| 引用本文: | 吉磊,朱育新,吴瑞金,项亮,钱君龙,潘红玺.阳澄湖近代沉积物的古湖泊学研究.湖泊科学,1997,9(1):22-28. DOI:10.18307/1997.0104 |
| Ji Lei,Zhu Yuxin,Wu Ruijin,Xiang Liang,Qian Junlong,Pan Hongxi.Paleolimnology of recent sediments in yangcheng lake. J. Lake Sci.1997,9(1):22-28. DOI:10.18307/1997.0104 |
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| 阳澄湖近代沉积物的古湖泊学研究 |
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吉磊, 朱育新, 吴瑞金, 项亮, 钱君龙, 潘红玺
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中国科学院南京地理与湖泊研究所湖泊沉积与环境开放研究实验室, 南京 210008
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| 摘要: |
| 对阳澄湖两个短柱状样进行了地层年代以及各种环境指标分析.结果表明,湖底沉积物由校长期沉积间断所分割的3个岩性层组成:下部层C属再沉积的更新世晚期硬土层;中部层B为全新世沉积;上部层A为近100年以来的表层沉积.对层A的详细分析显示,本世纪以来,特别是70-80年代以来,金属元素、营养元素和色素的沉积通量明显提高,说明湖泊重金属污染和富营养化程度的不断加重. |
| 关键词: 古湖泊学 阳澄湖 沉积记录 环境演化 重金属污染 富营养化 |
| DOI：10.18307/1997.0104 |
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| 基金项目:江苏省自然科学基金BK93162201 |
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| Paleolimnology of recent sediments in yangcheng lake |
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Ji Lei, Zhu Yuxin, Wu Ruijin, Xiang Liang, Qian Junlong, Pan Hongxi
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Lake Sedimentation and Environment Lab, Nanjing Inst.of Geography and Limnology, CAS, Nanjing 210008
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| Abstract: |
| Seven cores of recent sediments were obtained in Yangcheng I.ake, among which 102cm-core YCl and 55cm-core YC3 in the western part of the lake kept undisturbed. The core profile is divided into 3 lithological beds which are separated by 2 long-term sedimentation hiatus, namely upper bed A of sapropel, middle bed B of silty clay, and lower bed C of sticky silty clay (so called "hard earth bed"). 14C, 210Pb, water content, grainsize? magnetic susceptibility, nutrient elements, metal elements (both total and liable facies), stable isotope of organic carbon and fossil pigments were analysed. Chronic stratigraphic study demonstrates that beds A, B and C belong respectively to the deposits of Late Pleistocene, Holocene and about recent 100 years. The environmental characteristics of every bed are described as follows. Bed C:Reworked fluvial sediments, in which lower values of TOC, TN, pigment content, CD/TC and heavy metals and higher values of C/N, δ13C, allogenic metals (Al, Na, Mg, Ca and Ti) manifest more intense erosion of catchment land, lower primary productivity and eu-trophic state. Bed B:Lacustrine sediments, of which every environmental proxy sits between beds A and C. Bed A:Lacustrine sediments, of which higher values of TOC, TN, pigment content, CD/TC and heary metals and lower values of C/N, δ13C and allogenic metals show enhanced primary productivity and eutrophication of the lake. Detailed analysis of the beds demonstrates slightly higher pollution coefficient of Cu, Co, Zn, Cr, Ni in 0-2cm on surficial sediments. In the accumulation rate profile, the accumulation of many heavy metals is increased gradually upwards, extensively since the 1970s. The accumulation rate of nutrient elements and pigments also indicate more intense lake eutrophication since the 1970s-1980s. |
| Key words: paleolimnology Yangcheng Lake sedimentary record environmental change heavy melal pollution eutrophication |
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