LOWER TRANSITION ROCKS. gi 



tanhalli hill (2,440') which rises some 400 feet above the surround- 

 ing country. The hill being very bare of vegetation, the disposi- 

 tion of the quartzites is very distinct, and they are seen to dip from 

 2 5° ^ 30 east. They are overlaid by schists and rather flaggy 

 argillites, which, as above mentioned, are faulted against the gneiss 

 to the eastward. 



In the northern part of the band the quartzite conglomerates do 

 not appear. They seem to die out in the hill east of Uchingi 

 Drug. At Giddanapalli (Giddanaganpully) green brown schists of 

 the same character as those at Chettanhalli, and similar schist with 

 traces of a black trappoid, are to be seen also between Nitchapur 

 and Degga Bassapur. 



One very large trap dyke in the centre of the side band cuts across 

 the south flank of the hill east of Uchingv 

 Great Trap dyke. v iii age> and continues north-west for some 4 or 



5 miles, forming a conspicuous feature in the landscape. 



Several good-looking and promising reefs of bluish quartz run 

 northward through the pebbly quartzites north 

 yuar zree s. o £ ^ e Chettanhalli tank. They are worth pro- 



specting as the central part of the side band at Halekal gudda, in 

 Mysore, was found to be very fairly auriferous. 



j. — The Sandur hills and Copper mountain band. 



This area is so strangely irregular in shape that it can hardly 

 be described as a band, but rather as a couple of bands bracketed to- 

 gether near their respective centres. Both stand out high above the 

 surrounding country, but sink down low at their extremities, more 

 especially at their northern ends. The two minor bands thus coupled 

 may be regarded as two great synclinal folds running from north-west 

 to south-east. 



The western of these two great synclinals forms the Sandur hills 

 (A), a group of remarkable flat-topped masses occupying in plan a 

 leaf-shaped area 32 miles long and 11 broad in the centre, and tapering 



( 91 ) 



