Bulletin *?9r :-ft£O Series E, Chemistry and Physics, 54

DEPARTMENT OF THE INTERIOR

UNITED STATES GEOLOGICAL SURVEY

GEORGE OTIS SMITH, DIKECTOB

THE

DATA OF GEOCHEMISTRY

BY

FRANK WIGGLESWORTH CLARKE

WASHINGTON

GOVERNMENT PRINTING OFFICE

1908

CONTENTS.

Page.

INTRODUCTION. _______________________________ 0

CHAPTER I. The chemical elements______________________ 12

Nature of the elements________^_____________...._ _ 12

Distribution of the elements___________________.._..__ 13

Relative abundance of the elements_________________ 2.1.

CHAPTER II. The atmosphere__________________________ 3S

Composition of the atmosphere______________________ 38

Rainfall _______________________________.______ 44

The primitive atmosphere_______________________ 49

CHAPTER III. Lakes and rivers__________________________ 53

Origin ____________!_..________.________________ 53

Statement of analyses_..______._________________ 54

Springs _________________.._________________ 56

Changes of composition_______.._..________________ 57

Analyses of river waters__________________________ GO

The St. Lawrence basin________________________ 60

The Atlantic slope__________________________ 62

The Mississippi basin___________________________ 64

Southwestern rivers______________:'_______.___ 69

The Pacific slope____________________________ 70

The Saskatchewan system_____._______________ 71

Summary for North America..,__.._____________.___ 72

Rivers of South America___._____________________ 73

Waters of western Europe___'________________ 75

Rivers of central Europe_______________________ 76

Rivers of Sweden__________________._________ SO

Russian waters __________________ _ ________ 81

The Nile _________________________________ 82

Organic matter in Avaters___r_ __ _ _ __ ______ 82

Contamination by human agency- _ _ ______ 84

Gains and losses in waters _ 86

Chemical denudation 87

CHAPTER IV. The ocean_____ ___ _ 91

Elements in the ocean__ 91

Composition of oceanic salts___-__ 94

Carbonates in sea water 98

Oceanic sediments ____________ 100

Potassium and sulphates___ 106

The chlorine of. sea water_ __ ___ 107

Age of the ocean_______ 109

Dissolved gases ____ .- . 110

Influence of living organisms 115

3
4 CONTENTS.

Page.

CHAPTER V. The waters of closed basins_____________________ 118

Preliminary statement ____________________________ 118

The Bonneville basin_________________.._____________ 118

The Lahontan basin_.__________________________ 121

Lakes of California______=___._____..____________.__ 124

Northern lakes _____________________..___:______ 125

Central and South America______________________'._____ 126

Caspian Sea and Sea of Aral__________________________ 127

The Dead Sea____________________:____________ 128

Other Russian and Asiatic lakes____ ________________ 130

Miscellaneous lakes __________________ ___________ 132

Summary _____________________________________ 134

CHAPTER VI. Mineral wells-and springs__^_____ __________ 130

Definition ______________:_____________________ 130

Classification __________________________________ 140

Chloride waters_,_____________________________ 141

Sulphate waters________________________________ 145

Carbonate waters_______________________________ 140

Waters of mixed type____-.________________________ 150

Siliceous waters_________________________=______ 151

Nitrate, phosphate, and borate waters___________________ 153

Acid waters______________________________ 155

Summary of waters____________:________________ 157

Changes in waters_____________________,______ 158

Calcareous sinter __ _ _________________________ 159

Ocherous deposits-_________________________..___ 160

Siliceous deposits____________1_________________ 161

Reactions with adjacent material______.._____________ 164

Vadose and juvenile waters- -..,_______ _______.. ___ 168

Thermal springs and volcauism_______________________ 168

Bibliographic note________________________________ 170

CHAPTER VII. Saline residues ______,. _- __ 172

Deposition of salts______:__________________________ 172

Concentration of sea water_________________ _____ 173

The Stassfurt salts_____________________________ 176

Other salt beds_______..__ ________________________ 182

Analyses of salt______ . 183

Analyses of gypsum _1 184

Bitterns___ - 184

Sodium sulphate__ _ ___..__ 186

Miscellaneous desert salts __ 188

Alkaline carbonates - ISO

Borates __ -- 105'

Nitrates ______ 205

Alums _ __ 211

CHAPTER VIII. Volcanic gases and sublimates_________________ 212

Gaseous emanations 212

Sublimates___ 220

Occluded gases - 224

Volcanic explosions--_ -_ _______ 232

Summary LI 236
CONTENTS. 5

Page.

CHAPTER IX. The molten magma______________________:_ 238

Temperature ______________________________ 238

Influence of water______________________________ 243

Magmatic solutions_______________________________ 244

Eutectics _____________________________________ 247

Separation of minerals_'. _________________________ 250

Differentiation _______________________________ 253

Radioactivity __,.____________..________________ 259

CHAPTER X. Rock-forming minerals________________._______ 261

Preliminary statement______________ ______________ 261

Diamond and graphite____________________________ 262

Native metals___________________________..___ 267

Sulphides __________________________________ 271

Fluorides _______________________..__________ 273

Corundum ____________________________ 274

The spinels ----^- - - - -.. - 279

Hematite ___________________________________.._ 284

Titanium minerals___________________________ 286

Cassiterite and zircon____________________ _______ 290

Phosphates __________________________________ 292

Quartz, tridymite,. and opal____________________ _ 294

. The feldspars ________________._.___________ 300

Leucite and analcite______i___________________ 304

The uephelite .group______________________________ 307

The cancrinite-sotlalite group_________:______ 309.

The pyroxenes__________________________________ 311

The amphiboles _____-_______________________ 318

The olivine group_________________________ 323

The micas _________________________________ >.- 326

The chlorites _________________________________ 331

The nielilite group______________________________ 332

The garnets __________________________________ 334

Vesuvianite __ _________ . __ - 337

The scapolites ___________,__________________ 337

lolite __________________________________-____ 339

The zoisite group _ ______________________ 340

Topaz __________________________________.._ 342

The andalnsite group__*______________________..__________- 343

Staurolite _________________________________ 344

Lawsonite __ __ __ _ _______ 345

Duuiortierite ___ _ __ ________ __ _ 345

Tourmaline _^____ ______ :- _ _ 346

Beryl ________________________________________ 347

Serpentine and talc______________-____________ ____ 348

The zeolites ____ ____ 349

The carbonates ______________ _ ______________ 351

CHAPTER XI. Igneous rocks_.._____, _ _____________ 352

Preliminary considerations ______ _________________ 352

Classification ______..___________ ______________ 353

Composition of rocks ____________________1________ 365

The rhyolite-granite group___ ___ _ _____ 366

The trachyte-syenite group__ _____ ___ 370
6 CONTENTS.

CHAPTER XI. Igneous rocks Continued. Page. 

Composition of rocks Continued.

Nephelite rocks_____________________________ 373

Leucite rocks. ________________..___________ 376

 Analcite rocks________________.____________ 378

The monzonite group____________i____________ 380

The andesite-diorite series ___________________'___ 381

The basalts_______________________________ 385

Diabase _________________________________ 387

The gabbros________________________________ 388

Femic rocks ___^_____ __: __._________________ 390

Basic rocks__________..____________________ 393

Limiting conditions________________ _____________ 394

Proximate calculations _l______ ________________ 397

CHAPTER XII. The decomposition of rocks_________..__________ 401

The general process ___________'______________:__ 401

Solubility of minerals __________________________ 403

Effects of vegetation _ _________..________.._____'__ 408

Influence of bacteria _____________________________ 409

Influence of animal life ________________ __- __________ 410

Products of decomposition _________________________ 411

Rate of decomposition_______________________:____ 415

Kaolin _____-_______ _ __________ _ ____ 416

Laterite and bauxite________-_.-________ _-_____ 417

Absorption ___ _ __..____. _ ________ 424

Sand _______________________________________ 426

Silt ______________-______________..___________ 428

Glacial clays_______________________-___________ 430

Loess ________________________________1______ 432

Marine sediments_____________________ ______ 435

Glauconite ___________________________________ 439

Phosphate rock _____ _ _ _____ ______ 442

Ferric hydroxides ____________________________ _ 451

Manganese-.'ores____________________ __ 455

CHAPTER XIII. Sedimentary and detrital rocks. _ 459

Sandstones _________________ __________ . 459

Flint and chertl________________________________ 464

Shale and slate_-_____________________ __________ 467

Limestone ____ ____ ____ __ _ *_____ _ _ _ 470

Dolomite ______________________________-.__ 480

Iron carbonate._____ _________________ _ __ 490

Silicated iron ores_____________________________ 492

Gypsum __ - _ _ ___________! _ ____ 494

Native sulphur _______________________________ 495

Celestite ________________________________ 497

Barite __ __________________________.._-__ 498

Fluorite ______________________________________ 500

CHAPTER XIV. Metamorphic rocks______________________ 501

Metamorphic processes_____________________________ 501

Classification ____ ___________________________ 505

Uralitization __________^___________i____________ 507

Glaucophane schists __ ______ 508
CONTENTS. 7

CHAPTER XIV. Metamorphic rocks Continued. .. Page.

Sericitizatiou __________________________________ 510

Other alterations of feldspar________________i__________ 512

Chloritization __________________________________ 517

Constitutional forimike_____--___________________ 518

Talc and serpentine____________________________ 519

Quartzite _________________..________..________: __ 523

Metamorphosed shales____________________________ 524

Ferruginous schists ____________..________________ 526

Dehydration of clays__-_____________________________ 526

Mica schist __________________________________ 531

Gneiss.____________________________________ 534

Metaiuorphic limestones__________________________ 536

CHAPTER XV. Metallic ores___________________- _____________ 541

Definition ___________________________________ 54.1.

Source of metals_______________________________ 542

Gold ___________________________________________ 553

Silver____________________________1____________ 558

Copper _ ________________ _____ 564

Mercury _______________________________________ 572

Zinc and cadmium______________.________________ 577

Lead _____________________________________ 584

Tin___________________________________1____ __ 591

Arsenic, antimony, and bismuth_____________.________ 595

Nickel and cobalt_______________________________ 598

Chromium _________________________..__________ 603

Molybdenum and tungsten_______________________ 605

The platinum metals____________________________ 607

Vanadium and uranium_________________________ 611

Columbium, tantalum, and the rare earths._______________ 616

CHAPTER XVI. The natural hydrocarbons________________ 619

Composition _________________________________ __ 619

Syntheses of petroleum__________________________ . 627

Origin of petroleum__;____________ 631

CHAPTER XVII. Coal_____________________________ 642

Origin of coal______.____________________________ 642

Peat___________________.________-__________ 645

Lignite _________________________________-___ 648

Bituminous coali________________________ _ ______ 653

Anthracite .__________________________________ 655

The variations of coal_____________________________ 658

The gases in coal_____________________ _______ 660

Artificial coals__________________________________ 663

The constitution of coal___ _________________________ 666

INDEX_______________ _ _______ ______ 669

THE DATA OF GEOCHEMISTRY.

By F. W. CLA^KE.

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 more than 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 qiiartzite or limestone, consist of one mineral only, more 

or less impure; but most rocks are mixtures of species, in \vhich, 

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. Sim9
10 THSJ DATA OF GEOCHEMISTRY.

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

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 sj^stem, 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 geological chemist. 

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 studj^; and the reactions which take place in it may be conveniently classified under three 

heads first, reactions between the essential constituents of the crust 

itself; second, reactions due to its aqueous envelope; and third, reactions produced by the agency of the atmosphere. That the three 

classes of reactions shade into one another, that they are not'sharply 

defined, must be admitted; but the distinction between them is valid 

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

the data. Under the first heading the reactions which occur in volcanic magmas and during their contact with rock masses are studied; 

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

the chemistry of natural waters in general; the essentially surficial 

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

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

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

definite enough to consider separately. First and innermost there 

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

which forms the nearest approach to the original material of which 

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

sedimentary and fragmental rocks; and above this is the third layer
INTRODUCTION. 11

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

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

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

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

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

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

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

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

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

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

too uncertain.

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

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

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

are not recent and great masses of modern data are as yet uncor- 

' related. 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. 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.
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 us now to speculate upon the ultimate nature of these 

bodies; it is enough for the geologist 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 they are the final results of analysis, beyond which 

we need not go. It is probable that the elements were originally 

developed by a process of evolution from one primal stuff, as shown 

by the progressive chemical complexity observed in passing from the 

simpler nebula? through the hotter stars to the cold planets,* but such 

conceptions have no immediate bearing on geochemical problems. 

The transformation of radium into helium indicates an instability 

of the elements, but this appears to be so slight that its discussion 

here would be inappropriate and premature. 6 For present purposes 

the elements -are our fundamental chemical units, and the questions 

of their origin and transmutability may be left out of consideration.

At present the elements enumerated in the subjoined table are 

known, all doubtful substances being omitted. The radioactive elements, polonium, actinium, radiothorium, etc., are also disregarded 

for the reasons that they are imperfectly known and geologically 

unimportant.

a See F. W. Clarke, Pop. Sci. Monthly, January, 1873. Also the later, well-known 

speculations of J. Norman Lockyer.

0 There is evidence to show that the metals uranium and thorium also break down into 

lower forms of matter, but the change is very slight and very slow. The bearing of the 

phenomena upon geochemistry is not yet clear.

12
THE CHEMICAL -ELEMENTS.' 13

Elements, symbols, and atomic weights.

Element.

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

IVIan firan ese

Symbol.

Al 

Sb 

A 

As 

Ba 

Bi 

B 

Br 

Cd 

Cs 

Ca 

C 

Ce 

Cl 

Cr 

Co 

Cb 

Cu

1?

En 

F 

Gel 

Ga 

Ge 

Gl 

Au 

He 

Ho 

H 

In 

I 

Ir 

Fe 

Kr 

La 

Pb 

Li 

Mg 

Mn 

Hg

Atomic 

weight.

27.1 

120.2 

39.9 

75.0 

137.4 

208.0 

11.0 

79.96 

112.4 

132.9 

40.1 

12.00 

140. 25 

35.45. 

52.1 

59.0 

94 

63.6 

162.5 

166 

152 

19.0 

156 

70:0 

72.5 

9.1 

197.2 

4.0

CO 

1.008 

115 

126. 97 

193. 0 

55.9 

81.8 

138.9 

206. 9 

7.03 

24.36 

55.0 

200.0

Element.

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

Palladium ...................

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

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

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

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

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

Yttrium......................

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 

U 

V 

Xe 

Yb 

Y 

Zn 

Zr

Atomic 

weight.

96.0 

143.6 

20 

58.7 

14.01 

191. 0 

16.00 

106.5 

31.0 

194.8 

39.15 

140.5 

225 

103.0 

85.6 

101.7 

150.3 

 44.1 

79.2 

28.4 

107.-93 

23.05 

87.6 

32.06 

181 

127.6 

159.2 

204.1 

232.5 

171 

119.0 

48.1 

184.0 

238.5 

51.2 

128 

173.0 

89.0 

65.4 

90.6

DISTRIBUTION OF THIS ELEMENTS."

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 f olloAvs:

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

constituent of all important rocks except the sandstones and limestones, and even in these its compounds are common impurities. Being easily oxidized, it nowhere occurs native. Found chiefly in 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 sulphantimonicles of the heavy metals, and as 

oxide of secondary origin. The minerals of antimony are generally

0 For an early table showing distribution, see filie de Beaumont, Bull. Soc. g6ol., 2d ser., 

vol. 4, p. 1333, 1846-47.
J4 THE DATA OF GEOCHEMISTBY.

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 sometimes found in mineral springs. No compounds of argon are known.

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

sulpharsenides of the heavy metals, as oxide, and in 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 min- 

 eral, especially thermal, springs. In its chemical relations it is 

regarded as nonmetallic and closely allied to phosphorus.

Barium. Widely distributed in small quantities throughout the 

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

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

witherite. This element occurs only in oxidized compounds.

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

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

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

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

Boron. An essential constituent of several silicates, notably of 

tourmaline and datolite. Its compounds are obtained commercially 

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

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

volcanic springs. Some alkaline lakes 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.

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

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

The very rare mineral pollucite is a silicate of aluminum and 

caesium.

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

nature uncombined. An essential constituent of many rock-forming 

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

the pyroxenes, and scapolite. Limestone is the carbonate, fluor spar 

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
THE CHEMICAL ELEMENTS. 15

natural waters and in connection Avith 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 allanite, 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 forni 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 Avhich it is generally 

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

salts derived from those compounds.

Columbium. 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 pegmatite veins.

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

rocks, although they are rarely determined quantitatively. Also 

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

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

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

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

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

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

" Yttrium."
16 THE DATA OF GEOCHEMISTBY.

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 iif a goodly number of silicates, such as topaz, 

tourmaline, the micas, etc. Fluorine, therefore, .is commonly present 

in igneous rocks, although in small quantities.

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

and " Yttrium."

Gallium. A very rare metal whose salts resemble those of 

aluminum. Found in traces in many zinc blendes. Always present 

in spectroscopic traces in bauxite and in nearly all aluminous 

minerals.

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

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

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

aluminate, chrysoberyl; in several rare silicates and phosphates; 

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

occur in granitic rocks.

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

widely distributed and under a great variety of conditions, but 

almost invariably associated with quartz or.pyrite. Gold has been 

observed in process of deposition, probably from solution in alkaline 

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

very small traces, in sea water.

Helium. An inert gas obtained from uraninite. The largest 

quantities are derived from the highly crystalline uraninite found 

in pegmatite. The massive mineral from metalliferous veins Contains little or no helium. Traces o'f 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 

rocks, it is found, either as occluded moisture, as water of crystallization, or combined as hydroxyl. AIL 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.
THE CHEMICAL ELEMENTS. 17

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."

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

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

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

micas, or divine. 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' iiiert 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.'

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 

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. 

1 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. 

14399 Bull. 330 08 2
18 "" THE DATA OF GEOCHEMISTEY.

Molybdenum. One of the rarer metals. Most frequently found-ingranite 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, in 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 ingredient of living matter, especially 

of bones, and certain large deposits of calcium phosphate are of 

organic origin.

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

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

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

and generally uncombined. To the latter statement there are two 

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
THE CHEMICAL ELEMENTS. 19

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

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

identified in the sulphide ores of the Eambler 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 at 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,ft 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.

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 

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

AV ater.

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 aegirite. Also abundant 

in rock salt, and in nearly all natural Avaters, sea Avater especially.

Strontium. A metal intermediate between calcium and barium, but 

less abundant than the latter. Strontium in small amount is a com0 Proc. Roy. Soc., vol. 77, ser. A, p. 472, 1906.
20 THE DATA OF GEOCHEMISTRY.

mon 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, haiiynite 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 arid 

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.0 Its commonest occurrences are as titanite, ilmenite, rutile, and perofskite. The element is 

often concentrated in beds of, titanic iron ore.

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

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

minerals wolfram, hubnerite, scheelite, and stolzite.

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

0 F. P. Dunnington (Am. Tour. Sci., 3d ser., vol. 42, p. 491, 1891) has shown the abundance of titanium in soils and clays. He gives ahout eighty determinations.
THE CHEMICAL ELEMENTS. 21

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.

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 

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, f ranklinite; 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.

RELATIVE ABUNDANCE OF THE ELEMENTS.

In any attempt to compute the relative abundance of the chemical 

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

Our knowledge of terrestrial matter extends but a short distance 

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

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

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

layers our . information is reasonably good, and their masses are 

approximately determined; but for the last one we must assume 

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

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

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

volcanic outflows Avhich 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. K,. 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 con-
22 THE DATA OF GEOCHEMISTRY.

tinents above the sea, is 1,633,000,000 cubic miles, and to. this 

material we may assign a mean density not lower than 2.5 nor much 

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

cubic miles, 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, Ave get the following expression 

for the composition of the known matter of our globe:

Composition of known matter of the earth.

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

2.5

0.03

92.89

100.00

2.7

0.03

6.58

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. 6 The figure thus assigned to the 

ocean is probably a little too high, but its adoption makes an allowance for the fresh waters of the globe, which are too small in amount 

to be' estimable directly. Their insignificance may be inferred from 

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

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

mass of matter under consideration. A quantity of water equiva-. 

lent to 1 per cent of the ocean, or 0.07 per cent of the matter now 

under consideration, 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. 6'

The composition of the ocean is easily determined from the data 

given by Dittmar in the report of the Challenger expedition.^ 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

0 Sir John Murray (Scottish Geog. Mag., 1888, p. 39) estimates the "volume of the ocean 

at 323,722,150 cubic miles. K. Karste'ns, more recently (Eine neue Berechnung der mittleren Tiefen der Oceane, Inaug. Diss., Kiel, 1894), put it at 1,285,935,211 cubic kilo-' 

meters, 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. .- . 

- 6 .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.

c The amount of the so-called "ground water," which is contained in the porous rooks, 

is difficult to estimate. C. R. Van Hise (Treatise on meta.morphism : Mon. T.T. S. Geol. 

Survey, vol. 47, p. 129, 1904) calculates that the water in the rocks to a depth of 10,000 

meters is equal to a sheet covering all the continental areas .69 meters, or 226 feet* deep. 

See also a questionable computation by W. B. Greenlee, in Am. Geologist, vol. 18, p. 33, 

1896.' . '

d In vol. 1, Physics and chemistry.
THE CHEMICAL ELEMENTS. 23

average value we can allow for saline masses inclosed within the 

solid crust of the earth, and 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 

NaCl - -

MgCl,

MgS04 _ - --

CaSO4 _ _

K_S04 _ 

MgBr, ______

CaCO3 _ . __ .

of oceanic salts. 

____ _ _ . 77.70

_ _ - __ _ 10.88

. - 4.74

______ _ _ 3.60

___________ _. 2.40

.22

_ . _____ .34

100. 00

0 _

H

PI

Na _

Mg__

Ca __

K _

S _

Br _

C __

Composition of ocean. 

__ _ __ __ __ _____ __ 85.79

______ ___________ __ 10.07

.__. _ ---- _ _. 2.07

-_-_.- _ _ _ 1.14

_ __ _____ . _-_ _ __ .14

_ ______ _ .05

_ ________-___- _______ .04

_______ - - .09

_ _ __ _______ _ _ .008

1_ _____ ___ .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.0 In the 

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

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

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

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

a total volume of 325,000 cubic miles. That is, the data used for computing the average composition of the ocean and its average significance as a part of all terrestrial matter are maxima, and therefore 

tend to compensate for the omission of factors which could not well 

be estimated directly. ! ' ;

The average composition of the lithosphere is very nearly that of 

the igneous rocks alone. The sedimentary rocks represent altered 

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

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

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

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

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

"According to T. Toly (Sci. Trans.. Roy. Soc. Dublin, 2d ser., vol. 7, p. 30, 1890), the 

sodium chloride In the ocean would cover the entire globe 11- feet deep.
THE DATA OF GEOCHEMISTRY.

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, Avhen 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, liine, 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, 1904, in the laboratories of the Survey.&

E. An average, computed by A. Harker, c of 397 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.* 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, 

although they are not absolutely comparable. The comparison assumes the following form:

Average composition of igneous rocks.

SiO2 . ......... ............................

A12 03 ....................................

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

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

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

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

NaoO......... ".......-....................

KoO.......... ............................

HoO at 100°. ..............................

fiOz.................. ....................

T> C\

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. SB 

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.

60.91 

15.28 

2.63 

3.46 

4.13 

4.88 

3.45 

2.98 

.41 

1.49 

.73 

.26

100. 61

Harker.

E.

58.75 

15.64 

5.34 

2.40 

4.09 

4.98 

3.25 

" 2. 74

1 2.23

.12 

.02

99.56

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

"Bull. Phil. Soc. Washington, vol. 11, p. 131, 1889. Also in Bull. U. S. Geol. Survey 

No. 78, p. 34, 1891. ' 

6 See Bull. U. S. Geol. Survey No. 228, p. 17, 1904, for details.

< Geol. Mag., 1899, p. 220.

rf Prof. Paper U. S. Geol. Survey No. 14, p. 106, 1903. In this average and in .Barker's 

there are data for manganese, which I now leave temporarily out of account.
THE CHEMICAL ELEMENTS. 25

Although these six columns are not very divergent, there are 

differences between them which may be more apparent than real. 

Differences of summation are partly due 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:

Recalculated average composition of igneous rocks.

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

AljOs... ..................................

Fe2 03 ....................................

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

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

NaoO ....................................

KoO..... .................................

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

L> f\

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

0.

61.12

15.77

2.69

3.60

4.46

5.02

3.63

2.87

.61

.23

100. 00

D.

61.71

15.48

2.68

3.50

4.18

4.94

3.49

3.02

.74

.26

100.00

E.

60.36

16.07

5.48

2.46

4.20

5.12

3.34

2.83

.12

.02

100. 00

F.

58.96

Ti QQ

3 Q7

3.93

3 on

5.28

3.96

3.20

1.06

VI

100. 00

Of these 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 imperfect analyses. D and F, however, 

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 Avork 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 a criticism by E. P. Mennell,tt 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 he believes that the true 

average should approximate the composition of a granite. A wider

0 Geol. Mag., 5th ser., vol. 1, p. 263, 1904. For other discussions of the data given in 

my former papers, see L. De Launay, Revue g6n. sci., April 30, 1904 ; and C. Ochsenius, 

Zeitschr. prakt. Geol., May, 1898. Compare also R. A. Daly, Bull. U. S. Geol. Survey No. 

209, p. 110, 1903, who argues that the universal or fundamental magma is approximately 

basaltic.
26 THE DATA OF GEOCHEMISTRY.

range of observation would probably modify that opinion, which, 

however, is entitled to some weight.

So far, my 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 appsar, 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.

Complete avereage of analyses of igneous rooks made in the laboratories of the 

United States Geological Surrey.

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

AloO.v. ...................................

Fe203 ... ...........................:......

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

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

CaO ..........'............................

NaoO .:.........................:.:.......

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

H,0-. ...................................

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

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

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

co2 .........:............................ 'P A

s?°:::::::::::::::::::::::::::::::::::::::

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

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

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

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

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

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

Cr,03 .-.. .................................

V203 . ....................................

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

Number 

of 

determinations.

1,358

912

 961

962

1,027

1,215

1,268

1,265

770

832

870

185

469

884

575

234

73

617

520

899

243

40

550

Average.

60.91

15. 28

2. 63

3.46

4.13

4.88

3.45

2.98

- .41

L49

 .73

.03

.53 . 26

.11

.07

.02

.11

.04

.10

.03

05

.03

.01

101. 74

Reduced 

to 100 

percent.

59. 87

15. 02

2.58

3.40

4.06

4.79

3.39

2.93

.40

1.46

.72

.03

.52

.26

 . 11

.07

.02

.11

.04

.10

.03

.05

fM

.01

100. 00

In elementary

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

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

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

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

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

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

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

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

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

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

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

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

S .................

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

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

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

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

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

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

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

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

form.

47.09

28.23

7.99

4.46

2.46

3.43

2.53

2.44

.17

.43

.020

.14

.11

.11

.07

.02

.089

.034

.084

.023

. 034'

.02

.01

-I Af\ fiflA

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

only very rough approximations. 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" 

and J. F/ Kemp 6 can be consulted. It is probable that no one of

"Zeitschr. prakt. Geol., 1898, pp. 225, 314, 377, 413 ; 1899, pp. 10, 274.

6 Science, January 5, 1906; Econ. Geol., vol. 1, p. 207, 1905. See also a curious paper 

by W. Ackroyd, in Chem. News, vol. 86, p. 187, 1902. \V. N. Hartley and H. Rainage (Jour. 

Cliem. Soc., vol. 71, p. 533, 1897), have shown that some of the rarest elements, such as 

gallium and indium, are widely diffused in rocks and minerals.
THE CHEMICAL ELEMENTS.

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 

mixtures of man}7 rocks were prepared," 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. v 

B. Composite analysis of 253 sandstones. 

0. Composite analysis of 345 limestones.

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

A1 20S .... .................................................................

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

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

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

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

Na»0 ....................................................................

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

HoO at 110°. ..............................................................

H.,0 above 110°. ..........................................................

TiOo.......................................................... ...........

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

P2 05 ..................................... .................................

S .........................................................................

S08 .. ....................................................................

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

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

sro.. ...........:.......................................................

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

Li2 0 ... ..\ ..............................................................

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

.81

100. 46

B.

78.66

4.78

1.08

.30

1.17

5.52

.45

' 1. 32

.31

a 1. 33

.25

5.04

.08

.07

.05

.100. 41

C.

5.19

.81

J

'id

7.90

42. 61

.05

. .33

.21

".56

.06

41.58

.04

' .09

.05

.02

none

.05

100. 09

o 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. The analyses of the latter are too few to give conclusive averages, but the data published in the Challenger reports''

0 These mixtures were prepared by G. W. Stose, under the direction of G. K. Gilbert. 

The analyses were made by H. N. Stokes in the laboratory of the United States Geological 

Survey. See Bull. TJ. S. Geol. Survey No. 228, p. 20, 1904.

b Volume on Deep-sea deposits, p. 198.
28 THE DATA OF GEOCHEMISTKY.

indicate a difference between them and the terrigenous deposits. The 

" red clay," for example, which covers 51,500,000 miles of the ocean 

floor at its greatest depths, is richer in iron than the average shale. 

The thickness of this deposit is unknown. 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, how-" 

ever, help to explain a deficiency of magnesium which appears in the 

sedimentary analyses. Partly on account of these considerations, and 

partly because the sedimentary rocks contain water and carbon dioxide which have been added to the original igneous material, we can not 

recombine the composite analyses so as to reproduce exactly the composition of the primitive matter.* 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 2.56; 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

0 For an elaborate attempt in this direction, see C. R. Van Hise, Treatise on metamorphism: Mon. U. S. Geol. Survey, vol. 47, pp. 947-1002, 1904.
THE CHEMICAL ELEMENTS. 29

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 

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 allow- 

 ajice 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,0 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 unia Text-book of Geology, 4th ed., vol. 1, p. 49, 1903.
30 THE DATA OF GEOCHEMISTRY.

formly over the globe, it would form a shell about 660 feet thick. If 

we assume this matter to be all sedimentary, which, it certainly is not, 

and add to it any probable allowance for the sediments at the bottom 

of the sea, we shall still fall far short of the half-mile shell, which, on 

chemical evidence, is a maximum. In the following calculation this 

maximum will be taken for granted.

The relative proportions of the different sedimentary rocks within 

the half-mile shell can only be estimated approximately. Such an 

estimate is best made by studying the average igneous rock and determining in what way it can break down. A statistical examination of 

about 700 igneous rocks, which have been described petrographically, 

leads to the following rough estimate of their mean mineralogical 

composition:

Quartz ________________________.________ 12. 0

Feldspars____________________________ 59. 5

Hornblende and pyroxeue________ _____'________ 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 component minerals:

Average composition of shale a,nd sandstone.

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

Clayb..... .....................................................................

Shale.

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

"The total percentage of free silica.

6 Probably sericite in part. In that case the feldspar figure becomes lower.

If, now, we assume that all of the igneous quartz, 12 per cent, has 

become sandstone, it will yield 18 per cent of that rock, which is 

evidently a maximum. Some quartz has remained in the shales. 

One hundred parts of the average igneous rock will form, on decomposition, less than 18 parts of sandstone.

The igneous rocks contain, as shown in the last analysis cited, 4.79 

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
THE CHEMICAL ELEMENTS. 81

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, AVC shall come as near 

the truth as is possible with the present data." On this basis, the 

average composition of the lithosphere may be summed up as shoAAm 

in the subjoined table. The analyses of the sedimentary rocks are 

recalculated to 100 per cent.

Average compoaition of the Uthosphere.

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

Al-A,.. ...........................

FeoOa .............................

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

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

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

TJn O

K n

H»0 ..............................

TiOo. .............................

7-A

COo. ......... ..........X - --

PoO* .............................. o s 5

Qn

Pi

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

BuO .............................

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

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

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

Cr20;, .............................

VjA,. ............... ..............

Lf20...................... ........

Igneous 

(95 per cent).

59. 87

15. 02

2.58

3.40

4.06

4.79

3.39

2.93

1.86

.72

.03

.52

.26

.11

.07

.02

.11

.04

.10

.03

.05

:03

.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 :o<i

.09

.05

.02

.06

100.00

Average.

59. 79

, 14. 92

2.63

3 <W

3.98

4.82

3.28

2.96

1.98

.71

.03

.74

.25

.10

.02

.07

.02

.10

.04

.09

.03

.05

.02

.01

.03

100.00

The final average differs from that of the igneous rocks alone only 

Avithin 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 Avater and carbon 

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

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

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

hardly Avorth Avhile to speculate. -The values chosen for the sediments are approximations only, and nothing more can be claimed for

a C. R. Van Hise (Treatise on rnetamorphism : Mon. U. S. Geol. Survey, vol. 47, p. 940, 

1904) divides the sedimentary rocks into Go per cent, shales, including all pelites and 

psepbites, 30 per cent sandstones, and 5 per cent limestones. W. .T. Mead (Jour. Geol., 

vol. 15, p. 238, 1907), by a graphic process, distributes the sedimentaries into 80 per cent 

Shales, 11 per cent sand.stones, and 9 per cent limestpnes.
32 THE DATA OF GEOCHEMISTRY.

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.

Now, with the help of this new "average, we are in a position to 

compute the relative abundance of the chemical elements in all known 

terrestrial matter. For this purpose, the column is restated in elementary form, with an arbitrary allowance of 0.5 per cent for all the elements not specifically included in it. As for the atmosphere, .it is 

represented in the final result by 0.02 per cent of nitrogen, which is a 

little too low. The mean composition of the lithosphere, the ocean, 

and the atmosphere, then, is as follows:

Average composition of lithosphere, ocean, and atmosphere.

'

Lithosphere 

(93 per cent) .

47.07

28.06

7.90

4.43

3.44

2.40

2.43

2.45

.22

.40

.20

.07

.11

.11

.09

.07

.03

.02

.50

100. 00

Ocean (7 per 

cent).

85. 79

OH

.14

1.14

.04

10.67

009

2.07

.008

.09

100.00

Average, 

including 

nitrogen.

49 78

26.08

7.34

4.11

3 19

2.24

2.33

2.28

.95

.37

.19

.21

.11

.11

.09

.07

.03

.02

.02

.48

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,a and above 

that, in the analyses given on page 26, 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 

improvable. 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 densitv greater than that of the earth. Combination

The atomic weight of iron is 55.9 when O=16.
THE CHEMICAL ELEMENTS. 33

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 Ave know nothing.

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:

14399 Bull. 330 08 8
Periodic classification of the eleme

Series.

1 .....

2 .....

3.....

4 .....

5 .....

6

9

10

11

1 9

Group 0.

He-4

Ne=20

A-39. 9 '

Kr-81.8

Xe-128

Group 1.

H 1

Li 7

Na-23

K-39. 1

Cu-63.6

Rb-85.5

Ag 107. 93

Pa 1 39 Q

An 1Q7 9

Group 2.

Gl-9.1

Mg 24. 4

Ca-40. 1

Zn 65.4

o« 0*7 a

Cd=112.4

Ba 137. 4

Hg 200 

Ra-225

Group 3.

B 11

Al 27. 1

Sc 44. 1

Ga 70

Y QQ

In 115

TO i QC q

 >

Tl 904. 1

Group 4.

C 12

Si -28. 4

Ti 48. 1

Ge-72.5

Zr-90. 6

Sn 119

Ce-140. 25

Pb 206. 9

Th 9Q9 z\

N

V 

C

T

U
THE CHEMICAJL ELEMENTS. 35

In each vertical column the elements are closely allied, forming 

the natural groups to Avhich 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 Mendeleef

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 dis-. 

covery, and in every essential particular his predictions Avere correct. 

Atomic weights, densities, melting points, and the character of the 

compounds which the metals should form Avere foretold, and in each 

case Avith a remarkable approximation to accuracy. This po\ver of 

prevision is characteristic of all valid generalizations, and its exhibition in the periodic system led to the speedy adoption of the latter. 

EAren radium, the youngest member of the elementary series, falls 

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

An elaborate discussion of the periodic laAv would be out of place 

in a memoir of* this kind, and its details must be sought elseAvhere." 

Only its "application to geochemistry can be considered HOAV. 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 o.f zinc, and 

so on through a long list of regularities. The group relations govern 

many of the associations Avhich AVC actually observe, although they 

are modified by the conditions Avhich influence chemical union. EAren 

here, hoAvever, regularities are still apparent. In combination unlike 

elements seek one another, and yet there appears to be a preference

" See especially F. P. Venable, Development of the Periodic Law, Easton, Pennsylvania, 

189G. The larger manuals of chemistry all discuss the law somewhat fully. T. Carnelley 

(Ber. Deutsch. chem. Gesell., vol. 17, p. 2287, 1884) has especially studied the bearings of 

the periodic law on the occurrence of the elements in nature.
36 THE DATA OF GEOCHEMISTRY.

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

example, silicon follows aluminum in the order of atomic weights, 

and silicates of aluminum are by far the most abundant minerals. 

The next element in order is phosphorus, and aluminum phosphates 

are more common and more numerous than the precisely similar arsenates. On the other hand, copper, whose.atomic weight is nearer 

that of arsenic, oftener forms arsenates, although its phosphates are 

also known. An even more striking example is furnished by the 

compounds of the elementary series oxygen, sulphur, selenium, and 

tellurium. Oxides and oxidized salts of many elements are found in 

the mineral kingdom, and most commonly of metals having low 

atomic weights. From manganese and iron upward, sulphides are 

abundant; but selenium and tellurium are more often united with 

the heavier metals silver, mercury, lead, or bismuth, and tellurium 

Avith 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 abundanceincreases 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 AVC 

are dealing with an evident tendency of which the meaning is yet 

to be disco A^ered. That the abundance and associations of the elements are connected Avith their position in the periodic SArstem seems, 

however, to be clear. The coincidences are many, the exceptions are 

comparatively feAv.

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 laAv coA^ers only a part of the elementary associations. Bocks are formed from magmas in which many and com-
THE CHEMICAL ELEMENTS. 37

plex reactions are possible and the simpler rules governing single 

minerals are no longer directly applicable. Some regularities, however, can be recognized, and certain elements are in a sense characteristic of certain kinds of rock. In the summary already given some of 

these regularities are indicated. They have been generalized by 

J. H. L. Vogt a somewhat as follows: In the highly siliceous rocks 

we find the largest proportions of the alkalies, .of the rare earths, and 

of the elements grucmum, 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; Avhereas chromium, nickel, and the platinum metals are 

most commonly associated with peridotites or serpentines. For these 

differences in distribution no complete explanation is at hand; but 

they are probably due to differences of solubility. If we conceive of 

a mediosilicic magma in process of differentiation into a salic and a 

femic portion, the minor constituents will evidently tend to concentrate, each in the magmatic fraction in which it is most soluble. 

Solubilities of this order are yet to be experimentally studied.

« Zeitschr. prakt. Geol., 1898, p. 324.
CHAPTER II. 

THE ATMOSPHERE.

COMPOSITION OF THE ATMOSPHERE.

The outer, gaseous envelope of our globe the atmosphere is commonly regarded as rather simple in its constitution, and indeed so it 

is, in comparison with the complexity of the ocean and the solid rocks 

beneath. Broadly considered, it consists of three chief constituents 

namely, oxygen, nitrogen, and argon commingled with various 

other substances in relatively small amounts, which may be classed, 

with some exceptions, as impurities. The three essential elements of 

air are mixed, but not combined; and they vary but little in their 

proportions. They constitute what may be called normal or average 

air. I am indebted to Sir William Ramsay for the following percentage estimate of their relative quantities.

The principal constituents of the atm,osphere.

C\\VQrpT\

By weight.

23. 024

1.437

100. 000

By volume.

20. 941

78. 122

.937

100. 000

With the argon occur certain rare gase's whose proportions Ramsay 

estimates as follows:

Helium, 1 to 2 parts per million. ** 

Neon, 1 to 2 parts per hundred thousand. 

Krypton, 1 part in 20 millions. 

Xenon, 1 part in 170 millions.

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

have little geological significance they demand no further considera- i 

tion here.

In addition to tho elements enumerated above, ordinary air contains, 

in varying quantities, aqueous vapor, hydrogen dioxide, carbon 

dioxide, ammonia ,ad other compounds of nitrogen, sometimes sulphur, traces of hydrogen, organic matter, and suspended solids; and 

38
THE ATMOSPHERE. 39

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 \vhich 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 hot absolutely so; for the innumerable analyses of air reveal variations larger 

than can be ascribed to experimental errors. A few of the better 

determinations are given in the subjoined table, stated in percentages 

by volume of oxygen. They refer, of course, to air dried, and freed 

.from all extraneous substances.

Determinations of oxygen in air, in percentage by volume.

Analyst.

R. \V. Bunsen«..............

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

W. Hempel o ................

W.Hempeld.. ....... .......

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

A. Muntz and E. Aubin «.... 

E.W.Morley/. .............

Locality of samples.

Pnrio

Tromsoe

Cape Horn ................ 

Cleveland, Ohio. ..........

Number 

of 

analyses.

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

01 nn

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

0 See R. Angus Smith's excellent book, Air and Rain, London, 1872. This work contains 

hundreds of other analyses.

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

c Ber. Deutsch. chem. Gesell., vol. 18, p. 1800, 1885.

d Ber. Deutsch. chem. Gesell., vol. 20, p. 1864, 1887.

"Compt. Rend., vol. 102, p. 422, 1SS6.

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

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 thajt 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." As oxygen is heavier than nitrogen, it has been supposed 

that the upper regions of the atmosphere should show a small deficiency in oxygen, as compared with air from lower levels; although 

analyses of samples collected on mountain tops and from balloons 

have not borne out this suspicion. It is also supposed that severe 

depressions of temperature, the so-called " coldjlwaves," are connected with descents of air from very great elevations. Morley's 

analyses, conducted daily from January, 1880, t> April, 1881, at

"Am. .Tour. Sci., .Sd ser., vol. 18, p. .168, 1879 ; vol. 22, p. 417, 1881.
40 THE DATA OF GEOCHEMISTRY.

Hudson, Ohio, sustain this belief. Every cold wave was attended b}^ 

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. 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.

Wherever animals breathe or fire burns oxygen is being withdrawn 

from the air and locked up in compounds. By growing plants, under 

the influence of sunlight, one of these compounds, carbon dioxide, is 

decomposed and oxygen is liberated; but the losses exceed the gains. 

So also, when the weathering of a rock involves the change of ferrous into-ferric compounds oxygen is absorbed, and only a portion of 

it is ever again released. The atmosphere, then, is slowly being depleted of its oxygen, but so slowly that no chemical test is ever 

likely to detect the change.

The nitrogen of the atmosphere varies reciprocally with the oxygen, the one gaining relatively as the other loses. But here again 

special variations need to be considered. By electrical discharges, 

as we have already seen, oxides of nitrogen are produced, yielding 

with the moisture of the air nitric and nitrous acids. Through the 

agency of microbes certain plants withdraw nitrogen directly from 

the air and thus remove it temporarily from atmospheric circulation. 

By the decay or combustion of organic matter some of this nitrogen 

is returned, partly in the free state and partly in gaseous combinations. The significance of these changes will be more clearly seen 

when we consider the subject of rain. It is enough to note here that 

all the nitrogen of organic matter came originally from the atmosphere, and that at the same time a larger quantity of oxygen was 

oilso 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

0 Ann. chim. phys., 7th ser., vol. 22, p. 5, 1901.
THE ATMOSPHERE. 41

at the Koches-Douvres light-house, off the coast of Brittany, yielded 

1.21 milligrams of hydrogen in 1.00 liters. Air from the streets of 

Paris was found to contain the folloAving substances, in cubic centimeters per 100 liters:

Free hydrogen _______________________ 19. 4

Methane__1_________________.______________ 12.1

Benzene and its homologues________________ 1. 7

Carbonic oxide, with traces of defines and acetylenes..-___ .2

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

in 5,000 .of free hydrogen, although Ray Leigh's n 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 thedecomposition of organic matter, methane or marsh gas in particular 

being clearly recognized among the exhalations from swamps. 

According to H. Hen\riet/' formaldehyde exists in the atmosphere in 

quantities ranging from 2 to 6 grams in 100 cubic meters. Bodies 

of this class are impurities in the atmosphere, and should not be 

reckoned, among its normal 'Constituents.

Sulphur compounds, which are also contaminations of the atmosphere, occur in air in variable quantities. Hydrogen sulphide is 

a product of putrefaction, but it is also given off by volcanoes, 

together with sulphur dioxide. The latter substance is also produced by the combustion of coal, and is-therefore abundant in the 

air of manufacturing districts. At Lille, for example, A. Ladureau " 

found 1.8 cubic centimeters of SO2 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 b}7 

rain. In experiments running over five years at Rothamsted, 

England, R. Warington f1 found that the equivalent of 17.26 pounds 

of SO:! 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

"Phil. Mag., 6th ser., vol. 3, p. 416, 1902. See'also a criticism by A. Lecluc, Compt. 

Rend., vol. 135, p. 860, 1902 ; and replies to Rayleigh and Leduc by Gautier. idem, vol. 135, 

p. 1025 ; vol. 136, p. 21. Also a paper by G. D. Liveing and J. Dewar, Proc. Roy. Soc., vol. 

67, p. 468, 1900.

6 Compt. Kend., vol. 138, pp. 203, 1272, 1904.

" Ann. cliim. phys., 5th ser., vol. 29, p. 427, 1883.

" Jour. C'liem. Soc., vol. 51, p. 500, 1887.
42 THE DATA OF GEOCHEMISTRY.

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,0 abnormal 

extremes being avoided.

Determinations of carbon dioxide in air.

Analyst.

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

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

Locality.

Number of 

determinations.

92

18

525

 46

C03 (volumes per 

10,000 of 

air).

3.027

2. 942

2.816

2.94

2.91

8, p. 1C ,

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

« Cited by Letts and Blake. 

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

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. 6 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 approximate constancy maintained?

From several sources carbon dioxide is being added to the air. 

The combustion of fuels, the respiration o'f 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,c Cotopaxi alone emits more carbon dioxide annually

than is generated by life and combustion in a city like Paris, which 

in 1844 threw into the air daily almost 3,000,000 cubic meters of the 

gas. Since that time the population of Paris has more than doubled, 

and the estimate must be correspondingly increased. The annual 

consumption of coal, estimated by A. Krogh* at 700,000,000 tons 

in 1902, adds yearly to the atmosphere about one-thousandth of its

a 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 B. A. Letts and R. F. Blake, 

in Sci. Proc. Roy. Dublin Soc., vol. 9, pt. 2, pp. 107-270, 1900. The latter memoir 

contains a summary of all the determinations previously made, with a very thorough 

bibliography "of the subject.

6 For example, E. L. Moss (Proc. Roy. Dublin Soc., 2d ser., vol. 2, p. 34, 1878) 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, p. 409, 1904) 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, p. 526, 1906) in ocean air was 3.35 in 10,000.

" E. A. Letts and R. F. Blake, Sci. Proc. Roy. Dublin Soc., vol. 9, pt. 2, pp. 159, 175, 

1900. J. B. Boussingault, Ann. chim. phys., 3d ser., vol. 10, p. 456, 1844.

d Meddelelser om Greenland, vol. 26, p. 419, 1904:
THE ATMOSPHERE. 43

/

present content in carbon dioxide." In a thousand years, then, if the 

rate were constant and no disturbing factors interfered, the amount 

of CO, in the atmosphere would be doubled. Figures like these give 

some faint notion of the magnitude of the chemical processes now 

under consideration. There are other smaller sources of supply, 

also, such as the solution of carbonate rocks, but we need not dwell 

on them at present.

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,6 for instance, from very 

uncertain data, computes that leaf action alone more than compensates for the production of- carbon dioxide; and that without such 

compensation the quantity present in the air would double in about 

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 tit 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.

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 blanketn C. R. Van I-Iise (Treatise on metamorphism : Mon. TJ. S. Geol. Survey, vol. 47, p. 964, 

1904) estimates the total C02 in the atmosphere at 2,.".SI,400,000,000 metric tons. 

''Phil. Mag., 5th ser., vol. 14, p. 387, 1882. 

c Am. Jour. Sci., Hd ser., vol. 19, p. 349, 1880.
44 THE DATA OF GEOCHEMISTKY.

ing the earth, they help to avert excessive changes of temperature. 

On the physical side, and as regards carbon dioxide, this question has 

been ably discussed by S. Arrhenius,0 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 A^ariations of this kind we may find an explanation of the 

alterations of climate which have undoubtedly occurred. The glacial 

period, for example, may have been due to a loss of carbon dioxide 

from the atmosphere. To account for such gains and losses, Arrhenius cites with great fullness the work of Hogbom, who regards volcanoes as the chief source of supply. Just as individual volcanoes 

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

of the globe has varied from time to time. During periods of great 

energy the carbon dioxide of the air would be abundant; at other 

times its quantity would be smaller. Hogbom estimates that the total 

carbon of the atmosphere would form a layer 1 millimeter thick, 

enveloping the entire globe. The quantity of carbon in living matter he regards as being of the same order, neither many fold greater 

nor many fold less. The combustion of coal he reckons as about balancing the losses of the atmosphere by weathering; and in this way 

he reaches his conclusion that volcanic action is the important factor 

of the problem. Hogbom also computes that a shell of limestone 100 

meters thick would be equivalent to about 25,000 times the present 

atmospheric content of carbon dioxide. In calculations of this sort 

there is a certain fascination, but their chief merit seems to lie in their 

suggestiveness. How far the figures given by Hogbom are consistent 

with those of Hunt is a question which I shall leave for others to 

determine.

One other regulative agency remains to be mentioned. The ocean 

is a vast reservoir of carbon dioxide, Avhich 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.

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

"Phil. Mag., 5th ser., vol. 41, p. 237, 1896.
THE ATMOSPHERE. 45

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 

solution weakens the rocks and renders them easier to remove mechanically. As water evaporates from the surface of the sea, it lifts, by 

inclusion in vapory vesicles, great quantities of saline matter, which 

are 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." 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,6 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 temper at'iirea.

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

0« .... ............................ .......... co.,...............................................::

0°.

63. 20

33. 88

2.92

100. 00

5°.

63.35

<« 07

2.08

300.00

10°.

63. '19

34. 05

100. 00

15°.

63.62

14 19

2.26

100. 00

20°.

63. 69

34. 17

2.14

100. 00

In air from sea water O. Petterson and K. Sonden c 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. 

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,

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

* Lleblg's Annalen, vol. 93,'p. 4.8, 1855. See also M. Baumert, idem, vol. 

1853, for evidence of the same order.

c Ber. Deutsch. chern. Gesell., vol. 22, p. 1430, 1889.

P. 37,
46 THE DATA OF GEOCHEMISTRY.

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 agricultural experiment stations, but also for sanitary purposes, and a few of the results obtained are given below.0 A 

figure for sulphuric acid has 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 acre per annum.]

Locality.

DoA........................................

Caracas, Venezuela^. ...........................

Utah'i...........................................

Ammoniacal.

2.406

2. 823

1.009

1 Q^l

2.63

5.06

Nitrogen.

Nitric.

0 917

.516

2.443

o 1 nn

1.06

.356

Total.

3.74

8.93

9.20

3.452

3

R/I1

3.69

5.42

8. 636

Remarks.

In 1888 89.

Do.

Do.

a R. Warington, Jour. Cuem. Soc., vol. 51, p. 500, 1887.

6 R. Warington, Jour. Chem. Soc., vol. 55, p. 537, 1889.

"Albert Levy, Jour. Cheni. Soc., vol. 56, p. 299, 1889. (Abstract.) 10.01 kilos per 

hectare.

d A. Muntz and V. Marcano, Cornpt. Rend., vol. 108, p. 1062, 1889.

" A. Petermann and J. Graftiau, Jour. Chem. Soc., vol. 64, abst. ii, p. 548, 1893. 10.31 

kilos per hectare.

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

0 G. II. Failyer and Breese, Second Ann. Kept. Exper. Sta., Kansas Agric. Coll., 1889.

h Erwin, Fourth Ann. Rept. Utah Agric. Coll. Exper. Sta., 1893.

1 Hutchinson, Tenth Ann. Rept. Mississippi Agric. and Mechan. Coll. Exper. Sta., 1897. 

See also Eighth Ann. Rept.

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 significance of free acids in rain is obvious, for it means an increase in 

the eroding power of water. Furthermore, in this circulation of 

nitrogen between the ground and the air, the ground gains more 

than it loses. All of the nitrogen thus fixed in combination is not 

released again to the atmosphere; only a part so returns.^

0 For the older data see R. Angus .Smith, Air and Rain, London, 1872.

6 T. Schloesing (Contributions a 1'e'tude de la chimie agricole, p. 55, 1888) estimates the 

average ammonia in the atmosphere at 0.02 milligram per cubic meter. This amounts to 

1,600 grams over every hectare of the earth's surface.
THE ATMOSPHERE. 47

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,0 and by 

several later documents of the same kind, in which the "normal 

chlorine " of the potable waters is indicated by isochlors that follow 

the contour of the shore. Near the ocean the waters are rich in 

chlorides, which diminish rapidly as we follow the streams inland.

The amount of salt precipitated by rain upon the land is by no 

means inconsiderable. For quantitative data a few examples must

suffice, stated in the same way as for nitrogen.

Chlorides brought to the surface of the earth by rain. 

[Pounds per acre per annum.]

Locality. Chlorine.

14.40

116. 98

108. 613

Sodium 

chloride.

36.10

24

37.95

Remarks.

In 1^87.

n E. Kinch, Jour. Chem. Soc., vol. 77, p. 1271, 1900. Amount largest in winter, when 

the prevailing wind is off the Bristol Channel.

"ft. Warington, Jour. Chem. Soc.,-vol. 51, p. 500, 1887.

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

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

Warington (loc. cit.) also cites the work at Lincoln, New Zealand, 

by Gray, who gives the following average composition (in parts per 

million) of the impurities in rain water at that point during two 

years:

Cl___________ __________________________________ 7.74

SO8 _____ _____ ____________.___________ 2.01

N in NH3 ______-__-__-_____.__.___________________ .12

N in nitrates.____.._________"_____________ .14

N, albuminoid ____________________________ . 00

Total dissolved matter, 23.6 parts per million.

tt See T. M. Drown, in Kept. Massachusetts State Board of Health, etc., vol. 1, December, 18S9. Mrs. Ellen S. Richards, who was associated with Drown In this investigation, 

has since published, jointly with A. T. Hopkins, a similar map of Jamaica (Tech. Quart, 

vol. 11, p. 227, 1898). For a chlorine map of Long Island, see G. C. Whipple and 

D. D. Jackson, Tech. Quart., vol. 13, p. 145, 1900. 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-Sup, and Irr. Paper No. 144, U. S. Geol. 

Survey, 1905.
48 THE DATA OF GEOCHEMISTRY.

Furthermore, we have the older researches of Pierre,0 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:

NaCl __ _____________ 37.5

KC1 _______________________ 8. 2

MgCls _____________________ 2. 5

CaCl,__-_______________ 1. 8

Na2SO4 ____________________ 8. 4

K2S04 ______________________ 8.0

CaSO* - __- 6. 2

MgSO4 _ _____ _ ___ 5. 9

These citations are enough to show the great geological importance of rainfall, over and above its ordinary mechanical effects, 

and its value as a solvent after it enters the ground. The atmospheric circulation of salt has received much attention, and F. 

Posepny,6 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,0 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 (l has pointed out that without this 

circulation of salt, and its replenishment of the land, the latter 

Avould 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.?

 . 

« See R. Angus Smith, Air and Rain, pp. 232-223, 1872. Pierre also cites valuable data 

obtained by Barral, Bineau, Liebig, Bonssingault, and others. Sec also A. Bobierrc, 

Compt. Rend., vol. 58, p. 755,, 1864, for the composition of rain water collected at Nantes 

in 1863. The average sodium chloride amounted to 14.09 grams per cubic meter.

h Sitzungsb. Akad. Wien, vol. 76, abth. 1, p. 179, 1877. See also a discussion of this 

memoir by E. Tietze, Jahrb. K.-k. geol. Reichsanstalt, vol. 23, p. 341, 1877. In a recent 

discussion of this subject E. Dubols (Arch. Muse'e Teyler, 2 ser., vol. 10, p. 441, 1907) 

has estimated the amount of atmospheric salt annually precipitated in rainfall on two 

provinces of Holland as about 6,000,000 kilograms. ' >

c Geol. Mag., 4th ser., vol. 8, p. 445, 1900. Proc. Yorkshire Geol. and Polytech. Soc., 

vol. 14, p. 408. Chem. News, January 8, 1904.

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

" See J. Aitken, Proc. Roy. Soc. Edinburgh, vol. 17, p. 193, 1890. An interesting lecture 

by A. Ditte (Revue scient., 5th ser., vol. 2, p. 709, 1904), on metals in the atmosphere, is 

well worthy of notice. It deals with dust, meteoric matter; cyclic salts, ammonium compounds, etc.
THE ATMOSPHEEE. 49 

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 nono 

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?

The known carbon of the lithosphere, as shown by the statistics 

in the preceding chapter, if converted into carbon dioxide, would 

yield nearly 25 times the present mass of the entire atmosphere;' and 

its pressure would be almost great enough to liquefy a part of it, 

Any assumption in favor of such an atmospheric accumulation is 

therefore improbable.0

In order to account for the observed phenomena, at least three 

essentially distinct hypotheses have been proposed. The volcanic 

theory has already been considered, and its advocates are numerous; 

but a simpler view perhaps is that of T. Sterry Hunt.6 He argued 

in favor of a cosmical atmosphere, pervading all space, from which 

a steady supply of carbon dioxide has been draAvn. This theory, 

which was also favored b}^ Alexander Winchell," postulates a universal, exhaustless reservoir of carbon, which should be able to satisfy all demands. But what evidence have we that such an atmosphere exists? S. Meunier,'' criticising Hunt, points out that some

n For a curious speculation on the mass of the atmosphere, see R. II. McKee, Science, 

vol. 23, p. 271, 1906. He argues that the present atmosphere Is as great as the earth 

is capable of retaining.

6 Am. Jour. Sci., 3d ser., vol. 10, p. 349, 1880.

0 Science, vol. 2, p. 820, 1883.

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

14399 Bull. 330 08 4
50 THE DATA OF GEOCHEMISTRY.

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, 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?

A third 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 ox}^gen, and he has been 

followed of late years by T. L. Phipson,a J. Lemberg,6 John Stevenson,0 and Lord Kelvin.* Lemberg and Kelvin, however, do not go 

to extremes, but admit that possibly some free oxygen was present 

even in the earliest times. Lemberg argued that the primeval 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 facts 

that no oxygen has been recognized in solar or stellar spectra and that 

none is found in the gases extracted from rocks are 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 atmos0 Chem. News, vol. 67, p. 135, 1893. Also several notes in vols. 68, 69, and 70. For 

Koene's work see Phipson's papers, 1893-94.

"Zeitschr. Deutsch. geol. Gesell., vol; 40. pp. 030-634, 18S8.

"Phil. Mag., 5th ser., vol. 50, pp. 312, 399, 1900; 6th ser., vol. 4, p. 435, 1902; vol. 9, 

p. 88, 1905 ; vol. 11, p. 226, 1905.

"Phil. Mag., 5th ser., vol. 47, pp. 85-89, 1899.
TPIE ATMOSPHERE. 51

phere 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. Sn^th0 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., Avould 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,** 

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 dis-. 

cussed in the proper chapter. For the present it is enough to see 

that cogent arguments may lead us to either of tAvo 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, Ave are likely to conclude that the 

atmosphere is merely a residuum of uricombined gases which Avere 

left behind Avhen the globe assumed its solid form. That, I think, 

is the prevalent opinion, although it must be modified by the observed 

facts of A^olcanism. The outer envelope of the earth receives reinforcements from Avithin, Avhose sources will be considered at length 

in another .chapter. . . Quite a different theory of the earth's origin has lately been deA^eloped by T. C. Chamberlin,0 Avho imagines a planet built up.by

"Jour. Geol., vol. 13, p. 319, 1905. 

6 Me"m. Soe. lng<5n. civils France, October, 1903, p. 346.

c Jour. Geol., vol. 5, p. 653, 1897; vol. 6, pp. 459, 609, 189S : vol. 7, pp. 545, 667, 

751, 1899. See also H. L. Fail-child, Am. Geologist, vol. 33, p. 94, 1904,
52 THE DATA OF GEOCHEMISTRY.

slow aggregations of small, solid bodies. Each of these particles, 

or meteorites, carried with it entangled or occluded atmospheric material. In time the accumulation of originally cold matter developed 

pressure enough to raise the central portions of the mass to a high 

temperature, and gases were then expelled. Thus the atmosphere 

was generated from within the globe instead of remaining as a 

residuum around it. We know that meteorites contain occluded 

gases, and that gases are also extractable from igneous rocks, and 

these facts lend to the hypothesis a certain plausibility. The gases 

thus obtainable from the lithosphere are equivalent to many potential 

atmospheres, although, as we have already seen, oxygen is not among 

them. On Chamberlin's hypothesis the atmosphere has grown from 

small beginnings; the nebular conception assumes that it was largest 

at first.

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 Ave 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,a later by A. 

Bitter,6 and has been more recently developed by S. Arrhenius.0 It 

has, however, only speculative value, for it rests upon assumptions 

which can not be tested experimentally. If the conception be entertained, then the possibilities of speculation about additions to the 

atmosphere are greatly increased. A discussion of that sort falls 

without the scope of this memoir, and only these brief references are 

admissible here.

"See his essays on the nebular hypothesis (1858) and the constitution of the sun 

(1805). Cited from New York edition of 1892. 

" Wied. Annalen, vol. 5, p. 405, 1878. 

"Geol. Foren. Forhandl., vol. 22, p. 395, 1900.
CHAPTER III.

LAKES AND RIVERS.-1

ORIGIN.

When rain falls upon the surface of the earth, bringing with 

it the impurities noted in the preceding chapter, part of it sinks 

deeply underground to reappear in springs. Another part .runs off 

directly into streams, a part is retained as the ground water of soils 

and the hydration water of clays, and a portion returns by evaporation to the atmosphere. According to an estimate by Sir John Murray,6 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, 762,587 tons of foreign matter. In all, nearly 5,000,000,000 

tons of solid substances are thus carried annually to the ocean. 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 Avater, 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 

data are abundant, but unfortunately complicated by a lack of unia Excluding those belonging to closed basins. 

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

53
54 THE DATA OF GEOCHEMISTRY.

formity 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 suppositions 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 

Avith 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 which their 

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

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

to the several bases according to his individual judgment. The 

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 few.

But are the radicles combined ? This is a point at issue. Although 

no complete theory, covering all the phenomena of solution, has yet 

been developed, it is the prevalent opinion, at least among physical 

chemists, that in dilute solutions the salts are dissociated into their 

ions, and that with the latter only can we legitimately deal. 

Whether this theory of dissociation shall ultimately stand or fall is 

a question which need not concern us now; we can use it without 

danger of error as a basis for the statement of analyses, putting our 

results in terms of ions which may or may not be actually combined.0 

Upon this foundation all water analyses can be rationally compared, 

with no unjustifiable assumptions and with all the real data reduced 

to the simplest uniform terms. We do not, however, get rid of all 

difficulties, and some of these must be met by pure conventions. For 

example, Is silica present in colloidal form, or as the silicic ion SiO;! ? 

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

salts? The iron may represent ferrous carbonate, the alumina may

a 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. Mitth., vol. 11, p. 

487, 1890. It is now rapidly supplanting the older system.
LAKES AISTD EIVEES. 55

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 composition of the anhydrous inorganic matter which is left when a water 

has been evaporated to dryness, the difficulty as regards iron disappears, for ferrous carbonate is then decomposed and ferric oxide 

remains. A similar difficulty in respect to the presence of bicarbonates also vanishes at the same time, for the bicarbonates of calcium 

and magnesium can only exist in solution and not in the anhydrous 

residues. If, in a given water, notable quantities of lime, magnesia, 

and carbonic acid are found, bicarbonic ions must be present, for 

without them the bases could not continue dissolved; but after evaporation only the normal salts remain. Sodium and potassium bicarbonates are not so readily broken down; but even with them it is 

better to compare the monocarbonates, so as to secure a uniformity 

of statement. In fact, some analysts report only normal salts, and 

others bicarbonates; so that for the comparison of different analyses , 

we are compelled to adopt an adjustment such as that which is here 

proposed. In other words, we eliminate the variable factors, and 

study the constants alone.

One other large variable remains to be considered the variation 

due to dilution. A given solution may be very dilute at one time, and 

much more concentrated at another, and yet the mineral content of 

the water is possibly the same in both cases. For example, average 

ocean water contains 3.5 per cent of saline matter, while that of the 

Black Sea carries little more than 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,0 which he himself 

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

the results are given in oxides, etc., as in a mineral analysis, and in

. "Bull. No. 82, Colorado Agi-ic. Expei-. Sta., p. 56, 1903.
56 THE DATA OF GEOCHEMISTRY.

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. 

;

SiO,.---,....---... 1.26

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

C08 ............... 8.78

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

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

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

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

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

B0-.............. .53

SiO,... .......

CAbU3 ..........

co,:,. .......

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

Na2 0. .........

KjO.... ......

CaO. .........

MgO ......'...

(FeAl)AMn203 ........

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. 987 

. . . . .604

. 73.363

CaS04 .... ......

MgS04 . ........

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

Na,S04 . ........

NaCl. ..........

Na2C03 . ........

Na2Si03 ........

(FeAl) 2 03 ......

Mn203 ..........

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 }^et the analytical data are the same. A change 

in the last column of SiO2 into the radicle Si03 would affect the other 

figures but slightly. The compactness and simplicity of the ionic 

form of statement are evident at a glance. Under it, as " salinity," 

I have given the concentration of the water in terms of parts per 

million. One million parts of this water contain in solution 1,014 

parts of anhydrous, inorganic, solid matter.

SPRINGS.

When water first emerges from the earth as a spring its mineral 

composition is dependent upon local conditons. Some spring waters 

are exceedingly dilute; others are heavily charged Avith 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.
LAKES AND RIVERS. 57

Analyses of spriny 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 IT. 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.

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

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

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

Ca ....................................... Mg.... .....:. ....................:.......

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

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

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

A12O3 ....................................

Fe2 03 ....................................

A.

53.59

3.40

1.35

30. 95

3.45

1.08

.63

5. 55

100.00

B.

47 J 4

6.67

4.18

22.67

6.17

1 5.32

7.85

100.00

f)Q(\

C.

27.29

16.37

1.50

14.39

2.23

5.72

3.97

27.17

1.36

100.00 

80

]).

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

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 ions 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 Avidely, but the most concentrated 

example contains only 925 parts per million, or 52 grains to the 

United States gallon, of foreign solids. It will be seen as we go 

farther that carbonate waters are the most common, for the reason 

that rain water brings carbonic acid from the air, and that substance 

is most active as a solvent of mineral matter.

CHANGES OF COMPOSITION.

As spring water flows from its source it rapidly changes in character. It receives other water in the form of rain or of ground water 

flowing from the soil, and it blends with other rivulets to produce 

larger streams. Under certain conditions a part of its dissolved load, 

may be precipitated, and the composition of a "river as it approaches 

the sea represents the aggregate effect of all these agencies. A river 

is the average of all its tributaries, plus rain and ground water, and 

many rivers show also the effects of contamination from towns and 

factories. Small streams are the most affected by local conditions, and 

show the greatest differences in composition; large rivers, as a rule, 

resemble one another more nearly.

How rapidly and how profoundly the composition of a river may 

be modified are well illustrated in Headden's bulletin, Avhich I have 

already cited.0 Cache la Poudre River in Colorado flows first through 

a rocky canyon, over bowlders of schist and granite, and thence

o Bull. No. 82, Colorado Agric. Exper. St;a., 1903.
58 THE DATA OF GEOCHEMISTRY.

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 56 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 River, 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.

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

SOg.. ..................... .........................

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

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

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

NaaO ...............................................

K2O ................................................

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

(JUVe)^.. .........................................

Mn,03 :.............................................

Less 0=C1 ..........................................

' A.

0.6029

.1946

.1037

.5238

.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

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.

C03 - ................................................

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

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

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

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

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

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

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

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

Ro03 ................................................

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

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 3d

59.99

2.52

12. 31

6.65

9.84

.34

.94

.07

100. 00 

1,571

10.34 sd <*<i

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

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
LAKES AND KTVEES. 59

shown in Headden's analyses of water from Arkansas River, first at 

Canyon, where it emerges'from the mountains, and second at Rockyford, nearly 100 miles below.0 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 Si02 and the SiO;i radicle may be neglected.

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

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

so..................... .......................................................... ci..............................................................................

Pn

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

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

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

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

RjA) ...........................................................................

Canyon.

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.6 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 :

Analyses of ivater from River Chelif, 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.

C 0 i ......................................................................

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

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

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

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

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

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

FeoOa- ...................................................................

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

22.61

.04

.04

100. 00 

5,342

C.

9.31

29.64

26. 54

11.85

4.J1

17.03

1.18

100.00 

1,182

"Bull. No. 82, Colorado Agric. Exper. Sta., 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, p. 169, 1903.

"Bull. Soc. geol. France,- 2d ser., vol. 14, p. 352, 1857. A later analysis by Balland 

is given in Jour. Chem. Soc., vol. 3G, p. 699, abstract, 1879. Still another, by F. de 

Mnrigny, is cited by Both. In Ann. mines, 5th ser., vol. 11, p. 667, 1857, Marigny gives 

analyses of two other Algerian rivers.
60 THE DATA OF GEOCHEMISTRY. -

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 laken 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.

ANAJjTSES OF KIVEK 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. All are here reduced to a uniform standard; 

but the original statements of quoted analyses can usually be found 

through the references to 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 St. Laivrence River and the Great Lakes.

A. Lake Superior ° at Sault Ste. Marie, Michigan. Average* of five analyses of samples 

taken one month apart, in 1906 and 1907.

B. Lake Michigan at St. Ignace, Michigan. 6 Average of five monthly analyses, 1906-7. 

C. Lake Huron at Port Huron, Michigan. Average of four monthly analyses, 1906. 

D. Lake Erie at Buffalo, New York. Average of six monthly analyses, 1906-7.

a Other analyses of Lake Superior water have been made by W. A. Noyes, Eleventh Ann. 

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

Water-Supply and Irrigation Paper No. 31, U. S. Geol. Survey, p. 27, 1899; and by G. L. 

Heath, Rept. State Board, Geol. Survey Michigan, 1903, p. 119.

6 Analyses of Lake Michigan water at Milwaukee and of Milwaukee River, by G. Bode, 

are published in Geology of Wisconsin, vol. 1, p. 308, 1883. Another analysis of the 

lake water, by J. H. Long, is given in Report on the Boiler Waters of the Chicago, Burlington and Quincy Railroad, published by that company in 1888.
LAKES AND RIVERS. 61

. E. St. Lawrence River at Ogdensburg, New York. 'Average of six monthly analyses, 

.1906-7. Analyses A to E by R. B. Dole and M. G. Roberts, in the water-resources branch 

of the United States Geological Survey.

F. The St. Lawrence at Pointe des Cascades, near Vaudreuil, above Montreal. Analysis 

by T. Sterry Hunt, Phil. Mag., 4th ser., vol. 13, p. 239, 1857.

G. The St. Lawrence opposite Montreal. Analysis by Norman Tate, cited by T. Mellard 

Reade, In Evolution of Earth Structure, 1903.

p/-\

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

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

NO;,...................-........

Mg ...... .........:...........

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

SiO- ...........................

PCoO;,. .........................

Salinity, parts per million. . . . .

A.

A& f)(l

4.33

1.69

.56

25.78

4.96

1 4.96

12. 33

.13

100.00

68

B.

48.82

5.67

2.01

.22

23.42

6.94

1 3.65

.05

100.00 

116

C.

48.99

5.64

2.19

.30

23.11

6.35

1 3.21

.07

100.00 

. 105

D.

45. 64

9.48

5.40

.1.2

23. 79

5.61

1 4.84

5.14

Oft

100.00 

134

E.

46.43

9.64

4.10

19

24. 28

5.46

1 4.76

5.09

.05

100. 00 

132

F.

41 66

5.19

1.51

20.08

4.52

3. '20

.72

OO I f)

100. 00 

160

G.

44.43

11. 17

2.41

20.67

0. 44

4.87

10.01

100. 00 

148

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. Rept. Minnesota Geol. Survey, 1882, p. 174.

I. Maumee River near Toledo, Ohio. Analysis by C. F. Chandler, Ninth Ann. Rept. 

Waterworks Board, Toledo, 1881.

,T. Genesee River at Rochester, New York. Analysis by C. F. Chandler, quoted by L C. 

Russell in Mon. TJ. S. Geol. Survey, vol. 11, opp. p. 176, 1885.

K. Ottawa River at St. Anne, near the head of Montreal Island. Analysis by T. S. 

Hunt, quoted by Russell, loc. cit.

L. Lake Champlain. Average of live analyses of samples taken in the broad lake, by 

M. 0. Leighton, Water-Sup, and I IT. Paper No. 121, U. S. Geol. Survey, 1905. This 

paper also contains analyses of water from the upper end of the lake, of Bouquet River, 

and of Ticonderoga Creek.

co3 ...... ........................................... 804..................:..............................

Cl .........:........................................

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

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

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

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

Feo6s .. .............................................

A12 03 ...............................................

H.

42.00

4.69-

6.09

18.08

5.74

5.13

2.55

14.15

\ 1.57

100. 00 

51

I.

42.39'

13.38

2.39

25.26

4.23

1.54

2.95

6.91

100. 00 

105

J.

37.94

26.29

1.41

24.48

5.29

2.59

1.35

.82

}

QO

100.00 

170

K.

36.25

3.19

1.24

16.22

3.25

3.91

2.25

33.69

100. 00 

61

L.

45.81

11.03

1.78

21. 19

4.21

1 '8.80 J'

5.58 1 1. 60

*

100. 00 

 67

Between these waters there is a distinct resemblance, in that carbonates are the predominating salts and calcium is the chief metal. 

Ottawa Eiver is characterized by high silica; but the Genesee and the

0 Other tributaries that have been analyzed are. as follows: Goose Lake, Michigan (Geol. 

Survey Michigan, vol. 8, pt. 3, p. 235, 1903) ; Torch Lake, Portage Lake, Pine River, 

Thunder River (Rept. State Board, Geol. Survey Michigan, 1903) ; Traverse Bay, Detroit, 

Sbiawassee, Grand, Cass, Chippewa, Tittabawassee, and Boardman rivers, Manistee and 

Muskegon lakes (Water-Sup, and Irr. Paper No. 31, U. S. Geol. Survey, 1903).
62 THE DATA OF GEOCHEMISTRY.

Maumee, which flow through areas of sedimentary rocks, contain a 

larger proportion of sulphates. The increase in salinity or concentration in passing from Pigeon Elver, at the head of Lake Superior, 

to the St. Lawrence at Montreal is also noteworthy. The two Montreal analyses, F and G,.are, however, far from concordant and can 

not be given much weight.

According to estimates made by engineers of the United States 

Army, the flow of the St. Lawrence past Ogdensburg is 248,518 cubic 

feet per second. This, with a salinity of 132 parts per million, corresponds to a transport of dissolved matter of 29,278,000 metric tons 

annually. The area drained, exclusive of water surface, is 286,900 

square miles, and from each square mile 102 tons is 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 rather scanty. 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 thirty-eight 

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.

D. Merrimac River above Concord, New Hampshire. Analysis by H. E. Barnard for 

M. O. Leighton.

E. Hudson River at Albany, New York. Analysis by C. F. Chandler, Rept. Am. 

Public Health Assoc., vol. 1, pp. 533-563. 

P. Hudson River at Hudson, New York. Thirteen samples, each representing a composite of ten daily collections, taken between September 17, 1906, and January 27, 1907. 

Average analysis by R. B. Dole and M. G. Roberts, in the laboratory of the water-resources 

branch, United States Geological Survey.

G. Mohawk River at Utica, New York. Analysis by C. F. Chandler, quoted by I. C. 

Russell in Mon. U. S. Geol. Survey, vol. 11, opp. p. 176, 1885.

H. Croton River, 1872. Analysis by C. F. Chandler, Rept. Am. Pub. Health Assoc., 

vol. 1, pp. 533-563. Another analysis of water taken in 1869 appears in the same 

report.

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

S04 ..-. ..............................

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

Ca 3...... ............................

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

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

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

A1 O,

Fe2 03 ...............................

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

A.

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.

30.12

6.16

19.61

3.08

6.65

2.59

23.53

1 8.26

100. 00 

41

D.

28.15

' 12. 78

8.78

17.14

4.18

6.16

18.14

1.34

3.33

100.00 

170

E.

38.98

13.52

6 24

24.23

4.99

2.61

7.51

1 1.29

100. 00 

93

F.

35.43

16.53

3.34

.96

20.35

3.82

}

7 91

11.47

.19

100. 00

G.

14.48

' 1.78

24.64

5.34

2 79

.69

5.18

1 1.00

100.00 

129

H.

46. 71

4

QO

5:69

19 26

7.26

3.96

3.02

7.34

1 1.93

^

100.00 

52
LAKES AND RIVERS. 68

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, and yet in its analyses no carbonates were reported. Its salinity is low, and it may be that the-waste from factories and pulp mills along its banks have converted all of its original 

carbonates into sulphates.. Its basic radicles are largely in excess of 

the acid radicles S04+C1, and it is therefore probable that equilibrium is maintained by the silica, which, if recalculated into the radicle 

Si03 , is more than sufficient to restore the balance. As stated, the 

analysis is questionable. The Mohawk and Croton are tributaries 

of the Hudson.

Analyses of ivaters from Atlantic slope II.

I. Delaware River near Trenton, New Jersey." Analysis by H. Wurtz, Am. Jour. Sci., 

2d ser., vol. 22, p. 125, 1856.

J. The Delaware at Lambertvilie, New Jersey. Average of fourteen analyses by 

Dole and Roberts, each sample a composite of ten daily collections between' September 

8, 1906, and February 9, 1907.

K. Susquehanna River at Danville, Pennsylvania. Average of twenty composites 

analyzed by Dole and Roberts, the samples having been taken between September 10, 

1906, and April 3, 1907.

L. 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 

Outwater, Water-Sup, and I IT. Paper No. 192, U. S. Geol. Survey, pp. 296-297, 1907. 

This 'report contains thirty-four other analyses of water from the upper Potomac and 

its important tributaries.

M. James River, Virginia." Richmond water supply. Analysis by W. H.' Taylor, 

Rept. to Richmond Board of Health, 1877.

N. James River at Richmond, Virginia. Average of sixteen analyses by Dole and 

Roberts, each sample formed from ten daily collections between September 10, 1906, and 

February 18, 1907.

 0. Cahaba River near Leeds, Alabama. Analysis by R. S. Hodges. Geol. Survey Alabama, Underground water resources, 1907. This report contains many analyses of 

springs and wells.

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

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

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

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

rjr\ fft::::::::::::::::::::::::::::

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

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

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

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

A\20»................ ..........

Fe2O3 ..........................

Salinity, parts per million. . . . .

' I.

44.70

3.93

2.12

 2. 61

38.89

7.63

1.20

3.12

14.92

1 .82

100. 00 

57

J.

30.66

17.81

3.49

1.66

17. 80

4.96

1 7.41

16.01

.20

100. 00 

65

K.

25.18

26. 82

5.00

2.90

17.63

4.50

1 8.33

9.54

.10

100. 00 

106

L.

44.37

7.68

4.44

27.40

4.08

2.83

.55

4.56

1 4.09

100.00 

115

M.

' 42. 52

5.26

1.51

3.32

18.49

5.44

3.52

3.58

14.74

.58

.96

.08

100.00 

69

N.

36.08

7.36

2.00

.48

17.68

4.00

1 5.12

26.32

.96

100. 00 

86

0.

41 91

.90

 1.85

21.33

'4.22

2 nn

1.89

24.22

1 1.68

100. 00 

cl90

"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.

b A thesis by A. F. White, Washington and Lee University, 1906, contains, partial 

analyses of tributaries of the James near Lexington, Virginia.

c With carbonates normal. In the original, with bicarbonates, the salinity is given as 272.8 parts 

per million.
64 THE DATA OF GEOCHEMISTRY.

Among these analyses that of the Susquehanna is noticeable on 

account of the high proportion of sulphates shown. This peculiarity 

may be abnormal and due to contamination by drainage water from 

the coal mines above Danville. The Potomac water strikingly resembles that of the St. Lawrence and the Great Lakes. According to 

estimates made by Outwater, the Potomac annually carries past Point 

of Rocks 771,000,000 kilograms of dissolved matter and 212,000,000 

kilograms of solids in suspension, or sediments. The sum of the two 

quantities is 983,000 metric tons, or a little over 102 metric tons per 

square mile of the territory drained. The dissolved matter corresponds to 80 tons per square mile.

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 : a

Analyses of water from Mississippi River.

A. Mississippi River at Brainerd, Minnesota. Analysis by C. F. Sidener, Thirteenth 

Ann. Kept. Geol. Nat. Hist. Survey Minnesota, p. 102, 1884.

B. Mississippi River above Minneapolis.

C. Mississippi River below Minneapolis. Analyses B and C by J. A. Dodge, Tenth 

Ann. Rept. Geol. Nat. Hist. Survey Minnesota, p. 207, 1882. In recalculating these two 

analyses small amounts of organic matter were rejected.

D. Mississippi River at Minneapolis.'' Average of twenty-three analyses, by W. M. 

Barr, H. S. Spaulding, and W. Van Winkle, of samples each formed by ten daily collections between September, 1906, and May, 1907.

E, Mississippi River at Memphis, Tennessee. 6 Average of seventeen ten-day composites, formed between October 29, 190(3, and May 10, 1907. J. R. Evans, analyst.

F. 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.

G. Mississippi River above New Orleans.'' Average of fifty-two weekly composites of 

samples taken daily between April, 1905, and April, 1906. Analyses by J. L. Porter, 

The average composition of the water for an entire year.

"Bailey Willis (Jour. Geol., vol. 1, p. 509, 1893) cites some imperfect analyses of the 

Mississippi and Missouri near St. Louis. Iowa Geol. Survey, vol. 6, p. 365, 1896, contains other analyses of Mississippi water, and also of Missouri, Cedar, Des Moines, Coon, 

Boyer, Wapsipinicon, Skunk, Chariton, Grand, Nodaway, and West Nishnabotna rivers. 

These too are incomplete. The early analyses of Mississippi water by Avequin and by 

Jones are of no value for present purposes. Partial analyses, containing some useful 

data, are given in Report of the sewage and water board, New Orleans, 1903. These 

relate to the lower Mississippi near New Orleans.

6 Analyses D, E, and G were made for the water-resources branch of the United States 

Geological Survey.. 1 am indebted to Messrs/M. O. Leighton and R. B. Dole for the 

privilege of using them.
LAKES AND BITERS. 65

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

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

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

NO..............................

P04 ............ ................

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

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

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

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

A1.0«. ......:.............. ....

Feo03 . ........... ..............

Mn304 . ...... ..................

Salinity, parts per million. ....

A.

51.05

1.05

.48

22.94

4.09

5.14

1.75

9.40

2 01

1.49

100.00 

195

B:

55. 62

1.80

.91

23.38

8.24

1.77

.76

7.16

.36

100. 00 

188

C.

52.76

2.04

1.08

trace

23.90

6.75

1.81

1.28

9.46

.92

100. 00 

177

D.

47. 04

9.61

.85

.85

20.59

7.67

1 5.33

8.01

.05

100. 00 

200

E.

32.02

11.31

o.72

.10

17.45

6.98

1 6. 19

19.45

.78

100. 00 

197.

F.

30.27

19. 69

11.05

.27

20. 25

4.66

6.86

1.57

5.07

.12

.08

.11

1.00. 00 ' 

146

G.

34.74

14.90

6.23

1.57

20. 42

5.21

4.92

4. 65

6.77

.44

.15

100. 00 

166

In the foregoing table some of the figures appear to be questionable. The excessive chlorine in F, the silica in E, and the potassium 

in G are doubtful, In the ordinary or usual statement of water

analyses variations like these from the normal are not easily recognized and may escape notice, but as percentages of total solids they 

distinctly appear. However, the. table tells a definite story. The 

upper Mississippi is low in chlorides and sulphates, which tend to 

accumulate in the lower stream. The chlorides come in part from 

human contamination, a subject to be considered later; and at New 

Orleans there is probably some " cyclic sodium " brought in rainfall 

from the Gulf of Mexico. As a whole, the Mississippi water is 

mainly \) a calcium -carbonate water, 

' with all else subordinate. If we

accept the figures given by J. L. Greenleaf,ft 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 Avithin the State of Minnesota. 6

Analyses of waters tributary to upper Mississippi River.

A. Lake Minnetonka. Analysis by W. A. Noyes, Geology of Minnesota, vol. 2, p. 311, 

1888.

B. Millelacs Lake. Analysis by .T. A. Dodge, Geology of Minnesota, vol. 4, p. 38,1899.

C. Bigstone^Lake. Analysis by C. F. Sidener, Thirteenth Ann. Kept. Geol. Nat. Hist. 

Survey Minnesota, p. 98, 1884. Empties into Minnesota River.

D. Heron Lake. Analysis by Noyes, Eleventh Ann. Kept. Geol. Nat. Hist. Survey 

Minnesota, p. 178, 1882. Empties into Des Moines River.

E. Rock River at Luverne. A tributary of Sioux River. Analysis by Noyes, Geology 

of Minnesota, vol. 1, p. 550, 1884.

"Am. Jour. Sci., 4th ser., vol. 2, p. 29, 1896. 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.

" For analyses of several other Minnesota waters, see Water-Sup, and Irr. Paper No. 

193, U. S. Geol. Survey, p. 133, 1907.

14399 Bull. 330 08 5
66 THE DATA OF GEOCHEMISTRY.

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

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

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

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

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

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

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

Si03 .... ............................................

Fe208 . - .............................................

A1 203 ................... ............................

A.

' 58. 81

.72

25.52

7.23

1.03

2.32

4.37

100. 00 

110

B.

59.03

.88

.59

15. 25

10.71

6.68

2.24

2.97

1.65

100. 00 

144

C.

20.13

34.36

1.65

8.00

8.61

6.69

1.01

 19. 26

.29

100.00 

554

.D.

42.65

18.62

1.14

1.39

20.71

8.00

2.94

1.32

2.61

\ .62

100.00

272

E.

47.94

8.64

.44

20. 51

7.43

3.31

.51

7.65

3.21

.36

100.00 

275

In the following table I give analyses of waters which reach the 

Mississippi from the eastward by way of the Ohio. For the Ohio 

itself I have found no satisfactory data.

Analyses of 'waters tributary to Ohio River.

A. Monongahela River at Fairmont, West Virginia. Analysis by C. D. Howard, 

Bull. No. 89, West Virginia Agric. Exper. Sta. This bulletin also contains analyses of 

water taken at Morgantown, but showing contamination.

B. Wabash River at Vincennes, Indiana. Average of nineteen composites, made up of 

ten daily samples in each, taken between September 9, 1906, and May 8, 1907. Analyses 

by W. M. Barr, H.-S. Spaulding, and W. Van Winkle.

C. Kentucky River at Frankfort, Kentucky. Average of sixteen composites, as in B, 

taken between September 28, 1906, and February 11, 1907. Analyses by R. B. Dole and 

M. G. Roberts. Analyses B and C represent work done under the water-resources branch 

of the United States Geological Survey.

D. Cumberland River at Nashville, Tennessee. Analysis by N. T. Lupton, quoted by 

I. C. Russell in Mon. U. S. Geol. Survey, vol. 11, opp. p. 176, 1885.

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

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

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

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

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

Na........... .............'...................................

K. ..................... ....s.. .......... ....

SiO*. ..........................................................

Al.,03 .........................................................

Fe,03 .........................................................

A. '

17.47

35.35

4.10

16.90

4.37

5.22

' 14. 63

} 1.96 '

100. 00

78

B.

31.27

17.12

19 81

2 ^2

17.31

6.29

1 8.87

4.04

.17

100, 00 

341

C.

39.06

7.32

1 49

o re

22.62

4.06 } ta

15.32

94

100. 00

D.

47.25

4.65

2.47

24.65

 > 31

8.51

.41

} 5.54 '

100. 00 

121

For the largest tributary of the Mississippi the Missouri several analyses are available.* They are given in the following table, 

together with analyses of other affluent waters.

Analyses of toater from Missouri River and tributaries.

A. Missouri River at Great Falls, Montana. Analysis by Edgar and Mariner, cited in 

Eighteenth Ann. Rept. U. S. Geol. Survey, pt. 4, p. 612, 1897.

B. Missouri River at Bismarck, North Dakota. Analysis by C. F. Sidener for the 

Northern Pacific Railway. Received through M. 0. Leighton.

0 Another analysis of Missouri River water, by F. W. Traphagen, is cited in E. W. 

Hilgard's " Soils," p. 23, but the point of collection is not named.
LAKES AND KIVEKS. 67

 C. Missouri River at Florence, Nebraska, near Omaha. Average of twenty composites, 

each of ten daily samples, analyzed by W. M. Barr and W. Van Winkle for the waterresources branch of the United States Geological Survey. Samples taken between 

October, 1906, and April, 1907.

D. Missouri River at Ituegg, Missouri, near its month. Average.of twenty-one composites, like C, analyzed by W. M. Barr, II. S. Spaulding, and W. Van Winkle. Samples 

taken between September, 190(5, and May, 1907.

E. Laramie River 20 miles above Laramie, Wyoming. Average of three analyses by 

10. E. Slosson, Bull. No. 24, Wyoming Exper. Sta., 1895.

F. Laramie River 50 miles below Laramie. Analysis by E. E. Slosson, loc. cit."

G. Platte River at Fremont, Nebraska. b Average of sixteen composites like C and D. 

Analyses by W. M. Barr and W. Van Winkle for the water-resources branch, United 

States Geological Survey.

H. Ye.llowstoite Lake. Analysis by .T. E. Whitnelcl, Bull. U. S. Geol. Survey No. 47, 

1888."

cos ...... ...........................

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

01.......... .I....... ................

N03 -...- ............................

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

^Sn......... ..........................

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

NH4 . ......................./........

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

AU);l ..... ...........................

FeoOa...- ............................

A.

27.10

25. 45

7.62

8.93

5.48

\ 17. 13

j

8.29

100. 00 

113

B.

27.78

34.50

3.44

17.90

5.72

| 8.49

2.05

100. 00 

440

C.

.22.63

38.23

1.96

.30

14.72

4.87

1 10.42

6.70

.17

100. 00 

499

D.

25. 94

29.15

3.67

.80

15. 21

'4.89

1 10. 16

9.83

.35

100. 00 

305

E.

27.35

11.16

3.11

33.75

2.45

7.34

.85

31.73

} 2.26

100. 00 

212

P.

19.59

37.48

6.32

15. 07

5.10

8.82

1.96

4.54

1 1.12

100. 00 

429

G.

28.22

24.73

2.21

.22

16. 18

4.36

1 10. 20

13.77

.11

100. 00 

335

H.

20.93

7.12

7.96

7.29

.25

13. 22

3.99

.34

35. 5.1

3.39

100. 00

118

"Slosson also gives analyses of 1'opo Agie and Little Goose creeks. Another analysis 

of the Laramie is printed in Fifth Rent. Bureau of Soils, U. S. Dept. Agric.. 1908. 

1 b An analysis of the Platte at Greeley, Colorado, is given on p. 58, ante, together with 

some of Cache la Poudre River.

c This bulletin also contains analyses of water from Firehole and Gardiner rivers.

In all but two 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 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 carefully studied by E. H. S. Bailey and 

E. C. Franklin,* whose data, reduced as usual, are given below. It 

should be observed, however, that the analyses are not quite complete ; the sodium Avas 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.

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.

"Kansas Univ. Quart., vol. 3, p. 91, 1894.
68 THE DATA OF GEOCHEMISTRY.

If. Delaware River ° at. Perryville. Analysis by J. B. 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.

rtr\

S04 - .......-.-..-....-....--......-..

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

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

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

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

tiin -

(AlPe)i,03 . ....... ...................

A.

16.07

24. 52

22. 41

13.36

2.62

17.81

2.03

.68

100. 00 

1,01.7

B:

13.70

16.94

34:61

5.62

1.88

26. 07

.98

.20

100. 00 

2,323

C.

14.12

23. 36

24.55

11.68

2.16

20.15

3.63

.45

100. 00 

1,105

D.

31. 41

13.71

10.02

15.62

3.19

13.06

11.61

1.38

100. 00 

554

E.

35.41

16.17

6.48

18.90

4.91

7.89

8.59

1.65

100. 00

F.

44.54

11.28

6.03

23. 14

5.49

4'. 76

Q QQ

1.37

100.' 00 

396

G.

42.66

7.59

6.69

23.27

3. 12

12. 81

9 77

1.09

100.00 

499

H.

23. 83

18.15

18.80

3.51

15. 45

4.83

.67

100. 00 

766

" Not to be confused with the eastern- river of the same name.

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 Eiver 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 all the 

waters which flow into it..

Two analyses of water from the Arkansas Eiver, 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: 0

Analyses of water from Arkansas River and tributaries. 

A. Arkansas River at Canyon; Colorado.

B. Arkansas River at Rockyford, Colorado. Analyses A and B by W. P. Headden, 

Bull. No. 82, Colorado Agric. Exper. Sta., 1903.

C. Arkansas River at Little Rock, Arkansas. High water, December 20, 188S.

D. Arkansas River at Little Rock. Low water, August 22, 1888. Analyses C and 1") 

by R. N. Brackett, Ann. Rept. Arkansas Geol. Survey, 1891, vol. 2, pp. 159, 160. Recalculated here to standard form. According to .T. C. Branner (idem, p. 164), the river carries 

in solution past Little Rock 6,828,350 tons annually.

E. Arkansas River at Little Rock. Average of 13 composites of ten daily samples 

each, taken between November, 1906, and May, 1907. Analyzed by W. M. Barr, H. S. 

Spaulding, and W. Van Winkle, for the water-resources branch of the United .States 

Geological Survey.

F. Neosho River at Chanute, Kansas. A tributary of the Arkansas. Analysis by C. F. 

Gustavsen, Kansas Univ. Sci. Bull., vol. 2, p. 243/1903. Reduced from bicarbonate form.

G. Red River at Shreveport, Louisiana. Average of 6 ten-day, composites, analyzed 

for the water-resources branch of the United States Geological Survey by J. R. Evans. 

Samples taken between January 31 and May 8, 1907.

" Partial analyses of about 50 streams in Oklahoma may be found in Water-Sup, and 

Irr. Paper No. 148, U. S. Geol. Survey, 1905.
LAKES AND RIVERS. 69

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

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

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

NO;,.. ............ .............

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

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

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

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

Si03 ...........................

AloO;, ..........................

Fe-A,.... ......................

Salinity, parts per million .....

A.

37.55

14.62

q 77

'20. 24

5.13

9.57

.60

8.19

1 33

/ ' 33

100.00 

148

B.

2.65

60. 69

4 89

19 7ft

3.76

14.50

.28

.45

100. 00 

2,134

C.

20.92

8.15

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. 94

13.54

33.78

.36

8.91

2.26

1 22.95

5.85

.41

100.00 

559

F.

21. 74

16.08

2.78

15. 76

.10

7 91

26.02

| 9.61. '

100. 00 

306

G.

17. 29

24. 44

14.58

.04

to QJ

5.72

1 12.05

10. 55

1.39

100. 00 

318

SOUTHWESTERN RIVERS.

A few of the rivers of southwestern United States have been 

studied with much care. The subjoined analyses represent this

group.

Analyses of water from soiithwestern rivers.

A. Brazos River at Waco, Texas. Average of 14 composites of ten dally samples each, 

taken between December, 1906, and May, 1907. Analyses by W. M. Barr, H. S. Spauld- 

 Ing, and W. Van Winkle, for the water-resources branch of the United States Geological 

Survey.

B. Rio Grande at Mesilla, New Mexico." Average composition for an entire year, June, 

1893, to .Tune, 1894. Analyses by Arthur Goss, Bull. No. 34, 1900, New Mexico Agric. 

Exper. Sta. This bulletin also contains analyses of water from Animas River, Santa Fc 

River, and' Rio Bonito.

C. Pecos River, New Mexico. Average of six samples analyzed by Goss, loc. cit.

D. Colorado River at Yuma, Arizona. Average of seven composite samples, covering 

collections made between January 1.0, 1900, and January 24, 1901. Analyzed by R. H. 

Forbcs and W. W. Skinner, Bull. No. 44, Univ. Arizona Agric. Exper. Sta., 1.902. The 

average composition of the water during a year.

E. 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.

F. 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 SiO;! . This is reduced to S102 in 

the table.

CO., ......................................

so4 ...... ...............................:. PI

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

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

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

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

K ........................'.............,..

<sir>

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

Fc203 ...... ...............................

A.

8.83

20.74

33. 71

.15

9.54

2.04

1 23. 27

1.69

.03

100. 00 

1,066

B.

17. 28

31. 33

13.55

14.78

2.05

 14. 43

1.95

1 4.63

.

100.00 

399

C.

1.54

43/73

22.56

ifds

3.62

14.02

.77

}

QO 

..u

100. 00 

2,834

IX

13.02

28. 61

. 19. 92

10.35

3.14

19.75

2.17

3.04

100. 00 

702

E.

12.10

16. 07

29.78

8.03

2.52

24.53

2.31

4.60

100. 00 

1,023

F.

9. 61

8.29

41. 56

7.15

2.69

26.38

1.38

2.94

100. 00 

1,234

n An analysis of Rio Grande water by 0. Loew is given in Rept. U. S. Geog. Surv. W. 

100th Mer., vol. 3, p. 576, 1875. In the annual report of the same survey for 1876 

Loew gives an analysis of water from Virgin River, a tributary of the Colorado.

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
THE DATA OF GEOCHEMISTRY.

Gulf of California annually, in solution, 13,416,400 metric tons of 

salts, or about 59.6 metric tons from each square mile of its basin.

THE PACIFIC SLOPE.

The next table contains analyses of waters tributary to the Pacific 

Ocean.

Analyses of ivaters tributary to Pacific Ocean.

A. Yukon River at Eagle, Alaska. Analysis by G. Steiger. Reported by F. W. Clarke, 

.Tour. Am.'Chem. Soc., vol. 27, p. Ill, 1905.

B. Cedar River, Washington. Analysis by H. G. Knight, Rept. Washington Geol. 

Survey, vol. 1, p. 285, 1901.

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. Bureau of Soils, U. S. Dept. Agric., 1903. An analysis of 

Powder River at a different point is also given in this report.

E. Lost River, Klamath County, Oregon. Analyses by A. L. Knisely, Ann. Rept. Irr. 

and Drainage Investigations, U. S. Dept. Agric., 1904, p. 264.

F. Clear Lake, 75 miles north of San Francisco, California. Analysis by T. Price, 

cited in Water-Sup, and Irr. Paper No. 45, U. S. Geol. Survey, p. 33, 1901. 

 G. Feather River at Gridley, California. Analysis reported by E. W. Hilgard, Rept. 

Agric. Exper. Sta., Univ. of California, for 1898-1901.

II. Sacramento River at Sacramento, California. Average of twenty composites, of ten 

dally samples each, taken between January li and August 10, 1906. Analyses by F. W. 

Evans and P. L. McCreary, for the water-resources branch of the United States Geological Survey. Potassium determinations omitted in a few of the later analyses.

I. San Lorenzo River, California. Analysis by A. Seidell, Field Operations Bureau of 

Soils, U. S. Dept. Agric., 1901.

.T. Santa Clara River near Santa Paula, California. Analysis by B. E. Brown, same 

reference as I. An analysis of Sespe Creek is also given.

K. Mission Creek.

L. Cold Spring Creek.

M. Mono Creek, average of three analyses showing different concentrations.

N. Santa Ynez River at Gibraltar, California. Analyses K-N by .T. A. Dodge, WaterSup, and Irr. Paper No. 116, U. S. Geol. Survey, pp. 56-61, 1904. The four streams are 

in the neighborhood of Santa Barbara, California.

C08 .... ........................

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

CI .............................

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

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

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

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

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

A^0a .. ..................... ..

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

Salinity, parts per million .....

pA

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

N08 ......:...... ...............

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

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

A1S08 . ......................

"Clrt f\

Salinity, parts per million ....

A.

4G.16

30.75

.41

'22. 21

4.71

. 6.14

7.78

1.84

100.00 

98

PL

27.30

16.24

7.18

12.34

5.83

10.05

1.26

16.69

| 3. 05

 *

100. 00 

112

B.

32. 65

11.85

4.86

26. 68

1.27

.81

5.81

| 1C. 07

100.00 

31

I.

. 3.09

47.11

16.48

5.01

2.48

24. 59

1.24

100.00 

 4,685

C.

26. 31

13.36

17. 01

16. 20

3.64

15.38

8.10

100. 00 

247

J.

12.55

51.31

5.62

.13.76

6.02

10.74

100. 00 

996

D.

3.17

64. 28

.34

1.69

1.49

28.09

.94

100. 00 

1,481

K.

25. 55

38.45

3.01

17.76

4.62

10.61

100. 00 

444

E.

52, 64

3.37

1.46

14.12

12.06

2.78

.78

10.42

} 2.37

100.00 

220

L.

27.67

37.89

2.10

18.50

6.15

7.69

100.00 

. 621

P.

54.80

3.42

1 79

1 ^ Q3

10.89

4.49

1 92

6 59

} .1,

100.00 

102

M.

18.80

45.68

3.60

14.83

5.41

10.85

.24

.25

.34

100. 00 

1,004

G. '

17. 62

12.72

6 QQ

3

QQ

19.58

OQ f)f\

100. 00 

121

N.

39.10

2.69

18.49

6.29

6.57

.73

100. 00 

821
LAKES AND RIVEES. 71

Although most of these analyses are obviously incomplete, they 

serve a purpose. They illustrate .the distinction between the waters 

of a humid climate and those of a relatively arid region. The Yukon 

is a normal carbonate water; the streams of southern California are 

comparable with the southwestern waters of the preceding section.

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. lied River of the North at Fergus Falls, Minnesota. Analysis by W. A. Noyes, 

Eleventh Ann. Kept. Minnesota Geol. Nat. Hist. Survey, p. 173, 1884.

B. Red River of the North at Fargo, North Dakota. Analysis hy C. F. Sidener for 

the Northern Pacific Railway. Received through M. O. Leighton.

C. Red River of the North at St. Vincent,- Minnesota, near the Canadian boundary. 

Analysis by W. A. Noyes, op. cit., p. 172.

D. Red River of the North below the Assiniboine.

E. 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.

F. Nelson River near its mouth.

G. 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-SO, 

p. 77 C.

co8 ............................

so....... ......................

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

r>(\

NO;, ...........................

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

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

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

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

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

(AlFe)oO.,. ........... .........

Salinity, parts per million. . . . .

A.

32. 52

25.56

.69

30.39

1.97

1.19

..60

7.08

100. 00 

202

B.

56. 15

.87

.99

18. 53

1 3.73

1.75

100. 00 

398

C.

41. 20

15.71

4 89

.19

.28

17.55

8.23

5.64

1.37

.02

4.57

.35

100.00 

284

D,

31.47

22.06

8.78

12.89

7.99

9.67

1.18

5.72

.24

100.00 

551

E.

39.70

16.52

5.58

13.59

7.72

11.08

1.16

4.41

.24

100. 00 

509

F.

16.78

41. 85

4.68

15.91

5.65

6.22

.97

7.30

.64

100. 00 

180

G.

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, Rept. Geol. Survey 

Canada, new series, vol. 9, pp. 39-45 R, 1878. The samples were 

collected at low water.
72 THE DATA OF GEOCHEMISTRY.

Analyses of water from Bow River and tributaries.

H. Bow Eivei- at Calgary.

I. Elbow River at Calgary.

J. Highwood River at High River.

K. Fish Creek at McLeod Trail.

L. Sheep River near Dowdney.

C08 ... ..............................................

SO4 ................ .................................

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

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

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

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

SiO2 ....... ..........................................

K.

48.21

14.69

.94

25.23

6.95

2.42

1.56

100.00

TOO

1.

44.66

18.80

56

94 3Q

6.55

2.77

.42

1.85

100.00 

217

J. '

47.78

13.22

.65

24.48

6.23

3.28

4 36

100.00 IS'4

K.

53.57

5.59

.51

18.82

7.57

7.14

1.34

5.46

100.00

238

L.

45.55

17.13

.57

23 69

C.32

3.92

.43

2.39

100.00 

209

SUMMARY FOR 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. It is evident, of course, that a stream may vary in 

composition from place to place and from time to time; it is plain 

that the samples analyzed were rarely chosen with reference to any 

general discussion' of American waters; and yet, notwithstanding 

these adverse conditions, some regularities appear. 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, tell a different 

story. So also do the waters of New Mexico and Arizona. Here sulphates are in excess of carbonates, and calcium, although sometimes 

dominant, is not always so. In short, where the rainfall is abundant 

and the soil is naturally fertile, carbonate waters are the rule; ill 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 laAvs, 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
LAKES AND RIVERS. ' 73

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 

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 should be that of a carbonate water. So much at least can 

be safely inferred from the data already in hand. To small streams, 

it. must be remembered, these considerations do not ahvays 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.

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 0 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 A7 alue 

relating to the northern part of the continent. The following table 

gives the available data for the Amazon and its tributaries:

Analyses of ^oater from Amazon River md tributaries.

A. The Amazon between the Narrows and c 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 Grundziige der 

Geologic 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. The Tapajos. Analysis by Katzer, loc. cit. Katzer also gives analyses of water 

from Parana-mirim, the Maecuru, the Itapacura-mirim, and several fresh-water lakes or 

lagoons.

"Compt. Rend., Vol. 107, p. 908, 1388. See also .T. Reindl, Natur. Wochenschr., vol. 

20, p. 353, 1905.
74 THE DATA OF GEOCHEMISTRY.

co........... ............................... ....................

804............................................................ ci......... ...................................................

Mg................................ :...........................

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

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

SiO»......... ..................................................

(AlFe)oOj,. ....................................................

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. .T. Kyle, Chem. News, vol. 

38, p. 28, 1878.

B. River Plata near Buenos Ayres." Analysis by R. Schoeller, Ber. Deutsch. chem. 

Gesell., vol. 20, p. 1784, 1887. Water possibly affected by tidal contamination.

C. The Parana 5 miles above its entry into the Plata. Analysis by Kyle, loc. cit.

D. The Uruguay midstream opposite Salto. Analysis by Kyle, loc. cit.

B. The Uruguay above Fray Bentos. Analysis by Schoeller, loc. cit.

F. Rio Negro 6 above Mercedes. Analysis by Schoeller, loc. cit.

G. Colorado River, Argentina. Analysis by Kyle, An. Soc. cient. Argentina, vol. 43, 

p. 19, 1897.'

H. Rio Primero, Argentina. 

I. Rio de los Papagayos, Argentina. Analyses H and 1 by M. Siewert, in R. Napp's 

The Argentine Republic, pp. 242, 244, 1876.

J. Rio Saladillo, Argentina. Analysis by A. Doering.

K. Rio de Arias, Salto, Argentina. Analysis by M. Siewert.

L. Rio de los Reyes, .Tujuy, Argentina. Analysis by M. Siewert. For analyses .T, K, 

and L, see Bol. Acad. nac. cien. Cordoba, vol. 5, p. 440, 1883. = M. Rio Frio, district of Taltal, Chile. Analysis by A. Dietze, cited by L. Darapsky in, 

Das Departement Taltal, p. 93, Berlin, 1900.

N. Rio Copiapo, Chile. Analysis by P. Lem<5tayer, cited by F. J. San Roman in Desierto 

i Cordilleras de Atacama, vol. 3, p. 191, Santiago, 1902.

0 For other data relative to the Plata and the Mercedes, see M. Puiggarl, An. Soc. 

cient. Argentina, vol. 13, p. 49, 1882.

o An analysis of Rio Negro by Will is cited by S. Rivas, An. Soc. cient. Argentina, vol. 

1, p. 326, 1877.

e 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.
LAKES AND RIVERS. 75

PA

SO^.............. ..............

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

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

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

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

No... ........... ................

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

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

AU>3 ...... ....................

Fe00». .........................

Salinity, parts per million .....

COs-...-- .----------. ..........

QA

pi

NO3 - ...........................

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

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

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

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

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

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

Fe208 ..........................

S ..............................

Salinity, parts per million.....

A.

37.45

7.69

12. 59

6.18

3.31

17. 34

3.09

21.32

6.62

'4.41

100. 00 

91

H.

39.47

5.76

G.41

10. 68

3.27

9 09

4. (17

8.58

1.10

5.12

100. CO 

160

B.

11.59

17.97

18.11

6.68

3.71

1.42

24.89

10.82

} 4.81

'

100. 00 

206

I.

.06.

31.81

QO «Q

8.01

.36

26.48

.49

.16

100.00 

9, 185

C.

17.73

20.13

15.92

7.27

2.78

14.96

4.06

20.73

3.21

3.21

100.00 

98

J.

9.94

27.75

21.51

11.29

2.87

16.12

4.41

6.11

100. 00 

1,213

D.

24.23

3.90

.61

5.50

9.82

2.85

3.75

3.12

46.22

100. 00 

40

K.

39.13

13.24

2.77

19. 03

5.20

1.82

5.75

11.57

.89

100. 00 

. 127

E.

21. 59

6.15

5.12

10.01

2.97

5.92

44.32

[ 3.92

100. 00 

66

L.

28.27

18.17

K M U. 00

13. 20

2.53

' 7.19

10.20

12.33

.49

2.09

100. 00 

104

F.

39.10

1.23

4.43

1.95

17.82

1.96

10.24

21.76

} 1.52

100.00 

132

M.

18.06

24.45

8.04

14.93

2.63

15.37

13.22

3.30

100. 00 

186

G.

8.19

30.58

24.51

16. 24

1.46

15.78

3.24

100. 00 

651

N.

6.46

36.50

trace.

6.61

3.52

8.96

.36

35. 39

| 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.

WATERS OF WESTERN EUROPE.

Both Bischof and Roth cite numerous analyses of European river 

and lake waters, but only a feAv of them need be reproduced here. 

Many of the streams are small and affected by local conditions; but 

the predominance of calcium and of the carbonic radicle is clearly 

shown in most cases. For western waters the following examples 

are enough for present purposes:

Analyses of witters from western Europe.

A. The Thames. Average of five analyses cited by J. Roth, Allgem. chem. Geol., vol. 1, 

pp. 456, 457.

B. Lough Neagh, Ireland. Analysis by Hodges, from Roth, loc. cit.

C. The Meuse at Liege, Belgium. Computed from data given by W. Spring and K. Frost, 

Ann. Soc. g6ol. Belg., vol. 11, p. .123, .1884. The Meuse carries past Liege, In solution, 

nearly 1,082,000 metric tons of solids annually. 
THE DATA OP GEOCHEMISTEY.

Analysis by IT. Sainte-CIaire Deville, Ann. chim. phys., 3d

Analysis by -Deville, loc. cit. 

Analysis by Deville, loc. cit. Deville also gives analyses of

D. The Seine at Bercy. 

set'., vol. 23, p. 42, 1848.

E. The Loire near Orleans.

F. The Rhone at Geneva, 

the Doubs and the Garonne.

G.'The Rhone. Average of five analyses by L. Lossier, Arch. sci. phys. nat., 2d seiv, 

vol. 02, p. 220, 1878. Organic matter rejected.

IT. The Arve. Average of six analyses by Lossier, loc. cit.

I. Lac Leman. Analysis by R. Brandenbourg, cited by F. A. Forel ° in Mem. Soc. 

Helvet., vol. 29, 1884.

pn

so4 ..... ....................

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

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

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

NR..........................

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

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

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

Alo03 .. .....................

Fe2 03 ..... ..................

A.

36.89

16.07

5. 70-

1.85

3.26

1.70

4.04

}.- 2.82

100. 00 

270

B.

35.23

10. 68

9.62

17.71

1.31

15.41

3.32

6.72

100. 00 

155

C.

36.48

13.13

3.83

2.86

' 28. 90'

2.68

2.24

.87

.05

6.02

} 2.94

100. 00

D. ,

39.78

8.57

2.95

4.44

on IQ

.63

2.87

.86

9.59

19

.99

100. 00

9^4

E.

30.92

1.72

2.16

1.34

6.93

1 f»4

31.59

5.29

4.10

100.00 

134

F.

27.92

23. 18

.55

3.13

24.89

1.48

' 2.75

.88

13.08

2.14

100. 00 

182

G.

26.68

.71

.31

26.42

3.66

| 3.98

i.55

100. 00 

170

H.

42.37

18.81

1.46

Q9

29 64

3.17

1 2.53

'

1.70

100. 00 

192

I.

33.87

.52

27.81

2.23

2. 53

..25

5.63

] .50

100. 00 

152

0 Forel gives several other analyses of Lac Leman. For the Swiss lakes Taney, Champey, Noir, Lauenen, and Arnsoldingen, see E. Bourcart, Arch. sci. phys. nat., 4th ser., 

vol. 15, p. 467, 1908. J. Thoulet (Bull. Soc. geog., 7th ser., vol. 15, p. 557, 1894) gives 

partial analyses of lakes in the Vosges. For French lakes in general, see A. Delebecque, 

Les lacs- frangais, Paris, 1898. See also A. Delebecque and L. Duparc, Arch. sci. phys. 

nat, 3d. ser., vol. 27, p. 569 ; vol. 28, p. 502, 1892.

In the analyses of the Thames and Lough Neagh the comparatively high figure for chlorine may be partly due to wind-borne salt 

from the sea. The Thames, however, rises in the midland counties 

of England, where the waters issuing from the oolites are relatively 

rich in chlorides.0

RIVERS OF CENTRAL EUROPE..

The following table relates to the Rhine and its tributaries. With 

one exception, the analyses are recalculated from the data as given 

by Roth.''

Analyses of water from the Rhine and tributaries.

A. Lake of Zurich. Analysis by Moldenhauer, 1857. 

B. The Aar at Bern. Analysis by Pagenstecher, 1837. 

C. The Main above Offenbach. Analysis by Merz, 1866. 

D. The Rhine at Basel. Analysis by J. S. F. Pagenstecher, 1837.

E. The Rhine at Strasburg. Analysis by IT. Sainte-Claire Deville, Ann. chim. phys., 3d 

ser., vol. 23, p. 42, 1848.

F. The Rhine at Cologne. Mean of four analyses by H. Vohl, 1870.

a See W. W. Fisher, The Analyst, vol. 29, p. 29, 1904. 

"Allgem. chein. Geol., vol. 1, p. 456.
LAKES AND K1VBES. 77

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

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

C[. .......................................

K03 .. ....................................

vo,.. ....................................

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

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

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

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

SiOs......................................

AlaOs. ....................................

FeaOs.....................................

A.

51.64

7 90

TO

29. 16

5.11

1.60

2.00

2. 06

100.00 

141

B.

'48.60

14.63

.08

30.54

4.71

}

1 Q .18

1.26

100.00 

213

C.

34.39

26.41

4 69

23.56

6.90

1.73

1 90

 ^

100.00

D.

53.05

7 g(;

.57

33.53

2.87 \ " 

1.29

100.00 

166

E.

36.69'

8.38

.52

1.00

25.30

2.17

.66

21.07

1 09

2.51

100.00 

232

F.

47.06

12.61

4.17

.28

07 3(,

5.57

1 2.69

.17

| .09

'

100.00 

178

These analyses are evidently of very unequal- value. The high 

silica found 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." 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. AVith the two exceptions noted, all 

the analyses cited are by Hanamann.

Analyses of water from- tributaries of the Elite.

A. The Molclau above Prague. Mean of three analyses by A. Belolioubek, Sitzungsb. 

K. bohm. Gesell. Wiss., 1876, p. 27. 

B. The Moklau below Kralup. 

C. The Acller near its mouth. 

D. The Iser at its source. 

.13. The Iser near its month.

P. The Eger at its source. Analysis by E. Spaeth. cited by rranamann. 

 G. The Eger above Konigsberg. 

I-I. The Eger near its mouth, at Banschowitz.

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

so.......... ........................ ci. .................................. NO3 .. ......................... ......

PO* .................................

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

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

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

A.

32.86

11.95

10.69

.47

13.52

4.88

10.22

5.19

8.96

1.26

100.00

74

B.

34.52

10.20

10.17

1.76

.36

16.71

4.64

8.40

4.05

4.99

4.20

100.00 

104

C.

46.23

7.44

3.20

1.43

26.73'

2.45

4.29

2.38

5.53

.32

100.00 

195

D.

21.29

6.94

11.08

1.24

8.14

2.19

13.86

5.54

28.39

1 3*}

100.00 

16

E.

47.74

6.55

3.00

.78

28.15

2.'47

3.71

2.01

4.96

.63

100.00 

183

F.

11.68

7.06

23.85

6.79

2.24

11.93

6.71

26.07

3.67

100.00 

17

0.

26.64

19.22

8.16

.50

12.86

3.51

11.66

2.98

12.19

2 OQ

100.00 

80

H.

26.84

27.45

.46

15.42

4 05

10.46

3.50

4.17

1.10

100.00 

176

1 Archiv natur. Landesdurchforschung Bohmen, vol. 9, No. 4, 1894 ; vol. 10, No. 5, 1898.
78 THE DATA OP GEOCHEMISTRY.

To represent the Elbe itself, the following six analyses have been 

selected from Hanamann's table:

Analyses of -water from the Elbe.

I. The.Weisswasser, one of the two chief sources of the Elbe.

J. At Celakowitz, above the mouth of the Jser.

K. At Melnik, above the mouth of the Moldau.

L. At Leitmeritz, above the Eger.

M. At Lobositz, below the Eger.

N. At Tetschen, near the Bohemian frontier.

C08 ... ...................................

SO4.......... ............................ ci........................................

NO3 . .....................................

Mg........ ......................:........

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

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

SiO2 . .....................................

(.\.lF<i)3Oa......... .......................

I.

16.84

12.86

7.61

4.28

8.76

2.19

11.06

2.01

31. 21

3.18

100.00 

13

J.

45.87

8.95

3.27

.90

26.41

3.21

3.93

2.46

4.09

.91

100.00 

221

K.

45.04

8.88

3.56

.94

26.37

2.77

4.02

3.06

4.66

.70

100. 00 

' 205

L.

40.27

10.86

5.00

1.22

22.87

3.24

5.G2

2.79

7 97

.86

100.00 

157

M.

38.41

12.45

. 5.96

1.28

22. 19

3.23

6.35

2.87

6.42

.84

100.00 

111

N.

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.*

a Other data relative to the Elbe and its tributaries are given by ,T. J. 'Breitenlohner, 

Verhandl. K.-k. geol. Reichsanstalt, 1876, p. 172 ; and P. Ullik, Abhandl. K. bohm. Gesell. 

Wiss., 6th ser., vol. 10, 1880.- An analysis of the Moldau at Prague, by P. Stolba, is 

given in Jour. Chem. Soc., vol. 27, p. 971, 1874.- A. Schwager (Geognost. Jahresh., 1891, 

p. 35) gives analyses of water from the Saale, the Eger, and many smaller streams. According to Schwager 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 P. Ehrlich, Mitth. K. Priifungsanstalt fur Wasserversorgung, Heft 9, p. 1, Berlin, 1907. /
LAKES AND EIVEES. 79

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 folloAvs:

Average composition of Bohemian waters, classified according to their sources.

A. From phylllte, five analyses.

B. Prom granite, six analyses.

C. From mica schist, six analyses.

D. From basalt, four analyses.

ID. From the Cretaceous, four analyses.

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

so<............. ....................................

PI

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

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

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

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

Si02 . ................................................ Fc2O:! . ............................................:

. A.

35. 94

6.45

10.15

11.91

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 fi<;

C.

32.14

12. 8G

7.24

12.61

5.08

10. 85

4.22

v 15. 00

100. 00

.IX

46.85

7.94

1. GO

20.07

5.76

0.22

3.20

7.67

.63

100. 00 

343

E.

33. 01

27. 69

2.87

00 10

3

AV

' 2.72

2.87

100. 00 

603

The following table contains analyses of water from the Danube, 

taken at various points:

Analyses of water from the Danube.

A. Above the Naab.

B. Above Regensburg.

C. Above the Hz and Inn.

I). 12 kilometers below Passau. Analyses A to D by A. Schwagei-, Geognost. .Tahresh., 

1808, p. 84. Analyses of the Naab, Regen, I stir, Hz, Erlau, and Inn are also given."

E. At Greifenstein, 20 kilometers above Vienna. Mean of twenty-three analyses by -I. F. 

Wolfbuuer, of samples taken at intervals of sixteen days throughout the year 1878. 

Monatsh. Chemie, vol. 4, p. 417, 1884.

F. At Budapest. Analysis by M. Ballo, Ber. Deutsch. chem. Gesell., vol. 11, p. 441. 

1878. Bicarbonates are here reduced to normal salts.

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

so4 .......... .............................

Cl. ....................................... PO<...... ................................

NO-.... ..................................

N0;i . .....................................

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

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

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

K ........................................ sio2 -..... ......:.........................

TiOn......................................

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

A\tO».......................... ...........

A.

53. 51

7.11

1.20

.23

26.88

6.21

1.47

.96

1.59

.78

.06

100. 00- 

217

B.

51.70

8 54

i QI

nfi

.25

27.40

6.00

1.12

.72

2.42

.42

.06

100. 00 

204

C.

50.16

8.85

1.20

.06

2.14

26.59

6.01

1 34

1.12

2.01

.46

.06

100. 00 

201

D.

48. 29

10. 52

2

f)Ci

trficG

.06

1 19

25.46

6

01

1 84

1.36

2.20

.46

.06

100. 00 

184

E.

50. 10

8

Q1

1.44

26.28

5

QC

1 69

94

3.35

.20

100. 00

F.

ao tn

iq to

1.40

OC fJQ

6 97

Q<*

1.20

100. 00 

151

" For older but incomplete analyses of the Regen, Ilz, and Rachelsee, see H. S. Johnson, Liebig's Annalen, vol. 95, p. 230, 1855.' An analysis of Danube water taken at 

Vienna was made by G. Bischof in 1852.

6 In Schwager's analyses this is given as FeO. I have recalculated his figures to 

Fe»03.
80 THE DATA OF GEOCHEMISTRY.

The regularity shown by these figures is very striking. The Danube water 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 feAv more waters of central Europe are given in the 

next table:

Analyses of water from central Europe.

A. The Gmundener- or Traunsee, which empties through the Traun into the Danube. 

Analysis by R. Godeffroy, .Tahresb. Chemie, 1882, p. 1623. A large amount of organic 

matter is reported, but not included in the following table.

B. Walchensee, Bavaria. Analysis by A. Schwager, Geognost. Jahresh., 1894, p. 91.

C. Lago di Gardai northern Italy. Analysis by Schwager," loc. cit.

D. Balaton- or Plattensee, Hungary. Analysis by L. von llosvay, in Resultate der wissensch. Erforsch. Balatonsees, vol. 1, p. 6, 1898. Reduced from bicarbonate form.

E. The Vistula at Culm. Analysis by G. Bischof, Lehrb. chem. phys, Geol., 2d erf., 

vol. 1, p. 275, 1863.

.

COa. ................ -....-...............-......:....

sot ...... ........................................... ci................ ................................... Ca.... ....................:.............- ...........

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

Na

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

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

A12 03 ...............................................

A.

51. 68

8.99

2.44

27.54

5.21

2.82

.31

} 1.01 '

100. 00 

99

B.

50. 83

11. 62

.58

26.49

7.00

99

.58

1.00

\ 91 I ' J1

100.00

i 91

c.

53.29

4.17

3.13

24.56

2.49

2.01

2

00

1.21

.15

100. 00

10C

D.

38.80

21.47

2.98

8.87

12.81

0.14

3.27

4 48

.82

.36

100. 00 

512

E.

47. 78

9 40

2.70

28.52

4.44

1 H7

.39

A dQ

} .62 '

100.00

17S

0 Schwager also gives analyses of the Starnbergersee and the Eger. In Geognost.

Jahresh. 1897, p. 65, he give.s good analyses of several Bavarian lakes. All are dilute

calcium carbonate waters. For three small lakes near Halle and Eisleben see W. Ule, 

Die Mansfelder Seen, Imiug. Diss., Halle, 1888, and also, by the same author, Der Wiirmsee, Leipzig, 1901. A memoir by ,T. Wolff (Chemische Analyse der wichtigten Fliisse 

und Seen Mecklenburgs, Wiesbaden, 1872) contains analyses of several small rivers and 

lakes. Analyses of water from the Oder are given by Luedecke in Das Wasser des Oderthales, etc., Leipzig, 1907.

The Gmundener water closely resembles that of the Danube. 

Balaton Lake seems to have an exceptional coniposition.

The

RIVERS OF SWEDEN.

For Sweden a single- table of analyses must suffice, reduced from the 

data given by 0. Hofman-Bang.a The month in which the water was 

taken is given for each analysis.

» Bull. Geol. Inst. Upsala, vol. 6, p. 101, 1905.
.LAKES AND EIVEES. 

Analyses of Swedish waters.

81

A. The Byske-elf, .Tuly. 

B. The Klnrelf, April. 

C. The Klarelf, October. 

J">. The Ljusnan, June.

E. The Indulself, .Tune. 

F. The Fyris, April. 

G. The Fyris, October.

CO;,............................

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

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

NO:,..:.........................

P04 . ...........................

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

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

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

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

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

( Al.Fe).,0;... ......:.............

Salinity, parts per million ..'...

A.

50 go

ii.57

fi4

9 90

9.00

7.57

1.96

100. 00 

19.25

B.

39. 44

5.85

5.10

14.95

.51

| 18. 77

13. 09

2.29

100. 00 

27.6

C.

38.68

7.63

2.24

.46

11.67

.51

8.42

3.78

19.17

7.44

100.00 

25.5

».

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

P.

29. 14

24.58

3.15

trace

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

6.19'

1.87

100.00 

178. 1

The remarkably low magnesia and high proportion of alkalies are 

distinctive peculiarities of these waters. The variability of the 

Fyris affords another good example of the fact that little significance 

can be attached to a single analysis of a river water.

RUSSIAN WATERS.*

The following analyses are reduced to standard form from the 

analyses as published by C. Schmidt, of Dorpat:

Analyses of Russian waters.

' A. Lake Onega. M61. chim. phys. St. Petersburg Acad., vol. 1.1, p. 637, 1882.

B. Lake I'eipus. Bull. Acad. St. Petersburg, vol. 24, p. 423, 1878.

C. The Dwina at Archangel. Analysis cited by .T. Roth, Allgera. chera. Geol., vol. 1, 

p. 457.

D. River Om above Omsk. M6m. Acad. St. Petersburg, vol. 20, No 4, 1873.

E. Lake Baikal, Siberia. Same reference as analysis B.

C03 ............................... .................. so*. ................................................

C[...................... ............................

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

P04- ................................................

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

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

Na. .................... ;.... . . K. ..................... ......... . .

Rb................... '............ '

NH<................... . ....... . . .

SiOs ...............................................

Fc2O 3 . .............................................

A.

25.76

5.36

13.97

4.11

.47

8.09

6. 86

13.34

9. 52

.11

.56

10.52

.43

100.00 

49.4

B.

59.57

.62

3.69

.45

.14

25.54

4.15

2.75

2.07

.10

.78

100. 00

C.

26.38

18.95

17.71

.29

12.38

7.58

8.98

1.74

.44

100. 00 

187

:D.

43.73

2.15

12.81

11.24

9! 68

9.64

2.82

6. 51

1.42

100. 00 

447

E.

49.85

6.93

2.44

91

.72

OO A 9

^ K*7

5.85

3 Ad

.08

2

AO

1. 46

100. 00 

69

"For an analysis of the small Lake Ingol. Government of Yeneseisk, Siberia, see S. S, 

Zaleski, Chem. Zeitung, vol. .10, p. 594, 1892,

14399 Bull. 330 OS 6
82 THE DATA OF GEOCHEMISTKY. 

THE NILE.

The water of the Nile has been repeatedly analyzed, with varying 

results. The best data are as f olloAvs: « 

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 Kept. 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 Bng., vol. 60, p. 376, 1880. The total solids contained 10.36 per cent of 

organic matter.

D. The Nile, about two hours journey below Cairo. Analysis by O. Popp, Liebig's 

Annalen, vol. 155, p. 344, 1870. The total solids contained 12.02 per cent of organic 

matter.

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

SO.,.. ..........................................................

Cl. .'.. .........................................................

NO3 . ..........................................................

P04.................... .......................................

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

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

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

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

SiO2 . ........ ....'..............................................

Fe2O3 . .........................................................

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

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

20.10

4.01

3.04

7.97

> 6.47 -^

100. 00

168

D.

36.02

3.93

2.83

CJQ

1 0 01

7 30

13.14

t 9fi

16.?8

2. £5

100. 00 

119

In Letheby's analyses the excess of potassium over sodium is very 

peculiar, 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. &

NOTE. For the other great rivers of Africa chemical analyses are jet to be 

made, and apart from the few Siberian waters I have found, little bearing upon 

Asiatic streams. An analysis of water from Mahanuddy River at Cuttack, 

India, was published by E. Nicholson in Jour. Chem. Soc., vol. 26, p. 229, 1873. 

It is obscurely stated, and I can not attempt to reduce the figures to standard 

form.

ORGANIC MATTER IN WATERS.

Up to this point Ave 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 hy-

"A. Ch61u (in Le Nil, le Soudan., I'figypte, Paris, 1891) gives some very questionable 

analyses of the Blue Nile, the White Nile, and the Nile near Cairo. According to 

Che"lu the river carries past Cairo annually 51.428,500 metric tons of suspended solids 

and 20,772,400 metric tons in solution.

6 On nitrates in the Nile see A, Muntz, Compt. Rend., vol. 107, p. 231, 1888,
LAKES AND ELVERS. 83

' drogen sulpliide. The rain brings also nitric acid and ammonia to 

the soil, and so into the ground water; and various organic substances are invariably found 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 Ihe 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 quantityj in percentages of total 

solids, can be computed in some cases from the original data of the 

analyses already given. A few of the available figures are as follows:

Percentage of organic matter in various slrewms.

Danube _____ ____- 3.25

James _____-_______ 4.14

Manmee ___-____ ____ 4.55

Nile _____________________ 10. 36

Hudson ____ ___________ 11. 42

Rhine ________.________ 11.93

Cuinberliina____________ 12. 08 

Thames______________ 12.10 

Genesee _._____________1 12. 80

Amazon _____________ 15.03

Mohawk ______________ 15.34

Delaware ___:__________ 16.00

Lough- Neagh____________ 16. 40 

Xingu _________________ 20.63 

Tapajos -^_____________ 24.16 

Plata ______._____________ 49. 59

Negro ___.___________ 53.89 

Uruguay _______________ 59. 90

The range of figures is rather Avide, but the highest values represent 

tropical streams. That is, leaving artificial pollution out of account, 

waters flowing through tropical swamps cany the largest proportion 

of organic matter. Lough Neagh, in Ireland, doubtless shows the 

effects of bog water.

The organic matter is derived from the decay of vegetable substances, and by further oxidation may be converted into carbonic acid 

and water. Its chemical constitution is not accurately known, but it 

consists in great part of a vague series of vegetable acids, humic, 

crenic, apocrenic, ulmic, etc., whose precise chemical relations are yet 

to be made out. The salts of these acids are partly soluble and partly 

insoluble in water, and the acids themselves are powerful agents in the 

solution of mineral matter from rocks. According to A. A. Julien,*1 

crenic acid is probably present in all spring, lake, and river waters, 

in which it undergoes oxidation by direct absorption of oxygen from 

the air. Humic acid is said to decompose silicates,6 and by a reaction 

between it and ammonia from rain water, nitrogen from the air, and 

silica in the soil,-a series of silico-azo-humic acids is formed,0 whose

0 Proc. Am. Assoc. Adv. Set., vol. 28, p. 311, 1879. On the organic matter of waters 

in Finland, see 0. Ascban, Zeitschr. prakt. Geol., vol. 15, p. 56, 1907.

"A. Eodzyauko, .Tour. Chem. Soc., vol. 62, pt. 2, p. 1373, 1892. Abstract from Jour. 

Russ. Chem. Soc., vol. 22, p. 208.

c P. Theuard, Cornpt. Rend., vol. 70, p. 1412, 1870.
84 THE DATA OF GEOCHEMISTKY.

alkaline salts are easily soluble- 'In short, the humus acids absorb 

nitrogen from the air to form azo-humic acids, and the latter, in 

presence of alkaline carbonates, are capable of dissolving silica. 

Amorphous silica is presumably the most easily attacked, but even 

quartz may be corroded by this class of organic solvents." To this 

subject I shall recur in a later chapter.

If now we scrutinize carefully the analyses that have been tabulated in the preceding pages, we shall see that an unusually high 

proportion of silica is characteristic of two classes of waters. It 

is very high in the tropical streams, being highest of all in the 

Uruguay River; and in such cases it may be correlated with the 

abundance of organic matter, which serves to hold it in solution. 

No regular and invariable connection between organic matter and 

silica can be traced, however; other factors enter into the problem 

presented; but the general tendency seems to be quite clear. If the 

organic substances in water were invariably the same, a more precise regularity might be indicated; but that, in all probability, is 

not the case. Furthermore, the solubility of any substance is modified 

by the presence of other substances, and no general laws covering 

the entire field have yet been formulated. We can only say that when 

the proportion of organic matter is very high, that of silica is likely 

to be high also.

The converse of this proposition is not true, for the reason that 

another set of conditions operate in bringing about the solution 

of silica. Small streams, near their sources, especially if they rise 

in crystalline rocks, also carry a large relative proportion of silica, 

although its absolute amount may not be large. We see this peculiarity in the headwaters of the Elbe, Eger, and Iser, as shown by 

Hanamann's analyses, and also in the waters of Yellowstorie Lake. 

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 our immediate purposes, best measured by the proportion of chlorine. A good 

example is furnished b}^ the Chicago drainage canal, which empties 

into the Desplaines River and thence passes through the Illinois

0 See C. W. Hayes, Bull. Geol. Soc. America, vol. S, p. 213, 1896.
LAKES AND RIVERS. 85

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." 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 southward.

Total solids and chlorine in Illinois and Mississippi rivers.

Illinois River 

At Morris. . ..........................................................

A.t Ottawa. ..........................................................

At Grafton. .......................... ....

Total 

dissolved 

solids.

Parts per 

million. 

235.3 

269.4

245.2 

230. 3 

234.3 

232. G 

J50. 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. 03 

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 1.00 feet from the Illinois shore, one-fourth the 

distance across, in midstream, three-fourths over, and 100 feet from 

the Missouri shore. The figures represent averages covering periods 

of from nine months to nearly the entire year 1900.

Total solids and chlorine in Mississippi River at Alton, III.

Total 

dissolved 

solids.

Parts per 

million. 

194.1 

182.8 

100. 0 

155.0 

1 54. 2

Chlorine.

Parts per 

million. 

7.7 

7.1 

4.4 

4.1 

3.5

Per cent. 

3.97 

3.87 

2.74 

2.65 

2.27

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 Kankakee at Wilmington 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

« Chemical Survey of the Waters of Illinois, 1807-1002, Univ. Illinois, 1003.
86 THE DATA OF GEOCHEMTSTEY.

higher and the effects of pollution are less conspicuous than in inland 

streams.*

GAINS AND LOSSES IN WATBBS.

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 clay like 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 

may be, relatively to an entire flow, we have no means of estimating. 

Infusoria may remove silica from solution, and .the same substance 

can perhaps be thrown down by the oxidation of the humus acids 

which help to hold it dissolved. By the latter process iron also is 

deposited, for the soluble ferrous crenate, upon oxidation, yields an 

insoluble basic ferric salt, and ultimately ferric hydroxide. -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 main 

divisions still hold. Most waters are either carbonate or sulphate-

°A good summary of the relations between normal and polluted waters in the eastern 

and middle States is given by M. 0. Leighton in Water-Sup, and Trr. Paper No. 79, U. S. 

Geol. Survey, 1903. The subject of normal chlorine is considered and the classical 

" chlorine map " of Massachusetts is reproduced.

See also Sixth Report Rivers Pollution Commission, 1868, on the domestic water supply 

of Great Britain. This report contains abundant data on chlorine in waters.
. LAKES AND RIVERS. 87

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 cr37 stalline 

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 anotherj 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.0 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.

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

« See N. Zelinsky, Jour. Chem. Soc. vol. 66, pt. 2, abstract, p. 200, 1894 ; also M. W. 

Beyerinck, idem, vol. 80, pt. 2, abstract, p. 119; and R. H. Saltet and C. S. Stockvls, 

idem, vol. SO, p. 2, p. 265, 1901.
88 THE DATA OF GEOCHEMISTRY.

adequate; and so the conclusions which have been reached by various 

investigators concerning the quantity of solid matter annually carried by rivers to the sea are without sufficient basis. We have already 

observed 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 Avhole 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 ,a whose figures were cited at the 

beginning of this chapter, has computed, by averaging the analyses 

of nineteen rivers, not only the total amount of saline matter carried 

annually in solution to the sea, but also its composition. His results 

are as follows, together with a reduction to percentages, stated in 

terms of ions:

Saline matter carried annually to the sea l)y nineteen rivers.

TONS PER CUBIC MILE OF RIVER

WATER. 

CaCO3 ____________,_ 326, 710

MgCO3 _________-_________ 112, 870

Ca3P,Os -___ ._____ 2, 913 

CaSO4 ________________ _ 34, 361

Na2 SO4 ___..__________ 31, 805 

K2 SO, ____ - - -__ '20,358

NaNO3 -_____ - _ 26, 800

NaCl _______'_______ 16,657 

LiCl__________________ 2, 462

NH4C1 ___________________ 1, 030

SiO2 ____________________ 74, 577

Fe2O3 _____________ 13, 006

AI.OJ 14,315

Mn-A,_________________ 5, 703

Organic matter_____'.___ 79,020

762, 581

PERCENTAGE COMPOSITION OF INORGANIC MATTER.

CO3 _ ___________________ 41. 33

SO4 __________________ 8. 22

Cl_________________________ 1. 85

NO, __-____________ 2.82

Ca________________________ 20. 46

Mg__________________ 4.65

Na ________________________ 3. 47

K ________ __________ 1.33

SiO, ____________________ 10. 75

R2O3 _ _ .. _________ 4. 76

Minor c-onstituents _______ .36

100.00

Organic rnatter=10.37 per cent of 

total solids.

This estimate, combined with the figures previously given, is 

interesting, for it shows the magnitude of the quantities involved in 

the discussion and emphasizes the preponderance of carbonates in 

river water. But it can not be applied in anything like an exact 

way to determining the extent of chemical denudation over all the. 

globe. It is based almost entirely 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 

practically unobtainable, and hence we must regard Murray's computation as only a very 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.

Scottish Geog. Mag., vol. 3, p. 65, 1887.
LAKES AND RIVERS. 89

The problem, however, can be attacked locally, with reference to 

special areas. T. Mellard. Reade," for instance, in a well-knowninvestigation, Jias 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 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. '

The figures given in the preceding pages, with reference to American rivers, lead to rather lower estimates. The data may be tabulated as follows, with metric instead of British tons. 6

Saline matter carried annually to the sea, by four American

River. Area 

drained.

Sq. miles. 

286,900 

9,650 

1,259,000 

225,000

1,780,550

Saline matter.

Total.

Tons. 

29,278,000 

771,000 

98,369,000 

13, 416, 400

143,834,400

Per 

square 

mile.

Tons. 

102 

80 

78 

60

i79.6

" Average.

The variation, in tons per square mile, between these figures is 

quite important. The Colorado drains an arid region, and m ach 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 ivgure 

for the chemical erosion. The mean value, in round numbers 80 

metric tons per square mile, is probably not far from the truth, and 

presumably is fairly correct for the entire area of the United States, 

exclusive of the Great Basin. This figure, however, refers only to 

inorganic matter. If organic impurities are to be included, it should 

be« increased by perhaps 10 per cent, that is, to 88 metric tons per 

square mile.0

°Fro<:. Liverpool Geol. Soc., vol. 3, p. 211, 1876-77. Reprinted under the title " Chemical Denudation in Relation to Geological Time." 

.'' 2,205 pounds as against 2,240.

c For other estimates of the amount of material carried by various rivers, see Geikie, 

Text-book of Geology, 4th ed., vol. 1, p. 489, 1903. The Thames, for example, carries 

In solution past Kingston 548,230 tons of fixed inorganic matter in a year. See also 

the thesis of A. F. White on the waters of Rockbridge County, Virginia (Washington and 

Lee University, 190G). This thesis deals with North River, a tributary of the James. 

In Reade's Evolution of Earth Structure still other data are given.
90 THE DATA OF GEOCHEMISTRY.

All of these calculations of course are subject to revision, and even 

the best of them may be greatly modified. At this point a few words 

of caution may be useful. Suppose we knew exactly how much .dissolved matter a certain river annually discharged into the sea. In 

order to determine its geological significance, we should have to 

allow for several factors of other than geological origin. Part of 

the chlorine came in rainfall from the .atmosphere and part of it from 

pollution by towns. The carbonic acid, also, would be partly of 

direct atmospheric origin, and only a portion would represent the 

actual solution of-limestones. For the chlorine and its equivalent 

sodium corrections can probably be made; a but discrimination in 

the case of carbonic acid is more difficult. We must also remember 

that a river drops some of its burden during its course; so that the 

amount of saline matter delivered to the ocean is not an exact measure of the rock decomposition which its waters have effected.

" Reade, in his calculations relative to England and Wales, takes these disturbing 

factors into account. Spring and Prost, in their work on the Meuse, and Ullik, in his 

study of the Elbe, have attempted to measure the amount of human contamination. 

This factor, obviously, must be very variable. In rivers like the Yukon or the Colorado 

it is negligible; in the Misissippi or the Hudson it is doubtless large.
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."

In his great memoir on the chemical composition of sea water, G. 

Forchhammer b 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 n'ow.

Iodine. Chiefly found in the ashes of seaweeds. According to E. 

Sonstadt,0 it is present in sea water in the form of an iodate. A. 

Gautier,d 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 Gautief 

is 2.38 milligrams to the liter. J. Koettstorfer," in an earlier investigation, found much smaller quantities.

Fluorine. Found directly, and also in the boiler scale of oceanic 

steamers. A. Carnot's determinations f show that the water of the 

Atlantic contains 0.822 gram of fluorine to the cubic meters P. 

Carles ft 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.

"For the volume of the ocean and of its contained salts, see ante, pp. 22-23.

"Phil. Trans., voi: 155, pp. 203-262, 1865. See also T. Roth, Allgem. chem. Geol., vol. 

1, p. 400, 1879; and W. Dittmar, Kept. Challenger ISxped., Physics and chemistry, vol. 1, 

pp. 1-251, 1884.

c Chem. News, vol. 74, p. 316, 1896.

d Compt. Rend., vol. 128, p. 1069, 1899 ; vol. 129, p. 9, 1899.

o Zeitschr. anal. Chemie, vol. 17, p. 305, 1878.

'Ann. mines, 9th'ser., vol. 10, p. 175, 1896.

o See also earlier determinations by G. Forchhammer and G. Wilson, Edinburgh New 

Phil. Jour., vol. 48, p. 345, 1850.

* Compt. Rend., vol. 144, pp. 437, 1240, 1907.

91
92 THE DATA OF GEOCHEMISTKY.

A. Audoynaud,(t in water from the coast of France, found 0.16 to 1.22 

milligrams of NH, per liter. L. Dieulafait,6 in waters from the Red 

Sea and the coast of Asia, reports quantities from 0.136.to 0.340 

milligram. T. Schloesing c found a still larger amount, namely, 0.4 

milligram. According to J. Murray and R. Irvine,d 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. 6

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 f found its quantity 

to range from 0.01 to 0.08 milligram per liter.

Silicon. According to J. Murray and R. Irvine,4' 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.

Boron. Present in sea water and also in the ashes of marine 

plants. J. A. Veatch,71 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.* 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.

Caesium. Also found by Sonstadt.

Barium and strontium.- Can be detected by ordinary methods. 

Also found in the ashes of seaweeds and in boiler scale.

Aluminum and iron. Easily detected by direct methods.

0 Compt. Rend., vol. 81, p. 619, 1875.

6 Ann. chim. phys., 5th ser., vol. 14, p. 380, 1878. Dienlafait mentions earlier work 

by Marchand and Boussingault.

c Contributions & 1'e'tude de la chimie agricole, in Fremy's Encyclopedic chimique, 1888.

d Proc. Roy. Soc. Edinburgh, vol. 17, p. 89, 1889.

o Monatsh. Chemie, vol. 14, p. 675, 1893 ; vol. 15, p. 596, 1894 ; vol. 16, p. 591, 1895 ; 

vol. 20, p. 1, 1899.

f Compt. Rend., vol. 137, pp. 232, 374, 1903.

o Proc. Roy. Soc. Edinburgh, vol. 18, p. 229, 1891.

71 Proc. California Acad. Sci., vol. 2, p. 7, 1859.

1 Ann. chim. phys., 5th ser., vol. 17, p. 377, 1879. See also Thorpe and Morton's analysis of water from the Irish Sea, 1871, cited on pp. 94, 95.
THE OCEAN. 93

Manganese. Easily detected. Noted by Forchhammer and also 

by Dieulafait." Concretions of manganese oxide are abundant over 

portions of the sea bottom. Reported by E. Maumene 6 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. c Also in the ashes of seaweeds and in certain corals.

'Zinc. Reported in sea Avater by Dieulafait.** 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,0 silver is present in sea water to the extent of 1 to 2 grains

per ton.

Gold. The fact that sea water contains gold was first established 

by E. Sonstadt f in 1872. Its presence has since been repeatedly 

verified. In 1892 C. A. Minister ^ examined Avater 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 h found the gold in Australian waters to range 

from 0.5 to 1.0 grain per ton. At either rate, gold is present in the 

ocean' in thousands of millions of tons. Liversidge * also detected 

gold in kelp, rock salt, and a number of saline minerals, such as 

sylvine, kainite, carnallite, and Chilean niter. In one sample of kelp 

he found 22 grains of gold per ton, and in a bittern, 5.08 grains. 

J. R. Don i 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 fc found, also per metric ton, 11.1 milligrams 

of gold and 169.5 of silver.

"Compt. Rend., vol. 9G, p. 71.8, 1883. 

 "Idem, vol. 98, p. 1417, 1884.

c Ann. chim. phys.., 5th ser., vol. 18, p. 359, 1879.

 'Idem, vol. 21, p. 2G6, 1880.

° Proc. Roy. Soc. New South Wales, vol. 29, pp. 335, 350, 1895.

f Chem. News, vol. 25, pp. 196, 231, 241, 1872; vol. 74, p. 31.0, 1.896 ; Am. Chemist:, 

vol. 3, p. 206, 1872.

o Jour. Soc. Chem. Ind., vol. 11, p. 351, 1892. From Norsk Tekn. Tidsskr. 

ft Proc. Roy. Soc. New South Wales, vol. 29, pp. 335, 350, 1895.

* Jour. Chem. Soc., vol. 71, p. .298, 1897. 

1 Trans. Am. Inst. Min. Eng., vol. 27, p. 6.15, 1897.

' 'Idem, vol. 31, p. 806, 1901. P. DeWilde (Arch. sci. phys. nut, 4th ser., vol. 19, p. 

559, 1905) and A. Wiesler (Zeitschr. angew. Chemie, 1906, p. 1.795) have published good 

summaries relative to the detection of gold in sea water, and also discussed the possihility of its economic recovery.
94 THE DATA OF GEOCHEMISTRY.

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 anatyses, 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:

Analyses of oceanic salts.

A. Mean of seventy-seven analyses of ocean water from many localities, collected by 

the Challenger expedition. W. Dittmar, analyst. Challenger Kept., Physics and chemistry, vol. 1, p. 203, 1884. Salinity 3.301 to 3.737 per cent.

B. Atlantic water," mean of twenty-two samples collected on a voyage from the Cape 

of Good Hope to England. C. J. S. Makin, Chem. News, vol. 77, pp. 155, 171, 1898. 

Salinity, average, 3.631 per cent.

C. The Atlantic near Dieppe. Analysis by T. Schloesing, Compt. Rend., vol. 142, p. 

320, 1906. Salinity, 32.420 grams per liter.

D. The Irish Sea. Analysis by T. E. Thorpe and E. H. Mortou, Liebig's Annalen, 

vol. 158, p. 122, 1871. The small amounts of Fe20;i, NH3 , and NoO5 are here added 

together. A trace of lithium was also reported.-

E. The Baltic Sea between Oeland and Gothland. Analysis by C. Schmidt, Bull. 

Acad. St. Petersburg, vol. 24, p. 231, 1878. In all of Schmidt's analyses the bicarbonates 

given by him have been here reduced to normal salts. The quantities of Fe, P04, and SiO^ 

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. Sot', 

dent. Argentina, VOl. 54, p. 62, 1902. Salinity, 3.365 per cent. Another pair of analyses 

is given of water taken at the mouth of Rio Negro;

G. The north Atlantic between Norway, the Faroe Islands, and Iceland, and northward 

to Spitzbergen. Mean of fifty-one incomplete analyses by L. Schmelck, Den Norske Nordhavs-Expcdition, pt. 9, p. 1, 1882. Soda and carbonic acid estimated by calculation, not 

directly determined. Salinity, 3.37 to 3.56 per cent.

H. The White Sea: Average of three analyses by C. Schmidt. Bull. Acad. St. Petersburg, vol. 24, p. 231, 1878. Salinity, 2.598 to 2.968 per cent.

I. The Arctic Ocean between the White Sea and Nova Zemblfj.. Mean of two analyses 

by Schmidt, loc. cit.

J. The Siberian Ocean. Water collected by the Vega expedition. Mean of four analyses 

by Forsberg, Vega Exped. Kept., vol. 2, p. 376, 1883. Salinity, 1.378 to 3.457 per cent.

K. The Mediterranean near Carthage. Analysis by T. Schloesing, Compt. Rend., vol. 

142, p. 320, 1906. Salinity, 38.9744 grams per liter.

L. The Mediterranean, midsea, between Bizerta .and Marseilles. Salinity, 38.789 

grams per liter. Analysis by Schloesing, loc. cit.

M. The eastern Mediterranean, 6 waters collected during the voyages of the Austrian 

steamer Pola. Analyst, K. Natterer, Monatsh. Chemie, vol. 13, pp. 873, 897, 1892; vol.

0 Other analyses of Atlantic water, taken off the coast of Brazil, with analyses of " 

water from the mouths of the Amazon, are given by F. Katzer, in Sitzungsb. K. bohm. 

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, p. 2888, 1885.

''An analysis of water from the Ionian Sea., by F. Wibel. is printed in Ber. Deutsch. 

chem. Gesell., vol. 6, p. 184, 1873. One by A. Vierthaler (Sitzungsb. Akad. Wien, vol. 

56. p. 479, 1867), of Adriatic water taken near Spalato, shows abnormally low sodium 

and high calcium, presumably due to admixtures of water from the land.
THE OCEAN. 95

14, p. 624, 1893; vol. 15, p. 530, 1894. Three hundred samples of water were examined, 

some only for gases. The figures given here are the average from forty-two analyses 

which were fairly complete. Salinity, 3,836 to 4.115 per cent.

N. The Sea of Marmora. Natterer, Monatsh. Chemie, vol. 16, p. 405, 1895; 44 partial 

analyses. Natterer gives the figures here utilized as averages of varying numbers of 

determinations. Mg, Na, and'K not determined. Salinity, 2.310 to 4.061 per cent.

0. The Black Sea. Average of six analyses by S. Kolotoff, Jour. Russ. Phys. Chem. 

Soc., vol. 24, p. 82, 1893. Salinity, 1.826 to 2.223 per cent.

P. The Suez Canal" at Ismailia. Analysis by C. Schmidt, Bull. Acad. St. Petersburg, 

vol. 24, p. 231, 1878. Salinity, 5.103 per cent.

Q. The Red Sea near the middle. Analysis by Schmidt/ loc. cit. Salinity, 3.976 per 

cent.

. K. The Red Sea. Average of four analyses by Natterer, Monatsh. Chemie, vol. 20, 

p. 1, 1.899 ; vol. 21, p. 1037, 1900. 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.

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

Br ..........................

so4 .. .......................

PA

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

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

Kb..........................

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

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

Fe, SiO.,, P04 . . . . ...........

Fe, NH~4 , NO;,....-......-.'..

Alo03 , Fe.08 ,SiO.............

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

Br.... .......................

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

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

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

Rb..........................

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

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

A.

55.292

7. 092

.207

30. 593

1.106

1.197

3.725

100. 000

J.

} 55. 45

7 97

30. 41

1.17

1.18

100. 00

. B.

55. 185

.179

7.914

.213

30.200

1.109

1. 244

3.896

100. 000

K.

55.53

.18

7.74

.19

30.37

1.09

1.26

8 fid

100. 00

C.

55.04

.19

7.80

.18

30.71

1.06

1.27

3.09

100. 00

L.

55.11

.19

7.89

.20

on /M

1.09

1.23

3.05

inn on

D.

55.21

.19

7.69

.09

30.82

1.16

1.21

3.01

.02

100.00

M.

55.30

.16

7.72

. .19

30.51

1.12

1.19

3.81

inn on

E.

55.01

.13

s.oo

.14

30. 47

.90

.04

1.07

3.53

.05

100.00

N.

55.45

.17

7.67

.28

1.22

F.

54. G2

8.01

.27

30.20

2.10

1.30

3.30

.08

100. 00

0.

55.12

.18

7.47

.46

30.46

1.10

1.41

3.74

100. 00

G.

1 55.46

7.59

.30

30.53

1.12

1.21

3.79

100. 00

P.

55. 59

.14

7.67

.01

31.21

.04

.03

1.05

3.64

.02

inn nn

H.

55.22

7.88

.10

30. 05

.93

.04

1.21

3.75

.08

100. 00

Q.

55. 60

.13

7.05

.02

30.81

.97

.04

.89

3.87

.02

100 00

1.

55.30

7.78

.07

30.85

9Q

.04

1.10

3.09

.08

100. 00

R.

55.90

.18

7.49

.13

in 11

1.00

1.22

3.05

100 00

" For other data on the Suez Canal, see L. Durand-Claye, Ann. chim. phys., 5th ser., 

vol. 3, p. 188. 1874. Very high salinities were noted. For a recent, incomplete analysis 

of Red Sea water, see J. B: -Coppock, Chem. News, vol. 96, p. 212, 1907.

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, wi'th their very low salinit}', 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.
96 THE DATA OF GEOCHEMISTRY.

For the composition of ocean salts in general, Dittmar's average 

should be taken as the standard of comparison. It represents the 

largest number of complete analyses and the greatest refinement of 

methods; the samples examined covered the widest geographic range 

and were drawn from various depths of water. Some were surface 

specimens, others from the bottom of the sea, and still others from 

points between, and all the results lead to the same general conclusion 

of nearly uniform composition, in spite of variable salinity. The individual analyses vary but little from the mean. The salinity is 

shown to be a function of temperature, pressure, and density; and the 

last factor is represented by J. Y. Buchanan's elaborate determinations, which appear in the same volume with Dittmar's analyses.0 

In general, according to the summary given in the "Narrative " of 

the Challenger expedition,1 the density and therefore the salinity of 

ocean water diminishes from the surface to a depth of 800 to 1 2 000 

fathoms, and then increases to the bottom. Toward both poles there 

are areas of concentration due to the formation of ice, a process which 

removes water from liquid circulation, leaving a large part of its salts 

behind. Freezing, as 0. Pettersson c 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 d 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

.97

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.

" Nattercr also, in the memoirs already cited, discusses the relations between density 

and salinity. So, too, does H. Tornoe in Den Norsk.e Nordhavs-Expedition, 1880. See 

also memoirs by A. Bouquet de la Grye, Ann. chim. phys., 5th ser., vol. 25, p. 433, 1882 ; 

and A. Chevallier, Cornpt. Rend., vol. 140, p. 902, 1905. On this theme there is an extensive literature, but physical problems can be only incidentally considered in the present 

memoir.

" Vol. 2; pp. 948-1003, 1882.

e Vega Exped. Kept., vol. 2, pp. 349-380, 1883.

<< See O. Pettersson, op. cit., p. 376, 1883.
THE OCEAN. 97

In" one sense the salinity of sea water is a function of climate, at 

least so far as surface waters are concerned. Where the rainfall is 

slight and the evaporation rapid, concentration occurs; where the 

atmosphere is saturated with moisture the reverse is true. The Red 

Sea shows the maximum effect of evaporation and the highest 

salinity; the Mediterranean is next in order. West of the Nile no 

large rivers enter the Mediterranean; the evaporation along the African shore is very great, and the salinity is therefore excessive. Furthermore, rainfall serves to dilute the superficial layers of the ocean, 

and the same effect is produced by the influx of streams. The Black 

Sea, for instance, is diluted by the Danube, and its average salinity 

barely exceeds 2 per cent. When a river enters the ocean its waters 

tend to flow upon the surface, and its influence may be detected at 

great distances, sometimes hundreds of miles from land. Salinity, 

in short, is the product of many agencies, and the commingling of 

waters is never quite complete. In view of conditions like these 

the nearly uniform composition of sea salts is all the more striking.

It is commonly assumed that the salts, of the ocean are derived 

from the decomposition of rocks by flowing and percolating waters, 

which finally deposit their burden in the great general reservoir. 

That this opinion is in a very large measure correct is unquestionable; whether it is wholly true, without qualification, is another 

matter. We have already seen, in the preceding chapter, that an 

enormous mass of soluble salts is annually discharged by rivers into 

the sea, but its composition is very different from that of the saline 

substances which we are now considering. In the one class of waters 

carbonates and calcium prevail, in the other we find mainly chlorides and sodium. In their relative proportion of sulphates the 

fresh and salt waters diverge less widely. 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" 

estimate that the discharge of rivers would require 680,000 years to 

make up the total oceanic amount. 6

Troc. Roy. Soc. Edinburgh, vol. 17, pp. .1.00-101, 1889.

"R. A. Daly (Am. Jour. Sci., 4th ser., vol. 23, p. 93, 1907) has argued that the pre-' 

Cambrian ocean was Hmeless, or nearly so. For a statistical paper on the mineral 

matter In the sea, see R. D. Salisbury, Jour. Geol., vol. 13, p. 469, 1905. See also A. C. 

Lane, Jour. Geol., vol. 14, p. 221, 1906, and A. B. Macallum, Trans. Canadian Tnst, vol. 

7, p. 35, 1903.

14399 Bull. 330 08 7
98 THE DATA OF GEOCHEMISTRY.

Practically, then, the composition of the ocean is very nearly constant, and has been so for long periods'of time. We can not, by means 

of analysis, measure the changes in it, but we can observe some of 

them in operation, and see whither they tend. They are due either 

to gains or losses of material, and both conditions have been noted 

in the preceding pages. The gains from rivers and from rainfall are 

obvious; the losses by precipitation we shall examine presently. 

Some salts, as we observed in studying the atmosphere, are lifted 

from the ocean to fall again, partly upon the land, in rain. Much of 

this material returns into the sea, but we can -not assume that all of it 

is regained. This loss, however, is trifling, and needs no further consideration here. Streams bring more chlorine and more sodium into 

the ocean than it loses through the mechanical action of the air. For 

these constituents a small net gain may safely be taken for granted. 

As for the changes in composition produced in sea water by freezing, 

they are local and transitory in character. When the ice melts', its 

saline contents are restored to oceanic circulation, although not always 

at the point from which they were withdrawn. To the slight change 

thus produced in Arctic waters reference has already been made.

CARBONATES JN 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 riot quite insoluble in 

water. Upon this point many observations have been made. According to T. Schloesing,0 whose data appear to be trustworthy, a 

liter of water at 16° can dissolve 0.0131 gram of CaCO,. With respect to sea water,, however, the different varieties of the carbonate 

behave differently. This has been shown by R. Irvine and G. Young,& 

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.

"Compt. Rend., vol. 74, p. 1552, 1872.

''Proc. Roy. Soc. Edinburgh, vol. 15, p. 316, 1888. For other data on the solubility 

,of calcium carbonate in sea water, see W. S. Anderson, Proc. Roy. Soc. Edinburgh, vol. 

.16, p. 318, 1889 ; and J. Thoulet, Compt. Rend., vol. 110, p. 652, 1890.
THE OCEAN. 99

Some re-sollition, 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.0 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, CaH2C2 OG is then formed. Of this salt, as shown 

by F. P. Treadwell and M. Renter,6 a liter of pure water at 15° can 

dissolve 0.3850 gram, a quantity which may be considerably increased 

by an excess of carbon dioxide in the water. In sea water this solubility is modified by the presence of other compounds. E. Cohen and 

M. Raken,0' experimenting with an artificial sea water, found that at 

1J5° it was saturated by 55.6 milligrams of fixed C02 per liter, equivalent to 0.1264 gram of CaC03 . According to G. Linck,d 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 CO, 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. 0 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 B. Willis f has recorded a 

similar reaction which 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 .points Pteropod remains were never found on the ocean floor

a Proc. Roy. Soc. Edinburgh, vol. 17, p. 79, 1889.

6 Zeitschr. anorg. Chemie, vol. 17, p. 170, 1898.

c Proc. Sec. Sci., Amsterdam Acad., vol. 3, p. 63, 1901.

d Neues .Talirb., Bell. Bd. 16, p. 503, 1903.

" W. Dittmnr, Challenger Rept, Physics and chemistry, vol. .1, p. 211, 1884.

'Jour. Geol., vol. 1, pp. 500-520, 1893.

» See summary in vol. 2 of the Narrative, pp. 948 et seq., 1882.
100 . THE DATA OF GEOCHEMISTRY.

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 

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,a 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 geological 

periods now supplies material to streams, thus returning to the ocean 

carbonates which were once withdrawn from it. 1

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.0 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.

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 else0 See J. Murray and R. Irvine, Froc. Roy. Soc. Edinburgh, vol. 17, p. 79, 1889.

6 On the circulation of calcium carbonate, and its relation to the age of the earth, 

see E. Dubois, Froc. Sec. Sci., Amsterdam Acad., vol. 3, pp. 43, 116, 1901.

0 The insolubility of silica in sea water is great, hut not absolute. J. Murray and A. F. 

Uei^ard (Challenger Rept., Deep-sea deposits, p. 288, 1891) find that some silica can be 

dissolved out from dietonmceous ooze.
THE OCEAN. 101

where, 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." The larger deposits may be classified as follows:

Deposits on the ocean floor.

Name.

Kadiolarian ooze ................... ..... ... ................

Diatom 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 var-iowt depths.

Under 500 fathoms_______ 80. 04. 

500 to 1,000 fathoms ._____ 66. 86 

.1,000 to 1,500 fathoms.,.____ 70. 87 

1,500 to 2,000 fathoius______ 69. 5f>

2,000 to"2,500 fathoms_________ 4.6.73

2,500 to 3,000 fathoms______ 17.86 

3,OQO to 3,500 fa thorns __..__.__ .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 vieAv, 

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

"Sec also .T. .Murray, Oeog. .Tour., vol. 19,-p. 691, 1902; on material collected in 1901 

by S. S. Britannia..
102 THE DATA OF GEOCHEMISTRY.

long distances by currents of air. Other fragments represent submarine volcanoes. Some of the fragments studied by Murray and 

Renard were quite fresh, others were largely decomposed; and in a 

number of them zeolites had been formed by subaqueous alteration. 

Crystals of phillipsite were repeatedly identified. The color of the 

clay is due to ferric oxide or hydroxide, which is easily removable by 

means of strong acids. In all essential respects the clay resembles 

the residues formed by the decay of igneous rocks. Its composition, 

as shown by many analyses, is extremely variable.

That sea water will attack and dissolve silicates is well known, 

although its efficiency is less than that of fresh water. On this subject the experiments of J. Thoulet'1 have been often quoted, and 

A. Johnstone l has sho^wn that even so refractory a mineral as 

talc is slowly but perceptibly soluble. The process of change is of 

course almost inconceivably slow; but in the quiet depths of the 

ocean it has doubtless been going on throughout all geological time. 

It began when the first volcanic 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. 0 Even in shallow waters, as in Loch 

Fyne in Scotland, these nodules have been found/' 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 G regards the manganese as derived, like the red 

clay, from the subaqueous decomposition of volcanic debris. C. W.

" Compt. Rend., vol. 108, p. 753, 1889. See also recent work by .T. Toly, in Compt. 

Rend. VIII: Cong. geol. internal., p. 774, 1900.

*Proc. Roy. Soc. Edinburgh, vol. 16, p. 172, 1889.

'' For full description see Challenger Rept., Deep-sea deposits, pp. 341-378, 1891. See 

also .T. Murray and R. Irvine, Trans. Roy. Soc. Edinburgh, vol. 37, p. 721, 1895.

"J. Y. Buchanan, Proc. Roy. Soc. Edinburgh, vol. IS, p. 19, 1890.

« Proc. Roy. Soc. Edinburgh, vol. 9, p. 255, 1876.
THE OCEAN. . 103

Glimbel ° attributes the nodules to submarine springs holding manganese in solution, which is precipitated on contact with sea water. 

Buchanan b 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,0 who showed that 

manganese sulphide was decomposed by sea water, the manganese 

redissolving as bicarbonate. J. B. Boussingault (l holds that the manganese was derived from carbonates carried in solution by oceanic 

waters, and a similar explanation has been offered by L. Dieulafait.6 

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 easily be derived from the alteration of 

rock fragments, as it is by weathering on land; it goes into solution 

as carbonate, is oxidized by the dissolved oxygen of the sea water, 

and is precipitated near its point of derivation around any nuclei 

which happen to be at hand. The nodules occur in close association 

with altered volcanic materials, and most abundantly in connection 

with the red clay of similar origin; furthermore, their impurities are 

of the kind which the suggested mode of formation would lead us to 

expect. In composition the nodules vary widely, ranging from 4.16 

to 63.23 per cent of manganese oxide. The analysis by J. Gibson f 

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 .</________.____________ 2.44

Insoluble residue ___________________________ 17.93 

Portion soluble in HC1_______________..______ 49. 97

99.99

" See abstract in Neues .Talirb., 1878, p. 869. 

»Proc. Roy. Soc. Edinburgh, vol. 18, p. 17, 1890. 

r- Idem, vol. 18, p. 54, 1890.

'' Ann. chlrn. phys., 5th ser., vol. 27, p. 289, 1882. '. 

« Compt. Rend., vol. 96, p. 718, 1883. 

' Challenger Rept., Deep-sea deposits, pp. 417-423, 1891.

' Saline matter unavoidably inclosed in the nodules. Gibson gives 'its composition in 

detail.
104 THE DATA OF GEOCHEMISTRY.

The insoluble and soluble portions, recalculated separately, are 

represented in the subjoined statement:

Analysis of manganese nodule.

SiO2 ............ ...........................;....................................

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

A12O3 . ..........................................................................

Fe2 03 ...........................................................................

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

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

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

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

MnO ......:....................................................................

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

CoO...... ......................................................................

ZnO.................... ........................................................

CuO.... ........................................................................

PbO.. ..........................................................................

TJ2 0 ...........................................................................:

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

K2 0..... .......................................................................

P2 05 .. ......................................................................:...

V2 0S .. ..........................................................................

MoO^. ..........................................................................

S03 .. ............................................................................

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

Portion 

soluble in 

IIC1.

6.34

20.97

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

12.93

4.79

1.45

.11

.67

3.62

.95

.11

99. 93

If we include in this analysis the water of the original material we 

see that it represents a mixture of manganese, iron, and aluminum 

hydroxides, soluble in hydrochloric acid, with an insoluble residue of 

silicates. The specimen came from a depth of 2,375 fathoms.

The phosphatic concretions found on the ocean floor offer a simpler problem for solution. As Murray and Renard a 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 Avhich 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.

" Challenger Kept., Deep-sea deposits, pp. 397-400, 1891. On the phosphatic nodules 

of the Agulhas Bank, see L. W. Collet. Proc. Roy. Soc. Edinburgh, vol. 25, p. 862, 1905 ; 

and L. Cayeux, Bull. Soc. g<5ol., 4th ser., vol. 5, p. 750, 1900.
THE OCEAN. 

Analyses of phosphatic concretions from sea bottom.

105

PiO»..................... ...........................................................

CO,. ................................................................................

SOj...................... ................... ....... ..... .....

SiO«................. ....................... ..... ..... .......................

CaO ..........................:............. ....... . .............................

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

FejOs- ..............................................................................

AhOg.... ...........................................................................

Insoluble residue .................... . .............................................

A.

19.96

12.05

1 37

1.36

39. 41

.67

2.54

1.19

17. 34

95.89

B.

23.54

10.64

1 30

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.

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

AlA).... ...............................................................................

Fes03 . ...................................................................................

OaO ...................................................................:................

MgO.....................................................:..............................

A.

77.43

12.40

7.91

1.07

1.02

99.83

B.

76.58

13. 85

7.93

1.27

1 Is

100. 81

The concretions, then, consist mainly of calcium phosphate and carbonate, mixed with sand and clay.

The last of the oceanic deposits which we need to consider in this 

connection is glauconite, a hydrated silicate of potassium and ferric 

iron. It is widely disseminated upon the sea bottom, but most abundantly in comparatively shallow waters and near the mud line surrounding continental shores that is. it is formed "just beyond the 

limits of wave and current action, or, in other words, Avhere the fine 

muddy particles commence to make up a considerable portion of the 

deposits." a . 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 Avhich, 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

" Murray and Renard, Challenger Kept., Deep-sea deposits, p. 383, 1891.
106 THE DATA OF GEOCHEMISTRY.

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 hew substances by chemical 

change. Their study is complex and many of the conclusions drawn 

are uncertain, but the subject is one of great importance and interest 

and deserves more attention than it can be given here. For present 

needs this bare outline must suffice." *

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 compounds occur in fresh and salt waters in nearly the same relative 

proportions, reckoned in percentages of anhydrous residue, as may be 

seen by comparing Murray's river average with Dittmar's mean 

composition of ocean salts. In the river salts SO4 forms 8.22 per 

cent; in the s'ea 7.69. The figure for river water is not precise 

enough for any close comparison to be made, but the approximate 

equivalency is clear. From this relation we may infer that sulphates 

tend to accumulate in the ocean without great losses, although we 

have seen that under certain conditions they are reduced to sulphides 

by organic matter, a change which is counterbalanced by reoxidation under other circumstances. So far as the open sea is concerned, 

the precipitation of sulphates seems to be a matter of small magnitude, although they are found in all the clays and oozes in trivial 

proportions. In closed basins or lagoons the case is different, but 

examples of that kind are not in question now.

With potassium other conditions hold, and the two classes of 

waters are not at all alike. In river waters, on an average, the proportion of potassium is about one-third that of the sodium; 6 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?

a E. .T. .Tones (Jour. Asiatic Soc. Bengal, vol. 56, pt. 2, p. 209, 1887) 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.

b 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.
THE OCEAN. 10*7

The answer to this question is simple. Hydrous silicates of aluminum, the clays, are able to take up considerable proportions of potassium and to remove its salts from solutions. According to J. M. 

van Bemmelen*1 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 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.6 In glauconite 

and phillipsite deposits potassium always predominates. L. 

Schmelck,6' in his analyses of clays from the northern Atlantic, records 

no alkalies, but K. Natterer,'* in sediments from the eastern Mediterrean and the Red Sea, found small quantities of potash and soda, 

and in nearly every instance potash was the more abundant of the 

two. In short, if the recorded analyses are correct the clays and 

oozes of the deep sea have been partly leached of 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.

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 any 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, CO3 >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 

i,n the ocean and some of the losses are accounted for, but the great

0 Landw. Versuchs-Station., vol. 21, p. IS 5, 1877. 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. 0, p. 35, 1882.

 ' Monatsh. Chemie, vol. 14, p. 624, 1803 ; vol. 15, p. 530, 1894; vol. 20, p. 1, 1899. .
108 THE DATA OF GEOCHEMISTRY.

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.*

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,6 who 

shows that, if his premises are sound, the primeval ocean must have 

been much richer in calcium and magnesium than the sea is to-day. 

The richness of some artesian waters of Canada in lime salts, waters 

which Hunt regards as fossil remainders from the early sea, may be 

cited in support of his views. On the other hand, R. A. Daly c 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. Hunt's views and Daly's are not necessarily 

antagonistic, for they relate to two distinct eras in oceanic evolution. 

From the earliest ocean, lime might have been precipitated, the loss 

being replenished after life appeared. Arguments of this kind are 

interesting, but by no means conclusive.

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.'* 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

a 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,- p. 388, 1902.

6 Am. Jour. Sci., 2d ser., vol. 39, p. 176, 1865 ; and various papers in his Chemical and 

Geological Essays. See also J. Joly, on the geological age of the earth, in Trans. Roy. 

Dublin Soc., vol. 7, 2d ser., p. 23, 1899; and R. A. Taylor, Proc. Manchester Lit. Phil. 

Soc., vol. 50, p. ix, 1906.

«Am. Tour. Sci., 4th ser., vol. 23, p. 9.3, 1907. ' , 

- '' See T. C. Chamberlln, Tour. Oeol., vol. 5, pp. 653 et seq., 1897 ; also H. L. Fail-child, 

Am. Geologist, vol. 23, p. 94, 1899.
THE OCEAN. 109

") advocates of this doctrine. There is, however, an analogy which may 

be utilized. Meteoric iron frequently incloses anhydrous ferrpus 

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. Daubree ° 

: found lawrenceite in the terrestrial native iron from Ovifak. The 

planetesrmal hypothesis is evidently not inconsistent with the excess 

of oceanic chlorine. It is also in harmony with the idea advanced by 

i E. Suess,6 that the ocean has received large accessions from volcanic 

^ sources. Hydrochloric acid and .volatile chlorides exist in volcanic 

V emanations and must, to some extent, reach the sea. If they were 

first derived from oceanic infiltration, they represent no gain to the 

ocean, and this question is still at issue. For present purposes it need 

not be discussed at greater length.

AGE OF THE OCEAN.

The facts that we can estimate, with a fair 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."

The sodium of the ocean seems to offer us a quantitative datum from

which we can reason. For example, if we accept the figures given in

| Chapter I of this memoir for the relative abundance of the elements,

H it is easy to show that the sodium, is only one-thirtieth of that con-

) tained in the average igneous rock of the 10-mile lithosphere. That

is, if all the sodium in the sea were derived from the decomposition of

igneous rocks, a shell of the latter one-third of a mile thick would

supply the entire amount. An allowance for the sodium retained by

the sedimentaries would increase this estimate to half a mile, which

 is the largest amount possible. All conceivable corrections tend, to 

diminish the figure. A stratum of igneous rock, one-half mile thick 

and completely enveloping the globe, would furnish all the sodium 

of the ocean and the sediments. Joly,d by a similar process of .reason-

" fitudes synthe"tiques de geologic expe"rimentale, p. 557, 1879.

"Geog. Jour., vol. 20, p. 520, 1902. See also C. Doelter, Sitzungsb. Akad. Wien, vol. 

; 112, p. 704, 1903.

'-'This subject-is considered more fully in .Chapter I (pp. 28-29). but a little repetition 

seems to be desirable here.

''Trans. Roy. Dublin Soc., 2d set-., vol. 7, p. 23,. 1899. See also a criticism of Toly by 

W. Mackie, in Trans. Edinburgh Geol. Soc., vol. 8, p. 240, 1902. Mackie points out some 

inadequacies in Joly's data.
110 THE DATA OF GEOCHEMISTRY. <-

ing and in part from the same data, has sought to compute the geo- f 

logical age of the earth since erosion commenced. From Murray's 

estimate concerning the discharge of rivers Joly determines that 

157,267,544 tons of sodium are annually poured into the sea. At 

this rate denudation of the land would require a period of from « 

ninety to one hundred millions of years in order to make up the 

oceanic quantity of sodium. By applying certain corrections the 

figure is reduced to eighty or ninety millions of years as the time 

Avhich has elapsed since water condensed upon the globe and aqueous 

denudation began.

It is not necessary to enter into the details of these and other simi- < 

lar calculations, for they can only be regarded as tentative and preliminary. They do, however, indicate certain possibilities and show 

how desirable it is that we should increase the accuracy of our data. 

When we know more precisely what chemical work is being done by ( 

the rivers, with annual averages for all of the greater continental / 

streams, we may have materials for something like a fair measure of < 

geological time. Our present knowledge on this subject is too incomplete and too unsatisfactory. Some of the difficulties attending the 

problem were pointed out in the preceding chapter.

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 t 

temperature, being greatest in the cold and diminishing as the sol- J 

vent 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 bj 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 -k 

reason 'that some if not all gases are less soluble in salt than in fresh 

water. According to the recent experiments by F. Clowes and 

J. W. H. Biggs,0 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.

"Jour. Soc. CUem. Ind., vol. 23, p. 358, 1904.
THE OCEAN. Ill

To illustrate the difference in solubility between the two principal 

atmospheric gases, we may use the data-given by O. Pettersson and K. 

Sonden/1 In pure water the gases dissolve unequally, and the following table shows their solubility throughout a fair range of atmospheric temperatures. The figures represent the number of cubic centimeters of each gas, at 760 millimeters pressur.e, required to^saturate 

1 liter of water; and the last column gives the percentage of oxygen in 

the dissolved mixture, when N-|-O=100.

