Wolframová a sulfidická hydrotermální mineralizace z Pekelského vrchu u Jihlavy (Česká republika)

Abstract

The occurrence of tungsten mineralization of greisen type with the dominant ferberite and scheelite in quartz veins was detected in 1963 at the site Pekelský vrch near Jihlava. We conducted a detailed mineralogical research of the vein material sampled in the years 2020 - 2022. The dominating tungsten mineralization is represented especially by two chemically different types of ferberite, including relatively pure younger ferberite and older generation of ferberite containing substantial amounts of hübnerite (19 - 45 mol.%) and huanzalaite component (2.6 - 4.1 mol.%). Widespread scheelite replaces earlier ferberite, and is replaced by younger generation of ferberite. The Ti,W-rich columbite-(Fe) is an accessory phase associated with younger generation of ferberite. In addition to tungsten mineralization, there was recorded a varied sulphidic mineralization with dominating pyrite, chalcopyrite, galena, molybdenite and rare sulphosalts including matildite and gustavite, and locally also tellurosulphides (joséite-A and joséite-B), native bismuth and electrum. The supergene mineralization with Fe3+ hydroxides, bismutite, bismite, petitjeanite, kintoreite, corkite, plumbogummite, jarosite and iodargyrite is relatively rare. The gangue is dominated by quartz with flakes of low-F phengitic muscovite and rare siderite and fluorapatite. In addition, a fragment of an Al-rich rock, composed of corundum, andalusite, margarite and muscovite, was identified in the dump material. A total of 32 mineral species was found there.

Mineralogy and Origin of Vein Wolframite Mineralization from the Pohled Quarry, Havlíčkův Brod Ore District, Czech Republic: Interaction of Magmatic and Basinal Fluids

“…Ore minerals are dominated by tabular wolframite (Frb 53-88 Hub 8-45 Hua 2-4 ; the Mg contents were analyzed at two sites only), which is accompanied especially by scheelite and minor sulfides (pyrite, arsenopyrite, molybdenite, chalcopyrite, and galena) and locally by cassiterite, joséite, and native bismuth. The exceptions are columbite-(Fe) to qitianlingite, gustavite, matildite, and/or pyrrhotite [10,15,44]. At the Jihlava-Pekelský vrch site, there also occurs late wolframite II (Frb 99-100 Hub 0-1 ), replacing scheelite [10].…”

“…The exceptions are columbite-(Fe) to qitianlingite, gustavite, matildite, and/or pyrrhotite [10,15,44]. At the Jihlava-Pekelský vrch site, there also occurs late wolframite II (Frb 99-100 Hub 0-1 ), replacing scheelite [10].…”

“…This is also the case in the Moldanubian Zone of the Bohemian Massif, which hosts several small non-economic occurrences of wolframite mineralization bound to fracture-related greisens and quartz veins around the largest granitic body (Figure 1a). The mineralogy of these occurrences is poorly constrained by modern data, apart from the most recent work on Jihlava occurrence [10], which was focused on the mineralogical and crystal-chemical study of the whole mineral paragenesis and was also supplemented by enough analytical data. In contrast, the earlier papers were either focused only on certain mineral phase(s) (typically wolframite) or based on a very low number of investigated samples and/or collected analytical data, making them questionably conclusive.…”

“…The Moldanubian wolframite contains up to 3-11 mol. % of huanzalaite component [10,[13][14][15] and the reason of such Mg-enrichment is not known here. Second, the scarce available compositional data suggest that micas from these mineralizations belong to low-F low-Li muscovite [10,15], indicating a chemically contrasting genetic environment with respect to typical Saxothuringian greisens, which are usually F-and Li-rich [5,6,8,16].…”

“…% of huanzalaite component [10,[13][14][15] and the reason of such Mg-enrichment is not known here. Second, the scarce available compositional data suggest that micas from these mineralizations belong to low-F low-Li muscovite [10,15], indicating a chemically contrasting genetic environment with respect to typical Saxothuringian greisens, which are usually F-and Li-rich [5,6,8,16]. Third, some Moldanubian occurrences are considered to be overprinted by the regional (Variscan) metamorphism together with their host rocks [17,18], which is, again, a feature usually unrecognized worldwide.…”