 

Cornish, V., and Kendall, F. F., calcite and

aragonite in shells............... 528

Cornu, F., acid reactions of minerals......... 454

calcium carbonate....................... 193

color of salt.............................. 220

hibschite................................ 391

rock-forming apophyllite................ 395

tests for calcite and dolomite............. 539

See also Redlich and Cornu. 

Coronadite.................................. 510

Corongamite, Lake, analysis of water........ 162

Corse, M. B., and Baskerville, C., analysis by. 494 

Corstorphine, G. S., matrix of diamond...... 309

Cortese, E., hot springs of Venezuela........ 232

Cortlandtite............................... 440-442

Cortlandtose...................... i.......... 442

Corundophilite.............................. 377

Corundum............................ 319-324,595

Corundum rocks....................... 322,323,444

Corynite..................................... 660

Cosalite.................................... 623,647

Cossa, A., synthesis of scheelite.............. 667

tellurium in sulphur..................... 257

volcanic sublimates...................... 257

Cossyrite.................................... 369

Costachescu, N., gases in salt.............. 219,698

Coste, E., origin of petroleum............... 695

salt and oil............................. 218

Cotunnite................................... 648

Cove Creek, Utah........................... 190

Covellite.................................... 628
INDEX. 743

Page.

Coward, H. F. See Bone and Coward. 

Cowen, J. L., arsenic mine.................. 659

Cox, E. T., antimony ores................... 659

phosphate rock.......................... 502

Craig, A. W., and Wilsmore. N. T. M., water

analysis......................... 162

Cramer, E., volatility of silica..........'..... 260

Cransac, analysis of water from.............. 186

Craw, J. W., analysisby.................... 187

Crawley, J. T., and Duncan, R. A., absorption of potassium by soils....... 200

Credner, H., native copper.................. 626

Crednerite................................... 632

Crenshaw, J. L. See Alien, Johnston, and

Crenshaw. 

Cresson, C. M., cited........................ 66

Crinoids, composition of..................... 540

Cristobalite........................... 339,340,342

Crocidolite.................................. 368

Crocoite..................................... 650

Cronstedtite............... 377 > 548

Crook, A. K., molybdenite.................. 667

Crook, T., and Davis, G. M., fluorite in sand. 480 

Crook, T., and Jones, B. M., geildelite....... 331

Crookes, Sir W., artificial diamond.......... 308

Crookesite................................... 628

Crosby, W. 0., coloration of clay............ 484

sandstone dikes......................... 517

Crosnier, L., crystallized sands.............. 514

Cross, C. F., and Bevan, E. J., lignocellulose. 706 

Cross, W., analcite basalt.................... 352

analcite in phonolite...........'......... 426

classification of rocks.................... 404

epidote.................................. 571

garnet in rhyolite....................... 382

phlogopite in wyomingite............... 376

quartz-alunite and quartz-diaspore

rocks.......................... 247,474

sandstone dikes......................... 517

topaz in rhyolite........................ 388

See also Iddings and Cross.

Cross, W., and Hillebrand, W. F., cryolite.. 319 

Cross, Iddings, Pirsson, and Washington,

quantitative classification....... 403

Crossite..................................... 368

Cruzy well, analyses......................... 176

Cryolite..................................... 319

Cryophyllite................................ 372

Cryptomorphite............................. 238

Crystallization, fractional, in magmas....... 296

Cubanite.................................... 628

Cumberland River, analysis of water........ 73,98

Cumberlandite.............................. 445

Cumenge, E. See Friedel and Cumenge. 

Cumengeite................................. 649

Cummingtonite............................. 364

Cundell, J. T., and Hutchinson, A., zincite.. 641 

Cunningham, J. A., order of deposition of

minerals........................ 292

' Cuprite..................................... 632

Cuprobismutite............................. 631

Cuprodescloizite............................. 651

Cuproiodargyrite............................ 625

Cuprotungstite............................. 667

Curie, M. S., radioactivity................... 304

Curie, P., and Laborde, A., heat from radium. 299

Page. 

Currie, J., cited, on Stassfurt salts........... 210

Curry, J. E., water analyses................. 75

Curtis, J. S., gold and silver in quartz porphyry ........................... 601

origin of lead ores....................... 652

Cusack, R., melting points of minerals.... 278,279

Cushman, A. S., plasticity of clays.......... 478

solubility of minerals.................... 456

Cushman, A. S., and Hubbard, P., extraction of potash from feldspar..... 456

Custerose................................... 442

Cyanite. See Kyanite.

Cyanchroite................................. 258

Cylindrite................................. 647,652

Cymatolite.................................. 361

Cyrtolite.................................... 680

D. 

Dacite...................................... 430

Dafert, F. W.,caliche........................ 242

Dahllite................................... 338,499

Dahms, P., analysis by..................... 564

Dale, T. N., slate............................ 524

Ball, W. H., coquina........................ 630

Dall, W. H., and Harris, G. D., Florida

phosphates...................... 497

Dallas, mineral spring near, analysis ........ 178

Dalmer, K., metamorphosis of phyllito.... 378,584

Dalton, L. V., origin of petroleum........... 702

Daly, R. A., average composition of rock

types............................ 399

evolution of limestones.................. 533

magmatic stoping....................... 295

origin of alkaline rocks.................. 423

pro-Cambrian ocean..................... 129

the fundamental magma................ 26

Damour, A. A., analysis by ................. 196

native platinum......................... 669

predazzite............................... 544

titanolivine............................. 370

Damourite.................................. 372

Dan River, analysis of water................ 67

Dana, J. D., dolomitization..:.............. 541

gypsum and salt...................... 217,218

serpentine............................... 576

volume of ground water................. 33

Dana, E. S., thinolite....................... 148

See also Brush and Dana.

Dana, E. S., and Penfield, S. L., lead silicate. 651 

Danalite.................................... 641

Dannemorite................................ 364

Danube River, analysis of silt............... 481

analyses of water........................ 92,98

Daphnite.................................... 377

Darapskite................................ 242,243

Darapsky, L., Chilean borates............... 237

Chilean nitrates....................... 242,245

Darton, N. H., Florida phosphates.......... 497

See also Clarke and Darton. 

Darwin, C., volcanic islands................. 297

Dathe, E., scapolite rocks................... 571

Datolite..................................... 396

Daubr6e, A., alteration of bronze............ 629

arsenic in sea water...................... 110

arsenic and antimony in basalt.......... 601

associations of platinum................. 670
744 INDEX.

Page. 

Daubrie, A., calcination of serpentine...... 357,394

ferrous chloride in native iron........... 129

formation of galena...................... 646

of hyalite and zeolites at Plombieres. 199 

of olivine............................ 370

fossil charcoal........................... 712

origin of cassiterite...................... 655

of native iron...................... 312,313

sea water and volcanism................. 271

solubility of orthoclase................. 349,454

synthesis of apatite...................... 337

of brookite.......................... 333

ofcassiterite................... 335,652,653

of diopside.......................... 360

of enstatite.......................... 357

of gahnite........................... 642

of hematite.......................... 329

of quartz............................ 340

of topaz............................. 388

of willemite......................... 642

of zinc ores.......................... 641

zeolites at Plombieres................... 396

Daubr6e, A., and Meunier, S., native iron... 312 

Daubr&ite.................................. 659

Daubreelite................................. 664

Daudt, H. W., analysis by.................. 152

David, T. W. E., glendonite................ 148

matrix of diamond...................... 309

Davidson, W. B. M., phosphate rocks..... 497,502

Davies, D. C., Welsh phosphates............ 501

Davies, G. M. See Crook and Davies. 

Daviesite.................................... 649

Davis, C. A., diatoms in peat................ 199

marl.................................... 526

peat..................................... 709

Davison, C., loess........................... 486

Davison, J. M., platinum,etc.,in meteorites.. 671 

Dawson, H. M. See Van't Eofi, Ken'rick,

and Dawson. 

Dawson, J. W., origin of gypsum.......... 238,550

peat..................................... 711

spore cases in coal....................... 729

Dawsonite....................'.............. 475

Day, A. L., melting points of minerals. 278,279,282

Day, A. L., and Alien, E. T., fusion of feldspars .......................... 278,346

sublimation of feldspars................. 260

syntheses of feldspars.................. 346-348

Day, A. L., and Shepherd, E. S., akermannite silicate....................... 379

formation of quartz and tridymite..... 339-341

lime silicates...................... 278,288,359

phase rule............................... 290

volatility of quartz...................... 260

Day, A. L., and Sosman, R. B., melting

points of minerals............... 278

Day, D. T., filtration of petroleum........... 704

phosphate rock.......................... 504

platinum................................ 670

Day, D. T., and Richards, R. H., platiniferous sands........................ 670

Day, W. C., artificial asphalt................ 693

gilsonite................................. 687

pitch coal............................... 688

Dead Sea.............................. 155-157,163

Death Gulch, water from.................... 194

Page. 

De Benneville, J. S., potash in beryl......... 393

Debray, H., synthesis of apatite............. 337

synthesis of pyromorphite............... 651

of scheelite.......................... 667

of silver halides...................... 625

See also Deville and Debray. 

Dechen, H. von, cerusite sinter.............. 648

Decomposition of rocks.................... 452-512

Dedolomitization............................ 596

Dee, River, analysis of water................ 85

De Groot, H., California borates........... 234,235

De Gouvenain, , fluorine in Vichy water. 180 

De Launay, L. See Launay, L. De. 

Delaware River (Kansas), analysis of water. 75 

Delaware River (N. J.), analyses of water.... 66

Delebecque, A., Lac L6man................ 85

Delebecque, A., and Duparc, L., French lakes 85 

Delesse, A., volume of ground water......... 33

Dellessite.................................... 377

Delkeskainp, R., barium in natural waters. 193,

515,553 

bauxite................................. 473

vadose and juvenile carbonic acid..... 202,203

Delvauxite.................................. 673

Demaret, L., zinc deposits................... 638

Demargay, E., vanadium................... 673

Demel, W., dopplerite....................... 711

Dennis, W. D., cited........................ 236

Denudation, aerial.......................... 126

Denudation, chemical..................... 102-108

Denver, spring near, analysis................ 176

Derby, 0. A., Brazilian diamonds........... 309

Brazilian topaz.......................... 388

disintegration of rocks................... 458

gold on limonite......................... 616

manganese ore........................... 510

novaculite............................... 518

occurrence of monazite and xenothne.... 338

Derbylite................................... 659

Desaulesite.................................. 664

Des Cloizeaux, A., formation of anorthite.... 347

nickel ores............................... 661

Descloizite............................ 641,651,674

Des Moines River, analysis of water......... 72

Deville, C. Sainte-Claire, dolomitization..... 535

fumaroles of Vesuvius................... 250

Deville, C. Sainte-Claire, and Leblanc, F.,

boric fumaroles.................. 238

volcanic gases......................... 250,251

volcanic sublimates..................... 257

Deville, H. Sainte-Claire, synthesis of cassiterite........................... 335,653

synthesis of hematite.................... 329

of magnetite......................... 327

of willemite......................... 642

of zeolites........................... 396

of zircon............................. 336

titanium and vanadium in bauxite.... 476,673

topaz.................................... 388

water analyses.......................... 86,89

Deville, H. Sainte-Claire, and Caron, H.,

synthesis of apatite.............. 337

synthesis of cassiterite................. 335,653

of galmite........................... 642

of pyromorphite..................... 651

ofrutile............................. 333
INDEX.

Page. 

Deville, H. Sainte-Clalre, synthesis of staurolite(?).......................... 390

synthesis of zircon....................... 336

Deville, H. Sainte-Claire, and Debray, H.,

native platinum............... 669,670

synthesis of cinnabar.................... 636

Deville, H. -Sainte-Claire, and Troost, L.,

occlusion of gases by glass...... 263

synthesis of greenockite and wurtzite.... 639

Deville, H. Sainte-Claire, and Wo'hler F.,

boron nitride.................... 233

Devil's Inkpot, analysis of water............ 188

Devil's Lake, analysis of water.............. 152

Dewar. J., cited............................. 43

Dewar, J., and Ansdell, G., gases in meteorites 273 

Dewey, F. P., solubility of gold.............. 618

Deweylite................................... 395

De Wilde, P., gold in sea water.............. Ill

origin of petroleum...................... 697

Diabantite.................................. 377

Diabase..........'....................- 437,438,464

Diallage................................... 360,564

Diamond.................................. 306-310

Diaphorite......;......................... 623,647

Diaspore...................... 320,471,472,473,474

Diatom ooze........................... 120,488,489

Diatoms, as sources of petroleum............ 701

in peat.................................. 199

Dick, A. B., minerals in sand............... 479

Dickson, C., formation of barite............. 555

Dickson, C. W., nickel deposits.............. 662

platinum ores........................... 672

Dickson, E. See Holland and Dickson. 

Dieffenbach, O., gold on siderite............ 616

Diersche, H., origin of graphite.............. 310

Dietze, A., water analysis................... 84

Dietzeite.................................. 243,665

Dieulafait, L., ammonia in sea water........ 110

bitumen in shale......................... 698

boric acid in natural waters............. 185

Chilean nitrates......................... 243

copper in sea water...................... Ill

lithium in sea water..................... 110

manganese in sea water................. Ill

manganese nodules...................... 121

origin of borates......................... 240

precipitation of iron ores................ 545

serpentine............................... 577

strontium in sea water .................. 110

sulphur deposits........................ 552

thermochemistry of iron and manganese.. ................................. 511

vanadium............................... 673

zinc and copper in rocks................. 602

zinc in limestone...................... 642,643

in sea water......................... ill'

D iller, J. S., alteration of pyrope............ 382

loess.......................:............ 486

melilite and gehlenite in slags........... 379

occurrence of perofskite.................. 332

priceite.................................. 236

quartz basalt.......................... 344,434

sandstones............................ 516,517

See also Clarke and Diller. 

Diopside.............................. 359,360,576

melting point........................... 279

Page. 

Dioptase.................................... 633

Diorite................................ 430,433,464

Dipyre...................................... 383

Dissociation in magmas..................... 446

Ditte, A., metals in the atmosphere......... 51

origin of vanadates...................... 674

synthesis of apatite ..................... 337

of cassiterite....................... 335,653

of cinnabar........................ 635,636

of greenockite....................... 640

Dittler, E., melting points of silicates........ 280

synthesis of plagioclase.................. 347

Dittmar, W., analyses of dissolved air.. 130,131,133 

analyses of ocean water.................. 112

oceanic salts............................. 23

water of Hayes River................... 80

Dittmarite..........................:....... 496

Ditroite..................................... 423

Dittrich, M., decomposition of rocks... 454,462,477 

relations between spring waters and rocks 201 

Ditz, H. See Donath and Ditz. 

Divers, E., and Shimidzu, T., tellurium in

sulphur......................... 257

Dniester, River, analysis of water........... 95

Dodge, J. A., analysis of water.............. 71

Doelter, C., alteration of andalusite.......... 390

constitution of pyroxene................ 364

formation of augite...................... 363

of anorthite......................... 347

of magnetite......................... 328

of melilite........................... 380

of spinel............................. 325

fusibility of rocks.................. 280,281,282

fusion of clinochlore..................... 378

of epidote........................... 386

of garnet............................ 381

of glaucophane...................... 369

of micas............................. 376

of tourmaline........................ 393

gehlenite in limestone................... 595

magmatic dissociation................. 285,289

melting points of minerals............. 278,279

solubility of minerals.................... 334,

456,603,608,646,653,657 

solvent of gold.......................... 617

stability fields of minerals............. 290,293

synthesis of acmite...................... 361

of bournonite........................ 631

of cinnabar.......................... 635

of covellite and chalcopyrite.......... 629

of feldspar........................... 347

of galena............................ 646

of hornblende....................... 366

of jamesonite........................ 647

ofleucite............................ 350

of meionite.......................... 384

of mica.. .......................... 374,375

of nephelite and kaliophilite......... 354

of olivine............................ 371

of pyrite and pyrrhotite........... 316,317

of sulphosalts....................... 624

of wollastonite...................... 359

of zeolites........................... 396

volcanic chlorine........................ 129

volcanic explosions...................... 271
746 INDEX.

Doelter, C., and Hoernes, R., dolomitization. 542 

Doelter, C., and Hussak, E., formation of

anorthite........................ 347

formation of melilite...........'.......... 380

of spinel............................. 325

fusion of garnet.......................... 381

of mineral mixtures................. 295

of vesuvianite....................... 383

Doering, A., analyses by................... 84,224

cited.................................... 153

Doherty, W. M., manganese nodules........ 508

Dole, R. B., analyses of water............... 64,

65,66,67,68,69,70,71,73,74,76,77 

Dole, R. B., and Stabler, H., chemical denudation. .......................... 103

Dolerophanite............................... 258

Dolomite.......................... 235,397,534-545

Domeykite.................................. 628

Domoshakovo, Lake, analysis of water.... 159,163

saline deposits........................... 222

Don, River, analysis of water................ 85

Don, J. R., distribution of gold.............. 614

gold in sea water........................ Ill

solvent of gold........................... 618

Donath, E., action of nitric acid on coal... 715,716 

extracts from coal....................... 730

humus substances....................... 716

resinoids in lignite....................... 714

Donath, E., and Braunlich, F., reactions of

lignite........................... 718

Donath, E., and Ditz, H., reactions of lignite. 718 

Dopplerite................................. 710,711

Doss, B., anatase pseudomorphs............. 333

artificial hematite....................... 329

pseudobrookite.......................... 331

sand in gypsum......................... 514

synthesis of rutile and anatase........... 333

Doubs, River, analysis of water.............. 86

Doughty Springs............................ 193

Douglas, J. A., volume of molten minerals.. 281 

Douglasite................................. 213,214

Douro, River, analysis of water.............. 86

Drabble, G. C., see Wedd and brabble. 

Dragendorfl, J. G. W., analysis of water..... 95

Drasche, R., von, eclogite................... 572

Drevermann, A., syntheses of lead ores...... 650

Drown, T. M., chlorine maps................ 50

Duane, W., heat from radium............... 299

Duboin, A., synthesis of kaliophilite......... 354

synthesis of leucite...................... 350

Dubois, E., atmospheric transport of salt.... 51

chemical denudation...............:.... 137

circulation of calcium carbonate......... 119

ratio of sodium to chlorine in rivers...... 128

Du Bois, G. C., laterite.................... 469,470

Ducatte, F., sulphosalts of copper........... 631

sulphosalts of lead....................... 647

Ducloux, E. H., cited....................... 112

loess..................................... 485

Dudley, W. L.,vivianite..................... 496

Duffleld, S. P., analysis cited................ 170

D ufrenite.................................... 496

Dufrenoysite................................ 647

Dumas, J. B., origin of boric acid........... 233

synthesis of argentite.................... 621

Durable, E. T., grahamite................... 688

Page. 

Dumble, E. T., iron ores.................... 549

Dumont, J., decomposition of potassium

carbonate by clay............... 477

solubility of rocks....................... 456

Dumortierite................................ 391

Duncan, R. A. See Crawley, J. T.

Dundasite.........................'.......... 648

Dunin-Wasowicz and Horowitz, J., analysis

by.............................. 175

Dunite.................................... 440,442

Dunn, E. J., diamond....................... 308

Dunn, J. T., barium and strontium in mine

waters........................... 554

Dunn, W. H., analysis of salt................ 219

Dunnington, F. P., deposition of manganese. 511 

titanium in clays....................... 20,476

Dunose...................................... 442

Dunstan,W. R.,laterite..................... 470

Duparc, L., analysis of water................ 86

hot springs.............................. 527

transformation of pyroxene.............. 365

Uralian platinum....................... 670

See also Delebecque.

Duparc, L., and Holtz, H. C., Uralian platinum............................. 669

Duparc, L., and Hornung, T., uralitization. 365,563 

Durand-Claye, L., cited..................... 114

Durocher, J., copper sulphide................ 628

liquation in magmas..................... 297

synthesis of argentite.................... 621

of cinnabar.......................... 635

of dolomite.......................... 535

of galena............................. 645

of greenockite and sphalerite......... 639

of pyrite............................. 316

ofstibniteandbismuthinite......... 657

of sulphosalts........................ 624

the fundamental magmas................ 293

Dust, atmospheric.......................... £1,126

Dutoit, A. L., matrix of diamond............ 309

Dutton, C. E., radioactivity and volcanism. 301,302 

D wina, River, analysis of water............. 95

Dyscrasite................................... 621

Dysprosium................................ 16,679

E.

Eakins, L. G., analyses by ....... 176,324,362,414,

422,432,433,435,441,442,

486,487,522,533,544,587

fluorine in fossil bone.................... 500

xanthitane ............................. 333

Eakle, A. S., lawsonite...................... 391

East Saginaw, brine, analysis of............. 171

Eaton, F. M., see Van Winkle and Eaton. 

Ebaugh, W. C., and Macfarlane, W., Great

Salt Lake....................... 144

Ebaugh, W. C., and Williams, K., Great Salt

Lake............................ 144

Ebelmen, J. J., synthesis of beryl............ 393

synthesis of bunsenite................... 663

of chromite.......................... 665

of enstatite.......................... 357

of forsterite. ....................j.... 370

of gahnite........................... 641

of magnetite......................... 327

of perofskite......................... 332

of rutile............................. 333
INDEX. 747

Page. 

Eberhard, G., scandium..................... 19

Ecdemite................................... 651

Eckel, E. C., gypsum..........'............. 220

limestone and cement................... 533

phosphorite............................. 501

slate..................................... 524

See also Hayes and Eckel. 

Eclogite............................... 309,572,573

Edenite..................................... 365

Edingtonite................................. 395

Eger River, analyses of water ............... 90

Egger, E., analyses of water................. 88,89

Egglestone, W. M., fluorspar................ 556

Egleston, T., solvents of gold.............. 617,618

Eglestonite.................................. 634

Ehrlich, F. See Kolkwitz, R.

Eichleiter, C. F., arsenical spring............ 177

Eisenhuth, K., analysis by.................. 547

EUeolite................................... 353,354

Elffiolite syenite....'....................... 422,463

Elaterite......................- - 687

Elbe River, analyses of water............... 90

Elbow River, analysis of water.............. 81

Eldridge G. H., asphalt................... 687,689

Florida phosphates...................... 502

Electrum.................................... 615

Elements, distribution...................... 13-21

nature................................... 12-13

periodic classification.................... 34-38

relative abundance...................... 21-34

table of.................................. 13

Ellis, E. E., zinc deposits................... 644

Ellis, W. H., anthraxolito................... 720

Ells, R. W., manjak........................ 688

Elsden, J. V., chemical geology............... 11

Elton Lake, analysis of water............. 158,163

Embolite.................................... 625

Emerson, B. K., amphibolito................ 566

andalusite and sillimanite............... 585

emery................................... 322

serpentine............................... 576

Emery................................ 319,322,477

Emmons, S. F., fluorite..................... 556

loess..................................... 485

ores of Leadville......................... 652

platinum................................ 672

secondary enrichment................... 611

serpentine............................... 576

silver in eruptive rocks.................. 601

zinc ores................................ (44

Emmons, W. H., manganese and gold....... 618

molybdenite............................ 318

Emplectite.................................. 630

Enargite.................................... 631

Endell, K., acids of moor waters............. 460

origin of kaolin.......................... 468

Endemann, H., asphalt..................... 689

Endlichite.................................. 650

Engelhardt, F. E., analysis by ............ 171,499

Engler, C., artificial petroleum............ 692,693

origin of petroleum.................... 697,698

Engler, C., and Lehmann, T., artificial petroleum. ........................ 692

Enstatite.................................. 357,358

molting point........................... 279

Epecuto, Lagoon, analysis of water....... 153,163

Page. 

Epiboulangerite............................. 647

Epichlorite.................................. 377

Epidosite................................... 572

Epidote................................... 386-387

Epidote rocks............................. 571-573

Epidotization............................. 571-573

Epigenite................................... 631

Epistilbito.................................. 395

Epsomite.............................. 212,237,243

Erbium.................................... 16,679

Erdmann, , water analysis.............. 158

Erdmann, E., blue rock salt................. 220

Stassfurt salts................. 210,211,212,215

Erdmann, H., abundance of nitrogen........ 33

nitrogen in minerals..................... 261

Erhard, T., melting points of minerals....... 277

Erie, Lake, analysis of water................ 64

Erinite...................................... 632

Erionite..................................... 395

Erlau, River, analysis of water.............. 92

Erofeef, M., and Latschinofl, P., diamonds In

meteorite....................... 308

Erwin, R. W., cited.......................... 49

Erythrite................................... 663

Erythrosiderite............................. 258

Escher, B. G., igneous rocks................. 451

Essen, J. von, solubility of carbonates....... 525

Essexose.................................. 420,436

Etard, A., and Olivier, L., reduction of sulphates by microbes.............. 551

Ettinger, . See Franck and Ettinger. 

Eucairite.................................... 623

Eucryptite............................ 353,354,361

Euctolite.................................... 436

Eudialyte................................. 623,678

Europium.................................. 16,679

Eutectics.......................... 286-290,401,402

Euxenite.................................... 678

Evansite.................................... 496

Evans, J. R., analyses of water........ 68,69,73,76

Evans, J. W., analcite in monchiquite....... 352

quantitative classification............... 411

Evans, N. N., analysis by................... 592

Eve, A. S., radioactivity ................... 300

Eve, A. S., and Mclntosh, D., radioactivity.. 300 

Everding, H., Stassfurt salts................ 210

Ewald, , analysis by.................... 194

Ewing, A. L., limestone erosion............. 534

Excelsior Spring, analysis................... 180

F. 

Fahlunite................................... 386

Failyer, G. H., barium in soils.............. 14

See also Schreiner and Failyer. 

Failyer, G. H., and Breese, C. M., nitrogen

compounds in rain.............. 49

Failyer, G. H., Smith, J. G., and Wade, H. R.,

composition of soil particles..... 480

Fairbanks, H. W., analcite-diabase.......... 352

tin deposits............................. 655

Fairchild, H. L., planetesimal hypothesis.. 55,129 

Fairhaven Springs, analysis................. 182

Famatinite.................................. 631

Farr, C. C., and Florence, D. C. H., radium in

rocks............................ 300

Farrington, 0. C., formula of iolite.......... 385
748 INDE!.

