Quantification of Asian Dust Source Variabilities in Silt and Clay Fractions since 10Ma by Parallel Factor (PARAFAC) Endmember Modeling at IODP Site U1425 in the Japan Sea

Abstract

Japan sea sediments consist of various detrital materials of eolian and riverine origin. Understanding the provenance of eolian dust is vital for reconstructing the variability of wind patterns and monsoons in the past. New and complete eolian accumulation rates from Taklimakan, Gobi, and Ordos are reconstructed at Integrated Ocean Drilling Program (IODP) Site U1425 in the Japan Sea using parallel factor (PARAFAC) endmember modeling. Our results show that Taklimakan dust is dominated by the silt fraction, while Gobi dust is dominated by the clay fraction, and they are controlled by the relative contributions of different pathways of dust transport, such as the westerly winds and East Asian winter monsoon (EAWM). Clay-size dust from Gobi increased during three periods, late Miocene global cooling (LMGC), intensification of Northern Hemisphere Glaciation (iNHG), and mid-Pleistocene Transition (MPT), which reflected increased EAWM winds associated with global cooling and glaciation. Taklimakan became the major dust contributor to the Japan Sea sediments during the warmer climate periods in the latest Miocene to early Pliocene and the Late Pleistocene, where westerly wind activity dominated eolian transport. Dust from Ordos increased greatly 0.95-0.85 Ma due to enhanced Asian aridification since 2Ma in Northwest China. Detrital flux from Japanese islands suggests that the East Asian summer monsoon (EASM) was stronger 9.6-8 Ma and weakened from 8 Ma to the Pleistocene.