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福井県大野市,前期中新世荒島岳コールドロンの地質と岩石
http://hdl.handle.net/2297/2527
http://hdl.handle.net/2297/2527e69d9148-6a44-40bb-ac1b-919105f6dc7e
| 名前 / ファイル | ライセンス | アクション |
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AN00141768-ISHIWATARI-106-2.pdf (2.2 MB)
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| Item type | 学術雑誌論文 / Journal Article(1) | |||||
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| 公開日 | 2017-10-03 | |||||
| タイトル | ||||||
| タイトル | 福井県大野市,前期中新世荒島岳コールドロンの地質と岩石 | |||||
| タイトル | ||||||
| タイトル | Geology and petrology of the Early Miocene Arashimadake cauldron in Ono City, Fukui Prefecture, central Japan | |||||
| 言語 | en | |||||
| 言語 | ||||||
| 言語 | jpn | |||||
| 資源タイプ | ||||||
| 資源タイプ識別子 | http://purl.org/coar/resource_type/c_6501 | |||||
| 資源タイプ | journal article | |||||
| 著者 |
石渡, 明
× 石渡, 明× 冨岡, 伸芳× 棚瀬, 充史× 清水, 智× 加々美, 寛雄 |
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| 提供者所属 | ||||||
| 内容記述タイプ | Other | |||||
| 内容記述 | 金沢大学大学院自然科学研究科 | |||||
| 書誌情報 |
地質学雑誌 巻 106, 号 5, p. 313-329, 発行日 2000-05-01 |
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| ISSN | ||||||
| 収録物識別子タイプ | ISSN | |||||
| 収録物識別子 | 0016-7630 | |||||
| 出版者 | ||||||
| 出版者 | 日本地質学会 | |||||
| 抄録 | ||||||
| 内容記述タイプ | Abstract | |||||
| 内容記述 | 荒島岳コールドロンは, 中央深成岩体・火山岩類・環状岩脈よりなる径7.5×5 kmの同心円状火山・深成複合岩体であり, 周囲に岩脈群を伴う.約20 Maに岩脈群と玄武岩・安山岩質成層火山体が形成され, 約18 Maに円筒状に陥没し, 環状岩脈と中央の石英モンゾ閃緑岩(SiO_2=63 wt.%)が貫入した.火山岩類および随伴する堆積岩類はコールドロンの外側へ傾斜し, 再生ドームの形成が示唆される.火山・深成岩類の多くは, 中～高カリウムのカルクアルカリ系列に属し, Sr同位体初生比(SrI)は0.705-0.707で, 日本海底や能登半島の第三紀玄武岩(≦0.704)より高い.SrIとSr含有量の関係は, アルカリ玄武岩質とソレイアイト質のマントル起源マグマの混合および地殻における泥質片麻岩など高^<87>Sr/^<86>Sr物質の同化を示唆する. The Arashimadake cauldron is a concentrically zoned volcano-plutonic complex (7.5×5 km in size) located in the southeastern margin of the Tertiary Green Tuff region along the Japan Sea coast. The cauldron is composed of a central pluton (quartz monzodiorite), surrounding andesitic and basaltic volcanic rocks, and outer ring dikes (two-pyroxene porphyrite), and is inset in the basement rocks such as Mesozoic sedimentary rocks, Mesozoic granite and Paleozoic gneiss. The volcanic rocks are composed of alternating pyroclastic rocks and lavas intercalated with minor clastic sedimentary rocks, and dip toward the rim of the cauldron. Dikes of plagioclase porphyrite and dolerite are abundant in the basement rocks surrounding the cauldron, in which those dikes are rare. The dike swarm may be feeders of the stratovolcano, which existed prior to the cauldron subsidence.K-Ar whole rock ages and geologic relationship indicate following history. The feeder dikes and stratovolcano formed around 20 Ma. Its central part subsided along a circular fracture, along which the ring dikes intruded. Resurgent dome uplift may have taken place in the subsided volcanic block in relation to the subsequent intrusion of the central pluton at about 18 Ma. The resurgent doming is characteristic of the Valles-type cauldrons, although this cauldron is smaller and lacks dacitic or rhyolitic welded tuff, which marks the collapse.The volcano-plutonic rocks mostly belong to the medium- and high-K calc-alkaline series. Their initial ^<87>Sr/^<86>Sr ratios (SrI) range from 0.705 to 0.707,which are higher and more variable than that of the Tertiary tholeiitic basalt in the Japan Sea and Noto Peninsula (<=0.704). The correlation between SrI and Sr content suggests mixing of the alkali basaltic and tholeiitic magmas of mantle origin as well as assimilation of high ^<87>Sr/^<86>Sr, low-SiO_2 crustal material such as pelitic gneiss. | |||||
| 権利 | ||||||
| 権利情報 | 日本地質学会の許諾を得て登録 | |||||
| 著者版フラグ | ||||||
| 出版タイプ | VoR | |||||
| 出版タイプResource | http://purl.org/coar/version/c_970fb48d4fbd8a85 | |||||
