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Characteristics of Gold Mineralization at the Baguiomo Gold Panning Site, Koudougou Region, Burkina Faso, West Africa
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作者 Pascal Ouiya Aziz Fayçal Tarnagda Martial Eric Fozing 《Open Journal of Geology》 CAS 2024年第1期1-18,共18页
The Birimian Baguiomo formations are located in the northern part of the Boromo greenstone belt. In this belt, the volcanic rocks (tholeiitic basalt, calcalkaline basalt, andesite) hosting the gold mineralization are ... The Birimian Baguiomo formations are located in the northern part of the Boromo greenstone belt. In this belt, the volcanic rocks (tholeiitic basalt, calcalkaline basalt, andesite) hosting the gold mineralization are located in the Kwademen-Baguiomo shear zone. This mineralization, located only a few kilometers from the Kwademen gold deposit, is uncharacterized and, together with the latter, could constitute a gold potential capable of being economically exploitable. It is in this sense that this work is carried out with a view to characterizing the gold mineralization of the Baguiomo gold panning site. To carry out this work, we have made direct field measurements, combined with microstructures, and combined all this with data from geochemical rock analysis of the basalts that are the main host formations. Geochemical data show that tholeitic basalts formed from a mantle plume that was emplaced in an oceanic plateau context. Calc-alkaline basalts and andesites are comparable to Paleoproterozoic tholeitic basalts (PTH3), which are slightly enriched in light rare earths. Fertility tests show that these basalts concentrate between 3 and 6 ppb of gold at the time of accretion, which is sufficient for remobilization of this primary gold during the Eburnian orogeny to yield a deposit of around 4 - 5 Moz. Gold mineralization is associated with pyrite crystals when the latter are disseminated in the rock mass, whereas it is associated with hematite in quartz veins concordant with S1 shear deformation. It is mainly the pyrite crystals in the pressure shadows that contain the gold grains, whose development would be synchronous with micro-shear zone reactivation during the first phase of D1<sub>B</sub> deformation. The second phase of D2<sub>B</sub> deformation, which is a crenulation or fracture schistosity, does not significantly affect the shear deformation that controls mineralization. 展开更多
关键词 Kwademen-Baguiomo Shear Zone gold Panning Site gold mineralization Eburnian Orogeny
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Lithostructural Control of the Gold Mineralization of the Douta Permit of African Star Resources (Kédougou-Kéniéba Inlier, Southeastern Senegal)
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作者 Masse Ndour Papa Moussa Ndiaye +3 位作者 Koffi Félix Ekra Alain Ndong Malick Faye Pierre Ndour 《International Journal of Geosciences》 CAS 2024年第4期303-333,共31页
The Douta permit of African Star Resources/Thor Explorations, located in the southeast of Senegal, in the Kédougou-Kéniéba Inlier (western part of the West African Craton), is dominated to the East by m... The Douta permit of African Star Resources/Thor Explorations, located in the southeast of Senegal, in the Kédougou-Kéniéba Inlier (western part of the West African Craton), is dominated to the East by metasedimentary formations such as greywackes, shales, graphitic shales, quartzites, cherts, claystones and breccias characteristic of the Dialé-Daléma basin. To the West, the mafic formations of the Mako volcanic belt are the most common. Metasedimentary rocks are associated with metavolcanosedimentary terms found at the contact zones between the two (2) Birimian groups. These different geological formations are cut by mafic dolerite and gabbro sills and/or dykes, as well as quartz and microgranite veins. The Douta gold project is crossed from North to South by the MTZ (Main Transcurrent Zone), generally oriented NE-SW and becoming N-S towards the North. The permit is characterized by several shear corridors. The rocks are affected by brittle, brittle-ductile to ductile deformations. The gold mineralization is hosted by a NE-trending shear corridor called the Makosa corridor (Makosa shear zone), therefore sub-parallel to the MTZ. It has a subvertical dip (75˚ to 85˚ to the NW). It is associated with a hydrothermal phase characterized by quartz-sericite-epidote-fine, disseminated pyrite and arsenopyrite ± albite ± chlorite paragenesis. These minerals testify to the existence of a low degree of metamorphism (greenschist facies, epizonal domain) in the area. However, metamorphism reaches amphibolite facies in some places, particularly in the vicinity of intrusive bodies, with the presence of hornblende (amphiboles) and plagioclase. The gold mineralization is mainly hosted by two (2) metasedimentary lithological units: meta-greywackes and shales. 展开更多
