CONTENTS. 15 



Chapter V. — Minerals — Continued. 



Section 4. General statements — Continued. 



Physical-chemical factors upon which nature of alterations depends — Continued. 



Chemical composition 359 



Chemical composition of adjacent minerals 359 



Chemical composition of circulating solutions 359 



Specific gravity 360 



Symmetry 360 



Specific gravity and symmetry 361 



Heat reactions 362 



Pressure and volume 363 



Reversible reactions 366 



Section 5. Tables 369 



Table A. Sources of minerals 369 



Table B. Alteration products of minerals 372 



Table C. Chemical reactions and volume changes . . _ _ 375 



Table D. Classification of alterations, with volume changes 395 



Chapter VI. — The Belt of Weathering 409 



Belt of weathering defined. 409 



Form of level of ground water 411 



Amount and source of water in belt of weathering 413 



The circulation 416 



Downward movements of water 417 



Upward movements of water 419 



Molecular attraction 419 



Vegetation 422 



Variation in level of ground water 423 



Precipitation, seepage, and evaporation 423 



Uplift and subsidence 426 



Denudation and valley filling 426 



Influence of man 427 



Barometric pressure 428 



Temperature -■ 428 



General statements - - - 429 



Metamorphism in the belt of weathering _ 429 



Variable materials and conditions of belt of weathering 429 



Mechanical work .. 431 



Water, ice, and wind 432 



Change in temperature 434 



Change from water to ice 440 



Plants 444 



/ Lichens, mosses, etc 444 



Cacti - 445 



Grasses, grains, and vegetables 445 



Shrubs and trees 445 



