234 
lieconh of the Geoliyi.cal Survey of India. 
[voL. xin. 
are numerous ‘ erratics,’ and I determined to trace them to their source, though 
I hardly anticii^ated so clear and decisive a result as rewarded my efforts. 
The valley of the Nainsukh or Kauhar river, draining the Kaghan valley on 
the north, is very narrow wuth a very great fall, and hounded on either side by 
ranges of hills with peaks from 8,000 to 15,000 feet or more. On nearing Garhi 
Habihulla from Mansahi-a enormous ‘ fans’ are seen descending from the range 
across the river (to the east) to the stream. On the west hank, however, the 
road from Garhi to Kaghan lies along the bed of the stream, and is skirted 
in many places for miles by a steep cliff of old river gravels, through which the 
brawling river has cut its present bed. This cliff varies from 80 to 100 feet 
or more in height, and the thickness of the gravels, or old alluvial deposits, of the 
Kanhar river may be 160 or 200 feet or more, which is neither easy on a 
curaory visit, nor material to determine. In this cliff every pebble is clearly 
exposed, and the striking fact was soon established beyond all question, that no 
‘ erratics’ e.xisted in this dcpo.sit from top to bottom. Yet, they were plentiful 
enough in the bed of the stream, from 15 to 60 feet or more in girth. 
Whore, then, did they come from ? 
About Garhi, the gravel of this old alluvium is not very coarse, that is, it is 
a gravel in which boulders of one foot in diameter are rare and conspicuous for 
their size, conti-asted with the bulk of the materials around them. Ascending 
the stream, however, the deposit increases in coarseness gradually, till near 
Byssia, boulders of from 1 to 10 feet in diameter have become pretty 
numerous, but no erratics or boulders of a larger size. The section of the 
deposit is clear, and the fact indisputable. A mile below Byssia, the road winds 
round an almost overhanging cliff of these gravels. Here an occasional boulder 
of 3 feet in diameter may be detected, though such are rare; whilst in the 
river bed beneath huge ‘ erratics ’ are plentiful, and a little way higher uj) 
numbers occur, two of which were over 70 feet in girth. The largest ‘ erratics ’ 
in the river bed are of the usual Hazara gneiss ; whereas gneiss is not prominent 
in the terrace gravels, and only in small boulders, the larger blocks in these bods 
consisting of limestone, hard schists, or trap rocks. It, therefore, became perfectly 
clear, even before reaching Byssia, that no erratics W'ere being brought down 
by any agency during the period these old gi-avels were being laid down. 
This deduction, which is beyond challenge, is the key to the glacial pheno¬ 
mena of the ontu’O sub-Himalayan region. 
Byssia is built on a low terrace of coarse gravel, as described above ; but it is 
not more than a third as high as the terrace near Garhi. On the opposite bank 
of the river, however, a part of the old alluvial terrace is scon of the usual 
height, so it is clear that some agenoy has operated to reduce the height of that 
portion on which Byssia stands. Close to the village some scattered erratics 
are seen, and at the village graves, a lino of erratics commences and extends 
thence right up the valley. The annexed sketch (see map) will illustrate the 
general feature of the ground. The emxtic blocks are of the ordinary character 
of the Hazara gneiss erratics ; and it would seem to bo the continuation of this 
line, enguljxhed in the river, which I noticed above as yielding blocks 70 feet 
in girth. 
