Hibbingite and Its Manganoan Variety from Metamorphosed Pentlandite–Putoranite Ores at Deep Levels of the Oktyabrskoe Deposit, Norilsk Ore Field.

Autor: Spiridonov, E. M., Belyakov, S. N., Ivanova, Yu. A., Egorov, K. V., Korotaeva, N. N., Naumov, D. I., Yapaskurt, O. V.
Zdroj: Geology of Ore Deposits; Dec2022, Vol. 64 Issue 7, p495-502, 8p
Abstrakt: Hibbingite, siderite, and their manganoan varieties replacing magnetite and associated sulfides are widespread in tectonized and metamorphosed pentlandite–putoranite ores with magnetite at the deep level of the Oktyabrskoe deposit in the Norlisk ore field, Krasnoyarsk krai. Hibbingite aggregates are formed by intergrown lamellar crystals. Hibbingite, (OH)3Cl, contains 2–38 mol % kempite endmember, (OH)3Cl. Hibbingite with 7–13% kempite molecule is common. Hibbingite replacing magnetite and putoranite is enriched in Cu, up to 2.6 wt %, which corresponds to the 4 mol % atacamite endmember, (OH)3Cl. Hibbingite replacing magnetite and pentlandite is enriched in Ni, up to 1.5 wt %. In zoned siderite crystals, the siderite core is depleted in minor elements, whereas the rim is enriched in Mn (up to 23 mol % rhodochrosite molecule) and Cu (up to 4.5 wt % CuO). Native silver and sphalerite enriched in Cd are associated with hibbingite and siderite. These are low-temperature metamorphic-hydrothermal assemblages formed under zeolite facies conditions. Replacement of magnetite by hibbingite and siderite is a reductive process that appears to have occurred in an acidic–CO2 environment possibly involving hydrocarbons or hydrogen. The likely reaction is Fe2+ O4 + HCl + СО2 + H2 → (OH)3Cl + Fe2+[CO3]. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index
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