Introduction

It is now more than 150 years since geologists became convinced that Scandinavian and Alpine glaciers had once extended far beyond their present limits, and more than 80 years since the same situation was recognized in the Antarctic. These observations lead to the realization that in the recent geologic past, ice, now mainly associated with the polar regions, had been much more widespread, and was, in fact, responsible for the formation and shaping of many features of the now ice-free landscape in the higher latitudes of Europe and North America, as well as parts of southern South America and New Zealand [see historical summary in Flint, 1971] Indeed, the dominant climatic event of the late Cenozoic was the Ice Age, during which most areas of the Earth’s surface within 30° of the poles were repeatedly covered by ice sheets, by grounded or floating glacier ice, or at least under the influence of sea ice (Fig. 1). Though most apparent at high latitudes where the morphology of both the land and the continental shelves is dominantly shaped by glacial erosion and deposition, the impact of the late Cenozoic glaciations can be recognized, and is still being felt, worldwide, in the effects of changes in sea level, the distribution patterns of vegetation and related animal species, the distribution of marine plankton, and in other ways. Furthermore, formations in the stratigraphic record extending back into the Precambrian have also been attributed to ancient ice ages [Hambrey and Harland, 1981; Anderson, 1983]. Thus, glaciation and its effects, rather than being unique phenomena confined to the polar regions, are of considerable global geologic and socio-economic significance.