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 degrees 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 degrees 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 degrees 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 degrees C), low-salinity, homogeneous NaCl-H2O system. Hydrogen-oxygen isotope data show that the calculated delta 18OH2O values decreased from +6.6 parts per thousand to +6.7 parts per thousand in Stage I to +3.4 parts per thousand to +3.9 parts per thousand in Stage II, and further to -0.4 parts per thousand in Stage III, while the delta D values shifted from -91.6 parts per thousand to -90.6 parts per thousand, to -94.4 parts per thousand to -94.2 parts per thousand, and finally to -95.7 parts per thousand. 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.

Central-southern Jilin Province is located at the junction of the eastern segment of the northern margin of the North China Craton (NCC) and the eastern segment of the Central Asian Orogenic Belt (CAOB), and is a major gold-producing area in Northeast China. While numerous lode gold deposits are well documented in Archean metamorphic rocks and Mesozoic granites, Paleozoic metamorphic sequences remain poorly studied despite their considerable gold metallogenic potential in this region. As a typical deposit hosted in Paleozoic metamorphic rocks, the Erdaodianzi gold deposit still lacks systematic constraints on its ore genesis and the early-stage arsenopyrite gold enrichment mechanism. To address these issues through integrated petrography, in-situ LA-ICP-MS trace element analysis, EPMA, elemental mapping, and in-situ sulfur isotope analysis identify three generations of arsenopyrite (Apy1, Apy2a, Apy2b) and three mineralization stages: quartz-arsenopyrite-pyrite (stage I), quartz-polymetallic sulfide-native gold (stage II, the main gold mineralization stage), and quartz-carbonate-electrum (stage III). Gold occurs in arsenopyrite as both visible and invisible forms. Gold content reaches the highest level in Apy2a (up to 61.64 ppm), controlled by As-S substitution and charge compensation involving Cu+, Te2-, and Se2-. Arsenopyrite geothermometry yields decreasing temperatures from 370 to 465°C (Apy1) to 270–355°C (Apy2a) and 290–345°C (Apy2b). In-situ sulfur isotope values of arsenopyrite range from –5.66‰ to –4.06‰, indicating a dominantly magmatic sulfur source. Based on these findings, the Erdaodianzi gold deposit is classified as a mesothermal magmatic-hydrothermal lode gold deposit. This study establishes a genetic model for gold mineralization in Paleozoic metamorphic rocks and provides theoretical support for regional exploration in Northeast China.

The Dajing Cu-Sn polymetallic deposit, situated within the southern Great Xing’an Range of northern China, is a representative Mesozoic magmatic–hydrothermal system within a major Cu–Sn–Ag–Pb–Zn metallogenic belt. Located at the junction between the Siberian and North China plates, the deposit occurs within a composite tectonic domain overprinted by the Paleo-Asian, Mongol–Okhotsk, and Paleo-Pacific systems. Building on field geological constraints and detailed ore petrography, this study utilizes SEM–CL imaging and in situ LA–ICP–MS trace-element analysis of hydrothermal quartz to reconstruct the multistage physicochemical evolution and fluid dynamics of the ore-forming system. Three quartz generations record successive mineralization stages: early QI forms grain cores associated with Stage I cassiterite–arsenopyrite–quartz mineralization; main-stage QII crystallized during or shortly after Stage II chalcopyrite precipitation and exhibits well-developed oscillatory zoning; and late QIII occurs mainly as rim overgrowths and fracture fillings and postdates Stage III ore-mineral precipitation. Quartz is characteristically Ti-poor (4.7–22.8 ppm), and its trace-element systematics indicate a low- to intermediate-temperature hydrothermal signature and a granitic magmatic–hydrothermal affinity. Al, Li, Na, K, and Ge show coupled behavior consistent with heterovalent substitution and vary markedly among quartz generations, with CL-bright QIIa showing relatively higher Al, Ge, and Na relative to CL-dark QIIb, whereas QIII is generally characterized by lower Al, Li, and Ge. Localized anomalously high Cu and Sn values are mainly attributed to the co-ablation of fine-grained mineral inclusions, metal-rich fluid inclusions, or fracture-filling components. These features indicate a chemically heterogeneous fluid reservoir with inferred relatively acidic conditions during the initial Sn-mineralization stage. The fluid system subsequently experienced recurrent physicochemical fluctuations associated with pulsed fluid input during the principal Cu-mineralization stage. QIII records a trace element-depleted late-fluid system associated with the terminal pyrite–quartz stage. Late fluids migrated along earlier quartz boundaries and fractures and may have undergone further cooling and dilution through fluid mixing and/or water–rock interaction. Overall, the fluid system shows a progressive shift in inferred fluid chemistry, consistent with decreasing acidity during hydrothermal evolution.