Page.

Farup, P. See Van't Hofl and Fafup. 

Faujasite.................................... 395

Fayalite................................... 369,403

Feld, W., synthesis of pyrite................ 317

Feldspars................................. 345-349

alterations of.......................... 568-573

melting points..................... 279,280,346

sublimation of........................... 260

Femic minerals.............................. 405

rocks.................................. 440-443

' Fennel, A. C. See Judge, J. F. 

Fenneman, N. M., petroleum................ 685

Fenner, "C. N., resorption of olivine.......... 284

Ferberite.................................... ' 667

Fergusonite................................. 680

Fermor, L. L., manganese in laterite......... 471

manganese ores.......................... 510

Fernandez and Bragard, analyses by........ 554

Fernekes, G., precipitation of copper......... 627

Ferrier, W. F. See Weeks and Ferrier. 

Ferrieres and Dupont, synthesis of bunsenite. 663 

> synthesis of zincite....................... 641

Ferrodolomite. ............................... 547

Fibrolite...............................:...'. 389

Fichtelite.................................. 687,711

Fiedlerite...........'........................ 649

Field, F., analysis by........................' 548

! synthesis of copper minerals........... 632,633

Finckh, L., igneous rocks.................... 451

serpentine from gabbro.................. 394

Finlay, G. I., calculation of norms........... 410

 dumortierite............................. 392

Finlayson, A. M., genesis of lead and zincores. 643 

Fircks, W. von, tin deposits................. 654

I See Beck and Fircks. 

Fischer, F., coal analyses.................... 717

Fischer, H., formation of oolite.............. 529

mercury deposits........................ 638

Fischer and Rust, microscopic structure of

coal............................. 729

Fischer, T. See Wedding and Fischer. 

Fischerite................................... 496

Fish Creek, analysis of water................ 81

Fisher, 0., criticism of Joly.................. 137

; internal temperature of the earth........ 277

Fisher, W. W., water of Thames............ 85

Fitch, E. S., analysis of bittern.............. 221

Flagg, J. W., Chilean nitrates............... 242

Flechsig, R., analysis by.................... 182

Fleck, H., water analysis.................... 156

Fleck, H., and Haldane, W. G., carnotite... 676 

Fleischer, A., volume of molten basalt....... 281

Fleissner, H., diamonds in slag.............. 307

Fletcher, A. L., radioactivity of rocks....... 300

Flint.................................. 339,518-521

Flint River, analysis of water................ 68

Florance, D. C. H. See Farr and Florance. 

Fliickiger, F. A., analysis by................ 188

Fluocerite................................... 319

Fluorine, distribution....................... 16

free, in fluorite.......................... 319

in mineral waters........................ 180

in sea water............................. 109

Fluorite....................... 318,319,480,515,555

melting point............................ 279

Fluorspar. See Fluorite.

Foerste, A. F., Clinton iron ores............. 506

Forstner, H., wurtzite as furnace product.... 639

Fohs, F. J., fluorspar........................ 556

Foote, E. A. See Koenig and Foote.

Foote, H. W., analyses by......... 326,427,436,665

calcite and aragonite..................... 527

See also Penfleld and Foote. 

Foote,H. W.,and Bradley, W. M., nephelite. 353 

Foote, W. M., leadhillite.................... 649

Forbes, D., borate from hot springs.......... 240

Chilean nitrates......................... 242

South American borates............... 237,240

Forbes, E. H. See Penfield and Forbes. 

Forbes, R. H., and Skinner, W. W., water

analyses......................... 77

Forbesite.................................... 663

Forchhammer, G., chemistry of the ocean.. 109, 111 

heavy metals in rocks.................... 600

magnesia in shells and corals............ 540

synthesis of apatite...................... 337

Ford, W. E., formula of dumortierite........ 391

See also Penfleld and Ford. 

Forel, F. A., on Lac Leman................. 86

Formaldehyde in atmosphere................ 43

Formenti, C., bauxite....................... 474

Formulae, constitutional................... 574,575

Forsberg, , cited......................... 114

Forsberg, E. See Geuther and Forsberg. 

Forsterite............................. 369-371,403

Forstner, W., mercury ores.................. 638

Foster, C. Le Neve, Owens Lake............ 227

See also Bauerman and Foster. 

Foulk, C. W., analysis by................... 171

Foullon, H. B. von, gummite................ 676

nickel deposits........................ 661,663

rhodusite................................ 368

FouquS, F., formation of melilite............ 379

magmatic differentiation................ 284

steam from Etna........................ 249

volcanic gases.................. 251,252,254,255

Fouque, F., and Gorceix, H., boric fumaroles. 234 

Fouque', F.,and Michel LeVy, A., crystallization Of Silica..................... 343

formation of hematite.................... 330

of magnetite......................... 328

of melanite.......................... 382

of nephelite.......................... 354

of spinel............................. 325

fusion of biotite and microcline.......... 425

of scapolite rock..................... 384

scapolite gabbro......................... 570

synthesis of augite....................... 363

of enstatite.......................... 358

of feldspars........................ 346,347

ofleucite............................ 350

of melilite........................... 379

of mica trachyte..................... 374

of olivine............................ 370

Fournet, J., synthesis of chalcopyrite........ 628

synthesis of zinkenite.................... 647

Fox, C. J. J., carbon dioxide in sea water.... 134

Foyaite..................................... 423

Fraas, O. F., formation of bitumen.......... 699

Fraatz, T. See Werner and Fraatz.

France, lakes of............................. 85

Franchi, S., glaucophane rocks.............. 565
INDEX. 749

Franchi, S., jadeiterocks.................... 361

Franchi, S., and Stella, A., lawsoniteinsctiist. 391 

Franck, L., and Ettinger, diamonds in steel. 307 

Franckeite................................ C47,652

Francolite................................... 499

Frank, A., iodine in potash salts............. 211

Frankforter, G. B., water from Death Gulch. 194 

Frankland, P. F., coal gas.................... 722

water analysis............................ 83

Franklin, E. C. See Bailey, E. H. S. 

Franklinite........................ 324,641,642,645

Fraps, G. S., and Tilson, P. S., water of Rio

Grande.......................... 76

Frazer, J. C. W. See Kastle, J. H., etc.

Frazer, P., classification of coals........... 722,723

Frear, W., and Beistle. C. P., soils........... 484

Frech, F., carbon dioxide and climate....... 47

Freda well, analysis cited.................... 174

Freda, G., volcanic sublimates............... 257

Free, E. E., aerial denudation............... 126

Freis, R., fusion of mineral mixtures......... 291

Freieslebenite............................. 623,647

Fremy, E., artificial coal.................... 727

humie substances in coal.............. 714,715

synthesis of angiesite.................... 649

of cerussite.................... 648

Frenzel, A., Bolivian tin ores................ 652

formula of pseudobrookite............... 331

mine water.............................. 604

Fresenius, C. R., analysis by................ 173

manganese and iron in spring waters..... 510

Friedel, C., diamond........................ 307

lead oxychlorides........................ 649

nesquehonite............................ 538

synthesis of atacamite................... 632

Friedel, C., and Cumenge, E., camotite...... 676

Freidel, C. and G., alteration of muscovite... 376 

artificial cancrinite...................... 356

conversion of muscovite into nephelite... 354 

formation of leucite...................... 351

syntheses of feldspars.................. 347-348

Friedel, C., and Gue"rin, J., synthesis of ilmenite............................... 331

Friedel, C., and Sarasin, E., formation of

quartz and feldspar.............. 348

synthesis of analcite..................... 351

of hopeite............................ 641

of phosgenite........................ 648

of quartz and tridymite.............. 340

of topaz............................. 388

Friedel, G., hydration of analcite............ 350

lead oxychlorides........................ 649

synthesis of corundum................... 320

Friedel, G., and Grandjean, F., synthesis of

chlorite.......................... 378

Friedlander, J., artificial diamond........... 307

Frieseite..................................... 623

Frio, Rio, analysis of water............\..... 84

Friswell, R. J., action of nitric acid on coal.. 715 

Frochot, M., tin deposits.................... 656

Frommel, J. See Clermont and Frommel.

Frtih and Schroter, peat..................... 710

Fuchsite..................................... 372

Fuller, M. L., corrosion of quartz.......... 345,457

volume of ground water................. 33

Fuller's earth.............................. 484,704

Page. 

Fuinaroles................................. 250-256

Fumaroles, boric.......................... 232,233

Funafuti, atoll of............................ 542

Funk, W., decomposition of feldspars....... 456

Fyris, River, analysis of water............... 94

G. ' 

Gadolinite................................... 680

Gadolinium................................ 1C, 679

Gabbro.................................... 439,440

Gaertner, A., bog-iron ore................... 506

Gagcl, C., and Stremme, H., origin of kaolin.. 469 

Gages, A., synthesis of serpentine........... 394

Gahnite........................... 324,641,642,645

Gaize........................................ 518

Gale, H. S., carnotite...................... 676,677

Gale, H. S., and Richards, R. W., phosphate

rock............................. 503

Gale, L. D., cited........................... 143

Galena............................ 318,603,645-647

Galena, volcanic............................. 2f>8

Galenobismutite............................ 647

Gallium, distribution....................... 16,638

Ganomalite................................. 651

Garda, Lago di, analysis of water............ 88

Garnet.................................... 380-383

Garnet rocks.......................... 572,573,597

Gamier, J., nickel deposits................ 662,664

Garnierite................................... 664

Garonne, River, analysis of water........... 86

Gas, natural................... 682,684,685,686,697

Gases in coal.............................. 723-726

Gassner, L., phosphatization................ 534

precipitation of metals................... 612

Gaubert, P., cristobalite..................... 339

Gaukhane Lake, analysis of water......... 158,162

Gautier,- A., arsenic in sea water............. 110

chemistry of volcanism................ 263-267

decomposition of galena................. 646

fumarole gases........................... 270

galena................................... 646

hydrogen in atmosphere................. 43

iodine in. sea water...................... 109

minervite............................. 498,499

nitrogen, argon, arsenic, iodine in granite. 415 

occluded and volcanic gases........... 263-207

origin of nitrates......................... 245

reduction of copper sulphide............. 627

thermal springs and volcanism........ 202,203

Gautier, F., tin deposits..................... 655

Gay Lussac, cited........................... 48

formation of hematite................... 329-

Gaylussite..................... 148,227,235,237,243

Gebbing, J., cited........................... 87

Gebbart, M., synthesis of barite............. 555

Gedrite...................................... 364

Gedroiz, H., humus in soils.................. 460

Gegenbaur, V., water of the Adriatic........ 112

Gehlenite.............................. 379,380,595

Geijer, P., magnetite syenite................ 445

Geikio, Sir A., bog-iron ore.................. 505

elevation of continents................... 30

order of magrnatic eruptions............. 296

salin^ matter in rivers................. 103,105

temperature of molten laVa.............. 282

Geikielite.................................... 331
750 INDEX.

Page. 

Geitner, C., synthesis of argentite............ 621

synthesis of beyrichite................... 661

of greenockite....................... 640

of pyrite............................. 317

Genesee River, analysis of water............. 65,98

Genth, F. A., alteration of corundum........ 323

alteration of orthoclase to albite......... 349

of talc............................. 365,395

analyses by........................... 156,581

gummite................................ 676

lansfordite............................... 538

pseudomorphous cassiterite.............. 653

vermiculites............................. 376

water of Dead Sea. ..................... 156

Genth, F. A., and Penfield, S. L., nesquehonite........................... 538

Genthite.................................... 664

Geocronite.................................. 647

Geological thermometer............... 216,217,342

George, R. D., tungsten deposits............ 668

Georgiadesite ............................... 649

Gerhardtite................................. 663

Germanium................................. 16

Gersdorffite.................................. 600

Geuther, A., formula of gypsum............. 212

Geuther, A., and Forsberg, E., synthesis of

wolframite...................... 667

Geyserite.................................. 195,196

Gibb, A., and Philip, R. C., precipitation of

silver sulphide.................. 622

Gibbsite........................... 471,472,474,475

Gibson, J., analysis of manganese nodule.... 122

See also Irvine, R. 

Gigantolite.................................. 386

Gil, J. C., fluorine in spring waters.......... 180

barium, etc., in spring waters........... 173

Gila River, analysis of water................ 77

Gilbert, G. K., Lake Bonneville............. 143

mirabilite at Great Salt Lake............ .222

salts of Sevier Lake...................... 223

tufa..................................... 525

Gilbertite................................... 372

Giles, W.B.,bakerite....................... 236

Gillman, F., nickel deposits................. 662

Gilpin, J. E., and Bransky, O. E., fuller's

earth............................ 704

Gilsonite.................................. 686,693

Girard, C., and Bordas, F., spring deposits... 193 

Girardin, J., magnesian travertine........... 536

Gismondite.................................. 395

Glance coal.................................. 712

Glasenapp, M., niter in sandstone............ 241

Glaser, M. See Kalmann, W.

Glaserite.................................... 212

Glass, occlusion of gases by................ 262,263

Glasser, B., nepouite........................ 664

Glauberite..................... 212,216,235,237,243

Glaucochroite............................... 370

Glaucodot................................... 660

Glauconite..................... 124,492-494,547,548

Glaucophane................................ 368

Glaucophane schists....................... 565,566

Gleditsch, E., uranium and radium......... 304

Glendonite.................................. 148

Glenn, W., chromite deposits................ 666

Glinka, K., glauconite..................... 493,494

Page. 

Glinka, K., kaolin .......................... 475

weathering of minerals .................. 459

Globigerina ooze....................... 120,488,489

Glucinum, distribution...................... 16

Gmelinite................................... 395

Gmundenersee, analysis of water............ 88

Gneiss................................. 462,591-593

Goebel, A., cited............................ 158

Gockel, A., radioactivity of rocks............ 300

Godeffroy, R., analysis of water............. 88

Gorgey, R., salts of Hall, Tyrol.............. 216

Goessmann, C. A., analyses by............ 171,221

Goethite.................................... 504

Gotz, J., ottreliterocks...................... 586

Gold, distribution........................... 16

in igneous rocks....................... 316,613

in sea water............................. Ill

ores of................................. 613-619

solvents of............................. 617-619

Goldberg, A., cited.......................... 182

Goldschmidt, V., composition of tourmaline.. 392 

Gooch, F. A., analyses by................... 192

Gooch, F. A., and Whitfleld, J. E., analyses

by......................... 182,185,188

Goodenough Lake, analysis of water....... 151,164

Gorby, S. S., petroleum..................... 702

Gorceix, H., volcanic gases.................. 255

See Fouqufi and Gorceix. 

Gordon, C. H., change of augite to hornblende.... ....................... 564

nomenclature of gneiss................... 591

Gorgeu, A., analyses by..................... 509

synthesis of fayalite...................... 371

of nephelite......................... 354

of pseudo-wollastonite............... 359

of pyroxene.......................... 360

of spessartite........................ 381

of willemite.......................... 642

of zincite............................ 641

Gortner, R. A. Sec Alway, F. J. 

Gorup-Besanez, E. von, formation of magnesian carbonates................ 536

Goslarite.................................... 641

Gosling, E. B., ozokerite..................... 687

Goss, A., water analysis..................... 77

Gosselet, J., phyllites........................ 586

Gossner, B., on glaserite..................... 212

Gottlieb, E., analyses of wood............... 706

Gottschalk, V. See Buehler and Gottschalk. 

Gouvenain, C. A. de, alteration of bronze.... 629

Goyder, G. A., sulvanite..................... 674

Grabau, A. -W., classification of sedimentary

rocks............................ 513

Graftiau, J., cited............................ 44,49

Graham, T., colliery gases................... 726

gases from meteorites.................... 272

Graham, T., Miller, W. A., and Hofmann,

A. W., water of Thames......... 85

Grahamite............................. 674,687-689

Gramann, A., alteration of andalusite........ 390

Grand River, analysis of water.............. 65

Grandjean, , formation of dolomite....... 541

Grange,, J., analyses of water................. 86

Granite................................ 415,463,590

fusibility................................ 282

radioactivity of........................... 301
INDEX. 751

Page. 

Granite, sulphur waters from................ 203

Granitite.................................... 412

Grant, U. S., zinc deposits................... 644

Graphite.............................. 310,311,720

Graphitic acid............................... 720

Graphitoid.................................. 720

Graton, L. C., tin deposits................. 335,655

See also Hess and Graton. 

Gray, G., impurities in air................ 44,49,50

Graywacke................................ 516,517

Great Salt Lake, analyses of water.......... 144,162

Greenalite................................. 493,548

Greenleaf, J. L., flow of the Mississippi........ 71

Greenlee, W. B., volume of ground water..... 33

Greenockite............................... 639,640

Greensand. See Glauconite.

Greinacher, H., radioactivity................ 300

Greiner, E., silicate fusions...... '............ 293

Greisen.................................... 654,655

GreshoS, M., analysis by, cited.............. 186

Griffiths, A. P., mercury ores................ 638

Grimsley, G. P.,clays....................... 484

gypsum................................ 220,550

 Griswold, L. S., novaculite.................. 518

Groddeck, A. von, sericitic rocks............ 567

topazfels................................. 388

Grossraann, M., gases from lava.............. 268

Grossularite................................. 380

Groth, P., constitution of kyanite........... 388

Ground water, volume of.................... 33

Grout, F. F., average composition of Minne-

, sota rocks....................... 24

copper in country rock.................. 626

plasticity of clays........................ 478

Grubenmann, U., crystalline schists......... 562

glaucophane rocks....................... 565

Griinerite................................... 364

Griinerite-magnetite schist.................. 583

Grunlingite.................................. 657

Guano.................................... 496-499

Guadalcazarite.............................. 634

Guanajuatite................................ 657

Giimbel, C. W. von, chloropite.............. 574

compression of lignite................... 726

dolomite................................ 540

glauconite............................. 492-493

itabirite................................. 582

origin of manganese nodules............. 121

Giinther, R. T., and Manley, J. J., water

analysis......................... 158

Giinther, S., interior of earth................ 55

Gudrin, J. See Friedel and Gu6rin.

Giirich, G., ore deposits. ..^.................. 599

Giieymard, E., platinum in chalcocite....... 671

Guignet, E., action of nitric acid on coal..... 715

Guignet, C. E., wax from peat............... 701

Guitermanite................................ 647

Gully, E. See Baumann and Gully. 

Gummite.................................... 676

Gunnarite................................... 660

Gunning, J. W., analyses of water........... 86,89

Gurlt, A., talc............................... 578

tungsten deposit......................... 668

Gustavsen, C- $ , analysis of water.......... 76

G.uthrie, F,; chaoge of obsidian to pumice... 283

Page. 

Guthrie, F., cryohydrates................... 287

eutectics.......................... 288,401,402

Gutzkow, F., analysis of bittern............ 221

Gypsum.............................. 212,216,217,

218,220,235,237,238,240,513,550 

Gyrolite............................. :.:.... 395

H.

Habermann, J., formation of gypsum........ 550

Hackmannite............................... 355

Haefcke, H., constitution of hornblende..... 3C7

Haefele, P. E., alteration of andalusite...... 390

Hagele, C. See Hell and Hagele.

Haehnel, 0., kaolinization................... 408

Haeussermann, F., arid Naschold, W., coal

analyses......................... 719

Eager, L., salt deposits...................... 218

Hague, A., origin of Yellowstone hot springs. 201 

scorodite in spring deposit............. 197,657

Hahn, H., hydrocarbons in iron............. 690

Haldane, W. G. See Flack, and Haldane.

Hale, D.J., marl............................ 526

Halite..................................... 213,235

See also Salt. 

Hall, A. D., and Miller, N. J. H., nitrogen in

rocks............................ 33

Hall, C. W., and Sardeson, F. W., dolomite. 541 

Hall, Sir J., artificial coal.................... 727

fusion of limestone....................... 532

Hall, R. D.. and Lenher, V., tellurides. 616,619,623 

Halley, E., age of ocean.......".............. 137

Halloysite............................. 395,477,584

Hallstatt, Lake of, analysis of water......... 88

Halotrichite................................. 247

Halse, E., mercury ores..................... 634

tin deposits............................. 654

Hamberg, A., cited.......................... 130

native lead.............................. 645

Hamilton, N. D. See Parr and Hamilton. 

Hammerle, V., silicate fusions............... 291

Hammerschmidt, F., cited.................. 216

Hanamann, J., waters of Bohemia....... 90-92,201

Hancock, D. See Phillips and Hancock.

Hanks, H. G., California borates.......... 231,234

Hanksite.................................... 235

Hannay, J. B., artificial diamond......'...... 307

occlusion of gases by glass............... 263

Hannayite.................................. 496

Harder, E. C., manganese ores............... 510

Hardin, M. B., analysis by.................. 187

Hardman, E. T., analysis by................ 520

See also Hull and Hardman. 

Hardpan.................................... 460

Hardystonite................................ 641

Harger, H. S., diamonds..................... 309

Harker, A., average composition of igneous

rocks............................ 24

crystallization of magmas................ 297

origin of pegmatite...................... 412

primary iolite........................... 385

quantitative classification of rocks....... 411

Harkness, R., dolomite...................... 542

Harmotome................................. 395

Harney Lake, analysis of water............ 151,165

Harper, H. W., asphalt...................... 689
752 INDEX.

Page. 

Harperath, L., Argentine salt................ 219

petroleum and salt....................... 702

Harrington, B. J., analysis by............... 564

bornite.................................. 628

hydrogen sulphide in calcite........... 261,524

See also Adams and Harrington. 

Harris, G. D., salt deposits.................. 218

See also Ball and Harris. 

Harrison, J. B., heavy metals in rocks........ 602

laterite.................................. 470

rain water............................... 49,50

Harrison, J. B., and Jukes-Brown, A. J., coral

rock............................. 531

red clay................................. 489

Harrison, J. B., and Williams, J., chlorides in

rain............................. 50

nitrogen compounds in rain.............. 49

Harrogate, analyses of waters.............. 173,174

Hartite...................................... 687

Hartleb, R. See Stutzer and Hartleb.

Hartley, W. N., gases in rocks................ 261

reduction of sulphates.................... 136

Hartley, W. N., and Ramage, H., distribution

of rare elements ............ 27,504,619

Hartsalz................................... 213,214

Harzose................................... 428,430

 , water analysis............ 158

Hasslinger, R. von, artificial diamond........ 307

Hastings, J. B., gold ores.................. 613,615

origin of pegmatite...................... 412

Hastingsite.................................. 367

Hatch, F. H., classification of igneous rocks.. 404

diamonds................................ 308

Hatch, F. H., and Rastall, R. H., dedolomitization........................... 596

Hatchettite.................................. 687

Hauenschild, G., predazzite................. 544

Hauer, K. von, analysis of water............ 161

Hauke, M., eutecties......................... 291

Haiiynite.................................. 355-357

Haiiynophyre............................... 425

Haushofer, dolomite and magnesite.......... 539

solubility of minerals.................... 454

Hausmann, J. See Zaloziecki and Hausmann. 

Hausmann, J. F. L., wulfenite.............. 650

Hausmannite................................ 508

Hautefeuille, P., synthesis of enstatite........ 357

syntheses of feldspars.................... 347

of greenockite and wurtzite.......... 639

ofleucite............................ 350

of nephelite.......................... 354

of olivine............................ 370

of perofskite......................... 332

of quartz and tridymite.............. 341

of rutile, brookite, and anatase..... 333,334

titanite.............................. 332

vanadinite........................... 651

See also Troost and Hautefeuille. 

Hautefeuille, P., and Margottet, J., synthesis

of quartz and tridymite.......... 341

synthesis of staurolite (?)........:....... 390

Hautefeuille, P., and Perrey, A., crystallization of titanic oxide.............. 333

.synthesis of beryl........................ 393

of corundum......................... 320

at zircon.........,_........................ 336

Page. 

Hautefeuille, P., and Saint-Gilles, L. P. de,

synthesis of mica................ 374

Hawes, G. W., alteration of granite........ 589-590

analyses by.............................. 706

chloritization............................ 574

native iron.............................. 312

Hawes, G. W., and Wright, A. W., gases in

quartz........................... 261

Hawkins, J. D. See lies and Hawkins. 

Haworth, E., petroleum...................' 685,702

zinc deposits........................ ^.... 644

Haworth, E., and Bennett, J., native copper. 627 

Hayes, A. A., distribution of vanadium..... 673

sodium iodate in Chilean nitre.......... 243

South American borates................. 237

Hayes, C. W., alunogen deposits............. 247

bauxite................................ 473,474

corrosion of quartz..................... 345,457

iron ores................................. 506

phosphatic sandstones................... 515

phosphorite.............................. 501

Hayes, C. W., and Eckel, E. C., iron ores.... 506

Hayes, C. W., and Kennedy,W., salt deposits. 218 

Texas petroleum........................ 685

Hayes, C. W., and Ulrich, E. 0., phosphorite.. ...................... 501,502

Hayes River, analysis of water.............. 80

Hayhurst, W., and Pring, J. W., ozone in

atmosphere...................... 42

Haywood, J. K., analysis by................. 184

Haywood, J. K., and Smith, B. H., analyses

cited........................... 175,186

Headden, W. P., action of water on orthoclase 457 

alunogen................................ 247

analyses of river waters............... 61,62,76

anthracite............................... 719

barytic sinter........................... 193,553

cubanite................................. 628

natron................................... 231

stannite................................. 052

Heath, G. L., cited.......................... 64

Heazlewoodite............................... 660

Heberdey, P., melilite and gehlenite in slags. 379 

wollastonite in slags..................... 359

Hedburg, E., zinc deposits................... 644

Heddle, M. F., analysis by................... 494

Hedenbergite......:................-...... 359,360

Hedramite.................................. 423

Heider, A., water analysis................... 158

Heileman, W. H., water analyses............ 77

Hein, H., fibrous silica...................... 339

Heintzite.................................. 214,238

Helium, distribution................ 16,300,302,676

in natural gas............................ 683

in spring waters......................... 169

Hell, C., flchtelite.....................'....... 711

Hell, C., and Hagele, C., artificial paraffin... 682 

Helmhacker, R., chromite deposits.......... 666

Hematite.................................. 329,330

Hempel, W., melting points of minerals..... 278,

279,319 

oxygen of the atmosphere................ 41

Henrich, F., cited......................... -202,456

volcanic sublimates...................... 258

Henriet, H., formaldehyde in atmosphere.... 43

Henriet and Bonyssy, ozone................. 42
INDEX. 753

Page. 

