Development of longitudinal dunes under Pangaean atmospheric circulation

Shozaki, Hiroki; Hasegawa, Hitoshi

doi:10.5194/cp-18-1529-2022

Cited by 5 publications

(2 citation statements)

References 63 publications

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“…Overall, these autogenic and allogenic controls relate to conditions expected to be universal for aeolian systems. For instance, several ancient aeolian systems register regional changes in wind direction (Parrish & Peterson, 1988; Peterson, 1988; Giannini et al ., 2004; Mescolotti et al ., 2019; Shozaki & Hasegawa, 2021; Yu et al ., 2021a,b), modern deserts display changes in provenance along their margins (Garzanti et al ., 2012; Rittner et al ., 2016; Pastore et al ., 2021), as well as aeolian abrasion that is shown to be observed in both the field (Crouvi et al ., 2008, 2010) and experiments (Kuenen, 1960; Bullard et al ., 2004; Durian et al ., 2006, 2007; Roth et al ., 2011). Thus, the provenance, aeolian abrasion, and mixture of these process recorded in the Botucatu palaeodesert are potentially important in aeolian desert systems in general.…”

Section: Discussionmentioning

confidence: 99%

Controls on grain‐size distribution in an ancient sand sea

et al. 2023

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Grain size distribution in deserts is driven by a combination of autogenic controls such as grain abrasion and sorting due to wind transport and allogenic controls such as provenance and spatial changes in wind-direction. Downwind grain-size trends in present day sand seas display contrasting results. For example, the Namib and Hexi Corridor sand seas show broad downwind fining and sorting trends which are not present in the Ténére, Australian and Sinai sand seas. This study examines the grain size distribution along the margins of the Cretaceous Botucatu paleodesert across an area of >1,000,000 km 2 to determine the relative importance of autogenic and allogenic controls on sand distribution. A comparison between the spatial distribution of grain size metrics with detrital zircon geochronology as a provenance test, paleowind patterns as a wind-regime test and 3 transects along the basin paleomargins as a downwind abrasion test, are used to quantify the main controls on Botucatu paleodesert grain-size distribution. Grain size dispersion shows an E to W fining pattern, which agrees with provenance control -in contrast to a N-S trend expected for the predominant wind-regime control. In the NE region there is good evidence for downwind fining due to aeolian abrasionof about 0.4 μm by km, indicating that whilst downwind fining due to abrasion does occur, but that it is limited by the rounded nature of available sands for Botucatu desert and possibly by mix of different provenance sources. The results suggests that the provenance of the available sand is the primary control on the grain-size distribution in the Botucatu sand sea and potentially in most large-scale dune fields.

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Section: Discussionmentioning

confidence: 99%

Controls on grain‐size distribution in an ancient sand sea

et al. 2023

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“…This property helps to explain the richness of shapes and scales observed, and makes dunes witnesses of past winds and conditions. On Earth, dunes are used to study paleoclimates and test global circulation models [1,2,3]. The sedimentary structure, shape and orientation of dunes are also used to constrain climate models and the history of celestial bodies such as Venus, Mars and Titan, for which little climate data are available but where dunes are observed [4,5,6,7,8,9,10,11,12,13,14].…”

Section: Introduction -Previous Classifications and Aimsmentioning

confidence: 99%

Complementary classifications of aeolian dunes based on morphology, dynamics, and fluid mechanics

Courrech du Pont,

Rubin,

Narteau

et al. 2024

Preprint

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Dunes form where winds blow over a bed of mobile sediment grains – conditions that are common in our solar system. On Earth, dunes abound in arid continental interiors and along sandy coastlines. Dune fields have also been recognized on other planetary bodies, including Venus, Mars, Saturn’s moon Titan, and Pluto. Despite the relatively basic conditions required for their formation, dunes adopt a rich diversity of shapes, sizes, and behaviors in response to their boundary conditions and other environmental forcings. Thus, people around the globe and over centuries have developed a rich vocabulary to describe dunes and their complexity. In addition, many studies have been devoted to link dune shape to environmental forcings, usually by means of correlations. As a result, existing dune nomenclature often includes redundant terms with differing definitions across scientific communities. Although a worthy first step, correlation-based classifications can be misleading if not based on an underlying mechanics and if dune morphogenetic classes are not uniquely defined. Here, we synthesize existing dune terminology and put the last two decades of research on dune morphodynamics in perspective in proposing three simplified dune classification schemes based on the state-of-the-art understanding of dune morphology, morphogenetic processes and coupling between sand bed, fluid flow and sediment transport. Together, these classifications provide a unified framework for geomorphologists, sedimentologists, geographers, physicists, and others to describe windblown sand dunes on Earth and beyond through their shape, dynamics, and size as a response to winds and boundary conditions.

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