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doi:10.2204/iodp.proc.341.202.2017

Results

Table T2 summarizes the effective stress and estimated porosity and permeability at each consolidation step as well as the grain size distribution for each sample. Table T3 summarizes the biogenic silica results. Tables T4 and T5 present the area of the basal peaks used to estimate the normalization factors and the calculated normalization factors, respectively. With the exception of the sample from Section 341-U1417D-43X-3, clay mineral abundance exceeded that of quartz, feldspar, and calcite in all samples (Table T6) . Smectite content ranged from 3 to 38 wt% in Site U1417 samples and from 0 to 3 wt% in Site U1418 samples (Table T7).

Results are shown on Figures F4 and F5 for Sites U1417 and U1418, respectively. At Site U1417, permeability and silica content show similar variations with depth, with the highest values at 474.8 meters below seafloor. Porosity also shows higher values in this depth range, although results are greatly affected by scatter. Additional samples would be needed to distinguish interrelationships between these properties. Relative to Site U1417, Site U1418 shows much less variation in porosity, permeability, and biogenic silica content (Fig. F5).

Measured vertical permeability varied from 1.8 × 10^–18 to 1.5 × 10^–16 m². Except for the sample from Section 341-U1417D-43X-3, which contained predominantly silt-size particles, all samples were dominated by clay-size particles. Sand-size particles ranged between 0 and 27 wt%.

Surveyor Fan sediments are represented by the uppermost sample of Site U1417 and the samples of Site U1418, showing low biogenic silica content (~2 wt%) and low smectite content (≤3 wt%). The preSurveyor Fan sediments (i.e., the lower four samples from Site U1417) have 2–15 wt% biogenic silica and 9–38 wt% smectite in the bulk sample.

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