This paper presents the first zircon trace element geochemistry, combined with U-Pb geochronology data, of the Paleoproterozoic K-rich granitoids (KRGs) in the Bole-Nangodi greenstone belt of the West African Craton (WAC) in northern Ghana. The study aimed to constrain the timing of emplacement, magma source characteristics, and petrogenetic processes of the KRGs. The studied KRGs of the Bole-Nangodi Belt include hornblende granite and granodiorite. The zircons from the KRGs contain high abundances of Hf, ΣREE, Pb, Th, and U, indicating a high degree of magmatic evolution, with contemporaneous magmatism occurring between ca. 2120 and ca. 2092 Ma. Chondrite-normalised REE patterns of zircons from the KRGs of the Bole-Nangodi belt show mainly positive Ce anomalies and slightly positive to weakly negative Eu anomalies, suggesting crystallisation under high oxygen fugacity conditions. The studied zircon were derived from magmas of continental crust origin and were subsequently affected by hydrothermal alteration, indicated by their Th/U, (Sm/La)N, Ce/Ce*, Nb/Ta and Hf/Y ratios, weak oscillatory zoning and somewhat metamict patterns, and relative enrichment of light rare earth elements. The evaluation of U-Pb age data suggests that the emplacement of the KRGs was non-systematic. Consequently, there is no distinct age difference or well-defined sequence of emplacement among the granodiorite and granite in the Bole-Nangodi belt. Therefore, the region is characterised as an undifferentiated terrane that underwent contemporaneous pulses of magmatism during the 2.3–2.1 Ga Eburnean events.
Tight sandstone gas accounts for nearly 30% of China's natural gas production and is an important exploration target in western sedimentary basins. To clarify the accumulation mechanism of the Jurassic tight sandstones in the Taibei Sag, this study integrates sand-body characterisation, source-rock geochemistry, reservoir analysis, tectonic restoration, fluid-inclusion microthermometry, and burial–thermal history modeling within a coal-measure whole petroleum system framework. The Badaowan, Sangonghe, and Xishanyao formations contain three source-rock intervals composed mainly of coal and organic-rich mudstone. A progradational braided-river delta system deposited thick, laterally extensive sandstone bodies in the Sangonghe Formation, while a widespread mudstone at its top acts as a regional caprock. Reservoir space is dominated by dissolution and intercrystalline micropores, with porosity mainly ranging from 3% to 9% and permeability generally below 1 mD. Three hydrocarbon charging stages are identified: Late Jurassic (160–150 Ma), Early Cretaceous (143–100 Ma), and Late Cretaceous–present (67 Ma–present). Two temporal relationships between reservoir evolution and charging are recognised: concurrent densification and hydrocarbon charging, and hydrocarbon charging after densification. Hydrocarbon enrichment is jointly controlled by inherited paleostructural highs, fault-mediated migration, and effective reservoir sweet spots. The principal innovation is the temporal coupling of source–reservoir–caprock–fault configurations with reservoir densification and multiphase charging, which provides a more integrated explanation for tight-sandstone accumulation in Jurassic coal-measure successions.
In this study, the estimation of Ag and Cu grades was performed using Au assay data in the Zarzima deposit, Kurdistan, Iran. To achieve the goal, statistical approaches including non-parametric (Cubic Spline interpolation) and parametric (regression) curve fitting and geostatistical cokriging were employed. Based on the results, grade estimation using the Cubic Spline interpolation demonstrates higher accuracy than the regression approach. Therefore, 3D grade modelling of Ag and Cu was subsequently carried out after data completion using Spline and cokriging methods. A comparison of the 3D Ag grade models indicates that the overall trend of grade variations is consistent between the two models; however, significant discrepancies are observed between them, particularly in the near-surface sections of the deposit. Furthermore, the 3D Cu grade models reveal that the geometric configuration and the spatial extent of the mineralised zone differ between the two models. Through the application of the employed approaches, the increase in the number of known data points enabled the development of robust 3D models for Ag and Cu. In general, when a large number of auxiliary data are available, as in the present study, cokriging estimation – by accounting for the spatial and distance-based relationships among the data – provides a higher level of reliability. As a basis for comparison, the variances of the estimated Ag and Cu data obtained using the statistical interpolation method show increases of 6.25% and 2.87%, respectively, relative to those obtained by cokriging. These models also demonstrate the potential for generalisation and applicability to other similar mineral deposits.
