Possible Flexural Controls on the Origins of Extensive, Ooid-Rich, Carbonate Environments in the Mississippian of the United States
Frank R. Ettensohn, 1993. "Possible Flexural Controls on the Origins of Extensive, Ooid-Rich, Carbonate Environments in the Mississippian of the United States", Mississippian Oolites and Modern Analogs, Brian D. Keith, Charles W. Zuppann
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Widespread ooid deposition characterized much of the United States during the Mississippian and was the product of an unusual coincidence of ideal regional paleogeographic and tectonic factors, as well as global paleo- climatic, eustatic, and geochemical conditions. The contribution of tectonics, largely through flexural mechanisms, is considered to have had the greatest effect.
During the Mississippian, parts of three orogenic belts, the Antler, the Ouachita, and the Acadian, bounded southern parts of North America in the present-day United States. Various active and relaxational phases of these orogenies generated peripheral bulges that migrated within and beyond foreland basins to adjacent parts of the foreland, creating broad areas of uplift into shallow, agitated waters conducive to ooid production.
During the Early Mississippian (Kinderhookian), bulge migration and uplift were incomplete, so ooid distribution was limited. By the middle Mississippian (Valmeyeran), episodes of coeval Antler and Ouachita flexure combined with Acadian relaxation created broad belts of uplift on the inner craton, where the most prolific ooid production occurred. In the Late Mississippian (Chesterian), largely filled foreland basins and rising tectonic highlands caused siliciclastic inundation of adjacent sites of ooid production, resulting in thinner, more localized ooid deposits. By the end of the middle Chesterian, all major concentrations of Mississippian ooids had disappeared.
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A coincidence of tectonic, eustatic, and geochemical conditions resulted in substantial deposits of oolitic limestone during later Mississippian time in the continental United States. These oolitic limestones have formed petroleum reservoirs with favorable primary and secondary recovery characteristics. Significant potential reserves in stratigraphic traps remain to be discovered and developed in these reservoirs.