Revised Middle and Late Triassic radiolarian ages for ophiolite mélanges: implications for the geodynamic evolution of the northern part of the early Mesozoic Neotethyan subbasins

Abstract. – The study is based on the radiolarian assemblages of five radiolarite outcrops and two boreholes from the Darnó and Szarvask Complex, Hungary, and three radiolarite sections from the western Vardar Ophiolitic Unit in Ser-bia. These investigated sections belong to a Mesozoic volcano-sedimentary mélange belt that can be followed from the Hellenides, through the Dinarides to the western Carpathians. Samples from radiolarite localities in the Darnó and Szarvask Complex contain a mixture of Middle Triassic (Illyrian to Longobardian) and Upper Triassic (Carnian) fairly poorly preserved radiolarian assemblages. Radiolarite samples from the western Vardar Ophiolitic Unit (Gostilje, Krš Gradac and Bukovi) yielded poorly preserved Upper Triassic (Carnian-?Norian) radiolarians. Co-occurrences of Middle and Upper Triassic radiolarian specimens in Darnó and Szarvask Complex suggest resedimentation during the Carnian or later. One new radiolarian species (Baumgartneria szarvaskoensis n. sp.) is described herein from the Darnó and Szarvask Complex. Révision des âges des radiolaires des mélanges ophiolitiques du Trias moyen et supérieur: implications pour l’évolution géodynamique de la partie nord des sub-bassins téthysiens du Mésozoïque inférieur Mots-clés. – Trias, Complexe de Darnó et de Szarvask, Radiolaires, Mélange ophiolitique, Néotéthys de l’Ouest. Résumé. – Cette étude est basée sur des assemblages de radiolaires de cinq affleurements de radiolarites et de deux fora