The Permian Wujiaping Formation (WJP FM) in the Sichuan Basin is a significant successor shale gas play to the Silurian Longmaxi Formation. To systematically evaluate the reservoir characteristics of the Permian WJP FM shale, this study integrates multi-scale experimental analyses, including geochemistry, X-ray diffraction (XRD), and field emission scanning electron microscopy (FE-SEM) on core samples from the Nanya Syncline, Sichuan Basin. Results show that the third member (Wu-3 Member), deposited in deep-water shelf facies, is the core reservoir interval. Within it, siliceous shale concentrated in Sublayers 3-6 represents the most favourable lithofacies. This siliceous shale is rich in biogenic silica, with reservoir space dominated by organic-matter-hosted pores and enhanced by lamellation fractures. It exhibits moderate porosity (avg. 5.6%), high gas content (avg. 5.2 m3/t), and high brittleness (brittle minerals 83.95%), with Sublayer 4 identified as the optimal fracturing interval. Organic matter is predominantly Type II1-III kerogen, over-mature (avg. Ro 2.8%), providing abundant gas and organic pores. Reservoir development is governed by three synergistic factors: an anoxic deep-water shelf environment that enabled organic enrichment and biogenic silica formation; over-mature thermal evolution that generated abundant organic pores; and Yanshanian-Himalayan tectonic compression that induced microfracture networks, while the broad, gentle synclinal geometry favoured pressure maintenance and gas preservation. Based on these findings, an evaluation system integrating sedimentary environment, reservoir quality, and preservation conditions is established, and three categories of favourable zones are delineated. The Class I favourable zone in the syncline core is the primary exploration target. This study provides a systematic framework for shale gas potential evaluation in structurally complex areas and direct guidance for well placement and stimulation design.
Sweet spot prediction in saline lacustrine mixed tight oil reservoirs is challenging. This study evaluates the P2l22-3 (PL23) member of the Lucaogou Formation in the Jimusaer Sag using organic geochemistry, XRD, thin sections, FE-SEM, core analysis, and NMR logging. The three sub-layers share similar source-rock conditions (good–excellent TOC, type I–II kerogen, mature), implying organic geochemistry does not cause reservoir-quality differences. Reservoir heterogeneity is controlled by lithofacies, clay mineral assemblages, and pore connectivity. Sub-layer 2 is the best interval, with highest movable porosity (4.63%), oil saturation (79.14%), superior NMR permeability, and good pay continuity. High-quality porosity comprises intergranular, dissolution, and microfracture pores in silty-fine sandstone and dolomitic siltstone. In contrast, smectite enrichment and poorly connected nano- to submicron pores reduce sub-layer 3 quality. Movable porosity is key; a classification integrating movable fluid parameters, type I movable pay thickness, and movable oil reserve abundance supports well placement.
The porosity evolution and diagenetic controls of the middle-late Eocene carbonate rocks of the Pila Spi Formation in the Khanaga section, Bjeel area, were investigated to understand their impact on aquifer potential and quality, which is an important issue for water resource management in carbonate aquifers. The formation, with an overall thickness of 37.5 m, is composed of fractured limestone, marly limestone, and dolomitic limestone, with thin beds of marl and mudstone characterised by karstic fissures and pores. The study is based on petrographic analysis of 25 thin sections, supported by quantitative porosity assessment and diagenetic interpretation. A petrographic analysis of thin sections from the Pila Spi Formation revealed that the matrix is predominantly micrite with minor microspar, containing skeletal grains indicative of a shallow marine environment. While non-skeletal grains are poloids, intraclasts, and monocrystalline quartz. Numerous diagenetic processes, such as micritisation, dolomitisation, physical compaction, solution, cementation, neomorphism, silicification, pyritisation, iron oxidation, and fracturing, influenced the formation. Five porosity types were identified in the Pila Spi carbonate, most of which are of secondary origin. They are fenestral and intraparticle porosities (primary) and moldic, vuggy, and fracture porosities (secondary). Quantitatively, secondary porosity constitutes particularly vuggy and moldic porosities that represent the most common types, with average values of 2.25% and 0.99%. Solution and fracturing processes enhanced porosity, particularly secondary types, in the Pila Spi Formation carbonates. Early dolomitisation also contributed to the development of fenestral porosity. In contrast, cementation, compaction, neomorphism, silicification, and pyritisation reduced porosity. Karstic fissures and pores are the main factors enhancing the aquifer potential of the formation, whereas iron oxidation negatively affects the groundwater quality. This study provides a comprehensive and quantitative framework linking diagenetic processes to porosity evolution, significantly improving the understanding of aquifer behaviour and groundwater quality in the Pila Spi Formation.
