Unit II is subdivided into two subunits based on the mineralogy. Several intervals of characteristically bluish green nannofossil clay occur, which contain large amounts of pyrite as nodular irregular layers or as finely disseminated particles within the sediment. Subunit IIB continuously grades down into the green nannofossil clay of Unit III at 553.02 mcd, marked by a progressive change in the sediment color from brownish gray to a distinct greenish gray. Unit III is characterized by relatively high concentrations of smectite and illite. However, the bulk mineralogy suggests that either a change in the source of the terrigenous material or a change in the weathering regime of the source region took place over time.
Planktonic foraminifers are abundant and have good preservation for the site's entire interval.
Benthic foraminifers are generally few but become more abundant in the lower part. However, we found no clear evidence for reworked benthic foraminifers from the shelf and upper slope. The biohorizons from the 3 fossil groups generally agree with each other. Additional swings of the declination are present further downcore, but their identification to a known polarity chron is made difficult by the large overprint which is present on inclination data, even after demagnetization at 20 mT. A transition from reverse declinations to normal occurs between 160.5 to 165.8 mcd possibly marking the Olduvai. Based on the age-depth model from 64 biostratigraphic and magnetostratigraphic datums, and the dry density and carbonate concentration records, we calculated total and carbonate accumulation rates.