Pub Date : 2026-01-02DOI: 10.1016/j.oreoa.2026.100122
Bernard Che Ngu , Kennedy Folepai Fozao , Mathias Akong Onabid , Lionel Takem Nkwanyang , Zerubbabel Akongneh
Accurate hydrocarbon reserve estimation is critical yet challenging in the complex Niger Delta Basin. This study employs a novel adaptive Physics-Informed Neural Network (PINN) to improve reservoir characterization and Hydrocarbon Initially In Place (HIIP) predictions. Core data from Well J-2 (average porosity 0.25, permeability 516.01 mD) served as the calibration baseline. A linear model (gradient 1.057, intercept −0.0077) calibrated well log porosity for uncored wells, identifying three rock types with RT2 being dominant. The reservoir exhibits significant heterogeneity, with average shale volumes ranging from 0.18 to 0.41. Zonal analysis reveals high hydrocarbon potential in Wells J-1, J-3, and J-4, characterized by low water saturation (0.16–0.19) and high Net-to-Gross (NTG) values, notably in J-1 (0.85) and J-3 (0.72). Conversely, J-2 and J-5 show higher water saturation (0.57 and 0.98, respectively). Complexity and uncertainty scores were used to guide adaptive sampling. The complexity score averaged 16, peaking at 87.7 in the western sector, while model uncertainty remained negligible (<0.0005). A 100,000-iteration Monte Carlo simulation, grounded in these physics-guided distributions, yielded a realistic HIIP estimate of 65.96 MMbbl. Results indicate that the western reservoir sector, defined by higher permeability and NTG values, represents the optimal target for future development.
{"title":"Uncertainty quantification in 3D static modeling: Improving reserve estimation accuracy with adaptive physics-informed Monte Carlo simulation in Y-field, Niger Delta Basin, Nigeria","authors":"Bernard Che Ngu , Kennedy Folepai Fozao , Mathias Akong Onabid , Lionel Takem Nkwanyang , Zerubbabel Akongneh","doi":"10.1016/j.oreoa.2026.100122","DOIUrl":"10.1016/j.oreoa.2026.100122","url":null,"abstract":"<div><div>Accurate hydrocarbon reserve estimation is critical yet challenging in the complex Niger Delta Basin. This study employs a novel adaptive Physics-Informed Neural Network (PINN) to improve reservoir characterization and Hydrocarbon Initially In Place (HIIP) predictions. Core data from Well J-2 (average porosity 0.25, permeability 516.01 mD) served as the calibration baseline. A linear model (gradient 1.057, intercept −0.0077) calibrated well log porosity for uncored wells, identifying three rock types with RT2 being dominant. The reservoir exhibits significant heterogeneity, with average shale volumes ranging from 0.18 to 0.41. Zonal analysis reveals high hydrocarbon potential in Wells J-1, J-3, and J-4, characterized by low water saturation (0.16–0.19) and high Net-to-Gross (NTG) values, notably in J-1 (0.85) and J-3 (0.72). Conversely, J-2 and J-5 show higher water saturation (0.57 and 0.98, respectively). Complexity and uncertainty scores were used to guide adaptive sampling. The complexity score averaged 16, peaking at 87.7 in the western sector, while model uncertainty remained negligible (<0.0005). A 100,000-iteration Monte Carlo simulation, grounded in these physics-guided distributions, yielded a realistic HIIP estimate of 65.96 MMbbl. Results indicate that the western reservoir sector, defined by higher permeability and NTG values, represents the optimal target for future development.</div></div>","PeriodicalId":100993,"journal":{"name":"Ore and Energy Resource Geology","volume":"20 ","pages":"Article 100122"},"PeriodicalIF":0.0,"publicationDate":"2026-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145915119","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 : 2025-10-01DOI: 10.1016/j.oreoa.2025.100120
Hakundwi Mandende , Themba Mothupi
Magmatic apatite-oxide ore deposits within layered intrusions often contain significant resources of metals critical for the green energy transition, battery storage technologies, and food security such as titanium, iron, vanadium, phosphate, and rare earth elements. The Upper Zone (UZ) of the Bushveld Complex is known to contain significant resources of apatite-ilmenite mineralization. Despite the enormous economic potential, detailed mineralogical evaluation of the apatite-rich layers is still lacking. This study aims to use automated mineralogy (QEMSCAN®) to evaluate the key process mineralogy parameters essential for designing an effective beneficiation process for the Upper Apatite-rich Zone (UAZ) in the UZ, Northern Limb of the Bushveld Complex.
A detailed mineralogical study was undertaken on a 3 m composite sample of half drill cores from the Bellevue drill core with head grades of 3 wt.% P₂O₅, 37 wt.% Fe₂O₃, 6 wt.% TiO₂, and 32 wt.% SiO₂. Mineralogical analysis revealed the sample's major components as plagioclase (∼22%), orthopyroxene (∼22%), olivine (∼9%), ilmenite (∼9%), titanomagnetite (∼9%), mica (∼8%), and apatite (∼7%). Apatite showed excellent liberation characteristics, particularly in the finer fractions: in the -212/+45 µm and -45 µm size fractions, over 90% of apatite particles were liberated or free. The remaining locked apatite particles were primarily associated with orthopyroxene, mica, plagioclase, titanomagnetite, and amphibole. Similarly, ilmenite and titanomagnetite were well-liberated in finer fractions, with 77–90% of these minerals being free or exposed. Ilmenite and titanomagnetite consistently showed high degrees of association across all size fractions. The P50 and P80 values for apatite, ilmenite, and titanomagnetite suggest that excessive grinding beyond 45 µm does not significantly improve liberation and may lead to sliming, negatively impacting recovery. Thus, optimal grinding is proposed between 45 and 212 µm to maximize liberation without risking processing efficiency.
