Lamprophyres typically appear in hydrothermal gold deposits.The relationship between lamprophyres and gold deposits is investigated widely.Some researchers suggest that the emplacement of lamprophyres triggers gold mi...Lamprophyres typically appear in hydrothermal gold deposits.The relationship between lamprophyres and gold deposits is investigated widely.Some researchers suggest that the emplacement of lamprophyres triggers gold mineralization,whereas others hypothesize that the formation of lamprophyres increases the fertility of mantle sources and ore-forming fluids.K-feldspar veins,with ages between those of lamprophyres and gold deposits,appear in lamprophyres in Zhenyuan.Therefore,K-feldspar veins are ideal for investigating the relationship between lamprophyres and gold deposits.Phlogopite in K-feldspar veins has lower Mg#,Ni,and Cr contents and higher TiO2,Li,Ba,Sr,Sc,Zr,Nb,and Cs contents than phlogopite in lamprophyres.The in-situ Sr isotopic values of apatites(0.7063–0.7066)in K-feldspar veins are within the range for apatites(0.7064–0.7078)from lamprophyres.High large-ion lithophile element concentrations and low Nb and Ta concentrations in phlogopite from lamprophyres,in addition to high(87Sr/86Sr)i values of apatite(0.7064–0.7078),indicate that the magma parental to these phlogopite and apatite crystals is derived from an enriched mantle.Kfeldspar veins are genetically correlated with lamprophyres,whereas sulfide mineral assemblage and trace element compositions of pyrite in K-feldspar veins suggest that K-feldspar veins in lamprophyres are not directly related to gold mineralization of the Zhenyuan deposit.展开更多
By using principal component analysis,this paper had modified and put forward a theoretical model of evaluation on tourist satisfaction degree with tourist perception quality and tourist satisfaction degree as structu...By using principal component analysis,this paper had modified and put forward a theoretical model of evaluation on tourist satisfaction degree with tourist perception quality and tourist satisfaction degree as structure variables and with thirty indexes like image of tourist area,tourists' expectation,infrastructure in tourist area,landscape features and ticket price as observed variables,based on random questionnaire survey of tourists of Zhenyuan ancient city in Guizhou Province and the existing evaluation models of tourist satisfaction degree at home and abroad.The survey result showed that tourist satisfaction degree was not high,that tourists were dissatisfied with observing facilities,transportation,accommodation and landscape features,and that the attraction power of tourist area was weak.The comprehensive tourist satisfaction degree of Zhenyuan ancient city was 77.653.Therefore,the government should enhance reconstruction of infrastructure and construction of landscape features,and improve tourist service quality level,so as to realize sustainable development of tourist economy in Zhenyuan ancient city.展开更多
Orogenic disseminated and Carlin gold deposits share much similarity in alteration and mineralization.The disseminated orogenic Zhenyuan Au deposit along the Ailaoshan shear zone,southeastern Tibet,was selected to cla...Orogenic disseminated and Carlin gold deposits share much similarity in alteration and mineralization.The disseminated orogenic Zhenyuan Au deposit along the Ailaoshan shear zone,southeastern Tibet,was selected to clarify their difference.The alteration and mineralization from the different lithologies,including meta-quartz sandstone,carbonaceous slate,meta-(ultra)mafic rock,quartz porphyry and lamprophyre were researched.According to the mineral assemblage and replacement relationship in all types of host rocks,two reactions show general control on gold deposition:(1) replacement of earlier magnetite by pyrite and carbonaceous material;(2) alteration of biotite and phlogopite phenocrysts in quartz porphyry and lamprophyre into dolomite/ankerite and sericite.Despite the lamprophyre is volumetrically minor and much less fractured than other host rocks,it contains a large portion of Au reserve,indicating that the chemically active lithology has played a more important role in gold precipitation compared to structure.LA-ICP-MS analysis shows that Au mainly occurs as invisible gold in fine-grained pyrite disseminated in the host rocks,with Au content reaching