The Troia–Pedra Branca mafic–ultramafic complex, Borborema Province, Brazil: Record of 2.04 Ga post–collisional Alaskan–type magmatism and PGE mineralization

Gamma-ray spectrometry, magnetic and gravity signatures of Archean nuclei of the Borborema Province, Northeastern Brazil

“…The oldest ages for rocks in the Borborema Province were identified in eight small scattered nuclei (e.g., Dantas et al 2004Ganade et al 2017;Pitarello et al 2019;Lira Santos et al 2017;Ferreira et al 2020) (Figure 1): 1 -São José do Campestre, 2 -Campo Grande, 3 -Tróia-Pedra Branca, 4 -Granjeiro I, 5 -Granjeiro II, 6 -Entremontes, 7 -Alto Moxotó and 8 -Itabaiana-Simão Dias. These Archean units of the Borborema Province generally occur in continuity with Paleoproterozoic complexes (Dantas et al 2004Souza et al 2016;Lira Santos et al 2017;Ganade et al 2017;Vale et al 2023;Costa et al 2019Costa et al , 2021Ferreira et al 2020;Brito Neves et al 2020). This association between Archean and Paleoproterozoic rocks suggests accretionary collision processes (e.g., Souza et al 2016;Neves 2015;Lira Santos et al 2015Ferreira et al 2020;Amaral et al 2023) that resulted in the formation of the basement of the Neoproterozoic sedimentary basins, which was later deformed and metamorphosed in the Brasiliano/Pan-African Orogeny (e.g., Van Schmus et al 2003;Arthaud et al 2008;Oliveira et al 2010;Brito Neves et al 2015, 2018Caxito et al 2016).…”

“…For example, contrary to the metallogenic expectations for Archean rocks, so far no important mineral resources have been identified in these domains, exception for small Fe deposits in the Granjeiro II (Pitarello et al 2019) and São José do Campestre (Dantas and Roig 2013;Roig and Dantas 2013) nuclei. Despite the proximity to Archean rocks, the small deposits of Au and Cr in de Troia-Pedra Branca nucleus are hosted in Paleoproterozoic rocks (Costa et al 2019;Costa et al 2021).…”