干旱区生态环境知识资源中心(Arid): Alluvial fans on volcanic islands: A morphometric perspective (Sao Vicente, Cape Verde)

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DOI	10.1016/j.geomorph.2020.107356
	Alluvial fans on volcanic islands: A morphometric perspective (Sao Vicente, Cape Verde)
	Stokes, Martin; Gomes, Alberto
通讯作者	Stokes, M
来源期刊	GEOMORPHOLOGY
ISSN	0169-555X
EISSN	1872-695X
出版年	2020
卷号	368
英文摘要	The distribution, morphology and development of volcanic island alluvial fans are investigated using Sao Vicente from the Cape Verde volcanic chain (east-central Atlantic Ocean). This is a tectonically and volcanically inactive dryland setting, comprising an eroded Plio-Pleistocene composite volcano overlying a submarine shield volcano. We mapped 228 alluvial fans, titianifing fan (F) and catchment (C) morphological properties (area [A], gradient [G], relief [R], length [L]). Fans and catchments of varying size and gradient are distributed around the island coastal margins (6%) and along interior valley sides (94%). Regression results (i.e. +ve/-ve slopes of best fit lines) conformed to broader fan research but with weak correlations, and coefficient-exponent values outside, or at the lower end of values reported from non-volcanic settings. Analysis of fan area and gradient vs catchment area regression residuals revealed fans were dominated by small-steep gradient (28%) and large-low gradient forms (39%). Fan building space is a fundamental control, specifically linked to volcano structure, but with interplay between rock strength, base level, and climate. Fans around the volcanic edifice flanks are uncommon due to steep flank slopes. Where flank margin fans occur they are typically small and steep forms due to marine erosion. Fans along flank incised valleys are common. Large low gradient fans are associated with a major volcanic riftaligned valley structure, with extensive erosion into altered and weathered edifice-core lithologies. Smallsteep gradient fans are associated with edifice flank valleys. Steeper and narrower valley forms reflect incision into stronger lithologies of the composite volcano flanks, restricting fan building space. Fans located within the volcano central depression are amongst the largest and lowest gradient types, building into the eroded and unconfined edifice core space. Coalescence, apex-toe incision, toe erosion and catchment stream channel backfilling displayed by most fans suggest landscape erosion dominates during more arid periods (e.g. interglacials), with the dryland setting generating limited sediment and insufficient flood runoff for transport and fan deposition. Fan building likely occurs during wetter periods linked to Quaternary climate variability. Quatemary eustatic variations are relevant for the volcano edifice margins where sea level changes control fan building space and erosion. (C) 2020 Elsevier B.V. All rights reserved.
英文关键词	Alluvial fans Morphomeuics Volcanic geomorphology Volcanic island Cape Verde
类型	Article
语种	英语
开放获取类型	Green Submitted
收录类别	SCI-E
WOS记录号	WOS:000571733700004
WOS关键词	TRIBUTARY-JUNCTION FANS ; HIGH ATLAS MOUNTAINS ; CANARY-ISLANDS ; GEOMORPHOLOGICAL EVOLUTION ; DEPOSITIONAL STYLE ; LATE PLEISTOCENE ; CLIMATIC-CHANGE ; LA-GOMERA ; SEDIMENTOLOGY ; CONNECTIVITY
WOS类目	Geography, Physical ; Geosciences, Multidisciplinary
WOS研究方向	Physical Geography ; Geology
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/326429
作者单位	[Stokes, Martin] Univ Plymouth, Sch Geog Earth & Environm Sci, Plymouth PL4 8AA, Devon, England; Univ Porto, Dept Geog, Via Panoram S-N, P-4159564 Porto, Portugal
推荐引用方式 GB/T 7714	Stokes, Martin,Gomes, Alberto. Alluvial fans on volcanic islands: A morphometric perspective (Sao Vicente, Cape Verde)[J],2020,368.
APA	Stokes, Martin,&Gomes, Alberto.(2020).Alluvial fans on volcanic islands: A morphometric perspective (Sao Vicente, Cape Verde).GEOMORPHOLOGY,368.
MLA	Stokes, Martin,et al."Alluvial fans on volcanic islands: A morphometric perspective (Sao Vicente, Cape Verde)".GEOMORPHOLOGY 368(2020).