Site 1007 is situated at 24°30.261´N, 79°19.34´W, at a water depth of 647 m on the toe-of-slope of the western Great Bahama Bank (Fig. 1). Site 1007 was positioned distal of progradational sequences and at the critical point of thinning clinoforms. Seismic refraction surveys (Eberli and Ginsburg, 1987; Eberli, Swart, Malone, et al., 1997) show sequences of thinning clinoforms both westward from the bank and eastward from the basin. The sequences at the site are composed of both drift sediment and neritic carbonate grains derived from the bank (Eberli, Swart, Malone, et al., 1997). Packages of sequences are expected at both the basinal and proximal slope sites at this position. Changes in these packages could possibly reflect the oceanic conditions of the slope of the Great Bahama Bank. Regarding oceanic conditions, the main objectives of this study were to determine the changes of sediments and their lithofacies in order to estimate accurate dates for points marking alterations in oceanic condition. Microfossils with good preservation were better observed at this site than at the proximal Sites 1005, 1004, and 1003.
Rock magnetic measurements were carried out and used as a tool for signaling the anticipated oceanic changes. They provide information about the variability of concentration, grain size, and composition of magnetic minerals within the sediment (e.g., Bloemendal et al., 1988; Thompson and Oldfield, 1986). Variations in magnetic remanence are in some cases strongly correlated with oxygen isotopic composition and CaCO3 content of deep-sea cores (e.g., Kent, 1982; Bloemendal and de Menocal, 1989). The species, grain size, and concentration of magnetic minerals in the sediment on the toe-of-slope of the western Great Bahama Bank are discussed in this chapter.