Changing provenance of Late Jurassic to Early Cretaceous rift-related sedimentary rocks of the South Atlantic Margin: LA-MC-ICPMS U–Pb and Lu–Hf isotopic study of detrital zircons from the Camamu Basin, Eastern Brazil

The Camamu basin is related to the breakup of Gondwana and belongs to the group of sedimentary basins that are part of the eastern Brazilian passive margin. We have determined the provenance of the precursor sediments by investigating the petrography of fluvial and eolian units from the early-rift Brotas Group and syn-rift Almada Group, coupled to in situ laser ablation MC-ICPMS U–Pb and Lu–Hf isotopic analyses of the detrital zircon grains. Detrital zircon grains from the Sergi Formation, Brotas Group, have a main population of U–Pb ages of 480–600 Ma with smaller populations of ages of 900–1000 Ma, 1900–2100 Ma, 2500–2800 Ma and 3000–3200 Ma. The Almada Group zircon grains are characterized by a distribution of ages predominantly in the Paleoproterozoic and Archean. The Hf TDM model ages of the Brotas and Almada Group zircon grains range from ca. 1.1 to 4.0 Ga, and the εHf(t) values vary from − 31.4 to + 9.6, providing evidence that some detrital zircon grains in the Camamu Basin we