Micropaleontological record in the Pliocene of Genoa-Arenzano area

This paper aims to analyze microfossil assemblages (diatoms, calcareous nannofossils and foraminifers) found in scattered Pliocene outcrops referred to the Argille di Ortovero Formation. The studied samples were collected in two different areas of the Genoa Province (Arenzano and Genoa town-centre) both from geoengineering boreholes and from digs for building foundations. Biostratigraphically representative species of the different assemblages were recognized; statistic morphofunctional and quantitative analyses were furthermore carried out on benthic and planktic taxa respectively, providing useful data on palaeoenvironmental and palaeoclimatic conditions. The integrated biostratigraphic study allowed to recognize the following Zones: Thalassiosira convexa Zone (subzone C), MNN12 (Amaurolithus tricornicolatus Zone), MPL1 (Sphaeroidinellopsis seminulina Zone, post-acme). The presence of Globorotalia margaritae (MPL2) is furthermore reported from other sections in the same areas. The present work is part of a more general research on the Pliocene of the western Liguria.