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1.
根据鞍本地区包裹体研究试论弓长岭磁铁富矿的成因   总被引：5，自引：0，他引：5  
Gongchangling high-grade magnetite ores,which constitute one of the major rich from deposits in China,occur in the BIF .of the Anshan-Group in Precambrian metamorphic rocks.But its origin has long been a controversial problem,although most researchers are in favour of the eoncept that it is genetically related to hydrothermal process connected with migmatite.On the basis of field observation,this problem has been dealt with in this paper in the light of fluid inclusion studies.The results show that hydrothermal activity,was widespread in this region,which can be divided into two stages.The late stage hydrothermal activity was intensively developed around rich iron dposits.The formation temperature of the late stage hydrbthermal fluids is in the range of 487- 505℃,and they are slightly alkaline with a salinity of 13.2-28.1 wt%,consisting mainly of Na^ ,Ca^ ,Cl^-,So4^-,etc.As revetled by temperature measurements,the formation temperatures of fluid inclusions are quite uniform from,place to place within the vast areas in this region,and the comparason of these temperatures between rich ores and migmatite and wall rocks indieates that the late hydrothermal fluids are of metamorphie origin.The authors suggest that the rich magnetite ores in the Gongchangling Range seem to be the result of the reworking process(alteration)by metamorphie hydrothermal fluids in response to regional metamorphism on some sedimentary ore deposits that were originally relatively rich in iron.  相似文献   

2.
Presented in this paper are Sm-Nd isotope and major, trace and rare-earth element analyses of bimodal volcanic rocks of the Shilu Group and other stratigraphic units in northwestern Hainan Is-land ,South China. It is shown that there are some N-MORB-type basalts(spilites) in the western part of the bimodal volcanic belt, in addition to some E-MORB-type and initial rift-type tholeiites (IRT) in th emiddle and eastern parts.Sm-Nd model ages of these basalts range from 545 Ma to 460Ma .The other extremes of the bimodal volcanics are porphyritic quartz rhyolites, which are characteristic of crustal material source.Sm-Nd model ages of the rhyolites range from 1562 Ma to 1371 Ma .The bimodal volcanic rocks are almost distributed in fifts or faulted depressions,as well as in the Upper Paleozoic rift of Hainan Island.Tholeiites of the Shilu Group can be compared with Cenozoic basalts in the middle and south-ern parts of the Red Sea Rift Belt in petrology, elemental geochemistry and Sm-Nd isotope geology. Shilu iron ores are closely associated with N-MORB-type basalts located in the western bimodal vol-canic belt.It is very interesting to note that the Shilu Fe-Co-Cu deposit can also be compared with Atlantis II Deep in the Red Sea Rift Belt.Therefore ,the present authors believe that the Shilu depos-it is a kind of hydrothermal deposit related to ocean volcanic belt ,where the geotectonic setting be-longs to initial extensional rifts in the oceanic crust.On the other hand, the largest Fe-Co-Cu ore de-posit in China used to be influenced by Hercynian granites after mineralization ,as is clearly observed on both εNd(T)-1/Nd and εNd(T)-^147Sm/^144Nd diagrams.  相似文献   

3.
The Changkeng gold-silver deposits consist of a sediment-hosted, disseminated gold deposit and a replacement-type silver deposit. The mineralizations of gold and silver are zoned and closely related to the silicification of carbonate and clastic rocks, so that siliceous ores dominate in the deposit. The mineralizing temperature ranges mainly from 300 to 170℃, and K+, Na+, Ca2+, Mg2+, and Cl- are the major ions in the ore-forming fluid. Calculations of distribution of metal complexes show that gold is mainly transported by hydrosulphide complexes, but chloride complexes of silver, iron, lead, and zinc, which are transformed into hydroxyl and hydrosulphide complexes under neutral to weak-alkaline circumstances in the late stage, predominate in the ore-forming solutions. Water-rock interaction is confirmed to be the effective mechanism for the formation of silver ores by computer modelling of reaction of hydrothermal solution with carbonate rocks. The solubility analyses demonstrate that the precipitation  相似文献   

