BRUTE3 AND SELECT - QUICKBASIC 4 PROGRAMS FOR DETERMINATION OF STRESS TENSOR CONFIGURATIONS AND SEPARATION OF HETEROGENEOUS POPULATIONS OF FAULT-SLIP DATA

BRUTE3 is an objective, nonelegant method of inversion of fault-slip data. Thousands of tensor configurations (orientation and relative magnitude of principal stress axes) are tested against a collection of data. Mohr-Coulomb yield criteria are considered during inversion. A tensor configuration is considered acceptable, saved and displayed if: (1) the predicted slip direction is approximately parallel (within user specified limits) with the actual slip direction (slickenline orientation); (2) the yield strength of the discontinuity (the fault plane) is exceeded, that is tau > C + mu-delta-n; and (3) more than a specified percent of faults in the data collection satisfy (1) and (2). A cluster of similar tensor configurations will be determined for each computationaly compatible subset of faults in the data collection. These configurations provide a guide by which to separate the collection; SELECT facilitates separation. A computational compatible subset of faults is culled from the data collection based on a tensor configuration, fault geometry, and Mohr-Coulomb yield criteria.