The Muli antimony deposit is located in the Au-Sb polymetallic metallogenic belt in south-eastern Yunnan,China.In this paper,we investigated the concentrations of trace elements in gangue minerals,mainly calcite,quart...The Muli antimony deposit is located in the Au-Sb polymetallic metallogenic belt in south-eastern Yunnan,China.In this paper,we investigated the concentrations of trace elements in gangue minerals,mainly calcite,quartz,and pyrite,which were formed at different metallogenic stages.Meanwhile,the host rocks,predominantly composed of limestone,are also analysed for comparison.The calcite from the Nadan ore section is enriched with medium-heavy rare earth elements(M-HREEs),likely due to the presence of a high concentration of Fe and Mn impurities,which results in the preferential enrichment of M-HREEs in the calcite.Alternatively,the calcite may be precipitated from the M-HREE・rich granitic leaching fluid.In the Muli ore section,both quartz and pyrite in the metallogenic period show enrichment with light rare earth elements(LREEs),and the wall rock is also enriched with LREEs,which indicates that the wall rock material was involved in the metallogenic process.The W-shaped tetrad effect of quartz in the late metallogenic stage was interpreted to determine extensive flu id-rock interactions in highly fractionated Si-rich systems.Fe and Mn impurities cause M-HREE to be preferentially enriched with calcite to some extent.Whether mineralization is related to granite deserves further study.Eu and Ce anomalies of different types of gangue minerals indicate that the temperature and the fO2 were constantly changing during mineralization,and the temperature of the main ore-stage was higher than 200°C in an oxidized state.The various REE patterns,LREE/HREE and(La/Yb)N values,reveal that there may be multi-sources and multi-stage hydrothermal activities in the Muli antimony deposit.The REE distribution patterns of minerals are likely interfered with by many internal and external factors.Studies on REE characteristics of calcite,quartz,pyrite and limestone in the Muli antimony deposit have greatly improved the understanding of ore-forming fluids.When we traced the origin and evolution of ore・forming fluids by means of mineral REE distribution patterns,in addition to the determination of inclusions of ore minerals related to mineralization and the in situ analysis methods performed by LA-ICP-MS,we should also com・bine the REE characteristics of various minerals or trace the ore-forming fluids with multiple methods.展开更多
The Yao'an Pb–Ag deposit, located in the Chuxiong Basin, western Yangtze Block, is an important component of the Jinshajiang–Ailaoshan alkaline porphyry–related polymetallic intrusive belt. This complex suite o...The Yao'an Pb–Ag deposit, located in the Chuxiong Basin, western Yangtze Block, is an important component of the Jinshajiang–Ailaoshan alkaline porphyry–related polymetallic intrusive belt. This complex suite of rock bodies includes a vein of pseudoleucite porphyry within deposits of syenite porphyry and trachyte.The pseudoleucite is characterized by a variable greyish,greyish-white, and greyish-green porphyritic texture. Phenocrysts are mainly pseudoleucite with small amounts of alkali feldspar and biotite. In an intense event, leucite phenocrysts altered to orthoclase, kaolinite, and quartz.Both the pseudoleucite porphyry and the syenite porphyry samples were typical alkali-rich, K-rich, al-rich rocks with high LaN/YbNratios; enriched in light rare earth elements and large-ion lithophile elements, and depleted in high field strength elements; and with strongly negative Ta, Nb, and Ti(TNT) anomalies and slightly negative Eu anomalies—all characteristics of subduction-zone mantle-derived rock.We obtained a LA-ICP-MS zircon U–Pb age of 34.1 ± 0.3 Ma(MSWD = 2.4), which is younger than the established age of the Indian and Eurasian Plate collision.The magma derived from a Type-II enriched mantle formed in a post-collisional plate tectonic setting. The geochemical characteristics of the Yao'an pseudoleucite porphyry are powerful evidence that the porphyry'sdevelopment was closely linked to the Jinshajiang–Ailaoshan fault and to the Indian-Eurasian collision.展开更多
