Neotectonic activities in the Qiangtang Basin and their geological and environmental effects

The Qiangtang Basin is the largest Mesozoic-Cenozoic basin in the northern part of the Qinghai-Xizang Plateau.The current hot spots of geological research for the basin focus on the Palaeo-Tethys evolution and petroleum geology,and little has been known for the Cenozoic geology of the basin.It is inferred,on the basis of Cenozoic stratigraphy,volcanic rocks and regional unconformities,that the Cenozoic tectonic activities in the basin have undergone three phases of evolution: erosion,planation and crustal thickening during the Palaeogene;highly compression and folding during the Miocene,and slow and overall uplifting of the plateau during the Pliocene to the Holocene.The neotectonic activities outlined above apparently have an important effect on the highly uplifted areas,semi-desert areas,sand storms,flash floods,debris flows,landslides,avalanches of snow and glaciers,and earthquakes in the Qiangtang Basin.