Rapid incision of the Colorado River in Glen Canyon - insights from channel profiles, local incision rates, and modeling of lithologic controls

Auteur(s) et Affiliation(s)

COOK, K.L.

Dep. of Earth, Atmospheric, and Planetary Sciences, Massachusetts Inst. of Technology, Cambridge, Etats-Unis

WHIPPLE, K.X.

School of Earth and Space Exploration, Arizona State Univ., Tempe, Etats-Unis

HEIMSATH, A.M.

School of Earth and Space Exploration, Arizona State Univ., Tempe, Etats-Unis

HANKS, T.C.

US Geological Survey, Menlo Park, California, Etats-Unis

Description :
The AA. use longitudinal profiles of the Colorado and tributaries between Marble Canyon and Cataract Canyon to investigate the incision history of the Colorado. They find that almost all of the tributaries in this region steepen as they enter the Colorado River. The consistent presence of oversteepened reaches with similar elevation drops in the lower section of these channels, and their coincidence within a corridor of high local relief along the Colorado, suggest that the tributaries are steepening in response to an episode of increased incision rate on the mainstem. This analysis makes testable predictions about spatial variations in incision rates. The AA. also present cosmogenic nuclide data from the Henry Mountains of southern Utah. Numerical modeling of detachment-limited bedrock incision suggests that this incision pulse is likely related to the upstream-dipping lithologic boundary at the northern edge of the Kaibab upwarp.

Type de document :
Article de périodique

Source :
Earth surface processes and landforms, issn : 0197-9337, 2009, vol. 34, n°. 7, p. 994-1010, nombre de pages : 17, Références bibliographiques : 1,5 p.

Date :
2009

Editeur :
Pays édition : Royaume-Uni, Chichester, Wiley

Langue :
Anglais