The paleomagnetic results from the Hole 1001A K/T boundary interval are good, and drilling overprints appear to be removed by AF demagnetization in fields of 40.0-80.0 mT. However, the declination data show changes of <180° (120°-140°) at the polarity transitions. This observation may either reflect orientation problems in the rotary cores, or incomplete removal of a radial drilling overprint (Sigurdsson et al., 1997). The radial overprint tends to decrease the amplitude of declination variations. Comparison of sedimentation rates above and below the boundary indicates that higher rates were found above the boundary in Hole 1001A. In contrast, a previous study of Deep Sea Drilling Project (DSDP) Site 528 in the South Atlantic (D'Hondt et al., 1996) showed that higher sedimentation rates were found below the K/T boundary (Table 1). Additional studies are planned to examine these contrasting results.
The recurring rock-magnetic features observed in Hole 1002C are interpreted as paleoredox boundaries that mark major transitions between glacial and interglacial sediments. The presence of abundant high-coercivity magnetic oxides (hematite/goethite) may be indicative of the transition from oxic conditions during glacial intervals to anoxic conditions during interglacials that occurred in the Cariaco Basin (Peterson et al., 1991).