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

• We obtained 4 new zircón SHRIMP ages from the youngest units of the Chubut Group.
• They represent the first SHRIMP radiometric ages from this group.
• The result is a Cenomanian-? early Turonian mínimum age for the group.
• These are ages older than the minimum age previously thought.
• A coordination between absolute and paleontologic data is urgently needed.

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 Cañadón 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 pyroclastic material was deposited together with fluvial and lacustrine facies.