Microfossil occurrence in Pliocene-Quaternary sediments of the North Atlantic

Lowlatitude zonations were used for the subdivision of the Pliocene and Quaternary Sediments of different climatic belts, and certain subglobal zonal units were recognized. Variations in the degree of resolution of the zonation in different latitudes were revealed; the resolution of zonal scales based on calcareous plankton diminishes northwards.

Changes of taxonomic composition of the zonal foraminifer and nannoplankton assemblages within various latitudinal belts of the Atlantic were analyzed taking into consideration the influence of climatic factors and of local bionomic conditions. Correlation with the magnetostratigraphic time-scale permitted the establishment of the most reliable appearance and disappearance datums (datum planes) of planktonic foraminifer and nannoplankton species.