关键词 Douta Kédougou-Kéniéba Inlier Senegal Metasedimentary MTZ Control gold mineralization Makosa Corridor
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Gold Mineralisation in the Intiédougou Prospect (Diébougou District) in Southwest Burkina Faso, West African Craton
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作者 Yao Honoré Koffi Wendkouni Passecdé Pauline Zongo +1 位作者 Nanema Mathieu Urbain Wenmenga 《Journal of Minerals and Materials Characterization and Engineering》 2024年第1期63-77,共15页
The Intiédougou located in the Houndé Birimian greenstone belt has been the subject of several mining and geoscience studies that have led to the discovery of mineralized gold targets. One of these mineraliz... The Intiédougou located in the Houndé Birimian greenstone belt has been the subject of several mining and geoscience studies that have led to the discovery of mineralized gold targets. One of these mineralized targets has prompted work that raises the issue of control factors for the gold mineralization of the prospect. The methodology used in this study combines a study of core drill hole data located in the area and laboratory studies. The Intiédougou sector is based on andesito-basaltic, andesitic interstratified volcanoclastite rocks and Tarkwaïen type detrital sedimentary rocks caught in a vice in the volcano-sedimentary unit. Lithostructural analysis of the sector shows that the subvolcanic rocks bearing gold mineralization are subjected to heterogeneous ductile to brittle deformations and affected by hydrothermalism evolving at stages marked by large fissure fillings. These hydrothermal phases evolve in the zones of expansion created by the brittle deformations that have contributed to the deposits of different types of gold-enriched sulphides. These different phases of hydrothermal destabilization generally of low degree accompany the tardi to post-eburnean brittle tectonics. This deformation system is favorable to the establishment of gold mineralization in the form of vein bodies. The overimposition of deformed and altered areas suggests a genetic relationship between deformation and hydrothermal activity. In conclusion, the mineralization of Intiédougou in vein styles, set up in a volcanic arc environment with a paragenesis of gold-pyrite deposit ± chalcopyrite would be controlled by the structural aspect and accompanied by hydrothermal alteration. 展开更多
关键词 Intiédougou Prospect SHEAR HYDROTHERMAL Tarkwaïan gold mineralization
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Geology and Geochemistry of K-feldspar Veins in Lamprophyre at the Zhenyuan Gold Deposit,Yunnan,Southwest China:Implications for Gold Mineralization
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作者 ZHANG Huichao CHAI Peng +2 位作者 ZHANG Hongrui ZHOU Limin HOU Zengqian 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2024年第1期104-116,共13页
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
关键词 LAMPROPHYRE K-feldspar vein apatite Sr isotope gold Zhenyuan deposit YUNNAN
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Gold mineralization in Jiaodong Peninsula and destruction of North China Craton:Insights from Mesozoic granite 被引量:1
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作者 WANG Bin ZHOU Jianbo +8 位作者 DING Zhengjiang ZHAO Tiqun SONG Mingchun BAO Zhongyi LYU Junyang XU Shaohui YAN Chunming LIU Xiangdong LIU Jialiang 《Global Geology》 2023年第2期98-113,共16页
Large-scale tectonic magmatism and extensive gold mineralization have occurred in the eastern North China Craton(NCC)(Jiaodong and Liaodong peninsulas)since Mesozoic,which indicated that the region experienced decrato... Large-scale tectonic magmatism and extensive gold mineralization have occurred in the eastern North China Craton(NCC)(Jiaodong and Liaodong peninsulas)since Mesozoic,which indicated that the region experienced decratonization process.The genesis type of granites evolved from S-type to I-type and A-type during Late Jurassic to Early Cretaceous,and thus reflects the evolution of geodynamics in the Late Mesozoic,indicating the varied subduction process of the Paleo-Pacific Plate(PPP)and the craton destruction.The evolution of geochemical features shows that the mantle beneath the Jiaodong Peninsula evolved from EM-II in Jurassic to EM-I in Early Cretaceous,demonstrating that the mantle switched from enriched to depleted.The gold of decratonic gold deposits in Jiaodong Peninsula mainly comes from the lithospheric mantle domains metasomatized by fluids derived from the metamorphism and dehydration of the subducted slab in the mantle transition zone.The rapid decomposition of minerals leads to the concentrated release of ore-forming fluids,and this process leads to the explosive gold mineralization during the craton destruction.Extensive magmatic uplift and extensional structures,triggered by the craton destruction in Early Cretaceous formed the extensional tectonic system,providing space for the decratonic gold deposits in Jiaodong Peninsula. 展开更多
