INDEX 



471 



Lahontan, 459. 

 Lake, 233, 261. 

 Lake Bonneville, 459. 

 Lakes, deposits in, 268. 



extinct, 267. 



fate of, 266. 



flood-plain, 179. 



function of, 264. 



marginal, 454. 



ox-bow, 180. 



permanent, 263. 



processes in, 264. 



Quaternary, 458. 



salt, 268. 



Lake Superior region, 322. 

 Laminae, 54. 



Lamination, oblique, 55. 

 Lamp shells, 298. 

 Land animals, Pennsylvanian, 



385. 

 Land, in Jurassic period, 405. 



of Permian period, 390. 

 Land life, Devonian, 368. 

 Landslide, 115, 116, 117. 

 Land-tied islands, 248. 

 Lapilli, 33. 



Laramie formation, 423. 

 Lava, 25. 

 Lava flow, 49. 

 Lava plateaus, 47. 

 Lava sheet, 58. 

 Lead, 120. 



Lead deposits, Ordovician, 342. 

 Lee slopes, 219. 

 Lepidodendron, 383. 

 Levee, natural, 177. 

 Limestone, 39. 



beds of, 64. 



Mississippian, 370. 

 Limonite, 22. 

 Lithosphere, 14, 16. 

 Littoral current, 246. 

 Load of stream, 132. 

 Loess, 98. 

 Loop, 248. 



Magnetite, 22. 

 Mammals, 301, 402 



Mammals, Cretaceous, 431. 



evolution of, 444. 



hoofed, 443. 



Jurassic, 411. 



migration of, 445. 

 Man, appearance of, 462. 

 Mantle rock, 17. 

 Marble, 44. 

 Marginal lakes, 453. 

 Marine strata, 397. 

 Marl, 269. 



Massive structure, 52. 

 Mastodon, 461. 

 Mauch Chunk shale, 370. 

 Meanders, 152, 178, 179. 

 Medina sandstone, 350. 

 Medusae, 296. 

 Mesas, 52, 167. 

 Meta-igneous series, 45. 

 Metamorphic cycle, 83. 

 Metamorphic rock, 19, 41. 

 Metamorphism, 11. 

 Meta-sedimentary series, 44. 

 Mica, 22. 



Migration of dunes, 94. 

 Migrations in glacial epoch, 460. 



of Tertiary mammals, 445. 

 Millstone grit, 387. 

 Mineralizers, 26. 

 Mineralogy, 9. 

 Minerals, 19, 20. 

 Mineral vein, 79. 

 Miocene epoch, 433. 

 Mississippian crinoids, 372. 

 Mississippian limestone, 378. 

 Mississippian period, 369. 

 Mississippian seas, 371. 

 Mississippian sedimentation, 370. 

 Mollusks, 298, 406. 



Devonian, 364. 

 Monadnocks, 150. 

 Monoclines, 66. 

 Monroe strata, 357. 

 Moraines, 209. 

 Mosasaur, 425. 

 Moss, 293. 



Mountain growth of Tertiary 

 period, 438. 