Based on the research content and conception of dynamics of tectonic ore-forming processes, with the focus on the dynamics and processes of mineral source, ore formation, transport, accumulation, dissipation and miner...Based on the research content and conception of dynamics of tectonic ore-forming processes, with the focus on the dynamics and processes of mineral source, ore formation, transport, accumulation, dissipation and mineralization in response to magmatic invasion and metallogenic fluid under tectonic stress, this paper deals with the ore-finding method of fault tectono-geochemistry and its application on the basis of ore deposit genesis, "giant pressure shadow" structure and ore-finding method of tectonic stress field in the Tongchang orefield, expounds the rules of magmatic emplacement and ore fluid migration and concentration under the control of the structural stress field, hence providing the theoretical basis for the localization and prognosis of concealed ores. The fault tectono-geochemical features show that the Cu-Au polymetallic ore deposits (mineralization) in the orefield are closely related with volcano-(exhalation) sedimentation, magmatism and tectono-reworking. Fault tectono-geochemical anomalies can be applied to prognosis of metallogenetic target areas for ore exploration and can provide strong evidence of "giant pressure shadow" structure. In addition, quite a number of important target areas have been defined in combination with the characteristics of the tectonic stress field, and part of the target areas have been proved by practical activities.展开更多
The Tongchang orefield is located in the central part of the Mianxian-Lueyang-Yangpingguan area that is celebrated as a 'gold triangle' area,at the juncture of the latitudinal tectonic zone of South Qinling,th...The Tongchang orefield is located in the central part of the Mianxian-Lueyang-Yangpingguan area that is celebrated as a 'gold triangle' area,at the juncture of the latitudinal tectonic zone of South Qinling,the Longmenshan Cathysian tectonic zone and the Sichuan-Yunnan longitudinal tectonic zone,where there are distributed Cu-Au polymetallic ore deposits(occurrences) including the Tongchang,Chenjiaba,Qinjiabian,Hongtushi,Yinshangou and Xiakouyi ore deposits(mineralization).Based on the "giant pressure shadow" structure put forward and demonstrated by numerical modeling of the tectonic stress field and the static photoelasticity experiments on the basis of tectonic ore-controlling laws in the orefield,tectonic metallogenesis driven by orefield tectonic stress has been discussed in terms of its geological setting,orefield geomechanics,and tectonic stress field.It is thought that the dynamic evolution model of the tectonic stress field controls the whole process of formation of the polymetallic ore deposits(mineralization) in the orefield,as well as the deformation field.As a result,it controls the emplacement of rockbodies and the transformation of ore-source bodies,and provides both the channel-ways for ore-forming fluids and ore-hosting space.Furthermore,it controls the migration potential field of fluids and,thereafter,its flow direction,rate and volume;the tectonic stress field also controls the energy field and hence controls the position of occurrence of ore deposits and their scale.The method of tectonic stress field has been applied to ore prognosis in the orefield.The rules of magmatic emplacement and metallogenic fluid migrating and concentrating under the control of the structural stress field were expounded,hence providing the theoretical basis for the prognosis of concealed ores.In addition,a number of important target areas have been defined.展开更多
