干旱区生态环境知识资源中心(Arid): The Segmented Zambezi Sedimentary System from Source to Sink: 1. Sand Petrology and Heavy Minerals

Arid

DOI	10.1086/715792
	The Segmented Zambezi Sedimentary System from Source to Sink: 1. Sand Petrology and Heavy Minerals
	Garzanti, Eduardo; Pastore, Guido; Resentini, Alberto; Vezzoli, Giovanni; Vermeesch, Pieter; Ncube, Lindani; Van Niekerk, Helena Johanna; Jouet, Gwenael; Dall'Asta, Massimo
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	JOURNAL OF GEOLOGY
ISSN	0022-1376
EISSN	1537-5269
出版年	2021-07
英文摘要	The Zambezi River rises at the center of southern Africa, flows across the low-relief Kalahari Plateau, meets Karoo basalt, plunges into Victoria Falls, follows along Karoo rifts, and pierces through Precambrian basement to eventually deliver its load onto the Mozambican passive margin. Reflecting its polyphase evolution, the river is subdivided into segments with different geological and geomorphological character, a subdivision finally fixed by man's construction of large reservoirs and faithfully testified by sharp changes in sediment composition. Pure quartzose sand recycled from Kalahari desert dunes in the uppermost tract is next progressively enriched in basaltic rock fragments and clinopyroxene. Sediment load is renewed first downstream of Lake Kariba and next downstream of Lake Cahora Bassa, documenting a stepwise decrease in quartz and durable heavy minerals. Composition becomes quartzo-feldspathic in the lower tract, where most sediment is supplied by high-grade basements rejuvenated by the southward propagation of the East African rift. Feldspar abundance in Lower Zambezi sand has no equivalent among big rivers on Earth and far exceeds that in sediments of the northern delta, shelf, and slope, revealing that provenance signals from the upper reaches have ceased to be transmitted across the routing system after closure of the big dams. This high-resolution petrologic study of Zambezi sand allows us to critically reconsider several dogmas, such as the supposed increase of mineralogical maturity during long-distance fluvial transport, and forges a key to unlock the rich information stored in sedimentary archives, with the ultimate goal to accurately reconstruct the evolution of this mighty river flowing across changing African landscapes since the late Mesozoic.
类型	Article ; Early Access
语种	英语
收录类别	SCI-E
WOS记录号	WOS:000693355300001
WOS关键词	SOUTH-CENTRAL AFRICA ; KAROO SUPERGROUP ; TECTONIC EVOLUTION ; DRAINAGE EVOLUTION ; KALAHARI CRATON ; MANTLE PLUMES ; IRUMIDE BELT ; GRAIN-SIZE ; PROVENANCE ; MOZAMBIQUE
WOS类目	Geology
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/2XILL650/363886
作者单位	[Garzanti, Eduardo; Pastore, Guido; Resentini, Alberto; Vezzoli, Giovanni] Univ Milano Bicocca, Dept Earth & Environm Sci, Lab Provenance Studies, I-20126 Milan, Italy; [Vermeesch, Pieter] UCL, London Geochronol Ctr, Dept Earth Sci, London WC1E 6BT, England; [Ncube, Lindani; Van Niekerk, Helena Johanna] Univ South Africa, Dept Environm Sci, Florida, South Africa; [Jouet, Gwenael] IFREMER Inst Francais Rech Exploitat Mer, Unite Rech Geosci Marines, CS 10070, F-29280 Plouzane, France; [Dall'Asta, Massimo] CSTJF, TOTAL Explorat & Prod, Ave Larribau, F-64018 Pau, France
推荐引用方式 GB/T 7714	Garzanti, Eduardo,Pastore, Guido,Resentini, Alberto,et al. The Segmented Zambezi Sedimentary System from Source to Sink: 1. Sand Petrology and Heavy Minerals[J]. University of London,2021.
APA	Garzanti, Eduardo.,Pastore, Guido.,Resentini, Alberto.,Vezzoli, Giovanni.,Vermeesch, Pieter.,...&Dall'Asta, Massimo.(2021).The Segmented Zambezi Sedimentary System from Source to Sink: 1. Sand Petrology and Heavy Minerals.JOURNAL OF GEOLOGY.
MLA	Garzanti, Eduardo,et al."The Segmented Zambezi Sedimentary System from Source to Sink: 1. Sand Petrology and Heavy Minerals".JOURNAL OF GEOLOGY (2021).