4.
The Dongshengmiao Pb-Zn deposit located in the Mesoproterozoic aulacogen in a passive continental margin in the north- west margin of the North-China Craton is widely considered to be a untypical SEDEX deposit.Recently,new types of mineralization such as chalcopyrite veins and re-crystallized sphalerite ores with visible hydrothermal alteration have been found in the deposit at depth.In this paper we report the decrepitation temperatures of fluid inclusions in chalcopyrite,sphalerite and quartz from these new types of ores.The decrepitation temperatures of fluid inclusions in chalcopyrite(4 samples),sphalerite(2 samples)and quartz(5 samples)are 303～456℃,97～497℃,146～350℃and 350～556℃,respectively.The decrepitation temperatures of fluid inclusions in the vein-type chalcopyrite are similar to the decrepitation temperatures of fluid inclusions in chalcopyrite from the Hercynian Oubulage porphyry Cu-Au deposit(313～514℃)and the Chehugou porphyry Cu-Mo deposit(277～485℃),supporting our interpretation that the Dongshengmiao deposit was overprinted by magmatic hydrothermal mineralization.The decrepitation temperatures of fluid inclusions in re-crystallized sphalerite from the Dongshengmiao deposit are characterized by two peaks,97～358℃and 358～497℃.The decrepitation temperatures of fluid inclusions in quartz in ehalcopyrite veins from the Dongshengmiao deposit are also characterized by two peaks,146～350℃and 350～556℃.The lower and higher temperature peaks in both cases are considered to represent two separate mineralization events,original SEDEX mineralization and magmatic hydrothermal overprinting,respectively.The higher decrepitation temperatures of fluid inclusions in quartz and sphalerite from the Dongshengmiao deposit are similar to the decrepitation temperatures(340～526℃)of fluid inclusions in sphalerite from the Baiyinnuoer skarn-type Pb-Zn deposit in the region. Replacement of pyrite by sphalerite and overgrowth of chalcopyrite on pyrite in the Dongshengmiao support our interpretation that the original SEDEX mineralization was overprinted by magmatic hydrothermal activity in the deposit.Our results suggest that there may be separate porphyry and skarn-type deposits related to Hercynian magmatism and associated hydrothermal activities in the Langshan area, which are potential exploration targets in the future.  相似文献   

5.
Long-standing controversy persists over the presence and role of iron–rich melts in the formation of volcanic rock-hosted iron deposits. Conjugate iron–rich and silica–rich melt inclusions observed in thin-sections are considered as direct evidence for the presence of iron-rich melt, yet unequivocal outcrop-scale evidence of iron-rich melts are still lacking in volcanic rock-hosted iron deposits. Submarine volcanic rock-hosted iron deposits, which are mainly distributed in the western and eastern Tianshan Mountains in Xinjiang, are important resources of iron ores in China, but it remains unclear whether iron-rich melts have played a role in the mineralization of such iron ores. In this study, we observed abundant iron-rich agglomerates in the brecciated andesite lava of the Heijianshan submarine volcanic rock–hosted iron deposit, Eastern Tianshan, China. The iron-rich agglomerates occur as irregular and angular masses filling fractures of the host brecciated andesite lava. They show concentric potassic alteration with silicification or epidotization rims, indicative of their formation after the wall rocks. The iron-rich agglomerates have porphyritic and hyalopilitic textures, and locally display chilled margins in the contact zone with the host rocks. These features cannot be explained by hydrothermal replacement of wall rocks(brecciated andesite lava) which is free of vesicle and amygdale, rather they indicate direct crystallization of the iron-rich agglomerates from iron-rich melts. We propose that the iron-rich agglomerates were formed by open-space filling of volatile-rich iron-rich melt in fractures of the brecciated andesite lava. The iron-rich agglomerates are compositionally similar to the wall-rock brecciated andesite lava, but have much larger variation. Based on mineral assemblages, the iron-rich agglomerates are subdivided into five types, i.e., albite-magnetite type, albite-K-feldsparmagnetite type, K-feldspar–magnetite type, epidote-magnetite type and quartz-magnetite type, representing that products formed at different stages during the evolution of a magmatic-hydrothermal system. The albite-magnetite type represents the earliest crystallization product from a residual ironrich melt; the albite-K-feldspar-magnetite and K-feldspar-magnetite types show features of magmatichydrothermal transition, whereas the epidote-magnetite and quartz-magnetite types represent products of hydrothermal alteration. The occurrence of iron-rich agglomerates provides macroscopic evidence for the presence of iron-rich melts in the mineralization of the Heijianshan iron deposit. It also indicates that iron mineralization of submarine volcanic rock-hosted iron deposits is genetically related to hydrothermal fluids derived from iron-rich melts.  相似文献   

