Search Results (48)

The close spatial and genetic coexistence of Skarn-type and Hydrothermal Vein-type Pb-Zn deposits in the Shanghulin area, Inner Mongolia, poses a significant challenge to conventional “ undifferentiated” prediction models. This study aims to decouple these distinct metallogenic patterns using a data-driven, “type-specific modeling” strategy, establishing separate prediction models for Skarn-type and Hydrothermal Vein-type mineralization. Our workflow first employs Lasso–RFECV for rigorous pre-screening of over 60 geoscience features to identify the optimal predictive subset. Subsequently, an XGBoost model is trained on these selected features, and the SHAP framework is applied to interpret the geological significance of its decision logic. The results confirm two distinct indicator systems. (1) The Skarn-type model is controlled by spatial proximity to a heat source, heavily relying on Distance_to_Volcano and high-temperature indicators (CLR_Mo, CLR_W, CLR_Mn). (2) The Hydrothermal Vein-type model is “chemical fingerprint-driven”, prioritizing CLR_Y and identifying a complex “leaching-enrichment” pattern: mineralization requires simultaneous wall-rock leaching (low CLR_Al₂O₃, low CLR_Y) and specific metal enrichment (high CLR_Co, high CLR_Zn). This study confirms the controlling factors: Skarn-type deposits are governed by magmatic proximity, whereas Hydrothermal Vein-type deposits are defined by specific alteration geochemical signatures. The proposed “Lasso–RFECV → XGBoost → SHAP” workflow successfully decouples these independent, geologically meaningful prospectivity models from complex data, offering a new paradigm for precise exploration. Full article

The Southwestern Fujian Region is one of the important Fe polymetallic metallogenic belts in China. The Makeng-Yangshan Fe skarn sub-belt within it contains several deposits that share a similar geological setting, mineralization age, and genetic type, yet exhibit significant differences in metal endowment. To investigate the poorly constrained factors responsible for these differences, this paper focused on the mineral chemistry of garnets associated with magnetite from the Makeng, Luoyang, and Yangshan Fe deposits within the sub-belt, employing in situ laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) for trace element analysis. Our results reveal that garnet from all three deposits are andradite-dominated and features a chondrite-normalized REE fractionation pattern exhibiting enrichment in LREE relative to HREE, indicating crystallization from unified, mildly acidic fluids under high oxygen fugacity (f_O2) conditions. However, both the Makeng and Luoyang garnets showed a strong positive Eu anomaly, whereas the Yangshan garnets displayed the weakest Eu anomaly among the three deposits, which can likely be attributed to the highest f_O2 environment of the Yangshan deposit. Furthermore, garnet Y/Ho ratios and Y-ΣREE correlations demonstrate that the Makeng and Luoyang garnets crystallized in an open fluid system that were primarily of magmatic-hydrothermal origin with substantial external fluid (e.g., meteoric water) involvement, whereas the Yangshan garnet reflects a relatively closed fluid system that was predominantly of magmatic-hydrothermal origin with limited external fluid input. These geochemical differences have direct implications for exploration: the open-system Makeng deposit holds promise for Mo-W-Sn mineralization, as does the Luoyang deposit for W-Sn, whereas the closed-system Yangshan shows little potential for these metals. In addition, this study reveals that Pb and Zn concentrations in garnet are not reliable exploration indicators. Overall, these findings provide important mineralogical constraints on the factors controlling deposit scale and metal associations, thereby enhancing the understanding of regional metallogeny and guiding future mineral exploration. Full article

