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":null,"pages":null},"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":null,"pages":null},"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":null,"pages":null},"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":null,"pages":null},"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":null,"pages":null},"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}
Pub Date : 2024-02-08DOI: 10.1134/s107570152308007x
T. A. Gornostaeva, A. V. Mokhov, P. M. Kartashov, K. V. Lobanov
Abstract
Native cobalt was found in amphibolite of the Kola superdeep borehole (SG-3) from a depth of 9630 m by a complex of local analytical methods (analytical scanning electron microscopy, electron backscatter diffraction). The studied amphibolite is a fine-grained melanocratic rock composed mainly of magnesioferri- hornblende and containing accessory native metal, telluride, sulphotelluride, and sulphide (Au, Ag, Pd, Bi, Cu, Pb, Zn, Sb, and Fe) mineralization.It also includes the clinopyroxene xenoclast carrying a fundamentally different set of accessories—poor in sulphides and including native cobalt. The absence of significant impurities, including iron, in native cobalt and its belonging to the hexagonal α-modification was determined. It is shown, that the metallic cobalt particles exposed during ion polishing of a compact pyroxene matrix cannot be a contaminant, introduced into the sample during drilling and sample preparation. Cobalt, obviously, was formed not only before the stage of retrograde metamorphism and subsequent hydrothermal processing of the amphibolite containing it, but probably long before the formation of the sedimentary protolith of this rock. That is, native cobalt belongs to the early high-temperature mineral phases inherited from the older Proterozoic—Archean main volcanism, while the time of formation of this layer of amphibolites dates back to the age of 2.4 billion years—the Early Karelian era of the Proterozoic.
{"title":"Native Cobalt in Deep Levels of the Kola Superdeep Borehole","authors":"T. A. Gornostaeva, A. V. Mokhov, P. M. Kartashov, K. V. Lobanov","doi":"10.1134/s107570152308007x","DOIUrl":"https://doi.org/10.1134/s107570152308007x","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>Native cobalt was found in amphibolite of the Kola superdeep borehole (SG-3) from a depth of 9630 m by a complex of local analytical methods (analytical scanning electron microscopy, electron backscatter diffraction). The studied amphibolite is a fine-grained melanocratic rock composed mainly of magnesioferri- hornblende and containing accessory native metal, telluride, sulphotelluride, and sulphide (Au, Ag, Pd, Bi, Cu, Pb, Zn, Sb, and Fe) mineralization.It also includes the clinopyroxene xenoclast carrying a fundamentally different set of accessories—poor in sulphides and including native cobalt. The absence of significant impurities, including iron, in native cobalt and its belonging to the hexagonal α-modification was determined. It is shown, that the metallic cobalt particles exposed during ion polishing of a compact pyroxene matrix cannot be a contaminant, introduced into the sample during drilling and sample preparation. Cobalt, obviously, was formed not only before the stage of retrograde metamorphism and subsequent hydrothermal processing of the amphibolite containing it, but probably long before the formation of the sedimentary protolith of this rock. That is, native cobalt belongs to the early high-temperature mineral phases inherited from the older Proterozoic—Archean main volcanism, while the time of formation of this layer of amphibolites dates back to the age of 2.4 billion years—the Early Karelian era of the Proterozoic.</p>","PeriodicalId":12719,"journal":{"name":"Geology of Ore Deposits","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2024-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140881718","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/s1075701523080081
N. I. Ponomareva, V. V. Gordienko, N. O. Melyantsov
Abstract
Study data on dark-colored, bright, and pale pink tourmalines of rare-metal pegmatites from Mt. Okhmylk in the Voron’ya Tundra region are reported. Chemical compositions and parameters of elementary cells are determined for tourmalines. Dark-colored tourmaline I is schörl–olenite, and pink tourmaline corresponds to elbaite–olenite. Studied tourmalines and tourmalines from spodumene pegmatites of other regions are compared. Based on the rare-earth element distribution in tourmalines, they are suggested to have been formed with involvement of high-temperature postmagmatic solutions. Mineral inclusions in schörl–olenite are represented by biotite and magnetite. Mineral inclusions in elbaite–olenite are cassiterite, pollucite, apatite, and tantalite. Tantalite is characterized by higher tantalum and low niobium. In addition, pure manganotantalite is often present in elbaite–olenite, and simpsonite is always observed at contacts between tantalite inclusions and tourmaline. All these data are indicative that albite–spodumene pegmatites of this region were formed with an active role of metasomatic processes.
