Ore Geology Reviews最新文献

{"title":"Reinterpretation of the geodynamic evolution and multistage mineralization events of the Nifty copper deposit, Paterson Province, Western Australia through age, textural and geochemical data","authors":"Urmidola Raye ,&nbsp;Paul Polito ,&nbsp;Peir K. Pufahl ,&nbsp;Justin Drummond ,&nbsp;Ross Campbell ,&nbsp;Robert A. Creaser ,&nbsp;Laure Martin ,&nbsp;Bruno V. Ribeiro ,&nbsp;Christopher L. Kirkland ,&nbsp;Marina Joury ,&nbsp;Julie Ruzicka","doi":"10.1016/j.oregeorev.2025.106801","DOIUrl":"10.1016/j.oregeorev.2025.106801","url":null,"abstract":"<div><div>The structurally-controlled Nifty copper deposit in Western Australia is more complex than previously recognised. The earliest sulfide mineralisation represented by pre-ore, framboidal and atoll/sunflower-shaped pyrite is overgrown and replaced by Stage 1 sphalerite, galena, pyrite and chalcopyrite that has characteristics of Clastic-Dominated type Zn-Pb mineralisation. Stage 2 mineralisation is represented by stratiform and disseminated chalcopyrite associated with phengite-chlorite ± dolomite assemblages. Stage 2 mineralisation formed at 278 ± 25 °C before being silicified then cross-cut by Stage 3, structurally controlled, massive, vein and breccia chalcopyrite, pyrite, quartz, dolomite, siderite, and other minor minerals, which formed between 271 ± 44 °C and 295 ± 15 °C.</div><div>Historic geochronological data combined with new observations reveal that Stage 1 mineralisation formed between 840 Ma and 810 Ma whereas Stage 2 mineralisation may have formed as early as 717 ± 5 Ma. New Re-Os ages of 673.9 ± 3.3 Ma and 664.8 ± 1.7 Ma from Stage 3 pyrite correspond to previously reported U-Pb ages of 675 ± 21 Ma, 665 ± 9 Ma and 648 ± 12 Ma obtained from monazite and apatite extracted from quartz-chalcopyrite veinlets, and overlap with a U–Pb age of 678 ± 12 Ma from titanite in a biotite monzogranite, and the earliest stages of the intrusion of the O’Callaghans Supersuite intrusions. A Rb-Sr age of 619 ± 14 Ma from biotite in a chalcopyrite-quartz vein represents the last stage of copper mineralisation.</div><div>Whole rock geochemical data and LA-ICPMS analysis support petrographic findings and is used to distinguish the different stages of mineralisation. Importantly, Stage 3 mineralisation records highly anomalous concentrations of both U and Sn, indicating that copper mineralisation involved mixing of an oxidised and a reduced fluid during the mineralisation processes. The ilmenite-stable granites of the O’Callaghans Supersuite are a possible source for Sn at Nifty, but more work is required to substantiate this hypothesis.</div></div>","PeriodicalId":19644,"journal":{"name":"Ore Geology Reviews","volume":"185 ","pages":"Article 106801"},"PeriodicalIF":3.2,"publicationDate":"2025-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144703644","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Genesis and metallogenic setting of the Banchang Cu–Mo deposit, Central China: Evidence from geochemistry and Sr–Nd–Hf isotopes","authors":"Zhaoyi Li ,&nbsp;Guiqing Xie ,&nbsp;Yuce Zhang ,&nbsp;Gang Chen ,&nbsp;Junzeng Zuo ,&nbsp;Yu Zhang ,&nbsp;Xiaolong Li ,&nbsp;Xiaofei Zhang","doi":"10.1016/j.oregeorev.2025.106781","DOIUrl":"10.1016/j.oregeorev.2025.106781","url":null,"abstract":"<div><div>The Banchang Cu–Mo deposit, located in the East Qinling Orogenic Belt of Central China, serves as a significant example of distal skarn mineralization. Two magmatic events are documented in the deposit: (1) early Paleozoic (442–425 Ma) granite porphyry, and (2) late Mesozoic (147–146 Ma) mineralized biotite monzogranite porphyry and granite porphyry. This study integrates detailed geochemical analyses, Sr–Nd–Hf isotopic data, and apatite U–Pb geochronology to investigate the magmatic genesis, metallogenic processes, and tectonic setting of mineralization. Whole-rock geochemical data indicate that the late Mesozoic magmas exhibit high-K calc-alkaline to shoshonitic affinities and range from metaluminous to weakly peraluminous, with elevated Sr/Y ratios (70.74) and weak negative Eu anomalies (Eu/Eu* = 0.75). The magmas exhibit Sr–Nd–Hf isotopic compositions [(⁸⁷Sr/⁸⁶Sr)_i = 0.70387–0.70682; εNd(t) =  − 9.96 to − 6.02; εHf(t) =  − 5.4 to − 1.5] indicative of derivation from hybridized crust–mantle sources. These geochemical signatures were generated by partial melting of thickened lower lithospheric crust coupled with asthenospheric upwelling during late Jurassic to early Cretaceous intracontinental extension. Both the late Mesozoic biotite monzogranite porphyry and granite porphyry exhibit high oxygen fugacity (ΔFMQ = +0.8), moderate to high water contents (6–10.6 wt% H₂O), and Cl-rich compositions (0.11–0.29 wt%). These characteristics collectively demonstrate significant copper transport capacity and mineralization potential in both rock types.