varies from
8.5° to 17.5°C.
The variation
implies that Core 167-1016C-1H covers oxygen isotope Stages 1-6, with an average
linear sedimentation rate of 6.4 cm/k.y.TOC and CaCO3 contents were determined for 304 samples, and biomarkers were analyzed for 101 samples from Core 167-1016C-1H.
Paleotemperature estimated
from varies from
8.5° to 17.5°C.
The variation
implies that Core 167-1016C-1H covers oxygen isotope Stages 1-6, with an average
linear sedimentation rate of 6.4 cm/k.y.
The responses of marine ecosystem to glacial-interglacial climate changes are evident in the variations of TOC, CaCO3, and biomarker concentrations. Peaks of diatom-derived C25:1 HBI alkene concentrations occur during warming intervals, suggesting intensified upwelling during deglaciation. The concentrations of haptophyte-derived alkenones and diatom-derived C25:1 HBI alkene vary out of phase, which presumably resulted from the changes in the mode of nutrient supply to surface mixed layer, such as the changes of the intensity, seasonality, frequency, or duration of upwelling.
Maximal CaCO3 contents (>10%) were observed in both warming and cooling intervals. The peak in cooling interval relates to an alkenone maximum, whereas the peaks in warming intervals do not. This implies that carbonate production is not the only factor controlling CCD at this site and suggests considering the importance of changes of North Pacific deep-water chemistry.
Petroleum-type compounds are present in Site 1016 sediments, indicating that their occurrence is not restricted to coastal sediments, but extends to hemipelagic deep-sea sediments. The concentrations of petroleum-type compounds maximize in the warming intervals that correspond to the timing of destruction of a huge tar mound off Point Conception. They were presumably transported by the Arguello Fan system to Site 1016.