Solubility of nitrogen and oxygen in water at 'various temperatures.

Temperature.

0

(>. 00

I). 32

9.18

13.70

14.10

Nitrogen 

absorbed.

cm3 .

19. 53

16. 34

16. CO

15. 58

14. 16

14.16

Oxygen 

absorbed.

an3 .

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,6 assisted by S. Svendsen, made 

94 analyses of air extracted from the water of the North Atlantic 

and found the oxygen in the mixture N-(-0 to range from a minimum 

of 31.0 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 

Avith 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,'-' 

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,d whose 

samples of dissolved air came from many points in the Atlantic, 

Pacific, Indian, and Antarctic oceans. . The maximum amount was 

found in the Antarctic 28.58 cubic centimeters of air to the liter of 

water, containing 35.01 per cent of oxygen. The minimum, 13.73

" Ber. Deutsch. chem. Gesell., vol. 22, p. 1439, 1880. See also R. W. Bunsen, Gasometrische Methoden : W. Dittmar. in his Challenger report; and A. Hamberg. Blhang K. 

Svensk. Vet.-Akad. Handl., vol. 10, No. 13, 1884.

6 Den Norske Nordhavs-Expedition, Chemistry, pp. 1-23, 1880. Tornoe in this memoir 

gives a good summary of the earlier investigations.

'' Die Ergelmisse der TJntersuchungsfahrten S. M.- Knbt. Drache, Berlin, 1886. An 

earlier memoir by .Tacobsen is printed in Liebig's Annalen, vol. 167, pp. 1 et seq., 1873.

<* Challenger rept., Physics and chemistry, vol. 1, 1.884. For the table cited below, seep. 

224. Also for a summary of the results obtained, see the " Narrative " of the expedition.
112 THE DATA OF GEOCHEMISTRY.

cubic centimeters and 33.11 per cent, was obtained at a point southeast of the Philippine Islands. The general conclusions as to the 

solubility of nitrogen and oxygen in sea water at different temperatures appear in the following table:

Solubility of nitrogen and oxygen in sea water at various temperatures.

Temperature.

0

5

10

15

20

25

30

35

Dissolved 

nitrogen.o

15.60

13.86

12.47

11.34

10. 4f

9.62

8.94

8.36

Dissolved 

oxygen.a

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-combined a 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 ' ' 

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

"A much used but inexact expression. It describes the second molecule of carbonic 

acid which converts the normal salts into bicarbonates.

b Compt. Rend., vol. 90, p. 1410, 1880. See also A. Krogh, Meddelelser om Greenland, 

vol. 26, pp. 333, 409, 1904.
THE OCEAlSr. 113

acid: Jacobsen, Hamberg, Tornoe, Buchanah, Dittmar, Natterer, and 

others have made numerous determinations of its amount, and as a 

general rule the quantities found were insufficient to transform all of 

the normal calcium carbonate into the acid salt. Tornoe, as the average of 78 sea-water analyses, found 52.78 milligrams to the liter of 

fully combined carbon dioxide, and in addition 43.64 milligrams available for the formation of bicarbonates. Results of the same order 

were obtained by Natterer in his examination of waters from the Mediterranean. Normal carbonate and bicarbonate are both present in 

sea water, although in a few exceptional determinations during the 

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. B.uchanan on shipboard, and partly by 

W. Dittmar on land." The combined acid has already been accounted 

for in the analyses given for sea salts; the " loose," free, or half-combined acid, is more variable. Its average amount, in milligrams to 

the liter, at different temperatures appears in the following table:

Average amount of free carbonic acid in sea water at various temperatures.

[Milligrams pfer liter.]

Temperature:

25 to 28.7____________ 35. 88

20.to 25 ______________ 37.18

15 to 20 ______________ 42. 68

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 average quantity is estimated by Murray at 45 

milligrams per liter, which is equivalent to a layer of carbon 3.45 

centimeters thick over the entire oceanic area. For different depths 

of water the variations in carbonic acid are less pronounced, as may 

be seen from the subjoined averages:

Average amount of free carbonic acid in sea ivater at various depths. 

[Milligrams per liter.]

Surface_ _. _ 42. 6

25 fathoms _______________ 33.7

50 fathoms______________ 48.8 

100 fathoms_________.-_____.__ 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

0 See vol. 1 of the report on physics and chemistry and part 2 of the " Narrative," p. 

979; also J. Y. Bucbanan, in Proc. Roy. Soc., vol. 22, pp. 192, 483, 1874. The tables 

cited are from the " Narrative."

14399 Bull. 330 08 8
114 " THE DATA OF GEOCHEMISTRY. ^

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. i ,_

In the light of the evidence just presented, and speaking from the 

point of view of the modern theory of solutions, we may say that the 

water of the ocean contains not only the normal carbonic ions. C03 , 

but also a considerable proportion of the bicarbonic ions, HC03 . 

The latter ions 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.,a from the standpoint of the physical chemist, 

and his memoir should be consulted for the detailed argument. The 

essential features of the evidence upon which a theoretical discussion 

can be based are already before us. We have considered the oceanic 

losses and gains of carbon dioxide, and it remains to correlate them 

with the corresponding changes in the atmosphere. This can not be 

done quantitatively, for the rates of consumption and supply are not , 

measurable. In particular, the carbon dioxide from volcanoes and 

volcanic springs is not a determinable quantitjr. Certain large factors in the problem are, however, recognizable, and we can trace to 

some degree their influence upon climate.

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 r 

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 climatic significance of carbon 

dioxide were cited 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 possible ., 

explanation of alternating climates. A variable consumption of

« Jour. Geol., vol. 7, p. 585, 1899.
THE OCEAN. 115

carbon dioxide would obviously produce much the same effect, and 

it is therefore evident that supply and loss must be considered together. This has been done by T. C. Chamberlin in an interesting 

series of papers," in which the ocean is represented as a prime agent 

in producing the observed changes. The supplies are drawn from the 

storehouse of the ocean, they are consumed in the decomposition of 

silicates on land, and they are regenerated by the action of limesecreting animals, which set carbonic acid free, as well as by changes 

in temperature.

i 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 

produces a lowering of temperature, which is increased by the consequent greater absorbability of carbon dioxide in sea water; the 

second causes a relative rise, intensified by a release of the gas from 

solution. Enlargement of land area implies a low temperature, 

whereas a decrease is conducive to warmth, both conditions hinging 

on the variability produced in the atmospheric supply of carbonic 

acid and its effectiveness as a retainer of solar radiations.

But this is not all of the story. A depression of the land is 

accompanied by an increased area of shoal Avater 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 seem 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. That 

the carbon dioxide of the ocean and the atmosphere plays an important part in regulating climates is apparently beyond doubt.

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.6

"Jour. Geol., vol. 5, p. 653, 1897; vol. 6, pp. 459, 609, 1898; vol. 7, pp. 545, 667, 751, 

1899. Chnmberlin's views are criticised by A. .Krogh in Meddelelser om Greenland, vol. 

26, pp. 333, 409, 1904.

"The abundance of life in the ocean is admirably stated by W. K. Brooks, in .Tour. Geol., 

vol. 2, p. 455, 1894. Its cbemical significance can hardly be exaggerated.
116 THE DATA OF GEOCHEMISTRY.

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.* 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. 6 

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,0 is particularly effective in bottom waters in contact 

with " blue mud," and by it local changes are produced in the composition of the waters themselves. Bacteria also assist in the process, and according to N. Androussof,d this H,S 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

0 See W. L. Carpenter in C. Wyville Thomson's Depths of the Sea, pp. 502-511, 1874. 

Where CO2 was abundant in bottom waters, the dredge brought up a good haul of living 

forms. Where it was deficient, the hauls were poor.

6 See J. Murray and R. Irvine, Proc. Roy. Soc. Edinburgh, vol. 17, p. 89, 1889.

c Trans. Roy. Soc. Edinburgh, vol. 37, p. 481, 1895. See also Challenger Rept., Deepsea deposits, p. 254, 1891; W. N. Hartley, Proc. Roy. Soc. Edinburgh, vol. 21, p. 25, 1897 ; 

,and Murray and Irvine, idem., p. 35.

d Guide des excursions du VII. Cong. ge"ol. internat., No. 29.
THE OCEAtt. 117

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.
CHAPTER V. 

THE WATERS OF CLOSED BASINS.

PRELIMINARY STATEMENT.

In dealing with the ocean and its tributary rivers we have studied 

the hydrosphere in its larger sense, the waters all forming part of one 

great system of circulation which can be treated as a unit. But on 

all the continents there are isolated areas from which the drainage 

never reaches the sea. Streams originate in the higher portions of 

such areas, resembling in all respects those tributary to the ocean. 

Their waters gather in depressions and, ultimately, by the concentration of their saline constituents form salt or alkaline lakes or even 

dry beds of solid residues. The latter condition is developed in 

small areas of great aridity, where evaporation is so rapid that no 

large body of water can accumulate; but the more important closed 

basins are characterized by the formation of permanent reservoirs, 

such as the Caspian, the Great Salt Lake, and the Dead Sea. Each 

basin exhibits individual peculiarities of more or less local origin, 

and therefore each one must be studied separately. No such uniformity as that shown by the ocean is manifested here, although in 

some lakes we can recognize a curious approximation in chemical 

character to that of the open sea.

THE BONNEVIJLIjE 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,* 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

0 G. K. Gilbert, Lake Bonneville: Mon. I, 1890. I. C. Russell, The geological history 

of Lake Lahontan, Mon. XI, 1885.

118
THE WATERS OP CLOSED BASINS. 119

several times greater than that of sea water. An early, incomplete 

analysis by L. D. Gale and a questionable one by H. Bassett are 

hardly worth reproducing.*1 The other available data, expressed in 

percentages of total salts, are as follows:

Analyses of water -from Great Salt Lake.

A. By 0. D. Alien," Rept. U. S. Geol. Explor. 40th Pur., vol. 2, p. 433, 1877. Water collected in 1869. A trace of boric acid is also reported, in addition to the substances named 

in the table.

B. By Charles Smart. Cited in Resources and Attractions of the Territory of Utah, 

Omaha, 1879. Analysis made in 1877.

C. By E. von Cochenluuisen, for C. Ochsenius, "> Zeitschr. Deutsch. geol. Gesell., vol. 34, 

p. 359, 1882. Sample collected by Ochsenius April 16, 1879.

D. By J. F. Talmage, Science, vol. 14, p. 445, 1889. Collected In 1885.

E. By Talmage, loc. cit. Collected in 1889.

F. By B. Waller, School of Mines Quart., vol. 14, p. 57, 1892. Waller also reports a 

trace of boric acid.

G. Dittmar's average composition of sea salts, inserted here for ease of comparison.

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

Br.............................

S04-. ..........................

COs.. ..........................

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

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

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

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

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

Fe203, A12 03 , SiOs ... :.........

A.

55.99

6.57

^rftcc

33. .15

l.CO

.17

2.52

100.00 

14.994

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.

54.38

7.76

3471

1.19

.20

1.70

100.00 

16. 710

E.

56.54

5.97

33.39

1.08

.42

2. CO

100.00 

19.558

F.

55.69

6.52

.01

32.92

1.70

1.05

2.10

.01

100.00 

c 23. 036

G.

55. 292

.188

7.692

.207

30. 593

1. 106

1.197

3.725

100.000 

3.5

"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.

* Ochsenius also gives an analysis of the salt manufactured from' the water of Great 

Salt Lake.

c More correctly, 230.355 gram's per liter.

Although the salinity of the lake is from four to seven times as 

great as that of the ocean, its saline matter has very 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.6 The following table relates to some of the streams, except that Sevier Lake, an outlying remnant of Lake Bonneville, is

0 They are cited in Gilbert's monograph. Bassett's analysis is exceedingly high in 

potassium.

6 In addition to the data given here, see analyses by J. T. Kingsbury, of City, Red 

Butte, Farmington, Emigration, Parleys, Big Cottonwood, and Little Cottonwood creeks, 

cited by G. B. Richardson iii Water-Sup, and Irr. Paper No. 157, U. S. Geol. Survey, p. 30, 

.1906; analyses made in 1882 and 1884. Field Operations Bureau of Soils, U. S. Dept. 

Agric., 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.
120 THE DATA OF GEOCHEMISTRY.

included as a matter of convenience. ' The analyses are all reduced to 

standard form, with bicarbonate radicles recalculated to normal CO3 . 

Salinity is stated in parts per million:

Analyses of waters tributary to Qreat Salt Lake.

A. Bear River at Evanston, Wyoming. Analysis by F. W. Clarke, Bull. U. S. Geol. 

Survey No. 9, p. 30, 1884.

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. Camcron, 

Rept. No. 64, Bureau of Soils, U. S. Dept. Agric., p. 108, 1900.

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, 

p. 29, 1884.

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. Agric., 1900, p. 226.

H. Sevier Lake. Analysis by Oscar Loew. Rept. Geog. Surv. W. 100th Mer., vol. 3, 

p. 114, 1875. Sample taken in 1872.

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

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

CO3 . .................................

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

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

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

M%. .................................

(AlFe) 2 03 . ..........................

A.

2.68

5.76

52.68

1 4.49

23.69

6.86

3.84

100. 00 

185

B.

32.36

8.16

21.53

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

D34.76

30.68

trace

1 23. 04

10.26

1.26

100.00 

1,090

E.

5.38

2.87

52.57

I 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 

80, 400

Utah Lake, at the head of the Jordan River, has furnished material 

for a most instructive series of analyses, as follows:

Analyses of ivater from Utah Lake.

A. By F. W. Clarke, Bull. U. S. Geol. Survey No. 9, p. 20, 1884.

B. By F. K. Cameron, 1899.

C. By B. E.-Brown 1903.

D. Heap 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, p. 113, 1905. All are here reduced to 

terms of normal carbonates.

Cl..... .............................................. so<...... ...........................................

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

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

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

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

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

Sr : .. ................................................

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

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

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

a

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 71

5.34

6.85

2.23

100.00 

1,254
THE WATERS OF CLOSED BASINS. 121

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 AV ashed 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.0 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 

SiO3 may possibly exist instead of the colloidal Si02 . In no case,

0 See analyses by R. W. Woodward, cited in Kept. U. S. Geol. Explor. 40th Par., vol. 2, 

p. 435, 1877. Also an analysis by T. M. Chatard, in Bull. U. S. Geol. Survey No. 228, 

p. 331, 1904.
122 THE DATA OF GEOCHEMISTKY.

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 troha 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 Pacific 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.

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

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

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

K...... ..'.................................

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

gjQ

(AIFe) 2 03 .........................:......

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.

23.77

21.29

17.34

1 34.83

.90

1.56

.31

100.00 

2,500

The changes shown by these waters 0 are elaborately discussed by 

Russell in his work on Lake Lahontan. Ordinary fresh waters rich 

in carbonates and in calcium are concentrated, and the lime salts are 

finally thrown out in the form of tufa. The tufa, however, instead of 

being an oolitic or granular deposit, as in the Bonneville basin, is in 

the form of crystals, " thinolite," pseudomorphous after some un0 Excepting analysis B, which is more recent.
THE WATERS OF CLOSED BASINS. 123

known 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.*

Four more analyses of Lahontan waters remain to be considered, 

as follows:

Analyses of Lahontan waters II.

G. Humboldt River, Nevada. Analysis by T. M. Chatard.

I-I. Humboldt Lake, Nevada. Analysis by O. D. Alien, Kept. U. S. Geol. Explor. 40th 

Par., vol. 2, p. 743, 1877.

I. The large Soda Lake, Ungtown, 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. 0, 1884. An earlier 

analysis of Soda Lake by 0. D. Alien is given in the Fortieth Parallel report, vol. 2, 

p. 748, 1877. It is less complete than Chatard's, but otherwise not very different. This 

water contains bicarbonates. Specific gravity, 1.101.

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

so,.. ..........................................................

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

P04 .. ........ ..................................................

B4 07 . ..........................................................

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

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

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

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

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

A12 03 ..........................................................

G.

2.19

13.92

39.55

i3. 63

2.92

14.28

3.62

9.51

.38

100.00 

301

H.

31.82

3. 27

21.57

.07

29 97

6.54

1.35

1.88

3.53

100. 00 

929

I.

36.51

10.30

13.78

.25

36.63

2.01

.22

.24

100. 00 

113,700

 J.

35.38

10. 50

15. 89

.26

35.38

2.13

.21

.25

100.00 

113,700

The first two of these analyses show the change from river to 

lake water very clearly. There is a concentration of chlorides and 

a relative loss in silica, magnesium, and calcium. The water of Soda 

Lake is more than three times as concentrated as sea water, and of 

an entirely different type. It has no visible supply of water except 

from springs near its margin, and at certain times it deposits trona 

and also gaylussite in notable quantities. .Gaylussite is a carbonate 

of calcium and sodium, but no calcium is shown by Chatard's analyses. It must, therefore, be deposited by the lake about as rapidly 

as it is received. The tributary springs have not been investigated.

The Lahontan waters, then, are distinctly alkaline, whereas the 

lakes of the Bonneville basin are salt. The cause of the difference 

must be sought in the sources from which the waters are derived, 

and one distinction is clear. Great Salt Lake is fed by streams and 

springs which flow in great part through sedimentary formations. 

Its saline matter is a concentration of old salts which were laid down

«See discussion by E. S. Dana, in Bull. U. S. Geol. Survey No. 12, 1884. Calcite 

pseudomorphs, similar to thinolite and called pseudogaylussite, have been discussed by 

F. .f. P. van Calker (Zeitschr. Kryst. Min., vol. 28, p. 556, 1897) and C. O. Trechmann 

(idem, vol. 35, p. 283, 1902). The Australian glendonite is calcite pseudornorphous after 

glauberite, and sometimes forms crystals 15 to 20 inches long. See T. W. E. David, 

Rec. Geol. Survey New South Wales, vol. 8, p. 162, .1905.
124 THE DATA OF GEOCHEMISTRY.

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 6f alkaline lakes having a general resemblance to those of the Lahontan basin. The subjoined 

analyses are available, and in them, as usual, bicarbonates, if reported, have been reduced to normal form.

Analyses of water from alkaline lakes in California.

A. Mono Lake.". Analysis by T. M. Chatard, Bull. U. S. Geol. Survey No. 60, p. 53, 

1890. Sample taken in 1882. Specific gravity, 1.045.

B. Owens Lake. Analysis by 0. Loew, Ann. Kept. Geog. Surv. W. 100th Mer., 1876, 

p. 190. Specific gravity, 1.051.

C. Owens Lake. Analysis by Chatard, op. cit., p. 58. Specific 'gravity, 1.062.

D. Owens Lake. Analysis by C. H. Stone, cited by W. T. Lee in Water-Sup, and 

Irr. Paper No. 181, U. S. Geol. Survey, p. 22, 1906. '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 Kept. 

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. P. Becker in Mon. U. S. 

Geol. Survey, vol. 13, p. 265, 1888. In addition to the substances named in the table, 

the original residue contained 4.5 per cent of organic matter.

 '

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

Br...... .............................

I....................................

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

C08 .................................

t>n

BA........ .........................

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

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

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

Rb.Cs.......... '...................-.

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

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

SiOj... ...............................

A1203 - .....i. ........................

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

As-jOa ...............................

A.

23.34

12.86

23.42

.32

37.93

1.85

.04

.10

.14

100.00 

51, 170

B.

22.22

15.47

21.72

trace

trace

35.78

4.54

.27

trace

100. 00 

60, 500

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

trace

13.24

37.73

trace

39.05

. 2.03

.27

100.00 

18, 500

P.

17.38

16.91

26.55

33.51

1.82

1.50

1.78

.55

100. 00 

13, 600

G.

20.26

20.77

19.55

35.79

2.44

OQ

.26

.65

100. 00 

49, 100

H.

32. 27

(U

.13

22.47

.02

5.05

38. 16

1.52

n<?

.35

.01

} -

100. 00 

76, 560

"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.
THE WATERS OF CLOSED BASINS. 125

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.

NOBTHEKN 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 allcaline lakes.

A. Abert Lake, Oregon. Analysis by T. M. Chatard, Bull. U. S. Geol. Survey No. 60, 

p. 55, 1890. An earlier analysis by Taylor is not in accord with this.

B. Hartley Lake, Oregon. Analysis by George Steiger in the laboratory of the Survey. 

. C. Soap Lake, Washington. Analysis by Steiger, Bull. U. S. Geol. Survey No. 113, 

p. 113, 1893.

I). Soap Lake. Analysis by H. G. Knight, Ann. Rept. Washington Geol. Survey, vol. 1, 

p. 295, 1901.

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. Rept. Geol. Survey Canada, new ser., vol. 11, p. 48 R, 

1898.

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

so4 ...... .................................

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

po4 ......................................

"DA B ' 4O7 ......................................

Wfi

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

Mg. ...................................... Qin

AloO;,--- ..................................

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

none

.07

.28

none

100.00 

10, 477

C.

13.28

16.44

30.22

1 39.60

trace

.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

1Q Sfi

8.41

7.25

5.06

^ 111

J

100. 00 

2 966

F.

7.64

7.08

41. 41

.62

36.17

6.65

.02

.04

.04

.33

100. 00 

] 03, 470

All of these waters contain bicarbonates. Goodenough Lake deposits natron, Na2CO3 .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.

A few saline lakes situated east of the Rocky Mountains have been 

studied to some extent. The analyses are as follows:

0 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,,
126 THE DATA OF GEOCHEMISTRY.

Analyses of ivater from saline lakes east of the Rocky Mountains.

A. Wilmington Lake, Wyoming. Analysis by E. E. Slosson, Bull. No. 49, Wyoming 

Exper. Sta., 1901.

B. Big Lake.

C. Track Lake.

D. Red Lake. These three lakes are known -as the Laramie or Union Pacific Lakes 

of Wyoming. They are usually dry, but in 1888 were filled with water. Analyses by 

H. Pemberton and G. P. Tucker, Jour. Franklin Inst, vol. 135, p. 52, 1,393.

E. Old Wives or Chaplin Lake, Saskatchewan, Canada. Analysis by F. J. Alway and 

R. A. Gortner, Am. Chern. Jour., vol. 37, p. 3, 1907. Recalculated to 100 per cent from 

the original summation of 98.55.

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

so4 ....... ..........................................

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

B<O7 ...... ..........................................

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

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

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

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

A1 2O3 . ...............................................

SiOs.................................................

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 ^nn

D.

3.06

64.57

.57

29.89

.59

1.32

100.00 

93,100

E.

4 08

61.86

1 ^A

30.65

.97

100.00 

27,300

a These figures for salinity have little or no significance, because the " lakes " vary 

from dry masses of salts to solutions of differing concentration.

Four of these lakes are essentially solutions of sodium sulphate, 

and resemble certain bodies of water on the Russian steppes.

CENTRAL AND SOUTH AMERICA.

For the saline waters of Central and South America the chemical 

data are very scanty. Three analyses, however, may be cited here:

Analyses of saline waters from Central and South America.

A. Lake Chichen-Kanab ("little sea"), Yucatan. Analysis by J. L. Howe and H. D. 

Campbell, Am. Jour. Sci., 4th ser., vol. 2, p. 413, 1896. 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, Desierto i cordilleras de Atacama, .vol. 3, p. 199, Santiago de Chile, 1902.

C. Rio Saladillo, Argentina. Analysis by Siewert, reported by A. W. Stelzner," Beitrilge zur Geol. u. Palaeont. der Argentinischen .Repub., 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, 584,566,200 kilograms of salts.

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

so4 ..... .................................................................

xo3 ................... : .. ................................................

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

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

Pa

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

A.

8.14

58. 64

ii.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

a Stel/ner also gives aualyses by Doering of the Saladillo between Salta and Jujuy, 

and of Arroyo Salado in Patagonia.
THE WATERS OF CLOSED BASINS. 127

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.*

The Caspian Sea, however, is something more than a segregated 

remnant of the ocean. Its water is diluted by the influx of the 

Volga, the Ural, and other important streams, so that its composition 

is intermediate between that of a river and that of the open sea. 

Its salinity is relatively low and very variable. At the north end. 

near the mouth of the Volga, the water is only brackish; in the deeper 

southern portions it is much salter. On the eastern side of the Caspian there is a large gulf, the Karaboghaz, into which a current 

continually flows, through a shallow channel, with no .compensating 

return. This current, it is estimated, carries daily into the gulf 

350,000 tons of salt; and therefore the salinity of the Karaboghaz is 

steadily increasing. Its waters no longer support animal life, and 

saline deposits are forming upon its bottom. Near its margin 

gypsum crystals are formed; toward the center of the gulf sodium 

sulphate is deposited. 6 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 

Avith respect to sodium sulphate, but not for the chloride, and the latter remains dissolved." 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. A cad. St. Petersburg, 

vol. 24, p. 177, 1S7S.

B. Caspian Sea. Analysis by A. Lebedinteeff, cited by W. Stahl, Natur. Wochenschr., 

vol. 20, p. 689, 1905.

C. Karaboghaz Gulf. Analysis by .Schmidt) loc. cit.

« For analyses of some of these waters, the Elton, Bogdo, Indersk, and Stepanova lakes, 

see Roth, Allgem. chem. Geol., vol. 1, p. 469. Modern and complete analyses are much 

to be desired; the old ones are unsatisfactory.

* See S. Kusnetsoff, Zeitschr. prakt. Geol., 1898, p. 2G.

< See N. S. Kurnakoff, Verhandl. Russ. k. min. Gesell., 2d ser., vol. 38, p. 26 of the 

proceedings, .1900. For a long paper on the Karaboghaz, also known as the Karabugas or 

Adschi-darja, see W. Stahl, Natur. Wochenschr., vol. 20, p. 689, 1905. This paper is 

based on an official Russian report by Spindler and Lebedintzeff, published in 1902.
128 THE DATA OF GEOCHEMISTRY.

D. Karaboghaz Gulf. Analysis by Lebedintzeff, 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, Allgem. chem. Geol., vol. 1, 

p. 465. ' Scbmidt'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.

a

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

Br. .......................................

SO*. ......................................

CO3 .... .........'..........................

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

K....:............ ........................

Rb. ......................................

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

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

SiOs, PO<, Fe2O3 . .........................

Salinity, per cent. . .......................

A.

42.04

.05

23.99

.37

24.70

 .54

.02

2.29

5.97

03

100. 00 

1.294

B.

41.78

.05

23.78<) }

24.49

.60

2.60

5.77

100. 00 

1.267

C.

53.32

.06

17.39

11.51

1.83

.06

15.83

100. 00 

28. 50

D.

50.26

.08

15.57

.13

25.51

.81

' .57

7.07

100. 00 

' 16.396

E.

47.99

.13

21.25

18.46

.24

.01

.01

11.91

100.00 

28.90

F.

35.40

.03

30.98

.85

22.62

.54

.02

4.02

5.50

.04

100.00 

1.084

Analyses C and D show that the Karaboghaz varies from time to 

time, both in composition and in concentration.

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 Avhich 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.*

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

0 Bergstriisser, in Petermann's Mittheilungen, 1858, pp. 104-105, has brought together 

thirty-eight old analyses of salts from the lakes of Astrakhan and the mouth of the Volga.
THE WATERS OF CLOSED BASINS. 129

best series of analyses are due to A. Terreil,a 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. One later analysis is included in the table, and 

also one of the River Jordan, the chief tributary of the Dead Sea: 

The reduced data are as follows: &

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 MrabM. 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. Probably surface water. Analysis by H. Fleck, Jour. Chem. Soc., vol. 42, p. 24,

abstract, 1882.

H. River Jordan. Analysis by Anderson, cited from Roth, Allgem. chem. Geol., vol. 1, 

p. 47G. Terreil also made an analysis of this water, but it is obscurely stated. 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,

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

Br...................................

S0<. ............. ...................

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

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

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

Ca. ........;.........................

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

A.

65.81

2.37

.31

11.65

1.85

4.73

13.28

100.00 

19.215

B.

70.25

1.55

.21

6.33

1.70

5.54

14.42

100.00 

20.709

.c.

68.16

1.99

.22

10.21

1.00

1.53

10.89

100.00 

24. 263

D.

67.66

1.98

.22

10.20

1.62

1.51

16.81

100.00 

24. 573

E.

67.84

' 1.75

.22

10.00

1.79

1.68

16.72

100.00 

25.110

F.

6T.30

2.72

.24

5.50

1.68

6.64

15.92

100.00 

25. 998

G.

65.74

1.49

.33

11.60

3.40

 5.02

12.42

100.00 

21. 977

H.

49.45

 3.64

12.72

15.51

1.13

7.89'

9.51

.15

100. 00 

0. 161

From the foregoing analyses we see that the water of the Dead Sea 

differs widely from all the other waters that we have examined. The 

composition of its main feeder, the Jordan, is also unusual. When it 

enters the Dead Sea, its carbonates and gypsum are precipitated, and 

its contribution to the lake brine is composed almost entirely of 

chlorides. The valley of the Jordan and the regions roundabout the 

Dead Sea contain many beds of rock salt and gypsum, and the neighboring Cretaceous strata are impregnated with the same substances. 

From these sources the river derives its chlorides and sulphates, and 

so returns to the lake some products of its former concentration. Hot 

springs, also, as L. Lartet 0 and others have shown, contribute to the

0 Compt. Rend.,, vol. 62, p. 1329, 1S66. The earlier analyses, together with one of his 

own, are elaborately discussed by .T. B. Boussingault, in Ann. chim. phys., 3d ser., vol. 48, 

p. 129, 1856.. ; '

6 More recent analyses of Dead Sea water are by Mitchell, Berg. u. hiittenm. Zeitung, 

1902, p. 225 ; and by A. Stutzer and A. Reich, Chem. Zeitung, vol. 31, p. 845, 1907. 

The older analyses by F. A. Genth (Ann. Chem. Pharm., vol. 1.10, p. 240, 1859) and by 

Roux (Cornpt. Rend., vol. 57, p. 602, 1863) are also worth consulting. . 

"Bull. Soc. g6ol. France, 2d ser., vol. 23, pp. 719-760, 1866. ' ' ' " '

14399 Bull. 330 08 9
130 THE DATA OF GEOCHEMISTKY.

salinity of the waters. To some extent, probably, there is atmospheric 

transportation of salts from the Mediterranean, and W. Ackroyd a 

regards this as a most important agency, although its influence is 

probably overestimated. Whatever may have been the origin of the 

Dead Sea, its water is now essentially a bittern, relatively low in 

sodium, high in magnesium, and remarkably rich in bromine. The 

brine from 300 meters depth carries over 7 grams of bromine to the 

liter, but no iodine has been detected in it.

OTHER RUSSIAN AND ASIATIC LAKES.

Mother liquors having a general similarity to the Dead Sea brine 

are also furnished by the Elton Lake, in southern Russia, and the 

Red Lake, near Perekop, in the Crimea. Their analyses, recalculated 

from the figures given by Roth, appear in the next table. The composition of the Elton water varies with the Season of the year, and I 

have selected an analysis which represents its concentration in August. In spring its tributaries, swollen by melting. snow, bring in 

much sodium chloride and alter its character materially. Analyses 

of water from several Asiatic lakes are included with these in the following table: '

Analyses of certain Russian and Asiatic waters.

A. Elton Lake, Russia. Analysis by Erdmann, cited by Roth, Allgei". chern. Geol., 

vol. 1, p. 469. , 

B. Red Lake, Perekop, Crimea. Analysis by Hasshagen, from Roth, op. cit, p. 471. 

Roth gives analyses of several other Crimean salt lakes.

C. Lake Van, Armenia. Analysis by E. de Chancourtois, Compt. Rend., vol. 21, p. 

1111, 1845. 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, p. 312, 1899. .

E. Salt lake near Shiraz, Persia. Analysis by K. Natterer, Monatsh. Chernie, vol. 16, 

p. 658, 1895.

F. Gaukhane 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, p. 

177, 1878. Bicarbonates reduced to normal salts. Sample taken in autumn, 1872.

H. Koko-Nor, Tibet. Analysis by Schmidt, He'1. chfm. phys., St. Petersburg, vol. 1.1, 

p. 487, 1881. Sample taken in the winter of 1880, from under thick ice.

PI

Br...... .............................

I............................... ....

GA

r"/v

Na .................................. K.... ..............................:

Rb. .................................

NH4 .................................

Mg....... ....... ....7. ..............

Si02 - ................................

Fe20s.... ............................

P0<... ...............................

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

]).

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 9Q

37.38

.82

.83

.01

160. 00 

25.88

G.

40.05

.04

17.84

5.55

30.60

1 fiS

.04

1.77

2.90

09

.02

.02

100. 00 

1.11

H.

41 69

' 04

16. 30

6.66

28.64

01

.04

.04

5.66

08

.02

.02

100.00

1 9ft

"Chem. News, vol. 89, p. 13, 1904.
THE WATERS OF CLOSED BASINS. 131

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.

I In the neighborho9d 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.0 The reduced analyses, 

arranged in the order of their chlorine, are as follows:

Analyses of water from saline lakes of Yeniseislc, Siberia,.

A. The Kisil-Kul.

B. Lake Schunett, water collected In 1899."

C. Lake Tngar.

D. LakeBelsk. ^

E. Bitter Lake.

F. Lake Altai.

G. Lake Biljo. This is the largest of the 

lakes and measures about 00 kilometers in circumference.

H. Lake Domoshakovo.

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

Br. ..................................

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

rn~wr»

JN 03 .................................

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

On ................................ : .

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

AljOs------ ..........................

FeoOa ...............................

A.

48.28

14. 55

.22

34. 01

.35

.69

1.86

.04

100. 00 

10.87

B.

38.89

32.19

.31

.33

.44

11.67

.01

.04

100.00 

15.19

C.

29.52

34.99

1,55

28.41

1.01

.27

4.12

.04

.09

100.00 

2.09

D.

22.79

42.32

.61

1.01

.07

1.86

.01

.01

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

.52

.05

.90

(13

.02

.01

100.00 

10.88

G.

9.91

52.33

6.22

1.07

21.83

.87

.43

7.28

.03

.03

100. 00 

0.88

H.

3.71

63.62

.08

.07

30. 61.

.59

.58

.74

100. 00 

14 55

0 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.

The last analysis in this table, that of Lake Domoshakovo, represents essentially a solution of sodium sulphate, with very little else. 

It is the extreme type of a sulphate water. The other waters, upon 

evaporation, yield mixtures of chlorides and sulphates, sodium being 

the dominant electropositive radicle. In one analysis only is magnesium high; in two others it is important. The calcium is insignificant 

throughout the series.

0 Zeltsclir. prakt. Geol., vol. 11, p. 401, 1903. Ludwig also gives analyses of sediments 

and saline deposits from these waters.
132 THE DATA OF GEOCHEMISTKY.

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: °

Analyses of water -from Siberian lakes.

A. Issyk-Kul. M61. phys. chim., St. Petersburg, vol. 11, p. 623, 1882. 

B. Iletsk salt lake, government of Orenberg. Op.' cit, vol. 11, p. 608, 1882. Average. 

 C. Barchatow bitter lake, 300 versts southwest of Barnaul, government of Tomsk. Op. 

cit., vol. 11, p. 609, 1882.

D. Buluktu-Kul or Fish Lake, Kirghiz Steppe. Op. cit., vol. 12, p. 37, 1883. *

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

Br... ..........................................................

S0 4 ...... ......................................................

C03 . ................................. .^........................

PO............................................................

Wfl

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

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

Mg............................................... r ............

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

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

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

OQ A1

.26

5.84

.50

100. 00 

13,308

D.

37.96

.04

27.39

.98

23 29

v>

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:

Analyses of water from several European lakes.

 A. Lake Laach, Germany. Analysis by G. Bischof, Lehrb. chem. phys. Geol., 2d ed., 

vol. 1, p. 316, 1863. This lake occupies'the crater of an extinct volcano, and its water is 

fresh.. Jt 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, p. 361, 1856. 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. Illy^s or Medve Lake, near Szovata, Hungary. Analysis by B. von Lengyel, Fb'ldt. 

Kozl., vol. 28, p. 280, 1898. Recently formed by a sinking of the ground. The neighboring country contains salt deposits.

D. Lake Ruszanda, Hungary. Analysis by .T. Sclmeider, cited'by A. Kaleczinzky, Fb'ldt. 

Kozl., vol. 28, p. 284, 1889. 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, p. 158, 1901. 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. 6 Analysis by Carnot, cited by Bujor, op. cit., p. 176. In 

winter this lake deposits crystallized sodium sulphate, mirabilite, Na2SO4.10HoO.

"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.

& In a memoir entitled "Apergu gSologique sur les formations saliferes et les gisements 

de sel.en Roumanie," Bucharest, 1902, L. Mrazec and W. Teissey.re cite analyses of Lacu 

Sarat, Lacu Fundata, Lacu Arnara, and Lacu lanca. They also give analyses of' Roumanian salt.
THE WATERS OF CLOSED BASINS. 133

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

Br.. .......... ............................

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

C08 ..... .................................

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

P04 .......................................

NH4 .... ..................................

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

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

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

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

Ala03 .. ...................................

FCa03,.... ................................

Sid».... ....... ...........................

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

OC

.27

100. 00 

2,215

c.

60.18

.44 .04'

39.02

9^

AO

.04

100. 00 

233, 747

D.

19.07

22. 50

19.22

'.52

37.07

1.19

9f>

1^

j- traces

.02

100. 00 

0,276

E. .

60.53

.18

.67

34.78

1.68

.28

1 84

| .03

.01

300.00 

70, 877

F.

28.25

07 TO

.27

'-il 7t\

.39

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,0 they have warm layers under a freshAvater surface, which owe their increased temperature to the absorption of solar heat and to the fact that brine has a lower specific 

heat than water. The surface layer of Black Lake has a temperature 

of 21°; the warm layer below reaches 56°. These lakes, therefore, 

are accumulators of heat.

With the analyses of four more lake waters, the present tabulation 

must close. They are as follows:

Analyses of water from several lakes of Africa and Australia.

A. Natron Lake, near Thebes, Egypt. Analysis by E. Willm, Compt. Rend., vol. 54, p. 

1224, 1862-. No bromine, iodine, nitrates, or sulphates were detected.

B. Salt lake 32 kilometers north of Pretoria, Transvaal. Described by E. Cohen, Min. 

pet. Mittli., vol. 15, pp. 1, 1.94, 1895. 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 Katwce salt lake, north of Albert Edward Nyanza, central Africa. Analysis 

by A. Pappe and.IL D. Richmond, Jour. Soc. Chem. Ind., vol. 9, p. 734, 1890.

D. Lake Corongamlte, Victoria, Australia. Analysis by A. W. Craig and N. T. M. 

Wilsmore, Fourth Kept. Australian Assoc. Adv. Sci., p. 270, 1892.

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

Br.............................................................

SO, ................ 1 ...........................................

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

Na............................... '...... :.....................

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

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

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

(AlFe) 2O3 . ....................................................

SiOj. ..... :..................-..................................

A.

26.00

32. 90

31.05

3.57

3.62

1.50

1.36

100. 00 

4,407

B:

43/47

.03

35.17

41.33

100. 00 

211,400

C.

36.67

J2.33

10.42

'33. 46

7.09

trace

trace

'.03

100.00 

310,000

D.

 ; * 

59.32

.22

1.65

undet.

35.07

.84

.13

2. 77

.100.00 

46,039

0 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 

Lake; the salinity is 19.53 per cent.
134 THE DATA OF GEOCHEMISTRY. 

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. . .......................

Kio SaladiUo .............................

Cl, Br.

60.71

60.26

60.18

59.67

59.54

58.18

57.33

56.74

55. 73

55.48

S0<.

0.67

.47

.44

1.29

1.65

3.48

5.06

4.82

6.76

7.69

C03.

0.04

(?)

.23

.01

.21

Na, K.

36.46

38.86

39.02

37.38

35.91

35.80

34. 76

36.40

34.67

31.70

Ca.

0.28

.33

.25

.82

.13

.46

.32

1.63

.37

1.20

Mg.

1.84

.08

.03

.83

2.77

1.84

2.53

.41

2.45

3.72

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,® in his discussion of l 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 the preceding group of waters 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:

« Monatsh. Chemie, vol. 1G, p. 666, 1895.
THE WATEHS OF CLOSED' BASINS. 

Principal constituents of natural Mtterns.

135

Red Lake. .............................

Cl, Br, I.

69.52

66.96

64.22

S0<.

0.25

6.82

C03 .

.04

Na, K.

11.22

19.90

11.27

Ca.

3.81

2.01

.10

Mg.

15.18

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 sulphate waters.

Kisil-Kul. ................................

Lake Tagar . ......... ...................

Cl, Br.

52. C6

50.44

48.28

29.52

28.25

22.79

20.02

14.38

4.98

4.88

3.71

- SO,.

10.88

9.17

14.55

34.99

37.12

42.32

43.63

 50.14

61.86

 62. 34

63.62

C08.

0.22

1.55

.27

.61

1.53

1.12

1.54

.08

Na, K.

33.33

37.64

34.36

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

Some of these waters have been modified by human agency, which 

utilized.them as sources of salt. They form, nevertheless, a natural 

series, in which the alkaline radicles are nearly constant in proportion, while the chlorides and sulphates vary reciprocally.

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 siilphato-chloride waters.

Buluktti-Tvul. ............................

Cl, Br.

45.16

41.96

38.00

35.43

S0<.

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.

5.84

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.
136 THE DATA OF GEOCHEMISTRY.

Principal constituents of sulphato-chloride waters of the bittern type.

Cl, Br.

51.86

48.12

38.89

15.67

S04 .

16.48

21.25

32 19

55.94

C03 .

0.07

.31

1.26

Na,K.

18.33

18.70

16.45

13.61

Ca.

0.28

.01

.44

.94

Mg.

11.45

11.91

11.67

12.50

The water of Lake Chichen-Kanab in Yucatan is also sulphatechloride water, but it stands alone as the only known member of a 

distinct subgroup.

Principal constituents of water of Lake Chichen-Kanab.

Chichen-Kanab. . .........................

Cl.

8.14

SO4 .

58.64

COs'. Na, K.

12.42

Ca.

13.49

Mg.

7.31

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.

Cl, Br.

3.88

4.99

7.64

7.68

15.68

S04 .

2.87

2.97

7.08

13.24

2.92

C03.

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

2.77

.04

3.35

In the next group of waters carbonates and chlorides predominate, 

with sulphates in subordinate quantity.

Principal constituents of carbonate-chloride waters.

Cl, Br.

26.00

27.50

32.31

31.82

36.04

43.47

41.04

47.88

S04 .

7.67

.13

3.27

1.90

.03

5.25

3.76

.COs.

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

none

.03

1.35

.25

.55

Mg.

3 fi9

.07

.35

1.88

2.28

.49

Borax Lake, which also, contains 5.05 per cent of B4 07 in its saline 

residue, might well be put in a class by itself; but extreme subdivision * 

is not now desirable.
THE WATERS OF CLOSED BASINS. 137

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.

Lake Van. ................................

Cl, Br.

. 10. 78

13.07

25.67

23.34

18.82

27.08

19.07

23.77

35. 95

36.07

SO<.

16.62

' 16. 62

9.95

12.86

18.84

11.95

22.56

21.29

10.42

12.33

C03 .

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.

0.02

.04

.89

.20

.90

Mg.

0.17

.01

.10

].02

.57

.15

1.56

.22

Finally there are two waters which might be classed with the sulphato-chlorides, were it not for their moderately alkaline character. 

Principal constituents of water of Lakes Biljo and Koko-Nor.

Lake Biljo. ...............................

Cl, Br.

9.91

40.09

S0<.

52.33

17.84

CO3 .

6.22

5.55

Na, K.

22.70

31.72

Ca.

0.43

1.77

Mg.

7.28

2.90

In general, as was pointed out in discussing the Lahontan waters, 

alkaline lakes are representative of volcanic regions, while saline 

lakes are associated with sedimentary deposits. That is, from a 

chemical point of view the alkaline waters are the newest, and exhibit 

the nearest relationship to rivers and springs. By the weathering 

of rocks carbonates are first formed, as is seen in most rivers near 

their sources. Under favorable conditions these salts accumulate, 

and they are transformed into or replaced by other compounds only 

after a long and slow series of chemical reactions. In recently 

formed bodies of water, derived from igneous rocks, carbonates are 

abundant; but as salinity or concentration increases, the slightly 

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 comming-
138 THE DATA OF GEOCHEMTSTEY. .

ling will follow the order just laid down. This order can not be 

stated in 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 

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 deppsition is simply the general order,

which conforms to the facts of observaton and to the known solubilities of the several salts. The least soluble possible salt will form 

first; the most soluble will remain longest in solution. The formation 

of double salts will be considered in another chapter.
CHAPTER VI.

MINERAL WELLS AND SPRINGS. 

DEFINITION.

Between the so-called " mineral waters " and waters of ordinary 

character no sharp line of demarcation can be drawn. In fact, some 

of the springs having the greatest commercial importance yield 

waters of exceptionally low mineral content and owe their value to

their remarkable purity. They are simply potable waters carrying a

minimum of foreign matter in solution. Other springs, on the contrary, are characterized by excessive salinity, and between the two 

extremes nearly every intermediate condition may be observed.

In the chapter on lakes and rivers a number of springs were considered, which represent the ordinary or common type of water supply. Rain water, charged with carbonic acid, percolates through 

the soil or through relatively thin layers of rock, and emerges with a 

moderate load of dissolved impurities Upon evaporation such 

waters give a residue consisting most commonly of calcium carbonate,

/ calcium sulphate, or silica, with minor amounts of alkaline chlorides; 

and, blending with rain or seepage waters, they form the beginnings 

of streams. Sometimes sulphates predominate, sometimes carbonates, 

but chlorides are present much less conspicuously. Calcium is the 

dominating metal, and sodium occupies, as a rule, a subordinate place. 

To the vast majority of spring waters these statements apply; but 

here and there exceptions are encountered which, by their peculiar 

characters, attract attention and are known as " mineral" wells or 

springs. Speaking broadly, all springs are mineral springs, for all 

contain mineral impurities; but in a popular sense the term is 

restricted to waters of abnormal or unusual composition. A mineral 

water, then, is merely a water which differs, either in composition or

; in concentration, from the common potable varities. The term is 

. loose and indefinite, but it has a certain convenience, and we may use 

it without danger of being led astray.

^' T 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

x^ beds of salt, is charged with sodium chloride; another represents the 

solution of gypsum; a third may carry substances derived from the 

sulphides of metalliferous veins, and so on indefinitely. Any soluble

139
140 THE DATA OF GEOCHEMISTRY.

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 be distinctly radioactive, and in a 

large number of instances argon and helium, albeit in small quantities, are among the gases that the waters hold in solution. These 

minor characteristics of natural waters can not be dwelt on here.a 

Their full significance is yet to be determined.

CLASSIFICATION.

The classification of waters can be based on a variety of considerations. It may be geological, correlating the springs with their geological 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 follows 

the lines laid down in the preceding chapters. Waters are classed 

according to their negative radicles, as chloride, sulphate, carbonate, 

or acid waters, with various mixed types and occasional examples in 

iwhich 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 T 

according to any .hard-and-fast system, but must be dealt with some- ' f 

what 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.

0 On argon and helium in mineral waters see especially C. Moureu and R. Biquard, 

Compt. Rend., vol. 143, p. 705, 1906. Moureu in nn earlier paper (idem, vol. 142, p. 

1155, 1906), has given good references to the literature of the subject.
MINERAL WELLS AND SPBINGS. 141

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.0 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.

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, p. 38, 1893. 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, p. 183, 1873-6.

D. Brine from Zilwaukie, Michigan. Analysis by H. C. Hahn, Geol. Survey Michigan, 

vol. 3, p. 186, 1873-6.

E. Humboldt salt well, Minnesota. Analysis by C. F. Sidener, Ann. Kept. Geol. Survey 

Minnesota, vol. 13, p. 101, 1884.

F. Brine from Hutchinson, Kansas. Analysis by E. H. S. Bailey and E. C. Case, 

Univ. Kansas Geol. Survey, vol. 7, p. 79, 1902.

G. Artesian well, Abilene, Kansas. Analysis by E. H. S. Bailey and F. B. Porter, 

Univ. Kansas Geol. Survey, vol. 7, p. 130, 1902. Well 1,260 feet deep.

H. Bryan's well, Bistineau, Louisiana. Analysis by M. Bird, Kept, 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.........................'...........

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

CO3 ....... ...........................

P0<............................:....

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

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

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

Mg...,.:. ............................

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

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

FejOs............... .................

AUOs. ...............................

SiOs.... .............................

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.

61.27

.52

32.76

4.25

1.20

100.00 

20.24

D.

61.59

.24

32.21

4.47

1.45

.04

100. 00 

24.00

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

.11

03

100. 00 

29.31

G.

61.65

29

.07

01 CT

4.85

1 ^9

.05

100.00 

17.89

H.

59.96

37.20

. :)4

29

.03

.98

100.00

8

QO

a In Ann. Kept. Geol. Survey Canada, vol. 15, p. 23G S, 1902-3, G. C. Hoffman gives 12 

analyses of brines from Manitoba. A brine from a well 1,920 feet deep, at Sand Beach, 

Michigan, analyzed by S. P. Duffleld (Geol. Survey Michigan, vol. 5, pt. 2, p. 82, 1895), 

is unusually rich in bromine. C. W. Foulk (Bull. No. 8, Geol. Survey Ohio, p. 27, 1906) 

reports a brine from Pomeroy, Ohio, which is free from sulphates, but contains notable 

amounts of barium and strontium chlorides.

6 1=0.0063 gram per liter. This is less than 0.01 per cent of the total solids.
142 THE DATA OF GEOCHEMISTRY.

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.

Analyses of chloride waters I.

A. .Cincinnati artesian well, Cincinnati, Ohio. Analysis by B. S. Wayne, cited by A. C. 

Peale, in Bull. U. S. Geol. Survey No. 32, p. 133, 1886. This water contains considerable 

quantities of free H2S and C02.

B. Upper Blue Lick Spring, Kentucky. Analysis by J. F. Judge and A. Fennel, cited 

by Peale, op. cit, p. 111. Also rich in H2 S and C02. I represent here by X an indeterminate mixture of Ca3P208, A12O3, and Fe»03.

C. Montesano Springs, Missouri. Analysis by P. Schweitzer, Geol. Survey Missouri, 

vol. 3, p. 77, 1892. This volume contains many analyses of Missouri mineral waters.

D. Deep well at Brunswick, Missouri. Depth 1505 feet. Analysis by Schweitzer, 

op. 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, p. 30, 1884.

F. Spring at Pahua, New Zealand. Analysis by W. Skey, Trans. New Zealand Inst, 

vol. 10, p. 423, 1877." This spring is notable from the fact that it contains free iodine. 

According to J. A. Wanklyn (Chem. News, vol. 54, p. 300, 1886) the water of Woodhall 

Spa, near Lincoln, England, has the same peculiarity. The iodine colors the water brown 

and can be extracted by carbon disulphide.

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

Br.. .......................................

S04 . ..'..........-.......... ...............

r>n

PO, ......................................

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

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

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

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

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

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

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

Fe2O3 . ....................................

SiO2 ............. .........................

X ........................................

. A.

55.83

.04

.03

3.12

2

ftO

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. i.5

9 3ft

.17

100. 00 

8,509

D.

52.74

8.36

1

QQ

30.15

2 ftO

04

100. 00

1 ^ QfK

.E.

58.79

94

30.38

3

*7C

4 90

.40

.02

.20

100. 00

no ona

F.

60.78

.11

.15

.17

.05

34.81

.02

sj.ii

.60

.01

.12

100.00 

21,060

a In analyses D and F the bicarbonates of the original statement have been reduced 

to normal salts. .
MINERAL WELLS AND SPBINGS. 143

G. Water of Salsomaggiore, Italy. Analysis by R. Nasini and F. Anderlini, Gazz. 

chim. ital., vol. 30, 1, p. 305, 1900. Contains in 1,000 grams 0.00223 gram Mn and 

0.00792 gram B4 07. These are less than 0.01 per cent of the total solids.

H. The Marienquelle, Bavaria. Analysis by A. Lipp, Ber. Deutsch. chem. Gesell., vol. 

30, p. 309, 1897. Contains also much free CO«.

I. The Kochbrunnen, Wiesbaden, Germany. Analysis by C. 11. Freseuius, Jahrb. 

Nassau. Ver. Naturkunde, vol. 50, p. 20, 1897.° This water also contains 0.000013 

gram iodine, 0.00002 gram P04, and 0.00016 gram AsO4 to the liter, each recorded here 

as.a " trace."

T. Water of Arva-Polhora, Hungary. Analysis by W. Kalmann anl M. Glaser, Min. 

pet. Mitth., vol. 18, p. 443, 1898-99. 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. Chern. 

Soc., vol. 39, p. 500, 1881. The memoir contains some other anatyses.

L. Chlpride of Iron Spa, Hnrrogate. Analysis by C. H. Bothamley, Jour. Ghem. Soc., 

vol. 89, p. 502, 1881. The same author, in vol. 63, p. 685, 1883, gives analyses of 

waters from Askern, Yorkshire.

ci.... ....................................

Br..... ...................................

I.........................................

T?.... .....................................

S04 - ......................................

S

'

C0a ......................................

P04 .......................................

Tt f\

Bo

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

K.... ............ .,,... ...................

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

NH4 ...... ................................

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

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

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

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

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

Fe" ......................................

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

Cu..... ..................................

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

G.

61. 09

.15

.03

.18

34.04

.07

.12

3.21

.24

.82

.03

.01

.01

100. 00 

159, 000

H.

52. 72

.42

.64

7.CC

trace

33.08

4.15

1.34

.09

100. 00 

2, 970

I.

50.58

.04

trace

.78

3.13

.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

.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

.1.0

. 2. 39

.30

100.00

0 For other analyses of Wiesbaden waters see the same journal, vol. 49, pp. 22, 23, 1896.

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 Avhich substances 

like bromine, iodine, sulphur, lithium, barium, strontium, and iron 

occur in waters of this class. To these minor constituents the therapeutic value of mineral waters is commonly ascribed, but to considerations of that sort no attention can be paid here. The last analysis 

given, that of the Chloride of Iron Spa at Harrogate, is interesting 

as marking a transition to another group of chloride Avaters, in Avhich 

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 a

« Compt. Rend., vol. 103, p. 1205, 1886.
144 THE DATA OF GEOCHEMISTRY.

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: a

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, p. 915, 1896. A little H2S is 

present.

B. Well at Bowerman's mills, Whitby, Canada. Analysis by T. Sterry Hunt, Geology 

of Canada, p. 547, 1863. 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, p. 158, 1875.

D. Water from the Silver Islet mine, Lake Superior. Analysis, by F. D. Adams, Ann. 

Kept. Geol. Survey Canada, new ser., vol. 1, p. 17 M, 1885.

E. Water from the lower level of the Quincy mine, Hancock, Michigan. Analysis by 

G. Steiger, in the laboratory of the United States Geological Survey.

F. Water from boring on Kanab Creek, near Port Haney, British Columbia. Analysis 

by F. G. Wait, Ann. Kept. Geol. Survey Canada, vol. 5, ii, new ser., p. 22 R, 1890-91.

G. Boiling spring at Savu-Savu, Fiji. Analysis by A. Liversidge, Proc. Roy. Soc. New 

South Wales, vol. 14, p. 147, 1880. Part of the aluminum in this water is reported as 

Aids and part as A1203-

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

Br .............................

I...............................

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

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

TJ/-V

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

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

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

NH4 - -.-- -..- ................

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

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

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

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

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

Fe.jO«. .........................

Mn, Co'.........,.........:....

Si03 ...........................

Salinity, parts per million. . . . .

A.

62.31

.53

.01

.03

.27

18.35

1. 55 '

.04

.23

2.53

.02

.25

.02

100. 00 

309, 175

B.

64.43

.41

.09

16.17

13.68

5.22

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

.15

100. 00 

36,000

E.

63.55

, -01

.01

5.63

30.78

.01

.01

100. 00 

212, 300

F.

63.39

5.27

.42

30.89

(13

100. 00 

48,500

.G57.91

3.38

16.65

.93

18.34

.04

.43

.54

1 78

100. 00 

7,813

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, pp. 38, 39, 1886.

B. Hathorn Spring, Saratoga, New York. 6 Analysis, by Chandler, loc. cit.

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 CO2. The PO* in A and C amounts to 0.01 grain per gallon.

a 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, p. 46, 1894. Also one of water from the 

Freda well, Keweenaw Point, Michigan, by G. A. Konig, Rept. State Board Geol. Survey 

Michigan, 1903, p. 165. In the deep-seated waters around Lake Superior calcium chloride 

seems to be an nnportant constituent.

6 For recent analyses of the Hathorn and twelve other Saratoga waters, see .1. K. 

Haywood and B. H. Smith, Bull. No. 91, Bureau of Chemistry, U. S. Dept. Agric., 1905.
MINESAL WELLS AND SPRINGS. 145

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. v

E. Steamboat Springs, Nevada. Analysis by W. H. Melville, given by G. F. Decker in 

Mon. U. S. Geol. Survey, vol. 13, p. 349, 1888. Bicarbonates reduced to normal salts. 

The " trace " of iron represents 0.14 part per million.

F. Lansdowne well, Cheltenham, England. Analysis by T. E. Thorpe, Jour. Chem. 

Soc., vol. 65, p. 772, 1894. The "trace" of bromine is 0.3 part, and that of iron 0.1 part 

per million.

G. The Stanislawaquelle, near Karlsdorf,. Galicia. Analysis by Von Dunin-Wasowicz 

and J. I-Iorowitz, Chem. Centralbl., 1899, pt. 2, p. 491. Bicarbonates reduced to normal 

salts. The NO3 amounts to 0.02 part per million. One kilogram of this water contains 

2.157232 grams of free C0a and 0.10665 gram of organic matter.

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

Br .............................

I...............................

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

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

S ..............................

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

\TA

P(~> F04. ...........................

B407 . ..........................

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

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

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

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

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

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

Fe

Fe.,0.,. .........................

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

AloOa . .........................

As.............................

Sb...... .......................

Hg ............................

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

Salinity, parts per million.....

A.

42.00

1.13

.02

.08

18.59

27. 62

.78

.08

6.03

.09

3.41

.03

.14

100.00 

12, 022

B.

42. 42

.16

.02

19.28

27.29

.68

.16

5.69

.12

3.92

.07

.02

.17

100.00 

15,238

C.

41.95

.37

.02

trace

.04

18.66

28.84

1.83

. .07

5.04

.06

2.95

.07

.03

.07

100.00 

20, 315

D.

48.03

.05

.04

14.93

.49

.09

29.84

.41

3.75

2.19

.02

.06

.10

100. 00 

15,700

E.

35.00

4.58

.22

5.08

ra

8.88

30.35

3.79

.27

.25

.01

.01

.10

.02

11.41

100.00 

2,850

F.

38.01

20.89

4.22

32.80

.72

1.85

1.37

.14

100. 00 

8,870

G.

34.6

| .02

.82

19. 96

37.29

.53

.01

3.64

1.44

.82

.01

.17

.69

100.00 

7,639

SULPHATE ABATERS.

The sulphate waters, or the waters in which S04 is the principal 

negative ion, fall, like the chloride waters, into several groups, which 

shade one into another by imperceptible gradations. Among potable 

waters of this class, those \vhich 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. 

14399 Bull. 330 08 10
THE DATA OF GEOCHEMISTEY.

Analyses of sulphate waters.

A. Abilena well, 14 miles northwest of Abilene, Kansas, 130 feet deep. Analysis by 

E. II. S. Bailey, Univ. Geol. Survey Kansas, vol. 7, p. 166, 1902. The " traces " refer to 

4 parts NOs 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, p. 174, 1890. Contains 210 parts of free CO2 per million.

C. Cottage well, Cheltenham, England. Analysis by T. E. Thorpe, Jour. .Chem. Soc., 

vol. 65, p. 772, 1894. Contains 0.2 part of Fe per million.

t D. Bitter spring at Laa, Austria. Analysis by A. Kauer, Jahrb. K.-k. geol. Reichsaustalt, vol. 20, p. 118, 1870. Contains free CO2.

E. Water from Cruzy, He"rault, France. Analysis published by Braconnier, Aim. mines, 

8th ser., vol. 7, p. 143, 1885. 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, p. 309, 1886. 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. .......................................

SO.,...................................:...

C03 ...........................:..........

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

po4 ......................................

As........................................

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

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

Li. ................................. ......'

NH4 ........ ..............................

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

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

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

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

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

Fe". .....................................

FeoO3 . . ....................................

AliA,.. ...................................

Al.................................. '.'.....

Cu .......................................

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

A.

0.48

66.28

.60

30.46

1.08

.67

.41

.02

100. 00

7d 733

B.

2.62

72.56

11.23

.22

.53

12. 79

trace

.05

' 100.00 

60,584

C.

6.56

67.42

6.48

.02

13.51

.48

.01

8.33

7.03

.16

100. 00

K (VI Q

]).

0.57

69.87

4.75

2.99

.35

.22

7.63

13.18

1 .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

1.50

.30

23.55

.05

3.07

1 m - ( ' 01

.03

1.55

100. 00 

1,948

G. Spring at Srebrenica, Bosnia. Analysis by E. Ludwig," Min. pet. Mitth., vol. 11, 

.p. 303, 1889-90. 1.37 per cent of free H2SO4 has been here added to the figure for the 

S04 radicle. A little organic matter (11.2 parts per million) is also present.

I-I. Alum well, Versailles, Missouri. Analysis .by P. Schweitzer, Geol. Survey Missouri, vol. 3, p. 131, 1892.

I. Water from Roncegno, southerti Tyrol. Analysis by M. Glaser and W. Kalmann, 

Ber. Deutsch. chem. Gesell., vol. 21, p. 2879, 1888.

J. Spring on Shoal Creek, 4i miles west of Joplin, Missouri. Analysis by W. F. Hillebcand, Bull. U. S. Geol. Survey No. 113, p; 49, 1893. Total CO2 , free and combined, 

120.5 parts per million. A trace of lead is also reported.

" On p. 308 of the same volume Ludwig gives an analysis of an acid water rich in 

aluminum sulphate from Biidcis, Transylvania. Other papers in the volume give a number 

of important analyses of springs in Bosnia and Transylvania. Some waters containing 

'unusual amounts of strontium are mentioned in Kept. State Board Geol. Survey Michigan, 1905, p. 555.
MINERAL WELLS AND SPRINGS. 147

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

so..............................................................

CO;, ...........................................................

P04 . ..........................................................

H.tAsO.| ........................................................

AsO, ..........................................................

Nil ...............:............................................

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

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

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

\flr

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

Fe" .....................:.....................................

Fe'" ..........................................................

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

Co.............................................................

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

CA. ....... ........... ..........................................

Zn.... .........................................................

cu .......................................:....................

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

G.

0.48

65.33

.41

.31

.32

3.00

1.48

J2

24. 98

1.21

.80

.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

L

0.03

70.93

.23

1.93

1. 25

.23

7.08

.93

.78

.03

11.09

3.0!)

.17

.41

.06

.15

1.61.

100. 00 

8, 150

,}.

0.48

52. 7fi

8.00

.67

.46

11.32

.71

.42

.11

.08

.10

22.31

.04

2. 54

100.00 

5-10

The Roncegno water evidently derives its saline constituents from 

metallic sulphides, apparently, in great part, from arsenical pyrites. 

Arsenical Avaters are not uncommon, and some of them contain enough 

arsenic to be poisonous. The Avater from Shoal Creek represents the 

oxidation of zinc blende, together Avith some reaction upon the adjacent limestones, from Avhich its calcium and carbonic ions Avere obtained. It is essentially the same thing as a mine Avater,- although it 

is not derived from any artificial opening. For comparison, three 

analyses of mine Avaters. carried out in the laboratory of the Geological Survey, are appended. Two of them are zinc Avaters; the 

third is a strong solution of copper sulphate. Such Avaters play an 

important part in the leaching and reprecipitation of ores, and will be 

more fully considered later.
148 THE DATA OF GEOCHEMISTRY.

Analyses of mine waters.

A, B. Two mine waters from the Missouri zinc region," analyzed by I-I. N. Stokes.

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.Q Co, 

6.8 K, and 1.5 PO4.

ci...... ...................................................................

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

po4 . .......---......-. ...................................................

As04 .....................................................................

^a........ ...............................................................

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

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

C&. ............................................. .........................

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

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

Fe".... ..................................................................

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

Co.......................................................................

Zn...................... ..............................................:..

Cu......... .............,...........:..........-..-.............-........

Cd........ ...............................................................

Al ....................................................................... <5in

A.

0.16

64.47

1.14 -.10

trace

14.38

1.36

.08

6.49

10.74

.02

.20

.86

100. 00

| 4, 232

B.

0.03

' 63. 26

.50

3.55

.26

.02

4.88

24.80

.04

09

1.46

1.11

100. 00 

9,754

 C.

0.01

60.29

.04

.26

.13

.01

.04

.87

38.72

 .07

.06

100. 00 

117,850

" Two similar waters from the same region were analyzed by C. I'. Williams, Am. 

Chemist, vol. 7, p. 246, 1877.

Two other examples of intermediate waters, containing both- sulphates and chlorides, but with the former in excess, may be cited 

here. Both are B from Indiana, and the analyses are by W. A. Noyes.

Analyses of sulphato-chloride 'waters.

A. King's mineral spring, near Dallas. Twenty-sixth Ann. Rep,t. Indiana Dept. Geology, 

p. 32, 1901.° Contains traces of Al, Fe, Ba, Sr, Li, Mu, Ni, Zn, Br, PO4 ; and B4.07 .

B. West Baden Spring. Op. cit, p. 109. Contains traces of Al, Fe, Ba, Sr, Li, Br, I, 

P04, and B407. Also 32.5 parts of I-L.S per million of water.

ci ..................................................................................

so......... .........................................................................

co3 .. :..................... .........................................................

Na......... ................:.............................................. '.........

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

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

Mg....... ................ ..................................... ..........:...........

SiOj..... ...........................................................................

11.10

59. 68

1.67

13. 89

.49

2 91

10.19

.07

100. 00 

15, 682

 18.19

46.66

4.11

11. 72 .78'

13. 16

^ 91

.17

100. 00 

4.417

B.-

" This volum§ contains an elaborate report upon the mineral -waters of Indiana, in 

which many other analyses are cited.
MINERAL WELLS AND SPRINGS. 149

CARBONATE WATERS.

The carbonate waters, those in which CO., or HCO3 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 Avaters 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, 

CaCO;( and MgCO3 are deposited, while the ferrous bicarbonate is 

broken up, and insoluble Fe2 0;i , 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:

Analyses of carbonate waters.

 A. McClelland well, Cass County, Missouri. Analysis hy P. Schweitzer, Geol. Survey 

Missouri, vol. 3, p. 181, 1892.

B. Artesian water, La Junta, Colorado. Well ?>8G feet deep. Analysis by W. F. HilIcbrand, in the laboratory of the United States Geological Survey.

C. Ojo Callente, near Taos, New Mexico. Analysis by Hillebrand, Bull. U. S. Geol. 

Survey No. 113, p. 114, 1893. Traces of As, N0;1 . Ba, NH4 , anfl possibly I, were found,

D. The Grande-Grille, Vichy. France.". Analysis by J. Bouquet, Ann. chim. phys., 

3d ser., vol. 42, p. 304, 1854. Analyses of other Vichy waters and their sediments are 

given in this memoir. '

E: -Spring at Bikutaia, I'uriri, district of Auckland, New Zealand. Analysis hy W. 

Skey, Trans. New Zealand Inst., vol. 10, p. 423, 1877.

F. Excelsior Springs, Missouri. Analysis hy W. P. Mason, Chem. News, vol. 61, p. 

123, 1890, 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. llept. Geol. Survey Canada 1900, p. 49 R. This water deposits hydromagnesite and calcareous tufa.

l-r. Wilhelmsquelle, Kiirlsbrunn, Austrian Silesia. Analysis hy E. Ludwig, Min. pet. 

Mitth.,' vol. 4, p. 182, 1882.

"According to De Gouyenain (Compt. Rend., vol. 76, p. 1063, 1873), Vichy water contalus 7.6 parts of fluorine per million. In the water of Bourbon-1'Archambault 2.68 

parts of fluorine were found. For other examples of water containing fluorine see .T. C. 

Gil, Mem. Acad. Barcelona, vol. 1. p. 420, 1896; A. F. de Silva and A. d'Aguiar, Bull. 

Soc. chim., 3d ser., vol. 21, p. 887, 1899 ; C. Lepierre, Compt. Rend., vol. 128, p. 1289, 

1899; .T. Casares, Zeitschr. anal. Chemie, vol. 34, p. 546, 1895; vol. 44, p. 729, 1905, and 

P. Carles, Compt. Rend., vol. 144, p. 37, 1907. Carles rarely failed to detect fluo/ine 

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.
150 THE DATA OP GEOCHEMISTRY. 

I. PARTS PER MILLION OF WATER.

Cl........ ................... I............................

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

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

K:....... ....................

CO, .........................

HCO:1 . .......................

P04 .........................

As04 . .......................

^Oj... ......................

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

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

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

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

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

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

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

FeoO..,.. !.....................

AloO,--. .....................

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

A.

94

88

1

581

4

2

2,009

B.

66.9

71.1

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

47.9

5, 305. 8

1, 897, 1

31.6

100.6

80.2

7, 673. 1

F.

11. 98

2. 68

9.51

3.65

145. 10

15.63

4.50

11.31

2.10

12.00

489. 00

ft.

1.5

60.2

6, 339. 1

51.9

12.0

116. 8

1,352.3

6.7

6.5

82.5

7, 829. 5

H.

 1.09

G. 48

405. IS

.54

5.24

1.76

66. 27

18.85

.05

46. 57

.30

69. 36

621. 69

IT. PERCENTAGE OF TOTAL SOLIDS, ALL CARBONATES NORMAL.

Cl. ................ ......... I............................

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

SO4 ..........................

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

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

P04 .... .....................

As04 ........................

B4 07 ........................

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

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

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

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

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

MR......................'....

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

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

FejO,. .................... ...

Al,0;i - .......................

SiOo., ........ ....... . ..

6. 63

6.21 '.06

41.07

.30

19

OK

loo. oo

4.01

4.26

47.45

40.09

.38

.27

1 K

.20

3.05

100. 00

8.85

19

5.77

41 91

.01

.16

38.08

1.20

.12

.87

.05

.41

.06

.02

0 Qfi

100. 00

6.17

45.57

1.52

.04

35.27

2.88

2.29

.04

1.11

.04

1 Q9

100. 00

3.84

.98

CO f\Q

3S 3Q

.64

2.04

1 22

trare

,

on

100. 00

2.42

.54

55 92

1 92

7Q

29. 28

3 1 ^

.91

2.28

.43

2 *** 42

100. 00

0.03

1.31

67.56

1.13

.26

9 ^4

oc no

.21

.14

1.79

100. 00

0.28

1. 68

38. 72

.14

tr&CG

1.36'

.46

17.18

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.

Analyses of waters of mixed types.

A. The Virginia Plot Springs, Virginia. Average of six springs, analyzed by F. W. 

Clarke, Bull. TJ. S. Geol. Survey No. 9, p. 33, 1884.

B. The Life well, Fairhaven Springs^ Missouri. Analysis by P. Schweitzer, Geol. Survey Missouri, vol. 3, p. 174, 1892.

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 .7. E. 

Whitfield, Bull. U. S. Geol. Survey No. 47, p. 36, 1888. Free CO,, 354 parts per million.
MINERAL WELLS AND SPRINGS.

E. Orange Spring, Yellowstone National Park. Analysis by Gooch and Whitfield, op. 

cit., p. 38. Free C0«, 92 parts per million.

F. Konigsquellc, Bad Elster, Saxony. Analysis by It. Flechsig, cited by A. Goldberg, 

 15. Ber. Natur. Gesell. Chemnitz, pp. 74, 108, 1904. This memoir is a monograph on the 

mineral waters of Saxony, and contains many analyses. Bicarbonat.es reduced to normal 

salts. Free C02 is also present.

G.-The Sprudel, Carlsbad, Bohemia. Analysis by F. Ragsky, cited by Koth, Allgem. 

chem. Geol., vol. 1, p. 509. .Contains 0.7004 gram free and half-combined C02 per kilogram. Also traces of Br, I, Li, B, Rb, and Cs.

II. Chalybeate water, Mittagong, New South Wales. Analysis by J. C. l-I. Mingaye, 

Proc. Roy. Soc. New South Wales, vol. 20, p. 73, 1892. A very unusual water. In the 

same memoir Mingaye gives many other analyses of Australian spring, artesian, and 

well waters.

01..............................'.....

Br...................................

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

SO....................................

co:, .................................

P04 .. ...............................

AsO< ................................

B4 07 .. ...............................

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

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

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

NH.j.................................

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

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

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

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

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

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

A12O.,. ...... .........................

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

A.

0.64

21. 73

1.81

2.04

5.82

.58

4.01

100.00 

563

B.

0.06

51.54

5

00

16. S6

6.39

.79

2.19

100.00 

1,670

C.

18.02

33.22

.79

5.26

2.23

.07

.04

.35

100.00 

3,008

D.

10.09

30.44

.26

1.46

7.50

2.95

.13

.03

4.21

54

2.98

100. 00 

1,732

:K.

10.07

32.80

7 65

'3.78

.10

17.60

4.09

1°.

3.12

100. 00 

1,612

F.

20. 36

31.47

.45

.23

.44

.19

.59

1.40

100. 00 

4,991

G.

11.52

.03

31.19

.01

32.49

1.35

2.23

.01 .65-

.01

.02

1.34

100.00 

5,431

H.

27. 34

7.13

8.96

4.25

5.89

15. 85

100.00 

225

SLLICEOTJS 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 

f eldspathic rocks are likely to contain silica as a chief inorganic constituent, but the absolute amount of it is generally small. In volcanic 

waters, on the other hand, and especially in geyser waters, the silica 

may reach half a gram to the liter, and sometimes even more.'1 It is 

usually reported as Si(X; although in some cases, when the ordinary 

acid radicles are insufficient to satisfy the bases, ^it becomes necessary 

to assume the existence of silicates, although their precise nature is 

unknown. For such waters it is convenient to report this saline silica 

in the form of the metasilicic radicle SiO;! , the dried residue being 

supposed to contain the sodium salt Na2 SiO3 ; but this is hardly 

more than a convenient device for evading a recognized uncertainty. 

In solution, according to L. Kahlenberg and A. T. Lincoln,6 sodium 

metasilicate is hydrolyzed into colloidal silica and sodium hydroxide;

0 For example, the Opal Spring, in the Yellowstone National Park, carries 0.7020 

gram of silica per kilogram of water.

>> Jour. Physical Chern., vol. 2, p. 77, 1898.
152 THE DATA OF GEOCHEMISTRY.

and this conclusion was also reached by F. Kohlrausch ° 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 

quite dilute:

Analyses of silicic waters not of volcanic origin.

A. Big Iron Spring, Hot Springs of Arkansas." Analysis by .T. 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, HC03 has been recalculated into the proper quantity of C03 cor-. 

responding to the normal salts.

B. Cascade Spring, Olette, eastern Pyrenees. One of six analyses by E. Willm, Compt. 

Rend., vol. 104, p. 1178, 1887. Temperature 79.4° C. In this water, which might also 

be classed as a sulphur water, the radicle S20a 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. Rept. Indiana Dept. Geology, pp. 76, 81, 86, 1901.

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

Br, I........................... ................................. . ...............

S0«.. ...............................................................................

SjO3 . .....................:..........................................................

S.... ................................................. .....

coa ..... .......................................................:.......:............

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

P04.................................. ...............................................

BOs.......... ......................................................................

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

K.... .................... . . ................................;..................

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

NIL, ................................................................................

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

Ba, Sr..............................................................................

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

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

Fe, Al ...........................................;...'...............................

8102................................................................................

A.

1.27

3.93

41.47

.23

.03

.64

2.38

.80

.03

23.54

2.56

.17

.10

22.85

100.00 

6199

B.

4.38

7.28

4.81

3

QB

12 14

9fi no

1.01

38 91

100. 00 

244

" On the radioactivity of the Arkansas Hot Springs, see B. B. Boltwood, Am. Jour. 

Sci., 4th ser., vol. 20, p. 128, 1905.

6 284.8 in the original, where bicarbonates are included. In that statement HCO3 

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.

"Zeitschr. physikal. Chemie, vol. 12, p. 773, 1893.
MINERAL WELLS AND SPRINGS. 153

Analyses of geyser waters.

C. Coral- Spring, Norris Basin, Ycllowstone 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. Whitfield, 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, p. 40. 

1847.

I. Te Tarata, Rotorua, New Zealand. The water which formed the white terrace o£ 

Rntomahana. A large excess of silica over bases, represented as SiO:i.

.T. 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, p. 423, 

1877. Thirteen other analyses are given in this memoir."

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

Br........................... ........

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

S...... ..............................

C08 . ................................

po4 ........... .......................

AsO, ................................ BA....... ..........................

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

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

NH 4 .... .............................

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

Mg...... ............ ............A..

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

Fe ..............:...................

Fes03 ...............................

A1 20;) ---- ................ .:.. ........

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

SiO». ................................

SiOs ............. ....................

C.

36. 61

1.84

.15

.08

2.24

21.44

4.45

.22

.02

.39

.08

 1\ 79

100. 00 

1,830

D.

14.93

.29

2.38

.15.65

4.89

.13

1.42

QQ

Q1 OO

100. 00

 808

E. . 

29.22

12. 15

' 2. 05

| 5.80

50.78

100.00 

473

F.

 31.64

.25

1.30

8.78

.24

1 19

26.42

1.93

.40

.11

.04

.12

27.58

100. 00 

1,388

G.

20.91

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. CO

33. 94

1.01

.38

.09

.20

.01

33. 95

100. 00 

2,064

J.

37. 52

4.96

24.22

' .36

2.59

.19

trace

.35

29. 81

100.00 

2,735

0 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.

NITRATE, PHOSPHATE, AND BOBATE WATERS.

Although waters containing small quantities of nitrates, berates,- 

or phosphates are not uncommon, waters in which these compounds 

are conspicuous are rare. Melville's analysis of Steamboat Springs 

has already been cited, arid the salts from that -water contain nearly 

9 per cent of the radicle B4O7 , corresponding to about 11.5 per cent 

of anhydrous borax." Nitrates are usually regarded as evidence 

of pollution in waters, but they are not necessarily of that character. 

In arid regions, where nitrification goes on rapidly, nitrates may 

occur in considerable amounts; some of the underground waters of

" Boric acid in natural waters has been discussed by L. Dieulafait in Compt. Rend., 

vol. 93, p. 224, 1881; vol. 94, p. 1352, 1882 ; and vol. 100, pp. 1017, 1240, 1885. According to L. Kahlenberg and Ot Scbreinerj Zeitschr. physikal. Chemie, vol. 20, p. 547, 1896, 

the group B4 07 is not the true ion of the borates. It is a convenient expression, however, 

for the negative radicle of borax.
154 THE DATA OF GEOCHEMISTBY.

Arizona contain as high as 160 parts per million of nitrogen in this 

form.a 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, p. 99, 1865. 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. 156), 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. TJ. S. Geol. Survey, vol. 13, p. 259, 1888. Some 

organic matter, a little H2S, and a considerable amount of C02 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, p. 354, 1888. 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, p. 192, 1890. 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, p. 265, 1886. For a corroborative analysis see M. Greshoff, idem, fol. 16, p. 354, 

1897. 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. 1'

01........................................ I.........................................

sot ........ ...............................

C03 ...... ................................ - N03 ..... .................................

 BtO,... ...................................

V04 . .....................................

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

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

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

NH< ......................................

Ca. .......................... ..^... ........

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

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

Fe".......... .I.... .......................

Fe'". .....................................

MtO*.... .................................

SiOj........ ..............................

A.

16.49

.03

, trace

21.96

25. 6i

24.99

trace

7.88

trace

trace

.40

10. 000 

c5,343

' B.

13.57

.32

22.38

27.98

33.97

.48

- .05

 .41

.11

70

100. 00 

5,096

C. "

14.39

10.06

4.73

40.09

28.49

.84

.02

.44

.03

. .01

90

100. 00 

4,632

D.

5.11

7.74

19.46

'6.33

22.41

3.32

trace

30.38

1.21

4.04

100. 00 

490

E.

5.45

27.87

2.58

36.09

3.53

.68

15.93

5.17

OA

.06

o rfi

100. 00 

1, 163

F.

16. 44

14.04

12.78

24.62

i'2. 66

6.67

 8.70

2.70

JOO.OO

3

AK.Z.

o See W. W. Skinner, Bull. No. 46, Univ. Arizona Agric. Exper. Sta., 1903.

''The mineral water of Cherrydale, Virginia, is also reported to be rich in nitrates. 

See analysis by J. K. Haywood and B. H. Smith, of a commercial bottled sample, in 

Bull. No. 91, Bureau of Chemistry, U. S. Dept, Agric., p. 54, 1905.

c Reckoned with normal carbonates. With bicarbonates the salinity becomes 6,556 

parts per million.
MINERAL WELLS AND SPRINGS. 155

ACID WATERS.

The last group of waters that we have to consider are those which 

contain free acids, sulphuric or hydrochloric. They may be classified in two divisions first, acid waters derived from sedimentary 

rocks, their acidity being probably due to the oxidation of pyrites or 

other sulphides; second, waters of volcanic origin. Under the first 

heading the four analyses given below may be cited. In these analyses it seems best to state the free acids as such and not in the form 

of ions, and to give, instead of the normal " salinity," the total 

inorganic impurity in parts per million."

Analyses of acid luaters from sedimentary rocks.

A. The Tuscarora sour spring, 0 miles south of Brnntford, Canada. Analysis by 

T. Sterry Hunt, Geol. Survey Canada, 1863, p. 545.

B. Oak Orchard Spring, Alabama, Genesee County, New York. Analysis by W. .T. Craw, 

Am. .Tour. Sci., 2d ser., vol. 9, p. 449, 1850. The free acid is stated in the original as . SO3 ; it is here recalculated into H2S04.

C. Spring 9 miles northwest of Jonesville, Lee County, Virginia. Analysis by L. E. 

Smoot, Am. Chem. .Tour., vol. 19, p. 234, 1897. Acidity low.

D. Rockbridge Alum Spring, Virginia. Analysis by M. B. Hardin, Am. Chemist, vol. 4, 

p. 247, 1873-74. This water and that analyzed by Smoot might be equally well put in 

the ordinary sulphate group with other " alum " springs.

HoS04 , free....................................................

HN03, free ....................................................

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

DA

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

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

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

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

Fe"....... ....................................................

Fe'"............... .............................................

Mn ...............................'.............................

Ni.............................. ......................:........

Co.............................................................

Zn ............................................................

Cu ............................................................

Al................. I...........................................

SiO........................................ :...... .............

A.

69.62

22.11

.26

.44

 3.70

.50

2.17

i.io

100.00 

6, 161

B.

47.87

.43

36.28

.87

.71

6.39

2.06

3.06

1.00

1 ^

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

32

68. 21

.22

.11 .01'

.38

1. 11

1.19

.69

.07

.05

.08

11.08

7.11

100. 00 

464

" 4,085 when the free acid is reckoned us SOn.

Among volcanic waters acidity is much more common, and many 

examples of it are known. The following analyses are among the 

most typical, and are stated in the normal percentage form:

Analyses of acid waters of volcanic origin.

A. Devil's Inkpot, Yellowstone National Park. Analysis by F. A. Gooch.and J. E. Whitfield, Bull. TJ. S. Geol. Survey No. 47, p. 80, 1888. Acidity slight. This water is unique 

on account of its high proportion of ammonium salts. It contains NtL. equivalent to 2.8

a In Bull. TJ. S. Geol. Survey No. 315, p. 489, 1907, W. T. Lee cites an analysis by 

W. M. Barr of a strongly acid water from the sulphur beds of Cove Creek, Utah.
156 THE DATA OF GEOCHEMISTRY.

grams of ammonium sulphate per liter, or about S3 per cent of the total impurity." Contains also 65 .parts of free C02 and 5.parts of H2S per million.

B. Rio Vinagre, Colombia. Analysis by J. B. Boussingault, Ann. chim. phys., 5th ser., 

vol. 2, p. 80, 1874. " Free SO3 recalculated into H2SO4 .

C. Hot Spring, Paramo de Ruiz, Colombia. Analysis by H. Lewy, cited by Boussingault, op. cit., p. 91. Free SOa recalculated into H2S04.

D. Solfatara at Pozzuoli, Italy. Analysis by S. De Luca, Compt. Rend., vol. 70, p: 

408, 1870.

E. Brook Siingi Pait, from crater of Idjfin volcano, Java. Analysis by F. A. FHickiger, 

Jahresb. Chemie, 1862, p. 820. Acid waters are not uncommon in Java.

F. Hot Lake, White Island, Bay of Plenty, New Zealand. Analysis by C. Du Ponleil, 

Ann. Chem. Pharm., vol. 96, p. 193, 1S55. Practically a 10 per cent solution of hydro-' 

chloric acid.

G. Probably the same water as that of F. Analysis by W. Skey, Trans. New Zealand 

Inst, vol. 10, p. 423, 1877.

H. Cameron's Bath, Rotoru'a geyser district, New Zealand. Analysis by Skey, loc. cit. 

Contains 6 parts per million of H2S. - - '

I. Yellow lake or hot pool, crater of Taal volcano, Luzon, Philippine Islands.

J. Green lake or pool, 0 crater of Taal volcano. Analyses I and J by J. Centeno, Estudio geologico del volcan de Taal, Madrid, 1885. Obscurely stated. Recalculated on the 

assumption that " fosfato s6dico " means NasPO.4, and that sulphuric acid means HoS04 

and not SOa. The free acid, however, should probably be' all hydrochloric, with no sulphuric at all. lu this matter I have simply followed the author. Compare citation by 

G. F. Becker, Twenty-first Ann. Rept. U. S. Geol. Survey, pt. 3, p. 49, 1901.

 HCl.free.. .........

H»S04 , free.........

H3B03 . .............

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

$04 .. ................

r>y-\

B407 ...............

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

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

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

NH4 . ...............

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

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

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

Fe". ............... Fe'"

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

As..................

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

Total impurity, 

parts per milA.

0.18

1.29

2.73

67.66

.73-

.24

.01

22.85

1.18

.36

.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 

d 2, 969

C.

5.50

44.17

4 gg

31. 71

3.22

1.21

2.31

1.53

3.18

2.21

100. 00 

e 8, 296

D.

16.62

.34

55.08

.57

.58

2.91

.55

3.47

7.16

12. 72

100.00

/2,477

E.

43.96

14 95

26.96

1.32

.39

2.05

.94

4.66

4.44

.33

100.00 

18, 060

F.

65.42

ii.69

10.64

1 91

.75

.59

2.30

.34

6.98

.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. CO

59.11

20.21

trfliCC

8.35

.32

.47

.22

.33

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

7Q

20.75

3.03

.22

1.02

1.03

5.55

1.23

100. 00 

60,023

" As an ammoniacal water tins may be compared with the borate water from Cles, 

Lake. California, previously cited.

6 Boussingault also gived analyses of several saline waters from the same region. C 

p. 81 he estimates that Rio Vinagre at Purace carries, each day, 46.873 kilograms ot 

HoSQi and 42,150 kilograms of HC1. These figures correspond to 17,000 and 15,000 

metric tons per annum.

c For recent analyses of these Taal waters, see R. F. Bacon, Philiopine Jour. Sci., vol. 

1, p. 433, 1906; vol. .2, p. 115, 1907. Unfortunately, these analyses, which corroborate 

Ceuteno'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, pp. 136-153, San Francisco,. 1892. Some of these waters 

are strongly acid. ' .

« 2,959 with free SOa instead of H<,S04 .

8 7.623 with free S0:i instead of HoSO4 . '

' 2,936 with free S03 instead of H2SO4 .

Still another acid water, from the crater of Popocatepetl, was 

partially analyzed by J. Lefort." It contained 11.009 grams of hydrochloric acid and 3.643 of sulphuric acid in 1,000 parts, together with

Compt. Rend., vol. 56, p. 909, 1863.
MINERAL WELLS AND SPRINGS. 157

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 description. The 

total dissolved matter amounted to 17,512 parts per million.

J. B. Boussingault," in his memoir on the acid waters of the Colombian Andes, discusses at some length the question of their origin. 

He shows that hydrochloric acid may be generated by the action of 

steam upon a mixture of chlorides and silica, and also that hot gaseous hydrochloric acid will liberate sulphuric acid from sulphates. 

Both of these reactions may take place in volcanoes. Sulphuric acid 

may also be formed by volcanic heat, sulphur, either free or derived 

from sulphides, first burning to S02 , which afterwards, in presence 

of moisture, oxidizes to H.,S04 . 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.

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 positiA'e ion sodium. 

B. Principal positive ion calcium. 

0. Waters rich in magnesium.

II. Sulphate.waters. Principal negative ion SO4 . 

, f A. Principal positive ion sodium. 

B. Principal positive ion calcium.

 t' C.. Principal positive ion magnesium. \ 

D. Waters rich in iron or aluminum. -v E. Waters containing heavy metals, such as zinc. 

Sulphate-chloride waters, with S04 and Cl both ab'undant. 

Curbonate waters. Principal negative ion CO3 or HGO3 . 

A. Principal positive ion sodium. " 

B. Principal positive ion calcium. !, 

C. Chalybeate waters. J'

V. Sulphate-carbonate waters. SO* and CO3 both abundant.

VI. Chloro-carbonate waters. Cl and CO3 both abundant.

a Ann. chim. phys., 5th ser., vol. 2, p. 76, 1874.
158 THE '-DATA OF GEOCHEMISTRY.,

VII. Triple waters, containing chlorides, sulphates, and carbonates in equally 

notable amounts.

VIII. Siliceous waters. Rich in Si02 .

I.. Borate waters. Principal negative radicle B4O7 . 

X. Nitrate waters. Principal negative ion NO3 .

XI. Phosphate waters. Principal negative ion P04 .

XII. Acid waters. Contain free acids. 

A. Acid chiefly sulphuric. 

B. Acid chiefly hydrochloric.

This classification is sufficient for all-practical purposes, although 

it might be subdivided still further in order to cover certain exceptional cases, as, for example, the feebly acid ammonium sulphate 

.water of the Devil's Inkpot. Many waters are obviously intermediate in character, like the brines containing both calcium and 

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. i

CHANGES EN 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
MINERAL WELLS AND SPRINGS. 159

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. Bechamp rt 

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.

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: . . CaH2CoO0 =CaCO:,+HaO-j-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, p. 323, 1904.

B. Travertine, near Pulsating Geyser, Mammoth Hot Springs. Analysis by .T. E. 

Wliitfleld, Bull. U. S. Geol. Survey No. 228, p. 323, 1904. Other analyses of calcareous 

deposits are given in the same publication. 6

C. Lithoid tufa, Lahontan basin, Nevada. One of three analyses by O. D. Alien, 

cited by I. C. Russell, Mon. U. S. Geol. Survey, vol. 11, p. 203, 1885.

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, p. 502, 1878.

"Ann. chim. phys., 4th ser., vol. 16, p. 202, 1869. See also a recent physicochemical 

discussion by F. Auerbach, Zeitschr. physikal. Chemie, vol. 49, p. 217, 1904. 

6 See also W, H. Weed, Ninth Ann, Rept. U. S. Geol. Survey, p. 619, 1889.
160 THE DATA OF GEOCHEMISTRY.

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

AU>3 .-..............................................:..-.-....

FegOa.........................................................

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

MgO.........:....................................:...........

KoO...........................................................

No/)..................... .....................................

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

NaCl.......... ................................................

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

sos ............ ................................................

cos ...........................................................

PoOs............. ................. IL.O...... ................... ....::.:::::::::::..::::::::::::::

A..

0.09

} »

55.37

.35

.04

.10

.44

43.11

.32

.17

100. 10

B.

0.05

| . 

52.46

90

.71

..33

1.45

1.82

40.88

1.02

.30

100.03

0.

1.70

f .»

50.48

2.88

41.85

.30

2.07

99.53

D.

8.40

i QI

46.38

3 ivl

.22

.48

38. 20

1.71

100.24

Analyses of several European tufas are given by Koth.a and they 

exhibit many variations in composition. Ten calcareous deposits 

from the springs of Vichy were analyzed by J. Bouquet,6 who found 

strontium and arsenic in them. The arsenic ranged from a trace to 

1.16 per cent of As*2 05 . In the Carlsbad " Sprud'elstein " Blum and 

Leddin ° 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 a 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. 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. 

Silica and ferric hydroxide are among the most common contaminations.

OCHEROUS DEPOSITS.

When ferrous ions are present in a carbonate water, loss of carbonic

acid is followed or accompanied by oxidation, and the precipitated 

material is an ocherous ferric hydroxide. Around chalybeate springs 

.these deposits of iron rust are always noticeable. Manganese hydroxide may be deposited in a similar way. 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

0 Allgem. chem. Geol., vol. 1, p. 539.

6 Ann. chim. phys., 3d ser., vol. 42, p. .332, 1854. For later analyses of Vicby deposits, 

see C. Girard and P. Bordas, Compt. Rend., vol. 132, p. 1423, 1901.

r- Ann. Chem. Fharm., vol. 73, p. 217, 1850.

* 1'roc. Colorado Scl. Soc., vol. 8, pp. 1-30, 1905. 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, p. 

506, 1901. Alkaline bicarbonates, with an excess of COL-, 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.
MINERAL WELLS AND SPRINGS. 161

mixture may occur. Sometimes when sulphates have been reduced 

by organic matter sulphides of iron are deposited, and a number of 

examples of'this kind are cited by Roth.a The following analyses 

will illustrate the usual character of these sediments:

Analyses of oclierous deposits.

A. Deposit from Drlburg, Germany. Analysis by F. J. H. Ludwig, .Tahresb. Chemie, 

1847-48, p. 1012.

B. Deposit from Nauheim, Germany. Analysis by Bwald, Jahresb.' Chemie, 1847-48, 

p. 1012.

C. Deposit from Enclos des C61estins, Vichy. One of four analyses by T. Bouquet, 

Ann. chim. phys., 3d ser., vol. ¥2, p. 336, 1854. 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, Yellovvstone National Park. Analysis by J. E. Whitfteld in the laboratory of the United States Geological Survey."

A12 03 . .........................................................

CaO ............................:.................-............

CaC03 . ........................................................

MgCOs................ ........................................

S08 .. ..........................................................

P30.; ............................................................

As203 . ..........................................................

AsaOs ..........................................................

Soluble Si02 . ..................................................

HsO ................................... ^. ......................

A.

57. 303

6.683

.543

.063

23.333

.542

5.388

(>. 145

100.000

B.

49! 86

.40

' 20.81

9 10

2.81

23. 53

100.00

C.

47.40

10.85

6.03

6 96

1.04

| 25. 72

9 fif!

100. 06

D.

63.03

.08

8.35

1.37

} 26. 94

99.77

" For iin analysis of water from Death Gulch, see G. B. Frankforter, .Tour. Am. Chem. 

Soc., vol. 28, p. 714, 1006.

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 they are all formed by deposition from chalybeate solutions. Their consideration, however, does 

not belong in this chapter.

SILICEOUS DEPOSITS.

Siliceous deposits are formed by all waters containing silica, but 

are commonly so small as to be inconspicuous. The silica then appears, as in the preceding tables of analyses, as an impurity in something else. From hot springs, however, which often contain silica 

in large quantities, great bodies of sinter are produced, and this has 

a composition approaching that of opal. Mineralogically, siliceous 

sinter is classed as a variety of opal, for it consists mainly of hydrated silica with variable impurities. According to W. H. Weed,7' 

who has studied the formation of sinters in the Yellowstone Park,

"Allgem. chem. Geol., vol. 1, pp. 599, 600. 

"Am. .Tour. Sci., 3d ser., vol. 37, p. 351, 1889.

14399 Bull. 330 OS 11
162 THE DATA OF GEOCHEMISTRY.

the deposit may be due either to relief of pressure, to cooling, to chemical reactions between different waters, to simple evaporation, or to 

the action of algae. In the last case the silica forms a gelatinous layer 

upon the algous growths, and this, after the death of the algae, gradually hardens to sinter. The subjoined analyses (A to E) of Yellow - 

stone Park sinters are selected from among fifteen which were made 

by J. E. Whitfield in the laboratory of the United States Geological 

Survey.0

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, p. 826, 1877.

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

A12 03 . ....................................

Fej03 .......... ....:......................

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

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

MgO..... .......................... ......I

K2O......................................

Na2 0 .....................................

NaCl.....................................

R»0a. ......................... :.......,..

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

SO3 ..... ..................................

S... ......................................

A.

94.40

} .79

.

5.02

100.21

B.

93.60

1.06

.50

trace

4.71

99.87

C. 

89.54

2,12

1.71

.30

1.12

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 no

.2045

100. 36

F.

92.67

| .80 '

.14

.05

.18

.75

1 A^

100. 04

0 Loss on ignition.

At Steamboat Springs G. F. Becker 6 found the deposits to contain

also sulphides of antimony, arsenic, lead, copper,'and mercury, ferric 

hydroxide, gold, silver, and traces of zinc, manganese, cobalt, and 

nickel.

The following analyses represent sinters from foreign localities: c

Analyses of sinters from foreign localities.

G. Geyserite, Iceland. Analysis by A. A. Damour, Bull. Soc. g(5ol. France, 2d. ser., vol. 

5, p. 160, 1847-48.

H. Deposits from the Scribla spring, Icelandic geysers. Analysis by C. Bickell, Ann. 

Chem. Pharm., vol. 70, p. 293, 1849. 

I. Sinter from the hot springs of Taupo, New Zealand. Analysis by .1. W. Mallet, 

Phil. Mag., 4th ser., vol. 5, p. 285, 1853.

J. Sinter from geysers of Rotorua, New Zealand. Analysis by J. E. Whitfield, discussed by W. H. Weed, Ninth Ann. Rept. U. S. Geol. Survey, p. 619, 1889. Two other 

analyses are given in this report.

a Bull. U. S. Geol. Survey No. 228, pp. 298-299, 1904. A very exceptional sinter, from 

a warm spring in Selangor, Malay States, contains, with 91.8 per cent of SiO2, 0.5 per 

cent of Sn02. See S. Meunier, Compt. Rend., vol. 110, p. 1088, 1890.

"Mon. U. S. Geol. Survey, vol. 13, pp. 343-346, 1888.

c For additional analyses see Roth, Allgem. chem. Geol., vol. 1, p. 593.
MINERAL WELLS AND SPRINGS. 163

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, p. 166, 1891. This sinter 

is- impregnated with auriferous hematite."

Ai2o3 . :.........:...................................

Fe2 03 . ..............................................

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

 KjO.................................................

Na2 0 ...............................................

NaCl........................................ ........

H2O. . ...............................................

SO3 .. ............ ...................................

G.

87. C7

} "

.40

.82

10.40

100. 00

H.

88.26

.69

3.26

.29

.11

.11

4.79

2.49

100.00

I.

94.20

1.58

.17

.85

i DA

99.86

J.

92.47

2.54

.15

.79

3 99

99.94

K.

94.02

} , 2. 27

.07

99.72

"In sinters from the geyser district of New Zealand, according to T. M. Maclaren 

(Geol. Mag., 1906, p. 5.11), there are also appreciable quantities of gold and silver.

The sinters, however, represent only the simplest form of deposit 

from geysers and siliceous springs. A great variety of intermediate 

substances, riiixtures 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 of the samples analyzed were collected in the Yellowstone 

National Park.

Analyses of spring deposits from Yellowstone Parlc.

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, p. 171, 1887. Contains scorodite.

II. Red, ocherous deposit, Arsenic Geyser. Air dried. .

SiO,.--. .............................

A12 63 ...... ..........................

Fe20a ...............................

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

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

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

Na^O. ...... .........................

KoO. ................................

LfoO.. ...............................

HoO....... ..........................

C62 .................................

S03 ... ...............................

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

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

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

K.

68.73

> 3.66

.29

2.14

6.15

18.79

99.76

F.

29.23

1.91

.07

.50

3.03

64.29

i.64

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 .2H2O., This occurs still more per-
164 THE DATA OF GEOCHEMISTRY.

fectly at Joseph's Coat Springs, in the Yellowstone Park, where the 

mineralhas been separated from an incrustation and identified." 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 

hew 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.

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, s'ulphuric 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

"A. Hague, Am. Jour. Sci., 3d ser., vol. 34, p. 171, 1887. See also J. E. Whitfield, Bull. 

U. S. Geol. Survey No. 55, p., 65, 1889..
MINERAL WELLS AND SPRINGS. 165

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 

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.

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 car-
166 THE DATA OF GEOCHEMISTRY. «*

bonate, forming sodium bicarbonate and a precipitate of gypsum. 

E. W. Hilgard 0 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 Daubree,6 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.0 Their 

solvent action on rocks and soils has been already noticed, as well as 

the fact that they also tend to retain silica in solution. Their effect 

is appreciable, but the precise nature of the compounds which they 

form is not certainly known.

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 

R. A. Duncan d 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,6 basic zeolitic silicates are tfte chief agents in 

effecting the retention of potassium, exchanging other bases for it

°Am. Jour. Sci., 4th ser., vol. 2, p.-100, 1896.

6 Etudes synthetiques de geologic expigrimentale, pp. 179 et seq., 1879. 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 mine'rales de la France, by E. Jacquot and E. Willm, p. 224, Paris, 1894. They 

confirm Daubr6e's statement.

0 See Chapter III, pp. 82-84, for details on this subject. Also A. A. Tulien, Proc. Am. 

Assoc. Adv. Sci., vol. 28, p. 311, 1879.

" Tour. Am. Chem. Soc., vol. 25, p. 47, 1903. See also vol. 24, p. 1114, 1902.

"Landw. Versuchs-Station. (Berlin), vol. 21, p. 135.
MINERAL WELLS AND SPRINGS. 167

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 sabstances are taken from waters by soils is certain, but the extent of 

the absorption depends upon local conditions. It is also certain that 

potassium, rather than sodium, is thus withdrawn from aqueous 

circulation.

A careful consideration of all the evidence concerning mineral 

springs will show that it is exceedingly difficult to generalize on relations between the composition of a water and its geological history. 

Reactions which take place deep within the earth can not easily 

be traced, especially as a water may undergo various modifications 

before it reaches the surface. A spring may be a blend from different sources either a direct mixture or a solution from which ingredients 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. AVe 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. DeLapparent" 

shows that soliataras are most common in regions of highly siliceous 

eruptive rocks, such as rhyolites, ande"sites, 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

"Compt. Rend., vol. 108, p. 149, 1889.
168 THE DATA OF GEOCHEMTSTRY.

being1 always calciferous, another relatively rich in bromine", and so 

on:0 But no law can be framed to cover even these regularities, for o j

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 generalize. It is better to discuss each water by itself, and so seek to 

unravel 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 

reopening of the question. E. Suess,6 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.'

THERMAL SPRINGS AND VOLCANISM.

The recent researches of Armand Gautier ll have indicated a very

close connection between volcanism and the formation of thermal 

springs. 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 kilo-

°A. C. Lane, Water-Sup, and Irr. Paper No. 31, U. S. Geol. Survey, 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, p. 199, 1901.

6 Geog. Jour., vol. 20, p. 520, 1902. 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, p. 783, 1887.

* See for example, W. Lindgren, Eng. and Min. Jour., vol. 79, p. 460, 1905. Also 

A. C. Spencer, Trans. Am. Inst. Min. Eng., vol. 35, p. 473, 1905; vol. 36, p. 364, 1906.

d Ann. Mines, 10th ser., vol. 9, p. 316, 1906. A good abstract by F. L. Ransome is 

given in Econ. Geol., vol. 1, p. 688, 1906.
MINERAL WELLS AND SPRINGS: 169

meter 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 ° 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 haliynite and lazurite,6 and also by certain artificial substances which Gautier himself has prepared. He also supposes that 

carbon oxysulphide, GOS, 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 

Avaters 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.0 Again, whence comes the sodium chloride of waters that 

flow from sources where it could not have been previously laid down ? 

These questions, and others like them, still await satisfactory answers. 

With mere suppositions, however plausible they may seem, we can not 

be content.

0 Compt. Rend., vol. 132, p. 740, 1901.

* Helvite and danalite are other natural sulpho-silicates which might easily take part 

in the supposed reactions.

c On vadose and juvenile carbonic acid In waters, see an elaborate discussion by R. 

Delkeskainp, Zcitschr. prakt. Geol., 1906, p. 33; reviewed by W. Lindgren, Econ. Geol., 

vol. 1, p. 602, 1906.
170 THE DATA OF GEOCHEMISTRY.

BIBLIOGRAPHIC NOTE:

The following collections of water analyses will be found useful 

for reference: '

F. RASPE. Heilquellen-Analysen, Dresden, 1885. A very large collection of 

analyses, mainly of European mineral waters.

T. E. THORPE. Dictionary of Applied Chemistry, article " Water," vol. 3, pp. 

952-959, 1893. Tables of analyses of European mineral springs. The 

same article gives much information about other waters.

J. K. CROOK. The Mineral Waters of the United States, New York and Philadelphia, 1899.

A. C. PEALE. The mineral springs of 'the United States: Bull. U. S. Geol. 

Survey No. 32, 1886.

F. A. GOOCH and J. E. WHITFIELD. Analyses of waters of the Yellowstone 

National Park: Bull. U. S. Geol. Survey No. 47, 1888.

E. ORTON. Rock waters of Ohio: Nineteenth Ann. Kept. U. S. Geol. Survey, 

pt. 4, p. 633, 1898. Contains many analyses of deep wells from various 

horizons.

W. H. NORTON. Artesian wells of Iowa: Iowa Geol. Survey, vol. 6, pp. 117-428, 

1896.

J. H. SHEPHERD. Artesian wells of South Dakota: Bull. No. 41, Agric. Exper. 

Sta., South Dakota, 1895.

J. C. BRANNER. Mineral waters of Arkansas: Ann. Rep.t Geol. Survey Arkansas, 1891, vol. 1.

E. H. S. BAILEY and others. The mineral waters of Kansas: Univ. Geol. Survey Kansas, 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. Rept. 

Indiana Dept. Geology and Nat. Resources, pp. 11-225, 1901.

A. C. LANE. The mineral waters of lower Michigan:. Water-Sup, and Irr. 

Paper No. 31, U. S. Geol. Survey, 1899.

W. ANDERSON. Mineral Springs and Health Resorts of California, San Francisco, 1892. Contains many analyses, the greater number of them by 

the author.

L. DE LAUNAY. Recherche, captage et amgnagement des sources thermominerales, Paris, 1899. 

A. CARNOT and others. Analyses of French and colonial mineral waters: Ann.

mines, 8th ser., vol. 7, p. 79, 1885; 9th ser., vol. 6, p. 355, 1894; vol. 16,

p. 33, 1899. These three papers contain 584 analyses. 

E. JACQUOT and E. WILLM. Les eaux minerales de la France, Paris, 1894.

Many analyses and descriptions of the springs.

 GUYON. Etudes sur les eaux thermales de la Tunisie, Paris, 1864. 

A. RAIMONDI. Aguas minerales del Peru: El Peru, estudios mineralogicos y

geo!6gicos, vol.. 4, pp. 235-394, 1902.

L. DARAPSKY. Aguas minerales de Chile, Valparaiso, 1890. 

E. ABEIXA Y CASARIEGO and J. DE VERA Y G6MEZ. 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.
MINERAL WELLS AND SPKINGS. l7l

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. Daubree's 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.
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 

in so far as the soluble salts are successively deposited and so removed 

from the sphere of chemical change. In salt and alkaline lakes we 

can recognize several stages of this process the precipitation of the 

relatively insoluble calcium sulphate, then of salt or sodium sulphate, 

the production of bitterns, like the water of the Dead Sea, and finally 

of solid beds of various saline materials. What are these saline residues, and what conditions govern their formation ?

The most important of these substances, considering the magnitude 

of the deposits, are sodium chloride and calcium sulphate, and their 

most probable origin is the evaporation of sea water or its equivalent 

' 172 .
SALINE RESIDUES. 173

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 Silurian 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 

seasonal 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

« Ann. chiui. phys., 3d ser., vol. 27, pp. 92, 192, 1849.
174 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.

^

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

Br....................................................... .......

S0t . ........................................... ................

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

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

K. ................... ..I........................................

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

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

A.

54.39

1.15

7.72

.18

31.08

.71

1.18

3.39

100.00 

3.766

B.

56.18

1.22

5.78

32.06

.78

.26

3.72

100.00 

27. 546

C.

49.99

2.68

14.64

' 20. 39

2.25

10.05

100.00 

33. 712

D.

49.13

3.03

17.36

12.89

3.31

14.28

100.00 

39. 619

The determinations of bromine in these analyses are obviously excessive and those of potassium are low, but otherwise the data in the 

first column, considering the time when they were made, agree fairly 

well with the more recent figures given in Chapter III of this volume. 

They show, first, the elimination of calcium as carbonate, and later 

as sulphate, then the deposition of sodium chloride, and finally the 

accumulation of the more soluble substances in the mother liquors.

In his study of saline deposition Usiglio started with 5 liters of 

sea water, and determined the character'and quantity of the salts laid 

.down at successive stages of concentration. In the following table the 

results of his experiments appear, but are reduced to the initial unit 

volume of 1 liter. The quantities given are in grams.

Salts laid down in concentration of sea water.

Density.o

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

Total 

Salts in las

Sum

Volume.

1.000 

.533 

.316 

.245 

.190 

.1445 

.131 

.112 

.095 

.064 

.039 

.0302 

.023 

.0162

Jeposit... 

t bittern .

FosQa.

0.0030-

.0030

. 0030

CaCOg.

0. 0642 

trace 

trace 

.0530

.1172

.1172

CaSO< 

2HaO.

6.5600 

.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

MgCh.

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

: Given by Usiglio in Baum£ degrees. Restated here in the usual specific.gravities.
SALINE RESIDUES. 175

Upon further concentration of the mother liquors Usiglio obtained 

variable results. Mere cooling from the temperature of day to that 

of night was sufficient to precipitate additional magnesium sulphate, 

which redissolved partially the day following. After that more salt 

was thrown down, then-the double sulphate of magnesium and potassium, next the double chloride of the same metals, and finally magnesium chloride crystallized out. In the table of results just given 

the order of deposition is clearly shown. First, ferric oxide and 

calcium carbonate; then gypsum; then salt, the latter beginning to 

appear when the water had been concentrated to about one-tenth of 

its original volume.

In its general outlines, then, the concentration of sea water is a 

simple phenomenon, but in its details it may be very complex. The 

localities at which it can be completely traced are comparatively few 

and the natural records of it are, as a rule, defective. The mother 

liquors are easily drained or washed away, leaving no trace of their 

existence, and some saline deposits have been partially redissolved 

and laid down with modified composition elsewhere. Salt and gypsum may thus be separated, and so the normal order of their association becomes disturbed. Beds of salt, therefore, may be divided 

into classes as primary and secondary, or as complete and incomplete, 

according to their saline character or- the 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," and more recently by 0. 

Ochsenius.6 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 evapora0 Lehrb. chem. phys. Geol., 2d ed., vol. 2, p. 48, 1864.

6 Die Bildung der Steinsalzlager und Hirer 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 Wiistenbildung, Berlin, 1900. Ochsenius replied in Centralbl. Min. Geol. Pal., 1902, pp. 551, 557, 620; and a rejoinder by Walther 

appeared in the same journal, 1903, p. 211.
176 THE DATA OF GEOCHEMISTRY.

tion. 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. V

This theory of Ochsenius, however, is not the only one possible to 

account for the concentration of salt. It must be remembered that salt 

is not deposited from sea water until the latter has been concentrated 

to about one-tenth of its original volume. Suppose, now, a large sheet 

of water to be cut off from the ocean by any change in the level of the 

land, and also that it contains within its area a deep depression. In 

that depression the water will gradually become concentrated, and 

its saline load will tend to accumulate there. A layer of salt would 

thus form of much greater thickness than if evaporation took place 

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 dep'osit 

might also be reenforced by leachings from other salt beds, or from t 

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: a 

1. Drift, about 8 meters thick.

2. Shales, sandstones, and unconsolidatetl clays, of varying thickness.

3. Younger rock salt, thickness very variable, sometimes missing.

a From data given by H. Precht in Die Salz-Industrie von Stassfurt und Umgegend, 

1889; L. Loewe, Zeitschr. prakt. Geol., 1903, p. 331; H. M. Cadell, Trans. Edinburgh 

Geol. Soc., vol. 5,. p. 92, 1884 ; and G. Lunge in Thorpe's Diet. Applied Chem., vol. 3, 

p. 265. See also C. Ochsenius, on Loewe's paper, Zeitschr. prakt. Geol., 1904, p. 23; 

and on the potash salts, idem, 1905, p. 167. J. Westphal (Zeitschr. Berg., Hiitten. u. 

Sal. Wesen preuss. St., vol. 50, p. 1, 1902) 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, p. 403, 

1905. Other references may be found in a bibliography of saline minerals, Zeitschr. 

prakt. Geol., 1905, p. 183.

y.
.SALINE KESIDUES. 177

4. Anhydrite, rarely lacking, 80 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 schoeiiite. These subzones are often 

missing.

7. The kieserite zone. 

S. 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 centimeters thick, separating the salt into sheets of 8 or 9 centimeters. These layers have been interpreted as annual deposits, due possibly to seasonal variations in temperature or to alternating drought and 

rain. If this supposition is correct, a Stasefurt salt bed 900 meters thick 

would require ten thousand years to form.

10. Anhydrite and gypsum.

We have now a complete record of the saline deposition at Stassfurt, ranging from the calcium sulphate at the bottom to the mother 

liquor or carnallite salts at the top. Above the carnallite a protecting layer of clay was laid down; and, after that, probably, a new 

accession of sea water began the formation of a second series of 

beds." 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,6 and pyrites, also, is sometimes found in the deposits.

" Some 'writers regard the younger salt as having been formed by re-solntion of older 

salt and redeposition here. 'As the discussion is geological and not chemical, it is unessential to our present purposes.

6 Pfelffer, Arch. Pharm., 3d ser., vol. 27, p. 1134, 1890.

14399 Bull. 330 08 12
178 THE DATA OF GEOCHEMISTRY.

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 _________________CaSO4 .

Gypsum o_.________.________-CaS04.2I-LO.

Glauberite_____________CaSO4.Na3 SO4 . 

Polyhalite_-________________.2CaSO4 .MgSO4 .2H20.

Krugite_..____________-4CaSO4.MgSO4 .K2SO4 .2I-LO. 

Kieserite_____________.MgSO4.H2O. ' 

Epsomite_____________^.MgSO47H2 0 (reichardtite). 

Vanthoffite._________________.MgSO4 .3Na2S04 .

Bloedite_______________MgS04.Na2S04.4H2O (astrakanite).

Loewite________________. MgSO4 .Na:! SO4.2^H2O.

Langbemite.-______i______2MgSO4.K2 SO4.

Leonite_________________MgS04.K2S04.4H2O.

Picromerite MgSO4 .KoSO4 .6H.O (schoenite). 

Aphthitalite ________.K3Na(SO4 )2 (glaserite).6

Kaiuite._________________MgSO4 .KC1.3H2O.

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, perhaps as secondary minerals, higher up. According to H. Precht,0 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 three 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, 

is associated with aphthitalite and loewite in the same horizon. The

"Probably, as A. Geuthcr (Liebig's Annalen, vol. 218, p. 297, 1883) has shown, the 

formula here given to gypsum should be doubled. It then becomes Ca2S_Os.4H3O, and the 

hemihydrate, Ca.SaOs.HzO, a. well-known artificial compound, furnishes evidence in favor 

pf the higher formula.

"According to B. Gossner (Zeitschr. Kryst. Min., vol. 39, p. 155, 1904), glaserite is a 

definite species with the formula given above. J. H. Van't Hoff and H. Barschall 

(Zeitschr. physikal. Chemie, vol. 56, p. 212, 1906) question the definiteness of the mineral, and regard it as a mixture of the two component sulphates.

"Zeitschr. angew. Chemie, 1897, p. 68.
SALINE RESIDUES. 179

loewite is probably formed by dehydration of bloedite," 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,6 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 Avhich 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." 

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 " Hurtsalz " contains these substances together with kieserite. 

Douglasite, K2MgCl4 .2I-LO. 

Carnallite, KMgCl,.6H,O.

Tachhyclrite, 2MgCls.CaCl2 .12H.O=8 (RC12 .4H2O). 

Bischofite, MgCl a .6HB 0.

With the exception of the rock salt, which forms the great mass 

of the deposits overlying the anhydrite, these chlorides represent the 

concentration of the mother liquors in the carnallite zone. They were 

the most soluble compounds potentially existing in sea water, and, 

with the sulpha to-chloride, kainite, were among the last substances

" See .T. IT. Van't Hoff, Sitzungsb. Akacl. Berlin, 1902, p. 414. Also Van't Hoffi and W. 

Meyerhoffier, idem, 1903, p. 678; 1904, p. 659.

6 Mineralog. Mag., vol. 12, p. 159, 1899.

" Vnn't Hoffi 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 Hoffi, 'Physical 

Chemistry in the Service of the Sciences, Chicago, 1903 ; Znr 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. Jiinecke, Zeitschr. anorg. Chemie, 1906, p. 7.
180 THE DATA OF GEOCHEMISTRY.

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,* 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 1 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,6 Avhen 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. 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

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.

We are now in a position to trace more distinctly the phenomena 

which attend the formation of the'beds at Stassfurt.0 For a long 

time only gypsum was deposited; but later, as the concentration of

0 Sitzungsb. Akacl. Berlin, 1902, p. 1106. See also J. H. Van't Hoff, F. B. Kenrick. 

and H. M. Dawson, Zeitschr. physikal. Chemie, vol. 39, p. 27, 1902, on the conditions of 

formation of tachhydrite.

"Centralbl. Min. Geol. Pal., 1904, p. 254.

c Cf. G. Lunge, Thoi-pe's Diet. Applied Chem., vol. 3, p. 268, 1893.
SALINE KESIDUES. 181

the bay increased, salt also was laid down, and by its action the gypsum was converted into anhydrite.* 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 Avith the 

salt. 6 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, CaK.2 (S04 ) 2 .H2 0, 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.0 The occurrence of 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 e 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, especially sylvite and kainite, 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, 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,

0 According to J. H. Van't HofE and F. Weigert, Sitzungsb. Akad. Berlin, 1001, p. 1140, 

anhydrite forms from gypsum in sodium chloride solutions at 30°. In sea water the 

transformation takes place at 25°.

6 Cf. .T. H. Van't Hoff and P. Farup, Sit7,ungsb.' 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, Sitzungsli. Akad. Berlin, 1900, p. 1084.

'' A. Aigner (Oesterr. Zeitschr. Berg. Hiitt, 1901, p. 68G) has described the Austrian 

polyhalite. For analysis of kainite, carnallite, etc., from Kalusz and A.ussee, sec C. von 

John, Tahrb. K.-k. geol. Rcichsanstalt, vol. 42, p. 341, 1892. On mirabilite from Kalusz, 

see 11. Zaloziccki, Monatsh. Chemie, vol. 13, p. 504, 1892.

6 Ber. Deutsch. chem. Gesell., vol. 14, p. 2131, 1881.
182 THE DATA OF GEOCHEMISTRY.

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 studjdng the transformation of 

gypsum into anhydrite, or the reverse reaction which has often been 

observed.0 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 from 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 6 as follows:

1. Glauberite, formed above 10°.

2. Langbeiuite, formed above 37°.

3. Loewite, formed above 43°.

4. Vanthofflte, 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.

OTHER SAI/T BEDS.

The Stassfurt deposits, as has already been indicated, are altogether exceptional in their completeness. Rock salt is generally 

found in-much thinner deposits, and as a rule it is unaccompanied 

by potassium or magnesium salts in any notable quantities. Gypsum 

or anhydrite, however, is commonly present, either under the salt 

or in its near neighborhood. Where gypsum is absent we may infer, 

with a fair degree of probability, that the salt is of secondary 

origin and not. derived directly from sea water, or that it came from 

the evaporation of a salt N lake which contained either no calcium or 

no sulphates. Gypsum, of course, can not form unless its constituents are at hand. Furthermore, gypsum may be produced otherwise 

than from the concentration of sea water, and it may exist as a

"Cf. F. Hammerschmidt, Min. pet. Mitth., vol. 5, p. 272, 1882-83; and .T. F. McCaleb, 

Am. Chem. Jour., vol. 11, p. 34, 1889.

"Zeitschr. Elektrochemie, vol. 11, p. 709, 1905.
SALINE EESIDUES. 183

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.* Here the origin from sea water is evident. On the 

other hand, waters containing little or no salt often deposit gypsum. 

I. C. Russell,6 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,c 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,d for example, prepared selenite in measurable crystals by the action of a solution of 

ferrous sulphate on chalk.

In the Salina formation of New York gypsum occurs above the 

salt, and its presence is attributed bv Dana e to the alteration of the 

overlying " Wateiiime " beds. In this region the salt occurs in layers 

interstratified with shales, a series of shallow-water deposits having 

been successively covered by bodies of mud or clay/ At Goderich, 

Canada, a similar but not identical alternation has been observed.0 

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 dolo- 

'mite, 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.'1

ANALYSES OF SALT.

Neither salt nor gypsum is found in nature in a state of absolute 

purity, although that condition is sometimes very nearly approxia .T. D. Dana, Manual of Geology, 4th ed., p. 120.

''Mon. U. S. Geol. Survey, vol. 11, p. 84, 1885. The deposition of gypsum by Lake 

Chichen-Kanab,. Yucatan, was mentioned in Chapter V (p. 126). 

c See G. P. Merrill, Proc. U. S. Nat. Mus., vol. 17, p. 77, 1905.

 "Ann. Soc. ge"ol. Belg., vol. 23, p. cxxviii, 1895-9G.

 Manual of Geology, 4th ed., p. 554.

T See sections given in Bull. No. 11, New York State Mus., 1893.

o T. S. Hunt, Geol. Survey Canada, Kept. Progress, 1876-77, p. 221.

R 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, Bureau of-Soils, U. S. Dept. Agric., 1900.
184 THE DATA OF GEOCHEMISTRY.

mated. Being deposited from solutions containing other substances, 

some of the latter are always carried down and reveal their presence 

on analysis. Analyses of nock salt are exceedingly numerous, and 

only a moderate number, enough to show the range of variation in 

the mineral, need be cited here.0

A.na>lyscs of rock salt.

A. Salt from Goderich, Canada. Analysis by Gould, for T. Sterry Hunt, Geol. Survey Canada, Rept. Progress, 1876-77, p. 233.

B. Salt from Kingman, Kansas. Analysis by E. H. S. Bailey and E. C. Case, Univ. 

Geol. Survey Kansas, vol. 7, p. 73, 1902. 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., 1883, p. 564, U. S. Geol. Survey.

E. Salt from Leoncito, La Rioja Province, Argentina. Analysis by L. Harperath, Bol. 

Acad. nac. cien. COrdoba, Argentina, vol. 10, p. 427, 18QO. . 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. II. Dunn, published by P. P. Bedson, Jour. Soc. Chem. Ind., vol. 8, p. 

98, 1889.

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, 

p. 734, 1890.. An analysis of the lake water by A. Pappe and H. D. Richmond is also 

given in this journal. See anle, p. 133.

NaCl... .......................

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

CaCl2 . ..........................

MgCIs. .........................

NaaSO4 ........... \...... ......

K2SO<. .........................

GaS04 ...... ....................

MgSO<.. .......................

NajCOs........................

AljOj..... .....................

Fe2 03 . .........................

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

HS0. ........ ...............:...

A.

99. 687

.032

.095

.090

.017

.079

100. 000

B.

97. 51

.10

.57

1.51

.11

.20

100. 00

0.

71.82

21.98

.99

1.29

3.56

}

iq .U

.23

100.000

D.

98. 731

.013

1.192

.010

.024'

.030

100. 000

E.

81. 491

17.483

.048

.978

100. 000

F.a

99.00

.52

.15

.28

99.95

G.

82.71

5.32

8 JO

2 

' 46

.82

99.89

0 This analysis, in the original, is stated in the form of radicles, 

here to salts for uniformity with the others.'

It is recalculated

In addition to the impurities shown in the analyses, rock salt frequently contains gaseous inclusions.. These have been often examined, 

most recently by N. Costachescu,6 who finds some of them to consist mainly of nitrogen, and others mainly of methane. Other hydrocarbons and carbon dioxide are also found. Rock salt is not uncoma See Thorpe's Diet. Appl. Chem., 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. No. 11, 

New York State Mus., 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, p. 4, 1889, for 

analyses of Roumanian salt. Some Roumanian samples contain as high as 99.9 per cent 

of sodium chloride,

6 Ann. Univ. Jassy, vol. 4, p. 3, 1906. The author gives a good summary of earlier 

investigations.
SALINE B.ESIDUES. 185

monly colored, especially blue. This coloration has been attributed 

to organic matter, and recently, by H. Siedentopf," to the presence of minute particles of metallic sodium. This very remarkable 

conclusion would seem to require confirmation.

 v

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.

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. Alleu. This material evidently contains 

admixed anhydrite."

S03 .. ...............................................

COa. ................................................ ci.......................... ..........................

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

AliOs. ..............................................

Fe2 03 ...............................................

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

NauO ...............................................

K20. . .................'..............................

H2O .................................................

A.

. 46. 18

} ,0

32.37

} ,0

20.94

.10-

99.79

B.

40.18

.03

.08

32. 33

.05 1 '"

20.96

.05

99.82

C.

45.45

.85

.10

.12

32. 44

.33

20.80

100. 09

D.

48. 14

.05

35. 29

is. 88

99. 96

E.

39.53

7.73

.04

1 . 

38. 46

.24

.07

.19

12. 69

.45

99. 54

" 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, p. 407, 1903 ; G. P. Grlmsley, Geol. Survey Michigan, vol. !). 

pt. 2, 1903-4, and Am. Geologist, vol. 34, p. 378. 1904 ; F. A. Wilder, Tour. Geol., vol. 

11. p. 723, 1903; 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.

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 reported, and only a feAv examples can be given here.& 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 \V. 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. Tour. Sci., 2d ser., vol. 44, p. 80, 1867.

" Phyaikal. Zelt.schr., vol. 6, p. 855, 1905. See also L. Wohler and IT. Kasarnowski, 

Zeitsclir. anorg. Chemie, vol. 47, p. 853, 1905, and F. Cornu, Centralbl. MIn. Geol. Pal., 

1907, p. 16G. . .

6 In addition to Usiglio's analyses cited on p. 174, ante.
186 THE DATA OF GEOCHEMISTRY.

C. Bittern from the brine of Bay City, Michigan. Analysis by E. S. Fitch, cited by 

AV. F. Cooper, Kept. State Board Geol. Survey Michigan, 1905, p. 389.

D. Bittern from the saline of Medellin, Antioquia, Colombia. Analysis by J. B. Boussingault, Ann. chim. phys., oth ser., vol. 2, p. 102, 1874. 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, p. 24, 1882.

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

Br..................................................

I....................................................

so,...:........ ....................................

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

K.... '....................................... .:.......

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

NIT............ ....................... ..............

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

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

SiO2 . .............s..i. ..............................

A.

52.63

.27

15.14

18.89

1.88

11 19

100.00

04 crc

 B.

63.93

1.16

.06

10.24

5.27

11.26

8.08

100.00 

33. 567

C.

57.56

19.23

.54

4.31

9.37

5.17

3.82

100.00

9

f\AK

 D.

. 44.99

1.02

.03

14.07

25.97

11.18

.09

.28

2.37

100.00 

33. 478

E.

55. 50

.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.*1 A. L. Baker 6 reports that 

20 to 30 gallons of Kanawha bittern will yield 1 pound of bromine, 

and he has also shown that they contain iodine in very appreciable 

amounts, from 38.4 to 59.2 milligrams per liter. The richness of the 

Dead Sea in bromine has already been pointed out. Bitterns of 

this class deserve a more careful study than they seem to have yet 

received.

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,

" 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.

6 Chem. News, vol. 44, p. 207, 1881.
SALINE RESIDUES. 187

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 a 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, Na2SO4 .10H2O; 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 

Roumania,6 large crystals of mirabilite form during winter, to redissolve, at least in part, when the weather becomes warm, and many 

other sulphate or sulphato-chloride lakes exhibit similar phenomena. 

The Siberian lakes, studied by F. Ludwig,0 deposit mainly sulphates; sodium sulphate in Lakes Altai, Beisk, Domoshakovo, and 

Kisil-Kul, Avhile in the Schimett 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.

Analyses of saline deposits in two Siberian laJces.a

A. Deposit on bottom of Lake Altai. 

B. Deposit on shore of Lake Altai. 

C. Deposit on shore of Schunett Lake.

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

SO3 . .....................................................................

NasO ................................................................... KjO ........................................................... :..........

NaCl .....................................................................

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

MgO...................................................................:.

A12 03 . ...................................................................

SiOj. .....................................................................

A.

0.12

54.00

41.04

.29

.22

.11

.11

Q9. 95

B.

0.03

55. 07

43.21

. 13

.01

} .0,

.91

99.97

0.

0. 03

54. 45

 1.93

.92

.07

10.22

.07

.01

.07

f>. 70

100. 03

" 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.

These lakes, Altai and Schunett, are sulphato-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 exem-

" G. K. Gilbert, Mon. U. S. Geol. Survey, vol. 1, p. 253, 1890.

6 L. Mrazec and W. Teisseyre, -Apergu ggologique sur les formations saliferes et les 

gisements de sel en Roumanie, 1902. This memoir contains a bibliography relative to 

Roumanian salt.

« Zeitschr. prakt. Geol., vol. 11, p. 401, 1903. Cf. ante, p. 131.
FT188 THE DATA OF GEOCHEMISTRY.

plified by Sevier Lake, in Utah, which is at times entirely dry, forming a thin saline layer that in moister seasons partly redissolves." 

The deposits from, this lake have been analyzed, those from the 

margin by O. D. Alien, those from the center by S. A. Lattimore, and 

their average composition, as cited by (Gilbert, is given below:

Averar/e composition of deposits from Sevier LaJce, Vtah.

Na2S04 ..............................................................................

NajC03 ......... ........ ............................................................

NaCl.................... ...... .....................................................

CaSO< ..............................................................................

MgSO...............................................................................

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

HsO ................................................................................

Margin.

14.3

75.8

5.5

.7

3.6

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 

water. Suppose, now, following a suggestion of J. Walther,'J 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.

MISCELLAl^EOUS 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

« G. K. Gilbert, Mon. U. S. Geol. Survey, vol. 1, pp. 224-227, 1890. See p. 120, ante, 

for the composition of the brine.

6 Das Gesetz der Wiistenbildung, p. 149, Berlin, 1900. Chapter 13 is devoted to the 

subject of desert salts.
SALINE EESIDUES. 189

recorded. To the sulphate-chloride class the subjoined analyses belong, the other saline deposits being left for separate consideration 

later.0

Analyses of saline deposits from sulphato-chlorhle waters.

A. Salt, Osobb Valley, Nevada. Analysis by R. W. Woodward, Kept U. S. Geol. Explor. 

40th I'ur., vol. 2, p. 707, 1877.

B. Saline efflorescence on desert, south of Hot Springs station, Nevada. Analysis by 

0. D. Alien, idem; p. 773.

C. Incrustation from Quinns Riven crossing, Black Rock Desert, Nevada. Analysis by 

O. D. Alien, idem, p. 791.

D. Salt from Salt Lake, 7 miles east of the Zandia Mountains, New "Mexico. Analysis 

by 0. Loew, Kept. U. S. Geol. Surv. W. 100th Mer., vol. 3, p. 627, 1875.

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 0. Loew, op. cit., p. 628.

G. Salt from shore of lake near Percy, Nevada. Analysis by R. W. Woodward, Kept. 

U. S. Geol. Explor. 40th Par., vol. 2, p. 148, 1877.

H. Efflorescence on loess, near Cordoba, Argentina. Analysis by Doering, cited by 

A. W. Stelzner, Beitrlige zur Geol. u. Palaeont. der Argentinischen Repub., 1885. A 

number of salts, etc., are described on pages 295-300. This one is remarkably rich in 

potassium.

NaCl. ...... .........

Na«S04 ...... ........

NosCO,.........-..-.

v cn

MgCl 2 . :..........-..

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

CaS04 .. .............

HoO. ................

A.

95.49

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.

82.67

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

Q 71

100. 00

These analyses, taken in connection with those of salt given on page 

184, 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; but partial re-solution in time of high water 

can reverse the process and bring about a new distribution of the 

soluble substances.

ALKALINE CARBONATES.

From alkaline lakes alkaline carbonates are deposited, mingled with 

chlorides and sulphates in varying proportions. In Hungary, Egypt, 

Armenia, and Venezuela such deposits are found, and they are peculiarly common in the Lahontan basin of Nevada, and in southern 

California. In Nevada they often form " playas," or " playa 

lakes " 6 beds which are dry in summer and flooded to the depth of 

a few inches during the wet season. A number of these alkaline

a A number of analyses of similar products from Argentina are given by F. Schickendantz, Revista del Museo de la Plata, vol. 7, p. 1, 1895.

6 See I. C. Russell, Mon. U. S. Geol. Survey, vol. 11, p. 81, 1885.
190 THE DATA OF GEOCHEMISTRY.

incrustations were analyzed by the chemists of the Fortieth Parallel 

Survey, with the results shown in analyses A to F of the subjoined 

table.® 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 in alkaline lakes.

A. Prom western arm of Black Rock Desert, ; near the so-called " Hard in City," 

Nevada. Analysis by 0. D. Alien, vol. 2, p. 792, 1877.

B. From Ruby Valley, Nevada. Analysis by R. W. Woodward, vol. 1, p. r>(K5, 1878.

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 the 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, 28.10 per cent.

NaHCO3 . ............................

NasS04. .............................

NaCl................. ...............

NaaB4O7 .. ...........................

K»S04. ..............................

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

SiOj................ ..................

\

A.

52.10

27.55

18.47

9R12

B.

58.69

8.09

28.32

2.11

2.79

100.00

C.

25.12

14.76

17.43

38.01

468

100.00

D.

25.95

1435

33.31

2451

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

A 1 C

1.18

1 96

100. 00

H.

9.06

27.05

59.32

1.00

1.39

2.18

100. 00

The following table contains analyses, reported by E. W. Hilgard,6 

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 soluble part 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 . ......................................................

Na2SO< ........................................................

NaCl..........................................................

NaN03 . .......................................................

NaHsPO4 . ....................................................:

KzC0.4 .........................................................

KjSO....... ....................................................

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

(NH4) 2C03 ............... ............... ......................

A.

65.72

3.98

8.42

20.23

1.65

100. 00

B.

62.22

10.57

0.59

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

12.98

4.94

100. 00

0 The analyses are here cited as recalculated by T. M. Chatard, Bull. U. S. Geol. Survey 

No. 60, pp. 55, 56, 1890. The original statements do not adequately discriminate between 

carbonates and bicarbonates.

6 Appendix, Rept. Univ. California Exper. Sta., 1890. Other analyses are given in this 

report.
SALINE EESIDUES. 191

Similar deposits are formed by the two soda lakes at Kagtown, 

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.0 The analyses are as follows, in the form adopted 

by Chatard:

Analyse* of deposits from Soda Lakes, Kagtown, 'Nevada.

A. Big Soda Lake. Analysis by O. D. Alien, Kept. U. S. Geol. Explor. 40th Tar., vol. 

2, p. 748, 1877.

B. Little Soda Lake. Analysis by Alien, op. cit, p. 759. 

C. Little Soda Lake, market soda. Analysis by Chatard.

NajCOa.............. ....................................................

NaHCOa. ................................................................

NajSO,.............................................................:....

NaCl................................................ ....................

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

HsO.... ..................................................................

A.

45.05

34. 66

1.29

1.61

.80

16.19

99. GO

B.

44.25

34.90

.99 i.io2.81

15.95

100. 00

C.

52.20

25.05

5. 10

3.31

.27

14.16

100.09

These soda lakes also deposit crystals of gaylussite, of the formula 

CaCO3 .Na2CO;i .5H2 0,6 although the analysis of the water c reveals 

no calcium. Probably the minute quantities of calcium that enter 

the waters from springs or otherwise are immediately removed in 

this form.

1 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, Na2CO;,.H2 0; natron, 

Na,CO3 .10H2 0; and trona, or urao, Na2CO3 .NaHCO:r2H2O. Sometimes one and sometimes another of these salts is in excess, but the 

third is the most important, as the elaborate researches of T. M. 

Chatard d have shown. That this is the first salt to be deposited 

from waters of this class his experiments upon Owens Lake water 

clearly prove.

0 Bull. U. S. Geol. Survey No. 60, p. 52, 1890. Chatard cites a number of analyses 

of foreign urao or trona. For analyses of Egyptian urao see 0. Fopp, Liebig's Annalen, 

vol. 155, p. 348, 1870.

" See analysis by O. D. Alien, Rept. U. S. Geol. Explor. 40th Par., vol. 2, p. 749, 1877.

11 See p. .123, ante.

'* Natural soda; its occurrence and utilization : Bull. U. S. Geol. Survey No. 60, pp. 

27-101, 1890. Cf. E. Le Neve Foster, Proc. Colorado Scl. Soc., vol. 3, p. 245, .1890, for 

data concerning Owens Lake. See also G. Lunge, Zeitschr. angew. Chemie, 1893, p. 3.
192 THE DATA OF GEOCHEMISTRY.

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

Analyses of salts deposited by fractional crystallization from water of Oivens

LaJcc, California.

A. The natural water of Owens Lake. Specific gravity 1.062 at 25°. Salinity 77.098 

grams per liter. This analysis was cited on page 124 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.

HjO...... ................................

NasCOa...................................

NaHC03 ... ...............................

NasSO*.. .................................

NaCl ......................................

NaBOn.... ...............................

KC1..........................:...........

(CaMg)COa. ..............................

(AlFe) 2O3 . ................................

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

Organic matter. .........................

Insoluble ........................... .....

A.o

34. 95

7.40

14.38

38.16

.63

4.07

.08

.05

' .28

100.00

B.

14.51

43. 75

30.12

3.18

7.44

1.07

.14

.01

..055

.032

.078

100.385

C.

4.33

22.84

10.53

25.44

35.06

1.12

1 .09

1

99.41

D.

3.43

18.19

4 06

26.70

45.59

1.14

[ .06

}

99.17

E.

2.24

19 t;i

3. 88

19.01

60.99

1.21

.01

nz

99.90

F.

11.03

55.04 4 09

5.70

19.16

62.01 v.

2. 93

09

.16

100.14

a Composition of the anhydrous residue.

6 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, Na2C08 .NaHC03 .2H2 0, with a small excess of the 

normal carbonate, some chloride, and some sulphate. In C, D, and E 

the carbonates diminish, but the normal salt is even more largely in 

excess, while the chlorides increase rapidly. The final, chilled solution deposits chiefly sodium carbonate, with some chloride and less 

sulphate. The order of deposition is trona, sodium sulphate, sodium 

chloride, and finally, if we ignore the minor constituents of the water, 

the very soluble normal carbonate. Of the trona itself Chatard made 

several analyses, and he also prepared a series of artificial products, 

which established the true formula of the compound.® The best

0 Cf. also C. Winkler, Zeitschr. angew. Chemie, 1893, p. 446 ; and B. Reinitzer, idem, 

p. 573.
SALINE KESIDUES. 193

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.

NaiiOOs. ........................................................................

NaHCOs. ........................................................................

Nad ...........................................................................

Na2SO< .........................................................................

II 20 ............................................................................

Found.

45. 86

36.46

.32

1.25

16.16

.02

100.07

Calculated.

46. 90

37.17

15. 93

100. 00

The prevalent view concerning the origin of the Lahontan alkalies 

was stated in Chapter V (p. 124). 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.a 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 necessarity valid elsewhere. In order to account for

" See analyses by T. M. Chatard, Bull. U. S. Geol. Survey No. 60, p. 94. 1890. Chatard 

nlso discusses the origin of the carbonates and cites the views of earlier investigators concerning other localities.

1 4399 B u 1 i. 330 OS 13
194 THE DATA OF GEOCHEMISTRY.

the existence of sodium carbonate in natural waters, T. Sterry Hunt a 

assumed a double decomposition between sodium sulphate and calcium bicarbonate, gypsum being thrown down. A similar reaction is 

accepted by E. von Kvassay 6 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 c 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 gypsuimcan be deposited, while sodium 

bicarbonate remains dissolved. In Hilgard's experiments, however, 

he precipitated and removed the calcium sulphate by means of alcohol, a condition unlike anything occurring in nature. S. Tanatar/* 

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,e who examined the natron lakes of Egypt, observed the presence in them of alga3, 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/ 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, sulphate, 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.

"Am. Jour. Sci., 2d ser., vol. 28, p. 170,. 1859.

& Jahrb. K.-k. geol. Reichsanstalt, 1876, p. 427. Cf. also H. Le Chatelier on Algerian 

salts, Compt. Rend., vol. 84, p. 396, 1877. Von Kvassay gives a bibliography of the Hungarian occurrences and some analyses of the soda.

 < Am. Jour. Sci., 4th ser., vol. 2, p. 123, 1896. See also paper in Kept. Univ. California 

Agric. Exper. Sta. 1890, p: 87, followed by an experimental research by M. E. Jaffa.

d Ber. Deutsch. chem. Gesell., vol. 29, p. 1034, 1896. See also a memoir by H. Vater, 

Zeitschr. Kryst. Min., vol. 30, p. 373, 1899.

» Chem. Zeitung, 1892, pp. 1645, 1691.

t Zeitschr. Gesell. ISrdkunde, vol. 33, p. 1, 1898. Several references to bacteriological 

researches are given in this memoir.
SALINE RESIDUES. 195

We have, then, three theories by which to account for the formation of alkaline carbonates in natural waters and soils." 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 Avaters 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, HiIgard attributes the common presence of sodium 

carbonate in the soils of arid regions, a mode of occurrence which 

is very widespread and of the utmost importance to agriculture. 

The reclamation of arid lands by irrigation is profoundly affected 

by the presence of these salts, which sometimes accumulate to such 

an extent as to destroy fertility. Exc.essive irrigation may defeat 

its own purpose and destroy the value of land which might be 

reclaimed. from the. desert by a more moderate procedure.*' 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 Avere noted. The latter Avere hot springs, situated 

in A^olcanic regions, as in the YelloAvstone Park- a mode of occurrence which must be borne in mind if Ave are to determine the origin 

of these substances. We must also remember that borates exist in 

sea Avater, from Avhich source the deposits at 'Stassfurt are supposed 

to .be derived. TAVO sets of facts, therefore, have to be considered

" To these theories may be added a fourth, that of C. Ochsenius (Zeitschr. prakt. 

Geol., 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.

6 The reports of the Bureau of Soils, U. S. Dept. Agric., and of the agricultural 

.experiment stations of several AA7 estern 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. No. 42 of the New Mexico College of Agriculture there is a summary of the literature on alkali soils.
196 THE DATA OF GEOCHEMISTRY.

in dealing with this class of compounds. Let us first examine the 

actual occurrences of borates as saline residues."

Borax Lake, Lake County, California, has been repeatedly described.6 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, hoAvever, 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 Valley, in Venezuela,0 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; (l 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___________________H3BO3 (orthoboric acid),

Larderellite-_ _______________ (NH4 ) 2BS0I8.4H2 0.

Bechilite-___________________CaB4O7 4H,O (borocalcite). 

Lagonite-_______ __________Fe"',B0O]L,.3H,O.

One of these salts is an ammonium borate, and another ammonium 

compound boussingaultite, (NHi) 2Mg(SO4 ) 2 .6H2O is also formed 

at this locality. According to C. Schmidt 6 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 f 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:

0 For general information about American localities see Mineral Resources U. S., 1882, 

p. 506; 1883-84, p. 858; 1889-90, p. 494; and 1901, p. 869, U, S. Geol. Survey.

6 Geol. Survey California, Geology, vol. 1, p. 97, 1865. G. F. Becker, Mon. U. S. Geol. 

Survey, vol. 13, pp. 264-268, -1888. H. G. Hanks, Third Ann. Kept. State Mineralogist 

(California). For analyses of the water and of an adjacent hot spring, see ante, pp. 124, 

154. This lake, situated about 80 miles north of San Francisco, must not lie confused 

with Searles's " Borax Lake " in San Bernardino County.

r See E. Cortese, Eng. and Min. Jour., vol. 78, November 10, 1904.

 ' See A. Bergeat, Zeitschr. prakt. Geol., 1899. p. 45.

« Ann. Chem. Pharm., vol. 98, p. 273, .1850. In vol. 102, p. 190, 1857, Schmidt also 

describes the rocks of the region.

f Ding, polyt. Jour., yol. 212, p, 493, 1874.
SALINE RESIDUES. 197

Foreign matter in Tuscan lagoon waters. 

[Grains per liter.]

Total solids.

8.565

G.720

2.005

22.575

Boric acid 

.(H3B03).

4.154

4.032

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, and essentially to ionic form, except 

that for the excess of boric acid I prefer to use the symbol H3B03 . 

Schmidt gives the total solids as 16.374 grams per liter, reckoning 

the free acid as BoO.,; as recalculated the sum becomes 18.548. The 

revised figures are as follows:

. Analysis of moilier liquor from Tuscan lagoon water.

01 -_-- -- -- -_---

SO., _- -_ 

H,BOS - _ -

Nil . __ _. . _.

K __ _ _____ _- - .

NH,

Grams 

per liter. 

__._ _._ 0.39

_____ 49.37

.__ __ _ 2.50

20. 92

__ __ _ .89

_ _ 1.01

._._ 1G. 71.

Ca_ -_____-_ 

Mg ________________

(AlFe)-Oa- ----- -

Mn,O, _ _ _

SiO., _ ___ _--___

Grams 

per liter. 

_______ 0.10

_ _____ _ 1.99

__ ___ _-__ .06

__ _ 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

0 R. Warington, Chem. Gaz., 1854, p. 41.9, with special reference to Vulcano, Lipari 

Islands. H. Sainte-Claire Deville and F. Woliler, Ann. Chem. Pharin., vol. 105, p. 71, 

1858. 0. Popp, idem, 8th supp. Bd., p. 5, 1870. E. Bechi, Bull. Soc. ind. min., vol. 3, 

p. 329, 1857-58.
198 THE DATA. OF GEOCHEMISTRY.

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, B2 S3 , also decomposed by steam, was the 

source of the boric acid contained in the " soffioni." * 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,6' 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 \vhich brought about the transformation of the original gabbro.

In recent years E. Perrone (l and R. Nasini ° have suggested that the 

Tuscan boric acid may be derived from the decomposition, by water, 

of tourmaline contained in deep-seated granites. This suggestion, 

however, does not account for the ammonium compounds.

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.f 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, NaCaB5 00 .SH2 0, is the 

principal borate. It occurs in nodules, known locally as " cotton 

balls," which have a fibrous structure and seem to be in process of 

formation, the smaller masses gradually becoming larger.-9 At

" See paper by A. Payen on the Tuscan fumaroles, Ann. chim. pliys., 3d ser.. vol. 1, 

p. 247, 1841. He adopts Dumas's theory.

''Ann. Chem. Pharm., vol. 68, p. 325, 1848.

* Atti Accad. Lincei, 3d ser., vol. 2, p. 514, 1878. See also a summary by H. Schiffi 

in Ber. Deutsch. chem. Gesell., vol. 11, p. 1690, 1878.-

d Carte idrographica d'ltalia, No. 31, p. 355, 1904.

e Abstract in Geol. Centralbl., vol. 8, p. 413, 1906. For a criticism.of Perrone and Nasini, 

see G. d'Achiardi, Atti Soc. toscana sci. nat., Memorie, vol. 23, 1907. 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 I-I. Coquand, Bull. Soc. ge'ol., 2d sea'., 

vol. 6, p. 91, 1848-49 ; C. Sainte-Claire Deville and F. Leblanc, Compt. Rend., vol.' 45, p. 

750, 1857 ; vol. 47, p. 317, 1858 ; and F. Fouque and H. Gorgeix, idem, vol. 69, p. 946, 

1869. The gases from the " soffloni " have been studied by R. Nasini, F. Anderlini, and 

R. Salvador!, Atti Accad. Lincei, 5th ser., Memorie, vol. 2, p. 388, 1895 ; as well as by 

some of the above-named authorities. Carbon dioxide is the principal gas.

'See H. G. Hanks, Third Ann. Rept. State Mineralogist California, 1883, and Am. Jour. 

Sci., 3d ser., vol. 37, p. 63, 1889; I-I. 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, p. 517, 1902.

'Kept. State Mineralogist Nevada 1871-72, p. 35.
SALINE BESIDUES. ' 199

Rhodes's marsh, according to Joseph Le Conte,a 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,1* 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 Seaiies's borax lake, has been 

worked since 18T3; and as it has yielded a number of new mineral 

species, it deserves special consideration here. In chemical interest 

it rivals Stassfurt, although its systematic study is hardly more than 

begun. Borings at this point, according to De Groot,c 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 black1 clay, with bunches of trona_____... ________ 8

4. Volcanic sand, containing glauberite, thenardite, and a few crystals of

lianksite ___________________________.:_____._ 8

5. Solid trona, overlain by a thin layer of very hard material________ 28 

G. 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: d

Anhydrite.-_______________._____.__.CaSCv

Gypsum______________________.CaSO4 .2H,O. 

Celestite...____-________-_____SrSO4 . 

Thenardite_ _____________________.Na2SO4 .

Glauberite____.________________Na2Ca (SO4 )-. 

Snlphohalite « _ ___.__. _ -Nao<SO«) sClF.

"Third Ann. Kept. State Mineralogist California, p. 51, 1883.

"Bull. TJ. S. Geol: Survey No. 213, p. 401, 1903: See also J. E. Spurr, Bull. TI. S. Oeo). 

Survey No. 208, 1903.

«Tenth Ann. Rept. California State Mining Bureau, p. 535, 1890.

d De Groot also mentions cerargyrlte, embolite, and gold ; but these minerals have no 

obvious relationship to the other species.

a S. L. Penfleld, Am. Jour. Sci., 4th ser., vol. 9, p. 425, 1900.
200 ' THE DATA OP GEOCHEMISTRY.

Haiiksite .N

Borax__ _ _ Na2B4O7 .10H2O. 

Colemanite --Ca2B0Ou.5H2O. 

Calcite _ _ __ - ____ __ CaCO3 . 

Dolomite ___ - MgCa(CO3 ) 2. 

Natron. ___ _ - Na_CO,.10HaO. 

Trona__. _________________ ----- Na3H(CO3 ) 2.2H2O.

Gaylussite" __ __________________ __ Na_Ca(CO8 ) a.5H2O.

Pirssoniteo __ ___ _ Na2Ca(CO3 ) 2 .2H2O. - 

Northupite « __ __________^___ ____ -Na3Mg(CO3 ) 2Cl.

Tychite & __ - __________.___..__. NaaMg2 (CO3 ) 4 SO4 .

Halite _____ ., __________ ______ -NaCI.

Soda niter ________ _ _ ____ - NaNO3 . 

Sulphur, from reduction of sulphates. 

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 

Vaii'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. 0 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 d bakerite having the empirical formula 

SCaO.SBaOa.GSiCX.GELO ; 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." 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

a J. H. Pratt, Am. Jour. Sci., 4th ser., vol. 2, p. 123 et seq., 1896 ; vol. 3, p. 75, 1897.

6 S. L. Penfield and G. S. Jamieson, idem, vol. 20, p. 217, 1905. The authors prepared 

tychite synthetically. Both northupite and tychite have also been made artificially by 

A. B. de Schulten, Bull. Soc. Min., vol. 19, p. 164, 1896, and Compt. Rend., vol. 143, p. 

403, 1906. The relations between the two species are perhaps more_ clearly expressed by 

formula? of the following type :

Tychite _____________ - ______ '. __ : _____ 2MgCOs.2NaaCO3.Na2S04 . . Northupite _______ ,. __________ _ ________ 2MgCO3 .2Na2CO3.2NaCl.

c See M. R. Campbell, Bull. U. S. Geol. Survey No. 200 ; and W. H. Storms, Eleventh 

Ann. Rept. California State Mining Bureau, p. 345, 1893.

<* W. B. Giles, Mineralog. Mag., vol. 13, p. 353, 1903.

e Information received from J. S. Diller, who has examined the locality.
SALTNE RESIDUES.

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,'1 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,6 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 C8H,0O38 .15H2 0. Colemanite, 

Ca2B6O1:L .5H2 0, forms from ulexite in a sodium chloride solution most 

readily at 70°. Van't Hoff, it Avill 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." This 

locality has been worked for borax, and the deposit is said to be continually reproduced. The region calls for more complete examination, especially on the chemical side.

In the arid region of southern California beds rich in 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 (l described 

the calcium borate from near Iquique, and noted its association with 

glauberite, gypsum, pickeringite, and a native iodate of sodium, D. 

Forbes,6 describing more fully the salines of this region, which he 

regarded as post-Tertiary, added salt, epsomite, mirabilite, thenardite, 

glauberite, soda alum, anhydrite, stfda 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 f he was able to confirm this view by finding a calcium' 

borate, either ulexite or bechilite, actually in process of deposition at 

the hot springs of Banos del Toro, in the Cordilleras of Coquimbo. 

L. Darapsky, in his work on the Taltal district/' 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

" Eng. and Min. Jour., vol. 74,-p. 517, 1902.

"Sitzungsb. Akad. Berlin, vol. 39, pp. 566, 689, 1906. ' 

0 W. D. Dennis, Bng. and Min. Jour., vol. 73, p. 58.1, 1902. 

d Am. Jour. Sci., 1st ser., vol. 47, p. 215, 1844. 

" Quart. Jour. Geol. Soc. London, vol. 17, p. 7, 1861. 

'Phil. Mag., 4th ser., vol. 25, p. 113, 1863.

"Das Departement Taltal (Chile), Berlin, 1900. See especially pp. 149, 150, 163. An 

abstract is printed in Zeitschr. prakt. Geol., p. 153, 1902.
202 THE DATA OF GEOCHBMISTKY.

Argentina, several borate localities are known. J. J. Kyle a 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.0

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,d 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." e 

It effloresces upon the surface of the dried mud, and is more or less 

mixed with salt and soda. 0

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______________________Mg7Cl2B18O30 .

Pinnoite_______________________: MgB2O4 .3H2O.

Ascharite______-______________3Mg,B2O62H,O.

Heintzite.____________________:_.K2Mg4Bo2O38 14H2O.

Hydroboracite__________________-CaMgB0On .6H2O.

Sulphoborite________________________ _-2MgSO44MgHB03 7H2O.

Of these species, hydroboracite is found in the lower deposits at 

Stassfurt, associated with anhydrite; the others are characteristic

a An. Soc. cient. Argentina, vol. 10, p. 169, 1880.

"Ann. Soc. gfiol.-Belg., vol. 28, M, p. 99, 1900-1901. Analyses of the ulexite are given. 

c In Chem. Ze'itung, vol. 30, p. 150, 1906, F. Reichert describes eight of the Argentine 

" borateras " and gives analyses of their products. 

d Sitzungsh. Acad. Munchen, vol. 8, p. 518, 1878. . 

« W. S. Vernadsky and S. P. Popoff, Zeitschr. prakt. Geol., 1902, p. 79.
SALINE BESIDUES. 203

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, arid that calcium, which 

is the dominant metal in the Chilean and Californian localities, 

occurs in only one of the Stassfurt species. This is Avhat 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.0 Howlite.is represented by the formula 

H5CaB2 Si014 ; cryptomorphite is probably H2Na4Ca0 (B4 07 ) 9 .22H2 0.6 

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.0

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 clatolite. 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 metarnorphism 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

"See H. How, Am. Jour. Sci., 2d ser., vol. 32, p. 9, 1861; Phil. Mag., 4th ser., vol. 35,' 

p. 31, 1868; vol. 41, p. 270, 1871.

6 Calculated by F. W. C. from How's analysis.

c The suggestion of J. VV. Dawson (Acadian Geology, p. 262, 1891), 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.
204 THE DATA OF GEOCHEMISTRY.

rocks.*1 That boric acid is emitted from volcanic vents is, however, 

unquestionable. It'is there associated with ammonium salts precisely 

as it is at Monte Cerboli an association which can not be overlooked 

or disregarded.

The marine origin of borates is most evident at Stassfurt, although 

even here their presence has been attributed to the injection of volcanic gases. Here, hoAvever, 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 Avhence 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 

to explain all these deposits by the marine hypothesis, as in the 

memoirs of C. Ochsenius 6 and L. Dieulafait. 0 Dieulafait tries to 

prove that all saline deposits are primarily derived from sea water, 

in either ancient or modern times, and even the Tuscan " soffioni " 

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 b.e 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

0 See, for example, a letter from W. P. Jervis, published by H. G. Hanks in Third Ann. 

Kept. State Mineralogist California, p. 68, 1883 ; also L. Dieulafait, Compt. Rend., vol. 

100, p. 1240, 1885.

ft Zeitschr. prakt. Geol., 1893, pp. 189, 217. Borates especially on pp. 222, 223.

c Ann. chlm. phy.s., 5th ser., vol. 12, p. 318, 1877; vol. 25, p. 145. 1882. Also Compt. 

Rend., vol. 85, p. 605, 1877; vol. 94, p. 1352, 1882 ; vol. 100, pp. 1017, 1240, 1885.
SALINE RESIDUES. ' 205

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." 

Magnesium berates 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 an}' 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.

NITKATES.

Nitrates are commonly formed in.soils by the oxidation of organic 

matter, a process in which the nitrifying micro-organisms play an 

imp6rtant 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 common]}' been attributed to the nitrification of bat 

guano.6 This supposition, however, may not cover all cases, for 

W. H. Hess c claims that nitrates are uniformly distributed over cave

" Some of the Chilean thermal waters, analyzed by P. Martens (Actes Soc. sci. Chili, 

vol. 7, p. 311, 1897), contain both borates. and ammonium salts, but not in remarkable 

proportions.

6 See A. Muntu and V. Marcano, Ann. chim. phys., 6th ser., vol. 1.0, p. 550, 18.37, on cave 

earth from Venezuela. For an account of: saltpeter earth in Turkestan see N. LjubaA'in, 

.Tour. Cheui. Soc., vol. 48, p. 128, 1885. On nitrate earth at Tacunga, Ecuador, see .T. B. 

Boussingault, Ann. chim. phys., 4th ser., vol. 7, p. 858; 1800, followed by a letter from 

Chabr'ie on Algerian saltpeter.

''.Tour. Geol., vol. 8, p. 129, 1900. The views advanced-by Hess have been disputed 

by 11. W. Nichols (.Tour. Geol/, vol. 9, p. 23G, 1901), who regards guano as .the chief 

source of cave nitrates. 
206 THE DATA OF GEOCHEMISTRY.

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 N2O5 , 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 Avhich nitrates are produced in the usual way. Earth gathered 

far Avithin the cavern contains nitrates, but almost no organic matter. 

The deposits of potassium nitrate found in Hungary are traced by 

C. Ochsenius" 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 in southern California, especially 

around Death Valley and along the boundary between Inyo and 

San Bernardino counties. 6 It is said to form beds associated with 

the later Eocene clays, and in some cases to impregnate the latter; 

but its direct conjunction with borates is not positively asserted, 

except in the locality at Searles's marsh. The fact that soda niter 

exists in the same region with the borates is important, however, for 

it correlates the California deposits with the Chilean beds, wljere a 

similar relationship is recognized. According to Bailey,0 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,* are found the largest known deposits of nitrates in the world. 

The crude sodium nitrate is termed locally " caliche," and the " cuIVcheras " are scattered over a large area which also contains beds : ,»f 

salt, "salares," and the deposits of ulexite which we have already 

considered. According to V. L'Olivier,6 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

« Zeitschr. prakt. Geol., 1893, p. 60.

»G. E. Bailey, Bull. No. 24, California State Mining Bureau, pp. 139-188, 1902.

c Op. cit, p. 170.

d The region was formerly a part of Peru and Bolivia.

« Ann. chim. phys., 5th ser.. vol. 7, p. 289, 1876. For other details see D. Forbes, Quart. 

Jour. Geol. Socv vol. 17, p. 7, 1861; 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 .T. W. 

Flagg is given in Am. Chemist, vol. 4, p. 403, 1874 ; and there is a recent important 

memoir by Semper and Michels, Zeitschr. Berg-, Hiitten- u. Sal.-Wesen preuss. St., 1904, 

pp. 359-482, . .
SALINE RESIDUES. 207

the nitrate beds. A characteristic calichera, in the Atacama Desert, 

50 miles west of Taltal, is described by J. Buchanan a as being made 

up of the following layers :

in.

1-2

Section of typical calichera in Atacama Desert, Chile.

1. Sand and gravel _ . ___ . _ :___ _ _ _ _ _ _ _ _ _ _ __ _ _ ____ _ _

2. " Chusca," a porous, earthy gypsum ___ __ _ _ _ _ ___ _ __ - _ _.. (i

8. A compact mass of earth and stones ___ _ _ _____ _____ _ 2-10

4. " Costra," a low-grade caliche, containing much sodium chloride,

feldspar, and earthy matter- _____ _ _ -___ _ _ . ___ _ _ _ _ 1-8

5. " Caliche." (In the Tarapaca Desert it is from 4 to 12 feet thick). H-2

0. " 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 L. Darapsky,b show. They represent average samples from four different localities.

Analyse,* of caliche from Taltal, Chile.

NaNOa. .......................................................

NaCl...........................................................

!........................................:.. ....................

CaSO<. ........................................................

MgSO<. ........................................................

Na2SO< ........................................................

MgCla.................. ........................................

H8O............................. ...............................

A.

39.44

4.18

.053

3.25

3.97

3.87

45.24

100.003

B.

31.9

8.0

.02

7.0

6.9

8.6

2.4

34.3

99.12

C.

348

41.5

.198

2.9

10.8

1.5

Q 9

100. 898

D.

56.25

2

7c

34.60

fi 0^

.01

99.80

An apparently pure sample of the " saltpeter " from Lautaro had 

the subjoined composition:

Analyse* of " saltpeter " from Lantaro, Chile.

NuNOs -- - -

Cn(NO,)..__..___ _

Mg(NO,) 2 -

MgCl, -_ _ _ _

I : _ __ _ _ ___

_ _ _ 1C>. 24

_ _.. _ 40.09

. . __ 1C. 28

_ . .77

. ._ _ .01

H2O 25 40

_ _ 1.22

100. 01

In these analyses no potassium salts appear; but in the examples 

given by L'Olivier from 2.44 to 8.55 per cent of potassium chloride 

is reported. It is to be expected that widely separated beds should 

differ in composition materially.'

« Jour. Soc. Chem. Ind., vol. 12, p. 128, 1893. See also B. Simmersbach aijd F. Mayr, 

Zeitschr. prakt. Geol., 1904, p. 273.

"Das Departement Taltal (Chile), pp. 136, 139, 142, 163, Berlin, 1900.
208 THE DATA OF GEOCHEMISTRY.

Anhydrite, gypsum, thenardite, mirabilite, bloedite, epsomite, glauberite, and salt are associated with the nitrates, and also the four 

following more unusual species:

Darapskite___-___________________.NaNO.,.Na2 SO4 .H2O.

Nitroglauberite_________________J_.6NaNOo.2Na-SO4.3HjO.

Lautarite__________v _______.___CaL-O,,. 

Dietzeite_______________________.7CaI2O(i .8CaCrO4 .

The lautarite and dietzeite are remarkable as the first definitely 

known iodates to be found in the mineral kingdom, although A. A. 

Hayes ° 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 Avhose origin it is difficult to understand. 

Bromine is generally believed to be absent from the nitrate beds, but 

A. Muntz B claims to have found it, in the form of bromates, in the 

mother liquors from which the saltpeter had crystallized out. Furthermore, in recent years considerable quantities of perchlorates, running in exceptional cases as high as 6.79 per cent of KC1O4 , have been 

discovered in Chilean nitrates. 0 Finally, these nitrates always contain some borates, perceptible traces of rubidium and lithium, but 

probably no caesium/ The borates may be small in amount, but it is 

doubtful whether they are ever quite absent.

The nitrate beds of South America are not entirely confined to 

Chile, although the Chilean deposits outrank all others in importance. The locality at Salinas Grandes, Argentina, has already been 

noticed in connection with -its borates, and the niter there seems to 

be in entirely subordinate quantities. In the Argentine Territory 

of Santiago del Estero, according to W. F. Reid,e 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 f 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/ 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:

0 See ante, p. 201.

6 Ann. chim. phys. 6th ser., vol. 11, p. 121, 1887.

c B. Sjollema, Chem. Zeitung, vol. 20, p. 1002, 1896. As the perchlorates are helieved to 

injure the nitrate as a fertilizer, a voluminous discussion over their detection and effects 

has appeared in the agricultural journals.

<' L. Dieulafait, Corapt. Rend., vol. 98, p. 1545, 1884.

« Tour. Soc. Chem. Ind., vol. 19, p. 414, 1900.

f Berg. u. Hiittenm. Zeitung, vol. 55, p. 391, 1896. Two analyses are given.

o Compt. Rend., vol. 99, p. 84, 1884.
SALINE RESIDUES. 209

Analysis of nitrate deposit near Cochabamba, Bolivia.

KNO3 ___________________________________._______ 60. 70

Na2B4OT ________________________________,._ _______ 30. 70

NaCl___________________________i_____ trace 

N20_________i__'____-__...___________ 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. C. 

Noellner,0 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 6 are 3,800 meters above sea level, 

and 180 miles from the coast, and other localities present similar 

difficulties of distance and elevation. The plain of Tamarugal, 

studied by W. Newton,0 lies between the coast range and the Andes, 

3,000 feet above the sea, and the nitrate beds have peculiarities which 

seem to preclude either an oceanic origin or a derivation from guano. 

Here, at least, bromides are absent, and only traces of phosphates- can 

be found. Sea water would yield the former; from guano the latter 

would remain. Newton regards the nitrates as originally formed by 

the oxidation of organic matter in alluvial soil. Tropical floods, 

which cover the plain once in every seven or eight years, bring upon 

it the concentrated fertility of thousands of square miles and sweep 

the deposits to the landward side of the coast chain, where they are 

mainly found. This is Newton's view, although he admits the possibility that electrically generated atmospheric nitrates may also be 

present. The same possibility is recognized by Semper and Blanckehhorn, but rejected by A. Muntz,d 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,6 who finds in guano the source

" Jour, prakt. Chemie, vol. 102, p. 459, 1867.

6 See E. Semper and M. Blanckenhorn, Zeitschr. prakt. Geol., 1903, p. 309. 

o Jour. Soc. Chem. Ind., vol. 19, p. 408, 1900. See also an earlier paper In Geol. Mag., 

1896, p. 339.

"Ann. chim. phys., 6th ser., vol. 11, p. Ill, 1887. 

0 Ann. mines, 9th ser., vol. 5, p. 50, 1894.

14399 Bull. 330 08 14
210 THE DATA OF GEOCHEMISTRY.

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,a 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. .

That the nitrate beds are proximately derived from the evaporation 

of saline waters is beyond a doubt, but the evidence is strongly against 

their having a marine origin. 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 hot 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,

"Zeitschr. prakt. Geol., 1893; p. 217; 1901, p. 237; 1904, p. 242. Zeitschr. Deutsch. 

geol. Gesell., 1888, p. 153. Ochsenius's work, Die Bildung dcs Natronsalpeters aus Mutterlaugensalzen, Stuttgart, 1887, I have not been able to see. His controversial papers, 

as cited above, give a complete exposition of bis views.
SALINE RESIDUES. 211

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.0 It may be discarded, but it should at least be 

thoroughly investigated. ' .

THE AI/UMS.

One more class of saline residues remains to be mentioned. Waters 

containing sulphates of iron or aluminum form deposits .of these 

salts, which may be neutral or basic, simple or complex. Their formation, however, is very local, and compounds of this character are 

rarely found far from their points of origin.

They are commonly derived, directly or indirectly, from the oxidation of sulphides, and occur as incrustations or even as stalactites, 

around mineral springs, or in the shafts or tunnels of mines. Acid 

solutions, produced by the oxidation of pyrite, act upon aluminous 

rocks and form sulphates of alumina. Alunite and alunogen are 

among the commoner species so generated. Alunogen and halotrichite, the latter a sulphate of aluminum and iron, are found in large 

quantities in Grant County, New Mexico.6 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.

"According to T. Van Wagenen (Min. and Sci. Press, vol. 84, p. 63, 1902), sodium 

nitrate is found in and around an extinct hot spring at the foot of the Humboldt Sink, 

Humboldt County, Nev.

6 See C. W. Hayes, Bull. U. S. Geol. Survey No. 315, p. 215, 1907.
CHAPTER VIII. 

VOLCANIC GASES AND SUBLIMATES.

GASEOUS EMAHATIONS.

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. -

By far the most abundant of the volcanic gases is water vapor or 

steam. It probably forms at least 99 per cent of the entire gaseous 

output, but it soon condenses to liquid and is added or restored to the 

hydrosphere. F. Fouque,ft observing one of the many parasitic cones

0 See A. Geikie, Text-book of Geology, 4th ed., p. 266. I have not found the original 

source of this citation. It should be noted that Brun, whose work is cited later in this 

chapter, regards water as of minor importance among the volcanic emanations.

212
VOLCANIC GASES AND SUBLIMATES. 213

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 annually emit, and its proximate origin may well 

be a subject for speculation. To this theme we shall return presently.

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.0 

Many other substances are found among volcanic exhalations and are 

deposited as sublimates around vents and fumaroles. Let us consider 

the true gases first in order, noting in advance that the materials 

analyzed were dried to eliminate the overwhelming 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.6 From among his analyses of 

volcanic gases the following examples are selected:

. Analyses of volcanic gases from Iceland.

A. From a fumarole in the great crater of Hekla.

B. Prom a fumarole in tbe 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.

IMn

Os.. .................................................

Hs.. .................................................

CO».................................................

HjS..... ............................................

SOa ............. ....................................

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

472

79.07

15.71

100.00

E.

0.72

25.14

50.00

24.12

99.98

The water condensed from the fumaroles of Hekla carried a little 

hydrochloric acid, but in amounts too small for determination.

Among the sublimates formed by these fumaroles, Bunsen noted 

sulphur and various metallic chlorides, especially common salt. One 

sublimate, however, contained 81.68 per cent of ammonium chloride.

Because of their accessibility the Italian volcanoes have been 

studied with peculiar thoroughness, and with regard to their gaseous 

exhalations the data are most abundant. In 1856 C. Sainte-Claire 

Deville ° published a description of the fumaroles found on Vesuvius

0 The two fluorine compounds are reported by A. Scacchi from Vesuvius, Catalogo del 

mineral! vesuviani, Naples, 1887. See also E. S. Dana, System of Mineralogy, 6th ed., 

p. 169.

* Ann. chlm. phys., 3d ser., vol. 38, p. 215, 1853. For these analyses and others, see 

pp. 260-266. An earlier, classical memoir by Elie de Beaumont, entitled " Emanations 

volcanlque^ et metalliftres," appeared in Bull. Soc. geol., 2d ser., vol. 4, p. 1249, 1847.

"Bull. Soc. geol. France, 2d ser., vol. 13, p. 606, 1855-56; vol. 14, p.'254, 1856-57. .
214 THE DATA OF. GEOCHEMISTRY.

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 oh 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 ° 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:

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 

names.

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.

"Ann. chim. phys., 3d ser., vol. 52, p. 5, 1858.
VOLCANIC GASES AND SUBLIMATES. 215

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

so..................................................

HsS......... ........................................

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

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

-

A.

39.13

10.10

50.77

100.00

B.

27.50

14.02

58.48

100.00

C.

69.6

5.5

24.9

100.0

D.

6.4

83.1

.7

Q 8

100.0

E.

86.0

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. Prom the Lake of Palici. B. From the Salinelle of Paterno. 

luba de Xirbl. D. From the Macaluba de Gir'genti.

C. From the MacaCOj............................................................

0»...........................................'.... '..............

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

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 f umaroles 

at different' points vary Avith their distance from the volcanic center. 

In both cases the order of variation is the same.

In 1865 F. Fouque a studied the Italian field with special reference 

to the exhaled gases. In the crater of Vulcano he examined three 

f umaroles, at different temperatures, with results as follows:

Analyses of gases from fum,aroles at different temperatures, Vulcano. . 

A. Temperature above 350°. B. Temperature 250°. C. Temperature 150°.

HC1+SO......... ........................................................

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

0,................,.....................................:.................

K*.. .......... ............................................................

-

A.

73.80

23.40

.52

2.28

100.00

B.

66.00

22.00

2.40

9.60

100.00

C.

27. 19

59.62

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.

"Conipt Rend., vol. 61, pp. 210, 421, 564, 754, 1865.
216 THE DATA OF GEOCHEMISTRY.

ferric chloride, and ammonium chloride were deposited. Another 

group of fumaroles, at a temperature, of 100°, gave deposits of sulphur, sometimes with and sometimes without boric acid. Their 

composition is given below, under D and E.

Analyses of gases from fumaroles, Vulcano.

HCl... ...................................................................

H&.. .............. ....................................... ..........

C0»............ .......................................................... o2 .. .............................:........................................

Hi......:.................. ...............................................

D.

7.3

10.7

 68.8

2.7

11.2

a 100. 7

E.

trace

63.59

7.28

29.13

100.00

F.

17.55

77.02

.70

4.73

100.00

"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.0 The temperature of the fumarole is given as 

86° C. Fouque's analyses of gases from two small solfataras at 

Pozzuoli, near Vesuvius, also indicate a relationship betw.een composition and temperature.

Analyses of yases from Pozzuoli.

H2S... ......................................... .........:.....................-.......

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

Ot .. ................................................................................

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

G (temperature 

96°).

11.43

56.67

5.72

26.18

100.00

H (temperature 

77.5°).

15.09

15.51 er.40

: o.oo

An elaborate examination of the gases emitted by Etna during several eruptions led O. Silvestri6 to conclusions much like those reached 

by Deville and Leblanc, and he described 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

a See note by Deville, Compt. Rend., vol. 61, p. 567, 1865. For recent analyses of gases 

from Italian volcanic sources, see R. Nasini, F. Anderlini, and R. Salvador!, Gazz. chim. 

ital., vol. 36, fasc. 1, p. 429, 1906.

6 1 fenomeni vulcanic! presentati dell' -Etna, etc., Catania, 1867. The data here given 

are from an abstract by G. vom Rath, Neues Jahrb., 1870, pp. 51, 257. See also the great 

monograph, " Der Aetna," by Sartorius von Waltershausen and A. von Lasaulx, 2 vols., 

Leipzig, 1880. " ^
VOLCANIC GASES AND SUBLIMATES. 217

O2 , 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 ........................................................ ..;........

Na2C03 ..................................................................

Na2SO< ........................................;......................... Hao..................................................... :................

50.19

.60

11.12

1.13

30.76

100.00

03.02

.27

6.49

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 atacaniite and tenorite, the latter, obviously, by oxidation.

2. Ammonium-chloride fumai'Ole.s, 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 .... ..............................................................................

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

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

H2 S. ................................................................................

77.28

17 97

5.00

.45

100.00

79.07

1Q Q7

1.61

.35

100.00

Although the observations made by T. Wolf" 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 Avas studied, is the same as that noted in the'volcanoes of the 

Mediterranean.

In his great monograph on the volcanic eruptions of Santorin,6 

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 Kameni, one

a Neues Jahrb., 1878, p. 168.

6 Santorin et ses eruptions, Paris, 1879, 4°.
218 THE DATA OF GEOCHEMISTRY.

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 KamSni,. 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 ...... ......................................................

Hi.............................................................

CH4 ... .........................................................

02 ............;................................................

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

A.

36.42

29.43

.86

.32

32.97

100.00

B.

. 50.41

16.12

2.95

.20

30.32

100.00

C.

0.22

56.70

.07

21. 11

21.90

100.00

D.

1.94

1.00

a24.94

72.12

100.00

0 25.94 in table, but corrected in list of errata at the end of the volume.

Gas C was a true explosive mixture, which detonated violently upon 

contact with a flame. In collecting it special care was taken to avoid

an admixture of air; its oxygen, therefore, is not from extraneous

sources. It is possible, however, that both the oxygen and the hydrogen in this instance came from the decomposition of sea water in contact with hot lava, although Fouque believed that they were 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, 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.
VOLCANIC GASES AND SUBLIMATES. 219

Analyses of volcanic gases from Santorin.

A. Gas taken May 4, 1866, from the bottom of a fissure on Nea Kame'ni. 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 Kame'ni, March 9, 1867.

SLtS. ............................. :.....:............

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

Oi.......................... .........................

Ns........ .......................................... CH<...... .......... :.................................

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.

none

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 ia represented by 

hydrogen, and the acid products- were less completely examined.

For other volcanic regions the data relative to gaseous exhalations 

are unfortunately very meager. Our list must close with three analyses by H. Mpissan a of gases from West Indian fumaroles, which are 

interesting on account of the determinations of argon. The analyses 

are as follows:

Analyses of gases from West Indian fiimaroles.

A. From a fumarole on Mont Pele"e, 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.

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

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

CH.......................................................................

Hs

On........................................................................

Ns................................. ......................................

A........................................................................

HC1. .....................................................................

H2S .......................................................................

