Linear sedimentation rate (LSR) and mass accumulation rate (MAR) are calculated based on FO and LO (last occurrence) of biostratigraphically important nannofossils. Key nannofossil datums and absolute ages (Berggren et al., 1995) used to determine LSR and MAR are listed in Figure F3. MAR is calculated after Van Andel, et al. (1975) and uses average values for wet bulk density and porosity. MAR was calculated using the following equation:
where BD = wet bulk density (in grams per cubic centimeter), P = porosity (in weight percent), WD = seawater density (WD = 1.025 g/cm3), and T is the thickness of sediment that accumulated over time t (t = 106 yr). Limited numbers of measurements are available from multisensor track data taken by the Shipboard Scientific Parties of Legs 173 (1998a, 1998b, 1998c), 149 (1994), and 47B (Williams and Mountain, 1979) and can be found in the appropriate chapters of each Initial Reports volume.