Trace and major element incorporation into amorphous calcium carbonate (ACC) precipitated from seawater
Trace and major element incorporation into amorphous calcium carbonate (ACC) precipitated from seawater
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DOI：
10.1016/j.gca.2020.08.034
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发表时间：
2020-12-01
影响因子：
5
通讯作者：
Allison, Nicola
中科院分区：
文献类型：
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作者：
Evans, David;Gray, William R.;Allison, Nicola
无定形碳酸钙（ACC）已被确定或推断存在于许多海洋生物中，这些生物产生广泛用作地球化学档案的生物矿物（例如有孔虫，软体动物，棘皮动物）。然而，很少有人知道微量元素纳入ACC，因此，它是不明白如何通过ACC前体降水可能会影响气候代理和生物矿化模型的保真度建立在这些海洋钙化的骨骼地球化学。为了解决这个问题，我们调查了锂，B，钠，镁，锰，锶，钡，和U的注册成立到无机无定形碳酸钙镁碳酸盐沉淀从海水中各种不同的碳酸盐化学，镁/钙比，并在天冬氨酸和谷氨酸的存在下，两个最常见的晶内氨基酸中发现的有孔虫和珊瑚。ACC是高度富集在大多数这些微量元素相对于结晶碳酸盐，但在某些方面的影响因素的微量元素分区相似。例如，ACC B/Ca对碳酸盐体系敏感，而Mg/Ca和Sr/Ca在很大程度上是海水中它们各自比例的函数。在一般情况下，我们发现，其他微量元素的分布系数的方差可以解释的海水碳酸盐化学和海水或ACC镁/钙比的一些组合。(C)2020爱思唯尔有限公司版权所有。
Amorphous calcium carbonate (ACC) has been identified or inferred to exist in many groups of marine organisms that produce biominerals widely used as geochemical archives (e.g. foraminifera, molluscs, echinoderms). However, little is known about trace element incorporation into ACC, and thus it is not understood how precipitation through an ACC precursor might impact the fidelity of climate proxies and biomineralisation models built on the skeletal geochemistry of these marine calcifiers. To address this, we investigated the incorporation of Li, B, Na, Mg, Mn, Sr, Ba, and U into inorganic amorphous calcium magnesium carbonates precipitated from seawater under a variety of different carbonate chemistries, Mg/Ca ratios, and in the presence of aspartic and glutamic acid, two of the most common intracrystalline amino acids found in foraminifera and corals. ACC is highly enriched in most of these trace elements relative to the crystalline carbonates yet similar in some respects in terms of the factors influencing trace element partitioning. For example, ACC B/Ca is sensitive to the carbonate system, whilst Mg/Ca and Sr/Ca are largely a function of their respective ratio in seawater. In general, we find that most of the variance in the distribution coefficients of the other trace elements can be explained by some combination of the seawater carbonate chemistry and the seawater or ACC Mg/Ca ratio. (C) 2020 Elsevier Ltd. All rights reserved.