Since 2011,certain advances have been made through the resource investigation,metallogenesis research,mining supervision and environmental protection of ion-adsorption type rare earth element (REE) deposit in South Ch...Since 2011,certain advances have been made through the resource investigation,metallogenesis research,mining supervision and environmental protection of ion-adsorption type rare earth element (REE) deposit in South China.Firstly,some progress has been made in REE prospecting in Jiangxi,Guangdong,Guangxi and Yunnan.REE deposits are not only found within the weathering crusts of granites and felsic volcanic rocks,but also within the weathering crusts of epimetamorphic rocks and basic magmatic rocks.Secondly,the methods of exploration,delineating ore bodies and calculation of reserves have been improved,which intuitively reflect the thickness,REE composition and value of weathering crust.Thirdly,the relationship between REEs and weathering degree and the rule of distribution,migration and enrichment of REEs in the weathering profile was summarized through the analysis of big data,which can predict the metallogenetic horizon of REEs.Fourthly,a method for quick,accurate and dynamic investigation of the REE deposit has been established by using high resolution remote sensing technology.Finally,the relation between the production status of REE mines and water pollution has been revealed based on long-term hydrochemical monitoring data of rivers and wells in mines and surrounding areas.展开更多
Based on characteristics of unaltered rocks and REE patterns, ion-adsorpted RE deposits can be devided into four types including Y-rich and Eu-poor granites, Y-mid and and Eu low granites, Eu-rich granites, Eu-mid vol...Based on characteristics of unaltered rocks and REE patterns, ion-adsorpted RE deposits can be devided into four types including Y-rich and Eu-poor granites, Y-mid and and Eu low granites, Eu-rich granites, Eu-mid volcanic and subvolcanic rocks. The distribution of REE contents in weathered profiles shows an are-shaped pattern. It indicates that the REE contents are enriched in full weathered and upper parts of sub-weathered zones. The REE patterns-in weathered crusts also demonstrate characteristics essentially inherited from those in unaltered rocks; On the other hand, cerium; has a positive anomaly in soil zone and negative anomalies in full weathered and sub-weathered zones. Gradual decrease in the slopes of the REE pattern curves indicates that HREE contents are more enriched than LREE in lower portion of the pro files. REE abundance in unaltered rocks and appropriate climate are essential conditions for ion adsorpted deposits. According to experiments of the REE adsorption on clay minerals, REE concentrations, pH values and ion strength in solutions significantly affect adsorption contents and partition coefficients. The distribution of the REE in weathered profiles are controlled by percolation and adsorption coupling in groundwater-rock interaction systems.展开更多
In this paper the geochemical characteristics of rare earth elements in Guposhan granite complex in Nanling Area,South China,is systematically studied,and the balance of REE distribution in rock-forming minerals, whic...In this paper the geochemical characteristics of rare earth elements in Guposhan granite complex in Nanling Area,South China,is systematically studied,and the balance of REE distribution in rock-forming minerals, which contain only 21.47～29.71 wt% of total REE in granites,is calculated.The petrogenetic relationship be- tween three different stages of the granites in the complex is discussed,and a geochemical model is suggested for the formation of granitic magma in early stage by partial melting of the crustal basement rocks containing more REE than that in the late stage.It shows that a ion-adsorption type of REE deposit could ocuur in the weath- ering crust on the early stage granite.Rb-Sr isotope isochron dating of the first stage medium-coarse-grained K-feldspar granite shows that its age is 146.5 Ma and initial ^(87)Sr/^(86)Sr ratio is 0.71198.展开更多
文摘Since 2011,certain advances have been made through the resource investigation,metallogenesis research,mining supervision and environmental protection of ion-adsorption type rare earth element (REE) deposit in South China.Firstly,some progress has been made in REE prospecting in Jiangxi,Guangdong,Guangxi and Yunnan.REE deposits are not only found within the weathering crusts of granites and felsic volcanic rocks,but also within the weathering crusts of epimetamorphic rocks and basic magmatic rocks.Secondly,the methods of exploration,delineating ore bodies and calculation of reserves have been improved,which intuitively reflect the thickness,REE composition and value of weathering crust.Thirdly,the relationship between REEs and weathering degree and the rule of distribution,migration and enrichment of REEs in the weathering profile was summarized through the analysis of big data,which can predict the metallogenetic horizon of REEs.Fourthly,a method for quick,accurate and dynamic investigation of the REE deposit has been established by using high resolution remote sensing technology.Finally,the relation between the production status of REE mines and water pollution has been revealed based on long-term hydrochemical monitoring data of rivers and wells in mines and surrounding areas.
文摘Based on characteristics of unaltered rocks and REE patterns, ion-adsorpted RE deposits can be devided into four types including Y-rich and Eu-poor granites, Y-mid and and Eu low granites, Eu-rich granites, Eu-mid volcanic and subvolcanic rocks. The distribution of REE contents in weathered profiles shows an are-shaped pattern. It indicates that the REE contents are enriched in full weathered and upper parts of sub-weathered zones. The REE patterns-in weathered crusts also demonstrate characteristics essentially inherited from those in unaltered rocks; On the other hand, cerium; has a positive anomaly in soil zone and negative anomalies in full weathered and sub-weathered zones. Gradual decrease in the slopes of the REE pattern curves indicates that HREE contents are more enriched than LREE in lower portion of the pro files. REE abundance in unaltered rocks and appropriate climate are essential conditions for ion adsorpted deposits. According to experiments of the REE adsorption on clay minerals, REE concentrations, pH values and ion strength in solutions significantly affect adsorption contents and partition coefficients. The distribution of the REE in weathered profiles are controlled by percolation and adsorption coupling in groundwater-rock interaction systems.
基金The research is supported by the National Natural Science Foundation of China
文摘In this paper the geochemical characteristics of rare earth elements in Guposhan granite complex in Nanling Area,South China,is systematically studied,and the balance of REE distribution in rock-forming minerals, which contain only 21.47～29.71 wt% of total REE in granites,is calculated.The petrogenetic relationship be- tween three different stages of the granites in the complex is discussed,and a geochemical model is suggested for the formation of granitic magma in early stage by partial melting of the crustal basement rocks containing more REE than that in the late stage.It shows that a ion-adsorption type of REE deposit could ocuur in the weath- ering crust on the early stage granite.Rb-Sr isotope isochron dating of the first stage medium-coarse-grained K-feldspar granite shows that its age is 146.5 Ma and initial ^(87)Sr/^(86)Sr ratio is 0.71198.
