WISŁA (VISTULA RIVER VALLEY NATURE RESERVE)



Commune: Wisła (pow. cieszyński, woj. śląskie)

Framework element or context represented:
Erosional advanced natural processes in Flysch Carpathians.

Primary geological/geomorphological interest:
Waterfalls in the contact zone of two flysch formations.

Comparative assessment justification:
Numerous rocky erosional forms in different stages of evolution generated in the contact zone of two different flysch formations. Exeptional hydrographical area in Western Carpathians - Barania Góra range.

Protection status and accessibility:
The Vistula head streams are protected as a nature reserve (1959) situated within Beskid Śląski Landscape Park.

Character of site: Erosional forms.

Area: 17.61 ha

Altitude: 830-1100 m a.s.l.

Lithology: sandstones, conglomerates, breccias, shales, silstones, claystones

Discipline: Geomorphology, Stratigraphy of Phanerozoic

Process Age: *all periods

Bedrock Age: Cretaceous, *all periods




Description of primary interest:
The White Vistula and Black Vistula are the headwater streams of the Vistula - the main Polish river. Long sections of these valleys from rocky walls and steps representing a continuous profile of monoclinally dipping Upper Cretaceous deposits. The area is situated within the Silesian Unit section of transition of the flysch from Upper Godula Beds to the Lower Istebna beds. Upper Godula Beds of the White Vistula valley are formed a set of intercalating thin-bedded, small-grained sandstones and hard shales. In high part of valley these sediments pass to Lower Istebna Beds. The sequence of the Istebna Beds is best developed in the Black Vistula valley. It is typical sediment of fluxoturbidites: coarse-grained and thick-bedded sandstones, conglomerates and mudstones. The Vistula streams in the western slopes of Barania Góra Range are a particular example of a great concentration of erosional forms, especially fall steps in the Outer Carpathians. The cascades and other types of erosional forms are in different stages of development, depending on lithology and on various strikes related to streamflow direction. The largest sets of 5 m high fall steps were formed in the bottom thick layers of sandstones and conglomerates of the Istebna beds mostly in the White Vistula bottom. The contact of two different flysch formations is an important factor controlling the origin of waterfalls.

Literature:

ALEXANDROWICZ Z. 1976–The waterfalls of the White and Black Wistulas (English sum.). Ochr. Przyr. 35: 281-235.     ALEXANDROWICZ Z. 1994–Geologically controlled waterfall types in the Outer Carpathians. Geomorphology 9: 155-165.     ALEXANDROWICZ Z. 1997–Waterfall in the Polish Carpathians (English sum.). Chrońmy Przyr. Ojcz. 53(4): 39-57.     ALEXNADROWICZ Z., POPRAWA D., RĄCZKOWSKI W. 1999–Stratotypes and other important geosites of the Polish Carpathians. Pol. Geol. Inst. Special Papers 2: 33-46.     BURTANÓWNA J., KONIOR K., KSIĄŻKIEWICZ M. 1937–Mapa geologiczna Karpat Śląskich (in Polish only). Pol. Akad. Umiejętności. Wyd. Śląskie.     UNRUG R. 1963–Istebna Beds - a fluxoturbidity formation of the Carpathian Flysch. Rocz. Pol. Tow. Geol. 33: 49-92.     ZIĘTARA T., LIS J. 1986–Part of geological structure in evolution of waterfalls in the Flysch Carpathians. Fol. Geogr. 18: 31-50.