Data report: permeability, consolidation, stress state, and pore system characteristics of sediments from Sites C0011, C0012, and C0018 of the Nankai Trough

Abstract

We performed uniaxial, constant-rate-of-strain consolidation experiments; grain size analyses; specific surface measurements; and mercury injection capillary pressure (MICP) measurements to characterize transport and deformation properties of 30 specimens from Integrated Ocean Drilling Program Expedition 333 Sites C0011, C0012, and C0018. Permeability, compression index, and overconsolidation ratio were determined from consolidation experiments. Permeability values range from 2.3 × 10 –14 m 2 to 5.9 × 10 –19 m 2 and generally decrease with increasing depth. Compression indexes, which define stress-strain behavior during consolidation, range from 0.26 to 2.7. Overconsolidation ratios, defined as the ratio of the preconsolidation stress to the in situ vertical effective stress under hydrostatic conditions, range from 0.20 to 4.1 and generally decrease with increasing depth. Median grain sizes determined by Stokes settling analysis range from 1.10 to 15.4 µm, and samples consist mainly of silt- and clay-sized particles. Specific surface values determined by methylene blue adsorption range from 25.7 to 77.7 m 2 /g. MICP measurements on a subset of 14 samples yield median pore throat radii of 0.087 to 0.36 µm and air-water capillary entry pressure values of 64 to 770 kPa.