to 258.95 ppm.The diagenetic core of pyrite in meta-quartz sandstone enriched in Co,Ni,Mo,Ag and Hg is wrapped by hydrothermal pyrite enriched in Cu,As,Sb,Au,Tl,Pb and Bi.Different host rock lithology has much impact on the alteration and mineralization features.Carbonate and sericite in altered lamprophyre show they have higher Mg than those developed in other of host rocks denoting that the carbonate and sericite incorporated Mg from phlogopite phenocrysts in the primary lamprophyre during alteration.The ore fluid activated the diagenetic pyrite in meta-quartz sandstone leading the hydrothermal pyrite enriched in Cu,Mo,Ag,Sb,Te,Hg,Tl,Pb and Bi,but the hydrothermal pyrite in meta-(ultra)mafic rock is enriched in Co and Ni as the meta-(ultra)mafic rock host rock contain high content of Co and Ni.However,Au and As shear similar range in both types of host rocks indicating that these two elements most likely come from the deep source fluid rather than the host rocks.It was shown in the disseminated orogenic gold deposit that similar hydrothermal alteration with mineral assemblage of carbonate (mainly dolomite and ankerite),sericite,pyrite and arsenopyrite develops in all types of host rocks.This is different from the Nevada Carlin type,in which alteration is mainly dissolution and silicification of carbonate host rock.On the other hand,Au mainly occur as invisible gold in both disseminated orogenic and Carlin gold deposits.展开更多
The xenoliths in host rocks of hydrothermal gold deposits can generally provide much geochemical information of the deep rocks, which may have an implication for the sources of ore-forming materials. Geochronology and...The xenoliths in host rocks of hydrothermal gold deposits can generally provide much geochemical information of the deep rocks, which may have an implication for the sources of ore-forming materials. Geochronology and geochemical characteristics are reported for a granite xenolith, which is enclosed by the lamprophyre in the Zhenyuan gold deposit(Yunnan Province, SW China). This granite xenolith mainly consists of K-feldspar, quartz, and plagioclase with trace amounts of magnetite, titanite, apatite, zircon, and sulfides. Zircons from the granite xenolith yield a weighted average U-Pb age of 281.1 ± 1.3 Ma(MSWD = 2.1), which could represent the crystallization age of this granite xenolith. The Ti-in-zircon geothermometer and the Mn concentration in apatite calculate that this granite xenolith formed at 685 ± 43℃ with the logf_(O2) values ranging from NNO + 3.7 to NNO + 6.4. The zircons in the granite xenolith have a restricted range of positive ε_(Hf)(t) values ranging from +9.4 to +10.8, and the corresponding Hf TDM2 model ages range from 588 to 678 Ma. The zircon U-Pb age and the Hf isotopic compositions indicate this granite xenolith within the lamprophyre is mainly derived from partial melting of juvenile crustal rocks before the completed closure of the Ailaoshan Ocean. The pyrites in the granite xenolith have higher Bi concentrations, and lower As, Sb, and Tl concentrations than the gold-bearing pyrites of the ores in the Zhenyuan gold deposit. The low Au concentrations of the pyrites together with the ore-forming age of the Zhenyuan gold deposit(Oligocene) indicate the granite xenolith may have limited contribution to the gold mineralization of the Zhenyuan gold deposit.展开更多
Objective: To investigate the effect of sacubitril-valsartan combined with Zhenyuan capsule in the treatment of chronic heart failure comorbid anxiety and depression and its effect on the level of inflammatory factors...Objective: To investigate the effect of sacubitril-valsartan combined with Zhenyuan capsule in the treatment of chronic heart failure comorbid anxiety and depression and its effect on the level of inflammatory factors. Methods: A total of 106 patients with chronic heart failure comorbid anxiety and depression from February 2020 to March 2022 were continuously enrolled and divided into control group (36 cases), observation group A (36 cases) and observation group B (34 cases) according to treatment methods. All groups were given conventional treatment. On the basis of routine treatment, the control group, observation group A and observation group B were given valsartan, sacubitril-valsartan and sacubitril-valsartan plus Zhenyuan Capsules for the treatment of consecutive 8 weeks. The patients