Ore and Energy Resource Geology最新文献

{"title":"A comprehensive review of advanced polymer gel technologies in enhanced oil recovery and water production control","authors":"Amir Javad Borhani,&nbsp;Fatemeh Ghazi,&nbsp;Ali Akbari,&nbsp;Ali Ranjbar,&nbsp;Yousef Kazemzadeh","doi":"10.1016/j.oreoa.2025.100109","DOIUrl":"10.1016/j.oreoa.2025.100109","url":null,"abstract":"<div><div>Excessive water production is a major challenge in the petroleum industry, significantly reducing oil recovery efficiency and increasing operational costs by approximately $50 billion annually. Enhanced Oil Recovery (EOR) methods, such as thermal and non-thermal techniques, aim to improve oil production by altering reservoir and fluid properties. Thermal methods, including steam injection and electromagnetic heating (EMH), have shown oil production increases ranging from 11 % to 500 %, despite high initial costs and operational complexities. Non-thermal methods, such as polymer, surfactant, and alkaline injections, target light to medium viscosity oils, achieving oil recovery improvements between 5 % to 45 %. Chemical methods, particularly polymer gels, have gained prominence for their efficacy in controlling excessive water production and enhancing oil recovery. Polyacrylamide gels, known for their profile control capabilities, can increase oil recovery by 10–30 %. Recent advancements in microgels and nanogels offer better stability and compatibility with harsh reservoir conditions, such as high salinity and temperatures, resulting in recovery improvements up to 35 %. Field studies demonstrate the USA and Canada leading in EOR adoption, with polymer injection projects constituting over 80 % of chemical EOR applications. To further advance oil recovery and address excessive water production, continued research into optimizing polymer gel formulations and exploring new chemical EOR methods is essential. Tailoring EOR techniques to specific reservoir conditions, including temperature, salinity, and rock permeability, will enhance their effectiveness. The integration of nanoparticles into polymer gels shows promise for improving structural strength and performance, highlighting the need for innovative approaches in the petroleum industry.</div></div>","PeriodicalId":100993,"journal":{"name":"Ore and Energy Resource Geology","volume":"19 ","pages":"Article 100109"},"PeriodicalIF":0.0,"publicationDate":"2025-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144738660","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}

{"title":"Structure and mineralization in the Lebowa granite suite: Insights from high-resolution 2D reflection seismic method","authors":"Bibi Ayesha Jogee,&nbsp;Musa S.D. Manzi,&nbsp;Nombuso G. Maduna,&nbsp;Bojan Brodic,&nbsp;Moyagabo K. Rapetsoa,&nbsp;Ian James,&nbsp;Mpofana Sihoyiya,&nbsp;Glen T. Nwaila,&nbsp;Paul A.M. Nex,&nbsp;Leonidas Vonopartis","doi":"10.1016/j.oreoa.2025.100108","DOIUrl":"10.1016/j.oreoa.2025.100108","url":null,"abstract":"<div><div>Rare Earth Elements (REEs) are critical metals that occur in various geological systems including granitic systems. The Lebowa Granite Suite (LGS) of the Bushveld Complex (South Africa) is known as an A-type granitic suite and hosts polymetallic mineralization including tin, fluorine and REE mineralization. High-resolution reflection seismic surveys were conducted to understand the structural architecture and mineralization within the farm boundaries of Blokspruit and Ruigtepoort in the LGS in the North West Province. Two-dimensional (2D) reflection seismic results show that the LGS is approximately 5 km thick in the western portion of the Bushveld Complex and is intruded by dolerite sills of the Umkondo large igneous province. The REE mineralization is structurally controlled and hosted within actinolite intrusive bodies. REE mineralization is associated with NW-SE and NE-SW trending faults, which acted as conduits for ore-forming fluids. In seismic sections, fault zones are delineated as highly attenuated seismic signatures that crosscut strong amplitude seismic horizons. Near the highly attenuated zones are high amplitude reflector packages (HARPs), which correspond to the actinolite intrusive bodies. We demonstrate the value of using the reflection seismic method as an effective and efficient exploration strategy to explore for geological structures that control REEs mineralization, and its potential to become a core component for mineral exploration in hard rock environments.</div></div>","PeriodicalId":100993,"journal":{"name":"Ore and Energy Resource Geology","volume":"19 ","pages":"Article 100108"},"PeriodicalIF":0.0,"publicationDate":"2025-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144738658","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}

