Geochemistry-Exploration Environment Analysis最新文献

{"title":"On the use of LIBS data for mineralogical investigations – constraints and application of a clustering method","authors":"F. Fontana, B. van der Hoek, Jessica Stromberg, C. Tiddy, N. Francis, S. Tassios, Y. Uvarova","doi":"10.1144/geochem2023-003","DOIUrl":"https://doi.org/10.1144/geochem2023-003","url":null,"abstract":"This study examines how LIBS data collected using a downhole deployable LIBS prototype for geochemical analysis in a fashion that imitates downhole deployment may be used for mineralogical investigations. Two chemically and mineralogically practically identical felsic rocks, namely granite and microgranite are used to assess the effects of rock texture on mineral classification and high-resolution SEM-TIMA mineral maps are used to reveal mineralogical composition of each LIBS ablation crater. Additionally, in order to extend the LIBS application for fast mineralogical studies to a greenfield scenario (i.e., no previous knowledge) a clustering methodology is presented for mineralogical classification from LIBS data. Results indicate that most LIBS spot analyses sample mineral mixtures, 91.2% and 100% for granite and microgranite, respectively, which challenges mineralogical classification, particularly for fine-grained rocks. Positive identification and classification of minerals of slightly different compositions relative to the bulk rock (i.e., fluorite and biotite in granitic rocks) demonstrates how minerals or minerals groups of distinct and interesting chemical compositions (e.g., sulphides or oxides in silicate dominated rocks) can be rapidly recognised in a mineral exploration scenario. Strategies for overcoming mineral mixture issues are presented and recommendations are given for effective workflows for mineralogical analysis using LIBS data in different mineral exploration stages.\u0000 \u0000 Supplementary material:\u0000 https://doi.org/10.6084/m9.figshare.c.6444482\u0000","PeriodicalId":55114,"journal":{"name":"Geochemistry-Exploration Environment Analysis","volume":" ","pages":""},"PeriodicalIF":2.4,"publicationDate":"2023-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42852279","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparison of main and accompanying metals distribution patterns in newly documented deposits of the Northern Copper Belt in Poland","authors":"A. Pietrzela, T. Bieńko","doi":"10.1144/geochem2022-046","DOIUrl":"https://doi.org/10.1144/geochem2022-046","url":null,"abstract":"\u0000 Three new world-class sediment-hosted stratiform copper deposits have recently been documented in SW Poland, in the deep parts of the Fore-Sudetic Monocline: Nowa Sól, Sulmierzyce North and Mozów. Along with the adjacent prognostic areas, these deposits form an extensive W-E trending belt, distant from the well-known deposits of the Sieroszowice-Lubin area and referred to as the Northern Copper Belt. This major discovery was a result of an exploration program performed by the Canadian Miedzi Copper Corporation, which involved studies of archival data and the company's own drilling program. Investigation of the core material included microscopic observations of thin sections and chemical analyzes using the ICP-MS and/or ICP-OES method. The aim of this study was to compare available geochemical data from the documented deposits and determine the distribution patterns of the main and accompanying metals. Particular attention was paid to Cu, Ag, Pb, Zn, Co, Ni, Mo, V and Au. Each of the studied deposits is characterized by a different position of the ore mineralization in the lithological profile. Average concentrations of analyzed elements and their distribution in the ore series, both vertically and laterally, indicate that distinct mineralizing systems were responsible for the formation of each orebody. Among the main factors influencing metal distribution in analyzed deposits are: the spatial range of the epigenetic, oxidized\u0000 Rote Fäule\u0000 facies; composition and thickness of the source rocks for the mineralizing brines; tectonics.\u0000","PeriodicalId":55114,"journal":{"name":"Geochemistry-Exploration Environment Analysis","volume":" ","pages":""},"PeriodicalIF":2.4,"publicationDate":"2023-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45022158","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Introduction to the thematic collection: a review of continental-scale geochemical mapping projects in Australia, Europe, and the conterminous United States","authors":"David B. Smith, P. de Caritat, C. Reimann","doi":"10.1144/geochem2022-067","DOIUrl":"https://doi.org/10.1144/geochem2022-067","url":null,"abstract":"","PeriodicalId":55114,"journal":{"name":"Geochemistry-Exploration Environment Analysis","volume":" ","pages":""},"PeriodicalIF":2.4,"publicationDate":"2023-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46981463","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Distribution and attribute analysis of soil selenium in Hebei Province, China","authors":"Liting Zhang, Weiming Xie, Wenlong Yu, Li Zhang, Shicong Zhang, Xi Wang, Xiaoyang Xie, Hangxin