GEOLOGY. 
21 
PAET III. 
Erom Shah-i-dtjla to Yarkand and Kashgkar. 
[ Prom Records of the Geological Survey of India, Vol. VII, p. 49; and Quart. Jour. Geol. Soc., 1874, Vol. XXX, p. 571. ] 
In a former communication I had already occasion to notice, that the rocks composing 
the Kuenluen range near Shah-i-dula chiefly consist of syenitic gneiss, often interbedded, and 
alternating with various metamorphic and quartzose schists. Similar rocks continue the 
whole way down the Karakash river for about 24 miles. After this the road follows, 
in a somewhat north-westerly direction, a small stream leading to the Sanju (or Grim) pass. 
Here the rocks are chiefly true mica schist, in places full of garnets. Near the summit, and 
on the pass itself, chloritic and quartzose schists prevail, in which veins of pale-green jade 
occur, numerous blocks containing this mineral having been observed near the top of the pass. 
All the strata are very highly inclined, often vertical, the slopes of the hills, and in fact of 
the entire range, being on that account rather precipitous, and the crests of the ridges them¬ 
selves very narrow. 
Sanja pass. 
i. Metamorphic rocks. ta. Submetamorphic schists. 2. Slates. 3. Sandstones and conglomerates. 
Section from the Sanju Pass to Kiwaz. 
To the north of the Sanju pass we again meet with metamorphic, mostly chloritic schists, 
until we approach the camping place Tam, where distinctly bedded sedimentary rocks cap 
the hills of both sides of the valley. They are dark, almost black, silky slates, resting 
unconformahly on the schists, and are overlain by a grey, partly quartzitic sandstone, passing 
into conglomerate. The last rock contains particles of the black slates, and is, therefore, 
clearly of younger age. Some of the conglomeratic beds have a remarkably recent aspect, 
but others are almost metamorphic. In none of the groups, the slates or sandstones or 
conglomerates, have any fossils been observed ; but they appear to belong to some palaeozoic 
formation. They all dip at from 40° to 50° towards north-east, extending for about 1J 
miles down the Sanju valley. Here they are suddenly cut off by metamorphic schists, 
but the exact place of contact on the slopes of the hills is entirely concealed by debris. The 
schists are only in one or two places interrupted by massive beds of a beautiful porphyritic 
gneiss, containing splendid crystals of orthoclase and biotite; they continue for about 18 
miles to the camp Kiwaz. On the road, which often passes through very narrow portions 
of the valley, we frequently met with old river deposits, consisting of beds of gravel and very 
fine clay, which is easily carried off by only a moderate breeze, and fills the atmosphere with 
clouds of dust. These old river deposits reach in many places up to about 150 feet 
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