A sedimentary section, 570 m thick, extending from the Holocene to the upper Miocene (~10.1 Ma), was recovered at Site 1095. Recovery was essentially continuous to 480 mbsf. Sedimentation rates were determined using magnetostratigraphy from Holes 1095A and 1095B in combination with diatom and radiolarian datums. Sedimentation rates are assumed to be constant between datums and are calculated by taking the slope of the depth-age curve between successive points. In this case, the sedimentation rates were calculated from the depth-age fixes (Fig. F52 ; Tables T38, T39, T40) by fitting linear regression lines to selected intervals of the combined magnetic and biostratigraphic data sets.

The depth of a geomagnetic polarity transition is defined as the depth at which the inclination changes sign. Many transitions were assigned a large uncertainty interval where the transition itself was lost in a gap between cores or within a disturbed interval (see Table T28). The center of the uncertainty interval was used in calculating sedimentation rates. Biostratigraphic datums were assigned when a clear FO or LO could be determined through examination of sediment samples. No FO or LO was determined when the occurrence bordered an interval barren of biogenic material.

Sedimentation rates determined from polarity transitions and diatom and radiolarian datums are given in Tables T38, T39, and T40 and illustrated in Figures F53 and F54. Rates derived from paleomagnetic data show a change from Hole 1095A to 1095B, with a lower sedimentation rate in Hole 1095A over the last 3.04 m.y. The lower sedimentation rate indicates a decrease in sediment deposition between 60 and 83 mbsf. The possibility of a hiatus between 50 and 65 mbsf is discussed in "Paleomagnetism". Seismic stratigraphy suggested an unconformity at ~60 mbsf coincident with a prominent lithostratigraphic boundary (see "Seismic Stratigraphy" and "Lithostratigraphy"). The paleomagnetic and biostratigraphic data are in excellent agreement for the upper 200 m of this section. Below 200 mbsf, the biostratigraphic data bracket the depth-age curve derived from magnetostratigraphy. The combined data sets yield a smooth depth-age profile down to 480 mbsf. This curve is continued down to 551 mbsf in the GHMT logging data and extrapolated to 570 mbsf. The overall trend is an uphole decrease in sedimentation rate from ~11 cm/k.y. near the base of the hole to 2.5 cm/k.y. at the top.