42 EXPLORATIONS IN TURKESTAN.
narrow valley floor of the present stream. Evidence
in a ateresection. of milaWterracing indica-
tions southwest of Askhabad will be given
of deltas or other shoreline features here—nothing but the results of forward-washing stream action. It may be that the chief evidence for drawing the Quaternary Caspian shoreline near KiziA the ulountain base, with the level of the sea
l the agreement
altitude of the plain, a few miles as determined by recognizable shorelines elsewhere. In that case its location can, of course, be only approximate.
At Bakharden, between Kizil-Arvat and Askhabad, we rode out to the dunes along the course of a small stream, whose occasional floods keep a graded passage open among the sands for several miles from the mountains. The surface of the
Fig. 22.—Dissected Terraces at the base of the Kopet Dagh, south of the Kizil-Arvat, looking southwest. The horizontal limestones of the Mountain on the left are suddenly bent down so as to pass under the clays of the Terraces in the middle distance.
sands was irregular at first (fig. 23); then the dunes began in moderate relief, seldom exceeding 15 feet in height. The scarps of the crescentic dunes or barkhans (fig. 24) were to the west, as if the sands had been drifted by easterly winds. The sand bore a scanty growth of grass, except on the freshest dunes. Between the dunes and the mountains there was no sign of shore-terrace or delta observed. The piedmont slope extends forward without interruption as far as we saw it. It should, of course, be remembered that the abandoned Caspian shorelines, wherever they stand on the piedmont plain, may be faint and not easily recognizable ; nevertheless, they were recognized so easily at Baku, Krasnovodsk, and Jebel, that failure to see