Within the Carpathian Foredeep, open marine basin evolved into restricted evaporitic basin during the Badenian (Serravallian), and along the Carpathian front chloride sub-basins developed. The studies of foraminifera and calcareous nannoplankton were conducted to obtain new biostratigraphic data which could constrain the age and correlation of the salt deposits between Wieliczka-Bochnia in Poland, and Kalush in the Ukraine. These studies proved that chloride deposits (in the Ukrainian territory also potassium salts) originated generally during the same period corresponding to the Late Badenian NN6 zone and undivided NN6-NN7 zone. The uppermost part of sub-evaporitic beds belongs to the boundary between the NN5 and NN6 zones, although locally (Bochnia Salt Mine) only the NN6 zone was found. This suggests that the lower boundary of salt deposits can be diachronous. Deposits overlying the salt (Chodenice and lowermost part of Grabowiec beds - Bogucice Sands) represent the Late Badenian NN6/NN7 zone. The similarity in age between the folded Middle Miocene strata in Poland (Zgłobice Unit) and the Ukraine (Sambir Unit) implies that they were folded during the same time and that they can represent one tectonic unit, develo ped in front of the advancing Carpathian orogen.