EVENT LAYERS IN CORES FROM THE TENNESSEE RIVER FLOODPLAIN: DESCRIPTION, INTERPRETATION, AND IMPLICATIONS

Flood events can leave an imprint in stratigraphic records as event layers or flood deposits. These event layers are indicators of past events and when analyzed, they provide information that can allow researchers to reconstruct chronologies of paleoflood events and understand past conditions. Researchers at the University of Tennessee Departments of Earth and Planetary Sciences and Geography are investigating paleoflood deposits in the Upper Tennessee River to help define the record of flooding in this area and help inform flood risk analysis. In November 2017, six cores were extracted from the East Tennessee Research Center – Plant Sciences Unit (ETREC) near Knoxville, in floodplains deposits of the Tennessee River, for analysis of paleoflood deposits and charcoal sampling for radiocarbon dating. Soil coring and collection of samples were done using a Giddings Probe, which is a coring instrument mounted on the back of a truck and operated by a trained professional. Cores were extracted from different sites based in part on model predictions of where possible floods could have left traces in the soil records. Analyses of the cores, which are still underway, include core photography, and detailed sedimentological analyses including grain size, magnetic susceptibility, and X-Ray Fluorescence Analysis (XRF). The goal of this multi-proxy approach is to determine paleoflood deposits in the Upper Tennessee River floodplains and their characteristics. As well, the analysis of the cores with a multi-proxy approach will be useful to select other types of methods such as thin section analysis and radiocarbon or optical stimulated luminescence dating for future work with the cores. This will allow for a better understanding of the past behavior of the Tennessee River, identification of past conditions, and potential regional climatic implications.