Chap. IV.] nahun and sivalik groups. 129 



There are other features in the section of the Noon which more 



Doubtful distinction of strongly illustrate the remarks just made. We 

 superficial' deposits. haye geen ^ the gection ftt Simbuwala> which 



is but a type of that to be found all along the range south of the dun, 

 that the strata conformably capping the Sivalik series are continuous 

 with those found quite undisturbed in the dun, even up to the contact 

 with the inner band of lignite sandstone. This fact shows the difficulty 

 that must arise in attempting to separate Sivalik strata from superficial 

 deposits. In the Noon section, however, we find, at least, two distinct 

 deposits, resting upon the edges of the inverted strata which I have just 

 now identified as upper members of the Sivalik series. The east and 

 west reach of the Noon flows along the steeply scarped edge of a terrace 

 which slopes off southwards into the general surface of the dun. The 

 upper part of this terrace is composed of coarse and fine, more or less 

 angular, debris of limestone and slates, — the debris of the mountain to 

 the north. This deposit is often cemented by tufa; it attains in many 

 places a thickness of several hundred feet, and along the flanks of the 

 main hills reaches an elevation greater than the actual summits of the 

 Sivalik hills. It forms, in fact, the talus which at several places conceals 

 all outside the older rocks. Even for this deposit I hesitate to conjec- 

 ture that it has not its representative among the disturbed rocks of the 

 Sivalik range ; for example, some of the beds on the north of the 

 Bheemgoda fault are very similar to it in composition. Under it, in the 

 terrace of the Noon, we find a highly contrasting deposit, — a coarse 

 boulder-conglomerate of a light ochreous colour : the blocks are all 

 of the harder rocks, and must for the most part belong to distant 

 rocks. It does not exactly resemble any of the Sivalik conglomerates 

 that I have seen, and it has some resemblance to the mass already noticed 

 not far from this, in the Soma, associated with the vertical rocks of the 

 Nahun band, near the main boundary ; in this latter, however, the 

 pebbles and blocks are, I think, more exclusively of the harder schistose 



