The compositions of REE in quartz and pyrite from the main stage of the Laowan gold deposit in Henan Province and that in quartz from Laowan granite were determined by inductively coupled plasma-mass-spectrometry (IC...The compositions of REE in quartz and pyrite from the main stage of the Laowan gold deposit in Henan Province and that in quartz from Laowan granite were determined by inductively coupled plasma-mass-spectrometry (ICP-MS) to trace the source of ore-forming materials. Meanwhile, the REE compositions of the deposit ore, granite and metamorphic wall rock were also considered for comparative studies in detail. The range of ∑REE of quartz and pyrite from the deposit ores is 4.18 × 10^-6- 30.91 × 10^-6, the average of ∑REE is 13.39 × 10^-6, and the average of ∑REE of quartz in the Laowan granite is 6.68 × 10^-6. There is no distinct difference of REE parameters between the deposit ore quartz and granite quartz. The quartz in gold deposit has the same REE particular parameters as quartzes from Laowan granite, such as δEu, δCe, (La/Yb)N and (La/Sm)N, partition degree of LREE to HREE, especially, the chondrite-normalized REE patterns, but no similarity to those from metamorphic wall rock, which shows that ore-forming hydrothermal fluid is mainly the fluid coming from the Laowan granite magma, rather than metamorphic fluid. Meanwhile, comparison studies on REE features between minerals from the deposit ores and related geological bodies in the deposit show that REE characteristics of minerals can serve as an indicator of ore-forming fluid properties and sources, while the REE characteristics of the bulk samples (such as deposit ores, granites and wall rocks) can not trace the source of the ore-forming materials exactly.展开更多
The compositions of REE in quartz and pyrite from main mineralized stage of the Laowan gold deposit in Henan province and that of quartz from Laowan granite were determined by Inductively Coupled Plasma-Mass-Spectrome...The compositions of REE in quartz and pyrite from main mineralized stage of the Laowan gold deposit in Henan province and that of quartz from Laowan granite were determined by Inductively Coupled Plasma-Mass-Spectrometry (ICP-MS). The REE of deposit ore of the Laowan gold deposit, wall-rock and Laowan granite also were studied to trace the source of metallogenic materials in Laowan gold deposit in detail. The range of ∑ REE in quartz and pyrite from gold deposit is 4.18 × 10^-6 - 30.91 × 10^-6, average of 13.39 × 10^-6, 6.68 × 10^-6 of the Laowan granite quartz, obviously lower to REE concentration of deposit, granite and wall-rock. The value of (La/ Yb)N and (La/Sm)N of ore minerals from the gold deposit is 13.23 and 4.17 respectively. The differences in REE parameters, such as δEu, δCe and diffusion degree in REE from light to heavy, among deposit ore minerals and granite mineral are weak. Especially, there are no differences between the chondrite-normalised REE curves of minerals from gold deposit and those of quartzs in Laowan granite, no similarity to wall-rock', which shows that ore-forming hydrothermal fluid mainly came from magma fluid resulting from the Laowan granite magma, metamorphic fluid in few. The results also show that REE characteristics of ore minerals in deposit are effective for disclosing oreforming fluid quality comparing with deposit ore'REE compositions.展开更多
Dexing copper deposit is the biggest porphyry copper deposit in China. By researching isotopes of C,Si and Cu from the samples of Tongchang and Fujiawu ore-field, the authors found that δ13CPDB values of siderite wer...Dexing copper deposit is the biggest porphyry copper deposit in China. By researching isotopes of C,Si and Cu from the samples of Tongchang and Fujiawu ore-field, the authors found that δ13CPDB values of siderite were close to the δ13CPDB value of original magma; δ30Si values of the samples at the ore-forming stage were close to the δ30Si value range of magma, δ30Si values of partial samples were far away from it; Cu isotopic compositions of massive chalcopyrite formed at the early ore-forming stage are higher than that of veinal chalcopyrite formed at the later ore-forming stage. The results show that ore-forming materials were mainly derived from the porphyry body, and part of them were from wall rock materials.展开更多
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 ...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 δ^(34)S 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.展开更多
