SOIL-FORMING PROCESSES 



27 



23. Special cases of weathering. The weathering of 

 granite and limestone under different climatic conditions 

 has already been compared. The changes that take 

 place in these rocks as they are evolved to residual clays 

 may now be considered. The following analyses serve 

 to show on what elements the losses are likely to be most 

 serious during the process: 



FRESH GRANITE AND ITS RESULTANT CLAY 1 



VIRGINIA LIMESTONE AND ITS RESIDUAL CLAY 2 



1 Merrill, G. P. Bui. Geol. Soc. Amer., Vol. 8, p. 160. 1879. 

 2 Dille*, J. S. U. S. Geol. Survey, Bui. 150, p. 385. 1898. 