Accurate mapping of hydrothermal alteration zones is critical for improving the efficiency of porphyry copper exploration. In the Kuhpanj porphyry copper district (Kerman, Iran), distinguishing phyllic, argillic and propylitic alterations from surrounding lithologies using satellite data remains challenging due to spectral complexity and spatial heterogeneity. This study proposes an improved semantic segmentation framework for spaceborne hyperspectral imagery, exploiting 41 bands of PRISMA data to delineate alteration zones at the deposit scale. A modified U-net architecture was developed that employs a dual-path design for the concurrent extraction of spectral and spatial features: one branch processes pixel-wise spectra across the 41 bands, while the second branch captures local spatial context within 256 & times; 256 & times; 41 patches. The performance of the proposed network was benchmarked against a V-net architecture using a confusion-matrix-based evaluation. The proposed model achieved an F1-score of 86% while being trained on a limited labelled dataset, and it requires substantially fewer trainable parameters than the reference architecture, highlighting its efficiency for data-constrained exploration scenarios. The results demonstrate that the new dual-path U-net significantly enhances the reliability of alteration mapping from PRISMA hyperspectral data and provides a computationally efficient deep-learning solution for processing high-dimensional geoscientific imagery. This contribution extends current applications of convolutional neural networks in mineral exploration by introducing a tailored architecture that improves both accuracy and model compactness for hyperspectral semantic segmentation.
Narrow vein Au-Ag deposits have practical and academic relevance for mining operations research and geometallurgy. The restricted two-dimensional vein geometry is subject to inflexibility in the mining sequence and thus forces any feed imbalances into the metallurgical plant to be resolved through stockpiling and blending. The geometrical inflexibility simplifies the dynamic simulation of the mining system, allowing a decoupling of (1) the geospatial simulation of critical ore attributes from (2) the downstream operational decisions that govern the metallurgical process. Whereas sequential Gaussian simulation (SGS) is the most common geostatistical technique for conditional simulation of spatially distributed attributes, discrete rate simulation (DRS) is arguably the most basic approach to dynamic mass balance, capable of representing departures from stable metallurgical operating conditions and tallying the impact. Relevant impacts can include lost recoveries, lost throughput, and ineffective use of reagents such as cyanide, or combinations thereof. The current work is the first instance that directly combines SGS and DRS within a single framework, representing an industrially relevant context that is low-sulphidation epithermal gold-silver deposits. The framework is comparable to an inventory stockpile simulation, typical of a manufacturing context, except that the supply uncertainty is subject to geological complexity, e.g. a fault-laden paleo-phreatic surface separating overlying oxide ores from underlying sulphide ores, which complicates the downstream cyanidation process, as in the El Pe & ntilde;& oacute;n Mine (Chile). Operating policies can be formulated and parametrised within the framework and tested against geological scenarios that are based on drill samples taken from the workface, and considering critical geological features such as structural transitions in mineral assemblies. Sample computations demonstrate that refined stockpiling and blending can result in a 14% decrease in cyanide consumption during a demanding stage of the mine life, while maintaining other key performance indicators such as gold and silver recovery, and throughput.
Both arc-related and enriched-mantle rocks occur within the Paleoproterozoic Birimian terrane; however, the geological implications of this remain enigmatic. This study thus investigates the geological implications of this occurrence by integrating major and trace element data from the mafic suites of the Winneba Segment and published geochemical data from other Birimian belts in Ghana. The Winneba Segment mafic suites are dominantly subalkaline basalts, with minor basaltic andesite and andesite similar to the other Birimian belts. Geochemical features of the Winneba Segment mafic suites and the other belts characterised by negative Nb-Ta peaks, enriched large-ion lithophile element, light rare earth element, and depleted high-field strength element support formation in an arc setting through subduction-accretionary processes. They are characterised by La/Nb of 0.9-7.2, Ti/Zr of 24-154, moderate to high Nb/Yb, and high Th/Yb values. The low values are characteristic of arc-influenced magmas, whereas the spread to very high ratios might indicate magma-crust interaction during their evolution. A few mafic suites of the Winneba Segment and the Bui Belt exhibit an enriched-mantle character with positive Ta, Nb, and Ti anomalies. The new geochemical data for the mafic suites of the Winneba Segment, and previously published data from mafic suites in other Birimian belts in Ghana, reveal the presence of two distinct types of mafic suites: enriched- and arc-related. The arc-related mafic suites are proposed to be associated with subduction-related accretionary processes during the Rhyacian Eburnean orogeny, while the enriched-mantle signature may result from magma-crust interaction and possibly sediment/upper-crustal contamination.
