Earth Sciences Department, Turin University, Italy

The subject of this study are assemblages of calcareous nannofossils and foraminifers from the Cessole Marl and the base of the Serravalle Sandstone, which outcrop in the Lemme-Gavi section (Southeastern Piedmont, Northwestern Italy). The deposition of the studied sediments occurred during the Late Langhian, MNN5b Subzone (Sphenolithus heteromorphus Partial-range Zone, MNN5). Planktonic and benthic foraminifers show conditions of open-sea and sedimentation on the slope, specifically in the upper epibathyal zone. Taxa percentage variations suggest a slight and progressive shallowing of the area and a probable increase of paleoenvironmental instability.

Key words: Foraminifers, paleoenvironment, Middle Miocene, Northern Italy.

Se estudian los nanofósiles calcáreos y los foraminíferos de las Margas de Cessole y las areniscas de Serravalle, aflorante en la sección Lemme-Gavi (noroeste de Italia). El depósito tuvo lugar durante el Langhiense superior (Subzona MNN5b de la zona MNN5 de Spenolithus heteromorphus). Las asociaciones de foraminíferos planctónicos y bentónicos permiten inferir un modelo paleoambiental característico del dominio del talud continental y con profundidad decreciente.