6.
In this paper the authors present the REE concentrations and Sr and Nd isotopic compositions of fluorites from the Bailashui tin deposit of the Furong ore field, southern Hunan Province. The results showed that the total amount of REE in fluorites is usually low, ranging from 0.705 to 8.785 μg/g with the chondrite-normalized REE distribution patterns similar to those of the Qitianling granites in the study area, characterized by LREE-enrichment patterns with pronounced negative Eu anomalies. The fluorites vary in Sr isotopic composition within the range of 0.7083-0.7091, the values are lower than those of the granites and higher than those of the host carbonate rocks in this area. The εNd（t） values of fluorites vary between -9.4 and ＋10.3, revealing that both the crust- and mantle-source materials were involved in the ore-forming hydrothermal fluids. Combined with previous studies on this ore deposit, the Bailashui tin deposit is temporally and spatially closely related with granitic magmatism in this area. The hydrothermal fluorites are the product of fluid/rock interactions between granitic magmatic hydrothermal fluid and marine carbonate rocks. The REE and F in the ore-forming fluid were derived from the granites, whereas Sr in the ore-forming fluid came mainly from the granitic magmatic hydrothermal fluid and marine carbonate rocks, although variations in Sr isotopic composition cannot be explained by a simple mixture of these two end-members. Evidence demonstrated that the ore-forming fluids are of crustal-mantle mixing origin, but that the fluids were probably incompletely homogenized and this may be caused by inhomogeneous mixing of the fluids of different sources.  相似文献   

7.
The iron deposit of Zaoanzhnang type occurs in the ultrabasie unit od a late Archaean greenstone belt. It is a late magmatic apatite-titanomagnetite deposit, subusequently enriched by hydrothermal superimposition and regional metamorphism. This deposit is extremely complex in mineralogy, containing 87 kinds of minerals charaeteristie of ultrabasie-alkaline complexes. Mineralization of iron, titanium and phosphorus took place mainly during the magmatic stage, while that of uranium and thorium during the pnenmatolytic-hydrothermal stage.  相似文献   

