294 THE BASIN OF EASTERN PERSIA AND SISTAN. 
there is no lava cap the upper portion of the bhiffs is broken into three smaller 
terraces (x, y, 2, fig. 169), due to the alternate strata of gravel and silt, while lower 
down the hardness of the green clays causes minor benches. As viewed from below 
the crest of the higher bluffs sometimes shows its true flat-topped character, but oftener 
it appears like a jagged range of high hills. Below the ragged terraces of the dark 
gravel cap the softly outlined but steep slopes of the beautifully tinted clays spread 
into fine sprawling spurs, separated by cleft-like gorges and buttressed with round 
greenish bastions where the harder, uuweathered lacustrine clays fonn terraces. At 
the base of the cliffs outstanding portions of clay fonn graceful pj-ramids or domes, 
soft in outline and banded with harmonious colors — pale-pink, green, yellow, and 
purple, which ])lend insensibly one into another. 
After the cutting of the first shoreline, the lake fell and perhaps became dry 
during an interfluvial period. When next we have a record the water stood at B 
(fig. 169), and again cut a bluff, low and insignificant where it stood below its pre- 
decessor at Bereng, for example, but higher where it completely undercut the latter. 
T 1( 
, ,^ 
\5_m 
=N-S>-.»>^„-U'5-s:ia^ .. 
issEisaiSffis^^ _ 
ism^sin^issi^ 
\ 
LaJte 
_____^^--__^-_^-_^^__-_— ___ 
— 
Fig. 1 69. — Ideal Cross-secrion of the Lake Terraces and Bluffs on the Northwest 
Shore of the I-.ake of Sistan. 
as at Daghaz. North of this latter point a great change had taken place since the 
fonnation of the earlier bluffs. The whole country had been uplifted to a height 
which reached a maximum of 300 feet at Cliaku, as shown by the height of the 
older shoreline. Probably the elevation was in progress during the earlier fluvial 
as well as during the interfluvial epoch, for the terrace-top below Chaku slopes 
more steeply than would be the case if it had all been produced by water standing 
at a single level. At present the lake is cutting insignificant bluffs or depositing 
beaches. Thus, on the northwestern shore of the Hamun-i-Sistan, we have a record 
of two fluvial or lacustral epochs and two interfluvial epochs. During the first 
the water stood approximately 25 feet higher than now, and remained there long 
enough to cut verj- far back into the surrounding country. Toward the end of 
this epoch the region around Chaku began to rise. Then came a time of falling 
water, and, by inference, an interfluvial epoch, when the lake became almost dr}-. 
When the water again rose in the succeeding fluvial epoch the movements of 
uplift had almost come to an end and the land stood in practically its present 
position. For a second time bluffs were cut. The level of the water was but little 
higher than to-day, but the area and hence the volume of the lake must have been 
vastly larger; lastl\-, the water fell to its present level, and is now fonning an insig- 
nificant strand. This strand, however, lies higher than the level where most of the 
lake's erosive action takes place at present, and it seems probable that the level of 
the water is now falling. 
