THE YESHIL-KÜL. 5I
abundant. We had seen two or three yaks above Camp XVI, being the first in this part of Tibet.
To the east a rounded hill rose between the low ranges north and south of the valley, and it seemed difficult to decide whether the next transverse saddle was north or south of it. We tried the southern side and soon reached the threshold at an elevation of 5,301 m. Lake Lighten now was hidden, but to the east we had a new considerable self-contained basin or isolated drainage area surrounded on all sides by moderate mountains. This basin appeared to be very flat. In its lowest part was Yeshil-köl, with very flat shores all around, except in the north, where the mountains reached near the lake. These flat shore plains especially to the south, were shining white with salt, and even at a distance, we got a strong impression that the lake was drying up. From the morphology of the basin it was easy to see that this lake must be shallow. To the east far beyond the lake a great mountain with eternal snow was seen, forming some flat cupolas. To the south were moderate violet mountains. Going down E. S. E. from the pass we had red, low, steep hills to our right. The rock is reddish brown conglomerate. To the left were low hills. In the middle of the descending valley was an erosion bed which lower down contained water from a tributary from the northern side. At Camp XVIII good grass, yapkak, and yak dung were abundant.
From this place we were only i o km. from Camp XIX on the west shore of Yeshil-köl. The direction is east and E. S. E. Camp XIX lies at 4,955 m. or 2 13 n1. below Camp XVIII; the fall of the ground is, therefore, as i : 47.
The ground is undulating due to small, flat mounds of grass; between them several small furrows go S. E. to the principal erosion bed from the threshold. To the S. S. E. beyond the violet mountains, there is a snow-covered range with high peaks. The lake is of a brilliant blue colour. From a distance it is easy to see the concentric desiccation lines at its southern side, where two or three isolated pools have the same bright colour as the lake. A little knoll at the side of our course consisted of black, dense basalt. To the right at some distance was a small isolated hill with well developed beach-lines at its N. E. base. Near the point where the chief erosion bed receives a tributary from the north the camp was pitched. The beds are comparatively energetically cut down in the ground between grass-grown mounds. At one place here living rock cropped out and consisted of reddish grey sandstone. The water was brackish, though drinkable. The camp was located about 1 km. from the shore and some i o or 15 ni. above the lake which has an elevation of 4,945 m. Several beach-lines are crossed between the camp and the lake. The water of the latter is very salt but perfectly clear. The 1 m. line ran at about i oo m. from shore ; at 600 m. from shore the depth was 4.6 m. At 5 o'clock p. m. the lake had a temperature of 8.2°.
IIIFカラー高解像度
