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The Chazangcuo copper-lead-zinc deposit (hereafter referred to as the Chazangcuo deposit) is situated in the northern portion of the western section of the Gangdese polymetallic metallogenic belt in Tibet, with ore bodies strictly governed by Linzizong Group magmatic rocks and EW-trending faults. This study aims to ascertain the mineralization periods, sources of oreforming materials, metallogenic physicochemical conditions, and genesis of this deposit. Based on comprehensive field geological surveys, sampling, and microscopic examination of petrological and mineralogical characteristics, we perform qualitative and quantitative geochemical analyses of major elements, trace elements, and rare earth elements (REEs), fluid inclusions, and sulfur and lead isotopes. The findings reveal that the mineralization process of the Chazangcuo deposit can be divided into three periods and four stages: the magmatic-hydrothermal, hydrothermal, and supergene mineralization periods sequentially, which consist of the mineralization stages of quartz-pyritesphalerite, medium-low-temperature hydrothermal sulfides, chlorite-carbonate minerals, and supergene oxidation in a chronological order. The ore-forming fluids prove to be medium-low-temperature low-density fluids, and the oreforming materials are characteristic of upper crustal-derived materials. The ore-forming environment is a medium-low mineralization temperature, a shallow and weakly reducing environment. Overall, the Chazangcuo deposit is identified as a medium-low-temperature magmatic-hydrothermal deposit. The metallogenic model has the vertical zoning characteristics of lead-zinc in the upper part and copper in the lower part. [ABSTRACT FROM AUTHOR]

The eastern Wehai area, bordered by the Mishan Fault, is an important polymetallic mineralization zone in the Jiaodong region. It hosts a series of copper molybdenum, lead zinc, and gold silver polymetallic mineral deposits related to the late Yanshanian Mesozoic intermediate-acidic intrusive magmatic activity. This study investigates the geochemical characteristics, metallogenic age, and ore genesis of the Kuangbei skarn-type copper deposit, a typical deposit in the area. Testing results of rare earth elements (REEs) and micro-elements suggest that the intrusive activities of Weideshan Period magmatic rocks provided both the metallogenic materials and the hydrothermal conditions essential for the deposit formation. Research on stable isotopes of S and Pb indicates a multi-source origin of the ore-bearing hydrothermal fluids. Zircon U-Pb dating reveals that the formation age of Kuangbei Copper Deposit, approximately 116. 6 Ma, is close to the diagenetic age of Weideshan Period magmatic rocks. This deposit is a Mesozoic contact metasomatic (skarn) type copper deposit. [ABSTRACT FROM AUTHOR]

Determining the association of Pb–Zn(-Ag) mineralization with granite is crucial for understanding metallogeny and identifying exploration targets. The genesis of Pb–Zn-Ag-Sb deposits and their genetic association with Sb(-Au) deposits and granite-associated Sn-W deposits in the Tethys Himalaya of southern Tibet, China, remains controversial. Our comprehensive study of in situ element compositions and sulfur isotopes of sulfides, together with in situ quartz oxygen isotopes for the Zhaxikang Pb–Zn-Ag-Sb deposit, sheds light on this issue. LA-ICP-MS analyses of early sulfides in manganosiderite veins, coupled with C-O isotopes of manganosiderite, indicate that the early fluids were enriched in Pb, Zn, Ag, Sb, Sn, and Cu, originating from magmatic fluids mixing with meteoric water. The early formed sulfides underwent fluid-mediated remobilization and dissolution, releasing many metallic elements (e.g., Pb, Zn, and Ag) into later As-Sb-rich fluids. These elements reprecipitated as Fe-poor sphalerite, As-rich pyrite, and abundant Sb-Pb sulfosalts with minor Ag-bearing minerals. Oxygen isotopes of quartz indicate that the later fluids were derived from pulsed releases of magmatic fluids mixing with meteoric water. In situ sulfur isotopes of three generations of pyrite indicate that early Pb–Zn(-Ag) sulfide precipitation was linked to magmatic sulfur, whereas precipitation of the later sulfosalts and stibnite involved external sulfur with relatively lower sulfur isotopes compared with early mineralization. We argue that Pb–Zn-Ag-Sb deposits in the Tethys Himalaya resulted from two distinct mineralization pulses. The early Pb–Zn(-Ag) mineralization was associated with crustal magmatic rocks (e.g., leucogranite), followed by the overprinting of later Sb-rich magmatic fluids. Notably, the later magmatic fluids responsible for Zhaxikang Pb–Zn-Ag-Sb mineralization were also associated with the regional Sb(-Au) deposits in the Tethys Himalaya. [ABSTRACT FROM AUTHOR]

Objective Numerous iron deposits hosted in Carboniferous marine volcanic rocks occurred in the Beishan Orogenic Belt, Eastern Tianshan.The Biyushan iron deposit, located at the northwestern margin of Inner Mongolia, is a typical iron deposit hosted in Carboniferous marine volcanic rocks. Methods In this study, we utilized field observation, microscope imaging, and scanning electron microscopy to charaterize the mineral assemblages of iron ores and microtextures of magnetite and apatite, in order to decipher the genesis of iron ores. Results Our preliminary work has revealed that iron ores in the Biyushan deposit commonly have a mineral assemblage of magnetite-apatite, with apatite having abundant monazite inclusions due to the dissolution-reprecipitation processes.In addition, magnetite grains commonly have high Ti contents with ilmenite exsolution.Thus, the mineral assemblage of iron ores and mineralogical features of apatite and magnetite are similar to these of typical Kiruna-type deposits. Conclusion Based on our preliminary analysis of geological characteristics, we suggest that the Biyushan iron deposit in Inner Mongolia is likely a Kiruna-type iron deposit hosted in submarine volcanic rocks that has not yet been documented.Therefore, these findings can guide future exploration of iron oxide-apatite deposits in this region.

The Jianbeigou gold deposit is a typical lode gold deposit in the Qinling metallogenic belt, located on the southern margin of the North China Craton. Three stages of the hydrothermal process can be distinguished, including the quartz ± pyrite, quartz‐polymetallic sulfide, and quartz‐carbonate ± pyrite stages. From the early to late stages, the homogenization temperatures of primary fluid inclusions are 281–362°C, 227–331°C, and 149–261°C, respectively. The corresponding salinities estimated for these fluids are 3.9–9.9 wt%, 0.4–9.4 wt%, and 0.7–7.2 wt% NaCl equiv. Combined with laser Raman spectroscopy data, the ore‐forming fluid belongs to a H2O‐CO2‐NaCl ± CH4 system with medium–low temperature and salinity. The δ18Ofluid and δD values for the quartz veins are –1.0‰ to 6.0‰ and –105‰ to –84‰, respectively, which indicates that the ore‐forming fluid is of mixed source, mainly derived from magma, with a contribution from meteoric water. Pyrite has been identified into three generations based on mineral paragenetic sequencing, including Py1, Py2, and Py3. The pyrites have δ34S sulfur isotopic compositions from three stages between 3.7‰ and 8.4‰, indicating that sulfur mainly originated from magma. Te, Bi, Sb, and Cu contents in pyrite were all high and showed a strong correlation with Au concentrations. Native gold and the Au‐Ag‐Bi telluride minerals were formed concurrently, and the As concentration was low and decoupled from the Au content. Therefore, Te, Bi, Sb and other low‐melting point chalcophile elements play an important role for gold mineralization in arsenic‐deficient ore‐forming fluid. Combined with the geological setting, evolution of pyrite, and ore‐fluids geochemistry, we propose that the Jianbeigou deposit can be classified as a magmatic–hydrothermal lode gold deposit. Gold mineralization on the southern margin of the North China Craton is related to Early Cretaceous magmatism and formed in an extensional setting. [ABSTRACT FROM AUTHOR]

The Mibei gold deposit, located in the southwestern part of the Xuefengshan uplift zone, the middle section of the Jiangnan orogenic belt in southern China, has estimated gold resources of approximately seven tons. This deposit is primarily a quartz vein‐type gold deposit, with ore bodies occurring mainly within Neoproterozoic metasediments. The main metallic minerals in the ore are pyrite, chalcopyrite, and arsenopyrite. In this study, the petrography and microthermometry of ore‐forming fluid inclusions, oxygen isotopes of gold‐bearing quartz, and sulfur isotopes of gold‐bearing sulfides and arsenopyrite were analyzed. Three types of fluid inclusions were identified: type Ia three‐phase inclusions comprising vapor and two phases of liquids (VCO2 + LCO2 + LH2O), type Ib two‐phase liquids (LCO2 + LH2O), type II two‐phase vapor‐rich inclusions (V/V + L > 50%), and type III pure liquid inclusions. Type I inclusions were heated uniformly to the liquid phase, type II inclusions were heated uniformly to the gas phase, and type III inclusions were heated without change. In general, the temperature range of homogenization to liquid phase of fluid inclusions in the Mibei gold deposit is 204–227°C. The salinity of the inclusion ranges from 4.6 to 12.2 wt% NaCl equiv. The δ18OSMOW of gold‐bearing quartz varies from 16.9‰ to 17.5‰. The δ18OH2O of gold‐bearing quartz are varied from 6.5‰ to 7.5‰. The δ34S values of gold‐bearing pyrite range from 1.7‰ to 6.8‰. The δ34S values of gold‐bearing arsenopyrite range from 5.6‰ to 5.9‰. The δ34S values of pyrite from wall rocks slate range from 6.4‰ to 11.6‰. This evidence implies that the ore‐forming fluids of the Mibei gold deposit originated from magmatic‐hydrothermal processes, mixing with minor S from the surrounding metasediments. Combined with the evolution of the Jiangnan orogenic belt, due to the magmatic and tectonic activities of the Xuefengshan uplift during the Caledonian period, the fault seal mechanism controlled the ore‐forming process. Overall, the Mibei gold deposit is more akin to a magmatic‐hydrothermal gold deposit. [ABSTRACT FROM AUTHOR]

