New biostratigraphic data on the Monte Soro Flysch (Western Maghrebian Chain, Sicily)

A detailed analysis based on calcareous nannoflora and planktonic foraminifera has been carried out on the Lower Cretaceous Monte Soro Flysch (Sicily, Italy) in order to constrain better the age of this unit and to understand its palaeogeographic implications. This study is part of a biochronostratigraphic review of the maurétaniens Cretaceous flysch of the Betic-Maghrebian Chain which has been underway for some years. The Monte Soro Flysch is subdivided into two members: a clayeycalcareous lower member and a clayey arenaceous upper member. On the basis of the planktonic foraminiferal and calcareous nannofossil content the age of the lower member has been precisely dated as late Hauterivian-early Aptian. Unfortunately, the upper member is barren of fossils. The lower member of the Monte Soro Flysch contains several black shale levels which can be correlated with the early Aptian globally recognized organic-rich layers. The results obtained from our study permit a much more detailed age assignment and confirm the marked bio-chronostratigraphic similarity of the Monte Soro Flysch with the other maurétaniens Cretaceous flysch of the Betic-Maghrebian Chain.