For revealing the ore sources of the Dachang tin?polymetallic ore deposit, the lead isotopes were analyzed systematically by using the single minerals of sulphides, including pyrite, pyrrhotite, sphalerite, and galena...For revealing the ore sources of the Dachang tin?polymetallic ore deposit, the lead isotopes were analyzed systematically by using the single minerals of sulphides, including pyrite, pyrrhotite, sphalerite, and galena. Then, the mineral sources and their characteristics were discussed based on the classical lead isotope discriminating model. The results show that the lead isotope ratios of206Pb/204Pb,207Pb/204Pb, and208Pb/204Pb range from 17.478 to 18.638, 15.440 to 15.858, and 37.556 to 39.501, respectively. According to Zartman lead model, the ore lead contains the upper crust composition; however, the granite does not provide all ore leads, and other material sources exist. Obviously, the ore deposit belongs to the result of the combined effect of crust?mantle. The source rocks are characterized by a certain degree of similarity with the island arc material. Moreover, its distant origin in the upper and lower crusts may be related to the subduction island arc material or oceanic crust. The mantle-derived material may have a certain status in the source region. Meanwhile, based on the lead isotope three-dimensional topology projection vectors, the ore leads are concentrated in zoneA, which indicates the characteristics of Yangtze lead isotope province and a possible genetic relationship with Yangtze block.展开更多
This paper reports the variation rules for the typomorphic parameters of the pyrite and the gold enrichment rules of the Denggezhuang quartz vein gold deposit at a large-depth scale, providing the mineral signs for de...This paper reports the variation rules for the typomorphic parameters of the pyrite and the gold enrichment rules of the Denggezhuang quartz vein gold deposit at a large-depth scale, providing the mineral signs for deep prospecting prediction through detailed study of the characteristics of crystal＇ habits, chemical composition, the thermoelectricity of pyrites, and min- eralogical mapping. This paper primarily discusses the correlation between the mineralization intensity and the space-time evolution of the mineralogical parameters, clarifies the physicochemical conditions during gold mineralization, and provides information useful for deep mineralization prediction. We demonstrate that the crystal habits of the pyrites are very complex, primarily occurring as （ 100）, （210）, and their combinate form. （210） and （ 100）＋（210） have positive correlations with gold mineralization, and （ 100）＋（210） therefore can be useful for locating rich ore segments. The composition of pyrites is charac- teristically poor in S and rich in As. Their typical trace elements are composed of Mo, As, Pb, Cu, Bi, Zn, Au, Co, Se, Sb, Ag, Ni, Cr, and Te. The average contents of trace elements in pyrites from various stages show that the crystallizing temperature gradually decreased from an early stage to the metallogenic episodes. The precipitation and accumulation of Au and Ag occur primarily in the quartz-pyrite stage （III） and the polymetal minerals stage （IV）. The occurrence rate of P-type pyrites （P（%）） is 83.52%. There is a larger dispersion of the thermoelectrical coefficient of pyrite （a） in the Denggezhuang gold deposit than in other deposits in the Jiaodong Peninsula. The electrical conductivity assemblage of pyrites from I to V is characterized by P〉N〉P〉N〉P〉〉N〉P〉〉N〉P〉N, which is usually considered beneficial for mineralization. The relative contents of As＋Sb＋Se＋Te and Co＋Ni are closely correlated to P-type and N-type average values and their occurrence rates. According to the crystallizing temperature of pyrite, the mineralization intensity, and the denudation degree, the mineralization temperature of the Denggezhuang gold deposit is in the range of 150-322~C and is of a medium-low temperature. The orebody has already become denuded to the top-middle of the orebody, and the size of the orebody is larger than 900 m. Based on the vertical zon- ing of the thermoelectrical coefficients of pyrites and P-type pyrite mapping, it is suggested that the segment between -425 and -800 m may have exploration potential to the northeast of line 94 of the No. I2.2 orebody.展开更多
