MEMOIRS 



OF 



THE GEOLOGICAL SURVEY OF INDIA, 



Petrological notes on some Peridotites, Serpen- 

 tines, Gabbros, and associated rocks, from 

 Ladakh, North-Western Himalaya, by Lieut.- 

 General C. A. McMahon, F.R.S., F.G.S. 



introduction. 



The peridotites and serpentines described in the following pages 

 are found intrusive in the tertiary volcanic series of Ladakh, North- 

 Western Himalaya. 



Some of the specimens were collected by the late Dr. Ferdinand 

 Stoliczka, and the rest by Messrs. R. Lydekker, F.R.S., F.G.S. ; 

 R. D. Oldham, A.R.S.M., F.G.S., and T. D. La Touche, and this collec- 

 tion of rocks has been lent to me for description by the Geological 

 Survey of India. 



Dr. Stoliczka's reference to the rocks of the Puga valley will 

 be found at p. 128, Vol. V, Memoirs, Geol. Surv. Ind. " These 

 quartzose schists/' Dr. Stoliczka writes, "form both sides of the 

 Puga valley and become towards the epidote rocks somewhat 

 chloritic, and even garnetiferous. They dip against these epidote 

 rocks where they are visible in the eastern part of the Puga valley. 



The axis of Cunningham's Trans-Himalaya or Tsomoriri range 

 consists here of a series of epidote^ diallage and serpentine rocks. 



( 1 ) 



