no 
EXPLORATIONS IN TURKESTAN. 
"III'"-.iIII///...um;, 
25 foot 
beach "•"""". 
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= ■'■ ?.oV 
= ""■.„o;!,. """"'■""" 
3 o,''o.6*"'""nii''»i((v 
example, a reef 15 or 20 feet high was built across a valley that was 30 or 40 feet 
deep. In a third example, beds of silt had been laid on a valley floor behind a 
reef, but at present the reef and silts are both trenched b\- the stream, which is 
washing cobbles through them. In this district some trenches of the 25-foot reef 
were 30 feet wide and 6 feet high on the outer face, with cobbles up to 6 or 8 
inches in diameter; and one of the cut bluffs was 8 or 10 feet high. East of 
Sazanovka Mr. Huntington reports a beach nearly 100 feet wide and a cut bluff 
35 feet high. Here and farther east the elevated shoreline is usually indicated on 
the 2-verst Russian map. The increase in the strength of these features from 
west to east is probably to be accounted for by the prevalence of waves caused by 
westerly winds, whose action would be 
least effective at the west end of the lake. 
The only point where we saw a rocky 
shoreline was between Chelpan-ata and 
Kurum-dinskya stations, about 50 miles 
from the west end of the lake, where a low 
granite bluff rose at the lake border. It 
stood in a small em bay men t, because the 
piedmont slopes had grown somewliat 
farther forward on each side of it. Strati- 
fied deposits of rather fine texture, covered 
with bowlders, rested on the lateral slopes 
of the granite. These seemed to be of 
earlier date than the modern piedmont 
slopes. Two ele\-ated beaches ha\'e been 
fonned by undercutting the steep slopes 
of angular waste on the granite bluff, as in fig. 76. The upper beach is the stronger 
of the two, and is recognized not only b)- its fonn, but by the abrupt change from 
angular blocks above its line to rounded cobbles below. Here only was an)- direct 
suggestion found as to the relative date of the two beaches. It seemed that, if the 
lower one had been made first, it would have been more obscured than it is by 
waste from the upper one ; hence the lake probabl)' rose rapidl)- to the 25-foot beach 
and paused during its fall at the lo-foot beach. 
At the eastern end of the lake, the highest beach is described b)- Mr. Hunting- 
ton as contouring around all the land arms that separate the drowned valleys of 
the plain. Its height there is given as 30 feet. The 2-verst map shows the shore- 
line then to have been even more irregular than it is now. The beach is easily 
distinguished from the valley terraces, for it runs at a level and ends somewhat 
inland from the bay heads, where the valle)- floors rise to its level ; while the terraces 
have sloping floors and extend farther up the vallej-s. 
When Issik Kul was first described to us as a lake without an outlet and with 
abandoned shorelines, we had hopes of finding a record that might compare with that 
of the Bonneville basin, but there seems to be little likeness between the two. Issik 
Kul only just fails of having an outlet to-day, and, as will be shown below, its level has 
probably been regelated by overflow to the ri\'er Chu through much of its subrecent 
J'SsiK KIJL 
Fig. 75. — Diagram of the relation ot a Valley, the raised 
Beaches, and the present Shoreline of Issik Kul. 
