INDEX 
Magnetite, 47. 
Mail-clad fishes, 412, 417. 
Malaspina glacier, Alaska, 211, 216, 217. 
Mammalian era, 402. 
Mammals, Cenozoic, 433; Mesozoic, 431. 
Mammoth, 393. 
Mammoth Cave, 141. 
Man, origin of, 438. 
Manganese, 24, 28. 
Mangrove swamps, 250. 
Marble, 90, 99, 105, 367, 404. 
Marl, 90, 189. 
Marshes, salt, 248. 
Mastodon, 436. 
Mato Tepee, 351. 
Mauna Loa, 333, 340. 
Meandering of river, 164. 
Mechanical agents in weathering, 112, 
128. 
Mechanical ore deposits, 379. 
Mechanical work of rivers, 158, 173. 
Medial moraine, 196, 204, 205, 218. 
Medina sandstone, 454. 
Megatherium, 435. 
Mercury, 24, 33. 
Mesozoic, 402; life of, 426. 
Metals, 24; source of, 378. 
Metamorphic rocks, 54, 98, 104, 105, 322, 
366; age of, 403; position of, 371. 
Metamorphism, 322, 349; complexity of, 
103; contact, 378; destruction of fos- 
sils by, 390; kinds of, 378; nature of, 
98, 366; of Ordovician strata, 451; 
regional, 378; results of, 99; of strata, 
406. 
Mica, 44, 45, 66, 367, 373. 
Mica schist, 101, 105, 368. 
Micaceous sandstone, 80. 
Mineral, definition of, 33. 
Mineral springs, 150. 
Mineral waters, 146, 150. 
Mineral veins, 84, 322, 362, 380. 
Minerals, 33; conditions of formation, 
35; decay of, 118, 119; important, 37; 
in solution, 275. 
Mississippi, delta in, 183, 184, 186; sedi- 
ment in, 174. 
Mississippi valley, development of, 469. 
Moisture, aid of, in weathering, 114, 128. 
Monoclinal mountains, 310, 
495 
Monocline, 285, 286. 
Monte Somma, 340. 
Moraines, 196, 203, 218, 219, 481-483. 
Mountains, 18; absence of soil from, 121; 
ancient eastern, 451; association of 
earthquakes with, 358, 361 ; associaticu 
of volcanoes with, 322, 352; cause of, 
322; definition of, 304; growth of, 
318, 320, 471; metamorphism in, 371- 
373, 375; in New England, 451; per- 
manence of, 317; phenomena accom- 
panying growth of, 521; position of, 
314; rapidity of weathering in, 122, 
123; synclinal, 309; types of, 310; 
wind action in, 130, 138. 
Mountain folding, 301. 
Mountain peaks, 305, 306, 314. 
Mountain ranges, 3504. 
Mountain ridges, 304, 311-314. 
Mountain systems, 307, 308. 
Mud cracks, 269. 
Mud flows, 332. 
Muir glacier, 197, 198, 203, 206. 
Multonomah Falls, 169. 
Murray, theory of atolls, 256. 
N 
Natural gas, 31, 60, 61, 418. 
Nashaquitsa cliffs, retreat of, 234. 
Nebular hypothesis, 445. 
Neck, voleanic, 346, 350. 
Neocene, 398, 402; geography of, 470. 
Neolithic stage, 400. 
Névé, 197. 
Newark, 402. 
New England, changes in level of, 298; 
mountains of, 452; in Silurian, 456. 
New Jersey, sinking of coast of, 295. 
New York, strata of, 453. 
Niagara Falls, 166, 167, 455. 
Niagara gorge, age of, 477. 
Niagara strata, 402, 455. 
Nickel ores, 379. 
Nile, delta in, 183, 184. 
Nitrogen, 14, 24, 26. 
Non-metallic elements, 24. 
Norite, 66. 
Normal faults, 292, 293. 
Nunataks, 214, 
