Cenomanian-? early Turonian minimum age of the Chubut Group,Argentina: SHRIMP U-Pb geochronology

摘要

Four new SHRIMP U-Pb zircon ages older than 93 Ma from samples of the two uppermost formations accumulated in two different depocenters (Golfo de San Jorge and Canadon Asfalto basins) of the Chubut Group in central Argentinean Patagonia, establish a pre-late Cenomanian-? early Turonian age for the group. It also confirms a coeval and comparable evolution of the two depocenters, where distal pyro-clastic material was deposited together with fluvial and lacustrine facies.