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

.08

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 Pelee emanation, which emphasizes the

Compt. Rend., vol. 135, 1902, p. 1085, and vol. 138, 1904, p. 936.
220 THE DATA OF GEOCHEMISTEY.

observations made by W. Libbey a 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. Janssen6 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; ° others result 

from decompositions of volatile matter; and still others are generated 

by reactions between different gases. For example, sulphur may be 

directly sublimed; it may be formed by the decomposition of hydrogen sulphide, or by the partial oxidation of that compound; and it is 

precipitated from mixtures of hydrogen sulphide and sulphur dioxide, two compounds which can not exist together. When they are 

commingled, sulphur is set free. By either of these processes volcanic sulphur can be deposited; but only the first is strictly a sublimation that is, the volatilization and recondensation of a substance 

without chemical change. It is perhaps permissible, however, to use 

the term sublimate a little more loosely, for rigidly accurate discrimination is not practicable in the present instance. Any solid, then, 

deposited by or from volcanic gases, may be regarded conventionally 

as a sublimate.

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,* to the extent of 0.17 per 

cent; and A. Cossa e report's it as present in some of the soluble salts 

which are formed stalactitically in the crater of Vulcano. The lastnamed locality has been studied with more than ordinary thoroughness, and among its fumarole deposits, which are partly sublimates0 Am. Jour. Sci., 3d ser., vol. 47, p. 372, 1894. 

6 Compt. Rend., vol. 64, p. 1303, 1867 ; vol. 97, p. 601, 1883.

c For example, ammonium chloride, which, when vaporized, is dissociated into NHa + 

HC1. .,

" E. Divers and T. Shimidzu, Chem. News, vol. 48, p. 284, 1883. 

e Zeitschr. anorg. Chemie, vol. 17, p. 205, 1898.
VOLCANIC GASES AND SUBLIMATES. 221

and partly secondary products, A. Bergeat ° names realgar, boric acid, 

sodium chloride, ammonium chloride,6 ferric chloride, glauberite, 

lithium sulphate, sodium sulphate, alum,c hieratite,*1 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 G 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 f and G. Freda.*7 These salts, however, are 

interpreted by F. Henrich h 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 .HaO, and erythrosiderite, K2FeCl5 , are derived, and 

also hematite; while copper chloride yields the oxide, tenorite; chlorothionite, K2 SO4 .CuCl2 ; dolerophanite, Cu2 SOr,; and cyanochroite, 

K2Cu(S04 ) 2 .6H2 0; with some hydrous chlorides and oxy chlorides. 

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 

fluor spar, 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 i among the fumarole 

products of Mont Pelee. Sodium carbonate is also produced in a 

secondary way; Silver was discovered by J. W. Mallet i in volcanic 

ash from Cotopaxi and Tunguragua; and it is quite probable that 

this metal, which volatilizes readily, was ejected as vapor. Silver

"Die Aeollschen Inseln : Abhandl. Math.-phys. Classe, K. bayer. Akacl., vol. 20, Abth. 

1, p. 193, 1899.

b Containing, according to Deville and Leblanc (Ann. chim. phys., 3d ser., vol. 52, p. 5, 

1858), also iodide.

c Potash alum, containing oesium, rubidium, and tballium. A. Cossa, Atti Accad. 

Lincei, 1878, pt. 2, p. 34.

rt Potassium silicofluoride, K2SiF8. A. Cossa, Compt. Rend., vol. 94, p. 457, 1882.

" Compt. Rend., vol. 142, p. 1249, 1906. See also H. .T. .Tohnston-Lavls, Nature, May 

31, 190G. In Bull. Soc. Min., vol. 30, p. 219, 1907, Lacroix has described the minerals 

of the Vesuvian fumaroles in considerable detail.

t Abstract in Zeitschr. Kryst. Min., vol. 41, p. 276, 1906. Casoria found molybdenum, 

bismuth, copper, and zinc in Vesuvian salts.

a Gazz. chim. ital., vol. 19, p. 16, 1888.

" Zeitschr. angew. Chemie, vol. 19, p. 326, 1906; vol. 20, p. 179, 1907.

* Bull. Soc. min., vol. 28, p. 60, 1905. Lacroix (Compt. Rend., vol. 144, p. 1397, 1907) 

has recently discovered a double sulphate of potassium and lead among the fumarole 

products of Vesuvius. This new mineral is named palmierite.

i Proc. Roy. Soc., vol. 42, p. 1, 1887 ; vol. 47, p. 277, 1889-90.
222 THE DATA OF GEOCHEMISTRY.

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 a 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," in 1875, found 

silvery incrustations of an iron nitride, Fe5N3 , on an Etna lava, and 

conducted a. series of experiments to determine its origin. Fragments 

of lava were first heated in gaseous hydrochloric acid, when water 

was expelled, silica was liberated, and chlorides of iron were formed. 

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/ 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 portioji 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 O. Rosenbach,6 who argues that it 

may be generated by reactions between atmospheric nitrogen arid hot.

. « Compt. Rend., vol. 143, p. 727, 1906.

"Idem, p. 921.

" Gazz. chim. ital., vol. 5, p. 301, 1875 ; Pogg. Annalen, vol. 157, p. 165, 1876.

A Ber. Deutsch. chem. Gesell., vol. 39, p. 3530, 1906 ; Chem. Zeit, vol. 30, p. 740, 1906; 

C.entralbl. Min. Geol. Pal., 1907, p. 161. See also R. V. Matteucci, Centralbl. Min. Geol. 

Pal., 1901, p. 45, on ammonium chloride in the crater "of Vesuvius.

« Natur. Wochenschr., vol. 21, p. 740, 1906.
VOLCANIC GASES AND SUBLIMATES. 223

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 ° 

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 qr.ite easily^ and magnesia with less facility. P. Schiitzenberger * has observed that silica gradually loses weight in a good wind 

furnace, whose temperature is far below that of the electric arc; and 

E. Cramer c 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 A 

has observed that' at 1,200° silica appears to have an appreciable 

tension. According to A. L. Day and E. S. Shepherd,6 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/ for example, 

reports leucite, augite, hornblende, mica, sodalite, microsommite, cavoliriite, 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.g 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

0 La four electrique, pp. 32-49,- Paris, 1897. See also Compt. Bend., vol. 116, p. 1222, 

1898.

6 Compt. Rend., vol. 116, p. 1230, 1893.

0 Zeitschr. angew. Chemie, 1892, p. 484.

o Compt. Rend., vol. 138, p. 243, 1904.

« Science, vol. 23, p. 670, 1906.

'Zeitschr. Deutsch. geol. Gesell., vol. 24, p. 493, 1872. Condensed from the Italian 

original by J. Roth. See also G. vom Ratb, Neues Jahrb., 1866, p. 824, on augite as 

a fumarole product. H. Traube (Centralbl. Min. Geol. Pal., 1901, p. 679) has described 

the artificial production of minerals by sublimation.

"3,900° to 4,000° absolute. See C. W. Waidner and G. K, Burgess, Bull. Bureau of 

Standards, vol. 1, p. 109, 1904.
224 THE DATA OF GEOCHEMISTRY.

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.* 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 hot determine with absolute certainty the origin 

of volcanic gases, the subject is not entirely unsuited to scientific discussion. Some evidence exists, and from it some conclusions may be 

legitimately drawn. It has long been known that nearly if not quite 

all rocks, upon heating to redness, give off' large quantities of gas a 

fact which was noted by Priestley as early as 1781.& 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." 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 CO2 , 

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,* and marsh 

gas, which Bunsen e extracted from the rock salt of Wielieczka. In

0 J. Joly (Proc. Roy. Irish Acad., 3d ser., vol. 2, p. 38, 1891) 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.

6 See his letters to Josiah Wedgwood, in Scientific Correspondence of Joseph Priestley, 

edited by H. Carrington Bolton, New York, 1892, privately published.

c See especially W. N. Hartley, Jour. Chem. Soc., vol. 29, p. 137, 1876; vol. 30, p. 237, 

1876. G. W. Hawes, Am. Jour. Sci. 3d ser., vol. 21, p. 203, 1881. A. W. Wright, idem, 

p. 209. '

d See B. J. Harrington, Am. Jour. Sci., 4th ser., vol. 19, p. 345, 1905.

e Ann. chim. phys., 3d ser., vol. 38, p. 269, 1853.
VOLCANIC GASES AND SUBLIMATES. 225

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 possible. The observations of W. Ramsay and Mi W. Travers a are also 

interesting, for in zircon they found both argon and helium, and the 

latter gas was yielded by a number of other rare-earth minerals and 

also uraninite, all obtained from pegmatite veins.

In 1876, in the course of his investigations upon the gases evolved 

from meteorites, A. W. Wright 6 found that a specimen of trap, 

heated to redness, gave off three-fourths of its volume of gas, which 

contained 13 per cent of carbon dioxide, the remainder being chiefly 

hydrogen. In 1896 W. A. Tilden ° made a, similar observation upon 

the red Peterhead granite. This rock gave off 2.61 times its volume 

of gases, containing 24.8 per cent of CO2 and 75.2 per cent of hydrogen. A year later d 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 roclcs.

Rock. 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

N2 .

5.13 

1.90 

1.16 

.56 

1.61

H8.

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 e described a series of experiments upon the 

extraction of gases from various minerals and rocks, which led

0 Proc. Roy. Soc., vol. 60, p. 442, 1896-97. Argon and helium have also been round 

in malacone, a variety of zircon, by E. S. Kitchin and W. G. Winterson (.Tour. Chem. 

Soc., vol. 89, p. 1568, 1906). Many of the_ rare-earth minerals, according to H. Erdmann 

(Ber. Deutsch. chem. Gesell, vol. 29, p. 1710, 1896), contain small quantities of nitrogen.

" Am. Jour. Sci., 3d ser., vol. 12, p. 171, 1876.

c Proc. Roy. Soc., vol. 59, p. 223, 1895-96.

" Chem. News, vol. 75, p. 169, 1897. Proc. Roy. Soc., vol. 60, p. 453, 1896-97.

« Proc. Roy, Soc., vol. 64, p. 130, 1898-99.

14399 Bull, 330 08 15
226 THE DATA OF GEOCHEMISTRY.

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 riongaseous substances. Chlorite, 

serpentine, gabbro, mica, talc, feldspar, and glauconite were studied, 

and in each instance the hydrogen and carbon monoxide that were 

evolved by heating the mineral in vacuo were quantitatively related 

to the ferrous oxide and water which the specimen contained. The 

inference is that these gases were generated by a reaction between the 

ferrous salts, the carbon dioxide, and the water of the original silicates. Unfortunately, Travers's conclusions can not be directly 

applied to Tilden's work, for the latter gave no analyses of the rocks 

themselves. It is noticeable, however, that the largest evolution of 

gas cited in Tilden's series was that from the corundum gneiss of 

Seringapatam, and not from the presumably more highly ferruginous 

pyroxene gneiss and basalt. The yield of gas from beryl was also 

very considerable, a fact which Travers's observations do not explain. 

That molten glass absorbs combustible gases, probably hydrogen, was 

observed by H. Sainte-Claire Deville and L. Troost.® 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.o B. Hannay 6 to absorb oxygen and carbon dioxide. 

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 c 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 yranite heated to J.00° 'With phosphoric acid.

HCl and SiF4 .......................................................................

H2S. ................................................................................

COt................. ................................................................

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

A.

1.33

272.6

12.3

53.05-

232. 50

571.78

B.

 22.7

237.5

5.3

191.48

102.48

559. 40

a Compt. Rend., vol. 57, p. 965, 1863.

b Chem. News, vol. 44, p. 3, 1881. A. A. Campbell-Swinton (Chem. News, vol. 95, p. 

134, 1907) 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.

c Compt. Rend., vol. 131, p. 647, 1900; vol 132, pp. 58, 189, 1901; vol. 136, p. 16, 

1903. Ann. chim. phys., 7th ser., vol. 22, p. 97, 1901.
VOLCANIC GASES AND SUBLIMATES. 227

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 800° with water.

H&...... ...............................................................................

COa.... ................................................................................. H2 ............................ ;.........................................................

NS :.....................................................................................

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 Avater 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 vaciio, powdered rocks emit much more gas, and the volcanic 

phenomena are imitated even more closely. In the subjoined table 

A, B, and C are analyses of gases thus extracted from the granite 

of Vire; D represents a granitoid porphyry, E an ophite, and F 

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.

co,...:...... .............................

HSS...... .................................

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

CH<. ......................................

H2 . .......................................

Nj (with argoi^ ..........................

A.

14.80

4.93

2.24

77.30

.83

100. 10 

2,709

B.

8.98

1.71

5.12

1.09

82.80

.42

100. 12 

4,209

C.

14.42

.69

5.50

1.99

76.80

.40

99.80 

2,570

D.

59.25

4.20

2.53

31.09

' 2.10

99. 17 

2,846

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

trace

99.54 

5,450

Before heating, these rocks were dried at 250° to 300° to remove 

hygroscopic moisture. The volume of gas extracted from one volume 

of rock amounted to 6:7 from the granite, 7.6 from the porphyry, 7.6 

from the. ophite, and 15.7 from the Iherzolite. The granite, it will be 

seen, gives the smallest evolution of gas per volume of material, but 

it is by far the richest in hydrogen. Even in this case, according to 

Gautier, a cubic decimeter of granite at 1,000° would give, calculated 

for that temperature, about 20 liters of mixed gases and 89 liters of 

steam more than one hundred times its initial volume.

In order to prove that the gases are not simply inclosed in the 

rocks, Gautier extended his experiments along several lines. First, 

he argued, inclosed gases should not vary in composition during the 

process of extraction, whereas gases generated by heat might do so. 

The latter condition held in the case of granite when two fractions of 

the gas were examined separately. The analyses are as follows;
228 THE DATA OF GEOCHEMISTRY. 

Analyses of gas evolved from granite.

coa.... :...........................................................................

HjS.'. .............................................................................

CO.......................:........................................................

CH4 .. .............................................................................. Hz...........................:.....................................................

Ns-... .............................................................................

First 

third.

20.19

1.28 -.57

2.04

75. .64

.30

99.92

Last twothirds.

6.13

.41

1.02

.80

91.64

.30

100.30

A similar variation was exhibited during the evolution of gas from 

ophite.

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 TO cubic centimeters 

of gas were developed, having, after the removal of carbon dioxide, 

the subjoined composition:

CO __--_-__ ___-___.____________________ 3. 32

CH4 _.________-__-_____.___-__-____________________ 6.08

H2 :_________T _________________ _ ________ 36. 20 

N2, etc .-'_ ' _______________________ 54. 20

99. 80

This gas was certainly not preexistent in the rock, for that had been 

previously exhausted, and yet it was moderately rich in hydrogen.

Gautier's conclusions were, in the main, confirmed by K. Hiittner.a 

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 CO2 on ferrous silicates, he 

showed that it can be produced by the reducing action of the liberated 

hydrogen upon C02 . Rocks containing more or less water were 

heated in a stream of carbon dioxide, when both hydrogen and carbon monoxide were given off.

That such a reduction was possible had long been known; but Gautier,6 in a later investigation, studied the reaction much more thor0 Zeitschr. anorg. Chemie, vol. 43, p. 8, 1905.

6 Compt. Rend., vol. 142, p. 1382, 1906; Bull. Soc. chim., 3d ser., vol. 35, p. 929, 1906, 

Gautier gives references to earlier literature,
VOLCANIC GASES AND SUBLIMATES. 229

oughly and found that it was reversible. At a white heat the reaction is as follows:

CO2 +3H2 =CO+H2 0+2H2 .

At temperatures between 1,200° and 1,250°, on the other hand, the 

equation becomes 

3CO+2H2 0=2C(X+2H2+CO.

. The coexistence of Avater vapor, hydrogen, and both oxides of carbon 

in volcanic emanations thus becomes intelligible. When water emitted by heated rocks mingles with carbon dioxide from any source 

whatever, Avithin the vent of a volcano, both reactions take place, and 

mixed gases, which sometimes contain traces of formic acid, are generated. This mixture is a pOAverful 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 still further, Gautier a investigated the reactions between 

steam and the metallic sulphides. At incipient redness steam changes 

the iron sulphide, FeS, into magnetite, Fe3 04 , with formation of free 

hydrogen and hydrogen sulphide. Galena, in a current of superheated steam, was partly sublimed and recrystallized as such b 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 Avas liberated and a mixture of hydrogen Avith sulphur dioxide Avas formed. The same gaseous mixture 

Avas 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 c 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 Avhite heat hydrogen sulphide reconverts magnetite into 

FeS, and a mixture of sulphur dioxide with hydrogen is generated. 

Hydrogen sulphide may also react Avith 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 Avater, carbon dioxide, and the solid constituents of lavas. Many of these reactions are reversible, and they give rise to nearly all the gaseous mix0 Compt. Rend., vol. 142, p. 1465, 1906; Bull. Soc. chlm., 3d ser., vol. 35, p. 934, 1906. 

6 This recalls the existence, already mentioned, of galena as one of the Vesuvlan sublimates.

" Compt. Rend., vol. 143, p. 7, 1906; Bull. Soc. chlm., 3d ser., vol. 35, p. 939, 1906.
230 THE DATA OF GEOCHEMISTRY.

tures 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 general memoir, recently published, Gautier ° 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,6 

who attributes volcanic activity to the action of water upon metallic 

carbides, although these compounds are not seen as "natural products 

on the surface of the earth. Water, acting upon the artificial carbides, develops hydrogen and hydrocarbon gases; the latter, through 

the influence of heat, partly polymerize to liquid or solid compounds 

and partly burn, yielding carbonic acid and water; and so the observed order of evolution seen in volcanic eruptions is paralleled. This 

view also finds some support in the observations of O. Silvestri,0 who

0 Ann. mines, 10th ser., vol. 9, p. 316, 1906. Compare F. Loewinson-Lessing (Compt. 

Rend. VII. Cong. ge"ol. internat., p. 369, 1897), who attributes volcanic gases to the 

absorption of sedimentary rocks by magmas. Clays yield water, limestones furnish 

C02, etc.

» Proc. Roy. Soc., vol. 60, p. 156, 1896-97. See also E. Steelier, 14. Ber. Natur. Gesell. 

Chemnitz, 1900; A. Rossel, Arch! sci. phys. nat., 4th ser., vol., 14, p. 481, 1902; and H. 

Lenicque, Me"m. Soc. inge"n. civils, France, October, 1903, p. 346.

c Gazz. chim. ital., vol. 7, p. 1, 1877.
VOLCANIC GA&ES Atfb SUBLIMATES.

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.

In strong contrast with Gautier's conclusions are the views advanced by A. Brun,0 who 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-sijicates, such as the compound Ca2Cl2Si03 , which he

artificially prepared. b 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 1,1.00°. Temperature of explosions.

1,100°. Mean temperature of flowing lava. ' 

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.

As between Brun and Gautier, the work of the latter 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."

"Arch. sci. phys. nat, 4th ser., vol. 19, pp. 439, 589, 1905. For a popular summary of 

his own work, with a criticism of Brun, see Gautier, Revue scientlflque, 5th ser., vol. 8, 

p. 545, 1907.

6 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.

0 Cf. A. Daubrfie, fitudes syntb.e"tiques de geologic expe"rimentale, pp. 235-241, 1879.
232 THE DATA OF GEOCHEMISTRY.

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 determinate 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. Beyer,ffi by S. A. Arrhenius,& and also, more recently, by C. 

Doelter,6 who regards the deep-seated magmas as impregnated by 

gaseous mixtures, which explode upon relief of pressure. The consideration of these gases, moreover, 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 d 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

0 Beitrag zur Fysik der Eruptionen, Wien, 1877.

6 Geol. Foren. Forhandl., vol. 22, p. 411, 1900.

c Sitzungsb. Akad. Wien, vol. 112, p. 681, 1903.

<* Geology, vol. 1, pp. 588-594, 602-618, 1904. See also ante, Chapter II, p. 52. 

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. Geol., vol. 14, p. 138, 1906.
VOLCANIC GASES AND SUBLIMATES. 233

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 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 ° 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 

Ayater enters the magma, in which it is absorbed 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 ta,ken 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 Daubree, as well 

as many earlier writers, derive them from infiltrations of sea. water, 

Arrhenius assuming osmotic pressure and Daubree capillary attraction as the method by which entrance to the magma was effected. 

Chamberlin regards 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 cer-

"Geol. Foren. Forhandl., vol. 22, p. 411, 1900.
234 THE DATA OF GEOCHEMISTRY.

tainly 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. That is, the presence of such occlusions is not 

completely disproved by Gautier's experiments, and the extent to 

which the theory 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.0 Data relative to the absorption of hydrogen by iron are 

abundant,6 and meteoric iron seems always to contain it. c From the 

Lenarto iron T. Graham obtained 2.85 times its volume of gas, 

containing 86 per cent of hydrogen. From the Augusta iron Mallet 

extracted 3.17 volumes, in which hydrogen, carbonic oxide, carbon 

dioxide, and nitrogen were present. There is, to be sure, one adverse 

experiment by M. W. Travers,d on meteoric iron of unstated origin, 

which is not quite conclusive. By heating this iron, hydrogen was 

obtained; upon dissolving the iron in copper-sulphate solution, none 

was evolved. The failure to develop hydrogen in the second experiment is held by Travers to prove its absence, at least as a gaseous 

occlusion. The possibility that hydrogen, from a metallic hydride, 

might be expended in the precipitation of copper, seems not to have 

been investigated. The weight of evidence, so far, is that meteoric 

irons do occlude hydrogen, while meteoric stones, according to 

Wright, yield chiefly 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,6 

more than one hundred times its volume of gas, which is mainly carbon monoxide with a little dioxide. If Chamberlin's theory of the

n 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, p. 264, 1893. See also references cited by G. Tschermak, Sitzungsb. Akad. Wien, vol. 75, pp. 170-174, 1877.

6 See, for example, L': Trodst and P. Hautefeuille, Compt. Rend., vol. 76, p. 562, 1873; 

L. Cailletet, idem, vol. 61, p. 850, 1865 ; and Thoma, Zeitschr. physikal. Chem., vol. 3, 

p. 91, 1891. Thoma's paper gives many references to literature. H. Wedding and T. 

Fischer (Ber. V. Internat. Kong, angew. Chemie, vol. 2, p. 25, 1904) have summed up the 

subject quite thoroughly. The papers by J. Parry (Am. Chemist, vol. 4, p. 225, 1873-74; 

vol. 6, p. 107, 1875-76) are also important.

«T. Graham, Proc. Roy. Soc., vol. 15, p. 502, 1866-67. J. W. Mallet, idem, voh 20, 

p. 365, 1871-72. A. W. Wright, Am. Jour. Sci., 3d ser., vol. 9, p. 294, 1875; vol. 10, 

p. 44, 1875; vol. 11, p. 253, 1876; vol. 12, p. 166, 1876. J. Dewar and G. Ansdell, 

Proc. Roy. Inst., vol. 11, p. 445, 1886.

A Proc. Roy. Soc., vol. 64, p. 130, 1898-99. :

" Ann. Chem. Pharm., vol. 163, p. 250, 1872. A similar observation by M. Berthelot 

is recorded by A. DaubrSe,' Compt. Rend,, vol. 74, p. 1541, 1872.
VOLCANIC GASES AND SUBLIMATES. 235

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 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,0 

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,6 and they are 

expelled in great measure during solidification. They are, moreover, 

expelled explosively, a fact which can be verified in any laboratory; 

but that the expulsion is complete is extremely improbable. Some 

gas, it may be much or little, is retained by the solid mass, and modifies its properties. All of these elements contribute to the phenomena 

of volcanism, but their relative magnitudes can not now be evaluated. 

Speculation upon them may help to stimulate research, but so long 

as the temperatures and pressures within a volcano are unmeasured 

the problems suggested by the hypotheses must remain unsolved. 

The question of volcanic temperatures, of which more will be said in 

the next chapter, is particularly important in the investigation of 

volcanic explosions. The latter are due in part to cooling and the 

violent expulsion of gases following relief of pressure, but chemical 

combination may also be manifest in them. If the temperature in 

the depths of a volcano is high enough to dissociate water into its

« Sitzungsb. Akad. Wien, vol. 75, p. 151, 1877.

6 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.
236 THE DATA -OF GEOCHEMISTRY.

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,* observing a series 

of explosions at Vesuvius, ascribed them to this cause. That hydrogen does issue from volcanoes is established; under certain conditions 

it burns quietly, and under others it gives rise to explosions; but in 

either case it develops much heat and so retards the cooling'of its 

surrounding matter. One gram of hydrogen, burning to form water, 

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 espe-. 

cially by the labors, of Deville and Leblanc. What, now, in the light 

of all the evidence, is that order, and what do the chemical changes 

mean ?

First. The gases issue from an active crater at so high a temperature that they are practically dry. They contain superheated steam, 

hydrogen, carbon monoxide, methane, the' vapor of metallic chlorides, 

and other substances of minor importance. Oxygen may be present 

in them, with some nitrogen, argon, sulphur vapor, and gaseous compounds of fluorine.

Second. The hydrogen burns to form more water vapor, and the 

carbon gases oxidize to carbon dioxide. From the sulphur, sulphur 

dioxide is produced. The steam reacts upon a part of the metallic 

chlorides, generates hydrochloric acid, and so acid fumaroles make 

their appearance.

Third. The acid gases of the second phase force their way through 

crevices in the lava and the adjacent rocks, and their acid contents 

are consumed in effecting various pneumatolytic reactions. The 

rocks are corroded, and where sulphides occur hydrogen sulphide is 

set free. If carbonate racks are encountered, carbon dioxide is also 

liberated.

Fourth. Only steam with some carbon dioxide remains, and even 

the latter compound soon disappears.

0 Monatsber. K. preuss. Akad., 1878, p. 558.
VOLCANIC GASES AND SUBLIMATES. 237

This seems to be the general course of events, although it is modified in details by local peculiarities. All of the substances enumerated in the lists of gases and sublimates given in the earlier portions 

of this chapter may take part in the reactions, but they do not 

seriously affect the larger processes which have just been described. 

The order is essentially that laid down by Deville and Leblanc, 

except that the early evolution of hydrogen and carbonic oxide is 

taken into account. The current of events may be disturbed, so to 

speak, by ripples and eddies that is, by subsidiary and reversed 

reactions but its main course seems to be clearly indicated.0

a For a recent summary of our knowledge concerning the magmatic gases, see F. C. 

Lincoln, Econ. Geol., vol. 2, p. 258, 1907.
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,* but on the other hand the water that we know to be 

present in the molten mass tends 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, furthermorej 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.6 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.0 The development of the thermo-couple by C. Barus in

a Estimates of the change in fusibility due to pressure have been made by Lord Kelvin, 

Phil. Mag.,.5th ser., vol. 47, p. 66; and C. E. Stromeyer, Mem. Manchester Lit. Phil. 

Soc., vol. 44, No. 7, 1900. The fundamental data, however, are few and unsatisfactory.

6 For estimates of temperatures far within the earth, see Clarence King, Am. Jour. 

Sci., 3d ser., vol. 45, p. 7, 1893; 0. Fisher, idem, 4th ser., vol. 11, p. 414, 1901; F. R. 

Moulton, cited by T. C. Chamberlin, Jour. Geol., vol. 5, p. 674, 1897 ; and A. C. Lunn, in 

Chamberlin and Salisbury's Geology, vol. 1, p. 552, 1904. All the estimates reach- exceedingly high figures.

c See, for example, A. Schertel and T. Erhard, Beiblatter, 1879, p. 347; and Schertel, 

idem, 1880, p. 542. .

238
THE MOLTEN MAGMA. 239

the United States Geological Survey, and by H. Le Chatelier in 

France, and the use of the Seger cones in the ceramic industry, have 

placed high-temperature pyrometry upon a new footing and have 

made practicable the class of determinations which we now require. 

 In 1891 J. Joly a described an instrument (the meldometer) bymeans of which the melting points of minerals could be rapidly and 

easily determined, and several years later R. Cusack l' 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,0 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. Brim d 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 6 in the geophysical laboratories of the United States Geological Survey and the Carnegie Institution upon almost ideally.pure

" Proc. Roy. Irish Acad., 3d ser., vol. 2, p. 38, 1891.

"Idem, vol. 4, p. 399, 1896.

c Min. pet. Mitth., vol. 20, p. 211, 1901 ; vol. 21, p. 23, 1902 ; vol. 23, p. 297, 1903 ; 

Sitzungsb. Akad. Wien, vol. 114, p. 529, 1905 ; vol. 115, abth. 1, July, 1906. The determinations cited are from his third paper.

J Arch. sci. phys. nat, 4th ser., vol. 13, p. 552, 1902; vol. 18, .p. 537, 1904. There 

are also some determinations by W. C. Roberts-Austen, cited by Lord Kelvin, Phil. Mag., 

5th ser., vol. 47, p. 66, 1899; others by J. H. L. Vogt, published In part 2 of his Die 

SilikatschmelzlOsnngen, and a few by W. Hempel, Ber. V. Internat. Kong, angew. Chemie, 

vol. 1, p. 725, 1904. For data on shales and clays, see W. C. Heraeus, Zeitschr. angew. 

Chemie, 1905, p. 49.

« A. L. Day and E. T. Alien, Am. Jour. Sci., 4th ser., vol. 19, p. 93, 1905, on the feldspars. E. T. Alien and W. P. White, Idem, vol. 21, p. 100, 1906, on wollastonite. A. L. 

Day and E. S. Shepherd, idem, vol. 22, p. 265, 1906, on the lime-silica series. E. T. 

Alien, F. E. Wright, and J. K. Clement, idem, vol. 22, p. 385, 1906, on magnesium 

metasilicate.
240 THE DATA OF GEOCHEMISTRY.

artificial minerals, and with thermoelectric couples which had been 

calibrated by comparison with the standards at the Physikalische 

Reichsanstalt at Berlin. In these measurements the melting points 

were determined by noting the exact temperatures at which abrupt 

absorptions of heat occurred, 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 FELDSPATHOIDS.

Mineral.

Albite. ......... .........................

Joly.

1,230

1.220

1,175

Cusack.

1,223-1,235

. 1,172

1,298

1,059-1,070

Doelter.

1,165-1,210

;

1,040-1,210

1,155-1,185

1, 135-1, 185

1, 115-1, 170

1,185-1,220

1,275-1,315

1, 105-1, 125

Brun.

1, 490-1, 520

1, 544-1, 562

1,370

1,280

1,260

1,259

1, 410-1, 430

1,270

Dayetal. (

1

1, 532

1,500

1,463

1,419 f,

1, 367 "

a 1, 340

 Approximate. Viscosity prevents exact measurements.

MISCELLANEOUS MINERALS.

Mineral.

Wollastonite o. . ..................................

CaSi03, artificial .................................

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-i; 220

1, 265-1, 410

1,190-1,225 1 QKA_I Ann

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, 512

 " 1, 375 /

1 

' 600

d 1, 387

a Wollastonite has no true melting point. At 1,180° it passes into the pseudohexagonal 

form, which melts at 1,512°.

6 Hitherto unpublished measurement by Alien and White. A much lower value, 3,225°, 

was given by Vogt.

c More properly silica. Quartz is transformed into 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°. 0. Boudouard (Jour. Iron and Steel Inst., 

1905, pt. 1, p. 350) puts the melting point of silica at 1,830°. Other recent papers on the 

melting points of quartz and silicates are by J. A. Douglas, Quart. Jour. Geol. Soc., vol. 63, 

p. 145, 1907 ; and G. Stein, Zeitschr. anorg. Chemie, vol. 55, p. 160, 1907.

& Hitherto unpublished determination by A. L. Day on the natural mineral.
THE MOLTEN MAGMA. ' 241

i

Many of the published melting! points have no real significance. 

Some of the minerals for which melting points have been recorded 

breakdown 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 oth'er silicates or mixtures of silicates, ' 

whose precise character is unknown. Garnet, when fused, also splits

up into two or more compounds, arid in such cases the recorded melting points are meaningless.

.In his second paper Brun give's the melting point of artificial 

anorthite, as determined by a calorimetric method, at from 1,544° to 

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°. Thej albite glass softens at 1,177°. 

These, lower temperatures accord fairly with those determined by 

Cusack and Doelter, 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. Ojne augite, for example, contains 

much, another little, iron; calcium and magnesium also vary in their 

proportions, and so on. In thescj 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 ofijen entirely absent. The figures 

given, therefore, do not, except in tljose 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 furijiish 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 d!ata should be handled with great 

caution. A comparison of the different figures for the melting point

of the same mineral, say for leucite or olivine, will shoAV how great

the existing uncertainties really are.

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 oiide or silicate melts is the tern-' 

perature at which a mineral of the i|ame composition can crystallize 

from a magma. Many substances exist in more than one modifica14399 Bull. 330 08 16
242 THE DATA OF GEOCHEMISTRY.

tion, 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 Uidymite 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 1,000° ; 

.wollastonite can not exist above 1,180°; 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 Avithin 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,0 will serve to 

illustrate this point:

Melting points (°C.) of various igneous rocks.

Rock. Softens.

1,115-1,125

1,030-1,060

962-970

995-1,000

1,060

1,040-1,060

Becomes 

fluid.

1 190

1,080-1^090

1,010-1,040

1,060 1,075

1,090

1,060-1,100

According to A. Brun,6 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,0 based upon the presence of leucite in 

Vesuvian lava. Doelter, however, assigned to leucite a melting point

«Min. pet. Mitth., vol. 21, p. 23, 1902.

B Arch. sci. phys. nat., 4th ser., vol. 13, p. 367, 1902.

o Sitzungsb. Akad. Wien, vol. 112, p. 681, 1903.
THE MOLTEN MAGMA. 243

which is certainly too low,tt 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 Avhich 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,6 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.

INFLUENCE OF WATER.

So far the measurements cited in this chapter relate to dry fusion 

or to the fusion of minerals containing only insignificant quantities of 

hygroscopic water. Within a volcano, apparently, the conditions 

are quite different, and there the presence of water must be taken 

into account, together with the gases which are so powerfully operative in producing explosions. The magma, before eruption, is something very different from the smoothly flowing stream of lava, for it 

is heavily charged with aqueous vapor and other gases, under great 

pressure, exactly as the soda water in an ordinary siphon bottle is 

loaded with carbon dioxide. When the pressure is released the gases 

escape with explosive force, carrying the liquid matter with them. 6' 

In the eruption of a volcano this process produces a great quantity 

.of fiery spray, which solidifies in the form of volcanic ash, while 

other portions of the foaming surface of the lava cool to pumice. 

When the lava stream itself appears its effervescence has largely 

ceased, and-it exhibits'the ordinary phenomena of a cooling liquid.

The condition of the water which is'Contained within a majrma is O

perhaps best explained by certain experiments of C. Barns/* who 

found that colloid substances, in presence of solvents, swell up enormously, and that at high temperatures the swollen, coagulum passes

"See preceding table of melting points (p. 240). Preliminary experiments by A. L. 

Day have shown that the melting point of leucite is certainly above 1,500°. r

b Text-book of Geology, 4th ed., p. 304.

' This comparison of a volcano with a. bottle of soda water or champagne has been 

developed by S. Meunier. He assumes that the water was originally occluded or combined in the rocks, and when the latter, by displacement, are brought into the region of 

high temperature, their aqueous content is set free and an explosion becomes possible. 

See La Nature, vol. 30, pt. 1, p. 386, 1902.

d Am. Jour. Sci., 4th ser., vol. 9, p. 161, 1900. The name " water glass," as used by 

Barns, is unfortunate, for it already belonged to the soluble alkaline silicates and had 

been in current use for many years.
244 THE DATA OF GEOCHEMISTRY.

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° (J. 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." .

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 wafer are largely expelled, and a 

fluid or viscous lava, very different from the original magma, remains. 

By pressure, furthermore, the temperature needed to produce complete fluidity is raised, and this fact is emphasized by the phenomena 

of resorption. A mineral like quartz, for example may crystallize 

within a viscous magma, but when the pressure is reduced its temperature of fusion falls, and partial or complete re-solution may take 

place. These partly redissolved minerals are familiar objects to the 

petrologist.

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

" Compare P. Guthrie, Phil. Mag., 5th sei1 ., vol. 18, p. 117, 1884, on the change from 

obsidian to pumice by extrusion of water.
THE MOLTEN MAGMA. 245.

which they rest, so far as it touches chemistry, must be briefly 

considered."

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.6 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, Avith 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 con- 

' ditions hold, for as a solution it is dilute with respect to its minor components, but highly concentrated as regards the more essential minerals. As a solution of apatite or rutile it may be very weak; as a 

solution of quartz, feldspar, or pyroxene, very strong. It is, however, a conductor of electricity, and. therefore, if the analogy between 

it and ordinary solutions is valid, it is at least partially ionized. This 

is the view adopted by C. Barus and J. P. Iddings,0 who studied the 

electrical conductivity of three molten rocks, for which the following 

condensed descriptions may be cited here:

Melting points imd silica content of tli,ree igneous rocks.

Rock.

Approxi.

mate

melting

point.

1.250

1,400

1,500

Percentage of

SiO2.

48.49

61.50

7*1 fUl

a For good summaries on uiaginatic differentiation, see .T. P. Iddings, The origin of 

igneous rocks: Bull. Phil. Soc. Washington, vol. 12, p. 89, 1802; W. C. Briigger, Die 

Eruptivgesteine des Kristianiagebietes, pt. 3, p. 834, 1808; and F. Loewinson-Lessing, 

Compt. Rend. VII Cong. geol. internat., p. 308, 1807. 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', Bulli Soc. Min., vol. 25, p. 349, 1002.

6 G. F. Becker (Twenty-first Ann. Kept. U. S. Geol.. Survey, pt. 3, p. 519, 1901) proposes 

to regard the eutectic mixtures as the true solvents, and the minerals which separate 

from them as the solutes. -This suggestion deserves careful consideration, although it 

can not be fully utilized until we know what the eutectics really are. 

 c Am. .Tour. Sci., 3d ser., vol. 44, p. 242, 1892.
246 THE DATA OF GEOCHEMISTRY.

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.a What these ions are we do not yet know; but their ultimate 

identification is not hopeless. The extent of the ionization is also 

unknown, but its existence seems to be established. Furthermore, 

since the several silicates are present in a magma in different degrees 

of concentration, they must be differently ionized, and some of them 

to a much greater extent than others.

When a salt dissolves in water the temperature of solidification 

is changed. Water, for example, freezes at 0° C., but the addition 

of 23.6 per cent of sodium chloride to it reduces the melting or 

solidifying point to - 22°. This depression of the melting point 

is quite a general phenomenon, and from it, by formulae which need 

not be considered here, the molecular weight of the dissolved substance can be calculated. In alloys a similar change can be observed, 

and in some cases it is very striking; the well-known fusible alloys, 

for instance, melt at temperatures below the boiling point of water.

An igneous rock, so far as our data now go, exhibits the same 

peculiarity, and becomes fluid at temperatures below the average 

melting point of its constituent minerals, and sometimes lower than 

the lowest among the latter. Doelter's figures, as cited on page 242, 

serve to illustrate this point, although the depression is not so marked 

as in the more familiar cases just mentioned. The experiments by 

Michaela Vucnik 6 and Berta Yukits,c 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,5 although not rigorously comparable with natural phenomena, point in the same direction. Mixtures of Na2 SiO3 and CaSi03 were studied, the first salt melting at

a The coexistence in certain rocks of antagonistic minerals like quartz and magnetite 

may be an evidence of dissociation. They should react to form a silicate of iron, but 

we can readily imagine a highly viscous melt as solidifying so rapidly that all of the 

ions are unable to find their proper partners. The free oxides therefore appear in the 

solid product. I offer this merely as a suggestion. Doelter (Sitzungsb. Akad. Wien, 

vol. 113, p. 169, 1904) ascribes the early separation of oxides and aluminates from cooling magmas to dissociation.

" Centnilbl. Min. Geol. Pal., 1904, pp. 295, 340, 364.

c Idem, pp. 705, 739.

"Zeitschr. anorg. Chemie, vol. 35, p. 187, 1903.
THE MOLTEN MAGMA. 247

1,007° and the second at a temperature above l,400°.(t 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.

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 1 

one exhibiting its own peculiarities. Between these extremes many 

intermediate conditions are possible, due to partial crystallization 

and 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 noAv 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 

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, NaC1.2H2 0, 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.6 Above the eutectic point either salt or 

water may crystallize out, that substance being first deposited which 

is in excess of the eutectic ratio the ratio, that is, of 23.6 NaCl to 

76.4 H2 0. In the freezing of sea water .the separation of nearly pure 

ice is seen, because the water is largely in excess of the eutectic proportions.

" 1,512° according to Alien and White. See table of melting points (p. 240).

'' If. Outline regarded these saline mixtures with water as definite compounds, which 

he termed cryohyclrat.es. See Phil. Mag., 4th ser., vol. 49, pp. 1, 206, 2G6, 1875; 5th ser., 

vol. 17, p. 462,' 1884. See also M. Koloff, Zeitschr. physikal. Chemie, vol. 17, p. 325, 1895.
248 THE DATA of GEOCHEMISTRY.

When two salts are fused together and allowed to solidify, the samd 

order of phenomena appears, provided that certain conditions are 

satisfied. First, the fused salts must be miscible that is, soluble in 

one another. If this condition is not fulfilled the melt will separate 

into layers. Secondly, they must not be capable of acting upon each 

other chemically, for in that case new compounds are produced. 

Finally, they should not be isomorphous salts, for then no eutectic 

mixture is possible. The feldspars albite and anorthite, for example, 

crystallize together in all proportions, and the melting points of the 

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 conp siderations may be applied to its investigation. Some of its components will form isomorphous mixtures, but a part of it will 

represent eutectic. proportions which differ with the varying composition of different- rocks. In each case the substances that are in excess 

of the eutectic ratios are likely to crystallize first, and the eutectic' 

mixture itself will probably be found in the groundmass, or solidified mother liquor, from which the crystals have separated. From 

this point of view the study of the eutectics becomes fundamentally 

important in the study and classification of igneous rocks, for they 

chiefly determine, the character and order of deposition of the phenocrysts. There are doubtless other factors in the problem, but this one 

is the most fundamental and characteristic. So far none of the 

eutectics in question have been positively identified, although 

various attempts to indicate them are on record, with results 

which may or may not be -verified. In Kultascheff's experiments 

with sodium and calcium silicates two eutectic points were noted, 

which represented, however, not a single natural mixture, but a 

series of artificial mixtures wherein both of the original compounds 

and two double salts took part. H. O. Hofman's work 0 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 & 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,0 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 d was one of the first to develop the subject, and he

0 Technology Quart, vol. 13, p. 41, 1900. 

6 Am. Jour. Sci., 4th ser., vol. 22, p. 265, 1906. 

"Phil. Mag., 4th ser., vol. 49, p. 20, 1875. 

d British Petrography, pp. 395-419, 1888.
THE MOLTEN MAGMA. 249

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,0 

who regards a mixture of 74.25 per cent of orthoclase with 25.75 percent, 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 3AlKSi8O8 : 5Si02 , 

although simple molecular ratios can not necessarily be assumed in 

eutectic mixtures. The latter, so far as present evidence goes, are 

not definite compounds. The water-salt eutectic is not a hydrate, but 

a mixture of salt and ice, which, however, happens to approximate 

rather closely in composition to NaCl+10H2 0.

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 diopsicle with 32 olivine. 

74 melilite with 26 olivine. 

65 melilite with 35 auorthite. 

40 diopsicle with 60 akennanite. 

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. 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 seeks 

to compute the molecular weights of several silicates from the 

observed melting-point depressions, and concludes that they are 

neither polymerized nor considerably disassociated. Their simple, 

empirical formulae, according to Vogt, represent their true molecular weights, and the fused minerals, as such, exist in the fluid magmas. The essential point in Vogt's work is that he attempts to apply 

modern physicochemical methods to the investigation of magmas, and 

whether his 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

"Die Silikatschmelzlosungen, pt. 2, pp. 113-128, 1004. See .also Vogt, Min. pet. 

Mitth., vol. '24, p. 437, 1906; vol. 25, p. 861, 1906; A. C. Lane, .Tour. Geol., vol. 12, p. 

83, 1904; H. E. .Tolinnsson, Gcol. Foren.' Forhandl., vol. 27, p. 11.9, 1.905; and A. 

Bygd6n, Bull. Geol. Inst. TJpsala, vol. 7, p. 1, 1904-5.
250 THE DATA OF GEOCHEMISTRY.

are of like simplicity. But igneous rocks are, as a rule, much more 

complex, and may contain from three to many component minerals. 

For conditions like these the theoretical treatment is as yet undeveloped, although the researches of Van't Hoff on the Stassfurt salts 

.suggest, with their diagrams, certain analogies which may be followed 

in the future. The laws of equilibrium must apply to all possible 

cases of solution, even though we may be unable as yet to. trace the 

details of their working. Just as the Stassfurt problem is complicated 

by the deposition of hydrates and double salts, so from the magma 

complex silicates can form, and the exact conditions under which 

each may develop are so far only partially determined. The difficulties that confront us here are well pointed out by Roozeboom a 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,

0 H. W. Bakhuis Roozeboom, Die heterogenen Gleichgewichte vom Standpunkte der 

rhasenlehre, vol 2, pp. 240 et seq.,-Braunschweig, 1904. For a simple application of a 

phase-rule diagram to a system of two components, see W. Meyerhoffer, Zeitschr. Kryst. 

Min., vol. 36, p; 592, 1902. T. T. Read (Econ. Geol. vol. 1, p. 101, 1005) has discussed 

the application of the phase rule to the study of magmas, but his suggestions have been 

criticized by A. L. Day and E. S. Shepherd (idem, p. 286). C. Doelter (Min. pet. Mitth., 

vol. 25, p. 79, 1907) has studied what he calls the "stability fields" of certain minerals.
THE MOLTEN MAGMA. 251

cooling on the surface of the earth, will behave vei-y 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. At the surface quartz is likely to separate early 

from the magma; in a deep-seated granite it may be the last mineral 

to appear. There again we touch the question of aqueo-igneous 

fusion, which can be effected only under pressure. 

If in any given case we regard the eutectic mixture as the solvent,

the minerals that are in excess of its ratios will be the first to 

crystallize. Their, order of ^deposition .will then depend upon three 

essential conditions namely, their relative abundance,0 their solubility iii thlT eutectic, and their points of fusion. Other things being 

equal, the less soluble and less, fusible substances will be formed 

earliest. With an excess of alumina, corundum and spinel may form, 

and as a general rule the so-called accessory minerals, the more 

trivial constituents of a rock, are among the first separations. 

Apatite, sulphides, and the titanium minerals belong in this class. 

Although the sulphides are more easily fusible than the silicates, 

their insolubility in a silicate magma causes their early precipitation. 

According to J. H. L. Vogt,6 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 ° has 

shoAvn 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

" F. Loewinson-Lessing (Compt. Rend. VII Cong. gfiol. internal, pp. 352-353, 1897) 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, pp. 96-101, 1903. ?J

"Min. pet. Mitth., vol. 18, pp. 56, 57, 1888-89.
252 THE DATA OF GEOCHEMISTRY.

presence of certain species impossible. In an actual magma these incompatibilities do not exist, nor do they become evident when we 

fuse together several oxides to form an artificial melt. When, 

however, we fuse mixtures of minerals, as in the researches of J. 

Lenarcic,® M. Vucnik,6 and B.- Vukits," the limitations of this class 

become evident. For instance, when magnetite is fused with labradorite, it is absorbed, and upon cooling the melt, augite crystals 

appear. With magnetite and anorthite, hercynite may be formed; 

leucite and acmite give magnetite, leucite, and glass; and so. on. 

Again, leucite and nephelite are incompatible with quartz, which 

converts them into feldspars; and a multitude of such conditions 

help to determine what compounds shall crystallize from any given 

magma. In a magma of defined composition certain compounds 

are capable of existence, 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. Plow far this rule may apply 

to magmas is uncertain, and especially so because of our ignorance as, 

to what the ions actually are. Still we may assume that olivine, " 

Mg2SiO4 , and enstatite, MgSiO3 , 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, SiO3 , SiO4 , AlSiO4 , and AlSi3Os. 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,d namely, ores and oxides first, then the ferromagnesian minerals, then the feldspars, and finally, if an excess of silica is

« Centralbl. Min. Geol. Pal., 1903, pp. 705, 743.

6 Idem, 1904, pp. 295, 340, 364, 1906, p. 132.

c Idem, 1904, pp. 705, 739. See also memoirs by B. K. Schmutz, Neues .Tahrb., 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. Reiter, idem, Beil. Bd. 22, p. 183, 1906; R. Freis, idem, Beil. 

Bd. 23, p. 43, 1907; and V. Poschl, Centralbl. Min. Geol. Pal., 1906, p. 571. Preis 

has much to say about eutectics. These writers were students or assistants of 

Doelter.

d Neues .Tahrb., 1882, pt. 2, p. 1. ' Compare papers by J. .Toly, Proc. Roy. Soc. Dublin, 

vol. 9, p. 298, 1900 ; T. A. Cunningham, idem, p. 383, 1901 ; 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. 253

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 

olivine may be due either to their relative infusibility, to their insolubility in the remainder of the magma, or, as Doelter" supposes, to 

their superior stability at high temperatures. The interpretation of 

the evidence is by no means a simple affair.6

DIFFERENTIATION.

The question whether there is, within the earth, a single, sensibly 

homogeneous magma, is one that concerns geology, but does not 

seem to be directly approachable through chemical evidence. If, 

however, AVC 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

« Sitzungsb. Akad. Wien, vol. 113, p. 495, 1904. Doelter gives many data "on the separa- 

' tlon of minerals during the cooling of melts of known composition. The different species 

were first fused together.

6 The importance of discriminating between the fusibility of a mineral and its solubility 

in a magma is strongly emphasized by A. Lagorio, in Zeitschr. Kryst. Min., vol. 24, p. 285, 

1895. Minerals may dissolve at temperatures far below their melting points, just as salt 

dissolves in water. It is also necessary to distinguish between simple solution and chemical reactivity. In the one process a body dissolves and recrystallizes from solution without change. In the other it dissolves because of reactions with the solvent, and new 

compounds are generated. In either process, however, a solution may become saturated, 

and then its solvent action ceases.
254 THE DATA OF GEOCHEMISTRY.

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. 

Bimsen assumed the existence of fayo 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 

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.

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,0 and more recently W. C. Brogger- 6 and F. Loewinson-Lessing c 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

- ,. J question.

. Although K. W. Bunsen was the first to show that a magma is really 

a solution, little attention was paid to this consideration until 

A. Lagorio,* 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,

"Bull. Phil. Soc. Washington, vol. 12, p. 89, 1892.

6 Die Eruptivgesteine des Kristianiagebietes, pt. 3, pp. 276 et seq., 1898. 

c Compt. Rend. VII Cong. g6ol. internet, p. 308, 1897.

''Min. pet.Mitth., vol. 8, p. 421, 1887. This memoir is rich in references to former 

literature.
THE MOLTEN MAGMA. 255

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 a 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. Backstrorn b 

pointed Out that although the operation of Soret's principle might 

cause changes in the absolute concentration, it could no more aiter 

the relative proportions of the dissolved substances than it could in 

a mixture of gases.

Another process which surely plays a part in the differentiation 

of magmas is the solution of foreign material. The molten lava, as 

it 'rises from the depths to the surface of the earth, is inclosed between walls of rock upon which it exerts a solvent action. This 

action may be very slight or it may be important; and its extent will 

depend on the character of the magma, the character of the rock 

with which it is in contact, the temperature, and the pressure. Not 

one of these factors can be set aside as negligible. 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.0 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

« Am. Jour. Sci., 4th ser., vol. 3, p. 21, 1807.

''.Tour. Geol., vol. 1, p. 773, 1803. See also F. Loevvinson-I.essing, Compt. Rend. VII 

Cong. geol. internal:., p. 390, 1897.

' ' See, for example, H. ,T. Jolinstou-Lavis, The ejected blocks of Monte Somma : Trans. 

Edinburgh Geol. Soc., vol. 6, p. 314, 1892-93. Also a paper in Natural Science, vol. 4, 

p. 134, 1894. 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, pyrophyllitc, leucite, and quartz in magmas, see A. Lagorio 

(Zeitschr. Kryst. Min., vol. 24, p. 285, 1895) ; 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 bemused 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, p. 1021, 1896.
256 - THE DATA OF GEOCHEMISTRY. i

effectiveness is by no means universally admitted. K. A. Daly,a 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 Levy b that differentiation 

is brought about chiefly by a circulation at high temperatures and 

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 f erromagnesian '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,0 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,d 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

a Am. Jour. Sci., 4th ser., vol. 15, p. 269, 1903; vol. 16, p. 107, 1903 ; vol. 20, p. 185, 

1905; and'in the Rosenbusch "Festschrift," 1906, p. 203. See also Bull.' U. S: Geol. 

Survey No. 209, p. 104, 1903, on the rocks of Mount Ascutney. A discussion of Daly's 

views, mainly adverse, at a meeting of the Geological Society of Washington, is reported 

in Science, vol. 25, p. 621, 1907. J. I-I. L. Vogt (Die Silikatschmelzlosungen, pt.' 2, p. 

225, 1904) regards the assimilation theory as quite untenable.

»Bull. Soc. ge"ol., 3d ser., vol. 25, p. 367, 1897.

" The Ancient Volcanoes of Great Britain, vol. 2, p. 477, 1897.

<* Bull. Phil. Soc. Washington, vol. 12, p. 89, 1892. Compare J. E. Spurr, Jour. Geol., 

vol. 8, p. 621, 1900, on the succession of the igneous rocks in the Great Basin of Nevada. 

Spurr gives a good 'historical summary of the subject, beginning with the pioneer work of 

Richthofen.
THE MOLTEN MAGMA. 257

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.

In a later paper than that previously cited G. F. Becker ° 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 betAveen Avails which are cooler than itself, 

and along these surfaces the less fusible or less soluble minerals will 

first crystallize. The process is aided by the circulation of convection 

currents; and that portion of the fused mass which last solidifies, 

the mother liquor, Avill be the portion of maximum fusibility, and, 

therefore, approximate to a eutectic mixture. The center of the dike 

or laccolith Avill thus have one composition and its outer parts 

another. In his memoir upon the HighAvood Mountains L. V. Pirsson l discusses the process in some detail, and shoAvs hoAv convection 

and crystallization may go on together. When great differences in 

specific gravity exist, as in the separation of the heavy titaniferous 

magnetite of the Adirondacks from the lighter rocks of the same 

magmatic mass,0 the crystallizing substances may settle to the bottom, 

and form a distinct layer quite unlike the superincumbent material. 

In the differentiation of the eruptive iron ores of Norway, as 

described by J. H. L. Vogt,rf the- same process may operate, although 

Vogt gave another interpretation to the phenomena. In cases of this 

kind the liquation hypothesis of J. Durocher ° may be partly applicable, and Ave can easily conceive 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 Avorking 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 solu-

"Am. Jour. Sci., 4th ser., vol. 4, p. 257, 1897.

"Bull. U. S. Geol. Survey No. 237, p. 183, 1905. Compare ulso A. Harker, Quart. .Tour. 

Geol. Soc., vol. 50, p. 324, 1894; and T. L. AValker, Am. .Tour. Sci., 4th ser., vol. 6, p. 

410, 1898.

< See, J. F. Kemp, Nineteenth Ann. Kept. U. S. Geol. Survey, pt. 3, p. 417, 1899.

d See summary by J. J. IT. Tea.ll in Geol. Mag., 1892, p. 82.

" Ann. mines, 5th ser., vol. 11, p. 217, 1857.

14399 Bnl 1.330 OS 17
258 THE DATA OF GEOCHEMISTEY.

tions, and that does not often occur. J. Morozewicz,<\ however, in 

his experiments upon artificial magmas, observed several cases in 

which his melts differed in composition from top to bottom, the 

undermost portion being the heaviest. Similar differences of densit}r 

are well known to the glass makers, as shown by variations in refractive capacity between the top and bottom portions of their melts. 

Such a " gravitative adjustment" is presumably most effective in 

slowly cooling magmas, especially when partial crystallization has 

occurred. The minerals first formed must have time to sink. The 

rate of cooling, therefore, is a distinct factor in the differentiation of 

igneous rocks.

To these agencies in the process of differentiation must be added 

that of pressure. This has been taken into account by Martin 

Schweig,& 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 c 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

a Min. pet. Mitth., vol. 18, p~. 233, 1888-89. ,

6 Neues Jahrb., Bell. Bd. 17, p. 516, 1903. Originally published as a doctoral dissertation. The paper contains a good summary, clown to 1903, of the entire subject of differentiation.

"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. 259

phenomena are less complex; but even then we are only able (o 

v follow them partially. Fractional crystallization, liquation, the 

influence of dissolved vapors, and the assimilation of foreign material 

A 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 Ave recede from the eutectic point. The 

' more closely the composition of a magma approaches entectic ratios, 

the less capable of fractionation it becomes.

RADIOACTIVITY.

This chapter Avould be incomplete without some reference to recent 

speculations upon the sources of volcanic heat. That heat, hitherto, 

has been commonly referred either to the molten matter left over

r - after the consolidation of the lithosphere, or to a generation from 

mechanical sources, such as pressure and the friction due to movements

\ within the crust. The discovery of radium, however, which emits 

heat continuously, Iras led to new conceptions which are at least worth 

mentioning.

Maj. C. E. Dutton 0 has suggested that volcanic heat may be dev veloped by radioactivity in limited tracts from 1 to 3 and not over 4 

miles below the surface of the earth. Heat thus developed might so 

accumulate as to fuse the rocks in which it was generated. In time, 

when enough material was melted, the water inclosed in the magma 

thus produced would become explosive, and an eruption would follow. Then a period of quiet would ensue, more heat would be 

released by the subterranean radium, and another explosion would 

occur. Thus 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. Button's views have 

been opposed by G. D. Louderback,6 partly on geological grounds, and 

partly because radiferous minerals, such as uraninite, are not found

- among volcanic products. On the other hand, the lavas of Vesuvius ° 

and Etna d have been shown to be radioactive, and E. J. Strutt 6 has

-"*" found radioactivity in many igneous rocks. The granites are most 

active, the subsilicic rocks least, but on the whole the distribution of 

radium within the earth seems to be fairly uniform, and from its decay the internal heat must be, in part at least, derived. Whether all 

or even a large portion of it is so generated is another question. G.

o Jour. Geol., vol. 14, p. 259, 1906. 

' " Fdera, vol. 14, p. 747, 1906.

c See 0. Scarpa, Atti Accad. Lincei. 5th ser., vol. 16, p. 44, 1907 ; also R. Nasinl and 

M. G. Levi, idem, vol. 15, p. 391, 1906.

 'G.'T. Castorina, Noues Jahrl)., 1907, p. 11 (abstract). 

" Proc. Roy. Soc., vol. 77, ser. A, p. 472, 1906.
260 THE DATA OF GEOCHEMISTRY.'

von dem Borne a has also reported that the granite of the Erzgebirge 

is strongly radioactive. The distinctly radioactive minerals, the ores 

of uranium and thorium, are, it should be remembered, principally 

found in granite and pegmatite. Evidently a new field has been 

opened to investigation, and the discoveries to be made within it are 

likely to have very definite bearing upon geological problems. 6

0 Zeitschr. Deutsch. geol. Gesell., vol. 58, p. 1, 1906.

6 See also memoirs by A. S. Eve, Phil. Mag., 6th ser., vol. 12, p. 189, 1906, and G. A. 

Blanc, idem, vol. 13,.p. 372, 1907. On radioactivity in Australian minerals, see D. Maw-- 

son and T. H. Laby, Chem. News, vol. 92, p. 39, 1905. Other notes on the relations of 

radium to geology have been'published by T. M. Reade, Geol. Mag., 1906, p. 79; J. Joly, 

Nature, vol. 75, pp. 294, 342, 1907, and W. .T. Sollas, idem, p. 319. E. Rutherford, in his 

Radioactive Transformations, p. 213, New York, 1903, has calculated the amount of radioactive matter needed to account for the internal heat of the earth, and has applied his 

figure? to a computation of the age of our planet. This age he estimates as several hundred millions of years. On radium in rocks near Montreal see A. S. Eve and D. Mclntosh, 

Phil. Mag., 6th ser., vol. 14, p. 231, 1907.
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 magmatio differentiation, and in 

which molecular diffusion plays a-n important part, each mineral is 

distinctly marked off in space and occupies a region of its own. It 

may not be pure; it may entangle, during its formation, particles of 

other substances, but its definiteness and integrity are none -the less 

clear.

Although more than a thousand distinct mineral species are known 

to science, only a. relatively small number of them are in any sense 

abundant or to be reckoned as essential constituents of rocks. An 

igneous rock is usually a mixture of silicates, containing, as basic 

metals, potassium, sodium, calcium, magnesium, iron, and aluminum, 

with oftentimes free silica: Other substances are present only in 

quite subordinate proportions. There may be small quantities of 

phosphates, especially apatite, some fluorides, various free oxides, the 

titanium minerals, zircon, sulphides in trivial amount, and sometimes 

free elements, such as graphite or metallic iron; but these constituents of a rock have only minor significance, except in some exceedingly rare instances. The exceptions need not be considered now.

Each mineral species, using the word in its rigorous sense, is a definite chemical entity, capable of formation only under certain distinct 

conditions, and liable to alteration in various ways.- Each one may be 

studied as it exists in nature, with the alterations which it there 

undergoes; or it may be investigated synthetically, with reference to 

its possible modes of origin, or by analytical methods in order to 

determine what transformations it is likely to experience. Both 

methods, the experimental and the observational, furnish legitimate 

lines of attack upon geological problems. A mineral, with its associations, is a record of chemical changes that have taken place, but they 

do not end its history. It is still subject to decay that is, to transformations into other forms of matter, and their study, chemically 

or in the field, constitutes an important part of metamorphic geology. 

Alteration products are highly significant, but their investigation 

demands extreme caution. Errors of diagnosis have been common in

261
262 . 'THE DATA OF GEOCHEMISTRY.

the past, both as to the nature of substances and with regard to their 

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 text-book upon mineralogy would be widely separated. The problems of paragenesis, which are all-important here, 

are quite independent of mineralogical classification. The titanium 

minerals rutile, ilmenite, perofskite, and titanite, for example 

can be properly considered successively, although one is an oxide, 

two are titanates, and the fourth is a titanosilicate. Petrographically 

they belong together; mineralogically they do not. So much" premised, we may go on to study the individual species, as follows, 

beginning with the free elements, carbon and iron. The inclusion of 

diamond in this category may be justified by the fact that it is essentially a mineral of magmatic origin.

DIAMOND AND GRAPHITE.

Diamond. Pure or nearly pure carbon. Isometric. Atomic 

weight, 12; molecular weight, unknown. Specific gravity, 3.5. 

Atomic volume, 3.4. Hardness, 10. Colorless to black, with various 

shades of yellow, green, blue, red, and brown. The black carbonado
ROCK-FORMING MINERALS. 263

has a specific gravity slightly below that of the pure diamond, ranging from 3.15 to 3.29. Fusibility unknown, probably above 3,000°. 

Combustible at high temperatures, between 800° and 850°, according 

to H. Moissan,a although oxidation begins at a point somewhat lower. 

The diamond has been produced artificially in several ways. R. S. 

Marsden,6 in 1880, claimed to have obtained minute crystals from the 

solution of amorphous carbon in molten silver. J. B. Hannay,c 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,d 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. Friedliinder e dissolved graphite in fused olivine and obtained small diamonds, and 

R. von Hasslinger/ by solution of amorphous carbon in an artificial 

magnesium silicate magma, was similarly successful. A little later 

R. von Hasslinger and J. Wolff ff 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'' 

claim to have found diamonds in hardened steel, and A. Ludwig i 

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 LudAvig i. 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,fc who finds that when carbon is raised to a high temperature 

at atmospheric pressure it volatilizes without fusion and on cooling

°Compt. Rend., vol. 135, p. 921, 1902.

6 Proc. Roy. Soc. Ediuburgh, vol. 11, p. 20, 1880-81. K. Chrustchoffi (Zeltschr. anorg. 

Chemie, vol. 4, p. 472, 1893) also obtained diamonds, from solution in silver. Molten 

silver, he says, can dissolve about 6 per cent of carbon.

c Froc. Roy. Soc., vol. 30, pp. 188, 450, 1880.

"Compt. Rend., vol. 116, p. 218, 1893. Also C. Friedel, idem, p. 224. See also Q. 

Majorana, Atti Accad. Lincei, 5th ser., vol. 6, pt. 2, p. 141, 1897.

0 Abstract in Geol. Mag., 1898, p. 226. .

'Monatsh. Chemie, vol. 23, p. 817, 1902.

« Sitzungsb. Akad. Wien, vol. 112, p. 507, 1903.

" Chem. Centralbl., 1896, pt. 2, p. 573. From Stahl u. Eisen, vol. 16, p. 58"..

*Chem. Zeitung, vol. 25, p. 979, 1901.

i Zeitschr. Electrochernie, vol. 8, p. 273, 1902.

fc Compt. Rend., vol. 140, p. 277, 1903. See also Ann. chim. phys.. Sth ser., vol. 5, p. 

174, 1905.
264 THE DATA OF GEOCHEMISTRY.

always yields graphite alone. In Moissan's Avork, however, external 

pressure is not applied. It is generated by internal expansion within 

the iron, Avhen 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. Kousseau/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 6 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 c 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,*1 and Carcote, Chile,6 and the meteoric iron of Canyon Diablo^ The Novo-Urei stone is essentially a mixture of olivine, 67.48 

per cent, with augite 23.8.2 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.? The volcanic character of this matrix or " blue ground " 

was early recognized, and several authorities, notably the late H. 

Carvill Lewis,'1 have ascribed the origin of the diamonds to the solvent action of the molten peridotite magma upon the carbonaceous 

shales through which it has penetrated. In some cases, however,

« Compt. Rend., vol. 117, p. 164, 1893.

6 Nature, vol. 72, p. 397, 1905.

c Proc. Roy. Soc., vol. 76 A, p. 458, 1905.

d M. Erof<5ef and P. Latschinoff, Jour. Russ. Chem. Soc., vol. 20, p. 185, 1888. Abstract 

in Jour. Chem. Soc., vol. 56, p. 224, 1889.

« W. Will and J. Pinnow, Ber. Deutsch. chem. Gesell., vol. 23, p. 345, 1890. 

. f G. A. Koenig and A. E. Foote, Am. Jour. Sci., 3d ser., vol. 42, p. 413, 1891.

" See E. Cohen, 5. Jahresb. Ver. Erdkunde, Metz, p. 129, 1882.

''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. 

See also L. de Launay, Les diamants du Cap, Paris, 1897, and G. F. Williams, The Diamond Mines of South Africa, New York, 1902. There is a copious journal literature on 

the African diamonds. A very recent memoir by R. Beck appears in Zeitschr. Deutsch. 

geol. Gesell., vol. 59, p. 275, 1907. It contains many bibliographic references.
> BOCK-FORMING MINERALS. 265

t^ these shales are absent, and W. Luzi" has shown that Avhen "blue 

J 1 ground" is fused at a temperature of about 1,770° the diamonds 

i which it contains are perceptibly corroded. That is, the magma itself 

; is proved to be a solvent of carbon which may j ust 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 asso- 

'!> ciated more or less closely with rocks of serpentinous that is, peridotitic character. T. G. Bonney,6 however, has sought to prove that' 

I the true matrix of the Cape diamond is eclogite, from which he 

' says the mineral has crystallized as an original constituent, just as 

Xy zircon crystallizes from granite. The very intimate association of 

Ij' these diamonds with garnet lends support to this view. On the 

;; other hand, G. F. Williams 0 states that he crushed and examined 20 

I 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 

j5 igneous origin of the gem, for apophyllite is a highly. hydrous

mineral.

But peridotite is not the only possible matrix for diamond. In

-' Brazil it is associated with hydromica schists and the peculiar form 

of quartzite known as itacolumite; and O. A. Derby (l finds no evi-

*' dence of olivine rocks anywhere in the diamond-bearing region. 

Furthermore, near Bellary, Madras Presidency, India, M. Chaper G 

found the diamond to be apparently derived from a pegmatite con-

' r sisting of rose-colored orthoclase and epidote. Near Inverell, New

-;-H South Wales, T. W. Edgeworth David f found diamonds in a matrix

 of hornblende diabase. In short, though much evidence points to an 

j igneous origin for the diamond, it is not necessary to assume that the 

: same magma has yielded it in all cases.*'

,|i>- -Ber. Deutsch. chem. Gesell., vol. 25, p. 2470, 1892.

11 » Proc. Roy. Soc., vol. 65, p. 223, 1899. Bonney's view is accepted by A. L. Du Toit, 

j ( Eleventh Ann. Rept. Geol. Commission, Cape of Good Hope, p. 135, 1907. G. S. Cor- 

! i storphine (Trans. Geol. Soc. South Africa, vol. 10, p. 65, 1907) shows that the supposed 

I' eclogite, in which he found diamonds, consists really of garnet-pyroxene nodules which

i are inclosed in the kimberllte. These nodules are concretionary in character. 

I' » Trans. Am. Inst. Min. Eng., vol. 35, p. 440, 1905.

f "Am. Jour. Sci., 3d ser., vol. 24, 1882, p. 34; Jour. Geol., vol. 6, p.' 121, 1898. For 

T' the minerals associated with Brazilian diamond see E. Hussak, Min. pet. Mitth., vol. 18, 

;>M p. 334, 1898-99; and also in Zeitschr. prakt. Geol., 1906, p. 318. According to Hussak, 

!;, 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 

7T is by C. Heusser and G. Claraz, Zeitschr. Deutsch. geol. Gesell., vol. 11, p. 448, 1859.

« Compt. Rend., vol. 98, p. 113, 1884. More fully, In Bull. Soc. geol., 3d ser., vol. 14,

p. 330, 1885-86. The description of this pegmatite suggests a resemblance to the unakite

of Virginia and North Carolina. 

J t Rept. Brit. Assoc. Adv. Sci., 1906, p. 562. See also Chem. News, vol. 96, p. 146,

* ^ 1907.

mf' "An excellent monograph on the diamond, by E. Boutan, forms a volume in Fremy's

j|L Encyclopedic chlmique, Paris, 1886. It concludes with a very full bibliography. On

'M diamonds in California, see H. W. Turner, Am. Geologist vol. 23, p. 182, 1899. For a

theoretical discussion on the genesis of the diamond, S"e A. Koenig, Zeitschr. Electrochemie, vol. 12, p. 441, 1906. On the recent discovery of diamonds in Arkansas, see

f G. F. Kunz and H. S. Washington, Am. Jour. Sci., 4th ser., vol. 24, p. 275, 1907.
266 THE DATA OF GEOCHEMISTBY. <£

Graphite. Carbon, more or less impure. Ehombohedral. 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 T00°.a

Graphite is easily produced artificially and is therefore a common 

constituent of furnace slags. Here it is derived from the fuel. It is 7 - 

made on a commercial scale by heating coke in the electric furnace, in 

which process, according to E. G. Acheson,6 a carbide, possibly carborundum, SiC, is first formed. 0. Miilhauser ° has shown that when 

carborundum is strongly heated the silicon is vaporized, leaving ^ 

graphitic carbon behind. These reactions, connected with Moissan's i 

discovery (l 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 sub- ~ 

stances occur in volcanic emanations is so far a matter of pure speculation. So also is- E. Weinschenk's suggestion e that metallic carbonyls, rising from great depths, may yield graphite by their decom- ' 

position. None of these compounds has been identified in nature, 

and it is more than doubtful whether they could exist at magmatic 

temperatures. J. Walther f is inclined to attribute the Ceylon graph- <.- 

ite to derivation from carboniferous vapors rising from the interior 

of the earth, and it is possible that hydrocarbons might yield the ; 

mineral. M. Diersche^ studying the same field, ascribes the formation of the graphite to the infiltration of liquid, hydrocarbons and J. 

their decomposition by heat.

W. Luzi'f has shown that amorphous carbon can be dissolved in X 

a fused potash glass containing a little calcium flnoride and redeposited as graphite. In other words, graphite can form in a silicate 

magma, either in consequence of its contact with carbonaceous matter A. 

or as an original constituent brought up from below. In fact, graph- \ 

ite often, originates as a product of contact metamorphism. L.

« H. Moissan, Compt. Rend., vol. 135, p. 921, 1902. ^- '

» .Tour. Franklin Inst, vol. 147, p. 475, 1899.

c Zeitschr. anorg. Chemie, vol. 5, p. Ill, 1894.

<* Compt. Rend., vol. 140, p. 405, 1903. /

« Comp. Rend. VIII Cong. geol. internal., vol. 1, p. 447, 1900. /,

'Zeitschr. Deutsch. geol. Gesell., vol. 41, p. 359, 1889. For a full account of the Ceylon 

graphite see A. K. Coomara-Swamy, Quart. .Tour. Geol. Soc., vol. 56, p. 609, 1900. This v .'« 

paper contains a valuable bibliography. J

a .Tahrh. K.-k. geol. Reichsanstalt, Wien. vol. 48, p. 274, 1898. ' . t

"Ber. Deutsch. chem.-Gesell., vol. 24, p. 4093, 1891.
ROCK-FORMING: MINERALS. 267

flaczewski* 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. Wemschenk,b 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. 

T. H. Holland,0 however, has described an elaeolite syenite from India 

in which graphite appears to be an original mineral; and Moissan d 

examined a pegmatite of unknown locality and reached a similar con«- 

clusion. 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 grains of native iron are not uncommon in certain eruptive 

rocks, especially in basalts. They were 'first identified by T. Andrews f in the basalt of Antrim, Ireland. More recently they have 

been found by G. H. Cook ff in the trap rocks of New Jersey; by 

G. W. HaAves ll in the dolerite of Dry River, near Mount Washington, 

New Hampshire; by F. Navarro i in the' basalt of Gerona, Spain; 

and by F. F. Hornstein i 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.

" Neues Jabrb.. 1001, vol.. 2, ref., p. 74.

< . Compt. Uend. VIII Cong. g&>l. internal;., vol. 1, p. 447, 1000. 

c Mem. Geol. Survey India, vol. 30, p. 201, 1001. 

"Compt. Rend., vol. 121, p. 538, 1805.

" See K. ,T. V. Steenstrup, Mineralog. Mag., vol. 6, p. 1, 1884; and .1. Ijorenzen, 

idem, p. 14.

' Kept. Brit. Assoc., 1852, pt. 2, p. 34.

" Ann. Kept. Geol. Survey New Jersey, 1874, p. 56.

'' Am. .Tour. Sci., 3d ser., vol. 13, p. 33, 1877.

« Geol. Centralbl., vol. 7, p. 184, 1905.

i Centralbl. Min. Geol. Pal., 1007, p. 270.
268 THE DATA. OF GEOCHEMISTRY.

There are also a number of other European occurrences. E. Hussak " 

found particles of native iron in an auriferous gravel in Brazil; and 

A. Daubree and S. Meunier 6 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 T.59.

The most remarkable occurrence of native iron, however, is that discovered by A. E. Nordenskioldlc in 1870, at Ovifak, Disco Island, 

Greenland. 'Here large masses 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.^ 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 ° graphite, amorphous carbon, and grains of 

corundum were found.

This Ovifak iron is somewhat variable in composition, as the numerous analyses of it show.^ The following analyses by J. Lawrence 

Smith are enough to indicate its general character:

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.

Fe2 03 . ............'.............................................

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

Ni.......... ....:.......... ....................................

Co..............................................................

Cu....... ......................................................

S.......... ....................................................

p....................:.................................-........

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

Cl........ ..................................................... Mgo.................... ;......................................

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

HS 0............. ..............................................

A.

76.21

16.56

1.08

.48

.08

1.12

.14

1.36

4.50

101.53

B.

93.16

2.01

.80

.12

.41

.32

2.34

09

99.18

C.

90.17

C.50

.79

.13

1.54

99.13

D.

88.13

2.13

1.07

.48

.36

.25

2133

.08

4.20

99.03

" Bol. Comm. geog. e geol. Sao Paulo, No. 7, p. 14, 1890. ' '

"Compt. Rend., vol. 113, p. 172, 1891.

c Geol. Mag., 1872, pp. 460, 516.

d There is abundant literature on this subject. See especially K. J. V. Steeustrup, 

Mineralog. Mag., vol. 6, p. 1884; J. Lorenzen, idem, p. 14; .T. Lawrence Smith, Ann. 

chim. phys., 5th ser., vol. 16, p.- 452, 1879; and A. Daubre"e, fitudes synthe"tiques de 

geologic expe"rimentale, p. 555, 1879.

» Compt. Rend., vol. 116, p. 1269, 1898.

f See the memoirs, already cited, by Nordenskiijld, Lorenzen, and Smith, Also E. S. 

Dana, System of Mineralogy, 6th ed., p. 28.
KOCK-FOKMING MINEBALS. 269

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 beloAv? The latter supposition is admissible, 

for Daubree,'1 by fusing a Iherzolite with carbon, obtained pellets of 

metallic iron, containing nickel and almost identical in composition 

with the specimens from Greenland. Furthermore, as Daubree 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 imcombined metals.6 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 Avould 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 c obtained 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/' from neighboring serpentines or peridotites. The josephinite of W. H. Melville 0 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. Itsspecific gravity is 6.204. In the sands of the Elvo, near Biella, Piedmont, A. Sella f 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 o 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 peridotites. Still 

more recently a similar nickel iron from the south fork of Smith

" fitudes synthe'tiques de gfiologie exptfrimentale, pp. 517, 574, 1879.

."See also E. B. de Chancourtois, Bull. Soc. gSol., vol. 29, p. 210, 1872. C. Winkler 

(Ber. Math. phys. Classe,'K. saclis. Gesell. Wiss., February 5, 1900) suggests that iron 

and nickel may have heen brought up from below as carbonyls, N1(CO) 4 , Fe(CO)s, and 

Fe2 (CO)? compounds which decompose easily, depositing their metals in the free state. 

Compare Weinschenk's suggestion as to graphite, ante, p. 266.

c Trails. New Zealand Inst, vol. 18, p. 401, 1885.

'' Quart. Jour. Geol. Soc., vol. 46, p. 619, 1890.

"Bull. TJ. S. Geol. Survey No. 113, p. 54. 1893.

'Compt. Rend., vol. 112, p. 171, 1891. 

« Am, Jour. Sci., 4th ser., vol. 19, p. 319, 1905,
270 THE DATA OF GEOCHEMISTRY.

River, Del Norte County, California, has been described by G. S. 

Jamieson,ft who has also reexamined the'mineral from Oregon. The 

analyses are .as follows:

Analyses of -nickel iron.

A. Awaruite, Skey. B. Josephinlte, Melville. C. Josepbinite, .Tamieson. D. Del Norte

County, Jamieson. E. Souesite, I-Ioffmann. F. Piedmont. Analyzed for Sella by

Mattirolo. . .

Ni. ............:..........................

Co........................................

Fe................................ '........

Y*i$t.. ...................................

S.. .......................................

Cu,.... ...................................

As........................................

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

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

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

H2 0 at 100° ...............................

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

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

A. '

07.63

.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

18.97

.05

.56

.04

19

' 9.97

.44

99.75

E.

75.50

22.02

1.20

1.16

99.88

¥.

75.2

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 compared. That found in an Indian mound in Oktibbeha County, Mississippi, contained 59.69 per cent Ni and 37.97 per cent Fe; and that 

 from Santa Catarina, Brazil, carried 63.69 Fe with 33.97 Ni. These 

masses, however, are only presumably, not certainly, meteoric.

Occasionally native iron is found of secondary origin produced by 

the obvious reduction of iron compounds. On ^orth Saskatchewan 

River, 70 miles from Edmonston, beds of lignite have burned, reducing the neighboring clay ironstone to metallic iron. According to 

J. B. Tyrrell,6 masses of iron can be picked up in this locality.which 

weigh from 15 to 20 pounds. G. C. Hoffmann c 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.^ The exact origin of these Canadian irons is 

not clear. Finally, E. T. Alien c 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

0 Am. Jour. Sci., 4th ser., vol. 19, p. 413. .Tamieson urges that the original name 

awaruite should be used for all these nickel irons. 

"Am. Jour. Sci., 3d ser., vol. 33, p. 73, 1887. 

" Trans. Roy. Soc. Canada, vol. 8, pt. 3. p. 39. 1.S90. 

 ' Ann. Kept. Geol. Survey Canada, vol-. 6. p. 28 It, 1895. 

" Am. Jour. Sci., 4th ser., vol. 4, p. 99, 1897.
ROCK-FORMING MINERALS. 271

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, I-Ioffimann. Specific gravity, 6.8612.

B. From Cameron Township, Ontario. Analysis by Johnston for Hoffimann. 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. .............................................

T:. ......... .... ... .. ... .. ....

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

SiO2 . ................................................

Organic matter. ....................................

A.

88.00

.10

.21

.51

.09

10

.90

(?)

9 7ft

99.75

B.

on di

.75

none

7.26

98.46

C.

OQ 1f»

.207

.065

.37

99. 802

D.

99. 39

.13

.31

99.83

E.

97.10

.176

1.65

9&92G

Not only iron but other native metals may occur as primary constituents of igneous rocks. Platinum, with its companions, osmium, 

indium, rhodium, ruthenium, and palladium, are associated with 

chromite and olivine in peridotites." W. Moricke 7' has found primary gold in a pitchstone from Guanaco, Chile, and G. P. Merrill c 

has described a granite from Sonora in which it also appears. Still 

other examples are cited by K. Beck.d 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.

Pyiite. Isometric. Composition, FeSo. Molecular weight, 120. 

Specific gravity, 4.95 to 5.10. Molecular volume, 24. Color, brassyellow ; luster,' metallic. Hardness, 6 to G.5.

Pyrrhotite. Hexagonal Composition uncertain, varying from 

Fe7 S8 to Fe^Si,. 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 that need not be considered here.6 ' " .

'" See .1. F. .Kemp, Bull. U. S. Geol. Survey No. 193, 1902, for a complete summary of 

our knowledge concerning native platinum, with many bibliographic references.

"Min. pet. Mitth., vol. 12, p. 195, 1891.

c Am. Jour. Sci., 4th ser., vol. 1, p. 309, 1896.

d Lehre von den Erzlagerstiitten, 2d ed., 1903. See also W. I-I. Weed, Eng. and Min. 

Jour., vol. 77, p. 440, 1904 : and R. W. Brock, idem, p. .511.

0 See S. Meunier, Ann. chim. phys., 4th ser.. vol. 17, p. 36, 1869; and G. Linck, Ber. 

Deutsch. chem. Gesell., vol. 32, p. 895, 1899.
272 THE DATA OF GEOCHEMISTEY.

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/1 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 b produced crystals which' appeared to' be identical 

with troilite. Troilite was also formed by R. Lorenz,0 who heated 

iron to redness in a stream of H,S. C. Doelter,fZ 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.

Metallic sulphides, fairly crystallized, can also be-formed in the 

wet way, when appropriate mixtures are heated together in sealed 

tubes. H. de Senarmont c 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 f also obtained pyrite by heating powdered basalt with water 

and sulphurous acid to 200°. Doelter g prepared pyrite by heating 

hematite,, magnetite, or siderite with hydrogen sulphide and water 

for seventy-tAvo hours to 80° or 90°. When the same investigator 7| 

heated ferrous chloride with sodium carbonate, water, and hydrogen 

sulphide for sixteen days to 200° he obtained pyrrhotite, provided 

that air was excluded from his tubes. In presence of air pyrite was 

formed.

"Compt. Rend., vol. 32, p. 823, 1851.

"Idem, vol. 66, p. 1257, 1868.

"Ber. Deutsch. chem. Gesell., vol. 24, p. 1504, 1891.

rf Zeitschr. Ki-yst. Min., vol. 11, p. 30, 1886.

c Compt. Rend., vol. 32, p. 409, 1851.

f Ann. Chem. Phara., vol. 129, p. 350, 1S64.

o Zeitschr. Kryst. Min., vol. 11, p. 30, 1886.

h Min. pet Mitth., vol. 7, p. 535, 1885-86.
p KOCK-FOKMING MINERALS. 273

 All these processes find some equivalent in nature. Dry gases, wet

gases, and alkaline solutions charged with hydrogen sulphide are

I capable of producing the minerals which are now under considera-

 { tion, with other rarer species of the same class. The magmas contain the reagents, and the reactions, or reactions like those just de-

^ scribed, naturally follow. In most cases the sulphides appear as 

secondary minerals, but they are sometimes primary. J. H. L. Vogt ° 

has shown that sulphides are actually soluble in silicate magmas, 

especially at the higher temperatures, and that they are among the

J- 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 mode of formation is ^ *

unknown. The two species probably differ in molecular arrange- 

. ment, but the evidence upon this point is far from conclusive. Vari- 

~ ous structural formulae have been proposed for them, but none has 

been definitely established.1

* Pyrrhotite and marcasite both alter into pyrite, and all three 

species alter into limonite, goethite, hematite, and sulphates of iron. 

Perfect pseudomorphs of limonite after pyrite are common.0

Several other sulphides occasionally appear as primary minerals 

in igneous rocks. Molybdenite, MoS2 , is common in granites, and 

J. F. Kemp,d 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, FeAs,, 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.0'

" Some of these occurrences and many occurrences of pyrite also are

> ~ doubtless secondary.

FiLUORIDES. *>

Fluonte. -Isometric. Composition, CaF2 . Molecular weight, 78.1. 

i Specific gravity, 3.18. Molecular volume, 24.5. Hardness, 4. ColorV less, yellow, red, blue, green, purple, violet, etc.

."Die Silikatschmelzlosungen, pt. 1, p. 96, 1903. See also Zeitschr. prakt. Geol., 1898, 

V p. 45 ; and Trans. Am. Inst. Min. Bng., 1901, p. 131. For sulphides in slags, see J. H. L. 

Vogt, Mlneralbildung in Schmelzmassen, Christiania, 1892. See also J. E. Spurr, Trans. 

'Am. Inst. Min. Eng., vol. 3C>, p. 306, 1903, on Alaskan pyrrhotite.

6 See B. Weinschenk, Zeitschr. Kryst. Min., vol. 17, p. 501, 1890; A. P. Brown, Proc. 

Am. Phil. Soc., vol. 33, p. 225, 1894 ; 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.

c For a discussion in extenso of the decomposition of pyrite, see A. A. Julien, Ann. 

s New York Acad. Sci., vol. 3, p. 365, 1886; vol. 4, p. 125, 1887.

A Trans. Am. Inst. Min. Eng., vol. 31, p. 182, 1901. 

! " See Zeitschr. Kryst. Min., vol. 16, pt. 2, pp. 5-11, 1890. For very complete analyses

- of Norwegian pyrite, see E. Boettker, Rev. ge"n. chim. pure et app., vol. 9, p. 323.

14399 Bull. 330 08 18 '
274 THE DATA OF GEOCHEMISTKY.

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 0 reports it, bpth 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 

action of fluoriferous gases upon other minerals, on volcanic lavas.6 

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. 0

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/ it is a concretionary secretion in eruptive 

granite. Cr}rolite is also found sparingly at Miask in the Urals and 

in the granites of Pikes Peak, Colorado.6 It is a double fluoride of 

aluminum and sodium, Na3AlF0 . 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.

CORTHSTDTJM.

Rhombohedral. Composition, aluminum oxide, A12 O3 . Specific 

gravity, 3.95 to 4.10; of the purest material, 4.0. Molecular weight/

102; molecular volume, 25.5, Colorless Avhen 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.0 Hardness, 9, thus ranking among natural minerals next to 

diamond.

" Zeitschr. Ki-yst. Min., vol. 16, pt. 2, p. 56, 1890.

''Idem, vol. 7, p. 630, .1883. Abstract of memoir by A. Scacchi. For a study of the 

gases occluded by fluorite, see H. W. Morse, Proc. Am. Acad., vol. 41, p. 587, 1906. According to H. Becquerel and H. Moissan (Bull. Soc. chirn., 3d ser., vol. 5, p. 154, 1891), 

free fluorine is sometimes present. W. .1. Humphreys (Astrophys. Jour., vol. 20, p. 266, 

1904) found spectroscopic traces of yttrium and ytterbium in many fluor spars. G. 

Urbain (Compt. Rend., vol. 143, p. 826, 1906) also found terbium, gadolinium, dysprosium, 

and samarium.

c See. the works cited elsewhere in this chapter, by Brauns, Bourgeois, and Fouque" and 

Levy.

d Cited by F. Zirkel, Lehrbuch der Petrographie, vol. 3, p. 444. The original memoir 

by .Tohnstrup is not within my reach.

c See the works cited elsewhere in this chapter, by Brauns, Bourgeois, and Fouque and

f The ordinary rounded-off atomic weights may he used for computations of molecular 

weights and volumes.

o Compt. Rend., vol. 115, p. 1034, 1892. 1,880° according to W. Hempel.
ROCK-FORMING MINERALS. 275

Crystallized alumina, artificial corundum, has been produced by 

various methods. These are well summarized in the Avorks of Bourgeois and Fouque and Levy, and in the memoir by J. Morozewicz." 

They may be briefly grouped as follows: First, by direct fusion of 

amorphous alumina. Second, by the crystallization of alumina from 

solution in various molten fluxes, such as potassium bichromate, 

sodium molybdate, borax, lead oxide, etc. Most of these processes 

find no equivalent in nature. Third, by the decomposition of aluminum chloride or fluoride by water at high temperatures methods 

which may shed some light upon the formation of corundum as a 

contact mineral, or as a constituent of metamorphic rocks. In some 

of these reactions boric acid plays a part. Fourth, by the decomposition of other minerals, such as muscovite. Finally, by crystallization

of artificial magmas.

It is not necessary, for our purposes to examine these processes in 

detail. It is enough to select from among them those which seem to 

be the most significant. P. Hautefeuille and A. Perrey,& 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. Brunc 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 A obtained corundum in the Avet Avay by 

heating alumina for ten hours to 30*0° in a platinum tube with Avater 

containing a trace of ammonium fluoride; but at 250° no crystallization took place. By similar reactions hematite, quartz, tridymite, 

and ilmenite AA7 ere 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 corundum6 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, hoAvever, is shoAvn by the experiments of G. Friedel/ 

When amorphous alumina is heated to 450-500° AAdth a solution of

" Fouque" and Le"v.y, Synthese des mine"raux et des roches, Paris, 1882. L. Bourgeois, 

Reproduction artificielle des mine'raux, in Fremy's Encyclopedic chimique, vol. 2, 1st appendix. Morozewicz;, Min. pet. Mitth., vol. 18, p. 23, 1898.

"Bull. Soc. min., vol. 13, p. 147, 1890.

c Arch. sci. phys. nat., 3d ser., vol. 25, p. 239, 1891.

 ' Neues .Tahrb., 1889, pt 2, p. 62.

« Ann. chim. phys., 4th ser., vol. 4, p. 153, 1865.

f Bull. Soc. min., vol. 14, p. 8, 1891.
276 THE DATA OF GEOCHEMISTRY. <4

soda, corundum and diaspore, HA1O,, are both produced. At 530- l 

535° corundum alone formed, and at 400° only diaspore. If the 

alumina contained a little silica, crystals of quartz appeared. By a 

similar reaction between ferric hydroxide and soda solution, Friedel ( 

obtained crystals of hematite.

From a geological standpoint the most important experiments f 

upon the genesis of corundum are those of Morozewicz,ft who studied 

the conditions of its deposition from a cooling magma. He worked 

with artificial magmas upon a rather large scale, using the furnaces 

of a glass factory in preparing his melts; and he found that whenever the alumina, in comparison with the other bases, exceeded a cer- 4^ 

tain ratio, the excess, upon cooling the fused mass, crystallized out 

completely either as corundum, as spinel, as sillimanite, or as iolite,6 

The qualifying conditions are as follows: }

An alumosilicate magma in which the molecular ratio of the 

bases CaO, K.,0, Na,O is to A12 03 as 1:1 is said to be saturated with 

respect to alumina. If more alumina is present the magma is super- ^ 

saturated, 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 R,O.mAl,0: ,.nSi(X the following rules are found to " l 

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 ^<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 0S :: 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., T 

whose nature will depend upon the bases which happen to be asso- ^ 

ciated with it, and also upon the proportion of silica.

Previous to the appearance of Morozewicz's memoir it was com- < 

monly 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 "j 

as a product of contact action, although rarely.0 When corundum ^

n Min. pet. Mitth., vol. 18, pp. 22-83, 1898. . Also Zeitschr. Kryst. Min., vol. 24, 

p. 281, 1895.

6 Cordierite. The name iolite has priority and is given preference by Dana.

c K. Busz (Geol. Mag., 1896, p. 492) found corundum in contacts between granite and 

clay slate on Dartmoor in Devonshire. A. K. Coom.lra-Swamy (Quart. Jour. Geol. Soc., 

vol. 57, p. 185, 1901) observed it at contacts between granite and micaceous quartzite W 

n'ear Morlaix, France. The corundum was there associated with sillimanite, andalusite, ' 

spinel, etc. /
ROCK-FORMING MINERALS. 277

was found in igneous rocks it AV as 1 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

o

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,0 is found in alumosilicate rocks only when the latter contain over 30 per cent of alumina, 

and such rocks are rare. Lagorio cites analyses of several examples, 

and Morozewicz 6 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 ° 

'from Canada; and corundum-bearing nepheline syenites, according 

to A. P. Coleman,(Z are also found in the saine region. In the Coimbatore district, Madras Presidency, India,. T. H. Holland G ^found 

large crystals of corundum in an albite-orthoclase rock near its contact with elaeolite syenite. They Avere 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. Lawsonf 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 local! -

0 Zeitschr. Kryst. Min., vol. 24, -p. 285, 1895. This memoir contains abundant .literature references upon the occurrence of corundum in igneous rocks.

* Min. pet. Mitth., vol. 18, pp. 212, 219, 1898. . For present purposes the minor accessory minerals in these rocks may be ignored. 

« Am. Geologist, vol. 24, p. 276, 1899.

* .Tour. Geol., vol. 7, p. 437, 1899.

«Mem. Geol. Survey, India, vol. 30, pp. 201, 205, 1901. For Indian corundum in 

general, see Holland, Manual of Geology of India, Economic geology, pt. 1; F. R. Mallet, 

Rec. Geol. Survey India, vol. 5, p. 20, 1872 ; vol. 6, p. 43, 1873 ; and C. S. Middlemiss, 

i'dem, vol. 29, p. 39, 1896. Mallet describes beds of corundum in gneiss. A remarkable 

corundum rock from India is described by .1. W. Judd in Mineralog. Mag., vol. 11, p. 56, 

1895. For Burmese occurrences, see C. B. Brown and .Tudd, Proc. Roy. Soc., vol. 57, 

p. 387, 1895.

f Bull. Dept. Geology, Univ. California, vol. 3, p. 219, 1903.
278 THE DATA OF GEOCHEMISTRY. . K

ties, was advocated by T. M. Chatard,a but J. H. Pratt b 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 c as segregations in norite.**

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 e and L. V. "^ 

Pirsson/ 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? - J 

This is a question which- demands investigation, but it may be noted .., 

here that Vernadsky/ 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 h 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 j 

of combined water. Even at 100° in an open vessel, some hydration -jL 

occurred. A similar prolonged treatment of corundum with a solu-

" Bull. TJ. S. Geol. Survey No. 42, p. 45, 1887. Chatard gives abundant references to 

literature. See also F. P. King's report upon Georgia corundum (Bull. No. 2, Geol. Survey Georgia, 1894), which contains a bibliography of American publications upon the 

subject. A similar publication by J. V. Lewis, on North Carolina corundum, forms Bull. ft. t 

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.

6 Am. Jour. Sci., 4th ser., .vol. 6, p. 49, 1898 ; vol. 8, p. 227, 1899. In Min. Mag., vol. J 

12, p. 139, 1899, J. W. Judd and W. E. Hidden have a paper upon North Carolina ruby; 

also in Am. .Tour. Sci., 4th ser., vol. 8, p. 370, 1899.

" Am. Jour. Sci., 3d ser., vol. 33, p. 194, 1887.

d For an account of the emery mine at Chester, Massachusetts, see B. K. Emerson, 

Mon. TJ. S. Geol. Survey, vol. 29, p. 117, 1898. In Bull. U. S.- Geol. Survey No. 269, 

190G, 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, p. 99, 1905.

< Twentieth Ann. Kept. U. S. Geol. Survey, pt. 3, p. 454, 1900.

' Idem, p. 552 ; Am. Jour. Sci., 4th ser., vol. 4, p. 421, 1-897. See also G. F. Kunz, 

Am. .lour. Sci., -4th ser, vol. 4, p. 417, 1897.

i Cited by Morozewicz, Min. pet. Mitth., vol. 18, p. 25, .1898.

* Mineralchemische Studien, p. 104, Dorpat, 1891.
 ROCK-FORMING MINERALS. 279

tion of the silicate K2Si2O5 converted it into a substance having the 

composition of orthoclase, while sodium silicate produced a compound resembling analcite. In nature reactions of this kind are 

conceivably possible, but they must be very slow; in the laboratory 

the acceleration due to temperature and pressure accounts for much 

of the change. However, alterations of corundum are common, and 

Thugutt's experiments give us some notion of the way in which they 

were probably effected. By water alone corundum may be transformed into diaspore, HA102 , which is one of its frequent associates. 

By further or coincident action of salts dissolved in percolating 

waters the alteration o^ dorundum can be modified, and a considerable number of other minerals may be produced.'1 Among them 

gibbsite, spinel, sillimanite, kyanite, andalusite, pyrophyllite, muscovite, paragonite, chloritoid, margarite, zoisite, feldspars, tourmaline, 

and various vermiculites and chlorites have been recorded.'' Some of 

these reported alteration products are doubtless secondary and not 

due to the direct transformation of corundum, but on this subject 

there is much uncertainty. The envelopment of one mineral by 

another does not necessarily establish the derivation of the second 

from the first. The field observations and the study of natural specimens need to be reenforced by experiments in the laboratory before 

accurate conclusions concerning the alterations can be drawn.

THE SPINELS.

Spinel. Isometric. Composition, MgAl2 04 . 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, ZnAL,04 , magnetite, 

Fe"Fe'" 2O4 , magnesioferrite, MgFe2O4 , franklinite, and chromite, 

form a natural isometric group, in which there are many intermediate 

mixtures. In the general formula R/'R'",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 O Mg 0 Al=0, but this should not 

be taken as a finality. It is not the only expression possible, nor has 

its validity been proved.

0 For a discussion of the reactions which are supposed to produce the alterations of 

corundum, see C. R. Van lllse, Mon. TJ. S. Geo). Survey, vol. 47, pp. 223-225, 1004.

"F, A. Genth, Proc. Am. Phil. Soc.. vol. 13,-p. 3fil, 1873; vol. 20, p. 381, 1882; Am. 

.Tour. Sci., 3d ser., vol. 30, p. 47, 1800. These papers are full of details regarding alteration products of corundum.
280 THE DATA OF GEOCHEMISTRY.

The following analyses of spinels show the wide variations in their 

composition:

Analyses of spinels.

A. Rose spinel, Ceylon. Analysis by I-I. 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, p. 40, 1866.

D. From pyroxenite, Montana. Analysis by L. G. Eakins, Bull. U. S. Geol. Survey No. 

220, p. 20, 1903.

E. Pleonaste from near Peekskill, New York. Analysis by C. A. Wolle, Am. .Tour. Sci., 

2d ser., vol. 48, p. 350, 1869.

F. ITercynite from the Bohtnerwald. Analysis by B. Quadrat, Liebig's Annalen, vol. 55, 

p. 357, 1845.

A12 03 .....................................

CrtOt.... .................................

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

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

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

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

A.

69.01

 1.10

.71

20.21

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.

r.n ?Q

5.26

21.74

12.84

100.63

F.

61.17

35.67

2.92

99.76

Members of the spinel group have been made artificially by 

methods which generally recall those mentioned under corundum. 

For example, S. Meunier a fused a mixture of alumina, magnesia, 

cryolite, and aluminum chloride, and obtained spinel crystals! In 

another investigation & 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. The details of Morozewicz's experiments need^not 

be repeated here. 0 An interesting emphasis is given to them by the 

observations of G. Linck,d who found, in a German gabbro, spinel 

associated with sillimanite and corundum.6

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/ spinel is among the compounds produced by the 

fusion of biotite, an observation which has been confirmed by C. 

Doelter.*7 F. W. Clarke and E. A. Schneider /l found it to be formed

" Compt. Rend., vol. 104, p. 1111, 1887. 

6 Idem, vol. 90, p. 701, 1880.

c See also J. I-I. L. Vogt, Mineralbildung in Schmelzmassen, pp. 189-203. 

" Sitzungsb. Akad. Berlin, 1893, p. 47.

e See also W. Salomon, Zeitschr. Deutsch. geol. Gesell., vol. 42, p. f»25, 1890, for spinel 

in cordierite contact rocks in Italy.

f Cited by J. Morozewicz, Min. pet. Mitth., vol. 18, p. 59, 1898.

" Neues Jahrb., 1897, pt. 1, p. 1.

" Bull. U. S. Geol. Survey No. 113, p. 30, 1893.
ROCK-FORMING MINERALS. 281

when clinochlore and xanthophyllite were strongly ignited, and 

Doelter a also obtained it by fusing the first-named species. Tourmaline, pyrope, and spessartite also yield spinel among the products 

of their fusion.6

According to Fouque and Levy c spinel and melanite are formed 

when nephelite and augite are fused together, and Doelter and Hussak d obtained spinel from a mixture of fayalite and sarcolite. M. 

Vucnik ° 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-elaeolite mixtures were made by B. Vukits/

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.0 A number of remarkable spinel rocks from Elba have been described by P. Alpisi.'1 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, FeCr2 04 , 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: * »/ \i A

Analyses of chromite.

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, p. 242, 1902.

B. From Corundum Hill, North Carolina. Analysis by C. Baskerville, for J. H. Pratt, 

Am. .Tour. Sci., 4th ser., vol. 7, p. 281, 1899.

C. From Webster, North Carolina. Analysis by H. W. Foote, for Pratt, loc. cit.

D. From Port an Port Bay, Newfoundland. Analysis by E. Waller, for G. W. Mayuard, 

Trans. Am. Tnst. Min. Eng., vol. 27, p. 288, 1897.

°Neues Jahrb., 1897, pt. 1, p. 1.

6 Doelter, loc. cit., for tourmaline. C. Doeiter and E. Hussak, Neues .Tahrb., 1884, pt. 

l,^p. 157, for garnets.

c Synthese des mine'raux et des roches, p. 64.

d Neues Tahrb., 1884, pt. 1, p. 157.

" Centralbl. Min. Geol. Pal., 1904, p. 297. Criticised by .T. Morozewicz in the same 

journal, 1905, p. 148.

t Idem, 1904, pp. 710, 743.

"G. H. Williams, Am. .Tour. Sci., 3d ser., vol. 33, p. 194, 1887. See also .T. H. Pratt, 

Bull. U. S. Geol. Survey No. 269, p. 34, 1906.

ft Proc. verb. Soc. tosc. sci. nat., vol. 15, p. 60.

* 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,
THE DATA OF GEOCHEMISTRY.

E. From Tampadal, lower Silesia. Analysis by Laszczynski, for H. Traube, Zeitschr. 

Deutsch. geol. Gesell., vol. 46, p. 50, 1894.

Cr203 - ..............................................

A12O3 . ..............................................

T^poOo

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

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

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

SiO2 . ................................................

A.

55. 90

13.83

14.64

15.01

.60

99.98

B.

57.80

7.82

25.68

.69

5.22

2.80

100. 01

C.

39.95

29.28

13.90

17.31

100. 44

D.a

49.23

7.50

17.21

18.66

6.51

99.11

E.

41.23

24.58

2.28

16.99

.58

14.77

100.43

"Also contains traces of lime, copper, and vanadium.

The earlier syntheses of chromite seem to have little or no geological bearing. S. Meunier,0 however, who prepared chromite by oxidizing an alloy of iron and chromium, attributes its origin to a 

similar reaction occurring in nature. He supposes that such an alloy, 

like platinum and nickel iron, can be brought up from the interior of 

the earth to be oxidized by vapors when it nears the surface. Unfortunately no such alloy has yet been found in the rocks, and in meteorites chromite itself is a common mineral.

Chromite is essentially a constituent of peridotites and of the serpentines derived from them. It is one of the earliest species formed 

during the solidification of the magma, and its larger deposits, when 

it occurs in ore bodies, are now generally ascribed to magmatic differentiation through the action of gravity. J. H. L. Vogt & thus interprets the chromite deposits of Norway, and J. H. Pratt c has elaborated 

the same conception with respect to the chromic iron ores of North 

Carolina. The origin of corundum and of chromite in dunite Pratt 

explains in the same way. When a peridotite alters to serpentine, 

the refractory chromite remains unchanged.

Magnetite. Isometric. Composition, Fe3O4 , but with variable impurities and replacements. Molecular weight, 231.T. 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 ^he spinels being frequent admixtures in magnetite. The titaniferous magnetites form a well-known 

subclass of ores. In a magnetite from the Tyrolese Alps T. Petersen^ 

found 1.76 per cent of nickel oxide, and the magnetites of eastern 

Ontario may contain half as much.6

" Compt. Rend., vol. 110, p. 424, 1890.

» Zeitschr. prakt. Geol., 1894, p. 384.

"Trims. Am. Inst. Min. Eng., vol. 29, p. 17, 1899. For a general review of chromite 

deposits, see Stelzner-Bergeat, Die Erzlngerstiitten, p. 33, 1904. The magmatic view 

is adopted in this work, and also in Beck's treatise upon ore bodies.

* Neues .Tahrb., 1867, p. 836. . '

« W. G. Miller, Rept. British Assoc., 1897, p. 000.
HOCK-FORMING MINERALS. 283

. . Magnetite is. often observed as a furnace product, and it forms the

" iron scale " of the blacksmith. W. Miiller " 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 6 prepared it, well crystallized, by fusing together an iron silicate and lime. 

According to H. Sainte-Claire Deville," ferrous oxide, heated in a 

stream of hydrochloric acid, forms magnetite, while a mixture of 

magnesia and ferric oxide, similarly treated, yields magnesioferrite, 

Mg.Fe2 04 . T. Sidot a obtained magnetite by the calcination of ferric 

oxide alone.

In artificial magmas magnetite is easily formed, especially when 

the proportion of silica is low. Any excess of iron over that needed 

to combine with silica is likely to be deposited in the form of magnetite, although the conditions of its appearance are not so simple 

as in the separation of alumina as corundum.6 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/ 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, a and glaucophane 

gives similarly a mixture in which magnetite appears. By melting 

together biotite and microcline, Fouque and Levy h obtained magnetite, leucite, and olivine. J. Lenarcic * 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. Vucnik j and B. Vukits,fc 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.

« Zeitschr. Deutsch. geol. Gesell., vol. 45, p. 63, 1893. 

" Compt. Rend., vol. 33, p. 528, 1851. 

« Idem, vol. 53, p. 199, 1861. ,

 ' Idem, vol. 69, p. 201, 1869.

e See .1. Morozewicz, Min. pet. Mittlr., vol. IS, p. 84, 1898, and J. H. L. Vogt, Mlnernlbildung in Schmelzmassen, pp. 203-212. 

f Neues .Tahrb., 1886, pt. 1, p. 128. 

o Doelter, Neues .Tahrb., 1897, pt. 1, p. 1. See also M. VnCnik, cited below.

* Synthese des mlneraux et des roches, p. 77. \ 

^Cmtvzm. Min. Geol/Pal., 1903, pp. 705, 743. 

i Idem,-1904, pp. 300, 342, 344, 345, 366, 369. 

k Idem, 1904, pp. 705, 715, 743, 748.
284 THE DATA OF GEOCHEMISTRY. ^

Magnetite occurs as an accessory mineral in rocks of all classes, ' 

and it sometimes rises to the rank of a principal constituent, or even ^ 

forms rock masses by itself. It is obviously most abundant in rocks , 

rich in ferromagnesian minerals, such as norites, diabases, gabbros, 

or peridotites; but it is also associated with nepheline rocks and " 

anorthites. In many cases it forms large ore bodies that are re- _ 

garded as products of magmatic differentiation; and these deposits, 

as a rule, are highly titaniferous.* Some ores shade from magnetite into ilmenite, with over 40 per cent of titanic oxide. They frequently contain spinel, and sometimes, also, corundum.

In the great iron deposits of the Lake Superior region, and the > 

adjacent parts of Michigan, Wisconsin, and Minnesota, magnetite is 

found in slates and cherts, often associated with griinerite and actinolite. 6 Here the mineral is not of direct igneous origin. In the Mesabi 

district, according to C. K. Leith,c 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 J 

Hise,1* from marcasite and pyrite, and from the oxidation of siderite 

in situ. 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, Fe2O3 . Molecular weight, 159.8. 

Specific gravity, 5.2. Molecular volume, 30.7. Color, red to steel- ^ 

gray and black. Hardness, 5.5 to 6.5. Hematite has been prepared 

artificially by several methods. In the classical experiment of GayLussac,6 the vapor of ferric chloride was decomposed by steam at a 

high temperature, and crystals of hematite were formed. A. Dan- 7-. 

bree f obtained it by passing ferric chloride vapor over lime; and H. 

Sainte-Claire Deville^ prepared the specular variety by the slow

0 See J. H. L. Vogt, Zeitschr. prakt. Geol., 1893, p. 6; 1894, p. 382; 1900, pp. 234, 370; 

1901, pp. 9, 180, 289, 327. J. P. Kemp, Nineteenth Ann. Rept. U. S. Geol. Survey, pt. 3, _ 

p. 377, 1899 ; School of Mines Quart., vol. 20, p. 323, 1899 ; vol. 21, p. 56, 1900; Zeitschr. 

prakt. Geol., 1905, p. 71. W. Lindgren, Science, vol. 16, p. 984, 1902. G. II. Williams, 

Am. Jour. Sci., 3d ser., vol. 33, p. 194, 1887. 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. ri 

In Zeitschr. prakt. Geol., 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, p. 

338, 1905. On the magmatic magnetites of Lapland, see 0. Stutzer, Neues Jahrb., Beil. 

Bd. 24, p. 548, 1907. .

6 See C. R. Van Hise, W. S. Bayley, H. L. Smyth, and .T. M. Clements, in Mon. U. S. 

Geol. Survey, vol. 28, 1897 ; vol. 36, 1899 ; and vol. 45, 1903.

« Mon. U. S. Geol. Survey, vol. 43, pp. 101-115, 1903. '\

d A treatise on metamorphism : Mon. U. S. Geol. Survey, vol. 47, p. 229, 1904.

0 See R. Brauns, Chemische Mineralogie, p. 231, 1896. ' ^

fCompt. Rend., vol. 39, p. 135, 1854.

a Idem, vol. 52, p. 1264, 1861.
ROCK-FORMING MINERALS. 285

action of gaseous hydrochloric acid upon ferric oxide at a red heat. 

Hematite is also produced, according to H. Arctowski,a 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 salt-cake 

furnaces of certain chemical works. 6 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. 0 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,* on comparing the volcanic mineral with the artificial 

product, found them to be crystallographically identical. W. 

Bruhns's experiment,6 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 Levyf 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, o 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,'1 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 pyr'ite 

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.

0 Zeitschr. anorg. Chemie, vol. 6, p. 377, 1894; Bull. Acad. Belg., 3d ser., vol. 27, p. 933. 

6 See H. Vater, Zeitschr. Kryst. Min., vol. 10,' p. 391, 1885 ; and B. Doss, idem, vol. 20, 

p. 566, 1892.

0 Personal communication from Prof. .C. E. Munroe.

* Zeitschr. Kryst. Min., vol. 18, p. 46, 1891. 

« Neues .Tahrb., 1889, pt. 2, p. 62. 

f Synthese des min6raux et des rocbes, p. 236.

» Mineralbildung in Schmelzmassen, pp. 215-217. Cf. also J. Morozewicz, Min. pet. 

Mitth., vol. 18, p. 84, 1898.

* Bull. U. S. Geol. Survey No. 228, p. 17, 1904.
286 THE DATA OF GEOCHEMISTRY. ^

Hematite alters into limonite, magnetite, pyrite, marcasite, and >'- 

siderite,a 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 C 

indirect, one or another of the above-named species having been , 

formed first. Titanium is a common impurity in hematite, and L. J. L 

Igelstrom,6 in a Swedish ore, found molybdenum in very appreciable 

amounts.

TITANIUM MINERALS.

Ilmenite. Khombohedral. . Composition, FeTiO3 . Molecular . 

weight, 152. Specific gravity, 4.5 to 5. Molecular volume, 30.4. 

Color, black; luster, submetallic. Hardness, 5 to 6.

Ilmenite, menaccanite, or titanic iron has been little investigated 

upon the synthetic side. W. Bruhns c prepare^ 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. 

It occurs with or replacing hematite in granite and syenites and as an -v 

essential constituent in diorite, diabase, gabbro, basalt, etc., often with ^ 

magnetite/' In these rocks it is one of the earliest minerals to separate. It is also found in metamorphic rocks, such as gneiss, mica 

schist, and amphibolite. A. von Lasaulx ° describes ilmenite as an 

alteration derivative of rutile.

The constitution of ilmenite has been much discussed. . Some au- - 

thorities have regarded it as an isomorphous mixture of Fe-jO., and 

Ti,O3 ; but C. Friedel and J. Guerin/ who prepared the latter compound artificially, do not favor this view. Ti2 03 as such has not been 

found as an independent mineral. T. Konig and 0. von der Pfordten f 

made various attempts to detect Ti2O3 in ilmenite and only met with 

failure. Since the mineral pyrophanite, MnTi03 , isomerphous Avith ~/- 

ilmeiiite, is known, and since, as S. L. Penfield and H. W. Foote ft 

have shown, ilmenite sometimes contains large admixtures of the 

molecule MgTi03 , the formula FeTiO;i 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 MgTiO3 is independently represented "by the mineral geikie- -^

a C. R. Van Hise, Treatise on metamorphism : Mon. U. S. Geol. Survey, vol. 47, p. 226, ^ 

1904.

''Zeitschr. Kryst. Min., vol. 25, p. 94, 1896.

c Neues .Tahrb., 1889, pt. 2, p. 65.

d 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, p. 321, 1884.

« Zeitschr. Kryst. Min., vol. 8, p. 54, 1884. ^

f Ann. chim. phys., 5th ser., vol. 8, p. 38, 1876. 

. "Ber. Deutsch. chem. Gesell., vol. 22, p. 1485, 1889.

* Am. Jour. Sci., 4th ser., vol. 4, p. 108, 1897. r '
BOCK-FORMING MINERALS. - 287

lite a 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;6 this substance is essentially 

titanite, sometimes accompanied by rutile.

Ps&udobrookite. Orthorhombic. Composition, ferric orthotitanate, Fe4 (Ti04 ) 8 . 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,0 who gave it the formula Fe«Ti05 and made it

ismorphous with andalusite, Al2Si05 . The natural mineral, however.

has the orthotitanate formula, as given above/'1

Perofskite. Isometric or pseudoisometric. Composition, calcium 

titanate, CaTiO3 . Molecular 'weight, 136.2. Specific gravity, 4. 

Molecular volume, 34. Color, yellow, ranging through orange and 

brown to grayish black. Hardness, 5.5.

Perofskite has been prepared synthetically by several chemists. 

J. J. Ebelmen c obtained it by. fusing titanic oxide with lime and 

potassium carbonate; and later f by the action of lime on an alkaline 

melt containing titanic oxide and silica. P. Hautefeuille ° heated a 

mixture of calcium chloride, titanic oxide, and silica to redness in a 

stream of moist carbon dioxide, or of hydrochloric acid, arid obtained 

perofskite crystals. L. Bourgeois h observed its deposition from various fused mixtures resembling natural magmas in composition. 

Finally, P. J. Holmquist' prepared perofskite by fusing together 

sodium carbonate, calcium carbonate, and titanic oxide, under special 

manipulative conditions.

Perofskite occurs both in eruptive and metamorphic rocks. It is 

found in melifite, lencite, and nepheline rocks, and in some peridotites; ^ and is among the earliest secretions. It is particularly charac-

"A recent description of geikielite by T. Crook and B. M. Tones is printed in Mineralog. 

Mag., vol. 14, p. 160, 100G. 

. * Zeitschr. Kryst. Min., vol. 6, p. 244, 1,882.

° Idem, vol. 20, p. 566, 1802. Doss gives a good bibliography of pseudobrookitc.

'' Established by A. Frenzel, Min. pet. Mittb., vol. 14, p. 121-; confirming the earlier 

analyses of A. Koch, G. Lattermann, and A. Cedarstriim. See E. S. Dana, System of 

Mineralogy, 6th ed., p. 232.

0 Compt. Rend., vol. 32, p. 710, 1851.

1 1dem, vol. 33, p. 528, 1851.

o Ann. cbim. phys., 4th ser., vol. 4, p. 163, 1865.

"Idem, 5th ser., vol. 29, p. 479, 1883.

* Bull. Geol. lust Upsala, vol. 3, p. 181, 1896-97.

i See G. H. Williams, Am. Jour. Sci., 3d ser., vol. 34, 1887, p. 137 ; J. S. Diller, Idem, 

vol. 37, p. 219, 1889.
288 . THE DATA OF GEOCHEMISTRY.

teristic of melilite basalt, being, according to A. Stelzner,0 the most 

faithful companion of melilite. At Catalao, Brazil, E. Hussak 6 

found a peculiar rock consisting of magnetite and perof skite; a titaniferous magnetite of a new kind. The mineral is also found in 

chlorite schist, limestone, quartz gneiss,0 etc. Hussak observed its 

alteration into titanic oxide, and K. Schneider d has described perofskite as derived from titanite.

Titanite. Monoclinic. Composition, CaTiSiO,,. 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 G 

prepared it by fusing a mixture of silica and titanic oxide with calcium chloride. L. Bourgeois f obtained it, but obscurely developed, 

by fusing together its constituent oxides, silica, titanic oxide, and 

lime. L. Michel^ 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 elscolite syenites, and is 

also common as a secondary mineral, derived by alteration from rutile 

or ilmenite. It is often associated with chlorite. At Green River, 

North Carolina, large crystals of sphene are found completely or 

partially altered into a yellow, friable, earthy substance which has 

been given the name of xanthitane. According to L. G. Eakins h 

this product is a hydrous titanate of aluminum. An alteration of 

titanite into rutile has been observed by P. Mann*- in the foyaite of

the Serra de Monchique; and B. Doss i has reported pseud omorphs 

of anatase after sphene.

Rutile. Tetragonal. Composition, TiO,. 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

" Neues Jahrb., Beil. Bd. 2, p. 390, 1883.

* Neues Jahrb., 1894, pt. 2, p. 297.

c See 0. Miigge, Neues Jahrb., Beil. Bd. 4, p. 581, 1886.

* Neues Jahrb., 1889, pt. 1, p. 99, 

" Ann. chim. phys., 4th ser., vol. 4, p. 129, 1865. 

r Idem, 5th ser., vol. 29, p. 474, 1883. 

"Compt. Rend., vol. 115, p. 830, 1892.

* Bull. U. S. Geol. Survey No. 60, p. 135, 1890." 

1 Neues Jahrb., 1882, pt. 2, p. 200. 

i Idem, 1895, pt. 1, p. 128.
BOCK-FOBMING MINEBALS. 289

_ 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 synthet-

 S .ically. Crystals of brookite were obtained by A. Daubree," by the

action of aqueous vapor upon titanic chloride at a red heat. By

heating amorphous titanic oxide to redness in a current of hydro-

' chloric acid gas, H. Sainte-Claire Deville and H. Caron 6 transformed

it into a crystalline modification, and similar results were obtained

by P. Hautefeuille and A. Perrey. 1? By .the prolonged heating of

titanic oxide with boric acid J. J. Ebelmen ll obtained rutile, and

i P. Hautefeuille G attained the same end when sodium tungstate or

vanadate Avas used as flux. H. Traube f also crystallized rutile from

rw 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, o by this method, prepared both rutile and anatase. Deville 

and Caron h also prepared rutile by heating titanic oxide with silica

V and oxide of tin to redness. By heating ilmenite and pyrite together

s at about 1,200°, L. Michel i obtained a mixture of rutile and pyrrhotite.

The three forms of titanic oxide were reproduced by P. Hautefeuille j by various modifications of the. same general pneumatolytic 

process. Potassium titanate and calcium chloride were heated in a

 current of hydrochloric acid mixed with air, and crystals were formed. 

Titanic oxide with potassium or calcium fluoride, or potassium silicofluoride, similarly treated, gave the same 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

 ff> 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,

r~ at or near the boiling point of cadmium, octahedrite was produced.

J s ' "Compt. Rend., vol. 29, p. 227, 1849.

*Idem, vol. 53, p. 161, 1861.

"Idem, vol. 110, p. 1038, 1890.

"Idem, vol. 32, p. 330, 1851. 

, ° Cited by Bourgeois, Reproduction artiflcielle des mine'raux, p. 85, 1884,

.' Neues Jahrb., Bell. Bd. 10, p. 470, 1895-96.

a Idem, 1894, pt. 2, p. 147. 

7 "Compt. Rend., vol. 53, p. 161, 1861.

< Idem, vol. 115, p. 1020, 1892.

 < i Ann. chiru. phys>, 4th ser., vol. 4, p. 129, 1865,

14399 Bull. 330 08 19
290 THE DATA OF GEOCHEMISTRY.

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 hornblende gneiss from Freiberg, A.. Bergeat a observed rutile, ilmenite, 

and titanite, which had formed as a single generation, and crystallized 

before the biotite. Rutile is also found as a secondary mineral, 

derived from ilmenite and titanite. C. Doelter 6 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. 6'

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, SnQ,. 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. Daubree d prepared cassiterite by the action of aqueous vapor 

upon tin tetrachloride in a red-hot porcelain tube. H. Sainte-Claire 

Deville e obtained it by passing gaseous hydrochloric acid over the

» Neues Jahrb., 1895, pt. 1, p. 232.

6 Min. pet. Mitth., vol. 11, p. 325, 1890.

"For a very full summary of the occurrence of zircon and the titanium minerals, 

especially brookite and anatase, see H. Thiirach, Verhandl. Phys. med. Gesell. Wiirzburg, vol. 18, No. 10, 1884. On the rutile of Nelson County, Virginia, see T. L. Watson, Bcon. Geol., vol. 2, p. 493, 1907.

"Compt. Kefld., vol. 29, p. 227, 1849,

'Idem, vol. 53, pi 361, 1801,
ROCK-FORMING MINERALS. ' 291

amorphous oxide of tin at a high temperature, and also by acting 

upon stannous chloride with aqueous vapor. According to A. Ditte," 

stannic oxide may be crystallized by fusion with calcium chloride; 

and its crystallization is mentioned by Deville and H. Caron l as 

having been effected by heating a fluoride of tin with boric oxide.

vv The formation of cassiterite as a furnace product has several times 

been observed, most recently by A. Arzruni ° and J. H. L. Vogt.d 

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 pneumato-

^ lytic 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.0

^ Cassiterite is rarely found as an original rock-forming mineral.

. M. von Miklucho-Maclay f has reported it accompanied by rjitile,

topaz, apatite, and tourmaline, as an inclusion in the mica of a gran7' ite. According to R. Beck, 3 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,'1 as an original constituent of pegmatite in the Carolinas. The relation's 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 i obtained it by heating zirconia in a 

current of silicon fluoride. Deville j 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 h obtained 

zircon when a mixture of silica,, zirconia, and lithium molybdate was 

- heated to 800°. Finally, K. Chrustschoff l effected the synthesis of

0 Compt. Rend., vol. 96, p. 701, 1883; 

"Idem, vol. 46, p. 766, 1858. 

K Zeitschr. Kryst. Min., vol. 25, p. 467, 1806. 

" rdem, vol. 31, p. 279. .

0 For a list of the minerals occurring with cassiterite, see W. Kohlmann, Zeitschr. 

Kryst. Min., vol. 24, p. 350, 1895.

r Nenes Jahrb., 1885, pt. 2, p. 88. 

-y</ a Zeitschr. Kryst. Min., vol. 33, p. 205, 1900. 

» Bull. U. S. Geol. Survey No. 293, 1906. 

' Compt. Rend., vol. 46, p. 764, 1858. 

l Idem, vol. 52, p. 780, 1861. 

fc ldem, vol. 107, p. 1000, 1888. 

' Neues Jahrb., 1892, pt. 2, p. 232.
292 'THE DATA OF GEOCHEMISTRY.

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.0 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 Ca. (P04 ) ;jF and Car, (P04 ) 3C1. 

Molecular weight, 504.5 for fluorapatite and 521 for chlorapatite.' 

Specific gravity, 3.17 to 3.23." Molecular volume, 159.1 to 161.6. 

Color, white, green, blue, red, yellow, gray, or brown. Hardness, 5.

The first synthesis of apatite was effected by A. Daubree,c who obtained it in crystals by passing the vapor of phosphorus trichloride 

over red-hot lime. N. S. Manross d fused sodium phosphate either 

with calcium chloride, calcium fluoride, or both together, and so obtained chlorapatite, fluorapatite, or a mixture of the two, resembling 

natural apatite, at will. This process, slightly modified, was also 

adopted by H. Briegleb 6 successfully. G. Forchhammer f 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/ who fused bone ash with ammonium chloride 

and either calcium chloride or fluoride, and also by A. Ditte,'1 who 

repeated Forchhanrmier's experiment. By heating calcium phosphate 

with calcium chloride and water, under pressure, at 250°, H. Debray * 

prepared chlorapatite. E. Weinschenk * also produced it by heating

0 For an elaborate discussion of the natural occurrences of zircon, see H. Thiirach, 

Verhandl. Phys. ined. Gesell. Wiirzburg, vol. 18, No. 10, 1884. For .zircon in the augite 

syenites'of Norway, see W. C. Brogger, Zeitschr: Kryst. Min., vol.46, p. 101, 1890.

6 For complete analyses of apatite, with a discussion of its variations, see .T. A. 

Voelcker, Ber. Deutsch. chem. Gesell., vol. 16, p. 2460, 1883. For manganese, magnesium, cerium, etc., in apatite, see B. S. Dana, System of Mineralogy, 6th ed., pp. 764, 765.

< Compt. Rend., vol. 32, p. 625, 1851.

d Liebig's Annalen, vol. 82", p. 353, 1852.

«Idem, vol. 97, p. 95, 1856.

t Idem, vol. 90, pp. 77, 322, 1854. 

 o Compt. Rend., vol. 47, p. 985, 1858.

* Idem, vol. 94, p. 1592, 1882.

i Idem, vol. 52, p. 44, 1861.

i Zeitschr. Kryst. Min., vol. 17, p. 489, 1890.
feOCK-FORMING MINERALS. 293

^ calcium chloride, ammonium phosphate, and ammonium chloride at

v' temperatures of 150° to 180° in a sealed tube. Apatite has been

reported as present in lead-furnace slags by W. M. Hutchins'1 and

J. PI. L. Vogt.& The composition of these slag products, however,

seems not to have been verified by analysis.

C Apatite is found in all classes of rocks igneous, metamorphic, and 

^ sedimentary. In the eruptives it appears as one of the oldest secretions from the magma. It is more common in femic rocks than in 

the more siliceous varieties. Titaniferous magnetites, like those of 

v Norway and the Adirondacks, often contain apatite in large amounts.

- - Apatite also appears as an important vein mineral; and in these occur-

' rences Vogt ° regards it as having been formed by pneumatolytic 

agencies. According to R. Miiller," apatite is strongly attacked by 

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,e under the name podolite. Its 

composition is represented by the formula 3CaH P2O8 .CaCO:n which is

,-v 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/ who fused the amorphous phosphates of cerium or

.^ yttrium with the corresponding chlorides. This process, however,

^"7 sheds no light upon their genesis in nature. 

, According to 0. A. Derby, o these two species, although they occur

i sparingly, 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 n also reported a titaniferous magnetite from Brazil, which

"Nature, vol. 36, p. 460, 1887. 

., '' Mineralbildung in Schmelzmassen, p. 263.

c See bis paper in Trans. Am. Inst. Min. Bng., vol. 31, p. 134, -1001, and also papers 

^ in Zeitschr. prakt. Geol., 1S94, p. 458 ; 1895, pp. 367, 444, 465. 

~^*" '' .Tahrb. K.-k. geol. Reichsanstalt, vol. 27, Min. pet. Mitth., p. 25, 1877. 

o Centralbl. Min. Geol. Pal., 1907, p. 279.

 -,-' r Compt. Rend., vol. 80, p. 304, 1875.

* Am. .Tour. Sci., 3d ser., vol. 37, p. 109, 1889 ; vol. 41, p. 308, 1891.

* Idem, 4tb ser., vol. 13, p. 211, 1902.
294 THE DATA OF GEOCHEMISTRY.

contained rnonazite, and still another association of monazite with 

graphite. On examining a number of granites and gneisses from 

New England, Derby a found several occurrences of monazite, and 

one of xenotime. W. Ramsay and A. Illiacus b also report the presence of monazite in the pegmatites of Finland. W. E. Hidden ° 

found crystals of xenotime, intergrown with zircon, in a decomposing 

granite in Henderson County, North Carolina.

Although it is an inconspicuous mineral in rocks, monazite sometimes accumulates in large quantities in residual sands, which, as a 

source of the rare earths, have important commercial value. The 

Brazilian monazite sands are described by E. Hussak and J. Rettinger/ who give very complete analyses of several samples. In North 

Carolina e the sands are derived from gneiss, and W. Lindgren f 

reports sands of granitic origin from the Idaho Basin, Idaho.

QUARTZ, TBIDYMITE, AND OPAL.

Quartz. Rhombohedral. Composition, silicon dioxide, SiO2 . 

Molecular weight, 60.4. Specific gravity, 2.65. Molecular volume, 

22.8. Colorless when pure, but often tinted yellow, violet, red, blue, 

green, brown, or black. Hardness, 7.

Tridymite. Hexagonal. Composition like quartz, Si02 - Specific 

gravity, 2.3. Molecular volume, 26,3. Colorless or white. Hardness, 7. Fuses at about 1,600°.

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.*'

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

a Proc. Rochester Acad. Sci., vol. 1, p. 198, 1891.

"Zeitschr. Kryst. Min., vol. 31, p. 317, 1899.

"Am. Jour. Sci., 3d ser., vol. 36, p. 380, 1888.

<* Zeitschr. Kryst. Min., vol. 37, p. 550, 1903. Another memoir on the Brazilian sands, 

by A. Lisboa, appears in Ann. Escola de Minas, No. 6, Ouro Preto, 1903.

" See report on monazite by H. B. C. Nitze, Sixteenth Ann. Rept. U. S. Geol. Survey, pt. 

4, p. 667, 1895. This memoir contains a valuable bibliography. Another general paper 

upon monazite, thorite, and zircon, by P. Truchot, may be found in the Reviie gen. sci., 

vol. 9, p. 145,'1898, and, translated into English, in Chem«« News, vol. 77, pp. 135, 145.

f Am. Jour. Sci., 4tb ser., vol. 4, p. 63, 1897. Also in Eighteenth Ann. Rept. U. S. 

Geol. Survey, pt. 3, p. 677, 1898. On 1 monazite sand in Queensland, see Bull. Imperial 

Inst., vol. 3, p. 233, 1905; and in the Malay Peninsula, idem, vol. 4, p. 301, 1906.

" See also A. L. Day and E. S. Shepherd on quartz glass, in Science, vol. 23, p. 670, 

1906. They found that quartz began to vaporize rapidly at about the temperature of 

melting platinum that is, between 1,700° and 1J50°.
ROCK-FORMING MINERALS. 295

quartz and often contain admixtures of amorphous or soluble silica,0 

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 Plombieres, in France, common opal and hyalite have been 

formed by the action of the waters upon an ancient Roman cement. 6' 

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 tridjinite there have been 

many researches. P. Schafhaiitl d simply heated a solution of colloidal silica in a Papin digester, and obtained a crystalline deposit 

of quartz-. H. de Senarmont 6 heated gelatinous silica with water 

and carbonic acid, sometimes also with hydrochloric acid, at temperatures of from 200° to 300°, with similar results. A. Daubree f 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; 9 and he furthermore observed 

its deposition from the waters of -Plombieres. h To K. Chrustschoff i 

we are indebted for a series of experiments, based fundamentally 

upon the original processes of Schafhaiitl 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 christobalite, at 240° to 300° quartz was formed, and 

at 310° to 360° tridymite. C. Friedel and E. Sarasin^ produced 

quartz by heating, in a steel tube, caustic potash, gelatinous silica, 

and amorphous alumina nearly to redness during fourteen to thirtyeight hours. When the experiment was conducted at a higher tem-

" For recent discussions upon the nature of chalcedony, etc., see A. Michel L6vy and 

E. Munier-Chalmas, Bull. Soc. min., vol. 15, p. 159, 1892; and F. Wallerant, idem, vol. 

20, p. 52, 1S97. The fibrous varieti'es, quartzine and lutecite, are especially considered.

6 For details concerning syntheses of opal, see L. Bourgeois, Reproduction artificielle 

des minc'raux, p. 93, 1884.

0 See A. Daubre"e, fitudes synthfitiques de geologic experimentale, p. 189, 1879.

d Cited by L. Bourgeois, Reproduction artificielle dea mincraux, p. 80, 18*84.

0 Ann. chim. phys., 3d ser., vol. 32, p. 142, 1851.

'Compt. Rend., vol. 39, p. 135, 1854.

o fitudes synthe"tiques de g<§ologie experimental, p. 158, 1879.

ft Idem, p. 175.

* Am. Chemist, vol. .3, p. 281, 1873. Compt. Rend., vol. 104, p. 602, 1887. Neues 

Jahrb., 1897, pt. 1, p. 240, Referate.

i Bull. Soc. min., vol. 2, pp. 113, -158, 1879.
296 THE DATA OF GEOCHEMISTRY.

...

perature they obtained tridymite and quartz side by side. W. 

Bruhns,0 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 6 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 c when 

glass was heated to 300° and upward with water alone. From the 

filtered and slowly cooled solution quartz and opal were deposited; 

the tridymite and feldspar were found in the decomposed and un dissolved residue. Exceptionally fine, doubly terminated, and clear 

crystals of quartz were obtained by E. T. Alien d 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 e 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. Rpse.f 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 o by fusing a rock rich in quartz also 

obtained tridymite; and K. B. Schmutz/1 who melted together a 

granite, sodium chloride, and sodium tungstate, found plagioclase, 

augite, and tridymite in the subsequently cooled mass. H. Schulze 

and Al Stelzner * found tridymite as an accidental product in the 

muffle of a zinc furnace; and C. Velain * observed it with ariorthite 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,fc as produced by the action of lightning upon a roofing 

slate. S. Meunier l fused silica, caustic potash, and aluminum fluoride

0 Neues Jahrb., 1889, pt. 2, p. 62.

6 Zeitschr. physika). Chemie, vol. 42, p. 572, 1903. Questioned by A. L. Day and E. S. 

Shepherd, Am. Jour."" Sci., 4th ser., vol. 22, p. 276, 1906.

c Centralbl. Min. Geol. Pal., 1906, pp. 339, 353. The authors discuss at length the 

relations between quartz and tridymite.

d Cited by Day and Shepherd, op. cit, p. 297.

« Proc. Roy. Soc. Edinburgh, vol. 11, p. 37, 1880.

'Ber. Deutsch. chem. Gesell., vol. 2, p. 388, 1869.

" Neues Jahrb., 1887, pt. 1, p. 205.

" Idem, 1897, pt. 2, p. 147.

i Idem, 1881, pt. 1, p. 145.

i Bull. Soc. min., vol. 1, p. 113, 1878.

* Centralbl. Min. Geol. Pal., 1904, p. 87.

' Compt. Rend., vol. Ill, p. 509, 1890.
ROCK-FORMING MINERALS. ° 297

together, and obtained tridymite. P. Hautefeuille ° 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,6 repeating this experiment with sodium 

molybdate, produced both quartz, and tridymite, and so, too, did P. 

Hautefeuille and J. Margottet c with lithium chloride as the flux.

During 1906 several investigations were made public which had 

for their purpose the determination of the transition point bet-ween 

quartz and tridymite. C. Johns d 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 e 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 f 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 tridymite Avas formed.

In all probability quartz and tridymite are polymers of the fundamental molecule Si(X. Tridymite is the lower, less complex polymer, 

and is therefore the more stable at high temperatures. The synthetic data all bear out this conclusion and show the difficulty of 

preparing pyrogenic quartz from magmatic mixtures. J. Morozewicz o 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 con-

«Bull. Soc. min., vol. 1, p. 1, 1878.

6 Cited by L. Bourgeois, Reproduction artiflcielle des minfiraux, p. 81, 1884.

c Bull. Soc. min., vol. 4, p. 244, 1881.

<"Geql. Mag., 1906, p. 118.

0 Centralbl. Min. Geol. 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°.

f Am. Jour. Scl., 4th ser., vol. 22; p. 276, 1906. Cf. also G. Stein, Zeitschr. anorg. 

Chemie, vol. 55, p. 159, 1907. On changes in quartz crystals at 570°, see O. Miigge, 

Neiies Jahrb. Festband, p. 181, 1907.

» Min. pet. Mitth., vol. 18, pp. 158-166, 1898. . -
298 ° THE DATA OF GEOCHEMISTRY.

nection 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 Levy,a 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. 6 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 Vogt's conclusions,0 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 

grounclmass of many rocks has similar composition. It is easy to 

understand from a consideration of the synthetic experiments why 

silica should form glass during the solidification of a magma, but 

the generation of quartz is a less simple matter. Lavas begin to 

solidify at temperatures above the transition point of quartz, and the

development.of the latter in such a rock as rhyolite is probably a

. result of very slow cooling, or even supercooling. That is, the temperature of the cooling mass is probably held for'a long time just 

below the transition point, so that quartz forms instead of tridymite. 

The formation of quartz, especially in plutonic rocks, is possibly 

also conditioned by pressure, and it is likely that magma tic 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 Pelee has been especially studied by A. Lacroix.(/ 

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

0 Synthese des mine'raux et des roches, pp. 88, 89. 

"F. W. Clarke, Bull. U. S. Geol. Survey No. 228, pp. 19, 20, 1904. 

c See p. 223, ante. 

' Bull. Soc'. mln., vol. 28, p. 56, 1905.
ROCK-FORMING MINERALS. 299

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.a 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 u 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,6 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.6 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.*7 These experiments by Spezia 

shed .much light upon the deposition of opal or quartz as a cementing 

material. There is also a suggestive experiment reported by Ramsay 

and Hunter,6 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, pre-

 5 : 

"See .T. P. Iddings, Bull. U. S. Geol. Survey No. 66, 1890, and Am. .Tour. Sci., 3d ser., 

vol. 36, p. 208, 1888, on quartz basalts from New Mexico ; and T. S. Dlller, Bull. U. S. 

Geol. Survey No. 79, 1891, on quartz basalts from California. Also a note by Diller, in 

Science, 1st ser., vol. 13, p. 232, 1889, on porphyritic quartz in eruptive rocks. In Bull. 

No. 79 Diller cites many references to similar rocks from other localities. Iddings discusses at some length the possible origin of the quartz, but reaches no certain conclusions.

"Jour. Chem. Soc., vol. 7G, pt. 2, p. 300, 1899.

c Idem, vol. 78, pt. 2, p. 595, 1900.

a Idem, vol. 80, pt. 2, p. 605, 1901. * For Spezla's original papers, of which these notes 

are abstracts, see Atti Accad. Torino, vol. 31, p. P°196, 1896; vol. 33, pp. 289, 876, 1898; 

vol. 35, p. 750, 1900; and vol. 36, p. 631, 1900-1901.

« Kept. British Assoc. Adv. Sci., 1882, p. 239.
300 THE DATA OF GEOCHEMISTRY.

sumably by organic matter, has repeatedly been noted.® Quartz may 

be dissolved and replaced by pseudomqrphs 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 FELDSPAKS.

Orthoclase. Monoclinic. Composition, KAlSi3 O8 . 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.

Albite. Triclinic. Composition, NaAlSi3 08 . Molecular, weight, 

263.3. Specific gravity, 2.605. _ Molecular volume, 101.1. Colors as 

in orthoclase, commonly white. Hardness, 6 to 6.5.

Anorthoclase. Triclinic. Intermediate in composition between 

albite and microcline.

Anorthite. Triclinic. Composition, CaAl2Si2O8 . Molecular 

weight, 279.1. Specific gravity, 2.765. Molecular volume, 100.9. 

Fuses at 1,532°. Color, white, grayish, reddish. Hardness, 6 to 6.5.

The mineral celsian may be a barium anorthite, BaAlSi2O8 . 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_._________________AboAr^ to AbgAiij.

Andesiue_____-___________AbaAiij to A^Ai^.

Labraclorite _..___-_____________________AbjAnj to AbjAiig.

Bytownite______________________AbjAiij to AbjAn,,.

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. On purely chemical grounds, the 

prevalent opinion is the more probable, and the observations of A. L. 

Day and E. T. Alien 6, upon the melting points of the feldspars support this conclusion. Their data are as follows:

"See C. W. Hayes, Bull. Geol. Soc. America, vol. .8, p. 213, 1896; M. L. Fuller, .Tour. 

Geol., vol. 10, p. 815, 1902 ; and C. H. S/nyth, Am. Jour. Sci., 4th ser., vol. 19, p. 277. 

1905. On the chemical reactivity of quartz, due to its solubility, see F. Riniie, Centralbl. 

Min. Geol. 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. angevv. 

Chernie, 1897, p. 393.

6 Am. Jour. Sci., 4th ser., vol. 19, p. 93, 1905.
BOCK-FOBMING MINEBALS. 

Melting points of feldspars.

301

Anorthite _... .___________ 1,532 

Ab,AnB __. ____________ 1,500 

__________________ 1,463

AbjAn, _-__ _________ 1,419

Ab2Aiii ___--__.. __._____ 1,367

Ab3An, ________________ 1,34.0

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. II. L. Vogt ft observed its formation in 

slags, and J. Morozewicz b repeatedly obtained feldspars varying 

from labradorite to nearly pure anorthite in his experiments with 

artificial magmas. Fouque and Levy c obtained anorthite directly 

from its constituents; and S. Meunier/' upon fusing silica, lime, and 

aluminum fluoride together, found sillimanite, tridymite, and anorthite in the 'resultant mass. Anorthite is also formed by the breaking 

down of other more complex silicates. A. Des Cloizeaux,6 by fusing 

garnet and .vesuvianite, obtained crystals which Fouque and Levy 

identified as anorthite; and similar results are reported, with much 

more .detail, by C. Doelter and E. Hussak.f Doelter g also found 

anorthite among the products formed by fusing epidote, axinite, chabazite, and scolecite. Finally, C. and G. Friedel n 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, Avere also obtained by Fouque and Levy i 

when mixtures of silica, alumina, sodium carbonate, and the proper 

monoxide were heated together to temperatures a little beloAv the 

point of fusion. 

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 with-

" Mineralbildung in Schmelzmassen, p. 181.

"Min. pet. Mitth., vol. 18, p. 156, 1898.

n Sy.nthese des mine'raux et des roches, p. 138.

A Compt. Rend., vol. Ill, p. 509, 1890.

c Manuel de rnine'ralogie, vol. 1, pp. 277, 543, 1862.

' Neues .Tahrb., 1884, pt. 1, p. 158.

"Idem, 1897, pt. 1, p. 1; Allgem. cheni. Mineralogic, p. 183.

" Compt. Rend., vol. 110, p. 1170, 1890.

* Synthese des rnine'i-aux et des roches, p. 145.
302 THE DATA OF GEOCHEMISTRY.

out difficulty near the anorthite end of the series,-become more and 

more unmanageable as we approach albite. This fact was observed 

by Fouque and Levy a and corroborated by Day and Alien, the latter 

having also shown that the viscosity of the alkaline compounds impedes their crystallization, at least within any reasonable time which 

can be allowed for a laboratory experiment. Albite, however, may be 

recrystallized, as J. Lenarcic 6 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 c 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,d 

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 e produced both quartz and orthoclase, and a potassium. 

feldspar was also obtained by Doelter f when a mixture corresponding 

to KAlSi04 was fused with potassium fluoride and silicofluoride. 

How these extraneous substances act is not clear. Day and Alien/ repeating a part of Hautefeuille's work, heated a powdered albite glass 

with sodium vungstate 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 h 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 * 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/ who heated an aqueous solution of dialyzed silica with a 

little alumina and caustic potash to 300° during several months, 

when quartz and orthoclase formed. C. and G. Friedel *? also prepared orthoclase by heating muscovite with. potassium silicate and 

water to 500°. In a series of experiments in which amorphous

a Synthese des mine'raux et des roches, pp. 142-145.

"Centralbl. Min. Geol. Pal., 1903, p. 705.

« Compt. Rend., vol. 84, p. 1301, 1877.

« Idem, vol. 85, p. 952, 1877.

' Idem, vol. 90, p. 830, 1880.

f Neues Jahrb., 1897, pt. 1, p. 1.

a Am. Jour. Sci., 4th ser., vol. 19, p. 117, 1905.

* Compt. Rend., vol. 92, p. 1374, 1881.

* Idem, vol. 97, p. 290, 1883. 

i Idem, vol. 104, p. 602, 1887.

* Idem, vol. 110, p. 1170, 1890.
ROCK-FORMING MINERALS. 303

silica was heated with potassium or sodium aluminate and water to 

520° in a steel bomb E. Baur a 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. 6 Among the latter only the pyroxenites, peridotites, leucitites, 

and nephelinites contain no feldspars, or at most contain them in 

quite subordinate quantities. The monoclinic alkali feldspars are 

especially characteristic of the more siliceous plutonic rocks, although 

they also occur in many eruptives and in metamorphic schists. In 

granite, for example, orthoclase, quartz, and muscovite are the conspicuous minerals. Albite is also found under similar conditions. 

In the less siliceous rocks, such as gabbro Or basalt, the plagioclases 

are more abundant, and the feldspars approach anorthite in composition as the,proportion of silica in a magma decreases. This statement, howeyer, 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." Orthoclase, probably of 

aqueous origin, sometimes occurs as a gangue mineral in metalliferous fissure veins.'*

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. Daubree e 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.

" Zeitschr. physikal. Chemle, vol. 42, p. 567, 1903. The paper is illustrated by diagrams based upon the phase rule.

"See F. W. Clarke, Bull. U. S. Geol. Survey No. 228, p. 20, 1904.

c For example, crystals of anorthite occur with epidote in the limestone of Phipsburg, 

Maine, and also with garnet, scapollte, etc., at Raymond, Maine. See Bull. U. S. Geol. 

Survey No. 113, p. 110, 1893, and Bull. No. 167, p. 69, 1900. C. H. Warren (Am. Jour. 

-Bel., 4th ser., vol. 11, p. 369, 1901) describes crystals of anorthite from the limestone of 

Franklin, New Jersey, near Its contact with granite.

d W. Llndgren (Am. .Tour. Scl., 4th ser., vol. 5, p. 418, 1898) has described an occurrence, 

of this kind near Silver City, Idaho. He gives a number of references to other lQc.aUt.les.

8 fitudes syQtWtlques de ge"ologie expe"rimentale, pp. 268-275; 1879,
304 THE DATA OF GEOCHEMISTRY.

To water charged with carbon dioxide 2 kilograms of orthoclase, 

after ten days of agitation, yielded 0.27 gram of K2O, 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.* 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 whoUy 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,6 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.0

LETJCITE AND ANALCITE.

Leiwite. Isometric. Composition, KAlSi2O6 . 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, NaAlSi 2O0 .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 d 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,6 

NH4AlSi2O6 . Furthermore, as the experiments of J. Lemberg f and

« Zeitschr. Deutsch. geol. Gesell., vol. 39, p. 559, 1887.

6 See J. W. Judd, Mineralog. Mag., vol. 8, p. 186, 1889, on the alteration of plagioclase 

into scapolite.

c For an example of this kind see F. A. Genth, Proc. Am. Phil. Soc., vol. 20, p. 392, 

1882. . ' .

 'Bull. Soc. min., vol. 19, p. 363, 1896. . -

" F. W. Clarke and G. Steiger, Bull. tl. S. Geol. Survey No. 207, 1902,

'Zeitschr. Deutsch. geol. Gesell., vol. 28,.pp. 537 et seq., 1876.
KOCK-FOBMING MINEEALS. 305

S. J. Thugutt ° 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,6 who also formed leucite, with other minerals, from 

various artificial magmas." By fusion of its constituents with potassium vanadate, P. Hautefeuille d 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 6 and A. Duboin.f C. Doelter/ by fusing a mixture 

equivalent to Al2 03 -t-2Si02 with sodium- fluoride, prepared a soda 

leucite, NaAlSi2O(j .

i When microcline. and biotite are fused together, leucite appears 

among the products;7* and Doelter^ found that it was formed when 

muscovite, lepidolite, or zinnwaldite was fused alone. It was also 

produced hydrochemically by C. and G. Friedel * 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 fc 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. 1 C. Friedel and E. Sarasin m prepared analcite by 

heating precipitated aluminum silicate with sodium silicate and water 

to 500° in a sealed tube. J. Lemberg n 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

0 Mineralchemische Studlen, pp. 100, 101, Dorpat, 1901.

* Synthese des mine'raux et des roches, p. 153.

c Bull. Soc. min., vol. 2, p. Ill, 1879 ; vol. 3, p. 118, 1880.

d Cited by L. Bourgeois, Reproduction artiflcielle des mine'raux, p. 130.

* Compt. Bend., vol. 90; p. 1009, 1880; vol. Ill, p. 509, 1890.

/ Idem., vol. 114, p. 1361, 1892.

"Neues Jahrb., 1897, pt. 1, p. 1.

ft Fouque" and Le"vy, Synthese des mine'raux et des roches, p, 77,

*Loc. cit.

' Compt. Rend., vol. 110. p. 1170, 1890.

* Idem, vol. 90, p. 1493, 1880; Bull: Soc. win,, vol. 3, p. 150, 1880.

1 Compt. Rend., vol. 94, p. 96, 1882.

m.Idem, vol. 97, p. 290, 1883.

"Zeitschr. Deutsch. geol. Gesell., vol. 39, p. 559, 1887.

14399 Bull. 330 08 2Q
 306 THE DATA OF GEOCHEMISTRY.

again, as we have already seen; but according to S. J. Thugutt a the 

reaction with andesine is not reversible.. The two alterations, therefore, are chemically unlike. Analcite may also be generated by alteration from elseolite and eegirite. 6 When formed with other zeolites, 

it is the earliest one to appear.

Leucite is a mineral characteristic of many recent lavas, but not 

found in the abyssal rocks. Its absence from the latter and older 

depositions may be due to its easy alteration into other species; but 

such an explanation is of course only tentative. Its 'formation takes 

place only when the potassium of a magma is in excess over the 

amount required to form feldspars. When the excess is small, leucite 

and feldspar may both appear; when it is large enough, leucite alone 

forms. Comparatively speaking, it is rather a rare mineral; a fact 

which is possibly explained by some observations of A. Lagorio.0 In 

an artificial leucite-tephrite magma, kept at a red heat, the difficultly 

fusible leucite crystallizes but. 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.'1

Analcite is most frequently found as a secondary mineral, the product of . zeolitization; and until recent years it was supposed to 

have no other origin. It was often noted in eruptive rocks, but it 

was supposed to be always 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,6 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 f interprets as analcite basalts equivalent to the 

similar leucite lavas. W. Cross g has described an analcite basalt from 

near Pikes Peak, Colorado, and has also identified primary analcite in 

the phonolites of Cripple Creeks The groundmass of a tinguaite 

from Manchester, Massachusetts, according to H. S. Washington,* 

consists of analcite and nepheline; and J. W. Evans'' has identified 

the mineral in a monchiquite from Mount Girnar, India. In the last

a Neues Jahrb., Beil. Bd. 9, p. 604, 1894-95.

" See W. C. Brogger, Zeitschr. Kryst. Min., vol. 16, pp. 223, 333, 1890. 

"Zeitschr. Kryst. Min., vol. 24, p. 293, 1895.

d On the formation of leucite in igneous rocks, see H. S. Washington, .Tour. Geol., vol. 

15, pp. 257, 357, 1907.

fl Am. Jour. Sci., 3d ser., vol. 45, p.. 286, 1893.

'Jour. Geol., vol. 4, p. 679, 1896.

' Idem, vol. 5, p. 684, 1897.

ft Sixteenth Ann. Kept. U. S. Geol. Survey, pt. 2, p. 36, 1895.

1 Am. Jour. Sci., 4th ser., vol. 6, p. 182, 1898.

> Quart. Jour. Geol. Soc., vol. 57, p. 38, 1901.
ROCK-FORMING MINERALS. 307

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.0 This is a dike rock containing analcite, plagioclase, 

orthoclase, and eegirine, in which the analcite forms 47 per cent of the 

mass. In the analcite diabase described by H. W. Fairbanks,'' 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.0

Alterations of leucite into analcite have been repeatedly observed, 

as in the Saxon Wiesenthal d and in the Highwood Mountains, Montana. 0 The most notable transformation of leucite, however, is into 

pseudomorphs of mixed orthoclase and nepheline/ The " pseudoleucite" crystals of Magnet Cove, Arkansas, are a mixture of this 

kind.

THE NEPHELITE GROUP.

Nephelite or elceolite. Hexagonal. Simplest empirical formula, 

NaAlSiO4 . 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 phacelite. Hexagonal. Composition, KAlSiO4. 

.Molecular weight, 158.6. Specific gravity, 2.5 to 2.6. Molecular 

volume, 6.1. Colorless. Hardness, 6.

Eucryptite. Hexagonal. Composition, LiAlSi04 . Molecular 

weight, 126.5. Specific gravity, 2.67. Molecular volume, 47.3. 

Colorless-or white. Only known as produced by the alteration of 

spodumene.

Kaliophilite and eucryptite are rare minerals, having slight geological significance. They are included here because of the light 

they shed upon the composition of nephelite. The formula given for 

the latter species is analogous to the formulae of kaliophilite and 

eucryptite, and is also that of the artificial mineral. Natural nephelite or elseolite always varies from the theoretical composition, and

"Jour. Geol., vol. 7, p. 431, 1899.

"Bull. Dept. Geology, Univ. California, vol. 1, p. 273, 1895. See also B. R. Young, 

Trans. Edinburgh Geol. Soc., vol. 8, p. 326, 1903, on analcite diabase in Scotland; C. W. 

Knight, Canadian Rec. Sci., vol. 9, p. 265, 1905, on an analcite-trachyte tuff from southwestern Alberta; and A. Pelikan, Min. pet. Mitth.,-vol. 25, p. 113, 1906, on two analcite 

phonolltes from Bohemia.

c W. C. Brogger, Zeitschr. Kryst. Min., vol. 16, p. 199, 1890.

d See A. Sauer, Zeitschr. Deutsch. geol. Gesell., vol. 37, p. 452, 1885.

" W. H. Weed and L. V. Pirsson, Am. Jour. Sci., 4th ser., vol. 2, p. 315, 1896.

f See Sauer, loc. clt.; .1. P. Williams, Ann. Rept. Geol. Survey Arkansas, 1890, vol. 2, 

p. 267 ; E. Hussak, Neues Jahrb., 1890, pt. 1, p. 166 ; and E. Scacchi, Rendiconti Accad. 

Napoli, vol. 24, p. 315.
308 THE DATA OF GEOCHEMISTRY.

approximates more nearly the formula Na(iK,Al8Si0 034. This 

variation is probably due, first, to isomorphous admixtures of kaliophilite, and possibly also to the presence of SiO3 or Si3O8 groups 

replacing a part of the normal SiO4 . The chemical equivalency of 

nephelite and kaliophilite is well shown by an experiment of J. 

Lemberg's.a He heated elseolite one hundred hours to 200° with a 

solution of potassium silicate, and obtained an amorphous product 

having the composition KAlSi04 .

P. Hautefeuille & prepared an artificial nephelite by fusing a mixture of silica and sodium aluminate with a flux of lithium vanadate. 

Fouque and Levy ° obtained the mineral more directly by fusing its 

constituents together, and so, too, did C. Doelter.^ Doelter's preparation agreed closely with the empirical formula NaAlSi04 . According to Fouque and Levy, nephelite is one of the minerals which crystallize most easily from fusion. S. Meunier G prepared nephelite less 

simply, by fusing silica, alumina, and soda "with cryolite; and A. 

Duboin f effected the synthesis of kaliophilite when potassium fluoride, alumina, and silica or potassium fluosilicate were fused together. 

By similar processes Doelter c obtained both nephelite and kaliophilite. C. and G. Friedel h 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 K. Hoffmann * when kaolin 

and dry sodium carbonate were heated together, and a similar result 

was reached by A. Gorgeu j and P. G. Silber,fc 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. l 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

a Zeitschr. Deutsch. geol. Gesell., vol. 37, p. 966, 1885. - 

6 Cited by Fouqu6 and Le"vy, loc. cit. 

c Synthese des mine"raux et des roches, p. 155. 

<* Zeitschr. Kryst. Min., vol. 9, p. 321, 1884. 

« Compt. Rend., vol. Ill, p. 509, 1890. 

'Idem, vol. 115, p. 56, 1892. 

a Neues Jahrb., 1897, pt. 1, p. 1. 

A Compt. Rend., vol. 110, p. 1170, 1890. 

* Liebig's Annalen, vol. 194, p. 5. 1878. 

i Ann. chim. phys., 6th ser., vol. 10, p. 145, 1887. 

fc Ber. Deutsch. chem. Gesell., vol. 14, p. 941, 1881.

' 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.
BOCK-FOEMIKG MINEEALS. 309

excess of soda in a magma over the amount required to form feldspars, and it is one of the latest minerals to be deposited."

Nephelite and elaeolite are peculiarly subject to alteration.6 Natrolite, analcite, hydronephelite, thomsonite, sodalite, muscovite, and 

kaolin are among the products thus formed. Eucryptite also alters 

into muscovite. 0

THE CANCRINlTE-SODAiLITE 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. Color commonly yellow, but also white, gray, greenish, bluish, 

or reddish. Hardness, 5 to 6.

Sodalite.A Isometric. Composition normally Al3Na4Si3 012Cl; 

but variable. Molecular weight, 486. Specific gravity, 2.2. Molecular volume, 221. Color, white, gray, greenish, yellowish, reddish,

jry often bright blue. Hardness, 5.5 to 6.

Hauynite. Isometric. Composition, Al3Na3CaSSi3 010, 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 haiiynite, but 

without calcium, Al3NasSSi3 0lc . 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 microsomrnite, 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; e the three isometric species are 

written as interpreted by W. C. Brogger and H. Backstrom/ who 

have shown their relationship to'the garnet group. Under sodalite, 

hoAvever, more than one compound may be included, as the experiments of J. Lemberg 9 and S. J. Thugutt h seem to indicate. The two 

last-named authorities regard these minerals as double molecular

 compounds of a silicate like nephelite with sodium carbonate, chlo-

" See the experiments of J. Morozewicz, MIn. pet. Mitth., vol. 18, 1898, pp. 1, 105. 

j Compare also J. Lenarci6, Centralbl. Min. Geol. Pal., 1903, pp. 705, 743.

» See W. C. Brogger, Zeitschr. Kryst. Min., vol. 16, pp. 223 et seq., 1890. 

« See G. J. Brush and E. S. Dana, Am. Jour. Sci., 3d ser., vol. 20, p. 266, 1880. 

d A. variety of sodalite containing some sulphur has been named hackmannite by L. H. 

Borgstrom, Zeitschr. Kryst. Min., vol. .37, p. 284, 1903. ' 

/ Bull. U. S. Geol. Survey No. 125, pp. 22-24, 1895. 

"^ r Zeitschr. Kryst. Min., vol. 18, p. 209, 1891.

a Zeitschr. Deutsch. geol. Gesell., vol. 37, 1885, p. 969.

 ^ * Mineralchemische Studien, Dorpat, 1.891.
310 THE DATA OF GEOCHEMISTRY.

ride, 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.0 A discussion of these salts, however, would .lead us too far afield.

An artificial cancrinite was obtained by Lemberg 6 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 elasolite.0 Labradorite, heated to 

215° with sodium carbonate solution, also gave him cancrinite^ C. 

and G. Friedel e prepared a hydrous cancrinite by heating muscovite 

to 500° in a solution of sodium carbonate and caustic soda. With 

sodium sulphate in place of the carbonate, a hydrous noselite was ' 

formed.f The same authors obtained sodalite by treating muscovite 

at 500° with sodium chloride and caustic soda.*7 Lemberg h produced 

sodalite by fusing nephelite with common salt; and the fusion of 

elgeolite or sodalite with sodium sulphate gave noselite.* In shojj 

the experiments, of Lemberg, which were very numerous, proved tfll 

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-' prepared sodalite by heating natrolite ' A 

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°.fc Sodalite, then, has been derived by artificial 

means from elseolite, muscovite, and kaolin. It was also obtained by' 

Z. We37 berg l 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 prepared 

noselite, hauynite, and sodalite by purely pyrochemical methods, 

equivalent to those which produce these minerals in volcanic rocks. X 

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,

a A "chromate sodalite," containing Na2Cr04 , has lately been described by Z. Weyberg, 

Centralbl. Min. Geol. Pal., 1904, p. 727. It differs from the hydrated compound prepared ^ 

by Thugutt.

6 Zeitschr. Deutsch. geol. Gesell., vol. 35, p. 593, 1883.

" Idem, vol. 37, p. 963, 1887.

d Idem, vol. 39, p. 559, 1887. <

» Bull. Soc. min., vol. 14, p. 71, 1891.

t Idem, vol. 13, p. 238, 1890.

« Compt. Rend., vol. 110, p. 1170, 1890.

^Zeitschr. Deutsch. geol. Gesell., vol. 28, p. 602, 1876.

* Idem,'vol. 35, p. 590, 1883. . ^

i Neues .Tahrb., Beil. Bd. 9, p. 576, 1894-95.

fc Mineralchemische Studien, p. 18. \

1 Centralbl. Min. Geol. Pal., 1905, p. 717.

m Min. pet. Mitth., vol. 18, pp. 128-147, 1898.
ROCK-FORMING MINERALS. 311

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; eloeolite, 

similarly treated, yielded .a substance richer in chlorine. Morozewicz concludes that two kinds of sodalite exist; to one he gives 

the formula 2(Na0Al,Si.-,08 )+NaCl, while the other agrees with 

3(Na2Al2Si 2O8 )+2NaCl."

Cancrinite occurs only in elseolite syenite, closely associated with 

nephelite and sodalite. It alters into a zeolitic substance, " spreustein," in which natrolite is the predominating mineral.0 Crystallized 

sodalite is also found in trachyte and phonolites, in which it separates 

after augite.& 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, MgSiO?) , but generally 

with admixtures of FeSiO,.,. When 10 to 12 per cent of the latter salt 

is present the mineral is known as bronzite. Minimum molecular 

weight, fOO.S. 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 

FeSiO3 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 pyr- 

, oxene group, are to be regarded as mixtures of the two isomorphous 

salts MgSiO3 and FeSiO3 . 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.

v The first synthesis of supposed enstatite was made by J. J. Ebelmen,c who fused silica, magnesia, and boric oxide together. A. 

Daubree^ obtained it repeatedly in his attempts to reproduce the 

characteristics of meteorites, when meteoric stones and magnesian

"See W. C. Brogger, Zeitschr. Kryst. Min., vol. 16, p. 240, 1800; also L. Saemann and 

F. Pisani, Ann. chini. Phys., 3d ser., vol. 67, p. 350, 1863. 

Y b On sodalite syenite from Square Butte, Montana,. see W. Lindgren, Am. Jour. Scl.,

3d ser., vol. 45, p. 286, 1893.

/ " Ann. chim. phys., 3d ser., vol. 33, p. 58, 1851. 

" Corapt. Rend., vol. 62, pp. 200, 369, 660, 1866.
312 . THE r>ATA OF GEOCHEMISTRY.

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 ° produced a silicate which he identified with enstatite, by dissolving amorphous silica in molten magnesium chloride, and S. Meunier 6 effected its synthesis by acting on 

metallic magnesium with silicon chloride and water vapor.

Later investigations, however, by F. Fouque and A. Michel Levy,0 

and also by J. H. L. Vogt^ 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 6 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. ET 

Clement f it has been found that magnesium metasilicate exists in 

four modifications, two being pyroxenes and two amphiboles. The 

monoclinic pyroxene is formed whenever a melt having its composition is allowed to crystallize at temperatures a little below 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. The monoclinic 

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,*7 the orthorhoma Ann. chim. phys., 4th ser., vol. 4, p. 174, 1S65. 

 "Compt; Rend., vol. 90, p. 349, 1880; vol. 93, p. 737, 1881. 

c Synthese des mineraux et .des roches, 1882. 

d Mineralbildung in Schmelzmassen, 1892, p. 71. 

6 Loc. cit.

'Am. Jour. Sci., 4th ser., vol.' 22, p. 385, 1906. 

a Min. pet. Mitth., voJ. 18, p. 110, 1898.
ROCK-FORMING MINERALS. 313

bic pyroxenes separate from metasilicate magmas when the ratio 

Mg-j-Fe: Ca is 3:1 or greater. Both species undergo alteration, 

through hydration, into talc a 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.

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,6 and has been 

repeatedly observed in slags.0' Wollastonite has also been found in 

slags, but rarely.d E. Hussak,6 however, by fusing and slowly cooling a glass containing silica, soda, lime, and boric acid, obtained 

crystals of wollastonite. C. Doelter f also effected the synthesis of 

wollastonite by fusing calcium metasilicate with sodium fluoride.

According to E. T. Alien and W. P. White,3 .wollastonite is stable 

only below 1,180°, 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,'1 is that the rocks containing free calcium 

metasilicate miist 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 i has described a rock from Hereroland, Africa, which consisted of wollastonite and diopside in nearly 

equal proportions. The alteration of wollastonite to ordinary pyrox-

« See C. H. Smyth, School of Mines Quart., vol. 17, p. 333, 1896.

'' See L. Bourgeois, Bull. Soc. min., vol. 5, p. 13, 1882 ; A. Gorgeu, idem, vol. 10, p. 

273, 1887; and C. Doelter, Neues Jahrb., 1886, pt. 1, p. 119.

c See .T. H. L. Vogt, Mineralbildung in Schmelzmassen, pp. 34-80, 1892.

<* See Vogt, loc. cit, and P. Heberdey, Zeitschr. Kryst. Min., vol. 26, p. 22, 1890.

« Zeitschr. Kryst. Min., vol. 17, p. 101, 1890.

r Min. pet. Mitth., vol. 10, p. 83, 1888.

"Am. Jour. Sci., 4th ser., vol. 21, p. 89, 190G. See also A. L. Day, E. S. Shepherd, 

and F. E. Wright, idem, vol. 22, p. 265.

 Prefatory note .to the memoir by Alien and White.

 'Min. pet. Mitth., vol. 8, p. 230, 1887.
314 THE DATA OF GEOCHEMISTRY.

ene has been reported by C. H: Smyth.a The secondary mineral 

pectolite, HNaCaoSiaO,,, is regarded as a derivative of wollastonite.

Diopside. Monoclinic. Composition, CaMgSLOG . 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.

Hedenbergite. Monoclinic. Composition, CaFeSi,,00 . Molecular 

Aveight, 248.8. Specific gravity, 3.5 to 3.6. Molecular volume, 70. 

Color, grayish green to black. Hardness, 5 to 6.

BetAveen 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 A^ariations may represent mixtures of the simple salts MnSiO3 and ZnSiO:! Avith the lime, 

magnesia, and iron silicates; but the commingled salts are probably 

more complex. Rhodonite, MnSiOH , 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. 6 A. Daubree,0 on heating \vater to incipient redness in a glass tube, obtained crystals of diopside. G. Lechartier d effected the synthesis of these pyroxenes by fusing silica, 

lime, and magnesia Avith an excess, of calcium chloride. When ferric 

oxide Avas added to the mixture, iron pyroxenes Avere formed. In 

the experiments of J. Morozewicz e with artificial magmas these minerals Avere deposited AArhen the ratio Mg-(-Fe: Ca Avas less than 3:1.

Dr. E. T. Alien informs me that he has prepared diopside by 

directly fusing its constituent oxides together, and that it is easily

recrystallized from solution in molten calcium chloride.'

The monoclinic pyroxenes are common in eruptive rocks and the 

crystalline schists. The variety known as diallage is especially 

characteristic of gabbro. They also occur as secondary minerals. R. 

Brauns f has observed the variety salite, as formed in a picrite by the 

action of aqueous solutions upon olivine and plagioclase.

Acmite or cegirite. Monoclinic. Normally NaFe'"Si,>O6 , but 

often containing ferrous arid lime silicates in isomorphous admixture. 

Molecular Aveight, 231.7. Specific gravity, 3.53. Molecular volume. 

65.6. Color, brownish, greenish, to black. Hardness, 6 to 6.5.

0 Am. .Tour. Sci., 4th ser., vol. 4, p. 309, 1897.

6 See citations in L. Bourgeois, Reproduction artiflcielle des mineraux, pp. 115 11G ; 

and Fouque" and L6vy, Synthese des mine'raux et des roches, pp. 102-103. Also G. J. 

'Brush, Am. Jour. Sci., 2d ser., vol. 39, p. 132.

c fitudes synthetiques de geologic expgrimentale, pp. 159-176.

d Compt. Rend., vol. 67, p. 41, 186S. Compare A. Gorgeu, Bull. Soc. min., vol. 10, pp. 

273, 276, 1887. - .

0 Min. pet. Mitth., vol. 18, pp. 123 et seq., 1898. See also J. H. L. Vogt, Die Silikatschmelzlosungen, pt. 1, pp. 28-49, -1903.

fNeues Jahrb., 1898, pt. 2, p. 79.
ROCK-FORMING MINERALS. 315

Jadeite. Monoclinic. Composition, NaAlSi2O0 . Molecular weight. 

202.0. Specific gravity, 3.34. Molecular volume, 60.8. Color, white 

and various shades of green. Hardness, 6.5 to T.

Spodumene. Monoclinic. Composition, LiAlSi2 00 . Molecular 

weight, 186.9. Specific gravity, 3.17. Molecular volume, 58.9. Color, 

white, yellow, green, and amethystine. Hardness, 6.5 to 7. Hiddenite is the emerald-green gem spodumene from North Carolina. 

Kunzite is the amethystine gem variety from California.

These alkali pyroxenes, as they are often called, are interesting 

on account of their constitutional similarity. Acmite, however, is 

the most important as a rock-forming mineral, although in the interpretation of mixed pyroxenes the jadeite molecule must often be taken 

into account. Spodumene occurs only sporadically usually, if not 

always, in granites 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," 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, 

LiAlSi0.1? and albite, NaAlSi;!O8 . Then, by the further action of 

potassium salts, the eucryptite is altered into muscovite, KH2Al;tSi3O12 . 

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.0 C. Doelter,(Z however, from the fusion of an artificial mixture of the oxides, obtained some acmite. H. Biickstrom c 

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 * also obtained acmite by fusing a mixture of the composition 2Si02 -|-Fe2 03 -|- 

Na.,0 with a large excess of sodium chloride. According to J. Morozewicz/ the acmite-jadeite compounds form in metasilicate magmas

< Ann. New York Acad. Sci., vol. 1, p. 318, 1879.

"Am. Jour. Sci., 3d ser., vol. 20, p. 257, 1880. '

C M. Vucnik, Centralbl. Min. Geol. Pal., 1904, p. 369.

<*Neues Jahrb., 1897, pt. I, p. 16."

 Bull. Soc. min., vol. 16, p. 130, .1.893.

'Centralbl. Min. Gcol. Pal., 19Q5, p. 717.

" Min. pet. Mltth., vol. 18, p: 123, 1898.
316 THE DATA OF GEOCHEMISTRY.

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 elseolite 

syenite. Concerning the petrologic relations of jadeite less is 

known; but S. Franchi a has identified the mineral as an essential 

constituent of certain eruptive rocks in Piedmont. - Acmite or 

segirite, according to W. C. Brogger,6 alters into analcite. J .Lemberg,c by heating spodumene or jadeite with alkaline solutions under 

pressure, also obtained analcite. Jadeite alone is slowly attacked, 

but the glass resulting from its fusion is altered readily. It is 

noticeable that jadeite and dehydrated analcite have the same empirical composition; but the denser jadeite molecule is doubtless the 

more complex. The one is a polymer of the other. These alterations, natural or artificial, emphasize the constitutional similarity 

of the three alkali pyroxenes.

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 K/'Al2 Si00 , which, however, is hypothetical. The rare mineral kornerupine or prismatine, however, has 

the formula MgAl,SiOf> , 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 were all made in 

the laboratory of the United States Geological Survey:

Analyses of augite.a

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. Ffom tinguaite, Two Buttes, Colorado. Analyzed by Hillebrand.

D. From granite, Silver Cliff, Cplorado. Eakins, analyst.

E. From a dike, Silver Cliff. Eakins, analyst.

F. From basalt, Mount Taylor region, New Mexico. Analyzed by T. M. Chatard.

"Rendiconti Accad. Lincei, 1900,'vol. 9, pt. 1, p. 349.

6 Zeitschr. Kryst. Min., vol. 16, p. 333, 1890. Brogger cites many references to the 

literature of acmite.

c Zeitschr. Deutsch. geol. Gesell.,"vol. 39, p> 584, 1887. 

*From Bull. U. S. Geol. Survey No. 220, pp. 33, 34, 1903.
ROCK-FORMING MINERALS. 317

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

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

Alj03 .. ...................................

CrjOs.. ...................................

Fea03 . ....................................

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

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

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

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

K»0 ......................................

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

P,05 . .....................................

HS 0.... ..................................

A.

45.23

4.28

7.73

2.95

4.07

.07

12.25

23.37

.47

.12

.05

.37

100.96

B.

40.10

7.95

8.30

12.37

22.54

100.26

C.

47.54

1 00

4.14

5.64

6.42

.36

10.05

21. 57

1.38

.12

100. 22

D.

48.72

9.27

3.77

6.34

.34

14. G7

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

1.30

8.15

.20

13. 52

19.33

.33

.11

.06

,20

99.85

Augite is a common mineral in slags,a and is easily produced from 

its constituents by simple fusion. 6 It was repeatedly obtained by 

Fouque and Levy,0 both by itself and in association with other minerals, in their classic experiments upon the synthesis of rocks. J. 

Morozewicz d also has found both ordinary augite and the alkaline 

varieties in the products yielded by his artificial magmas. The molecule RAl,,Si06 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. 0 Biotite and clinochlore 

also yield it among the products of their thermal decomposition.' 

C. Doelter^ 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 KAl2SiO0 . According to 

J. Lenarcic/1 magnetite and labradorite, fused together, yield augite. 

So, too, does hedenbergite when fused with anorthite, albite,* or 

corundum.'

Several other minerals in addition to those already named are 

classed as pyroxenes, but they are too rare to need more than a passing mention here. The so-called zircon pyroxenes, rosenbuschite, 

lavenite, wohlerite, and hiortdahlite are found in the elseolite syenites 

of Norway. The triclinic babingtonite is interesting, for it contains, 

in addition to the molecular types found in the other pyroxenes, the

" See ,T. IT. L. Vogt, Mineralbildung in Scbmelzmassen, p. 34.

6 For early syntheses, see Fouqu<§ and L6vy, Synthese des mine'raux et des roches, p. 102.

c Op. cit., pp. GO, G7, 105.

* Min. pet. Mltth., vol. 18, pp. 107, 113, 120, 123, 124, 1898.

« C. Doelter, Allgem. chem. Mlneralogie, pp. 182, 183.

t Doelter, Neues .Tahrb., 1897, pt. 1, p. 1.

" Idem, 1S84, pt. 2, p. 51.

»Centralbl. Min. Geol. Pal., 1903, pp. 705, 743.

* M. VuCnik, idem, 1904, pp. 300, 342. 

1 B. Vukits, idem, 1904, p. 705.
318 THE DATA OF GEOCHEMISTRY.

ferric silicate Fe2 Si3O9 . It has been found not only as a natural 

mineral, but also as a furnace product in slag.a

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,6 chlorite, serpentine, talc, mica, garnet, epidote, and glauconite. The pyroxenes, 

furthermore, occur as important secondary minerals; sometimes as 

the product of contact metamorphism in limestones, sometimes as 

marginal zones derived from olivine.6' Diallage and hypersthene 

rocks alter into amphibolites.*

NOTE. For theoretical discussions upon the constitution of the pyroxenes, see 

G. Tscherinak, Jahrb. K.-k. geol. Reichsanstalt, vol. 21, 1871, Min. pet. Mitth., 

p. 17. C. Doelter, Min. pet. Mitth., vol. 2, p. 193, 1879. F. W. Clarke, Bull. 

U. S. Geol. Survey No. 125, 1895. J. W. Eetgers, Zeitschr. physikal. Chemie, vol. 

16, p. 614, 1895. P. Mann, Neues Jahrb., 1884, pt. 2, p. 172. A. Merian, idem, 

Beil. Bd. 3, p. 252, 1884. The literature upon this subject is very voluminous.

THE AMPHIBOI/ES.

Anthophyllite. Orthorhombic. Composition like enstatite or 

bronzite (MgFe) SiO3 , 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. 6

Tremolite. Monoclinic. Composition, CaMg3Si4 012 . 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/

" See L. Buchrucker, Zeitschr. Kryst. Min., vol. 18, p. 626, 1891.

