Chapter 8 - The Southern Midcontinent, Permian Basin and Ouachitas

Abstract

This chapter is concerned with the southern portion of the craton, the southern craton margin, and its geological relationship with the Ouachita orogeny. The southern continental margin was shaped by extensional and transform faulting, during the breakup of Rodinia, and includes the Oklahoma Basin, a basin formed by transtensional faulting. Carbonate reef systems flourished along the entire continental margin from Texas to Newfoundland during the early Paleozoic. Shallow-water, carbonate, and siliciclastic sedimentation continued in the Oklahoma Basin from Middle Ordovician through earliest Mississippian time. The ocean that lay south of the North American plate through much of the Paleozoic was closed by collision with Gondwana, starting in the mid-Mississippian. Northwesterly directed contractional stress generated a regionally distinctive style of transpressive fault and block-uplift deformation across the southwestern United States. Mild warping of the Texas-Oklahoma area during this period accentuated existing differentiation of the continent into a series of basins (including the Delaware and Midland basins) and intervening uplifts (Diablo Platform, Central Basin Platform, Eastern Shelf, Llano Uplift, Ozark Uplift). That portion of this basin and uplift system located within Texas now constitutes the classic Permian Basin. The carbonate-platform and basin configuration of the Permian Basin is similar in topography and scale to that of the Cretaceous to modern Bahamas Platform. The basin is probably best known for the distinctive “clinoform” stratigraphy of the Capitan Reef, one of the first places where the lateral facies transition from back reef, through reef crest, fore-reef slope to basin floor was mapped and described in detail, based on superb outcrops in the Guadalupe Mountains. The Permian Basin is one of the most productive in terms of oil and gas resources, with recent developments in the exploitation of tight oil and shale resources bringing about a major revitalization of the basin.