Conodont stratigraphy and sedimentary environment of the Muschelkalk in Upper Silesia

Abstract

The conodont stratigraphy of the Muschelkalk in the Opole area, Upper Silesia, Southern Poland, is the subject of the present paper. Seven conodont zones, three of them containing conodont fauna almost identical with that of corresponding assemblages in the Tethyan Middle Triassic, are recognizable here. The Neospathodus germanicus, N. kockeli and Gondolella excelsa zones comprise the Gogolin; Górażdże and Terebratula beds, as well as part of the Karchowice Beds (Lower Muschelkalk), which correspond to the Lower Anisian, Pelsonian and ,the lowermost Illyrian. Conodont zones "I", "2", "3" and "4" with a conodont fauna typical of the German province are characteristic of the remaining part of the Muschelkalk sequence. These zones include the Tarnowice, Wilkowice and Boruszowice beds (Illyrian through Fassanian). The Muschelkalk/Keuper boundary in Silesia runs in the lowermost Langobardian and, therefore, the "Lettenkohle" series is precisely of this age. A conodont assemblage from the Muschelkalk of Opole Silesia departs from all others known so far in its considerable content of eccentric and bifurcated gondolellids. The presence of some lithological and microfacies types,·the formation of which was connected with environments similar to those of the Great Bahama Bank and of the Persian Gulf, occurring throughout the Muschelkalk of Opole Silesia, is also shown. An analysis of the conodont assemblage allowed to find paleobiogeographical relationships between Silesia and other sedimentary areas of the marine Triassic.