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

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.

Aeolian sand dunes alongside the Yarlung River in southern Tibet: A provenance perspective

“…Secondly, it supplies well-sorted fluvial sands from the artery to feed the aeolian processes (e.g., Draut, 2012;Liu & Coulthard, 2015;Sweeney et al, 2019Sweeney et al, , 2020Wang & Ta, 2016;Yan et al, 2015). Based on the observations in this study, and reasons outlined below, we propose that the sand dunes were sourced from the fluvial deposits in the wide valleys of the Yarlung River.…”

“…, or directly acts as the provenance area for them (e.g., Draut, 2012;Liu & Coulthard, 2015;Muhs, Reynolds, Been, & Skipp, 2003;Sweeney, Fischer, Wermers, & Cowman, 2019;Sweeney, McDonald, Chabela, & Hanson, 2020;Wang & Ta, 2016;Yan, Li, Ma, Wu, & Qian, 2015). The former scenario requires a complicated multi-source pattern for aeolian sediments, whereas the latter implies a relatively simple uniform source and closer relationship between the aeolian and fluvial systems.…”

Grain Shape Evolution of Sand‐Sized Sediments During Transport From Mountains to Dune Fields

“…The sedimentological and geochemical observations demonstrate that these samples from definite fluvial environments were affected by intense eolian processes and cannot be treated as typical fluvial deposits. This type of fluvial‐eolian interaction system is ubiquitous on Earth (e.g., Good & Bryant, 1985; Liu & Coulthard, 2015; Maroulis et al., 2007; Smith & Smith, 1984; Sweeney et al., 2020), such as the William River in northwestern Saskatchewan in Canada where the sand addition from the adjacent dune field adjusted the river channel to a braided pattern (Smith & Smith, 1984). Similarly, the lower reach of the Hailar River passes through the Hailar dune field, and the Yimin River is downwind of the HSL (Figures 1c and 2).…”

Drainage Reorganization Across the Puna Plateau Margin (NW Argentina): Implications for the Preservation of Orogenic Plateaus

“…The modern divide is a small sand dune perched ∼20 m above these rivers (Figure S8, see Text S10). In regions with ephemeral drainage, aeolian activity can rework sediment and create “dune dams” that substantially modify local fluvial base levels (e.g., Sweeney et al., 2020). Salt flats adjacent to the margin on the Puna suggest that drainage is ephemeral and likely conducive to the formation of a dune dam, isolating rivers in Laguna Blanca and forcing divide migration toward the foreland (Figures 5 and S8).…”

“…Internal drainage and divide migration toward the foreland in the Quebrada del Toro and Casa Grande basins were temporary and following basin reintegration, the Puna margin jumped back toward the plateau interior. To the south, the Laguna Blanca region is likely at risk of capture and reintegration into the external drainage network given changes in boundary conditions that may affect sediment aggradation behind the dam (e.g., Sweeney et al., 2020). This may suggest that internal drainage and divide migration toward the foreland are transient anomalies that periodically interrupt generally external drainage patterns.…”