Kunlun(redirected from Kuenlun)
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Kunlun(ko͝on`lo͝on`), great mountain system of central Asia, between the Himalayas and the Tian Shan, extending c.1,000 mi (1,610 km) E from the Pamir Mts., along the Tibet-Xinjiang border in W China and into Qinghai prov., where it branches into the mountain ranges of central China; it rises to 25,340 ft (7,724 m) in Muztag (Ulugh Mus Tagh), NE Tibet. The Kunlun's main branches are the Altun Mts. (Altyn Tagh) and Nan Shan in the north; the Min Shan in the south; and the Qinling Shan in the east. The Kunlun system acts as a natural barrier between N Tibet and the Tarim basin of Xinjiang; streams rising on the northern slope of the Kunlun disappear into the basin's desert sands. Great sections of the system are inaccessible and uninhabited; there is a very small nomad population, and yaks are the beasts of burden in the high mountain passes.
(Kuenlun), one of the largest mountain systems in Asia, located in China. The Kunlun Mountains extend for about 2,700 km from the Pamirs on the west to the Sino-Tibetan Mountains on the east. The average elevation of the watershed peaks is about 6,000 m in the northern ranges and up to 6,500 m in the south.
Relief. The general trend is nearly latitudinal. Throughout almost their entire length the Kunluns consist of parallel chains of ranges separated by vast depressions and narrow graben-like valleys, whose elevation increases from north to south. The Kunluns rise 1,000–1,500 m above the Tibetan Highlands; in the north, on the side of the Kashgar Plain and the Ala Shan Desert, the relative elevation reaches 4,500 m. Whereas the northern slopes of the Kunlun Mountains are long and complexly dissected, the southern slopes are short, often forming slightly dissected ledges.
Orographically and geomorphologically the Kunluns are subdivided into two unequal parts—a smaller western and a principal eastern part. The western Kunluns (between the Pamirs and the Keriya Valley) consist of three parallel chains of ranges separated by narrow intermontane valleys. The total width of the Kunluns in this area often does not exceed 100 km. The highest summits are found in the west (Kongur, 7,579 m; Muz Tagh Ata, 7,555 m) and in the east, in the basin of the upper reaches of the Khotan River (Muztagh, 7,282 m; Karanghu Tagh, 7,013 m). In the central part of the western Kunluns all the ranges are lower, and even the highest peaks seldom reach 6,000 m. Between the valleys of the Khotan and Keriya rivers the northern chain of the Kunluns is interrupted, and the ranges of the high inner chain border on the Kashgar Plain, descending to it in a great scarp.
The eastern Kunluns are characterized by a complex branching of mountain chains passing around broad intermontane plains. The uniform trend of the ranges is lost here, and individual ranges are often situated at angles to one another. In places the width of the mountain system reaches 600 km. The northern chain of the eastern Kunluns forms an arc bulging to the north, which is often considered to be an independent mountain system. The western branch of the arc, 30–40 km wide, is composed of the Russian and Altyn Tagh ranges. The eastern branch, comprising the Nan Shan system of ranges, is up to 300 km wide and is separated from the main chains of the eastern Kunluns by the Tsaidam Basin. The crests of the ranges rise to 5,400–6,300 m, and the elevation of the intermontane valley floors between them is 3,200–3,600 m. The principal chains of the eastern Kunluns lie between the Tsaidam Basin and the Tibetan Highlands. The orographic pivot of this part of the mountain system is the Arka Tagh (Przheval’skii Range), which has the highest peaks in the Kunluns (Ulugh Muz Tagh, 7,723 m; Chong Karlik Tagh, also known as Shapka Monomakha [Monomakh’s Hat], 7,720 m). Rising vertically for almost 1,000 m, the crest of the range is covered with perpetual snow. The high plains separating the inner chains of the eastern Kunluns have landscapes similar to the cold deserts of the Tibetan-Highlands.
Overall the Kunlun Mountains are characterized by broad, weakly dissected divides with vast sections of an ancient peneplain. There are numerous, often mobile, talus areas in the high mountains. Debris cones are frequently found at the foot of the ranges. Along the northern slopes of the Kunluns are clear manifestations of wind erosion and accumulation, including deflation trenches and the formation in many areas of a loess cover on bedrock, in places at elevations of 4,000 m.
V. M. SINITSYN
Geological structure and minerals. The folded structures of the Kunluns date from the Paleozoic. The anticlinorium of the western Kunluns consists of a crystalline axial zone (composed of Precambrian metamorphic rock breached by Paleozoic granitoids) and the surrounding Paleozoic troughs. The northeastern trough is composed of three complexes of different ages: Lower Paleozoic (sandy shale), Middle Paleozoic (terrigenous redbeds and limestone-siliceous-volcanic), and Upper Paleozoic (terrigenous-carbonate-siliceous-volcanic marine in the northwest and terrigenous continental in the southeast). The less clearly defined southwestern trough has a structure similar to that of the northeast. The eastern Kunluns are composed of Ordovician-Silurian sandstones and shales. In the north they are covered (with an angular unconformity) by a sandy shale, coal-bearing, and volcanic Upper Paleozoic complex, and in the south the cover is of red Triassic sandstones. A Jurassic basin with coal-bearing sandy shale sediments is superimposed on the Middle Paleozoic structures in the east. Precambrian and Upper Paleozoic granitoids are found only in the marginal uplift of the ancient Tarim Massif in the northern ranges. In the Mesozoic and Cenozoic the entire Kunlun Mountains represent an arched block uplift with manifestations of recent volcanic activity in the eastern part, at the sources of the Keriya River and in the Arka Tagh Range. In the western Kunluns there are deposits of placer gold and ore manifestations of iron (in skarns), tin, and tungsten, associated with Upper Paleozoic polymetallic granitoids. Also found are Upper Paleozoic coals, rock crystal, nephrite, and diamonds.
