ies, phosphates, 105, 106

Dynamic metamorphism, 25-26

East Africa, mica, 286

East Indies. See Dutch East Indies.

Eckel, E. C., 404

Economic Liaison Committee, 406

Egypt, petroleum, 128
phosphates, 104

Eiserner Hut, 313

Electrical conductivity, use in exploration of mineral deposits, 319

Ely, Nevada, copper ores, 41, 203

Emeralds, 289, 291, 293

Emery, 267-268, 270, 397, 398

Emmons, W. H., 43

Empire, Colorado, molybdenum ores, 186

Energy resources, 115-153
accelerating production of, 64, 130-131, 361, 366-367

Engineering, application of economic geology to, 2, 413-419

England. _See_ Great Britain

Enrichment, secondary, 7-8, 25, 46-50.
_See also_ under Copper ores, silver ores, etc.

Epigenetic ore deposits, use of term, 32, 36

"Equated Income" method of taxation, 335-336

Erosion, relation to oxide zones, 47-48

Erosion cycle, description of, 6-7

Ethics, questions of, 430-431

Europe, coal and iron situation under terms of Peace Treaty, 400-403

Expert witnesses, use of geologists as, 349-355, 357-358

Exploitation of mineral deposits, functions of geologist, 326-327

Exploration of mineral deposits, 301-327
effect of ownership laws on, 347-349
effect of taxation on, 339-341
quantitative aspects of, 321-322, 324-326
relation to international conditions, 395-396

Extralateral rights, litigation affecting, 349-355

Extrusive rocks, formation of, 19

Federated Malay States. _See_ Malay States.

Feldspar, 16, 86, 268-269, 397

Ferro-alloy minerals, 156-158, 173-196, 307, 362-363, 365-366, 393-394,
397-398

Ferroboron, 275

Ferrocerium, 288

Ferrochrome, 178

Ferromanganese, 173-174

Ferromolybdenum, 186

Ferrosilicon, 195

Ferrotitanium, 190

Ferrotungsten, 182-183

Ferrovanadium, 187

Ferrozirconium, 189

Ferruginous chert, 167

Fertilizer minerals, 99-114

Field work for students of economic geology, 425-426

Flint linings for tube mills, 269

Florida, fuller's earth, 279
phosphates, 105, 107
titanium, 190, 191
zirconium, 189

Flowage, rock, 25, 26

Fluorspar, 193-194, 397

Foothill district, California, copper ores, 204

Formosa, petroleum, 128

Foundations, application of geology to, 413

France, antimony, 247, 249
arsenic, 250-251
asphalt and bitumen, 152
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