Fig. 7. Photographs of the Crucifix fault zone and sampling localities denoted by numbers. Photos highlight fault zone architecture. (A) Note drag geometry and deformation of fault gouge appears similar to that of a clay smear process (Yielding et al., 1997) parallel to the main slip surfaces. (B) Close-up view of fault core. In hand sample we observed a decrease in grain size in the central fault core gouge and numerous small-scale en echelon slip surfaces. X-ray diffraction of Sample BT-43-01 yields calcite mineralization on the outer slip surface and quartz and feldspars comprise the central gouge zone. (C) Closely spaced fractures between two faults that show the relationship between grain size and degree welding and fracture density. The white ash-rich beds (A) have numerous fractures that do not persist into the nonwelded pumice-rich layers (P).