SEDIMENT PROVENANCE USING LASER-ABLATION U-PB DETRITAL-ZIRCON GEOCHRONOLOGY OF GLACIAL AND INTERGLACIAL DEPOSITS OF THE CUTLER GROUP, MOAB, UTAH, USA

Examining differences and similarities in sediment provenance of grains deposited during glacial and interglacial periods is important for understanding sediment transport systems throughout Earth’s history. Research to date has shown that the Pennsylvanian to Permian lower Cutler beds of the Colorado Plateau (USA) contain aeolian, fluvial, and shallow marine facies generated by cyclical changes in climate and eustasy due to the melting and freezing of continental ice sheets during interglacial or glacial periods, respectively. Previous research has also shown that the zircon age spectra from Pennsylvanian to Permian beds in the western United States reflect deposition from local sources, specifically the Yavapai-Mazatzal and Granite-Rhyolite provinces exposed in Ancestral Rocky Mountain uplifts and Appalachian sources, grains of which traveled to the western United States by fluvial, deltaic, and aeolian processes resulting from the regression of the Kaskaskia sea in the Pennsylvanian. Here we use laser-ablation U-Pb detrital-zircon geochronology to investigate sediment provenance of grains deposited during glacial and interglacial periods in the Cutler Group in the region of Moab, Utah. Our results indicate zircons dating to ca. 1400 and 1800 Ma present in both fluvial and aeolian deposits and zircons dating to ca. 400 and 600 Ma present in some of the aeolian deposits. We interpret these results to suggest the ca. 1400 and 1800 Ma populations come from the local Uncompahgre Uplift and the ca. 400 and 600 Ma populations ultimately come from Pangean mountain building and Pan-African accreted terranes, both likely in the Appalachians. Although some of the fluvial sources also contain ca. 400 and 600 Ma populations, this correlation between sediment source and mode of sediment transport may suggest that interglacial fluvial deposits have a narrow range of sediment sources while glacial aeolian deposits may have a more diverse range of sediment sources from more distal locations. These and related efforts may provide further insight into sediment sources and mode of transportation during glacial and interglacial periods during the Pennsylvanian to Permian in the Cutler Group in western United States, which could indicate that sediment provenance can vary between glacial and interglacial periods.