The Yalguaraz Formation, Late Pateozoic of the Argentine Cordillera Frontal. Biostratigraphy, Paleoenvironments and Paleogeography

Abstract

?The Yalguaraz Formation, Late Pateozoic of the Argentine Cordillera Frontal. Biostratigraphy, Paleoenvironments and Paleogeography?. The first paleontological record of the Yalguaraz Formation in Argentine Cordillera Frontal are described and showed. They are Fedekurtzia argentina Archangelsky, Austroneilsonia sp., aff. Cosmomya and Orchesteropus atavus Frenguelli, while Spiriferacea indet. and Nuculacea indet. are listed.

The characteristics of the stratigraphic profil shown a predominart marine environment for this deposits. The paleogeographic meaning of the fossil record give to this unit an accentuate gondwanic character. The position of the sequence in the regional biostratigraphic context is analized. A late upper Carboniferous age to the Yalguaraz Formation is suggested.