</div><div>A comparative analysis of Mo deposits in the southern margin of the North China Block, Cu–Mo deposits in North Qinling Block and the Southern Qinling Block reveals that Cu-forming magmas exhibit a higher proportion of mantle-derived components and elevated Cl contents. Magma source heterogeneity is a primary control on Cu–Mo metallogenic differentiation in the East Qinling Orogenic Belt.</div></div>","PeriodicalId":19644,"journal":{"name":"Ore Geology Reviews","volume":"185 ","pages":"Article 106781"},"PeriodicalIF":3.2,"publicationDate":"2025-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144703645","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Thermochronological insights into the Mesozoic-Cenozoic exhumation history of the Southern Tianshan orogen","authors":"Li Yang ,&nbsp;Jing Yang ,&nbsp;Bin Zhang ,&nbsp;Zhenju Zhou","doi":"10.1016/j.oregeorev.2025.106785","DOIUrl":"10.1016/j.oregeorev.2025.106785","url":null,"abstract":"<div><div>The mechanisms governing rapid exhumation and uplift of the Tianshan orogenic belt, particularly during the Late Jurassic–Early Cretaceous and Late Eocene, remain incompletely understood.</div><div>In this study, We integrate new apatite (U–Th)/He thermochronological data from 11 samples in the southern Tianshan to reconstruct thermal histories and elucidate the timing, rates, and driving mechanisms of cooling across multiple tectonic stages. The results reveal three major phases of rapid cooling: the Early Cretaceous (140–120 Ma), the Late Cretaceous to Paleocene (80–60 Ma), and the Cenozoic (primarily 40–30 Ma and 25–10 Ma). Early Cretaceous exhumation was predominantly controlled by tectonic activity related to the India–Eurasia plate collision, with exhumation rates exceeding 0.2 mm/yr in certain high-altitude sectors of the western Tianshan. In contrast, Late Cretaceous to Paleocene exhumation is interpreted to reflect localized tectonic stress accumulation and episodic release, rather than extensive regional deformation. Cenozoic exhumation evhibits marked spatial heterogeneity, with pronounced variability in both magnitude and timing across the Tianshan orogen, reflecting differential influences of the India–Eurasia plate collision, the Pamir Plateau indentation, and ongoing tectonic deformation within the Tarim Basin. The western and central Tianshan experienced more intense and sustained exhumation, whereas the eastern Tianshan was characterized by weaker and more spatially restricted exhumation. These regional differences are interpreted to result from variations lithospheric structure, the distribution of tectonic stress, and superimposed climatic factors such as the progressive aridification of inland Asia.</div></div>","PeriodicalId":19644,"journal":{"name":"Ore Geology Reviews","volume":"185 ","pages":"Article 106785"},"PeriodicalIF":3.2,"publicationDate":"2025-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144694588","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Zircon U–Pb dating and Sr–Nd–Pb–Hf isotopic constraints on the petrogenesis of adakitic granite in the Nansu complex, Jiaodong Peninsula","authors":"Naijie Chi ,&nbsp;Zhaopeng Wang ,&nbsp;Songjie Wang ,&nbsp;Chuan’e Liu ,&nbsp;Huali Gao ,&nbsp;Sen Li ,&nbsp;Wei Shan ,&nbsp;Yuanhui Xie ,&nbsp;Zengsheng Li ,&nbsp;Ying Shen ,&nbsp;Yuqin Sun ,&nbsp;Min Li ,&nbsp;Xiufeng Wang","doi":"10.1016/j.oregeorev.2025.106765","DOIUrl":"10.1016/j.oregeorev.2025.106765","url":null,"abstract":"<div><div>Early Cretaceous granitic rocks are widely distributed in the Jiaodong Peninsula of eastern China, but their origin and petrogenesis are still controversial. The results of zircon U–Pb and Lu–Hf isotopes and whole-rock elemental and Sr–Nd–Pb isotope geochemistry on a suite of granite from the Nansu complex in