The Baijianshan deposit is the sole skarn Zn-Cu polymetallic deposit in the Xiaoshitouquan ore field, Xinjiang, China. Its ore genesis remains controversial, which hinders understanding of the relationship between skarn-type Zn-Cu and adjacent epithermal Ag-Cu-Pb-Zn mineralization and consequently impedes further regional exploration. LA-ICP-MS U-Pb dating on zircons from the granite and granite porphyry from the mining area yielded ages of 311 ± 1.7 Ma and 312 ± 1.6 Ma, respectively. The corresponding zircon ε_Hf(t) values and T_DM ages are 8.7–9.9 and 624–555 Ma for the granite, and 7.2–9.9 and 673–552 Ma for the granite porphyry. These granites are metaluminous, high-K calc-alkaline I-type granites, with high LREE/HREE ratios (4.92–9.03) and pronounced negative Eu anomalies. They are enriched in K, Th, U, Zr, and Hf, with significant depletions in Sr, P, and Ti. Combined geological and geochemical evidence indicate that these Late Carboniferous granites were derived from the juvenile crustal and formed in subduction-related back basin. Two-phase aqueous inclusions in the ore-bearing quartz and calcite have homogenization temperatures ranging from 117 to 207 °C and 112 to 160 °C, respectively, with the salinities in the ranges of 0.18~7.17 and 0.53~5.26 wt% NaCl eq. The S and Pb isotopic compositions of sulfides in the ores indicate that the ore-forming metals were sourced from the medium-acidic magmatite. The δ¹⁸O_H2O and δD_H2O values of hydrothermal fluids range from −6.97% to −5.84% and −106.8% to −99.6%, respectively, suggesting that the ore-forming fluids originated from the mixing of magmatic and meteoric water. Fluid mixing and corresponding conductive cooling were identified as the principal mechanism triggering the metallic mineral precipitation. The Baijianshan skarn Zn-Cu polymetallic deposit shares contemporaneous magmatic-mineralization ages and analogous material sources with the epithermal polymetallic deposits in the Xiaoshitouquan ore field, collectively constituting a unified skarn-epithermal metallogenic system. This hypothesis indicates that the deep parts of the epithermal deposits within the Yamansu volcanic rocks possess potential for exploring the porphyry-skarn-type deposits. Full article

Although skarn-type deposits represent significant hosts for Co resources, the distribution patterns and enrichment mechanisms of associated Co resources within these deposits have not been systematically investigated. This study summarizes relevant data on Co resources from representative skarn-type deposits in China to comparatively reveal the grade and reserve characteristics, spatiotemporal distribution patterns, and coupled enrichment mechanisms of Co across three principal skarn mineralization subtypes: iron-, copper-, and lead–zinc polymetallic-dominated deposits. Studies demonstrate that Fe-dominated skarn-type cobalt deposits exhibit widespread distribution, high Co grades (100–2000 ppm), and abundant Co reserves (4000–32,000 t), demonstrating significantly superior Co resource potential compared to Cu-dominated (Co grades: 20–200 ppm, Co reserves: 3000–10,000 t) and Pb-Zn polymetallic-dominated (Co grades: 140–853 ppm, Co reserves: approximately 3000 t) subtypes. In these skarn-type cobalt deposits, cobalt is mainly hosted in sulfide minerals. Influenced by tectonic settings, magmatic activity, and hydrothermal fluid evolution, associated Co resources in these skarn-type deposits exhibit both regional zonation and stage-specific differential enrichment patterns. In the formation of skarn-type cobalt deposits, mantle-derived magmas play a critical role in the pre-enrichment of Co. The injection of mafic magmas, assimilation of evaporite sequences, and the dissolution–reprecipitation mechanism of hydrothermal fluids collectively promote the re-enrichment of Co during magmatic evolution. These findings provide a theoretical foundation for targeted exploration, sustainable development, and comprehensive utilization of associated Co resources in skarn-type deposits. Full article

