Syntectonic Sediment Recycling Controls Eolian Deposition in Eastern Asia Since ∼8 Ma

Global cooling and/or Tibetan Plateau uplift have long been regarded as the principal drivers of late Cenozoic central Asian aridification and the resulting widespread accumulation of eolian deposits in eastern Asia. However, these two factors are unable to form large source areas of fine-grained sediments enhancing eolian deposition synchronously from northern Tibet to North Pacific. Here we provide magnetostratigraphic and detrital apatite fission-track evidence for a major sediment recycling event in northern Tibet at ∼8 Ma, coeval with a sudden increase in eolian deposition, which we ascribe to syntectonic erosion of uplifted friable fluvio-lacustrine sediments and selective entrainment by the westerly winds during basin deformation. Our results emphasize the importance of widespread and persistent occurrence of fine-grained sediments along the pathway of westerlies to produce voluminous dust deposits. These findings suggest that the onset of eolian deposition may not be directly related to global cooling or uplift of mountain ranges.