TO THE LAKOR-TSO. ANCIENT BEACH-LINES. 151
On 18th October we made an interesting journey of 20 km., down into the depression of which I have spoken, and which contained a lake. The brook that flowed past our camp soon died away in its channel, its little rivulet not being able to get down to the principal drainage-artery of the latitudinal valley. We forded it, and having the valley diagonally towards the west-south-west, kept along the foot of the southern range, the distance across to the reddish range on the opposite or north side of the valley being rather great. In front of it stand at intervals smaller foot-hills and heights, of a more rounded external appearance. At the beginning of our day's march we encountered corresponding hills at the base of the southern range. From this range too there issue a number of transverse glens, with deep-cut, difficult ravines. It would have been far more convenient for us to have travelled towards the lake along the middle of the valley; instead of that we followed the advice of our Tibetan guides, who induced us to incline to the south-west towards the outlet of a big transverse glen; it led, they asserted, to an easy pass, which we must cross over in order to get water and grazing at night. A preliminary examination convinced me however, that this road was impracticable for the caravan. The ascent to the top of the pass was through a narrow gorge filled with gravel and stones, with rugged spurs on both sides, but the actual pass itself was easy enough. This road would indeed have been a good deal shorter; but the longer route which we selected was far more convenient, and, what was more important, far more instructive. We were now so high up on the detritus slope of the range, that we could make straight for the lake, though this necessitated our crossing over an endless number of disagreeable, deeply incised eroded channels of the same kind as the fschaas of Kirk-saj in East Turkestan. The sides of some of these are so steep that we had to cut steps with our spades before we could get the camels over. Here again it would have been better to have kept to the middle of the valley, where the surface adjacent to its principal drainage-artery was level and made easy going. But after we had crossed over a minor offshoot of the range by means of a small convenient bel, the country became more favourable.
Thence an unwonted view disclosed itself. We again saw the lake to the west-south-west. From the bel runs in a regularly curved arc a high, conspicuously modelled shore-rampart, north, north-west, west-north-west, and west, until it is interrupted by minor bluffs on the northern shore of the lake. This natural circular rampart, the top of which would be about 5o m. above the existing level of the lake, is the highest and oldest indication in the bottom of the latitudinal valley that points to the lake-basin having formerly covered a more extensive area. The rampart is broken in the middle by the main stream of the valley. As we travelled on farther towards the south-west, we encountered seven similar shore-ramparts; but as they are smaller than the first one, although at the same time clearly and energetically constructed, we may conclude, that the lake maintained for a relatively long time the position and area indicated by the highest rampart, thus affording the wave-action a better opportunity to shape it. Add to this, that each of the lower ramparts points to a successively smaller lake area and an increasing diminution in the power of the waves, under the influence of the west wind, to build up
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