Quartz is one of the most common minerals in various hydrothermal ore deposits and has long been the focus of economic geologists and prospecting engineers. With the advancement of high-spatial-resolution observation and microanalysis techniques in recent years, the study of quartz textures and chemistry plays increasingly important roles in understanding ore genesis and guiding mineral exploration. This paper provides a review of recent advances in quartz textures and chemistry and its applications for ore genesis and mineral exploration. We first focus on the detailed observation of quartz textures and relevant generations in hydrothermal ore deposits, and then document the applications of quartz trace elements, isotope and fluid inclusion in tracing the source of ore-forming materials, understanding the ore-forming process, revealing the mechanism of ore enrichment, and providing timing constraints on ore formation. Additionally, this paper also explores vector variation of quartz chemistry and its applications in metallogenic potential analysis, ore types discrimination, and delineation of mineralization centers. Finally, we summarized the main issues that may exist in the current study and provided some prospects for future studies. [ABSTRACT FROM AUTHOR]

The Chazangcuo copper-lead-zinc deposit (hereafter referred to as the Chazangcuo deposit) is situated in the northern portion of the western section of the Gangdese polymetallic metallogenic belt in Tibet, with ore bodies strictly governed by Linzizong Group magmatic rocks and EW-trending faults. This study aims to ascertain the mineralization periods, sources of ore-forming materials, metallogenic physicochemical conditions, and genesis of this deposit. Based on comprehensive field geological surveys, sampling, and microscopic examination of petrological and mineralogical characteristics, we perform qualitative and quantitative geochemical analyses of major elements, trace elements, and rare earth elements (REEs), fluid inclusions, and sulfur and lead isotopes. The findings reveal that the mineralization process of the Chazangcuo deposit can be divided into three periods and four stages: the magmatic-hydrothermal, hydrothermal, and supergene mineralization periods sequentially, which consist of the mineralization stages of quartz-pyrite-sphalerite, medium-low-temperature hydrothermal sulfides, chlorite-carbonate minerals, and supergene oxidation in a chronological order. The ore-forming fluids prove to be medium-low-temperature low-density fluids, and the ore-forming materials are characteristic of upper crustal-derived materials. The ore-forming environment is a medium-low mineralization temperature, a shallow and weakly reducing environment. Overall, the Chazangcuo deposit is identified as a medium-low-temperature magmatic-hydrothermal deposit. The metallogenic model has the vertical zoning characteristics of lead-zinc in the upper part and copper in the lower part.

Objective The Dayingezhuang gold deposit in the middle of the Zhaoping metallogenic belt represents a typical altered-rock type deposit with a giant Au reserve of 283 tons on the Jiaodong Peninsula. The genetic type of the deposit is still controversial. Methods Based on detailed field observations, ore genesis and variations in ore-forming fluids from different depths were investigated in this study. Results Fluid inclusion studies show that the ore-forming fluids formed an H2O-CO2-NaCl±CH4 system with moderate temperature, low salinity, and moderate-low density. Furthermore, the temperatures and salinities decrease gradually from the early to late mineralization stages(Ⅰ-Ⅳ), but the opposite occurs at densities. Hydrogen and O isotopic compositions show that the ore fluids were dominated by magmatic water in the early stage, with subordinate meteoric water input during the late stages. Fluid boiling occurred possibly during the main mineralization stages. Sulfur and Pb isotopes of pyrite indicate that the ore-forming materials were derived from deep crust-mantle mixed magma. Overall, the mineralization process and tectonic setting are similar to those of the other Jiaodong gold deposits in a craton-destruction environment. Conclusion Comprehensive comparisons of ore fluids, Au and Ag contents, and gold fineness between shallow and deep ores show that ore fluids and mineralization intensity are consistent throughout the deposit. Gold precipitation has a broad and stable environment, indicating the great potential for mineral exploration in deep spaces.

The large Dongtangzi Zn-Pb deposit is located in the southwest of the Fengxian–Taibai (abbreviated as Fengtai) ore cluster in the west Qinling orogen. The origin of the deposit is controversial, positing diverse genesis mechanisms such as sedimentary-exhalative (SEDEX), sedimentary-reformed, and epigenetic-hydrothermal types. This study combines systematic ore geology observations with high-precision Rb-Sr and Sm-Nd ages of 211 Ma and in situ S-Pb isotopes to constrain the timing and origin of mineralization. In situ S-Pb isotopic studies show that the sulfide ores display a narrow range of δ34S values from 1.1‰ to 10.2‰, with 206Pb/204Pb, 207Pb/204Pb, and 208Pb/204Pb ratios of 18.07 to 18.27, 15.64 to 15.66, and 38.22 to 38.76, respectively. On the other hand, pyrites of the sedimentary period and the granite porphyry dike have δ34S values ranging from 15.8 to 21.4‰ and from 2.1 to 4.3‰ (with 206Pb/204Pb ratios of 18.09 to 18.10, 207Pb/204Pb ratios of 15.59 to 15.61, and 208Pb/204Pb ratios of 38.17 to 38.24), respectively. The above-mentioned S-Pb isotopic compositions indicate that the metallic materials involved in ore formation originated from a mixture of Triassic magmatic hydrothermal fluid and metamorphic basement. By integrating the regional geology, mineralization ages, and S-Pb isotopic studies, we propose that the Dongtangzi Zn-Pb deposit is the product of epigenetic hydrothermal fluid processes, driven by Late Triassic regional tectono-magmatic processes. [ABSTRACT FROM AUTHOR]

The Yama area is characterized by numerous large-scale fluorite–quartz veins that are located along faults within the widespread Late Devonian–Late Silurian syenogranites in the Tataleng granitic batholith, Qilian Orogen, Northwest China. These fluorite–quartz veins contribute to an important fluorite reserve, but their ore genesis remains unresolved so far. In this study, trace elements, rare earth elements (REEs), and hydrogen, oxygen, and strontium isotopic compositions of fluorites are analyzed. The studied fluorite samples have similar chondrite-normalized REEs, including Y patterns, with relatively strong enrichment in heavy REEs, negative Eu anomalies, strongly positive Y anomalies, and comparably invariable Y/Ho ratios of 41.43–73.79, suggesting a unique hydrothermal genesis. The relatively variable values of δD and δ18O are −77.4‰ to −102.4‰ and −12.7‰ to −4.3‰, respectively, close to the meteoric water line. These fluorites yield relatively invariable analytical 87Sr/86Sr ratios of 0.749089−0.756628 (except for an anomalously high ratio), and their calculated initial 87Sr/86Sr ratios, based on the ore-forming ages provided, are apparently higher than the calculated initial 87Sr/86Sr ratios of syenogranite wall rocks. Collectively, the geochemistry of trace elements, REEs, and stable isotopes (H, O, and Sr) suggests that the ore-forming fluids were of meteoric origin and that the Sr sources were directly derived from the ore-forming fluids themselves rather than syenogranite wall rocks. Finally, it was considered that the Yama fluorite deposit is a fault-controlled hydrothermal vein-type deposit which was possibly related to the evolution of the Paleo-Tethys Ocean in the Permian–Triassic. [ABSTRACT FROM AUTHOR]

The Kangdian iron-copper metallogenic belt on the western margin of the Yangtze landmass is one of the important copper rich and iron rich ore producing areas in China. However, the metallogenic epoch and genesis of many of its deposits are still controversial. Many orebodies of Youheimu iron-copper polymetallic ore deposit located in Mianning, Sichuan, have reached a certain scale. There are few previous studies and reports on this, and its genesis and mineralization age are still unclear. In this paper, the wall rock and ore of the ironcopper orebody of the deposit are analyzed by geochemistry, and the ore is dated with LA-ICP-MS monazite U-Pb. The protolith of wall rock(biotite quartz schist) of the Heheimu iron-copper orebody is argillaceous rock mainly composed of clay minerals formed by volcanic deposition, with the addition of ancient sediment components. The LA-ICP-MS monazite U-Pb dating in Youheimu iron-copper orebody has two groups: one group is 812. 8±4. 6 Ma, representing the formation age of Lengzhuguan formation of Kangding Group; the other group is 698. 5±5. 0 Ma, representing the mineralization age of iron-copper orebody. The hydrothermal fluid brought by acid magma in the east of the study area flows in to the interlayer fracture zone of the wall rock, undergoes metasomatism and skarnization with the surrounding rock, and forms iron-copper orebody. The genesis of the deposit is magmatic hydrothermal skarn. [ABSTRACT FROM AUTHOR]

The Nanmingshui gold deposit, located in the eastern segment of the Kalamaili gold belt (KGB), is hosted by the sub-greenschist facies rocks of the Lower Carboniferous Jiangbasitao Formation. The genesis of this deposit, however, has been debated for decades because of controversial constraints on the P-T-X conditions and origins of hydrothermal fluid and mineralization age. In this study, we present gold-bearing sulfide compositions, fluid inclusions, H-O isotopes, and the results of hydrothermal zircon U-Pb dating to provide new insights into the genesis of the gold deposit. Three gold mineralization stages are recognized: quartz–pyrite–minor native gold veins (early), quartz–tourmaline–arsenopyrite–pyrite–gold–polymetallic sulfide veins (middle), and quartz–calcite veinlets (late). Gold predominantly occurs as native gold with high fineness ranging from 941 to 944 in sulfides and quartz, and some as solid solutions (Au+) within the lattice of pyrite and arsenopyrite. Three types of primary fluid inclusions are identified in hydrothermal quartz: CO2-H2O (C-type), aqueous (W-type), and pure CO2 (PC-type) inclusions. The early-stage quartz mainly contains C-type and minor W-type inclusions, with total homogenization temperatures (Th) of 220–339 °C, salinities of 0.4–3.7 wt.% NaCl eqv., and bulk densities of 0.66–1.01 g/cm3. All three types of inclusions are observed in the middle-stage quartz, of which the C- and W-type inclusions yield Th values of 190–361 °C, with salinities of 0.4–6.0 wt.% NaCl eqv. and bulk densities of 0.69–0.99 g/cm3. The late-stage quartz contains only W-type inclusions that have lower Th values of 172–287 °C, higher salinities of 1.4–6.9 wt.% NaCl eqv., and bulk densities of 0.79–0.95 g/cm3. Trapping pressures estimated from C-type inclusions in the early and middle stages cluster at 280–340 MPa and 220–310 MPa, respectively, corresponding to metallogenic depths of 10–13 km and 8–11 km. The H-O isotopic compositions (δ18Owater = 1.8–10.9‰, δD = −99 to −62.9‰) and microthermometric data indicate that the ore-forming fluids belong to medium–high-temperature, low-salinity, medium-density, and CO2-rich-H2O-NaCl ± CH4 ± N2 systems, probably originating from metamorphic water. Fluid immiscibility is a crucial mechanism for gold precipitation. Additionally, the U-Pb dating of hydrothermal zircons, from the auriferous quartz–tourmaline vein, yield a weighted mean 206Pb/238U age of 314.6 ± 9.6 Ma. Taking all of the above, the Nanmingshui deposit can be reasonably classed as a typical mesozonal orogenic gold deposit in the KGB, which was formed in a Late Carboniferous tectonic transition from syn-collision between the Jiangjunmiao accretionary complex and Yemaquan arc to post-collision in the East Junggar Orogen. Our results serve to better understand the gold mineralization and genesis of the Late Paleozoic orogenic system in the Kalamaili area, Xinjiang. [ABSTRACT FROM AUTHOR]

