The median grain size of the extracted terrigenous component ranges from 6.6 to 3.6 µm for the 10 samples collected from Site 215 (Table T1; Fig. F1). As highlighted by Hovan and Rea (1992), we find a general drop in median grain size from upper Paleocene sediment to lower Eocene sediment, although this change is not as great as previously recorded. We note, however, that our samples are not true replicates and do not span the entire depth interval examined by Hovan and Rea (1992). For the nine samples collected within 5 cm (and on average 3 cm) of those analyzed by Hovan and Rea (1992), we measured an average difference in grain size of ~0.4 µm (Fig. F1), which is approximately equal to the precision of the instrument for particles of this size.
All five samples analyzed at Site 1267 show a relatively flat grain-size distribution over a broad size range (Fig. F2). The median grain sizes range from 7.6 to 10.1 µm, whereas the modal grain size varies from 6.5 to 11.5 µm (Table T2). The overall shapes of the grain-size patterns are similar to those observed at Site 527 by Rea and Hovan (1995).
In contrast to samples from Site 1267, grain-size distributions for the five samples from Site 1263 show a distinct mode (Fig. F2). Similar to the samples measured at Site 1267, however, Site 1263 samples record a broad grain-size distribution indicative of hemipelagic terrigenous material influence. The median grain sizes range from 5.5 to 6.9 µm, whereas the modal grain size varies from 5.6 to 6.9 µm (Table T2).