40 GEOLOGICAL NOTES ON ASSAM. 



scarpj and reaching to various heights, there is a narrow zone of low 

 broken hills. In this ground the upper beds of the Cherra section are 

 found in various states of disturbance; sometimes horizontal for a short 

 space, sometimes locally much broken or contorted; occasionally so 

 near the base of the scarp as to necessitate the supposition of faulting. 

 As a rule they have a southerly dip ;* and the successive stages of 

 the series appear at their due distance from the axis of flexure, all 

 being represented. Looking east by south from the scarp at Terria Grhat, 

 there is an excellent view-section of what I consider to be the normal 

 form of the feature. There seems to me to be nothing in these condi- 

 tions to call for, or even to admit of the introduction of, any great 

 feature of dislocation depending upon general causes. The induced 

 phenomena of disturbance seem to link themselves most naturally to the 

 original conditions of formation ; the comparatively light accumulation 

 upon a firm basis of crystalline rocks has escaped the crushing from 

 settlement or otherwise, which has pervaded the deeper deposits beyond. 

 As might be expected, it is in this part of the section that we find the 

 youngest rocks of all. The denudation which in the western region has 

 cut back nearly to the scarp of the horizontal rocks, appears to have 

 been less and less effective to the eastward. At Burr Ghat Mr. Oldham 

 observed that, " resting upon the low-lying limestone, there occurs a great 

 thickness of sandstones of varying characters, with intercalated shales/''t 

 These are, in fact, the rocks which still more to the east form the Burrail 

 [great ridge) range. 



A single name for the well defined hill-mass separating the plains 



^. ,. ,. , , of Svlhet and Cachar from the Bramahpootra 



Distinctive structures -^ ^ 



of the hill regions. Valley, is a decided want in geography, whether 



physical or simply topographical. Elsewhere, hills of far less magnitude 

 and extent, and very much less defined in boundary, have long since 



* Mem. Geological Survey, India, Vol. I., p. 167. 

 t Mem. Geological Survey, India, Vol. I., p. 133. 



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