Minerals formed by the weathering of sulfides in mines of the Czech part of the Upper Silesian Basin

Abstract

This study describes the occurrences of sulfate minerals in mines of the Czech part of the Upper Silesian Basin. This mineralization originates from the oxidation of Fe disulfides contained in the coal matrix and enclosing sediments. The oxidation occurs in the presence of formational brines and chemotrophic bacteria. The brines have a pH between 6.3 and 8.5 and total solute content of up to 300 g/l. They are rich in Na, Ca, K, Mg, Ba and Sr and Cl– is the major anion. The minerals of the pickeringite–halotrichite series with coexisting magnesiocopiapite are formed primarily in drier places and areas where the water is only slightly mineralized. In more humid places where the brines are more concentrated, a diverse assemblage of up to 20 different sulfates are found (e.g. natrojarosite, sideronatrite, metasideronatrite, tamarugite, magnesiocopiapite, bílinite, starkeyite, blödite, rozenite and siderotil). These sulfates are accompanied by halite, sulfur, goethite and a number of phases of uncertain identity, such as sulfates containing Sr and REE. This is an example of mineral paragenesis formed by weathering in a saline evaporite environment, which is extremely rare in Europe but is found in arid regions elsewhere (e.g. in the Atacama Desert in Chile).

Sulphate supergene minerals: An intuitive indicator for deep deposit in plateau regions

“…Among the supergene sulphates minerals, pickeringite is also relatively rare in addition to natrojarosite and naujakasite, which is usually observed in coal mines, highly acidic soils, volcanic vents, mine ventilation areas (Blass & Strehler, 1993; Hammarstrom, Seal, Meier, & Kornfeld, 2005; Jírasek, 2001; Kruszewski, 2013; Montero, Brimhall, Alpers, & Swayze, 2005; Onac et al, 2009; Panov, Dudik, Shevchenko, & Matlak, 1999; Parafifiniuk, 1991; Qiu et al, 2019; Rodgers, Hamlin, Browne, Campbell, & Martin, 2000; Romero et al, 2006; Szakáll et al, 2012; Szakáll & Kristály, 2008; Vertacnik, 1983). It is believed that pickeringite is formed by rapidly evaporating and drying in an acidic solution containing Al, Mg and SO 4 2− , which is similar to the formation process of tamarugite (Bortnikova, Bessonova, & Zelenskii, 2005; Fitzpatrick et al, 2009; King, 1998; Kruszewski, 2013; Martin, Rodgers, & Browne, 1999; Matýsek, Jirásek, Osovský, & Skupien, 2014; Onac et al, 2009; Puscas, Onac, Effenberger, & Povara, 2013; Rodgers et al, 2000; Segnit, 1976; Sgavetti et al, 2009). Bloedite is the water‐containing compound salt of sodium sulphate and magnesium sulphate and is one of the major minerals of mirabilite deposit, which usually exists with carnallite, gypsum and magnesium sulphates (such as epsomite and hexahydrite) that are commonly observed in brine‐rich areas (Alpers, Jambor, & Nordstrom, 2000; Bandy, 1938; Cui, 1996; Dokoupilová, Sracek, & Losos, 2007; Fijał, 1973; Gao, 1997; Mallet, 1897; Sánchez‐Moral, Ordóñez, del Cura, Hoyos, & Cañaveras, 1998; Weiss, 1990; Zheng et al, 2016).…”

High Specific Activity of Radium Isotopes in Baryte from the Czech Part of the Upper Silesian Basin—An Example of Spontaneous Mine Water Treatment

“…Rock massif is oxygen deficient, and water can also contain free CH 4 from natural coal degassing, so it does not cause sulfide decomposition. Once the water reaches the mine works, which have different geochemical conditions, it combines with bacterial activity to participate in sulfide decomposition in both the coal and surrounding rocks [57]. Typically, the SO 4 2content is increased.…”

Geochemical Characterization of Coexisting Precipitates and Waters From High-Sulfidation Epithermal Gold Deposits

“…Alunite is a common alteration mineral in these types of deposits, and alum is a common mineral formed from sulfide mineral oxidation (Szakáll et al, 1997). Espomite is a secondary mineral that is often found growing on the walls of metal mines through sulfide oxidation (Jambor et al, 2000;Steiger et al, 2011;Sracek et al, 2010;Matýsek et al, 2014;Buckby et al, 2003;Jamieson et al, 2015) Figure Hexahydrite is a monoclinic sulfate with water content and was observed as encrustations in the field and its occurrence is a result of sulfide mineral oxidation (Jambor et al, 2000). Starkeyite is a dehydrated version of hexahydrite.…”