Subsidence and Burial Histories of the Fort Worth Basin Reflect Prolonged Ouachita Orogeny during the Mississippian-Permian

摘要

The Fort Worth Basin in north-central Texas, U.S.A., is one of the major hydrocarbon production systems of the Marathon-Ouachita-Appalachian Orogeny, which was formed due to the collision between Laurentia and Gondwana during the Paleozoic (Walper, 1982; Thompson, 1988; Erlich and Coleman, 2005; Elebiju et al., 2010) (Fig. 1). The basin is bounded by the Red River and Muenster arches to the north, the Ouachita fold-and-thrust belt to the east, the Llano Uplift to the south, and the Bend Arch parallel to the Ouachita structural front to the west (Fig. 1). Current studies to the Fort Worth Basin mainly focus on hydrocarbon exploration and production (Pollastro, 2003; Thomas, 2003; Jarvie et al., 2005), and the subsidence history of the basin and its dynamic relationship to the Ouachita thrust belt remain controversial Previous studies suggested that the Ouachita fold-and-thrust belt to the east of the Fort Worth Basin was the main sediment source during the Late Mississippian-Late Pennsylvanian (e.g., Walper, 1982; Grayson et aL, 1991; Noble, 1993; Pollastro, 2003). However, others suggested that the Muenster Arch to the north of the Fort Worth Basin was the primary sediment source during the Early Pennsylvanian (Lovick et al., 1982; Thomas, 2003), and the Arch caused subsidence of the basin as early as the Mississippian (Loucks and Stephen, 2007). The post-Pennsylvanian strata are poorly preserved in the Fort Worth Basin, limiting our understanding to the post-Pennsytvanian subsidence history of the basin. Current understanding to the post-Pennsylvanian burial and exhumation history of the basin can be classified into two schools of thought: (1) Grayson et aL (1991) and Montgomery et aL (2005) suggested that sediment accumulation lasted into the Permian, and no additional sedimentation occurred until the Early Cretaceous; and (2) Jarvie et aL (2005) and Ewing (2006) argued that the basin experienced exhumation during the Late Triassic-Jurassic as a result of rift-shoulder uplift during the opening of the Gulf of Mexico. Erlich and Coleman (2005) have reconstructed the subsidence history of the basin and their work suggested that the Late Mississippian-Pennsylvanian subsidence rate in the northern part of the basin was two times higher than the southwestern part of the basin. Because the work did not correct for sediment compaction and loading, the tectonic subsidence rates were overestimated.