{"title":"Geochemical characteristics of surface samples in the Mkuju River uranium project, southern Tanzania: implications for uranium geochemical exploration and provenance studies","authors":"Athanas S. Macheyeki ,&nbsp;Dalaly P. Kafumu","doi":"10.1016/j.oreoa.2025.100107","DOIUrl":"10.1016/j.oreoa.2025.100107","url":null,"abstract":"<div><div>Uranium occurrences in Tanzania are mainly associated with Karoo Formations, including the Namtumbo-Mkuju River and Madaba deposits. Additional occurrences are found in Quaternary-Holocene playa lake deposits in the Manyoni and Bahi areas (Central Tanzania), Galapo and Minjingu (Arusha region) and within magmatic and carbonatite systems at Chimala and Pandahill (Southwestern Tanzania). This study focuses on the Mkuju River uranium deposits in southern Tanzania to characterize elemental distributions, identify geochemical trends and determine uranium provenance. A total of 64 auger samples were collected from depths of 0–3 m at 1 km × 1 km grid intervals. Samples were analyzed using ICP-AES and ICP-MS following aqua regia digestion at SGS Laboratories (South Africa), with duplicates analyzed via XRF at the Geological Survey of Tanzania. Correlation coefficients (R) between uranium and other elements range from -0.07 (Ti) to 0.79 (Zn). Stronger correlations (<em>R</em> &gt; 0.47) were observed between uranium and lithophile elements, or those with mixed lithophile-siderophile or chalcophile-siderophile behavior, indicating multiple uranium sources. Element thresholds varied with depth. Uranium, Sn and Sb showed increasing thresholds, whereas Hf, P, Ca, Zr, Co, Al, Ti, Rb, Sr, Na, Tl, Th, Mn and Cr decreased. Uranium concentrations exceeding 4.65 ppm are considered anomalous. Downhole threshold variability was element-specific. For example, W showed 0 % variability, Mo (siderophile / chalcophile) 12 %, and Cu, Ga, Sn (chalcophile / lithophile) ranged from 10 to 29 %. HFSE lithophiles like Hf and Ta varied by 12–25 %, while chalcophiles such as Zn, Pb, In, As, Tb, Bi, Ag and Cd ranged from 4 to 26 %. Siderophile / chalcophile elements like Co, Fe, Sb and Ni exhibited 6–29 % variability. Lithophiles (e.g., U, V, K, Al, Ce, Mg) varied by 5–40 %. Mn, a siderophile, had the highest variability at 43 %. Geochemical data suggest uranium anomalies in the Namtumbo area originate mainly from greywackes, arkosic sandstones, black shales and partially from weathered igneous granites. This implies a multi-source origin involving sedimentary input, hydrothermal diagenesis and hydrothermal magmatic-volcanic activity. Therefore, uranium in this basin likely formed through (1) syn-sedimentary processes, (2) diagenetic alteration, and (3) magmatic-hydrothermal systems. However, the absence of Eh and pH data limits insight into element mobility. These findings provide new insights into downhole element threshold variability and uranium provenance, offering valuable guidance for exploration geoscientists. The approach may be applied to similar geological contexts for improved sampling strategies and anomaly detection.</div></div>","PeriodicalId":100993,"journal":{"name":"Ore and Energy Resource Geology","volume":"19 ","pages":"Article 100107"},"PeriodicalIF":0.0,"publicationDate":"2025-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144270841","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}

{"title":"Remote mapping of lineaments and hydrothermal alteration zones related to unconformity-related uranium deposits in the Badami Group of the western Kaladgi basin, India","authors":"R. Kalimuthu ,&nbsp;Alok Porwal ,&nbsp;Hari Shankar Pandalai","doi":"10.1016/j.oreoa.2025.100106","DOIUrl":"10.1016/j.oreoa.2025.100106","url":null,"abstract":"&lt;div&gt;&lt;div&gt;In mineral exploration, identifying geophysical, geochemical and mineralogical indicators is crucial and many techniques have been employed to discover the occurrence of mineralization and the associated host rock alterations. In the case of unconformity-related uranium deposits that are spatially-linked to major faults and unconformities between basement rocks and overlying basinal rocks, extensive alteration zones produced by hydrothermal fluid-rock interactions which are used to target