Sign up for eTOC alerts
Advertisement

Lyell Collection
Journal of the Geological Society
Lyell Centre  |   Lyell Collection  |   Subscriptions   |   Geological Society  |   Email alerts  |   Online bookshop  |   Help

Keywords:
Author:
Advanced search>>
This Article
Right arrow Figures Only
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow Request Permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Web of Science (9)
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by LEEDER, M. R.
Right arrow Articles by MACK, G. H.
Right arrow Search for Related Content
GeoRef
Right arrow GeoRef Citation
Journal of the Geological Society; 2001; v. 158; issue.6; p. 885-893;
DOI: 10.1144/0016-760000-198
© 2001 Geological Society of London

Regular Article

Lateral erosion (‘toe-cutting’) of alluvial fans by axial rivers: implications for basin analysis and architecture

M. R. LEEDER1 & G. H. MACK2

1 1School of Environmental Sciences, University of East Anglia, Norwich, Norfolk NR4 7TJ, UK (e-mail: M.Leeder@uea.ac.uk)
2 2Department of Geological Sciences, New Mexico State University, Las Cruces, New Mexico 88003, USA

Abstract: We document the neglected phenomenon of lateral erosion (‘toe-cutting’) of alluvial fans by non-incising axial river channels. Field examples from the Holocene of the Big Lost River basin, Idaho and the Plio-Pleistocene of the Rio Grande Rift, New Mexico help to establish architectural models with more general application to basin analysis. The process of toe-cutting can lead to complete fan destruction and may be a response to climate change, tectonic tilting, fault propagation or a combination of these variables. It gives rise to: near horizontal erosion surfaces cut in fan sediment; steep fan-margin scarps; progressive up-fan incision from the scarp by a network of channels; soil formation up-fan away from the incised channel network; a deposit of axial alluvium that overlies the erosion surface and onlaps the scarp. Once avulsion occurs to take the axial channel away from the bajada margin, distinctive ‘healing-wedges’ of fan alluvium prograde across abandoned axial river channel and floodplain deposits, gradually onlapping the eroded scarp and its upstream network of incised channels. Toe-cutting has important stratigraphic basin analysis and economic consequences: bajada deposits subject to the process exhibit appreciable extra groundwater and petroleum reservoir potential in the intercalations of more porous and permeable axial fluvial sediments.


Keywords: Idaho, Rio Grande, alluvial fans, erosion, basin analysis.




This article has been cited by other articles:


Home page
 Journal of Sedimentary ResearchHome page
G. H. Mack, M. R. Leeder, and M. Carothers-Durr
Modern Flood Deposition, Erosion, and Fan-Channel Avulsion on the Semiarid Red Canyon and Palomas Canyon Alluvial Fans in the Southern Rio Grande Rift, New Mexico, U.S.A.
Journal of Sedimentary Research, 2008; 78: 432 - 442.
[Abstract] [Full Text] [PDF]

Home page
 Geological Society, London, Special PublicationsHome page
A. M. Harvey, A. E. Mather, and M. Stokes
Alluvial fans: geomorphology, sedimentology, dynamics -- introduction. A review of alluvial-fan research
Geological Society, London, Special Publications, 2005; 251: 1 - 7.
[Abstract] [PDF]

Home page
 Geological Society, London, Special PublicationsHome page
A. Al-Farraj and A. M. Harvey
Morphometry and depositional style of Late Pleistocene alluvial fans: Wadi Al-Bih, northern UAE and Oman
Geological Society, London, Special Publications, 2005; 251: 85 - 94.
[Abstract] [PDF]

Home page
 Geological Society, London, Special PublicationsHome page
A. M. Harvey
Differential effects of base-level, tectonic setting and climatic change on Quaternary alluvial fans in the northern Great Basin, Nevada, USA
Geological Society, London, Special Publications, 2005; 251: 117 - 131.
[Abstract] [PDF]

Home page
 Geological Society of America BulletinHome page
J.L. Florsheim
Side-valley tributary fans in high-energy river floodplain environments: Sediment sources and depositional processes, Navarro River basin, California
Geological Society of America Bulletin, 2004; 116: 923 - 937.
[Abstract] [Full Text] [PDF]