The orogenic gold deposits in Southeast Guizhou are an important component of the Xuefeng polymetallic ore belt and have significant exploration potential, but geochronology research on these gold deposits is scarce. ...The orogenic gold deposits in Southeast Guizhou are an important component of the Xuefeng polymetallic ore belt and have significant exploration potential, but geochronology research on these gold deposits is scarce. Therefore, the ore genetic models are poorly constrained and remain unclear. In the present study, two important deposits(Pingqiu and Jinjing) are investigated, including combined Re-Os dating and the He-Ar isotope study of auriferous arsenopyrites. It is found that the arsenopyrites from the Pingqiu gold deposit yielded an isochron age of 400 ± 24 Ma,with an initial ^(187)Os/^(188)Os ratio of 1.24 ± 0.57(MSWD = 0.96). An identical isochron age of 400 ± 11 Ma with an initial ^(187)Os/^(188)Os ratio of 1.55 ± 0.14(MSWD = 0.34) was obtained from the Jinjing deposit. These ages correspond to the regional Caledonian orogeny and are interpreted to represent the age of the main stage ore. Both initial ^(187)Os ratios suggest that the Os was derived from crustal rocks. Combined with previous rare earth element(REE), trace elements, Nd-Sr-S-Pb isotope studies on scheelite, inclusion fluids with other residues of gangue quartz, and sulfides from other gold deposits in the region, it is suggested that the ore metals from Pingqiu and Jinjing were sourced from the Xiajiang Group. The He and Ar isotopes of arsenopyrites are characterized by ~3 He/~4 He ratios ranging from 5.3 × 10^(-4) Ra to 2.5 × 10^(-2) Ra(Ra = 1.4 × 10^(-6), the ~3 He/~4 He ratio of air), 40 Ar=/~4 He ratios from 0.64 × 10^(-2) to 15.39×10^(-2), and ^(40)Ar/^(36)Ar ratios from 633.2 to 6582.0. Those noble gas isotopic compositions of fluid inclusions also support a crustal source origin,evidenced by the Os isotope. Meanwhile, recent noble gas studies suggest that the amount of in situ radiogenic ~4 He generated should not be ignored, even when Th and U are present at levels of only a few ppm in host minerals.展开更多
1 Introduction The well-known1 Sichuan-Yunnan-Guizhou Triangle(SYGT)area of poly-metallic Zn-Pb deposits,southwest China is located at the south-western margin of the Yangtze Block in the transition area of the Tethys...1 Introduction The well-known1 Sichuan-Yunnan-Guizhou Triangle(SYGT)area of poly-metallic Zn-Pb deposits,southwest China is located at the south-western margin of the Yangtze Block in the transition area of the Tethys Belt and the Circum-Pacific Metallogenic Belt,and is composed of the Northeastern Yunnan,Northwestern展开更多
1 Introduction The Lehonglead-zincdeposit is a large-sized Pb-Zn depositnewly found in recent years in the Sichuan-Yunnan-Guizhou Lead-zinc Poly-metallic Mineralization Area,which occurrenceis strictly
The type, size, and compositions of fluid inclusions in a natural sphalerite were investigated and the total concentration of Zn released from the fluid inclusions was measured. To compare the total concentration of Z...The type, size, and compositions of fluid inclusions in a natural sphalerite were investigated and the total concentration of Zn released from the fluid inclusions was measured. To compare the total concentration of Zn released from the fluid inclusions with that dissolved from the sphalerite itself, dissolution experiments and theoretical calculations for the dissolution equilibrium of the sphalerite were also performed. The results indicate that large numbers of fluid inclusions with various sizes exist in the sphalerite, which can be divided into four types, i.e., pure gaseous inclusions, pure liquid inclusions, gas-liquid inclusions, and gas-liquid inclusions containing solid minerals. These inclusions were broken open during the grinding process, and their compositions were released to the solution. The total concentration of Zn released from these inclusions reaches 18.35×10^-6 mol/L, which is much higher than that of Zn dissolved from the sphalerite itself （1.93×10^-6 mol/L） and the theoretical calculation value （2.73×10^-8 mol/L）.展开更多
1 Introduction The Huize Zn-Pb district is located in the tectonic composite position,became one of the important production areas of zinc,lead and germanium in China.In the Huize lead-zinc deposit,the interlayer faul...1 Introduction The Huize Zn-Pb district is located in the tectonic composite position,became one of the important production areas of zinc,lead and germanium in China.In the Huize lead-zinc deposit,the interlayer faults are most展开更多
