Search Results (238)

Countries participating in the Belt and Road Initiative (BRI) hold substantial mineral resources that support industrial supply chains and the energy transition. However, the geographic distribution and production concentration of these resources remain insufficiently quantified. This study examines ten minerals across a fixed BRI country scope: iron ore, copper, gold, nickel, cobalt, lithium, bauxite, potash, tin, and phosphate rock. Countries entered each mineral-specific sample only when they met the adopted BRI and metallogenic belt criteria and reported positive 2023 mine production. We calculated the Herfindahl–Hirschman Index (HHI) and concentration ratios (CR4 and CR8) from 2023 country-level data in the USGS Mineral Commodity Summaries 2025. The 2024 estimates were retained only for descriptive comparison. Nickel (HHI = 0.567; CR4 = 1.000), cobalt (HHI = 0.666; CR4 = 0.957), and lithium (HHI = 0.522; CR4 = 1.000) formed the strongest concentration profile. Iron ore, copper, gold, and potash showed lower relative concentration (HHI = 0.151–0.276; CR4 = 0.653–0.934). Bauxite, tin, and phosphate rock formed a residual monitoring group with intermediate to high concentration indicators. These interpretive groups organize the 2023 results and do not constitute universal supply risk categories. External evidence on policy, logistics, processing, and sustainability is used to interpret the profiles rather than being included in the concentration measures. Full article

Deep exploration in mature gold districts requires subsurface alteration evidence that can be related quantitatively to three-dimensional (3D) geological architecture. This study develops a workflow for the Tudui–Shawang deposit in the Muping–Rushan metallogenic belt that integrates drill-core short-wave infrared (SWIR) spectroscopy, 3D alteration modeling, ore-controlling geological constraints, positive–unlabeled (PU) learning, and ensemble prospectivity prediction. A total of 2140 spectra from 10 drillholes were processed to identify mineral assemblages, extract spectral scalars and feature-shape attributes, classify alteration facies, and construct continuous 3D alteration evidence. Discrete smooth interpolation and indicator kriging were used for continuous and categorical attributes, respectively, and CatBoost, LightGBM, XGBoost, and Random Forest were evaluated within a spatially separated PU-bagging design. Quantitative analyses show that individual SWIR attributes have weak deposit-scale relationships with Au grade. Nevertheless, local IC minima, relatively lower pos2200 values near several mineralized intervals, alteration-facies transitions, and a broader shift toward longer pos2250 wavelengths characterize relevant parts of the mineralized system. FUSE performed best under 1 km × 1 km spatial holdout validation, with an ROC AUC of 0.8900 and a PRAUC of 0.8926. Prediction-area analysis and the 3D probability volume delineated three ranked exploration targets (T1–T3). The results show that drill-core SWIR-derived 3D alteration evidence, when integrated with ore-controlling geology and spatially validated machine learning, provides a practical basis for target prioritization in mature gold districts. Full article

Amidst the intensification of strategic mineral exploration, the discovery of concealed and deep-seated deposits within covered areas and the peripheries of existing mines has become a critical challenge and a central focus of contemporary research. “Dongchuan-type” (DCT) copper deposits represent a key mineralization style within the SW Yangtze Block. However, significant exploration breakthroughs have stagnated over the past three decades. Consequently, advanced exploration prediction research is urgently required to guide deep-resource evaluation. Using the Shizishan copper deposit in the Yimen area as a representative case, this study applies the theory of “metallogenic geological body prediction” to construct a tripartite model encompassing “metallogenic geological bodies, metallogenic structures and structural planes, and metallogenic characteristic markers”. The Shizishan deposit is classified as a sedimentary-reformed type, characterized by multi-episodic mineralization involving initial sedimentary processes, non-magmatic hydrothermal activity, and subsequent structural-magmatic hydrothermal overprinting. Key metallogenic geological bodies include ore-bearing stratigraphic associations, basin-margin faults, NE-trending fold–fault systems, and deep-seated concealed intrusions. Metallogenic structural planes comprise primary ore-controlling surfaces, secondary fold-related structures, and potential deep-seated magmatic intrusive interfaces. Alteration patterns display a distinct vertical zonation: shallower levels show medium-to-low temperature hydrothermal processes (silicification, carbonatization, sericitization, and chloritization), whereas deeper portions reveal high-temperature magmatic–hydrothermal indicators, specifically skarnization and intense silicification. This study proposes that the integration of “stratigraphy + structures + concealed intrusions” should serve as the primary criterion for target screening in deep exploration. By integrating geophysical and geochemical datasets into this model, three promising exploration targets were delineated within the Yimen area. These findings provide a refined theoretical framework for large-scale prospecting of DCT. Full article