Abstract This paper deals with characteristics of silicon isotope compositions and siliceous cathodoluminescence of host rocks, ores and hydrothermal silicified quartz of the Carlin-type ore deposits in the Yunnan-Gui...Abstract This paper deals with characteristics of silicon isotope compositions and siliceous cathodoluminescence of host rocks, ores and hydrothermal silicified quartz of the Carlin-type ore deposits in the Yunnan-Guizhou-Guangxi triangle area. The study shows that primary silicified quartz is nonluminescent but quartz in host rocks and secondary silicified quartz are luminescent by the action of cathode rays. Correspondingly, silicon isotope compositions of host rocks, ores and hydro6thermal quartz veins are clearly distinguished. In strata from the Middle Triassic to the “Dachang” host bed, δ30Si of the host rocks ranges from 0.0% ?0.3%, while that of primary ore-forming silicified fluids from ?0.1% to ?0.4%; in the Upper Permian and Lower Carboniferous strata and Indosinian diabase host beds, δ30Si of the host rocks is from ?0.1% to ?0.2% and that of the primary silicified quartz veins from 0.3 % ?0.5 %. This pattern demonstrates the following geochemical mineralization process, primary ore-forming siliceous fluids migrated upwards quickly along the main passages of deep-seated faults from mantle to crust and entered secondary faults where gold deposits were eventually formed as a result of permeation and replacement of the siliceous ore-forming fluids into different ore-bearing strata. This gives important evidence for the fact that ore-forming fluids of this type of gold deposits were mainly derived from upper mantle differentiation and shows good prospects for deep gold deposits and geochemical background for large and superlarge gold deposits.展开更多
The Jinshan gold deposit is located in the Northeast Jiangxi province,South China,which related to the ductile shear zone.It contains two ore types,i.e.the alteration-type ore and the goldbearing quartz vein ore.Rb-Sr...The Jinshan gold deposit is located in the Northeast Jiangxi province,South China,which related to the ductile shear zone.It contains two ore types,i.e.the alteration-type ore and the goldbearing quartz vein ore.Rb-Sr age dating is applied to both gold-bearing pyrite in the alteration-type ore and fluid inclusion in the gold-bearing quartz vein to make clear the time of the gold mineralization of the Jinshan deposit.Analytical results of this study yielded that the age of the alteration-type ore bodies is about 838±110Ma,with an initial 87Sr/86Sr value of 0.7045±0.0020.However,the age of the gold-bearing quartz vein-type ore is about 379±49Ma,and the initial 87Sr/86Sr is 0.7138±0.0011.Based on the age data from this work and many previous studies,the authors consider that the Jinshan gold deposit is a product of multi-staged mineralization,which may include the Jinninian,Caledonian,Hercynian,and Yanshanian Periods.Among them,the Jinninian Period and the Hercynian Period might be the two most important ore-forming periods for Jinshan deposit.The Jinninian Period is the main stage for the formation of alteration-type ore bodies,while the Hercynian Period is the major time for ore bodies of gold-bearing quartz vein type.The initial values of the 87Sr/86Sr from this study,as well as the previous isotope and trace element studies,indicate that the ore-forming materials mainly derived from the metamorphic wall rocks,and the ore-forming fluids mainly originated from the deep metamorphic water.展开更多
Based on the main characteristics of the tectonic -magmatic evolution of region and Tanlu fault zone,we have discussed ore-bearing magmatic rocks petrochemistry,strontium and lead isotope,and the source of ore-forming...Based on the main characteristics of the tectonic -magmatic evolution of region and Tanlu fault zone,we have discussed ore-bearing magmatic rocks petrochemistry,strontium and lead isotope,and the source of ore-forming materials in Yinan skarn deposit in this paper.The petrochemical features show that the ore-bearing magmatic rocks are calc-alkaline rocks of sub-alkaline series formed during展开更多
1 Introduction The Tudimiaogou-Yindongshan lead-zinc polymetallic orefield is located in the Tudimiaogou-Weimoshi lead and zinc silver polymetallic metallogenic belt.The belt is an important part of southwestern Henan...1 Introduction The Tudimiaogou-Yindongshan lead-zinc polymetallic orefield is located in the Tudimiaogou-Weimoshi lead and zinc silver polymetallic metallogenic belt.The belt is an important part of southwestern Henan lead and zinc展开更多
