Search Results (278)

Lead and zinc mineralization have been documented in low-temperature Mississippi Valley type (MVT), Volcanogenic Massive Sulfide (VMS), and high-temperature porphyry and skarn ore deposits. These deposits are characterized by the precipitation of galena (PbS) and sphalerite (ZnS) from a saline hydrothermal fluid. The direct relationship between metal concentration and the total chloride of the fluid has been documented previously; however, the role of acidity has not been studied extensively. Experiments were conducted in René 41 cold-seal pressure vessels at temperatures of 200, 300, and 500 °C and a pressure of 100 MPa to provide better constraints on the formation of galena and sphalerite in hydrothermal systems spanning a range of fluid acidities (pH). The concentrations of Pb and Zn in the synthetic hydrothermal fluids were determined at galena and sphalerite saturation as a function of HCl and at a total chloride of 15 wt.% NaCl_eq.. Zn concentrations ranged from 1.7 (±0.3) × 10² µg/g at 200 °C and an HCl concentration of 2.28 × 10³ µg/g to 2.55 (±0.5) × 10³ µg/g at 500 °C and an HCl concentration of 3.40 × 10⁴ µg/g. Pb concentrations were 1.8 (±0.4) µg/g at 200 °C and a HCl of 2.28 × 10³ µg/g and increased to 7.93 (±1.5) × 10³ µg/g at 500 °C and a HCl concentration of 3.40 × 10⁴ µg/g. Zn/Pb mass ratios in the fluids at sphalerite and galena saturation decreased with increasing temperature. The experimental data demonstrate that the concentration of Pb and Zn in the fluid increase with both temperature and HCl concentration and, consequently, decrease with increasing pH. These results demonstrate that acidic fluids can transport substantially greater concentrations of Pb and Zn than neutral or basic fluids. Experimentally determined slopes of Pb and Zn concentrations as a function of HCl in the fluid provide empirical measurements of the apparent dependence of metal solubility on HCl at a constant total salinity. These results are consistent with Pb and Zn being transported predominantly as chloride-complexes under acidic, although the experiments do not directly determine aqueous metal speciation. Consequently, the experimentally determined HCl dependencies should be interpreted as empirical measures of apparent metal solubility rather than direct measurements of speciation or ligand coordination. The observed dependence of dissolved metal concentrations on HCl likely reflects the combined effects of chloride complexation, increasing HCl association with increasing temperature, non-ideal solution behavior, and changes in the distribution of dissolved chloride- and possibly sulfur-based complexes. Therefore, the neutralization of an acidic Pb- and Zn-bearing, chloride-rich hydrothermal fluid could produce substantial galena and sphalerite mineralization if sufficient reduced sulfur is available. In hydrothermal fluids depleted in reduced sulfur, H₂S must be supplied through sulfate reduction or by mixing with an H₂S-rich fluid to promote galena and sphalerite precipitation. Full article

In recent years, data-driven mineral prospectivity mapping (MPM) has become a key technical approach for delineating exploration targets. Nevertheless, two major challenges persist. First, sampling is often sparse and irregularly distributed, making it difficult to represent spatial relationships effectively. Second, many existing models implicitly assign equal importance to all geochemical elements. They also fail to jointly model heterogeneous elemental contributions and spatial neighborhood relationships. To address these issues, we propose the Spatial–Element Transformer (SETransformer), which integrates SHapley Additive exPlanations (SHAP)-derived element-importance attention bias with adaptive-bandwidth spatial-decay attention for data-driven MPM. We evaluate the proposed method using data from the Jiama porphyry–skarn Cu-polymetallic deposit in Tibet, China, within two a priori defined metallogenic feature subspaces: Mo-type and Cu-type. SETransformer is benchmarked against conventional machine learning models (Random Forest (RF), eXtreme Gradient Boosting (XGBoost), support vector machine (SVM)), and deep learning baselines (graph convolutional network (GCN) and TabNet). Model performance is assessed under two spatial validation schemes: a south–north hold-out validation and a five-fold spatial block cross-validation. Under both schemes, SETransformer achieves the best overall performance in the two subspaces. The predicted MPMs are consistent with regional geological evidence and exhibit clearer boundaries, providing a useful reference for subsequent target delineation in the study area. Full article

