Pub Date : 2024-03-06DOI: 10.1134/s1075701523090040
V. V. Mikhailov, S. Yu. Stepanov, S. V. Petrov, R. S. Palamarchuk
Abstract
The paper presents the first data on the distribution and composition of copper–precious-metal mineralization in gabbroids of the Kumba intrusive (North Urals). The precious-metal mineralization is associated with digenite–bornite, bornite-chalcopyrite, and pyrite–chalcopyrite ores. Nine precious-metal minerals and their varieties were identified in amphibole and amphibole–olivine gabbro of the Kumba intrusive for the first time: native gold, Au–Ag alloys, Ag and Pd tellurides (hessite, merenskyite), Bi tellurides (kotulskite), antimonide–arsenides (isomertieite), arsenides (arsenopalladinite, sperrylite), and stannides (atokite) of Pt and Pd. Precious-metal minerals from all sulfide assemblages in heavy concentrates are often accompanied by antimonides (stibnite) and Bi mineralization represented mainly by native bismuth and bismuthinite and less common sulfotellurides (baksanite) and tellurides (tsumoite). Our results make it possible to estimate the prospects of the discovery of new copper–precious-metal deposits hosted in gabbro of the Uralian Platinum Belt. Taking into account the regularities of distribution of precious metal and copper mineralization, most gabbro massifs in the Uralian Platinum Belt can be considered the promising objects for searching the large-tonnage copper deposits with associated ore Au and Pd grades.
{"title":"Precious-Metal Mineralization in Gabbroids of the Kumba Intrusive, Uralian Platinum Belt (North Urals)","authors":"V. V. Mikhailov, S. Yu. Stepanov, S. V. Petrov, R. S. Palamarchuk","doi":"10.1134/s1075701523090040","DOIUrl":"https://doi.org/10.1134/s1075701523090040","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>The paper presents the first data on the distribution and composition of copper–precious-metal mineralization in gabbroids of the Kumba intrusive (North Urals). The precious-metal mineralization is associated with digenite–bornite, bornite-chalcopyrite, and pyrite–chalcopyrite ores. Nine precious-metal minerals and their varieties were identified in amphibole and amphibole–olivine gabbro of the Kumba intrusive for the first time: native gold, Au–Ag alloys, Ag and Pd tellurides (hessite, merenskyite), Bi tellurides (kotulskite), antimonide–arsenides (isomertieite), arsenides (arsenopalladinite, sperrylite), and stannides (atokite) of Pt and Pd. Precious-metal minerals from all sulfide assemblages in heavy concentrates are often accompanied by antimonides (stibnite) and Bi mineralization represented mainly by native bismuth and bismuthinite and less common sulfotellurides (baksanite) and tellurides (tsumoite). Our results make it possible to estimate the prospects of the discovery of new copper–precious-metal deposits hosted in gabbro of the Uralian Platinum Belt. Taking into account the regularities of distribution of precious metal and copper mineralization, most gabbro massifs in the Uralian Platinum Belt can be considered the promising objects for searching the large-tonnage copper deposits with associated ore Au and Pd grades.</p>","PeriodicalId":12719,"journal":{"name":"Geology of Ore Deposits","volume":"11 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2024-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140054887","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-03-06DOI: 10.1134/s1075701523090052
V. I. Popova, E. V. Belogub, M. A. Rassomakhin, V. A. Popov, P. V. Khvorov
Abstract
Mineral composition of chromitites and host serpentinites from a quarry at Mt. Poklonnaya of the Karabash serpentinite massif is studied using optical and electron microscopy. Along with previously known native osmium and laurite, eight minerals of platinum group elements (MPG) are found. Among them are isoferroplatinum, irarsite, iridium, naldrettite, cuproiridsite, sperrylite, tolovkite, and erlichmannite. It is found that magnesioalumochromite is an early magmatic Cr-spinel, while magnesiochromite and ferrichromite are late magmatic. The earliest native iridium and native osmium are replaced by platinum-group-elements sulfides, arsenides and stibnides. Magnesiochromite is associated with native gold, Ni chalcohenides (gersdorffite, millerite, pentlandite, heaslewoodite) and chalcopyrite. The formation of Cr-magnetite, magnetite, native iron, native nickel, galena, and barite is related to serpentinization. Carbonates (calcite and dolomite), brucite, andradite, sepiolite and an unidentified Ca-silicate formed at the latest stage of serpentinization. Secondary Ni minerals (gaspeite, nepuite, “garnierite”) are most likely products of the latest mineral-forming process.
