Coral calcifying fluid aragonite saturation states derived from Raman spectroscopy
Coral calcifying fluid aragonite saturation states derived from Raman spectroscopy
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DOI：
10.5194/bg-14-5253-2017
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发表时间：
2017-11-24
期刊：
影响因子：
4.9
通讯作者：
McCulloch, Malcolm T.
中科院分区：
文献类型：
--
作者：
DeCarlo, Thomas M.;D'Olivo, Juan P.;McCulloch, Malcolm T.
量化珊瑚钙化液中文石（Omega（Ar））的饱和状态对于了解珊瑚的生物矿化过程和对包括海洋酸化在内的环境变化的敏感性至关重要。显微镜、微探针和同位素地球化学的最新进展使得能够确定钙化流体的pH和[CO 32-]，但直接量化Omega（Ar）（其中Omega（Ar）D [CO 32-][Ca 2 +]/K-sp）已被证明是难以实现的。在这里，我们测试一种新的技术，用于推导欧米茄（Ar）的基础上拉曼光谱。首先，我们分析了非生物成因的文石晶体下的范围内的Omega（Ar）从10到34沉淀，我们发现一个强烈的依赖性的拉曼峰宽Omega（Ar）没有显着的影响，包括pH值，镁/钙分区，和温度的其他因素。验证我们的珊瑚拉曼技术是困难的，因为目前没有直接测量钙化液欧米茄（Ar）可供比较。然而，拉曼分析的国际珊瑚标准JCp-1产生欧米茄（Ar）的12.3 +/- 0.3，我们证明是一致的公布的骨骼镁/钙，锶/钙，B/钙，δ B-11，和δ Ca-44数据。拉曼测量是快速的（
Quantifying the saturation state of aragonite (Omega(Ar)) within the calcifying fluid of corals is critical for understanding their biomineralization process and sensitivity to environmental changes including ocean acidification. Recent advances in microscopy, microprobes, and isotope geochemistry enable the determination of calcifying fluid pH and [CO32-], but direct quantification of Omega(Ar) (where Omega(Ar) D [CO32-][Ca2+]/K-sp) has proved elusive. Here we test a new technique for deriving Omega(Ar) based on Raman spectroscopy. First, we analysed abiogenic aragonite crystals precipitated under a range of Omega(Ar) from 10 to 34, and we found a strong dependence of Raman peak width on Omega(Ar) with no significant effects of other factors including pH, Mg/Ca partitioning, and temperature. Validation of our Raman technique for corals is difficult because there are presently no direct measurements of calcifying fluid Omega(Ar) available for comparison. However, Raman analysis of the international coral standard JCp-1 produced Omega(Ar) of 12.3 +/- 0.3, which we demonstrate is consistent with published skeletal Mg/Ca, Sr/Ca, B/Ca, delta B-11, and delta Ca-44 data. Raman measurements are rapid (