mineralization and are therefore vital tools for uranium exploration. The synoptic capability of remote sensing enables precise geological mapping by delineating structural features (faults, folds, shear zones), lithology and mineralogy, addressing field investigation constraints. The present study uses digital elevation model and satellite-borne multispectral data to map major lineaments and hydrothermal alteration zones associated with unconformity-related uranium deposits in the Badami Group of the western Kaladgi basin, India. Geologically, the study area comprises relatively undeformed arenites and conglomerates of the Neoproterozoic Badami Group that unconformably overlie an Archean basement (Peninsular gneiss). A few unconformity-related uranium prospects hosted by the Badami conglomerates and basal arenite have been identified by the Atomic Minerals Directorate in the study area. Conjunctive analysis of SRTM DEM and ASTER VNIR-SWIR data were used to map structures and lithological units. Band ratios, colour composite, least square fitting, principal component analysis and spectral angle mapper methods were further applied to ASTER VNIR-SWIR data to map the hydrothermal alteration zones. Follow-up ground checks were carried out to validate the results of the remote sensing analysis and interpretation. The results reveal that NE-SW and E-W trending lineaments are the major structural features and argillic (kaolinite) and phyllic (illite) are the dominant alteration types present in the study area. There is a strong intercorrelation between lineaments and hydrothermal alteration zones. Field surveys and laboratory analysis including petrographic studies and XRD analysis confirmed the occurrences of such alteration zones. The spatial association of hydrothermal alteration zones with structures indicates that these major lineaments and unconformable contact between the basement and the basinal sandstone could have provided major pathways for uranium-rich fluids and zones of low redox potential may have facilitated uranium precipitation. Several potential exploration targets were demarcated based on the juxtaposition of alteration zones, unconformity surface, major lineaments and cross-cutting structures. The identified targets correlate well with known uranium mineralization. This investigation demonstrates that integrating STRM with ASTER data is a valuable tool that can improve the efficiency of uranium exploration. This study narrows down the are","PeriodicalId":100993,"journal":{"name":"Ore and Energy Resource Geology","volume":"19 ","pages":"Article 100106"},"PeriodicalIF":0.0,"publicationDate":"2025-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144204265","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}

{"title":"Geochemical characteristics of stream sediments as a preliminary tool for exploration in the Mbengwi area, Northwestern Cameroon","authors":"Ralain Bryan Ngatcha ,&nbsp;Ngambu Aloysius Afahnwie ,&nbsp;Mary Ewokolo Molua Etutu ,&nbsp;Fuofu Hanson Fombalang ,&nbsp;Oliver Anoh Njoh","doi":"10.1016/j.oreoa.2025.100104","DOIUrl":"10.1016/j.oreoa.2025.100104","url":null,"abstract":"<div><div>The Mbengwi area is located along the Cenozoic volcano-plutonic Cameroon Volcanic Line (CVL) within the Northern Domain of the Pan-African Neoproterozoic Fold Belt of Cameroon. Important magnetite filings are continuously recovered in the area along drainage trails. The source of this concealed mineralization has not been established. A total of ten active stream sediment samples were recovered and analyzed for major and trace elements by the inductively coupled plasma mass spectrometry (ICP-MS) technique. The mineralogical population (phases) of the heavy mineral concentrates consists of zircon, rutile, quartz, and opaque mineral phases, with angular to sub-rounded morphologies indicating moderate to long transport distances. Sediment geochemistry shows high contents in Fe₂O₃ up to 37.43 wt.