GEOLOGY. 
15 
The 
PART II. 
hill ranges between the Indus Valley in Ladak and Shah-i-dula on the 
ERONTIER OE YARKAND TERRITORY. 
[ This section is copied, with a few verbal alterations, from the Records of the Geological Survey of India, V°l. VII, p. 12.] 
1 hh following brief notes on tlie general geological structure of tlie bill ranges alluded 
of t 16 ^ asec ^ u P on observations made on a tour from Leb, via Cbangcbenmo, tlie high plains 
nigzi-tliung, Karat&gh, Aktagh to Shah-i-dula, and upon corresponding observations 
niacle by Dr. H. W. Bellow, accompanying His Excellency Mr. Eorsyth’s camp along the 
Karakoram route to this place. 
Before proceeding with my account, I will only notice that our journey from Leh (or 
‘Wak) -was undertaken during the second half of September and in October, and that we 
°Hnd the greater portion of the country north of the Changchcnmo valley covered with 
j'J'Q'v the greatest obstacle a geologist can meet on his survey. While on our journey the 
lerm °nieter very rarely rose diu'ing the day above the freezing point, and hammer operations 
jVie not easily carried out. At night the thermometer sank, as a rule, to zero, or even to 8° 
,?A )W zero, in our tents, and to 26° below zero in the open air. Adding to this the natural 
]-<> ICll ^ es the ground we had to pass through, it was occasionally not an easy matter to 
u P the health up to the required standard of working power, 
j ■^ ear Leh, and for a few miles east and west of it, the Indus flows on the boundary 
ween crystalline rocks on the north and eocene rocks on the south. The latter consist 
*1 y .°^ g re y an d reddish sandstones and shales, and more or less coarse conglomerates, 
tron lrUn ^ au occasional Nummulite and casts of Pelecypoda. These tertiary rocks extend 
eastward south of the Pankong lake, following the Indus either along one or both 
t' • / S ^ le river, as far west as Kargil, where they terminate with a kind of brackish and 
s 1_ Water deposit, containing Melanice. 
. e _ ar ly the entire ridge north of the Indus, separating this river from the Shayok, and 
the lnU ' n ® * n a south-easterly direction to the mouth of the Hanle river (and crossing here 
(l ',? ^ U( ^ Us ’ extending to my knowledge as far as Demchok), consists of syenitic gneiss, an 
emel y variable rock as regards its mineralogical composition. The typical rock is a 
, era mly fine-grained syenite, crossed by veins which are somewhat richer in hornblende, 
+ 6 °riier portions contain a large quantity of schorl. Both about Leh and further 
Th Wara ex tensive beds of dark, almost black, fine-grained syenite occur in the other rock. 
le felspar often almost entirely disappears from this fine-grained variety, and quartz remains 
y sparingly disseminated, so that gradually the rock passes into a kornblendic schist ; and 
en s °horl replaces hornblende, the same rock changes into layers which are almost entirely 
"Hposed of needles of schorl. Again, the syenite loses in places all its hornblende, the 
ant a ^ S ^ s P ar increase in size, biotite (or sometimes chlorite) becomes more or less abund- 
. j a,l( i with the addition of quartz we have before us a typical gneiss (or protogine gneiss), 
1 out being able to draw a boundary between it and typical syenite. However, the gneissic 
ions, many of which appear to be regularly bedded, are decidedly subordinate to the 
