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 the Cambrian. Sediments are a mixture of fluvial conglomerates, sandstones, and siltstones. Several pull-apart structural grabens formed at flexures in the orogenic belt, forming the Levenger and Moorilyanna Grabens. The Petermann Orogeny is dominated by south-over-north movement on several large, anastomosing curved thrust faults. The prime thrust fault is the Woodroffe Thrust, which is a laminated pseudotachlyte-schist zone up to 300 metres thick. This has accommodated up to 42 kilometres of vertical movement at an angle of about 15 to 20 degrees. The structure of the Petermann Orogen within the Musgrave Block is considered to be a "flower-structure", which is