The different types of calcareous exotic clasts (fragments of pre-existing rocks), embedded in the Paleocene siliciclastic deposits of the Istebna Formation from the Beskid Mały Mountains (Silesian Unit, Western Outer Carpathians), were studied and differentiated through microfacies-biostratigraphical analysis. Calcareous exotics of the Oxfordian- Kimmeridgian age prevail, representing a type of sedimentation comparable to that one documented for the northern Tethyan margin. The Tithonian exotic clasts (Štramberk-type limestones), which are much less common, were formed on a carbonate platform and related slope. The sedimentary paleotransport directions indicate the Silesian Ridge as a main source area for all exotics, which were emplaced in the depositional setting of the flysch deposits. The exotics constitute a relatively rare local component of some debrites. Proceedings of the sedimentological facies analysis indicate that these mass transport deposits were accumulated en-masse by debris flows in a deep-water depositional system in the form of a slope apron. Exotics prove that clasts of the crystalline basement and, less common, fragments of the sedimentary cover, originated from long-lasting tectonic activity and intense uplift of the source area. Mass transport processes and mass accumulation of significant amounts of the coarse-grained detrital material in the south facial zone of the Silesian Basin during the Early Paleogene was due to reactivation of the Silesian Ridge and its increased denudation. Relative regression and erosion of the emerged older flysch deposits were also forced by this uplift. These processes were connected with the renewed diastrophic activity in the Alpine Tethys.

In the Late Jurassic, the rifting process led to the disintegration of the southern margin of the North European Platform and to the opening of the Outer Carpathian flysch basin sedimentary system. The initial sediments accumulated in the northern part of the basin are related to both the destruction and resedimentation of older platform deposits. Since the sedimentary succession of this pre-flysch phase was consumed by the Miocene subduction, its only traces are represented, nowadays, by clasts preserved as exotics in the succeeding flysch deposits. Our analysis of foraminifers as well as calcareous and organic dinoflagellate cysts found in these exotics confirms the Oxfordian-early Kimmeridgian timing of the platform phase that preceded the opening of the flysch basin. The exotics are represented by three main facies types: sponge-microbial limestones, oncoid-intraclastic-Crescentiella limestones and fine-grained, biodetrital limestones with Saccocoma. These deposits are related to mid-ramp to outer-ramp settings. The land influence was rather weak, and these sedimentary settings were dominated by pelagic/hemipelagic accumulation. The studied facies are similar to facies types widely distributed over the northern shelf area of the Western Tethys (e.g., extra-Carpathian southern Poland, Carpathian Foredeep basement, southern Germany). In turn, coeval strata known from the part of the Magura Basin and of the Penninic-Pieninic Ocean, which were situated in more southern part of the Tethys, yielded different microfacies reflecting significant differences between the sedimentary settings of the study area and its southern extensions.

A small group of Tithonian planktonic ciliates, little-known in the area of the Polish Outer Carpathians, has been recorded in exotic limestones from the western part of the Silesian Nappe. Eleven species of the family Chitinoidellidae Trejo, 1975, belonging to the genera Chitinoidella, Daciella, Dobeniella, Longicollaria and Popiella are described here. The majority of studied samples have been assigned to the Boneti Subzone of the Chitinoidella Zone. Exotics with chitinoidellids represent environments which can be interpreted as platform margin reefs, slope of platform and inner platform

Abstract:The stratigraphic position of the Goryczkowiec Sandstone reflects the Paleocene ridge geodynamics in the Outer Carpathian basins. The Goryczkowiec Sandstone was deposited on the slope of a ridge, known as the Subsilesian Sedimentary Area that originated during reorganization of the Outer Carpathian realm. A Paleocene age of this sandstone, documented clearly by autochthonous foraminiferal and algal assemblages indicates the time of the final formation of the Subsilesian Ridge. Abundant calcareous material of biogenic origin was transported by turbidity currents into deeper zones. This material includes fragments of carbonate buildups represented by algae, bryozoans and other organisms growing in the shallower part of the ridge. The Goryczkowiec Sandstone, previously known as the Szydłowiec Sandstone, is here redefined as a new lithostratigraphic unit within the Subsilesian Sedimentary Area in the marginal Outer Carpathians in Poland. The new name clarifies the ambivalence in the lithostratigraphic nomenclature.

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