SCHISTOSE AftEAS. .23 



great quartzite series forming the Pieherlakonda (page 14). The 

 quartzites have disappeared apparently by change of mineral character, a 

 Rocks masked by de- phenomenon they often show, but in this case the 

 bns of vem quartz. probable connection with the chloritic schists 



cannot be traced owing to the enormous amount of quartz debris which 

 covers the entire surface of the country hereabout. The immense quan- 

 tity of this quartz debris, which is derived from the small quartz veins 

 traversing the various schists, shows how great the denudation the 

 schists have undergone in recent times. The chloritic rocks are exposed 

 only in a few well-sections. 



Crystalline limestones are developed to a very small extent in the 



Nellore-Kistna gneissic area, and were seen but in 

 Crystalline limestones. 



a few places. Of those noted, the most important 



occurs at a little distance south-west of Chundi. It occurs on the western 

 slope of the ridge west of Chundi valley, where crossed by the path to 

 Ramalirjgapuram. The limestone, which is of grey colour speckled with 

 small scales of mica, and of saccharoid texture, forms a bed 4 to 5 feet 

 in thickness. The outcrop was not traced to any great distance, owing 

 to its being covered by scrub jungle and talus of the higher lying quartz- 

 ite beds. This limestone contains slight traces of copper in the shape 

 of copper pyrites. 



Numerous fragments of crystalline limestone of pale grey and pink 

 Near Pedda Allavala- colours were observed on the high ground about 3 

 p miles north-east of Pedda Allavalapad, but the bed 



whence they were derived was not seen. Probably it is hidden by the 

 extensive spread of cotton soil which there covers the face of the country. 

 This limestone contains numerous crystals of black tourmaline and some 

 small irregular inclusions of dirty white weathered felspar. Precisely 

 similar tourmaline crystals are very common in numerous small irregular 

 granite veins which traverse the hornblendic granite gneiss near by. 



A bed of sub-crystalline whitish limestone occurs east of the village of 



Pedda Arikatla, 8 miles north-by-east of Kani- 

 Near Pedda Arikatla. . . .. 



gin. But little is seen or his bed owing to a 



( 23 ) 