The variation features of metallic element grades can reflect the enrichment level of mineral deposits. Thus, quantitative characterization of the spatial patterns of metallogenic elements is fundamental to studying ore-forming processes and implementing mineral exploration. This study applies fractal theory and self-developed MATLAB computational scripts to process Cu grade datasets from 28 drillholes within the Pulang porphyry copper deposit, Yunnan Province. Both rescaled range (R/S) analysis and correlation integral methods were applied to clarify the spatial patterns of Cu grades in drill-cores. The calculated Hurst exponents ranged from 0.510 to 0.636, which demonstrated the persistent variation of Cu grades along the vertical direction of drillholes. This work further explored the correlation between Cu mineralization and fluctuations in correlation dimension (D_C), with D_C values spanning 0.011–2.873. Results indicate steep fractal gradient zones host high-grade copper ore bodies, and fractal dimension is a robust indicator to trace the migration of hydrothermal fluids. The Hurst exponents of Cu grade sequences correlate strongly with mineralization intensity, and ore-bearing veins extend continuously throughout all sampled drillholes. Accordingly, fractal gradients can be utilized to depict prospective zones for favorable mineralization in uncharted regions. This methodology may be applicable to other structurally controlled mineral deposits where similar fracture-controlled mineralization occurs, though further testing on different deposit types is needed. Full article

Magnetotelluric (MT) transfer functions are commonly estimated using statistical regression methods. Reliable MT-derived geoelectrical structures are essential for investigating deep geodynamic processes and metallogenic systems; however, noise contamination can distort impedance estimates and lead to misleading geological interpretations. In this study, we introduced an MM-estimator into MT data processing and evaluated its performance alongside M- and S-estimators using synthetic examples and an MT data survey from northeastern China. The results indicate that all three estimation methods can effectively suppress complex background noise and improve the stability and reliability of MT impedance estimation. The methods produced generally consistent apparent resistivity and phase responses, with MM-estimator yielding relatively the lowest root-mean-square (RMS) values. However, the deviations–uncertainty trade-off should be carefully evaluated in practical applications, particularly when processing long-period MT data with MM-estimator. Finally, we suggest combining any of the three robust estimation methods with the remote reference technique to help suppress noise in both predictor variables (magnetic-field data) and dependent variables (electric-field data). Full article

With the rapid development of the global new-energy industry, lithium, as a key strategic mineral resource, has faced increasingly prominent supply–demand contradictions. The Anning area in Central Yunnan serves as an important clay-type lithium resource base in China, and its mineralization prediction research holds significant theoretical value and practical implications. This study focuses on the lithium-rich claystone of the Daoshitou Formation in the Anning area of Central Yunnan. Based on an in-depth analysis of typical clay-type lithium mineralization characteristics, this research analyzes regional lithium metallogenic conditions, identifies key ore-controlling factors and prospecting indicators, comprehensively collects geological, geophysical, geochemical, and remote sensing data, and completes digital processing. By integrating multi-source geoscience data, a multi-source geoscience information spatial database was constructed. Using the Random Forest algorithm as the core method and comparing with machine learning models such as XGBoost and Support Vector Machine (SVM), a mineralization prediction model was established to achieve quantitative prediction of clay-type lithium mineralization probability. The specific research findings are as follows: (1) The metallogenic model and prospecting indicators of clay-type lithium deposits were clarified. The Anning area of Central Yunnan mainly develops sedimentary clay-type lithium deposits, and mineralization is jointly controlled by lithium-rich source material supply, chemical weathering under warm and humid paleoclimate conditions, and weak reductive sedimentary environments of coastal-swamp facies; (2) a multi-source geoscience information database was constructed, extracting 16 predictive variables and establishing a metallogenic prediction sample dataset; (3) the Random Forest model performed optimally with an AUC value of 0.84, accuracy of 88.3%, precision of 89.4%, recall of 87.2%, and F1 score of 0.88; (4) three metallogenic prospect areas were delineated. The results indicate that under the study area conditions and existing data, the Random Forest model demonstrates good applicability and stability. The research results provide important target areas for lithium mineral exploration and deployment in the Anning area of Central Yunnan, and offer methodological references for similar deposit prediction research. Full article

