244 THE BASIN OF EASTERN PERSIA AND SISTAN.
The lava cap lies horizontal ; the shales dip about 20° to the north or northwest. The shales are but slightly consolidated, and do not appear to be of great age. Their resemblance to the formations of Sistan, to be described later, is so close that it may be significant.
Twenty miles southeast of the above section, at a point a few miles west of Husseinabad, on the main tributary of the Chahak basin, the valley walls consist of highly folded green clay shales of much the saine composition as those of the section just given, although more indurated. It is probable that they form the
" lower members of the same series, for similar shales are seen at intervals between the two sections. The Husseinabad shales show a strong overthrust from east to west ; that is, out from the mountains toward the great basin of the Dasht-i-Lut (fig. i6o). It should be noted that these beds, like the older shales at Zorabad,
must have been deposited in water of at least moderate depth, which preserved nearly the saine conditions for a long period. The recent strata at Chahak, on the other hand, like those at Sistan, seem to have been deposited under changing conditions, which favored first the deposition of green and then of pink clays. In the next basin we shall come to pink beds deposited entirely under subaerial conditions.
The Bajistan Basin.—Bajistan, 4o miles north of Tun, lies on the southern
margin of a large " kavir," or salt playa, which, according to Curzon's map, extends some 75 miles northeast and southwest, and from io to 3o in the other direction. The playa, at most times, contains a very small amount of standing water surrounded by a broad white plain of salt mixed with silt, muddy in winter, dry and powdery in summer. About 25 miles northeast of the edge of the playa and 20 miles southwest of Turbat-i-Haideri, the gently sloping plain of Bajistan rises into a low line of hills a thousand feet above the " kavir." These hills are composed for the most part of reddish or pink silts which attain a thickness of several hundred feet. At intervals the silts are interrupted by layers of sand from io to 20 feet thick and of a reddish-brown color. These strata of alternating silt and sand are soft and unconsolidated ; they are folded to such an extent that dips of 15° are not uncommon, and they extend around the edge of the basin and along its sides for some miles. Apparently they were deposited in the basin at a time when it was larger. They have since been uplifted and warped, while the central deposits into which they merge have remained undisturbed. In structure, color, and texture the Bajistan strata suggest the more sandy portions of the pink strata at Sistan. They bear a stronger resemblance to the pink deposits of the Tertiary in Central Turkestan and the Kashgar basin. To a less degree they resemble the deposits of the Jam and Nemeksar basins, although at Bajistan no gypsum was noticed. It is probable that all these red and pink strata are of subaerial origin or were deposited in very shallow saline playas or estuaries. No other explanation seems to account for the absence of fossils, the presence of gypsum, the red color, and the alternations between sand and finer silt.
Blanford cites a few instances of deposits which apparently belong to the same class as those mentioned above. Near Abarik (a, p. 485), on the edge of the Dasht-i-Lut between Bam and Kirman, " are some high cliffs of shales and con-