Formation of the Chalukou High Fluorine-Type Mo (–Zn–Pb) Deposit, NE China: Constraints from Fluorite and Sphalerite Rare Earth Elements and Sr–Nd Isotope Compositions

Fluorite is a widespread mineral in porphyry and hydrothermal vein Mo-polymetallic deposits. Here, fluorite utilised as probe to trace the fluid source reveal evolution process Chalukou giant Mo (Pb–Zn) deposit, Northeast China, which characterised early later vein-style Zn–Pb mineralisation. A detailed rare earth element (REE) Sr–Nd isotope study of combined with Sr isotopes sphalerite conducted for deposit. The chondrite-normalised REE patterns fluorites from molybdenite veins show light (LREE)-enriched patterns, negative Eu anomalies (δEu = 0.60) weakly Y (Y/Y* 0.72). associated exhibit (REE)-flat 0.65 0.99) positive 1.37 3.08). In addition, during progression mineralisation, total concentration REEs decreases 839 ppm 53.7 ppm, Y/Ho ratios increase 22.1 92.5. These features may be explained by different mobilities complexes migration. are considered inherited fluids. All initial 87Sr/86Sr between those ore-forming porphyries wall rocks (rhyolite), ranging 0.706942 0.707386 varying 0.705221 0.710417. majority εNd(t) values −6.4 −3.6 also located exhibited rhyolite, whereas three −0.26 0.36 close porphyries. isotopic indicate that Sr-Nd derived disturbed fluid–rock reactions. Together two-stage mixing model, we suggest sources interactions (syn-ore intrusions strata) finally influence fluids, recorded sphalerite.