SILURIAN SYSTEM. 
23 
Near Prdd5, in tlie upper Pin valley, the whole of the silurian system 
is enclosed in a great synclinal lying on the ui)per cambrian slates, and 
cut off on either side by faults. On the opposite nde of the river, be- 
hind Baldar, this synclinal caps the ridge to the north of the Bhabeh 
Pass and runs on to the south-east into the valley of the Teti river in 
Bashahr. The conglomerate forms a very distinct and conspicuous 
dark band below the red quartzite. 
In the valley of the Chokdinjan stream in Bashahr, at about a mile 
above its junction with the Thanam river, the conglomerate, which lies 
on the lower beds of the trilobite series, forms a single band 40 feet 
thick, composed of boulders of slate and quartzite in a red, gritty matrix 
and passes up gradually through pebble beds and grits into the overly- 
ing red quartzite. 
The red quartzite calls for little notice ; except in regard to colour, 
its characters are constant throughout Spiti and 
Red quartzite. , , » . , » . , . 
Bashahr. A typical section is seen at about one 
mile south-west of Muth, where the rock is a dark pinkish-red — at 
times carmine — quartzite, usually gritty and occurring in beds of 
about 2 feet in thickness. With it are interbedded thin layers of 
a lighter coloured shale. The thickness of the whole mass is about 
1,500 feet. No trace of fossils was found anywhere in the quartzite or 
in the shales. In disturbed areas where the rocks have suffered from 
dynamo-metamorphism, the quartzite has undergone little alteration 
beyond a loss of colour. This is especially noticeable near Prada in 
the Pin valley, below Pamachaung, on the path from Rupa to the 
Manirang Pass, at Hango, and on the south side of the Hangrang 
Pass; in the two last-named localities the rock is pale pink, at 
times almost white, and in the latter case might easily be mistaken 
for the " Muth quartzite," which, however, belongs to a higher 
horizon. 
Towards the top, the quartzite becomes more thinly bedded and is 
gradually replaced by flaggy beds and siliceous shales, which pass up 
into a system of shale, marl and limestone which constitutes the middle 
division of Stoliczka's " Muth series " ; he describes it as a system of 
( 23 ) 
