Laramide orogeny Laramide orogeny The Laramide orogeny was a period of mountain building in western North America, which started in the Late Cretaceous, 70 to 80 million years ago, and ended 35 to 55 million years ago. The exact duration and ages of beginning and end of the orogeny are in dispute. The Laramide orogeny occurred in a series of pulses, with quiescent phases intervening. The major feature that was created by this orogeny was deep-seated, thick-skinned deformation, with evidence of this orogeny found from Canada to northern Mexico, with the easternmost extent of the mountain-building represented by the Black Hills of
Petermann Orogeny a set of vertically arcuate thrust faults which dip toward each other and accommodate vertical movement by essentially "squeezing" the central block up and out. Several northeast trending discontinuities including the Mundrabilla lineament divide the Petermann orogeny, with extensive vertical offsets across them, usually west-side-up, though the timing of this event is unknown. Six deformations are known (to be completed) Foliations associated with the Petermann Orogeny are typically steeply to gently south-dipping and subparallel to the thrust faults upon which they were developed. S regionally pervasive stretching lineation is potentially associated with some of these faults, especially in the deeper