Development of the East Asian monsoon; mineralogical and sedimentologic records in the northern South China Sea since 20 Ma

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doi: 10.1016/j.palaeo.2007.07.009
Author(s): Wan Shiming; Li Anchun; Clift, Peter D.; Stuut, Jan-Berend W.
Author Affiliation(s): Primary:
Chinese Academy of Sciences, Institute of Oceanology, Qingdao, China
University of Aberdeen, United Kingdom
Bremen University, Federal Republic of Germany
Volume Title: Palaeogeography, Palaeoclimatology, Palaeoecology
Source: Palaeogeography, Palaeoclimatology, Palaeoecology, 254(3-4), p.561-582. Publisher: Elsevier, Amsterdam, Netherlands. ISSN: 0031-0182 CODEN: PPPYAB
Note: In English. 65 refs.; illus., incl. 2 tables, sketch maps
Summary: We here reconstruct the past change of the East Asian monsoon since 20 Ma using samples from Ocean Drilling Program (ODP) Site 1146 in the northern South China Sea based on a multi-proxy approach including a monomineralic quartz isolation procedure, identification of clay minerals by X-ray Diffraction (XRD) and grain-size analysis of isolated terrigenous materials. Terrigenous supply to ODP Site 1146 was dominated by changes in the strength of multiple sources and transport processes. Grain-size data modeled by an end-member modeling algorithm indicate that eolian dust from the arid Asian inland and fluvial input have contributed on average 20% and 80% of total terrigenous material to ODP Site 1146, respectively. Specifically, about 40-53% of the total (quartz+feldspar) and only 6-11% of the total clay is related to eolian supply at the study site. Detailed analysis of the sedimentary environment, and clay minerals combined with previous studies shows that smectite originates mainly from Luzon, kaolinite from the Pearl River and illite and chlorite from the Pearl River, Taiwan and/or the Yangtze River. The proportion and mass accumulation rate (MAR) of the coarsest end-member EM1 (interpreted as eolian dust), ratios of (illite+chlorite)/smectite, (quartz+feldspar)% and mean grain-size of terrigenous materials at ODP Site 1146 were adopted as proxies for East Asian monsoon evolution. The consistent variation of these independent proxies since 20 Ma shows three profound shifts in the intensity of East Asian winter monsoon relative to summer monsoon, as well as aridity of the Asian continent, occurred at ∼15 Ma, ∼8 Ma and the youngest at about 3 Ma. In comparison, the summer monsoon intensified contemporaneously with the winter monsoon at 3 Ma. The phased uplift of the Himalaya-Tibetan plateau may have played a significant role in strengthening the Asian monsoon at ∼15 Ma, 8 Ma and 3 Ma. Abstract Copyright (2007) Elsevier, B.V.
Year of Publication: 2007
Research Program: ODP Ocean Drilling Program
Key Words: 12 Stratigraphy, Historical Geology and Paleoecology; Asia; Cenozoic; China; Clay minerals; East Asian Monsoon; Erosion; Far East; Feldspar group; Framework silicates; Grain size; Leg 184; Luzon; Mineral composition; Monsoons; North Pacific; Northwest Pacific; ODP Site 1146; Ocean Drilling Program; Pacific Ocean; Paleoclimatology; Paleogeography; Pearl River; Philippine Islands; Provenance; Quartz; Sheet silicates; Silica minerals; Silicates; South China Sea; Terrigenous materials; Tibetan Plateau; West Pacific; X-ray diffraction data; Yangtze River
Coordinates: N192724 N192724 E1161622 E1161622
Record ID: 2007128383
Copyright Information: GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data from CAPCAS, Elsevier Scientific Publishers, Amsterdam, Netherlands