Search Results (496)

Feldspar and quartz are essential ceramic raw materials, with feldspar acting as a flux and quartz as a structural filler. Feldspathic sand derived from granitic masses of the eastern Arabian Shield represents a promising local source. This study evaluates upgraded granitic detritus, commercially termed silspar, from the Khurs granite of the Dawadimi terrane. Twenty-five samples were chemically and technologically characterized; one compositionally anomalous sample (S2) was retained in the analytical tables for transparency but excluded before resource-level statistical preprocessing. Pearson correlation, principal component analysis and Ward hierarchical clustering were applied to 24 representative samples using eight chemical variables, while shrinkage, loss on ignition (LOI), whiteness (L*) and water absorption were used for external technological validation. Four chemistry-defined groups were identified: S1 and S3 form a dark impurity-rich pair; S4–S9 form the cleanest ceramic-grade group; S10–S13, S15–S17 and S24 define a transitional Ca-Fe-influenced group; and S14, S18–S23 and S25 form a more coherent potassic group. The firing variables differ significantly among the chemistry-defined groups under the standardized laboratory procedure. The results support controlled ceramic use of the representative Khurs-derived silspar, subject to stockpile homogenization and impurity control. Because phase proportions are normative estimates rather than direct XRD determinations, the work is presented as an integrated preliminary industrial-mineral screening assessment rather than a complete quantitative mineral-phase characterization. Full article

Granite residual and slope-wash soils are important disaster-prone geological bodies in the hilly and mountainous areas of Hunan Province, China. Their engineering classification has long relied on manual visual inspection and laboratory testing, which is inefficient and subjective. In this study, an automatic classification method based on deep learning image recognition is proposed for granite residual and slope-wash soils in the mountainous areas of Hunan Province. First, a three-class primary classification scheme was established, comprising residual clay (RNC), residual sandy clay (RNSC), and residual gravelly clay (RNGC), based primarily on the gravel content of particles larger than 2 mm (RNC < 5%, RNSC 5–20%, RNGC > 20%). Second, 7678 geotechnical test records from 21 counties in Hunan Province were collected, and classification labels were assigned through a strategy combining manual verification and automatic inference using Random Forest (5-fold cross-validation macro F1 = 0.913). From approximately 10,096 original field images, 3380 pure soil image patches were retained after segmentation and screening. A dataset of 43,940 samples was then generated through two-stage preprocessing (including denoising and illumination correction) and 13-fold data augmentation. A CNN image classification model was constructed based on a ResNet18 backbone network pre-trained on ImageNet. On the independent test set (6591 images), the primary classification accuracy reached 91.46%, with a macro F1-score of 0.9128; the per-class F1-scores for RNC, RNSC, and RNGC were 0.921, 0.885, and 0.933, respectively. Grad-CAM visualization analysis demonstrated that the model’s attention was primarily focused on soil particle distribution regions rather than non-soil background areas, confirming the effective learning of mixed-grain features. The study shows that the combined application of transfer learning and 13-fold data augmentation can significantly improve classification performance under limited sample size conditions (an improvement of 15.33 percentage points compared to the baseline of 76.13%), demonstrating promising potential for engineering applications. Full article

High-speed projectile impact is a promising approach for assisting hard-rock fragmentation; however, the coupled effects of projectile geometry and impact velocity on crater formation and penetration behavior under lateral confinement remain insufficiently understood. In this study, seven granite penetration tests were conducted using a biomass-fueled combustion-driven gas gun system coupled with a biaxial lateral confinement device, including one unconfined case and six cases under 2 MPa lateral confinement. Equal-mass YG20 cemented carbide projectiles with cone angles of 60°, 90°, and 120° were tested at nominal velocities of approximately 220 and 400 m/s. The results show that the two velocity levels produced different crater morphologies, and cone angle regulated the relative development of axial penetration and transverse crater expansion. At the lower velocity level, surface crushing dominated, with penetration depth decreasing from 13.5 to 10.5 mm and equivalent crater diameter decreasing from 74.5 to 44.4 mm as cone angle increased. At the higher velocity level, funnel-shaped craters were formed, with penetration depth decreasing from 45.0 to 30.0 mm, while equivalent crater diameter exhibited a non-monotonic variation. Dynamic strain measurements revealed coupled radial compression and circumferential tensile responses, with more complex transient fluctuations observed for the 120° projectile at high velocity. Based on the Young/Sandia framework, a condition-specific penetration-depth correlation was established. The full seven-test calibration gave an in-sample RMSE of 1.87 mm and R² = 0.977, while leave-one-condition-out evaluation of the five conditions not used to define the paired-test boundary-state reduction ratio K₂ yielded an RMSE of 3.40 mm and R² = 0.937. The held-out analysis is interpreted as an internal stability check rather than independent external validation. These findings provide insights into the coupled influence of projectile cone angle and impact velocity on granite crater formation under controlled lateral confinement. Full article

