Rare earth element geochemistry in the inner shelf of the East China Sea and its implication to sediment provenances
来源期刊:JOURNAL OF RARE EARTHS2011年第7期
论文作者:徐方建 李安春 李铁刚 胥可辉 陈世悦 邱隆伟 操应长
文章页码:702 - 709
摘 要:Gravity core EC2005, located in the mud wedge off the Zhejiang-Fujian coast in the inner shelf of the East China Sea (ECS), was analyzed for its lithology, grain size, rare earth elements (REE) and AMS14C dating. Results revealed high-resolution paleoenvironmental evolution and multiple switches of sediment provenances in the inner shelf of ECS. The lithology, grain size and REE concentrations of sediments varied significantly down the core. Mean grain size ranged from 8 to 121 μm, and the values of ΣREE were 152.8-227.9 μg/g. The chondrite- and shale-normalized REE patterns indicated their similarity to the terrigenous sediments in the study area. Between 17.3-12.3 ka BP the sediments in the inner shelf of ECS were mainly originated from local drainage basins. The source then gradually switched to the Yangtze River between 12.3 and 9.8 ka BP. Since about 10-9.8 ka BP, the sediments in the study area were dominantly derived from the Yangtze River. The continuous rising of sea level and formation of coastal current along the inner shelf played a key role in the switches of sediment provenances.
徐方建1,2,3,李安春1,李铁刚1,胥可辉4,陈世悦2,邱隆伟2,操应长2
1. Key Laboratory of Marine Geology and Environment, Institute of Oceanology, Chinese Academy of Sciences2. School of Geosciences, China University of Petroleum3. Key Laboratory of Shandong Province for Reservoir Geology, China University of Petroleum4. Department of Marine Science, Coastal Carolina University
摘 要:Gravity core EC2005, located in the mud wedge off the Zhejiang-Fujian coast in the inner shelf of the East China Sea (ECS), was analyzed for its lithology, grain size, rare earth elements (REE) and AMS14C dating. Results revealed high-resolution paleoenvironmental evolution and multiple switches of sediment provenances in the inner shelf of ECS. The lithology, grain size and REE concentrations of sediments varied significantly down the core. Mean grain size ranged from 8 to 121 μm, and the values of ΣREE were 152.8-227.9 μg/g. The chondrite- and shale-normalized REE patterns indicated their similarity to the terrigenous sediments in the study area. Between 17.3-12.3 ka BP the sediments in the inner shelf of ECS were mainly originated from local drainage basins. The source then gradually switched to the Yangtze River between 12.3 and 9.8 ka BP. Since about 10-9.8 ka BP, the sediments in the study area were dominantly derived from the Yangtze River. The continuous rising of sea level and formation of coastal current along the inner shelf played a key role in the switches of sediment provenances.
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