Pub Date : 2023-11-09DOI: 10.1080/25726838.2023.2265248
Jeff B. Chaumba, Antony Mamuse
ABSTRACTThe Zvishavane Ultramafic Complex (ZUC) is a metamorphosed ultramafic-mafic body exposed within the Zvishavane gneiss complex in south central Zimbabwe. The complex hosts Africa's largest mine and reserves of high-grade chrysotile asbestos. Rock types of the ZUC range from serpentinites, metadunites, and metagabbros. Accessory chromites, which are altered to ferrian chromites, are hosted in metadunites and serpentinites. Chromium number, Cr# (100*Cr/(Cr + Al)), is extremely high, and ranges from 90.6 to 99.5. Low magnesium number, Mg# 100*Mg/(Mg + Fe2+), ranges from 5.1 to 8.4.Most ZUC ferrian chromites occur as inclusions or marking the outlines of relict olivine crystals, and in veinlets traversing the serpentinites. On 100*Fe3+/(Al + Fe3+) versus 100*Fe2+/(Mg + Fe2+) diagram, the chromites all plot in the magnesioferrite field, and in the ferrian chromite field on a Fe3+-Cr-Al ternary diagram. On wt% Al2O3 versus wt% Cr2O3 and 100*Cr/(Cr + Al) versus 100*Mg/(Mg + Fe2+) plots, chromites all plot in the modified trend fields. The bulk of the chromites were metamorphosed at temperatures of ≤500°C, and no samples experienced temperatures exceeding 550°C. A plot of Fe3+/(Fe3++ Fe2+) versus wt% MnO is indicative of hydrous metamorphism of ZUC chromites. It is interpreted that extensive modification of the ZUC chromites occurred during hydrothermal alteration, under conditions more oxidising than quartz-fayalite-magnetite but less than magnetite-hematite, which accompanied the formation of high-grade chrysotile asbestos for which the ZUC is famous. Four granitic plutons exposed within 50km of ZUC were likely the source of hydrothermal fluids responsible for extensive hydrothermal alteration, which likely led to the formation of high-grade chrysotile asbestos, and almost completely modifying the chromites in the process. Compositions of accessory chromites in chrysotile asbestos meta-ultramafic bodies elsewhere are likely to be extremely modified.KEYWORDS: Zimbabwe cratonchromite chemistrychromite modificationchrysotile asbestosultramafic complexArcheanferrian chromitepetrography AcknowledgementsMidlands State University funded sampling and couriering costs. We are grateful to the field assistants who offered invaluable help during fieldwork. The University of North Carolina at Pembroke funded analytical costs and the costs of thin sections. Suggestions and comments from anonymous reviewers helped improve our manuscript. Journal Editor Adam Simon is thanked for his comments and for handling of the article.Disclosure statementNo potential conflict of interest was reported by the author(s).Additional informationFundingThis work was supported by University of North Carolina at Pembroke.
{"title":"Geochemistry of extremely modified chromites from the chrysotile asbestos-bearing Zvishavane Ultramafic Complex, south central Zimbabwe","authors":"Jeff B. Chaumba, Antony Mamuse","doi":"10.1080/25726838.2023.2265248","DOIUrl":"https://doi.org/10.1080/25726838.2023.2265248","url":null,"abstract":"ABSTRACTThe Zvishavane Ultramafic Complex (ZUC) is a metamorphosed ultramafic-mafic body exposed within the Zvishavane gneiss complex in south central Zimbabwe. The complex hosts Africa's largest mine and reserves of high-grade chrysotile asbestos. Rock types of the ZUC range from serpentinites, metadunites, and metagabbros. Accessory chromites, which are altered to ferrian chromites, are hosted in metadunites and serpentinites. Chromium number, Cr# (100*Cr/(Cr + Al)), is extremely high, and ranges from 90.6 to 99.5. Low magnesium number, Mg# 100*Mg/(Mg + Fe2+), ranges from 5.1 to 8.4.Most ZUC ferrian chromites occur as inclusions or marking the outlines of relict olivine crystals, and in veinlets traversing the serpentinites. On 