Preferred position model and subsurface symmetry of valleys

Abstract

Research Article| October 01, 1975 Preferred position model and subsurface symmetry of valleys ROBERT C. PALMQUIST ROBERT C. PALMQUIST 1Department of Earth Science, Iowa State University, Ames, Iowa 50010 Search for other works by this author on: GSW Google Scholar Author and Article Information ROBERT C. PALMQUIST 1Department of Earth Science, Iowa State University, Ames, Iowa 50010 Publisher: Geological Society of America First Online: 01 Jun 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 Geological Society of America GSA Bulletin (1975) 86 (10): 1392–1398. https://doi.org/10.1130/0016-7606(1975)86<1392:PPMASS>2.0.CO;2 Article history First Online: 01 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation ROBERT C. PALMQUIST; Preferred position model and subsurface symmetry of valleys. GSA Bulletin 1975;; 86 (10): 1392–1398. doi: https://doi.org/10.1130/0016-7606(1975)86<1392:PPMASS>2.0.CO;2 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGSA Bulletin Search Advanced Search Abstract The preferred position model postulates that the shape of the transverse profile of a valley is a product of the relative duration of occupation by the stream of each position across the valley. Data on distribution of streams in their valleys indicate that streams preferentially occupy the outer half of their valleys at a bend but have no preferred position within straight reaches. The symmetry variations in the transverse profiles of bedrock valleys reflect these position variations by being asymmetrical at bends and symmetrical in straight reaches. Borehole data suggest that, on the average, maximum flood scour occurs to a depth twice the bank height. These data indicate that many streams that are flowing on alluvium may scour the bedrock floor of their valleys. These conclusions indicate that some streams that flow on alluvium and appear underfit may, in fact, be fit and that some aspects of the underfit stream model are in need of re-evaluation. This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.