Late Miocene uplift of the NE Tibetan Plateau inferred from basin filling, planation and fluvial terraces in the Huang Shui catchment

Abstract

The geomorphological evolution of the marginal areas of the Tibetan Plateau may provide valuable information for reconstructing the tectonic movements of the region. This study reports on a morpho-tectonic analysis of the Huang Shui catchment (tributary of the Yellow River), in the Northeastern Tibetan Plateau using a digital elevation model and field observations. One prominent bevelled surface, preliminarily interpreted as a peneplain surface, is recognized at around 2750m altitude. It corresponds with the top of the relict sedimentary fill of large tectonic basins, and the adjacent summits. After the formation of this peneplain, a terrace sequence was formed along the Huang Shui river. The transition of peneplain surface formation to incision was dated as older than 10–6Ma using the biochronology of micromammalian assemblages from fluvial terraces and the depositional record of the basin fill. The river incision into the former peneplain is attributed to an important uplift event around 10–17Ma.