The concentrations of eight heavy metals （Cu, Zn, Pb, Cd, Cr, Ni, Hg, and As） in the intertidal surface sediments from Quanzhou Bay were determined to evaluate their levels and spatial distribution due to urbanizati...The concentrations of eight heavy metals （Cu, Zn, Pb, Cd, Cr, Ni, Hg, and As） in the intertidal surface sediments from Quanzhou Bay were determined to evaluate their levels and spatial distribution due to urbanization and economic development of Quanzhou region, southeast China. The ranges of the measured concentrations in the sediments are as follows： 24.8-119.7 mg/kg for Cu, 105.5-241.9 mg/kg for Zn, 34.3-100. 9 mg/kg for Pb, 0.28-0. 89 mg/kg for Cd, 51.1-121.7 mg/kg for Cr, 16.1-45.7 mg/kg for Ni, 0.17-0.74 mg/kg for Hg, and 17.7-30.2 mg/kg for As. The overall average concentrations of above metals exceed the primary standard criteria but meet the secondary standard criteria of the Chinese National Standard of Marine Sediment Quality. Several contents of Cu and Hg exceed the secondary standard criteria at some stations. The results of geoaccumulation index （Igeo） show that Cd causes strong pollution in most of the study area. There are no significant correlations among most of these heavy metals, indicating they have different anthropogenic and natural sources. Some locations present severe pollution by heavy metals depending on the sources, of which sewage outlets, aquatic breeding, and commercial ports are the main sources of contaminants to the area.展开更多
Detailed REE and trace elements geochemical studies of the Zhoutan Group metasedimentary rocks in central Jiangxi Province, China, and rock-forming minerals such as garnet were conducted and the results showed that th...Detailed REE and trace elements geochemical studies of the Zhoutan Group metasedimentary rocks in central Jiangxi Province, China, and rock-forming minerals such as garnet were conducted and the results showed that the REEs are partly present in the rock-forming minerals and are dominantly contained in the lattice of accessory minerals. In the process of metamorphism the REEs between garnet porphyroblast and rock and the partitioning of REEs between garnet and the host rock is obviously controlled by the chemical composition of the system. The REEs compositions of metamorphic veins and their minerals display remarked lanthanide tetrad effects and the element pairs Zr-Hf, Y-Ho, Pb-Nd and U-Th have also experienced a certain degree of fractionation with respect to the metasedimentary rocks and they can be used as discriminating indicators to some extent for the occurrence of fluid processes in the process of metamorphism of the Zhoutan Group.展开更多
基金supported by the National Natural Science Foundation of China(No.40673061)the Research Program of Science and Technology of Quanzhou City Government(No.2007Z43)the Foundation of Key Laboratory of Nuclear Resources and Environment(East China Institute of Technology),Ministry of Education(No.070714).
文摘The concentrations of eight heavy metals （Cu, Zn, Pb, Cd, Cr, Ni, Hg, and As） in the intertidal surface sediments from Quanzhou Bay were determined to evaluate their levels and spatial distribution due to urbanization and economic development of Quanzhou region, southeast China. The ranges of the measured concentrations in the sediments are as follows： 24.8-119.7 mg/kg for Cu, 105.5-241.9 mg/kg for Zn, 34.3-100. 9 mg/kg for Pb, 0.28-0. 89 mg/kg for Cd, 51.1-121.7 mg/kg for Cr, 16.1-45.7 mg/kg for Ni, 0.17-0.74 mg/kg for Hg, and 17.7-30.2 mg/kg for As. The overall average concentrations of above metals exceed the primary standard criteria but meet the secondary standard criteria of the Chinese National Standard of Marine Sediment Quality. Several contents of Cu and Hg exceed the secondary standard criteria at some stations. The results of geoaccumulation index （Igeo） show that Cd causes strong pollution in most of the study area. There are no significant correlations among most of these heavy metals, indicating they have different anthropogenic and natural sources. Some locations present severe pollution by heavy metals depending on the sources, of which sewage outlets, aquatic breeding, and commercial ports are the main sources of contaminants to the area.
基金supported jointly by the National Natural Science Foundation of China (40673061)the Ministry of Science and Technology of China (95-Pre-39)the Foundation of State Key Laboratory for Mineral Deposits Research, Nanjing University
文摘Detailed REE and trace elements geochemical studies of the Zhoutan Group metasedimentary rocks in central Jiangxi Province, China, and rock-forming minerals such as garnet were conducted and the results showed that the REEs are partly present in the rock-forming minerals and are dominantly contained in the lattice of accessory minerals. In the process of metamorphism the REEs between garnet porphyroblast and rock and the partitioning of REEs between garnet and the host rock is obviously controlled by the chemical composition of the system. The REEs compositions of metamorphic veins and their minerals display remarked lanthanide tetrad effects and the element pairs Zr-Hf, Y-Ho, Pb-Nd and U-Th have also experienced a certain degree of fractionation with respect to the metasedimentary rocks and they can be used as discriminating indicators to some extent for the occurrence of fluid processes in the process of metamorphism of the Zhoutan Group.
