The Serra das Araras Batholith: An example of Ediacaran syntectonic peraluminous granitic magmatism in the southwestern Paraíba do Sul Domain

The Serra das Araras Batholith (SAB), located at the southwest portion of the Paraíba do Sul Domain, Central Ribeira Belt, is composed of orthogneisses with peraluminous character. Combined LA-ICP-MS U-Pb and Lu-Hf isotopic analyses have been performed in zircon grains for a representative sample (SA-3H) of SAB. Data point to Rhyacian to Orosirian (ca. 2.1-1.8 Ga) inherited zircon cores with positive ɛHf(t) values and Ediacaran U-Pb crystallization age (595 ± 8 Ma). A leucogranite dyke (SA-3D), 15-25 cm thick, which crosscuts SAB and a biotite-hornblende quartz diorite enclave (SA-06) have been analyzed. Crystallization ages for the three samples (ca. 600-590 Ma) and ɛHf(t) values, ranging from −5.6 to −29.4 for Neoproterozoic zircon grains, indicate an Ediacaran crustal magmatism involving mid to lower crust anatexis and the reworking of Paleoproterozoic juvenile and crustal rocks.