Deep brines in the Qaidam Basin (QB, northern Tibetan Plateau) hold abundant K, Li, B, Br and Sr resources with great exploitation potential. Nevertheless, mechanisms controlling spatial enrichment heterogeneity of these valuable elements remain unclear, restricting efficient brine resource exploration and utilisation. This study systematically integrated hydrogeochemical parameters, multi-isotope (H-O-B-Li-He) signatures and temperature data acquired from 55 deep boreholes to reveal elemental differentiation laws and formation controlling factors of deep brines. Quantitative results show central basin brines yield average concentrations of 0.36-1.12 g/L K (avg = 0.73 g/L), 108-495 mg/L B (avg = 252 mg/L), 27-114 mg/L Li (avg = 90 mg/L), 38-83 mg/L Br (avg = 59 mg/L) and 142-381 mg/L Sr (avg = 245 mg/L), all distinctly lower than those in western brines. Western brine isotopic features (delta D-delta 18O patterns) reflect predominant water-rock interaction, while central brines experience combined water-rock reaction and evaporation concentration. Helium isotopes verify crustal fluid origin for central brines and mantle-derived magmatic fluid contribution in the western basin. High geothermal anomalies are exclusively identified in the Nanyishan-Dafengshan and Yahu-Hongsanhan anticlinal zones, which facilitate B and Li migration and accumulation. Lithologic properties at basin margins dominate Li/B ratio variation in central brines, whereas K, Br and Sr distribute evenly and are mainly regulated by lake depocentre migration. Geothermal condition, fluid source and sedimentary evolution jointly shape regional brine elemental discrepancy. Different fluid genesis models are confirmed between western and central basin brines. Distinct from prior research focusing on a single element or partial local area, this work clarifies the coupled control of fluid source, geothermal activity and depositional evolution on multi-element spatial heterogeneity across the whole basin. The quantitative dataset and genetic mechanism understanding offer practical guidance for targeted deep brine prospecting and comprehensive resource development in the QB.
Lithology identification is pivotal for the refined evaluation and efficient development of tight sandstone reservoirs. The second Member of the Taiyuan Formation in the Daniudi gas field is a typical tight sandstone reservoir characterised by complex lithology, primarily comprising quartz sandstone, lithic quartz sandstone, and lithic sandstone. These lithologies exhibit significant differences in petrophysical and gas-bearing properties. A major interpretation challenge is the presence of widespread high-gamma sandstones. These sandstones are often misidentified as mudstones in conventional log analysis, leading to underestimation of net sandstone and gas pay thicknesses. The primary objectives of this study are to accurately identify lithology and to precisely calculate the shale content for these high-gamma sandstones. The methodology integrates thin-section analysis, petrophysical laboratory data, and conventional well logs. The study systematically established the correspondence between mineral composition and log responses for different sandstone types. This led to the development of a sensitive log-curve identification method specifically for high-gamma sandstones. Furthermore, a multivariate fitting model was constructed to establish an improved shale content calculation method, effectively overcoming the limitations of traditional models. Software for automatic lithology identification and shale content calculation was developed and successfully applied to log data from over 30 wells in the field. The results demonstrate that the proposed method achieves high accuracy, with lithology identification conformity exceeding 90% and shale content calculation conformity exceeding 95%. This study provides crucial technical support for reservoir delineation and gas-water layer identification in the Daniudi gas field. It significantly enhances the precision and efficiency of log interpretation and offers a valuable reference for the evaluation of analogous complex tight sandstone reservoirs.
