492 THE CENTRAL ASIAN DESERTS, SAND-DUNES, AND SANDS.
ground. The gently undulating surface grew level again or was slightly lumpy schor, somewhat moist on the top, with rapidly thinning kamisch. Then followed a belt of rounded tamarisk-mounds, I to 3 m. high, carrying dried up tamarisks. Almost all the kamisch we saw there was dead, and occurred in small isolated patches. Afterwards the mounds grew more numerous, and some of the tamarisks on them were still living. There were also a couple of dunes of hard, coarse sand, not more than 3 m. high, but despite this fact they appeared to be stationary. They extended from north-east to south-west. North of them was a shallow, indistinctly marked bed, running from east to west; it was in fact partly obliterated, and probably owed its origin to some local, but exceptionally violent, shower of rain that fell in the desert. North of this again were a number of tamarisks, mostly living, and standing partly on the level ground, partly on small mounds. The surface there consisted of a thin, loose crust of grey schor, resting upon sand, and so brittle that it crumbled to pieces when trodden upon. Belts of tamarisks and kamisch extended westwards as far as the sandy desert, a distance of about 7 km.
Fig. 220
Shortly after that we reached the sharply defined edge of this area of vegetation. It was like the shore of a lake, and beyond only a few solitary tamarisks, or small groups of tamarisks, dotted the surface like islands and holms. The ground too was very hard, and was covered with fine gravel, and so it continued for as far as we could see towards the north-east. Embedded in this sterile saj lay a large island or oasis of kamisch and tamarisks, the gravelly soil being raised above it all round like a bank; and in the middle of the oasis was a still smaller depression, showing a level, white schor surface. To the east we perceived two or three solitary table-like elevations of clay. On the whole, judging from such tiny water-channels as there were, the surface appeared to slope towards the north-west. One of my men, who reconnoitred the country to the west, reported, that immediately before reaching the sandy desert he came to a marshy region, into which a few small watercourses gathered, and which some time or other must have formed a small temporary lake or marsh.
Fig. 22I. VERTICAL SECTION OF A LITTLE KAMISCH ISLAND IN THE DESERT.
On the other side of the oasis the hard gravelly soil again made its appearance. We also passed on our left yet another similar small oasis, to the south of which, and stretching westwards, was a narrow strip of white level schor. The western
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