干旱区生态环境知识资源中心(Arid): Provenance and recycling of Sahara Desert sand

Arid

DOI	10.1016/j.earscirev.2021.103606
	Provenance and recycling of Sahara Desert sand
	Pastore, Guido; Baird, Thomas; Vermeesch, Pieter; Bristow, Charles; Resentini, Alberto; Garzanti, Eduardo
通讯作者	Garzanti, E (corresponding author), Univ Milano Bicocca, Dept Earth & Environm Sci, Lab Provenance Studies, I-20126 Milan, Italy.
来源期刊	EARTH-SCIENCE REVIEWS
ISSN	0012-8252
EISSN	1872-6828
出版年	2021
卷号	216
英文摘要	We here present the first comprehensive provenance study of the Sahara Desert using a combination of multiple provenance proxies and state-of-the-art statistical analysis. Our dataset comprises 44 aeolian-dune samples, collected across the region from 12 degrees N (Nigeria) to 34 degrees N (Tunisia) and from 33 degrees E (Egypt) to 16 degrees W (Mauritania) and characterized by bulk-petrography, heavy-mineral, and detrital-zircon U-Pb geochronology analyses. A set of statistical tools including Multidimensional Scaling, Correspondence Analysis, Individual Difference Scaling, and General Procrustes Analysis was applied to discriminate among sample groups with the purpose to reveal meaningful compositional patterns and infer sediment transport pathways on a geological scale. The overall homogenity across sand samples, however, precluded a detailed narrative. Saharan dune fields are, with a few local exceptions, composed of pure quartzose sand with very poor heavymineral suites dominated by durable zircon, tourmaline, and rutile. Some feldspars, amphibole, epidote, garnet, or staurolite occur closer to basement exposures, and carbonate grains, clinopyroxene and olivine near a basaltic field in Libya. Relatively varied compositions also characterize sand along the Nile Valley and the southern front of the Anti-Atlas fold belt in Morocco. Otherwise, from the Sahel to the Mediterranean Sea and from the Nile River to the Atlantic Ocean, sand consists nearly exclusively of quartz and durable minerals. These have been concentrated through multiple cycles of erosion, deposition, and diagenesis of Phanerozoic siliciclastic rocks during the long period of relative tectonic quiescence that followed the Neoproterozoic Pan-African orogeny, the last episode of major crustal growth in the region. The principal ultimate source of recycled sand is held to be represented by the thick blanket of quartz-rich sandstones that were deposited in the Cambro-Ordovician from the newly formed Arabian-Nubian Shield in the east to Mauritania in the west. Durability of zircon grains and their likelihood to be recycled from older sedimentary rocks argues against the assumption, too often implicitly taken for granted in provenance studies based on detrital-zircon ages, that their age distribution reflects transport pathways existing at the time of deposition rather than inheritance from multiple and remote landscapes of the past.
英文关键词	Sand petrography Heavy minerals U-Pb zircon ages Multivariate statistics Sedimentary processes Recycling Fluvial/aeolian interactions Wind-fed and river-fed sand seas Pan-African Orogeny
类型	Article
语种	英语
收录类别	SCI-E ; SSCI
WOS记录号	WOS:000641464100002
WOS关键词	INTERTROPICAL CONVERGENCE ZONE ; WEST-AFRICAN CRATON ; U-PB ; GEOCHEMICAL EVIDENCE ; DETRITAL ZIRCONS ; NORTHERN SAHARA ; OROGENIC BELTS ; HEAVY MINERALS ; MURZUQ BASIN ; YELLOW-RIVER
WOS类目	Geosciences, Multidisciplinary
WOS研究方向	Geology
来源机构	University of London
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/349975
作者单位	[Baird, Thomas; Vermeesch, Pieter; Garzanti, Eduardo] Univ Milano Bicocca, Dept Earth & Environm Sci, Lab Provenance Studies, I-20126 Milan, Italy; [Bristow, Charles] UCL, Dept Earth Sci, London Geochronol Ctr, London WC1E 6BT, England; Birkbeck Univ London, Dept Earth & Planetary Sci, Malet St, London WC1E 7HX, England
推荐引用方式 GB/T 7714	Pastore, Guido,Baird, Thomas,Vermeesch, Pieter,et al. Provenance and recycling of Sahara Desert sand[J]. University of London,2021,216.
APA	Pastore, Guido,Baird, Thomas,Vermeesch, Pieter,Bristow, Charles,Resentini, Alberto,&Garzanti, Eduardo.(2021).Provenance and recycling of Sahara Desert sand.EARTH-SCIENCE REVIEWS,216.
MLA	Pastore, Guido,et al."Provenance and recycling of Sahara Desert sand".EARTH-SCIENCE REVIEWS 216(2021).