The lithological and micropaleontological study of samples collected from several boreholes drilled in the Mesozoic deposits of Istria Depression (Black See shelf) allowed the characterization of intersected Cretaceous successions. Berriasian - Valanginian deposits are terrigenous, represented mainly by sandstones in the lower parts, and clays above. It is impossible to document the presence of Hauterivian-Aptian deposits in the succession. The Albian deposits are still terrigenous (predominantly clays, sometimes with sponge spicules). The Cenomanian transgressive deposits are coarser, and contain Conicorbitolina conica (d’Archiac), Rotalipora cushmani (Morrow) and Hedbergella-Praeglobotruncana sp. The following Turonian?-Campanian-Maastrictian deposits are micritic limestones with planctonic foraminifera in specific successions: Globotruncana cf. elevata (Brotzen), Globotruncana bulloides (Vogler), Globotruncana arca (Cushman), Globotruncana contusa (Cushman), Gansserina sp. For these specific successions the assemblage indicates a Campanian-Maastrictian age. The age of the most underlying deposits could be estimated only by comparisons with published data (Băncilă et al., 1997).
Tertiș, Larisa; Bucur, Ioan I.; Săsăran, Emanoil; and Ghergari, Lucreția
New remarks on the lithology and biostratigraphy of the Cretaceous deposits from Istria Depression (Black Sea shelf),
Studia UBB Geologia
Available at: http://scholarcommons.usf.edu/geologia/vol47/iss2/art10