92 F001E: GEOLOGY OF THE BELLARY DISTRICT. 



acutely towards either end. 1 East of the Sandur hills lies an irregular 

 tract ot Dharwar rocks which 1 will call the Joga-Snltanpur area (B), 

 partly hilly and partly level, which forms the connection — the bracket, 

 as it were — which unites the Sandur synclinal with the Copper moun- 

 tain. The eastern synclinal is the long narrow rocky ridge, the highest 

 part of which is called by Europeans the Copper mountain (C), because 

 prospected for copper in the days of Tippoo Sultan. It measures 

 32 miles in length by from 2 to 4I in width. 



(A). — The Sandur hills enclose a long narrow valley which is 



The Sandur syncli- sim P le in its northern part, but to the south 

 nal - divided into two lesser valleys by a high but 



narrow- spur — the Devadara ridge — which seemingly belongs to the 

 western side of the synclinal fold. The structure of the synclinal 

 fold itself is by no means simple. It is much confused by the extra- 

 ordinary thinning out of most of the rocks composing it, by sundry 

 faults, and by great inversions on the eastern side of the fold. When 

 seen from the south-west or north-east the Sandur hills present a 

 remarkably flat-topped appearance, and it is difficult to imagine that 

 they really surround a median valley. Where the synclinal attains 



The Narihalla and its its greatest width it is cut across by the valley 

 two gorges. excavated by the Narihalla, a small river rising 



some distance to the south-west of the synclinal. The direction of 

 the cutting thus made is from south-west to north-east, and the river 

 in eroding its way through the great barrier has cut two very fine 

 gorges which afford easy approaches to the Sandur valley and give 

 excellent sections of the great side ridges. The western of these 

 gorges is known as the Obla, or Ubala Gandi ; the eastern as the 

 Bhima Gandi. A third pass at the northern end of the synclinal also 

 allows of easy access to the valley, but fails to give any useful section 

 of the rocks in that part. 



3 The extreme north-west end of the Sandur synclinal lies on the left bank of the 

 Tungabhadra in Sir Salar Jung's jaghir of Koppal Drug in the Nizam's State, where it 

 forms a narrow ridge, the continuation of the dark trappoid, which crosses the river and 

 extends 4 or 5. miles north-west from the river. 



( 92 ) 



