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
CHAPTER XI. GOLD, SILVER, AND PLATINUM MINERALS 221
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
CHAPTER 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
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