CONTENTS

CHAPTER PAGE
[I.]INTRODUCTION1
Survey of Field[1]
Economic applications of the several branches of geology and of other sciences[3]
Stratigraphy and paleontology[4]
Structural geology[5]
Physiography[6]
Rock alterations or metamorphism[10]
Application of other sciences[10]
Treatment of the subject in this volume[11]
[II.]THE COMMON ELEMENTS, MINERALS, AND ROCKS OF THE EARTH AND THEIR ORIGINS13
Relative abundance of the principal elements of the lithosphere[13]
Relative abundance of the principal minerals of the lithosphere[14]
Relative abundance of the principal rocks of the lithosphere[16]
Water (hydrosphere)[18]
Soils and clays[18]
Comparison of lists of most abundant rocks and minerals with commercial rocks and minerals[18]
The origin of common rocks and minerals[19]
Igneous processes[19]
Igneous after-effects[19]
Weathering of igneous rocks and veins[20]
Sedimentary processes[22]
Weathering of sedimentary rocks[23]
Consolidation, cementation, and other sub-surface alterations of rocks[24]
Cementation[24]
Dynamic and contact metamorphism[25]
The metamorphic cycle as an aid in studying mineral deposits[27]
[III.]SOME SALIENT FEATURES OF THE GEOLOGY AND CLASSIFICATION OF MINERAL DEPOSITS29
Various methods of classification[29]
Names[31]
Mineral deposits as magmatic segregations in igneous rocks[34]
Mineral deposits within and adjacent to igneous rocks, which were formed immediately after the cooling and crystallization of the magmas through the agency of hot magmatic solutions[36]
Evidence of igneous source[37]
Possible influence of meteoric waters in deposition of ores of this class[41]
Zonal arrangement of minerals related to igneous rocks[42]
The relation of contact metamorphism to ore bodies of the foregoing class[45]
Secondary concentration in place of the foregoing classes of mineral deposits through the agency of surface solutions[46]
Residual mineral deposits formed by the weathering of igneous rocks in place[50]
Mineral deposits formed directly as placers and sediments[51]
Mechanically deposited minerals[51]
Chemically and organically deposited minerals[52]
Sedimentary mineral deposits which have required further concentration to make them commercially available[54]
Anamorphism of mineral deposits[57]
Conclusion[58]
[IV.]MINERAL RESOURCES—SOME GENERAL QUANTITATIVE CONSIDERATIONS60
World annual production of minerals in short tons[60]
World annual production of minerals in terms of value[62]
Significance of geographic distribution of mineral production[63]
The increasing rate of production[63]
Capital value of world mineral reserves[64]
Political and commercial control of mineral resources[65]
Reserves of mineral resources[65]
[V.]WATER AS A MINERAL RESOURCE67
General geologic relations[67]
Distribution of underground water[68]
Movement of underground water[71]
Wells and springs[72]
Composition of underground waters[73]
Relation of geology to underground water supply[75]
Surface water supplies[76]
Underground and surface waters in relation to excavation and construction[78]
[VI.]THE COMMON ROCKS AND SOILS AS MINERAL RESOURCES80
Economic features of the common rocks[80]
Granite[82]
Basalt and related types[82]
Limestone, marl, chalk[82]
Marble[83]
Sand, sandstone, quartzite (and quartz)[84]
"Sand and gravel"[84]
Clay, shale, slate[85]
The feldspars[86]
Hydraulic cement (including Portland, natural, and Puzzolan cements)[86]
Geologic features of the common rocks[88]
Building stone[88]
Crushed stone[90]
Stone for metallurgical purpposes[91]
Clay[91]
Limitations of geologic field in commercial investigation of common rocks[92]
Soils as a mineral resource[94]
Origin of soils[94]
Composition of soils and plant growth[96]
Use of geology in soil study[97]
[VII.]THE FERTILIZER GROUP OF MINERALS99
General comments[99]
Nitrates[101]
Economic features[101]
Geologic features[102]
Phosphates[104]
Economic features[104]
Geologic features[105]
Pyrite[107]
Economic features[107]
Geologic features[108]
Sulphur[109]
Economic features[109]
Geologic features[110]
Potash[111]
Economic features[111]
Geologic features[112]
[VIII.]THE ENERGY RESOURCES—COAL, OIL, GAS (AND ASPHALT)115
Coal[115]
Economic features[115]
World production and trade[115]
Production in the United States[117]
Coke[118]
Classification of coals[119]
Geologic features[123]
Petroleum[127]
Economic ffeatures[127]
Production and reserves[128]
Methods of estimating reserves[134]
Classes of oils[136]
Conservation of oil[137]
Geologic features[140]
Organic theory of origin[140]
