A large unconformity is identified by an erosional contact at 450 mbsf and by biostratigraphic evidence. Below the erosional contact are fine laminations that are microfolded with sharp upper and lower contacts. Pyrite is present as silt-sized aggregates of euhedral crystals or as framboids. A preliminary biostratigraphy was developed using calcareous nannofossils and planktonic foraminifers. The biogenic component of both lithostratigraphic units consists of abundant to very abundant nannofossils.
Foraminifers are abundant to few.
Siliceous spicules, dinoflagellate cysts, and radiolarian tests are present in trace abundances only in the upper Pliocene and Pleistocene sediments. Radiolarian species indicate generally low productivity under subtropical warm-water conditions. The radiolarian assemblages that are characterized by common Cycladophora davisiana suggest upwelling conditions for samples from 60 to 70 mbsf. 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.