The Panxi region, situated at the western margin of the Yangtze Platform, represents a significant Fe-Cu-Ni-(PGE)-Sn-Pb-Zn polymetallic metallogenic belt. This study investigates the representative Lugu Fe-Sn deposit in Mianning County, Sichuan Province, where orebodies occur as stratoid and lenticular lenses within the contact zone between the Neoproterozoic Lugu composite granite and Mesoproterozoic dolomitic marble (Darezha Formation). The major ore types are magnetite and cassiterite-dominant ores, with average grades of w(TFe) = 37.81 %-53.52 % and w(Sn) = 0.63 %. Mineralization is divided into three hydrothermal stages: magnetite (I, hematite is scattered irregularly in magnetite in the form of fine droplets), magnetite-cassiterite-apatite (II, the main Sn-enrichment stage, characterized by extensive development of magnetite and cassiterite, associated with serpentine and brucite), and quartz-sulfide (III, with pyrite, chalcopyrite, and sphalerite). An integrated approach including field geology, petrography, LA-ICP-MS (zircon/cassiterite U-Pb dating; magnetite/sphalerite trace element), and in-situ sulfur isotope analysis was employed. The main findings are as follows: (1) New zircon U-Pb ages (813.9 +/- 3.6 Ma, 801.8 +/- 2.9 Ma) and a cassiterite U-Pb age (827 +/- 13 Ma) constrain the magmatism and mineralization to the Neoproterozoic intra-Rodinia extension stage. The 15 Ma-25 Ma interval between earliest zircon crystallization and cassiterite precipitation reflects protracted magmatic-hydrothermal evolution of a composite pluton. (2) The highly differentiated signature of the Lugu granite (w(Nb)/w(Ta) < 5) and sulfur isotope composition of sulfides (delta S-34 = 8.38 parts per thousand-11.22 parts per thousand) indicate that Fe, Sn, and S were primarily derived from the granitic magmatic-hydrothermal system. Zircon Hf isotopes (epsilon(Hf)(t) = -4.34--0.57; T-DM2 = 1.96 Ga-1.74 Ga) further demonstrate derivation from an enriched, Paleoproterozoic crustal source. (3) Magnetite trace elements indicate that Stages I-II formed under high temperatures (300 degrees C-679 degrees C) and high oxygen fugacity (FMQ + 1 to FMQ + 3). For Stage III, sphalerite geochemistry constrains the temperature to 238 degrees C-241 degrees C, accompanied by high sulfur fugacity (logf(S2) = -8.5--8.0) and reduced conditions. (4) Magnetite (low Ti, V, Cr, high Mg, and Ni/Cr >> 1) and sphalerite (Ga/In < 1, Fe-Mn enrichment) trace-element discriminants, combined with the Mg-silicate-dominated alteration assemblage (serpentine, brucite, talc) confirm the Lugu Fe-Sn deposit as a magnetite-dominant, magnesian skarn (skarn-like) deposit. This study elucidates the genesis of Fe-Sn mineralization in the belt and provides a scientific basis for regional exploration.

The Micangshan lead-zinc deposits, located in the northern margin of the Sichuan Basin, are classified as the Mississippi Valley-type (MVT) deposits. This study investigates the genetic linkage between Pb-Zn mineralization and paleo-oil reservoirs in the region, which is distinct from separate investigations on lead-zinc deposits or paleo-oil reservoirs. Through mineralogy, isotope, and fluid inclusion analyses, it is revealed that the direction of ore-forming fluid migration and the ore-forming process are closely related to the thermal cracking of paleo-oil reservoirs. The deposits show a characteristic clustered distribution along the southern part of the Micangshan area, with high-grade mineralization concentrated in the Nanmushu and Kongxigou Pb-Zn deposits. Rb-Sr isotopic dating indicates that mineralization occurred during the Late Cambrian to Early Ordovician (Nanmushu deposit 486.7 +/- 3.1 Ma; Kongxigou deposit 472 +/- 6.1 Ma), coinciding with the formation of the first-stage paleo-oil reservoirs. The study concludes that the MVT Pb-Zn mineralization in the Micangshan area is genetically linked to the first-stage paleo-oil reservoirs' hydrocarbon generation and migration events. The organic-rich hydrothermal fluids facilitated the migration and precipitation of Pb-Zn minerals.

