LUNETTE DUNES ON THE HIGH PLAINS OF WESTERN KANSAS: HIGH-RESOLUTION RECORDS OF PALEOENVIRONMENTAL CHANGE AND GEOMORPHIC EVOLUTION

The High Plains region of the central United States is a vast, low-relief landscape that contains thousands of small, depressional playa wetlands. Lunettes are isolated dunes that form along the downwind margin of some larger playas and are composed of sediment deflated from the playa as well as regional loess deposits. Because lunettes are landforms that are a result of prolonged periods of deposition, they preserve high-resolution records of past environments and geomorphic processes. Intercalated sedimentary units and buried soils dominant the stratigraphy of lunettes.

The purpose of this research was to inventory and map all the lunettes associated with playas in Kansas. Lunettes were mapped in a GIS environment by visually scanning 1:24,000 scale digital raster graphics and digital elevation models for a 43-county region. Results indicate there are 129 lunettes in Kansas associated with 104 playas. Lunettes were identified in 20 counties, with the greatest density within Finney, Gray, Lane, and Scott counties. Most lunettes are subtle features with median height and surface area of 3 m and 10 ha, respectively. Most lunettes were located along the southeast margin of playas, suggesting winds were predominantly from the northwest during lunette development. Lack of high-resolution data, particularly in the northwest portion of the state, constrained lunette identification and mapping and likely resulted in omission of several lunettes.

The lunette database provides a valuable resource for archaeologists, allowing researchers to better identify locations that have a high probability to preserve artifacts. Because lunettes preserve high-resolution sedimentary records, the lunette database also provides an inventory of locations that contained detailed records of past environments and geomophic processes. As such, this database can aid in our understanding of the peopling of the Americas as well as the geomorphic and vegetation response of playas and lunettes to climate change.