northwestern Jiaodong Peninsula are presented here. The granites are weakly peraluminous and show high-K calc-alkaline features with high K₂O/Na₂O ratios of 0.86–1.98 and low FeO^t/(FeO^t + MgO) of 0.67–0.78, similar to typical I-type granite. These rocks are adakitic with high Sr (up to 779 ppm), low Y (4.28–12.70 ppm) and Yb (0.48–1.32 ppm) and generally high Sr/Y (mostly &gt; 40) and La/Yb (26.8–81.9) ratios. They are enriched in light rare earth elements (LREE) and depleted in heavy rare earth elements (HREE) with weakly to moderate negative Eu anomalies, and they show enriched in large ion lithophile elements relative to high field strength elements. Isotopically, the Nansu granites show variably enriched Sr (initial ⁸⁷Sr/⁸⁶Sr = 0.7081–0.7108), Nd [ε_Nd(<em>t</em>) = –20.8 to –9.7] and Pb [(²⁰⁶Pb/²⁰⁴Pb)_i = 16.84–17.99; (²⁰⁷Pb/²⁰⁴Pb)_i = 15.42–15.52; (²⁰⁸Pb/²⁰⁴Pb)_i = 37.39–37.90] isotope compositions that range between the continental crust and enriched subcontinental lithospheric mantle (SCLM) of the North China Craton (NCC). U–Pb dating on newly grown magmatic zircon yields consistent ages of 120 ± 1 to 117 ± 1 Ma, demonstrating that the Nansu granite was emplaced during the early Cretaceous. The magmatic zircon also has variable εHf(<em>t</em>) values of –24.5 to –17.7 and Archean to Paleoproterozoic two-stage Hf model ages of 2735 ± 39 to 2291 ± 41 Ma. In consideration of all these geochemical data and the geological context of the NCC during the late Mesozoic, we propose that the adakitic granite in the Nansu complex was formed by variable degrees of mixing/mingling of an enriched SCLM-derived basaltic magma and a continental crust-derived felsic magma at normal crustal depths. Rollback of the subducted paleo-Pacific slab and the accompanied upwelling of the asthenospheric mantle are considered as the major geodynamic mechanism to cause melting of the overlying SCLM, and then underplating of the basaltic magma provided the required heat for partial melting of the continental crust.</div></div>","PeriodicalId":19644,"journal":{"name":"Ore Geology Reviews","volume":"185 ","pages":"Article 106765"},"PeriodicalIF":3.6,"publicationDate":"2025-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144722055","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A robust soft voting ensemble of the isolation forest model, extended isolation forest model and generalized isolation forest model for multivariate geochemical anomaly recognition","authors":"Chenyi Zheng ,&nbsp;Yongliang Chen ,&nbsp;Xudong Du","doi":"10.1016/j.oregeorev.2025.106787","DOIUrl":"10.1016/j.oregeorev.2025.106787","url":null,"abstract":"<div><div>Rapid and effective recognition of metallogenic anomalies from geochemical exploration data is the key to quickly locate potential mineral prospecting areas. Isolation forest (IF) algorithm, extended isolation forest (EIF) algorithm and generalized isolation forest (GIF) algorithm are three advanced unsupervised learning ensemble techniques that can isolate anomalies rapidly and effectively from high-dimensional data. Previous studies have shown that the three unsupervised learning ensembles have high performance and high efficiency in the recognition of multivariate geochemical anomalies. However, they suffer from lack of robustness because of the randomness in isolation tree construction, including random subsampling with replacement and random selection of splitting threshold, which causes unstable anomaly patterns in complex geochemical settings. To solve this problem, a robust soft voting ensemble (SVE) model was built from the IF model, EIF model and GIF model for the recognition of multivariate geochemical anomalies in the Molidawa area (Inner Mongolia, China). The IF model, EIF model and GIF model were built on the interpolated 1:50,000 stream sediment data and used as the base anomaly recognition models. The soft voting algorithm was then used to build the SVE model based on the three base anomaly recognition models. A comparison of the SVE model with the three base anomaly recognition models shows that the SVE model is more robust than the three base anomaly recognition models. The anomalies recognized by the SVE model contain all the known molybdenum deposits and spatially coincide with the molybdenum mineralization controlling factors such as intermediate-acidic magmatic intrusions and faults. Therefore, in geochemical anomaly recognition, soft voting algorithm is a feasible tool to build a robust anomaly recognition ensemble model from a set of base anomaly recognition models lacking robustness.