关键词 Jiaodong Peninsula Mesozoic granite craton destruction decratonic gold deposit extensional structure
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Fe-bearing minerals and implications for gold mineralization for the Wangu deposit in Central Jiangnan Orogen
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作者 Teng Deng Longyue Zhou Zenghua Li 《Acta Geochimica》 EI CAS CSCD 2023年第3期552-571,共20页
Hydrothermal alteration with bleaching of host rocks is the most important prospecting indicator for gold deposits in the Jiangnan Orogen Belt.The alteration has been identified as pre-ore carbonate(siderite)-sericiti... Hydrothermal alteration with bleaching of host rocks is the most important prospecting indicator for gold deposits in the Jiangnan Orogen Belt.The alteration has been identified as pre-ore carbonate(siderite)-sericitization and the Fe of siderite in the alteration zone is derived from the host rocks rather than fluids.In addition,such alteration decreases in intensity and width with depth and gold mineralization also occur in the non-bleached rocks,casting doubt on the reliability of the prospecting indicator.Detailed petrographic work and SEM analysis on the Wangu deposit indicate that there are two types of siderites,i.e.,Sd1 and Sd2.Among them,Sd1 grains are relatively small and distributed along the planes of unaltered host rocks,while Sd2 grains,only occurring in the altered slates,are commonly larger.Both types of siderites were altered by auriferous fluids,producing porous cores and minerals such as pyrite,quartz,and ankerite.Compared with unaltered parts,the altered parts have lower Fe,but higher U,Pb,and REE.In addition,Sd1 and Sd2 are similar in Mn,Na,V,and Sr concentrations but different in Fe and Mg.The occurrence and geochemical compositions of both siderites indicate that Sd1 could be transformed into Sd2 by pre-mineralization alteration through dissolution-reprecipitation.Chlorite is another important Fe-bearing mineral in the host rocks,and EPMA analysis suggests that it is ripidolite with relatively high Fe contents.Consequently,chlorite can also provide Fe to form the pre-ore carbonate(siderite)-sericitization.Geochemical modeling demonstrates that both ripidolite and siderite can result in sulfidation and therefore gold precipitation.As a result,this study demonstrates that pre-ore alteration with characterized bleaching is not a prerequisite for gold mineralization despite of its prominent features.Due to the presence of Fe-bearing Sd1 and chlorite,gold mineralization could still occur through sulfidation in the unaltered rocks. 展开更多
关键词 Jiangnan Orogen gold precipitation Wangu deposit Hydrothermal alteration Fe-bearing minerals
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Correlations between trace elements in pyrite and gold mineralization of gold deposits on the North China platform
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作者 Jianzhao Yin Ying Sun +4 位作者 Haoyu Yin Hongyun Shi James Sparling Yuhong Chao Shoupu Xiang 《Acta Geochimica》 EI CAS CSCD 2023年第6期1079-1103,共25页
By studying both the microscopic physical and chemical typomorphic characteristics of typical mineral pyrite samples associated with representative gold deposits on the north-central margin of the North China Platform... By studying both the microscopic physical and chemical typomorphic characteristics of typical mineral pyrite samples associated with representative gold deposits on the north-central margin of the North China Platform,this paper seeks to identify macroscopic metallogenic mechanisms of gold deposits and to reveal the formation mechanism of lattice gold in pyrite.Typomorphic characteristics of pyrite reveal that pyrite grain size has a negative correlation with gold content.Cubic pyrite,as the dominant crystal form,contains more gold than pentagonal dodecahedral pyrite.Both pyrite crystal forms and chemical compositions indicate that the replacement