Northeast (NE) China is characterized by a predominance of Mesozoic deposits and a scarcity of Paleozoic deposits. The Paleozoic deposits are mainly distributed along the Xar Moron-Changchun-Yanji suture zone, which holds significant importance for studying the Paleozoic tectonic evolution and mineralization processes of the region. The Shizui Cu-polymetallic deposit in Jilin Province, NE China, is the first recognized late Paleozoic Cupolymetallic deposit along the eastern segment of the northern margin of the North China Craton (NCC). The mineralization process can be divided into three stages: the skarn stage, the early quartz-sulfide stage, and the late quartz-sulfide stage. The early quartz-sulfide stage is the major stage of Cu mineralization. The metallic minerals developed in the deposit are dominated by magnetite, arsenopyrite, pyrite, chalcopyrite, sphalerite, and galena. In-situ laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) data indicate that in magnetite, Si4+ and Al3+ mainly enter the magnetite lattice through isomorphous substitution of Fe3+, rather than in the form of micro-inclusions of silicate minerals. Elements such as Pb, Zn, Ag, and Bi exist in chalcopyrite as micro-inclusions, while Au, Ag, Pb, and Sb in pyrite are mainly present in the form of solid solutions. In addition, magnetite, chalcopyrite, and pyrite all exhibit hydrothermal origin. Using the magnetite TMg-Mag geothermometer, the average TMg-Mag temperatures of the two generations of magnetite (Mag1 and Mag2) are calculated to be 596 degrees C and 468 degrees C, respectively. The delta 34S values of sulfides range from-3.8 %o to-1.3 %o, with an average of-1.9 %o, suggesting deep-source magmatic sulfur or mantle sulfur. The Pb isotope compositions of sulfides (206Pb/204Pb = 18.457-18.516, 207Pb/204Pb = 15.592-15.672, and 208Pb/204Pb = 38.251-38.517) are consistent with those of monzogranite (206Pb/204Pb = 18.386-19.006, 207Pb/204Pb = 15.547-15.624, and 208Pb/204Pb = 38.348-38.667). The S-Pb isotope results indicate that the ore materials are mainly derived from the magmas forming the monzogranite. During the late Paleozoic, magmatic fluids underwent reactions with carbonate wall rocks under high oxygen fugacity (fO2) conditions, forming magnetite containing Si and Al. As the sulfur fugacity (fS2) in the hydrothermal system increased, the elevated concentration of HS-drove the precipitation of sulfides such as chalcopyrite, sphalerite, and galena, ultimately forming the Shizui skarn-type Cupolymetallic deposit. Comprehensive analysis indicates that the Shizui Cu-polymetallic deposit is an early Permian skarn-type deposit, and the ore-forming materials are similar to that of the skarn-type Cu-polymetallic deposits in the Tianbaoshan ore district, both associated with the late Paleozoic intermediate-acidic intrusions. This suggests that the Xar Moron-Changchun Metallogenic Belt (XCMB) extends eastward and has significant prospecting potential for exploring late Paleozoic Cu-polymetallic deposits.

As one of the important gold mineralization belts in China, the eastern segment of the northern margin of the North China Craton (NCC) has been the subject of extensive research on magmatic-hydrothermal gold deposits. However, the relationship between the Middle Triassic gold mineralization and magmatism related to the evolution of the Paleo-Asian Ocean remains poorly constrained. Taking the ore-related granites of the Baizhangzi (BZZ), Jinchanggouliang (JCG), and Zhuanshanzi (ZSZ) gold deposits in this region as research objects, we present their zircon U-Pb dating, whole-rock major and trace element compositions, and Sr-Nd-Pb-Mo isotopic data, aiming to clarify their petrogenesis and relationship to gold mineralization. LA-ICP-MS zircon U-Pb dating indicates that these gold mineralization-related granites were emplaced in the Middle Triassic (240 to 237 Ma). These granites display high SiO2, Sr contents, Sr/Y, (La/Yb)N ratios, and low Y, Yb, MgO contents, indicating that they belong to thickened lower crust-derived adakitic granites. Negative epsilon Nd(t) values (-2.5 to-2.8) and old TDM2 ages (1216 to 1243 Ma) suggest that the magma sources of JCG porphyritic granite and ZSZ monzogranite contain lower crustal components. In contrast, the BZZ syenogranite displays lower epsilon Nd(t) values (-6.8 to-7.6), (206Pb/204Pb)t ratios (16.235 to 17.838), and older TDM2 ages (1567 to 1625 Ma) of the BZZ syenogranite suggests its magma source consists of older lower crust with minor mantle-derived components. The delta 98/95Mo values of the BZZ syenogranite, JCG porphyritic granite, and ZSZ monzogranite are 0.08%o to 0.29%o, 0.24%o to 0.30%o, and-0.14%o to 0.06%o, respectively. The delta 98/95Mo variations indicate their magma sources experienced variable metasomatized by anoxic sediment melts. Sulfur-hydrogen complexes in anoxic sediment melts can efficiently extract gold. Such metasomatism of sediment melts may represent a key controlling factor for gold mineralization in the northern margin of the NCC.

