Paleoproterozoic Mafic-Ultramafic Magmatism in the Northern Borborema Province, Northeast Brazil: Tectonic Setting and Potential for Deposits

Arc accretion and crustal reworking from late Archean to Neoproterozoic in Northeast Brazil

“…4A-D). Our results support that 2.9 Ga and 2.7-2.6 Ga Archean crustal reworking and minor 2.2 Ga Paleoproterozoic juvenile mantle were the primary sources for the continental growth through accretionary mechanisms 5,15,16,19,45,46 . The first rim around the Archean core seems to engulf the core migmatites www.nature.com/scientificreports www.nature.com/scientificreports/ in a circular shape (Fig.…”

“…600 Ma zircon grains that show varying degrees of rounding or absorbed borders (Fig. 2C), similar to features described in zircon grains from ultramafic rocks in high-grade metamorphic terrains 44,45 . The supracrustal rocks, such as garnet-biotite gneiss (AT-23 sample), bear 2.7-2.6 Ga zircon cores, suggesting that Neoarchean tonalite and tholeiitic rocks were the main provenance (Fig.…”

“…3G). Nevertheless, it is indisputable that the protolith sources are dominantly Neoarchean, as suggested for the Lajes Block 45 .…”

Late Ediacaran lateral-escape tectonics as recorded by the Patos shear zone (Borborema Province, NE Brazil)

“…This basement also contains minor Orosirian metavolcano-sedimentary sequences and plutons (Sá et al 1995, Hollanda et al 2011, Sá et al 2014, as well as local Siderian rocks situated next to the Transbrasiliano Lineament (Santos et al 2009; Fig. 1B) and in the Seridó belt (Hollanda et al 2011, Ferreira et al 2019; Fig. 2).…”

“…2). Siderian rocks have been recorded to the North and South of the Seridó belt (Ferreira et al 2019, Hollanda et al 2011, between the Coremas Dam and Granjeiro town (this study; Freimann 2014) and to the Southwest next to the Pernambuco shear zone (Pitarello et al 2019). Archean rocks occur in the basement of the Seridó belt (Dantas et al 2013, Ferreira et al 2020, on well-logs from samples to the West of the Seridó metapelites (Cavalcante et al 2018), in the Lavras da Mangabeira duplex (this study, Hollanda et al 2015, Silva et al 1997, and in the Ipueirinha belt (Pitarello et al 2019).…”