| 摘要: |
| 根据1984年11月-1985年4月首次南大洋考察所取得的样品和资料，通过萃取液萃取并利用荧光素法测定不同形态硒，对硒在南大洋沉积物中的地球化学状态进行了研究。结果表明，西南大洋表层沉积物的总硒含量为278×10-9-1168×10-9，其与粘土粒级有较密切的关系。硒含量的地理分布表现为海湾＞半深海＞外陆架；沉积物中硒含量不同，但其地球化学形态分配比基本相同，分别为可交换态占15%，有机结合态占36%，无机盐态占4%，晶质氧化物态占9%，矿物晶格态占37%；沉积物剖面中间隙水硒的含量变化与铁一致，在铁氧化物还原带达到峰值；可交换态硒的含量随深度的增加而升高，而晶质氧化物态的含量则随深度而降低；有机质的早期成岩分解是沉积硒参与再循环的主要来源；计算得出沉积柱表面逸入上覆海水的硒通量为3.5 ng/(cm2*a)，沉积通量为13.4 ng/(cm2*a)。 |
| 关键词: 西南极海 沉积硒 地球化学 |
| DOI： |
| 分类号: |
| 基金项目:国家自然科学基金资助项目，0487013号及国家南极考察委员会八五资助项目，85-905-02号 |
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| GEOCHEMICAL STATE OF SEDIMENTARY SELENIUM IN WESTERN ANTARCTIC OCEAN |
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PAN Jian-ming,ZHANG Hai-sheng,CHENG Xian-hao,LIU Xiao-ya
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Second Institute of Oceanography, State Oceanic Administration, Hangzhou, 310012
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| Abstract: |
| The geochemical behavior and property of selenium analyzed in terms, of the different forms of selenium extracted by extracant and determinate by fluorinmentry in the sediment samples obtained during China's First Southern Ocean Expedition in Nov., 1984 to Apr., 1985. The result shows that total Se in surface sediments varies from 278×10-9 to 1168×10-9; such variations are correlated significantly with types of the clay material, with total Se being distributed in the order bay >semi-pelagic>outer continental shelf. The distribution pattern of Se forms is similar in different types of sediments; the exchangeable selenium accounts for 15%, organic 36%, inorganic 4%, crystal oxide 9% and mineral crystal 37%. The Se concentrations varies with the iron concentration in the interstitial water, reaching a maximum in the iron oxide reduction zone. Selenium content in exchangeable species increase with the depth of the sedimentary column, whilst the contents in crystal oxide decrease with the depth. The decomposition of organic matter is the main factor controlling the geochemical recycle of sedimentary selenium during early diagnoses. Selenium flux from sediment to overlying water is around 3.5 ng/(cm2*a) and sediment flux from the water column to the bed is 13.4 ng/(cm2*a). |
| Key words: Western Antarctic Ocean, Sedimentary selenium, Geochemistry |