style of gold deposit formed in a low saturability,low sulfur fugacity,and at temperatures either much higher or much lower than its best forming temperature;comparatively,that of the quartz vein style of gold deposit occurred under conditions with the best temperature,rich in sulfur,and with high sulfur fugacity.The Au/Ag ratios of the pyrites show that both the replacement and quartz vein styles of deposits are mesothermal and hypothermal,while the Co/Ni ratios of the pyrites indicate that the quartz vein style is of magmatic-hydrothermal origin.The X-ray diffraction intensity of pyrite rich in gold is lower than that of pyrite poor in gold at the quartz vein style.In general,with an increase in gold content in pyrite,the total sum intensityΣI decreases.The pyroelectricity coefficient has a negative correlation trend with the values of(Co+Ni+Se+Te)-As and(Co+Ni+Se+Te)/As.The pyrite pyroelectricity of the replacement style is N-type,indicating that it formed under low sulfur fugacity,while that of the quartz vein style is a mixture of P-N types,indicating that it formed under high sulfur fugacity.On the pyroelectricity-temperature diagram,pyrite of the replacement style is mainly distributed between 200 and 270°C,while that of the quartz vein style varies between 90–118 and274–386°C,demonstrating a multistage forming process.In contrast to previous researchers'conclusions,the authors confirm the existence of lattice gold in pyrites through the use of an electron paramagnetic resonance(EPR)test.Au in the form of Au~+,entering pyrite as an isomorph and producing electron–hole centers,makes the centers produce spin resonance absorption and results in EPR absorption peak II.The intensity of auriferous pyrite absorption peak II has certain direct positive correlations with pyrite gold content.The#I and#III absorption peaks of pyrites possibly result from the existence of Ni^(2+)and/or Cu^(2+).γ1,γ2,andγ3 are the strongest and most typical absorption peaks of the infrared spectra of the pyrites.Generally,with the increase in gold content in the pyrite samples,γ1,γ2,andγ3 tend to shift to higher wavenumbers,and the gold content in the pyrite samples has a positive correlation with their relative absorbance. 展开更多
关键词 Unit cell parameter PYROELECTRICITY Electron paramagnetic resonance Infrared spectrum PYRITE gold deposit
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Survival of Seedlings of Native Woody Species in the Rehabilitation of Gold Mined-Site within a Three Years Old Acacia mangium Willd Plantation of St. Elizabeth-Mahdia, Guyana
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作者 Susy Lewis Lawrence Lewis Ryan Dey 《Journal of Environmental Science and Engineering(B)》 2023年第3期133-145,共13页
Active restoration is a critical component of biodiversity conservation for degraded tropical forest ecosystems caused by artisanal gold mining, and the success of restoration is dependent on native species selection.... Active restoration is a critical component of biodiversity conservation for degraded tropical forest ecosystems caused by artisanal gold mining, and the success of restoration is dependent on native species selection. However, significant knowledge gaps exist regarding when and where to plant trees. This article reports on a revegetation trial undertaken in St Elizabeth, Mahdia, Guyana, to assess the survival and RGR (Relative Growth Rate) of three native woody trees and shrubs planted within three years old Acacia mangium Willd trees pruned and unpruned blocks. ANOVA (Analysis of Variance) for a completely randomized block design with four blocks, two pruned and two unpruned, within A. mangium plots. Biochar treatment was added to the plants during transplanting. Thirty-six (36) wildlings of Humiria balsamifera (Aublet.) (Tauroniro), Goupia glabra Aublet (Kabukalli), and Vismia guianensis (Aublet.) Choisy (Bloodwood) were collected and raised in a tree nursery for two weeks. The native plants were transplanted 3 m apart, survival observations and each seedling’s initial height and diameter were measured and recorded. After the experiment, 13% of seedlings from a population of 720 had died, with the highest mortality being experienced at the 92 days of the experiment (t ≤ 122 days). While the overall survival rates were high, emphasizing the importance of field trials on native and exotic species in different environments is essential to fill the knowledge gaps on suitable species for restoration in degraded areas with other land use histories. 展开更多
关键词 Artisanal gold mining native species survival Acacia mangium diameter growth rate.
