DOI: 10.1016/j.gloplacha.2013.06.003
论文题名: Potential role of giant marine diatoms in sequestration of atmospheric CO2 during the Last Glacial Maximum: δ13C evidence from laminated Ethmodiscus rex mats in tropical West Pacific
作者: Xiong Z. ; Li T. ; Crosta X. ; Algeo T. ; Chang F. ; Zhai B.
刊名: Global and Planetary Change
ISSN: 0921-8258
出版年: 2013
卷: 108 起始页码: 1
结束页码: 14
语种: 英语
英文关键词: CO2 sink
; Eastern Philippine Sea
; Ethmodiscus rex blooms
; Late Pleistocene
; Marine silica cycle
; Surface stratification
; Vital effects
Scopus关键词: Ethmodiscus rex blooms
; Late Pleistocene
; Philippine seas
; Silica cycle
; Vital effects
; Deposition
; Glacial geology
; Isotopes
; Phytoplankton
; Silica
; Surface waters
; Carbon dioxide
; biogenic material
; biogenic structure
; carbon dioxide
; carbon flux
; carbon isotope
; carbon sequestration
; carbon sink
; chlorophyll
; diatom
; Last Glacial Maximum
; marine environment
; paleoceanography
; silica
; stratification
; Pacific Ocean
; Pacific Ocean (Tropical)
; Pacific Ocean (West)
; Philippine Sea
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 pCO2 remains unclear. Here, we report the organic carbon isotopic compositions of Ethmodiscus rex diatoms (δ13CE. rex) and bulk sediments (δ13Corg) from a sediment core in the eastern Philippine Sea dated to ~19.5-31.0kyr 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 δ13CE. rex provides a better record of palaeoceanographic processes during LDM and DC deposition than δ13Corg because of reduced differential vital effects in near-monospecific E. rex fractions. We used the isotopic composition of the coarse E. rex fraction (δ13CE. rex (>154μm)) to calculate the CO2 partial pressure of eastern Philippine Sea surface waters (pCO2-sw) during the Last Glacial Maximum (LGM). Our pCO2-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.'. © 2013 Elsevier B.V. URL: https://www.scopus.com/inward/record.uri?eid=2-s2.0-84880392548&doi=10.1016%2fj.gloplacha.2013.06.003&partnerID=40&md5=33973c07764f756037301a0efadc2750
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/11164
Appears in Collections: 全球变化的国际研究计划
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作者单位: Key Laboratory of Marine Geology and Environment, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China
Recommended Citation:
Xiong Z.,Li T.,Crosta X.,et al. Potential role of giant marine diatoms in sequestration of atmospheric CO2 during the Last Glacial Maximum: δ13C evidence from laminated Ethmodiscus rex mats in tropical West Pacific[J]. Global and Planetary Change,2013-01-01,108.