Unveiling the polyphasic evolution of the Neoarchean IOCG Salobo deposit, Carajás Mineral Province, Brazil: Insights from magnetite trace elements and sulfur isotopes

The Salobo iron oxide copper-gold (IOCG) deposit host an important Cu-mineralization of the Carajás Mineral Province. ore is characterized by association (bornite-chalcocite-digenite) hosted magnetite and biotite-garnet schists. These rocks record distinct stages superimposed hydrothermal alteration dynamic metamorphism. Three different occurrences constitute bodies: a pristine to inclusion-poor Mgt I; inclusion-rich magnetite-bearing breccia II, granoblastic-foliated III. In general, types present similar trace element composition with some variations in Si, Al, Mg K indicating that share same magmatic-hydrothermal origin post-formation processes (dissolution/reprecipitation) recorded addition, sulfur isotope signatures for chalcopyrite (1.3–3.35‰), pyrrhotite (0.88–1.98‰), pyrite (1.7–5.04‰) associated I are consistent source at without/or minimal external contributions. Our data indicate ore-forming fluids could have undergone disproportionation during sulfide formation due precipitation, which results classic IOCG mineral + described first time this contribution. Therefore, main mineralization event be coeval deposits Province related Neoarchean magmatism ca. 2.7 Ga. Subsequent deformation low-grade metamorphism reactivation Cinzento Shear Zone (ca. 2.5 Ga) A-type granite emplacement probably Paleoproterozoic age resulted remobilization-recrystallization Cu-sulfides.