Abstract. The planktonic foraminifera assemblages recovered from two cores drilled in Cluj-Napoca (NW Transylvanian Basin) demonstrate connections of the basin to the open seas before the middle Badenian evaporite deposition. Assemblages suggest clear changes in the environments, with an initial transgressive trend, followed by a decrease in the rate of sea-level rise, and finally a sea-level fall. The occurrence of planktonic foraminifera (mainly Globorotalia) offers a good potential for correlation of the pre-evaporitic interval with the uppermost Langhian and can be used for tracing the early-middle Badenian boundary.

Triassic, Upper Jurassic and upper Lower Cretaceous sedimentary formations were previously studied from the Transylvanian Depression basement, but the presence of lowermost Cretaceous (Berriasian-Valanginian) has not been confirmed paleontologically. The carbonate sequence cored from a borehole drilled in the central part of the Transylvanian Depression yields microfossil assemblages dominated by benthic foraminifera. These new data unequivocally document the presence of characteristic Berriasian-Valanginian taxa in these deposits.