Reworking is limited to the interval between 60 and 100 mbsf. The overall abundance of benthic foraminifers is high throughout the studied interval. The planktonic to benthic foraminifer ratio at this site is about ten times higher than at previous sites. Radiolarians are generally rare and show signs of dissolution in almost all samples. The presence of an Antarctic species indicates an occasional influence of cooler currents.
Diatoms are rare or absent in most of the section.
Interstitial water chemistry is dominantly controlled by the low organic carbon and high carbonate concentrations in the sediment, which result in modest variations in the chemical gradients of many dissolved species. Alkalinity rises to a broad maximum of approximately 30 mM between 46 and 84 mbsf and subsequently decreases to the bottom of the hole. Sulfate is not completely consumed until 65 mbsf, which is also deep in comparison to previous Leg 175 sites. Carbonate and phosphate precipitation reactions throughout the sequence are also inferred from the profiles of dissolved calcium, magnesium, and phosphate. Hole 1085A was logged with a full suite of sensors to continuously characterize the sedimentary changes through depth and to provide data for core-log integration.