%, with low contents in Al₂O₃, MgO, CaO, Na₂O, and K₂O. The concentrations of siderophiles (e.g., Fe, Bi, Co, Cr, Ga, Mn, Mo, and Ni) and chalcophiles (e.g., In, Sn, and Hg) are slightly elevated with respect to their average upper continental crust values. The spatial distribution of iron and other elements is presented as point symbol maps, and the data is analyzed using multivariate statistics. From the principal component analysis (PCA), the Ag-Hg-Tl-Mo-As-Sb-Cd-Se-Pb-Au-In-Nb, as well as the Zn-Co-Ga-Mn-Ni-In-Fe-Cu factors, point to the presence of a hydrothermal fluid circulation in the area associated with possible Au-Ag-Mo and Fe-Cu mineralization. Ag, Hg, Mo, and As could serve as a pathfinder for Au in the area. The single element factor with Sn reflects the occurrence of cassiterite host rocks in the area. The sediments from the Mbengwi area were deposited under humid tropical and equatorial climates. The geochemical parameters (CIA, CIW, and PIA) point to a strong weathering of feldspar-bearing source rocks. The dominant mafic to intermediate igneous provenance suggests that mica schists, granodiorites, monzogranites, monzonites, and basanites could be potential source rocks in the area.</div></div>","PeriodicalId":100993,"journal":{"name":"Ore and Energy Resource Geology","volume":"19 ","pages":"Article 100104"},"PeriodicalIF":0.0,"publicationDate":"2025-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143931521","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}

{"title":"Assessing CO2 sequestration potential in Cenozoic basaltic rocks of Harrat Al-Shaam, Jordan","authors":"Ahmed Hammam ,&nbsp;Ahmed Nagy ,&nbsp;Israa S. Abu-Mahfouz ,&nbsp;Ahmed Al-Yaseri","doi":"10.1016/j.oreoa.2025.100105","DOIUrl":"10.1016/j.oreoa.2025.100105","url":null,"abstract":"<div><div>Carbon geo-sequestration is a promising approach to mitigate greenhouse gas emissions, particularly through the long-term storage of CO₂ in suitable geological formations. This study investigates the potential of the Harrat Al-Shaam Volcanic Field (HSVF) in Jordan as a host site for CO₂ mineralization, focusing on its textural, mineralogical, and geochemical characteristics. Basaltic rocks, known for their chemical composition rich in calcium (Ca), iron (Fe), and magnesium (Mg), demonstrate a favorable capacity for CO₂ sequestration. They undergo chemical reactions with injected CO₂ and brine, leading to the formation of stable carbonate minerals. In this work, we conducted a series of laboratory experiments involving the injection of supercritical CO₂ mixed with brine and freshwater into basalt core and powder samples to evaluate their mineralization potential under controlled conditions. Parameters such as mineral composition, alteration, and porosity were assessed. Microscopic investigations and geochemical analyses revealed changes in textural and mineralogical composition after CO₂ treatment. Notably, rapid neutralization of carbonic acid during injection was observed, resulting in the formation of calcite through water-rock reactions, which underscores the swift mineralization process inherent to these basaltic formations. The study confirms the moderate potential for carbonate mineralization and CO₂ storage capacity within the basaltic rocks of HSVF, attributed to their alkaline composition, enrichment of Ca and Fe-bearing minerals, and structural features such as fractures that enhance porosity and permeability. These findings highlight the effectiveness of mafic rocks as reliable candidates for geological CO₂ storage and indicate a need for further research to fully explore their long-term sequestration capabilities.</div></div>","PeriodicalId":100993,"journal":{"name":"Ore and Energy Resource Geology","volume":"19 ","pages":"Article 100105"},"PeriodicalIF":0.0,"publicationDate":"2025-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144084669","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}

{"title":"Hydrogeochemical provenance and evolution in Ganhai Well’s groundwater, Eastern Tibetan Plateau","authors":"Guanchun Chen ,&nbsp;Liang Tang ,&nbsp;Long-Fei Gou ,&nbsp;Chuan Jiang ,&nbsp;Yang Xu","doi":"10.1016/j.oreoa.2025.100101","DOIUrl":"10.1016/j.oreoa.2025.100101","url":null,"abstract":"<div><div>The Ganhai Well (27.48° N, 101.46° E), an earthquake monitoring well since September 1980, is situated in the earthquake-prone of the eastern Tibetan Plateau, China. Despite years of monitoring, the hydrogeochemical origins and evolution of groundwater in the well remain unclear. Based on a weekly water sampling in 2022, the hydrochemical characteristics of the Ganhai Well were extrapolated. (1) The groundwater’s ions are derived from evaporite (45.2–48.0 %) and silicate rocks (36.4–40.9 %), followed by carbonate rocks (12.2–15.4 %), and negligible anthropogenic inputs (less than 1 %). In the Ganhai Well, calcite tends to precipitate and crystallise, whereas dolomite maintains equilibrium with the solution. (2) It is a significant observation that the groundwater within the Ganhai Well is deep-seated, confined soda water (HCO₃·Cl-Na type), characterised by minor temporal fluctuations in its ionic concentrations and high stability. This hydrogeochemical profile establishes it as an extremely valuable and sustainable water resource, offering considerable support for regional ecological preservation and economic development.</div></div>","PeriodicalId":100993,"journal":{"name":"Ore and Energy Resource Geology","volume":"19 ","pages":"Article 100101"},"PeriodicalIF":0.0,"publicationDate":"2025-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143941337","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}

