58 lieconls uf the Geological Surnei/ of ladia. [vOL. Xli. 
sible for a Himalayan traveller, witb a long and toilsome march before him, to 
crack every piece of rock he sees, and scrutinize it minutely; and when rocks on 
their weathered surface give no outward indication of a change, it would be quite 
possible, I imagine, to miss the border line between slaty micaceous or slaty 
silicious schists on the one side, and micaceous or silicious slates on the other. 
The difficulty is increased not only by the fact that some metamorphic rocks in 
this area closely resemble in external appearance the sandstones and slates of 
the palasozoic series in contact with them, but also from the circumstance that 
both series have been alike affected by comparatively I'ecent disturbances. 
I have no note of any granite veins, and I feel sure I did not see any in the 
schists at Lepi. I see no reason to suppose that the intrusion of the Gongra 
gi'anite (which I believe to be albite granite) occurred at a later period than 
the albite granite of other sections; and I do not, therefore, think that the 
metamorphism of the schists at Lepi can be explained by referiing it to the rise 
of the granite. 
A.t the top of the Ruhang pas.s the dip changes to south-south-west, and the 
angle of dip is high all the way down to Scingnam (elevation 9,620 feet). The 
rocks resemble the slates and fine .sandstones of the Simla slate series. 
At Sungnam, the slates, which are here neai'ly perjiendicular (dip extremely 
high to west-by-south), are of a light grey color ; but on the way up the Hangrang 
pass they get darker in color, and become like the Simla slate beds that so much 
resemble some of the nummulitic clays. At an elevation of 10,160 feet, the 
northerly dip is recovered by a sharp and fractured anticlinal, along which some 
of the beds above, dipping uoiih-east, seem to have been pushed over the beds on 
the south-west side of the anticlinal. 
At an elevation of 11,050 feet, the slates teiuninate suddenly, their junction 
with the rocks above them being masked by a side stream, running down from 
the top of the Hangrang pass. On the other side of this stream, pink lime¬ 
stone appears, in beds of from 1| to 2| feet in thickness. There are probably 
from 300 to 400 feet of them. 
When first seen the pink limestones apparently dip north-north-west, biit 
this rapidly subsides into a north-east-by-north dip. These beds are overlaid 
conformably by pui-ple calcareous indurated clays that break under the hammer 
into lumps, and not into .slaty slices. Over the.se is a .small outcrop of a slate 
with a dark streak, which is overlaid, at an elevation of 12,000 feet, by a thin 
bed of dark-blue limestone. Then follow, in the ascending order, dark slates 
that break into acicular fragments. They reminded me so much of the 
argillaceou.s beds exposed on the eastern side of the Krol mountain^ that it 
needed the test of acid to satisfy me that they wei-e not calcareous. At an 
elevation of 12,300 feet these slates give place to dark-blue compact limestones, 
for the most part in beds of half a foot to two feet in thickness, and they continue 
up to the top of the pas.s (elevation 14,630 feet). A bed of greenstone occurs 
in them. 
1 Mem. G. S. I., Vol. Ill, pt. 2, p. 21. 