in the 3 groups were evaluated by the Self-rating Anxiety Scale (SAS) and Self-rating Depression Scale (SDS) before and after treatment, and the clinical efficacy of heart failure was evaluated, and the detection of left ventricular ejection fraction (LVEF), left ventricular end systolic diameter (LVESD), left ventricular end-diastolic diameter (LVEDD), N terminal brain natriuretic peptide (NT-proBNP), tumor necrosis factor alpha (TNF alpha), interleukin 6 (IL-6), c-reactive protein (CRP) was conducted. Results: The clinical efficacy rate and total effective rate of heart failure in observation group A and observation group B were significantly higher than those in the control group (P < 0.05), and the observation group B was higher than the observation group A (P < 0.05);SAS and SDS scores in observation group A and observation group B were significantly lower than the control group (P < 0.05), and observation group B was lower than observation group A (P < 0.05);The LVEF in the three groups was all increased compared with those before treatment, and the levels of LVESD, LVEDD, NT-proBNP, TNF-α, IL-6, and hs-CRP were all decreased compared with those before treatment;The changes of above indexes in observation group A and observation group B were more significant than those in control group (P < 0.05). Except for the LVEDD index, the observation group B had significant changes compared with the observation group A (P < 0.05). Conclusion: Sacubitril valsartan can improve cardiac function, reduce inflammatory response, and improve anxiety and depression in patients with chronic heart failure, and the treatment effect of combination with Zhenyuan Capsule is more significant.展开更多
This paper determined the fixed-ammonium (NH+-4) contents of lamprophyres in the Zhenyuan gold orefield, Yunnan Province, China. The results show that the NH+-4 contents of minettes in the orefield range from 120×...This paper determined the fixed-ammonium (NH+-4) contents of lamprophyres in the Zhenyuan gold orefield, Yunnan Province, China. The results show that the NH+-4 contents of minettes in the orefield range from 120×10-6 to 469×10-6 and those of kersantites from 74.3×10-6 to 136×10-6. These values are higher than those of other mantle-derived rocks (less than 50×10-6), but lower than those of carbonaceous wall rocks in the orefield (from 1200×10-6 to 1343×10-6). Combining with the Sr isotopic composition, this paper suggested that lamprophyres in the orefield with high NH+-4 contents relative to other mantle-derived rocks would not have resulted from the primary magma contaminated by crustal materials in the process of rising or in the magma chamber, but from mantle metasomatism.展开更多
Emplacement ages of lamproites that comprise lamproite and olivine lamproite in Zhenyuan County, Guizhou Province, China, have been constrained by the whole-rock Sm-Nd and Rb-Sr isochron methods and the whole rock K-A...Emplacement ages of lamproites that comprise lamproite and olivine lamproite in Zhenyuan County, Guizhou Province, China, have been constrained by the whole-rock Sm-Nd and Rb-Sr isochron methods and the whole rock K-Ar method. Intrusive activities of lamproites in the Sinantang area of Zhenyuan County, Guizhou Province, took place during the Late Cambrian, as indicated by the Sm-Nd isochron ages (t) = (503±17) (2σ) Ma and by the Rb-Sr isochron ages (t) = (501.2±4.6) (2σ) Ma. Intrusive activities of olivine lamproites at the Maping with Ⅱ -type diamond and Xitou in Zhenyuan County, Guizhou Province, took place from the Late Cambrian to the Early Ordovician, as evidenced by the Sm-Nd isochron ages (t) = (502±27) (2σ) Ma and by the Rb-Sr isochron age (t) = (502± 27) (2σ) Ma. This suggests that the upwelling hot materials derived from the deep mantle were emplaced from the Late Cambrian to the Early Ordovician (503-497 Ma), while the time terminal of cooling of the geothermal event of展开更多
