Gneissic structure, 26

Gogebic district, Michigan, iron ores, 312, 318, 325-326

Gold, monetary reserves, 223

Gold Coast, West Africa, manganese, 176

Gold ores, 36-50, 51, 221-230, 308-309, 313-314, 397

Goldfield, Nevada, alunite, 41-42, 114
bismuth, 253
gold-silver ores, 36, 39, 230, 308

Gossan, 47, 109, 173, 313

Government ownership and control. _See_ Nationalization.

Governments, participation in mineral ownership and international
trade, 388-390

Granite, 17, 19, 82, 90

Graphite, 279-283, 398

Graphite Association, Southern, 405

Gravel, sand and, 84-85

Gray, F. W., 368

Great Basin, Nevada, covering of mineral deposits by lavas, 311-312
gold-silver ores, occurrence in a metallogenic province, 308
tungsten ores, 185

Great Britain, arsenic, 250
barite, 272
cadmium, 253
cement, 78
chalk, 83
clay, 85
coal, 115-117, 126, 127
fluorspar, 193-194
fuller's earth, 278-279
grindstones and pulpstones, 269
gypsum, 283
iron, 154, 160-161, 163
manganese, 176
salt, 294
tripoli and rottenstone, 269
uranium and radium, 264

Great Britain, control of various minerals outside of British Isles,
64, 101, 104-105, 132, 152, 165, 178, 181, 183, 198, 210, 214,
222, 225, 232, 242, 247, 252, 256-257, 260, 275, 280
income taxes on mineral properties, 337, 339
laws relating to ownership of mineral resources, 343
participation of government in mineral trade, 388
relative position, in regard to supplies of minerals, 399
tendencies toward nationalization, 346

Great Plains, lignite, 118
pumice, 268

Greece, chromite, 178-179
emery, 268, 270
magnesite, 191-193
zinc, 214

Greenland, graphite, 280

Gregory, Herbert, 407, 413

Grimes, J. A., and Billingsley, Paul, 44

Grinding pebbles, 267, 268, 270, 398

Grindstones, 269

Ground-waters, composition of and relation to commercial use, 73-75
distribution and movement of, 68-72
influence in deposition of ore deposits, 41-42
relation to military operations, 78-79, 408, 410-411
relation to rock slides, 78, 416-417
source of, 68

Ground-water level, description of, 70
relation to oxide zone, 48
relation to zone of weathering, 22

Ground-water supply, relation of geology to, 75-76

Guano, 104, 106

Guatemala, chromite,