{"title":"Mineralogy of Chromitites of Mount Poklonnaya of the Karabash Massif, South Urals","authors":"V. I. Popova, E. V. Belogub, M. A. Rassomakhin, V. A. Popov, P. V. Khvorov","doi":"10.1134/s1075701523090052","DOIUrl":"https://doi.org/10.1134/s1075701523090052","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>Mineral composition of chromitites and host serpentinites from a quarry at Mt. Poklonnaya of the Karabash serpentinite massif is studied using optical and electron microscopy. Along with previously known native osmium and laurite, eight minerals of platinum group elements (MPG) are found. Among them are isoferroplatinum, irarsite, iridium, naldrettite, cuproiridsite, sperrylite, tolovkite, and erlichmannite. It is found that magnesioalumochromite is an early magmatic Cr-spinel, while magnesiochromite and ferrichromite are late magmatic. The earliest native iridium and native osmium are replaced by platinum-group-elements sulfides, arsenides and stibnides. Magnesiochromite is associated with native gold, Ni chalcohenides (gersdorffite, millerite, pentlandite, heaslewoodite) and chalcopyrite. The formation of Cr-magnetite, magnetite, native iron, native nickel, galena, and barite is related to serpentinization. Carbonates (calcite and dolomite), brucite, andradite, sepiolite and an unidentified Ca-silicate formed at the latest stage of serpentinization. Secondary Ni minerals (gaspeite, nepuite, “garnierite”) are most likely products of the latest mineral-forming process.</p>","PeriodicalId":12719,"journal":{"name":"Geology of Ore Deposits","volume":"5 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2024-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140054806","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-03-06DOI: 10.1134/s1075701523070188
R. V. Kuzhuget, N. N. Ankusheva, A. K. Khertek, A. O. Mongush, Yu. V. Butanaeva
Abstract
Ore mineralization of the Ak-Sug Porphyry Copper–Gold–Molybdenum deposit formed during three stages: 1) porphyry-copper mineralization with simple sulfides in quartz–sericite and quartz–sericite–chlorite metasomatites, 2) subepithermal Au–Bi–Te–Pd-quartz mineralization in quartz–sericite metasomatites, and 3) intermediate-sulfidation Au–Ag mineral assemblages with selenides, tellurides, and Sb and As sulfosalts in argillisites. Fluid inclusion studies (microthermometry, Raman spectroscopy) of quartz and mineral thermometry (an assemblage of Au and Ag tellurides) showed that porphyry copper and subepithermal mineralization precipitated from hydrocarbon–aqueous–chloride (Na–K ± Fe) fluid with salinity of 20.1–32.8 wt % NaCl eq. at 435–375°C and hydrocarbon–aqueous–chloride (Na–K ± Fe ± Ca ± Mg) fluid with salinity of 7.5–15.0 wt % NaCl eq. at 415–325°C, respectively. The epithermal mineral assemblages precipitated at ∼0.55 kbar from hydrocarbon–aqueous–chloride (Na–K ± Fe ± Ca ± Mg) fluid with salinity of 1.4–12.6 wt % NaCl eq. at 370–200°C. The latest low-temperature (240–190°С) and diluted (3.5–4.9 wt %) fluids are characterized by variations in Na and K chlorides; Fe2+, Fe3+, Ca, and Mg carbonates; and Na, K, and Mg sulfates. The S isotopic composition of the fluid of different mineral assemblages varies from –2.7 to +0.3‰ and suggest that they are derivatives of a single porphyry system. The δ18О values of the fluid of porphyry copper (7.4‰) and subepithermal (7.0‰) stages indicate its magmatic genesis, whereas those of the epithermal stage (from +1.2 to +7.2‰) are evident of mixing of magmatic fluid and meteoric waters (from +0.4 to +5.7‰). Our isotopic data, combined with mineralogical–geochemical peculiarities and formation conditions of ores, provide tracing the principles of the evolution of mineral assemblages, temperatures, composition, and fluid salinity at the Ak-Sug deposit upon the transition from porphyry copper to epithermal stage.
