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You Y.,Geological Survey of Guangdong Province
Jilin Daxue Xuebao (Diqiu Kexue Ban)/Journal of Jilin University (Earth Science Edition) | Year: 2015

In order to find out the distribution characteristics of organic pollutants in typical vegetable fields in Guangzhou, fifteen phthalic acid esters (PAEs), sixteen polynuclear aromatic hydrocarbons(PAHs), and nineteen organochlorine pesticides(OCPs) in twenty nine soil samples, fourteen vegetable samples, and seven water samples from six vegetable fields were detected by gas chromatography-mass spectrometry (GC-MS). Total contents of the fifteen PAE compounds (∑PAEs) range from 158.0 to 4 321.0 ng/g in all soil samples, from 1 134.0 to 48 576.0 ng/g in all vegetable samples, and from 632.0 to 14 271.0 ng/L in all water samples. For each single PAE compound, concentrations of DiBP, DBP, and DEHP are substantial, and three of them take for 97.5% to 99.1%. Total contents of the sixteen PAH compounds (∑PAHs) range from 28.48 to 1 121.96 ng/g in all soils, from 238.09 to 1 000.61 ng/g in all vegetables, and from 338.21 to 1 239.78 ng/L in all water samples. Total contents of the nineteen OCP compounds (∑OCPs) range from 0.04 to 71.28 ng/g in all soils, from 1.08 to 9.18 ng/g in all vegetable samples. The concentrations of DBP in all the soil samples exceed the control limit of soil PAEs in USA. The soils in Lingshan, Huadong, Huangpu vegetable fields are slightly contaminated by PAHs; while all the soil samples are not polluted by OCPs. ©, 2015, Jilin University Press. All right reserved. Source

Dou L.,Geological Survey of Guangdong Province | Yang G.-Y.,Guangdong Institute of Eco environmental and Soil Sciences | Yang G.-Y.,Guangdong Key Laboratory of Agro Environment Integrated Control
Huanjing Kexue/Environmental Science | Year: 2015

The contents of 17 Organochlorine pesticides (OCPs) of 605 samples collected from the surface of agriculture land from Pearl River Delta Economic Zone were determined by gas chromatography with electron capture detector (GC-ECD). The residual characteristics, sources and ecological risk of OCPs were also analyzed. The results showed that the detection rate of OCPs was 97.85%. The mean value of residue level was 20.67μg· kg-1, with the highest value of 649.33μg·kg-1. The main contaminants included DDTs, HCHs, endosulfan sulfate and methoxychlor. Compared with the soils of other cities, the levels of HCHs and DDTs in the studied area were arranged from low to middle levels. The OCPs were obviously regionally distributed. High content areas were mainly distributed in the central area with dense population, intense industrial and agricultural activities. The residue levels in different types of lands were significantly different: the arable land>garden land>woodland. Especially, the residue level was the highest in the vegetable land. Source analysis indicated that the HCHs might come from the use of lindane. DDTs in soil mainly came from early residues, but the dicofol might be the important source in partial area. Comparing the contents of HCHs and DDTs with our National Standard (GB 15618-2008), the qualified rates of the first and second standard of HCHs were 97.5% and 100%, respectively, and the DDTs were 95.5% and 97.7%, respectively. According to the risk assessment, DDTs may still have some potential ecological impact on the studied area. ©, 2015, Huanjing Kexue/Environmental Science. All right reserved. Source

Dong H.-G.,Wuhan Institute of Geology and Mineral Resources | Huang C.-S.,Wuhan Institute of Geology and Mineral Resources | Chen W.,Wuhan Institute of Geology and Mineral Resources | Zhang H.-X.,Wuhan Institute of Geology and Mineral Resources | And 2 more authors.
Geology in China | Year: 2012

