Discovery and Significance of Quaternary Glacial Vestiges in the Hexigten Area of the Southern Da Hinggan Mountains, Inner Mongolia

1 Introduction Hexigten is situated at the eastern part of the Inner Mongolian Plateau, south of the Da Hinggan Mountains and northwest of Chifeng City, Inner Mongolia, China. It is also at the junction of the Da Hinggan Mountians, Inner Mongolian Plateau and Yanshan Mountains. It is about 650 km north of Beijing. The geographic coordinates are 116?30'?118?20'E and 42?20'?44?10'N (Fig. 1). The elevation range is from 1100 m to 1700 m, and the highest peak (2029 m) of the Da Hinggan…

Discovery and Significance of Quaternary Glacial Vestiges in the Hexigten Area of the Southern Da Hinggan Mountains, Inner Mongolia

The question whether there have been Quaternary glaciations in the Da Hinggan area has puzzled glacial geologists for many years because no sufficient glacial evidence has been found in this area. The study of Quaternary glaciers in the Da Hinggan area is also a key issue of the glaciology in China because of the special location of this area. In the past two years, a large number of complete and typical glacial vestiges have been found in Hexigten in the southern Da Hinggan Mountains, such as fossil cirque groups, horns, knife-edge crests, terminal moraines, glacial stepped stones. These landforms are located at a watershed, which are thus impossible to be formed due to tectonic processes, water or weathering, but can only be formed by glaciation. The calculated flat indexes of the fossil cirques in the Hexigten are 1.7-4.5, 4-5 and 1.3-5, which are within the range of 1.7-5 that is the flat index of real cirques. The typical and complete moraines have also been found in this area. All these glacial vestiges prove that the Quaternary glaciers did exist in the Da Hinggan Mountains of eastern China. Thus, it is of important scientific significance for the research on Chinese, even the global climatic and environmental evolution since the Quaternary.