Trace Elements and Minerals in Fumarolic Sulfur: The Case of Ebeko Volcano, Kuriles

Abstract

Native sulfur deposits on fumarolic fields at Ebeko volcano (Northern Kuriles, Russia) are enriched in chalcophile elements (As-Sb-Se-Te-Hg-Cu) and contain rare heavy metal sulfides (Ag2S, HgS, and CuS), native metal alloys (Au2Pd), and some other low-solubility minerals (CaWO4, BaSO4). Sulfur incrustations are impregnated with numerous particles of fresh and altered andesite groundmass and phenocrysts (pyroxene, magnetite) as well as secondary minerals, such as opal, alunite, and abundant octahedral pyrite crystals. The comparison of elemental abundances in sulfur and unaltered rocks (andesite) demonstrated that rock-forming elements (Ca, K, Fe, Mn, and Ti) and other lithophile and chalcophile elements are mainly transported by fumarolic gas as aerosol particles, whereas semimetals (As, Sb, Se, and Te), halogens (Br and I), and Hg are likely transported as volatile species, even at temperatures slightly above 100°C. The presence of rare sulfides (Ag2S, CuS, and HgS) together with abundant FeS2 in low-temperature fumarolic environments can be explained by the hydrochloric leaching of rock particles followed by the precipitation of low-solubility sulfides induced by the reaction of acid solutions with H2S at ambient temperatures. The elemental composition of native sulfur can be used to qualitatively estimate elemental abundances in low-temperature fumarolic gases.

Volatile Chalcophile Elements in Native Sulfur from a Submarine Hydrothermal System at Kueishantao, Offshore NE Taiwan

“…Se, Te and S may undergo fractionations due to their distinctive geochemical behaviors during partial melting, although they have a strong geochemical coherence in magmatic-hydrothermal processes [7,56]. For example, during mantle melting, sulfur moves most readily into the sulfide melt [2], whereas Te and Se are preferentially retained in the residual mantle, with Te being more compatible than Se [45,54,57].…”

“…Consequently, the relative enrichment of these elements is Te >> Se > S in the metallic melt, also proved by the enrichment factors shown in Figure 6. These volatile elements in the melt will form a vapor phase caused by decompression or diffusion during magma ascent [7,58]. When the sulfur-dominated vapor phase ascends to the seafloor, Se and Te are retained and enriched in the native sulfur matrix during cooling from seawater.…”

“…represents Andesite. Data sources: KST native sulfur matrix (this study); seawater [59]; CI chondrite and pyrolite [4]; volcanic sulfur sublimate [21]; Spinel Lherzolite [5]; EPR 13 • N sulfide [16]; Lau Basin molten sulfur [19]; Lau Basin sulfide [43]; Harzburgite [3]; Primitive mantle sulfide [45]; KST native sulfur chimney [42]; Basalt [46,[60][61][62]; Andesite [7]; Izu-Bonin sulfides [39]. Mariana Arc native sulfur [20]; Manus Basin sulfide and sulfidic sediment [18].…”

“…As and Sb are expected to behave coherently during magmatic-hydrothermal processes due to these elements having the same charges and similar ionic radii [45,46]. They are transported to the seafloor via a vapor phase [7,19,63] and their geochemical behaviors during mantle melting could help to ascertain controls on their enrichment in the sulfur matrix. It can be seen from Figure 5c that Se/As ratios of the Kueishantao sulfur matrix are much lower than that in volcanic sulfur sublimate and CI chondrite, a little higher than Lau Basin molten sulfur and sulfide, and similar to, or within the range of basalts, Mariana arc sulfur, EPR 13 • N sulfide and the Kueishantao native sulfur chimney.…”

“…The abundance of these elements in the mantle could also be indicative of several planetary processes such as the formation of the Earth's core and the Late Veneer process, meaning the late accretion of asteroidal or cometary material to terrestrial planets [3][4][5]. Moreover, studying the geochemical behavior of these chalcophile elements in hydrothermal deposits could facilitate a greater understanding of the magmatic-hydrothermal processes that occur in seafloor hydrothermal systems [6][7][8]. Notably, the distributions and concentrations of chalcophile elements in arc-related hydrothermal deposits and systems can be used for deciphering provenance, indicating magmatic-hydrothermal processes such as fluid-rock interaction and mineral precipitation during the ascent of hydrothermal fluids from the mantle to the seafloor, and reflecting the physicochemical conditions of the hydrothermal system [9][10][11][12].…”