Commune: Chrzanów (pow. chrzanowski, woj. małopolskie)
Framework element or context represented:
Stratigraphy of Triassic in the Upper Silesia.
Primary geological/geomorphological interest:
Full sequence of the Gogolin Beds – Middle Triassic.
Comparative assessment justification:
The best site for comparative studies of the peri-Tethys basin development with other regions, for example with central part of the German basin, as well as with eastern margin of the northern peri-Thetys basin in the Świętokrzyskie (Holy Cross) Mts., central Poland.
Protection status and accessibility:
Proposed for protection, well accessible - located near the road Chrzanów-Pogorzyce. It is only one outcrop in the SE part of the peri-Tethys basin which can be formally protected by low. Other quarries situated in the western part of region are still active.
Character of site: Abandoned quarry.
Area: 2.5 ha
Altitude: 330-365 m a.s.l.
Lithology: conglomerates, breccias, limestones
Discipline: Palaeobiology, Geomorphology, Palaeoenvironment, Stratigraphy of Phanerozoic
Process Age: *all periods
Bedrock Age: Triassic, *all periods
Description of primary interest:
Site representative for the lower part of Middle Triassic sediments (Muschelkalk) is situated in east part of the northern peri-Thetys basin (German basin). The sequence of the Gogolin Beds is outcropped in the quarry 300 m long and 70-90 m wide, active in the first half of XX century. The Gogolin Beds (Lower Anisian) are 34,8 m thick and consist of 95 layers studied in details. Several types of carbonate sediments were distinguished in this sequence: a) „wave”, slightly marly limenstone („wellenkalk”), b) micritic limestone, c) bioclastic limestone, d) intraformational conglomerate, e) inserts of cavernous dolomitic limestone. The rocks are aboundant in fossils: brachiopods, gastropods, echinoids, ostracodes, foraminifers, trace fossils as well as bones of vertebrate (mainly fishes and reptiles), which document shallow and warm water environment. Commonly observed sedimentary structures - lenticular, diagonal and horizontal stratification, fractional granulation (of mainly biodetrital material), bioturbations, slump structures, „ball and pillow” structures, erosional furrows as well as horizons of regional erosion (intraformational breccias) – are evidences of violent tectonic modification of the basin during sedimentation. Regional scale of the tectonic events – as earthquake or tsunami - and gradual, slow tectonic evolution of the whole Silesian part of the basin is proofed by uniform sequence of the Gogolin Beds observed in outcrops of this region. In the same quarry some fossil karst forms are observed. In one of the Tertiarry karst shafts pisoides (cave ooids, „cave pearls”) were found and studied.
Literature:
ASSMAN P. 1944–Die Stratigraphie der Oberschlesischen Trias. Teil 2: Der Muschelkalk. Abn. Reichs. Bodenforsch., N.F. 208, pp. 124. CHUDZIKIEWICZ L. 1983–Sedimentation of the Gogolin Beds in the eastern margin of the Upper Silesian Coal Basin (Southern Poland) (English sum.). Studia Geol. Pol. 75: 7-44. CHUDZIKIEWICZ L. 1975–Intraformational conglomerates in the Gogolin Beds (Middle Triassic, Southern Poland). Ann. Soc. Geol. Pol. 45, 1: 3-20. GRADZIŃSKI R., RADOMSKI A. 1976–Cave ooids in a Tertiary karst shaft at Pogorzyce, Southern Poland. Acta Geol. Pol. 26, 1: 395-403. SIEDLECKI S. 1952–Utwory geologiczne obszaru pomiędzy Chrzanowem a Kwaczałą (Polish and Russian only). Biul. Inst. Geol. 60, pp. 153. SZULC J. 2000–Middle Triassic evolution of northern peri-Thetys area as influenced by early opening of the Tethys ocean. Ann. Soc. Geol. Pol. 70, 1: 1-48. URBAN J. 1997–Outcrops of Triassic sedimentary rocks proposed for protection in Chrzanów district (Silesian Upland) (English sum.). Chrońmy Przyr. Ojcz. 53, 4: 117-121. ZAWIDZKA K. 1975–Conodont stratigraphy and sedimentary environment of the Muschelkalk in the Upper Silesia. Acta Geol. Pol. 25, 2: 217-246.