100*Fe3+/(Al + Fe3+) versus 100*Fe2+/(Mg + Fe2+) diagram, the chromites all plot in the magnesioferrite field, and in the ferrian chromite field on a Fe3+-Cr-Al ternary diagram. On wt% Al2O3 versus wt% Cr2O3 and 100*Cr/(Cr + Al) versus 100*Mg/(Mg + Fe2+) plots, chromites all plot in the modified trend fields. The bulk of the chromites were metamorphosed at temperatures of ≤500°C, and no samples experienced temperatures exceeding 550°C. A plot of Fe3+/(Fe3++ Fe2+) versus wt% MnO is indicative of hydrous metamorphism of ZUC chromites. It is interpreted that extensive modification of the ZUC chromites occurred during hydrothermal alteration, under conditions more oxidising than quartz-fayalite-magnetite but less than magnetite-hematite, which accompanied the formation of high-grade chrysotile asbestos for which the ZUC is famous. Four granitic plutons exposed within 50km of ZUC were likely the source of hydrothermal fluids responsible for extensive hydrothermal alteration, which likely led to the formation of high-grade chrysotile asbestos, and almost completely modifying the chromites in the process. Compositions of accessory chromites in chrysotile asbestos meta-ultramafic bodies elsewhere are likely to be extremely modified.KEYWORDS: Zimbabwe cratonchromite chemistrychromite modificationchrysotile asbestosultramafic complexArcheanferrian chromitepetrography AcknowledgementsMidlands State University funded sampling and couriering costs. We are grateful to the field assistants who offered invaluable help during fieldwork. The University of North Carolina at Pembroke funded analytical costs and the costs of thin sections. Suggestions and comments from anonymous reviewers helped improve our manuscript. Journal Editor Adam Simon is thanked for his comments and for handling of the article.Disclosure statementNo potential conflict of interest was reported by the author(s).Additional informationFundingThis work was supported by University of North Carolina at Pembroke.","PeriodicalId":43298,"journal":{"name":"Applied Earth Science-Transactions of the Institutions of Mining and Metallurgy","volume":" 40","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135290909","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-10-19DOI: 10.1080/25726838.2023.2259737
Dickson E. Ngowi, Elisante E. Mshiu, Michael Msabi
ABSTRACTThis study used the weight of evidence model to delineate prospective areas for gold deposits in the Lupa Goldfield. The method establishes a spatial relationship between known mineral deposits and evidential maps to create a mineral prospectivity map. Four evidential maps derived from geochemical, geological, geophysical, and topographical Digital Elevation Model (DEM) datasets were analysed and integrated to create a mineral prospectivity map. Results have revealed five classes ranked from the highest, high, medium, low, and lowest favourability patterns with probability values of 0.051, 0.0426, 0.0225, 0.0172, and 0.0091, respectively. The highest favourable areas have the best gold potentials based on the presence of predictor patterns from all four evidential maps. The posterior probability map revealed good prediction, existing gold deposits, such as Saza Mine and Shanta Gold Mine, were mapped. Results have shown that the weight of evidence model was successful and can be applied in mineral exploration targeting.KEYWORDS: Mineral prospectivity mapping; weight of evidence model; geographical information system (GIS); Lupa Goldfieldmineral exploration AcknowledgementThe authors would like to thank the Geological Survey of Tanzania for providing geological, geochemical, and geophysical data which were used in this study.Disclosure statementNo potential conflict of interest was reported by the author(s).Additional informationFundingThis work was supported by Ministry of Minerals, Tanzania.