"Golden triangle"area bordered on Yunnan-Guizhou-Guangxi was one of the most important Carlin-type gold deposits concentration areas.Deep understanding of Carlin-type gold deposits in Guizhou and Guangxi Pro..."Golden triangle"area bordered on Yunnan-Guizhou-Guangxi was one of the most important Carlin-type gold deposits concentration areas.Deep understanding of Carlin-type gold deposits in Guizhou and Guangxi Province had reached through several decades studies,but geological environment was very complex in the southeastern Yunnan,and Carlin-type gold deposits produced in the southeastern Yunnan were different from that of America,few studies were taken there.Based on a large number of field work,studies on the geological characteristics combining with geochemistry characteristics were taken,and analysis the genesis of Laozhaiwan gold deposit.The types of alteration in Laozhaiwan gold deposit were mainly silicification and pyritization,and Gold grade was high when silicification and pyritization were both occurred.It could be caculated that fluid density(g/cm3)varied from 0.7 to 4.9,salinity varied from 0.76%to 0.95%and ore-forming pressure(Pa)varied from 1.81×105 to 49.96×105 according to fluid inclusion test results,showed that Laozhaiwan gold deposit was hypabyssal hydrothermal deposit in low temperature and low salinity.According to composition of fluid inclusion analysis,combining with H-O isotope,made theδD-δ18O figure,showed that the fluid of the deposit rooted in formation water and mixed with meteoric waters later.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
The new results of geologic-structural, petrographic and mineralogic-geochemical researches of Mykert-Sanzheevka ore field—the Uda-Vitim mineragenic zone South-West ending of West Transbaikalia are given. Its main or...The new results of geologic-structural, petrographic and mineralogic-geochemical researches of Mykert-Sanzheevka ore field—the Uda-Vitim mineragenic zone South-West ending of West Transbaikalia are given. Its main ore-controlling structure, represented by losange, consisting of rhombohedral and tetrahedral blocks-duplexes mosaic clusters, which are separated by narrow tectonic sutures, is specified. It is clarified that polycomponent ores clusters are confined with these small-block sutures, made by subvolcanic dykes of shoshonite-latite volcano-plutonic association (233 - 188 million years), apodyke dynamometamorphites (breccias, cataclasite, mylonites) and also mechanometasomatites. Four stages of the dynamometamorphites formation characterized by different species compositions of ore minerals appeared as a result of mechanochemical reactions are determined. A carbonyl model of mineral microaggregates formation with films containing noble metal nanoparticles is proposed. Ore-forming system features of Mykert-Sanzheevka field are considered.展开更多
The Gaoshan gold-silver deposit, located between the Yuyao-Lishui Fault and Jiangshan- Shaoxing fault in Longquan Area, occurs in the Suichang-Longquan gold-silver polymetallic metallogenic belt. This study conducted ...The Gaoshan gold-silver deposit, located between the Yuyao-Lishui Fault and Jiangshan- Shaoxing 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 ore- forming pressure ranges between in 118.02 to 232.13"105 pa, and it is estabmiated that the ore- forming 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 (AgCI), indicates that the ore-forming fluid is rich in F rather than CI. 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 JD and jlSo of fluid inclusions in quartz formed during the main metallogenic stage range from -105%o to -69 %0 and -6.01%o to -3.81%o, 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.展开更多
Through a detailed study of the abundances and spatial-temporal distribution patterns of Te,Bi,As,Se,Cu,Pb,Zn,Au,and Ag in the rock types of different geological epochs in the Dashuigou independent tellurium deposit,a...Through a detailed study of the abundances and spatial-temporal distribution patterns of Te,Bi,As,Se,Cu,Pb,Zn,Au,and Ag in the rock types of different geological epochs in the Dashuigou independent tellurium deposit,and in combination with other research findings of previous researchers in this area,the authors conclude as follows:Abundances of the main ore-forming elements Te,Bi,As,Se,Au,and Ag are not high in the regional geological background,generally lower or close to their respective crustal Clark values,but almost all altered country rocks contain high levels of ore-forming elements.This indicates that the deposit’s ore-forming elements do not come from the country rocks.This also indicates that the geological thermal events that cause alteration and mineralization originate from depths and may be related to mantle plumes.Considering the distribution pattern of these ore-forming elements in the ore bodies’hanging wall and footwall,the metallogenic mechanism may be as follows:Mineralization is not achieved through lateral secretion in the horizontal or near horizontal direction,but rather through the upward movement and emplacement of deep ore-forming elements driven by geological processes such as mantle plumes.In addition,the migration of deep ore-forming elements is not achieved through dispersed infiltration between overlying rock particles,but through non widespread concentrated penetrating channels.This type of channel is likely to be the expansion structures where faults from different directions intersect,or where linear faults intersect with circular structures.展开更多