Hydraulic fracturing in low-permeability porous rocks involves strong interactions between rock deformation, pore fluid transport, and progressive fracture damage. In this study, a hydro-mechanical phase-field model was developed to investigate hydraulic fracture evolution in saturated porous media. Biot poroelasticity, tensile–compressive strain energy decomposition, irreversible phase-field fracture evolution, and damage-dependent permeability were incorporated within a common finite element framework. The model was implemented in COMSOL Multiphysics 6.4 and used to examine the effects of the horizontal principal stress difference, injection rate, and fracturing fluid viscosity on the fracture morphology and pressure response. Within the investigated parameter ranges, increasing the horizontal principal stress difference from 2 to 14 MPa reduced the stimulated fracture area from 42,640 to 21,300 m² (50.0%) and the number of secondary branches from 12 to 5. Increasing the injection rate from 3 to 6 m³/min increased the stimulated fracture area from 35,771 to 44,138 m² (23.4%), the branch count from 6 to 11, and the breakdown pressure from 135.19 to 162.11 MPa (19.9%). Increasing the fluid viscosity from 1 to 100 mPa·s increased the stimulated fracture area from 35,771 to 48,722 m² (36.2%) and the breakdown pressure from 135.19 to 183.21 MPa (35.5%). The injection rate sensitivity was also compared with published granite hydraulic fracturing experiments, which demonstrated a positive increase in breakdown pressure with injection rate. This comparison was interpreted as trend-level physical consistency rather than direct material-specific validation because the experimental and numerical systems differed in their rock type, scale, stress state, temperature, and injection rate range. The results demonstrated systematic sensitivities of the hydraulic fracture geometry and pressure response within the investigated two-dimensional model configuration. Full article

To characterise the fracture network geometry of a fluid reservoir, fundamental parameters are used in a DFN simulation algorithm. However, evaluating the hydrodynamic behaviour of such rock bodies also requires apertures of individual fractures. Aperture is usually not treated as an independent variable; rather, it is derived from length. A common approach is a linear relationship, a = A × L, where A is the aperture coefficient. The fracture’s free volume varies with the aperture coefficient, which influences the modelled fractured porosity and permeability. Since post-tectonic fluid–rock interactions can considerably alter the original apertures, the relationship between fracture length and aperture may vary across a reservoir, complicating hydrodynamic modelling. Therefore, from a hydrodynamic perspective, the hydraulic aperture should be used instead of the physical aperture. In this paper, transmissivity data and DFN models are analysed simultaneously to estimate reliable aperture coefficients. The method is demonstrated using the fractured Mórágy granite body in SW Hungary. In the context of the radioactive waste depository project, numerous wells penetrated the fractured granite. Transmissivity data and DFN models from 238 intervals are used to calibrate aperture coefficient values. The associated porosity data are employed to construct a porosity log for each well and analyse poro-perm diagrams. Full article

