匈牙利罗兰大学E.A.A. Mororó的团队最新的研究，探明了与碳酸盐岩系统流体相关的稀土元素迁移和矿化作用。该项研究成果发表在2024年1月19日出版的《地质学》上。

研究人员通过研究Oldoinyo Lengai火山的次生石英流体包裹体，首次对天然碳酸盐岩体系中的流体及其微量元素组成进行了原位表征。通过与不同类型碳酸盐岩系统的流体和熔体数据进行比较，研究人员建立了流体介导的稀土元素运移和矿化模型。

研究发现，碳酸盐岩相关流体富含碱—碳酸盐岩+硫酸盐+氯化物和CO₂，H₂O含量较低，它们是稀土元素(＞1600 ppm)的重要载体。研究人员认为，流体中的CO₂含量对阻止或减缓运移过程中与围岩的相互作用至关重要，流体介导的稀土元素矿化在流体中CO₂分压降低时(即脱气过程中)发生。

据了解，稀土元素是现代技术的关键组成部分，其中一些最大的自然资源矿床与碳酸盐岩系统有关。然而，人们对稀土元素矿化的机制和岩浆流体在碳酸盐岩系统中的作用仍然知之甚少。

附：英文原文

Title: Rare earth element transport and mineralization linked to fluids from carbonatite systems

Author: E.A.A. Mororó, M. Berkesi, Z. Zajacz, T. Guzmics

Issue&Volume: 2024-01-19

Abstract: Rare earth elements are critical constituents for modern technologies, and some of their largest natural resource deposits are related to carbonatite systems. However, the mechanisms leading to rare earth element mineralization and the role of magmatic fluids in carbonatite systems remain poorly understood. Here, we present the first in situ characterization of fluids and their trace-element compositions in natural carbonatite systems by studying secondary quartz-hosted fluid inclusions from Oldoinyo Lengai volcano. By comparing our data to other fluids and melts from various carbonatite systems, we constructed a model for fluid-mediated rare earth element transport and mineralization. We show that carbonatite-related fluids are rich in alkali-carbonate + sulfate + chloride and CO₂, but poor in H₂O, and they can be significant carriers of rare earth elements (>1600 ppm). We argue that fluid CO₂ contents are essential to preclude or slow down the interaction with wall rock during migration and that fluid-mediated rare earth element mineralization occurs when partial pressure of CO₂ decreases in the fluid (i.e., during degassing).

DOI: 10.1130/G51531.1

Source: https://pubs.geoscienceworld.org/gsa/geology/article/doi/10.1130/G51531.1/633418/Rare-earth-element-transport-and-mineralization