Detrital zircon grains analyzed for U-Pb ages for sedimentary provenance studies: Tectonic- driven deposition of the Resende Basin (Eocene-Oligocene) in SE Brazil

Abstract

Abstract The Resende Basin (Eocene-Oligocene) is a continental taphrogenic structure associated with the Continental Rift of Southeast Brazil and includes the Itatiaia and Acácias members. While the sediment provenance of the Itatiaia member is known, such knowledge regarding the Acácias Member is lacking. This work studies U-Pb ages and Lu-Hf data analyzed by laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) in detrital zircons to investigate the sandstone provenance of the Acácias Member. The results suggest that Acácias Member rocks are composed predominantly of Neoproterozoic sources (60%), significant Paleoproterozoic sources (34%) and smaller contributions from Mesoproterozoic (4%) and Archean (2%) sources. The orthogneisses of the Juiz de Fora and Quirino complexes and the metasedimentary rocks of the Andrelandia Complex and Paraíba do Sul were probably the source rocks of Archean and Paleoproterozoic materials. The metasedimentary Embú Complex may be the source of Mesoproterozoic sediments, and the granitoid bodies located south of the Resende Basin (namely,the Rio Turvo granitoid) were important Neoproterozoic sources. No Late Cretaceous ages were found in the 301 analyzed zircons, suggesting that the extensional process that originated in the basin occurred before the Itatiaia alkaline intrusions. In addition, other causes for the lack of zircon grains with the age of alkaline intrusive rocks (Morro Redondo ≈72-70 Ma; Itatiaia ≈70 Ma) may have been related to the basin location with a structural high that could have prevented the alkaline detritus from the Itatiaia and Morro Redondo intrusive bodies from reaching the study area and restricted the supply of sediments from a fluvial system with tributaries on the northern edge. In conclusion, the results of this work reveal that U-Pb ages in detrital zircons reveal a tectonic-driven of the Resende basin sediments. In this way, interpretations of tectonic environments that affected sedimentation require a thorough understanding of the lithological units that compose the basin stratigraphy and factors such as the directions of currents and the presence of structures that compartmentalized sedimentary processes.