A Study On Quaternary Glacial Evolution Sequences In The Kanas River, Altai Mountains

The Altai is one of mountain ridges in Central Asia, which spans four countries as:China, Mongolia, Russia and Kazakhstan, the composition of a series of southeast tonorthwest mountains. It is that the southern slope of the middle Altai Mountains in China,Located in the north of Xinjiang Urumqi Autonomous Region. The Kanas River originateson the southern slope of the Youyi Peak, the largest center of modern glaciation of theAltai Mountains in China. the largest center of modern glaciation of the Altai Mountainsin China.there are many types of glaciers, including hanging cirque glaciers, cirqueglaciers, Hanging cirque glaciers, valley glaciers, compound valley glaciers. It is that thesnowline is lowest in China, Due to the geographical latitude in higher, the developmentof which is the most north of china, in modern glacier, and I, between3020and3360m.This area is in control of the westerlies and polar air mass. According to the snow pits ofKanas glacier, the average annual precipitation is700~800mm in the equilibrium line. andthe annual mean temperature is between-7to8℃, which cause the continental glacial.The glaciers have been advanced and retreated dramatically during the glacial-interglacialcycles in Quaternary. Multiple moraines were preserved in the headwater of the KanasRiver valley, recording a complex history of Quaternary glacial cycles and landscapeevolution.There are many landforms of quaternary glaciers in Kanas River valley, the types ofwhich are abundant. the Glacial Erosion landforms have cirque, horn, arete, U valley,sheepback rock, cloak-like valley.the cirque is in layer distribution.the composition of theglaciation sedimentation are lateral moraines, terminal moraines and fluvioglacial deposits.The Formation of Kanas Lake is Interactions of glaciation in last glaciation and faultstructure in the area. The formation of placer gold in this area is related to the quaternaryglacier.In recent years with the advancement of science and technology, the techniques ofmethods have developed rapidly, of dating in the quaternary sediments.The OpticallyStimulated Luminescence is one of the fastest growing technology, which is widely usedin the quaternary sediments of dating. due to its advantages, it is the most potential datingmethod in glacial deposits. In this paper, two fluvioglacial deposits, which collected from the lateral moraines in the main U-shaped valley were determined by optically stimulatedluminescence (OSL) dating techniques, single aliquot regenerative-dose (SAR) protocolwas chosen. Considering the available ages (i.e.14C, OSL、ESR and TL), the principles ofgeomorphology and stratigraphy and the palaeo-environmental data, four conclusionscould be drawn:（1）The dating results are29.42.2ka (K-1) and16.11.4ka (K-2). with the agesbefore and the principles of geomorphology and stratigraphy,we can see: five glacialadvances have been occurred in Kanas River valley Altai Mountains. As follows:TheLittle Ice Age and and the ages equal to MIS2-4, MIS6, MIS12.（2）Through to the comprehensive analysis ofthe dating results, we canknow: TheKanas Glacier is double entry valley glaciers in Neoglaciation for33km long; It is valleyglaciers in the last glaciation for100km long, the length of the glacier9.3times now; It ishuge valley glacier in MIS6for110~120km; It is half of glacier covering in MIS12,when lagerest one this study area.With the results of dating, it was caused in the lastglaciation the sediments sequence in consistent with the geomorphic unit and the formerOSL ages.It is clear that the ages are compellent,and It is possible that the dating in theglacier sediments with OSL.（3）It is oldest the Burqin Ice Age, It is consistent withthe ages ofthe Gaowangfengtills (477.1ka BP and459.746ka BP) in the headwaters of the Urumqi River Valleywhich is in the middle segment of the Tianshan Mountains, and the ages of theZhonglianggang tills （462.9ka BP）in the Bailang River valley Qilian Mountains. Thesedates demonstrate that at least in MIS12, the Altai Mountains entered cryosphere,couplingwith the glacial climate and resulting in the development of glaciers（4）This ice in the Burqin for old ice age of China, and the middle TianshanMountainsarea high peak at Urumqi River Valley moraines age (477.1ka BP;459.746ka BP), awave of Qilian Mountains river ZhongLiang gan moraines age (462.9ka BP) are identicalwith each other. Dating results show that our country and western tianshan mountainmiddle in MIS and uplifting to at least then and the height of the ice age climate phasecoupling, into cryosphere and began to development glaciers.