The samples represented depths ranging from 11 to 400 meters below seafloor from both the open-ocean and ocean-margin subsurface environments. Table T1 summarizes the measured permeability data for each sample and the corresponding effective stress and porosity at each consolidation step. We applied four to five flow rates to each sample during the testing procedure to evaluate the repeatability of the measured permeabilities. The statistical errors for measured permeabilities have been quantified in terms of standard deviation as tabulated in Table T1. Our results indicate that the repeatability of permeability measurements is good. Permeabilities were measured at varying effective stress values ranging from 0.14 to 0.55 MPa. In general, permeabilities decreased with increasing effective stress (Fig. F4).
The measured permeabilities vary from ~8 x 10–19 m2 to ~1 x 10–16 m2. The lower permeabilities represent the lithified oozes and clay-rich sediments, whereas the higher permeabilities represent the unlithified oozes and silt-rich sediments. Site 1231 yielded the widest range of permeability values, varying from 1 x 10–16 m2, representing carbonate-rich sediments deposited above the carbonate compensation depth (CCD), to 3 x 10–18 m2, representing clay-rich sediments deposited below the CCD.