Regional multi-isotope mapping provides an effective means of investigating deep crustal composition and crustal reworking processes. The western margin of the Yangtze Craton has experienced multiple episodes of magmatism, crustal reworking, and mineralization since its formation, making it an ideal region for exploring the relationship between deep crustal evolution and metallogenic systems. In this study, Sr-Nd-Hf isotopic and whole-rock geochemical mapping was conducted based on compiled geochronological, geochemical, and isotopic datasets, integrated with deep geophysical data, to reconstruct the Precambrian crustal composition and reworking processes of the region. The results reveal significant crustal heterogeneity in the western margin of the Yangtze Craton. West of the Anninghe Fault Zone, rocks exhibit depleted Nd-Hf isotopic signatures (ε_Hf(t) = 0 to +17; ε_Nd(t) = 0 to +6), low I_Sr values (0.702–0.710), and high Nb/Ta (14–26) and Zr/Hf (36–46) ratios, indicating derivation from the remelting of juvenile mafic lower crust and providing direct evidence for Proterozoic underplating of mantle-derived magmas. In contrast, rocks east of the Anninghe Fault Zone show enriched Nd-Hf isotopic signatures (ε_Nd(t) = −9 to 0; ε_Hf(t) = −7.5 to 0), higher I_Sr values (0.711–0.726), and lower Nb/Ta and Zr/Hf ratios (8–13 and 21–35), suggesting remelting of ancient continental crust. Mineralization is closely associated with crustal architecture. IOCG deposits mainly occur in juvenile crustal domains, whereas Sn polymetallic and phosphate deposits are associated with ancient reworked crust. Under the Precambrian subduction setting, continuous arc magmatism promoted juvenile crust growth, whereas asthenospheric upwelling facilitated ancient crustal reworking, jointly controlling the spatiotemporal distribution of metallogenic systems along the western margin of the Yangtze Craton. Full article

The Fujin Basin (FJ Basin) is a Cenozoic sedimentary basin located in the northern Junggar Basin. In response to key scientific issues, including unclear stratigraphic distribution and an inadequately constrained structural framework, this study utilizes measured resistivity data acquired through the controlled-source sounding method. By integrating profile interpretation and numerical simulation, the geological structure and stratigraphic distribution of the basin are investigated, and the exploration potential for deep oil and gas resources as well as shallow sandstone-hosted uranium deposits is evaluated. Using known logging resistivity curves, electromagnetic frequency responses at different burial depths were simulated to verify the effectiveness of the acquisition parameters and survey design for detecting strata ranging from shallow Tertiary formations to deep Carboniferous sequences. Based on the processed data, combined with the known physical properties of the strata and comprehensive geological interpretation, the geological structure, stratigraphic distribution, and tectonic framework of the FJ Basin were clarified. Integrated with borehole geochemical data, the CSEM resistivity sections suggest that the Upper Carboniferous Haerjiawu Formation constitutes a potential hydrocarbon source rock within the JTL sag, warranting further drilling verification. In addition, resistivity attributes and dual-frequency phase attributes were employed to predict the metallogenic conditions and favorable targets for shallow Tertiary sandstone-hosted uranium mineralization. The prediction results show strong consistency with known uranium deposits, providing important guidance for uranium exploration. The methodology proposed in this study can serve as a technical reference for integrated multi-mineral exploration in similar regions. Full article

