Constraints on ore vectoring from geochemical fingerprints of porphyry style pyrite

The sulfur isotope compositions of three generations of pyrite originated from skarns, stockwork, and late-stage, post-hydrothermal veins from three various zones of the porphyry style Myszków Mo-Cu-W deposit (center, circum-deposit, and periphery) were investigated as a proxy for the mineralized core of porphyry system. Overall, the mode of δ³⁴S_pyrite decreases with time, from skarn- through main- up to late-stage of ore mineralization (with average values of + 6.13, + 5.65, and + 3.34 ‰, respectively). The gradual decrease in δ³⁴S values outwards from the deposit core (av. 3.95 ‰), through circum-deposit (av. + 3.40‰) to distal zone (av. + 3.05 ‰) was detected only for late-stage pyrite. Both the temporal and lateral zonation of δ³⁴S_pyrite could be explained by the progressive temperature decrease of the mineralized system and the mixing of ore-forming solutions with more dilute meteoric waters. The trace geochemistry of late-stage pyrite shows relatively constant values of Tl (from 0.13 to 0.14 ppm), Ti (9.10-10.30 ppm), Cr (9.94-12.37 ppm), and Mn (6.94-7.59 ppm) regardless of the zone of the Myszków Mo-Cu-W deposit. While, As (24.96-184.80 ppm), Sb (0.50-13.52 ppm), Bi (0.57-1.54 ppm) in pyrite and Sb/Te (0.06-1.62), Co/Bi (3.32-34.23), and Ag/Ni (0.006-0.140) increase with the proximity to the ore, contrary to Ag/Co which rises towards the periphery of the deposit (0.04-0.13). Ultimately, these results indicate that sulfur isotope data supported by trace geochemistry of late-stage pyrite can be potentially used as vectoring proxies to predict the likely direction to the mineralized center of a porphyry system.