Principles of Geochemical Prospecting (eBook)

Front Cover 1
Principles of Geochemical Prospecting: Techniques of Prospecting for Non-Ferrous Ores and Rare Metals 4
Copyright Page 5
Table of Contents 6
FOREWORD 10
INTRODUCTION 12
CHAPTER I. METHODS OF ANALYTICAL INVESTIGATIONS 
20 
CHAPTER II. GEOCHEMICAL TRACERS (INDICATORS) 31
Elements as geochemical indicators 31
Trace-elements in mineral crystal structures as indicators 35
Minerals as geochemical indicators 38
Choice of indicators 40
Geochemical correlations 41
CHAPTER III. ACCUMULATION OF METALS IN IGNEOUS AND METAMORPHIC 
45 
Geochemical principles of accumulation and dispersion of elements 45
Mobility of elements 46
Permeability of rocks and accumulations of metals 48
The concept of dispersion halos 51
Connection between dispersion halos and metalliferous deposit structures 52
Character of distribution of ore minerals in bedrock 53
Metalliferous mineralization 55
The barren mineralization 56
Trace elements in lattice of minerals 58
Dispersed mineralization 60
Enrichment and metalliferous mineralization 65
Mineralization coefficients 68
The shape of mineralized areas, their size, and distribution 72
CHAPTER IV. ACCUMULATION OF METALS IN SEDIMENTARY ROCK 
77 
Factors determining accumulation 77
Mechanisms of transfers of sediments 78
Requirements for precipitation and transport of metal-bearing sediments 81
Metal-content of sedimentary rock 88
CHAPTER V. PROSPECTING IN BEDROCKS 95
Role of supergene processes in variations of metal-content in bedrocks 95
Supergene migration of metals into host rocks 99
Correlation proportions in supergene zones and in bedrocks 103
Dispersion of easily mobile elements in bedrock 107
Geochemical prospecting for sedimentary deposits 109
CHAPTER VI. PROSPECTING FOR DEPOSITS WITHOUT SURFACE OUTCROPS 
112 
Locating ore bodies under loose materials of extraneous origin 112
Prospecting for ore bodies within sedimentary rocks 113
Prospecting for blind ore bodies in bedrock 113
Structural factors 113
Products of hydrothermal and supergene alterations 113
Zoning in ore bodies and stages of hydrothermal activity 114
Behavior of metals in the hanging wall and footwall of ore bodies and dimensions of 
115 
Importance of erosion surface in prospecting for blind ore bodies 120
Some indications of blind ores 120
Testing 126
Interpretation of geochemical survey 127
Some conclusions 128
CHAPTER VII. ACCUMULATION OF METALS IN UNCONSOLIDATED OVERBURDEN 
131 
Dispersion halos 131
Factors and processes affecting development of dispersion halos 132
Modern weathering and soil-forming processes 133
Behavior of individual elements in soils 134
Behavior of copper 138
Behavior of lead 139
Behavior of zinc and cadmium 139
Behavior of molybdenum 140
Behavior of tin 140
Behavior of arsenic, selenium, antimony and tellurium 140
Behavior of gold 141
Behavior of silver 141
Behavior of nickel and cobalt 141
Behavior of barium and strontium 141
Behavior of boron 142
Behavior of fluorine 142
Ancient weathering 145
Aspiration of solutions by root systems 148
Mineralization of plant residues 149
Capillary rise of ground waters and their evaporation caused by insolation 
149 
Role of capillary rise in arid regions 151
Effect of watering on accumulation of metals 152
Problems in ascent of water-soluble salts from depths 153
Bleached zones 164
Mineral composition of oxidized zones. Gossans 164
Erosion of weathered crusts and of oxidized zones 166
Mechanical transportation 168
Mechanism of development of halos and of dispersion streams 170
Coagulation, precipitation and sorption 175
Genetic types of halos 176
Forms of dispersion halos in surficial sediments 178
CHAPTER VIII. PROSPECTING AT THE SURFACE OF THE OVERLYING MANTLE 
184 
Prospecting for lead 188
Prospecting for zinc and cadmium 189
Prospecting for silver 192
Prospecting for copper 192
Prospecting for molybdenum 196
Prospecting for tungsten 197
Prospecting for tin 199
Prospecting for gold 200
Prospecting for nickel, cobalt and chromium 201
Prospecting for fluorspar 203
Prospecting for barite 204
Prospecting for lithium 204
Conclusions 204
CHAPTER IX. MIGRATION OF METALS IN WATERS 207
Migration of metals 216
Behavior of metals and of some other elements and compounds in waters 
220 
CHAPTER .. HYDRO-GEOCHEMICAL PROSPECTING FOR METALS AND CHARACTERISTICS OF DIFFERENT WATER TYPES ASSOCIATED WITH ORE 
237 
Water of copper deposits 242
Waters of polymetallic deposits 247
Waters of rare-metals deposits 248
CHAPTER XI. THE BIO-GEOCHEMICAL METHOD OF PROSPECTING 
251 
Prospecting for iron-rich sulfides 255
Prospecting for nickel, cobalt and chromium 255
Prospecting for copper 258
Prospecting for zinc and lead 259
Prospecting for molybdenum 259
Prospecting for uranium 260
Prospecting for other elements 261
General remarks and conclusions 262
CHAPTER XII. THE GEOBOTANICAL METHOD OF PROSPECTING 
264 
Theratologic and other indicators 266
CHAPTER XIII. GENERAL CONCLUSIONS IN REFERENCE TO GEOCHEMICAL 
273 
Geochemical survey of bedrock 274
Geochemical survey of surficial materials 277
Kinds of metallometric surveys 280
Selection of Method and Interpretation of Geochemical Surveys 281
APPENDIX: RAPID METHODS OF DETERMINING LEAD, COPPER, TUNGSTEN, MOLYBDENUM AND SILVER IN THE FIELD 
288 
GLOSSARY 297
Translator's notes on soil terms used in this book 297
BIBLIOGRAPHY 308
INDEX 328