the recent past the lakes of Central and Western Asia have been more extensive than at present. The length of the epochs of high water was so short that no beaches or bluffs were cut upon hard rocks, although very distinct ones were cut in soft silts and gravels. In the lake of Kogneh, also, three probable periods of high water are indicated, and these are seen to be connected with river terraces of apparently the same date, and also with older ones.
TERRACES AMONG THE MOUNTAINS FROM MESHED TO BIRJAND.
From the basin of Khaf our route led westward into the mountains to the east of Birjand, thence southeastward to Sistan, and finally back by another route northwestward to Meshed. Sistan is so important that it will be reserved for fuller treatment later. The mountains from the border of the Sistan basin, near Birjand,
Fig. 159.—A slightly terraced Valley in the Mountains of Binalud Kuh, 30 miles north of Turbat-i-
Haideri, March 3, 1904.
to the vicinity of Binalud Kuh, near Meshed, present so many features in common and withal so few of special importance, that they may be described in general ternis without the tedium of particulars. As a rule, the parts of the mountainous districts of which the traveler in Persia sees most are the areas of deposition, the basins. In these it is not to be expected that terraces either of tectonic or climatic origin should be found, for the streams oftentimes come to an end in gravel, even though the form of the mountains round about shows that they might find ready outlet from the basins, as they probably have done in the past, if only they were provided with sufficient water. A significant feature of the basins is that almost universally gravel is encroaching upon finer sediments of a silty or sandy character.
Wherever valleys were seen in which water sometimes flows, they were found to be terraced almost without exception. The terraces are for the most part cut in