A small and isolated hydrothermal vein-type Sb deposit is hosted by a lamprophyre dike which penetrated Neoproterozoic to early Cambrian volcanosedimentary successions near Chříč in the Teplá-Barrandian Unit, Czech Republic. Hydrothermal minerals were formed in several consecutive mineralization stages, separated by long pauses in hydrothermal fluid flow. Early Stage I is characterized by the formation of carbonates of dolomite-ankerite series (Carb I) and arsenopyrite with an imprecise Re-Os age of ~570 to 510 Ma. Stage I was followed by tectonic movements and brecciation. The second mineralization stage (Stage II) is characterized by the precipitation of quartz (Qtz I) and Sb minerals (predominantly stibnite) while the third stage (Stage III) is marked by the presence of carbonates of dolomite-ankerite series (Carb II) and quartz (Qtz II) along with Cu, Zn, Pb, Ag and Fe sulfides. Lead isotope data of galena indicate a Variscan age of Stages II-III. These stages were followed by precipitation of another generation of carbonate of dolomite-ankerite series (Carb III, Stage IV), quartz (Qtz III, Stage V) and formation of Sb supergene minerals. The earlier reported occurrence of gold was not confirmed in the studied rock samples but three types of gold particles of variable fineness, with one of them indicating a local origin, were found in the heavy mineral concentrate from a local creek. Elevated Au concentrations were found in arsenopyrite and pyrite. The ore-forming hydrothermal fluid of the mineralization stage III was of H2O-CO2 type with minor CH4 admixture, medium salinity, and temperatures in the range of 258-350 °C with an observed temperature decrease from Stage II to Stage V. Oxygen isotope data of Carb II correspond to high d18Ofluid values (~ +7.5 = VSMOW) with a decrease in the fluid d18O to later stages. An important part of the carbonate carbon was derived from decomposition of organic matter or its high-temperature reaction with hydrothermal fluid. Considering the wide variation in d34S values of sulfides and elevated Sb contents in the TBU black shales, we anticipate that the origin of the Chříč mineralization is closely associated with a metal and carbon-sulfur remobilization from the TBU volcanosedimentary successions in response to Cadomian and Variscan tectonothermal events. [ABSTRACT FROM AUTHOR]

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The Middle–Lower Yangtze Metallogenic Belt (MLYMB) hosts abundant porphyry–skarn–stratabound-type Cu–Au–Mo deposits. Despite extensive research, the origin of the stratabound-type deposits, which developed at the unconformity interface between the Devonian and Carboniferous strata in the MLYMB, remains controversial. The primary debate centers on whether these deposits are the result of Carboniferous sedimentary exhalative mineralization or Mesozoic magmatic–hydrothermal mineralization. In this paper, we examine three representative deposits in the Shizishan orefield: the Chaoshan skarn-type Au deposit, the Hucun porphyry–skarn-type Cu–Mo deposit, and the Dongguashan Cu–(Au) deposit, which has a disputed genesis of its stratiform orebodies. Economically important ore minerals, such as chalcopyrite, molybdenite, and pyrrhotite, and their associated quartz and calcite, were focused on, rather than the extensively studied pyrite in the Tongling region. The ore genesis and sources of mineralized elements in the Shizishan orefield were investigated using H, O, C, S, Pb, and Cu isotopes. The H–O isotopic compositions of hydrothermal quartz from the Chaoshan, Dongguashan, and Hucun deposits indicate that the ore-forming fluids were mainly magmatic water with some meteoric water input. The C–O isotopic compositions of calcite show a large difference from the local sedimentary carbonates. The S isotopic compositions of sulfides reveal a magmatic sulfur signature. The Pb isotopic compositions in the three deposits are similar to those of the Shizishan intrusions, suggesting a magmatic source for Pb. The Cu isotopic compositions of chalcopyrite and pyrrhotite demonstrate that Cu, the primary ore-forming element, was mainly derived from magmatic–hydrothermal fluids. The stratiform orebodies display H–O–C–S–Pb–Cu isotopes consistent with the porphyry orebodies in the Dongguashan deposit, as well as in the Chaoshan and Hucun deposits, indicating a common ore genesis. From these, we conclude that the porphyry–skarn–stratabound-type Cu–Au–Mo deposits in the Shizishan orefield can be classified as a unified Mesozoic magmatic–hydrothermal metallogenic system. The stratabound-type copper sulfide deposits and the porphyry–skarn-type copper deposits in the MLYMB have a strong similarity in the source and genesis of their ore-forming elements. [ABSTRACT FROM AUTHOR]

The Suolong gold deposit is in the eastern part of the Min‐Li metallogenic belt within the West Qinling Orogen. It is hosted in Lower Permian sandstone and siltstone. The gold mineralization is fault‐ and joint‐controlled. Four hydrothermal stages of mineralization, including the sulphide‐quartz stage, the arsenian pyrite‐quartz stage, the polymetallic sulphide‐quartz‐carbonate stage and the sulphide‐carbonate stage, were identified. Here we report results from fluid inclusion studies and C‐H‐O‐S‐Pb isotopes to get insight into the characteristics of mineralization and ore genesis. Fluid inclusion results indicate that the ore‐forming temperatures and salinities were in the range from 135 to 419°C and 0.18 to 15.27 wt.%, respectively. The δ34S values of pyrite, arsenopyrite and pyrrhotite varied in the 5.3‰–11.4‰ range, suggesting that sulphur originated from stratum sulphur. Lead isotopic compositions of sulphide (206Pb/204Pb = 18.344–18.418, 207Pb/204Pb = 15.628–15.701, 208Pb/204Pb = 38.508–38.743) indicate an upper crust source for Pb. The δ18OH2O‐SMOW and δDSMOW values range from 1.01‰ to 10.31‰ and −116.0‰ to −29.2‰, respectively, indicating that metamorphic water was the source of ore‐forming fluids. The δ13CPDB values (−11.4 to −2.1‰) show that the carbon in the ore‐forming fluids originated predominantly from a deep source. Our data suggest that the Suolong gold deposit is an orogenic gold deposit related to the subduction of an oceanic plate along the Mianlue belt. [ABSTRACT FROM AUTHOR]

The Tuotuohe region is a highly prospective area for Pb and Zn mineral exploration. This paper contributes to our comprehension of the ore-controlling structures, fluid inclusions, and C–H–O–S–Pb isotope geochemistry of Pb–Zn deposits in this region. These deposits are generally hosted by carbonates and controlled by fractures. The principal homogenization temperatures of quart- and calcite-hosted inclusions ranged predominantly between 120 and 220 °C, with salinities varying from 6 to 16 wt.% NaCl equivalent. The Pb isotope compositions of the ore deposits are comparable to those of Cenozoic volcanic rocks in the region but differ significantly from those of the host rocks, indicating that the Pb within these deposits was derived from the mantle. The C, O, and S isotope compositions of samples exhibit a bimodal distribution based on whether they were derived from magma or host rocks, implying that magma-derived fluids underwent an isotopic exchange with the host rocks. The H-O isotope compositions of samples also indicate that ore-forming fluids were originally magmatic but were depleted by combining with meteoric water. These findings are also supported by variations in fluid inclusion homogenization temperatures and salinities. Taken together, these findings suggest that the Pb–Zn deposits of the Tuotuohe region developed from magma to hydrothermal fluids at medium–low temperatures. [ABSTRACT FROM AUTHOR]

The medium-sized Songjianghe Au deposit is located in the southeastern part of the Jiapigou-Haigou gold belt (JHGB) in central eastern Jilin Province, NE China. The gold mineralization is primarily characterized by disseminated-style ores and hosted in the low-/medium-grade metamorphic rocks of the Seluohe Group. The ore bodies are governed by NNW-striking brittle-ductile structures and spatially correlated with silicic and sericitic alterations. Four alteration/mineralization stages have been distinguished: (I) Quartz-pyrrhotite-pyrite, (II) quartz-polymetallic sulfides, (III) quartz-pyrite, and (IV) quartz-calcite. The fluid inclusion (FI) assemblage in quartz from Stage I comprises C1-type, C2-type, C3-type, and VL-type FIs, with total homogenization temperatures (Th-total) of 292.8 to 405.6 °C and salinities of 2.8 to 9.3 wt% NaCl eqv. Quartz from Stage II (main ore stage) developed C2-, C3-, and VL-type FIs, with a Th-total of 278.5 to 338.9 °C and salinities of 2.8 to 8.1 wt% NaCl eqv. Stage III is characterized by coexisting C3- and VL-type FIs in quartz, with a Th-total of 215.9 to 307.3 °C and salinities of 2.4 to 7.2 wt% NaCl eqv. Only VL-type FIs are observed in Stage IV, with a Th-total of 189.5 to 240.4 °C and salinities of 3.7 to 5.7 wt% NaCl eqv. The Laser Raman spectroscopic results demonstrated minor CH4 in the C-type FIs from Stages I and II. The results suggest that ore fluids may have evolved from a medium-high temperature, low-salinity immiscible CO2-NaCl-H2O ± CH4 system to a low temperature, low-salinity homogeneous NaCl-H2O system. Fluid immiscibility caused by the rapid drop in pressure may have been the main trigger for gold-polymetallic sulfide precipitation. The Songjianghe Au deposit may have been formed under 352–448 °C and 850–1380 bar pressure, based on the isochore intersection for Stage II fluid inclusions. The H-O isotopic compositions (Stage I: δ18Ofluid = 5.6 to 5.8‰, δD = −96.2 to −95.7‰; Stage II: δ18Ofluid = 3.7 to 4.2‰, δD = −98.7 to −89.8‰; Stage III: δ18Ofluid = 1.2 to 1.4‰, δD = −103.5 to −101.2‰) indicate that the hydrothermal fluids are dominated by magmatic water in the early stages (Stages I and II) and mixed with meteoric water since Stage III. The pyrite S-Pb isotope data (δ34S: −2.91 to 3.40‰; 206Pb/204Pb: 16.3270 to 16.4874; 207Pb/204Pb: 15.2258 to 15.3489; 208Pb/204Pb: 36.6088 to 36.7174), combined with Pb isotopic compositions of the intrusive rocks and wall rocks (the Seluohe Group) in the ore district, indicate that the ore-forming materials at Songjianghe are predominantly from a magmatic source and may have been affected by the contamination of the Seluohe Group. In accordance with the features of ore geology, ore-forming fluids and metals, and geodynamic setting, the Songjianghe Au deposit belongs to a mesothermal magmatic hydrothermal vein gold deposit, which formed in the intermittent stage of Paleo-Pacific plate subduction during the Late Jurassic. [ABSTRACT FROM AUTHOR]