8.
The Gaoshan gold-silver deposit, located between the Yuyao-Lishui Fault and JiangshanShaoxing fault in Longquan Area, occurs in the Suichang-Longquan gold-silver polymetallic metallogenic belt. This study conducted an investigation for ore-forming fluids using microthermometry, D-O isotope and trace element. The results show that two types of fluid inclusions involved into the formation of the deposit are pure liquid phase and gas-liquid phase aqueous inclusions. The homogenization temperature and salinity of major mineralization phase ranges from 156°C to 236°C(average 200°C) and 0.35% to 8.68%(NaCleqv)(average 3.68%), respectively, indicating that the ore-forming fluid is characteristic of low temperature and low salinity. The oreforming pressure ranges between in 118.02 to 232.13'105 pa, and it is estabmiated that the oreforming depth ranges from 0.39 to 0.77 km, indicating it is a hypabyssal deposit in genesis. The low rare earth elements content in pyrites, widely developed fluorite in late ore-forming stage and lack of chlorargyrite(Ag Cl), indicates that the ore-forming fluid is rich in F rather than Cl. The ratios of Y/Ho, Zr/Hf and Nb/Ta of between different samples have little difference, indicating that the later hydrothermal activities had no effects on the former hydrothermal fluid. The chondrite-normalized REE patterns of pyrites from country rocks and ore veins are basically identical, with the characteristics of light REE enrichment and negative Eu anomalies, implying that the ore-forming fluid was oxidative and derived partly from the country rocks. The δD and δ18O of fluid inclusions in quartz formed during the main metallogenic stage range from -105‰ to -69 ‰ and -6.01‰ to -3.81‰, respectively. The D-O isotopic diagram shows that the metallogenic fluid is characterized by the mixing of formation water and meteoric water, without involvement of magmatic water. The geological and geochemical characteristics of the Gaoshan gold-silver deposit are similar to those of continental volcanic hydrothermal deposit, and could be assigned to the continental volcanic hydrothermal gold-silver deposit type.  相似文献   

9.
The Dahongshan Fe-Cu (-Au) deposit is a superlarge deposit in the Kangdian metallogenic belt, southwestern China, comprising approximately 458 Mt of Fe ores (40% Fe) and 1.35 Mt Cu. Two main types of Fe-Cu (-Au) mineralization are present in the Dahongshan deposit: (1) early submarine volcanic exhalation and sedimentary mineralization characterized by strata-bound fine-grained magnetite and banded Fe-Cu sulfide (pyrite and chalcopyrite) hosted in the Na-rich metavolcanic rocks; (2) late hydrothermal (-vein) type mineralization characterized by Fe-Cu sulfide veins in the hosted strata or massive coarse-grained magnetite orebodies controlled by faults. While previous studies have focused primarily on the early submarine volcanic and sedimentary mineralization of the deposit, data related to late hydrothermal mineralization is lacking. In order to establish the metallogenic age and ore-forming material source of the late hydrothermal (-vein) type mineralization, this paper reports the Re-Os dating of molybdenite from the late hydrothermal vein Fe-Cu orebody and H, O, S, and Pb isotopic compositions of the hydrothermal quartz-sulfide veins. The primary aim of this study was to establish the metallogenic age and ore-forming material source of the hydrothermal type orebody. Results show that the molybdenite separated from quartz-sulfide veins has a Re-Os isochron age of 831 ± 11 Ma, indicating that the Dahongshan Fe-Cu deposit experienced hydrothermal superimposed mineralization in Neoproterozoic. The molybdenite has a Re concentration of 99.7–382.4 ppm, indicating that the Re of the hydrothermal vein ores were primarily derived from the mantle. The δ34S values of sulfides from the hydrothermal ores are 2‰–8‰ showing multi-peak tower distribution, suggesting that S in the ore-forming period was primarily derived from magma and partially from calcareous sedimentary rock. Furthermore, the abundance of radioactive Pb increased significantly from ore-bearing strata to layered and hydrothermal vein ores, which may be related to the later hydrothermal transformation. The composition of H and O isotopes within the hydrothermal quartz indicates that the ore-forming fluid is a mixture of magmatic water and a small quantity of water. These results further indicate that the late hydrothermal orebodies were formed by the Neoproterozoic magmatic hydrothermal event, which might be related to the breakup of the Rodinia supercontinent. Mantle derived magmatic hydrothermal fluid extracted ore-forming materials from the metavolcanic rocks of Dahongshan Group and formed the hydrothermal (-vein) type Fe-Cu orebodies by filling and metasomatism.  相似文献   

10.
李绍柄 《地球化学》1979,(2):170-177
Graphite has been identified for the first time from rich magnetite ores in Gongehangling,Northeast China.It is suggested that the deposit is originated from siderite of sedimentary origin through regional metamorphism.In view of the unique charaeteristics of its geologieal setting and mineral assemblage this deposit should be elassified as a new type in China  相似文献   