The Dajing giant Cu-Sn polymetallic deposit is located in the Cu-Sn-Ag-Pb-Zn polymetallic belt of the southern Great Xing'an Range, NE China. Research on its ore genesis is of great significance for understanding Sn polymetallic mineralization in this region. In this study, pyrite, arsenopyrite, and sphalerite were analyzed by electron-microprobe analysis (EMPA) and in situ S-Pb isotope analysis. Previously published fluid-inclusion microthermometric and H-O isotope data were also incorporated to constrain fluid evolution and ore genesis. Both in situ S and Pb isotopic compositions fall within short ranges. The delta 34S values suggest a sulfur reservoir with possible magmatic contribution, whereas Pb isotopes indicate a mainly crustal Pb signature in an orogenic setting. Arsenopyrite records variations in As, S, Fe, and Co contents from core to rim. The Co-rich core shows Co enrichment accompanied by Fe depletion, consistent with Co-for-Fe isomorphous substitution. These features indicate changes in local fluid chemistry during arsenopyrite growth. Sulfur isotope geothermometry based on coexisting late-stage pyrite-sphalerite pairs yields 118-233 degrees C, with an average of 159 +/- 49 degrees C, indicating medium- to low-temperature hydrothermal activity during the late sulfide stage. The Dajing deposit is interpreted as a fault-controlled hydrothermal vein-type Cu-Sn polymetallic deposit formed in a Late Jurassic extensional setting. Ore precipitation was likely promoted by cooling during upward fluid migration away from the magmatic heat source, pressure release, meteoric-water mixing, and fluid-rock interaction with granitic rocks and Linxi Formation wall rocks. This study provides mineral-scale constraints on fluid evolution and ore genesis in the Great Xing'an metallogenic belt.

The Erdaodianzi gold deposit in Jilin Province, Northeast China, is a newly discovered large-scale gold deposit within the Paleozoic metamorphic rock sequences in the eastern segment of the northern margin of the North China Craton. The mineralization process of the Erdaodianzi gold deposit can be divided into four stages: quartz-pyrite-arsenopyrite (Stage I), quartz-pyrite-arsenopyrite-pyrrhotite-native gold-chalcopyrite (Stage II), quartz-chalcopyrite-pyrite-sphalerite-galena-electrum-marcasite (Stage III) and quartz-carbonate +/- pyrite (Stage IV). Stage II is the most important for gold mineralization. Pyrite is the dominant gold-bearing mineral, which can be classified into three generations (Py1 to Py3), corresponding to mineralization stage I to stage III, respectively. In order to constrain the ore genesis of the Erdaodianzi gold deposit, Re-Os isotope dating and the geochemistry of pyrite were conducted. The electron probe microanalyzer (EPMA) data of 61 pyrites indicate that the value of S/Fe in pyrites from the Erdaodianzi gold deposit is relatively low (average Py1 = 2.00, Py2 = 1.97, Py3 = 1.96), which suggests a sulfur-deficient character associated with magmatic activity. The in situ Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS) data indicate that pyrites (Py2) from the major mineralization stage are rich in Au, As, Cu, Pb, and Zn, but poor in Co, Ni, Sb, and Bi. Visible gold grains are primarily composed of native gold and electrum. The gold content in pyrite is significantly below the gold solubility limit, indicating that invisible gold exists in the pyrite lattice in the form of Au+. In the Erdaodianzi gold deposit, fluid boiling and immiscibility led to the escape of volatiles and oxygen fugacity (fO(2)) in the ore-forming fluids decreased, causing the instability of the Au(HS)(2)(-) complex, which promotes the precipitation of gold and the formation of gold-bearing sulfides. In this study, the sulfur isotopic values of pyrites (Py1 = 0.73 parts per thousand-2.05 parts per thousand, Py2 = 1.78 parts per thousand-3.24 parts per thousand, Py3 = 4.16 parts per thousand-5.89 parts per thousand) indicates that the mineralization materials of the Erdaodianzi gold deposit mainly originate from magma. Additionally, the high Co/Ni ratio indicates that the pyrite is a magmatic-hydrothermal source. The Re-Os isotopic dating of five pyrites (Py2) from the Erdaodianzi gold deposit yield an isochron age of 172 +/- 3 Ma (MSWD = 0.29) and the weighted average of the model ages is 172 +/- 2 Ma (MSWD = 0.84), which constrains the mineralization age of the Erdaodianzi gold deposit to the Middle Jurassic. Based on all available data and regional geological, the Erdaodianzi gold deposit is a Middle Jurassic mesothermal magmatic-hydrothermal vein-type gold deposit. Comparative studies of the Erdaodianzi gold deposit and other gold deposits on the Jiapigou-Haigou gold belt (JHGB), it is confirmed that they are similar in terms of ore genesis and associated with the subduction of the Paleo-Pacific Plate during the Middle Jurassic. This suggests that the JHGB extends northwestward, providing a theoretical basis for new regional exploration directions.

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.

In recent years, the number of non-ferrous metal and precious metal deposits has been widely developed [...]