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We provide an updated overview of the known mineral deposits from the Sila and Serre Massifs in Calabria, contributing to setting their genesis within a complex geologic history, starting from the late-Carboniferous. We summarize the mineralization reported in the literature, with a critical review of the host tectonic units, by taking into account the upgrades in the knowledge of these areas. We also set them in updated geological maps and in stratigraphic columns, highlighting the crustal levels to which they pertain. Despite the geologic and minerogenetic similarities potentially existing with late- to post-Variscan mineral deposits from other regions (e.g., Sardinia and French Central Massif), the scientific literature on the Calabria mineralization is out-of-date and not exhaustive. Moreover, these ore deposits were likely considered not economically attractive enough to stimulate new scientific studies. However, in our opinion, such studies are needed to resolve the main open questions, which rely on deciphering the origin and age of mineralization. Finally, research for critical elements hosted by the Sila and Serre mineralization (e.g., In, Ge and Ga in sphalerites) is a possible interesting new perspective. [ABSTRACT FROM AUTHOR]

The Baiyun deposit is a large gold deposit at the western end of the Liaoji rift zone in Liaoning Province, which has produced both auriferous quartz-vein type and altered-rock type mineralization. The ore bodies are mainly hosted in schist from the Gaixian Formation of the Liaohe Group. A detailed field geological survey showed that the quartz-vein type gold ore bodies are distributed in the near EW-trending and occur in the extensional tectonic space of schist in the Gaixian Formation, and the altered-rock type gold ore bodies are distributed in the near EW-trending structural belt and occur near in the Gaixian Formation of biotite schist, biotite granulite, marble and the upper footwall of dike. To further elucidate the source of ore-forming fluid and material in the Baiyun gold deposit, the H-O isotopes for quartz, S and Pb isotopes, in-situ trace elements for sulfides from quartz-vein and altered-rock type mineralization were studied. The H-O isotopic δDV-SMOW and δ18OH2O values of the auriferous quartz range were from −88.8‰ to −82.2‰ and −1.95‰ to 4.85‰, respectively, suggests that the ore-forming fluids were mainly magmatic water with minor meteoric water. The distribution ranges of in-situ S isotopic compositions of Au-bearing pyrite in the quartz-vein type and altered-rock type ores were −8.38‰–−10.47‰ (with average values of −7.89‰) and 11.38‰–17.52‰ (with average values of 11.55‰), respectively, indicating that the S isotopic compositions of the two ore types were clearly different. The in-situ Pb isotopic ratios changed almost uniformly, which showed that they had the same lead isotopic source. Based on the analysis of S and Pb isotopic compositions, the metallogenic materials in the Baiyun gold deposit were primarily from deep magma, and some wall rock materials may have been mixed in the metallogenic process. Co/Ni diagram shows that most Au-bearing pyrites have magmatic-hydrothermal or sedimentary alteration properties, and Au/As ratios were between 0.001 and 0.828 (the average value was 0.07), indicating that the ore-forming fluid in the Baiyun gold deposit may have been deep magma. Combining the geological, trace element, and isotopic data, as well as data from previous studies, we propose that the Baiyun gold deposit is a magmatic-hydrothermal ore deposit. [ABSTRACT FROM AUTHOR]

Located at the intersection of the Tethys and Pacific Rim metallogenic belts, the Laojunshan polymetallic metallogenic province in SE Yunnan Province hosts many large-scale W–Sn and Sn–Zn polymetallic deposits. The newly discovered Caiyuanzi medium-sized Pb–Zn deposit is located in the northern part of this province and has eight sulfide ore bodies. All the ore bodies occur in the siliceous rocks of the Lower Devonian Pojiao Formation (D1p). The ore bodies are conformable with stratigraphy and controlled by a lithologic horizon. The sulfide ores have banded or laminated structures. The ore minerals are mainly pyrite, chalcopyrite, sphalerite, and galena. In this study, in situ sulfur and lead isotopes were used to constrain the origin of the Caiyuanzi Pb–Zn deposit. The results show that the in situ δ34S values of pyrite, chalcopyrite, and sphalerite range from 0.1‰ to 6.0‰, with an average of 4.7‰. This δ34S signature reflects the mixing between magmatic-derived and reduced seawater sulfate sulfur. The in situ Pb isotopes characteristics of pyrite, galena, and sphalerite suggest that the sulfur and lead of ore minerals come from the upper crust. Integrating the data obtained from the studies including regional geology, ore geology, and S–Pb isotope geochemistry, we proposed that the Caiyuanzi Pb–Zn deposit is a hydrothermal deposit formed by sedimentary exhalative and magmatic hydrothermal superimposition. [ABSTRACT FROM AUTHOR]

[Display omitted] • The Zn-Pb-Ag deposits occupy an important position worldwide. • The Zn-Pb-Ag deposits are rich in various critical metals, such as Ge, Cd, Ga and Tl. • This Special Issue aims to comprehensively understand Zn-Pb-Ag deposits and associated critical metals. • This Special Issue aims promote prospecting of global Zn-Pb-Ag deposits. The combination of zinc (Zn), lead (Pb), and/or silver (Ag) is widely developed in various types of deposits. They also form various types of independent deposits and are associated with a variety of critical metals, such as germanium (Ge), cadmium (Cd), gallium (Ga), and thallium (Tl). The Zn-Pb-Ag deposits make an important group of mineral deposits worldwide, including volcanic-hosted massive sulfide (VHMS), magmatic-hydrothermal-associated skarn and/or epithermal, sedimentary rocks-hosted (e.g., Sedimentary Exhalative, SEDEX; carbonate-hosted epigenetic/Mississippi-Valley-type, MVT; Sandstone/shale-hosted epigenetic, SST), and hydrothermal-vein types. This Special Issue aims to provide a comprehensive understanding of Zn-Pb-Ag deposits and associated critical metals in a variety of geological settings, and promote global prospecting. This Special Issue contains 61 papers (including reviews) covering major Zn-Pb-Ag metallogenic provinces/zones worldwide. The publications provide a comprehensive and systematic analysis including ore deposit geology, geochemistry, geochronology, ore-forming dynamics process and background, big data and deep learning, metallogenic prognosis and ore genesis of Zn-Pb-Ag deposits, as well as the occurrence status and enrichment mechanisms of associated critical metals. These achievements will help to establish more practical mineralization and prospecting models. Equally, they promote the understanding of the genesis of Zn-Pb-Ag deposits, develop new mineralization theory for Zn-Pb-Ag deposits, and provide a theoretical basis for the comprehensive utilization of associated critical metals. [ABSTRACT FROM AUTHOR]

Fluorite is mainly used in the steel and chemical industries. The market demand for fluorite has been growing, and fluorite has become a strategic mineral in China. With the exhaustion of fluorite resources in the main producing areas (Zhejiang, Hunan, etc.), the barite fluorite deposit has been paid more attention and utilized in Wuling Mountain area (the adjacent place of Chongqing, Guizhou and Hunan). Through field geological work, the geological characteristics of shuanghe Barite-fluorite deposit in Wuchuan were studied, it is considered that the Shuanghe Barite-fluorite deposit in Wuchuan is controlled by the lower Ordovician Honghuayuan formation and the NW trending development of tensile fractures, the ore-bearing horizon is the Lower Ordovician Honghuayuan group，It is proposed that the ore-prospecting direction of the barite-fluorite ore body is controlled by the Lower Ordovician Honghuayuan Formation and the NW direction structure, It is helpful for further prospecting work in Wuling Mountain area of Guizhou province, it will actively support the development of mining industry in the region and provide services for poverty alleviation.

To reveal the genesis of Makeng-style iron polymetallic deposits from SE China in the paleo-Pacific tectonic domain, a new analytical method of LA-ICPMS garnet U-Pb dating and rare Earth element analysis was conducted for the Makeng, Luoyang, Dapai and Pantian deposits. The U-Pb dating results of nine garnet skarn samples from these deposits suggested that the Makeng-style iron polymetallic deposits mainly formed during 137–130 Ma, which is consistent with the zircon U-Pb and molybdenite Re-Os ages. This study provides more direct evidence of the mineralization age and the relationship between mineralization and granite, compared with previous studies on the zircon U-Pb dating for granites in the ore fields. Rare Earth element (REE) analysis results and REE patterns of four representative garnet samples from the Makeng, Luoyang, Dapai and Pantian deposits show that they are similar to typical skarn deposits, but obvious differences in the REE distribution types indicate that the ore-forming process may be distinct due to different mineralizing fluid for these Makeng-style deposits. Our new garnet U-Pb dating and rare Earth element analysis result not only provides new evidence for the mineralization age and genesis of the Makeng-style deposits but is also of great significance to promote the application of U-Pb dating methods to research skarn type deposits.

