DEPOSITIONAL ENVIRONMENT AND FACIES ANALYSES OF THE OWL MOUNTAIN PROVINCE, FORT HOOD MILITARY INSTALLATION, TEXAS

The Owl Mountain Province is a plateaued, karst landscape located in the eastern section of the Fort Hood Military Installation and characterized by Lower Cretaceous Fredericksburg Group carbonates. The topography is capped by thick sequences of the Edwards limestone; steep scarps and incised valleys along the edges host inter-fingering outcrops of the Edwards and Comanche Peak limestones, and the lower valleys are covered by alluvial sediments and intermittent outcrops of the Walnut Clay. These formations were deposited to the north and west of the main Edwards trend, and are thought to be one of the isolated shoals that developed in a restricted environment on the Comanche Shelf associated with the western flank of the Belton High.

In order to correlate and understand the depositional environment and facies development of the study area, detailed surface mapping and stratigraphic analyses of vertical and lateral facies changes have been ongoing in the Owl Mountain Province, with 21 distinct bio-and-lithofacies identified based on bulk rock descriptions. Facies in the study area reflect a complex depositional environment consistent with restricted shallow shoals adjacent to or on the flanks of developing carbonate mounds. Continued analyses will help refine these facies, and further describe the depositional environment, diagenetic history, and geomorphic evolution of the Owl Mountain Province. Detailed bio-and-lithofacies analyses will also enable the correlation of karst development to local stratigraphy by delineating zones that support the development of lateral and vertical fluid migration paths and conduit development.