Notes on Geology and Mineralogy of Afghanistan. 573 



for the whole tract of country from Pisheen to beyond the 

 river Helmund is strewed over in the vicinity of the Hills 

 with pebbles similarly rounded, and the same holes and 

 caverns occur in the limestone rocks in places where it is 

 utterly impossible that any lake could have existed, and at 

 heights on the mountains far beyond the reach of any waters 

 save those of an universal inundation. That deep waters 

 have at some remote period been in violent agitation over 

 these parts, the vast accumulations of boulders and conglo- 

 merate sufficiently attest ; but at the same time the magni- 

 tude of such accumulations and the conformable position 

 in which they lie, at once forbid the supposition that the 

 effects now apparent were produced by the transient pas- 

 sage of modern lakes and torrents. 



Taking a retrospective view of what has already been 

 noted, the following series of rocks would appear to com- 

 pose the mountains intervening between the valley of Quettah 

 and Dadur. At the entrance to the Bolan Pass from the 

 Quettah side, we first come upon limestones of compact tex- 

 ture containing various marine fossils of the genera Echinus, 

 Gryphcea, Isocardium (}) and others. This rock is pro- 

 bably equivalent to the mountain limestone of Europe, an 

 opinion which is strengthened as we proceed by finding 

 numerous alternating strata of variously coloured indurated 

 clays and bituminous shale yielding traces of coal; while 

 near the latter, in the bed of the Pass, although not in situ, 

 we find detached masses of yellow ferruginous clay stones 

 yielding a large proportion of iron, and imbedding carbo- 

 nised fragments of plants : this, together with other speci- 

 mens of brown carbonate of iron, is a still farther proof that 

 the strata belong to the true coal formation. Again, at 

 Ab-i-goom, in the bed of the Pass but not in situ, were 

 found specimens of true oolite, one of which appears to be 

 very similar to the fine-grained oolite at Bath, while others 



