Commune: Chełmek (pow. oświęcimski, woj. małopolskie)
Framework element or context represented:
Stratigraphy of Triassic in the Upper Silesia.
Primary geological/geomorphological interest:
Sequence of the Lower Gogolin Beds - Middle Triassic.
Comparative assessment justification:
One of the best site which can be used for comparative studies of sedimentation in the northern peri-Thetys basin (German basin) in the beginning of Middle Triassic. One of the best outcrops of the sequence of Lower Gogolin Beds in east part of the Upper Silesian region.
Protection status and accessibility:
Proposed for protection, well accessible - situated west to the town Chełmek in recreation area, close to the town cementary.
Character of site: Abandoned quarry.
Area: 0.4 ha
Altitude: 270-280 m a.s.l.
Lithology: conglomerates, breccias, limestones, dolostones
Discipline: Palaeobiology, Palaeoenvironment, Stratigraphy of Phanerozoic
Process Age: Pleistocene, *all periods
Bedrock Age: Triassic, *all periods
Description of primary interest:
Sequence of marine sediments in the Upper Silesian region (basin) represent east part of the northern peri-Tethys basin (German basin) in the beginning of Middle Triassic. The profile of the Lower Gogolin Beds is outcropped in the east and north walls of the quarry 200 m long and 70 m wide, active in the first half of XX century. The Lower Gogolin Beds are some 17 m thick. Several types of carbonate sediments were distinguished here: a) „wave”, slightly marly limenstone („wellenkalk”), b) micritic limestone, c) bioclastic limestone, d) intraformational conglomerate, e) inserts of secondary dolomite (dolomitic limestone). The rocks are aboundant in fossils: brachiopods, gastropods, echinoids, ostracodes, foraminifers as well as bones of vertebrate (mainly fishes and reptiles), which document shallow and warm water environment. Sedimentary structures - lenticular, diagonal and horizontal stratification, fractional granulation, , 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 sediments of the Gogolin Beds in the Silesian region.
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. 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.