DOI: 10.1016/j.earscirev.2019.103039
论文题名: Weathering indices as climate proxies. A step forward based on Congo and SW African river muds
作者: Dinis P.A. ; Garzanti E. ; Hahn A. ; Vermeesch P. ; Cabral-Pinto M.
刊名: Earth Science Reviews
ISSN: 00128252
出版年: 2020
卷: 201 语种: 英语
中文关键词: Chemical weathering
; Climate
; Congo
; Mud composition
; Rainfall proxies
; SW African margin
英文关键词: catchment
; chemical weathering
; climatology
; continental margin
; fluvial deposit
; formation mechanism
; geomorphological response
; marine sediment
; mineralogy
; mud
; rainfall
; sediment chemistry
; Congo River
英文摘要: Despite the influence of other geological and geomorphological factors, chemical weathering at the Earth's surface is strongly controlled by climate. Thus, a measure of weathering intensity determined from soils or sediments should provide information about the climatic conditions associated with their formation. Available geochemical and mineralogical data on modern fluvial and marine muds from different regions of southern Africa and its Atlantic continental margin are used to review the links between sediment composition and climatic properties together with the possible causes of variance. Although river muds may not be generated exclusively in a single sedimentary cycle and erosion and weathering processes do not necessarily take place in a spatially homogeneous way, significant relationships between mineralogical and geochemical signatures of river mud and rainfall in the corresponding catchment area were recognised. Our study shows that the composition of clay is strongly influenced by climatically-driven weathering, whilst coarser mud fractions tend to be more affected by provenance, grain size, hydraulic sorting, and recycling. In the marine environment the climatic signal may be lost even in clay, because of hydraulic fractionation, authigenic mineral growth and mixing with foreign particles. Given the ubiquitous character of fluvial muds, and the easy and non-expensive methods available for separating and analysing clay fractions, their geochemical fingerprints represent a most precious source of information concerning climate. Any geochemical parameter used as a regional proxy of climate, however, still requires that the diversity of geological, geomorphological, and biological factors that affect its value are cautiously considered. © 2019 Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/166057
Appears in Collections: 气候变化与战略
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作者单位: MARE – Marine and Environmental Sciences Centre, Department of Earth Sciences, University of Coimbra, Coimbra, 3030-790, Portugal; Laboratory for Provenance Studies, Department of Earth and Environmental Sciences, University of Milano-Bicocca, Milano, 20126, Italy; MARUM Center for Marine Environmental Sciences, University of Bremen, Bremen, Germany; University College London, London, WC1E 6BT, United Kingdom; Geobiotec Research Centre, Department of Geosciences of University of Aveiro, Aveiro, 3810-193, Portugal
Recommended Citation:
Dinis P.A.,Garzanti E.,Hahn A.,et al. Weathering indices as climate proxies. A step forward based on Congo and SW African river muds[J]. Earth Science Reviews,2020-01-01,201