Spatial distribution patterns of element concentrations can reflect the information of the mineralization processes. Both the Hurst exponent calculated by R/S analysis and the generalized fractal dimension calculated ...Spatial distribution patterns of element concentrations can reflect the information of the mineralization processes. Both the Hurst exponent calculated by R/S analysis and the generalized fractal dimension calculated by using the multifractal model are important parameters for describing the spatial distribution of elements. Five long drill holes, named as M1, S1, S2, S3, and S4, have been selected in the Shizishan （狮子山） skarn orefield in Tongling （铜陵）, Anhui （安徽） Province, China. Marbles are well developed around M1 and skarn rocks are largely distributed along S1, S2, S3, and S4 drill holes. The drill holes were sampled evenly with an interval of 10 m and 16 trace elements have been measured. The mean of the △D（q） （the height of the generalized dimension spectrum） in the M1 drill hole is the lowest. In addition, the mean of the Hurst exponents of the 16 elements in the M1 drill hole is also much smaller than that of S1, S2, S3, S4 drill holes, which is in accordance with the analysis of the generalized dimension. It is indicated by the generalized dimension and Hurst exponent that the distribution of trace elements in the marbles is more random than that in the skarn. The result suggests that the mineralization process can change the randomness and persistence features of the element distribution.展开更多
REE geochemical characteristics of the magmatic rocks and gold deposits in Shizishan ore-field of Tongling were studied. Three types of the magmatic rocks have almost the same chondrite-normalized REE patterns, Eu and...REE geochemical characteristics of the magmatic rocks and gold deposits in Shizishan ore-field of Tongling were studied. Three types of the magmatic rocks have almost the same chondrite-normalized REE patterns, Eu and Ce anomalous values, and ∑REE, ∑LREE/∑HREE regular changes, which indicates that their magmas come from the same source and their digenetic mechanism is fractional crystallization. In three gold deposits, the mineral ores and related altered rocks have similar chondrite-normalized REE patterns and sharp Eu positive anomalous values. The REE contents reduced from the magmatic rocks to skamization or alteration magmatic rocks, skam type ores, sulphide type ores, wall-rocks limestone or marble. The REE geochemical characteristics of the ores and related rocks show that primary fluids originated from magmatic differentiation in lower pressure of shallow crust, ore-forming hydrothermal solutions gained REE and mineralization elements further from leaching the magmatic rocks, then superimposed and reformed the limestones or marbles and deposited ore-forming material.展开更多
Mining activities have created great wealth, but they have also discharged large quantities of tailings. As an important source of heavy metal contamination, sulfide tailings are usually disposed of in open-air impoun...Mining activities have created great wealth, but they have also discharged large quantities of tailings. As an important source of heavy metal contamination, sulfide tailings are usually disposed of in open-air impoundments and thus are exposed to microbial oxidation. Microbial activities greatly enhance sulfide oxidation and result in the release of heavy metals and the precipitation of iron (oxy) hydroxides and sulfates. These secondary minerals in turn influence the mobility of dissolved metals and play important roles in the natural attenuation of heavy metals. Elucidating the microbe–mineral interactions in tailings will improve our understanding of the environmental consequence of mining activities.展开更多
Objective The Shizishan Pb-Zn deposit is located in the southeastern margin of the Yangtze Block,and its Pb-Zn orebodies are mainly hosted in the Lower Cambrian Qingxudong Formation limestone.Previous researches have ...Objective The Shizishan Pb-Zn deposit is located in the southeastern margin of the Yangtze Block,and its Pb-Zn orebodies are mainly hosted in the Lower Cambrian Qingxudong Formation limestone.Previous researches have investigated the geological characteristics,geochemistry and fluid inclusions of this deposit.展开更多
Shizishan ore-field is a nonferrous and noble metal ore-field which is most rich in copper and gold.There are many types of fluid inclusions in minerals of the deposits.The homogeneous temperatures and the salinities ...Shizishan ore-field is a nonferrous and noble metal ore-field which is most rich in copper and gold.There are many types of fluid inclusions in minerals of the deposits.The homogeneous temperatures and the salinities of the fluid inclusions in main mineralization stages have wide ranges,while the different types of the fluid inclusions existed together and their homogeneous temperatures are almost identical in the same mineralization stage,which indicates that the ore-forming process has great relation with the fluid boiling.The gas and liquid chemical compositions and the carbon,hydrogen and oxygen isotopic compositions of the fluid inclusions show that the ore-forming fluids of copper-gold deposits have the same characteristics and evolution tendency,which reflects that the ore-forming material mainly came from the magmatism.The stratigraphic component and the meteoric water may mix in ore- forming fluids in the later mineralization stages.Furthermore,with the fall of the ore-forming temperature the ratios of water and rock decreased.The characteristics of chemical composition and carbon isotopic composition of fluid inclusions indicate that CH4 may play an important role for separating copper and gold in the ore-forming process.展开更多
