Date of this Version
The Rainbasin area of south-central Nebraska is an important component of the central flyway of migratory waterfowl. Little is known or has been reported about the morphology of large basins in the Rainbasin. A subsurface investigation was conducted to determine the morphology of two basins in Clay County, Nebraska. Transects were located across two sample areas, and seventeen test holes were drilled to determine loess thickness and stratigraphy. Radiocarbon dates were obtained from buried paleosols. The modern basin landscape was determined to be a direct result of 2.5 to 8 m of loess deposition on an older basin landscape. The modern landscape generally mirrors the paleolandscape except that the modern basin ridges seem to have less relief than the paleoridges. The paleobasins were formed prior to the Early Wisconsinan deposition of the Gilman Canyon Formation. It is likely that other large basins within the eastern Rainbasin are underlain by paleobasins and are the result of prior basin-forming processes.