| 引用本文: | 于志同,王秀君,赵成义,兰海燕.博斯腾湖表层沉积物无机碳及其稳定同位素空间异质性.湖泊科学,2015,27(2):250-257. DOI:10.18307/2015.0208 |
| YU Zhitong,WANG Xiujun,ZHAO Chengyi,LAN Haiyan.Spatial variations of inorganic carbon and isotopes in the surface sediment of the Lake Bosten. J. Lake Sci.2015,27(2):250-257. DOI:10.18307/2015.0208 |
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| 博斯腾湖表层沉积物无机碳及其稳定同位素空间异质性 |
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于志同1,2,3, 王秀君1,4, 赵成义1, 兰海燕2
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1.中国科学院新疆生态与地理研究所, 荒漠与绿洲生态国家重点实验室, 乌鲁木齐 830011;2.新疆大学资源与环境科学学院, 乌鲁木齐 830046;3.中国科学院大学, 北京 100049;4.马里兰大学地球科学交叉学科中心, 美国马里兰州 20740
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| 摘要: |
| 2012年8月,在新疆博斯腾湖13个站点进行表层沉积物采集,分析无机碳及其碳、氧稳定同位素的含量和空间分布特征,探讨该湖表层沉积物无机碳(TIC)的空间变化影响因素.结果表明:2012年,博斯腾湖表层沉积物TIC含量平均值为5.5%,变幅为3.8%~9.8%,而δ13Ccarb和δ18Ocarb平均值分别为0.71‰和-4.4‰,范围为-0.23‰~2.27‰和-5.53‰~-2.55‰.从空间来看,湖泊北岸TIC值明显高于南岸,最高值出现在湖泊西北部的黄水沟水域,而河口区和湖心区最低.总体上,博斯腾湖表层沉积物TIC主要是湖泊自生的,其空间分布主要受开都河、黄水沟等入湖河水的影响,导致水体矿化度和营养盐的空间差异,进而影响了碳酸盐的析出与沉淀.另外,湖泊局部的水动力条件也影响TIC的保存与分布.δ13Ccarb与δ18Ocarb的极显著正相关说明近几年博斯腾湖封闭程度较好,尤其是东部大湖区,属于封闭环境碳酸盐沉淀. |
| 关键词: 博斯腾湖 无机碳 空间变化 表层沉积物 |
| DOI：10.18307/2015.0208 |
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| 基金项目:国家自然科学基金项目(41101100)、中国科学院战略性先导科技碳专项(XDA05020202)和中德合作项目(GZ867)联合资助. |
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| Spatial variations of inorganic carbon and isotopes in the surface sediment of the Lake Bosten |
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YU Zhitong1,2,3, WANG Xiujun1,4, ZHAO Chengyi1, LAN Haiyan2
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1.State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi 830011, P. R. China;2.College of Resources and Environmental Sciences, Xinjiang University, Urumqi 830046, P. R. China;3.University of Chinese Academy of Sciences, Beijing 100049, P. R. China;4.Earth System Science Interdisciplinary Center, University of Maryland, Maryland 20740, USA
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| Abstract: |
| In this paper, we evaluated the sources and spatial variations of inorganic carbon in the surface sediments of Lake Bosten and explored the influencing factors.The samples were collected at 13 sites in the main section of the Lake Bosten in August, 2012, using a Kajak gravity corer.The sampling sites covered most parts of the lake, with water depths from 3m to 14m.Total inorganic carbon(TIC), stable carbon and oxygen isotopic composition in carbonate(δ13Ccarb & δ18Ocarb) were analyzed.Our data showed that the contents of TIC ranged from 3.8% to 9.8%, with an average of 5.5%.The analysis of the stable carbon and oxygen isotope composition of carbonate from the surface sediments showed the values of δ13Ccarb and δ18Ocarb were from -0.23‰ to 2.27‰(0.71‰) and from -5.53‰ to -2.55‰(-4.4‰), respectively.According to the concentrations of lake water anion and cation and pH values, we calculated the saturation coefficient index with respect to calcite(IAP/Ksp), and the results showed that the lake water in Lake Bosten had a necessary condition of authigenic carbonate precipitation.Judging from the spatial distribution, TIC showed much higher values in the north area than in the south area, with the highest content occurring near the Huangshui area and lowest in the south estuary and central lake section.In general, the spatial distribution of TIC in the surface sediments of Lake Bosten was mainly under the influence of inflows by Kaidu River and Huangshui River, which resulted in the spatial differences of lake water salinity and nutrients, thereby affecting the precipitation and distribution of carbonate.In addition, lake hydrodynamic conditions might also affect the preservation and distribution of inorganic carbon in local environment of the Lake Bosten, especially in the mid-west lake section.The δ13Ccarb and δ18Ocarb values were significantly different in different lake environment, with the most negative values near the Kaidu River estuary and the east-deep water area.According to the correlation between δ13Ccarb and δ18Ocarb values, we inferred that the sedimentary carbonate was mainly formed in a closed basin. |
| Key words: Lake Bosten inorganic carbon spatial variation surface sediment |
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