The proposed research is an investigation of the paleoclimatic significance and late-Quaternary history of sand dune fields and lunettes (dunes fringing playa basins) on the Southern High Plains. Three principal hypotheses will be tested: 1) the sand dune fields on the Southern High Plains formed synchronously between 9000 and 4500 yrs B.P., since 1000 yrs B.P., and historically; 2) the lunettes of the Southern High Plains formed synchronously and episodically during the late Quaternary and were derived from sediments in adjacent playas during droughts; 3) Holocene construction of the sand dunes and the lunettes occurred synchronously and was the result of regional drought. There are several significant aspects of the research. The record of dune construction and dune movement should provide a long-term (late Quaternary) record of drought and wind erosion of the High Plains surface. Studying the historic record of dune activity along with historic climate data will begin to provide some estimates of the climatic thresholds that must be crossed before desertification begins in the region. Studying the lunettes is also important because they are the only sites of deposition on the Llano Estacado with a demonstrated potential for a dateable paleoenvironmental and stratigraphic record spanning the past 30,000+ years. The proposed research on the Southern High Plains complements current dune studies on the Northern High Plains (sponsored by NSF, USGS, and NASA) and will contribute to a subcontinental-scale view of late-Quaternary eolian erosion and sedimentation and attendant climatic implications.
