In October 2012,an evaluation using potential ecological hazard risk index was carried out on soil heavy metal pollution around AgSb deposit tailing areas in northeastern Guangdong. Results indicate that( i) soil heav...In October 2012,an evaluation using potential ecological hazard risk index was carried out on soil heavy metal pollution around AgSb deposit tailing areas in northeastern Guangdong. Results indicate that( i) soil heavy metal pollution is mainly Cd-Ni compound pollution,including Cd content 0. 31- 2. 66 mg / kg( average content is 1. 11 mg / kg),the situation of exceeding standard is serious( the rate of exceeding standard is 100%); the total potential ecological hazard risk index( RI) is between 50 and 300,and it is moderate pollution;( ii) in soil heavy metal content,only Ni and Cu are positively correlated. Since there is certain degree of Ni pollution in this deposit,the synergetic effect of Cu and Ni may deteriorate Ni pollution.展开更多
A coupled approach based on grain size and geochemical elements is used to trace the provenance of surface sediments and to confirm the distribution patterns of grain size and elements on the continental shelf off wes...A coupled approach based on grain size and geochemical elements is used to trace the provenance of surface sediments and to confirm the distribution patterns of grain size and elements on the continental shelf off western Guangdong Province and northeastern Hainan Island. The mean grain size ranges from 0.05 φ to 7.28 φ with a mean value of 5.60 φ. The average concentra- tions of major elements descend in the order of SiO2 > Al2O3 > CaO > Fe2O3 > K2O > MgO > Na2O > TiO2 > P2O5 > MnO, while those of trace elements exhibit a descending order of Sr > Rb > Zn > V > Cr > Pb > Ni > Cu > As > Cd. On the basis of the distribution patterns of elements and results of statistical analysis, the study area is classified into three zones. Zone I locates on the continental shelf off western Guangdong Province, and the sediments are mainly from Pearl River, Taiwan Residents rivers, and small rivers nearby. Zone II locates in the eastern exit of Qiongzhou Strait and the coastal area off Leizhou Peninsula, and the sediments are mainly from the ero- sion products of Qiongzhou Strait and Hainan Island. Zone III locates off the eastern Hainan Island and the continental shelf deeper than 50 m isobaths, and the sediments are mainly from Hainan Island and coral reef. The influence from open water should also be considered. Results indicate that the grain size is the main controlling factor for major and trace element contents and that anthropo- genic impact and biological activity also play an important role in the distribution of these elements.展开更多
The paleoenvironment indicated by the geochronology,major oxides——SiO2,Al2O3 and TOFE(Fe2O3 + FeO),and CIA(Chemical Index of Alteration) value of the red earth and brown-yellow silt primarily characterized by the Li...The paleoenvironment indicated by the geochronology,major oxides——SiO2,Al2O3 and TOFE(Fe2O3 + FeO),and CIA(Chemical Index of Alteration) value of the red earth and brown-yellow silt primarily characterized by the Linjiang stratigraphic section,based on the geological investigation of Late Quaternary along the river banks of northeastern part of China's Guangdong Province,south to the Nanling Mountains,allow us to hypothesize that the red earth on the first terrace in northeastern part of Guangdong belongs to reticulated red clay developed in a hot-wet environment of the last interglacial period(132―73 ka BP),similar to the monsoon environment in the northern margin of modern tropical zone,while the overlying brown-yellow silt layer mainly accumulated in a monsoon environment of warm temperate zone in the last glacial period(73―11 ka BP),with the aeolian sand LJ3 representing an extreme period of worsening climate.Such a hypothesis corresponds well with predecessors' research on the paleoenvironment indicated by abundant fossils in both south and east to the Nanling Mountains.Hence,it follows that the bioclimatic zone did experience a large and rapid vicissitude in northeastern part of China's Guangdong Province,and even in the full extent of the region south to the Nanling Mountains from the last interglacial period to the last glacial period,with the red earth being replaced by the brown-yellow silty sediment,and even maybe with the Ailuropoda-Stegodon Fauna being replaced by the Penghu Fauna.This study may provide an important geological demonstration for the environmental response to global change in China's low latitudes on a 10 ka scale.展开更多
基金Supported by Science and Technology Planning Project of Guangdong Province(2012A030700006)Key Sci-tech Innovation Project for Institutions of Higher Education in Guangdong Province(cxzd 1132)Joint Natural Science Project of Meizhou and Jiaying University(2011KJM08)
文摘In October 2012,an evaluation using potential ecological hazard risk index was carried out on soil heavy metal pollution around AgSb deposit tailing areas in northeastern Guangdong. Results indicate that( i) soil heavy metal pollution is mainly Cd-Ni compound pollution,including Cd content 0. 31- 2. 66 mg / kg( average content is 1. 11 mg / kg),the situation of exceeding standard is serious( the rate of exceeding standard is 100%); the total potential ecological hazard risk index( RI) is between 50 and 300,and it is moderate pollution;( ii) in soil heavy metal content,only Ni and Cu are positively correlated. Since there is certain degree of Ni pollution in this deposit,the synergetic effect of Cu and Ni may deteriorate Ni pollution.
