气候变化领域集成服务门户(CCPortal): Fluids associated with carbonatitic magmatism: A critical review and implications for carbonatite magma ascent

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DOI	10.1016/j.earscirev.2021.103509
	Fluids associated with carbonatitic magmatism: A critical review and implications for carbonatite magma ascent
	Walter B.F.; Giebel R.J.; Steele-MacInnis M.; Marks M.A.W.; Kolb J.; Markl G.
发表日期	2021
ISSN	00128252
卷号	215
英文摘要	Carbonatites are formed from volatile-rich melts, commonly associated with a characteristic hydrothermal footprint. However, studies of their fluid inclusions are relatively scarce and heterogeneous in terms of detail and completeness of the data presented. Here, we review and discuss comprehensively the results of previous studies and derive a general model for the formation and properties of fluids associated with carbonatitic magmatism. Worldwide, four types of fluid inclusion occur in carbonatites: (type I/HS) vapour-poor H2O-NaCl fluids with up to 50 wt% salinity; (type II/HC) vapour-rich H2O-NaCl-CO2 fluids with <5 wt% salinity; (type III/DS) multi-component fluids with high salinity and without CO2; and (type IV/CDS) multi-component fluids with high salinity and high CO2. This global dataset suggests continuous fluid release from deep to shallow-level intrusions. Modelling of the liquidus surface indicates that carbonatite magmas generally exsolve a saline brine (type I/HS). This brine separates/evolves into a Na-K-sulfate-carbonate/bicarbonate-chloride brine with or without CO2 (types III/DS and IV/CDS), trapped together with low salinity CO2-rich fluids produced by immiscibility. Fluid immiscibility is related to rapid pressure release during fast, forceful and discontinuous magma ascent, which we envisage as a “pneumatic jackhammer” model for carbonatite ascent and emplacement. In this model, cyclic and progressive fluid flux via pressure build-up and subsequent catastrophic pressure release results in a self-sustaining crustal ascent of the buoyant, low-viscosity magma. This process allows for rapid and efficient magma ascent, in particular above the brittle-ductile transition zone, where pressures that prevailed during apatite crystallization have been estimated in numerous complexes. Moreover, this model provides an explanation for the apparent absence of shallow carbonatite magma chambers (in a classical sense) and identifies fenitization as a phenomenon induced by both fluids released during magma ascent and residual fluids. © 2021 Elsevier B.V.
关键词	Carbonatite-derived fluids Carbonatites Fluid inclusions High field-strength elements Hydrothermal Jackhammer process Magmatic Rapid magma ascent Rare Earth elements
英文关键词	carbon dioxide; carbonatite; crystallization; fluid inclusion; hydrothermal system; igneous geochemistry; igneous intrusion; immiscibility; magmatism
语种	英语
来源期刊	Earth Science Reviews
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/204155
作者单位	Karlsruhe Institute of Technology, Adenauerring 20b, Karlsruhe, 76131, Germany; Eberhard Karls University Tübingen, Wilhelmstr. 56, Tübingen, 72074, Germany; Technical University of Berlin, Ernst-Reuter-Platz 1, Berlin, 10587, Germany; University of the Free State, 250 Nelson-Mandela-Drive, Bloemfontein, 9300, South Africa; University of Alberta, 1-26 Earth Sciences Building, Edmonton, AB T6G2E3, Canada
推荐引用方式 GB/T 7714	Walter B.F.,Giebel R.J.,Steele-MacInnis M.,et al. Fluids associated with carbonatitic magmatism: A critical review and implications for carbonatite magma ascent[J],2021,215.
APA	Walter B.F.,Giebel R.J.,Steele-MacInnis M.,Marks M.A.W.,Kolb J.,&Markl G..(2021).Fluids associated with carbonatitic magmatism: A critical review and implications for carbonatite magma ascent.Earth Science Reviews,215.
MLA	Walter B.F.,et al."Fluids associated with carbonatitic magmatism: A critical review and implications for carbonatite magma ascent".Earth Science Reviews 215(2021).