GEOLOGY OF ALLUVIAL FANS IN SEMIARID REGIONS

Abstract

Research Article| February 01, 1954 GEOLOGY OF ALLUVIAL FANS IN SEMIARID REGIONS ERICH BLISSENBACH ERICH BLISSENBACH LANDSHUT/BAYERN, LEBÜHLSTRASSE 2, GERMANY Search for other works by this author on: GSW Google Scholar GSA Bulletin (1954) 65 (2): 175–190. https://doi.org/10.1130/0016-7606(1954)65[175:GOAFIS]2.0.CO;2 Article history received: 29 Oct 1952 first online: 02 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation ERICH BLISSENBACH; GEOLOGY OF ALLUVIAL FANS IN SEMIARID REGIONS. GSA Bulletin 1954;; 65 (2): 175–190. doi: https://doi.org/10.1130/0016-7606(1954)65[175:GOAFIS]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 An alluvial fan is a body of detrital sediments built up at a mountain base by a mountain stream. Bold relief is essential, moderately arid to semiarid climate favorable for the development of fans. The depositing agents are sheet floods, stream floods, and streams. Compound alluvial fans result from lateral coalescence of single fans.Development of alluvial fans is affected by changes in the course of a cycle, varying base level, climatic changes, tectonic movements, and slumping of fan deposits. Telescoped or superimposed structure may be developed.Fan deposits are arkosic or graywacke. Sorting and roundness of particles range widely. The matrix is primary or secondary. In general alluvial-fan deposits are stratified. Channel cut-and-fill is pronounced. Individual strata in fans are up to 20 feet thick. Particles in stream deposits are imbricated.Talus-slope deposits at the apex of a fan and floodplain deposits at its base can be separated from those of an alluvial fan by particle sizes, angularity and orientation of fragments, sorting, and original dip of strata. Mudflow deposits in an alluvial fan indicate certain climatic conditions during its formation.Many ancient fan deposits may have escaped recognition because of the common misconception that fan deposits are necessarily unstratified, composed of angular fragments, poorly sorted, and without distinctive sedimentary structures. 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.