基金supported by the National Natural Science Foundation of China (Nos. 41476047, 41106045, 41506064 and 41427803)the National Programme on Global Change and Air-Sea Interaction (Nos. GASIGEOGE-03 and GASI-04-01-02)
文摘A coupled approach based on grain size and geochemical elements is used to trace the provenance of surface sediments and to confirm the distribution patterns of grain size and elements on the continental shelf off western Guangdong Province and northeastern Hainan Island. The mean grain size ranges from 0.05 φ to 7.28 φ with a mean value of 5.60 φ. The average concentra- tions of major elements descend in the order of SiO2 > Al2O3 > CaO > Fe2O3 > K2O > MgO > Na2O > TiO2 > P2O5 > MnO, while those of trace elements exhibit a descending order of Sr > Rb > Zn > V > Cr > Pb > Ni > Cu > As > Cd. On the basis of the distribution patterns of elements and results of statistical analysis, the study area is classified into three zones. Zone I locates on the continental shelf off western Guangdong Province, and the sediments are mainly from Pearl River, Taiwan Residents rivers, and small rivers nearby. Zone II locates in the eastern exit of Qiongzhou Strait and the coastal area off Leizhou Peninsula, and the sediments are mainly from the ero- sion products of Qiongzhou Strait and Hainan Island. Zone III locates off the eastern Hainan Island and the continental shelf deeper than 50 m isobaths, and the sediments are mainly from Hainan Island and coral reef. The influence from open water should also be considered. Results indicate that the grain size is the main controlling factor for major and trace element contents and that anthropo- genic impact and biological activity also play an important role in the distribution of these elements.
基金Supported by National Natural Science Foundation of China (Grant No.40471139)National Basic Research Program of China (Grant No.2004CB720206)+1 种基金the Special Fund of Scientific Research for Doctoral Subjects of Chinese Universities (Grant No. 20070574005)the RGC Grant of the HKSAR (HKU7243/04H)
文摘The paleoenvironment indicated by the geochronology,major oxides——SiO2,Al2O3 and TOFE(Fe2O3 + FeO),and CIA(Chemical Index of Alteration) value of the red earth and brown-yellow silt primarily characterized by the Linjiang stratigraphic section,based on the geological investigation of Late Quaternary along the river banks of northeastern part of China's Guangdong Province,south to the Nanling Mountains,allow us to hypothesize that the red earth on the first terrace in northeastern part of Guangdong belongs to reticulated red clay developed in a hot-wet environment of the last interglacial period(132―73 ka BP),similar to the monsoon environment in the northern margin of modern tropical zone,while the overlying brown-yellow silt layer mainly accumulated in a monsoon environment of warm temperate zone in the last glacial period(73―11 ka BP),with the aeolian sand LJ3 representing an extreme period of worsening climate.Such a hypothesis corresponds well with predecessors' research on the paleoenvironment indicated by abundant fossils in both south and east to the Nanling Mountains.Hence,it follows that the bioclimatic zone did experience a large and rapid vicissitude in northeastern part of China's Guangdong Province,and even in the full extent of the region south to the Nanling Mountains from the last interglacial period to the last glacial period,with the red earth being replaced by the brown-yellow silty sediment,and even maybe with the Ailuropoda-Stegodon Fauna being replaced by the Penghu Fauna.This study may provide an important geological demonstration for the environmental response to global change in China's low latitudes on a 10 ka scale.
