Deep to Shallow Sulfide Saturation at Nisyros Active Volcano

Abstract

Recent studies have shown that magmatic sulfide phases are present in a variety of rocks corresponding to diverse geodynamic settings, lithologies, and magma compositions (Z.

Magmatic evolution of the Kolumbo submarine volcano and its implication to seafloor massive sulfide formation

“…The Cu/Ag values of Kolumbo samples reflects a differentiation process similar to the early differentiation stages of the Nisyros volcano (Georgatou et al 2022). The Cu/Ag values at Kolumbo are interpreted to yield mantle-like ratio at basaltic composition and decrease continuously until ~ 0.9 wt% MgO, indicating uninterrupted formation of magmatic sulfides since early differentiation in the lower crust until the trachyte/rhyolite stage in the upper magma chamber (Fig.…”

“…This apparent low S content is likely the result of S loss by degassing upon eruption, while outlying high S values (i.e., > 500 µg•g −1 ) in felsic samples are explained by seawater/rock interaction upon eruption (Brandl et al 2022). The mechanisms triggering early sulfide saturation are unclear but may be related to magnetite or amphibole crystallization (Georgatou et al 2022;Jenner et al 2010). Similarly, amphibole replacing clinopyroxene modifies the redox state of the melt and may trigger sulfide saturation as the primitive basaltic melt evolves toward an andesite composition in the lower crustal reservoir (Georgatou et al 2021(Georgatou et al , 2022.…”

“…The mechanisms triggering early sulfide saturation are unclear but may be related to magnetite or amphibole crystallization (Georgatou et al 2022;Jenner et al 2010). Similarly, amphibole replacing clinopyroxene modifies the redox state of the melt and may trigger sulfide saturation as the primitive basaltic melt evolves toward an andesite composition in the lower crustal reservoir (Georgatou et al 2021(Georgatou et al , 2022. This process is however not clearly identified in Kolumbo.…”