Occurrence of Palladium Mineralization at the Deep Horizons of the Kola Superdeep Borehole

• Published in: Doklady earth sciences Vol. 499; no. 2; pp. 623 - 627
• Main Authors: Lobanov, K. V., Gornostaeva, T. A., Kartashov, P. M., Mokhov, A. V., Chicherov, M. V.
• Format: Journal Article
• Language: English
• Published: Moscow Pleiades Publishing 01.08.2021; Springer; Springer Nature B.V
• Subjects: Bismuth; Boreholes; Earth and Environmental Science; Earth Sciences; Electron microscopy; Fault zones; Faults; Gold; Heavy metals; Intermetallic compounds; Mineralization; Mineralogy; Minerals; Noble metals; Palladium; Silver; Sulfides; Tellurides; Kola superdeep borehole; palladium mineralization; analytical electron microscopy; michenerite; merenskyite; EBSD
• ISSN: 1028-334X; 1531-8354
• DOI: 10.1134/S1028334X21080067

Palladium mineralization was registered in the Kola superdeep borehole (SG-3) for the first time in samples from deep horizons (in the fault zone at ~10 km). A proper palladium mineral (merenskyite) with the formula Pd 1.00 (Te 1.21 Bi 0.79 ) 2.00 was detected using the analytical electron microscopy and EBSD methods. The unusually high content of bismuth in the discovered merenskyite crystal most likely indicates the lower temperatures of its formation from a bismuth-rich fluid. This is supported by numerous finds of associated bismuth minerals (native and intermetallic minerals, sulfides, tellurides, and sulfotellurides) as well. A close geochemical association of noble and rare elements was revealed in the composition of the rich and diverse ore mineralization in the samples studied. It can be argued that a new type of mineralization was discovered for the SG-3 rocks: noble metal (Au–Ag–Pd) rare-element (Bi–Te).