102 T. L. WATSOX WEATHERING OF GRANITIC ROCKS OF GEORGIA 



sidered as essential factors. The foUowiuo- tabular statement shows the 

 percentage or ratio of absorption for the Georgia granites, determined 

 i)}^ the writer in the laboratory of the State surve}' : 



T^^„,;.„ Gain in Jib- Percentage 



j.oeaury. sorbed water, of absorption. 



The Cliarley Rocker quarry, Hancock county 



Tlie Sparta quarry, Hancock county 



The Lexington Blue Granite quarry, Oglethorpe county. 

 The Diamond Blue Granite Company's quarry, Ogle- 

 thorpe county 



The Swift and Wilcox quarry, Elbert county 



The Wright place, Elbert county 



Tate and Oliver quarry, Elbert county 



Coggin's Granite Company's quarry, Elbert county. . . 



The Childs's quarry, Elbert county 



The Snell quarry, Gwinnett county 



The Linch quarry, Putnam county 



Greenville Granite Company's quarry, Greenville 



The Odessa quarry, Meriwether county 



Stone Mountain Granite quarries 



Arabia Mountain Granite (piarries 



Pine Mountain Granite quarries 



The fact that granitic rocks may undergo extensive disintegration 

 with l)ut slight decomposition has been emphasized b}'^ several writers.* 

 Numerous cases where the rocks have been resolved into residual pro- 

 ducts from disintegration with little decomposition, and also where 

 decomposition follows so closely on disintegration, the former greatly 

 predominating, are well illustrated among the various types of the 

 Georgia granites. The data are yet insufficient, however, to draw any 

 definite conclusions concerning the difference in weathering, if there be 

 an3\ between the fine and coarse grained granites of the state ; that is, 

 to state definitely whether the coarse grained varieties suffer mainly from 

 disintegration and the finegrained ones b}'' disintegration closely followed 

 b}'^ decomposition. 



The early stages in the processes of weathering, as elsewhere pointed 

 out in this paper, for each tj^pe, fine and coarse grained, of the Georgia 



••Voyage of the Vega, 1881, vol. ii, p. ■420. Quoted by Merrill, Geo. P., op. cit., p, 242. Bull. Geol. 

 6oc. Am., 1895, vol. 6, pp. 321-332; also, Rocks, Rock Weathering, and Soils, 1897, pp. 206-213; Rocks, 

 Rock Weathering, and Soils., 1897, p. 243. 



0.04 



0.037 



0.04 



0.049 



0.08 



0.092 



0.11 



0.088 



0.08 



0.090 



0.09 



0.092 



0.08 



0.098 



0.15 



0.090 



0.17 



0.092 



0.10 



0.075 



0.04 



0.060 



O.ll 



0.086 



0.05 



0.056 



0.01) 



0.067 



0.04 



0.050 



0.0() 



0.073 