</div></div>","PeriodicalId":19644,"journal":{"name":"Ore Geology Reviews","volume":"185 ","pages":"Article 106787"},"PeriodicalIF":3.2,"publicationDate":"2025-07-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144655936","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Lithological control on the distribution of ores in W-Mo porphyry systems: An example from the Ochtiná-Rochovce deposit (Western Carpathians, Slovakia)","authors":"Peter Koděra ,&nbsp;Diego Delgado Yáñez ,&nbsp;Jana Brčeková ,&nbsp;Rastislav Vojtko ,&nbsp;Juraj Majzlan ,&nbsp;Pavel Uher ,&nbsp;Ondrej Nemec ,&nbsp;František Bakos","doi":"10.1016/j.oregeorev.2025.106786","DOIUrl":"10.1016/j.oregeorev.2025.106786","url":null,"abstract":"<div><div>In W-Mo porphyry deposits, tungsten and molybdenum ore bodies are often spatially separated due to the decoupling of W and Mo during hydrothermal processes and fluid-rock reactions. The Ochtiná-Rochovce W-Mo deposit has variable host lithologies affected by hydrothermal alteration mostly in well-defined vein selvedges. The Ochtiná-Rochovce W-Mo deposit was studied in detail by geochemical and mineralogical analytical methods on samples derived from a recent exploration campaign. Biotitic phyllite and mafic metavolcanites in upper parts of the deposit are the main W host, with abundant scheelite, accompanied by minor wolframite. Deeper metasandstone is enriched in molybdenite. Mineralisation is hosted by quartz stockworks and veins, and developed during biotite-wolframite, scheelite-molybdenite-pyrite and K-feldspar-calcite stages. Tungsten minerals precipitated by an increase in pH aided by wall-rock reactions and loss of CO₂ from early fluids on decompression. Amphibole and plagioclase replacement by biotite in vein selvedges in metavolcanites provided Fe, Ca, and Mg for precipitation of W minerals. The trend of increasing Mg/(Mg + Fe), F and decreasing Ti in biotite in all rocks suggest its hydrothermal origin. The Mg-rich wolframite preferentially occurring in metavolcanites documents a high <em>a</em>Mg in the early fluids related to biotite alteration. Molybdenite deposition was promoted by cooling of later fluids, related to decompression, combined with decreasing <em>f</em>O₂ and increase in pH, resulting in quartz-sericite ± pyrite selvedges. Scheelite precipitation and replacement of wolframite are related to a progressive decrease in <em>a</em>Fe/<em>a</em>Ca following the biotite crystallisation, accompanied by increase in <em>f</em>S₂ associated with the saturation with respect to molybdenite. Progress of fluid-rock reactions and cooling invoked a further drop of acidity and <em>f</em>O₂, enrichment in S(−II), and liberation of Fe(II) into the fluid, thereby generating abundant pyrite. The presented model, that links the nature of lithologies to ore precipitation processes, can aid in a more efficient exploration for this type of mineralisation worldwide.</div></div>","PeriodicalId":19644,"journal":{"name":"Ore Geology Reviews","volume":"185 ","pages":"Article 106786"},"PeriodicalIF":3.2,"publicationDate":"2025-07-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144663086","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 depth of boiling in the epithermal environment: Comparison of different pressure regimes and implications to the design of fluid inclusion microthermometric studies","authors":"Thomas Monecke ,&nbsp;Jochen Monecke ,&nbsp;T. James Reynolds ,&nbsp;Tawn Albinson","doi":"10.1016/j.oregeorev.2025.106774","DOIUrl":"10.1016/j.oregeorev.2025.106774","url":null,"abstract":"<div><div>Boiling of hydrothermal liquids is an important process of ore formation in epithermal vein deposits formed within hundreds of meters below the paleowater table. This contribution provides boiling profiles for hydrothermal liquids in the H₂O–NaCl model system between surface conditions and their respective critical points for several different pressure regimes. It is shown that assumptions made on the prevailing pressure regime decisively influence the pressure–depth relationship, which has implications