The Giant Chalukou Porphyry Mo Deposit, Northeast China: The Product of a Short-Lived, High Flux Mineralizing Event

Abstract Whether giant porphyry ore deposits are the products of single, short-lived magmatic-hydrothermal events or multiple over a prolonged interval is topic considerable debate. Previous studies, however, have all been devoted to Cu and Cu-Mo deposits. In this paper, we report high-precision isotope dilution-negative-thermal ionization mass spectrometric (ID-N-TIMS) molybdenite Re-Os ages for newly discovered, world-class Chalukou Mo deposit (reserves 2.46 Mt @ 0.087 wt % Mo) in NE China. Samples were selected based on careful evaluation relative timing different vein types (i.e., A, B, D veins), thereby ensuring that suite samples analyzed could be used reliably determine age duration mineralization. The geochronology reveals hydrothermal activity at involved two spanning an 6.92 ± 0.16 m.y. first event (153.96 0.08/0.63/0.79 Ma, ID-N-TIMS age) was associated with emplacement granite dated 152.1 2.2 Ma (zircon laser ablation-inductively coupled plasma-microscopic [LA-ICP-MS] U-Pb ages), led only minor mineralization, accounting <10% overall budget. bulk (>90%) deposited less than 650 kyr, between 147.67 0.10/0.60/0.76 147.04 0.12/0.72/0.86 (molybdenite coincident fine-grained 148.1 2.6 LA-ICP-MS ages). determinations presented here show, contrary finding number studies systems, primarily formed (<650 kyr) event, suggesting may also case other