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Data report: frictional healing and compressibility of sheared sediment from fault zones, Sites C0004 and C00071

Matt J. Ikari,2, 3 Matthew W. Knuth,4 Chris Marone,2 and Demian M. Saffer2


We conducted shearing tests on samples spanning key fault zones recovered from Integrated Ocean Drilling Program (IODP) Sites C0004 and C0007 from Expedition 316 to the Nankai Trough offshore Japan. Results of slide-hold-slide and normal stress stepping procedures allow quantification of frictional healing, time-dependent compaction, and compressibility of sheared gouge layers. Samples were sheared as thin layers in the double-direct shear configuration at 25°C in a true-triaxial pressure vessel at constant effective normal stress of 25 MPa and pore pressure of 5 MPa using a water-based brine saturated with 3.5 wt% NaCl. We monitored the poromechanical drainage state during shear by holding the pore pressure at the upstream end of the sample at 5 MPa while monitoring the downstream pore pressure. Friction constitutive behavior was determined using slide-hold-slide tests in which hold times ranged from 1 to 1000 s. Frictional healing rates range from ~0.003 to 0.008 per decade, with slightly higher rates measured for samples from Site C0004 than from Site C0007. Both sites exhibit similar compaction rates of ~0.002–0.007 per decade during holds. Both frictional healing and compaction correlate very well with the logarithm of hold time, with R2 > 0.95. For Site C0004 samples, compressibility was found to be ~1–4 GPa–1. At Site C0004, compaction rates and compressibility are elevated in the vicinity of the fault zone. At Site C0007, healing rates decrease, and compaction rates increase, with increasing depth.

1 Ikari, M.J., Knuth, M.W., Marone, C., and Saffer, D.M., 2012. Data report: frictional healing and compressibility of sheared sediment from fault zones, Sites C0004 and C0007. In Kinoshita, M., Tobin, H., Ashi, J., Kimura, G., Lallemant, S., Screaton, E.J., Curewitz, D., Masago, H., Moe, K.T., and the Expedition 314/315/316 Scientists, Proc. IODP, 314/315/316: Washington, DC (Integrated Ocean Drilling Program Management International, Inc.).

2 Department of Geosciences, The Pennsylvania State University, University Park PA 16802, USA. Correspondence author:

3 Current address: MARUM, Center for Marine Environmental Sciences, Universität Bremen, 28359 Bremen, Germany.

4 Department of Geoscience, University of Wisconsin-Madison, Madison WI 53706, USA.

Initial receipt: 18 April 2011
Acceptance: 11 April 2012
Publication: 13 July 2012
MS 314315316-219