The Qiyugou explosive breccia type gold deposits of northwestern Songxian, Henan Province is situated at the East Qinling, on the southern margin of the North China Platform.The basement rocks are the Archean Taihua G...The Qiyugou explosive breccia type gold deposits of northwestern Songxian, Henan Province is situated at the East Qinling, on the southern margin of the North China Platform.The basement rocks are the Archean Taihua Group gneisses which were overlaid by the Proterozoic Xionger Group metaandesites. NW-and NE-trending folds and fractures are well developed. Nlagmatism of the Mid-Late Yanshan Epoch led to the formation of the Huashan granite batholith and a variety of acid/alkali dykes, meanwhile more than thirty explosive breccia bodies had been brought about. The most important deposit type is the explosive breccia type represented by the Qiyugou deposit, meanwhile there are structure fracture altered rock type,the goldbearing quartz vein type, as well as porphyry-breccia type. All these types are the terminal products of the evolution and differentiation of the syntectic magma originated from lower crust or upper mantle. They are controlled by a unified structural pattern occurred in the same展开更多
The Hongshijing gold deposit, which occurs in the Middle and Late Carboniferous volcanic and pyroclastic rocks, is of the brittle-ductile sh ear zone type controlled by a rift belt. The Hongshijing gold deposit is one...The Hongshijing gold deposit, which occurs in the Middle and Late Carboniferous volcanic and pyroclastic rocks, is of the brittle-ductile sh ear zone type controlled by a rift belt. The Hongshijing gold deposit is one con trolled by a brittle shear zone located in the Late Paleozoic rift zone. The alt ered-rock type and quartz type orebodies are contained in the gold-bearing for mation, which consists of basalt and tuffaceous sandstone. The major mineralizin g stage is at 267-261 Ma and reiteration mineralizing stage at 220-209 Ma.The or e minerals include pyrite, magnetite, copper, bornite, ferrohydrite, native gold , and the gangue minerals include quartz, sercite, calcite, Fe-dolomite, leucox ene, anorthose, biotite, baria, cajuelite, and agustite. The wall rock alteratio n associated with gold mineralization comprises silicification, carbonization, p yritization, sericitization and chloritization. The contents of gold are \{2.4\} ×10\+\{-9\} in the gold-bearing formation, \{5.7\}×10\+\{-9\} in the tuffaceo us sandstone and \{1.4\}-\{1.5\}×10\+\{-9\} in the basalt. Au is associated wit h Te, Se, Ni, Cu. Au=\{74.331\}×Te+\{0.0335\}×Ni-\{0.0211\}×Cu-\{2.650\}. Geo chemical investigations revealed that the mineralizing materials came from the b asalt and tuffaceous sandstone in the gold-bearing formation. Under the action of ductile brittle shear structure, the gold-bearing formation was metamorphose d and altered, and the ore-forming materials activated, migrated and mineralize d. The mineralizing fluid shows three mineralizing stages, with the characterist ics of middle to low temperature and middle to low mass fractions of NaCl .The fluid is of the Ca\+\{2+\}-Mg\+\{2+\}-Na\++- Cl\+- type and H\-2O-NaCl system. According to the data from hydrogen and oxyge n isotopic composition (δD=\{-114.6‰\}-\{-68.8‰\}, \{δ\{\}\+\{18\}O\-\{H\-2O \}\}=\{-2.47‰\}-\{5.91‰\}), the conclusion can be drawn that the mineralizing fluid of the Hongshijing gold deposit was a kind of mixed hydrothermal solution composed mainly of meteoric water , magmatic water and formation water in basalt and tuffaceous-sandstone or metamorphic water. The results show the mineralizi ng fluid and mineralizing materials came from the basalt and suffaceous-sandsto ne in the gold-bearing formation in Late Variscan orogeny. Under the action of brittle shearing, the gold-bearing formation was metamorphosed and altered, and the ore-forming material activated, migrated and mineralized with T and P going down and changes in pH, Eh, f\-\{O\-2\} an d f\-\{S\-2\} under the earth’s surface from \{1.57\} to \{2.25\} k m.展开更多
