New Data on the Formation Conditions of the Dyvok Ore Occurrence (South Yakutia, Russia)

• Published in: IOP Conference Series: Earth and Environmental Science
• Main Authors: Kardashevskaia, Veronika, Anisimova, Galina
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: IOP Publishing 2019
• Subjects: Yakutia
• Online Access: http://dx.doi.org/10.1088/1755-1315/362/1/012081; https://iopscience.iop.org/article/10.1088/1755-1315/362/1/012081/pdf; https://iopscience.iop.org/article/10.1088/1755-1315/362/1/012081

Abstract The article presents new data on the mineralogical and thermobarogeochemical research of Dyvok ore occurrence. The aim of the research is to learn about the mineral-geochemical characteristics of the ore occurrence as well as about the formation of auriferous mineralogical associations at the occurrence. At the moment, Verkhnealgominsk auriferous area consists of several ore occurrences and a deposit. The area is located within famous Stanovaya auriferous area, South Yakutia. Dyvok ore occurrence is subjected to the influence of Tyrkandinski fault. The host rocks are Early-Archaean K-spar-quartz metasomatites, beresited and argillated rocks with sulphide-quartz veins and mineralised zones of beresited rocks with sulphide and quartz-sulphide mineralisation. Now, there are 3 productive ore zones at the ore occurrence. We found mineral associations that contain native gold and described the variety of its forms, seizes and composition. The mineral associations are 1) gold-arsenopyrite-pyrite-quartz; 2) gold-sphalerite-chalcopyrite; 3) quartz-boulangerite; 4) quartz-telluride. We carried out thermobarogeochemical investigation of fluid inclusions in quartz to learn about the formation conditions of productive mineral associations, the quartz was extracted from gold-arsenopyrite-pyrite-quartz, gold-sphalerite-chalcopyrite and quartz-telluride associations. Microanalyses helped to discover monophase, diphase and three-phase inclusions. Early association had the temperature of 270-335°C. The rated pressure is 0.4 kbar. The inclusions contain carbon dioxide, water, methane and carbonate ion. The solid phase contains dawsonite and native sulphur. The deposition temperature of gold-sphalerite-chalcopyrite association is 186-219°C, and the one of quartz-telluride association is 199-200°C. The pressure of the latter two associations remains unknown due to the lack of coexisting three-phase inclusions. Raman spectroscopy showed the presence of carbon dioxide and methane in early association, as well as of carbon ...