Temporal and spatial patterns of Cenozoic deformation across the Qaidam Basin, Northern Tibetan Plateau

We conducted a systematic analysis of the temporal and spatial patterns of Cenozoic deformation of the northeastern (NE) and southwestern (SW) parts of the Qaidam Basin, the largest and thickest Cenozoic sedimentary basin within the Tibetan Plateau, by constructing balanced cross-sections traversing the whole basin using high-resolution seismic-reflection data. We found that that these two parts deformed synchronously with similar temporal patterns involving nearly constant NE-SW contraction before c.2.5Ma and much more intense shortening, possibly enhanced by fierce wind erosion, since then. However, the spatial deformation patterns of these two areas differ markedly: an eastward weakening trend in the SW part is not observed in the NE part. We believe that this difference is due to their different boundary conditions. This result places new constraints on the formation mechanisms of the northern Tibetan Plateau.