The Xulaojiugou Pb–Zn deposit, situated in the eastern Xing’an-Mongolia Orogenic Belt (XMOB), represents a medium-scale Pb–Zn deposit in central Heilongjiang Province, NE China. The mineralization occurs mainly near the contact zone of porphyritic biotite granite, medium-grained monzogranite, and marble in the Early Cambrian Qianshan Formation. Orebodies exhibit typical skarn characteristics and are structurally controlled by NE trending faults. To constrain the metallogenic age, ore-forming processes, and sources of ore-forming materials, we conducted integrated geochemical analyses, Re–Os isotope dating, in situ sulfur isotope analysis, and trace element analysis. Five molybdenite samples provided a Re–Os isochron age of 184.6 ± 3.0 Ma, indicating Early Jurassic mineralization. In situ δ³⁴S values from 20 sphalerite and 9 galena samples ranged from 5.31‰ to 5.83‰, suggesting derivation of sulfur from a deep magmatic source. Trace element analysis of 42 spots from three sphalerite samples revealed formation temperatures of 248–262 °C, which are consistent with mesothermal conditions. Integrated with regional tectonic evolution, the Xulaojiugou deposit is genetically linked to medium-grained monzogranite emplacement and represents a typical skarn polymetallic deposit, which is genetically associated with the regional porphyry–skarn metallogenic system that developed during the Early Yanshanian (Jurassic) tectonic–magmatic event and was driven by the subduction of the Paleo-Pacific plate. Full article

Numerous skarn-type Sn and hydrothermal vein-type Pb–Zn–Ag deposits occur in the northern Yidun Terrane, China. The Gongjuelong skarn Sn polymetallic deposit, adjacent to the Haizishan granite, is situated in the central region of Yidun Terrane. The genesis of the Gongjuelong Sn deposit and its relationship with the adjacent Pb–Zn–Ag deposits remains controversial. The ore-forming process can be divided into three stages: the prograde stage (I), marked by the formation of garnet and pyroxene; the retrograde stage (II), which includes the epidote–actinolite sub-stage (II-1) and the quartz-cassiterite sub-stage (II-2); and the sulfide stage (III), consisting of the chalcopyrite–pyrrhotite sub-stage (III-1) and the arsenopyrite–sphalerite sub-stage (III-2). Two types of garnet (Grt-I and Grt-II) have been identified in stage I and both belong to the grossular–andradite solid solution. Grt-II (Gro_52-73And_25-45Spe+Pyr+Alm_2-3) contains slightly more Fe than Grt-I (Gro_64-76And_20-28Spe+Pyr+Alm_2-10). Grt-I is enriched in heavy rare-earth elements (HREEs) and depleted in light rare-earth elements (LREEs), whereas Grt-II is enriched in LREEs and depleted in HREEs. Grt-I has higher U contents and lower Th/U ratios than those of Grt II, indicating a lower oxygen fugacity for the earlier skarn alteration. In contrast to Grt-I, Grt-II shows a more significant negative Eu anomaly along with lower LREEs/HREEs. Therefore, Grt-I and Grt-II likely formed under mildly acidic and near-neutral conditions, respectively. The W (350–3015 ppm) and Fe (235–3740 ppm) contents and Zr/Hf ratios (18.7–49.4) of cassiterite from Gongjuelong are similar to those of cassiterite from the granite-related Sn deposits, as well as the Xiasai hydrothermal vein-type Pb–Zn–Ag deposit in the northern Yidun Terrane. The Ti/Ge ratio (0.06–1.13) and P contents (13.9–173 ppm) of quartz are also similar to those from the Xiasai Pb–Zn–Ag deposit, both of which resemble those of skarn-type deposits and Sn-associated quartz. Furthermore, the Ti/Zr ratio (average 33.2) of cassiterite at Gongjuelong are much higher than that of cassiterite at Xiasai (average 3.7), indicating that the Pb–Zn–Ag veins could represent the distal product of the “parent” granite. On the basis of combined evidence from geology, geochemistry, and published geochronology data, we propose that the proximal skarn-type Sn deposits and distal hydrothermal vein-type Pb–Zn–Ag±Sn deposits in the northern Yidun Terrane constitute an integrated ore system, which is genetically related to the late Cretaceous highly fractionated granites. This proposed hypothesis highlights the potential prospecting of Sn mineralization beneath the hydrothermal Pb–Zn–Ag veins, as well as the hydrothermal Pb–Zn–Ag veins controlled by faults/fractures within the strata around the Sn deposits and highly fractionated granites. Full article

