Stratigraphic Evidence for the Uplift of the Tibetan Plateau between 1.1 and 0.9 myr Ago

Uplift of the Tibetan Plateau is manifest not only in widespread denudation, but also by an increased deposition rate of sediment, near or far from the exhumed regions. Our results indicate that the mass accumulation rate (MAR) of eolian dust increased between 1.1 and 0.9 myr ago. We associate this increase in MAR and median grain size with uplift of the Tibetan Plateau and its adjacent regions during this period. This Middle Pleistocene uplift can also be evidenced by the age of volcanism in the marginal region, the existence of thick conglomerate deposits surrounding the uplifted plateau, and the increased sedimentation rate of lacustrine deposits in the Qaidam Basin (northeastern Tibetan Plateau) between 1.1 and 0.9 myr ago. The correlation between the loess and marine records indicates that after 0.9 myr ago, these two records correlate well. This good correlation probably suggest that the Middle Pleistocene upheaval event not only brought the plateau into the cryosphere, but also enhanced the coupling of regional-scale Chinese loess transportation and deposition to the global ice volume variations through its effects on glacial grinding, rock denudation, and east Asian monsoonal circulation.