abstract
Slip vectors, derived from striations on variably oriented faults along the west and south sides of a bedrock spur north of Salt Lake City, Utah, indicate a consistent relative motion between the spur and the Salt Lake Valley during Quaternary time. The possibility of motion of coherent crustal blocks during basin and range type faulting suggests: (1) segmentation of major fault zones, such as the Wasatch fault zone, into independent crustal blocks, complicates the evaluation of earthquake hazards because of the unknown relationships between individual faults; and (2) if this pattern of crustal deformation is characteristic of the Basin and Range Province, then fault-plane solutions for this area should be carefully evaluated because they may reflect local displacements rather than the effects of the regional stress field.