{"title":"Mineral prospectivity modelling to delineate potential areas for gold deposits: a case study of Lupa Goldfield, South West Tanzania","authors":"Dickson E. Ngowi, Elisante E. Mshiu, Michael Msabi","doi":"10.1080/25726838.2023.2259737","DOIUrl":"https://doi.org/10.1080/25726838.2023.2259737","url":null,"abstract":"ABSTRACTThis study used the weight of evidence model to delineate prospective areas for gold deposits in the Lupa Goldfield. The method establishes a spatial relationship between known mineral deposits and evidential maps to create a mineral prospectivity map. Four evidential maps derived from geochemical, geological, geophysical, and topographical Digital Elevation Model (DEM) datasets were analysed and integrated to create a mineral prospectivity map. Results have revealed five classes ranked from the highest, high, medium, low, and lowest favourability patterns with probability values of 0.051, 0.0426, 0.0225, 0.0172, and 0.0091, respectively. The highest favourable areas have the best gold potentials based on the presence of predictor patterns from all four evidential maps. The posterior probability map revealed good prediction, existing gold deposits, such as Saza Mine and Shanta Gold Mine, were mapped. Results have shown that the weight of evidence model was successful and can be applied in mineral exploration targeting.KEYWORDS: Mineral prospectivity mapping; weight of evidence model; geographical information system (GIS); Lupa Goldfieldmineral exploration AcknowledgementThe authors would like to thank the Geological Survey of Tanzania for providing geological, geochemical, and geophysical data which were used in this study.Disclosure statementNo potential conflict of interest was reported by the author(s).Additional informationFundingThis work was supported by Ministry of Minerals, Tanzania.","PeriodicalId":43298,"journal":{"name":"Applied Earth Science-Transactions of the Institutions of Mining and Metallurgy","volume":"220 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135666908","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-10-09DOI: 10.1080/25726838.2023.2265242
T. P. Pinheiro, C. A. Almeida, L. M. Pinheiro, D. M. Valeriano, A. R. Gomes, M. Adami, A. Scheide, S. H. Nogueira
ABSTRACTLess than half of the original two million km2 of the Brazilian Savanna natural vegetation, called the Cerrado Biome, remains standing. Given its climate and socio-biodiversity importance, more effective public policies are needed to protect the remaining natural areas. In this paper, we present the methodology and results of the DETER Cerrado, an early warning deforestation system within the Cerrado region. The findings support that DETER is effective in detecting a wider range of deforestation patch sizes, from the larger patches, heavily associated with agricultural expansion, to the smaller areas (>1 ha <10 ha). Nevertheless, 80% of the deforestation is concentrated in the 10-km radius zone from the DETER Alerts. This area was later detected by the Cerrado Deforestation Monitoring Project (PRODES), the system that accounts for the annual deforestation rate assessment, which highlights the capability of the DETER system to provide support to the surveillance of deforestation in the Cerrado.KEYWORDS: Land cover changemonitoringdesign methodologyforest governanceBrazilian savanna woodland Disclosure statementNo potential conflict of interest was reported by the author(s).Geolocation informationBounding Box - X: -41.512, Y: -2.699; X: -61.071, Y: -23.793.Data availability statementThe data that support the findings of this study are openly available in the TerraBrasilis platform at http://terrabrasilis.dpi.inpe.br/en/download-2/, reference number e6e15388-4ca9-49b9-aec9-03891339a35e.Additional informationFundingThis work was supported by the World Bank Group under Grant P143185; and the Conselho Nacional de Desenvolvimento Científico e Tecnológico under Grant 444418/2018-0, 306334/2020-8, 381125/2023-8, 381120/2023-6. We thank Laboratório de Processamento de Imagens (LAPIG/UFG) for assistance in the field, the anonymous reviewers, and Prof. Dr. Camilo Rennó for suggestions in the manuscript.