0 See H. Ries, Ann. New York Acad. Sci., vol. 9, p. 124, 1896-97, in an important 

memoir upon the pyroxenes of New York.

c See G. H. Williams, Am. Jour. Sci., 3d ser., vol. :U, p. 85, 1886, and F. D. Adams. 

Am. Naturalist, vol. 19, p. 1087, 1885. Williams gives a number of references to alterations of this kind.

" Williams, Am. Jour. Sci., 3d ser., vol. 28, p. 258, 1884.

." An iron anthophyllite, FeSi03, associated with the fayalite of Rockport, Massachusetts, has been described by <~VH. Warren, Am. Jour. Sci., 4th ser., vol. 16, p. 337, 

1903.

f See G. P. Merrill, Proc. U. S. it. Mus., vol. 18, p. 281, 1896, for a good summary of 

our knowledge of asbestos.
BOCK-FORMING MINERALS. 319

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. Griinerite is the ferrous silicate, FeSiO3 alone.a Dannemorite is a similar iron-manganese metasilicate. In richterite, 

which has a similar general formula, alkalies appear, up to 9 per cent 

or more. Many analyses of these minerals show the presence of water 

in them, and also of fluorine.

Anthophyllite and gedrite are essentially Archean minerals, occurring especially in hornblende gneisses and schists. Tremolite is found 

as an accessory mineral in metamorphic limestones and dolomites. 

Actinolite is also a mineral of the metamorphic rocks. In the iron 

regions near Lake Superior actinolite-magnetite schists are common. 1'

Anthophyllite, tremolite, and actinolite alter easily into talc, serpentine, and calcite. The reverse alteration, of talc into anthophyllite, 

has been reported by Genth.c Uralite, which has ordinarily the 

composition of actinolite, is an amphibole derived by alteration from 

similarly constituted pyroxenes.**

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.6 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 Edenvillo, New York. Stanley, analyst.

°A. C. Lane and F. F. Sharpless (Am. Jour Set., 3d ser., vol. 42, p. 505, 180].) have 

applied the name griinerite to a ferromagnesian amphibole like cnmmingtonite.

"See W. S. Bayley, Am. Jour. Sci., 3d ser., vol. 40, p. 176, 1893. Also C. R. Van Hiwc, 

C. K. Leith, and others, in Mon. U. S. Geol. Survey, vol. 28, 1897 ; vol. 43, 1903.

0 Proc. Am. Phil. Soc., vol. 20, p. 393, 1882.

<*0n the theory of uralltizatlon see L. Duparc and T.'i-Iornung, Compt. Rend., vol. 139, 

p. 223, 1904.

« Am. Jour. Scl., 4th ser., vol. 23, p. 23, 1907. 7
320 THE DATA OF GEOCHEMISTRY.

C. From Cornwall, New-.York. J. L. Nelson, analyst." 

D. From Monte Somma, Italy. Stanley, analyst. 

E. Basaltic hornblende, Bilin, Bohemia. Stanley, analyst. 

F. .From Grenville Township, Quebec, Stanley, analyst.

SiOj........................... ...

TiO,./..... ...............................

Alj03 .. ...................................

Pc2O3 .....................................

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

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

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

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

KjO... ...................................

Na»O. ....................................

HjO................................. ...

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

K^

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

a 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

14.15

11.96

1.98

3.16

.41

.03

.13

100. 46 

.01

100.45

F.

45. 79

1.20

11.37

.42

.42

39

21.11

12.71

1.69

2.51

.67

2.76

., 101.04 

' 1.16

99.88

The synthesis of hornblende was first effected by K. Chrustschoff. 6 

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,0 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,** 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,6 when anthophyllite or hornblende is fused, 

a pyroxene, sometimes with olivine, is formed. According -to A.

°Am. Jour. Sci., 4th ser., vol. 15, p. 227, 1903. Fluorine determination added to 

Nelson's analysis by Stanley.

"Compt. Rend., vol. 112, p. 677, 1891.

"Neues Jahrb., 1897, pt. 1, p. 1.

" Am. Jour. Sci., 4th ser., vol. 22, p. 385, 1906.

» Zeitschr. Deutsch. geol. Gesell., vol 37, p. 10, 1885,
ROCK-FORMING MINERALS. 321

Lacroix,0 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, riot 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. 0

Ordinarily, the constitution of the hornblendes is supposed to be 

analogous to that of augite, metasilicates of the form ESi03 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 formulae 

of diopside, MgCaSi2 00 , and tremolite, CaMg3Si4012 . The latter 

assumption, however, is not well grounded, for the amphiboles, as a 

rule, are lower in specific gravity than the corresponding pyroxenes, 

which indicates that their molecules are really less condensed. The 

true molecular weights are unknown; and it is quite possible that 

they are better represented by polymeric symbols, such as R8Si8 024 

in the pyroxene series and R4Si4O12 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 d 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 e regards them as mixtures of 

actinolite with an orthosilicate isomeric \vith garnet, R'^R'^SigOj;,, 

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 f also assumes the presence

» Min6rnlogie de la France, vol. 1, pp. 668-669, 1893-1895.

"Mln. pet. Mitth., vol. 4, p. 450, 1882.

0 Neues Jahrb., 1885, pt. 2, p. 90.

''Am. Jour. Sci., 3d ser., vol. 38, p. 154, 1889. See also P. W. Clarke, Bull. U. S. 

Geol. Survey No. 125, 1895.

o Neues Jahrb., 1884, pt. 2, p. 143.

t Sitzungsb. Akad. Wlen, vol. 85, pt. 1, p. 153, 1882. See also H. Haefcke, Doct. Dlss., 

Gottingen, 1890.

14399 Bull. 330 08 21
322 THE DATA OF GEOCHEMISTKY.

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," has very nearly orthosilicate ratios; and so also 

has a variety from Dungannon, Ontario, studied by F. D. Adams and 

B. J. Harrington. 6 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."

Glaucophane. Monoclinic. Normally NaAlSi2O6 .(FeMg)SiO3 , 

but variable amounts of the calcium metasilcate may be present also. 

Color, blue, bluish black, or grayish. Specific gravity, 3 to 3.1. 

Hardness, 6 to 6.5.

Riebeckite. Monoclinic. Composition, 2NaFeSi2 00 .FeSiO;,. Color, 

black.

C-rocidolite. Composition, NaFeSi 2O0 .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,<* is an asbestiform variety of glaucophane in which 

aluminum has been replaced by ferric iron. Crossite, from California, according to C. Palache,0 is intermediate between riebeckite 

and glaucophane.

Arfvedsonite. Monoclinic. The composition is approximately 

4Na2SiO3H-13FeSiO3 +3CaSiO3 +Fe''Al2SiO0 , but probably variable. 

Specific gravity, 3.45. Color, black. Hardness, 6.

Barkevikite. Intermediate between arfvedsonite and hornblende.^ 

Color, black. Specific gravity, 3.43.

« Am. Geologist, vol. 21, p. 370, 1898.

b Am. Jour. Sci., 4th ser., vol. 1, p. 210, 1896.. " Hastingsite."

0 An.interpretation of the amphiboles quite different from that of Tschermak has been 

proposed by S. L. Penfleld and F. C. Stanley, Am. Jour. Sci., 4th ser., vol. 23, p. 23, 

1907. They assume the existence of bivalent molecules, A12OP2, A120(OH) 2, AI 203R", 

and AloO4R"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.

* Sitzungsb. Akad. Wieu, vol. 100, pt. 1, p. 176, 1891.

« Bull. Dept. Geology, Univ. California, vol. 1, p. 181, 1894.

' For a discussion of the composition of barkevikite, see W. C. Brogger, Zeitschr. Ki-yst. 

Min., vol. 16, p. 412, 1890.
ROCK-FORMING MINERALS. 323

/Enigmatite. 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'" 2SiO6 .ft Specific gravity, 3.80. 

Color, black.

Among these alkali amphiboles, glaucophane and riebeckite are the 

most important. They are partly, although not absolutely, the equivalent of jadeite and acmite among the pyroxenes, but differ from them 

chemically in containing the molecules FeSi03 and MgSi03 in addition to the aluminous compounds. None of them has been prepared 

.synthetically, and, like the other amphiboles, they yield pyroxenes 

upon fusion. 6

Glaucophane occurs chiefly in a series of glaucophane schists and in 

eclogite. 6 It has also been observed in some eruptive rocks. It alters 

into chlorite, feldspar, and hematite.'1 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. 0

Arfvedsonite and barkevikite occur chiefly in augite and elseolite 

syenites, also in a granite. ^Enigmatite 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/ and so also does barkevikite.^

THE OMVINE GROUP.

Forsterite. Orthorhombic. Composition, Mg.,Si04 . Molecular 

weight, 141.4. Specific gravity, 3.2. Molecular volume, 44.2. Color, 

white, often tinted yellowish, greenish, or gray. Hardness, 6 to T.

Fayalite. Orthorhombic. Composition, FeL,SiO4 . Molecular 

Aveight, 204.4. Specific gravity, 4 to 4.14. Molecular volume, 49.8. 

Color, yellow to brown and black. Hardness, 6.5.

" See Brogger, op. cit., pp. 428-429. See also .T. Soellner, Neues Tnhrh., Bell. Bd. 24, 

p. 475, .1007, who has described a new mineral, rhoenite, allied to aenigmatite.

''See Brogger, op. cit., p. 410, with reference to nrfvedsonlte. C. Doelter (Min. pet. 

Mitth., vol. 10, p. 70, 1888) fused glaucophane with sodium fluoride and magnesium 

lluoride and obtained a product resembling acmite.

" See K. Oebbeke, Zeitschr. Deutsch. geol. Gesell., vol. 88, p. 634, 188G, for a summary 

of occurrences and bibliography. Also H. S. Washington, Am. Jour. Sci., 4th ser., vol. 11, 

p. 35, 1901 ; G. F. Becker, Mon. U. S. Geol. Survey, vol. 13, p. 102, 1888; and 1-1. Rosenbusch, Sitzungsb. Akad. Berlin, 1898, p. 706. Washington's memoir is very full. On the 

glaucophune rocks of California, see J. P. Smith, Proc. Am. Phil. Soc., vol 45, p. 183, 

1907.

d L. Colomba, Zeitschr. Kryst. Min., vol. 26, p. 215, 1896.

0 On riebeckite rocks, see G. T. Prior, Min. Mag., vol. 12, p. 92, 1889; P. Termier, Bull. 

Soc. min., vol. 27, p. 265, 1904 ; G. M. Murgoci, Am. .Tour. Sci., 4th ser., vol. 20, p. i.33, 

1905. According to Murgoci, riebeckite forms only from persilicic magmas. Riebeckite 

rocks from Oklahoma are described by A. F. Rogers in Tour. Geol., vol. 15, p. 283, 1907.

MV. C. Brogger, Zeitschr. Kryst. Min., vol. 16, pp. 407-410, 1900; also N. V. Usslug, 

idem, vol. 26, p. 104, 1896.

i Brogger, op. cit., pp. 418-422.
824 THE DATA OF GEOCHEMISTRY.

Forsterite and fayalite are two minerals which, rare by themselves, 

are very common in isomorphous mixture. The usual mixture, in 

which the magnesium salt predominates, is known as olivine, chrysolite, or peridot. A variety containing a large amount of iron is called 

hyalosiderite. Hortonolite is another member of the group, containing much iron, less magnesia, and about 4.5 per cent of manganese 

oxide. The compound Mn,SiO4 occurs as tephroite, and roepperite is 

a variety containing zinc. Knebelite is intermediate between f ayalite 

and tephroite. All of these minerals are represented by the general 

orthosilicate formula R2 SiO4 . 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.*

Monticellite. Orthohombic. 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, CaMnSiO4 , 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.6

The first intentional synthesis of olivine was effected by Berthier,0 

by simply fusing its constituent oxides together. Fouque and Levy a 

also obtained it by fusing silica and magnesia with ferrous ammonium sulphate. In their synthesis of basalt G they observed olivine 

among the earliest crystallizations from the magma. J. J. Ebelmen f 

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 ° obtained olivine by recrystallization from fused meteorites, 

magnesian eruptive rocks, and serpentine. He also h 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* fused silica and magnesia with calcium

0 See A. Damour, Bull. Soc. min., vol. 2, p 15, 1879; and L. Brugnatelli, Zeitschr. 

Kryst. Min., vol. 39, p. 209, 1904.

6 See Fouque" and Le"vy, Synthese des mine"raux et des roches, p. 96; L. Bourgeois, 

Reproduction artiflcielle des mineraiix, pp. 108-110; Vogt, Mineralbildung in Schmelzmassen, p. 8. A. Stelzner and H. Schulze (Neues Tahrb., 1882, pt. 1, p. 170) have 

described a slag containing a zinc-bearing fayalite; and H. Laspeyres (Zeitschr. Kryst. 

Min., vol. 7, p. 494, 1883) has reported another furnace product having the composition 

MnFe3Sio08.

c Cited by Fouque" and Levy, op. cit, p. 97.

<* Bull. Soc. min., vol. 4, p. 279, 1881.

 Compt. Rend., vol. 92, p. 367, 1881.

t Ann. chim. phys., 3d ser., vol. 33, p. 56, 1851.

f Compt. Rend., vol. 62, pp. 200, 369, 660, 1866.

ft fitudes synthetiques de geologic cxpcrimentale, p. 524.

* Gompt. Rend., vol. 67, p. 41, 1868.
ROCK-FORMING MINERALS. 325

chloride, and P. Hautefeuille a operated with the same oxides and 

magnesium chloride. Olivine was produced in both cases when the 

oxides were in the proper proportions. By varying the proportions 

enstatite or enstatite and olivine together were formed. S. Meunier,6 

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,0 who heated ferrous chloride with silica 

to redness in a stream of moist hydrogen. Olivine is also formed, 

according to C. Doelter,(i 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,6 

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/ 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. Penfields At Rockport, Massachusetts, fayalite has been found in 

granite.'1 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.* 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 i has described pseudomorphs of talc, serpentine, and epidote after olivine. 

The olivine was first transformed to serpentine, that into epidote, and

"Ann. chim. phys., 4th sei1 ., vol. 4, p. 120, 1865. 

. "Compt. Rend., vol. 93, p. 737, 1881. 

c Idem, vol. 98, p. 920, 1884.

" Min. pet. Mitth., vol. 10, p. 67, 1888; and Neues .Tahrh, 1897, pt. 1, p. 1. 

e Am. Jour. Sci., 4th ser., vol. 22, p. 385, 1906. 

' Idem, 3d ser., vol. 30, p. 58, 1885. 

o Idem, vol. 40, p. 75, 1890.

" See S. L. Penfleld and E. I-T. Forbes, Am. .Tour. Sci., 4th ser., vol. 1, p. 129, 1896. 

* See C. T. Clough and W. Pollard, Quart. .Tour. Oeol. Soc., vol. 55, p. 372, 1899. 

i Zeltschr. Kryst. Min., vol. 32, p. 430, 1900.
326 THE DATA OF GEOCHEMISTRY.

that finally into talc and clay. Pseudomorphs of hornblende after 

olivine are recorded by F. Becke a and B. Kolenko. 6 By a reaction 

between olivine and feldspar, according to R. Brauns," a pyroxene 

can be formed. Monticellite alters into serpentine and pyroxene; 

and C. H. Warren d 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 Al3KH2SinO24 . Fuchsite is a 

muacovite containing small amounts of chromium, replacing aluminum. Baddeckite e appears to be a muscovite containing much ferric 

iron, due to admixtures of the compound Fe3KH2Si3O12 . F. W. 

Clarke and N. H. Darton f 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.81 Sericite, margarodite, damourite, gilbertite, etc., are 

muscovites of secondary origin.

Paragonite. Monoclinic. A sodium mica, Al3NaH2 Si3O1:,, 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-bearing mica of variable composition. In most cases a mixture of a fluoriferous trisilicate, 

AlF2 .Si3 08 .R/ :i , 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 .Si3 012 .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: O is entirely trisilicate. The separate existence 

of such a compound among the micas sheds much light upon their 

constitution; but of that, more later. Zinnwaldite anol cryophyllite 

are other lithia micas containing iron and intermediate in composition between lepidolite and the ferruginous biotites. Lepidolite is

«Min. pet. Mitth., vol. 4, p. 450, 1882.

"Neues Jahrb., 1885, pt. 2, p. 90.

*Idem, 1898, pt. 2, p. 79.

d Am. Jour. Sci., 4th ser., vol. 16, p. 337, 1903.

« G. C. Hoffman, Ann. Kept. Geol. Survey Canada, vol. 9, p. 11 R, 189G.

f Bull. U. S. Geol. Survey No. 167, p. 154, 1900.

' F. W. Clarke, idem, p. 73.
BOCK-FORMING MINERALS. '

found, chiefly, if not exclusively, in albitic pegmatite veins and has 

little significance as a rock-forming mineral.

Biotite. Monoclinic. Normal composition, ALMg2KHSi3O1;i , but 

with admixtures of the corresponding ferric and ferrous salts in 

variable proportions. Molecular weight of the normal biotite, 420.3. 

Specific gravity, 2.7. Molecular volume, 155.6. The specific gravity 

of the iron biotites may reach 3.1. That is the density of siderophyllite, which is very near to the normal ferrous biotite in composition 

and has a molecular volume of 155.9. There are also biotites containing small amounts of chromium, barium, manganese, etc. Color, 

in biotite generally, green to black, rarely white, sometimes yellow 

to brown. Hardness, 2.5 to 3.

Plilogopite. Monoclinic. Composition variable; typical phlogo-. 

pite approximates to AlMg3KH2Si3 012 . 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. Betweeen 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.

Cldoritoid. Monoclinic.* 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, ALjFeHgSigOn. 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

0 Triclinic according to FJ. F. Keller and A. C. Lane, Am. .Tour. Sci., 3d sei1 ., vol. 42,- 

p. 4!)9, 189.1.
328 THE DATA OP GEOCHEMISTRY.

begun. In spite of all difficultias, 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'"8R'a(SiO4 )s and R'"3R'3 (Si3O8 ) 3 . 

Biotite, R'"2R"2R'2 (SiO4 ) 3 and R"'2R"2R'2 (Si3O8 )3. 

Phlogopite, R'"1R"3R'3 (SiO4 ) 3 and R'"1R"3R'3 (Si8O8 ) 3.

To these must be added two basic types, namely, B,/"F2 .Si3O8 .E.'3 

in lepidolite, zinnwaldite, and some phlogopites,' and the clintonite molecule R"'O2R".Si3O8 .K' 3 , with its orthosilicate equivalent 

R///O2R//.Si04 .R/3 . To each of these forms a known mica correspends, so that the expressions involve no assumptions of hypothetical molecules. In G. Tschermak's theory of the mica group,0 

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,6 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 ° 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 d obtained scales 

of white mica. This transformation is instructive, for andalusite * 

alters into muscovite quite readily. P. Hautefeuille and L. P. de 

Sairit-Gilles e fused the constituents of an iron mica with potassium 

, silicofluoride and found crystals resembling mica in their product. 

K. Chrustschoff's f work was more definite. He fused a mixture

"Zeitschr. Kryst. Min., vol. 2, p. 14, 1878; vol. 3, p. 122, 1879.

6 Berg. u. Hiittenm. Zeltung, vol. 47, p. 197. ^

K Compt Rend., vol. 113, p. 283, 1891.

d Allgem. chem. Mineralogie, p. 207.

e Compt. Rend., vol. 104, p. 508, 1887.

f Min. pet. Mitth., vol. f>, p. 55, 1887. '
ROCK-FOKMING MINEBALS. 329

equivalent to a mica basalt with the fluorides of sodium, aluminum, 

and magnesium, and also with potassium silicofluoride. After very 

slow cooling, the mass contained a micaceous mineral, which was 

separated and analyzed. It was essentially an anhydrous biotite. 

J. Morozewicz a 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,6 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 KAlSiO4 -f-MgoSiO4 , 

fused Avith 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. Finite 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.

« Ncues Tahrb., 1803, pt. 2, p. 4S.

" Idem, 1888, pt. 2, p. 178; 1897, pt. 1, p. 1. Also Min. pet. Mittli., vol. 10, p. 67, 1888.
330 THE DATA OF GEOCHEMISTRY.

' J \

It forms among the earliest secretions, immediately following the 

ores, apa.tite and zircon. It is sometimes .altered by magmatic corrosion to a mixture of augite and magnetite." Pressure seems to condition its formation. Phlogopite occurs chiefly in granular Archean limestones and in serpentine; but W. Cross 6 has described 

it as a constituent of a peculiar igneous rock, wyomingite. Chloritoid 

and ottrelite are found only in phyllitic schists,0 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 d transformed muscovite into nephelite, sodalite, 

leucite, orthoclase, and anorthite. Upon fusion, according to C. 

Doelter,6 muscovite breaks up into leucite, glass, and a substance resembling nephelite. Lepidolite and zinnwaldite behave in a similar 

manner. W. Vernadsky f 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 

Al3KH2Si3O12=AlKSi2 66+Al2SiO5+H2O;

and with this the reported derivation of muscovite from leucite can 

be correlated.*7 Biotite, according to Doelter, yields no leucite upon 

fusion, but breaks up into olivine and spinel, with other less completely identified substances. On the other hand, H. Backstrom n 

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 S 

a series of apparently indefinite substances known as " vermiculites."- 

The change, however, is very simple, and consists merely in the v 

replacement of the alkaline metals by hydrogen, with assumption of 

additional, loosely combined water. From the typical ferromag- y 

nesian micas the following derivatives are thus formed: ,

From Al2Mg2KHSi3O12 __Al2Mg2H2Si3O]2.3H2O. 

From AlMg2KH2 Si3O12 ____AlMg3H3 Si3O]2 .3H2O.

From any mixture of biotite and 'phlogopite molecules the cor- j 

responding hydrated mixture may be generated. These compounds, 

so simply related to the parent substances, form a series intermediate

0 For a discussion of this alteration, see H. S. Washington, .Tour. Geol., vol. 4, p. 257, ' 

1896.' . .

6 Am. Jour, Sci., 4th ser., vol. 4, p. 115, 1897. '

c See A. Cathrein, Min. pet. Mitth., vol. 8, 1887, p. .Sol; and L. van Werveke, Neues 

Jahrb., 1885, pt. 1, p. 227. " A

d Compt. Rend., vol. 110, p. 1170, 1890. '

e Neues Jahrb., 1897, pt. 1, p. 1. ^

f Cited by Morozewicz, Min. pet: Mitth, vol. 18, p. 20, 1898.

» See Doelter's experiment, cited above.

"Geol. Foren. Forhandl., vol.. 18, p. 162, 1890. "
. BOOK-FORMING MINERALS. 331

between the micas and the chlorites and mark a transition into the 

latter group of minerals, which will be considered next in order/'

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 hyd rated, 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,6 who assigns to them, the 

annexed empirical formulae:

Clinochlore _ _ _ - _ - _ ___ _ _ - _ .1

Penninite ___-_-_---.-- ... ____JH*(Mg,Fe) BAl 2Si3O18,

Corunclophilite ___ __- _ ___ _ __-_H=o(Fe,Mg) ]1Al 8 SiflO4B.

Daplinite ___ - _ ______ - _ _ __.HBOFe2TAl28 Si 1801 2i.

Cronstedtite ______ __ __________ .Ha (Fe,Mg) 3Fe'"2 Si2Oi3 .

Thuringite ________________ ___H]SFes (Al,Fe) 8 Si0O41 .

Stilpnomelane___ _ __ _ __ ______ ..

Strigovite__. _--_---.-___ __ _____ _ _H4 (Fe,Mn).(Fe,Al) 2SlsO,,.

Diabantite____ _ __ ____ __ __________H18 (Mg)Fe) 12Al4 Si90.)i;.

Aphrosidevite ________________ .H10 (Fe,Mg) 0Al4 Si 4O2r>. 

Delessite _ _ ___ __ ______________ _.HIO (Mg,Fe) 4Al4 Si4 0B.

Rumpflte. __ __ - .

To these may be added the* more or less uncertain minerals amesite,. 

metachlorite, klementite, chamosite, epichlorite, etc.

None of the formula) 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.0 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. 

Al,KH_(Si04 ) 8. _ ________ ________ . ____________ ____.

AUMgJKH ( SiO4 ) a. Al_Mg2Ha ( SiO4 ) 3 .3H2O. A12 ( MgOH ) 4H2 ( SiO4 ) 8 . 

AlMg3KH2 (SiO4 ) s. AlMg8Hs (SiO4 ) 3.3H2O. Al (MgOH).H8 (SiO4 ) 8 . 

AlO2Mg.Si04 .R'3 . AlO.Mg.SiO-.R'a.SH.O. AlO2Mg.SiO4 .R'3 .

"On the alteration products of the magnesinn micas, see B. Zschimmer, .Tenaische 

Zeitschr., vol. 32, p. 551, 1898. On the action of water upon, micas, A. .Tohnstone. 

Quart. .Tour. Geol. Soc., vol. 45, p. 363, 1889. For analyses of vermiculites, 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 .1. I'. 

Cooke and F. A. Genth are also important.

6 System of Mineralogy, 6th ed., p. 643.

"See G. Tschermak, Sitzungsb. Akad. Wien, vol. 99, pt. 1, p. 174, 1890; vol. 100, pt. 1, 

p. 29. R. Brauns, Neues Jahrb., 1894, pt. 1, p. 205, and Chemische Mineralogie, p. 221. 

F. W. Claj-ke,. Bull. U. S. Geol. Survey No. 125, p. 53, 1895. An earlier discussion by 

Clarke, on different lines, is given in Bull. TJ. S. Geol. Survey No. 113, p. 11, 1893.
332 . THE DATA -OF GEOCHEMISTRY.

On this basis the relations between the several series are clear and 

in accord with the natural occurrences of the minerals. In penninite 

and clinochlore we have varying mixtures of the first and second . 

chloritic types, just as among the micas we find examples intermediate between biotite and phlogopite. Prochlorite appears to be a 

derivative of the last molecule, having the formula 

A102R'.Si04.(R"OH)H2 , 

in which R" is partly Fe and partly Mg.a

It is obvious, from their hydrous character, that the chlorites can 

not form as pyrogenic minerals. They are always of secondary 

origin; and when they appear in volcanic'rocks it is as the result of 

hydrothermal alteration. Almost any aluminous ferromagnesian 

mineral may yield a chlorite in this way. Augite, hornblende, biotite, vesuvianite, epidote, tourmaline, or garnet may be the parent 

mineral.6

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. 0 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, H^Mg-^Si-jO,,, 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 d 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 _j* 

augite from the list of probabilities.

Chlorites are abundant among the metamorphic schists, chlorite 

schist being the commonest occurrence. An interesting metamorpho- i 

sis of such a rock, a pKyllite containing approximately 75 per cent of T 

muscoyjite with 25 of chlorite, is reported by K. Daintier. 6 With almost no change of composition, other than loss of water, it was trans- ^ 

formed into a mixture of andalusite and biotite.

THE MELILITE GROUP.

Melilite. Tetragonal. The composition is uncertain, but near 

Al2Ca0 Sir,019 , with Fe'" replacing some Al, and Mg or Na replacing. 

a part of the Ca. The mineral is very variable in composition. Spe0 For the other chloritic minerals see F. W. Clarke, Bull. U. S. Geol. Survey No. 125, 

pp. 53-55, 1895.

6 For a complete discussion of pseudomorphous chlorite after pyrope, see .T. Lemberg, ,t 

Zeitschr. Deutsch. geol. Gesell., vol. 27, p. 531, 1875. <

o F. W. Clarke and E. A. Schneider, Bull. U. S. Geol. Survey No. 113, pp. 27-33, 1893. ^

d Neues .Tahrti., 1897, pt. 1, p. 1.

e Idem, 1897, pt. 2, p. 156.
ROCK-FORMING MINERALS. 333

cific gravity, 2.9 to 3.1. Hardness, 5. Color, white, yellow, greenish 

yellow, brown. 

, Gehlenite. Tetragonal. The normal composition is probably 

Al2Caa Si2 010 . Corresponding molecular Aveight, 391.3. Specific 

gravity, 3. Molecular volume, 130.4. Hardness, 5.5 to 6. Color, 

grayish green to brown.

Akermannite. Tetragonal. Composition, Ca4Si3O10 , with replacements of some Ca by Mg, Fe, or Mn. Only known in slags; not as a 

separately discovered natural mineral.0

These three isomorphous silicates are closely related to one another. 

J. H. L. Vogt 6 regards gehlenite and akermannite as the two independent species, which, isomorphously commingled, form the variable melilite. This view is plausible, but is not yet 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,0 and both

have been prepared synthetically. An artificial melilite basalt was

prepared by J. Morozewicz/* and the mineral was also found by

Fouque and Levy e among the constituents of some of their synthetic

\< rocks. In Morozewicz's preparation the melilite was accompanied

'<" by augite, piagioclase, olivine, corundum, and spinel. Melilite and

^ feldspar were the last silicates to crystallize from the magma. F.

f Fouque f has shown that melilite is formed when an augite andesite

or a basalt is fused with lime, and he gives analyses of two products

-c thus obtained. G. Bodlander a found melilite in a sample of Portland

' cement; but according to Vogt h the mineral was not pure. L. Bour-

«A. L. Day and E. S. Shepherd (Am. .Tour. Sci., 4th ser., vol. 22, p. 265, 1906) find 

» that a calcium silicate of this formula can not be deposited from lime-silica fusions. 

The other bases in it are essential to its formation. Its composition can not be regarded as certainly established.

6 Mineralbildung in Schmelzmassen, pp. 96-176, 1892. See also G. Bodlander, Neues

v .Tahrb., 1898, pt. 1, p. 15 ; and F. Fouque", Bull. Soc. min., vol. 23, p. 10, 1900. Also a

more recent discussion by Vogt, Die Silikatschmelzlosungen, pt. 1, p. 49, 1903. F. Zanibonini (Zeitschr. Kryst. Min., vol. 41, p. 226, 1906) has advanced strong arguments

against Vogt's hypothesis.

c See L. Bourgeois, Reproduction artiflcielle des mine"raux, p. 123. J. H. L. Vogt, 

, Mineralbildung in Schmelzmassen, 1892. F. Fouque", Bull. Soc. min., vol. 9, p. 287, 1886. 

1'. Heberdey, Zeitschr. Kryst. Min., vol. 26, p. 19, 1896. J. S. Diller, Am. Jour. Sci., 3d 

ser., vol. 37, p. 220, 1889.

"Min. pet. Mitth., .vol. 18, p. 191, 1898. 

^ «Bull. Soc. min., vol. 2, p. 105, 1879. 

>" fldem, vol. 23, p. 10, 1900.

» Neues .Tahrb., 1892, pt. 1, p. 53. 

' h Idem, 1892, pt. 2, p. 73.
334 THE DATA OF GEOCHEMISTKY.

geois a prepared melilite by direct fusion of silica, lime, alumina, and 

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 6 found melilite 

among the fusion products of garnet and vesuvianite, and Doelter c reports it also as formed when tourmaline is fused with calcium chloride and sodium fluoride. The synthesis of gehlenite was 

effected by L. Bourgeois,** 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. Perof skite is one of. its most constant companions. Its origin 

is always pyrogenic. 0

Alterations of melilite seem to have been little studied. A. Cathrein f has described pseudomorphs of pyroxene (fassaite) and grossularite after gehlenite. By heating gehlenite with a solution of 

potassium carbonate to 200°, J. .Lemberg*' obtained calcium carbonate 

and an amorphous product having the composition of a potassium 

mica.

THE GARNETS.

Grossularite. Isometric. Composition, CagALSigOi.,. Molecular ' 

weight, 451.7. Specific gravity, 3.5. Molecular volume, 129. Color, '" 

white, yellow, brown, and sometimes pale green or rose-red. The col- ' 

oration is due to impurities.

Pyrope. Isometric. Composition, Mg3Al2Si;,012 . Molecular 

weight, 404.6. Specific gravity, 3.7. Molecular volume, 109.4. Color, 

deep red to nearly black.

Alinandite. Isometric. Composition, Ee3Al2Si3 012 . 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.

« Ann. chim. phys., 5th ser., vol. 29, p. 450, 1883.

6 Neues Jahrb., 1884, pt. 1, p. 159.

c Idem, 1897, pt. 1, p. 1.

d Ann. chim. phys., 5th ser., vol. 29, p. 448, 1883.

o For data upon melilite rocks see A. B. Tornebohm, Geol. Foren. F'drhandl., vol. 6, p. 

240, 1882. A. Stelzner, Neues Jalirb., Beil. Bd. 2, p. 369, 1883. F. D. Adams, Am. 

Jour. Sci., 3d ser., vol. 43, p. 269, 1892. C. H. Smyth, idem, vol. 46, p. 104, 1893. The 

last two references deal with American occurrences.

f Min. pet. Mitth., vol. 8, p. 400, 1887.

cZeitschr. Deutsch. geol. Gesell., 1892, p. 237.
KOCK-FOEMING MINERALS. 335

Spessartite. Isometric. Corilposition, Mn3Al2Si3O12. Molecular 

weight, 496.4. Specific gravity, 4.2. Molecular volume, 118. Color, 

red to brown.

Andradite, melanite, or common garnet. Isometric. Composition, 

Ca,,Fe'" 2Si3O12. Molecular weight, 509.3. Specific gravity, 3.85. 

Molecular volume, 158.2. Color, green, yellow, brown, or black.

Uvarovite. Isometric. Composition, Ca3Cr2Si3 012 . Molecular 

weight, 501.7. Specific gravity, 3.5. Molecular volume, 143. Color, 

emerald-green.

The foregoing six species, with their many isomorphous mixtures, 

form the important garnet group. With them may be included the 

rare mineral schorlomite, which contains titanium partly replacing 

silicon and ferric iron. Its formula is Ca3 (Fe,Ti''0 2 (SiTilv )Arrt 

The sodium garnet lagoriolite, Na6Al2Si3 012 , which was obtained 

by J. Morozewicz 6 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.0

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,fZ 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 c obtained 

biotite, anorthite, meionite, olivine, and magnetite. L. Bourgeois/ 

from the fusion of a mixture equivalent to grossularite, obtained 

N- anorthite and monticellite; and J. H. L. Vogt^ reports anorthite as 

formed under similar conditions. When magnesia, oxide of manganese, or iron oxide was added to Vogt's mixture, melilite was also 

J produced. The syntheses of garnet reported by several early investi- 

' gators h are of doubtful authenticity.

Bourgeois, however, in the research just cited, prepared spessartite 

v- by fusing together its constituent oxides in the proper proportions.

0 R. Soltmann (Zeitschr. Kryst. Min., vol. 18, p. 628, 1891) has described a raelanite 

garnet containing 11.01 per cent of Ti02, which should probably be partly reduced to

., TlaOa.

"Min. pet. Mitth., vol. 18, p. 147/1898.

c For systematic papers on the garnet group see W. C. Brb'gger and H. Btickstrom, 

Zeitschr. Kryst. Min., vol. 18, p. 209, 1891; and E. Weinschenk, idem, vol. 25, p. 365, 

1896. 

\- d Neues .Tahrb., 1884, pt. 1, p. 158.

«Idem, 1897, pt. 1, p. 1.

' 'Ann. chim. phys., 5th ser., vol. 29, p. 458, .1.883. 

" Mineralbildung im Schraelzmassen, p. 187, 1892. 

71 See Fouque" and Ldvy, Synthese des mine'raux et des roches, p. 122.
836 THE DATA OF GEOCHEMISTBY.

A. Gorgeu a also obtained spessartite "when pipe clay was fused with 

an excess of manganese chloride. A similar fusion with calcium 

chloride gave, with other products, crystals which were possibly 

grossularite. Fouque and Levy 6 report melanite as formed when 

nephelite and pyroxene are fused together. L. Michel c 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 eruptives, especially in leucite and 

nephelite rocks. It is also found in serpentines, in iron ore beds, and 

as a product of contact action, associated with wollastonite and . 

pyroxene, in certain volcanic rocks. Pyrope is often found in peridotites and the serpentines derived from them. Spessartite occurs in 

granite, quartzite, and some schists. W. Cross d 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,c ... 

describing the rocks of a single region, reports pseudomorphs after 

garnet of scapolite, epidote, oligoclase, hornblende, saussurite, and \r 

chlorite. Chloritic pseudomorphs are perhaps the most frequent/ > 

The. pyrope found in peridotite rocks is often surrounded by a zone v 

or shell of altered material, to which A. Schrauf*7 has given the 

name kelyphite. It is, however, not a substance of uniform com- I 

position. The kelyphite studied by A. von Lasaulx ll was mainly 

a mixture of pyroxenes and amphiboles. J. Mrha * described a 

kelyphite consisting of bronzite, monoclinic pyroxene, picotite, and / 

hornblende. The pyrope from the peridotite dikes of Elliott

a Ann. chim. phys., 6th ser., vol. 4, pp. 536, 553, 1885.

"Compt. Rend., vol. 87, p. 962, 1878. ;

o Idem, vol. 115, p. 830, 1892. 0

& Am. Jour. Sci., 3d ser., vol. 31, p. 432, 1886.

 Zeitschr. Kryst. Mln., vol. 10, p. 433, 1885.

f See for example J. Lemberg, Zeitschr. Deutsch. geol. Gesell., vol. 27, p. 531, 1875 ; t 

and S. L. Penfleld and F. L. Sperry, Am. Jour. Sci., 3d ser., vol. 32, p. 307, 1886. f> 

» Zeitschr. Kryst. Min., vol. 6, p. 358, 1882. 

"Verhandl. Naturhist. Ver. preuss. Rheinland u. Westfalen, vol. 39, pt. 2, p. 114, 1882. (

* Min. pet. Mitth., vol. 19, p. Ill, 1899.
ROCK-FORMING MINERALS. . .337

County, Kentucky, described by J. S. -Diller,0 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 v as an alteration product 

\ of other minerals. P. Jeremeef 6 has recorded, pseudomorphs of 

grossularite after vesuvianite; and grossularite after gehlenite was 

observed by A. Cathrein. 0

VESTJVIANITE.

Tetragonal. Composition variable, and best, represented by the 

general formula ALCa^^O.^!^; in which R' 4 may be Ca2 , 

(A10H),, (A102H2 ) 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 

6xide.d 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 jproduct 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.e When vesuvianite is fused, it breaks up into 

meionite, melilite, anorthite, and possibly a lime olivine.'

THE SCAPOLITES.

Meionite. Tetragonal. Composition, Ca4Al0Si0O2 r,. Molecular 

weight, 893.4. Specific gravity, 2.72. Molecular volume, 328.4. 

Colorless or white. Hardness, 5.5 to 6.

Marialite. Tetragonal. Composition, Na4Al3Sin (X4Cl. Molecular 

Aveight, 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.*7 Intermediate between them, and analogous to the plagioclase feldspars lying between

« Bull. U. S. Geol. Survey No. 38, 1887.

» Zeitschr. Kryst. Min., vol 31, p. 505, 1899.

» Min. pet. Mitth., vol. 8, p. 400, 1887.

'"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. Cheinie, vol. 8, p. 356, 1895; M. Weibull, Zeitschr. Kryst. Min.,'vol. 25, p. 1, 1895; A. 

Kenngott, Neues Jahrb., 1891, pt. 1, p. 200; EL Sjogren, Geol. Foren. Forhandl., vol. 17, p. 

267, 1895.

«Zeitschr. Kryst. Min., vol. 31, p. 505, 1899.

t C. Doelter and B. Hussak, Neues Jahrb., 1884, pt. 1, p. 158.

v Min. pet. Mitth., vol. 7, p. 400, 1886 ; Monatsh. Chemie, 'vol. 4, p. -851, 1883. Compare F. W. Clarke's constitutional formulae in Bull. TJ. S. Geol. Survey No. 1.25, 1895.

14399 Bul 1.330 OS 22
338 THE DATA OF GEOCHEMISTRY.

anorthite and albite, are the following scapolites, which have received 

independent names:

Wernerite ____ _______________ ____ Me3Ma! 

Mizzonite or dipyre _________________ MejMa2 to MetMa3

The reported syntheses of scapolite are not altogether conclusive. 

L. Bourgeois a attempted to prepare meionite by. fusing together its 

constituent oxides, and obtained principally anorthite. By adding 

fragments of marble to a molten basaltic glass, however, he observed 

in one case the formation of crystals which were probably meionite. 

By fusing a leucitite with the fluorides of sodium and calcium, K. B. 

Schmutz & 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 c 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, CaAl2 Si 2 08 , 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/' 

In Norway scapolite rocks are associated with masses of apatite, 

especially at Oedegaarden. In this instance J. W. Judd e 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/ however, regards the change as due to contact 

action between the rock and the apatite, although in other localities 

solutions of chlorides appear to be operative. Mechanical agencies 

are considered by Lacroix to be unimportant. At the Oedegaarden 

locality, which has been studied by several authorities, a granitic 

mixture of pyroxene and feldspar has been transformed into an 

aggregate of hornblende and scapolite. By fusion Fouque and 

Levy g transformed it back again into pyroxene and labradorite. A 

Canadian scapolite diorite has been described by F. D. Adams and

"Ann. chim. phys., 5th ser., vol. 29, pp. 446, 472, 1883.

6 Neues Jahrb., 1897, pt. 2, pp. 133, 149. - 

. c Idem, pt. 1, p. 1. .

d See F. Zirkel, Lehrbuch der Petrographie, vol. 1, p. 382, 1893. W. Salomon, Min. pet. 

Mitth., vol. 15,. p. 159, 1895, gives a good bibliography relative to dipyre.

« Mineralog. Mag., vol. 8, p. 186, 1889.

'Bull. Soc. min., vol. 14, p. 16, 1891. In vol. 12, p. 83, 1889, Lacroix has an elaborate monograph upon scapolite rocks.

' Bull. Soc. min., vol. 2, p. 112, 1879.
BOCK-FOEMING MINEEALS; 339

A. C. Lawson,*1 and H. Lenk b has studied an augite-scapolite rock 

from Mexico.

The scapolites are exceedingly alterable, and most so toward the 

sodium or marialite end of the series. Many of the alteration products have been regarded as distinct species and have received independent names. Pseudomorphs of mica, often in the form of 

" pinite," after scapolite are very common. Alterations into epidote, 

steatite, kaolin, and free silica are also recorded. A. Cathrein c has 

reported pseudomorphs of scapolite after garnet.

 IOLITE.

Iolite or cordierite. Orthorhombic. H2 (Mg,Fe) 4Al8Si10037 .(i 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 T.5.

A possible synthesis of iolite was reported by L. Bourgeois, 17 who 

fused silica, magnesia, and alumina together in proper proportions. 

J. Morozewicz f also obtained it in his experiments upon artificial 

magmas, supersaturated with alumina, of the general formula 

RO.mAl2 0.j.^Si02 . When magnesia and iron were present and n 

Avas greater than 6, iolite was formed. In short, he produced an artificial cordierite-vitrophyrite, resembling the African rock described 

b}'- G. A. F. Molengraaf.0 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 variet}7 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.'1 In order 

of deposition it follows biotite, but precedes the feldspars. In cordierite gneiss and cordierite hornfels iolite is a characteristic .constituent. The gneiss from Connecticut described by E. O. Hbvey i 

consisted mainly of biotite, quartz, and iolite, with some plagioclase.

« Canadian Rec. Scl., vol. 3, p. 186, 1888.

» Neues Jahrb., 1899, pt. 1, ref. 73.

< Zeltschr. Kryst. Min., voh 9, p. 378, 1884 ; vol. 10, p. 434, 1885. 

'' Formula based upon 0. C. Farrington's analysis, Am. .Tour. Sci., 3d ser., vol. 43, 

p. 13, 1892. M. Weibull (Geol. Foren. Forhandl., vol. 22, p. 33, 1900) regards the mineral as anhydrous, and writes the formula MgoAMAlOhSisOio.

« Ann. chim. phys., 5th ser., vol. 29, p. 462, 1883.

f Min. pet. Mitth., vol. 18, pp. 68, 167, 1898. See ante, p. 276, under " Corundum."

" Neues Jahrb., 1894, pt. 1, p. 79.

'' See H. Biicklng, Ber. Senckenbergischen naturforsch. Gesell., 1900, Abhandl., p. 3; 

J. Szab6, Neues Jahrb., Beil. Bd. 1, p. 308, 1881; E. Hussak, Sitzungsb. Akad. Wien, vol. 

87, pt. 1, p. 332, 1883 ; Neues Jahrb., 1885, pt. 2, p. 81; A. Harker, Geol. Mag., 1906, 

p. .176.

1 Am. Jour. Scl., 3d ser., vol. 36, p. 57, 1888.
340 THE DATA OF GEOCHEMISTBY.

lolite is also well known as a product of contact metamorphism. For 

example, Bucking a found it in sandstones which had been .vitrified 

by contact with basalt; and Kikuchi 7' has described .a Japanese 

locality where iolite occurs in slate at contact with granite.

lolite alters with great ease, taking up water and alkalies. The 

product is usually an impure mica, and many pseudomorphs of this 

character have received distinctive names. Chlorophyllite, praseolite, 

aspasiolite, gigantolite, fahlunite, pinite, etc., are merely altered 

iolite.0

THE ZOISITE GROUP.

Zoisite. Orthorhombic/z Composition, HCa2Al3Si3O1?,. Molecular Aveight, 455.9 Specific gravity, 3.25 to 3.37. Molecular volume, 

138. Color, white, gray, greenish, yellowish, reddish. Hardness, 6 

to 6.5.

Epidote. Morioclinic. 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 c claimed to 

have produced zoisite by fusing 40 parts of silica with 37 of lime 

and 23 of alumina. C. Doelter/ 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, de0 Loc. cit.

"Jour. Coll. Sci., Japan, vol. 3, p. 313, 1890. Kikuchi also describes an alteration of 

the iolite into pinite.

c For a summary of these alterations see A. Wichmann, Zeitschr. Deutsch. geol. Gesell., 

vol. 26, p. 675, 1874. For the mechanism of the change from iolite to Chlorophyllite, see 

F. W. Clarke, Bull. U. S. Geol. Survey No. 125, p. 83, 1895.

rt For optical variations in zoisite, see P. Termier, Bull. Soc. rain., vol. 21, p. 148, 1898 ; 

vol. 23, p. 50, 1900. Termier regards the silicate HCa2R'"3SiaOj3 as trimorphous.

8 Arch. sci. phys. .nat., 3d ser., vol. 25, p. 239, 1891.

t Neues Jahrb., 1897, pt. 1, p. 1,
BOCK-FOKMING MINEEALS. 341

rived from plagioclase and commonly containing both minerals commingled, is known as saussurite and is common in. gabbros.* It is 

not at all uniform in composition.0

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 

and was also observed inclosed in primary sphene. A. Michel Levy ° 

also regards the epidote of certain Pyrenean ophites as primary. 

Epidote is common in gneisses, garnet rock, amphibplite, 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.<*

Piedmontite is much less abundant than zoisite or epidote' and 

is mainly confined to the crystalline schists. It also occurs Avith 

iron ores, and as a secondary mineral in eruptives. G. H. Williams ° 

has reported piedmontite in a rhyolite from Pennsylvania and N. 

Yamasaki f has described a similar occurrence in Japan. Piedmontite 

is quite common in the crystalline schists of Japan/ 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,71 who have pointed out its importance, cite occurrences of allanite in gneiss, granite, quartz porphyry, diorite, andesite, dacite, rhyolite, etc. W. H. Hobbs,i: 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/ A. Lacroix,fc G. H. Williams/ and others. In the

"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.

*Bull. Geol. Soc. America, vol. 4, p. 305, 1898.

c Bull. Soc. gfiol., 3d ser., vol. 6, p. 161.

"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.

o Am. Jour. Sci., 3d ser., vol. 46, p. 50, 1893. This paper contains many references to 

literature.

f Jour. Coll. Sci., Japan, vol. 9, p. 117, 1897.

o See B: Koto, idem, vol. 1, p. 303, 1887.

* Am. Jour. Sci., 3d ser., vol. 30, p. 108, 1885.

1 Idem, vol.. 38, p. 223, 1889.

i Canadian Rec. Sci., vol. 4, p. 344, 1891.

*Bull. Soc. min., vol. 12, pp. 138, 157, 210, 1889. 

' Bull. U. S. Geol. Survey No. 62, 1890.
342 THE DATA OF GEOCHEMISTRY.

granite of Pont Paul, France, allanite is sometimes enveloped by 

biotite.* Allanite is often much altered, yielding- carbonates of the 

cerium group, together with earthy products of uncertain character.

TOPAZ.

Orthorhombic. Simplest empirical formula, Al2Si04F2 , but with 

part of the fluorine commonly replaced by hydroxyl. 6 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. 0 .

The synthesis of a product allied to topaz was early reported by 

A. Daubree,'1 who heated alumina in a current of silicon fluori.de. It' 

contained, however, too little fluorine, and varied in other respects 

from topaz. H. Sainte-Claire Deville,0 repeating the experiment, 

obtained no fluoriferous silicate. C. Friedel and E. Sarasin f claim to 

have prepared topaz by heating alumina, silica, Avater, and hydrofluosilicic acid together at 500°, but give no details nor analyses. A. 

Reich o 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 

w'as 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 ll as a porphyritic 

topazfels. The Brazilian topazes are found in decomposed material, 

which, according to 0. A. Derby/ was probably a mica schist derived 

from an antecedent augite or nepheline syenite. In Colorado and 

Utah topaz occurs in lithophyses of rhyolite.'? 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.7- 

The reported alterations to steatite and serpentine are probably 

based upon erroneous diagnoses. By heating topaz with a solution

a A. Michel L§vy and A. Lacroix, Bull. Soc. min., vol. 11, p. 65, 1888.

6 S. L. Penfield and J. C. Minor, Am. Jour. Scl.', 3d ser., vol. 47, p. 387, 1894.'

c See F. W. Clarke and J. S. Diller, Bull. U. S. Geol. Survey No. 27, 1886, and also 

Clarke, Bull. No. 125, 1895.

<* fitudes synthe'tiques de ge~ologie expe~rimentale, p. 57.

<> Compt. Rend., vol. 52, p. 780, 1861.

f Bull. Soc. min., vol. 10, p. 169, 1887.

' Monatsh. Chemie, vol. 17, p. 149, 1896.

ft Zeitschr. Deutsch. geol. Gesell., vol. 36, p. 642, 1884.

{ Am. Jour. Sci., 4th ser., vol. 11, p. 25, 1901.

l See W. Cross, idem, 3d ser., vol. 31, p. 432, 1886.

fc 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, p. 402, 

1874-75.
ROCK-FORMIKG MINERALS. ' 34$

of sodium silicate 174 'hours at 200° to 210°, J. Lemberg* converted 

it into an alkaline alumo-silicate of presumably zeolitic character. 

At a white heat topaz loses fluorine and becomes transformed into 

sillimanite.6 " .

THE ANDALTJSITE GROUP.

Andalusite. Orthorhombic. Simplest empirical formula, Al2Si05 ; 

true formula probably three times as great. Corresponding molecular weight, 162.6. Specific gravity, 3.18. Molecular volume, 51.1. 

Color, white, reddish, violet, brown, olive-green. Hardness, 7.5.

Sillimanite or fibrolite. Orthorhombic. Composition and lowest 

molecular weight the same as for andalusite. Specific gravity, 3.2. 

Molecnl r volume, 50.8. Color, grayish white, grayish brown, pale 

green, brown. Hardness, 6 to 7.

Kyanite or cyanite. Triclinic. Composition etc., as with andalusite and sillimanite. Specific gravity, 3.6. Molecular volume, 45.2. 

Color, commonly blue, sometimes white, gray, or green. Hardness, 7.

These three minerals are of peculiar interest because of their identity in chemical composition. They undoubtedly differ in chemical 

structure, and kyanite possibly differs from the other two in molecular weight, but upon the latter point the evidence is not conclusive. 

Andalusite and sillimanite are commonly regarded as basic orthosilicates, and- kyanite, on account of its greater resistance to the 

action of acids, has been interpreted by P. Groth as a metasilicate, 

(AlO) 2SiO3 . c In an interesting investigation by W. Vernadsky (Z 

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 jJ«ee species, 

at least under pyrogenic conditions. Vernadsky has idSitified it as 

an essential constituent of hard porcelain. He also obtained silli-. 

manite bj "fusing silica and alumina together. More recently A. 

Reich,6 by heating aluminum fluoride with silica to strong redness, 

obtained a mixture of sillimanite and corundum. The conditions 

under whicn sillimanite can form magmatically have also been determined by J. Morozewicz.f In the magmatic mixture E,O.mAl2 0;v 

, if magnesia and iron are absent, m=l, and n is greater than

" Zeitschr. Deutsch. geol. Gesell., vol. 40, pp. 651 et seq., 1888.

» W. Vernadsky, Bull. Soc. min., vol. 13, pp. 259-260, 1890.

" A different but not very plausible interpretation of these species has been offered by 

K. Zulkowski, Monatsh. Cheinie., vol. 21, p. 10S6, 1900.

"Bull. Soc. min., vol. 13, p. 256, 1890; Cotupt. Rend., vol. 110, p. 1377, 1890. For 

earlier syntheses of these minerals, by Daubrfie, Deville and Caron, Fremy and Fell. 

Meunier, and Hautefeuille and Margottet, see L. Bourgeois, Reproduction artificielle des 

min.<5raux, pp. 119, 120. The processes, except in the last instance, Involved the use of 

aluminum fluoride, silicon fluoride, or silicon chloride, and were therefore indirect. 

' » Monatsh. Chemie, vol. 17,- p. 149, 1896.

f Min. pet. Mitth., vol. 18, p. 72, 1898.
344 THE DATA OF GEOCHEMISTRY.

/

6, sillimanite is developed. K. Dalmer ° has reported the alteration 

of a chlorite-mica phyllite into a mixture of andalusite and biotite.

Andalusite is a mineral of the metamorphic schists, and is especially common in the contact zones of clay slate near dikes of granite 

or diorite. It is also found in Archean gneiss and mica schist, and 

sometimes as an accessory in granite.

Sillimanite is common in the crystalline schists, particularly in 

feldspathic gneiss, and in cordierite gneiss. It is often found intergrown with quartz.

Kyanite also occurs in crystalline schists, such as gneiss, mica 

schist, paragonite schist, and eclogite. It is often embedded in 

quartz, and has been reported in limestone. 6

Andalusite alters to muscovite," and sometimes also to chlorite and 

kaolin.* J. Lemberg,6 by heating andalusite or kyanite with alkaline 

silicates or carbonates, under pressure, converted' them into zeolitic 

substances. C. Doelter/ 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 (SiOJ 3 (AlO) 3.

Topaz__________________-----___.. Al3 (SiO4 ) 3 (AlF,) 3 . 

Muscovite_______-__-_____________ Al3 (SiO4 ) 3KH2.

STATJROMTE.

Orthorhombic. Composition, HFeAl5Si2 013 ,ff with a little magnesia or sometimes manganese oxide replacing a part of the iron. 

Molecular weight, 4'57.2. 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/1 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.* P. -Hautefeuille and J. MargotteV in their memoir

°Neues Jahrb., 1897, pfr. 2, p. 156. ' 

6 ,T. Kovar, Zeitschr. Kryst. Min., vol. 34, p. 704, 1901. 

c A. Gramann, Neues Jahrb., 1901, pt. 2, p. 193. 

d P. E. Haefele, Zeitschr. Kryst. Min., vol. 23, p. 551, 1894. 

0 Zeitschr. Deutsch. geol. Gesell., vol. 40, p. 651, 1888. 

t Allgem. chem. Mineralogie, p. 207.

"Established by S. L. Penfield and J. H. Pratt, Am.-.Tour. Sci., 3d ser., vol. 47, p. 81, 

1894.

""Compt. Rend., vol. 46, p. 764, 1858. . - 

1 I-I. Sainte-Claire Deville, Idem, vol. 52,-p. 780, 1861. 

'Idem, vol. 96, p. 1052, 1883. ~ ' "
ROCK-FORMING MINERALS. 345

upon the synthesis of certain phosphates, also mention the produc1011 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.* The

reported alteration into steatite is very questionable.

[LAWSONITE.

Orthorhombic. Composition, H4CaAl2 Si.J010. 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 b- in 1895, in a glaucophane-bearing schist from Tiburon Peninsula, California. It has 

since been found by S. Franchi and A. Stella ° in the metamprphic 

schists of the Alps; by C. Viola (l in the saussuritized gabbros of 

southern Italy; and by A. Lacroix e in similar rocks and glaucophane schists from Corsica and New Caledonia. J. P. Smith f has 

recently described lawsonite rocks from several localities in California, especially a laAvsonite-glaucophane schist and a lawsoniteglaucophane gneiss. . The latter rock carried about. 25 per cent of 

lawsonite. The mineral is evidently j>f 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,5' the compound H4CaAl2Si2 09 is dimorphous. Lawsonite is one modification; the other, isometric, he has 

named hibschite. It was found enveloping garnet as an inclusion 

in the phonolite of Aussig, Bohemia.

DUMORTIERITE.

Orthorhombic. Composition, Al8HBSi3O20.'1 Molecular weight, 

634. Specific gravity, 3.3. Molecular volume, 192. Color, blue, 

bluish green, lavender, or black. Hardness, 7.

0 See analysis in 'Bull. U. S. Geol. Survey No. 220, p. 54, 1903.

6 Bull. Dept. Geology Univ. California, vol. 1, p. 301, 1895. See also F. L. Ransome 

and C. Palache, Zeitschr. Kryst. Min., vol. 25, 1896, p. 531 ; and W. T. Schaller and 

W. P. I-Iillebrand, Bull. U. S. Geol. Survey No. 262, p. 58, 1905.

° Cited by P. Termier, Bull. Soc. mln., vol. 20, p. 5, 1897. See also Termier, idem, vol. 

27, p. 265, 1904.

" Zeitschr. Kryst. Min., vol. 28, p. 553, 1897.

" Bull. Soc. min., vol. 20, p. 309, 1897.

' Proc. Am. Phil. Soc., vol. 45, p. 183, 1907. See also A. S. Eakle, Bull. Dept. Geology 

Univ. California, vol. 5, p. 82, 1907.

» Min. pet. Mitth., vol. 25, p. 249, 1906.

* As determined by W. T. Schaller, Bull. U. S. Geol. Survey No. 262, pp. 91-120, 1905. 

See also W. E. Ford, Am. Jour. Sci., 4th ser., vol. 4, p. 426, 1902. Ford's formula differs slightly from Schaller's.
346 . THE DATA OF GEOCHEMISTRY.

Dumortierite was originally discovered in a pegmatite gneiss near* 

Lyons, in France. It has since been found in Germany, Austria, 

Norway, Argentina, and at several localities in the United States.0 

It has been observed in pegmatite, in cordierite gneiss,6 in granite, 

anc1 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 

to W. Vernadsky,0 dumortierite, at a white heat, is converted into 

sillimanite. What other product is formed at the same time is not 

stated/*

TOTTBMALINE.

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-biptite.

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. 6 The following formulas seem to be best sustained by evidence -J

a See Schaller's memoir, cited above, for a full summary of the known localities and a 

bibliography of the species.

6 See A. Lacroix, Bull. Soc. min., vol. 12, p. 211, 1889.

"Bull. Soc. min., vol. 13,-p. 256, 1890.

* G. I. Finlay (Jour. Geol., vol. 15, p. 479, 1907) reports dumortierite and corundum 

as original pyrogenic constituents of a pegmatite dike near Canyon, Colorado.

» See C. Rammelsberg, Neues Jahrb., 1890, pt. 2, p. 149. A. Kenngott, idem, 1892, 

pt. 2, p. 44. G. Tschermak, Min. pet. Mitth., vol. 19, p. 155, 1899; Zeitschr. Kryst. Min., 

vol. 35, p. 206, 1899. V. Goldschmidt, Zeitschr. Kryst. Min., vol. 17, pp. 52, 61, 1890. 

R. Scharizer," idem, vol. 15, p. 337, 1889. P. .Tannasch and G. Calb, Ber. Deutsch. chemi 

Gesell., vol. 22, p. 216, 1889. H. Rheineck, Zeitschr. Kryst. Min., vol. 17, p. 604, 1890; 

vol. 22, p. 52, 1894. E. A. Wiilflng, Min. pet. Mitth., vol. 10, p. 161, 1888.

r Bull. U. S. Geol. Survey No. 167, p. 26, 1900; Am. Jour. Sci., 4th ser., vol. 8, p. Ill, 

1899. Also in Bull. U. S. Geol. Survey No. 125, 1895.
BOCK-FOBMING MINERALS. 347

(1) Al8R'B SieB8 081 . -^

(2) Al7R' 8SieB8 081 .

(3) AlB R' 14Si,B8 081 ..

In No. 3 the B' 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/,) (BOH) 2 Si4O10 , proposed by S. L. Penfield and H. W. Foote," 

is preferred by some authorities.

Tourmaline has not as yet been produced synthetically. The rockforming iron-bearing variety is commonly found in the older and more 

highly siliceous igneous and granular rocks, such as granite, syenite, 

and diorite. It is also abundant in mica schists, clay slates, and 

other similar matrices. It forms in some cases at the contact between 

schists and granite, and may be abundant enough to characterize an 

occurrence as a tourmaline hornstone. In igneous rocks it seems to 

have been produced by f umarole action, and not as a direct separation 

from the magma. H. B. Patton & 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,0 tourmaline yields olivine and spinel.

BEKYI*.

Hexagonal. Normal composition, Al2Gl3Si0 018 . 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 a has shown that many 

beryls contain alkalies, replacing glucina, and also some combined 

\vater, up to nearly 3 per cent. A beryl from Hebron, Maine, contained 3.60 per cent of Cs2 0. A beryl analyzed by J. S. De Benne- 

,ville c carried 2.76 per cent of K2O; and F. C. Robinson/ in another 

example, found 2.76 per cent of P2 05 .

J. J. Ebelmen ° succeeded in recrystallizing beryl by fusion with 

boric oxide. P. Hautefeuille and A. Perrey n obtained it in crystals 

by fusing a mixture of alumina, glucina, and silica with the same 

flux. H. Traube i precipitated a solution containing aluminum sula Am. Jour. Sci., 4th ser., vol. 7, p. 97, 1899; vol. 10, p. 1Q, 1900. 

"Bull. Geol. Soc. America, vol. 10, p..21, 1898. 

c Neues Jahrb., 1897, pt. 1, p. 1.

" Am. Jour. .Sci., 3d ser., vol. 28, p. 25, 1884 ; vol. 36, p. 317, 1888. 

" Jour. Am. Chem. Soc., vol. 16, p. 65, 1894. 

f Jour. Anal, and Appl. Chem., vol. 6, p. 510, 1892. 

a Ann. chim. phys.,' 3d ser., vol. 22, p. 237, 1848. 

- "Compt. Rend., vol. 106, p. 1800, 1888. 

* Neues Jahrb., 1894, pt. 1, p. 275.
348 THE DATA OF GEOCHEMISTRY.

phate 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 founc( 

in clay slate and mica schist. It alters into mica and kaolin, when 

the removed glucina generally appears as a constituent of other 

secondary minerals, such as bertrandite, herderite, or beryllonite. 

Although beryl is not commonly included by petrographers in their 

lists of rock-forming minerals, it seems entitled to recognition in a 

chapter of this kind.

SERPENTINE, TALC, AND KAOMNITE.

Serpentine. Optically monoclinic, but not known in true crystals. . Composition, H^MgjSioOy. 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 1 

reactions, but these syntheses have little or no significance in the 

interpretation of serpentine.0 The mineral occurs in nature only, as 

a secondary product, derive'd 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,6 peridotite,c and amphibolite d may undergo this change. 6 The. alterative 

process, however, does not end here. Serpentine itself may undergo 

further alteration, yielding brucite, magnesite, hydromagnesite, etc. 

R. Brauns t has described a derivative of serpentine, which he calls

webskyite, H0Mg4Si3O1;..6H2O; and F. W. Clarke^ 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.71 When serpentine is fused it yields a mixture of olivine and enstatite^

a See for example, A. Gages, Kept. Brit. Assoc., 1863, p. 203. Gages's product resembled 

deweylite.

6 See L. Finckh, Zeitschr. Deutsch. geol. Gesell., vol. 50, p. 108, 1898.

c See G. H. Williams, Am. Jour. Sci., 3d ser., vol. 34, p. 137, 1887.

d See J. B. Jaquet, Rec. Geol. Survey, 'New South Wales, vol. 5, p. 18, 1905.

6 For general discussion over the origin of serpentine, see G. F. Becker, Mon. U. S. Geol. 

Survey, vol. 13, pp. 108 'et seq., 1888; .and J. J. H. Teall, British Petrography. The literature is very abundant.

f Neues Jahrb., Beil. Bd. 5, p. 318, 1887, Brauns discusses the different varieties of serpentine fully, and cites much literature.

o Bull. U. S. Geol. Survey No. 262, p. 69, 1905.

" See G. F. Becker, Mon. U. S. Geol. Survey, vol. 13, pp. 108 et seq., 1888; also A. 

Lacroix, Compt. Rend., vol. 124, p. 513, 1897.

* Daubree; see ante, p. 312, under enstatite.
BOCK-FORMING MINERALS. 349

. Talc. Monoclinic. Composition, H2Mg3 Si4O12 . 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." Assuming the 

change to be brought about by carbonated water, the reactions may 

be simply written as follows: . CaMg8Si4O1 ,+H,0+CO,=H,Mg,Si4O1 ,+CaCO8 . , 

Mg4 Si4O12+H2 0+CO2 -H2Mgf! Si4 0]2+MgCO;i .

The talc thus produced is not infrequently associated with marble 

or dolomite. The most important occurrence of talc, however, from 

a geological point of view, is in the form of talcose schist.

According to F. A. Genth, talc may alter into anthophyllite.6 

When talc is ignited, it loses water, and one-fourth of the silica is 

split off in the free state. 0 The residue, after removing the liberated 

silica, has the composition MgSiOs.

A number of other hydrous magnesian silicates occur as secondary 

minerals, such as deweylite, saponite, etc.; but they are geologically 

unimportant.

Kaolinite. Monoclinic. Composition, H4Al.,Si2 0!) .. 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, whicli has already ;been 

described. The more important zeolites are the. following:

Heulanclite________________._1^_. CaAl2 Si00,0.5H2O. 

Stilbite________________________. CaALSi0O10.6H2O.

Laumontite___________ _____-_____ CaAl 2 Si4O, a .4H2O. 

Chabazite________________________. CaAl2 8i4Oia .6H3O.

Thornsonite________________.______ CaAl2 Si 2Os.2£H2 0. 

Scolecite_________________..__________ .CftAl_SI3OI0.3HsO.

Natrolite_______________________ Na«Al 2 SisOi02PI_O.

Hydronephelite ± - _ HNa2A]3Si.,Ol2 .3H2Q.

0 See C. H. Smyth, School of Mines Quart., vol. 17, p. 333, 1.800, and T. H. Pratt, North 

Carolina Geol. Survey, Economic Paper No. 3. 

"Proc. Am. Phil. Soc., vol. 20, p. 381, 1882. 

C F. W. Clarke and E. A.. Schneider, Bull. TJ. S. Geol. Survey No. 78, p. 13. 1801.
.350 THE DATA OF GEOCHEMISTRY.

To these may be added ptilolite, mordenite, brewsterite, epistilbite, 

phillipsite, gismondite, laubanite, gmelinite, levynite, faujasite, 

edingtonite, mesolite, erionite, wellsite, and perhaps other species. 

As a rule, in the lime-bearing zeolites, a part of the lime may be replaced by other bases, generally by soda. Potassium, however, is 

found in notable quantities in phillipsite, harmotome, edingtonite, 

and wellsite; and strontium in brewsterite and wellsite. The formula 

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 a are other secondary minerals whose mode of occurrence is like that of the true 

zeolites; and possibly the species prehnite and datolite should on* 

genetic grounds be grouped with them. Mineralogically these minerals are classed elsewhere; it is only as regards their mode of formation that they are mentioned now.

Many syntheses of zeolites and zeolitic compounds are recorded, 

and several species have been recrystallized from solution in superheated waters. The syntheses Avere necessarily effected by hydrochemical reactions, either operating upon such minerals as anorthite 

or nephelite, or by double decomposition 'between aqueous solutions. 

PI. Sainte-Claire Deville,6 for example, produced phillipsite, levynite, and gmelinite by heating solutions of 'potassium silicate with' 

sodium or potassium aluminate to 170°. " C. Doelter c prepared apophyllite, okenite, chabazite, heulandite, stilbite, laumontite, thomsonite, 

natrolite, and scolecite by various processes; and J. Lemberg* 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%ave already been described. 6 At 

the hot springs of Plombieres A. Daubree f 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 in France and 

Algeria.*'

0 On apophyllite as a rock-forming mineral, see F. Cornu, Centralbl. Min. Geol. Pal., 

1907, P. 239.

"Cornpt. Rend., vol. 54, p. 324, 18G2.

c Neues Jahrb., 1890, pt. 1, p. 118.

a Zeitschr. Deutsch. geol. Gesell., vol. 28, p. 519, 1876.

0 See ante, p. 305.

f fitudes synthe"tiques de ge"ologie expe"rimentale, p. 179.

" Idem, p. 199.
. . BOOK-FORMING MINERALS. 351

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; a and A. Lacroix 6 

discovered several of the species under conditions which showed a 

recent origin from cold percolating waters. '

THE CARBONATES.

Calcite. Rhombohedral. Composition, CaCO,,. Molecular weight, 

100.1. Specific gravity, 2.72. Molecular volume, 36.8. Hardness, 3. 

Normally colorless, but often variously colored by impurities.

Aragonite. Orthorhombic. Composition, CaC03 , like calcite. 

Specific gravity, 2.94. Molecular volume, 34. Hardness, 3.5 to 4. 

Color, white, but often tinted by impurities.

Dolomite. Rhombohedral. Composition, CaMgC2 00 . 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 broAvn.

Siderite. Rhombohedral. Composition, FeCO3 . Molecular weight, 

115.9. Specific gravity, 3.88. Molecular volume, 29.9. Hardness, 

3.5 to 4. Color, gray to brown, sometimes white. Breunnerite and 

mesitite are carbonates intermediate between siderite and magnesite 

in composition.

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 n,ot impossible, therefore, that it 

may have formed in some cases during the solidification of a magma 

at great depth.

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.

"Kept..Challenger Bxped., Narrative, vol. 1, pt. 2, pp. 774, 815, 1885. 

6 Compt. Rend., vol. 123, p. 761, 1896. The localities described are in the Pyrenees. 

Plagioclase and scapolite were the parent minerals.
CHAPTER XI, 

IGNEOUS ROCKS.

*' PRELIMINARY CONSIDERATIONS.

i- ; . . ' ;>''( iil-i ;H'_ *.';' ' ' _ . .

When a magma solidifies, ,t}O,.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 depths 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 _i______-_____________ ____ .6

' . " 94. 2

The less abundant rock-forming minerals will make up the remaining 5.8 per cent.0 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

"A somewhat different estimate is given by H. S. Washington in Prof. Paper U. S. 

Geol. Survey No. 14, p. 155, 1903. Its general purport is,, however, much the same as 

mine.

352
IGNEOUS BOOKS. 353

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.

Being mixtures, the igneous r£cks represent an almost infinite 

range of composition.' The minerals which are capable of simultaneous generation from a magma may be commingled in various 

proportions. Eocks', therefore, are not sharply classifiable upon the 

basis of their composition, for they shade into one another through 

all possible gradations, and are separable by no precise dividing lines. 

A mineral is a distinct stoichiometric compound; a rock, except when 

it happens to consist of one mineral alone, is not. Mineralogically 

a rock may be quartz, or olivine, or hornblende, or pyroxene, with 

very little impurity; but these are the exceptional cases. Mixtures 

of two or more components, in variable proportions, form the rule.

Certain mixtures, however, are much more common than others, 

and are represented by widely diffused and abundant rock types. 

Granite, for example, is a mixture of quartz and feldspar, with subordinate ferromagnesian minerals, and samples from different parts 

of the world are surprisingly similar. 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.

14399 Bull. 330 08 23
354 THE DATA OF GEOCHEMISTRY.

At first sight the mineralpgical 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 

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 hot easily avoided. This objection, of course, carries little 

weight, for any classification is liable to be influenced by errors of 

diagnosis. Only, other things being equal, that classification is best 

in which the liabilities to error are fewest. The fundamental difficulty of all is inherent in the nature of our problem; for .in dealing 

with mixtures it is not easy to establish dividing lines, and to decide 

on which side of an imaginary boundary a given rock should be 

placed. This difficulty, which chiefly affects our judgment in dealing 

with intermediate forms, exists in all rock classifications. It can only 

be overcome by conventional devices, which must be more or 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 

from the analytical data are the ultimate criteria. Good analyses are 

easily obtained; their discussion involves no questionable hypotheses, 

and their classification is comparatively easy.0 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

0 Such a classification has been proposed by H. Warth, Geol. Mag., 1906, p. 131. It 

is, however, not quite satisfactory, nor sufficiently elaborated.
IGNEOUS BOCKS. 355

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.

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, C2H6O. Nor is 

this an exceptional case, for organic chemistry takes cognizance of 

similar examples by the thousand. The differences are ascribed to 

different arrangements of the atoms within the molecule, and the 

substances which exhibit this empirical identity are said to be 

isomeric.

Similar instances, although not so sharply defined, and by no 

means so clearly interpreted, are found in mineralogy. The pyroxenes 

and amphiboles, for example, have in general the same molecular 

ratios, while enstatite. and anthophyllite are alike in ultimate composition. Amphiboles, by fusion alone, are transformable into pyroxenes, and the reverse change takes place when pyroxene is altered into 

uralite. Two rocks, then, alike in composition as shown by analysis, 

.and magmatically identical, may be quite different mineralogically, 

the one containing amphibole and the other pyroxene. Analytical 

data will lead us to class them together; mineralogical considerations 

place them apart. This is a simple case, but as rocks become more 

complex, the chances of pseudoidentity increase, and mixtures that 

are very unlike may, as interpreted by analysis alone, appear to be 

the-same. Even when the analyses show empirical difference's, 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,a is of a different order from either of the 

other systems. Rocks, considered in the mass, are variable comminglings of minerals; but the eutectics, being definite mixtures, may be 

taken as the standard types. From this point of view, the groundmass 

of a rock becomes its most characteristic feature, and the phenocrysts 

are only the accidental excesses of one constituent or another over the 

eutectic ratio. The importance of this principle has been already

"Twenty-first Ann. Kept. U. S. Geol. Survey, pt. 3, p. 519, 1901. Science, vol. 20, p. 

550, 1904. Publications of the Carnegie Institution of Washington, No. 31.
356 . THE DATA OF GEOCHEMISTRY.

discussed in a previous chapter,* and its application to petrography 

is foreshadowed in the writings of Guthrie, Lagorio, Teall, Lane, and 

Vogt. 6 That magmas and the products of their solidification must 

be studied on physicochemical lines is generally admitted, and a 

eutectic classification would seem to follow naturally from that kind 

of investigation. At present, however, such a classification is only 

a matter of theory; and its effectiveness can not be tested until a 

reasonable number of eutectics have been identified and described. 

Teall, Lane, and Vogt all agree in thinking that micropegmatite is a 

eutectic mixture of quartz and feldspar, and Vogt has gone still 

further in the development of probabilities. In a recent memoir c he 

has sought to show that a large number of eruptive rocks fell into two 

classes, which he terms " anchi-eutektische " and " anchi-monomineralische;" that is, nearly eutectic and nearly composed of one mineral 

alone. Under the latter heading fall those anorthosites, pyroxenites, 

peridotites, etc., which happen to consist of single minerals to the 

extent of 90 per cent or more. The nearly eutectics he illustrates 

chiefly by the micropegmatites. The suggested eutectics, however, are 

not yet fully established; and- the proposed classification can not be 

attempted until much more experimental work has been done. Its 

difficulties will be chiefly manifest in dealing with multicomponent 

sj^stems; and to anything beyond a three-component group of minerals its application may be impracticable. Its units, it must be observed, are those of the mineralogical system, with which it is much 

more nearly allied than with the classification by radicles or oxides. 

The classification by analyses deals with the latter; the mineralogical 

method with the compounds which actually appear to the eye. To 

a considerable extent the three systems lead to the same grouping of 

rocks,- and it remains to be seen whether the study of the eutectics 

may not bring both physical and chemical data still more into harmony. In a complete classification the systems should converge, each 

one to the reinforcement of the others. The prevalence of a few 

clearly marked rock types may perhaps be explained when the eutectic 

mixtures are known.

" See ante, Chapter IX, pp. 247-250.

"F. Guthrie, Phil. Mag., 4th ser., vol. 49, p. 20, 1875. A. Lngorio, Min. pet. Mittli., 

vol. 8, p.' 421, 1887. Ten 11, British Petrography, pp. 392-402. 1888. A. C. Lane, .Tour. 

Geol., vol. 12, p. S3, 1904. .T. H. L. Vogt, Die Silikatschmelzlosungen, pt. 1, pp. 101-107, 

1903 ; pt. 2, pp. 113-128, 1904 ; and Min. pet. Mitth., vol. 25, p. 361, 1906. Later discussions of the subject are by H. E. .Tohannsoh, Geol. Foren. Forhandl, vol. 27, p. 119, 

1.905 ; S. Zemcuzny and F. Loewinson-Lessing, Geol. Centralbl., vol. 8, p. 393, 1906; and 

A. BygdeX' Bull. Geol. Inst. Upsala, vol. 7, p. 1, 1906.

c Norsk Geol. Tidsskr., vol. 1, No. 2, 1905. 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 plagioclases, as single components.
IGNEOUS BOCKS. . 357 

i

Now, recognizing the fact that all classifications of the igneous 

rocks are at present more or less arbitrary, let us consider the two 

available systems together. We may also take into account a very 

rough, provisional classification of the rocks, which serves.a certain 

descriptive, purpose in helping us to avoid verbiage. I refer to the 

division of rocks into two classes, namely, the " basic " and the " acid," 

to which, if,it were valid, a third "neutral " group should be added. 

These terms, as used by petrographers, have little more than colloquial significance, and serve to indicate whether a rock contains much 

or little silica. They are, however, objectionable and possibly misleading, for the two terms as used in chemistry have a more precise 

and quite dissimilar significance. Their fallaciousness can be illustrated by considering the composition of the two fundamental olivines, 

forsterite and fayalite, Mg,Si04 and Fe,Si04 .

Composition of forsterite and fayalite.

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

FCO.................................................. :........................... 

Forsterite.

42.8

57.2

300.0

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 obviously inapplicable, and the 

case cited is but one of many. It is desirable, then, that the two 

terms should be, generally speaking, dropped from petrographic 

usage and replaced by others which do not conflict with good chemical 

nomenclature.0 Acidic and basylic might be better; but a closer subdivision would be effective by using the self-explanatory expressions 

persilicic, medic-silicic, and sulsilicic. Conventionally these terms 

might represent silica percentages of more than 60, between 50 and 60, 

and below 50. A more precise definition is undesirable. Another 

alternative is offered by the words salic, salfemic, and femic, which 

appear in a classification of rocks to be considered presently.

In the volume upon the " Quantitative Classification of Igneous 

Rocks," & by W. Cross, J. P. Iddings, L. V. Pirsson, and H. S. Washington, the first-named author has given a very full, critical summary 

of the different systems of rock classification which had been seriously 

proposed. To discuss all of these systems, with their nonchemical

0 A few rocks, consisting mainly of corundum or magnetite that is, of basic oxides 

may he properly termed basic. This is the only important exception to the rule here 

laid down. A quartz rock, obviously, would be in the highest degree persilicic.

" Chicago, University of Chicago Press, 1903.
358 - THE DATA OF GEOCHEMISTRY.

features, would be impracticable in a work on geochemistry, and also 

superfluous, for all the details are easily found elsewhere.* 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 alumina, 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, A1203 .................................................. C.

Orthoclase, K2O.Al203 .6Si02 -........... or.

Albite, Na2O.Al203 .6Si02 ............... ab.

Anorthite, CaO.Al203 .2Si02 ............. an.

Leucite, K2O.Al203 .4Si02 ................ lc.'

Nephelite, Na2O.Al203 .2Si02 ............. ne.

Kaliophilite, K2O.Al203 .2Si02 ........... kp.

Sodalite, 3(Na2O.Al203 .2Si02).2NaCl.... so. 

Noselite, 2(Na2O.Al203 .2Si02).Na2S04 .. .no..

....... F.

Feldspars.

......................-L.

Lenads, b or feldspathoids.

Mineralogically, mu'scovite, 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

"Among the modern classifications the following-are especially important: H. Rosenbusch, Elemente der Gesteinslehre, p. 66/1898. .T. J. H. Teall, British Petrography, pp. 

70-77, 1888. F. Loewinson-Lessing, Compt. Rend. VII Cong. geol. internat, p. 193, 1897. 

A. Osann, Min. pet. Mitth., vol. 19, p. 351, 1900 ; vol. 20, p. 399, 1901; vol. 21, p. 365, 

1902; vol. 22, pp. 322, 403, 1903. Osann's system .is distinctly chemical; the others are 

.mineralogical. See also the " Kern-theorie " of Rosenhusch (Min. pet. Mitth., vol. 11, p. 

144, 1900), which is a chemical classification of magmas, and the discussion of it by 

W. C. Brogger, Die Eruptivgesteine des Kristianiagebietes, pt. 3, p. 302, 1898. A paper 

by B. Sommerfeldt (Centralbl. Min. Geol. Pal., 1907, p. 2) relates to a part of the Rosenbusch theory.

" From leucite and nephelite.
IGNEOUS ROCKS. 359

varies from its actual or modal composition. A rock containing 

quartz, orthoclase, and muscovite would be represented by a norm of 

quartz, orthoclase, and corundum, with the water of the muscovite 

left entirely out of consideration. The conventional composition of a 

rock, its norm, may be quite unlike its actual composition or, in the 

nomenclature of the new system, its mode. This method of computation, then, does not profess to represent mineral compositions exactly; 

and there is therefore danger that in certain cases it may be misleading that is, if its avowed limitations are not kept constantly in 

mind. In rocks like the mixture cited above corundum does not 

normally occur, as may be seen from the experiments by Morozewicz 

described in the preceding chapter. The intentional variation frotn 

reality is simply an evasion of the difficulties which often arise in calculating from the analysis of a rock its mineral, composition. As a 

mathematical device it is perhaps legitimate, but it must not be misinterpreted.

The group of femic minerals, as its name indicates, is dominantly 

ferromagnesian, but not exclusively so. The species recognized in the 

classification as standard are as follows:

Acmite, Na2O.Fe203 .4Si02........................ac.

Sodium metasilicate, Na2O.Si02 ................. .ns.

 Potassium metasilicate, K2O.Si02 ............... :ks.

Diopside, CaO.(MgFe)0.2Si02 ....................di.

Wollastonite, CaO.Si02 .I........................ .wo.

Hypersthene, (MgFe)O.Si02 .....................hy.

Olivine, 2(MgFe)O.Si02 .........................ol.

.P.

.0.

H.

.M.

.A.

Akernianite, 4Ca0.3Si02 ..................'....... .am.

Magnetite, FeO.Fe203 ........................... .mt.'

Chromite, FeO.Cr203 .............................cm.

Hematite, Fe203 ................................hm.

Ilmenite, FeO.Ti02 .............................il.

Titanite, CaO.Ti02 .Si02 ..........................tn.

Perofskite, CaO.Ti02 .............................pf.

Rutile, Ti02 ....................................ru.

Apatite, 3(3CaO.P205 ).CaF2 ......................ap.

Fluorite, CaF2 .................................. Jr.

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
360 THE DATA OF GEOCHEMISTRY.

amphiboles are not taken into account as normative or standard 

species. In computing the norm of a rock they are treated as mixtures of other molecules by devices like those adopted in the salic 

division. From the norm the mode can be approximately calculated 

by methods which are fully discussed in the " Quantitative Classification." An example of the differences which thus appear may be 

cited from the discussion of Butte granite, on pages 223-225 of that 

work. Under norm is given the composition in standard or conventional minerals and under mode the percentages of the species 

actually present in the rock.

' Composition of Butte granite.

NORM.

Quartz..................... 19.38

Orthoclase.................. 25.02]

Albite..................... 23..58 66

Anorthite.................... 18.07 J

Diopside.................... .671 -,

Hypersthene................ 6. 78/

Magnetite................... 3.01"i

Ilmenite................... 1. 22J

Pyrite..................... .241

Apatite..................... . 31/

Etc........................ .99

67

4.23

55

99.27

MODE.

Quartz..................... 22. 86

Orthoclase.................. 18.35]

Albite..................... 23.06 V58. 09

Anorthite................... 16.68j

Biotite.................... 10.92)

Hornblende................ 3. 56J

Magnetite................... 1.

Ilmenite...................

Pyrite.....................

Apatite.....................

Etc........................ .85

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 normal 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 their application, and give uniformity to 

the discussion of rocks. Upon them the quantitative classification is 

founded.
IGNEOUS ROCKS. 361

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 7 ' I. Pergalane: Extremely salic. ................... s \ 

J fern ^ 1

sal 7 5 ~ II. Dosalane: Dominantly salic .j ....

III. Salfemane: Equally salic and femi

IV. Dofemane: Dominantly femic ..... J

V. Perfemane: Extremely femic...... *

. fern ^1-^3

_ fern ^-5

. .... . .

fern 7

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 

norni 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; le"nads, 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, O; with the 

group of iron ores and titanium minerals, M ; and, second, the accessories apatite, fluorite, pyrite, etc., 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
362 THE DATA OF GEOCHEMISTRY.

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 practically, although not absolutely, repeat each other. These 

orders are as follows:

O 7

1. Perquaric: Quartz extreme....................... ~j > 

2. Doquaric: Quartz dominant...................... ^ <-7-i>-5- 0 75

j} L o

Q 53 3. Quarfelic: Equal quartz and feldspar............ ^ <^~5~^>~x~

s -T O . 5 '

O 31 

. 4. Quardofelic: Feldspar dominant................. ^ < >___

1? 5 /

5. Perfelic: Feldspar extreme...................... Q ^ L <-*-

6. Lendofelic: Feldspar dominant.................. - <_>> - L 31

-T 57

T C O -

7. Lenfelic: Equal feldspar and lenad ............. _ < > -

J O 0

L 7 5

8. Dolenic: Lenad dominant...................... <Sr~>~'o~ j 1 o

L 7

9. Perlenic: Lenad extreme ....................... = >-T-

-T " 1

In Classes IV and V the femic ratio P-J-O : M is used to designate 

the orders. They are:

P+0 7

1. Perpolic: Silicate extreme..................... " ^>-^-

p ! Q y g

2. Dopolic: Silicate dominant..................... ^ ^^"^"3"

3. Polmitic: Silicate and nonailicate equal ........ ^ < -Q- > -gP+0 *3 1

4. Domitic: Nonsilicate dominant................ -** <C ~K~^> -y

5. Permitic: Nonsilicate extreme................. jj < -=-'

In orders 1 to 3 there is also a precisely similar fivefold division 

into sections, which indicate the proportions between pyroxenes and 

the olivine subgroup. In orders 4 and 5 a like subdivision into suborders is based upon the ratio H : T, hematite plus magnetite on the 

one hand and the titanium minerals ilmenite, titanite, perofskite,
IGNEOUS BOOKS. 363

and rutile on the other. It is not necessary for present purposes to 

carry these subdivisions out in detail, for the ratios. are expressed by 

precisely the same fractions as appear in the classes and orders.

Up to this point the quantitative classification has been mineralogical, and expressed in terms of the standard or normative minerals. 

The division of orders into Tangs, 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 

K2 0-)-Na2 0 : salic CaO is the determining factor. . In Classes IV 

and V the molecular ratio of femic CaO-f- (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 K2O and Na2O under 

the general symbol of K2 0, the rangs under the orders of Classes I 

to III develop thus:

1. Peralkalic..

2. Bomalkalic

3. Alkalicalcic.... . ... ......................... ;Pff <-|->4- (JaU o 5

4. Docalcic ..................................... _

5. Percale......................................

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, mm, and Zime the word mirlic is suggested. Uniting 

MgO, FeO, and CaO under the symbol HO we now have in the distinctively femic classes these rangs :

1. Pennirlic. ........... ....................... RQ

2. Domirlic .................................... RQ <_L>JL

R2 0 ^ 1 ' 3

3. Alkalimirlic

4. Domalkalic

R2 0

RQ 

R2 0

RQ

5. Peralkalic

R2 0 3 5

RQ JL>J 

5 ^ 7

RQ

R2 0 7

The femic rangs are again subjected to a fivefold subdivision into 

sections, depending upon the ratio (MgFe)O: CaO; and they are also
364 . THE DATA OF GEOCHEMISTRY.

divided into subrangs which indicate the ratio between magnesia 

and ferrous oxide. So also, in Classes I to III there are subrangs 

based upon the alkalies alone, and these are called, respectively, perpotassic, dopotassic, sodipotassic, dosodic, .and persodic. These subrangs are still further divisible in such manner as to show the ratios 

between the lenad minerals leucite and nephelite, and sodalite and 

noselite, and either of these pairs may be subdivided in the same way. 

In some of these cases a threefold division is employed instead of the 

usual method. In Classes II, III, and IV the rangs are again 

divided into grads, which serve to classify the subordinate minerals. 

In Classes II and III the subordinate femic group is divided according to the ratio P+O: M, jusf 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 KO: R2O;' R2O: CaO; (MgFe) O: 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, 

expressive of different ratios. This process, obviously, can be carried out to any desired degree of minuteness; but for most practical 

purposes four subdivisions are generally enough. These may be 

stated as classes, orders, rangs, and subrangs; the subclasses, suborders, grads, etc., being less useful in actual work. In order to 

express the composition of a rock, or, more precisely, of a magma, 

a simple notation has been devised, which makes use of numerals to 

indicate the several subdivisions. Thus the symbol II..5.2.3 indicates 

that the magma which it represents belongs in Class II, dosalane; 

order 5, perfelic; rang 2, domalkalic; and subrang 3, sodipotassic." 

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, biotitc, 

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,

0 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, pp. 13-15, 1004.
' IGNEOUS BOCKS. 365

some 1 form of classification like that now in vogue would have to be 

retained with it. Good analyses can not be obtained for every rock 

which the geologist is called upon to determine, and in many cases 

he must be content with the results of a microscopic examination. He 

can then say at once that a certain rock consists of alkali feldspar, 

quartz, and subordinate femic minerals, and so define it as a granite 

or rhyolite. To accurately name its subrang is a more troublesome 

matter, and impracticable without analytical data/' 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 EL S. 

Washington,6 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 OF BOCKS.

j 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. 228. 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

i given. Since rocks are aggregates of minerals, all sorts of interme-

" The need of rock names for field use is fully recognized by the authors of the 

quantitative system.

b Prof. Papers U. S. Geol. Survey. Nos. 14 and 28. For analyses made in the laboratories of the Survey, down to January 1, 1904, see also Bull. No. 228. For an extended 

application of the quantitative classification, see Washington's Roman Comagmatic 

Region, Pub. No. 51 of the Carnegie Institution, 190G. For reviews and criticisms of 

the new system, see A. Michel I^vy, Bull. Carte g^ol. France, No. 92, 1903; A. H[arker], 

Geol. Mag. 1903, p. 173; J. W. Evans, Science Progress, vol. 1, p. 259, 1906; E. B. 

Mathews, Am. Geologist, vol. 31, p. 399, 1903 ; and L. Milch, Centralbl. Min. Geol. Pal., 

1903, p. 677. 

\
366 THE DATA OF GEOCHEMISTRY.

diate 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.

THE RHYOLITE-GRANITE GROUP.

In Class I of the quantitative classification, order 1, perquaric, is 

represented by rocks which consist mainly of quartz, such as quartz 

veins and segregations of igneous origin. In order 2, doquaric, Washington places a few-rocks which contain from 53 to 69 per cent of 

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 f amilar 'group of rhyolites and gran-. 

ites. 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, and usually are, subordinate species, 

such as muscovite, biotite, hornblende, etc. Hence the varieties muscovite granite, biotite granite or granitite, hornblende granite, tourma-. 

line 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.® Ehyolite 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. Magdcburyose.

B. From near Willow Lake, Plumas County, California. Analysis by Hillebrand. Described by J. S. Diller as containing pbenocrysts of quartz and feldspar, in a groundmass 

of the same materials. Symbol, 1.3.1.3. .Alaskose. '

a 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 ottered. Am. Geologist, vol. 

'25, p. 229, 1900. On the formation of granite see H. Le Chatelier, Ann. mines, 8th ser., 

. vol. 13, p. 232, 1888. ' 
IGNEOUS BOOKS. 367

C. Obsidian, Obsidian Cliff, Yellowstone National Park. Analysis by J. E. Whitfield. 

Described by Arnold Hague and .T. P. Iddings. A glass, containing ralcrolites of augite 

and ferric oxide,-with traces of quartz and feldspar. Symbol, 1.3.1.3. Alaskose.

D. From Madison Plateau, Yellowstone National Park. Analysis by Whitfield. Not 

described. Symbol, 1.3.1.4.

E. From the Hyde Park dike, Butte district, Montana. Analysis by H. N. Stokes. 

Contains, according to W. I-I. Weed, sanidine, quartz, plagioclase, and biotite^in a groundmass of quartz and feldspar. Symbol, 1.3.2.3. Tehamosc.

F. From " Elephant's Back," Yellowstone National Park. Analysis by Whitfield. Reported by ,T. P. Iddings to contain quartz and sanidine, with a little augite and magnetite, in a glassy groundmass. Symbol, I.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.

I-I. 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. Lussenosc.

Si02

AlsOi

FojOj... ...............................

FcO... ..............................

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

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

Na2 0. ...............................

K8O .................................

H2O ................................

HjO+ ...............................

TiOj............ '................-....

ZrOs..... ............................

i .P2 06 . .................................

i MnO................................

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

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

. FoSi.v. ..............................

J Cl....... .............................

A.

73.23

12.73

.99

.16

.22

.61

1 91

5.17

.53

4.51

.09

.02

.02

100. 19

B.

74.24

14.50

1.'27

' .67

.25

.11

3 00

,3. 66

2.04

.20

.07

.06

.18

.03

100. 28

C.

75.52

14.11

1.74

.08

.10

.78

3.92

3.63

} .39

none

.11

100.38

D.

75.19

13.77

.61

1.37

.09

.68

3.83

3.33

I r<: > .65

none

.02

.29

99.83

E.

74.34

12.97

.75

.54

.86

.85

9 40

4.72

1.03

1.11

.18

.05

.07

.07

.03

100.06

F.

75.34

12. 51

.42

1.55

.32

1.07

4.17

} .86

none

.07

.42

100. 04

G.

75.98

12.34

.85

.93

.13

4.02

4.44

.24

.64

.17

03

03

.07

trace '^

100. 02

H.

71.87

14.53

1.28

1.02-

.48

1.59

5.08

2.84

.06

.22

.41

.04

.10

.08

m

99.63

NORMS.

Q. ...................................

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

hy.. .................................

hm ..................................

il. ...................................

A.

40.7

31.1

15.7

2.8

3.0

.6

.5.

1.1

B.

49 n

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

32.0

3.3

2.8

2.2

Q

E.

38.7

21.0

4.2

2.2

9 4

1 9

F.

36.1

OC A

27.8

5.6

.4n *

.7

G.

OK 1

26.1

33.5

.6

.8

1.4

1 9

H.

27.4

16.7

43.0

8

1

1 9

1.4

'.8

The following aualyses 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. Magdeburgosc.

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. Toscunose.

C. From Prospect Mountain, Leadville district, Colorado. Analysis by L. G. Eakins. 

Described by W. Cross. Contains orthc:lase, plagioclase, quartz, biotite, apatite, magnetite, and zircon. Symbol, 1.4.2.3. Toscanose.
368 THE DATA OF GEOCHEMISTRY.

D. From the Swansea mine, Tjjatic 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.

Si02 . ..............I:...-......:..................,.....

A1 2 03 . ..............................................

Fe2 O3 . ...............................................

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

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

Na2 0 ................................................

KjO .................................................

HjO...................................... ..........

TiOn. ...............................................

ZrOj. ................................................

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

PiO:,..................... ...........................

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

BaO .............:..................................

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

Cr2 03 . ..............................................

Vt03 . ................................................

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

Cu..................................................

FeS2 ... ......'......................................

A.

79.75

10.47

.64

.92

.13

.15

1.36

6.01

.08

.60

.15

.05

.06

100. 37

B.

69.95

15.14

'.83 .38

.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

03

100. 12

D.

71. 56

14.27

} .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..................................................

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

di.......................... ..........................

hy... ...............................................

mt ..................................................

hm. .................................................

U _..............................,..... :..............

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

91 1

29.3

10.6

1.4

.7

1.4

D.

34.2

26.1

25.2

5.8

2.5

1.1

Q

2.3

E.

30.1 t33.9

22.5

7.2

3 2

2.3 *

.6

The subjoined analyses of granites are all by*W. F. Hillebrand: 9

Analyses of rjraiutes.

A. From Currant Creek Canyon, near Pikes Peak, Colorado. Described by B. B. Mathews. Contains microcline, quartz, muscovite, and sericitic aggregates replacing plagioclase and a part of the microcline. Magmatic symbol, 1.3.1.2. Rlaydeburgose.

B. Biotite granite, Sentinel Point, Pikes Peak, Colorado. Described by Mathews. 

Contains microcline, microcline-perthite, quartz, biotite, a little oligoclase, and accessory 

fluorite, apatite, zircon, sphene, ullanite, and magnetite. Symbol, O.I.3. Alaskosc.

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. Owco.se.

D. Biotite granite, Mount Ascutney, Vermont. Described by B. 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, leuooxene, hematite, and apatite, and 

sometimes secondary calcite. Symbol, 1.4.1.3. Liparose.

"A. Gautier (Compt. Rend., vol. 132, .p. 932, 1901) found traces of nitrogen, argon, 

arsenic, and iodine in granite.
IGNEOUS BOCKS. 369

F. Granitlte, near Florissant, Colorado. Described by Mathews. Contains mlcrocllne, 

alblte, quartz, and blotlte. 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. Apllte, Yuba Gap; Sierra County, California. Described by H. W. Turner. Contains orthoclase, quartz, plagioclase, a little microcllne, brown mica, and iron ore. 

Symbol, 1.4,2.3. Toscanose.

SiO,.. ...............................

AlaOs........................;.......

FesOs............... .................

FcO.....................:...........

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

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

Na2 0:. ..............................

KsO... ..............................

HjO-. ..............................

H,0+. ..............................

TiOj...... ...........................

ZrOj................ .................

COS ....... ...........................

Pj06 ...... ...........................

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

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

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

LijO...... ...........................

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

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

FeSj. .................................

A.

74.40

14.43

.89

.22

.07

.58

1.76

6.56

.15

.92

.12

.22

trace

.04

100.36

B.

77.03

12.00

.76

.86

.04

.80

3.21

4.92

.14

.30

.13

trace

36

100.55

C.

73.90

13.65

.28

.42

.14

.23

2.53

7.99

.16

.33

.07

trace

99.75

D.

71.90

14.12

1.20

.86

.33

1.13

4.52

4.81

.18

.42

.35

.04

.2!

.05

.04

.06

.02

100. 35

E.

72.42

13.04

.68

2.,49

.58

.66

3.44

4.97

| 1.21

- .40

.20

.09

.15

100.33

F.

75.92

19 Of.

.33

1.40

.15

4.60

4.15

.16

.32

.05

.03

.04

.12

100.23

G.

74.37

13. 12

.73

.87 ?*;

1.26

2.57

6.09

.05

.25

.29

.06

.10

t/r£LC6

100. 11

H.

76. 03

IQ 3Q

.48

11

n^

1. 28

2.98

5.18

.15

.34

.07

.03

.04

100.33

NORMS.

\ Q

\ or...................................

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

i.i

1.9.6'

E.

29.4

30.0

28.8

3.2

.8

5.0

.9

.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

H.

36. 3

30.6

25.2

5.0

1.0

.7

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.C2.4. Some granites appear in Washington's tables under Class

II, but they are few in number arid represent, probably, intermediate 

gradations toAvard 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 a 

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 proa Or undistributed alumina. 

14399 Bull. 330 08 24
THE DATA OF GEOCHEMISTRY.

portions 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 rlwolite-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 neplieline 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. P. 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. Plileyrose..

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, Yellowstone National Park. Analysis by Hillebrand. Reported by Arnold Hague and T. A. Jaggar as containing plagioclase, Ol'thoclase, 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 segirite. 

Symbol, 1.5.1.5. Tuolumnose.

E. Soda syenite, Douglas Island, Alaska. Analysis by Hillebrand. Described by G. P. 

Decker. Contains mostly albite, with secondary quartz, calcite, and pyrite. Symbol,\ 

1.5.1.5. Tuolumnose.

P. 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. Pulaskosc.

G. Augite syenite porphyry, Copper Creek Basin, Yellowstone National Park. Analysis by Hillebrand. Contains, according to Hague and Jagg'ar, augite, biotite, orthoclase, 

a little hornblende, and quartz. Symbol, 1.5.2.4. Laurvikose.

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. Itiyhwoodose.

I. Syenite, Yogo Peak, Little Belt Mountains, Montana. Analysis by Hillebrand. 

Described hy Weed and Pirsson. Contains orthoclase, oligoclase, quartz, apatite, titanite, 

iron ores, pyroxene, hornblende, and biotite, with traces of decomposition products. 

Symbol, II.5.2.3. Monzonosc.

J. Syenite, La Plata Mountains, Colorado. Analysis by Stokes. 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. 13. 

Wolff to contain anorthoclase, hornblende, augite, sphene, apatite, and magnetite. Symbol, II.5.2.4. AJcerosc.
IGNEOUS ROCKS. 371

SiOj........

AlsOs.......

Fe203 . . .... 

FcO........

MgO. .......

CaO........

NasO.......

KjO........

HaO.......

H,0+......

TiOji.......

'ZrOs.......

COj........

Pj05 .......

S03 ........

Cl. .........

F.... ......

MnO.......

BaO.......

SrO. .......

V,0........

LIjO.......

FeSj.......

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

100.38

B.

06.22

16.22

1.98 

.16

:77

1.32

~ 6.'49

.08

.24

.22

.10

(V)

.04

29

.06

99.97

C.

63.24

17.98

2.67 

.85 

.63

.93

6.27

5.47

.37

.80

.38

.22

.04

.25

.03

.01

trace

100.14

I).

67.53

18.57

1.13 

.08 

.24

.55

11.50

.10

.15

.31

.07

.11

100. 34

E.

63.01

18.47

.06 

. .32 

.06

2. 60

10.01

.39

.05

.27

.13

2.01

.06

.06

.02

.01

2.10

99.09

F.

57.73

18.93

1.97 

1.92 

.91

2.78

5.52

6.11

.22

2.93

.33

.26

.25

.06

.16

.09

.01

.02

100.20

G.

64.40

16.90

1.86 

1.37 

1. 13

2. 60

5.79

4.56

.16

.39

.23

.02

.21

.07

.27

.14

100.10

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

I.

61. 65

15. 07

2.03 

2.25 

3.67

4.61

4.35

4.50

.26

.41

.56

.33

.09

.27

.10

100.15

J.

59.79

17.25

.3.60 

1.59 

1.24

3.77

5.04

5.05

.19

.39

.67

.72

.35

.04

.20

.14

.11

100. 14

K.

58.28

17.89

3.20 

1.73 

1.51

3.69

5.89

5.34

.17

.98

.64

« 9Pi - M

.06

.36

.05

100. 06

NORMS.

o

or..........

no ...........

di.. ........

hy.. .......

ol.. ........

il.. .........

pr..........

ap .........

A.

8.8

35.6

42.4

3.6

3.4

2.4

2.1

.9

B.

5.3

33.9

51.9

2.8

 1.4

1.6

1.0

.3

C.

2.8

32.8

52.9

4.4

 1.6

1.6

1.6

.8

D.

0.6

95.4

1.4

1.3

.5

.2

.5

E.

2.2

83.3

4.4

.6

1.2

^ 1

.3

2.1

F.

36.1

37.7

8.6

4.8

4.5

l.'O

3.0

.6

G.

7.1

27.2

48.7

6.7

5.2

.8

2.8

.5

H.

3.4

45.6

25.2

1 Q

16.0

1.9

1.6

.8

I.

6.2

26.7

36.7

8.3

11.9

5.0

3.3

1.1

........

J.

 3.1

30.6

42.4

9 5

6.7

3.2

1.4

1.2

.8

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 rhyelites. Their magmatic 

range is between 1.5.1.3 and II.5.2.4; so that, despite their mineralogical similarities, they are divided between two classes, but fall 

within each class into the same order, the perfelic. With decrease 

of quartz, at one end of the series, they shade into rocks in which 

the femic minerals are no longer subordinate. Among these femic 

rocks are found varieties which have been named minette, kersantite, 

lampro'phyre, 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:

Analyses of femic syenites.

A. Soda minette, Brathagen, Laugenclal, Norway. Analysis by V. Schmelck. Described 

by W. C. Brogger." Contains, In approximate percentages, 54 soda feldspar, 29 lepldomelane, 18 tegirine-augite, 2| apatite, and 1 sphene. Magmatic symbol, 11.5.2.4. Alecrosc.

JUie JSniptivyesteine cles Kristiauiagebietes, vol. 3, p. 130, 1898.
372 THE DATA OF GEOCHEMISTRY.

B. Soda minette, Hao, Langesuncl Fjord, Norway. Analysis by Schmelck, description 

by Brogger." Contains about 51^ per cent soda feldspar, 26.5 lepidomelane, 16£ diopside, 

21 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. Proicersose.

D. Shonkinite, Beaver Creek, Bearpaw Mountain's, Montana. Analysis by H. N. Stokes. 

Described by W. H. Weed and L. V. Pirsson. Contains anorthoclase, diopside, biotite, 

iron ores, and apatite, with a very little olivine and nephelite. Symbol, 111.5.1.3.

E. Shonkinite, Yogo Peak, Little Belt Mountains, Montana, Analysis by Hillebrand. 

Described by Weed and Pirsson. Contains augite and orthoclase, with biotite, iron ore, 

andesine, apatite, olivine, and a trace of kaolin. Symbol, III.6.2.3. Shonkinosc.

SiO....... .................................. .1........

Alj63 .. ..............................................

FejOs............. ............................. -...-

PcO... ..............................................

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

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

Na»O. ...............................................

KjO. ................................................

H»0........ ..................................:.....

 StO+.. .............................................

TiOs .............. ..................................

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

P2 06 .... ............................................

SO3 ......... ........................................

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

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

ViO................................................. Cr2 o3 . ............:..................................

MnO................................................ MO.. ...................................:...........

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

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

Li 2O ................................................

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

trace?

.03

' .15

.04

.23

.06

100.42

D.

50.00

9.87

3.46

5.01

11.92

8.31

2.41

5.02

.17

1.16

77

.31

.81

O9

.08

.16

.11

.07

.32

.07

100.01,

E.

48.98

12.29

2.88

5,77

9.19

9.65

2 99

A QP»

.26

Cft

1.44

98

.22

f\Q

.43

.08

99.99

NORMS.

ab. ..................................................

ne. ................................'..................

di.... ...............................................

ol...... .............................................

mt ..................................................

il.......... .........................................

hm ..................................................

A.

OC C

32.0

9.5

8.8 ^ s

5.6

5.1

3.2

2.5

B.

28.3

3.3

9.7

16.8

3.2

6.0

3.7

2.7

C.

AA C

6.7

2.3

20.4

8.6

5.8

2.8

1.0

1.6

D.

9Q ^

ft Q

1.1

6.2

28 9

14.8

5.1

1.4

1.7

E.

29.5

C 0

8.6

6.8

26 5

11.7

 4.2

2.6

9 9

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.

a Die Eruptivgesteine des Kristlaniagebietes, vol. 3, p. 139, 1898.
IGNEOUS .ROCKS. 373 

NEPHELITE ROCKS.

In the norms of the foregoing rocks small quantities of nephelite 

appear. These mark a transition from the syenites and trachytes 

proper, to the phonolites and nepheline syenites, in which the lenad 

minerals replace the alkali feldspars to a greater or less extent. 

Taking the nephelite rocks first in order, we find an eruptive and a 

deep-seated group, just as with the trachyte-syenite series. Quartz 

is excluded from these rocks, for if it were introduced in excess into 

the magma it would convert the lenads into feldspars, nephelite into 

albite, and leucite into, orthoclase. In phonolite we have commonly 

orthoclase, nephelite, and pyroxene; tinguaite is a varietal name. 

Some rocks richer in femic minerals than the phonolites have been 

classed with the basaltic basanites, but they contain 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 II. N. Stokes. Collected by 

B. K. Emerson, but not described. Magmatic symbol, I.G.I.4. Miaskosc.

B. Fhonolite, Black Hills, South Dakota. Analysis by W. F. Hillebrand. Described 

by W. Cross. Contains orthoclase, nephelite, aegjrite, noselite, sodalite, sphene, apatite, 

and zircon; also secondary zeolites and calcite, but no magnetite. Symbol, I.G.1.4. 

Miaskose.

C. Phonolite, Cripple Creek, Colorado. Analysis by Hillebrand. Described by Cross. 

Contains orthoclase, nephelite, sodalite, noselite, ffigirite, etc. Symbol, I.G.1.4. Miaskosc.

D. Phonolite, Pleasant Valley, Colfax County, New Mexico. Analysis by Hillebrand. 

Reported by Cross to contain nephelite, alkali feldspar, ajgirite, traces of magnetite, 

and a little nosellte or sodalite. Symbol, I.G.1.4. Miuskose.

E. Tinguaite, Bear Creek, Bearpaw Mountains, Montana. Analysis by Stokes. Described by W. H. Weed and L. V. Pirsson. Contains orthoclase, nephelite, cancrinite, 

augite, ajgirite, apatite, a little sodalite,'and a doubtful hornblende. Symbol, II.G.I.:?. 

Judithosc.

F. Phonolite, Uvalde County, Texas. Analysis by Hillebrand. Reported by Cross to 

contain orthoclase, nephelite, and ffigirite, with a very little hornblende, angite, and magnetite. Symbol, 11.0.1.4. Laurdalose.

' G. Basanite, near Big Mountain, Uvalde County, Texas. Analysis by Hillebrand; 

description by Cross. Contains alkali feldspar, augite, magnetite, olivine, nephelite, 

ajgirite, biotite, and zeolitic minerals. Symbol, II.6.2.4. Esscwosc.

H: Bassanite, Mount Inge, Uvalde County, Texas. Analysis by Hillebrand; description by Cross. Contains orthoclase, nephelite, hornblende, augite, ajgirine-augite, olivine, 

magnetite, apatite, and a trace of pyrite. Symbol, II.7.1.4. Lujavrose.
374 THE DATA OF GEOCHEMISTRY.

SiOj.... .............................

AljOg. ...............................

T^poOi

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

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

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

Na2 0. ...............................

K2O... ...............:.............:

HsO- ...............................

H3 0+...............................

TiO2 . ................................

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

P2O5 . ................................

so3 .....~. ..........................

S.. ..................................

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

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

VsC-3.... .............................

MhO................................

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

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

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

Li 2O... ..............................

A.

54.22

20.20

2.35

1.02

.29

.70

9.44

4.85 .42'

5.57

.38

.11

.19

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

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

100.07

D.

56.24

21.43

2.01

.55

.15

1.38

10.53

5.74

.12

.86

.26

no

.06

.10

.03

.12

.08

.08

.03

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

.60

.16

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

.15

..04

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

.08

.08

99.97

H.

48.13

18.44

1 41

4.30

3.06

5.89

8.00

3.80

.18

1.59

1.74

.05

.49

.09

.29

.00

.i9

.02

.10

.10

99.93

NOEMS.

ab. ..................................

di... .................................

ol... .................................

il..... ...............................

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

9 Q

13.8

8.0

1.0

1.2

F.

29.5

23.6

30.4

7.4

4.9

. 6

.8

G.

16.7

23.6

8.3

18.7

l'5.9

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

The following table contains analyses of deep-seated rocks of the

nephelite series:

' Analyses of deep-seated nephelite rocks.

A. Elaeolite syenite, or litchfieldite, Litchfield, Maine. Analysis by L. G. Eakins. 

Described by W. S. Bayley. Contains elseolite, two feldspars, and lepidoinelane, with 

accessory sodalite, cancrinite, and zircon. Magmatic symbol, 1.5.1.4. Nordmarkose. 

 B. Elaeolite syenite, Beemersville, New Jersey. Analysis by Eakins. Described by 

J. P. Iddings. Contains nepbelite, orthoclase, segirite, and biotite, with less melanite, 

titanite, apatite, magnetite, and zircon. Symbol, 1.5.6.3. Beemcrose.

C. Nephelite syenite, Brookville, New Jersey. Analysis by G. 'Steiger. Described by 

P..L. Ransome. Contains alkali feldspars, altered nephelite, amphibole, biotite, cancrinite, plagioclase, muscovite,. aegirine-augite, apatite, fluorite, and traces of magnetite, 

with secondary analcite, sericite, and natrolite (?). Symbol, 1.6.2.4. Viezzenose.

D. Elaeolite 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, II.5.1.4. Umptekose.

E. Nephelite syenite, Cripple Creek, Colorado. Analysis by Hillebrand. Described by 

W. Cross. Contains alkali feldspars, nephelite, sodalite, augite, some .-egirine, hornblende, biotite, sphene, apatite, and magnetite. Symbol, II.5.2.4. Akcrosc.

F. Urtite, Kola Peninsula, Finland. Analysis by N. Sahlbom. Described by W. 

Ramsay. Geol. Foren. Forhandl.,"vol. IS, p. 463, 1896. Contains, in percentages, nephelite, 85.7; pyroxene, mostly regirite, 12.0; and apatite, 2.0. Symbol, II.9.1.4. Urtosc.
IGNEOUS BOCKS. 375

G. Ijolitc, livaara, Finland. Analysis by A. Zilliacus. Described by W. I-Iackman, 

Bull. Comm. geol. Finland, No, 1.1. 1900. Contains, in average percentages, nephelite, 

51.6; pyroxene, 39.2; apatite, 4.3; titanite, 2.1; and ivaarite, 0.7. Symbol, 11.9.1.4. 

Urtosc.

H. Theralite, Crazy Mountains, Montana. Analysis by I-Iillebrand. Contains, according to .T. E. Wolff, augite, cegirite, biotite, sodalite, nepbelite, feldspar, apatite, magnetite, and titanite. Symbol, III.7.1.4. MaMgnose.

SiOj.. ...............................

AlaOa...... ..........................

FcO.. ................ ............... Mgo. ........... .......:.............

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

KsO...... ...........................

H80-. ...............................

HsO+...................... -...-....

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

ZrOs.... .............................

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

PsOs.................................

80s... ...............................

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

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

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

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

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

VsOs.. ...............................

LisO. ................................

~A.

60.39

22.57

.42

2.26

.13

.32

8.44

4.77

1 57 I ~ 57

.08

99.95

B.

53.56

24.. 43

2.19

1.22.

.31

1.24

6.48

9.50

} .93

.16

99.96

C.

5468

21.63

2.22

2.00

1.25

2.. 86

7.03

4.58

.27

1.88

.79

.28

.07

.22

.05

99.81

D.

59.01

18.18

1.63

3.65

1.05

2.40

7.03

5.34

.15

.50

.81

 to

.03

.08

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

99.77

F.

45.28

27.37

3.53

49

.33

1.22

17.29

3.51

} .40

.19

99.61

G.

43.02

24.63

3 HQ

9 17

1 96

5.47

14.81

2.99

M

.70

99.97

H.

44.65

13.87

6.06

2 04

. 5.15

9.57

5. 67

.96

2.10

.95

.11

1.50

.01

.17

.76

.37

99.93

NORMS.

or. .!..................................

ab. ...................................

lc...... ................................

SO. .........................:.........

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

di..... ...............................

ol.. ..........................'........

hm ..................................

il...... ..............................

ap.... ...............................

A.

28.4

' 52.4

1.7

10.2

2.9

3.1

>

56.2

3.4

27.5

1 1.3t

.9

3.2

C.

27.2

35.6

14.2

12.8

2.6

7 9

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

9 n

.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

8.2

1.1

1.7

H.

20.7

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 111.7.1.4. The mineralogical variations are great enough
376 THE DATA OF GEOCHEMISTRY. 

<

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.0

LEUCITE ROCKS.

The leucite-bearing rocks are much less common than those carrying nephelite, and, like the latter, have been designated by various 

names. The following examples among those containing little or no 

soda-lime feldspar will suffice to show their composition:

Analyses of leucite rocks.

A. Pseudoleucite-sodallte tinguaite, Bearpaw Mountains, Montana. Analysis by H. N. 

Stokes. Described by W. H. Weed and L. V. Firsson. Contains orthoclase, nephelite, 

sodalite, noselite, aegirite, diopside, and fluorite. Magmatic symbol, II.7.1.3. Jtmeirose. 

Although leucite is not reported here, it appears abundantly in the norm.

B. Arkite, or leucite syenite, Magnet Cove, Arkansas. Described and analyzed by 

H. S. Washington, Jour. Geol., vol. 9, p. 616, 1901. 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 ollvine-free leucite ba.salt. Contains leucite, augite, iron oxides, 

rarely biotite, and a little glassy base. Symbol, III.8.1.2. Chotose.

E. Leucitite, Alban Hills, Italy. Described and analyzed by Washington, Am. Jour. 

Sci., 4th ser., vol. 9, 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 43. 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.

a A very full description of the Norwegian nepheline syenites is given by W^ C. 

'Brogger in his work Die Eruptivgesteine des Kristianiagebietes, especially in part 3 

(1898). Laurdalite, heumite, nepheline porphyry, foyaite, and hedrumite are the 

nephelite rocks described in this memoir. A remarkable rock, found in Dungannon 

Township; Ontario, has been described by F. D. Adams, Am. Jour. Sci., 4th ser., vol. 17, 

p. 269, 1904. 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 

nioninouthite and its norm differs widely from its mode.
IGNEOUS BOCKS. 377

SiOj..... .......................

Al,03 .... .......................

FesOs... ........................

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

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

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

Na2O.... .......................

KsO.... ........................

H8 0-. .........................

HiO+... .......................

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

ZrOa... '........................

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

P805 ... ..........................

S03 .... .............'...........

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

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

Crs03 ... .........................

Dia03 ............ ...............

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

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

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

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

LisO..... ......................

A.

51.93

20.29

3.59

1.20

.22

1.65

8.49

9.81

.10

.99

.20

.25

.06

.67

70

97

.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

none

100.65

F.

42.65

9.14

5.13

1.07

10.89

12.36

.90

7.99

2.04

2.18

1.64

1.52

.58

.03

.47

.07

.11

.12

.89

.33

100.11

G.

46.06

10.01

3.17

5.61

14.74

10.55

1.31

5.14

} i:44

.73

.21

.05

.03

.32

90

99.57

NORMS.

1C...... .........................

no. .............................

di. .............................

wo .............................

ol..............................

mt ........................'.....

hm .............................

11...............................

ft..............................

A.

33 9

18.7

9.8

5.3

10.2

5.7

.5

B.

1.1

37.9

29.8

9.6

12.0

4.9

1.8

2.8

C.

44.5

10.5 1.7

7.4

13.9

7.9

.8

4.1

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

n q

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.0 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. 6 By fusing biotite and microcline together, 

Fouque and Levy c obtained a mixture of leucite, olivine, and maga On ttie formation of leucite in igneous rocks, see I-I. S. Washington, Jour. Geol., vol. 

15, pp. 257, 357, 1907. Also in his Roman Comagmatic Region, Pub. No. 51 of the 

Carnegie Institution, Washington, 1906.

6 See H. Backstrorn, Geol. Foren. Forhandl., vol. 18, p. 155, 1896.

c Syntliese des minGraux et des roches, p. 77.
378 THE DATA OF GEOCHEMISTRY.

netite, together with a mineral resembling melilite, which, however, 

could not be that species. A magma, then, which would form 

biptite under pressure, will lose water if it solidifies at the surface 

of the earth, and may generate olivine and leucite.

The other lenad minerals, sodalite, noselite, and haiiynite, are also 

noteworthy constituents of certain rare rocks, which we need not 

consider in detail. Sodalite syenite, haiiynophyre, and nosean sanidinite are names of rocks in which these minerals are conspicuous.0

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.

ANALCITE ROCKS.

The occurrence of analcite as a primary mineral was first recognized by W. Lindgren,6 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," and W. Cross d 

has found it to be commonly present in the phonolites of Cripple 

Creek. According "to L. V. Pirsson," the supposed "glass base" of 

monchiquite is really analcite. This rock was originally described 

by M. Hunter and H. Rosenbusch f 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 leu cite 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, p. 286, ISijis1/ Contains, in percentages, orthoclase, SO; albite, 16; hornblende, 23; sodalite, 8; arialcite, 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, p. 182, 1898. Contains,'. in percentages, 

analcite, 37.4; albite, 20.9; nephelite, 10.9; orthoclase, 17.3; segirite, ,10.2 ; pyroxene, 

3.3. Symbol 1.6.1.4. Miaskose. '

a For analyses see Washington's Tables, Prof. Paper TJ. S. Geol. Survey No. 14, pp. 

201, 215, 303, 305, 349, 351, 1903.

" 6 Proc. California Acad. Sci., 2d ser., vol. 3. p.. 51, 1891. 

c See citations under analcite in Chapter X, ante, p. 300. 

rt Sixteenth Ann. Rept. U. S. Geol. Survey, pt. 2, p. 32, 1896. 

« Tour. Geol., vol. 4, p. 679, 1896. 

t Min. pet. Mitth., vol. 11, p. 454, 1890.
IGNEOUS ROCKS. 379

C. I-Icronite, Heron Bay, Lake -Superior. Analysis by H. W. Charlton. Described by 

A. P. Coleraan, Jour. Geol., vol. 7, p. 431, 1899. Contains, in percentages, analcite, 47.0 ; 

orthoclase, 28.24 ; labracloritc, 1.8.0; scgirite, 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 chlorite. Sy.mbol, 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. 

Mitth., vol. 11, p. 445, 1890. 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. Aualcite basalt, near Cripple Creek, Colorado. Analysis by Hillebrand. Described 

by W. Cross. Contains augite, olivine, .analcite, alkali ^feldspars, biotite, and apatite. 

Symbol, 111.6.2.4. Monchiquose.

SiOs... ..............................

M*0a.. ....................... --...-.

¥oiO3 ..............:.. ...............

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

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

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

Na2 0 ...............................

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

H2 0-.. .............................

H9 0-f... .......................:....

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

ZrOa. ................................

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

Pa05 . ................................

S03 . .................................

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

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

CrjOa................................

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

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

SrO... ...........................'...

LisO.................................

A.

5C.45

20.08

1.31

4.39

.63

. 2.14

5.61

7.13

.26

1.51

.29

.13

.43

.09

100. 45

B.

56.75

20. 69

 3.52

.59

.11

.37

11.45

2.90

.04

3.18

.30

.28

100. 18

C.

52.73

20.05

3.43

.99

.17

3.35

7.94

4.77

.69

4.85

<M

.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

.32

.15

99.90

E.

46.48

16.16

' 6.17

6.09

4.02

7.35

5.85

3.08

| 4.27

.99

a 1;

100.91

F.

48.35

13.27

4.38

3.23

8.36

9.94

3.35

3.01

. .90

2.89

.52

v\

.40

.25

.19,

.04

.54

.09

100.01

G.

47.82

13.56

4.73

4.54

7.49

8.91

4.37

3.23

] 3.37

% .67

1.10

-.04

.16

.21

100.20

H.

45.59

12.98

4.97

4.70

8. 36

11.09

4 53

.1.04

.51

3. 40

1.32

. 03.

.91

.05

.14

.13

.12

99.87

NORMS.

di....................................

ol ....................................

il....................................

ap. ..................................

A.

41.7

28.3

10.6

3.4

5.9

6.1

1.9

.6

B.

17.2

46.6

23.6

6.0

.5

.5

2.6

C.

28.4

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

i5.2

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.
380 THE DATA OF GEOCHEMISTRY. 

THE MONZONITE GROUP.

The rhyolite-granite series of rocks, and the trachyte-syenite series 

also, are defined by the predominance in them of alkali feldspars, and 

commonly of orthoclase. The andesite-diorite series, on the other 

hand, is characterized by plagioclase feldspars; but between these 

rocks and those already described there are all sorts of gradations. 

Between the orthoclase and plagioclase rocks, therefore, considerations of convenience have led to the formation of an intermediate 

group, whose granitoid members are known as monzonites. Quartz 

monzonite corresponds to granite, monzonite to syenite, and so on. 

The effusive equivalents, intermediate between trachyte and andesite, 

have been named latites. All 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 monzoniles and latites.

A. Quartz monconite, Hailey, Idaho. Analysis by W. F. Hillebrand. Described by 

W. Lindgren. Contains quartz, orthoclase, microline, 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-a'ugite 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. 0. Smith. Contains orthoclase, plagioclase, quartz, hornblende, biotite, magnetite, 

apatite, zircon, and titanite, with a little chlorite and epidote. Symbol, II.4.3.3. Earsose.

B. Monzonite (yogoite), Yogo Peak, Little Belt Mountains, Montana. Analysis by 

Hillebrand. Described by W. H. Weed and L. V. Pirsson. Contains ortboclase, oligoclase, pyroxene, hornblende, biotite, apatite, titanite, iron ore, and a little kaolin. Sym- 

-bol, II.5.2.3. Monsonose.

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. Monnonose.

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 BOOKS. 381

SIOj. .......... ..............'.........

AljOg. ...............................

Fe>03 . ...............................

.FcO.. ................................

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

NasO. ................................

KjO.... ..............................

HsO-.. .............................

H»0+.. .............................

TiOj. ................................

ZrO2 ................................

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

PiO». ................................

S... .................................

S03 . .................................

ct...... .I...........................

ViO». 4 . ..............................

MnO...................... ..'........,

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

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

LiaO. ..........................'......

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

.12

.03

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

.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

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

100. 19

F. '

59.43

16.68

2.54

3.48

1.84

4.09

3.72

5.04

.27

' .72

1.38

.08

.58

.05

trace

.14

100.04

G.

56.19

16.76

3i05

' 4.18

3.79

0.53

2.53

4.46

.34

.66

.69

.55

.10

.19

100.02

H.

57.42

18.48

3.74

2. 10

1.71

6.84

4.52

3.71

.08

.28

.86

.36

none

.03

.09

.15

-s .08

100.45

NORMS.

Q. ...................................

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

cli....... .............................

hy. ..................................

il.. ..................................

ap . .................

A.

9*1 i

25.6

26.7

13.1

.3

5.0

1.4

.9

B.

19 1

27.2

v\ 4

.12.1

.4

4.1

3.5

1:4

C.

19 d

26.7

35.6

15.0

.8

9 Q

9 1

1.6

2.0

D.

14 6

26.1

24.1

16.7

2.4

5.8

^ fi

1.7

E.

25.0

28.8

11.1

19.1

o o

9 fi

1.5

1.3

F.

8.4

29.0

"V\ Q

13.9

2.3

15 S

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

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 1 porphyritic forms analogous to the quartz 

porphyries. For dacites and quartz diorites a single group of 

analyses must suffice, as follows: .

Analyses of dacites and quartz diorites.

A. Dacite, Bear Creek Falls, Shasta County, California. Analysis by R. B. Riggs. 

Described by J. S. Diller. Contains plagioclase, with a little sanidine, hornblende, quartz, 

magnetite, some pyroxene inclusions, and glass. Magmatic symbol, 1.4.2.4. Lass'enose.

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, rnica, and accessories. Symbol, 1.4.2.4. Lassenose.
382 THE DATA OF GEOCHEMISTRY.

G. Dacite, Sepulcher Mountain, Yellowstone National Park. Analysis by J. E. Whitfleld. Described by J. P. Iddings. Contains plagioclase,.quartz, biotite, and hornblende. 

Symbol, 1.4.3.4. Yelloicstonose.

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. Contains plagioclase, quartz, hornblende, brown mica, 

iron ore, and apatite. Harsose.

F. Quartz-mica diorite, Electric Peak, Yellowstone National Park. Analysis by Whitfield. Described by Iddings. Contains plagioclase, orthoclase, quartz, biotite, hornblende, 

angite, and hypersthene. Symbol, II.4.3.4. Tonalose.

. G. Quartz-mica diorite, Yaqni Creek, Mariposa County, California. Analysis by G. 

Steigcr. Described by Turner. Contains plagioclase, quartz, biotite, hornblende, a little 

pyroxene, iron ore, and apatite. Symbol, 11.4.3.4. Tonalose.

II. Quartz-mica-hornblende dibrite, 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 epiidote. Symbol, II.4.4.3. Bandose.

SiOj.. ...............................

AlsOs................................

FesOa-.-.... -.-.....--..-- ......- -.

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

MgO.. ........:.:..... ...............

Na»O. ...............................

K2O .................................

HjO-. ..............................

HS0+. ..............................

TiO2 . ............................. ...

ZrOa.. ...............................

CO!..........-.....................--.

PsOj. ................................

S03 . ................................. ci.......... .........................

VjOs.-.- ------ .......................

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

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

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

LisO. ................................

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

A.

68.10

15.50

3.20

.10

3.02

4.20

3.13

2.72

.15

.03

.06

100.21

B.

70.36

15.47

.98

1.17

.87

3.18

4.91

1.71

.06

1.00

.20

.11

.06

100.08

C.

65.66

15.61

2.10

2.07

2.46

3.64

3.65

2.03

} 1.07

1.37

.13

.12

.36

100.27

D.

57.98

13.58

3.11

8.68

2.87

2.01

3.56

3.44

} 2.47

1.75

.29

.13

.04

99.91

E.

57.26

6.51

<^ 10

3 41

6.69

9 M

2.93

.20

.95

.53

on

.18

.10

.06

100.23

F.

65.11

16.21

1.06

3 1Q

2

C7

3.97

4 00

9 M

j- .94

.71

.02

.04

100. 33

G.

58.09

17.46

1 19

C f\Q

4 06

6.24

2

QA

90

1 4^

QC

.21

.17

.05

.02

.07

.04

100. 37

H.

>;a v?

16.10

2 SO

fi 19

9 }**

7 39

2

1 1

1.01

.21

1.27

1.41

no

07

CO

.18

100.07

NORMS.

Q. ...........:.......................

ab. ..................................

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

di............................. .......

hy. ..................................

il. ...................................

tn...................... .............

A.

25.4

18.3

35.6

14.2

.7

3.2

.4

B.

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

1.1

F.

18.5

15.0

33.5

18.9

.8

9.7

o 1.6

1.4

G.

11.2

12.2

24.6

28.4

2.1

16.0

1.8

H.

21.3

6.1

17.8

31.4

4.5

10.0

A O

2

0

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.
IGNEOUS ROCKS. 383

They contain plagioclase as a principal constituent, with subordinate 

biotite, hornblende, or pyroxene. Six analyses of andesites are given 

in the next table.

Analyses of andestites.

A. From Pikes Peak, Colorado. Analysis by W. F. Hillebrand. According to W. 

Cross, it contains plagioclase, orthoclase (?), augite, iddingsite, hypersthehe, flakes of 

limonite., and a little tridymite. Magmatic 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 blivine. Symbol, 11.5.3.3. Shoshonosc.

D. Augite-bronzite andesite, Unga Island Alaska. Analysis by Hillebrancl. 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, II1.5.3.3. Kcntallcnosc.

SiOi.... ..................................

AI,03 . .............. ......................

Fe3 03 .....................................

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

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

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

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

KjO.. .................................... H,o-.........:.................. ........

H,0+. ...................................

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

ZrOj......................................

PS 05 . .....................................

Vj03 .. ....................................

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

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

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

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

LisO. ......................................

FeSs.... ...................................

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

30.14

4.11

4.48

4.82

7.72

2.99

3.54

.63

2.24

1.01

.48

.04

.21

.01

.20

. .10

.05

99.94

D.

56. 63

16.85

3.62

1 44

4.23

7.53

3.08

2.24

.80

.51

 .67

.16

.04

.23

09

.06

100.18

E.

56.88

18.25

2 OK

4.45

4.07

7 53

3 29

1 49

.24

50

.45

.30

.18

.11

.04

100.06

F.

50. 59

11 49

1 81

7.64

U 97

8 70

9 97

9 11

.21

1.76

.80

.48

.04

.17

.00

.10 '.03

99.86

NORMS.

Q. ........................................

di.. .......................................

hv.. ......................................

il........ ................-...-.-.....:....

A.

1.0.2

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. '

2Q.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

on Q

r q

10 o

3

c

F.

1 Q ft

19.4

13 9

22.4

8.7

14.1

9 <\

1.5

1.0

Diorite is the plutonic equivalent of andesite. It is commonly 

defined as a granitoid rock consisting chiefly of plagioclase, with 

either- biotite OK hornblende, or both; but many diorites carry pyrox-
384 THE DATA OF GEOCHEMISTRY.

ene 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 

It. A. Daly. Contains hornblende, augite, biotlte, 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, II.5.2.4. 

Akerose.

C. Diorite, Crazy Mountains, Montana. Analysis by Hillebrand. According to J. E. 

Wolff it contains biotite, labradorite, augite. orthoclase, quartz, magnetite, apatite, and 

Hornblende. Symbol, II.5.3.3. Shoshonose.

D. Tonalite, South Leverett, Massachusetts. Analysis by L. G. Eakins. Described by 

B. K. Emerson. Contains feldspar, hornblende, and epidotic quartz veins. . Symbol,

11.5.3.4. 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,

11.5.3.5. Beerbachose.

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. Camptonosc.

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. Auvergnosc.

SiOs.................................

AljOs.. ..............................

Fe2O3 ..... ...........................

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

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

NasO. ...............................

KsO........'.........................

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

H8O+ ...............................

TiO».. ...............................

ZrOa...... ...........................

COa........... .......................

P208 . ................................

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

F. .................... .:.... ......... ViOa...... .....................:....:

Cr2O3 . ...............................

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

(NiCo)O ............................

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

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

FeSa. ................................

A.

57.97

' 17. 28

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

.09

.02

100.69

D55.51

16.51

1.68

4.57

6.73

6.73

3.19

2.46

} 1.53

.91

.17

.11

.02

100. 12

E.

'57.87

16.30

1.71

3.86

. 5.50

5.53

5.01

.75

.26

2.40

.53

.27

.08

.05

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

ni

.15

fid

.10

.05

.20

01

.04

.36

99.80

H.

46.91

15.85

2.86

9.95

7.01

Q fi9

2.65

.69

.24

1.62

2,03

.26

.03

.01

.22

.03

99.98
IGNEOUS BOOKS.

NORMS.

385

Q. .,......'...........................

di....................................

hv. ..................................

of........................... .........

11.....................................

A.

4.9

24.5

37.2

15.0

2:5

6.9

3.2

2.9

1 ^

B.

7.7

16.1

44.0

11 Q

5.7

5.5

^ 9

1 9

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

0.

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 Avell explained.* The following analyses 

relate to basalt, as the unqualified term is commonly used.

\ Analyses of basalts.

A. Basalt, early flow, Table Mountain, Colorado. Analysis by L. G. Eakins. Described 

by W. Cross. Contains augite, olivine, plagioclase, probably orthoclase, magnetite, apatite, and a little biotite. Magmatic symbol, II.5.8.3. Shoshonose.

B. Basalt, Saddle Mountain, Pikes Teak, Colorado. Analysis by W. I'\ Hillebrand. 

Described by Cross. Contains augite, olivine, plagioclase, orthoclase, magnetite, biotite, 

and apatite. Symbol, li.5.3.4. A.ndose.

C. Quartz basalt, .Cinder Cone, near Lassen Peak, California. Analysis by Hillebrand. 

Described by .t. 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 .Toaquin River, Madera County, California. Analysis by Hillebrand. 

Reported by H. W. Turner to contain pyroxene, partly augite, plagioclase, olivine, 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, 11.5.4.3. 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.

O. Basalt, Pine Hill, South Britain, Connecticut. Analysis by Hillebrand. Described 

by W. H. Hobbs. Contains pjagioclase, augite, olivine, andx magnetite. Symbol, III.5.4.3. 

Auvcrgnuse.

" See .T. S. Diller, Bull. U. S. Geol. Survey No. 79, 1891. 

143!:)!) Bull..330 OS 25
386 THE -DATA OF GEOCHEMISTKY.

Ah03 .......... ................

FesOs........ I.......:.........

FcO............................

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

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

Na2 0 ..........................

K»0............................

UsO...........................

HaO+..........................

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

PaOa. ................... .......

S03 .. ..........................

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

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

NiO.................. !.........

BaO........ '...................

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

Li 2 0...... .....................

FeSj...........................

A.

49.69

18.06

2.64

6.19

5.73

8.24

2.99

3.90

\ 91 I -y

.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

.00

.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

.16

.03

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

9.80

 2.81

.29

.39

.74

.57

.15

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

.13

99.99

NORMS.-

Q.. ............................

di......... ......................

hy.. ...........................

ol....................... ........

il.. ...................... .......

A.

22.8

19 4

24.5

3.1

9.4

12.8

3.7

. 1/7

1 9

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

9.0

 - 18.9

2.3

1.1

D.

15.6

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 373-379.

Analyses of basaltic rocks.

A. Kulaite, Kula, Lydia, Asia Minor. Described and analyzed by H. S. Washington,

 Tour. Geol., vol. 8, p. 613, 1900. 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. Esscwose.

B. Leucite kulaite, Kula. Described and analyzed by Washington, loc.-cit. Contains, 

in percentages, anorthite, 17.9 ; albite, 23.0;' leucite, 17.4 ; nephelite, 12.8; diopside, 13.8 ; 

olivine, 9.5 ; magnetite, 3.7. Symbol, II.6.2.4. Ksnexosc.

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. Limlturgose.

D. Leucite basalt, I-Iighwood 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, meiilite, leucite, biotite, 

magnetite, some zeolites, and a trace of nephelite. Symbols, IV,16.1.2. Venanzose.
.' IGNEOUS ROCKS. 387

F. Nephellte basalt, Tom Munn's Hill, Uvalcle County, Texas. Analysis by Hillebrand. 

Described by Gross. Contains olivine, augite, nepbelitc, magnetite, and apatite. Symbol, 

IV.2S.1.2. .'Uvaldose. ' . '

G. Nephelite basalt, Black Mountain, Uvalcle County, Texas. Analysis by Hillebrand. 

'Described by Cross. Contains olivine, augite, uephelite, magnetite, and apatite. Symbol, 

IV.2-M.2. Uvaldose. ' ' . H. Nephelitc-melilite basalt, near Uvalde, Texas. Analysis by Hillebrand. Described 

by Cross. Contains nepbelite, nieliUte, olivine, augite,-apatite, and magnetite. Symbol, 

IV.'23.1.2. Cassclosc.

SiOj. ................................

Al,03 . ................................

FesOj................................

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

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

NaaO ................................

KsO.... .............................

HsO-. ..............................

H2 0+.. .............................

TlOs.................................

PoOS03 . .................................

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

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

ViOs.... .............................

Crj03 ... ...... '............ ............

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

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

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

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

LijO. ................................

A.

48.35

19.94

2.48

5.25

5.15

7 98

5.47

3.99

.16

.22

.84

99. 95

B.

49.90

19.89

2.55

4.78

5.05

7.21

. 5. 00

3.74

.13

19

93

99.97

C.

45.11

12.44

 2.07

9. 30

1.1.58

10. 01

3:05

1.01

.10

.78

.51.

.01

.11

.04

.22

.04

100. 02

D.

40.04

12.23

3.80

4.00

10.38

8.97

2.42

5.77

/. Ol

1 14

.48

- .25

99.70

E.

41. 43

9.80

3. 28

5. 15

13. 40

10. 02

1.04

7.40

},,!

29

100. 12

F.

40. 32

9.40

4.75

7.48

18. 12

10. 55

2. 02

1.10

.57

1.25

2.00

.08

.01

.03

.05

.04

.25

.00

.00

.03

100.09

G.

39.92

8.60

4.40

 8.00

20. 17

10. 08

1.91

1.03

.43

1.45

2.70

.51

.07.

.04

.14

.24

.06

.06

.04

100. 45

H.

37. 96 

10. 14

3.09

7.59

14. 69

16.28

2.18

.69

.39

1.82

2.93

1.13

.04

.03

.07

.05

.08

.22

.04

.00

.05

100. 13

NORMS.

Ic

cli. ....................................

ol.................... ................

il. ...................................

A.

23.4

8 9

18.1

20.1

10 A

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

0.8

5 20.4

19 8

3.9

4.3

1.1

D.

22.2.

5.3

11.1

9.0

26.3

5.0

1 2

2.0

E.

4.8

25:0

4.2

OO Q

29.8

2.8

.6

F.

3.3

11.1

11 9

2.0

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,
388 THE DATA OF GEOCHEMISTRY.

Analyses of diiibase.

A. Turnpike Creek, Kittitas County, Washington. Analysis by W. F. Millebrand. 

Reported by G. O. 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, with probably a little quartz. Symbol, 11.4.4.3. Bundose.

C. Shoshone Canyon, Yellowstone National Park. Analysis by Hillebrand. Contains, 

according to Arnold Hague and T. A. Jaggar, plagioclase, augite, and chlorite. Symbol, 

.11.5.3.4. Andosc.

D. Aroostook Falls, Maine. Analysis by Hillebrand. Description by H. E. Gregory. 

Contains plagioclase, pyroxene, pyrite, apatite, chlorite, and a little calcite. Symbol. 

11.5.3.5. Bcerbachose.

E. Diabase porphyry, near Milton, Sierra County, California. Analysis by Hillebrand. 

Described by I-I. W. Turner. Contains plagioclase, augite, and hornblende. Symbol, 

.111.5.3:4. Camptonosc.

F. Mount Ascutney, Vermont. Analysis by Hillebrand. Described by R. A. Daly. 

Contains plagioclase, augite, and magnetite. Symbol, II1.5.4.3. Auvergnose.

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

A12 03 . ....................................

Fes03 . ....................................

FeO

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

Ca.0. .....................................

Na2 0. ....... .............................

K2 O ......................................

H»0-. ...................................

H8 0+.... ...............-.............:...'

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

COs................................ ...... .

:p8 o6 . .....................................

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

VsOj....... ...............................

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

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

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

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

Li 2 0. .....................................

FeS2 . .....................................

A.

57.21

12.99

3.28

10. .1.8

1.59

5.97

3.07

1.61

.68

1. 03

1.72

.44

.24

.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

.94

100. 05

G,

52.18

.18. 19

3.31

4.36

4.69

6.51

4.58

1.88

.75

. 2.00

.99

.29

trace

.14

.11

.06

100. 04

P.

49.64

15.07

1.66

8.82

5.43

7.23

4.19

.89

.45

2.81

2.32

.32

.29

.04

.25

.02

.05

79

100. 27

E.

51.27

12. 14

2.51

6.71

10.86

10.32

2.00

1.03

.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

I. 47

1.68

1.36

.25

.07

.17

.04

.22

100.17

NORMS.

Q. ........................................

di........... ...............................

hy. .......................................

ol...... ...................................

il.... .....................................

pr. .......................................

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.

].5

4.4

21.0

25.9

16.6

19.8

4.2

3.2

THE GABBROS.

The gabbros, which are the granitoid equivalents of the basalts 

and diabases, consist mainly of plagioclase and pyroxene, with various admixtures of other minerals. At one end of the series .we have 

anorthosite, or labradorite rock, which is almost entirely composed 

of feldspar; at the other end the plagioclase diminishes in amount, 

and the rocks approach the pyroxenites. Normal gabbro contains
IGNEOUS BOCKS. 389

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 gabT)ros.

A. Anorthosite, Monhegan Island, Maine. Analyzed and described by E. C. E. Lord, 

Am. Geologist, vol. 26, p. 340, 1000. Nearly pure plagioclase. Magmatic symbol, 1.5.5. 

Canudane-.

B. Gabbro, near Emigrant Gap, Placer County, California. Analysis by W. F. IT1 liebrand. Described by W. Lindgren. Contains biotite, hypersthene, diallage, plagioclase, 

and orthoclase. Symbol, II.5.3.4. A.nilonc.

C. Gabbro, Emigrant Gap, California. Analysis by Hillebrand. Described by Lindgren. Contains hypersthene, diallage, plagioclase, and orthoclase. Symbol, III.4.3.4. 

Vaalose.

D. Norite, Elizabethtown, Essex County,. New York. A.nalysis by Hillebrand. Described by .T. F. Kemp. Contains labradorite, hypersthene, garnets, augite, hornblende, 

biotite, magnetite, and apatite. Symbol, HI.5.3.4. Camptonosc.

E. Bronzite norite, Crystal Falls, Michigan; Analysis by G. Steiger. 'Described by

.T. M. Clements and H. L. Smytb. Contains bronzite, hornblende, and labradorite. Symbol, III.5.4.3. Auvergnosc.

F. Olivine gabbro, Birch Lake, Minnesota. Analysis by FI. N. Stokes. Contains a 

large proportion of diallage and olivine. Symbol, HI.5.4.3. Auvergnoso.

G. Hypersthene gabbro, Wetheredville, Maryland. -Analysis by Hillebrand. Described 

by G. H. Williams. Contains hypersthene, diallage, plagioclase, magnetite, and apatite. 

Symbol,' III.5.5. Kedabekase.

H. Hypersthene gabbro, Gunflint Lake, Minnesota. Analysis by Stokes. Described by 

W. S. Bnyley. Contains hypersthene, biotite, diallage, magnetite, and plngioclase. Symbol, IV. 1.1.2. CooJiosc.

SiOt. ................................

A\2 03 . ...............................

FeO. ....... ......................... Mgo.. ...,.......:..................

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

NasO. ............................... KsO. ..................:.............

'HtO-. ..............................

HsO+.. .............................

TiO2 .... .............................

COs... ...............................

PjOi.. ..............................

S.. ..................................

V,0S .. ...............................

Crj03 ........ ........................

MnO. ............................... NIG. ........................:......-.

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

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

LisO .................................

A.

45.78

30.39

1.33

1.22

2.14

16. 66

1.66

.10

} .5,

99.79

B.

55.40

1 ^ 39'

2.70

5.49

5.75

9.90

2.89

1.52

.03

.38

.00

.22

.11

.07

100. 38

C.

55.87

13. 52

2.70

5.89

0.51

8.87

2.42

1.72

.09

1.50

.56

.25

.10

.02

100. OS

'D.

47.16

14.45

1.61

13.81

5.24

8.13

3.09

.1.20

.12

.48

3.37

.35

.57

.14

(?)

.24

.02

99.98

E.

48.23

18. 20

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

.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

.93

.06

100. 09

NORMS.

Q....... .............................

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

di. ...................................

hy. ..................................

ol..................... ...............

il....................................

A.

6.6

12.1

75.1

1.1

0.1

2.5

1 9

B.

<; 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
390 THE DATA OF GEOCHEMISTRY.

These figures, with a range from persalane to dofemane, from 

1.5.5 to. IV.1.1.2, are enough to show the vagueness of the terms 

gabbro and norite. Although it is difficult to see why B and C 

should be separated, being placed in different classes, orders, and 

rangs, the quantitative system brings out the general diversity of 

character better than the ordinary mineralogical classification. It 

separates things which, with the exception above noted, are essentially distinct.

; FEMIC ROCKS.

From the feldspathic. gabbros rocks pass by insensible gradations 

into varieties which are wholly femic, or nearly so, the p}^roxenites. 

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 pyroxenite 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." The following table deals \vith the rocks in which pyroxenes predominate:

Analyses of pyroxcnites.

A. Cortlandtite, Belchertown, Massachusetts. Analysis by L. G.' Eakins. Described 

by B. K. Emerson. Contains hornblende, pyroxene, biotite, olivine, and magnetite. Magmatic symbol, IV.Kl.l. Belcherose.

B. Weiu-iite, near Red Bluff, Montana. Analysis by Eakins. Described by G. P. Mer-

'rill. Contains olivine, diallage, brown mica, rarely plagioclase, and secondary Iron 

oxides. Symbol, IV.13 .1.2. Wehrlose.

C. Hornblende picrite, North Meadow Creek, Montana. Analysis by Eakins. Described by Merrill. Contains hornblende, olivine, pleonaste, iron oxides, and occasionally 

hypersthene. Symbol, IV,13.1.2. We7w7o.se.

D. Pyroxenite, Baltimore County, Maryland. Analysis by J. E. Whitfield. Described 

by G. I-I. Williams. Contains hypersthene and diallage. Symbol, V.I1 .!.!. Maricose.

E. Websterite, Webster, North Carolina. Analysis by E. A. Schneider. Described by 

Williams. Consists of diopside and bronzite. Symbol, V.l 1 ^.!. Weltsterose.

F. Websterite, Oakwood, Maryland. Analysis by W. F. I-Iillebrand. Described by 

A. G. Leonard. Contains hypersthene and diallage. Symbol, V.l 1 .!^. Cecilose.

G. Lberzolite, Baltimore County, Maryland. Analysis by- T. M. Chatard. Described 

by Williams. Contains olivine, bronzite, and diallage; the olivine partly serpentinizcd. 

Symbol, V.12,1.1. Baltimoria.se.

H. Pyroxenite, Baltimore County, Maryland. Analysis by Whitfield. Described by 

Williams. Contains hypersthene and diallage. Symbol, V.I2 .!.2. Baltimorose.

a Two analyses of hornblendites are given in Washington's tables, Prof. Paper U. S. 

Geol. Survey No. 14, pp. 345, 359, 1903.
IGNEOUS ROCKS. 391

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

A1 2 03 . ...............................

Fe2 03 . ................................

FcO. ....... ....... ........

MgO.. .................:.............

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

Na20............................'....

K2 0 .................................

HjO.......... ......................

H'aO+. ..............................

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

P2 05 . ................................

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

S. ....................... . .........

S03 . .................................

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

V2 03 .. ...............................

Cr2 03 ................................

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

(NiCo)O.... ........... .

FeS2 .................................

A.

48.63

5.32

2.91

3 90

21.79

13.04

.34

.23

} 2.81

.47

.21

.36

19

.100. 13

B.

48.95

5.09

1.20

12.11

23.49

5.33

1.58

.79

I IS f - 18

.81

.12

.05

.08

.16

100. 54

C.

46.13

4.69

.73

16. 87

25.17

4.41

.08

} 1.38

.73

.07

.24

.04

.09

100.63

D.

51.94

2.53

2.88

9.38

25.97

3.60

} 2.82

19

.16

.60

100.07

E. 

55.14

.66

3.48

4.73

26. 66

8.39

.30

} .38

.23

, .25

(W

.11

100.30

P.

53.21

1.94

1.44

7.92

20.78

13. 12

.11

.07

.14

.87

.20

.10

.03

.20

99

.03

no

100. 47

G.

43.87

1.64

8.94

2.60

27. 32

6.29

| '.50

1.08

7.64

.12

.44

.19

100.03

H.

50.80

3.40

1.39

8.11

. 22. 77

12.31

1 52 / - 52

.24

.32

.17

100.03

NORMS.

Q...............................:....

or. ................... .. ....

ab ......... ........

an .....

di .................. .. . ... ...

Iiy ... .. or..........:::...../""""::""" jut...... ..

il. ...................................

A.

1.1

2.6

19 ^ .

41.7

21. 9

11.7

5.1

B.

5.0

13. 6

5 f;

16.5

1O C

37.6

1.6

1.5

C.

.5 19 f;

7.6

44.8

30 4

g

1.2

.D.

.6

6.7

8.9

76.4

9 S

E.

1.7

2.6

32.7

57.1

5.1

F.

.6

1.0

3.- 2

48.9

2.1

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

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 pre-- 

dominance over the olivine. The following analyses represent 

peridotites: . Analyses of peridotites.

A. Cortlandtite, llcliester, Maryland. Analysis by W. F. Hillebrand. Described by 

G. H. Williams.. Contains olivine, pyroxene, and hornblsnde partly altered to talc. Magraatic symbol', IV.I4 .1.1. Cortlantltosc.

B. Peridotite, near Silver Cliff, Colorado. Analysis by L. G. Eakins. Described by 

W. Cross. Contains hornblende, biotite, byperstbene, oliviue, a little plagioclase, apatite, 

pyrrhoti'te, and sillimanite. Symbol, I AM4.!. 2. Gnstensc.

C. Peridotite, near Opin Lake, Michigan. Analysis by Hillebrand. Described by C. R. 

Van Wise and W. S. Bayley. Contains diallage, olivine, magnetite, <ind plagioclase. 

Symbol, IV.2-M..2.

D. Mica poridotitc, Critteuden County, Kentucky. Analysis by Hillebrand. Described 

.by .T. S. Dillcr. Contains biotite, serpentine, and perofskite, with less apatite, inuscovite, magnetite, calcite, chlorite, and other secondary products. Symbol, IV.24.1.2. 

Subraug of Casseliase.

JO. Saxouite, Douglas County, Oregon. Analysis by F. W. Clarke. Described by .T. S. 

Diller and F. W. Clarke. Contains olivine and enstati.te, with a little magnetite and 

chromite. Symbol, VJA1.1.

F. Dunite, Corundum Hill, North Carolina. Analysis and description by T. M. Chatard. Contains olivine, with a little chrornite. Symbol, V.1A1.1. Dunose.
392 THE DATA OF GEOCHEMISTRY.

G. Peridotite, Tulameen River, British Columbia. Analysis by Hillcbrand. -Described 

by J.' F. Kemp. Contains olivine and serpentine, with magnetite, magnesite, and calcite. 

Symbol, V. 1s. 1.1. Dunose.

Al»0s. ..........................

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

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

 Na2 0. ...........................

K2 0... .........................

HjO...........................

H»0+. .........................

TiOj...........................

COj... .......................:.

PS 05 ... .-.........-..-..-...-..

S....... ........................

01. ............ ..................

MnO ...........................

NiO...... ......................

A.

. 39. 20

4.60

3.45

6.15

31.65

3.23

.42

. .14

.50

9.38

w

.41

.20

30

100.15

B.

46.03

9.27

2.72

9.94

25.04

3.53

1.48

.87

I <M

> .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

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

.18

.56

100.34

G.

38.40

.29

3.42

.6.09

45. 23

.35

| .08

.24

4.11

1.10

.06

,07

.24

.10

100. 38

NORMS.

HG

Ic. .............................

C........ .......................

di.. ............................

hy... ...........................

bl ..............................

am .............................

il...... .........................

cm.

nr\

A.

0.6

3.1

10.6

4.4

.16.8

47 Q

5.1

.9

B.

5.0

12.6

16.1

16.7

44 'i

3.9

.4

C.

1.7

4.2

9.2

7.4

21.1

37.5

7 9

1.2

1.0

D.

8.G

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.

0.9

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 

this manner. Theoretically, no doubt, the quantitative classification 

applies only to fresh material; practicalry it is applied to altered 

peridotites, like those cited above, which all appear in Washington's 

tables. .
IGNEOUS ROCKS. 393

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:

Analyses of basic and titaniferous rocks.

A. Corundum pegmatite, Ural Mountains, Siberia. Described and analyzed by J. Morozewicz, Min. pet. Mitth., vol.-18, p. 210, 1898. Contains corundum and ort.hoclase, with 

accessory rutile, apatite, and zircon. Magmatic symbol, P.S.l.S! Vralosc.

B. Kyschtyniite, Borsowka, Ural Mountains. Described and analyzed by Morozewicz, 

op. cit., p. 212. Contains corundum, with a little spinel, anorthltc, biotite, and zircon. 

Symbol, I1 .5.5. KyscMymasc.

C. Ilmenite norite, Soggendal, Norway. Described', and analyzed by C.. P. Kolderup, 

Bergens Museums Aarbog, 1896, p. 165. Contains, in approximate percentages, ilmenite, 

87.5; hypersthene, 40.1; anortliite, 11; albite, 8.7; orthoclase, 0.9. Symbol, IV.3T .1.3. 

Bcryenose.

D. Titaniferous iron ore, Lincoln Pond, Essex County, New York. Analysis by W. P. 

Hillebrand. Described by J. F. Kemp. Symbol, 1V.4-.1.4. AdirondacJticise.

E. Titaniferous iron ore, Elizabethtown, New York. Analysis by Hillebrand. Described by Kemp. Symbol, IV.^.l^. Ghamplainiase.

F. Magnetite spinellite, Routivaara, Finland. Analyzed and described by W. Petersson, 

Geol. Fo'ren. Forhandl., vol. 15, p. 49, 1393. Symbol, V.5l.1.4. No magmatic name 

assigned.

A1 2 03 .....................................

Fc2 03 ........................... ..........

FcO. ...................................:.

MgO. .....................................

CaO ...............................:......

Na2 O .....................................

K2 0 ...................................... H2 o .............................:........

Ti02 . ......:..............................

C02 .. .....................................

P,05 . .....................................

s. ........................................

01. .......................................

VS 0S .. ....................................

Cr2 03 . ....................................

MnO..................... '................

Corundum. . ..............................

A.

40.00

13.65

.35

.15

.30

3.71

5.20

.40

35. 40

99. 28

B.

10.80

13.89

.70

.61

7.20

.38

.13

.70

« 59. 51

100. 10

C.

31.59

8.54

24.52

2.36

10.70

2.25

1.03

.15

18.49

.02

99. 05

D.

11.73

6.40

30.68

27.92

3.35

3.95

.50

.26

.64

12.31

.32

.82

.04

.12

.04

.05

99. .1.9

E.

13.35

8.75

20.35

28.82

0.63

2.15

1.68

10.45

.17

.02

.09

.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

Including a little spinel.
394 THE DATA OF GEOCHEMISTRY.

NORMS.

ab........ .......... ...................... .

1C.......... .................:........-.... .

C....:.. ..................................

hy....... ................................

ol.........................................

il........................... ..............

MgO..............".....'...................

FeO.......................................

A.

30.6

27.2

1.4

9 1

30.8

.7

 B.

0.0

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 9 }

1.3

44.5

23.7

1.9

E.

 10.8

4.8

5.7

14.8

29.5

31.0

F.

1.1

2.0

3.1

4.0

48.5

26.8

3.9

6.9

The cumberlandite. of Cumberland, Bhode Island, a peridotite rich 

in titaniferous magnetite, also belongs in this group; and many other 

similar mixtures are known. The New York ores 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. Maximum silica.

Albite, NaAlSigOs. ....................

Enstatite, MgSi03 . ...................

Albite, NaAlSi 3O8 . ....................

Minimum silica.

Nephelite, NaAlSi04 .

Fayalite, Fe2Si04 ..rUllvrae0 Melitite, a basic silicate, is here left purposely out of account, and so, too, is akermanite.
. IGNEOUS ROCKS. 395

Intermediate minerals, such as analcite, Motite, muscovite, etc.. that 

contain water, can form only under pressure!? or conditions of viscosity 

which prevent the water from expulsion.

The two oxides in the foregoing list ca:n 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 f<re 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.0 The exception does riot invalidate the broad general statement that the two species are essentially incompatible. Much magnetite and much quartz do not occur together in rocks of igneous 

origin.

Similar incompatibilities are shown elsewhere in the table. Leucite 

and silica will form orthoclase; nephelite and silica yield albite; a 

member of the olivine family with silica will be converted into 

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

l lt has also been mentioned in Chapter IX, on the molten magma.
396 THE DATA OF GEOCHEMISTKY.

words, we encounter the well-known fact that two rocks may have 

the same ultimate composition and yet contain different mineral 

species. The difficulty of apportioning the several bases to the several minerals in a rock is familiar to everyone who has tried to 

discuss any large number of rock analyses. Potassium may form 

orthoclase, leucite, muscovite, or biotite; sodium may }deld albite, 

nephelite, analcite, alkali hornblende, or acmite; calcium appears in 

pyroxene, 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. Eocks midway between these extremes, with 

silica ranging .from 45 to 55 per cent, contain the greatest variety of 

minerals, for ortho-, meta-, 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,a as follows:

a Elernente der Gesteinslehre, 1898, p. 40.
IGNEOUS ROCKS. 397

1. Apatite, zircon, spinel, the titanates, and iron ores. These are almost invariably the first minerals to crystallize.

2. The Mg-Fe, Mg-Ca, and Fe-Ca silicates, such as divine, amphibole, and 

pyroxene. Biotite is also placed in this class. As a rule the orthosilicates 

precede the rnetasilicates; olivine, for example, separating before pyroxene.

o. 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 alumosilicates, and especially of feldspars and quartz. That is, they contain predominantly compounds of the same class, in which the other 

rock-forming minerals are dissolved. The latter separate from 

solution in the general order of their solubility, the least soluble 

first; but that property varies with the composition of the mixture. 

In an isomorphous series, like the feldspars, the least fusible tend to 

be deposited earlier than the others, but fusibility is a minor factor 

in the process of solidification. Quartz, which solidifies in most cases 

at the very end of the series, is a relatively infusible substance; but, 

as AVC 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 Si3O8 , 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; in some cases the computation is easy, in others 

it is impossible. The conventional " norms" of the quantitative 

classification can always be -calculated, but the actual composition 

may be quite another thing. It is the latter which concerns us now. 

Let us take some concrete examples for discussion.
398 THE DATA OF GEOCHEMISTRY.

Two rocks of relatively simple composition are the folloAving, for 

which data are given in Survey Bulletin No. 228, 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. Liparosc.

B. Biotite granite, El Capitan, Yosemite Valley. Analysis by W. Valentine. Described 

by H. W. Turner. Contains alkali feldspar, plagioclase, quartz, biotite, frtanite, apatite, 

and iron oxides. The analysis shows that a trace of zircon is probably present also. 

Toscanose.

ANALYSES. NORMS.

AlsOs.........................

FeaOa

FeO. ...........................

MnO. .........................

MgO. ..........................

CaO ..........................

SrO. ......-..:.................

BaO. .........................

Na2 0.........................

KsO.. .........................

HsO-.. .......................

H2O+... ..........:..... ......

TiOj... .......................

ZrOs.......... ................

pao6 .... ......................

Cl. ............................

A.

68.05

.56

.08

.12

1 00

.10

.13

4.86

4 74

.27

.83

.20

01

99.88

B.

71.08

15.90

.62

1.31

.15

.54

2.60

09

.04

1 =;4

4.08

 wi

.22

.08

.10

.02

100. 60

Q. ...........................

c.. ...........................

hy.. .........................

A.

20.2

27.8

40.9

5.0

3.5

.3

.2

.4

.

B.

27.8

23.9

29.9

13.1

.9

3.3

.9

In calculating the actual composition of these rocks, it is best to 

first eliminate the accessories. ZrO2 is calculated as zircon, Fe2Oa 

as hematite or magnetite, P2O5 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 Na2O 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 AL,(MgFe) 2KHSi3 012 . 

Upon comparing K2O with the remainder of the ALO3 , 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 

 \yhen that is 'deducted, only quartz and orthoclase remain to be considered. The orthoclase is given by the K2 0 and A12 O3 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.
IGNEOUS BOOKS. ' ' 399

Calculated composition of rocks represented 'in preceding table.

Albite...... ............................................................................

MgSiOg... ............................. .^.... ...........................................

~

A.

19.98

18.90

41. 07

5.41

13.06

.30

.17

.11

. 50

99.56

B.

29.64

19.74

29.87

12.23

6.50

.12

.54

.24

.93

99. 81

These calculations are simple enough, a,nd the results are fairly

accurate. The chief uncertainties are with the micas, arid especially 

with the biotite in B, for rock-forming biotite is a mineral of variable 

composition, and their errors affect the computations A^dth 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, plagloclase, 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 plivine 

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, Avhen the 

areas occupied by the several minerals can be measured with a micrometer. Given a sufficient number of such measurements, and, the 

densities of the minerals being known, the relative proportions of the 

elements may be calculated, and the results obtained can be checked 

by the chemical analysis." A. cruder process consists in taking an en-

«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, p. 34, 1.905), the micrometer method is unsatisfactory. See also A. 'Kosiwal, Verhandl. K.-k. geol. Reichsanstalt. 1898, p. 143.
400 THE DATA OF GEOCHEMISTKY.

larged 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. Iddiugs, 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.
CHAPTER XII.

THE DECOMPOSITION OF ROCKS. 

THE GENERA:L 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 

hydra ted 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 poAver 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 assists in producing disintegration.0 The distribution of volcanic dust is still another mode by which finely subdivided rock is 

rendered available for aqueous decomposition. The latter depends 

for its efficiency partly upon the water itself and partly upon dissolved acids, salts, or gases. Rain water falls upon the surface of a 

"rock and sinks more or less deeply into its pores and crevices. Rain, 

as we have already seen,6 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, hoAvever, is

"This subject is fully discussed by J. C. Brainier, in bis paper upon tbe decomposition 

of rocks in Brazil. Bull. Geol. Soc. America, vol. 7, p. '.>.55, 1896. 

6 See antCj pp. 44 et seq.

14399 B nil. 330 08 26 401
402 THE DATA OF GEOCHEMISTKY.

temporary, for mechanical disintegration is accompanied 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 Avater these active gases 

are concentrated, as shown by the analyses of E. W. Bunsen.tt Air 

extracted from rain water at different temperatures has the composition by volume given below..

Composition, of air extracted from rain water at different temper attires.

Oxvtrpn

0°.

2.92

33. 88

03. 20

100. 00

5°.

2.68

oo 07

63. 35

100. 00

10°.

2.46

34.05

f.'^ 4Q

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,& 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.

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 magmat.ic origin, such as the feldspars, micas, pyroxenes,' 

amphiboles, olivine, leucite, nephelite, and the typical sulphide, 

pyrite. The last-named mineral, although found in relatively small 

proportions, is nevertheless important, for by oxidation and hydration it yields solutions of sulphates having a distinctly acid reaction. 

These acid solutions act strongly upon other constituents of rocks, 

and intensify the activity of the percolating waters. The sulphates

a Ann. Chem. Pharm., vol. 93, p. 48, 1855. See also M. Baumert, idem, vol. 88, p. 17, 

1853.

. b Ber. Deutsch. chem. Gesell., vol. 18, p. 2487, 1885. Evidence of similar purport has 

been recorded by other observers.
THE DECOMPOSITION OF BOCKS. 403

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 MINIGRAJLS.

That nearly all minerals are more or less. attacked by water has 

long fceen known, and also that carbonated waters act still more energetically. The experiments of W. B. and R. E. Rogers,* in 1848, 

established these facts conclusively. Many minerals were tested, and 

all were perceptibly soluble. From 4.0 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. 6 In the classical 

investigations of A. Daubree 0 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 K.O 

with 0.750 of silica. The amount of decomposition was greater, but 

the quantity of potash passing into solution was less. A 3 per cent 

solution of sodium chloride was a much less effective agent than Avater 

.alone. Leucite was not so vigorously attacked as orthoclase.

In 1867 A. Kenngott a showed that many minerals gave an alkaline reaction when in contact with moistened test paper; and in 

1877 R. Miiller c published an important memoir upon the solu- 

 bility 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 o:P 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 soluti.on.

"Am. .Tour. Sci., 2d ser., vol. 5, p. 401, 1848.

6 The temperature at which the experiment was conducted was 60°, presumably 

Fahrenheit.

'; Etudes synthe'tiques de geologic expfirimentale, pp. 271-275. See also p. 252 for an 

experiment upon the solubility of granite.

"Neues Jahi-b., 1867, pp. 77, 769.

0 Jahrb. K.-k. geol. lleichsanstalt, vol. 27, Min. Mitth., p. 25, 1877. Miiller gives a 

good summary of previous work upon the subject, and cites, in addition to the memoirs 

mentioned here, papers by Dittrich, Haushofer, Ludwllg, Hoppe-Seyler, and'others. A 

later summary, by F. K. Cameron and .T. M. Bell, is :ln Bull. No. 80,' Bureau of Soils, 

TJ. S. Dept. Agric., p. 12, 1905. P. Pit-hard (Ann. chira. phys., 5th ser., vol. 15, p. 529, 

1878) 'found that several magnesian silicates gave alkaline reactions with litmus paper. 

F. Sestini (abstract In Zeitscbr. Kryst. Min., vol. 35, p. 511. 1902) made similar, but 

quantitative observations on augitc. nmpbiboln .and trerholite. According to F. Coruu 

(Min. pet. Mitth., vol. 24. p. 417, 1905; vol. 25, p. 489, 1907), who tested many minerals 

with litmus, kaolinite, pyrophyllite, nontronite, etc., give acid reactions,
404 THE DATA OF GEOCHEMISTRY.

Material extracted from minerals by carbonated water.

Do......................

DO.... :...... ............

Do......................

SiO2 .

0. 1552

.237

.419

.873

.354

A1 2O3 .

0. 1368

9. 1713

K2O.

1. 3527

Na20.

2. 367

MgO.

1. 291

2. 649

CaO.

3.213

8.528

1.696

2.168

1 (UK

P205 .

1.417

1.822

2 19

FeO.

4 829

.942

2.428

trace

rf.733

1.527

Sum.

0. 328

.533

1.536

S07

3 . 821

1.529

2. 018

1.976

1.211

The relative solubility of several minerals, chiefly magnesian 

species, in ordinary water was determined by E. W. Hoffmann ° in 

1882. His method of procedure consisted in allowing water to percolate through the powdered material for two months and measuring the loss of weight; a possibility of gain by, hydration seems not 

to have been considered. The data given are as follows:

Relative solubility of various minerals in water.

Talc ...............................................................................

Grams 

taken.

A IflQ

3.353

3.506

2.591

1. 1245

. 5058

.9736

Loss of 

weight.

n nfid

.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 6 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 c Johnstone states that olivine is slightly attacked by carbonated water; and in still another d he described the action of that 

reagent upon orthoclase, oligoclase, labradorite, hornblende, augite, 

etc. Among the feldspars, orthoclase was the least and labradorite 

the most soluble; hornblende and augite were acted upon even more 

rapidly. These observations seem to be in harmony with those of 

Miiller, whose figures show a similar order of magnitude among the 

determined solubilities.

" Inaug. Diss., Leipzig, 1882. 

6 Quart. .Tour. Geol. Soc., vol. 40, p. 363, 1889. 

c Proc. Roy. Soc. Edinburgh, vol. 15, p. 436. 1888. 

d Trans. Edinburgh Geol. Soc., vol. 5, p. 282, 1887.
THE' DECOMPOSITION OF EOC.KS. 405

In recent years a few data have been published by C. Doelter ° 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 b on the alkalinity of several* silicates, Avhich 

Avere followed by some quantitative determinations by G. Steiger." 

Micas, feldspars, leucite, nephelite, cancrinite, sodalite, spodumene, 

scapolite, and a number of zeolites Avere studied, and in every case a 

distinct solubility Avas observed. Apophyllite, natrolite, and pectolite 

gave remarkably strong alkaline reactions \vhen moistened, but the 

intensity of the coloration produced Avith indicators gave inaccurate 

information as to the extent to which decomposition had occurred. 

Between the qualitative and the quantitative data there \vere discrepancies, which have been cleared up only Avithin the last tAvo years. 

A. S. Cushman/1 in his work upon rock powders, has shown that when 

orthoclase is shaken Avith Avater 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, Avhich retain a portion of the separated 

alkali, but give it up to electrolytic solvents. For example, 25 grams 

of orthoclase \yere shaken up Avith 100 cubic; centimeters of distilled 

Avater. The mixture was filtered, and the filtrate on evaporation 

gave 0.0060 gram of residue. With a 2 per cent solution of ammonium chloride a soluble residue of 0.0608 gram Avas obtained. With' 

diabase 25 grams in pure water yielded an. extract of 0.0064 solid 

residue; Avith a 1 per cent solution of ammonium chloride it gave 

0.1412 gram. These gains do not imply increased decomposition, but 

only a liberation of the soluble compounds which had been entangled 

in the colloids that Avere 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 Avith many 

observations upon the tendency of soils and clays to absorb salts, and 

especially salts of potassium, from percolating waters. As the latter change in composition, their decomposing and dissolving capacities are altered; and since the rocks differ in composition, no general 

rule can be laid doAvn to determine what the effects of-waters in any 

particular case Avill be.

Still, in spite of difficulties and uncertainties, Ave can trace the 

course of rock decomposition along several lines. The evidence, both 

as found by experiment in the laboratory and by field observations, 

shoAvs that all minerals, certainly all of the important ones, are attacked

« Min. pet:. Mitth., vol. 11, p. 319, 1890. 

6 Bull. U. S. Geol. Survey No. 167, p. 156, 1900. 

c Idem, p. 159.

(l II. S. Dept. Agric., Bureau of Chemistry, Bull. No. 92, 1905, and Office of Public 

Roads, Circular No. 38.
406 THE DATA OF GEOCHEMISTRY.

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 

i.n conglomerates has been noted by several observers." 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, 6 and is converted, at least superficially, into gibbsite 

or diaspore.

The effect of rain water upon a rock must now be divided into several phases. First, it partially dissolves the more soluble minerals, 

with liberation of colloidal silica, and the formation of carbonates 

containing lime, iron, magnesia, and the alkalies. The iron carbonate 

is almost instantly oxidized, forming a visible rusty coating or precipitate' of ferric hydroxide, The lime, magnesia, and alkali salts 

remain partly in solution, to be washed away, together with much of 

the dissolved silica.

The character of the solution thus formed by the decomposition of 

feldspathic rocks has been investigated by W. P. Headden. 0 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 

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 d in certain granites of the

a See C. W. Hayes, Bull. Geol. Soc. America, vol. 8, p. 213, 1897; M. L. Fuller, Jour. 

Geol., vol. 10, p. 815, 1902; C. H. Smyth, Am. Jour. Sci., 4th ser., vol. 19, p. 282, 1905. 

For the solubility of quartz in solutions of horax or of alkaline silicates, see G. Spezia, 

Jour. Chem. Soc., vol. 78, pt. 2, p. 595, 1900; vol. 80, pt. 2, p. 605, 1901.

6 S. .T. Thugutt, Mineralchemische Studien, p. 104, 1901.

c Am. Jour. Sci., 4th sec., vol. 10, p. 181, 1903.

" Bull. Geol. Soc. America, vol. 6, p. 321, 1895.
THE DECOMPOSITION OF BOCKS. . 407

District of Columbia, and by 0. A. Derby * 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 Avaters. 

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 clay like 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 by the rocks that are formed by their reconsolidation. Mud, 

sand, and gravel yield shales, sandstones, and conglomerates; but 

there are sandy shales and argillaceous sandstones. The separations 

are sometimes fairly complete, but they are oftener imperfect. Swift 

waters are more effective than sluggish ones, both as regards 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 discolora? 

tion 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 doAvn as 

oceanic ooze.

But rain water is not the only chemical agent for effecting rock 

decomposition. Below the surface the ground water is at work, and 

that, con tains 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 

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 reap0 .Tojir. Geol., vol. 4, p. 529, 1896. Holland (Quart. .Tour. Geol. Soc., vol. 59, p. 64, 

1908) mentions deep cuttings in India where the minute structure of the gneiss is retained on surfaces as soft as putty.
408 THE DATA OP GEOCHEMISTRY.

pear 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.0' The impregnation of any solution of alkaline salts by free carbonic acid yields a solvent of this kind. Ground 

water, then, is in many ways different from rain water. As the latter 

sinks deeper and deeper into a mass of rock or soil it undergoes progressive modifications, and some of the changes which it brought 

about at the beginning of. its career may be reversed, while others are 

accentuated. At certain depths the decomposing action of the 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. 6 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. 0 The roots, moreover, 

commonly contain organic acids, which act with much vigor .upon 

mineral substances. The soil or decomposed rock about the roots of a 

tree is often bleached by the solution and removal of its iron contents. 

The studies of H. Carrington Bolton <l upon the solubility of min-

" See E. W. Hilgard, Am. Jour. Sci., 4th,'ser., vol. 2, p. 100, 1896. Hilgard suggests 

that the inclusions of carbon dioxide found in quartz may supply notable quantities of 

that substance to underground waters.

6 In addition to previous references, see also W. B. Schmidt, Min. pet. Mitth., vol. 4, 

p. 1, 18S2, on the action of sulphurous acid upon volcanic rocks.

c See A. Geikie, Text-book of Geology, 4th ed., p'. 600, and G. T. Merrill, Rocks, Rock 

Weathering, and Soils, p. 201.

d Ann. New York Acad. Sci., vol. 1, p. 1, 1877; vol. 2, p. 1, 1880.
THE DECOMPOSITION OF BOCKS. 409

erals 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."

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. Most important of all, on account of their abundance and 

general distribution, are the so-called humus acids, the products of

vegetable decay. Humic, ulmic, crenic, and apocrenic acids are 

reputed members of this family of compounds, which are found 

Ayherever leaf mold accumulates or wood decays. Their constitution, 

in a modern chemical sense, is not well understood ; but they are 

complex compounds, or even mixtures of compounds, of carbon, 

hydrogen, and oxygen, of uncertain formula, and they are produced 

by the breaking down of cellulose. Their solvent power is very 

appreciable, and 'they play an important part, not only in advancing 

the decomposition of rocks, but also in supplying a cement for certain 

varieties of hardpan, and in the deposition of bog-iron ore. !) Through 

assimilation of nitrogen, azohumic acids are formed, and these, 

according to P. Thenard,6' have the power of dissolving silica in 

considerable quantities. The corrosion of quartz pebbles, which has 

already been mentioned, is commonly ascribed to the action of azohumic acid; but the latter probably exerts its chief solvent effect 

upon the gelatinous or colloidal silica thi.it is formed during the 

decomposition of silicates. The relative richness of tropical river 

waters in silica is also attributable to the action of the organic matter 

which they contain."2

OF BACTERIA.

