EOLIAN RECORD OF THE CHINESE LOESS PLATEAU SINCE THE NEOGENE

Two eolian deposit sequences since Neogene were studied for the lithostratigraphy and magnetostratigraphy. This paper shows that the marker loess/paleosol and red clay layers of the two sections are well correlated with other profiles on the Chinese Loess Plateau, and the bottom age of eolian sequences is about 7.2MaB.P., which may mark the initiation of eolian accumulation on the Chinese Loess Plateau. The red clay loess paleosol sequences not only record the formation and evolution of East Asian paleomonsoon, but also include the imprints of the step wise uplifting of Tibetan Plateau and ice volume change of Northern Hemisphere from Neogene. The sedimentation rate of eolian deposits reflects the aridity of dust source regions and intensity of the past atmospheric circulation. It gradually increased from 7.2MaB.P. and especially since 4.5MaB.P., which indicated that the dust source region of inner Asia was becoming more aridity, and the intensity of east Asia winter monsoon was becoming stronger and stronger from Neogene to Quaternary.