Hibbingite and its manganoan variety from metamorphosed pentlandite-putoranite ores at deep levels of the Oktyabrskoye deposit, Norilsk ore field

Spiridonov E. M., Belyakov S. N., Ivanova Yu. A., Egorov K. V., Korotaeva N. N., Naumov D. I., Yapaskurt O. V.

Zapiski RMO (Proceedings of the Russian Mineralogical Society). 2020. V. 149. N 6. P. 32-42

https://doi.org/10.31857/S0869605520060143

Language: Russian

Abstract

Hibbingite and its manganoan variety, (Fe²⁺,Mn²⁺)₂(OH)₃Cl, and siderite, including its manganoan variety, (Fe²⁺,Mn²⁺)[CO₃], replacing magnetite and associated sulphides, occur in tectonized and metamorphosed pentlandite-putoranite ores at deep levels of the Oktyabrskoye deposit belonging to the Norilsk ore field (Siberia). Hibbingite aggregates are formed by lamellar crystals. Hibbingite contains 2–38 mol. % of the kempite component. Hibbingite with 7–13% of the kempite component is common. Hibbingite replacing magnetite and putoranite, is enriched in copper: up to 2.6 wt % Cu that corresponds to 4 mol. % of the atacamite component. Hibbingite replacing magnetite and pentlandite contains up to 1.5 wt % Ni. In zonal siderite crystals cores are composed of low-impurity siderite, whereas rim is enriched in Mn (up to 23 mol. % of the rhodochrosite end member) and Cu (up to 4.5 wt % CuO). Pure native silver and cadmium-enriched sphalerite are associated with hibbingite and siderite. These are low-temperature metamorphogenic-hydrothermal mineralizations developed under the conditions of zeolite facies. The replacing of magnetite for hibbingite and siderite is a reduction process that apparently took place under acidic–carbon dioxide conditions with the participation of hydrocarbons or hydrogen. The probable reaction is: Fe²⁺Fe³⁺₂O₄+ HCl + СО₂ + H₂ → Fe²⁺₂(OH)₃Cl+ Fe²⁺[CO₃].

Keywords: metamorphogenic-hydrothermal hibbingite, manganoan hibbingite, Norilsk ore field