16 
SECOND YABKAND MISSION. 
syenitic ones. As already mentioned, the rock often has a porphyritic structure, and the 
felspar becomes pink, instead of white,—as, for instance, on the top of the Khardung pass and 
on the southern slope of the Chang-la, where large fragments are often met without the 
slightest trace of hornblende. To the north of the last-mentioned pass the syenitic gneiss 
gradually passes into thick beds of syenite-schist, and this again into chloritic schist, by the 
hornblende becoming replaced by chlorite, while the other mineral constituents are gradually 
almost entirely suppressed. The syenitic and chloritic beds alternate with quartzose schists 
of great thickness. The schistose series of rocks continues from north of the Chang-la to 
the western end of the Pankong lake, and northwards to the Lankar-la, generally called 
the Marsemik pass. On the western route Dr. Bellew met similar rocks north of the 
Khardung pass at the Tillage Khardung, and traced them northwards across the Shayok 
up the Nubra valley to near the foot of the Sasser pass. 
Intimately connected with the metamorphic schistose series just noticed is a greenish 
chloritic, partly thin-bedded, partly more massive rock, which very closely resembles a similar 
rock found about Srinagar. Only in this case certain layers, or portions of it, become often 
distinctly or even coarsely crystalline, sometimes containing bronzite sparingly disseminated, 
and thus passing into diallage. This chloritic rock forms the greater part of the left side of the 
Changchenmo valley, and also occurs south of the Sasser pass. I think we have to look upon 
this whole series of schistose and chloritic rocks as the representatives of the Silurian formation. 
After crossing the Changchenmo valley to Gogra, we met with a different set of rocks. 
They are dark, often quite black, shales, alternating with sandstones. Many beds of the 
latter have a comparatively recent aspect, and are rather micaceous, without the least 
metamorphic structure, while the shales accompanying them very often exhibit a silky, sub- 
metamorphic appearance on the planes of fracture. I observed occasionally traces of fucoicls 
and other plants in these shales, hut no animal fossils. On the Changchenmo route these 
shaly rocks form the ridge of the Chang-lung pass, as well as the whole of the western 
portion of the Lingzi-thung; and they are met again after crossing these high plains and 
entering the Karakash valley, as far as Shinglung (or Dunglung). On the Karakoram route 
Dr. Bellew brought specimens of similar rocks from the Mastagh (Karakoram) range itself. 
There can he hut little doubt,—judging from similar rocks which I saw in Spiti, and from 
their geological relation to certain limestones, of which I shall presently speak,—that we 
have in the shaly series the carboniferous formation represented. 
In many localities along the right hank of the Changchenmo river, then at the hot 
springs north of Gogra, and on the southern side of the Chang-lung pass, we find the carbonb 
Gogra, Hot springs. 
Section of rocJcs at the hot springs of Gogra. 
ferous beds overlain by triassic limestone , which often has the characteristic semi-oolitic 
structure of the Krol limestone, south of Simla. At Gogra and several other places dolomh 