{"title":"Optimising gold exploration in Northeast Sudan using analytical hierarchy process with multidisciplinary geodata","authors":"Abu Nasser Hussain,&nbsp;Biswajit Thander,&nbsp;Siddhartha Kumar Lahiri","doi":"10.1016/j.oreoa.2025.100103","DOIUrl":"10.1016/j.oreoa.2025.100103","url":null,"abstract":"<div><div>Orogenic gold deposits, responsible for about one-third of the world’s gold production, typically form in tectonically active zones, where shear zones, suture zones, and faults serve as pathways for hydrothermal fluids, promoting gold mineralisation. Sudan’s diverse geology, characterised by Pan-African terrains within the Arabian-Nubian Shield, is a globally significant gold province with a rich history of ancient and modern mining activities. Despite having a rich legacy of gold exploration, there is an absence of an optimised strategy that helps reduce the cost of exploration. This research aims to seek <em>how a geoscientific decision-making tool, the Analytical Hierarchy Process (AHP), optimises orogenic gold exploration by systematically weighing key geological and geophysical parameters in regions with complex tectonic histories</em>. By evaluating four key parameters, lineament density, mineral composite map, lithological classification and free air gravity anomalies, available through open-access geospatial data sources, and introducing an empirical Relative Gold Mineralised Index (RGMI), this study applies AHP to assign weights to these variables, reflecting their influence on gold mineralisation. This structured approach identifies high-potential gold zones in northeast Sudan and proposes a scalable methodology for strategic orogenic gold exploration in similar geological settings worldwide.</div></div>","PeriodicalId":100993,"journal":{"name":"Ore and Energy Resource Geology","volume":"19 ","pages":"Article 100103"},"PeriodicalIF":0.0,"publicationDate":"2025-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144068023","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}

{"title":"Magnetic anomaly investigation for mineral potential assessment in the Plateau-Bauchi basement complex, Northern Nigeria","authors":"Ema Abraham ,&nbsp;Moses Emetere","doi":"10.1016/j.oreoa.2025.100102","DOIUrl":"10.1016/j.oreoa.2025.100102","url":null,"abstract":"<div><div>The Plateau-Bauchi Basement Complex in northern Nigeria is a geologically diverse region with significant mineral potential. This study employs an integrated geophysical approach to map the structural framework and mineralization controls within this economically vital region. High-resolution aeromagnetic data were processed using a comprehensive suite of magnetic analysis techniques. The analytical toolkit included Source Parameter Imaging (SPI), Phase Symmetry (PS), Analytic Signal (AS), Tilt Derivative analysis, Butterworth bandpass filtering, 3D magnetic anomaly inversion, and Euler deconvolution. Our results reveal an intricate network of faults, fractures, and intrusive bodies that govern mineralization patterns across the study area. Prominent structural trends (NW-SE, NE-SW, E-W, and N-S) and estimated depths to magnetic sources ranging from near-surface (&lt;420 m) to deeper structures (up to 1330 m) have been delineated. Integration of the geophysical techniques allows for the delineation of high-susceptibility zones corresponding to potential mineral-rich deposits. Strong correlations between geophysical anomalies and known occurrences of economically important minerals, including tin, columbite, kaolin, niobium, and rare earth elements such as tourmaline are observed. Complex fault intersections and intrusive features, particularly in the Kakkek, Durbi, Durr, and Barkin Ladi regions, create favorable conditions for mineral accumulation. This study provides crucial insights into the subsurface architecture of the Plateau-Bauchi basement complex and its relationship to mineralization processes. Our findings establish a robust framework for guiding future exploration efforts and contribute significantly to the understanding of mineral deposit formation in complex geological terrains.</div></div>","PeriodicalId":100993,"journal":{"name":"Ore and Energy Resource Geology","volume":"19 ","pages":"Article 100102"},"PeriodicalIF":0.0,"publicationDate":"2025-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143924533","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}

