Deconstructing aeolian landscapes

Semi-stabilized dune systems are important indicators of Quaternary drought variability across central North America. The South Texas sand sheet (STSS) is the southernmost relict dune system on the Great Plains, and is exposed to higher evapotranspiration and moisture variability than similar landscapes farther north. In this study, a combination of surface and sub-surface remote sensing is used to analyze the semi-stabilized dune landscapes of the STSS in order to delineate distinct aeolian sediments that can represent generations of sedimentation or particular climate conditions. The combination of multi-resolution analysis of a LiDAR dataset, electromagnetic conductivity surveys, and XRF scans of soil cores are shown to be useful tools for deconstructing and modeling the environmental history of the STSS. Optically-stimulated luminescence (OSL) dating of identified surfaces suggests that the STSS is older than previously thought. Since dune systems are excellent repositories of climate and biophysical data for a landscape, and are also sensitive to changes in climate and ecology, the methodology employed in this study can be used to characterize the vulnerability of other similar environments to climate change through the Holocene and over the next century.