The lower Triassic epiclastic and volcanic deposits (Las Cabras and Potrerillos formations), of the northern fields of the eastern productive axis of the Cuyo Basin, are large hydrocarbon reservoirs with a cumulative oil production of more than 12,7 Mm3. Previous reports describe the rifting Triassic deposits from the classical structural and sedimentary approach, without integrating the volcanic environment in a mixed geological model. This paper discusses how the collection of cutting samples, well cores, logs, tests and well production, together with the 3D seismic data, allowed the definition of an integrated model. A volcanic caldera environment in extensional regime is proposed, with low runout ignimbrites in moderately explosive cycles, interacting with a preexisting sedimentary environment. In the Triassic, the volcanic rocks provided the detritus that would be re-transported by the pre-existing and reactivated sedimentary environments, with an evident cyclicity. The study has been focused on the Barrancas area, at the northeastern section of the basin, 16 km south of the city of Mendoza. Two main effusive volcanic centers were determined as two collapse caldera. This model fits the distributions of well production in the area and changes historical correlation of the well logs. This allowed a predictive model to be generated, minimizing the uncertainty of the exploration wells