Nanofósiles calcáreos de la Formación Agrio (Cretácico Inferior) en el sector sudoccidental de la Cuenca Neuquina, Argenti

Marina Lescano, Andrea Concheyro

Abstract


Calcareous nannofossil assemblages recorded in marine rocks of the
Lower Cretaceous Agrio Formation in the southern Neuquén Basin are presented here. The Cerro Birrete
(39º 16.456´S and 70º 5.94´O), Barda Cerro Marucho (39º 26.685´S and 70º 13.015´O) and Cerro Marucho
section (39º 26.443´S and 70º 13.21´O) are analized, being recognized 33 taxa, between them, the reliable
markers are: Clepsilithus maculosus Rutledge and Bown, Eiffellithus striatus (Black) Applegate and Bergen,
Eiffellithus windii Applegate and Bergen, Nannoconus bucheri Brönnimann, Nannoconus circularis Déres and
Achéritéguy. The nannofossil association, of Late Valanginian-Hauterivian age, allow to date of the Agrio
Formation in the area and correlate it with others situated in different localities of the basin.