Provenance of the Bosnian Flysch
1661-8726/08/01S031-24 Swiss J. Geosci. 101 (2008) Supplement 1, S31–S54 DOI 10.1007/s00015-008-1291-z Birkhäuser Verlag, Basel, 2008 Provenance of the Bosnian Flysch TAMÁS MIKES 1, 7, *, DOMINIK CHRIST 1, 8, RÜDIGER PETRI 1, ISTVÁN DUNKL1, DIRK FREI 2, MÁRIA BÁLDI-BEKE 3, JOACHIM REITNER 4, KLAUS WEMMER 5, HAZIM HRVATOVIć 6 & HILMAR VON EYNAttEN 1 Key words: Dinarides, Adriatic plate, ophiolite, flysch, Cretaceous, provenance, geochronology, biostratigraphy, mineral chemistry ABSTRACT Sandwiched between the Adriatic Carbonate Platform and the Dinaride olitic thrust sheets and by redeposited elements of coeval Urgonian facies reefs Ophiolite Zone, the Bosnian Flysch forms a c. 3000 m thick, intensely folded grown on the thrust wedge complex. Following mid-Cretaceous deformation stack of Upper Jurassic to Cretaceous mixed carbonate and siliciclastic sedi- and thermal overprint of the Vranduk Formation, the depozone migrated fur- ments in the Dinarides. New petrographic, heavy mineral, zircon U/Pb and ther towards SW and received increasing amounts of redeposited carbonate fission-track data as well as biostratigraphic evidence allow us to reconstruct detritus released from the Adriatic Carbonate Platform margin (Ugar Forma- the palaeogeology of the source areas of the Bosnian Flysch basin in late Me- tion). Subordinate siliciclastic source components indicate changing source sozoic times. Middle Jurassic intraoceanic subduction of the Neotethys was rocks on the upper plate, with ophiolites becoming subordinate. The zone shortly followed by exhumation of the overriding oceanic plate. Trench sedi- of the continental basement previously affected by the Late Jurassic–Early mentation was controlled by a dual sediment supply from the sub-ophiolitic Cretaceous thermal imprint has been removed; instead, the basement mostly high-grade metamorphic soles and from the distal continental margin of the supplied detritus with a wide range of pre-Jurassic cooling ages.
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