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Monitoring and analysis of nonlinear dynamic damage of transport roadway supported by composite hard rock materials in Linglong Gold Mine 被引量:9
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作者 MeifengCai XingpingLai 《Journal of University of Science and Technology Beijing》 CSCD 2003年第2期10-15,共6页
The study concentrates mainly on the development of failure process incomposite rock mass. By use of acoustic emission (AE), convergence inspection, pressure monitoring,level measurement techniques and the modem signa... The study concentrates mainly on the development of failure process incomposite rock mass. By use of acoustic emission (AE), convergence inspection, pressure monitoring,level measurement techniques and the modem signal analysis technology, as well as scan electronmicroscopy (SEM) experiment, various aspects of nonlinear dynamic damage of composite rock masssurrounding the transport roadway in Linglong gold mine are discussed. According to the monitoringresults, the stability of the rock mass can be synthetically evaluated, and the intrinsic relationbetween the damage and the characteristic parameters of acoustic emission can be determined. Thelocation of the damage of rock mass can also be detected based on the acoustic emission couplemonitoring signals. Finally, the key factors which influence the stability of the transport roadwaysupported by composite hard rock materials are found out. 展开更多
关键词 monitoring and analysis dynamic damage composite hard rock mass transport roadway Linglong gold mine
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Geochemical and Environmental Evaluation of Um Shashoba Gold Mine Area,Southeastern Desert,Egypt 被引量:2
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作者 Mohamed Abdallah Gad DARWISH 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2011年第4期881-898,共18页
A suite of elements(Ag,Au,Ba,Bi,Cd,Co,Cr,Cu,Ga,Hf,Hg,Mn,Mo,Ni,Pb,Rb,Sb,Se, Sr,Te and Zn),total organic carbon(TOC)and pH were analyzed in stream sediment and tailing samples from Um Shashoba area,in order to evalu... A suite of elements(Ag,Au,Ba,Bi,Cd,Co,Cr,Cu,Ga,Hf,Hg,Mn,Mo,Ni,Pb,Rb,Sb,Se, Sr,Te and Zn),total organic carbon(TOC)and pH were analyzed in stream sediment and tailing samples from Um Shashoba area,in order to evaluate Au placer and the sediments being impacted by old mining activities.Analytical results were examined using statistical,graphical and mapping methods.In spite of the results revealing that Au and most of the elements in sediments were in general significantly lower than those in tailing,Au was concentrated in the NE and SW parts forming Au placer.It is remarkably a close association of Au with Hg and Sb;both are useful as pathfinder elements for Au placers.Values of pH could not control a fate of analyzed elements,whereas TOC and Mn oxides and hydroxides could uptake some elements Au,Ba,Co,Cr,Hg,Ni,and Sr.The results also indicated that the sediments were contaminated by anthropogenic factors causing moderate,strong to very strong pollution with respect to Bi,Se and Te,respectively.Additionally,geogenic factors could also contribute elemental enrichment to the drainage system and cause significant toxicity level. 展开更多
关键词 geochemical exploration environmental evaluation Um Shashoba gold mine EGYPT
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Prediction of Rock Burst with Deep Mining Excavation in Linglong Gold Mine 被引量:3
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作者 Meifeng Cai, Jinan Wang, Shuanghong Wang Civil and Environmental Engineering School, University of Science and Technology Beijing, Beijing 100083. China 《Journal of University of Science and Technology Beijing》 CSCD 2001年第4期241-243,共3页
To predict rock burst in deep mining excavation in Linglong gold mine, systematical laboratory tests of mechanical properties of rock, in situ stress measurement and 3-D FEM analysis on energy distribution in rock mas... To predict rock burst in deep mining excavation in Linglong gold mine, systematical laboratory tests of mechanical properties of rock, in situ stress measurement and 3-D FEM analysis on energy distribution in rock mass surrounding deep mining rooms were carried out. According to various prediction criteria of rock burst, it is concluded that rock burst is liable to occur during deep mining excavation in the mine. 展开更多
关键词 rock burst PREDICTION deep mining excavation Linglong gold mine
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NPV risk simulation of an open pit gold mine project under the O'Hara cost model by using Gas 被引量:1
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作者 Franco-Sepulveda Giovanni Campuzano Carlos Pineda Cindy 《International Journal of Mining Science and Technology》 SCIE EI CSCD 2017年第3期557-565,共9页
