In this study, I counted 100 specimens of D. brouweri and C. pelagicus along random traverses across smear slides made from Holes 1115B and 1115C samples. I included all varieties of "D. brouweri" in the count of D. brouweri s.l. (i.e., D. brouweri ssp. recurvus Cati and Borsetti, D. brouweri var. rutellus Gartner; D. brouweri ssp. bipartitus Haq and Berggren; D. brouweri ssp. brouweri Theodoridus; and D. brouweri ssp. streptus Theodoridus). Species counts for each sample examined are shown in the "Appendix." Results are expressed as the percentage of each species in the total count of 100 D. brouweri and C. pelagicus specimens (Fig. F4). Using two species that vary inversely in relative abundance rather than using the absolute abundance of only one species avoids potential error caused by variations in the density of specimens sedimented on a slide. Siesser and de Kaenel (1999) used a similar method of investigation for the Pliocene in the western Mediterranean, and Wei et al. (1988) used a ratio of these two species on the Galicia Margin.
Samples investigated are plotted against the timescale (Fig. F4) by using selected nannofossil, foraminifer, magnetochron and 40Ar/39Ar datums identified in Holes 1115B and 1115C as tie points (Lackschewitz et al., in press; Resig et al., in press; Takahashi et al., this volume) (Table T1) and interpolating the position of samples between datums (see "Appendix" ) (Fig. F4). I attempted to select samples with an ~0.1-m.y. separation (see "Appendix" ), although this was not always possible, owing to sample availability and differing degrees of preservation among samples.