sîrt, strewn with sandstones, many-coloured marls, gypsum, and saline incrustations, and studded with tarns, but nearly destitute of vegetation. This bleak region is exposed to snow-storms even in June and July, and in some years the snow never melts in the hollows throughout the summer.
| Fig. 99.—Routes of Explorers in the Western Tian-shan. | |
| Scale 1 : 9,000,000. | |
| |
 Postal Highways.
|
 Reinthal, 1868.
|
 Divers Routes.
|
 Kaulbars, 1869.
|
 Valikhanov, 1858.
|
 Kostenko, 1876.
|
 Golubev, 1859.
|
 Kuropatkin, 1876–7.
|
 Venyukov, 1859–60.
|
 Prejvalsky, 1877.
|
 Sieverzov, 1854–68.
|
 Regel, 1876–9.
|
 Osten-Sacken, 1867.
|
 Forsyth, 1874.
|
 120 Miles.
| |
The Terskei Ala-tau is continued westwards under divers names, as are all the parallel chains with which it is connected by transverse ridges. The lacustrine plains are probably more numerous here than elsewhere in the Tian-shan system. But of all the formerly flooded basins one only remains, the Son-kul, a fresh-water lake about the size of Lake Geneva, encircled by steep sides of green porphyry, and draining through a small stream to the Narin. One of the most remarkable of these dried-up plains is the Kashkar valley, source of the Kashkar, the main head-stream of the Chu. It communicates by the Shamsi Pass with the northern plain.
North of Kokan the Tian-shan is continued by the Talas-tau, from 2,500 to 3,000 feet high, which branches off in several ridges from the Alexander Mountains, and falls gradually south-west, west, and north-westwards to the steppes. The Kara-tau, or "Black Mountain," the last spur of the Tian-shan towards the north-west, seldom exceeds 6,500 feet in height, but is geographically of great importance, as forming the water-parting between the Sir and Chu basins. It also abounds most in coal, iron, copper, and argentiferous lead.
