Physical Sciences and Mathematics Commons^™

Resolving Time-Space Histories Of Late Cenozoic Bedrock Incision Along The Upper Colorado River, Usa, Andres Aslan, Karl E. Karlstrom, Eric Kirby, Matthew T. Heizler, Darryl E. Granger, James K. Feathers, Paul R. Hanson, Shannon A. Mahan

School of Natural Resources: Faculty Publications

The upper Colorado River basin drains the western slope of the Rocky Mountains province of North America and hosts a rich record of fluvial terraces and volcanic deposits that provide an archive of bedrock river incision since the Late Miocene. Here we present new geochronology from fluvial deposits and associated volcanic units using multiple methods (luminescence, cosmogenic-burial, 40Ar/39Ar basalt and detrital sanidine, and U/Pb detrital zircon) to reconstruct a detailed record of bedrock incision in the upper Colorado River over timescales ranging from Miocene to Late Pleistocene. Late Miocene (ca. 11–8 Ma) basalt flows perched 800–1700 m above the Colorado …