Upper Jurassic gravity mass flow deposit from the north margin of the Krzeszowice Graben

• Autorzy: Woźniak T.
• Konferencja: XVth International Conference of Young Geologists Her'lany 2014 : Międzybrodzie Żywieckie, Poland, May, 8th-10th 2014
• Języki publikacji: EN

Abstrakty

EN

In the whole Upper Jurassic succession in the vicinity of Cracow area gravity mass flow deposits are observed. They are represented mainly by debris-flows, grain-flows, and other gravity-flows, and were noted by Felisiak (1983), Koszarski (1995), Matyszkiewicz & Krajewski (1996), Matyszkiewicz (1996, 1997), Matyszkiewicz & 0lszewska (2007), Ziółkowski (2007). The studied quarry is situated in the vicinity of Tomaszowice, at the N margin of the Krzeszowice Graben, some 15 km NE of Krakow. The outcrop is about 30 m long and 9 m high. At the base of the outcrop, bedded limestone with cherts is exposed. The limestone is white, varying in shade, beds are 0.2-1 m thick, commonly contains cherts distributed along layer-parallel horizons and numerous dish-like and cup-shaped sponges occupying life position as well as microbial structures. The bedded limestone is overlain by a layer of greenish, plastic marl up to 15 cm thick. The marl rests on irregular top of bedded limestone with denivelation up to 1.5 m. The marl is followed by a 3 m thick layer of fragmental carbonate composed of irregularly distributed zones of massive clast-supported or matrix-supported fabric, which also contain abundant chert fragments. The clasts are irregular in shape and their maximum diameter reaches 0.4 m. The texture, structure and facies relations at Tomaszowice suggest sysnsedimentary origin of the fragmental limestone layer. Microfacies analysis indicates that the sediment at the base of the outcrop is developed as boundstone-wackestone. Siliceous sponges Hexactinellida & Lithistida, and microbial structures represented by thrombolites are the main constituents of boundstone that dominate in thin section. Tubiphytes and Terebella lapilloides are very common. Some of the sponges reveal borings filled by internal calcareous or ferrugineous sediment. The limestone clasts from the upper part of the outcrop are represented by boundstone-packstone, locally grainstone, both microfacies containing Tubiphytes, fragments of bivalves and siliceous sponges and Terebella lapilloides. Overturned sponges, microbial structures and geopetal fillings are common in larger boundstone clasts. Synsedimentary gravity mass flow deposits, like those observed in Tomaszowice outcrop, can be found near the northern margin of the Krzeszowice Graben (e.g. Matyszkiewicz 1996). This position suggests reactivation of a pre-existing fault zone within the underlying Palaeozoic bedrock, which occurred during the Oxfordian (Żaba 1999) as syndepositional deformation. Synsedimentary origin of these fragmental rocks, suggest the age of the margin at Tomaszowice may be dated at the Late Jurassic.

Słowa kluczowe

EN

outcrop; limestone; chert

• Wydawca: Wydawnictwa AGH
• Czasopismo: Geology, Geophysics and Environment
• Rocznik: 2014
• Tom: Vol. 40, no. 1
• Strony: 143--144
• Opis fizyczny: Bibliogr. 8 poz.

Twórcy

autor

Woźniak T.

• AGH University of Science and Technology, Faculty of Geology, Geophysics and Environmental Protection; al. Mickiewicza 30, 30-059 Krakow, Poland

Bibliografia

• 1. Felisiak I., 1983. O strukturach sedymentacyjnych wapieni oxfordu w Forcie Skała w Krakowie. Sprawozdania z Posiedzeń Komisji Naukowych PAN , 25/1, 186–188.
• 2. Koszarski A., 1995. Tradycja a nowoczesność w interpretacji warunków powstawania wapieni górnej jury krakowskiej. Szczególna rola procesów redepozycji. IV Krajowe Spotkanie Sedymentologów , Polskie Towarzystwo Geologiczne, Kraków, 9–22.
• 3. Matyszkiewicz J., 1996. The Significance of Saccocoma-calciturbidites for the analysis of the Polish Epicontinental Late Jurassic Basin: an example from the Southern Cracow-Wielun Upland (Poland). Facies, 34, 23–40.
• 4. Matyszkiewicz J., 1997. Microfacies, sedimentation and some aspects of diagenesis of Upper Jurassic sediments from the elevated part of the Nothern peri-Tethyan Shelf, a comparative study on the Lochen area (Schwabische Alb) and the Cracow area (Cracow-Wielun Upland Poland). Berlinere Geowissenschaftliche Abhandlungen, E21, 1–111.
• 5. Matyszkiewicz J. & Krajewski M., 1996. Lithology and sedimentation of Upper Jurassic massive limestones near Bolechowice, Kraków-Wieluń Upland, south Poland. Annales Societatis Geologorum Poloniae , 66, 285–301.
• 6. Matyszkiewicz J. & Olszewska B., 2007. Osady podmorskich spływów grawitacyjnych pogranicza oksfordu i kimerydu w Ujeździe. Tomy Jurajskie , 4, 109–117.
• 7. Ziółkowski P., 2007. Osady basenów międzybiohermalnych sąsiadujących z południową krawędzią zespołu biohermalnego Ojcowa. Tomy Jurajskie , 4, 119–122.
• 8. Żaba J., 1999. Ewolucja strukturalna utworów dolno paleozoicznych w strefie granicznej bloków górnośląskiego i małopolskiego. Prace PIG , 166, 1–162.