Mg ∕ Ca and δ18O in living planktic foraminifers from the Caribbean, Gulf of Mexico and Florida Straits
Mg ∕ Ca and δ18O in living planktic foraminifers from the Caribbean, Gulf of Mexico and Florida Straits
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加勒比海、墨西哥湾和佛罗里达海峡活体浮游有孔虫中的 Mg ∕ Ca 和 δ18O
DOI：
10.5194/bg-15-7077-2018
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发表时间：
2018
期刊：
影响因子：
4.9
通讯作者：
J. Schönfeld
中科院分区：
文献类型：
--
作者：
A. Jentzen;D. Nürnberg;E. Hathorne;J. Schönfeld
抽象的。过去的海洋温度和盐度可以近似为
稳定氧同位素（δ 18 O）和
化石有孔虫试验中的Mg scinCa测量，
不同的成功。为了进一步完善这种方法，我们收集了生活中的
通过净取样和抽取海洋表层水，
加勒比海、墨西哥湾东部和佛罗里达海峡。分析
八个活体浮游植物的δ ~（18）O和Mg ~（18）ScinCa
种（Globigerinoides sacculifer，Orbulina universa，
Neogloboquadrina dutertrei，Pulleniatina dutiloculata，
曼氏球齿水蚤，有蹄球齿水蚤，
Globorotalia truncatulinoides和Globorotalia tumida），
与测量的周围海水的原位性质（温度，
盐度和δ ~（18）O海水）和化石测试
下伏表层沉积物“重要影响”，如共生体活动和
试验生长导致δ 18 O不平衡，
周围海水和大量散布的有孔虫
Mg闪烁Ca.总的来说，海洋温度是最突出的
环境对δ 18方解石的影响，
Mg闪烁Ca.重同位素18 O在
混合层下的活标本和化石测试显然
与原位温度降低和配子发生钙化有关。
基于Mg ScinCa的
G. sacculifer表明，
加勒比海各站早春（3月）和当年晚些时候的海底
(May)在佛罗里达海峡，与各自的混合层有关
温度为26摄氏度。值得注意的是，G. sacculifer
揭示了有孔虫衍生之间的弱正线性关系
海水δ 18 O估算值和现场实测值
δ 18 O海水和盐度。我们的研究结果证实，
现有δ 18 O和Mg闪烁的适用性
重建过去海洋温度的校准，
δ 18 O海水反映盐度，
活有孔虫和化石有孔虫的代用数据令人信服地一致，
和现场环境参数。大的生命影响和季节性
然而，需要考虑不同的代理信号。
Abstract. Past ocean temperatures and salinities can be approximated from
combined stable oxygen isotopes (δ18O) and
Mg ∕ Ca measurements in fossil foraminiferal tests with
varying success. To further refine this approach, we collected living
planktic foraminifers by net sampling and pumping of sea surface water from
the Caribbean Sea, the eastern Gulf of Mexico and the Florida Straits. Analyses
of δ18O and Mg ∕ Ca in eight living planktic
species (Globigerinoides sacculifer, Orbulina universa,
Neogloboquadrina dutertrei, Pulleniatina obliquiloculata,
Globorotalia menardii, Globorotalia ungulata,
Globorotalia truncatulinoides and Globorotalia tumida) were
compared to measured in situ properties of the ambient seawater (temperature,
salinity and δ18Oseawater) and fossil tests of
underlying surface sediments. “Vital effects” such as symbiont activity and
test growth cause δ18O disequilibria with respect to the
ambient seawater and a large scatter in foraminiferal
Mg ∕ Ca. Overall, ocean temperature is the most prominent
environmental influence on δ18Ocalcite and
Mg ∕ Ca. Enrichment of the heavier 18O isotope in
living specimens below the mixed layer and in fossil tests is clearly
related to lowered in situ temperatures and gametogenic calcification.
Mg ∕ Ca-based temperature estimates of
G. sacculifer indicate seasonal maximum accumulation rates on the
seafloor in early spring (March) at Caribbean stations and later in the year
(May) in the Florida Straits, related to the respective mixed layer
temperatures of ∼26 ∘C. Notably, G. sacculifer
reveals a weak positive linear relationship between foraminiferal derived
δ18Oseawater estimates and both measured in situ
δ18Oseawater and salinity. Our results affirm the
applicability of existing δ18O and Mg ∕ Ca
calibrations for the reconstruction of past ocean temperatures and
δ18Oseawater reflecting salinity due to the
convincing accordance of proxy data in both living and fossil foraminifers,
and in situ environmental parameters. Large vital effects and seasonally
varying proxy signals, however, need to be taken into account.
影响因子：
16.6
作者：
Fehrenbacher JS;Russell AD;Davis CV;Gagnon AC;Spero HJ;Cliff JB;Zhu Z;Martin P
通讯作者：
Martin P
影响因子：
3.5
作者：
Greaves, M.;Caillon, N.;Wilson, P. A.
通讯作者：
Wilson, P. A.
影响因子：
1.9
作者：
Birch, Heather;Coxall, Helen K.;O'Regan, Matthew
通讯作者：
O'Regan, Matthew