Ouachita orogeny Ouachita orogeny The Ouachita orogeny was a mountain building event that resulted in the folding and faulting of strata currently exposed in the Ouachita Mountains. The more extensive Ouachita system extends from the current range in Arkansas and Oklahoma southeast to the Black Warrior Basin in Alabama and to the southwest through the Llano, Marathon, and Solitario uplifts in Texas on into Coahuila and Chihuahua in Mexico. The region during the early Paleozoic lay off the coast of the southern portion of Laurentia, in what is now the southern United States. Laurentia straddled the equator at the time and the
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