Late Palaeozoic basins of the southern U.S. continental interior

Abstract

The timing and geometry of late Palaeozoic inhomogenous deformation in the southern U.S. continental interior from the Appalachian foreland of Kentucky-Tennessee through Oklahoma and Texas to the Ancestral Rockies of Colorado-Wyoming-Utah can be definitively linked with a discrete sequence of collisional events in the Appalachian-Ouachita-Marathon orogenic belt to the south (Permian coordinates). A progressive staged collisional sequence beginning in late Mississippian times in the southern Appalachians and culminating in early Permian times in the Marathons led to a progressive deformation of the adjacent craton in a wide swath dominated by right-lateral shear (e.g. Rough Creek Fault zone) by which a Mexican promontory of North America was displaced towards a Pacific ‘free face’. While the deformation in the Appalachian-Marathon belt was dominated by vertical plane strain leading to crustal thickening, the associated continental interior deformation can be averaged as a horizontal plane strain at or near sea level with localized deep extensions (Delaware) and flexural (Arkoma) basins and compressions uplifts (Amarillo-Wichita) giving local source areas.