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Detailed Study of the Sediments Recording the Matuyama-Brunhes Geomagnetic Reversal
http://hdl.handle.net/10097/28815
http://hdl.handle.net/10097/288155ba57a9c-c9a0-410c-9354-4094257880e1
名前 / ファイル | ライセンス | アクション |
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Item type | 紀要論文 / Departmental Bulletin Paper(1) | |||||||
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公開日 | 2008-05-02 | |||||||
タイトル | ||||||||
タイトル | Detailed Study of the Sediments Recording the Matuyama-Brunhes Geomagnetic Reversal | |||||||
言語 | ||||||||
言語 | eng | |||||||
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 | departmental bulletin paper | |||||||
著者 |
Niitsuma, Nobuaki
× Niitsuma, Nobuaki
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抄録 | ||||||||
内容記述タイプ | Abstract | |||||||
内容記述 | The purpose of the present study is to find the relationship of a geomagnetic field reversal to the changes in a foraminiferal fauna and the sedimentary environments. A fossiliferous marine sedimentary section of the middle part of the Kokumoto Formation continuously exposed at Kamiyanagawa in the Boso Peninsula, Chiba Prefecture, Central Japan, was chosen for the investigation of the behaviour of the geomagnetic field during its reversal between the Matuyama and Brunhes Polarity epochs which took place around 0.69 m.y. ago. The behaviour of the geomagnetic field was established as to the inclination, declination and intensity of the Jn/J_R recorded in the sedimentary rocks. Along the same section, analyses were made on the grain-size of the sediments, oxygen isotope ratio in the planktonic and benthonic foraminiferal tests, and the faunal assemblages of the planktonic and benthonic foraminifers. The intensity of the magnetic field fluctuated with a period of approximately 6700 years and did not disappear during the reversal. The migration of the virtual magnetic north pole at the magnetic field reversal between the Matuyama and Brunhes Polarity epochs occurred roughly along the meridian of 120°E long. in the period of 4700 years. In the same duration the depth of the sea water, under which the sediments accumulated, fluctuated within the range of 200-300 m with a period of approximately 7000 years. No particular relation between the magnetic field reversal and fluctuation of the water depth was recognized. The result of paleotemperature and faunal analyses of the foraminifers showed that the magnetic field reversal at the Matuyama Brunhes Polarity Epoch boundary may have been related to the changes in the circulation pattern of the upper watermasses which caused more influx of cold water into this area in the northwestern Pacific as compared with the period before the geomagnetic polarity change. | |||||||
書誌情報 |
The science reports of the Tohoku University. Second series, Geology = 東北大学理科報告. 地質学 巻 43, 号 1, p. 1-39, 発行日 1971-10-20 |
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収録物識別子タイプ | ISSN | |||||||
収録物識別子 | 0082464X | |||||||
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収録物識別子タイプ | NCID | |||||||
収録物識別子 | AA00836349 | |||||||
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内容記述タイプ | Other | |||||||
内容記述 | application/pdf | |||||||
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出版タイプ | VoR | |||||||
出版タイプResource | http://purl.org/coar/version/c_970fb48d4fbd8a85 | |||||||
出版者 | ||||||||
出版者 | Tohoku University | |||||||
資源タイプ | ||||||||
内容記述タイプ | Other | |||||||
内容記述 | 紀要類(bulletin) | |||||||
登録日 | ||||||||
日付 | 2008-05-02 | |||||||
日付タイプ | Created | |||||||
公開日(投稿完了日) | ||||||||
日付 | 2008-05-02 | |||||||
日付タイプ | Created | |||||||
発行日 | ||||||||
日付 | 1971-10-20 | |||||||
日付タイプ | Created | |||||||
フォーマット | ||||||||
内容記述タイプ | Other | |||||||
内容記述 | 2976683 bytes | |||||||
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値 | 学外 | |||||||
更新日 | ||||||||
日付 | 2010-01-27 | |||||||
日付タイプ | Created |