干旱区生态环境知识资源中心(Arid): Internal sedimentary structure of linear dunes modelled with a cellular automaton

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DOI	10.1111/sed.12767
	Internal sedimentary structure of linear dunes modelled with a cellular automaton
	Liu, Yukun; Baas, Andreas C. W.
通讯作者	Liu, YK
来源期刊	SEDIMENTOLOGY
ISSN	0037-0746
EISSN	1365-3091
出版年	2020
卷号	67 期号:7 页码:3718-3734
英文摘要	Linear dunes are the most common type of dune found on Earth and exist on several extra-terrestrial bodies, but despite this abundance their internal stratigraphy has not been commonly agreed. A cellular automaton is deployed to simulate the development of linear dunes, starting from a flat bed, under bi-modal oblique wind regimes of varying degrees of asymmetry. The internal stratigraphy of the linear dunes is monitored by keeping track of (buried) erosion surfaces, avalanche deposits and vertical accumulation, as well as the age of last subaerial exposure of the sediments. The simulations show the initial pattern-coarsening of a network of small dunes into fewer larger longitudinal ridges via bedform interactions and Y-junction dynamics. Three newly recognized types of bedform interaction are identified that relate to initial Y-junction dynamics: longitudinal crest-splitting, which creates free dune tips that can interact with adjacent dunes, and laterally oscillating interactions that lead to ephemeral Y-junctions (normal or reverse). The results show that these three bedform interactions leave no persistent signatures in the stratigraphic record. However, a further three bedform interactions involving the superposition of one dune onto another - merging, cannibalizing and repulsion (known from transverse dune field dynamics) - do leave specific evidence in the internal stratigraphy of the remaining dune, a buried interaction surface at a specific inclination. The preservation potential of this interaction surface varies between the three types. After the initial pattern-coarsening phase, the linear dunes become larger and more independent and their crest orientation follows the net resultant transport direction. The stratigraphies of mature dunes under wind regimes of differing asymmetry show that under (nearly) symmetrical winds the dune accumulates mainly vertically, with strata dipping parallel to the flanks, while under more asymmetrical wind regimes the internal stratigraphy resembles that of transverse dunes.
英文关键词	Bedform interactions pattern coarsening stratigraphy Y-junctions
类型	Article
语种	英语
开放获取类型	Other Gold, Green Published
收录类别	SCI-E
WOS记录号	WOS:000551870800001
WOS关键词	LONGITUDINAL DUNES ; FIELD PATTERN ; SAND DUNE ; BOUNDARY-CONDITIONS ; AUTOGENIC PROCESSES ; ALLOGENIC FORCINGS ; DESERT ; CHRONOLOGIES ; EVOLUTION ; DYNAMICS
WOS类目	Geology
WOS研究方向	Geology
来源机构	University of London ; University of Oxford
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/325173
作者单位	[Liu, Yukun] Univ Oxford, Sch Geog & Environm, South Parks Rd, Oxford OX1 3QY, England; [Baas, Andreas C. W.] Kings Coll London, Dept Geog, 40 Bush House,North East Wing, London WC2B 4BG, England
推荐引用方式 GB/T 7714	Liu, Yukun,Baas, Andreas C. W.. Internal sedimentary structure of linear dunes modelled with a cellular automaton[J]. University of London, University of Oxford,2020,67(7):3718-3734.
APA	Liu, Yukun,&Baas, Andreas C. W..(2020).Internal sedimentary structure of linear dunes modelled with a cellular automaton.SEDIMENTOLOGY,67(7),3718-3734.
MLA	Liu, Yukun,et al."Internal sedimentary structure of linear dunes modelled with a cellular automaton".SEDIMENTOLOGY 67.7(2020):3718-3734.