Henriot, E., radioactivity.................... 302

Henriot, E., and Varon, G., radioactivity... 302 

Heraeus, W. C., melting points of shales and

clays............................ 278

Herapath, T. J., and W., the Dead Sea...... 157

Herbst, C., ocean water...................... 113

Hercynite................................... 324

Herderite................................... 393

Heron Lake, analysis of water............... 71

Heronite................................... 352,426

Hess, F. L., and Graton, L. C., distribution of

tin............................... 652

Hess, V. F. See Schweidler and Hess.

Hess, W. H., cave nitrates................... 241

Hessite...................................... 622

Hessose.................................... 432,434

Heterogenite................................. 663

Heubachite.................................. 663

Heulandite.................................. 395

Heumite..................................... 423

Heusler, F., formation of hydrocarbons...... 698

Heusser, C., and Claraz, G., Brazilian diamonds.. ......................... 309

Hewett, D. F., vanadium ores............. 073,674

Heycock, C. T., and Neville, F. H., silver

antimonide...................... 621

Heyward, B. H., tallow clays................ 644

Hezner, L., amphibolite..................... 566

eclogite.................................. 573

Hibschite.................................... 391

Hicks, H., phosphatic fossils................. 501

Hidden, W. E., Llano County minerals...... 680

sperrylite................................ 672

xenotime in granite...................... 338

See also Judd and Hidden. 

Hidden, W. E., and Mackintosh, J. B.,

gadolinite, etc................... 680

Hidden, W. E., and Pratt, J. H., sperrylite. 672 

Hidden, W. E., and Warren, C. H., yttrocrasite........................... 680

Hiddenite................................... 360

Hieratite.................................. 257,258

Highwood River, analysis of water.......... 81

Highwoodose................................ 417

Hikutaia Spring, analysis.................... 180

Hilgard, E. W., analyses by............... 150,226

arid and humid soils compared.......... 467

carbonates as solvents of silica........... 459

disintegration of rocks................... 459

origin of alkaline carbonates in soil....... 199,

226,229,230 

soils..................................... 467

Hill, B. F. Terlingua mines.................. 634

Hill, J. B., and MacAlister, D. A., Cornish tin

ores............................. 653

Hill, R. T., salt deposits..................... 218

Terlingua mines......................... 634

Texas petroleum......................... 685

Hillebrand, Sylvia, nephelite............... 353

Hillebrand, W. F., analyses by... 177,178,180,362, 

413,414,415,417,419,421,422,424,427, 

429,430,432,433,435,436,438,439,441, 

442,444,484,509,522,523,524,544,547, 

566,587,588,592,597, 605, 616,675,677 

copper arsenates....................... 631,632

distribution of vanadium................ 673

101381° Bull. 491 11 48

Page.

Hillebrand, W. F., heavy metals in rocks... 601 

kleinite................................. 634

patronite................................ 674

quisqueite............................... 674

rare-earth minerals...................... 680

roscoelite................................ 674

slate..................................... 524

zinc-bearing clay........................ 644

See also Cross and Hillebrand. 

Hillebrand, W. F., and Ransome, F. L.,

carnotite........................ 676

Hillebrand, W. F., and Schaller, W. T.,

Terlingua minerals.............. 634

See also Schaller and Hillebrand. 

Himstedt, F., radioactivity.................. 300

Hinde, G. J., flint and chert................. 519

Hinden, F., dolomite and limestone......... 539

Hiortdahl, T., synthesis of jaipurite......... 661

Hiortdahlite................................. 363

Hirschwald, J., nitrogen compounds in 

rain....................................... 50

Hitchcock, C. H., albertite.................. 688

phosphate rock.......................... 497

steatite.................................. 578

Hobbs, W. H., allaniteandepidotc.......... 387

secondary galena........................ 646

tungsten deposit........................ 668

Hodges, J. F., water analysis................ 85

Hodges, R. S., cited......................... 68

Hogbom, A. G., cited by Arrhenius......... 47

dolomitization......................... 540,541

Hoernes, R. See Doelter and Hoernes.

Hoff. See Van't Hoff.

Hoffmann, E. W., solubility of minerals..... 455

Hoflmann, G. C., analysis by, cited......... 170

baddeckite.............................. 372

native iron.............................. 315

native platinum......................... 669

souesite................................. 314

Hoff man, L., iron ores....................... 549

Hoffmann, R., synthesis of nephelite........ 354

Hofman, H. 0., eutectics in slags............ 288

Hofmann, J. F., formation of coal......... 705,729

Hofmann-Bang, 0., rivers of Sweden........ 94

Hoitsema, S. See Bcmmelen, J. M., van, etc. 

Holland, P., and Dickson, E., decomposition

of diabase....................... 464

Holland, T. H., barite....................... 555

bauxite................................. 475

corundum rock.......................... 322

disintegration of rocks................... 458

graphite in syenite...................... 311

laterite.................................. 469

primary calcite.......................... 397

Holland, T. H., and Christie, W. A. K., the

Sambhar salt lake ............ 139,162

Hollandite.................................. 510

Hollick, A. See Kcmp and Hollick.

Holmes, A., radioactivity................... 302

Holmium.................................. 16,679

Holmquist, P. J., synthesis of perofskite..... 332

Holtz, H. C. See Duparcand Holtz.

Holway, R. S., eclogite...................... 573

Hood, , analysis by...................... 664

Hopeite..................................... 641

Hopkins, A. T., chlorine maps.............. 50
754 INDEX.

Page. 

Hopkins, T. C., limestones.................. 533

Hopmann, H., water analysis............... 162

Hoppe-Seyler, F., formation of marsh gas.... 697

synthesis of dolomite.................... 537

Hornblende........................... 365-367,564

melting point........................... 279

Hornblendite................................ 440

Horner, L., silt.........:.................... 481

Hornstein, F. F., native iron................ 312

Hornung, F., origin of petroleum............ 698

Hornung, M., analysis of red mud........... 489

Hornung, T. See Duparc and Hornung.

Horowitz, J. See Dunin-Wasowicz.

Horsford, E. W., cited...................... 66

Horsfordite................................. 628

Hortonolite................................. 370

Horwood, A. R., calcite and aragonite in

fossils........................... 528

Hoskins, A. P., glauconite................ 493,494

Hovey, E.G., artesian well at Key West.... 543

cordierite gneiss......................... 385

siliceous oolite.......................... 520

How, H., borates of Nova Scotia............ 238

Howard, C, C., natural gas.................. 683

Howard, C. D., analyses by................. 682

Howe, J. L., and Campbell, H. D., on Chichen-Kanab..................... 153

Howlite..................................... 238

Huantajayite............................... 625

Hubbard, P. See Cushman and Hubbard. 

Hiibnerite................................ 667,668

Hudleston, W. H., phosphatic fossils........ 501

Hudson, E. J. See Mabcry and Hudson. 

Hudson River, analyses of water............ 66,98

Hughes, G., phosphate rock................. 497

Hull, E., cited............................... 85

Hull, E., and Hardman, E. T., chert........ 518

Hulsite................................... 652,655

Humboldt and Gay Lussac, cited........... 48

Humboldt Lake, analysis of water........ 148,165

Humboldt River, analysis of water.......... 148

Humboldt salt well, analysis................ 171

Humboldtine............................... 708

Hume, W. F., loess......................... 485

Humphreys, A. A., and Abbot, H. L., sediment of Mississippi River....... 482

Humphreys, W. J., gases in atmosphere..... 41,42

rare earths in fluorite.................... 319

Humus acids................... 98,495,714,715,716

Hundeshagen, L., platinum in wollastonite.. 671 

Hungary, salt and warm lakes of............ 161

Hunt, A. E., bauxite....................... 474

Hunt, T. S., abundance of petroleum........ 703

alteration of siderite..................... 546

analyses by........................ 64,174,187

cosmical atmosphere.................... 52

formation of dolomite............. 535,537,539

on atmospheric carbon dioxide.......... 46

origin of alkaline carbonates............. 229

primeval ocean.......................... 128

salt and gypsum...................... 218-219

sedimentation........................... 482

serpentine............................... 577

See also Logan and Hunt. 

Hunt, W. F. See Kraus and Hunt. 

Hunter, M., analysis by..................... 426

Page. 

Hunter, M., and Rosenbusch, H., monchi- ,

quite............................ 426

Huntilite................................... 621

Hunyadi Janos, origin of water.............. 201

Hurlbut, E. B., analysis by................. 424

Huron, Lake, analysis of water.............. 64'

Hurst, L. F. See Cameron and Hurst.

Hussak, E., associates of diamond........... 309

chalmersite......'....................... 628

leucite pseudomorphs................... 352

native iron.............................. 312

palladium gold.......................... 615

perofskite-magnetite rock............... 332

platinum and palladium.............. 669,671

primary iolite........................... 385

synthesis of wollastonite................ 359

See also Doelter and Hussak. 

Hussak, E., and Prior, G. T., derbylite, etc.. 659 

Hussak, E., and Reitinger, J., monazite sand. 338 

Hutchings, W. M., minerals in sand......... 479

ottrelite................................. 586

willemite in slag........................ 642

Hutchins, W. M., apatite in slag............ 337

clays and shales......................... 524

Hutchinson, , cited..................... 49

Hutchinson, A., Meigen's reaction........... 527

See also Cundell and Hutchinson. 

Hutchinson, brine, analysis of............... 171

Hutton, R. S.' See Pring and Hutton.

Hyalite................................... 339-340

Hyalophane................................. 346

Hyalosiderite............................... 370

Hyalotekite................................. 651

Hydrargillite. See Gibbsite.

Hydroboracite............................ 214,238

Hydrocarbons............................. 681-704

in lava........................ 267,268,269,694

Hydrocernsite.............................. 648

Hydrogen, distribution.:................... 16

in atmosphere........................... 43

Hydrogen dioxide in atmosphere............ 42

Hydrogoethite.........................:.... 504

Hydronephelite........;.................... 395

Hydrozincite................................ 641

Hypersthene.............................. 357,358

I.

Iceland, analysis of geyspr water from........ 185

sinter from....... ...................... 196

Iddiugs, J. P., consanguinity of rocks........ 293

fayalite in rhyolite....................... 371

magnatic differentiation............... 284,294

order of igneous eruptions................ 296

quartz basalt......... .................. 344

rock diagrams........................... 451

See also Barus and Iddings.

Iddings, J. P., and Cross, W., primary allanito............................... 387

Iddings, T. P., and Penfield, S. L., fayalite in

rhyolite.......................... 371

Idocrase. See Vesuvianlte.

Idrialite................................... 637,687

.Igelstrom, L. J., molybdenum in hematite.. 330

Igneous rocks.............................. 398-451

average composition..................... 24-27

classification of........................ 399-411
INDEX. 755

Ihlseng, M. C., phosphate rock.............. 504

Ijolite..................................... 422,423

lies, M. W., and Hawkins, J. D.,precipitated

zinc sulphide.................... 640

Hetsk salt lake, analysis of water.......... 160,162

Uliacus, A. See Ramsay and Illiacus.

Illinois River, analysis of water.............. 72

chlorine in.............................. 100

Wye's Lake, analysis of water.............. 161,162

Dmenite................................... 330-331

Hmenite norite.............................. 444

nosvay, L. von, water analysis.............. 94

Ez, River, analysis of water................. 92

Indalself, analysis of water.................. 94

Indian Ocean............................... 113

Indium, distribution....................... 17,638

Infusorial earth.............................. 520

Ingalls, W. R., tin deposits.................. 654

Ingol, Lake................................. 95

Inn, River, analysis of water................ 92

Inostranzeff, A., native iron................. 315

native platinum......................... 670

schungite................................ 720

d'lnvilliers, E. V., phosphate rock.......... 497

Iodine, distribution......................... 17

in sea water............................. 109

in spring water.......................... 172

lodobromite................................. 625

lolite........................................ 385

Ionian Sea.................................. 112

Ionium...................................... 12,299

Iowa River, analysis of water................ 72

Ippen, J. A., amphibolite................... 566

eclogite.................................. 572

synthesis of cinnabar.................... 636

Iridium............................ 18,315,668-672

Iridosmine................................ 668,670

Irish Sea, analysis of water.................. 112

Iron, distribution........................... 17

hydroxides of......................... 504-508

in sea water............................. Ill

meteoric, chlorides in.................... 129

native................................. 311-315

nitride.................................. 258

occlusion of gases by................... 273,274

Iron bacteria......'.......................... 506

Iron ore............... 327-330,469,504-508,544-550

titaniferous.............................. 444

Irvine, R. See Murray, Sir J.

Irvine, R., and Anderson, W. S., phosphatization........................... 534

Irvine, R., and Gibson, J., manganese nodules............................. 121

Irvine, R., and Young, G., solubility of calcium carbonate.................. 117

Irving, J. D., tin deposits................... 656

Irving, J. D., and Emmons, S. F., tungsten

ores............................. 668

Irving, R. D., native copper................. 626

quartzite................................ 580

Irving, R. D., and Van Hise, C. R., chert... 520 

enlargement of quartz grains............ 514

Isar, River, analysis of water................ 92

Iser, River, analyses of water................ 90

Isere, River, analysis of water............... 86

Isochlors.................................... 50

Page. 

Issyk-Kul, analysis of water............... 160,164

Istrati, C. I., Roumanian salt................ 219

Itabirite..................................... 582

Itacolumite................................. 309

J.

Jaccard, A., origin of petroleum........... 698,702

Jackman, W. F., cited...................... 64

Jackson, D. D.,cited........................ 50

Jacobsen, O., analyses of dissolved air....... 131

analysis of peat......................... 709

resins in peat............................ 711

Jacquot, E., and Willm, E., mineral

springs........................ 199,204

Jaczewski, L., origin of graphite............. 311

Jadeite.................................... 360-362

Jager, F. M., analysis by. ............A...... 507

Jaffa, M. E., alkaline carbonates............. 229

Jaggar, T. A., and Palache, C., zoisite rock... 569 

Jahn, J. J., origin of petroleum.............. 698

Jaipurite.................................. 660,661

James River, analyses of water.............. 67,98

Jamesonite.................................. 647

Jamieson, G. S., nickel-irons................. 314

See also Penfleld and Jamieson. 

Janda, , uranium ores................... 675

Janeirose.................................... 424

Jannasch, P., and Calb, G., composition of

tourmaline...................... 392

Jannasch, P., and Weingarten, P., vesuvianite............................ 383

Jannetaz, E., formation of anglesite.......... 649

Janssen, J., volcanic gases................... 256

Jaqerod, A., and Perrot, F. L., helium...... 304

Jaquet, J. B., platinum in ironstone......... 671

serpentine............................. 394,576

Jarman, J. L., analysis by................... 509'

Jasper....................................... 339

Java, rivers of............................... 96

Jeffersonite................................ 360,641

Jeffrey, E.G., origin of petroleum and coal.. 700,718 

Jenkins, , analysis by................... 509

Jenney, W. P., artificial grahamite.......... 688

recent blende............................ 640

zinc deposits............................ 644

Jennings, E. P., magmatic iron ores......... 328

Jensen, H. I., copper in andesite............. 602

origin of alkaline rocks.................. 423

Jordan, D. S. See Bone and Jerdan.

Jereme'ef, P., chalcopyrite and chalcocite..... 630

pseudomorphous garnet................. 383

pseudomorphs after olivine.............. 371

Jervis, W. P., Tuscan fumaroles............. 239

Jet......................'.................. 712,721

Joannis, A., fusion of limestone.............. 532

Jockamowitz, A., borax..................... 237

Johansson, H. E., eutectics................ 288,402

John, C. von, humus acid in coal............ 714

kainite and carnallite.................... 216

John, W. von, native tantalum.............. 678

Johns, C., transition point of quartz......... 342

Johnson, B. H., and Warren, C. H., cumberlandite.......................... 445

Johnson,H. S.,cited........................ 92

Johnson, J. P.,diamond..................... 308
756 INDEX.

Johnson, L. C., Florida phosphates.......... 497

Johnston, J. See Alien, E. T.

Johnston, R. A. A., analysis by........... 315,326

Johnston-Lavis, H. J., absorption of rocks by

magmas......................... 295

quartz in basalt......................... 285

Vesuvian sublimates.................... 257

Johnstone, A., action of water on micas..... 376

solubility of minerals.................. 121,455

Johnstrup, F., cryolite...................... 319

Joly, J., age of the earth............... 128,138,142

age of minerals.......................... 303

meldometer............................. 278

melting points of minerals............... 279

order of deposition of minerals........... 292

radium and geology..................... 300

radium in sea water................... 112,300

radioactivity and vulcanism............. 302

sedimentation........................... 482

sublimation of enstatite................. 260

thorium in rocks...................... 300,301

volume of oceanic salts.................. 23

volume of oceanic sediments............. 126

Jones, E. J., barite nodules.................. 124

Jones, L. J. W., mine water ................. 604

Jones, T. R., chert.......................... 518

peat..................................... 709

Jonesville acid water, analysis............... 187

Jordan River, analysis of water.............. ' 156

Jordan River (Utah), analysis of water...... 145

Jordanite.................................... 647

Jorissen, A., vanadium in delvauxite........ 673

Joseite...................................... 657

Josephinite................................ 314,660

Joukowsky, E., eclogite..................... 573

Jovitschitsch, M. Z., chromitite............. 326

Jowa, L., synthesis of selenite............. 217,550

Judd, J. W., alteration of plagioclase to scapolite............................ 349,570

atoll of Funafuti........................ 542

corundum rock.......................... 322

origin of scapolite......................... 384

pressure and chemical change........... 277

scapolite rock........................... 570

Judd, J. W., and Brown, C. R., Burmese corundum. ........................ 322-

Judd, J. W., and Hidden, W. E., ruby...... 322

Judge, J. F., and Fennel, A. C., analysis by. 172 

Judithose................................... 420

Jukes Browne, A. J. See Harrison and Jukes

Brown. 

Julien, A. A.,,alteration of spodumene...... 361

decomposition of pyrite................. 318

geological effects of humus acids......... 98,

199,460,519 

phosphate rock.......................... 497

Juvenile waters............................. 201

K.

Kaersutite................................:. 369

Kahlenberg, L., and Lincoln, A. T., hydrolysis of silicates.................. 183

Kahlenberg, L., and Schreiner, O., borate

ions............................. 185

Kainite............................... 212,214,215

Kaiser, E., alteration of basalt............... 476

Page. 

Kaiser, E., decomposition of rocks........... 462

Kalamazoo River, analysis of water......... 65

Kaleczinzky, A., water analysis............. 161

Kalgoorlite.................................. 615

Kaliophilite............................... 353,354

Kalkowsky, E., corrundum granulite........ 322

Kallerudose................................. 415

Kallilite..................................... 660

Kalmann, W., and Glaser, M., analysis by. 173,177 

Kanab Creek, analysis of water from near.... 174

Kansas River, analysis of water............. 74,75

Kaolin.................................... 468,469

Kaolinite.............................. 395,468,584

Kapouran, analysis of water................. 174

Karaboghaz, Gulf..................... 153,154,164

Karlsbrunn, analysis of water from.......... 180

Karlsdorf waters, analysis................... 175

Karstens, K., volume of the ocean........... 22

Kasarnowski, H. See Wohler and Kasarnowski. 

Kaskaskia River, analysis of water.......... 72

Kastle, J. H., Frazer, J. C. W., and Sullivan,

 G., phosphatic chert............ 520

Katamorphism, zone of..................... 558

Katwee salt lake, analysis of water........ 162,165

Katzer, F., analyses of Amazon water....... 83

analyses of sea water cited................ 112

mercury deposits........................ 638

Kauer, A., analysis by...................... 176

Kaufmann, F. G., dopplerite................ 710

Kay, G. F., nickel ores ...................... 663

Kayser, E., carbon dioxide and climate..... 47

Kayser, R., sulphur in petroleum........... 686

Kedabekase................................. 439

Kehoeite.................................... 641

Keith, A., zinc deposits..................... 644

Keller, G., formation of limonite............ 545

Keller, H. F., and Lane, A. C., chloritoid.... 373

Keller, O., volume of ground water.......... 33

Kelly, A., conchite... L...................... 527

Kelvin, Lord, effect of pressure on fusibility. 277 

primitive atmosphere................... 53

Kelyphitei...........!...................... 382

Kemp, J. F., bornite in pegmatite......... 629,630

Franklin zinc ores....................... 645

gneiss denned........................... 591

gravitative differentiation in magmas.... 297

iron ores................................ 445

magmatic magnetite.................... 328

metamorphosed dolomite................ 596

mol y bdenite in pegmatite............... 318

nickel ores.............................. 662

ore deposits........................... 599,607

platinum ores............. 315,669,670,671,672

relative abundance of elements.......... 27

secondary enrichment.................... 611

tellurides.............................. 615,616

Kemp, J. F., and Hollick, A., limestone..... 596

Kempton, C. W., tin deposits............... 654

Kendall, P. F., calcite and aragonite in shells. 528 

Kennedy, W. See Hayes and Kennedy. 

Kennedy, W. T. See McLennan and Kennedy.

Kenngott, A., alkaline reaction of minerals.. 454 

composition of tourmaline............... 392

vesuvianite............................. 383
INDEX. 757

Page. 

.Kenrick, F. B. See Van't Hofl, Kenrick, and

Dawson. 

Kentallenose................................ 433

Kentrolite................................... 651

Kentucky River, analysis of water.......... 73

Kermesite................................... 657

Kern-theorle................................ 404

Kerner, G., water analysis.................. 89

Kerosene shale.............................. 700

Kerr, W. C.,marl........................... 526

Kersantite................................ 418,433

Kettner, C. H., analysis by.................. 507

Keyes, C. R., borax deposits................ 234

genesis lead and zinc ores................ 644

gypsum................................. 550

linnseite................................. 662

loess.................................... 485

ore deposits........................... 599,644

origin of cerargyrite..................... 625

primary epidote......................... 386

recent blende............................ 640

ultimate source of ores................... 600

Kicserito...................... 212,213,214,216,217

Kikuch i, , occurrence of iolite............ 385

Kilbrickenite................................ 647

Kllroe, J. R.,lateriteand bauxite............ 470

Kimball, J. P., grahamite................... 688

iron ores............................... 506,545

Kimberlite.................................. 309

Kinahan, G. H.,bauxite.................... 473

Kinch, E., sodium chloride in rain........... 50

King, C., internal temperature of the earth.. 277 

King, F. P., Georgia corundum.............. 322

Kingsbury, J. T., waters of Utah............ 144

Kirk, M. P., and Malcolmson, J. W., Terlingua minerals.................. 634

Kirunose.................................... 445

Kisil-Kul, analysis of water................ 159,163

saline deposits........................... 222

Kitchell, W., marl........................... 526

Kitchin, E. 3., and Winterson, W. G., argon

and helium in minerals.......... 261

Klaprotholite................................ 631

Klarelf, analysis of water..................... 94

Klarfeld, H. See Zaloziecki and Klarfeld. 

Kleinito..................................... 634

Klement, C., analyses by.................. 123,587

formation of dolomite_............... 537,542

. laterite.................................. 470

origin of petroleum...................... 697

Klementite.................................. 377

Klemm, G., minerals in sandstone........... 516

Klobbio, E. A., analys'is by.................. 507

See also Bemmelen, J. M. van, etc. 

Knebelite................................... 370

Knight, C. W., analcite trachyte............. 352

See also Campbell and Knight. 

Knight, H. G., water analyses.............. 78,151

Knight, W. C., platinum in covellite........ 672

Knisely, A. L., water analyses............... 78

Knop, A., enlargement of quartz grains...... 514

Knopf, A., Alaska tin deposits.............. 655

Knopf, A., and Schaller, W. T., hulsite and

paigeite ......................... 652

Knoxvillite.................................. 665

Kobellite.................................... 647

Page. 

Koch, A., celestite and barite................ 553

Kochelsee, analysis of water................. 88

Kb'brich, bauxite............................ 473

Kohn, E.,cited............................. 92

Koene, C. J., primitive atmosphere.......... 53

Koenig, A., genesis of diamond.............. 310

Koenig, G. A., analysis cited................ 174

synthesis of domeykite.................. 628

Koenig, G. A., and Foote, A. E., diamonds

in meteorite..................... 308

Konig, T., and Pfordten, 0. von der, ilmenite. 331 

Koenigsberger, J., radioactivity.............. 302

Konigsberger, J., and Miiller, W. J., synthesis of quartz and tridymite... 340 

Konigsee, analysis of water.................. 88

Konlite...................................... 687.

