Mountains, monsoons, and megafans

Research Article| April 01, 2005 Mountains, monsoons, and megafans Andrew L. Leier; Andrew L. Leier 1Department of Geosciences, University of Arizona, Tucson, Arizona 85721, USA Search for other works by this author on: GSW Google Scholar Peter G. DeCelles; Peter G. DeCelles 1Department of Geosciences, University of Arizona, Tucson, Arizona 85721, USA Search for other works by this author on: GSW Google Scholar Jon D. Pelletier Jon D. Pelletier 1Department of Geosciences, University of Arizona, Tucson, Arizona 85721, USA Search for other works by this author on: GSW Google Scholar Author and Article Information Andrew L. Leier 1Department of Geosciences, University of Arizona, Tucson, Arizona 85721, USA Peter G. DeCelles 1Department of Geosciences, University of Arizona, Tucson, Arizona 85721, USA Jon D. Pelletier 1Department of Geosciences, University of Arizona, Tucson, Arizona 85721, USA Publisher: Geological Society of America Received: 27 Sep 2004 Revision Received: 22 Dec 2004 Accepted: 26 Dec 2004 First Online: 02 Mar 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 Geological Society of America Geology (2005) 33 (4): 289–292. https://doi.org/10.1130/G21228.1 Article history Received: 27 Sep 2004 Revision Received: 22 Dec 2004 Accepted: 26 Dec 2004 First Online: 02 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Tools Icon Tools Get Permissions Search Site Citation Andrew L. Leier, Peter G. DeCelles, Jon D. Pelletier; Mountains, monsoons, and megafans. Geology 2005;; 33 (4): 289–292. doi: https://doi.org/10.1130/G21228.1 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 SocietyGeology Search Advanced Search Abstract In certain cases, the rivers draining mountain ranges create unusually large fan-shaped bodies of sediment that are referred to as fluvial megafans. We combine information from satellite imagery, monthly discharge and precipitation records, digital elevation models, and other sources to show that the formation of fluvial megafans requires particular climatic conditions. Specifically, modern fluvial megafans in actively aggrading basins are produced by rivers that undergo moderate to extreme seasonal fluctuations in discharge that result from highly seasonal precipitation patterns. The global distribution of modern megafans is primarily restricted to 15°–35° latitude in the Northern and Southern Hemispheres, corresponding to climatic belts that fringe the tropical climatic zone. No relationship exists between megafan occurrence and drainage-basin relief or area. The tendency of rivers with large fluctuations in discharge to construct megafans is related to the instability of channels subject to such conditions. Because of the correlation between seasonal precipitation and megafan occurrence, the recognition of fluvial megafan deposits in ancient stratigraphic successions may provide critical information for paleoclimate reconstructions. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.