The Perbla area structurally belongs to the Tolmin Nappe, which is the lowermost structural subunit of the Southern Alps in the Slovenia. The studied succession belongs to the Slovenian Basin. The Perbla-Tancar section consists of the Krikov, Perbla and Lower Flyschoid Formations. The Lower Flyschoid Formation in the Perbla-Tancar section begins with blocky basal breccia with marly matrix, overlying the unconformity surface on the Perbla Formation. In the upper part, the formation consists of alternating bedded limestone with cherts and marlstone. Krikov and Lower Flyschoid Formations were investigated in thin sections. In the Krikov Formation, three standard microfacies types were determined: SMF 1, SMF 3 and SMF 12-S. In the Lower Flyschoid Formation, two standard microfacies types have been defined: SMF 3 and SMF 4. I also described and defined microfacies in Perbla 3 section, which was logged by co-menthor in his PhD thesis. In the Lower Flyschoid Formation I have defined standard microfacies SMF 4. The formations of the Perbla-Tancar section reflects deposition in a deep-sea environment. The Jurassic Krikov and Perbla Formations were deposited on the basin plain. The basal breccia of the Cretaceous Lower Flyschoid Formation was deposited via large debris flow. The upper part of the latter formation denotes marlstone pelagic sedimentation interrupted by frequent calciturbidites. Lithoclasts, which were carried by gravity flows, originate from erosion of older rocks, while other grains derive from the cotemporary nearby shallow platform (foraminifers of the Orbitolidae family and other benthic organisms).