Based on the mineralogical findings, a combination of magnetic separation and froth flotation is recommended for beneficiation. Magnetic separation is ideal for recovering Fe-Ti oxides (ilmenite and magnetite), while froth flotation is suitable for apatite recovery. Gravity separation may be less effective due to potential contamination. Minerals like fayalite (olivine) and orthopyroxene have similar specific gravities to ilmenite and magnetite, risking dilution of the ilmenite and magnetite concentrates. Similarly, iron-rich biotite and hornblende share specific gravities with apatite, possibly contaminating the apatite concentrate with Fe, Si, Ca, Al, Mg, Ti, and K. Such impurities could complicate downstream processing, particularly for phosphate fertilizer or phosphoric acid production. Therefore, a process that involves comminution to less than 212 μm, followed by magnetic separation to recover Fe-Ti oxides
{"title":"Quantitative mineralogical characterization of the Upper Apatite-Rich Zone of the Bushveld Complex using QEMSCAN®: Implications for mineral processing of apatite, ilmenite, and titanomagnetite ore minerals","authors":"Hakundwi Mandende , Themba Mothupi","doi":"10.1016/j.oreoa.2025.100120","DOIUrl":"10.1016/j.oreoa.2025.100120","url":null,"abstract":"<div><div>Magmatic apatite-oxide ore deposits within layered intrusions often contain significant resources of metals critical for the green energy transition, battery storage technologies, and food security such as titanium, iron, vanadium, phosphate, and rare earth elements. The Upper Zone (UZ) of the Bushveld Complex is known to contain significant resources of apatite-ilmenite mineralization. Despite the enormous economic potential, detailed mineralogical evaluation of the apatite-rich layers is still lacking. This study aims to use automated mineralogy (QEMSCAN®) to evaluate the key process mineralogy parameters essential for designing an effective beneficiation process for the Upper Apatite-rich Zone (UAZ) in the UZ, Northern Limb of the Bushveld Complex.</div><div>A detailed mineralogical study was undertaken on a 3 m composite sample of half drill cores from the Bellevue drill core with head grades of 3 wt.% P₂O₅, 37 wt.% Fe₂O₃, 6 wt.% TiO₂, and 32 wt.% SiO₂. Mineralogical analysis revealed the sample's major components as plagioclase (∼22%), orthopyroxene (∼22%), olivine (∼9%), ilmenite (∼9%), titanomagnetite (∼9%), mica (∼8%), and apatite (∼7%). Apatite showed excellent liberation characteristics, particularly in the finer fractions: in the -212/+45 µm and -45 µm size fractions, over 90% of apatite particles were liberated or free. The remaining locked apatite particles were primarily associated with orthopyroxene, mica, plagioclase, titanomagnetite, and amphibole. Similarly, ilmenite and titanomagnetite were well-liberated in finer fractions, with 77–90% of these minerals being free or exposed. Ilmenite and titanomagnetite consistently showed high degrees of association across all size fractions. The P50 and P80 values for apatite, ilmenite, and titanomagnetite suggest that excessive grinding beyond 45 µm does not significantly improve liberation and may lead to sliming, negatively impacting recovery. Thus, optimal grinding is proposed between 45 and 212 µm to maximize liberation without risking processing efficiency.</div><div>Based on the mineralogical findings, a combination of magnetic separation and froth flotation is recommended for beneficiation. Magnetic separation is ideal for recovering Fe-Ti oxides (ilmenite and magnetite), while froth flotation is suitable for apatite recovery. Gravity separation may be less effective due to potential contamination. Minerals like fayalite (olivine) and orthopyroxene have similar specific gravities to ilmenite and magnetite, risking dilution of the ilmenite and magnetite concentrates. Similarly, iron-rich biotite and hornblende share specific gravities with apatite, possibly contaminating the apatite concentrate with Fe, Si, Ca, Al, Mg, Ti, and K. Such impurities could complicate downstream processing, particularly for phosphate fertilizer or phosphoric acid production. Therefore, a process that involves comminution to less than 212 μm, followed by magnetic separation to recover Fe-Ti oxides","PeriodicalId":100993,"journal":{"name":"Ore and Energy Resource Geology","volume":"19 ","pages":"Article 100120"},"PeriodicalIF":0.0,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145519210","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 : 2025-10-01DOI: 10.1016/j.oreoa.2025.100119
Kamal Abou Elmagd , Ryo Matsumoto , Mohamed Abioui , Muhammad Hazem
The present study aims to investigate the paleoenvironmental conditions and relative sea-level change during the middle Miocene evaporite deposition at the Ras Banas Peninsula, Red Sea Coast, Egypt. The tectono-sedimentological evolution of the evaporite suite may provide a geological relationship with the surrounding structures of the peninsula. To address this objective, the study examines the petrology and sulfur isotope geochemistry of the middle Miocene sulfate evaporites (approximately 100 meters in thickness) of the Abu Dabbab Formation at the Ras Banas Peninsula, located along the Red Sea continental margin. The Abu Dabbab Formation can be subdivided into three distinct sedimentary facies, from base to top: (1) lower supratidal gypsiferous claystone, (2) middle lagoonal sandy and clayey gypsum, and (3) upper subaqueous marine laminated gypsum. Petrographic analysis reveals the presence of both primary and secondary evaporite facies, with the mineralogical composition dominated by gypsum, alongside minor amounts of anhydrite and dolomite. Geochemical data indicate that the average sulfur isotopic compositions (δ34S) for the lower, middle, and upper facies are 23.620/00, 23.300/00, and 23.83 0/00 VCDT, respectively. These findings suggest that the Abu Dabbab evaporites were deposited in a tectonically active basin that received inputs of meteoric water and fine clastics, influenced by seasonal shifts between arid and wet conditions. The occurrence of stratabound mineralization and isotopically light sulfur suggests that algal biological activity played a role in reducing sulfate to iron sulfide and native sulfur. The rapid lateral and vertical facies changes observed in this active continental margin are primarily attributed to tectonic processes and the associated paleoenvironmental dynamics.
