The Fossil Distribution of Coccolithophore Genus Gephyrocapsa Kamptner and Related Plio-Pleistocene Chronostratigraphic Problems

Reports the study by light microscope of the distributions of the Gephyrocapsa complex in sections from widely separated oceanic areas and from the Mediterranean region. Even using an informal non-Linnaean taxonomic approach based on size, substantial successive morphologic changes could be traced, which allow correlations to be made between Mediterranean reference sections and oceanic records. On the basis of the Gephyrocapsa evolution, I assigned approximate ages to the Mediterranean lower Pleistocene marine stages: Santernian, l.6-l.7 to l.3 Ma; Emilian, l.3-l.2 Ma. The Sicilian base is at about l.l-l.2 Ma, whereas the top has not yet been defined; it should occur, however, shortly after the end of the Jaramillo.