Iron ore mining is often assumed to pose a low soil-contamination risk because magnetite is dense and metal-poor. We tested this assumption around the Sokolov–Sarbai magnetite–skarn complex (Kostanay Region, Kazakhstan) by sampling soils at four settlements and a nearby background site, analyzing sixteen elements in pseudo-total and exchangeable forms, and comparing classical pollution indices with disaggregated US EPA health risk metrics on the same dataset. The two frameworks diverge sharply. Integrated indices (PLI, PERI) classify the area as low-risk, yet the child hazard index (US EPA cobalt reference dose) exceeds one at all four settlements, driven almost entirely by cobalt—a single, highly mobile element released from the late-stage sulfide paragenesis of the host skarn against an already cobalt-rich regional background. This relative result—cobalt as the dominant contributor and Rudny City as the most affected settlement—is robust to exposure-parameter variation and, at Rudny City and Konstantinovka, to unfavorable bioaccessibility assumptions. Carcinogenic risk stays within the acceptable range and reflects regional-background nickel and chromium rather than a mining increment. For single-element, regionally elevated contaminants, integrated indices can therefore understate a genuine child health hazard; adequate assessment requires mobile-fraction characterization and bioaccessibility-explicit risk computation. 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

Titanite is a widespread accessory mineral in magmatic, metamorphic, and hydrothermal systems and can incorporate trace elements that are sensitive to ore-forming processes. Although titanite trace-element chemistry has been widely applied to individual ore systems and deposit comparisons, its potential for supervised machine-learning-based discrimination across multiple ore deposit types remains less systematically explored. In this study, we compiled a literature-based LA-ICP-MS titanite trace-element dataset comprising 1679 analyses from five major ore deposit types: porphyry, skarn, iron oxide–apatite (IOA), iron oxide copper–gold (IOCG), and orogenic Au deposits. A common feature set of 21 trace elements, including REE, Y, Zr, Hf, Nb, Ta, Th, and U, was used to evaluate six supervised machine-learning algorithms: K-nearest neighbors, support vector machine, random forest, XGBoost, TabMap, and TabPFN. Two-dimensional element and element-ratio diagrams showed substantial overlap among deposit types, whereas machine-learning models better captured deposit-type-related multielement patterns in the compiled dataset. TabPFN achieved the highest stratified 5-fold cross-validation performance, with an accuracy of 0.957 ± 0.011 and a macro-F1 score of 0.944 ± 0.012, followed by TabMap and XGBoost. SHAP and TabMap-SHAP interpretations suggest that deposit classification is mainly associated with coupled variations in REE-Y, Eu, HFSE, and Th-U systematics rather than with a single diagnostic element. These results indicate that titanite trace-element compositions may provide a useful quantitative and interpretable approach for deposit-type discrimination within compiled geochemical datasets, while broader application requires expanded standardized datasets and independent validation samples. 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 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

The No. VI ore block of the Galinge skarn system in the Qimantagh metallogenic belt, East Kunlun, contains proximal Fe-oxide mineralization and distal Pb–Zn sulfide mineralization that are spatially zoned and locally overprinted along faults and interlayer fracture zones. To constrain the controls on Fe–Pb–Zn zonation and overprinting within this ore block, we integrated LA–ICP–MS zircon U–Pb dating, zircon Lu–Hf isotopes, whole-rock major and trace elements, and in situ trace elements of magnetite, pyrite, chalcopyrite, pyrrhotite, and arsenopyrite. Zircon U–Pb ages indicate two Indosinian intrusive pulses: an early granodiorite at 235.1 ± 0.51 Ma and a younger granodiorite–quartz diorite at 229.52 ± 0.46 Ma. Excluding the hydrothermally altered sample ZK26804-805, the intrusive rocks are metaluminous, medium- to high-K calc-alkaline I-type granitoids mainly derived from remelting of ancient crustal material, with a greater juvenile crustal or mantle contribution in the younger phase. Magnetite is generally Zn-rich and Pb-poor, whereas late pyrite and chalcopyrite are enriched in Pb, Ag, Cd, and Bi; local Sb–As anomalies in magnetite and arsenopyrite indicate late hydrothermal overprinting. The Fe and Pb–Zn mineralization is best interpreted as staged products of one multipulse magmatic–hydrothermal system controlled not only by intrusive pulses but also by inherited structural pathways, host-rock reactivity, and evolving redox-sulfidation conditions. The interpretation of Sb–As enrichment in magnetite is therefore used cautiously because these elements may occur as lattice substitutions and/or micro- to nano-inclusions introduced or modified during retrograde alteration. Full article

