普若岗日冰原西侧及念青唐古拉山西坡侧碛垄形态 差异及气候构造成因

Different geometric features of moraines are the result of many factors during their formation, such as tectonics and climate. However, measurements of elevations of such moraines, following with numeric modeling, can help us attain such data as elevation, slope, and aspect of these moraines. Here the author treats one lateral moraine in Puruogangri, central of the Qinghai-Tibet plateau, and two others in Nyainqentanghula Shan, southeast of the Qinghai-Tibet plateau. The results imply that the scale of moraine in Puruogangri, with an asymmetric shape indicated by aspect data, is much smaller and gentler than those in Nyainqentanghula Shan. Analyses and comparison of the morphologic parameters, with the help of references of climate and tectonics, suggest that climate is the major cause of the difference between moraine scales in these two sites, and that climate and tectonics control different slopes together. We then draw a conclusion from the slope differences between different moraines of these two sites that moraines formed in the Nyainqentanghula Shan are younger than those in Puruogangri. The asymmetry of morphology of the moraine in Puruogangri is the result of the impact of a fault here,which is confirmed by interpretation of satellite image. The fault dips northwards, the south part being the hanging wall.