【科技日报】新研究揭示稀土成矿关键因素

Core Insights - The research team from the Guangzhou Institute of Geochemistry has identified the key factor controlling the extraordinary accumulation of rare earth elements (REEs) in carbonatite magma, which is the depth of intrusion [1][2] - The findings were published in the international journal "Nature Communications" on February 3, 2026, highlighting the significance of this research in understanding the distribution of carbonatite-type rare earth deposits globally [1][2] Group 1: Research Findings - The study reveals that less than 10% of carbonatite bodies form economically viable rare earth deposits, despite over half of the global rare earth reserves being sourced from carbonatites [1] - High-temperature and high-pressure experiments simulated the cooling crystallization process of carbonatite magma at depths of 6 to 20 kilometers, showing two distinct evolutionary paths based on pressure [1][2] Group 2: Mechanisms of REE Accumulation - At depths shallower than 10 kilometers (approximately 0.3 GPa), early crystallization of apatite occurs, which traps REEs in its structure, preventing their migration and accumulation [1][2] - In contrast, at depths greater than 10 kilometers, olivine crystallizes first, consuming silicon and preventing apatite from forming a "cage" for REEs, allowing for higher solubility of REEs in saline melts, which leads to the formation of economically valuable minerals [2] Group 3: Implications for Exploration - The research establishes a complete causal chain of "pressure—mineral crystallization sequence—melt properties—REE enrichment," enhancing the understanding of the mechanisms behind REE accumulation [2] - This study provides new insights for the exploration of carbonatite-type rare earth deposits, indicating that world-class deposits, such as those in China, are typically found at depths greater than 10 kilometers [2]