The Sichuan-Yunnan-Guizhou (SYG) metallogenic belt hosts numerous carbonate-hosted Pb-Zn deposits, yet the genesis of lead-dominated deposits remains poorly understood. This study investigates the Wuyi Pb deposit, a representative lead-dominated deposit in the SYG belt, through an integrated approach including field geology, fluid inclusion microthermometry, and C-H-O-S-Pb isotope geochemistry. The ore bodies occur as stratoid and lenticular lenses within the dolomitic limestone of the Ordovician Dajing Formation, controlled by both lithology and the Wuyi composite fold structure. Mineralization is divided into two stages: (I) pyrite-sphalerite-dolomite-calcite, and (II) galena-calcite-quartz-anhydrite. Fluid inclusion studies reveal that the ore-forming fluids are of the NaCl-H2O system, characterized by moderate-low temperatures (Stage II, average 201 degrees C) and moderate-low salinities (Stage II, average 5.35 wt% NaCl eq.). Hydrogen and oxygen isotopes (delta D = -100.97 to -76.33 parts per thousand; delta 18Ofluid = 7.09 to 12.10 parts per thousand) indicate that the ore-forming fluids were predominantly meteoric in origin. Carbon isotopes (delta 13C = -4.45 to 0.75 parts per thousand) suggest that carbon was derived mainly from dissolution of the host carbonate rocks. Sulfur isotopes show a significant shift from Stage I (delta 34S = -12.40 to -3.00 parts per thousand) to Stage II (delta 34S = -8.20 to -0.10 parts per thousand for sulfides; 25.00-29.40 parts per thousand for sulfates), indicating a transition from bacterial sulfate reduction (BSR) to thermochemical sulfate reduction (TSR) as the dominant sulfur reduction mechanism, with sulfur derived from Ordovician seawater sulfate. Lead isotopes (206Pb/204Pb = 18.10-25.37, 207Pb/204Pb = 15.50-21.72, 208Pb/204Pb = 38.29-53.90; mu = 9.30-21.05) demonstrate that metals were sourced predominantly from the Proterozoic basement rocks (Kunyang and Huili groups). Integration of geological, geochemical, and isotopic evidence indicates that the Wuyi Pb deposit formed during the Indosinian post-collisional intracontinental orogeny (ca. 230-200 Ma), when topography-driven meteoric water circulation extracted metals from the Precambrian basement and sulfur from Ordovician strata. Metal precipitation under the reduced sulfur model is caused by decreases in temperature and pressure and the water-rock reaction. This study establishes the Wuyi deposit as an MVT Pb deposit and provides a genetic model for lead-dominated mineralization in the SYG belt.

The Nanmushu Pb-Zn deposit in the Mayuan district of Shaanxi Province, located on the northern margin of the Yangtze Block, is a representative Ge-rich deposit in the Mayuan ore concentration area and is therefore of significant scientific importance. Currently, the influence of physical and chemical parameters such as temperature, fO2, fS2 and pH of ore-forming fluids on Ge precipitation and mineralization efficiency in Ge-rich Pb-Zn deposits is not yet clear. Accordingly, in this research, (LA)-(MC)-ICP-MS combined with thermodynamic phase diagram analysis was employed to investigate the key factors controlling Ge enrichment in sphalerite and the modes of Ge substitution into sphalerite. These results suggest that sphalerite in the Nanmushu deposit commonly exhibits zoned texture, with high enrichment of Ge observed in the second and fourth zones, with average contents of 612 ppm and 545 ppm, respectively. Ge substitutes for Zn via coupled substitution with monovalent cations, expressed as: 2(Ag+ + Cu+) + Ge4+ ↔ 3 Zn2+. Sulfur and carbon isotope composition and thermodynamic phase diagram analysis reveal that pH and fO2 exerts only a minor influence on Ge enrichment in sphalerite, whereas temperature and fS2 jointly control the enrichment process. The minimum fS2 value required for Ge enrichment systematically increases with rising temperature, while relatively high fS2 conditions are conducive to Ge enrichment.

