High late Miocene–Pliocene elevation of the Zhada Basin, southwestern Tibetan Plateau, from carbonate clumped isotope thermometry

Abstract

The timing and pattern of Tibetan Pla- teau rise provide a critical test of possible mechanisms for the development and sup- port of high topography, yet views range widely on the history of surface uplift to modern elevations of ~4.5 km. To address this issue we present clumped isotope ther- mometry data from two well-studied ba- sins in central and southwestern Tibet, for which previous carbonate δ 18 O data have been used to reconstruct high paleoeleva- tions from late Oligocene to Pliocene time. Clumped isotope thermometry uses mea- surements of the 13 C- 18 O bond ordering in carbonates to constrain the temperature (T(Δ47)) and δ 18 O value of the water from which the carbonate grew. These data can be used to infer paleoelevation by exploiting the systematic decrease of surface tempera- ture and the δ 18 O-based paleoaltimetry and with paleontological and isotopic data indicating the presence of cold- adapted mammals living in a cold, high-ele- vation climate. We suggest that late Neogene elevation loss across the Zhada Basin catch- ment probably related to local expression of east-west extension across much of the south- ern Tibetan Plateau at this time.