Abstract
This study investigates the surface to subsurface relationship at Longhorn Cavern State Park, which can become one part of an interdisciplinary educational program taught at the park. Longhorn Cavern is located on Backbone Ridge; a wedge shaped topographically high graben, which is bounded by Pennsylvanian age normal faults. The phreatic cavern passages were fully developed by the Pleistocene, and it is currently a shallow (< 40 m) dry cavern. The combination of the 1-meter resolution digital orthophoto quadrangles (DOQ's) with a 1971 topographic map (CI=2ft) yields a map with a 1-meter resolution horizontal scale and a 0.62 m (2-ft) vertical scale. This map provides an accurate representation of the surface in which the karst features can be identified and evaluated. Sinkholes smaller than 15,834 m² only occur within 150 m of the cavern, creating a recognizable "cavern footprint" on the surface. The clints, grikes, solution pans, rills, and other karren features indicate there was little to no soil cover in the sinkholes within 150 m of the cavern before European settlement in the area. The linear trending cavern passages suggest structural control of the cavern, but the structural data when compared to individual passage trends and individual passage morphology proves lithologic control of Longhorn Cavern with local joint control. Longhorn Cavern trends parallel to subparallel the strike of the Gorman Formation in the Ellenburger Group, discharging along the Roaring Springs Fault Zone. Longhorn Cavern provides an excellent opportunity to illustrate for teaching purposes how the convergent and multiple processes work to create a landscape.
McCaleb, Brenda Denise (2000). The surface expression of Longhorn Cavern, Burnet County, Texas. Master's thesis, Texas A&M University. Available electronically from
https : / /hdl .handle .net /1969 .1 /ETD -TAMU -2000 -THESIS -M3307.