Rare-earth elements (REE) and mercury in the historically important Miguel Burnier manganese-ore district, Quadrilátero Ferrífero of Minas Gerais, Brazil

The Miguel Burnier manganese (Mn)-ore deposit, located in the Quadrilátero Ferrífero of Minas Gerais, Brazil, has enrichments in the rare-earth elements (REE). Here, this finding is reported. Three types of REE enrichments have been identified in (1) Cenozoic wad-like diamictite; (2) hydrothermally altered manganiferous mudstone of Cenozoic age; (3) and in lithiophorite-rich veinlets and pockets within Precambrian itabirite. Churchite-(Y) [ Y(PO₄) ·2H₂O] and rhabdophane-(La) [La (PO₄) ·H₂O] are the main REE-bearing minerals. Other metals, in particular mercury (Hg), are also enriched, indicating that metalliferous overprint took place during the Cenozoic in a tectonically stable, cratonic terrane.