{"title":"Petrography and sulfur isotope geochemistry of middle Miocene evaporites on the active continental margin, Ras Banas Peninsula, Red Sea coast, Egypt","authors":"Kamal Abou Elmagd , Ryo Matsumoto , Mohamed Abioui , Muhammad Hazem","doi":"10.1016/j.oreoa.2025.100119","DOIUrl":"10.1016/j.oreoa.2025.100119","url":null,"abstract":"<div><div>The present study aims to investigate the paleoenvironmental conditions and relative sea-level change during the middle Miocene evaporite deposition at the Ras Banas Peninsula, Red Sea Coast, Egypt. The tectono-sedimentological evolution of the evaporite suite may provide a geological relationship with the surrounding structures of the peninsula. To address this objective, the study examines the petrology and sulfur isotope geochemistry of the middle Miocene sulfate evaporites (approximately 100 meters in thickness) of the Abu Dabbab Formation at the Ras Banas Peninsula, located along the Red Sea continental margin. The Abu Dabbab Formation can be subdivided into three distinct sedimentary facies, from base to top: (1) lower supratidal gypsiferous claystone, (2) middle lagoonal sandy and clayey gypsum, and (3) upper subaqueous marine laminated gypsum. Petrographic analysis reveals the presence of both primary and secondary evaporite facies, with the mineralogical composition dominated by gypsum, alongside minor amounts of anhydrite and dolomite. Geochemical data indicate that the average sulfur isotopic compositions (δ<sup>34</sup>S) for the lower, middle, and upper facies are 23.62<sup>0</sup>/<sub>00</sub>, 23.30<sup>0</sup>/<sub>00</sub>, and 23.83 <sup>0</sup>/<sub>00</sub> VCDT, respectively. These findings suggest that the Abu Dabbab evaporites were deposited in a tectonically active basin that received inputs of meteoric water and fine clastics, influenced by seasonal shifts between arid and wet conditions. The occurrence of stratabound mineralization and isotopically light sulfur suggests that algal biological activity played a role in reducing sulfate to iron sulfide and native sulfur. The rapid lateral and vertical facies changes observed in this active continental margin are primarily attributed to tectonic processes and the associated paleoenvironmental dynamics.</div></div>","PeriodicalId":100993,"journal":{"name":"Ore and Energy Resource Geology","volume":"19 ","pages":"Article 100119"},"PeriodicalIF":0.0,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145219202","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 : 2025-10-01DOI: 10.1016/j.oreoa.2025.100098
Tingting Fu , Hao Song , Bin Yang , Rui Liu
This study focuses on the mining area of vanadium-titanium magnetite in Panzhihua, China, and aims to comprehensively assess the enrichment and pollution levels of heavy metals (Cd, Ti, Cu, Zn, As, Pb, Hg, Co, Mn, Ni, V, and Cr) in the soil of the region. Soil samples were collected from the surface layer (0–5 cm depth) using a manual stainless steel soil sampler, and the samples were subjected to complete digestion to analyze the heavy metal content. The results revealed that the average concentration of heavy metals in the soil followed the order of Ti > Mn > V > Zn > Cr > Cu, among others. A quantitative assessment of heavy metal pollution was conducted using various indices, including enrichment factor (EF), contamination factor (CF), pollution load index (PLI), geoaccumulation index (Igeo), and degree of contamination (Cd) along with modified degree of contamination (mCd). The study found that Ti and Cd exhibited high pollution loads, while the Igeo values for Pb, As, Hg, Zn, and Cr indicated that their accumulation is primarily attributed to natural processes. Additionally, correlation analysis revealed potential relationships among heavy metals and their possible sources; for instance, the enrichment of Ti and V is associated with natural minerals, while Mn, Ni, and Cu may be linked to mining and smelting activities. This research not only provides detailed data on heavy metal pollution in the Panzhihua region but also offers significant insights for understanding environmental health and ecological risks in the area.
