ODP Sites 703 and 704 were drilled near the crest of the Meteor Rise in the southeastern part of the South Atlantic in order to explore the role of this aseismic rise as a barrier to the flow of deep water between the Antarctic and South Atlantic during the early evolution of the South Atlantic and to investigate the subsequent subsidence and paleoceanographic evolution of this area. A combination of shipboard whole-core paleomagnetic determinations on all archive core halves and post-cruise paleomagnetic analyses of some 440 discrete samples from the two sites has allowed definition of the sequence of geomagnetic polarity reversals that occurred during deposition of much of this sedimentary sequence. The magnetostratigraphic record for Sift 703 extends from the middle Eocene to the early Miocene and that for Site 704 from the early Miocene to the Pleistocene. The correlation of this record to the standard geomagnetic polarity time scale of Berggren et al. (1985) is generally good for the Oligocene and late Miocene to Pleistocene, but is poorer for the early and middle Miocene. The combined magnetostratigraphic record for these two sites will facilitate the development and chronometric calibration of refined high-latitude biostratigraphic zonations. Furthermore, it provides an important basis for defining the periodicity of the late Neogene stable isotope and carbonate fluctuations observed in these cores and relating these changes to the paleoclimatic and paleoceanographic driving forces.
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