ASGP (2015), vol. 85: 587–626
HOW MANY UPPER TRIASSIC BONE-BEARING LEVELS ARE THERE IN UPPER SILESIA (SOUTHERN POLAND)? A CRITICAL OVERVIEW OF STRATIGRAPHY AND FACIES
Joachim SZULC (1), Grzegorz RACKI (2, 3), Karol JEWUŁA (1) & Jan ŚRODOŃ (2)
1) Institute of Geological Sciences, Jagiellonian University, Oleandry 2a, 30-063 Kraków, Poland; e-mail: joachim.szulc at uj.edu.pl
2) Institute of Geological Sciences, Polish Academy of Sciences, Research Centre in Kraków, Senacka 1, Kraków, Poland; e-mail: ndsrodon at cyf-kr.edu.pl
3) Faculty of Earth Sciences, University of Silesia, Będzińska 60, 41-200 Sosnowiec, Poland; e-mail: grzegorz.racki at us.edu.pl
Szulc, J., Racki, G., Jewuła, K. & Środoń, J., 2015. How many Upper Triassic bone-bearing levels are there in Upper Silesia (southern Poland)? A critical overview of stratigraphy and facies. Annales Societatis Geologorum Poloniae, 85: 587–626.
Abstract: At least three widely separated bone-bearing intervals in the Upper Triassic succession of Upper Silesia, ranging in age from the Carnian to Rhaetian (i.e., in the interval of 25 Ma), are presented in papers by the Warsaw research group, led mainly by Jerzy Dzik and/or Grzegorz Niedźwiedzki. The stratigraphic arguments are reviewed for the vertebrate localities studied so far, in particular for the well-known middle Keuper sites at Krasiejów and Lipie Śląskie, to show that the previously proposed age assignments are still inadequately documented and questionable. This unreliability is exemplified by the evolving stratigraphic correlation of the fragmentary Silesian sections (8–18 m thick) with informal subsurface units from central-western Poland and with the German standard succession, ultimately not corroborated by comparison with the composite reference succession of the Upper Silesian Keuper, including new profiles (ca. 260 m thick) from the Woźniki K1 and Patoka 1 wells. Based on a multidisciplinary stratigraphic study covering consistent litho-, bio-, climato- and chemostratigraphic premises, focused on the regional reference section, two bone-bed levels only are recognized in the Patoka Marly Mudstone-Sandstone Member (= Steinmergelkeuper) of the Grabowa Formation, not very different in age (Classopollis meyeriana Palynozone; probably IVb Subzone): (1) the localized Krasiejów bone breccia level (early Norian in age) in the Opole region, and (2) the far more widely distributed Lisowice bone-bearing level (middle Norian) in a vast alluvial plain (braided to anastomosing river system) during the Eo-Cimmerian tectonic-pluvial episode. As a consequence of the principal uncertainties and controversies in Upper Triassic terrestrial stratigraphy, this is still a somewhat preliminary inference. Typical skeletal concentra- tions of a combined hydraulic/sedimentologic type, related to fluvial processes, are common in the Upper Silesian Fossil-Lagerstätten, although factors governing preservation are probably important, as well.
Manuscript received 25 August 2015, accepted 9 December 2015
