1 6 CONTENTS. 



Chapter VI. — The Belt of Weathering — Continued. Page. 

 Metamorphiam in the belt of weathering — Continued. 

 Mechanical work — Continued. 



Animals 447 



Earthworms 448 



Ants, termites, and other insects 448 



The larger burrowing animals 449 



Man 450 



General statements 451 



Chemical work 4.51 



The agents 452 



Plants 452 



Plants, alive _ 452 



Plants, dead, and bacteria 455 



Animals _ 456 



, Animals, alive 456 



Animals, dead, and bacteria 457 



Work of solutions 457 



Joint work of agents of weathering 461 



Oxidation 461 



Oxidation of organic compounds 461 



Oxidation of carbon and hydrogen 461 



Oxidation of nitrogen 465 



Oxidation of inorganic compounds 466 



Iron 467 



Sulphur 468 



General statements 469 



Carbonation 473 



Hydration and dehydration 481 



Oxidation, carbonation, and hydration 483 



Solution 484 



Deposition 487 



General statements 487 



Contact metamorphism 48S 



Direct contact effect 489 



Indirect contact effect, or work of f umaroles and solf ataras 490 



Relations of disintegration to decomposition and solution 494 



Regions favorable to prominence of disintegration ■ 496 



Arid regions 496 



Regions of high latitude 498 



Regions of marked topographic relief 499 



Regions of sparse plants and animals . . 500 



Regions near the sea 500 



Regions favorable to prominence o f decomposition 501 



Humid regions 501 



Regions of low latitude 502 



