CAMPANIAN NANNOFOSSIL ZONES IN THE MEDITERRANEAN UPPER CRETACEOUS IN SOFIA BALKAN BETWEEN BUHOVO, JELYAVA AND ELESHNITSA

ABSTRACT. Two lithostratigraphic units of the Mediterranean Upper Cretaceous- Mirkovo and Chugovitsa Formations crops out in the form of a narrow strip in the north-east suburbs of Sofia, between Buhovo, Jelyawa and Eleshnitsa. The subject of the present work are reliable measurement of the thickness of the units and biostratigraphic nannoplankton subdivision of the fossiliferous intervals. Mirkovo Formation is composed of 300 m thick motley limestones and marls. The uppermost 60 m of the unit are composed of marls belonging to the Voden Member of Mirkovo Formation. The upper part of the section is composed of the deposits of Chugovitsa Formation represented by 300 m thick turbidite sequence. Four Campanian nannofossil zones are characterized, from lower to upper: Broinsonia parc