Abstract:

The precise division of Bayan Har Mountain Group with complex lithology and widely distributed in the East Kunlun is of great significance to the stratigraphic unit division and structure property analysis. After geometric and atmospheric correction for ASTER images of Bayan Har Mountain in the East Kunlun orogenic belt, the images of principal component analysis(PCA) and band ratio(BR) are obtained by the methods  of lithological information extraction, such as the principal component analysis and mineral index. According to the different images and field geological survey, identification and extraction of Bayan Har Mountain Group lithology information are carried out in the study area. The results show that the upper Bayan Har Mountain Group (T₃by) mainly in the south is only divided into two lithology sections because of the unobvious difference of images, which lithology is mainly gray-dark gray silty slate and sandstone. However, the lower Bayan Har Mountain Group (T₁by) in the north is divided into four lithology sections instead of the above two sections in the south, i.e. dark gray siltstone and phyllite(section a), gray-green fine sandstone(section b), yellow-brown fine sandstone(section c) and dark gray fine-grained sandstone slates(section d), and the tones and textures of the images are different. The study shows the advantages of extraction of lithological information by using RS in the plateau, and provides a reference for stratigraphic unit division and comparison for Bayan Har Mountain Group.

Key words: East Kunlun orogenic belt, Bayan Har Mountain Group, ASTER, lithological information