LADAKH, NORTH-WESTERN HIMALAYA. 3U 



of amphibole. Isotropic structureless mineral matter often inter- 

 venes between the serpentine proper and the pyroxene and bastite. 

 I think it is identical with that stopping the canals in the pyroxene 

 and is a variety of serpentine. 



No. Q4 — 213. Altered Peridotite (Lherzolite) from the Markha river, 

 Ladakh; collected by the late Dr. Ferdinand Stoliczka; Sp. G. 3*155. 



This specimen has already been described by me in the Records, 

 Geol. Surv. Ind., Vol. XIX, p. 117, and I quoted in that paper 

 Dr. Stoliczka's and Mr. Lydekker's references to it in the Mem., 

 Geol. Surv. Ind., Vols. V, p. 343, and XXII, p. 107, from which it 

 appears that it is intrusive in rocks of eocene age. 



This peridotite is composed of olivine, enstatite, augite, picotite 

 and magnetite. Olivine is very abundant, the major part of the rock 

 consisting of it. Fine aqueous canals traverse it in all directions, but 

 beyond the formation of these channels serpentinisation has made 

 no progress and has left the body of the mineral quite fresh. The 

 augite and enstatite, on the other hand, exhibit the commencement 

 of the first stages of conversion into diallage and bastite. 



Cracks in the rock are stopped with a colourless fibrous ser- 

 pentine. 



No. Q4 — 214. Altered Peridotite, from Puga valley, Ladakh ; collected by 

 the late Dr. Ferdinand Stoliczka; Sp. G. 3*039. 



This rock consists of serpentine and diallage with a considerable 

 amount of secondary magnetite. The serpentine and diallage pre- 

 sent their usual characters and do not need detailed description. 

 Serpentine is the most abundant mineral, but diallage does not fall 

 very far behind it. 



No. 04—21$, Partially altered Peridotite (saxonite) from the Puga valley, 

 Ladakh ; collected by the late Dr. Ferdinand Stoliczka ; Sp. G. 2-857. 



This rock was described by me in the Records, Geol. Surv. Ind., 



Vol. XIX, p. 115. It is composed of olivine, serpentine, enstatite, 



pyroxene and picotite. 



( 9 ) 



