气候变化领域集成服务门户(CCPortal): Monsoon-influenced variation of clay mineral compositions and detrital Nd-Sr isotopes in the western Andaman Sea (IODP Site U1447) since the late Miocene

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DOI	10.1016/j.palaeo.2019.109339
	Monsoon-influenced variation of clay mineral compositions and detrital Nd-Sr isotopes in the western Andaman Sea (IODP Site U1447) since the late Miocene
	Lee J.; Kim S.; Lee J.I.; Cho H.G.; Phillips S.C.; Khim B.-K.
发表日期	2020
ISSN	0031-0182
卷号	538
英文摘要	Nd-Sr isotopes (εNd, 87Sr/86Sr) of detrital particles, clay mineral compositions, and Δ13C of sediment organic matter (Δ13CSOM) at the International Ocean Discovery Program (IODP) Expedition 353 Site U1447 in the western Andaman Sea were measured to reveal the sediment provenance changes and/or weathering intensity variations in association with the Indian monsoon intensity change. The shipboard age model based on biostratigraphic data and paleomagnetic reversals shows that IODP Site U1447 preserves late Miocene (~10 Ma) sediments. Nd/Sr isotope systematics demonstrates that the sediments originated mainly from the Myanmar region, including the Irrawaddy River, Salween River, Sittang River and Indo-Burman-Arakan Ranges without a significant change of sediment provenance since the late Miocene. Thus, temporal variations of clay mineral compositions, represented as smectite/(illite + chlorite) [S/(I + C)], indicate the long-term variations of physical/chemical weathering intensity attributable to intensity changes of Indian winter/summer monsoon. A gradual decreasing trend of S/(I + C) ratios indicates stronger physical and/or weaker chemical weathering since the late Miocene, as a result of strengthening of Indian winter monsoon (and/or weakening of Indian summer monsoon), which seems be closely related to global cooling since the late Miocene. Distinct decrease of S/(I + C) ratios occurred at ~9.2–8.5 Ma, ~3.6 Ma, ~2.4 Ma, and ~1.2 Ma, which may be attributed to the combined effect of both global cooling and Tibetan Plateau Uplift as a local response. In addition, Δ13CSOM values at IODP Site U1447 were higher at ~3.5 Ma and after 1.5 Ma when S/(I + C) ratio was minima, which may imply an increase of C4 plant in Myanmar region as a result the strong Indian winter monsoon (or weak Indian summer monsoon). © 2019 Elsevier B.V.
英文关键词	Indian monsoon; Paleoclimate; Provenance; Weathering intensity
语种	英语
来源期刊	Palaeogeography, Palaeoclimatology, Palaeoecology
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/150647
作者单位	Department of Oceanography, Pusan National University, Busan, 46241, South Korea; Division of Polar Paleoenvironment, Korea Polar Research Institute, Incheon, 21990, South Korea; Department of Geology and Research Institute of Natural Science, Gyeongsang National University, Jinju, 52828, South Korea; Institute for Geophysics, Jackson School of Geosciences, University of Texas at Austin, Austin, TX 78712, United States
推荐引用方式 GB/T 7714	Lee J.,Kim S.,Lee J.I.,et al. Monsoon-influenced variation of clay mineral compositions and detrital Nd-Sr isotopes in the western Andaman Sea (IODP Site U1447) since the late Miocene[J],2020,538.
APA	Lee J.,Kim S.,Lee J.I.,Cho H.G.,Phillips S.C.,&Khim B.-K..(2020).Monsoon-influenced variation of clay mineral compositions and detrital Nd-Sr isotopes in the western Andaman Sea (IODP Site U1447) since the late Miocene.Palaeogeography, Palaeoclimatology, Palaeoecology,538.
MLA	Lee J.,et al."Monsoon-influenced variation of clay mineral compositions and detrital Nd-Sr isotopes in the western Andaman Sea (IODP Site U1447) since the late Miocene".Palaeogeography, Palaeoclimatology, Palaeoecology 538(2020).