【摘要】被称为塞拉多生物群(Cerrado Biome)的巴西热带稀树草原原200万平方公里的自然植被中，只有不到一半的植被仍然存在。鉴于其气候和社会生物多样性的重要性，需要更有效的公共政策来保护剩余的自然区域。本文介绍了Cerrado地区森林砍伐预警系统DETER Cerrado的方法和结果。研究结果表明，DETER在检测更大范围的森林砍伐斑块大小方面是有效的，从与农业扩张密切相关的较大斑块到较小的区域(>1公顷<10公顷)。然而，80%的森林砍伐集中在震慑警报半径10公里的区域。塞拉多森林砍伐监测项目(PRODES)后来发现了这一地区，该系统负责每年的森林砍伐率评估，突出了DETER系统为塞拉多森林砍伐监测提供支持的能力。关键词:土地覆盖变化监测设计方法森林治理巴西稀树草原林地披露声明作者未报告潜在的利益冲突。地理位置信息边界框- X: -41.512, Y: -2.699;X: -61.071, y: -23.793。数据可用性声明支持本研究结果的数据可在TerraBrasilis平台上公开获取，网址为http://terrabrasilis.dpi.inpe.br/en/download-2/，参考编号为e6e15388-4ca9-49b9-aec9-03891339a35e。本工作得到了世界银行集团P143185赠款的支持;和国家环境保护研究中心Científico e Tecnológico，资助444418/2018- 0,306334 /2020- 8,381125 /2023- 8,381120 /2023-6。我们感谢Laboratório de Processamento de Imagens (LAPIG/UFG)在现场提供的帮助，匿名审稿人，以及Camilo博士教授Rennó在手稿中的建议。
{"title":"The near real-time deforestation detection system: case study of the DETER system for the Cerrado Biome","authors":"T. P. Pinheiro, C. A. Almeida, L. M. Pinheiro, D. M. Valeriano, A. R. Gomes, M. Adami, A. Scheide, S. H. Nogueira","doi":"10.1080/25726838.2023.2265242","DOIUrl":"https://doi.org/10.1080/25726838.2023.2265242","url":null,"abstract":"ABSTRACTLess than half of the original two million km2 of the Brazilian Savanna natural vegetation, called the Cerrado Biome, remains standing. Given its climate and socio-biodiversity importance, more effective public policies are needed to protect the remaining natural areas. In this paper, we present the methodology and results of the DETER Cerrado, an early warning deforestation system within the Cerrado region. The findings support that DETER is effective in detecting a wider range of deforestation patch sizes, from the larger patches, heavily associated with agricultural expansion, to the smaller areas (>1 ha <10 ha). Nevertheless, 80% of the deforestation is concentrated in the 10-km radius zone from the DETER Alerts. This area was later detected by the Cerrado Deforestation Monitoring Project (PRODES), the system that accounts for the annual deforestation rate assessment, which highlights the capability of the DETER system to provide support to the surveillance of deforestation in the Cerrado.KEYWORDS: Land cover changemonitoringdesign methodologyforest governanceBrazilian savanna woodland Disclosure statementNo potential conflict of interest was reported by the author(s).Geolocation informationBounding Box - X: -41.512, Y: -2.699; X: -61.071, Y: -23.793.Data availability statementThe data that support the findings of this study are openly available in the TerraBrasilis platform at http://terrabrasilis.dpi.inpe.br/en/download-2/, reference number e6e15388-4ca9-49b9-aec9-03891339a35e.Additional informationFundingThis work was supported by the World Bank Group under Grant P143185; and the Conselho Nacional de Desenvolvimento Científico e Tecnológico under Grant 444418/2018-0, 306334/2020-8, 381125/2023-8, 381120/2023-6. We thank Laboratório de Processamento de Imagens (LAPIG/UFG) for assistance in the field, the anonymous reviewers, and Prof. Dr. Camilo Rennó for suggestions in the manuscript.","PeriodicalId":43298,"journal":{"name":"Applied Earth Science-Transactions of the Institutions of Mining and Metallurgy","volume":"294 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135146309","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-09-29DOI: 10.1080/25726838.2023.2260583
Fuseini Atanga, Prince Ofori Amponsah, Samuel Nunoo, Daniel Kwayisi, Eric Dominic Forson, Thomas Mba Akabzaa, Prosper Mckenzie Nude
ABSTRACTThis paper focuses on the geology and geochemistry of the Rhyacian Josephine gold deposit in northwestern Ghana, where gold is primarily hosted in quartzites, with other lithologies observed, including granitoids, mafic intrusions, and gneisses. Four deformational events, DJO0, DJO1, DJO2, and DJO3, are observed. DJO0 is synonymous with the primary preserved sedimentary crossbedding in the quarzitic rocks. Gold mineralization within the deposit is mainly associated with the DJO1 NNW-trending dextral and steeply dipping sinusoidal shear zone. Gold occurs primarily as free gold and invisible gold within the lattices of the disseminated arsenopyrite along the shear foliation planes of the host rock. The ore body geometry is 15–40 m wide and strikes 800 m in the NNW direction. Silicification, sericitization, chloritization, and sulphidation are the main alteration assemblages associated with the gold mineralization zones within the Josephine deposit. Pathfinder elements for gold are stibnite, tellurium, sulphur, copper, silver, and Lead.KEYWORDS: Deformationalterationmineralisationore bodyJosephine deposit AcknowledgementsThe authors would like to express their gratitude to Azumah Resources Limited, the owners of the Josephine deposit, for granting them access to the tenement and drill cores. Additionally, the authors would like to extend their sincere appreciation to the Agate project for providing financial support for this research through student scholarship awards received by the first author in 2021 and 2022.Disclosure statementNo potential conflict of interest was reported by the author(s).Additional informationFundingAdditionally, the authors would like to extend their sincere appreciation to the Agate project for providing financial support for this research through student scholarship awards received by the first author in 2021 and 2022.
