Research progress on zircon from pegmatites and insights into rare-metal mineralization-a review

With increasing global demand for rare metals rare-metal pegmatites have attracted much attention due to their widespread distribution and great metallogenic potentials. Zircon as an important accessory mineral in pegmatites is important for the understanding of pegmatite genesis regarding the ore-forming source material, fluid properties/evolution, and rare-metal enrichment mechanism. This paper summarizes the latest research progress on pegmatite-hosted zircons and insights into rare-metal mineralization in pegmatites. Recent studies show that pegmatite-hosted zircons have multiple origins and often undergo hydrothermal transformation, which result in complex zircon age spectrum, where rare-metal mineralization is related to older zircons. Geochemical anomalies of trace elements in zircons can indicate complex raremetal mineralization in pegmatites, constrain magmatic evolution process and reveal ore-forming fluid properties. The REE tetrad effect is a special mode of rare-earth distribution in magmatic rocks. Such distribution mode also exist for pegmatite-hosted zircons revealing complex melt-fluid evolution. Hf-O isotopic composition of pegmatite-hosted zircons is highly variable where Hf isotopes are a good tracer for pegmatite source areas and oxygen for fluids. Pegmatite-hosted zircon is rich in fluid and mineral inclusions, thus future key research should focus on using fluid inclusion temperature measurement and composition analysis to delineate the magmatic evolution stages, using high-U zircons to track the source of U-rich fluids, and using zircon Li/Zr isotopes to reveal the ore-forming processes. © 2023 Science Frontiers editorial department. All rights reserved.