Manceau Alain, Gaillot Anne-Claire, Liao Jianlin, Li Yan, Mathon Olivier, Lomachenko Kirill A, Glatzel Pieter, Simionovici Alexandre, Balvay Mélanie, Paul Sophie A L, Koschinsky Andrea, Steinmann Stephan N
European Synchrotron Radiation Facility (ESRF), 38043 Grenoble, France.
ENS de Lyon, CNRS, Laboratoire de Chimie, 69342 Lyon, France.
Commun Earth Environ. 2025;6(1):466. doi: 10.1038/s43247-025-02439-2. Epub 2025 Jun 16.
Deep-sea mud is rich in rare-earth elements, primarily found in fluorapatite, a mineral deposit that forms over hundreds of thousands to millions of years through the accumulation of fish remains. After fish die, biogenic apatite captures rare earth elements from seawater on the seafloor and from pore waters during the diagenesis process. The conventional model for rare earth element enrichment suggests that they are incorporated into the bioapatite crystal structure through solid-state diffusion. However, our data reveal that cerium atoms are instead precipitated within an amorphous layer surrounding bioapatite nanocrystals, as shown by high-energy-resolution X-ray absorption spectroscopy and transmission electron microscopy. Computational simulations further support this finding, predicting that cerium atoms cluster on the surface of fluorapatite. These results suggest that the fluorapatite-water interface plays a crucial role in the enrichment of cerium, as well as other rare earth elements, in marine sediments.
深海泥富含稀土元素，主要存在于氟磷灰石中，氟磷灰石是一种矿床，它是通过鱼类遗骸的积累在数十万至数百万年的时间里形成的。鱼类死后，生物源磷灰石在成岩过程中从海底海水和孔隙水中捕获稀土元素。稀土元素富集的传统模型表明，它们是通过固态扩散纳入生物磷灰石晶体结构的。然而，我们的数据显示，铈原子反而沉淀在生物磷灰石纳米晶体周围的无定形层内，高能分辨率X射线吸收光谱和透射电子显微镜显示了这一点。计算模拟进一步支持了这一发现，预测铈原子聚集在氟磷灰石表面。这些结果表明，氟磷灰石-水界面在海洋沉积物中铈以及其他稀土元素的富集中起着关键作用。
