摘要: |
利用a多道能谱仪对黄、渤海泥质沉积区岩芯的210Pb放射性活度进行测定,并结合历史数据,对210Pb放射性活度在岩芯中的垂向分布和现代沉积速率的平面分布进行了分析。研究区岩芯的210Pb放射性活度垂向分布表现出5种形式。从沉积速率来看,渤海东北部泥区、南黄海中部和东部泥区,以及北黄海中部泥区的沉积速率小于0.2cm/a,为低速沉积区;黄河三角洲海域和莱州湾西部的沉积速率大于lcm/a,为高速沉积区;山东半岛南部沿岸海域的沉积速率也较高;山东半岛成山头及苏北辐射沙脊群外缘海域的沉积速率为O,属于无沉积区或侵蚀区。黄、渤海泥质沉积区现代沉积速率的分布特征的解释有待于沉积动力过程的深入分析。 |
关键词: 沉积速率, 210Pb资料, 黄、渤海 |
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基金项目:国家自然科学基金资助项目,49876018号;山东省自然科学基金资助项目,H74990247号 |
附件 |
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CONTEMPORARY DEPOSITION RATES OF FINE-GRAINED SEDIMENT IN THE BOHAI AND YELLOW SEAS |
LI Feng-Ye1, GAO Shu2, JIA Jian-Jun2, ZHAO Yi-Yang1
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1.Key Laboratory of Marine Ecology and Environmental Science The Chinese Academy of Sciences;2.Ministry of Education Key Laboratory for Coast and Island Development,Nanjing University
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Abstract: |
Deposition rates were determined for short cores collected from the Bohai and Yellow Seas 0n the basis of 210Pb analysis. The profiles of 210Pb distributi0n in the cores show five distinct patterns. Differences in the profile patterns reflect spatial and temporal variations in hydrodynamic and sedimentary conditions. Low deposition rates are found in the northeastern Bohai Sea, the central an d eastern parts of the southern Yellow Sea, an d northern Yellow Sea, with a deposition rate of smaller than 0.2cm/a. High deposition rates are in the vicinity of the Yellow River delta and western Laizhou Bay, with a value of greater than 1 cm/a. Near the eastern end of the Shandong Peninsula and of the northern Jiangsu coast, the deposition rate is very small, indicating that these areas are eroding or in dynamic equilibrium . Further analysis of sediment dynamic processes is required for a better understanding of the distribution patterns of deposition rates over the Yellow and Bohai Seas. |
Key words: Deposition Rate, 210Pb dating, Bohai and Yellow Seas |