Lower Cretaceous calcareous nannofossils of the Romanian Carpathian bend

Abstract

We have studied two successions located at the southern end of the Eastern Carpathians. Lithologically, the investigated sections are represented by calcareous turbidites. These successions have been thoroughly sampled (3 samples/1m) for calcareous nannofossil investigations. The oldest studied section is Berriasian in age, while the youngest was sedimented during the late Valanginian-early Hauterivian interval. Across the Valanginian-Hauterivian boundary interval, we identified several nannofossils such as Rucinolithus wisei, Rucinolithus pinnatus, Eiffellithus windii, Diloma galiciense, and Lithraphidites bollii, with biostratigraphic significance. The observed calcareous nannofossil assemblages are mainly composed of Watznaueria barnesiae and taxa largely confined to the Tethyan Realm, such as Nannoconus spp., Cruciellipsis cuvillieri, Calcicalathina oblongata, Diazomatholithus spp. and Rucinolithus spp.