I go 
EXPLORATIONS IN TURKESTAN. 
the valley floor is choked with waste from tlie moraine and the underlying- rock. 
The difference in age between this gorge and tliat associated witli llie fourth 
moraine appears greater tlian be- 
tween the gorges of the fourth and 
fifth moraines. Tliis means that 
between the formation of succes- 
sive moraines there must have 
been considerable intervals of ero- 
sion. Where the glacier stood 
during these intervals is not clear. 
It may have retreated above the 
position of the ne.\t moraine and 
again advanced; or it may merely 
have retreated to that ])osition and 
there remained stationar)-. 
(3) Moraines of the Afiidinnii 
Basin. — A third valley, of l)roadly 
open basin form, drained by the 
Mudirum Su* on the south side 
Fig. 134.-<;ross-seclionso( the Khojalshken Valley, to show the shape of the Tian Shan plattaU, sllOWS 
wl!!,',l7,!!f,'„,l,'''V^'%1°'''!i Drawn (rom observa.,on. q,^ moraiueS of foUr aud probablv 
without measurement. 1 he circles mdicale moraines. 1 he lightly ' ' 
shaded portions indicate the amount of erosion since the respective of fivC ageS lying ill regular SC- 
parts of the valley were filled with ice. . , , • 1 ■ 
queuce, without any indication as 
to what happened during the intervals between 
their deposition or as to whether there were any 
intervals when glacial deposition ceased. The 
glacier of this valley is the largest of all those of 
which the moraines were studied ; it reaches a 
maximum length of nearly 50 miles. The thick- 
ness of the ice was so great that at Jubergeiiti pass 
it overflowed toward the north into the valley of 
the Kara Kul River. It was not possible to fol- 
low the Mudirum River to its head, but a side 
valley was examined as far up as a modern moraine. The relations of the moraines 
are illustrated in the accompanying sketch map (fig. 136). At the head of the 
valley are two tiny glaciers, A and B, with little moraines, marked VI. Below 
these is another moraine, V, which seems to be a little older, but may be merely 
a stage of VI. In the next valley to the west is a cirque with a ver)' j'oung 
moraine, V, but no glacier. There is much snow near by, and these little 
moraines were not well seen. The next moraine, I\', is 500 or 600 feet lower, and 
is a large semicircular mass of clearly glacial origin. It is composed of limestone 
Fig. 1 35. — Cross-sections of the three gorges 
of the Khoja Ishken Valley, to show the 
amount of widening and erosion of the 
valley in each case relative to the power 
of the stream and of erosion without refer- 
ence to the actual size. 
*Thc Kirghiz call most of rfiis stream the .\k Sai or White River, and apply the name Mudirum 
to the lower part only, but the name Ak Sai is alnioit as common as Kuzzil Sti, and as this Ak Sai 
empties into another Ak Sai, it seems better to use the less common name. 
