Foraminiferal biostratigraphy and paleoenvironments of the middle Eocene deposits from the northern part of the Tarcău Nappe (Eastern Carpathians, Romania)

Middle Eocene foraminiferal assemblages have been analyzed from three representative sections of bathyal deposits cropping out along the Brodina Valley and Voroneţ Valley in the northern part of the Tarcău Nappe (Eastern Carpathians, Romania). The foraminiferal assemblages are dominated by agglutinated species with tubular forms (Psammosiphonella cylindrica, Nothia spp., Bathysiphon sp.), globular (Saccammina spp., Psammosphaera spp.), coiled (Recurvoides spp., Reticulophragmium spp.) and flattened streptospiral (Paratrochamminoides spp., Trochamminoides spp.). Coarsely agglutinated taxa are characteristic for the “flysch – type” agglutinated foraminiferal biofacies. The depositional setting was probably upper to middle bathyal, as suggested by the abundance of the tubular forms. The morphogroup analyses showed variations in tubular and infaunal morphotypes, suggesting fluctuations in the organic matter input, oxygenation, and disturbing bottom water currents. Based on the presence of Ammodiscus latus, Reticulophragmium amplectens, Haplophragmoides parvulus, Spirosigmoilinela compressa, Psamminopelta gradsteini and the high abundances of Reophax pilulifer, the studied deposits can be assigned to the upper part of the middle Eocene