| Summary: | Drilling Sites 270, 272, and 271 of the Deep Sea Drilling Project, (DSDP) were intended to sample a thick continuous sequence of sediments in the Ross Sea. This objective was not achieved due to the fact that the requisite depths were not reached. Diatom assemblages from DSDP Sites 270 and 272 are used to determine the temporal relationship between these holes. Diatoms reported here from Site 270, represent the first pre-Pleistocene diatoms recovered at this locality. Ages and diatom zonations of earlier studies of these sites are confirmed, although some revisions are made. A maximum age for the lower most portion of hole 272 is determined at 17.5 m.y., 1,7 m.y. younger than what had been previously accepted. A minimum age of 20.7 m.y. for the top of hole 270 is proposed here, which agrees with the ages derived from the foraminiferal studies of Leckie and Webb (1983). A 3.5 m.y. gap separates the sections cored in Sites 270 and 272, as indicated by the Early - Middle Neogene diatom zonations of Weaver and Gombos (1981) and Harwood (in press) used in this study. This unsampled interval represents a significant data gap in the Early Neogene sedimentary record of this region. No embargo
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