The Cuyu gold deposit in central Jilin Province in Northeast China is located in the eastern segment of the northern margin of the North China Craton (NCC), as well as the eastern segment of the Xing’an–Mongolian Orogenic Belt (XMOB). Gold ore-bodies are controlled by NW-trending faults and mainly occur in late Hercynian granodiorite. The mineralization process in the Cuyu deposit can be divided into three stages: quartz + coarse grained arsenopyrite + pyrite (stage I), quartz + sericite + pyrite + arsenopyrite + electrum + chalcopyrite + sphalerite (stage II), and quartz + calcite ± pyrite (stage III). Stage II is the most important for gold mineralization. We conducted analyses including petrography, microthermometry, laser Raman spectroscopy of fluid inclusions, and H–O–S–Pb isotopic analysis to elucidate the mineralization processes in the Cuyu deposit. Five types of primary fluid inclusions (FIs) are present in the hydrothermal quartz and calcite grains of the ore: liquid-rich two-phase aqueous fluid inclusions (L-type), vapor-rich two-phase aqueous fluid inclusions (V-type), CO2-bearing two- or three-phase inclusions (C1-type), CO2-rich two- or three-phase inclusions (C2-type), and pure CO2 mono-phase inclusions (C3-type). From stages I to III, the fluid inclusion assemblages changed from L-, C2-, and C3-types to L-, V-, C1-, C2-, and C3-types and, finally, to L-types only. The corresponding homogenization temperatures for stages I to III were 242–326 °C, 202–298 °C, and 106–188 °C, and the salinities were 4.69–9.73, 1.63–7.30, and 1.39–3.53 wt.% NaCl equiv., respectively. The ore-forming fluid system evolved from a NaCl-H2O-CO2 ± CH4 ± H2S fluid system in stage I and II with immiscible characteristics to a homogeneous NaC-H2O fluid system in stage III. Microthermometric data for stages I to III show a decreasing trend in homogenization temperatures and salinities. The mineral assemblages, fluid inclusions, and H–O–S–Pb isotopes indicate that the initial ore-forming fluids of stage I were exsolved from diorite porphyrite and characterized by a high temperature and low salinity. The addition of meteoric water in large quantities led to decreases in temperature and pressure, resulting in a NaCl-H2O-CO2 ± CH4 ± H2S fluid system with significant immiscibility in stage II, facilitating the deposition of gold and associated polymetallic sulfides. The Cuyu gold deposit has a similar ore genesis to those of gold deposits in the Jiapigou–Haigou gold belt (JHGB) of southeastern Jilin Province indicating potential for gold prospecting in the northwest-trending seam of the JHGB.

The Bujinhei deposit, a representative vein-type Pb-Zn mineralization, is situated on the western slope of the southern Great Xing'an Range (SGXR). The ore bodies of Bujinhei are primarily hosted within Permian sedimentary rocks and structurally controlled by nearly EW-trending faults. Three types of fluid inclusions (FIs), including gas-liquid two-phase inclusions (Type-1), CH4 (+/- CO2)-rich inclusions (Type-2), and pure CH4-CO2 inclusions (Type-3) can be recognized in hydrothermal veins. Laser Raman spectral analysis further confirmed that the gas phase of these fluid inclusions contained large amounts of CH4. Petrographic analysis, micro-thermometry, and laser Raman spectroscopy of fluid inclusions suggest that the ore-forming fluids comprise a NaCl-H2O-CH4 +/- CO2 system, characterized by moderate temperatures and low salinity. Oxygen and hydrogen isotope data for quartz and carbonate from the ore-bearing veins fell between the fields of typical magmatic and meteoric water (S18Ofluid = 4.0 %o-7.2 %o, SDfluid =-123.1 %o to-112.7 %o). The extremely low SDfluid values of Bujinhei fluids could be due to water-rock reactions between ore fluids and carbonaceous strata. The S13C PDB value of the CH4 in fluid inclusions ranged from-31.8 %o to-27.9 %o, also suggesting the hydrolysis of organic matter in the sedimentary was involved in the mineralizing fluids. Sulfides from the Bujinhei show restricted S34SCDT values of-3.2 to-0.7 %o, without the diagnostic signature of sedimentary sulfur. These sulfides have 206Pb/204Pb = 18.200-18.285, 207Pb/204Pb = 15.519-15.623, and 208Pb/204Pb = 38.020-38.364, overlapping with most of the hydrothermal vein type deposits, which were sourced primarily from deep-seated magma. Genetically, the Bujinhei Pb-Zn deposit shows characteristics of a typical reduced hydrothermal system, which may be originally magmatic-related and dramatically influenced by carbonaceous-reducing rocks. The investigation results presented in this paper provide compelling evidence that carbonaceous wall rocks exert a substantial influence on the formation of reducing conditions in lead-zinc ore-forming hydrothermal systems in the southern Great Xing'an Range.