摘要报告了沃龙亚苔原地区奥赫米尔克山稀有金属伟晶岩中深色、明亮和淡粉色电气石的研究数据。报告确定了碧玺的化学成分和基本单元参数。深色電氣石 I 是雪橄橄欖石，而粉紅色電氣石則是埃爾白橄欖石。研究中的电气石和来自其他地区磷灰石伟晶岩的电气石进行了比较。根据电气石中稀土元素的分布，认为它们是在高温后熔岩溶液的参与下形成的。辉绿岩中的矿物包裹体以生物铁和磁铁矿为代表。埃尔白橄榄石中的矿物包裹体有锡石、辉石、磷灰石和钽铁矿。钽铁矿的特点是钽含量较高而铌含量较低。此外，在埃尔白橄榄石中经常出现纯锰钽铁矿，在钽铁矿包裹体与电气石的接触处总是能观察到矽卡岩。所有这些数据都表明，该地区的白云石-黝帘石伟晶岩是在元成岩过程中形成的。
{"title":"Tourmaline Supergroup Minerals from Rare-Metal Pegmatites of the Voron’ya Tundra (Kola Peninsula, Russia)","authors":"N. I. Ponomareva, V. V. Gordienko, N. O. Melyantsov","doi":"10.1134/s1075701523080081","DOIUrl":"https://doi.org/10.1134/s1075701523080081","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>Study data on dark-colored, bright, and pale pink tourmalines of rare-metal pegmatites from Mt. Okhmylk in the Voron’ya Tundra region are reported. Chemical compositions and parameters of elementary cells are determined for tourmalines. Dark-colored tourmaline I is schörl–olenite, and pink tourmaline corresponds to elbaite–olenite. Studied tourmalines and tourmalines from spodumene pegmatites of other regions are compared. Based on the rare-earth element distribution in tourmalines, they are suggested to have been formed with involvement of high-temperature postmagmatic solutions. Mineral inclusions in schörl–olenite are represented by biotite and magnetite. Mineral inclusions in elbaite–olenite are cassiterite, pollucite, apatite, and tantalite. Tantalite is characterized by higher tantalum and low niobium. In addition, pure manganotantalite is often present in elbaite–olenite, and simpsonite is always observed at contacts between tantalite inclusions and tourmaline. All these data are indicative that albite–spodumene pegmatites of this region were formed with an active role of metasomatic processes.</p>","PeriodicalId":12719,"journal":{"name":"Geology of Ore Deposits","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2024-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139762988","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/s107570152308010x
A. B. Vrevsky
Abstract
This paper presents the data on the structure and composition of a concentric-zonal komatiite pillow from the Ruvinvaar Formation of the Neo-Archean Kostomuksha greenstone structure of the Fennoscandian Shield. The features of the zonal pillow structure include a narrow range of variations in concentrations of rare-earth elements (REEs), similar REE patterns of dacite and andesite from the pillow core and komatiite and komatiitic basalt from the outer part, and higher REE contents of andesite relative to dacite. These features of REE distribution indicate liquation differentiation of basic melts. According to the Sm–Nd isotopic systematics of rocks of the komatiite matrix and dacite, their isochron age is 2874 ± 35 Ma (εNd = +1.5). Our data indicate an older (than was previously considered) age of the Kontok Group of the Kostomuksha greenschist structure.
{"title":"Liquation Differentiation of Komatiites: Features of Isotopic–Geochemical Composition of Rocks, Age, and Petrological–Geodynamic Implications (Using the Example of the Kostomuksha Greenstone Structure, Fennoscandian Shield)","authors":"A. B. Vrevsky","doi":"10.1134/s107570152308010x","DOIUrl":"https://doi.org/10.1134/s107570152308010x","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>This paper presents the data on the structure and composition of a concentric-zonal komatiite pillow from the Ruvinvaar Formation of the Neo-Archean Kostomuksha greenstone structure of the Fennoscandian Shield. The features of the zonal pillow structure include a narrow range of variations in concentrations of rare-earth elements (REEs), similar REE patterns of dacite and andesite from the pillow core and komatiite and komatiitic basalt from the outer part, and higher REE contents of andesite relative to dacite. These features of REE distribution indicate liquation differentiation of basic melts. According to the Sm–Nd isotopic systematics of rocks of the komatiite matrix and dacite, their isochron age is 2874 ± 35 Ma (εNd = +1.5). Our data indicate an older (than was previously considered) age of the Kontok Group of the Kostomuksha greenschist structure.</p>","PeriodicalId":12719,"journal":{"name":"Geology of Ore Deposits","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2024-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139763050","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/s1075701523080093
N. V. Sidorova, N. N. Korotaeva, E. M. Spiridonov, D. A. Khanin
Abstract
New data are reported on composition and morphology of wulfenite—stolzite-range minerals in oxidized ores at the Novoburannoe (Gumbeyskoe) scheelite deposit in the Southern Urals (Russia). Supergene stolzite and W-bearing wulfenite occur as veinletlike complex-zoned aggregates along the cracks in Mo-bearing scheelite at the point of contact with calcite, dolomite, chalcopyrite, and tennantite. The mineral composition varies from Mo-bearing stolzite (Pb0.98Ca0.02)(W0.78Mo0.22)О4 and W-rich wulfenite (Pb0.93Sr0.05Ca0.02)(Mo0.59W0.41)О4 to pure wulfenite. W-bearing wulfenite is predominant in the studied samples. W-free wulfenite forms pseudomorphs after molybdenite inclusions in galena.