The Early Cretaceous Halasheng deposit, located in the southern Erguna Block, is an intermediate sulfidation epithermal Ag-Pb-Zn deposit in the Derbugan metallogenic belt. The Halasheng deposit comprises both proximal skarn mineralization and distal hydrothermal vein-type Pb-Zn-Ag mineralization, which can be further divided into three stages represented by Fe-As-S, Pb-Zn-Cu-Fe-S, and Ag-Pb-Zn-Sb-S element associations. The main ore minerals in the Halasheng deposit include galena, sphalerite, pyrite, arsenopyrite, chalcopyrite, bournonite, falkmanite, and argentiferous minerals. Visible silver in the form of independent argentiferous minerals, mainly including freibergite, polybasite, stromeyerite, pyrargyrite, acanthite, and native silver, is the major type of silver occurring in the Halasheng district. Fluid inclusion studies of sphalerite and quartz from different mineralization stages revealed that skarn mineralization has the relatively highest homogenization temperature (322~398 °C), while in the vein-type hydrothermal mineralization stage, the homogenization temperature has a declining trend from the early stage to late stage (from 300~350 °C to 145~236 °C). In the whole mineralization process, the salinity of ore-forming fluids is almost constant at a relatively high level (10.5~21.9 wt% NaCl). Fluid cooling, or fluid–wallrock reaction, is supposed to be the major cause of metal precipitation in the Halasheng deposit. Through an analogy with the typical Ag-Pb-Zn deposits in the Derbugan metallogenic belt, it is suggested that the discovered orebodies in the Halasheng deposit likely belong to the shallow part of the epithermal system, and there is high potential to discover Zn, Cu-Zn orebodies, and even porphyry Mo-Cu mineralization. In terms of regional ore prospecting, Early Cretaceous intermediate-acid intrusions have the potential to form related Ag-Pb-Zn deposits and should receive special attention. Furthermore, places where Lower Cambrian marbles are exposed or concealed are favorable settings for skarn mineralization. Full article

The large-scale vein-type Zn-Pb-Ag deposit in the Eastern Qinling Orogen (EQO) has sparked a long-standing debate over whether magmatism or metamorphism was the primary control or factor in its formation. Among the region’s vein-type deposits, the large-sized Bailugou deposit offers a unique opportunity to study this style of mineralization. Similar to other deposits in the area, the vein-type orebodies of the Bailugou deposit are hosted in dolomitic marbles (carbonate–shale–chert association, CSC) of the Mesoproterozoic Guandaokou Group. Faults control the distribution of the Bailugou deposit but do not show apparent spatial links to the regional Yanshanian granitic porphyry. This study conducted comprehensive H–O–C–S–Pb isotopic analyses to constrain the sources of the ore-forming metals and metal endowments of the Bailugou deposit. The δ³⁴S_CDT values of sulfides range from 1.1‰ to 9.1‰ with an average of 4.0‰, indicating that the sulfur generated from homogenization during the high-temperature source acted on host sediments. The Pb isotopic compositions obtained from 31 sulfide samples reveal that the lead originated from the host sediments rather than from the Mesozoic granitic intrusions. The results indicate that the metals for the Bailugou deposit were jointly sourced from host sediments of the Mid-Late Proterozoic Meiyaogou Fm. and the Nannihu Fm. of the Luanchuan Group and Guandaokou Group, as well as lower crust and mantle materials. The isotopic composition of carbon, hydrogen, and oxygen collectively indicate that the metallogenic constituents of the Bailugou deposit were contributed by ore-bearing surrounding rocks, lower crust, and mantle materials. In summary, the study presents a composite geologic-metallogenic model suggesting that the Bailugou mineral system, along with other lead-zinc-silver deposits, porphyry-skarn molybdenum-tungsten deposits, and the small granitic intrusions in the Luanchuan area, are all products of contemporaneous hydrothermal diagenetic mineralization. This mineralization event transpired during a continental collision regime between the Yangtze and the North China Block (including syn- to post-collisional settings), particularly during the transition from collisional compression to extension around 140 Ma. The Bailugou lead-zinc-silver mineralization resembles an orogenic-type deposit formed by metamorphic fluid during the Yanshanian Orogeny. Full article

