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Precipitation of authigenic uranium in suboxic continental margin sediments from the Okinawa Trough
https://repo.qst.go.jp/records/44468
https://repo.qst.go.jp/records/44468529ed473-d6b8-4962-89e0-a0eebe2b81e1
| Item type | 学術雑誌論文 / Journal Article(1) | |||||
|---|---|---|---|---|---|---|
| 公開日 | 2006-07-13 | |||||
| タイトル | ||||||
| タイトル | Precipitation of authigenic uranium in suboxic continental margin sediments from the Okinawa Trough | |||||
| 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 | journal article | |||||
| アクセス権 | ||||||
| アクセス権 | metadata only access | |||||
| アクセス権URI | http://purl.org/coar/access_right/c_14cb | |||||
| 著者 |
Yamada, Masatoshi
× Yamada, Masatoshi× Wang, Zhong-Liang× Kato, Yoshihisa× 山田 正俊× 王 中良 |
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| 抄録 | ||||||
| 内容記述タイプ | Abstract | |||||
| 内容記述 | Concentrations of U and Th isotopes in Okinawa Trough and East China Sea sediment cores were determined by isotope dilution inductively coupled plasma mass spectrometry (ID-ICP-MS) to investigate the behavior of redox sensitive uranium in suboxic hemipelagic sediments and determine their significance in oceanic uranium balance. 238U concentrations and 238U/232Th activity ratios in the East China Sea sediments showed no remarkable variation with depth. However, 238U and 238U/232Th ratios in the Okinawa Trough sediments were low in the surface oxidizing layer but increased where the suboxic condition was encountered. The distribution profiles of 230Th and 232Th concentrations were relatively constant with depth in both the Okinawa Trough and East China Sea sediment cores. These results suggested that there has been post-depositional precipitation of authigenic uranium within the suboxic Okinawa Trough sediment column. The post-depositional precipitation rates of authigenic uranium were estimated to be 47 to 62 ng cm-2 yr-1; these rates were comparable to those previously reported for several anoxic sediments. A mechanism controlling precipitation of uranium may be the downward diffusion of uranium U(VI), reduction to U(IV) and finally precipitation onto the solid phase. The accumulation rate of uranium for the Okinawa Trough sediments was approximately 8 times higher than the world average rate reported for suboxic sediments. This removal of uranium in the oceanic budget increases the importance of the suboxic sediment sink. | |||||
| 書誌情報 |
Estuarine, Coastal and Shelf Science 巻 66, 号 3-4, p. 570-579, 発行日 2006-03 |
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| ISSN | ||||||
| 収録物識別子タイプ | ISSN | |||||
| 収録物識別子 | 0272-7714 | |||||