Three-dimensional (3D) technologies are increasingly used to digitize rocks, minerals, fossils, landforms, and other geological objects, but classroom evidence for their instructional value in mineral and resource geoscience remains limited. This quasi-experimental study examined whether tangible 3D-printed models were associated with higher immediate post-instruction performance than image-based instruction, and how their value varies with the representational demands of different geoscience tasks. The sample included 135 secondary students. The 3D-printing Group (n = 54) used tangible models, whereas the Traditional Group (n = 81) received image-based instruction across four topics: Cradle Stone, the Jiaodong-type Mineral System, Anchiornis huxleyi, and Detached Cave Dwellings. Baseline-adjusted analysis of covariance (ANCOVA) was used as the primary inferential test. The 3D-printing Group showed higher immediate post-test performance (adjusted means: 79.46% vs. 71.51%; difference = 7.95 percentage points; HC3 95% CI: 2.10–13.80; p = 0.008). The largest topic-specific advantage occurred for Anchiornis huxleyi, consistent with a task-dependent interpretation in which printed models are more useful when learning requires three-dimensional morphological interpretation. Questionnaire responses also favored 3D printing, especially for perceived spatial understanding. These preliminary classroom-based findings suggest that 3D-printed models are most useful when they preserve task-relevant spatial, structural, or morphological information. Full article

The Casas Novas gold deposit is located in the Escoural Gold District of the Ossa Morena Zone (OMZ, SW Iberia) and consists of an orogenic gold system characterized by structurally controlled mesothermal lodes, which are related to a major shear zone. The mineralization shows evidence of two distinct metallogenic phases during regional metamorphism: (i) an early higher-temperature stage marked by Co-Ni-rich loellingite hosting Au-(Ag) alloys accompanied by pyrrhotite, and (ii) a later low-temperature stage with arsenopyrite, gold, maldonite and Bi-Te sulfosalts. Detailed textural analysis documents the evolution from initial Au-Ag alloys enclosed in Co-Ni-rich loellingite to subsequent Au-Bi-Te phases and newly formed arsenopyrite. The results show the thermal and chemical changes in the system, demonstrating the importance of fluid–rock interactions in the redox conditions, which became more oxidized, controlling the gold deposition. The comprehensive overview of the processes that led to the concentration of gold in the Casas Novas deposit provides a valuable contribution to the ongoing studies into the auriferous region of the Escoural Gold District. Full article

The North China Craton hosts abundant skarn iron resources, yet the regional large-scale mineralization mechanism remains incompletely understood. The Litun deposit is a newly discovered skarn iron deposit in the North China Craton. Integrated field geological investigations, petrographic observations, fluid inclusion microthermometry and stable isotope geochemistry are applied to constrain evaporite contributions to metallogenic processes. Four mineralization stages are identified: skarn, oxide, sulfide, and carbonate. Early skarn-stage fluids are iron-rich magmatic hydrothermal fluids with high temperatures (498 to >550 °C), high salinities (18.6 to 59.4 wt% NaCl eqv.), and magmatic δ¹⁸O values of 8.3 to 10.8‰. Subsequent oxide to late carbonate stages record continuous infiltration of meteoric water, supported by H–O isotopic trends of rising meteoric water proportions. Pyrite from the magnetite ores has δ³⁴S_V-CDT values between 12.0 and 15.0‰, significantly higher than those of pyrite in the Litun diorite (−0.8 to 1.1‰), indicating the contributions of sulfur from evaporites (δ³⁴S_V-CDT 26.9 to 28.6‰) in the mineralization process. Moreover, vein pyrite formed in later stages displays even higher δ³⁴S values (17.3 to 20.9‰), demonstrating progressive enrichment of evaporite-derived sulfur as hydrothermal activity evolves. Synchronous rises in meteoric water fraction and evaporite sulfur proportion indicate evaporites are delivered into the ore-forming system via meteoric water mixing. The mixing of meteoric water containing dissolved evaporites and iron-rich magmatic-hydrothermal fluids may be the major mechanism of magnetite precipitation in the Litun deposit. Full article

