Trace Elements and Minerals in Fumarolic Sulfur: the Case of Ebeko Volcano, Kuriles
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Hindawi Geofluids Volume 2018, Article ID 4586363, 16 pages https://doi.org/10.1155/2018/4586363 Research Article Trace Elements and Minerals in Fumarolic Sulfur: The Case of Ebeko Volcano, Kuriles E. P. Shevko,1 S. B. Bortnikova,2 N. A. Abrosimova,2 V. S. Kamenetsky ,3,4 S. P. Bortnikova,2 G. L. Panin,2 and M. Zelenski 3 1 Sobolev Institute of Geology and Mineralogy, SBRAS, Novosibirsk 630090, Russia 2Trofmuk Institute of Petroleum Geology and Geophysics, SBRAS, No. 3, Novosibirsk 630090, Russia 3Institute of Experimental Mineralogy RAS, Chernogolovka 142432, Russia 4EarthSciencesandCODES,UniversityofTasmania,PrivateBag79,Hobart,TAS7001,Australia Correspondence should be addressed to M. Zelenski; [email protected] Received 25 June 2017; Revised 13 October 2017; Accepted 14 December 2017; Published 20 March 2018 Academic Editor: Joerg Goettlicher Copyright © 2018 E. P. Shevko et al. Tis is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Native sulfur deposits on fumarolic felds at Ebeko volcano (Northern Kuriles, Russia) are enriched in chalcophile elements (As- Sb-Se-Te-Hg-Cu) and contain rare heavy metal sulfdes (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. Te 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. Te presence of rare sulfdes (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 sulfdes induced by the reaction of acid solutions with H2S at ambient temperatures. Te elemental composition of native sulfur can be used to qualitatively estimate elemental abundances in low-temperature fumarolic gases. 1. Introduction sublimates are similar to those of ore bodies that form in magmatic environment [2, 5–7]. Because the main compo- Volcanic fumaroles are surfcial manifestations of magmatic nent of the majority of fumarolic gases is water steam, they degassing. Fumarolic gases mainly comprise the volatile can be condensed in a special cooled fask. Such condensates components of H2O, CO2, SO2, HCl, and HF, but high- ∘ ofen contain signifcant concentrations of metals (i.e., tens to temperature fumarolic gases (>400 C) also commonly trans- hundreds of ppm) and are used to study the gaseous transport port many metallic and nonmetallic compounds, which have of metals (e.g., [4, 5, 8, 9]). ∘ sufciently high vapor pressure at elevated temperatures. Low-temperature fumaroles (i.e., 200 C and lower) are Tese include native elements, oxides, halides, and more not well-characterized in terms of their gaseous transport due complex compounds (e.g., [1–4]). to their generally low concentrations of metallic elements; Rapid decrease in the temperature of gas at or near the saturation vapor pressures of these elements decrease the surface, together with abrupt change from reducing to by 1-2 orders of magnitude for every hundred degrees. Very oxidizing conditions, results in the oversaturation of the low metal contents in low-temperature condensates are ofen transported volatile compounds. Te latter precipitate inside obscured by an overwhelming amount of colloidal sulfur or around fumaroles, forming black or colorful deposits, [10, 11]. Metals can be adsorbed by sulfur particles and are which are called sublimates. It has long been noticed that the further deposited on the bottle (vial) walls. Because native zonation and compositions of high-temperature fumarolic sulfur can only be dissolved in hot aqua regia (which may 2 Geofuids introduce its own contaminants), the accurate analysis of low- these metals suggested that they originated from magma via temperature gas condensates is a complex problem. volcanic degassing. At the same time, metals and aerosol particles are In the present work, we report new data on the chemical transported by low-temperature gas and precipitate together composition of native sulfur, leachates from native sul- with native sulfur around fumarole vents, forming well- fur, and rare minerals as inclusions in native sulfur from known yellow incrustations. Tese incrustations and even Ebeko volcano (North Kuriles, Russian Far East) in order well-shapedsulfurcrystalsofencontainmineralandrock to understand the transport of elements in low-temperature inclusions, which were also carried by and deposited from fumarolic gases. Native sulfur from the volcano was