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Seismic measurements of the internal properties of fault zones

Pure and Applied Geophysics PAGEOPH

By:
and
DOI: 10.1007/BF00875723

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Abstract

The internal properties within and adjacent to fault zones are reviewed, principally on the basis of laboratory, borehole, and seismic refraction and reflection data. The deformation of rocks by faulting ranges from intragrain microcracking to severe alteration. Saturated microcracked and mildly fractured rocks do not exhibit a significant reduction in velocity, but, from borehole measurements, densely fractured rocks do show significantly reduced velocities, the amount of reduction generally proportional to the fracture density. Highly fractured rock and thick fault gouge along the creeping portion of the San Andreas fault are evidenced by a pronounced seismic low-velocity zone (LVZ), which is either very thin or absent along locked portions of the fault. Thus there is a correlation between fault slip behavior and seismic velocity structure within the fault zone; high pore pressure within the pronounced LVZ may be conductive to fault creep. Deep seismic reflection data indicate that crustal faults sometimes extend through the entire crust. Models of these data and geologic evidence are consistent with a composition of deep faults consisting of highly foliated, seismically anisotropic mylonites. ?? 1986 Birkha??user Verlag, Basel.

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Seismic measurements of the internal properties of fault zones
Series title:
Pure and Applied Geophysics PAGEOPH
DOI:
10.1007/BF00875723
Volume
124
Issue:
1-2
Year Published:
1986
Language:
English
Publisher location:
Birkha??user-Verlag
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
Larger Work Title:
Pure and Applied Geophysics PAGEOPH
First page:
141
Last page:
157