Print this page
Temporal and spatial evolution of
damage zones along small-displacement faults adjacent to the seismogenic San
Jacinto 
fault
, southern California
Eliza Nemser
University of Washington, Department of Earth and Space Sciences
Seattle, Washington
Damage zones are characterized by deformation
that accumulates in a volume around the fault core as a result of fault slip.
Recent theoretical models of brittle fault-zone development based on principles
of fracture mechanics describe the dependence of damage zone width on the
velocity of crack propagation. According to these models, if fault development
involves both quasistatic fault growth and dynamic slip, structures within the
damage zone may record the distinctive signatures of these different fault
behaviors. In this study, I use detailed field observations of the spatial and
temporal relationships between structures within the damage zones of
small-displacement faults with relatively little damage-zone complexity to
investigate the history of fault slip. Small-displacement faults within the
Pliocene-Pleistocene San Timoteo formation adjacent to the San Jacinto fault
zone in southern California are ideal for this study as they are well-exposed
and are reasonably inferred to have been seismically active.
AAPG Search and Discovery Article #90060©2006 AAPG Foundation Grants-in-Aid