HR: 16:45h
AN: T14A-04    [Abstracts]
TI: Fractal Fragmentation in Fault Zones
AU: * Sammis, C G
EM: sammis@usc.edu
AF: University of Southern California, Department of Earth Sciences, Los Angeles, CA 90089- 0740, United States
AB: There is mounting field evidence that the size distribution of particles in fault gouge and breccia is power law with a slope (fractal capacity dimension D) that increases with increasing strain from values near D=2.6 at low strain to values approaching D=3.0 at large strains. This trend is also observed in 3-dimensional computer simulations that allow multiple fragmentation of composite particles. Both the power law distribution and the increase of fractal dimension with strain can be understood using a simple nearest neighbor fragmentation model for "constrained comminution" that predicts a fractal dimension of D=2.6 at low-strain which increases to a stable value of D=3.0 at high strain. The evolution from a gouge with D=2.6 to a cataclasite with D=3.0 is illustrated using an automaton that implements the evolving fracture probabilities calculated using this constrained comminution model.
DE: 5104 Fracture and flow
DE: 7209 Earthquake dynamics (1242)
DE: 8004 Dynamics and mechanics of faulting (8118)
DE: 8010 Fractures and faults
DE: 8159 Rheology: crust and lithosphere (8031)
SC: Tectonophysics [T]
MN: 2007 Fall Meeting