| 胶州湾沉积速率:多种分析方法的对比* |
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| 引用本文： | 汪亚平,高抒.胶州湾沉积速率:多种分析方法的对比*[J].第四纪研究,2007,27(5):787-796. |
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| 作者姓名： | 汪亚平 高抒 |
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| 作者单位： | 南京大学地理与海洋科学学院海岸与海岛开发教育部重点实验室,南京,210093 |
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| 基金项目： | 国家908评价专项项目
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教育部跨世纪优秀人才培养计划
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国家自然科学基金 |
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| 摘 要： | 根据胶州湾内外海域采集的柱状岩芯样品的 210 Pb测试,结合物源分析方法,计算了1952年以来胶州湾的沉积物收支状况和胶州湾区域的平均沉积速率。结果表明,胶州湾百年尺度的沉积速率较高,达到了100mm/a量级(7.43mm/a),沉积通量为10-3g/mm2a量级(7.39×10-3g/mm2a),而胶州湾外邻近海区沉积速率略低(4.46mm/a)。这与其他学者获得的海图地形对比法的结果大致相当。与胶州湾内钻孔岩芯的14 C测年对比表明,万年尺度的沉积速率为10-1mm/a量级(0.25~0.92mm/a),比百年尺度的沉积速率约小一个数量级。分析结果表明,沉积体系的演化过程使沉积速率随时空尺度的不同而产生差异,这是导致不同分析方法所获结果之间存在复杂关系的主要因素。
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| 关 键 词： | 粒度参数 铅同位素 沉积速率 时空尺度 胶州湾 |
| 文章编号： | 1001-7410（2007）05-787-10 |
| 收稿时间： | 2007-05-10 |
| 修稿时间： | 2007-05-29 |
DEPOSITIONAL RATES ON MULTIPLE TEMPORAL AND SPATIAL SCALES IN JIAOZHOU BAY, SHANDONG PENINSULA |
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| Wang Yaping,Gao Shu.DEPOSITIONAL RATES ON MULTIPLE TEMPORAL AND SPATIAL SCALES IN JIAOZHOU BAY, SHANDONG PENINSULA[J].Quaternary Sciences,2007,27(5):787-796. |
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| Authors: | Wang Yaping Gao Shu |
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| Institution: | (The Key Laboratory of Coastal and Island Development, Ministry of Education, School of Geographic and Oceanographic Sciences, Nanjing University, Nanjing210093 |
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| Abstract: | In this study, short sediment cores were collected using a gravity corer in the Jiaozhou Bay and adjoining areas, which were divided into sub-samples in 20mm intervals. The specific radioactivity was measured in order to derive rates of sediment accumulation averaged on a 100-yr scale. Sediment dry bulk densities were measured for the calculation of net accumulation fluxes. Based on the vertical excess 210 Pb radioactivity distribution pattern, the deposition rates are estimated to be 7.43mm/a at Station J39 (in the inner bay) and 4.46mm/a at Station J94 (located in the Jiaozhou Bay and outside the embayment, respectively). In addition, the amount of sediment supply for the embayment, which includes waste particles due to human activities, the atmosphere (i.e. , aerial dusts), coastal erosion, seabed erosion, marine sediment derived from the adjoining sea, production of marine organisms, and river discharges, is estimated on the basis of the historical data. The analysis indicates that 267.6×104~272.6×104t/a and 173.0×104t/a of sediment are deposited within the embayment during \{1949~\}1979 and \{1980~\}1989, respectively. Assuming that the net deposition occurred over the entire embayment below the 0m bathymetry, the deposition rates in the embayment are 3.53~3.62mm/a for the 1949~1979 period, and 1.57mm/a for the 1980~1989 period, which have the same magnitude as the 210 Pb dating. Furthermore, these results are similar to those derived from bathymetry comparison using historical maritime charts. However, the depositional rate calculated by 14 C dating, on a ten-thousand year time scale, is significantly lower than the results obtained by 210 Pb dating, sediment budgeting analysis, and chart comparison, with the latter methods representing a centurial time scale. Such an observation indicates that the processes forming the sedimentary system result in different deposition rates on various temporal and spatial scales, which represents a major reason for the complex relationships between different data sets of deposition rate. |
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| Keywords: | grain size parameters 210^Pb isotope deposition rate temporal and spatial scales Jiaozhou Bay |
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