Twenty-eight samples were selected for dinoflagellate cyst analysis. The samples were taken from the Neogene and Quaternary of Holes 1095B, 1096B, and 1096C on the continental rise west of the Antarctic Peninsula (Fig. F1). Lithologies are mainly diatom-bearing silty clays and diatom silty clays, with muddy diatom oozes in the lower Pliocene and barren claystone at the base of Hole 1095B (Table T1) (Barker, Camerlenghi, Acton et al., 1999). Biogenic silica (in the form of diatoms, radiolarians, and rare silicoflagellates) was measured by point counting a smear slide made from each sample. The more expanded sequence at Site 1096 was sampled down to 513 meters below seafloor (mbsf) (~4.2 Ma), and Site 1095 was sampled from 122 mbsf (~4.2 Ma) to the base of the hole, which dates ~10 Ma. Lithologic cyclicity is evident in many of the sedimentary sequences, with fine-grained laminated sediments alternating with bioturbated, sandier lithologies on a scale of decimeters to meters. Several pairs of dinoflagellate samples were taken from these alternating lithologies. Sample depths were converted to age using the paleomagnetic timescale provided in Barker, Camerlenghi, Acton et al. (1999; tables T38, T34), with linear interpolation between magnetic reversal datum points.
All the samples were prepared using the standard palynological preparation technique as outlined by Wood et al. (1996), except for the use of oxidizing reagents, which were avoided to prevent the loss of the protoperidiniacean dinoflagellate cysts (Dale, 1976). The samples were treated qualitatively, as the numbers of cysts recovered were low, and indeed, some of the samples proved to be entirely barren of cysts. The sample residues were stained with Safranin, made up onto strewn slides, and examined at 10× using a Zeiss Axiolab microscope.