The newly delineated Xipu Dome, located in the central North Himalayan Gneiss Dome (NHGD), exhibits a significant spatiotemporal relationship with Himalayan polymetallic mineralization. Based on field geological surveys and geochronological analyses, this study provides a comprehensive assessment of the lithological assemblage, tectonic deformation, and metallogenic processes of the Xipu Dome. The findings reveal a three-tiered structure: the core consists of early Paleozoic granitic gneiss (523 Ma) and Miocene leucogranite (13.5 Ma), overlain by a cover of low-grade metamorphic or unmetamorphosed sedimentary rocks, and a detachment zone composed of heavily deformed schists and phyllites. The Xipu Dome underwent three phases of tectonic deformation: a southward thrust caused by continental collision, northward extensional activity driven by the South Tibet Detachment System (STDS), and gravitational collapse and downslope sliding following the emplacement of the dome. Two types of mineralization were identified: structural hydrothermal Au-Cu polymetallic deposits related to detachment and skarn-type Cu-Ag polymetallic deposits associated with leucogranite intrusion. This study enhances the understanding of the spatial distribution and metallogenic potential within the Himalayan Be-Sn rare metal-Pb-Zn-Sb-Au belt, offering a valuable direction for strategic mineral exploration in the Tethyan Himalaya (TH). Full article

In the Huanggangliang–Ganzhuermiao metallogenic belt in the southern Great Xing’an Range, the Haobugao Pb–Zn deposit is the most widespread skarn-type polymetallic deposit. The observed mineralization processes in this area are closely associated with both magmatic and tectonic activity. The zircon U–Pb ages of two granitoid phases are 134.0 ± 0.6 Ma and 133.4 ± 0.9 Ma (Early Cretaceous). High SiO₂ content (average mass fractions of 77.98 wt.% and 73.25 wt.%), high alkalinity (average mass fractions of 6.19 wt.% and 8.78 wt.%), and low CaO levels (average mass fractions of 0.16 wt.% and 0.12 wt.%) are characteristic of these rocks. They are also enriched in high-field-strength elements (HFSEs) (Th, U, Ta, Zr, Hf, etc.) and depleted in large ion lithophile elements (LILEs) (Ba, Sr, etc.). Furthermore, the Nb/Ta ratios (7.80~8.82, 10.00~10.83) point to a crustal origin of the magma. The zircon Hf isotopic compositions suggest that the melting of young crust derived from Meso-Neoproterozoic and Neoproterozoic depleted mantle gave rise to the magma in these granite porphyries. These rocks formed in an extensional environment driven by the subduction and retreat of the Paleo-Pacific plate during the Early Cretaceous. Full article

The giant Changba-Lijiagou (Ch-L) Pb-Zn deposit is in the northeast part of the Xicheng ore cluster, Western Qinling Orogen. The ore genesis remains controversial; it could be either a sedimentary exhalative genetic type or an epigenetic hydrothermal genetic type. Here, in situ titanite U-Pb dating for the two kinds of titanite is presented, yielding ages of 212.8 ± 3.0 Ma in the mineralized skarn ore and 214.6 ± 5.1 Ma in the host rock. These ages conform to the previously reported magmatic zircon age (229–211 Ma) based on the in situ zircon U-Pb dating of plutons in this district and the time of large-scale magmatic–hydrothermal activities in Western Qinling Orogen (229–209 Ma). Titanites occurring in mineralized skarn and those that are calcite-hosted are similar to hydrothermal-origin titanites in major element characteristics. The Eu anomalies in the two types of titanite record oxidizing conditions during the mineralization process. A mineral assemblage of garnet, pyroxene, riebeckite, biotite, and potash feldspar, replacing the albite, is well-developed in the deposit. The mineralogical and geochronological characteristics indicate that the Ch-L Pb-Zn deposit is a distal skarn deposit and the result of intensive tectonomagmatic processes in the Xicheng ore cluster during the process of the Late Triassic orogeny. Full article