摘要 Ak-Sug 斑岩铜金钼矿床的矿石成矿过程分为三个阶段：1）斑岩型铜矿化，在石英-绿泥石和石英-绿泥石-绿帘石变质岩中形成简单的硫化物；2）亚热液型金-铋-碲-钯-石英矿化，在石英-绿泥石变质岩中形成；3）中硫化型金-银矿物组合，在绿帘石中形成硒化物、碲化物以及锑和砷硫化物。对石英和矿物热度（金银碲化物集合体）进行的流体包裹体研究（微测温、拉曼光谱）表明，斑岩铜矿和次热液矿化是从含盐量为 20.1-32.8 wt % 的氯化钠当量（435-375°C）和含盐量为 7.5-15.0 wt % 的氯化钠当量（415-325°C）的烃水氯化物（Na-K ± Fe ± Ca ± Mg）流体中析出。热液矿物集合体是在∼0.55千巴时，从盐度为1.4-12.6 wt % NaCl当量、温度为370-200°C的碳氢-水-氯化物（Na-K ± Fe ± Ca ± Mg）流体中沉淀出来的。最新的低温（240-190°С）和稀释（3.5-4.9 wt %）流体的特征是Na和K氯化物；Fe2+、Fe3+、Ca和Mg碳酸盐；以及Na、K和Mg硫酸盐的变化。不同矿物组合流体的 S 同位素组成在 -2.7 至 +0.3‰ 之间变化，表明它们是单一斑岩系统的衍生物。斑岩铜矿阶段（7.4‰）和次表热阶段（7.0‰）流体的δ18О值表明其岩浆成因，而表热阶段（从+1.2到+7.2‰）流体的δ18О值则表明岩浆流体和流星水（从+0.4到+5.7‰）的混合。我们的同位素数据与矿石的矿物学地球化学特征和形成条件相结合，为阿克苏格矿床的矿物组合、温度、成分和流体盐度从斑岩铜矿过渡到表生铜矿阶段的演变原理提供了依据。
{"title":"The Ak-Sug Porphyry Copper–Gold–Molybdenum Deposit, East Sayan: Noble Metal Mineralization, PT-Parameters, and Composition of Ore-Bearing Fluid","authors":"R. V. Kuzhuget, N. N. Ankusheva, A. K. Khertek, A. O. Mongush, Yu. V. Butanaeva","doi":"10.1134/s1075701523070188","DOIUrl":"https://doi.org/10.1134/s1075701523070188","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>Ore mineralization of the Ak-Sug Porphyry Copper–Gold–Molybdenum deposit formed during three stages: 1) porphyry-copper mineralization with simple sulfides in quartz–sericite and quartz–sericite–chlorite metasomatites, 2) subepithermal Au–Bi–Te–Pd-quartz mineralization in quartz–sericite metasomatites, and 3) intermediate-sulfidation Au–Ag mineral assemblages with selenides, tellurides, and Sb and As sulfosalts in argillisites. Fluid inclusion studies (microthermometry, Raman spectroscopy) of quartz and mineral thermometry (an assemblage of Au and Ag tellurides) showed that porphyry copper and subepithermal mineralization precipitated from hydrocarbon–aqueous–chloride (Na–K ± Fe) fluid with salinity of 20.1–32.8 wt % NaCl eq. at 435–375°C and hydrocarbon–aqueous–chloride (Na–K ± Fe ± Ca ± Mg) fluid with salinity of 7.5–15.0 wt % NaCl eq. at 415–325°C, respectively. The epithermal mineral assemblages precipitated at ∼0.55 kbar from hydrocarbon–aqueous–chloride (Na–K ± Fe ± Ca ± Mg) fluid with salinity of 1.4–12.6 wt % NaCl eq. at 370–200°C. The latest low-temperature (240–190°С) and diluted (3.5–4.9 wt %) fluids are characterized by variations in Na and K chlorides; Fe<sup>2+</sup>, Fe<sup>3+</sup>, Ca, and Mg carbonates; and Na, K, and Mg sulfates. The S isotopic composition of the fluid of different mineral assemblages varies from –2.7 to +0.3‰ and suggest that they are derivatives of a single porphyry system. The δ<sup>18</sup>О values of the fluid of porphyry copper (7.4‰) and subepithermal (7.0‰) stages indicate its magmatic genesis, whereas those of the epithermal stage (from +1.2 to +7.2‰) are evident of mixing of magmatic fluid and meteoric waters (from +0.4 to +5.7‰). Our isotopic data, combined with mineralogical–geochemical peculiarities and formation conditions of ores, provide tracing the principles of the evolution of mineral assemblages, temperatures, composition, and fluid salinity at the Ak-Sug deposit upon the transition from porphyry copper to epithermal stage.</p>","PeriodicalId":12719,"journal":{"name":"Geology of Ore Deposits","volume":"252 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2024-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140881473","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-03-06DOI: 10.1134/s1075701523090076
A. V. Tolstov, V. G. Cherenkov, L. N. Baranov
Abstract
In the northeast of the Siberian Platform (Republic of Sakha (Yakutia)), there is the Udzha province of alkaline ultrabasic massifs with carbonatites of the final phases of the evolution of the magmatic system, forming its central “carbonatite core” and containing increased concentrations of Fe, Al, P, and a complex of rare and rare-earth elements. The massifs have a lateritic weathering crust with a thickness of up to 400 m. In the weathering crust of carbonatites, the contents of phosphates, Nb, Y, Sc, and TR are significantly higher compared to unaltered rock varieties. However, they reach maximal values in the thickness of peculiar sedimentary deposits formed as a result of the deposition of products denudation of the crust of ore-bearing carbonatites in small lake depressions and their intensive chemogenic transformation in a hot humid climate. They are uniquely rich ores, which in terms of the set and content of useful components have no analogues in world practice. These rocks are sometimes their natural concentrates with average contents of Nb2O5 7.21%, Y2O3 0.578%, Sc2O3 0.045%, and TR2O3 10.16%. The rocks that make up the ore-bearing stratum have characteristic features of sedimentary genesis: well-defined layered texture and facies zoning, as well as the presence of carbonized plant detritus and bacteriomorphic aggregates. This gives grounds to consider the complex of these formations as an independent stratigraphic unit—the Tomtor strata. Geological data suggest that it was formed in the range of 340–280 My. The Tomtor strata can serve as an important search criterion when searching for rare and rare-earth elements.
