(Table 1) Radiolarian abundances and preservation in DSDP Hole 96-618 samples

Radiolarians are present in samples from six of the seven Deep Sea Drilling Project Leg 96 sites examined. The age of the siliceous fauna in these samples ranges from late Pleistocene through Holocene, with some Cretaceous radiolarians redeposited in Pleistocene sequences. Radiolarian preservation is discontinuous at these sites except for intraslope basin Site 618, where the sediments throughout the first five cores contain radiolarians.

(Table 1) Diatom abundance and preservation in ODP Hole 130-806B samples

We report on diatom abundance and preservation stratigraphy in the uppermost four cores of Ocean Drilling Program Hole 806B, which span the Quaternary period. Changes in diatom abundance and preservation show a rather complicated pattern, with much noise at high frequencies. However, in the cycles corresponding to eccentricity and obliquity variations, the picture is quite clear. Abundance and preservation follow glacial-interglacial cycles, with lowest abundances and poorest preservation observed in sediments that correspond to glacial stages. Seventy taxa compose the diatom assemblage of Hole 806B (from Samples 130-806B-1H-1, 8-9 cm, to -4H-7, 73-74 cm) with Azpeitia nodulifera as the dominant member. This species exhibits significant size variations related to glacial and interglacial stages during the Pleistocene. The distribution of power in the Fourier spectrum of the diatom signal (in the time domain) displays the expected Milankovitch frequencies (at 100,41, and 24-18 k.y.). It also shows concentration at various "odd" frequencies, especially at 62 k.y., suggesting a complicated response of productivity (and silicate chemistry) to climatic forcing.