As challenges in precious and base metal exploration intensify due to the diminishing availability of high-grade ore deposits, rising demand, energy costs, and stricter regulations towards net-zero carbon activities, advanced techniques to enhance exploration efficiency are becoming increasingly critical. This study demonstrates the effectiveness of quantitative X-ray diffraction (QXRD) with Rietveld refinement, coupled with multivariate statistical analysis (including agglomerative hierarchical clustering, principal component analysis, and fuzzy analysis), in characterizing the complex mineralogy of strata-bound volcanic-associated limestone-skarn Zn-Pb-Ag-(Cu-Au)-type sulphide deposits (SVALS). Focusing on 113 coarse rejects from the Gumsberg project located in the Bergslagen mining district in central Sweden, the research identified five distinct mineralogical clusters corresponding to polymetallic base metal sulphide mineralization, its proximal alteration zones, and variably metamorphosed host rocks. The results reveal significant sulphide mineralization, ranging from disseminated to massive occurrences of sphalerite, pyrrhotite, pyrite, and galena, with trace amounts of secondary minerals like anglesite in certain samples indicating weathering processes. The study also identifies rare minerals such as armenite, often overlooked in traditional geological logging. These findings underscore the potential of QXRD to enhance resource estimation, optimize exploration strategies, and contribute to more efficient and sustainable mineral exploration programs. The accuracy of QXRD was cross-validated with geological logs and geochemical data, confirming its reliability as a mineralogical discrimination tool. Full article

Porphyry and the associated skarn-type deposit is one of the most important types of ore deposits worldwide, which usually exhibit significant zoning of mineralization-alteration, but the research on element migration in these mineralization-alteration zones is relatively weak. The Beiya porphyry–skarn gold-polymetallic deposit is a super-large Cenozoic deposit located in the Sanjiang metallogenic belt, northwestern Yunnan, China. In this paper, through a detailed analysis of mineralization and alteration zoning and its element migration regularity, the findings are as follows: (1) Three types of hydrothermal alteration—porphyry alteration, contact alteration, and wall-rock alteration—are developed, and porphyry alteration includes potassic, phyllic, propylitic, and argillic alteration; (2) five types of mineralization—porphyry-type Cu–Au–(Mo), skarn-type Au–Fe–(Cu), hydrothermal vein-type Au–Fe, distal hydrothermal-type Pb-polymetallic, and oxidizing-leaching enriched-type Au—occur in a diversity of forms, which are dominantly controlled by structures and lithologies; (3) concentric-banded mineralization-alteration zones are exhibited centrally from the alkaline porphyry outward or upward, namely [porphyry alteration] potassic → phyllic → propylitic → argillic → [contact alteration] skarnitization–marbleization → [wall-rock alteration] marbleization–silicification–calcitization; (4) porphyry-type mineralization predominantly forms within potassic and phyllic zones, while skarn-type mineralization occurs in contact alteration zones, and proximal and distal hydrothermal (vein)-type mineralization are commonly distributed in marbleization–silicification–calcitization alteration zones; and (5) element migration analysis demonstrates a significantly lateral and vertical zoning in the metallogenic element association of Cu–Mo → Cu–Au → Au–Fe–Cu → Au–Fe → Pb–Zn–Au–Ag–Fe from alkaline porphyry outward to the wall-rock. The mineralization-alteration zoning model indicates the Beiya deposit has similar mineralization and alteration zone characteristics to the typical porphyry copper system; and element migration within mineralization-alteration zones provides new scientific information for understanding the metallogenic regularity and prospecting at Beiya, as well as the similar types of deposits in the Sanjiang metallogenic belt and elsewhere in the world. Full article