Effect of differential pressures and folding on oil genesis and migration[142]
Inorganic theory of origin[143]
Oil exploration[144]
Oil shales[150]
Natural gas[151]
Economic features[151]
Geologic features[151]
Asphalt and bitumen[151]
Economic features[151]
Geologic features[153]
[IX.]MINERALS USED IN THE PRODUCTION OF IRON AND STEEL (THE FERRO-ALLOY GROUP)154
General features[154]
Iron ores[158]
Economic features[158]
Technical and commercial factors determining use of iron ore materials[158]
Geographic distribution of iron ore production[160]
World reserves and future production of iron ore[162]
Geologic features[166]
Sedimentary iron ores[166]
Iron ores associated with igneous rocks[171]
Iron ores due to weathering of igneous rocks[171]
Iron ores due to weathering of sulphide ores[173]
Manganese ores[173]
Economic features[173]
Geologic features[176]
Chrome (or chromite) ores[178]
Economic features[178]
Geologic features[179]
Nickel ores[180]
Economic features[180]
Geologic features[180]
Tungsten (wolfram) ores[182]
Economic features[182]
Geologic features[184]
Molybdenum ores[185]
Economic features[185]
Geologic features[186]
Vanadium ores[187]
Economic features[187]
Geologic features[188]
Zirconium ores[189]
Economic features[189]
Geologic features[189]
Titanium ores[190]
Economic features[190]
Geologic features[190]
Magnesite[191]
Economic features[191]
Geologic features[192]
Fluorspar[193]
Economic features[193]
Geologic features[194]
Silica[195]
Economic features[195]
Geologic features[196]
[X.]COPPER, LEAD AND ZINC MINERALS197
Copper ores[197]
Economic features[197]
Geologic features[199]
Copper deposits associated with igneous flows[200]
Copper veins in igneous rocks[201]
"Porphyry coppers"[203]
Copper in limestone near igneous contacts[204]
Copper deposits in schists[204]
Sedimentary copper deposits[205]
General comments[206]
Lead ores[209]
Economic features[209]
Geologic features[211]
Zinc ores[213]
Economic features[213]
Geologic features[216]
[XI.]GOLD, SILVER, AND PLATINUM MINERALS221
Gold ores[221]
Economic features[221]
Geologic features[226]
Silver ores[231]
Economic features[231]
Geologic features[234]
Platinum ores[237]
Economic features[237]
Geologic features[239]
[XII.]MISCELLANEOUS METALLIC MINERALS[241]
Aluminum ores[241]
Economic features[241]
Geologic features[243]
Antimony ores[246]
Economic features[246]
Geologic features[248]
Arsenic ores[249]
Economic features[249]
Geologic features[251]
Bismuth ores[252]
Economic features[252]
Geologic features[252]
Cadmium ores[253]
Economic features[253]
Geologic features[254]
Cobalt ores[254]
Economic features[254]
Geologic features[255]
Mercury (quicksilver) ores[255]
Economic features[255]
Geologic features[258]
Tin ores[260]
Economic features[260]
Geologic features[261]
Uranium and radium ores[263]
Economic features[263]
Geologic features[264]
[XIII.]MISCELLANEOUS NON-METALLIC MINERALS267
Natural abrasives[267]
Economic features[267]
Geologic features[269]
Asbestos[270]
Economic features[270]
Geologic features[271]
Barite (barytes)[272]
Economic features[272]
Geologic features[273]
Borax[274]
Economic features[274]
Geologic features[275]
Bromine[277]
Economic features[277]
Geologic features[278]
Fuller's earth[278]
Economic features[278]
Geologic features[279]
Graphite (plumbago)[279]
Economic features[279]
Geologic features[282]
Gypsum[283]
Economic features[283]
Geologic features[284]
Mica[285]
Economic features[285]
Geologic features[287]
Monazite (thorium and cerium ores)[288]
Economic features[288]
Geologic features[289]
Precious stones[289]
Economic features[289]
Geologic features[291]
Salt[294]
Economic features[294]
Geologic features[295]
Talc and soapstone[299]
Economic features[299]
Geologic features[299]
[XIV.]EXPLORATION AND DEVELOPMENT301
The general relations of the geologist to exploration and development[301]
Partly explored versus virgin territories[303]
The use of all available information[304]
Coöperation in exploration[305]
Economic factors in exploration[306]
Geologic factors in exploration[307]
Mineral provinces and epochs[308]
Classification of mineral lands[309]
Outcrops of mineral deposits[311]
Some illustrative cases[312]
Topography and climate as aids in searching for mineral outcrops[314]
Size and depth of ore bodies as determined from outcrops[315]
The use of placers in tracing mineral outcrops[316]
The use of magneetic surveys in tracing mineral ledges[317]
The use of electrical conductivity and other qualities of rocks in exploration[319]
