Commune: Porąbka (pow. bielski, woj. śląskie)
Framework element or context represented:
Stratigraphy and tectonics of marginal northern zone of the Carpathians.
Primary geological/geomorphological interest:
Miocene deposits altered with those of the Sub-Silesian Unit, a large olistostrome consisting of different members of the Carpathian flysch.
Comparative assessment justification:
The geosite is an important point indicating the age of the finally thrusting of Carpathian nappes. Klippes of crystalline rocks, Jurassic limestones and Cretaceous-Paleogene marls and limestones described in the vicinity of Andrychów (Andrychów Klippen Succession - protected outrops in Targanice and Inwałd) considered as olistholites.
Protection status and accessibility:
Proposed as documentary site.
Character of site: Natural outcrops.
Area: 1 ha
Altitude: 400 m a.s.l.
Lithology: granitoids, gneisses, sandstones, limestones, marls, shales, silstones, claystones
Discipline: Palaeobiology, Palaeoenvironment, Stratigraphy of Phanerozoic
Process Age: *all periods
Bedrock Age: Neogene, Paleogene, Cretaceous, *all periods
Description of primary interest:
In the profile of the Domaczka stream there are exposures of Cretaceous, Palaeocene and Eocene marls and shales of the Sub-Silesian series. Chaotically arranged Miocene shales containing blocks of limestones, marls, gneiss, granites and other crystalline rocks rest on the folded marls of the Sub-Silesian Unit. They originate from a ridge delimiting the Sub-Silesian zone from the north. There are also exposures of shales and mudstones with singular inserts of sandstones. These deposits contain the mixed fauna, which represents a wide age interval from the Palaeocene (even Cretaceous) to the Upper Eocene likely with some Miocene species. Yet, the foraminifera sampled point to the Upper Senonian while the calcareous nannoplankton consists of badly preserved Paleogene forms. Grey marly shales with inserts of sandstones contain assemblages of foraminifera of the Barremian and Upper Senonian while the calcareous nannoplankton corresponds with the age interval from the Paleocene to the Recent. Based on sedimentological and micropaleonotological studies, it is believed that the deposits identified in the Domaczka stream profile constitute an olistostrome, consisting of material originating from various members of the Carpathian flysch among the deposits of the Lower Miocene. The described sequence is considered as a new tectonic unit at northern border of Carpathians.
Literature:
ALEXANDROWICZ Z., POPRAWA D., RĄCZKOWSKI W. 1999–Stratotypes and other important geosites of the Polish Carpathians. Pol. Geol. Inst., Spec. Papers, 2: 33-46. KOSZARSKI L. 1992–Olistostromowa natura skałek andrychowskich (Polish only). Spraw. z Pos. Kom. Nauk Geol. PAN, Oddz. W Krakowie 34: 217-220. KOTLARCZYK J. (ed.) 1985–Guide to excursion Carpatho-Balcan. Assoc. 13 Congress, Cracow, Poland. KSIĄŻKIEWICZ M., LISZKOWA J. 1972–On the beds underlying the Andrychów Klippen Western Carpathians (English sum.). Rocz. Pol. Tow. Geol. 42, 2-3: 239-269. WÓJCIK A., OLSZEWSKA B., GARECKA M., SZYDŁO A. 1996–Profil potoku Domaczka i jego znaczenie dla stratygrafii i tektogenezy Karpat (in Polish). Przewodnik LXVII Zjazdu Pol. Tow. Geol. (67th Annual Meeting of Polish Geological Society). Western Beskidy Mts. - new approach to geological structure and natural resources: 82-92. WÓJCIK A., SZYDŁO A., MARCINIEC P., NESCIERUK P. 1999–Folded Miocene of the Andrychów region - new tectonics unit. Prace Państw. Inst. Geol. 168: 231-248.