Antimony is one of the world’s scarcest metals and is listed as a Critical Raw Material (CRM) for the European Union. To meet the increasing demand for metals in a sustainable way, one of the strategies that could be implemented would be the recovery of metals as by-products. This would decrease the amount of hazardous materials filling mining dumps. The present study investigates the potential for producing antimony as a by-product at the Olympias separation plant in Northern Greece. This plant works a skarn mineralization that shows interesting amounts of Sb. Boulangerite (Pb₅Sb₄S₁₁) reports on Pb concentrate levels reached 8% in the analyzed product. This pre-enrichment is favorable in terms of boulangerite recovery since it can be separated from galena through froth flotation. Boulangerite distribution in the primary ore is quite heterogeneous in terms of the inclusion relationships and grain size. However, a qualitative assessment shows that the current Pb concentrate grain size is too coarse to successfully liberate a good amount of boulangerite. The use of image analysis and textural assessments is pivotal in determining shape factors and crystal size, which is essential for the targeting of flotation parameters during separation. The extraction of antimony as a by-product is possible through a two-step process; namely, (i) the preliminary concentration of boulangerite, followed by (ii) the hydrometallurgical extraction of the antimony from the boulangerite concentrate. The Olympias enrichment plant could therefore set a positive example by promoting the benefits of targeted Sb extraction as a by-product within similar sulfide deposits within the European territory. Full article

The Southern Hunan area is located in the superposition of the Qin-Hang Cu-Pb-Zn polymetallic ore belt and the Nanling W-Sn-Mo polymetallic ore belt, which is an important window to study the mineralization of W-Sn-Mo and Cu-Pb-Zn polymetallic deposits. The Baoshan deposit is a large Cu-Pb-Zn polymetallic deposit in Southern Hunan Province with obvious zones of Cu mineralization and Pb-Zn mineralization: the central part of the Baoshan deposit demonstrates contact metasomatic (skarn) Cu mineralization, while the western, northern and eastern parts demonstrate hydrothermal vein Pb-Zn mineralization. However, the origin and evolution of the ore-forming fluid and mechanism of Cu and Pb-Zn mineral precipitation are still unclear. The metallogenic process of the Baoshan Cu-Pb-Zn deposit can be divided into four stages: (1) the early skarn stage (S₁); (2) the late skarn stage (S₂); (3) the Cu-Fe sulfide stage (S₃); and (4) the Pb-Zn sulfide stage (S₄). The results of microtemperature measurements and a Raman spectrometric analysis of fluid inclusions show that the ore-forming fluid was the H₂O-NaCl (-CO₂ ± N₂ ± C₂H₆) system in the skarn stages (S₁ + S₂) and changed into the H₂O-NaCl-CO₂ (±N₂ ± C₂H₆) system in the sulfide stages (S₃ + S₄). The temperature (S₁: 436.6~548.2 °C; S₂: 344.1~435.1 °C; S₃: 134.1~413.1 °C; S₄: 183.9~261.0 °C) and salinity (S₁: 17.4~51.2 wt.%NaClequiv; S₂: 13.6~41.7 wt.%NaClequiv; S₃: 1.2~32.3 wt.%NaClequiv; S₄: 1.8~9.6 wt.%NaClequiv) showed a downward trend from the early to late stages. From the skarn stages (S₁ + S₂) to the sulfide stages (S₃ + S₄), the ore-forming pressure results from the static rock pressure and the hydrostatic pressure, and the ore-forming depth is estimated to be about three to six km. The C-H-O isotopic compositions of hydrothermal minerals such as quartz and calcite indicate that the ore-forming fluid is predominately magmatic fluid, but a significant amount of meteoric water is added in the Pb-Zn sulfide stage (S₄). The formation of the mineralization zonation of the Baoshan deposit is the result of many factors (e.g., stratigraphy, structure and metal precipitation mechanism): the Cu mineralization is controlled by the contact zone, and the Pb-Zn mineralization is controlled by the fault. In addition, the precipitation of Cu is mainly controlled by fluid boiling, while the precipitation of Pb and Zn is mainly controlled by the mixing of magmatic fluid and meteoric water. Full article