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Rare earth element and Sr isotopic study of the Middle Permian limestone-dolostone sequence in Kuzuu area, central Japan : Seawater tetrad sffect and Sr isotopic signatures of seamount-type carbonate rocks
https://doi.org/10.18999/joueps.51.11
https://doi.org/10.18999/joueps.51.11441c6147-69d3-4432-b01e-b4f4bf3a286c
| 名前 / ファイル | ライセンス | アクション |
|---|---|---|
11-35.pdf (1.9 MB)
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| Item type | 紀要論文 / Departmental Bulletin Paper(1) | |||||
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| 公開日 | 2007-04-10 | |||||
| タイトル | ||||||
| タイトル | Rare earth element and Sr isotopic study of the Middle Permian limestone-dolostone sequence in Kuzuu area, central Japan : Seawater tetrad sffect and Sr isotopic signatures of seamount-type carbonate rocks | |||||
| 言語 | en | |||||
| 著者 |
Miura, Noriko
× Miura, Noriko× Asahara, Yoshihiro× Kawabe, Iwao |
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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 | The Kuzuu limestone-dolostone complex, in central Japan, is a remnant of the Middle Permian carbonate succession formed on a basaltic seamount in an open-sea realm without inputs of terrigenous materials. REE and Sr isotopic data of the carbonate rocks are clues to understanding the diagenetic process of biogenic carbonates to form crystalline carbonate minerals. The <sup>87</sup>Sr/<sup>86</sup>Sr ratios of bulk carbonate samples are 0.7073-0.7076, and their Sr isotopic stratigraphic age (260±5 Ma) coincides with their fusulinid fossil age (263±8 Ma). The carbonate rocks have much higher REE/Ca ratios than modern skeletal biogenic carbonates by factors of 10^2-10^4. Their REE/Ca ratios are about one order of magnitude higher than those of microbialite. The chondritenormalized REE patterns for the Kuzuu samples show large negative Ce anomalies, together with seawater-like tetrad effects and high Y/Ho ratios. The Ce anomalies are comparable to those of present-day ocean waters at depths of 600-800 m, except for the bottom part samples polluted with Fe(III) oxyhydroxide possibly by fluids derived from underlying basaltic volcanics. Their REE patterns normalized by Pacific seawater at a depth of 381 m exhibit smooth light REE enrichment trends similar to the experimental partition coefficients of REE between calcite-overgrowths and seawater solutions. There is no significant difference in REE and Y features between the limestone and dolostone members. The original biogenic carbonates deposited on a basaltic seamount in shallow water environment, but subsequently they were subsisted to the water depths suggested by their Ce anomalies. At the water depth, the biogenic carbonates were re-crystallized to calcite under a condition of sufficient supply of the seawater, and the seawater REE and Y were incorporated into calcite. The <sup>87</sup>Sr/<sup>86</sup>Sr ratios of dolomite, however, are slightly lower than those of coexistent calcite by 0.0002, which is a time interval of about 2 Ma from the seawater <sup>87</sup>Sr/<sup>86</sup>Sr curve for Middle to Late Permian. The dolomitization occurred almost immediately after the re-crystallization on biogenic carbonate to calcite in a moderately deep water, but did not alter the REE and Y features of limestone precursors. This is consistent with the recent diagenetic model for the carbonate sequences of Neogene atolls in the Pacific emphasizing the role of thermal convection of moderately deep water. | |||||
| 言語 | en | |||||
| 内容記述 | ||||||
| 内容記述タイプ | Other | |||||
| 内容記述 | 国立情報学研究所で電子化したコンテンツを使用している。 | |||||
| 言語 | ja | |||||
| 出版者 | ||||||
| 出版者 | Dept. of Earth and Planetary Sciences, Nagoya University | |||||
| 言語 | en | |||||
| 言語 | ||||||
| 言語 | eng | |||||
| 資源タイプ | ||||||
| 資源 | http://purl.org/coar/resource_type/c_6501 | |||||
| タイプ | departmental bulletin paper | |||||
| 出版タイプ | ||||||
| 出版タイプ | VoR | |||||
| 出版タイプResource | http://purl.org/coar/version/c_970fb48d4fbd8a85 | |||||
| ID登録 | ||||||
| ID登録 | 10.18999/joueps.51.11 | |||||
| ID登録タイプ | JaLC | |||||
| ISSN（print） | ||||||
| 収録物識別子タイプ | PISSN | |||||
| 収録物識別子 | 0919-875X | |||||
| 書誌情報 |
en : The Journal of earth and planetary sciences, Nagoya University 巻 51, p. 11-35, 発行日 2004 |
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| フォーマット | ||||||
| 値 | application/pdf | |||||
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| 値 | publisher | |||||
| URI | ||||||
| 識別子 | http://hdl.handle.net/2237/7643 | |||||
| 識別子タイプ | HDL | |||||