This paper analyzes an open pit gold mine project based on the O'Hara cost model. Hypothetical data is proposed based on different authors that have studied open pit gold projects, and variations are proposed acco... This paper analyzes an open pit gold mine project based on the O'Hara cost model. Hypothetical data is proposed based on different authors that have studied open pit gold projects, and variations are proposed according to the probability distributions associated to key variables affecting the NPV, like production level, ore grade, price of ore, and others, so as to see what if, in a gold open pit mine project of 3000 metric tons per day of ore. Two case scenarios were analyzed to simulate the NPV, one where there is low certainty data available, and the other where the information available is of high certainty. Results based on genetic algorithm metaheuristic simulations, which combine basically Montecarlo simulations provided by the Palisade Risk software, the O'Hara cost model, net smelter return and financial analysis tools offered by Excel are reported, in order to determine to which variables of the project is more sensitive the NPV. 展开更多
关键词 Genetic algorithms(GAs) O’Hara cost model Montecarlo simulation Open pit gold mine NPV risk analysis
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Characterization of Galena and Vein Paragenesis in the Penjom Gold Mine,Malaysia:Trace Elements,Lead Isotope Study and Relationship to Gold Mineralization Episodes 被引量:1
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作者 Zakaria ENDUT NG Tham Fatt +2 位作者 Jasmi Hafiz ABDUL AZIZ Sebastien MEFFRE Charles MAKOUNDI 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2015年第6期1914-1925,共12页
The Penjom Gold Mine is located 30 km from the Bentong-Raub Suture at the western boundary of the Central Belt in Peninsular Malaysia. Gold mineralization hosted within the vein system is associated with pyrite, arsen... The Penjom Gold Mine is located 30 km from the Bentong-Raub Suture at the western boundary of the Central Belt in Peninsular Malaysia. Gold mineralization hosted within the vein system is associated with pyrite, arsenopyrite, and minor base metals including galena. Trace element and lead isotope analysis was undertaken on nine samples that represent two stages of galena formed during two tectonic events. Both the Pb isotopes and the trace elements show that the first stage galena within the mineralized areas at the footwall has different geochemical characteristics compared with galena in non mineralized areas in the hanging wall, suggesting that galena crystallized from two different ore fluids and probably at two different times. Higher Te, Se and Bi in the galena from the mineralized area may indicate hydrothermal fluids that migrate through the structural conduit and leached out the metal along the pathway that consist of dominant carbonaceous unit. The Pb isotopic ratio composition are transitional between the bulk crustal growth and an upper crustal growth curve, indicating that derivation was from arc rocks associated with continental crust or a crustal source that includes arc volcanic and old continental sedimentary rocks. 展开更多
关键词 Vein paragenesis GALENA trace elements lead isotope and gold mineralization
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Chemical and physical characteristics of quartz from gold deposits in the North China platform: relationship to gold mineralization 被引量:1
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作者 Jianzhao Yin Yang Liu Hongyun Shi 《Acta Geochimica》 EI CAS CSCD 2021年第6期998-1022,共25页
This paper seeks to identify macroscopic metallogenic mechanisms of various mineral deposits by studying microscopic typomorphic characteristics of typical minerals associated with the deposits and to reveal the mecha... This paper seeks to identify macroscopic metallogenic mechanisms of various mineral deposits by studying microscopic typomorphic characteristics of typical minerals associated with the deposits and to reveal the mechanism of lattice gold in detail by studying both physical and chemical characteristics of quartz from representative gold deposits in the North China Platform.As part of their extensive research,the authors examine the relationship between trace elements with wall rock,the ore-forming media,and gold immigration of various types of gold deposits,including their salinity,type,temperature.These are key factors to revealing the mineralization mechanism,and indicators for mineral prospecting,exploration,mining,and metallurgical technology.In order to address the questions posed,the following methods were used:field investigations of geology and sampling of the representative gold deposits,physical study and chemical analysis of quartz including,but not limited to,fluid inclusions as well as their compositions and trace elements in quartz,the unit cell parameters,electron paramagnetic resonance spectrum(EPR),and infrared spectroscopic analysis(ISA).As a result of this study,the authors observe the following key findings:unit cell parameters of quartz vary with their contents of foreign elements including gold,paragenetic stage,wall rock type,and other factors;the higher the forming temperature and the lower the gold content in quartz,the smaller the unit cell parameters,and vice versa.Additionally,the EPR absorption lines resulted from the O–Al defect center.The density of these types of hole centers increases and the EPR signal strengthens when the temperature decreases.Based on the findings,the authors conclude that lattice gold exists in quartz.Gold,in the form of Au^(+)and/or Au^(3+),entering quartz and producing an electron–hole center,namely,the O-Au hole center,makes the center produce spin resonance absorption and results in the EPR absorption peak#I.Both unit cell parameters and EPR of quartz can potentially be used in mineral prospecting,relative ore-forming temperature determination,and grade control during mining. 展开更多
