CONCENTRATION TO MAKE THEM COMMERCIALLY AVAILABLE 54

ANAMORPHISM OF MINERAL DEPOSITS 57

CONCLUSION 58

CHAPTER IV. MINERAL RESOURCES--SOME GENERAL
QUANTITATIVE CONSIDERATIONS 60

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

CHAPTER V. WATER AS A MINERAL RESOURCE 67

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

CHAPTER VI. THE COMMON ROCKS AND SOILS AS MINERAL
RESOURCES 80

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