The southwestern region of China is tectonically situated within the Tethyan tectonic domain, with the eastern part comprising the Upper Yangtze Block, while the western orogenic belt forms the main part of the Tibetan Plateau. This belt was formed by the subduction of the Paleo-Tethys Ocean and subsequent arc-continent collision, and was later further modified by the India-Asia collision, resulting in complex geological structures such as the Hengduan Mountains. The lithostratigraphy in this region can be divided into six independent units. In terms of mineralization, the area encompasses two first-order metallogenic domains: the Tethyan-Himalayan and the Circum-Pacific. This study synthesizes extensive previous research to systematically investigate representative rare earth element (REE) deposits (e.g., Muchuan and Maoniuping in Sichuan; the Xinhua deposit in Guizhou; the Lincang deposit in Yunnan). Through comparative analysis of regional tectonic-metallogenic settings, we demonstrate that REE distribution in Southwest China is fundamentally controlled by Tethyan tectonic evolution: sedimentary-weathered types dominate in the east, while orogenic magmatism-related types prevail in the west. These findings reveal critical metallogenic patterns, establishing a foundation for cross-regional resource assessment and exploration targeting. The region hosts 32 identified REE occurrences, predominantly light REE (LREE)-enriched, genetically classified as endogenic, exogenic, and metamorphic deposit types. Metallogenic epochs include Precambrian, Paleozoic, and Mesozoic-Cenozoic periods, with the latter being most REE-relevant. Six prospective exploration areas are delineated: Mianning-Dechang, Weining-Zhijin, Long’an, Simao Adebo, Shuiqiao, and the eastern Yunnan-western Guizhou sedimentary-type district. Notably, the discovery of paleo-weathering crust-sedimentary-clay type REE deposits in eastern Yunnan-western Guizhou significantly expands regional exploration potential, opening new avenues for future resource development.

The newly discovered Bayanbaolege Ag-Pb-Zn deposit is located in the Southern Great Hinggan Range metal-logenic belt, northeastern China, with 1440 t Ag, 380000 t Zn, 50000 t Pb, and a beneficial component of Cd (806 t Cd) and Ga (211 t Ga). The orebodies of this deposit occur as veins and are hosted mainly by a contact zone between the Permian silty slate and the granite intrusion, and have a closely spatio-temporal relationship with the early Cretaceous granodiorite porphyry intrusion. The mineralization process of the Bayanbaolege deposit can be divided into three mineralization stages including arsenopyrite-pyrite-quartz stage (stage I), pyrite-pyrrhotite-chalcopyrite stage (stage II) and galena-sphalerite-argentite-pyrite-calcite stage (stage III). LA-ICP-MS trace element mapping and spot analyses were conducted on the sphalerite and pyrite in stage III at the Bayanbaolege deposit. LA-ICP-MS trace element mapping and spot analyses were conducted on the stage III sphalerite and pyrite selected from the Bayanbaolege deposit in order to identify the occurrence form and distribution characteristics of critical metal elements, constrain the possible controls on the variation of trace elements, reveal the physi-cochemical condition of mineralization and provide new insights into the ore genesis. The results show that Ga, Ge, In, Cd, Mn, Cu, Ag and Co concentrations in sphalerite, and pyrite is the preferential host for Ge, As and Ni. The occurrence of Ga, Ge, In and Cd in sphalerite are mainly deposited in form of isomorphism. Physicochemical condition studies suggest that sphalerite precipitated from a medium-temperature hydrothermal system with the range from 190 degrees C to 291 degrees C (average at 230 degrees C) and accompanied with the intermediate fS2. Trace element concentrations of sphalerite are different from that of the MVT, VMS, SEDEX and skarn deposits. The results of this study, combined with the previous geological and physicochemical evidence, indicate that the Bayanbaolege Ag-Pb-Zn deposit deposit is an intrusion-related mesothermal hydrothermal vein-type deposit.

The Hongqiling large nickel-copper-cobalt deposit (hereafter referred to as the Hongqiling deposit), a typical mafic-ultramafic copper-nickel deposit in China, boasts proven Ni (Ni) resources of approximately 22×104 t, associated copper resources of 2×104 t, and associated cobalt (Co) resources of 0.5×104 t, with Ni reserves ranking 10th among China’s magmatic nickel deposits. Geotectonically, the Hongqiling deposit is situated in the superimposed zone between the Xing’an-Mongolian orogenic belt and the circum-Western Pacific’s active continental margin belt. Its ore-bearing plutons occur within the metamorphic rocks of the Ordovician Hulan Group, with the emplacement of plutons and the locations of orebodies governed by the deep-seated Huifahe fault and its secondary NW-trending Fujia-Hejiagou-Beixinglong-Changsheng fault zone. In the deposit, the rock assemblages of ore-bearing plutons predominantly encompass gabbro - pyroxenite - olivine pyroxenite - pyroxene peridotite (pluton No. 1) and noriteorthopyroxenite-harzburgite (pluton No. 7), with ore-bearing lithofacies consisting primarily of olivine pyroxenite and pyroxenite facies. The Hongqiling deposit hosts stratoid, overhanging lentoid, veined, and pure-sulfide veined orebodies. Its ores principally contain metallic minerals including pyrrhotite, pentlandite, chalcopyrite, violarite, and pyrite. Despite unidentified magma sources of ore-bearing mafic-ultramafic rocks, it is roughly accepted that the magmatic evolution in the Hongqiling deposit primarily involved fractional crystallization and crustal contamination. The ore-forming materials were primarily derived from the upper mantle, mixed with minor crustal materials. The ore-bearing mafic-ultramafic rocks in the deposit, primarily emplaced during the Indosinian (208–239 Ma), were formed in an intense extension setting followed by the collisional orogeny between the North China Plate and the Songnen-Zhangguangcai Range Block during the Middle-Late Triassic. From the perspective of the metallogenic geological setting, surrounding rocks, ore-controlling structures, and rock assemblages, this study identified one favorable condition and seven significant indicators for prospecting for Hongqiling-type nickel deposits and developed a prospecting model of the Hongqiling deposit. These serve as valuable references for exploring similar nickel deposits in the region, as well as the deep parts and margins of the Hongqiling deposit.