文摘The compositions of REE in quartz and pyrite from the main stage of the Laowan gold deposit in Henan Province and that in quartz from Laowan granite were determined by inductively coupled plasma-mass-spectrometry (ICP-MS) to trace the source of ore-forming materials. Meanwhile, the REE compositions of the deposit ore, granite and metamorphic wall rock were also considered for comparative studies in detail. The range of ∑REE of quartz and pyrite from the deposit ores is 4.18 × 10^-6- 30.91 × 10^-6, the average of ∑REE is 13.39 × 10^-6, and the average of ∑REE of quartz in the Laowan granite is 6.68 × 10^-6. There is no distinct difference of REE parameters between the deposit ore quartz and granite quartz. The quartz in gold deposit has the same REE particular parameters as quartzes from Laowan granite, such as δEu, δCe, (La/Yb)N and (La/Sm)N, partition degree of LREE to HREE, especially, the chondrite-normalized REE patterns, but no similarity to those from metamorphic wall rock, which shows that ore-forming hydrothermal fluid is mainly the fluid coming from the Laowan granite magma, rather than metamorphic fluid. Meanwhile, comparison studies on REE features between minerals from the deposit ores and related geological bodies in the deposit show that REE characteristics of minerals can serve as an indicator of ore-forming fluid properties and sources, while the REE characteristics of the bulk samples (such as deposit ores, granites and wall rocks) can not trace the source of the ore-forming materials exactly.
文摘The compositions of REE in quartz and pyrite from main mineralized stage of the Laowan gold deposit in Henan province and that of quartz from Laowan granite were determined by Inductively Coupled Plasma-Mass-Spectrometry (ICP-MS). The REE of deposit ore of the Laowan gold deposit, wall-rock and Laowan granite also were studied to trace the source of metallogenic materials in Laowan gold deposit in detail. The range of ∑ REE in quartz and pyrite from gold deposit is 4.18 × 10^-6 - 30.91 × 10^-6, average of 13.39 × 10^-6, 6.68 × 10^-6 of the Laowan granite quartz, obviously lower to REE concentration of deposit, granite and wall-rock. The value of (La/ Yb)N and (La/Sm)N of ore minerals from the gold deposit is 13.23 and 4.17 respectively. The differences in REE parameters, such as δEu, δCe and diffusion degree in REE from light to heavy, among deposit ore minerals and granite mineral are weak. Especially, there are no differences between the chondrite-normalised REE curves of minerals from gold deposit and those of quartzs in Laowan granite, no similarity to wall-rock', which shows that ore-forming hydrothermal fluid mainly came from magma fluid resulting from the Laowan granite magma, metamorphic fluid in few. The results also show that REE characteristics of ore minerals in deposit are effective for disclosing oreforming fluid quality comparing with deposit ore'REE compositions.
文摘Dexing copper deposit is the biggest porphyry copper deposit in China. By researching isotopes of C,Si and Cu from the samples of Tongchang and Fujiawu ore-field, the authors found that δ13CPDB values of siderite were close to the δ13CPDB value of original magma; δ30Si values of the samples at the ore-forming stage were close to the δ30Si value range of magma, δ30Si values of partial samples were far away from it; Cu isotopic compositions of massive chalcopyrite formed at the early ore-forming stage are higher than that of veinal chalcopyrite formed at the later ore-forming stage. The results show that ore-forming materials were mainly derived from the porphyry body, and part of them were from wall rock materials.
基金supported by the NSFC Project(Grant Nos.42162012 and 42072094)the Open Research Project from the Key Laboratory of Sanjiang Metallogeny and Resources Exploration and Utilization,MNR(Grant No.ZRZYBSJSYS2022001)。
文摘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 δ^(34)S 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.
