492 
Diatomaceous earth, 91, 97. 
Diatoms, 38. 
Dinornis, 442. 
Dinosaurus, 429. 
Diorite, 66. 
Dip, 283. 
Disintegration of rocks, 72. 
Dismal Swamp, 190, 462. 
Dolomite, 43, 86. 
Dormant volcanoes, 343. 
Downthrown side of fault, 290. 
Dryness, effect, in weathering, 112, 128. 
Dykes, 347, 349; earthquakes caused by, 
360. 
Dynamic geology, 8, 107. 
E 
Earth, changes in, 458; condition of, 13, 
17; early history of, 444; form of, 18; 
irregularities of, 18. 
Earthquake wave, 354. 
Earthquake water wave, 349, 357. 
Earthquakes, 319, 321, 349, 353; cause 
of, 358; effects of, 356; in Japan, 295. 
Earth’s crust, 17, 20. 
Earthworms, aid in weathering, 116, 128. 
Effusive igneous rocks, 66. 
Elements, 23; combination of, 25; im- 
portant, 24; number of, 24. 
Elevated shore lines, 297. 
Elevation of land, 295; in Tertiary, 472. 
Elevation of sea bottom, 272. 
Eocene, 398, 402; geography of, 470. 
Eozoon, 405. 
Epicentrum, 354. 
Epoch, 401, 402. 
Era, 401, 402. 
Erosion, 127, 129; by glaciers, 207, 219, 
241; in lakes, 237; in ocean, 220, 239, 
241; by ocean ice, 233; by rain, 151, 
173, 241; by rivers, 151, 173, 241; of 
sea-coast, 234, 239; by tides, 231, 239; 
by waves, 221, 228, 239; by wind, 129, 
138, 241. 
Eruptions of voleanoes, 332. 
Eruptive rocks, 52, 56, 66. 
Estuaries, origin of, 186, 229, 297, 472. 
Etna, 341. 
Evolution, 395; of man, 443. 
ELEMENTARY GEOLOGY 
Extinct voleanoes, 343. 
Extrusive rocks, 56. 
F 
Fault-block mountains, 310. 
Fault plane, 288, 289, 290-292. 
Faults, 262, 287, 310, 319, 321; earth- 
quakes caused by, 359, 360; association 
with voleanoes, 329; hot springs in, 
146, 362; kinds of, 290; nature of, 287 ; 
overthrust, 324; veins in, 380, 384. 
Feldspar, 40, 66, 373; decay of, 119. 
Ferruginous sandstone, 80. 
Fingal’s Cave, joint planes of, 278. 
Fire clay, 81. 
Fishes, ancestors of, 424; Carboniferous, 
419; Devonian, 416, 417; Mesozoic, 
428; Ordovician, 408; Silurian, 411. 
Fissures, 321; association of, with vol- 
canoes, 329, 351; eruptions from, 338; 
hot springs in, 362; veins in, 380. 
Fjords, origin of, 297, 472. 
Flint, 95, 277. 
Floodplains, 178, 187. 
Florida, origin of, 237. 
Flow structure, 70. 
Focus of earthquake, 354. 
Folds of rocks, 283, 304; anticlinal, 285, 
287, 288; inverted, 286, 288; over- 
turned, 286, 288, 324; symmetrical, 
286, 287, 311, 313; syneclinal, 285, 287, 
288; unsymmetrical, 286, 288, 311, 313. 
Forces modifying earth’s surface, 19. 
Forests, protection of, 123, 124; sub- 
merged, 298, 300. 
Fossils, 91, 92, 388; beneath lava, 345;. 
earliest, 405; meaning of, 400; of 
plants, 94; proof of elevation by, 296; 
uses of, 387, 393; value of, 320. 
Fragmental rocks, 71, 73, 97. 
Freestone, 80. 
Fringing reef, 254. 
Frontal moraine, 205. 
Frost action in weathering, 112, 128. 
Fundamental complex, 402. 
G 
Gabbro, 59, 66. 
Gangue, 382. 