Even such low forms of life as the bacteria seem to exert a definite 

influence in the decomposition of rocks. A. Muntz ° has found the 

decayed rocks of Alpine summits, where no other life exists, swarm0 On this theme there are abundant data, which have; been collected principally with 

reference to agricultural problems. A long table of ash analyses may be found in 

Jahresb. Chemie, 1847-48, p. 1074. For estimates of the amount of mineral matter taken 

from the soil by hemp and buckwheat, see R. Peter, Kentucky Geol. Survey, Chemical 

analyses, vol. A, p. 441, 1884.

b Sec A. A. Julien's monographic paper upon the geological action of the humus acids, 

Proc. Am. Assoc. Adv. -Sci., 1879, p. 311. This memoir is rich in references to literature.

« Compt. Rend., vol. 70, p. 1412, 1870.

d See ante, p. 83.

« Aim. chini. phys., Gtla ser., vol. 11, p. 136, 1887 ; Compt. Rend., vol. 110, p. 1370, 1890.
410 THE DATA OF GEOCHEMISTKY.

ing with the nitrifying ferment. The limestones and micaceous 

schists of the Pic du Midi, in. the Pja-enees, 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 K. Hartleb* 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,6 however, 

has cast doubts upon the validity of Muntz's argument, arid 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,0 and so modify the composition of the 

ground water.

 *

INFLUENCE OF ANEMAX LIFE. ,.:

The influence of animal life in decomposing rocks is perhaps secondary rather than initiative. An ordinary soil contains rock-forming minerals which have been incompletely broken down, and animals 

assist in completing the disintegration. The effects produced by 

guano upon the rocks immediately beneath it may be more direct, but 

their 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 earth .worms perform 

this kind of labor upon a vast scale. In Brazil, as shown by J. E. 

Mills'* and J. C. Brainier," the Avork 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 lea.ves 

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 mv.?t be said upon the destructive influence of man. By drain-

" Zeitschr. angew. Chemie, 1899, p. 4Q2.

"Am. .Tour. Sci., 4th ser., vol. 3, p. 438, 1897.

c See ante. p. 87.

"Am. Geologist, vol. 8. p. 351, 18S9.

« Bull. Geol. Soc. America, vol. 7, p. 255, 1896.
THE DECOMPOSITION OF BOCKS. 411

ing, grading, irrigating, fertilizing, and cultivating the soil, by tunneling, quarrying, and mining, the processes of rock decomposition 

are promoted in many ways. New surfaces of rock are exposed to 

the action of air and water, new solvents are introduced into the soil, 

coal is withdrawn from the earth to be restored to the atmosphere as 

carbon dioxide, and by the destruction of forests erosion is accelerated. The extent to which man assists in the decomposition of 

rocks may easily be overrated; but human influence is one of the 

active agencies which can not be ignored.

PRODUCTS OF DECOMPOSITION.

The products of decomposition are commonly divided into two 

great classes, the sedentary and the transported. The sedentary 

products are those which remain in place, such as residual clays 5 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, kaolinite, and scales of mica, commonly commingled with 

fragments of undecomposed- feldspar; a peridotite is converted into 

serpentine; a rock rich in iron is likely to give much ferric hydroxide, 

and so on. The more easily alterable minerals naturally form the 

more easily alterable rocks, and the residues which they furnish will 

represent the maximum amount of change. That change, furthermore, will be reflected in the composition of the percolating waters, 

which may be rich in silica, or carbonates, or sulphates, according to 

the nature of the minerals upon which they operate.

Many comparative analyses of rocks and their decomposition products are on record.0 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, p. 581, 1875; vol. 28, p. 519, 1876; vol. 35, p. 559, 1883. Other groups of. 

analyses than those cited here are given by E. Kaiser, Zeitschr. Deutsch. geol. Gesell., 

vol. 56, Monatsb., p. 17, 1904 ; and M. Dittrich, Zeitschr. anorg. Chemie., vol. 47, p. 151, 

1905.
412 THE DATA OF GEOCHEMISTEY.

Analyses of rocks and their decomposition products.

A. Micaceous granite, District of Columbia. Described by Merrill, Bull. Geol. Soc. 

America, vol. 6, p. 321, 1895. Contains quartz, black inica, 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 li. L. Packard ; d by G. P. Merrill.

SiOs..........................................1 ..................

AIjOs........ '..................................................

Fe2O3 ........................................................

FeO ...........................................................

MgO....................................................:......

CaO ...........................................................

KsO...........................................................

TiOs. ...........................................................

2 ->

.

a.

69.33

14.33

3.60

2.44

3.21

2.70

2.67

1.22

.10

99.60

A

b.

66. 82

15.62

. 1.88

1.69

2.76

3.13

2.58

2.04

3.27

99.79

c.

65.69

15.23

\ 4.39

2.64

2.63

2.12

2.00

4.70

.31

.05

99.76

d.

49.39

23.84

1 3.69

4.60

4.41

3.36

2.49

8.12

99.90

B. Micaceous gneiss, Albemarle County, Virginia. Analyses and description by G. P. 

Merrill, Bull. Geol. Soc. America, vol. 8, p. 157, 1897. 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 .1. 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-aiidesite, Rockland Ridge, Washington. Analyses, description and full discussion by E. A. Schneider, Am. .Tour. Sci., 3d ser., vol. 36, p. 236, 1888. According to 

A. "W". Jackson, the rock contains plagioclase, augite, apatite, magnetite, and residual 

glass, a, The fresh rock ; b, the derived soil.

SiOi....... .....................

AltOs.. ........................

FejOs.......... ................

FeO............................

MgO...........................

CaO............................

Na2 O ...........................

KaO..... .......................

Ignition....................... HsO...:........................

Organic. ..................".....

TiOs...........................

P2 0S . ..........................

SO.............................

E

a.

60.69

.16.89

1 9.00

1.06

4.44

2.82

4.25

.62

.25

100.08

b.

45.31

26. 55

1 12. 18

.40

.22

1.10

13.75

.47

99.98

a.

59. 70

18.85

| 4.85

.68

1.34

6.29

5.97

1.88

99. 56

C.

b.

58.50

25.71

1 3.74

.44

1.37

1 96

5.85

97.57

c.

50.65

26.71

I 4.87

.21

.62

.62

1 Q1

8.68

.06

94.33

E

a.

50.85

12.54

7.11

5.57

9.33

2.37

1 13

34

.76

.05

100.08

.

b.

58.16

15.03

10. 59

1 99

A <V7

2

C(\

1.77

3.52

<n

.07

100. 37

E. Diabase," Medford, Massachusetts. Analyses and discussion by G. P. Merrill, Bull. 

Geol. Soc. America, vol. 7, p. 350, 1S96. According to W. H. Hobbs the rock contains 

plagioclase, augite, biotite, pyrite, apatite, magnetite, ilmenite, and some secondary products, a, The fresh rock.; b, disintegrated rock ; c, fine silt.

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.

"For data concerning a diabase from Chatham, Virginia, see T. L. Watson, Am. Ceologist, vol. 22, p. 85, 1898. The analyses given are not complete.
THE DECOMPOSITION" OF ROCKS. 413

SiOa. ................................................

Als03 . ...............................................

Fe,03 ........ .......................................

FeO.... .............................................

MgO ................................................

CaO .........:.......................................

NiuO ................................................

K2O... ..............................................

P2 05 .. ..............................................

MnO.... ............................................

a.

47.28

20.22

3.00

8.89

3.17

7.09

3.94

2.16

9 71}

.08

.77

100. 59

E..

ta.

4144

23. .1.9

1 12.70

5.82

f .. 03

J..93

J.75

;,. 73

.70

.52

,9£i.8.l

c.

30.61

1 40.08

4.02

3.44

2. 14

1.82

10.97

99.68

I

a.

40.75

17.61

1 16. 79

5.12

9.46

2.56

.55

.92

.25

100.01

b.

42.44

25. 51

1 19. 20

.21

.37

.56

.49

10.92

.29

99.99

G. Diabase, Spanish Guiana, Venezuela. 'Described by G. Attwood, Quart. .Tour. Geol. 

Soc., vol. 85, p. 586, 1879. 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, Froc. Liverpool Geol. Soc., vol. 7, p. 108, 1892-93. 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 .T. Morozewicz, abstract 

in Zeitschr. Kryst. Min., vol. 30, p. 012, 1004. 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 fi'esh rock, specific gravity 2.988; b, first stage of decomposition, specific 

gravity 2.918; c',"second stage, specific gravity 2.604.

r

,;

SiOa............... '.'.................

AljQa. ...... ..........................

FeO .................................

MgO.................................

CaO .................................

NauO ................................

,K20 .................................

HjO...... ..........................

HS0+. ..............................

TiO2 ... ..............................

C02 ... ...............................

MnO................................

MiiiOs. ..............................

a.

49 57

15.37

12.34

7.41

9 65

1.99

.85

.17

3.10

alOO. 45

G.

b.

41.77

19.34

13 21

4 fit

4.98

.83

.69

2.55

7 30

olOO. 31

c.

4O A£

18/39

20.43

3.46

2.37

.14

.59

3.39

7.95

alOO. 18

I

a.

,JO Kl\

14.58

3.S4

7. CO

0 <K

10.78

1.S6

1.C2

\ , sr

> 3.S5

1.C3

1.S3

.59

99. / 9

I.

b.

44 Q^

16.27 1007

6 40

1.84

2.03

.84

\ 12.55

1.34

.28

99.85

a.

46 97

16.16

10.66

4.38

9.02

4.47

1.26

} 1.74

.14

.75

100. 11

I.

b.

<^fi 49

16. 72

4 32

2.70

3.77

13. 36

4.24

1.52

j- 2.24

.07

.68

100. 04

c.

 47. 22

20.09

5

K1

2.02

4.39

6.93

2. 50

1.52

} 8.78

.66

99.68

0 Including traces of Cu and S. P absent.

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 hydra-
414 THE DATA OF GEOCHEMISTRY.

tion, 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* ............................................................

AloOg.................... .....................................

MnO ..........................................................

MgO ..........................................................

CaO ...........................................................

K20..... ............ ............................................

P205 ... ........................................... ............

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

2.42

.32

.68

1.83

.50

.62

.08

14.93

Diorite.

17.43

3.53

4.97

9.2C

2.17

.21

37.51

II. PERCENTAGE LOSS OF EACH, CONSTITUENT.

Si02 ............................ :......- .............. .......

A1 203 ....... .................. ................................

MnO ..........................................................

MgO..........................................................

CaO ...........................................................

K2 0.. .........................................................

P,05 ............ ...............................................

Granite.

14.89'

3.23

1 49

25.21

28. 62

31.98

40.00

Gneiss.

52.45

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,
THE DECOMPOSITION OF BOOKS. 415

except as to. the main tendencies to alteration, can be based upon

them. Each individual rock alters in accordance Avith the conditions i

to Avhich it has been exposed, but the general trend of the changes 

is always in the same direction. Lime is ahvays removed, but percolating waters rich in carbonic acid Avill carry it away more easily 

than Avaters less heavily charged. OliviiiB will lose magnesia more 

readily than enstatite. The solubility of silica Avill 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, 

IIOAV a given rock AAdll change, Ave can not predict the alteration in its 

quantitative details. 

KATE OF DECOMPOSITION.

; The extent to which rocks undergo decomposition Avithln a giA^en 

time is largely dependent upon climatic circumstances. In the 

polar regions, Avhere Avaters are frozen during a great part of the 

year, solution goes on more sloAvly than in warmer climates. In the 

Tropics the Avaters not only act continually, but their energy is increased by their higher temperatures. Frost is most effective as an 

agent of disintegration in climates Avhere alternations of freezing and 

thaAving" are most 'frequent. As E. W. Hilgard" has Avell said, 

" The chemical processes active in soil formation, are intensified by 

high and retarded by IOAV temperatures, all other conditions being 

equal." Disintegration, however, as distinguished from decay, is 

very active in high latitudes and also in arid regions.** In both 

cases the great alternations of heat and cold promote disintegration,

. Avhereas, for lack of floAving AA^ater, 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 

pOAvder, but much of the debris remains i.n 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 c 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.

n Report on the relations of soil to climate : Bull. IS'o. 3,.U. S. Weather Bureau, 1892. 

"See I. C. Russell, Bull. Geol. Soc. America, vol. 1, p. 135, 1890. Also compare G. P. 

f Merrill, Rocks, Rock Weathering, and Soils, pp. 278, 285. 

c Op. clt, p. 30.
416 THE DATA OP GEOCHEMISTRY.

Average composition of soils from humid <md arid regions.

Soluble Si02 . .......................................................................

AlsOa-...- ..........................................................................

MgO ...... ..........................................................................

CaO.. ..............................................................................

Na20.. .............................................................................

KjO.. ..............................................................................

Ps05 ..... ...........................................................................

803.................................................................................

A.

84.031

4.212

4 296

3.131

.133

.225

.108

.091

.216

.113

.052

3 Kdd

100. 252

B.

7.266

7.888

5. 752

.059

1.411

1.362

.264

.729

.117

.041

4 945

100. 399

That a much greater proportion of soluble matter, unremoved by 

leaching, is present in the arid regions is evident at a glance. The 

desert soils, when supplied with water, are exceptionally fertile, 

because they have retained in a large measure the foods that plants 

require.

KAOLIN.

The chemical products of -rock decomposition are extremely varied, 

as might be naturally inferred from the mineralogical complexity 

of the original masses. In the residues which remain after leaching 

we find free silica, either as quartz or opal, fragments of various 

undecomposed minerals, hydroxides, and a number of the rather 

indefinite substances known as clays. Among the latter kaolinite, 

HjAlgSLCXj, and its ferric equivalent, nontronite, H4Fe2Si2O0 , 

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. Hosier,6 kaolinite is only produced by pneumatolytic action that is, by. the operation of thermal waters and gaseous 

emanations. The other hydrous silicates of aluminum and iron, such

" The equivalency between -kaolinite and nontronite was established by E. Weinschenk, 

Zeitschr. Kryst, Min.. vol. 28, p. 150, 1S97.

6 Neues .Tahi-b., Beil. Bd. 15, p. 231, 1902. Rosier gives a bibliography relative to 

kaolinization, embracing 303 titles. See also 0. Stutzer, Zeitschr. prakt. Geol., 1905, p. 

333, who accepts Hosier's view. B. Wiist, studying a kaolin derived from quartz porphyry, near Halle, Germany, regards the alteration as due to the action of humus acjds. 

See Zeitschr. prakt. Geol., 1907, p. 19. On the constitution of the clay silicates see 

H. Le Chatelier, Zeitschr. physikal. Chemie, vol: 1, p. 396, 1887.
THE DECOMPOSITION OF BOCKS. 417

as halloysite, cimolite, pyrophyllite, 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.

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. Ithas 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." W J McGee 6 compares laterite with 

the ferruginous clays and soils of the upper Mississippi, and F. R. 

Mallet c regards the iron ores associated with the basalts of Ulster 

as having a lateritic character. W. Maxwell,** describing the* red 

soils of the Hawaiian Islands, .which aire derived from lavas by 

the action of volcanic acids, points out their similarity to laterite. 

T. H. Holland c suggests that lateritization may be due, in part at 

least, to the activity of bacilli or other micro-organisms which could 

live in a warm climate but not in colder regions. J. Walther f and 

S. Passarge ° 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

°See. R. D. Oldham, Manuel of the Geology of India, .2d ed., pp. 348-370, 1893. 

P. Lake (Mem. Geol. Survey India, vol. 24, pt. 3, pp. 17-46, 1800) gives a good summary 

of earlier views upfin the origin of laterite. Another elaborate summary is presented 

by G. C.'Du Bois, Min. pet. Mitth., vol. 22, pp. 4-18, 1903.

6 Geol. Mag., 1880, p. 310.

0 Rec. Geol. Survey India, vol. 14, p. 139, 1881.

"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.

« Geol Mag., 1903, p. 59. . '

'Verhandl. Gesell. IDrdkunde, vol. 16, p. 318, 1889.

" Rept. Sixth Internal. Geog. Cong., London, 1895, p. 071.

"* 1:4399 Bul 1.330 OS 27
418 THE DATA OF GEOCHEMISTEY.

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.

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,0 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,c 

its usual parent is diabase; in the Hawaiian Islands it is formed from 

recent lavas.d There are a good many analyses of laterite, some of 

them relating to samples of known origin, others to detrital material. For example, Bauer gives these two analyses by K. Busz of laterite from the Seychelles:

Analyses of laterite.

SiO.,... ....................................... .............................,..s..... Ai2 o8 . ..............-........-................:..-............................--....

Fe203 -. --...--.---... ......................................-..-..........:..........

H2 0.. ..............................................................................

Granite 

laterite.

52.06

29 49

4.64

14.40

100,59

Diorite 

laterite.

3.88

49.89

20.11

25.98

<W */»/ U\J ftfi

If from these mixtures we deduct the silica as quartz, the remainder 

Avill. approximate to the general formula EO;JH3 , 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, A1CXH, and 

limonite, Fe^^O,,. 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.

"Mem. Geol. Survey India, vol. 24, pt. 3, p. 17, 1890. M. Mnclaren (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.

"Neues Jahrb., 1898, pt. 2, p. 192.

c Min. pet. Mitth., vol. 22, p. 1, 1908. Du Bois gives several analyses of laterite.

rf Maxwell, Lavas <ind Soils of the Hawaiian Islands. C. Klement (Min. pet. Mitth., 

vol. 8, p. 26, 1886) gives two analyses of laterite from the Congo River in West Africa.
THE DECOMPOSITION OF BOCKS. 419

From this, point of view the analyses of Indian laterite published 

by H. and F. J. Warth a are peculiarly instructive.' A represents 

gibbsite,.B a bauxite, and C, D, E, and F laterite, found in situ.

Analyses of yibltsite, bauxite', and laterite.

SiOj.... ..................................

AlaOg..... ................................

FeaOs-. ...................................

MgO .....................................

CaO ......................................

TiOo...... ................................

HoO. ................ .....................

A.

.....<.....

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

.1.3. 75

.35

OQ

26. 82

:ioo. oo

D.

0.37

40 QQ

26. '61

.86

4.45

23.88

' 100. 00

E.

10.52

.23

35.38

0,1 07

.'40

.10

19.00

100. 00

F.

0.90

56. 01

.20

.64

 1.59

14. 39

100. 00

The following analyses (G to J) represent cletrital laterites:

Analyses of detrital laterites.

Balance, identical with bauxite]

AljOs....................:...

MgO........................

CaO.........................

TiOj.........................

H20 ..................:......

G.

6.67

28.77

15.40

11. 50

.25

7.41

100.00

H.

4.53

50. 26

11. 86

28.99

.43

3.93

100.00

I,

so vi

17. 16

9.58

28.38

.01

5.34

100.00

J.-

24 39

20.22

47. 39

.38

.01

7.61

3.00. 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

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.** The French 

bauxites are found mostly associated with Cretaceous rocks,0 and they

°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. 1.8, p. 1.72, 1902, for a description 

of Indian gibbsite, and L. L. Fermor, Rec. Geol. Survey India, vol. 34, p. 167, 1906, on 

gibbsite and manganese-ores in laterite.

6 See T. L. Watson, Bull. No. 1-1, Geol. Survey Georgia, 1904, for a good summary of 

the literature of bauxite, and a bibliography.

" See H. Coquand, Bull. Soc. gc"ol. France. 2d ser., vol. 28. p. 98, 1870. Auge", idem, 

i!d ser., vol. 16, p. 345, 1880. F. Laur, Trims. Am. lust. Miu. Kng., vol. 24, p. 234, 1894.
420 THE DATA OF GEOCHEMISTRY.

have been interpreted by several writers as deposits from hot springs 

or other therm'al waters.* 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 thatcertain French bauxites rest upon corroded limestones gives a plausibility to Meunier's suggestion. This mode of occurrence, however, is 

not general.

In several German localities bauxite is found, like laterite, as a 

direct residue from the decomposition of basalt. 6 The bauxite in 

some cases shows the structure of the original rock. Auge c observed 

bauxite at one locality in Auvergne resting on gneiss and partly overlaid by basalt. In Ireland G. A. J. Cole* has described bauxite 

which'was apparently derived from rhyolite or rhyolitic ash, and onedecomposing 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," 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/ H. McCalley/ C. W.. 

Hayes,7' and T. L. Watson.' Spencer regards the bauxite as a deposit 

from lagoons, and calls attention to its evidently common genesis 

with ores of manganese and iron'. Hayes notes its association with

" See Coquand and Auge", as just cited; also S. Meunier, Compt. Rend., vol. 96, p. 

1737, 1883 ; Bull. Soc. ge"ol. France, 3d ser., vol. 17, p. 64, 1888. Auge" argues from an 

erroneous datum relative to supposed bauxite formed by geysers in the Yellowstone 

National Park. F. Parmentier (Compt. Rend., vol. 115, p. 125, 1892) has called attention to the occurrence of alumina in mineral waters.

"See A. Streng, Zeitschr. Deutsch. geol. Gesell., vol. 39, p. 621, 1887. A. Liebrich, 

Inaug. Diss., Zurich, 1891. T. Petersen, Ber. XXVI. Vers. Oberrhein. geol. Vereins, p. 

38, 1893. J: Lang, Ber. Deutsch. chem. Gesell., vol. 17, p. 2892, 1884. R. Delkeskamp, 

Zeitschr. prakt. Geol., 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 Szfideczky, Foldt. Kozl., vol. 35, p. 247, 1905.

c Loc. cit.

d Trans. Roy. Dublin Soc., 2d ser., vol. 6, p. 105, 1896.

" Trans. Manchester Geol. Soc., vol. 22, p. 458, 1894. 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. Blackwell, p. 525. The analyses show large admixtures of titanic 

oxide in the bauxite.-

f Geol. Survey Georgia, 1893, The Palaeozoic group, p. 214.

o Geol. Survey Alabama, 1897, pt. 2.

'' Sixteenth Ann. Rept. U. S. Geol. Survey, pt. 3, p. 547, 1895. See also Trans. Am. 

Inst. Min. Eng., 1894, p. 243.

' Bull. No. 11, Geol. Survey Georgia, 1904.
THE DECOMPOSITION OF ROCKS. 421

gibbsite, halloj'site, 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 ° 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,6 gives added 

emphasis to this suggestion. The alteration of rhyolite to a quartz - 

alunite and a quartz-diaspore rock in the Rosita Hills, Colorado, 

described by W. Cross," 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/* The latter

 species, it may be observed, was prepared synthetically by A. De 

Schulten,6 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. Williams/ »T. C.. 

Brainier/ and C. W. Hayes.ft 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 syenites 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 elaeo-

" Zeitschr. prakt. Geol., 1897, p. 212.

b Trims. Am. Inst. Min. Eng., vol. 24, p. 573, 1804.

" Seventeenth Ann. Kept. U. S. Geol. Survey, pt. 2, jx 314, 189C. A quartz-alunlte rock 

In California has heen described by H. W. Turner, Aui. .Tour. Sci., 4th ser., vol. 5, p. 424, 

.1.898. ' . .

"See W. B. Phillips and D. .Hancock, Jour. Am. Chem. Soc., vol. 20, p. 209, 1898. 

Admixtures of kaolin, halloysitc, and san$ were noted. See also Watson's bulletin, 

loc. cit, and A. E. Hunt, Trans. Am. Inst. Min. Eng., vol. 24, p. 855, 1894. 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, p. 453, 1902.

" Bull. Soc. Min., vol. 19, p. 157, 1896.

' Ann. Kept. Geol. Survey Arkansas, 1890, vol. 2, p. 124.

"Jour. Geol., vol. 5, p. 263, 1897. This review contains a bibliography of bauxite, and 

references to earlier papers by Branner.

A Twenty-first Ann. Kept. II. S. Geol. Survey, pt. 3, p. 435, 1901.
422 THE DATA OF GEOCHEMISTKY.

Lite and sodalite," and it is conceivable that the two last-named species may have been the parents of the bauxite here. Like the Geor- < 

gia 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 A12 03 .2H2 0, few samples of 

it have exactly that composition. It is usually intermediate between 

diaspore, A12O3 .H2 O, and gibbsite, A12O3 .3H2O; but is sometimes 

near one and sometimes near the other. It seems, in fact, to be a 

mixture of the two hydrates, but in an amorphous condition.6 When 

solutions of sodium aluminate are decomposed by carbon dioxide, 

only the trihydrate is throAvn down, at least so far as crystalline 

products have been observed. 0 The ordinary, precipitated, gelatinous hydroxide has the same composition, according to E. T. 

Alien ] d 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 G 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, espe-

« See S. J. Thugutt, Neues .Tahrb., Beil. Bd. 0, p. 609, 1895. Also W. C. Brogger, 

Zeitschr. Kryst. Min., vol. 10, p. 50, 1890.

* On the hydration of bauxite, see also H> Lienau, Chem. Zeitung, 1905, p. 1280; and 

T. H. Holland, Rec. Geol. Survey India, vol. 32, p. 175, 1905. Holland gives analyses, 

and in one of them the Ti02 reaches 12.21 per cent.

K See De Schulten, already cited. Also F. Russ, Zeitschr. anorg. Chemie, vol. 41, p. 216, 

1904, for recent experiments and a summary, of the work done by earlier investigators.

d Chem. News, vol. 82, p. 75, 1900. On this subject there is a voluminous literature, 

and the published data are very discordant.

« Rec. trav. chim,, vol. 7, p, 75, 1888. Zeitschr. anorg. Chemie, vol. 18, p. 132, 1898.
THE DECOMPOSITION OF KOCKS. 423

cially in the Tropics. T. Schlosing," on comparing French soils with 

soils from Madagascar, found the latter to contain much free alumina, while in France there appeared to be chiefly, if not exclusively, 

silicates. Similar observations were made by J. M. van Beinmelen * 

on volcanic soils from Java and Sumatra, in which free hydroxides 

of iron and aluminum are abundant; and W. Maxwell's study of 

.Plawaiian soils 0 leads to the same conclusions. In these cases the 

bauxite or laterite substance is diffused instead of being concentrated. 

It is therefore less easily recognized, but its nature is the same as if 

it were assembled or segregated in distinct beds.

Taking all of the evidence into account, it, seems clear that bauxite 

may be formed by more than one process. It occurs in place, like 

laterite, as a residue from the decomposition of rocks; it is found 

also, apparently, as a precipitate, and sometimes, like any. other product of disintegration, it is in beds which represent transported material. In the last instance it is contaminated by mixture with sand 

and clay. Even in its residual or primary occurrence, its 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. Saints-Claire Deville,'* is such 

a product of condensation; and it is foundj 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 cal- 

"cium 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 libsration of silica in a colloidal or finely divided form, which could dissolve readily in the 

organic matter or humus acids of the ground waters, and so be re-

"Compt. Rend., vol. 132, p. 1203, 1001. According to K. Glinka (Zeltschr. Kryst. 

Min., vol. 32, p. 79, 1900), kaolin commonly contains admixtures of aluminum hydroxide, 

sometimes as diaspore, sometimes apparently bauxite.

» Zeitschr. anorg. Chernie, vol. 42, p. 265, 1904.

c Lavas and Soils of the Hawaiian Islands.

 ' Ann. chirn. phys., 3d ser., vol. 61, p. 309, 1861. Deville also found vanadium in 

bauxite. See also the references to analyses of bauxite previously cited.
424 THE DATA OF GEOCHEMISTRY.

moved. The common occurrence of laterite, bauxite, and soils containing them, in tropical countries, may be partly accounted for in 

this way, for organic matter is there especially abundant, and its 

products of decomposition are conspicuous. 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,* studying the alteration of German basalts, 

supposes that carbonated waters first transform the aluminous silicates into hydrous compounds, from which, by alkaline solutions, 

the alumina is thrown down; that is, the process consists of two 

stages, an intermediate hydrated silicate being first formed. Kaolinite is such a silicate, but it is insoluble, and the change ends with 

its formation. Possibly halloysite, which has the composition of 

kaolinite plus water, but which is decomposed by. acids, is such an 

intermediate compound. The association of halloysite with the 

Georgia bauxite is suggestive of this possibility; but alternatives, 

such as the formation of zeolites, must also be taken into account. 

Any relatively soluble or unstable silicate of aluminum 6 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.0

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,'r arid the phenomenon has since been

a Zeitschr. Deutsch. geo). Gesell., vol. 56, Monatsb., p. 17, 1904.

6 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 point 

is one which needs careful investigation.

c See A. Liebrich, Zeitschr. prakt. Geol.,, 1895, p. 275.

" Jour. Roy. Agric. Soc. England, vol. 11, p. 813, 1850; vol. 13, p. 123, 1852.
THE DECOMPOSITION OF ROCKS. 425

studied by many observers. K. Warington" 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 Avere more easily absorbed. J. Lemberg's papers'' 

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 ° relate to changes of the same order. 

Saline solutions were made to act upon decomposed rocks and their 

changes in composition were observed.

Double decomposition, however, is not the only process to -be considered in this connection. Warington's experiments point directly 

to an absorption of colloids, namely, the colloidal hydroxides of iron 

and alumina. According to J. M. van Bemmelen,fZ those " hydrogels," 

as they are called, together with similar hydrogels of manganese and 

copper oxides, show a.-marked absorpti.ve power for salts of the alkalies amd 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 G 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 f as long ago as 1888, and advocated later by 

P. Rohland.*7 It has recently been developed more fully by A. S.

" Jour. Chein. Soc., vol. 21, p. 1, 1868.

'' See especially the memoir in Zeitschr. Deutsch. geol. Gesell., vol. 28, p. 519, 1876.

" Mitth. Gr. Badisch. geol. Landesanstalt, vol. 4,, p. 389, 1903 ; Zeitschr. anorg. Chemie, 

vol. 47, p. 1.51, 1905. The two papers cover the same ground in part, but aro. not absolutely identical. A later paper by Dittrich is in Mitth. Bad. Landesanstalt, vol. 5, p. 1, 

1907. See also ,.T. Dumont, Comp. Rend., vol. 142, p. 345, 190G, on the decomposition 

of potassium carbonate by clay, etc., and 0. Schreiner and G. H. Failyer, Bull. No. 32, 

Bureau of Soils, TJ. S. Dept. Agric., 1906, on the absorption of phosphoric acid and 

potash by soils. ' .

d Zeitschr. anorg. Chemie, vol. 23, p; 321, 1900. See especially pp. 358 and 3G4. An 

earlier paper by Van Bemmelen in Landw. Versuchs-Station., vol. 21, p. 135, should also 

be noted.

* Zeitschr. anorg. Chemie, vol. 42, p. 314, 1904.

f Chimie agricole, in Fremy's Encyclopedic chimique, p. 67./

" Zeitschr. anorg. Chemie, vol. 41, p. 325, 1904.
426 THE DATA OF GEOCHEMISTRY.

Cushman,a whose experiments upon tlie binding power of road-making materials are apparently conclusive^

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 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. ,.

' SAND.

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

"Bulls. No. 85, 1904, and No. 92, 1905, Bureau of Chemistry, U. S. Dept. Agric., and 

Trans. Am. Ceramic Soc., vol. 6, 1904. Cushraan cites several other authorities than 

those mentioned here.

6 See also F. E. Grout, Jour. Am. Chem. Soc., vol. 27, p.. 1037. 1905. 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 

appears in Centralbl. Min. Geol. Pal., 1906, p. 33. .
THE DECOMPOSITION 0.1? HOCKS. 427

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 species 

is well established. The Bagshot sands r.ear London contain, according to A. B. Dick,a 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 6 found magnetite, zircon, olivine, garnet, 

sphene, chromite, tourmaline, and corundum. J. Thoulet c 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 d discovered quartz, orthoclase, micas, 

chlorite, epidote, hornblende, actinolite, garnet, zircon, rutile, tourmaline, hematite, and altered pyrite. J. A. Phillips e found the red 

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 oi silica. Probably the most 

elaborate investigation of this general kind is that by J. W. Ketgers f 

on the dune sands of Holland. In these the principal minerals are 

quartz, garnet, augite, hornblende, tourmaline, epidote, staurolite, 

rutile, zircon, magnetite, ilmenite, orthoclase, c'alcite, and apatite. 

Subordinate species are plagioclase, mi.crocline, 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 Si(X 

Many sea and river sands consist of nearly pure quartz, pure enough 

to be used in glass making. The following analyses, by W. Mackie,ff 

represent sands of diverse origin from various points in Scotland.

» Geology of London, vol. 1, p. 523, 1880 ; Natu::e, vol. 86, p. 91, 1887.

6 Bull. Soc. min., vol. 1, p. 39, 1878.

<> Idem, vol. 4, p. 2G2, 1881.

(1 Min. pet. Mitth., vol. 7, p. 452, 1S8G. The list of minerals found by W. M. TTutohings 

(Geol. Mag., 1894, p. 300) in English lake sediments is very similar'to this.

« Quart. Tour. Geol. Soc., vol. 38, p. 110, 1882.

'Neues .Tahrb., 1890. vol. 1, p. 10; Rec. trav. chira., vol. 1.1, p. 109, 1892.

' Trans. Edinburgh Geol.. Soc., vol. 8, p. GO, 1901. On the mineralogical examination 

of sands see also C. H. Warren, Technology Quart., vol. .19, p. 31.7. 190G. For analyses 

of American glass sands see Bull. U. S. Geol. Survey No. 315, 1907, pp. 37G, 382.
428 THE DATA OF GEOCHEMISTRY.

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. BJown sand.

SiOj.. .....................................

AhOs. ....................................

FetOn. ....................................

YeO.. ....................................

MnO......... .....'............:..........

CaO... ...................................

MgO......................................

K2O.. ....................................

Na2O. ....................................

Ps06 . ...........:..........:..............

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

.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

(50

100. 43

E.

55.03

14.12

10.15

6.88

6.38

1.66

.87

4.55

99.64

F.

91 39

5. 44

.89

.16

1.19

. .70

.65

100.42

SILT.

Between sand and silt the difference is partly one of kind and 

partly one of degree. Silt consists of the finer particles of rock substance, which, by virtue of their lightness, are carried farthest by. 

streams. This difference is mechanical. On the chemical side sand 

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 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, Lehrb.: 

chern. phys. Geol., 2d ed., vol. 1, p. 498. Bischof gives other data also concerning 

Rhine 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, 1806, p. 259.

0 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. p. 469, 1855 : Phil. Trans., vol. 

148, p. 61, 1859. In Science, vol. 23, p. 364, 1906, there is an incomplete analysis by 

C. li. Stone of Mississippi silt.
THE DECOMPOSITION OF HOCKS. 429

BiO2 . ..........................................................

A1208 .. ........................................................

Fe203 . ........................................................

MnO........ ..................................................

Mg0. ..........................................................

K20 ...........................................................

Na2O ...........................................................

CaCOs- ............................... .................... ...

MgC03 ........ ...............................................

FeC03 ..... ...................................................

S03 . ...........................................................

H2O- ......................................................

H20+... ..................... .. ..'...........................

A.

50.14

4.77

2.69

.35

.34

.77

.55

.54

30. 76

1.24

5.20

1> .99

1.66

100.00

B.

45.02

7.83

9.16

.44

.32

(?)

(?)

24.08

6.32

i

f 4. 58

l>2.25

100.00

C.

49.67

11.98

11.73

.27

.88

1.29

.69

i

1 23. 21

99.72

D.

45.10

15.95

13.25

2.64

4.85

1 95

.85

.34

C.70

»8. 84

100. 47

" Loss on ignition. 6 Probably including alkalies.

The higher proportion of calcium carbonate in the silts of the 

upper Rhine and Danube is probably due to glacial mud produced 

by the grinding of limestones. The Nile mad 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" at approximately 812.500,000,000 pounds, or about 

370,000,000 metric tons. The Nile, according to A. Chelu," 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 oi 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.c 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 obscured Colloid substances also promote sedi-

" Kept, on Physics and Hydraulics of Mississippi River, p. 148, 1876.

"Le Nil, le Soudan, 1'Egypte, p. 177, 1891.

c For a table giving the amount of suspended sediment in sea water at various points, 

see J. Murray and R. Irvine, 1'roc. Roy. Soc. Edinburgh, vol. 18, p. 220, 1890-01. 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 0.0250 gram, and in the Red Sea it falls to 0.0006.

"See C. Schlosing, Compt. Rend., vol. 70, p. 1345, 1870; W. H. Brewer, Am. .Tour. 

Sci., 3d ser.,"vol. 29, p. 1, 1885; C. Barus, Bull. U. S. Geol. Survey No. 36, 1886; Barus 

and E. A. Schneider, Zeitschr. physikal Chemie, vol. 8, p. 285, 1891; W. Spring, Rec. 

trav. chim., vol. 19, p. 204, 1000, and G-. Bodllinder, Neues .Tahrb., 1903, pt. 2, p. 147. 

See also T. S. Hunt, Proc. Boston Soc. Nat. Hist., vol. 16, p. 302, 1874 ; W. Ramsay, 

Quart. Jour. Geol. Soc., vol. 32, p. 129, 1876; J. Jolly, Proc. Roy. Dublin Soc., vol. 9, 

p. 325, 1900; L. F. Vernon-Harcourt, Proc. Inst. Civ. Eng., vol. 142, p. 272, 1900; and 

J. Thoulet, Ann. mines, 8th scr., vol. 19, p. 5, 1891.
430 THE DATA OF GEOCHEMISTEY.

mentation, 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 a 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 

in bringing it about.

G:LACIA:L CLAY'S.

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 E. D. Salisbury & 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 

Riggs 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 G of bowlder clay from 

Scottish localities.

Analyses of clays.

(1) Residuary clays, dried at 100° :

A. From Dodgevilie, Wisconsin, 45 feet below surface. 

B. The same, SJ feet below surface. 

C. From Cobb, Wisconsin, 4| feet below surface. 

D. The same, 8£ feet below surface.

(2) Glacial or drift clays:

10, F. From Milwaukee. Dried at 100°. 

G, H. Scottish bowlder clays, Mackie.

« Bull. Acad. Belg., 8d ser., vol. 34, p. 578, 1897.

" Sixth Ann. Kept. U. S. Geol. Survey, pp. 249-250, 1885.

"Trans. Edinburgh Geol. Soc., vol. 8, p. 60, 1901. '
THE DECOMPOSITION OF BOCKS. 431

SiOz ..... ............................

Als03 . ................................

j^ggO't

FeO...... ...........................

MgO.................................

K>0...... ...........................

HaO...... ...........................

TiOs.... .............................

PsO...................................

MnO................................

COi..... ..............................

S03 . ..................................

Cl.......... .........................

A.

71.13

12. 50

5.52

.45

.38

.85

2.19

1.01

4. 63

.45

.02

.04

.43

19

100. 39

B.

49.59

18.64

17. 19

.27

.73

.93

.80

.93

10.40

.28

.03

.01

.30

.34

100. 50

C.

49. 13

20.08

11.04

.93

1.92

1.22

1 ^

1 CO

11.72

.13

.04

.06

.39

1.09

100. U8

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

18.76

.32

.13

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

79

66

2.08

a4.11

.14

99.84

H.

74.89

12.22

| 4.29

.07

1.58

1.06

2.64

«3. 21

"""."67

.17

100.20

"Loss on ignition. Must include C0» and organic matter.

In the two Wisconsin clays the carbonates represent magnesia.ii 

limestone. The Scottish clays had evidently a different parentage. 

Glacial clays often contain carbonates, which are rarely conspicuous 

in rock residues." 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.

" 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 oE Connecticut, Bull. No. 4, 1905, G. F. 

Loughlin ; New Jersey, 1878, G. H. Cook ; New .Te::sey, vol. C, 1904, II. Kles and II. B. 

Kiimmel; Maryland, vol. 4, pp. 208-508, Ries; Virginia, Bull. No. 11, 1906, Ries; West 

Virginia, vol. 3, 1905, G. 1'. Grimsley ; South Carolina, Bull. No. I, 4th ser., 1904, 10. 

Sloan; Georgia, Bull. No. (j A, 1898, G. E. Ladd; Alabama, Bull. No. (!, 1900, Ries; AVisconsin, Bull. No. 7, 1901, E. R. Bucklcy ; Missouri, vol. 11, 1806, H. A. Wheeler; Indiana, 

Twenty-ninth Ann. Kept., 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. Geological Survey No. 228, 

pp. 351-370. Ries, Sixteenth Ann. Rept. U. S. Gecl. Survey, pp. 554-574, 1895, gives a 

long table of analyses of American clays, and a general report by Ries forms Prof. Paper 

No. 11 of the*-Survey, 1903. Bull. TJ. 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 Cong. intermit, gdol., p. 73, 1897, on the soils of Russia, and by 

W. Frear and C. P. Beistle, Tour. Am. Chem. Soc., vol. 25, p. 5, 1903. Work by Schlosing and Aran Bemmelen on tropical soils has already been cited. W. Maxwell (Lavas and 

Soils of the Hawaiian Islands,' Honolulu, 1898) and A. B. Lyons (Am. .Tour. Sci., 4th 

ser., vol. 2, p. 42.1, .1.896) have also contributed to tt.is phase of the subject. On the constitution of arable soils see L. Cayeux, Ann. Soc. ge"ol. du Nord, vol. 34, p. 146, 1905. On 

the origin and nature of soils see N. S. Shaler, Twelfth Ann. Rept. II. S. Geol. Survey, pt. 

1, p. 219, 1891. On fuller's earth see T. W. Vaughan, Bull. U. S. Geol. Survey No. 213, 

p. 392, 1903, and T. T. Porter, Bull. No. 315, p. 268, 1907. On soils in general see E. W. 

Hilgard's treatise " Soils," published in 1906.
432 THE DATA OF GEOCHEMISTRY.

Analyses of residual clays.

A. Residual clay from so-called Trenton limestone, Lexington, Virginia. Analysis by 

R. B. Riggs. Described by 'I. C. Russell, Bull. U. S. Geol. Survey No. 52, 1889.°

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 . ...............................:....................................-

FeaOa- ................:..................................................

FeO. . .................:..........................._......................

MgO .....................................................................

CaO. .....................................................................

Na20 ....................................................................

 K2O. ........-...........-.-.........-..........-....-:.-.................

H2O......... ....................:.............. ........................ .

TiOj....... ..............................................................

PsOs....... ..............................................................

COs...... ................................................................

A.

43.07

25.07

15.16

.03

.63

1.20

2.50

1 12.98

100. 64

B.

55.90

19.92

7.30 ?Q

1.18

.50

.23

4.79

2.54

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

LOESS.

In its chemical composition 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,6 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 

Avinds, 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 ° the adobe of the Great 

Basin is formed essentially in this way, and the sediments deposited

0 Russell especially discusses the cause of t:ed coloration In clays. On this subject 

see also W. 0. Crosby, Am. Geologist, vol. 8, p. 72, 1891 ; and W. Spring, Rec. trav. 

chim., vol. 17, p. 202, 1898.

6 China, vol. 1, p. 74; Geol. Mag., 1882, p. 297. See also R. Pumpelly, Am. Jour. Sci., 

Ud ser., vol. 17, p. 133, 1879.

"Geol. Mag., 1889, pp. 289, 342.
THE DECOMPOSITION OF ROCKS. 433

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,* 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 & as a glacial silt, 

deposited along the margins of glaciers during the glacial period. 

W. F. Hume,c studying the Russian loess, described that also as 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 

1'USh of Water following a thaw. T. C. Chamberlin e is inclined to 

combine the various theories concerning loess, and to' regard it "as 

both glacial and eolian. Here again, ais 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 Muscatirie, Iowa, by J. S. 

Diller/ 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 K. B. Kiggs. Discussed by T. C. Chamberlin and R. D. Salisbury, Sixth Ann. Kept. U. S. Geol. Survey, p. 282, 1885. Samples 

dried at 100°.

E. Cheyenne, Wyoming.

F. Denver, Colorado.

G. Highland, Colorado. Analyses E to G by L. G. Bakins. Discussed by S. F. Emmons, Mon. U. S. Geol. Survey, vol. 27, p. 268, 1896, together with several other examples.

"Am. Jour. Sci., 4th ser., vol. 6, p. -290, 1898. Kdyes describes the dust storms of 

the Missouri Valley, in which great quantities of aerial sediments are carried from place 

to place.

"Eleventh Ann. Kept. U. S. Geol. Survey, pt. 1, pp. 291, 435, 1891. See also F. 

Leverett, Mon. U. S. Geol. Survey, vol. 38, pp. 153-184: , 1899, for an account of lowan 

loess. The loess of Colorado is described by S. F. Emnons in Mon. U. S. Geol. Survey, 

vol. 27, p. 263, 1896.

"Geol. Mag., 1892, p. 549.

d Quart. Jour. Geol. Soc., vol. 50, p. 472, 1894.

« Jour. Geol., vol. 5, p. 795, 1897. See also T. C. Chamberlin and R. D. Salisbury, 

Sixth Ann. Kept. U. S. Geol. Survey, p. 250, 1885.

A Bull. U. S. Geol. Survey No. 150, p. 65, 1898.

14399 Bull. 330 08 28
434 THE DATA OF GEOCHEMISTRY.

SiOs... ........................

AlsOa.. ......... ..............

FesOs....... ..............'....

FeO

MnO... ........................

MgO...........................

CaO............................

NazO......... .................

K2O........ ................ ...

H2O.. ..........................

TiOs........ ...................

PaO5 ... ........................ co^.. ..........................

SOs.. ................. ........ ci... ............................

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 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

,

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

1'j.

67.10

10.26

2.52

31

1.24

5.88

' 1.42

2.68

5.09

.11

3.67

100. 28

F:

13.51

3.74

1.02

1.09

2.29

1.70

3.14'

4.19

.45

100. 40

G.

fin 07

15. 67

5.22

.35

1.60

2.77

97

2.28

9.83

.19

.31

100. 16

Several other analyses of loess from the Ehine. Valley are given by 

G. Bischof/' They resemble the analysis of Ehine silt cited on page 

429, ante. 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. Foil Wingate, New Mexico. 

D. Humboldt, Nevada.

SiO2 . .........................................................

A12O 3 . .........................................................

FeaOs

MnO ..........................................................

MgO .....................:.....................................

CaO ..........................................................

Na2O ...........................................................

K20..... ......................................................

HjO...........-....-.-.-.------.------ -------------------

PsOe... .-.--- ....................'............. - ...-..-----.-

 CO!.................................'.. . . ... ...

S03 .. ............,..................................:..........

Cl......... ....................................................

A.

3.26-

1.09

2.75

38.94

1.67

.23

29.57

2.96

CO

.11

100. 35

B.

66.69

14. 16

4.38

09

2.49

.67

1.21

4.94

.29

.77

9 nn

.34

99.72

C.

26. 67

.91

.64

.51

36.40

trace

2.26

.75

25.84

c If)

89

.07

99.97

D.

13. 19

5. 12

.13

 ) Q(j

13. 91

 .59

1. 11

3.89

.94

8.55

3.43

.64

.14

99.84

The extremely variable but generally calcareous nature of these 

soils is sufficiently indicated. It is highly desirable that there should 

be some good analyses made of Chinese loess, for use in comparison 

with these. 6 If Eichthofen's theory of its origin is correct, it should 

contain much organic matter derived from the grasses which are supposed to aid in its accumulation. It is known to contain abundant 

carbonates, which may represent the unleached dust of limestones or

0 Lehrb. chem. phys. Geol., 2d ed., vol. 1, p. 504. See .also data given by J. Roth, 

Allgem. chem. Geol., vol. 1, p. 619. 

o An incomplete analysis of loess from the upper Wey-Ho Valley, by A. Schumacher, is 

given in .AVissenschaftliche Ergebnisse der Reise des Grafen Bgla Sze'chenyi in Ostasien, 

p. 387, Wien, 1899.
.THE DECOMPOSITION OF BOCKS. 435

in ay. have been introduced in solution by. waters brought up through 

capillary action from below.

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,0 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. 6

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 relative!}'; small amounts it is diffused 

through all parts of the ocean, but beyond a certain limit its influence 

is small. The yelloAv 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,0 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 clown in relatively shallow water. Glacial 

debris, 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 

Kenard d 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.

" See p. 99, ante.

» See J. Murray and A. Renard, Proc. Roy. Soc. Edinburgh, vol. 12, p. 474, 1883-34.

«R. Pumpelly, Am. Jour. Sci., 3d ser., vol. 17, p. 133, 1879.

A Challenger Kept., Deep-sea deposits, table on p. 248, 1891.
436 THE'DATA OF GEOCHEMISTRY.

Mewi depth and area covered Ity marine sediments.

Volcanic sand.....

Green mud ........

Pteropod ooze..... 

Globigerina ooze . .

Radiolarian oo/,e..

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

i 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 a of this work, together with the composition of 

the peculiar manganese and phosphatic nodules which are often 

found in great numbers in the deeper parts of the sea.

Analyses of 'marine sediments.

A. Red clay. ft Twenty-three analyses by ,T. S. Brazier are tabulated on page 108, 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 430.

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.

. .

Si02 . ...... .................. ....I........

A 1 n

Fe203 ...... ...............................

MgO............... ......................

Ca3Po08 ..................................

CaS04 ....................................

MgC03 - ....... ...........................

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

.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

" Chapter IV, pp. 100-106, ante.

* See also .1. B. Harrison and 'A. J. Tukes Brown, Quart. Jour. Geol. Soc., vol. 51, 

p. 313, 1895, for other analyses of red clay and oceanic oozes. 

c Contains silica, alumina and ferric oxide, not separated.
THE DECOMPOSITION OF BOOKS. 437

.G. Blue mud. Analysis, by J. S. Brazier, page 448. 

I-I. Red mud. Analysis by M. I-Iornung, 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 

at 110°. The soluble and insoluble portions are here united.

SiOa..... :..........................................

A1 8 03 ............................ ...................

Fe203 -----. - - - '.............................-...

MnOs. ........:.....................................

CaO ................................................ Mgo... .........:.....................:.............

Na2O ...............................................

KsO .................................................

CaCO;i ......................................:.......

Ca3P208 .............................................

CaS04 .............................:................

MgCO ..............................................

S03

C02 .. ...............................................

Cl ..................................................

G.

5. GO

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

 1.08

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

.27

.83

100.00

These analyses serve well enough to show the variable character 

of the oceanic sediments, but they are in several respects incomplete. 

In order to determine the composition of the oceanic clays more 

minutely, two analyses have been made in the laboratory of the 

United States Geological Survey upon material kindly furnished 

by Sir John Murray. The samples analyzed were composites of 

many individual specimens, brought together from all of the great 

oceans and collected partly by the Challenger and partly by other 

expeditions. The data are as follows, reduced to uniformity by rejection of sea salts, calcium carbonate, and hygroscopic water, and recalculation of the remainder to 100 per cent.
438 THE DATA OF GEOCHEMISTKY.

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 ........................................ ........................................

A1208 .. .............................................................................

Cr2O3 .............................................................. .................

Fe03 ...............................................................................

FeO... .......................................................:.....................

NiO, CoO. ..........................................................................

MnO.. .............................................................................

MnO» ..............................................................................

MgO ...............................................................................

CaO ......................:.........................................................

SrO ..............-..-................................:......................,......

BaO.. .............................................................................. K2 o... :.............................................................................

Na«0 ...............................................................................

V203 .. ...... :...............:........,..................:............................

Mo03 ...............................................................................

p n

S.................... -.............-........-...................................;...

CuO. . ..............................................................................

PbO............................................................ ....................

ZnO... ............................................................................

C....... ............................................................................

HoO........................ ........................................................

A.

54.48

.98

1^ 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 oceanography.* 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," 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,0' the sulphates contained in the Avater are also partly 

reduced by micro-organisms, which liberate hydrogen sulphide. A 

porticm of this gas is reoxidized, with some liberation .of sulphur; 

another part takes up iron from the sediments and forms abundant 

deposits of pyrites.

" See, for example, K. Nntterer, on Mediterranean muds, Monatsh. Chemle, vol. 14, 

p. 624, 1893; vol. 15, p. 530, 1894; also upon Red Sea deposits, idem, vol. 20, p. 1, 1899. 

L. Schmelck (Den Norske-Xordhavs Expedition, pt. 9) gives many analyses of marine 

clays. J.. Y. Buchanan (Proc. Roy. Soc. Edinburgh, vol. 18, p. 131, 1890-91) reports 

partial analyses of Mediterranean samples. A. and H. Strecker (Liebig's Annalen, vol. 

95, p. 177, 1855) described a peculiar mud known as ." gytje," from the Saudefjord, 

Norway. A later study of the same substance was published by E. Bodtker (Liebig's 

Annalen, vol. 302, p. 43, 1898).

'' Proc. Roy. Soc. Edinburgh, vol. 18, p. 17, 1890-91.

" Guide des excursions du Vll Gong, g£ol, internal., No. 29, p. G, 1897.
THE DECOMPOSITION OF ROCKS. 439

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,.Avhich, as J. Murray 

and R. Irvine*1 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 algoe 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,6 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.

GLATJCCXNTTE.

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 Renard," the shell is first filled with fine silt or mud, upon which 

the organic matter of the dead animal can act. Through intervention of the sulphates contained in the sea water, the iron of the mud 

is converted into sulphide, which oxidizes later to ferric hydroxide. 

At the same time alumina is removed from the sediments by solution and colloidal silica is liberated. The latter reacts upon the 

ferric hydroxide in presence of potassium salts extracted from adjacent minerals, and so glauconite is produced. This view is sustained 

by other evidence, namely, the constant association of the glauconite

°Proc. Roy. Soc. Edinburgh, vol. 18, p. 229, 1.890-91.

".Tour. Chem. Soc., vol. 15, p. 109, 1802.

c Challenger Kept., Deep-sea deposits, p. 383, 1891.
440 THE DATA OF GEOCHEMISTRY.

shells with the debris of^ rocks in which potassium-bearing minerals, 

such as orthoclase and muscovite, occur."

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'' has shown that in certain instances 

glauconite has formed subsequent to the consolidation of its rocky 

matrix, and while he admits that organic matter has assisted its 

development within shells, the mineral can be produced by some 

quite different process. What this process is he does not explain; 

he merely shows that glauconite can form without the intervention of 

organisms, and that its mode of genesis is at least twofold. Incidentally also he states that ferric hydroxide and pyrite are produced by 

the decomposition of glauconite, an observation which seems to indicate that the reactions predicated by Murray and Renard may be 

reversible.

The granules of glauconite from marine mud and from the sedimentary rocks,. although not found as definite crystals, have nevertheless a distinct cleavage, and are interpreted by A. Lacroix" as 

monoclinic and analogous to the micas. There is, however, another 

mineral, celadonite, Avhich 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 Giimbel fl and K. Glinka 0 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/ has been confounded with glauconite, although it isv free from potassium and its iron is practically 

all in the ferrous state. In glauconite the iron is mainly ferric, and-

" For other discussions relative to tbe origin of glauconite see C. W. von Giimbel, Sitzungsb. Akad. Miinchen. vol. 16, p. 417, 1886; vol. 26, p. 54",. 1806. .Also D. S. Caldcron, 

D. F. Chaves, and I', del Pulgar, An. Soc. espafi. hist, nat, vol. 23, p. 8, 1804. The'older 

literature of the subject is unimportant for present purposes.

h Contributions a 1'etude micrographique des terrains sedimentaires : Mem. Soc. geol. 

du Nord, vol. 4, pt. 2, pp. 163-184, 1897. " -

n Mineralogie de la France, vol. 1, p. 407, 1893-1895. Lacroix gives a number of 

analyses of French and Belgian glaueonites.

" Sitzungsb. Akad. Miinchen, vol. 26, p. 545, 1806.

" Zeitschr. Kryst. Min., vol. 30, p. 390, 1899. Abstract from a Russian original.

f Mon. TJ. S. Geol. Survey, vol. 43, p. 240, 1003. Leith gives a long table of glauconite 

analyses.
THE DECOMPOSITION OF ROCKS. 441

potassium is one of its essential constituents. According to the best 

analyses, glauconite probably has, when pure, the composition represented by the formula Fe'^KSioOo-aq., in which some iron is replaced by aluminum and other bases partly replace K> 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.''

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, p. 390, 1899), 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. Chern. Jour., vol. 14, p. 027, 1892. 8.22 per cent of the 

silica is stated separately as quartz.

D. Oceanic glauconite, mean of four analyses made by L. Sipocx, for Murray and 

Renard, Challenger Kept., Deep-sea deposits, p. 387, 1891.

B. Glauconite, Monte Brione, Lake Garda, Italy. Analysis by A. Schwager. Described 

by C. W. von Ciimbel, Sitzungsb. Akad. Miinchen. vol. 20, p. 545, 1890.

F. Celadoulte, Monte Baldo, near Verona, Italy. Analysis by Sclnvager. See Giirabel, 

loc. cit.

G. Celadonite, mean of four analyses of material from Scottish localities, by M. F. 

Heddle. Trans. Roy. Soc. Kdinburgh, vol. 29, p. 102, 1880.

AljOs-.... .....................

F.e203 ..........................

FeO ...........................

MnO ..........................

MgO................. ..........

CaO ...........................

Na20 ..........................

KsO ...........................

LisO. ..........................

H20 ...........................

TiO».......... .................

PsO&. ...........................

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. 85

C.

51.56

6.62

15.16

8.33

.95

.62

1.84

4.15

10.32

, 99. 55

D.

53. 6 L

9.60

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

.1.68

.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

.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

"See discussion by F. W. Clarke in Mon. U. S. Geol. Survey, vol. 48, p. 243, 1903. 

Compare L. W. Collet and G. W. Lee, Compt. Rend., vol. 142, p. 999, 1900.

''Many analyses of greensand marls are given by G. H. Cook, in Geology of New Jersey, pp. 414 e(:.sef|.. ISfiS. On New Jersey greensands see also W. B. Clark, Jour. Geol., 

vol. 2, p. 101, 1894. On Irish glauconite, see A. J. Hoskins, Geol. Mag., p. 317, 1895.
442 ' THE DATA OP GEOCHEMTSTKY.

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 a 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.

PHOSPHATE BOCK.

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,'' 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. 0

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.'1 R. Miiller c has

°Ann. Soc. ge"ol. du Nord, vol. 34, p. 146, 1905.

6 See ante, p. 292, and also the analyses of igneous rocks given in Chapter XT.

c For good summaries relative to the occurrence.of economically important phosphates 

of lime, see R. A. F. Penrose, Bull. U. S. Geol. Survey No. 46, 1888 ; A. Carnot, Ann. 

mines, 9th ser., vol. 10, p. 137, 1896 ; and E. Nivoit, in Fremy's Encyclopedic chimique, 

vol. 5, sec. 1, pt. 2, p. 83, 1884. All of these memoirs contain numerous analyses, and 

Penrose gives a bibliography of the subject down to 1888.

d See F. K. Cameron .and L. A. Hurst, .Tour. Am. Chein. Soc., vol. 26, p. 885, 1904, 

These writers give abundant literature references. See also Cameron and A. Seidell, 

idem, vol. 26, p. 1454, 1904 ; vol. 27, p. 1503, 1905. Earlier papers by S. P. Sharpies 

(Am. Tour. Sci., 3d ser., vol. 1, p. 171. 1871) and T. Schlosing (Coinpt. Rend., vol. 131, 

p. 149, 1900) may also be noticed.

".Fahrb. K.-k. geol. Reichsanstalt, vol. 27, Min. Mitth., p. 25, 1877. See also ante, p. 403.
. THE DECOMPOSITION OF KOCKS. , 443

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.ft C. L. Reese,6 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 Avhen the solution was 

allowed to stand over calcium carbonate. In presence of the carbonate, then, the phosphate would probably not be dissolved, while 

carbonate could pass into solution. Other salts in solution may assist 

or hinder the solubility of calcium phosphate, and since natural 

waters differ in composition the solvent process is necessarily variable. 

Cameron and Hurst,0 who studied the solution of iron, aluminum, 

and calcium phosphate, showed that the process is one of hydrolysis, 

the solution becoming acid,(Z and less soluble basic phosphates being 

left behind; that is, the solution contains acid ions, corresponding 

either to free acid or to acid salts a condition .which must materially 

affect the action of the liquid upon the substances with which it 

comes in contact. E,. Warington,6 for example, found that a solution of calcium phosphate in carbonated water was perfectly decomposed by Ivydroxides 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, Fe3PoO8 .SHoO, 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. Ij. Dudley f 

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 \vavellite, nscherite, variscite, turquois, callainite, peganite, sphserite, evansite, wardite, and zepharovichite. Most of these minerals are rare species, 

found in very few localities, and need no further consideration here.*' 

Aluminum phosphates are sometimes formed by the direct action 

of phosphatic solutions upon igneous-rocks, or even upon limestones

"Jour. Chem. Soc., vol. 78, pt. 2, p. 618, 1900. Abstract.

"Am. Jour. Sci., 3d ser., vol. 43, p. 402, 1892.

K Loc. cit.

d Apatite gives alkaline reactions. P. K. Cameron and A. Seldell, .Tour. Am. Chem. 

Soc., vol. 27, p. 1510, 1905.

" .Tour. Chem. Soc., vol. 19, p. 296, 1866.

' Am. .Four. Sci., 3d ser., vol. 40, p. 120, 1890.

" For details concerning these minerals, see Daua's System of. Mineralogy, and Its 

supplements. On the varieties of calcium phosphate known as osteolite and staffielite, 

see A. Schwautke, Centralbl. Min. Geol. Pal., 1905, p. 641.
444 THE DATA OF GEOCHEMISTRY.

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." The following compounds are the best 

known among them: . Monetite___________________HCaP04 . 

Brushite_____.____________-__HCaPO4 .2H2O.

Metabrushite____-___.._____________.2HCaP04.3H,O.

Martinite___________________2H2Ca5 (PO4 ) 4 .H3O.

Collophanite_________________CagPoOsJ-LO. 

Bobierrite ________________ ____ .Mg2P208.8H2O. .

Newberyite___________________.HMgPO4.3H2O.

Hannayite___________________ _____Mg3P2Os.2II2NH4PO4 .8H20.

,Struvite______________________NH4MgPO4 .6H2 0.

- Stercorite______________ ___ ___ T _ HNaNH4PO4 .4H2O.

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,?J 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. c found 

a phosphatized trachyte, the'alteration being clearly due to leachings 

from guano. A similar alteration of andesite was discovered by 

A. Lacroix d on Pearl Islet, off the coast of Martinique. In both 

cases feldspars furnished the alumina for the phosphate that was

0 On the phosphates found in the hat guano of the Skiptoh Caves, Australia, see 

R. W. B. Mclvor, Chem. News, vol. 55, p. 215, 1887; vol. 85, pp. 181, 217, 1902. 

Mclvor names three of the ammonium-magnesium phosphates dittmarite, muellerite, 

and schertelite.

b For the Navassa phosphate, see E. V. d'lnvilliers, Bull. Geol. Soc. America, vol. 2, 

p. 75, 1891. W. B. M. Davidson (Trans. Am. lust. Min. Eng., vol. 21, p. 139, 1892-93) 

thinks it may he a residual concentration from phosphatic limestone, and not a guano 

product. For Sombrero, see A. A. Julien, Am. Jour. Sci., 2d ser., vol. 3G, p. 424, 1S63. 

For Mona and Moneta, see C. U. Shepard,'jr., Am. Jour. Sci., 3d ser., vol. 23, p. 400, 

1882. See also S. Pi- Sharpies, Proc.'Boston Soc. Nat. Hist, vol. 22, p. 242, 1883. 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, 

p. 473, 1879) has described the deposits of phosphate on the island of Bonaire. N. H. 

Darton (Am. Jour. Sci., 3d ser., vol. 41, p. 102, 1891) and W. H. Ball and G. D. Harris 

(Bull. U. S. Geol." Survey No. 84, 1892) both 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, p. 407, 1893. On the Aruha phosphate see G. Hughes, 

Quart. Jour. Geol. Soc., vol. 41, p. 80, 1885.

"Quart. Jour. Geol. Soc., vol. 54, p. 230, 1898.

''Bull. Soc. min., vol. 28, p. 13, 1905. Lacroix (Compt. Rend, vol. 143, p. 601, 190G) 

has also reported an occurrence of phosphatized trachyte on the island of San Thomg, 

in the Gulf of Guinea. In this case, again, guano was the agent of alteration.
THE DECOMPOSITION OF ROCKS. 445

found. Another phosphate of similar character, from the island of 

Redonda, in the West Indies, was described by C. U. Shepard,*1 but 

nothing is said of its petrologic origin. Another example, analyzed by A. Andouar.d,6 came from the islet of Grand-Connetable, 

near the coast of French Guiana. All of these represent changes 

brought about by percolations from bird guano.

In the Minerva grotto, department of 1'Herault, France, A. Gautier ° found brushite, tribasic calcium phosphate, and a phosphate 

of aluminum to which he gave the name minervite. To this lie 

assigned the formula A12P2 0S .7H2 0, but his data seem to have been 

based on impure material. A later analysis by A. Camot rf 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 

true of a white, pulverulent substance described by J. C. H. Mingaye c 

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, TenII.

B. Martinique, analysis by Arsandaux.

C. Kedonda, Shepard.

D. Grand-Conne'table, Andouard. .

E. Minerva Grotto, Carnot. 

F. Oran, Carnot. 

G. Jenolan caves, Mingaye. 

H. Controne, Sicily, Casoria.'

PsOf,..-. .............................

A12 03 . ...............................

MgO.... .............................

CaO .................................

KjO.. ...............................

Na2O ................................

NH3 . ................................

F...................................

Cl. ..................................

S03 . .................................

COs... ...............................

HaO, 100°'. ...........................

H2 0, 180°. ...........................

H2O, 200°. ...........................

A.

38.5

25.9

7.4

\ 5.0

23.0

99.8

B.

41. 20

34.20

24.50

99.90

C.

43.20

14.40

.57

1.60

24.00

100.37

I).

39.10

25.59

8.03

1.40

.06

1.70

f/21.24

2

cn

99.62

K.

37.28

18.59

.83

.33

 1.40

8.28

.52

4.35

23.70

4 50

99.78

F.

35. 17

18. 18

.31

5.80'

.48

11.60

13.40

14.80

99.74

G.

40.83

20. 70

.20

9.01

1.12

9.50

18.19

99.55

H.

37.10

22.89

1. 17

8.04

.02

.61

.36

7.87

I l> 21. 29

'

 99. 35

« Am. Tour. Sci., 2d ser., vol. 47, p. 428, 1869. See also C. H. Hitchcock, Bull. Geol. 

Soc. America, vol. 2, p. 6, 1891.

» Compt. Rend., vol. 119, p. 1011, 1894.

K Ann. mines, 9th ser., vol. 5, p. 1, 1894. Compt. Rend., vol. 116, pp. 928, 1028, 1893.

"Ann. mines, 9th ser., vol. 8, p. 319, 1895. Compt. Rend., vol. 121, p., 152, 1895.

" Rec. Geol. Survey New South Wales, vol. 6, p. Ill, 1899. Mingaye gives analyses 

of several other phosphates found In these caverns.

f The substance named palmerite by B. Casorla (Zeitschr. Kryst. Min., vol. 42, p. 

87, 1906) from near Controne, Sicily, is probably Identical with minervite. It was 

found in n layer under bat guano.

"At 105°.

A Loss on ignition.
446 THE DATA OF GEOCHEMISTRY.

Although these analyses do not represent pure compounds, they 

yield approximations to simple formulae. A, B, and D are not far 

from variscite, A1P04 .2H2O. D suggests the analogous barrandite, 

(AlFe)P04 .2H2 0. Minervite, especially as shown in Mingaye's analysis, probably contains a salt of the composition H2KA12 (P04 ) 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/1 Avere 

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 

treated with ammonium phosphate, was converted into a salt of the 

composition Fe3 (PO4 ) 2 .6H2O; 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, 

Avhich 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. 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, 

Car,(PO4 ) 3F; but some varieties are more nearly the normal tricalcium phosphate, Ca3 (PO4 ) 2 . According to A. Carnot,& the concretionary phosphates are deficient in fluorine, while in the sedimentary 

forms it is present in nearly the apatite ratio. To apparently homogeneous broAvn grains from the chalk of Ciply, in Belgium, J. 

Ortlieb c assigned the formula 4CaO.2P2 05 .SiO.>, regarding the substance as a definite mineral species to Avhich he gave the name ciplyte. 

Probably hydrates of calcium phosphate, like collophanite, are also 

present in phosphorite beds. In an Algerian phosphate, G. Schiller d

"Ann. mines, 9th ser., vol. 5, p. 1, 1894. Compt. Rend., vol. 116, pp. 928, 1023,'1893.

6 Compt. Rend., vol. 114, p. 1003, 1892.

c Ann. Soc. geol. du Nord, vol. 16, p. 270, 1888-89.

d Zeitschr. angew. Chemie, 1898, p. 1101.
THE DECOMPOSITION OF ROCKS. 447

found chromium, to an average amount of 0.057 per cent of Cr2 0a . 

,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.'1 

Although bone is itself largely composed of calcium phosphate, fossil 

bones are not identical chemically with recent bones. The fossils 

show an enrichment in calcium carbonate, iron oxide, and fluorine, 

as A. Carnot 6 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; Triassicand

Cretaceous bones still more so; and in bones from Silurian and Devonian formations the ratio of fluoride to phosphate Avas 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.'-'

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.* 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.6 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

n See a table of 18 analyses by A. Engelhardt, Claus, P. Latschinow, and P. Kostycbevv 

In Revue de geologic, vol. 7, p. 320, 1867-68. The wood, bone, and cement; have practically the same composition.

6 Ann. mines, 9th ser., vol. 3, p. 155, 1893. In a dinosaurlan bone from Colorado, 

L. G. <Eakins, in the laboratory of the United States Geological Survey, found 2.12 per 

cent of fluorine.

c See F. Kuhlmann, Compt. Rend., vol. 75, p. 1678, 1872.

<l See discussion by L. Kruft, Neues Jahrb., Beil. Bd. 15, p. 1, 1902. This memoir 

relates to the distribution of phosphorite In the older Paleozoic formations of Europe.

" See J. Murray and A. P. Renard, Challenger Rept., Deep-sea deposits, pp. 397-400, 

1891. Also ante, in Chapter IV, p. 104,
448 THE DATA OF GEOCHEMISTRY.

greensand, associated with the glauconite which Avas laid doAvn at 

the same time. The replacement of calcareous shells by phosphat/ 

was clearly traced by A. F. Renard and J. Cornet ° in their study: - 

the Cretaceous phosphorites of Belgium.

The organic remains Avhich contribute to the formation of phosphorites vary AA7 idely 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 l 

found 85.79 per cent of calcium phosphate. The fossil casts of a gasteropod, Cyclora, are also, according to A. M. Miller,6' rich in phosphate. The Cambrian phosphates of Wales are regarded by H. 

Hicks d as derived in large part from crustaceans, a supposition Avhich 

is borne out by W. H. Hudleston's analyses.0 The shell of a giant 

trilobite contained 17.05 per cent of PX)5 ; the shell of a recent lobster 

yielded 3.26 per cent, and the average amount found in an entire 

lobster Avas 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, Avhen atmospheric agencies begin to Avork upon them. First, 

beds of phosphatic chalk or limestone are formed, from Avhich, by 

leaching Avith meteoric or subterranean Avaters, the excess of calcium 

carbonate is Avashed 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/ Avere thus derived from phosphatic chalk, from Avhich the 

calcareous shells have disappeared, Avhile the flints, siliceous sponges, 

and vertebrate bones are unchanged. According to Chateau-'7 the 

Eocene phosphates of Algeria Avere concentrated in the same Avay, 

from animal and vegetable debris laid doAvn in shalloAA7 salt-Avater 

lagoons. The beds also shoAv signs of local precipitation of phos-

"Bull. Acad. Belg., vol. 21, p. 126, 1891.

6 Am. Jour. Sci., 2d ser., vol. 17, p. 236, 1854.

< Am. Geologist, vol. 17, p. 74, 1896.

d Quart. Tour. Geol. Soc., vol. 31, p. 368, 1875. 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.

» Quart. Jour. Geol. Soc., vol. 31, p. 376, 1875.

'Idem, vol. 42, p. 325, 1886.

' Mem. Soc. inge"n. civils, August, 1897, p. 193. Analyses of Algerian phosphates, by 

H. and A. Malbot, are given in Compt. Rend., vol. 121, p. 442, 1895. The phosphorites 

of Tunis are described by P. Thomas in Bull. Soc. g6ol., 3d ser., vol. 19, p. 370, 1891. 

See also 0. Tietze, Zeitschr. prakt. Geol., 1907, p. 229, on the phosphates of Tunis and 

Algeria. Tietze gives numerous references to the literature of these deposits.
THE DECOMPOSITION OF ROCKS. 449

phates which had previously been dissolved. So long ago as 1870 

this theory of concentration by leaching was proposed by N. S. 

Shaler" to account for the nodular phosphates of South Carolina, 

and it seems to apply equally well to the other phosphorite deposits 

of the United States.

The phosphorites of Tennessee, which have been somewhat exhaustively studied,'' furnish an excellent illustration of the several processes, chemical and mechanical, which have taken part in their formation. As interpreted by Hayes and Ill-rich, 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 Avere 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,0 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.

°Proc. Boston Soc. Nat. Hist, vol. 13, p. 222, 1870, and also later In the Introduction 

t.o ll. 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, p. 

504, U. 8. Geol. Survey, 1888 ; 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. Kept., pt. 4, p. 610, 1895 ; Seventeenth Ann. Kept., pt. 2, p. 539, 1896; Twentieth: 

Ann. Kept., pt. 6, cont., p. 633, 1899 ; Twenty-first Ann. Kept., pt. 3, p. 473, 1901; and 

Bull. No. 213, p. 418, 1903. L. P. Brown, Nineteenth Ann. Kept., pt. 6, cont., p. 547, 

1898. E. C. Eckel, Bull. No. 213, p. 424, 1903. The latest discussion, by Hayes and 

E. 0. Ulrich, is given in Geologic Atlas U. S., folio 95, 1903. See also T. C. Meadows 

and L. Brown, Trans. Am. Inst. Min. Eng., vol. 24, p. 582, 1895 ; Hayes, idem, vol. 25, 

p. 19, 1896; J. M. Saffiord, Am. Geologist, vol. 18, p. 261, 1.896; and W.' B. Phillips, 

Eng. and Min. Jour., vol. 57, p. 417, 1894.

0 See J. C. Scanner, Trans. Am. Inst. Min. Eng., vol. 26, p. 580, 1896; also Branner 

arid J. F. Newsom, Bull. No. 74, Arkansas Agric. Exp. Sta. The Devonian black phosphates of the Pyrenees, described by D. Levat (Ann. mines, 9th ser., vol. 15, p. 4, 1899), 

are also comparable with those of Tennessee and Arkansas..

14399 Bull. 330 OS 29
450 THE DATA OF GEOCHEMISTRY.

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,0 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, hitherto unpublished, 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.

Analyses of Florida pliosphates.

A. From near Sunnyside, Taylor County.

B, C. From Luraville district, Suwanee County.

D. From Albion district, Levy County.

SiOs..... ......................................................

TiO»... ........................................................

AljOs... ..:...................................................

Fea03 . .............................:...........................

MgO. ..........................................................

KSO ........................................................... s<i&tO.... ...................................................... Pto,. .......................................................... coj.. ..........................................................

SO3 .. ........................ ..........:.......................

F... ...........................................................

HjO at 105°. ...................................................

A.

3.44

.13

1 40

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

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 97

7 fiO

101. 61 

.82

100.79 

.12

D.

10.51

.58

21.17

3.10

23.95

.15

j- .40

25.38

2.14

.15

1.42

1 97

10.35

100.57 

.60

99.97 

.22

NOTE. For other data on American phosphates, see R. A. F. Penrose, Bull. 

U. S. Geol. Survey No. 46, 1888, and also the following publications: Phosphates 

and marls of Alabama, E. A. Smith, Bull. No. 2, Geol. Survey Alabama, 1892; 

and W. C. Stubbs, Mineral Resources U. S. for 1883-84, p. 794, U. S. Geol. Survey, 1885. The Alabama localities yield phosphatic marls and greensands, of 

Cretaceous age. S. W. McCallie, Phosphates and marls of Georgia, Bull. No. 

5-A. Geol. Survey Georgia, 1896. D. T. Day, North Carolina phosphates. 

Mineral Resources U. S. for 1883-84, p. 788, U. S. Geol. Survey, 1885. M. C,

" Trans. Am. Inst. Min. Eng., vol. 21, p. 196, 1893. 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, pp. 36, 163, 423, 1896; also one by N. A. Pratt, in Eng. and Min. Jour., 

vol. 53, p. 380, 1892.
THE DECOMPOSITION OF ROCKS. 451

' Ihlseug, Phosphates of Juniata Counts', Pennsylvania, Seventeenth Ann. Rept.

U. S. Geol. Survey, pt. 3, p. 955, 1896. 

For phosphorite in Japan, see K. Tsuneto, Chein. Zeitung, vol. 23, pp. 800, 825,

1899. This phosphate occurs in Miocene sandstone, and contains some glauconite. Good analyses are given.

On phosphate rock in New Zealand, see A. R. Andrew, Trans. New Zealand

Inst, vol. 38, p. 447, 1905. On Christmas Island, Indian Ocean, E. W. Skeats, 

J Bull. Mus. Comp. Zool., vol. 42, p. 103, 1903. On nodules in eastern Thuriugia,

,T. Lender, Neues Jahrb., Beil. Bd. 22, p. 48, 1900. On French phosphates.

A. Nantier, - Compt. Rend., vol. 108, p. 1174, 1889; and H. Lasne, Bull. Soc. 

/ geol., 3d ser., vol. 18, p. 441, 1889-90.

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 ________ 2Fe2 03.H20. Contains 94.6 per cent Fe2 03.

Goethite ________ Fe2O3.H2O. Contains 89.9 per cent Fe2O3 .

Liinonite _______ 2Fe2 03.3H2 0. Contains 85.5 per cent Fe2 03.

Xanthosiderite ___ Fe2O8 -2H..O. Contains 81.6 per cent Fe,O3 .

Limnite _________ Fe2 03 .3H2 0. Contains 74.7 per cent Fe2O3 .

Of these only one, goethite, is crystalline; the others are amorphous, 

and all sorts of mixtures between them are likely to occur. They 

are also often admixed with siderite, FeC03 , which is itself an important ore of iron. Other impurities are sand, clay, calcium and mag-

.1 nesium 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." 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 aleady been partly indicated. Residual deposits may be formed, 

as in the case of laterite, or as represented by the gossan caps over 

bodies of sulphide ores. Great outcrops of such ores, especially of

j pyrite or chalcopyrite, are often altered to a considerable depth into 

masses of porous limonite. Pseudomorphs of limonite after pyrite 

are exceedingly common. When sulphides containing iron are thus

j oxidized, some- iron is removed in solution as sulphate, from which

0 See W. N. Hartley and H. Ramage, Jour. Chem. Soc., vol. 71, p. 533, 1896.
452 THE DATA OF GEOCHEMISTRY.

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 and humus 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, Avhich rises under a layer of ore at Ederveen, Netherlands, is 

cited by Van Bemmelen a 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 _ ___. _ _

Mg _ ._ ._

Fe _ _____ _

Mn _ __

K

Na

A1203 . . -

01- '_ _ . _ .

107. 6

_ __ 5.6

__ _ 19. 6

11.4

0. 9

10.0

______ 3.3

_ __ _ _ 15.2

SO4

H2 pa, __________

C03 ___ - .

SiO.. - -

Organic

0.9

_ 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 6 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,c 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 Avhere the air has 

free access limonite is produced. In muddy waters the silt goes down 

with the iron compounds, forming clay ironstone; and the black band 

ores of the coal measures represent what was once a carbonaceous 

mud/* In many cases the decomposition of ferrous carbonate solutions is effected or aided by the so-called " iron bacteria," which absorb

0 J. M. van Bemmelen, C. Hoitsema, and E. A. KlolDbie, Zeitschr. anorg. Cheinie., vol. 

22, p. 337, 1900. Analysis by G. Moll van Charante. The phosphoric acid of the water 

goes to the formation of vivianite.

"Text-book of Geology, 4th ed., p. 187.

c Tenth Ann. Kept. U. S. Geol. Survey, pt. 1, p. 305, 1890.

rf The literature of these ores is very abundant and voluminous. See especially F. M. 

Stapff, Zeitschr. Deutsch. geol. Gesell., vol. IS, p. 86, 1865; J. S. Newberry, School of 

Mines Quart., vol. 2, p. 1, 1880; H. Sjogren, Neues Jahrb., 1893, pt. 2, p. 273, ref.; J. H. 

L. Vogt, Zeitschr. prakt. Geol., 1894, p. 30, and 1895, p. 38; G. Reinders, Verhandel. 

Akad. Wet. Amsterdam, sec. 2, vol. 5, No. 5 ; A. Gaertner, Arch. Ver. Mecklenburg, vol. 

51, p. 73, 1897 ; and J. M. van Bemmelen, Zeitschr. anorg. Chemie, vol. 22, p. 313, 1900,
THE DECOMPOSITIO.N OF ROCKS. 453

the iron and redeposit it later as ferric hydroxide.* 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 6 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." 

Ferriferous limestones, 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 'll 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 precipitated hydroxides of iron vary much in character and 

appearance, and their exact chemical nature, despite the plausible 

formulae assigned to some of the minerals, is by no means clear. In 

color they range from yellow through various shades of brown and 

red, and in texture they differ as widely. ~J. M. van Bemmelen f 

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.0 According to P. Nicolardot,'1 however, whose inves0 See Van Bemmelen, loc. cit.; G. Tolomei, Zeitschr. anorg. Chemle, vol. 5, p. 102, 

1894 ; and authorities cited by C. R. Van Hise, Treatise on metamorphism : Mon. U. S. 

Geol. Survey, vol. 47, p. 826, 1904.

6 Ann. Rept. Geol. Survey Arkansas, 1892, vol. 1, p. 124. See also L. Cayeux, Compt. 

Rend., vol. 142, p. 895, 1906.

c See J. P. Klmball, Am. Jour. Sci., 3d ser., vol. 42, p. 231, 1891. See also C. W. 

Hayes, Trans. Am. Inst. Min. Eng., vol. 30, p. 403, 1900; Hayes and E. C. Eckel, Bull. 

U. S. Geol. Survey No. 213, p. 233, 1903; arid S.-'W. McCallie, Bull. No. 10A', Geol. 

Survey Georgia, p. 19, 1900, on the iron ores of that State.

" Am. .Tour. Sci., 3d ser., vol. 41, p. 28, 1891.

«Idem, vol. 43, p. 487, 1892.

f Rec. trav. chlm., vol. 7, p. 106, 1888; vol. 18, p. 86, 1899 ; Zeitschr. anorg. Chemle, 

vol. 20, p. 185, 1899; vol. 22, p. 313, 1900 ; vol. 42, p. 281, 1904. Also J. M. van Bemmelen and E A. Klobbie, Jour, prakt. Chemie, 2d ser., vol. 46, p. 529, 1892.

" See also W. Spring, Bull. Acad. Belg., 3d ser., vol. 34, p. 578, 1897, on the relations 

of humus to iron in natural waters, already cited on p. 430, ante. The same subject hns 

recently been discussed by O. Aschan, Zeitschr. prakt. Geol., vol. 15, p. 56, 1907.

h Ann. chim. phys., 8th ser., vol. 6, p. 334, 1905. Nicolardot cites many references to 

former Investigations upon the precipitated hydroxides. See also Otto Ruff, Ber. Deutsch. 

chem. Gesell., vol. 34, p. 3417, 1901.
454 THE DATA OF GEOCHEMISTRY.

tigation is most recent, ferric hydroxide exists in at least six modifications, Avhich 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 ferro.us carbonate, 

either crystalline or amorphous, or principally limonite with all sorts 

of admixtures of other substances. The following anatyses of bog 

ore, " raseneisenstein," from Ederveen, are given in the memoir by 

J. M. van Bemmelen, C. Hoitsema, and E. A. Klobbie.*1 These variations are shown iivore from a single locality, and the substances mentioned are mostly crystalline. The Fe2 03 represents the amorphous

variety.

Analyses of bog ore.

A. By G. Reinders. B. By E. A. Klobbie. C. By P. M. .Tiiger. D. By C. H. Kettner.

Fe2 08 . .........................................................

FeCO3 . ........................................................

MnCOs........ ................................................

CaC03 .........................................................

MgC03 . ................................:....;.................

Fe3 (P04 )2.. ...................................................

Fe'"P04 .......................................................

CaSO< .........................................................

KC1.................................................. ..........

NaCl....... ...................................................

H8 0 at 100° ..................................................

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

.82

50.02

.03

.95

1.12

100.32

C.

8.0

30.6

4.6

2.9

} 49.1

1.8

} 3.3

'

99.7

D.

36.49

6.12

2 Q1

.21

5.47

J.76

60

6.30

19. 30

1.20

12.10

4.00

 100.56

The subjoined analyses of limonitic bog iron from Mittagong, 

Australia, are cited by A. Liversidge.6 They are quite different from 

those shown in the preceding group.

Analyses of Australian bog ores.

Fe803 . .........................................................

AlsOs ..........................................................

MnO........ ..................................................

MgO.. ..........................................................

CaO ...........................................................

Si02 . ..........................................................

PsOs.. .........................................................

S03 ............................................................

E.

68.37

4.63

trace

14.10

trace

3.00

9.72

99.82

F.

57.61

24.30

6.41

trace

1.20

10.38

99.90

G.

74.71

3.04

.43

10.10

2.20

9.70

100. 18

H.

65.84

4.49

1.40

.48

14.27

.25

- .11

2.30

10.86

100. 00

"Zeitschr. anorg. Chemie, vol. 22, p. 319, 1900.

6 Minerals of New South Wales, p. 99. The analyses were made by the " government 

analyst."
THE DECOMPOSITION OF ROCKS. 455 

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," 

and similar nodular forms have been observed that were of recent 

terrestrial origin. May Thresh l discovered small hard black nodules 

resembling seeds in the bowlder clay of Essex, England; and similar 

bodies were found by W. M. Doherty c 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, Mn2 03 .H2 0, corresponds in type with goethite 

and diaspore; and hausmannite, Mn3 04 , is the equivalent of magnetite, although the two species are crystallographically unlike. Polianite and pyrolusite, two crystallized forms of the dioxide, MnO,,, are 

not matched by any compound of iron, and this oxide forms the 

chi^ef manganese ore. The hydrous psilomelane, of variable composition and uncertain constitution, is often associated with pyrolusite, 

and allied to it are many varieties which have received distinct names. 

These latter ores are amorphous,* 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, Crimora mine, Augusta County, Virginia. Analysis by J. L. Jarman, 

Am. Chem. Jour., vol. 11, p. 39, 1889!

B. Psilomelane, near Silver Cliff, Colorado.. Analysis by W. F. Hillebrand, Bull. U. S. 

Geol. Survey No. 220, p. 22, 1903. '

C. Psilomelane, Romaneche, France. Analysis by A. Gorgeu, Bull. Soc. min., vol. 13, 

p. 23, 1890. Partly recalculated from tbe original.

D. Wad. Rornaneche, France.. Analysis by Gorgeu," idem, p. 27. Partly recalculated.

a See p. 102, ante.

"Jour. Chem. Soc., vol. 82, pt. 2, ref. 567, 1902.

c Rept. Australasian Assoc. Adv. Sci., 1898, p. 339.

d According to A. Gorgeu (Bull. Soc. min., vol. 13, p. 27, 1890), the variety known as 

wad is sometimes crystallized.

" Gorgeu gives many analyses of natural oxides and hydroxides of manganese. See 

Bull. Soc. min., vol. 13, p. 21, 1890; vol. 16, pp. 96, 133, 1898. Also Bull. Soc. culm., 

3d ser., vol. 9, pp. 496, 650, 1893.
456 THE DATA OF GEOCHEMISTRY.

E. Varvicite, Austinville, Wythe County, Virginia. Analysis by P. H. Walker, Am. 

Chem. Jour., vol. 10, p. 41, 1880.

P. Lampadite, or lepidophaeite, Kamsdorf, Thuringia. Analysis by Jenkins, for A. 

Weisbach, Neues Jahrb., 1880, pt. 2, p. 109. This mineral shows exceptionally high 

hydration.

Mn02 . ......................................

MnO......................................

J?eaQa... ..................................

AljOs.....................................

PbO. .....................................

CuP. ......................................

NiO.. ....................................

CoO. ........................ . ...........

ZnO. .....................................

CaO.... ...................... ...........

.BaO................... '..... ...............

MgO......................................

KS 0. ......................... ...........

NasO.....................................

HiO-. ................... . .........

HS 0+. ...................................

Pj03 . .....................................

AaiO*,. ....................................

SbsOz.. ...................................

CaSO,... .................................

SiOj. .....................................

Insoluble .................... ... .....

A.

95.88

.62

.22

 .27

.09

.18

.23

1 2.08

.29

99.86

B.

76.18

5.71

.34

1.81

2.80.

.83

9Q

,3.46

.81

1.41

3.94

.12

2.30

100. 00

C.

66.88

8.22

1.45

[ .1.

.40

16.20

.20 } »

> 4. 65

1.50

.25

.15

100. 10

D.

Fid QS

7 97

| 1.10

3<V

1.65

15.45

.80

} 5.00

 .05

.60

4ft

.80

1.40

99.80

E.

68.86

7.51

| 2.23

14. 42

} 5.08

1.98

..........

100. 08

F.

58.77

9.59

| 21. 05

:

100."89

Asbolite is an earthy psilomelane containing much cobalt, which is 

a common impurity in manganese ores. Barium, as shown in the 

analyses, is also a frequent constituent of them. How far these 

admixtures can be ascribed to the formation of manganites, salts 

of manganous acid, is uncertain, but that is their common interpretation. f .

These sedimentary ores, and the similar ores produced by the alteration of manganiferous minerals, have diverse origins. F. R. Mallet a 

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,6 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. 0

«Rec. Geol. Survey India, vol. 12, p. 99, 1879; vol. 16, p. 116, 1883.

6 Am. Jour. Sci., 4th ser, vol. 12, p. 18, 1901.

C 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, p. 356, 1893. J. D. Weeks has reported on the manganese 

deposits of the United States in Mineral Resources U. S. for 1892, p. 171, U. S. Geol. 

Survey, 1893. T. L. Watson (Trans. Am. Inst. Min. Eng., vol. 34, p. 207, 1904) has 

described the manganese ores of Georgia. The manganese ore of Golconda, Nevada, which 

contains tungsten, is interpreted by Penrose (Jour. Geol., vol. 1, p. 275, 1893) 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, p. 250, 1894. See also J. H. L. Vogt, Zeitschr. 

prakt. Geol., 1906, p. 217, for an elaborate paper on bog manganese.
THE DECOMPOSITION OF ROCKS. 457

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, who has analyzed the deposits 

formed by the warm springs of Wiesbaden, the iron is precipitated 

first as ferric hydroxide. The manganese of the water remains in 

solution much longer as bicarbonate, and is finally laid down as carbonate as an impurity in calcareous sinter; that is, solutions of 

manganese carbonate are more stable than solutions of ferrous carbonate, and the manganese is therefore carried farther. A partial 

separation of the two metals, from the same solution, is thus effected.

The thermochemical arguments of L. Dieulafait 6 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 Dieulaf ait are as follows:

2FeO+O=Fe2 08+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+CO, =FeCO,+5.0 Cal.

MnO+C(X=MnC63+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, Fe.,O3 and MnO., 

will both be formed; but if they act slowly, in small quantities, the 

oxygen will go to produce Fe2 0n , and MnC03 can be generated at 

the same time. The manganese carbonate, being somewhat soluble, 

may then be separated from the ferric oxide by leaching,* either to 

be deposited as carbonate, or perhaps to be oxidized to MnO2 and 

C02 later.

"Cited by G. Bischof, Lehrlx chem. phys. Geol., 2d eel., vol. 1, p. 540. 

"Compt. Rend., vol. 101, pp. 609, 044, 67G, 1885.
458 THE DATA OP GEOCHEMISTBY.

In the last of Dieulafait's papers he gives the heat of formation 

of several manganese compounds:

Mn-f-S, 22.6 Gal.

Mn+0, 47.4 Cal.

Mn-fO+COo, 54.2 Cal.

Mn+02 , 58.1 Cal.

From these figures it appears that the dioxide is the most stable 

compound in the series; it is therefore the easiest formed, and is the 

principal manganese ore. The thermochemical and geological data 

are in complete harmony.

It is more than probable, as F. P. Dunnington a has shown, that 

manganese sulphate plays an important part in the separation of 

the two metals. He has proved, experimentally, that acid solutions 

of ferrous sulphate, such as are formed by the oxidation of pyrites, 

will dissolve manganese oxides to a very marked extent. At the 

same time ferric sulphate and ferric hydroxide, under favorable 

conditions, may also be formed. In contact with manganese carbonate, in presence of 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.

« Am. Jour. Sci., 3d ser., vol. 36, p. 175, 1888.
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."

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 

Avhich the waters can deposit in a relatively insoluble condition may 

serve as a cement. Such substances as silica, calcium carbonate, 

hydroxides of iron and aluminum, calcium sulphate, phosphate, and 

fluoride, barium sulphate, etc., fulfill this condition. Clay and bituminous substances also act as cementing materials. The additions 

thus made to a sand may be small in amount or even very large, sometimes equaling in quantity the cemented particles. Such an extreme 

case is furnished by the well-known Fontainebleau calcites, Avhich 

have crystallized around sand and contain sometimes 50 per cent of 

calcium carbonate. A. von Morlot & 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," 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

" On a classification of the sedimentary rocks, see A. W. Grabau, Am. Geologist, vol. 33, 

p. 228, 1904.

6 Haldinger's Berlchte, vol. 2, p. 107, 1846-47. 

0 Am. Jour. Scl., 4th ser., vol. 9, .p. 352, 1900.

459
460 THE DATA OF GEOCHEMISTRY.

perfectly developed. Gypsum crystals containing sand up to 48.58 

per cent have been found on the Astrakhan steppe, according to 

B. Doss,a who also mentions gypsiferous sandstones. 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. 6 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 C. R. Van Hise,c in a bed of sand of equal spherical grains, the 

minimum pore space amounts to 24 per cent, and the actual space 

is usually 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.** 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 sandstone from Lohne, Westphalia, by W. von der Marck,6 may illustrate 

the complexity of these mixtures.

a Zeitschr. Deutsch. geol. Gesell., vol. 49, p. 143, 1897.

"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, Proc., p. 46, 1880; A. A. Young, 

Am. Jour. Sci., 3d ser., vol. 24, p. 47, 1882 ; R. D. Irvlng and C. R. Van Hise, Bull. 

U. S. Geol. Survey No. 8, 1884; Irving, Fifth Ann. Rept. TJ. S. Geol. Survey, p. 218, 

1885. " Crystallized sands " from Peru are mentioned by L. Crosnier, Ann. mines, 5th 

ser., vol. 2, p. 5, 1852 ; and A. Daubree (fitudes synthe'tiques de geologic exp<?rimentale, 

pp. 226-230) cites a number of European examples.

0 Treatise on metamorphism: Mou. U. S. Geol. Survey, vol. 47, p. 863, 1904.

<* Calcium carbonate, up to nearly 30 per cent, is the cementing substance of the sandstone reefs found on the coast of Brazil. See the important monograph by J. C. Branner, which forms vol. 44 of the Bull. Mus. Comp. Zool., 1904. Branner mentions similar 

reefs in the Levant.

« Verhandl. Naturhist. Ver. preuss. Rheinlande u. Westphalens, vol. 12, p. 269, 1855. 

Many other similar analyses are given. G. Bischof (Lehrb. chem. phys. Geol., 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.
Soluble portion

SEDIMENTARY AND DETEITAL ROCKS. 461

Analysis of sandstone from Westphalia.

fCaC03 . . ............................... 39. 50

MgC03 . ...........................:.... 7.23

.............................. 7.54

3. 90

.82

T . .. ,. )Si02 ........ ........................... 36.65 Insoluble portion . . . . . A . 1 ^ . Q1 \xxi2\Jj( ....-..--.....-.............-..-..- . y JL

K20.................................. .03

HoO.................................. .62

99, 32;. '

In this analysis calcium phosphate appears among the cementing 

substances, and many ether examples of its occurrence under like conditions are known. Phosphatic sandstones from Perry County, Tennessee, have been described by C. W. Hayes,0 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 * found 13.GO per cent of P,05 , equivalent to 22.64 of Ca3P2 08 . 

In the same sandstone 4.98 per cent of calcium fluoride was also present. Calcium fluoride has also been reported by W. Mackie ° 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 d has described specimens containing from 

28.20 to 50.06 per cent of BaSO4 . 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." 

The barytic sandstones, so far as they have been described, are remarkably durable, because of the insoluble character of the cement. 

Calcareous sandstofies are easily disintegrated by weathering, for 

the carbonates are readily dissolved by atmospheric waters.

Apart from the cements, sandstones vary in composition exactly 

as do the sands. A sandstone may be nearly pure quartz, or quartz 

and feldspar, or micaceous, or glauconitic, and it can exhibit any 

texture from the finest to the coarsest. Textural differences, how-*

a Seventeenth Ann. Rept. U. S. Geol. Survey, pt. 2, pp. 527, 539, 1896.

» Jahresb. Chemie, 1852, p. 980.

<! Kept. Brit. Assoc. Adv. Sci., 1901, p. 649.

« Proc. Roy. Soc., vol. 46, p. 363, 1889; vol. 64, p. 374, 1899. See also W. Mackie, 

Rept. Brit. Assoc. Adv. Sci., 1901, p. 649; C. B. Wedd, Geol. Mag., 1899, p. 508; and 

C. C. Moore, Proc. Liverpool Geol. Soc., vol. 8, p. 241, 1898. Moore gives several good 

analyses of sandstones. In some of them small amounts of cobalt and nickel were 

found.

"See ante, p. 160. See also R. Delkeskamp, Notizbl. Ver. Erdkunde, 4th ser., Heft 21, 

p. 47, 1900. A. E: Reuss (Lotos, vol. 3, p. 72, 1853) has reported barite crystals inclosing much sand, and therefore analogous to the Fontainebleau calcites.
462 / THE DATA OF GEOCHEMTSTKY.

ever, 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.0 

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 Avhat is principally a chloride, 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 l> 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 ° to contain quartz, orthoclase, oligoclase, !- 

biotite, muscovite, hornblende, titanite, rutile, tourmaline, and apatite. 

In short, all of the rock-forming minerals which can in any way

a Described by W. S. Bayley in Bull. U. S. Geol. Survey No. 150, p. 84, 1898. Compare C. R. Van Hise, Am. Jour. Sci., ad ser., vol. 31, p. 453, 1886, for data concerning 

other similar rocks in the same region.

"Zeitschr. Deutsch. geol. Gesell., vol. 34, p. 771, 1882. , 

c Mon. U. S. Geol. Survey, vol. 13, JD. 59, 1888. Several other sandstones are V 

described by J. S. Diller in Bull. U. S. Geol. Survey No. 150, pp. 72-84, 1898.
SEDIMENTARY AND DETEITAL ROCKS. 463

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 following analyses, which, with one exception, were all made in 

the laboratory of the United States Geological Survey, will suffice to 

show the general composition of the sandstones: ft

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, p. 80, 1898. Nearly pure quartz.

B. Brown sandstone, Hummelstown, Pennsylvania. Analysis by Schneidei1 ; 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, p. 6, 1881. 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, p. 411, 1889. Made up of 

quartz, feldspar, pnd biotite, with a calcite cement. Contains also serpentine, titanite, 

magnetite, and zircon. 6

E. Miocene sandstone, Mount Diablo, California. Analyzed and described by W. H. 

Melville, Bull. Geol. Soc. America, vol. 2, p. 403, 1890.

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 II. N. Stokes. Described by W. S. 

Bayley, Bull. U. S. Geol. Survey No. 150, p. 84, 1898. Contains quartz, feldspars, iron 

oxides, and probably kaolin. In the cement are chlorite, quartz, magnetite, pyrite, 

rutlle, sometimes biotite, and either inuscovite or kaolin.

SiOs.................................

TiOj................... ..............

Alj03 ................................

JetOt.. ..............................

FeO .................................

MnO.... ............................

SrO.... .............................

MgO....... ..........................

Na2O ................................

KjO.. ...............................

LisO.................................

H.O-.. ...............................

HaO+.......... .....................

PS 06 . ................................

COj...... ............................

S02 ........... .......................

Cl. ..................................

A.

99.42

1 11 I ' 31

_

1 18 / - 18

99.91

B.

88.13

5.81

1.77

.31

.20

.53

.06

2.63

.23

.26

99.93

C.

49.81

5.17

29.17

.35

2.43

.95

.84

.48

3.85

6.56

.42

100.03

D.

48.13

.24

11.19

1.25

1.47

.29

16.39

.04

. 2.22

2.29

1.17

.78

1 758

.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.

78.06

.25

4.78

1.08

.30

5.52

.05

1.17

.45

1.32

.31

cl.33

.08

5.04

.07

100. 41

G.

84.86

.41

5.96

1.39

:84

1.05

.01

.52

.76

1.16

.27

cl. 47

.06

1.01

.09

99.86

H.

76.84

11.76

.55

2.88

.70

1.39

2.57

1.62

! 1.87

'

100.18

«For additional analyses, see Bull. U. S. Geol. Survey No. 228, pp. 291-296, 1904. 

W. Wallace (Proc. Phil. Soc. Glasgow, vol. 14, p. 22, 1883) and W. Mackie (Trans. 

Edinburgh Geol. Soc., vol. 8, pp. 58, 59, 1899) give a number of good analyses of Scottish sandstones. See also C. C. Moore, Proc. Liverpool Geol. Soc., vol. 8, p. 241, 1898, 

for English examples.

* Other " sandstone dikes" near Pikes Peak, Colorado, have been described by W. 

Cross. They probably represent quicksands which were injected into fissures.

c Includes organic matter.
464 THE DATA OF GEOCHEMISTRY.

A peculiar rock, which is sometimes called a calcareous sandstone, 

is the gaize of the French geologists. It has been fully described by 

L. Cayeux ° 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 

denned by Cayeux, a sedimentary rock consisting largely of nonclastic silica, and seems to have been originally a marine ooze.

FMNT 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. 6 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," 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,** studying chert 

from different localities, have argued in favor of the replacement

" Me"m. Soc. ggol. 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 

solution- depending upon the fineness of its subdivision, and the concentration of the 

alkali. Opaline silica, however, dissolves rapidly in weak alkali, and so can be roughly 

estimated. Quartz dissolves very slowly.

6 See Griswold's monograph on this rock (Kept. Arkansas Gfeol. Survey, 1890, vol. 3) 

and a paper by the same author in Proc. Boston Soc. Nat. Hist., vol. 26, p. 414, 1894. 

Compare also 0. A. Derby, Jour. Geol., vol. 6, p. 366, 1898; 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.

0 Quart. Jour. Geol. Soc., vol. 50, p. 380, 1894.

d E. Hull and E. T. Hardman, Sci. Trans. Roy. Dublin So'c., new ser., vol. 1, pp. 71, 85, 

1S7S, on the Carboniferous cherts of Ireland; A. Renard, Bull. Ac'ad. Belg., vol. 46, p. 

471, 1878, on the phthanites of Belgium; T. Rupert Jones, Proc. Ge01, Asspc. London, ' 

vol. 4, p. 439, 1876; and others.
SEDIMENTARY AND DETRITAL ROCKS. 465

theory. That the replacement of calcium carbonate by silica is possible, no one can deny, for silicified shells and corals ( are common. 

The pseudomorphs of chalcedony or opal after coral, from Tampa 

Bay, Florida, are conspicuous examples of this change. Furthermore, 

A. H. Church 0 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,6 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." Cherts crowded 

with these spicules have been described by various authors, especially by W. J. Sollas d and G. J. Hinde.6 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.^ 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 o 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 n the silica is simply a

0 .Tour. Chem. Soc., vol. 15, p. 107, 1862.

6 Lawson, Fifteenth Ann. Rept. U. S. Geol. Survey, p. 420, 1895; Lawson and Palache, 

Bull. Dept. Geology, Univ. California, vol. 2, pp. 354, 365, 1902 ; Ransome, idem, vol. 

1, p. 193, 1894.

c See Thoulet, Bull. Soc. min., vol. 7, p. 147, 1884.

" Ann. and Mag. Nat. Hist., 5th ser., vol. 6, pp. 384, 437, 1880 ; vol. 7, p. 141, 1881.

« Phil. Trans., vol. 176, p. 403, 1885; Geol. Mag., 1887, p. 435 ; idem, 1888, p. 24.1.

' See Hinde and Sollas, loc. cit, and G. C. Wallich, Quart. Jour. Geol. Soc., vol. 36, 

p. 68, 1880. ,T. A. Merrill (Bull. Mus. Comp. Zool., vol. 28, p. 1, 1895) has described 

fossil sponges from flints found in the Cretaceous near Austin, Texas.

o Proc. Am. Assoc. Adv. Sci., 1879, p. 396.

* See ante, p. 161.

. 14399 Bull. 330 08 30
466 THE DATA OF GEOCHEMISTRY.

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, 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.0 It is 

possible that a single formation may represent more than one of 

these processes. K. D. Irving and C. R. Van Hise,6 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: c

Analyses of chert and allied rocks.

A. Novaculite, Rockport, Arkansas. Analysis by R. N. Brackett. From Grlswold's 

monograph, p. 161.

B. Chert, Belleville, Missouri. Analysis by E. A. Schneider, Bull. TJ. S. Geol. Survey 

No. 228, p. 297, 1904. Other analyses are given on the same page.

C. Chert from the Upper Carboniferous of Ireland."1 Analysis by E. T. Hardman, Sci. 

Trans. Roy. Dublin Soc., new ser., vol. 1, p. 85, 1878.

D. Siliceous oolite, Center County, Pennsylvania. Analysis by Bergt, Abhandl. Gesell. 

I'sis, 1892, p. 115.

E. Infusorial earth, Nevada. Analysis by R. W. Woodward, Rept. U. S. Geol. Explor. 

40th Par., vol. 2, p. 768, 1877.

Si02 ................. ................................

Alj03 ......... ......................................

Fe2 03 . ..............................................

FeO.......... ......................................

CaO ...............................................:.

CaCOo........ ......................................

CaSO4 . ..............................................

MgO. ...............................................

KsO. ................................................

NasO ...............................................

P205 ...... ..........................................

\

A.

99.47

.17

.12

.09

.05

.07

.15

.12

100.24

B.

' 98.17

} .83

.

.05

.01

.78

99.84

C.

95.50

.10

1.95

.15

.87

trace

1.43

100.00

D.

98.72

1 |.5454 

.09

.26

 - ; '- -

99.95

E.

86.70

4 09

1.26

.14

.51

.41

.77

S

on

 99. 87

 ° E. H. Barbour and .T. Torrey, Am. Jour. Sci., 3d ser., vol. 40, p. 246, 1890 ; E. 0. 

Hovey, Bull. Geol. Soc. America, vol. 5, p. 627, 1893; and Bergt, Abhandl. Gesell. Isis, 

1892, p. 115. See also G. R. Wieland, Am. Jour. Sci., 4th ser., vol. 4, p. 262, 1897, 

who ascribes these oolites to the agency of hot springs.

"Tenth Ann. Rept. U. S. Geol. Survey, pt. 1, p. 397, 1890. See also C. R. Van Hise, 

Treatise on metamorphism : Mon. U. S. Geol. Survey, vol. 47, pp. 847-853, 1904.

c 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, p. 401, 1894, 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, p. 153, 1898) 

found appreciable amounts of phosphates ranging from 0.18 up to 3.5 per cent of P20s.

d Some of the Irish cherts are highly calcareous, representing transitions to siliceous 

limestone.
SEDIMENTARY AND DETRITAL ROCKS. 467

Other analyses, in considerable number, show intermediate gradations between chert and limestone. These represent comminglings 

in any proportion between the cherty silica and calcium carbonate, 

That is, silica and calcium carbonate may be deposited together in 

the same mud or ooze, forming a nearly homogeneous mixture.

SHALE AND SLATE.

When the finest products of sedimentation consolidate, they tend 

to form a close-grained, laminated, or fissile rock, which is called 

shale. As thus used, the term is very vague and has little chemical 

significance. Sand, reduced to the fineness of flour, may form a 

rock which is shaly in structure, and so too may limestone. In these 

cases, however, there is commonly more or less argillaceous impurity 

in the rocks, so that it is better to call them argillaceous sandstones 

or limestones.

As the term is generally used, a shale is supposed to be a consolidated mud or clay in which the aluminous silicates are the more 

important and characteristic constituents. Shales, therefore, vary in 

composition exactly as do the materials from which they form, and 

may contain sandy or calcareous impurities. Bituminous and carbonaceous shales are also common. Many shales contain pyrite or 

marcasite, which oxidize and give rise to the formation of sulphates. 

These rocks are called alum shales and exhibit aluminous efflorescences. The alum shales and calcareous shales are easily alterable; 

those which consist chiefly of aluminous silicates, having been formed 

from the final products of rock decomposition, are remarkably stable. 

Their disintegration, when it occurs, is largely a mechanical process 

and involves yery 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.0 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.

0 For data on the fineness of sand and mud particles, see C. R. Van Hise, Treatise on 

metamorphsm : Mon. U. S. Geol. Survey, vol. 47, p. 892, 1904.
468 THE DATA OF GEOCHEMISTKY.

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 No. 228, pages 337-350.

Analyses of shales. 

A. A composite analysis of fifty-one Paleozoic shales, by H. N. Stokes.

B. Composite analysis of twenty-seven Mesozoic and Ceriozoic 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, Bl.liott County, Kentucky. Analysis by T. M. Chatard.

H. Cretaceous shale, Mount Diablo, California. Highly calcareous. Analysis by 

W. H. Melville.

SiOj.... .............................

TiO>. ................................

A12 03 . ...............................

Fe^Oa. ......................... '......

FeO.. ...............................

MnO...... ..........................

ZnO. ................................

CaO. ...........;....................

BaO...... ................ ..........:

MgO........ .........................

NajO............. ...................

KjO.................................

Li2O .................................

'RtO...... ..........................

HjO-K. .............................

PsOs . ................................

COs..................................

S03 ... ...............................

s..... ...............................

C....................................

A.

60.15

.76

16.45

4.04

2.90

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

5.96

.06

2.67

1.80

2.67

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

.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

0.32

100.54

E.

51.03

13.47

8.06

.78

1.15

.41.

3.16

1 81 I - 81

.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

» Carbonaceous matter. 6 Less O=S, 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,
SEDIMENTARY AND DETRITAL ROCKS. 469

common in the sediments; but in the slates the feldspar grains have 

been more or less transformed into particles made up of interlocking 

quartz and mica; the latter usually appearing in the fibrous sericitic 

form. Even in Carboniferous clays and shales W. M. Hutchins 0 

found little kaolin, but more or less secondary quartz, chlorite, and 

mica. The chlorites, evidently, were derived from the debris of 

ferromagnesian minerals.

The mineralogical composition of the clay slates has been studied 

by several investigators," 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. Biitile, hematite, and tourmaline were also noted. The pyrite was often altered to limonite. 

Other Observers, stud/ing 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: c

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. P. Black slate, Slatington, Pennsylvania.

SiOs.. ....................................

A12 03 . ....................................

FeO... .............:.....................

MgO. .....................................

CaO.. ....................................

Na2 0. ...................................

K.O ......................................

H2 0- ....................................

HaO+....................................

Ti02 . .....................................

CO9 ..... ..................................

P2 09 . ......................................

MnO. .....................................

BaO ......................................

FeSa. .....................................

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

07

2.82

.48

7.42

.09

.30

.06

.03

100.38

F.

<;fi o.s

15. 27

1.67

3 93

4 91

1.30

3 51

.77

4 og

7ft

3.67

.17

09

.08

.1.72

KQ

100.39

" Geol. Mag., 1894, pp. 36, 64 ; idem, 1896, pp. 309, 343.

6 See especially W. M. Hutchins, loc. cit.; I-I. C. Sorby, Quart. Jour. Geol. Soc., vol. 36, 

Proc., pp. 66-80, 1880; F. A. Anger, Jahrb. K.-k. geol. Relchsanstalt, Mln. Mlttli., vol. 25, 

p. 162, 1875. T. N. Dale (Nineteenth Ann. Kept. U. S. Geol. Survey, pt. 3, pp. 153-307, 

1899; also Bull. No. 275, 1906) has made a special study of the roofing slates. His 

bulletin contains a report by W. P. Hillebrand on the composition of the slates, and 

closes with a valuable bibliography.

0 See Dale, loc. cit., who cites other analyses. Still others are given in Bull. U. S. 

Geol. Survey No. 228, pp. 337-346, 1904. J. Roth (Allgem. chem. Geol., vol. 2, p. 588) 

tabulates 15 analyses of European clays and shales, and H. Rosenbusch (Elements der 

Gesteinslehre, 2d ed., p. 442) gives a table of 19. See also E. C. Eckel, Jour. Geol., 

vol. 12, p. 25, 1904, for the average composition of 36 American roofing slates.
470 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 peculiarity is well shown |?y 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 the 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,6 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.0 Its variations in color 

and texture, to which its ornamental character is largely due, are 

commonly produced by impurities or inclusions, such as oxide of 

iron, or even mud and clay.

°Am. Jour. Sci., 4th ser., vol. 19, p. 345, 1905.

6 See ante,, p. 159. Analyses of tufa and travertine are given on p. 160.

c 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.
SBDIMENTABY AND DETRTTAL ROCKS. 471

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,0 in the delta of the Rhone, 

and B. Willis 6 has noted a similar precipitation of limestone along 

the margin of the Everglades in Florida. In the latter case, the 

inflowing water is exposed in broad, shallow sheets to evaporation, 

agitation, and variations of temperature and pressure. The calcium 

carbonate is partly thrown down as mud and partly deposited on 

underlying limestone as a layer of rock.

At Pyramid and Winnemucca lakes, in Nevada, great masses of 

calcareous tufa are formed, and sometimes, according to I. C. Kussell,c 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 d 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 e to the action of 

minute algae. This mode of formation needs to be considered further.

In 18C4 Ferdinand Cohn f studied the formation of travertine at 

the waterfalls of Tivoli. He found there that many aquatic plants, 

especially species of Chara, 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, tliey deprive that salt 

of its second molecule of carbonic acid, and the insoluble neutral carbonate is thrown down. The sinter or travertine is thus formed pri0 Principles of Geology, 12th ed., vol. 1, p. 426.

"Jour. Geol., vol. 1, p. 512, 1893.

" Mon. U. S. Geol. Survey, vol. 11, pp. 61, 189, 1885.

* Idem, vol. 1, p. 167, 1890.

"Am. Geologist, vol. 10, p. 279, 1892. See also E. B. Wethered, Quart. .Tour. Geol. 

Soc., vol. 51, p. 196, 1895, on oolite from other localities. Virlet d'Aoust (Compt. Rend., 

vol. 45, p. 865, 1857), 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. II. Weed (Ninth 

Ann. Kept. U. S. Geol. Survey, p. 613, 1889) has shown that the travertine formed 

around the hot springs of the Yellowstone National Park Is produced by the aid of alga.
472 . THE DATA OF GEOCHEMISTRY.

manly, but it is afterwards transformed into a compact mass by the 

deposition of calcite in its interstices; and in times of flood, when 

the waters are muddy, layers of sediment are laid down -with it.

The same sort of plant activity has been repeatedly observed in _ 

connection with the marl deposits of certain fresh-water lakes. The 

term " marl," it must be noted, is very vague, and has been applied not 

only to earthy forms of calcium carbonate, but also to glauconitic 

sands containing no carbonate at all. Shell marl, as its name indicates, is largely made up of fragmentary shells; the marl here mentioned is of a different kind. As long ago as 1854 W. Kitchell"5 

pointed out that Gliara took an active part in the production of fresh- > 

water marl. In 1900 C. A. Davis 6 discussed the subject much more 

fully, with reference to some lakes in Michigan, and came to essentially the same conclusions as Cohn. Davis, however, regards the 

oxygen liberated by the aquatic plants, Chara, etc., as assisting in 

some way the precipitation of the carbonate; but his equation showing the supposed reaction rests on no experimental basis. The activity of plants in marl formation was also considered by W. S. Blatchley and G. H. Ashley ° in their report on the lakes of Indiana, but 

these writers attach fully as much importance to inflowing, limebearing springs. The attention which these deposits have received 

is due to their value for fertilizing purposes. It is possible, as Mr. 

Bailey Willis has suggested to me, that some marine limestones have 

been formed by plant agencies. In the shallow seas which are 

thought to have covered a large part of the North American continent, , 

the calcium carbonate may well have been thrown down by algae. To 

produce a permanent deposit, however, the water must have been 

too warm to carry much carbonic acid in solution, and too shallow 

for the precipitate, while sinking, to redissolve.

Another process by which calcium carbonate may be precipitated 

was pointed out by G. Steinmann.d He found that albumen, which 

is present in the organic parts of all aquatic animals, was a distinct t 

precipitating agent. Apparently, by fermentation, the albuminoids 

generate ammonium carbonate, and to that compound the precipitation of calcium carbonate is due. This or any other alkaline car- ^ 

bonate, 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

0 First Ann. Kept. Geol. Survey New Jersey, p. 50, 1855. See also G. H. Cook, Geology 

of New Jersey, 1868, p. 172.

6 Jour. Geol., vol. 8, pp. 485, 498, 1900; vol. 9, p. 491, 1901.

"Twenty-fifth Ann. Kept. Dept. Geology, etc., Indiana, pp. 31-322, 1900. The memoir 

contains analyses of marls by W. A. Noyes. See also a criticism by C. E. Siebenthal, 

Jour. Geol., vol. 9, p. 354, 1901. 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, p. 288, 1889.
SEDIMENTARY AND DETRTTAL ROCKS. 473

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." 

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 Kelly,6 who named it conchite. The 

pisolite formed at the hot springs of Hammam-Meskoutine, Algeria, 

was given specific rank by A. Lacroix,0 under the name ktypeite. 

Both of these alleged species have since been identified with aragonite^ 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. 6 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 rin the 

cold, but becomes blue on long boiling. Again, calcite, in a solution 

of ferrous sulphate, produces a yellow precipitate of ferric hydroxide; 

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/ 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

" See the physicochemical researches of H. W. Foote (Zeitschr. physikfil. Cherale, vol. 

33, p. 740, 1900), in which this point is developed quantitatively. Important modern 

papers on the relations between calcite and aragonite are by I-I. Vater, Zeitschr. Kryst. 

Min., vol. 21, p. 433, 1893; vol. 22, p. 209, 1894 ; vol. 24, pp. 366, 378, 1895; vol. 27, 

p. 477, 1897 ; and vol. 30, pp. 295, 485, 1899. See also O. Miigge, Neues- Jahrb., Bell. 

Bd. 14, p. 246, 1901.

6 Mineralog. Mag., vol. 12, p. 363, 1900.

c Compt. Rend., vol. 126, p. 602^ 1898. For another description of this deposit see 

L. Duparc, Arch. sci. phys. nat, 3d *ser., vol. 20, p. 537, 1888.

d On conchite, see R. Brauns, Centralbl. Min. Geol. Pal., 1901, p. 134. H. Vater 

(Zeitschr. Kryst. Min., vol. 35, p. 149, 1902) examined both conchite and ktypeite. Vater 

also describes the Carlsbad " sprudelstein," which is aragonite.

« Ber. Oberrhein. geol. Verein, 1902, p. 31. See also Meigen, Centralbl. Min. Geol. Pal., 

1901, p. 577; A. Hutchinson, Mineralog. Mag., vol. 13, Proc., p. xxviii, 1903; and G. 

Wyrouboff, Bull. Soc. min., vol. 24, p. 371, 1901.

t Quart. Jour. Geol. Soc., vol. 35, Proc., p. 56, 1879.
474 THE DATA OF GEOCHEMISTRY.

fossils. The same subject was also discussed by V. Cornish and 

*P. F. Kendall ° 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 6 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 c 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 d 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 f has identified microscopic particles of quartz, zircon, tourmaline, rutile, magnetite, muscovite, orthoclase, plagioclase, anatase, 

brool^ite, 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 ^ has shown that all recent 

deposits, so far as he was able to examine them, were composed of 

aragonite, while the older " fossil " occurrences were calcite that is, 

according to his observations, oolite forms as aragonite and slowly - 

changes to the more stable calcite. By experimenting directly with 

sea water it was found that precipitation with sodium or ammonium 

carbonate produced aragonite, as determined by Meigen's reaction 

with cobalt nitrate. When solutions of calcium bicarbonate alone 

were allowed to evaporate, Linck further found that at ordinary 

atmospheric temperature calcite was deposited, but that at 60° 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

0 Geol. Mag., 1888, p. 66. 

b Rept. Brit. Assoc. Adv. Sci., 1896, p. 789. 

c Idem, 1896, p. 791.

« M6m. Soc. g ol. du Nord, vol. 4, pt. 2, p. 518, 1897.

0 See C. Wyville Thomson, Depths of the Sea, pp. 467, 501, London, 1874. 

'Op. cit, p. 257.

* Neues Jahrb., Bell. Bd. 16, p. 495. Linck gives a good summary of previous literature upon oolite.
SEDIMENTARY AND DETRITAL ROCKS. 475

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,0 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 hancL)( 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 froin different depths, but at the same 

locality, the gases Avere composed as follows:

Oases extracted from sea water collected at different depths.

0,.. ................................. ......................... X,... ........................................................

CO...... ....................................:................

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

40 V)

31.92

100.00

On the bottom, where the proportion of CO2 was highest, animal 

life was abundant, and the dredge brought up a rich haul. At 

another point, where the CO2 at the sea bottom fell .to Y.93 per cent, 

the dredge made a very bad haul. In short, from the composition

" See R. Bruuns, Chemlsche Mineralogie, pp. 377-378, for a summary of this subject.

6 In C. Wyville Thomson's Depths of the Se:i, pp. 502-511, London, 1874. On p. 513 

Is given a table of analyses of sea water by Frankland, in which the presence of abundant organic matter is shown.
476 THE DATA OP GEOCHEMISTRY.

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,ft limonite, deposited by a chalybeate 

spring, serves as cementing substance.

In the Bay of Naples, according to J. Walther,6 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, and the process may be followed step . by step. First, the 

living coral; then its dead fragments, broken into sand fey 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,6' 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, 

some earthy matter, and very small quantities of calcium phosphate. 

In corals from the Gulf Stream S. P. Sharpies d found from 95.37 

to 98.07 per cent of CaC03 , and 0.28 to 0.84 of Ca8P2 08 . These 

results are concordant with those obtained by many other analysts. 0 

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.

0 Am. Jour. Sci., 3d ser.,' vol. 34, p. 163, 1887.

"Zeitschr. Deutsch. geol. Gesell., vol. 37, p. 329, 1885.

"Bull. Mus. Comp. Zool., vol. 42, pp. 53-126, 1903.

"Am. Jour. Scl., 3d ser., vol. 1, p. 168, 1871.

" See, for example, A. Liversidge, Proc. Roy. Soc. New South Wales, vol. 14, p. 159, 

1880; 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, p. 224, 1891, on ' 

coral rocks from Barbadoes. A'number of analyses of coquina, coralline limestones, etc., 

are given in Bull. U. S. Geol. Survey No. 228, 1904.
SEDIMENTARY AND DETE1TAL ROCKS. 477

Ail; oceanic ooze may produce a soft, flourlike substance such as 

chalk, or a mixture of carbonate and sand, or one of carbonate, and 

mud or clay. Calcium carbonate, transported as a silt, may solidify 

to a very smooth, fine-grained rock, while shells and corals yield a 

coarse structure, full of angular fragments and visible/organic remains. Buried under other sediments, any of these rocks may be 

still further modified, the fossils becoming more or less obliterated, 

until in the extreme case of metamorphism a crystalline limestone 

is formed. All trace of organic origin has then vanished, a change 

which both heat and pressure have combined to bring about, aided 

perhaps by the traces of moisture from which few rocks are free. 

Several experimental investigations bear directly upo^n this class of 

transformations.

To illustrate the influence of pressure alone, we have an important 

experiment by W. Spring.0 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 b heated limestone in 

closed vessels and obtained from it a product identical in general 

character with crystalline marble. Since Hall's time the experiment 

has been repeated by a number of other investigators, under varying 

conditions, with various degrees of success, and with quite dissimilar 

interpretations. It was supposed at first that Hall had fused limestone, and this belief was prevalent for many years. G. Rose,0 

however, transformed a compact limestone into marble as Hall had 

done, but without evidence of fusion; and A. Becker,d 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.

"Zeitschr. anorg. Chemie, vol. 11, p. 160, 1896.

6 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 Rlchthofen, 

see .T. Leinberg, Zeitschr. Deutsch. geol. Gesell., vol. 24, pp. 237-241, 1872. Lemberg 

criticizes the conclusions drawn from Hall's data, and expresses a strong doubt as to 

whether fusion actually occurred.

< Pogg. Annalen, vol. 118, p. 565, 1863.

d Win. pet. Mitth., vol. 7, p. 122, 1886. Becker also gives a good summary of the 

earlier literature of the subject.
478 THE DATA OF GEOCHEMISTRY.

In the experiments of H. Le Chatelier ° 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 6 was able to transform 

chalk into something like marble at a temperature above the melting 

point of gold and under a pressure of 15 atmospheres. Joannis suggests that the melting point of calcium carbonate may perhaps be 

lowered by pressure. H. E. Boeke,c 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, H'eat alone, or 

both together. Actual fusion may or may not 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 

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 laboratoiy records of the United States Geological Survey: ll

" Compt. Rend., vol. 115, pp. 817, 1009, 1892. Two. papers.

o Idem, vol. 115, pp. "934, 1236, 1892. Two papers.

f Zeitschr. anorg. Chemie, vol. 50, p. 244, 1906. Boeke found that aragonite is 

transformed into calcite at 'about 470°.

" See Bull. No. 228, pp. 301-336, 1904, where 234 analyses of carbonate rocks are 

given. For other data see T. C. Hopkins, Ann. Kept. Geol. Survey Arkansas, 1890, vol. 

4. S. W. McCallie, Bull. No. i, Geol. Survey Georgia, 1894. 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, pp. 357-467, 1809. E. 0. Eckel, 

Bull. U. S. Geol. Survey No. 243, 1905, on cement materials. W. G. Miller, Rept. Bur. 

Mines (Ontario), 1904, pt. 2. T. C. Hopkins and C. E. Siebenthal, Twenty-first Ann. 

Rept. Dept. Geology, etc., Indiana, pp. 293-427, 1896.
SEDIMENTARY AND DETBITAL ROCKS. 479

Analyses of limestones.

A. Limestone, Lee, Massachusetts. Analysis by G. Steiger. 

B. Limestone, Sllverdale, 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. Coqulna, Key West, Florida. Analysis by F. W. Clarke. 

F. Recent coral (Siderostria), Bermuda. Analysis by L. G. Ealdns. 

G. Composite analysis, by H. N. Stokes, of 345 limestones.

IT. Composite analysis by Stokes of 498 limestones used for building purposes. Does 

the high proportion gf 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 CO^.

Ti02 . ................................

AljOj... .............................

FejOs................. ...............

FeO.. ...............................

MnO....~.......... .................

CaO .................................

MgO.................................

K2 0... ..............................

Na»0.. ...............................

Li2O .................................

HsO......... .......................

HjO-K. .............................

Pj05 . ................................

C02..... .............................

S... .................................

S03 . .................................

Cl.. .................................

;

A.

0.95

.09

.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

1 45 /

.26

53.80

.56

V .07

.23

.69

42.69

99.90

D.

a4.03

| .20

51.33

.72

> .63

| .83

 trace

41.07

.89

.27

99.97

E.

0.25

51.52

2.08

}. 3' 19

41.58

99.18

F.

0.23

55.16

.20

\

> .54

43.74

99.87

G.

5.19

.06

.81

}

.05

42.61

7 on

.33

.05

trace

.21

6.56

.04

41.58

.09

.05

.02

100.09

H.

14.09

.08

1.75

|

.03

40.60

4.49

.58

.62

trace

.30 6.88

.42

35.58

.07

.07

.01

100.34

Insoluble in hydrochloric acid. 6 Includes organic matter.

Limestones 'undergo alteration in several ways. They may be silicifie.d by percolating waters, or phosphatized, as is often seen on 

guano islands. Ity oxidation of inclosed pyrite, acid sulphates can 

be formed, and these will alter the limestone partially 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 ° 

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,

Bull. Geol. Soc. America, vol. G, p. 302, 1894.
480 THE DATA OF GEOCHEMISTRY.

etc.a 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,6 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,c the rate of 

limestone erosion in Spring Creek Valley, Center County, Pennsylvania, amounts to 275 tons per square mile per annum/ 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 necessary 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 0 obtained it by heating calcium carbonate with a 

solution of magnesium chloride to 200°, under a pressure of 15 atmospheres. J. Durocher f 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" 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,

0 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 Alahama as residues of this kind, but his 

views on that matter have been contested.

"Compt. Rend., vol. 118, p. 262, 1894.

e Am. Jour. Sci., 3d ser., vol. 29, p. 29, 1885.

a Or 29.173 grams per square meter.

* Cited in a memoir by A. Favre, Compt. Rend., vol. 28, p. 364, 1849.

t Idem, vol. 33, p. 64, 1851.

" Idem, vol. 47, p. 91, 1858-
SEDIMENTARY AND DETRITAL ROCKS. 481

and similar results were obtained with corals. A. von Morlot," 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 6 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 0 upon the precipitation of calcium and magnesium carbonates, especially by alkaline 

carbonates from bicarbonate solutions, are too complex to admit of 

anything like a full summary here. In most of the . experiments 

mixtures of calcium carbonate with the hydrated magnesium compound were obtained. When, however, the pasty mass formed by 

precipitating the two carbonates together was heated to temperatures 

above 120°, union took place and dolomite was formed. From the 

fact that a sedimentary dolomite could thus be produced, Hunt concluded that dolomite is generally a chemical precipitate, a view which 

is not widely held to-day.

In several instances the deposition of magnesian travertine and 

even of crystallized dolomite from natural waters'has been observed. 

According to J. Girardin,* the travertine formed by the mineral 

spring of St. Ally re, near Clermont, in France, is rich in magnesium 

carbonate. In recent travertine he found 28.80 per cent of MgCO3 

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 c 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/ 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 o found that springs

"Jahresb. Chemie, 1847-48, p. 1290. Also Compt. Rend., vol. 26, p. 311, 1848.

6 Kept. Brit. Assoc. Adv. Sci., 1856, p. 77.

e Am. Jour. Sci., 2d ser., vol. 28, pp. 170, 365, 1.859 ; vol. 42, p. 49, 1866.

* Ann. mines, 3d ser., vol. 11, p. 460, 1837.

0 Jahresb. Chemie, 1866, p. 178.

f Cited by L. Lartet, Bull. Soc. g6ol., 2d ser., vol. 23, p. 750, 1866.

' Liebig's Annalen, 8th Supp. Bd., p. 230, 1872.

14399 Bull. 330 OS 31
482 THE DATA OF GEOCHEMISTRY.

from the dolomites of the Jura, which contain calcium and magnr 

sium 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,ft Avhen artificial solutions of calcium and 

magnesium bicarbonate were allowed to evaporate spontaneously at 

ordinary temperatures. Only mixtures were formed, no dolomite. 

He also found that powdered chalk precipitated magnesium carbonate from a bicarbonate solution, although carbonated Avaters 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. 6 At ordinary temperatures a solution of magnesium chloride acting upor 

calcium carbonate for several months yielded no dolomite. Sea 

water mixed with an excess of calcium carbonate and saturated with 

carbon dioxide, after standing four months in a closed flask, also 

failed to form dolomite. But when magnesium salts or sea water 

were heated with calcium carbonate in sealed tubes, then both dolomite and magnesite were formed. Carbonate of lime, heated to over 

100° with a solution of magnesium bicarbonate, gave this result.

In the earlier researches upon the conversion of limestone into 

dolomite little or no attention seems to have been paid to the mineralogical character of the initial substance. In C. Klement's experiments ° 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 Avay. 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 MgCOs. 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 prob-

"Neues Jabrb., 1866, p. 1.

6 Zeitschr. Deutsch. geol. Gesell., vol. 27, p. 509, 1875. In this connection it may be 

noted that H. C. Sorby (Quart. .Tour. Geol. Soc.,'vol. 35, Proc., p. 56, 1879) found that 

Iceland spar, in a solution of magnesium chloride, became slowly incrusted with magnesium carbonate.

c Bull. Soc. beige geol., vol. 9, Mem. 3, 1895. Min. pot. Mitth., vol. 14, p. 526, 1894.
SEDIMENTAEY AND DETKITAL HOCKS. 483

 ably, ill time, recrystallize into the double salt. He attributes the 

i formation of dolomite to the action of sea water in closed lagoons

r

upon aragonite that is, upon coral rock. The latter, as will be 

y shown presently, is often the parent of dolomite. It must be observed, hoAvever, that aragonite is not the only parent of dolomite, 

for pseudomorphs of dolomite after calcite are well known.*

Two other investigations upon the synthesis of dolomite remain 

to be mentioned. L. Bourgeois' and H. Traube 6 obtained it by heating a solution of magnesium chloride, calcium chloride, and potas- 

; , slum cyanate, KCNO, to 130° in a sealed tube. This mode of pro- 

,_- duction has no geological significance, except in so far as it shows 

that the necessary carbonic acid may be supplied from organic or 

^ semiorganic sources. Such sources are considered by F. W. Pfaff,c 

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 a states that when a current of carbon 

^ dioxide is passed for a long time through a Avarm solution of the 

sulphates and chlorides of magnesium and calcium, the solution, upon 

sloAv evaporation at a temperature of 20° to 25°, yields a residue 

which contains a double carbonate insoluble in A\7 eak hydrochloric 

acid. That is, under these conditions, AA'hich might be approximately 

paralleled in the concentration of sea Avater, dolomite may be formed. 

Under certain exceptional conditions magnesium carbonate may 

be deposited alone. A solution of the bicarbonate, on evaporating 

spontaneously, forms the hydrous salt MgC03 .3H2 0, which corresponds to the rare mineral nesquehonite. This species, described 

by F. A. Genth and S. L. Penfield,6 from the Nesquehoning anthracite mine in Pennsylvania, Avas there produced by the alteration of a 

basic carbonate, lansfordite/ 3MgCO3 .Mg(OH) 2 .2lH,0, which first 

formed as stalactites in one of the galleries. Nesquehonite has since 

< been identified by C. Friedel^ as a similar formation in a French 

V coal mine. Such stalactiform minerals are obviously deposited from

solution in carbonated Avaters.

i' The term " dolomite " is sometimes loosely used by geologists as 

equivalent to maghesian limestone. Any limestone containing

a See Blum's Pseudomorpbosen, p. 51, and Nachtrag, p. 28.

"Bull. Soc. min., vol. 15, p. 13, 1802.

c Neues Jahrb., Beil. Bd. 9, p. 485, 1894. A later paper by Pfaff is published In vol. 

24, p. 529, 1907.

 "Centralbl. Min. Geol. Pal., 1903, p. 659. 

"' ° Am. Jour. Sci., 3d ser., vol. 39, p. 121, 1890.

t Described by Gentb, Zeitschr. Kryst. Min., vol. 14, p. 255, 1888.

"Bull. Soc. min., vol. 14, p. 60, 1891.
484 THE DATA OF GEOCHEMISTRY. .

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 limestones in general are likely to contain. In these rocks the ratio of 

lime to magnesia is greater than 1:1; but in computation it must 

be remembered that some dolomites contain iron, which replaces 

magnesia in equivalent amounts. Ferruginous dolomite, or ankerite, 

is not rare. All the iron of a carbonate rock, however, is not necessarily a part of the carbonate. It may be present as hydroxide or 

in claylike impurities, and these possibilities' must be taken into 

account in .any interpretation of the dolomites. In some cases free 

magnesian carbonates must also be considered, and in certain alteration products, brucite, Mg02H2 , may also occur. Commonly the 

dolomites are fairly simple in composition and difficulties in interpreting the analyses rarely arise.

In the study of natural dolomites as well as in the synthetic experiments which have just been described, it is of ten. 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.0 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

a Upon these differences in solubility, there is an abundant literature, which has heen 

well summarized hy A. Vesterberg, Bull. Geol. Inst. Upsala, vol. 5, p. 97, 1901; vol. 6, 

p. 254, 1905. See also the synthetic papers already cited, and Haushofer, Sitzungsb. 

Akad. Miinchen, vol. 11, p. 220, 1881.
SEDIMENTARY AND DETRITAL ROCKS. 485

described by J. Lemberg," whose reagent consists of a solution of 

aluminum chloride and hsematoxyliri (extract of logwood). This 

reagent deposits a violet coating upon calcite surfaces, but leaves 

dolomite uncolored. According to F. Cornu,6 the two minerals are 

easily distinguished by covering the powdered material with Avater 

and adding a few drops of phenolphthalein solution. Calcite gives 

a strong coloration; dolomite is affected but slightly.

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 ° 

described a "fresh-water dolomite" near Ulm, in Bavaria; 

and C. W. Giimbel/' studying the dolomites of the same region, which 

are interbedded with limestones, likewise asserts their sedimentary 

origin. T. Scheerer ° also argues that the oldest dolomites were 

formed as chemical precipitates; and T. Sterry Hunt's f 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. Forchhammertf 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 Lithothamnium nodosum 

Giimbel* found 2.66 per cent of MgO . and 47.14 of CaO; and 

Hogbom 7' in fourteen analyses of afgee belonging to this genus reports 

from 1.95 to 13.19 per cent of MgCO3 . To these higher figures reference will be made later.

" Zeitschr. Deutsch. geol. Gesell., vol. 40, p. 357, 1888. In vol. 39, p. 489, 1887, Lemlierg describes tests based upon the use of ferric chloride and ammonium sulphide. In a 

still earlier paper (op. cit, vol. 24, p. 226, 1872) Lemberg gives tests with silver nitrate, 

which stains calcite and dolomite, after ignition, unequally. See also Otto Meyer, 

Zeitschr. Deutsch. geol. Gesell., vol. 31, p. 445, 1879.

6 Centralbl. Min. Geol. Pal., 1906, p. 550. , '

0 Neues Jahrb., 1840, p. 371.

rt Sitzungsb. Akad. Miinghen, 1871, Heft 1, p. 45.

e Neues Jahrb., 1866, p. 1.

f See Chemical and Geological Essays, p. 80, and the literature already cited. .

» Neues Jahrb., 1852, p. 854.

ft Abhandl. Akad. Miinchen, vol. 11, p. 2G, 1871.

i 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.
486 THE DATA OF GEOCHEMISTRY.

 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 H6gbom,a show this fact very 

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 jean 6 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.0 Here the lime 

salt has dissolved much more freely than the magnesium compound. 

Hogbom also studied the marine marls of Sweden, and found that the 

transported material contained progressively larger proportions of 

magnesium carbonate, as its distance from the parent limestone 

increased. Near its point of origin the marl carried 3;7" parts of 

MgCO3 tc 100 of CaCO3 ; and from these figures the ratio was 

gradually raised to 36 MgC03 and 100 CaC03 . In these finely 

divided sediments the leaching out of calcium carbonate by atmospheric and glacial waters is naturally rapid, and the concentration 

of the dolomitic portion is effected with great ease. This mode of 

concentration, then, must be recognized as real, and as accounting 

in part at least for the formation of dolomite/ 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,e 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

«0p. cit., p. 267.

"Neues Jahrb., 1844, p. 543.

e 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, Lehrb. 

chem. phys. Geol., 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, p. 189, 1894.

e See Dana's Coral and Coral Islands, 3d ed., p. 393. Analyses by B. Silliman, jr. The 

island is called Metia by Dana.
SEDIMENTARY AND DETRT.TAL ROCKS. 487

cent, and the thought was at once suggested that the rock had been 

dolomitized by the introduction of magnesia from sea water, the 

latter having possibly been first concentrated by evaporation in a 

shallow lagoon.

Since Dana's observation was made, many other investigators 

have recorded similar enrichments of coral reefs, and the synthetic 

experiments of various chemists, as cited in the preceding pages, have 

shoAvn.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," reports 

6.95 per cent of magnesia, equivalent to 14.5 of carbonate, while the 

corals themselves contined 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 & rising to a maximum 

of 43.3 per cent of MgCO3 . 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. c

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.d 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 

MgCOs.

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

"Bull. Mus. Comp. Zool., vol. 44, p. 264, 1904. Analysis of rock by R. B. Swain, 

of the corals by L. R. Lenox.

"Idem, vol. 42, pp. 53-126, 1903.

c See R. Harkness, Quart. Tour. Geol. Soc., vol. 15, p. 103, 1859, on dolomite near Cork, 

Ireland. Also C. Doelter and R. lioernes, Jahrb. K.-k. geol. Reichsanstalt, vol. 25, p. 

293. These authors give a bibliography of dolomitization, down to 1875, the date of 

their memoir.

d The Atoll of Funafuti, published by the Royal Society, London, 1904. For .Tudd's report on the chemical examination, see pp. 362-389.
488 THE DATA OF GEQCHEMISTBY:

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 o.f lime salts, and the irregularities may be due in part to differences in the proportions of the various 

reef-forming organisms. Some of these are more soluble than others, 

as .we have already seen. Algae, especially Lithothamnion 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,0 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 6 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

0 Analyses made in the laboratory of the United States Geological Survey. Published 

in full in Bull. No. 228, p. 309, 1904. Boring described by E. 0. Hovey, Bull. Mus. 

Comp. Zool., vol. 28, p. 63, 1896.

"Mon. U. S. Geol. Survey, vol. 31, p. 206, 1898. 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.
SEDIMENTAKY AND DETKITAL BOCKS. 489

situated near magnesian eruptive rocks, dolomitization due to this 

cause is to be anticipated.

The following analyses of magnesian limestones were made in the 

laboratory of the United States Geological Survey." Other analyses 

in abundance are scattered through the literature of limestones.

Analyses of maynesian limestones.

A. Green Peak Quarry, Dorset, Vermont. Analysis by .George Steiger. Described by 

T. N. Dale in Bull. No. 195, 1002.

B. " Knox dolomite," Morrisville, Alabama. Analysis by W. P. 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. .1.9, 1892.

D. " Niobrara dolomite," Denver Basin, Colorado. Analysis by L. G. Baklns. Described by Emmous in Mon., vol. 27, 1896.

B. Near Red Mountain, Silver Peak district, Nevada. Analysis by Steiger.

F. The theoretical composition of ideally pure dolomite.

SiOs.. ....................................

A1203 ........ .............................

Fe2O3 .....................................

FeO.... ..................................

MnO.. ...................................

MgO........................... ........... do. .....................................

NasO. ....................................

K2 0. .....................................

HsO-. ....................................

H2O+ ....................................

C03 ...........:..... ......................

P205 . ................:....................

Cl. .......................................

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

4.r>.54

99.90

C.

0.63

.03

.75

.08

20.68

30.94

1 27 / >2/

46.27

99.65

D.

12.01

.54

.11

.20

18.03

27.49

I n r -- 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 Damour,6 G. Hauenschild,6 J. Koth,d and J. Lemberg,6 as a mixture of calcite and brucite, MgOL,H2 . 0. Lenecek/ however, regards 

it as a mixture of calcite and hydromagnesite, the latter being partly 

pseudomorphous after periclase and partly an infiltration. In either 

case the dolomite has been altered by the transformation of its magnesium carbonate into a basic salt or into hydroxide. The latter

n See Bull. No. 228, pp. 301-335, 1904, for these analyses and others.

b Bull. Soc. gfiol., 2d ser., vol. 4, p. 1050, 1847.

c Sltzungsb. Akad. Wien, vol. 60, p. 795, 1870.

d See Allgem. chern. Geol., vol. 1, pp. 422 425. Roth cites many analyses of altered 

dolomites, and gives the data concerning predazzite with considerable fullness.

a Zeitschr. Deutsch. geol. Gesell., vol 24, p. 187, 1874.

t Min. pet. Mitth., vol. 12, pp. 429, 447, 1892. LeneCek gives a good summary of the 

literature of predazzite.
490 THE DATA OF GEOCHEMISTEY.

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."

IRON CARBONATE.

Another important rock-building carbonate is siderite, the ferrous 

carbonate FeCO3 . Its formation as bog ore has already been considered,6 together with its transformation into limonite, but its relations to limestone and dolomite remain to be noticed. Between these 

rocks there are many transitional mixtures, and ankerite, the ferriferous dolomite, is one of them. This mineral contains iron replacing 

magnesium, to use the ordinary phraseology, but this implies that the 

double salt CaFeC2 00 exists isomorphous with and equivalent to 

the magnesian compound, dolomite. The two salts, CaFeC2 00 and 

CaMgC2 0G , 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, 

MnCO,, 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 ° found that Iceland spar 

immersed in a solution of ferrous chloride 1 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 d 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,6 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/ these ores were 

precipitated from solution by calcium carbonate, the iron first, zinc

a Arch. Naturkunde LIv., Esth. u. Kurlands, 1st ser., vol. 3, p. 142, 1864.

6 See ante, p. 452.

0 Quart. Jour. Geol. Soc., vol. 35, Proc., p. 73, 1879.

" Neues Jahrb., 1882, pt. 1, ref., p. 363.

 Am. Jour. Sci., 3d ser., vol. 42, p. 231, 1891.

'Compt. Rend., vol. 100, p. 662, 1885.
SEDIMENTABY AND DETEITAL ROCKS. 491

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,® the mosses form, from the Avater 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. 

SiO2 _.____ __ - - ______.________________ 1. 37

FeA _____________________________ 63. 03

Al-A ___'____________-__________ ______ .08

S03 ___________________________________________ 8. 35

H_O and organic matter______ __ __ ____ __ 20.94

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 6 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 sedimen1 ary origin. The process by which their concentration was probably 

effected has been summed up by C. R. Van Hise ° as follows: First, 

meteoric waters attacked the upper portions of the original carbonate, oxidizing the latter to limonite. In so doing the waters lost 

their dissolved oxygen and became carbonated. In this condition 

the waters dissolve ferrous carbonate, with some silicate,' and transfer 

it to lower levels. Later, the surface oxidation having been coma Am. Geologist, vol. 7, p. 48, 1891.

6 Canadian Naturalist, vol. 9, p. 431, 1.881.

" Twenty-first Ann. Kept. U. 'S. Geol. Survey, pt. 3, p. 326, 1900. 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 ,T. 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 deposits.
492 THE DATA OF GEOCHEMISTRY.

pleted, 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 0 to 

the associated siderite and limonite at Hiittenberg in Carinthia. In 

this case, however, the waters charged with ferrous carbonate redeposit it upon contact with limestones. Here also the original formation, the main ore body, is sedimentary. ^

The following analyses represent mixed carbonates, mainly 

ferriferous:

Analyses of mixed carbonates.

A. Iron carbonate, Sunday Lake, Michigan. Analysis by W. F. Hillebrand.

B. Iron carbonate, 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, pp. 318-320, 1904.

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. Bisenhuth, Zeitschr. Kryst. Min., 

vol. 35, p. 582, 1902. Other analyses of dolomite, etc., are given in this paper.

SiOa ......................................

TiOs........... ...........................

A12 03 . ....................................

Fe2 03 . .....:.............................-

FeO............................:.........

MnO ...:........................-.-.-....

CoO... ...................................

CaO ......................................

MgO. ............ ......... .................

HjO-... .................................

Psb

C0».. ........ .............................

SO3 ... ....................................

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

\ .68

30. 32

100.41

C.

23. 90

.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

8IIJCATED IRON ORES.

In addition to siderite, certain sedimentary silicates serve as sources 

for limonite and hematite ores. Glauconite, for example, was suggested by E,. A. F. Penrose 6 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.0 C. K. Leith,d however, in his 

report on the Mesabi district, has shown that the green mineral of 

the ferruginous cherts is not glauconite, but a hydra ted ferrous or 

ferroso-ferric silicate, containing no potassium. To this silicate he 

gives the name greenalite. Its composition, as shown by the anal0 Zeitschr. prakt. Geol., 1893, p. 301.

6 Ann. Rept. Geol. Survey Arkansas, vol. 1, 1892. This is a monograph on the iron 

ores of Arkansas.

c Bull. No. 10, Geol. Nat Hist. Survey Minnesota, 1894. 

"Mon. U. S. Geol. Survey, vol. .43, pp. 237-279, 1903.
SEDIMENTAKY AND DETEITAL BOOKS. 493

yses made by G. Steiger a 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 6 of a green, massive, chloritic 

mineral associated with the cronstedtite of Cornwall:

Analyses of greenalite, etc.

SiO,.... ......................................................

FejOs.... .....................................................

FeO.. ........................................................

H2O ..........................................................

Greenalite, Steiger.

1.

30.08 

34.85 

25.72 

9.35

mOO

2.

30.49 

23.52 

30.92 

9.07

100.00

3.

38.00 

8.40 

40. 50 

7.04

100.00

Cornwall, 

Field.

31. 72 

18. 51 

39.40 

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 .3H2 0. 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 glaucohite. 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 explanation thus offered to account for the iron-bearing rocks is probable 

enough to be provisionally held, at least until something better is 

offered. We know that ferruginous sediments are now forming in 

the ocean; we know that chert, in many cases, is of organic origin; 

and these facts are .consistent with the suppositions summarized above.

At a number of European localities iron ores are found which consist partly of silicates. One of these, thuringite, is a member of the

"See Leitb, op. cit., p. 246. Discussion by F. W. Clarke. 

* Phil. Mag., 5th ser., vol. 5, p. 52, 1878. .
494 THE DATA OF GEOCHEMISTKY.

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 a on Swiss material, and by E. R. Zalinski " onThuringian specimens, is represented by the empirical formula 

SFeO.ALO^SiCX.SI-LO. 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,0 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/ 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,6 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/

GYPSUM.

The occurrence of gypsum as a sedimentary rock has already been 

partially considered.*' 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

"Zeitschr. Kryst. Min., vol. 11, p. 601, 1886.

"Neues Jahrb., Beil. Bel. 19, p. 40, 1904.

0 See A. Lacroix, Mineralogie cle la France, vol. 1, p. 401, for this and other Frenchoccurrences.

d On the ores, locally known as "minette," 'of Luxemburg and Lorraine, see Bleicher, 

Bull. Soc. indust. de 1'Est, 1894 ; L. Hoffiman, Verhandl. Naturhist. Ver. preuss. Rheinland, etc., vol. 55, p. 109, 1898 ; 1-1. Ansel, Zeitschr. prakt. Geol., 1901, p. 81; and L. 

van Werveke, idem, p. 396. On the Thuringlan ores see H. Loretz, Jahrb. K. preuss. 

geol. Landesanstalt, 1884, p. 120. Much other literature is cited in the memoirs mentioned here.

" Neues Jahi-b., Beil. Bd. 19, p. 79, 1904. Zalinski gives a good summary of the various theories which have been framed in order to account for these ores.

f 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 1898. 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. 

Rept. of Progress F, Second Geol. Survey Pennsylvania, 1878, on the ores of the Juniata 

Valley. B. T. Bumble, Reports on the iron-ore district of East Texas: Second Ann. Rept. 

Texas Geol. Survey, 1891. The most exhaustive general treatise is R. Beck's great monograph, Die Geschichte .des Eisens.

" See ante, pp. 173-185.
SEDIMENTARY AND DETEITAL BOOKS. 495

origin,'1 or derived from the oxidation of pyrite, by acting upon 

limestones, also produce gypsum. Its appearance as an accessory 

mineral in dolomitization is due to double decomposition between 

limestone and solutions containing magnesium sulphate; and other 

sulphates may act in a similar way. L. Jowa,& 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.0

NATIVE SULPHITE.

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 

2H2S-|-02 =2H2 0-|-2S.<Z According to Becker, who studied the phenomena at Sulphur Bank, California, the oxidation of H2S to H2SO4 

develops 201,500 calories. The oxidation to H2 0+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 Eabbit Hole mines, Nevada, is also ascribed by G. I. Adams e to solfataric activity.

Sulphur deposits are common around mineral springs, being due 

to- the imperfect oxidation of hydrogen sulphide; and the latter compound may be generated, either by the action of acid waters upon 

sulphides, or through the reduction of sulphates, such as gypsum,

n .J. W. Dawson (Acadian Geology, p. 262, 1891) attributes the formation of gypsum 

in Nova Scotia to the action of sulphuric acid, derived from volcanic sources, on limestones.

6 Ann. Soc. ge"ol. Belg., vol. 23, p. cxxviii, 1896.

c For data upon American gypsum see G. P. Grimsley, Geol. Survey Michigan, vol. 9,' 

pt. 2, 1904; Grimsley and B. 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, p. 254, 1888; and J. Habermann, 

Zeitschr. anorg. Chemie, vol. 38, 1904; p. 101.

o Bull. U. S. Geol. Survey No. 225, p. 497, 1904.
496 THE DATA OF GEOCHEMISTRY.

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 

sedimentaiy formation not far removed from a center of great volcanic activity. The sulphur, therefore, has been regarded by some 

writers as volcanic, by others as a product of nonvolcanic agencies, 

and the conditions are such that either supposition can be strongly 

supported. Sicily abounds in solf ataras, and in springs charged with 

hydrogen sulphide; and these may well have brought the sulphur 

from volcanic sources far below the surface. Its deposition, in that 

case, is due to the decomposition of hydrogen sulphide, which has 

taken place under aqueous rather than igneous conditions; and this 

view, with differences in detail, has been adopted by various authorities.6 A. von Lasaulx,6 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 d 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. Bechamp,6 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/ but with fragments of marble 

and under a pressure of six atmospheres. The solution thus obtained 

was found to contain a sulphide, and upon evaporation to small 

bulk at ordinary temperatures it deposited microscopic crystals of 

calcite, sulphur, and gypsum. By a reaction of this kind, between 

the sedimentary limestones and the ascending sulphureted waters, 

the observed association of minerals may have been produced. 

Wherever such waters act slowly upon limestones free sulphur with 

gypsum is likely to be formed.*' It must be observed, however, that

a See especially E. Plauchud, Compt. Rend., vol. '84, p. 235, 1877 ; vol. 95, p. 1363, 

1882. Also A. Etnrd and.L. Olivier, idem, vol. 95, p. 846, 1882.

6 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.

c Neues Jahrb., 1879, p. 490.

A Sull' origine del solfo nei giacimenti solftferi 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, cit£d by Spezia, I have not been able to consult.

» Ann. chim. phys., 4th ser., vol. 16, p. 234, 1869.

1 Op. cit., p. 119.

0 Other examples are given by R. Brauns, Chemische Mineralogie, p. 366. L. Dieulafait (Compt. Rend., vol. 97, p. 51, 1883) has suggested that polysulphides of calcium 

and strontium may assist in the formation of sulphur deposits.
SEDIMENTARY AND DETKITAL KOCKS. 497

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 a 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 6 reports one water which carried 1,360 parts 

per million, or 79.08 grains per gallon, of free H.,S04 . The deposits 

are associated Avith 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 of limestone and shale, and gypsum is also abundant. 0 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,d 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 G has also reported celestite as extensively disseminated through dolomitic limestone near Syracuse, New York. At 

Put-in-Bay, Lake Erie, the limestones contain disseminated celestite, 

and caverns exist which are lined with crystals of that mineral.'

"Bull. Geol. lust. Upsala, vol. 1, No. 2, 1893. A similar inclusion was earlier described 

by 0. Silvestri, Gazz. chim. ital., vol. 12, p. 9, 1882.

11 Univ. Texas Mineral Survey, Bull. No. 2, 1902. See also G. B. Kichardson, idem. 

Bull. No. 9, p. 68, 1904. The sulphur deposits of Louisiana are described by L. Baldacci, 

II giacimento solflfero della Louisiana, Rome, 1906.

c See G. vora Rath, Neues Jahrb., 1884, pt. 1, p. 259. Vom Rath regards this deposit 

as of volcanic (or solfataric?) origin.

"Am. Jour. Sci., 4th ser., vol. 21, p. 237, 1900. See also W. IT. Sherzer, idem, 3d 

ser., vol. 50, p. 246, 1895 ; and Geol. Survey Michigan, vol. 7, pt. 1, p. 208, 1900,

"Am. Jour. Sci., 4th ser., vol. 18, p. 30, 1904.

/Kraus, Am. Jour. Sci., 4th ser., vol. 19, p. 286, 1905.

14399 Bull. 330 08 32
498 THE DATA OF GEOCHEMISTRY.

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,a celestite and barite 

occur together in bituminous limestone. H. Bauerman and C. Le 

Neve Foster 6 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.0 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, BaSO4 , is closely akin mineralogically 

to celestite, but is more characteristically found in metalliferous 

veins than in bedded formations/1 Its occurrence as a cement in 

sandstones has already been noticed," and it has also been observed 

as a sintery or even stalactitic deposit from spring and mine waters.^

P. P. Bedson o found barium to be present in notable amounts in 

an English colliery water; and T. Richardson 7t has described a 

deposit of barite from a similar solution. Like deposits from other 

English collieries have been reported by F. Clowes/ who analyzed 

samples containing from 81.37 to 93.35 per cent of BaSO4 . The 

pipes carrying water from the mines which yielded these sediments

were often choked by them, the barium sulphate being rarely absent 

and frequently their chief constituent. At Doughty Springs, in 

Delta County, Colorado, according to W. P. Headden,^' large masses 

of sinter have formed, consisting ,at some points of nearly pure barium sulphate, which at other points is mixed with minor to dominant 

quantities of calcium carbonate. 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.7" In this

" : 

«Min. pet. Mitth., vol. 9, p. 416, 1888.

6 Quart. Jour. Geol. Soc., vol. 25, p. 40, 1869.

0 Ann. mines, 7th ser., vol. 20, p. 557, 1881.

d See L. Dieulafait, Compt. Rend., vol. 97, p. 51, 1883.

" See ante, p. 461. .

f For the distribution of barium in waters, etc., see K. Delkeskarnp, Notizbl. Ver. 

Erdkunde, 4th ser.,'Heft 21, pp. 47-83, 1900. On the distribution of barium and strontium in sedimentary rocks, see L. Collot, Compt. Rend., vol. 141, p. 832, 1905.

"Jour. Soc. Chem. Ind., vol. 6, p. 712, 1887.

ft Rept. Brit. Assoc., 1863, p. 54.

* Proc. Roy. Soc., vol. 46, p. 368, 1889. 

i Proc. Colorado Sci. Soc., vol. 8, p. 1, 1905.

fc Jahrb. K. preuss. geol. Landesanstalt, 1888, p. 259.
SEDIMENTAKY AND DETRITAL ROCKS. 499

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 spriny and mine 'waters at Lautenthal.

BaCIj... ............................................................................

SrCIa......... .............................-......................"..................

CaCh..... ...... .....................................................................

MgCls......... ......................................................................

NaCl ...............................................................................

KC1 ................................................................................

MgSO<... ...........................................................................

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.0

Barln.ni and strontium sulphates in deposits at Lautenthal.

BaSO4 .........................................................

SrS04 ..... .....................................................

White stalactites.

84.81

12.04

Brown 

stalactites.

83.88

8.64

Mud.

82.3

13.4

Crusts.

92. 44

4.32

Similar mixtures of the two sulphates intermediate between barite 

and celestite are well known in crystalline form, and calcium sulphate 

is often present also. A remarkable banded barite, from Pettis 

County, Missouri, described by C. Luedeking and H. A. Wheeler,2* 

had the following composition:

Analysis of laritv frovi, Pettis County, Missouri. 

BnSO, ___- -_______________.________________ 87.2

SrSO, _______________________-___ _ - 10. 9 

CaS04 ____________________________________ . 2

(NH4 ) 2SO4 _______________________________________ . 2

I-LO _____________________ -__ ______ 2/4

100.9

The presence of an ammonium salt in such a miiieral 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

" Complete analyses are given in the original memoir by Lattermauu. 

"Am. Jour. Sci., 3d ser., vol. 42, p. 495, 1$91. The presence of ammonium salts was 

independently, verified by tests in the laboratory of the United States Geological Survey.
500 THE DATA OF GEOCHEMISTRY.

C. W. Dickson a 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 pjaite; 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 Avhich 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 l 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 ma'gmatically incompatible.

FLTJORITE.

Fluorite or fluor spar, calcium fluoride, CaF2 , is also a common 

mineral in dolomites and limestones,0 and it is often associated with 

galena and zinc blende. Crystals of.it are found in limestone geodes, 

where it has evidently been deposited from solution. In some cases 

it may have been formed by fluoride solutions percolating'through 

and replacing limestone. Its commonest occurrence is as a filling 

of veins.*

a School of Mines Quart., vol. 23, p. 366, 1902.

"Rec. Geol. Survey, India, vol. 30, p. 236, 1897.

c See ante, p. 273, for an account of fluorite as a rock-forming mineral. Also p. 461 

for fluorite as a cement in sandstones.

d For a description of the great fluor spar deposits in Kentucky and southern Illinois, 

see S. F. Bmmons, Trans. Am. Inst. Min. Eng., vol. 21, p. 31, 1893 ; H. F. Bain, Bull. 

U. S. Geol. Survey No. 255, 1905; E. 0. Ulrica and W. S. T. Smith, Prof. Paper II. S. 

Geol. Survey No. 36, 1905. On the tluor spar of San Roque, Cordoba, Argentina, see 

J. Valentin, Zeitschr. prakt. Geol., 1896, p. 104.
CHAPTER XIV.

MET AM ORPHIC ROCKS.

METAMORPHIC PROCESSES.

In its widest sense the adjective metamorphic may be applied to 

any rock which has undergone any sort of change. Practically, IIOAVever, 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 all that we need to consider at present.

The reactions involved in metamorphism are not difficult to classify. 

The following changes are probably the most important:

1. Molecular rearrangements, as in the process of uralitization, 

Avhen 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 Avhen serpentine breaks up into olivine and enstatite, or talc 

into a metasilicate and quartz.

501
502 THE 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 convenience, 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° 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 tAvo 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, 

the birthplace of such rocks as shales ajid sandstones. In the belt

0 Treatise on metamorphism : Mon. U. S. Geol. Survey, vol. 47, 1004.
METAMOBPHIC EOCKS. 503

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 rthat is, below the melting point of 

the rocks, but possibly .above the critical temperature of water. 

Under these conditions the reactions of the upper zone are reversed. 

Instead of hydration, there is dehydration; reduction is more common than oxidation; carbonates are decomposed and silicates are 

regenerated. Pneumatolytic reactions are characteristic of this 

region, and so too are metasomatic changes. There is also a tendency 

to the development, under pressure, of the heavier and denser rockforming minerals and of the species which contain constitutional 

water, fluorine, or boric oxide. Garnet, staurolite, muscovite, epidote, and tourmaline are, for examples, typical minerals of the metamorphic rocks.

According to'C. R. 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 Aveathering. 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 their interruptions. The definite products to which 

we give definite names represent temporary stoppages or periods of 

slow change in the progress of the cycle.

In both zones of the lithosphere water is the chief agent of chemical metamorphism. It is most abundant in the zone of 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 subcapillary and 

intermolecular spaces, where, because of the higher temperatures, it
504 THE- DATA OF GEOCHEMISTEY.

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 Avas shown by -C. Barns a 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 ^theref ore 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. O ^

The sediments, as a rale, 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 nearly or quite complete. It must not be assumed, however,

a See ante, p. 244.
A., METAMORPHIC ROCKS.- 505

 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,0 and its activity

v 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

i of fairly pure limestone or dolomite reaches the anamorphic zone, it 

is recrystallized into marble. This change, and also the formation

4 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 Aveathering 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 dif-

-^ ferent 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.

A CLASSIFICATION.

The classification of the metamorphic rocks is not a simple matter.

The criterion of structure is not sufficiently general, and that of

genesis is too vague. We can not always determine the genesis of

a given rock, and when we are able to do so, the result, for purposes

of classification, may be unsatisfactory. A gneiss can be derived

"' from an igneous rock or from one of sedimentary origin, the product

_, being sensibly the same in both cases. It is possible, of course, to

0 See ante, pp. 224-232, for the experiments of Tilden, Travers, Gautlei1 , etc.
506 THE DATA OF GEOCHEMISTRY.

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.11 Quite dissimilar rocks 

may have very similar composition. In fact, no single classificatibn covers all the ground; for the phenomena of nature do not 

arrange themselves in linear sequence. They form an irregular network of interlacing lines, with all manner of intersections and frequent disturbances.

Taking all of the difficulties into account, I prefer to study the 

metamorphic rocks, so far as may be practicable, with, reference to 

the chemical processes which have governed their formation. I have 

already stated that several processes may take part in a single 

metamorphosis; but in many cases one process predominates. The 

conspicuous process, then, gives a basis for classifying our data, 

which need not, however, exclude other arrangements for other purposes. The method supplements, but does not supplant its rivals. 

For convenience we may also divide the metamorphic rocks into three 

classes, as follows: First, those derived from igneous rocks; second, 

those of sedimentary origin; third, rocks formed by contact reactions between the igneous and the sedimentary.

The metamorphism of the igneous rocks is commonly a deep-seated 

phenomenon; that is, its conspicuous examples are formed in the 

zone of anamorphism, or under anamorphic conditions. Leaving 

mechanical or structural changes out of consideration, its conspicuous feature is of the order of a molecular rearrangement; in other 

words, the older minerals are transformed into new species,'sometimes by simple paramorphism and sometimes with transfer of material from one molecule to another. In general., as F. Becke 6 

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, zdisite, 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. Grubehmann; c 

and although the calculations are necessarily crude, they are none

rt 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.

6 Neues Jahrb., 1896, pt. 2, p. 182.

c Die Kristallinen Schiefer, pp. 34-38, Berlin, 1904. Grubenmann's data are taken 

from a paper by. F. Becke, in Compt. Rend. IX Cong. g^ol. intermit., p. 553, 1903. 

See also F. Loewinson-Lessing, Studien liber die Eruptivgesteine: Compt. Rend. VII 

Cong. g6ol. internal., St. Petersburg, 1897.
METAMOEPHIC BOCKS. 507

the less conclusive.0 ( 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 scapplite.

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 ilinenite.

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.

URAMTIZATION.

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.6 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 fi 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

0 For a tabulation of the volume changes attending the alteration of minerals, see 

C. R. Van Hise, Treatise on metamorphism : Mon. U. S. Geol. Survey, vol. 47,. pp. 397- 

408, 1004.

" See G. H. Williams, Bull. U. S. Geol. Survey No. 62, p. 52, 1890, for 'a full discussion of this subject, accompanied by abundant references to literature. See also L. Duparc and T. Hornnng, Compt. Itend., vol. 139, p. 223, 1904, on a theory of uralitlzation.

f British Petrography, p. .198, 1888; also in Quart. Join-. Geol. Soc., vol. 41, p. 137, 

1885.
508 THE DATA OF GEOCHEMISTEY.

analyses will serve to illustrate the character of the changes thus 

produced:

Analyses of pyroxene rocks before and after alteration.

Aa. The plagioclase-pyroxene rock of the Scourie dike.

Ab. The derived hornblende schist. Analyses by Teall, loc cit.

Ba. Pyroxene from the center of a crystal, Templetbn, Canada.

Bb, Intermediate portion of the same crystal. ^

Be. Hornblende forming the rim of the crystal. Analyses B by B. .1. 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.

SiO«......... ...................

AlsOa..........................

FpoO«

FeO. ...........................

MnO..................:.......

MgO. ..........................

CaO... .........................

Na20 ..........................

K80............. ...............

HsO... .........................

TiOi.. .........................

COs.- ..........................

Aa.

47.45

14.83

2.47

14.71

5.00

8.87

2.97

.99

i nn

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

"1.44

100.49 

3.181

Bb.

50.90

4.82

1.74

1.36

.15

15.27

24.39

.08

.15

ol.20

100.06 

3.205

Be.

52.82

3.22

2.07

2.71

.28

19.04

15.39

.90

.69

99.52 

3.003

Ca.

53.53

3.12

5.09

13.54

18.77

6.19

.20

101.01

Cb.

52.73

4.70

5.26

10.21

12.59

19 >;a

.23

.06

1 54

99.90

a Loss on ignition.

That the change from pyroxene to uralite or amphibole is something 

more than a paramorphism these few analyses clearly show. In A 

there has been oxidation of ferrous to ferric iron, in B a loss of lime, 

and in C a loss of magnesia, In many cases uralitization is accompanied by a separation of magnetite,0 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.'' Between the 

original igneous rock and the secondary amphibolites, there are all 

possible intermediate gradations, from incipient change to complete 

transformation.

u GJjATJCOPHANE SCHISTS..

The glaucophane schists differ from the amphibolites in that they 

contain the soda amphibole instead of hornblende. H. S. Wash-

" See G". Rose, Zeitschr. Deutsch, geol. Gesell., vol. 16, p. 6, 1864 ; E. Svedmark, Neues 

Jahrb., 1877, p. 90.

"See discussion of the change by C. 11. Gordon, Am. Geologist, vol. .'M, p. 40, 1904.
METAMORPHIC ROCKS. 509

ington a 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,6 for example, has described a garnetglaucophane schist from Mount Diablo, California; and A. Wichmann c an epidote-mica-glaucophane schist from Celebes. A zoisiteglaucophane schist from Sulphur Bank, California, is also mentioned 

by G. F. Becker/2 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,c is called a glaucophane 

eclogite.

Genetically, the glaucophane rocks differ widely. Some of them 

are undoubtedly derived from mediosilicic or subsilicic igneous rocks; 

others from sedimentaries. In Greece, for example, according to R. 

Lepsius/ 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 cliorite, and in this rock alterations of glaucophane to chlorite occur. In 

Piedmont, as described by S. Franchi,'1 there are glaucophane rocks 

associated with amphibolite, both having been derived from diabase. 

In Japan, according to B. Koto,* 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 J 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 

of origin will be disregarded here and the analyses of this group of 

rocks are tabulated together, as follows:

« Am. .Tour. Scl., 4th ser., vol. 11, p. 85, 1901. 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, p. 634, 

1886; U. Grubenmann, Rosenbusch " Festclmft," 190G ; E. H. Nutter and W. B. Barber, 

.Tour. Geol., vol. 10, p. 738, 1902; and J. P. Smith, Proc. Am. Phil. Soc., vol. 45, p. 183, 

1906. The last two papers relate to the glaucophane rocks of California.

" Bull. Geol. Soc. America, vol. 2, p. 413, 1890.

< Neues Jahrb., 1893, pt. 2, p. 176.

"Mon. U. S.-Geol. Survey, vol. 13, p. 104, 1888.

0 Mineralog. Mag., vol. 7, p. 1, 1887.

'Geologic von Attika, pp. 102, 133, Berlin, 1893. 

. " Geol. Mag., 1888, p. 125.

* Bol. Com. geol. ital., vol. 20, p. 192, 1895.

1 Jour. Coll. Sci. Japan, vol. 1, p. 85, 1886.

i Bull. Dept. Geology, Univ. California, vol. 1, p. 211.
510 THE DATA OF GEOCHEMISTRY.

Analyses of amphibolites and glaucophane schists.a

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, p. 3G, 1904.

C. Amphibolite, Crystal Falls district, Michigan. Described by H. L. Smyth, Mou. 

U. S. Geol. Survey, vol. 36, p. 397, 1899. 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, p. 413, 1890. 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, p. 35, 1901. Contains glaucophaue, epidote 

or zoisite, garnet, and white mica.

F. Zoisite-glaucophane schist, Sulphur Bank, California. Analysis by Melville. Described by G. F. Becker, Moh. U. S. Geol. Survey, vol. 13, p. 104, 1888.

G. Mica-glaucophane schist, Island of Syra, Greece. Analyzed and described by Washington, loc. cit.

. II. Quartz-glaucophane schist, Fourmile Creek, Coos County, Oregon. Analyzed and 

described by Washington. Contains quartz, glaucophane, chlorite, muscovite, and garnet.

SiOs................ .................

VeoOi

FeO

MgO.... .............................

CaO... ..............................

NajO. ...............................

K20... ..............................

HsO-. ........ .:....................

HsO-K-.... ..........................

TiOj............... ...................

(X>2... ...............................

PjOo. ................................

S.. ..................................

VjOa.... .............................

CrzOs....- ...........................

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

.27

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

(?)

.28

(?)

(?)

trace?

100.46

C.

50.36

13.26

6.30

9.34

5.55

7.85

2.11

1.14

1.55

1.55

1.77

90

99.59

B.

47.84

16.88

4.99

5.56

7.89

11.15

3.20

.46

.17

1.81

.14

CC

100.65

E.

49.15

15.87

4.10

7.58

7.53

9.06

3.59

.54

.16

1.07

1 19

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

OS

1 V7

trace

99.67

H.

82.53

6.88

.59

4.11

1.86

68

1.21

.07

1.35

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. No. 228, pp. 34. 35. 

1904. These amphibolites are regarded as derived from argillaceous limestones. L. Hezner (Min. pet. Mitth., vol. 22, p.~505, 1903) gives several analyses of amphibolites from 

the Tyrol. See also a table of analyses in Rosenbusch, Elemente der Gesteinslehre, p. 

532. See also, on amphibolite, F. Becke, Min. pet. Mitth., vol. 4, p. 285, 1882; and J. A.

Ippen, Mitth. Naturwiss. Ver. Steiermark, 1892, p. 328. Ippen describes " normal amphibolite," and also zoisite-, pyroxene-, feldspar-, and garnet-amphibolite.

SEBICITIZATION.

The conversion of feldspar into muscovite is one of the commonest processes of metamorphism, whether of igneous or of sedimentary 

rocks. In many instances the mica produced is the compact or fibrous 

variety known as sericite, which, in former times, was generally mistaken for talc. The so-called talcose schists of the earlier geologists 

have proved in most cases to be not talcose, but sericitic.a The identity of sericite with muscovite was finally established by H. Lasa See G. H. Williams, Bull. U. S. Geol. Survey No. 62, pp. 60-62, 1890, for historical 

details.
METAMOEPHIC EOCKS. 511

peyres 0 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 \vorking together to bring it about. Any feldspathic rock may undergo 

$iericitization, 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.6

Sericite is commonly derived from orthoclase or microcline, as 

suggested above, but may be generated from plagioclase feldspars 

also, the reactions in the two cases being different. In the formation of muscovite from orthoclase the necessary potassium is already 

present; but in order to produce muscovite from plagioclase a replacement of sodium by extraneous potassium is required. In either 

case the reaction which takes place may be represented by more than 

one equation, although it must be admitted that the formulation is 

purely hypothetical. Until the processes shall have been experimentally reproduced the equations will remain doubtful.

First, orthoclase may be transformed to muscovite by the addition 

of colloidal alumina equivalent in composition to diaspore, thus:

KAlSi3O8+2AlO.OH=KH2AlaSi3Oi:; .

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 betAveen 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:

3KAlSi3 08+H2 0=KH2ALSi3O1 ,+K2SiO:( +5SiO2 .

In this case water alone, acting on orthoclase at a high temperature 

and under pressure, forms muscovite, free silica, and potassium silicate, the last compound being leached away. The liberated silica 

may be partly removed in solution,'or it can recrystallize as quartz, 

a mineral which almost invariably accompanies sericite in metamorphic rocks. Furthermore, the analyses of sericite usually show a

« Zeitschr. Kryst. Min., vol. 4, p. 245, 1879.

11 See J. G. Lehmann, Untersuchungen iiber die Bntstehung der altkrystallinlschen 

.Schiefergesteine, Bonn, 1884; A. Wlchmnnn, Verhandl. Natur. Ver. preuss. Rhelnl. u. 

Westfalens, vol. 34, p. 1, 1877 ; A. von Groddeck, Neues Jahrb., Bell. Bd. 2, p. 72, 1883; 

C. Schmidt, idem, Beil. Bd. 4, p. 428, 1886, and C. Benedicks, Bull. Geol. Inst. Upsala, 

vol. 7, p. 278, .1904-5. .In Jahrb. K. pi-euss. geol. Landesanstalt, 1885, pt. 1, Von Groddeck describes the derivation of sericite schists from clay slates.
512 THE DATA OF GEOCHEMISTEY. ^

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 

folloAvs: . ^

3KAlSi3O8+H2O+CO2 =KH2Al3Si3 012+K2C03+6SiO2 . ^

In this case, however, the potassium carbonate would dissolve one 

molecule of the liberated silica, forming potassium silicate as before. 

The COS would thus be set free again, ready to assist in further alterations of feldspar. Since carbonated waters, both of meteoric and i 

of deep-seated origin, are very abundant, it is quite possible that i 

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.0 If the alteration took 

place in presence of both albite and orthoclase, the potassium silicate - r 

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. j

i

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.6 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 v 

remain, which were once thought to represent a distinct mineral species and to which the name saussurite was given. The mechanism of 

the change is obscure, but it is probably a double decomposition 

between the albite and anorthite molecules, brought about by the 

intervention of water. The feldspars, however, vary in composition; 

the water may contain other reacting substances in solution, and so

"Compare W. Lindgren, Trams. Am. Inst Min. Eug., vol. 30, p. 608, 1900, in reference 

to the association with calcite. """

6 See K. A. Lossen, Jahrb. K. pveuss. geol. Landesanstalt, 1884, pp. 525-530. See also 

G. H. Williams, Bull. U. S. Geol. Survey No. 62, p. 60, 1890.
METAMORPHIC BOCKS. 513

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:

NaAl'Si8 08+4CaAl2 SiA+2H2 0=

Albite. Auortliite. Water.

2Ca2HAl8 Si3O18 H-H2NaAl8 Si8O12+2SiO2 . 

