DIGITAL SPATIAL ANALYSIS OF PHOTOREALISTIC 3D GEOLOGIC MODELS OF THE PENNSYLVANIAN HARTSHORNE SANDSTONE SEQUENCE OF HUCKLEBERRY CREEK SPILLWAY IN CENTRAL ARKANSAS

The Huckleberry Creek Spillway, located in Central Arkansas, is part of the Hartshorne Sandstone sequence of Pennsylvanian age. The spillway, which exposes the sequence in two places, gives a clear view of the three-dimensional aspects of the geology in the area. The spillway is often visited by students involved in sedimentology and stratigraphy classes, as well as industry leaders. In the spring of 2007, a group of undergraduate students planned, researched, and organized a project to digitally capture portions of the two exposures with the use of a Riegl LPM 800 terrestrial laser scanner, as well as RTK GPS equipment and a high resolution digital camera. Photorealistic 3D models of the exposed outcrop were then created from the laser scanned data in concordance with the high resolution photographs. The finished models were then geo-referenced using control reflectors which were positioned along the outcrop and tied to a nearby Continuously Operating Reference Station. Once completed and referenced, the models were spatially analyzed using software developed at The University of Texas at Dallas, as well as commercial software. With the use of this software, several geologic measurements were made, including bed thickness, strike and dip, as well as the trend and plunge of the various exposed sedimentary structures. The digital measurements of the spillway and the geologic structures it embodies are invaluable to both students and industry leaders alike.