TRACE ELEMENT HETEROGENEITY ACROSS INDIVIDUAL PLANKTIC FORAMINIFERA FROM THE MODERN CARIACO BASIN
TRACE ELEMENT HETEROGENEITY ACROSS INDIVIDUAL PLANKTIC FORAMINIFERA FROM THE MODERN CARIACO BASIN
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DOI：
10.2113/gsjfr.50.2.204
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发表时间：
2020-04-01
影响因子：
1.1
通讯作者：
Thunell, Robert C.
中科院分区：
文献类型：
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作者：
Davis, Catherine, V;Fehrenbacher, Jennifer S.;Thunell, Robert C.
浮游有孔虫贝壳的微量元素组成既受环境因素的影响，又受生物因素(生命效应)的影响。随着个别有孔虫贝壳中的微量元素越来越多地被用作古海洋学工具，了解微量元素比率在个体之间、物种之间以及对高频环境变异性的反应是至关重要的。在这里，我们提供了三年的浮游生物记录(2010-2012年)单个贝壳微量元素(镁、锶、钡和锰)与钙的比值在浮游生物物种Globigerina ruber(粉红色)、Orbulina Univera和Globorotalia menardii在Cariaco盆地上部100米采集。浮游生物拖网与水柱化学和水文学的现场测量配对。当根据单一物种的镁/钙平均值计算物种特定温度关系时，镁/钙比反映了所有三个物种的不同钙化温度。然而，个别壳层的镁/钙经常导致不切实际的温带估计。这四个物种的锶/钙比值相对恒定。锰/钙和巴/钙的比值在门氏狸殖吸虫中最高，不能反映开放水域的元素浓度。在上升流条件下，所有物种的Mn/Ca比值都较高，在上升流期间采集的加州边缘的新球藻贝壳中也表现出类似的趋势。这表明壳层Mn/Ca升高可能是深部水团上升流的示踪剂。我们的结果强调了生活在有限深度栖息地的物种之间和物种内部存在着很大程度的微量元素变异性，以及生物学、钙化环境和物理混合在调节微量元素地球化学如何反映表层海洋环境变异性方面的作用。
The trace element composition of planktic foraminifera shells is influenced by both environmental and biological factors ('vital effects'). As trace elements in individual foraminifera shells are increasingly used as paleoceanographic tools, understanding how trace element ratios vary between individuals, among species, and in response to high frequency environmental variability is of critical importance. Here, we present a three-year plankton tow record (2010-2012) of individual shell trace element (Mg, Sr, Ba, and Mn) to Ca ratios in the planktic species Globigerina ruber (pink), Orbulina universa, and Globorotalia menardii collected throughout the upper 100 m of Cariaco Basin. Plankton tows were paired with in situ measurements of water column chemistry and hydrography. The Mg/Ca ratio reflects different calcification temperatures in all three species when calculated using species-specific temperature relationships from single-species averages of Mg/Ca. However, individual shell Mg/Ca often results in unrealistic temperate estimates. The Sr/Ca ratios are relatively constant among the four species. Ratios of Mn/Ca and Ba/Ca are highest in G. menardii and are not reflective of elemental concentrations in open waters. The Mn/Ca ratio is elevated in all species during upwelling conditions, and a similar trend is demonstrated in Neogloboquadrina incompta shells from the California margin collected during upwelling periods. Together this suggests that elevated shell Mn/Ca may act as a tracer for upwelling of deeper water masses. Our results emphasize the large degree of trace element variability present among and within species living within a limited depth habitat and the roles of biology, calcification environment, and physical mixing in mediating how trace element geochemistry reflects environmental variability in the surface ocean.