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DOI	10.1016/j.epsl.2019.115942
	Tracing dehydration and melting of the subducted slab with tungsten isotopes in arc lavas
	Mazza S.E.; Stracke A.; Gill J.B.; Kimura J.-I.; Kleine T.
发表日期	2020
ISSN	0012821X
卷号	530
英文摘要	Tungsten is strongly incompatible during magmatic processes and is fluid mobile in subduction zones. Here we show that W isotope fractionation in arc lavas provide a powerful new tool for tracing slab dehydration and melting in subduction zones. Geochemically well characterized, representative arc-lavas from three subduction zones were chosen for this study to evaluate W isotope fractionation under different sub-arc conditions. Arc-lavas from SW Japan are produced by subducting a young, hot slab, and lavas from the volcanic front and rear arc of the Sangihe and Izu arcs are produced during subduction of a cold slab. The heaviest W isotope compositions (δ184W∼0.06‰) are observed in fluid-rich samples from the volcanic fronts of the Sangihe and Izu arcs. With increasing distance from the volcanic front, more melt-rich samples are characterized by progressively lighter W isotope compositions. Enriched alkali basalts from SW Japan, thought to be the product of mantle melting at a slab tear, and adjacent shoshonites have the lightest W isotope compositions (δ184W∼0‰). The correlation of W isotope fractionation with various indices of fluid release (e.g., Ce/Pb, Ba/Th) suggests that the heavy W isotope signatures record fluid recycling near the volcanic front due to dehydration of the subducted slab. Upon release of the heavy W, the residual slab preferentially retains isotopically light W, which is released during subsequent melting of drier lithologies in hot subduction zones, such as SW Japan. These data suggest that W isotopes can be used as a tracer of slab dehydration, potentially helping to determine the onset of cold subduction zone magmatism and hence, modern-style plate tectonics. © 2019 The Authors
关键词	arc volcanism slab dehydration stable tungsten isotopes volatile recycling
英文关键词	Dehydration; Melting; Recycling; Volcanoes; Alkali basalt; Arc volcanism; Cold subduction; Magmatic process; Mantle melting; Shoshonites; Slab dehydration; Subduction zones; Isotopes; alkali basalt; dehydration; isotopic composition; isotopic fractionation; lava; magmatism; melting; stable isotope; subduction zone; tungsten; volcanism; Japan
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/202773
作者单位	Institut für Planetologie, University of Münster, Münster, 48149, Germany; Department of Geosciences, Smith College, Northampton, MA 01063, United States; Institut für Mineralogie, University of Münster, Münster, 48149, Germany; Department of Earth and Planetary Sciences, University of California Santa Cruz, Santa Cruz, CA 95064, United States; Japan Agency for Marine-Earth Science and Technology, Yokosuka, 237-0061, Japan
推荐引用方式 GB/T 7714	Mazza S.E.,Stracke A.,Gill J.B.,et al. Tracing dehydration and melting of the subducted slab with tungsten isotopes in arc lavas[J],2020,530.
APA	Mazza S.E.,Stracke A.,Gill J.B.,Kimura J.-I.,&Kleine T..(2020).Tracing dehydration and melting of the subducted slab with tungsten isotopes in arc lavas.Earth and Planetary Science Letters,530.
MLA	Mazza S.E.,et al."Tracing dehydration and melting of the subducted slab with tungsten isotopes in arc lavas".Earth and Planetary Science Letters 530(2020).