{"title":"Late Archean Rare Metal (Nb-Ta-Li-Be) bearing Granitic Pegmatite (LCT) in Nagamangala Schist Belt, Dharwar Craton, India: Insights from Uraninite and Zircon mineral chemistry","authors":"Chanchal Sarbajna ,&nbsp;Sudhiranjan Swain ,&nbsp;V.R. Akhila ,&nbsp;K.L. Mundra ,&nbsp;Dheeraj Pande","doi":"10.1016/j.oreoa.2025.100100","DOIUrl":"10.1016/j.oreoa.2025.100100","url":null,"abstract":"&lt;div&gt;&lt;div&gt;The Late Archean rare metal (Nb-Ta-Li-Be) bearing granitic pegmatites of the Nagamangala Schist Belt, Dharwar Craton, India, represent an important geological setting for understanding the mineralogical and geochemical evolution of Lithium-Cesium-Tantalum (LCT) pegmatites. This study provides detailed insights into the mineral chemistry of uraninite and zircon, using Back Scattered Electron (BSE) imaging and quantitative Electron Probe Micro Analysis (EPMA), to characterize their composition, formation history, and evolutionary trends. Subsurface samples of pegmatites from the Marlagalla area reveal the presence of euhedral to anhedral Th-rich uraninite along with unusually high hafnium (Hf) content in the associated zircon-an aspect reported first time from these pegmatites. Uraninite grains are found partially or fully enclosed by phases such as garnet, microlite [(Ca,Na)&lt;sub&gt;2&lt;/sub&gt;Ta&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;6&lt;/sub&gt;(O,OH,F)], tapiolite [(Fe,Mn)(Ta,Nb)&lt;sub&gt;2&lt;/sub&gt;O], zircon and apatite in the studied samples. Uraninite grains exhibit significant compositional variations, with UO&lt;sub&gt;2&lt;/sub&gt; ranging from 64.74 to 70.92 wt %, high ThO&lt;sub&gt;2&lt;/sub&gt; concentrations (up to 10.85 wt %), and PbO content between 23.01 and 25.37 wt %. The rare earth element (REE) content is notably low (RE&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;3&lt;/sub&gt;: 0.15–0.89 wt %), and SiO&lt;sub&gt;2&lt;/sub&gt; is nearly absent (&lt;0.01 to 0.29 wt %). Chemical formula calculations indicate a U&lt;sup&gt;4+&lt;/sup&gt; range of 0.227–0.345 and U&lt;sup&gt;6+&lt;/sup&gt; between 0.301–0.340, suggesting significant auto-oxidation-a hallmark of ancient uraninites. Furthermore, EPMA-based U-Th-Pb chemical age dating of the uraninite suggests a minimum formation age of approximately 2335 ± 54 Ma, making it the oldest reported uraninite in pegmatite from Indian subcontinent.&lt;/div&gt;&lt;div&gt;The associated zircon grains display exceptionally high HfO&lt;sub&gt;2&lt;/sub&gt; content (9.94–20.49 %), coupled with ZrO&lt;sub&gt;2&lt;/sub&gt; (45.56–58.89 %) and SiO&lt;sub&gt;2&lt;/sub&gt; (27.59–30.56 %), categorizing them as hafnian zircons. Their elevated radioactive element content and close association with uranothorite, alongside the high Th content in uraninite, indicate progressive magmatic fractionation. This is further supported by geochemical trends such as the Zr/Hf vs. Hf in zircon and UO&lt;sub&gt;2&lt;/sub&gt;/ThO&lt;sub&gt;2&lt;/sub&gt; vs. ThO&lt;sub&gt;2&lt;/sub&gt; in uraninite. The U&lt;sup&gt;6+&lt;/sup&gt;/U&lt;sup&gt;4+&lt;/sup&gt; ratio close to unity suggests auto-oxidation as the dominant mechanism, reinforced by the high PbO content in these uraninites.&lt;/div&gt;&lt;div&gt;These findings provide crucial insights into the Late Archean Algoman orogeny, a global event marked by extensive granitic plutonism. The Marlagalla pegmatites share key mineralogical and geochemical similarities with other Algoman-related pegmatites, suggesting a possible genetic link. Furthermore, the evolved nature of these pegmatites, in relation to the adjacent Allapatna granite, underscores their complex magmatic history and potential economic significance","PeriodicalId":100993,"journal":{"name":"Ore and Energy Resource Geology","volume":"19 ","pages":"Article 100100"},"PeriodicalIF":0.0,"publicationDate":"2025-04-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143911569","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}