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Morphodynamics of meandering streams devoid of plant life: Amargosa River, Death Valley, California

2018; Geological Society of America; Volume: 131; Issue: 5-6 Linguagem: Inglês

10.1130/b31960.1

1943-2674

Alessandro Ielpi,

Geological formations and processes

Research Article| November 28, 2018 Morphodynamics of meandering streams devoid of plant life: Amargosa River, Death Valley, California Alessandro Ielpi Alessandro Ielpi † 1Harquail School of Earth Sciences, Laurentian University, Sudbury, Ontario P3E 2C6, Canada †aielpi@laurentian.ca Search for other works by this author on: GSW Google Scholar Author and Article Information Alessandro Ielpi † 1Harquail School of Earth Sciences, Laurentian University, Sudbury, Ontario P3E 2C6, Canada †aielpi@laurentian.ca Publisher: Geological Society of America Received: 03 Nov 2017 Revision Received: 30 May 2018 Accepted: 05 Sep 2018 First Online: 28 Nov 2018 Online Issn: 1943-2674 Print Issn: 0016-7606 © 2018 Geological Society of America GSA Bulletin (2019) 131 (5-6): 782–802. https://doi.org/10.1130/B31960.1 Article history Received: 03 Nov 2017 Revision Received: 30 May 2018 Accepted: 05 Sep 2018 First Online: 28 Nov 2018 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Alessandro Ielpi; Morphodynamics of meandering streams devoid of plant life: Amargosa River, Death Valley, California. GSA Bulletin 2018;; 131 (5-6): 782–802. doi: https://doi.org/10.1130/B31960.1 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 SocietyGSA Bulletin Search Advanced Search Abstract Vegetation-free fluvial meanders are exceptional on modern Earth, and their abundance in pre-Silurian rock records is debated. Whether or not landscapes devoid of plant life could sustain sinuous planforms is nonetheless a fundamental concept that could disclose parallels with extraterrestrial sedimentary realms. The sedimentology and morphometry of an extensive (∼200 km2) unvegetated meander plain in the lower Amargosa River (Death Valley, California, USA) is investigated through remote sensing and ground checking. Results reveal sinuous bends generated by channels <2 m deep and <35 m wide that migrated laterally for as much as 200 m at rates of <1.5 m/year. The Amargosa River's ephemeral regime excludes the proposal that discharge modulation directly aids meandering. Likewise, 97.7% of ground-checked meanders are devoid of plant life, ruling out direct control by vegetation on bank stability. Cohesion offered by mud-rich banks is predominant and aided by salt cementation, which also hinders wind erosion of fines. Overall, the meanders' morphometry is in overlap with that of other sinuous (vegetated) channels, pointing to shared scalar properties. Meanders span over a continuum of a few large channels with lower aspect (width:depth) ratios and abundant smaller channels with higher aspect ratios. The migration of larger meandering channels generates distinctive scrolls and inclined accretionary packages; the migration of smaller widespread meanders only generate sub-tabular sets, producing an undistinctive depositional record. These results make the Amargosa River topical for the analogue modeling of pre-vegetation rivers, and suggest that unvegetated meanders might have been overlooked in the rock record. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.