Kottigite.................................... 641

Koettstorfer, J., iodine in sea water.......... 109

Kohlmann, W., associates of cassi terite...... 335

Kohlrausch, F., hydrolysis of silicates....... 183

Koken, E., carbon dioxide and climate...... 47

Koko-Nor, analysis of water............... 158,165

Kolenko, B., hornblende pseudomorphs... 360,371 

Kolderup, C. F., analysis by................. 444

Kolkwitz, R., and Ehrlich, F., on the Elbe.. 90 

Kolotofl, S., analysis of sea water............ 114

Koninck, L. L. de, synthesis of cinnabar..... 636

Koninckite.................................. 496

Kornerupine.............................. 362,584

Kosmann, H. B., silver halides.............. 625

Koto, B., chloritoid rock.................... 586

glaucophane rocks....................... 565

piedmontite............................. 387

Kovaf, J., kyanite in limestone.............. 390

Kriimer, G., and Bottcher, W., origin of petroleum ......................... 697

Kramer, G., and Spilker, A., origin ofpetro--

leum............................ 701

Kraus, E. H.,celestite....................... 552

Kraus, E. H., and Hunt,-W. F.,celestite.... 552

Kraut, K., diffusion of cobalt and nickel..... 660

Kraze, K., Stassfurt salts.................... 211

Kremersite.................................. 258

Krennerite.................................. 016

Kretschmer, A., composition of fahlerz....... 631

Kreusler, U., oxygen of the atmosphere...... 41

Kreutz, S., amphibole....................... 367

the Meigen reaction_................... 527

Krogh, A., annual consumption of coal....... 45

oceanic carbonic acid.................... 134

airfrom Greenland....................... 45

Kruft, L.,phosphorite...................... 500

Krugite..................................... 212

Krypton................................ 17,40,169

Kryptotile................................. 374,584

Ktypeite.................................... 627

Kiimmel, H. B., clays....................... 484

peat..................................... 709

Kuhlmann, F., silication of limestone........ 534

synthesis of cerargyrite................... 625

Kulaite...................................... 436

Kultascheff, N. V., fusion of mixed silicates.. 286 

Kunz, G. F., Montana corundum............ 323

Kum, G. F., and Washington, H. S.,Arkansas diamonds.................... 309

Kunzite..................................... 360
758 INDEX.

Kurnakoff, N.S.,ou Karaboghaz............ 154

Kurtz, C. M., analyses by.................... 232

Kusnetsoff, S., on Karaboghaz ............... 154

Kuss, H., mercury deposits.................. 638

Kvassay,E.von,origin of alkaline carbonates. 229 

Kyanite........................... 389,390,584,585

Kyanite schist............................... 587

Kyle, .T. J., Argentine borates............... 237

vanadium in lignite...................... 673

water analyses.......................... 83

Kyschtymase............................... 444

Kyschtymite..._........................ 322,444

L.

Laabitter spring, analysis................... 176

Laach, Lake, analysis of water............ 161,164

Laborde, A. See Curie and Laborde. 

Labradorite................................. 346

Laby, T. H. See Mawson and Laby.

Lachat, , celestite........................ 553

Lachaud and Lepierre, lead chromates....... 650

Lachmann.'R., laterite ...................... 473

Lacroix, A., absorption of limestone by granite.............................. 295

allanite and epido te...................... 387

alteration of bronze..:................. 629,632

alteration of hornblende to augite...:.... 366

alteration of serpentine................ 394,577

berthierine.............................. 549

boric acid in fumaroles................... 233

chalcocite on old coins.................... 629

constitution of phosphorite............... 499

dumortierite in gneiss ................... 391

eclogite rocks.......................... 572-573

formation of zeolites...................... 396

glauconite............................... 493

ktypeite................................. 527

minervite............................... 498

Mont Pelee.............................. ' 255

occurrence of lawsonite................... 391

phosphates of lime....................... 499

phosphatizedandesite................... 497

recent cerussite.......................... 648

scapolite rocks......................... 384,571

spinel in troctolite....................... 326

tridymite............................... 344

villiaumite.............................. 354

volcanic sublimates................ 255,257,258

See also Michel LeVy and Lacroix. 

Lacroix, A., and Baret, 0., werneriterock.... 571

Lacroix, A., and de Schulten, A., Laurium

slag minerals.................... 649

Lacu Sarat, analysis of water............... 161,163

saline deposits........................... 222

Laczczynski, , analysis of chromite..... 326,665

Ladd, G.E.,clays........................... 484

Ladureau, A., sulphur in atmosphere......... 44

Lagonite.................................... 232

Lagorio, A., eutectics........................ 401

formation of leucite...................... 351

fusibility and solubility distinguished.... 293

glass-base............................... 294

pyrogenic corundum.................. 321,322

solubility of minerals in magmas......... 295

Lagoriolite.................................. 381

Page. 

Lahille, F., analysis of sea water.............. 112

Lahontan, Lake... L ......................... 146

LaiD§, E. See Muntz and Laine.

La Junta artesian well, analysis.............. 180

Lake, P., laterite.......................... 469,470

Lampadite........;........................ 509,632

Lamprophyre............................. 418,419

Lanarkite.................................... 649

Lane, A. C., criticism of Brun............... 270

eutectics............................... 288,402

magmatic gases........................ 270,271

mine waters........................... 174,604

native copper.;........................... 626

theocean................................ 116

volcanism............................ 270,271

waters of Michigan...................... 65,201

See also Keller and Lane.

Lane, A. C., and Sharpless, F. F., griinerite... 364 

Lang, J., bauxite............................ 473

Langbeinite..... f ......................... 212,216

Lansfordite.................................. 538

Lanthanum...........................^.... 17,679

Lapis lazuli.................................. 355

Lapparent, A', de, distribution of solfataras.. 201 

Laramie lakes, analyses of water............ 152,163

Laramie River, analyses of water............. 74

Larderellite................................. 232

Larsen, E. S. See Wright and Larsen.

Lartet, L., on Dead Sea.................... 157,536

Lasaulx, A. von, alteration of rutile.......... 331

kelyphite................................ 382

sulphur deposits......................... 551

See also Sartorius and Lasaulx. 

Lasne, H.,phosphorite...................... 504

Laspeyres, H., olivine as a furnace product.. 370 

sericite.................................. 567

Lassenose..... J........................... 413,430

Lateral secretion.......................... 600,601

Laterite.......1....................... 469-477,510

Latite........................... 1........... 428

Latschinoff, P. See Erofe'ef and Latschinoff. 

Lattermann, G., barytic sinter.............. 554

Lattimore, S. A.,analysist>y................ 223

Laubanite................................... 395

Laumontite................................. 395

Launay, L. De, average composition of

igneous rock..................... 26

. diamond................................ 308

magmatic waters...................... 202,606

mean atomic weight of lithosphere...... 26

ore deposits....................... 599,606,610

Laur, F., bauxite........................... 472

gold and silver in Triassic rocks......... 613

Laurdalite........................ 1......... 423

Laurdalose................................ 419,420

Laurionite.................................. 649

Laurite..................................... 668

Laurvikose.................................. 416

Lautarite................................... 243

Lavenite.................................... 363

Lawrenceite................................. 129

Lawson, A. C., chert........................ 519

corundum rock.......................... 322

mine water............;................. 604

See also Adams and Lawson. 

Lawson, A. C., and Palache, C., chert....... 519
INDEX. 759

Page. 

Lawsonlte.. .\............................... 391

Lead, distribution........................... 17

occurrence in a coral..................... Ill

ores of.................................. 645-052

Leadhillite.................................. 049

Lebedintzeff, A., water analyses............. 154

. Leblanc, F. See Deville and Leblanc. 

Lechartier, G., synthesis of raimetite........ 051

syntheses of olivine.,.................... 370

synthesis of pyroxene................... 300

I/e Chatelier, H., Algerian alkaline deposits.. 229 

clay substances in marl.................. 534

constitution of clay silicates............. 469

formation of granite..................... 412

fusion of limestone...................... 532.

thermo-couple........................... 277

Lechler, M., Bavarian waters ............... 92

Leckie, J. S., nickel ores..................... 004

Le Conte, J., Nevadaborates................ 234

Le Conte, J., and Rising, W. B., mercury

deposits......-....-------------- G38

Leddln, . See Blum.

Ledoux, A. R., nickel ores.................. 603

Leduc, A., hydrogen in atmosphere......... 43

Lee, G. W. See Collet and Lee.

Lee, W. T., Cove Creek sulphur............. 552

Leftaian, H., waters of Yellowstone Park.... 185

Lefort, J., analysis by....................... 189

Legendre, R., carbon dioxide in air.......... 45

Leguizamon, M. M., water analysis.......... 153

Lehder, J., phosphatic nodules.............. 504

Lehrbachito............................... 634,645

Lehmann, B., sericitic rocks................. 567

Lehmann, T. See Engler and Lehmann. 

Leibius. A., gold............................ 615

Leighton, H. See Newland and Leighton. 

Leighton, M. 0., analysis of water........... 65

normal and polluted waters............. 100

Leith, C. K., actinolite-magnetito schist..... 305

glauconite and greenalite.............. 493,547

origin of magnetite...................... 329

Leith, C. K., and Mead, W. J., iron ores..... 506

Leitmeier, H., dimorphism of calcium carbonate .......................... 527

spring deposits........................ 193,538

Lekene...................................... 686

Leman, Lac, analysis of water............... 86

Lemberg, J., alterations of feldspar.......... 349

alteration of spodumene and jadeite..... 361

of topaz............................. ' 388

artificial cancrinite...................... 356

chlorito pseudomorphs................ 378,382

composition of sodalite................ 355,356

decomposition of rocks.................. 462

double decompositions in silicates....... 477

epidotization............................ 572

fusion of limestone...................... 532

kaliophilite and nephelite............... 353

leucite and analcite.................... 350,351

predazzite............................... 544

primitive atmosphere................... 53

reactions with andalusite and kyanite... 390 

with gehlenito....................... 380

serpentine............................. 575,576

silicution of limestones.................. 534

syntheses of zeolites..................... 396

Page.

Lemberg, J., tests for calcite and dolomite... 539 

Lome" tayer, P., water analysis............... 84

Lemiere, L., formation of coal............... 729

Lemoine, P. See Chautard and Lemoine. 

Lenar6i6, J., formation of augite............. 363

formation of magnetite.................. 328

of nephelite.......................... 354

fusion of mineral mixtures............... 291

recrystallization of albite................ 347

Lenecek, 0., predazzite...................... 544

Lengenbachite.............................. 647

Lengyel, B. von, analysis of water........... 101

Lenher, V., gold telluride.................. 616,619

solution of gold.......................... 618

See also Hall and Lenher. 

Lenicque, H., carbide theory of volcanism... 267

origin of petroleum...................... 696

primitive atmosphere.................... 54

Lenk, H., augite-scapolite rock.............. 384

Lenz, 0., itabirite........................... 582

Lenz, R., laterite............................ 470

Leonard, A. G., gas well..................... 090

zinc deposits............................. 644

Leonite...................................... 212

Lepidolite............................. 372-370,655

Lepidomelane............................... 373

Lepidophaeite .............................. 509

Lepierre, C., fluorine in spring waters........ 180

Lepsius, B., composition of dissolved air..... 453

Lepsius, R., glaucophane schists............. 505

Lermondose................................. 443

Lesley, J. P., grahamito..................... 088

Lesquereux, L., origin of petroleum......... 700

Letheby, H., water analyses................. 97

Letts, E. A., and Blake, R. J., carbon dioxide

in air............................ 44

Leube, G., dolomite......................... 540

Leucite.................................... 350-352

melting point............................ 279

Leucite basalt............................... 430

Leucito rocks.............................. 424,425

Leucite syenite.............................. 424

Leucitite.................................... 424

Leucopyrite................................. 050

Leucoxene................ 1................. 331

Leuk, analysis of water...................... 170

Levat, E. D., gold and silver in diabase..... 602

nickel ores............................... 604

phosphate rock.......................... 502

Leverett, F., loess........................... 485

Leverrierito............................... 374,584

Levi, M. G., radioactivity of lava............ 301

Levin, M., decay of uranium................ 304

Levin, M., and Ruer, R., radioactivity.... 300,302

Levison, W. G., decomposition of rocks.... 453,450

Levy. See Michel-Levy; Fouqud and MichelLe'vy. 

Levy, A., nitrogen compounds in rain....... 49

Levyuite.................................... 395

Lewin, L. See Schweinfurth and Lewin.

Lewis, H. C., origin of diamond............. 308

Lewis, J. V., North Carolina corundum...... 322

See also Pratt and Lewis. 

Lewisite..................................... 659

Lewy, H., analysis by....................... 188

Lherzollte................................. 440,441
760 INDEX.

Page. 

Libbey, W., volcanic gases.................. 256

Liebenow, C., radioactivity.................. 301

Lieber, 0. M., itabirite...................... 582

Liebert, H., uranium in coal................. 678

Liebisch, T., silver antimonides............. 621

Liebrich, A., bauxite...................... 473,477

Lienau, H.,bauxite......................... 475

Lignin....................................... 706

Lignite.................................... 711-716

Lignocellulose............................... 706

Lignone..................................... 706

Lillianite.................................... 647

Limburgite, fusibility....................... 282

Limbu'rgose................................. 436

Limestone......................... 524-534,593-597

average composition..................... 28,31

formation of........................... 118,119

Limnite..................................... 504

Limonite.............................. 504-508,546

Linarite..................................... 649

Linck, G., associates of spinel................ 325

oolite.................................... 529

origin of dolomite........................ 536

orthoclase in dolomite................... 595

solubility of calcium carbonate.......... 118

troilite................................... 316

Lincoln, A. T. See Kahlenberg, L.

Lincoln, F. C., gold......................... 617

magmatic gases.......................... 276

Lindemann, B., minerals in limestone....... 596

Lindgren, W., analcite in rocks.............. 352

brochantite............................ 632,633

chalcocite............................... 630

fluorite in sinter......................... 193

magmatic magnetite..................... 328

magmatic waters as vein fillers.......... 202

monazite sand........................... 339

native copper............................ 626

Ojo caliente............................. 180

ore deposits.......... 1.................. 607

orthoclase as a gangue mineral........... 349

pseudomorphous galena................. 646

sericite and calcite....................... 568

sodalite syenite.................... 352,357,426

stibnite in sinter......................... 658

tin deposits.............................. 655

tungsten ores............................ 668

Lindgren, W., and Hillebrand, W. F., coronadite..... ........................ 510

Linnseite.................................... 660

Linosite..................................... 369

Liparite..................................... 412

Liparose............................... 413,415,449

Lipp, A., analysis by........................ 173

Lisboa, A., monazite sand................... 338

Litchfieldite............................... 422,423

Lithium, distribution....................... 17

in sea water..................'........... 110

Lithosphere, average composition............ 24-32

volume of............................... 22

Little, G., lead selenide...................... 645

Little, O. H. See Cole and Little.

Liveing, G. D., cited........................ 43

Liversidge, A., analyses by............ 174,663,664

bog-iron ore............................. 508

cobalt ores............................... 663

Page. 

Liversidge, A., coral......................... 531

distribution of silver..................... 619

gold in recent pyrite..................... 617

in sea water......................... Ill

in rock salt.......................... 613

mercury in sinter........................ 638

precipitation of gold..................... 619

silver in sea water....................... Ill

solvents of gold.......................... 617

Livingstonite.....'..................... 634,636,658

Ljubavin, N., cave earth.................... 241

Ljusnan, River, analysis of water............ 94

Loch Baile a' Ghobain, analysis of water.... 85

Locke, J. M., uintaite........................ 687

Lockyer, J. N., cited........................ 12

Loebisch, W., and Sipo'cz, L., water analysis. 114 

Lollingite.................................. 318,656

Loess...................................... 485-487

Loew, 0., analyses by................. 145,150,224

Loewe, L., cited, on Stassf urt salts.......... 210

Lowenstein, H., clays....................... 477

Loewinson-Lessing F., average composition

of igneous rocks.................. 26

classification of igneous rocks............. 403

eutectics................................. 402

fractional crystallization................. 297

magmatic differentiation.......... 284,294,295

origin of volcanic gases................... 267

relative abundance of minerals........... 291

solubility of minerals in magmas......... 297

Loewite................................... 212,217

Logan, W. E., and Hunt, T. S., phosp'hatic

shell............................. 500

Lohmann, P., eclogite....................... 573

Loire, River, analysis of water............... 86

Long, J. H., cited........................... 64

Longbanite.................................. 659

Lorandite................................... 656

Lord, E. C. E., analysis by.................. 439

Lorenz, N. von, water analysis.............. 88

Lorenz, R., synthesis of greenockite and

wurtzite......................... 639

synthesis of troilite...................... 316

Lorenzen, J., graphite in basalt............ 311,312

Loretz, H., iron ores......................... 549

Losanitsch, S. M., chromiferous clays........ 665

Lessen, C., itabirite.......................... 582

quartzite................................ 580

Lossen, K. A., albite alterations............. 568

Lossetiite.................................... 651

Lossier, L., water analyses................... 86

Lost River, analysis of water................ 78

Lotti, B., copper ores........................ 629

stibnite and cinnabar.................... 658

Louderback, G. D., radioactivity and volcanism.......................... 302

Loughlin, G. F.,clays....................... 484

Louisville artesian well, analysis............. 175

Lozinski, V. von, chemical denudation...... 137

Luca, S. de, analysis by..................... 188

Lucas, A., chemistry of the Nile............. 96

Lucas, R., physical properties of clays....... 478

Ludlamite................................... 4%

Ludwig, A., artificial diamond.............. 307

Ludwig, E., analysis by.................... 177,180

Ludwig, F., analyses by................ 95,158,222
INDEX. 761

Page. 

Ludwig, F. J. H., analysis by............... 194

Luedocke, 0., water of the Oder............. 94

Luedeking, C., lead chromates............... 050

Luedeking, C., and Wheeler, H. A., barite... 554 

Lujavrose................................... 420

Lunge, G., cited, on Stassfurt salts.......... 210

natural soda............................. 227

Lunge, G., and Millberg, C., solubility of

quartz........................... 345

Lunge, G., and Schmidt, E. E., analysis by.. 176 

Lunn, A. C., internal temperature of the

earth............................ 277

Lunquitz, E. E., gold sands................. 619

Lupton, N. T., analysis of water, cited....... 72

Lutecite..................................... 339

Lutecium.................................. 21,679

Luzi, W., corrosion of diamond.............. 309

formation of graphite.................... 310

Lyell, C., precipitated calcium carbonate.... 525

Lyons, A. B., copper in lava................. 602

Soils..................................... 484

M.

Mabery, C. F., natural gas................... 683

petroleum................. 682,684,685,686,697

See also Robinson, A. E. 

Mabery, C. F., and Byerly, J. H., byerlite.... 689

Mabery, C. F., and Hudson, E. J., petroleum 684,685 

Mabery, C. F., and Palm, 0. H., Ohio petroleum ............................ 685

Mabery, C. F., and Quayle, W. O., petroleum. ......................... 684,686

Mabery, C. F., and Smith, A. W., Lima oil.... 686

Mabery, C. F., and Takano, S., Japanese petroleum. ........................ 684

MacAlister, D. A See Hill and MacAlister. 

Macallum, A. B., cited...................... 116

MacBride, T. H., peat....................... 711

McCaleb, J F., cited........................ 216

McCalley, H., bauxite....................... 473

McCallie, S. W., iron ores.................. 506,579

limestones............................... 533

phosphate rock.......................... 504

waters of Georgia........................ 58

McCaughey, W. J., solubility of gold.......... 618

McClelland well, analysis.................... 180

McConnell, W., gases in coal............... 725,726

McOourt, W. E., and Parmelce, C. W., peat... 711 

McCreath, A. S., coal analyses................ 719

Mac6, , synthesis of angles! te............. '649

Macfarlane, W., See Ebaughand Macfarlane. 

McGee, W J, bitumens....................... 702

laterite.................................. 470

loess..................................... 485

Mcllheney, P. C., solvent of gold............ 617

Mclntosh, D. See Eve, A. S.

Mclvor, R. W. E., guano phosphates......... 496

maldonite............................... 615

McKee, R. H., mass of atmosphere........... 52

Mackie, W., allanite in granite................ 387

analyses of clays......................... 483

analyses of sand......................... 480

calcium fluoride as cement............... 515

on age of the earth....................... 137

sandstones............................... 517

Page.

Mackintosh, J. B. See Hidden and Mackintosh. 

Mackintosh! te............................... 680

Maclaren, J. N., gold and silver in sinter.... 196,617

hot springs of New Zealand.............. 202

Maclaren, M., laterite........................ 470

Maclaurin, J. S., cited, on New Zealand

spring waters.......... 185,189,196,202

McLennan, J. C., and Kennedy, W. T., radioactivity. ........................ 302

McNairn, W. H., apatite.................... 499

Macomb deep well, analysis of water......... 182

Mactear, J., mercury ores.................... 634

Madupite.................................... 424

Madupose................................... 424

Maey, E., silver antimonide................. 621

Magma, temperature of.................... 277-282

Magmatic assimilation..................... 294,295

Magmatic differentiation.............. 284,293-298

Magmatic dissociation..................... 284-286

Magmatic solutions........................ 283-286

Magmatic stoping........................... 295

Magmatic waters............................ 606

Magdeburgose......................... 412,414,415

Magnesioferrite.............................. 324

Magnesite................................. 397,539

Magnesium, distribution..................... 17

Magnenat and Wooten, analyses by.......... 714

Magnetite............................. 324,327-329

melting point............................ 279

Magnetite spinellite.......................... 444

Magnetite syenite............................ 445

Magnochromite.............................. 665

Mahanuddy River........................... 96

Mahler, 0., calcite and dolomite............ 537,539

Main, River, analysis of water............... 89

Majorana, Q., diamond...................... 307

Makin, C. J. S., analysis of sea water........ 112

Malachite.................................... 632

Malacca, Straits of........................... 113

Malbot, H., and A. phosphorite.............. 501

Malcolmson, J. W. See Kirk and Malcolmson. 

Maldonite................................... 615

Malignose................................... 422

Malkomesius, P., and Albert R., Cassel

brown....................... v 715,716

Mallard, E., cristobalite..................... 339

lead oxychlorides........................ 649

Mallet, F. R., Indian corundum............. 322

laterite.................................. 470

lateritic manganese...................... 510

on langbeinite........................... 213

Mallet, J. W., allanite....................... 679

analysis by.............................. 196

gases from meteorites.................... 273

silver in volcanic ash.................. 258,601

Maltha...................................... 688

Mangandolomite............................. 547

Manganese, distribution..................... 17

in sea water............................. Ill

ores of................................. 508-512

Manganese nodules......................... 121,508

Manganite................................... 508

Manganosite................................. 508

Manltoulin Island, analysis of water from..... 174
762 INDEX.

Page. 

Manjak...................................... 688

Manley, J. J. See Giinther, R. T.

Mann, P., alteration of titanite.............. 333

constitution of pyroxenes................ 364

Manross.N. S., asphalt...................... 688

synthesis of apatite...................... 337

of lead ores........................ 649-651

of scheelite.......................... 667

Marcano, V. See Muntz, A.

Marcasite.................................... 318

Marck, W. von der, analysis of sandstone.... 515

Marckwald, W., radioactivity............... 304

uranium ores............................ 675

Marcus, E., and Biltz, W., Stassfurt salt

clay........................... 211,673

See also Biltz and Marcus. 

Marcusson, J., artificial petroleum....:...... 698

origin of petroleum.................... 698,703

optical activity of petroleum............. 703

Mare Morto, analysis of water................ 113

Margarite.................................... 373

Margarodite.................................. 372

Margottet, J., reduction of silver sulphide.... 620

synthesis of argentite.................... 621

See also Hautefeuille and Margottet. 

Marialite.................................. 383,571

Maricose............... 1..................... 441

Marienquelle, analysis of water.............. 173

Marignac, C. de, synthesis of dolomite....... 535

Marigny, F. D., Algerian waters............. 62

synthesis of chalcopyrite................. 628

synthesis of galena....................... 645

Marl....................................... 526,541

Marmora, Sea of, analysis of water........... 113

Marsden, R. S., artificial diamond........... 307

formation of crystalline silica............ 341

Marsh, gas................................. 696,698

Marshite..................................... 632

Marsilly,. , analysis of peat............... 709

Martens, P., Chilean thermal waters......... 240

Martin, K., phosphate rock.................. 497

Martin, W. J., platinum ores................ 669

Martinite.................................... 496

Masing, E., synthesis of anglesite............ 049

Mason, W. P., analysis by................... 180

Massicot..................................... 647

Massol, G., helium in spring water........... 169

Matthews, E. B., classification of rocks...... 411

Matildite.................................. 623,624

Matlockite................................... 648

Matteucci, R. V., volcanic ammonium chloride ...... ; ...................... 259

Matthew, W. D., phosphatic nodules........ 501

Maumee River, analysis of water............ 65,98

Maumen6, E.,manganeseinseaweeds....... Ill

Mauritz, B., synthetic wollastonite.......... 359

Mauzeliite................'................... 659

Mawson, D., carnotite....................... 677

Mawson, D., and Cooke, W. T., phosphates

from guano...................... 498

Mawson, D., and Laby, T. H., radioactivity

of minerals...................... 300

Maxwell, W., Hawaiian lavas and soils...... 469,

470,475,484 

Mayencon, , artificial galena............. 646

sulphides formed in burning coal mine... 657

Page.

Mayr, F. See Simmersbach and Mayr. 

Mayrhofer, J., cited.......................... 92

Mead, W. J., relative proportions of sedimentary rocks....................... 31

Meadows, T. C., and Brown, L., phosphorite. 501 

Mecca, holy well at, analysis of water........ 186

Mediterranean Sea, analysis of water....... 113,208

Medve Lake................................. 161

Mehu, M. C., synthesis of cinnabar.......... 635

Meigen, W., calcite and aragonite............ 528

calcium carbonate as precipitant of

metals......................... 527,612

dolomite................................. 536

Meionite............................... 383,384,571

Melanite..................................... 381

Melanochroite............................... 650

Melanotekite................................ 65

Meldometer................................. 278

Meldrum, R., solubility of copper............ 626

Melilite.................................... 378-380

Mellite...................................... 708

Mellor, J. W., clay silicates.................. 584

Meionite..................................... 660

Melting points of minerals................... 279

Melvill, E. H. V., diamonds................. 309

Melville, W. H., analyses by.............. 150,175,

186,314,427,517,522,566,579,583,658 

glaucophane rock........................ 565

josephinite.............................. 314

Menaccanite................................. 330

Mendeteef, D., origin of petroleum........... 694

periodic classification.................... 36

Mendipite................................... 648

Meneghinite................................. 647

Mennell, F. P., average composition of igneous rock......................... 26

laterite.................................. 470

Mercury, distribution........................ 18

ores of................................. 633-638

Merensky, H., diamonds.................... 309

Merian, A., constitution of pyroxenes........ 364

Merivale, W., manjak....................... 688

Merrill, F. J. H., gypsum.................... 550

Merrill, G. P., analyses by.................... 464

asbestos................................. 364

cave gypsum............................ 217

disintegration of rocks................... 457,

458,462,463,465,466,467 

gold in granite......................... 316,613

meteorites............................... 39

onyx marble............................. 524

serpentine............................. 575,576

Merrill, J. A.,flint........................... 519

Merrimac River, analysis of water........... 66

Merz, C., water analysis..................... 89

Mesitite................................... 397,545

Mesolite..................................... 395

Metabrushite................................ 496

Metachlorite.... ............................ 377

Metacinnabarite....................... 634,635,637

Metallic ores............................... 599-680

Metamorphic rocks........................ 557-598

Metastibnite................................. 657

Meteorites, average composition............. 38,39

diamonds in............................. 308

gases from............................... 273
INDEX. 763

Page. 

