172 MY FIRST JOURNEY IN NORTH-EASTERN TIBET.
in the summer; for it was still moist and marshy to a great distance from the stream and the ground consisted of a deceitful yellow clayey mire. The country here was remarkably flat, and in crossing over this broad latitudinal valley in a diagonal direction, as we were doing, it was impossible to detect either slope or undulations. The shape of the valley bottom explains the absence of erosion-terraces beside the
river. In the height of summer, when it would be utterly impossible to cross this valley, its lower section is in great part inundated; perhaps the western shore of the lake reaches then all the way to the vicinity of Camp LXV. The shape of the basin throughout points to the lake being unusually shallow, so that but a slight rise of its surface must be followed by an imcomparable enlargement of its area. It is owing to these facts, that the river spreads out over a great part of the valley and then in the autumn withdraws into the shallow bed in which we found it, that it
Fig. 134. SOME VIEWS OF THE RIVER OF ATSCHIK-KÖL.
IIIFカラー高解像度