The use of structure and metamorphism in exploration[310]
Drilling in exploration[320]
Quantitative aspects of geologic exploration[321]
Origin of mineral deposits as a factor in exploration[322]
Lake superior iron ore exploration as an illustration[323]
Development and exploitation of mineral deposits[326]
[XV.]VALUATION AND TAXATION OF MINERAL RESOURCES328
Popular conception of mineral valuation[328]
Valuation and taxation of mines[329]
Intrinsic and extrinsic factors in valuation[329]
Values of mineral deposits not often established by market transfers[331]
The ad valorem method of valuation[331]
Other methods of mineral valuation and taxation[335]
General comments on taxation of mineral resources[338]
[XVI.]LAWS RELATING TO MINERAL RESOURCES342
I.Laws relating to ownership and control of mineral resources[342]
On alienated lands[343]
On the public domain[344]
Nationalization of mineral resources[345]
Effect of ownership laws on exploration[347]
Use of geology in relation to ownership laws[349]
II.Laws relating to extraction of mineral resources[355]
III.Laws relating to distribution and transportation of mineral resources[355]
IV.Other relations of geology to law[356]
[XVII.]CONSERVATION OF MINERAL RESOURCES359
The problem[359]
Differences between private and public efforts in conservation[363]
The interest rate as a guide in conservation[364]
Anti-conservational effects of war[365]
Conservation of coal[366]
Measures introduced or proposed to conserve coal[367]
(A) Mining and preparation of coal[368]
Progress in above methods[370]
(B) Improvement of labor and living conditions at the mines[372]
(C) Introduction or modification of laws to regulate or to remove certain restrictions on the coal industry[373]
(D) Distribution and transportation of coal[376]
(E) Utilization of coal[377]
(F) Substitutes for coal as a source of power[378]
Division of responsibility between government and private interests in the conservation of coal[379]
Conservation of minerals other than coal[382]
[XVIII.]INTERNATIONAL ASPECTS OF MINERAL RESOURCES383
World movement of minerals[383]
Movemenet of minerals under pre-war conditions of international trade[385]
Changes during the war[385]
Post-war condition of the mineral trade[387]
Tendencies toward international coöperation and possibility of international control of minerals[389]
Methods of international coöperation[391]
Conservation in its international relations[393]
Exploration in its international relations[395]
Valuation in its international relations[396]
Relative position of the united states in regard to supplies of minerals[396]
The coal and iron situation of western europe under the terms of the peace[400]
Conclusion[403]
Literature[403]
[XIX.]GEOLOGY AND WAR405
Geology behind the front[405]
Geology at the front[408]
Effect of the war on the science of economic geology[412]
[XX.]GEOLOGY AND ENGINEERING CONSTRUCTION413
Foundations[413]
Surface waters[414]
Tunnels[414]
Slides[415]
Subsidence[417]
Railway building[417]
Road building[418]
Geology in engineering courses[419]
[XXI.]THE TRAINING, OPPORTUNITIES AND ETHICS OF THE ECONOMIC GEOLOGIST420
Pure versus applied science[420]
Course of study suggested[422]
Field work[425]
Specialization in studies[426]
A degree of Economic Geology[427]
The opportunities of the economic geologist[428]
Ethics of the economic geologist[430]

ILLUSTRATIONS

FIGUREPAGE
1.[Graphic representation of volume change in weathering of a Georgia granite]21
2.[Commercial (financial) control of the mineral resources of the world]64
3.[Political (territorial) control of the mineral resources of the world]64
4.[The fertilizer situation in the United States]100
5.[Diagram showing the chemical composition and heat efficiency of the several ranks of coal]122
6.[Origin and development of coal]123
7.[Chart showing the present tendency of the United States in respect to its unmined reserve of petroleum]134
8.[The annual output of the principal oil fields of the United States for the last twenty years]135
9.[Curve showing the usual decline in oil field production after the period of maximum output is reached]136
10.[Chart showing the relative values of the principal petroleum products manufactured in the United States from 1899 to 1914]138
11.[Alteration of Lake Superior iron formation to iron ore by the leaching of silica]168
12.[Representing in terms of weight the mineralogical changes in the katamorphism of serpentine rocks to iron ore, eastern Cuba]172
13.[Diagram showing gradation from syenite to bauxite in terms of volume]245