The Xiaoyinuogaigou (XYN) gold deposit is located in the central Erguna Metallogenic Belt, northeastern China, and represents a characteristic example of Mesozoic gold mineralization in the Mongol–Okhotsk orogenic province. Despite its economic significance, the timing of mineralization and the nature of the ore-forming fluid system have not been well constrained. To address these questions, a systematic investigation of fluid inclusions, isotopes, geochemistry, and geochronology was conducted. The study reveals that: (i) four types of fluid inclusions are identified in auriferous quartz veins, with co-existing aqueous liquid-vapor and NaCl daughter-mineral three-phase inclusions, indicating the involvement of at least two chemically distinct fluids; (ii) the ore-forming fluids are characterized by moderate temperatures (163.2–357.6 °C), low to moderate salinities (3.06–11.34 wt% NaCleqv.), and H–O isotope compositions (δD = −133.3 to −112.3‰; δ¹⁸O fluid (SMOW) = +1.74 to +4.06‰) consistent with a hydrothermal system incorporating a substantial non-magmatic water component; and (iii) REE geochemistry and sulfur isotopes (δ³⁴S = +4.47 to +11.75‰, mean +8.29‰, n = 4) indicate that ore-forming materials were derived at least in part from the ore-hosting granite porphyry. Zircon U–Pb geochronology constrains the granite porphyry crystallization to 180 ± 3 Ma, and hydrothermal monazite U–Pb dating yields an age of 162.3 ± 3.6 Ma (MSWD = 0.95), for a Middle Jurassic hydrothermal event. We therefore conclude that XYN is an epizonal orogenic gold deposit formed during the late compressional to post-collisional transition of the Mongol–Okhotsk orogeny. Full article

For lithium-ion batteries, reliable fault detection for charging voltage is essential for operational safety and thermal failure prevention. However, existing battery monitoring solutions face a dual challenge: task-specific models are primarily challenged by limited transferability, while powerful foundation models impose prohibitive computational demands that preclude their integration into resource-constrained edge devices. To address these challenges, this paper proposes a lightweight foundation model for fault detection built upon the IBM Granite TinyTimeMixer (TTM) foundation model. Firstly, we fine-tune the pre-trained TTM backbone with a hybrid loss using only few-shot normal charging sequences, enabling the model to learn the healthy voltage dynamics of batteries. Secondly, a dual-track data pipeline is proposed to adapt to irregular data, where a regular inference grid is generated in parallel with raw asynchronous measurements being retained for preserving vital high-frequency components. Thirdly, a vertical residual alignment mechanism is introduced to align irregular measurements with a continuous prediction curve derived from the TTM model’s grid prediction, enabling precise residual computation despite sampling mismatches. Finally, an empirical 99.99th quantile extreme threshold is calibrated using normal residual distributions to suppress false alarms caused by heavy-tailed sensor noise. Experiments on a lab dataset of 174 battery cells demonstrate that the proposed foundation model detects all fault batteries with zero false positives, which validates its effectiveness and robustness in battery fault detection. Full article

The selection of materials for enhancing the energy performance of historic mosque structures, which form a significant part of Türkiye’s cultural heritage, should be based on scientifically supported methodologies and should also consider their architectural nature. In this work, an innovative Energy3D–MADA approach is developed for the comparative evaluation of thermal performance and sustainable selection of heritage natural stones. The proposed framework concentrates on the thermal aspect, while environmental, economic, mechanical, and material-related acoustic indicators are used as supplementary decision indicators. The study examined eight representative heritage natural stones using a representative Ottoman composite masonry wall. For the four climatic regions of Türkiye, the energy performance was predicted, and 32 scenarios were obtained. The annual heating and cooling energy requirements, total operational energy, operational CO₂ emissions, and costs of wall manufacturing were investigated through Energy3D. The results of the simulation indicated that the natural stones had a considerable impact on the performance of historic mosque buildings. Od Stone (Tuff) had the lowest heating and cooling annual energy demand, the minimum total operational energy consumption, and the fewest operational CO₂ emissions among all the alternatives considered, while Red Granite had the greatest energy demand. Compared to Red Granite, Od Stone achieved reductions in annual heating energy of 31%, in total operational energy consumption of 22–25%, and in operational CO₂ emissions of 22–25%, with only about a 1% increase in initial construction cost. Spearman’s rank correlation analysis (ρ) indicated the same ranking in all climate regions, which demonstrated the ranking consistency of the Energy3D-based comparative analysis. Ultimately, the Energy3D simulation outcomes were combined with the LODECI, MEREC, SPC, SIWEC-M, and ALPAS techniques to formulate a decision-support system for the comparative analysis and prioritization of heritage natural stones, to support sustainable mosque design and heritage conservation planning. Full article