{"title":"Evaluation of heavy metal accumulation and pollution in soils from the vanadium–titanium magnetite mining region in Panzhihua, China","authors":"Tingting Fu , Hao Song , Bin Yang , Rui Liu","doi":"10.1016/j.oreoa.2025.100098","DOIUrl":"10.1016/j.oreoa.2025.100098","url":null,"abstract":"<div><div>This study focuses on the mining area of vanadium-titanium magnetite in Panzhihua, China, and aims to comprehensively assess the enrichment and pollution levels of heavy metals (Cd, Ti, Cu, Zn, As, Pb, Hg, Co, Mn, Ni, V, and Cr) in the soil of the region. Soil samples were collected from the surface layer (0–5 cm depth) using a manual stainless steel soil sampler, and the samples were subjected to complete digestion to analyze the heavy metal content. The results revealed that the average concentration of heavy metals in the soil followed the order of Ti > Mn > V > Zn > Cr > Cu, among others. A quantitative assessment of heavy metal pollution was conducted using various indices, including enrichment factor (EF), contamination factor (CF), pollution load index (PLI), geoaccumulation index<span> (Igeo), and degree of contamination (Cd) along with modified degree of contamination (mCd). The study found that Ti and Cd exhibited high pollution loads, while the Igeo values for Pb, As, Hg, Zn, and Cr indicated that their accumulation is primarily attributed to natural processes. Additionally, correlation analysis revealed potential relationships among heavy metals and their possible sources; for instance, the enrichment of Ti and V is associated with natural minerals, while Mn, Ni, and Cu may be linked to mining and smelting activities. This research not only provides detailed data on heavy metal pollution in the Panzhihua region but also offers significant insights for understanding environmental health and ecological risks in the area.</span></div></div>","PeriodicalId":100993,"journal":{"name":"Ore and Energy Resource Geology","volume":"19 ","pages":"Article 100098"},"PeriodicalIF":0.0,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145736834","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 : 2025-09-19DOI: 10.1016/j.oreoa.2025.100118
Timothy Amangdam Anemana , Ernest Pankah , Mohammed Moro Buri
This study explores the effectiveness of electrokinetic removal of heavy metals, such as Cd, Ti, Sb, and Pb from abandoned and active tailing soils among different soil fractions/phases. owing to the nature of the soil components in tailings, traditional methods may encounter various challenges that are ineffective. The aim of the study is to understand and address the distribution of heavy metals among tailing soil fractions (exchangeable, carbon, iron manganese oxide, organic/sulfide, and residual bound fractions) via electrokinetic remediation. The research was conducted in a 1215 cm3 electrochemical cell containing gold tailings via a continuous constant current of 1 A for five days. A platinum electrode served as the anode, and a titanium plate acted as the cathode. After five days, the remediation efficiency was assessed via aqua regia and sequential extraction methods. The findings showed lower metal removal efficiencies of the abandoned tailings (<5 %) than those of active tailing soil. This phenomenon could be attributed to the surface charge of the soil particles and the diffusion of metals into soil minerals resulting in the stabilization and occlusion of the the heavy metals into the nonavailable phases of the soil (organic/sulfide and residual bound fractions). In the speciation studies, Pb species were enriched mainly in the residual fraction. Antimony was also enriched in the residual, organic/sulfide bound, and Fe/Mn fractions. The Cd was associated with organic/sulfide and residual fractions, whereas Ti was enriched mainly in organic/sulphide fractions. The concentration of heavy metals in the active and abandoned tailing soils were comparable. The study concluded that electrokinetic remediation has the potential to remove harmful elements from abandoned and active tailings whiles providing insightful information on the physicochemical phenomena governing these processes.
{"title":"Electrokinetic removal of Cd, Ti, Pb, and Sb from abandoned and active artisanal gold tailings from Amansie West District of Ghana","authors":"Timothy Amangdam Anemana , Ernest Pankah , Mohammed Moro Buri","doi":"10.1016/j.oreoa.2025.100118","DOIUrl":"10.1016/j.oreoa.2025.100118","url":null,"abstract":"<div><div>This study explores the effectiveness of electrokinetic removal of heavy metals, such as Cd, Ti, Sb, and Pb from abandoned and active tailing soils among different soil fractions/phases. owing to the nature of the soil components in tailings, traditional methods may encounter various challenges that are ineffective. The aim of the study is to understand and address the distribution of heavy metals among tailing soil fractions (exchangeable, carbon, iron manganese oxide, organic/sulfide, and residual bound fractions) via electrokinetic remediation. The research was conducted in a 1215 cm<sup>3</sup> electrochemical cell containing gold tailings via a continuous constant current of 1 A for five days. A platinum electrode served as the anode, and a titanium plate acted as the cathode. After five days, the remediation efficiency was assessed via aqua regia and sequential extraction methods. The findings showed lower metal removal efficiencies of the abandoned tailings (<5 %) than those of active tailing soil. This phenomenon could be attributed to the surface charge of the soil particles and the diffusion of metals into soil minerals resulting in the stabilization and occlusion of the the heavy metals into the nonavailable phases of the soil (organic/sulfide and residual bound fractions). In the speciation studies, Pb species were enriched mainly in the residual fraction. Antimony was also enriched in the residual, organic/sulfide bound, and Fe/Mn fractions. The Cd was associated with organic/sulfide and residual fractions, whereas Ti was enriched mainly in organic/sulphide fractions. The concentration of heavy metals in the active and abandoned tailing soils were comparable. The study concluded that electrokinetic remediation has the potential to remove harmful elements from abandoned and active tailings whiles providing insightful information on the physicochemical phenomena governing these processes.</div></div>","PeriodicalId":100993,"journal":{"name":"Ore and Energy Resource Geology","volume":"19 ","pages":"Article 100118"},"PeriodicalIF":0.0,"publicationDate":"2025-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145157117","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 : 2025-09-13DOI: 10.1016/j.oreoa.2025.100117
Edris Muhammed Pirot , Ayad Nuri Faqi Edilbi , Mahdi Mohammed Pirot Mamash , Bzhar Abdulmanaf Delizy , Sardar Mhyadin Balaky , Nabaz Abdulmajed Muhammad Salih , Hossein Khojasteh
Fourier Transform Infrared Spectroscopy (FTIR) and trace metal analysis were conducted on the set of 20 solid bitumen samples obtained from two geological formations; upper Campanian – lower Maastrichtian Bekhme Formation and Maastrichtian Aqra Formation. This study analyzes the infrared (IR) spectra of extracted asphaltene samples of both studied formations from two regions in northern Iraq (Bekhme region and Sare Sada region), focusing on key functional groups and molecular vibrations. The spectra reveal consistent peaks for alcohols (OH stretching), alkyl groups (CH₂ and CH₃ bending), and unsaturated bonds (alkenes and alkynes) across all studied samples. Additional peaks indicate the presence of CO stretching (suggesting alcohols and ethers) and metal-carbon stretching, pointing to metal coordination. The analysis highlights the complex structure of asphaltenes, which combine aliphatic chains, aromatic components, and trace metals. Peak intensities reflect slight similarities in composition. The stretching phenomenon can be attributed to the stretching vibration of hydroxyl groups. Comparing the aromatic, aliphatic, and long chains, together with the nickle to vanadium ratio, indicates that the examined samples originated from the same source of organic matter. Furthermore, it is highly probable that all samples from both studied regions originated from a mixed marine-terrestrial-oxic-dysoxic carbonate environment.