The Zhenyuan gold orefield is located in the Ailaoshan gold belt, Sanjiang metallogenic region, China. The fluid inclusions (FIs) in mineralized quartz samples, collected from four deposits, i.e., Laowangzhai , Dong...The Zhenyuan gold orefield is located in the Ailaoshan gold belt, Sanjiang metallogenic region, China. The fluid inclusions (FIs) in mineralized quartz samples, collected from four deposits, i.e., Laowangzhai , Donggualin , Kudumu , and Daqiaoqing, in the orefield, were studied to reveal ore-forming process. Only aqueous-type and H20-NaCl-type FIs were observed in the samples. Two generations of FIs are identified due to the spatial occurrences of FIs in host minerals. The early generation is located in the internal zone of quartz crystal, and it has higher homogenization temperatures varying from 180 to 255 ℃ and salinities ranging from 8.7% to 11%; the late generation, often with beating bubbles under room temperature, is developed in the quartz margin, its homogenization temperatures is lower within 95 to 160 ℃. After elimination of the late generation of FIs, early generation FIs compositions were tested. Gaseous phases in the FIs were H20 and CO2, with low contents of N2, CH4, and C2H6, and the liquids mainly contains Na+, K+, Ca^+,Mg^2+, CI, and SO_4^2-. The reappraisal of the previously published hydrogen and oxygen isotope results suggested that the early generation of ore-forming fluid was mainly primary magma hydrothermal, while the late generation fluid contains large amounts of meteoric water. Thus, the result showed that Zhenyuan gold orefield may differ from typical orogenic deposits, which contains abundant CO2-dominated FIs. The two generations FIs developed as quartz grew displaying a continuous evolution of the ore-forming fluids.展开更多
LAMPROPHYRES are one of the rock types which are easily subject to alteration. Alteration can not onlychange their texture and mineral assemblage, but also influence their geochemistry properties. The mostavailable da...LAMPROPHYRES are one of the rock types which are easily subject to alteration. Alteration can not onlychange their texture and mineral assemblage, but also influence their geochemistry properties. The mostavailable data show that alteration will directly influence the content of Au in lamprophyre. For example,in the Superior area of Canada and the Yilgan area of Australia relatively fresh lamprophyres are bothlow in Au contents (3.9×10<sup>-9</sup> and 1.7×10<sup>-9</sup>, respectively), but the contents of Au in altered lamprophyres from both areas are double increased (38×10<sup>-9</sup> and 20×10<sup>-9</sup> on average). Lamprophyres arewidely exposed in the Zhenyuan gold deposit, Yunnan Province and they are closely associated with goldmineralization both in space and in time. So the lamprophyres in the Zhenyuan gold deposit can be citedas the most typical example both at home and abroad. Lamprophyres in the mining district have undergonevarying-degree alteration and partly experienced mineralization. On the basis of the mass equilibrium e-展开更多
基金supported by the National Natural Science Foundation of China(Grant No.41973045)Basic Science and Technology Research Funding of the CAGS(Grant No.JKYZD202312)+1 种基金the National Key Research and Development Project of China(Grant No.2022YFF0800903)National Natural Science Foundation of China(Grant Nos.41802113,42073053,42273073 and 42261144669).
文摘Lamprophyres typically appear in hydrothermal gold deposits.The relationship between lamprophyres and gold deposits is investigated widely.Some researchers suggest that the emplacement of lamprophyres triggers gold mineralization,whereas others hypothesize that the formation of lamprophyres increases the fertility of mantle sources and ore-forming fluids.K-feldspar veins,with ages between those of lamprophyres and gold deposits,appear in lamprophyres in Zhenyuan.Therefore,K-feldspar veins are ideal for investigating the relationship between lamprophyres and gold deposits.Phlogopite in K-feldspar veins has lower Mg#,Ni,and Cr contents and higher TiO2,Li,Ba,Sr,Sc,Zr,Nb,and Cs contents than phlogopite in lamprophyres.The in-situ Sr isotopic values of apatites(0.7063–0.7066)in K-feldspar veins are within the range for apatites(0.7064–0.7078)from lamprophyres.High large-ion lithophile element concentrations and low Nb and Ta concentrations in phlogopite from lamprophyres,in addition to high(87Sr/86Sr)i values of apatite(0.7064–0.7078),indicate that the magma parental to these phlogopite and apatite crystals is derived from an enriched mantle.Kfeldspar veins are genetically correlated with lamprophyres,whereas sulfide mineral assemblage and trace element compositions of pyrite in K-feldspar veins suggest that K-feldspar veins in lamprophyres are not directly related to gold mineralization of the Zhenyuan deposit.
