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

296

side joins the Pu-chu, and Bug-nakta coming from the right, joins the. Serma-chu. The former comes from a black mountain, Ürok; the mountains opposite it are called

Sokba; Sokchung-le is a place in the valley below them; Pendo and Okbö-kaktsang

are small valleys from the right. The country is open and flat, the surrounding mountains relatively low; only to the S.W. are there comparatively high snow-

covered mountains, from which descend two valleys: Tsa-tunglung and Nakdong, the latter from a peak called Gurkar. Tabuk is a small valley from the same direction. All these valleys originate from one and the same mountain-group covered with snow, although not eternal. Camp 158 at Serme-lartsa is at 5 3 1 o m.

On the eastern side of Serma-chu is a low ridge, which the road crosses in Serma-la, and then goes down to another valley, Serma-leting, which probably

reaches the lake south of Serma-chu. A mountain ridge on the right side of Serma-

leting is called Tengri-gok. Leting-tavuk is a tributary from the left or west; a valley from the east is called Chakta. The detritus consists of red porphyry. The

ground rises slowly up to the pass Sao-lungring or Lungring-lachen, 5 387 m high,

which is secondary, as the water from both sides goes down to Raga-tsangpo. South of it is the valley of Lungring, which comes from comparatively high snow mountains

in the N.W. Here the detritus is grey granite, the living rock conglomerate and dark limestone. The Lungring is a direct tributary to the Raga-tsangpo; to the east it is bounded by a well-defined ramification, in which there is a curious depression or saddle, so deep as to permit a view over to the eastern neighbouring valley and to the ramifications east of the same.

Talung is a right tributary to the Lungring. The road crosses it near its junction and then goes over a ridge to another valley, Tajep. All these small val-

leys are tributaries to the Raga-tsangpo. The Tajep is broad and open near the

road, but then goes through a narrow passage between steep mountains to the Raga. The road then goes up its right tributary, Puga, to a small threshold, 5 384 m high.

After another little valley and threshold we reach the valley Tsarok, where the living rock is dark limestone. A little below a widening called Tsarok-pagla, the Tsarok valley joins the Raga-tsangpo at a height of 4 861 m, showing a fall of 848 m on a distance of 18o km down to the junction with the Tsangpo.

The Shuru-tso is at 4 725 m; the Raga-tsangpo, Camp 159, at 4 86I m. Between both are two great ranges, the northern, Pabla, with the continental water-

parting and crossed in Angden-la, 5 643 m high; the southern, the probable western

continuation of the Nien-chen-tang-la, in Sao-lungring at 5 387 m. From the water-parting there is a fall of 918 m to the Shuru-tso on a line of 31,5 km as the crow

flies; to the Raga a fall of 782 m in 48 km. Amchok-tso is at 4 86o m. These values will give an idea of the general flatness of the system, and also of the existence of two very well defined mountain ranges between the Shuru-tso and Ragatsangpo. There may, perhaps, exist some smaller ranges between the two principal ones.

THE THIRD CROSSING.