Supergene minerals at the Huber stock and Schnöd stock deposits, Krásno ore district, the Slavkovský les area, Czech Republic (original) (raw)
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Journal of GEOsciences, 2012
Rich supergene mineral association with prevalence of Pb was found in a shallow gallery of the Rovnost mine, the Jáchymov (St. Joachimsthal) ore district, western Bohemia (Czech Republic). Mimetite occurs as colourless transparent flexible fibres up to 1 mm in length and up to 10 μm in diameter. The fibres form greyish white aggregates (up to 1 cm 2 in area) grown on the surface of gangue strongly affected by supergene alteration. The results of the single crystal X-ray diffraction study of mimetite with R 1 = 0.0381 are fully consistent with data reported previously for this mineral phase. According to electron microprobe study, interesting are namely elevated contents of SiO 4 (up to 0.16 apfu). Among the supergene minerals, cerussite, anglesite, wulfenite, philipsbornite-segnitite minerals, pyromorphite and metazeunerite were determined based on powder X-ray diffraction and electron microprobe analyses. The presence of U (~ 4 wt. % UO 3) and As (up to 4 wt. % As 2 O 5) in wulfenite is particularly noteworthy. Characteristic of the studied mineral association are elevated and omnipresent contents of F-. This mineral assemblage is considered to be a result of a long-term in-situ weathering in near-surface conditions.
Journal of Geosciences, volume 56 (2011), issue 3, 273 - 298
Supergene mineralization at the hydrothermal Farbište ore occurrence near Poniky, central Slovakia, was studied using optical and electron scanning microscopy, X-ray powder diffraction, electron microprobe and IR spectroscopy. Two principal associations of the supergene minerals were observed. The first is represented mostly by tyrolite with a higher content of sulphate groups and chrysocolla associated with copper carbonates. The second is characterized by a rich assemblage of copper arsenates: low-S tyrolite, strashimirite, parnauite, olivenite, cornwallite, cornubite, euchroite and clinoclase, which occur together with chrysocolla, bariopharmacosiderite-Q, brochantite, azurite and malachite. Both associations formed as a result of decomposition of primary ore minerals, especially tennantite, which is the prevalent primary ore mineral at the Farbište occurrence and was the main source of Cu, As and S ions in the supergene zone.
Supergene mineralization at the hydrothermal Farbište ore occurrence near Poniky, central Slovakia, was studied using optical and electron scanning microscopy, X-ray powder diffraction, electron microprobe and IR spectroscopy. Two principal associations of the supergene minerals were observed. The first is represented mostly by tyrolite with a higher content of sulphate groups and chrysocolla associated with copper carbonates. The second is characterized by a rich assemblage of copper arsenates: low-S tyrolite, strashimirite, parnauite, olivenite, cornwallite, cornubite, euchroite and clinoclase, which occur together with chrysocolla, bariopharmacosiderite-Q, brochantite, azurite and malachite. Both associations formed as a result of decomposition of primary ore minerals, especially tennantite, which is the prevalent primary ore mineral at the Farbište occurrence and was the main source of Cu, As and S ions in the supergene zone.
Supergene Pb-Cu-(Sb) mineral assemblage in abandoned epithermal deposit Rudno nad Hronom, Slovakia
Acta Geologica Slovaca, 2021
An unusual assemblage of Pb-Cu-(Sb)-(Mn) supergene minerals, represented by mottramite, phosphohedyphane, mimetite, minerals of the segnitite-beudantite series, anglesite, cerussite, oxyplumboroméite, brochantite, devilline, gypsum and coronadite was recently identified at the Priečna, Johan de Deo and Anna-Zubau epithermal ore veins near Rudno nad Hronom, Štiavnické vrchy Mts., Slovak Republic. Mottramite is a rare mineral at the Rudno deposit and this is the first reported occurrence in the Western Carpathians. Also phosphohedyphane occurs only rarely at the deposit. The Pb 2+ <-> Ca 2+ substitution between phosphohedyphane and pyromorphite was observed. An extensive substitution between As and S was recognised on the T site in the minerals of the beudantite-segnitite series. Anglesite and cerussite are relatively abundant supergene minerals, especially in the proximity of primary galena relicts. Secondary Cu sulphates (brochantite and devilline) are only secondary minerals found also in macroscopic size. Brochantite forms dark green tabular crystals up to 0.1 mm. Devilline occurs as a light green-blue acicular crystals grown on brochantite. Gypsum was found with this assemblage. Rare coronadite, Mn supergene mineral is also found at the Rudno nad Hronon locality.
