Depositional setting of the Oligocene sequence of the Western Carpathians in the Polish Spisz region – a reinterpretation based on integrated palynofacies and sedimentological analyses.

Abstract

The research on the Oligocene succession of the Central Carpathian Paleogene Basin (CCPB) in the Kacwin region focused on sedimentological and palynofacies analyses. Observations were carried out in natural exposures along three streams flowing in the Polish Spisz: Kacwinianka, Łapszanka and Kacwiński. Three main groups of lithofacies have been distinguished: coarse-grained, mixed and sandy-grained, and fine-grained. The lithofacies are characterized by variable sedimentary structures, e.g. massive structure, horizontal lamination, ripple cross-lamination, hummocky cross-stratification, deformation structure. Sedimentological analyses showed that structures typical for turbidity currents and those characteristic of relatively shallow deposition (HCS, wave ripples) could coexist in the investigated succession interpreted as typical for turbidity currents influenced by storm waves. This indicates relatively shallow-water environments. The palynofacies analysis enabled identification of the following components: black wood, brown wood, cortex, resin, sporomorphs, cuticle, algae, dinoflagellates and AOM. A high proportion of black wood and low diversity of components point to an origin related to turbidity currents. Furthermore, results of the palynofacies analysis have allowed determining that, during the deposition of the CCPB sediments in the Polish Spisz area, the distance between the deposition area and the source area became relatively large. The biostratigraphic analysis of dinoflagellate cysts from the Podhale Basin (Szaflary, Zakopane, and lower Chochołów beds) indicates an Early Rupelian age. Moreover, kerogen analysis in the UV was applied for the first time to study the CCPB succession. As a result, reworking was documented, so far unrecognized by other methods, and the mutual verification of the obtained results was possible