0.65 for hemipelagics and turbidites respectively, and a final porosity based on core
measurements of shipboard porosity (Shipboard Scientific Party, 2001). During phase
two, prism thickening rates for Sites 1174 and 808 were calculated using change in prism
thickness and a convergence rate of 4 cm/yr. The convergence rate was used to calculate
the time needed for the incoming sediments to underthrust to Sites 1174 and 808. In
phase two, each stress step was 50,000 years, and Site 1174 was loaded for 6 stress steps
while Site 808 was loaded for 7 stress steps.
Table 3-3. Summary of sedimentation rates calculated from biostratigraphy at Sites 1173,
1174 and 808 and prism thickening rates calculated from prism geometry and
convergence rate.
Site Unit Thickness Time Vertical loading
(m) (Ma)
Initial Prism
sedimentation rate thickening rate
(m/yr) (m/yr)
1173 Turbidites 120 Present-0.25 5.07 x 10-4
upper Shikoku 220 0.25-2.85 7.42 x 10-5
lower Shikoku 50 2.85-3.75 1.21 x 10-4
Proto-decollement 25 3.75-4.95 4.55 x 10-5
lower Shikoku 290 4.95-14.00 8.08 x 10-5
1174 Turbidites 420 Present-0.30 1.9 x 10
Trench-wedge faces 50 0.3-0.90 1.91 x 10-4
upper Shikoku 190 0.90-2.5 2.61 x 10-4
lower Shikoku 149 2.5-6.25 1.12 x 10-4
Decollement 25 6.25-7.15 7.85 x 10-5
lower Shikoku 256 7.15-14.30 1.20 x 10-4
808 Turbidites 550 Present-0.35 3.6 x 10-3
Trench-wedge faces 75 0.35-0.95 4.28 x 10-4
upper Shikoku 188 0.95-2.85 2.20 x 10-4
lower Shikoku 125 2.85-5.35 1.46 x 10-4
Decollement 25 5.35-6.35 7.30 x 10-5
lower Shikoku 265 6.35-14.35 1.03 x 10-4
Results
Model Results
Results of the base run using the one-dimensional loading and fluid flow model are
summarized in Table 3-4. For the base run, values of ko and (p were assigned according