基金supported by the National Natural Science Foundation of China (Grant Nos. 41772070, 41303038)Open Fund of State Key Laboratory of Ore Deposit Geochemistry (201502)
文摘The Muli antimony deposit is located in the Au-Sb polymetallic metallogenic belt in south-eastern Yunnan,China.In this paper,we investigated the concentrations of trace elements in gangue minerals,mainly calcite,quartz,and pyrite,which were formed at different metallogenic stages.Meanwhile,the host rocks,predominantly composed of limestone,are also analysed for comparison.The calcite from the Nadan ore section is enriched with medium-heavy rare earth elements(M-HREEs),likely due to the presence of a high concentration of Fe and Mn impurities,which results in the preferential enrichment of M-HREEs in the calcite.Alternatively,the calcite may be precipitated from the M-HREE・rich granitic leaching fluid.In the Muli ore section,both quartz and pyrite in the metallogenic period show enrichment with light rare earth elements(LREEs),and the wall rock is also enriched with LREEs,which indicates that the wall rock material was involved in the metallogenic process.The W-shaped tetrad effect of quartz in the late metallogenic stage was interpreted to determine extensive flu id-rock interactions in highly fractionated Si-rich systems.Fe and Mn impurities cause M-HREE to be preferentially enriched with calcite to some extent.Whether mineralization is related to granite deserves further study.Eu and Ce anomalies of different types of gangue minerals indicate that the temperature and the fO2 were constantly changing during mineralization,and the temperature of the main ore-stage was higher than 200°C in an oxidized state.The various REE patterns,LREE/HREE and(La/Yb)N values,reveal that there may be multi-sources and multi-stage hydrothermal activities in the Muli antimony deposit.The REE distribution patterns of minerals are likely interfered with by many internal and external factors.Studies on REE characteristics of calcite,quartz,pyrite and limestone in the Muli antimony deposit have greatly improved the understanding of ore-forming fluids.When we traced the origin and evolution of ore・forming fluids by means of mineral REE distribution patterns,in addition to the determination of inclusions of ore minerals related to mineralization and the in situ analysis methods performed by LA-ICP-MS,we should also com・bine the REE characteristics of various minerals or trace the ore-forming fluids with multiple methods.
基金funded by National Natural Science Foundation of China (Grant Number:41102049)Mineral Resources Prediction and Evaluation Engineering Laboratory of Yunnan Provincethe Program of Provincial and University Innovation Team
文摘The Yao'an Pb–Ag deposit, located in the Chuxiong Basin, western Yangtze Block, is an important component of the Jinshajiang–Ailaoshan alkaline porphyry–related polymetallic intrusive belt. This complex suite of rock bodies includes a vein of pseudoleucite porphyry within deposits of syenite porphyry and trachyte.The pseudoleucite is characterized by a variable greyish,greyish-white, and greyish-green porphyritic texture. Phenocrysts are mainly pseudoleucite with small amounts of alkali feldspar and biotite. In an intense event, leucite phenocrysts altered to orthoclase, kaolinite, and quartz.Both the pseudoleucite porphyry and the syenite porphyry samples were typical alkali-rich, K-rich, al-rich rocks with high LaN/YbNratios; enriched in light rare earth elements and large-ion lithophile elements, and depleted in high field strength elements; and with strongly negative Ta, Nb, and Ti(TNT) anomalies and slightly negative Eu anomalies—all characteristics of subduction-zone mantle-derived rock.We obtained a LA-ICP-MS zircon U–Pb age of 34.1 ± 0.3 Ma(MSWD = 2.4), which is younger than the established age of the Indian and Eurasian Plate collision.The magma derived from a Type-II enriched mantle formed in a post-collisional plate tectonic setting. The geochemical characteristics of the Yao'an pseudoleucite porphyry are powerful evidence that the porphyry'sdevelopment was closely linked to the Jinshajiang–Ailaoshan fault and to the Indian-Eurasian collision.
