CONTENTS. 17 



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

 Metainorphisni in the belt of weathering — Continued. 



Relations of disintegration to decomposition and solution — Continued. 

 Regions favorable to prominence of decomposition — Continued. 



Regions of moderate topographic relief 502 



Regions of abundant plants and animals 503 



Regions remote from the sea 504 



General statements v 504 



Change in chemical composition of the rocks 507 



Order of decomposition of the minerals, and the end products 518 



Total gains and losses in weathering, and changes in volume 522 



Emphasis and retention of structures and textures 524 



Obliteration of structures and textures 526 



Surfaces of weathering 527 



Depth and degree of weathering 529 



Rate of weathering 532 



Forces and agents at work in weathering. 532 



Materials weathered 532 



Chemical composition 532 



Mineral composition 533 



State of aggregation 533 



Thickness of the belt of weathering 534 



Stage of weathering 535 



Distribution of dissolved materials 536 



Material abstracted by plants 537 



Material transferred to belt of cementation 538 



Material permanently abstracted by run-off 53S 



Material dissolved, transported, and reprecipitated in belt of weathering 539 



Concentration at and near the surface 543 



Concentration by underground circulation 543 



Concentration by circulation mainly confined to belt of weathering 544 



Concentration by circulation extending into belt of cementation 550 



Concentration by overground circulation ., 551 



Distribution of residual materials 554 



Relations of belt of weathering to sedimentary rocks 555 



Belt of weathering the source of sedimentary rocks 1 555 



Material transported in suspension 556 



Material transported in solution 557 



Material transported in suspension and solution 558 



Rocks produced from material of belt of weathering without transportation to the 



sea 559 



Transition between belt of weathering and belt of cementation 560 



Chapter VII. — The Belt of Cementation _ 562 



Belt of cementation defined 562 



Boundaries of belt of cementation 565 



MON XLVII — 03 2 



