Fathoming sequestration and enrichment of rare-earth elements in marine deposits

Rare earth elements (REE) are essential to modern life, yet we know little about how they concentrate at Earth’s surface, especially on the seafloor, which holds vast reserves. The underlying mechanistic pathways leading to some of the highest elemental enrichments in supergene ores is a long-standing geochemical and crystallochemical enigma. To advance the field, we propose to determine how light (LREE = Ce-Nd), medium (MREE = Gd-Dy), and heavy (HREE = Er-Yb) REE are incorporated in apatite-rich sediments at the atomic scale. The structural results will inform atomistic calculations that will be employed to model the thermodynamics and kinetics of the chemical reactions at the seawater-apatite interface. The Long Term Proposal is supported by an ERC Advanced Grant awarded to the ESRF and the Ecole Normale Supérieure of Lyon.

稀土元素（Rare earth elements, REE）对现代社会至关重要，但我们对其在地球表面的富集机制仍知之甚少，尤其是在坐拥海量储量的海底。导致表生矿床出现极高元素富集的内在机制路径，长期以来都是地球化学与晶体化学领域的未解谜题。为推动该领域发展，本研究拟从原子尺度解析轻稀土元素（LREE = Ce-Nd）、中稀土元素（MREE = Gd-Dy）与重稀土元素（HREE = Er-Yb）在富磷灰石（apatite）沉积物中的赋存方式。该结构研究结果将为原子尺度计算提供依据，用于模拟海水-磷灰石界面处化学反应的热力学与动力学过程。本长期研究项目由授予欧洲同步辐射装置（ESRF）与里昂高等师范学院（Ecole Normale Supérieure of Lyon）的欧洲研究委员会高级研究基金（ERC Advanced Grant）资助。