The Danba-Dadu River gold belt on the western Yangtze Craton margin is a major gold province in China. The Dulanggou gold deposit is a large quartz-vein-type deposit recently discovered in this belt. Ore bodies are fault-controlled veins hosted in high-grade metamorphic rocks of the Devonian Weiguan Formation. Mineralization includes three stages: early (quartz-minor sulfide), main (quartz-abundant sulfide-native gold-Te-Bi minerals), and late (quartz-minor sulfide-calcite). Fluid inclusion studies show the following. Early-stage inclusions are mainly CO2-H2O-type (homogenization temperature 307-388 degrees C, salinity 0.4-7.1 wt.% NaCl eqv.) with minor NaCl-H2O-type. Main-stage inclusions are dominated by CO2-H2O and NaCl-H2O types, with minor pure CO2 inclusions (homogenization temperature 207-307 degrees C, salinity 0.2-11.2 wt.% NaCl eqv.). Late-stage inclusions are mainly NaCl-H2O-type (168-223 degrees C, 4.6-10.1 wt.% NaCl eqv.). Laser Raman analysis detects CH4 in the fluid. The ore-forming fluid is a reducing, medium-low temperature, low-salinity H2O-CO2-NaCl-CH4 system. Thermodynamic calculations of CO2-H2O inclusions yield total densities of 0.94-1.03 g/cm3 and total homogenization pressures of 170-276 MPa for the early stage, and slightly lower densities (0.94-1.01 g/cm3) with pressures of 170-246 MPa for the main stage, indicating a progressive pressure decrease during fluid evolution. Hydrogen and oxygen isotopes (early stage: delta D -96.4 parts per thousand to -78.9 parts per thousand, delta 18OH2O 6.1 parts per thousand to 6.5 parts per thousand; main stage: delta D -104.3 parts per thousand to -75.1 parts per thousand, delta 18OH2O 5.3 parts per thousand to 7.1 parts per thousand) indicate that the ore-forming fluid was mainly derived from primary magmatic water. Immiscible CO2-H2O and NaCl-H2O inclusion assemblages in the main stage suggest that fluid immiscibility was the key mechanism for gold precipitation. The Dulanggou deposit resembles classic orogenic gold deposits in host rocks, ore-controlling structures, mineral assemblages, and low-salinity CO2-rich fluids. However, its H-O isotopes and thermodynamic data point to a magmatic water source, distinct from the metamorphic water source of typical orogenic gold deposits. This highlights the diversity of fluid sources in orogenic gold systems along the western Yangtze Craton margin.

[Objective] Orogenic gold deposit is widely developed in the Daduhe gold metallogenic belt. The Yizhuxiang gold deposit is one of the representative medium-sized deposits in the Daduhe gold metallogenic belt. Pyrite is the main gold-bearing mineral in the deposit, and its formation period is obvious, providing an ideal example for understanding the mineralization of this orogenic gold deposit. [Method] Based on detailed field work, this article conducted a comprehensive study on the ore samples of the Yizhuxiang gold deposit, including mineralogical observation, electron probe analysis, pyrite thermoelectric property testing, and pyrite trace element analysis, to explore the occurrence state of gold minerals in the ore and the typomorphic characteristics of pyrite. [Result] The gold minerals in the deposit are mainly natural gold, presenting as microscopic gold, with generally high fineness. They mainly exist in the form of inclusion gold and fissure gold in pyrite and its fissures, and some are found in chalcopyrite and bismuth tellurite as inclusion gold. [Conclusion] The main gold-bearing minerals in the deposit are pyrite and chalcopyrite. Gold mainly exists in pyrite in the form of inclusion gold and fissure gold. Pyrite basically does not contain lattice gold and nano-gold. The bismuth telluride (Te-Bi-S) melt represented by bismuth telluride may have an enriching effect on gold. The calculation results of the thermoelectric coefficient of pyrite in the deposit show that the crystallization temperature of pyrite is approximately 278 ℃, and it is speculated that the deposit belongs to a high - to medium-temperature hydrothermal deposit. Through the analysis of thermoelectric properties, it is possible that the ore body has been eroded to a certain extent.

