Acta Geographica Sinica ›› 2015, Vol. 70 ›› Issue (5): 739-750.doi: 10.11821/dlxb201505006

• Orginal Article • Previous Articles     Next Articles

Geomorphological process of late Quaternary glaciers in Kanas river valley of the Altay Mountains

Wei ZHANG1,2(), Yanjing FU1, Beibei LIU2, Liang LIU1, Zhijiu CUI2, Yuanhuang SHI1, Siwen WANG1   

  1. 1. College of Urban and Environmental Sciences, Liaoning Normal University, Dalian 116029, Liaoning, China
    2. College of Urban and Environmental Sciences, Peking University, Beijing 100871, China
  • Received:2015-02-08 Revised:2015-03-25 Online:2015-05-20 Published:2015-06-11
  • Supported by:
    National Natural Science Foundation of China, No,41271093, No.41230743, No.40971010

Abstract:

Multiple glacial advances/retreats have occurred in Kanas region of the Altay Mountains. Glacial erosive and accumulative landforms are not only very important for the analysis of the regional geomorphological process but also meaningful for the research on global change. According to the field investigation on the Quaternary geomorphology in the lower part of the Kanas Lake outlet in the main valley, this paper measured the altitude of multiple level U-shaped valley in different regions and confirmed the highest limit of glacial boulders and their spatial distribution. Using the electron spin resonance (ESR) method, we dated the glacial tills of the different moraines preserved along the main valley. Results of the glacial sequences, extent and glacial geomorphological process showed that four glacial advances occurred the lower part of the Kanas valley. Compared with the previous research results, these glaciations can be assigned as the Zhonglianggan glaciation, corresponding to the marine isotope stage 12 (MIS12), MIS8/10 glaciation, Penultimate glaciation (MIS6), and the last glacial cycle (LGC). LGC glacial advance can be further divided into three stages which correspond to MIS 4, 3, and 2. Based on the distribution of the three level U-shaped valleys, we concluded that the extent of glaciers decreased with time. The thickness of the glacier during Zhonglianggan glaciation was 50-395 m from the Glacial Station to the end of the glacier, and the length and width are also the largest at that time. The three-dimension extent showed that the glaciers were distributed in the main valley and on both sides of the ridges. The thickness was 102-199 m and 88-269 m during the MIS8/10 and the Penultimate glaciation, and the glacier reached near Tuojingwan. Well persevered multiple level U-shaped valley bottom on the eastern slope of the main valley near the region of Yazehu Lake indicated that the Quaternary glaciers have the warm glacier features such as strong activities, flowability and continuity. Clear asymmetry that occurred in the Kanas main valley showed that the development of the glacial valley was affected by regional climate and topography.

Key words: Altay Mountains, Kanas river valley, late Quaternary, glacial sequence, geomophological process