A Method for Estimating Fault Geometry from Rotated Basement Blocks Using Slip Lines

The geometry of the uppper basement surface displacement field in structures uplrfted by reverse faults can be used to predlct fault surface geometry at depth A method a described that uses sllp lmes whlch define the motion of the uplifted basement block and assumes that faults are curved and become parallel to the reg~onal basement surface beyond the lateral extent of the associated rotated block The method assumes constant shortening mth depth, 1s a "balanced" base- ment model, and provldes an estimate of the amount of horlzontal shortening. The method 1s applled to an example struc- ture ln the northeastern Blghorn Mountam, Wommng