A TALE OF TWO RIVERS: FLUVIAL RECORDS OF COMPETING MOISTURE SOURCES IN A BROKEN EOCENE FORELAND
This study compares and contrasts the fluvial architecture and sedimentology of these two fluvial systems to assess differences in allogenic influences on each river and consider how each system influenced the dynamic and evolving hydrology of Lake Gosiute. To quantify these systems from outcrops across the basin, we collected detailed outcrop sedimentologic observations as well as 3D models generated using structure-from-motion photogrammetry from unmanned aerial vehicle imagery. Pairing of these data permits the assessment of fluvial deposits at both the micro (e.g. sedimentary structures) and macro (e.g. channel architectures) scales, enabling a more holistic understanding of the nature of these rivers. Preliminary results indicate larger grainsizes, larger sedimentary structures, a higher degree of amalgamation, and larger fluvial architectures in the deposits of the Idaho paleoriver compared to those of the Aspen paleoriver, suggesting that the Idaho paleoriver was not only notably larger than the Aspen paleoriver, but likely more perennially established as well.