基金This research project was granted jointly by the Funds for Program for NSF (40863002)NCET in University (NCET-04-917)the Project for the Distinguishing Discipline of KUST (2008)
文摘Based on the research content and conception of dynamics of tectonic ore-forming processes, with the focus on the dynamics and processes of mineral source, ore formation, transport, accumulation, dissipation and mineralization in response to magmatic invasion and metallogenic fluid under tectonic stress, this paper deals with the ore-finding method of fault tectono-geochemistry and its application on the basis of ore deposit genesis, "giant pressure shadow" structure and ore-finding method of tectonic stress field in the Tongchang orefield, expounds the rules of magmatic emplacement and ore fluid migration and concentration under the control of the structural stress field, hence providing the theoretical basis for the localization and prognosis of concealed ores. The fault tectono-geochemical features show that the Cu-Au polymetallic ore deposits (mineralization) in the orefield are closely related with volcano-(exhalation) sedimentation, magmatism and tectono-reworking. Fault tectono-geochemical anomalies can be applied to prognosis of metallogenetic target areas for ore exploration and can provide strong evidence of "giant pressure shadow" structure. In addition, quite a number of important target areas have been defined in combination with the characteristics of the tectonic stress field, and part of the target areas have been proved by practical activities.
基金Granted jointly by the Funds for Program for NCET in University (NCET-04-917)NSF (40863002)Project for the Distinguishing Discipline of KUST (2008)
文摘The Tongchang orefield is located in the central part of the Mianxian-Lueyang-Yangpingguan area that is celebrated as a 'gold triangle' area,at the juncture of the latitudinal tectonic zone of South Qinling,the Longmenshan Cathysian tectonic zone and the Sichuan-Yunnan longitudinal tectonic zone,where there are distributed Cu-Au polymetallic ore deposits(occurrences) including the Tongchang,Chenjiaba,Qinjiabian,Hongtushi,Yinshangou and Xiakouyi ore deposits(mineralization).Based on the "giant pressure shadow" structure put forward and demonstrated by numerical modeling of the tectonic stress field and the static photoelasticity experiments on the basis of tectonic ore-controlling laws in the orefield,tectonic metallogenesis driven by orefield tectonic stress has been discussed in terms of its geological setting,orefield geomechanics,and tectonic stress field.It is thought that the dynamic evolution model of the tectonic stress field controls the whole process of formation of the polymetallic ore deposits(mineralization) in the orefield,as well as the deformation field.As a result,it controls the emplacement of rockbodies and the transformation of ore-source bodies,and provides both the channel-ways for ore-forming fluids and ore-hosting space.Furthermore,it controls the migration potential field of fluids and,thereafter,its flow direction,rate and volume;the tectonic stress field also controls the energy field and hence controls the position of occurrence of ore deposits and their scale.The method of tectonic stress field has been applied to ore prognosis in the orefield.The rules of magmatic emplacement and metallogenic fluid migrating and concentrating under the control of the structural stress field were expounded,hence providing the theoretical basis for the prognosis of concealed ores.In addition,a number of important target areas have been defined.
