Fig. I34.--Cross-sections of the Khoja Ishken Valley, to show the shape of the Tian Shan plateau, shows
and relative size of the three gorges. Drawn from observation, old moraines of four and probably without measurement. The circles indicate moraines. The lightly
shaded portions indicate the amount of erosion since the respective of five ages lying in regular se-
parts of the valley were filled with ice.
quence, without any indication as
to what happened during the intervals between
their deposition or as to whether there were any z
intervals when glacial deposition ceased. The _:
glacier of this valley is the largest of all those of r~r=r _ _ ? = r
which the moraines were studied ; it reaches a ------_-- –?–'
maximum length of nearly 5o miles. The thick- Fig. 135.—Cross-sections of the three gorges
ness of the ice was so great that at Jubergenti pass of the Khoja Ishken Valley, to show the
it overflowed toward the north into the valley of amount of widening and erosion of thevalley in each case relative to the power
the Kara Kul River. It was not possible to fol- of the stream and of erosion without refer-
low the MudirumRiver to its head, but a side ence to the actual size.
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 very young moraine, V', but no glacier. There is much snow near by, and these little moraines were not well seen. The next moraine, IV, is 500 or 600 feet lower, and is a large semicircular mass of clearly glacial origin. It is composed of limestone
*The Kirghiz call most of this stream the Ak Sai or White River, and apply the name Mudirum to the lower part only, but•the name Ak Sai is almost as common as Kuzzil Su, and as this Ak Sai empties into another Ak Sai, it seems better to use the less common name.