Long-lived Neoproterozoic high-K magmatism in the Pernambuco–Alagoas Domain, Borborema Province, northeast Brazil

Abstract

The Pernambuco-Alagoas (PE-AL) Domain contains major granitic batholiths typified by a wide range of T DM model ages (Archaean to Neoproterozoic), reflecting the important role of quartzofeldspathic plutons attending the Brasiliano (Pan-African) Orogeny. U/Pb zircon data for eight syn-to post-collision to syn-transcurrent granitic intrusions of the PE-AL Domain allow the studied plutons to be divided into two groups: (1) granitoids with crystallization ages older than 600 Ma (Água Branca, Serra do Catú, Serra da Caiçara, and Mata Grande plutons) and (2) granitoids with ages of ca. 590 Ma (Correntes, Águas Belas, Viçosa, and Cachoeirinha plutons). The intrusions of group 1, except for the Mata Grande Pluton, all show Nd T DM model ages ranging from 1.5 to 1.2 Ga, whereas the granitoids from group 2 and the Mata Grande Pluton have Nd T DM model ages ranging from 2.2 to 1.7 Ga. The studied granitoids are in part high-K, calc-alkaline, shoshonitic, and in part transitional high-K calc-alkaline to alkaline in terms of their bulk chemistry. Volcanic arc signatures associated with the Palaeoproterozoic T DM model ages are interpreted as inherited from the source rocks. The oldest ages and higher Nd T DM model ages recorded in the granitoids intruded in the southwestern part of the PE-AL Domain suggest that these intrusions are associated with slab-tearing during convergence between the PE-AL and Sergipano domains. The investigated plutons are coeval with high-K granitoids intruded within the Transversal Zone Domain of Borborema Province and calc-alkaline granitoids of the Sergipano Domain. This suggests that these geologic realms belonged to the same crustal block during the Brasiliano Orogeny. However, such large volumes of high-K granitoids with crystallization ages older than 600 Ma are not recorded in the Sergipano and Transversal Zone domains, suggesting differences in the crustal evolution of these three areas.

From extension to shortening: Dating the onset of the Brasiliano Orogeny in eastern Borborema Province (NE Brazil)

“…The age of 615 Ma falls within the age range of 632e606 Ma estimated for the peak of metamorphism contemporaneous with thrusting in the Central and Pernambuco-Alagoas domains (Neves et al, 2006b. It is also similar within errors to the ages of intrusion of syn-orogenic calc-alkaline granitoids in the Pernambuco-Alagoas and Central domains (624e616 Ma; Guimarães et al, 2011;Neves et al, 2012;Da Silva Filho et al, 2013) and in the Sergipano Belt (628e625 Ma;Long et al, 2005;Bueno et al, 2009). It seems therefore that in the whole eastern portion of the Borborema Province a change from (Boynton, 1984).…”

Geochemistry and geochronology of the ~620 Ma gold-associated Batouri granitoids, Cameroon

“…Granitoids of the 640-620 Ma age range are significantly present in the Transverse, Pernambuco-Alagoas, and Sergipano domains of the Borborema Province, which is the Brazilian equivalent for the CAFB (Galindo et al 1995;Van Schmus et al 2008Guimarães et al 2011. In a recent study of the Buique-Paulo Alfonso and Áqua Belas-Canindé batholiths outcropping in the Pernambuco-Alagoas Domain, Silva Filho et al (2013) reported the occurrence of granites that range in age from 612 ± 7 to 624 ± 5 Ma. Similar ages have been reported for the Sitios Novos and Coronel João Sá granitoid Plutons (Silva Filho et al 1997), as well as the granitic rocks occurring along the Belo Monte Jeremoabo and Macururé Shear Zones (Araújo et al 2004) within the Sergipano Domain.…”

Petrologia dos Stocks Santa Maria, Monte Pedral, Bom Jardim, Boa Esperança e Niterói, Suíte Intrusiva Serra do Catu, Estado de Sergipe, NE Brasil

“…Os dados geocronológicos disponíveis para o magmatismo shoshonítico no Sul da Província Borborema (e.g., Guimarães et al, 2004;Brito et al, 2009;Silva Filho et al, 2013Ferreira et al, 2015;Lima, 2016;Lisboa et al, 2019) sugerem que a colocação desses corpos está relacionada ao evento de colisão e que eles são intrusivos em dois momentos distintos da evolução do arco vulcânico (Silva Filho et al, 2013;Lisboa et al, 2019).…”