Crystallographic and chemical signatures in coral skeletal aragonite
Crystallographic and chemical signatures in coral skeletal aragonite
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DOI：
10.1007/s00338-021-02198-4
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发表时间：
2021-11-29
期刊：
影响因子：
3.5
通讯作者：
Hansel, Colleen M.
中科院分区：
文献类型：
--
作者：
Farfan, Gabriela A.;Apprill, Amy;Hansel, Colleen M.
珊瑚成核并生长文石晶体，将它们组织成错综复杂的骨骼结构，最终形成世界上的珊瑚礁。结晶学和化学对这些骨骼构件的材料性质有深远的影响，但我们对珊瑚文石在原子尺度上的认识仍然存在空白。在来自不同环境的各种浅水和深海珊瑚中，珊瑚文石彼此非常相似，证实了珊瑚相对于周围海水对钙化空间的碳酸盐化学起着控制作用。珊瑚文石结构的细微差别与微量元素化学和文石饱和状态关系最为密切，表明离子强度和微量元素化学是控制文石结构的主要因素，生长速率起次要作用。我们还展示了在类似珊瑚钙化流体的条件下，珊瑚文石与从海水中沉淀的合成非生物文石类似物在结晶学上是如何难以区分的。相比之下，珊瑚文石不同于地质形成的文石，文石是从淡水溶液中沉淀出来的合成文石，以及软体动物文石。结晶学特征在理解珊瑚文石的材料性质和预测珊瑚礁在快速变化的海洋中的持久性方面具有未来的应用。
Corals nucleate and grow aragonite crystals, organizing them into intricate skeletal structures that ultimately build the world's coral reefs. Crystallography and chemistry have profound influence on the material properties of these skeletal building blocks, yet gaps remain in our knowledge about coral aragonite on the atomic scale. Across a broad diversity of shallow-water and deep-sea scleractinian corals from vastly different environments, coral aragonites are remarkably similar to one another, confirming that corals exert control on the carbonate chemistry of the calcifying space relative to the surrounding seawater. Nuances in coral aragonite structures relate most closely to trace element chemistry and aragonite saturation state, suggesting the primary controls on aragonite structure are ionic strength and trace element chemistry, with growth rate playing a secondary role. We also show how coral aragonites are crystallographically indistinguishable from synthetic abiogenic aragonite analogs precipitated from seawater under conditions mimicking coral calcifying fluid. In contrast, coral aragonites are distinct from geologically formed aragonites, a synthetic aragonite precipitated from a freshwater solution, and mollusk aragonites. Crystallographic signatures have future applications in understanding the material properties of coral aragonite and predicting the persistence of coral reefs in a rapidly changing ocean.