Meteorites, hydrocarbons in.:............... 695

Metzger, C., water analysis.................. 92

Meunier, S., analysis by..................... 174

bauxite................................. 472

carbon in meteorite...................... 695

composition of fossil plants.............. 717

origin of petroleum...................... 694

of platinum......................... 671

planetary atmospheres.................. 53

synthesis of anorthite.................... 346

synthesis of brochantite................. 633

of chromite........................ 326,666

of enstatite.......................... 358

ofleucite............................ 350

of nephelite......................... 354

of olivine............................ 371

of phoenicochroite................... 650

of spinel............................. 325

of tridymite......................... 341

tin in sinter........................... 195,653

troilite.................................. 316

volcanic explosions....................... 283

See also Daubrfie and Meunier. 

Meuse, River, analysis of water............. 86

Mexico, Gulf of.............................. 113

Meyer, E., von, gases in coal................ 725

Meyer, 0., calcite and dolomite.............. 539

Meyerhoffer, W., phase rule................. 290

See also Van't Hoff and Meyerhoffer. 

Miami River, analysis of water.............. 72

Miargyrite................................ 623,624

Miaskose.................................. 420,426

Micas..................................... 372-376

Mica schist................................ 587-591

Michael, P., saussurite gabbro............... 569

Michel, L., bismuth in molybdenite......... 667

synthesis of azurite...................... 633

of lead ores.......................... 651

of melanite.......................... 382

of minium and plattnerite........... 647

of powellite.......................... 666

of rutile............................. 333

of titanite.............. j............ 332

of tungsten minerals............... 667,668

Michel-Le'vy, A., magmatic differentiation .. 295 

minerals in sand......................... 479

primary epidote......................... 387

quantitative classification............... 411

scapolite gabbro......................... 570

Miche!-L6vy, A., and Lacroix, A., envelopment of allanite................. 387

Michel-Le'vy, A., and Munier-Chalmas, E.,

chalcedony...................... 339

Michigan, waters of.......................... 65

Michigan, Lake, analysis of water........... 64

Microcline................................... 345

Micrometric analysis of rocks................ 450

Microorganisms in coal formation............ 729

Micropegmatite, as an eutectic.............. 288

Mlcrosommite.............................. 355

Middlemiss, C. S., Indian corundum........ 322

Miersite..................................... 625

Mikhailovsky, G. P., origin of naphtha...... 702

Miklucho-Maclay, M. von, occurrence of cassiterite.......................... 335

Milch, L., glaucophane rocks................ 665 I

Page. 

Milch, L., quantitative classification........ 411

Millar, C. C. H., phosphates................. 501

Millberg, C. See Lunge and Millberg.

Millelacs Lake, analysis of water............. 71

Miller, A.M., phosphatic fossils............. 500

Miller, N. H. J., composition of rain water. 44,49,50 

Miller, W. G., cobalt ores.............. 660,661,662

corundum anorthosite................... 322

limestone............................... 533

nickel in magnetite...................... 327

Millerite............................... 660,601,662

Mills, J. E., geological work of ants.......... 461

Milosin...................................... 665

Mimetite.................................... 650

Minervite................................. 497,498

Minette................................... 418,419

Minette (iron ore)........................... 549

Mine waters........................... 178,604,605

Mineral waters, classification...... 162-165,169,170

Mingaye, J. C. H., analysis by................ 182

cave phosphates......................... 498

mine water. .............................. 604

platinum................................ 672

vanadium in clay....................... 673

Minium..................................... 647

Minnesota River,analysis of water.......... 71

Minnetonka, Lake, analysis of water........ 71

Minor, J. C. See Penfield and Minor. 

Minssen, H., and Tacke, B., solubility of

calcium phosphate............ 495

Mirabilite......................... 216,222,237,243 '

Mispickel.................................... 656

Missouri River, analyses of water............. 74

Missourite................................... 424

Mississippi River, analyses of water.......... 70

chlorine in.............................. 100

flow of.................................. 71

sedimentation in........................ 482

Mittagong chalybeate spring, analysis...... 182

Mitchell, , water analysis cited.......... 157

Mitchellite.................................. 665

Mixite....................................... 632

Mizzonite................................... 383

Moricke, W.. gold in pitchstone ........... 315,613

Mofettes..................................... 250

Mohawkite.................................. 628

Mohr, E. C. J., laterite...................... 470

rivers of Java............................ 96

Moissan, H., analyses of volcanic gases...... 255

carborundum in meteorite............... 310

graphite in native iron.................. 312

melting point of corundum............... 319

metallic carbides........................ 691

on diamond........................... 307,308

origin of petroleum...................... 694

origin of volcanic activity................ 267

volatility of metallic oxides............ 259,260

See also Becquerel and Moissan. 

Moitessier, A., artificial dolomite............. 636

Moldau River, analysis of water.............. 90

Moldenhauer, F., analysis by................ 89

the Dead Sea............................ 157

Molengraaf, G. A. F., cordierite vitrophyrite. 385 

Molengraaf, P. F., cassiterite................ 656

Molybdenite........................... 318,666,667

Molybdenum, distribution................... 18
764 INDEX.

Page. 

Molybdenum, ores of.................. 666,667,668

Molybdic ocher............................. 666

Molybdophyllite............................ 651

Molybdosodalite............................. 355

Monazite.............................. 338,679,680

Moncbiquite................................. 426

Monchiquose................................ 426

Monckton, G. F., mercury deposits.......... 638

Monetite.................................... 496

Monke, H., and Beyschlag, F., origin of

petroleum....................... 697

Monmouthite................................ 423

Mono Lake, analysis of water.............. 150,165

Monongahela Eiver, analysis of water....... 72

Montesano Springs, analysis................. 172

Monticellite............................... 370,372

Montmorillonite........................... 395,584

Montroydite................................. 634

Monzonite................................. 428,429

fusibility................................. 282

Monzonose............................ 417,426,433

Moore, C. C., barytic sandstones............. 515

sandstones.............................. 517

Moore, E. J., bog iron ore.................... 506

Moore, G. E., analysis by.................... 186

Moosehead Lake, analysis of water.......... 66

Morawsky, T. See Schinnerer and Moravvsky. 

Mordenite................................... 395

 Moreing, C. A., manganese ores-.............. 510

Morenosite.................................. 663

Morley, E. W., variations in atmospheric

oxygen.......................... 41,42

Morlot, A. von, sand calottes................ 513

synthesis of dolomite.................... 535

Morozewicz, J., alteration of diorite.......... 464

analysis by............................ 444,464

artificial feldspars....................... 346

composition of nephelite................. 353

formation of acmite...................... 361

of augite............................. 363

of corundum...................... 319-322

of enstatite.......................... 358

of hematite.......................... 330

of iolite.............................. 385

of magnetite,......................... 328

of melilite........................... 379

of mica.............................. 375

of neplielite.......................... 354

of quartz and tridymite............. 343

of sillimanite........................ 388

lagoriolite............................... 381

gravitative adjustment in magmas....... 297

syntheses of noselite, hauynite and sodalite.............................. 356

of pyroxenes......................... 360

solubility of alumina in magmas........ 297

Morrey, C. B., origin of petroleum.......... 702

Morse, H. W., gases in fluorite.............. 319

Morton, E.H. See Thorpe, T. E.

Moses, A. J., mercury minerals.............. 634

Moses, 0. A., phosphate rock.......;........ 501

Moses Lake, analysis of water............. 151,164

Mosesite............ I........................ 634

Moss, E. L., on Arctic air................... 45

Page. 

Mottramite.................................. 674

Moulton, F. R., internal temperature of the

earth............................ 277

Moureu, C., and Biquard, R., argon and

helium in waters................ 169

radioactivity of waters.................. 169

Mourlot, A., vanadium in coal............... 673

Mrazec, L., petroleum....................... 698

Mrazec, L., and Teisseyre, W., Roumanian

salts............................. 222

salt lakes of Roumania................... 161

Mrha, J., kelyphite.......................... 382

Muchin, J., von, analyses by................ 669

Muck, F., constitution of coal............... 730

Muck, J., ozokerite.......................... 687

Muds, oceanic............................. 488,489

Miigge, O., calcite and aragonite............. 527

fluorite as cement....................... 515

occurrence of perofskite.................. 332

scapolite amphibolite.................... 571

transition of quartz...................... 342

Miilhauser, O.,artificialgrrphite............ 310

Miiller, E., water analyses. ................. 92

Muller, H., mine water...................... 604

Muller, R., solubility of minerals...... 337,454,495

Muller, W., artificial magnetite.............. 327

Muller, W. J. See KQnigsberger and Muller. 

Muellerite................................... 496

Miinster, C. A., gold in sea water............ Ill

Miinster, H., bauxite........................ 473

Munroe, C. E., artificial hematite............ 329

Muntz, A., atmospheric transport of salt..... 51

bacterial decomposition of rocks....... 460,461

bromine in Chilean niter................ 243

nitrates in the Nile...................... 96

origin of nitrates.......... v ............ 245

Muntz, A., and Aubin, E., oxygen of the

atmosphere..................... 41

Muntz, A., and Laine", E., nitrates in the atmosphere. ...................... 50

Muntz, A., and Marcano, V., black waters of

South America.................. 82

cave nitrates.....................'.....".. 241

nitric acid in rainfall.................... 49

Murdoch, J. A. W., atacamite............... 632

Murgoci, G. M., amphiboles................. 367

glaucophane schists..................... 565

riebeckite rocks......................... 369

Murray, Sir J., chemical reactions on ocean

floor............................. 119

oceanic carbonic acid^................... 133

origin of manganese nodules............. 121

saline matter in rivers................. 102,106

total annual rainfall and run-off......... 56

volume of the ocean..................... 22

Murray, J., and Irvine, R., ammonia in sea

water........................... 110

calcium carbonate in sea water.......... 117

discharge of rivers....................... 116

formation of siliceous ooze............... 491

maintenance of marine life.............. 136

manganese nodules...................... 121

re-solution of coral rock................ 117-119

secretionoflimesaltsbymarineanimals.. 119 

sediment in sea water................... 482
INDEX. 765

Page. 

Murray, J., and Irvine, R., silica in sea

water......................... 110,491

Murray, J., and Renard, A. F., deep sea deposits. .......................... 119

glauconite............................... 492

oceanic sediments. .....t.............. 487,488

origin of glauconite...................... 124

phosphatic nodules.................... 123,500

solubility of silica....................... 119

Murray, R.M., the Dead Sea................ 157

Muscovite...............................;. 372-376

Muskingum River, analysis of water......... 72

Naab, River, analysis of water.............. 92

Nadorite.................................... 651

Nagyagite................................... 645

Nahe, River, analysis of water .............. 89

Nantier, A., phosphorite..................... 504

Nantokite................................... 632

Napalite................................... 637,687

Naphtenes................................... 684

Naphthalene. ........... ^.................. 685

Naschold, W. See Hauessermann and

Naschold. 

Nasini, R., origin of boric acid............... 234

See also Perrone and Nasini. 

Nasini, R., and Anderlini, F., analysis by... 173 

Nasini, R., Anderlini, F., and Salvador!, R.,

fumarole gases................. 169,234

Nasini, R., and Levi, M. G., radioactivity of

lava............................. 300

Nasini, R., Levi, M. G., and Ageno, F., water

analysis......................... 177

Nason, F. L., Franklin zinc ores............ 645

iron ores................................. 549

scapolite rocks........................... 571

Nasonite....................'............... 645,651

Nastukofl, A., cellulose....................... 705

Natrolite.................................... 395

Natron............................ 151,227,231,235

Natron Lake, analysis of water............ 162,165

Natterer, K., ammonia in sea water......... no

analyses of water.................. 113,114,158

carbonates in sea water.................. 133

marine muds............................ 491

on marine clays........................ 127,491

Natural gas........................ 682,683,696,697

Naumannite............................... 622,645

Navnrro, F., native iron..................... 312

Neagh, Lough, analysis of water............. 85,98

Nebular hypothesis.......................... 129

Negro, Rio, analysis of water................ 83,98

Nelson, J. L., analysis by.................... 365

Nelson River, analysis of water.............. 80

Nelsonite.................................... 445

Nendtwich, , analysis by ................ 712

Nentien, , antimony ores................ 658

Neodymiura................................ 18,679

Neon.................................... 18,40,683

Neosho River, analysis of water.............. 76

Nephelite.................................. 353,354

melting point............................ 279

Nephelite basalt............................. 436

Nephelite rocks............................ 420-423

Page. 

Nephelite syenite............................ 422

Nepouite.................................... 604

Nesquehonite................................ 538

Nessler. See Petersen and Nessler.

Neuberg, C., origin of petroleum............. G97

Neumann, P., diamonds in iron............. 307

Neuse River, analysis of water............... 07

Nevadite.........'........................... 412

Nevius, J. N., tin deposits................... 654

Nevyanskite................................. 668

Newberry, J. S., bog-iron ore................ 506

cannel coal.............................. 718

origin of petroleum.................... 700,701

ozokerite................................ 687

Newbery, J. C., gold in iron ore.............. 617

Newberyite.................................. 496

Newland, D. H., iron ores................... 445

Newland, D. H., and Leighton, H., gypsum. 220 

Newsom, T. F. See Branner and Newsom. 

Newton, W., origin of nitrates............. 244,246

Newtonite................................. 395,584

New Zealand geysers, analyses of waters...... 180,

185,189 

sinter from.............................. 196

Niccolite.................................... 660

Nichols, H. W., cave nitrates................ 241

corals and crinoids..................... 531,540

sand barites............................. 514

Nicholson, E., analysis of water............. 96

Nickel, distribution......................... 18

in ashes of sea weed...................... Ill

ores of................................. 660-664

Nickel-iron, native........................ 313-315

.Nicolardot, P., hydroxides of iron........... 507

Nile River, analysis of mud.................. 481

analyses of water........................ 96

sedimentation in........................ 482

Niobium. SceColumbium.

Niton...................................... 13,300

Nitrate deposits........................... 241-246

Nitric acid in rainfall........................ 49

Nitrogen, distribution....................... .18

in sea water............................. .109

proportions in the atmosphere........... 40

volcanic origin of........................ 259

Nitrogen bases in petroleum................. 686

Nitroglauberite.............................. 243

Nitze, H. B. C., iron ores.................... 549

monazite.............................. 339,679

Nivenite................................... 675,680

Nivoi t, E., phosphate rock.................. 495

Nocerite.......'.............................. 258

Noeggerath, J. J., pyromorphite in slag...... 651

Noellner, C., origin of nitrates............... 244

Noelting, J., zinc blende..................... 639

Noir, Lac.................................... 87

Noll, J. C., cited............................. 89

Nontronite.................................. 468

Nordenskiold, A. E., carbon in meteorite.... 695

native iron in Greenland................. 312

uranium in coal......................... 677

Nordenskioldine........................... 652,654

Nordmarkite................................ 416

Nordmarkose.............................. 416,422

Norite....................................... 439
766 INDEX.

Page. 

North Platte River, analysis of water........ 74

Northupite.................................. 235

Norton, J. H., cited......................... 75

Nosean. See Noselite.

Nosean sanidinite........................... 425

Noselite.................'.......:.......... 355-357

Noumeite................................... 664

No vaculite................................ 518-520

Noyes, W. A., analyses by........... 65,71,178,463

Nutter, E. H., and Barber, W. B., glaucophane rocks..................... 565

Nyholm, E. T. See Ramsay and Nyholm.

0. 

Oak Orchard acid spring, analysis........... 187

Obalski, J., uranium in pegmatite........... 678

Obsidian.................................... 412

fusibility of.............................. 283

Occlusion of gases in rocks................. 260-271

Ocean, age of.............................. 137-142

' composition of.......................... 23,207

elements in............................ 109-112

gases in................................ 130-135

influence of living organisms on........ 136-137

the primeval............................ 129

volume of............................... 22

Ocean water, carbonates in................ 117-119

changes in composition due to freezing... 115 

concentration of....................... 207-210

density and salinity of................. 112-116

Oceanic salts, composition of.............. 112-115

volume of............................... 22

Oceanic sediments................. 119-126,487-491

Ochers as spring deposits.................. 193-194

Ochrolite.................................... 651

Ochsenius, C., average composition of igneous

rock............................. 26

cited, on Stassfurt salts................ 209,210

on Great Salt Lake...................... 144

origin of alkaline carbonates............. 230

of borates............................ 240

of petroleum....................... 698,699

of salt beds............ '.. .......... 209,210

saltpeter deposits.................. 241,242,245

Ocmulgee River, analysis of water........... 68

Oconee River, analysis of water.............. 68

Octahedrite............................... 333,334

Oder, River, analysis of water............... 94

Oebbeke, K., glaucophane rocks........... 369,565

Oehmichen, H., chalcanthite................ 632

Ogden River, analyses of water.............. 145

Ojo Caliente, analysis of water............... 180

Okenite..................................... 395

Oklahoma, river waters...................... 75

Oldham, R. D., laterite...................... 469

Old Wives Lake, analysis of water......... 152,163

Oleflnes..................................... 684

Olette Springs, analysis...................... 184

Oligoclase................................... 346

Olivenite......... 1.......................... 632

F Olivier, V., Chilian nitrates................ 242

Olivine.................................... 369-371

melting point............................ 279

Om, River, analysis of water................ 95

Omeose...................................... 415

Omphacite.................................. 572

Page. 

Onega, Lake, analysis of water.............. 95

Onofrite.............:....................... 634

Onyx marble................................ 525

Oolite, calcareous............................ 529

Oolite, siliceous.............................. 520

Oolitic sand........................... 146,525,533

Oostanaula River, analysis of water.......... 68

Opal...................................... 339,340

Ophiolite.................................... 576

Ordonez, E.,petroleum...................... 695

Organic matter in rock decomposition.. ^.. 459,460 

Organic matter in waters.................... 97-99

Orpiment................................... 657

Orthite...................................... 386

Orthoclase................................. 345-349

Orthogneiss................................. 591

Ortlieb, J., ciplyte........................... 499

Orton, E., dissemination of petroleum....... 703

origin of petroleum...................... 697

spore cases in coal....................... 729

Osann, A., classification of igneous rocks..... 403

rock diagrams........................... 451

Osmium............................ 18,315,668-672

Osteolite.................................... 496

Oswegatchie River, analysis of water........ 65

Ottawa River, analysis of water............. 65

Otten, F. K., river waters................... 154

Ottreh'te........................... 373,376,585,586

Ottrelite schist.............................. 587

Cutwater, R., analysis of water.............. 67,68

Ovenstone................................... 579

Owens Lake, analysis of water............... 150

soda from.............................. 227,228

Owens River, analysis of water............ 150,165

Oxygen, concentrated by solution.......... 48

distribution............................. 18

proportions in the atmosphere........... 40,41

solubility in salt water................. 130,131

Ozokerite.................................. 687,701

Ozone in atmosphere........................ 42

P.

Packard, R. L., analysis by................. 463

Pagenstecher, J. S. F., water analyses....... 89

Pahua Spring, analysis...................... 172

Paigeite................................... 652,655

Palache, C., crossite......................... 368

See also Jaggar and Palache; Lawson and 

Palache; Ransome and Palacho. 

Palic Lake, analysis of water.............. 161,164

Palladium.......................... 18,315,668-672

Palladium gold............................ 615,668.

Palm, 0. H. See Mabery and Palm.

Palmer, A., chlorine in river waters.......... 99

Palmer, C., alkali determinations............ 64

analyses by... 65,66,67,68,69,70,71,73,74,76,77 

composition of crinoids.............(.... 540

diatoms in peat......................... 199

interpretation of water analyses.......... 57

Palmerite................................... 498

Palmierite................................. 258,049

Pantanelli, D., origin of petroleum........... 698

Pandermite................................. 236

Papagayos, Rio de los, analysis of water ...... ,.84

Papavasiliu, S. A., emery................... 322
INDEX. 767

Page. 

Pappe, A., and Eichmond, H. D., water

analysis......................... 162

salt...................................... 219

Paraffin scries............................. 681,682

Paragonite.................................. 372

Paragneiss................................... 591

Paralaurionite............................... 649

Paramo cle Ruiz, hot spring, analysis........ 188

Parana, River, analysis of water............. 83

Pargasite.................................... 365

Park, J., mercury ores....................... 638

Parker, H. N., waters of Kansas............. 75

Parmeleo, C. W. See McCourtand Parmelee. 

Parmenticr, F., alumina in mineral waters.. 472

synthesis of quartz and tridymite........ 341

Parr, S. W., classification of coals............ 722

Parry, J., gases in iron....................... 273

Parsons, A. L., gypsum..................... 220

peat..................................... 711

Paschen, F., heat of radium................. 299

Passarge, S., laterite......................... 470

Patronito.................................... 674

Patten, H. E., and Waggaman, Vf. H., absorption in soils.................. 477

Patton, H. B., formation of tourmaline...... 393

Payen, A.., Tuscan fumarclcs................ 233

Pearce, R., solvent of gold................... 623

uraninite................................ 675

Pearceite.................................... 623

Pearl River, analysis of water............... 69

Peat................................'... 708-711,721

cupriferous.............................. 627

diatoms in.............................. 199

Pecher, F., cited............................. 92

Peckham, S. F., albertite.................... 688,

origin of petroleum...................... 700

petroleum............................... 686

Peckham, S. F. and H. E., sulpiur in petroleum............................ 686

Pecos River, analysis of water............... 77

Pcctolite..................................... 395

Pedee River, analysis of water............... 68

Peganite..................................... 496

Peile, W., bauxite........................... 473

Peipus, Lake, analysis of water............. 95

Pelikan, A., analcitephonolite............... .352

Pellini, G., and Quercigh, E., tellurides of

gold............................. 616

tellurides of silver........................ 623

Pemberton, IT., and Tucker. G. P., water

analyses......................... 152

Pencatito.................................. 544.545

Penfleld, S. L., analyses by.................. fi80

' caesium beryl........................... 393

sulphohalite............................. 235

See also Dana and Penfleld; Genth and 

Penfield; Iddings and Penfleld; 

Wells and Penfleld.

Ponfleld, S. L., and Foote, II. W., composition of tourmaline............... 392

magnesia in ilmenite..................... 331

Penfleld, S. L., and Forbes, E. H., fayalite

in granite........................ 371

Penfield, S. L., and Ford, W. E., sand calcite.............................. 513

Ponfleld, 8. L., and Jamieson, G. S., tychite. 235

Page. 

Penfleld, S. L., and Minor, J. C., formula of

topaz............................ 388

Penfleld, S. L., and Pratt, J. n., formula of

staurolite........................ 390

Ppnfield. S. L., and Sperry, F. L., chlorite

pseudomorphs................... 382

Penfleld, S. L., and Stanley, F. C., composition of hornblende............. 305,367

Penfleldite.................................. 649

Penhale, M., chromite deposits.............. 666

Pennin.ite................................... 377

Penrose, R. A.F.,alterationsoforedeposits.. 610 

causes of ore shoots...................... 610

Chilean nitrates....................... 242,245

iron ore from glauconito............... 500,547

manganese ores.......................... 510

phosphate rock........................ 495,504

tin deposits.............................. 654

Pentlandite............................... 660,661

Perchlorates in Chilean niter................. 243

Percy, J., coal analysis...................... 719

Percylite.................................... 649

Periclase.............................. 544,545,596

Peridot...................................... 370

Peridotite................................. 442,443

Periodic classification of the elements....... 34-38

Perofskite................................. 331,332

Perrey, A. See Hautefeuille and Perrey. 

Perrone, E., origin of borates................ 234

Perrot, F.'L. See Jaquerod and Perrot. 

Peter, R., matter extracted from soil by

plants.....................'...... 460

cited.................................... 172

Petermann, A., and Graftiau, J., cited...... 44,49

Petersen, T., bauxite........................ 473

nickel in magnetite...................... 327

Petersen and Ncsslcr, analyses of peat....... 709

Petersen and Schodlcr, analyses of wood.... 706

Pctersson, W., analysis by................... 444

Petrasch, K., fusion of mineral mixtures.... 291

Pctrenko, G. I., silver antimonide........... 621

Petroleum.............................. '... 681,704

Pettcrsson, 0., on brine from melting ice.... 114

Pettersson, 0., and Sondfin, K., on air from

sea water....................... 48. ] 30

Petzite...................................... 616

PfaiT, F. W., dolomitization................. 538

Pfeiffer, E., cited on Stassfurt salts.......... 210

Pfordten, O. von dor. See Konig, T.

Phacelite.................................... 353

Phalen, W.C., unakite.................... 572,573

Pharmacolite................................ 659

Pharmacosiderite............................ 659

Phenol, in petroleum........................ 686

Philip, R. S. See Gibb and Philip.

Philippi, E., carbon dioxide and climate.... 47

dolomite................................. 538

Phillips, A. n., carnotite.................... 677

Phillips, F. C., formation of marsh gas...... 697

natural gas.............................. 683

petroleum in fossils...................... 699

Phillips, J. A., action of sea water on rocks.. 543 

desert sand.............................. 479

gold on cinnabar.....................'.... 617

mercury deposits........................ 638
768 INDEX.

