23 HAYDEN : GEOLOGY OF SPITl, 
be expected, the conglomerate series is itself somewhat variable, both in 
character and thickness. This will be seen most readily from adescrip- 
Conglomerate in Pin ^^^^ ^ the more important sections. 
valley. lha.t at Shian has already been described ; but 
others are seen in the high range to the south-west of Muth, near Baldar, 
in the upper Pin valley, in the valley of the Parahio and in the Thanam 
valley in Bashahr. Numerous other exposures occur, chiefly near the 
heads of the rivers flowing into the Spiti river from the south-west, 
but those enumerated above will be sufficient to indicate the salient 
characters of the series. 
In the Parahio valley, the two sections, from which the Cambrian 
, „ rocks have been described, also afford typical 
In Paranio valley. 
exposures of the lower silurian beds. In the 
hills on the right bank of the river, the sequence is as follows (in 
descending order) : — 
4. Pinkish-red quartzite, passing down into red- 
dish grit about 1,500 feet. 
3. Conglomerate, composed of large pebbles of 
quartzite and quartz, in a fine, gritty matrix . ,, 50 „ 
2. Hard, gritty sandstones, with pale yellowish- 
grey and white quartzite ... . „ 20 „ 
I. Conglomerate, composed of pebbles of quartzite, 
with some larger boulders of upper Cambrian 
dolomite . . . . . . • ,. 30 „ 
The two bands of conglomerate differ slightly from one another, for 
the lower bed contains, in addition to pebbles of quartzite, most of which 
range from three to six inches in diameter, larger pebbles of the under- 
lying dolomite, not, however, in any great quantity ; the upper bed 
appears to contain only quartzite and quartz, and passes through grits 
into the red quartzite. 
In this particular section the two conglomerates are separated by a 
band of finer material, which is of very variable thickness, ranging from 
about 20 feet to a mere thread, and sometimes dying out altogether : 
this is the case in the section on the left bank of the Parahio (PI. VII), 
where, however, the other characters are the same as those in the sec- 
tion just described. 
( 22 ) 
