THE BAJIRS. 323
sand in the middle of a bajir. But, as I have already stated above, the origin of the sandy island in the Ullugh-köl is to be explained in a different way.
December 24th. In the southern part of bajir No. i 3 there was a projection or spur of the eastern dune-wall, and immediately opposite to it on the west side the beginning of a fresh threshold. Here, strange to say, some small dunes of irregular shape had formed near the eastern edge of the bajir; otherwise these eastern parts are just those which, enjoying protection against the wind, are generally free from sand. The exceptions to the rule have evidently been formed by the north-north-east and south-south-west winds, the manner of their origination being shown in fig. 265.
Bajir No. 14 was almost entirely sanded up, the only places free from sand being two or three small patches. This was in part due to its own small size, which had caused it to be encroached upon by the two sandy thresholds which shut it in on both north and south, and in part to the pronounced festooning of its eastern dune-wall, the cusp which came nearest to the northern threshold being especially prominent. Bajir No. i 5, in spite of the great number of small dunes in its northern half, proved a good friend to us. These dunes were of two different types — some the ordinary ridges running from north-east to south-west, others ideal crescents in
outline, with both their horns pointing towards the south-west. As a rule, the small dunes in the bajirs originate, as for instance in Nos. i i and i 2, only on the west side, where the wind has freer play than under the steep leeward flanks on the east. Towards the south end of bajir No. 15 there were other table-like jardangs of clay, similar in appearance to those recently described, and in addition to them step-like terraces of clay. All these are of course the surviving fragments of a once extensive formation, which has been cut down and planed away by corrasion. On the whole these fragmentary survivals are very rare, although there are no doubt numbers of them buried under the sand. They have precisely the same appearance as the clay scarpments or edges which I encountered in the Takla-makan Desert. Possibly it is a pure chance, that they are almost entirely confined to the southern parts of the depressions, whilst, with one exception, they are entirely absent in the northern parts. But very likely this, again, may be a result of corrasion, for if there is any part of these bajirs which is accessible to the north-east and north-north-east winds, it is their southern end. In that quarter the winds' action is more of an excavating character; that is, it cuts in deeper and so causes the harder clay-bed, which in other parts of
IIIFカラー高解像度