{"title":"Genesis and Age of the Ore Thickness of the Tomtor Deposit of Niobium and Rare-Earth Elements (Northeast Siberian Platform)","authors":"A. V. Tolstov, V. G. Cherenkov, L. N. Baranov","doi":"10.1134/s1075701523090076","DOIUrl":"https://doi.org/10.1134/s1075701523090076","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>In the northeast of the Siberian Platform (Republic of Sakha (Yakutia)), there is the Udzha province of alkaline ultrabasic massifs with carbonatites of the final phases of the evolution of the magmatic system, forming its central “carbonatite core” and containing increased concentrations of Fe, Al, P, and a complex of rare and rare-earth elements. The massifs have a lateritic weathering crust with a thickness of up to 400 m. In the weathering crust of carbonatites, the contents of phosphates, Nb, Y, Sc, and TR are significantly higher compared to unaltered rock varieties. However, they reach maximal values in the thickness of peculiar sedimentary deposits formed as a result of the deposition of products denudation of the crust of ore-bearing carbonatites in small lake depressions and their intensive chemogenic transformation in a hot humid climate. They are uniquely rich ores, which in terms of the set and content of useful components have no analogues in world practice. These rocks are sometimes their natural concentrates with average contents of Nb<sub>2</sub>O<sub>5</sub> 7.21%, Y<sub>2</sub>O<sub>3</sub> 0.578%, Sc<sub>2</sub>O<sub>3</sub> 0.045%, and TR<sub>2</sub>O<sub>3</sub> 10.16%. The rocks that make up the ore-bearing stratum have characteristic features of sedimentary genesis: well-defined layered texture and facies zoning, as well as the presence of carbonized plant detritus and bacteriomorphic aggregates. This gives grounds to consider the complex of these formations as an independent stratigraphic unit—the Tomtor strata. Geological data suggest that it was formed in the range of 340–280 My. The Tomtor strata can serve as an important search criterion when searching for rare and rare-earth elements.</p>","PeriodicalId":12719,"journal":{"name":"Geology of Ore Deposits","volume":"46 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2024-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140881726","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-03-06DOI: 10.1134/s107570152307022x
E. N. Sokolova, S. Z. Smirnov, V. S. Sekisova, N. S. Bortnikov, N. V. Gorelikova, V. G. Thomas
Abstract
Inclusions of the mineral-forming media in quartz of the Vysokogorskoe deposit are studied in detail. The compositions of the melts correspond to peraluminous potassium granites of normal alkalinity, depleted in rare alkalis, F, and Cl. The water content in the melts reached 7–9 wt %; CO2 and CH4 were also important in mineralizing fluids. Quartz crystallized at 620–650°C. Assemblages of four types have been identified as primary fluid inclusions: (1) inclusions of carbonate or sulfate aqueous solutions coexisting with melt inclusions, (2) low-density vapor-dominated primarily magmatic inclusions, (3) presumably postmagmatic low-salinity aqueous and vapor-dominated inclusions, and (4) multiphase fluid inclusions associated with vapor-dominated ones also formed at the postmagmatic stage. Daughter pyrosmalite–(Fe) and hibbingite, which was found for the first time in inclusions from quartz of the Vysokogorskoe deposit, made it possible to characterize the solutions as high-salinity chloride Na/K and Fe2+. Presumably, those solutions may have been the most efficient in Sn transport during the formation of fluid–explosive breccias and vein mineralization of the Vysokogorskoe deposit. The magma chamber itself most likely served as a heat source and, to a large extent, a source of aqueous fluid for the hydrothermal system of the deposit.
