Summary:
The Celesta Copper Project comprises multiple high-grade IOCG breccias.
The Maravaia deposit encloses four main copper-gold prospects, named respectively West, Osmar (now the Celesta), Galpão and East targets.
The Osmar Target is characterized by the presence of metamafic rocks, metadiorite, iron formation with strong hydrothermal alteration, amphibole-rich breccia zones and quartz breccias, altered amphibole-gneiss, intrusive magnetic gabbro-diorite, intrusive rocks of anorthositic composition, consolidated lateritic cover, lateritic covers, ferruginous colluvium (residual and transported), alluvial cover and old mining dump.
Two main associations of hydrothermal alteration were identified: a distal, pervasive alteration, characterized by the presence of scapolite and amphibole (in part chloritized), affected by deformation and shear (NNW and NW); the second association, superimposed on the first, is marked by breccia zones (NNW-SSE trending) with amphibole-albite-magnetite and that includes the copper occurrences on surface. Brecciation increases eastwards, with more frequent presence of veins of hydrothermal magnetite. It is noteworthy the correlation of these magnetite veins with second order magnetic anomalies. The two associations are limited to the east by a N20ºE oriented structure. The north-northeast limit is marked by thick iron formation unit, with enrichment in iron (iron deposit of Mineração Vertical Ltda.).
Diamond drillholes intercepted mineralized hydrothermal breccias containing amphibolemagnetite carbonate-chalcopyrite-pyrite and quartz-chlorite-clay-amphibole-chalcopyrite-pyrite, with higher content of sulfides. The frequent presence of kaolinite in the drill cores was reported, associated with the mineralized intercepts. A thick profile of supergene enrichment developed in the area, with the presence of malachite, cuprite, native copper, chalcocite and jasperoid.
The copper-gold Maravaia mineralization is hosted in veins associated with hydrothermal breccias, contained in NS to NE/SW orientated tension gashes. These structures are associated with a NW/SE shear zone that cuts amphibolite, diorite and gabbro and, located between the regional Cinzento and Carajás shear belts.
The surface mineralization (up to ± 70 m deep) is composed of malachite, azurite, chrysocolla, cuprite and native copper, plus hydroxides of copper and iron.
At depths greater than 70 m, chalcocite, chalcopyrite and native copper predominate, with subordinate bornite, pyrite and magnetite.
Zones extremely rich in copper occur locally with massive horizons of native copper associated with chalcocite and cuprite at depths greater than 120 m.