REMOTE SENSING AND FIELD INVESTIGATIONS OF GEOLOGIC STRUCTURES IN THE OWL MOUNTAIN PROVINCE, FORT HOOD MILITARY INSTALLATION, TEXAS

The Owl Mountain Province is located in the northeastern section of the Fort Hood Military Installation in Bell County, Texas. The strata present in the study area are limestones, dolostones, and marls from the Lower Cretaceous Fredericksburg Group, including the Edwards Limestone. These units were deposited as part of the major sedimentary sequences of the Zuni transgression on the Comanche Shelf behind the Stuart City Shelf Margin and the Central Texas Reef Trend. During the Miocene, Balcones faulting along the Ouachita structural trend exerted extensional forces on recently exposed Fredericksburg Group strata; in the Central Texas region, these rocks are faulted by numerous en echelon normal faults from the Ouachita-Balcones trend. Present day, geologic faults associated with the Balcones have been mapped to the north and south of the province, but no faults have been identified in the study area.

ArcGIS has greatly enhanced the ability to display and analyze different features remotely. Along the northern scarp of the province, a distinct change in lithology, vegetation patterns, and topography occurs and these changes may indicate a previously unmapped fault associated with the Ouachita-Balcones trend. Data provided by the Fort Hood Natural Resources Management Branch was employed to create a suite of maps in order to identify unique geologic, vegetation, and topography changes that indicate geologic structures associated with joints and faults along regional trends. Field verification of geologic structures in the Owl Mountain Province indicates brittle deformation features associated with the Ouachita-Balcones trend are present and may be influencing the hydrogeologic regime controlling topographic changes, soil development, and vegetation associations along the northern boundary of the study area.