Tian Mountains

I

Introduction

Tian Mountains (Chinese, Tien Shan), major mountain system, Central Asia, extending from the Pamir Knot (see Pamirs) in Kyrgyzstan, north-east along the border between Kyrgyzstan, south-eastern Kazakhstan, and the Xinjiang Uygur (Sinkiang Uighur) Autonomous Region of China. The range is also known as the Tien Mountains (Chinese, “Heavenly Mountains”). The Tian Mountains have a length of about 2,415 km (1,500 mi) and a width of about 320 to 480 km (200 to 300 mi); the system covers about 1,036,000 sq km (400,000 sq mi).

II

Topography

Most of the range lies within China, where it divides the Junggar Pendi (Dzungarian Basin) to the north from the vast, arid Tarim Basin (Tarim Pendi) to the south. In the border area where Kazakhstan, Kyrgyzstan, and China meet is a string of high peaks, notably Pobedy Peak (7,439 m/24,406 ft), the highest in the system, and Khan-Tengri (6,995 m/22,949 ft), from which the 34-km (21-mi) long Muzart glacier descends. West of these peaks, at an altitude of 1,609 m (5,279 ft) is the Kyrgyz lake Ysyk-Köl (Issyk-Kul; 6,099 sq km/2,355 sq mi). In the eastern part of the range, the most striking feature is the Turfan Depression (Turpan Pendi), a 160-km (100-mi) long stretch of lowland reaching 154 m (505 ft) below sea level and enclosed by high mountains. The major rivers, including the Syr Darya, Ili (Yili), and Chu, flow generally westward.

III

Geological Formation and Structure

The ranges of the system, which generally lie along an east-west axis, were lifted up by geological folding during the Palaeozoic era. The crystalline and sedimentary rock has been subject to extensive erosion and to deep faulting; severe earthquakes have occurred along the rim of the system throughout modern times. The ranges are steeply sloped, their crests often incised by glaciers that wind down towards intervening valleys. The largest glaciers occur at high altitudes along the international boundaries, although glaciers 19 km (12 mi) in length are not unusual in the high eastern Tian Mountains.

IV

Vegetation and Animal Life

The northern slopes of the Tian Mountains receive enough moisture to support deep evergreen forests and highland meadows suitable for grazing livestock. There, at an elevation of 853 m (2,800 ft), the fertile Ili Valley lies within two arms of the system. The southern slopes of the mountain system are relatively dry and barren.

The Tian Mountains support a wide variety of animal life. Wolves, red foxes, and ermine live in the general mountain area. The high mountains are home to snow leopards, Siberian ibex, Siberian roe deer, and argali, a type of wild sheep. Brown bears, wild boars, and Eurasian badgers inhabit the forest and meadows. Tolai hares, goitred gazelles, and snakes and lizards populate the desert and semi-arid regions. Redstarts, vultures, Himalayan snowcocks, and wagtails are a few of the birds found in the Tian Mountains.