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[87]Sr/[86]Sr variation in north Pacific sediments: A record of the Milankovitch Cycle in the past 3 million years
http://hdl.handle.net/2237/6630
http://hdl.handle.net/2237/66308ad8feff-4028-44dc-9e77-f795448212dc
| 名前 / ファイル | ライセンス | アクション |
|---|---|---|
ot5628.pdf (1.7 MB)
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| Item type | 学位論文 / Thesis or Dissertation(1) | |||||
|---|---|---|---|---|---|---|
| 公開日 | 2006-06-26 | |||||
| タイトル | ||||||
| タイトル | [87]Sr/[86]Sr variation in north Pacific sediments: A record of the Milankovitch Cycle in the past 3 million years | |||||
| 言語 | en | |||||
| その他のタイトル | ||||||
| その他のタイトル | 北太平洋堆積物の 87Sr/86Sr 比の変動: 過去300万年間のミランコビッチサイクルの記録 | |||||
| 言語 | ja | |||||
| 著者 |
Asahara, Yoshihiro
× Asahara, Yoshihiro× 淺原, 良浩 |
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| アクセス権 | ||||||
| アクセス権 | open access | |||||
| アクセス権URI | http://purl.org/coar/access_right/c_abf2 | |||||
| 抄録 | ||||||
| 内容記述タイプ | Abstract | |||||
| 内容記述 | Temporal variations of Sr isotopic compositions in the detrital component of north Pacific sediments have been precisely examined. The Sr isotopic composition is controlled by the flux of eolian material from the Asian continent with a high 87Sr/86Sr ratio (0.724 - 0.726) relative to volcanic material with a low ratio (0.703 - 0.705) from the Izu-Ogasawara-Mariana arc and oceanic islands such as Hawaiian Islands. Assuming that the volcanic flux is constant, the temporal variation in Sr isotopic ratio reflects the amount of eolian input from the continent. The major characteristics of the temporal variations and the interpretation of them are summarized as follows: (1) The 87Sr/86Sr records show cyclic fluctuations of 400 ky and 100 ky periodicities which are associated with the eccentricity of the earth's orbit (Milankovitch Cycle). (2) Between 3 and 0.8 Ma, the 87Sr/86Sr ratio in the north central Pacific sediment increases gradually. This reflects an increased eolian input from the arid region in east Asia. The increase must be related to aridification of the Asian continent. (3) The decreased 87Sr/86Sr ratio during the past 0.8 my implies a decreased eolian input. The age of 0.8 Ma may relate to the climatic event Known as the middle Pleistocene shift. All of these phenomena reflect a fluctuation of the eolian flux corresponding to the paleoclimatic cycle of aridity in the Asian continent. The Sr isotopic composition of pelagic sediment in the north Pacific is sensitive to changes in the eolian input reflecting to the aridity of the Asian continent. keywords: 87Sr/86Sr; Pacific sediment; Milankovitch Cycle; Asian loess; paleoclimate | |||||
| 言語 | en | |||||
| 内容記述 | ||||||
| 内容記述タイプ | Other | |||||
| 内容記述 | 名古屋大学博士学位論文 学位の種類:博士(理学) (論文) 学位授与年月日:平成11年9月30日 | |||||
| 言語 | ja | |||||
| 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_db06 | |||||
| 資源タイプ | doctoral thesis | |||||
| 書誌情報 |
発行日 1999-09-30 |
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| 学位名 | ||||||
| 言語 | ja | |||||
| 学位名 | 博士(理学) | |||||
| 学位授与機関 | ||||||
| 学位授与機関識別子Scheme | kakenhi | |||||
| 学位授与機関識別子 | 13901 | |||||
| 言語 | ja | |||||
| 学位授与機関名 | 名古屋大学 | |||||
| 言語 | en | |||||
| 学位授与機関名 | Nagoya University | |||||
| 学位授与年度 | ||||||
| 値 | 1999 | |||||
| 学位授与年月日 | ||||||
| 学位授与年月日 | 1999-09-30 | |||||
| 学位授与番号 | ||||||
| 学位授与番号 | 乙第5628号 | |||||
| フォーマット | ||||||
| 値 | application/pdf | |||||
| 著者版フラグ | ||||||
| 値 | publisher | |||||
| URI | ||||||
| 識別子 | http://hdl.handle.net/2237/6630 | |||||
| 識別子タイプ | HDL | |||||