基金Project(41202051)supported by the National Natural Science Foundation of ChinaProject(S2014GK3005)supported by Hunan Industrial Science and Technology Support Program+1 种基金Project(2012M521721)supported by China Postdoctoral Science FoundationProject(CSUZC2013021)supported by the Open-end Fund for the Valuable and Precision Instruments of Central South University,China
文摘For revealing the ore sources of the Dachang tin?polymetallic ore deposit, the lead isotopes were analyzed systematically by using the single minerals of sulphides, including pyrite, pyrrhotite, sphalerite, and galena. Then, the mineral sources and their characteristics were discussed based on the classical lead isotope discriminating model. The results show that the lead isotope ratios of206Pb/204Pb,207Pb/204Pb, and208Pb/204Pb range from 17.478 to 18.638, 15.440 to 15.858, and 37.556 to 39.501, respectively. According to Zartman lead model, the ore lead contains the upper crust composition; however, the granite does not provide all ore leads, and other material sources exist. Obviously, the ore deposit belongs to the result of the combined effect of crust?mantle. The source rocks are characterized by a certain degree of similarity with the island arc material. Moreover, its distant origin in the upper and lower crusts may be related to the subduction island arc material or oceanic crust. The mantle-derived material may have a certain status in the source region. Meanwhile, based on the lead isotope three-dimensional topology projection vectors, the ore leads are concentrated in zoneA, which indicates the characteristics of Yangtze lead isotope province and a possible genetic relationship with Yangtze block.
基金financially supported by the Key Program of National Natural Science Foundation of China(Grant No.90914002)the Ore-Prospecting Project for Critical Mines(Grant No.20089937)+1 种基金Scheduled Program of China Geological Survey(Grant No.1212011220926)the Institution of Higher Education Innovation and Intelligence Attraction Program(Grant No.B07011)
文摘This paper reports the variation rules for the typomorphic parameters of the pyrite and the gold enrichment rules of the Denggezhuang quartz vein gold deposit at a large-depth scale, providing the mineral signs for deep prospecting prediction through detailed study of the characteristics of crystal＇ habits, chemical composition, the thermoelectricity of pyrites, and min- eralogical mapping. This paper primarily discusses the correlation between the mineralization intensity and the space-time evolution of the mineralogical parameters, clarifies the physicochemical conditions during gold mineralization, and provides information useful for deep mineralization prediction. We demonstrate that the crystal habits of the pyrites are very complex, primarily occurring as （ 100）, （210）, and their combinate form. （210） and （ 100）＋（210） have positive correlations with gold mineralization, and （ 100）＋（210） therefore can be useful for locating rich ore segments. The composition of pyrites is charac- teristically poor in S and rich in As. Their typical trace elements are composed of Mo, As, Pb, Cu, Bi, Zn, Au, Co, Se, Sb, Ag, Ni, Cr, and Te. The average contents of trace elements in pyrites from various stages show that the crystallizing temperature gradually decreased from an early stage to the metallogenic episodes. The precipitation and accumulation of Au and Ag occur primarily in the quartz-pyrite stage （III） and the polymetal minerals stage （IV）. The occurrence rate of P-type pyrites （P（%）） is 83.52%. There is a larger dispersion of the thermoelectrical coefficient of pyrite （a） in the Denggezhuang gold deposit than in other deposits in the Jiaodong Peninsula. The electrical conductivity assemblage of pyrites from I to V is characterized by P〉N〉P〉N〉P〉〉N〉P〉〉N〉P〉N, which is usually considered beneficial for mineralization. The relative contents of As＋Sb＋Se＋Te and Co＋Ni are closely correlated to P-type and N-type average values and their occurrence rates. According to the crystallizing temperature of pyrite, the mineralization intensity, and the denudation degree, the mineralization temperature of the Denggezhuang gold deposit is in the range of 150-322~C and is of a medium-low temperature. The orebody has already become denuded to the top-middle of the orebody, and the size of the orebody is larger than 900 m. Based on the vertical zon- ing of the thermoelectrical coefficients of pyrites and P-type pyrite mapping, it is suggested that the segment between -425 and -800 m may have exploration potential to the northeast of line 94 of the No. I2.2 orebody.
