3 0 0 0 ロシア極東,ウスチベラヤ・オフィオライトの超苦鉄質岩中の角閃石
- 著者
- 町 澄秋 石渡 明 早坂 康隆 Ledneva Galina Sokolov Sergei Palandzhyan Suren Bazylev Borys 森下 知晃
- 出版者
- 一般社団法人 日本地質学会
- 雑誌
- 日本地質学会学術大会講演要旨 (ISSN:13483935)
- 巻号頁・発行日
- vol.2009, pp.523-523, 2009
1 0 0 0 OA 福井県勝山市九頭竜川上流地域の黒雲母斑晶に富む高カリウム玄武岩質転石
- 著者
- 森下 知晃 町 澄秋 ファン ミゲル グオターナ 田村 明弘
- 出版者
- 一般社団法人 日本地質学会
- 雑誌
- 地質学雑誌 (ISSN:00167630)
- 巻号頁・発行日
- vol.124, no.11, pp.941-946, 2018-11-15 (Released:2019-02-15)
- 参考文献数
- 15
Boulders of biotite-phenocryst-rich, high-K basaltic rock were discovered in the upper stream of the Kuzuryu River in Katsuyama City, Fukui Prefecture. The biotite phenocrysts are zoned, with pale brown cores and dark brown margins. Relics of mafic minerals, replaced by carbonate minerals, contain chromian spinel. Although the primary chemical composition is affected by the formation of secondary minerals such as carbonate, the SiO2 and K2O contents of the studied rock are 48-49 wt% and 3.6 wt%, respectively, which are within the chemical range of absarokite. Chondrite-normalized rare earth element and primitive-mantle-normalized trace element patterns of the studied volcanic rocks are characterized by high LREEs/HREEs, high concentrations of LILEs, and negative anomalies of HFSEs (Nb, Ti). These petrological and geochemical characteristics represent a primary composition that has never before been reported in the Hokuriku district.