The Wusihe lead-zinc deposit,situated at the southwestern margin of the Yangtze Block and a prominent Ge-enriched deposit within the Sichuan—Yunnan—Guizhou lead-zinc metallogenic belt,faces ongoing debates regarding its genesis.The influence of sphalerite typomorphic characteristics on Ge enrichment and substitution mechanisms within the deposit remains a crucial puzzle to unravel.To address this,the paper employs quantitative analyses using microscopic spectrophotometry and laser ablation-inductively coupled plasma-mass spectrometry(LA-ICP-MS).The results reveal the presence of two sphalerite stages during the hydrothermal period:a darker Stage Ⅰand a lighter Stage Ⅱ.Despite similar mean values for visual reflectance and the dominant wavelength of reflectance color,the mean reflectance color saturation differs(0.048 and 0.043,respectively),with corresponding average Ge contents of 244.33×10-6µg/g and 43.22×10-6µg/g,respectively.The experimental outcomes conclude that Ge exists in sphalerite as isomorphism and is more concentrated in sphalerite with higher reflectance color saturation.The ore-forming temperature is medium to low,classifying the deposit as a Mississippi Valley-type lead-zinc deposit.The BRIEF REPORT is available for this paper at .

Lithium-rich claystones found in the Carboniferous bauxite of the southwestern Yangtze Block represent a significant type of lithium resource. However, the origin of these claystones and the mechanisms underlying lithium enrichment remain poorly understood. This study investigates Li-rich claystone samples from three locations in central Guizhou using petrography, X-ray diffraction (XRD), scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS), Tescan Integrated Mineral Analyzer (TIMA), and laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) to elucidate the occurrence and enrichment mechanisms of lithium. Mineralogical and geochemical analyses indicate that lithium is primarily hosted in clay minerals, with cookeite (4667-5578 ppm), kaolinite (68-10703 ppm), and illite (1384-2351 ppm) serving as the key carriers. Accessory minerals (e.g., diaspore, pyrite) contain negligible amounts of lithium (<25 ppm). Lithium enrichment occurs through multi-stage dissolution-recrystallization during diagenesis. Paleoenvironmental factors influence the distribution of lithium: terrestrial environments preserve detrital kaolinite with the lowest lithium concentration; transitional zones feature cookeite-dominated assemblages with peak enrichment; and marine settings host illite-rich facies with moderate lithium concentrations. Lithium incorporation occurs via entry into octahedral sites and interlayers during clay mineral reorganization, with terrigenous Li-rich muscovite identified as a critical precursor. Environmental evolution and fluid-mediated clay transformations control lithium enrichment, reflecting the four-stage genesis of lithium-rich claystone. These findings provide valuable insights for targeting exploration of this promising lithium resource.