Cheng","doi":"10.1144/geochem2022-055","DOIUrl":"https://doi.org/10.1144/geochem2022-055","url":null,"abstract":"From 2004 to 2018, approximately 73% of the land area in Hebei province was surveyed by a 1:250,000 land quality geochemical survey of the National Geochemistry Survey of Land Quality project (NGSLQ). Based on the topsoil (0-20 cm) datasets (50724 analysis samples) and attribute analysis of the key area with a semivariance function model, geographic detector model and random forest model, the content and spatial distribution of soil selenium (Se) in Hebei province and the influencing factors of the distribution of Se in the Shijiazhuang-Xingtai-Handan area were obtained. The soil Se content in Hebei Province is low, ranging from 0.02 to 3.23 mg/kg, with an average of 0.20 mg/kg. The spatial distribution of soil Se was heterogeneous, and the marginal Se (0.125-0.175mg/kg) area and the sufficient Se (0.175-0.40 mg/kg) area were widely distributed, but the acreage of the Se-rich (0.40-3.0 mg/kg) area was very limited, accounting for only 2.43% of the total survey area. However, the Shijiazhuang-Xingtai-Handan area was a significant Se enrichment area. The spatial distribution of Se in the Shijiazhuang-Xingtai-Handan area was restricted by natural factors and socioeconomic factors. Soil organic matter (SOM) was the most influential factor and showed good coordination with Se. Coal burning superimposed on natural factors promotes the spatial differentiation of soil Se to a certain extent.","PeriodicalId":55114,"journal":{"name":"Geochemistry-Exploration Environment Analysis","volume":" ","pages":""},"PeriodicalIF":2.4,"publicationDate":"2023-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48773775","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Thallium isotopes as indicators of ore mineralization at the Zn-rich sediment-hosted massive sulfide TL Deposit, British Columbia, Canada","authors":"D. Knaack, K. Sullivan, M. Leybourne, C. Dunn, D. Layton-Matthews","doi":"10.1144/geochem2022-042","DOIUrl":"https://doi.org/10.1144/geochem2022-042","url":null,"abstract":"\u0000 Few studies have focused on the application of the Tl isotopic system for geochemical exploration. We report\u0000 \u0000 \u0000 ε\u0000 \u0000 \u0000 205\u0000 Tl values of rock samples from the TL Deposit, British Columbia, Canada - a sediment-hosted massive sulfide (SHMS) deposit with characteristics of a Broken Hill-type deposit - and investigate relationships with major and trace element geochemistry. Maps generated using Tl isotope and trace element data indicate that\u0000 \u0000 \u0000 ε\u0000 \u0000 \u0000 205\u0000 Tl values can potentially be used to fingerprint ore mineralization at the TL Deposit. The sources of Tl and other metals (Ag, Pb, Zn) are assessed using Tl isotope data. Measured\u0000 \u0000 \u0000 ε\u0000 \u0000 \u0000 205\u0000 Tl values exhibit positive correlations with Pb, sedimentary exhalative (SEDEX) metal index (Zn+100*Pb+100*Tl), and the redox proxy, U/Th, and negative correlations with Be, Cd, Ce, La, Ni, and Th. Individual lithologies have distinct Tl isotopic compositions. Metal-rich heavily altered samples have relatively high\u0000 \u0000 \u0000 ε\u0000 \u0000 \u0000 205\u0000 Tl values (-5.0 to -2.5\u0000 \u0000 \u0000 ε\u0000 \u0000 \u0000 -units) reflecting the euxinic conditions of the global Paleoproterozoic ocean and hydrothermal influence. Samples with lower\u0000 \u0000 \u0000 ε\u0000 \u0000 \u0000 205\u0000 Tl values (-15 to -7.6\u0000 \u0000 \u0000 ε\u0000 \u0000 \u0000 -units) reflect a combination of their mineralogy (phyllosilicate minerals such as biotite and clinochlore), Tl from sediments reflecting the Tl isotopic composition of modern seawater, and possible low-temperature alteration processes. Samples with high Pb and Ag contents have high\u0000 \u0000 \u0000 ε\u0000 \u0000 \u0000 205\u0000 Tl values, indicating a hydrothermal origin of these metals, whereas Zn is highest in samples with low\u0000 \u0000 \u0000 ε\u0000 \u0000 \u0000 205\u0000 Tl values, indicating a low-temperature or sedimentary origin. Thallium isotopes, paired with conventional geochemical data, show promise as a useful tool for exploration of SHMS deposits with Broken Hill-type characteristics.\u0000 \u0000 \u0000 Thematic collection:\u0000 This article is part of the Geochemical processes related to mined, milled, or natural metal deposits collection available at:\u0000 https://www.lyellcollection.org/topic/collections/geochemical-processes-related-to-mined-milled-or-natural-metal-deposits\u0000 \u0000 \u0000 Supplementary material:\u0000 https://doi.org/10.6084/m9.figshare.c.6370671\u0000","PeriodicalId":55114,"journal":{"name":"Geochemistry-Exploration Environment Analysis","volume":" ","pages":""},"PeriodicalIF":2.4,"publicationDate":"2023-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46013873","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Introduction to the thematic collection: Applications of innovations in geochemical data analysis","authors":"Wenlei Wang, S. Xie, E. Carranza","doi":"10.1144/geochem2022-058","DOIUrl":"https://doi.org/10.1144/geochem2022-058","url":null,"abstract":"Geochemistry: Exploration, Environment, Analysis (GEEA) as the scientific journal of the AAG focuses on the use of geochemistry in mineral exploration/resource development. Since the first issue of GEEA was published in 2001, there have been hundreds of papers regarding methodologies for geochemical data analysis. In 2017, a thematic issue: analysis of exploration geochemical data for mapping of anomalies (Carranza and Zuo, 2017) was published on the development of methods and techniques for exploration geochemical data analysis. As a successor, this current thematic set of papers introduces some new progress and advancements in geochemical data analysis, e.g., nonlinear, fractal/multifractal, multi-statistical, machine learning methods and their applications in mineral exploration. Twelve papers from Professor Qiuming Cheng's colleagues in China and Canada are organized in this thematic set in honor of his Gold Medal Award.\u0000 \u0000 Thematic collection:\u0000 This article is part of the Applications of Innovations in Geochemical Data Analysis collection available at:\u0000 https://www.lyellcollection.org/topic/collections/applications-of-innovations-in-geochemical-data-analysis\u0000","PeriodicalId":55114,"journal":{"name":"Geochemistry-Exploration Environment Analysis","volume":" ","pages":""},"PeriodicalIF":2.4,"publicationDate":"2022-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44466060","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Lithogeochemistry in exploration for intrusion-hosted magmatic Ni-Cu-Co deposits","authors":"S. Barnes","doi":"10.1144/geochem2022-025","DOIUrl":"https://doi.org/10.1144/geochem2022-025","url":null,"abstract":"\u0000 Magmatic Ni-Cu-Co-PGE deposits are notoriously difficult exploration targets owing to a lack of alteration haloes or other extended distal footprints. Success requires prediction of prospective terranes, followed by identification of suitable host intrusions and deposition sites within those intrusions. At the regional scale, potential ore-hosting magmas tend to have lithophile trace element trends falling on mixing lines between primitive or slightly depleted source mantle and typical upper continental crust, with several significant exceptions. Most known deposits have parent magmas that are in the upper range of FeO content for given MgO compared with baseline data sets for continental LIP magmas. At the scale of individual intrusions, the presence of cumulate rocks, both mafic and ultramafic, is key. These can be recognised in regional datasets using combinations of magnesium number (molar MgO/(MgO+FeO), Al\u0000 2\u0000 O\u0000 3\u0000 , TiO\u0000 2\u0000 and Zr contents. Combinations of alteration-resistant element ratios between Ni, Cr and Ti are also useful and can also be applied to moderately weathered samples. Concentrations and ratios of Cu and Zr are useful in discriminating chalcophile-enriched and depleted magmas suites. In combination, these approaches can be combined to discriminate highly prospective cumulate-dominated magmatic suites and individual intrusions from non-cumulate suites with limited potential.\u0000 \u0000 \u0000 Supplementary material:\u0000 https://doi.org/10.6084/m9.figshare.c.6267664\u0000","PeriodicalId":55114,"journal":{"name":"Geochemistry-Exploration Environment Analysis","volume":" ","pages":""},"PeriodicalIF":2.4,"publicationDate":"2022-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43515665","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The National Geochemical Survey of Australia: review and impact","authors":"P. de Caritat","doi":"10.1144/geochem2022-032","DOIUrl":"https://doi.org/10.1144/geochem2022-032","url":null,"abstract":"The National Geochemical Survey of Australia (NGSA) is Australia's first national-scale geochemical survey. It was delivered to the public on 30 June 2011, after almost five years of stakeholder engagement, strategic planning, sample collection, preparation and analysis, quality assurance/quality control, and preliminary data analytics. The project was comprehensively documented in seven initial open-file reports and six data and map sets, followed over the next decade by more than 70 well-cited scientific publications. This review compiles the body of work and knowledge that emanated from the project to-date as an indication of the impact the NGSA had over the decade 2011-2021. The geochemical fabric of Australia as never seen before has been revealed by the NGSA. This has spurred further research and stimulated the mineral exploration industry. This paper also critically looks at operational decisions taken at project time (2007-2011) that were good and perhaps – with the benefit of hindsight – not so good, with the intention of providing experiential advice for any future large-scale geochemical survey of Australia or elsewhere. We conclude that the NGSA was a low-cost, high-benefit project that delivered scientific excellence, promoted stakeholder engagement, demonstrated national leadership, and contributed to enhanced national resource wealth.