U–Pb detrital zircon ages in the Lajas Formation at Portada Covunco: Maximum depositional age and provenance implications for the Neuquén Basin, Argentina

摘要: Abstract The Lajas Formation of the Neuquen Basin (Argentina) was deposited mainly during Middle Jurassic but with a highly diachronic pattern. exact time elapsed in deposition this unit remains controversial and depends on location within basin. Particularly Portada Covunco locality, north Huincul High, debate age persists. has been assigned by sequence stratigraphy, palynological, magnetostratigraphic studies. Moreover, previous studies suggest that locality is composed two depositional sequences (Sq1 Sq2) change composition sandstone, indicating different areas sedimentary supply. new U–Pb data (LA-ICP-MS) detrital zircons allows us to define maximum approximately 163 Ma for Sq1 162 Ma Sq2, suggesting Callovian studied area. Furthermore, we propose provenance pattern dominated ages from Permian–Triassic (peak at 264, 244 215 Ma), derivation predominantly North Patagonian Massif magmatic units; while Sq2 shows associated uplift exhumation units located southwest margin basin end Jurassic. Interestingly, it not possible rule out High may be related supply area; probable resulted an effective physical barrier limited sediment input extreme southeast Sq2.