The objective of this study is to systematically evaluate the reinforcement mechanisms of layered double hydroxides (LDHs) on the aggregate–asphalt interfacial adhesion in granite–asphalt systems under accelerated ultraviolet (UV) aging. The interfacial bonding durability of granite–asphalt composite systems is persistently threatened by hydrothermal stripping and UV weathering. A multiscale experimental framework comprising boiling kinetic tests, photoelectric colorimetry, and surface free energy (SFE) analysis based on the van Oss–Chaudhury–Good theory was executed, complemented by cross-sectional scanning electron microscopy (SEM). Macroscopic results demonstrate that a 3.0 wt.% LDH threshold optimizes the hydrothermal adhesion rating to Level 5. Thermodynamically, introducing 4.5 wt.% LDHs triggers a 176.37% surge in the polar SFE component (${\gamma }_S^{\mathit{AB}}$), causing the dry adhesion work ($W_{\mathit{AS}}$) to peak and the wet stripping work ($W_{\mathit{ALS}}$) to plummet by 45.03%, verifying a significantly compressed driving force for moisture displacement. A reconciliation of these dosage-dependent results establishes 4.5 wt.% as the scientifically optimal formulation for maximizing long-term thermodynamic stability. Microstructural SEM analysis reveals that LDHs transition the terminal UV-degradation behavior from severe, reticulated brittle macro-cracking into highly controlled, damage-tolerant micro-fissuring. These findings provide thermodynamic targets and mechanistic insights that can guide the design of durable, weather-resistant asphalt pavements. Full article

With the accelerated advancement of smart city construction, the development of urban underground space in coastal areas faces significant safety challenges due to randomly distributed granite boulders. Conventional geophysical methods often struggle to identify these heterogeneous bodies efficiently. This study proposes a comprehensive detection approach fusing the Cone-based Transient Electromagnetic Method (CTEM) and Microtremor Array Surveying. Taking the eastern coast of Jiaozhou Bay, Qingdao, as the research area, we integrated borehole data to validate the geophysical interpretation. The results demonstrate that the joint inversion accurately delineates four stratigraphic interfaces with depths consistent with borehole logs: the artificial fill (bottom at ~8–12 m), Quaternary sediments (~28–33 m), strongly weathered granite (~59–74 m), and moderately weathered granite. Specifically, boulders within the Quaternary and strongly weathered layers are distinctly identified by dual high-value anomalies: high apparent resistivity (>220 Ωm, approximately 1.5–2 times that of the surrounding rock) and high shear-wave velocity (>660 m/s). Furthermore, the method effectively differentiates boulders from water-rich fractured zones, which exhibit contrasting low resistivity (<50 Ωm) and low shear-wave velocity (<420 m/s). These quantitative findings confirm that the fused CTEM and microtremor technique provides precise spatial localization and reliable identification of boulders in complex coastal geological environments. Full article

Ion-adsorption rare earth deposits (IADs) constitute the primary global source of medium-to-heavy rare earth elements. The sustainable exploitation of these resources hinges on the precise characterization of the weathered crust architecture and its hydrogeological properties. Conventional drilling often fails to resolve the complex vertical heterogeneity of regolith profiles, thereby limiting orebody delineation and the optimization of in situ leaching (ISL). To address this, this study integrates Electrical Resistivity Tomography (ERT) with Archie’s Law and the Kozeny–Carman equation. Focusing on the YZK1 and YZK2 survey lines in the Dabu mining area, southern Jiangxi, we derived 2D distributions of porosity and permeability from resistivity inversions. Our results delineate the weathered crust into four distinct vertical strata: a surface accumulation layer, a completely-to-highly weathered granite layer, a moderately-to-slightly weathered layer, and fresh bedrock. Quantitatively, the completely-to-highly weathered layer exhibits a “low resistivity (10–700 Ω·m)–high porosity (8.7%–17%)–high permeability (0.04–1.2 mD)” mode, serving as the primary leachable reservoir. In contrast, the surface and moderately weathered layers display “high resistivity (>800 Ω·m)–low porosity (3.4%–6.4%)–low permeability (0.01–0.04 mD)” characteristics. Crucially, although the fractured bedrock zones on both YZK1 and YZK2 profiles exhibit similar absolute permeability values (~0.016 mD), they represent two distinct hydraulic architectures. On the YZK1 profile, the fractured zone acts as a relatively homogeneous potential leakage pathway. Conversely, the YZK2 profile displays significant vertical segmentation: the upper and lower margins function as permeable pathways, while the central core, likely infilled with fault gouge, acts as a sealing zone that impedes fluid flow. Consequently, resistivity data alone are insufficient to accurately assess hydraulic conductivity; joint interpretation incorporating both permeability and porosity is essential to definitively determine whether a fault zone acts as a “conduit” or a “barrier.” By transitioning from qualitative imaging to quantitative parameter evaluation, this study provides a robust technical paradigm for fine-scale exploration and ISL optimization in IADs. Full article

