Abstract
The results of the study of rare-metal (Bi, Te, Se. Be, In) mineralization of skarn deposits (Sn, Zn) in the Pitkäranta Mining District, genetically related to the Salmi anorthosite-rapakivi granite batholiths of Early Riphean age are reported. Minerals and their chemical composition were identified on the base of optical microscopy as well as electron microanalysis. The diversity of rare-metal ore mineralization (native metals, oxides, and hydroxides, carbonates, tellurides, selenides, sulfides, sulphosalts, borates, and silicates) in Pitkäranta Mining District ores is indicative of considerable variations in the physicochemical conditions of their formation controlled by the discrete-pulse-like supply of fluids. Bismuth, wittichenite, and matildite are the most common rare-metal minerals. Sulfosalts of the bismuthinite-aikinite series are represented only by its end-members. The absence of solid solution exsolution structures in sulfobismuthides suggests that they crystallized from hydrothermal solutions at low temperatures. Be (>10 minerals) and In (roquesite) minerals occur mainly in aposkarn greisens. Roquesite in Pitkäranta Mining District ores formed upon greisen alteration of skarns with In released upon the alteration of In-bearing solid sphalerite (Cu1+ In3+) ↔ (Zn2+, Fe2+) and chalcopyrite In3+ ↔ Fe3+ and 2Fe3+ ↔ (Fe2+, Zn2+) Sn4+ solutions. Sphalerite with an average In concentration of 2001 ppm, is a major In-bearing mineral in the ores.
Highlights
The Pitkäranta Mining District (PMD) is located on the northeastern shore of LakeLadoga, NW Russia (Figure 1)
Rare-metal (In, Bi, Te, Se, Be) mineralization in the PMD is consistent in species diversity with that of skarn deposits, in which the cessation of ore formation was paralleled by the formation of low-temperature metasomatic rocks with the well-defined ore-geochemical association Au-Bi-Pb-Sb-Ag-Te-As [54,55,56,57] and deposits with aposkarn metasomatic rocks such as fluorite-enriched greisens with Be [58]
Rare-metal mineralization in the ores of skarn deposits in the PMD is mainly represented by In, Bi, Be, Te, and Se. It is consistent in the diversity of mineral varieties to that of skarn deposits, in which the cessation of ore formation was paralleled by the formation of low-temperature metasomatic rocks with the well-defined ore-geochemical association Au-Bi-Ag-Te-As, and deposits with aposkarn metasomatic rocks such as fluorite-enriched greisens with Be minerals and roquesite
Summary
The Pitkäranta Mining District (PMD) is located on the northeastern shore of Lake. Ladoga, NW Russia (Figure 1). The ore-forming potential of rapakivi granites on a global scale was firstly evaluated by the end of the 20th century, with several economic deposits of various types considered to be genetically associated with them [5], including unusually large tin deposits in Brazil [19,20]. Revealing indium (roquesite) mineralization in greisens from Vyborg Batholith rapakivi granites [21,22], in the skarns of the PMD [12,23], and economic concentrations of In, Bi, Be and Cd and other rare metals in PMD ores [13], provided another argument in favor of the metallogenic potential of rapakivi granites. The features of the distribution of roquesite in skarn ores are shown
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
