158 Bulletin of Laboratories of Denison University. [v-i. xii 



Petit creek, one of the principal str^ans in the area 

 mapped, takes its rise in the Conasau^a shales some 10 miles 

 north of Cartersville, and maintains its entire coiirse southward 

 to the Etowah river on the soft shales. 



In lithologic character, the shales vary fro""m very fine- 

 grained aluminous or clayey rocks to somewhat siliceous shales 

 and sandstone, with the aluminous type predominant. Numer- 

 ous exposures show interlayered thin- and thick-bediled lime- 

 stone with the shale. In color, the shales vary from light-dr.ib 

 and yellow to dark blue slaty, best described, as a whole, as 

 oHve shales. The weathered shale is usually tinted some liglit 

 shade of red, in marked contrast to the deep red decay of the 

 limestone. The shales are much fractured and crushed from 

 the effects of intense pressure metamorphism. The thickness 

 of the formation is placed between 1500 and 3000 ft. 



The following analyses give a general idea of the chemical 

 composition of the shales in this region : 



Analyses of Middle Cambrian Shales, Cartersville District, 



Total, - - 100.54 99.67 100.19 100.15 9967 