{"title":"Magmatic–Fluid System of the Vysokogorskoe Porphyry Tin Deposit (Sikhote-Alin, Kavalerovo Ore District, Primorsky Krai, Russia): a Magmatic Stage","authors":"E. N. Sokolova, S. Z. Smirnov, V. S. Sekisova, N. S. Bortnikov, N. V. Gorelikova, V. G. Thomas","doi":"10.1134/s107570152307022x","DOIUrl":"https://doi.org/10.1134/s107570152307022x","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>Inclusions of the mineral-forming media in quartz of the Vysokogorskoe deposit are studied in detail. The compositions of the melts correspond to peraluminous potassium granites of normal alkalinity, depleted in rare alkalis, F, and Cl. The water content in the melts reached 7–9 wt %; CO<sub>2</sub> and CH<sub>4</sub> were also important in mineralizing fluids. Quartz crystallized at 620–650°C. Assemblages of four types have been identified as primary fluid inclusions: (1) inclusions of carbonate or sulfate aqueous solutions coexisting with melt inclusions, (2) low-density vapor-dominated primarily magmatic inclusions, (3) presumably postmagmatic low-salinity aqueous and vapor-dominated inclusions, and (4) multiphase fluid inclusions associated with vapor-dominated ones also formed at the postmagmatic stage. Daughter pyrosmalite–(Fe) and hibbingite, which was found for the first time in inclusions from quartz of the Vysokogorskoe deposit, made it possible to characterize the solutions as high-salinity chloride Na/K and Fe<sup>2+</sup>. Presumably, those solutions may have been the most efficient in Sn transport during the formation of fluid–explosive breccias and vein mineralization of the Vysokogorskoe deposit. The magma chamber itself most likely served as a heat source and, to a large extent, a source of aqueous fluid for the hydrothermal system of the deposit.</p>","PeriodicalId":12719,"journal":{"name":"Geology of Ore Deposits","volume":"12 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2024-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140881464","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-03-06DOI: 10.1134/s1075701523070206
O. Yu. Plotinskaya, E. V. Kovalchuk
Abstract
The typomorpic features of the minerals of the fahlore group from three porphyry deposits of the Urals: the Mikheevskoe and Tomino porphyry copper deposits (the Southern Urals) and Talitsa porphyry Mo deposit (the Middle Urals) are studied. In the deposits studied, the fahlore- group minerals belong either to late mineral assemblages of the porphyry stage or to subepithermal veins. They vary in composition from tennantite to tetrahedrite with variable Fe and Zn contents. Contents of Cd, Co, Te, Bi, Ag, and Se are usually insignificant. However, an exception is fahlore of late generation from the Mikheevskoe deposit, which is represented by argentotetrahedrite–(Fe) and fahlore associated with bornite from the Tomino deposit, which corresponds to tennantite–tetrahedrite–(Cd) in composition. Most of the studied fahlore-group minerals are not characterized by complicated chemical zoning: they are either homogeneous or comprise a homogeneous core of intermediate tennantite–tetrahedrite composition and a rim with a dominating tetrahedrite end member. This evidences a relatively quiet deposition environment with no sharp variations of physicochemical parameters of ore-forming fluid, which in general is typical of porphyry deposits. Comparison with published data shows that the studied fahlores are similar in composition to those from “transitional” subepithermal mineralization.