This paper is a scientific overview of studies of accessory cassiterite from rare metal granites, pegmatites, and accompanying greisens in 1990–2021. The earlier and newest data on the morphology, physical and chemical features of accessory cassiterite, and its economic facility are summarized. The consolidated database includes 1759 cassiterite compositions from more than 100 publications. We have confirmed previous and identified new indicator features of cassiterite from rare metal granites, pegmatites, and greisens: concentrations of isomorphous components (Ta, Nb, Fe, Ti, Mn, W, Sc, In, Zr, Hf, U), informative ratios (Nb/Ta, Zr/Hf, Fe/Mn), and main substitution schemes ("tapiolite" and "hydrothermal"). The average trace element content in cassiterite from granites, pegmatites, and greisens is 6.68, 4.87, and 1.18 wt %, respectively. Based on the published data, the solubility limit of tapiolite (Fe,Mn)(Ta,Nb)2O6 in the structure of cassiterite is calculated. These limit is 0.1–11, 0.7–12.8, and 0.1–3.3% in granites, pegmatites, and greisens, respectively. The tapiolite endmember proportion in cassiterite ranges from 0.1 to 12.8%. It is noted that tantalum-bearing cassiterite is predominantly observed in Li–F plumasite granites and LCT lepidolite pegmatites with the high phosphorus concentration over the range of 0.12–2.50 wt % P2O5. The Ta2O5 content in accessory cassiterite reaches 17.9–18.4 wt % and promises additional economic prospects for rare metal pegmatites and granites. Cassiterite can be used as an alternative source of tantalum, indium, niobium, and scandium. Typical occurrences of accessory cassiterite have been identified in granites of the Beauvoir massif (France), in pegmatites of the Peerless (USA) and Varuträsk (Sweden) deposits, and in greisens of the Kester and Polyarnoe deposits (Yakutia). Accessory cassiterite is an advanced mineral geochronometer for rare metal granites and pegmatites, since it is not susceptible to radiation damage and disruption of the U–Pb isotope system. [ABSTRACT FROM AUTHOR]

Trace elements in quartz reflect the physio-chemical conditions of growth of the mineral and are also capable of tracing the evolution history of the associated ore-forming fluid, and are therefore a potential discrimination signature for different styles of ore genesis. In this study, we compile data on quartz trace elements from 25 porphyry, pegmatitic, greisen, skarn, epithermal, Carlin and Mississippi Valley type (MVT) deposits. Trace elements that relate to the Si4+ substitution types and precipitation conditions of quartz, such as Li, Al, Na, P, K, Ti, Fe and Ge, have been chosen to plot different geochemical diagrams. The quartz Ti vs. Al/Ti, Al vs. Al/Ti and Ti–10Ge–Al/50 diagrams reveal the evolution of the hydrothermal fluids in different types of ore deposits. The results confirm that Ti4+ incorporation into quartz is generally related to temperature variation, whereas Al3+ incorporation is more likely controlled by pH fluctuation. The trace element compositions of quartz from porphyry, greisen, pegmatitic, skarn, epithermal, Carlin and MVT deposits are distributed along a C-shape curve in the Ti–10Ge–Al/50 diagram, which is consistent with temperature decrease. In addition, there are different independent partitions in the Ti–P–Na geochemical source discrimination diagrams, which potentially discriminate the quartz from porphyry, pegmatitic, greisen, skarn, epithermal and Carlin type of deposits. This study shows that quartz trace elements can be used as a useful proxy for tracing the evolution of the hydrothermal fluids in different types of ore deposits and are also a useful auxiliary tool to discriminate different modes of ore genesis. [ABSTRACT FROM AUTHOR]

A microtomographic study of the internal structure of sulfide minerals from the ore-bearing rock varieties of two economically significant deposits in the Arctic zone of the Russian Federation, disseminated ore of the Pilgujarvi Cu–Ni deposit (Pechenga) and metalliferous gabbronorites of the platinum-bearing Fedorovo–Pansky complex (Kola Peninsula), was carried out. It was shown that all sulfide samples studied had a homogeneous structure without obvious defects or silicate inclusions larger than 1 µm. The absence of silicate microinclusions larger than one micron in sulfides testifies to the isomorphism of rare earth element (REE) occurrence in sulfides and eliminates, to a certain extent, the debatable problem of the influence of microinclusions on the results of Sm–Nd isotope-geochronological studies of sulfides. The presence of smaller (10–500 nm) silicate microinclusions is, with a high degree of probability, unable to control the total REE budget in a sulfide mineral. The conclusion of the absence of a significant effect of microinclusions on the obtained ages is confirmed by the results of Sm–Nd dating using sulfides from the same mineral aliquots: the Sm–Nd ages of the ores of the Pilgujarvi Cu–Ni deposit were estimated at 1965 ± 87 Ma; and the ore-bearing gabbronorites of the Fedorovo-Pansky complex, at 2482 ± 61 Ma. This agrees well with the datings obtained earlier using other isotopic systems (U–Pb, Re–Os). [ABSTRACT FROM AUTHOR]

Haerdaban is a newly discovered Zn–Pb deposit (0.64 Mt at 6.19 wt% Zn and 1.09 wt% Pb) in the Western Tianshan, NW China. Sulfide mineralization mainly occurs as veins, breccias, and semi-massive ores within the dolomitic limestone and calcareous slate. Here we use Rb–Sr sphalerite and SHRIMP U–Pb zircon geochronology to place constraints on the age and formation of the deposit. Rb–Sr dating of sphalerite gives an isochron age of 432 ± 45 Ma (n = 6; 87Sr/86Sri = 0.7102 ± 0.0020), providing a direct age constraint for the main mineralization. SHRIMP U–Pb data for detrital zircon from three samples of host siliceous dolomite have relatively similar age modes with prominent age peaks at 1576 Ma, 1781 Ma, and 1848 Ma, and a smaller peak at 1375 Ma. The maximum depositional age for the host dolomite is constrained at 1099 ± 21 Ma by the weighted mean age of the four youngest detrital zircons. These results demonstrate that the main mineralization clearly postdates the host sedimentary rocks. Zircons from two diorite samples and one granite sample yield overlapping 206Pb/238U ages with a weighted mean of 394.5 ± 1.5 Ma. This age is slightly younger but within analytical uncertainty of the 432 ± 45 Ma for the ores, implying a possible temporal relationship between intrusions and main mineralization. The igneous intrusions could provide the heat to drive the hydrothermal system responsible for main-stage mineralization. Haerdaban is interpreted to be a metamorphosed SEDEX Zn–Pb deposit that has been remobilized by subsequent hydrothermal activity. [ABSTRACT FROM AUTHOR]

Jiaodong is the largest gold deposit concentration area in China. In recent years, great breakthroughs have been made in deep prospecting, and it has become the third largest concentration area of gold deposits in the world. A series of prospecting discoveries in the Jiaodong area provided the basic conditions for summarizing the regional metallogenic law, constructing the deposit model, carrying out research on the genesis of the deposit and innovating metallogenic theory. The Jiaodong gold deposits are mainly distributed in Northwest Jiaodong, Qi-Peng-Fu and Mu-Ru metallogenic regions, and mainly occur in Precambrian metamorphic rock series, Jurassic Linglong-type granite, Early Cretaceous Guojialing-type granite and Laiyang group. The orebodies are controlled by Sanshandao, Jiaojia, Zhaoping, Xilin-Douya, Jinniushan and other major ore-controlling fault zones. The main mineralization types include altered rock-type, quartz vein-type, stockwork type, sulfide quartz vein-type, interlayer detachment zone-type, altered conglomerate-type, basin margin fault breccia-type and pyrite carbonate vein-type and so on. The important progress of deep prospecting is summarized: two super giant deposits have been evaluated in the Sanshandao and Jiaojia areas; the amount of altered rock-type gold resources identified by deep prospecting has exceeded that of quartz vein-type gold deposits in the Linglong gold deposit field; the Hushan large scale gold deposit has been discovered in Qixia gold deposit field; and the Liaoshang large-size gold deposit is a new discovery of deep prospecting in Pengjiakuang gold deposit field. The ore-controlling faults of gold deposits have several changing steps with dip angle varying from steep to gentle along the dip angle. The gold ore bodies are mainly enriched in sections along the steep, gentle turning points and relatively gentle parts of the fault dip angle, forming a stepped distribution pattern. In the Early Cretaceous, the subduction and rollback of the Paleo-Pacific plate induced crust mantle interaction, resulting in large-scale magmatic and fluid activities. The crust tension and magma uplift form the dome extension structure of granite, which provides a channel for the migration of ore-forming fluid and also provides favorable space for the deposition of ore-forming fluid.

The Toudaochuan gold deposit is a recently discovered lode gold deposit in Central Jilin Province. Gold ore bodies are dominantly controlled by NE-trending fault. The major hydrothermal period can be further divided into the quartz–pyrite stage (stage I), quartz–gold–polymetallic sulfides stage (stage II, major gold mineralization stage), and quartz–carbonate stage (stage III). Primary fluid inclusions (FIs) identified in quartz at different hydrothermal stages include liquid-rich aqueous FIs (L-type), CO2 FIs (C-type, including CO2-bearing C1-type FIs and CO2-rich C2-type FIs), and minor vapor-rich aqueous FIs (V-type). Microthermometry studies on different fluid inclusions indicate that the original ore-forming fluids belonged to the CO2–H2O–NaCl system characterized by a moderate–low temperature and low salinity in stages I and II, and they finally evolved into a H2O–NaCl system characterized by low temperature and low salinity in stage III. Fluid immiscibility is considered to be the key ore-forming mechanism. The initial ore-forming fluid was originated from magmatic water and was mixed with meteoric water in the later stage. The S and Pb isotope data suggest that the ore metal materials were derived from the mixed source of mantle and crust. Based on all the above data, therefore, it can be proposed that the Toudaochuan gold deposit is a mesothermal magmatic–hydrothermal gold deposit. [ABSTRACT FROM AUTHOR]

