DOI: 10.5194/cp-12-819-2016
Scopus记录号: 2-s2.0-84966431229
论文题名: Revisiting carbonate chemistry controls on planktic foraminifera Mg / Ca: Implications for sea surface temperature and hydrology shifts over the Paleocene-Eocene Thermal Maximum and Eocene-Oligocene transition
作者: Evans D. ; Wade B.S. ; Henehan M. ; Erez J. ; Müller W.
刊名: Climate of the Past
ISSN: 18149324
出版年: 2016
卷: 12, 期: 4 起始页码: 819
结束页码: 835
语种: 英语
Scopus关键词: carbonate group
; carbonate system
; Eocene-Oligocene boundary
; hydrology
; Hypsithermal
; Paleocene-Eocene boundary
; paleotemperature
; pH
; planktonic foraminifera
; reconstruction
; sea surface temperature
; uncertainty analysis
; Alabama
; United States
; Foraminifera
; Globigerinoides ruber
; Turborotalia
英文摘要: Much of our knowledge of past ocean temperatures comes from the foraminifera Mg / Ca palaeothermometer. Several nonthermal controls on foraminifera Mg incorporation have been identified, of which vital effects, salinity, and secular variation in seawater Mg / Ca are the most commonly considered. Ocean carbonate chemistry is also known to influence Mg / Ca, yet this is rarely examined as a source of uncertainty, either because (1) precise pH and [CO3 2-] reconstructions are sparse or (2) it is not clear from existing culture studies how a correction should be applied. We present new culture data of the relationship between carbonate chemistry and Mg / Ca for the surface-dwelling planktic species Globigerinoides ruber and compare our results to data compiled from existing studies. We find a coherent relationship between Mg / Ca and the carbonate system and argue that pH rather than [CO3 2-] is likely to be the dominant control. Applying these new calibrations to data sets for the Paleocene-Eocene Thermal Maximum (PETM) and Eocene-Oligocene transition (EOT) enables us to produce a more accurate picture of surface hydrology change for the former and a reassessment of the amount of subtropical precursor cooling for the latter. We show that pH-adjusted Mg / Ca and δ18O data sets for the PETM are within error of no salinity change and that the amount of precursor cooling over the EOT has been previously underestimated by ∼ 2 °C based on Mg / Ca. Finally, we present new laser-ablation data of EOT-age Turborotalia ampliapertura from St. Stephens Quarry (Alabama), for which a solution inductively coupled plasma mass spectrometry (ICPMS) Mg / Ca record is available (Wade et al., 2012). We show that the two data sets are in excellent agreement, demonstrating that fossil solution and laser-ablation data may be directly comparable. Together with an advancing understanding of the effect of Mg / Casw, the coherent picture of the relationship between Mg / Ca and pH that we outline here represents a step towards producing accurate and quantitative palaeotemperatures using this proxy. © Author(s) 2016. 资助项目: ISF, Israel Science Foundation
; NERC, Natural Environment Research Council
; NERC, Natural Environment Research Council
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/49034
Appears in Collections: 气候变化与战略
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Recommended Citation:
Evans D.,Wade B.S.,Henehan M.,et al. Revisiting carbonate chemistry controls on planktic foraminifera Mg / Ca: Implications for sea surface temperature and hydrology shifts over the Paleocene-Eocene Thermal Maximum and Eocene-Oligocene transition[J]. Climate of the Past,2016-01-01,12(4)