摘要 报告了关于俄罗斯南乌拉尔地区Novoburannoe (Gumbeyskoe)白钨矿氧化矿石中的乌芬石-匍匐石系列矿物的成分和形态的新数据。在与方解石、白云石、黄铜矿和天南星石接触的地方，超生钨矿和含W的硫铁矿沿着含钼白钨矿的裂缝以细脉状复合带状聚集体的形式出现。矿物成分从含钼的 stolzite（Pb0.98Ca0.02）(W0.78Mo0.22)О4 和富含 W 的 wulfenite（Pb0.93Sr0.05Ca0.02）(Mo0.59W0.41)О4 到纯粹的 wulfenite 不一而足。在所研究的样品中，含 W 的硫铁矿占主导地位。不含W的硫铁矿在方铅矿中的辉钼矿包裹体后形成假象。
{"title":"Stolzite and Wulfenite in the Oxidation Zone of the Novoburannoe (Gumbeyskoe) Deposit (Southern Urals)","authors":"N. V. Sidorova, N. N. Korotaeva, E. M. Spiridonov, D. A. Khanin","doi":"10.1134/s1075701523080093","DOIUrl":"https://doi.org/10.1134/s1075701523080093","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>New data are reported on composition and morphology of wulfenite—stolzite-range minerals in oxidized ores at the Novoburannoe (Gumbeyskoe) scheelite deposit in the Southern Urals (Russia). Supergene stolzite and W-bearing wulfenite occur as veinletlike complex-zoned aggregates along the cracks in Mo-bearing scheelite at the point of contact with calcite, dolomite, chalcopyrite, and tennantite. The mineral composition varies from Mo-bearing stolzite (Pb<sub>0.98</sub>Ca<sub>0.02</sub>)(W<sub>0.78</sub>Mo<sub>0.22</sub>)О<sub>4</sub> and W-rich wulfenite (Pb<sub>0.93</sub>Sr<sub>0.05</sub>Ca<sub>0.02</sub>)(Mo<sub>0.59</sub>W<sub>0.41</sub>)О<sub>4</sub> to pure wulfenite. W-bearing wulfenite is predominant in the studied samples. W-free wulfenite forms pseudomorphs after molybdenite inclusions in galena.</p>","PeriodicalId":12719,"journal":{"name":"Geology of Ore Deposits","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2024-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140881633","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/s1075701523080111
E. S. Zhitova, A. A. Nuzhdaev, A. V. Sergeeva, V. V. Shilovskikh
Abstract
This work considers the occurrence of Hg in a clay strata and pore fluids and conditions of Hg incorporation in sulfides and clay minerals abundant in thermal fields of the Koshelev, Kambalny, and Pauzhetka hydrothermal systems. It is shown that, under physicochemical conditions typical of the studied thermal fields, Hg is mostly incorporated in sulfides (pyrite, marcasite, cinnabar) and clay minerals (kaolinite and montmorillonite) as a result of sorption. Under the conditions of a thermal field, cinnabar is the most stable Hg form, because Fe sulfides are unstable during oxidation. The optimal pH value for Hg sorption by clay minerals (in the absence of chlorides and sulfites) is 3.15. In the presence of Hg-bonding chlorides, sulfites, and other anions, the optimal Hg sorption on layered silicates starts from a pH value of >5. The Hg sorption by clay minerals strongly depends on the local highly dynamic geochemical conditions.
{"title":"Hg Mineral Forms in Argillisites of the South Kamchatka Thermal Fields, Russia","authors":"E. S. Zhitova, A. A. Nuzhdaev, A. V. Sergeeva, V. V. Shilovskikh","doi":"10.1134/s1075701523080111","DOIUrl":"https://doi.org/10.1134/s1075701523080111","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>This work considers the occurrence of Hg in a clay strata and pore fluids and conditions of Hg incorporation in sulfides and clay minerals abundant in thermal fields of the Koshelev, Kambalny, and Pauzhetka hydrothermal systems. It is shown that, under physicochemical conditions typical of the studied thermal fields, Hg is mostly incorporated in sulfides (pyrite, marcasite, cinnabar) and clay minerals (kaolinite and montmorillonite) as a result of sorption. Under the conditions of a thermal field, cinnabar is the most stable Hg form, because Fe sulfides are unstable during oxidation. The optimal pH value for Hg sorption by clay minerals (in the absence of chlorides and sulfites) is 3.15. In the presence of Hg-bonding chlorides, sulfites, and other anions, the optimal Hg sorption on layered silicates starts from a pH value of >5. The Hg sorption by clay minerals strongly depends on the local highly dynamic geochemical conditions.</p>","PeriodicalId":12719,"journal":{"name":"Geology of Ore Deposits","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2024-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139763051","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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