LA-ICPMS zircon U-Pb dating of intrusive rocks from the Shizishan ore field,Tongling,Anhui Province shows that the crystallization ages of Baimangshan pyroxene diorite,Shizishan and Dongguashan quartz diorite are 139&...LA-ICPMS zircon U-Pb dating of intrusive rocks from the Shizishan ore field,Tongling,Anhui Province shows that the crystallization ages of Baimangshan pyroxene diorite,Shizishan and Dongguashan quartz diorite are 139±1.9,138.0±1.7,and 138.4±1.7 Ma,respectively.These three intrusions are high-potassium,alkali-rich,meta-aluminous,and are characterized by enrichment of light rare earth elements and large-ion lithophile elements,depletion of heavy rare-earth elements(HREE) and high field strength elements,and slightly negative Eu anomalies.In-situ Hf analysis of zircon for these three intrusions shows large ranges of Hf isotope compositions:the ε Hf(t) values are ε Hf(t)= 3.3 to 14.4 for Baimangshan,14.1 to 23.9 Dongguashan,and 14.7 to 26.9 for Shizishan.The ε Hf(t) values of both the Dongguashan and Shizishan quartz diorites are significantly lower than those of Baimangshan pyroxene diorite.Elemental geochemistry and in-situ zircon Hf isotope analyses indicate that the three intrusions were formed through mixing of granitic magma formed by partial melting of the lower crust and water-rich basic magma derived from the enriched lithospheric mantle.The Dongguashan and Shizishan quartz diorites involved greater crustal components than Baimangshan pyroxene diorite.The Dongguashan and Shizishan quartz diorites have geochemical features similar to the adakite,such as high Sr,low Y,and high Sr/Y ratios.Such geochemical features can be attributed to some fractional crystallization of apatite and sphene,and insignificant plagioclase fractional crystallization after magma mixing.These three intrusions are the products of complex crust-mantle interaction during the regional tectonic regime transition from compression to extension.展开更多
基金supported by the Special Plans of Science and Technology of the Ministry of Land and Resources (No. 20010103)Trans-century Training Program Foundation by the Ministry of Education, 111 Project (No. B07011)+1 种基金Program for Changjiang Scholars and Innovative Research Team in University (PCSIRT)State Key Laboratory of Geological Processes and Mineral Resources (No. GPMR200640)
文摘Spatial distribution patterns of element concentrations can reflect the information of the mineralization processes. Both the Hurst exponent calculated by R/S analysis and the generalized fractal dimension calculated by using the multifractal model are important parameters for describing the spatial distribution of elements. Five long drill holes, named as M1, S1, S2, S3, and S4, have been selected in the Shizishan （狮子山） skarn orefield in Tongling （铜陵）, Anhui （安徽） Province, China. Marbles are well developed around M1 and skarn rocks are largely distributed along S1, S2, S3, and S4 drill holes. The drill holes were sampled evenly with an interval of 10 m and 16 trace elements have been measured. The mean of the △D（q） （the height of the generalized dimension spectrum） in the M1 drill hole is the lowest. In addition, the mean of the Hurst exponents of the 16 elements in the M1 drill hole is also much smaller than that of S1, S2, S3, S4 drill holes, which is in accordance with the analysis of the generalized dimension. It is indicated by the generalized dimension and Hurst exponent that the distribution of trace elements in the marbles is more random than that in the skarn. The result suggests that the mineralization process can change the randomness and persistence features of the element distribution.
基金Project supported bythe National Natural Science Foundation of China (40472052)
文摘REE geochemical characteristics of the magmatic rocks and gold deposits in Shizishan ore-field of Tongling were studied. Three types of the magmatic rocks have almost the same chondrite-normalized REE patterns, Eu and Ce anomalous values, and ∑REE, ∑LREE/∑HREE regular changes, which indicates that their magmas come from the same source and their digenetic mechanism is fractional crystallization. In three gold deposits, the mineral ores and related altered rocks have similar chondrite-normalized REE patterns and sharp Eu positive anomalous values. The REE contents reduced from the magmatic rocks to skamization or alteration magmatic rocks, skam type ores, sulphide type ores, wall-rocks limestone or marble. The REE geochemical characteristics of the ores and related rocks show that primary fluids originated from magmatic differentiation in lower pressure of shallow crust, ore-forming hydrothermal solutions gained REE and mineralization elements further from leaching the magmatic rocks, then superimposed and reformed the limestones or marbles and deposited ore-forming material.