The Mesoproterozoic North American Midcontinent Rift hosts the world's largest accumulation of native copper in Michigan's Keweenaw Peninsula. During a regional metamorphogenic-hydrothermal event, native copper was deposited along with spatially zoned main-stage minerals in a thermal high. This was followed by deposition of late-stage minerals including minor copper sulfide. Inferences from the oxygen and carbon isotopic composition of main-stage hydrothermal fluids, as calculated from 296 new and compiled isotopic measurements on calcite, are consistent with existing models that low-sulfur saline native copper ore-forming fluids were dominantly derived by burial metamorphic processes from the very low sulfur basalt-dominated rift fill at depth below the native copper deposits. Co-variation of oxygen and carbon isotopic compositions are consistent with mixing of metamorphic-derived fluids with two additional isotopically different fluids. One of these is proposed to be evolved seawater that provided an outside source of salinity. This fluid mixed at depth and participated in the formation of a well-mixed hybrid metamorphic-dominated ore-forming fluid. Secondary Ion Mass Spectrometry in-situ isotopic analyses of calcite demonstrate a high degree of variability within samples that is attributed to variable degrees of shallow mixing of the hybrid ore-forming fluid with sulfur-poor, reduced evolved meteoric water in the zone of precipitation. The oxygen and carbon isotopic compositions of 100 new and compiled measurements on late-stage calcite are mostly isotopically different than the main-stage hydrothermal fluids. The late-stage hydrothermal fluids are interpreted as various proportions of mixing of evolved meteoric water, main-stage hybrid ore-forming fluid, and shallow, evolved seawater in the relatively shallow zone of precipitation. [ABSTRACT FROM AUTHOR]

The Huayuan Pb‐Zn ore district in China, located in western Hunan Province, is a giant carbonate‐hosted Pb‐Zn ore district. The source of ore‐forming brines in this ore district remains poorly constrained. Whether the highly saline brines are derived from evaporated seawater or dissolved evaporates continues to be intensely debated. Carbonate minerals associated with Pb‐Zn mineralization have δ13CV‐PDB and δ18OV‐SMOW values ranging from −5.55‰ to +1.35‰ (mean value of −0.69‰; n = 14) and +16.28‰ to +25.05‰ (mean value of +20.22‰; n = 14), respectively. This indicates that carbonate minerals are dominantly formed from dissolved ore‐hosted carbonate rocks. The δ34S values of sulfides range from +20.2‰ to +36.8‰, with an average value of +30.0‰ (n = 27). These results suggest that sulfur is predominantly derived from the thermochemical sulfate reduction of marine sulfate. The crush‐leach analyzed solute data of fluid inclusions in sphalerite show the ore‐forming fluids have Cl/Br molar ratios range from 118 to 384, and Na/Br molar ratios from 39 to 160 (n = 8). These Cl/Br ratios of hydrothermal fluid are much lower than those of seawater (657 to 564), but are consistent with bittern brines through early halite precipitation. We propose that ore‐forming fluids are mainly derived from evaporitic basin brines, which leached base metals from the basement and/or country rocks. The brine then migrated to the basin margins through clastic rocks of basement and then precipitated sulfides by thermochemical sulfate reduction. [ABSTRACT FROM AUTHOR]

BACKGROUND The Xuebaoding deposit, located in the Songpan-Ganzi orogenic belt, Sichuan Province, is famous for coarse-grained W-Sn-Be-F-P-bearing minerals. Many studies have been carried out on this deposit, but there is a lack of research on major and trace elements of coarse-grained minerals. OBJECTIVES To obtain major and trace element composition of minerals and provide constraints on ore genesis of the Xuebaoding deposit. METHODS In this study, X-ray fluorescence spectrometry (XRF) and electron probe microanalysis (EMPA) were used to analyze the major elements of minerals in the deposit, and the trace elements were analyzed by inductively coupled plasma mass spectrometry (ICP-MS). RESULTS The results showed that beryl, scheelite, cassiterite, muscovite, fluorite, apatite and tourmaline in the Xuebaoding deposit were rich in major ore-forming elements (W, Sn, Be, Na, K, Ca) and alkali metal elements such as Li, Rb, Cs, and volatiles such as F, B, and P. Beryl in the Xuebaoding deposit was rich in Li (3484-4243μg/g), Rb (39.3-71.1μg/g) and Cs (2955-3526μg/g). The content of Li, Rb and Cs in muscovite was as high as 4243μg/g, 72.3μg/g and 3526μg/g, respectively. The content of F in apatite and B in tourmaline were 4.48%-5.21% and 30990-32880μg/g, respectively. The granites in the Xuebaoding deposit were relatively rich in W, Sn, Be, Li, Rb, Cs, F, B, P, with relatively low CaO content (0. 46%-0. 82%). Li, Rb, Cs, F, B, P were conducive to the enrichment of ore-forming elements in fluids. Marble in the mining area was calcite marble, which provided a large amount of Ca for mineralization and was conducive to the large-scale precipitation of coarse-grained minerals. CONCLUSIONS W, Sn, Be, Li, Rb, Cs, F, B and P in coarse-grained minerals are mainly derived from magmatic fluids, where the marble strata provide a large amount of Ca for coarse-grained minerals.

Human activities have led to a considerable increase in trace metal cycling in recent times. The mobilized elements get subjected to a variety of processes leading eventually to their re-concentration. The polluted sites, transformed by Earth's surface processes, become similar to metal accumulations known from geological records. This study examines authigenic metal sulfide mineralization in two peatlands polluted by atmospheric deposition from a nearby Pb-Zn smelter. We use the polluted peatlands as a small-scale model of Zn-Cd-Pb sulfide deposit to determine the role of organic matter in ore genesis and the textural and structural organization of biogenic precipitates. The study shows that the air-derived metal enrichment (up to 2.3 g Zn kg−1, 1.1 g Pb kg−1, and 62 mg Cd kg−1) is retained in a thin layer (∼30 cm) around 10–15 cm below the peat surface. A combination of focused ion beam (FIB) technology and scanning (SEM) and transmission (TEM) electron microscopy reveals that micrometric spheroids are most characteristic for ZnS and (Zn,Cd)S, although the sulfides readily form pseudomorphs after different plant tissues resulting in much larger aggregates. The aggregates have a complex polycrystalline sphalerite structure much more advanced than typically obtained during low-temperature synthesis or observed in other modern occurrences. Platy highly-disordered radially-aggregated submicrometre crystals develop within the time constraints of several decades in the cold (∼15 °C) and acid (pH 3.4–4.4) peat. The less abundant Pb sulfides occur as small cube-like crystals (<1µm) between ZnS or as flat irregular or square patches on plant root macrofossils. All PbS are crystalline and defect-free. Pb ion complexation with dissolved and solid organic matter is probably responsible for the low number and equilibrium shape of PbS crystals. Iron is absent in the authigenic sulfide mineralization and occurs entirely as organically bound ferric iron (Fe3+), as revealed by Mössbauer spectroscopy. The different affinity of metals to organic matter enhances the precipitation of Zn and Cd as sulfides over Pb and Fe. Our findings demonstrate that human activities lead to the formation of near-surface stratiform metal sulfide accumulations in peat, and the polluted sites can be of use to understand and reconstruct ancient ore deposits' genesis and mechanisms of formation. [ABSTRACT FROM AUTHOR]

The Cishan gold deposit is a newly discovered medium-scale independent skarn gold deposit located in the Tongling ore cluster area of the Middle-Lower Yangtze Metallogenic Belt, and the ore-related intrusion is the Cishan pyroxene diorite. In this study, we investigated the zircon U–Pb Geochronology, whole-rock geochemistry of the Cishan ore-related pyroxene diorite, and C–O–S isotope compositions of hydrothermal calcites and metal sulfides in the ores. The pyroxene diorite was emplaced at ca. 141.7 ± 0.36 Ma. They are metaluminous and record high-K calc alkaline and shoshonite series with the characteristics of high Al and alkali (K, Na), enriched in LREEs and LILEs (Rb, K, Ba, Sr), depleted in HREEs and HFSEs (Th, U), without significant Eu anomalies. We suggest that the magma of the Cishan pyroxene diorite was probably derived from partial melting of the enriched lithospheric mantle mixed with a small amount of crustal derived melts, and then underwent crystallization differentiation and weakly upper crustal contamination during the magmatic ascending. The δ13CV-PDB and δ18OV-SMOW values of the hydrothermal calcites range from −5.1‰ to −0.5‰ and 11.7‰ to 16.2‰ respectively, and the δ34SV-CDT values of sulfide ore minerals range from −0.7‰ to 6.0‰, showing that the ore-forming fluids and materials were derived from the magma. Combined with previous studies, we proposed that both the Cishan intrusion and skarn gold deposit were formed under the tectonic transition period from compressional to extensional setting, and the Middle–Lower Yangtze Metallogenic Belt was located in the inland side of the continental margin arc under the subduction of the paleo-Pacific plate.

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[Display omitted] • The Hajibolagh-Zalibolagh Cu-(Ag) deposit is hosted by the Eocene volcano-sedimentary sequence. • Fault-controlled sulfides occur with silicification, sericitization, and intermediate argillic alteration types. • pH increases due to boiling, dilution, and mixing causes Cu-Ag saturation. • Hajibolagh-Zalibolagh is an intermediate-sulfidation Cu-(Ag) epithermal system from Saveh, UDMA, Iran. The Hajibolagh-Zalibolagh deposit located northeast of the city of Saveh in the central part of the Urumieh-Dokhtar magmatic arc of Iran, demonstrates vein and breccia vein style copper-(silver) mineralization hosted by Eocene volcano-sedimentary rocks. The main mineralization stage can be divided into four phases, respectively (1) jasperoid + quartz veins, chalcopyrite, and pyrite; (2) quartz veins along with chalcopyrite, bornite, chalcocite, arsenopyrite, and pyrite; (3) quartz-barite veins along with chalcopyrite, bornite, chalcocite and pyrite; and (4) veins of quartz, calcite, hematite, and oligist along with a small number of copper sulfides. The main stages of mineralization are cut by barren post-ore quartz and calcite veinlets. As a result of supergene processes, minerals are oxidized, and malachite, azurite, chrysocolla, chalcocite, covellite, goethite, and hematite are formed, presenting an important exploration guide. The hydrothermal alteration from the center of the vein-veinlets to the outside includes, respectively, silicification, sericitization, intermediate argillic, and propylitic. The average salinity and homogenization temperature (T h) of fluid inclusions is 14.2 wt% NaCl equiv. and 288 °C, respectively. The coexistence of the vapor phase, liquid-rich phase, and halite-bearing fluid inclusions is a sign of boiling in this hydrothermal system, which has contributed to copper saturation. Sulfur isotope values for pyrite, chalcopyrite, chalcocite, and bornite are mainly from –0.16 to 2.98 ‰, indicating a probable magmatic source for sulfur. Boiling, dilution, and mixing are the mechanisms for the ore deposition and facilitated the mineralization. The Hajibolagh-Zalibolagh deposit shows the highest similarity to intermediate-sulfidation epithermal deposits. The best environment for the mineralization and fluid circulation in these epithermal deposits is the intersection of faults with the Eocene volcanic and volcano-sedimentary rocks. [ABSTRACT FROM AUTHOR]