The Tonglushan ore field is an important component of the polymetallic mineralization belt in the middle and lower reaches of the Yangtze River in China. The skarn-type Cu, Fe, Au, and Mo molybdenum deposits are mainly developed in the contact zone between the rock mass and the strata, as well as in the contact zone between residual and capturing bodies in the rock body. The distribution of ore bodies is controlled by faults and strata, but there is a lack of large-scale geophysical information on the contact relationship between the ore-forming geological body and the host rock and on the deep spatial morphology of the ore-forming structure and intrusion rock. The study uses the JS-WEM2 wide-field electromagnetic instrument and the RS230 spectrometer to conduct the ground frequency domain electromagnetic and radiometric spectrometry measurements on four profiles. The measurement results indicate that the fault distribution in the Tonglushan ore field is predominantly in the NW-trending and NE-trending directions. The NW-trending Tonglushan–Lijiashan fault (F2) is a steeply dipping fault; the NE-trending faults are minor, with steep dips, generally extending no deeper than −1000 m. The Tonglushan stock exhibits the northeastward uplift, characterized by southward overlap and southeastward dip. The deep resistivity is greater than 3000 Ω·m, while the resistivity below −1000 m is less than 2000 Ω·m due to the fault influence. The ore bodies are mainly distributed along the contact zones where variations in the occurrence of the rock intersect with the strata. On resistivity profiles, these zones show the gradient variation in resistivity and the distorted shape of the resistivity contour line. The radioactive element contents of wall rock above the ore bodies are characterized by high U, high Th, and low K. The Wide-Field Electromagnetic Method (WFEM) can effectively detect the distribution and morphology of rocks and faults, and combined with the radioactive characteristics of geological bodies, it can effectively identify concealed faults and the favorable mineralization target areas. Novelty: The study combines the WFEM with radiometric measurements to reduce uncertainty in exploration compared to using only one method. It improves the detection accuracy and target identification ability of deep hidden ore bodies, providing the new technical method for deep mineral exploration in complex structural areas. Full article

Early-age strength development and carbon emissions represent specific operational constraints in underground cemented tailings backfill (CTB) operations. A pH and ionic pre-conditioning-assisted CO₂ mineralization process was evaluated for carbonate-rich cemented tailings backfill designed to improve early UCS while retaining measurable CO₂ uptake through systematic process control and optimization. Skarn-type tailings (CaO 16.74 wt%, total carbonates 34.7 wt%) were subjected to screening under nominal pH and ionic pre-conditioning treatments (4.0–11.5), CO₂ pressure (0–0.5 MPa), cement-to-tailings ratio (1:3–1:12), and slurry concentration (66–78%). Strength evolution (1–28 d), mineralization products were characterized using TGA as the primary CO₂-uptake method, with XRD used for semi-quantitative phase-trend assessment, scanning electron microscopy (SEM), electron backscatter diffraction (EBSD), transmission electron microscopy (TEM) with selected-area electron diffraction (SAED), X-ray computed tomography (CT), and nuclear magnetic resonance (NMR). Under optimal conditions (pH 8.5, 0.3 MPa CO₂ pressure, 48 h mineralization, 72–74% solids), mineralized specimens achieved 2-day uniaxial compressive strength equivalent to 1.47-times the 3-day control strength (p < 0.01), with peak net CO₂ sequestration of 37.1 g/kg. EBSD analysis of 347 grain boundaries and TEM-SAED examination of multiple foil sections supported the occurrence of syntaxial calcite overgrowth on primary carbonate debris as a major interfacial transition zone strengthening mechanism. Interconnected pore cluster volume decreased by 70.6%; Zn²⁺ and Pb²⁺ leaching decreased by 67.2% and 71.8%, respectively. A shrinking-core kinetics-Ryshkewitch model with pH-dependent correction functions predicted 3-day strength with acceptable accuracy for TW-A and TW-B, whereas TW-C showed a −27.3% deviation, identifying acidic and sulfate-rich wastewater as a boundary condition outside the reliable model domain. Field coring at −500 m depth provided pilot-scale evidence that a 23 mm mineralized shell was consistent with localized reduction of shallow exposed-face instability risk during the early free-standing period. Overall, the pH and ionic pre-conditioning-assisted CO₂ mineralization process is proposed as a laboratory-supported and field-informed screening framework for simultaneous early-strength enhancement and partial carbon sequestration in carbonate-rich cemented tailings systems. The resulting models and parameter guidance should be interpreted as preliminary design tools requiring further factorial optimization and long-term field validation before full site-specific deployment. Full article