The Daheishan supergiant porphyry molybdenum deposit (also referred to as the Daheishan deposit) is the second largest molybdenum deposit in Asia and ranks fifth among the top seven molybdenum deposits globally with total molybdenum reserves of 1.65 billion tons, an average molybdenum ore grade of 0.081%, and molybdenum resources of 1.09 million tons. The main ore body is housed in the granodiorite porphyry plutons and their surrounding inequigranular granodiorite plutons, with high-grade ores largely located in the ore-bearing granodiorite porphyries in the middle-upper part of the porphyry plutons. Specifically, it appears as an ore pipe with a large upper part and a small lower part, measuring about 1700 m in length and width, extending for about 500 m vertically, and covering an area of 2.3 km(2). Mineralogically, the main ore body consists of molybdenite, chalcopyrite, and sphalerite horizontally from its center outward and exhibits molybdenite, azurite, and pyrite vertically from top to bottom. The primary ore minerals include pyrite and molybdenite, and the secondary ore minerals include sphalerite, chalcopyrite, tetrahedrite, and scheelite, with average grades of molybdenum, copper, sulfur, gallium, and rhenium being 0.081%, 0.033%, 1.67%, 0.001%, and 0.0012%, respectively. The ore-forming fluids of the Daheishan deposit originated as the CO2-H2O-NaCl multiphase magmatic fluid system, rich in CO2 and bearing minor amounts of CH4, N-2, and H2S, and later mixed with meteoric precipitation. In various mineralization stages, the ore-forming fluids had homogenization temperatures of > 420 degrees C-400 degrees C, 360 degrees C-350 degrees C, 340 degrees C-230 degrees C, 220 degrees C-210 degrees C, and 180 degrees C-160 degrees C and salinities of > 41.05%-9.8% NaCleqv, 38.16%-4.48% NaCleqv, 35.78%-4.49% NaCleqv, 7.43% NaCleqv, and 7.8%-9.5% NaCleqv, respectively. The mineralization of the Daheishan deposit occurred at 186-167 Ma. The granites closely related to the mineralization include granodiorites (granodiorite porphyries) and monzogranites (monzogranite porphyries), which were mineralized after magmatic evolution (189-167 Ma). Moreover, these mineralization-related granites exhibit low initial strontium content and high initial neodymium content, indicating that these granites underwent crust-mantle mixing. The Daheishan deposit formed during the Early-Middle Jurassic, during which basaltic magma underplating induced the lower-crust melting, leading to the formation of magma chambers. After the fractional crystallization of magmas, ore-bearing fluids formed. As the temperature and pressure decreased, the ore-bearing fluids boiled drops while ascending, leading to massive unloading of metal elements. Consequently, brecciated and veinlet-disseminated ore bodies formed.(c) 2023 China Geology Editorial Office.

