46 Dr. Verchere on the Geology of Kashmir, [No. 1, 



and it appears therefore impossible to regard them otherwise than 

 as accumulations of debris washed from the ranges into the great 

 troughs between these ranges, and therefore posterior to the great 

 final upheaval of the Himalayas. 



Very little is known of the nature of the rocks forming the ridges, 

 ranges and spurs in Saltoro, Nuha and Shayokh. Dr. Thomson,* 

 on native information (Izzet Ullah), tells us that the rocks of the 

 Shayokh and Nuha valleys are in great part primitive limestone. 

 " The limestone continues towards Rodok and the water of the Pang 

 Gong Tso (lake) hold a sufficient quantity of lime to form a cal- 

 careous deposit which cements the pebbles together in patches of 

 concrete at the bottom of the lake." The water of the Pang Chong 

 Tso is sufficiently brackish not to be fit for drink, and it has a bitter- 

 ness probably due to sulphates of Soda and of Magnesia. From the 

 examination of a specimen of the calcacerous incrustation which is 

 formed on the shore of the lake, I found that Magnesia is about as 

 abundant as lime. 



An extremely pretty species of Limnea or rather Physa once lived 

 in the lake, and dead shells of it are abundantly found in the band 

 of tufaceous deposit, a few feet above the present level of the water. 

 These shells no longer exist in the lake (Austen). They have pro- 

 bably been destroyed by the diminution and concentration of the 

 brackish water. 



G-eneral Cunningham informs usf that the rocks of all the high 

 ranges and peaks of Rodok are granite and gneiss, and this appears • 

 to be highly probable. Metamorphic rocks also abound ; the ! 

 mountains near the Pang Chong Tso containing a great deal of | 

 mica-schists ; and crystalline marble is also found on the shore of the ! 

 lake, apparently in immediate contact with granitoid rocks. 



In the northern portion of Rodok some hot springs exist in a 



locality called Chong Chin Mo ; there water deposits largely a grey ' 



tufa which is composed of carbonate of lime, sulphate of lime and 



sulphate of soda. Such tufa is common near the warm springs of 



the saliferian in the Punjab. Its composition is also that of the 



saline impurities of the brackish lake of Tso Moreri in Rukshu, and 



# '* Ladak," by General Cunningham, E. E. 

 f " Ladak," by General Cunningham, R. E. 