The Huanggangliang area in Inner Mongolia is a major fluorite and polymetallic ore district in China. Its skarn-type deposit yields rare color-change fluorite, yet the coloration and photochromic mechanisms remain poorly studied. Five faceted samples were characterized by conventional gemological tests, EDXRF, UV-Vis, Raman, PL, TL, and FTIR to determine their composition, spectral features, and defects. The results indicate two distinct color-forming mechanisms. Group I is dominated by f-f transitions of rare-earth elements with color-center synergy, showing a strong gray-blue to blue-violet color change and a characteristic absorption peak at ~580 nm in the UV-Vis spectrum. Group II is dominated by high-concentration irradiated color centers. Its deep blue-violet color and weak color change are attributed to colloidal induced by long-term endogenous α, β, and γ irradiation from radioactive Th. The lack of additional Raman peaks and a broad UV-Vis absorption peak at ~595 nm, along with multiple UV color-center peaks, weak fluorescence, and thermoluminescence, all confirm the presence of high-concentration electron traps. This study establishes the composition–spectrum–color relationship, reveals the control of ore-fluid evolution on mechanism differentiation, and provides a scientific basis for identifying and analyzing color-change fluorite. Full article

The Djurkovo and Govedarnika deposits represent hydrothermal Pb-Zn systems spatially associated with the Eocene–Oligocene tectono-magmatic evolution of the Rhodope Metamorphic Complex. This study presents new mineralogical and geochemical data for galena, sphalerite, pyrite, and chalcopyrite obtained by electron probe microanalysis (EPMA) and LA-ICP-MS in order to evaluate the compositional variations of sulphides among the vein and metasomatic mineralization types and between the two deposits. The analysed sulphides exhibit distinct compositional signatures reflecting the different mineralization stages and hydrothermal environments. Sphalerite from the Govedarnika metasomatic ores is enriched in Mn (up to 5200 ppm), Fe (up to 5.13 wt.%) and Co due to interaction with Mn-rich skarn assemblages, whereas Djurkovo sphalerite shows elevated Cd (up to 3000 ppm), In and Hg concentrations. Trace-element systematics indicate coupled Fe-Mn incorporation, competitive Cd-Fe substitution and local re-equilibration processes associated with “chalcopyrite disease” textures. Late pyrite from the quartz-carbonate stage is enriched in As (up to 3.87 wt.%), Au (up to 78 ppm), Ag, Se, Sb and Tl, with positive Au-As and Au-Ag correlations suggesting invisible gold and possible submicroscopic precious-metal inclusions. The obtained data demonstrate prolonged hydrothermal evolution and highlight the potential role of the studied sulphides as concentrators of economically important elements. Full article

This study presents the first detailed mineralogical characterization of rare earth element (REE) enrichment (up to 1.39 wt% TREO (total rare earth oxide)) within the regolith overlying the Doradilla tin-skarn prospect, northern New South Wales, Australia. The REE mineralogy was investigated using petrography, field-emission scanning electron microscopy (FE-SEM), electron microprobe analysis (EPMA), micro-X-ray fluorescence (µ-XRF) elemental mapping, and laser Raman spectroscopy. Hydrated REE phosphate minerals are identified as the dominant REE hosts within the regolith. Raman spectroscopy confirms the presence of water in both rhabdophane and churchite. Three compositionally distinct rhabdophane populations are identified, including one La-dominant and two Y-rich groups, whereas churchite-(Y) represents the only HREE-enriched phase identified. The predominance of hydrated REE phosphates within the regolith highlights the importance of secondary phosphate minerals as major REE hosts within the Doradilla profile. This study emphasizes the need for detailed mineral characterization when studying REEs in previously undescribed settings. Furthermore, the results demonstrate that regolith developed over tin-skarn protoliths may host compositionally diverse and REE-enriched phosphate assemblages. With growing global demand for REEs, a greater understanding of REE mineralization in underexplored geological settings is increasingly important. Full article