文摘Abstract This paper deals with characteristics of silicon isotope compositions and siliceous cathodoluminescence of host rocks, ores and hydrothermal silicified quartz of the Carlin-type ore deposits in the Yunnan-Guizhou-Guangxi triangle area. The study shows that primary silicified quartz is nonluminescent but quartz in host rocks and secondary silicified quartz are luminescent by the action of cathode rays. Correspondingly, silicon isotope compositions of host rocks, ores and hydro6thermal quartz veins are clearly distinguished. In strata from the Middle Triassic to the “Dachang” host bed, δ30Si of the host rocks ranges from 0.0% ?0.3%, while that of primary ore-forming silicified fluids from ?0.1% to ?0.4%; in the Upper Permian and Lower Carboniferous strata and Indosinian diabase host beds, δ30Si of the host rocks is from ?0.1% to ?0.2% and that of the primary silicified quartz veins from 0.3 % ?0.5 %. This pattern demonstrates the following geochemical mineralization process, primary ore-forming siliceous fluids migrated upwards quickly along the main passages of deep-seated faults from mantle to crust and entered secondary faults where gold deposits were eventually formed as a result of permeation and replacement of the siliceous ore-forming fluids into different ore-bearing strata. This gives important evidence for the fact that ore-forming fluids of this type of gold deposits were mainly derived from upper mantle differentiation and shows good prospects for deep gold deposits and geochemical background for large and superlarge gold deposits.
基金supported by the National Natural Science Foundation of China (No. 41202083, 40373025)the Research Award Fund for Outstanding Middle-aged and Young Scientist of Shandong Province (BS2013HZ024)
文摘The Jinshan gold deposit is located in the Northeast Jiangxi province,South China,which related to the ductile shear zone.It contains two ore types,i.e.the alteration-type ore and the goldbearing quartz vein ore.Rb-Sr age dating is applied to both gold-bearing pyrite in the alteration-type ore and fluid inclusion in the gold-bearing quartz vein to make clear the time of the gold mineralization of the Jinshan deposit.Analytical results of this study yielded that the age of the alteration-type ore bodies is about 838±110Ma,with an initial 87Sr/86Sr value of 0.7045±0.0020.However,the age of the gold-bearing quartz vein-type ore is about 379±49Ma,and the initial 87Sr/86Sr is 0.7138±0.0011.Based on the age data from this work and many previous studies,the authors consider that the Jinshan gold deposit is a product of multi-staged mineralization,which may include the Jinninian,Caledonian,Hercynian,and Yanshanian Periods.Among them,the Jinninian Period and the Hercynian Period might be the two most important ore-forming periods for Jinshan deposit.The Jinninian Period is the main stage for the formation of alteration-type ore bodies,while the Hercynian Period is the major time for ore bodies of gold-bearing quartz vein type.The initial values of the 87Sr/86Sr from this study,as well as the previous isotope and trace element studies,indicate that the ore-forming materials mainly derived from the metamorphic wall rocks,and the ore-forming fluids mainly originated from the deep metamorphic water.
文摘Based on the main characteristics of the tectonic -magmatic evolution of region and Tanlu fault zone,we have discussed ore-bearing magmatic rocks petrochemistry,strontium and lead isotope,and the source of ore-forming materials in Yinan skarn deposit in this paper.The petrochemical features show that the ore-bearing magmatic rocks are calc-alkaline rocks of sub-alkaline series formed during
文摘1 Introduction The Tudimiaogou-Yindongshan lead-zinc polymetallic orefield is located in the Tudimiaogou-Weimoshi lead and zinc silver polymetallic metallogenic belt.The belt is an important part of southwestern Henan lead and zinc
基金financially supported by the Program of National Natural Science Foundation of China(No.41372093No.40930423+2 种基金No.41171302)the work item of China Geological Survey(No.12120113036200)higher education quality engineering project of chalcography excellent textbook Construction(No.XJC1105)
文摘"Golden triangle"area bordered on Yunnan-Guizhou-Guangxi was one of the most important Carlin-type gold deposits concentration areas.Deep understanding of Carlin-type gold deposits in Guizhou and Guangxi Province had reached through several decades studies,but geological environment was very complex in the southeastern Yunnan,and Carlin-type gold deposits produced in the southeastern Yunnan were different from that of America,few studies were taken there.Based on a large number of field work,studies on the geological characteristics combining with geochemistry characteristics were taken,and analysis the genesis of Laozhaiwan gold deposit.The types of alteration in Laozhaiwan gold deposit were mainly silicification and pyritization,and Gold grade was high when silicification and pyritization were both occurred.It could be caculated that fluid density(g/cm3)varied from 0.7 to 4.9,salinity varied from 0.76%to 0.95%and ore-forming pressure(Pa)varied from 1.81×105 to 49.96×105 according to fluid inclusion test results,showed that Laozhaiwan gold deposit was hypabyssal hydrothermal deposit in low temperature and low salinity.According to composition of fluid inclusion analysis,combining with H-O isotope,made theδD-δ18O figure,showed that the fluid of the deposit rooted in formation water and mixed with meteoric waters later.
