Il6 GEOLOGY OF THE SON VALLEY, ETC. 



To the north-west of the Barhatola the white quartzitic sand- 

 stones again contain a rock very similar to one that is found among 

 the basement beds of the lower Vindhyans in the exposure to the 

 north. It is a very peculiar rock, composed of white quartz 

 reticulated through a ferruginous. argillaceous matrix, which weathers 

 into a vesicular quartz rock by the disappearance of the other 

 constituent. 



A group of small outliers in the comparatively low ground near 

 Bholahra may be conveniently noticed here, 

 They are of small size and being exposed at 

 a low level where there is not the free drainage, which the main 

 exposure has on account of its greater elevation, they are not 

 surrounded by scarps, but form low hills covered with a deep layer of 

 loose gravel. 



One more outlier may be mentioned here, which caps the hills 

 east of the Samdin and north of Sejari. It contains some coarse 

 conglomerate, and at its western extremity I found the only boulder 

 of crystalline gneiss which I have seen in these beds. 



In the Kharara valley and to the south of Pansrer the transitions 

 Transitions of the Sam- consist of phyllites and quartzites with nu- 

 dm valley. merous small outcrops of an intrusive diorite, of 



which some larger exposures are seen near the villages of Bhanni- 

 Bhowraha (Bhaoraha), and east of Garu. To the north of these 

 intrusions is a band of volcanic rocks, extending to the northern 

 boundary of the transitions. Ashes and amygdaloidal lavas are 

 easily recognizable in spite of the alteration they have undergone, 

 by which most of the beds have been transformed into a more or 

 less hornblendic green-coloured schistose rock, while other beds 

 have been largely converted into epidote. 



North of Deori is a range of scarped, craggy hills, especially 

 conspicuous when seen from the north, which run north-eastwards 

 from the neighbourhood of Ghara. On the north they are in contact 

 with felspathic quartzites which have decomposed to a soft kaolin 

 rock, and to the south are decomposed quartzose beds, some white, 

 ( n6 ) 



