The Vaca Muerta-Quintuco system in the Puerta Curaco section (northern Neuquén Basin), consists of a 716 m thick shallowing-upward cycle deposited from early Tithonian to early Valanginian. The Vaca Muerta Formation represents a world-class unconventional play since 2010, nevertheless, there is not agreement on the stratigraphic position of the top of Vaca Muerta Formation yet. This contribution provides a stratigraphic analysis of the vertical transition (35 m) between the Vaca Muerta and the Quintuco Formations, including sedimentological, geochemical and mineralogical analysis. The transition interval is characterized by: 1) an increase of calcareous shales compared to the underlying unit 2) a broad and smooth peak of Gamma-Ray associated to high values of K and Th 3) an increase in clay minerals (illite, chlorite and mixed-layered illite/smectite) when compared to the underlying unit 4) relative low values of Mo and U, suggesting a decrease in the organic content and 5) complete dolomitization of the limestones beds. These observations indicate an important change in the paleoenvironmental conditions, suggesting an increase in detrital sedimentation and the emplacement of a mixed siliciclastic-carbonate system. These changes are associated to a pronounced sea-level fall, based on the configuration of regional seismic data. The high-resolution insights derived from this study in Puerta Curaco section may be used to gain further knowledge in the subsurface sections where the lack of core in the key stratigraphic sections hampers such inferences.