Page. 

Phillips, J. A., mine waters................. 604

sandstone.................".............. 517

Phillips, W. B., iron ores.................... 549

petroleum............................... 685

phosphorite............................. 501

Terlingua mines......................... 634

Phillips, W. B., and Hancock, D., bauxite.. 474 

Phillipsite................................. 120,395

Phipson, T. L., primitive atmosphere....... 53

Phlegrose................................... 416

Phlogopite................................ 373-376

Phcenicochroite............................. 650

Phonolite................................... 420

fusibility................................ '282

Phosgenite................................ 646,648

Phosphate rock........................... 495-504

Phosphatic nodules ........................ 123,501

Phosphorite............................... 495-504

Phosphorus, distribution.................... 18

in sea water............................. 110

Phosphosiderite............................. 496

Phyllite............................... 581,584,586

Phytostearin................................ 703

Pichard, P., solubility of minerals........... 454

Pickeringite................................. 237

Picotite..................................... 326

Picrite.................................... 440,441

Picromerite................................. 212

Piedmontite................'.............. 386,387

Pierre, I., salts in rainfall.................... 51

Pigeon River, analysis of water.............. 65

Pilkington, B., water analyses.............. 78

Pilotti, C., phosphates...................... 501

Pimelite.................................... 664

Finite..................................... 384,386

Pinnoite.................................. 214,238

Pinnow, J. See Will and Pinnow.

Pirovaroff, J., chlorine in rain............... 50

Pirsson, L. V., cassiterite in hematite........ 653

crystallization of magmas...............: 297

primary analcite...................... 352,426

See also Weed and Pirsson. 

Pirssonite................................... 235

Pisani, F., analysis of spinel................. 324

See also Saemann and Pisani. 

Pisolite..................................... 527

Pissis, A., nitrates........................... 242

Pistomesite................................. 545

Pitchblende................................. 675

Pitch coal............................. 687,688,712

Piutti, A., helium in minerals............... 304

Plagionite................................... 647

Planetesimal hypothesis.................... 55,129

Plata, River, analyses of water.............. 83,98

Platiniridium............................... 670

Platinum, distribution...................... 18

in igneous rocks......................... 315

ore of.................................. 668-672

Platte River, analyses of water........... 59,61,74

Plattensee, analysis of water................. 94

Plattnerite.................................. 647

Plauchud, E., reduction of sulphates by microbes........................... 551

Playa Lakes................................ 225

Playfair, L., colliery gases................... 726

Pleonaste................................. 324,326

Page.

Plombieres, action of hot waters at, on brick.. 199 

analyses of waters cited...... :. ......... 199

Plumbogummite............................ 651

Plumbojarosite.............................. 649

Plummer, G. W., pyrite and marcasite...... 318

Podolite..................................... 338

Poeschl, V., silicate fusions.................. 291

Pogue, J. E., sand barites................... 514

Pollard, W., uranium and vanadium in rocks. 673

See also Clough and Pollard. 

Polianite.................................... 508

Polonium.............................. 12,299,676

Polyargyrite.............................. 623,624

Polybasite.................................. 623

Polydymite............................... 660,672

Polyhalite................................. 212,215

Polylithionite............................... 372

Polymethylenes............................. 684

Pomeroy, Ohio, brine....................... 171

Ponteil, 0. du, water analysis............... 189

Poole, H. H., radioactivity.................. 300

Popocatepetl, water from.................... 189

Popoff, L., gas from river mud.............. 697

Popoff, S. P. See Vernadsky and PopofT. 

Popovici, Saligny and Georgesco, water

analysis......................... 161

Popp, 0., boron nitride..................... 233

urao..................................... 226

water analysis........................... 97

Porcher, S., electrum........................ 615

Porter, F. B. See Bailey, E. H. S.

Porter, J. L., analysis of water.............. 70

Porter, J. T., fuller's earth................... 484

PoSepny, F., atmospheric transport of salt... 51 

lateral secretion....................... 600,601

'heavy metals in waters.. ................. 604

ore deposits............................. 599

Posewitz, T., asphalt and petroleum......... 689

Potassium, distribution..................... 19

in seaweed.............................. 128

proportion of, in ocean................ 127,128

Potassium nitrate. See Saltpeter.

Potassium salts, absorption by clays....... 127,200

Potomac River, analysis of water............ 67

flow of.................................. 68

Potonie', H., origin of coal................... 707

origin of petroleum...................... 701

Pouget, I., artificial pyrargyrite............. 624

Powder River, analysis of water............. 78

Powellite.................................... 666

Power, F. D., nickel ores.................... 664

Pozzuoli, analysis of solfatara water.......... 188

Praseodymium............................. 19,679

Praseolite................................... 385

Pratt, J. H., chromite deposits............ 327,666

corundum............................... 322

gaylussite, northupite, pirssonite........ 235

occurrence of spinel...................... 326

origin of talc............................. 394

talc..................................... 578

See also Hidden and Pratt, Penfleld and

Pratt.

Pratt, J. H., and Lewis, J. V., chromite deposits ......................... 322,666

Pratt, J. H., and Sterrett, D. B., tin deposits. 655 

Pratt, N. A., phosphate rock................ 502
INDEX. 769

Page. 

Precht, H., cited, on Stassfurt salts.......... 210

on langbanite............................ 212

Precht, H., and'Wittjen, B., kieserite....... 216

Precht, J., heai of radium................... 299

See also Eunge and Precht. 

Predazzite............................. 544,545,596

Prehnite rock............................... 597

Preis werk, H., sodalite trachyte............. 357

Pressure and chemical change............... 277

Prestwich, J., water in volcanism............ 270

Pretoria salt lake, analysis of water........ 162,165

Price, T., water analysis cited............... 78

Priceite..................................... 236

Priestley, J., gases in rocks.................. 261

Primero, Rio, analysis of water.............. 84

Pring, J. N., and Hutton, R. S., synthetic

. hydrocarbons.................... 692

See also Hayhurst and Pring. 

Prior, G. T., dundasite...................... 648

riebeckite rocks.......................... 369

teallite,etc.............................'. C52

See also Hussak and Prior. 

Prior, G. T., arid Spencer, L. J., cerargyrite

group............................ 625

Prismatine.................................. 302

Priwoznik, E., native iron................... 315

Prochlorite................................ 377,574

. Prost, E. See Spring, W. 

Proustite.................................. 623,624

Prowersose.................................. 419

Przibylla, C., formation of carnallite......... 214

Pseudoboleite............................... 649

Pseudobrookite........i..................... 331

Pseudogaylussite............................ 148

Pseudoleucite............................... 352

Pseudonephelito............................. 333

Psilomelane................................. 509

Psittacinite.................................. 651

Pteropod ooze......................... 120,488,489

Ptilolite..................................... , 395

Puchcrite.................................... 674

Puiggari, M.,cited............................ 83

Pulaskose............................. 416,426,432

Pulgar, P. del. See Calderon, C. S., etc. 

Pumpelly, R., native copper................ 626

loess..................................... 485

sedimentation........................... 488

Purdue, A. H., phosphate rock.............. 502

Purington, C. W., Uralian platinum......... 670

Pyramid Lake, analysis of water.......... 147,165

Pyrargyrite................................ 623,624

Pyrite............................. 258,316-318,603

Pyrocatechin................................ 731

Pyrochroite................................. 508

Pyrolusite................................... 509

Pyromorphite............................. 650,651

Pyrope...................................... 380

Pyrophanite................................. 331

Pyrophyllito .......................... 395,578,584

Pyrostilpnite.............................. 623,624

Pyroxene.......................... 357-364,564,576

Pyroxenrite................................ 441

Pyrrhotite..................... 258,316-318,661,662

101381° Bull. 491 11 49

Q.

Page.

Quadrat, B., analysis of spinel............... 324

Quartz.................................... 339-345

gaseous inclusions in..................... 261

melting point............................ 279

volatility of........................... 259-260

Quartz-alunite rock........................ 473,474

Quartz basalt................................ 434

Quartz-diaspore rock........................ 473

Quartz diorite............................... 430

Quartz monzonite........................... 428

Quartz porphyry............................ 414

Quartz trachyte............................. 412

Quartzine................................... 339

Quartzite.................................. 579-581

Quayle, W. 0. See Mabery and Quayle. 

Quensel, P. L\, formation of quartz and

tridymite...................... 279,342

Querclgh, E. See Pellini and Quercigh. 

Quercylite.................................. 499

Quincy mine, water from.................... 174

Quinton, R., ocean water.................... 109

Quisqueite................................ 674,713

R.

Raben, E., nitrogen and silica in sea water .. .110 

Radioactivity..................... 204,298-304,676

Radiolarian ooze...................... 120,488,489

Radiothorium.............................. 12,300

Radium............................ 19,299-304,676

. in sea water........................... 111.300

in springs............................... 204

Radominsky, F., synthesis of monazite and

xenotime........................ .338

Ragsky, F., analysis by..................... 182

Rainfall..................................... 48-51

Raken, M. See Cohen, E.

Rakusin, M., petroleum..................... 703

Ramage, H. See Hartley, W. N.

Ramirite.................................. 674,677

Rammelsberg, C., composition of tourmaline.............................. 392

Rammelsbergite............................. 660

Ramsay, Sir W., composition of the atmosphere... ......................... 40

sedimentation........................... 482

See also Rayleigh and Ramsay. 

Ramsay, W., and Travers, M. W., argon and

helium in minerals.............. 261

Ramsay, W. (of Helsingfors), and Illiacus,

A., monazite in pegmatite....... 338

Ramsay, W., and Nyholm, E. T., cancrinite

syenite.......................... 357

Ramsay and Hunter, sintering of silica...... 345

Rangeley Lake, analysis of water........... 66

Rankin, G. A. See Shepherd and Rankin. 

Ransome, F. L., alunite and diaspore..... 242,474

chert.................................... 519

enrichment of sulphides................. 611

glaucophane schist...................... 565

lawsonite................................ 391

See also Hillebrand and Ransome. 

Ransome, F. L., and Palache, C., lawsonite.. 391
770 INDEX.

Page. 

Raritan River, analysis of water............. 66

Rastall, R. H. See Hatch and Rastall.

Rath, G. vom, anorthite in marble.......... 595

cristobalite.............................. 339

sublimed silicates........................ 260

sulphur deposits......................... 552

Rathite..................................... 647

Rayleigh, Lord, argon in springs............ 169

hydrogen in atmosphere................. 43

Rayleigh, Lord, and Ramsay, W., argon in

springs.......................... 169

Raymond, R. W., uintaite......"............ 687

Read, T. T., copper sulphide................ 630

phase rule............................... 290

platinum................................ 672

Reade, T. M., chemical denudation....... 103,105

Realgar................................... 257,657

Reclmagel, R., origin of tin deposits......... 655

Rectorite.................................... 584

Red clay, oceanic.......................... 488,490

Red Lake, analysis of water............... 158,163

Red River (Louisiana), analysis of water.... 76

Red River of the North, analyses of water... 80 

Red Sea, analyses of water.................. 113

Redingtonite................................ 665

Redlich, K. A., and Cornu, F., talc deposits.. 578 

Redwood, B., formation of petroleum....... 700

Reese, C. L., solubility of calcium phosphate. 495 

Refdanskite................................. 664

Regen, River, analysis of water.............. 92

Regnault, V., oxygen of the atmosphere..... 41

Reich, A., synthesis of sillimanite........... 388

of topaz................................. 388

See also Stutzer, A. 

Reichardt, E., analysis of bittern............ 221

Reichardtite................................. 212

Reichert, F., Argentine borates.............. 237

Reid, C., and Scrivenor, J. B., cassiterite...... 653

Reid, J. A., mine water...................... 604

Reid, W. F., Argentine nitrates............. . 244

Reinders, G., bog-iron ore................. 506,507

Reindl, J., cited............................. 82

Reinitzer, B., trona.....................'..... 228

Keiset, J., carbon dioxide in air.............. 44

Reiter, H. H., fusion of mineral mixtures.... 291

Reitinger, J. See Hussak and Reitinger. 

Remingtonite............................... 663

Renard, A. F., phtham'te.................... 518

phyllites................................ 587

See also Murray, J.

Renard, A. F., and Cornet, J., phosphorite... 500 

Renault, B., cannel coal......'............... 718

peat..................................... 718

microorganisms in coal.................. 729

See also Bertrand and Renault. 

Rennie, E. H., vanadium in clay............ 673

Republican River, analysis of water......... 75

Retgers, J. W., constitution of pyroxenes.... 364

minerals in sand......................... 480

Reuter, M. See Treadwell, F. P.

Reyer, E., volcanism........................ 271

Reyes, Rio de los, analysis of water.......... 84

Rezbanyite.................................. 647

Rheineck, H., composition of tourmaline.... 392

Rhine, River, analysis of silt................ 481

analyses of water........................ 89,98

Rhodium........................... 18,315,668-672

Rhodium gold............................... 668

Rhodochrosite................... '. ......:.... 545

Rhodonite................................... 360

Rhodusite................................... 368

Rhoenite.................................... 368

Rhone, River, analysis of water............. 86

Rhyolite.................................. 412,413

fusibility................................ 2S5

Riban, J., synthesis of cerussite.............. 648

Ricciardi, L., vanadium in lava............. 673

Richards, Ellen S., chlorine maps........... 50

Richards, R. H. See Day and Richards. 

Richards, R. W. See Gale and Richards. 

Richardson, C., asphalt........^........... 688,689

grahamite............................... 689

Richardson, C., and Wallace, E. C., Texas

petroleum....................... 685

Richardson, G. B., natural gas.............. 683

sulphur deposits......................... 552

tin deposits.............................. 655

waters of Utah.......................... 144

Richardson, T., barytic deposit.............. 553

Richmond, H. D. See Pappe, A. 

Richterite.......................\........... 364

Richthofen, F., loess......................... 485

Rickard, E., tin deposits.................... 655

Rickard, F.. tungsten ores................... 60S

Rickard, T. A., precipitation of silver........ 620

solution and deposition of gold......... 618,619

Rickardite.................................. 628

Ricketts, L. C., cited......................... 152

Riebeckite.................................. 368

Rieke, R., melting points of silicates......... 278

Riemann, C., Stassfurt salts.................. 210

Ries, H., alteration of pyroxenes............. 363

clays.................................... 484

limestones............................... 533

peat..................................... 711

zincite................................... 641

Riess, E. R., eclogite........................ 572

Rigaud, F., origin of coal and petroleum..... 695

Riggs, R. B., analyses by.................... 430,

483,484,486,547,570,581,592 

Riley,, E., titanium in clays................. 476

Rimann, E., magmatic sphalerite............ 641

Rinne, F., reactivity of quartz............... 345

Rinne, F., and Kolb, R., Stassfurt salts...... 214

Rinneite.................................... 214

Rio Grande, analysis of water............... 77

Rising, W.-B. See Le Conte and Rising.

Risler and Walter, Lac Le'man.............. 86

Ritom, Lac, analysis of water............... 87

Ritter, A., nature of earth's interior.......... 55

Rivas, S., cited.............................. 83

Roanoke River, analysis of water............ 67

Roberts, J. See Anderson and Roberts.

Roberts, M. G., analyses by...... 64,65,66,67,68,73

Roberts-Austen, W. C., melting points of

minerals....................... 278,279

Robinson, A. C., and Mabery, C. F., analysis

by..........;.................... 174

Robinson, F. C., analyses of water........... 66

phosphoric acid in beryl................. 393

Robertson, J. D., heavy metals in rocks... 601,643

precipitated zinc sulphide............... 640
INDEX. 771

Page.

Robertson,'J. D., zinc deposits............... G44

Rockbridge Alum Spring, analysis........... 187

Rock River (Illinois), analysis of water...... 72

Rock River (Minnesota), analysis of water... 71

Rodzyanko, A., cited........................ 08

Roeblingite.................................. 651

Roepperite.................................. 370

Roesler, H., kaolinization.................... 468

Roessler, F., synthesis of argentite......'..... 621

of galena and clausthalite............ 645

Rossler, H., platinum in silver bullion....... 671

Rottisite..................................... 664

Rofe, ,T., cannelcoal......................... 718

Rogers, A. F., alterations of copper.......... 627

riebeckite rocks.......................... 3G9

Rogers, W. B. and R. E., solubility of minerals. ............................ 454

Rohland, P., plasticity of clays.............. 478

Roloff.M..cited............... ..............' 287

Romburgh, P. van, analysis by.............. 186

Romeite..................................... 659

Romer, E. von, cited........................ 137

Roncegno, analysis of water from............ 177

Rondet, J., sulphosalts of lead............... 647

Roozeboom, H. W. B., phase rule........... 290

Roscoe,H. E., mottramite. .........t....... 674

Roscoelite................................. 372,674

Rose, G., fusion of limestone................. 532

synthesis of tridymite................... 341

uralitization............................. 564

Rose, T. K., alloys of gold and tellurium.... 616

Roselite..................................... 663

Rosen, F., alteration of dolomite............. 545

Rosenbach, O., volcanic nitrogen............ 259

Rosenbusch, H., chloritic substance......... 574

classification of igneous rocks.......... 403,404

epidotization............................ 571

garnet and prehnite rock................ 597

glaucophane rocks....................... 369

gneiss................................... 591

order of deposition of minerals..... 2P?, 447,448

succession of minerals in igneous rocks. 447,448 

venanzite.............................. 435,436

See also Hunter and Rosenbusch. 

Rosenbuschite............................... 363

Rosenlecher, R., mercury deposits........... 638

Rosiwal, A., physical analysis of rocks....... 451

Ross, 0. C. D., origin of petroleum.......... 695

Rossel, H., carbide theory of volcanism...... 267

Roth, J.,predazzite.......................... 544

Rothpletz, A., oolitic sand................... 525

Roumania, salt lakes of...................... 161

Rousseau, G., artificial diamond............. 308

Roux, B., water analysis cited............... 156

Rowlandite.................................. 680

Rubidium, distribution..................... 19

in sea water............................. 110

Ruer, R., see Levin and Ruer.

Ruff, O., iron hydroxides.................... 507

Rumbold, W. R., tin deposits..........:.. 654,656

Rumpfite.................................... 377

Runge, C., and Precht, J., heat of radium... 299 

Ruppin, E., ocean water ................... 128,134

Russ, F., aluminum hydroxides............. 475

Russell, I. C., adobe soil..................... 485

calcareous tufa........................... 525

Page. 

Russell, I. C., disintegration of rocks........ 467'

gypsum................................. 217

Lake Lahontan........................ 143,147

residual clays........................... 534

Russian River (California), analysis of water. 79

Rust. See Fischer and Rust.

Ruszanda, Lake, analysis of water......... 161,165

Ruthenium ........................ 18,315,668-672

Rutherford, E., age of minerals.............. 303.

radioactivity.......................... 302,303

Rutherford, E., and. Barnes, E. T., heat of

radium. .....^................... 299

Rutile..................................... 333-335

Rutley, P.,novaculite....................... 518

Ryba, F., chromite deposit.................. 666

Rzehak, A., mercury deposits............... 638

S. 

Saale, River, analysis of water............... 90

Sabatier, P., and Senderens, J. B., synthetic

hydrocarbons................... 691

Sacc, F., niter in Bolivia.................... 244

Sachs, A., kleinite........................... 634

Sachsse, R., water analysis.................. 156

Sacramento River, analysis of water......... 79>

Sadtler, S. P., distillation of linseed oil....... 693.

natural gas.............................. 683.

Saemann, L., and Pisani, P., alteration of

cancrinite....................... 357'

Safflorite.................................... 660'

Safford, J. M., phosphorite.................. 501

Sahlbom, N., analysis by.................... 422;

Saiute-Gilles, L. P. de. See Hautefeuille and

Sainte Gilles.................... 374

St. Lawrence River, analyses of water....... 62

flow of.................................. 66

Saladillo, Rio, analysis of water............ 84,153

Salic minerals. ............................... 404

Salinas River, analysis of water............. 79

Saline River, analysis of water.............. 75

Salisbury, J. H., the Dead Sea............... 157

Salisbury, R. D., mineral matter in the sea.. 116

See also Chamberlin and Salisbury. 

Salitc........................................ 360

Salomon, W., occurrence of spinel........... 325

Salsomaggiore, water of, analysis............ 173.

Salt....................................... 217-219

Salt beds, origin............................ 206-210.

Saltet, R. H., and Stockvis, C. S., cited...... 102

Saltpeter.................................. 241,243

Salt River, analysis of water................. 77

Saluda River, analysis of water.............. 68

Salvador!, R., synthetic hydrocarbons....... 691

See aZso Nasini, R. 

Samarium.................................. 19,679

Samarsldte.......'........................... 678

Sambhar Salt Lake........................ 139,162

Samsonite................................... 623

Sand...................................... 478-480

Sandberger, F., analyses by................. 185

lateral secretion........................ 600,601

platinum in limonite.................... 671

serpentine............................... 575

Sandstone................................. 513-518

average composition..................... 28-31

Sandstone reefs.............................. 514
772 INDEX.

Page. |

Sanford, S., precipitated calcium carbonate.. 525 

fian Gabriel River, analysis of water......... 79

San Joaquin River, analysis of water........ 79

San Roman, F. J., water analysis............ 153

Santa Ana River, analysis of water.......... 79

, Santa Clara River, analysis of water, cited... 78 

Santa Maria River, analysis of water......... 79

Santa Ynez River, analysis of water......... 79

Saponite.................................... 395

Sapper, K., volcanoes of Java................ 270

Sapropel.................................. 701,707

Sarasin, E. See Friedel and Sarasin.

Saratoga waters, analyses.................... 175

Sardeson, F. W. See Hall and Sardeson. 

Sarkinite.................................... 659

Sartorite................................... 646,647

Sartorius von Waltershausen, and Lasaulx,

A. von, Etna.................... 253

Saskatchewan River system................. 80

Sassolite..................................... 232

Sauer, A., alteration of leucite to analcite...... 352

graphitoid............................... 720

kryptotile............................. 374,584

Saussurite............................. 386,568-570

Savage, T. E., peat.......................... 711

Savannah River, analysis of water........... 68

Savu-Savu Spring, analysis of............... 174

Saxonite.................................. 440,442

Saytzefl, A., Uralian platinum.............. 670

Scacchi, A., fluorite on lavas................ 319

leucite pseudomorphs................... 352

sublimed silicates....................... 260

Vesuvian sublimates.................. 249,258

Scandium.................................. 19,679

Scapolite.................................. 383-385

Scapolite rocks............................ 570-571

Scarpa, 0., radioactivity of lava............. 300

Schafarzik, F., the Medve Lake............. 161

Schafhautl, P., synthesis of quartz.......... 340

Schaller, W. T., analyses by:............... 587

barbierite............................... 345

bismuth ocher.......................... 659

dahllite and podolite.................... 338

dumortierite............................ 391

hulsite and paigeite..................... 652

molybdic ocher......................... 666

warrenite............................... 647

Schaller, W. T., and Hillebrand, W. F.,

lawsonite....................... 391

See also Hillebrand and Schaller. 

Schapbachite............................. 623,647

Schardt, H., subterranean erosion........... 199

Scharizer, R., composition of tourmaline..... 392

constitution of hornblende.............. 367

Scheelite.................................. 667,668

Scheerer, T., formation of dolomite.......... 540

of magnesian carbonates.'............ 536

Scheererite.................................. 687

Schefferite.................................. 360

Schenck, A., chloritization.................. 574

copper ores.............................. 629

epidotization.................. 387,571,572,573

Sobering, H. G.,loess....................... 485

Schertel, A., melting points of minerals...... 277

See also Stelzner and Schertel. 

Schertelite.................................. 496

Schickendantz, F., cited.................... 224

Schiebe, 0., gold in oli vine rock............. 613

Schilling, J., distribution of thorium........ 679

Schinnerer, L., and Morawsky, T., pyrocatechin from lignite.............. 731

Schirmerite............................... 623,647

Schist............................. 581-583,587-591

Schlagintweit, H. von, Tibetan borax....... 238

Schleimer, H., silicate fusions...... ........ 291

Schliersee, analysis of water................. 88

Schlosing, C., sedimentation................ 482

Schloesing, T., ammonia in atmosphere...... 50

ammonia in sea water................... 110

analyses of sea water.................. 112,113

oceanic carbonic acid.................... 132

plasticity of clays....................... 478

solubility of calcium carbonate ......... 117

solubility of calcium phosphate. _..... 498

tropical soils............................ 475

Schlundt, H., and Moore, R. B., radioactivity

of waters........................ 204

Schmelck, L., analyses by................. 113,419

marine clays............................ 127

marine muds............................ 491

Schmidt,-C., chamosite...................... 549

sericitic rocks........................... 567

Schmidt, C. (Dorpat), water analyses.,... 95,

112,114,154,158,160

fumaroles of Monte Cerboli.............. 232

Schmidt, R. E. See Lunge, G.

Schmidt, W. B., action of sulphurous acid on

rocks............................ 459

Schmitz, E. J., copper in fossil wood........ 627

Schmutz, K. B., artificial scapolite rock..... 384

formation of tridymite.................. 341

fusion of mineral mixtures.............. 291

Schnarrenberger, C., analyses by............ 597

Schneider, E. A., analyses by............... 196,

441,463,517,520,581

See also Barus, C.; Clarke and Schneider. 

Schneider, J., water analysis................ 161

Schneider, K., origin of perofskite........... 332

Schneider, O.,rinneite...................... 214

Schneider, R., cubanite..................... 628

precipitation of silver sulphide.......... 622

synthesis of emplectite.................. 631

of wittichenite...................... 631

of greenockite....................... 63g

of matildite......................... 624

Schodler. See Petersen and Schodler.

Schoeller, water analyses.................... 83

Schoenite................................... 212

Schorlomite................................. 381

Schrauf, A., kelyphite....................... 382

mercury ores.......................... 637,638

mine waters............................. 604

serpentine from garnet.................. 576

Schreibersite................................ 312

Schreiner, O., and Failyer, G. H., absorbent

power of soils................... 477

See also Kahlenberg, L. 

