The Borborema Province represents a collage of tectonic blocks amalgamated to Gondwana during the Neoproterozoic. The Pernambuco -Alagoas Domain constitutes the southern part of the Borborema Province, which comprises three subdomains (Garanhuns, Água Branca, and Palmares) separated by shear zones. Investigation of an area across the boundary between the Palmares and Garanhuns subdomains revealed contrasting aerogeophysical fabrics and geological setting with igneous and metasedimentary rocks of Paleoproterozoic and Neoproterozoic ages. The Palmares shear zone divides the studied area into 2 subdomains: 1) Palmares to the south and 2) Garanhuns to the north. Nd isotopic studies show contrasting crustal signatures between the Garanhuns and Palmares subdomains, with Nd T_DM model ages ranging from 1.8 to 2.70 Ga for the Garanhuns subdomain and from 0.90 to 1.60 for the Palmares subdomain. The Palmares shear zone constitutes a major crustal boundary, and in pre drift reconstructions may have continuity in Africa as the Tcholliré-Banyo shear zone. The data suggest that the area evolved during two distinct orogenies: 1) Rhyacian-Orosirian (2095 Ma to 1987 Ma), which involved mainly the reworking of Archaean crust, and 2) Cryogenian-Ediacaran (630 Ma to 585 Ma), the so-called Brasiliano-Pan African Orogeny. Our findings, i.e. contrasting isotopic subdomains separated by an important shear zone, suggest that Brasiliano Orogeny, at least in the Pernambuco Alagoas domain, had an accretionary nature.

Ediacaran–Cambrian magmatism in the Central Subprovince (Borborema Province, NE Brazil) generated abundant A-type granites. This study reviews published whole-rock and mineral chemistry data from thirteen Ediacaran–Cambrian A-type intrusions and a related dike swarm. It also presents new mineral chemistry and whole-rock data for one of these intrusions, along with zircon trace element data for five of the intrusions. Geochronological data from the literature indicate the formation of these A-type intrusions during a 55 Myr interval (580–525 Ma), succeeding the post-collisional high-K magmatism in the region at c. 590–580 Ma. The studied plutons intruded Paleoproterozoic basement gneisses or Neoproterozoic supracrustal rocks. They are ferroan, metaluminous to peraluminous and mostly alkalic–calcic. The crystallization parameters show pressure estimates mainly from 4 to 7 kbar, corresponding to crustal depths of 12 to 21 km, and temperatures ranging from 1160 to 650 °C in granitoids containing mafic enclaves, and from 990 to 680 °C in those lacking or containing only rare mafic enclaves. The presence of Fe-rich mineral assemblages including ilmenite indicates that the A-type granites crystallized under low ƒO₂ conditions. Zircon trace element analyses suggest post-magmatic hydrothermal processes, interpreted to be associated with shear zone reactivation. Whole-rock geochemical characteristics, the chemistry of the Fe-rich mafic mineral assemblages, and zircon trace elements in the studied granitoids share important similarities with A₂-type granites worldwide.