The Songpan-Ganzi and Eastern Kunlun region on the northern margin of the Tibetan Plateau is a key area for the evolution of the Paleo-Tethys tectonic domain and hosts abundant gold, lithium, and polymetallic mineral resources. To reveal the deep structure of this region and its metallogenic background, this study constructed a lithospheric electrical structure model based on magnetotelluric (MT) data along a profile traversing tectonic units such as the Qiangtang, Songpan-Ganzi, and Eastern Kunlun blocks. Data processing, dimensionality analysis, and two-dimensional inversion were performed. The results show that a large-scale, funnel-shaped conductor, originating from the upper mantle and penetrating the middle-lower crust, exists beneath the Songpan-Ganzi and Qiangtang terranes, indicating a major channel for deep-seated thermal material upwelling. Driven by Cenozoic tectonic reactivation, the thermal materials ascended along pre-existing lithospheric weak zones formed during the closure of the Paleo-Tethys Ocean. It spread extensively within the upper-middle crust of the Songpan-Ganzi terrane and migrated to the Eastern Kunlun orogenic belt via complex fault systems, ultimately forming low-resistivity bodies that closely coincide with the locations of major shallow ore-controlling faults. This electrical model suggests the presence of a “thermal material channel” system extending from the mantle to the shallow crust. The study suggests that the migration pathways of ore-forming fluids, represented by gold deposits in the Eastern Kunlun metallogenic belt, are highly correlated with the fault-magma channel system constituted by intra-crustal conductors. In contrast, the lithium-rich granitic magmatism associated with lithium mineralization within the Songpan-Ganzi terrane may be related to the deep thermal background reflected by the large-scale conductor in the upper mantle. From the perspective of electrical structure, this study suggests that mineralization in this region may be closely linked to deep crust–mantle processes. The reactivation of pre-existing tectonic-magmatic channels by Cenozoic thermal material is key to controlling the distribution pattern of dominant shallow mineral resources. The research results provide important geophysical constraints for a deeper understanding of the tectonic–magmatic–mineralization coupling mechanism on the northern margin of the Tibetan Plateau. Full article

The Huize Ge-rich Pb-Zn deposit is an important part of the Sichuan–Yunnan–Guizhou carbonate-hosted Pb-Zn metallogenic area and is one of the most representative super-large deposits in the northeastern Yunnan Pb-Zn ore concentration area. The orebodies mainly occur in NE-trending interlayer fault zones. The Pb-Zn mineralization process of this deposit can be divided into the dolomite stage (I), sphalerite-galena stage (II), galena-sphalerite stage (III), and pyrite-calcite stage (IV). Based on a study of the deposit geology, we utilized LA-ICP-MS for in situ microanalysis of trace element compositions and element mapping of sphalerite from different stages to reveal the characteristics of the sphalerite trace element composition and occurrence mechanisms, understand the mineralization process, and constrain the genetic type of the deposit. This research shows that sphalerite color variations result from the multi-factor coupling of multiple trace element contents, element associations, and isomorphic substitutions among elements. Trace elements such as Mn, Fe, Cu, Ga, Ge, Ag, Cd, In, Sn, Sb, and Hg occur in the sphalerite lattice in the form of isomorphic substitutions or nanoscale mineral inclusions, whereas Pb occurs mainly as microscopic mineral inclusions (galena) in sphalerite. From the early to late stages of mineralization (SpI → SpII → SpIII), the mineralization temperature (132–205 °C) and sulfur fugacity (log₁₀ fS₂ = −15.29 to −19.89) both show a gradual decrease. During sphalerite crystallization in different stages, multiple trace elements exhibit coupled multi-element substitutions at the microscale: SpI: Zn²⁺ ↔ (Fe²⁺, Mn²⁺, Cd²⁺), 2Zn²⁺ ↔ 2Ag⁺ + Ge²⁺; SpII: Zn²⁺ ↔ (Fe²⁺, Cd²⁺), 2Zn²⁺ ↔ 2Ag⁺ + Ge²⁺, 3Zn²⁺ ↔ 2Cu²⁺ + Ge²⁺, 3Zn²⁺ ↔ 2(Cu, Ag)²⁺ + Ge²⁺, 2Zn²⁺ ↔ Ga³⁺ + Cu⁺, 2Zn²⁺ ↔ Ga³⁺ + (Cu, Ag)⁺; and SpIII: Zn²⁺ ↔ (Fe²⁺, Mn²⁺), 3Zn²⁺ ↔ 2Cu²⁺ + Ge²⁺, 3Zn²⁺ ↔ 2(Cu, Ag)²⁺ + Ge²⁺). Mn, Fe, and Ge are mainly enriched in SpI; Ga and Ag are mainly enriched in SpII; and Cd is mainly enriched in both SpI and SpII. By comparing the sphalerite trace elements signature of the Huize Ge-rich deposit with those of global typical MVT, SEDEX, VMS, epithermal, and skarn-type Pb-Zn deposits, and considering the deposit’s geological and geochemical characteristics, we suggest that the Huize Pb-Zn deposit is best classified as a medium- to low-temperature, carbonate-hosted Pb-Zn deposit. Full article