to the interpretation of fluid inclusion data obtained from epithermal deposits. The results of this study demonstrate that paleodepth reconstructions are best conducted by recording the highest homogenization temperature encountered on liquid-rich fluid inclusion assemblages in a number of samples collected from different elevations within a given deposit or exploration project and enveloping the obtained temperature data with the hot hydrostatic boiling-point-to-depth profile for an aqueous solution of appropriate salinity. This contrasts with the practice of conducting microthermometric investigations on fluid inclusion assemblages that record boiling, or performing statistical analysis on large numbers of unconstrained microthermometric measurements.</div></div>","PeriodicalId":19644,"journal":{"name":"Ore Geology Reviews","volume":"185 ","pages":"Article 106774"},"PeriodicalIF":3.2,"publicationDate":"2025-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144663089","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Constraints of groundwater and hydrothermal activity on formation of zeolites in alkaline basalts (Gedaref, eastern Sudan)","authors":"T.A. Suliman ,&nbsp;Hanlie Hong ,&nbsp;M.A. Hassan ,&nbsp;Li Yong ,&nbsp;Chen Liu ,&nbsp;Adamu Yunusa ,&nbsp;Atif Salim ,&nbsp;Thomas J. Algeo","doi":"10.1016/j.oregeorev.2025.106784","DOIUrl":"10.1016/j.oregeorev.2025.106784","url":null,"abstract":"<div><div>Zeolites are widely employed as indicators of synformational chemical and geothermal gradients in various geological environments. The presence of zeolites in the Gedaref alkaline basalts of eastern Sudan was investigated using optical microscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), electron probe microanalysis (EPMA), and Raman spectroscopic techniques. Our results show that the Gedaref alkaline basalts experienced low-grade regional metamorphism, resulting in two distinct zeolite assemblages linked to warm groundwater (Stage I) and hydrothermal activity (Stage II). In Stage I, finely crystalline zeolites and associated minerals formed by hydrolysis of olivine, clinopyroxene and plagioclase and filling in primary pore space. This stage is marked by formation of low-temperature zeolite facies minerals in vesicles in the paragenetic sequence of fine zeolites: thomsonite, mesolite, chabazite, natrolite, analcime, which was preceded by the formation of phyllosilicates (nontronite/chlorite) and scalenohedral calcite, which is consistent with fluid evolution toward higher Si/Al ratios. In Stage II, a second generation of larger (up to 4 cm in size), euhedral zeolite crystals formed in the paragenetic sequence of stilbite, chabazite, levyne, thomsonite, mesolite, natrolite, and analcime. After zeolite formation, a late stage of precipitation of rhombohedral calcite, quartz geodes, and semi-gemstone (agate) occurred. This mineral assemblage suggests variation in fluid Ca²⁺ and (CO₃)^2- concentrations due to carbonate leaching. Stage I zeolitization was driven by interaction of heated groundwater with the host rocks within a pH range of 7.6 to 8.7, whereas Stage II zeolitization was mainly influenced by dissolution of carbonate rocks underlying the volcanic study units. The evolution of fluid chemical compositions took place in a system of progressively increasing temperatures (from 60-350 °C) according to the paragenetic history of zeolite formation.</div></div>","PeriodicalId":19644,"journal":{"name":"Ore Geology Reviews","volume":"185 ","pages":"Article 106784"},"PeriodicalIF":3.2,"publicationDate":"2025-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144655938","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A semi-supervised approach for mineral prospectivity mapping via weighted positive-unlabeled learning and tree-structured parzen estimator for hyperparameter optimization","authors":"Mahsa Hajihosseinlou ,&nbsp;Abbas Maghsoudi ,&nbsp;Reza Ghezelbash","doi":"10.1016/j.oregeorev.2025.106783","DOIUrl":"10.1016/j.oregeorev.2025.106783","url":null,"abstract":"<div><div>Mineral prospectivity mapping (MPM) has been approached through supervised, unsupervised, and semi-supervised learning methods. Supervised models often yield high accuracy but require both positive and negative labels, which are rarely available in mineral exploration. Unsupervised