The Heilangou gold deposit is located in the northern QixiaePenglai gold belt, which is one amongst the three large gold belts in the eastern Shandong Province （Jiaodong Peninsula）. The ore body has formed within th...The Heilangou gold deposit is located in the northern QixiaePenglai gold belt, which is one amongst the three large gold belts in the eastern Shandong Province （Jiaodong Peninsula）. The ore body has formed within the Guojialing granite. In this study, we report the mineral chemistry of pyrite, as well as the S, Pb, and HeO isotope data of the Heilangou gold deposit. The chemical composition of pyrite in the Heilangou gold deposit indicates that the associated gold deposit is a typical magmatic hydrothermal one. The geochemical signatures and crystal structure of pyrite show that the ore-forming materials have been derived from the crust. The S isotope data of the pyrites from Heilangou show an overall range from 5.5 to 7.8＆amp;and an average of 6.7＆amp;. The S isotope data in this deposit are similar to those from the deposits in the Jiaodong gold belt. The Pb and S isotope variations are small in the Heilangou gold deposit. The 206Pb/204Pb, 207Pb/204Pb and 208Pb/204Pb ratios are 17.4653e17.5958, 15.5105e15.5746 and 38.0749e38.4361, respec-tively. These data plot between the lower crust and the orogenic belt. The Pb isotope data in the Heilangou gold deposit are similar to those in the Linglong gold deposit. From the Qixia gold area （the Liukou and Majiayao gold deposits） to the MupingeRushan gold belt （Rushan gold deposit） to the ZhaoeYe gold belt （the Linglong, Sanshandao and Jiaojia gold deposits）, the 206Pb/204Pb ratios progressively increase. The DeO isotope data obtained from quartz separates suggest that the ore-forming fluid was similar to a mixture of magmatic and meteoric waters. These results suggest that the ore-forming elements were primarily from source fluids derived from the lower crust.展开更多
The Shaxi porphyry copper (gold) deposits are a typical example of porphyry copper deposits associated with diorite in eastern China. Quartz diorite, which hosts the deposits, has a Rb-Sr isochron age of 127.9 ± ...The Shaxi porphyry copper (gold) deposits are a typical example of porphyry copper deposits associated with diorite in eastern China. Quartz diorite, which hosts the deposits, has a Rb-Sr isochron age of 127.9 ± 1.6 Ma. Geochemically, the rock is rich in alkalis (especially sodium), light rare earth elements (LREE) and large-ion lithophile elements (LILE), and has a relatively low initial strontium isotopic ratio (Isr=0.7058); thus it is the product of differentiation of crust-mantle mixing source magma. The model of alteration and mineralization zoning is similar to the Hollister (1974) diorite model. The ore fluids have a relatively high salinity and contain significant amounts of CO2, Ca2+, Na+ and ***CI?. The homogenization temperatures of fluid inclusions for the main mineralization stage range from 280 to 420°C, the δ18O values of the ore fluids vary from 3.51 to 5.52 %, the δD values are in the range between ?82.4 and ?59.8 %, the δ34S values of sulphides vary from ?0.3 to 2.49 %, and the δ13C values of CO2 in inclusions range between ?2.66 and ?6.53 %. Isotope data indicate that the hydrothermal ore fluids and ore substances of the Shaxi porphyry copper (gold) deposits were mainly derived from magmatic systems.展开更多
The Getang is a representative Carlin-type gold deposit in Southwest China.It has a proven reserve of about 30 tonnes at an average grade of 5.1 g/t Au.The orebodies occur as strat-abound lenses,and are structurally c...The Getang is a representative Carlin-type gold deposit in Southwest China.It has a proven reserve of about 30 tonnes at an average grade of 5.1 g/t Au.The orebodies occur as strat-abound lenses,and are structurally controlled by shallow NWW-and NE-trending fold-fault systems and the unconformity between the Upper and Middle Permian.In this study,the regional-and deposit-scale structural investigations,joints and finite strain measurements,and stress and dynamic analysis were conducted with an aim to reveal the structural process of the Getang gold deposit and clarify the relationship between the gold mineralization and structures.Three phases of deformation were identified in the deposit:(1)paleokarst was generated by a crustal uplift when the Youjiang Basin experienced extension at the end of the Middle Permian,laying the foundation for the unconformity;(2)the NW-trending structures were formed under a NNE-SSW compression during the Indochina-South China collision(Indosinian orogeny)in Triassic;(3)the NE-trending structures were generated or reactivated under a NW-SE-oriented compression during the Yanshanian intracontinental orogeny.The unconformity recorded two episodes of tectonic evolution in the NNE-SSW and NW-SE directions.Structural analyses and geochronology data suggest that the Getang gold deposit was formed as a result of tectonic transition from compression to extension during the Yanshanian intracontinental orogeny.展开更多
