Introduction

The lithostratigraphy, biostratigraphy, and chronostratigraphy of Plio–Pleistocene deposits of The Netherlands can be related to paleoclimatic evidence for recognizing the Pliocene–Pleistocene boundary in this area. Such data have contributed to correlation between the stratigraphic sequence in The Netherlands and the proposed Neogene–Quaternary boundary-stratotype in the Vrica section of Calabria, Italy.

The Plio–Pleistocene sequences of strata in The Netherlands are apparently the most nearly complete within the southern North Sea basin, as they were deposited in an area of persistent strong subsidence. Moreover, interfingering of marine and nonmarine beds is common in this region.

The marine deposits contain microfauna that derived mostly from rather shallow water, with planktonic foraminifera being virtually absent, thus preventing direct correlations with the Mediterranean region or deep-sea sediments. The mollusk faunas are likewise quite different from those encountered in more southern regions of Europe. Mammal remains characteristic of the Villafranchian have been reported from some of the marine beds, especially from those of East Anglia, but again, those discoveries do not permit precise correlation with the Mediterranean area.

From about the middle part of the Pliocene strata upward, the marine faunas in the North Sea basin show reductions in the number of species, but increases in the numbers of cold-water specimens. During that time, periodic immigrations of boreal–arctic mollusks that today do not occur in the southern North Sea basin played an important role. The continental sequences, however, have provided the most detailed paleoclimatic and paleomagnetic information, which has led to a better understanding of the changes in the marine environment and to better correlations with the Mediterranean realm.