{"title":"Geochemical characteristics of Upper Cretaceous asphaltenes from bitumen seeps in the Kurdistan region, northern Iraq: Insights from trace metals and Fourier Transform Infrared (FTIR) spectroscopy","authors":"Edris Muhammed Pirot , Ayad Nuri Faqi Edilbi , Mahdi Mohammed Pirot Mamash , Bzhar Abdulmanaf Delizy , Sardar Mhyadin Balaky , Nabaz Abdulmajed Muhammad Salih , Hossein Khojasteh","doi":"10.1016/j.oreoa.2025.100117","DOIUrl":"10.1016/j.oreoa.2025.100117","url":null,"abstract":"<div><div>Fourier Transform Infrared Spectroscopy (FTIR) and trace metal analysis were conducted on the set of 20 solid bitumen samples obtained from two geological formations; upper Campanian – lower Maastrichtian Bekhme Formation and Maastrichtian Aqra Formation. This study analyzes the infrared (IR) spectra of extracted asphaltene samples of both studied formations from two regions in northern Iraq (Bekhme region and Sare Sada region), focusing on key functional groups and molecular vibrations. The spectra reveal consistent peaks for alcohols (O<img>H stretching), alkyl groups (CH₂ and CH₃ bending), and unsaturated bonds (alkenes and alkynes) across all studied samples. Additional peaks indicate the presence of C<img>O stretching (suggesting alcohols and ethers) and metal-carbon stretching, pointing to metal coordination. The analysis highlights the complex structure of asphaltenes, which combine aliphatic chains, aromatic components, and trace metals. Peak intensities reflect slight similarities in composition. The stretching phenomenon can be attributed to the stretching vibration of hydroxyl groups. Comparing the aromatic, aliphatic, and long chains, together with the nickle to vanadium ratio, indicates that the examined samples originated from the same source of organic matter. Furthermore, it is highly probable that all samples from both studied regions originated from a mixed marine-terrestrial-oxic-dysoxic carbonate environment.</div></div>","PeriodicalId":100993,"journal":{"name":"Ore and Energy Resource Geology","volume":"19 ","pages":"Article 100117"},"PeriodicalIF":0.0,"publicationDate":"2025-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145094914","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 : 2025-09-02DOI: 10.1016/j.oreoa.2025.100116
Kaitlyn A. Suarez , Michael L. Williams , Gregory J. Walsh , Daniel E. Harlov , Michael J. Jercinovic , Daniel J. Tjapkes , Ian W. Hillenbrand
The Adirondack Mountains of New York, U.S.A. contain iron oxide-apatite (IOA) mineral deposits with variable concentrations of rare earth elements (REE). The IOA mineral deposits are typically hosted in the Lyon Mountain Granite Gneiss and are spatially correlated with extensive Na metasomatism (albitization) of the surrounding country rocks, although some mineral deposits also occur in metagabbro, paragneiss, and anorthosite hosts. The location of albitization zones is key to finding new IOA mineral deposits and better understanding the mineralization processes associated with their genesis. However, the Na alteration zones are generally not visibly identifiable in outcrop or hand specimens because the color and textural changes are subtle and are thus difficult to map. Here, we discuss the results from testing two spectroscopic techniques (handheld, field gamma-ray spectroscopy, and portable X-ray fluorescence (pXRF)) to characterize albitization zones surrounding IOA mineral deposits.
The gamma-ray and pXRF spectrometers successfully distinguished the relative intensity of alteration in the Lyon Mountain Granite Gneiss based on the K abundance. The measured K content decreases towards the IOA mineral deposits, and the magnitude and width of the gradient are similar along the strike of each mineral deposit. Elevated Th and U values are present in host rocks adjacent to REE-bearing IOA mineral deposits. The pXRF and gamma-ray spectrometer K values are remarkably consistent with laboratory-based, whole-rock XRF compositional data and, therefore, useful for semi-quantitative analysis. Notably, albitization aureoles are consistent around REE-rich and REE-poor mineral deposits, suggesting that saline fluids are essential for the petrogenesis of IOA mineral deposits but may not be critical to REE mineralization. Ultimately, this study demonstrates the utility of handheld gamma-ray and pXRF spectrometry for identifying otherwise cryptic albitization gradients associated with IOA mineral deposits in granitic gneiss.
