Below 842 mbsf, laminae with calcite cement are present and sections of the core become increasingly cemented with likely authigenic carbonates. A change to darker-color claystones occurs at 894 mbsf, where fracture patterns also become curved. Neogene high- latitude zonal schemes for both diatoms and radiolarians yielded identification of 21 diatom and 12 radiolarian biostratigraphic datums between 0 and 600 mbsf. Below 600 mbsf, age assignments are inferred from calcareous nannofossils, which are present in only a few discrete intervals with moderate to good preservation of assemblages that have low diversity. Nannofossils yield Pleistocene to lowermost Miocene ages.
Benthic foraminifers are more common than planktonics, which are rare.
The foraminifers indicate several intervals of redeposited material. The uncertainty in ages is larger below 600 mbsf, where only few biostratigraphic ages exist to constrain the paleomagnetic reversal stratigraphy. The interstitial water profiles document downhole sediment diagenesis at Site 1165. Concentrations of dissolved silica increase from 522 M at the seafloor to a maximum of 1000 M at 200 mbsf and reflect the dissolution of abundant siliceous microfossils. Silica values decrease from 400 to 999 mbsf.