Previous studies on the coal-rock gas accumulation has largely emphasised geological characterisation and controlling condition of coal-bed buried below 2000 m, leaving a gap in understanding how gas accumulate in deep coal-rock (>2000 m). The enrichment of free gas in deep coal-rock reservoirs is different from the enrichment of adsorbed gas in coal-bed buried below 2000 m, and has relatively unique geological condition and distinct gas accumulation models. To fill this gap, low-temperature carbon dioxide adsorption, low-temperature nitrogen adsorption, mercury intrusion porosimetry, scanning electron microscopy, and 3D-CT-scan were carried out to characterise the pore structure and cleat of deep coal-rock reservoirs. The organic geochemical indicators, storage capacity and gas-bearing characteristics of deep coal-rock reservoirs have also been revealed. The deep coal-rock display a lustrous semi-dark to bright sheen, with both face and end cleats. The microscopic composition is dominated by vitrinite, with a variety of minerals interspersed with the organic components. The reflectance of the vitrinite is relatively high, reaching up to 1.65, indicating high maturity, typical of coking coal and lean coal. The deep coal-rocks exhibit a dual-porosity system, consisting of matrix pores and cleats. Micro-pores make up 84.8% of the deep coal-rock and serve as the primary reservoir space for adsorbed gas. Meso-pores make up the smallest proportion, at only 6.9%, while macro-pores average 8.3%. Natural fractures are rare in the deep coal-rock. In the matrix of the deep coal-rocks, open gas pores, pores from residual plant tissues, and inorganic mineral-related pores such as intercrystalline, intergranular, and intragranular pores can all be observed. The average conventional porosity is 5.35%, with relatively large variations in permeability. The gas content of the deep coal-rock ranges from 3.27 to 19.18 m(3)/t, with an average of 9.33 m(3)/t. The proportion of free gas is 18.1%, while adsorbed gas can account for up to 81.9%. The accumulation of deep coal-rock gas is controlled by three key factors: hydrocarbon generation conditions, reservoir conditions, and preservation conditions. The coal quality in Western Ordos Basin is slightly lower than that of the Eastern Ordos Basin, but the stability in the distribution of thick coal-rocks (average 8.56 m) provides a strong foundation for the accumulation of deep coal-rock gas. The reservoir and preservation conditions of deep coal-rock in the study area are comparable to those in the eastern basin, demonstrating significant exploration potential. The findings of this study are valuable for future exploration of coal-rock gas, as these findings will enhance the understanding of the petroleum systems in deep coal-rock.
Deep coal-rock intervals in the Ordos Basin host substantial unconventional gas resources but commonly pose severe drilling risks due to poor borehole integrity. This study integrates regional geological characterisation with engineering observations to characterise the geological and geomechanical attributes of deep coal-rocks from the Benxi-Shanxi formations and to develop a targeted drilling-fluid strategy for wellbore stability. Deep coal-rocks are generally characterised by high thermal maturity, complex mineral assemblages, well-developed cleats/fractures, low mechanical strength, and pronounced stress sensitivity. The primary reservoir space is provided by a pore-fracture system dominated by micropores and cleat/fracture networks, which also facilitates drilling-fluid invasion and mechanical degradation. This study propose that wellbore instability in these deep coal-rocks is mainly governed by a brittle-shear composite failure, driven by the coupled effects of chemical weakening associated with fluid invasion and localised stress concentration around the borehole. To mitigate collapse, a drilling-fluid system is designed and validated, emphasising suitable mud density, multi-stage plugging, and strong inhibition. Laboratory evaluations demonstrate that the combined action of key plugging agents (G314 and G308) with inhibitors effectively seals multi-scale fractures, suppresses clay hydration, and builds a resilient filter cake, thereby markedly improving wellbore stability. These results provide practical guidance and technical support for safe and efficient drilling in deep coal-rock reservoirs of the Ordos Basin.
This study presents a detailed mineralogical and crystallochemical characterisation of clay deposits from Mbengwi (Northwest Region, Cameroon) to evaluate their suitability for industrial applications. Three samples collected at depths of 10.7 m (BGW1), 8.8 m (BGW2) and 6.5 m (BGW3) were analysed using x-ray fluorescence, x-ray diffraction, Fourier-transform infrared spectroscopy (FTIR), thermogravimetric analysis and differential scanning calorimetry. Across all sampled depths, high-purity kaolinite consistently dominates the mineralogical composition (similar to 90%), with minor occurrences of illite (1.5%), quartz (3%), goethite (1.3%) and anatase (1.4%). The SiO2/Al2O3 ratio closely aligns with the theoretical value for ideal kaolinite (1.17). The absence of distinct crystalline iron-bearing phases suggests either isomorphic substitution of Fe3+ within the kaolinite lattice or the presence of poorly crystalline iron minerals. Crystallinity indices - including the Hinckley Index, the size of the coherent scattering domain (D), the slope ratio and the FTIR-derived P0 and P2 factors - indicate a progressive enhancement of structural order with increasing depth. Thermal analyses corroborate this trend: deeper samples exhibit higher dehydroxylation temperatures and sharper endothermic peaks, reflecting least defect density and high kaolinite purity. These findings highlight the superior crystallinity and purity of deeper kaolinitic layers, positioning Mbengwi clays as promising candidates for high-performance applications such as ceramics, paper, catalyst supports and polymer industries.
