ELEVATION DISTRIBUTION PATTERN OF RED CLAY BEDS IN THE REGIONS EAST AND WEST OF LIUPANSHAN AND NEOTECTONIC SIGNIFICANCE

Late Cenozoic red clay beds which widespread in the northeastern region of Qinghai-Tibet Plateau, not only records late Cenozoic climatic and environmental changes,but also provide indication for Neotectonics of Qinghai-Tibet Plateau. Using Digital Elevation Model technique and together with field observation,the authors analyse elevation distribution pattern of red clay beds on the both sides of Liupanshan, and discuss their neotectonic significance. The result shows that there occurred several phases of differential uplifts on the both sides of Liupanshan since the middle Miocene. The red clay began to deposit in the western region of Liupanshan (the Longxi area), where uplift started earlier than in the Ordos region. Differential uplift occurred across the Liupanshan since the late Miocene and has been enhanced since the late Pliocene, which changed the geomorphic features to be higher in the west than in the east,just the opposite to those in earlier times.