Work

Linking Neoarchean hydrothermal nickel and IOCG mineralization at the Jaguar Norte Cu–Ni deposit, Carajás Mineral Province (Brazil): constraints from multi-mineral petrological, isotopic, and geochronological data

Year: 2026

Type: article

Abstract: Hydrothermal nickel deposits are uncommon, and their origin remains poorly constrained. In the Carajás Mineral Province, spatial association between Ni sulfides and iron oxide-copper–gold (IOCG) deposits suggests that both are genetically linked. This study investigates the Jaguar Norte Cu–Ni deposit using a multi-mineral isotopic approach to constrain timing, sources, and processes linking hydrothermal Ni and IOCG mineralization. The deposit comprises two orebodies near the intersection of the E-W Canaã Shear Zone and the NE-trending McCandless Fault. The NE orebody is hosted by 3.0–2.9 Ga granitoids affected by HT Na-Ca, HT Ca-Fe, HT K-Fe, and LT Mg-Fe alteration facies hosting chalcopyrite (±pyrite-pentlandite). The SW orebody hosts Ni sulfides (Ni-pyrrhotite, pentlandite, and millerite) within ultramafic and felsic porphyritic rocks affected by HT Na, HT Na-Ca-Fe, HT Ca-Fe-Mg, and HT K-Fe-Mg assemblages. Hydrothermal zircon displays complex textures, U–Th–LREE enrichment, and evidence of fluid-assisted recrystallization. Zircon (2.70–2.60 Ga) and apatite (ca. 2.65 Ga) U-Pb results indicate a Neoarchean hydrothermal event coeval with major IOCG formation in Carajás, whereas biotite Rb-Sr data (ca. 1.93 Ga) record a Paleoproterozoic overprint. Chalcopyrite from the main Cu mineralization and late Cu-bearing veins exhibit contrasting Pb isotope signatures, with lower μ values in the main Cu stage suggesting a more primitive Pb source, supporting a multistage hydrothermal evolution. Structural, mineralogical, and geochronological evidence demonstrates that the Cu- and Ni-bearing orebodies formed within the same Neoarchean hydrothermal system. Their contrasting metal endowment likely reflects distinct hydrothermal pulses and/or progressive evolution of a hydrothermal fluid plume through changing physicochemical conditions, fluid-rock interaction, incorporation of fluids, differences in host-rock composition, and metal availability. These findings provide new evidence for the genetic link between hydrothermal Ni and IOCG mineralization in Carajás and new insights into metal distribution within IOCG-related hydrothermal systems.

Source: Precambrian Research

DOI: 10.1016/j.precamres.2026.108253