{"title":"Alteration mapping in granitic gneiss using handheld geophysical and geochemical instruments: Implications for iron oxide-apatite and rare earth elements exploration","authors":"Kaitlyn A. Suarez , Michael L. Williams , Gregory J. Walsh , Daniel E. Harlov , Michael J. Jercinovic , Daniel J. Tjapkes , Ian W. Hillenbrand","doi":"10.1016/j.oreoa.2025.100116","DOIUrl":"10.1016/j.oreoa.2025.100116","url":null,"abstract":"<div><div>The Adirondack Mountains of New York, U.S.A. contain iron oxide-apatite (IOA) mineral deposits with variable concentrations of rare earth elements (REE). The IOA mineral deposits are typically hosted in the Lyon Mountain Granite Gneiss and are spatially correlated with extensive Na metasomatism (albitization) of the surrounding country rocks, although some mineral deposits also occur in metagabbro, paragneiss, and anorthosite hosts. The location of albitization zones is key to finding new IOA mineral deposits and better understanding the mineralization processes associated with their genesis. However, the Na alteration zones are generally not visibly identifiable in outcrop or hand specimens because the color and textural changes are subtle and are thus difficult to map. Here, we discuss the results from testing two spectroscopic techniques (handheld, field gamma-ray spectroscopy, and portable X-ray fluorescence (pXRF)) to characterize albitization zones surrounding IOA mineral deposits.</div><div>The gamma-ray and pXRF spectrometers successfully distinguished the relative intensity of alteration in the Lyon Mountain Granite Gneiss based on the K abundance. The measured K content decreases towards the IOA mineral deposits, and the magnitude and width of the gradient are similar along the strike of each mineral deposit. Elevated Th and U values are present in host rocks adjacent to REE-bearing IOA mineral deposits. The pXRF and gamma-ray spectrometer K values are remarkably consistent with laboratory-based, whole-rock XRF compositional data and, therefore, useful for semi-quantitative analysis. Notably, albitization aureoles are consistent around REE-rich and REE-poor mineral deposits, suggesting that saline fluids are essential for the petrogenesis of IOA mineral deposits but may not be critical to REE mineralization. Ultimately, this study demonstrates the utility of handheld gamma-ray and pXRF spectrometry for identifying otherwise cryptic albitization gradients associated with IOA mineral deposits in granitic gneiss.</div></div>","PeriodicalId":100993,"journal":{"name":"Ore and Energy Resource Geology","volume":"19 ","pages":"Article 100116"},"PeriodicalIF":0.0,"publicationDate":"2025-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145048728","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 : 2025-08-31DOI: 10.1016/j.oreoa.2025.100115
Aamir Khan , Mohammad Tahir Shah , Liaqat Ali , Shah Fahad Alam , Ihtisham Islam , Salman Ahmed Khattak
This study evaluates the quality of nephrite by investigating its gemological, mineralogical and geochemical properties. Petrographic analysis revealed that the nephrite is primarily composed of tremolite, with minor amounts of actinolite, while the host rock, serpentinite, is predominantly composed of chrysotile and antigorite, with traces of tremolite, diopside, zoisite, talc, and plagioclase. Geochemically, the major oxides such as SiO2, MgO, CaO and Fe2O3 are ranging from 54.69 to 59.1 wt. %, 20.18 to 21.89 wt. %, 10.24 to 13.98 wt. % and 2.09 to 3.01 wt. %, respectively. The trace elements, including cobalt (Co), chromium (Cr) and nickel (Ni) are ranging from 6 to 31 ppm, 401 to 1005 ppm and 789 to 987 ppm, respectively. The Fe2+/(Mg2+ + Fe2+) ratios for the bulk rock range from 0.10 to 0.14. Gemologically, the nephrite exhibits a color range from light-green to green, a refractive index from 1.61 to 1.62, specific gravity from 2.97 to 3.04, a hardness from 5.8 to 6.2, and Schmidt hammer values from 38.00 to 39.60 MPa. These properties are consistent with typical nephrite characteristics. The intensity of light to dark green color is controlled by variations in the contents of Fe, Cr and Ni. Additionally, the Fe2+/(Mg2+ + Fe2+) ratio, along with high contents of Ni and Cr, and field observations suggest that the nephrite is of serpentinite-related origin, having undergone hydrothermal metasomatic transformation through elemental exchange between the silica-rich intrusions and host ultramafic rocks. The findings of this study contribute valuable insights into the geological processes of nephrite formation, which may aid in the exploration and research of nephrite deposits in other regions.
