Multi-stage metasomatic Zr mineralization in the world-class Baerzhe rare earth element Nb-Zr-Be deposit, China

Abstract

Magmatic and metasomatic zircon occurs in many alkaline igneous rocks and both are potential economic reservoirs of Zr, and in some places, rare-earth elements. The Baerzhe deposit in China is an example of a system where both types of zircon occur. Previous studies recognized deuteric and variably altered magmatic zircon in a transsolvus miaskitic granite, as well as four types of metasomatic zircon in a transsolvus agpaitic granite. In this study, the relationships among, and origins of, zircon and how these relate to models for rare-metal mineralization are assessed. In-situ back-scattered electron (BSE) and cathodoluminescence (CL) imaging, Raman spectroscopy (including mapping), and chemistry of zircon from the agpaitic granite were conducted, combined with evaluation of published data on zircon from Baerzhe. Their textural, spectroscopic, and chemical characteristics suggest that the four types of metasomatic zircon in the agpaitic granite were not subjected to metamictization or intense alteration, with traceelement accommodation largely following a xenotime substitution mechanism. The most abundant type of metasomatic zircon in the agpaitic granite occurs in zircon-quartz pseudomorphs and exhibits comparable CL, Raman spectral, and chemical features to rare zircon

Water Recycling in the Deep Earth: Insights From Integrated μ‐XRF, THz‐TDS Spectroscopy, TG, and DCS of High‐Pressure Granulite

“…As the phase transformation of α‐β quartz occurs at a temperature range of ca. 574–890°C, quartz in the studied high‐pressure mafic granulite might have been stabilized at a temperature range of <850–1,000°C (Figure 8), indicating phase transformation and water release during the subduction dehydration process (Li & Chou, 2022; Mechie et al., 2004; Y. Wang et al., 2021; Wu et al., 2023). Therefore, quartz from the rutile‐bearing garnet amphibolite might contain only minor contents of water.…”

Apatite U-Pb Dating and Composition Constraints for Magmatic–Hydrothermal Evolution in the Giant Renli Nb-Ta Deposit, South China

“…Apatite is an important accessory mineral in various magmatic rocks, and Ca 2+ can be occupied by a number of cations, such as Na + , Fe 2+ , Mn 2+ , Sr 2+ , rare earth elements (REE 2+ / 3+ ), and Y 3+ [4,[53][54][55][56]. The trace elements in apatite depend on the characteristics of the host rock, so the geochemical characteristics of apatite can be used to interpret the mineralogical and geological conditions [57][58][59][60][61][62][63]. Large quantities of elements (Ce, Eu, and Mn) enter apatite, and due to the variable oxidation of these elements, their anomalies in apatite can be used to indicate the redox state of magma [47,64,65].…”

Partial Melting of Lithospheric Mantle and Formation of the Early Cretaceous Alkaline Rocks in the Guandimiao REE Deposit, Luxi Terrane, Eastern China

“…The North China Block (NCB) has undergone a series of geodynamic events since the Mesozoic, including the collision of the NCB and Yangtze plate and subduction of the Izanagi plate, and compression-to-extension tectonic regime transformation, resulting in the thinning of the lithosphere associated with widespread magmatism and ore formation [11][12][13][14][15] (Figure 1A,B). The Luxi Terrane intersects to the east with the Liaocheng-Lankao fault zone, to the west with the Yishu fault zone, to the south with the Fengpei fault and to the north with the Qihe-Guangrao fault, forming an approximate parallelogram [6] (Figure 1C).…”