Garnet-Pyroxenite-Derived End-Member Magma Type in Kamchatka: Evidence from Composition of Olivine and Olivine-Hosted Melt Inclusions in Holocene Rocks of Kekuknaisky Volcano
- 作者: Nekrylov N.A.1,2, Popov D.V.3, Plechov P.Y.1,4,5, Shcherbakov V.D.4, Danyushevsky L.V.6, Dirksen O.V.7
-
隶属关系:
- Fersman Mineralogical Museum
- Institute of Experimental Mineralogy
- Department of Earth Sciences
- Geological Faculty
- Vernadsky Institute of Geochemistry and Analytical Chemistry
- School of Earth Sciences
- Institute of Volcanology and Seismology, Far East Branch
- 期: 卷 26, 编号 4 (2018)
- 页面: 329-350
- 栏目: Article
- URL: https://journals.rcsi.science/0869-5911/article/view/177601
- DOI: https://doi.org/10.1134/S0869591118040057
- ID: 177601
如何引用文章
详细
Late Quaternary volcanoes of Sredinny Range (Kamchatka) attract geoscientists’ attention by their unusual geochemical features and geodynamic setting. They produced volcanic rocks that are enriched relative to N-MORB in most of incompatible trace elements (except HREE), including strong enrichment in large-ion lithophile elements, and show a negative Nb–Ta anomaly, which is typical for rocks formed in supra-subduction settings. However, modern subduction of the Pacific Plate does not reach the most part of Sredinny Range, as inferred by mapping of Wadati–Benioff zone or seismic tomography. We constrain the source of parental magmas for Sredinny Range volcanic rocks by combining major and trace element geochemical data for olivine and naturally quenched olivine-hosed melt inclusions for Holocene tephra layers of the Kekuknaisky field. Composition of the most magnesian olivine (Ni > 2000 ppm, Fe/Mn ≈ 75 at Mg# ~ 84–85 mol %) and geochemical characteristics of the most primitive melts (FC3MS = 0.61 ± 0.04 (2s)) are consistent with their derivation from a pyroxenite source, while elevated LREE/HREE ratios in lavas indicate that it contained garnet. This garnet-bearing pyroxenite likely originated from the lower crust or lithospheric mantle. Its melting could have occurred due to delamination and sinking into the hotter mantle.
关键词
作者简介
N. Nekrylov
Fersman Mineralogical Museum; Institute of Experimental Mineralogy
编辑信件的主要联系方式.
Email: nekrilov.n@gmail.com
俄罗斯联邦, Leninskii pr. 18, korp. 2, Moscow, 119071; ul. Akademika Ossipiana 4, Chernogolovka, 142432
D. Popov
Department of Earth Sciences
Email: nekrilov.n@gmail.com
瑞士, Rue des Maraîchers, 13, Geneva, 1205
P. Plechov
Fersman Mineralogical Museum; Geological Faculty; Vernadsky Institute of Geochemistry and Analytical Chemistry
Email: nekrilov.n@gmail.com
俄罗斯联邦, Leninskii pr. 18, korp. 2, Moscow, 119071; Moscow, 119899; ul. Kosygina, 19, Moscow, 119991
V. Shcherbakov
Geological Faculty
Email: nekrilov.n@gmail.com
俄罗斯联邦, Moscow, 119899
L. Danyushevsky
School of Earth Sciences
Email: nekrilov.n@gmail.com
澳大利亚, Hobart, Tasmania, 7001
O. Dirksen
Institute of Volcanology and Seismology, Far East Branch
Email: nekrilov.n@gmail.com
俄罗斯联邦, bulv. Piipa 9, Petropavlovsk-Kamchatskii, 683000
补充文件
