l82 FOOTE: GEOLOGY OF THE BELLARY DISTRICT. 



north-eastern corner of Adoni taluq, Its surface is largely mixed 

 with and much concealed by cotton soil. 



To the alluvial formations must be reckoned the remarkable fan- 

 like deposits of coarse and fine d6bris brought 

 fa Talus and Torrent down and spread out over t he face of the 



country, but most markedly along the northern 



flanks of the Copper Mountain ridge, where they form an almost 



continuous fringe. They are more especially well developed along 



the northern base of Sugammadevibetta, the Copper Mountain itself. 



They are well seen from many points to the north of the railway. 



Their northern limit and their relation to the existing streams 



draining the various ravines opening from the 

 Tbeir limits. .... . . . . ... 



main ridge is very obvious to every intelligent 



observer. It is easy to see how they have been formed by the streams 

 to which they owe their existence. These streams have carried 

 quantities of debris, chiefly sub-angular in shape, in flood times, and 

 spread them over the open country just outside of the ravines. The 

 deposits thus formed compelled the streams to shift their courses some 

 distance laterally on one side or the other, as the case might be, 

 each time that they descended laden with fresh supplies of debris. 

 In time they had blocked up the mouth of the ravines giving them 

 exit from the range. When thus dammed back, they either flowed 

 over the dams they had formed and raised them yet more over their 

 former level and extended the deposit into fan-shaped accummu» 

 lations so-called " cones of dejection/' or else they burst through 

 their former deposits and cut channels through them and recom- 

 menced forming other fans or cones, generally on a smaller scale 

 at lower levels further out in the plain. 



By the action of local torrents suddenly created by intensely 



heavy sporadic rain storms other fans have been 



formed and the detritus of the old hill-foot fans, 



and of the ordinary talus accummulations distant from any ravine 



stream, have been moved away far from the hills they were originally 



derived from. 



( 182 ) 



