Ocean Drilling Program (ODP) Site 994 (3147.14'N, 75º32.75'W) is located on the southern flank of Blake Ridge at a water depth of 2798 m. The Blake Ridge is a large drift deposit that extends ~400 km in a southeast direction from the continental rise of the passive margin of the southeastern United States (Fig. 1).
The ridge is topographically expressed as a southeast narrowing tongue of sediment with a crest 1200-2500 m above surrounding abyssal plains (Uchupi, 1968).
Sediment samples studied in this work are Pleistocene (lithostratigraphic Units I and II). The units are characterized by alternating decimeter- to meter-thick interbeds of dark greenish gray nannofossil-rich clay and more carbonate-rich greenish gray nannofossil clay. Distinctive features clearly indicative of contour-current deposition were observed in Units I and II. Evidence for long-distance transport of continental slope sediments by the Western Boundary Undercurrent to Site 994 is clearly provided by the a thin red bed of foraminifer-rich terrigenous mud (Paull, Matsumoto, Wallace, et al., 1996).