The Biely Vrch deposit in the Western Carpathians is assigned to the shallow, sulfide-poor porphy... more The Biely Vrch deposit in the Western Carpathians is assigned to the shallow, sulfide-poor porphyry gold deposit type and has an exceptionally low Cu/Au ratio. According to 3-D geochemical models, there is a limited spatial correlation between Au and Cu due to the primary introduction of gold by a salt melt and Cu by low-density vapor. Despite a rough spatial correlation of gold grades with quartz stockwork intensity, gold is hosted mostly by altered rock, exclusively in native form. Three main gold mineral assemblages were recognized here. In the deepest parts of the system, the K-and Ca-Na silicate gold assemblage is associated with minerals of high-temperature alteration (plagioclase, K-feldspar, actinolite), with gold grades and fineness depending on depth and potassium content of the host rock: K-silicate alteration hosts the lowest fineness gold (~914), whereas Ca-Na silicate alteration has the highest (~983). The intermediate argillic gold assemblage is the most widespread, with gold hosted mainly by chlorite, illite, smectite, and interstratified illite-chlorite-smectite minerals. The gold fineness is mostly variable (875-990) and inherited from the former gold mineral assemblages. The latest advanced argillic gold assemblage has its gold mostly in kaolinite. The extremely high fineness (~994) results from gold remobilization by late-stage aqueous magmatic-hydrothermal fluids. Uncommon bonanza-grade appears where the earlier gold mineral assemblages were further enriched by this remobilized gold. Primary precipitation of gold occurred during ascent and cooling of salt melts at 450 to 309°C, mostly during retrograde quartz solubility.
Precious metal Au-Ag vein type (low-sulfidation) is the youngest epithermal mineralization in the... more Precious metal Au-Ag vein type (low-sulfidation) is the youngest epithermal mineralization in the Pukanec ore district. This mineralization is represented by electrum in quartz veinlets intersected in boreholes. Supergene-enriched zones that contain quartz and clay debris, secondary Mn (Fe) oxides and electrum are developed in the near-surface level of Au-Ag mineralization. These zones which were the main object of mining in Middle Ages are enriched in Au, Ag and Mn.
The neutral mine drainage system at Ľubietová in Slovakia is overwhelmingly dominated by copper (... more The neutral mine drainage system at Ľubietová in Slovakia is overwhelmingly dominated by copper (17 ppm in the most concentrated aqueous sample) and sulfate and almost devoid of iron (0.7 ppb in the most concentrated aqueous sample). This mine drainage is generated by oxidative dissolution of chalcopyrite (CuFeS 2), as confirmed by sulfur isotopes, and its neutral nature is maintained by buffering via the primary carbonates. The rich oxidation zone, composed of abundant libethenite (Cu 2 (PO 4)(OH)), pseudomalachite (Cu 5 (PO 4) 2 (OH) 4), and malachite (Cu 2 (CO 3)(OH) 2), appears to play only a passive and negligible role in the mine drainage generation. The copper-and sulfate-laden water is discharged through the lowermost adits in the ore field; inside the adits, blue gel covers the stream and converts slowly to crystalline langite (Cu 4 (SO 4)(OH) 6 •2H 2 O). X-ray absorption spectroscopy on Cu K edge showed that the local structure inside the gel is similar to that in langite. Calculation of saturation indices showed supersaturation with respect to sulfates (langite, brochantite (Cu 4 (SO 4)(OH) 6)), malachite, and copper arsenates and phosphates. Arsenates and phosphates were not found and do not form, probably because of kinetic hindrance. The solubility product of langite was estimated as log K sp = 17.73. Outside of the adits, transmission electron microscopy showed redox cycling of copper via the formation of nanocrystals of native copper on rock-forming sheet silicates. The copper concentrations are naturally attenuated, being reduced by a factor of 100 once the mine drainage reaches the Hutná river, about 1 km away from the discharge site. Sulfur isotopes document that no copper sulfides are precipitating; copper must be removed from the contaminated water in the form of sulfates or carbonates. The natural attenuation could be responsible for the enrichment of hyporheic sediments with copper whose mineralogy and geochemistry is unknown but its size is estimated to several metric tonnes of copper.
