Magnetostratigraphy and palaeoclimatic significance of late Tertiary aeolian sequences in the Chinese Loess Plateau

Abstract

The aeolian Red Clay sequence in the central part of the Chinese Loess Plateau was investigated in an attempt to obtain magnetostratigraphic and palaeoclimatic records. From the results, we deduce that aeolian dust accumulation and the related East Asia palaeomonsoon system began at least 7.6 Myr ago, and that the Tibetan Plateau had reached a significant elevation by that time. The Late Tertiary palaeoclimatic history of the Red Clay as reflected by magnetic susceptibility is reconstructed for the time period 7.6-2.5 Ma. Increases in aeolian dust accumulation for the last 7.6 Myr appear to have a close relation with the uplift processes of the Tibetan Plateau. The remarkable increase of aeolian dust accumulation beginning at 3.2 Ma appears to reflect the influence of an increasing global ice volume on the East Asian monsoon and aeolian dust accumulation.