Zoisite. Paragouite. 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,a saussurite is sometimes derived from garnet; arid 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 b reports a 

saussurite gabbro from Greece, consisting of saussurite and diallage, 

the latter partly altered to hornblende. P. Michael 0 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.'2 It contained saussurite derived 

from the complete alteration of plagioclase; diallage;. hornblende, 

partly secondary; and a little ilmenite, with some calcite, quartz, and 

a colorless chlorite. By further alteration, this rock passes into a 

silvery schist, consisting mainly of chlorite, calcite, and secondary 

quartz, but with some feldspars remaining, partly sericitized. A 

rock designated as a zoisite-hornblende diorite, from the Bradshaw 

Mountains, Arizona, described by T. A. Jaggar and C. Palache,0 

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 

Avere made in the laboratory of the United States Geological Survey:

Analyses of ssoisitc rocky.

A. Stiii-goon Fulls gabbro, freshest form. 

B. The same, altered form.

C. Silvery schist derived from Sturgeon Falls gabbro. Analyses A, B, and C by It. B. 

Kiggs.

D. Zolslte-hornblende diorite, Bradshaw Mountains. Analysis by George Sfeiger.

" Zeitschr. Kryst. Min., vol. 10, p. 444, 1885.

"Mln. pet. Mitth., vol. 1, p. 247, 1878.

'Neues Jahrb., 1881, pt. 1, p. 32.

 ' Bull. U. S. Geol. Survey No. 62, pp. G7-7G, 1890. Another saussuritized gabbro from 

(lie Upper Quinnesec Falls is described on pp. 102-104. On pp. 58-60 Williams gives .1 

general discussion of this form of alteration, with historical details. See also A. Cathrein, Zeitschr. Kryst. Min., vol. 7, p. 234, 1883.

« Geologic Atlas U. S., folio 126, pp. 4-5, U. S. Geol. Survey, 1905.

14399 Bull. 330 08 33 ' .
514 THE DATA OF GEOCHEMISTKY.

SiOt. ............................. .............................

A1 203 . .........................................................

Fe2O3 ..........................................................

FeO ...........................................................

MgO........................... ................................

CaO ...........................................................

Na20 ..........................................................

K20 ...........................................................

HsO- . ........................................................

II20+..................... ....................................

TiOs . ..........................................................

CO2 . ...........................................................

P205 .. .........................................................

A.

51. 46

14.35

3.90

5.28

9.54

9.08

2.92

.24

1 3.30

90

100.27

B.

38.'05

24.73

5.65

6.08

11.58

1.25

2.54

1.94

\ 7.53

.93

100. 28

C.

45.70

16.53

4.63

3 89

9:j7

4.28

.55

3.82

] 4.70

5.95

99.62

D.

45.73

19.45

5.28

3.18

6.24

13.86

.64

.32

1.57

3.56

.23

.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,® 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," 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 Avhich some of 

the chlorine essential to the formation of scapolite may have been 

derived.

In any -case, the conversion of plagioclase to scapolite requires the 

addition of new material. The scapolites, as shown by G. Tschermak,c are mixtures of two end species meionite, Ca4Al6Si6 025 , and 

marialite, Na^AL^SigO^Cl. These may be derived from anorthite 

and albite in accordance with the following empirical equations:

3CaAl2Si2O8+CaO=Ca4Al6Si0O25 . 

3NaAlSiA+NaCl=Na4AI3Si9 024Cl.

"Bull. Soc. min., vol. 2, p. 113, 1879.

6 Min. Mag., vol. 8, p. 186, 1889. See also A. Micbel L6vy, Bull. Soc. ruin., vol. 1, pp. 

43, 78, 1878. A similar rock from Bamle, Norway, containing sphene, arnphibole, 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. Foi'handl., vol. G, p. 

192, 1882 ; vol. 7, p. 293, 18S4.

c See the section on scapolite in Chapter X, p. 337, ante.
METAMORPHIC BOOKS. 515

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 

Avell summarized by A. Lacroix,0 whose two memoirs upon the subject 

are most exhaustive.

On the epidotization of .plagioclase feldspar there is an abundant 

literature. 6 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 c 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 d found epidote derived 

from orthoclase, plagioclase, biotite, and hornblende. G. H. Williams ° observed its formation as a contact rim between feldspar and 

hornblende in the gabbro-diorite near Baltimore, and F. D. Chester f 

described similar occurrences in Delaware. In some of Chester's 

specimens the epidote contained cores of feldspar.

0 Bull. Soc. rain., vol. 12, p. 83, 1889 ; vol. 14, p. 16, 1891. Lacroix states that wernerlte gneisses nre very common. Lacroix and C. Baret (idem, vol. 10, p. 288, 1887) describe a wernerite pyroxenite. Wernerite, it will be remembered, .is one of the intermediate scapolites. See also H. Wulf, Min. pet. Mitth., vol. 8, p. 213, 1887, on a scapolite-augite gneiss from I-Ierero Land, Africa; and F. Becke, idem, vol. 4, p. 285, 1882, on 

similar rocks from Lower Austria. Scapolite amphibolites are described by 0. Mtigge, 

Neues Jahrb., Beil. Bd. 4, p, 583, 1886, from Masai Land ; E. Bathe, Jahrb'. K. preuss. 

geol. Landesanstalt, 1884, p. Ixxvi, from Germany ; and F. D. Adams and A. C. Lawson, 

Canadian Rec. Sci., vol. 3, p. 185, 1888, from Canada. Adams and Lawson also describe 

two scapolite diorites. The Alaskan scapolite rocks collected by J. E. Spun: (Am. Jour. 

Sci., 4th ser., vol. 10, p. 310, 1900) are-regarded by him as primary and not metarnorphic. 

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, p. 273, 

189G) has described the transformation of a gabbro into a gneiss containing pyroxene, 

hornblende, feldspar, and scapolite.

" See A. Cathrein, Zeitschr. Kryst. Min., vol. 7, p. 247, 1883 ; A. Schenck^ Verhandl. 

Naturhist. Ver. preuss. Kheinl. u. Westfalens, vol. 41, p. 53, 1884 ; and G. H. Williams, 

Bull. U. S. Geol. Survey No. 62, p. 56, 1890, for summaries of the earlier observations.

c Mon. U. S. Geol. Survey vol. 3, 1882, pp. 75, 76, 213. Criticised by Williams, loc cit., 

and H. Rosenbusch, Neues Jahrb., 1884, pt. 2, Ref., p. 189.

"Mon. U. S. Geol. Survey, vol. 12, pp. S41, 357. 1886.

r- Bull. U. S. Geol. Survey No. 28, p. 31, 1886.

/ Bull. U. S. Geol. Survey No. 59,' p. 35, 1890.
516 THE DATA OF GEOCHEMISTRY.

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 a describes an alteration of this kind from augite porphyry; 

and Schenck * 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 ° from western 

North Carolina. It has since been found near Milam's Gap, Virginia. 

According to W. C. Phalen,* 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.^

Eclogite is essentially a rock composed of red garnet, Avith 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.*7 According to J. A. Ippen,'1 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 A. 

Lacroix,* sometimes contain feldspar formed as a secondary mineral 

during the uralitization of highly aluminous pyroxenes. Lacroix 

shows that these rocks are products of dynamometamorphism. The 

crushing and fracturing of the original rocks has facilitated the circulation of the waters to which their alterations are due.

" Zeitschr. Deutsch. geol. Gesell., vol. 29, p. 498, 1877.

6 Verhandl. Naturhist. Ver. preuss. Rheinl. u. Westfalens, vol. 41, p. 53, 1884.

"Am. Jour. Sci., 3d ser., vol. 7, p. 519, 1874.

d Misc. Coll. Smithsonian Inst, Quart. Issue, vol. 1, p. 301, 1904.

" Ann. Kept. State Geologist New Jersey, 1895, p. 30.

t See Zirkel's Lelirbuch 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.

o See R. von Drasche, Jahrb. K.-k. geol. Reichsanstalt, 1871, Mm. Mitth., p. 85, and 

B. R. Riess, Min. pet. Mitth., vol. .1, pp. 165, 181, 1878.

71 Mitth. Naturwiss. Ver. Steiermark, 1892, p. 328.

1 Bull. Soc. sci. nat.de 1'Ouest de la France, vol. 1, p. 81, 1891.
METAMOBPHIC ROCKS. 517

' L. Hezner/' who studied eclogite from the Oetzthal, in the Tyrolese 

Alps, regards it as a metamorphic derivative of gabbroid rocks. By 

further metamorphosis it passes into amphibolite, the eclogite being 

the deeper-seated phase. The garnet, he thinks, was formed by a

, reaction betAveen 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. Epldosite derived from diabase, upper Rnhrthal, Germany. Analyzed and 

described by Schenck.

 y C. Unakite, Milam's Gap, Virginia. Analysis by Phalen. 

D. Eclogite, Sulzthal, Styria. 

B. Eclogite, Burgstein, Styria. Analyses D and E by Hezner.

Si02 ..........................................:......

Al a03 . ..............................................

FesOs.......... ......................... : .........

FeO.............. ...................................

MgO.... ............................................

CaO ..................................................

NaaO........ .......................................

K20..... ............................................

HsO-. ..............................................

H80 + ....... ........................................

Ti02 . ................................................

ZrOj..... ...........................................

Pj06 ......... .......................................

MnO ................................................

A.

42.13

19. 21

11.19

2.52

.41

21.42

.29

.08

1 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. oo

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

" Not separated from alumina. 

CHLORITIZATION.

In chloritization we find a stage of metamorphism which is nearly 

akin to decomposition. Any ferromagnesian mineral may alter into 

chloritic material, and that, by further change, may break down into 

a mixture of carbonates, limonite, and quartz. The gabbros of Michigan, described by G. H. Williams,6 show clearly the successive steps 

of uralitizatibn and chloritization, the final product often being a 

chloritic schist. Diabase and diorite are often chloritized, gaining

« Min. pet. Mitth., vol. 22, pp. 437, 505, 1903. See also E. Joukowsky, Compt. Rend., 

vol. 133, p. 1312, 1901, on alterations of eclogite from Lac Cornu. Other valuable 

papers upon eclogite are by P. Lohrnann, Neues Jahrb., 1884, pt. 1, p. 83 ; and P. Becke, 

Min. pet. Mitth., vol. 4, pp. 317-322, 1882. Eclogites from California have been described by R. S. Holway, Jour. Geol,, vol. 12, p. 344, 1904, and J. P. Smith, Proc. Am. 

Phil. Soc., vol. 45, p. 183, 1906.

"Bull. U. S. Geol. Survey No. 62, 1890.
518 THE DATA OF GEOCHEMISTRY.

 v

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." 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, 

Eosenbusch 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. Giimbel.

CONSTITUTIONAL FORMULA.

Although it is not yet possible to write positive reactions for all 

of the alterations that we have so far been considering, some of them 

are partly elucidated by the structural formulae of several minerals. 

A number of these species are curiously alike in constitution, and with 

them other minerals, not specifically studied in this chapter, may 

also be compared. Taking the tripled formulae of orthoclase and 

albite, Avhich are suggested by the alteration of albite into marialite, 

the following system of formulae can be developed: 6

Orthoclase_________________Ala (Si308 ) 3K3. 

Albite.__.____________________AI,(Si,O8 ),Na,. 

Marialite__________________.__.___.Al2 (Si3O8 ) 8Na4 (AlCl).

Nephelite_______^____________.Al3 (SiO4 ) 3Na3 .

Paragonite.____________________Al3 (SiO4 ) 3NaH2 .

Muscovite________________________Al3 (SiO4 ) 3KH2.

Topaz________________________ _________Al3 (Si04 ) 3 (AlF2 ) 3.

Andalusite _.______.__._________.__-Al3 (Si04 )3(A10) 3

Biotite_________________________A.l2 (SiO4 ) 3Mg2KH.

Garnet________________________A.l2 (SiO4 ) 3Ca3.

Prehnite_______________________Al2 (SiO4 ) 3Ca2H2. 

Zoisite. - _____________________Al2 (SiO4 ) 3Ca: (AlOH).

Epidote resembles zoisite, but with iron partly replacing aluminum, 

and similar replacements exist in the garnet group. Anorthite,

a See G. W. Hawes, Am. Jour. Sci.,- 3d ser., vol. 9, pp. 190, 454, 1875. Also A. 

Schenck, Verhandl. Naturhist. Ver. preuss. Rheinl. u. Westfalens, vol. 41, p. 74, 1884. 

Chlorltizatlon is fully discussed by Rosenbusch, in his Mikroskopische Physiographic der 

massigen Gesteine, 2d ed., vol. 2, pp. 180-184.

6 See F. W. Clarke, Bull. U. S. Geol. Survey No. 125, 1895, for.an extended discussion 

of these formulae.
METAMOEPHIC EOCKS. 519

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 becomes 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. 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:

2Mg2SiO4+2H2O+CO,=Mg8H4Si2O0+MgCO,.

Olivine. Serpentine. Magnesite.

Peri'dotites are especially liable to this sort of alteration, and 

many serpentine rocks can be assigned this origin.0 The well-known 

Lizard serpentine of Cornwall, for instance, has been shown by 

T. G. Bonney & to be an altered Iherzolite.

Pyroxenes, also, are often converted into serpentine. The equation, in the case of diopside, is perhaps as follows:

3MgCaSi 2Oe+3CO2H-2H2O=Mg3H4Si,On+3CaCO3 -f4SiOo.

Diopside. Serpentine. Calcite. Quartz.

0 See F. Sandberger, Neues Jahrb., 1866, p. 385; idem, 1867, p. 176. G. Tschermak, 

Sitzungsb. Akad. Wlen, vol. 56, p. 261, 1867. E. Weinscbenk, Abhandl. K. bayer. Akad., 

Math. phys. Klasse, vol. 18, p. 651. .T. Lemberg, Zeltschr. Deutsch. geol. Gesell., vol. 27, 

p. 531, 1875. B. Welgand, Jahrb. K.-k. geol. Reichsanstnlt, 1875, Mln. Mitth., p. 183. 

F. Zirkel (Lehrbuch der Petrographle, 2d ed., vol. 3, p. 404) gives an extensive bibliography of serpentine.-

*Quart. Jour. Geol. Soc., vol. 33, p. 884, 1877.
520 THE .DATA OF GEOCHEMISTRY.

This reaction is sustained by the fact that serpentine rocks often 

contain quartz and calcite. Whe"h serpentine is formed from gabbro 

or pyroxenite the change is probably of this kind, although it ma}' 

have been preceded by uralitization of the pyroxene. Serpentines 

derived from amphibolites have been repeatedly described.0

In short, serpentine may be formed from any silicate which happens to be rich in magnesia, such as olivine, pyroxene, amphibole, 

garnet,6 or chondrodite.0 It also appears to be produced by the 

action of percolating magnesian waters upon nonmagnesian minerals, 

such as feldspars, and possibly, even, quartz.** J. Lemberg 6 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 pseudpmorphous 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/ the parent minerals were tremolite or actinolite. It impossible 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 ° 

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 h to be derived from pyroxene, and the 

same conclusion was reached regarding the ophiolite or ophicalcite 

of Warren County, New York/ The " verde-antique " marbles are 

familiar illustrations of this commingling of carbonates with serpentine. A quite different blending of serpentine with other minerals is 

that described by me from Stephens County, Washington.-* This mix-

"B. K. Emerson (Mon. U. S. Geol. Survey, vol. 29, p. 114, 1898) 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, p. 21, 

1896-1898.

"See A. Schrauf, Zeitschr. Kryst. Min., vol. 6, p. 321, 1882.

c See J. D. Dana, Am. Jour. Sci., 3d ser., vol. 8, p. 371, 1874, on serpentine pseudomorphs from the Tilly Foster mine.

« See G. F. Becker, Mon. U. S. Geol. Survey, vol. 13, pp. 108-128, 1888.

 Zeitschr. Deutsch. geol. Gesell., vol. 22, p. 345, 1870; vol. 24, p. 255, 1872.

r.Am. Jour. Sci., 3d ser., vol. 20, p. 30, 1880.

»Mon. D. S. Geol. Survey, vol. 12, p. 282, 1886.

h Proc. U. S. Nat. Mus., vol. 11, p. 105, 1888.

'Am. Jour. Sci. 3d ser., vol. 20, p. 30, 1880.

i Bull. U. S. Geol. Survey No. 262, p. 69, 1905.
METAMORPHTC BOCKS. 521

ture 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 a 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.& The 

acids of volcanic fumaroles had removed the bases of the serpentine 

in the form of soluble sulphates.

From what has been said so far it is evident that serpentine originates in various different ways. Some serpentine is merely altered 

peridotite, pyroxenite, or gabbro; and some of it is derived from 

dolomite or other sedimentary rocks. Indeed, the sedimentary origin 

of serpentine has had many strong advocates, the chief among them 

having been the late T. Sterry Hunt.0 L. Dieulaf ait d 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 :

Mg3H4Si2 09 =Mg2Si04+MgSi03 +2H2 0.

Talc, like serpentine, may originate in different ways ; but its commonest derivation . seems to be by the alteration of amphiboles or 

pyroxenes. C. H. Smyth,6 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 :

0 MOD. U. S. Geol. Survey, vol. 13, p. 127, 1888. 

"Compt. Rend., vol. 124, p. 513, 1887.

0 Mineral Physiology and Physiography, pp. 434-516, 1886. Hunt cites a large amount 

of evidence from Italian sources.

* Compt. Rend., vol. 91, p. 1000, 1880.

 School of Mines Quart, vol. 17, p. 333, 1896.
522 THE DATA OP GEOCHEMISTRY.

4MgSiO8+H,0+CO,=Mg3H2SiA-»+MgC08 . - 

Mg3CaSiA2+H2 0+C02 =Mg3H2SiA2+CaCO3 .

These reactions are much alike, and resemble those which are recognized in the formation of serpentine. In fact, many serpentines 

contain admixtures of talc, and when the original rocks are at all -, 

aluminous, chlorites also may appear. Soapstone or steatite is impure, massive talc.

According to Smyth, the St. Lawrence County talc is found associated with crystalline limestones. J. H. Pratt 0 found the deposits 

of North Carolina to be in connection with marble, and capped by 

quartzite. In the same region pyrophyllite occurs, a hydrous sili- ^ 

cate of aluminum, HAlSi2 00 , which much resembles talc and may 

be mistaken for it. The talc itself appeared to be derived from 

tremolite. Smyth assumes that a siliceous limestone was first laid 

down, which became, by metamorphism, a tremolite-enstatite schist. 

The latter, by hydration, became talc. This, however, is not the 

only way in which steatite has been formed. A. Gurlt 6 reports its -y 

formation from dolomite along contacts with amphibolite; and C. H. 

Hitchcock ° regards the steatites of New Hampshire as alterations 

of what was originally igneous matter. 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.* 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.

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, p. 372, 1898. Derived mainly from pyroxene. Analysis by W. H. <_ 

Melville.

. C. Serpentine, Sulphur Bank, California. Described by G. P. 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, p. 403, 1890.

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, p. 69, 1905. Analysis by G. Steiger.

H. Steatite, Griqualand West, -South Africa. Described by E. Cohen, Neues .Tahrb., 

1887, pt. 1, p. 119. Analysis by Van Riesen.

0 North Carolina Geol. Survey, Econ. Paper No. 3, 1900.

6 Sitzungsb. Niederrhein. Gesell., Bonn, 1865, p. 126.

c Jour. Geol., vol. 4, p. 58, 1890.

<* E. Weinschenk, Zeitscnr. Kryst. Min., vol. 14, p. 305, 1888. '
METAMOEPHIC BOOKS. 523

AljOs.... ".........:.................

FeO... ..............................

MgO.... .............................

CaO .................................

Nn»0.. ...............................

KaO .................................

HjO................................

H.O+...............................

Ti02 .................................

COj..................................

P2 05 .................................

CrjOa................................

NiO.................................

CoO. ................................

MnO................................

SO8 . .................................

FeSs.................................

A.

40.42

1.8G

2.75

4.27

35.95

.66 } - lfc

.21

10.51

1.44

.28

13

.43

99.47

B.

39. 14

2.08

4.27

2.04

39.84

\ 12.70

.11

100. 18

C.

41.86

.69

4.15

38.63

\ 14. 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

99.83

G.

13.08

1.63

1.25

.19

56.44

.33

.85

23.94

2.03

99.74

H.

63.29

1.24

.16

4.68

27.13

| 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 Avith 

these niagnesian eruptives.

QUABTZITE.

The processes which operate in the metamorphism of sedimentary 

rocks are partly identical with those which we have just been considering. This fact h,is already been indicated in several connections. 

A shale, or sandstone, contains fragments of minerals, usually more or 

less weathered, and these undergo the normal changes. Feldspar becomes sericite, hornblende alters to chlorite, and so on, exactly as in 

the metamorphoses of igneous material. The substances affected are 

the same, and so are the reactions. The formation of serpentine from 

pyroxene, for example, is, as I have already said, the same process, 

whether it is effected upon the pyroxene of a gabbro or upon the 

pyroxene developed by contact metamorphism in a crystalline limestone.

There is, however, another set of changes which are peculiar to the 

sedimentaries. These rocks contain decomposition products, such as 

kaolinite, hydroxides of aluminum and iron, etc., which give rise to a 

different group of reactions, and these generate another class of mineral species. Kyanite, andalusite, sillimanite, staurolite, and dumortierite are among the minerals thus developed in schists, which once 

were shales. These minerals, again, can alter into mica, so that a 

mica schist may represent the outcome of a series of transformations, 

the intermediate products having disappeared.

Just as the sedimentary rocks shade into one another, so, too, do 

their metainorphic derivatives, but with even greater complexity. 

For the metamorphosed rocks contain not only the original minerals
524 THE DATA OF GEOCHEMISTRY.

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/

The following analyses of quartzite and quartz schist are useful for 

comparison with the analyses of sandstones given in the preceding 

chapter.

Analyses of quartzite and quarts; 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, p. 302, 1898. Analysis,by E. A. Schneider.

Si02 . ..........................................................

AliOs... .......................................................

FeO....... ....................................................

MgO....... ............,.................:.....................

CaO....... ....................................................

Na2 0 ..........................................................

K2 0....... ....................................................

HsO........... ................................................

Ti02 .. .........................................................

PiO».................... ........................................

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

1 2.61

.72

99.91

C.

a92.00

4.21

1 80

. .04

.16

1.16

6.96

.14

.21

100.68

D.

91.65

1.59

3.57

.21

 .17

.07

1.93

.60

.13

99.92

a 84.13 per cent quartz, 7.87 per cent combined silica. * 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

a For a full discussion relative to the formation of quartzite, see C. R. Van Hise, 

Treatise on metamorphism : Mon. U. S. Geol. Survey, vol. 47, pp. 865-880, 1904. See also 

R. D. Irving, Bull. U. S. Geol. Survey No. 8, p. 48, 1884 ; and Am. .Tour. Sci., 3d ser., vol. 

25, p. 401, 1883. Important papers on the subject have been written by C. Lessen, 

Zeltschr. Deutsch. geol. Gesell., vol. 19, p. 615, 1867, and W. J. Sollas, Sci. Proc. Roy. 

Dublin Soc., vol. 7, p. 169, 1892.
METAMOBPHIC BOCKS. 525

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.0 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 

into quartz. These changes are of the simplest character, but it is 

not certain that they always take place. It is possible that the 

colloidal silica may react upon the colloidal hydroxides, and form 

silicates anew; but I am not sure that this class of reactions has been 

proved. They are conceivable, and therefore can not be left out of 

account. The known changes, as I have stated them, are those of 

the compounds themselves when not commingled with other substances. . Hematite, magnetite, corundum, and quartz can be formed 

in the manner indicated; and hematite or magnetite schists (schists 

containing these minerals in conspicuous proportions) are not rare. 

The itabirite of Brazil is a rock of this kind, containing hematite, 

magnetite, and quartz. 6 Similar rocks have been described by H. 

Coquancl c in France, and 0. M. Lieber a in South Carolina. Coquancl's rock is described as equivalent to a mica schist containing 

specular hematite in place of mica. . Itabirite from Okande Land, 

West Africa, is reported by 0. Lenz c as containing quartz, hematite, 

and magnetite, \vith quartz predominating. Another example from 

the Gold Coast, described by C. W. Giimbel/ contains also muscovite, 

ilmenite, and free gold. A German schist examined by C. Lossen <J 

consisted of specular hematite and quartz.

a If a bed of limonite be regarded as a sedimentary rock, a bed of hematite may be its 

metamorphic equivalent.

6 See Zirkel, Lehrbuch der Petrographie, 2d ed.,. p. 570, for references.

c Bull. Soc. gC'Ol., 2d ser., vol. 6, p. 291, 1849.

'' Kept. Survey South Carolina, 1855, pp. 89-94; 1857, p. 79 ; 1858, p. 107.

« Verhandl. K.-k. geo'l. Reichsanstalt, 1878, p. 168.

' Sitzungsb. Akad. Miinc.hen, 1882, p. 183.

n Zeitschr. Deutsch. geol. Gesell., vol. 19, p. 614, 1867. Zirkel refers also to Norwegian 

examples reported by J. H. L. Vogt in a memoir which I have not seen.
526 THE DATA OF GEOCHEMISTKY.

FERRUGINOUS SCHISTS.

The ferruginous schists of the Lake Superior region may properly 

be mentioned here. According to C. R. Van Hise,0 they are derived 

from carbonate rocks which he calls sideritic slates. These, by oxidation, pass into li.moni.tic or hematitic slates, and from the latter the 

schists are derived. Ferruginous cherts are also formed, and some 

banded rocks of chert and hematite which Van Hise calls jaspilite. 

The silicification of the original siderite is attributed to the action of 

silica contained in percolating waters. The following analyses of the 

schists were made in the laboratory of the United States Geological 

Survey:

A. Griinerite-magnetite schist, Marquette region, Michigan. 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-magnetite schist, Mesabi Range, Minnesota. Described by W. S. Bayley, 

Am. Jour. Sci., 3d ser., vol. 46, p. 178, 1893. Consists of actinolite and magnetite. 

Analysis by W. H. Melville.

Analyses of ferruginous schists.

AhOs. ..............................................................................

Fe2O 3 . ..............................................................................

FeO........ ........................................................................

MgO.......... ................................................................. .'.....

CaO ................................................................................

Na20 ...............................................................................

H20 ................................................................................

TiO2 . ...............................................................................

T&s......................... ........................ ...............................

MnO. ...............................................................................

CuO.... ............................................................................

A.

46.25

.92

30.62

16.92

O10

1.69

.07

1.01

100.03

B.

12. 35

.10

58.68

21.34

4.08

1.91

.19

.12

.25

' 1.22

100. 24

DEHYDRATION OF CLAYS.

Rocks like those just considered, obviously, may vary from nearly 

pure amphibole to nearly pure iron ore, and the quartz-hematite 

schists may range between the two extremes in the same way. In all 

cases, however, the final product represents the dehydration of hydroxides, followed by partial reduction in the case of the magnetite 

schists. The origin of the hydroxides, whether from carbonates or 

from silicates, is a separate question.

The hydrous silicates of the sediments are chiefly those of aluminum. Some iron compounds also occur, such as glauconite, chloropal, 

or nontronite, but their mode of decomposition when 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.

" Treatise on metamorphism : Mon. TJ. S. Geol. Survey, vol. 47, pp. 830-842, 1904. 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.
METAMOBPHIC BOCKS. 527

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.*

Many hydrous silicates of aluminum have been described. A few 

. of them are definite, others are more or less doubtful. Some, prob- 

) ably, are colloidal mixtures, which should not be formulated as distinct chemical compounds. The following minerals in this class are 

recognized by Dana as true species:

Kaolinite_ -_____________________H4Al2Si2O0 . 

j Halloysite ____________________H4A] 2Si 2 00 +aq. 

Newtonite__-______________.________H8Al2Si2Ou+aq.

Cimolite_____________ _ __________H0AL,Si9O:!7 -{-3 aq. ( V)

Montmorillonite ____ ______________H2Al2Si4Oi2 +M aq.

Pyrophyllite _ __ . I-V^SiAAllophane AlaSiOB.5aq. 

Collyrite -Al4Si08.9aq. 

Schrotterite_____ -AlioShO.-io.30aq.

To this list rectorite ?' and leverrierite ° 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 HyAl3Si3O12 , 

corresponding to muscovite, H2KAlaSi3 012 . Rectorite, according to 

R. N. Brackett and J. F. Williams, has the same composition, plus 

an excess of Avater, 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. 

A. Sauer's d analysis of it gives approximately the formula HAlSiO4 . 

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 musJ covite 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

: Al2 Si05 and SiO2 . Al2 Si05 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 metaraorphic schists, and must have been formed in most 

cases by some such process as that just indicated. Sometimes, how-

" See p. 521, ante.

"Am. Jour. Sci., 3d ser., vol. 42, p. 1C, 1801.

c Bull. Soc. min., vol. 22, p. 27, 1899.

'' Zeitschr. Deutsch. geol. Gesell., vol. 38, p. 705, 188G.
528 THE DATA OF GEOCHEMISTRY.

ever, other sources are to be assumed. For example, K. Dalmer a 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 " that sillimanite is a normal constituent of hard porcelain, in which it is derived from kaolimte; 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,c so that here we have a group of 

facts which bear obviously upon the interpretation of metamorphic 

processes. We do not yet know, however, the conditions which determine the formation in a 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.G. 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,'* contains andalusite inclosing sillimanite, both in every stage of clltemtion 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, HAl5FeSi2O13 , specific gravity 3.75, is another mineral 

of the metamorphic schists, and one closely allied to the andalusite 

group. Its formation evidently requires the presence of iron in 

the sediments, and also conditions of temperature and pressure which 

could permit the retention of water. Garnet is one of its common 

associates, and so, too, are sillimanite and kyanite. Its most fre-.

0 Neues Jabrb., 1897, pt. 2. p. 156.

"Bull. Soc. min., vol. 13, p. 256, 1890. See also J. W. Mellor, Jour. Soc. Chern. Ind., 

vol. 20, p. 375, 1907.

c The reported alteration of kyanite into steatite is most questionable. Probably a 

compact muscovite (damourite) bas been mistaken for talc.

<l Bull. Geol. Soc. America, vol. 1, p. 559, 1889.
METAMOEPHIC BOCKS. 529

quent 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 

H.,FeAl2Si07 ; but that of ottrelite is not certain. The best evidence goes to show that the two minerals are alike in type, except 

that chloritoid is an orthosilicate, and ottrelite a trisilicate. On this 

supposition the two formulae become

AlCXFe.Si04 .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 ALMgSi00 , 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," chlorite is derived 

from ottrelite, and the latter mineral was one of the last to form. 

In the Belgian phyllites, studied by J. Gosselet,6 mica sometimes 

replaces ottrelite. The formation of ottrelite after the other minerals of the schists was also noted by W. M. Hutchings," in a 

sericite-ottrelite-ilmenite phyllite from Cornwall, and by J. E. 

Wolff (Z in a rock found at Newport, Rhode Island. In a collection 

of rocks from the Transvaal, J. Gotz e 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 f has reported them from the lie de Groix, France ; a garnetchloritoid-quartz schist from Japan has been described by B. Koto ; ' > 

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

0 Am. Jour. Sci., 3d ser., vol. 44, p. 270, 1892. 

6 Ann. Soc. g6ol. du Nord, vol. 15, p. 185. 

°- Geol. Mag., 1889, p. 214. 

d Bull. Mus. Comp. Zool., vol. 16, p. 159, 1890. 

» Neues Jahrb., Beil. Bd. 4, p. j.43, 1886. 

'Ann. Soc. gdol. du Nord, vol. 11, p. 18, 1884. 

a Jour. Coll. Scl. Japan, vol. 5, p. 270, 1893.

14399 Bull. 330 OS 34
530 THE DATA OF GEOCHEMISTRY.

F. Zirkel,* 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.

Analyses of andalusite and chloritoid rocks.

A. Andalusite scliist, Mariposa County, California. Analysis by W. F. Hillebrand. 

Described by H. W. Turner, Seventeenth Ann. Rept. U. S. Geol. Survey, pt. 1, p. 691, 

1896. Contains quartz, biotite, andalusite, sericite, and minor accessories.

B. Chiastolite schist, Mariposa County, California. Analysis by G. Steiger. Described 

by Turner, Bull. U. S. Geol. Survey No. 150, p. 342, 1898. 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, p. 105, 1905. 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 I-Iillebrand. Described by 

O. A. Derby, Am. Jour. Sci., 4th ser., vol. 7, p. 343, 1899. Consists mainly of kyanite, 

chlorite, sericite, quartz, and rutile.

F. Sillimanite schist, San Diego County, California. Analyzed and described by 

Schaller, Bull. No. 262, p. 98, 1895. 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. Ottrelite schist, Montherm^, Belgium. Analyzed by C. Klement, described by A. F. 

Renard. Kenard's memoirs on the phyllites of the Ardennes (Bull. Mus. roy. hist. nat. 

Belgique, vol. 1, p. 212, 1882; vol. 2, p. 127, 1883; vol. 3, p. 230, 1884) 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.

SiOi... ......... ; 

A12O 3 - ...............................

FeO ................................

MgO..........>......................

CaO. ................................

Na2O. ...............................

K20... ..............................

H20-. ..............................

HZO+. ..............................

TiOs. ................................

ZrOj.................. ...............

c....................................

SOs-- ................................

S. ...................................

F. ................................... ci..................... ...............

pso5 . ................................

MnO. ................................

.BaO. ................................

SrO..................................

(NiCo)O ............................

FeS2 . ................................

A.

64.28

17.28

1.10

5.34

2.57

1.19

.91

2.93

. .20

2.72

.65

.43

.27

09

.10

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

.15

.04

100.46

C.

65.10

17.77

1.95

3.29

1.43

1.38

2.25

2.45

.47

2.49

.72

1.21

.03

.12

.14

100.80

D.

57.18

34.10

.54

.28

.10

.63

.39

2.57

.69

2.02

.66

.02

. .53

.04

.28

100.03

E.

38.32

28.16

2.24

4.02

12.04

.32

.16

1.11

.55

7.46

4.93

.09

trace

trace?

.47

.16

.04

100.07

F.

75.54

18.65

.35

.06

.03

none

1.10

3..67

.48

.06

. .10

100.04

G.

34.92

32.31

10.21

8.46

.36

2.12

1.87

} 5.29

3.37

.23

100.27

H.

51.93

27.45

2.01

o in

.18

.79

1.60

} 3.92

.92

.57

99.72

Lehrbuch der Petrographie, 2d ed., vol. 3, pp. 282, 294, 303-306.
METAMOEPHIC BOCKS. 531

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, 

with varying accessories. A paragonite schist contains the soda mica, 

paragonite, instead of the commoner muscovite. A shale passes into 

a slate; in that fine scales of mica develop, forming a phyllite, and 

with more complete recrystallization a mica schist is produced. Mica 

schists also, originate from the alteration of a granitic detritus consisting of quartz and feldspar,0 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 ASCII tney, x Vermont. Analyzed by W. F. Hlllebrmid. 

Described by K. A. Daly in Bull. U. S. Geol. Survey No. 209, .1908.

B. Sericite schist, Ladiesburg, Maryland. Analyzed by G. Steiger. Described by 

W. S. Bayley in Bull. U. S. Geol. Survey No. 150, p. 317, 1898.

0. Sericite schist, Marquette region, Michigan. Analysis by S.teiger. Described by 

C. 11. Van Hise and W. S. Bnyley, 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. Sinyth, Mon. U. S. Geol. Survey, vol. 36,. p. 274, 1898. Contains 

biotite, quartz, some microcline, and magnetite.

E. Mica schist, near Gunflint Lake, Minnesota. Analyzed by T. M. Chatard. Contains biotite, quartz, feldspar, (?) and pyrite, as reported by Van Hise.

F. Feldspathic mica schist, Mariposa' County,. California. Analyzed by Hillebrand. 

Described by H. W. Turner, Seventeenth Ann. Kept. U. S. Geol. Survey, pt.' 1, p. 691, 

1896. Contains quartz, feldspar, biotite, muscovite, apatite, and specular iron.

SiOa................. .....................

A12 03 . ....................................

Fe203 . ...................................

FeO. ....................................

MgO... ...................................

Na2O. ....................................

K2O. ....................................

H aO .....................................

HaO-t........... ...........................

Ti02 . .....................................

ZrOa... ...................................

C02 .... ...................................

FsOi. .....................................

SO3 . ......................................

F. ........................................

MnO.....................................

BaO.......... ............................

SrO. .....................................

Li 2 0. .....................................

C. ...........:............................

FeS2 . .....................................

A. 

90.91

4.18

 32

1.27

.37

.22

.77

.58

.06

.74

.28

.02

.18

.05

.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

9 70

.72

-

.02

99.44

E.

64.77

14.45

1.84

. 4.54

2.34

2.33

1.37

5.03

.07

1 Q9

.60

.41

.20

60

100.58

F.

70.40

14.70

.65

2.57

1.47

1.63

3.17

3.46

19

.fll

.51

.05

.08

.09

.15

~

100.03

" See C. R. Van Hise, Bull. Geol. Soc. America, vol. 1, p. 206, 1899, on schists from 

the Black Hills.
532 THE DATA OF GEOCHEMISTRY.

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,® 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 Hampshire, as

described by G. W. Hawes.6 Here there are seven well-defined 

zones, as follows:

1. Argillitic mica schist, chloritic.

2. Argillitic mica schist, biotitic.

3. Tourmaline horustone.

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.

« See ante, Chapter VIII.

" Am. Jour. Sci., 3d ser., vol. 21, p. 21, 1881.
METAMORPHIC BOCKS. 533

Analyses of granite and mica .schist near contact, Mount Willard.

A The normal Albany granite. 

B. Porphyry, 3 feet from contact. 

C. Porphyry,^ 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.

A12 03 . ...............................

FoO.. ...............................

MgO..... ............................

CaO. ................................

NasO ................................

KjO.. ...............................

H»O.....................'............

TiOj.................................

B,03 ........ .........................

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

4fl

no

101.06

C.

71.07

12.34

2.25

4.92

.19

55

2.84

5.53

.72

97

100.68

D.

16.84

1.97

5.50

1.71

.37

1.76

.56

1.31

1 02

2.90

or:

19

100. 78

E.

67.88

14.07

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 90

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 PI, as given by Hawes, presents 

a still clearer picture to the mind of the changes which have occurred:

Mineralof/ical composition of tourmaline rocks and mica schist, Mount Willard.

Biotite ..............................................

D.

50.03

1.94

2.86

E.

50.82

i.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

IT.

30. 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.
534 THE DATA OF GEOCHEMISTRY.

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 a may perhaps serve as well as any. He defines gneiss as a " lam- .- 

inated 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 & 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 theBlack Forest, H. E-osenbusch ° found coaly particles which contained 

nitrogenous matter, undoubtedly derived from organic substances. 

A convenient aid to ndmenclature is that offered by Rosenbusch,* who 

calls gneiss of igneous origin " orthogneiss," and that of sedimentary H 

origin " paragneiss." There are also descriptive names of the ordi- ,H 

nary character, which indicate mineralogical peculiarities. Chlorite > 

gneiss, cordierite gneiss, tourmaline gneiss, garnet gneiss, epidote j 

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 genet- 5' 

ically, as pelite gneiss, psammite gneiss, arkose gneiss, etc., according V 

to the derivation of the rock from shaly, sandy, or arkose materials. J

The following analyses of gneiss, with the exception of the Canadian example, were made by the chemists of the United States 

Geological Survey:

Analyses of gneisses.

A. Sedimentary gneiss, St. Jean de Matha, Quebec, Canada. Analysis by N. N. Evans. ";"' 

Described by F. D. Adams, Am. Jour. Sci., 3d ser., vol. 50, p. 67, 1895. Adams gives 

several other analyses of gneisses.

0 Handbook of Rocks, 3d ed., p. 123.

6 Bull. Geol. Soc! America, vol. 7, p. 122, 1895.

c Mitth. Gr. badisch. geol. Landesanstalt, vol. 4, Heft 1, 1899. 'L.

* Blemente der Gesteinslehre, 2d ed., p. 484.
METAMORPHIC BOOKS. 535

B. Quartz-blotlte-garnet gneiss, Port Ami, New York. Analysis by W. P. Hillebrand. 

Reported by J. F. Kemp to contain quartz, garnet, biotlte, ortboclase, some plagloclase, 

and zircon.

C. Average sample of mica gneiss, near Philadelphia, Pennsylvania. Analysis by milebrand. Described by P. Bascom, Maryland Geol. Survey, Cecil County volume, p. 116, 

1902. Contains quartz, muscovlte, 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, p. 697, 1895. 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, p. 670, 1895.

F. Biotlte gneiss, Upper Quinnesec Falls, Menomlnee River, Michigan. Analysis by 

R. B. Riggs. Described by G. H. Williams, Bull. U. S. Geol. Survey No. 62, p. 119, 1890. 

Contains blotite, 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, p. 358, 1898. Contains quartz, plagioclase, and pyroxene, with accessory biotite, garnet, pyrite, and magnetite.

SiOs............................

AhOs.- ..'..- ...................

'FfttOt... .......................

FeO....... .....................

MgO. ..........................

CaO. ............................

NasO.... ......................

KjO..... ........................

H3 0-. .........................

 SLtQ'-^.:. .......................

TlOj.. .........................

ZrOa ...........................

cos ... .........................

P20i... ........................

S...... .........................

Fe7 S8 ...........................

FeS3 .... .......................

CriOt..... .....................

NiO............................

MnO. ..........................

BaO.. .........................

SrO. ...........................

LijO. ..........................

A.

61.96

19.73

4.60

1.81

.35

.79

2.50

[ 1.82

1.66

4.33

99.55

B.

65.09

16.37

.93

5.64

2.40

2.40

3.31

1.93

.13

.58

.93

.01

. .07

.11

. .03

trace

.16

.03

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

.20

99.87

D.

48.92

16.57

4.21

9.18

5.98

. 9.69

2.47

1.56

} .68

100. 26

E. *

78.28

9.96

1.85

1.78

.95

1.68

2.73

1.35

.12

.83

.70

.11

.08

.02

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

1 QQ

1.96

.55

I A1

I " 43

3.73

98.87

In a broad way the general order of change from' clay to slate, 

shale, and metamorphic schists is well shown by a series of averaged 

analyses compiled by C. R. Van Hise.° The analyses chosen 'for 

combination were all of pelitic material.

Average analyses of clay, shale, slate, and schist.

A. Average of twelve analyses of clays and soils.

B. Average or composite analysis of seventy-eight shales.

C. Average of twenty-two analyses of slates.

D. Average of five analyses of schists.

" Treatise on metamorphlsm : Mon. U. S. Geol. Survey, vol. 47, pp. 890, 891, 896, 1904. 

The data are all to be found in Bull. U. S. Geol. Survey No. 228 ; the shale average on 

p. 21.
536 THE DATA OF GEOCHEMISTKY.

SiOs..... ..............................................;.......

A12 03 ..........................................................

FezOs ..........................................................

FeO............. ..............................................

MgO.. .........................................................

CaO......... ..................................................

NasO ..........................................................

K2O..... ......................................................

HsO..... ......................................................

TiOi.. .........................................................

COs.. ..........................................................

P&t .............................;.. ...........................

so3 ...^......... ...............................................

Cl.... .........................................................

F... .................. ...............................I.... .....

MnO ..........................................................

SrO........ ........................... :,.. ....................

BaO.. .........................................................

Li20 ...........................................................

FeSs...........................................................

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

4.03

2.46

2.45

3.12

1.31

3.25

5.02

.65

2.64

.17

. .65

.05

.81

100.46

C.

61.90

16.54

2.73

3.63

2.99

1.07

2.57

3.15

3.84

.82

.59

.04

.03

.01

.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

. .03

 .07

.03

.05

.58

99.99

In these figures, reading from clay to schist, we see a steady loss 

of water and of carbon dioxide. The latter has been gradually 

replaced by silica, and silica has also increased in proportion by its 

assumption as a cementing substance. Ferric iron, furthermore, is 

partly reduced to the ferrous state, and there is an apparent -gain in 

alumina, which may be partly real, and so far due to cementation. 

The averages represent too few individual analyses to warrant any 

elaborate discussion of them, but they serve to illustrate the general 

tendency of the metamorphic processes.

. METAMORPHIC .LIMESTONES.

1 The metamorphism of limestone is effected by a variety of processes 

which are quite distinct in many particulars from those outlined in 

the preceding pages. A pure or relatively pure limestone may 

recrystallize into a compact marble, as shown in the chapter upon 

the sedimentary rocks. If it contains magnesium carbonate, dolomite is produced; and the presence of iron may determine the formation of mixed carbonates, such as ankerite or mesitite. These 

changes are of the simplest character and call for no further discussion now.

But pure limestones are relatively rare. Sandy or argillaceous 

impurities are generally present, and also silicates produced by 

reactions within filtrating 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
METAMORPHIC ROCKS; 537

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 Car.rara 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 geological, significance. E. T. 

Alien and W. P. White ° 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 Avhat has been called the " geological thermometer."

The recrystallization of a sedimentary limestone containing limonitic impurities or hydroxides of aluminum will obviously produce 

inclusions of magnetite, hematite,, or corundum. Magnetite has often 

been identified in crystalline limestones, and similar occurrences of 

corundum are not uncommon. The Burmese rubies, for example, are 

found in crystalline limestone, and. so, too^ are the red and blue 

corundum! 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 appear: 

ance 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 Mon- 

/oni in the Tyrol. 6 Metamorphosed limestone with inclusions of

o Am. Jour. Sci., 4th ser., vol. 21, p. 89, 1906. The memoir is prefaced by' a note 

from G. F. Becker, who points out the geological bearing of the observations.

* 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.
538 , . " THE DATA OF GEOCHEMISTEY.

this class are common; for instance, in a belt extending from southwestern Maine to central Massachusetts. From two points in this 

belt, at Eaymond and Phippsburg, Maine, crystallized anorthite has 

also been identified by analyses made in the laboratory of the United 

States Geological Survey.* The other feldspars as well, albite, orthoclase, and the plagioclases, are known as contact minerals or inclusions in crystalline limestones,6 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. 0

In a Scottish dolomitic marble containing forsterite, tremolite, 

diopside, and brucite, J. J. H. Teall d 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 eft'ected 

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

"Bull. U. S. Geol. Survey No. 220, p. 27, 1903. Anorthite, also occurs in the marble 

of Monzoni, in the Tyrol. See G. vom Rath, Zeitschr. Deutsch. geol. Gesell., vol.. 27, 

p. 379, 1875.

 " See, for example, G. Linck, Neues Jahrb., 1907, p. 21, on orthoclase from the dolomite of Campolongo.

c In Mon. U. S. Geol. Survey, vol. 46, p. 221, 1904, W. S. Bay ley-described a talcose 

schist from the Aragon iron mine, Michigan, which was probably derived from a dolomite. An analysis of it, by G. Steiger, is given, and also its mineralogical composition.

d Geol. Mag., 1903, p. 513. .
I METAMOEPHIC ROCKS. 539

\

predazzite of the Tyrol.* It may be noted here that certain of the 

' Adirondack limestones are regarded by J. F. Kemp 6 as having been

_v originally siliceous dolomites, in which the silica and magnesia have 

segregated as pyroxene. In northern New Jersey, according to L. G.

\ Westgate,0 a quartz rock and a quartz-pyroxene rock have been 

formed by the. metamorphism of limestones.

In addition to the minerals already named, the crystalline limestones contain many other less important species. Apatite, fluorite,

.,. rutile, perofskite^ titanite, dysanalyte, and zircon are among them. 

By.the reduction of sulphates, a considerable number of sulphides 

may be formed. At Carrara, for instance, G. d'Achiardi d found 

realgar, orpiment, sphalerite, pyrite, arsenbpyrite, 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

I 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 signifi-

 , cance and are not often made. Three examples from the silicate side 

of the group may serve to illustrate the variety of composition:

Analyses of metamorphic silicate rocks.

i A. Wollastonite gneiss, Amador County, California. Analysis by W. P. Hlllebrand.

i Described by H. W. Turner, Seventeenth Ann. -Kept. U. S. Geol. Survey, pt. 1, p. 521,

1896. Consists mainly of wollastonite, but garnet, quartz, and titanite are also present.

B. Frehnite rock, Black Forest, Germany. Analysis by C. Schnarrenberger. Described 

by H. Rosenbusch, Mitth. 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 Rosenbusch, 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 sodapotash mica, and 15 per cent hornblende.

0 See ante, p. 489.

6 Bull. Geol. Soc. America, vol. 6, p. 241, 1894. In the same volume, p. 263, C. H. 

Smyth discusses another group of Adirondack limestones which were metamorphosed 

along contacts with gabbro.

c Am. Geologist, vol. 14, p. 308, 1894.

"Atti Soc. toscana sci. nat, Pisa, vol. 21, 1905.

0 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, p. 197, 1904. For the Ceylonese localities, see A. K. Coomfira-Swainy, Quart. Jour. Geol. Soc., vol 58, p. 399, 1902. J. F. 

Kemp and A. Hollick have described the crystalline limestones of Warwick, New York, 

in Ann. New York Acad. Sci., vol. 7, p. 644, 1893.
540 THE DATA OF GEOCHEMISTRY.

SiOs. .....................................................................

AhOs . ...................................................................

FeaO3 ......................................................................

FeO. .....................................................................

MgO..... ................................................................

CaO......................................................................

NaaO .....................................................................

K2O ......................................................................

H20. ....... ..............................!...............................

COs...... ................................................................

MnO .....................................................................

A.

50.67

6.37

.31

.50

.58

40.34

.14

.22

.39

.20

.52

100.24

B.

50.65

19.54

3.34

3.92

16.11

3.91

.84

o3.10

100.41

C.

41.01

18.50

6.57

11.06

11.02

10.31

.48

' .31

1.18

100.44

Loss on ignition.
CHAPTER XV.

t

METALLIC ORES. 

DEFINITION.

From a strictly scientific point of view, the terms metallic ore and 

ore deposit have no clear significance. They are purely conventional

^ expressions, used to describe those metalliferous minerals or bodies 

of mineral having economic value, from which the useful metals

^ can be advantageously extracted. In one sense, rock salt is an ore of 

sodium, and limestone an ore of calcium; but to term beds of these 

substances ore deposits would be quite outside of current usage.

In the previous chapters of this work several forms of ore deposit 

have been described; and therefore the present chapter is in some 

measure supplementary. Its purpose is to deal with the subject more 

fully, and especially to give details concerning certain groups of ores 

which have been left out of account hitherto. Little has been said 

so far of the sulphides, and these are among the most important of

"i 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.0 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

i 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

v . 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

0 For recent papers and works on this subject, see P. PoSepny, Trans. Am. Inst. Min. 

Kng., vol. 23, p. 197, 1893. .T. H. L. Vogt, idem, vol. 31, p. 125, 1901. L. De Launay,

- Contribution a l'e"tude des gites metal 1 if eree, Paris, 1897. J. P. Kemp, Ore deposits of 

the United States and Canada, New York, 1900. W. H. Weed and .T. E. Spurr, Eng. and 

Min. .Tour., vol. 75, p. 256, 1903. 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 I-Iise, Treatise on metamorphism, Mon. 

U. S. Geol. Survey, vol. 47, chapter 12, 1904. W. H. Weed, Trans. Am. Inst. Min. Eng., 

.vol. 33, p. 717, 1903. C. R. Keyes, idem, vol. 30, p. 323, 1900. G. Gurlch, Zeitschr. 

prakt. Geol., 1899, p. 173.

641
542 THE DATA OF GEOCHEMISTKY. -

beds of magnetite or hematite are derived. Some ore bodies are residues from the concentration of limestones; others represent meta- 4 

somatic 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 A 

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 indi- . 

vidual metals; but some general considerations require attention first.

SOUKCE 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. In igneous rocks of some sort the metals 

were once diffused, and their presence in eruptive material is easily 

detected. G. Forchhammer a in a series of rock samples found traces 

of silver, copper, lead, bismuth, cobalt, nickel, zinc, arsenic, anti- _y 

mony, and tin, to say nothing of the commoner metals, iron and man- J 

ganese. 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 6 - 

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 confents by lateral leaching from adjacent rocks. This theory, 

however, was subjected to much criticism by A. Stelzner, F. Posepm-,

" Pogg. Annaleh, vol. 95, p. 60.

6 Untersuchungen liber Erzgiinge, Wiesbaden, 1882 and 1885. See also Neues Jahrb., 

1878, p. 291, on copper, lead, cobalt, and antimony in basalt.
METALLIC ORES. . 543

and others,0 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. 

Daubree & found determinate quantities of arsenic and antimony in 

basalt namely, 0.01 gram of As and 0.03 of Sb to the kilogram. 

The same metals, together with lead and copper, were detected by 

G. F. Becker c in the fresh granites near Steamboat Springs, Nevada. 

In the porphyries of Leadville, Colorado, W. F. Hillebrand (l 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 sometimes present in traces, was generally not found. Traces of silver in 

diabase and diorite are reported by G. F. Becker c near Washoe, 

Nevada, and in the quartz porphyry of Eureka J. S. Curtis f found 

both gold and silver. Silver, according to S. F. Emmons, flr 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 h carried silver to the extent of 1 part in 83,600, and 

ash from Tunguragua i 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 * 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 k 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, p. 64^, 1879, and rejoinder by 

F. Sandberger, idem, vol. 23, p. 350, 1880. P. PoSepny, Trans. Am. Inst. Min. Eng., 

vol. 23, pp. 247-254, 1893.

»Compt. Rend., vol. 32, p. 827, 1851.

0 Mon. U. S. Geol. Survey, vol. 13, p. 350, 1888.

d Idem, vol. 12, pp. 591-594, 1886.

0 Idem, vol. 3, pp. 223-227, 1882. Assays by J. S. Curtis.

f Idem, vol. 7, pp. 80-92, 1884.

o Seventeenth Ann. Kept. U. S. Geol. Survey, pt. 2, p. 471, 1896. Assays by L. G. 

Eakins.

ft Cbern. News, vol. 55, p. 17, 1887.

1 Proc. Roy. Soc., vol. 47, p. 277, 1890.

i Gazz. chirn. ital., vol. 36, pt. 2, p. 797, 1906.

* Missouri Geol. Survey, vol. 7, pp. 479-481. 1894.
544 THE DATA OF GEOCHEMISTRY. i

According to L. Dieulafait,0 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 6 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. Harri- i 

son,0 also yielded appreciable quantities of copper, 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 i 

yielded silver, from 4 to 54 grains per ton of 2,240 pounds, in aver- v 

age, 25.5 grains; and out of 29 rocks only 1 was free from gold. x| 

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 26. Copper is determined 

in exceptional cases only, but indications of its presence are fre- ' 

quently observed. 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/ a fact which is capable of more than one iiiterpreta- ^. 

tion. Such a spring may derive its contents from dispersed material^ v 

or it may rise from a segregated body of ore; its composition, there- y 

fore, merely tells us that the metalliferous compounds are more or 

less freely soluble. The true origin of the latter is not thereby 

explained.

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 e found that sulphides of iron, nickel, co-

°Ann. chim. phys., 5th ser., vol. 18, p. 349, 1879; vol. 21, p. 256, 1880. ;

6 Am. Jour. Sci., 4th ser., vol. 2, p. 424, 1896. In andesite from Lautoka, Fiji, H. S. 

Jenssen found 0.034 per cent of copper, on an average. Chem. News, vol. 96, p. 245,1907.

c Kept, on petrography of Cuyuni and Mazaruni districts, Georgetown, Demerara, 1905. 

On gold and silver in diabase, French Guiana, see E. D. Levat, Ann. mines, 9th ser., 

vol. 13, p. 386, 1898; and also in Min. Industry, vol. 7, p. 315.

d See p. 147, 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.

« Ann. chim, phys., 5th ser., vol. 18, p. 189, 1879.
METALLIC ORES. 545

bait, 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 Sb,S3 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 ° were conducted differently. The natural 

sulphides, in fine powder, were heated with water in glass tubes to 

80° during periods of thirty to thirty-two days. In a second series 

of experiments, lasting twenty-four 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 sodium sulphide

solution.

Water 

alone.

1 7Q

5.01

2 90

.025

1669 

2.075

1.5

 With 

sodium 

sulphide

2.3

nil

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.6

According to Doelter, then, sulphides may be dissolved and recrystallized from water alone. This is important, but not a complete 

indication of what occurs in nature. Natural waters, as we well 

know, are not pure, but charged with various dissolved salts, which 

exert a varying influence upon the solution of sulphides. They also 

contain carbonic acid, and sometimes also the stronger mineral 

acids; and surface waters carry dissolved oxygen. All of these, 

impurities take part in the solution, concentration, and redistribution of metallic ores, and their effects are furthermore varied by 

differences of temperature. A hot water, rising from great depths 

and free from oxygen, produces one set of changes, a cold surface 

water, highly oxygenated, acts quite differently. Direct solution of 

ores is more likely to occur in the one case, oxidation to soluble salts'

»Min. pet. Mitth., vol. 11, p. 319, 1890. Research continued by G. A. Binder, idem, 

vol. 12, p. 332, 1892.

"Still more recently O. Weigel (Nachrichten K. Gesell. Gottingen, Math. phys. Klasse, 

1906, p. 525) has determined the solubility in pure water of the sulphides of Pb, Hg, Ag, 

Cu, Cd, Zn, Ni, Co, Fe, Mn, Sn, As, Sb, and Bi. All were slightly soluble,

14399 Bull. 330 08 35
546 THE DATA OF GEOCHEMISTBY.

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. The following analyses, with one exception, are from the 

laboratory records of the United States Geological Survey. All are 

stated in terms of parts per million.

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 B407. Analyses A and B by W. P. Hillebrand. Discussed by S. F. Bmmons, Seventeenth Ann. Kept. U. S. Geol. Survey, pt. 2, p. 462, 1896.

C. Water from Alabama Coon mine, Joplin district, Missouri. Analysis' by H. N. 

Stokes."

D. Water from St. Lawrence mine, Butte, Montana. Analysis by Hillebrand.

E. Water from Mountain View mine, Butte, Montana. Analysis by Hillebrand. Contains a trace of arsenic.

F. Water from the Rothsch5nberger Stolln, Freiberg, Saxony, at its point of discharge 

into the Triebisch Valley. Analysis by Erenzel, here reduced to ionic form. Described 

by H. Muller, Jahrb. Berg. Hutt. KOnig. Sachsen, 1885, p. 185. Discharges 479 kilograms 

of ZnO daily, or 175,024 kilograms per annum."

PI

so<. ............................. .........

C03 .. .....................................

N03 .. .................................... PO«. .....................................

K...... ...................................

Na. ......................................

Li........................................

Sr. .:.................. ...................

Mg. ......................................

Al. .......................................

Fe. .......................................

Mn.. .....................................

Ni. .......................................

Co........................................

Cu. .......................................

Zn. .......................................

Cd. .......................................

Pb............... .........................

Sn. ...............:....-..................

Total C02 . ..........................'.....

A.

7.9

43.2

. 110.5

10.6

36.4

37.4

12.25

c .4

. .7

.8

.2

25.9

286.25

B.

186.40

161.70

1,513.44

1.60

198.00

719.45

2.85

146.41

1.95

177.67

1.06

3.50

.57

.02

.34

1.35

24.42

3,140.73

2,528.46

C.

2.7

6,153.2

.5

49.9

345.3

25.2

142.1

474.6

1.7

3.7

2,412.0

0 0

107.6

9,727.5

D.

13.0

2,672.0

101

39.6

132. 5

61.6

83.5

159.8

12.0

\ .5

59.1

852.0

41.1

17.0-

47.7

4,204.5

OQ 7

E.

17.7

71,053.3

1.5

6.8

41.7

S07.7

149.2

85.2

49.8

13.2

^ ^

4.6

45,633.2

411.2

67.4

117,846.0

8 0

F.

12.4

124.8

40.4

14.5

. 6.6

8.9

18.0

d231.6

a Two other analyses of zinc-bearing mine waters from the Joplin district are reported ",- 

by C. P. Williams, Am. Chemist, vol. 7, p. 286, 1877. . >

6 For other analyses of mine waters see J. A. Phillips, Phil. Mag., 4th ser., vol. 42, t 

p. 401, 1871. A. Schrauf, Jahrb. K.-k. geol. Reichsanstalt, vol. 41, p. 35, 1891. A. C. ' 

Lane, Proc. Lake Superior Mining Inst., vol. 12, p. 97, 1906. A few others ha.ve already 

been cited in the chapter on- mineral springs. F. Po§epn# (Trans. Am. Inst. Min. Eng., , 

vol. 23, p. 240, 1893) has tabulated the occurrences of Sn, Sb, Cu, and As in mineral 

waters.

a A1203 + P205, 0.8 per million.

"244.9 in the original.

Analysis A represents vadose or superficial water; B, water from 

the deep circulation. The difference in concentration is remarkable. 

Water E 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.
METALLIC ORES. 547

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.* 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,6 and 

need not be especially considered here. The arguments are mainly 

physical and geological, and have only partial relation to chemistry. 

These waters, ascending, descending, or lateral secreting, tend to

"See L. De Launay, Contribution :\ I'etude des gites mctalliferes, p. 0, 1897; arid 

F. Pogepny, Trans. Am. Inst. Min. Eng., vol. 23, p. 206, 1893. J. H. L. Vogt' (Trans. 

Am. Inst. Min. Eng., voL 31, p. 125, 1901) and also C. R. Van Hiso (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, p. 364,'1906.

"Op. cit., chapter 12.
548 THE DATA OF GEOCHEMISTRY. J

gather into trunk channels, in which, sooner or later, some of the 

substances held in solution are deposited. Ore bodies are thus 4 

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 V 

they need not be further described. Once in a while concentra- v 

tions of heavy metals are produced, and in most cases, but not invariably, they appear in association, with rocks of igneous origin/1 This v 

association seems to be fundamentally important, so far as the metal- ^ 

liferous 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 4. 

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 en- ~\ 

ters 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 t 

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 varia- -^ 

tions 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. 6 Aqueous solutions take ' 

part in some of these changes, penetrating the walls of the contact _ 

and bringing about metasomatic replacements. 0

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

" See Beck's work on ore deposits. Also papers by J. F. Kemp, Trims. Am. lust. Min. 

Eng., vol. 81, p. 169, 1901 ; vol. 38, p. 699, 1908. J. E. Spurr, idem, vol. 33, p. 288, 

1903. W. I-I. Weed, idem, vol. 33, p. 715, 1903 W. Lindgren, idem, vol. 30, p. 578, 1900.

6 See W. Lindgren, Trans. Am. Inst..Min. Eng., vol. 31, p. 226, 1901.

c Lindgren, idem, vol. 30, p. 578, 1900. These contact deposits and metasomatic alterations are fully described by Lindgren, who gives excellent summaries of the earlier 

literature. A later paper on ore deposition by Lindgren appears in Econ. Geol., vol. 2, 

p. 105, 1907.
METALLIC ORES. . 549

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 heavAr 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 heavj'- metals, however, are not laid down as chlorides or fluorides except in rare instances; but in other forms chlorine and fluorine 

haA^e 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 bo 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 Ave assume to have been otherAvise formed. The phenomena 

must also vary as the magmatic Avaters 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 VICAV, Avhich decompose sulphides at first and generate actively solvent solutions that come into play later. That is, a 

Avater containing alkaline carbonates and free carbonic acid should 

decompose the sulphides at great depths under the conditions there 

existing of high temperature and pressure.
550 THE DATA OF GEOCHEMISTRY.

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 fake place, and they become thereby concentrated at the-margin of the cooling mass. The product of 

concentration may itself appear as a large and distinct ore body, like 

the Norwegian pyrrhotites, or it may be relatively trivial; but in

either case a first step has been taken.

Upon this primary concentration the circulating waters may act, 

and indeed have been acting from the instant that cooling began. 

Obviously, the waters which first operate are either those which were 

occluded in or generated from the rising magma or which it encountered earliest in the course of its upward movement. These, therefore, are ascending waters, whatever their previous history may have 

been. Their condition at first is that of highly superheated and 

compressed steam, for they are above the critical temperature of water 

and can not liquefy until they have partly cooled. Below 365° they 

become possibly liquid and heavily charged with matter dissolved 

from the magma and the adjacent rocks. Solids and gases are both 

dissolved, and the ascending solution, slowly cooling and mingling 

with other solutions as it rises, gradually deposits its burden. Its 

channel becomes filled with various minerals, ores, and gangues, and 

thus a second stage in the concentration is completed.
METALLIC ORES. ' 551

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," form a 

mutual solution with glass. But how'it will act with molten rock 

under pressure, what sort of a solution it will then (develop, we do 

not know. It is fair to infer that the reactions will be both energetic 

and complex, and that supersaturated solutions are likely to be produced ; but the waters which ultimately rise to the surface as thermal 

springs are at moderate temperatures and have lost much of their 

load. Furthermore, they have been modified by other waters, and 

reactions may have occurred of which no certain trace remains. If 

organic matter has reached .the solutions at any point, sulphates 

must have undergone reduction to sulphides, and the latter 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.6

In the first place, the surface waters, charged with oxygen and 

carbonic acid, attack the outcrop of ores, oxidizing them more or 

less completely to sulphates. : Sulphuric acid or acid salts are formed 

at the same time, which assist in the decomposition of the adjacent 

rocks. That decomposition is more than ordinarily extensive in the 

vicinity of metalliferous veins; and the rocks therefore acquire a 

higher degree of permeability to the percolating waters.

" See ante, p. 244.

6 For a summary of these alterations, see R. A. F. Penrose, Jour. Geol., vol. 2, p. 288, 

1894. Also De Launay's memoir, previously cited.
552 THE DATA OF GEOCHEMISTEY.

The sulphates thus formed differ in solubility, and are furthermore 

affected by other substances contained in the waters. Gold is left in A 

the free state, in which condition it may partly dissolve in ferric 

solutions, but for the most part remains unchanged. Silver is con- r 

verted 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 surrace, 

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, arid 

cerussite will appear. Oxides of lead and copper may also be pro- { -

duced, 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.0 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. ('

In this bare outline of what may be supposed to happen in the -4- 

formation of a metalliferous vein, details have been purposely left 

out of account. Their consideration naturally follows in the succeeding pages, in which the metals are studied separately. 2*

0 On secondary enrichment, see W. H. Weed, Bull. Geol. Soc. America, vol. 11, p. 179, J 

1899. S. F. Emmons, Trans. Am. Inst. Min. Eng., vol. 30, p. 177, 1900, and Weed, idem, 

p. 424. J. F. Kemp, Econ. Geol., vol. 1, p. 11, 1905. On enrichment by ascending waters, 

see Weed, Trans. Am. Inst. Min. Eng., vol. 33, p. 747, 1903. ^

b The ores of iron, manganese, and aluminum have been sufficiently described in the 

chapters upon rock-forming minerals, rock decomposition, and the sedimentary rocks.
METALLIC OEES.

GOLD.«

553

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.6 A notable amount of gold is now recovered from 

copper ores, during the electrolytic refining of the copper. .A. Liversidge c found traces of gold in rock salt from several localities, in 

quantities of about 1 to 2 grains per ton. F. Laur,d 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 e reports it in a Mexican granite, 

embedded in quartz and feldspar. W. Moricke f found visible gold 

in a pitchstone from Chile; and 0. Schiebe" 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 h found the following quantities, in milligrams per metric ton, of gold and silver. The samples 

are California!!, except when otherwise stated.

Gold anil silver in certain rocks from California, Nevada, etc. 

[Milligrams per metric ton.]

Do.............................................................................

Do.............................................................................

Do.............................................................................

Do.............................................................................

Basalt ..............................................................................

An.

104

137

115

720

1, 130

39

24

21

20

70

5

8.03

Ag.

7, COO

1,220

940

15, 430

5, 590

540

450

320

547

7,440

212

201

0 For a list of the Survey publications on gold and silver see Bull. No. 315, pp. 89-92, 

1907. ' .

6 See ante, p. 93.

 < Tour. Chern. Soc., vol. 71, p. 298, 1897.

d Compt. Rend., vol. 142, p. 1409, 1906. Also in Compt. Rend. Soc. ind. rnine'rale, SeptOct, 190G.

cAm. Jour. Sci., 4th ser., vol. 1, p. 309, 1896. Compare W. P. Blake, Trans. Am. Inst. 

Min. Eng., vol. 26, p. 290, 1896.

' Min. pet. Mitth., vol. 12, p. 195, 1891.

" Zeitschr. Deutsch. geol. Gesell., vol. 40, p. 611, 1888. For other examples see 

Stelzner-Bergeat, Die Erzlagerstiitten, pp. 69-70. See also T. Catharinet, Eng. and Min. 

.Tour., vol. 79, p. 127, 1905, on gold in the pegmatite of Copper Mountain, British Columbia. R. W. Brock (idem, vol. 77, p. 511, 1904) reports gold In British Columbian porphyries.

"Trails. Am. Inst. Minn. Eng., vol. 31, p. 808, 1901.
554 THE DATA OF GEOCHEMISTRY.

These figures suggest a very general distribution of gold in rocks 

of all kinds. J. R. Don,0 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 disstance 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,6 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 

Tocks of the persilicic type, such as granite and its metamorphic 

derivatives. I refer now to its primary occurrences. It is not rare 

in association with dioritic rocks, but in rocks of subsilicic character 

it is exceedingly uncommon. Its very general presence in quartz 

veins is testimony in the same direction, and suggests the probability 

that gold is more soluble in silicic magmas than in those richer in 

bases. The auriferous quartz veins were probably formed in most 

instances from solutions; but J. E. Spurr c 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 d and others.

The composition of native gold is variable. The purest yet found, 

from Mount Morgan, Queensland, according to A. Leibius,6 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

0 Trans. Am. Inst. Min. Eng., vol. 27, p. 564, 1897.

6 See, for example, T. W. T. Atherton, Eng. and Min. Jour., vol. 52, p. 698, 1891 ; and 

A. Williams, idem, vol. 53, p. 451, 1892. 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, p. 216, 1870.

c See papers in Trans. Am. Inst. Min. Eng., vol. 33, p. 288, 1903; vol. 36, p. 372, 1906. 

Also Econ. Geol., vol. 1, p. 369, 1906.

d Treatise on Metamorphism: Mon. U. S. Geol. Survey, vol. 47, pp. 1048-1049, 1904. 

See also J. B. Hastings, Trans. Am. Inst. Min. Eng., vol. 36, p. 647, 1906. Hastings 

regards the Silver Peak ores as deposited by ascending waters along lines of fracturing.

9 Proc. Roy. Soc. New South Wales, vol. 18, p. 37, 1884.
METALLIC OEES. 555

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 iu the laboratory of the United States 

Geological Survey.

B. Electrum, Montgomery County, Virginia. Analysis by S. Porcher, Chem. News, vol. 

44, p. 189, 1881.

C, D, E. Gold associated with native platinum, Colombia. Analyses by W. H. Seamon, 

Chem. News, vol. 46, p. 216, 1882.

P. Amalgam, Mariposa County, California. Analysis by F. L. Sonnenschein, Zeitschr. 

" Deutsch. geol. Gesell., vol. 6, p. 243, 1854. Specific gravity, 15.47. Near AuHgs.

G. Palladium gold. 0 Tngunril, Brazil. Analysis by Seamon, Chem. News, vol. 46, 

p. 216, 1882.

H. Maldonite, or " black gold," Maldon, Victoria. Analysis by R. W. E. MacTvor, 

Chem. News, vol. 55, p. 191, 1887. A,n alloy near Au2Bi.

Au __ _ ___^ _ _ _-_

Air

Cu - -. . 

Hg .- 

Pd .. _

Bi 

Fc . . . ..

A.

93.24

0.65

.11

100.00

B.

65.31

34,01

9ft

.34

100.00

C.

84.38

13.26

1.85

90.49

D.

80.12

2.27

15.84

98.23

E.

84.01

7.66

7.06

98.73

F.

39.02

00.98

100.00

G.

91.06

8.21

99.27

H.

65.12

34.88

100.00

I

0 See Wilm, Zeitschr. anorg. Chemie, vol. 4, p. 300, 1893, on palladium gold from the 

Caucasus. Also E. I-lussak, Zeitschr. prakt. Geol., 1906, p. 284, on palladium gold in 

Brazil.

The tellurides 0 containing gold are also variable in composition, 

partly because most of them contain silver, and often other metals, 

Avhich may be only impurities. Kalgoorlite and coolgardite, for example, which are tellurides of gold, silver, and mercury, are mixtures 

of the mercury compound, coloradoite, with'other species. 6 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)Te», Cripple Creek, Colorado. Analysis by W. F. Hillebrand.

B. Krennerite, (AuAg)Teo, Nagyag, Hungary. Analysis.by L. Sipcicz, Zeitschr. Kryst. 

Min., vol. 11, p. 210, 1886.

C. Sylvanite (AuAg)Teo, Grand View mine, Boulder County, Colorado. Analysis by 

F. W. Clarke, Am. Tour. Sci., 3d ser., vol. 14, p. 28G, .1877.

D. Petzite, (AuAg) 2Te, Norwegian mine, Calaveras County, California. Analysis' by 

Hillebrapd.

" For a general review of the tellurides, with references to literature, sec .T. F. Kemp, 

Min. Industry, voL 6, p. 295, 1898.

6 See L. T. Spencer, Mineralog. Mag., vol. 13, p. 268, 1903. Spencer gives a good 

bibliography of the Australian tellurides.
556 THE DATA OF GEOCHEMlSTBY.

AU _ ...: _ 

ACT

Ou_. __ 

Fe. __ 

Te __ ..

Se 

Mo __ - ____ - _ - 

Sb 

Fe203 - -

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

trace

.08

100.32

According to V. Lenher,0 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. B. Brauner,6 however, 

asserts that crystalline " polytellurides " can be formed, which dissociate upon heating, leaving the compound Au2Te as an end product. 

Theoretically, the telluride Au2Te3 should also be capable of existence.

Although gold is primarily a magmatic mineral, it is also transported in and deposited from solutions. Man}?" occurrences of gold 

indicate this fact very plainly. O. Dieffenbach," for instance, mentions gold incrusting siderite at Eisenberg, near Corbach, in Germany. 0. A. Derby A reports films of gold on limonite, from Brazil. 

A. Liversidge 6 found it in recent pyrite, which formed on twigs in 

a hot spring near Lake Taupo, New Zealand. J. C. Newbery f 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^ 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 7i in the siliceous sinter of the hot 

springs at Whakarewarewa, New Zealand. R-. Brauns * 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,^' 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.

. "Jour. Am. Chem. Soc., vol. 24, p. 358, 1902. See also R. D. Hall and V. Lenher, 

Idem, p. 919.

6 Jour. Chem. Soc., vol. 55, p. 391, 1889.

c Neues Jahrb., 1854, p. 324.

^Am. Jour. Sci., 3d ser., vol. 28, p. 440, 1884.

° Jour. Roy. Soc. New South Wales, vol. 11, p. 262, 1877. '

f Trans. Roy. Soc. Victoria, vol. 9, p. 52, 1868.

o Mon. U. S. Geol. Survey, vol. 13, p. 344, 1888.

ft Geol. Mag., 1906, p. 511.

« Chemische.Mineralogie, p. 406, 1896.

i Quart. Jour. Geol. Soc., vol. 35, p. 390, 1879.
METALLIC ORES. 557

The natural solvents of gold appear to be numerous that is, if 

the recorded experiments are all trustworthy. G. Bischof a found 

that gold was held in solution by potassium silicate, and Liversidge 6 

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 ° 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 suphides have been found by 

several authorities, notably by W. Skey/' T. Egleston,0 G. F. Becker/ 

and A. Liversidge,^ 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,'1 ferric sulphate and 

ferric chloride are both effective. P. C. Mcllhiney * 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. 1ST. Stokes/' in the laboratory of the United States Geological Survey, showed that ferric chloride and also cupric chloride 

dissolve gold easily at 200°. The reactions are reversible, and gold 

is redeposited on cooling. Ferric sulphate, according to Stokes, does 

not dissolve gold unless chlorides are also present. Perhaps the 

pseudomorpli of gold after botryogen, a basic sulphate of iron, 

described by; W. D. Campbell,fc may have originated from some solution in ferric salts.

The usual laboratory solvent for gold, aqua regia, owes its efficiency 

to the liberation of free chlorine. T. Egleston l asserts that traces of 

nitrates with chlorides in natural waters can slowly dissolve the 

metal. J. K>. Don m found that weak hydrochloric acid, 1 part in 

1,250 of water, in presence of manganese dioxide, would take gold into 

solution. R. Pearce n heated gold and a solution containing 40 grains 

of common salt to the gallon, with a feAv drops of sulphuric acid and 

some manganese dioxide, and obtained partial solution. T. A. Rickard ° treated a rich Cripple Creek ore, which contained manganic

0 Lehrb. chem. phys. Geol., 2d ed., vol. 3, p. 843.

6 Proc. Roy. Soc. New South Wales, vol. 27, p.. 303, 1893.

« Min. pet. Mitth., vol. 11, p. 328, 1890.

d Trans. New Zealand Inst, vol. 3, p. 216, 1870; vol. 5, p. 382, 1872.

'« Trans. Am. Inst. Mln. Eng., vol. 9, p. 639, 1880-81.

'Am. Jour. Sci., 3d ser., vol. 33, p. 207, 1887.

Troc. Roy. Soc. New South AVales, vol. 27, p. 303, 1893.

ft Ani. Jour. Sci., 2d ser., vol. 26, p. 51, 1858.

* Idem, 4th ser., vol. 2, p. 293, 1896.

i IScon. Geol., vol. 1, p. 650, 1906.

fc Trans. New Zealand Inst., vol. 14, p. 457, 1881. Campbell's observation needs to be 

verified. The specimen was found in the Thames gold field, New Zealand.

1 Trans. Am. Inst. Min. Eng., vol. 8, p. 454, 1879-80.

m Idem, vol. 27, p. 564, 1897. According to Don, ferric salts are not effective solvents 

for gold.

"Idem, vol. 22, p. 739, 1893.

o Idem, vol. 26, p. 978, 1896.
558 THE DATA OF GEOCHEMISTEY.

oxides, with a solution of ferric sulphate, sodium chloride, and a little ^ 

sulphuric acid, and practically all of the gold dissolved. On im- >- 

mersing in this solution a fragment of black, carbonaceous shale, the 

gold Avas 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,* 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.

The experiment by Kickard 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.

Gold is also thrown out of solution by ferrous salts, by'other metals, 

and by many sulphides, especially by pyrite and galena. 6 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,0 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. v

SILVER/' .

 -i

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 e found it in rock salt, seaweed, and oyster shells, while . W. N. Hartley and H. Eamage f 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

«Jour. Am. Chern. Soc., vol. 26, p. 550, 1904.

6 See C. Wilkinsou, Trans. Roy. Soc. Victoria, vol. 8, p. 11, 1866. W. Skey, Trans. > 

New Zealand lust., vol. 3, p. 225, 1870 ; vol. 5', pp. 370, 382, 1872. A Liversidge, Proc. 

Roy. 'Soc. New South Wales, vol. 27, p. 303, 1893.

c Jour. Am. Chem. Soc., vol. 24, p. 355, 1902. Also R. D. Hall and V. Lenher. idem, ' 

p. 919.

d For a list of the Survey publications on gold and silver see Bull. No. 315, pp. 89-92, 

1907. .

e Jour. Chem. Soc., vol. 71, p. 298, 1897.

f Idem, vol. 71, p. 533, 1897.
METALLIC ORES. 559

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. In the Lake Superior copper mines silver is often embedded in 

native copper, each metal being nearly pure.

In most cases native silver is a secondary mineral. It is often 

found in gossan, and K. Beck" mentions films of silver upon the 

scales of fossil fishes from the Mansfeld copper shales. According 

to J. H. L. Vogt l' 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 th$ 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.c T. A. Kickard (l 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.6 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

° Ore Deposits, Weed's translation, p. 371. 

"Zeitschr. prakt. Geol., 1899, pp. 113, 177. 

0 Ann. chim. phys., 3d ser., vol. 32, p. 140, 1851. 

"Trans. Am. Inst. Min. Eng., vol. 26, p. 978, 1896.

" See G. Bischof, Lehrb. chem. phys. Geol., 2d ed., vol. 3, p. 856. Also J. Margottet, 

Compt. Rend., vol. 85, p. 1142, 1877.
560 THE DATA OF GEOCHEMISTKY. ^

ferric sulphate, a reaction which has recently been studied by H. N. 

Stokes a in the laboratory of the United States Geological Survey. < 

The reaction, 2Ag-fFe2 (SO4 ) 3 =Ag.,SO4 +2FeSO4 , 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.&

The natural arsenides, antimonides, and bismuthides of silver are 

imperfectly known. An arsenide, Ag3As, was described by H. Wurtz," 

under the name huntilite. "Wurtz also reported an antimonide, 

animikite, Ag9Sb. Both minerals were found in the Silver Islet 

mine, Lake Superior. The commoner antimonide, dyscrasite, varies 

from Ag3 Sb to Ag0Sb. The bismuthide, chilenite, is perhaps Ag6Bi. T 

All of these minerals need careful study, especially from a synthetic I 

point of view.

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 d 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 e * 

obtained it by the action of hydrogen sulphide upon silver chloride 

at high temperatures. J. Margottet f 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 a obtained the crystallized sulphide by 

the same process. F. Eoessler /l crystallized argentite and the selenide 

from solution in molten silver, and the selenide also from fused bis- r 

muth. C. Geitner,4 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/ 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 decom- /- 

position of the sulphocyanate yields hydrogen sulphide, which is the 

actually effective reagent. Finally, W. Spring fc found that silver

"Econ. Geol., vol. 1, p. 649, 1906.

6 System of Mineralogy, 6th ed., p. 20.

« Eng. and Min. Jour., vol. 27, pp. 55, 124, 1879. '

d Dry hydrogen sulphide does not attack silver.

"Compt. Rend., vol. 32, p. 825, 1851.

t Idem, vol. 85, p. 1142, 1877.

o Ann. chim. phys., 3d ser., vol. 55, p. 147, 1859.

h Zeitschr. anorg. Chemie, vol. 9, p. 31, 1895.

1 Liebig's Annalen, vol. 129, p. 358, 1864.

i Zeitschr. Kryst. Min., vol. 17, p. 497, 1890.

*Ber. Deutsch. chem. Gesell., vol. 16, pp. 324, 1002, 1883; vol. 17, p. 1218, 1884. 4.
METALLIC OKES. . 561

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 solution, and the sulphide is formed. Its crystallization, which is accelerated by the laboratory methods,.is presumably a question of time, 

aided by the slight solubility of the compound. The last remark, 

obviously, applies to many other sulphides also. The reduction of 

sulphate solutions by organic matter is another probable mode of 

generation.

It has already been shown that argentite is easily reduced to silver. Indeed, silver sulphide is the most readily reducible, that is, 

the least stable, of all the commoner sulphides. This is illustrated 

by its heat of formation, which is low compared with that of other 

sulphides. The following data, giving heats of formation from solid 

metal and solid sulphur, are furnished by Julius Thomsen.a The 

figures are for small calories.

Heats of formation of various sulphides.

FbS ____________-__.__._______.. -_ ___.__ 20, 430

. Gu,S _______ __-----_____-__ _-_ ' 20, 270

HgS..----__-_____________-__._____._..____ 16,890

Ago S________-________________________________ _ 5, 340

On the other hand, silver is precipitated from its solutions by 

pyrite, chalcopyrite, galena, and other sulphides.'' H. N. Stokes,6' 

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 E. 

Schneider,* bismuth sulphide precipitates silver sulphide from a 

nitrate solution. A. Gibb and R. C. Philip.6 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.

" Thermochemisclie Untersuchungen, vol. 3, p. 455, 1883.

'' See W. Skey, Trans. New Zealand Inst., vol. 3, p. 225, 1870.

c Econ. fleol., vol. 2, p. 16, 1007.

'' Tour, prnkt. Chemie, 2d ser., vol. 41, p. 414, 1890.

« Trans. Am. Inst. Min. Eng., vol. 36, p. 667, 1906.

14399 Bull. 330 08 36
562 THE DATA OF GEOCHEMISTRY.

The selenide of silver, naumannite, Ag.Se, 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. Brainier" also obtained it by the same 

method. R. D. Hall and V. Lenher *' prepared the compound by reducing silver tellurite, and they also found that a telluride was precipitated by the action of tellurium upon silver solutions. "~""

Eucairite, CuAgSe; stromeyerite, CuAgS; sternbergite, AgFe2S3 ; 

and frieseite, AgoFer,Ss , 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:

Smitbite_______AgAsS2 ___________.Monoclinic.

Miargyrite^______AgSbS2 ___________Monoclinic.

Matilclite________.AgBiS,_________________(?)

Proustite______Ag:!AsSo________..____Rbombobedral. 

Xantbocouite- -__.Ag3AsSa________ ..___Monocliuic. 

Pyrargyrite-_____Ag3SbS3 ______________Rbombobedral. 

Pyrostilpnite-____Ag:)SbS..-_________.__Monoclinic.

Tapalpite c______.AgsBiTe;! Massive. 

Stephanite._-_____AgB SbS4 -_____________ Ortborbombic.

Pearceite________.AgaAsS,,-____-_____--Monoclinic.

Polybasite._____-_.Ag,,SbSu ,-___._________Ortborbombic. 

Polyargyrite_____.Ag,4 Sb,Sjr,__________-.Isometric.

Scbapbacbite-i____Ag2PbBLSG ___________.Ortborbombic. 

Brougniardite.--__Ag2PbSb2 SB - _________Isometric. 

Andorlte.._____-_AgPbSb3 Sc --__---'___- --Ortborbombic. 

Schirmerite.______ (Ag2 ,Pb) 3Bi4 S8 -_-_-_______Massive.

Diaphorite .____(Ag2 ,Pb) 6Sb4 S11 ______l__.0rtborbombic. 

Freieslebeuite_____ (Ag;,,rb) 5 Sb4 S] j_______-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, Cu8 Sb2 S7 , 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, AggSnSo, and argyrodite, Ag8GeS0 , 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 a claims to have obtained them by heating mixed chlorides

« Jour. Chem. Soc., vol. 05, p. 388, 1889.

"Jour. Am. Clieni. Soc., vol. 24, p. 919, 1902.

c Contains some sulphur partly replacing tellurium.

"Cpmpt. Rend., vol. 32, p. 825, 1851.
METALLIC ORES. 563

of silver and antimony, or silver and arsenic, in a current of hydrogen 

sulphide. Details are not given. H. de Senarmont/1 by heating a 

salt of silver to temperatures ranging from 250° to 350° with a solution of an alkaline sulpharsenitc 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 B obtained the amorphous compound Ag3 SbS3 , equivalent in composition to pyrargyrite. C. 

Doelter c prepared miargyrite, pyrargyrite, and stephanite by a modification of Senarmont's method. Silver chloride, mixed with a sodium 

carbonate solution of potassium sulphantimonate in varying proportions, was heated with hydrogen sulphide in sealed tubes to 80°-1-50°. 

Pyrargyrite was most easily formed; miargyrite appeared only once. 

Doelter d also heated silver chloride with antimony trichloride, sulphide, or oxide in hydrogen sulphide, and obtained similar results, 

H. Sommerlad ° prepared pyrargyrite, miargyrite, and stephanite by 

heating antimony sulphide and silver chloride together. With arsenic 

t risulphide, proustite was "formed. The same species, and also polyargyrite, were produced when the component sulphides were fused 

together in a stream of hydrogen sulphide. According to R. Schneider/ potassium bismuth sulphide, KBiS2 , added to a solution of silver 

nitrate, precipitates the compound AgBiS,. This, crystallized by 

fusion, becomes, matildite. Matildite was also made by Roessler^ 

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 

 - . 

"Ann. chim. phys., 3d sei-., vol. 32, pp. 171-173, 1851.

"Compt. Kencl., vol. 124, p. 1518, 1897.

" Allgem. chem. Mineralogie, p. 152.

 ' Zeitschr. Ki-yst. Min., vol. 11, p. '29, 1886.

e Zeitschr. anorg. Chemie, vol. .15, p. 173, 1897 ; vol. 18, p.'420, 1898.

' .Tour, prakt. Cliemie, 26 ser., vol. 41, p. 414, 1890.

"Zeitschr. anOrg. Chemie, vol. 9, p. 31, 1895.
564 THE DATA OF GEOCHEMISTBY.

natural phenomena are concerned; but the syntheses give hints which 

may aid in their future discovery. It is also possible that arsenical 

or antimonial solutions may react upon silver compounds, such as - 

argentite or the chlorides, and so form sulphosalts of different kinds. - 

The supposable reactions are many, and it is not easy to determine 

which ones have operated in any particular case.

The 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 iodvrite being hexagonal." */ O C?

All of 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 b 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/-' 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. A

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,

0 See G. T. Prior and L. J. Spencer, Mineralog. Mag., vol. 13, p. 174, 1902, for a general 

paper on the cerargyrite group. II. B. Kosmann (Leopoldina, vol. 30, pp. 193, 203, 1894) 

has discussed the formation of these ores from a thermochemical point, of view. A mineral having the formula 20NaCl + AgCl has been called huantajuyite.

"Coinpt. Rend., vol. 42, p. 374, 1856.

c I-I. Debray also crystallized the chloride, bromide, and iodide of silver from aqueous 

solutions in mercuric nitrate. Compt. Rend., vol. 70, p. 995, 1870. This process can 

hardly be a reproduction of natural conditions.
METALLIC ORES. 565

from Grant County, New Mexico, have been described by W. S. 

Yeates." According to W. Lindgren,1 a vein of metallic copper at 

Clifton, Arizona, appears to have been formed from chalcocite. 

Examples of this general character might be multiplied indqiinitely.

T. Carnelley c 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.** 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^ 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 ° 

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. Cop-

" Am. Tour. Sci., 3d ser., vol. 38, p. 405, 1889.

" Prof. Paper U. S. Geol. Survey. No. 43, p. 101, 1905.

S .Tour. Chem. Soc., vol. 30, p. 1, 187G. See also 11. Meldrum, Chem. News, vol. 78, 

p. 209, 1898.

a See H. Credner, Neues Jahrb., 1869, p. 1. R. Pumpelly, Am. Jour. Scl., 3d ser., vol. 

2, p. 348, 1871; Geol. Survey Michigan, vol. .1, pt. 2, 1873 ; and Proc. Am. Acad., vol. 13, 

p. 253, 1878. M. E. Wadsworth, Bull. Mus. Comp. Zool., vol. 7, p. 1, 1880. R. D. Irving, 

Mon. U. S. GeoU Survey, vol. 5, chapter 10, 1883. A. C. Lane, Rept. State Bd. Geol. Survey Michigan, 1903, p. 239.

0 Bcon. Geol., vol. 1, p. 648, 1906.
566 THE DATA OF GEOCHEMISTRY.

per itself reacts with cupric sulphate solutions, reducing them to 

cuprous form. When such a solution of cuprous sulphate is produced 

at a high temperature, it deposits crystallized metallic copper upon 

cooling.* In this way a hot ascending solution of cupric sulphate may 

dissolve copper and redeposit it at a higher, cooler level. H. C. Riddle,6 

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 c has. 

shown that superheated steam will reduce cuprous sulphide, chalcocite, to the metallic state, according to the reaction 

Cu2S+2H2O=2Cu+SO2+2H2 .

Some experiments conducted in the physical laboratory of the 

United States Geological Surve}^ d 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 G showed that copper solutions -were thus reduced at 

temperatures between 150° and 250°. R. Beck f mentions native copper filling the marrow cavities of fossil bones' in the Peruvian sandstones of Corocoro, Bolivia. The films of copper often found in 

shales, as, for example, near Enid,. Oklahoma," were doubtless precipitated by substances of organic origin.'1

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 i identified cuprite, malachite, azurite, and occasional crystals of metallic copper. 

In the last case the oxidation had been followed by a reduction. 

Other similar examples are known.

n Stokes, loc. cit. See afso earlier investigations cited by Stokes.

''Jour. Geol., vol. 9, p. 430, 1901; and Am. Chem. Jour., vol. 26, p. 377, 1901. G. 

Fernekes (Econ. Geoh, vol. 2, p. 581, 1907) has also described the precipitation of copper 

from neutral chloride solutions by Fed;..

° Compt. Rend., vol. 142, p. 1465,' 1906.

"Preliminary notice by F. E.. Wright, Science, vol. 25, p. 389, 1907.

« Ann. chim. phys., 3d ser., vol. 32, p. 140, 1851.

f Ore Deposits, Weed's translation, p. 499.

' See E. Haworth and J. Bennett, Bull. Geol. Soc. America, vol. 12, p. 2, 1900.

ft The association of copper ores, other than native copper, with organic remains is by 

no means rare. For example, E. J. Schmitz (Trans. Am. lust. Min. Erig., vol. 26, p. 101, 

1896) mentions impregnations of copper in fossil wood in the Perminn of Texas. Percy 

(Metallurgy, vol. 1, p. 211, 1875) 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, p. 43, 1903.
METALLIC OEES. 567

Among the less important ores of copper there are three arsenides, 

an antimonide, some selenides, and a telluri.de. The arsenides are 

domeykite, Cu3As; algodonite, Cu cAs; and Avhitneyite, Cu9As. 

Mohawkite is a domeykite containing several per cent of cobalt and 

nickel. Domeykite was produced artificially by G. A. Koenig," who 

passed the vapor of atsenic over red-hot copper. Horsfordite is the 

antimonide, CuG Sb. Two selenides are known, namely, berzelianite, 

Cu2Se, and umangite, Cu;!Se2 . Crookesite is a selenide of copper, 

silver, and thallium, and rickardite is the telluride, Cu4Te,. In the 

electrolytic refining of copper at Baltimore considerable quantities 

of tellurium accumulate in the slimes. It Avas 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:

Cbalcocite_____________________ .Cu-S.

Covellite_______-_______________________CuS.

Chalcopyrite____________-_____-_-_-CuFeS,..

Clialinersite b ___________________________CuFe-Sa. 

Cubanite____________________________CuFe.S.,.

Bornite"_____________________________CuB FeS4.

v To this list the rare cobalt copper sulphide, carrollite, CuCo.S.,, 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 (l found it, 

together with bornite, thus formed, probably by sublimation, at Butte, 

Montana. On another product from the same locality, W. P. Headden G discovered cubanite. Chalcopyrite was first prepared by J. 

r Fournet/ who simply fused pyrite and copper sulphide together. 

F. de Marigny (J obtained bornite by fusing pyrite with copper turnings and sulphur, a process essentially identical with Fournet'sj the 

difference in product probably depending upon the proportions of 

the materials used.

^ J. Durocher,7' by the action of hydrogen sulphide upon the vapor 

of copper chloride, obtained copper sulphide in hexagonal tables. 

H. de Senarmont i heated a solution containing ferrous and cuprous

a Am. .Tour. Sci., 4th ser., vol. 10, p. 430, 1900.

6 See E. Hussak, Centralbl. Min. Geol. Pal., 190G, p. 332.' K. Sebneider (.Tour, prakt.. 

Chemie, 2d ser., vol. 52, p.- 555, 1895) gives the formula here assigned to chalmersite to 

cubanite. .

c Formula as established by B. J. Harrington, Am. Jour. Sci., 4th ser., vol. 16, p. 151, 

1903. The older, commonly accepted formula is Cu;iPeS:!.

" Am. Geologist, vol. 28, p. 244, 1901.

" Proc. Colorado Sci. Soc., vol. 8, p. 39, 1905.

f Ann. mines. 3d ser., vol. 4, p. 3, .1.833.

» Compt. Rend., vol. 58, p. 967, 18G4. 

t " Idem, vol. 32, p. 825, 1851.

* Ann. chim. phys., 3d ser., vol. 32, p. 166, 1851.
568 THE DATA OF GEOCHEMISTRY.

chlorides, sodium persulphi.de, and a large excess of sodium bicarbonate to 250°, and so produced an amorphous precipitate having 

the composition of chalcopyrite. According to C. Doelter,0 malachite, 

heated with hydrogen sulphide solution to S0°-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-)-Fe2 Oa 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 & 

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 c 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 ll at Bourbon-l'Archambault. E. Chuard ° 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/ 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; 9 and in dioritic rocks at Ookiep, 

Namaqualand, by A. Schenck.'1 In a pegmatite near Princeton, 

British Columbia, J. F. Kemp i 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

" Zeitschr. Kryst. Min., vol. 11, pp. 34-36, 1S86. 

" Idem, vol. 17, p. 497, 1890.

' c Ann. mines, 7th ser., vol. 8, p. 439, 1875; Compt. Rend., vol. 80, p. 461, 1875; 

Etudes synth6tiques de geologic expe"rimentale, .pp. 72-86. 

" Compt. Rend., vol. 80, p. 1297, 1875. 

" Idem, vol. 113, p. 194, 1891. 

t Bull. Soc. ge"ol. Belg., vol. 3, M6m., p. 179, 1889. 

o Zeitschr. prakt. Geol., 1901, p. 321.

* Zeitschr. Deutsch. geol. Gesell., vol. 53, Verhandl., p. 64, 1901. See also W. H. Weed, 

Eng. and Min. .Tour., vol. 79, p. 272, 1905.

* Trans. Am. Inst. Min. Eng., vol. 31, p. 182, 1901. See also J. Catherinet, Eng. and 

Min. Jour., vol. 79, p. 125", 1905.
METALLIC ORES. 569

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. Jeremeef," 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,6 who treated cupriferous pyrite 

with dilute solutions of copper sulphate find sulphur dioxide and 

obtained films of cuprous sulphide. The sulphides of arsenic, lead, 

and zinc precipitated copper sulphide from sulphate in the same way. 

Chalcocite is thus formed both from pyrite and zinc blende, according to W. Lindgren,6 at Clifton and Morenci, in Arizona. Chalcocite 

itself alters into chalcopyrite, bornite, and covellite,'' the last species 

being almost invariably of secondary origin. Covellite heated with 

a solution of sodium bicarbonate was found by H. N. Stokes G 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.'' 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 occurs 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 h_________________________________Cu:.SbS3 .

Bournonite _____ _____ ____ ____.CuPbSbS3 . Wittichenite____.___.______- -______-___-_.Cu3BiS3 .

Aikenite________-______ __________CuPbBiS3.

" Zeitschr. Kryst. Min., vol. 31, p. 508, 1899.

» Bull. Geol. Soc. America, vol.. 14, p. 269, 1903. See also T. T. Reed, Bull. Am. Inst. 

Mln. Eng., March, 1906, p. 261, and E. C. Sullivan, idem, January, 1907, p. 143.

» Prof. Paper U. S. Geol. Survey No. 43, pp. 182-186, 1905.

'' See Dana's System of Mineralogy, 6th ed., p. 56.

« Econ. Geol., vol. 2, p. 14, 1907.

f Bull. U. S. Geol. Survey No. 186, p. 44, 1900.

' At Copper Mountain, British Columbia, according to Kernp (Econ. Geol., vol. 1, p. 11, 

1905), the original ore was bornite; and from that mineral covellite with limonlte, then 

chalcocite, and finally chalcocite with chalcopyrite were successively derived. See also 

.T. Catharinet, Eng. and Min. Jour., vol. 79, p. 125, 1905.

* Copper partly replaced by silver and iron.
570 THE DATA OF GEOCHEMISTEY.

Enargite__________________________.Gu3AsS4 .

Faniatiuite__________________________.Cu3 SbS4 . 

Tennantite______1______________________.CusAsaST . 

Tetraheclrite__________________1_______CnsSbaST . 

Klaprotholite__________'________________.Cu«Bi4 S,. 

Epigenite " _____________________________.Cu7As2 Sj-. 

Cuprobismutite______________________ __CuaBisS] 5 .

The foregoing formulae are typical, and make no allowance for the 

frequent replacements of copper by other metals, or .of bismuth, 

antimony, and arsenic by one another. For example, there are intermediate mixtures between tennantite and tetrahedrite, and bismuth, 

presumably as Cu8Bi2S7 , is sometimes present in them. There are 

also varieties of these minerals containing very notable proportions 

of silver, mercury, zinc, or lead; but all reduce to the same general 

type of formula.

R. Schneider,6 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 ° 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* when a 

proper mixture of the chlorides or oxj^compounds 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°, H. Sommerlad 6 prepared chalcostibite. Another preparation, corresponding to Cu2Sb4S7 , was similarly obtained. By fusing together their 

component elements, in proper proportion, F. Ducatte f obtained 

emplectite, aikenite, and wittichenite. . 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. Hillebrand g has identified olivenite, erinite, tyrolite, chalcophyllite, cli0 Copper partly replaced by iron.

"Pogg. Annalen; vol. 127, p. 316, 1866.

c Jour, prakt. Chemie, seiv 2, vol. 40, p. 564, 1889.

d ZeitscM-. Kvyst. Min., vol. 11, p. 38, 1886.

« Zeitschr. anorg. Chemie, vol. 18, p. 420, ISOS.

'Thesis, Univ. Paris, 1902.

o Bull. U. S. Geol. Survey No. 20, 1885, and No. 55, 1889.
METALLIC OEES. 571

noclasite, 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 tAvo oxides of copper, cuprite, Cu2O, 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," 

and also as an incrustation upon ancient objects of copper or bronze.6 

Both compounds are easily prepared synthetically. Crednerite is 

another oxidized compound, having the formula Cu3Mn4 00 . 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 oxychloricle, atacamite, 

CuoCl (OH) 3 , is more common, and in Chile it has some significance 

as an ore. c Several syntheses of it have been reported. F. Field (l

obtained atacamite by the action of calcium hypochlorite upon a solution of copper sulphate. C. Friedel c obtained it by heating a solution 

of ferric chloride with cuprous oxide to. 250°. Neither of these syntheses, however, corresponds to any probable process in nature. The 

observed development of atacamite upon ancient copper and bronze 

gives a better notion of its genesis. G. Tschermak f reports an alteration of atacamite to malachite, and has shoAvn that the change can 

be artificially reproduced when the oxychloricle is slowly digested 

with sodium bicarbonate. Pseudomorphs of chrysocolla after atacamite have been described by C. Barwald.^

The sulphates of copper, normal, basic, and double, are represented 

by a number of mineral species, but only two of them are important. 

These are the normal salt, chalcanthite, CuSO4 .5H.,O; and the basic 

brochantite, Cu4SO4 (OH) fi . 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,'1 chalcanthite is found in significant quantities as an impregnation ill partially decomposed granitic 

rocks, associated with some malachite, azurite, and chrysocolla. 

Pyrite and chalcopyrite are also 'present, the oxidation of the latter 

mineral having furnished the sulphate. Brochantite, a rarer species, 

appears to be more common than is generally supposed. W. Lindgren i has called attention to its presence in the Clifton-Morenci mines 

of Arizona, where it occurs in fibrous forms which might easily be

" See, for example, A. Arzrurii, Zeitschr. Kryst. Min., vol. 18, p. 58, 1891. 

6 In addition to cases already cited, see A. Lacroix, Bull. Soc. min., vol. 0, p. 17.3. 

c For a description of an atacamite ore body, see .1. A. W. Murdoch, Trans. Inst. Min. 

Met., vol. 9, p. 300, 1901. 

"Phil. Mag., 4th 'ser., vol..24, p. 123, 1862. 

' Compt. Rend., vol. 77, p. 211, 1873.

'.Tahrb. K.-k. geol. Reichsanstalt, vol. 23, Min. Mitth., p. 41. 

"Zeitschr. Kryst. Min., vol. 7, p. 100, 1883. 

* Zeitschr. prakt. Geol., 1002, p. 147. 

1 Prof. Paper U. S. Geol. Survey No. 43, p. 119, 1905.
572 THE DATA OF GEOCHEMISTEY.

mistaken for malachite. F. Field a prepared brochantite artificially 

by boiling a solution of copper sulphate with a very small quantity 

of caustic potash. S. Meunier b 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,(OH) 2C(X,, and azurite, Cu3 (OH) 2 (C03 ) 2 . Both 

species are formed in the upper portions of ore deposits, by the 

action of carbonated waters upon copper compounds, or by reactions 

between cupreous solutions and limestones. They also are found in 

the patina of ancient bronzes, A. de Schulten c prepared malachite 

by heating precipitated copper carbonate with a solution of ammonium carbonate on a water bath during eight days. Later ,d upon 

heating a solution of copper, carbonate in carbonated water, he obtained a precipitate of malachite. L. Michel e 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, CuH2SiO4 , is rare; chrysocolla, CuSiOs.2H2 0, is 

common. A. C. Becquerel f 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 a 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 small quantities of the precious metals can be determined by fire assay, but the volatility of 

mercury prohibits its detection by such simple means.

"Phil. Mag., 4th ser., vol. 24, p. 123, 1862.

» Compt. Rend., vol. 86, p. 686, 1878.

c Idem, vol. 110, p. 202, 1890.

" Idem, vol. 122, p. 1352, 1896.

" Bull. Soc. ruin., vol. 13, p. 139, 1890. 

. f Compt. Rend., vol. 07, p. 1081, 1868.

« Econ. Geol., vol. 1, p. 67, 1905. Complete report in Bull. U. S. Geol. Survey No. 312, 

1907.
METAULIC ORES. 578

Apart from the natural amalgams of silver and gold, Avhich have 

already been mentioned, mercury occurs in the following minerals:

Native mercury_________________,__Hg.

Cinnabar___________________________HgS. 

Metacinuabaritea____________________HgS.

Tieuiannite_--_--________________:____llgSe.

Coloradoite.___________ ____________HgTe.

Onofrite___---__ -___________________._____.Hg(S,Se).

Lehrbac.hite.--- ________- -__--_____.___.HgSe+PbSe.

Livingstoiiite___-- ________ __________.HgSb4£,.

Monti'oytlite---.- _ __ -__- _______HgO.

Calomel._____________.___.-__._______Hg,CL.

Terlingiuiite_-_--____________1________Hg.,C10.

Eglestonite-----___________________________Hg.CLO.

To these must be added kleinite, a curious sulphato-chloride of 

one of the merciirammonium bases. Ammiolite and barcenite are 

antimonates or antimonites of mercury, of uncertain composition. 

.The native iodide of mercury is said to exist, but its character is 

more than doubtful. Mercury is also found in some tetrahedrite, in 

proportions varying as high as 17 per cent.

Very few of these minerals have any economic significance. Cinnabar is almost the sole ore of mercury, although the native metal is 

sometimes found in notable quantities. In some of the California 

mines metacinnabarite, the black sulphide, was once abundant, and 

tiemannite, the selenide of mercury, was commercially worked at one 

time in the Lucky Boy claim in TJtah. & Livingstonite is a workable 

ore at Huitzuco in Mexico, and barcenite is a substance produced by 

its oxidation. 0 Montroydite, terlinguaite, eglestonite, and kleinite 

are secondary minerals, which occur in small quantities as derivatives 

of cinnabar, in the mines of Brewster County, Texas.* Calomel has 

been found at several localities, but always as a secondary species.

Mercuric sulphide, as shown in the list of mineral species, occurs 

in two forms the red, rhombohedral cinnabar and the black, iso-

« Guadalcazarite Is metacinnabarite containing a little seine.

» See G. P. Becker, MOD. TJ. S. Geol. Survey, vol. 13, p. 385, 1888. '

c E. Halse (Trans. North of England Inst. Min. and Mech. Eng., vol. 45, p. 72, 1895- 

96) has described this locality. He ascribes the formation of the ores to solfataric 

action. J. Mactear (Trans. Inst. Min. and Met, vol. 4, p. 00, 1895), II. F. Collins (idem, 

p. 120), and .1. D. Villarello (Mem. Soc. cient. Ant. Alzate, vol. 19, p. 94, 1902; vol. 20, 

p. 389, 1903; and vol. 23, p. 395, 1906) have also described the Mexican quicksilver 

deposits. Mactear regards them all as of aqueous and probably of thermal origin.

d See A. J. Moses, Am. Jour. Sci., 4th ser., vol. 16, p. 253, 1903. Kleinite was erroneously described by A. Sachs, Sitzungsb. Akad. Berlin, 1905, p. 1091. Its true composition was first indicated by Hlllebrand, Am. .Tour. Sci., 4th ser., vol. 21, p. 85, 1906, and 

later confirmed by Sachs, Centralbl. Min. Geol. Pal., 1906, p. 200. For data concerning 

the Terllngua and other deposits of Brewster County, see B. F. Hill, Am. Tour. Sci., 4th 

ser., vol. 16, p. 251, 1903 ; E. P. Spalding. Eng. and Min. .Tour., vol. 71, p. 749, 1901; 

,R. T. Hill, Idem, vol. 74, p. 305, 1902; W. B. Phillips, idem, vol. 77, p. 160, 1904; vol. 

18, p. 212, 1904; M. P. Kirk and T. W. Malcolmson, idem, vol. 77, p. 084. 3904; and 

W. P. Blake, Trans. Am. Inst. Min. Eng., vol. 25, p. 08, 1896. 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, p. 1180, 1907.
574 THE DATA OF GEOCHEMISTRY.

metric 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." 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,6 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 6' 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. Menu d found 

that the mercuric compound was insoluble in either sodium hydroxide 

or sodium sulphide, but soluble in a mixture of the two. On dilution, the mixture deposited the black sulphide; but upon the passage 

of carbon dioxide through the solution the red modification, cinnabar, 

was formed. According to S. B. Christy,6 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° Avith a solution of potassium sulphydrate, was also 

transformed into cinnabar. A similar transformation of vermilion 

into cinnabar is also reported by A. Ditte/ When an excess of .vermilion is slowly acted upon by a solution of potassium sulphide it 

gradually changes into the crystallized mineral. The reactions, as 

interpreted by Ditte, are rather complex, and involve the formation 

and decomposition of two double sulphides, K2HgSo and K2Hg5 S6 .

" A good summary of the individual methods for the preparation of vermilion is given 

in Watts' Diet. Applied Chem., vol. 2, article " Mercury."

" 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.

o Zeitschr. Kryst. Min., vol. 11, p. 33, 1886.

" .Tahresber. Chemie, 1876, p. 282.

" Am. Jour. Sci., 3d set1 ., vol. 17, p. 453, 1879.

t Compt. Rend., vol. 98, pp. 1271, 1380, 1884.
METALLIC ORES. 575

The results are also modified by variations in temperature and in the 

concentration of the solutions employed. J. A. Ippen's* observations resemble those of Christy. The black precipitated sulphide of 

mercury, heated in a sealed tube with a solution of sodium sulphide 

for tAvo months beloAv 45°, became crystallized as cinnabar. The 

same black sulphide, similarly treated Avith hydrochloric acid, failed 

to yield the red form.

L. L. de Koninck b 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 

sulphyclrates. Upon S!OAV dilution of the .mercuric solutions thus 

obtained, red crystalline cinnabar Avas precipitated. Upon rapid 

dilution, the black amorphous sulphide Avas throAvn cloAvn.

E. Weinschenk ° prepared cinnabar by a process remotely akin to

those employed by Durocher and Doelter. A solution of mercuric 

chloride and ammonium sulp.hocyanate AA7 as heated in a sealed tube 

from four to six days at a temperature betAveen 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 actiA^e reagent.

Finally, a crystalline mass resembling livingstonite Avas prepared 

by A. L. Baker,* AV!IO fused the sulphides of mercury and antimony 

together in an atmosphere of carbon dioxide.

.It Avill be noticed that several of the syntheses of cinnabar involve 

the solubility of mercuric sulphide in solutions of alkaline sulphides 

or sulphydrates. 6 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 Avas insoluble in alkaline sulphydrates; but according 

to G. F. Becker/ this statement is true only for cold solutions. Mercuric sulphide, heated Avith a solution of sodium sulphhydrate on the 

Avater bath, dissolves, doubtless forming a double salt of the formula 

HgS.nNa.,S. Salts of this type must be produced Avhenever mercuric sulphide is dissolved in an alkaline solution, and Ditte's researches have told us something of their nature. The solubility of 

the mercuric sulphide manifestly depends upon considerations of 

temperature, pressure, concentration, and the nature of the solutions

« Min. pet. Mitth., vol. 14, p. 114, 1894.

" Ann. Soc. guol. Belg., vol. IS, p. xxv, 1891.

c Zeitschi-. Kryst. Min., vol. 17, p. 49S, 1890.

 > Cited by Dana, System of Mineralogy, p. 110, from Chem. News, vol. 42, p. 196, 1880.

"According to G. A. Binder (Miu. pet. Mitth., vol. 12, p. 832, 1892), even distilled 

water, acting on cinnabar for five weeks at 90°,'will dissolve traces of the mineral.

t Am. Jour. Sci., 3d ser., vol. 33, p. 199, 1887. In detail, with full summaries of 

earlier work', in Mon. TJ. S. Geol. Survey, vol. 13, chapter 15, 1888. Also, preliminary, 

In Eighth Ann. Kept. U. S. Geol Survey, pi. 2, p. 935,'1889.
576 THE DATA OF GEOCHEMISTRY.

employed, whether neutral salts, sulphydrates, or polysulphides. 

That mercuric sulphide is precipitated again by dilution has been 

shown by various observers, and Becker a 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 

majr 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 Avas found by W. H. Melville l to have the following composition :

Composition of (/us at Phoenix wme.

CO2 !__,._. _______________________________ 0.74

CH4 _____^_.______________________________-______ 61.49

N.'____________________...._______ -i _ -___ 31.44

0,______________ _.___-.1 ..______________ 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 c has 

shown that hydrocarbons will precipitate mercuric sulphide from its 

alkaline solutions, first, probably, as metacinnabarite, which is a'fterwards slowly transformed into cinnabar. Another suggestion, due to 

A. Schrauf,*1 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,0 the chief deposits of mercurial ores are all 

in the neighborhood of igneous rocks, from which, it is highly probable, they Avere 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. 

The ores are commonly associated with pyrite or marcasite, sulphur,

a Loc. cit.

"Mon. U. S. Geol. Survey, vof. 13, p. 873/1888.

< Mineral Resources U. S. for 1892, p. 139, I". S. Geol. Survey, 1S93.

(l Jahrb. K.-k. geol. Reichsanstalt, vol. 41, pp. 383, 39G, 1892. Schrauf gives many 

citations of literature relative to mercury, and especially to the mines of Iclria.

e Mou. U. S. Geol. Survey, vol. 13, 1888, and also, briefly, in Mineral Resources U. S. 

for 1892, p. 139. In the monograph, Becker has- summed up the conditions at all 

important localities as known in 1887.
METALLIC OKES. 577

calcite, barite, gypsum, opal, quartz, and other secondary minerals, 

and show distinct evidence that they have been brought up from 

below in solution." In many cases, if not in all, the evidence of 

hydrous or sol.fatar.ic origin is very clear. A. Liversidge,** 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 0 found 0.0070 

gram o'f HgS. In Becker's opinion alkaline solutions containing 

sulphides are the natural solvents of the mercurial compounds; 

although. V. Spirek,fJ describing the deposits at Monte Amiata, Tuscany, suggests that the mercury was first dissolved as sulphate and 

precipitated later by alkaline polysulphides. For this supposition 

there seems to be little or no positive evidence. 'At Idria A. Schrauf c 

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 havebeen 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.

" In addition to Becker's monograph, see J. A. Phillips, Quart. Jour. Geol. Soc., vol. 35, 

p. 890, .1870; nnd T. Le Conte and W. B. Rising, Am. Jour. Sci., 3d ser., vol. 24, p. 23, 

1882, on Sulphur Bunk, California. Le Conte (idem, vol. 25, p. 424, 1883) has discussed 

the deposits at Steamboat Springs, Nevada. See also, on California!! quicksilver ores, 

W. Forstner. Eng. and Min. Jour., vol. 78, pp. 385, 426, 1904 ; and in Bull. No. 27, California State Mining Bureau. Wendeborn (Berg. u. hiittenm. Zeitung, vol. 63, p. 274, 

.1.904) lias described mercury deposits in Oregon; and G. F. Monckton (Trans. Inst. Min. 

Eng. .(British), vol. 27, p. 463; 1904) those of British Columbia. For a recent study of 

the mercury mines at Mount Avnla,. Servia, see Ii. Fischer, Zeitschr. prakt. Geol., vol. 14, 

p. 245, 1906. For an account of the mines at Almaden, Spain, see H. Kuss, Ann. mines, 

7th ser., vol. 13, p. 39, 1878. On Huancavelica, Peru, see A. F. Umlauff, Bol. Cuerpo 

ingen, minas Peru, No. 7, 1904. F. Katzer (Berg. u. hiittenm. Jahrbnch, vol. 55, p. 140, 

1907) has described the mercury deposits of Bosnia. A list of the principal mercury 

deposits of the world, by L. Demaret, is given in Ann. des. mines de Belgique, vol. 9, 

p.'35, 1904.

b Jour. Roy. Soc. New South Wales, vol. 11, p. 262. See also .). Park, Trans. New 

Zealand Inst., vol. 38, p. 27, 1904. Park cites another memoir by A. P. Griffiths, in 

Trans. New Zealand Inst. Min. Eng., vol. 2, p. 48.

« Mon. U. S. Geol. Survey, vol. 13, p. 344, 1888.

" Zeitschr. prakt. Geol., 1897, p. 369 ; idem, 1902, p. 297. Spirek gives references to 

othei1 literature concerning Monte Amiata. See also R. Rosenlecher, Zeitschr. prakt. 

Geol., 1894. p. 337, on this aiid other Tuscan deposits. On the mines of Vallalta-Sagron, 

see A. Rzehak, idem, 1905, p. 325.

"Jahrb. K.-k. geol. Reichsanstalt, vol. 41, p. 379, 1892. 

14399 Bull. 330 08 37
578 THE DATA OF GEOCHEMISTRY.

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 Avhen it is hexagonal. Cadmium is found almost exclusively as the sulphide, ZnS, or greenockite, which is also hexagonal.* Many massive blendes are really mixtures of sphalerite 

and wurtzite. 6 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." According to H.'de Senarmont,'- 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.*3 

J. Durocher f 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. Schiller g obtained crystals of greenockite. This 

observation has since been verified by R. Schneider.'1 H. SainteClaire Deville and H. Troost i fused zinc sulphate, calcium fiuoride, 

and barium sulphide together, and produced crystals of Avurtzite. 

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 J when zinc or cadmium oxide was heated in, the vapor of 

sulphur. In another paper fc he states that amorphous zinc sulphide, 

heated in an atmosphere of nitrogen or of sulphur dioxide, ciystallizes into wurtzite. P. Hautefeuille l 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. K. Lorenz m obtained wurtzite and

" A basic carbonate of cadmium and the crystallized .oxide, CdO, are recently discovered 

minerals.

» See J. Noelting, Zeitschr. Kryst. Min., vol. 17, p. 220, 1890.

c See W. Stahl, Berg. u. hiittenm. Zeitung, 1888, p. 207 ; H. Forstner, Zeitschr. Kryst. 

Min., vol. 5, p. 363, 1881: and II. Traune, Neues Tahrb.. Beil. Bd. 9, p. 151, 1894.

d Compt. Rend., vol. 32, p. 409, 1851. The description of the process is very vague.

0 See L. Bourgeois, Reproduction artiflcielle des rnine'raux, p. 28.

f Compt. Rend., vol. 32, p. 825, 1851.

» Liebig's Annalen, vol. 87, p. 34, 1853.

'' Pogg. Annalen, vol. 149, p. 391, 1873.

1 Compt. Rend., vol. 52, p. 920, 1861.

i Idem, vol. 62, p. 999, 1866.

' Idem, vol. 03, p. 188, I860.

' Idein, vol. 93, p. 824, 1881.

m Ber. Deutsch. chem. Gesell., vol. 24, p. 1501, 1891.
METALLIC' ORES. 579

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" heated metallic cadmium with sulphurous acid to 200° in 

a sealed tube. A mixture of amorphous and crystalline sulphide .was 

deposited. A. Ditte fe found that amorphous cadmium sulphide could 

be dissolved in ammonium sulphydrate, especially at a temperature 

of GO 0 . 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. Gr. 

Bischof^ for example, mentions a sinter, formed within historical 

times iii an old lead mine, which contained 37.57 per cent of ZnS. It 

was probably produced by the action of decaying wood upon the zincbearing mine waters. In North St. Louis, Missouri, H. A. Wheeler ll 

found massive blende embedded in lignite, Avhere it had evidently 

been formed by the reducing action of organic matter upon other 

zinc compounds. C. E. Keyes c speaks of blende crystals, one-fourth 

inch across, which had groAvn on iron nails immersed in a mine water 

during fifteen years. W. P. Jenney f 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.*' Evidently the zinc had been dissolved, 

probably by the oxidation of blende, and then thrown down again, 

either by sulphureted waters or by organic matter. Natural solutions of zinc sulphate exist in the region around Joplin, and have 

already been described in previous portions of this volume. 71

" Liebig;s Annalen, vol. 129, p. 350, 1864.

6 Compt. Kend., vol. 85, p. 402, 1877.

c Lehrb. chem. pbys. Geol., 2d ed., vol. 1, p. 559.

 ' Trans. Acad. Sci. St. Louis, vol. 7, p. 123, 1895. Other associations of sphalerite 

with coal, also in Missouri, sire mentioned by W. T. Jenney, in Trans. Am. Inst. Min. 

Eng., vol. 33, p. 460, 1903. -

0 Trans. Am. Inst. Min. Eug., vol. 31, p. 611, 1901.

't Idem, vol. 33, p. 470, 1903.

"Described by J. D. Kobertson, Am. Jour. Sci., 3d ser., vol. 40, p. 160, 1890; and by 

M. W. lies and J. D. I-Tawkins, Eng. and Min. .Tonr., vol. 49, p. 499, 1890,

' See ante, p. 147.
580 THE DATA OF GEOCHEMISTRY.

The oxidized compounds of zinc, as natural minerals, are fairly 

numerous. The following species are especially noteworthy:

Zincite___.._-_-___-_-_-_-____.ZnO. 

Gahnite"_____________________"____.ZnALCV 

Franklinite «_______________ *______ZnFe2O4 .

Chalcoplumite"________________1___-_.ZuO.2MnO2 .2H2 0. 

Sniithsonite-___________..________ZnCO3 .

Hydrozincite _________________________ _.__.ZuCO8 .2ZnO2H2 .

Willemite&____________________________!__.Zn2SiO4.

Calamine______________._________Zn2I-I 2SiOB .

Clinohedrite______________-__-___.ZuCaH,SiO5 . 

Hardystoiiite.______________ _ ________.ZnCa 2 Si2O7 .

To this list may be added the phosphates, hopeite ° and kehoeite; 

the arsenates, adamite, kottigite, and veszelyite; desqloizite, 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 glucinuin. None of these, species need further mention except goslarite, ZnSO4 .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.'' According to A. 

Daubree,e when zinc chloride and water vapor act upon lime at a red 

heat, /incite is formed. Ferrieres and Dupont f 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^ was able to effect its crystallization. A. Gorgeu '' 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 fluori.de and 

potassium nuoride was strongly heated in a current of steam.

The zinc spinels, gahnite and franklinite, have also been artificially prepared. J. J. Ebelmen ' obtained gahnite by fusing a inix-

" The formulae here given are ideal. Part of the nine is commonly, replaced by Ulan1, ganese or iron.

6 Troostite Is a. manganiferous willemite. 

c For a synthesis of hopeite, see C. Friedel and E. Sarasin, Bull. Soc. min., \o\. 2, p. 

153, 1879. ' .

"See H. Ti-aube, Neues .Tahrh., Bell. Bd. 9, p. 151, 1894'; and H. Hies, Am. Tour. Sci.. 3d 

ser., vol. 48, p. 256, 1894, on zincite as a furnace product. See also J. T. Cundell and 

A. Hutchinson, Min. Mag., vol. 9, p. 5, 1892. L. Bourgeois (Reproduction nrtificielle des 

niineraux) cites other examples, and so, too, does Kies. Bourgeois also mentions syntheses 

hy Becquerel and Regnault, hut his references are erroneous, and I can not verify them.

« Compt. Rend., vol. 39, p. 185, 1854.

f See Bourgeois, op. cit., p. 56.

a Compt. Rend., vol. 69, p. 201, 1869.

" Idem, vol. 104, p. 120, 1887.

* Ann. chim. phys., 3d ser., vol. 33, p. 34, 1851.
METALLIC ORES. . 581

ture of alumina, zinc oxide, and boron tribxide. When ferric oxide 

was used in place of alumina, franklinite Avas formed. By vaporizing aluminum chloride and zinc chloride over lime at a red heat, A. 

Daubree ft prepared gahnite; and franklinite was similarly produced 

by using the chlorides of iron and zinc. H. Sainte-Claire Deville 

and.H. Caron b obtained gahnite by vaporizing a mixture of zinc 

and aluminum fluorides in presence of boric oxide. A. Stelzner c 

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 (l report the formation of willemite and tridymite. The 

occurrence of crystallized willemite in a furnace slag has also been 

recorded by W. M. Hutchings.6 

According to A. Daubree/ willemite can be prepared by the action

of silicon tetrachloride upon zinc oxide at a red heat. This, however, Avas denied by H. Sainte-Claire Deville/ who found that willemite Avas decomposed by silicon chloride. It is formed when silicon 

fluoride acts upon zinc oxide, and also by the action of zinc fluoride 

upon heated silica. A. Gorgeu h produced willemite by tA\7 o processes. First, zinc sulphate, calcined AA7 ith an alkaline sulphate and 

silica, yields Avillemite and tridymite. Secondly, the mineral is 

formed when zinc chloride is fused with silica in presence of steam.

By heating metallic zinc Avith seltzer Avater in a sealed tube at 

100°, L. Bourgeois* obtained crystals of smithsonite. G. Bischof * 

cites a number of instances in which zinc carbonate has formed as, a 

deposit from natural Avaters.

In nature, zinc ores occur under a variety' of conditions in 

true metalliferous veins, in metamorphic rocks, and under circumstances AAdiich 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 

Avell known.

In the introduction to this chapter evidence Avas adduced shoAving 

that zinc Avas present, albeit in small amounts, in Archean rocks, 

from which it may be concentrated. It is also found in diffused

« Compt. Eend., voh 39, p. 135, 1854.

" Idem, vol. 46, p. 766, 1858.

e Neues Jabrb., 1882, pt. 1, p. 170.

d Idem, 1881, pt. 1, p. 120.

" Geol. Mag., 3d ser., vol. 7, p. 31, 1890.

' Compt. Rend., vol. 39, p. 135, 1854.

"Idem, vol. 52, p. 1304, 1861.

"Idem, vol. 104, p. 120, 1887.

' Reproduction artificielle des minCrnux, p. 144.

i Lehrb. chem. phys. Geol., 2d ed., vol. 1, p. 561.
582 THE DATA OP GEOCHEMISTRY.

traces in many sedimentary rocks. L. Dieulafait a detected zinc in 

hundreds of samples of Jurassic limestone from central France. 

J. D. Robertson b found it, with lead and copper, in the limestones 

of Missouri, and J. B. Weems c 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. Eobertson's figures are as folloAvs for six Silurian magnesian limestones and seven limestones from the " Lower " 

Carboniferous; they are stated in percentages.

Lead, zinc, amd copper in limestones.

Lead. ...................................................

Silurian.

Trace to 0. 00150

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/2

Sphalerite is commonly associated with other sulphides, and especially with galena, pyrite, marcasite, and more rarely chalcopyrite. 

The association with galena is so common 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 is possible that pyrite or marcasite 

may react upon the zinc-bearing solutions and aid in the regeneration of the sphalerite. Some experiments by H. N. Stokes,6 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,

"Compt. Rend., vol. 90, p. 1573, 1880, and vol. 96, p. 70, 1883. 

"Missouri Geol. Survey, vol. 7, pp. 479-481, 1S94.

"Cited by S. Calvin and H. F. Bain,.Iowa Geol. Survey, vol. 10, p. 5GG, 1900. 

(l See T. C. Chamberlin, Geology of Wisconsin, vol. 4, pp. 367-553, 1882, and A. Winslow, Missouri Geol. Sr.rvey. vole, 6 ;ind 7, especially vol. 7, p. 467, etc., 1894. 

« Econ. Geol., vol. 2, p. 17, 1907.

a
METALLIC ORES. 583

which could be deposited only from solutions. The calamine and 

smithsonite are sometimes pure and crystalline, sometimes quite 

impure and earthy. The so-called t; 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." Similar clays, from an ore body at Leadville, Colorado, were analyzed by W. F. Hillebrand. 6

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 weredeposited from solution, which is the essential fact for the geochemist to consider.0'

The zinc mines at Franklin and Sterling Hill, New Jersey, are of 

a different type from those of the Mississippi Valley, being indeed 

unique. Here zincite, franklinite, and willemite, ores which are rare 

minerals elsewhere, are most abundant, while blende is present only 

in insignificant quantities. The ore bodies occur in crystalline limestone, in contact with gneiss, and the limestone.is pierced by numerous granitic dikes. It seems probable, from the character of the ores 

and their mineralogical associations, that they- Avere formed by contact metamorphism. A bed of limestone containing calamine and

" See W. H. Seamon, Am. Jour. Sci., 3d ser., vol. 39, p. 38, 1890 ; and J. C. Brnnner, 

Ann. Kept. Geol. Survey, .Arkansas, vol. 5, pp. 9-34, 1892. Both authors pcive analyses, 

and other analyses hy T. M. Cliatard and H. N. Stokes can be found in Bull. U. S. Geol. 

Survey No. 228, pp. 301, 362, 1904. A similar clay from Bertha, A'irginia, with 12.1 

per cent ZnO, was described by B. H. Heyward, Chem. News, vol. 44, p. 207, 1SS1.

&Mon. IJ. S. Geol. Survey,.vol. 12, p. 603, 1886.

0 For data concerning these deposits, see J. D. AVhitney, Rept. Geol. Survey, Wisconsin, vol. 1, chapter 6, 1862 ; T. C. Chamberlin, Geology of AVisconsin, vol. 4, pp. 367 553, 

1882; W. P. Blake, Bull. Geol. Soc. America, vol. 5, p. 25, 1893; U. S. Grant, Bull. No. 9, 

AVisconsin Geol. Nat. Hist. Survey, 1903, and Bull. U. S. Geol. Survey No. 260, p. 305. 

1905 ; B. B. Ellis, idem, p. 310 ; A. G. Leonard, Iowa Geol. Survey, vol. 6, pp. 13-65, 

1897; and Am. Geologist, vol. 16, p. 288, 1905; H. F. Bain, Bull. U. S. Geol. Survey 

No. 225, p. 202, 1904 ; A. Wiuslow, Missouri Geol. Survey, vols. 6 and 7, 1894, and .Tour. 

Geol., vol. 1, p. 612, 1893 ; J. D. Robertson, Am. Geologist, vol. 15, p. 235, 1895 ; Bain, 

Aran Hisej and Adams, Twenty-second Ann. Rept. U. S. Geol. Survey, pt. 2, p. 23, 1902 ; W. P. Tenney, Tirana. Am. Inst. Min. Eng., vol. 22, pp. 171, 642, 1894 ; E. Iledburg, idem, 

vol. 31, p. 379, 1901; J. C. Branner, Ann. Rept. Geol. Survey Arkansas, vol. 5, 1892, 

and Trans. Am. Inst. Min. Eng., vol. 31, p. 572, 1901 ; G. I. Adams, idem, vol. 34, 

p.' 163, 1904 ; Bull. U. S. Geol. Survey No. 213, p. 187, 1903, and Prof. Paper U. S. 

Geol. Survey No. 24, 1904 ; W. S. T. Smith, Bull. U. S. Geol. Survey No. 213, p. 196, 

1903, and A. Keith, Bull. TJ. S. Geol. Survey No. 225, p. 208, '1904. See also W. II. 

Case, Trans. Am. Inst. Min. Eng., vol. 22, p. 511, 1894, on the zinc ores, of Bertha, A'irginia. S. F. Emmons (Trans. Am. Inst. Min. Eng., vol. 22, p. 83, 1894) briefly discusses 

the origin of zinc ores, and so too does C. R. A7 an Ilise in his Treatise on metamorphism, Mon. TJ. S. Geol. Survey, vol. 47,- pp. 1125-1158, 1904. A zinc deposit in Nevada 

is described by Bain, Bull. U. S. Geol. Survey No. 285. p. 166, 1906. Other recent publications are by E. Haworth and others, Univ. Geol. Survey Kansas, vol. S, 1904 ; E. R. 

Buckley and H. A. Buehler, Missouri Bur. Geol. and Mines, 2d ser., vol. 4, 1906; IT. F. 

Bain, Bull. U. S. Geol. Survey No. 294, 1907; T. L. Watson, Bull. Am. Trist. Min. Eng., 

March,'1906. See also Bain, Bull. No. 19, Wisconsin Geol. Nat. Hist. Survey, 1907.
584 THE DATA OF GEOCHEMISTBY.

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,a 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. 6

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."

The principal ore of lead is the normal sulphide, galena, PbS. 

Allied to this are the rare selenide, clausthalite, and altaite, the corresponding telluride/* The synthetic preparation of galena has been 

effected by various methods, both wet and dry. J. Durocher e 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/ when 

heated in the vapor of sulphur, yields, galena. F. Stolba g produced 

crystals of the sulphide by heating the amorphous compound to dull 

redness with chalk. F. de Marigny ll produced galena by fusing 

litharge with iron pyrites and starch. F. Eoessler * crystallized both 

galena and clausthalite from solution in molten lead. By distillation 

of a mixture containing lead oxide, sulphur, and ammonium chloride, 

E. Weinschenk i also prepared crystals of galena. It is furthermore 

to be noted that galena is not uncommon in furnace slags, and that 

Mayenc,on fc has reported its formation as a product of sublimation 

in a burning coal mine.

"Trans. Am. Inst. Min. Eng., vol. 24, p. 187; 1895.

6 For data regarding the Franklin region, see F. L. Nason, Ann. Rept. State Geologist, 

New Jersey, 1S90, p. 25; and J. F. .Kemp, Trans. New York Acnd. Sci., vol. 13, p. 76, 

1893. Kemp gives references to earlier literature. See also .T. E. Wolff, Bull. U. S. 

Geol. Survey No. 213, p. 214, 1903.

c A. Hamberg (Zeitschr. Kryst. Min., vol. 17, p. 253, 1890) has suggested that at 

Harstig, Sweden, the lead was reduced by arsenious oxide.

d Nagyagite is a sulphotelluride of lead, gold, and antimony. Naumannite, lehrbachite, 

and zorgite are selenides of lead with silver, mercury, or copper.

c Compt. Rend., vol. 32, p. 825, 1851. See also A. Carnot, cited by L. Bourgeois, 

Reproduction artiflcielle des mine'raux. p. 30.

f Compt. Rend., vol. 62, p. 999, 1866.

" Jahresb. Chemie, 1863, p. 242.

ft Compt. Rend., vol. 58, p. 967, 1864.

* Zeitschr. anorg. Chemie, vol. 9, p. 41, 1895. By passing selenium vapor over melted 

lead G. Little (Liebig's Annalen, vol. 112, p. 211, 1859) also produced the selenide.

i Zeitschr. Kryst. Min., vol. 17, p. 489, 1890.

7c Compt. Rend., vol. 86, p. 491, 1878,
METALLIC ORES. . 585

The foregoing syntheses of galena have small geological significance. In nature, the mineral appears to be commonly formed by 

hvdrochemical reactions, and these can be imitated in the laboratory. 

C. Doelter" allowed lead chlpric.e,'sodium bicarbonate, and a solution 

of hydrogen sulphide in water ta remain in a sealed tube at ordinary 

room temperature during five months. Crystals of galena were thus 

formed. E. Weinschenk 6 heate:! a solution of lead nitrate with, ammonium sulphydrate to 180° in a sealed tube and also obtained 

galena. H. N. Stokes G has found that pyrite or marcasite, heated 

with a solution of lead chloride to 180°, will precipitate lead sulphide. A. Daubree A observed the formation of galena, together with 

anglesite and phosgenite, by tt.e action of the ,thermal waters of 

Bourbonne-les-Bains on metallic lead. Lead sulphide is also known 

in spring deposits,6 and as a pseudomorphous replacement of other 

minerals. W. Lindgren f mentions replacements of calcite, dolomite, 

and quartz, and also of orthoclaso and rhodonite. W. H. Hobbs o has 

described secondary galena as a surface film on cerussite, 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. 7' A. Gautier * 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.^' Sartorite, dufrenoysite, guitermanite, jordanite, rathite, and lengenbachite 

are sulpharsenides. Zinkenite, plagionite, warrenite, jamesonite, semseyite, boulangerite, meneghinite, geocronite, kilbrickenite, and epiboulangerite are sulphantimonide?. Other sulphantimonides of lead 

and silver are brongniardite, diaptiorite, freieslebenite, and andorite. 

The sulphobismuthides are chiviatite, rezban}dte, galenobismutite, 

schirmerite, cosalite, schapbachite (with lead and silver), kobellite,

"Zeitschr. Kryst. Min., vol. 11, p. 41, 18J.6. A. C. Becquerel (Compt. Rend., vol. 44, 

p. 038, 1857) mentions a hydrochemical synthesis of galena, but too vaguely to warrant 

citation above.

6 Idem, vol. 17, p. 497, 1890.

c Econ. Geol., vol. 2, p. 22, 1907.

'' fitudes synthe'tiques de geologic expgrimentale, pp. 84, 85.

' See, for example, the sinter described by G. F. Becker and W. H. Melville, Mon. TJ. S. 

Geol. Survey, vol. 13, p. 344, 1888.

'Trails. Am. Inst. Min. Eng., vol. 30, p. 573, 1900.

"Am. Jour. Sci., 3d ser., vol. 50, p. 121, 18?5.

" Min. pet. Mitth., vol. 11, p. 319, 1890.

* Compt. Rend., vol. 142, p. 1465, 1906.

i Bournonite and aikinite, which contain both lead and copper, have already been mentioned under the latter metal.
586 THE DATA OF GEOCHEMISTRY.

lillianite, and beegerite. Teallite, cylindrite, and franckeite are sulphostannides, which, for present purposes, must be classified imder 

tin.

According to J. Fournet," zinkenite, PbSb2S4 , can be prepared by 

fusing galena and stibnite together in proper proportions. C. Doelter,6 by heating antimony, antimony trioxide, and lead chloride together in gaseous hydrogen sulphide, obtained jamesonite, PbSboS5 , 

mixed with stibnite and galena. By the action of molten lead chloride upon antimony trisulphidc, H. Sommerlad ° reproduced boulangerite, Pb3Sb2S0 ; zinkenite; jamesonite; warrenite (l (domingite), 

Pb3 Sb4S9 ; and plagionite, Pbr,Sb8 S17 . By fusing lead sulphide and 

arsenic trisulphide together, he obtained sartorite (scleroclase), 

PbAs2S4 , and dufrenoysite, Pb2As2Sr,. 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, Pb3O4 , 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,6 

by tallowing an alkaline solution of alumina or silica to act slowly 

upon a plate of lead, obtained crystals of massicot. The lead was 

surrounded by a coil of copper wire, and Becquerel attributed the 

synthesis to electrical action. It was more, probably a simple hydrochemical process.

Lead carbonate, cemssite, PbCOs ,. is a common mineral, produced 

by the action of carbonated waters in the upper levels of ore bodies.'' 

There are also the basic hydrocerussite, PbH (OH) 2 (CO3 ) 2 , and the 

rare dundasite, a carbonate of aluminum and lead.*' Becquerel'1

"Cited by L. Bourgeois, Reproduction artificielle des mineraux, p. 4G, from Jour, 

prakt. Chemie, vol. 2, p. 490.

"Zeitschr. Kryst. Min., vol. 11, p. 40, 1880.

c Zeitschr. anorg. Chemie, vol. 18, p. 420, 1808. Sommerlnd'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.

d According to L. J. Spencer (Min. Mag., vol. 14, p. 207, 1907), warrenite is identical 

with jamesonite.

o Compt. Rend., vol. 34, p. 29, 1852. See also, for other researches, L. Bourgeois, 

Reproduction artificielle des mineraux, p. 5G. L. Michel (Bull. Soc. min., vol.'13, p. 56, 

1890) reports syntheses of minium and plattnerite.

' A large deposit of cerussite in the Terrible mine, at Use, Colorado, has recently 

been described by R. B. Brinsmade, Eng. and Min. Jour., vol. 83, p. 844, 1907. Its 

formation is ascribed to the action of descending waters.

o See G. T. Prior, Mineralog. Mag., vol. 14, p. 167, 1906.

A Loc. cit.
METALLIC ORES. 587

obtained crystals of cerussite when, a solution of sodium and calcium 

carbonate acted gradual!}7 upon a plate of lead. E. Fremy a 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 cerussite is probably often 

formed." H. von Dechen c has reported the case of an old mine whose 

walls were covered with a thick coating of cerussite, which had been 

deposited from solution like sinter. A. Lacroix rf 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 cerussite. 0 The rare 

chloro-carbonate of lead, phosgenite, Pb,CloCO3 , Avas reproduced by 

C. Friedel and E. Sarasin f Avhen lead chloride, lead carbonate, and 

.water were heated together in a sealed tube to 180°. It was also 

prepared by A. de Schulten/ 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 ispace above.

Cotunnite, lead chloride, PbCL, is found in nature as a volcanic 

mineral, produced by sublimation. F. Stober 71 reproduced the mineral by this process, and also obtained it in minute crystals from 

simple solution in water or in aquc.ous hydrochloric acid. It was- also 

formed by A. C. Becquerel,' much earlier, by allowing a solution of 

copper sulphate and sodium chloride to act upon galena during a 

period of seven years. The sulpbate, 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, PboOCL 

and mendipite, Pb3 0,Cl2 5 have long been known. Schwartzembergite 

is like mendipite in composition, but with iodine largely replacing 

chlorine. Laurionite/ paralaurionite, penfieldite, daviesite, and fiedlerite are oxvchlorides of lead which have formed on ancient slags at «/ . o

Laurium, in Greece. Caracolite is a double salt of the composition 

PbOHCl+Na2S04. Percylite, cumengeite, and pseudoboleite are

a Compt. Kend., vol. 63, p. 714, 1866.

''The syntheses of cerussite by .1. Ribnn (Compt. Rend., vol. 93, p. 1026, 18Sl).and of 

hydrocerussite by L. Bourgeois (Bull. Soc. ruin., vol. 11, p. 221, 1888) have no relation 

to natural processes.

c Neues Jahrb., 185S, p. 216. '

<*Bull. Soc. mm., vol. 6, p. 175, 1883.

« See Blode, Neues Jahrb., 1834, p. 638.

f Bull. Soc. rain., vol. 4 p. 175, 1881.

o Idem, vol. 20, p. 194, 1897.

'' Bull. Acad. Belg., 3d ser., vol. 30, p. 345, 1895.

* Compt. Rend., vol. 34, p. 29, 1852.

 < For a synthesis of laurionite, PbOHCl, soe A. de Schulten, Bull. Soc. min., vol. 20, 

p. 180, 1897.
588 THE DATA OF GEOCHEMISTRY.

oxychlorid.es of lead and copper, and boleite is similar in composition, 

but with silver chloride as an additional component."

Lead sulphate, PbS04 , as the crystallized mineral anglesite, is a 

common oxidation derivative of galena. According to E. Jannetaz & 

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 Mace,e who added a solution of ferrous sulphate very slowly to one of lead nitrate. Essentially the same 

process was successfully followed by E. Fremy d and by E. Masing,6 

a soluble sulphate being allowed to diffuse very slowly into one of a 

lead salt in Masing's case lead nitrate. Lead sulphate, although relatively insoluble, is not absolutely so; it therefore can be crystallized, 

as the syntheses show, when it is formed with extreme slowness in 

very dilute solutions. Conditions of the sort probably attend the 

formation of anglesite in bodies of lead ore; but when carbonates are 

present in the percolating waters, cerussite is produced instead. The 

synthesis of anglesite by N. S. Manross/ who obtained it by fusing 

lead chloride with potassium sulphate, does not seem to correspond 

with any natural mode of formation.

Lanarkite is a rare, basic sulphate of lead, PbjSOg.^ 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 PbSO4 .'2PbCO3 .Pb(OH) 2 . At Granby, 

Missouri, according to W. M. Foote,'' it occurs as a pseudomorph 

after calcite and galena. In composition it suggests a double salt 

formed by the union of hydrocerussite and anglesite, in equimolecular 

proportions. i

Lead salts analogous to anglesite are the chromate, crocoite, 

PbCrO4 ; the molybdate, wulfenite, PbMoO4 ; and the tungstate, stolzite, PbW04 . The rare phcenicochroite j is a basic chromate. 

Pb8Cr2 00 ; 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 Avater.

* Pereylite, cumengeite, and boleite have been made artificially by C. Friedel, Bull. Soc. 

min., vol. 15, p. 96, 1892 ; vol. 10, p. 187, 1893, and vol. 17, p. 6, 1894. See also, in 

reference to these minerals, E. Mallard, Bull. Soc. min:, vol. 16, p. 184, 1893, and G. 

Friedel, idem, vol. 29, p. 14, 1906.

6 Bull. Soc. gCol., 3d ser., vol. 3, p. 310, 1875.

"Compt. Rend./vol. 36,'p. 825, 1853.

rf ldem, vol. 63, p. 714, 1866.

« Jahresb. Chemie, 1889, p. 4.

f Liebig's Annalen, vol. 82, p. 348, 1852. 

. <> For a synthesis of lanarkite, see A. de Schulten, Bull. Soc. min., vol. 21, p. 142, 1S98.

h Am. Jour. Sci., 3d ser., vol. 50, p. 99, 1895.

1 Palmierite, a double sulphate of lead nnd potassium, is found among the recent 

products of fumarole action at Vesuvius.

i Also called melanochroite.
METAULIO OEES. 589

When sodium timgstate is fused with lead chloride, according to 

N. S. Manross," stol/ite 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** 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 ° obtained both crocoite and phccnicochroite. Cerussite and anglesito were formed at the same time 

from impurities in the reagents. A. C. Becquerel'1 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 c found that phoenicochroite was formed 

when fragments of galena were immersed during six months in a 

solution of potassium dichromate. L. Bourgeois f boiled,precipitated 

lead chromate with dilute nitric acid. From the hot, filtered solution crystals of crocoite we.re deposited. Better results were obtained when the operation was conducted in a sealed tube at 130°. 

Lachaud and Lepierre" state that when amorphous lead chromate is 

boiled with a solution of chromic acid it crystallizes into crocoite. 

Pho3nicochroite was formed when Lead chromate and sodium chloride 

were fused together. Both chromates Avere obtained by Liideking 7t 

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, 

PbnP3 012Cl; the corresponding arsenate, mimetite, Pbr,As;iO12Cl; and 

the vanadium salt, vanadinite, P^V^O^d, occur both independently 

and in a great variety of isomcrphous mixtures. Endlichite, for 

example, is a mixture of the arsenic and vanadium compounds, and 

minerals intermediate between mimetite and pyromorphite are 

common.

 All these species have been prepared synthetically, and pyromorphite is also known as a furnace product in slag.* N. S. Manross j obtained pyromorphite by fusing !.ead chloride with tribasic sodium 

phosphate. H. Sainte-Claire Deville and H. Caron fc fused lead phosphate, lead chloride, and sodium chloride together to produce pyro-

" Liebig's Annalen, vol. 82, p. 348, 185':. H. Schultxe (idem, vol. 126, p. 51, 1863) 

prepared wulfenite in the same way.

b See .T. F. L. Hausmann, idem, vol. 81, ]>. 224, 1852.

< Idem, vol. 87, p. 120, 1853 ; vol. 89, p. 11, 1854.

 ' Compt. Rend., vol. 63, p. 1, 1866.

"Idem, vol.'87, p. 656, 1878.

'Bull. Soc. ruin., vol. 10, p. 187, 1887.

o Bull. Soc. chirn., 3d ser., vol. 6, p. 230, 1891.

h Am. Jour. Sci., 3d ser., vol. 44, p. 57.

i J. J. Noggerath, Neues Jahrb., 1847, p. 37.

'l Liebig's Annalen, vol. 82, p. 348, 1852.

fc Ann. chim. phys., 3d ser., vol. 67, p. 45:*., 1863.
590 THE DATA OF GEOCHEMISTRY.

morphite, and L. Michel a accomplished the same purpose by the 

same process, only omitting the common salt. From fusions of lead 

arsenate with lead chloride G. Lechartier J> and also Michel succeeded 

in reproducing mimetite. Vanadinite was obtained by P. Hautefeuille °' 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,fZ 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, 0 descloizite, 

cuprodescloizite, brackebuschite, and psittacinite. Bindheimite is a 

lead antimonate, formed by oxidation from sulphosalts of lead. 

Nadorite, PbClSbO.,, and ochrolite, Pb6Cl.,Sb2 O7 , 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 containing a sulphite molecule combined with the silicate. An artificial 

lead silicate from furnace slag has been described by E. S. Dana and 

S. L. Penfield t and also by H. A. Wheeler.*

The common association of lead ores with those of zinc was pointed 

out in the preceding section of this chapter. Blende and galena are 

both formed from solutions, but not always in the same manner. By 

differences in the solubility of their oxidation products the two 

metals are often separated from each other, for lead sulphate is 

slightly soluble,, while zinc sulphate is easily so. Zinc, therefore, 

disappears from the upper portions of ore bodies much more rapidly 

than lead, and, for the same reason, so does copper. The lead ores 

of Eureka, Nevada, are regarded by J. S. Curtis h as the product of 

solfataric action; those of Leadville, Colorado, according to S. F. 

Emmons,* 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.

"Bull. Soc. min., vol. 10, p. 133, 1887.

b Compt. Rend., vol. 65, p. 172, 1867.

c Idem, vol. 77, p. 896, 1873.

d Ann. chiin. phys., 3d ser., vol. 61, p. 443, 1861.

0 Phosphate, arsenate, and sulphate of lead.

f Am. .Tout-. Sci., 3d set'., vol. 30, p. 138, 1885.

a Idem, vol. 32, p. 272,.1886.

" Mon. U. S. Geol. Survey, vol. 7, chapters 7, S, 1884.

* Idem, vol. 12, p. 378, 1886. '
METALLIC OKES. 591

TIN."

Tin is one of the rarer metals, a:.id its ores are not numerous. Native tin is occasionally found, but never in more than trifling quantities and in small grains. 6 The ore of chief importance is the 

dioxide, cassiterite, SnCX, but several sulphosalts are also knoAvn. 

They are 

Stannite____________^____ ________.Cu2FeSnS4 . 

 Tealllte"____________ _..___________PbSnS*

Cylindrite_____________..___________Pb3FeSn4 Sb2S14 . 

Franckeite__-.-_-______ .- _ .Pb6FeSn3 Sb2 S14 .

There is also a A^ery rare borage of calcium and tin, nordenskioldiney* CaSnB2 00 , which is interesting because it directly connects tin 

Avith boron. 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.'-'

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 f and J. H. L. Vogt/ and L. Bourgeois h has identified the mineral in scoria from a bronze foundry. 

The first synthesis of cassiterite was performed by A. Daubree * when 

the vapor of stannic chloride vr a.s mixed Avith steam in a red-hot 

porcelain tube. Later the same chemist ' prepared the mineral by 

passing the vapor of stannic chloride over heated lime. The crystallized oxide AA^IS obtained by H. Sainte-Claire. Deville and H. Caron fc 

Avhen stannic fluoride and boric oxide were heated together to whiteness. H. Sainte-Claire Deville l also obtained it by heating the 

amorphous oxide in a S!OAV current of hydrochloric acid gas and 

again by a repetition of Daubree's first process. A. Ditte m noticed

" For a paper on the occurrence and distribution of tin, with n bibliography, see F. L. 

Hess and L. C. Graton, Bull. U. S. Geol. Survey No. 260, p. 160, 1904. A summary of 

tin localities Is also given by AV. P. Blake, in Mineral Resource's U. S. for 1883-84, pp. 

592 et set]., U. S. Geol. Survey, 1885.

b A recent discovery of native tin is noted by E.. S. SImpson in Ann.-Kept. Geol. Survey, West Australia, 1899, p. 52.

< See G. T. Prior, Mlneralog. Mag., vol. 14, p. 21, 1904, on the composition of tealllte, 

cylindrite, and franckeite. See also A. Stelzner, Neues Jahrb., 1893, pt. 2, p. 114, and A. 

Frenzel, idem, p. 125. On starinite and its alteration products from the Black Hills, see 

AY. P. Headden, Am. Tour. Sci., 3d ser., vol. 45, p. 105, 1893.

"Described by AV. C. BrOgger, Zeits:lu-. Kryst. Min., -vol. 16, p. 61, 1890.

0 See A. Stelznei; and A. Schertel, Jahrb. Berg. Hiitt. Konig. Sachsen, 1886, p. 52, on 

tin in black blende from Freiberg. It has also been found in the zinc ores of the'Slocan 

district, British Columbia. See Kept. Com.ni. on Zinc Resources, etc., of British Columbia, Mines Branch, Dept. Interior, Ottf.wa, 1906.

' Zeitschr. Kryst. Min., vol. 25, p. 46V, 1896.

a Idem, vol. 31, p. 279, 1899.

» Bull. Soc. min.,-vol. 11, p. 58, 188S.

1 Compt. Rend., vol. 20, p. 227, 184,9.

i Idem, vol. 39, p. 135, 1854.

,k Idem, vql. 46, p. 764, 1858. Details not given. -

1 Idem, vol. 53, p. 161. 1861. 

'".Idem, vol. 96, p. 701, 1883.
592 ' THE DATA OF GEOCHEMISTRY.

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,* cassiterite is perceptibly soluble in -water 

at 80°, and more so in presence of sodium fiuoride. Some recrystallization from the solution was observed. This solubility is also indicated 

by several natural occurrences of tin. S. Meunier 6 found 0.5 percent of Sn(X in an opaline deposit, resembling geyserite, from a 

thermal spring in Selangor. J. H. Collins c reports tinstone as a 

cement in certain Cornish conglomerates, as an impregnation in longburied horns of deer, as pseudomorphs after feldspar,** 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 bt) 

F. A. Genth c 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 beei 

derived from the oxidation of stannite, but this point seems to have 

received little or no consideration.

Cassiterite has been noted as a probably original constituent of 

igneous rocks/ but it more commonly occurs in veins or stringers o:-' 

quartz, under conditions which indicate a secondary deposition. As 

a rule, tin-bearing veins are found in or near persilicic rocks, such as 

pegmatites and altered granites. Sometimes the association is with 

quartz porphyry, as at Mount Bischoff, in Tasmania, 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 PotrV 

llos mine, in Durango, the ore is found along the fault planes in the

« Min. pet. Mitth., vol. 11, p. 325, 1890.

6 Compt. Rend., vol. 110, p. 1083, 1890.

c Mineralog. Mag., vol. 4, pp.' 1, 103, 1880, and vol. 5, p. 121, 1883.

d According to C. Reid and T. B. Scrivenor, Mem. Geol. Survey Eng. and Wales, Geology 

of country near Newquay, p. 39, 1906, the so-called pseudomorphs are replacements of 

orthoclase by an aggregate of cassiterite, muscovite, and quartz. On the genesis of tlie 

Cornish ores, see also J. B. Hill and D. A. MacAlister, idem, Geology of Falmouth, Truro, 

etc., p. 167.

° Proc. Am. Phil. Soc., vol. 24, p. 23, 1887. L. V. Pirsson (Am. .Tour. Sci., 3d ser., 

vol. 42, p. 407, 1891) has described crystals of hematite inclosing cassiterite, from (lie 

same locality.

f See ante, p. 291, in chapter on rock-forming minerals.
METALLIC ORES. 593

rhyolite.0 The Cacaria mine, also in Durango, is in quartz porphyry. 

In the Malay Peninsula, according to R. A. F. Penrose,6 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 zirinwaldite. 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 canying the two elements above named and also the tin. This belief is

V strengthened by the various syntheses of cassiterite, in which boricoxide and chloride or fluoride of tin have taken part. The significance of the very rare mineral nordenskioldine, Avith its tin and boron

1 together, here becomes apparent, although the species has not been 

found in any vein or deposit of the usial stanniferous type, but only

 in a dike of elaeolite syenite. Ordinarily the two elements are sepa- 

< rated, 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-bear:.ng phosphates triphylite and 

amblygonite.0 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 

1^. and Saxony, are found in the York region, Alaska; in Rockbridge

"See C. W. Kempton, Trans. Am. Inst. Min. Eng., vol. 25, p. 997, 1896, and W. R.

Ingalls, Idem, p. 147. On the Sain Alto mines, Zicatecas, see E. Halse, idem, vol. 29,

p. 502, 1900, and J. N. Nevius, Eng. and Min. Jour., vol. 75, p. 920, 1903. This locality

,,. is also rhyolitic. On the tin deposits of Guanajuatj, see A. H. Bromly, Trans. Am. Inst.

Min. Eng., vol. 30, p. 227, 1906.

"Jour. Geol., vol. 11, p. 135, 1903. On the ores of Banca and Billiton, see R. Beck, 

Zeitschr. prakt. Geol., 1898, p. 121. W. R. Rumbold (Bull. Am. Inst. Min. Eng., Septemher, 1906) has described the tin deposits of the Kinti Valley, Malay States. He mentions 

deposits in limestone.

c For discussions on the genesis of cassiterite vein!! see A. Daubr6e, Etudes synthe'tiques 

de geologic expe"rimentale, pp. 28-71; T. H. L. Vogt, Zeitschr. prakt. Geol., 1895, p. 145, 

and Trans. Am. Inst. Min. Eng., vol. 31, p. 125, 1901; and W. Lindgren, idem, vol. 30, 

p. 578, 1900. , On the Mount Bischoff mines, see W. von Fircks, Zeitschr. Deutsch. geol. 

Gesell., vol. 51, p. 431, 1899. See also F. Gautier, Actes Soc. sci. Chill, vol. 5, p. 82,

 *' 1895.

3.4399 Bull. 330 08 3§
594 THE DATA OF GEOCHEMISTRY.

County, Virginia, and near El Paso, Texas. The Alaskan field has * 

been well studied by A. J. Collier,® who describes both lodes and 

placers. The typical cassiterite is disseminated in more or less 

altered granitic dikes, essentially greisen, consisting of quartz, zinnwaldite, calcite, and fluor spar. In one case the ore is intimately associated with tourmaline, and 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,6 the ore is in quartz | 

veins in granite, the walls of the veins being converted into greisen. 

W. H. Weed c and G. B. Richardson d 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 Corn- ,| 

wall. The Temescal deposit, in southern California, as described by 

H. W. Fairbanks,6 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 y 

famous localities in Maine for lithia tourmalines and lepidolite. 

The workable cassiterite of the Carolina tin belt, according to L. C. 

Graton/ is also in pegmatite, none being found in the wall rock, y 

Here again lithia minerals are found, namely, lithiophilite and 

spodumene. The tin ores of the Black Hills, in South Dakota, seem 

to belong under this heading, and the Etta mine especially is noted * 

for its enormous crystals of spodumene and columbite. In this 

locality crystalline faces of spodumene are exposed Avhich 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." Cassiterite in pegmatite, accompanied by corundum, is reported by P. F. f 

Molengraaf h 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

« Bull. U. S. Geol. Survey No. 229, 1904 ; and also in Bull. No. 225, p. 154, 1903; Bull. V 

No. 259, p. 120, 1905; and Eng. and MinT Jour., vol. 76, p. 999, 1903. See also A. H. 

Brooks, Mineral Resources TJ. S. for 1900, p. 267, TJ. S. Geol. Survey, 1901, and Bull. No. 

213, p. 92, 1902; and E. Rickard, Eng. and Min. Jour., vol. 75, p. 30, 1903.

» Bull. U. S. Geol. Survey No. 293, p. 44, 1906. See also T. TJlke, Mineral Resources 

TJ. S. for 1893, p. 178, TJ. S. Geol. Survey, 1894. ->

"Bull. U. S. Geol. Survey No. 178, 1901, and also in Bull. No. 213, p. 170, 1902.

* Bull. U. S. Geol. Survey No. 285, p. 146, 1905.

« Am. Jour. Sci., 4th ser., vol. 4, p. 39, 1897.

'Bull. TJ. S. Geol. Survey No. 293, 1906, and also in Bull. No. 260, p. 188, 1904. 

Other papers on the Carolina belt are by J. H. Pratt, Mineral Resources U. S. for 1903, 

p. 337, TJ. S. Geol. Survey, 1904, and Pratt and D. B. Sterrett, Bull. No. 19, North 

Carolina Geol. Survey, 1904. \

« See W. P. Blake, Trans. Am. Inst. Mln. Eng., vol. 13, p. 691, 1885. On the Black 

Hills mines, see also E. W. Claypole, Am. Geologist, vol. 9, p. 228,1892, and J. D. Irving, 

Prof. Paper TJ. S. Geol. Survey No. 26, p. 95, 1904. i'

"See abstract in Zeitschr. prakt. Geol., 1900, p. 146. tf
METALLIC ORES. 595

bismuth in rocks of recent volcanic origin. According to A. W. 

Stelzner a the rock is commonly dacite or trachyte; but at Potosi, 

as described by A. F. Wendt,1 the matrix is rhyolite. Boron arid 

fluosilicates are absent. 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.

ARSENIC, ANTIMONY, AND BISMUTH.

Arsenic, antimony, and bismuth are three closely related elements. 

Arsenic, from a purely chemical point of view, is a nonmetal; for, 

despite its metallic appearance, it is an acid-forming element, and 

only in exceptional cases does it play the part of a base. Antimony 

is more commonly acid than bnsic, 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 2. 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, 

 FeAsa , and leucopyrite, Fe3As4 , and also the sulpharsenide, arsenopyrite, FeAsS. Arsenopyrite or mispickel is the most important 

ore of arsenic.

Native arsenic, native antimony, and native bismuth are all rather 

common minerals, and with them the arsenide of antimony, allemontite, SbAs,,, may be grouped. There are also natural sulphides, 

selenides and tellurides, as fo.lows:

Realgar __ _____AsS.

Orpimerit _____As2S3 .

Stibuite_____-___ _ ___ _ ._________________ Sb2S3.

Metastibnite . _____'_______ Sb2S3.

Bismutbinite______________________________Bi2 S3 .

Guanajuatite __ ..__ _ _ _ ___ Bi2Se;! . 

Tetradymite ___'_ - .... ___________Bi,1^.

Joseite c_ .. _ .Bi.Te. 

Wehrlite 0 ____ - ______ ______Bi8Te_. 

Griinliugite _"_ _...__ __ __________. Bi4TeS,. 

Kerrnesite __ .__ _-- _-__ _. Sb2 S2 0.

a Zeitschr. Deutsch. geol. Gesell., vol. 49, p. 51, 1897. See also M. Frochot, Ann. 

mines, 9th ser., vol. 19, p. 186, 1901.

"Trails. Am. Inst. Min. Eng., vol. 19, p. 90, 1890.

c Formula; approximate only. Sulphur or selenium partly replaces tellurium,
596 THE DATA OF GEOCHEMISTKY.

Several of these minerals have been produced artificially. J. 

Durocher a prepared stibnite and bismuthinite by the action of hydrogen sulphide upon the volatilized chlorides of antimony and bismuth. H. de Senarmont 6 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 c obtained orpiment and stibnite by heating solutions of arsenic or antimony with ammonium sulphocyanate to 180° in a sealed 

tube. According to A. Carnot,d 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 Mayengon c as found among the 

sublimation products of a burning coal mine/

C. Doeltei'0 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 n report both 

realgar and orpiment from a hot spring in the Yellowstone National 

Park, and G. F. Becker i found sulphides of arsenic and antimony 

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

Sb2Sa+As,S3 ________________.___________ 78. 0308

Fe2O3 __________________________________________ 3.5924

"Compt. Rend., vol. 32, p. 825, 1851.

6 Ann. chim. phys., 3d ser., vol. 32, p. 129, 1851.

c Zeitschr. Kryst. Mm., vol. 17, p. 497, 1890.

d See L. Bourgeois, Reproduction artiflcielle des minCraux, pp. 41, 42.

o Compt. Rend., vol. 86, p. 491, 1878 ; vol. 92, p. 854, 1881.

' 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, p. 1106, 1907.

" Min. pet. Mitth., vol. 11, p. 322, 1890.

n Am. Jour. Sci., 3d ser., vol. 42, p. 401, 1891. At another spring in the Park, Arnold 

Hague (idem, vol. 34, p. 171, 1887) found a deposit of scorodite, an arsenate of iron.

* Mon. U. $ Geol. Survey, vol. 13, p. 344, 1888.
METALLIC ORES. 597

The antimony sulphide was in t'le amorphous, orange-colored form, 

to which Becker gave the name of metastibnite. Crystals of ordinary 

stibnite have since been discovered by W. Lindgren a in the same 

sinter, apparently of quite recent formation. The locality, it must 

be observed, is one which yields mercury, and G. F. Becker l has reported stibnite from several quicksilver mines in California. A 

similar association of stibnite and cinnabar is found at Monte 

Amiata in Tuscany: c and at Huitzuco, Mexico, stibnite occurs with 

livingstonite, kermesite, barcenite, and some cinnabar in a matrix of 

gypsum.rf Cinnabar has also been noted in the antimony mines of 

Corsica. 0 According to Coquand/ the antimony ores at Pereta, Tuscany, are of solfataric origin. This mode of deposition, Avhich genetically connects antimony and mercury, may be ascribed to the fact 

that.both metals form easily volatile compounds. The same property

is shared by arsenic, but deposits of other than solfataric nature are 

known. At least, there are deposits in which no indication of solfataric action can now be discerned. The sulphides of arsenic and 

antimony are easily soluble in alkaline solutions, and in that way 

may be transported vto points i:ar 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 mos; t cases evident, and its alkaline solutions, 

which also dissolve silica, seem to have formed the typical occurrences, in which stibnite is intimately associated with quartz. It is 

so found in the mines of Sevier County, Arkansas \° 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,'1 the stibnite is 

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.i When either 

arsenic, antimony, or bismuth i;> found in a metalliferous vein, associated with silver, copper, or lead, it is usually combined with those 

metals in the form' of sulphosaLts.

'"Irons. Am. Inst. Min. Eng., vol. 36, p. 27, 1906.

"Op. cit., p. 889.

«B. Lotti, Zeitschr. prakt. Geol., 1901. p. 43.

<* .T. G. Aguilera, Trans. Am. Inst. Min. Eng., vol. 32, p. 307, 1902. \

« Nentlen, Ann. mines, 9th ser., vol. 12, p. 251, 1897.

'Bull. Soc. g<5ol.,'2d ser., vol. 6, p. 91, 1848-49.

" See C. E. Wait, Trans. Am. Inst. Min. Eng., vol. 8. p. 42, 1879; .T. C. Branner, Ann. 

Kept. Geol. Survey, Arkansas, 1888, vol. 1, p. 136, and G. II. Ashley, Proc. Am. Phil. 

Soc., vol. 36, p. 306, 1897. - ' 

bi-,"cZeitschr. prakt. Geol., 1900, p. 33.

';;-<«Dri* the arsenic mines of Hastings County, Ontario, see J. W. Wells, Kept. Bur. 

MlneS> Ontario,-'1902, p. 101. .T. L. Cowan (Eng. and Min. Jour., vol. 78, p. 105, 1904) 

has described-'an arsenic mine at Brinton, Virginia. ' For the antimony mines of Nova 

Scotia, see \V."'R: Askwith, Canadian Mining Review, vol. 20, p. 173, 1901.
598 THE DATA CXF GEOCHEMISTRY.

By oxidation of the sulphides, a large number of secondary minerals can be formed. First of all are the oxides, as follows:

Arsenolite °____________________As203, isometric.

Claudetite «_____________________As2O3 , monoclinic. 

Senarmontite_____________________-Sb2O3 , isometric. 

Valentinite______________________.Sb2O3 , orthorhombic.

Cervantite_______________________Sb2O4. 

Bismite, or bismuth ocber______________Bi2Os. 

Stibiconite __ _ _________!_________H2Sb2O0.

Bismuth also forms two basic carbonates, bismutite and bismutosphserite, and a rare oxychloride, daubreeite. The oxides of antimony 

form important ore bodies at Altar, Sonora, Mexico,6 and in Neocomian limestone at Mount Hamimat, province of Constantine, Algeria."

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, Fe2 Sb2 07 , are found in the cinnabar-_bearing gravels 

of Tripuhy, Brazil/* They were derived from mica schists, but their 

association with cinnabar is suggestive.

NICKEL AND COBALT.«

Among the minor constituents of igneous rocks, nickel is one of 

the commonest. Cobalt also is widely diffused, but in much smaller

" The true molecular weight, as shown by the vapor density, is more probably represented by the formula As46o. A similar doubling may be proper for the other oxides 

and sulphides of this group.

",E. T. Cox, Am. Jour. Sci., 3d ser., vol. 20, p. 421, 1880.

c Coquand, Bull. Soc..ge"ol., 2d ser., vol. 9, p. 342, 1851-52.

rf See E. Hussak and G. T. Prior, Mineralog. Mag., vol. 11, pp. 80, 176, 302, 1895.

" For a general paper upon nickel and its occurrences, see P. Argall, Proc. Colorado 

Sci. ,Soc., vol. 4, p. 395, 1893. 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, p. 25, 1857. On cobalt ores at Schweina, Thuringia, see F. Beyschlag, 

Zeitschr. prakt. Geol., 1898, p. 1. On cobalt in Mexico, G. de J. Caballero, Mem. Soc, 

cient. Ant. Alzate, vol. 18, p. 197, 1902. O. Stutzer (Zeitschr. prakt. Geol., 1906, p. 294) 

has described tourmaline-bearing cobalt veins at San Juan, Atacama, Chile. The ore is 

cobaltite.
ORES. 599

proportions.0 In 262 analyses of igneous rocks made in the laboratory of the United States Geological Survey an average of 0.0274 

per cent of nickel oxide was found. Had it been sought for in all 

cases, this figure might have been slightly reduced, but perhaps not 

materially.

Nickel and cobalt are characteristic elements in > meteoric irons, 

and also in terrestrial irons otf similar character. Indeed, some of 

the " irons " of which analyses are given in another chapter of this 

book 6 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 class the 

chief minerals are as follows:

Millerite ____ ______ NiS. 

Beyrichite ___ _.___ _ Ni3S4 .

Polydymite 0 __________ Ni4S5- 

Nicclite ________ ____

Chloanthite __ _______ __NiAss. 

Rammelsbergite __ _ _ NiAs2 .

Gersdorffite ___.______.NiAsS. 

Pentlanclite e_______________,(FeNi )S.

Jaipurite __ _ CoS. 

Linnoeite ____ _ - -CoaS4.

Smaltite ____________CoAs2. 

Safflorite _____________CoASn.

Skutterudite <*________CoAs3. 

Cobaltite___'_______.CoAsS.

Carrollite___________Co2CuS4.

With these minerals we may include the nickel telluride, melonite, 

and the antirnonide, breithauj)tite, NiSb. Ullmannite is a sulphide 

of antimony and nickel/ 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 NiCoS2 Sb2 has been named willyamite.

Arsenides and antimonides of nickel are known as accidental furnace products.*7 The crystalline sulphides of cobalt and nickel have 

also been repeatedly prepared artificially. H. de Senarmont h heated 

solutions of potassium sulphide with nickel or cobalt chloride to temperatures between 160° and 180° in a sealed tube, and obtained the

a On the wide j diffusion of cobalt anil nickel In nature, see K. Kraut, Zeitscbr. angew. 

Cheuiie, 1906, p. 1793.

b See ante, p. 269.

c The Sudbury polydymite is very neirly Ni3FeS5.

'< There is also a variety containing much nickel replacing cobalt. Blsmutosmaltite, 

Co(AsBi) 3, is a related mineral.

0 Another nickel-iron sulphide has been called gunnarite. Its formula is near Fe3Ni2S8. 

Still another, akin to pentlandite, is the incompletely described heazlewoodlte.

' A similar sulphide, with bismuth partly replacing antimony, has been named kallilite.

» See L. Bourgeois, Reproduction artiflcielle des minfiraux, p. 35, for old instances. 

Also A. Brand, Zeitschr. Kryst. Min., vol. 12, p. 234, 1887, on breithauptite.

" Ann. chiin. phys., 3d ser., vol. 32, j>. 129, 1851.
600 THE DATA OP GEOCHEMISTRY.

compounds NiS, Ni3S4 , and Co3 S4 , corresponding to the natural minerals. C. Geitner a also produced crystals of Ni3 S4 by heating metallic nickel .with .sulphurous acid or a solution of nickel sulphite under 

pressure to 200°. E. Weinschenk 6 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 ° 

also produced jaipurite by fusing cobalt sulphate with barium sulphide and common salt.

 These scanty data show that the minerals of this group may be 

produced in either the wet or the dry way, and their natural occurrences point to the same conclusion. Millerite, for instance, forms 

beautiful tufts of slender, hairlike needles in geodes lined with crystals of dolomite. . Specimens of this kind are familiar objects in cabinets of minerals. Millerite is also reported by Des Cloizeaux A 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 6 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/ H. B. von Foullon," T. L. Walker," A. P. Coleman/ 

D. H. Browne/ and others. A. E. Barlow ,fc for example, repeatedly 

speaks of the " nickel-bearing eruptive." Browne compares the 

occurrences at Sudbury with the phenomena observed in cooling a 

copper-nickel matte, in which the copper sulphides concentrate along 

the margins of the mass, and'the nickel sulphides at the center. 

This arrangement of ores, chalcopyrite near the wall rock, then pyrrhotite carrying nickel, and finally nickel sulphide, is the order ob-' 

served at Sudbury.

°Liebig's Annalen, vol. 129, p. 350, 1864.

"Zeitschr. Kryst. Min., vol. 17, p. 497, 1890.

c Compt. Rend., vol. 65, p. 75, 1867. Jaipurite is also known as syepoorlte.

d Bull. Soc. min., vol. 3, p. 170, 1880.

«Zeitschr. prakt: Geol., 1893, pp. 125, 357.

 f Bull. Geol. Soc. America, vol. 2, p. 125, 1890. Another paper by Bell, on Sudbury, 

appears in Ann. Kept. Geol. Survey Canada, 2d ser., vol. 5, F, 1890-91.

" Jahrb. K.-k. geol. Reichsanstalt, vol. 42, p. 223, 1892. The nickel ores of Schweiderich, Bohemia, are described as analogous to those of Sudbury.

"Quart. Jour. Geol. Soc., vol. 53^ p. 40, 1897.

1 Bull. Geol. Soc. America, vol. 15, p. 551, 1904. In Kept. 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. , .

i School of Mines Quart, vol. 16,,p. 297, 1895; and Econ. Geol., vol. 1, p. 487, 1906.

fc Econ. Geol., vol. 1, pp. 454, 545,. 1906.
METALLIC: ORES. 601

R. Beck,0 C. W. Dickson,b and W. Campbell and C. W. Knight,0 

on the other hand, have argued strongly in favor of a secondary 

origin of these ores a deposition- from circulating solutions.* A 

similar view is expressed by F. W. Voit ° 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 f 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, 

Avhich J. F. Kemp c thinks is an altered gabbro or norite. This 

deposit Kemp regards as originally magmatic. In the serpentines

of Malaga, Spain, according to F. Gillman,'* niccolite is found, 

altered to silicates of nickel at the sur face, 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* 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.' 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 

are classical localities for cobalt and nickel minerals. The original 

source of the Temiskaming ores has not yet been clearly determined.

0 The Nature of Ore Deposits, Weed's translation, p. 41.

6 Trans. Am. Inst. Min. Eng., vol. 34, p. 3, 1S04. See also Jour. Canadian Mln. Inst, 

vol. 9, p. 236, 1906.

0 Eng. and Mln. Jour., vol. 82, p. 909, 1906. These authors base their opinions on 

the microscopic structure of the pyrrhotite.

d Other memoirs upon Sudbury and Its ores are by J. H. Colllns, Quart. Jour. Geol. 

.Soc., vol. 44, p. 834, 1888; J. Gamier, M6m. Soc. ingto. civlls (Prance), vol. 44, p. 239; 

E. R. Bush, Eng. and Mln. Jour., vol. 57, p. 2<{5, 1904; T. L. Walker, Am. Jour. Scl., 

3d. ser., vol. 47, p. 312, 1894 ; F. W. Clarke and C'. Catlett, Bull. U. S. Geol. Survey No. 64, 

p. 20, 1890; and L. P. Silver,. Canadian Mln.. Rev., vol. 21, p. 207, 1902. :

« Jahrb. K.-k. geol. Relchsanstult, vol. 50, p. 7:17-, 1900.

f Missouri Geol. Survey, vol. 9, pt. 4, p. 82, 1896.

»Trans. Am. Inst. Mln. Eng., vol. 24, p. 620, 1894. - 

A Trans. Inst. Min. and Met. (London), vol. 4, p. 159, 1896.

<Zeitschr. prakt. Geol., 1907, p. 73. ..- '

} 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, p. 888, 1903. . .
60'2 THE DATA OF GEOCHEMISTRY.

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.0

By oxidation or carbonation the sulphides and arsenides of nickel 

and cobalt are transformed into sulphates, arsenates, carbonates, 

oxides, etc. Morenosite, NiSO4 .7H2 0; bieberite, CoSO4.TH2O; the 

arsenates, roselite, erythrite, annabergite, forbesite, and cabrerite; 

the carbonates sphserocobaltite,1 zaratite, and remingtonite; the oxide 

bunsenite; and the hydroxides asbolite, heubachite, heterogenite, 

transvaalite, etc., are among these products of alteration. Bunsenite. 

