Research for this thesis took place in the Logatec area along the road section between Logatec and the highway connection. In this area limestone layers are located, including a filled in Karst cave on the right side towards south-west, which developed out of the same limestone layers. This thesis describes in more detail the structure and texture of the cave sediments and cretaceous limestone as well as their mineralogical composition. The profile as well as the powder X-ray diffraction analysis has been made for the cave sediments and cretaceous limestone. The results classified the cave sediments as clastites, namely quartz and bauxite breccias and conglomerates, as well as sandstones sometimes mixed with flowstone as the indigenous material. I have also researched the cretaceous limestone, which incurred by sedimentation in the Dinaric Carbonate Platform area and contains many fossil aggregates such as miliolid foraminifera, orbitoline, fragments of gastropods and bivalves as well as peloids. Sedimentation took place in the shallow-water environment, namely the lagoon and coastal parts as well as the more edge parts of the platform.