INDEX 



Pui; 



Absorption, capacity of rocks for, an index to 



power of transmission. 155 



Acid rocks, resistance of, to weathering 532-533 



Acid salts, instance of 84 



Acids, definitions of ._ 84 



solution of, by rock weathering 536,537 



strength of, dependence of, on degree of disso- 

 ciation.. _ 94 



strong and weak, discussion of 93 



work of, in ground-water solutions 93 



Acmite, chemical and physical constants of 195,271 



occurrence of.. 273 



source and mode of origin of . . 273, 2S0, 286, 289, 369, 378 



Actinolite, alterations and alteration products of. . 285- 



290,372,375,398,399 



chemical and physical constantsof 195,283 



formation of, from ankerite, chemical reaction 



involved in 837 



occurrence of _ 283-290 



sources and mode of formation of 243,268 



270, 271, 274, 277, 279, 283-284, 286-287, 309, 

 310,354, 369, 376, 379, 3S2, 388,391,407,408 



Actinolite-magnetite-quartz rock, origin of S34-841 



photomicrograph of.. ._ 836 



Actinolitic marbles, origin of _ 833 



Adams, F. D., figures cited from 674,814 



on deformation of quartz grains in rocks 695 



on granulation and recrystallization as affected 



by water content of rocks 742 



on mechanical granulation of anorthosite 675 



on rock flowage by granulation 759 



Adams, F. D., and Barlow, A. E., on schist conglom- 

 erates 859 



Adams, F. D., and Nieolson, J. T., on deformation 



of calcite crystals 675 



on deformation of marble under pressure 49,670, 



681 , 696, 747, 772, S09, 811, 812, 814, 815, 816, 1012 



on mobility of calcite 754 



Adams, G. I., on chert beds of Missouri 851 



Adaptation of minerals to environment, illustra- 

 tions of.. 33-34 



Adhesion, influence of, in ground-water circula- 

 tion 150-152 



Adsorption, phenomena of __ 64-65,121 



^girite, chemical and physical constants of 195 



Aggregation, state of, in rocks, effect of, on rate of 



weathering 533-534 



Agriculture, effect of, on ground-water level ._ 427 



effect of, on run-off. ..-_ 415 



on soils - 451 



Aikman, C. M., on nitrogen compounds, decompo- 

 sition of _ 465 



Page. 

 Aikman, C. M.,on nitrogen, fixation of , by bacteria. 453 

 on nitrogen precipitated from the air, amount 



of... 453 



on oxygen in soils, amount of ■ 470 



on reduction of nitrates to nitrites 472 



on temperature at which bacteria show maxi- 

 mum activity 466 



Air, chemical composition of 944 



See also Atmosphere. 

 Albite, alteration of, to analcite and quartz, volume 



changes produced by... 632-633 



alterations and alteration products of 260-265, 



366,372,375,398,400,404 



chemical and physical constants of 195,259 



sources and mode of formation of . 260,261,265,274,281, 

 294, 333, 334, 335, 366, 369, 375, 376, 377, 384, 386, 

 388, 389, 392, 393, 396, 397, 400, 404, 405, 406, 407 

 Albite and anorthite, alterations and alteration 



products of 375,376.377,397,398 



Albite and gibbsite, alterations and alteration prod- 

 ucts of _ 375,400 



Albite and halite, alterations and alteration prod 



uctsof _. 375,400 



Albite, anorthite, and leucite, alterations and alter- 

 ation products of . . 375,376,386,397 



Albite, anorthite, and microcline, alterations and 



alteration products of 389 



Albite, anorthite, and orthoclase, alterations and 



alteration products of 375, 377, 3S9, 404 



Albite-gneiss, photomicrograph of 902 



Albite-schist, thin section of 704 



Alfalfa, disintegration of rocks by 445 



Alkalies, decomposition of, in rock weathering, 



order of... 536 



in arid regions, accumulation of 545-546 



in soils, amount of, necessary to prevent agri- 

 culture 543 



migration of, to surface, process of 546 



prevention of deposits of 543 



suscepti bility of, to weathering 532 



Alkaline rocks, susceptibility of, to weathering.. 532-533 



Allanite, alterations and alteration products of 323 



chemical and physical constants of 195,320 



occurrence of 322 



Allophane, chemical and physical constants of . . . 195, 254 



sourcesand mode of formation of ._ 369,389 



Almandite, alterationsand alteration products of. 372, 375 



chemical and physical constants of 195,299 



occurrence of 300-301 



Almandite and pyrope, alterations and alteration 



productsof 375,383,390,401,404 



Almandite, melanite, and pyrope, alterations and 



alteration products of . . 375, 383, 387, 390, 396 



1245 



