Provenance of synorogenic deposits of the Upper Cretaceous-Lower Palaeogene Jarmuta-Proc Formation (Pieniny Klippen Belt, Western Carpathians)

摘要

The Pieniny Klippen Belt contains thickening and coarsening upwards synorogenic sedimentary successions witnessing the collision of the Oravic ribbon continent with the Central Carpathian orogenic wedge after the closure of the Vahic Ocean in the Late Cretaceous to Early Palaeogene. The sedimentary record of this event is represented by flysch/wildflysch deposits of the Maastrichtian-Lower/Middle Eocene Jarmuta-Proc Formation. We present results of the provenance study of these deposits, based on the framework petrography, heavy mineral analysis and mineral chemistry. Turbiditic sandstones were classified as quarzolithic to lithic arenites. Lithic fragments are predominantly composed of carbonate rocks and low- to medium-grade metamorphic and occasional mafic volcanic rocks. The heavy mineral association is composed of both first-cycle derived and recycled ultrastable ErR, garnets and Cr-spinels. The chemistry of the detrital tourmalines and garnets suggests a derivation from various low- to medium-grade metamorphic rocks. Ifigh-pyrope garnets, observed in the eastern part of the PKB, which were derived from high-grade granulites and eclogites, represent probably lower crustal complexes exhumed during rifling of the Vahic Ocean. The Cr-spinels show a mixed harzburgitic and lherzolitic provenance. The harzburgitic Cr-spinels might have been recycled from older exotic conglomerates of the Klape Flysch, thereby representing ophiolitic detritus of the Meliata Ocean. The lherzolitic Cr-spinels might represent a new contribution of ophiolitic detritus delivered from the exhumed subcontinental mantle forming the Vahic oceanic floor.