{"title":"The geology and geochemistry of the Rhyacian Josephine gold deposit, Northwest Ghana","authors":"Fuseini Atanga, Prince Ofori Amponsah, Samuel Nunoo, Daniel Kwayisi, Eric Dominic Forson, Thomas Mba Akabzaa, Prosper Mckenzie Nude","doi":"10.1080/25726838.2023.2260583","DOIUrl":"https://doi.org/10.1080/25726838.2023.2260583","url":null,"abstract":"ABSTRACTThis paper focuses on the geology and geochemistry of the Rhyacian Josephine gold deposit in northwestern Ghana, where gold is primarily hosted in quartzites, with other lithologies observed, including granitoids, mafic intrusions, and gneisses. Four deformational events, DJO0, DJO1, DJO2, and DJO3, are observed. DJO0 is synonymous with the primary preserved sedimentary crossbedding in the quarzitic rocks. Gold mineralization within the deposit is mainly associated with the DJO1 NNW-trending dextral and steeply dipping sinusoidal shear zone. Gold occurs primarily as free gold and invisible gold within the lattices of the disseminated arsenopyrite along the shear foliation planes of the host rock. The ore body geometry is 15–40 m wide and strikes 800 m in the NNW direction. Silicification, sericitization, chloritization, and sulphidation are the main alteration assemblages associated with the gold mineralization zones within the Josephine deposit. Pathfinder elements for gold are stibnite, tellurium, sulphur, copper, silver, and Lead.KEYWORDS: Deformationalterationmineralisationore bodyJosephine deposit AcknowledgementsThe authors would like to express their gratitude to Azumah Resources Limited, the owners of the Josephine deposit, for granting them access to the tenement and drill cores. Additionally, the authors would like to extend their sincere appreciation to the Agate project for providing financial support for this research through student scholarship awards received by the first author in 2021 and 2022.Disclosure statementNo potential conflict of interest was reported by the author(s).Additional informationFundingAdditionally, the authors would like to extend their sincere appreciation to the Agate project for providing financial support for this research through student scholarship awards received by the first author in 2021 and 2022.","PeriodicalId":43298,"journal":{"name":"Applied Earth Science-Transactions of the Institutions of Mining and Metallurgy","volume":"42 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135193278","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-09-04DOI: 10.1080/25726838.2023.2253399
M. Abzalov, D. Renard
ABSTRACT The current paper presents case study of the Budenovskoe sandstone-hosted uranium deposit, the host sequence of which has been modelled geostatistically, using Plurigaussian conditional simulation (PGS) and Sequential Gaussian conditional simulation (SGS). The PGS method minimises subjectivism of the geological interpretations, by constraining the lithological models to geostatistical and lithostratigraphic characteristics of the host sequence, and accurately reproduces litho-stratigraphy of the sedimentary sequence, realistically conveying its complexity. This was integrated with the rock permeability generated using SGS. Integrating two models has significantly enhanced definition of the fluid infiltration passages in the host sequence. The model was built using stochastic algorithms of PGS and SGS, and therefore can be used for estimation the project risk. In practice, the errors, initially estimated to the blocks used for the conditional simulation, are grouped to the volumes of a practical interest, including the resource and reserve domains, production blocks and the leach cells.
