Deep to Shallow Sulfide Saturation at Nisyros Active Volcano

We report new petrographic and geochemical observations on magmatic sulfides occurring in different enclave types, including hornblende and/or clinopyroxene-rich cumulates, the host lavas, Nisyros (South Aegean volcanic arc). discuss our findings context of pre-existing petrological thermobarometry studies. Our results indicate that become less abundant Cu-richer (Cu median values) with magma differentiation at progressively lower pressure/P-temperature/T-depth conditions. Starting high T-P sulfide-free pillow lavas wehrilitic cumulates still representing a sulfide undersaturated system, passing to T P, deep-forming sulfide-rich hornblende-rich gabbroic enclaves (SiO2 = 53–55 wt.%, 4–5 × 10−5 area %, Cu 260 μg/g) base crust (∼25–30 km), then micro-cumulates (2–3 570 forming shallower crustal levels (∼10 more evolved sulfide-poor hybrid 56–70 1 602 μg/g), finally even rhyodacitic 66–76 <0.5 6.4 wt.%) differentiating (∼7 km). Sulfide-free quenched basaltic andesitic near surface levels, carry no textural evidence suggesting system returned sulfide-undersaturated state. Finally, we point out two important processes for evolution, reaction replacement clinopyroxene by amphibole observed triggering onset saturation, an increased mafic input followed mingling disaggregation leading dissolution Cu-enrichment magmas.