Trace element geochemistry of sphalerite and chalcopyrite in arc-hosted VMS deposits

Trace element compositions of sphalerite and chalcopyrite have been investigated for four arc-hosted Cretaceous VMS deposits (María Teresa, Perubar, Palma in Peru, Cerro de Maimón the Dominican Republic) using laser ablation inductively-coupled plasma mass spectrometry. In sphalerite, Fe, Mn, Cd, Hg, Ag, Sb, Se, In, Ge, Ga are lattice-bound, whereas Sn, Tl, Bi, Pb occur at least partly as mineral microinclusions. Significant variations contents minor trace elements observed grains from individual deposits. A strong negative correlation between Fe (Inter-Quartile Range [IQR] 44,009–18,168 ppm) Zn indicates a dominant Fe2+ ? Zn2+ simple isovalent substitution. Regarding potential high-tech by-products, (IQR 42–1.6 ppm, up to 415 31–5.9 96 studied normally much higher than those Ge 0.85–0.16 9.3 ppm). Correlation trends suggest Cu+ + In3+ 2Zn2+, Ga3+ more complex substitution mechanisms involving combinations monovalent (Cu+, Ag+), divalent (Ge2+?), trivalent (In3+, Ga3+, [Sn3+?]), quadrivalent (Ge4+, Sn4+) cations. As chalcopyrite, Zn, Ga, interpreted be Mo, Au, Pb, Bi probably Relative is depleted 28–8.4 49 8.3–2.9 24 enriched 5.9–0.70 80 Of other elements, 426–190 most highly concentrated followed by Ag 136–23 ppm), Se 64–22 Sn 53–1.3 Cd 12–6.0 General positive varied coupled Cu with fluctuating valences due covalent bonding. Trace-element distribution patterns were zone-refined Sofía-D massive sulfide body María Teresa deposit, which comprises lower portion pyrite sheathed upward zones (Cu zone), (Zn zone) galena ± fahlore barite (Pb – zone). Bottom top body, records progressive depletion Cu, enrichment Ge. This pattern agrees increasing crystallization temperatures and/or volatile magmatic influx towards mineralization. Distribution rather uneven except sustained basal body. The fact that such preserved spite extensive recrystallization during thermal metamorphism parts mineralization suggests i) closed metamorphic system ii) interdiffusion was prominently local. Accordingly, we propose lattice-bound described this article can help determine polarity bodies districts metamorphosed tectonized terranes.