关键词 Physical and chemical characteristics QUARTZ gold mineralization Unit cell parameter Electron paramagnetic resonance spectrum Infrared spectrum
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The potential of arbuscular mycorrhizal fungi to conserve Kalappia celebica,an endangered endemic legume on gold mine tailings in Sulawesi,Indonesia
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作者 Husna Faisal Danu Tuheteru Asrianti Arif 《Journal of Forestry Research》 SCIE CAS CSCD 2021年第2期675-682,共8页
Kalapi(Kalappia celebica)is an endemic legume of Sulawesi and has been included in the endangered category since the early 1980s.Conservation of the species is possible through ex situ culture techniques.Arbuscular my... Kalapi(Kalappia celebica)is an endemic legume of Sulawesi and has been included in the endangered category since the early 1980s.Conservation of the species is possible through ex situ culture techniques.Arbuscular mycorrhizal fungi(AMF)can accelerate plant growth which in turn supports the conservation of endangered species.This study aimed to assess the efficacy of local AMF to accelerate the growth of kalapi and increase nutrient uptake in kalapi grown in gold mine tailing media.There were three AMF treatments,Glomus claroideum,Glomus coronatum,and a mixture of both,plus the control.Each treatment was replicated three times,each consisting of five plants.The results show that the highest AMF colony was obtained by kalapi seedlings inoculated with Glomus coronatum and the mixture of AMF.The range of mycorrhizae inoculation effect values was 59.7–71.3%.AMF inoculation increased growth and dry weight of 4-month-old seedlings compared to controls.Dry and total weights of kalapi inoculated with G.coronatum were significantly different from those inoculated with the AMF mixture.However,they are not significantly different from kalapi inoculated with G.claroideum.The results also show that AMF increased nitrogen and phosphorous uptake by the roots,as well as nitrogen,phosphorous,potassium,manganese and iron by the shoots.All AMF treatments decreased potassium uptake in the roots,except in kalapi inoculated with G.coronatum.The AMF mixture decreased iron contents the roots by 15%.AMF can be developed into biofertilizer to support the conservation of kalapi in tropical Indonesia. 展开更多
关键词 Kalappia celebica GLOMEROMYCOTA Glomus coronatum gold mine tailings Southeast Sulawesi
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Alteration Information Extraction by Applying Synthesis Processing Techniques to Landsat ETM+Data: Case Study of Zhaoyuan Gold Mines, Shandong Province, China
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作者 刘福江 吴信才 +1 位作者 孙华山 郭艳 《Journal of China University of Geosciences》 SCIE CSCD 2007年第1期72-76,共5页
Satellite remote sensing data are usually used to analyze the spatial distribution pattern of geological structures and generally serve as a significant means for the identification of alteration zones. Based on the L... Satellite remote sensing data are usually used to analyze the spatial distribution pattern of geological structures and generally serve as a significant means for the identification of alteration zones. Based on the Landsat Enhanced Thematic Mapper (ETM+) data, which have better spectral resolution (8 bands) and spatial resolution (15 m in PAN band), the synthesis processing techniques were presented to fulfill alteration information extraction: data preparation, vegetation indices and band ratios, and expert classifier-based classification. These techniques have been implemented in the MapGIS-RSP software (version 1.0), developed by the Wuhan Zondy Cyber Technology Co., Ltd, China. In the study area application of extracting alteration information in the Zhaoyuan (招远) gold mines, Shandong (山东) Province, China, several hydorthermally altered zones (included two new sites) were found after satellite imagery interpretation coupled with field surveys. It is concluded that these synthesis processing techniques are useful approaches and are applicable to a wide range of gold-mineralized alteration information extraction. 展开更多
关键词 alteration information extraction Zhaoyuan gold mines Landsat-7 ETM+ data
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The Rock Gold Mine in Tibet
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《Rare Metals》 SCIE EI CAS CSCD 1992年第1期74-74,共1页
The Dongga Gold Mine had been discovered in Tibet Autonomous Region. Themineralization area amounts to 5 km~2. The gold analysis on-the-spot indicates that perspective re-serve is expected to large-scale. This is the ... The Dongga Gold Mine had been discovered in Tibet Autonomous Region. Themineralization area amounts to 5 km~2. The gold analysis on-the-spot indicates that perspective re-serve is expected to large-scale. This is the first fruit of mineral expedition in Tibet, and is of greatsignificance for future nonferrous metal industry in Tibet. 展开更多
关键词 gold The Rock gold mine in Tibet
