Physical Sciences and Mathematics Commons^™

Using Fill Terraces To Understand Incision Rates And Evolution Of The Colorado River In Eastern Grand Canyon, Arizona, J. L. Pederson, M. D. Anders, Tammy M. Rittenour, W. D. Sharp, J. C. Gosse, K. E. Karlstrom

Geosciences Faculty Publications

The incision and aggradation of the Colorado River in eastern Grand Canyon through middle to late Quaternary time can be traced in detail using well-exposed fill terraces dated by a combination of optically stimulated luminescence, uranium series, and cosmogenic nuclide dating. This fluvial history provides the best bedrock incision rate for this important landscape and highlights the complications and advantages of fill terrace records for understanding river long-profile evolution and incision. The use of fill terraces, as distinct from strath terraces, for calculating incision rates is complicated by the cyclic alluviation and incision they record. In the example of the …