Southern Tibet : vol.7 / 717 ページ（白黒高解像度画像）

0717	Southern Tibet : vol.7
南チベット : vol.7

0717

Southern Tibet : vol.7

南チベット : vol.7

for one moment attribute to the existing little brook, even making allowance for its
summer highwater. It is clearly from the same period also that the side-terraces
date; and it is noteworthy that they have been built up with especial distinctness
at the elbow on the right side of the valley, where the full force of the current
spends itself. There too the rocky walls are precipitous, whereas on the opposite
or left side they slope gently down to the bottom of the valley. From that point
the terraces continue all the way down to Drugub, growing larger and more distinctly
defined as they proceed, so much so indeed that they not seldom constitute the
peculiar and salient feature of the landscape.¹

Just a little above the point where the Drugub river joins the Shayok, there
is at the right side of the latter a strikingly developed erosion terrace or rather
two terraces, of which I have two photos on p. 398 of Vol IV, Scientific Results,
and a third opposite p. 400.

It is not only in the brook of Drugub, in the Shayok and Chang-chenmo and
other tributaries in this region that gigantic remains have been left from a time
when enormous quantities of water flowed down through these valleys. Such monu-
ments, though on a smaller scale, are also to be found in valleys through which flow
brooks which are affluents to the Tso-nyak, and thus ultimately to Panggong-tso.

My Camp CXXXIII (1901) is at a distance of 70 km. east of Tso-nyak.² Half
a day's march east of that Camp there were unmistakable traces of an old dried-up
lake in the great latitudinal valley. South and S. E. of the Camp was a well-defined
terrace, 4 or 5 m. high (Cf. photo p. 254, Vol. IV, Scient. Results). The altitude
of the camp was 4597 m., while the next camp to the west, Camp CXXXIV, was
at 4587 m. In travelling here I wrote: The whole of the lower part of the slope looks
as if it had been shorn away. It is not, however, continuous, but is sometimes inter-
rupted by recently formed gravelly screes. Yet even the bigger screes that block
the outlets of the transverse glens have been cut through in a similar manner, proving
that the sedimentary matter which has been washed down across the scree since the
shearing took place, has not been sufficient to cover over and obliterate the old
terrace, which was formed at a time when the climate was wetter than it is now.
During the succeeding day's march the shearing was even more pronounced. This
is, I have no doubt, the last trace of the effluent from the lake, which, as a consequence
of the configuration of the ground, crept close in to the southern base of the range,
where its erosive activity gave rise to the terrace in question, and at an earlier epoch,
where there was a copious inflow into the lake, the erosive energy of its effluent

国立情報学研究所 - ディジタル・シルクロード・プロジェクト
『東洋文庫所蔵』貴重書デジタルアーカイブ

引用情報

OCR読み取り結果

国立情報学研究所 - ディジタル・シルクロード・プロジェクト 『東洋文庫所蔵』貴重書デジタルアーカイブ

引用情報

OCR読み取り結果

国立情報学研究所 - ディジタル・シルクロード・プロジェクト
『東洋文庫所蔵』貴重書デジタルアーカイブ