V. A. SHVOL’MAN
Climate. The Kunluns have a markedly continental climate with large annual and daily fluctuations in temperature and exceptional dryness. In the lower mountain regions (those bordering on the Kashgar Plain and the Ala Shan Desert) the mean July temperature is 25°-28°C, and in January the temperature does not fall below -9°C. In the high mountains the mean July temperature does not exceed 10°C, and in winter it often drops to — 35°C. In some places in the foothills the precipitation totals not more than 50 mm a year; approaching the Pamirs and the Sino-Tibetan Mountains, the precipitation increases to 500 mm, up to 80 percent of which falls in the summer.
Glaciation. Despite the great elevation of the Kunluns there is relatively little glaciation because of the extreme dryness of the climate. Glaciers cover a total area of 14,300 sq km, with the principal centers of glaciation at elevations of about 7,000 m. Among these are the massifs of Kongur, Muz Tagh Ata, Muz Tagh, and Chong Karlik Tagh. The largest glacier, Yurun Kash in the Khotan basin, is 39 km long. The glaciers are primarily of the Turkestan type with a poorly developed névé area; they are fed mainly by avalanches. Ancient glaciation was also not widespread. The present snow line lies at an elevation of 5,000–5,200 m in the west and east and at 5,700–5,800 m in the middle part. Perpetual snows are found only on the highest peaks and do not form large névé basins.
Rivers and lakes. The Kunluns are poor in water resources. The annual discharge of all the rivers is estimated at 3,100 cu m per sec, with part of the runoff coming from the adjacent regions of the Karakoram Range, where some of the major rivers (Yarkand, Kara Kash) rise. About 60–80 percent of the annual runoff of the Kunlun rivers occurs in the summer, when intensive thawing of snow and ice in the mountains is accompanied by maximum precipitation. In the winter the rivers often dry up; in the high mountains they freeze. Runoff in the spring and autumn is negligible. The largest lakes, located in the eastern Kunluns, are Koko Nor, a drainless lake in the Nan Shan region, and Orin Nur and Zharin Nur in the upper reaches of the Huang Ho.
Landscapes. Dry steppe and desert landscapes predominate in the Kunluns. Sierozem soils on loesses and loesslike deposits with almost no humus are common. In the western ranges and in the eastern Kunluns, where the moisture conditions are better and the vegetation richer, brown soils occur. Kunlun soils contain many coarse skeletal elements and often are not differentiated into genetic horizons; they are shallow and not fully developed.
Natural conditions are unfavorable for plant growth because of the primitive soil cover, the extreme deficiency of moisture, and, in the high mountains, insufficient warmth. The species composition of the plant communities is poor, and the plant cover is sparse. In the central, most arid part of the Kunluns, desert conditions prevail at all levels. In the lower zone of the mountains barren areas predominate, alternating with small sections having sparse plant covers of Sympegma, Kalidium, Reaumuria, Ephedra, and Nitraria. At elevations of 2,500–5,000 m Sympegma and wormwood mixed with Ephedra, milk vetch, and Eurotia are widespread, and in the high-mountain region (above 5,000 m) there are pulvinate forms of Eurotia, Androsace, tansy, and Acantholimon. Cold desert landscapes predominate.
On the western and eastern margins of the Kunluns the vertical zonality becomes more complex. In the middle-altitude region, in addition to deserts, there are desert-like steppes with less sparse plant covers consisting of wormwoods and some grasses (feather grass, meadow grass, and fescue). At higher elevations mountain steppes and isolated forests of Tien-Shan spruce and treelike juniper alternate with meadows. The lower boundary of the forests lies between 3,500 m and 4,000 m.
Animal life is represented primarily by species from the deserts and steppes of Central Asia, mainly ungulates and rodents. The most common ungulates are mountain sheep (arkharin the west and kukuyaman in the east), mountain goats, and wild asses; wild yaks are also encountered. The rodents (marmots and voles) are found chiefly on meadow slopes. Pikas are numerous. The common predators are wolves, foxes, bears and snow leopards.
In the Kunluns permanent settlements are found only in the valleys of the large rivers, below 3,000 m. The principal occupations of the inhabitants are farming (up to 3,000 m wheat is raised and up to 3,600 m, barley) and nomadic herding (sheep, goats, and yaks). Caravan routes are rare. Of the three roads for motor vehicles, one passes along the northern slopes of the Kunluns on the southern edge of the Kashgar Plain and two lead into Tibet, crossing the Kunluns in the west and east.
The most important geographic information about the Kunluns has been provided by Europeans, primarily Russian travelers. Especially fruitful were the trips of the Russians N. M. Przheval’skii, M. V. Pevtsov, K. I. Bogdanovich, P. K. Kozlov, V. I. Roborovskii, and V. A. Obruchev and those of the Swedish scientist S. Hedin in the late 19th and early 20th centuries.
REFERENCESSinitsyn, V. M. Tsentral’naia Aziia. Moscow, 1959.
Iusov, B. V. Tibet, Moscow, 1958.
Kun’lun’ i Tarim. Moscow, 1961.
Fizicheskaia geografiia Kitaia. Moscow, 1964.
Petrov, M. P. Pustyni Tsentral’noi Azii, vols. 1–2. Moscow-Leningrad, 1966–67.
Murzaev, E. M. Priroda Sin’tsziana i formirovanie pustyn’ Tsentral’noi Azii. Moscow, 1966.
V. M. SINITSYN