| 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, Zhifang1; Li, Tiegang1 ; Crosta, Xavier2; Algeo, Thomas3; Chang, Fengming1; Zhai, Bin4; Li, TG
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| 2013-09-01 | |
| 发表期刊 | GLOBAL AND PLANETARY CHANGE
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| ISSN | 0921-8181 |
| 卷号 | 108页码:1-14 |
| 文章类型 | Article |
| 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.; 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. |
| 关键词 | Vital Effects Ethmodiscus Rex Blooms Surface Stratification Co2 Sink Marine Silica Cycle Late Pleistocene Eastern Philippine Sea |
| 学科领域 | Physical Geography ; Geology |
| DOI | 10.1016/j.gloplacha.2013.06.003 |
| URL | 查看原文 |
| 收录类别 | SCI |
| 语种 | 英语 |
| WOS研究方向 | Physical Geography ; Geology |
| WOS类目 | Geography, Physical ; Geosciences, Multidisciplinary |
| WOS记录号 | WOS:000323470800001 |
| WOS关键词 | CARBON ISOTOPIC FRACTIONATION ; SOUTHERN-OCEAN PHYTOPLANKTON ; EQUATORIAL PACIFIC ; GROWTH-RATE ; DEEP-SEA ; IRON HYPOTHESIS ; BOUND NITROGEN ; PHILIPPINE SEA ; ORGANIC-CARBON ; INDIAN-OCEAN |
| WOS标题词 | Science & Technology ; Physical Sciences |
| 引用统计 | |
| 文献类型 | 期刊论文 |
| 条目标识符 | http://ir.qdio.ac.cn/handle/337002/16313 |
| 专题 | 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 |
| 第一作者单位 | 中国科学院海洋研究所 |
| 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. |
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