基金Supported by Planning Project of Kaili Institute(Z1009)and Youth Foundation of Special Scientific Research Project of Key Discipline of Tourist Management of Kaili Institute(lgz200904)~~
文摘By using principal component analysis,this paper had modified and put forward a theoretical model of evaluation on tourist satisfaction degree with tourist perception quality and tourist satisfaction degree as structure variables and with thirty indexes like image of tourist area,tourists' expectation,infrastructure in tourist area,landscape features and ticket price as observed variables,based on random questionnaire survey of tourists of Zhenyuan ancient city in Guizhou Province and the existing evaluation models of tourist satisfaction degree at home and abroad.The survey result showed that tourist satisfaction degree was not high,that tourists were dissatisfied with observing facilities,transportation,accommodation and landscape features,and that the attraction power of tourist area was weak.The comprehensive tourist satisfaction degree of Zhenyuan ancient city was 77.653.Therefore,the government should enhance reconstruction of infrastructure and construction of landscape features,and improve tourist service quality level,so as to realize sustainable development of tourist economy in Zhenyuan ancient city.
基金jointly supported by the National Key Research and Development Project of China (Grant No.2016YFC0600307)the National Key Basic Research Development Program (973 Program+1 种基金 Grant No.2015CB452606)the fundamental research funds of university teachers(No.53200959708 and No.2-9-2018-126)
文摘Orogenic disseminated and Carlin gold deposits share much similarity in alteration and mineralization.The disseminated orogenic Zhenyuan Au deposit along the Ailaoshan shear zone,southeastern Tibet,was selected to clarify their difference.The alteration and mineralization from the different lithologies,including meta-quartz sandstone,carbonaceous slate,meta-(ultra)mafic rock,quartz porphyry and lamprophyre were researched.According to the mineral assemblage and replacement relationship in all types of host rocks,two reactions show general control on gold deposition:(1) replacement of earlier magnetite by pyrite and carbonaceous material;(2) alteration of biotite and phlogopite phenocrysts in quartz porphyry and lamprophyre into dolomite/ankerite and sericite.Despite the lamprophyre is volumetrically minor and much less fractured than other host rocks,it contains a large portion of Au reserve,indicating that the chemically active lithology has played a more important role in gold precipitation compared to structure.LA-ICP-MS analysis shows that Au mainly occurs as invisible gold in fine-grained pyrite disseminated in the host rocks,with Au content reaching to 258.95 ppm.The diagenetic core of pyrite in meta-quartz sandstone enriched in Co,Ni,Mo,Ag and Hg is wrapped by hydrothermal pyrite enriched in Cu,As,Sb,Au,Tl,Pb and Bi.Different host rock lithology has much impact on the alteration and mineralization features.Carbonate and sericite in altered lamprophyre show they have higher Mg than those developed in other of host rocks denoting that the carbonate and sericite incorporated Mg from phlogopite phenocrysts in the primary lamprophyre during alteration.The ore fluid activated the diagenetic pyrite in meta-quartz sandstone leading the hydrothermal pyrite enriched in Cu,Mo,Ag,Sb,Te,Hg,Tl,Pb and Bi,but the hydrothermal pyrite in meta-(ultra)mafic rock is enriched in Co and Ni as the meta-(ultra)mafic rock host rock contain high content of Co and Ni.However,Au and As shear similar range in both types of host rocks indicating that these two elements most likely come from the deep source fluid rather than the host rocks.It was shown in the disseminated orogenic gold deposit that similar hydrothermal alteration with mineral assemblage of carbonate (mainly dolomite and ankerite),sericite,pyrite and arsenopyrite develops in all types of host rocks.This is different from the Nevada Carlin type,in which alteration is mainly dissolution and silicification of carbonate host rock.On the other hand,Au mainly occur as invisible gold in both disseminated orogenic and Carlin gold deposits.