The hydrothermal veins in the area around the town of Dobšiná (Slovakia) are part of a complex Va... more The hydrothermal veins in the area around the town of Dobšiná (Slovakia) are part of a complex Variscan segment, and they host unique high grade Ni-Co-Fe-As ores. 23 samples have been studied in an attempt to describe and understand the complex phase relationships, chemical variability, and formation of the ore. Reflected light microscopy revealed the presence of gersdorffite, arsenopyrite, rammelsbergite, skutterudite, löllingite, native bismuth, as well as minor chalcopyrite and tetrahedrite. The micro-analytical investigation showed the existence of abundant intermediate sulfarsenide-sulfarsenide as well as sulfarsenidediarsenide phases. We have established the compositional ranges of these minerals, and have shown that formation of complex Ni-Co-Fe-sulfarsenides and arsenides are plausible at temperatures less than 200°C; further, that the uncritical use of experimental data in the Ni-Co-Fe-AsS system could lead to incorrect assumptions.
The disseminated copper mineralization is related to the Permi- an postvolcanic hydrothermal acti... more The disseminated copper mineralization is related to the Permi- an postvolcanic hydrothermal activity of basaltic volcanism. The association of minerals reflects composition of wall-rocks, as confirmed by the presence of Ni-Co minerals (siegenite, gersdorffite and carollite). The vein copper mineralization is associated with faults formed during the Alpine overthrust of the Hronicum Unit. These structures allowed the circulation of the hydrothermal fluids. More data are needed to explain the origin of these fluids. Me- tallic elements might be mobilized from disseminated precon- centrations, and subsequently transported and deposited into the structurally favourable milieu. Low temperature chalcopyrite, digenite, covellite, idaite, malachite, azurite, iron hydroxides, jarosite and gypsum repre- sent supergene association of minerals. Acknowledgement We thank ¼. Puškelová from Geological Institute of Slovak Academy of Sciences and D. Ozdín from Geological Survey of Slovak Republic fo...
Gold–sulphide ore from epithermal vein deposit Banská Hodruša consists of gold, electrum, galena,... more Gold–sulphide ore from epithermal vein deposit Banská Hodruša consists of gold, electrum, galena, sphalerite, chalcopyrite, and pyrite. Minor amounts of tellurides are present in the form of hessite, petzite and other rare Au sulphides and tellurides. Pyrite as a common product of hydrothermal alteration occurs mainly in the wall rock. Gangue minerals are represented by abundant quartz and adularia, clay minerals and carbonates. A combination of classical mineralogical methods – optical microscopy, electron microprobe, scanning electron microscopy, powder X-ray diffraction, automated mineralogy methods – QUEMSCAN RMS, TMS, PMA, and chemical analysis were used to determine composition of the head sample and individual ore dressing products, such as mineral jig concentrate, flotation concentrate and waste. The information about mineral composition of head sample, distribution of minerals in ore dressing products, their chemical composition and optimal grain size (P85–88 of 74 μm) has ...