\u0000 \u0000 Thematic collection:\u0000 This article is part of the Continental-scale geochemical mapping collection available at:\u0000 https://www.lyellcollection.org/topic/collections/continental-scale-geochemical-mapping\u0000","PeriodicalId":55114,"journal":{"name":"Geochemistry-Exploration Environment Analysis","volume":" ","pages":""},"PeriodicalIF":2.4,"publicationDate":"2022-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49168629","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Study on the direction effect of terrane accretive orogeny and biological evolution during the Jinning-Chengjiang period in the northwestern margin of the Yangtze block","authors":"Rui Yan, Zuanyun Yang, Yuanjun Wang, Shaoping Yang","doi":"10.1144/geochem2021-044","DOIUrl":"https://doi.org/10.1144/geochem2021-044","url":null,"abstract":"In the various stages from life chemistry to biological evolution, major geological events are usually accompanied by the extinction of species and the gestation of new life, which are important factors that determine the direction of ecological evolution. The study of the terrane accretive orogeny during the Jinning-Chengjiang period has had a great impact on the crustal rock composition, the atmospheric environment, and the water circulation system, etc. The living environment of the primitive biological community has undergone tremendous changes, the crust to produce superimposed contraction and extensional rift effect, resulting in collisional magmatic activity and strong earthquakes, and a large number of species have been extinct. In turn, biological activities and organic matter also contributed significantly to the migration. With the periodic cycle of geological processes and being fully utilized by nature, the origin and evolution of life grow in a spiral. Based on the analysis of the petrochemical composition characteristics of metamorphic volcanic-sedimentary rock series and intermediate-acid intrusive rocks in Pengguan terrane, this article believes that the subduction mechanism of oceanic crust in the study area is formed by the northwest subduction of the Longmenshan-Anning oceanic crust on the southeast side. The relationship among the average change of chemical composition of the diabase in Masongling and Xinkaidong area and around the world, ion radius and compressibility shows that when the element ion compressibility is less than 4.46, compared with the average chemical composition of the diabase in the world, the oxide content such as Si, Ti, Al and P is obviously lower, while when the ion compressibility is equal to or greater than 4.46, the content of oxide of Fe, Mn, Mg and K increases obviously except Ca and Na.","PeriodicalId":55114,"journal":{"name":"Geochemistry-Exploration Environment Analysis","volume":" ","pages":""},"PeriodicalIF":2.4,"publicationDate":"2022-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43528387","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Modeling spatial uncertainty of geochemical anomalies using fractal and sequential indicator simulation methods","authors":"Haicheng Wang, R. Zuo, E. Carranza, N. Madani","doi":"10.1144/geochem2022-029","DOIUrl":"https://doi.org/10.1144/geochem2022-029","url":null,"abstract":"Mapping of geochemical anomalies is crucial to exploration and environmental geochemistry. The complex geochemical landscape, multiple geological sources and various secondary surficial processes impose a certain degree of spatial uncertainty in mapping of geochemical anomalies. Quantifying such uncertainty is significant for improving the efficiency of environmental monitoring or mineral prospecting. In this paper, sequential indicator simulation (SISIM) was used to assess local and spatial uncertainties of geochemical anomalies, and the concentration–area (C–A) fractal model was employed to determine geochemical threshold prior to SISIM analysis. To illustrate uncertainty of Ag geochemical anomalies, Ag concentration data of 1,880 soil samples collected from northeast of Dong Ujimqin Banner district of Inner Mongolia, North China, was used in this study. Based on a set of simulation realizations of Ag concentrations, it was concluded that areas with low local (i.e., single location) uncertainty of Ag concentrations have low risk for mineral exploration. However, the spatial uncertainty for multi-locations showed that the joint probability statistics were stricter than local uncertainty. Therefore, combining local probability and spatial joint probability for delineating geochemical anomalies of Ag is more acceptable and reliable. The hybrid approach using C–A fractal model and SISIM provides a new way to delineate anomalous areas considering uncertainty of spatial distributions of geochemical elements.\u0000 \u0000 Thematic collection:\u0000 This article is part of the Applications of Innovations in Geochemical Data Analysis collection available at:\u0000 https://www.lyellcollection.org/topic/collections/applications-of-innovations-in-geochemical-data-analysis\u0000","PeriodicalId":55114,"journal":{"name":"Geochemistry-Exploration Environment Analysis","volume":"1 1","pages":""},"PeriodicalIF":2.4,"publicationDate":"2022-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41318014","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}