1866.] the Western Himalaya and Afghan Mountains. 103 



of albite sometimes become loosened in their matrices, and, falling 

 out, leave angular cavities on the face of the rock. The rock, 

 when fresh and well crystallized, is however very hard : some 

 varieties appear to crumble much more quickly and completely than 

 others. 



II. — The grains of magnetic iron ore and the gold I have not seen 

 in the porphyry,* but they are found in the sands which, I will now 

 endeavour to prove, have been formed by the decomposition of these 

 volcanic rocks. 



Gold is washed in most of the rivers which traverse the miocene 

 sandstones and conglomerates of the sub- Himalaya, and is always 

 found associated with grains of magnetic iron ore. Let us examine 

 one of the districts where the washings are, I believe, most abundant, 

 the banks of the Sonne river, in the districts of Jheelum and 

 Rawul Pindee, especially near the villages of Pindeh Geb, Kothair 

 and Mukud. Let us therefore go to Rawul Pindee and travel towards 

 the S. W. along the road to Kalabagh. We find that this dreary 

 road, about 120 miles long, crosses obliquely from the N. N. E. to the 

 S. S.' W. the great plateau of miocene sandstone, conglomerate 

 and clay (Sect. G.). 



There is a thick bed of miocene sandstone and conglomerate, 

 above 2,000 feet thick, which might be called the upper miocene 

 formation of the Sub-Himalaya (contemporary of the Sewalik hills 

 and containing the same Mammalian fossils), whilst the sandstone 

 and shales of Murree and adjacent hills, about 5,000 feet thick and 

 without fossils, might be regarded as the inferior miocene. These 

 two divisions of the miocene are not exactly one on the top of 

 the other, but rather the upper bed thinning towards the north, 

 covers in the southern edge of the lower bed in an intricated 



* A similar granitoid porphyry exists in Portugal, in the hills near Cintra 

 about five leagues from Lisbon. It is there very variable in appearance and 

 consistency, and is generally made up of large grains of felspar and of quartz, 

 and of large plates of mica. It contains grains of magnetic iron ore, but I am 

 not aware whether it contains the large twin crystals of felspars seen in the 

 Kaj Nag porphyry. The Portugal rock is generally described by travellers as 

 granite, but is considered by geologists as decidedly volcanic. It presents 

 the character of crumbling easily after a certain amount of exposure. 



