Overlap Timing Styles

1. Foreland uplift
   displaces thrust sheets
   (Example in NE Utah)
2. Foreland uplift
   occurred before
   thrust
   emplacement
   (Example in SW Montana)

Overlap Types

1. Thrust over normal fault
   Normal faulting in Paleozoic to Mesozoic is overlapped by Sevier thin-skinned thrusting, then the normal fault is reactivated during Laramide uplift. The result can be a complicated region with young strata over older strata in a reverse faulting regime. (Example in SW Montana)
2. Foreland cutting thrust in opposite direction.
   Reverse faulting dipping east from Laramide uplift displaces eastward verging Sevier thrusting. (Example near Idaho-Wyoming border)
3. Foreland cuts under thrust sheet in same direction
   Thick-skinned west dipping uplift occurred after thin-skinned placement. (Example in SW Montana)