QUATERNARY LANDSCAPE DEVELOPMENT OF THE WHITE RIVER BADLANDS, SOUTH DAKOTA

Badlands are a common landform assemblage in arid and semi-arid landscapes, however their Quaternary development is poorly understood. This work addresses that knowledge gap by applying isotopic and luminescence age analysis to exposed sediments in the White River (WR) Badlands of South Dakota. These badlands are of increasing interest to Quaternary scientists and have recently been suggested to be a significant source of the rapidly accumulated Peoria Loess of Nebraska. This work is important for understanding 1) the long-term development of Badlands, 2) the development of the Great Plains landscape, and 3) paleoenvironmental conditions of the Central Plains. Quaternary deposits are well exposed along table uplands between the White and Cheyenne Rivers in the WR Badlands and have been recognized for decades. Uplands between tributaries of the White River have an elevation of ~830 m, and uplands between the White and Cheyenne River Basins have an elevation of ~950 m. Fluvial, eolian and colluvial sediments unconformable overlie the Tertiary White River Group at both elevations. Gastropods and buried soils are commonly found within these sediments. Specifically, the hypothesis being tested here is that the upland table surfaces formed at different times because badlands erosion has been cyclical throughout the Quaternary.