Sibagaon pegmatites in Northwest India demonstrate transition from barren granitic magmatism to LCT mineralization, offering geochemical insights to refine rare metal exploration models. Hosted in calc-silicate rocks, these pegmatites are highly fractionated, peraluminous, LCT-type, show syn- to post-collisional signatures and feature lepidolite (contain up to 2.34 w-t% Li2O) as primary Li- mineral, followed by elbaite to liddicoatite tourmalines. Geochemical markers distinguishing them from barren granites include low Nb/Ta ratios, REE tetrad effects, non-CHARAC behavior, and linear Li-F correlation. Lepidolite and tourmaline exhibit core to rim Li and F enrichment. Tourmalines with liddicoatite rims and feldspar replacement textures indicate late stage CaO rich fluid contamination. This study illustrates a continuum from fractional crystallization to magmatic-hydrothermal interaction with late Li-F fluid influx causing rare metal mineralization. These signatures with inferred resource of 91,295 tonnes at 0.673 wt-% Li2O provide a quantitative framework for identifying similar prospects in evolved collisional granitic systems.
Western Sichuan is located in a complex foreland thrust system, where intense multi-stage tectonic deformation makes hydrocarbon preservation a critical control on accumulation and exploration success. Focusing on the Middle Permian strata, this study aims to systematically evaluate hydrocarbon preservation conditions and clarify their spatial variability. Based on integrated seismic interpretation, formation water geochemistry, pressure data and regional geological and exploration information, a multi-indicator evaluation framework was established, incorporating tectonic deformation intensity (fault distance and fault development), exposed strata, caprock integrity and formation water characteristics. The results reveal a clear zonation of preservation conditions across western Sichuan. Near the Longmenshan fault front, dense faulting, severe caprock destruction and low-salinity NaHCO3-Na2SO4-type formation water indicate an open system with poor preservation. In the basin-mountain transition zone, fault activity weakens and partial caprock preservation remains, accompanied by moderate-salinity mixed NaHCO3-CaCl2 water, reflecting intermediate preservation. Towards the basin interior, structures become stable and closed, regional gypsum-mudstone caprocks are well developed, and high-salinity CaCl2-type brines dominate, indicating long-term sealed systems and favourable preservation. These conditions are confirmed by multiple high-yield gas discoveries, including the Pingluoba-1 well with a tested gas flow of 66.76 & times; 10(4) m(3)/d. The proposed multi-indicator evaluation method and preservation zonation provide a robust geological basis for optimising exploration strategies in complex foreland basins such as western Sichuan.
Accurate prediction of concealed water-bearing structures ahead of tunnel excavation is a critical challenge for ensuring construction safety, controlling project costs and maintaining schedules. Conventional geophysical exploration methods often fail to satisfy engineering requirements under complex geological conditions due to limited accuracy and low resolution. This study aims to address the bottleneck of insufficient detection accuracy in single geophysical methods. To achieve this goal, a high-precision three-dimensional (3D) geological advance prediction technical framework is constructed and validated. The method systematically integrates advanced wavelet-based signal filtering and denoising techniques, efficient two-dimensional inversion algorithms and 3D visualization imaging. Of particular importance is that this study utilizes magnetic prospecting data as a multi-physical field joint constraint. It performs collaborative inversion with Transient Electromagnetic Method (TEM) data to overcome the multi-solution nature of single physical field interpretation. Validation in an actual tunnel engineering project demonstrates outstanding predictive performance: the root mean square error (RMSE) is reduced to 8%, the correlation coefficient (R) reaches 0.92, the signal-to-noise ratio (SNR) achieves 30 dB and spatial resolution is improved by approximately 30% compared with conventional two-dimensional inversion methods. The research results indicate that the proposed method significantly enhances the accuracy, reliability and detailed resolution capability of water-rich structure detection. It successfully overcomes the precision limitations of traditional geological prediction techniques. The novelty of this study lies in establishing a complete high-precision technical system from signal processing to multi-physical field comprehensive inversion. This provides a more reliable scientific basis for the safe construction of tunnels under complex geological conditions and surpasses the traditional prediction model that relies on a single physical field.