The Nam Xan gold deposit is located in the central Truong Son Fold Belt of Laos. It is a newly identified distal intrusion-related gold system (IRGS) in a continental arc setting. This study uses whole-rock geochemistry, Pb and S isotope systematics, and mineral-scale analyses to trace magmatic evolution and ore-forming processes. Whole-rock data indicate that the associated intrusive suite is a calc-alkaline volcanic-arc granite (VAG) series, derived from a subduction-modified mantle source with notable crustal contributions. Pb isotopes reveal mixing arrays rather than true isochrons. Monte Carlo modeling shows binary mantle–crust mixing for igneous rocks and ternary mixing with an additional radiogenic component in ore samples, indicating enhanced fluid–rock interaction during mineralization. Sulfur isotope data show a shift from magmatic sulfur (δ³⁴S ≈ −5‰) in early skarn-stage pyrite to heavier values (δ³⁴S ≈ +6‰) in gold-bearing stages, reflecting fluid evolution driven by cooling and redox changes. Mineral chemistry data demonstrate that gold is present both as invisible gold within arsenian pyrite and as free gold in late-stage fractures. Strong correlations between Au and As, along with elevated Co/Ni ratios and enrichments in Bi, W, and F, collectively support a magmatic-hydrothermal origin. These findings define a three-stage mineralization process: an initial phase involving high-temperature magmatic fluids, a main stage characterized by sulfidation and gold deposition, and a final stage marked by polymetallic overprinting. The Nam Xan deposit is therefore interpreted as the distal manifestation of a Permian arc-related magmatic system in which magmatic fluids migrated along structural conduits and precipitated gold through interaction with carbonate host rocks. The identification of these intrusions in the distal IRGS at Nam Xan informs regional exploration models in the Truong Son Fold Belt, demonstrating the potential of carbonate platforms near Permian intrusions for future mineral exploration. Full article

The Shizui Cu–Pb–Zn deposit is located in central Jilin Province. It sits at the tectonic junction between the eastern Xing’an–Mongolia Orogenic Belt (XMOB) and the northeastern North China Craton (NCC). This is the first discovered Paleozoic Cu-polymetallic deposit in the region. Our study combines detailed geological investigation with systematic fluid inclusion analysis. We analyzed samples from four distinct paragenetic stages. Analytical methods include microthermometry, laser Raman spectroscopy, and hydrogen-oxygen isotope analysis. These data constrain the source, evolution, and precipitation mechanisms of the ore-forming fluids. The results delineate a clear evolutionary path: the ore-forming fluid originated as a high-temperature (346–437 °C), high-salinity (up to 51.68 wt.% NaCl equiv.) NaCl–H₂O–CO₂ system during the early quartz-sulfide stage (Stage I, Quartz ± Arsenopyrite ± Pyrite Stage), as evidenced by the coeval presence of high-salinity S-type and CO₂-rich C-type inclusions, indicating fluid immiscibility. The fluid then evolved into a boiling, medium temperature to high temperature (262–355 °C), high-salinity NaCl–H₂O system during the later part of early quartz-sulfide stage (Stage II, Quartz-Cu Polymetallic Sulfide Stage), a transition marked by the common coexistence of liquid-rich (L-type) and vapor-rich (V-type) inclusions with similar homogenization temperatures. This phase separation (boiling) served as the primary trigger for the massive deposition of chalcopyrite, arsenopyrite, and pyrite. Subsequently, the system cooled and diluted, transforming into a medium- to low-temperature (182–275 °C), low-salinity, partially homogeneous NaCl–H₂O system in the late quartz-sulfide stage (Stage III, Quartz-Pb-Zn Polymetallic Sulfide Stage). Finally, in the quartz-carbonate stage (Stage IV, Quartz-Carbonate Stage), the fluid temperature further decreased, resulting in a low-temperature (128–211 °C), low-salinity, homogeneous NaCl–H₂O system. Hydrogen-oxygen isotope data show that the calculated δ¹⁸O_H2O values decreased from +6.6‰ to +6.7‰ in Stage I to +3.4‰ to +3.9‰ in Stage II, and further to −0.4‰ in Stage III, while the δD values shifted from −91.6‰ to −90.6‰, to −94.4‰ to −94.2‰, and finally to −95.7‰. This trend indicates that the initial magmatic fluid progressively mixed with meteoric water. The geological characteristics, spatial association with Hercynian biotite monzogranite, developed skarn alteration, and the documented fluid evolution trajectory collectively affirm that the Shizui deposit is a typical skarn-type system. The deposit shares significant similarities in mineralization conditions, age, and tectonic setting with the skarn-type Tianbaoshan Pb–Zn–Cu–Mo deposits in the western segment of the XarMoron–Changchun Metallogenic Belt (XCMB). This correlation strongly suggests that the Paleozoic XCMB extends eastward and holds considerable potential for the discovery of late Paleozoic skarn-type Cu-polymetallic deposits in its eastern part. Full article