The oldest model ages are similar showing high ^-values and age values around more than 600 Ma. T... more The oldest model ages are similar showing high ^-values and age values around more than 600 Ma. They are typical of polymetallic massive sulphide mineralizations with exception of the ore district Stubai-Ötzal. The main difference is the frequency of radiogenic lead (J-type), causing distinct inhomogenities and anomalous negative model ages. The radiogenic leads are the mobilizates of Alpidic metamorphism (30 and 80 Ma) in the Eastern and Western Alps. The Hercynian granite intrusion of the W. Carpathians have not been seized by the "Tauern crystallization. "The leads of the ore mineralizations connected with the young volcanism show relevant ages or are slightly radiogenic. In the Eastern Alps, strata bound Pb-Zn mineralizations have a tendency to model ages which are stratigraphically too old (B-type). Such a isotope composition is also evident for the Devonian Pb-Zn-Ag-Ba mineralization of the Graz Paleozoic (540-570 Ma) and for most of the Triassic Pb-Zn-(F-Ba)-deposit there are age differences of 150 to 200 Ma. In the Eastern Alps, the lead isotope data of the carbonate-hosted Pb-Zn-ore mineralizations show model ages 160-400 Ma. In the Western Carpathians, the Pbisotope data are comparable with the Alpine data or analogous with mineralizations from the Slovak neovolcanics. The ^-values vary from 8 to 10, corresponding to the average crust lead of the Hercynian granite complexes or to the thorogenic upper crust lead inherited from the pre-Cambrian clastic sedimentation. The comparison is limited to the carbonate-hosted Pb-Zn deposits in respect to the problematic of biogenic and abiogenic sulphate reduction. The sulphide S-isotopes depend on the contemporaneous isotopic composition of the sea water sulphate. Differences in the S-isotope distribution are found between Anisian and Carnian Pb-Znmineralizations confirming different temporal origins. Biogenic reduction processes are more typical in the Eastern Alps. In the Western Carpathians, the acceptance of biogenic sulphide formation is conceivable only for the deposits of Poniky and of the vein range Vysná Slaná. Ore mineralizations influenced by younger endogenic hydrothermal activities would be indicated by Pb-model ages around zero. The C-and O-isotope study show that the Permian magnesites in W. Carpathians are in an adequate position. The Carboniferous-hosted magnesites are characterized by Oisotopes. In both cases, the sedimentary origin cannot be drawn in doubt considering the other facts too. The present state of the knowledge about the origin of siderites is not sufficient in all. Recent sedimentary siderites are distinguishable clearly from those of deep seated veins or of a higher metamorphic environment. The siderites of the Rudnany deposit show affinity to the siderites of Erzberg. But the thermical history of the Erzberg is more complex. Roznava and "Penninic" (Tauern gold veins) seem to be genetically analogous. But, the siderites of the "Penninic" are formed at higher temperatures.
There are Ni-Co minerals occurring mainly in the hydrothermal siderite veins of Alpine age in the... more There are Ni-Co minerals occurring mainly in the hydrothermal siderite veins of Alpine age in the Western Carpathians. The mineral succession scheme is the following: alteration-> siderite-* alpine paragenesis-> Ni-Co-Fe-As minerals-* quartz with Cu-Bi-Fe-Sb-Hg sulphides. The most abundant are in the sulphide (sulphoarsenide, arsenide) stage with less contents of carbonates and silicates. There are often occurred with the Cu minerals-tetrahedrite, tennantite, chalcopyrite and with the others sulphides mainly pyrite and galena. Those were described on numerous deposits and occurrences in the Slovak Republic. Ni-Co-Fe-Cu-As minerals are represented by gersdorffite, cobaltite, arsenopyrite, rammelsbergite, pararammelsbergile, krutovite, ullmannite, skuttcruditc, nickeline and carrollite which were studied in details at the following localities: Vysna Boca, Dobsina and Casta.
The article present the comparison of the Pb-isotope study of antimony-ores from important Sbmine... more The article present the comparison of the Pb-isotope study of antimony-ores from important Sbmineralisation of Western Carpathian: from Tatric unit (Pezinok, Kuchyňa, Pernek, Dúbrava, Magurka, Lom, Trangoška, Jasenie, Kriváň deposits and occurrences), Gemeric unit (Helcmanovce, Grexa and Poproč deposits) and from Eastern Slovakian neovolcanites (Zlatá Baňa). The study is compared with results of previous investigations of affiliated galena mineralisation. The lead is of a crustal origine. The lead from Taric and that from Gemeric unit (and Eastern Slovakian Neovolcanites) seems to be derived from different reservoirs.
