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Ferenc S.,Katedra geografie a geologie | Bakos F.,Drnava | Demko R.,Statny Geologicky Ustav D. Stura | Peter Kodera A.,Katedra loziskovej geologie
Bulletin Mineralogicko-Petrologickeho Oddeleni Narodniho Muzea v Praze | Year: 2014

Siderite-quartz-sulphidic veins in the Kohút Zone of Veporic Unit, are best developed at Cinobaňa, Lovinobaňa, and Uderiná villages, in vicinity of the Veporic/Gemeric Units tectonic contact (the Lubeník-Margecany Zone). The mineralization occurs at the small historical deposits, localised within Alpine shear zones (NNE - SSW to W - E directions) in Variscan granitoids, amphibolites and mica schists. Succession of the mineralised structures filling is as follows: relics of host-rock minerals (garnet, xenotime, ilmenite, rutile, magnetite, hematite)→metamorphic mineralization (quartz with CO2-N2 rich fluid inclusions)→Ni-Co sulphidic stage (quartz, pyrite, arsenopyrite, siegenite, polydymite, gersdorffite)→ carbonate stage (siderite, ankerite, Fe dolomite, calcite)→alpine-type paragenesis stage (quartz, apatite, monazite, xenotime, schorl, dravite, foitite, ilmenite, rutile, muscovite, chamosite, calcite)→quartz-sulphidic stage, with two substages: a) Cu sulphidic (pyrite, chalcopyrite, tetrahedrite, galena, sphalerite, stibnite, eugenite?), b) cinnabar (cinnabar, calcite, marcasite)→hematite stage (hematite). Supergene stage is represented by: cinnabar, covellite, chalcocite, limonite and a mixture of Fe, Cu, As, Sb, Ni sulphates/oxides. Quartz with CO2-N2 rich fluid inclusions forms only relics in Fe carbonates and contains a high- salinity aqueous phase (31.9 - 39.8 wt. % NaCleq.) fluid inclusions with CO2 and N2 (up to 41 mol. % N2). Variability in size of gaseous phase and halite crystals, as well as, total homogenization temperatures between 223 - 364°C, suggest a heterogeneous fluid. Bottom of homogenisation temperatures approaching to the real quartz crystallisation temperatures. Two phase, CO2- rich aqueous fluid inclusions in quartz of alpine paragenesis has a salinity 9.6 - 15.2 wt. % NaCl eq., total homogenization temperature ranged from 272 to 347°C. Stable C-O isotope ratios in siderites (δ13C[PDB] -9.6 to -5.6 ‰, δ18O[SMOW] 15.2 - 16.4 ‰) are reminiscent of south Gemeric siderite-polymetallic veins. We assume that quartz with N2- rich inclusions is a product of pre-Upper Cretaceous tectonometamorphic processes, occurring during Lower - Middle Cretaceous (P, T maximum of the Alpine metamorphosis). Siderite was formed during Upper Cretaceous, probably from „Gemeric type“formation brines circulating in the Lubeník - Margecany line and adjacent tectonic structures, after collision of the Gemeric-Veporic Units. Formation of quartz with alpine-type paragenesis was caused by precipitation from SiO2-rich fluids circulating in shear zones after maximum of the Early Cretaceous metamorphism, as a consequence uplift and cooling of the Central Western Carpathians. © 2014, Bull. mineral.-petrolog. Odd. Nár. Muz. (Praha). All rights reserved. Source

Bonova K.,Ustav Geografie | Bella P.,Katedra Geografie | Kovacik M.,Statny Geologicky Ustav D. Stura RC Kosice | Bona J.,Kpt. Jarosa 13 | And 3 more authors.
Acta Geologica Slovaca | Year: 2014

A combination of sedimentological and mineralogical methods with emphasis on heavy mineral assemblage research applied to allochthonous sediments in the Liskovská jaskyňa Cave located in the western part of the Liptovská kotlina Basin (in the tectonic horst composed of Triassic limestones at foothills of the Chočské vrchy Mts.) were used for the identification their provenance and sedimentary history. Allochthonous fine-grained sediments were studied in three profiles (LI-1 to LI-3). The sediments originated mostly from the suspension in slow water flow to stagnant water (slackwater facies). This material could be later redeposited during the younger flooding event and small-scale slumps and gravity flows (mudflows) have been locally generated on steeper cave floors. Based on mineralogical study the cave sediments are composed of quartz, muscovite, calcite, chlorite, K-feldspar, plagioclase and dolomite. A heavy mineral assemblage is formed by garnet, zircon, apatite, monazite, tourmaline, staurolite, amphibole, rutile, titanite, epidote, sillimanite, allanite, andalusite, pyroxene and xenotime. Opaque minerals are represented by ilmenite, pyrite, magnetite, Cr-spinel, hematite, Cu-sulfides and Fe-oxyhydroxides. Their mineralogical character indicates the heterogenous source material which was transported by the Váh River. The results are significant for a more accurate reconstruction of origin and development of the cave, mainly its sedimentary phases in Middle and Late Pleistocene related to floods from the adjacent river bed. Source

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