The Pearl River Delta Economic Zone, which lies in the central south of Guangdong Province and borders on the South China Sea, has experienced strong land-sea interaction and active neotectonism as well as obvious erosion,and is characterized by wide distribution of Quaternary sediments and a variety of landform types. It is a transitional zone and a sensitive belt of geological environment. The unique geological environment must have caused corresponding geological environment problems. Based on current survey and past research findings, the authors have summarized the main factors controlling geological environment, such as geomorpohologic landscape, neotectonism, change of sea surface and evolution of Quaternary sedimentation. The mainly problems of geological environment and calamity geology in the Pearl River Delta are put forward, which include earthquake and crustal stability,surface deformation in soft soil area,karst collapse,and coast anomalous change with the superimposition of sea level rising. From the angle of geological environment, some corresponding countermeasures are proposed. Source

Dou L.,Geological Survey of Guangdong Province | Shen S.-Z.,Beijing Normal University | Du H.-Y.,Geological Survey of Guangdong Province
Chinese Journal of Geochemistry | Year: 2015

Dongguan City, located in the Pearl River Delta economic zone of China, is famous for its rapid developing township-enterprises in the past 30 years. A total of 759 composite soil samples, including 606 surface soil samples and 153 deep soil samples, have been collected in the city. These samples have been analyzed for 13 elements (Al, As, Cu, Cd, Co, Cr, Fe, Hg, Mn, Ni, Pb, Si, and Zn) and other parameters (pH values and organic matter) to evaluate the influence of anthropic activities on the soil environmental quality and to identify the spatial distribution of heavy metals and their possible sources. The results indicate that the average concentrations of heavy metals in soil were significantly lower than the threshold of the second grade of the Soil Environment Quality Standard in China (GB15618-1995) and the soil environmental quality in this area is comparatively good. But in comparison with local soil geochemical baseline values, As, Cd, Cu, Hg, Pb, and Zn have accumulated remarkably. Specifically, the average concentrations of As, Cd, Cu, and Hg in the small part samples of the west plain and central areas are higher than the national second-grade quality standard, indicating some level of contamination. Multivariate and geostatistical methods have been applied to differentiate the influences of natural processes and human activities on the concentration of heavy metals in surface soils in the study area. Cluster and factor analyses result in the grouping of Al, As, Cr, Cu, Fe, Ni, and Si into factor F1; Co, Mn, Pb, and Zn into F2; and Cd and Hg into F3. The spatial pattern of the three factors may be well demonstrated by geostatistical analysis. It is shown that the first factor could be considered as a natural source controlled by parent material. The second factor could be referred to as “industrial and traffic pollution sources”. The source of the third factor is mainly controlled by long-term anthropic activities, including agricultural activities, fossil fuel consumption, and atmospheric deposition. © 2015, Science Press, Institute of Geochemistry, CAS and Springer-Verlag Berlin Heidelberg. Source

Zheng W.,China University of Geosciences | Zhao H.-J.,Chinese Academy of Geological Sciences | Chen M.-H.,Chinese Academy of Geological Sciences | Xu L.-G.,Chinese Academy of Geological Sciences | And 4 more authors.
Kuangwu Yanshi/ Journal of Mineralogy and Petrology | Year: 2013

Six molybdenite samples are selected from the Yingwuling copper polymetallic deposit to perform the Re-Os dating. It yielded weighted average model ages of 82. 96 Ma to 84. 75 Ma, with a narrow range variation. It was showed that the Re-Os dating of one sample collected from skarn-type ore yielded a model age of 82. 96 Ma±1.2 Ma,and five molybdenite samples collected from quartz-vein-type ore yielded model ages ranging from 83. 78 Ma to 84. 75 Ma, with an average of 84.08 Ma± 0.54 Ma,and give an isochron age of 83. 0 Ma±1.7 Ma. Evidently, model ages are compatible with isochron age in the error within the allowable range,so it constrains the absolute age of Yingwuling copper polymetallic deposit in 82. 96 Mã84. 75 Ma,namely,the Late Cretaceous is the main time for the formation of ore. The molybdenites from Yingwuling copper polymetallic deposit have a low content of Re,indicating a crustal source for ore-forming materials. It was considered that the deposit formed in the Late Yanshanian lithospheric extensional and thinning environment. Source

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