studied fumarolic gas. Such sulfur can help to study the gases using a variety of modern methods (including Synchrotron themselves. All components carried by the gas are inevitably Radiation induced X-ray Fluorescence Spectroscopy (SR- found in fumarolic sulfur; therefore, the composition of XRF), leaching by water followed by ion chromatography thegascanbeestimatedataqualitativelevel.Unfortu- and ICP-AES, and dissolution in carbon disulfde followed by nately, the quantitative analysis of this gas composition using SEM-EDS). Ebeko was chosen because of its accessibility as fumarolic sulfur is impossible due to the strong fractionation wellasthefactthatitfeaturesvariousandpersistentfumarolic of elements, including sulfur itself that occurs during the activity occurring at several fumarolic felds. Our data show dischargeofgas.Mostofthesulfurandothermetallicand that Ebeko sulfur is enriched in volatile chalcophile elements. nonmetallic elements escape fumarolic vents with the gas Te presence of rare sulfdes (i.e., argentite, covellite, and and are dissipated in the environment; thus, only a small cinnabar) and abundant pyrite may be fully explained by the (and unknown) fraction of these elements is deposited in acid leaching of rock particles followed by sulfde precipi- tation from leachates; that is, rock aerosols may serve as a incrustations. source for chalcophile metals and iron. Te existing data on volcanic sulfur composition data have been obtained using mass-spectrometry (ICP-MS), 2. Study Area and Methods atomic emission spectroscopy (ICP-AES), scanning elec- ∘ ∘ tron microscopy with energy-dispersive spectroscopy (SEM- 2.1. Ebeko Volcano and Fumaroles. Ebeko (51.41 N, 176.01 E, EDS), refectance spectrometry [12–15], and wet chemical 1156 m asl) is an active andesitic stratovolcano in the Kurile methods [16]. For example, Kargel et al. [12] studied the trace island arc, where the Pacifc Plate is being subducted under element chemistry of native sulfur from a terrestrial volcanic- the Okhotsk Plate. Ebeko is located in the northern part hydrothermal environment to determine the relationship of Paramushir Island (Figure 1), 10 km from the town of betweenthecolorofsulfuranditstraceelement/trace Severo-Kurilsk.Tesummitofthisvolcanocomprisesfour mineral contents. A few tenths of a percent to a few percent adjoining craters that are 250–300 m wide and 70–100 m deep of chalcophile trace elements (As, Se) commonly occur in and extend in the meridian direction. Several cold lakes are sulfur and produce material with yellow, brown, orange, located in the Middle and South craters; a hot lake is located and red tints. Two-tenths of a percent to two percent of in the North crater. crystalline pyrite (FeS2) commonly produces green, gray, and Ebeko is characterized by occasional phreatomagmatic black volcanic sulfur. Specimens that have formed by direct eruptions and abundant permanent fumaroles and thermal deposition from vapor or by the melting/recrystallization springs [17]. Between eruptions, the volcano exists in a state of such deposits have a bright yellow color and the purest of strong and persistent fumarolic and hydrothermal activity. compositions. Numerous fumaroles are located inside craters and on the Zeng et al. [15] analyzed the trace and rare earth element outer slopes of the cones (Figures 1 and 2). Tese fumaroles compositions of native sulfur “balls” from a hydrothermal belong to four fumarolic felds: the NE fumarolic feld (which feld in Northeast Taiwan. Tey determined that their con- is the largest feld); the “July” fumarolic feld; the South feld; tentsofAl,Ti,Rb,Cs,Ba,V,Cr,Co,Ni,Nb,Pb,T,U,andREE and the SE feld. Fumaroles are encrusted with native sulfur were mostly derived from andesite; their contents of Mg, K, of diferent colors, ranging from bright yellow to dark gray and Mn mostly originated from seawater; and their contents to pink (Figures 2 and 3), and reached a maximum height of of Fe, Cu, Zn, and Ni were partly derived from magma. Using 1.5 m during the time of sampling (Figure 2). Te main com- sulfur composition data, they suggested a “glue pudding” ponent of Ebeko fumarolic gases is H2O(97–99mol%);the growth model to explain the origin of these native sulfur other components are CO2,HCl,SO2,H2S, N2,Ar,HF,H2, balls. Gof et al. [16] studied various metals in native sulfur CH4,CO,andHe[18,19]. to