Nd and Sr-Isotopic and U-Pb Geochronologic Constraints for Evolution of the Shoshonitic Brasiliano Bom Jardim and Toritama Complexes: Evidence for a Transamazonian Enriched Mantle Under Borborema Tectonic Province, Brazil

Emplacement and deformation of the Cachoeirinha pluton (Borborema province, NE Brazil) inferred through petrostructural studies: Constraints on regional strain fields

“…1c). A 3Nd (600 Ma) value of K11.2 obtained for the Cachoeirinha pluton is within the range of 3Nd values reported for the Bom Jardim complex and the Toritama pluton (Guimarães and Da Silva Filho, 1998), which suggests that these three syenitic bodies may have a similar source. …”

“…10 K11 a K1 (Steiger and Jaeger, 1977) and excluding the country rock samples. This age is similar, within error, to (1) the zircon U-Pb age (592G7 Ma) of the Bom Jardim complex (Guimarães and Da Silva Filho, 1998), a syenitic pluton in the central domain of the Borborema province mainly composed of a coarse-grained syenite petrographically similar to the main facies of the Cachoeirinha pluton; (2) the whole-rock Rb-Sr age of 585G38 Ma of the Toritama pluton (Guimarães and Da Silva Filho, 1998), another syenite pluton that crops out northeast of the Caruaru-Arcoverde batholith; and (3) the zircon U-Pb (588G12 Ma; Guimarães et al, 2004) and Pb-Pb (591G5 and 587G5 Ma; Neves et al, 2004) ages of the CaruaruArcoverde batholith (Fig. 1c).…”

High K Calc-Alkaline Granitoids of Ca. 1 Ga. TDM Along the Limit Peal Massif/Sergipano Fold Belt, Ne Brazil and Their Geotectonic Significance.

“…The present lack of clear evidence of a paleo suture between the PE-AL Massif and the Sergipano Fold Belt, as gravimetric anomalies and ophiolitic complexes, does not rule out a priori this hypothesis, as the identified PE-AL Massif batholiths could be the remnants of an arc. On the other hand, as other authors defend (Van Schmus et al 1995;Neves et al 2000), the absence of Brasiliano -age suture zones in the inner part of BP, and the voluminous predominance of I -type granitoids far away from the boundary zones with the adjoining cratons (Silva Filho et al 1997;Neves and Mariano 1997;Ferreira et al 1998;Guimarães and Silva Filho 1998) suggests the magmatism is not directly subduction-related. As the southern part of the PE-AL Massif is close to the NE margin of the São Francisco Craton the generation of the study rocks by subduction process should be examined carefully.…”

“…DISCUSSION AND CONCLUSIONS Recent petrologic works over the main metaluminous high -K to shoshonitic granitic suites from the Borborema Province (Silva Filho et al 1997;Guimarães and Silva Filho 1998, Neves et al 1998, Mariano et al 1999) point unanimously to the existence of an upper mantle metasomatized during the Paleoproterozoic, respectively in the Northern, Central and Southern Domains. This paper shows that the high-K calc alkaline granites in the Southern Domain of the Borborema Province could not be generated from a Paleoproterozoic lithospheric mantle.…”

Geological and isotopic characteristics of granites from the Western Pernambuco-Alagoas Domain: implications for the crustal evolution of the Neoproterozoic Borborema Province

“…All schemes of classification of the Neoproterozoic granitic magmatism in NE Brazil (e.g. Almeida et al 1977;Sial 1986;Guimarães et al 1998) describe the increasing alkalinity of the magmatism with time, starting with normal calc-alkaline rocks and ending with alkali-rich granites and shoshonites. The most recent classification is from Van Schmus et al (2011), who recognized five stages: Phase I, consisting of pre-collisional granitoids (650 -610 Ma); Phase II, syn-collisional granites (610 -595 Ma); Phase III, post-collisional, pre-transcurrent granites (595 -576 Ma); Phase IV, syn-transcurrent intrusions (576 -560 Ma); and Phase V, post-tectonic granites (550 -530 Ma).…”