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GEOREF RECORD

The role of eolian-fluvial interactions and dune dams in landscape change, late Pleistocene-Holocene, Mojave Desert, USA

Mark R. Sweeney, Eric V. McDonald, Lucas P. Chabela and Paul R. Hanson
The role of eolian-fluvial interactions and dune dams in landscape change, late Pleistocene-Holocene, Mojave Desert, USA
Geological Society of America Bulletin (April 2020) Pre-Issue Publication

Abstract

The formation of the Kelso Dunes in the eastern Mojave Desert, California, was a landscape-changing event triggered by an increase in sediment supply that followed the incision of Afton Canyon by the Mojave River ca. 25 ka. Eastward migration of sand dunes occurred along a well-defined eolian transport corridor. Dunes temporarily blocked washes resulting in substantial aggradation of eolian and fluvial sediments. Stratigraphic exposures reveal numerous fining-up sequences with interbedded eolian sands that provide evidence of dune dams and subsequent aggradation. Luminescence ages reveal that dune blocking and aggradation correspond to a regional pulse of alluvial fan sedimentation that occurred ca. 14-9 ka. Meanwhile, relative landscape stability occurred downstream of dune dams, resulting in the formation of a moderately developed soil on abandoned fluvial deposits. The next pulse of alluvial fan activity ca. 6-3 ka likely resulted in the breaching of the dune dams, followed by incision. Eolian system sediment state theory suggests that eolian activity in the Mojave Desert is closely tied to enhanced sediment supply, primarily related to the Mojave River-Lake Mojave system. Our data suggests that Intermittent Lake Mojave I, ca. 26-22 ka, triggered a large dune-building event that impounded massive amounts of sediment derived from alluvial fans deposited during the Pleistocene-Holocene transition. Breaching of dune dams and sediment recycling may have also increased sediment supply that contributed to late Holocene eolian activity. This profound impact on the regional geomorphology highlights the critical importance of eolian-fluvial interactions in desert environments.


ISSN: 0016-7606
EISSN: 1943-2674
Coden: BUGMAF
Serial Title: Geological Society of America Bulletin
Serial Volume: Pre-Issue Publication
Title: The role of eolian-fluvial interactions and dune dams in landscape change, late Pleistocene-Holocene, Mojave Desert, USA
Affiliation: University of South Dakota, Department of Sustainability & Environment, Vermilion, SD, United States
Published: 20200402
Text Language: English
Publisher: Geological Society of America (GSA), Boulder, CO, United States
References: 68
Accession Number: 2020-039378
Categories: Quaternary geologyGeochronology
Document Type: Serial
Bibliographic Level: Analytic
Annotation: GSDA Data Repository item 2020159
Illustration Description: illus. incl. 2 tables, sketch map
N33°30'00" - N37°15'00", W118°00'00" - W112°30'00"
Secondary Affiliation: Desert Research Institute, USA, United StatesTerracon Consultants, USA, United StatesUniversity of Nebraska-Lincoln, USA, United States
Country of Publication: United States
Secondary Affiliation: GeoRef, Copyright 2020, American Geosciences Institute. Reference includes data from GeoScienceWorld, Alexandria, VA, United States. Reference includes data supplied by the Geological Society of America, Boulder, CO, United States
Update Code: 2020
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