Background: Wild foods and geophagic material are important in the nutrition of communities along Zimbabwe’s Great Dyke, a serpentinic ultramafic (SUG) and surrounding granitic geological (GG) environment. However, the health risks associated with consumption of these in terms of toxic geogenic contaminants (TGC) is largely unknown. The study objective was to evaluate the health risks associated with consuming wild foods and geophagic materials from these environments. Methods: Health risk assessments were determined using the hazard quotient, hazard index (HI) and life cancer risk (LCR) for 10 TGCs in wild foods and geophagic material. Results: High human health risks (HI ≥ 1) were found in six wild foods and geophagic material under the SUG environment compared with five wild foods and geophagic material under the GG environment. Wild foods and geophagic materials exceeded the tolerable risk level of 1 × 10⁻⁴. Their LCR values ranged from 2.11 × 10⁻¹ to 6.83 × 10⁻⁷. All TGCs had high LCR values above the tolerable risk level, except for Cu, Fe, Mn and Zn. Conclusions: Infusion reduced the LCR values for TGCs, with only Pb in the GG environment decreasing to below tolerable risk level. Communities should apply selective consumption and avoid F. sycomorus and geophagic materials with cancer risks. Full article

The Tieshilong Pb-Zn polymetallic district is located along the northern margin of the Dongpo ore field in the middle section of the Nanling metallogenic belt, southern Hunan, China. It represents a typical granite-related, fault-controlled hydrothermal vein-type lead–zinc polymetallic deposit in southern Hunan. In recent years, large-scale tin mineralization has been newly discovered during exploration in the deeper and peripheral areas of the district. However, the timing and genetic nature of this tin mineralization remain undetermined, which limits understanding of the characteristics of the deposit’s metallogenic system and its deep exploration potential. In this study, we present in situ cassiterite U–Pb geochronology and trace element data from deep Pb-Zn-Sn orebodies in the Tieshilong mining district. LA-ICP-MS U-Pb analyses of cassiterite yield a Tera–Wasserburg lower-intercept age of 159.2 ± 6.2 Ma (MSWD = 1.4), indicating that Sn mineralization occurred during the Late Jurassic. This age overlaps, within uncertainty, with the main ca. 160~150 Ma W–Sn metallogenic event recognized throughout the Nanling belt. Trace element data reveal that Tieshilong cassiterite is enriched in Fe (1100–5800 ppm) and W (120–11,660 ppm), and depleted in Nb (0.1–87 ppm) and Ta (0–7.1 ppm). The Zr/Hf ratios range from 23 to 52, with a mean value of approximately ~36, which is close to the chondritic values. These geochemical signatures, together with the occurrence of cassiterite intergrown with hydrothermal quartz and its replacement by later sulfides, support precipitation from a granite-related magmatic–hydrothermal system. Based on the findings and the literature, the Tieshilong deposit is therefore interpreted as a Pb–Zn-dominant expression of a Late Jurassic granite-related polymetallic system, in which deeper Sn ± W mineralization was overprinted by later Pb–Zn–Cu sulfide mineralization along fault-controlled fluid pathways. The recognition of cassiterite-bearing, medium- to high-temperature assemblages at depth suggests that down-dip extensions, fault intersections, and strike-inflection zones of the ore-controlling structures represent priority targets for future exploration. Full article