methods avoid the need for labels but typically lack geological interpretability and cannot integrate known mineral occurrences. Semi-supervised techniques, particularly Positive Unlabeled (PU) learning, offer a balanced alternative by reducing dependence on negative labels. Beyond addressing label scarcity, PU learning enhances generalization, mitigates labeling bias, and utilizes known mineral information more effectively. In this study, Weighted PU learning was employed. Unlike earlier PU strategies that treated all unlabeled data uniformly, this method assigns differentiated weights to positive and unlabeled instances, reducing class imbalance and improving model robustness. Since Weighted PU learning requires a classifier, we selected Gaussian Naive Bayes (GNB) due to its probabilistic nature and ability to handle uncertainty in mineral prospectivity modeling. Additionally, the parameters of Weighted PU learning were optimized using the Tree-structured Parzen Estimator (TPE) to achieve the best performance. The method was applied to Mississippi Valley-Type (MVT) Pb-Zn mineralization in the Malayer-Esfahan metallogenic belt, Iran. A conceptual deposit model guided the selection and extraction of relevant exploration layers, which were then integrated into the modeling workflow. Comparative evaluation against Semi Supervised Random Forest learning demonstrated the superior predictive performance of the Weighted PU model. These findings highlight the practical effectiveness of the Weighted PU approach in real-world mineral prospectivity mapping.</div></div>","PeriodicalId":19644,"journal":{"name":"Ore Geology Reviews","volume":"185 ","pages":"Article 106783"},"PeriodicalIF":3.2,"publicationDate":"2025-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144685518","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Formation mechanism of the Yangchang Cu-Mo vein-type deposit, Inner Mongolia, NE China: Constraints from fluid inclusions and O-H-S-Pb isotopes","authors":"Yicun Wang ,&nbsp;Dadi Cao ,&nbsp;Siwen Fan ,&nbsp;Bei Xu ,&nbsp;Mingchun Song ,&nbsp;Jie Li ,&nbsp;Junhao Zhang ,&nbsp;Jingfu Wu ,&nbsp;XueBing Zhang ,&nbsp;Shunda Li","doi":"10.1016/j.oregeorev.2025.106777","DOIUrl":"10.1016/j.oregeorev.2025.106777","url":null,"abstract":"<div><div>The Yangchang deposit, located in the central Xilamulun Metallogenic Cu-Mo Polymetallic Belt in NE China, is a typical vein-type Cu-Mo deposit. The orebodies, hosted in silicified and sericitized Cretaceous monzogranite, are controlled by a NE-trending fault. Although vein-type deposits represent an important in the Xilamulun Cu-Mo system, questions remain regarding their genetic relationship to regional magmatism, similarity to porphyry deposits, and the presence of a concealed magma chamber. This study investigates the pressure–temperature conditions, sources, and evolution of ore-forming fluids in the Yangchang deposit. Based on orebody crosscutting relationships, three paragenetic stages were identified: (1) Stage I: pyrite–quartz; (2) Stage II: pyrite–chalcopyrite–molybdenite–quartz; and (3) Stage III: sphalerite–galena–quartz. Primary fluid inclusions (FIs) were classified into three types: pure CO₂ (PC-type), CO₂-NaCl-H₂O (C-type), and NaCl-H₂O (L-type). Homogenization temperatures ranged from 360 to 310 °C (Stage I), 333–208 °C (Stage II), and 233–152 °C (Stage III), with salinities consistently below ∼ 12 wt% NaCl_equiv Trapping pressures during Stage I were 1,000–1,250 bar, corresponding to a depth of approximately 2.10 km (km). The O-H isotope analyses indicated an evolving fluid source, with δD values ranging from (−14.4 to –116.6 ‰) and δ¹⁸O_water values 3.88 to 14.82 ‰, reflecting a transition from magmatic to meteoric water. Sulfur (δ³⁴S_V-CDT = 0.4–1.2 ‰) and lead isotopic data suggest a magmatic origin of metals with additional crustal input. These findings indicate that the Yangchang vein-type Cu-Mo deposit is genetically associated with regional magmatism formed during the Early Cretaceous Paleo-Pacific tectonic regime.</div></div>","PeriodicalId":19644,"journal":{"name":"Ore Geology Reviews","volume":"185 ","pages":"Article 106777"},"PeriodicalIF":3.2,"publicationDate":"2025-07-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144633865","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}