The presence of an Antarctic species at 112 mbsf indicates an influence of cooler water masses. As at Site 1085, the upper Pliocene sediment contains an interval with a mixed assemblage rich in T. antarctica that is composed of Southern Ocean species and warm oceanic species, with an approximate age of 1.9-2.8 Ma. Dinoflagellate cysts are common below 213 mbsf and between 262 and 338 mbsf. APC cores experienced a significant coring-induced remagnetization with a radial inward direction. The correlation of features present in the physical properties measurements of adjacent holes was used to demonstrate the completeness of the stratigraphic sequence between 0 and 214 mcd.
Sediments are carbonate rich and organic carbon poor.
Interstitial water chemistry is dominantly controlled by the high carbonate and low organic carbon concentrations in the sediment, which results in modest variations in the chemical gradients of many dissolved species. Alkalinity rises to a broad maximum of approximately 30 mM between 60 and 126 mbsf and subsequently decreases downhole. Sulfate is not completely consumed until 60 mbsf. Carbonate and phosphate precipitation reactions throughout the sequence are also inferred from the profiles of dissolved calcium, magnesium, and phosphate. Among the three Cape Basin sites, Site 1087 is most similar to Site 1085 in its geochemical profiles.