The Biely Vrch deposit in the Western Carpathians is assigned to the shallow, sulfide-poor porphy... more The Biely Vrch deposit in the Western Carpathians is assigned to the shallow, sulfide-poor porphyry gold deposit type and has an exceptionally low Cu/Au ratio. According to 3-D geochemical models, there is a limited spatial correlation between Au and Cu due to the primary introduction of gold by a salt melt and Cu by low-density vapor. Despite a rough spatial correlation of gold grades with quartz stockwork intensity, gold is hosted mostly by altered rock, exclusively in native form. Three main gold mineral assemblages were recognized here. In the deepest parts of the system, the K-and Ca-Na silicate gold assemblage is associated with minerals of high-temperature alteration (plagioclase, K-feldspar, actinolite), with gold grades and fineness depending on depth and potassium content of the host rock: K-silicate alteration hosts the lowest fineness gold (~914), whereas Ca-Na silicate alteration has the highest (~983). The intermediate argillic gold assemblage is the most widespread, with gold hosted mainly by chlorite, illite, smectite, and interstratified illite-chlorite-smectite minerals. The gold fineness is mostly variable (875-990) and inherited from the former gold mineral assemblages. The latest advanced argillic gold assemblage has its gold mostly in kaolinite. The extremely high fineness (~994) results from gold remobilization by late-stage aqueous magmatic-hydrothermal fluids. Uncommon bonanza-grade appears where the earlier gold mineral assemblages were further enriched by this remobilized gold. Primary precipitation of gold occurred during ascent and cooling of salt melts at 450 to 309°C, mostly during retrograde quartz solubility.
Precious metal Au-Ag vein type (low-sulfidation) is the youngest epithermal mineralization in the... more Precious metal Au-Ag vein type (low-sulfidation) is the youngest epithermal mineralization in the Pukanec ore district. This mineralization is represented by electrum in quartz veinlets intersected in boreholes. Supergene-enriched zones that contain quartz and clay debris, secondary Mn (Fe) oxides and electrum are developed in the near-surface level of Au-Ag mineralization. These zones which were the main object of mining in Middle Ages are enriched in Au, Ag and Mn.
The neutral mine drainage system at Ľubietová in Slovakia is overwhelmingly dominated by copper (... more The neutral mine drainage system at Ľubietová in Slovakia is overwhelmingly dominated by copper (17 ppm in the most concentrated aqueous sample) and sulfate and almost devoid of iron (0.7 ppb in the most concentrated aqueous sample). This mine drainage is generated by oxidative dissolution of chalcopyrite (CuFeS 2), as confirmed by sulfur isotopes, and its neutral nature is maintained by buffering via the primary carbonates. The rich oxidation zone, composed of abundant libethenite (Cu 2 (PO 4)(OH)), pseudomalachite (Cu 5 (PO 4) 2 (OH) 4), and malachite (Cu 2 (CO 3)(OH) 2), appears to play only a passive and negligible role in the mine drainage generation. The copper-and sulfate-laden water is discharged through the lowermost adits in the ore field; inside the adits, blue gel covers the stream and converts slowly to crystalline langite (Cu 4 (SO 4)(OH) 6 •2H 2 O). X-ray absorption spectroscopy on Cu K edge showed that the local structure inside the gel is similar to that in langite. Calculation of saturation indices showed supersaturation with respect to sulfates (langite, brochantite (Cu 4 (SO 4)(OH) 6)), malachite, and copper arsenates and phosphates. Arsenates and phosphates were not found and do not form, probably because of kinetic hindrance. The solubility product of langite was estimated as log K sp = 17.73. Outside of the adits, transmission electron microscopy showed redox cycling of copper via the formation of nanocrystals of native copper on rock-forming sheet silicates. The copper concentrations are naturally attenuated, being reduced by a factor of 100 once the mine drainage reaches the Hutná river, about 1 km away from the discharge site. Sulfur isotopes document that no copper sulfides are precipitating; copper must be removed from the contaminated water in the form of sulfates or carbonates. The natural attenuation could be responsible for the enrichment of hyporheic sediments with copper whose mineralogy and geochemistry is unknown but its size is estimated to several metric tonnes of copper.
