Resumen
The Vaca Muerta Formation in the Cerro Domuyo area shows an interesting intercalationof facies with opposite paleocurrents. The unit is represented by outer ramp to basinal facies with a westward directionof progradation. However, in its middle section, slope deposits correlatable with the Huncal Member, are intercalatedwith slumped strata verging NE. This interval is composed of carbonate facies and it is probably associated with thedevelopment of a slope related to a carbonate platform or a distally steepened carbonate ramp. Based on the ammonoidfauna, the age of the Vaca Muerta Formation ranges from the early Tithonian to the late Berriasian, but it could alsoreach the early Valanginian. The Huncal Member yields representatives of the Substeueroceras koeneni Biozone (lateTithonian), hence its age is older than that proposed in its type locality allowing its correlation with units exposed inthe Chilean territory.