东海和冲绳沉积物中自生铀蓄积过程及控制机理
Precipitation of authigenic uranium and its controlling mechanism in sediments from the East China Sea and Okinawa Trough
查看参考文献48篇
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文摘
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采用同位素稀释ICP—MS测定法，对中国东海陆架及日本冲绳海槽的6个沉积物芯中U和Th的同位素地球化学行为进行了研究，以了解氧化还原敏感元素U在近海次氧化性沉积物中的蓄积行为，并评价其在全球海洋铀平衡中的意义。东海沉积物芯中，^238U浓度及^238U／^232Th比值随深度变化不明显。但是在冲绳海槽沉积物芯中，^238U浓度及^238U／^232Th比值在沉积芯表层氧化带显示较低值，然后在次氧化层随深度增加而增加。^230Th和^232Th浓度在所有沉积物芯中基本不随深度变化。这些结果说明，冲绳沉积物中有“自生铀”的蓄积过程发生，蓄积速率约为（47±5）-（90±8）ng／（cm^2·a），与文献报道的世界其他海域次氧化性沉积区大致相当。进一步证明了U在近海次氧化性沉积区的蓄积对于全球海洋铀平衡有重要意义。“自生铀”的主要蓄积机制是海水U（Ⅵ）向沉积物迁移，在还原条件下被还原为惰性的U（Ⅳ）并被吸附在沉积物固体相上。 |
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其他语种文摘
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Concentrations of U and Th isotopes in the East China Sea and Okinawa Trough sediment cores were determined by isotope dilution inductively coupled plasma mass spectrometry （ICP-MS） to investigate the behavior of redox sensitive uranium in suboxie hemipelagie sediments and its 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 post-oxie 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 postdepositional precipitation of authigenic uranium within the suboxic Okinawa Trough sediment column. The postdepositional precipitation rates of authigenie uranium were estimated to be （47 ±5）- （90±8） ng/（cm^2·y）. These rates were comparable to those previously reported for several anoxie sediments and this removal of uranium in the oceanic budget increases the importance of the suboxie sediment sink. A mechanism controlling precipitation of uranium may be the downward diffusion of uranium U （ Ⅵ）, reduction to U （Ⅳ） and finally precipitation to the solid phase. |
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来源
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地球化学
,2006,35(3):240-248 【核心库】
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关键词
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自生铀
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氧化还原
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沉积物
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蓄积速率
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东海
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冲绳海槽
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地址
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1.
中国科学院地球化学研究所, 环境地球化学国家重点实验室, 贵州, 贵阳, 550002
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Nakaminato Laboratory for Marine Radioecology National Institute of Radiological Sciences, Japan
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语种
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中文 |
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文献类型
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研究性论文 |
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ISSN
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0379-1726 |
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学科
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地质学 |
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基金
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日本学术振兴会（JSPS）资助
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文献收藏号
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CSCD:2450532
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参考文献 共
48
共3页
|
|
1.
Langmuir D. Uranium solution-mineral equilibria at low tempera-tures with applications to sedimentary ore deposits.
Geochim Cosmochim Acta,1978,42(6,part 1):547-569
|
被引
66
次
|
|
|
|
|
2.
Cochran J K. The geochemistry of uranium and thorium in coastal marine sediments and sediments pore waters.
Geochim Cosmochim Acta,1986,50(5):663-680
|
被引
9
次
|
|
|
|
|
3.
Cochran J K. The oceanic chemistry of the uranium-and thorium-series nuclides∥.
Uranium-Series Disequilibrium:Applications to Earth,Marine,and Environmental Sciences,1992:334-395
|
被引
1
次
|
|
|
|
|
4.
Veeh H H. Deposition of uranium from the ocean.
Earth Planet Sci Lett,1967,3:145-150
|
被引
2
次
|
|
|
|
|
5.
Bonatti E. Postdepositional mobility of some transition elements phosphorus uranium and thorium in deep sea sediments.
Geochim Cosmochim Acta,1971,35(2):189-201
|
被引
3
次
|
|
|
|
|
6.
Kolodny Y. Deposition of uranium in the sediment and interstitial water of an anoxic fjord∥.
Proceedings of Symposium on Hydrogeochemistry and Biogeochemistry,1973:418-442
|
被引
1
次
|
|
|
|
|
7.
Mo T. Uranium concentrations in marine sediments.
Geochim Cosmochim Acta,1973,37(1):35-51
|
被引
9
次
|
|
|
|
|
8.
Veeh H H. Accumulation of uranium in sediments and phosphorites on the South West African shelf.
Mar Chem,1974,2(3):189-202
|
被引
1
次
|
|
|
|
|
9.
Degens E T. Uranium anomaly in Black Sea sediments.
Nature,1977,269(5629):566-569
|
被引
1
次
|
|
|
|
|
10.
Carpenter R. Mixing and cycling of uranium thorium and 210Pb in Puget Sound sediments.
Geochim Cosmochim Acta,1984,48(10):1949-1963
|
被引
1
次
|
|
|
|
|
11.
Yamada M. Postdepositional enrichment of uranium in sediment from the Bering Sea.
Mar Geol,1984,54(3/4):263-276
|
被引
1
次
|
|
|
|
|
12.
Anderson R F. Redox behavior of uranium in an anoxic marine basin.
Uranium,1987,3(2/4):145-164
|
被引
4
次
|
|
|
|
|
13.
Huh C A. Budgets and behaviors of uranium and thorium series isotopes in Santa Monica Basin sediments.
Geochim Cosmochim Acta,1987,51(6):1743-1754
|
被引
1
次
|
|
|
|
|
14.
Tsunogai S. Uranium in coastal sediments of Tokyo Bay and Funka Bay.
J Oceanogr,1990,46(5):211-218
|
被引
1
次
|
|
|
|
|
15.
Barnes C E. Geochemistry of uranium in Black Sea sediments.
Deep-Sea Res,1991,38(S2A):S1237-S125
|
被引
2
次
|
|
|
|
|
16.
Klinkhammer G P. Uranium in the oceans:Where it goes and why.
Geochim Cosmochim Acta,1991,55(7):1799-1806
|
被引
36
次
|
|
|
|
|
17.
Legeleux F. Concomitant enrichments of uranium molybdenum and arsenic in suboxic continental margin sediments.
Oceanol Acta,1994,17(4):417-429
|
被引
2
次
|
|
|
|
|
18.
Morford J L. The geochemistry of redox sensitive trace metals in sediments.
Geochim Cosmochim Acta,1999,63(11/12):1735-1750
|
被引
138
次
|
|
|
|
|
19.
Thomson J. Redox-sensitive element uptake in north-east Atlantic Ocean sediments(Benthic Boundary Layer Experiment sites).
Earth Planet Sci Lett,2001,184(2):535-547
|
被引
4
次
|
|
|
|
|
20.
Chaillou G. The distribution of Mo,U,and Cd in relation to major redox species in muddy sediments of the Bay of Biscay.
Mar Chem,2002,80(1):41-59
|
被引
26
次
|
|
|
|
|
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