Paleoproductivity and paleoredox conditions during late Pleistocene accumulation of laminated diatom mats in the tropical West Pacific

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	Paleoproductivity and paleoredox conditions during late Pleistocene accumulation of laminated diatom mats in the tropical West Pacific
	Xiong, Zhifang 1; Li, Tiegang1 ; Algeo, Thomas 2; Nan, Qingyun 1; Zhai, Bin 3; Lu, Bo 1
刊名	CHEMICAL GEOLOGY
	2012-12-12
卷号	334 页码:77-91
关键词	Diatom mats Redox Paleoproductivity Ethmodiscus rex West Pacific Last Glacial Maximum
ISSN号	0009-2541
通讯作者	Li, TG (reprint author), Chinese Acad Sci, Inst Oceanol, Key Lab Marine Geol & Environm, Qingdao 266071, Peoples R China.
英文摘要	Paleoproductivity and paleoredox conditions were reconstructed in a sediment core in the Parece Vela Basin of the eastern Philippine Sea. The core consists of three units, from youngest to oldest: (1) laminated diatom mats (LDM) formed by Ethmodiscus rex during the last Glacial Maximum (similar to 18-28 kyr B.P.), (2) diatomaceous clay (DC), and (3) pelagic clay (PC). Elevated levels of export productivity during LDM deposition are indicated by high values for excess Ba, opal content, and TOC/Ti ratios. Estimated rates of organic carbon degradation (ca. 98%), opal mass accumulation (average 1322 g m(-2) yr(-1)), and corrected organic carbon flux (average 248 g m(-2) yr(-1)) are comparable to high-productivity regions of the modem ocean. The LDM is also characterized by moderate enrichment of redox-sensitive elements such as U. Mo, Cd, and Zn, highly S-34-depleted pyrite sulfur isotopic compositions (indicating bacterial sulfate reduction in a sulfate-unlimited system), and C-S-Fe systematics reflecting limitation of pyrite formation by organic matter rather than reactive Fe availability. These features suggest mainly suboxic conditions in bottom waters but development of sulfidic-anoxic conditions at or close to the sediment-water interface. Association of intensified anoxia with productivity maxima indicates that export production was a more important control on bottom water redox conditions than lateral ventilation. The DC and PC accumulated under oxic to suboxic conditions. Our observations suggest that redox environments during deposition of laminated marine sediments are more complicated and varied than previously thought, and, thus, the use of sediment lamination as an indicator of anoxic bottom water conditions must be approached cautiously. (C) 2012 Elsevier B.V. All rights reserved.
学科主题	Geochemistry & Geophysics
收录类别	SCI
原文出处	10.1016/j.chemgeo.2012.09.044
语种	英语
WOS记录号	WOS:000313306600007
公开日期	2013-09-24
内容类型	期刊论文
源URL	[http://ir.qdio.ac.cn/handle/337002/12511]
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.Univ Cincinnati, Dept Geol, Cincinnati, OH 45221 USA 3.Minist Land & Resources, Qingdao Inst Marine Geol, Key Lab Marine Hydrocarbon Resource & Geol, Qingdao 266071, Peoples R China
推荐引用方式 GB/T 7714	Xiong, Zhifang,Li, Tiegang,Algeo, Thomas,et al. Paleoproductivity and paleoredox conditions during late Pleistocene accumulation of laminated diatom mats in the tropical West Pacific[J]. CHEMICAL GEOLOGY,2012,334:77-91.
APA	Xiong, Zhifang,Li, Tiegang,Algeo, Thomas,Nan, Qingyun,Zhai, Bin,&Lu, Bo.(2012).Paleoproductivity and paleoredox conditions during late Pleistocene accumulation of laminated diatom mats in the tropical West Pacific.CHEMICAL GEOLOGY,334,77-91.
MLA	Xiong, Zhifang,et al."Paleoproductivity and paleoredox conditions during late Pleistocene accumulation of laminated diatom mats in the tropical West Pacific".CHEMICAL GEOLOGY 334(2012):77-91.