First Lu-Hf, δ18O and trace elements in zircon signatures from the Statherian Espinhaço anorogenic province (Eastern Brazil): geotectonic implications of a silicic large igneous province

The Espinhaco rift system encompasses taphrogenetic events from the Statherian to Tonian in the Sao Francisco-Congo (SFC) paleocontinent. The magmatism is represented mainly by metamorphosed anorogenic granites and rhyolites with subordinate amphibolites. Zircon U–Pb ( LA-ICPMS and SHRIMP) ages from felsic (1748 ± 3 Ma and 1740 ± 8 Ma) and mafic (1725 ± 4 Ma) rock samples, coupled with previous studies suggest that the Espinhaco igneous province erupted from ca. 1.79 Ga to ca. 1.70 Ga. The felsic rocks show characteristics of A-type magmas. The negative eHf(t) data for meta-rhyolite zircons (-12.32 to -17.58), the moderate δ 18 O values (7.02 to 7.98) and the REE patterns suggest crustal melting related to an extensional environment. The mafic rock shows negative values of eHf(t) in zircons (-4.05 to -8.25) and moderate δ 18 O values (5.56 to 7.87). The results disclose a basaltic magmatism in continental intraplate setting whose parental magma could have been derived from the subcontinental lithospheric mantle with contamination of crustal material. These data coupled with coeval Espinhaco magmatism and mafic dyke swarms found to the south of the Espinhaco rift system reinforce the evidence of a long-lived Statherian silicic large igneous province (SLIP) on the SFC paleocontinental block.