The hydrothermal veins in the area around the town of Dobšiná (Slovakia) are part of a complex Va... more The hydrothermal veins in the area around the town of Dobšiná (Slovakia) are part of a complex Variscan segment, and they host unique high grade Ni-Co-Fe-As ores. 23 samples have been studied in an attempt to describe and understand the complex phase relationships, chemical variability, and formation of the ore. Reflected light microscopy revealed the presence of gersdorffite, arsenopyrite, rammelsbergite, skutterudite, löllingite, native bismuth, as well as minor chalcopyrite and tetrahedrite. The micro-analytical investigation showed the existence of abundant intermediate sulfarsenide-sulfarsenide as well as sulfarsenidediarsenide phases. We have established the compositional ranges of these minerals, and have shown that formation of complex Ni-Co-Fe-sulfarsenides and arsenides are plausible at temperatures less than 200°C; further, that the uncritical use of experimental data in the Ni-Co-Fe-AsS system could lead to incorrect assumptions.
The disseminated copper mineralization is related to the Permi- an postvolcanic hydrothermal acti... more The disseminated copper mineralization is related to the Permi- an postvolcanic hydrothermal activity of basaltic volcanism. The association of minerals reflects composition of wall-rocks, as confirmed by the presence of Ni-Co minerals (siegenite, gersdorffite and carollite). The vein copper mineralization is associated with faults formed during the Alpine overthrust of the Hronicum Unit. These structures allowed the circulation of the hydrothermal fluids. More data are needed to explain the origin of these fluids. Me- tallic elements might be mobilized from disseminated precon- centrations, and subsequently transported and deposited into the structurally favourable milieu. Low temperature chalcopyrite, digenite, covellite, idaite, malachite, azurite, iron hydroxides, jarosite and gypsum repre- sent supergene association of minerals. Acknowledgement We thank ¼. Puškelová from Geological Institute of Slovak Academy of Sciences and D. Ozdín from Geological Survey of Slovak Republic fo...
Gold–sulphide ore from epithermal vein deposit Banská Hodruša consists of gold, electrum, galena,... more Gold–sulphide ore from epithermal vein deposit Banská Hodruša consists of gold, electrum, galena, sphalerite, chalcopyrite, and pyrite. Minor amounts of tellurides are present in the form of hessite, petzite and other rare Au sulphides and tellurides. Pyrite as a common product of hydrothermal alteration occurs mainly in the wall rock. Gangue minerals are represented by abundant quartz and adularia, clay minerals and carbonates. A combination of classical mineralogical methods – optical microscopy, electron microprobe, scanning electron microscopy, powder X-ray diffraction, automated mineralogy methods – QUEMSCAN RMS, TMS, PMA, and chemical analysis were used to determine composition of the head sample and individual ore dressing products, such as mineral jig concentrate, flotation concentrate and waste. The information about mineral composition of head sample, distribution of minerals in ore dressing products, their chemical composition and optimal grain size (P85–88 of 74 μm) has ...