基金supported by the National Natural Science Foundation of China (Grant Nos. 91962105, 41802113)the Fundamental Research Funds for the Central Universities (Grant No.2019B08214)a grant from Jiangsu Provincial “Double Innovation Doctors” Program (Grant No.(2020) 30462)。
文摘The xenoliths in host rocks of hydrothermal gold deposits can generally provide much geochemical information of the deep rocks, which may have an implication for the sources of ore-forming materials. Geochronology and geochemical characteristics are reported for a granite xenolith, which is enclosed by the lamprophyre in the Zhenyuan gold deposit(Yunnan Province, SW China). This granite xenolith mainly consists of K-feldspar, quartz, and plagioclase with trace amounts of magnetite, titanite, apatite, zircon, and sulfides. Zircons from the granite xenolith yield a weighted average U-Pb age of 281.1 ± 1.3 Ma(MSWD = 2.1), which could represent the crystallization age of this granite xenolith. The Ti-in-zircon geothermometer and the Mn concentration in apatite calculate that this granite xenolith formed at 685 ± 43℃ with the logf_(O2) values ranging from NNO + 3.7 to NNO + 6.4. The zircons in the granite xenolith have a restricted range of positive ε_(Hf)(t) values ranging from +9.4 to +10.8, and the corresponding Hf TDM2 model ages range from 588 to 678 Ma. The zircon U-Pb age and the Hf isotopic compositions indicate this granite xenolith within the lamprophyre is mainly derived from partial melting of juvenile crustal rocks before the completed closure of the Ailaoshan Ocean. The pyrites in the granite xenolith have higher Bi concentrations, and lower As, Sb, and Tl concentrations than the gold-bearing pyrites of the ores in the Zhenyuan gold deposit. The low Au concentrations of the pyrites together with the ore-forming age of the Zhenyuan gold deposit(Oligocene) indicate the granite xenolith may have limited contribution to the gold mineralization of the Zhenyuan gold deposit.
文摘Objective: To investigate the effect of sacubitril-valsartan combined with Zhenyuan capsule in the treatment of chronic heart failure comorbid anxiety and depression and its effect on the level of inflammatory factors. Methods: A total of 106 patients with chronic heart failure comorbid anxiety and depression from February 2020 to March 2022 were continuously enrolled and divided into control group (36 cases), observation group A (36 cases) and observation group B (34 cases) according to treatment methods. All groups were given conventional treatment. On the basis of routine treatment, the control group, observation group A and observation group B were given valsartan, sacubitril-valsartan and sacubitril-valsartan plus Zhenyuan Capsules for the treatment of consecutive 8 weeks. The patients in the 3 groups were evaluated by the Self-rating Anxiety Scale (SAS) and Self-rating Depression Scale (SDS) before and after treatment, and the clinical efficacy of heart failure was evaluated, and the detection of left ventricular ejection fraction (LVEF), left ventricular end systolic diameter (LVESD), left ventricular end-diastolic diameter (LVEDD), N terminal brain natriuretic peptide (NT-proBNP), tumor necrosis factor alpha (TNF alpha), interleukin 6 (IL-6), c-reactive protein (CRP) was conducted. Results: The clinical efficacy rate and total effective rate of heart failure in observation group A and observation group B were significantly higher than those in the control group (P < 0.05), and the observation group B was higher than the observation group A (P < 0.05);SAS and SDS scores in observation group A and observation group B were significantly lower than the control group (P < 0.05), and observation group B was lower than observation group A (P < 0.05);The LVEF in the three groups was all increased compared with those before treatment, and the levels of LVESD, LVEDD, NT-proBNP, TNF-α, IL-6, and hs-CRP were all decreased compared with those before treatment;The changes of above indexes in observation group A and observation group B were more significant than those in control group (P < 0.05). Except for the LVEDD index, the observation group B had significant changes compared with the observation group A (P < 0.05). Conclusion: Sacubitril valsartan can improve cardiac function, reduce inflammatory response, and improve anxiety and depression in patients with chronic heart failure, and the treatment effect of combination with Zhenyuan Capsule is more significant.
文摘This paper determined the fixed-ammonium (NH+-4) contents of lamprophyres in the Zhenyuan gold orefield, Yunnan Province, China. The results show that the NH+-4 contents of minettes in the orefield range from 120×10-6 to 469×10-6 and those of kersantites from 74.3×10-6 to 136×10-6. These values are higher than those of other mantle-derived rocks (less than 50×10-6), but lower than those of carbonaceous wall rocks in the orefield (from 1200×10-6 to 1343×10-6). Combining with the Sr isotopic composition, this paper suggested that lamprophyres in the orefield with high NH+-4 contents relative to other mantle-derived rocks would not have resulted from the primary magma contaminated by crustal materials in the process of rising or in the magma chamber, but from mantle metasomatism.
