Georgia State University ScholarWorks @ Georgia State University Geosciences Theses Department of Geosciences 8-8-2017 Geochemical Signatures of Stream Capture in the Retreating Blue Ridge Escarpment, Southern Appalachian Mountains David DuBose Follow this and additional works at: https://scholarworks.gsu.edu/geosciences_theses Recommended Citation DuBose, David, "Geochemical Signatures of Stream Capture in the Retreating Blue Ridge Escarpment, Southern Appalachian Mountains." Thesis, Georgia State University, 2017. https://scholarworks.gsu.edu/geosciences_theses/108 This Thesis is brought to you for free and open access by the Department of Geosciences at ScholarWorks @ Georgia State University. It has been accepted for inclusion in Geosciences Theses by an authorized administrator of ScholarWorks @ Georgia State University. For more information, please contact
[email protected]. GEOCHEMICAL SIGNATURES OF STREAM CAPTURE IN THE RETREATING BLUE RIDGE ESCARPMENT, SOUTHERN APPALACHIAN MOUNTAINS by DAVID DuBOSE Under the Direction of Katie Price, PhD ABSTRACT Stream capture is a major driver of the retreat of the Blue Ridge Escarpment, but timescales of capture are not well understood. This study examines stream sediment geochemistry to establish a set of sediment source fingerprints which can be used to identify and date the capture of the Tallulah River. Statistical analyses show significant differences in U, Th, and certain REE enrichment. These differences result from variations in bedrock along the lengths of each river and a shift in relative stream powers after capture to favor mobilization or deposition of heavy elements. The observed differences should be sufficient to identify where Tallulah sediment appears in floodplains of the capturing Tugaloo River, facilitating future dating of the capture event.