The oldest model ages are similar showing high ^-values and age values around more than 600 Ma. T... more The oldest model ages are similar showing high ^-values and age values around more than 600 Ma. They are typical of polymetallic massive sulphide mineralizations with exception of the ore district Stubai-Ötzal. The main difference is the frequency of radiogenic lead (J-type), causing distinct inhomogenities and anomalous negative model ages. The radiogenic leads are the mobilizates of Alpidic metamorphism (30 and 80 Ma) in the Eastern and Western Alps. The Hercynian granite intrusion of the W. Carpathians have not been seized by the "Tauern crystallization. "The leads of the ore mineralizations connected with the young volcanism show relevant ages or are slightly radiogenic. In the Eastern Alps, strata bound Pb-Zn mineralizations have a tendency to model ages which are stratigraphically too old (B-type). Such a isotope composition is also evident for the Devonian Pb-Zn-Ag-Ba mineralization of the Graz Paleozoic (540-570 Ma) and for most of the Triassic Pb-Zn-(F-Ba)-deposit there are age differences of 150 to 200 Ma. In the Eastern Alps, the lead isotope data of the carbonate-hosted Pb-Zn-ore mineralizations show model ages 160-400 Ma. In the Western Carpathians, the Pbisotope data are comparable with the Alpine data or analogous with mineralizations from the Slovak neovolcanics. The ^-values vary from 8 to 10, corresponding to the average crust lead of the Hercynian granite complexes or to the thorogenic upper crust lead inherited from the pre-Cambrian clastic sedimentation. The comparison is limited to the carbonate-hosted Pb-Zn deposits in respect to the problematic of biogenic and abiogenic sulphate reduction. The sulphide S-isotopes depend on the contemporaneous isotopic composition of the sea water sulphate. Differences in the S-isotope distribution are found between Anisian and Carnian Pb-Znmineralizations confirming different temporal origins. Biogenic reduction processes are more typical in the Eastern Alps. In the Western Carpathians, the acceptance of biogenic sulphide formation is conceivable only for the deposits of Poniky and of the vein range Vysná Slaná. Ore mineralizations influenced by younger endogenic hydrothermal activities would be indicated by Pb-model ages around zero. The C-and O-isotope study show that the Permian magnesites in W. Carpathians are in an adequate position. The Carboniferous-hosted magnesites are characterized by Oisotopes. In both cases, the sedimentary origin cannot be drawn in doubt considering the other facts too. The present state of the knowledge about the origin of siderites is not sufficient in all. Recent sedimentary siderites are distinguishable clearly from those of deep seated veins or of a higher metamorphic environment. The siderites of the Rudnany deposit show affinity to the siderites of Erzberg. But the thermical history of the Erzberg is more complex. Roznava and "Penninic" (Tauern gold veins) seem to be genetically analogous. But, the siderites of the "Penninic" are formed at higher temperatures.
There are Ni-Co minerals occurring mainly in the hydrothermal siderite veins of Alpine age in the... more There are Ni-Co minerals occurring mainly in the hydrothermal siderite veins of Alpine age in the Western Carpathians. The mineral succession scheme is the following: alteration-> siderite-* alpine paragenesis-> Ni-Co-Fe-As minerals-* quartz with Cu-Bi-Fe-Sb-Hg sulphides. The most abundant are in the sulphide (sulphoarsenide, arsenide) stage with less contents of carbonates and silicates. There are often occurred with the Cu minerals-tetrahedrite, tennantite, chalcopyrite and with the others sulphides mainly pyrite and galena. Those were described on numerous deposits and occurrences in the Slovak Republic. Ni-Co-Fe-Cu-As minerals are represented by gersdorffite, cobaltite, arsenopyrite, rammelsbergite, pararammelsbergile, krutovite, ullmannite, skuttcruditc, nickeline and carrollite which were studied in details at the following localities: Vysna Boca, Dobsina and Casta.
The article present the comparison of the Pb-isotope study of antimony-ores from important Sbmine... more The article present the comparison of the Pb-isotope study of antimony-ores from important Sbmineralisation of Western Carpathian: from Tatric unit (Pezinok, Kuchyňa, Pernek, Dúbrava, Magurka, Lom, Trangoška, Jasenie, Kriváň deposits and occurrences), Gemeric unit (Helcmanovce, Grexa and Poproč deposits) and from Eastern Slovakian neovolcanites (Zlatá Baňa). The study is compared with results of previous investigations of affiliated galena mineralisation. The lead is of a crustal origine. The lead from Taric and that from Gemeric unit (and Eastern Slovakian Neovolcanites) seems to be derived from different reservoirs.
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