CARBONATE FACIES OF THE OWL MOUNTAIN AREA, FORT HOOD MILITARY INSTALLATION, BELL COUNTY, TEXAS

The Owl Mountain region within the Fort Hood Military Installation covers approximately 90 square kilometers and is located along the eastern portion of Fort Hood with lower Cretaceous limestones, clays and marls outcropping at the surface. The study area is bounded by Owl Creek to the north, Lake Belton to the east, Cowhouse Creek to the south, and the live fire impact range to the west. The lithology of the Owl Mountain area consists of the Walnut Clay in the valleys and undivided members of the Washita and Fredericksburg Group, including the Edwards Limestone, in the exposed scarps. The Edwards Limestone has been extensively researched and studied in its southern exposures and aquifers, but no detailed studies have been published within the confines of this study area and the northern edge of the Edwards aquifer system. Current stratigraphic mapping and correlation in the area has identified a series of carbonate mound structures exhibiting facies gradation between lagoonal mudstone facies, peloidal wackestone facies and coarse-grained, rudistid-rich, grainstone facies. Strata indicates a shoaling upward depositional sequence as accommodation space was occupied by spatial expansion marginal mound complexes.