New Age Constraints for the Salamanca Formation and Lower Río Chico Group in the Western San Jorge Basin, Patagonia, Argentina: Implications for Cretaceous-Paleogene Extinction Recovery and Land Mammal Age Correlations

A multi-disciplinary geochronologic study of the Salamanca Formation and overlying Rio Chico Group in the western part of the San Jorge Basin finds important Peligran and “Carodnia” zone vertebrate fossil assemblages from coastal BNI and Penas Coloradas exposures are likely older than previously thought and correlate to the early Torrejonian and early Tiffanian North American Land Mammal Ages.