Supergene minerals from Ag-Pb-Zn-Cu base-metal historical ore deposits at Českomoravská vrchovina Highlands, Czech Republic; A reviewArticle PDF
Supergene minerals from Ag-Pb-Zn-Cu base-metal historical ore deposits at Českomoravská vrchovina Highlands, Czech Republic; A review
The work presents a brief characterization of the known oxidic minerals of the supergene zone, especially from Moldanubian Zone, Moravosilesian, Bohemian Massif. Simple ore mineralizations consist predominantly of pyrite, sphalerite, galena, arsenopyrite, and also tetrahedrite, chalcopyrite and Pb-Sb±Ag sulphosalts in quartz and baryte-quartz ±carbonate veins. A relative simplicity of the supergene mineral assemblage follows the system of both Fe–Zn–Pb–Cu–S (±As, Ag, Bi, P, Ba, Sb, Cl) ore mineralizations and Si–Al–Ca–Mg–K–H2O–CO2 components of the host rocks, which is, however, quantitatively somewhat different among individual ore districts. The most abundant supergene minerals (except for Fe-oxo hydroxides) are jarosite, gypsum, cerusite, anglesite, pyromorphite and malachite, occurring in almost all districts. Only in the Štěpánov ore district also brochantite and sporadic yellow Pb-Cu-Sb ochres are relatively common along with malachite, in the Brod ore district schwertmannite, scorodite, pharmacosiderite and locally pyromorphite, as well as smithsonite in Jemnice and pseudomalachite in Krucemburk are common. At other localities the above listed and other minerals (hydrozincite, plumbojarosite, kaňkite, greenockite, chrysocolla, linarite, hemimorphite, melanterite, rozenite) form only volumetrically insignificant aggregates, somewhere only in mm dimensions. Very rarely, minerals containing molybdenum (wulfenite at Kosov and Lačnov, ferrimolybdite from pyrite mineralization near Nová Bystřice), vanadium (microscopic descloisite at Krucemburk), cadmium (greenockite at Maršov and Švařec), bismuth and tungsten (sporadic stolzite, russelite and hydrokenoelsmoreite at Vysoká) and very sporadic silver were identified (Ovčín). Neither the textures of ore mineralizations nor the young geomorphological development of the Českomoravská vrchovina Highlands were not, with a few exceptions, favorable for development of thicker supergene zones, including typical gossanes.
Eva Víšková*, Stanislav Houzar, Vladimír Hrazdil, Department of Mineralogy and Petrography, Moravian Museum, Zelný trh 6, 659 37 Brno, Czech Republic; *corresponding author: email@example.com