Organic-walled dinoflagellate cysts and calcareous nannoplankton are described from marly intraclasts found in submarine slump deposits within the Lower Oligocene Szaflary Beds exposed in the Leśnica Stream. Their Middle and Late Eocene age implies that the investigated deposits are coeval with the basal deposits of the Podhale Paleogene succession. These Middle and Upper Eocene marl intraclasts were eroded and transported into the flysch basin during the Early Oligocene. They represent the sediments deposited in the northern part of the Podhale Basin that is not exposed in recent times. Paleoenvironmental analysis of microfossils suggests sea-level oscillations during late Middle-Late Eocene (Bartonian–Priabonian) with its maximum during the earliest Late Eocene (earliest Priabonian). A drop of sea surface temperature during Late Eocene is also suggested on the basis of high-latitude microfossil occurrence.