1842.] of the Himmalay a Mountains. cxv 



to be singularly subject to atmospheric wear ; the consequence of this 

 difference of durability is the projection of these veins on the surface 

 of the rock, giving it a singularly rugged appearance. It is probable 

 also, that particular parts of the rock not veinous in appearance, 

 partake of this durability, and thus occasion that nodular aspect so 

 characteristic of this limestone. 



251. Is there any connection between a primary limestone with 

 veins of flint, and the chalk strata enclosing rolled pebbles of the same 

 mineral ? The occurrence of flint pebbles in chalk has always appeared 

 amongst the wonders of geology to the uninitiated. The difference of 

 composition between chalk and primary limestone is perhaps as great 

 a one, and not a little difficult to account for. The primary lime- 

 stones we see, however, are subject to a caries, which as far as it goes, 

 produces a perfect chalk. In that state it is obvious that the action of 

 any of the numerous causes of the disintegration of rocks will be more 

 powerful. If we then suppose that the flint being set loose, splits into nu- 

 merous fragments of all sizes, and will, by the same cause that trans- 

 ports the loose chalky matter, be worn down on its edges and at last 

 rounded, we shall perhaps have an explanation not at all improbable. 

 If this be not an exact account of the phenomena, it at least, by shewing 

 how natural and simple the process which might have produced the 

 actual state of things, serves to take off some of the edge of our wonder. 



252. In descending to the Surjoo from Goon, we find argillaceous 

 schist occasionally of the same character as that observed in the ascent 

 to the Thakil Peak, (greywacke schist.) It is, like that, of a dark grey 

 colour approaching to black, and is remarkable for splitting into pris- 

 matic fragments on being struck. A good deal of calcareous stalagmite 

 occurs, and a soft white or light grey schist, intermediate between clay 

 slate and talc slate. Latterly, limestone is abundant, and in the bed of 

 the river we have gneiss and quartz rock, with fragments of hornblende 

 rock in addition to those of limestone and the two preceding. The 

 gneiss continues from the bridge upwards, at first of a fine grain after- 

 wards coarser, and containing superadded amygdaloidal concretions of 

 felspar, similar in fact to the type described, Art. 80. Beds of mica slate 

 and of quartz rock are contained in it ; the latter furnished the only ob- 

 servation of the dip which was S. 30° E. and inclination 60°. At Burakot, 

 argillaceous strata again prevail, and furnish some very anomalous rocks 