NiO, was prepared artificially by J. J. Ebelinen,6 through the action 

of lime on fused nickel borate. Ferrieres and Dupont ° 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/ 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,6 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; f at Revda in the Urals; at Frankenstein, Prussian Silesia, in serpentine; and at Mount Avala, Servia. 

with mercurial minerals. The most important deposits, however, are

0 These ores have recently been studied microscopically by W. Campbell and C. W. 

Knight (Econ. Geol., vol. 1, p.. 767, 1906), who find that smaltite was first formed, then 

niccolite, then calcite, with argentite, native silver, and native bismuth later.

"Compt. Rend., vol. 33, p. 525, 1851. 

c See L. Bourgeois, Reproduction artificielle des mine"raux, p. 51.

d As at Mine La Motte, Missouri, and in New Caledonia. On the New Caledonia 

cobalt ores, see G. M. Colvocoresses, Eng. and Min. Jour., vol. 76, p. 816, 1903, and 

A. Liversidge, Minerals of New South Wales, pp. 275 et seq.

e F. W. Clarke and J. S. Diller, Bull. U. S. Geol; Survey No. 60, p. 21, 1890. See also, with 

regard to this locality, A. R. Ledoux, Canadian Min. Rev., vol. 20, p. 84, 1901; W. L. 

Austin, Proc. Colorado Sci. Soc., vol. 5, p. 173, 1898 ; and H. B. von Foullon, .Tahrb. 

K.-k. geol. Reichsanstalt, vol. 42, p. 223, 1892. 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, p. 120, 1907.

f See H. J. Biddle, Mineral Resources U. S. for 1886, p. 170, U. S. Geol. Survey, 1887. 

The mother rock here is dunite. See also A. E. Barlow, Jour. Canadian Min. Inst, 

vol. 9, p. 303, 1906. Barlow regards these ores as formed by the leaching of the 

peridotite.
METAULIC OEES. 603

in New Caledonia,0 where asbolite also occurs. Chromite and various 

hydromagnesian minerals are generally associated Avith 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 (SiO4 ) 8 .4H,O, and . connarite is near H4N.i 2Si3O10. Another silicate from New Caledonia, called nepouite,6 has been given 

; the formula (NiMg) 3 Si 2 07 .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 P. W. Clarke, Bull. TJ. S. Geol. Survey No. 60, 

- p. 21, 1890.

B. From Kiddles. Analysis by Hood,0 Mineral Resources TJ. S. for 1882, p. 404, TJ. S. 

Geol. Survey, 1883.

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.

SiOj..... ............................................ Ai,o3... ............:.................................

NiO.. ...............................................

MgO.................... ............................

HaO at 100° .........................................

A.

44.73

f 1. 15

27.57

 10. 56

8.87

0.99

99.90

B.

40.55

| 1. 33

29. 66

21.70

1 7.00

100. 24

C.

48.25

| .55

14.60

16.40

10.95

8.82

99.57

D.

38.35

.40

.15

32.52

10. 61

6.44

11.53

100.00

E.

cn 1 c

^7

10.20

17.43

11.28

10.37

100.00

"Probably tbis sample was dried at or near 100° before analyzing.

In one respect all the ores of nickel seem to agree. Their magmatic 

associate is always a subsilicic rock, such as norite, peridotite, or 

sometimes diabase or diorite. In no case are they clearly shown to 

have originated from persilicic magmas.

CHBOlVr.IUM.

Like nickel, chromium is widely diffused in the subsilicic rocks, 

the average proportion found in 25(1 analyses of igneous rocks in the 

laboratory of. the United. States Geological Survey being 0.05 per 

cent of Cr.Og. The native metal has not been found, nor are any terrestrial sulphides of chromium known, although the mineral daubreelite, FeCr.,S4 , occurs in some meteoric irons. The one important ore

0 See A. Liversidge, Minerals of New South Wales, p. 275 ; J. Gamier, Compt. Rend., 

vol. 86, p. 684, 1878; D. Levat, M6m. Assoc. franc,, av.' sci., 1887, p. 534 ; and F. D. 

Power, Trans. Inst. Min. Met., vol. 8, p. 427, 1.900. Liversidge gives several analyses of 

garnierite and noumeite. See also J. S. Lecl:ie, Jour. Canadian Min. Inst., vol. 6, p. 

169, 1903.

6 B. Glasser, Compt. Rend., vol. 143, p. 1173, 1906. Also Ann. mines, 10th ser., vol. 4, 

p. 448,'1904.
604 THE DATA OF GEOCHEMISTRY.

of chromium is chromite, or chromic iron. There are also the lead

 ' . . . 5^' chromates, mentioned in a previous section of this chapter; the j;wo 

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." 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 FeCr.,O4 , 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: B

Analyses of chromite.

A. From Price Creek, 'North Carolina. Analysis by C. Baskervill'e.

B. From Corundum Hill, North Carolina. Baskerville.

C. From Corundum Hill.. Analysis toy T. M. Chatard, in the laboratory of the United 

States Geological Survey. i

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.

E. From Tampadel, lower Silesia. Analysis by Laszczynski. Described by H. Traube, > 

Zeitschr. Deutsch. geol. Gesell., vol. 46, p. 50, 1894.

Cr2 03 . ...............................................

A12 03 . ...........'...................................

FeO... ..............................................

MnO ................................................

CoO,NiO......... ..................................

CuO....... ..........................................

MgO.. ..............................................

CaO... ..............................................

SiO2 . ................................................

TiO2 ....... .........................................

Ps05 ....... .........................................

A.

59.50

7.15

25.02

.92

4.42

99.91

B.

57.20

7.82

. 25. 68

.09

5.22

2.80

99.41

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. si

100. 44

E.

41.23

24.58

19.04

.58

14.77

100.20

a Magnochromite is another name for a magnesian chromite.

Chromite was first produced artificially by J. J. Ebelmen,0 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, 

J. Clouet d also prepared chromite by essentially the same process, 

only with trifling differences in detail. S. Meunier ° obtained 

chromite by oxidizing an alloy of iron and chromium, and suggested

0 See S. M. Losnnitsch, Ber. Deutsch. chem. Gesell., vol. 28, p. 2631, 1895. 

6 See also table in Chapter X, on rock-forming minerals, p. 282. Two .of the analyses 

there given are repeated here.

c Ann. chim. phys., 3d ser., vol. 22, p. 2*28, 1848. 

d Idem, 4th ser., vol. 16, p. 90, 1869. 

« Compt. Rend., vol. 110, p. 424, 1890.
METALLIC OEES. 605

J 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 chromito 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.0

wp,

MOLYBDENUM AND TUNGSTEN.

Although molybdenum and tungsten are members of the7 same 

elementary group with chromium, their geologic affinities are not 

the same. Chromium, as Ave have seen, is found characteristically in 

subsilicic rocks, while molybdenum and tungsten are commonly associated with granite. Neither metal is found free in nature, nor is 

either one widely diffused.

' The principal ore of molybdenum is- the sulphide, molybdenite, 

MoS2 . The molybdate of lead, wulfenite, has already been described 

in a previous section. Calcium molybdate, powellite, is a rare mineral, and natural molybdates oi cobalt and magnesium are imperfectly known. Molybdic ocher is a common oxidation product of 

molybdenite. It is, as shown by W. T. Schaller,b a hydrous ferric 

molybdate, Fe2 (Mo04 ) 3 .7£H2 0.

Artificial molybdenite has been prepared by A. de Schulten.0 Potassium carbonate was fused with sulphur, and molybdic oxide was 

gradually added, in successive portions, to the melt. Crystals of

v molybdenite were thus formed. Powellite, also, has been made by 

L. Michel,** who heated sodiun. molybdate, calcium chloride, and 

sodium chloride together. A little sodium tungstate was added to

y the mixture, in order to reproduce more exactly the natural mineral, 

in which some tungsten is found. 

As a rule, molybdenite is a, fairly pure compound, although

4 Michel G has described a variety containing 28.37 per cent of bismuth.

" See J. H. L. Vogt, Zeitschr. prakt. Gcol., 1894, with special reference to Norwegian 

deposits. In chromite at Kraubath, Styriu, see F. Ryba, idem, 1900, p. 837 ; and in Asia 

Minor, K. E. Weiss, idem, 1901, p. 250. R. Helmhacker (Min. Industry, 1895, p. 94) 

^ describes Austrian localities. On chromitj in Maryland, see W. Glenn, Trans. Am. Inst. 

Min. Eng., vol. 25, p. 481, 1896; and on Canadian ores, the same author in Seventeenth 

Ann. Kept. U. S. Oeol. Survey, pt. 3, p. 261, 1896. 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 sfa1 ., vol. 7, p. 281; and Trans. Am. Inst. Min. 

Eng., vol. 29, p. 17, 1899. See also J! B. Pratt and J. V. Lewis, North Carolina Geol. 

Survey, vol. 1, p. 369, 1905.

6 Am. Jour. Sci., 4th ser., vol. 23, p. 297, 1907. Work done in the laboratory of the 

y; United States Geological Survey.

"Geol. FOren. Forhandl., vol. 11, p. 401, 1889. 

s ''Bull. Soc. min., vol. 17, p. 612, 1894.

"Idem, vol. 22, p. 29, 1899.
606 THE DATA OF GEOCHEMISTEY.

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,* large 

quantities of molybdenite are found in a quartz vein in granite. At 

Cooper, Maine, as described by G. 0. Smith,6 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,0 

in veins cutting limestone, and associated with pyroxene, calcite, 

quartz, mica, pyrite, etc. The mineral Avas 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; the tungstate of manganese, hiibner- 1 

ite;. calcium tungstate, scheelite; the copper salt, cuprotungstite; and 

an alteration product, tungstic ocher, W03 . Of these, wolframite, 

hubnerite, and scheelite are economically important, and all three 

have been prepared artificially.

N. S. Manross d obtained scheelite by fusing sodium tungstate with 

calcium chloride. A. Cossa c also ^prepared it by fusing the amorphous compound, CaWO4 , with common salt. H. Debray f 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 5 produced wolframite and its manganesian varieties by fusing sodium v 

tungstate with ferrous chloride, or with the mixed chlorides of iron 

and manganese. L. Michel/1 by fusing sodium tungstate and sodium 

chloride with the chlorides of calcium, manganese, iron, or lead, "*> 

obtained scheelite, hiibnerite, wolframite, and stolzite, respectively.

"Bull. Geol. Soc. America, vol. 15, p. 283,-1904.

"Bull. U. S. Geol. Survey No. 260, p. 197, 1905. f<

c Canadian Min. Rev., vol. 22, p. 113, 1903. t

d Liebig's Annalen, vol. 81, p. 243, 1852.

" Cited by L. Bourgeois, Reproduction artiflcielle des mineraux, p. 172.

fCompt. Rend., vol. 55, p. 287, 1862.

a Liebig's Annalen, vol. 120, p. 270, 1861.

ft Bull Soc. min., vol. 2, p. 142, 1879.
METALLIC OKES. 607

Wolframite is a frequent companion of tin ores, especially in 

greisen, tlie 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,0 in 

the Etta tin district of the Black Hills. Near Lead City, in the same 

region, however, Irving foun,d 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. 6 The tungsten deposits of the Dragoon Mountains, 

Arizona, are of the same character,0 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. Criirlt d and W. H. Hobbs. 6 In the 

Sierra de Cordoba, Argentina, according to G. Bodenbender/ 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 PiLATIHTJM METALS.

The metals platinum, iridium, osmium, palladium, rhodium, and 

ruthenium form a well-defined natural group of elements, which are 

found associated with one another, and in less degree with iron, 

nickel, chromium, etc. With two exceptions the platinum metals 

occur native, or in alloys, which vary much in composition, and have 

received many specific names. The two exceptions are laurite, 

ruthenium sulphide, RuS2 ; and sperrylite, platinum arsenide, PtAs.,. 

The native metals and recognized, alloys are as follows:

Native platinum.

Native iridium, and platiniridnm. 

Native palladium, isometric. 

Allopallodium, rhornbohedral. 

Iridosiniue (Nevyanskite, over 40 per cent Ir. 

{Siserskite, 30 per cent Ir, or less. 

Palladium gold.*7 

Rhodium gold.*

"Trans. Am. Inst. Min. Eng., vol. 3L, p. 683, 1901. See also ,T. D. Irving and 

S. F. Emmons, Prof. Paper U. S. Geol. Survey No. 26, p. 163, 1904;

6 See F. B. Weeks, Twenty-first Ann. Kept. U. S. Geol. Survey, pt.'G, p. 319, 1901; and 

F. D. Smith, Eng. and Min. Jour., vol. 73, p. 304, 1902.

0 See W. P. Blake, Trans. Am. Inst. Min. Eng., vol. 28, p. 543, 1898, and F. Rlckard, 

Eng. and Min. Jour., vol. 78, p. 263, 190<t .

d Trans. Am. Inst. Mm. Eng., vol. 22, p. 236, 1893.

" Twenty-second Ann. Kept. U. S. Geol. Survey, pt. 2, p. 13, 1902.

fZeltschr. prakt. Geol., 1894, p. 409. On the tungsten ores of Colorado, see W, 

Lindgren, Econ. Geol., vol. 2, p. 453, 1907.

' See section on gold, ante, pp. 554, 555. . 
608 THE DATA OF GEOCHEMISTRY.

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: a

Analyses of native platinum.

A. From Choco, Colombia. Analysis by H. Sainte-Clalre Deville and H. Debray, Ann. 

chim. phys., 3d ser., vol. 56, p. 449, 1859.

B. Prom 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., 8d ser., vol. 

21, p. 123, 1881.

D. From Nizhni Tagilsk, Urals, Deville and Debray.

B. From Nizhni Tagilsk, blackish magnetic grains. Analysis by J. von Muchin," cited, 

with other analyses, by N. von Kokscharof, Materialien zur Mineralogie Russlands, vol. 

5, p. 186, 1866.

P. Granite Creek, British Columbia. Nonmagnetic portion of sample. Analysis by 

G. C. Hoffmann, Trans. Roy. Soc. Canada, vol. 5, sec. 3, p. 17.

G. Magnetic portion of F. Analysis by Hoffmann.

H. From Condado, Minas Geraes, Brazil. Analysis by E. Hussak, 6 Zeitschr. prakt. 

Geol., 1906, p. 284.

Pt. ..................................

Ir................. ...................

Os...................................

Pd........................ ...........

Rh............ ......:...............

Au.... ...............................

Cu. ..................................

Fe. ..................................

AljOs.. ..............................

CaO .................................

MgO............ .....................

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

.42

96.08

« Commonly but erroneously quoted as Minchin. N

6 For a paper by HllSSak on platinum and palladium iu Brazil, see Sitzungsb. Akad. 

Wien, vol. 113, Abth. 1, p. 379, 1904.

In another sample of Uralian plantinum, A. Terreil 6 found 0.75 

per cent of nickel. A remarkable nugget from the river Approuague, French Guiana, gave A. Damour ° 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:

Analyses of native iridium, etc.

A. Native iridium, Nizhni Tagilsk, Urals.

B. Platiniridium, probably from Brazil. Analyses A and B by Svanberg, Berzelius's 

Jahresbericht, vol. 15, p. 205? 1834. 

C. Iridosmine from Colombia.

a See J. F. Kemp, Bull.. U. S. Geol. Survey No. 193, 1902, for a full collection ol 

analyses, both of platinum and iridosmine. Other analyses by W. «T. Martin, jr., appear 

in Sixteenth Ann. Rept. U. S. Geol. Survey, pt. 3, p. 633, 1895. See also Dana's System 

of Mineralogy, 6th' ed., pp. 26, 27. 

. 6 Compt. Rend., vol. 82, p. 1116, 1876.

".Idem, vol. 52, p. 688, 1861.
METALLIC ORES. 609

D. Iridosmine from the Urals.

E. Iridosmine from the Urals. Analyses C, D, and E by Deville and Dehray, Ann. 

chim. phys., 3d ser., vol. 56, pp. 481, 482, 1859.

Ir... ................................................

Ft..................................................

Os...................................................

Pd. :................................................

Rh.. ................................................

Ru.. ................................................

Ch.... ..............................................

Fc.. ................................................

A.

76.80

19. G4

89

1.78

99. 11

B.

27.79

55.44

.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 o:: commerce are almost entirely from 

detrital or placer deposits, but their primary geological 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 pi.ace in the dunite, or rather serpentine, of Mount Solovief in the Urals. On the Tulameen River, 

British Columbia, according to J. F. Kemp,& the mother rock is also 

diinite, 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, ani their origin is peridotic. 0

A. Daubree,d many years ago, commenting upon the constant association of platinum with olivine rocks and chromite, pointed out the 

similarity of these rocks to meteorites. Much later, J. M. Davison c 

actually discovered platinum and iridium in the meteoric iron of 

Coahuila. Still more recently, S. Meunier"/' has discussed this relationship at some length, and argued that, contrary to the usual view, 

the n-ative platinum and iron of these rocks are not magmatic, but introduced as vaporized chlorides and subsequently reduced by heated

0 See English translation from the Russian in U. S. Geol. Survey Bull. No. 193, p. 76, 

1902.

6 Bull. U. S. .Geol. Survey No. 193, 190:1. A hrlef monograph on the geological relations and distribution of platinum.

0 See D. T. Day, Nineteenth Ann. Rept. U. S. Geol. Survey, pt. 6, p. 265, 1899. Also 

Day and R. H. Richards, Bull. U. S. Geol. Survey No. 285, p. 150, 1906. In Trans. Am. 

lust. MIn. Eng., vol. 30, p. 702, 1900, Day has a memoir on platinum in North America.

d Compt. Rend., vol. 80, p. 707, 1875. 

, « Am. Jour. Sci., 4th ser., vol. 7, p. 4, 1399.

' Compt. Rend. VII Cong. geol. internal., 1897, p. 157. Other recent papers on Uralinn 

platinum are by A. Saytzeffi, Zeitschr. prakt. Geol., 1898, p. 395; C. W. Purington, Trans. 

Am. Inst. Mln. Eng., vol. 29, p. 3, 1899; and R. Spring, Zeitschr, prakt. Geol., 1905, 

 p. 49. L. Duparc (Arch. sci. phys. nat. 4th ser., vol. 15, pp. 287, 377, 1903) also 

describes the Uralian occurrences, and givos a bibliography of them.

14399 Bull. 330 08 39
610 THE DATA OF GEOCHEMISTRY.

hydrogen. This mode of introduction and deposition Meimier 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 a mentions its occurrence in certain 

Pennsylvania!! shales, and states also that the palladium gold of 

Brazil is sometimes associated with itabirite. E. Hussak b 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,c 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/ *F. Sandberger e identified platinum in limonite nodules from 

Mexico. In an altered limestone lens in Sumatra, L. Hundeshagen f 

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/ 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 h 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 * detected 

both platinum and palladium in silver bullion; and H. Vogel i reports 

its presence in the metallic ores of Boitza, Trans}4vania. Much more 

striking, however, is the presence of platinum in the sulphide ores of 

Sudbury, Canada. Here it is found as the arsenide, sperrylite, fc

°Bull. U. S. Geol. Survey No. 193, 1902. 

"Zeitschr. Kryst, Min., vol. 42, p. 399, 1906.

c Rec. Geol. Survey, New South Wales, vol. 5, p. 33, 1896-1898. See also -J. C. H. 

Mingaye, Ann. Rept. Dept. Mines, New South Wales, 1889, p. 249. 

« See Seventeenth Ann. Rept. U. S. Geol. Survey, pt. 3, p. 282, 1896. 

" Neues Jahrb., 1875, p. 625. . .

'.Trans. Inst. Min. Met, vol. 13, p. 550, 1903-4. . 

"Econ. Geol., vol. 1, p. 749, 1906. 

11 Compt. Rend., vol. 29, p. 814, 1849.

* Liebig's Annalen, vol. 180, p. 240, 1875.

i Oesterr. Zeitschr. Berg. u. Hut.tenw., vol. 39, p. 32.

* See H. L. Wells, Am. .Tour. Sci., 3d ser., vol. 37, p. 67, 1889. Sperrylite has since 

been found by W. E. Hidden (idem, 4th seu., vol. 6, p. 381, 1898), find by Hidden .andJ. H. Pratt (idem, vol. 6, p. 467, 1898), at two localities in North Carolina, associated 

with rhodolite garnet. For details concerning Sudbury, see the section on nickel and 

cobalt, ante, p. 600.
METALLI3 ORES. 611

associated with nickeliferous pyrrhotite and chalcopyrite, but most 

intimately with the latter. F. W. Clarke and C. Catlett,0 however, 

showed its presence in massive polydymite. At the Eambler mine, 

in Wyoming, both platinum and palladium are found in covellite, 

in ores derived from diorite.^ Here, also, sperrylite has been identified. 6' 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 <l in the pegmatite 

of Copper Mountain, British Columbia. One small crystal was embedded in biotite. Platinum is also present, according to C. W. 

Dickson,c in chalcopyrite from the Key West mine, Bunkerville, 

Nevada; but sperrylite could not be detected. J, H. L. Vogt f found 

platinum to be present in the nickeliferous. pyrrhotites of Norway, 

and R. W. Brock ° 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.7'

VANADIUM AN3) URANIUM.

Although vanadium and uranium are chemically unlike, they occur 

together in one of their important ores, and are therefore considered, 

togetherjn 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.

Vanadium is reckoned among the ra:?er 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.* W. F. Hillebrand/ in a special investigation, 

examined 57 igneous rocks, and found vanadium, in most cases, in 

weighable proportions. The smallest traces were in persilicic rocks,

« Bull. U. S. Geol. Survey No. 64, p. 20, 1890.

» See W. C. Knight, Eng. and Min. Jour., vol. 72, p. 845, 1901; vol. 73, p. 696, 1902; 

J. F. Kemp, Cont. Geol. Dept. Columbia Univ., vol. 11, No. 93, 1903; S. F. Bmmons, 

Bull. U. S. Geol. Survey No. 213, p. 94, 1903; and T. T. Read, Bug. and Mln. Jour., 

vol. 79, p. 985, 1905.

c H. L. Wells and S. L. Penfield, Am. Jour. Sci., 4th set-., vol. 13, p. 95, 1902.

<*Eng. and Min. Jour., vol. 79, p. 127, 1905.

0 Jour. Canadian Min. Inst, vol. 8, p. 192, 1905. Memoir on the distribution of the 

platinum metals in other sources than placers.

t Zeitschr. prakt. Geol., 1902, p. 258.

a Eng. and Min. Jour., vol. 77, p. 280, 1904. 

h According to W. Baragwanath (Bull. No. 20, Geol. Survey Victoria, 1906), platinum 

is found in the Thomson River copper mine in a hornblende rock rich in chalcopyrite.

* See A. A. Hayes, Proc. Am. Acad., vol. 10, p. 294, 1875. 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, Gazz. chim. itah, vol. 18, p. 

259, 1883. Scattered determinations are numerous.

i Bull. U. S. Geol. Survey No. 167, p. 49, 1903. See. also J. H. L. Vogt, Zeitschr. 

t. Geol., 1899, p. 274, on the distribution of vanadium in rocks.
612 THE DATA OF GEOCHEMISTRY.

but in subsilicic varieties the amount, reckoned as V2O3 , frequently 

ran as high as 0.03 to 0.05 per cent. In the ferromagnesian minerals, 

separated from some of the rocks, the proportion of vanadium was 

even higher, in one biotite, for example, reaching 0.127 per cent of 

V2 03 . 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 a found vanadium in .French bauxite, in 

cryolite, and in rutile. P. Beauvallet 6 detected it in a French clay. 

In bricks, made from a clay found near Sydney, Australia, according 

to E. H. Rennie,c vanadium is present to a perceptible amount. 

Other Australian clays and shales gave J. C. H. Mingaye d similar 

results. He also found vanadium in the ash of coals and in the oil- . " 

bearing shales of Scotland. E. Bechi e reports vanadium in clays, 

schists, and the ashes of plants/ and C. Baskerville g fourid it in the 

ashes of peat from North Carolina. A. Jorissen h discovered it in 

delvauxite, which is a hydrous phosphate of iron.

A still more remarkable occurrence of vanadium was noted by J. J. 

Kyle i in a lignite from San Eafael, 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 V2O5 , together with silicates and sulphates of other metals. In a similar coal, .probably 

from the same region, A. Mourlot? obtained 38.5 per cent of V2O5 

from the ash; and in another, from Yauli, Peru, Torrico y Meca fc 

discovered 38 per cent. 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 con- '^ 

stituent, 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 bis- > 

muth. Mottramite, a vanadate of copper and lead, found at Alderley 

Edge, in England, has had some significance as a workable ore. It x

"Ann. chim. phys., 3d ser., vol. 61, pp. 309, 342, 1861. See also L. Dieulafait, Compt. 

Rend., vol. 93, p. 804, 1881.

»Compt. Rend., vol. 49, p. 301, 1859.

c Proc. Roy. Soc. New South Wales, vol. 17, p. 133, 1883. He cites similar examples f 

from other authorities. I

« Rec. Geol. Survey New South Wales, vol. 7, p. 219, 1903.

« Atti Accad. Lincei, 3d ser., vol. 3, p. 403, 1879.

f See also E. Demargay, Compt. Rend., vol. 130, p. 91, 1900. 

o .Tour. Am. Chem. Soc., vol. 21, p. 706, 1899.

" Ann. Soc. ge"ol. Belg., vol. 6, p. 41, 1878-9.

* Chem. News, vol. 66, p. 211, 1892. 

i Compt. Rend., vol. 117, p, 546, 1893.

* Abstract from a Peruvian original, in Jour. Chem. Soc., vol. 70, pt. 2, p. 252, 1896. s

V,
METAULIO OKES. 613

occurs as an impregnation in Keuper sandstone.* A Mexican variety 

of descloizite, ramirite,1 has also been commercially exploited. These 

vanadates, with the exception of mottramite, occur principally in 

metalliferous veins; and A. Ditte" attributes their formation to percolating vanadiferous Avaters icting on other compounds, most commonly the compounds of lead.

A sulphovanadate of copper, sulvanite, Cu3VS4 , is found in South 

Australia.** At Miriasragra, near Cerro de Pasco, Peru, another sulphide of vanadium is found, associated with pyrite, in a carbonaceous 

substance resembling a coal but abnormally rich in sulphur.6 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 SO3 , 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. Eoscoelite appeal's to be essentially a muscovite, in which 

vanadium has partly replaced aluminum/ It contains about 24 

per cent of V2 03 . In a gree:.i sandstone from Placerville, Colorado, 

W. F. Hillebrand a found 3.50 per cent of V.,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.

The metal uranium is much less abundantly diffused than vana- 

' dium. It is found in a number of rare minerals phosphates, arsenates, sulphates, carbonates, and silicates, which are all of secondary 

origin. Autunite, a phosphite 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 carnptite. Uraninite is found crystallized in pegmatites, 

and also massive in metalliferous veins, as at Joachimsthal,71

0 See H. E. Roscoe, Proc. Roy. Son., vol. 25, p. Ill, 1876.

6 See G. de J. Caballero, Mem. Soc. cient. Ant. Alzlite, vol. 20, p. 87, 1903.

" Compt. Rend., vol. 138, p. 1303, 1904.

d See G. A. Goyder, Jour. Chem. Sue., vol. 77, p. 1094, 1900.

"See F. Hewett, Eng. and Min. Jjur., vol. 82, p. 385, 1906; and J. J. Bravo, Inform, 

y Mem. Bol. Soc. Ingen. minas, Lima, 1906, vol. 8, 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, p. 141, 1907. 

. f Bull. U. S. Geol. Survey No. 167 p. 73, 1900.

" Bull. U. S. Geol. Survey No. 262, p. 18, 1905.

h On the Joachimsthal ores, see .Linda, Oesterr. Zeitschr. Berg. u. Hiittenw., vol. 50, p. 

283 ; also J. St6p and F. Becke, Zeitschr. prakt. Geol., 1905, p. 148. R. Pearce (Proc. 

Colorado Sci. Soc., vol. 5, p. 156, :.S95) has described the occurrence of uraninite in a 

mine near Central City, Colorado. On uranium ores in German East Africa, see W. 

Marckwald, Centralbl. Min. Geol. P.xl., 1906, p. 761.
614 THE DATA OF GEOCHEMISTRY.

in Bohemia, and Johanngeorgenstadt, 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,0 will serve to illustrate

the variations:

Analyses of uran/inite.

A. Hale's quarry, Glastonbury, Connecticut.

B. Near Central City or Blackhawk, 

Colorado.

C. Johanngeorgenstadt, Saxony. 

D. Nrvenite, Llano County, Texas. 

E. Broggerite, Annerod, Norway. 

F. Cleveite, Arendal, Norway.

U0t.. ....................................

UO2 ......................................

Th02 . ..:.................................

Ce02 . . ....................................

Zr02 ............................... . ....

(La, Di) 2 03 . ..............................

(Y,Er)iO................................

A12 03 .....................................

Fe2 03 ............................ . . ....

FeO......................... .

PbO. .....................................

ZnO......................... . . . ....

CuO. ............ . . . ....

MnO... ........................... ......

CaO........................... .

MgO......... .............................

B12O3 .. ...................................

V2 0i, MoO3 ,WO3 .........................

SO............................. . . ...

PiOj. .....................................

He........................................

H2O... .............................. ....

SiO2 . ................................ ....

CuFeS2 .......................... . . ....

FeSt..i. ........................... . ....

Insoluble .................... .

A.

26.48

57.43

9.79

.25

.13

.20

.40

3.20

.08

.61

.16

.70

99.49

B.

25.26

58.51

.22

7.59

.32

.70

.44

.10

.84

.22

40

.02

1.96

2.79

.24

99.82

C.

22.33

59.30

none

.20

.21

6.39

.17

.09

1.00

.17

.75

.75

31

19

.06

trace

3.17

.50

97.93

D.

20.89

44.17

6.69

.34

.34

2.36

9.46

.14

10.08

.32

.08

1.48

.46

1.47

98.28

E.

30.63

48.13

6.00

.18

.06

.27

1.11

.25

9.04

.37

.02

.17

.74

.22

4.42

99.61

F.

41.71

24.18

3.66

9.76

.03

10. 54

1.06

.10

93

undet.

1.23

.90

1.10

94.50

From these analyses no single definite formula can be deduced, 

The uranium, it is clearly seen, exercises a double function, acid and 

basic, the latter being represented by the radicle uranyl, U02 - With 

this base other bases are variably present thoria, zirconia, the rare 

earths, and oxide of lead, sometimes one and sometimes another predominating. There are also impurities of several kinds which can 

riot 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 UOS marking stages in the process of transformation 

of uraninite into gummite, a well-known alteration product of pitchblende. In gummite, which is a hydrous oxide of uranium & plus 

other bases, with from 61 to 75 per cent of U03 , the final transformation of uraninite is seen.

" See Bull. U. S. Geol. Survey No. 78, p. 43, 1891, and No. 90, p. 23, 1892, for details; 

also Bull. No. 220, pp. 111-114, 1903. 22 analyses in all are given.

6 For analyses of gummite, see H. von Foullon, Neues Jahrb., 1885, pt. 1, Ref., p. 21, 

and F. A. Genth, Am. Chern. .Tour., vol. 1, p, 89, 1879.
METAIUC OEES. 615

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.ft 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,** 

the latter by J. M. Boutwell. 0 An outlying region for carnotite in 

Rio Blanco County, Colorado, lias recently been described by H. S. 

Gale."

The following analyses of carnotite, by Hillebrand, will show its 

general character: '

Analyses of carnotite.

A. Copper Prince claim, Roc Creek, Mcntrose County. Colorado. 

B. Yellow Boy claim, La Sal Creek, Montrose County.

UO3 . ...............................................................................

V2O3 ................................................................................

PsOf, ................................................................................

Al,08 ....... ........................................................................

Fe2O 3 . ..............................................................................

CaO ................................................................................

SrO ...............................................................................

BaO ...........................:................ .............................. v . ...

UgO.. .......................................... ...................................

K2 0 ...............................................................................

Na2 0 ..............................................................................

Li2 0 ................................................................................

HsO........................................... ...................................

I:rsO+.......................................... ...................................

PbO ................................................................................

CuO.... ........................................ ...................................

Mo03 . ................................................. '.. .........................

SiO2 . ........................................... ...................................

Ti02 . ...............................................................................

C02 . ................................................................................

A.

54.89

18.49

.80

.09

.21

3.34

.02

.90

.22

0.52

2.43

2.11

1O

1 F;

.18

.15

.03

.56

7.10

98. 40

B.

54.00

1.8. 05

.05

.29

1.80

2.83

.14

5.46

1 q

2.21

.07

.05

.20

(?)

10.33

99.25

" Compt. Rend., vol. 128, p. 532, 1809. 

"Bull. TJ. S. Geol. Survey No. 2G2, p. 9, 1905. 

« Bull. U. S. Geol. Survey No. 260, p. 200, 1.904. 

"Bull. U. S. Geol. Survey No. 315, p. 110, 1907.
616 THE DATA OF GEOCHEMISTRY.

With the carnotite a vanadif erous silicate also occurs, which may be 

akin to roscoelite." 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 calciovblborthite 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 6 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. Nordenskib'ld,0 the 

ash contained about 3 per cent of U3 OS , with some nickel oxide and 

rare earths. In the ash of Swedish " kolm," a bituminous coal, H. 

Liebert, working in C. Winkler's laboratory, found from 1.68 to 2.87 

per cent of U3 08 . d An anthracitic mineral from a pegmatite vein in 

the Saguenay district, Canada, yielded J. Obalski e 2.56 per cent of 

uranium, equivalent to 35.43 per cent in the ash. The significance 

of these occurrences remains to be determined.

COLTJMBITJM, TANTALUM, AND THE RARE EARTHS.

A striking feature in the recent development of chemical industries has been the utilization of rare elements Avhich previously had 

only scientific interest. The invention of incandescent gas lighting 

has created a demand for several of these substances, and that reason 

alone is enough to justify their brief consideration here.

Columbium f and tantalum are acid-forming elements, whose 

typical oxides have the formulae Cb2O5 and Ta2O5 . They enter into 

the composition of a considerable number of minerals, which are 

found principally in pegmatites. Among these, columbite, tantalite, 

samarskite, and euxenite are by far the most important. Columbite 

and tantalite are salts of iron, FeCb.,O6 and FeTa2O0 , which commonly occur more or less isomorphously commingled, often with 

manganese partly replacing the iron. Metallic tantalum has recently 

been utilized as a substitute for the carbon filament in incandescent

"According to A. H. Phillips (Proc. Am. Phil. Soc., vol. 43, p. 157, 1904), the Utah 

carnotite contains radium.

"Trans. Roy. Soc. South Australia, vol. 30, p. 188, 1906.

"Compt. Rend., vol. 116, p. 677, 1893.

"See C. Winkler, Zeitschr. Kryst. Min., vol. 37, p. 287, 1903.

8 Jour. Canadian Min. Inst, vol. 7, p. 245, 1904.

f Known in Germany as niobium. The name columbium has about forty years' priority, and refers to the original discovery of the ore in America. Niobium is etymologically 

meaningless.
METALLIC OBES. 617

electric lights, and tantalite is the chief source from which it can be 

obtained." The supply so far is mainly from Scandinavian localities.

Zirconium and thorium are tetrad metals forming oxides of the 

type K(X. They also are found in granite rocks, and zirconium 

compounds are almost ahvays present in nepheline syenites. The 

chief zirconium mineral, zircon, ZrSi04 , has already been described 

in the chapter upon rock-forming minerals. The mineral baddeleyite, found in Ceylon and Brazil, is the oxide, Zr02 - Eudialyte, catapleiite, and the zircon-pyroxenes are complex silicates containing 

zirconia. Zircon syenite and eudklyte 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 bee>n obtained.

The typical thorium mineral is also a silicate, thorite, ThSi04 . 

The ideal species, however, has not been found, for the actual specimens are always more or less altered. The chief source of thoria, 

which is used in the manufacture of mantles for incandescent gasburners, is from monazite sand, in which the thorium compounds 

exist as variable impurities. Thoiianite, a thorium-uranium oxide 

from Ceylon, is noteworthy for being richer in helium than any 

other known mineral. Like uran:.um, thorium is strongly radioactive, and so are its compounds. 6

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, 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 foun i, 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 oed in gneiss at Bastniis, 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 als,o abundant enough to be an available ore. It is

" See Weruer von Bolton, Zeitschr. angew. Chemie, 1906, p. 1537.

6 According to C. Baskerville (Jour. Am Chem. Soc., vol. 26, p. 922, 1904), the 

thorium previously described is a mixture jf three elements, thorium, berzelium, and 

carolinitim. His results, however, have been doubted, and the question is not yet finally 

settled. For an elaborate paper on the occurrence of thorium in the mineral kingdom, 

see J. Schilling, Zeitschr. angew. Chemie, 1002, p. 869.
618 THE DATA OP GEOCHEMISTEY.

not a very rare mineral, and a notable locality for it is on Little 

Friar Mountain, Amherst County, Virginia.* Allanite has also been 

found associated with iron ores, as, for example, with the magnetite 

of Moriah, near Lake Champlain.

Monazite, the phosphate of cerium, which is normally CeP04 , is, 

however, the chief source of the cerium earths at the present day. 

It is obtained for commercial purposes from detrital deposits of 

monazite sand,& 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: c

Analyses of monazite.

A. From Portland, Connecticut. B. From the sands of Brindletown, North Carolina. 

C. From Amelia Court House, Virginia.

Pj05 ...... ...............................................................

Ce2 08 . ...................................................................

(La, Di) 2 03. .............................................................

ThOj.. ....................................................................

Si02 . .....................................................................

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, Gl2FeY2Si2 010 . 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.** 

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.

0 See J. W. Mallet, Am. Jour. Sci., 3d ser., vol. 14, p. 397, 1877.

6 On the monazite sand of North Carolina, see H. B. C. Nitze, Bull. No. 9, North Carolina'Geol. Survey, 1898. Also the references on p. 293, ante. Nitze cites 37 analyses of 

monazite. On monazite sand in the tin-hearing alluvium of the Malay Peninsula, see 

Bull. Imp. Inst, vol. 4, p. 301, 1906.

c Am. Jour. Sci., 3d ser., vol. 24, p. 250, 1882. The symbol Di represents the old 

didymium, which is now known to be a mixture of neodymium, praseodymium, samarium, 

etc.

* See W. E. Hidden and J. B. Mackintosh, Am. Jour. Sci., 3d ser., vol. 38, p. 474, 1889; 

Hidden, idem, vol. 42, p. 430, 1891; Hidden and W. F. Hillebrand, idem, vol. 46, pp. 98, 

208, 1893 ; Hillebrand, idem, 4th ser., vol. 13, p. 145, 1902 ; Hidden, idem, vol. 19, p. 

425, 1905 ; Hidden and C. H. Warren, idem, vol. 22, p. 515, 1906.
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 of 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:

1. CnH2a+2 . 6. CnH2n _8.

2. CuH2n . 7. CnH2ll-10 .

3. CnH2a-2 . 8. CnH2n -12 .

4. CuH2n-4. ' - .'

5. CnH2n -6 . 18. CnH2n -32.

Members of the first eight series have been discovered in petroleum.

These expressions, however, have only a preliminary value, although they are often used in the classification of petroleums. Each 

one represents a group of series homologous, isomeric, or polymeric, 

as the case may be and for precise work these must be taken separately. The first formula, for example, represents what are known 

as the paraffin hydrocarbons, which begin with marsh gas or methane, 

CH4 , and range at least as high as the compound C3!fi72 . Even these 

are again subdivided into a number of isomeric series the primary, 

secondary, and tertiary paraffins which, with equaLpercentage 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 CHo, and also by the physical characteristics of greater condensation. Methane, CH4 , for example, is gaseous; the middle members of the series are liquids, with regularly increasing boiling 

points; the higher members are solids, like ordinary paraffin. These 

hydrocarbons.are especially characteristic of the Pennsylvania petro619
620 THE DATA OP GEOCHEMISTEY.

leums, from which the following members of the series have been 

separated : a . ,

Paraffins from Pennsylvania petroleum.

Name.

1. Gaseous:

Propane .........................................................

2. Liquid: 

Pentane. ............................... '. ........................

3. Solid:

Formula.

CH4......

C2H6 ......

C3H8 ......

CiHio.....

C5Hi2-.-..

C6Hi4.....

C7H,6 .....

C8Hi8....-

C9H2o .-...-

CioHsa ....

CiiHS4....

CuHsB--..

'ClsH'28-.-.

CnHao....

CioHa-...

ClsHiM....

CigHiB....

C20H«....

C23H48-...

C24H5o....

C25H52....

C26H54-...

CzsHss----

CfflHM .-...

C34H70-...

Cj»H7S....

Melting 

point.

°C.

-186

-172. 1

- b\

- 31 .

- 26

- 12

+ 4

18

37

48

50-31

53-54

55-56

60

62-63

66

67-68

71-72

7G

Boiling 

point.

°C.

-164

 - 84. 1

- 37

+ 1

37

69

98

125

150

173

195

214

252

n For a description of these higher, solid paraffins, see C. F. Mabery, Am. Chem. Jour., 

vol. 33, p. 251', 1905. 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, p. 504, 1889) have described an artificial hydrocarbon, C0oHj~..

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 

C27H5G and C80H02 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,7j the total paraffins varied between 

94.13 and 95.73 per cent. Methane ran from 79.95 to 86.48 per cent 

and ethane from 7.65 to 15.09. The following analyses from other 

sources may be cited more in detail: c

Analyses of natural (/as.

 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. 

.Tour., vol. 16, p. 406, 1894. Selected from a table of seventeen analyses to show extreme 

variations.

" The table is condensed from H. Hofer's valuable work, Das Erdol, 2d ed., pp. 58-59, 

Braunschweig, 1906.

6 West Virginia Geol. Survey, vol. 1 A, p. 556, 1904.

« See also Mabery, Am. Chem. .Tour., vol. 18, p. 215, 1896, for analyses of gas, largely 

methane, from southern Ohio. Heifer (Das ErdOl, pp. 100-103) gives many other data. 

In Boverton Redwood's Petroleum and its Products, 2d. ed., vol. 1, pp. 246-250, 1906, 

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, p. 481, 1905. 

Many other analyses are published in Trans. Am. Inst. Min. Eng., vol. 15, pp. 529 et seq.
THE NATURAL HYDROCARBONS. 621

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. Kept. 

U. S. Geol. Survey, pt. 1, p. 592, 1891.

F. From Osawatamie, Kansas.0 Froai a table of seven analyses by B. H. S. Bailey, 

Kansas Univ. Quart., vol. 4, p. 1, 1895.

CH4 ......................................

CjH4,etc.................................

CO........................................

COs................ .......................

H2 . .......................................

Ni. .......................................

H2S.......................................

0S ........................................

A..

90.30

3.64

.1(10.00

B.

98.90

.40

.70

100. 00

C.

87.27

.41

12.32

none

100. 00

D.

93.56

.14

G.30

none

100. 00

E.

93.36

.28

.53

.25

1.76

3.28

.18

.29

99.93

F.

97.63

.22

1.32

.22

.60

trace

100.00

0 According to H. P. Cady and D. F. McFarland (Trans. Kansas Acad. Sci., vol. 20, p. 

80, 1907) the natural gas of Kansas contains helium. It was found in -14 samples, in 

amounts from 0.01 to nearly 2 per cent.

6 Largely CEU, with more or less ethane. CO not found by Phillips.

The analyses of Pennsylvania gases by S. P. Sadtler a gave somewhat different results. In gas from four different wells he found, 

in percentages, CH4 , 60.27 to 89.65; C2HC , 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 Pcdnt Abino, Canada, F. C. Philips & 

found 96.57 per cent of paraffins and 0.74 of H2 S.

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 defines, is parallel to the paraffin series, and the following 

members of it are said to have been isolated from petroleum.0

So-called " olefines " isolated from petroleum.

Name.

1. Gaseous:

2. Liquid:

3. Solid:

Formula.

C2H<......

C8H6 ......

C^He......

CsHio......

CCH12......

CrHn......

C8H,0 ......

C9H18 ......

Cl2H!K.....

CiaHM...-.

deHsj.....

Melting 

point.

. 65-66

62

Boiling 

point.

-103

- 18

- 5

+ 35

68

98

194

1 V?

172

1QC

91 ft

919 7

971

0 Second Geol. Survey Pennsylvania, Kept. L, pp. 146-160, 1876. Sadtler cites some 

analyses by other chemists.

"Jour. Am. Chem. Soc., vol.. 20, p. 696, 1898. 

 See H. Hofer, Das Erdol, p. 65.
622 THE DATA OF GEOCHBMISTEY.

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 ,<* however, the true defines, the," openchain " series, are present in petroleum at most in very small amounts. 

In Canadian petroleum Mabery and W. O. Quayle 6 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 c 

they also predominate in California petroleum.

Members of the series from C7H14 to Ci 5H30 were isolated from the 

California material. Mabery and S. Takano d also found that Japanese petroleum consisted largely of CnH2n hydrocarbons. Other similar occurrences are recorded in the treatises of Hofer and Redwood.6

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 

members are characteristic of oils from Texas, Louisiana, and Ohio. 

In oil from the Trenton limestone of Ohio, Mabery and O. H. Palm f 

found hydrocarbons having the composition C10H, 0 , C21H40 , C22H42 , 

and C24H4(i . With these compounds were members of the C,,H2n 

series as high as C17H34 . There were also members of the next series, 

CnH 2n_4 namely, C23H42 , C24H44 , and C25H46 . In petroleum from 

Louisiana, C. E. Coates and A. Best <J found the hydrocarbons C12H22 

and C14H26 . These, together with C10H., 0 , were also separated by 

Mabery h from Texas oils. These oils are furthermore peculiar in 

containing free sulphur, which separates out in crystalline form.* In

0 Jour. Am. Chem. Soc., vol. 28, p. 415, 1906. An important summary of our knowledge relative to the composition of American petroleums.

"Proc. Am. Acad., vol. 41, p. 89, 1905. 

'«Idem, vol. 36, p. 255, 1901.

d Idem, p. 295.

0 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.

f Am. Chem. Jour., vol. 33, p. 251, 1905.

a Jour. Am. Chem. Soc., vol. 25, p. 1153, 1903.

h Idem, vol. 23, p. 264, 1901. See also on Texas oils, C. Richardson and E. C. Wallace, 

Jour. Soc. Chem. Ind., vol. 20, p. 690, 1901; F. C. Thiele, Am. Chem. Jour., vol. 22, p. 

489, 1899; 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, 

p. 363, 1903 ; and N. M. Fenneman, Bull. U. S. Geol. Survey No. 282, 1906. Fenneman 

describes both Texas and Louisiana petroleums.

* See C. Richardson and E. C. Wallace, Jour. Soc. Chem. Ind., vol. 21, p. 316, 1902; 

and Thiele, Chem. Zeitung, vol. 26, p. 896, 1902.
THE NATURAL HYDROCARBONS. ' 623

petroleum from Santa Barbara, California, Mabery a discovered 

hydrocarbons of the three series CnH 2n_2 , CnH 2n_4, and CnH zn-» , 

represented by the formulae C13H24 , C16H30 , C17H30 , C18H32 , C24H44 , 

G,7H40 , and C20H50 .

Hydrocarbons of the series CnH sn-c, the " aromatic " or benzene 

series, occur in nearly all petroleums, but in usually subordinate 

amounts. Their empirical formuLe, ignoring the existence of isomeric compounds, are as follows:

Benzene_________________. ___ ___-_CflH0 

Toluene ^_____________ . _____ ______ ___C7H8 

Xylene . _. C8H10

Cumene________________..- - - _-!C8Hi2 

Cymene .. C10Hi4 

Etc.

According to Mabery, ** Pennsylvania petroleum contains small proportions of the lower members of this series, and Mabery and Hudson ° 

found larger amounts of them, especially of the xylenes, in California 

oil. Numerous other examples are cited by Hofer and Eedwood, but 

they need not be multiplied here. 1* Naphthalene, C10H8 , is the only 

compound of the series CnH2 n_i2 which has been certainly identified 

in petroleum. It was found by C. M. Warren and F. H. Storer ° in 

Rangoon oil, and also by Mabery arid Hudson in oil from California. 

In one of Mabery and Hudson's distillations of crude oil, so much 

naphthalene was present that the distillate became solid on slight 

cooling. Still more complex hydrocarbons have been found in petroleum residues, but it is possible that they were formed during the 

process of refining. It is not certair. that they were originally present 

in the natural oil/

In many petroleums small quantities of oxidized bodies are contained, sometimes complex acids, sometimes phenols. According to 

Mabery/ 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 \n 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

"Am. Chem. Jour., vol. 33, p. 270, 1905.

6 Jour. Am. Chem. Soc., vol. 28, p. 418, 190'3.

°Proc. Am. Acad., vol. 36, p. 255, 1890.

d In a memoir published since this text was written, R. Zaloziecki and J. Hausmann 

(Zeitschr. angew. Chernie, 1907, p. 1761) have called attention to the richness of Roumanian petroleum in aromatic hydrocarbons.

0 Mem. Am. Acad.. 2d ser., vol. 9, p. 208, 18'35.

f For data and references, see Hofer, Das Erdb'l, p. 74.

' Jour. Am. Chem. Soc., vol. 28, p. 59C, 1906.
624 THE DATA OF GEOCHEMISTRY.

they were discovered by S. F. Peckham,a and Mabery & 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 ° 

found normal sulphides of the paraffin series, and isolated ten compounds ranging from methyl sulphide, C2H0 S, to hexyl sulphide, 

C12H26S. In Canadian petroleum Mabery and Quayle d 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. 0

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 viscous, pasty semifluids; others are black, brittle solids, which resemble coal in their outward appearance. Albertite, grahamite, uintaite. 

and the so-called " pitch coal" of Oregon are familiar examples of 

these solid forms.

Many of the solid hydrocarbons have been described as mineral 

species and given specific names/ Scheererite, fichtelite, konlite, 

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

" Am. Join-. Sci., 3d ser., vol. 48, p. 250, 1894.

* Jour. Soc. Chem. Ind., vol. 19, p. 505, 1900. F. X. Bandrowsky (Monatsli. Cbemie, 

vol. 8, p. 224, 1887) and A. Weller (Ber. Deutsch. chem. Gesell., vol. 20, p. 2097, 1887) 

have detected nitrogenous bases in European oils.

<-Am. Chem. Jour., vol. 13, p. 233, 1891.

d Proc. Am. Acad., vol. 41, p. 89, 1905. 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, p. 

221, 1895, and also in Kcihler's treatise on asphalt.

" On sulphur in California petroleum, see S. F. Peckham, Proc. Am. Phil. Soc., vol. 36, 

p. 108, 1897. Also S. F. and I-I. E. Peckham, Jour. Soc. Chem. Ind., vol. 16, p. 996, 1897, 

on the sulphur content of bitumens.

f See Dana, System of Mineralogy, 6th ed., pp. 996-1024.
: THE NATURAL HYDROCARBONS. 625

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.a Most of these substances are found in 

small quantities, and are so imperf sctly described that they need no 

detailed consideration here. Others, like ozokerite, albertite, grahamite, uintaite, and the various as.phaltums 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 CnEL,n. In Caucasian ozokerite F. Beilstein and E. 

Wiegand 6 found a hydrocarbon to which they gave the name lekene, 

and which appears to be a polymer of CHr In the ozokerite 

of Utah paraffin predominates, of composition between C18HH8 and

C-H< ... ' Uintaite, or gilsonite,d is another black, brittle, lustrous mixture

of hydrocarbons found in the Urnta Mountains, Utah. Another 

similar mineral from Utah was named wurtzilite by W. P. Blake.c 

The exact nature of these hydrocarbons is yet to be determined. The 

same remark may be applied to the albertite f of New Brunswick, 

the grahamite o of West Virginia, the " pitch coal" h 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 tile oxidation of lighter oils; others, like S. F.

"Bitumen is also common in the New Almnden mines. Its association with-the lead 

and zinc ores of Missouri and with the copper-bearing shales of Mansfeld, Germany, 

is un occurrence of a different order, with wh:ch solfataric action has nothing to do.

"Ber. Deutsch. chem. Gesell., vol. .16, p. 15^.7, 1883.

c On Utah ozokerite, see .T. S. Newberry, Aia. .Tour. Sci., 3d ser., vol. 17, p. 340, 1879; 

and A. N. Seal, Jour. Franklin Inst, vol. 130, p. 402, 1800. A monographic paper on 

ozokerite by E. B. Gosling (School of Minec Quart., vol. 16, p. 41, 1894) contains a 

bibliography of the mineral. Der Erdwachssergbau in Boryslaw, by J. Muck, Berlin, 

1903, is an important monograph on ozokerite.

(l Uintaite has priority, but gilsonite is the name most commonly used. On this bitumen, see-J. M. Locke; Trims. Am. Inst. Min. ling., vol. 17, p. 162, 1887; K. W. Raymond, 

idem, vol. 18, p. 113, 1888; W. P. Blake, idom, vol. 18, p.. 563, 1890; G. H. Stone, on 

Utuh and Colorado asphalts, Am. .Tour. Sci., 3d ser., vol. 42, p. 148, 1891 ; and G. IT. 

Eldridge, .Seventeenth Ann. Rept. U. S. Geol. Survey, pt. 1, p. 915, 1896, and also Bull. 

No. 213, p. 296, 1903. A chemical Investigation of gilsonite by W. C. Day is reported in 

Jour. Franklin Inst., vol. 140, p. 221, 1895.

o Trans. Am. Inst. Min. Eng., vol. 18, p. 497, 1890 ; Eng. and Min. Jour., vol. 48, p. 

542, 1889; vol. 49, p. 106, 1890.

f C. H. Hitchcock, Am. Jour. Sci., 2d ser., vol. 39, p. "267, 1865 ; and S. F. Peckham, 

idem, vol. .48, p. 362, 1869.

» J. P. Lesley, Proc. Am. Phil. Soc., vol. 9, p.. 183, 1863 ; and I. C. White, Bull. Geol. 

Soc. America, vol. 10, p. 277, 1898. J. P. Kimball (Am. Jour. Sci., 3d ser., vol. 12, p. 

277, 1876) has described a "grahamite" from Mexico. 

*W. C. Day, Nineteenth Ann. Kept. U. S. Geol. Survey, pt. 3, p. 370, 1898.

14399 Bull. 330 08 iO
626 THE DATA OF GEOCHEMISTKY.

Peckham,0 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,6 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 two papers by Clifford Richardson. 0 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 

ammoniacal salts, which indicate that it is probably of volcanic ori- 

.gin. An analysis of the purified bitumen gave the following results:

Analysis of Trinidad bitumen. 

C ___________________________________________ 82. 33

H_____________________________________ 10.69 

S _____________r_____________________________ 6.16

N_______________________________________ .81

99.90

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

<* Peckham, loc. cit, and also Am. Jour. Sci., 3d ser., vol. 48, p. 389, 1894.

6 Am. Chemist, vol. 5, p. 359, 1875. For analyses of Texas grahamite see E. T. 

Dumble, Trans. Am. Inst. Min. Eng., vol. 21,-p. 601.

" Jour. Soc. Chem. Ind., vol. 17, p. 13, 1898; Rept. Inspector Asphalts and Cements, 

Washington, D. C., year ending June 30, 1892. See also N. S. Manross, Am. Jour. Sci., 

2d ser., vol. 20, p. 153, 1855. W. Merivale (Trans. North of England Inst. Mech. and 

Min. Eng., vol. 47, p. 119, 1898) has described the " manjak " of Barbadoes, an asphalt 

resembling that of Trinidad. See a'lso R. W. Ells, Ottawa Naturalist, vol. 23, p. 73, 19.07.
THE NATUBAL HYDKOCABBONS. 627

been active in hardening the bitumen; that is, in effecting the condensation and polymerization of the hydrocarbons.0 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. 6 He also describes the .Bermudez, Venezuela, locally.

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 c attempted to determine their exact 

nature by passing the gas through bromine. Organic bromides were 

thus formed, corresponding to the olefiries 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/' 

who dissolved spiegeleisen in hydrochloric acid. The gas evolved 

Avas 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 Liydrocarbons, with 325.5 grams of

°A well-known method for preparing H2i3 is to fuse paraffin with sulphur. The reaction doubtless involves a union of the residues from which hydrogen has heen partially 

withdrawn that is, the formation of a more condensed hydrocarbon molecule. The 

reaction does not seem to have been exhaustively studied. Some artificial "asphalts" 

j 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 gllsonite. See C. F. Mabery and .T. H. Byerly, Am. Chem. Jour., 

vol. 18, p. 141, 1896. See also references to the sulphur processes in Kohler's monograph, 

p. 119.

6 On the composition of asphalt, see also IT. Endemann, Jour. Soc. Chem. Ind., vol. 1C, 

p. 121, 1897. For analyses of Texas asphalts see H. W. Harper, Bull. No. 3, Texas Univ. 

Min. Survey, p. 108, 1902. Elaborate data are also given by G. H. Eldridge, Twentysecond Ann. Kept. U. S. Geol. Survey, pt. 1, p. 209, 1901, in a long paper on the asphalts 

and bituminous rocks of the United States. Important monographs on asphalt are by 

H. Ko'hler, 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, pp. 235-463, 1907, on petroleum and 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 Jrom going into details, and a vast literature 

must be passed over. The fundamental labors of Pelouze and Cahours in France, of 

Schorlemmer in England, of Markownikoff in Russia, and of others in nearly every country 

of Europe, can not be given the consideration here which is properly due them.

c Liebig's Annalen, vol. 129, p. 57, 1864. Hahn gives references to the earlier investigations.

*Am. Jour; Sci., 3d ser., vol. 6, p. 363, 1873.
628 THE DATA OF GEOCHEMISTBY.

bromides; and other experiments yielded similar results. The nature 

of the hydrocarbons was not further investigated.

Much more elaborate researches were those conducted by S. Cloez,a 

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, CsH15Br, 

from the bromine solution. In his second paper he described the 

products obtained during the solution of 600 kilograms of white cast 

iron, which yielded 640 grams of oily hydrocarbons, 2,780 grams of 

bromolefines, and 532 grams of paraffins. Seven-of the latter were 

identified, from C10H22 up to C16H34 , hydrocarbons identical with 

those which occur in petroleum. That is, from the carbides contained 

in cast iron, a mixture of hydrocarbons chemically resembling petroleum can be prepared.

In recent years, through the development of the electric furnace by 

Moissan, many carbides have been made and investigated. The 

greater number of these compounds react with water, yielding hydrocarbons, and. the production of acetylene, as an illuminating gas, from 

calcium carbide, has become an important industry. The metallic 

carbides, however, differ in their yield of hydrocarbons, and the 

results obtained may be summarized as follows: 6

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 

Jiquid and solid hydrocarbons. From 4 kilograms of uranium carbide Moissan obtained 100 grams of liquid hydrocarbons, consisting 

largely of defines, with some members of the acetylene series and 

some saturated compounds.

« Compt. Rend., vol. 78, p. 1565, 1874 ; vol. 85, p. 1003, 1877 ; vol. 86, p. 1248, 1878.

& See H. Moissan, Compt. Rend., vol. 122, p. 1462, 1896. Also a summary by J. A. 

Mathews, Jour. Am. Chem. Soc., vol. 21, p. 647, 1899. Berthelot (Compt. Rend., vol. 

132, p. 281, 1901) has discussed the reactions thermochemically.
THE NATURAL HYDROCARBONS. 629

The bearing of these observations upon theories of petroleum formation will be discussed later.

' It Avill be observed that acetylene is a common product of these 

reactions. But acetylene is not a constituent of petroleum. P. Sabatier and J. B. Senderens,0 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. 6 long ago proved that acetylene, 

when heated to the temperature at which glass begins to soften, polymerizes into benzene. Three molecules of C2H2 yield one of C(!H(i . 

Benzene itself, when heated under suitable conditions, loses hydrogen, 

and the residues combine to form diphenyl, C12H10 :

. 2C.H,-2H=C18H10+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 th?, final product may be very great. 

Furthermore, carbon and hydrogen can unite directly. When the 

electric "arc is formed between carbon terminals in an atmosphere of 

hydrogen, acetylene is produced a reaction discovered by Berthelot.6' 

According to W. A. Bone and D. S. Jerdan,d 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 WLS first applied to the production of 

an artificial petroleum by C. M, Warren and F. H. Storer e 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 f 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 bena Compt. Rend., vol. 134, p. .1185, 1903. Similar results to those of Sabatier and 

Senderens have recently been obtained by K. CbaritschkofE, Cheni, Zentrtilbl., 1907, p. 294.

"Ann. chim. phys., 4th ser., vol. 12, p. 52, 1867.

c Idem, 3d ser., vol. 67, p. 64, 18G3.

d Jour. Chem. Soc., vol. 7.1, p. 41, 1897 ; vol. 79, p. 1042, 1901. See also T. N. Pring 

and R. S. Button, idem, vol. 89, p. 1591, 1906.

" Mem. Am. Acad., 2d ser., vol. 9, p. 177, 1865.

'Coal oil is oil distilled from shale or ?oal. The term is not synonymous with petroleum, although it is often, loosely, so use!.
630 THE DATA OF GEOCHEMISTRY.

zene, toluene, xylene, and isocumene, members of the aromatic series. 

A true artificial petroleum had been prepared.

In 1888 C. Engler's famous investigations 0 were made public. He^ 

distilled menhaden oil, unsaponified, at a temperature between 320° 

and 400°, and under a pressure of ten atmospheres. The distillate 

resembled petroleum, and contained the paraffins from C5H12 up to 

C7H10 . In a later memoir 6 he mentions the isolation of normal octane and nonane, with secondary hexane, heptane, and octane. In a 

still later research with T. Lehmann c he also obtained olefines from 

C0Ii12 up to C9H18 and some derivatives of the benzene series. These 

experiments upon fish oil confirmed those of Warren and Storer, but 

differed from theirs in the direct use of the oil instead of its fatty 

acids alone. The lime soap of the American chemists contained only 

the acids of the oil, separated from its glycerine; the entire oil was 

used by Engler. From his crude product Engler also prepared 

an illuminating oil, practically indistinguishable from commercial 

kerosene/

Analogous experiments, but with a somewhat different purpose, 

were carried out by W. C. Day.6 A mixture of fish (fresh herring) 

and resinous pine wood was distilled from an iron retort, the process 

being continued to complete carbonization of the residual material. 

The distillate consisted of a mixture of oil and water, and "the oil, 

upon redistillation, yielded 4 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/ for example, established this fact with 

regard to linseed oil, but the nature of the product was not completely 

determined. Engler g obtained hydrocarbons by the distillation of 

colza and olive oils, as well as from fish oil, butter, and beeswax. 

Furthermore, J. Marcusson ft 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.

°Ber. Deutsch. chem. Gesell., vol. 21, p. 1816, 1888. .

"Idem, vol. 22, p. 592, 1889.

* Idem, vol. 30, p. 2365, 1897.

d Observations confirmed by Redwood, Petroleum and its Products, 2d ed., vol. 1, p. 259.

e Am. diem. Jour., vol. 21, p. 478, 1899.

fProc. Am. Phil. Soc., vol. 36, p. 93. "

" Cong. internat. du pe'trole, Paris, 1900, p. 20.

"Chem, Zeitung, vol. 30, p. 789, 1906. . - .
THE NATURAL HYDROCARBONS. 631

ORIGIN OF PETROLEUM.

Probably no subject in geochemistry has been more discussed than 

that of the origin of petroleum. Theory after theory has been proposed, and controversy is still active. The evidence is abundant, but 

contradictory, and leads to different conclusions when studied from 

different points of view.

The theories so far advanced may be divided into two categories 

the inorganic and the organic. Let us examine the hypotheses separately. The earlier speculations connecting the formation of petroleum with volcanic phenomena may be passed over, for the reason that 

they were framed at a time when essential evidence was not available. 

They were speculations, nothing more. The modern era begins with a 

memoir by M. Berthelot,a 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 irom 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 ofi;-cited paper by H. Byasson,6 which 

has no present value, we come next to the famous carbide theory of 

D. Mendeleef,0 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.

Mendeleef'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 Mbissan, in his 

development of the electric furnace, and has had many advocates. 

Moissan d himself has adopted it, and also suggested that volcanic ex-

«Ann. chim. phys., 4th set1 ., vol. 9, p. 481, 1866.

6 Compt. Rend., vol. 73, p. 611, 1871. A later, separate brochure by Byasson I have 

not seen.

«Ber. Deutsch. chem. Gesell., vol. 10, p, 229, 1877; Jour. Chem. Soc., vol. 32, p. 283. 

See also Mendele'ef's Principles of Chemistry, English translation, vol. 1, pp. 364-366, 

1891.

<* Compt. Rend., vol. 122, p. 1462, 1896. See also S. Meunier, idem, vol. 123, p. 1327, 

1896.-
632 THE MTA OF GEOCHEMISTRYplosions 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 a 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 O. Silvestri,6 who found in basaltic 

lavas from near Etna both liquid oils and a solid paraffin which 

melted at 56°. These hydrocarbons, as well as the marsh gas, may 

conceivably have been formed either through a direct union of carbon 

and hydrogen or from material distilled by volcanic heat out of 

adjacent sedimentary rocks. None of the possible hypotheses to account for their origin is definitely conclusive.

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,0 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/ cases in which the possibility 

of an organic origin seems to be absolutely excluded.

Tlje other speculation is that of O. C. D. Ross,e who has tried to 

show that petroleum may originate from the action of solfataric 

gases upon limestones. Ross wrote various chemical" equations to 

show how the reactions might occur, but they are improbable and 

experimentally unverified.

It will be seen, upon consideration, that these inorganic theories 

concerning the origin of petroleum relate not only to its proximate 

genesis, but to fundamental questions of cosmology. Sokoloff's 

hypothesis is an indication of this fact, and the assumption of carbides within the earth represents an effort in the same direction. An 

illustration of this implication is to be found in Lenicque's remarkable memoir/ 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 Jater. Un-

« See ante, Chapter VIII. ->

"Gazz. chim. ital., vol. 7, p. 1, 1877; vol. 12, p. 9, 1882.

c Bull. Soc. imp. nat. Moscou, new ser., vol. 3, p. 720, 1890.

rf.See F. Wohler, Liebig's Annalen, vol. 109, p. 349, 1859, on carbon compounds in the 

meteorite of Kaba, Hungary. Also S. Meunier, Compt. Rend., vol. 109, p. 976, 1889, on 

the meteorite of Mighei, Russia. A. E. Nordenskiold (Pogg. Annalen, vol. 141, p. 205, 

1870) found carbonaceous matter in the meteorite of Hessle, Sweden; and G. Tschermak 

(Sitzungsb. Akad. Wien, vol.-62, Abth. 2, p. 855, 1870) 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.. Clpe'z, Compt. Rend., vol. 59, p. 37, 1864. Graphite and amorphous carbon are common In meteorites, and in some falls diamonds have been found.

« Chem. News, vol; 64, p. 14, 1891. A criticism by Redwood appears on p. 215..

t Mem. Soc; ingSn. civils, France, October, 1903, p. 346.
THE NATURAL HYDfiOCAESOHS. 633

der such conditions some carbides might remain unoxidized through 

man}* 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 traceable to such a source are altogether insignificant. Bitumens occur in small amounts in many 

igneous rocks, but never in large volume. They are, moreover, absent, at least in significant proportions, from the Archean, and first 

appear abundantly in Paleozoic time. From the Silurian upward 

they are plentiful, and commonly remote from great indications of 

volcanic activity. Even such an occurrence as that of the Pitch 

Lake in Trinidad, where asphalt is associated with thermal waters, 

does not necessarily imply a community of origin. It is at least 

conceivable that the solfataric springs may have acted upon sedimentary accumulations of oil, partly by vaporizing the latter and 

so bringing it to the surface, and partly by effecting, with the aid of 

steam and sulphur, the condensations or polymerizations that are 

observed. These considerations serve to show the need of great 

caution in dealing with this class of problems and to warn us against 

hasty generalizations. Speculations based upon individual occurrences of petroleum are of very little value. The entire field, in all 

of its complexity, must be taken into account.0 ;

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 6 which occurs in the drift and seems to be of vegetable origin. Buried vegetation alone can account for its development under 

the observed conditions.

Apart from the natural occurrences of marsh gas, either in swamps 

or as the "fire damp" of coal mines, its artificial production has been 

studied experimentally. F. Hoppe-Seyler c and H. Tappeiner a have

" For an elaborate argument in favor of the volcanic origin of natural gas and oil, see 

E. Coste, Jour. Canadian Min. Inst., vol. (' , p. 73, 1903. A preliminary notice is given 

in vol. 3, p. 68, of the same journal, and an abstract in Eng. and Min. Jour., vol. 75, 

p. 439. See also Trans. Am." Inst. Min. Eng., vol. 35, p. 288, 1905.

" See A. G. Leonard, Proc. Iowa Acad. Sc:., vol. 4, p. 41. F. M. Witter (Am. Geologist, 

vol. 9, p. 319, 1892) has described a gas woll, about 100 feet deep, near Letts, Iowa.

" Ber. Deutsch. chem. Gesell., vol. 16, p. 122, 1883.

'' Idem, pp. 1734, 1740. See also L. Popoff, abstract in Jour. Chem. Soc., vol. 28, p. 

1209, 1875, on gas from river mud near sewer openings.
634 THE DATA OF GEOCHEMISTRY.

shown that it is formed by the fermentation of cellulose, together 

with carbon dioxide and free hydrogen. During the decay of seaweeds, however, according to F. C. Phillips,* 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 

hydrqcarbon 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.6 Engler c 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 d 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 e holds 

that the changes are always in the opposite direction and that the 

more complex hydrocarbons are formed first, partially breaking 

down afterwards into lower members of the series. J. Marcusson f 

holds the same view. The putrefactive removal of the albuminoid

0 Am. Chem. Jour., vol. 16, p. 427, 1894.

6 For a very complete summary of all the hypotheses relative to the formation of 

petroleum, see Hofer, Das Erdol, pp. 160-229, 1906. See also Redwood, Petroleum and 

its products, vol. 1, pp. 250-261, 1906. Other summaries are by Aisinmann, Zeitschr. 

angew. Chemie, 1893, p. 739 ; idem, 1894, p. 122; C. Klement, Bull. Soc. beige g6ol., 11, 

proc. verb., p. 76, 1897; R. Zuber, Zeitschr. prakt. Geol., 1898, p. 84, and B. Orton, Bull. 

Geol. Soc. America, vol. 9, p. 85, 1897. Very recent memoirs on the subject are by P. 

De Wilde, Arch. sci. phys. nat, 4th ser., vol. 23, p. 559, 1907, and C. Neuberg, Sitzungsb. 

K. preuss. Akad., May 16, 1907.

c Ber. Deutsch. chem. Gesell., vol. 30, p. 2358, 1897.

" The importance of pressure in petroleum formation was also urged by G. Kramer 

and W. Bottcher (Ber. Deutsch. chem. Gesell., vol. 20, p. 595, 1887), in their comparison 

of the hydrocarbons contained in petroleum and coal oil or tar. H. Monke and F. 

Beyschlag (Zeitschr. prakt. Geol., 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., vol. 28, p. 429, 1906. 

. Zeitung, vol. 30, p. 788, 1906.
THE NATURAL HYDROCARBONS. , 635

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 ° 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 l 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,0 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,'7 for 

instance, has sought to connect the formation of petroleum Avith 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. F. Heusler e also, while indorsing Engler's principal 

conclusions, invoked the aid of aluminum chloride- as an agent in" 

effecting a polymerization of the hydrocarbons. According to Ochsenius's theory, magnesium 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

0 Cited by A. Jaccard, Arch. sci. phys. nat., 3d ser., vol. 24, p. 106, 1890.

6 Ber. Deutsch. chem. Gesell., vol. 33, p. 16, 1900. See also Gong. Internal du 

pfitrole, 1900, p. 30.

c Cited by Hofer, Das Erdb'l, p. 219, 1906. F. Hornung (Zeitschr. Deutsch. geol. 

Gesell., vol. 57, Monatsber., p. 534, 1905) argues in favor of fishes as the raw material 

of petroleum. See also J. J. Jahn, Jahrb. K.-k. geol. Reichsanstalt, vol. 42, p. 361, 1892. 

For arguments against the theory of Engler, see D. Pantanelli, Bull. Soc. geol. itnl.,-vol. 

25, p. 795, 1906. Pantanelli seems to favor the inorganic origin of petroleum.

d Chem. Zeitung, vol. 15, p. 935, 1891, and Zeitschr. Deutsch. geol. Gesell., vol. 48, p. 

239, 1896. See also his papers cited in Chapter VII, ante.

 Zeitschr. angew. Chemie, 1896, pp. 288, 318.
636 THE DATA OF GEOCHEMISTRY. .

chloride occur in any notable quantity in natural waters.*1 A more 

probable function of the salts, according to R. Zaloziecki,6 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-0 has shown 

that in small bays off 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 d 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. 6 Furthermore, Mendeleef'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, 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

a A possible exception to this statement is cited by Ochsenius (Zeitschr. Deutsch. geol. 

Gesell., vol. 48, p. 239, 1896), who mentions a water containing, in its solid residue, 

23.91 per cent of A1C13. This water accompanied a petroleum.

»Chem. Zeitung, vo). 15, p. 1203, 1891. 

1 c Idem, p. 1582.

d Bull. Soc. sci. nat. Neuchfitel, vol.- 8, p. 58, 1868. See also F. C. Phillips, Proc. Am. 

Phil. Soc., vol. 36, p. 121, 1897, on petroleum inclosed in fossils.

* 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.
THE NATURAL HYDROCARBONS. 637

same lines. L. Lesquereux,0 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 6 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. Kedwood c 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 phe.- 

nomena are probably not exceptional and deserve a more precise 

examination than they have received hitherto. An observation by 

W. L. Watts d 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 e 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. 

PeckhanV 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.

In 1843 E. W. Binney and J. H. Talbot h 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. Newa Bull. Soc. sci. nut. Neuchatel, vol. 7, p. 234, 18C6.

6 See discussion following Lescjuereux's communication.

c Petroleum and its products, 2d ed., vol. 1, pp. 126, 142.

"BuH. No. 19, California State Mining Bur., p. 202. See also Bull. No. 3 for more 

details. In Bull. No. 16, 1890, A. S. Cooper discusses at length the genesis of petroleum 

and asphalt in California. Bulls. Nos. 31 and 32 also relate to this subject.

» Corapt. Rend., vol. 117, p. 593, 1893. See also Bertrand, Compt. Rend. VIII Cong. 

geol. intermit., 1900, p. 458.

f Geology of Ohio, vol. 1, p. 158, 1873. See also an earlier paper by Newberry, Rock 

Oils of Ohio, in Fourteenth Ann. Rept. Ohio State Board Agric., p. 605, 1859.

» Proc. Am. Phil. Soc., vol. 10, p. 445, 1868 ; vol. 37, p. 108, 1898.

? Published in Trans. Manchester Geol. Soc., vol. 8, p. 41, 1868. Curiously, a later 

paper by Binney appears earlier, namely, in vol. 3, p. 9, 1860.
THE DATA OP GEOCHEMISTRY.

berry,0 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 folloAving investigations seem to bear upon 

the problems suggested by these observations: .

In 1899 A. F. Stahl & and, independently, G. Kramer and A. Spilker c 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.'* 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 alga3, 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 Avith reference to the adequacy of the proposed 

source, it is well to remember the enormous accumulation of " oozes," 

namely, the radiolarian and globigerina oozes, on the bottom of the 

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. ^

°Ann. New York Acad. Sci., vol. 2, p. 277, 1882.

" Chem. Zeitung, vol. 23, p. 144, 1899. Also note in vol. 30, p. 18, 1906.

c Ber. Deutsch. chem. Gesell., vol. 32, p. 2940, 1899 ; vol. 35, p. 1212, 1902. Criticism 

by Bugler in vol. 33, p. 7, 1900.

d See also C. E. Guignet, Compt. Rend., vol. 91, p. 888, 1880, on wax from peat.

«Natur. Wochenschr., vol. 20, p. 599, 1905.

f These oceanic sediments are especially noticed by Bngler in a paper read before the 

petroleum congress in 1900 (Cong. internat. du pe"trole, Paris, 1900, p. 28). In A. 

Beeby Thompson's monograph, The Oil Fields of Russia, pp. 85-87, London, 1904, 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.
THE NATUBAL HYDKOCAEBONS. 639

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,0 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.6

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,0 

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. These 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 d has said, disseminated petroleum is wellnigh universal; the accumulations are rare. In certain districts 

the shales and limestones are generally impregnated with traces of'

a Eclog. Geol. Helvet, vol. 2, p. 87, 1890. See also Arch. scl. phys. nat., 3d ser., vol. 

23, p. 501, 1890; vol. 24, p. 106, 1890. Jaccard studied especially the bitumens of the 

Jura.

6 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. Kept., 1904 ; E. Haworth, Univ. Geol. Survey Kansas, vol. 1, p. 

232, 1896; H. P. H, Brumell, Geol.. Survey Canada, new ser., Ann.. Kept. 5, Q, 1893; 

and W J McGee, Eleventh Ann. .Rept. U. S. Geol. Survey, pt. 1, p. 589, 1891. L. I-Iarperath (Bol. Acad. nac. cien.'C6rdoba (Argentina), vol. 18, p. 153, 1005) has published a 

long memoir on petroleum and salt.

" c Chem. Zeitung, vol. 30, pp. 391, 1155, 1168, 1906. Walden cites many examples of 

this optical activity. See also a criticism by Engler, idem, p. 711, and a papev by 

Rakusin, p. 1042. Another memoir, by J. Marcusson, appears in vol. 31, p. 419, 1907.

<* First Ann. Rept. Geol. Survey Ohio, chapter 11, 1890; Geol. Survey Kentucky, Report 

on Occurrence of. Petroleum, etc., 1888-89.
640 THE DATA OF GEOCHEMISTRY.

H

bitumens, which seem at first sight to be insignificant, but which 

really represent enormous quantities. In the Mississippian (" subCarboniferous ") 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,0 

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, in- . 

closing either animal or vegetable matter, there bitumens may be 

produced. The presence of water, preferably salt, the exclusion of 

air, and the existence of -an impervious protecting stratum of clay 

seem to be essential conditions" toward rendering the transformation 

possible. Seaweeds, mollusks, crustaceans, fishes, and even microscopic organisms of many kinds may contribute material to the 

change. In some cases plants may predominate; in others animal remains; and the character of the hydrocarbons produced is likely to 

vary accordingly, just as petroleum varies in different fields. In one 

region we find chiefly paraffins, in another naphthenes, and in another nitrogenous or sulphureted oils. Such differences can not be 

ignored, and they are most easily explained on the supposition that 

different materials have yielded the different products. On this 

class of problems the chemist, the geologist, and the paleologist must 

work together. Physics also is entitled to be heard; for, as D. T. 

Day & 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.

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. 0 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-.

a Chemical and Geological Essays, p. 168, 1875. "'

»Cong. internat. du pfitrole, Paris, 1900, p. 53.

c For a discussion of this problem, see H. HOfer, Das Erdol, p. 223, 1906. Also G. I. 

Adams, Trans. Am. Inst. Min. Eng., vol. 33, p. 340, 1903; and D. T. Day, idem, p. 1053. 

Orton's reports, previously cited, contain important contributions on this theme.
THE NATUBAL HYDEOCARBONS. 641

>

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. 

14399 Bull. 330 08 41
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 of 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 

C6H10O5 , which gradually loses carbon dioxide, marsh gas, and water, ^ 

and so yields the series of products represented by the different kinds 

of coal.a This assumption, like most other assumptions of its class, is l 

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 com- ^ 

position of wood, we shall have a better starting point for our series 

of derivatives. Wood or woody fiber is by no means the only substance to be considered, but it is the most important one, and its 

ultimate composition has been well determined. Its proximate composition is not so clearly known, but certain available facts are per-

°The formula C8Hio05 represents only the empirical composition of cellulose, and not -^ 

its true molecular weight. According to A. Nastukoff (Ber. Deutsch. chem. Gesell., vol. 

33, p. 2237, 1900), the true formula is probably 40C0Hi0OB, or C^oHiooOaoo- This may be 

an exaggeration, but the molecular weight of cellulose is certainly high. f

642
COAL. 643

tinent to the present discussion. It contains cellulose, C0H10O5 , and 

a substance known as lignone, lignin, or lignocellulose, in about 

equal proportions, together with other minor organic constituents, 

such as gums and resins,* and some inorganic matter which forms its 

ash. To lignocellulose, according to Cross and Bevan,6 the formula 

C12Hj 8O0 ma}'- 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 ivood. 

A. The composition of cellulose, calculated, from its formula.

B. The composition of lignocellulose, similarly computed.

C. The average composition of twenty-four woods, analyzed by Petersen and Schodler, 

Liebig's Annalen, vol. 17, p. 139, 1836. Samples dried and finely powdered.

D. Average of thirty-six analyses of five different woods, by B. Chevandier, Ann. chim. 

phys., 3d ser., vol. 10, p. L29, 1844. Samples dried in vacuo at 140°.

E. Average of eight analyses of woods by W. Baer, .Tahresb. Chemie, 1847-4S, p. 1112. 

Ash from 0.53 to 2.03 per cent.

F. Average of seven Danish woods, analyzed by B. Gottlieb, Jour. Chem. Soc., vol. 46, 

p.'477, 1884 (abstract). Dried at 115°.

G. Average composition of five acrogen plants, of the genera Lycopodium, Equisetum, 

A.spidium, and Gyathea, by G. W. Hawes, Am. Jour. Sci., 3d ser., vol. 7, p. 585, 1874. 

In Equisetum the'ash ran as high as 11.82 per cent.

C.. ..........................................

H... .........................................

O. ...........................................

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

44.80

100.00

All of these analyses are recalculated to ah 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 analyses the nitrogen 

ranged from 1.21 to 2.17 per cent. The differences between the wood 

analyses are principally due to differences in drying.

From these figures we see that cellulose contains about 5 per cent 

more oxygen than carbon, while in wood the reverse statement is very 

nearly true. Even lignocellulose contains less carbon than is actually 

found in wood. The figures for wood given in column F approximate 

very nearly to the formula C0H9O4 , and that expression might be 

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.

0 See M. Singer, Monatsh. Chemie, vol. 3, p. 395, 1882, on the subordinate constituents of wood. The subject is one which can not be properly developed here. 

"Jour. Chem. Soc., vol. 55, p. 199, 1889.
644 THE DATA OF GEOCHEMISTRY.

It is generally admitted, I think, by all competent investigators, 

that coal originated from vegetation which grew in swampy or 

marshy places. As the vegetation died it' underwent a partial decay 

and was buried under successive layers, either of matter like itself, or 

else of sediments such as clay. In that way it was protected from 

complete atmospheric oxidation, and at the same time subjected to 

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 of lignite represent submerged forests; and in others, as 

shown by many geologists, the coal was probably formed, not from 

vegetation in place, but from drifted materials, a condition, however, 

which does not affect the chemistry of the carbonizing process. The 

slow decay of the buried substances is the essential thing for the 

chemist to consider. With the vegetable matter some animal remains were undoubtedly commingled, helping to increase the nitrogen content of the coal; and the ash of the latter was augmented by 

more or less inorganic sediment, derived from the wash of the land 

in times of flood.

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 v 

remnants are found. Amber, fossil copal, the waxes found in peat 

bogs, and a multitude of similar substances have been thus preserved. 

In lignite and bituminous coal, aggregations and often large masses 

of resinous bodies not infrequently occur, and, in a disseminated 

form, unrecognizable by the eye, they must be almost invariably present. Their quantity, of course, would depend upon the exact character of the vegetation from which a given coal bed was formed. 

The nature and distribution of the fossil resins deserve much more 

careful study than they have yet received. Much rarer than the 

resins are the salts of organic acids, which are sometimes found in 

coal, especially in lignite. Three of these are well-defined species, 

namely, whewellite, calcium oxalate; humbpldtine, ferrous oxalate; 

and mellite, the aluminum salt of mellitic acid, A1CG O6 .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
COAL. 645

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 b 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, P. Black peat.

G. Heavy brown peat.

C............'.................................

H............................................

0....... .....................................

N.. ...:......................................

A.

49.88

0.54

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.

19 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.

fi9 U

6.81

29.24

1.41

100.00

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: c

Analyses of peat.

A. From Thesy, France. Analysis by Marsilly, Ann. mines. 5th ser., vol. 12, p. 406. 

Dried twenty-four hours in vacuo.

" On the rapidity of formation of peat, see a summary by G. H. Ashley, Econ. Geol., 

vol. 2, p. 34, 1907.

» Jour, prakt. Chemie, vol. 92, p. 65, 1864.

r- For still other analyses, see Roth and Percy, as cited, and vol. 1 of Groves and 

Tl»rp's Chemical Technology, pp. 14-20. In the latter work, p. 16, wiiJ 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. Iviimmel (Econ. Geol., vol. 2, p. 24, 1907) there a-re many 

technical analyses of New Jersey peat, with calorimetric data. On the mechanise of 

peat formation, see N. S. Shaler, Sixteenth Ann. Kept. U. S. Geol. Survey, pt. 4, p. 305, 

1895. An important general paper on peat, Its rate of growth, its resins, etc., by R. 

Angus Smith, is given in Mem. Lit. Pb.il. Soc. Manchester, 1876, p, 281.
646 THE DATA OF GEOCHEMISTRY.

B. From Camon, France. Also by Marsilly, who gives seven analyses in all. Dried 

twenty-four hours in vacuo.

C. From " Ho'r in Schonen." Analysis by 0. Jacobsen, Liebig's Annalen, vol. 157, p. 

240, 1871. Dried at 100°.

D. From a lake in Cashmere. Analysis by C. Tookey. See Percy's Metallurgy, vol. 1, 

p. 206, 1875.

E. Average of ten analyses cited by Roth, Allgem. chem. Geol., vol. 2, p. 642.

C............ ........................................

H..... ...............................................

0...... .............................................

N...................................................

Ash.................................................

A.

50.67

5.76

34.95

1.92

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

Keduced 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 red'iiced to ash-free basis.

C... .................................................

H.... ...............................................

O...... .............................................

N...................... .............................

A.

54.31

6.18

37.46

2.05

100.00

B.

50.89

6.61

39.58

2.92

100.00

C.

54.10

6.83

37.30

1.77

100.00

D.

55.67

6.11

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 and partly due to the property which the humus compounds possess of absorbing nitrogen from the air to form the so-called azohumic acids.*

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 rather ill-defined' 

bodies, and various formula? 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 in 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

" This subject was considered in Chapter III, ante, p. 83.
COAL. 64T

in producing the changes observed. On this point, however, there 

is some doubt, Friih and Schroter,* 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 acids. From this point of view H. Borntrager 6 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.0 According 

to F. G. Kaufmann,d 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 Miihlberg of dopplerite from the peat 

of Obbiirgen, Canton Unterwalden, Switzerland, which, in mean, are 

as follows: .

Average composition of dopplerite.

G _________________________ ___________________ 56.46

H ___________________- ____-___________ 5.48

O+N ______________________________________ 38. 06

100.00.

The organic portion of dopplerite from the original locality at 

Aussee, Styria, gave W. Demel e nearly identical results, and he asn 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, 

Coiiipt. Rend., vol. 127, p. 825, 1898.

"Zeitschr. anal. Chemie, vol. 39, p. 694, 1900; vol. 40, p. G39, 1901.

n See Dana, System of Mineralogy, 6th ed., p. 1014. For additional data on dopplerite, see C. Claesson, Chem. Zeitung, vol. 22, p. 523, 1898, and W. Alexejeff, Zeitschr. 

Kryst. Min., vol. 20, p. 187, 1902.

 *.Tahrb. K.-k. geol. Reichsanstalt, vol. 15, p. 283, 1885.

« Ber. Deutsch. chem. Gesell., vol. 15, p. 2961, 1882.
()48 THE DATA OF GEOCHEMISTRY.

signs to the substance the formula C12H14 00 . Its actual occurence 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 a 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.6 C. Hell 

assigned it the formula C30H54 , and L. Spiegel has argued in favor 

of C18H30.C 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 inchest In various localities peat beds 

have been found buried beneath sediments or drift. Dawson e mentions peat underlying bowlder clay in Cape Breton Island, and beds 

covered by drift have been reported in lowa.f 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.*7

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 

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

a Liebig's Annalen, vol. 157, p. 240, 1871. See also Mulder, idem, vol. 32, p. 305, 1839.

" On ficbtelite, see T. B. Clark, Liebig's Annalen, vol. 103, p. 236, 1857; C. Hell, Ber. 

Deutsch. chem. Gesell., vol. 22, p. 498, 1889 ; E. Bamberger, idem, p. 635, and L. Spiegel, 

idem, p. 3369. Also M. Schuster, Min. pet. Mitth., vol. 7, p. 88, 1885.

oReduced'to simpler, comparable terms, these formulae become, respectively, C^H^ and 

C1BH25. The difference is slight. .

d See G. H. Ashley, Econ. Geol., vol. 2, p. 34, 1907.

« Acadian Geology, 2d ed., p. 68.

f See T. H. MacBride, Proc. Iowa Acad., vol. 4, p. 63, 1897 ; and T. E. Savage, idem, 

vol. 11, p. 103, 1903.

' On American peats, see H. Ries, Fifty-fifth Ann. Kept. New York State Mus., p. r55, 

1903; A. L. Parsons, idem, Fifty-seventh Atin. Kept., vol. 1, p. 16, 1905. Parsons cites 

many analyses. In Ann. Kept. State Geologist New Jersey, 1905, p. 223, W. E. McCourt 

and C. W. Par melee 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.
COAL. 649

even, by metamorphic action, into anthracitic varieties." 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.6

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 Avhich 

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.0 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/1 show this fact clearly. They have been recalculated upon an ash-free, water-free basis.

Analyses of foreign lignites.

A. From Teuditz, 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. ..................................................

O+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

C.52

11.22

100.00

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

" These transformations have been doubted by Donath, whose work is cited later.

6 See, for example, A. Daubre'e, Compt. Rend., vol. 19; p. 126, 1844, on " mineral charcoal " from the Saarbriicken coal field.

c See P. E. Spielmann, Chem. News, vol. 94, p. 281, 1906. For an analysis of Spanish 

jet see J. B. Boussingault, Ann. chim. phys., 5th ser., vol. 29, p. 382, 1883. The latter 

memoir contains many other analyses of fossil combustibles. -

d 1875 edition, vol. 1, pp. 312-313. From a table of 41 analyses.
650 THE DATA OF GEOCHEMISTRY.

contain sulphur, which is partly organic, partly present as inclosures 

of pyrite or marcasite, and partly in the form of sulphates, such as 

gypsum.® The following analyses from the reports of the fuel-testing plant of the United States Geological Survey 6 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.

B. Black lignite from Red Lodge, Montana. 0

Ash.................................................

A.

16.70

37.10

39.49

6.71

100.00 

.63

B.

22.48

31.36

26.73

19.43

100.00 

.56

C.

18.51

35.33

30.67

15.49

100.00 

3.05

D.

17.69

07 Qfi

39.56

d 70

100.00 

.03

E.

9.05

36.70

43.03

11.22

100.00

"A coal of doubtful character. Not certainly lignite.

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. ..................................................

O...... .............................................

A.

72.62

4.93

1.20

21.25

100.00

B.

73.63

5.07

1.35

19.95

100.00

C.

75.19

6.18

1.04

17.59

100.00

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.

Average analyses of lignites.

A. Average of 22 Texas lignites, analyzed by Magnenat and Wooten. Dried at 105°. 

From E. T. Dumble'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.

a The resinoid substances which have been named tasmanite and trinkerite are rich 

in organic sulphur compounds of undetermined character. See Dnna, System of Mineralogy, 6th ed., p. 1010.

"Prof. Paper No. 48, pt. 1, and Bull. No. 290, 1906. Analyses made under the direction of E. E. Somermeier.
COAL. 651

c..... ............................... ......................................

H...... ..........................-.....................................:..

0................ ........................................................

N. ........................................................................

A.

69.82

4.72

[ 25. 40

.

100.00

B.

74.86

6.32

18.51

1.31

100.00

C.

74.17

5.67

| 20. 16

100. 00

Data of this kind might be almost indefinitely multiplied/'

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,6 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,0 who, in a Japanese lignite, found 9.5 per cent of substance soluble in benzene.

In their behavior toAvard reagents the lignites are more akin' to 

peat than to the Carboniferous coals. Like peat, they contain humic 

compounds which are soluble in solutions of caustic alkalies. According to E. Fremy,* peat yields abundant " ulmic acid " to alkaline solvents, xyloid lignite yields less, and compact lignite little or 

none at all. The bituminous coals and anthracite are insoluble in 

alkaline solutions. Occasionally these humic bodies are found in 

remarkable'Concentrations. The " paper coals " of Russia, for example, contain layers of humic matter, which is soluble in ammonia." 

In the brown coal of Falkenau, Bohemia, C. von John f found a 

native humus acid, soluble, in ammonia or sodium carbonate- solution, which had approximately the composition C40H4602r,; Von 

John cites other examples reported by other observers. Furthermore, the pigment known as Cassel brown is a fossil humus from the 

Tertiary near Cassel, Germany."

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

a See the great monograph by C. Zincken, Die Physiographic der Braunkohle, Hannover, 

1867 ; and its Ergiinzung, 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 Brennstoffie, vol. 1, Braunschweig, 1897. B. F. Burchard, In 

Proc. Sioux City (Iowa) Acad., vol. 1, p. 174, 1904, has reported data for some Nebraska 

lignites.

6 See E. Donath, Zeitschr. anorg. Chemie, 1906, p. 657.

« Jour. Soc. Chem. Ind., 1891, p. 975.

"Compt. Rend., vol. 52, p. 114, 1861.

« See R. Zeiller, Bull. Soc. geol., 3d ser., vol. 12, p. 680, 1884.

' Verhandl. K.-k. geol. Reichsanstalt, 189.1, p. 04.

' See a recent description by P. Malkomesius and R. Albert, .Tour, prakt. Chemie, 2d 

ser., vol. 70, p. 509, 1904.
652 THE DATA OP GEOCHEMISTRY.

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,a 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.6 A committee of the British Association c 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 d have studied one 

phase of the nitric acid reaction with much care. Dilute nitric acid, 

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

"Compt. Rend., vol. 88, p. 590, 1879.

"Proc. Chem. Soc., vol. 8, p. 9, 1892. W. C. Anderson and J. Roberts (Jour. Soc. 

Chem. Ind., vol. 17, p. 1013, 1898) have also studied the action of nitric acid on coal, 

and made several analyses of the " coal acids " so obtained.

c Ann. Rept. Brit. Assoc., 1894, p. 246.; idem, 1896, p. 340.

"Donath, Chem. Zeitung, 1905, p. 1027, and Zeitschr. anorg. Chemie, 1906, p. 657. 

Donath and H. Ditz, Oesterr. Zeitschr. Berg. n. Huttenw., vol. 51, p. 310, 1903. Donath 

and F. Braunlich, Chem. Zeitung, 1904, pp. 180, 953.
COAL. 653

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.

Ill 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 fueltesting plant of the United States Geological Survey. They are 

selected in order to show something of the recognized variations.*

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. Vlgo County, Indiana. Idem, p. 109.

D. Altoona, Iowa. Prof. Paper No. 48,

D. 223.

E. Shawnee, Ohio. Bull. No. 290, p. 14.5.- 

F. Staunton, Illinois. Idem, p. 68.

Ash......................................

A.

3.51

16.82

73.04

6.63

100.00 

.94

B.

2.61

34.92

56.30

6.17

100.00 

1.26

C.

9.55

36. 19

43.65

10.61

100.00 

3.72

D.

4.52

40.96

38.99

15.53

100.00 

6..S3

E.

9.90

33. 66

4486

11.58

100.00 

1.81

F.

13.72

36.24

39.72

10. 32

100.00 

3.96

With one exception the volatilizable part of these coals is less in 

amount than the fixed carbon. With the lignites the reverse state0 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.
654 THE DATA OF GEOCHEMISTRY.

merit 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 a 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 

and 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 Frits mine.

C.. .......................................

H.... .....................................

N... ......................................

O. ........................................

85.33

5.20

1 4Q

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 CM

1.18

H 'U

100.00-

80.69

4.94

1 9Q

13.08

100. 00

83.81

4 OS

1.47

9 74

100.00

Other variations, due to the peculiar character of certain coaly 

material, are illustrated by the following analyses':

Analyses of fossil plants and cannel coal.

A. Average of six analyses of fossil plants, from the coal beds of Commentry, France, 

by S. Meunier, in Fremy'e 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, Psaronim, 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, p. 320, 1840.

C. Analysis of Tyneside cannel, by H. Taylor, Edinburgh New Phil. Jour., vol. 50, p. 

145, 1851. 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

x, 77

8.44

100. 00

C.

87.89

6.53

2 no

3.50

100. 00

The suggestive feature of the foregoing trio is in the proportion of 

nitrogen. The fossil plants contain very little nitrogen; the cannels

a Zeitschr. angew. Chemie, p. 605, 1894. See also his Chemische Technologic der 

Brennstoffe, vol. 1, pp. 518-520.
COAJL. 655

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" 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 Avhen otherwise specified.

Average analyses of bituminous coal.

A. Average of twenty 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 forty analyses of bituminous coals from Ohio, Indiana, Illinois, Iowa, 

and Missouri. Also from the above-named reports.

C. Average of fifteen analyses of Scotch coals, by W. D. Anderson and ,T. Roberts, Jour. 

Soc. Chem. Ind., vol. 17, p. 1013, 1898. Sulphur is included in the figure for oxygen.

D. Average of eighteen coals from Newcastle, twenty-eight from Lancashire, and seven 

from Derbyshire, England. Recalculated from averages cited by Fischer, in Chemische 

Technologic der Brennstoffie, 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 

graphite. The technical analyses of anthracite show a large pro-

« Am. .Tour. Sci., 2d ser., vol. 23, p. 212, 1854. 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. 138) regards cannel as formed from the spores of 

cryptogams. No algae are found in it, or very few. 
656 THE DATA OF. GEOCHEMISTRY.

portion 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-testing plant, Prof. 

Paper U. S. Geol. Survey No. 48, p. 202, 1906.

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.0 .

Volatile .............................................

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

P.

2.98

 3.38

87.13

.66

5.85

100.00

E.

1.82

6.18

86.75

.75

4.50

100. 00

a See also C. A. Ashburner, Trans. Am. Inst. Min. Eng., vol. 14, p. 706, 1875-76, 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, p. 257, 1907.

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, p. 324, 1848.

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, p. 204, 1845.

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 chemischtechnischer Vortriige, vol. 9, p. 339. A valuable table of coal analyses is there given.

G. Average of sixteen. analyses of anthracite, compiled from various sources.

C.... ...........................

H.. ............................

N.... .....:....................

0.. ............................

A.

91.47

4.25

1.64

2.64.

100.00

B.

92.73

3.37

.85

3.05

100. 00

C.

93.90

3.22

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

.35

1.58

100. 00

G.

93.50

2.81

.97

2.72

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, arid which approach still more closely to pure carbon. 

The following substances belong in this class, with the possible exception of the first example. The crude analyses are given first.
COAL. 657

Analyses of anthraxolite, schungite, and graphitoid.

A. Anthraxolite, near Kingston, Canada. Analysis by W. H. Ellls, Chem. News, vol. 

76, p. 186, 1897. Found In Lower Silurian limestone.

B. Anthraxolite, near Sudbury, Canada. Analysis by Ellis, loc. cit. Found In the 

Cambrian."

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. Graphltoid, from the mica schist and phyllite of the Erzgebirge. Analysis by 

A. Sauer, Zeitschr. Deutsch. geol. Gesell., vol. 37, p. 441, 1885.

c..... .........................................................

H... ..........................................................

N. .............................................................

S...... ........................................................

0. .............................................................

HaO...........................................................

Ash...........................................................

A.

90.25

4.16

.52

66

3.69

.72

100. 00

B.

94.92

.52

1.04

.31

1 (\Q

1.52

100.00

' C.

98.11

.43

.43

1.09

100.06

D.

24.855

.06

1.01

73.854

99. 779

n Bills giA'es partial analyses of anthraxolites from three other localities. See also 

A. P. Coleman, Sixth Ann. Rept. Ontario Bur. Mines, 1897.

Rejecting ash, Avater, 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.

99.12

.44

.44

100. 00

D.

99. 76

.24

100.00

These minerals, and many anthracites also, might be properly 

termed metamorphic coals. Thej7 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,a CnH^Or,. 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.

« See B. C. Brodie, Liebig's Annalen, vol. 114, p. 6, 1860. 

14399 Bull. 330 08 42
658 THE DATA OF GEOCHEMISTEY. 

THE VARIATIONS OF COAL.

For comparison of all tHe fuels, starting with wood and ending 

with anthracite, the subjoined table has been compiled from the 

data given in the preceding pages. In the case of wood the figure 

for nitrogen is the mean of the determinations by Chevandier, 

Gottlieb, and Hawes.

Average composition of fuels.

Wood..................................................................

Peat. . .................................................................

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

o.-

43.20

35.56

20.50

8.69

2.72 I

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. . .................................................................

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

0.

87.0

64.1

28.1 in ^

9 Q

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, C6H1000 , these two elements 

exists 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 

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
COAL. 659

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." 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 sucli^ as phenol. In 20 analyses of 

coal gas, P. F. Frankland 6 found the following range of variations 

in the percentages of the principal constituents:

Variations in composition of coal. (jus. 

CO, _____-__-_____-_____.__:__-_____ __ __ Oto 2.73

- o,---. ------_:__.__ -___________ oto 1.00

( N3 __- __ -___ ___^__________-_ 2. 07 to 10. 84

- Hs-..__._____._____.__._____.__________._.__ 33. 24 to 53. 79

CO--________--_____-________1________. 2. 46 to 7.14

CH4 __1_______________-___.___-______-_. 36. 55to42. 93

The other products of distillation, obviously, must have been 

V- 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. 0

On account of this distinction between the combustible and noncombustible portions., of the distillates from coal, S. W. Parr d has 

proposed a technical classification of these fuels which differs essen-

-^ tially from the system above mentioned. His scheme is based upon 

the ratio between the total carbon and the carbon of the volatile 

matter, which latter is largely but not wholly combustible. He also 

takes into account the percentage of " inert volatile " matter, which

0 See, for example, P. Frazer, Trans. Am. Inst. Min. Eng., vol. G, p. 430, 1877-78, and 

C. A. Ashburner, idem, vol. 14, p. 700, 1885-80. 

W ".Tour. Soc. Chem. Ind., vol. 3, p. 273, 1884.

c A good article on the distillation of wood is in Watts's Diet, of Applied Chem., vol. 

3, p. 1026, 1893. The subject can not"be discussed at length here. 

'' Bull. No. 3, Illinois Geol. Survey, 1906. Also Jour. Am. Chem. Soc., vol. 28, p. 1425, 

1906.
660 THE DATA OF GEOCHEMISTRY.

seems to vary in a manner characteristic of the different groups of 

coals. M. R. Campbell,0 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. 6 In a single analysis of gas extracted from peat he 

obtained the following percentages:

C02 ____ __-_________________________________ 2.97

CH4 _____________________________________ 43. 30

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," 

who obtained his material by heating lignite in vacuo.to 50°, 100°, 

and 200°, successively, they consist principally of carbon dioxide, with 

subordinate carbon monoxide and nitrogen, and insignificant proportions of oxygen and hydrocarbons. The following examples are sufficient to show the general nature of his analyses:

a Prof. Paper U. S. Geol. Survey No. 48, pp. 156-173, 1906. See also P. Prazer, Bull. 

Am. Inst. Min. Eng., March, 1906.

"Jour, prakt. Chemie, vol. 92, p. 76, 1864.

c Jour. Chem. Soc., vol. 32, p. 146, 1877. See also Zitowitsch, Jour, prakt. Chemie, 2d 

ser., vol. 6, p. 79, 1873, on gases from Bohemian lignites.
COAL. 661

Analyses of gases from ^ignite.

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!

K Gas evolved from sample D on heating to. 200°.

CO,.. ...............................................

CO..................................................

f

Olefincs .............................................

CiHi. ...............................................

Oi..... ..............................................

Nil...................................................

A ."

96. 41

1.20

.32

2.17

100. 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 'W

2.08

KO

.34

100. 00

o 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 a 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 cnnnel. 350.6 cubic centimeters gas.

C. Scotch cannel, Wilsontown. 16.8 .cubic centimeters gas.

D. Scotch cannel, Lesmahago. 55.7 cubic centimeters gas.

K. Cannel shale, Lasswade, near Edinburgh. 55.7 cubic centimeters gas.

F. Whitby jet. 30.2 cubic centimeters gas.

-

COs.. ....................................

CH<.... ..................................

C2He ..... .................. ...............

C3H8 ............................... .......

^t......... ..............................

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

1 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

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.

"Jour. Chern. Soc., vol. 30,' p. 144, 1876.
662 THE DATA OF GEOCHEMISTRY.

The gases occluded by bituminous coal have been studied by several 

chemists. E. von Meyer a 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 & and W. McConnell.0 

For Welsh coals there are data by J. W. Thomas.** 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. 555.5 cubic centimeters gas.

COs.. ..........................

CH<. ...........................

0,... ...........................

N,.... .........................

A.

36.42

.80

62.78

100.00

B.

9.43

31.98

2.25

50.34

100.00

C.

5.44

63.76

1.05

29.75

100.00

D.

is on

67.47

1.02

12.61

100.00

E.

5 04

87.30

.33

7 31

100.00

F.

14 79

84.18

1.10

100.00

G.

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 

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 dioxide

"Jour, prakt. Chemie, 2d ser., vol. 5, pp. 144, 407, 1872; vol. 6, p. 389, 1873. 

reproduced in Percy's Metallurgy, vol. 1, p. 283, 1875.

6 Trans. North of England Inst. Min. Mech. Eng., vol. 37, p. 245. 

"Jour. Soc. Chem. Ind., vol. 13, p. 25, 1894. 

r. Chem. Soc., vol. 28, p. 793, 1876.

Data
COAL. .663

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.a 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 b 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,6 working with pressures of 2,000 to 6,000 kilograms to the 

square centimeter, found that peat and also the " ulmic acid" 

from the paper coals of Russia were merely compacted without 

change of chemical character. They retained their solubility in 

ammonia and showed no evidence of a true transformation into coal. 

Some experiments by Giimbel,d 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,6 who has studied this process with great care, found 

that when wood was heated nearly to 400° in a sealed tube, 78.5 per 

cent of it remained as a solid residue which had all the appearance 

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

0 See G. Biscbof, Edinburgh New Phil. Jour., vol. 29, p. 309; vol. 30, p. 127, 1840. T. 

Graham, Mem. Chem. Soc., vol. 3, p. 7, 1845. Lyon Playfair, Mem. Geol. Survey Great 

Britain, vol. 1, p. 460, 1846. A recent paper on the gases in coal is by F. G. Trobridge, 

Jour. Soc. Chem. Ind., vol. 25, p. 1129, 1906.

"Bull. Acad. Belg., vol. 49, p. 367, 1880.

c Bull. Soc. geol., 3d ser., Vol. 12, p. 680, 1884.

* Sitzungsb. Math. phys. Classe, K. bayer. Akad. Wlss., Miinchen, vol. 13, p. 141, 1883.

» Ann. chim. phys., 3d ser., vol. 32, p. 304, 1851.
664 THE DATA OF GEOCHEMISTRY.

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 Avith 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 a 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 l 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.

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

is o<;

is 9fi

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. c 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:

"Compt. Rend., vol. 32, p. 295, 1851. 

"Idem, vol. 88, p. 1048, 1879.

0 Cftem. Centralbl., 1901, pt. 2, p. 950. From a Hungarian original which I have not 

seen.
COAL. 665

Experiments to obtain coaly products from wood.

Temperature.

245

250

255

265

275

280

290

Time of 

heating.

Hours.

9

6

6

0

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, operating for a long time, may produce results resembling those whiclj 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

a Zeitschr. angew. Chemie, p. 821, 1902.
666 THE DATA OF GEOCHEMISTEY.

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. Hofmann's suggestions 

are interesting, but, so far as the formation of coal is concerned, the 

evidence in their favor is very incomplete.

How far micro-organisms are active in the formation of coal is 

doubtful. They abound in the stagnant waters of swamps,, and 

certainly have much to do with the earlier stages of vegetable decay. 

They start the process, but at the same time they generate antiseptic 

compounds which limit their activity. Peat, not far below the surface, is distinctly antiseptic and inimical to microbian life. Never 

theless, a number of authorities have argued strongly in favor of 

these organisms as principal agents in anthragenesis. B. Renault" 

has found their remains in lignite and coal in significant abundance 

and variety.

THE CONSTITUTION OF COAL.

In the preceding pages, under other captions, I have cited a good

deal of evidence relative to the substances found in coal or from

. which coal has been derived. Its vegetable origin is clear and needs

no further discussion now; its present constitution is more difficult

to determine.

The question of constitution presents itself under two' aspects, the 

one structural the other chemical. On the one side microscopic evidence is available, and it is seen that coal contains vegetable remains, 

micro-organisms, resinoid bodies, and so on. In some coals spores or 

spore cells are abundant; l in others, as shown by Renault, remains of 

algae are found. The lignites are obviously derived from woody fiber, 

and, in short, in many cases the proximate origin of the coals is not 

difficult to determine. Their structure, microscopic or macroscopic, 

tells a pretty clear story.

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 in-

"Bull. Soc. ind. rain., 3d ser., vol. 13, p. 865, 1899; vol. 14, p. 1, 1900. See also'L. 

Lemiere, idem, 4th ser., vol. 4, pp. 851, 1248, 1905, and vol. 6, p. 273, 190G. Also in 

Compt. Rend. VIII Cong. ge"ol. internat., p. .502, 1900. Lemiere regards the soluble or 

diastatic ferments, derived from living vegetation, as also operative in the process of 

vegetable decay.

6 See J. W. Dawson, Am. Jour. Sci., 3d ser., vol 1, p. 256, 1871. B. Orton (idem, vol. 

24, p. 171, 1882) 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 Pischer and Rust, Zeitschr. Kryst. Miu., vol. 

7, p. 209, 1882. The important memoirs by Bertrand and Renault have already been 

referred to.
COAL. 667

vestigations are difficult, the methods are not well formulated, and 

the available data are scattered and fragmentary. To what extent 

free carbon exists in coals is still an open question. It is probably 

absent from lignite and abundant in the extreme anthracites; but its 

quantitative determination can not be effected by any known analyti- 

£al process.

There are two distinct lines of attack upon the problem in question. First, by means of solvents, to extract certain constituents of 

coal and to identify them. Some of these constituents, which are 

commonly small in amount, can be dissolved by gasoline, ether, benzene, chloroform, alcohol, and other organic solvents. The extractive 

matter thus obtained is, unfortunately, not simple, but seems to contain a mixture of substances whose nature is yet to be determined. 

By handling large quantities of material these bodies may be obtained 

in sufficient abundance for more complete investigation, and their 

separation into definite fractions is by no means hopeless."

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 algse, the problem becomes more complex. The chemical 

constitution of those forms of vegetation is still very obscure. Up 

to the present time the mistake has been made, by chemists engaged 

in the study of coal, of assuming that the celluloses are the chief 

starting points an assumption which is not unqualifiedly true. Carbons of animal origin also require attention. Much preliminary work 

of this kind remains to be done.

The direct separation of its constituents from coal is, however, 

possible only to a very limited' extent. Hence the second line of 

attack, the conversion of these bodies into recognizable derivatives, 

is also essential. Not only do we need more experiments along .the 

line developed by Donath, whose distinction between the lignites and 

the true coals has already been discussed, but much more needs to be 

done in the study of oxidation products, chlorine derivatives, etc. 

For example, in addition to the researches upon the nitrocompounds 

derivable from coal and the chlorination experiments reported to the

0 Qn this subject see the authorities already cited. Also P. Slepmann, Preuss. Zeitschr. 

Berg-, Hiitten-, u. Sal.-Wesen, vol. :-!9, p. 27, 1891. F. Muck (Die Chemie der Steinkohle, 

Leipzig, 1891) gives a good summary of earlier investigations by DondorfC, Reinsch, etc. 

An interesting memoir by W. C. Anderson (Proc. Phil. Soc. Glasgow, vol. 29, p. 72, 1897) 

also describes a number of important experiments.
668 THE DATA OP GEOCHEMISTEY.

British Association, there are investigations like that conducted by 

L. Schinnerer and T. Morawsky.0 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.

» Ber. Deutsch. chem. Gesell., vol. 5, p. 185, 1872.
INDEX.

A. Page.

Aar, River, analysis of water__ _- 77

Abbot, H. L. See Humphreys and

Abbott.

Abert Lake, analysis of water__ 125, 136 

Abich, H., analyses of spinel__ __ 280 

Abilena well, analysis__________ 146 

Abilene artesian well, analysis _ 141 

Absorption, of substances by soils- 424-420 

Acanthite _______________ 560 

Acetylene ________________ 629 

Acetylene series_________ _ 622 

Acheson, B. G., artificial graphite__ 266 

d'Achiardi, A., origin of borates__ 198 

d'Achiardi, G., minerals in marble _ 537, 539 

origin of borates __ _ __ 198 

Ackroyd, W., atmospheric transport

of salt_________ 48, 130

relative abundance of elements. 26

Acmite ________________ 314-316

Actinolite _______________ 318-319

Actinolite-magnetite schist______ 526

Adamellose ____.__________ 382

Adamite ______________ __ 580

Adams, B. F., cited__________ 42

Adams, F. D., allanite and epidote__ 341

analyses by_____ __ _ 71, 144

raelilite rocks____________ 334

monmouthite ___________ 376

Adams, F. D., and Harrington, B. J.,

hastingsite ______ 322 

Adams, F. D., and Lawson, A. C.,

scapolite diorite__ 338, 515 

Adams, G. I., concentration of petroleum ______ 640 

gypsum _ 185 

native sulphur_____ 495 

zinc deposits_____________ 583 

Adtcr. River, analysis of water _ 77 

Adobe soil________________ 432-434 

Adriatic Sea_________________ 94 

Adschi-Darja. Sec Karaboghaz. 

Aegirite ________________ 314-316 

Aenigmatite _______________ 323 

Agate ____ __________- 294 

Aguilarite __________________ 562 

Aguilera, ,T. G., stibbnite_______ 597 

Aiguer. A., polyhalite _________ 181 

Aikenite__________________ 569, 570 

Air, dissolved, composition of____ 402 

See also Atmosphere.

Page..

Aisinmann, ,origin of petroleum- 634 

Aitken, J., atmospheric dust____ 48 

Akermannlte ____________ 333, 334 

Akerose ______ 370, 371, 374, 3'83, 884 

Alaskose ____________ 366, 367, 368

Albanose _ ___________ 376 

Albert, R. See Malkomesius and

Albert.

Albertite ___: _________ 624, 625 

Albite _________________ 300-304 

Albite mosaic______________ 512 

Alexandrolite _____________ 604 

Alexejeff, W., dopplerite ______:_ 647 

Alferric minerals__________ 358, 359 

Algfc, as limestone makers__ 471, 472, 470 

as 'source of bitumens_____ 637, 638 

magnesium carbonate in____ 485 

Algfe, siliceous_____________ 439 

Algodonite ______________ 567

Alipite____________________ 603

Alkali, in soils____________ 189-.195

Allanite __________ 340-342, 617, 618

Allemontite _______________ 595

Alien, E. T., aluminum hydroxide _ 422

analyses by_____________ 185

native iron____________ 270

synthesis of diopside_______ 314

of quartz____________ 296

See also Day and Alien.

Alien, E. T., and White, W. P.,

fusion of lime silicate- 240 

wollastonite __________ 313, 537 

Alien, E. T., Wright, F. E., and 

Clement, .T. K., magnesium silicate_____ 239, 

240, 312, 320,325

Alien, 0. D., analyses by_______ 119,

.123, 159, 188, 189, 190, 191

Alloclasite _______________ 599

Allopalladium ____^________ 607 

Allophane ___ _ __________ 527 

Alma well, analysis cited______. 144 

Almandite _____________ 334-337 

Aloisi, P.. spinel .rocks________ 281 

Altai, Lake, analysis of water__ 131, .135 

saline deposit___________ 187 

Altaite ________________ 584 

Aluminum, distribution ________ 13 

in sea water-__________ 92

Alum shale________________ 467 

Alums ___-__________ 211,22]

669
670 INDEX.

Page. 

Alunite ____________ ___ 211

Alunogen ___________ ___ 211 

Alway, F. J., and Gortner, R. A.,

water analysis____ 126 

Amalgam ________ __ _ 555 

Amazon River, analyses of water__ 73, 83 

Amber 644 

Amblygonite __________ _____ 593. 

Amesite __________________ 331 

Ammiolite ________________ 573 

Ammonia, in rainfall _ ______ 40 

in sea water____________ 91, 92 

Amphiboles ______________ 318-323 

Amphibolite _____________ 508-510 

Analcite _____________ 304-306, 316 

Analcite rocks_______ 306, 307, 378, 379 

Anamorphism, zone of_________ 502 

Anatase ________________ 288-290 

Andalusite_________ 343-344, 527, 528 

Andalusite rock* ____________ 530 

Anderlini, F. See Nasini, R. 

Anderson, , cited_________ 129 

Anderson, W., cited________ 124,156 

Anderson, W. C., experiments on coal_ 667 

Anderson, W. C., and Roberts, J.,

coal __________ 652, 655 

Anderson, W. S., solubility of calcium carbonate____ 98 

Andesine ________________ 300 

Andesite ___________' ____ 383,412 

Andorite _______________ 562, 585 

Andose ____ 380, 383, 384, 385, '388, 389 

Andouard, A., phosphate rock___ 445 

Andradite ______________ 335-337 

Andrew, A. R., phosphate rock___ 451 

Andrews, T., native iron________ 267 

Androscoggin River, analysis of water _____________ 62 

Androussof, N., reduction of sulphates by bacteria.. 116, 438 

Anger, F. A., shale__________ 469 

Anglesite ______________ 587,588 

Anhydrite ___ 178, 180, 181, 182, 183, 199 

Animikite ________________ 560 

Ankerite ________________ 484, 490 

Annabergite _______________ 602 

Anorthite ____________ 300-304; 538 

Anorthoclase _____________ 300-304 

Anorthosite _______________ 390 

Ansdell, G. See Dewar and Ansdell. 

Ansel, H., iron ores_________ 494 

Anthophyllite ______________ 318, 319 

Anthracite ______________ 655-658 

Anthraxolite ______________ 657 

Antimony, distribution________ 13 

ores of-,._____________ 595-598 

Ants, geological work of______ 410 

d'Aoust, V., oolite____ _______ 471 

Apatite__________'__ 292, 293, 442-451 

Aphrosiderite ______________ 331 

Aphthitalite _______________ 178 

Aplite___________________ 366 

Apophyllite _____________ 265, 350 

Aragonite_____________ 351, 473-475 

Aral, Sea of, analysis of water. _ - _ 128, 135 

Arctic Ocean, analyses of water__ 95

Page.

Arctowski, H., synthesis of hematite- 285 

Ardennite ________________ 613 

Arfvedsonite_____________ 322, 323 

Argall, P., distribution of nickel _____ .598

Argentina, rivers of _ _ _ _ ________ 74

Argentite _ _ _ _ ________ _ 560

Argon, distribution.__________ 14,38 '

in spring waters _ _ _ __ __ .140

Argyrodite _ _ _ _______ 562

Arias, Rio de, analysis of water _____ 74

Arkansas Hot Springs, analysis of

water ______ _ 152

Arkansas River, analysis of water__ 59, 69

flow of________________ 68 

Arkansose ________________ 376 £ 

A;:kite___________________ 37G '

Aromatic hydrocarbons-________ 623

Arrhenius, S. A., carbon dioxide and

climate_____ _ 44

nature of earth's interior ___ 52

volcanic explosions-___ ___ 232, 233 

Arsandaux, , analysis by____ 445 

Arsenic, distribution_________ 14

in sea water-______..___ 92

ores of __________ __ 595-598

Arsenolite ___________________ 598

Arsenopyrite _ _ _ _ _______ 595, 596, 597

Arva-Polhora, analysis of water__ 143 

Arve River, analysis of water 76 

Arzruni, A., cassiterite as a furnace

product ________ 291, 591

cuprite----:_______-____ 571

hematite _____________ 285 

Asbestos____ ______________ 318

Asbolite__________________ 456,602 

Aschan, O., iron ores_____ ____ 453

waters of Finland--___ _ 83 

Ascharite_________________ 180,202 }- 

Ashburner, C. A., anthracite-____ 656

classification of coals___ _ 659 

Ashley, G. H., antimony deposits_ 597

formation of peat_______ 645, 648

See also Blatchley and Ashley. 

Askwith, W. R., antimony mines__ f>97 _^ 

Aspasiolite 1______________ 340 

Asphalt__-_______________ 624-627 

Assiniboine River, analysis of water- 71 

Aston, E., analysis by____ __ 522 

Astrakanite- _ _ _ ____________ 178'

Atacamite _ _ _ _ ____________ ri71

Atherton, T. W. T., gold sulphide__ .j54 

Atlantic Ocean, analyses of water_ 95 

Atlin, spring near, analysis __ . 149 

Atmosphere, composition of_____ 38 44 ~'

mass of________________ 22. 49

the primitive___________ 49-52 

Atopite __________________ 598 

Atterberg, A., alteration of topaz_ 342 

Attwood, G., decomposition of diabase ___________ 413 

Aubin, E., cited____________ 39 

Audoynaud, A., ammonia in sea- . i

water___________ 92 

Auerbach, F., cited__________ 159 

Auge", , bauxite_l________ 419, 420 

Augite __________________ 316-318
INDEX. 671

Page.

Angite, melting point_________ 240 

Austin, W. L., nickel ores______ 602 

Autunite _________________ 613 

Auvergnose ________ 384, 385, 388, 389 

Avalite ________'_,________ 604 

Awai-uite _______________ 269, 270 

Azohnmic acid________ ___ 409, 646 

Azurite ___________________ 572

Babingtonite ______________ 317

Biickstrb'in, H., fusion of micas__ 330, 376

on Soret's principle_______ 255

, synthesis of acmite___ _ 315

i Bacon, R. F., analyses cited____ 156

Bacteria as agents in rock decompos sition__________ 409,410 

Bad Elster, analysis of water from_ 151 

Baddeckite ______________ 326 

Baddeleyite ______________ 617

Baer, W., analyses of wood____ _ 643 

Baerwald, C., .pseudomorphs of

chrysocolla _____ 571

Baeumler, , nickel in shale 598 

Baikal, Lake, analysis of water___ 81 

Bailey, E. H. S., analyses by__ 146, 621 

gypsum ___ ___ ___ 185 

Bailey, E. H. S., and Case, E. C.,

analyses by ____ 141, 184 

Bailey, E. H. S., andj Franklin,

E. C., water analyses. 67 

Bailey, E. H. S., and Porter, F. B.,

analysis by_______ 141

Bailey, G. E., California borates__ 198

soda niter_____________ 206

Bain, H. F., fluorite__________ 500

lead and zinc deposits. _ 583

Baker, A. L., bromine in bittern___ 186

synthesis of livingstouite.___ 575

Baker, H. B., cited__________ 45

Bakerite __________________ 200

Balatonsee, analysts of water-____ 80

Baldacci, L., sulphur deposits ___ 497

^ Balland, , cited_________ 59

Ballo, ^M., water analysis______ 79

Ballston waters, analyses _ 144, 145

Baltic sea, analysis of water 95

Baltiraoriase - 390

Baltimorose 390

Karnberger, E., fichtelitc_________ 64S

Bandose__________________ 382, 388

Bandrowsky, F. X., nitrogen in pe- 

,~» troleum _ 62-i 

Baragwanath, W., platinum = 611 

Barber, W. B. See Nutter and Barber.

Barbour, E. H., and Torrey, .T., siliceous oolite______ 466

Barcenite__________ __ 573, 597 

Barchatow bitter lake, analysis of

water _________ 132,135 

Baret, C. See Lacroix and Baret. 

Barite ___________ 106, 461, 498-500 

Barium, distribution_____ _ 14, 498

in sea water 92

Page.

Barkevikite ______________ 322, 323 

Barlow, A. E., nickel deposits__ 600, 602 

Barnard, H. E., analysis of water_ 62 

Barr, W. M., analysis cited ___ 155 

Barr, W. M., Spaulding, H. S., and 

Van Winkle, W., analyses of water_____ 64, 

66, 67, 68, 69

Barrandite ______________ 443, 446 

Barrels, C., chloritoid rocks____ 529 

Barschall, H. See Van't. Hoff and

Barschall.

Barns, C., sedimentation______ 429 

thermo-couple __________ 238, 239 

water glass___r 243, 244, 504, 551 

Barus, C., and Iddings, .T. P., electric 

conductivity of molten 

rocks __________ 245 

Barysilite ___________________ 590

Basalt _______________ 385-387

fusibility __________ 242, 245, 24.6

Basanite __________________ 373

Basch, E. E., syngenite and polyhalite ___________ .181

Basic rocks________________ 393

Baskerville, C., analyses by____ 281, 604

thorium ________________ 617

vanadium in peat _ _ _ 612 

See also Corse and Baskerville. 

Bassett, H., cited 119

Bastite _______ ______ 313

Baubigny, H., synthesis of sphalerite____________ 578 

Bauer, K., fusion of mineral mixtures ___________ .252 

Bauer, M., laterite___________ 418

nephelite in schists_ _ _ 308 

Bauerman, H., and Foster, C. Le

Neve, celestite_____ 498 

Bauraert, M., composition of dissolved air_______ 45,402 

Baur, E., synthesis of quartz; and

tridymite ______ 296, 303 

Bauxite ________ ______ 417-424

Bayldonite _________________ 590

Bayley, W. S., actinolite-rnagnetite

schist__________ 319

graywacke __ _ 462

iron ores____ _ _ _ 284

talcose schist_______ _ _ 538

Beam, W., water analyses 82

Bear River, analysis of water ___ 120

Beaumont, E. de, distribution of

the elements._ _ _ 13 

Beauvallet, P., vanadium in clay _ 612 

Be"champ, A., equilibrium in mineral

.waters _____ 159

hydrogen sulphide and calcium

carbonate ___ _ 496 

Bechl, E., origin of borates____ 197,198

distribution of vanadium____ 612

Bechilite _________________ 196

Beck, R., cassiterite in granite. _ 291

. native copper__ '. _ 566

native silver __ _ 559

nickel deposits 601
672 INDEX.

Page.

Beck, R., ore deposits 541, 548 

primary gold _ __ 271 

tin ores_______________ 593

Beck, R., and Fircks, W. von, copper ores __ 568 

stibnite _______________ 597

Becke, F., amphiboliteJ_______ 510 

changes of volume in metamorphism __________ 506 

eclogite ________ __ 517 

hornblende pseudomorphs _ 321, 326 

saussurite gabbro_ _ __ 513 

scapolite rock___________ 515 

See also Step and Becke.

Becker, A., fusion of hornblende__ 320 

fusion of limestone- __ 477

Becker, G. F., arsenic and antimony

in sinter_______ 596,597 

borates _______________ 196 

Borax Lake_____________ 124 

constitution of amphiboles and

pyroxenes __ __ 321 

epidote from chlorite_____ 515 

eutectic classification of rocks_ 355 

fractional crystallization in

magmas __ __ 257 

formation of native sulphur__ 495 

geological significance of wollastonite ________ 313 

glaucophane rocks_______ 323, 509 

gold in sinter___________ 556 

heavy metals in granite_____ 543 

magmatic differentiation ____ 255 

mercury ores____ 573, 575, 576, 577 

minerals in sandstone______ 462 

nature of magmatic solutions-_ 245 

serpentine ________ 348, 520, 521 

solvents of gold_________ 557 

Steamboat Springs ______ 145, 162 

waters of Sulphur Bank ____ 154

Becker, G. F., and Melville, W. I-I.,

mercury in sinter __ 577

Becquerel, A. C., synthesis of dioptase ___________ 572

syntheses of lead ores______ 585,

586, 587, 589

Becquerel, H., and Moissan, H., free

fluorine in fluorite__ 274

Bedson, P. P., barium in water___ 498 

gases in coal ___________ 662

Beegerite__ ___ ________ 586

Beemerose ____ __________ 374

Beerbachose______________ 384, 388

Beilstein, F., and Wiegand, E.,

ozokerite ________ 625

Beisk, Lake, analyses of water__ 131, 135 

saline deposits __ ____ 187

Beistle, C. P. See Frear and

Beistle__________ 431

Belcherose __ __________ 390

Bell, ,T. B., platiniferous quartz__ 610

Bell, J. M. See Cameron and Bell.

Bell, R., corrosion of limestone___ 479 

nickel deposits__________ 600

Bellucci, G., chlorides In rain____ 47

BSlohoubek, A., water analysis___ 77

Page. 

Bemmelen, J. M. van, absorbent

power of hydrogels__ 425 

absorption of potassium by

clays__: ____-____ 107 

aluminum hydroxides__ __ 422 

hydroxides of iron __ _ 453 

tropical soils ___________ 423 

zeolitic silicates in soil_____ 166 

Bemmelen, J. M. van, Hoitsema, C., 

and Klobbie, E. A., 

bog iron ore____ 4.52, 454 

Bemmelen, J. M. van, and Klobbie,

E. A., iron hydroxides- 453 

Benedicks, C., sericitic rocks____ 511 

Bennett, J. See Haworth and Ben- i

nett.

Benzene series________ _-__ 623 

Beraunite _ _ _ 443 

Beresovite _______________ _ 588 

Bergeat, A., boric acid from Vulcano_ 196 

occurrence of titanium minerals____________ 290 

ore deposits _ : 541 

 volcanic sublimates__ _ _ 221 

Bergenose __ _________ ____ 393 

Bergluud, E., 'bromine in sea water- 94 

Bergstrasser, ; , cited___ 128 

Bergt, , analysis by._ 466 

Bertels, G. A., origin of petroleum_ 635 

Berthelot, M., gases in native iron__ 234 

origin of petroleum_______, 631 

synthetic hydrocarbons _____ 629 

Berthier, , synthesis of olivine_ 324 

Berthierine ___ _ _ _ 494 

Berthierite ________________ 595 

Bertrand, C. E., and Renault, B.,

origin of bitumen___ 637 

Bertrandite _______________ 348 

Berwerth, F., constitution of hornblende _________ 321 

Beryl ____:____________ 347,348 

gases from__ ____ _ 225 

Beryllium. See Glucinum.

Beryllonite _____ _________ 348 ^ 

Bea'zelianite ______________ 567 i 

Berzelium _____________.!_ 617 

Best, A. See Coates and Best. 

Beudantite ________________ 590 

Beyer, S. W., clays 431 

Beyerinck, M. W., cited________ 87 

Beyrichite ________________ 599 

Beyschlag, F., cobalt ores__ ___ 598

See also Monke and Beyschlag. 

Bickell, C., analysis by________ 162 *"' 

Biddle, H. C., precipitation of copper________ __ 566 

Biddle, H. J., nickel ores_______ 602 

Bieberite ________________ 602 

'Biggs, J. W. H. See Clowes, F. 

Bigstone Lake, analysis of water._ 66 

Biljo Lake, analysis of water _ 131,137 

Binder, G. A., solubility of cinnabar_ 575 >_l 

Bindheimite ________________ 590 

Binney, E. W., and Talbot, J. H.,

petroleum in peat 637 

Biotite _________________ 327-331
INDEX. 673

Page.

Biquard, R. See Moureu, C.

Bird, M., analysis by_________ 141

Bischof, G., analyses by__ 79, SO, 132, 428

cements in sandstone_ ___ 460

dolomitization _________ 486

gases in coal____________ 663

loess ' : ___ 434

origin of salt beds________ 175

reduction of silver sulphide____ 559

solvents of gold_________ -557

sphalerite in sinter ___ 579

zinc carbonate _ ___ 581

Bischoflte _______________ 179, 180

Bismite __._______________ 598

Bismuth, distribution _.__ 14

ores of__________ _ 595-598

Bismuthinite ______________ 595, 596

Bismutite ________________ 598

Bismutosmaltite _________- 599

Bismutosphserite __________ 598

Bistineau ; hrine, analysis of____ 141 

Bitter Lake, analysis of water_ 131,135 

Bitterns_____________ 174, 185,186 

Bitumen________________ 624-627 

Bituminous coal____________ 653-655

Bizio, G.,"lithium in sea water___ 92 

Black Lake (California), analysis of

water-,._______ 124,136

Black Lake (Roumania) _______ 133

Black Sea, analysis of water_____ 95

Blackwell, G. G., bauxite______ 420

Blake, J. F., glaucophane schist___ 509

Blake, R. F., cited___________ 42

Blake, W. P., bauxite_________ 421

gilsonite and wurtzilite ___ 625

primary gold_____ ____ 553

Terlingua mines__________ 573

tin deposits ___ 594

tungsten ores___________ 607

zinc deposits_______, _____ 583, 584

Blanc, G. A., radioactivity _____ 260 

Blanckenhorn, M. See Semper and

. v Blanckenhorn. 

Biatchley, W. S., clays________ 431 

petroleum_____________ 639

Biatchley, W. S., and Ashley, G. PI.,

marl____ ___ 472

Bleicher, , iron ores __ 494 

Blende__________________ 578-584 

Bloedite________________ 178, 179 

Blue Lick Spring, analysis______ 142 

Blue River, analysis of water.___ 68 

Blum and Leddin, Carlsbad spriidelstein___________ 160

Bobierre, composition of rainfall-_ 48

Bobierrite ________________ 444

Bode, G., cited_____________ 60

Bodenbender, G., wolframite____ 607

Bodlander, G., analysis by_____ 492

melllite in Portland cement__ 333

sedimentation__ _ ____ 429

Biidtker, gytje______________ 438

Boeke, PI. E., sintering of calcium

carbonate _______ 478 

Bottcher,W. See Kniiner and Bb'ttcher.

14399 Bull. 330 OS 43

Page.

Boettker, E., Norwegian pyrite___ 273 

Boghead mineral____________ 637

Bog-iron ore_______ 409, 452-454, 490 

Boleite_________ _________ 588 

Bolley, P., origin of borates_____ 198 

Bolton, H. C., solubility of minerals

in organic acids 408, 409 

Bolton, W. von, tantalum- _ _ 617 

Boltonite________________ 325 

Boltwood, B. B., radioactivity of waters___________ 152 

Bone, W. A., and Jerdan, D. S., syn- .

thetic hydrocarbons__ 629 

Bonneville, Lake __________ 118-121 

Bonney, G. T., glancophanc eclogite ___________ 509 

matrix of diamond _______ 265

serpentine _____________ 519

Boracite ________________ 180, 202 

Borates ____________ .1.80,195-205 

Borax ______ 106, 108, 100, 200, 201, 202 

Borax Lake, analysis of \vater___ 124,136 

borax from_____________ 196

Bordas, F. Sec Girnrd, C. 

Borgstrb'm, L. II., hackmannite__ _ 309 

Boric acid________________ 196 

Borickite __1_____________ 443 

Borne, G. von dem, radioactivity of . granite_________ 260 

Bornite ___________ 273, 567, 568, 569 

Borntriiger, H., analyses of peat___ 647 

Borocalcite _____________ - 196 

Borodowsky, W., orpiment and realgar____________ 596 

Boron, distribution______ 14

in sea water______ 92

nitride ________________ 197

sulphide ______________ 198

Boronatrocalcite _.._______ 201'

Bothamley, C. IT., analysis by_ 143

Boudonard, 0., melting point of

silica__________ 240 

Boulangerite____________ 585, 586 

Bouquet, .T., analyses by _ 149, 161 

spring deposits_____ __ 160, 161 

Bouquet de la Grye, A., cited____ 96 

Bourcart, E., Swiss lakes__ _ 76 

Bourgeois, L., cassiterite in scoria__ 591 

formation of perofskite __ _ 287 

fusion of garnet _ 335 

synthesis of crocoite .. : 589 

of hydrocerussite__ _ 587 

of iolite____________ 339 

of meionite_______^___ 338 

of melilite and gehlenite_- 334 

of smithsonite _______ 581 

of spessartite________ 335 

. of titanite__________ 288 

Bourgeois, L., and Traube, PL, synthesis of dolomite __ 483 

Bourgoin and Chastaing, analysis by_ .154 

Bournonite _._______________ 569 

Boussingault, J. B., analyses by_ 156, 186 

carbon dioxide from volcanoes_ 42 

Dead Sea______________ 129 

jet ___'______________ 649
674 INDEX.

Page.

Boussingault, J. B., manganese nodules ._________'.____ 193 

nitrate earth____________ 205 

origin of acid in volcanic waters 157 

Boussingaultite _ _______ 196 

Boutwell, J. M., carnotite_______ 615 

Bownocker, J. A., petroleum_____ 639 

Bow River, analysis of water____ 72 

Brackebuschite ___________ 590 

Brackett, R. N., analyses by__ 68, 412, 466 

Brackett, R. N., and Williams, J. F.,

rectorite ________ 527 

Braconnier, , analysis by____ 146 

Bradley, F. H., unakite________ 516 

Braunlich, F. See Donath and

Briiunlich. 

Bragard. See Fernandez and Bragard.

Brand, A., artificial breithauptite__ 599 

Brandenbourg, R., water analysis_ 76 

Branner, J. C., antimony deposits_ 597 

bacterial decomposition of rocks 410 

bauxite _______________ 421 

clays ________________ 431 

flow of Arkansas River_____ 68 

geological work of ants_____ 410 

magnesia in coral reef_____ 487 

novaculite _____________ 464 

phosphorite._____-_____ 449 

sandstone reefs_^________ 460 

tallow clays___________ 583 

thermal disintegration of rocks_ ' 401 

zinc deposits ___ __ 583 

Branner, J. C., and Newsoni, J. F.,

phosphorite ______ 449

Brauner, B., gold telluride______ 556

synthesis of hessite_______ 562

. Brauns, R., alteration of olivine_ 326

conchite ______________ 473

gold in a cement_________ 556

origin of salite__,______ 314

theory of micas__________ 331

webskyite _____________ 348 

Bravo, J. J., vanadium ores_____ 613 

Brazier, J. S., analyses by____ 436, 437 

Brazos River, analyses of water__ 69 

Breese, C. M. See Failyer and Breese. 

Breitenlohner, J. J., on the Elbe__ 78 

Breithauptite ______________ 599 

Breunnerite __:_________^__ 351, 490 

Brewer, W. H., sedimentation____ 429 

Brewsterite _______________ 350 

Briegleb, H., synthesis of apatite__ 292 

Brines, natural____________ 141 

Brinsmade, R. B., cerussite deposit. 586 

Brochantlte _____________ 571, 572 

Brock, R.W., gold in igneous rocks_ 271, 553

platinum _____________ _ 611 

Brodie, B. C., graphitic acid_____ 657 

Brogger, W. C., alteration of acmite

to analcite ______ 316

alteration of analcite_____-__ 307 

of arfvedsonite and barkevikite___________ 323 

of elseolite__________ 309

classification of igneous rocks 358

Page. 

Brogger, W. C., composition of barkevikite __________ 322 

formula of aenigmatite_____ 323 

gibbsite and diaspore_______ 422 

magmatic differentiation __ 245, 254 

nepheline syenites______:_ 376 

nordenskioldine _________ 591 

occurrences of fluorite__-__ 274 

of zircon ____________ 292 

spreustein __ ____ 811 

sulphides in pegmatite_____ 273 

Brogger, W. C., and Biickstrom, II.,

the garnet group__ 309, 335 

Broggerite _ __ ____ 614 

Bromine, distribution _________ 14 

in bittern _____________ 186 

Bromly, A. H., tin deposits_____ 593 

Bromyrite __-_____________ 564 

Brongniardite_____________ 562, 585 

Bronze, minerals formed on_ 568, 571, 572 

Bronzite ___-______________ 811 

Brookite __-____________ 288-290 

Brooks, A. H., tin deposits___:__ 594 

Brooks, W. K., abundance of life in

ocean __________ 115

Brown, A. P., pyrite and marcasite_ 273

Brown, B. .E., water analyses___ 70, 102

Brown, C. R. See Judd and Brown.

Brown, L. See Meadows and Brown.

Brown, L. P., phosphorite______ 449

Browne, D. H., nickel deposits___ 600

Brucite __________________ 484, 538

Brugnatelli, L., titanollvine______ 324

Bruhns, W., synthesis of corundum- 275

synthesis of hematite__ 285

of ilmenite __________ 286

of quartz and tridymite__ 296

Brumell, H. P. H., petroleum____ 639

Brun, A., fusibility of basalt-____ 242

melting points of minerals__ 239,

240,241

synthesis of corundum _ _ 275 

of zoisite___________ 340 

volcanic gases_________ 231, 233 

Brunlechner, A., formation of iron

ores __________ 491 

Brunswick well, analysis_______ 142 

Brush, G. J., pyroxene in slag__ 314 

Brush, G. J. and Dana, E. S., alteration of spodumene__ 315 

eucryptite _____________:_ 309 

Brushite ________________ 444, 445 

Buchanan, J., section of nitrate deposit____________ 207 

Buchanan, J. Y., density of sea

water__________ 96

manganese nodules _______ 103

marine mud ___________ 438

oceanic carbonic acid______ 113

Buchrucker, L., babingtonite in slags_ 318

Bucking, H., occurrence of iolite. 339, 340

Buckley, E. R., clays_________ 431

Buckley, E. R., and Buehler, H. A.,

zinc deposits______ 583 

Buehler, H. A. See Buckley and 

Buebler.
INDEX. 675

Page. 

Bujor, P., cited..___________ 132

Biiliiktii-Kul, analysis .of water__ 132,135 

Bunsen, R. W., composition of dis-

. solved air_____ 45,402 

fundamental magmas _- ______ 254

gas analysis __________ 111

gases in rock salt ____ _ 224

oxygen of the atmosphere__.._ 39 

volcanic gases __________ 213

Bunsenite __:________ _____ 602 

Burchard, E. F., lignite_______ C51 

Burton, C. V., artificial diamond__ 264 

Bush, B. R., nickel deposits_____ 601 

Busz, K., analyses by_________ 418 

corundum _. .. ________ 276 

Buttgenbach, G., Argentine borates_ 202 

Byasson, I-J., origin of petroleum- 631 

Byerlite __ ______________ 627

Byerly, J. H. See Mabery and Byerly.

Bygddn, A. eutectics_________ 249, 356 

Byske-elf, analysis of water_____ 81 

Bytownite _______________ 300

Caballero, G. de .T., cobalt in Mexico- 598 

ramirite _______________ 613 

Cabrerite ________________ 602 

Cache la Poudre River, analyses of

water.__________ 58 

Cacoxenlte _______________ 443 

Cadell, H. M., cited, on Stassfurt

salts_________ 176 

Cadmium, distribution_________ 14 

ores of ____________ 577-:579 

Cady, H. P., and McFarland, D. F.,

helium in natural gas_ 621 

Caesium, distribution_____ 14 

in sea water____________ 92 

Cagniard-Latour, artificial coal__ 664 

Cahaba River, analysis of water___ 63 

Calamine _ _____________ 580,583 

Calaverite 555 

Calb, G. Sec Jannasch and Calb. 

Calcareous sinter_______; 159, 160, 471 

Calcioferrite _______________ 443 

Calciovolborthite ____________ 612 

Calcite ______________ 351, 473-475

enclosing sand_ ___ ___ 459

Calcium, distribution _________ 14

Calcium carbonate, circulation of_ 100

proportions on ocean floor.__ 101

solubility of____________ 98,99

Calculation of rock analyses 397-399

Calderon, C. S., Chaves, D. F., and

Pulgar, P. del,- glauconite ___________ 440

Caledonite _________________ 588

Caliche ________________ 206,207 

California geysers _ _ _____ 156 

Californite ________________ 337 

Calker, F. J. P. van, pseudogaylussite ___________ 123 

Callalnite ________________ 443 

Calomel ____ __________ . 573

Page.

Cameron, F. K., water analyses_ _ 70, 120 

Cameron, F. K., and Bell, .T. M.,

solubilities ____.__ 183 

Cameron, F. K., and Hurst, L. F., 

solubility of calcium 

phosphate _______ 442, 443 

Cameron, F. K., and Seidell, A., solubility of ' calcium 

phosphate _____ 442, 443 

Campbell, H. D. See Howe, J. L. 

Campbell, M. R., borate deposits__ 198,

199, 200, 201

classification of coals______ 660 

Campbell, W., and Knight, C. W.,

. cobalt ores ______ 602

nickel deposits__________ C01 

Campbell, W. D., pseudomorph of 

gold _______ 557 

Camptonite _____________ 384 

Camptonose ________ 384, 385, 388, 389 

Canadase _____________'__ 389

Cancrinite ______________ 309-311 

Canfieldite __:_____________ 562 

Cannel coal ___________ 654, 655, 661 

Caracolite _______________ 587 

Carbides, metallic___________ 230 

Carbon, distribution __________ 15 

Carbon dioxide in the atmosphere_ 41-44 

Carbonates in sea water____ 98, 99,100 

Carbonates, alkaline ________ 189-195

origin of_____________ 165, 166 

Carbonic acid, oceanic____ 112,115, 116 

Carbonyls, metallic_____.____ 269 

Carborundum ______________ 266 

Canles, P., barium and sulphates in

natural water_____ 160

fluorine in shells of mollusks_ 91 

in spring waters_______ 149 

Carlsbad Sprudel water, analysis__ 151 

Carminite ________________ 590 

Carnallite ____________ 179, 180, 181 

Carnelley, T., on periodic law*___ 35

solubility of copper________ 565 

Carnot, A., fluorine in phosphates- 446, 447

fluorine in sea water_____ 91

niinervite____________ _ 445

phosphate rock_________ 442

syntheses of stibnite and bis-

' muthinite ________ 596

water analysis__________ 132

Carnotite______- ___________ 615, 616

Carolinium ________________ 617 

Caron, H. See Deville and Caron. 

Carpenter, W. L., oceanic carbonic

acid _________.. 116, 475 

Carrollite________________ 567, 599 

Carstone _______________ 463

Caryinite ____:____________ 590 

Casares, J., fluorine in spring water. 149 

Case, E. C. See Bailey and Case. 

Case, W. H., zinc deposits______ 583 

Casoria, E., palmerite________ 445

volcanic sublimates_______ 221 

Caspian Sea__________ 127,128, 135 

Cassel brown_____________ 651

Casseliase _____ 391
676 INDEX.

Page.

Casselose __________ _____ 387 

Cassiterite ________ 290-291, 591-595 

Castorina, G. T., radioactivity of

lava ___________ 259

Catapleiite _______________ 617

Catharinet, J., copper ores____ 568, 569

gold in pegmatite----_______ 553

sperrylite in pegmatite____- 611 

Cathrein, A., alterations of garnet- 336, 337 

chloritoid rock_..__ . 529 

epidotization ___________ 515 

leucoxene _______ 287

occurrence of chloritoid___ 330

psendomorphs after gehlenite_ 334

after scapolite ____ ___ 339

saussurite _____________ 513

titaniferous magnetite______ 286

Catjett, C., analyses by______ 479, 555

See also Clarke and Catlett.

Cayeux, L., chalk____________ 474

gaize_________________ 464

glauconlte____________ 440, 442

glauconitic iron ore___-___ 453

phosphatic nodules ___ 104

soils ________________ 431

Cecilose __________________ 330

Cedar River, analysis of water___ 70

Celadonite_______________ 440-441

Celestite __________ 178, 199, 497, 498

Cellulose _______________ 642, 643

Celsian___l______________ 300

Cementation, belt of__________ 502

Cements in sandstone______ 459-461

Centeno, J., analyses by_ _ 156

Cerargyrite _______ _ _ _ . 564

Cerite_________________ 617

Cerium, distribution._________ 15

sources of____________ 617, 618 

Cerussite________________ 586, 587 

Corvantite_______________ 598

Chabazite _______________ 349 

Chabrie", , Algerian saltpeter_ 205 

Chalcanthite_______________ 571 

Chalcedony ___________ 294, 295, 465 

Chalcocite____________ 567, 568, 569 

Chalcophanite______________ 580 

Chalcophyllite______________ 570 

Chalcopyrite__________ 567, 568, 569 

Chalcostibite__________'. ___ 569, 570 

Chalk_______________ 470, 474, 477 

Chalmers, R., peat___________ 648 

Chalmersite_______________ 567 

Chamberlin, R. T., gases from rocks_ 232 

Chamberlin, T. C., influence of 

oceanic carbonates on 

climate_____-__- 115

loess_________________ 433 

planetesimal hypothesis__ 51, 52,108 

zinc ores______________ 582, 583 

Chamberlin, T. C., and Salisbury,

R. D., volcanism __ 232-233 

Chamosite_______________ 331, 494 

Champlain, Lake, analysis of water_ 61 

Champlainiase _____________ 393 

.Chancourtois, E. de, metals in earth's 

: interior_________ 269

Page.

Chancourtois, E. de, water analysis. 130 

Chandler, C. P., analyses by__ 61, 62, 144 

Chaper, M., diamonds in pegmatite- 265 

Chaplin Lake______________ 126 

Charante, G. M. von, analysis of

water____________ 452

Charcoal ________________ 663-665 

Charcoal, fossil _____________ 649 

Charitschkoffi, K., synthetic hydrocarbons________ 629 

waters accompanying naphtha. 036 

Charlton, A. G., nickel ores_____ 598 

Charlton, H. W., analysis by____ 379 

Chastaing, . See.Bourgoin, . 

Chatard, T. M., analyses by____ 57, 120, 

121, 123, 124, 125, 190, 

191, 317, 390, 391, 463, 

468, 479, 492, 531, 604 

natural soda____________ 192

origin of corundum________ 278 

tallow clay____________ 583 

Chateau, , Algerian phos^

phates.___________ 448

Chaves, D. F. See Calderon, C. S.,

etc.

Chazal, P. E., phosphate rock____ 449 

Che"lif, River, analyses of water__ 59 

Cheltenham waters, analysis___ 145,146 

Chelu, A., sediment of the Nile___ 429 

water of the Nil.e ________ 82 

Chemical denudation________ 87, 88, 89 

Chenevixite _____________ _ 571

Cherrydale mineral water ______ 154 

Chert_____________..___ 464-467 

Chester, A. H., on waters of New

Jersey _________ 63 

Chester, F. D., epidotization____ 515 

Chevallier, A., cited_________ 96 

Chevandier, E., analj'ses of wood__ 643 

Chiastolite schist____________ 530 

Chicago drainage canal ___ 84, 85 

Chichen-Kanab, Lake, analysis of

water ________ 12(i, 136 

Chilenite_________________ 560 

Chiviatite ___..____________ 585 

Chloanthite_______________ 599, 601 

Chlorides in rainfall_________ 47 

Chlorine, distribution_________ 15 

in atmosphere __________ 47 

in potable waters ________ 47 

in sea water, origin of__ 107, 108, 109 

Chlorites ____l__________ 331, 332 

Chloritization _____________ 517,518 

Chloritoid_________ 327, 330, 529, 531 

Chloritoid-phyllite___________ 530 

Chlorophyllite______________ 340 

Chloropite ______________1_- 518 

Chlorothionite_____________. 221 

Chondrodite _______________ 520 

Chotose __________________ 376 

Christobalite_______________ 295 

Christy, S. B., synthesis of cinnabar__________ 574 

Chromic iron ore. See Chromite. 

Chromite____ 279, 281, 282, 604, 605, 609 

Chromium, distribution____ 15
INDEX. 677

Page. 

Chromium, ores of_________ 603-605

Chrompicotite_____________ 281

Chrustschoff, K., artificial diamond- 263

synthesis of hornblende ____ 320

of mica ___________ 328

of quartz and feldspar___ 302

of quartz and tridymite. 295, 296

of zircon___________ 291

Chrysocolla _____________ 571, 572

Chrysolite __________________ 324

Chuard, E., alteration of bronze___ 568

Church, A. H., siliciflcation of

coral _________ 439, 465 

Cimolite ________________ 4.17,527 

Cincinnati artesian well, analysis 142 

Cinnabar __________ 573, 574, 575, 597 

Ciplyte__________________ 446 

Claesson, C., dopplerite _______ 647 

Clapp, F. G., limestones_______ 478 

Claraz, G. See Heusser and Clara_z. 

Clark, T. E., fichtelite__________ 648 

Clark, W. B., greensand_______ 441 

Clarke, F. W., alteration of iolite__ 340 

analyses by _ _________ 57, 120,

122, 142, 150, 391, 479, 555, 603 

average composition of igneous

rocks ___________ 24-27 

brucite-serpentine ____ 348, 520-521 

constitutional formula_____ 518 

constitution of amphiboles___ 321 

of pyroxenes__________ 318 

evolution of the elements____ 12 

formula of cancrinite______ 309 

glauconite and greenalite__ 441, 493 

roscoellte ______________ 326 

solubility of minerals______ 405 

theory of chlorites________ 331 

Clarke, F. W., and Catlett, C.,

nickel ore ______ 601, 611 

Clarke, F. W., and Darton, N. H.,

iron mica _______ 326 

Clarke, F. W., and Diller, J. S., alteration of topaz____ 342 

nickel silicate___________ 602 

Clarke, F. W., and Schneider, B. A.,

calcination of talc____ 349

formation of spinel_______ 280 

micas and vermiculites ___ 331, 332 

Clarke, F. W., and Steiger, G., ammonium-analcite and 

leucite _________ 314 

vesuvianite ___ ________ 337 

Claudetite ___________________ 598

Claus, C., phosphatic sandstone ;_ 461

Clausthalite _______________ . 584

Claypole, E. W., tin deposits____ 594

Clays _________________ 430-432

dehydration of_________ 526-530

plasticity of___________ 425, 426

Clays, oceanic____ 101, 107, 436, 437, 438

Clear Lake, analysis of hot spring

near __________ 154

analysis of water_________ 70 

Clement, J. K. See Alien, E. T. 

Clements, J. M., iron ores____ 284

Page.

Clermont, P. de, and Frommel, J., 

solubility of sulphides ________ 544,545 

Cleveite _________________ 614 

Clinochlore ______________ 331, 332 

Clinoclasite_______________ 571 

Clinohedrite _______________ 580 

Clintonite ________________ 327 

Cloez, S., hydrocarbons in iron__ 628 

Clouet, .T., synthesis of chromite__ 604 

Clough, C. T., and Pollard, W., occurrence of olivine__ 325 

Clowes, F., barytic deposits____ 498 

harytic sandstones_______ 461 

Clowes, F., and Biggs, J. W. H., 

solubility of oxygen 

in sea water_____ 110 

Coal ___________________ 642-668 

Coates, C. E., and Best, A., petroleum__________ 622 

Cobalt, distribution____________ 15 

in ashes of sea weeds_____ 93 

ores of______________ 598-603 

Cobaltite ________________ 599, 601 

Cochenhausen, E. von, water analysis ____________ 119 

Codington, E. W., phosphate rock_ 450 

Cohen, E., matrix of diamond___ 264 

salt lake in Transvaal______ 133 

Cohen, E., and Raken, M., solubility

of calcium carbonate_ 99 

Cohn, F., travertine.-._______ 471 

Cold Spring Creek, analysis of water 70 

Cole, G. P. J., bauxite________ 420 

Coleman, A. P., anthraxolite____ 657 

coruudum-nepheline syenite 277 

heronite -_____________ 307 

nickel deposits__________ 600 

Colemanite ___________ 198,200,201 

Collet, L. W., phosphatic -nodules_ 104 

Collet, L. W., and Lee, G. W., glauconite _______ _ 441

Collier, A. .T., tin deposits_____ 594 

Collier, P., native platinum____ 608 

Collins, H. F., mercury ores_____ 573 

Collins, J. H., nickel deposits___ 601 

tin ores_______________ 592 

Collophanite ________________ 444 

Collot, L., distribution of barium

and strontium _ _ _ 498 

Collyrite-________________ 527 

Colomba, L., alteration of glaucophane__________ 323 

Colorado River (Argentina), analysis of water______ 74 

Colorado River (Arizona), analysis

of water ________ 69 

flow of________________ 70

Coloradoite ________________ 573 

Columbite _______________ 594, 616 

Columbium, distribution________ 15

sources _________.____ 616, 617 

Colvocoresses, G. M., cobalt ores _ 602 

Comanducci, B., copper and cobalt in

volcanic ash_______.. 543
678 INDEX.

Conchite ______.______ 

Conlchalcite _ _ ___ _ 

Connarite ___ _ ________

Conneautsville well, analysisPage. 

__ 473 

571 

603 

144

Consanguinity of rocks________ 253 

Contamination of river waters___ 84,

85, 86, 90 

Convection in magmas________ 257

Cook, B. H., cited___________ 43

Cook, G. H., clays__________ 431

greensand marl__________ 441

marl_________________ 472

 native iron_____________ 267

Cooke, J. P., vermiculites_______ 331

Cookeite _________________ 326

Cookose __________________ 389

Coolgardite __________________ 555

Ccomara-Swamy, A. K., Ceylonese

graphite _________ 266 

corundum ______________ 276

minerals in limestone_____ 539

Cooper, A. S., origin of petroleum_ 637

Copal ___________________ 644

Copiapo, Rio, analysis of water__ 74

Copper, distribution _________ 15

in sea water____________ 93

ores of______________ 564-572

Coppock, J. B., cited_________ 95

Coquand, H., antimony ores___ 597, 598

bauxite _________'____ 419

borates ______________ 198

itabirite ______:_______ 525

Coquina ________________ 476

Coral ___________________ 476 

siliciflcation of______ 439, 465 

Coral mud and sand____.1_____ 436 

Coral rock_____________ 476, 485-488 

Ccrdierlte ______________ 339, 340

Cornet, F. L., phosphatic chalk___ 448 

Cornet, J. See .Renard and Cornet. 

Cornish, V., and Kendall, P. F., calcite and aragonite in 

shells __________ 474 

Cornu,F., acid reactions of minerals- 403 

color of salt__________ 185 

hibschite, __ _ _ __ _________ 345

rock-forming apophyllite____ 350 

tests for calcite and dolomite_ 485 

Corongamite, Lake, analysis of

water_________ 133,134

Corse, M. B., and Baskerville, C.,

analysis by ______ 441 

Corstorphine, G. S., matrix of diamond _____^_____ 265

Cortese, E., hot springs of Venezuela- 196 

Cortlandtite _________..___ 390,391

Cortlandtose _ _ _ _ ___________ 391

 Corundophilite ______________ 331

Corundum ___.________ 274-279,537 

Corundum rocks________ 277,278,393' 

Corynite___________T ______ 599

Cosalite_________________ 562, 585

C'ossa, A., synthesis of scheelite 606 

tellurium in sulphur______ 220

volcanic sublimates _ 221 

Cossyrite _ __ _______________ 323

Page.

Costachescu, N., gases in salt _ _ 185 

Coste, E., origin of petroleum____ 633 

Cotunnite _____ _:___________ 587

Covellite _____ _________ 567, 568, 569

Cowen, J. L., arsenic mine _____ 597

Cox, E. T., antimony ores_______ 598 

phosphate rock__________ 450 

Craig, A. W., and Wilsmore, N. T. M.,

water analysis ____ 133 

Cramer, E., volatility of silica.___ 223 

Cransac, analysis of water from-_ 154 

Craw, J. W., analysis by_____ _ 155

Crawley, J. T., and Duncan, R. A., 

absorption of potassium by soils___ _ 166 

Credner, H., native copper _ _ _ 565 

Crednerite _ _ _ _ ____________ _ 571

Crocidolite_______________ 322, 323 

Crocoite_____ __________ 588, 589

Cronstedtite _____ _________ 331, 494

Crook, A. R., molybdenite.-_____ 606 

Crook, T., and Jones, B. M., geikielite_____________ 287

Crookes, Sir W., artificial diamond-- 264 

Crookesite_ _ _ _ _ ____________ 567

Crosby, W. O., coloration of clay__ 432

Crcsnier, L., crystallized sands___ 460

Cross, W., analcite basalt______ 306

analcite in phonolite _ _ 378

epidote____________--__ 515

garnet in rhyolite __ _ _ . 336 

phlogopite in wyomingite 330 

quartz-alunite and quartz-diaspore rocks _ 421 

sandstone dikes _________ 463 

topaz in rhyolite__ 342 

See also Iddings and Cross. 

Cross, W., and Hillebrand, W. F.,

cryolite __________ 274 

Cross, Iddings, Pirsson, and Washington, quantitative 

classification. ____ 357-365

Crossite ____________________ 322

Croton River, analysis of-water.,_ 62 

Cruzy well, analyses ________ 146 

Cryolite __________________ 274 

Cryophyllite ____________ 326,329 

Cryptomorphite ____ _!.______^ 203 

Crystallization, fractional, in magmas __________ 257

Cubanite _________________ 567 

Cumberland River, analysis of

water ___________ 66, 83 

Cumberlandite ________________ 394

Cumenge, E. See Friedel and Cumenge.

Cumengeite __ _ 587 

Cummingtonite________ 319 

Cundell, J. T., and Hutchinson, A.,

zincite __________ 580 

Cunningham, J. A., order of deposition of minerals--__ 252 

Cuprite ___________________- 571 

Cnprobismutite _____________ 570 

Cuprodescloizite ____________ 590 

Cuproiodargyrite _ 564
INDEX. 679

Cnprotungstlte ______________ 606 

Currie, J., cited, on Stassfurt salts- 176 

Cui-ry, J. E., water analyses_____ 68 

Curtis, J. S., gold and silver in

quartz porphyry____ 543

origin of lead ores_______ 590 

Cusack, R., melting points of minerals__^______ 239, 240 

Cushman, A. S., plasticity of clays_ 426

solubility of minerals_:____ 405 

Custerose ________________ 391 

Cyanite. Sec Kyanite. 

Cyanchroite______________ 221 

Cylindrite _____________ 58C, 591 

Cymatolite ________________ 315 

Cyrtollte ________________ 618

D.

Dacite ______________ 381, 382

Dahms, P., analysis by____ __ 508 

Dale, T. N., slate___________ 469 

Ball, W. IT., coquina _________ 476 

Ball, W. H., and Harris, G. B., Flor-

 Ida phosphates , _ 444 

Dallas, mineral spring near, analysis____________ 148 

Balmer, K., metamorphosis of phyllite_______ 332, 344, 528

Baly, R. A., magmatic stoping 256

pre-Cambrian ocean ___ _ 97,108

the fundamental magma_____ 25

Bamour, A. A., analysis by___ ___ 162

native platinum__________ 608

predafczite- _ _ 489

titanolivine_____________ 324

Damourite________________ 326

Dana, J. B., dolomitlzation_____ 486

gypsum and salt _ 183

serpentine .__________ __ 520

Bana, E. S., thinolite________ 123

See also Brush and Dana. 

Bana, E. S., and Penfleld, S. L.,'lead

silicate__________ 590

Bunalite- _______________ 580

Bannemorlte______________ 319

Danube River, analysis of silt___ 429

analyses of water_____ __ 79, 83

Dnphnite _______'__________ 331

Darapsky, L., analyses of caliche. 207

Chilean borates__________ 201

Chilean nitrates__________ 206

Barapsklte ______________ 206, 208

Barton, N. H., Florida phosphates_ 444

Sec also Clarke and Barton. 

Dathe, E., scapollte rocks___ __ 515 

Daubr<;e, A., alteration of bronze__ 568 

arsenic in sea water______ 92

arsenic and antimony In basalt- 543 

associations of platinum. __ 609 

calcination of serpentine_____ 348 

ferrous chloride in native iron_ 109 

formation of galena____ __ 585 

of hyalite and zeolites at

Plombieres________ 166 

of olivine____________ 324

Page.

Daubr6e, A., fossil charcoal-___ 649

origin of casslterite__~_ - 593

of native iron________ 269

sea water and volcanism_ 231, 233

solubility of orthoclase____ 303, 403

synthesis of apatite-! 292

of brookite__________ 289

of cassiterite________ 290, 591

of diopside ______ _ 314

of enstatite__________ 311

of hematite_________ 284

of quartz___________ 295

of topaz__________ 342

of zinc ores_______ 580, 581

zeolites at Plombieres______ 350

De.ubr6e, A., and Meunier, S., native

iron____________- 268 

Daubreeite________________ 598 

-Danbreelite______________ 603 

David, T. W. E., glendonite____ 123

matrix of diamond_____ - 265 

Davidson, W. B. M., phosphate rocks_ 444 

Davies, D. C., Welsh phosphates____ 448 

Daviesite _______________ 587 

Davis, C. A., marl___________ 472 

Davison, C., loess_____.______ 433 

Davison, J. M., platinum, etc., In

meteorites _ _ 609 

Dawson, H. M. See Van't Hoff, Kenrick, and Dawson.

Dawson, J. W., origin of gypsum_ 203, 495 

peat_____________ _ 648 

spore cases in coal_____ _ 666 

Dawsonite ________________ 422 

Day, A. L., melting points of minerals____ 239, 240, 241, 243 

Day, A. L., and Shepherd, E. S.,

akermannite silicate __ 333 

formation of quartz and tridymite ___________ 297

.lime silicates__________ 239, 248

phase rule __________ 250

volatility of quartz________ . 223

Day, A. L., and Alien, E. T., fusion

of feldspars___ _ 240

sublimation of.feldspars_____ 223

syntheses of feldspars_____ 300-302

Day, D. T., filtration of petroleum 640

phosphate rock-___ _ 450

platinum ______________ 609

Day, D. T., and Richards, R. H.,

platiniferous sands 609

Day, W. C., artificial asphalt_____ 630

gilsonite __________ _ 625

pitch coal____________ 625, 626

Dead Sea_____________ 128-130, 135

Death Gulch, water from___ 161

De Bennevllle, J. S., potash in beryl_ 347

Debray, H., synthesis of apatite 292

synthesis of pyromorphite 590

of scheelite ______ 606

of silver halides_______ 564

See also Devllle and Debray.

Dechen, H. von, cerussite sinter _ 587

Decomposition of rocks_____ 401-458

Dedolomitization ____________ 538
680 INDEX.

Page.

De Groot, H., California berates 198, 199 

De Gouvenain, , fluorine in

Vichy water ______ 149 

Delaware River (Kansas), analysis

of water________ 68 

Delaware River (N. J.), analyses

of water -____ - 63 

Delebecque, A., and Duparc, L.,

French lakes__-___ _ 76 

Delessite _________________ 331 

Delkeskamp, R,, barium in natural

waters _____ 160, 461, 498 

bauxite _______________ 420 

vadose and juvenile carbonic

acid__________-,_ 169

Delvauxite _______________ _ 612

Deniargay, E., vanadium_______ 61.2

Demel, W., dopplerite_________ 647

Dennis, W. D., cited__________ 201

Denudation, chemical_______ 87, 88, 89

Denver, spring near, analysis-_ 146

Derby, O. A., Brazilian diamonds__ 265

Brazilian topaz _____:____±. 342

disintegration of rocks______ 407

gold on limonite-__ 556 

manganese ore____ __ 456 

novaculite _ _ _ _ __________ 464

occurrence of monazite and xenotime-___-_____ 293,294 

Derbylite _____ ____________ 598

Desaulesite _____ _________'__ 603

Des Cloizeaux, A., formation of anorthite_-________ 301

nickel ores______--_ 600 

Descloizite _____ __________ 580, 590

Deville, C. Sainte-Claire, fumaroles

of Vesuvius______- 213

volcanic gases ________._ 214, 215 

volcanic sublimates________ 221 

Deville, C. Sainte-Claire, and Leblanc, F., boric fumaroles____________ 198

Deville, H. Sainte-Claire, synthesis

of cassiterite_____ 290, 591

synthesis of dolomite- __ 480

of hematite_________ 284

of magnetite_________ 283

of willemite_________ 581

of zeolites__________ 350

titanium and vanadium in bauxite ___________ 423,612 

topaz_________________ 342

water analyses__________ 76, 77 

Deville, H. Sainte-Claire, and Caron, 

H., synthesis of apatite-----_______ 292

synthesis of cassiterite____ 291, 591 

of gahnite __________ 581 

of pyromorphite_ . 589 

of rutile____________ 289 

of staurolite ( ?) ______ 344 

of zircon ____________ 291 

Deville, H. Sainte-Claire, and Debray, H., native platinum. _^_______ 608

Page.

Deville, H., synthesis of cinnabar__ 574 

Deville, 1-1. Sainte-Claire, and Troost, 

L., occlusion of gases 

by glass_________ 226 

synthesis of greenockite and

wurtzite _________ 578

Deville, H. Sainte-Claire, and Wohler If., boron nitride_ 197 

Dewar, J., cited_____________ 41 

Dewar, J., and Ansdell, G.. gases in

meteorites _____ 234 

D'eweylite _______________ 349

De Wilde, P., gold in sea water___ 93 

origin of petroleum_______ 634 

Diabantite ________________ . 331 

Diabase ___________ 387-388, 412, 413 

Diallage ________________ 314, 508 

Diamond ________________ 262-265 

Diaphorite ______________ 562, 585 

Diaspore __________ 418, 419, 421, 422 

Diatom ooze_____________ 101, 436 

Diatoms, as sources of petroleum__ 638 

Dick, A. B., minerals in sand____ 427 

Dickson, C., formation of barite__ 500 

Dickson, C. W., nickel deposits___ 601 

platinum ores __________ 611 

Dickson, E. See Holland and Dickson.

Dieffenbach, O., gold on siderite__ 556 

Diersche, M., origin of graphite__ 266 

Dietze, A., water analysis______ 74 

Dietzeite ________________ 207, 604 

Dieulafait, L., ammonia in sea water_ 92 

bitumen in shale_________ 635

boric acid in natural waters_ 153 

Chilean nitrates__________ 208 

copper in sea water______ 93 

lithium in sea water_______ 92 

manganese in sea \vater____ 93 

manganese nodules ________ 103 

origin of borates_____,___ 204 

precipitation of iron ores____ 490 

serpentine _ ________ __ 521

thermochemistry of iron and

manganese _____ 457, 458

vanadium ____________ 612

zinc and copper in rocks____ 544

zinc in limestone-________ 582

in sea water-________ 93

Diller, J. S., alteration of pyrope__ 337

loess _________,______ 433

melilite and gehlenite in slags_ 333

occurrence of perofskite_ _-_ 287

priceite _______________ 200

quartz basalt ___________ 299

sandstones ___________ 462, 463

See also Clarke and Diller.

Diopside _________________ 314

melting point___________ 240

Dioptase _________________ 572

Diorite ___________ 383, 384^412, 413

Dipyre _________________ 338

Dissociation in magmas_______ 395

Ditte, A., metals in the atmosphere_ 48

origin of vanadates_______ 613

synthesis of apatite______ 292
INDEX.

"681

Page.

Ditte, A., synthesis of cassiterite__ 291,

591,592

synthesis of cinnabar_____ 574 

of greenockitc ___ __ 579 

Dittmar, W., analyses of dissolved

aif _______ 111, 112, 113

analyses of ocean water_--__ 94

oceanic salts___________ 23

water of Hayes River_- _- 71

Dittmarite ________________ 444

Ditroite ___________________ 376

Dittrich, M., decomposition of rocks_ 411,

425 

relations between spring waters

and rocks ___ _ 168 

Ditz, H. Sec Donath and Ditz. 

Divers, E., and Shimidzu, T., tellurium in sulphur __ 220

Dodge, J. A., analyses of water_ 64, 65, 70

Doelter, C., alteration of andalusite_ 344

constitution of pyroxene____ 318

formation of augite_______ 317

of anorthite _________ 301

of magnetite_________ 283

of melilite__________ 334

of spinel__________ 280, 281

fusibility'of rocks________ 242

fusion of clinochlore_______ 332

of epidote __________ 340

of garnet___________ 335

of glaucophane_______ 323

of micas' ___________ 330

of tourmalinel-______ 347

gehlenite in limestone______ 537

magmatic dissociation______ 246

melting'points of minerals__ 239,240

solubility of cassiterite__ -__- 592

of minerals__ 290, 405, 545, 596

solvent of gold__________ 557

stability fields of minerals__ 250, 253

synthesis of acmite___ _ 315

of bournonite ________ 570

of cinnabar_______:__ 574

of covellite and chalcopyrlte ___________ 568 

of feldspar__________ 302 

of galena___________ 585 

of hornblende________ 320 

of jamesonite________ 586 

of leucite___________ 305 

of melonite_________ 338 

of mica___________ 328, 329 

of nephelite and. kaliophilite____________ 308

of olivine___________ 325

of pyrite and pyrrhotite__ 272

of sulphosalts_______ 563

of wollastonite___ ___ 313

of zeolites__________ 350

volcanic explosions_______ 232

Doelter, C., and Hoernes, R., dolomitization _________ 487 

Doelter, C., and Hussak, E., formation of anorthite_____ 301 

formation of melilite_______ 334 

of spinel___________ 281

Page. 

Doelter, C., and Hussak, E., fusion of

garnet _________ 335

fusion of mineral mixtures__ 255 

of vesuvianite_______ 337

Doering, , analysis by_____ 189 

cited ________________ 126 

Doherty, W. M., manganese nodules. 455 

Dole, R. B., and Roberts, M. G.,

analyses of waters. 61, 

62, 63, 66

Dolerophanite _____________ 221 

Dolomite____________ 351, 480-490 

Domeykite________________ 567 

Domoshakovo, Lake, analysis of

water_________ 131, 135 

saline deposits__________ 187

Don, J. R., distribution of gold__ 554 

gold in sea water _____ 93

solvent of gold__________ 557 

Donath, E., action of nitric acid on

coal __________ 652 

resinoids in lignite_j.______ 651 

Donath, E., and Briiunlich, F., reactions of lignite_____ 652 

Donath, E., and Ditz, H., reactions

of lignite________ 652

Dopplerite_______________ 647, 648

Doss, B., anatase pseudomorphs___ 288

artificial hematite ________ 285

pseudobrookitc __________ 287

sand in gypsum _______ 460

synthesis of rutile and anatase_ 289 

Doughty Springs____________ 160 

Douglasite_______________ 179, 180 

Drasche, R. von, eclogite_______ 516 

Drevermann, A., syntheses of lead

ores __________ 589

Drown. T. M., chlorine maps___ 47 

Duboin, A., synthesis of kaliophilite_ 308 

synthesis of leucite __ 305 

Dubois, E., atmospheric transport of

salt ____________ 48 

circulation of calcium carbonate____________ 100 

ratio of sodium to chlorine in

rivers __________ 108 

Du Bois, G. C., laterite_______ 418 

Ducatte, F., sulphosalts of copper 570 

sulpbosalts of lead____ __ 586 

Ducloux, E. H., cited_________ 94 

Dudley, W. L., vivianite______'_ 443 

Duffleld, S. P., analysis cited____ 141 

Dufrenite __________________ 443 

Dnfrenoysite _____________ 585, 586 

Dumas, J. B., origin of boric acid_ 198 

synthesis of argentite______ 560

Dumble, E. T., grahamite______ 626 

iron ores_ __ 494

Dumont, J., decomposition of potassium carbonate by clay- 425 

Dumortierite _______._______ 345, 346

Duncan, R. A. See Crawley, .1. T. 

Dundasite ______ ____-_- 586

Dunin-Wasowicz and Horowitz, ,T.,

analysis by_____- 145

Dunite __________________ 390, 391

Dunn, W. H., analysis of salt__^_ 184
682 INDEX.

Page. 

Dunnington, F. P., deposition of

manganese ______ 458 

titanium in clays 20 

Dunose ____- " 391 

Du Ponteil, C., analysis by __ 156 

Duparc, L., pisolite 473 

Uralian platinum ______ 609 

See also Delebecque,. A. 

Duparc, L., and Horn.ung, T., uralitization________ 310,507 

Durand-Claye, L., cited __ __ 95 

Durocher, .T., copper sulphide____ 567

.liquation in magmas _ 257 

synthesis of argent!te______ 560 

of cinnabar_______"__ 574 

of dolomite__________ 480 

of galena __________ 584 

of greenockite and sphalerite____________ 578 

of pyrite ___________ 272 

of stibnite and bismuthinite- 596 

of sulphosalts________ 562 

the fundamental magmas ____ 254

Dust, atmospheric___________ 48

Dutoit, A. L., matrix of diamond__ 265 

Button, C. E., radioactivity and volcanism__________ 259 

Dwina, River, analysis of water__ 81 

Dyscrasite ___ __ _ _ 560 

Dysprosium __ ________'______ 15

Eakins, L. G., analyses by 146, 2SO, 317,

367, 374, 383, 384, 385, 390,

391, 434, 468, 479, 4S9, 530

fluorine in fossil bone_____ 447

xanthitane _____________ 288

Eakle, A. S., lawsonite________ 345

East Saginaw, brine, analysis of___ 141

Ehelmen, .T. .T., synthesis of beryl_ 347

synthesis of bunsenite _____ 602

of chromite_________ 604

of enstatite __________ 311

of forsterite _________ 324

of gahnite __________ 580

of magnetite ________ 283

of perofskite_________ 287

of rutile____________ 289

Ecdemite _________________ 590

PJckel, E. C., gypsum__________ 185

limestone and cement______ 478

phosphorite _ __________ 449

slate ________________ 469 

See also Hayes and Eckel. 

Eclogite ______________ 265, 516, 517 

Edenite _________________ 319 

Edgar and Mariner, analysis of

water ________ 66 

Edingtonite _______________ 350 

Eger River, analyses of water____ 77, 78

Egleston, T., solvents of gold__,_ 557 

Eglestonite __ ______ _ 573

Ehrllch, F. Sec Kolkwitz, R.

