Despite the key location of eastern New Zealand at the gateway for major water flows into the Pacific Ocean, no previous ODP drilling has been accomplished in the region. Of the four earlier DSDP sites (Fig. 2), only one–Site 594 in the inner Bounty Trough, which penetrated a thick sequence of hemipelagic muds and nannofossil chalks dated to the late Early Miocene–was cored with the Advanced Piston Corer. Results from this site yielded important information regarding the synchroneity of glaciations between the hemispheres (Nelson et al., 1985), the history of supply of AAIW, and the position through time of the Subtropical Convergence (STC) and the SAF (Nelson et al., 1986, 1993). The three other DSDP sites were Sites 275 and 276, which were rotary drilled at locations on the edge of the Campbell Plateau where active erosion has removed a large part of the record, and Site 277, on the western edge of the Campbell Plateau, where an exceptional Paleogene–Neogene isotope record was recovered (Shackleton and Kennett, 1975). New research into the late Quaternary oceanographic, climatic, and sedimentary history of offshore eastern New Zealand has burgeoned over the last two decades (e.g., Carter and Mitchell, 1987; Barnes, 1992; Fenner et al., 1992; Carter et al., 1994; Carter and McCave, 1994, 1997; L. Carter et al., 1995, 1996; R. Carter et al., 1996; McCave and Carter, 1997; Thiede et al., 1997; Weaver et al., 1997, 1998. This work notwithstanding, the lack of cored offshore drill holes means that we remain ignorant of the post-mid-Cenozoic paleoceanography for most of the region, apart from occasional studies from the western shallow water and onland edge of the basin (Ward and Lewis, 1975; Carter, 1985; L. Carter et al., 1996; R. Carter et al., 1996). Recent seismic studies have delineated the offshore structure moderately well (Lewis et al., 1985; Barnes, 1994; R. Carter et al., 1994, 1996; Lewis, 1994; Barnes and de Lepinay, 1997), and this is the region that we must now search for the record of the inception and evolution of the large ACC and the Pacific DWBC current systems.

To 181 Background and Objectives

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