Strontium/lithium ratio in aragonitic shells of Cerastoderma edule (Bivalvia) - A new potential temperature proxy for brackish environments
Strontium/lithium ratio in aragonitic shells of Cerastoderma edule (Bivalvia) - A new potential temperature proxy for brackish environments
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DOI：
10.1016/j.chemgeo.2015.10.030
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发表时间：
2015-12-06
期刊：
影响因子：
3.9
通讯作者：
Mertz-Kraus, Regina
中科院分区：
文献类型：
--
作者：
Fuellenbach, Christoph S.;Schoene, Bernd R.;Mertz-Kraus, Regina
从双壳类软体动物的贝壳中定量重建水温仍然是一项非常具有挑战性的任务。例如，在高度多变的环境中，如潮间带，只有在已知生长期间的三角洲O-18(水)特征的情况下，贝壳氧同位素值才能提供可靠的温度估计。此外，微量元素与钙的比值，如锶/钙或镁/钙，往往不能作为可靠的古温度计，因为它们与双壳类贝壳的结合是众所周知的，受到强烈的生物控制。在这里，我们提出了一个潜在的新的温度代理，它是基于潮间带双壳类生物Cerastoderma edulate的锶/锂壳比。高达81%的锶/锂壳层的变异性是由水温来解释的。文中提出，通过将Sr/Ca归一化为Li/Ca，可在很大程度上消除文石壳层中掺入锶和锂的重要影响。生长速度并不控制锶或锂进入壳层的过程。通过使用这种新的替代物，可以在+/-1.5摄氏度的不确定度下估计水温。未来需要进行研究，以测试在其他双壳类物种和其他环境中，锶/锂贝壳是否也可以作为可靠的温度替代物。(C)2015爱思唯尔B.V.保留所有权利。
Quantitative reconstruction of water temperature from shells of bivalve mollusks is still a very challenging task. For example, in highly variable environments such as intertidal zones, shell oxygen isotope values can only provide reliable temperature estimates if the delta O-18(water) signature during the time of growth is known. Furthermore, trace element-to-calcium ratios such as Sr/Ca or Mg/Ca often do not serve as reliable paleothermometers, because their incorporation into bivalve shells is known to be strongly biologically controlled. Here, we present a potential novel temperature proxy which is based on the Sr/Li-shell ratio of the intertidal bivalve Cerastoderma edule. Up to 81% of the variability in Sr/Li-shell is mathematically explained by water temperature. It is suggested that vital effects on the incorporation of Sr and Li into the aragonitic shells are largely eliminated by normalizing Sr/Ca to Li/Ca. Growth rate does not control the incorporation of Sr or Li into the shell of C. edule. By using this new proxy, it was possible to estimate water temperature from C. edule with an uncertainty of +/- 1.5 degrees C. Future studies are required to test if Sr/Li-shell also serves as a reliable temperature proxy in other bivalve species and in other environments. (C) 2015 Elsevier B.V. All rights reserved.