Authors: Miranda Jordan*, Missouri State University, Robert Pavlowsky, Missouri State University, Marc Owen, Missouri State University
Topics: Geomorphology, Water Resources and Hydrology
Keywords: Legacy sediments, Missouri, mining
Session Type: Poster
Start / End Time: 8:00 AM / 9:40 AM
Room: Napoleon Foyer/Common St. Corridor, Sheraton, 3rd Floor
Presentation File: No File Uploaded
Floodplains function as long-term storages of sediment delivered from the watershed and therefore are often targeted for stratigraphic analysis to evaluate past records of environmental disturbances. Human activities can increase flooding and sediment loads resulting in higher sedimentation rates and the formation of legacy deposits on floodplains. This study evaluates the sedimentary and geochemical characteristics of legacy floodplain deposits along the lower portion of Big River watershed (2,500 km2) which drains the Ozark Highlands in southeast Missouri. Upland erosion occurred during the agricultural settlement period beginning in the 1700s and peaking in the late 1800s. In addition, Big River received large volumes of mine tailings generated from the Old Lead Belt District which was a world leader in lead production from the early 1900s to 1972. Previous research indicates that legacy deposits from 1 to 4 m thick occur on floodplains of Big River. However, this study is the first to examine high resolution core records using sediment properties, metals analysis, Cs-137, and magnetic susceptibility to identify discrete sediment events and attempt to link floodplain strata to historical disturbances along the lower segment of Big River near the USGS gage at Byrnesville, Missouri. Results include: (i) review of watershed settlement and mining history; (ii) summary of previous floodplain data; and (iii) preliminary analysis of new cores collected in Winter 2018.