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.
文摘The new results of geologic-structural, petrographic and mineralogic-geochemical researches of Mykert-Sanzheevka ore field—the Uda-Vitim mineragenic zone South-West ending of West Transbaikalia are given. Its main ore-controlling structure, represented by losange, consisting of rhombohedral and tetrahedral blocks-duplexes mosaic clusters, which are separated by narrow tectonic sutures, is specified. It is clarified that polycomponent ores clusters are confined with these small-block sutures, made by subvolcanic dykes of shoshonite-latite volcano-plutonic association (233 - 188 million years), apodyke dynamometamorphites (breccias, cataclasite, mylonites) and also mechanometasomatites. Four stages of the dynamometamorphites formation characterized by different species compositions of ore minerals appeared as a result of mechanochemical reactions are determined. A carbonyl model of mineral microaggregates formation with films containing noble metal nanoparticles is proposed. Ore-forming system features of Mykert-Sanzheevka field are considered.
基金funded by “Preliminary Study On the Metallogenic Conditions and Prospecting Direction of Gold-Silver Deposits,Suichang-Longquan Area,Zhejiang(No.:YK1401)”“Summary and Research Project of the Mineral Geology of China by Mineral Type(Group)(No.:12120114039601)”+1 种基金“Research Project of the Metallogenic Regularity of the National Important Mineral Areas(No.:1212011121037)”“Comprehensive Research Project of China’s Mineral Geology and Regional Metallogenic Regularity(China’s Mineral Geology)(No.:1212011220369)”
文摘The Gaoshan gold-silver deposit, located between the Yuyao-Lishui Fault and Jiangshan- Shaoxing 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 ore- forming pressure ranges between in 118.02 to 232.13"105 pa, and it is estabmiated that the ore- forming 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 (AgCI), indicates that the ore-forming fluid is rich in F rather than CI. 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 JD and jlSo of fluid inclusions in quartz formed during the main metallogenic stage range from -105%o to -69 %0 and -6.01%o to -3.81%o, 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.
文摘Through a detailed study of the abundances and spatial-temporal distribution patterns of Te,Bi,As,Se,Cu,Pb,Zn,Au,and Ag in the rock types of different geological epochs in the Dashuigou independent tellurium deposit,and in combination with other research findings of previous researchers in this area,the authors conclude as follows:Abundances of the main ore-forming elements Te,Bi,As,Se,Au,and Ag are not high in the regional geological background,generally lower or close to their respective crustal Clark values,but almost all altered country rocks contain high levels of ore-forming elements.This indicates that the deposit’s ore-forming elements do not come from the country rocks.This also indicates that the geological thermal events that cause alteration and mineralization originate from depths and may be related to mantle plumes.Considering the distribution pattern of these ore-forming elements in the ore bodies’hanging wall and footwall,the metallogenic mechanism may be as follows:Mineralization is not achieved through lateral secretion in the horizontal or near horizontal direction,but rather through the upward movement and emplacement of deep ore-forming elements driven by geological processes such as mantle plumes.In addition,the migration of deep ore-forming elements is not achieved through dispersed infiltration between overlying rock particles,but through non widespread concentrated penetrating channels.This type of channel is likely to be the expansion structures where faults from different directions intersect,or where linear faults intersect with circular structures.