Potential role of giant marine diatoms in sequestration of atmospheric CO2 during the Last Glacial Maximum: delta C-13 evidence from laminated Ethmodiscus rex mats in tropical West Pacific

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	Potential role of giant marine diatoms in sequestration of atmospheric CO2 during the Last Glacial Maximum: delta C-13 evidence from laminated Ethmodiscus rex mats in tropical West Pacific
	Xiong, Zhifang 1; Li, Tiegang1 ; Crosta, Xavier 2; Algeo, Thomas 3; Chang, Fengming 1; Zhai, Bin 4; Li, TG
刊名	GLOBAL AND PLANETARY CHANGE
	2013-09-01
卷号	108 页码:1-14
关键词	vital effects Ethmodiscus rex blooms surface stratification CO2 sink marine silica cycle late Pleistocene Eastern Philippine Sea
ISSN号	0921-8181
通讯作者	Li, TG
中文摘要	Giant marine diatoms, blooming or aggregating within deep chlorophyll maxima under stratified conditions, can generate substantial production and a large export flux of organic carbon from surface waters. However, their role in regulating glacial-interglacial variation in atmospheric pCO(2) remains unclear. Here, we report the organic carbon isotopic compositions of Ethmodiscus rex diatoms (delta C-13(E.) (rex)) and bulk sediments (delta C-13(org)) from a sediment core in the eastern Philippine Sea dated to similar to 19.5-31.0 kyr B.P. and consisting of (from youngest to oldest) (1) laminated E. rex diatom mats (LDM), (2) diatomaceous clay (DC), and (3) pelagic clay (PC). Our results suggest that delta C-13(E.) (rex) provides a better record of palaeoceanographic processes during LDM and DC deposition than delta C-13(org) because of reduced differential vital effects in near-monospecific E. rex fractions. We used the isotopic composition of the coarse E. rex fraction (delta C-13(E.) (rex) ((>154) (mu m))) to calculate the CO2 partial pressure of eastern Philippine Sea surface waters (pCO(2-sw)) during the Last Glacial Maximum (LGM). Our pCO(2-sw) records suggest that the eastern Philippine Sea switched from being a strong CO2 source during DC deposition to a weak CO2 sink during LDM deposition. The role of the eastern Philippine Sea as a CO2 sink during the LGM was promoted by elevated primary production and, to a lesser extent, intensified water-column stratification. These observations highlight the potential role of giant marine diatoms in the sequestration of atmospheric CO2 during the LGM and, hence, support changes in biogenic silica fluxes as a potential cause of lower glacial atmospheric CO2. Our findings are consistent with an eolian source of silica, as proposed by the 'silica hypothesis' and the 'silicon-induced alkalinity pump hypothesis' but not by the 'silicic acid leakage hypothesis.' (C) 2013 Elsevier B.V. All rights reserved.
英文摘要	Giant marine diatoms, blooming or aggregating within deep chlorophyll maxima under stratified conditions, can generate substantial production and a large export flux of organic carbon from surface waters. However, their role in regulating glacial-interglacial variation in atmospheric pCO(2) remains unclear. Here, we report the organic carbon isotopic compositions of Ethmodiscus rex diatoms (delta C-13(E.) (rex)) and bulk sediments (delta C-13(org)) from a sediment core in the eastern Philippine Sea dated to similar to 19.5-31.0 kyr B.P. and consisting of (from youngest to oldest) (1) laminated E. rex diatom mats (LDM), (2) diatomaceous clay (DC), and (3) pelagic clay (PC). Our results suggest that delta C-13(E.) (rex) provides a better record of palaeoceanographic processes during LDM and DC deposition than delta C-13(org) because of reduced differential vital effects in near-monospecific E. rex fractions. We used the isotopic composition of the coarse E. rex fraction (delta C-13(E.) (rex) ((>154) (mu m))) to calculate the CO2 partial pressure of eastern Philippine Sea surface waters (pCO(2-sw)) during the Last Glacial Maximum (LGM). Our pCO(2-sw) records suggest that the eastern Philippine Sea switched from being a strong CO2 source during DC deposition to a weak CO2 sink during LDM deposition. The role of the eastern Philippine Sea as a CO2 sink during the LGM was promoted by elevated primary production and, to a lesser extent, intensified water-column stratification. These observations highlight the potential role of giant marine diatoms in the sequestration of atmospheric CO2 during the LGM and, hence, support changes in biogenic silica fluxes as a potential cause of lower glacial atmospheric CO2. Our findings are consistent with an eolian source of silica, as proposed by the 'silica hypothesis' and the 'silicon-induced alkalinity pump hypothesis' but not by the 'silicic acid leakage hypothesis.' (C) 2013 Elsevier B.V. All rights reserved.
学科主题	Physical Geography ; Geology
WOS标题词	Science & Technology ; Physical Sciences
类目[WOS]	Geography, Physical ; Geosciences, Multidisciplinary
研究领域[WOS]	Physical Geography ; Geology
关键词[WOS]	CARBON ISOTOPIC FRACTIONATION ; SOUTHERN-OCEAN PHYTOPLANKTON ; EQUATORIAL PACIFIC ; GROWTH-RATE ; DEEP-SEA ; IRON HYPOTHESIS ; BOUND NITROGEN ; PHILIPPINE SEA ; ORGANIC-CARBON ; INDIAN-OCEAN
收录类别	SCI
原文出处	10.1016/j.gloplacha.2013.06.003
语种	英语
WOS记录号	WOS:000323470800001
公开日期	2014-07-17
内容类型	期刊论文
源URL	[http://ir.qdio.ac.cn/handle/337002/16313]
专题	海洋研究所_海洋地质与环境重点实验室
通讯作者	Li, TG
作者单位	1.Chinese Acad Sci, Inst Oceanol, Key Lab Marine Geol & Environm, Qingdao 266071, Peoples R China 2.Univ Bordeaux 1, UMR CNRS EPOC 5805, F-33405 Talence, France 3.Univ Cincinnati, Dept Geol, Cincinnati, OH 45221 USA 4.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,Crosta, Xavier,et al. Potential role of giant marine diatoms in sequestration of atmospheric CO2 during the Last Glacial Maximum: delta C-13 evidence from laminated Ethmodiscus rex mats in tropical West Pacific[J]. GLOBAL AND PLANETARY CHANGE,2013,108:1-14.
APA	Xiong, Zhifang.,Li, Tiegang.,Crosta, Xavier.,Algeo, Thomas.,Chang, Fengming.,...&Li, TG.(2013).Potential role of giant marine diatoms in sequestration of atmospheric CO2 during the Last Glacial Maximum: delta C-13 evidence from laminated Ethmodiscus rex mats in tropical West Pacific.GLOBAL AND PLANETARY CHANGE,108,1-14.
MLA	Xiong, Zhifang,et al."Potential role of giant marine diatoms in sequestration of atmospheric CO2 during the Last Glacial Maximum: delta C-13 evidence from laminated Ethmodiscus rex mats in tropical West Pacific".GLOBAL AND PLANETARY CHANGE 108(2013):1-14.