Rapid exhumation at ~ 8 Ma on the Liupan Shan thrust fault from apatite fission-track thermochronology: Implications for growth of the northeastern Tibetan Plateau margin

The Liupan Shan Mountain is one of the outermost ranges in northeastern Tibetan Plateau. The onset of its uplift provides insight on whether the plateau grew sequentially outward or broad areas of the plateau deformed simultaneously. The apatite fission-track method can be used to date rapid cooling as the result of unroofing of rocks in response to tectonically induced vertical motion. Fission-track data from apatite in Early Cretaceous sedimentary strata exposed on the hanging-wall of Liupan Shan thrust fault in northeastern Tibet suggest that a late Cenozoic rapid cooling events occurred at 7.3–8.2 Ma or ~ 8 Ma. This age apparently dates fault activity of the Liupan Shan thrust in response to northeastward growth of the Tibetan Plateau uplift and lateral growth, which continues today. Numerous studies of the Tibetan Plateau suggest that the onset of deformation in eastern and northern margin of Tibetan Plateau occurred in the latest Miocene.