Distribution and Formation of Fluvial Terraces in Huangshui Catchment(Northeastern Tibetan Plateau) and Its Tectonic Implication

River evolution at margins of the Tibetan Plateau may provide valuable information for understanding climatic change and tectonic movement of the past. Here we focus on the Huangshui River,a tributary of the Yellow River,crossing a series of tectonically subsided and uplifted areas that show diversity patterns of terrace formation.The distribution of fluvial terrace is studied by mapping and dating.Three terraces in Haiyan basin,four terraces in Huangyuan basin,19 terraces in Xi’ning basin,nine terraces in Ping’an basin,five terraces in Ledu basin and 12 terraces in Minhe basin are recognized.Magne-