{"title":"Plurigaussian conditional simulation (PGS) of the Budenovskoe uranium roll-front deposit, central Kazakhstan: 3D model of the host sedimentary sequence","authors":"M. Abzalov, D. Renard","doi":"10.1080/25726838.2023.2253399","DOIUrl":"https://doi.org/10.1080/25726838.2023.2253399","url":null,"abstract":"ABSTRACT The current paper presents case study of the Budenovskoe sandstone-hosted uranium deposit, the host sequence of which has been modelled geostatistically, using Plurigaussian conditional simulation (PGS) and Sequential Gaussian conditional simulation (SGS). The PGS method minimises subjectivism of the geological interpretations, by constraining the lithological models to geostatistical and lithostratigraphic characteristics of the host sequence, and accurately reproduces litho-stratigraphy of the sedimentary sequence, realistically conveying its complexity. This was integrated with the rock permeability generated using SGS. Integrating two models has significantly enhanced definition of the fluid infiltration passages in the host sequence. The model was built using stochastic algorithms of PGS and SGS, and therefore can be used for estimation the project risk. In practice, the errors, initially estimated to the blocks used for the conditional simulation, are grouped to the volumes of a practical interest, including the resource and reserve domains, production blocks and the leach cells.","PeriodicalId":43298,"journal":{"name":"Applied Earth Science-Transactions of the Institutions of Mining and Metallurgy","volume":" 7","pages":""},"PeriodicalIF":1.0,"publicationDate":"2023-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41311264","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-08-25DOI: 10.1080/25726838.2023.2244771
G. Saleh, G. A. Mohamed, A. E. El Tohamy
ABSTRACT The investigated Phanerozoic volcanic (Gabal Um Itly, G. El Beida, G. Um Domi and G. Um Doweila) areas in the south Eastern Desert of Egypt of the Northern Arabian-Nubian Shield (ANS), have been a peralkaline affinity and display a continuous composition trachyte rocks. Geochemically, the studied rocks show significant negative anomalies in Ba, Sr, and Ti on the primitive mantle normalized trace element plot, indicating an ancestry involving plagioclase and Fe-Ti oxide fractionation. The concentrations of uranium mineralization and rare earth elements in the trachyte rocks is related to the presence of uranophane, kasolite, umohoite, autunite, monazite and allanite. The distribution of uranium, thorium and their ratios in the trachyte rocks reflects a direct strong relation, which suggests that U distribution is, at least in part, governed primarily by magmatic processes and disturbed later by a hydrothermal solution.
{"title":"Petrogenesis and geological implications of the trachytic rocks in the South Eastern Desert, Egypt: mineralogical, geochemical, and radioactivity insights","authors":"G. Saleh, G. A. Mohamed, A. E. El Tohamy","doi":"10.1080/25726838.2023.2244771","DOIUrl":"https://doi.org/10.1080/25726838.2023.2244771","url":null,"abstract":"ABSTRACT The investigated Phanerozoic volcanic (Gabal Um Itly, G. El Beida, G. Um Domi and G. Um Doweila) areas in the south Eastern Desert of Egypt of the Northern Arabian-Nubian Shield (ANS), have been a peralkaline affinity and display a continuous composition trachyte rocks. Geochemically, the studied rocks show significant negative anomalies in Ba, Sr, and Ti on the primitive mantle normalized trace element plot, indicating an ancestry involving plagioclase and Fe-Ti oxide fractionation. The concentrations of uranium mineralization and rare earth elements in the trachyte rocks is related to the presence of uranophane, kasolite, umohoite, autunite, monazite and allanite. The distribution of uranium, thorium and their ratios in the trachyte rocks reflects a direct strong relation, which suggests that U distribution is, at least in part, governed primarily by magmatic processes and disturbed later by a hydrothermal solution.","PeriodicalId":43298,"journal":{"name":"Applied Earth Science-Transactions of the Institutions of Mining and Metallurgy","volume":" ","pages":""},"PeriodicalIF":1.0,"publicationDate":"2023-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44979023","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-08-14DOI: 10.1080/25726838.2023.2244775
V. Rocha, M. A. A. Bassani
ABSTRACT The classification of mineral resources is crucial for public disclosure and is used to evaluate the risk associated with the mineral deposit, enabling informed decisions. To address this need, this study proposes the use of a multi-layer scorecard workflow (MLSW) for mineral resource classification that considers multiple factors from different disciplines. This approach is highly flexible as the competent user may adapt the scorecard workflow to the particularities of each deposit. In this paper, we considered classical metrics for resource classification, such as the number of samples, the slope of regression, kriging efficiency, and kriging variance, combinedwith more modern ones (Risk Index), which contemplates the combination of the estimation error, and geological continuity by a probabilistic approach. The methodology can also incorporate qualitative information such as the geological complexity. The proposed workflow has been applied in two different databases, demonstrating its transparency, auditability, and applicability.
