INVESTIGADORES
SPALLETTI Luis Antonio
congresos y reuniones científicas
Título:
Large-scale depositional and palaeogeographic reconstruction of the Pilmatué Member (Neuquén Basin): understanding from the source to the sink
Autor/es:
SCHWARZ, E.; VEIGA, G.; ECHAVARRÍA, C. Y SPALLETTI, L.
Lugar:
Buenos Aires
Reunión:
Congreso; AAPG International Conference and Exhibition; 2019
Institución organizadora:
American Association of Petroleum Geologists
Resumen:
Sedimentary basins located at the margins of continents act as the final base level for midcontinentregions that are sometimes located 1000s of kilometers away from the basin, and thiscondition of exceptionally long sediment transfer zones is probably reinforced in supercontinents,such as Gondwana. One of the most prominent marine basins in southwestern Gondwana during theJurassic and Early Cretaceous was the Neuquén Basin (west-central Argentina), but its role as thesediment repository of far-flung source areas has not been extensively considered. This contributionprovides the first detailed detrital zircon U-Pb geochronology of the Valanginian - HauterivianPilmatué Member of the Agrio Formation, which is combined with sedimentology andpaleogeographic reconstructions of the unit within the Neuquén Basin for a better understanding ofthe fluvial delivery systems. Our detrital-zircon signatures suggest that Triassic-Permian zirconpopulations were probably sourced from the adjacent western sector of the North PatagonianMassif, whereas Early Jurassic, Cambrian, Ordovician, and Proterozoic grains were most likelyderived from further east, in the eastern sector of the North Patagonian Massif, as well as presentlyremote terranes such us the Saldania Belt in southern Africa. We thus propose a Valanginian-Hauterivian longitudinal delivery system that, starting in the mid-continent region of southwesternGondwana and by effective sorting, was bringing fine-grained or finer caliber sand to the Neuquénbasin shoreline. This delivery system was probably active (though not necessarily continuously)from Early Jurassic to Early Cretaceous until finally coming to an end during the Atlantic break-upin the latest Early Cretaceous.