New data on mineralogy of the Vysoký Kámen deposits near Krásno, Slavkovský les area, Czech Republic
Journal of GEOsciences, 2012
Detailed mineralogical study focused on two deposits located on slopes of the Vysoký Kámen hill near Krásno in the proximity of the town of Horní Slavkov in Czech Republic. The open pit exploiting industrial feldspar material (mainly feldspathites and aplitic granites) offerred new finds of minerals in the Slavkovský les. The following minerals were identified: autunite, bertrandite, beryl, goethite, hematite, koechlinite, kolbeckite, meta-autunite, powellite and scheelite. In the nearby abandoned greisen deposit a phosphate mineral association was observed consisting of cacoxenite, leucophosphite, vivianite, wavellite and minerals of the chalcosiderite-turquoise and strengite-variscite series. In addition to them dickite and goethite were identified. The genesis of these mineral associations is discussed.
2017
The greisens evolved in the apical part of the Hub stock, formed by weakly greisenised topaz granites, are predominantly represented by Li-mica-topaz and topaz-Li-mica greisens. These greisens, relative to weakly greisenised topaz granites, are enriched in Ca, F, Fe, Li, Si, Sn and W and depleted in Al, K, Mg, Na, Ti, Y, Zr and ΣREE. Weakly greisenised topaz granites show convex tetrads in the normalised REE patterns. Compared to topaz granites, the greisens display lower ΣREE concentrations, partly higher negative Eu anomaly, high Y/Ho and low Zr/Hf ratios. Li-micas occurring in greisens are represented by zinnwaldite. Chemical composition of cassiterite is near to ideal SnO 2 (>99 wt.% SnO 2 ). The wolframite is represented by manganoan ferberite.
Mineralogy and Petrology, 2017
Tourmaline-supergroup minerals are common gangue minerals in Sb-hydrothermal veins on Betliar-Straková, Čučma-Gabriela and Rožňava-Peter-Pavol vein deposits in the Rožňava area, Slovakia. Tourmaline-supergroup minerals form relatively large prismatic to radial aggregates of parallel black to greyish-black crystals. Tourmaline-supergroup minerals from Betliar-Straková and Rožňava-Peter-Pavol are almost homogeneous with intermediate schorl-dravite composition. Čučma-Gabriela tourmaline have distinct zoning with massive core of the schorlitic-to-feruvitic shifting to schorlitic-to-dravitic composition, and dravitic to magnesiofoititic rim. The tourmaline composition is influenced by two main substitutions, namely Ca(Mg,
Mineralogy and Petrology, 2018
The Au-Ag-Pb-Zn-Cu epithermal deposit Banská Hodruša of intermediate-sulphidation type is located in the Middle Miocene Štiavnica stratovolcano on the inner side of the Carpathian arc in Slovakia. This deposit represents an unusual subhorizontal multi-stage vein system, related to processes of underground cauldron subsidence and exhumation of a subvolcanic granodiorite pluton. Veins are developed on a low-angle normal shear zone, possibly representing a detachment zone in andesitic wall rocks that formed during emplacement and exhumation of the granodiorite pluton. The deposit consists of two parts, separated by a thick sill of quartz-diorite porphyry. The eastern part is currently mined, and the western part has already been depleted. The Banská Hodruša mineralization was formed during four stages: (1) low-grade silicified breccia at subhorizontal structures at the base of the deposit; (2) stockwork of steep veins with rhodonite-rhodochrosite, quartz-sulphide-carbonate and quartzgold assemblages; (3) thin quartz-gold veins with medium dip in tension cracks inside the shear zone and complementary detachment hosted quartz-base metals-gold veins; (4) Post-ore veins. Gold and electrum (920-730) occur as intergrowths with base metal sulphides or hosted in quartz and carbonates, accompanied by Au-Ag tellurides (hessite, petzite). Rare Tepolybasite and Cu-cervelleite result from re-equilibration of early Te-bearing minerals during cooling. Sulphide minerals include low Fe sphalerite (~ 1.25 wt%), galena, chalcopyrite, and pyrite. The wall rock alteration is represented mostly by adularia, illite, chlorite, quartz, calcite and pyrite. Precipitation of gold, Au-Ag tellurides, Mn-bearing minerals and adularia resulted from boiling of fluids due to hydraulic fracturing, as well as opening of dilatational structures within the shear zone.
Mineralogia Polonica
The Miedzianka mining district has been known for ages as a site of polymetallic ore deposits with copper and, later, uranium as the main commodities. Although recently uneconomic and hardly accessible, the Miedzianka ores attract Earth scientists due to the interesting and still controversial details of their ore structure, mineralogy and origin. Our examination of the ore mineralization from the Miedzianka district was based exclusively on samples collected from old mining dumps located in the vicinity of Miedzianka and Ciechanowice, and on samples from the only available outcrop in Przybkowice. In samples from the Miedzianka field, chalcopyrite, pyrite, galena, bornite, chalcocite, digenite, arsenopyrite, magnetite, sphalerite, tetrahedrite-tennantite, bornite, hematite, martite, pyrrhotite, ilmenite, cassiterite and covellite are hosted in quartz-mica schists and in coarse-grained quartz with chlorite. In the Ciechanowice field, the ore mineralization occurs mainly in strongly c...