11.
鞍山弓长岭富磁铁矿床的形成机制和物理化学条件研究   总被引：5，自引：0，他引：5  
赵斌  李统锦 《地球化学》1980,(4):333-344
Field observation and results of experimental studies show that Gongchangling rich iron deposit is characterized by multigenesis as a result of repetition of differcnt geological processes. It probably resulted from the infiltration of silica under the influence of aqueous solutions derived from migmatite-granite. Because the formation of rich iron deposit was accompanied by the formation of skarn minerals and the transformation of sedimont-metamorphie poor iron deposits, characteristics of both skarn deposits and strata-bound ore deposits ean therefore be recognized. Experimental data indicate that physico-chemical parameters of formation of rich iron deposit are P =2kbar, T = 500--600℃, pH= 8--10, and fo2 = 10^-25 bar.  相似文献   

12.
The Daliangzi Pb-Zn deposit is a large deposit hosted in the Sinian Dengying Formation dolostone, located in the Sichuan-Yunnan-Guizhou ore concentration area. Ore minerals are mianly sphalerite, galena, and gangue minerals consist of dolomite, quartz and calcite. The metallogenic stages may be divided into sphalerite-pyrite-carbon stage, sphalerite-galena stage and galena-chalcopyrite-carbonate stage. The ore-forming fluid is basin brine, which is characterized by medium-low temperature of 117.5 ℃ to 320.3 ℃ and medium salinity of 5.11% NaCleqv to 18.96% NaCleqv, moreover, the abundant CH4 and pitch in the fluid inclusions indicate that the participation of organic matter in the mineralization. The δ13CV-PDB and δ18OSMOW values of the Dengying Formation dolostone are similar to that of marine carbonate, revealing that the dolostone belongs to marine carbonate. Both the δ13CV-PDB and δ18OSMOW values of hydrothermal calcites are lower than that of the Dengying Formation dolostone, which may result from dissolution of the Dengying Formation dolostone. The δ34S values of ore minerals are mainly in the range of 9.8‰-20.8‰, indicating the sulfur may come from thermochemical reduction of marine sulfate in the Dengying Formation. The 207Pb/204Pb versus 206Pb/204Pb diagram manifests that Pb is crustal origin, and likely comes mainly from the wall rocks and less from the basement. (87Sr/86Sr)i ratios of sphalerites and hydrothermal calcite are higher than that of the Dengying Formation dolostone, indicating that the ore-forming fluid flew through the basement. In conclusion, the ore-forming fluid was basin brine, which extracted the metallogenic materials, Pb and Zn, from the basement and wall rocks. When the ore-forming fluid reached the "black fractured zones", carbonized tectonic breccia zone, S2- was produced by the thermochemical reduction reaction under the influence of the organic matter, and interaction between the S2- and Pb2+, Zn2+, resulted in the precipitation of ore metals. © 2018, Science Press. All right reserved.  相似文献   

13.
The Dajiangping pyrite deposit located in the middle sector of the Yunkai uplift in western Guangdong is a stratiform sulphide deposit occurring in Sinian marine clastic and fine clastic rocks. The formation of the deposit was related to submarine exhalation and hot brine deposition. A part of it was reformed by late-stage hydrothermal solution. The δ34S values of pyrite vary from - 25.55‰ to +21.07‰, which are inversely proportional to the content of organic carbon in ore and pyrite. Passing from striped fine-grained pyrite ore to massive coarse-grained pyrite ore, i.e. from south to north, the sulphur isotopic composition changes from the light sulphur-enriched one to the heavy sulphur-enriched one. The lead isotopic composition of striped ore is consistent with that of the country rocks of orebodies and the lead is radiogenic lead derived from the upper crust. The lead isotopic composition of massive ore is relatively homogeneous and its 206Pb/204Pb, 207Pb/204Pb and 208Pb/204Pb ratios are a bit lo  相似文献   

