Abstract We review here data and information on Antarctic volcanism resulting from recent tephrostratigraphic investigations on marine cores. Records include deep drill cores recovered during oceanographic expeditions: DSDP, ODP and IODP drill cores recovered during ice-based and land-based international cooperative drilling programmes DVDP 15, MSSTS-1, CIROS-1 and CIROS-2, DVDP 15, CRP-1, CRP-2/2A and CRP-3, ANDRILL-MIS and ANDRILL-SMS, and shallow gravity and piston cores recovered in the Antarctic and sub-Antarctic oceans. We report on the identification of visible volcaniclastic horizons and, in particular, of primary tephra within the marine sequences. Where available, the results of analyses carried out on these products are presented. The volcanic material identified differs in its nature, composition and emplacement mechanisms. It was derived from different sources on the Antarctic continent and was emplaced over a wide time span. Marine sediments contain a more complete record of the explosive activity from Antarctic volcanoes and are complementary to those obtained by land-based studies. This record provides important information for volcanological reconstructions including approximate intensities and magnitudes of eruptions, and their duration, age and recurrence, as well as their eruptive dynamics. In addition, characterized tephra layers represent an invaluable chronological tool essential in establishing correlations between different archives and in synchronizing climate records.

Patterns of diversification and longevity in Paleogene coccolithophorids are analyzed by combining the temporal history of selected genera, families, and orders with the number of discrete morphospecies in them. The coccolithophorids underwent an abrupt mass extinction at the Cretaceous/Paleogene boundary, and a rapid (~1 m.y.-long) global turnover at the Paleocene/Eocene boundary. In contrast, they underwent a diachronous turnover at the Eocene/Oligocene boundary that spread over 6–7 m.y. at mid- and low-latitudes. The turnover included sequential extinctions and speciations of short-lived taxa, beginning slightly before 37 Ma, and losses of taxa that dominated mid- and low latitudes at 34.2 Ma and high latitudes at 32.3 Ma. It is also marked by a few evolutionary appearances, in particular, that of the Family Syracosphaeraceae, which is the most diversified of the living coccolithophorids. Most importantly, the turnover resulted in a shift in the balance between families across several orders, such that families that dominated during the Eocene dwindled during the turnover, and, conversely, families that were little diversified during the Eocene became dominant. Thus, members of Family Coccolithaceae and the genus Heliodiscoaster typify Eocene communities; members of the Family Calcidiscaceae and the genus Eudiscoaster characterize Neogene communities. This shift was accompanied by a decrease in the robustness of coccoliths, suggesting that the Eocene/Oligocene event had a marked effect on the physiology of Eocene coccolithophorids. Bolide impacts and the emplacement of large basaltic provinces provide mechanisms to explain large biotic events. Such mechanisms, however, can be ruled out in the case of the Eocene/Oligocene turnover, which was undoubtedly related to climatic cooling and glaciation. The filtering effect of environmental stress on late Eocene diversity remains to be explained.