{"title":"Practical application of a multi-layer scorecard workflow (MLSW) for comprehensive mineral resource classification","authors":"V. Rocha, M. A. A. Bassani","doi":"10.1080/25726838.2023.2244775","DOIUrl":"https://doi.org/10.1080/25726838.2023.2244775","url":null,"abstract":"ABSTRACT The classification of mineral resources is crucial for public disclosure and is used to evaluate the risk associated with the mineral deposit, enabling informed decisions. To address this need, this study proposes the use of a multi-layer scorecard workflow (MLSW) for mineral resource classification that considers multiple factors from different disciplines. This approach is highly flexible as the competent user may adapt the scorecard workflow to the particularities of each deposit. In this paper, we considered classical metrics for resource classification, such as the number of samples, the slope of regression, kriging efficiency, and kriging variance, combinedwith more modern ones (Risk Index), which contemplates the combination of the estimation error, and geological continuity by a probabilistic approach. The methodology can also incorporate qualitative information such as the geological complexity. The proposed workflow has been applied in two different databases, demonstrating its transparency, auditability, and applicability.","PeriodicalId":43298,"journal":{"name":"Applied Earth Science-Transactions of the Institutions of Mining and Metallurgy","volume":" ","pages":""},"PeriodicalIF":1.0,"publicationDate":"2023-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44017186","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-07-29DOI: 10.1080/25726838.2023.2240692
Tamer G. Mohamed, Mostafa Hassan, M. A. Ismail, A. El-Midany, M. G. El-Samrah
ABSTRACT Black sands represent a good source of economic minerals with various industrial applications. However, their radioactive properties may prevent their use in specific applications. In this study, zircon, ilmenite, magnetite, and rutile are four minerals represent more than 75% of the black sand content, were selected to evaluate their Intrinsic radiological properties. The chemical composition of these minerals was determined along with their density and particle size. Then, the activity concentrations of the naturally occurring radioactive nuclides were experimentally determined and the most important radiological hazard indices were calculated. The results indicated that the upgrading process concentrates the natural radioisotopes in some minerals like the zircon and rutile leaving the magnetite and ilmenite with lower content than permissible limits. Moreover, the risk analysis identified the dangerous conditions and situations and suggest possible solutions to reduce these hazardous situations to a minimum and to keep a safe environment for the workers.
{"title":"Risk assessment of radioactive hazards associated with black sand upgrading processes","authors":"Tamer G. Mohamed, Mostafa Hassan, M. A. Ismail, A. El-Midany, M. G. El-Samrah","doi":"10.1080/25726838.2023.2240692","DOIUrl":"https://doi.org/10.1080/25726838.2023.2240692","url":null,"abstract":"ABSTRACT Black sands represent a good source of economic minerals with various industrial applications. However, their radioactive properties may prevent their use in specific applications. In this study, zircon, ilmenite, magnetite, and rutile are four minerals represent more than 75% of the black sand content, were selected to evaluate their Intrinsic radiological properties. The chemical composition of these minerals was determined along with their density and particle size. Then, the activity concentrations of the naturally occurring radioactive nuclides were experimentally determined and the most important radiological hazard indices were calculated. The results indicated that the upgrading process concentrates the natural radioisotopes in some minerals like the zircon and rutile leaving the magnetite and ilmenite with lower content than permissible limits. Moreover, the risk analysis identified the dangerous conditions and situations and suggest possible solutions to reduce these hazardous situations to a minimum and to keep a safe environment for the workers.","PeriodicalId":43298,"journal":{"name":"Applied Earth Science-Transactions of the Institutions of Mining and Metallurgy","volume":" ","pages":""},"PeriodicalIF":1.0,"publicationDate":"2023-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47801074","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-07-24DOI: 10.1080/25726838.2023.2237370
Vanshika Bhardwaj, Kanwarpreet Singh
ABSTRACT Landslides are the most prevalent natural hazard in hilly regions of India. This study examines the landslide susceptibility of the Pithoragarh, Uttarakhand, India, using multi-criteria decision based analysis by analytical hierarchy process (AHP), and logistic regression (LR) analysis. The LSZ modelling was performed using fourteen landslide causative factors. Based on past landslide data, landslide locations were identified, which were further divided into a 70/30 ratio, with 70 representing training and 30 representing validation. Validation of the findings of the predicted maps of landslide susceptibility using Area under Curve (AUC) indicates that the predicted map using the LR approach has the highest prediction rate compared to other methods used for landslide susceptibility prediction. Also, validation of all the models was done using Landslide Density Index (LDI) which shows the validity of all models. Thus, the results of all models can be used to predict landslide susceptibility in Pithoragarh.
