LATE WISCONSIN AND HOLOCENE LANDSCAPE CHANGE AND BURIED SITE POTENTIAL OF BROUILLETTS CREEK

Climate, tectonics, and drainage-basin characteristics dictate the conditions that control the discharge and sediment dynamics of rivers in continental interiors. Fluvial-system response and a partial human record have been recorded in valley landscapes. Regional patterns in the timing of sedimentation in the present day Midwestern United States have been recognized in several case studies throughout the region. However, there is much more that can be done to better understand climate change and climate responses in the region and particularly along the Wabash River in Indiana and its tributary streams. This study focuses on the Late Wisconsin and Holocene landscape change at two locations along the Brouilletts Creek in Vermillion County, IN and Edgar County, IL. The purpose of this study is to define allostratiagraphic units for the Brouilletts Creek flood plain. The descriptions will be used to reconstruct the local landscape changes. A comparison of the local changes will add to the identification of global and regional changes in the environment reflected in the geologic units. As a consequence, a buried site potential model will be constructed by analyzing the age and depositional environments represented in allostratiagraphic units. The buried site potential model will also provide information about possible site locations and how and where people may have utilized the changing landscape.

First, a site north of the coal mining and south of the coal mining have been selected in order to investigate the influence of the mining on the alluvium. Second, Magnetic Susceptibility and Loss on Ignition have been performed to identify A horizons of buried units in order to locate these units in the cores. Third, core descriptions, including texture, color, and grainsize have been used to describe to compare to previously recorded units. Fourth, both radiocarbon and lead dating have been employed in order to date the buried soils because their ages are currently unknown and the units will need context in order to better understand their formation. And finally, a buried site potential model using the unit descriptions and spatial data has been created.