{"title":"Mineralogy and geochemistry of nephrite from Drosh area, district Chitral, northern Pakistan","authors":"Aamir Khan , Mohammad Tahir Shah , Liaqat Ali , Shah Fahad Alam , Ihtisham Islam , Salman Ahmed Khattak","doi":"10.1016/j.oreoa.2025.100115","DOIUrl":"10.1016/j.oreoa.2025.100115","url":null,"abstract":"<div><div>This study evaluates the quality of nephrite by investigating its gemological, mineralogical and geochemical properties. Petrographic analysis revealed that the nephrite is primarily composed of tremolite, with minor amounts of actinolite, while the host rock, serpentinite, is predominantly composed of chrysotile and antigorite, with traces of tremolite, diopside, zoisite, talc, and plagioclase. Geochemically, the major oxides such as SiO<sub>2</sub>, MgO, CaO and Fe<sub>2</sub>O<sub>3</sub> are ranging from 54.69 to 59.1 wt. %, 20.18 to 21.89 wt. %, 10.24 to 13.98 wt. % and 2.09 to 3.01 wt. %, respectively. The trace elements, including cobalt (Co), chromium (Cr) and nickel (Ni) are ranging from 6 to 31 ppm, 401 to 1005 ppm and 789 to 987 ppm, respectively. The Fe<sup>2+</sup>/(Mg<sup>2+</sup> + Fe<sup>2+</sup>) ratios for the bulk rock range from 0.10 to 0.14. Gemologically, the nephrite exhibits a color range from light-green to green, a refractive index from 1.61 to 1.62, specific gravity from 2.97 to 3.04, a hardness from 5.8 to 6.2, and Schmidt hammer values from 38.00 to 39.60 MPa. These properties are consistent with typical nephrite characteristics. The intensity of light to dark green color is controlled by variations in the contents of Fe, Cr and Ni. Additionally, the Fe<sup>2+</sup>/(Mg<sup>2+</sup> + Fe<sup>2+</sup>) ratio, along with high contents of Ni and Cr, and field observations suggest that the nephrite is of serpentinite-related origin, having undergone hydrothermal metasomatic transformation through elemental exchange between the silica-rich intrusions and host ultramafic rocks. The findings of this study contribute valuable insights into the geological processes of nephrite formation, which may aid in the exploration and research of nephrite deposits in other regions.</div></div>","PeriodicalId":100993,"journal":{"name":"Ore and Energy Resource Geology","volume":"19 ","pages":"Article 100115"},"PeriodicalIF":0.0,"publicationDate":"2025-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144932121","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 : 2025-08-21DOI: 10.1016/j.oreoa.2025.100114
Ervin Veress , Oskar Rydman , Rayhan A. Farrenzo , Joel B.H. Andersson , Mathis Warlo , Irvine R. Annesley , Tobias E. Bauer
Discoveries of deposits at shallow depths are becoming scarce, leading exploration efforts to increasingly focus on deeper targets. Traditional exploration techniques for subsurface mapping are often ineffective in terrains obscured by vegetation and glacial sediments, prompting the development of new methods, particularly those centered on geophysics. While geophysical surveys can be valuable for peering beneath the surface cover, reducing initial exploration costs, they are often insufficient to resolve the three-dimensional architecture in structurally complex settings. Integrating geological and geophysical studies ensures that geological characteristics of rock units and structural frameworks are considered, leading to geologically validated results. Merging geological and geophysical models demands a strong understanding of how physical properties are distributed and influenced by geological factors. Our study aims to enhance the understanding of geological factors controlling petrophysical properties in the Kiruna Mining District (Sweden). We conducted an integrated analysis of geochemistry, mineralogy, texture, and petrophysical properties from 35 outcrop locations, including 105 density, magnetic susceptibility, and P-wave velocity measurements from the Kiruna area. The results reveal not only distinct contrasts between lithological units but also significant intraformational variability driven by alteration and fabric, which can obscure lithological boundaries in geophysical surveys. Structural processes such as crustal shortening and basin inversion were found to impose a strong control on the petrophysical properties, contributing to complex and diagnostic signatures. The geological-petrophysical framework presented in this study serves as a foundation for integrated studies in northern Sweden, enabling geophysical methods to serve as a tool for understanding mineral system components and test conceptual models.
{"title":"Linking mineralogical, geochemical, and textural controls to petrophysical signatures in the Kiruna Mining District, Sweden","authors":"Ervin Veress , Oskar Rydman , Rayhan A. Farrenzo , Joel B.H. Andersson , Mathis Warlo , Irvine R. Annesley , Tobias E. Bauer","doi":"10.1016/j.oreoa.2025.100114","DOIUrl":"10.1016/j.oreoa.2025.100114","url":null,"abstract":"<div><div>Discoveries of deposits at shallow depths are becoming scarce, leading exploration efforts to increasingly focus on deeper targets. Traditional exploration techniques for subsurface mapping are often ineffective in terrains obscured by vegetation and glacial sediments, prompting the development of new methods, particularly those centered on geophysics. While geophysical surveys can be valuable for peering beneath the surface cover, reducing initial exploration costs, they are often insufficient to resolve the three-dimensional architecture in structurally complex settings. Integrating geological and geophysical studies ensures that geological characteristics of rock units and structural frameworks are considered, leading to geologically validated results. Merging geological and geophysical models demands a strong understanding of how physical properties are distributed and influenced by geological factors. Our study aims to enhance the understanding of geological factors controlling petrophysical properties in the Kiruna Mining District (Sweden). We conducted an integrated analysis of geochemistry, mineralogy, texture, and petrophysical properties from 35 outcrop locations, including 105 density, magnetic susceptibility, and P-wave velocity measurements from the Kiruna area. The results reveal not only distinct contrasts between lithological units but also significant intraformational variability driven by alteration and fabric, which can obscure lithological boundaries in geophysical surveys. Structural processes such as crustal shortening and basin inversion were found to impose a strong control on the petrophysical properties, contributing to complex and diagnostic signatures. The geological-petrophysical framework presented in this study serves as a foundation for integrated studies in northern Sweden, enabling geophysical methods to serve as a tool for understanding mineral system components and test conceptual models.</div></div>","PeriodicalId":100993,"journal":{"name":"Ore and Energy Resource Geology","volume":"19 ","pages":"Article 100114"},"PeriodicalIF":0.0,"publicationDate":"2025-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145048727","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 : 2025-08-20DOI: 10.1016/j.oreoa.2025.100113