The Huomaxie granite in Ningdu, southern Jiangxi Province, is located in the central part of the Cathaysia Block. Previous studies assigned this pluton to the Huitong batholith as S-type granite, but lacked precise geochronological and petrogenetic constraints. This paper presents systematic petrography, whole-rock geochemistry, zircon U–Pb dating, in situ Hf isotopic analysis, and electron microprobe analysis (EPMA) of muscovite from the muscovite monzogranite of the pluton. The weighted mean ²⁰⁶Pb/²³⁸U age is 420.1 ± 3.1 Ma. The rocks are silicic, high-K calc-alkaline, and peraluminous S-type granites. Zircon ε_Hf(t) values range from −15.0 to −11.8, with two-stage Hf model ages (T_DM2) of 2360–2150 Ma. Geochemical characteristics and muscovite composition data indicate that the magma was derived from high-temperature partial melting of psammitic sedimentary rocks. Tectonic discrimination diagrams suggest that the pluton formed in a post-orogenic extensional setting. It was generated by lower crustal melting induced by asthenospheric upwelling. Full article

The Gebel Shalman-Wadi Biarn (GSh-WB) area in Egypt’s South Eastern Desert hosts NYF-type rare-metal pegmatites with significant U, Th, Nb-Ta, and REEs mineralization. This study integrates field observations, petrography, mineralogy, whole-rock geochemistry, and gamma-ray spectrometry to characterize these pegmatites and evaluate their economic potential. The pegmatites occur as veins, dykes, and zoned pockets hosted entirely within syenogranites. Petrography, pegmatites, and syenogranites are primarily composed of K-feldspar, albite, and quartz with trace amounts of biotite and muscovite. The environmental scanning electron microscope (ESEM) revealed the presence of the following minerals: autunite, kasolite, thorite, monazite-(Ce), parisite, xenotime-(Y), ferrocolumbite, hydroxyplumbobrtafite, aeschynite-(Y), and zircon, which are the major U-Th, Nb-Ta, and REE-bearing minerals. Additionally, gold, cassiterite, wolframite, pyrrhotite, chalcopyrite, and brass alloy were identified as sources of precious and base metals. Both groups’ chondrite-normalized REE patterns, which display slightly elevated LREE patterns and negative Eu anomalies, point to fractional crystallization involving plagioclase fractionation. Consequently, pegmatite and syenogranites are believed to have mostly formed from the partial melting of a reconstituted juvenile crust and its weathered sediments associated with Neoproterozoic magmatism. The marginally positive Ce anomaly in the (GSh-WB) pegmatites (1.02–0.98) may be associated with monazite crystallization resulting from enhanced fractionation. The Th and U levels range from 101 to 28.6 ppm and from 51 to 5.8 ppm, respectively. The magnitude of the tetrad effect in the rare earth elements of the analyzed rocks exceeds one (T1 = 1.12–1.02, T3 = 0.92–1.08, and T1,3 = 1.01–1.05), suggesting an M-type tetrad effect. The presence of this tetrad effect is indicative of granite that has been significantly altered by hydrothermal processes and is extensively fractionated. Chondrite-normalized REE patterns of the pegmatites (average ΣREE = 439 ppm) and their host syenogranites (average ΣREE = 192 ppm) show similar trends characterized by enrichment of light rare earth elements (LREEs) relative to heavy rare earth elements (HREEs) and pronounced negative Eu anomalies (Eu/Eu* = 0.09–0.22). These features, together with negative Sr and Ba anomalies, likely reflect extensive fractional crystallization of feldspars and feature anorogenic rocks. Spectrometric analysis reveals eU values of 2.0–288 ppm and eTh values of 7.0–455 ppm in pegmatite samples, with eU/eTh ratios (0.49–0.39) exceeding the typical continental crust value of 0.25, indicating uranium enrichment. Both magmatic and hydrothermal processes contributed to the observed radioactivity. The spatial distribution of uranium shows lithological and structural controls. The GSh-WB pegmatites represent a potential target for uranium exploration. Full article