Santonian-Maastrichtian planktonic foraminifers (Globigerinelloididae, Hedbergellidae, Globotruncanidae and Rugoglobigerinidae) in the Romanian Black Sea offshore

摘要

Forty four planktonic foraminiferal species are now reported from the Santonian, Campanian and Maastrichtian deposits of the Romanian Black Sea offshore. The Late Cretaceous deposits consist of white yellowish limestones of the Unirea Formation [(? Late) Santonian to Early Maastrichtian] and white chalk with flints of the White Chalk Formation ("Middle" to Late Maastrichtian in age). The taxa of the family Globotruncanidae are dominant but within it the plano-convex tests are rare. The most frequent species have biconvex tests. The planispirally enrolled taxa, hedbergellid forms as well as the rugoglobigerinids, are rare. The maximal faunal diversity is encountered during Early - "Middle" Maastrichtian. A local biostratigraphical scale consisting of six biozones is established.