{"title":"Fahlores from Porphyry Cu–(Mo) Deposits of the Urals","authors":"O. Yu. Plotinskaya, E. V. Kovalchuk","doi":"10.1134/s1075701523070206","DOIUrl":"https://doi.org/10.1134/s1075701523070206","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>The typomorpic features of the minerals of the fahlore group from three porphyry deposits of the Urals: the Mikheevskoe and Tomino porphyry copper deposits (the Southern Urals) and Talitsa porphyry Mo deposit (the Middle Urals) are studied. In the deposits studied, the fahlore- group minerals belong either to late mineral assemblages of the porphyry stage or to subepithermal veins. They vary in composition from tennantite to tetrahedrite with variable Fe and Zn contents. Contents of Cd, Co, Te, Bi, Ag, and Se are usually insignificant. However, an exception is fahlore of late generation from the Mikheevskoe deposit, which is represented by argentotetrahedrite–(Fe) and fahlore associated with bornite from the Tomino deposit, which corresponds to tennantite–tetrahedrite–(Cd) in composition. Most of the studied fahlore-group minerals are not characterized by complicated chemical zoning: they are either homogeneous or comprise a homogeneous core of intermediate tennantite–tetrahedrite composition and a rim with a dominating tetrahedrite end member. This evidences a relatively quiet deposition environment with no sharp variations of physicochemical parameters of ore-forming fluid, which in general is typical of porphyry deposits. Comparison with published data shows that the studied fahlores are similar in composition to those from “transitional” subepithermal mineralization.</p>","PeriodicalId":12719,"journal":{"name":"Geology of Ore Deposits","volume":"24 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2024-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140881331","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-03-06DOI: 10.1134/s107570152307019x
O. V. Petrov, V. V. Shatov, A. I. Khanchuk, V. V. Ivanov, Yu. P. Zmievsky, V. I. Shpikerman, E. O. Petrov, V. V. Snezhko, A. V. Shmanyak, A. V. Molchanov, V. O. Khalenev, N. V. Shatova, N.V. Rodionov, B. V. Belyatsky, S. A. Sergeev
Abstract
In this paper, we discuss new data obtained by petrographical, geochemical, geochronological, and isotopic–geochemical study of magmatic rocks within the Malmyzh and Gion gold–copper-porphyry ore fields. Geochronological data show a Late Cretaceous age of their magmatic crystallization: Cenomanian (97–99 Ma) and Campanian (76–82 Ma) ages, respectively. Based on a comparative analysis of the studied samples igneous rocks with each other and with magmatic rocks of worldwide porphyry deposits, the results of a study using a secondary ion mass spectrometer of the patterns of distribution of trace elements (REE + Y, Hf, Ti, U, Th, and Pb) in accessory zircons from igneous rocks of the Malmyzh and Gion ore fields are discussed in order to estimate their potential ore content in the gold–copper-porphyry mineralization. Despite the fact that economic gold–copper ore mineralization within the potential Gion ore field was previously unknown, an analysis of the results shows, that according to the obtained values of indicative geochemical parameters of accessory zircons, the granitoids involved in its geological structure practically do not differ from the granitoids of both the neighboring Malmyzh deposit and most of the worldwide porphyry gold–copper deposits.
{"title":"Revealing Prospects of New Gold–Copper-Porphyry Deposits of the Malmyzh Type in the Lower Amur Region (Russian Far East)","authors":"O. V. Petrov, V. V. Shatov, A. I. Khanchuk, V. V. Ivanov, Yu. P. Zmievsky, V. I. Shpikerman, E. O. Petrov, V. V. Snezhko, A. V. Shmanyak, A. V. Molchanov, V. O. Khalenev, N. V. Shatova, N.V. Rodionov, B. V. Belyatsky, S. A. Sergeev","doi":"10.1134/s107570152307019x","DOIUrl":"https://doi.org/10.1134/s107570152307019x","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>In this paper, we discuss new data obtained by petrographical, geochemical, geochronological, and isotopic–geochemical study of magmatic rocks within the Malmyzh and Gion gold–copper-porphyry ore fields. Geochronological data show a Late Cretaceous age of their magmatic crystallization: Cenomanian (97–99 Ma) and Campanian (76–82 Ma) ages, respectively. Based on a comparative analysis of the studied samples igneous rocks with each other and with magmatic rocks of worldwide porphyry deposits, the results of a study using a secondary ion mass spectrometer of the patterns of distribution of trace elements (REE + Y, Hf, Ti, U, Th, and Pb) in accessory zircons from igneous rocks of the Malmyzh and Gion ore fields are discussed in order to estimate their potential ore content in the gold–copper-porphyry mineralization. Despite the fact that economic gold–copper ore mineralization within the potential Gion ore field was previously unknown, an analysis of the results shows, that according to the obtained values of indicative geochemical parameters of accessory zircons, the granitoids involved in its geological structure practically do not differ from the granitoids of both the neighboring Malmyzh deposit and most of the worldwide porphyry gold–copper deposits.</p>","PeriodicalId":12719,"journal":{"name":"Geology of Ore Deposits","volume":"107 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2024-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140881549","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-03-06DOI: 10.1134/s1075701523070243
