Berriasian breccia and calcarenite overlying the Biancone limestone are dated and descibed as the Bohinj Formation. The microfacies analysis of the breccia clasts reveals that the main source area of the resedimented limestone was a penecontemporaneous carbonate platform (named the Bohinj Carbonate Platform) that developed on top of a nappe stack during the early emplacement of the internal Dinaric units onto the continental margin. The platform correlates regionally with genetically similar isolated carbonate platforms, e.g., with the Plassen Carbonate Platform in the Northern Calcareous Alps and the Kurbnesh Carbonate Platform in Albania.
Three representative sections of the Tolmin Basin were dated with radiolarians. The maximum time interval of radiolarian cherts was determined to span from the late Bajocian to the early Tithonian and thus correlates well over the entire western Tethys. The intrabasinal distribution of radiolarian cherts demonstrates, that sedimentation rates were primarily determined by the redeposition of pelagic sediments and that considerable stratigraphic gaps may occur even in distal basinal settings.