The Neogene-Quaternary infill of the Orava-Nowy Targ Intramontane Basin comprises two tiers showing contrasting lithologies. The Neogene tier is largely composed of claystones and siltstones, whereas the Quaternary tier is dominated by gravels. The two sequences are separated by an erosional surface underlain by a regolith. Deposition of the Neogene sequence took place during subsidence of the basin. No prominent relief existed in the area of the present-day mountains actually surrounding the basin at that time. The regolith started to form at the onset of basin inversion. Still, no prominent relief existed in the present-day mountains. The onset of deposition of Quaternary gravels in the basin corresponds to acceleration of uplift of the surrounding mountains, which has been continuing until now. The Pieniny Klippen Belt has been subject to erosion, at least locally, from the deposition of the basal part of the Neogene sequence filling the Orava-Nowy Targ Basin until present times. In contrast, the Paleogene cover of the Tatra Mts was removed only during the Quaternary.