文摘Mining activities have created great wealth, but they have also discharged large quantities of tailings. As an important source of heavy metal contamination, sulfide tailings are usually disposed of in open-air impoundments and thus are exposed to microbial oxidation. Microbial activities greatly enhance sulfide oxidation and result in the release of heavy metals and the precipitation of iron (oxy) hydroxides and sulfates. These secondary minerals in turn influence the mobility of dissolved metals and play important roles in the natural attenuation of heavy metals. Elucidating the microbe–mineral interactions in tailings will improve our understanding of the environmental consequence of mining activities.
基金financially supported by the National Natural Science Foundation of China(grant No.41303026)
文摘Objective The Shizishan Pb-Zn deposit is located in the southeastern margin of the Yangtze Block,and its Pb-Zn orebodies are mainly hosted in the Lower Cambrian Qingxudong Formation limestone.Previous researches have investigated the geological characteristics,geochemistry and fluid inclusions of this deposit.
基金the National Natural Science Foundation of China （ No. 40472052） is sincerely acknowledged.
文摘Shizishan ore-field is a nonferrous and noble metal ore-field which is most rich in copper and gold.There are many types of fluid inclusions in minerals of the deposits.The homogeneous temperatures and the salinities of the fluid inclusions in main mineralization stages have wide ranges,while the different types of the fluid inclusions existed together and their homogeneous temperatures are almost identical in the same mineralization stage,which indicates that the ore-forming process has great relation with the fluid boiling.The gas and liquid chemical compositions and the carbon,hydrogen and oxygen isotopic compositions of the fluid inclusions show that the ore-forming fluids of copper-gold deposits have the same characteristics and evolution tendency,which reflects that the ore-forming material mainly came from the magmatism.The stratigraphic component and the meteoric water may mix in ore- forming fluids in the later mineralization stages.Furthermore,with the fall of the ore-forming temperature the ratios of water and rock decreased.The characteristics of chemical composition and carbon isotopic composition of fluid inclusions indicate that CH4 may play an important role for separating copper and gold in the ore-forming process.
基金supported by National Basic Research Program of China (GrantNo. 2012CB416702)National Natural Science Foundation of China(Grant No. 40930742)+1 种基金Key Project of Natural Science Foundation of Jiangsu Province (Grant No. BK2008026)National Key Technology R&D Program (Grant No. 2009BAB43B03)
文摘LA-ICPMS zircon U-Pb dating of intrusive rocks from the Shizishan ore field,Tongling,Anhui Province shows that the crystallization ages of Baimangshan pyroxene diorite,Shizishan and Dongguashan quartz diorite are 139±1.9,138.0±1.7,and 138.4±1.7 Ma,respectively.These three intrusions are high-potassium,alkali-rich,meta-aluminous,and are characterized by enrichment of light rare earth elements and large-ion lithophile elements,depletion of heavy rare-earth elements(HREE) and high field strength elements,and slightly negative Eu anomalies.In-situ Hf analysis of zircon for these three intrusions shows large ranges of Hf isotope compositions:the ε Hf(t) values are ε Hf(t)= 3.3 to 14.4 for Baimangshan,14.1 to 23.9 Dongguashan,and 14.7 to 26.9 for Shizishan.The ε Hf(t) values of both the Dongguashan and Shizishan quartz diorites are significantly lower than those of Baimangshan pyroxene diorite.Elemental geochemistry and in-situ zircon Hf isotope analyses indicate that the three intrusions were formed through mixing of granitic magma formed by partial melting of the lower crust and water-rich basic magma derived from the enriched lithospheric mantle.The Dongguashan and Shizishan quartz diorites involved greater crustal components than Baimangshan pyroxene diorite.The Dongguashan and Shizishan quartz diorites have geochemical features similar to the adakite,such as high Sr,low Y,and high Sr/Y ratios.Such geochemical features can be attributed to some fractional crystallization of apatite and sphene,and insignificant plagioclase fractional crystallization after magma mixing.These three intrusions are the products of complex crust-mantle interaction during the regional tectonic regime transition from compression to extension.
