High precision Re-Os isotopic dating of molybdenites

Molybdenite is an ideal mineral for Re-Os isotopic dating, and its Re-Os isotopic systematics are widely employed to constrain the timing of hydrothermal metal mineralization. However, high-precision Re-Os isotopic dating (precision <1‰) remains a global challenge, as most published molybdenite Re-Os isotopic ages exhibit dating precisions far above 3‰, with only scarce data falling between 1‰ and 3‰, and very few cases achieving <1‰, which severely hinders the understanding of metallogenic regularity and the optimization of mineral exploration targets. In this study, the chemical separation and instrumental analysis methods for molybdenite Re-Os isotopic dating have been optimized. Using this improved isotopic dilution method, we analyzed the Huanglongpu molybdenite (a widely utilized molybdenite reference material) and molybdenite samples from four representative metal deposits. Each individual analysis achieved a dating precision of <1‰, with the best dating precision reaching 0.13‰. In addition, the weighted mean age precision of molybdenite from the Baishiding polymetallic deposit also reached 1‰. This study reveals that the molybdenite Re-Os isotopic dating can indeed serve as another reliable high-precision dating tool, complementing the well-established U-Pb dating method for deciphering Earth's geological timescale.