文摘The Qiyugou explosive breccia type gold deposits of northwestern Songxian, Henan Province is situated at the East Qinling, on the southern margin of the North China Platform.The basement rocks are the Archean Taihua Group gneisses which were overlaid by the Proterozoic Xionger Group metaandesites. NW-and NE-trending folds and fractures are well developed. Nlagmatism of the Mid-Late Yanshan Epoch led to the formation of the Huashan granite batholith and a variety of acid/alkali dykes, meanwhile more than thirty explosive breccia bodies had been brought about. The most important deposit type is the explosive breccia type represented by the Qiyugou deposit, meanwhile there are structure fracture altered rock type,the goldbearing quartz vein type, as well as porphyry-breccia type. All these types are the terminal products of the evolution and differentiation of the syntectic magma originated from lower crust or upper mantle. They are controlled by a unified structural pattern occurred in the same
文摘The Hongshijing gold deposit, which occurs in the Middle and Late Carboniferous volcanic and pyroclastic rocks, is of the brittle-ductile sh ear zone type controlled by a rift belt. The Hongshijing gold deposit is one con trolled by a brittle shear zone located in the Late Paleozoic rift zone. The alt ered-rock type and quartz type orebodies are contained in the gold-bearing for mation, which consists of basalt and tuffaceous sandstone. The major mineralizin g stage is at 267-261 Ma and reiteration mineralizing stage at 220-209 Ma.The or e minerals include pyrite, magnetite, copper, bornite, ferrohydrite, native gold , and the gangue minerals include quartz, sercite, calcite, Fe-dolomite, leucox ene, anorthose, biotite, baria, cajuelite, and agustite. The wall rock alteratio n associated with gold mineralization comprises silicification, carbonization, p yritization, sericitization and chloritization. The contents of gold are \{2.4\} ×10\+\{-9\} in the gold-bearing formation, \{5.7\}×10\+\{-9\} in the tuffaceo us sandstone and \{1.4\}-\{1.5\}×10\+\{-9\} in the basalt. Au is associated wit h Te, Se, Ni, Cu. Au=\{74.331\}×Te+\{0.0335\}×Ni-\{0.0211\}×Cu-\{2.650\}. Geo chemical investigations revealed that the mineralizing materials came from the b asalt and tuffaceous sandstone in the gold-bearing formation. Under the action of ductile brittle shear structure, the gold-bearing formation was metamorphose d and altered, and the ore-forming materials activated, migrated and mineralize d. The mineralizing fluid shows three mineralizing stages, with the characterist ics of middle to low temperature and middle to low mass fractions of NaCl .The fluid is of the Ca\+\{2+\}-Mg\+\{2+\}-Na\++- Cl\+- type and H\-2O-NaCl system. According to the data from hydrogen and oxyge n isotopic composition (δD=\{-114.6‰\}-\{-68.8‰\}, \{δ\{\}\+\{18\}O\-\{H\-2O \}\}=\{-2.47‰\}-\{5.91‰\}), the conclusion can be drawn that the mineralizing fluid of the Hongshijing gold deposit was a kind of mixed hydrothermal solution composed mainly of meteoric water , magmatic water and formation water in basalt and tuffaceous-sandstone or metamorphic water. The results show the mineralizi ng fluid and mineralizing materials came from the basalt and suffaceous-sandsto ne in the gold-bearing formation in Late Variscan orogeny. Under the action of brittle shearing, the gold-bearing formation was metamorphosed and altered, and the ore-forming material activated, migrated and mineralized with T and P going down and changes in pH, Eh, f\-\{O\-2\} an d f\-\{S\-2\} under the earth’s surface from \{1.57\} to \{2.25\} k m.
