70 LA TOUCHE : GEOLOGY OF WES1ERN RAJPUTANA. 



and to the south-east they are covered by alluvium ; one or two small 

 patches of the rhyolite which probably underlies them occur in this 

 direction about two and a half miles away on the banks of the Sukri. 



A few miles to the west of Pati a considerable range of hills runs 

 due north and south for about n miles, rising to an altitude of 2,1 12 

 feet above the sea at its highest point close to the town of Bhadrajun, 

 which lies in a narrow ravine on the eastern side of the range near its 

 southern end. The whole of this range consists of various types of 

 rhyolite. To the north of the village of Goendla, about the middle of 

 the range, the prevailing rock is a strongly porphyritic dark coloured 

 rhyolite, with white or red crystals of felspar, with a general westerly 

 dip. At the base on the east side some nodular and sphaerulitic 

 flows are exposed in places, and near the village of Bakhal, at the 

 north end of the range, is a highly concretionary bed, the concretions 

 in which reach a diameter of at least two feet (PI. V, fig. 2). At 

 Goendla itself some ashy beds containing small lapilli of rhyolite as well 

 as rounded blocks up to 10 inches in diameter, associated with fine 

 grained reddish tuff, are exposed in a watercourse at the foot of the 

 hills. Above these come some strongly porphyritic rhyolite, and then 

 thick flows of compact dark grey rhyolite, forming precipitous scarps 

 facing east. These are succeeded by the porphyritic rhyolite continued 

 southwards from the northern end of the range, the whole of the 

 slopes on the western side being formed of this rock. To the south 

 the compact rhyolites rise into the high craggy hills above the town 

 of Bhadrajun and form the greater portion of the southern end of the 

 range. Some of the flows exhibit very well developed flow-structure. 

 Brecciated beds occur on. the southern side of a pass through the 

 range south of Bhadrajun, and are intercalated with the rhyolites. 

 '1 he whole of the rocks dip at various angles in a westerly direction. 



About four miles to the west of this range another chain of small 

 hills runs parallel to it for about six miles from north to south. These 

 hills all consist of the coarse micaceous granite, but are quite isolated, 



( ;o ) 



