Introduction

Italy is one of the primary sources of data for the Pliocene and Pleistocene. The Italian coastal margins were affected by tectonism during the Pleistocene more than any other part of western Europe, and as a result the Upper Cenozoic marine sequences that crop out along the coast in Sicily and in the mainland Apennine foothills (Figure 11.1) have been the subjects of classic studies on the chronostratigraphy of that age. Additionally, Plio–Pleistocene strata with stratigraphic thicknesses exceeding 8,000 m have been sampled in boreholes in the subsurface of the central Po Valley. Finally, Pliocene and Lower Pleistocene nonmarine strata are common in the montane basins of the Italian peninsula.

Since the very beginning of stratigraphy as a science, the abundance of Cenozoic fossils, particularly in the marine record, has attracted attention to the Italian sections. Lyell's original designations of the “older” and “younger” Pliocene (Lyell, 1833), the latter of which became the Pleistocene, relied heavily on the malacofaunas of the northern Apennines. For the same reason, all standard Pliocene and Pleistocene marine chronostratigraphic terms used in global correlation are based on the biostratigraphy of the Italian sequences. In recognition of this historical importance, the XVIII International Geological Congress in London in 1948 confirmed a general consensus that the Pliocene–Pleistocene boundary should be defined in the exposed Italian marine strata.

In this chapter we shall review the stratigraphic data available from the marine and continental records of Italy, as background for defining the Pliocene–Pleistocene boundary.