PHYSIOGRAPHIC OBSERVATIONS. 
139 
of the higher portions, but entirely worn down in some places. From a distance 
they were seen to cut the steep slopes coming down to the lake on the west. 
From the eastern shore of Lake Kara Kul the land rises with a slope of i foot 
or less in 100, and holds this till it meets the fans from the bordering mountains, 
whence it rises more and more rapidly and bends up sharply at the mountain's base 
East Crest 
A 
East shore 
sediments 
62 
Fig. 101. — An east-west section of the Kara Kul Basin. 
(fig. loi). The surface of large areas between the lake and these eastern fans consists 
of nude, finely stratified, blue-gra\- clays. A considerable depth of these sediments 
is well matted with tape-like grass lying flat and varying in width from '3 mm. to 
3 mm. The roots are about fj mm. in diameter, and spring from the bottom of 
the wide blade, the fine leaves sprouting just above them. The leaves are light 
brown and although ver)- thin will bear a tension of one-half ounce and are verj' 
pliable. The clays are, as a whole, of the finest flour, but contain minute flakes of 
Fig. 102. — Section of Kara Kul sediments exposed in Hillock Bluff about 100 feet above Lake. 
mica and here and there a layer with small angular pebbles. The lamination is 
ver}- perfect ; it is easy to split off pieces a foot in area and only half an inch thick, 
although the same piece can be cnunbled between the fingers. 
A large proportion of the Kara Kul sediments lie horizontal, but there are also 
areas of vers- much disturbed stratification where the surface is broken into 
irregularly disturbed mounds or little hillocks, among which deflation and wind 
carving have fonned miniature bluflfs exposing the structure. The layers seen in 