G. A. Yurgenson, G. D. Kiseleva, A. A. Dolomanova-Topol, V. A. Kovalenker, V. A. Petrov, Yu. I. Yazykova, L. A. Levitskaya, N. V. Trubkin, V. I. Taskaev, O. B. Karimova
Abstract
The results of a comprehensive detailed study of the vein structure, mineral zoning of veins, and mineral typomorphism of the Shakhtama deposit obtained on the basis of new samples from poorly studied horizons are given. The results obtained show that the Mo resources of the deposit are far from being exhausted, and the typomorphic features of ore minerals indicate that base metal mineralization associated with Au (Ag), also continues to a depth, along with Mo. The presence of rare Sr mineral, svanbergite, in the Shakhtamа deposit and the typomorphic properties of ore minerals testify in favor of the near-surface origin of the exposed mineralization. The succession of mineral formation has been established. Based on the study of ore and metasomatic zonality, fluid inclusions and isotopic data, as well as the composition of structural impurities in molybdenite, conclusions were made of the formation conditions of ore mineralization in a porphyry ore-forming system.
{"title":"Structure, Mineralogical, and Geochemical Features and Formation Conditions of Ore Veins in the Mo Porphyry Shakhtama Deposit (Eastern Transbaikalia)","authors":"G. A. Yurgenson, G. D. Kiseleva, A. A. Dolomanova-Topol, V. A. Kovalenker, V. A. Petrov, Yu. I. Yazykova, L. A. Levitskaya, N. V. Trubkin, V. I. Taskaev, O. B. Karimova","doi":"10.1134/s1075701523070243","DOIUrl":"https://doi.org/10.1134/s1075701523070243","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>The results of a comprehensive detailed study of the vein structure, mineral zoning of veins, and mineral typomorphism of the Shakhtama deposit obtained on the basis of new samples from poorly studied horizons are given. The results obtained show that the Mo resources of the deposit are far from being exhausted, and the typomorphic features of ore minerals indicate that base metal mineralization associated with Au (Ag), also continues to a depth, along with Mo. The presence of rare Sr mineral, svanbergite, in the Shakhtamа deposit and the typomorphic properties of ore minerals testify in favor of the near-surface origin of the exposed mineralization. The succession of mineral formation has been established. Based on the study of ore and metasomatic zonality, fluid inclusions and isotopic data, as well as the composition of structural impurities in molybdenite, conclusions were made of the formation conditions of ore mineralization in a porphyry ore-forming system.</p>","PeriodicalId":12719,"journal":{"name":"Geology of Ore Deposits","volume":"68 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2024-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140881390","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-03-06DOI: 10.1134/s1075701523090064
D. A. Rogov, E. V. Belogub, K. A. Novoselov, M. A. Rassomakhin, R. R. Irmakov, A. E. Chugaev
Abstract
Ore hand specimens and technological ore samples from the greisen-type Porokhovskoe and Yugo-Konevskoe tungsten deposits in the Southern Urals were studied. The major tungsten minerals in primary ores of both deposits are hübnerite and scheelite. Secondary and accessory minerals are pyrite, chalcopyrite and molybdenite; rare minerals are sphalerite, galena, bismuthinite, aikinite, unidentified Bi chalcogenides and sulfosalts, magnetite, rutile, ilmenite, titanite, and columbite. Veins are mainly composed by quartz–muscovite aggregate with secondary (calcite, dolomite, and fluorite), minor (chlorite and amphibole), and accessory (zircon, apatite, and uraninite). No distinct zonation in the distribution pattern of wolframite with varying Fe content relative to the Yugo-Konevsky granite pluton is identified. However, wolframites from the Northern area of the Porokhovskoe deposit are enriched in Fe compared to those from the Central area and Yugo-Konevskoe deposit. Along with through vein wolframite and scheelite, the oxidized ores also contain Fe and Mn oxyhydroxides, malachite, pyromorphite, and bromargyrite. Tungsten enters the composition of Mn and Fe oxyhydroxides, which replace wolframite and less often sulfides. The WO3 content in pseudomorphs of Mn and Fe oxyhydroxides after hübnerite reaches 18 wt %. Single grains of stolzite and russellite are found. According to the results of phase chemical analysis of technological samples, the amount of tungstite in oxidized ores is minor. Due to this, all ores of both deposits can be ascribed to primary technological type.
