Data Report: Permeability, porosity, and frictional strength of core samples from IODP Expedition 366 in the Mariana forearc

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Abstract

Core samples from the International Ocean Discovery Program (IODP) Expedition 366 were tested in the laboratory to determine permeability, porosity, density, and frictional strength and their relation to mineralogy as part of an effort to understand hydro-mechanical processes at convergent plate margins. Seven samples were tested from a depth range of 19.6 to 197.9 m below the sea floor. The samples were derived from three serpentinite mud volcanoes in the Mariana forearc region, formed where slab-derived fluids and materials ascend along faults. The physical characteristics mirror compositional differences between predominantly serpentine-rich and saponite-rich samples. Permeability values ranged from 10-17 to 10-19 m2, low enough to facilitate the formation of high fluid pressures, which have been observed in the Mariana and other subduction megathrust environments. Porosities ranged from 0.37 to 0.51 and densities from 1.66 to 2.01 gm/cc. Serpentine-rich samples have coefficients of friction of 0.2 to 0.4, consistent with crustal serpentinite from a variety of fault zones, whereas saponite-rich samples have friction values below 0.2, consistent with saponite fault gouge from the San Andreas Fault Zone at Depth (SAFOD) drillhole in California.

Additional publication details

Publication type Book chapter
Publication Subtype Book Chapter
Title Data Report: Permeability, porosity, and frictional strength of core samples from IODP Expedition 366 in the Mariana forearc
DOI 10.14379/iodp.proc.366.202.2019
Volume 366
Year Published 2019
Language English
Publisher IODP
Contributing office(s) Hydro-Ecological Interactions Branch, Earthquake Science Center
Description 14 p.
Larger Work Type Conference Paper
Larger Work Subtype Conference Paper
Larger Work Title Proceedings of the International Ocean Discovery Program