The newly discovered Xiaohongshilazi deposit located in Panshi City, central Jilin Province, NE China, is a medium-scale Pb–Zn–(Ag) deposit. The Pb–Zn–(Ag) orebodies are divided into layered and vein-type orebodies, which have different ore geneses. The layered Pb–Zn orebodies are mainly hosted within and spatially controlled by the volcanic rocks. To constrain the age and tectonic setting of the layered Pb–Zn mineralization, we completed laser-ablation–ICP–MS zircon U–Pb dating and whole-rock major and trace element analyses of the ore-bearing volcanic rocks. The dacite samples were confirmed as belonging to the Daheshen Formation and were the main ore-bearing volcanic rocks for the layered orebodies. They yielded concordia U–Pb ages of 278.1 ± 1.8 Ma and 278.3 ± 1.8 Ma, respectively, indicating that the volcanic rocks from the Daheshen Formation and related layered Pb–Zn mineralization were formed in the early Permian. The andesite and rhyolite located above the layered orebodies yielded concordia U–Pb ages of 225.0 ± 1.1 Ma, 225.3 ± 1.5 Ma, and 224.7 ± 1.2 Ma, respectively; these substances are considered to be of the Sihetun Formation and were first reported in the area. The dacite samples associated with layered Pb–Zn mineralization were high in SiO2 (62.54–65.02 wt.%), enriched in LREEs and LILEs (e.g., Rb, Ba, and K), and showed depletion in HFSEs (e.g., P and Ti). It showed slightly negative Eu anomalies (δEu = 0.60–0.65) and negative Nb anomalies, with Th/Nb (1.12–1.21) and La/Nb (2.8–4.7) ratios, presenting subduction-related arc magma affinity formed in an active continental margin setting. In agreement with previous studies on zircon Hf isotopes (εHf (t) = +0.23~ +10.60) of the volcanic rocks from the Daheshen Formation, we infer that they were derived from the partial melting of the depleted lower crust. In conclusion, mineralization characteristics, geochronological data, geochemical features, and regional tectonic evolution suggest that two Pb–Zn–(Ag) mineralization stages from the Xiaohongshilazi deposit occurred: the layered VMS-type Pb–Zn mineralization associated with the marine volcanic rocks from the early Permian Daheshen Formation, which was induced by the subduction of the Paleo-Asian oceanic plate beneath the northern margin of the North China Craton, and the vein-type Pb–Zn–(Ag) mineralization caused by the subduction of the Paleo-Pacific Plate in the early Jurassic. Considering this, along with the mineralization characteristics of the same-type polymetallic deposits in this region, we propose that the early Permian marine volcanic rocks have great prospecting potential for the VMS-type Pb–Zn polymetallic deposits.

The reserves of the Duobaoshan porphyry Cu-Au-Mo-Ag deposit (also referred to as the Duobaoshan porphyry Cu deposit) ranks first among the copper deposits in China and 33rd among the porphyry copper deposits in the world. It has proven resources of copper (Cu), molybdenum (Mo), gold (Au), and silver (Ag) of 2.28x10(6) t, 80x10(3) t, 73 t, and 1046 t, respectively. The major characteristics of the Duobaoshan porphyry Cu deposit are as follows. It is located in a zone sandwiched by the Siberian, North China, and paleo-Pacific plates in an island arc tectonic setting and was formed by the Paleozoic mineralization and the Mesozoic mineralization induced by superposition and transformation. The metallogenic porphyries are the Middle Hercynian granodiorite porphyries. The alterations of surrounding rocks are distributed in a ring form. With silicified porphyries at the center, the alteration zones of K-feldspar, biotite, sericite, and propylite occur from inside to outside. This deposit is composed of 215 ore bodies (including 14 major ore bodies) in four mineralized zones. Ore body No. X in the No. 3 mineralized zone has the largest resource reserves, accounting for more than 78% of the total reserves of the deposit. Major ore components include Cu, Mo, Au, Ag, Se, and Ga, which have an average content of 0.46%, 0.015%, 0.16 g/t, 1.22 g/t, 0.0003%, and 0.001% -0.003%, respectively. The ore minerals of this deposit primarily include pyrite, chalcopyrite, bornite, and molybdenite, followed by magnetite, hematite, rutile, gelenite, and sphalerite. The ore-forming fluids of this deposit were magmatic water in the early metallogenic stage and then the mixture of meteoric water and magmatic water at the late metallogenic stage. The ore-forming fluids experienced three stages. The ore-forming fluids of stage I had a hydrochemical type of H2O-CO2-NaCl, an ore-forming temperature of 375 -650 degrees C, and ore-forming pressure of 110-160 MPa. The ore-forming fluids of stage II had a hydrochemical type of H2O-CO2-NaCl, an ore-forming temperature of 310 -350 degrees C, and ore-forming pressure of 58-80 MPa. The ore-forming fluids of stage III had a hydrochemical type of NaCl-H2O, an ore-forming temperature of 210 -290 degrees C, and ore-forming pressure of 5-12 MPa. The Cu-Au-Mo-Ag mineralization mainly occurred at stages I and II, with the ore-forming materials having a mixed crust-mantle source. The Duobaoshan porphyry Cu deposit was formed in the initial subduction environment of the Paleo-Asian Ocean Plate during the Early Ordovician. Then, due to the closure of the Mongol-Okhotsk Ocean and the subduction and compression of the Paleo-Pacific Ocean, a composite orogenic metallogenic model of the deposit was formed. In other words, it is a porphyry -epithermal copper-gold polymetallic mineralization system of composite orogeny consisting of Paleozoic island arcs and Mesozoic orogeny and extension. (c) 2023 China Geology Editorial Office.