[Display omitted] • LA–ICP–MS analysis of individual fluid inclusions from the Jinman sediment-hosted vein-type Cu deposit was performed. • The ore fluids in the Jinman deposit were metamorphic in origin. • The Jinman deposit has many similarities to orogenic Au deposits worldwide and thus can be thought of as an orogenic deposit. • Implications for global metallogeny and exploration of this type of deposits were highlighted based on the compiled data. Sediment-hosted Cu deposits, including stratiform and epigenetic vein-type Cu deposits, are the second largest source of Cu worldwide. However, many facets of these vein-type Cu deposits, such as the nature and origin of ore fluids and geodynamic mechanisms that produced these fluids, remain controversial, limiting our interpretations of the ore genesis and hampering the selection of exploration strategies. Numerous sediment-hosted vein-type Cu deposits are present in the Lanping Basin, SW China, of which the Jinman deposit is the largest. Copper orebodies at Jinman consist of Cu-sulfide–quartz–carbonate veins and altered wall-rocks hosted mainly in faults and fracture zones in metamorphosed and deformed clastic rocks. The deposit was formed in three stages, pre-, syn- and post-ore, with the first two stages producing hydrothermal veins. The veins in pre-ore stage consist of quartz + ankerite ± sericite ± pyrite, whereas those in syn -ore stage consist of Cu-sulfides + quartz + carbonate ± sericite. During the syn -ore stage, tennantite, quartz, and ankerite crystallized early, then bornite was precipitated, followed by chalcopyrite and chalcocite and finally calcite. Only minor sericite was formed during the post-ore stage. Two major types of fluid inclusions—CO 2 -rich and aqueous inclusions—are present in both pre- and syn -ore quartz, whereas only aqueous inclusions are present in syn -ore calcite. In pre- and syn -ore quartz and calcite, CO 2 -rich inclusions have higher homogenization temperatures (275–323 °C) and pressures (307–3495 bar) and lower salinities (0.22–2.7 wt% NaCl eqv.) than aqueous inclusions (164–299 °C, 6.5–80.4 bar and 3.7–20.9 wt% NaCl eqv.). However, the small variations in Cs/Na and Cs/(Na + K) ratios [log Cs/Na = –3.3 ∼ –1.9, log Cs/(Na + K) = –3.3 ∼ –2.1] of the fluid inclusions suggest a same source for the ore fluids. We propose that during both stages, CO 2 -rich inclusions resulted from unmixing of initial deep-seated, single-phase CO 2 -rich fluids, whereas aqueous inclusions likely represent the fluids that evolved from these unmixed fluids by extensive CO 2 degassing. This interpretation, combined with microthermometric results of CO 2 -rich inclusions, suggests a mesothermal, low-salinity H 2 O–NaCl–CO 2 ore fluid system. The fluid inclusions from Jinman have similar compositions to those of metamorphic fluids, suggesting a metamorphic origin for the ore-forming fluids. The evolution of fluid compositions suggests that fluid degassing likely acted as a major mechanism for Cu precipitation. We propose that the ore fluids were generated through metamorphic devolatilization of basement of the Lanping Basin in the Biluoxueshan–Chongshan metamorphic zone under a compressional or transpressional regime caused by Cenozoic India–Asia collision. The Jinman deposit has many similarities to orogenic gold deposits worldwide and thus can be thought of as an orogenic deposit. Based on a compilation of the geological characteristics of global sediment-hosted epigenetic vein-type Cu deposits, we suggest that other sediment-hosted epigenetic vein-type Cu deposits with similar genesis to the Jinman deposit are likely present in other regions worldwide. This highlights the exploration potential of this type of deposit in these regions and the need for further research. [ABSTRACT FROM AUTHOR]

[Display omitted] • Two generations of sphalerite were identified in the Ashele Cu-Zn ores. • The ore-fluid evolution at Ashele is recorded by sphalerite geochemistry. • Sulfur isotopes show a magma and TSR-derived sulfur source. • Sulfide geochemistry has the potential to guide mineral exploration. The Ashele Cu-Zn deposit is one of the largest and most typical VMS-type Cu-Zn deposits in the Chinese Altai Mountains, Central Asian Orogenic Belt. The ore-forming processes of the Ashele deposit remains elusive, with particular uncertainties surrounding the physicochemical conditions underpinning their formation. In this study, major and trace element concentrations of the two types of sphalerite and sulfide sulfur isotopic compositions have been analyzed to constrain the mineralization conditions and ore genesis. Two stages of sphalerite have been identified, i.e., euhedral sphalerite of the early Cu mineralization stage (Sp1) and anhedral sphalerite of the late Zn mineralization stage (Sp2). Results show that Sp1 has relatively higher contents of In, Cu, Sn, and Hg, but lower levels of Cd, Ga, Ge, As, and Ag compared to that of Sp2. Utilizing the sphalerite GGIMFis geothermometer, mineralization temperatures for Sp1 and Sp2 were estimated at 225-296°C (average 258°C) and 166-264°C (average 210°C), respectively. Additionally, the Ashele sphalerite geochemistry suggests a relatively high sulfur fugacity during ore formation (l g f S 2 = −8.99 to −6.55 for Sp1 and −13.58 to −6.83 for Sp2). The findings suggest an evolutionary trend of ore-forming fluids, characterized by a decrease in both temperature and sulfur fugacity from the early Cu mineralization stage to the later Zn mineralization stage. In situ δ34S values of sulfides (sphalerite, chalcopyrite, and pyrite) range from 0.84 ‰ to 6.07 ‰, indicating a sulfur origin from the thermochemical reduction of seawater sulfate and leaching of the underlying volcanic rocks, with a minor contribution from direct gas release from shallow magma chambers. Overall, this work unravels the physicochemical transformation between the two identified mineralization stages, thereby enhancing the understanding of the ore-forming process of the Ashele deposit. [ABSTRACT FROM AUTHOR]

The Hongguleleng Cu deposit is a Manto-type deposit in the Central Asian Orogenic Belt, located in the east section of West Junggar, Xinjiang, China. It is hosted by Middle Ordovician volcano-sedimentary sequence, especially for porous units. Specifically, the orebodies of this Manto-type deposit are hosted in basalt, andesite, and andesitic breccia host rocks (the particular volcano-sedimentary sequence). The occurrence of these orebodies is controlled by normal faults. Chalcopyrite, pyrite, calcite, chlorite, and epidote are most common minerals of the Hongguleleng deposit. Three alternation belts and six ore related stages have been recognised. The epidote-chalcopyrite stage, quartz-calcite-chalcopyrite stage, and chlorite stage are ore forming stage. The δ34S of chalcopyrite in ore depositing stages varies from 0.94‰ to 2.59‰, indicating that the origin of sulfur is either magma or host volcanic rock. Further, the 206Pb/204Pb, 207Pb/204Pb, and 208Pb/204Pb values of the chlorite-chalcopyrite and quartz-calcite-chalcopyrite stages exist in the range of 17.443–17.847 and 17.855–17.973; 15.472–15.495 and 15.493–15.620; and 37.616–37.666 and 37.689–38.114, respectively, indicating that the metal originates from the Middle Ocean Ridge Basalt (MORB). The δ13CPDB value of calcite for the epidote-chalcopyrite stage ores, quartz-calcite-chalcopyrite ores with veinlet characteristics, quartz-calcite-chalcopyrite ores with brecciated characteristics, and chlorite-chalcopyrite ores range from −1.40 to −1.50‰, −2.01 to 0.41‰, −1.15 to 0.75‰, and −0.80 to 1.58‰, respectively, while the 18OSMOW ranges from 8.94–10.42‰, 11.83–13.17‰, 13.59–14.04‰, and 12.34–14.18‰, respectively. The CO isotope of calcite of the Hongguleleng deposit indicates that seawater is an essential fluid for ore formation and that modified seawater interacts with the host rock extensively. The hydrothermal magnetite in the quartz-magnetite stage and chlorite in the ore forming stages indicate that temperature decreases from its early to late stages. High Zn and Pb concentrations over four stages of pyrite, with a relatively stable contents, indicate that the content of Zn and Pb in fluid is also high. The concentration of Cu in these four stages of pyrite of the Hongguleleng deposit follow a decreasing trend, indicating that the concentration of Cu in the ore forming fluid decreases from the early to late stage. Based on information mentioned above, we argue that this deposit is a Manto-type deposit with modified seawater driving forces.

