| Using Striation Data to Understand the Mechanics of Faulting in Heterogeneous Stress Fields | |
| Personnel: J.O. Kaven and D.D. Pollard Collaborators: L. Maerten and F. Maerten Sponsor: Stanford Rock Fracture Project | |
Description:
This project investigates the feasibility of paleo-stress inversion from fault striation data. Methods for stress inversion
from such data on single or multiple faults are based on the assumptions that the stress tensor is spatially and temporally
uniform throughout the rock that contains the faults, and that slip on each fault has the same direction and sense as the
maximum shear stress resolved on it from the remote stress tensor. Deviations of the slip from the maximum shear stress can
result from the curved shape of the fault and its tipline, anisotropy of fault friction, heterogeneity of host rock stiffness,
and perturbation on the local stress field. However, the errors introduced by these natural heterogeneities may not be
significant for all geologic settings. A field example from Chimney Rock, Utah, is used to examine the effects on different
fault mechanisms and the temporal development of distinct fault sets. Systematic forward models using Poly3D constrain criteria
that help identify the conditions under which paleo-stress inversion is feasible.
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| Selected Publications: D.D. Pollard, S.D. Saltzer, and A.M. Rubin, 1993, Stress inversion methods: are they based on faulty assumptions?, JSG, Vol.15, No.8 pp. 1045-1054 | |