Eisenhuth, K., analysis by______ 492

Elffiolite__________________ 307-309 

Elseolite syenite___________ 374,412 

Elaterite _______.________ 624

Page.

Elbe River, analyses of water. 78

Elbow River, analysis of water__ 72

Eldridge, G. H., asphalt______ 625, 627

Florida phosphates'-_______ ' 450

Electrum _________________ 555

Elements, distribution________ 13-21

nature ___________'____ 12, 13

periodic classification_____ 33-36

relative abundance ________ 21-33

table of_______________ 13

Ellis, E. E., zinc deposits_______ 583

Ellis, W. H., anthraxolite______ 657

Ells, R. W., inanjak__________ 626

Elton Lake, analysis of water__ 130, 135

Embolite _________________ 564

Emerson, B. K., amphibolite_____ 510

andalusite and sillimanite___ 528

emery ____ _ _ 278

serpentine -._______________ 520

Emery __________________ 278,424

Emmons, S. F., fluorite_______ 500

loess ___L. _________________ 433

ores of Leadville_________ 590 

platipum _______.____ _ 611

secondary enrichment______ 552 

serpentine _____________ 520 

silver in eruptive rocks_^_ _ 543 

zinc ores___ ____:_ . 583

Emplectite ______________ 569, 570 

Enargite _________________ 570 

Endemann, I-I., asphalt________ 627 

Endlichite ________________ 589 

Engelh'ardt, F. E., analysis by___ 141 

Engler, C., artificial petroleum____ 630 

origin of petroleum__ 634, 635, 639 

Engler, C., and Lehmann, T., .artificial petroleum_ _ 630 

Enstatite _________________ 311-313 

melting point-___ ___ __ 240 

Epiboulangerite ____________ 585 

Epichlorite --____ _______ 331

Epidosite __________________ 516 

Epidote ___________________ 340, 341

Epidote rocks_________:_____ 515, 516

Epidotization ______________ 515, 516 

Epigenite ___ 570 

Epistilbite ________________ 350 

Epsomite________________ 178, 179

15

130

22fi

Erbium ________________

Erdmann, , water analysis___ 

Erdmann, H., nitrogen in minerals_ 

Erhard, T., melting points of minerals____________ 238 

Erie, Lake, analysis of water 61 

Erinite __________________ 570 

Erionite _________________ 350 

Erofe"ef, M., and Latschinoff, P., diamonds in meteorite-_ 264 

Erwin, R. W., cited__________ 46 

Erythrite _____________-__ 602 

Erythrosiderite_____________ 221 

Essexose ________:_______ 373, 386 

Etard, A., and Olivier, L., reduction 

of sulphates by microbes _________ 496

Ettinger, . See Franck and Ettinger.
INDEX. 683

Page.

Eucairite ________________ 562 

Eucryptite ______________ 307, 309 

Euctolite _________________ 386 

Eudialyte ________________ 617 

Europium' ________________ 16

Eutectics_______"_______ 247-250 

Euxenlte ___'. ___________________ 616

Evansite _________________ 443 

Evans, ,F. W., and McCreary, P. L.,

water analysis..___ 70 

Evans, .T. R., analysis of water.,__ 64, 68 

Evans, T. W., analcite in nionchiquit.e 306 

quantitative classification____ 365 

Evans, N. N., analysis by______ 534 

Eve, A. E., radio activity______ 260 

Ewald, , analysis by --- ____ 161

Ewing, A. L., limestone erosion___ 480 

Excelsior Spring, analysis__ __ 149

Fahlunite ________________ 340 

Failyer, G. I-I. See Schreiner and

Failyer.

Failyer, G. H., and Breese, C. M., 

nitrogen compounds in 

rain __ ____ ___

Fairbanks, H. W., analcite-diabase_ 

tin deposits. ________ 

.Fairchild, H. L.| planetesimal hypothesis_____.___ 51,108 

Ffiirhaven Springs, analysis______ 150

Famatinite _________________ 570

Farrington, 0. C., formula of iolite. 339

Farup, P. See Van't Hoffi and Farup.

T'aujaslte_____'___________ 350

Fuyalite_____________ 323-325, 357

Feather River, analysis of water.'_ 70

Feldspars _______________ 300-304

alterations of_ ... ... 510-517

melting points __1 ________ 240, 241

sublimation of __________ 223 

Femic minerals.___...______ 359

Fennel, A. C. See Judge, J. F. 

Fenneman, N. M., petroleum___ _ 622 

Fergusonite___ 618 

Former, L. L., manganese ores in laterite_________... 419 

Fernandez and Bragard, analyses by_ 499 

Fernekes, G., precipitation of copper. 566 

Ferrieres and Dupont, synthesis of

bunsenite____ ___ 602 

synthesis of zincite..._____ 580

Ferrodolomite._ ... 492 

Fibrolite __________________ 343 

Fichtelite_________________ 624, 648 

Fiedlerite ________._______ 587 

Field, F., analysis by_ . ____ 493

synthesis of copper minerals. 571, 572 

Finckh. L., serpentine from gabbro. 348 

Finley, G. T., dumortierite in pegmatite_____________ 346 

Fircks, W. von, tin deposits. _ 593

See Beck and Fircks.

Fischer, F., coal analyses.______ 654 

Fiscuer, H., mercury deposits 577

I'age.

Fischer and Rust, microscopic structure of coal_______ 666 

Fischer, T. See Wedding and Fischer. 

Fischerite_______ ...__ 443 

Fish Creek, analysis of water____ 72 

Fisher, 0., internal temperature of

the .earth________ 238

Fitch, E. S., analysis of bittern__ 186

Flagg, .T. W., Chilean nitrates__ __ 200

Flechsig, R., analysis by_______ 151

Fleck, FT., water analysis.______ 129

Flint_________________ 294, 464, 467

Fliickiger, F. A., analysis by_ : .150

Fluocerite _______________ 274

Fluorine, distribution___j____ 16

free, in fluorite '_ ____ 274

in mineral waters 149

in sea water __ _ _ 91

Fluorite_____________ 273,274,500

melting point__________ 240

Fluorspar. See Fluorite. 

Foerste, A. F., Clinton iron ores__ 453

Fiirstner, H., wurtzitq as furnace

product '___ 578 

Foote, E. A. See Koenig and Foote. 

Foote, H. W., analyses by 281,

379,386,604

calcite and aragonite____ 473 

See also Penfield and Foote. 

Foote, W. M., leadhillite_______ 588 

Forbes, D., borate from hot springs. 205 

Chilean nitrates__________ 206 

South American borntes. 201 

Forbes, E. H. See Penfleld and

Forbes. 

Forbes, R, H., and Skinner, W. W.,

water analyses____ 69 

Forbesite'_________________ 602 

Forchhammer, G., chemistry of the

ocean ___________ 9.1, 93

heavy metals in rocks _____ 542

magnesia in shells and corals_ 485

synthesis of apatite_______ 292

Ford, W. E., formula of dumortierite 345

See also Penfleld and Ford. 

Forel, F. A., on Lac Leman_____ 76 

Formaldehyde in atmosphere __ 41 

Formenti, C., bauxite_______- 421 

Formula?, constitutional.________ 518 

Forsberg, , cited _ .._ 94, 96 

Forsberg, E. See Geuther and Forsberg.

Forsterite __.__________ 323-325, 357 

Forstner, W., mercury ores_;___ 577 

Foster, C. Le Neve. See Bauerman

and Foster.

Foulk, C. W., analysis cited _____ 141

Foullon, H. B. von., gummite ___ 614

nickel deposits _________ 600, 602

rhodusite ______________ 322

Fouqu<§, F., formation of melilite__ 333

magmatic differentiation____ 245

steam from Etna______ __ 212, 213

volcanic gases______ 215,217,218

Fouqu6, F., and Gorgeix, H., boric

fumaroles __ 198
684 INDEX.

Page. 

Fouque", F., and' Michel Levy, A.,

crystallization of silica. 298

formation of hematite- _ 285

of magnetite_______ _ 283

of melanite__________ 336

of nephelite_______:_1 308

of spinel ___________ 281

fusion of biotite and microcline_ 376

of scapolite rock__ 338

scapolite gabbro 514

synthesis of augite ___ _ 317

of enstatite _________ 312

of feldspars________ 301, 302

of leucite___________ 305

of melilite___________ 333

of mica trachyte ______ 328

of olivine___________ 324

Fournet, J., synthesis of chalcopyrite____________ 567

synthesis of zinkenite__ 586

Foyaite ____-_-___________ 376

Fraas, 0. F., formation of bitumen_ 636 

France, lakes of- _ _ 76 

Franchi, S., glaucophane rocks___ 509 

jadeite rocks__ _ ___ 316 

Franchi, S., and Stella, A., lawsonite in schist______ 345 

Franck, L., and Ettinger, diamonds

in steel __________ 263 

Franckeite ________________ 586, 591

Frankforter, G. B., water from

Death Gulch______ 161 

Frahkland, P. F., coal gas_______ 659 

water analysis__________ 73 

Franklin, E. C. See Bailey, E. H. S. 

Franklinite ____ 279, 580, 581, 583, 584 

Frazer, J. C. W. See Kastle, J. H.,

etc.

Frazer, P., classification of coals_ 659, 660

Frear, W., and Beistle, C. P., soils. 431

Freda well, analysis cited_____ 144

Freda, G., volcanic sublimates____ 221

Freis, R., fusion of mineral mixtures 252

Freieslebenite _____________ 562, 585

Fremy, E., artificial coal______ 664

humic substances in coal.____ 651

synthesis of anglesite______ 588

of cerussite_______ 587

Frenzel, A., Bolivian tin ores_____ 591

formula of pseudobrookite___ 287

Fresenius, C. R., analysis by____ 143

manganese and iron in spring

waters-___.______ 457

Friedel, C., diamond __________ 263.

lead oxychlorides .____ ___ 588

nesquehonite ___ _ _ 483

synthesis of atacamite _ _ 571

Friedel, C., and Cumenge, E., carnotite___________ 615

Friedel, C. and G., alteration of muscovite_______1_ 330 

artificial cancrinite _______ 310 

conversion, of muscovite into nephelite _ _ _ _______ 308

formation of leucite________ 305 

syntheses of feldspars 301, 302

Page. 

Friedel, C., and Guerin, J., synthesis

of ilmenite _______ 286 

Friedel, C., and Sarasin, E., formation of quartz and feldspar__________!___ 302

synthesis of analcite _____ 305

of hopeite __________ 580 

of phosgenite________ 587 

of quartz and tridymite__ 295 

of topaz_________ 342

Friedel, 'G., hydration of analcite__ 304

lead oxychlorides _ _ _ _ 58~8

synthesis of corundum _____ 275

Friedliinder, J., artificial diamond__ 263

Frieseite _________________ 562

Frio, Rio, analysis of water-_____ 74

Friswell, R. J., action of nitric acid

on coal _ _ 652 

Frochot, M., tin deposits_______ 595

Frommel, J. Sec Clermont and

Frommel.

Friih and Schroter, peat_______ 647 

Fuchsite_ _ _ _ ______________ 326

Fuller, M. L., corrosion of quartz- 300, 406 

.Fuller's, earth______________ 431 

Fumaroles- ___ ___________ 212-220

Fumaroles, boric_____ 196, 197, 198 

Funafuti, atoll of____________ 487 

Fyris, River, analysis of water. _ 81

G.

Gadolinite--_______________ 618 

Gadolinium ________________ 16 

Gabbro _ _ _ _ _ _____________ 388-390

Gaertner, A., bog-iron ore_______ 452 

Gages, A., synthesis of serpentine_ 348 

Gahnite __________ 279, 580, 581, 584 

Gaize ___________________ 464, 460 

Gale, H. S., carnotite_________ 615 

Gale, L. D., cited____________ 119 

Galena.______________ 584-590

Galena, volcanic _____.._____ 222, 229 

Galenobismutite ____________ 585 

Gallium, distribution _________ 16 

Ganomalite _______________ 590 

Garda, Lago di, analysis of water_ 80 

Garnet _________________ 334-337 

Garnet rocks __________ 516, 517, 539 

Gamier, J., nickel deposits____ 601, 603 

Garnierite ________________ 603 

Gas, natural__________ 620-621, 633 

Gases in coal_____________ 660-663 

Guukhane Lake, analysis of water- 130, 134 

Gautier, A., arsenic in sea water__ 92 

chemistry of volcanism______ 230, 233

decomposition of galena____ 585 

hydrogen in atmosphere-____ 40, 41 

iodine in sea water.'______ 91 

minervite ____________ 445, 446 

nitrogen, argon, arsenic, iodine

in granite_______ 368 

occluded and volcanic gases_ 226-231 

origin of nitrates __'.________ 209

reduction of copper sulphide_ 566 

thermal springs and volcanism__________ 168,169
INDEX. 685

Page.

Gautier, P., tin deposits _ 593 

Gay Lussac, cited__________ 45 

formation of hematite _____ 284 

Gaylussite ___________ 123, 191, 200 

Gedrite ________________ 318,319 

Gehlenite _______________ 333,334 

Geikie, Sir A., bog-iron ore_____ 452 

^elevation of continents_____ 29 

order of magniatic eruptions ___ 256 

saline matter in rivers____ 89 

temperature of molten lava_ 243 

Geikielite ________________ 287 

Geitner, C., synthesis of argentite 560 

synthesis of beyrichite___ _ 600 

of greenockite _______ 579 

of pyrite____________ 272 

Genesee River, analysis of water._ 61, 83 

Genth, F. A., alteration of corundum___________ 280 

alteration of orthoclase to albite____________ 304

of talc___________ 319, 349

analyses by __________ 129, 524

gummite ________-____ 614

lansfordite ____________ 4S3

pseudomorplious cassiterite__ 592

vermiculites ____________ 331

Genth, F. A., and Penfield, S. L.,

uesquehonite _____ 483 

Genthitc _________________ 603 

Geocronite ______________ 585

Geological thermometer_______ 182 

Gerhardtite________________ 572 

Germanium ___________ 16

Gersdorfflte ________________ 599 

Geuther, A., formula of gypsum__ 178 

Geuther, A., and Forsberg, E., synthesis of wolframite-- 606 

Geyserite ________________ 162 

Gibb, A., and Philip, R. C., precipitation of silver sulphide _______.._ 561 

Gibbsite __________ 418, 419, 421, 422 

Gibson, J., analysis of manganese

nodule ________ 103, 104 

Sec also Irvine, R.

Gigantollte ____'___________ 340 

Gil, J. C., fluorine in spring waters- 149 

Gila River, analysis of water_____ 69

Gilbert, G. K., Lake Bonneville___ 118

mirabilite at Great Salt Lake_ 387

salts of Sevier Lake_______ 188

tufa ____..__________ 471

Gilbertite ________________ 326

Giles, W. B., bakerite_________ 200

Gillnian, F., nickel deposits_____ 601

Gilsonlte ________________ 625, 630

Girard, C., and Bordas, F., spring

deposits _______ 160 

Girardin, .T., magnesian travertine_ 481 

Gismondite _______________ 350 

Glaser, M. See Kalmann, W. 

Glaserite _________________ 178, 182 

Glass, occlusion of gases by____ 226

Glasser, B., nepouite_______ COS

Page.

Glauberite ______ 178, 182, 199, 201, 202 

Glaucochroite _____________ 324 

Glaucodot - ____ 599

Glauconite ___105, 106, 439-442, 453, 492 

Glaucophane _____________ 322, 323 

Glaucophane schists _ ___ 508-510 

Glendonite _________________ 123 

Glenn, W., chromite deposits_____ 605 

Glinka, K., glauconite_______ 440, 441 

kaolin ______________ 423 

Globigerina ooze________________ 101, 436

Giucinum, distribution_______ 16 

Gmelinlte __________________ 350 

Gmundenersee, analysis of water__ 80 

Gneiss ______________ 412,534,535 

Godeflroy, R., analysis of water____ 80

Goessmann, C. A., analyses by_ 141, 185 

Goethite ____________ _ 451

Gotz, ,T., ottrelite rocks_______ 529

Gold, distribution____________ 16

in igneous rocks 271

in sea water____________ 93 

ores of______________ 553-558 

solvents of _____^______ 557

Goldberg, A., cited__________ 151 

Goldschmidt, V., composition of tourmaline __________ 346

Gooch,-F. A., analyses by_______ 159 

Gooch, F. A., and WhitQeld, J. E.,

analyses by__ ____ 150, 

151,153, 155 

Goodenough Lake, analysis of

water ________ 125,136 

Gorby, S. S., petroleum________ 639 

Gorgeix, I-I. See Fouqufi and Gorgeix. 

Gordon, C. H., change of augite to

hornblende _______ 508 

nomenclature of gneiss_____. 534 

Gorgeu, A., analyses by_______ 455 

synthesis of fayalite_______ 325 

of pseudo-wollastonite___ 313 

of pyroxene __ ____ 314 

of spessartite________ 336 

of willemite _________ 581 

of zincite___________._ 580 

Gorgeu, A., and Silber, P. G., synthesis of nephelite __ 308 

Gortner, R. A. Sec Alway, F. J. 

Gorup-Besanez, E. von, formation of

magnesian carbonates- 481 

Goslarite ________________ 580 

Gosling, E. B., ozokerite_______ 625 

Goss, A., water analysis_______ 69 

Gosselet, .T., phyllites_________ 529 

Gossner, B., on glaserite_______ 178 

Gottlieb, E., analyses of wood___ 643 

Gouvenain, C. A. de. alteration of

bronze __________ 568 

Goyder, G. A., sulvanite_______ 613 

Grabau, A. W., classification of sedimentary rocks _____ 459 

Graftiau, J., cited____________ 42,46 

Graham, T., colliery gases______ 663 

gases from meteorites._____ 234
686 INDEX.

Page.

Grahamite ______________ 624-626 

Gramann, A., alteration of andal-

- usite____________ 344

Grandjean, formation of dolomite_ 486

Granite _____ 360, 366, 368, 398, 412, 533

fusibility _____________ 242

radioactivity of__:________ 260

sulphur waters from _______ 169

Granitite _;.________:_______ 366

Grant, U. S., zinc deposits______ 583 

Graphite _____________ 266-267, 537 

Graphitic acid_____________ 657

Graphitoid ________________ 657 

Graton, L. C., tin deposits_____ 291, 594

See also Hess and Graton. 

Gray, , cited by Warington___ 47 

Graywacke _ ________ ___ 462 

Great Salt Lake, analyses of

water _________ 119, 134 

Greenalite _________ _ 284, 492, 493 

Greenleaf, J. L., flow of the Mississippi___________ 65

Greenlee, W. B., volume of ground

water____:__:__ 22 

Greenockite _ .___________ 578, 579

Greensand. See Glauconite. 

Greisen __________________ 593 

Greshoff, M., analysis by, cited__ _ 154 

Griffiths, A. P., mercury ores_____ 577 

Grimsley, G. P., clays_________ 431 

gypsum _____________ 185 

Griswold, L. S., novaculite______ 464 

Groddeck, A. von, sericitic rocks__ 511 

topazfels __ _____________ 342 

Grossularite ______________ 334-337 

Groth, P., constitution of kyanite__ 343 

Ground water, volume of_______ 22 

Grout, F. E., plasticity of clays__ 426 

Grubenmann, U., crystalline schists 506, 507 

glaucophane rocks-_______ 509

Grunerite ________________ 319 

Griinerite-magnetite schist______ 526 

Griinlingite _______________._ 595 

Guano _________________ 444-450 

Guadalcazarite _____________ -573

Guanajuatite ______________ 595

Giimbel, C. W. von, chloropite____ 518

compression of lignite______ 663

dolomite ___ ___________ 485

glauconite _____________ 440 

itablrite ______________ 525 

origin of manganese nodules__ 103 

Gunther, R. T., and Manley, J. J.,

water analysis_____ 130 

Gue'rin, J. See Friedel and Gu6rin. 

Giirich, G., ore deposits_______ 541 

Giieymard, B., platinum in chalcocite____________ 610 

Guignet, E., action of nitric acid on

coal ___________ 652 

Guignet, C. E., wax from peat____ 638 

Guitermanite ._____________ 585

Gummite _________________ 614

Gunnarite ________________ 599

Gurlt, A., talc_____________ 522

tungsten deposit_________ 607

Page.

Gustavsen, C. N.,. analysis of water. 68 

Guthrie, F., change of obsidian to

pumice _____..____ 244

cryohydrates__________ 247

eutectics ______________ 356

Gutzkow, F., analysis of bittern_ 185, 186

Gypsum___ 178, 181, 182, 183, 185, 197,

199, 201, 202, 460, 494, 495

Gyrolite______ _ _____ ___ _ 350

Gytje- - - - - 438

H. 

Hackmannite ____________ 309

Haefcke, H., constitution of hornblende _ _ _ _ ______ 321

Haefele, P. E., alteration of andalucite___________ 344

Hagele, C. See Hell and Hiigele. 

Haeussermann, F., and Naschold,

W., coal analyses.-.- 656 

Hague, A., origin of Yellowstone

hot springs__ 168

scorodite in spring deposit__ 163,

164, 596

Hahn, H., hydrocarbons in iron:__ 627 

Hahn, H. C., analysis by__ 141 

Hale, D. J., marl_____________ 472 

Halite ___'.___________________ 179,180

See also Salt. 

Hall, C. W., and Sardeson, F. W.,

dolomite _____ ___ 486

Hall, Sir J., artificial coal______ 664

fusion of limestone_______ 477 

Hall, R. D., and Lenher, V., tellurides_______ 556, 558, 562 

Halloysite ____________ 417, 424, 527 

Halotrichite _____ ___________ 211

Halse, E., mercury ores_________ 573

tin deposits____________ 593 

Hamberg, A:, cited__________ 111

native lead-________ _ 584 

Hammerschmidt, F., cited______ 182 

Hanamann, J., waters of Bohemia_ 77,

78,79

Hancock, D. See Phillips and Hancock.

Hanks, H. G., California borates. 196, 198 

Hanksite _________________ 200 

Hannay, J. B., artificial diamond__ 263

occlusion of gases by glass _ 226 

Hannayite_________ _____ 444

Hardin, M. B., analysis by_____ 155 

Hardman, E. T., analysis by_____ 466

See also Hull and Hardman. 

Hardpan _ _ _ _ _ ___ ____ _ 40!) 

Hardystonite _ _ _ _ __________ 580 

Harker, A., average composition of

igneous rocks_____ 24-25

crystallization of magmas___ . 257

primary iolite___________ 339 

Harkness, R., dolomite________ 487 

Harmotome____________ _ 350

Harney Lake, analysis of water 125, 136 

Harper, H. W., asphalt________ 627 

Harperath, L., Argentine salt_ 184

petroleum and salt 639
INDEX. 687

Page.

I-Iarrington, B. J., analyses by__._ 508 

bornite__________:____ 567 

hydrogen sulphide in calcite- 224, 470 

See also Adams and Harrington. 

Harris, G. D. 'See Ball and Harris. 

Harrlson, J. B., heavy metals in

rocks _.________ 544 

Harrison, J. B., and Jukes-Brown,'

A. J., coral rock..__ 476

red clay. 

Ha prison, J.

436

B., and Williams, J., 

chlorides in rain___ 47 

nitrogen compounds in rain_ 4t> 

Harrogate, analyses of waters____ 143 

Hartite _______"___________ 624 

Hartleb, R. See Stutzer and Hartleb.

Hartley, W. N., gases in rocks___ 224 

reduction of sulphates. ___ 116 

Hartley, W.. N., and Ramage, I-L, distribution of rare elements_______ 26, 451, 558 

Hartsalz _______________ 179,180 

Harzose __________________ 380, 382 

Hasshagen, , water analysis__ 130 

Hasslinger, R.von, artificial diamond- 263 

Hastings, J. B., gold ores__ ___ 554 

Hastingsite ________1______ 322 

I-Iatchettite________________ 624' 

Hauenschild, G., predazzite.____ 489 

Hauer, K. von, analysis of water_ 132 

Haiiynite_______________ 309-311 

Haiiynophyre ___________.__ 378 

Haushofer, dolomite and magnesite_ 484 

Hausmann, J. See Zaloziecki and

Hausmann.

Hausmann, J,. F. L., wulfenite___ 589 

Hausmannite ____ ________ 455

Hautefeuille, P., synthesis of enstatite ___________ 312 

syntheses of feldspars________ 302

of greenockite and wurtzite 578 

of leucite___________ 305 

of nephelite ________ 308 

of olivine___________ 325 

of perofskite_________ 287 

of quartz and trldymite__ 297 

of rutlle, brookite,. and anatase ___________ 289 

titanite __________.._ 288 

vanadinite __________ 590 

See also Troost and Hautefeiiille. . Hautefeuille, P., and Margottet, .T., 

synthesis of quartz and . 

trldymite________ 297 

synthesis of staurolite (?) __ 344 

Hautefeuille, P., and Perrey, A., 

crystallization of titanic oxide_______. 289 

synthesis of beryl______.__ 347 

of corundum_________ 275 

of zircon ____________ 291

Hautefeuille, P., and Saint-Gilles, 

L. P. de, synthesis of 

mica__________ 328

Page.

Hawes, G. W., alteration of granite. 532 

analyses by ____________ 643 

chloritlzation ____________ 518

native iron ______________ 267 

Hawes, G. W., and W right, A. -W.,

gases in quartz__ _ 224 

Hawkins, J. D. See lies and Hawkins.

Haworth, E., petroleum _______ 639 

zinc deposits______________583 

Haworth, B., and Bennett, J., native

copper ______ _ 566 

I-Iayes, A. A., distribution of vanadium __________ 611 

sodium iodate in Chilean nitre__ 208 

South American borates___ 201 

Hayes, C. W., alunogen deposits _ 211 

bauxite ______________ 420,421 

corrosion of quartz ____. 300, 406 

iron ores ___ _ 453 

phosphatic sandstones__ _ 461 

phosphorite.___ ___ 449 

Hayes, C. W., and Bckel, E. C., iron

ores _______ 453 

Hayes, C. W., and Kennedy, W.,

Texas petroleum. _ 622 

Hayes, C. W., and Ulrich, E. 0.,

phosphorite __ 449 

Hayes River, analysis of water-___ 71 

Haywood, J. K., analysis by_____ 152 

Haywood, J. K., and Smith, B. H.,

analyses cited____ 144, 154 

Headden, W. P., action of water on

orthoclase ________ 406

analyses of river waters. 55, 58, 59, 68

anthracite ._____________ 656

barytic sinter __________ 160, 498

cubanite _______________ 567

stannite _ __________ _ 591

Heath, G. L., cited __________ 60

Heazlewoodite _'________ ___ 599

Hoberdey, P., melilite and gehlenlte

in slags ______ _ 333

wollastonite in slags___ _ 313

lledburg, E., zinc deposits__ _ 583

Heddle, M. F., analysis by____ _ 441

1-Iedenbergite ______________ _ 314

Hedrumite________________ 376

Heider, A., water analysis___ _ 130

Heintzite________________ 180, 202

Helium, distribution _________ 16, 615

in natural gas_- ___ 621

in spring waters- ___ 140

Hell, C., fichtclite__ ________ 648

Hell, C., and Hiigele, C., artificial

paraffin __________ 620

Helmhacker, R., chromite deposits_ 605

Hematite_______________ 284, 286

melting point_________ 240

Hempel, W., melting points of minerals_______ 239, 240, 274 

oxygen of the atmosphere 39 

Henriet, H., formaldehyde In atmosphere _______ 41 

Heraeus, W. C., melting points of

shales and clays. _ 239
688 INDEX.

Page.

Hercynite ____________ 279, 280, 281 

Herderite ________________ 348 

Heron Lake, analysis of water___ 66 

Heronite _______________ 307, 379 

Hess, F. L., and Graton, L. C., distribution of tin____ 591 

Hess, W. H., cave nitrates_____ 205 

Hessite _________________ 562 

Hessose _______________ 383, 385 

Heterogenite _ 602 

Heubachite _______________ 602 

Heulandite ________________ 349 

Heumite __________j. ________ 376

Heusler, F., formation of hydrocarbons-_________ 635

Heusser, C., and Claraz, G., Brazilian diamonds____ 265 

Hewett, F., vanadium ores_____ 613 

Heyward, B. H., tallow clays____ 583 

Hezner, L., amphibolite-_______ 510 

eclogite _______________ 517 

Hibschite ________________ 345 

Hicks, H., phosphatic fossils____ 448 

Hidden, W. E., Llano County minerals___________ 618 

sperrylite _____________ 610 

xenotime in granite______ 294 

See also Judd and Hidden. 

Hidden, W. E., and Mackintosh,

J. B., gadolinite, etc_ 618 

Hidden, W. E., and Pratt, J. H.,

sperrylite ________ 610 

Hidden, W. E., and Warren, C. H.,

yttrocrasite ______ 618 

Hiddenite ________________ 315 

Hieratite __________________ 221 

Highwood River, analysis of water_ 72 

Highwoodose ___ ___ _ 370 

Hikutaia Spring, analysis_____ 149 

Hilgard, E. W., analyses hy__ 70,124, 190 

arid and humid soils compared 415 416 

carbonates as solvents of silica- 408 

disintegration of rocks_____ 415 

origin of alkaline carbonates in

soil________ 166, 194, 195 

soils. ___ _____________ 431

Hill, B. F., Terlingua mines____ 573 

Hill, J. B., and MacAHster, D. A.,

Cornish tin ores____ 592

Hill, R. T., Terlingua mjnes_____ 573

Texas petroleum __- _________ 622

HUlebrand, W. F., analyses by_ 146,148,

149, 317, 366, 367, 368, 869, 370,

372, 373, 374, 375, 376, 379, 380,

S81, 382, 383, 384, 385, 386, 387,

388, 389, 390, 391, 392, 393, 432,

438, 455, 468, 469, 489, 492, 510,

530, 531, 535, 546, 555, 614, 615

copper arsenates_________ 570

distribution of vanadium__ 611, 612

heavy metals in rocks_^____ 543

kleinite _ _ _ _ ___________ 573

patronite ______________ 613 

rare earth minerals_______ 618 

roscoellte ______________ 613

Page.

Hillebrand, W. F., zinc-bearing clay_ 583 

See also Cross and Hillebrand.

Hillebrand, W. F., and Ransome, F.

L., carnotite ____ 615

Hillebrand, W. F., and Schaller, W.

T., Terlingua minerals- 573 

See also Schaller and Hillebrand.

Hinde, G. J., chert and flint____ 465

Hiortdahl, T., synthesis of jaipurite_ 600

Hiortdahlite_______________ 317

Hitchcock, C. H., albertite______ 625 

steatite _ _ _ _ ____________ 522

Hobbs, W. H., allanite nnd epidote__ 341 

secondary galena___ ____ 585 

tungsten deposit________ 607 ^

Hodges, R. S., analysis of water__ 63

Hb'gbom, cited by Arrhenius____ 44 

dolomitization _ _ _ _ _ _____ 485-486

Hoernes, R. See Doelter and 

Hoernes.

Hoff. See Van't Hoff.

Hoffmann, E. W., solubility of minerals____________ 404

Hoffmann, G. C., baddeckite_____ 326 

native iron____________ 270 

native platinum__________ 608 

souesite ___ 26'J

Hoffman, L., iron ores _______ 494

Hoffmann, R., synthesis of nephelite 308

Hofman, H. O., eutectics in slags__ 248

Hofmann, J. F., formation of coal_ 665. 66.6

Hofmann-Bang, 0., rivers of Sweden.

Hoitsema, S. See Bem'melen, J. M., 

van, etc.

Holland, P., and Dickson, E., decoui- < 

position of diabase __ 413

Holland, T. H., barite__________ 500 

bauxite ______________ 422 

corundum rock_________ 277 

disintegration of rocks--___ 407

graphite in syenite______ 267

laterite_ _ ______________ 417

Hollick, A. See Kemp and Hollick. 

Holmium_________________ 16 \ 

Holmquist, P. J., synthesis of perofskite___________ 287 

Holway, R. S., eclogite________ 517 

Hood, , analysis by________ 603 

Hopeite ____________ _ 580 

Hopkins, A. T., chlorine maps____ 47 

Hopkins, T. C., limestones______ 478 

Hopmann, H., water analysis____ 133 

Hoppe-Seyler, F., formation of marsh 4-

gas___________ 633, 634 

synthesis of dolomite_ ____ 482 

Hornblende____________ 319-322, 508 

melting point ____________ 240 

Hornblendite _ _ _____________ 390 

Horner, L., silt_____________ 428 

Hornstein, F. F., native iron_____ 267 

Hornung, F., origin of petroleum__ 635 

Hornung, M., analysis of red mud_ 437 a 

Hornung, T. See Duparc and Hornung.

Horowitz, .T. See Dunin-Wasowicz. 

Horsford, E. W., cited_________ 63
INDEX. 689

Page.

Horsfordite __ '_ _ 567 

Hortonoltte ________________ 324 

Hosklns, A. P., glauconlte_______ 441 

Hovey, E. 0., artesian well at Key

cordierite gneiss__s_______ 339

West __________ 488

_Ho\v, H., borates of Nova Scotia__ 203

Howard, C. C., natural gas______ 621

Howard, C. D., analyses by 66,620

Howe, ,T. L., 'and Campbell, H. D.,

on Chichen-Kanab __ 126

Ilowlite _ __ _____________ 203 

Huantajayite _ _ __ 564 

Hiibnerite ______________^-_ 606, 607 

Ftudleston, W. IT., phosphntlc fossils__________ 448 

Hudson, E. ,T. See Mabery and

Hudson.

Hudson River, analyses of water 62, 83 

Hughes, G., phosphate rock_____ 444 

Hull, E., and Hardman, E. T.,

chert _________ 464

I-Iuraboldt and Gay Lussac, cited__ 45 

Humboldt Lake, analysis of water. 123, 136 

Humboldt River, analysis of water 123 

I-Iumboldt salt well, analysis 141 

Humboldtine_______________ 644 

'Kume, W. F., loess__________ 433 

Humphreys, A. A., and Abbot, H. L., 

sediment of Mississippi 

River __________ 420 

Humphreys, W. .T., rare earths in

fluorite__________ 274 

Humus acids __________ 409, 646, 651 

Hundeshagen, L., platinum in wollastonite__________- 610

Hungary, salt and warm lakes of 133

Hunt, A. E., bauxite_________ 421

Hunt, T. S., abundance of petroleum 640

alteration of slderite_____ 491

analysis by 61,144, 155

cosmlcal atmosphere__ 49

formation of dolomite____ 481, 485

on atmospheric carbon dioxide_ 43

origin of alkaline carbonates 194

primeval ocean_______ ___ 108

salt and gypsum________ 183, 184 

sedimentation ___________ 429 

serpentine _____________ 521 

See also Logan and Hunt. 

Hunt, W. P. Sec Krau's and Hunt. 

Hunter, M., analysis by_______ 379

Hunter, M., and Rosenbusch, H.,

monchiquite___ ___ 378 

Ihmtilite _________________ 560 

Hunyadi Janos, origin of water__ 167 

Hurlbut, E. B., analysis by____ 376 

Huron, Lake, analysis, of water___ 61 

Hurst, L. F. See Cameron and Hurst. 

Hussak, E., associates of diamond-- 265 

chalmersite ________ ___ 567

leucite pseudomorphs ___ ___ 307 

native iron ___________ 268 

palladium gold __________ 555 

perofskite-magnetite rock___ 288

14399 Bull. .330 08 44

Page.

Hussak, E., platinum and palladium___________ 608 

primary iolite____ _ 339 

synthesis of wollastonite __ 313 

See also Doelter and Hussak. 

Hussak, E., and Prior, G. T., derbylite, etc.________ 598 

Hussak, E., and Reitinger, J., monazite sand ______ 294 

Tlutchings, W. M., minerals in sand_ 427 

ottrelite__ _____ ___ 529 

willemite in slag________ 581 

Hutchins, W. M., apatite in slag__ 293 

clays and shales__________ 469 

Hutchinson, , cited______ 46 

Hutchinson, A., Meigen's reaction_ 473 

See also Cundell and Hutchinson.

Hutchinson, brine, analysis of 141 

Hutton, R. S. See I'ring and Hutton. 

Hyalite _____________'___ 295

Hyalophane ____________ 300 

Hyalotekite ______________ 590 

Hydrargillite. See Gibbsite. 

Hydroboracite ___________ 180, 202 

Hydrocarbons ____________ 619-641 

in lava______________ 230, 231 

Hydrogen, distribution________ 16

in atmosphere _:_________ 40, 41 

Hydrogen dioxide in atmosphere __ 40 

Hydronephelite __ _ _ -_ 349 

Hydrozincite _______-____ 580 

Hypersthene_____________ 311, 312

Iceland, analysis of geyser water

from_____________ 153

Iddings, J. P., consanguinity of

rocks __________ 253 

fayalite in rhyolite_______ 325 

magmatic differentiation __ 245, 254 

order of igneous eruptions___ 256 

quartz -basalt__________ 299 

rock diagrams__________ 400. 

See also Barns and Iddings. 

Iddings, J. P., and Cross, W., primary allanite_____ 341 

Iddings, J. P., and Penlield, S. L.,

fayalite in rhyolite__ 325 

Idocrase. See Vesuvianite.- 

Idrialite__________.._____ 576, 625 

Igelstrom, L. J., molybdenum in

-hematite________ 286 

Igneous rocks____________ 352-400

average composition _____ 24-27 

classification of__,_____ 353-365 

Ihlseng, M. C., phosphate rock___ 451 

Ijolite ____________..____ 375, 376 

lies, M. W., and Hawking, J. D., 

precipitated zinc sulphide _____:______ 579 

Iletsk salt lake, analysis of water. 132,

134

Illiacus, A. See Ramsay and Illiacus.
690 INDEX.

Page.

Illinois River, chlorine in____'_ 85 

Ilmenite ______________'__ 286, 287 

Ilmenite norite_____________ 393 

Ilosvay, L. von., water analysis__ 80 

Illyes Lake, analysis of water__ 132, 134 

Indalself, analysis of water_____ 81 

Indium, distribution __ _ 10 

Infusorial earth __ _ _ 460 

Ingalls, W. R., tin deposits_____ 593 

Ingol, Lake_______________ 81' 

Inostranzeff, A., native platinum__ 609

schungite _____________ 657 

d'lnvilliers, E. V., phosphate rock_ 444 

Iodine, distribution- ________ 17

in sea water____________ 91

in spring water-_________ 142

lolite __________________ 339-340 

Ionian Sea _______________ 94 

Iowa, river waters of________ 04 

Ippen, J. A., amphibolite______ 510

synthesis of cinnabar______ 575 

Iridium__1__________ 18, 607^611 

Iridosmine _______________ 608, 609 

Irish Sea, analysis of water___ ___ 95 

Iron, distribution _ . 17

hydroxides of__ _ _ 451-454 

> in sea water_____________ 92

: meteoric, chlorides in______ 109

native ____________ 109, 267-271 

'< . nitride ________________ 222

occlusion of gases by____ 234 

Iron bacteria_____________ 452 

Iron ore__ 282-286, 417, 451-454, 490-494

titaniferons____________ 393 

Irvine, R. See Murray, Sir J. 

Irvine, R., and Gibson, J., manganese nodules______ 103 

Irvine, R., and Young, G., solubility

of calcium carbonate_ 98 

Irving, J. D., tin deposits______ 594 

living, J. D., and Emmons, S. P.,

tungsten ores__ ___ 607 

Irving, R. D., native copper____ 565

qnartzite __________'___ 524 

Irving, R. D., and Van Hise, C. R.,

chert __________ 466

enlargement of quartz grains - 460 

Iser River, analyses of water--_-_ 77 

'Isochlors _______________ 47

Issyk-Kul, analysis of water___ 132, 136 

Istrati, C. I., Roumanian salt- 184 

Itabirite _________________ 525 

Itacolumite ________________ 265

J.

.Taccard, A., origin of petroleum 639 

Jackman, W. F., cited_________ 60 

Jackson, D. D., cited___________ 47

.Tacobsen, 0., analyses of dissolved

air ____________ 111

analysis of peat __ 046

resins in peat __ 048

Jaczewski, L., origin of graphite__ 267

Jadeite _____ 315-316

Jager, F. M., analysis by 454

Page.

Jaffa, M. E., alkaline carbonates___ 194 

Jaggar, T. A., and Palache, C., zoisite rock ________ 513

Jahn, J. J., origin of petroleum___ 635 

Jaipurite __________________ 599, 600

James River, analyses of water___ 63, 83 

Jamesonite ______________ 585, 586 

Jamieson, G. S., nickel-irons-____!_ 270

See also Penfield and Jamieson. 

Janda, , uranium ores_'____ 613 

Janeirose _______________ 376

Jannasch, P., and Calb, G., composition of tourmaline__- 346 

Jannasch, P., and Weingarten, P.,

 vesuvianite_______ 337 

Jannetaz, E., formation of anglesitc- 5SS 

Janssen. J., volcanic gases_____ 220 

Jaquet, J. B., platinum in ironstone- 610

serpentine ____________ 348, 520 

Jarman, J. L., analysis by______ 455 

Jasper__________________ 294 

Joffersonite__________:____ 314, 580 

Jenkins, , analysis by______ 456 

Jenney, W. P., artificial grah-amite__ 626

recent blende.'__________ 579

zinc deposits___________ 583 

Jennings, E. P., magmatic iron ores- 284 

Jenssen, H. S., copper in andesite__ 544 

Jordan, D. S. See Bone and Jordan. 

Jeremeef, P., chalcopyrite and chalcosite__________ 569

pseudomorphous garnet_____ 337

pseudomorphs after olivine___ 325 

Jorvis, W. P., Tuscan fumaroles___ 204 

Jet __________________:_ 649, 661 

Joannis, A., fusion of limestone___ 478 

Johansson, H. E., eutecties_ _ 249, 356 

John, C. von, humus acid in coal_ 651

kainite and carnallite______ 181 

Johns, C., transition point of quartz 297 

Johnson, H. S., water analyses cited 79 

Johnson, L. C., Florida phosphates- 444 

Johnston, R. A. A., analysis by___ 281 

Jbhnston-Lavis, H. J., absorption of

rocks by magmas___ 255

Vesuvian sublimates______ 221 

Johnstone, A., action of water on

micas__________ 331

solubility of minerals___:_ 102, 404

Johnstrup, F., cryolite____'. ____ 274

Joly, J., age of the earth__ 108, 109, 110

meldometer ____________ 239

order of deposition of minerals- 252

radium and geology_______- 260 .

sedimentation ___________ 429

sublimation of enstatite_____ 224

volume of oceanic salts____ 23

Jones, E. J., barite nodules____ 106

Jones, T. R., chert__________ 464

Jonesville acid water, analysis___ 155

Jordan River, analysis of water__ 129

Jordan River (Utah), analysis of

water ___________ 120 

Jordanite __'_______________ 585 

Jorissen, A., vanadium in delvauxite- 612 

Joseite__________-__-- _- 595
INDEX. 691

Page.

.Tosephinite ______________ 269, 270 

.Toukowsky, E.. eclogite________ 517 

.Town, L., synthesis of selenite____ 495 

Judd, .T. W., alteration of plagioclase to scapolite___ 304 

atoll of Funafuti________ 487 

origin of scapolite________ 338 

scapolite rock_________ 514

.Tucld, J. W., and Brown, C. R.,

Burmese comndum_l_ 277 

.Tudd, .T. W., and Hidden, W. E.,

ruby ___________ 278 

Judge, .T. F., and Fennel, A. C., analysis by________ 142 

Judlthose _________________ 373 

 Tukes Brown, A. .T. See I-Iarrison

and Jukes Brown. 

Julien, A. A., alteration of spodumene _________ 315 

crenic acid in waters______ 83 

decomposition of pyrite____ 273

geological effects of humus

acids ..__________ 409 

phosphate rock______ ___ 444

solution of silica by organic

matter __:_______ 465 

Juvenile waters_____________ 168

K.

Kahlenberg, L., and Lincoln, A. T.,

hydrolysis of silicates. 151 

Kahlenberg, L., and Schreiner, 0.,

borate ions ______ 153

Kainite __________ 178, 179, 180,181

Kaiser, E., alteration of basalt__ 424

decomposition of rocks_____ 411

Kaleczinzky, A., water analysis.- 132, 133 

Kalgoorlite _________________ 555 

Kaliophilite _____________ 307, 308 

Kallerudose _______________ 369 

Kallilite _________________ 599 

Kalmann, W., and Glaser, M., analysis by________, 143, 146 

Kanab Creek, analysis of water from

near _________ 144

Kansas River, analysis of water_ 68 

Kaolin _______________ 416, 418, 423 

Kaolinite _____________ 349, 416, 527 

Kapoiiran. analysis of water_____ 143

Karaboghaz, Gulf__________ 127,136 

Karlsbrunn, analysis of water from. 149 

Karlsdorf waters, analysis______ 145

Karstens, K., volume of the ocean 22 

Kiisarnowski, I-J. See Wohler and

Kasarnowski.

Kastle, J. H., Frazer, J. C. W., and 

Sullivan, G., phosphatic chert______- 466 

Katamorpliism. zone of________ 502 

Katwee salt lake, analysis of water,

133,137 

Katzer, F., analyses of Amazon

water ____ -'._____ 73 

analyses of sea water cited_ 94

Page.

Katzer, F., mercury deposits _ 577 

Kauer, A., analysis by________ 146 

Kaufmann, F. G., dopplerite_____ 647

Kay, G. F., nickel ores__________ 602

Kayser. R., sulphur in petroleum._ (>1!4 

Kedabekase________________ 389 

Kehoeite _______________ 580

Keith, A., zinc deposits________ 583 

Keller, G., formation of limonitc__ 490 

Keller, H. F., and Lane, A. C., chloritoid ___________ 327 

Kelly, A.., conchite___________ 473 

Kelvin, Lord, effect of pressure on

fusibility _______ 238 

primitive atmosphere-_____ 50

Kelyphite ________________ 336

Kcmp, J. F., bornite in pegmatite- 568, 569

Franklin zinc ores__________ 584

gneiss defined________ 534

gravitative differentiation in

magmas 257

magm'atic magnetite_________ 284

metamorphosed dolomite____ 539 

molybdenite in pegmatite _ _ 273 

nickel ores____________ 601

ore deposits __________ 541, 54.8 

platinum ores__ 271, 608, 609, 610, 611 

relative abundance of elements. 26 

secondary enrichment______ 552 

tellurides ____________ 555

Kemp, J. F., and Hollick, A., limestone __________ 539

Kempton, C. W., tin deposits-----_ 593

Kendall, P. F., calcite and aragonite

in shells ________ 474 

Kennedy, W., See Hayes and Kennedy. 

Kenngott, A,, alkaline reaction of

minerals _______ 403

composition of tourmaline___ 346 

Kenrick, F. B. Sec Van't Hoff,

' Kenrick, and Dawson. 

Kentallenose_____________ 383, 384 

Kentrolite _____________ 590

Kentucky River, analysis of water__ 66 

Kermesite _______________ 595, 597 

Kern-theorie ______________ 358 

Kerosene shale_____________ 637 

Kersantite_______________ 371, 384 

Kettner, C. H., analysis by______ 454 

Keyes, C. R., linnajite____ __..__ (501 

loess __________________ 433

ore deposits ___________ 541

primary epidote _________ 341 

recent blende __________ 579

Kieserite_______ 178, 179, 180, 181,182 

Kikucbi, , occurrence of iolite__ 340 

Kilbrickenite _______________ 585 

Kimball, J. P., grahamite_______ 625 

iron ores_____________ 453, 490

Kimberlite _______________ 265

Kinahan, G. H., bauxite______ 420 

Kinch, E., sodium chloride in rain_ 47 

King, C., internal temperature of the

earth____________ 238 

King, F. P., Georgia corundum___ 278
692 INDEX.

Page.

Kingsbury, J. T., waters of Utah___ 119 

Kirk, M. P., and Malcolmson, J. W.,

Terlingua minerals__ 573 

Kisil-Kul, analysis of water____ 131,135 

saline deposits _ ___ _ 187 

Kitchell, W., marl___________ 472 

Kitchin, E. S., and Winterson, W. G., 

argon and helium in 

minerals.-___ ___ 225 

Klaprotholite_________________ 570

Klarelf, analysis of water 81 

Kleinite___'. ______________ 573

Kiement, C., analyses by_________ 105, 530

formation of dolomite_____ 482

laterite_______________ 418

origin of petroleum_______ 634

Klementite________________ 331

Klemm, "G., minerals in. sandstone- 462

Klobbie, E. A., analysis by__ _ 454

See also Beminelen, J. M. van,

etc.

Knebelite _______:________ 3.24 

Knight, C. W., analcite trachyte__ 307

See also Campbell and Knight. 

Knight, H. G., water analyses___ 70,125 

Knight, W. C., platinum in covellite. 611 

Knisely, A. L., water analyses.___ 70 

Knop, A., enlargement of quartz

grains__________ 460 

Knoxvillite________________ 604 

Kobellite_________________ 585 

Koch, A., celestite and barite_____ 498 

Kobrich, bauxite_____________ 420 

Koene, C. J., primitive atmosphere_ 50 

Koenig, A., genesis of diamond___ 265 

Koenig, G. A., synthesis of domeykite____________~ 567 

Koenig, G. A., and Foote, A. E., diamonds in meteorite--- 264 

Konig, T., and Pfordten, O. von der,

ilmenite________ 286" 

Kb'nigsberger, J., and Miiller, W. J., 

synthesis of quartz 

and tridymite_____ 296 

Kiinlite __________________ 624 

Kiittigite _______________ 580 

Koettstorfer, J., iodine in sea water- 91 

Kohlmann, W., associates of cassiterite_____________ 291 

Kohlrausch,' F., hydrolysis of silicates __________ 152 

Koko-Nor, analysis of water___ 130, 137 

Kolenko, B., hornblende pseudomorphs_______._ 321, 326 

Kolderup, C. F., analysis by _____ 393 

Kolkwitz, R., and Ehrlich, F., on the

Elbe ___________ 78 

Kolotoff, S., analysis of sea water__ 95 

Koninck, L. L., de, synthesis of cinnabar__________ 575 

Koninckite.________________ 443 

Kornerupine _____________ 316, 529 

Kosmann, H. B., silver halides 564 

Koto, B., chloritoid rock_______ 529 

glaucophane rocks. __ ___ 509 

piedmontite - - 341

Page. 

Kovaf, J., kyanite in limestone____ 344

Kramer, G., and Bb'ttcher, W., origin .

of petroleum______ 634 

Kramer, G., and Spilker, A., origin

of petroleum__:____ 638 

Kraus, E. H., celestite__ ______ 497 

Kraus, E. H., and Hunt, W. F., celestite__________ 497 

Kraut, K., diffusion of cobalt and

nickel __________ 599 

Kremersite _______._______ 221 

Krennerite ________________ 555 

Kreusler, U., oxygen of the atmosphere_"_________" 39 

Krogh, A., annual consumption of

coal ___________ 42

oceanic carbonic acid____ 112, 115

on air from Greenland_____ 42

Kruft, L., phosphorite ________ 447

Krugite __________________ 178

Krypton _________________ 17,38

Kryptotile __________________ 527

Ktypeite ________________ 473

Kiimmel, H. B., clays ________ 431

peat_________'.___________ 645

Kuhlmann, F., synthesis of cerargyrite ___________ 564 

Kulaite __________________ 386 

Kultascheff, 'N. V., fusion of mixed

silicates________ 246, 247 

Kunz, G. F., Montana corundum__ 278 

Kunz, G. F., .and Washington, H. S.,

Arkansas diamonds__ 265 

Kunzite _ ______________ 315 

Kurnakoff, N. S., on Karaboghaz_ 127 

Kurtz, C. M., analyses by_____ 197 

Kusnetsoff, S., on Karaboghaz___ 127 

Kuss, H., mercury deposits_____ 577 

Kvassay, E. von, origin of alkaline

carbonates_______ 194

Kyanite _________ 343, 344, 527, 528

Kyanite schist _____________ 530

Kyle, J. J., Argentine borates___ 202

vanadium in lignite __.____ 612

water analyses__________ 74

Kyschtymase ______ 393

Kyschtymite_____________ 277, 393

L.

Laa bitter spring, analysis_____ L 146 

Laach, Lake, analysis of water__ 132, 136 

Labradorite _______________ 300 

Laby, T. H. See Mawson and Laby. 

Lachat, , celestite____1_ 498 

Lachaud and Lepierre, lead chromates__________ 589 

Lacroix, A., absorption of limestone by granite __ 255 

allanite and epidote.______^ 341 

' alteration of bronze.______ 571 

alteration of hornblende to

augite___________ 321 

alteration of. serpentine___ 348,521 

berthierine _ ___________ 494 

dumortierite in gneiss 346
INDEX. 693

Page.

Lacroix, A., eclogite rocks______ 516 

formation of zeolites______ 351 

glauconite ______________ 440 

ktypeite _______________ 473

occurrence of lawsonite_____ 345 

phosphatized andesite_____ 444 

recent cerussite ________ 587 

scapolite rocks____-____ 338, 515 

tridyinite at Mont Pele"e____ 298 

volcanic sublimates______ 221, 222 

See also Michel L6vy and

Lacroix. 

Lacroix, A., and Baret, C., wernerite rock__ __ 515 

Lacu Sarat, analysis of water_ 132, 135 

saline deposits_____ _ 187 

Laczczynski, , analysis of chromite__________ 282,604 

Ladd, G. E., clays_____ - 431 

Ladureau, A., sulphur in atmosphere _ 41 

Lagonite ____________ _ 196 

Lagorio, A., eutectics_______ 356 

formation of leucite_________ 306

fusibility and solubility distinguished _ r_______1 253 

glass-base __ _ 254 

pyrogenic corundum _ 277 

solubility of minerals in. mag*

mas_________ 255 

Lagoriolite ________________ 335

Lahille, F., analysis of sea water__ 94 

Lahontan, Lake________ 118, 121-124 

La Junta artesian well, analysis 149 

Lake, P., laterite_____________ 418

Lampadite ___________ 455, 456, 571

Lamprophyre ____ 371, 372

Lanarkite ____________-__ 588

 Lane, A. C., eutectics_____ 249,356

Lane, A. C., magmatic gases 234

mine waters _,_ _ 546

native, copper _ _ 565

the ocean ____ 97

waters of Michigan__ 168 

See also Keller and Lane. 

Lane, A. C., and Sharpless, F. F.,

griinerite_____ 319 

Langbeinite___________ 178,189, 182 

Lansfordite _____________- 483 

Lanthanum _________ _ 17 

Lapis lazuli_____________ 309 

Lapparent, A. de, distribution of

solfataras _____ 167

Laramie lakes, analyses of water. 126,135

Laramie River, analyses of water 67

Larderellite _____________ 196

Lartet, L., on Dead Sea_______ 129

Lasaulx, A. von, alteration of rutile_ 286

kelyphite ______________ 336

sulphur deposits _ _ 496

Lasne, H., phosphorite_ 451

Laspeyres, H., olivine as a furnace

product _______ 324

sericite ______1_______ 510

Lassenose _______________ 367, 381

Lateral secretion__________ 542

Laterite _____________ 417-424, 456

Page.

Latite __.______________ 380, 381 

Latschinoff, P. See ErofSef and

 Latschinoff.

Lattermann, G., barytic slnter___ 498, 499 

Lattimore, S. A., analysis by___ 188 

Laubanite ________________ 350 

Laumontite__'_____________ 349, 350

Launay, L. de, average composition

of igneous rock____ 25

magmatic waters_________ 547

ore deposits____________ 541

Laur, F., bauxite____________ 419

gold and silver in Triasslc

rocks __________ 553 

Laurdalite_______________ 376 

Laurdalose ______________ 372, 373 

Laurionite _1__^__________ 587 

Laurite _________________ 607 

Laurvikose _____________ 370 

Lautarite ..________________ 207 

Lavenite ________________ 317

Lawrenceite _____________ 109 

Lawsoo, A. C., chert__________ 465 

corundum rock__________ 277 

See also Adams and Lawson. 

Lawson, A. C., and Palache, C.,

chert___________ 465

Lawsonite ______ ___ 345

Lead, distribution_________.._ 17

occurrence in a coral______ 93

ores of__ _'_________ 584-590

Leadhillite.______ ________ 588

Lebedintzeff, A., water analyses_ 127, 128

Leblanc, F. See Deville and Leblanc.

Lechartler, G., synthesis of mimetlte 590

syntheses of olivine_______ 324

synthesis of pyroxene______ 314

Le Chatelier, H., Algerian alkaline

deposits_________ 194

clay substances in marl___ 480 

constitution of clay silicates._ 416 

formation of granite_____ 366 

fusion of limestone_______ 478

thermo-couple __________ 239 

Leckie, .T. S., nickel ores_______ 603 

Le Conte, J., Nevada borates___... 199 

I.e Conte, J., and Rising, W. B., mercury deposits____... 577 

Leddin, . See Blum. 

Ledoux, A. R., nickel ores____ 602 

Leduc, A., hydrogen in atmosphere_ 41 

Lee, G. W. See Collet and Lee. 

Lefort, J., analysis by______:_ 156

Lehder, J., phosphatic nodules_..-- 451 

Lehmann, B., sericitic rocks_!__ 511 

Lehmann, T. See Engler and Lehmann.

Leibius, A., gold-____________ 554 

Leighton, M. O., analysis of water_ 61 

normal and polluted waters__ 86 

Leith, C. K., actinolite-magnetite

schist__________ 319

glauconite and greenalite__ 440,

492, 493

origin of magnetite. ______ 284
694 INDEX.

Page.

Lekene _________________ 625, 638 

I.eman, Lac, analysis of water_.._ 76 

Lemberg, J., alterations of feldspar- 304 

, alteration of spodumene and

jadeite________._ 316 

of topaz____________ 342 

artificial cancrinite __'_____ 310 

chlorite pseudomorphs____ 332, 336 

composition of sodalite_____ 309 

decomposition of rocks_____ 411 

double decompositions in silicates ________ 425

epidotization ___________ 516 

fusion of limestone_______ 477

kaliophilite and nephelite__'_ 308 

leucite and analcite_____ 304, 305 

predazzite ____________ 489, 490 

primitive atmosphere____._ 50 

reactions with andalusite and

kyanite _________ 344

with gehlinite_________ 334

serpentine ____________ 519, 520

syntheses of zeolites_______ 350

tests for calcite and dolomite_ 485

Lemiere, L., formation of coal____ 666

LeneCek, 0., predazzite _______ 489

Lemetayer, P., water analysis____ 74

LenarCic', J., formation of augite__ 317

formation of magnetite______ 283

of nephelite_____: ____ 309'

fusion of mineral mixtures__ 252

recrystallization of albite____ 302

Lengenbachite ____________ 585

Lengyel, B. yon', .analysis of water_ 132 

Lenher, V., gold telluride______ 556,558 

solution of gold________ 558 

See also Hall and Lenher. 

Lenicque, H., carbide theory of volcanism ___ __ 230

origin of petroleum_______ 632

primitive atmosphere______ 51

Lenk, H., augite-scapolite rock__ 339

Lenz, O., itabirite___________ 525

Leonard, A. G., gas well_______ 633

zinc deposits_ __ __ 583

Leonite ________________ 178, 179

Lepidolite ____________ 326-329, 593

Lepidomelane _________ __ 327

Lepierre, C., fluorine in spring

waters-______-. 149

Lepsius, B., composition of dissolved

air ____________ 402 

Lepsius, R., glaucophane schists_ 509 

Lesley, J. P., grahamite_ ___ 625 

Lc-squereux, L., origin of petroleum- 637 

Letheby, I-L, water analyses 82 

Letts, E. A., and Blake, R. P., carbon dioxide in air_ 42 

Leube, G., dolomite_________ 485 

Leucite ________________ 304-306 

melting point___________ 240 

Leucite basalt_______ 386 

Leucite rocks____.._______ 376-378 

Leucite syenite____________ 376 

Loucitite _______..___ 376 

Leucopyrite 595

Page.

Lcucoxene ________________ 287 

Leuk, analysis of water_______ . 146 

Levat, E. D., gold and silver in diabase :____________ 544 

Lovat, D., nickel ores_________ 603 

phosphate rock_____._____ 449 

Leverett, F., loess___________ 433 

Loverrierite _____________ 527

Levi, M. G., radioactivity of lava__ 259 

Levy. See Michel-Levy; Fouque"

and Michel-Le'vy. 

Levy, A., nitrogen compounds in

rain ___________ 46 

Levynite_--_______________ 350

Lewin, L. See Schweinfurth and

Lewin.

Lewis, I-L C., origin of diamond__ 264 

Lewis, J. V., North Carolina corundum____________ 278 

See also Pratt and Lewis. 

Lewisite--________________ 598

Lewy, H., analysis by_________ 156 

Lherzolite- _ _______________ 390 

Libbey, W., volcanic gases______ 220 

Lieber, 0. M., itabirite________ 525 

Liebert, I-L, uranium in coal_____ 616 

Liebrich, A., bauxite________ 42JL, 424 

Lienau, H., bauxite___________: 422 

Lignin ____________________ 643 

Lignite-_________________ 648-653

Lignocellulose_______________ 643

Lignone_ _________________ 643

Lillianite-----_____________ 586

Limburgite, fusibility!_________ 242 

Limburgose- __ _____________ 386

Limestone_________ 470-490, 535-540

average composition _______ 27, 30

formation of ____________ 100

Limnite _________________ 451

Limonite_________ 451-454, 490-492

Linarite __________________ 588

Linck, G., associates of spinel- _ 280

oolite ________________ 474

orthoclase in dolomite_____ . 538

solubility of calcium carbonate. 99

troilite _ _ _ _ ____________ 271

Lincoln, A. T. See Kahlenberg, L. 

Lincoln, F. C., magmatic gases 237 

Lindemann, B., minerals in limestone ___________ 539 

Lindgren, W., analcite in rocks 378 

brochantite_____________ 571 

chalcocite__-___________ 569 

magmatic magnetite __ < 284 

magmatic waters'as vein fillers- 168 

monazite sand __ _ 294 

native copper __________ 565 

ore deposits- __ __ - 548 

orthoclase as a gangue mineral- 303 

pseudomorphous galena 585 

sericite and calcite _____ 512

sodalite syenite _______ 306, 311 

stibnite in sinter ______ 597 

tin deposits- __ 593 

tungsten ores___ 607 

Linnseite _________:___ 599, 600, 601
INDEX. 695

Page. 

Llparite ________.. 366

Liparose __________ 367, 368

Lipp, A., analysis by _ 143

Lisboa, A., monazite sand____ 294

Litchfieldite ______________ 376

Lithium, distribution_________ 17

in sea water____ _ _ 92

Lithosphere, average composition 23-33

volume of_____________ 22

Little, G., lead selenide 584

Liveing, G. D., cited__________ 41

Liversidge, A., analyses by____ 144, 603

bog-iron ore ___________ 454

cobalt ores_____________ 602 

coral ____'__ __________ 476

distribution of silver 558

gold in recent pyrite__ 556

in sea water_________ 93

mercury in sinter_ _ 577

precipitation of gold_______ 558

silver in sea water. - 93

solvents of gold__________ 557

Livingstonite ______________ 573, 575, 597

Ljubavin, N., cave earth______ 205 

Ljusnan, River, analysis of water_ 81 

Locke, J. M., uintaite 625 

Lockycr, J. N., cited__________ 12

LOllingite _______________ 273, 595 

Loess ______________ 432-434

Loew, 0., analyses by___69, 120, 124, 189 

Loewe, L., cited, on Stassfurt salts- 176 

Loewinson-Lessing, F., classification

of igneous rocks___ 358 

eutectics __I-'J._________ 356 

magmatic differentiation- 245, 254, 255 

origin of volcanic gases_____ 230 

relative abundance of minerals- 251 

solubility of minerals in rnagrnas -____-____ 255 

Loewite ____ ________ 178,179,182 

Logan, W. E., and Hunt, T. S., phosphatic shell______ 448 

Lohmann, P., eclogite________ 517 

Loire, River, analysis of water___ 76 

Long, .T: H., cited___________ 60 

Longbanite ________________ 598 

Lorandite _ ___ _________ 595

Lord, E. C. E., analysis by______ 389 

Lorentz, R., synthesis of greenockite and wurtzite____ 578 

synthesis of troilite____ 272

Lorenzen, J., graphite in basalt__ 267, 268 ' 

Loretz, H., iron ores__________ 494 

' Losanitsch, S. M., chroniiferous

clays___________ 604

Lessen, C., itabirite_________ 525

quartzite ______________ 524

Lessen, K. A., albite alterations__ 512

Lossenite ________________ 590

Lossier, L., water, analyses__,___ 76

Lost River, analysis of water____ 70

Lotti, B., copper ores_________ 568

stibnite and cinnabar______ 597

Louderback, G. D., radioactivity and

volcanism _______ 259 

Loughlin, G. F., clays________ 431

 Page.

Louisville artesian well, analysis--- 145 

Luca, S. de, analysis by_____ __ 156 

Lucas, R., physical properties of

clays_____ 426 

Ludlamite ______________ 4.43 

Ludwig, A., artificial diamond___ 263 

Ludwig, E., analysis by___*__ 146,149 

Ludwig, F., analyses by___ 131, 187 

Ludwig, F. J. H., analysis by____ 161 

Luedecke, , water of the Oder- 80 

Luedeking, C., lead chromates____ 589 

Luedeking, C., and Wheeler, H. A.,

barite __________ 499 

Lujavrose ___ __________ __ 373 

Lunge, G., cited, on Stassfurt salts- 176 

Lunge, G., and Millberg, C., solubility of quartz____ 300 

Lunge, G., and Schmidt, R. E.,

analysis by___ 146 

Lunn, A. C., internal temperature of

the earth _______ 238 

Lupton, V. T., analysis of water__ 66 

Lutecite _________________ 295 

Luzi, W., corrosion of diamond-.__ 265 

formation of graphite _____ 266 

Lyell, C., precipitated calcium carbonate.______ 471 

Lyons, A. B., copper in lava : 544 

soils ________________ 431

M.

Mabery, C. F., natural gas__ 620 

petroleum___ 620, 622, 623, 624, 634 

See also Robinson, A. E. 

Mabery, C. F., and Byerly, J. H.,

byerlite ________ 627 

Mabery, C. F., and Hudson, E. .T.,

petroleum ______ 622, 623 

Mabery, C. F., and Palm, 0. H.,

Ohio petroleum ____ 622 

Mabery, C. F., and Quayle, W. 0.,

petroleum ______ 622, 624 

Mabery, C. F., and Smith, A. W.,

Lima oil ________ 624 

Mabery, C. F., and Takano, S.,

Japanese petroleum _ 622 

MacAlister, D. A- See Hill and

MacAlister.

Macallum, A. B., cited________ 97 

MacBride, T. H., peat_________ 648 

McCaleb, J. F., cited__________ 182 

McCalley, H., bauxite_________ 420 

McCallie, S. W., iron ores ___ 453, 594 

limestones_____________ 478 

phosphate rock__________ 450 

McClelland well, analysis______ 149 

McConnell, W., gases in coal_____ 662 

McCourt, W. E., and Parmelee, C.

W., peat________ 648

McCreary, P. L. See Evans, F. W.

McCreath, A. S., coal analyses___ 656

Mace", , synthesis of anglesite.- 588

McGee,. W J, bitumens________ 639

laterite _ _ _ _ ___________ 417

loess ________________ 433
696 INDEX.

Page.

Mcllheney, P. C., solvent of gold___ 557 

Mclntosh, D. See Eve, A. S. 

'Mclvor, R. W. E., guano phosphates- 444 

maldonite-_ _ ___________ 555

McKee, R. I-L, mass of atmosphere_ 49 

Mackie, W., analyses of clays__ 430, 431 

analyses of sand________ 428 

calcium fluoride as cement___ 461 

on age of the earth_______ 109 

sandstones _____________ 463

Mackintosh, J. B. See Hidden and

Mackintosh. 

Mackintoshite _ _ _ _ __________ 618

Maclaren, J. N., gold and silver In

sinter _ _ _ _ _____ 163, 556

hot springs of New Zealand__ 168 

Maclaren, M,, laterite________ 4.18 

Maclaurln, J. S., cited, on New Zealand spring waters__ 153 

Macomb deep well, analysis of water 150 

Mactear, J., mercury ores______ 573 

Madupite----_____________ 376

Madupose_ _ _ _ _ ____________ 376

Magma, temperature of______ 238-243 

Magmatic assimilation ______ 255, 256 

Magmatic differentiation _______ 253

Magmatic dissociation_______ 245-217 

Magmatic solutions_____1___ 244-247 

Magmatic stoping __________ 256 

Magmatic waters _ ______ 547 

Magdeburgose ________ 366, 367, 368 

Magnesioferrite _ _ _ _ __- _________ 279

Magnesite _ ____________ 351, 484

Magnesium, distribution_______ 17 

Magnenat and Wopten, analyses by_ 650 

Magnetite_________ 279, 282, 283, 284 

melting point _ _______ 240 

Magnetite spinellite_________ 393 

Magnochromite _____________ 604

Mahanuddy River____________ 82 

Main, River,'an'alysis of water___ 77 

Majorana, Q., diamond_______ 263 

Makin, C. J. S., analysis of sea

water__________ 94

Malachite ________________ 572 

Malbot, H. and A., phosphorite_____ 448

Malcolmson, J. W. See Kirk and

Malcolmson.

Maldonite __ __________ 555 

Malignose _________.______ 375

Malkomesius, P., and Albert R., Cassel brown ____ _ 651

Mallard, E., lead oxychlorides____ 588

Mallet, F. R., Indian corundum___ 277

laterite ___________ ___ 417

lateritic manganese_________ 456

on langbeinite___________ 179

Mallet, J. W., allanite_________ 618

analysis by _ _ 162

gases from meteorites__'.__ 234

silver in volcanic ash __ 221, 543

Maltha _________________ 626

Mangandolomite _____ _ _ 492

Manganese, distribution 17

in sea water__ _ ___ 93

ores of 419, 455-458

Page.

Manganese nodules___ 102, 103, 104, 455 

Manganite____ _ _ _ - 455 

Manganosite __ _ 455 

Manitoulin Island, analysis of water

from ____ _ __ 144 

Manjak __________________ 626 

Manley, J. J. See Giinther, R. T. 

Mann, P., alteration of 'titanite__ 288

constitution of pyroxenes-_ 318 

Manross, N. S., asphalt_____ 626

synthesis of apatite 292

of lead ores________ 588, 589

of scheelite_________ 606

Marcano, V. See Muntz, A____ 73

Marcasite ____ ____ 273

Marck, W., von der, analysis of

sandstone _ _ _ 461 

Marckwald, W., uranium ores____ 613 

Marcusson, J., artificial petroleum_ 630

origin of petroleum_____ 634, 639 

Margarite ____________ 327 

Margarodite ________ _ 32G 

Margottet, J., reduction of silver sulphide__________ 559

synthesis of argentite ___ 560

See also Hautefeuille and Margottet.

Marialite________________ 337, 338 

Maricose _ _ _ _ ____________ 390 

Marienquelle, analysis of water___ 143 

Marignac, C. de, synthesis of dolomite____________ 480 

Marigny, F, D., Algerian waters_ 59

synthesis of chalcopyrite.__ 567

synthesis of galena______ 584 

Marl______________ 441, 472, 486 

Marmora, Sea of, analysis of water. 95 

Marsden, R. S., artificial diamond_ 263

formation of crystalline silica 296 

Marsh gas______________ 633, 634 

Marshite _ _ _ _ _____________ 571

Marsilly, , analysis of peat_ 645, 646 

Martens, P., Chilean thermal waters- 205 

Martin, K, phosphate rock___ ____ 444

Martin, W. J., platinum ores_____ 608 

Martinite__ _ _ _ _ ___________ 444

Massicot_____ _ _ _ _ ________ 586

Masing, E., synthesis of anglesite__ 588 

Matildite _ _ _ _ ___________ 562, 563

Matlockite _ _ _ _ ____________ 587

Matteucci, R. V., volcanic ammonium chloride _____ 222 

Matthew, W. D., phosphatic nodules- 448 

Maumee River, analysis of water___ 61, 83 

Mauzeliite ________________ 598 

Mawson, D., carnotite-__1______ 616

Mawson, D., and Laby, T. H., radioactivity of minerals_ 260 

Maumene1 , E., manganese in sea

weeds _ _ _ _ 9'3

Maxwell, W., Hawaiian lavas and

soils----___ 417,423,431

Mayengon, , artificial galena_ 584

sulphides formed in burning

coal mine__ 596
INDEX. 697

Page. 

Mayr, F. See Simmersbach and

Mayr. 

Mead, W. J., relative proportions of

sedimentary rocks__ 31 

Meadows, T. C., and Brown, L.,

phosphorite _ _ _ _ __ 449

Mecca, holy well at, analysis of

water ____ ______ 154

Mediterranean Sea, analysis of

water.... _ _ 95

Medve Lake _____________ 132 

Menu, M. C.,' synthesis of cinnabar. 574 

Meigen, W., calcite and aragonite__ 473 

Meionite _ _ _ _ ____________ 337, 338

Melanite _____ ____________ 335

Melanochroite _____ _________ 588

Melanotekite _____ _________ 590

Meldometer _____ __________ 239

Meklrum, R., solubility of copper_ 565 

Meliltte ________________ 332-334 

Mellite________ _ _ _ _ _ ____, 644

Meionite. _________________' 599

Melville, W. H., analyses by__ 124,145,

154, 463, 468, 510,

522, 526, 576, 596

glaucophane rock________ 509

josephinite _____________ 269

Menaccanite _______________ 286

Mendelfief, D., origin of petroleum_ 631

periodic classification______ 35

Mendipite ________________ 587

Meneghinite _______________ 585

Mennel,. E. P., average composition

of igneous rock ____ 25

Mercury, distribution_________ 17

ores of____________1_ 572-577'

Merian, A., constitution of pyroxenes 318

Merivale, W., manjak_________ 626

Merrill, G. P., analyses by_____ 412

asbestos _______________ 318

cave gypsiim____________ 183

disintegration of rocks_____ 406,

408, 411, 412, 414

gold in granite_________ 271, 553 

onyx marble____________ 470 

serpentine _____________ 520 

Merrill, J. A., flint__________ 465 

Merrimac River, analysis of water_ 62 

Merz, , water analysis_____ 76 

Mesitite ________________ 351, 490 

Mesolite _:.________________ 350 

Metabrushite __ _ 444 

Metachlorite ______________ 331 

Metacinnabarite________ 573, 574, 576 

Metallic ores____________ 541-618 

Metamorphic rocks__ ____ 501-540 

Metastibnite _____________ 595, 597 

Meteorites, diamonds in_ _ _ 264 

gases from______________ 234

Meunier, S., analysis by___ _ 143 

bauxite ______________ 420 

carbon in meteorite_______ 632 

composition of fossil plants_ 654 

origin of petroleum_______ 631 

of platinum_______ 609, CIO 

planetary atmospheres--. __ 50

Page.

Meunier, S., synthesis of anorthite_ 301 

synthesis of brochantite___ 572 

of chromite ________ 282, 604 

of enstatite_________ 312 

of leucite______1___ 305 

of nephelite_________ 308 

of olivine___________ 325 

of phoenicochroite_____ 589 

of spinel ___________ 280 

of'tridymite_________ 296 

tin in sinter____________ 592 

troilite ________________ 271 

volcanic explosions_______ 243 

. See also DaubrSe and Meunier. 

Meuse, River, analysis of water__ 76 

Meyer, E., von, gases in coal____ 662 

Meyer, 0., calcite and dolomite__ 485 

Meyerhoffer, W., phase rule. _ 250 

See also Van't Hoff and Meyerhoffer.

Miargyrite_______________ 562, 563 

Miaskose ___.____________ 373, 378 

Micas_________________ 326-331 

Mica schist___________ 531, 532, 533 

Michael, P., saussurite gabbro____ 513 

Michel, L., bismuth in molybdenite. 605 

synthesis of azurlte _______ 572 

of lead ores____ __,._ 590 

of melanite__________ 336 

of minium and plattnerite_ 586 

of powellite _________ 605 

of -rutile____________ 289 

of titanite__________ 288 

of tungsten minerals___ 606 

Michel Le"vy, A., magmatic differentiation__________ 256 

minerals in sand.^___ 427 

primary epidote_____ _ 341 

quantitative classification. 365 

scapolite gabbro______ 514 

Michel-Le'vy, A., and Lacroix,' A.,

envelopment of allanite 342 

Michel-Le'vy, A., and Munier-Chalmas, E., chalcedony_ 295 

Michigan, waters of_______ _ 61 

Michigan, Lake, analysis of water. 61- 

Microcline_______________ 300-304 

Micrometric analysis of rocks 399 

Micro-organisms in coal formation_ 666 

Micropeginatite, as an eutectic___ 249 

Microsommite __ _____ _ 309 

Middlemiss, C. S., Indian.corundum. 277 

Miersite __'._________________ 564

Miklucho-Maclay, M. von, occurrence of cassiterite__ 291 

Milch, L., quantitative classification. 365 

Millberg, C. See Lunge and Mlll-

"berg.

Millelacs Lake, analysis of water 65-66

Miller, A. M., phosphatic fossils _ 448

Miller, W. G., cobalt ores______ 601

corundum anorthosite_ _ 277

limestone. _ 478-

nickel in magnetite_______ 282

Millerite ____________ 599, 600, 601

Mills, J. E., geological work of ants- 410
698 INDEX.

Page. 

Milosin___________________ 604

Mimetite________________ 589, 590

Minervite_________________ 445

Minette________________ 371,372

Minette (iron ore)________ 494

Mine waters__________ 144, 148, 546

Mineral waters, classification- 140, 157, 158

Mingaye, J. C. I-I., analysis by__ 151

cave phosphates _ _ 445

platinum ______ __ _ _ 610

vanadium in clay_________ 612

Minium _________________ 586

Minnetonka, Lake, analysis of water- 66 

Minor, J. C. See Penfield and Minor. 

Minssen, EL, and Tacke, P.., solubility of calcium phosphate___________ 443 

Mirabilite ______________ 181,187 

Mispickel_________________ 595 

Mission Creek, analysis of water_ 70 

Missouri River, analyses of water_ 67 

Missourite______________ 376 

Mississippi River, analyses of water. 65 

chlorine in___ _ __ 85 

flow of________________ 65 

sedimentation in________ 429

Mittngong chalybeate spring, analysis ___________ 151 

Mitchell, , water analysis cited_ 129 

Mitchellite_____________^__ 604 

Mixite ___________________ 571 

Mizzonite ________________ 338

Moricke, W., gold in pitchstone_ 271, 553 

Mofettes _________________ 214. 

Mohawklte ________________ 567 

Mohawk River, analysis of water__ 62, 83 

Moissan, EL, analyses of volcanic

gases _______ _ 219

carborundum in meteorite____ 266

graphite in pegmatite ______ 267

melting point of corundum __ 274

metallic carbides _________ 628

on diamond____________ 263, 264

origin of petroleum_______ 631

origin of volcanic activity__ 230, 233

volatility of metallic oxides__ 223

See also Becquerel and Moissan.

Moitessier, A., artificial dolomite __ 481

Moldau River, analysis of water.__ 77, 78

Moldenhauer, , water analysis_ 76

Molengraaf, G. A. F., cordierite vitrophyrite _______ 339 

Molengraaf, P. F., cassiterite____ 594 

Molybdenite ___________ 273, 605, 606 

Molybdenum, distribution______ 18 

ores of ______________ 605-607 

Molybdic ocher_____ _______ 605 

Molybdophyllite________&______ 590

Monazite __ ___________ 293, 294, 618 

Monchiquite ___________'.__ 379 

Monckton, G. F., mercury deposits_ 577 

Monetite__________________ 444 

Mcnke, EL, and Beyschlag, F., origin

of petroleum____ _ 634 

Monmouthite ______ - 376 

Mono Creek, analysis of water _ 70

Page.

Mono Lake, analysis of water__ 124, 137 

Monongahela River, analysis of

water __________ 66 

Montesano Springs, analysis_____ 142 

Monticellite______________ 324, 326 

jMontmorillonite ____________ 527 

Montroydite _______________ 573 

Monzonite_______________ 380, 381 

fusibility ______________ 242 

Monzonose______:_____ 370, 380, 384 

Moore, C. C., barytic sandstones__ 461 

sandstones _________ ____ 463 

Moore, G. E., analysis by_______ 154 

Moosehead Lake, analysis of water_ . 62 

Morawsky, T. See Schinnerer and

Morawsky.

Mordenite ________________ 350 

Moreing, C. A., manganese ores_:__ . 456 

Morenosite________________ 602 

Morley, E. W., variations in atmospheric oxygen_____ 39/40 

Morlot, A. von, sand calcites __-_ 459 

synthesis of dolomite______ 481 

Morozewicz, J., alteration of diorite_ 413 

analyses by____ _______ 393 

artificial feldspars________ 301 

formation of acmite______ 315, 316 

of augite___________ 317 

of corundum_____ 275, 270, 277 

of enstatite________ 312, 313 

of hematite__________ 285 

of iolite____________ 339 

of magnetite _________ 283 

of mica_____________ 329 

of nephelite __________ 309 

of quartz and tridymite__ 297 

of sillimanite _______ 343, 344 

lagoriolite _____________ 335 

gravitative adjustment in magmas ___________ 258 

syntheses of noselite, haiiynite

and sodalite _____ 310, 311 

of pyroxenes ________ 314 

solubility of alumina in magmas ___________ 251 

Morse, H. W., gases in fluorite___ 274 

Morton, E. H. See Thorpe, T. E. 

Moses, A. J., mercury minerals__ 573 

Moses, 0. A., phosphate rock____ 449 

Moses Lake, analysis of water__ 125, 136 

Moss, E. L., on Arctic air___^__ 42 

Mottramite ________________ 612. 

Moulton, F. R., internal temperature

of the earth______ 238 

Moureu, C., and Biquard, R., argon

and helium in waters- 140 

Mourlot, A., vanadium in coal___ 612 

Mrazec, L., and Teisseyre, W., Roumanian salts _____ 187 

salt lakes of Roumania____ 132 

Mrha, J., kelyphite __________ 336 

Muchin, J. von, analyses by_____ 608 

Muck, F., constitution of coal___ 667 

Muck, J. ozokerite___________ 625 

Muds, oceanic____________ 436, 437 

Miigge, 0., calcite and aragonite_^ 473
INDEX. 699

rage.

Miigge, 0., occurrence of perofskite 288

scapolite amphibolite _ __ 515

transition of quartz_ __ 297

MiilMuser, 0., artificial graphite_ 266

Miiller, H., mine water_______ 546

MUller, R., solubility of .minerals 293,

403, 404, 442

Miiller, W., artificial magnetite___ 283 

Miiller, W. ,T. See Konigsberger and

Miiller.

Muellerite ____________ 444 

Munster, C. A., gold in sea water- 93 

Miinster, H., bauxite__________ 420 

Munroe, C. E., artificial hematite_ 285 

Muntz, A., atmospheric transport of

salt ___________ 48 

bacterial decomposition of

rocks ________ 409, 410

bromine in Chilean niter - 208

nitrates in the Nile _______ 82

origin of nitrates 1_____ 209, 210

Muntz, A., and Aubin, E., oxygen of

the atmosphere ____ 39 

Muntz, A., and Marcano, V., black 

waters of South America __________ 73 

cave nitrates _________ 205

nitric acid in rainfall_____ 46 

Murdoch, ,T. A. W., atacaraite.___ 571 

Murgocl, G. M., riebeckite rocks _ 323 

Murray, Sir J., chemical reactions

on ocean floor______ 101 

oceanic carbonic acid _____ 113 

origin of manganese nodules__ 102 

saline matter in rivers_____ 88 

total annual rainfall and runoff ____________ 53 

volume of the ocean________ 22

. Murray, J., and It-vine, R., ammonia

in sea water______ 92 

calcium carbonate in sea water- 97 

formation of siliceous ooze __ 439 

maintenance of marine life___ 116 

manganese nodules _______ 102 

re-solution of coral rock_____ 99

secretion of lime salts by marine animals______ 100 

sediment in sea water ____ 429 

silica in sea -water ________ 92

Murray, .T., and Renard, A. F., deep

sea deposits ____ 101-106 

glauconite __________'__ 439, 440 

oceanic sediments _______ 435, 436 

origin of glauconite _____ 105 

phosphatic nodules _____: 104, 447 

solubility of silica_______ 100 

Muscovite ________________ 326-331

N.

Nadorite __________ 

Nagyagite . 

Nantier, A., phosphorite. 

Nantokite _______.

-___ 590

____ 584

____ 451

____ 571 

Napalite ______________ 576, 624, 625

Naphtenes ________________ 622

Naphthalene ______________ 623

Page. 

Naschold, W. See Haeussermann and

Naschold.

Nasiui, R., and Anderliui, F., analysis by_________ 142- 

Nasini, R., Anderlini, F., and Salvador!, R., fumarole 

gases __________ 148, 216 

Nasini, R., arid Levi, M. G., radio- .

activity of lava____ 259 

Nasini, R. See also Pen-one and Nasini.

Nason, F. L., Franklin zinc ores__ 584

iron ores ___ _______ 494

scapolite rocks _____ 515

Nasonite _______________ 590

Nastukoff, A., cellulose________ (142

Natrolite _________________ 349

Natron___________ '125,191, 199, 200

Natron Lake, analysis of water 133,136

Natterer, K., ammonia in sea water. 92

analyses of water ____ 94, 95, 130

marine muds___________ 438

on marine clays__________ 107

Natural gas __________ 620-621, 6.33

Naumannite ___________ 562, 584

Navarro, F., native iron_______ 267 

Neagh, Lougli, analysis of water__ 76, 83 

Nebular hypothesis__________ 108 

Negro, Rio, analysis of water-___ 74, S3 

Nelson, J. L., analysis by_______ 320 

Nelson River, analysis of water__ 7.1 

Nontien, antimony ores____ 597 

Neodymium ________________ 18 

Neon ___________________. 1.8,38 

Neosho River, analysis of water__ 69 

Nephelite ________________ 307-309 

melting point _________ 240

Nephelite basalt_____________ 387 

Nephelite rocks____________ 373-376 

Nephelite syenite__________ 24.2, 374 

Nepouite _________________ 603 

Nesquehonite ______________ 483 

Nessler. See Petersen and Nessler. 

Neuberg, C., origin of petroleum__ 634 

Nevadite _________________ 366 

Nevius, .T. N., tin deposits_____ 593

Nevyanskite _______________ 607

Newberry, J. S., bog-iron ore____ 452

cannel coal ____________ 655

origin of petroleum______ 637, 638

ozokerite _____________ 625

Newbery, .T. C., gold in iron ore___ 556

Newberyite _______________ 444

Newsom, .T. F. See Brauner and

Newsom.

Newton, W., origin of nitrates____ 209 

Newtonite _________________ 527

New Zealand geysers, analyses of

waters _______ 153, 156

Niccolite _____________1 __ 599,601

Nichols, H. W., cave nitrates____ 205

Nicholson, E., cited___________ 82

Nickel, distribution___________ 18

in ashes of sea weed_______ 93

ores of J_____________ 598-603

Nickel-iron, native__________ 269, 270

Nicolardot, P., hydroxides of iron- 453, 454
700 INDEX.

Page.

Nile River, analysis of mud__ _ 429

analyses of water _________ 82, 83

sedimentation in______ 429

 Niobium. See Columbium.

Nitrate deposits ___________ 205-211

Nitric acid in rainfall_____ 46

Nitrogen, distribution--____ 18

in sea water __:._____- 91

proportions in the atmosphere_ 39, 40

volcanic origin of________ 222

Nitrogen bases in petroleum__ 624

Nitroglauberite__________ 206, 208

Nitze, If. B. C-, iron ores_______ 494

monazite _____________ 294, 618

Nivenite _________________ 614

Nivoit, E., phosphate rock__ _ 442

Nocerite _________________ 221

Noeggerath, J. J., pyromorphite in

slag ___________ 589 

Noellner, C., origin of nitrates.---.. 209 

Noelting, J., zinc blende____-__ 578 

Nontronite __-__-______ _ 416 

Nordenskiold, A. B., carbon in meteorite __ ______ 632 

native iron in Greenland__. 268 

uranium in coal________. _ 616 

Nordenskioldine __________ 591, 593 

Nordmarkite ______________ 370 

Nordmarkose ______________ 370, 374 

Norite ___________________ 390 

Northupite ____________1 _ 200 

Nosean. See Noselite. 

Nosean sanidinite___________ 378 

Noselite________________ 309-311 

Noumeite_______________..__ 603 

Novaculite_______________ 464, 466 

Noyes, W. A., analyses by___ 60 

61, 65, 71, 148, 412 

Nutter, E. H., and Barber, W. B.,

glaucophane rocks 509

O.

Oak Orchard acid spring, analysis_ 155

Obalski, J., uranium in pegmatite. 616

Obsidian _________________ 367

fusibility of__________. 244

Occlusion of gases in rocks____ 224-232

Ocean, age of_____________ 109,110

composition of_________. 23

elements in__________ 91, 92, 93

gases in___________ 110-115

influence of living organisms on 115

116, 117

the primeval_ _______ 108 

volume of_____________ 22 

Ocean water, carbonates in~_ 98, 99,100 

changes in composition due to

freezing_____ .___ 96

concentration of__ 173,174, 175,176

density and salinity of ___ 96, 97

Oceanic salts, composition of_-.._ 94-98

volume of____________.._ 23

Oceanic sediments_________ 435-439

Ochers as spring deposits '..____ 160,161

Page.

Ochrolite ___________._____ 590 

Ochsenius, C., average composition

of igneous rock __-__ 25

cited, on Stassfurt salts____ 176

on Great Salt Lake______ 119

origin of alkaline carbonates_. 195

of borates__________ 204

of petroleum_______ 635, 636

of salt bedsJ_______ 175, 176

saltpeter deposits_______ 206, 210

Octahedrite______________ 288-290

Oebbeke, K., glaucophane rocks_ 323, 509

Oehmichen, H., chalcanthite____ 571

Ogden River, analyses of water__ 120

Ojo Caliente, analysis of water__ 149

Okenite __________________ 350

Oklahoma, river waters ______ 68

Oldbam, R. D., laterite________ 417 

Old Wives Lake, analysis of water. 126,135 

defines _______________ 621/622 

Olette Springs, analysis_______ 152 

Oligoclase _________^_____ 300 

Olivenite ________________ 570 

1'Olivier, V., Chilian nitrates___ 206, 207 

Olivine ________________ 323-326 

melting point _________ 240 

Om, River, analysis of water____ 81 

Orneose _________________ 368 

Onega, Lake, analysis of water____ 81

Onofrite _________________ 573 

Onyx marble______________ 470

Oolite, water from___________ 76

Oolite, calcareous_________ 471, 474 

Oolite, siliceous_____________ 466 

Oolitic sand ______________ 121,471 

Opal _______________ 294-300,465 

Organic matter in rock decomposition _________ 408,409 

Organic matter in waters______ 83 

Orpiment _____________ 595,596 

Orthite _________________ 340 

Orthoclase ______________ 300-304 

Orthogneiss _______________ 534 

Ortlieb, J., ciplyte___________ 446 

Orton, E., dissemination of petroleum __________ 639 

origin of petroleum______ 634 

spore cases in coal_______ 666 

Osann, A., classification of igneous

rocks ________- 358 

Osmium _____________ 18, 607-611 

Osteolite __!______________ 443 

Ottawa River, analysis of water__ 61 

Ottrelite ________ 327,330,529,530 

Ottrelite schist____________ 530 

Cutwater, R., analysis 'of water____ 63

Ovenstone ____' _________ 522

Owens Lake, analysis of water_ 124,137 

soda from___ ________ 192

Oxygen, concentrated by solution . 45

distribution ___________. 18-

proportions in the atmosphere. 39, 40

solubility in salt water__ 110,111

Ozokerite ____________ 624,625,638

Ozone in atmosphere.*________ 40
INDEX. 701

p. Page.

Packard, R. L., analysis by____ 412 

Pagenstecher, J. S. F., water analyses ___________ 76 

Pahuu Spring, analysis.-__ ' 142 

Palache, C.., crossite__________ 322 

Sec also Jaggar and Palache; 

Lawson and Palache; 

Kansome and Palache.

Pallc Lake, analyses of water.__ 132, 136 

Palladium _____________ 18, 607-611 

Palladium gold____________ 555, 607 

Palm, 0. H. See Mabery and Palm. 

Palmer, A., chlorine in river waters- 85 

Palmerite_________ ______ 445 

Palmierite ______________1_ 221, 588 

Pantanelli, X>., origin of petroleum- 635 

Pandermite _____________ 200, 201 

1'apngayos, Rio de los, analysis of

water __________ 74 

Papavaslliu, S. A., emery_______ 278 

Pappe, A., and Richmond, H. D.,

water analysis_ __ 133 

Paraffin series_____________ 619-620 

Paragonite______________ 326-330 

1'aragneiss ____.______ ___ . 534 

1'aralaurionite _____________ 587 

Paramo de Ruiz, hot spring, analysis ____________ 156 

Parana, River, analysis of water__ 74 

Pargasite_..______________ 319 

Park, J., mercury, ores_______ 577 

Parmelee, C. W. See McCourt and

Parmelee. 

Parmentier, F., alumina in mineral

waters ________ 420 

synthesis of quartz and tridymite___________ 297 

Parr, S. W., classification of coals_ 659 

Parry, J., gases in iron________ 234 

Parsons, A. L., gypsum ______ 185

peat_________________ 648

Passarge, S., laterite__________ 417

Patton, H. B., analysis by______ 367

'formation of tourmaline____ 347

Patronite__________________ 613

Pnyen, A., Tuscan fumaroles____ 198

Pearce, R., solvent of gold______ 557

uraninite ______________ 613

Pearceite ___ _ ___ _____ 562

Peat ________________ 645-648, 663

cupriferous ___________ 566

Peckham, S. F., alberti'te______ 625, 626. 

origin of petroleum_______ 637 

petroleum___ ______ __ 624

Peckham, S. F. and H. E., sulphur

in petroleum______ 624

Pecos River, analysis of water____ 69 

Poctolite__________________ 350 

Peganite __________ 443 

Peile,-W., bauxite.__________ 420 

Peipus, Lake, analysis of water 81 

Pelikan, A., analcite phonolite____ 307 

Pellew, C. E. See Chandler, C. F. 

Pemberton, H., and Tucker, G. P.,

water analyses.- _ 126

Page.

Pencatite ________________ 489

Penfield, S. L., analyses by_____ 618

caesium beryl___________ 347

sulphohalite ____________ 199

See also Dana and Penfield;

Genth and Penfield; . 

Iddings and Penfield; 

Wells and Penfield. 

Penfield, S. L., and Foote, H. AV.,

composition of tourma- . 

line ___________ 347 

magnesia in ilmenite______ 286 

Penfield, S. L., and Forbes, E. H.,

fayalite in granite__ 325 

Penfield, S. L., and Ford, W. E.,

sand calcite_______ 459 

Penfield, S. L., and Jamieson, G. S.,

tychite..________ 200 

Penfield, S. L., and Minor, J. C.,

formula of topaz___ 342 

Penfield, S. L., and Pratt, J. H.,

formula of staurolite. . 344 

Penfield, S. L., and Sperry, F. L.,

chlorite pseudomorphs. 336 

Penfield, S. L., and Stanley, F. C., 

composition of hornblende ________ 319,322 

Penfieldite ________________ . 587 

Penhale, M., chromite deposits___ 605 

Pcnninite ______.._________ 331 

Penrose, R. A. F., alterations of ore

deposits __ _____ 551 

iron ore from glauconite___ 453, 492 

manganese ores __ __ -.-__ 456 

phosphate rock.. _ 442, 450 

- tin deposits _____ ____ 593 

Pentlandite ______________ 599, 600 

Perchlorates in Chilean water____ 208 

Percy, J., coal analysis _ 656 

Percylite __________________ 587 

Periclase _______-_________ 538 

Peridot __________________ 324 

Peridotite _________ 390-392 

Periodic classification of the elements _ 33 36 

Perofskite ________________ 287, 288 

Perrey, A. See Hautefeuille and

Perrey. 

Perrone, E., and Nasini, A., origin

of borates 198 

Peter, R., matter extracted from soil

by plants._ 409 

Petermann, A., and Graftlau, J.,

cited __________ 42,46 

Petersen,' T., bauxite 420 

nickel in magnetite 282 

Petersen and Nessler, analyses of

peat __._________ 645 

Petersen and Schodler, analyses of

wood _____ 643 

Petersson, W., analysis by 393 

Petrasch, K., fusion of mineral mixtures ____ - 252 

Petroleum _____ 619, 641
702 INDEX.

Page.

Pettersson, 0., on brine from melting ice __________ ^ 96 

Pettersson, "O., and Sonde"n, K., on

air from sea water_ 45, 111 

Petzite __ _ 555 

Pfaff, F. W., dolomitization______ 483 

Pfeiffer, E., cited on Stassfurt

salts__________ 176, 177 

Pfordten, 0. von der. See Kunig, T. 

Phacelite ________________ 307 

Phalen, W. C., unakite________ 516 

Pharmacolite _ 598

Pharmacosiderite ____________ 598 

Phase rule ________________ 250 

Phenol, in petroleum__________ 623 

Philip, R. S. See Gibb and Philip. 

Phillips, A. EL, carnotite_______ 616 

Phillips, F. C., formation of marsh

gas __'_.._______ 634

natural gas 621 

petroleum in fossils_______ 636

Phillips, J. A., desert sand_____ 427

gold on cinnabar _ __ 556 

mercury deposits _______ 577

mine waters ____ 546

sandstone ____ _ 463

Phillips, W. B., iron ores____ 494

phosphorite ______:___ 449

Terlingua mines_________ 573 

Phillips, W. B., and Hancock, D.,

bauxite __ __ _ 421 

Phillipsite ___________ 102, 350, 351 

Phipson, T. L., primitive atmosphere- 50 

Phlegrose _______________ 370 

Pblogopite _______________ 327-330 

Phcenicochroite 588, 589 

Phonolite __ _ ___-^_ 373 

fusibility ______________ ^42 

Phosgenite ______ _ 587 

Phosphate rock 442-451 

Phosphatic nodules _ 104, 105, 447 

Phosphorite _ ___________ 442-451 

Phosphorus, distribution_______ 18 

in sea water___________ 92

Phosphosiderite ____ ______ 443

Phyllite ______________ 524, 525,529 

Pichard, P., solubility of minerals_ 403 

Pickeringite __ __ 202

Picotite -_________________ 281 

Picrite ___________________ 390 

Picromerite ______________ 178, 179

Piedinontite _____________ 340, 341 

Pierre, I., salts in rainfall______ 48 

Pigeon River, analysis of water__ 61 

Pimelite _________________ 603 

Pinite __________________ 339, 340 

Pinnonite ________________ 180, 202 

Pinnow, J. See Will and Pinnow. 

Pirsson, L. V., cassiterite in hematite_____________ 592 

crystallization of magmas___ 257 

primary analcite ________ 306, 378

See also Weed and Pirsson. 

Pirssonite __________________ 200 

Pisani, F., analysis of spinel _ 280 

See also Saemann and Pisani.

Page.

Pisolite __________________ 473 

Pistomesitc ________,_______ 490 

Pitchblende _______________ 613 

Pitch coal_______________ 624, 625 

Plagi'onite _______________ 585, 586 

Planetesimal hypothesis_____ 51, 52, 108 

Plata River, analyses of water_____ 74, 83

Platiniridium ____- _____________ 608

Platinum, distribution ________ 18

in igneous rocks_...__________ 271

ore of_______________ 607-611 

Platte River, analyses of water___ 56, 67 

Plattensee, analysis of.water____ SO 

Plattnerite __________'_____1 586 

Plauchud, E., reduction of sulphates

by microbes_______ 496 

Playa lakes______..________ 189 

Playfair, L., colliery gases_______ 663

Pleonaste _______________ 280, 281 

Plombi&res, action of hot waters at.

on brick_________ 166 

analyses of waters cited-___ 166 

Plumbogummite ______________ 590 

Plumbojarosite _____________ 588 

Podolite__________________ 293 

Poeschl, V., fusion of mineral mixtures __:_________ 252 

Pollard, W. See dough and Pollard. 

Polianite _______________________ 455

Polonium ____________'____ 615 

Polyargyrite _______________ 562 

Polybasite ________________ 562 

Polydymite ____________.___ 599 

Polyhalite ____________ __ 178, 181 

Polylithionite ______________ 326 

Polymethylenes_____________ 622 

Popocatepetl, water from____ 156

Popoff, L., gas from river mud____ 633

Popoff, S. P. See Vernadsky and

Popoffi. 

Popovici, Saligny and Georgesco,

water analysis____ 132 

Popp, 0., boron nitride _______ 197 

water analysis __________ 82 

Porcher, S., electrum__________ 555 

Porter, F. B. See Bailey, E. II. S. 

Porter, J. L., analysis of water-___ 64 

Porter, J. T., fuller's earth_____ 431 

Posepny, F., atmospheric transport

of salt __________ 48 

lateral secretion________ 542, 543 

heavy metal,s in waters____ 546, 547

ore deposits _ _____J____ 541

Posewitz, T., asphalt and petroleum. 627 

Potassium, distribution ______ 19 

proportion of, in ocean____ 106, 107 

Potassium nitrate. See Saltpeter. 

Potassium salts, absorption by

clays __________ 107, 166 

Potomac River, analysis of water__ 63 

flow of _______________ 64 

Potonie, H., origin of petroleum__ 638 

Pouget, I., artificial pyrargyrite __ 562 

Powder River, analysis of water__ 70 

Powellite ____ 605
INDEX. 703

Page.

.Power, F. D., nickel ores_______ 603 

Pozzuoli, analysis of solfatara

water_!_________ 15G

Praseodymium ______________ 19

Praseolite ________________ 340

Pratt, J. H., chromite deposits 282, 605

corundum _____________ 278

gaylussite, uorthupite, pirssonite '.__________ 200 

occurrence of spinel_ 281 

origin of talc___________ 349 

talc ________________ 522 

See also Hidden and Pratt;

Penfield and Pratt. 

Pratt, .T. H., and Lewis, J. V., chromite deposits______ 605 

Pratt, J. H., and Sterrett, D. B.,

tin deposits _ 594

 Pratt, N. A., phosphate rock_____ 450

Precht, H., cited, on Stassfurt salts. 176

on langbanite___________ 178

Precht, H., and Wittjen, B.,

kleserlte ________ 181 

Predazzite ___________ 489, 490, 539 

Prehnite rock_____________ 539 

Pretoria salt lake, analysis of

water_________ 133,136 

Price, T., water analysis__ 70 

Priceite __________________ 200 

Priestley, J., gases in rocks _ 224 

Primero, Rio, analysis of water__ 74 

Pring, J. N., and Button, R. S., 

synthetic ' hydrocarbons__________ 629 

Prior, G. T., dundasitel_______ 586 

riebeckite rocks __________ 323 

teallite, etc____________ 591 

Sec also Hussak and Prior. 

Prior, G. T., and Spencer, L. J.,

cerargyrite group _ 564 

Prismatine - ____________ 316 

Prochlorite _,.______________ 331 

Frost E. See Spring, W. 

Proustite________________ 562, 563 

Prowersose _______________ 372

Przibylla, C., formation of carnallite____________ 180 

Pseudoboleite ______ __Q ____ 587

Pseudobrookite _____________ 287 

Pseudogaylussite ____________ 123 

Pseudoleucite ______________ 307 

Psilomelaue _ 455 

Psittacinite ________________ 590 

Pteropod ooze__________ 101, 436

Ptilolite _________________ 350 

Pucherite ________________ 612 

Puiggari, M., cited___________ 74 

Pulaskose ____________ 370, 378, 383 

Pulgar, P. del. See Calderon, C. S.,

etc.

Pumpelly, R., native copper_____ 565 

sedimentation _______ 432

Purington, C. W., Uralian platinum_ 609 

Pyramid Lake, analysis of "water__ 122 

Pyrargyrite _______ ______ 562, 563

Page. 

Pyrite _____^ _______ 222, 271-273

Pyrocatechin ______________ 668 

Pyrochroite _____________ 455

1'yrolusite _______________ 455

Pyromorphite _____________ 589, 590 

Pyrope ________________ 334-337 

Pyrophanite _____________ 286

Pyrophyllite ___________ 417, 522, 527 

Pyrostilpnite ______________ 562 

Pyroxene _____________ 311-318, 508 

Pyroxenite _____________ 390, 391 

Pyrrhotite______ 222, 271-273, 600, 601

Q.

Quadrat, B., analysis of spinel___ 280

Quartz _________________ 294-300

gaseous inclusions in_______ . 224

melting point._____ _ _ 240

volatility of__________ 223

Quartz-alunite rock __________ 421

Quartz-diaspore rock_________ 421

Quartz diorite_____________ 381, 382 

Quartz monzonite___________ 380 

Quartz porphyry __________ 366-368 

Quartz trachyte_____________ 366 

Quartzine ________________ 295 

Quartzite_________________ 523, 524 

Quayle, W. 0. See Maybery and

Quayle. 

Quensel, P.' D., formation of quartz

and tridymite ___ 297 

Quincy mine, analysis of water from_ -144

R.

Radioactivity _______ 152, 259, 615, 618 

Radiolarian ooze___._____ 101. 436 

Radium ________ 19, 259, 260, 615, 616 

Radominsky, F., synthesis of mona-'

zite and xenotime__ 293 

Ragsky, F., analysis by____ ___ 151 

Rainfall _______ _______ 44-48, 53 

Raken, M. See Cohen, E. 

Rakusin, , petroleum_______ 639

R'amage, H. /See Hartley, W. N. 

Ramirite __________: ________ 613

Rammelsberg, C., composition of

tourmaline_______ 346 

Rammelsbergite ____________ 599 

Ramsay, Sir W., composition of the

atmosphere________ 38

sedimentation _____ 429 

Ramsay, W., and Travers, M. W., 

argon and helium in 

minerals ______ 225

Ramsay, W. (of Helsingfors), and 

Illiacus, A., monazite 

in pegmatite______ 294 

Ramsay and Hunter, sintering of

silica __________ 299 

Rangeley Lake, analysis of water_ 62 

Ransome, F. L., chert____ 465

glaucophane schist ___ 509 

lawsonite _____________- 345 

See also Hlllebrand and Ransome.
704 INDEX.

Page. 

Ransome, F. L., and Palache, C.,

lawsonite_______ 345

Rath, G. vom, anorthite in marble_ 538

sublimed silicates_1______ 223

sulphur deposits ________ 497

Rathite __________________ 585 

Rayleigh, Lord; hydrogen in atmosphere___________.' 41

Raymond, R. W., uintaite______ . 625

Read, T. T., copper sulphide____ .569

phase rule_____________ 250

platinum ________,______ 611

Reade, T. M:, chemical denudation- 89, 90

radium and geology _____ 260

Realgar ___________ 215, 221, 595, 596

Rectorite _________________ 527

Red clay, oceanic _____ __ 101

Red Lake, analysis of water___ 130, 135

Red River (Louisiana), analysis of

water __________ 69 

Red River of the North, analyses

of water ________ 71

Red Sea, analyses of water___ 95 

Redingtonite ______________ 604 

Redwood, B., formation' of petroleum___________ 637 

Reese, ,'C. L., solubility of calcium

phosphate _______ 443 

Refdanskite________________ 603 

Regnault, V., oxygen of the atmosphere___________ 39 

Reich, A., synthesis of sillimanit.e_ 343 

of topaz____________ 342 

See also Stutzer, A.

Reichardt, E., analysis of bittern__ 186 

Reichardtite ______- _________ _ 178

Reiche'rt, F., Argentine borates___ 202 

Reid, C., and Scrivenor, .T. B., cassiterite _________ 592. 

Reid, W. F., Argentine nitrates__ 208 

Reinders, G., bog-iron ore____ 452, 454 

Reindl, J., cited_____________ 73 

Reinitzer, B., trona__________ 192

Reiset, J., carbon dioxide in air__ 42 

Reiss, E. R., eclogite_________ 516 

Reiter, H. H., fusion of mineral

mixtures ________ 252 

Reitinger, J. See Hussak and Reitinger. 

Remingtonite _______________' 602

Renard, A. F., phthanite_______ 464 

phyllites _______________ 530 

See also Murray, J. 

Renard, A. F., and Cornet, T., phosphorite__________ 448 

Renault, B., cannel coal________ 655

peat _________________ 647 

micro-organisms in coal____ 666 

See also Bertrand and Renault. 

Rennie, E. H., vanadium in clay__ 612 

Republican River, analysis of water_ 68 

Retgers, .T. W., constitution of pyroxenes_______ 318

minerals in sand________ 427

Reuss, A. E., sand in harite___.__ 461 

Renter, M. Sec Treadwell, F. P.

Page.

Reyer, E., volcanism _ _ _ 232 

Reyes, Rio de los, analysis of water_ 74 

Re/banyite________________ 585 

Rheineck, H., composition of tourmaline __________ 346 

Rhine River, analysis of silt_____ 429 

analyses of water_________ 77, S3 

Rhodium ______:________. 18, 607-611

Rhodium gold_____1________ 607 

Rhodochrosite _____________ 490 

Rhodonite ________________ 314 

Rhodusite ________________ 322 

Rhoenite _________________ 323 

Rhone, River, analysis of water.__ 76 

Rhyolite________________ 366, 367 

fusibility _____________ 245, 246 

Riban, .T., synthesis of cerussite__ 587 

Ricciardi, L., vanadium in lava___ 611 

Richards, Ellen S., chlorine maps_ 47 

Richards, R. H. See Day and Richards.

Richardson, C., asphalt_______ 626, 627 

Richardson, C., and Wallace, E. C.,

Texas petroleum.___ 622

Richardson, G. B., natural gas____ 620

sulphur deposits__________ 497

tin deposits__________ 594

waters of Utah__________ 119 

Richardson, T., barytic deposit..__ 498 

Richmond, H. D. See Pappe, A. 

Richterite _____________:__' 319 

Richthofen, F., loess__________ 432 

Rickard, E., tin deposits_______ 594 

Packard, F., tungsten ores______ ' 607 

Rickard, T. A., precipitation of silver __________ 559

solution and deposition of

gold __________ 557, 558 

Rickardite __________________ 567

Riebeckite______________ 322, 323

PJes, H., alteration of pyroxenes__ 318

clays_ _ _ _ _ _ _ 431

limestones _____________ 478

peat _________________ 648

zincite- _ ______________ 580

Riggs, R. B., analyses by______ 381,

430, 431, 432, 433, 492, 514, 524, 534

Rinne, F., reactivity of quartz;.___ 300

Rio Grande) analysis of water____ 69

Rising, W. B. See Le Conte and

Rising.

Ritter, A., nature, of earth's interior _____________ 52

Rivas, S., cited_.____________ 74 

Roberts, J. See Anderson and Roberts.

Roberts, M. G. See Dole, R. B. 

Roberts-Austen, W. C., melting points

of minerals_____ 239, 240 

Robinson, A. C., and Mabery, C. F.,

analysis by _,____ 144

Robinson, F. C., analyses of water_ 62 

phosphoric acid in beryl-___ 347 

Robertson, J. D., heavy metals in

rocks__________ 543,582

precipitated zinc sulphide____ 579
INDEX. 705

Page.

Robertson, J. D., zinc deposits__ 583 

Rockbridge Alum Spring, analysis-- .155 

Rock River, analysis of water __ 66 

Rodssyanko, A., cited-_______ _ 83

Rocblingite _ _ ______________ 590 

Roepperite_ _ _ _ _ : _ - 324

Roessler, P., synthesis of argcntite_ 5GO 

of galena and clausthalite_ 584 

Bossier, H., platinum in silver bul-

. lion__-_______ 610 

 Rottlslte--.______________ 603 

Rofe, .T., cannel coal-_________ 655 

Rogers, A. F., alterations of copper- 566 

riebeckite rocks __________ 323 

Rogers, W. B. and R. B., solubility of

minerals_______ 403

Rohland, P., plasticity of clays 425 

Romburgh, P. van, analysis by__ 154 

Romeite------ - 598

Roncegno, analysis of water from_ 146, 147

Rondet, J., sulphosalts of lead___ 586

Roozeboom, H. W. B., phase rule 250

Roscoe, H. E., mottramite______ 613

Roscoelite--__________ 326, 613, 616

Rose, G., fusion of limestone 477

synthesis of-tridymite______ 296

uralitization_____________ 508

Roselite--____________ 602

Rosen, F., alteration of dolomite__ 490

Bosenbacn, 0., volcanic nitrogen- 222

Rosenbusch, H., chloritic substance- 518

classification of igneous ro'cks.,- 358

epidotization_ _ _ _ __ - 515

garnet and prehnite rock _ 539 

glaucophane rocks . 323 

gneiss______________ 534

order of deposition of minerals- 252 

succession of minerals in igneous rocks_______ 396, 397 

venanzite __ '_ 386 

See also Hunter and Rosenbusch. 

Rosenbuschite _ _ _ _ __ _ 317

Rosenlecher, R., mercury deposits 577 

Rosiwal, A., physical analysis of

rocks ____ _______ 399

Ross, O. C. D., origin of petroleum. 632 

Rossel, H., carbide theory of .volcanism _ _ _ _ _ _:___ 230

Roth, .T., predazzite_______-_- 489 

Rothpletz, A., oolitic sand____ 471 

Romnania, salt lakes of________ 132 

Rousseau, G., artificial diamond___ 264 

Roux, , water analysis cited- 129 

Rowlanditc _ _ _ ______________ 618

Rubidium, distribution_________ 19 

in sea water____:___ ____ 92, 95

Ruff, 0., iron hydroxides_______ 453 

Rumbold, W. R., tin deposits_____ 593 

Rumpfite _____ _ ____ ___ 331

Russ, F., aluminum hydroxides___ 422

Russell, 1. C., adobe soil_______ 432

calcareous tufa __ 471

disintegration of rocks _ 415

gypsum _____________ . 183

Lake Lahontan ________ 118

14399 Bull. 330 08 45

PageRussell, I. C., residual clays____ . 480> 

Rust. See Fischer and Rust. 

Ruszanda, Lake, analysis of water- 132, 1377 

Ruthenium _____ _______ 18, 607-611

Ruthorford, E., radio-activity____ 260> 

Rutile__________________ 288, 29O 

Rutley, F., novaculite ______ 464 

Ryba, F., chromite deposit______ 605> 

Rzehak, A., mercury deposits____ 57T

S.

Saale, River___________ 7S

Sabatier, P., and Senderens, -.T. B.,

synthetic hydrocarbons- 629> 

Sacc, F., niter in Bolivia______ 208, 209" 

Sachs, A., kleinite___________ 573: 

Sacramento River, analysis of w.atw 7O 

Sadtler, S. P., distillation of linseed

oil______'. ___ 630' 

natural gas ____________ 621 

Saemann, L., and Pisani, F., alteration of cancrinite__ 311 

Safflorite _____ _____________ 599

Safford, T. M., phosphorite_____ 449 

Siihlbom, N., analysis by_______ 374 

Sainte-Gilles, L. P. de. Sec Hautefeuille and Sainte 

Gilles____-_____ 328

St. Lawrence River, analyses of

water____-_____ 61

flow of _______________ '-62 

Saladillo, Rio, analysis of water__ 74, 126 

Salic minerals __________ 358

Salisbury, R. D., mineral matter in

the sea_ ______ 97.

See «.lso Chamberlin and Salisbury. 

Salite ____- _______________ __ . 314'

Salomon, W., occurrence of spine!_ 280' 

Salsomaggiore, water of, analysis__ 142 

Salt _________________ 183, 184, 185-

Salt beds, origin__________ 175, 176. 

Saltet, R. H., and Stockvis, C. S.,

cited_____^_____ 87' 

Saltpeter ____________ 205, 207, 208 

Salt River, analysis of water____ 69 

Salvador), R. Sec Nasini, R. 

Samarium __ _____ 19' 

Samarskite ________________ 61<> 

Sand _________' _____ _ 42G-428-

Sandberger, F., analyses by____ 153 

lateral secretion. - ______ 542,543-

platinum in limonite__I___ 610' 

serpentine __ ______ 519' 

Sandstone _______________ 459-464 

average composition______ 27, 30' 

Sandstone reefs_____________ 460' 

San Lorenzo River, analysis of water ________L ____ 70>

San Romfln, F. T., water analysis_ 12<> 

Santa Clara River, analysis of

water_________ 70

Santa Ynez River, analysis of water 70' 

Saponite ________ _____ 349

Sa propel _________________ 63&
706 INDEX.

Page.

Sarasin, E. See Friedel and Sarasin. 

Saratoga waters, analyses.____ 144, 145 

Sar'deson, F. W. See Hall and sardeson.

Sarkinite_:_______________ " 598 

Sartorite ________________ 585, 586 

Saskatchewan River system____ 71 

Sassolite ________________ 196 

Sauer, A., alteration of leucite to

analcite_________ 307

graphitoid______________ 657

kryptotile _____________ 527

Sa'ussurite ___________ 341, 512, 513

Savage, T. E., peat__________ 648

Savu-Savu Spring, analysis of____ 144

Saxonite ________________ 390, 391

Saxony, mineral waters of______ 151

Saytzeff, A., Uralian platinum___ 609

Scacchi, A., fluorite on lavas____ 274

leucite pseudomorphs _ 307

sublimed silicates_________ 223

Vesuviau sublimates_______ 221

Scandium ___________ _ 19

Scapolite _______________ 337-339

Scapolite rocks____________ 514, 515

Scarpa, 0., radioactivity of lava__ 259

;Scbafhaiitl, P., synthesis of quartz_ 295

;Scballer, W. T., analyses by____ 530

formula of dumortierite___: 345

molybdic ocher__________ 605

iSchaller, W. T., and Hillebrand,

W. F., lawsonite___ 345 

Sec also Hillebrand and Schaller.

Schapbachite 562, 585 

Scharizer, R., composition 'of tourmaline--________ 346 

constitution of hornblende___ 321 

Scheelite _______________ 606, 607 

Scheerer, T., formation of dolomite- 485 

of magnesian carbonates_ 482 

Scheererite _________ . 624 

Schefferite ________________ 314 

Schenck, A., chloritization_ ___ 518 

copper ores_____________ 568 

epidotization _______ 341, 515, 516 

Schertel, A., melting points of min--

erals __________ 238 

See also Stelzner and Schertel.

Schertelite _______________ 444 

Schickendantz, F., cited______-.- 189 

Schiebe, 0., gold in olivine rock___ 553 

Schilling, J., distribution of thorium- 617 

Schinnerer, L., and Morawsky, T., 

pyrocatechin from lignite ___________ 668 

Schirmerite ___________-__ 562, 585 

Schlagintweit, H. von, Tibetan borax____________ 202 

Schlosing, C., sedimentation ___ 429 

Schloesing, T., ammonia in atmosphere ' ' 46 

ammonia in sea water 92 

analyses of sea water- 94 

oceanic carbonic acid 112 

plasticity of clays 425

Page. 

Schloesing, -T., solubility of calcium

carbonate _._____!__ 98

solubility of calcium phosphate- 442

tropical soils___________ 423

Schmelck, L., analyses by__ 94, 371, 372

marine clays_______._____ 107

marine muds_____ _ 438

Schmidt, C., chamosite________ 494

sericitic rocks_________ 511

Schmidt, C. (Dorpat), water analyr

ses __ 81, 94, 95,128, 130, 132 

fumaroles of Monte Cerboli- 196, 197 

Schmidt, R. E. See Lunge, G. 

Schmidt, W. B., action of sulphurous

acid on rocks_____ 408 

Schmitz, E. J., copper in fossil wood- 566 

Schmutz, K. B., artificial scapolite

rock ___________ 338

formation of tridyinite______ 296

fusion of mineral mixtures____ ' 252

Schnarrenberger, C., analyses by__ 539

Schneider, E. A., analyses by____ 162,

390, 412, 463, 466, 524

See also Barus, C.; Clarke and

Schneider.

Schneider, J., water analysis____ 132

Schneider, K., origin of perofskite_ 288

Schneider, 11., cubanite______.._ 567

precipitation of silver sulphide- 561

synthesis of emplectite_ ___ 570

of wittichenite_____.__ 570

of greenockite ______ 578

of matildlte__________ 563

Schodler. See Petersen and Schod-'

ler. .

Schoeller, water analyses_ -- 74 

Schoenite _________________ 178 

Schorlomite______________ ' 335 

Schrauf, A., kelyphite________ 336 

mercury ores __^___ __ 576, 577 

mine 'waters____=______ 546 

serpentine from garnet_____ 520 

Schreibersite _______________ 269 

Schreiner, O., and Failyer, G. H., absorbent power of soils. 425 

See also Kahlenberg, L. 

Schrb'ter. See Friih and Schroter. 

Schrotterite ____________'.- .__ 527 

Sc-hiiler, E., synthesis of greenockite- 578 

Schiiler, G., chromium in a phosphate__________ 446, 447 

Schiitzenberger, P., volatility of silica _._______.,___ 223 

Schulten, A. de, synthesis of analcite 305 

synthesis of gibbsite___.___ 421 

of lanarkite _________ 588 

of laurionite_________ 587 

of malachite_________ 572 

of molybdenite________ 605 

of northupite and tychite 200 

of phosgenite__ 587 

Schultze, H., synthesis of wulfenite- 589 

Schulze, H., and Stelzner, A., artificial tridymiteJ____ 296 

artificial willemite_______.._ 581 

Schumacher, A., cited _ _ __ 434 

Schunett, Lake, analysis of water. 131,136
INDEX. 707

Page.

Schungite ________________ 657

Sob wager, A., analysis by _:__._ 441

on the waters of Bavaria__ 78, 79, 80

. Schwantke, A., artificial tridymite 296

osteolite and staflelite_____ 443

Schwartz, E. H. L., African hot

springs_ 168 

Schwartzembergite 587 

Schweig, M., ^maginatic diffierentia-

'tiou___________ 258 

Schweinfurth, G., and Lewin, L., 

origin of alkaline carbonates_______ 194 

Schweitzer, P., analyses by_____ 142,

146,149,150

'Scolecite _________________ 349 

Scorodite ________________ 596 

as a spring deposit 163, 164 

Serivenor, J. B. See Reid and Scrivenor.

Seal, A. N., ozokerite__________ 625 

Searnon, W. H., analyses by____ 555 

tallow clays___________ 583 

Secondary enrichment. __ 552, 569 

Sedimentary rocks__ ____ 459-500

average composition ____ 27,30,31

volume of______ _____ 28-31

Sedimentation_____________ 429, 430

Seidell, A., water analysis_____ 70, 120

Sec also Cameron and Seidell. 

Seine, River, analysis of water___ 76 

Selenite. See Gypsum. 

Selenium, distribution :____ 19

Sfclensulphur____.___________ 220 

Semper, E., and Blanckenhorn, M.,

origin of nitrates___ 209 

Scraper and Michels, Chilean nitrates 206 

Semseyite ________________ 585 

Scnarmont, H. de,. precipitation of

silver__________ 559

reduction of copper __ 566

synthesis of chalcopyrite____ 567

of pyrargyrite and proustite 562

of pyrite___________ 272

of quartz__:_________ 295

of realgar, stibnite and bismuthinite _______ 596

r of sphalerite _______ 578

sulphides of cobalt and nickel- 599,. 600

Senarmontite' _____________ 598

Senderens, J. B. Sec Sabatier and

Senderens.

Sericitc ______________ 326, 510-512

Serpentine____1_______ 348..519-523

Sestini, P., solubility of minerals__ 403

Sevier Lake, analysis of water____ 120

deposits from __________ 188

'Seybertite _I_______ ____ 327

Shale__________________ 467-469

average composition- _____ 27, 30

Shaler, N-. S., bog iron ore-___ ___ 452

peat ____ _ _ _______ . 645

phosphorite _-__ _____ 449

soils ________________ 431 

Shales, metamorphosed ___ 524-525

Page.

Sharpies, S. P., coral_________ 476 

phosphate rock____ ___ 444

solubility of calcium phosphate. 442 

feharpless, P. P. See Lane and

Sharpless.

Sheep Creek, analysis of water___ . 72 

Shepard, C. U., phosphate rock___ 445 

Shepard, C. U., jr., phosphate rock_ 444 

Shepherd, E. S. See Day and Shepherd.

Sherzer, W. H., celestite_______ 497 

Shiraz, salt lake near, analysis of 

water_________ 130, 134 

Shoal Creek, analysis of water 146, 147 

Shonkinite___.______,____ 371, 372 

Shonkinose ________________ 372 

Shoshonose_______ 380, 383, 384, 385 

Sibirtzew, N., soils______ __ 431 

Sickenberger, E., formation of petroleum _________ 636 

origin of alkaline carbonates_ 194 

Sldener, C. P., analyses of water_ 64, 

65, 66, 71, 141

Siderite __________ 351, 452, 490-492 

Siclerophyllite___________-__ 327

Sidot, T., synthesis of galena____ 584 

synthesis of greenockite and

wurt/ite ___________ . 578

of magnetite .__ 283 

of troilite ___________ 272 

of zincite___________ 580 

Siebenthal, C. E., limestone- __ 478 

marl__________________ 472 

Siedentopf, IT., "color of salt_____ 185 

Siemens, E. W. von, volcanic explosions __________ 236 

Siepmann, P., constitution of'coal_ 667 

Siewert, M., water analysis____ 74, 126 

Silber, P. G. Sec Gorgeu and Silber. 

Silica, in river waters_ ' _ 84 

in sea water__ 92 

volatility of____________ 223 

Silicates, hydrolysis of_________ 151 

solubility of___________ 100, 102 

Siliceous sinter__ 161, 162, 163, 164, 465 

Silico-azo-humic acid____ 83

Silicon, distribution 19

Sillimanite______ 343, 344, 527, 528

Sillimanite schist____________ 530

Silt___1________________ 428, 430

Silva, A. P. de, and d'Aguiar, A.,

fluorine in spring

waters ____ ___ 149

Silver, distribution __________ 19

in native copper __ __ 565

in sea water 93

in volcanic ash '. ___ 221

occlusion of oxygen by __ 235

ores of-_________ _ 558-564

Silver Islet, analysis of water from_ 144 

Silver, L. P., nickel deposits____ 601 

Silyestri, 0., fluid inclusion in sulphur __________ 497 

hydrocarbons in lava__ 230, 231, 632 

iron nitride____;___ _ 222
708 INDEX.

Page.

Silvestri, 0., volcanic gases_ 216 

Simmersbach, B., and Mayr, F., nitrate deposits_____ 207 

Simpson, E. S., native tin______ 591 

Singer, M., constituents of wood___ 643 

Sinter, barytic ____________ 160,498 

Sinter, calcareous _________ 159, 160

Sinter, ferruginous ______ __ 491 

Sinter, siliceous __ 161, 162, 163, 164, 465 

Sipoez, L., analysis by_____ 441

krennerite __________ 555

Siserskite ________________ 607

Sjogren, H., bog-iron ore__ 452

fluid inclusion in sulphur____ 497

vesuvianite _ _ 337

Sjollema, B., perchlorates in soda

niter___________ 208 

Skeats, E. M., acid water from sulphur beds _______ 497

Skeats, E. W., coralline limestone_ 476 

magnesia in coral reef______ 487

phosphate rock________ 451

Skey, W., analyses by__ 142..149, 153, 156 

awaruite ______________ 269 

gold sulphide____'.__________ 554

precipitation of gold______ 558 

of silver sulphide______ 561 

solvents of gold__________ 557 

Skinner, W. W., underground waters

of Arizona_______ 154

See also Forbes, R. H. 

Skutterudite ________________ 599 

Slate ___________ 467-469, 524,' 525 

Sloan, B., clays_________'____ 431 

Slosson, E. E., water analyses__ _ 67, 126 

Smaltite________________^_ 599, 601 

Smart, C., water analyses______ 119 

Smith, A. W. See Mabery and

Smith.

Smith, B. H. See Haywood, .T. K. 

Smith, B. A., phosphate rock_'____ 450

Smith, F. D., tungsten ores______ 607 

Smith, G. O., molybdenite______ 606 

Smith, .T. L., analysis by___ _ ' 145 

native iron_____________ 268 

Smith, J. P., eclogite_________ 517 

glaucophane rocks _______ 323, 509 

lawsonite rocks__________ 345 

Smith, R. A., oxygen of the atmosphere __________ 39 

peat ___ ____________ 645

Smith, Watson, resins in lignite. 651 

Smith, W. S. T., zinc deposits____ 583

See also Ulrich and Smith. 

Smithite _________________ 562 

Smithsonite______________ 580, 581 

Smoky Hill River, analysis of water. 68 

Smoot, L. E., analysis by_______ 155 

Smyth, C. H., alteration of pyroxene___________ 313,314 

. Clinton iron ores_____ __ 453 

corrosion of quartz___ 300 

losses of atmospheric oxygen__ 51 

melilite rocks ___________ 334 

talc_____________ 349, 521, 522 

Smyth, H. L., iron ores___ 284

Page.

Snake River, analysis of water__ 70 

Soap Lake, analysis of water__ 125, 137 

Soda Lake, soda from_ ________ 191 

Soda Lakes, analyses of water__ 123,137 

Sodalite________.________ 309-311 

Sodalite syenite_____________ 378

Soda niter______ 200, 202, 206-208, 211

Sodium,- distribution__________ 1!)

metallic, in salt__________ 185

sulphate deposits_____ 186, 187, 188 

Sodium chloride, in rainfall-____ 47

See also Salt.

Soellner, J., rhoenite__________ 323

Soils______ 415, 416, 417, 423, 424, 431

Sokoloff, N. V., origin of petroleum.- 632

Sollas, W. J., chert and flint_____ 465

order of deposition of minerals- 252

quartzite ____________1_ 524

radium and geology________ 260 

Solomon River, analysis of water_- 68 

Soltmann, R., melanite________ 335 

Solubility of minerals________ 403-408 

Sommerfeldt, E., classification of igneous rocks_______" 358 

Sommerlad, H., ' synthesis of chalcostibite________ 570

synthesis of sulphosalts_____ 563

sulphosalts of lead _______ 586

Sommermeier, E. E., coal analyses 650,

* 653, 656

Sonde"n, K., cited_^__________ 45

Sonnenschein, F. L., amalgam___ 555

Sonstadt, E., caesium and rubidium

in sea water________ 92

gold in sea water_________ 93 

iodine in sea water_______ 91

Sorby, H. C., calcite and aragonite_ 473 

formation of magnesium carbonate _____-_____ 482 

of siderite and limonite__ 490 

magnesium sulphate in gypsum_ 481 

shale__________________ 469 

Soret's principle____________ 254

Souesite_______--________ 209, 270 

Spaeth, E., water analysis ____ 77 

Spalding, E. P., Terlingua mines___ 573 

Spaulding, I-I. S. See Barr, W. M. 

Spencer, A. C., magmatic' waters-- 168, 547 

Spencer, Herbert, nature of earth's

interior__________ 52 

Spencer, J. W., bauxite_____ __ 420 

Spencer, L. J., jamesonite______ 586

tellurides _____________ 555 

See also Prior and Spencer. 

Sperry, F. L. See Penfleld and Sperry. 

Sperrylite ____________ 607, 610, 611 

Spessartite_______________ 335, 336 

Spezia, G., formation of quartz and

opal ___________ 299

solubility of quartz________ 406

sulphur deposits _ _ __-. 496

Sphserite L____, 443

Sphserocobaltite __.__________ 602

Sphalerite ______________ 578-584

Sphene___________ ___-__ 288

Spiegel, L., fichtelite __ 648
INDEX. 709

 Page.

Spielman.n, P., jet___________ 649 

Spilker, A. Sec Kriitner and Spilker. 

Spinel _________________ 578-584 

Spirek, V., mercury ores______ 577

Spodumene ____._'. ____________ 315, 594

Spreusteln.________________ 311 

Spring, W., augentite formed by pressure__________ 560,561 

coloration of clay_________ 432 

compression of chalk______ % 477 

of peat ____________ 663 

humus and iron In waters.- _;. 453 

precipitation of organic matter

by iron ________ 430 

sedimentation ___________ 429 

Urallan platinum__________ 609 

Spring, W., and Prost, E., .water of

the Meuse_______ 75, 90

Springs, potable, analyses of_____ 57 

Spurr, J. E., alaskite and tordrillite____________ 366 

berates _______________ 199 

dolomitization___________ 488 

glauconite _____________ 492 

iron ores ________'.______ 491

magmatic quartz veins.____ 554 

ore deposits___________ 541, 548 

primary pyrrhotite_ ___ 273 

scapolite rocks.__________ 5J.5 

succession of igneous rocks_____ 256

Srebenica, spring, analysis_____ 146

Staffelite _________________ 443 

Stnhl, A. F., origin of petroleum_ 638 

Stahl, W., on Karaboghaz ____ 127 

Stanley, F. C. See Penfleld and Stanley.

Stannite_________________ 591 

Slapff, F. M., bog-iron ore______ 452 

Stassfurt salts____________ 176-182 

Staurolite _________ 344, 345, 528, 529 

Steamboat Springs, analysis of-__ 145 

Steatite ________________ 349, 522 

Steelier, E., carbide theory of volca,nism _________ 230 

Steenstrup, K. J. V., graphite in

basalt______ 267, 268, 269 

Steiger, G., analyses by 70, 125, 144, 150, 

159, 16.1, 185, 374, 382, 

389, 427, 432, 438, 450, 

468, 479, 488, 489, 492, 

493, 514, 522, 580, 531 

solubility of minerals______ 405 

See «/so Clarke and Steiger. 

Stein, G., formation of quartz___ 297 

fusion of quartz and silicates_ 240 

Stein, S., artificial coal______ 664, 665 

Steiamann, G., precipitation of calcium carbonate __'___ 472 

Stella, A., nickel-iron__________ 269

See also Franclii and Stella. 

Stelzner, A., artificial gahnite____ 531 

associates of perofskite____" 288 

Bolivian tin ores_______ 591,595 

melilite rocks___________ 334 

See also Schulze and Stelzner.

Page. 

Stelzner, A., and Schertel, A., tin

in blende________ 591

Stelzner, A., and Schulze, H., fayalite iu slags_-_____ 324

Stelzner, A. W., lateral secretion. 542, 543

on Rio Saladillo__________ 126

ore deposits __________ 541

StSp, J., and Becke, F., uranium

ores ___________ 613 

Stephanite_______________ 562, 563 

Stercorite _,._____________ 444

Stcrnbergitc _______________ 562 

Sterrett, D. B. See Pratt and Sterrett.

Stevenson, .T., primitive atmosphere- 50 

Stibiconite ______:_________ 598 

Stibnite_______________ -. 595-597 

Stilbite ._ ________________ 349 

Stilpnomelane.____________ 331

Stockvis, C. S. See Saltet, K. 11.

Stober, F'.,' synthesis of cotunnite__ 587

Stokes, H. N., analyses by_____ 27,

57, 1.48, 307, 368, 370, 372,

373, 37G, 379, 380, 385, 388,

389, 398, 463, 468, 479,

510, 526, 531, 535, 546

formation of copper sulphides_ 569

of sphalerite_________ 582

precipitation of copper. 565

of lead sulphide______ 585

pyrite and niarcasite_____ 273

solution and deposition oi silver________.. 560, 561 

solution of gold __ 557 

tallow clay_________..___ 583 

Stoklasa, J.,. volcanic nitrogeu 222 

Stolba, F., on the Moldau______ 78 

synthesis of galena. __ 584 

Stolzite _____________ 588, 589, 606 

Stone, C. H., analyses of water 64, 124 

Mississippi silt___________ 428 

Stone, G. H., asphalt.__ 625 

Storer, F.. H. See Warren and

Storer.

Storms, W. T-T., borate deposits___ ' 200 

Strecker, A. and H., gytje__ _ 438 

Strong, A., bauxite_____' .__ 420 

Strengite __________________ 443 

Strigovite ________________ 331 

Stromeyer, C. E., effect of pressure

on fusibility ______ 238

Strontium, distribution of______ 19, 498

in sea water.. _ 92

Strutt, R. J., radioactivity of

rocks __________ 19, 259 

Struvite ___ . 444 

Stubbs, W. C., phosphate rock____ 450 

Stutzer, A. and Hartleb, R., bacterial 

decomposition of ce- . ment. ___ __ 410 

Stutzer, A., and Reich, A., water

analysis cited 129 

Stutzer, 0., cobalt ores - 598

kaolinite 416

magnetites of Lapland __.___ 284 

Stutzite __________________ 562
710 INDEX.

Page. 

Stylotypite ____ ___________ 569

Suess, E., vadose and juvenile

waters _ __ _ 168 

volcanic additions to oceanic

salts _____!_____ 109 

Sullivan, E. C., copper sulphides 569 

deposition of copper- 572 

partial analysis by______ 438 

Sullivan, G. see Eastle, J. IT., etc. 

Sulphates, reduction by microorganisms _____ 87, 116, 438, 496 

Sulphates in sea water..._____ 106, 107 

Snlphoborite _____________ 180, 202 

Sulphohalite _____________-_ 199 

Sulphur, distribution___ . 20 

in atmosphere_________ 41 

in petroleum_________ 624

Sulphur, native___ 177, 220, 495, 496, 497 

Sulphur Bank, analyses of waters

from________r-r--- 154 

Sulvanite-________________ 613 

Sungi Pait, Brook, analysis of water_ 156 

Superior, Lake, analysis of water___ 61 

Susquehanna River, analysis Of

water ___ ___ 63 

Svanberg : analyses by__ 608 

Svedmark, B., uralitization ______ 508 

See also Tornebohm and Svedmark. 

Svendsen, S., analyses of dissolved

air ____________ 111 

Sweden, rivers of_____ ___ 81 

Swinton, A. A. C., occlusion of gases

by glass____,____ 226 

Switzerland, lakes of_________ 76 

Syenite____________ ___ 370-373 

Syepoorite. See Jaipurite. 

Sylvanite_ 555 

Sylvinite __________________ 179 

Sylvite___________ 179, 180, 181, 182 

Syngenite ______________ _ 181 

Syntagmatite ________________ 321

Syracuse, N. Y., brine, analyses of 141 

Szab6, ,T., primary iolite______ 339 

.Szftdeczky, J. von, bauxite______ 420 

Szajnocha, , origin of petroleum- 635

T.

Taal Volcano, analyses of water

from ___________ 156 

Tachhydrite ____:_________ 178, 180 

Tacke, B. See Minssen and Tacke. 

Tagar, Lake, analysis of water 131, 135 

Tahoe, Lake, analysis of water _ 122 

Takano, S. See Mabery and Takano.

Talbot, J. H. See Binney and Talbot. 

Talc __________- ___ 349, 519-523 

Tallow clay______________ 583 

Talmage, J. F., water analyses____ 119 

Tamentica, Lagoon, analysis of

water_________ 126,135 

Tanatar, S., origin of alkaline carbonates ___ _ 194 

Tantalite ________________ 616

Page.

Tantalum ______________:__ 20 

sources of______:_____ 616, 617

Tapajos, River, analysis of water__ 73, S3 

Tapalpite _________________ 562 

Tappeiner, H., formation of marsh

gas__________ 633,63-4 

Tasmanite __.______ ________ 650

Tate, N., analysis.of water__+ ___ 61 

Taylor, F. W., analysis by______ 184 

Tajlor, H., analysis of cannel____ 654 

Taylor, R. A., cited__________ 108 

Taylor, W. H., analysis of water__ 63 

Teall, .T. ,T. H., classification of*

igneous rocks____ 358 

dedolomitization _________ 538 

eutectic mixtures in rocks__ 248,

249, 356 

origin of serpentine__ ____ 348

phosphatized trachyte______ 444

the Scourie dike___,___ 507, 508

Teallite ________________ 586, 591

Tehamose _______________ 36T

Teisseyre, W. See Mrazec and Teisseyre. 

Tekir-Ghiol, Lake, " analysis of

water_________ 132,134' 

Tellurides ________~. ___________ 555,

556, 567, 573, 584, 595, 599

Tellurium, distribution________ 20

in copper_____________ 567

Tengerite ____-_____________ 618

Tennantite ______________ 562, 570 

Tenorite_________________ 221,571

Tephroite_________________ 324 

Terbium______________'___ 20 

Terlinguaite _______:_______ " 573 

Termier, P., lawsonite_________ 345 

ieverrierite _ _ _ _ _^_______ 527

optical variations in zoisite__ 340

rieheckite rocks_________ 323

Terreil, A., artificial dolomite____ 481

native platinum______:____ 608

water analyses__________ 129

Tetradymite _ _ _ _ ___________ 595

Tetrahedrite ______________ 562, 570 

Thallium, distribution_______"_ 20 

Thames, River, analysis of water__ 76, 83 

Than, C. von, ionic statement of

water analyses____ 54

Thenard, P., azohumic acid_____ 409

silico-azo-humic acid_______ S3

Thenardite ______________ 187, 199

Theralite- _ _ _ _____1_______ 375

Thermonatrite_"_______: ____ 191

Thiele, F'. C., Texas petroleum____ 622, 

Tbinolite----____________ 122, 123

Thiophanes _ _ _ _ ____________ 624

Thiosulphates in spring waters___ 152 

Thorite _________________ 617

Thorium, distribution_________ 20

sources of_____________ 617

Thorogummite______________ ' 618

Thorpe, T. E.. analyses by__ 143, 145,146 

Thorpe, T. E., and Morton, E. H.,

analysis of sea water- 94 

Thoma, , gases in iron 234
INDEX. 711

Page.

Thomas, J. W., gases in coal____ 660, 

. 661, 662, 663

Thomas, P., phosphorite ______ 418 

Thompson, A. B., formation of bitumens^---______ 638 

Thomson, J., thermochemistry of sulphide's _-________ 561 

Thdmsonite _______ !________ 349

Thoulet, J., chert___________ 465 

desert sand__________ 427 

lakes of the Vosges______- 76 

sedimentation _ _ _ _ _____1__ 429'

solubility of calcium carbonate- 98 

of silicates_______ 102 

Thresh, M., manganese nodules___ 455* 

Thiirach, H., occurrence of zircon 

and titanium minerals-.--_______ 290.-292 

Thugutt, S. .T., alteration of corundum __________ 278,400

composition of sodalite___ 309, 310

glbbsite and diaspore___-__ 422

leucite and analcite______ 305, 306

' Thulium___________________ 20

Thuringite -____________ 331, 493 

Tiemannite __'_ -- .___________ 573

Tietze, E., atmospheric transport of

salt ___________ 48

Tietze, 0., phosphorite.____ _ 448

Tilden, W. A., gases in rocks__ 225, 226

Tin, distribution ______'_ 20

ores _____________. 591-595

Tinetzky Lake, analysis of water. 128, 136 

Tinguaite___________ 373, 376, 378 

Tinstone. See Cassiterite. 

Titanite __________________ 288 

Titanolivine ______________ 324 

Titanium, distribution_________ 20 

Tb'rnebohm, A. E., melilite rocks 334 

TSrnebohm, A. E., and Svedmark,

B., scapolite rocks_._ 514 

Tornebohm, A. S., enlargement of

quartz grains_____ 460

Tolman, C. F., jr., oceanic carbonic

'acid____________ 114. 

Tolomei; G., iron bacteria _ _ 453 

Tonalite __^_____________ _ 384 

Tonalose________________ 382, 388 

Tookey, C., analyses by___ 646, 649, 651 

Topaz_________________ 342, 344 

Torbanite _________________ 637 

Tornoe, H., density of sea water___ -96 

analyses of dissolved air_..._ 111 

Torrico y Meca, vanadium in coal_ 612- 

Torrey, J. See Barbour and Torrey. 

Toscanose________ 367, 368, 369, 380 

Tourmaline___ -_____,._-i___. 346, 347

Tourmaline schist__________ 532, 533 

Trachyte _______________ 370-371 

Transition temperatures_______ " 242 

Transvaalitc ______________._' 602

Traphagen, W., cited _,__ _ _ 66

Tcaube, H., sublimation of minerals- '223

synthesis of beryl____-___ 347

of rutile-__________ 289

wurtzite as furnace product__ 578

Page. 

Traube, H., zincite___________ 580

See also Bourgeois and Traube. 

Traunsee, analysis of water_____ SO 

Travaglia, R., formation of sulphur

deposits- _ -. 496 

Travers, M. W., gases from meteorites__________.__ 234 

gases from minerals and rocks 225, 226 

Travertine_______ 159, 160, 471, 481 

Treadwell, F. P., and Renter, M., 

solubility of calcium 

bicarbonate_____ 99 

Trechmann, 0. 0., pseudogaylussite_ 123 

Tremollte ____________,__ 318-319 

.melting point____. __'____ 240 

Tridymitc ________________ 294-300 

Trinkerite _______________ 650 

Triphylite _________________ r>93 

Tripuhyife -_________..____ 598

Trobritlge, F. G., gases in coal___ 663 

Troillte __________________ 271, 272 

Trona __^______ 191,192,193,199,200 

Troost, L. See Deville and Troost. 

Troost, L., and Hautefeuille, P.,

gases -in iron ___ 234 

Truchot, P., monazite, thorite, and

zircon_____ L _____ 294

Truckee River, analysis of water__ 122 

Tschermak, G., alteration of atacamite____._____ 571 

carbon in meteorite______ 632

constitution of pyroxenes____ 318 

composition of tourmaline__'_ 346 

gaseous occlusions______ 234, 235 

scapolite group _____ 337, 338, 514 

serpentine _______________ 519

theory of chlorites_______ 331, 332 

of micas ___________ 328 

Tscbirwinsky, W., podolite ______ 293 

Tsuneto, K., Japanese phosphates_ 451 

Tucker, G. P. See Pemberton, H. 

Tufa, barytic _______________ 160 

Tufa, calcareous ____________ 471 

Tulare Lake, analyses of water_ 124, 137 

Tungsten, distribution__________ 20 

ores _____________.__ 605-607 

Tungstic ocher_____________ 606 

Tuolumnose____________ 370

Turgite ..______________ 451

Turner, H. W., California diamonds- 265 

quartz-alunitc rock ____ _ 421

Turquoise -_________ __ 443

Tuscarora sour spring, analysis _ 155 

Tyrolite___________________ 570 

Tychite ____________________ 200

Tyrrell, J. B., native iron______ 270 

Tysonlte __________________ 274

U.

Tfintaite.1________________ 624, 625 

Ule, W., the Mansfelder lakes____ 80 

Ulexite _______1 198, 199, 201, 202, 203 

Dike, T., tin deposits______ __._ 594

Ullik, F., on the Elbe_________ 78 

Dllmannite ________________ 599
712 INDEX.

Page. 

Ulrich, E. O. See also I-Iayes and

Ulrich. 

Ulrich, E. O., and Smith, W. S. T.,

fluorite________ 500 

Ulrich, G. I-I. F., awaruite______ 269 

Umangite ________________ 567 

Umlauff, A. F., mercury deposits__ 577 

Umptekose _______________ 374.

Unakite ________________ '265, 516 

Uralite ________________ 319, 508 

Uralitization______________ 507, 508 

Uralose __________________ 393 

Uraninite _______________ 613-615 

Uranium, distribution_________ 20 

ores ofl_____________ 611-616 

Urao. See Trona.

JJrbain, G., rare earths in fluorite_ 274 

Urmi, Lake, analysis of water__ 130, 134 

Urti'te __________________ 374, 376 

TJrtose __________________ 374, 375 

Uruguay River, analysis of water_ 74, S3 

silica in________________ 84 

Usiglio, ,T., concentration of sen

' water ______ 173, 174, 175

Ussing, N. V., alteration of arfvedsonite __ _______ 323 

Utah, waters of_____________ 119 

Utah Hot Springs, analysis____ 142 

Utah Lake, analyses of water___ 120 

Uvaldose ________________ 387 

'.TJvarovite ________________ 335

Vaalose ____________

Vadose waters__________-

Valentin, .T., nuorite_______

Valentine, W., analysis by. 

'Valentinite _____________

389 

168

.__ 500 

_ 398 

.!_ 598

Van, Lake, analysis of water___ 130, 137

Vanadinite _____________ 589,590

Vanadium, distribution________ 21

in bauxite ______________ 423

ores of_______.______ 611-616

'Van Hise, C. R., actinolite magnetite

schist __________ 319 

alterations of corundum_____ 280 

of hematite__________ 286 

amount of carbon dioxide in atmosphere-_______ 43

 average composition of clays,

schists, etc_____ 534, 535 

ferruginous schists________ 526 

fineness of sand particles____ 467

formation of iron ores_____ 491 

magmatic quartz veins_______ 554

niagmatic waters_________ 547 

mica schist____________ 531

 ore deposits_________- 541

 origin of rnagnetltc________ 284 

.porosity of sand-_ 460

 quartzite _____ ___- 524

relative proportions of sedimentary rocks__ __ __ 31 

, volume changes in alteration of

minerals. _--_ 507

Page. 

Van Hise, C. R., volume of ground

.water___________ 22 

zinc deposits.__ ______ 583 

zones in lithosphere_____ 502-505 

See also Irving and Van Hise. 

Van Horn, F. R., alkali-hornblende- 322 

Van Niiys, T. C., and Adams, B. F.,

cite'd___________ 42

Van Riesen, , analysis by___ 522 

Van't Hoff, .T. H., geological thermometer-________ 182'

on Stassfurt salts_______ 178, 179 

syntheses of borates ______ 201 

Van't Hoff, .T. H., and Barschall, H.,

on glaseritc.-____- 178 

Van't Hoff, .T. H., and Farup, P.,

marine anhydrite ___ 181 

Van't HofC, J. H., Kenrick, F. B., 

and Davvson, IT. M., 

tachhydrite _____ __ _ 180

Van't Hoff, J. H.. and Meyerhoffer,

W., on langbeinite __ 179, 180 

Van't Hoff, J. H., and Weigert, F.,

formation of anhydrite 181 

Vanthoffite ____..__..____ 178,170,182 

Van Wagenen, T., soda niter_____ 211

Van Winkle, W. See Barr, W. M. 

Variscite _______________ 443, 446 

Varvicite ______________- 456

Vasculose ________:_______ 664

Vater, H., alkaline carbonates____ 194 

artificial hematite_______ 285

calcite and aragonite_______ 473 

A'aughan, T. W., fuller's earth___ 431 

Vauquelinite ______________ 588 

Vaux, F., coal analyses______ 654, 656 

Veatch, .T. A., boron in sea water-__ 92 

Vegetation, as agent of rock decomposition _______ 408,409 

Veins, metalliferous __________ 548-552

Velain, C., artificial tridymite___ 296 

Venable, F. P., on periodic law____ 35

Venanzite _________________ 386 

Venanzose _______________ 386 

Verde-antique _____________ 520 

Vermiculite . ______________ 330, 331 

Vermilion _______________ 574

Vernadsky, W., andalusite, kyanite,

sillimanite ______ 528 

artificial corundum______ 278

calcination of dumortierite___ 346 

of topaz____________ 343

formation of sillimanite_____ 343 

of spinel ____________ 280 

fusion of mus.covite________ 330 

Vernadsky, W. S., and Popoff, S. P.,

borax ___________ 202 

Vernon-I-Jarcotirt, L. V., sedimentation ____________ 429 

Versailles alum well, analysis____ 146 

Vesterberg, A., dolomite and mo.^-

nesite________..__ 484 

vesuvianite_______________.._ 337 

Veszelyite_______ __ _____.._ 580 

Vichy, spring deposits. ___.._ . 160 

\ ichy waters, analysis_ _ ..._ 149 

Vierthaler, A., cited __________ 94
INDEX. 713

Page. 

Vlezzenose _____________ 374

Villanello, J. D., mercury ores___ 573 

Ville, L., on river Chglif ______ 59 

Vinagre, Rio, analysis of water __ JOG 

Viola, C., occurrence of lawsonite__ 340 

\iolette, , charcoal______ 663,004 

Virginia Hot Springs, analysis__. 150 

Viridite__________________ 518 

Viry phosphatic water, analysis__- 154 

Vistula River, analysis of silt 429 

analysis of water._ SO 

Vivianite ____1__________ 443, 452 

Voelcker, J. A., composition of apatite__________.._ 292 

Vogel, H., platinum in metallic ores. G.10 

Vogelsang, I-L, viridite _______ 518 

Vogt, J. H. L., anorthite in slags__ 301 

apatite in-slag _ __ 293 

augite in slags 317 

bog-iron ore____ __.._.. 452 

cassiterite as a furnace product .

291, 591

chroniite deposits _______ 282,605 

distribution of the elements.-- 20,37 

of vanadium _________ 611 

eutectic mixtures in rocks___ 249 

eutectics in classification of

rocks _________ 350

formation of hematite--____ 285

of magnetite_______ 283, 284

of pyroxene _________ 314

fusion of garnet- _ 335

gehlenite group____ ____ 333

magmatic iron ore______.__, 257

magmatic pyrrhptite _____ 273, 600 

ruagmatic waters..______._ 547 

manganese ores _ __ __... 45G 

melting points of minerals__ 239, 240 

mica in slag_________._.. 328

native silver___________ 559 

olivine in slags___________ 324

on assimilation theory____ 256 

ore deposits _ _____ 541

platinum in pyrrhotite____._ Oil 

solubility of sulphides in magmas _____ ______ 251

synthetic enstatite________ 312 

tin deposits __________.._ 593

wollastonite in slags ____ r 313 

Vohl, H., water analysis ____ 70 

Voit, F. W., nickel deposits______ 601

Volborthite _______________ 012 

Volcanic gases _ __ ___ 212-230 

Volcanic explosions,_________ 232-236

Volcanic mud and sand ___ 430, 437 

Volcanism, ascribed to radioactivity ____________ __'_^___ 259

Vouga, , origin of petroleum_ 037

VuC-nik, M., formation of augite___ 317

formation of hercynite _____ 281

of magnetite__.._____ 283

fusion of acmite_________ 315

of mineral mixtures___ 246, 252 

Vukits, B., formation of augite__ 317 

formation of magnetite____ 283 j

of spinel.-__________ 281 

. fusion of mineral mixtures_ 240, 252

W. . Page.

Wab'ash River, analysis of water _ GO

Wad ______ __ __ 455

Wadsworth, M. E., chromite____ 281

native copper___________ 565

Wagoner, L., gold and silver in

rocks _ __ _ 053 

gold in .sea water_________ 93 

Wait, C. E., antimony deposits__ 597 

Wait, F. G., analyses by_ 71, 125, 144, 149 

Wakarusa River, analysis of water'_ 68 

Walchensee, analysis of water-___ 80 

Waldeu, P., origin of petroleum__ 639 

Walker, P. H., analysis by______ 456 

Walker, T. L., magmatic differentiation _______- __ 257 

nickel deposits________ 600,601 

Walker Lake, analysis of water-. 122, 137 

Walker River, analysis of water_ 122 

Wallace, E. C. See Richardson and

Wallace.

Wallace, W., sandstones______ 463 

Waller, E., analyses by_______ 1.19, 281 

Wallich, G. C., flint__________ 465 

Walther, .T., calcareous algae____ 476 

criticism of Ochsenius _______ 175

desert salts___________' 188 

origin of graphite_____-__ 266 

laterite _____________ 417

Wanklyn, J. A., free iodine in spring-.

water __________ 142 

Ward, W. .T., analysis by_____ 649, 651 

Wardite _________________ 443 

Warington, R., absorbent power of

hydroxides ___-_ __ 425 

ammonia in rainfall_______ 46

chlorides in rain_________ 47 

decomposition of calcium'phosphate _______'__ 443 

origin of boric acid _____ 197

sulphur in the atmosphere__.. 41 

Warren, C. H., anorthite in limestone: ._________-_ 303 

iron-anthophyllite _______ 318, 326 

minerals in sancl_____ __ 427

See also Hidden and Warren. 

Warren, 0. M., and Storcr, F. II.,

artificial petroleum __ 629 

Rangoon oil _____ _ 623

Warrenite ________________ 585, 586 

Warsaw, N. Y., brine, analysis of__ 14.1 

Warth, II., classification of igneous

rocks .. 354 

'gibbsite ______________ 419

Warth, H. and F. J., laterite and

bauxite _________ 419 

Washington, H. S., alteration of biotite ____________, 330 

analyses by_____ 376, 378, 386, 510 

average composition of igneous

rocks ___________ 24-25 

glaucophane rocks________ 323. 509

leucite in igneous rocks___ 300, 376 

quantitative classification__ 364, 365 

relative abundance of minerals- 352 

See also Kunz and Washington. 

Water, influence of, on magmas _ 243, 244
714 INDEX.

Page.

Water analyses, statement of_____ 54-56 

Water glass_______________ ' 243 

Waters, classification of______134-137,

157, 158

Watson, T. L., bauxite_______ 419,420 

decomposition of diabase ____ 413 

manganese ores _________ 456 

Virginia rutile__________ 290 

zinc deposits__________-_ 583 

Watts, W. L., waters accompanying

petroleum ________ 637 

Wavellite ________________ 443 

Way, J. T., absorption of potassium

by soils__________ 424 

Wayne, E. S., analysis by_______ 142 

Weathering, belt of__________ 502 

Weber Eiver, analysis of water___ 120 

Websky, '.T., analyses of peat-____ 645 

gas from peat-__________ 660 

Webskyite ________________ 348 

Websterite _______________ 390 

Websterose ______!_________ 390

Wedd, C. B., barytic sandstones-__ 461 

Wedding, H., and Fischer, T., gases

in iron__________ 234

Weed, W. IT., copper ores ______ 568

gold in igneous rocks_____ 271

iron sinter______________ 491 

on siliceous sinters _____ 161, 162 

ore deposits ________ 541,548

secondary enrichment ! ______ 552 

tin deposits____________ 594 

travertine _____________ 471 

Weed, W. IT., and Pirsson, L. V., alteration of leucite to 

analcite _________ 307 

origin of corundum____:___ 278 

orpiment and realgar ______ 596 

Weeks, F. B., tungsten ores_____ 607 

Weeks, J. D., manganese deposits_ 456 

Weems, J. B., lead and zinc in limestones _____:__ _ 582 

Wehrlite---_____________ 390, 595 

Wehrlose-----_____________ 390

Weibull, M., formula of iolite_____ 339

vesuvianite_ ___________ 337

Weidman, S., iron ores______ 491 

Weigand, B., serpentine_______ 519 

Weigel, O., solubility of sulphides__ 545 

Weigert, F. See Van't Hoff and

Weigert. 

Weingarten, P. See Jannasch and

Weingarten.. 

Weinschenk, E., constitution of pyrite____________ 273

garnet group ___________ 335 

nickel ores ____________ 601

nontronite_ _____________ 416 

origin of graphite _______ 266, 267 

serpentine___ __________ 519

synthesis of apatite_______ 292

of argentite__________ 560 

of chalcocite and covellite_ 568 

of cinnabar __________ 575

of galena__________ 584, 585 

of orpiment and stibnite__ 596

Page. 

Weinschenk, E., sulphides of cobalt

and nickel________ 600 

talc pseuclomorphs_______ 522

Weiss, K. E.,' chromite deposit___ 605 

Wellcome, IT. S., analysis of salt-_ 184 

Weller, A., nitrogen in petroleum_ 624 

Wells, G. M., phosphate rock __ 450 

Wells, H. L-., sperrylite________ 610 

Wells, H. L., and Penfield, S. L.,

sperrylite __ _ _____ 611

Wells, J. W., arsenic mine_ __ 597 

molybdenite _____ _______ 606 

Wellsite---_______________ 350 

Wendeborn, , mercury deposits- 577 

Wendt, A. F., tin deposits______ 595 

Wernerite---_________ _____' 338 

Werveke, 'L. van, occurrence of

chloritoid __^_____ 330

iron ores ______________' 494

Westgate, L. G., epidote-quartz rock- 516

metamorphosed limestone 539

Westphal, J., cited, on Stassfurt

salts-__ _______ 176

West Baden Spring, analysis____ 148

Wethered, E. B., oolite________ 471

Weyberg, Z., synthesis of acmite__ 315

of sodalite________ _ 310

Wheeler, IT. A., blende in lignite__ 579 

clays __________ _- 4*31

lead silicate _________ - 590 

See also Luedeking and Wheeler. 

Whewellite _______________ 644 

Whipple, G. C., cited______'. ___ 47 

Whitby well, analysis__________ 144 

White, A. F., chemical denudation_ 89 

White, I. C., grahamite________ 625 

White Island hot lake, analyses of

water_____ 150

White Sea, analysis of water_" _ 95

Whitfield, J. E., analyses by____ 67,

150, 151, 153, 155: 362,

163, 367, 382, 390, 491

Whitney, .T. D., zinc deposits. _ 583 

Whitneyite ________________ 567 

! Whittle, C. L., ottrelite schist____ 52!> 

I Wibel, E., cited_____________ 94 

i Wichmann, A., alteration of iolite__ 340 

glaucophane rock_______ _ 509

minerals in sand______ 427 

se'ricitic rocks________ __ 511 

'.Wiegand, E.' Sec Beilstein and 

j . Wiegand.

Wieland, G. R., siliceous oolite-__ '466 

Wiesbaden, analysis of.water 143 

.Wiesler, A., gold in sea water 93 

Wilder, F. A., gypsum________ 185 

Wilkinsou, C., precipitation of gold- 558. 

Will, W., and Pinnow, J., diamonds

in meteorite ____: _ 264

Willemite_________ 580, 581, 583, 584 

Williams, A., gold sulphide__ 554 

Williams, C. P., zinc in waters __ 546 

Williams, F. IT., hydrocarbons in .

iron_____________ 627

W'llliams, G. F., matrix of diamond- 265

Williams, G. H., allanite and epidote. 341

chloritization ____ 517
INDEX. 715

Page. 

Williams, G. II., corundum, emery,

and spinel_______ 278

epidotization___________ 515

occurrence of magnetite___ 284

of perofskite__'_________ 287

of pyroxenes_________ 318

of spinel ____________ 281

piedmoiatite in rhyolite____- 341

saussurite rocks________ 512, 513

serpentine from peridotite ___ 348

uralitization ___ 507

Williams, I. A., clays_________ 431

micrometric analysis of rocks 390

Williams, J., cited_______^___ 40, 47

Williams, J. F., bauxite_______ 421

pseudoleucite _______ _ 307

Sec also Brackett and Williams. 

Willis, B., calcium carbonate as a

marine precipitate _ 90, 

471,472

Willm, E., analyses by_____-.- 133,152 

Willyamite ________________ 599 

Wilm, '-, palladium gold____ 555 

Wilmington Lake, analysis of water ____J_____ 126,137 

Wilsmore, N. T. M. See Craig, A. W. 

Wilson, G. See Forclihaminer, G. 

Wiluite __^________________ 337 

Winchell, A., cosmical atmosphere-- 49 

Winchell, A. N., cbalcopyrite and

bornite _________ 567

Winchell, H. V., chalcocite_____ 569

Winchell, N. H. and IT. V., iron ores_ 491

Winkler, C., origin of nickel-iron__ 269

trona _________________ 192

uranium in coal________ 616

Winnemucca Luke, analyses of water ___________ 122, 136 

Winslow, A., zinc ores______ 582, 583 

Witter, F. M., gas well________ 633 

Wittichenite _____________"_ 569, 570 

Wittjen, B. See Precht and AVittjen. 

Woehler, F., carbon in meteorites_ 632 

gases from meteorites 234 

See also Deville and Wohler. 

Woehler, L., and Kasarnowski, color

of salt__________ 185 

Wohlerite ________________ 317 

WoW, T., volcanic gases_______ 217 

Wolfachite _______________ 599 

Wolfbauer, J. F., water of the Danube __________ 79 

Wolff, J., artificial diamond_____ . 263 

waters of Mecklenburg-_____ 80 

Wolff, J. E., Franklin zinc ores__ 584 

ottrelite ______________ 529 

Wolframite._____________ 606, 607 

Wollastonite _____________ 313, 537 

melting point ___________ 240 

Wollastonite gneiss _ 539 

Wolle, C. A., analysis of spinel___ 280 

Wood ___'______________ 642-644 

Woodward, .R. S., geodetic data__ 21, 22 

Woodward, R. W., analyses by___ 121, 

159, 162, 189, 190, 466

Page.

Wooten. See Magnenat and Wooten. 

Wright, A^ W., gases from meteorites ___________ 234 

gases in rocks_________ 225

See also I-Tawes and Wright. 

Wright, F. E., crystallized copper

and silver_______ 566

See also Alien. E. T.

Wulf, H., scapolite rock_______ 515 

Wulf, .T., wollastonite rock_____ 313 

Wulfenite _________^____ 588, 589 

Wiilfing, E. A., composition of tourmaline__________ 346 

Wurtz, FT., analysis of water____ 63 

huntilite and animikite ___ 560 

solvent of gold__ ______ 557 

Wurtzilite _________________ 625

Wurtzite ________________ 578, 579 

WyomJngite ______________ 376 

Wyomingose ________________ 376

Wyrouboff, G., Meigen's reaction__ 473

Xanthitane __________'_____ 288 

Xanthoconite ____________'_ 562 

.Xanthophyllite _____________ 327 

Xanthosiderite __________J__ 451

Xenon ___________________ 21, 38 

Xenotime_____________ 293, 294, 618 

Xingu, River, analysis of water___ 73, 8H

Yamasaki, N., piedmontite__ 341 

Yeates, W. S., copper pseudomorphs- 565 

Yellowstoue National Park, analyses

of waters.._______ 67, 

150, 151, 153, 155

spring deposits-.!-- 159, 161, 162, 163 

Yellowstonose ____________ 382 

Yeneseisk, Siberia, saline lakes___ 131 

Yogoite ___________________ 380 

Young, A. A., enlargement of quartz

grains __________ 460 

Young, B. R., analcite diabase ___ 307 

Young, G. Sec Irvine, R. 

Ytterbium __________________ 21 

Yttrialite ____,__________ 618 

Yttrium, distribution ________-_ 21

sources of ____________ 618

Yttrocerite __1__________ 274

Yttrocrasite ________________ 618 

Yukon River, analysis, of water __ 70

Zaleski, S. S., cited__________ 81 

Zalinski, E. R., thuringite and chamosite_______ 494 

Zaloziecki, R., formation of petroleum___________ 636 

mirabilite __ _ _ 181 

Zalozieck'i, R., and Hausmann, J.,

Roumanian petroleum- 623

Zamboninl, F., gehlenite group 333

sublimed galena____ __ 222
716 INDEX.

Zaracristi, 

. Zaratite__.

-, Colombian nitratesage. 

20S 

602 

663 

651

Zeiller, R., compression of peat____

paper coal______________

.Zelinsky, N., cited____________ 87 

Zemcuzny, S., eutectics________ 356 

Zeolites ________________ 349-351 

Zepharovichite _____________ 443

Zietrisikite _________________ 624 

Zilliacus, A., analysis by_______ 375 

Zilwaukie, brine, analysis of_____ 141

Zinc, distribution-__:________ 21

in sea water---______-_ 93

ores of______________ 577-584 

Zincaluminite ______________ 580

Page.

Zincite_______________ 580, 583, 584 

Zinkenite______________ __ 585, 586 

Zinnwaldite________;_____^_ 326 

Zircon _______________ 291, 292, 617 

Zircon- pyroxenes __ _ _ .__ 317 

Zirconium, distribution______ 21 

sources of ____-__ __ 617 

Zitowitsch, '-, gases in coal___ 660 

Zoisite ________._____'___ 340, 341 

Zoisite rocks__________-__ 513-514 

Zbrgite____________________ 584 

Zschimmer, E., alteration of micas_ 331 

Zuber, R., origin of petroleum____ 634 

Zulkowski, K., andalusite group__ 343 

Zurich, Lake of, analysis of water__ 77
CLASSIFICATION OF THE PUBLICATIONS OF THE UNITED STATES GEOLOGICAL

SURVEY.

[Bulletin No. 330.]

The publications of the United States Geological Survey consist of (1) Annual 

Reports, (2) Monographs, (3) Professional Papers, (4) Bulletins, (5) Mineral Resources, 

(6) Water-Supply and Irrigation Papers, (7) Topographic Atlas of United States 

folios and separate sheets thereof, (8) Geologic Atlas of United States folios thereof. 

The classes numbered 2, 7, and 8 are sold at cost of publication; the others are distributed free. A circular giving complete lists can be had on application.

Most of the above publications can be obtained or consulted in the following ways:

1. A limited number are delivered to the Director of the Survey, from whom they 

can be obtained, free of charge (except classes 2, 7, and 8), on application.

2. A certain number are delivered to Senators and Representatives in Congress for 

distribution.

3. Other copies are deposited with the Superintendent of Documents, Washington, 

D. C., from whom they can be had at prices slightly above cost.

4. Copies of all Government publications are furnished to the principal public 

libraries in the large cities throughout the United States, where they can be consulted 

by those interested.

The Professional Papers, Bulletins, and Water-Supply Papers treat of a variety of 

subjects, and the total number issued is large. They have therefore been classified 

into the following series: A, Economic geology; B, Descriptive geology; C, Systematic geology and paleontology; D, Petrography and mineralogy; E, Chemistry and 

physics; F, Geography; G', Miscellaneous; H, Forestry; I, Irrigation;- J, Water storage; K, Pumping water; L, Quality of water; M, General hydrographic investigations; N, Water power; 0, Underground waters; P, Hydrographic progress reports; 

Q, Fuels; R, Structural materials. This paper is the fifty-fourth in Series E, the 

complete list of which follows (PP=Professional Paper; B=Bulletin):

SERIES E, CHEMISTRY AND PHYSICS.

B 9. Report of work clone in the Washington laboratory during the fiscal year 1883-84, by F. W. Clarko

and T. M. Chatard. 1884. 40pp. (Out of stock.) 

B 14. Electrical and magnetic properties of the iron, carburets, by Carl Barus and Vincent Strouhal.

1885. 238pp. (Out of stock.) 

B 27. Report of work done in the Division of Chemistry and Physics-, mainly during the year 1884-85.

1886. 80pp. 

B 32. Lists and analyses of the mineral springs of the United States (a preliminary study), by Albert

C. Peale. -1880. 235pp. (Out of stock.)

B 35. Physical properties of the iron carburets, by Carl Barus and Vincent Strouhal. 1886. '62pp. 

B 30. Subsidence of fine solid particles in liquids, by Carl Barus. 1886. 58 pp. (Out of stock.) 

B 42. Report of work done in the Division of Chemistry and Physics, mainly during the fiscal year

1885-86, by F. W. Clarke. 1887. 152 pp., 1 pi. (Out of stock.)

B 47. Analyses of waters of the Yellowstone National Park, with an account of the methods of analyses employed, by F. A. Gooch and J. E. Whitfleld. 1888. 84 pp.. (Out of stock.) 

B 52. Subaerial decay of rocks and origin of the red color of certain formations, by I. C. Russell. 1889.

65 pp., 5 pis. (Out of stock.). 

B 54. On the thermoelectric measurement of high temperatures, by Carl Barus. 1889. 313 pp., 11 pis.

(Out of stock.) 

B 55. Report of work done in the Division of Chemistry and Physics, mainly during the fiscal year

1886-87, by F. W. Clarke. 1889. 96 pp. .(Out of stock.)
II SERIES LIST.

B 60. Report of work done in the Division of Chemistry and Physics, mainly during the fiscal year

1887-88. 1890. 174 pp. (Out of stock.) 

B 64. Report of work done in the Division of Chemistry and Physics, mainly during the fiscal year

1888-89, by F. W. Clarke. 1890. 60 pp.

B 68. Earthquakes in California in 1889, by J. E. Keeler. 1890. 25 pp. 

B 73. The viscosity of solids, by Carl Barus. 1891. xii, 139 pp.. 6 pis. 

B 78. Report of work done in the Division of Chemistry and Physics, mainly during the fiscal year

1889-90, by F. W. Clarke. 1891. 131 pp. (Out of stock.) 

B 90. Report of work done in the Division of Chemistry and Physics, mainly during the fiscal year

1890-91, by F. W. Clarke. 1892. 77pp. ' '

B 92. The compressibility of liquids, by Carl Barus. 1892. 96 pp., 29 pis. 

B 94. The mechanism of solid viscosity, by Carl Barus. 1892. 138 pp. 

B 95. Earthquakes in California in 1890 and 1891, by E. S. Holden. 1892. 31pp. 

B 96. The volume thermodynamics of liquids, by Carl Barus. 1892.. 100 pp. 

B 103. High temperature work in igneous fusion and ebullition, chiefly in relation to pressure, by Carl

Barus. 1893. 57 pp., 9 pis.

B 112. Earthquakes in California in 1892, by C. D. Perrine.. 1893. 57 pp. 

B 113. Report of work done in the Division of Chemistry and Physics during the fiscal years 1891-92

and 1892-93, by F. W. Clarke. 1893. 115 pp. '

B 114. Earthquakes in California in 1893, by C. D. Perrine. 1894. 23 pp. 

B 125. The constitution of the silicates, by F. W. Clarke. 1895. 100 pp. (Out of stock.) 

B 129. Earthquakes in California in 1894, by C. D. Perrine. 1895. 25 pp. 

B 147. Earthquakes in California in 1895, by C. D. Perrine. 1896. 23pp. 

B 148. Analyses of rocks, with a chapter on analytical methods, laboratory of the United States

Geological Survey, 1880 to 1896, by F. W. Clarke and W. F. Hillebrand. 1897. 306 pp. (Out

of stock.)

B 155. Earthquakes in California in 1896 and 1897, by C. D. Perrine. 1898. 47 pp. 

B 161. Earthquakes in California in 1898, by C. D. Perrine. 1899. 31 pp., 1 pi.

B 167. Contributions to chemistry and mineralogy from the laboratory of the United States Geological Survey; F. W. Clarke, Chief Chemist 1900. 166 pp. 

B 168. Analyses of rocks, laboratory of the United States Geological Survey, 1880 to 1899, tabulated by

F. W. Clarke. 1900. 308pp. (Out of stock.) 

B 176. Some principles and methods of rock analysis, by W. F. Hillebrand. 1900. 114 pp. (Out of

stock.)

B 186. On pyrite and marcasite, by H. K. Stokes, 1900. 50pp. 

B 207. The action of ammonium chloride upon silicates, by F. W. Clarke and George Steiger. 1902.

57 pp. (Out of stock.) 

PP 14. Chemical analyses of igneous rocks published from 1884 to 1900, with a critical discussion of

the character and use of analyses, by H. S.Washington. 1903. 495pp. 

PP 18. Chemical composition oi igneous rocks expressed by means of diagrams, with reference to

rock classification on a quantitative chemico-mineralogical basis, by J. P. Iddings. 1903.

98pp., 8 pis.

B 220. Mineral analyses from the laboratories of the United States Geological Survey, 1880 to 1903, tabulated by F. W. Clarke, Chief Chemist. 1903. 119 pp.

B 228. Analyses of rocks from the laboratory of the United States Geological Survey, 1880 to 1903, tabulated by F.W. Clarke, Chief Chemist. 1904. 375pp. 

PP 28. The superior analyses of igneous rocks from Roth's tabellen, 18C9 to 1884, arranged according to

the quantitative system of classification, by H. S. Washington. 1904. 68pp. 

B 239. Rock cleavage, by C. K. Leith. 1904. 216 pp., 27 pis.

B 241. Experiments on schistosity and slaty cleavage, by G. F. Becker. 1904. 34 pp.,7 pis. 

B 253. Comparison of a wet and crucible-fire method for the assay of gold telluride ores, with notes on

the errors occurring in tne operations of fire assay and parting, by W. F. Hillebrand and E. T.

Alien. 1905. 33 pp. 

B 261. Preliminary report of the operations of the coal-testing plant of the United States Geological

Survey at the' Louisiana Purchase Exposition, St. Louis, Mo,, 1904; E.W. Parker, J. A.

Holmes, M. R. Campbell, committee in charge. 1905. 172 pp. 

B 262. Contributions to mineralogy from the United States Geological Survey, by F. W. Clarke, W. F.

Hillebrand, F. G. Ransome, S. L. Penfield, Waldemar Lindgren, George Steiger, and W. T.

Schaller. 1905. 147 pp. ' ' 

PP 48. Report on the operations of the coal-testing plant of the United States Geological Survey at the

Louisiana Purchase Exposition, St. Louis, Mo., 1904; E. W. Parker, J. A. Holmes, M.R.

Campbell, committee in charge. 1906. 3 parts. 1,492 pp., 13 pis. 

B 290. Preliminary report on the operations of the fuel-testing plant of the United States Geological

Survey at St. Louis, Mo.,1905, by J. A. Holmes. 190C. 240pp.

B 305. The analysis of silicate and carbonate rocks, by W.F.Hillebrand. 1906. 200pp. 

B 312. The interaction between minerals and water solutions, with special reference to geologic phenomena, by E.G. Sullivan. 1907. 69pp.
SEEIES LIST. IH

B 316. Contributions to economic geology, 1906, Part II: Coal, lignite, and peat; M. R. Campbell, geologist in cnarge. 1907. 543 pp.,23 pis.

B 323. Experimental work conducted in the chemical laboratory of the United States fuel-testing 

plant at St. Louis, Mo., January 1,1905, to July 31, 1906, by N- W. Lord. 1907. 49 pp.

B 325. A study of four hundred steaming tests made at the fuel-testing plant, St. Louis, Mo., in 

'1904,1905, and 1906, by L. P. Breckenridge. 1907. 196 pp.

B 330. The data of geochemistry, by F. W. Clarke. 1908. 716 pp. '

Correspondence should be addressed to

THE DIRECTOR,

UNITED STATES GEOLOGICAL SURVEY, 

JANUARY, 1908. WASHINGTON, D. C.

o

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