The complex geochemical behaviors of manganese (Mn) enrichment processes remain insufficiently understood, which hinders a deeper understanding of the formation mechanism of sedimentary Mn deposits. A systematic geochemical analysis of a continuous drill-core profile is very important for understanding the Mn enrichment process. This study focuses on the Muhu large Mn deposit, located in the eastern segment of the Markansu metallogenic belt, western Kunlun Mountains. The vertical changes of Mn ore, Mn-bearing black rocks, and wall rocks were systematically evaluated through a single-borehole core section, including their geological characteristics, lithogeochemistry, and paleoenvironmental indicators, revealing the ore genesis of the Muhu deposit. The results indicate that during the initial Mn deposition in the Muhu area, the geochemical environment was relatively oxidized, with relatively high paleosalinity, comparatively low primary productivity, and a relatively deep redox interface. The sedimentary basin was influenced by open-marine seawater and accompanied by the input of hydrothermal materials. The redox conditions of basin waters likely played an important role in controlling the geochemical behavior of Mn cycling, and these oxides initially enriched were subsequently reduced in the presence of organic matter, ultimately contributing to the formation of Mn carbonate ore. Accordingly, a three-stage process of “oxidation–reduction–mineralization” is proposed for the Muhu (Markansu) Mn carbonate deposit. This refined evolutionary model provides further constraints for understanding the metallogenic mechanism of marine sedimentary Mn deposits. Full article

The Bastielieke W-polymetallic deposit, located in the Xinjiang Altay metallogenic belt, records a complex hydrothermal history critical to understanding multi-stage metallogenic processes in the southern Altay. This study integrates in situ U-Pb dating of hydrothermal titanite and zircon with textural and compositional analyses of titanite to reconstruct this history. Three types of hydrothermal titanite, identified from pyroxene skarn (TtnI), epidote skarn (TtnII), and quartz–sulfide ore (TtnIII), display dissolution–reprecipitation textures and systematic compositional variations, indicating distinct fluid compositions and origins. TtnI, TtnII, and TtnIII yield U-Pb ages of 244.7 ± 7.8 Ma, 252.4 ± 5.5 Ma, and 250.6 ± 3.0 Ma, respectively, and hydrothermal zircon from pyroxene skarn yields an age of 249.9 ± 2.1 Ma, constraining the hydrothermal event to the latest Permian to Early Triassic. These ages are interpreted to record the timing of U-Pb system resetting during regional shear–thrust movements. Compositional variations among the three titanite types reveal a two-stage hydrothermal history. The earlier stage involved W–Cu mineralization and protolith titanite precipitation related to magmatic–hydrothermal fluids exsolved from Permian granites. The later stage was driven by regional shear–thrust movements and metamorphic–hydrothermal processes, which reset the titanite U-Pb systems, partially altered TtnI and TtnII, precipitated TtnIII, and remobilized metals. This model links the Bastielieke deposit to multi-stage hydrothermal processes and provides insights into similar metallogenic events along the southern margin of Xinjiang Altay. Full article