Characteristics of clay minerals in the northern South China Sea and its implications for evolution of East Asian monsoon since Miocene

CORC > 海洋研究所 > 中国科学院海洋研究所 > 海洋地质与环境重点实验室

	Characteristics of clay minerals in the northern South China Sea and its implications for evolution of East Asian monsoon since Miocene
	Wan Shiming 1,2; Li Anchun 1; Xu Kehui 3; Yin Xueming 1
刊名	JOURNAL OF CHINA UNIVERSITY OF GEOSCIENCES
	2008-02-01
卷号	19 期号:1 页码:23-37
关键词	Clay Mineral Sediment Source Analysis East Asian Monsoon Miocene South China Sea
ISSN号	1002-0705
文献子类	Article
英文摘要	Clay mineral assemblages, crystallinity, chemistry, and micromorphology of clay particles in sediments from ODP Site 1146 in the northern South China Sea (SCS) were analyzed, and used to trace sediment sources and obtain proxy records of the past changes in the East Asian monsoon climate since the Miocene, based on a multi-approach, including X-ray diffraction (XRD) and scanning electron microscopy combined with energy dispersive X-ray spectrometry (SEM-EDS). Clay minerals consist mainly of illite and smectite, with associated chlorite and kaolinite. The illite at ODP Site 1146 has very well-to-well crystallinity, and smectite has moderate-to-poor crystallinity. In SEM the smectite particles at ODP Site 1146 often appear cauliflower-like, a typical micromorphology of volcanic smecites. The smectite at ODP Site 1146 is relatively rich in Si element, but poor in Fe, very similar to the smectite from the West Philippine Sea. In contrast, the chemical composition of illite at ODP Site 1146 has no obvious differences from those of the Loess plateau, Yellow River, Yangtze River, and Pearl River. A further study on sediment source indicates 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 clay mineral assemblages at ODP Site 1146 were not only controlled by continental eathering regimes surrounding the SCS, but also by the changing strength of the transport processes. The ratios of (illite+chlorite)/smectite at ODP Site 1146 were adopted as proxies for the East Asian monsoon evolution. Relatively higher ratios reflect strongly intensified winter monsoon relative to summer monsoon, in contrast, lower ratios indicate a strengthened summer monsoon relative to winter monsoon. The consistent variation of this clay proxy from those of Loess plateau, eolian deposition in the North Pacific, planktonic, benthic foraminifera, and black carbon in the SCS since 20 Ma shows that three profound shifts of the East Asian winter monsoon intensity, and aridity in the Asian inland and the intensity of winter monsoon relative to summer monsoon, occurred at about 15 Ma, 8 Ma, and the younger at about 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.; Clay mineral assemblages, crystallinity, chemistry, and micromorphology of clay particles in sediments from ODP Site 1146 in the northern South China Sea (SCS) were analyzed, and used to trace sediment sources and obtain proxy records of the past changes in the East Asian monsoon climate since the Miocene, based on a multi-approach, including X-ray diffraction (XRD) and scanning electron microscopy combined with energy dispersive X-ray spectrometry (SEM-EDS). Clay minerals consist mainly of illite and smectite, with associated chlorite and kaolinite. The illite at ODP Site 1146 has very well-to-well crystallinity, and smectite has moderate-to-poor crystallinity. In SEM the smectite particles at ODP Site 1146 often appear cauliflower-like, a typical micromorphology of volcanic smecites. The smectite at ODP Site 1146 is relatively rich in Si element, but poor in Fe, very similar to the smectite from the West Philippine Sea. In contrast, the chemical composition of illite at ODP Site 1146 has no obvious differences from those of the Loess plateau, Yellow River, Yangtze River, and Pearl River. A further study on sediment source indicates 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 clay mineral assemblages at ODP Site 1146 were not only controlled by continental eathering regimes surrounding the SCS, but also by the changing strength of the transport processes. The ratios of (illite+chlorite)/smectite at ODP Site 1146 were adopted as proxies for the East Asian monsoon evolution. Relatively higher ratios reflect strongly intensified winter monsoon relative to summer monsoon, in contrast, lower ratios indicate a strengthened summer monsoon relative to winter monsoon. The consistent variation of this clay proxy from those of Loess plateau, eolian deposition in the North Pacific, planktonic, benthic foraminifera, and black carbon in the SCS since 20 Ma shows that three profound shifts of the East Asian winter monsoon intensity, and aridity in the Asian inland and the intensity of winter monsoon relative to summer monsoon, occurred at about 15 Ma, 8 Ma, and the younger at about 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.
语种	英语
WOS记录号	WOS:000253958200003
公开日期	2010-12-30
内容类型	期刊论文
源URL	[http://ir.qdio.ac.cn/handle/337002/6191]
专题	海洋研究所_海洋地质与环境重点实验室
作者单位	1.Chinese Acad Sci, Inst Oceanol, Key Lab Marine Geol & Environm, Qingdao 266071, Peoples R China 2.Chinese Acad Sci, Inst Geol & Geophys, Beijing 100029, Peoples R China 3.Coll William & Mary, Sch Marine Sci, Virginia Inst Marine Sci, Gloucester Point, VA 23062 USA
推荐引用方式 GB/T 7714	Wan Shiming,Li Anchun,Xu Kehui,et al. Characteristics of clay minerals in the northern South China Sea and its implications for evolution of East Asian monsoon since Miocene[J]. JOURNAL OF CHINA UNIVERSITY OF GEOSCIENCES,2008,19(1):23-37.
APA	Wan Shiming,Li Anchun,Xu Kehui,&Yin Xueming.(2008).Characteristics of clay minerals in the northern South China Sea and its implications for evolution of East Asian monsoon since Miocene.JOURNAL OF CHINA UNIVERSITY OF GEOSCIENCES,19(1),23-37.
MLA	Wan Shiming,et al."Characteristics of clay minerals in the northern South China Sea and its implications for evolution of East Asian monsoon since Miocene".JOURNAL OF CHINA UNIVERSITY OF GEOSCIENCES 19.1(2008):23-37.