INDEX 



395 



Leucite-nepheline rocks, the, 96 



chemical composition of, 96 

 classification of, 97 

 colors of, 96 



mineral composition of, 96 

 nomenclature of, 97 

 structure of, 96 

 Leucitite, 97 

 Leucitophyr, 76 

 Leueophyr, 84 

 Lherzolite, 92 

 Lichens, action of, 180 

 Liebnerite, 75 

 Lignite, defined, 130 

 Limburgite, 93 



composition of, 90 

 Lime and magnesia, relative solu- 

 bility, 225 

 carbonate, decomposing action 



of, 355 

 in soils, 355 

 Limestone and dolomite, age of, 142 

 analyses of, 217, 219 

 chemical composition of, 127 

 color, variations of, 126 

 oolitic, 105 

 of Bermuda, 233 

 relative solubility of, 170 

 saccharoidal, 141 

 weathering of, 217 

 crystalline, chemical and mineral 

 composition of, 141 

 colors of, 141 

 nomenclature of, 141 

 structure of, 141 

 Limonite, 101 



as a rock constituent, 26 

 Liparites, the, 66 



Liparite, chemical composition of, 67 

 classification of, 68 

 color of, 67 



mineral composition of, 66 

 nomenclature of, 68 

 structure of, 67 

 Litchfieldite, 75 

 Loess, 121, 315 



characteristics of, 315 

 chemical analyses of, 318 

 distribution of, 316 

 mechanical analyses of, 319 

 microscopic examination of, 317 

 of Europe, 316 

 of the ITnited States, 317 

 section of, 319 

 Luxullianite, 64 

 Lydian stone, 104 



Magnesian limestone, 126 

 Magnesia, relative solubility of, 225 

 Magnesite, 106 

 Magnesium as a constituent of the 



earth's erust, 6 

 Magnetite as a rock constituent, 25 

 Man, ravages of, 387 



as a geological agent, 385 

 Manganese as a constituent of the 

 earth's crust, 7 

 oxide, 101 

 Marble, definition of, 126 

 Marls, composition and origin of, 



Melaphyrs, the, 85 



classification, 85 



colors of, 85 



mineral composition of, S5 



nomenclature of, 85 



structure of, 85 

 Melilite basalt, 87 

 Menaccanite as a rock constituent, 



Metamorphic rocks, 135, 140 



Metamorphism defined, 135 



Metasomatosis, 137 



Miascite, 75 



Mica as a rock constituent, 21 



Microcline as a rock constituent, 15 



Mierogranite, 66 



Microscopic structure of rocks, 35 



Microscope, utility of in study of 



rocks, 36 

 Mineral matter dissolved in river 

 water, 171 

 nature of soils, 362 

 Minerals, coefficient of expansion of, 

 255 

 constituting rocks, 9 

 relative durability of, 235 



resistance to weathering, 

 221 

 soluble in carbonic acid, 169 

 Minette defined, 69 

 Mississippi flood plain, 312 



river, sediment carried by, 276 

 Monazite sands, origin of, 254 

 Monzonite defined, 70 

 Moraines, character of, 340 



classified, 278 

 Morainal material, distributed by 



water, 344 

 Mountains, height limited by weath- 

 ering, 265 

 Mucky soils, 314 

 Muscovite as a rock constituent, 21 



ISTapoleonite, 77 



