A multi-proxy provenance approach using sedimentology, petrology and detrital zircon U-Pb geochronology provides new constrains for the evolution of the Southern Central Andes. The Upper Cretaceous non-marine deposits of the Neuquén Basin referred as Neuquén Group in the central and southern sector of the basin, have been characterized as the first foreland basin associated with the early uplift of the Andean orogen at ca. 100 Ma. However, in the northern sector of the basin, the stratigraphically equivalent Diamante Formation has not been studied in detail yet. This work focuses in the outcrops of the Diamante Formation located between Laguna del Diamante and Atuel River in southern Mendoza Province, Argentina (34°-35°S). The petrographic analysis of sandstones shows high content of volcanic and calcareous lithic fragments suggesting provenance from the underlying sedimentary units and the coeval volcanic arc associated with the onset of an important stage of deformation on the west. Detrital zircons from the base of the Diamante Formation were supplied sources from Upper Jurassic and Lower Cretaceous that were exposed during Upper Cretaceous times, whereas in the top, a high content of Permo-Triassic detrital zircons indicates
The Eocene compressional phase is well known to have contributed to the construction of the Andes orogen at latitudes north of 30° S, but its extension to the south has not been fully studied. Moreover, synorogenic deposits of Eocene age across the foreland are scarce. The Cenozoic Manantiales Basin records the unroofing sequence of the Andes at 32° S. This study focuses on the basal infill of the Manantiales Basin, informally called the Areniscas Chocolate, which has received less attention than the upper infill until now. Sedimentological, geochronological and provenance studies were carried out on this unit. Here, we present the first ages for the Areniscas Chocolate sequence, of ca. 35–39 Ma (maximum depositional age, MDA). This MDA is interpreted as close to its depositional age, which together with their stratigraphic characteristics, allow us both to separate it from the overlying Miocene Chinches Formation and to propose it as an independent lithostratigraphic unit called Río de los Patos Formation (nov. den.). The provenance analysis of the Río delos Patos Formation indicates a sediment input from western sources located in the Coastal Cordillera and Western Principal Cordillera. Facies associations suggest that the Río de los Patos Formation represents the distal synorogenic deposits during the construction of an Eocene relief to the west. Therefore, the Manantiales Basin started during the late Eocene as a distal foreland basin, indicating that Eocene compression reached latitudes as far south as 32° S. Our results shed light into the characterization of the earliest infill of the Manantiales Basin, as well as into the tectonic evolution of the basin.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.