Prolonged Paleoproterozoic magmatic participation in the Neoproterozoic Dom Feliciano belt, Santa Catarina, Brazil, based on zircon U–Pb SHRIMP geochronology

The dating of 47 spots in 42 zircon crystals from three rock samples using sensitive high-resolution ion microprobe (SHRIMP II) leads to a much better understanding of Paleoproterozoic magmatic participation in the construction of the Dom Feliciano Belt from the Precambrian shield of Santa Catarina, Brazil. One Archean age from the presumed basement of the Camboriú region is preserved as an inherited core in a zircon crystal, but 3.2–2.6 Ga model Nd TDM ages are present in several granitic rocks. The gneisses and migmatites of the Camboriú Complex were generated in a tectonic scenario, possibly comparable to an active continental margin setting at approximately 2.25–2.00 Ga during the Trans-Amazonian cycle. The precursor volcano-sedimentary basin of the Brusque Complex formed in a rift basin younger than 2.02 Ga. The Itapema Granite crystallized at approximately 2.02 Ga, controlled by flat-lying structures during a major event of the Trans-Amazonian cycle, and was again deformed at 598±6 Ma. A long period of stability occurred in the region between 2.00 and 0.63 Ga, followed by thrusting of the Trans-Amazonian units during an early event of the Brasiliano cycle. Widespread deformation and magmatism took place along transcurrent shear zones that compose the southern Brazilian shear belt, peaking at approximately 0.63–0.59 Ga, which eventually led to the construction of the Florianópolis Batholith. These previously unknown ages place significant constraints on the evolution of the southern Brazilian shield, with implications for the history of amalgamation and dispersal of the Precambrian supercontinents.