REMOTE SENSING CHARACTERIZATION OF STRUCTURAL CONTROL AND ORIGINS OF SINKHOLE DEVELOPMENT, FORT HOOD MILITARY INSTALLATION, TEXAS

The Fort Hood Military Installation is a karst landscape characterized by Cretaceous-age Comanchean Series carbonates of the Trinity and Fredericksburg groups; deposited as part of the major sedimentary sequences during the Zuni transgression. The 105km² study area is located in the eastern section of the installation known as the Owl Mountain Province and has been described as a mound or shoal that formed on the Comanche Platform to the northwest of the Stuart City Shelf Margin. Spatial interpolation of LiDAR (Light Detection and Ranging) data of the province provided delineated depressions that were classified using geoanalytical methods. This area is utilized by the U.S. Army for troop maneuvers and training, so depression data was filtered to remove anthropogenic terrain modifications associated with land use.

Orientation and asymmetry were calculated for the remaining 1,538 depressions believed to represent karst features, and compared to regional structural trends. The orientation of these surface depressions has been controlled by the development of transmissive conduits along deformational trend of the Balcones/Ouachita fault system (22°) and the transverse Belton High-Moffatt Mound trend (285°). These trends also correlate with cave development in the subsurface, joints in outcrop, stream segment orientation, and the transmission of ascending fluids in the study area. Asymmetry calculations showed that 53.4% (n=821) of the depressions were symmetric and may be associated with surficial expressions of collapse features; 46.6% (n=717) were asymmetrical and may be associated with epikarst processes.