Commune: Krzeszowice (pow. krakowski, woj. małopolskie)
Framework element or context represented:
Middle/Upper Jurassic sediments and biozones in the Polish Jura Chain.
Primary geological/geomorphological interest:
Fossiliferous deposits of Callovian/Oxfordian boundary.
Comparative assessment justification:
The stratigraphy sequence documents the boundary Middle/Upper Jurassic typical of the Submediterranean province with influences of both Boreal and Tethyan elements.
Protection status and accessibility:
Nature monument established in 1970 and qualified now on a documentary site is located within the Tenczynek Landscape Park. The area is accessible by tourists-didactic trail.
Character of site: Abandoned quarries.
Area: 4 ha
Altitude: 330 m a.s.l.
Lithology: sandstones, conglomerates, breccias, limestones, marls, sands
Discipline: Palaeobiology, Palaeoenvironment, Stratigraphy of Phanerozoic
Process Age: *all periods
Bedrock Age: Cretaceous, Jurassic, *all periods
Description of primary interest:
Middle/Upper Jurassic deposits rich in fossils are accessible in small outcrops situated within two old neighbouring quarries on the Czerwieniec Hill, about 2 km to the east of Tenczynek village. The lower part of the sequence is visible now in one outcrop situated in the quarry near the old coal mine “Nowa Krystyna”. The same locale name has the mentioned quarry. The coarse-grained sand and sandstones with an admixture of quartz pebbles forming intercalations of conglomerates occur at the entry to the quarry. These deposits are cross-bedded with the ferruginous matrix and are interpreted as fluviatile sediments accumulated just before the Middle Jurassic transgression. Marine deposits crop out in both quarries and are represented by sand and sandy limestones abounding in brachiopods, belemnites, bivalvesand ammonites indicating the Callovian age. A thin layer of limonithic limestone with stromatolit crowns these deposits. White and red marls rich in foraminifers and ammonites typical of the lowermost Oxfordian cover them. Marly limestones intercalated with platy limestones rich in ammonites and sponges close this profile. The described sequence as important from the stratigraphical and palaeobiogeographical point of view is most representatives for the Cracow Upland.
Literature:
ALEXANDROWICZ Z., DRZAŁ M., KOZŁOWSKI S. 1975–A cataloque of inanimate nature reserves and monuments in Poland (English sum.). Studia Naturae B, 26, 298 pp. RÓŻYCKI S.Z. 1953–Górny dogger i dolny malm Jury Krakowsko-Częstochowskiej (Polish and Russian only). Pr. Inst. Geol. 17, 412 pp. SZULCZEWSKI M. 1968–Jurassic stromatolites of Poland (English sum.). Acta Geol. Pol., 18: 1-100.