78 W. BLANFOllDj WESTERN INDIA. [PaIIT II. 



South-west of Bhopal the boundaries of the Vindhyans and the 



trap are very irregular^ the trap having evidently 

 Hills of trap and 



Vindhyans, south-west of been poured out upon a very uneven surface of the 



Bhopal. 



sandstone, a surface probably produced by the 



unequal action of subaerial denudation. Some hills are of one rock, some 



of the other, but the distinction between the two may be seen at a 



glance, in consequence of the difference in form and colour, between 



the rocks of the two groups, and in the vegetation growing upon them. 



The Vindhyan hills are rocky, generally escarped on one side, and 



sloping away at an angle of 5° to 7° on the other, they are purplish 



in colour, bare of grass and covered with thin jungle. The trap 



hills are flat-topped, blackish in colour and covered with scrub 



jungle and long grass, shewing the great amount and richness of the 



soil derived from the basaltic rocks. The Vindhyans stand out, as a 



rule, in higher hills than the trap, owing to the manner in which they 



resist disintegration. 



Further south the boundaries between the two rocks are well marked 



and regular, the Vindhyan area, which stretches 

 Western boundary of . . 



Vindhyans, south of away to the east, terminating abruptly about 



12, miles west of the road from Hoshungabad to 



Bhopal. South of Shumsgurh, the Vindhyans rise in a bold cliff'-like scarp 



from the comparatively flat plain of the traps. So steady and regular is 



this scarp that it has very much the appearance of being along a line of 



fault, for the older rocks are found along it higher in position and dipping 



away from the newer.. But it appears more probable that the 



escarpment existed previously to the formation of the trap, and that 



the lava flows, now consolidated into that rock, 



Vindhyan escarpment 



probably pre-trappean. fiWed up a great hollow worii out in the Vind- 

 hyans. In favour of this view are several facts. 1. — The changes 

 which take place in the direction of the scarp, such changes being 

 unusual in faults, although they do occasionally occur. 2. — The absence 

 of any disturbance of the beds near the junction. Such would probably 

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