The Influence of Fluid-Exsolving Depth on Mineralization Quality: Evidence from Biotite and Zircon Mineralogy and Fluid Inclusions from the 460 Gaodi Porphyry Mo-Cu Deposit, NE China

The recently discovered 460 Gaodi porphyry Mo-Cu deposit is a sub-economic characterized by low grades, dispersed mineralization, and separated Mo- Cu-ore bodies. This study aims to elucidate the factors underlying this type of mineralization. Electron-microprobe analyses biotite from ore-related granite yielded Ti-in-biotite crystallization temperatures 677–734 °C (an average 719 °C) phenocryst depths 6.0 12.9 km. LA-ICP-MS zircons same sample revealed zircon Ce4+/Ce3+ ratios 299.7 elevated lg(ƒO2) ratios, with an ΔFMQ +6.6 ± 1.9. These discoveries suggest that magma responsible for ore formation boasts high degree oxidation, yet also possesses chamber located at significant depth within upper crust. implies extensive exsolving fluids. Furthermore, our microthermometry analysis fluid inclusions reveals portion experiences considerable conductive cooling as it ascends along conduit, owing exsolution. process results in fluids remaining liquid-only region without undergoing boiling, which conducive enrichment metals. We emphasize fact fluid-exsolving plays critical role determining metal grades economic value regulating P-T evolution path