Oxides of the Pyrochlore Supergroup from a Nonsulfide Endogenic Assemblage of Pb–Zn–Sb–As Minerals in the Pelagonian Massif, Macedonia

Resumo

The specific features of the chemical composition, isomorphism, and zoning have been studied for pyrochlore supergroup minerals (PSM) from metasomatic rocks of ore occurrence no. 9 (Nezilovo, Pelagonian Massif, Republic of Macedonia). Ore occurrence no. 9 has an unusual nonsulfide association of chalcophile elements: Zn, As, Sb and Pb. Pyrochlore supergroup minerals crystallized at all stages of metasomatism. Zoning of pyrochlore supergroup minerals and their relationships with associated minerals (Zn-bearing silicates, tilasite, barite, carbonates, various accessory Pb-, Sb- and Zn-oxides, etc.) suggest a complex geochemical evolution of ore occurrence no. 9. The possible mechanism for the formation of nonsulfide parageneses of chalcophile elements is discussed.