Fluvial adjustments on varied timescales in Bear Creek Arroyo, Utah, USA

Discusses fluvial processes on Late Holocene, historical and contemporary timescales in Bear Valley, Utah. Incision at Bear Creek has exposed six buried organic-rich horizons, apparently representing periods of valley-floor stability and incipient pedogenesis. These horizons are all less than 3000 yr old, and may represent periods of moister climate and associated reduction in sediment supply. The present arroyo is the first to have incised this alluvium, and was cut during the second decade of the 20th century. Analyses of records of precipitation and grazing, along with recollections of local residents suggest that incision reflects the combined impacts of changing precipitation seasonality and direct human disturbance of the natural channel. -from Author