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The Quaternary benthic foraminifers from Leg 95 Sites 612 and 613 were examined with respect to paleoceanographic trends. Data from the two sites indicate the presence of markedly different bottom-water masses, during both glacial and interglacial periods. The dominant interglacial species at Site 612 is Uvigerinct peregrina, which is barely present in corresponding intervals at Site 613. Dominant glacial species are Elphidium excavatum and Cassidulina reniforme at Site 612 and Epistominella takayanagii at Site 613. INTRODUCTION The Baltimore Canyon trough is the most intensively investigated sedimentary basin along the U.S. Atlantic margin. Offshore studies began in the 1950s (e.g., Drake et al., 1959) and have intensified as interest built because of offshore petroleum leases. On the basis of an extensive published record of both geological and geophysical investigations, the New Jersey margin was selected as the most suitable location for constructing the first marginwide stratigraphic transect. Leg 93 started the current phase of drilling on the New Jersey transect, at two shallow sites (604 and 605) on the upper rise and one at the extreme oceanward end of the transect (603). The Leg 95 holes reported on here (612 and 613) provide the link between the shelf and the rise. The advent of the hydraulic piston corer (HPC) has made it possible to obtain from the soft, unconsolidated Quaternary deposits high-resolution results not previously possible with rotary drilling. This chapter focuses on the benthic foraminiferal record of the Pleistocene sections at Sites 612 (1404 m water depth) and 613 (2323 m water depth). At Site 612 this includes the upper 56 m of sediment; at Site 613 the Pleistocene appears to be 187 m thick. Site 613 was cored discontinuously, and approximately 120 m of section was not sampled. Data will be available, however, from nearby Site 604 (Moulotte and Blanc-Vernet, in press), which was cored continuously through the entire Pleistocene section. The purpose of this investigation is to report on Quaternary benthic foraminiferal occurrences at Sites 612 and 613, using the assemblage characteristics to reconstruct the paleoceanography. PREVIOUS WORK There have been several investigations of modern faunas in this area, but most concentrated on the continen1 Poag, C. W., Watts, A. B., et al., Mt. Repts. DSDP, 95: Washington (U.S. Govt. Printing Office). 2 Address: Centre for Marine Geology, Dalhousie University, Halifax, Nova Scotia B3H 3J5 Canada. tal shelf rather than the slope. Cushman (1918-1931), in his studies of the Atlantic, included localities near this area but did not include quantitative data. The first and most comprehensive of the early quantitative studies was that by Parker (1948), who investigated four transects off the New England coast, covering water depths of 15 to 700 m. Later studies (Murray, 1969; Gervirtz et al., 1971; Kafescioglu, 1975) employed more statistical techniques but lacked the coverage of Parker's study. More recently, Poag et al. (1980) did a comprehensive study on the shelf and upper slope off New Jersey. Phleger (1942) examined many cores over a wide range of water depths in the same area, and his data provide a comparative base for the Holocene/Pleistocene boundary in our material. Miller and Lohmann (1982) examined the New Jersey slope environment specifically, identifying Uvigerina peregrina as the dominant species between 1500 and 2400 m, which agrees fairly well with what we observed at the surface of our Leg 95 sites. However, their use of a large sieve size severely limits comparison with data presented here. Streeter (1973) and Schnitker (1974, 1979) examined parts of this area in connection with much wider-ranging studies. METHODS Ten-cm samples were processed for study of benthic foraminifers. All material was stored in a cold room before processing. Sediment was wet-sieved through a 63-μm (#230 mesh) screen. After sieving, the samples were dried and, since most had excess amounts of fine sand, the sediment was sprinkled into carbon tetrachloride to float off the foraminifers. Foraminifers were split into fractions containing 300 to 500 individuals for quantitative counts. Planktonic foraminiferal and oxygen-isotope studies on the planktonic foraminifers are in progress (D. Smith, personal communication, 1985). A total of 72 samples from Site 612 and 50 from Site 613 were studied. Samples were obtained at larger intervals from Hole 613, both because the Quaternary section was longer and because, since it was incomplete, high-resolution samples were of less interest. A total of 115 species were found in samples from Site 612 (Fig. 1, Table 1) and 92 species were found in samples from Site 613 (Fig. 2, Table 2). Data are reported in both absolute abundance (total numbers per 10 cm) and relative frequency. All depths given in the following sections are sub-bottom depths.

Quaternary Benthic Foraminifers from Deep Sea Drilling Project Sites 612 and 613, Leg 95, New Jersey Transect