14.
Auriferous quartz veins in the Bankuan gold deposit occur in the interlayer broken zone of the basal conglomerate of the Tietonggou Formation or at the unconformity between the Tietonggou Formation and the crystalline basement.The composition of fluid inclusions in the minerals indicates that the nature and composition of ore-forming hydrothermal solutions show a drastical change soon after the solutions reached the Tietonggou Formation from the crystalline basement,resulting in gold precipitation.So the Bankuan gold deposit can be assigned to the conglomerate stata-bound-type deposits.137 thermometric data are concentrated in the three ranges 400-340℃,330-220℃ and 180-160℃,representing three episodes of metalogenesis,Oxygen isotope studies demonstrate the evolution of ore-forming hydrothermal solutions from early metamorphic to late meteoric,Diversity of ore-forming materials dominated by deep-source material is supported by sulphur and lead isotope data.From the above discussions it may be concluded that the deposit formed by metamorphism induced as a result of Mesozoic northward intracontinental subduction along the Machaoying fault.  相似文献   

15.
A preliminary organic geochemical study shows that the sulphide ores from the hydrothermal deposit of the Okinawa Trough are generally low in the total organic carbon and extremely low in the soluble organic matter. In the aliphatic hydrocarbon fraction, the n-alkanes range from C15 to C35, with usual maxima in the middle n-C20 region and strong odd-carbon number predominance when n > C25 (CPI = 1.2). The dominant analog in the aromatic fraction is phenanthrene, a polynuclear aromatic hydrocarbon, which provides evidence for hydrothermal activity. The organic matter derived mainly from marine planktonic and terrigenous vascular plants is entrapped in a high-temperature regime such as an active chimney and cooled quickly in the sulphide ores on the seafloor. Organic matter and sulphides are definitely products of a high-temperature alteration. The biomarker compounds indicate that the ores are formed under low Eh and pH conditions-a reducing to anoxic environment, which is favourable for sulphates to be  相似文献   

16.
The Hadamengou gold deposit is located in western part of the northern margin of the North China craton. It is a hydrothermal deposit related to alkaline magmatism. Dissolution of Au, Fe from pyrite and iron oxide （including magnetite and hematite） individual minerals in the three main types of ore shows： in iron oxides （magnetite and hematite）, Au and Fe were dissolved simultaneously and their solubilities are positively correlated, which means Au is mainly chemical-bonded （lattice gold） and/or colloidal-adsorbed in iron oxides; while in pyrite, on the contrary, Au dissolution obviously lags behind Fe and the solubility of Au shows negative relationship with that of Fe, which indicates Au is mainly hosted as grains of elemental gold （or native gold） within pyrite. Previous studies revealed that the Hadamengou gold deposit is characterized by intensive K-feldspathization and holds high content of iron oxides occasionally replaced by sulfides, which was caused by oxidizing K-enriched alkaline fluids under a stretching geodynamic setting. These geological features, together with the high Au-content in iron oxides, comparable with that of the Olympic Dam deposit in South Australia, suggest that this deposit is the first example of iron oxide-type gold deposits in China.  相似文献   

17.
The Zhaceqiao gold-polymetal deposit was discovered recently in the Jiangnan Transitional Zone. In order to obtain the ore-forming age, sericite was separated from the altered granite porphyry which hosts the gold deposit. 40Ar-39Ar analyses of sericite in gold ore yield spectrum age of 156.9±1.6 Ma with the isochron age of 152±28 Ma. The spectrum age of sericite in altered granodiorite porphyry is 142.1±1.3 Ma with the isochron age of 137±13 Ma. The homogenization temperature of fluid inclusions in quartz from the Niutougaojia and Chengtan ore sections is c.a. 160℃. The H-O isotopic compositions indicate that the ore-forming fluids mainly come from magmatic hydrothermal sources. Integrating with regional studies, the Zhaceqiao gold deposit is predominantly characterized by shallow, low temperature and epithermal, similar to Carlin-like type gold deposit. The Zhaceqiao gold deposit was formed in Yanshanian through multi-stage superimposition. The gold mineralization was related to the ductile-brittle compressional tectonic deformation and alteration in middle Jurassic to gold, while the polymetallic mineralization was related to the Late Jurassic-Early Cretaceous igneous activity, and the epithermal mineralization in the middle and late stage of the Early Cretaceous. © 2017, Science Press. All right reserved.  相似文献   

