I06 EXPLORATIONS IN TURKESTAN. 
A point between two bays at the west end of Issik Kul is caused by ridges of 
dissected conglomerates, bordered north and south by low gra\'el plains of gentle 
grade, sloping from the Chu toward the lake, and probably representing former 
deltas of the Chu when it flowed into Issik Kul. That it had probably once done 
so was recognized by Severtzof in 1867 (1875, 82). The Chu has now a silt cover 
on its flood plain near the lake, but shows gravels in its .shoals. If the silts were 
laid over the plain of its fonner delta, they have been removed. The Kirghiz have 
led some small canals from the Chu eastward across the southern delta plain toward 
the lake. The water thus gained is distributed on fields of fine soil not far from 
the lake shore. A pair of whitish clay belts, about 5 feet apart, vertically, was 
seen contouring around the slopes that inclose this plain. We took them for 
shorelines at first, supposing that the clay had accumulated in the presence of reeds 
or grass, by which wave action was held off, as is now the case on parts of the Son 
Kul shoreline ; but cla}- belts were not seen eastward along the northern shore. 
These belts are probably 50 feet higher than the well-detennined shorelines traced 
at and below the 25-foot level; moreover, similar clays in greater volume were seen 
at the north base of the conglomerate ridges between the two gravel delta plains, 
and in much greater volume farther down the Chu Valley ; so the origin of the clay 
belts is left in doubt. 
On the north side of Issik Kul the piedmont waste slope is rather e\enh- 
develoj^ed for the first 50 miles eastward from the west end of the lake, although 
some local varicolored ridges rose through the waste slope at a few points where its 
breadth was greater than usual. For the ne.xt 20 miles, nearly to Sezanovka, the 
slope was often made ver)- une\en by a succession of irregular ridges of disturbed 
and dissected basin deposits of variable texture. The finer sandy or silty layers 
here seen were frequenth' co\-ered with hea\')' bowlders up to 8 or 10 feet in diameter. 
Some of the ridges thus formed are naturally eroded ; others have comparatively 
simple fonns, with even scarps 200 or 300 feet high, facing the lake, in which only 
narrow trenches ha\-e been cut It was e\-ident that these ridges resulted from the 
recent disturbance of the earlier basin deposits. 
THE PIEDMONT SLOPES AND VALLEYS. 
Since the disturbance of the earlier basin deposits there has been time enough 
for the intennittent streams to fonn the newer piedmont fans and slopes of waste, 
which now stretch forwai^d for from 3 to 10 miles with moderate declivit}- from 
the mountain base to the lake. Trains of hea\'y bowlders were seen on some of the 
fans, as if marking the paths of exceptionally hea\'}- floods. Parts of these newer 
slopes are of coarse surface materials, and the subangular stones there are darkened 
with "desert varnish." Other parts are more gravelly and of lighter color, as if of 
somewhat more recent date. On both parts the scant}' herbage is not alwa)'s 
uniformly distributed, but sometimes occupies interlacing lanes, inclosing barren 
spaces a few feet in diameter. The delta of the Ula-khol and the abandoned delta 
plains of the Chu are also seemingly of modern date. 
At the east end of the lake Mr. Huntington reports the occurrence of an 
extensive plain 40 miles broad east and west and about the same north and south, 