基金jointly supported by the National Natural Science Foundation of China (Grant Nos. 41303038, 41772070)Open Fund of State Key Laboratory of Ore Deposit Geochemistry (201502)the National Basic Research Program of China (2014CB440904)
文摘The orogenic gold deposits in Southeast Guizhou are an important component of the Xuefeng polymetallic ore belt and have significant exploration potential, but geochronology research on these gold deposits is scarce. Therefore, the ore genetic models are poorly constrained and remain unclear. In the present study, two important deposits(Pingqiu and Jinjing) are investigated, including combined Re-Os dating and the He-Ar isotope study of auriferous arsenopyrites. It is found that the arsenopyrites from the Pingqiu gold deposit yielded an isochron age of 400 ± 24 Ma,with an initial ^(187)Os/^(188)Os ratio of 1.24 ± 0.57(MSWD = 0.96). An identical isochron age of 400 ± 11 Ma with an initial ^(187)Os/^(188)Os ratio of 1.55 ± 0.14(MSWD = 0.34) was obtained from the Jinjing deposit. These ages correspond to the regional Caledonian orogeny and are interpreted to represent the age of the main stage ore. Both initial ^(187)Os ratios suggest that the Os was derived from crustal rocks. Combined with previous rare earth element(REE), trace elements, Nd-Sr-S-Pb isotope studies on scheelite, inclusion fluids with other residues of gangue quartz, and sulfides from other gold deposits in the region, it is suggested that the ore metals from Pingqiu and Jinjing were sourced from the Xiajiang Group. The He and Ar isotopes of arsenopyrites are characterized by ~3 He/~4 He ratios ranging from 5.3 × 10^(-4) Ra to 2.5 × 10^(-2) Ra(Ra = 1.4 × 10^(-6), the ~3 He/~4 He ratio of air), 40 Ar=/~4 He ratios from 0.64 × 10^(-2) to 15.39×10^(-2), and ^(40)Ar/^(36)Ar ratios from 633.2 to 6582.0. Those noble gas isotopic compositions of fluid inclusions also support a crustal source origin,evidenced by the Os isotope. Meanwhile, recent noble gas studies suggest that the amount of in situ radiogenic ~4 He generated should not be ignored, even when Th and U are present at levels of only a few ppm in host minerals.
基金funded by the Funds for the program of the National Natural Science Foundation(Noes.41572060,U1133602)Projects of YM Lab(2011)Innovation Team of Yunnan province and KMUST(2008,2012)
文摘1 Introduction The well-known1 Sichuan-Yunnan-Guizhou Triangle(SYGT)area of poly-metallic Zn-Pb deposits,southwest China is located at the south-western margin of the Yangtze Block in the transition area of the Tethys Belt and the Circum-Pacific Metallogenic Belt,and is composed of the Northeastern Yunnan,Northwestern
基金supported by the Funds for the programs of the National Natural Science Foundation (Noes. 41572060, U1133602)Projects of YM Lab (2011)Innovation Team of Yunnan province and KMUST (2008,2012)
文摘1 Introduction The Lehonglead-zincdeposit is a large-sized Pb-Zn depositnewly found in recent years in the Sichuan-Yunnan-Guizhou Lead-zinc Poly-metallic Mineralization Area,which occurrenceis strictly
基金supported by the Key Program of the National Natural Science Foundation of China(No.u0837602)the Analysis Testing Foundation of Kunming University of Science and Technology(No.2010-303)
文摘The type, size, and compositions of fluid inclusions in a natural sphalerite were investigated and the total concentration of Zn released from the fluid inclusions was measured. To compare the total concentration of Zn released from the fluid inclusions with that dissolved from the sphalerite itself, dissolution experiments and theoretical calculations for the dissolution equilibrium of the sphalerite were also performed. The results indicate that large numbers of fluid inclusions with various sizes exist in the sphalerite, which can be divided into four types, i.e., pure gaseous inclusions, pure liquid inclusions, gas-liquid inclusions, and gas-liquid inclusions containing solid minerals. These inclusions were broken open during the grinding process, and their compositions were released to the solution. The total concentration of Zn released from these inclusions reaches 18.35×10^-6 mol/L, which is much higher than that of Zn dissolved from the sphalerite itself （1.93×10^-6 mol/L） and the theoretical calculation value （2.73×10^-8 mol/L）.
基金Funds for the Programs of the National Natural Science Foundation(Noes.41572060,U1133602)Projects of YM Lab(2011)Innovation Team of Yunnan province and KMUST(2008,2012)
文摘1 Introduction The Huize Zn-Pb district is located in the tectonic composite position,became one of the important production areas of zinc,lead and germanium in China.In the Huize lead-zinc deposit,the interlayer faults are most
