Permeability structure around an ancient exhumed subduction-zone fault
Article first published online: 17 MAR 2004
Copyright 2004 by the American Geophysical Union.
Geophysical Research Letters
Volume 31, Issue 6, March 2004
How to Cite
2004), Permeability structure around an ancient exhumed subduction-zone fault, Geophys. Res. Lett., 31, L06602, doi:10.1029/2003GL019183., , , , and (
- Issue published online: 17 MAR 2004
- Article first published online: 17 MAR 2004
- Manuscript Accepted: 13 FEB 2004
- Manuscript Revised: 21 JAN 2004
- Manuscript Received: 27 NOV 2003
 We conducted permeability measurements on rocks sampled from an exhumed ancient subduction zone fault in the Cretaceous Shimanto accretionary complex of Japan. The permeability under seismogenic environment conditions shows a heterogeneous structure across the fault zone. Permeability of the sandstone in turbidite sequence is the lowest, whereas the highly sheared zone has the largest permeability. A combination of permeability contrast between these two zones and fluid pressure source, including tectonically driven burial and dehydration, could result in a concentration of pore fluids along the fault, which causes Deep Seismic Reflections during underplating stage as delineated in seismic reflection studies. Following a rise of temperature up to 250°C, the permeability of all the sampled rock types became smaller than at room temperature, and also gradually decreased with increasing hold time.