Provenance of the Upper Triassic siliciclastics of the Mecsek Mountains and Villány Hills (Pannonian Basin, Hungary): constraints to the Early Mesozoic paleogeography of the Tisza Megaunit

Abstract

The Tisza Megaunit in the Southern Pannonian Basin formed part of the southern margin of the European Plate in the Early Mesozoic era. Its exact paleo-position and relation to other structural blocks is disputed for a long time. Detrital zircon U–Pb dating, heavy mineral analysis and petrographical examination of Carnian to Pliensbachian sandstone members lead to better understanding of the provenance of clastic deposits after the Ladinian–Carnian carbonate to siliciclastic facies shift in the Southwestern Tisza Megaunit. Investigations allow for constraining its paleogeographic relation to adjacent units. The Carnian and Pliensbachian siliciclastics of the Villany Hills derive from inside the Southwestern Tisza Megaunit, i.e. the medium-grade polymetamorphic rocks of the adjacent Slavonian Mountains or similar basement fragments. The Upper Triassic clastic deposits of the Mecsek Mountains most likely derive from Variscan felsic plutonic rocks of the local basement or partially from the Southern/Southwestern Bohemian Massif. About 200 Ma zircon U–Pb ages are tentatively interpreted as traces of synsedimentary distal volcanism in the Central Atlantic Magmatic Province.