The Shuitoushan Pb–Zn deposit, which is located in the southern Baoshan Block of Sanjiang region, SW China, forms an important part of the Luziyuan polymetallic ore field. The origin of ore‐forming fluids and the genesis of this deposit are rarely reported. In this study, we present the results of geological features, fluid‐inclusion and isotopic (O, S, Pb) analyses of the Shuitoushan deposit. The mineralization process of this deposit can be divided into three stages: pyrite‐quartz stage (Stage I), sphalerite‐galena‐chalcopyrite stage (Stage II), and chalcopyrite‐calcite stage (Stage III), with a relatively medium‐low temperature (their homogenization temperatures ranging from 261 to 340°C, 219 to 300°C, and 159 to 225°C, respectively) and low salinity (their salinities varying from 2.1 to 6.8 wt% NaCleqv., 1.2 to 4.9 wt% NaCleqv. and 0.7 to 3.85 wt% NaCleqv., respectively), as revealed by microthermometry study of three types of fluid inclusions, namely L‐type (liquid‐rich), V‐type (vapor‐rich), and PL‐type (pure liquid), distinguished in ore‐bearing quartz veins. The decline of δ18OH2O values (decreasing from 7.58‰ in early stage to 0.08‰ in late stage) of the mineralizing fluid indicates an initial magmatic water source of it, with a gradually increasing input of meteoric water during the process of evolution. The ore‐forming materials are likely to be mainly derived from the concealed intermediate‐acid intrusions and also wall rocks, as suggested by the δ34S values (4.1–12.2‰) and Pb isotope compositions (206Pb/204Pb = 18.325–18.448, 207Pb/204Pb = 15.806–15.944, 208Pb/204Pb = 38.822–39.439) of sulphides in ores. Above all, the Shuitoushan deposit can be classified as an epithermal Pb–Zn deposit. This study also indicates that the Pb–Zn polymetallic deposits in the Luziyuan ore field have similar ore‐forming fluids and materials sources, the distribution and mineralization process of which are controlled by the concealed intermediate‐acid intrusion at depth in Luziyuan, Wumulan, and Shuitoushan areas. [ABSTRACT FROM AUTHOR]

The Erdaogou gold deposit is located in the conjuncture of North China Carton and Xingmeng orogenic belt. The ore-forming process of Erdaogou gold deposit is divided into three stages (I to III), which are quartz-pyrite stage (stage I), quartz-polymetallic sulfide stage (stage II) and quartz-calcite stage (stage III). Two types of fluid inclusions is distinguished in the ore-forming stage, i.e., aqueous type (W-type) and aqueous-carbonic type (C-type) inclusions. From the stage I to III, the homogenization temperature of fluid inclusions are respectively 334–395, 214–364 and 172–272 °C, with salinities of 7.72 wt.%–11.23 wt.% NaCl equiv., 0.20 wt.%–23.18 wt.% NaCl equiv., and 0.35 wt.% to 5.25 wt.% NaCl equiv. The ore-forming fluids of the Erdaogou deposit have the characteristics of medium-low temperatures, moderate salinities and low densities. And the fluids belong to the CO2-H2O-NaCl system. The values of δ34SV-CDT in sulphide samples at different stages (stages I to III) are between −2.2‰ to 2.3‰, indicating sulfur source from magma volatiles or subvolcanic rock leaching. The lead isotopes suggest that ore-forming metals may be derived from a mixture of lower crust and mantle materials. Oxygen and hydrogen isotope data at Erdaogou indicate that magmatic fluid and meteoric water may both be involved in the hydrothermal system. Based on the geological characteristics, fluid inclusion results, stable and radiogenic isotope results of Erdaogou gold deposit, we believe that the temperature decrease, fluid boiling are the key factors leading to the ore precipitation and the genetic type of Erdaogou gold deposit is low-sulfidation epithermal deposit. [ABSTRACT FROM AUTHOR]

The Daqingshan gold deposit, located in the Beishan orogenic belt, northwestern China, is hosted in a Carboniferous greenschist facies metavolcanic-sedimentary sequence. Three periods of metamorphic and deformational events were recognized, corresponding with the three types of quartz veins in the deposit area. Quartz veins formed in the second period (D2) are the main auriferous ones that are strictly controlled by the subsidiary structures of the Kuluke shear zone. Gold mineralization occurs both as quartz veins and as enveloping altered wall rocks. Native gold, pyrite, and arsenopyrite are the primary ore minerals, while quartz and sericite are the main gangue minerals. Wall-rock alteration predominantly consists of silicification, sericitization, arsenopyritization, and pyritization. Systematic fluid inclusion investigation shows that CO2-H2O three-phase inclusions are the dominant type of fluid inclusions in the auriferous quartz veins, suggesting that the ore-forming fluids belong to a CO2-H2O ± CH4 ± N2 system that is particularly rich in CO2. The ore fluids are characterized by medium to high temperature (230~380 °C), low salinity (2~8% NaCleqv.), and medium density (0.8~0.9 g/cm3). Oxygen isotopes (δ18Ofluid = 11.3‰ to 13.9‰) indicate that the ore-forming fluids were most likely derived from metamorphic water. Fluid immiscibility might be the critical mechanism leading to the deposition of gold. The U-Pb dating results of hydrothermal zircons from auriferous quartz veins indicated that the maximum timing of the gold mineralization at Daqingshan was 295 Ma, the Early Permian. Comprehensive studies suggest that the Daqingshan deposit is a typical orogenic gold deposit formed during the subduction-accretionary phase of the Beishan orogenic belt. Significantly, recognizing the ore genesis of the Daqingshan gold deposit has an important implication for deep and regional mining exploration of southern Beishan. [ABSTRACT FROM AUTHOR]

Dulong Sn Zn polymetallic super large ore deposit in Yunnan province is an important tin resource base in China?associated with lead，silver，copper，iron，indium and cadmium. In view of the metallogenesis and genetic mechanism of the ore deposit，the ion chromatography and gas chromatography analysis of fluid inclusions were carried out with gangue minerals as the research object，and the gas and liquid phase components of fluid inclusions in quartz?calcite and fluorite were identified. The results show that the gas phase compositions of fluid inclusions in quartz are mainly CO2 and H2O? followed by N2. The gas phase compositions of fluid inclusions in calcite are mainly CO2，H2O and N2，with a small amount of H2， The liquid phase compositions of fluid inclusions are relatively rich in Na+，Ca2+ and Cl_，but F- content is relatively low. The nitrogen in the fluid may come from the decomposition of organic matter and silicate minerals bearing potassium in the granite, and the gaseous components such as CO2 may involve in the mineralization. The ore-forming fluid is a weak acid and reductive solution rich in Cl and poor in F and can combine with metal mineral cations to form complex, which Is helpful for metal migration. The formation of the ore deposit may have undergone two stages: water-rock reaction in the early and middle stage, rainwater mixing and mineral precipitation in the middle and late stage, and magmatic hydrothermal superimposition in the late metallogenic stage. [ABSTRACT FROM AUTHOR]

The Jiangshan gold deposit is the largest, most recently‐discovered gold deposit in the Bengbu Uplift. The ore bodies are located in the structural fracture zone of the Zhuangzili Formation (Ar3), with major Pb‐Zn and Au reserves. In this study, LA‐ICP‐MS zircon U‐Pb analyses yielded a crystallization age of 111.5 ± 1.8 Ma for the quartz diorite porphyry in Jiangshan. The quartz diorite porphyry has high Ba and Sr content, with low Y and Yb content, which is similar to the characteristics of adakitic rocks. They are enriched in large ion lithophile elements (LILEs, e.g., Ba, U) and light rare earth elements (LREEs), while depleted in high field strength elements (HFSEs, e.g., Nb, Ti) and heavy rare earth element (HREEs). They have zircon ∊Hf(t) values of –23.52 to –21.14 (mean = –22.32). and Hf model ages of 2419.76 to 2569.39 Ma. The magma source area is the lower crust. Magma primarily came from the partial melting of the lower crust, with the addition of some mantle material. The quartz diorite porphyries are characterized by high zircon TTi‐in‐zircon values (608–757°C), Ce4+/Ce3+ ratios (71.97–1387.10) and Eu/Eu∗ ratios (0.46–1.08), indicating high temperature and magmatic oxygen fugacities. High temperatures can provide heat to fluids and highly oxidized magmas can control the behavior and speciation of sulfides, thus controlling the behavior of Au. Finally, the ore‐forming fluid is enriched and precipitated in a favorable structural space to form the Jiangshan Au deposit. [ABSTRACT FROM AUTHOR]

The Maoping Pb–Zn deposit (~ 3 Mt Pb + Zn reserves with grades of 12–30 wt%) is one of the largest Pb–Zn deposits in the Sichuan–Yunnan–Guizhou (SYG) metallogenic province, which has contributed a tremendous amount of lead and zinc resources for China. To obtain a further understanding of the sources of ore-forming materials and ore genesis of the deposit, S–Pb isotopes of sulfides and C–O isotopes of ore-stage calcites were systematically collected from representative orebodies at different elevations with a Finnigan MAT-253 mass spectrometer. The calcites separated from the sulfides of the No I and No II orebodies shared identical δ13CPDB values (− 5.3 to − 0.8 ‰) and δ18OSMOW values (+ 14.5 to + 21.8 ‰) with those of the calcites in the SYG region, suggesting that CO2 in regional ore-forming fluids possibly had a homologous C–O source that originated from a ternary mixture of the dissolution of marine carbonate rocks, degassing process of the Emeishan mantle plume, and dehydroxylation of sedimentary organic matter. The No. I-1 and No. I-2 orebody was hosted in the same strata, but the sulfur source of No. I-1 orebody (+ 13.1 to + 19.0 ‰) with equilibrated sulfur fractionation (δ34Ssphalerite < δ34Sgalena) and No. I-2 orebody (+ 18.0 to + 21.8 ‰) with sulfur equilibrium fractionation (δ34Ssphalerite > δ34Sgalena) were different. They were derived from the allopatry thermochemical sulfate reduction (TSR) of overlying Carboniferous sulfates in the ore-hosting strata and local TSR of sulfates in the ore-bearing Upper Devonian Zaige Formation, respectively. The narrow and uniform Pb isotopic ratios of single galena grains collected from sulfides with 206Pb/204Pb of 18.713–18.759, 207Pb/204Pb of 15.772–15.776 and 208Pb/204Pb of 39.383–39.467 indicate a well-mixed metal source(s) that consist of Proterozoic Kunyang and Huili Group basement rocks and Devonian to Middle Permian ore-hosting sedimentary rocks. Besides, the late Permian Emeishan basalts are difficult to contribute metals for regional Pb–Zn mineralization despite a closely spatial relationship with the distribution of the Pb–Zn deposit. This is supported by Pb isotopic ratios plotting above the average upper crustal Pb evolution curves and staying far away from that of the age-corrected Emeishan basalts. Hence, taking into account of the similarities in tectonic setting, ore-hosting rock, ore assemblage, wall rock alteration, ore-controlling structure, and ore-forming materials and the differences in relationship with regional magmatism, fluid inclusion characteristic and ore grade between the Maoping deposit and typical MVT Pb–Zn deposit, the ore genesis of the Maoping deposit should be an MVT like Pb–Zn deposit. [ABSTRACT FROM AUTHOR]