194 EXPLORATIONS IN TURKESTAN. 
of Kan Su. It shows something of morainic topography, although tliis is not ver\- 
marked. The slopes are thoroughly graded and covered with grass, and the moraine 
as a whole is cut by several subparallel valleys, two of which are occupied by 
streams and have slightly terraced sides, while the others are abandoned, and seem 
to be stream channels of glacial times. Their heads are abruptly cut off by the 
fourth moraine, which lies at an elevation of about 9,500 feet, where there is a 
sudden rise in the valley floor, and where the main valleys which are not beheaded 
contract somewhat. At the top of this rise lies the distinct frontal ridge of the 
fourth moraine, horseshoe-shaped and inclosing a depression. The rest of this 
moraine has a pronounced glacial topography, although the slopes are ])erfectly 
graded. Moraines Nos. 3 and 4 appear to be of different but not widely sepa- 
rated ages. The vegetation of both has reached what may be called the stage of 
complete occupation; that is, they are covered with a fine growth of grass, except in 
the valleys, where there are some trees. The fifth and last of the old moraines, on 
the contrary,-, has not reached this stage. It begins at an elevation of 10,100 feet, 
where there is a sudden change to \er\- rough moraine topography, which seems to 
be of considerably later date than that on which it lies. Instead of the surface being 
smooth and grassy and almost free from stones, the rough slopes are covered with 
angular fragments of rock, among which are scattered cedar trees and a growth of 
thin, weedy grass quite unlike the turf below. The bowlders, too, are larger, more 
ntimerous, and more angular than those of the other moraines. The difference 
between this fifth moraine and its predecessor is more marked than that between 
the adjacent older moraines. The present moraine at an elevation of 10,500 feet is 
quite as sharply distinguished from the fifth as the fifth is from the fourth, and the 
change is of the same sort. The present moraine exhibits in many places a sharp 
line of division, above which the rock waste is even more angular and fresh than 
below, and above which there is practically no soil filling the interstices of the rock 
and hence absolutely no vegetation. Much of the moraine lies as a cover on the 
ice itself 
In its lower portion the modern moraine spreads out, so that for a short dis- 
tance it fills the whole width of the valley. Higher up, however, the moraine, or 
rather the o-lacier itself with a cover- 
ing of moraine, lies in an inner valley 
cut in moraine stuff of an older date. 
This is represented in the accom- 
panying cross-section through the 
valley at an elevation of about 1 1 ,000 
feet (see fig. 137). The portion A rep- 
resents the rock valley composed of "-'"''^ "«"* of valley. B=n.oraine of third or fourth 
•^ ^ epoch. C=modern glacier. D=niodera moraine. D'=bit 
limestone below and purple slate of modem moraine winch has overflowed B. 
above ; B represents an older moraine, F'g- 137.— Cross-section of the Kan Su Valley at an elevation 
' ^ . of 11.000 feel. 
either No. 3 or No. 4, which was 
formed so long ago that its slopes are thoroughh- graded and are well co^•ered with 
grass, and bowlders have almost disappeared. Yet it is not so old but that it still 
retains signs of a morainic topography, though this is so far destroyed that the 