Agostinho Mussa, Wolfgang Kalkreuth, Ana Maria Pimentel Mizusaki, Marleny Blanco González, Tais Freitas da Silva
The Paleozoic-Mesozoic Parnaiba Basin is an intraplate volcano-sedimentary basin which the Pimenteiras Formation (Devonian) has the higher potential for hydrocarbon generation, mainly gas and condensate. The present study aims to make a petrographic characterization of organic matter and solid bitumen from the Pimenteiras Formation (Devonian), Parnaíba Basin (Brazil), potential for hydrocarbon generation. The study observed the presence of solid bitumen, formed as a result of the cracking of terrestrial organic matter (gas-prone) and marine organic matter (oil-prone) during diagenesis and catagenesis. These solid bitumens were classified according to the reflectance values such as glance pitch, grahamite and epi-impsonite. The solid bitumens were observed in all analyzed wells with a significance variation in terms of thermal maturity from top to bottom of the Pimenteiras sequence. High reflectance values (epi-impsonite) were observed in samples located at the bottom of the sequence in relation to the top samples, mainly in the BP-77 well. On the other hand, significance variations in terms of vitrinite reflectance values were not observed in samples close to igneous intrusions. Greater presence of macerals such as vitrinite and inertinite was identified, and rarely were observed liptinites. Large particles of solid bitumens were observed, being mostly biostructured and characterized by a homogeneous gray surface, mostly well preserved and isotropic. Similar biostructuring was also observed in palynofacies data, through the phytocasts. The solid bitumen reflectance ranges from 0.46 to 1.16 %Ro in the BP-77 well samples, with vitrinite reflectance equivalent (VREo) ranging from 0.68 to 1.12 %Ro, from 0.33 to 0.50 %Ro (with VREo varying from 0.60 to 0.71 %Ro) in the BP-59 well samples, and between 0.36 and 0.7 %Ro with VREo varying between 0.62 and 0.84 %Ro in the BP-22 well samples, respectively. These data suggest that the organic matter ranges from early to late mature in terms of thermal maturity. On the other hand, the solid bitumen versus vitrinite reflectance, and solid bitumen versus Tmax suggest that the OM (organic matter) varies from immature to early mature. The presence of solid bitumens suggests a thermal maturity of the organic matter and potential for hydrocarbon generation.
{"title":"Petrographic characterization of organic matter and solid bitumen from the Pimenteiras Formation (Devonian), Parnaíba Basin (Brazil), potential for hydrocarbon generation","authors":"Agostinho Mussa, Wolfgang Kalkreuth, Ana Maria Pimentel Mizusaki, Marleny Blanco González, Tais Freitas da Silva","doi":"10.1016/j.oreoa.2025.100113","DOIUrl":"10.1016/j.oreoa.2025.100113","url":null,"abstract":"<div><div>The Paleozoic-Mesozoic Parnaiba Basin is an intraplate volcano-sedimentary basin which the Pimenteiras Formation (Devonian) has the higher potential for hydrocarbon generation, mainly gas and condensate. The present study aims to make a petrographic characterization of organic matter and solid bitumen from the Pimenteiras Formation (Devonian), Parnaíba Basin (Brazil), potential for hydrocarbon generation. The study observed the presence of solid bitumen, formed as a result of the cracking of terrestrial organic matter (gas-prone) and marine organic matter (oil-prone) during diagenesis and catagenesis. These solid bitumens were classified according to the reflectance values such as glance pitch, grahamite and epi-impsonite. The solid bitumens were observed in all analyzed wells with a significance variation in terms of thermal maturity from top to bottom of the Pimenteiras sequence. High reflectance values (epi-impsonite) were observed in samples located at the bottom of the sequence in relation to the top samples, mainly in the BP-77 well. On the other hand, significance variations in terms of vitrinite reflectance values were not observed in samples close to igneous intrusions. Greater presence of macerals such as vitrinite and inertinite was identified, and rarely were observed liptinites. Large particles of solid bitumens were observed, being mostly biostructured and characterized by a homogeneous gray surface, mostly well preserved and isotropic. Similar biostructuring was also observed in palynofacies data, through the phytocasts. The solid bitumen reflectance ranges from 0.46 to 1.16 %R<sub>o</sub> in the BP-77 well samples, with vitrinite reflectance equivalent (VRE<sub>o</sub>) ranging from 0.68 to 1.12 %R<sub>o</sub>, from 0.33 to 0.50 %R<sub>o</sub> (with VRE<sub>o</sub> varying from 0.60 to 0.71 %R<sub>o</sub>) in the BP-59 well samples, and between 0.36 and 0.7 %R<sub>o</sub> with VRE<sub>o</sub> varying between 0.62 and 0.84 %R<sub>o</sub> in the BP-22 well samples, respectively. These data suggest that the organic matter ranges from early to late mature in terms of thermal maturity. On the other hand, the solid bitumen versus vitrinite reflectance, and solid bitumen versus T<sub>max</sub> suggest that the OM (organic matter) varies from immature to early mature. The presence of solid bitumens suggests a thermal maturity of the organic matter and potential for hydrocarbon generation.</div></div>","PeriodicalId":100993,"journal":{"name":"Ore and Energy Resource Geology","volume":"19 ","pages":"Article 100113"},"PeriodicalIF":0.0,"publicationDate":"2025-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144907416","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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