Distribution of Foraminiferal Indicator Groups and the Upper Tortonian–Lower Messinian (Miocene) Stratigraphy in the Gibliscemi Section, Sicily, Italy

Abstract

Planktonic and benthic foraminiferal assemblages from the upper Tortonian-lower Messinian part of the Gibliscemi section (Sicily, Italy), are described. The major stratigraphic markers recorded in the section are (1) the first occurrence of Globigerinoides extremus marking the lower boundary of the corresponding upper Tortonian zone, (2) first occurrence of Globorotalia miotumida that previously was considered as an index form of the Tortonian–Messinian boundary, and (3) the first regular occurrence of Globorotalia conomiozea recording this boundary. The distribution in the section of keeled Globorotalia and Globorotalia miotumida group is traced. The composition of the Globorotalia scitula group is analyzed and the group is proposed to be identified as one species G. praescitula. It is assumed that the Mediterranean in the Middle and Late Miocene was the site where Globigerinoides ruber survived during its complete disappearance in the Atlantic and Pacific.