THE RANGES NEAR ISSIK KUL. 
75 
Alexander FUinge, looking 
firmed b)- many features noted afterward. The south slope of the range had a 
hackly surface, due to the erosion of many small branching valleys among its 
\aricolored crystalline ledges ; but when seen in profile a few days later from the 
west end of Issik Kul, the smaller irreg- 
ularities of the slope were lost in a 
remarkably simple outline, sketched in 
figure 42. The crest rose above the 
snow patches of mid-July; one of its 
highest parts, isolated between two en- 
croaching valley heads, had an obliquely truncated summit in line with the long 
back (south) slope. The northeastern face of the range was much steeper and more 
sharply dissected by the side streams of the Chu. It was therefore concluded that 
the Alexander range is a faulted block of a peneplain, of which the former lowland 
surface is now uplifted, tilted to the south and moderately dissected, while the 
steeper northern faulted face is deeply carved in great spurs and ravines. The 
Kach-kar basin is apparenth' an aggraded area on the relatively depressed southern 
side of the block, as will be again considered farther on. 
Three small mountain masses (A, B, C, fig. 43), between the Alexander range 
and Issik Kul, had much the appearance of tilted and dissected blocks, sloping to 
the south and facing to the north. If this be true, their displacement ceased longer 
ago and their dissection has progressed farther than is the case in certain parts of 
the Wasatch range of Utah which I examined in 1902 ; for the spurs on the 
faulted face of the ranges by Issik Kul do not possess tenninal facets, and the 
ravines between the spurs on both the front and the back slopes have open mouths. 
On the other hand, the back 
slopes of these ranges still have 
general profiles of greater regu- 
larity than tliose of the Utah 
ranges that I have seen. This 
may be because the Issik Kul 
ranges were more smoothly worn 
down in the pre-faulting cycle 
than were the Utah ranges. The 
only sure indication of recent 
dislocation among these ranges 
was a fault scarp, 10 to 50 feet in 
height, more than a mile in 
length, and trending northwest- 
ward across the gravel fans at the northeastern comer of range B. It should be 
stated that this scarp was only seen at a distance of a mile or more ; but it was 
closely examined through a good field-glass from different points of view and in 
different lights. The manner in which it was crossed by the gullies radiating from 
the mountain ravines left no doubt in my mind as to its meaning and origin, 
A large fan, spreading into the Urta-takoi basin on the south side of the same range. 
ilftfe^ 
ALEX- '^ 
RANGE VSl 
LOFTY %mmi^j2^M 
SNOW COVERED :^My^ ^j^^^vvVllMlllrtoW'*"*^ 
-'^'^ -.. c, ALA-TAU 
20 MILES ? 
Fig. 43. — Rough Sketch Map of the Ranges southwest of Issik Kul. 