双尖子山矿床位于大兴安岭南段,巴林左旗境内,是我国近年来新发现的一个超大型银多金属矿床.为了确定矿区内与矿体空间关系密切的蚀变斑岩与银多金属矿化在成因上的联系,及其物质来源特点,笔者等对其进行了锆石LA-ICP-MS U-Pb定年和Lu-Hf同位素的综合研究.结果表明,矿区内出露的近矿蚀变斑岩的形成时代为248.3±1.2 Ma,属早三叠世岩浆作用的产物.该岩体形成于银多金属矿化之前,在成因上与银多金属矿化并没有直接的联系.锆石原位Lu-Hf同位素分析结果表明,双尖子山矿区早三叠世蚀变斑岩的n(176Hf)/n(177Hf)值在0.282805～0.282993452之间,εHf(t)值介于6.3～12.9之间.锆石Hf同位素二阶段模式年龄(TDM2)的峰值年龄集中在528 Ma到631 Ma之间,显示出亏损地幔或新生地壳来源的特征.

The volcanic rock system of the Miaoling Formation contains the main ore-bearing rocks of two volcanogenic massive sulfide (VMS)-type deposits in the Yanbian area of NE China. Investigation of the VRSMF is needed to better understand the formation of these VMS-type deposits and the tectonic evolution of the Yanbian area. To determine the petrogenesis, material sources, and formation age of the VRSMF, and elucidate its late Paleozoic tectonic evolution and metallogenic significance, this paper presents new petrological, geochronological, geochemical, whole-rock Sr-Nd and in situ zircon Hf isotopic data for the VRSMF. The VRSMF is composed of marine carbonate, intermediate-felsic volcanic rocks (andesite-trachyandesite-dacite) and pyroclastic rocks. Laser-ablation-inductively coupled plasma-mass spectrometry zircon U-Pb dating gives an eruption age of ca. 265 Ma for the pyroclastic rocks in the VRSMF. These rocks are classified as low-to medium-K calc-alkaline series. They are characterized by enrichments in large-ion lithophile elements (e.g., K, Rb, and Ba) and light rare earth elements, and depletions in high field-strength elements (e.g., Nb, Ta, and Ti) and heavy rare earth ele-ments, showing affinity to igneous rocks formed in arc-related tectonic settings. These features, together with homogeneous zircon epsilon Hf(t) values of 10.9-15.7 and depleted Sr-Nd isotopic compositions [epsilon Nd(t) values of 2.4-5.0], suggest that the parental magma was derived from the partial melting of depleted mantle that had been metasomatized by subduction-related fluids. These results, along with findings of regional geological in-vestigations, suggest that the formation of the VRSMF was related to subduction of the Paleo-Asian oceanic plate during the middle Permian. The VMS-type mineralization in the Hongtaiping and Dongfengnanshan deposits is interpreted to have formed in a bimodal-felsic setting in a back-arc extensional tectonic environment.

The Shanmen deposit, located in the Siping area of Jilin Province, is one of large‐scale silver deposits in Northeast (NE) China. Due to its high Ag grade, associated gold resources and special tectonic location, this deposit has important theoretical and ore‐prospecting significance. To present new data on the ore genesis, mineralization time and tectonic settings, the relationship between silver mineralization and intrusions in this deposit has been studied and some analyses have been carried out, including LA‐ICP‐MS zircon U‐Pb dating, whole‐rock major and trace element analysis and Sr‐Nd‐Pb isotope analysis of the granitoids associated with silver mineralization. Studies on deposit geology indicate that the ore‐hosting granodiorite and monzogranite have intimate genetic relationships with silver mineralization. LA‐ICP‐MS zircon U‐Pb dating results of the both intrusions are 167.6 ± 1.9 Ma and 167.0 ± 1.5 Ma, respectively, implying that the two intrusions and associated silver mineralization in the Shanmen deposit formed during the Middle Jurassic. Major element analytical data suggest that the two intrusions are high‐K calc–alkaline series I‐type granites and belong to metaluminous and peraluminous rocks. Both intrusions have similar REE characteristics with regard to the relative enrichment of LREEs, depletion of HREEs, obvious fractionation of LREEs and HREEs (ΣLREE/ΣHREE = 8.68–14.09, (La/Yb) N = 12.51–21.96), moderately negative Eu anomalies as well as weakly negative Ce anomalies ( δ Eu = 0.56–0.71, δ Ce = 0.93–1.09). Moreover, the samples are generally enriched in LILEs and depleted in HFSEs. The rock assemblages and geochemical characteristics of granitoids in the Shanmen deposit suggest that they formed in an active continental margin associated with the Paleo‐Pacific plate subduction. The Sr‐Nd‐Pb isotope compositions show that both the granodiorite and monzogranite have low Sr initial ratios and high Sm/Nd initial ratios. The ε Nd ( t ) values and young Nd‐model ages are –3.2 to –1.7 and 990 Ma to 1110 Ma, respectively. Considering the Sr‐Nd isotope compositions, in conjunction with the relatively high 206 Pb, 207 Pb and 208 Pb, alongside the relatively low 204 Pb, it can be concluded that the Middle Jurassic intermediate‐acidic magma represented by the studied monzogranite and granodiorite in the Shanmen deposit, was derived from the partial melting of juvenile lower crust enriched in mantle‐derived materials and affected by the mixing of ancient crustal materials during the ascension and intrusion processes.