18.
The Jinman copper deposit,which is situated on the northern margin of the Lanping-Simao back-arc basin,western Yunnan Province,is a silver-bearing,high-grade vein-type copper deposit.Comprehensive element geochemical studies of the host rocks and hydrothermal minerals revealed the regularities in the distribution,mobilization and transport of elements from the host rocks to hydrothermal minerals.In conjunction with the fluid inclusion and isotope data,it is suggested that the ore-forming fluid was derived mainly from a deep source characterized by CO2 enrichment and reduction in nature.It is also suggested that the oreforming materials come largely from a deep source.although the contribution of the country rocks should not be ruled out.It is also found that some hydrothermal minerals are possessed of MREE-enrichment patterns.It is deduced that the REEs in the deep-source ore fluid were transported in the form of CO3^2- complexes and were deposited in a continental basin(or a hot-spring basin).  相似文献   

19.
<正>In summary,field observations and detailed measurements suggest that the red-ribbon style iron-ore bodies in Xinyu iron deposit result from regional plastic flow and sausage bending,rather than fold superimposition.The Xinyu iron deposit,located in central Jiangxi Province,is one of the most important BIF-type deposits in China.It is hosted in the Late Proterozoic volcanicsedimentary rocks,which are composed of sericitechlorite pyhllite,magnetite-bearing chlorite phyllite or schist,magnetite quartzite,and schist(Yu et al.,1989;Zeng et al.,2011).The Xinyu iron orefield lies on the eastern side of the Wugong Shan uplift,to the north of the South China  相似文献   

20.
The Kengdenongshe deposit is a newly discovered large Au-Ag-Pb-Zn polymetallic deposit in the eastern Kunlun metallogenic belt, and the genetic relationship between Pb-Zn-rich ore bodies and Au-rich ore bodies in this deposit is controversial. Therefore, comparative studies of mineralization, alteration, and fluid inclusions in the two types of ore bodies were carried out with the statistical analysis of the correlation among ore-forming elements of Au, Ag, Pb and Zn. The results show that, from north to south, the mineralization changes gradually from Pb-Zn-rich to Au-rich with the wall-rock alteration from silicification-epidotization to baritization-marbleization-silicification. In addition, the structures of Pb-Zn-rich ores indicate a hydrothermal sedimentary origin with the late hydrothermal superposition, while those of Au-rich ores show features of hydrothermal origin. Besides, based on the study of fluid inclusions in this mining area, the ore-forming fluid of Pb-Zn-rich ores is low temperature (focus on 150-170°C) and low-medium salinity (1.74%-10.24% NaCleqv), while that of Au-rich ores displays low-medium temperature (manily 130-250°C) with low-medium salinity (0.35%-10.24% NaCleqv). Pb-Zn and Au-Ag show positive correlation (correlation coefficient r>0.25), but Au is poorly correlated with Pb and Zn (correlation coefficient r<0.15). However, to due to the late stage hydrothermal superimposition, Au is rather well correlated with Pb in high grade ores. In summary, there may exist two epochs of mineralization in the Kengdenongshe polymetallic deposit. The early one is Pb-Zn mineralization stage with characteristics of hydrothermal sedimentary origin, and the ore-forming fluid may be derived from the mixture of magmatic water and seawater. While the later one is Au mineralization stage, having characteristics of hydrothermal origin with subsequent hydrothermal superimpositions, and the ore-forming fluid is mainly derived from magmatic water that mixed with meteoric water. © 2018, Science Press. All right reserved.  相似文献   

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