气候变化领域集成服务门户(CCPortal): Stability and migration of slab-derived carbonate-rich melts above the transition zone

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DOI	10.1016/j.epsl.2019.116000
	Stability and migration of slab-derived carbonate-rich melts above the transition zone
	Sun Y.; Hier-Majumder S.; Xu Y.; Walter M.
发表日期	2020
ISSN	0012821X
卷号	531
英文摘要	We present a theoretical model of the stability and migration of carbonate-rich melts to test whether they can explain seismic low-velocity layers (LVLs) observed above stalled slabs in several convergent tectonic settings. The LVLs, located atop the mantle transition zone, contain small (∼1 vol%) amounts of partial melt, possibly derived from melting of subducted carbonate-bearing oceanic crust. Petrological and geochemical evidence from inclusions in superdeep diamonds supports the existence of slab-derived carbonate melt, which may potentially explain the origin of the observed melt in the LVL. However, the presumptive reducing nature of the ambient mantle can be an impediment to the stability of carbonated melt. To reconcile this apparent contradiction, we test the stability and migration rates of carbonate-rich melts atop a stalled slab as a function of melt percolation, redox freezing, amount of carbon supplied by subduction, and the metallic Fe concentration in the mantle. Our results demonstrate that carbonate-rich melts in the LVL can potentially survive redox freezing over long geological time scales. We also show that the amount of subducted carbon exerts a stronger influence on the stability of carbonate melt than does the mantle redox condition. Concentration dependent melt density leads to rapid melt propagation through channels while a constant melt density causes melt to migrate as a planar front. Our calculations suggest that the LVLs can sequester significant fractions of carbon transported to the mantle by subduction. © 2019 Elsevier B.V.
关键词	carbonate-rich melts low-velocity layer reactive porous flow transition zone volatile cycle
英文关键词	Carbon; Diamond deposits; Freezing; Solvents; Stability; Concentration-dependent; Geochemical evidence; Low velocity layers; Mantle transition zone; Porous flow; Theoretical modeling; Transition zones; volatile cycle; Carbonation; carbonate; geochemistry; low velocity zone; numerical model; partial melting; petrology; porosity; slab; stability analysis; tectonic setting; transition zone
语种	英语
来源期刊	Earth and Planetary Science Letters
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/202917
作者单位	State Key Laboratory of Isotope Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, China; Department of Earth Sciences, Royal Holloway University of London, Egham, Surrey, TW20 0EX, United Kingdom; University of Chinese Academy of Sciences, Beijing, 100049, China; Geophysical Laboratory, Carnegie Institution of Washington, Washington, DC 20015, United States
推荐引用方式 GB/T 7714	Sun Y.,Hier-Majumder S.,Xu Y.,et al. Stability and migration of slab-derived carbonate-rich melts above the transition zone[J],2020,531.
APA	Sun Y.,Hier-Majumder S.,Xu Y.,&Walter M..(2020).Stability and migration of slab-derived carbonate-rich melts above the transition zone.Earth and Planetary Science Letters,531.
MLA	Sun Y.,et al."Stability and migration of slab-derived carbonate-rich melts above the transition zone".Earth and Planetary Science Letters 531(2020).