Ages and Sources of Ore‐Related Porphyries at Y ongping C u– M o Deposit in J iangxi P rovince, S outheast C hina

Whole‐rock geochemistry, zircon U – P b and molybdenite R e– O s geochronology, and S r– N d– H f isotopes analyses were performed on ore‐related dacite porphyry and quartz porphyry at the Y ongping C u– M o deposit in S outheast C hina. The geochemical results show that these porphyry stocks have similar REE patterns, and primitive mantle‐normalized spectra show LILE ‐enrichment ( B a, R b, K ) and HFSE ( T h, N b, T a, T i) depletion. The zircon SHRIMP U – P b geochronologic results show that the ore‐related porphyries were emplaced at 162–156 Ma. Hydrothermal muscovite of the quartz porphyry yields a plateau age of 162.1 ± 1.4 Ma (2σ). Two hydrothermal biotite samples of the dacite porphyry show plateau ages of 164 ± 1.3 and 163.8 ± 1.3 Ma. Two molybdenite samples from quartz+molybdenite veins contained in the quartz porphyry yield R e– O s ages of 156.7 ± 2.8 Ma and 155.7 ± 3.6 Ma. The ages of molybdenite coeval to zircon and biotite and muscovite ages of the porphyries within the errors suggest that the M o mineralization was genetically related to the magmatic emplacement. The whole rocks N d– S r isotopic data obtained from both the dacite and quartz porphyries suggest partial melting of the M eso‐ P roterozoic crust in contribution to the magma process. The zircon H f isotopic data also indicate the crustal component is the dominated during the magma generation.