Science and Technology Production
Formación Potrero de los Funes (Cretácico Superior-Paleogeno): una nueva unidad estratigráfica en el sur de la sierra de San Luis
Article
Date:
2019Publishing House and Editing Place:
Asociación Geológica ArgentinaMagazine:
Revista de la Asociación Geológica Argentina, vol. 76 (pp. 199-212) Asociación Geológica ArgentinaSummary
The Potrero de los Funes Formation (Upper Cretaceous - Paleogene): A new stratigraphic unit in the south of Sierra de San Luis. In the southern sector of the Sierra de San Luis outcrops a sedimentary sequence deposited in an intermontane basin, which has been subsident since Cretaceous. In this sector a new stratigraphic unit called Potrero de los Funes Formation has been recognized. It is composed of, at least, one hundred meters of tectonized siliciclastic sedimentary rocks in a typical red bed sequence, which is locally fossiliferous. It outcrops with not visible base and is covered in angular and erosive discordance by the San Roque Formation. Fourteen lithofacies and five facies associations has been recognized, whose interpretation allows to postulate a fluvio-lacustrine sedimentary model. During its sedimentation, the landscape would have been considerably more attenuated than at present and the deposition would have taken place in a single basin conformed by the present depressions of Potrero de los Funes and Las Chacras. The fluvial systems would have flowed toward the south and center of the basin. The source area would have been predominantly rocks from the surrounding basement and sedimentary rocks from the Gigante Group (Lower Cretaceous). Its fossil content includes algae remains, fungi, conchostracans and reworked pollen, all of them with little chronostratigraphic value. So, it is not possible at the moment to adjust their age, which would lies between Late Cretaceous and Paleogene.Key Words
SIERRAS PAMPEANASLACUSTREFLUVIALESTRATIGRAFIA