气候变化领域集成服务门户(CCPortal): The Origin of Felsic Intrusions Within the Mantle Section of the Samail Ophiolite: Geochemical Evidence for Three Distinct Mixing and Fractionation Trends

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DOI	10.1029/2020JB020760
	The Origin of Felsic Intrusions Within the Mantle Section of the Samail Ophiolite: Geochemical Evidence for Three Distinct Mixing and Fractionation Trends
	Rioux M.; Benoit M.; Amri I.; Ceuleneer G.; Garber J.M.; Searle M.; Leal K.
发表日期	2021
ISSN	21699313
卷号	126 期号:5
英文摘要	An isotopically diverse suite of felsic dikes, sills, and plugs (εNd(t) = −7.8 to +7.8) intrude the uppermost mantle and lower crust in the Samail ophiolite in Oman and the United Arab Emirates (UAE). These features have been interpreted to represent amphibolite and metasediment melts from an underthrust sheet of oceanic lithosphere. As such, the intrusions provide a record of melting of oceanic crust and sediment at depth, with implications for mass transfer from the down-going plate in young, hot subduction settings. Several studies have used geochemical data to constrain the magmatic sources of the dikes; here we build on this previous work using integrated whole rock major element, trace element and Nd isotopic data from a more geographically extensive suite of dikes. New and existing data suggest the felsic intrusions preserved within mantle peridotites in the Oman portion of the ophiolite were generated by three distinct mixing and fractionation trends: (1) three-component mixing between sediment melt, amphibolite melt and a mantle component; (2) two component mixing between amphibolite and sediment melts, with little mantle contribution; and (3) fractional crystallization of depleted, mantle derived magmas, likely related to the ophiolite V2 volcanic series. Combined geochemical and pseudosection modeling suggest that amphibolite melting occurred at P ≤ 1.4 GPa (∼40–45 km) and T ≥ 700–750°C. Felsic intrusions in the mantle section in the UAE, including garnet-andalusite-cordierite leucogranites, follow similar mixing trends, but crystallized ∼0.9–4.0 Ma after the Oman intrusions. © 2021. American Geophysical Union. All Rights Reserved.
英文关键词	geochemistry; ophiolite; radiogenic isotope; Samail
语种	英语
来源期刊	Journal of Geophysical Research: Solid Earth
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/187161
作者单位	Department of Earth Science, University of California, Santa Barbara, Santa Barbara, CA, United States; Earth Research Institute, University of California, Santa Barbara, Santa Barbara, CA, United States; Centre National de la Recherche Scientifique, Observatoire Midi-Pyrénées, Toulouse, France; Département de Géologi, Faculté des Sciences, Université Abdelmalek Essaadi, Tétouan, Morocco; Department of Geosciences, The Pennsylvania State University, University Park, PA, United States; Department of Earth Sciences, University of Oxford, Oxford, United Kingdom
推荐引用方式 GB/T 7714	Rioux M.,Benoit M.,Amri I.,et al. The Origin of Felsic Intrusions Within the Mantle Section of the Samail Ophiolite: Geochemical Evidence for Three Distinct Mixing and Fractionation Trends[J],2021,126(5).
APA	Rioux M..,Benoit M..,Amri I..,Ceuleneer G..,Garber J.M..,...&Leal K..(2021).The Origin of Felsic Intrusions Within the Mantle Section of the Samail Ophiolite: Geochemical Evidence for Three Distinct Mixing and Fractionation Trends.Journal of Geophysical Research: Solid Earth,126(5).
MLA	Rioux M.,et al."The Origin of Felsic Intrusions Within the Mantle Section of the Samail Ophiolite: Geochemical Evidence for Three Distinct Mixing and Fractionation Trends".Journal of Geophysical Research: Solid Earth 126.5(2021).