DOI: 10.1016/j.epsl.2017.10.013
Scopus记录号: 2-s2.0-85033664917
论文题名: Controls over δ44/40Ca and Sr/Ca variations in coccoliths: New perspectives from laboratory cultures and cellular models
作者: Mejía L.M. ; Paytan A. ; Eisenhauer A. ; Böhm F. ; Kolevica A. ; Bolton C. ; Méndez-Vicente A. ; Abrevaya L. ; Isensee K. ; Stoll H.
刊名: Earth and Planetary Science Letters
ISSN: 0012821X
出版年: 2018
卷: 481 起始页码: 48
结束页码: 60
语种: 英语
英文关键词: Ca isotopic fractionation
; calcium isotopes
; CaSri–Co model
; coccolith calcification
; coccolithophores
; desolvation
Scopus关键词: Biomineralization
; Bone
; Efficiency
; Isotopes
; Seawater
; Solvation
; Calcium isotopes
; Co-modeling
; Coccolithophores
; Desolvation
; Isotopic fractionations
; Calcium
; biological uptake
; calcification
; calcium
; climate change
; coccolith
; isotopic composition
; isotopic fractionation
; modeling
; seawater
; strontium
; water chemistry
; Emiliania huxleyi
; Gephyrocapsa oceanica
; Haptophyceae
英文摘要: Coccoliths comprise a major fraction of the global carbonate sink. Therefore, changes in coccolithophores' Ca isotopic fractionation could affect seawater Ca isotopic composition, affecting interpretations of the global Ca cycle and related changes in seawater chemistry and climate. Despite this, a quantitative interpretation of coccolith Ca isotopic fractionation and a clear understanding of the mechanisms driving it are not yet available. Here, we address this gap in knowledge by developing a simple model (CaSri–Co) to track coccolith Ca isotopic fractionation during cellular Ca uptake and allocation to calcification. We then apply it to published and new δ44/40Ca and Sr/Ca data of cultured coccolithophores of the species Emiliania huxleyi and Gephyrocapsa oceanica. We identify changes in calcification rates, Ca retention efficiency and solvation–desolvation rates as major drivers of the Ca isotopic fractionation and Sr/Ca variations observed in cultures. Higher calcification rates, higher Ca retention efficiencies and lower solvation–desolvation rates increase both coccolith Ca isotopic fractionation and Sr/Ca. Coccolith Ca isotopic fractionation is most sensitive to changes in solvation–desolvation rates. Changes in Ca retention efficiency may be a major driver of coccolith Sr/Ca variations in cultures. We suggest that substantial changes in the water structure strength caused by past changes in temperature could have induced significant changes in coccolithophores' Ca isotopic fractionation, potentially having some influence on seawater Ca isotopic composition. We also suggest a potential effect on Ca isotopic fractionation via modification of the solvation environment through cellular exudates, a hypothesis that remains to be tested. © 2017 Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/110190
Appears in Collections: 影响、适应和脆弱性 气候变化事实与影响
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作者单位: Dept. Geología, Universidad de Oviedo, Arias de Velasco s/n, Oviedo, Asturias 33005, Spain; Geological Institute, Department of Earth Science, ETH, Sonneggstrasse 5, Zürich, 8092, Switzerland; Institute of Marine Sciences, University of California Santa Cruz, 1156 High St., Santa Cruz, CA, United States; GEOMAR Helmholtz Zentrum für Ozeanforschung Kiel, Wischhofstrasse 1-3, Kiel, 24148, Germany; Aix-Marseille Université, CNRS, IRD, CEREGE UM34, 13545 Aix en Provence, France; UNESCO Intergovernmental Ocean Commission, 1 rue Miollis, Paris cedex 15, 75732, France
Recommended Citation:
Mejía L.M.,Paytan A.,Eisenhauer A.,et al. Controls over δ44/40Ca and Sr/Ca variations in coccoliths: New perspectives from laboratory cultures and cellular models[J]. Earth and Planetary Science Letters,2018-01-01,481