基金This work was jointly supported by the National Outstanding Young Scientist Foundation of China (Grant No. 49925309) the State Key Project of Fundamental Research Planning (Grants No. 1999043200) and 95-Y-25.
文摘Emplacement ages of lamproites that comprise lamproite and olivine lamproite in Zhenyuan County, Guizhou Province, China, have been constrained by the whole-rock Sm-Nd and Rb-Sr isochron methods and the whole rock K-Ar method. Intrusive activities of lamproites in the Sinantang area of Zhenyuan County, Guizhou Province, took place during the Late Cambrian, as indicated by the Sm-Nd isochron ages (t) = (503±17) (2σ) Ma and by the Rb-Sr isochron ages (t) = (501.2±4.6) (2σ) Ma. Intrusive activities of olivine lamproites at the Maping with Ⅱ -type diamond and Xitou in Zhenyuan County, Guizhou Province, took place from the Late Cambrian to the Early Ordovician, as evidenced by the Sm-Nd isochron ages (t) = (502±27) (2σ) Ma and by the Rb-Sr isochron age (t) = (502± 27) (2σ) Ma. This suggests that the upwelling hot materials derived from the deep mantle were emplaced from the Late Cambrian to the Early Ordovician (503-497 Ma), while the time terminal of cooling of the geothermal event of
基金supported by the National Key Basic Research Development Program (Nos. 2009CB421006,2009CB421008)the Century Training Program Foundation for the Talents of Humanities and Social Science by the State Education Commission (No. NCET-09-0710)the Program of Introducing Talents of Discipline to Universities of China (No. B07011)
文摘The Zhenyuan gold orefield is located in the Ailaoshan gold belt, Sanjiang metallogenic region, China. The fluid inclusions (FIs) in mineralized quartz samples, collected from four deposits, i.e., Laowangzhai , Donggualin , Kudumu , and Daqiaoqing, in the orefield, were studied to reveal ore-forming process. Only aqueous-type and H20-NaCl-type FIs were observed in the samples. Two generations of FIs are identified due to the spatial occurrences of FIs in host minerals. The early generation is located in the internal zone of quartz crystal, and it has higher homogenization temperatures varying from 180 to 255 ℃ and salinities ranging from 8.7% to 11%; the late generation, often with beating bubbles under room temperature, is developed in the quartz margin, its homogenization temperatures is lower within 95 to 160 ℃. After elimination of the late generation of FIs, early generation FIs compositions were tested. Gaseous phases in the FIs were H20 and CO2, with low contents of N2, CH4, and C2H6, and the liquids mainly contains Na+, K+, Ca^+,Mg^2+, CI, and SO_4^2-. The reappraisal of the previously published hydrogen and oxygen isotope results suggested that the early generation of ore-forming fluid was mainly primary magma hydrothermal, while the late generation fluid contains large amounts of meteoric water. Thus, the result showed that Zhenyuan gold orefield may differ from typical orogenic deposits, which contains abundant CO2-dominated FIs. The two generations FIs developed as quartz grew displaying a continuous evolution of the ore-forming fluids.
文摘LAMPROPHYRES are one of the rock types which are easily subject to alteration. Alteration can not onlychange their texture and mineral assemblage, but also influence their geochemistry properties. The mostavailable data show that alteration will directly influence the content of Au in lamprophyre. For example,in the Superior area of Canada and the Yilgan area of Australia relatively fresh lamprophyres are bothlow in Au contents (3.9×10<sup>-9</sup> and 1.7×10<sup>-9</sup>, respectively), but the contents of Au in altered lamprophyres from both areas are double increased (38×10<sup>-9</sup> and 20×10<sup>-9</sup> on average). Lamprophyres arewidely exposed in the Zhenyuan gold deposit, Yunnan Province and they are closely associated with goldmineralization both in space and in time. So the lamprophyres in the Zhenyuan gold deposit can be citedas the most typical example both at home and abroad. Lamprophyres in the mining district have undergonevarying-degree alteration and partly experienced mineralization. On the basis of the mass equilibrium e-