Schreiner, 0., and Shorey, E.G., organic matter of soils....................... 98

Schroter. See Friih and Schroter.

Schrotterite................................. 584

Schucht, F., cited.......................... 90,481
INDEX. 773

. Page. 

Schiller, E., synthesis of greenockite......... 639

Schviler, G., chromiam in a phosphate....... 499

Schurmann, E., precipitation of sulphides... 612 

Schutzenberger, P., volatility of silica ....... 259

Schulton, A. de, synthesis of analcite........ 351

synthesis of gibbsite..................... 474

of lanarkite.......................... 649

oflaurionite......................... 649

of malachite......................... 633

of molybdenite...................... 666

of northupite and tychite............ 235

of phosgenite........................ 648

See aJso Lacroix and De Schulten. 

Schultz, A. E,., cited......................... 152

Schultze, H., synthesis of wulfenite.......... 650

Schulze, H., and Stelzner, A., artificial tridymite............................. 341

artificial willemite....................... 642

Schunett, Lake, analysis of water......... 159,164

Schungite................................... 720

Schuster, M., fichtelite ...................... 711

Schwager, A., analyses by........ 88,90,92,481,494

Bavarian waters......................... 88

loess..................................... .485

river silt................................. 481

Schwantke, A., artificial tridymite.......... 341

chemical system of eruptive rocks....... 404

iron in basalt............................ 312

osteolite and staffelite................... 496

Schwartz, E. FI. L., African hot springs..... 202

interior of earth.......................... 39

primitive atmosphere...................'. 55

Schwartzembergite.......................... 648

Schwarzenbach, , the Dead Sea......... 157

Schweidler, E. von, and Hess, V. F., heat of

radium.......................... 299

Schweig, M., magmatic differentiation....... 298

Schweinfurth, G., and Lewin, L., origin of alkaline carbonates............... 230

Schweitzer, P., analyses by........ 172,177,180,182

Scolecite..................................... 395

Scorodite.................................... 657

as a spring deposit..................... 196-197

Scrivenor, J. B. See Reid and Scrivenor.

Scrope, P., volcanoes........................ 297

Seal, A. N., ozokerite........................ 687

Seamon, W. H., analyses by................. 615

tallow clays............................. 644

Secondary enrichment..................... 611,612

Sedimentary rocks......................... 513-556

average composition......'............ 28,30,31

volume of............................... 28,31

Sedimentation............................... 482

Seebach, M., native iron..................... 312

Seidell, A., water analysis.................. 78,145

See also Cameron and Seidell. 

Seine, River, analysis of water............... 86

Selenite. See Gypsum.

Selenium, distribution....................... 19

in mineral springs....................... 173

Selen sulphur ............................... 257

Sella, A., nickel iron........................ 314

Sellards, E. H., phosphate rock............. 502

Selle, V., origin of kaolin.................... 469

Semper, E., and Blanckenhorn, M., origin of

nitrates.......................... 244

Page. 

Semper and Michels, Chilean nitrates........ 242

Semseyite................................... 647

Senarmont, H. de, precipitation of silver..... 620

reduction of copper...................... 627

synthesis of chalcopyrite................. 628

of pyrargyrite and proustite......... 624

of pyrito............................. 317

of quartz............................ 340

of realgar, stibnite, and bismuthinite. 657 

of sphalerite......................... 639

sulphides of cobalt and nickel............ 661

Senarmontite................................ 659

Senderens, J. B. See Sabatier and Senderens. 

Sericite............................ 372,566-568,588

Serpentine............................. 394,575-579

Sestini, F., solubility of minerals............ 454

Se vier Lake, analysis of water............... 145

deposits from............................ 223.

Seybertite................................... 37a

Seyfert, F., water analysis.................. 94

Shale.............................. 521-524,581,582

average composition..................... 28,31

Shaler, N. S., bog iron ore................... 505

peat..................................... 70'J

phosphorite............................. 501

soils..................................... 484

Shales, metamorphosed................... 581,582

Sharpies, S. P., coral........................ 531

phosphate rock.......................... 497

solubility of calcium phosphate.......... 495

Sharpless, F. F. See Lane and Sharpless. 

Sharvvood, W. J., telluride gold ores......... 616

Sheep Creek, analysis of water............... 81

Shelton, H. S., rain and river water......... 137

Shenandoah River, analysis of water........ 67

Shepard, C. U., phosphate rock............. 497

Shepard, C. TL, .jr., phosphate rock.......... 497

Shepherd, E. S. See Day and Shepherd. 

Shepherd, E. S., and Rankin, G. A., binary

systems of alumina, etc.......... 278

synthesis of spinel....................... 325

Shepherd, E. S., Rankin, G. A., and Wright,

F. E.,cristobalitc............... 342

Sherzer, W. H.,celestite..................... 552

sand.................................... 480

Shiraz, salt lake near, analysis of water.... 158,162

Shoal Creek, analysis of water............... 177

Shonkinite................................ 418,419

Shonkinose.................................. 419

Shorey, E. C. See Schreiuer and Shorey. 

Shoshonose........................ 428,432,433,434

Shutt, F. T., and Spencer, A. G , water analysis.. .......................... 65

Sibertzew, N., soils ......................... 484

Siberian Ocean, analyses of water ........... 113

Sicha, A., action of carbonated water on minerals.... ......................... 456

Sickenberger, E., formation of petroleum.... 699

origin of alkaline carbonates............. 230

Sidener, C. F., analyses of water......... 70,71,171

Siderite............................... 397,545-547

Siderophyllite............................... 373

Sidot, T., synthesis of galena................ 645

synthesis of greenockite and wurtzite.... 639

of magnetite......................... 32V

of troilite............................ 316
'74

INDEX.

Page. 

Sidot, T., synthesis of zincite............... 641

.Siebenthal, C. E., limestone.. ................ 533

marl.................................... 526

Siedentopf, H., color of salt.................. 220

Siemens, E. W. von, volcanic explosions.... 275

Siepmann, P., constitution of coal........... 729

Siewert, M., water analysis................. 84,153

Silber, P. G., synthesis of nephelire.......... 354

Silica, in river waters....................... 99

in sea water............................. 110

volatility of........................... 259,200

Silicates, hydrolysis of....................... 183

solubility of........................... 119,120

Siliceous sinter........................ 194-196,519

Silico-azo-humic acid........................ 98

Silicon, distribution......................... 19

Silliman, B.,jr., the Dead Sea............... 157

 Sillimanite........................ 389,390,584,585

Sillimanite schist............................ 587

Silt........................................ 480-482

Silva, A. F. de, and d'Aguiar, A., fluorine in

spring waters.................... 180

Silver, distribution.......................... 19

in native copper ........................ 620

in sea water............................. Ill

in volcanic ash........................ 258,601

occlusion of oxygen by.................. 274

ores of................................. 619-625

Silver Islet, analysis of water from........... 174

Silver, L. P., nickel deposits................. 662

Silvestri, 0., fluid inclusion in sulphur...... 552

hydrocarbons in lava.................. 268,694

iron nitride.............................. 258

volcanic gases........................... 253

.Simmersbach, B., and Mayr, F.. nitrate deposits. .......................... 242

Simpson, E. S., native tin................... 652

Singer, F., zeolites........................... 396

Singer, L., origin of petroleum............... 698

Singer, M., constituents of wood............. 706

.Suiter, barytic...................... ...... 193,553

Sinter, calcareous.......................... 192,193

Winter, ferruginous.......................... 546

Sinter, siliceous................... 194,195,196,519

.Sipocz, L., analysis by...................... 494

krennerite............................... 616

See also Loebisch and Sipb'cz.

Siserskite.................................... 668

Sitaparite................................... 510

^Sjogren, H., bog-iron ore.................... 506

fluid inclusion hi sulphur................ 552

Scandinavian iron ores.................. 445

vesuvianite.............................. 383

Sjollema, B., perchlorates in soda niter...... 243

Skeats, E. M., acid water from sulphur beds.. 552

.Skeats, E. W., coralline limestone........... 531

magnesia in coral reef................... 542

phosphate rock.......................... 504

,Skey, W., analyses by............. 172,180,185,189

awaruite................................ 313

gold sulphide....................... 1.... 614

ocean water............................. 112

precipitation of gold..................... 619

of silver sulphide.................... 622

solvents of gold.......................... 617

Skinner, W. W., mineral springs............. 186

Page. 

Skinner, W. W., underground waters of

Arizona......................... 186

Sec also Forbes, R. H. 

Skutterudite................................ 600

Slate.............................. 521-524,581,582

Slichter, C. S., volume of ground water...... 33

Sloan, E., clays.............................. 484

Slosson, E. E., water analysis.............. 74,152

Smaltite..................................... 660

Smart, C., water analyses.................... 144

Smith, A. W. See Mabery and Smith.

Smith, B. H. See Hay wood, J. K.

Smith, E. A., phosphate rock................ 504

Smith, F. D., tungsten ores.................. 668

Smith, G. 0., molybdenite.................. 667

Smith, J., river waters....................... 85

Smith, J. G. See Failyer and Smith.

Smith, J. L., analysis by.................... 175

native iron............................ : . 312

Smith, J. P., eclogite........................ 573

glaucophane rocks..................... 369,565

lawsonite rocks.......................... 391

Smith, R. A., oxygen of the atmosphere..... 41

^ peat..................................... 709

Smith, Watson, resins in lignite.............. 714

Smith, W. S. T., zinc deposits............... 644

See also Ulrich and Smith. 

Smithite..................................... 623

Smithsonite....................... 640,642,643,645

Smoky Hill River, analysis of water......... 75

Smoot, L. E., analysis by................... 187

Smyth, C. H., alteration of pyroxene...... 358,359

Clinton iron ores......................... 506

corrosion of quartz..................... 345,457

limestone................................ 596

losses of atmospheric oxygen............. 54

melilite rocks............................ 380

metamorphosed gabbro.................. 571

talc.................................... 394,578

Smyth, H. L., iron ores...................... 329

Snake River, analysis of water............... 78

Soap Lake, analysis of water............... 151,165

Soda Lake, soda from........................ 226

Soda Lakes, analyses of water............. 148,165

Sodalite..............'..................... 355-357

Sodalite syenite....................... 357,425,426

Sodalite trachyte............................ 357

Soda niter......................... 235,237,241-246

Soddy, F., origin of helium.................. 302

Sodium, distribution........................ 20

metallic, in salt.......................... 220

sulphate deposits...................... 222-224

Sodium chloride, in rainfall.,................ 50

See also Salt. 

Soellner, J., rhoenite......................... 368

Soils............................... 467,469,475,484

Sokoloff, N. V., origin of petroleum.......... 695

Sollas, W. J., chert and flint................. 519

geologic time............................ 137

order of deposition of minerals........... 292

quartzite................................ 580

Solomon River, analysis of water............ 75

Soltmann, R., melanite...................... 381

Solubility of minerals...................... 454-459

Sommerfeldt, E., classification of igneous rocks 404 

Sommerlad, H., synthesis of chalcostibite.... 631
INDEX. 775

Page. 

Sbmmerlad, H., synthesis of sulphosalts..... 624

sulphosalts of lead....................... 647

Sommermeier, E. E., coal analyses.......... 713

Sondto, K., cited........................... 48,130

Sonnenschein, F. L., amalgam............... 615

Sonstadt, E., caesium and rubidium in sea

water............................ 110

gold in sea water........................ Ill

iodine in sea water....................... 109

Sorby, H. C., calcite and aragonite........... 528

enlargement of quartz grains............. 514

formation of magnesium carbonate....... 537

of siderite and limonite.............. 545

magnesium sulphate in gypsum......... 535

shale.................................... 524

Soret's principle............................. 294

Souesite..................................... 314

Sowetow, S., Sea of Aral..................... 154

Spaeth, E., water analyses................... 89,90

Spalding, E. P., Terlingua mines............ 634

Spaulding, H. S., analyses by.. 70,71,72,73,74,76,77 

Spencer, A. C., iron ores..................... 506

magmatic waters...................... 202,606

Spencer, A. G. See Shutt and Spencer.

Spencer, Herbert, nature of earth's interior... 55

Spencer, J. W., bauxite...................... 473

Spencer, L. J., jamesonite................... 647.

tellurides................................ 616

See also Prior and Spencer. 

Sperry, F. L. See Penfleld and Sperry. 

Sperrylite................................... 672

Spessartite.................................. 380

Spezia, G., formation of quartz and opal..... 344

metallic sodium in salt.................. 220

solubility of quartz...................... 457

sulphur deposits......................... 551

Sphajrite.................................... 496

Sphserocobaltite............................. 663

Sphalerite......................... 639-641,643,644

Sphene...................................... 332

Spica, M., and Halagian, G., Italian waters.. 88 

Spiegel, L., flchtelite......................... 711

Spielmann, P., jet........................... 712

Spilker, A. See Kramer and Spilker.

Spinel..................................... 324-326

Spirek, V., mercury ores..................... 638

Spodumene........................... 360-362, 656

Spreustcin................................... 357

Spring, R., platinum ores.................... 670

Spring, W., argentite formed by pressure.... 621

coloration of clay......................... 484

compression of chalk..................... 531

of peat............................... 726

humus and iron in waters................ 507

precipitation of organic matter by iron... 482 

sedimentation............................ 482

Spring, W., and Prost, E., water of the

Mouse..................... 86, 105, 108

Springs, potable, analyses of................. 60

Spurr, J. E., alaskite and tordrillite.......... 412

borates................................... 234

dolomitization........................... 543

glauconite................................ 547

iron ores................................. 546

magmatic quartz veins................... 615

ore deposits............................ 606, 607

Page. 

Spurr, I.E., primary pyrrhotite............. 317

succession o f igneous rocks............... 296

Srebenica, spring, analysis................... 177

Stabler, H., river waters..................... 63

See also Dole and Stabler. 

Stackmann, A., Lake Durun................. 154

Staflelite..................................... 496

Stahl, A. F., origin of petroleum............. 701

Stahl, W., on Karaboghaz................... 154

zinc sulphide............................. 639

Stanley, F. C. See Penfleld and Stanley. 

Stannite..................................... 652

Stapff, F. M., bog-iron ore. ................... 506

Starnbergersee, analysis of water............. 88

Stassfurt salts.............................. 210-217

Staurolite................................. 390, 585

Steamboat Springs, analysis of............... 175

sinter from............................... 195

Steatite............................... 394, 578, 579

Stecher, E., carbide theory of volcanism.... 267

Steenstrup, K. J. V., graphite in basalt.... 311, 312

Steidtmann, E., alteration of rocks........... 459

Steiger, G., analyses byl............78,113,151,174,

182,220,422,430,439,484,490,503,522,

533,543,544,547,548,570, 579, 587, 588

solubility of minerals..................... 456

synthetic hydrocarbons.................. 691

Sec also Clarice and Steiger. 

Stein, G., formation of quartz................ 342

fusion of quartz and silicates............. 280

Stein, S., artificial coal....................... 728

Steinmann, G., precipitation of calcium carbonate. .......................... 526

Stelzner, A., artificial gahnite................ 642

associates of perofskite................... 332

Bolivian tin ores....................... 652,656

melilite rocks............................ 380

See also Schulze and Stelzner. 

Stelzner, A., and Schertcl, A., tin in blende... 652 

Stelzner, A., and Schulze, H., fayalito in

slags ............................ 370

Stelzner, A. W., lateral secretion........... 600,601

Rio Saladillo............................ 1 153

ore deposits.............................. 599

Step, J., and Becke, F., uranium ores........ 675

Stepanow, , analysis of water............ 154

Stephanite................................. 623^624

Stercorite.................................... 496

Sternbergite................................. 623

Sterrett, D. B. -See Pratt and Sterrett. 

Stevenson, J., primitive atmosphere......... 53

Stibiconite................................... 659

Stibnite................................ 603,657,658

Stieglitz, J., carbon dioxide of the atmosphere.. .......................... 134

Stilbite...................:.................. 395

Stilpnomelane............................... 377

Stockvis, C. S. See Saltet, R. H.

Stober, F., synthesis of cotunnite............ 648

Stokes, H. N., analyses by...... 28,60,178,413,414,

417,419,421,424,427,429,435,438,439,

449,517,522,533,566,583, 588, 592, 604

formation of copper su Iphides............ 630

of sphalerite.......................... 644

precipitation of copper................... 626

of lead sulphide ..................... 646
776 INDEX.

. Page. 

Stokes, H. N., pyrite and marcasite......... 318

solution and deposition of silver........ 620.622

solution of gold........................... 617

tallow clay............................... 644

Stoklasa, J., volcanic nitrogen................ 259

Stolba, F., on the Moldau.................... 90

River Radbuza.......................... 90

synthesis of galena....................... 645

Stolzite.......................'......... 650,667,668

Stone, C. H., analyses of water.............. 70,150

Mississippi silt........................... 481

Stone, G. H., asphalt........................ 687

Storer, F. H. See Warren and Storer.

Storms, W. H., borate deposits.............. 236

Stose, G. W., wavellite....................... 496

Strecker, A. and H., marine mud............ 491

Stremme, H., allophane, halloysite, etc..... 477

coal...................................... 707

decomposition of basalt.............. v .. 459

humus substances....................... 460

kaolinization............................ 468

polymerization of hydrocarbons......... 700

See also Gagel and Stremme. 

Strong, A., bauxite.......................... 473

S trengite.................................... 496

S trigovite................................... 377

Stromeyer, C. E., fusibility and pressure.... 277

Strong, W. W., radioactivity.............. 300,302

Strontium, distribution of.............. 20,552,553

in sea water............................. 110

Strutt, R. J., age of minerals................. 303

gases in rocks............................ 268

helium and geologic time................ 303

helium in saline minerals.............. 212,302

radioactivity of rocks.......... 300,301,302,303

radium in ocean water................... 112

Struvite..................................... 496

Stubbs, W. C., phosphate rock.............. 504

Stutzer, A., and Hartleb, R., bacterial decomposition of cement............... 461

Stutzer, A., and Reich, A., water analysis

cited............................ 156

Stutzer, 0., cobalt ores...................... 660

graphite................................. 311

j uvenile springs.......................... 202

kaolinite................................ 468

magmatic bornite....................... 318

magnetite ores........................... 328

primary calcite.......................... 397

water of pitchstone...................... 271

Stutzite..................................... 622

Stylotypite.................................. 630

Suess, E., vadose and juvenile waters...... 202,606

volcanic additions to oceanic salts....... 129

Siissenguth, H., cited....................... 90,481

Suez Canal, analysis of water................ 113

Sullivan, E.G., copper sulphides............ 630

deposition of copper..................... 633

Sullivan, G. See Kastle, J. H., etc.

Sulphates, reduction by microorganisms.... 102,

136,137,491,551 

Sulphates in sea water..................... 127,128

Sulphoborite.............................. 214,238

Sulphohalite...... -.......................... 235

Sulphur, distribution........................ 20

in atmosphere........................... 44

PageSulphur in petroleum......................... 686

native .................... 211,235,257,550-552

Bank, analyses of waters from........... 186

Sulvanite.................................... 674

Sungi Pait, Brook, analysis of water......... 188

Superior, Lake, analysis of water............ 64

Susquehanna River, analysis of water....... 66

Sutton, J. R., diamond...................... 309

Svanberg, , analyses by................. 669

Svedmark, E., urahtization.................. 564

See also Tornebohm and Svedmark. 

Svendseu, S., analyses of dissolved air........ 131

Sweden, rivers of............................ 94

Swinton, A. A. C., occlusion of gases by

glass ............................ 269

Switzerland, lakes of......................... 87

Syenite........................ 416-419,422,424,425

Syepoorite. See Jaipurite.

Sylvanite.................................... 616

Sylvinite.................................... 213

Sylvite................................ 213,214,217

Syngenite................................... 215

Syntagmatite................................ 367

Syracuse, N. Y., brine, analyses of........... 171

Szab6, J., primary iolite..................... 385

Szadeczky, J. von, bauxite.................. 473

Szajnocha, , origin of petroleum........ 698,703

Szathmary, L. von,. wollastonite............. 359

T.

Taal Volcano, analyses of water from........ 189

Taber, S. See Watson and Taber.

Taboury, F., selenium in spring waters...... 173

Tachhydrite................................. 213

Tacke, B. See Minssen and Tacke.

Tagar, Lake, analysis of water............. 159,163

Tahoe, Lake, analysis of water............... 147

Takano, S. See Mabery and Takano.

Taibot, J. H. See Binney and Talbot.

Talc................................... 394,575-579

Tallow clay.................................. 644

Tahnage, J. F., water analyses............... 144

Tamentica, Lagoon, analysis of water...... 153,163

Tanatar, S., origin of alkaline carbonates.... 230

Taney, Lac.................................. 87

Tantalite.................................... 678

Tantalum, distribution of.................. 20,678

native....'............................... . 678

sources of................................ 678

Tapajos, River, analysis of water............ 83,98

Tapalpite................................... 623

Tappeiner, H., formation of marsh gas...... 697

'Tarassenko, W., constitution of feldspar..... 346

Tasmanite................................... 713

Tate, N., analysis of water................... 64

Taylor, F. W., analysis by.................. 219

Taylor, H., analysis of cannel............... 717

Taylor, R. A., cited......................... 128

Taylor, W. H., analysis of water cited....... 67

Teall, J. J. H., classification of igneous rocks.. 403 

dedolomitization......................... 596

differentiation........................... 297

eutectic mixtures in rocks......... 288,401,402

origin of serpentine...................... 394

phosphatized trachyte................. 497,498

the Scourie dike....................... 563-564
INDEX. 777

Page. 

Teallite.................................... 647,652

Tegernsee, analysis of water................. 88

Tehamose................................... 413

Teisseyre, W. See Mrazec and Teisseyre. 

Tekir-Ghiol, Lake, analysis of water....... 161,162

Tellurides..... 615,616,622,623,628,634,645,657,660

Tellurium, distribution...................... 20

in copper................................ 628

in sulphur............................... 257

Tengerite.................................... 680

Tennantite................................ 623,631

Tennessee River, analysis of water........... 73

Tenorite................................... 258,632

Tephroite................................... 370

Terbium................................... 20,679

Terlinguaite................................. 634

Termier, P.,alunite......................... -247

lawsonite................................ 391

leverrierite.............................. 584

optical variations in zoisite.............. 386

riebeckite rocks......................... 369

Terreil, A., artificial dolomite............... 536

native platinum......................... 669

water analyses.......................... 156

Tesch, P., solubility of fossils................ 528

Tetlow, W. E., water analysis............... 85

Tetradymite................................ 657

Tetrahedrite.......................... 623,631,634

Thallium, distribution...................... 20

Thames, River, analysis of water............ 85,98

Than, C. von, ionic statement of water analyses ............................. 57

Thenard, P., silico-azo-humic acid........... 98

Thenardite............................ 235,237,243

Theralite.................................... 422

Thermonatrite.............................. 227

Thicle, F. C., Texas petroleum.............. 685

Thiene, H., nature of earth's interior........ 39,55

Thinolite.................................... 148

Thiophanes................................. 686

Thiosulphates in spring waters.............. 184

Thoma, , gases in iron................... 273

Thomas, J. W., gases in coal............... 723-725

Thomas, P., phosphorite.................... 501

Thompson, A. B., formation of bitumens.... 702

Thomson, J., thermochemistry of sulphides.. 622 

Thomson, J. A., matrix of diamond......... 308

Thomson, R. D., cited...................... 85

Thomsonite................................. 395

Thorianite.................................. 679

Thorite..................................... 678

Thorium, distribution....................... 20

in rocks................................. 300

sources of............................. 678,679

Thorkelsson, T., hot springs of Iceland...... 249

Thorogummite.............................. 680

Thorpe, T. E., analyses by............ 173,175,176

Thorpe, T. E., and Morton, E. H., analysis of

sea water........................ 112

Thoulet, J., chert........................... 519

desert sand.............................. 479

lakes of the Vosges...................... 85

sedimentation........................... 482

solubility of calcium carbonate.......... 117

of silicates........................... 121

Page. 

Thresh, M., manganese nodules.............. 508

Thiirach, H., occurrence of zircon and titanium minerals................. 334,336

Thugutt, S. J.,allophane, halloysite, etc..... 477

alteration of corundum.............:.. 323,457

cancrinite............................... 356

composition of sodalite................ 355,356

gibbsite and diaspore.................... 474

leucite and analcite.................... 350,351

reactions of calcite and aragonite........ 527

Thulium................................... 20,079

Thuringite................................ 377,549

Tidy, C. M., water analyses cited............ 85

Tiemannite................................. 634

Tietze, E., atmospheric transport of salt..... 51

Tietze, 0., phosphorite...................... 501

Tilden, W. A., gases in rocks.............. 261,262

Tillo, A. von, areas of igneous and sedimentary rocks....................... 108

Tilson, B. S.,cited.......................... 71

See also Fraps and Tilson. 

Tin, distribution............................ 20

in sinter................................. 195

ores................................... 652-056

Tinetzky Lake, analysis of water............ 154

Tinguaite................................. 420,424

Tinstone. See Cassiterite.

Titanite..................................... 332

Titanolivine................................. 370

Titanium, distribution...................... 20

Tornebohm, A. E., melilite rocks............ 380

Tornebohm, A. E., and Svedmark, E., scapolito rocks....................... 570

Tornebohm, A. S., enlargement of quartz

grains........................... 514

Tolman, C. F., jr., oceanic carbonic acid.... 134

Tolomei, G., iron bacteria................... 506

Tombigbee River, analysis of water......... 68

Tonalite..................................... 433

Tonalose.................................. 430,438

Tookey, C., analyses by............... 709,712,714

Topaz....................................... 388

Torbanite................................... 700

Tordrillite...'................................ 412

Tornoe, H., density of sea water............. 114

analyses of dissolved air............... 131,133

Torrico y Meca, vanadium in coal............ 673

Torrey, J. See Barbour and Torrey.