{"title":"Mineral Forms of Tungsten at the Porokhovskoe and Yugo-Konevskoe Deposits (Southern Urals)","authors":"D. A. Rogov, E. V. Belogub, K. A. Novoselov, M. A. Rassomakhin, R. R. Irmakov, A. E. Chugaev","doi":"10.1134/s1075701523090064","DOIUrl":"https://doi.org/10.1134/s1075701523090064","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>Ore hand specimens and technological ore samples from the greisen-type Porokhovskoe and Yugo-Konevskoe tungsten deposits in the Southern Urals were studied. The major tungsten minerals in primary ores of both deposits are hübnerite and scheelite. Secondary and accessory minerals are pyrite, chalcopyrite and molybdenite; rare minerals are sphalerite, galena, bismuthinite, aikinite, unidentified Bi chalcogenides and sulfosalts, magnetite, rutile, ilmenite, titanite, and columbite. Veins are mainly composed by quartz–muscovite aggregate with secondary (calcite, dolomite, and fluorite), minor (chlorite and amphibole), and accessory (zircon, apatite, and uraninite). No distinct zonation in the distribution pattern of wolframite with varying Fe content relative to the Yugo-Konevsky granite pluton is identified. However, wolframites from the Northern area of the Porokhovskoe deposit are enriched in Fe compared to those from the Central area and Yugo-Konevskoe deposit. Along with through vein wolframite and scheelite, the oxidized ores also contain Fe and Mn oxyhydroxides, malachite, pyromorphite, and bromargyrite. Tungsten enters the composition of Mn and Fe oxyhydroxides, which replace wolframite and less often sulfides. The WO<sub>3</sub> content in pseudomorphs of Mn and Fe oxyhydroxides after hübnerite reaches 18 wt %. Single grains of stolzite and russellite are found. According to the results of phase chemical analysis of technological samples, the amount of tungstite in oxidized ores is minor. Due to this, all ores of both deposits can be ascribed to primary technological type.</p>","PeriodicalId":12719,"journal":{"name":"Geology of Ore Deposits","volume":"27 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2024-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140881702","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-02-08DOI: 10.1134/s1075701523080044
Yu. V. Erokhin, A. V. Zakharov, V. S. Ponomarev, D. A. Petrov, S. Yu. Kropantsev
Abstract
The mineralogy of olivine veins from the Itkul hyperbasite massif, Southern Urals, has been studied. These veins are composed of forsterite with minor talc, magnetite, and magnesite. Itkul olivine, which was first described in 1847 as a new mineral—glinkite—is forsterite with a fayalite content of 16.5%. It has been established that the metasomatic olivinites of these veins were formed due to recrystallization of host serpentinite under the influence of a nearby granite intrusion. It is suggested that, because of the visual similarity of Itkul forsterite with Ural demantoid, the latter were for a long time called “chrysolites” or “Ural chrysolites.”
{"title":"Forsterite from the Itkul Hyperbasite Massif, Southern Urals; or, Once Again about Glinkite","authors":"Yu. V. Erokhin, A. V. Zakharov, V. S. Ponomarev, D. A. Petrov, S. Yu. Kropantsev","doi":"10.1134/s1075701523080044","DOIUrl":"https://doi.org/10.1134/s1075701523080044","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>The mineralogy of olivine veins from the Itkul hyperbasite massif, Southern Urals, has been studied. These veins are composed of forsterite with minor talc, magnetite, and magnesite. Itkul olivine, which was first described in 1847 as a new mineral—glinkite—is forsterite with a fayalite content of 16.5%. It has been established that the metasomatic olivinites of these veins were formed due to recrystallization of host serpentinite under the influence of a nearby granite intrusion. It is suggested that, because of the visual similarity of Itkul forsterite with Ural demantoid, the latter were for a long time called “chrysolites” or “Ural chrysolites.”</p>","PeriodicalId":12719,"journal":{"name":"Geology of Ore Deposits","volume":"29 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2024-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139763080","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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