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Jiaodong Granitoids and Gold Mineralization
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作者 Chen Guangyuan Sun Daisheng Shao Yue(Department of Geology and Mineral Resources, China University of Geosciences, Beijing 100083) 《Journal of Earth Science》 SCIE CAS CSCD 1995年第1期71-78,共8页
Gold Production in Jiaodong started in 598 AD, reached 89.5% of the country's total output in 1078 AD ac is now still on the topmost in China. The Jiaodong Group forming the Neoarchaean crystalline basement belong... Gold Production in Jiaodong started in 598 AD, reached 89.5% of the country's total output in 1078 AD ac is now still on the topmost in China. The Jiaodong Group forming the Neoarchaean crystalline basement belongs to the magnetite tyep consisting in the main of gold-bearing basic to intermediate-acidic matavolcanics. The Mesozoic granitoids generated from partial remelting of the Jiaodong Group consequently belong also to the I-type and magnetite series by showing strong petrochemical, mineralogical and crystallochemical inheritance to the Jiaodong Group .There are three major types of granitoids hosting gold deposits in Jiaodong, namely the Lingong monzonitic grenite (J2 ), the Guojialing granodiorite (J3 )and the Kunyushan monzonitic granite (K1). the isotopic chronological data indicate that there are also three stages of gold mineralization (K1 )corresponding to the formation of the three major types of gramitoids, but the former is not the direct Product of magmatic differentiation from the latter .The Mesozic tectonism and dynamometamorphism on mobile margin of continental Plate Played an important role in both deliverance of gold from source rocks into hydrothermal solution and later deposition from the hydrothermal solution to form gold deposits. Mineraloglcal criteria of redox conditions of granitoids, mineraloglcal, petrochemical and crystallochemical data favorable for gold mineralization in general, and especially in Jiaodong granitoids, are summarized. Difference in gold mineralization in the three major types of Jiaodong grauitoids is also roughly given. 展开更多
关键词 GRANITOIDS gold mineralization Jiaodong.
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New Zircon U-Pb Age of the Badu Dolerite:Implications for Yanshanian Magmatic Gold Mineralization within the Youjiang Basin, Southwest China
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作者 WU Songyang HOU Lin +3 位作者 DING Jun LIU Shusheng ZHANG Qiming ZHAO Zhenyu 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2018年第3期1272-1273,共2页
Objective The Youjiang basin,also named"Dian-Qian-Gui Golden Triangle",contains a cluster of Carlin-like gold deposits(Deng and Wang,2016).Due to the uncertainty of mineralization age and the absence of coet... Objective The Youjiang basin,also named"Dian-Qian-Gui Golden Triangle",contains a cluster of Carlin-like gold deposits(Deng and Wang,2016).Due to the uncertainty of mineralization age and the absence of coetaneous magmatic rocks(Chen et al.,2015),the relationship between magmatism and Au mineralization still remains controversial in recent years(Hou et al.,2016).The Late 展开更多
关键词 New Zircon U-Pb Age gold mineralization
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Microchemical Characterization of Natural Gold and Copper Alloys from the Ancient Um Shashoba Gold Mine, South Egypt
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作者 Mohamed Abdallah Gad DARWISH 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2014年第1期196-212,共17页
The SEM-EDX technique was applied to investigate Au, and Cu+Sn alloyed grains in the mineralization of the Um Shashoba mine for achieving further understanding of occurrences, internal structures and microchemistry o... The SEM-EDX technique was applied to investigate Au, and Cu+Sn alloyed grains in the mineralization of the Um Shashoba mine for achieving further understanding of occurrences, internal structures and microchemistry of Au and Cu alloys and associated minerals, and mineralization type. This study is aiming at the genetic history of ore-bearing fluid events, geochemical evaluation and exploration significance. The results showed that the mineralization could be considered as a single major episode generated by metamorphic mesothermal solution rich in sulfides and unsaturated respect to Au. It was differentiated into many stages; started with formation of auriferous pyrite that was pseudomorphed by secondary hematite, limonite and goethite. Three phases of Au alloy were precipitated, and Cu+Sn and Ag-rich alloys were produced respectively and followed by deposition of two generations of barren pyrite. Calcite and ankerite were crystalized, surrounded and partially replaced some of early formed minerals. Finally, barren muscovite recrystallized around and inside both later formed carbonate minerals that were free of any sign of Au in their structures. The processes of deformation, recrystallization, annealing, dissolution, remobilization and re-precipitation played the most important roles in the genetic history of the mineralization. 展开更多
关键词 SEM–EDX analyses Au and Cu alloy grains Um Shashoba gold mine Egypt
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