Toscanose......................... 414,415,428,429

Tourmaline........................... 392,393,589

Tourmaline hornstone..................... 589,590

Trachyte.................................... 416

Transition temperatures..................... 281

Transvaalite................................. 663

Traphagen, W., cited........................ 73

Traube, H., sublimation of minerals......... 260

synthesis of beryl........................ 393

of rutile............................. 333

wurtzite as furnace product.............. 639

zincite...........................'........ 641

See also Bourgeois and Traube. 

Traunsee, analysis of water.................. 88

Travaglia, R., formation of sulphur deposits. 551 

Travers, M. W., gases from meteorites....... 273

gases from minerals and rocks........... 262
778 INDEX.

Travertine............................ 192,524,525

Tread well, F. P., and Reuter, M., solubility of

calcium bicarbonate............. 117

Trechmann, C. O., pseudogaylussite......... 148

Tremolite................................... 364

melting point............................ 279

Trener, G. B., genesis of barite.............. 555

Tridymite................................. 339-344

Trinkerite.................................... 713

Triphylite................................... 654

Tripuhyite.................................. 659

Trobridge, F. G., gases in coal............... 726

Troilite...................................... 316

Trona................................. 227,228,235

Troost, L. See Deville and Troost. 

Troost, L., and HautefeuiJle, P., gases in iron. 273 

Truchot, P., monazite, thorite, and zircon... 339 

Truckee River, analysis of water............ 147

Tschermak, G., alteration of atacamite...... 632

carbon in meteorite...................... 695

constitution of pyroxenes................ 364

composition of tourmaline............... 392

gaseous occlusions..................... 273,274

scapolite group........................ 383,571

serpentine............................... 575

theory of chlorites..................... 377,378

of micas............................. 374

Tschirwinsky, W., podolite.................. 338

Tsuneto, K., Japanese phosphates........... 504

Tucan, F., dolomitization................... 538

Tucker, G. P. See Pemberton, H.

Tufa, barytic........^....................... 193

Tufa, calcareous........................ 192,524,525

Tulare Lake, analyses of water............ ISO, 165

Tungsten, distribution...................... . 21

ores................................... 666-668

Tungstic ocher............................... 667

Tuolumnose................................. 416

Turgite...................................... 504

Turner, H. W., California diamonds......... 310

quartz-alunite rock.......'............. 247,474

Turquoise................................... 496

Tuscarora sour spring, analysis.............. 187

Tyrolite..................................... 632

Tychite..................................... 235

Tyrrell, G. W., analcite rocks................ 352

Tyrrell, J. B., native iron.................... 315

Tysonite.................................... 319

U.

Ubbelohde, L., optical activity of petroleum. 703 

Udden, J. A., aerial denudation............. 126

Uhlig, J., kryptotile and prismatine....... 374,584

Uintaite..................................... 687

Ule, W., the Mansfelder lakes................ 87,93

Ulexite............................ 234,237,238,240

Ulke, T., tin deposits........................ 655

Ullik, F., on the Elbe...................... 90,108

Ullmannite.................................. 600

Ulrich, E. O. See Hayes and Ulrich.

Ulrich, E.G., and Smith, W. S. T., fluorite... 556

Ulrich, G. H. F., awaruite................... 314

Umangite................................... 628

Umlauff, A. F., mercury deposits............ 638

Umptekoso.................................. 422

Page. 

Unakite................................... 309,572

Uralite............................:....... 365,564

Uralitization.............................. 563,564

Uralose...................................... 444

Uraninite.................................... 675

Uranium, distribution....................... 21

ores of................................. 672-678

See also under radioactivity. 

Urao. See Trona. 

Urbain, G., rare earths in fluorite............ 319

rare metals in blende.................... 638

yiterbium............................... 21

Urbas, M., silicate fusions................... 291

Urmi, Lake, analysis of water............ 158.162

Urtite..................................... 422,423

Urtose....................................... 422

Uruguay River, analysis of water............ 83.98

silica in.................................. 99

Usiglio, J., concentration of sea water..... 207-209

Ussing, N. V., alteration of arfvedsonite.... 369

Utah Hot Springs, analysis.................. 172

Utah Lake, analyses of water................ 145

Uvaldose.................................... 436

Uvarovite................................... 381

V. 

Vaalose...................................... 439

Vadose waters............................... 201

Valentin, J., fluorite......................... 556

Valentine, W., analysis by.................. 449

Valentinite.................................. 659

Van, Lake, analysis of water............... 158,165

Vanadinite................................ 650,674

Vanadium, distribution.................... 21

in bauxite............................... 476

in bitumen............................ 674,689

in salt clay.......................... 211,673

ores of................................. 672-678

Van Hise, C. B., actinolite magnetite schist. 365 

alterations of corundum................ 323

of hematite.......................... 330

amount of carbon dioxide in atmosphere. 45 

average composition of clays, schists,

etc............................. 592,593

chert.................................... 520

ferruginous schists.........:............. 582

fineness of sand particles................. 524

formation of iron ores.................... 546

magmatic quartz veins................. 615

magmatic waters........................ 606

mica schist.............................. 588

ore deposits............................ 599,606

origin of magnetite...................... 329

porosity of sand........................ 514

quartzite................................ 580

relative proportions of sedimentary rocks. 29,31 

volume changes in alteration of minerals. 563 

volume of ground water................. 33

zinc deposits............................. 644

zones in lithosphere.................... 558-560

See also Irving and Van Hise. 

Van Horn, F. B., alkali-hornblende........ 367

Van Nuys, T. C., and Adams, B. F., cited... 44 

Van Rieseu. , analysis by............... 579

Van't Hoff, J. H., geological thermometer... 216 

on Stassfurt salts..................... 213-217
INDEX. 779

Page. 

A^an't Hoff, J. H., syntheses of borates...... 236

Van't Hoff, J. H., and Barschall, H.. on

glaserite......................... 212

Van't Hoff, J. H., and Farup, P., marine

anhydrite....................... 215

Van't Hofl, J. H., Kenriclc, F. B., and Dawson, H. M., tachhydrite.......... 214

Van't Hoff, J. H., and Meyerhoffer, W., on

langbeinite.................... 213,214

Van't Hoff, J. H., and Weigert, F., formation

of anhydrite..................... 215

Vanthofflte................................ 212,217

Van Wagenen, T., soda niter................ 240

Van Winkle, W., analyses by................ 09,

70, 71, 72, 73, 74, 70, 77, 79, 150 

Van Winkle, W., and Eaton, F. M., waters of

California........................ 03.78

Variscite.................................. 490,498

Varon, G. See Henriot and Varon.

Varvicite.................................... 509

Vasculose.................................... 727

Vater, H., alkaline carbonates................ 230

anhydrite............................... 215

artificial hematite....................... 329

calcite andaragonite..................... 527

Vaughan, T. W., fuller's earth............... 484

precipitation of calcium carbonate....... 525

Vauquclinite................................ 050

Vaux, F., coal analyses................ i... 717,719

Veatch, J. A., boron in sea water............ HO

Vegetation, as agent of rock decomposition. 459,400 

Veins, metalliferous....................... 607-013

Velain, C., artificial tridymite .............. 341

volcanic gases ........................... 255

Venable, F. P., on periodic law.............. 36

Venanzite................................. 435,4.30

Venanzose................................... 436

Verde-antique............................... 595

Vermiculite................................. 370

Vermilion................................... 035

Vernadsky, W., andalusite, kyanite, sillimanite............................... 584

 artificial corundum...................... 323

calcination of dumortierite............... 392

of topaz............................. 388

formation of sillimanite.................. 388

of spinel............................. 325

fusion of muscovite...................... 370

rare elements in rocks................... 27

Vernadsky, W. S., and Popoff, S. P., borax.. 238 

Vernon-Harcourt, L. V., sedimentation..... 482

Versailles alum well, analysis................ 177

Vesterberg, A.., dolomite and magnesite...... 539

Vesuvianite.................................. 383

Veszelyite................................... 641

Vetter, F., deposition of calcium carbonate.. 193 

Vichy, spring deposits..................... 193,194

Vichy waters, analysis....................... ISO

Vierthaler, A., cited......................... 112

Viezzcnose.................................. 422

Villarello, J. D., mercury ores............... 634

Ville, L., River Chew....................... 62

Villiaumite.:...........................'..... 354

Vils, River, analysis of water................ 92

Vinagrc, Rio, analysis of water.............. 188

Viola, C., occurrence of lawsonite............ 391

Page. 

Violette, , charcoal...................... 726

Virginia Hot Springs, analysis............... 182

Viridite..................................... 574

Viry phosphatic water, analysis............. 186

Vistula River, analysis of silt................ 481

analysis of water......................... 94

Vivianite.................................. 496,505

Voelckcr, J. A., composition of apatite....... 330

Vogel, H., platinum in metallic ores......... 072

Vogelsang, H., viridite...................... 574

Vogt, J. H. L., anorthite in slags............ 346

apatite in slag........................... 337

angite in slags........................... 363

bog-iron ore............................. 506

cassiterite as a furnace product........ 335,052

chromitedeposits...................... 327,666

distribution of the elements............. 27,38

of vanadium......................... 673

eutectic mixtures in rocks......... 288,289,343

eutcctics in classification of rocks...... 401,402

formation of hematite................... 330

of magnetite......................... 328

of pyroxene......................... 300

fusion of garnet.......................... 381

gehlenite group.......................... 379

ionization in magmas.................... 292

magmatic iron ore....................... 297

magmatic pyrrhotitc..........'.... 317,318,601

magmatic waters........................ 606

manganese ores.......................... 510

melting points of minerals......... 277,278,279

mica in slag............................. 374

native silver............................. 020

olivine in slags........................... 370

on assimilation theory................... 295

ore deposits........................... 599, COG

platinum in pyrrhotite.................. 672

solubility of sulphides in magmas...... 291,317

synthetic enstatite....................... 358

tin deposits.............................. 655

wollastonite in slags..................... 359

Vohl, H., water analysis..................... 89

Voit, F. W., nickel deposits................. 662

. origin of diamond....................... 308

Volborthite................................. 674

Volcanic gases ............................ 248-270

Volcanic explosions........................ 271-275

Volcanic mud and sand................... 488-489

Volcanism, ascribed to radioactivity....... 301,302

hot springs and.......................... 202

Voltzite...................................... 039

Vouga, , origin of petroleum............. 700

Vredenburgite.............................. 510

Vuinik, M., formation of angite............. 363

formation of hercynite................... 326'

of magnetite......................... 328

fusion of acmite......................... 361

of mineral mixtures............... 286,291

Vukits, B., formation of augite.............. 363

formation of magnetite.................. 328

of spinel............................. 325

fusion of m ineral mixtures............. 280,291

Wabash River, analysis of water. 

Wad............................
780 INDEX.

Wade, H. R. See Failyer, G. H.

Wadsworth, M. E., chromite................ 326

native copper........................... 626

Waggaman, W. H. See Patten and Waggaman. 

Wagner, P. A., diamond.................... 308

Wagoner, L., gold and silver in rocks........ 613

gold in sea water........................ Ill

 Wahl, W. H., composition of meteorites..... 39

Waidner, C. W., and Burgess, G. K., temperature of electric arc........... 260

Wait, C. E., antimony deposits.............. 658

Wait, F. G., analyses by........... 80,151,174,180

Wakarusa River, analysis of water.......... 75

Walchensee, analysis of water............... 88

Walden, P., origin of petroleum............. 702

Walker, P. H., analysis by.................. 509

Walker, T. L., magmatic differentiation..... 297

nickel deposits........................ 661,662

Walker Lake, analysis of water............ 147,165

Walker River, analysis of water............. 147

Wallace, E. C. See Richardson and Wallace. 

Wallace, R. C., silicate fusions............... 286

Wallace, W., sandstones..................... 517

Waller, E., analyses by.................... 144,326

Waller, S. A., and Twelvetrees, W. H., tin

deposits......................... 654

Wallich, G. C., flint......................... 519

Walter, H. See Wegscheider and Walter. 

Walther, J., calcareous algae................. 530

criticism of Ochsenius................... 209

desert salts......'........................ 224

origin of graphite........................ 310

laterite.................................. 470

Walther, P., native tantalum............... 678

Wanklyn, J. A., free iodine in spring water.. 172 

Ward, L. K., tin deposits................... 654

Ward, W.'J., analysisby.................. 712,714

Wardlte..................................... 496

Warington, R., absorbent power of hydroxides. .......................... 477,478

ammonia in rainfall..................... 49

chlorides in rain......................... £0

decomposition of calcium phosphate.... 49G

origin of boric acid...................... 233

sulphur in the atmosphere............... 44

Warren, C. H., anorthite in limestone....... 349

iron-anthophyllite.................... 364,372

minerals in sand......................... 480

See also Hidden and Warren, Johnson and

Warren. 

Warren, C. M., and Storer, F. H., artificial

petroleum....................... 692

Rangoon oil............................. 085

Warrenite................................... 647

Warsaw, N. Y., brine, analysis of............ 171

Warth, H., calcium carbonate............... 527

classification of igneous rocks............ 400

gibbsite................................. 471

Warth, H. and F. J., laterite and bauxite.... 471

Washington, H. S., alteration of biotite..... 375

analcite in tinguaite..................... 352

analyses by.................... 424,426,436,566

average composition of igneous rocks..... 24

distribution, c f the elements............. 38

Page. 

Washington, H. S., glaucophane rocks....... 369-

kaersutite and linosite .................. 369

leucite in igneous rocks................ 351,425

quantitative classification............. 410,411

relative abundance of minerals.......... 398

See also Kunz and Washington. 

Washington,H.S.,and Wright, F. E., carnegieite......................... 345

Water,influence of,'on magmas........... 282,283

Water analyses, statement of................ 57

Wateree River, analysis of water............ 68

Water glass................................. 283

Waters, classification of................... 162-165

Waters, J. W., radioactive minerals......... 300

Watson, H. E., helium and neon in air...... 40

Watson, T. L., barite....................... 555

bauxite............................... 472,473

decomposition of diabase................ 464

manganese ores.......................... 510

Virginia rutile........................... 334

zinc deposits. .......'.................... 644

Watson, T. L., and Taber, S., nelsonite.... 334,445-

Watts, W. L., waters accompanying petroleum. ........................... 700

Wauters, C., cited.

Wavellite................................... 496

Way, J. T., absorption of potassium by soils.. 477 

Wayne, E. S., analysis by................... 172

Weathering, belt of.......................... 558

Weber River, analysis of water.............. 145

Websky, J., analyses of peat................. 70S

gas from peat-........................... 723

Webskyite.................................. 394

Websterite................................ 440,441

Websterose.................................. 441

Wedd,C. B.,baryticsandstones............. 515

Wedd, C. B., and Drabble, G. C., fluorspar.. 55& 

Wedding, H., and Fischer, T., gases in iron.. 273 

Weed, W. H., copper ores................... 629

gold in igneous rocks.................... 316

iron sinter............................... 546

on siliceous sinters..................... 195,196

ore deposits........................... 599,607

secondary enrichment................... 611

tin deposits............................. 655

travertine............................... 526

Weed, W. H., and Pirsson/L. V., alteration

of leucite to analcite............ 352

origin of corundum...................... 323

orpiment and realgar.................... 657

Weeks, F. B., tungsten ores................. C68

Weeks, F. B., and Ferrier, W. F., phosphate

rock............................. 503

Weeks, J. D., manganese deposits........... 510

Weems, J. B., lead and zinc in limestones.... 643

Wegscheider, R., and Walter, H., gaylussite

and pirssonite................... 235

Wehrlite.............................. 440,441,657

Wehrlose.................................... 441

Weibull, M., formula of iolite................ 385

manganese in spring water.;............. 194

vesuvianite.............................. 383

Weidman, S., iron ores...................... 546

Weigand, B., serpentine..................... 575

Weigel, 0., solubility of sulphides........... 603
INDEX. 781

Page.

Weigert, F. See Van't Hoff and Weigert. 

Weingarten, P. See Jannasch and Weingarten. 

~VVeinschenk, E., constitution of pyrite....... 318

garnet group............................ 381

nickel ores............................... 662.

nontronite............................... 468

origin of graphite...................... 310,311

serpentine............................... 575

synthesis of apatite...................... 337

of argentite.......................... 621

of chalcocite and covellite............ 629

of cinnabar.......................... 638

of galena............................ 646

of orpiment and stibnite............. 657

sulphides of cobalt and nickel........... 661

talc pseudomorphs...................... 578

Weiss, F., origin of kaolin................... 468

Weiss, K. E., chromite deposit.............. 666

Weisswasser, analysis of water............... 90

Weld, C. If., iron ores....................... sofi

Weljcome, H. S., analysis of salt............. 219

Weller, A., nitrogen in petroleum........... 686

Wells, G. M., phosphate rock................ 502

Wells, H. L., sperrylite...................... 672

Wells, H. L., and Penfleld. S. L.,sperrylite.. 672

Wells, J. W., arsenic mine................... 659

molybdenite............................ 667

Wells, R. C., copper in basalt............... 602

mine water.............................. 604

precipi tation of sulphides................ 612

vanadium in asphalt.................... 674

Wellsite..................................... 395

Welsbach, Auer von, ytterbium............. 21

Wendeborn, , mercury deposits......... 638

Weudt, A. F., tin deposits.................. 056

Werner and Fraatz, samsonite.............. 623

Wernerite................................. 383,571

Werveke, L. van, occurrence of chloritoid... 376

iron ores................................. 549

Weser River, analysis of water.............. 94

Westgate, L. G., epidote-quartz rock........ 572

metamorphosed limestone............... 596

Westphal, J., cited, on Stassfurt salts........ 210

West Baden Spring, analysis................ 178

Wethered, E. B., oolite...................... 525

Weyberg, Z., synthesis of acmite............ 361

of sodalite......................... 355,356

Wheeler, A. S., analyses of sea water........ 113

Wheeler, H. A., blende in lignite............ 640

clays.................................... 484

lead silicate............................. 651

See also Luedeking and Wheeler.

Whewellite.................................. 708

Whipple, G.C.,cited........................ 50

Whitby well, analysis....................... 174

White, A. F., chemical denudation......... 67,103

White, C. J., ocean water.................... 112

White, I. C., grahamite...................... 688

White, J., barium in artesian water......... 193

White, W. P. See Alien and White.

White Island hot lake, analyses of water..... 189

White River, analysis of water.............. 72

White Sea, analysis of water................. 113

Whitfleld, J. E., analyses by...'............. 192,

194,195,196,413,430,441,544

Page. 

Whitney, J. D., zinc deposits................ 644

Whitneyite.................................. 628

Whittle, C. L., ottrelite schist............... 586

Wibel, E., cited............................. 112

Wiqhmann, A., alteration of iolite.......... 386

glaucophane rock........................ 565

minerals in sand......................... 479

 sericitic rocks............................ 567

 Wiegand, E. Set Beilstein and Wiegand. 

Wieland, G. R., silicious oolite.............. 520

Wiesbaden, analysis of water................ 173

Wieslcr, A., gold in sea water................ Ill

Wilder, F. A., gypsum...................... 220

WilMnson, C., precipitation of gold.......... 619

Will, W., and Pinnow, ,T., diamonds in

meteorite........................ 308

Willamette River, analysis of water......... 78

Willemite......................... 641,642,644,645

Williams, A., gold sulphide................. 614

Williams, C. P., zinc in waters.............. 604

Williams, F. H., hydrocarbons in iron....... 690

Williams, G. F., matrix of diamond..'..... 308,309

Williams, G. H., allanite and epidote........ 380

chloritization............................ 574

corundum, emery, and spinel............ 322

epidotization............................ 571

occurrence of magnetite................. 328

of perofskite......................... 332

of pyroxenes........................ 364

of spinel............................. 320

piedmontite in rhyolite.................. 387

saussurite rocks......................... 596

sericitization.......................... 567,568

serpentine from peridotite............... 394

uralitization........................... 563,564

Williams, I. A., clays........................ 484

micrometric analysis of rocks............ 451

Williams, J., cited........................... 49,50

Williams, J. F., bauxite..................... -474

pseudoleucite............^............... 352

See also Brackett and Williams. 

Williams, K. See Ebaugh and Williams. 

Willis, B., cited............................ 70,526

Willm, E., analyses by.................... 162.184

See also Jacquot and Willm. 

Willyamite.................................. 660

Wilm, , palladium gold.................. 615

Wilmington Lake, analysis of water....... 152,165

Wilsmore, N. T. M. See Craig, A. W. 

Wiluite..................................... 383

Winchell, A., cosmical atmosphere.......... 52

Winchell, A. N., chalcopyrite and bornite... C28 

origin of graphite........................ 311

Winchell, H. V., chalcocite.................. 630

Winchell, N. H., and H. V., iron ores....... 546

Winkler, C., origin of nickel-iron............ 313

trona.................................... 228

uranium in coal......................... 678

Winnemucca Lake, analyses of water...... 147,165

Winslow, A., zinc ores....................... S48

Wisconsin River, analysis of water.......... 71

Witt, H. M., river water.................... 85

Witter, F. M., gas well...................... 696

Wittich, E., cassiterite...................... 653

Wittichenite................................ 630

Wittjen, B. See Precht and Wittjen.
782 INDEX.

Page. 

Wittstein, G., water analysis................ 91

Woehler, F., carbon in meteorites........... 695

gases from meteorites.................... . 274

Sec also Deville and Wohler. 

Woehler, L., and Kasarno wski, color of salt.. 220 

Wohlerite................................... 363

Woernitz, River, analysis of water........... 92

Wolf, T., volcanic gases.....................' 254

Wolfachite.................................. 660

Wolfbauer, J. F., water of the Danube...... 92,93

Wolfl, F. von, volcanism and radioactivity.. 302 

Wolff, J., artificial diamond................. 307

waters of Mecklenburg.................. 93

Wolff, J. E., Franklin zinc ores.............. 645

ottrelite................................. 586

Wolframite................................ 667,668

Wollastonite.......................... 358,359,594

Wollastonitc gneiss.......................... 597

Wolle, C. A., analysis of spinel.............. 324

Wood................................. 705-708,721

Wood, A. See Campbell and Wood.

Woodward, R. S., geodetic data............. 22

Woodward, R. W., analyses by............. 146,

192,195,224,225,520 

Wooten. See Magnenat and Wooten. 

Workman, R., primary calcite............... 397

Wright, A. W., gases from meteorites....... 272

gases in rocks............................ 261

See also Hawes and Wright. 

Wright, F. E., crystallized copper and silver. 627

See also Alien, E. T.,and Shepherd, E. S. 

Wright, F. E., and Larsen, E. S., quartz as

geologic thermometer........... 342

Wiist, E., kaolin............................ 468

Wulf, H., scapolite rock..................... 571

Wulf, J., wollastonite rock.................. 359

Wulfenite.................................. 650,666

Wiilfing, E. A., composition of tourmaline... 392 

Wurmsee, analysis of water................. 88

Wurtz, H., analysis of water cited........... 66

huntilite and animikite.................. 621

solvent of gold........................... 617

Wurtzilite.................................._ 537

Wurtzite.................................. 639,640

Wyatt, F., phosphates...................... 501

Wyomingite................................. 424

Wyomingose................................ 424

Wyroubofl, G., Heigen's reaction............ 527

Xanthitane.................................. 333

Xanthoconite............................... 623

Xanthophyllite............................. 373

Xanthosiderite.............................. 504

Xenon.................................. 21,40,169

Xenotime...............................'.. 338,679

Xingu, River, analysis of water.............. 83,98

Yamasaki, N., piedmontite.................. 347

Yeates, W. S., copper pseudomorphs........ 626

Page.

Yellowstone National Park, analyses of waters..................... 74,182,185,188:

spring deposits................ 192,194,195,196

Yellowstonose............................... 430

Yeneseisk, Siberia, saline lakes.............. 159

Yogoite..................................... 428

Young, A. A., enlargement of quartz grains . 514 

Young, B. R., analcite diabase.............. 352

Young, G. See Irvine, R.

Ytterbium................................. 21,679

Yttrialite.....................'............... 680

Yttrium, distribution....................... 21

sources of.............................. 679-680'

Yttrocerite.................................. 319

Yttrocrasite................................. 680'

Yukon River, analysis of water.............. 78

Z. 

Zaleski, S. S., cited.......................... 95

Zalinski, E. R., thuringite and chamosite.... 549'

Zaloziecki,-R., formation of petroleum..... 699,703

mirabilite............................... 216-

Zaloziecki, R., and Hausmann, J., Roumanian petroleum.................. 685

Zaloziecki, R., and Klarfeld, H., optical activity of petroleum.............. 703-

Zambonini, F., akermanite.................. 379

gehlenite group.......................... 379

molybdosodalite......................... 355

pseudonephilite......................... 353

sublimed galena......................... 258

Zaracristi, , Colombian nitrates.......... 244

Zaratite..................................... 66i

Zeiller, R., compression of peat.............. 726

paper coal............................... 714

Zelinsky, N., cited.......................... 102

Zemcuzny, S., eutectics....... j.............. 402

Zemjatschensky, P. A., hydrogoethite...... 504

Zem-zem, analysis of water.................. 186

Zeolites.................................... 395,396

Zepharovichite.............................. 496

Zietrisikite.................................. 687

Zillaruello, A., Chilean nitrates.............. 242

Zilliacus, A., analysis by.................... 422

Zinc, distribution........................... 21

in sea water............................. Ill

ores of................................. 638-645

Zincalummite............................... 641

Zincite................................ 641,644,645

Zinkenite................................... 647

Zinnwaldite................................. 372

Zircon...................................... 336.678

Zircon pyroxenes............................ 363

Zirconium, distribution..................... 21

sources of................................ 678

Zitowitsch, , gases in coal................ 723

Zoisite..;.................................... 386

Zoisite rocks................................. 570

Zorgite...................................... 645

Zschimmer, E., alteration of micas.......... 376

Zuber, R., origin of petroleum............... 697

Zulkowski, K., andalusite group............ 389

Zurich, Lake of, analysis of water............ 89

o