基金funded by National Natural Science Foundation Major Research Plan Key Support Project (Grant No. 90914002)the Xinyang Normal University high-level talented person start-up project in China
文摘The Heilangou gold deposit is located in the northern QixiaePenglai gold belt, which is one amongst the three large gold belts in the eastern Shandong Province （Jiaodong Peninsula）. The ore body has formed within the Guojialing granite. In this study, we report the mineral chemistry of pyrite, as well as the S, Pb, and HeO isotope data of the Heilangou gold deposit. The chemical composition of pyrite in the Heilangou gold deposit indicates that the associated gold deposit is a typical magmatic hydrothermal one. The geochemical signatures and crystal structure of pyrite show that the ore-forming materials have been derived from the crust. The S isotope data of the pyrites from Heilangou show an overall range from 5.5 to 7.8＆amp;and an average of 6.7＆amp;. The S isotope data in this deposit are similar to those from the deposits in the Jiaodong gold belt. The Pb and S isotope variations are small in the Heilangou gold deposit. The 206Pb/204Pb, 207Pb/204Pb and 208Pb/204Pb ratios are 17.4653e17.5958, 15.5105e15.5746 and 38.0749e38.4361, respec-tively. These data plot between the lower crust and the orogenic belt. The Pb isotope data in the Heilangou gold deposit are similar to those in the Linglong gold deposit. From the Qixia gold area （the Liukou and Majiayao gold deposits） to the MupingeRushan gold belt （Rushan gold deposit） to the ZhaoeYe gold belt （the Linglong, Sanshandao and Jiaojia gold deposits）, the 206Pb/204Pb ratios progressively increase. The DeO isotope data obtained from quartz separates suggest that the ore-forming fluid was similar to a mixture of magmatic and meteoric waters. These results suggest that the ore-forming elements were primarily from source fluids derived from the lower crust.
文摘The Shaxi porphyry copper (gold) deposits are a typical example of porphyry copper deposits associated with diorite in eastern China. Quartz diorite, which hosts the deposits, has a Rb-Sr isochron age of 127.9 ± 1.6 Ma. Geochemically, the rock is rich in alkalis (especially sodium), light rare earth elements (LREE) and large-ion lithophile elements (LILE), and has a relatively low initial strontium isotopic ratio (Isr=0.7058); thus it is the product of differentiation of crust-mantle mixing source magma. The model of alteration and mineralization zoning is similar to the Hollister (1974) diorite model. The ore fluids have a relatively high salinity and contain significant amounts of CO2, Ca2+, Na+ and ***CI?. The homogenization temperatures of fluid inclusions for the main mineralization stage range from 280 to 420°C, the δ18O values of the ore fluids vary from 3.51 to 5.52 %, the δD values are in the range between ?82.4 and ?59.8 %, the δ34S values of sulphides vary from ?0.3 to 2.49 %, and the δ13C values of CO2 in inclusions range between ?2.66 and ?6.53 %. Isotope data indicate that the hydrothermal ore fluids and ore substances of the Shaxi porphyry copper (gold) deposits were mainly derived from magmatic systems.
基金supported by the National Natural Science Foundation of China(Nos.42072091,41972206)the Hubei Provincial Natural Science Foundation Joint Project(No.2023AFD210)the China Geological Survey(Nos.12120115036201,DD20190443).
文摘The Getang is a representative Carlin-type gold deposit in Southwest China.It has a proven reserve of about 30 tonnes at an average grade of 5.1 g/t Au.The orebodies occur as strat-abound lenses,and are structurally controlled by shallow NWW-and NE-trending fold-fault systems and the unconformity between the Upper and Middle Permian.In this study,the regional-and deposit-scale structural investigations,joints and finite strain measurements,and stress and dynamic analysis were conducted with an aim to reveal the structural process of the Getang gold deposit and clarify the relationship between the gold mineralization and structures.Three phases of deformation were identified in the deposit:(1)paleokarst was generated by a crustal uplift when the Youjiang Basin experienced extension at the end of the Middle Permian,laying the foundation for the unconformity;(2)the NW-trending structures were formed under a NNE-SSW compression during the Indochina-South China collision(Indosinian orogeny)in Triassic;(3)the NE-trending structures were generated or reactivated under a NW-SE-oriented compression during the Yanshanian intracontinental orogeny.The unconformity recorded two episodes of tectonic evolution in the NNE-SSW and NW-SE directions.Structural analyses and geochronology data suggest that the Getang gold deposit was formed as a result of tectonic transition from compression to extension during the Yanshanian intracontinental orogeny.
