A Cretaceous-Eocene depositional age for the Fenghuoshan Group, Hoh Xil Basin: Implications for the tectonic evolution of the northern Tibet Plateau

Research reveals that the Fenghuoshan Group in Qinghai Hoh Xil, marking the onset of terrestrial deposition in the Hoh Xil Basin, was deposited between 85 and 51 million years ago. This finding challenges previous debates on its age and stratigraphic relationships, providing critical insights into the uplift history of northern Tibet. By integrating radiometric dating, biostratigraphic data, and magnetostratigraphy, the study proposes that these strata likely originated from the central Qiangtang Terrane, sharing sediment sources with Cretaceous rocks in the Nima Basin. Additionally, late Oligocene basalt flows capping tilted Fenghuoshan Group strata suggest a shift from Eocene-Oligocene deformation to crustal shortening cessation by the late Oligocene, reshaping our understanding of the tectonic evolution of northern Tibet.

Staisch, L. M., Niemi, N. A., Hong, C., Clark, M. K., Rowley, D. B., & Currie, B. (2014). A Cretaceous-Eocene depositional age for the Fenghuoshan Group, Hoh Xil Basin: Implications for the tectonic evolution of the northern Tibet Plateau. Tectonics, 33(3), 281–301. https://doi.org/10.1002/2013tc003367