Fil: Tunik, Maisa. Universidad Nacional de Río Negro. Instituto de Investigación en Paleobiología y Geología. Río Negro, Argentina.Fil: Vera, Bárbara. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales (IANIGLA-CONICET); Argentina.Fil: Cerdeño, Esperanza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales (IANIGLA-CONICET); Argentina.During the decade of 1980, fossil mammals were recovered from an unnamed lithostratigraphic unit in Agua de Flores (south Mendoza Province). These fossils allowed recognizing a middle Eocene age for the sediments for the first time in this provincial area. Later, new discoveries in Cenozoic deposits of a very near locality, Agua de Isaac, confirmed the presence of middle Eocene levels in this zone. A little southern, a Tertiary geologic unit, thePuesto Fortunata Formation, had been defined at Anfiteatro Liu Malal locality,but without assigning a precise age to it within the Cenozoic. In this context, the objective of this contribution deals with the correlation of these different Cenozoic deposits within a regional framework. Based on lithological characterization, we consider them to correspond to the same unit, the already defined Puesto Fortunata Formation, which is assigned to middle Eocene based onpaleontological content.