中国地质科学院侯增谦、朱鑫祥等提出，次大陆岩石圈地幔中大量稀土元素的储存是由底辟作用而非熔融作用引起的。这一研究成果发表在2023年11月28日出版的国际学术期刊《地质学》上。

研究人员在 3-4 GPa 和 800-1000℃ 的天然富稀土元素的海洋沉积物进行了高压实验，以限制俯冲期间的相关系、沉积物熔融行为和稀土元素的迁移。实验结果表明，重结晶形成榴辉岩样组合，只有在 1000°C、4 GPa的实验条件下才发生熔融。无论熔融行为如何，稀土元素都是难熔的，主要以磷灰石承载。

浮力计算表明，大多数榴辉岩样残留物会形成固态底辟，上升到次大陆岩石圈地幔，形成稀土滋养的沉积物。这种通量可能需要在俯冲过程中，迁移大量的稀土元素，这一过程是经济级矿化的基础。

据介绍，稀土元素(REEs)是现代技术必不可少的金属。最近的研究表明，以前由俯冲的海洋沉积物滋养的(SCLM)的重熔，导致含稀土岩石的形成。然而，富稀土元素的沉积物从俯冲板块向上覆地幔楔的迁移机制尚不清楚。

附：英文原文

Title: Massive rare earth element storage in sub-continental lithospheric mantle initiated by diapirism, not by melting

Author: XinXiang Zhu, Yan Liu, Zengqian Hou

Issue&Volume: 2023-11-28

Abstract: Rare earth elements (REEs) are essential metals for modern technologies. Recent studies suggest that subcontinental lithospheric mantle (SCLM) remelting, previously fertilized by subducted marine sediments, leads to formation of REE-bearing rocks. However, the transfer mechanism of REE-rich sediments from the subducted slab to the overlying mantle wedge is unclear. We present high-pressure experiments on natural REE-rich marine sediments at 3–4 GPa and 800–1000 °C to constrain the phase relations, sediment melting behavior, and REE migration during subduction. Our results show recrystallization into an eclogite-like assemblage, with melting only occurring at 4 GPa, 1000 °C, experiments. Regardless of melting behavior, REE are refractory and mostly hosted by apatite. Buoyancy calculations suggest that most of the eclogite-like residues would form solid-state diapirs, ascending to the SCLM, resulting in the REE-fertilized source. Such flux may be required for substantial REE transport during subduction, as a foundation for economic-grade mineralization.

DOI: 10.1130/G51102.1

Source: https://pubs.geoscienceworld.org/gsa/geology/article/doi/10.1130/G51102.1/629912/Massive-rare-earth-element-storage-in-sub