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 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