Integrated biostratigraphy across the Eocene/Oligocene boundary at Noroña, Cuba, and the question of the extinction of orthophragminids

Integrated biostratigraphy by means of planktic foraminifera, calcareous nannofossils and larger benthic foraminifera from a continuous marine section at Noroña (Cuba) suggests that the extinction of orthophragminids lies in the Rupelian (early Oligocene). Three levels containing larger benthic foraminifera are found in the lower and middle part of the planktic foraminiferal Zone O1(P18) and in the middle part of the calcareous nannofossil Zone NP21(CP16) (Rupelian). Furthermore, a traditional larger foraminifera Eocene marker, Fallotella cookei, is abundant in the Oligocene at the Noroña section, consistent with data reported from lower Oligocene sediments from Cuba, Florida and Jamaica. In order to solve the question of the orthophragminid extinction, which has been shown in some places to coincide with the Eocene/Oligocene boundary, data from the Noroña section are discussed in the view of the presence of these larger benthic foraminifera in lower Oligocene strata in other sections world wide. Our data from Noroña, as well as those from other previously studied sections, suggest that the extinction of the orthophragminids could be diachronous, with disappearances near the Eocene/Oligocene boundary in the low latitudes of the Indo-Pacific region (e. g., Tanzania) as opposed to the Rupelian in the low latitudes of the Caribbean-American bioprovince (e. g. Cuba and Jamaica) and in the middle latitudes of the Tethys (e. g., Italy and Spain).