{"title":"Assessment of landslide susceptibility of Pithoragarh, Uttarakhand (India) using logistic regression and multi-criteria decision-based analysis by analytical hierarchy process","authors":"Vanshika Bhardwaj, Kanwarpreet Singh","doi":"10.1080/25726838.2023.2237370","DOIUrl":"https://doi.org/10.1080/25726838.2023.2237370","url":null,"abstract":"ABSTRACT Landslides are the most prevalent natural hazard in hilly regions of India. This study examines the landslide susceptibility of the Pithoragarh, Uttarakhand, India, using multi-criteria decision based analysis by analytical hierarchy process (AHP), and logistic regression (LR) analysis. The LSZ modelling was performed using fourteen landslide causative factors. Based on past landslide data, landslide locations were identified, which were further divided into a 70/30 ratio, with 70 representing training and 30 representing validation. Validation of the findings of the predicted maps of landslide susceptibility using Area under Curve (AUC) indicates that the predicted map using the LR approach has the highest prediction rate compared to other methods used for landslide susceptibility prediction. Also, validation of all the models was done using Landslide Density Index (LDI) which shows the validity of all models. Thus, the results of all models can be used to predict landslide susceptibility in Pithoragarh.","PeriodicalId":43298,"journal":{"name":"Applied Earth Science-Transactions of the Institutions of Mining and Metallurgy","volume":" ","pages":""},"PeriodicalIF":1.0,"publicationDate":"2023-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42918301","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-07-24DOI: 10.1080/25726838.2023.2236451
Andre Diego Lima de Montalvão Barretto, M. Tupinambá, M. Heilbron, L. Bertolino, Flávio Rocha
ABSTRACT The present work sought to investigate the applicability of the microCT scanning beyond petrophysics in oil and gas industry. We analysed external features (morphology) with all their nuances, and internal features such as mineral inclusions and vugs, in micrometric alluvial gold grains from one of the largest rivers in Southeastern Brazil. Owing to the complicated X-ray interactions with any metallic material, mainly gold, several imaging protocols were used until obtaining the most appropriate one. The results corroborate that microCT scanning can be a useful tool in provenance studies of detrital gold grains, even in an adverse analytical context and with small gold grain populations.
{"title":"Gold single-grain microCT scanning: operational constraints and first results in Brazilian alluvial grains","authors":"Andre Diego Lima de Montalvão Barretto, M. Tupinambá, M. Heilbron, L. Bertolino, Flávio Rocha","doi":"10.1080/25726838.2023.2236451","DOIUrl":"https://doi.org/10.1080/25726838.2023.2236451","url":null,"abstract":"ABSTRACT The present work sought to investigate the applicability of the microCT scanning beyond petrophysics in oil and gas industry. We analysed external features (morphology) with all their nuances, and internal features such as mineral inclusions and vugs, in micrometric alluvial gold grains from one of the largest rivers in Southeastern Brazil. Owing to the complicated X-ray interactions with any metallic material, mainly gold, several imaging protocols were used until obtaining the most appropriate one. The results corroborate that microCT scanning can be a useful tool in provenance studies of detrital gold grains, even in an adverse analytical context and with small gold grain populations.","PeriodicalId":43298,"journal":{"name":"Applied Earth Science-Transactions of the Institutions of Mining and Metallurgy","volume":" ","pages":""},"PeriodicalIF":1.0,"publicationDate":"2023-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42928565","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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