The Gudui-Riruo geothermal system, located in the southern Tibet, exhibits higher temperatures compared with other geothermal systems at similar depths in China. However, the origin and circulation mechanisms of the geothermal water in the Gudui-Riruo geothermal field remain unclear. Therefore, this study offers a detailed comparative analysis of hydrochemical and hydrogen-oxygen isotopic characteristics of geothermal waters from five geothermal manifestation zones within the Gudui-Riruo geothermal system, aiming to improve the understanding of their genesis and circulation mechanisms. Hydrochemical characteristics indicate that the geothermal waters are notable variations in different manifestation zones in the study area. Na-Cl-type geothermal waters are present in the Buxionglanggu (BXLG), Shagalangga (SGLG), and Babudemi (BBDM) zones, whereas Na·Ca-Cl·HCO3 type waters are distributed in the Chaka (CK) and Riruo (RR) zones. The geothermal waters originate from a common deep parent geothermal fluid with the Cl concentration and enthalpy of 645 mg/L and 1757 J/g °C, respectively. Hydrogen and oxygen isotopic characteristics reveal that the primary source of the Gudui-Riruo geothermal waters is high-altitude atmospheric precipitation, with about 14% to 18% attributed to mixing with magmatic water. Based on the geological background of the southern Tibetan Plateau and the hydrochemical and isotopic characteristics of the geothermal waters in the study area, a genesis circulation model for the Gudui-Riruo geothermal system is established. Infiltrating meteoric water mixes with residual magmatic fluid to create the parent geothermal fluid, which then ascends along fractures and experiences various cooling processes, resulting in hot springs that exhibit varying hydrochemical characteristics. Based on hydrochemical analysis, five cooling processes have been identified for geothermal waters ascending from the reservoir to the surface: conductive cooling, adiabatic cooling, mixing with cold groundwater, and combinations of these processes.

1. Three-dimensional (3D) deterministic modeling is crucial for analyzing the controlling factors of mineralization. The Shanggong gold deposit, situated in the southern margin of North China Craton, represents a magmatic hydrothermal deposit. To construct the 3D deterministic model, boreholes, cross-sections, and geochemistry assays are integrated based on the geological characteristics of the Shanggong gold deposit. This paper summarizes its contents as follows: 1) GoCAD software can be utilized to build a 3D geology model encompassing faults and ore bodies; 2) Geostatistics and discrete smooth interpolation (DSI) can be employed to create a 3D attribute model involving grade and Au/Pb ratio. The findings reveal that: 1) High-value zones are associated with NE and NNE trending cross faults; 2) Deterministic modeling, such as grade model and Au/Pb ratio model, effectively elucidates the metallogenic process mechanism.

There is a widely recognized association of bismuth (Bi)-tellurium (Te) minerals with gold in many hydrothermal gold deposits. However, the specific process for gold enrichment related to Bi-Te minerals remains enigmatic. The Dulanggou gold deposit, located on the southeastern margin of the Songpan-Garz & ecirc; orogenic belt, China, provides an opportunity to research this process. Gold in the deposit is mainly associated with coarse-grained Bi-Te minerals and bismuth-rich polyphase metal droplets. Three mineralization stages are identified in the deposit. In Stage 1, a small amount of gold was deposited within dominate pyrrhotite. In Stage 2, a large amount of visible gold grains were precipitated with coarse-grained Bi-Te minerals. The various Bi-Te phases are mainly tsumoite, pilsenite, unnamed minerals (Bi3Te2, Bi2Te), jos & eacute;ite-B and trace hedleyite, which have a common characteristics of 2 >= Bi/Te > 1. In stage 3, around the Stage 2 large Bi-Te phase patches, bismuth-rich polyphase metal droplets pervasively occurred with Bi/Te >= 2. Other Bi-Te minerals in Stage 3 include hedleyite, unnamed minerals (Bi3Te, Bi8Te3, Bi5Te), jos & eacute;ite-B, and jos & eacute;ite-A, all intergrowth with gold and maldonite in the metal droplets. Mineral chemistry and phase diagrams of the Bi-Te mineral assemblages indicate that the mineralization temperatures at Stages 2 and 3 are > 325 degree celsius and around 235 degree celsius respectively, and the fTe(2) and fS(2) gradually decrease from Stage 2 to Stage 3. Importantly, a large amount of native gold was deposited with native Bi during Stage 3 and Bi contents in Bi-Te minerals increase with gold fineness from 799 similar to 876 at Stage 2 to 833 similar to 939 at Stage 3. These indicate that the metal droplets could be Bi-rich melts which were separated from Bi-Te phase patches and scavenged gold from earlier mineral assemblages to enhance gold enrichment.

The Lijiagou pegmatite spodumene deposit, located in the middle of the Songpan–Garze Fold Belt and southeast of the Ke’eryin ore field, is a newly discovered super-large deposit. In order to reveal the metallogenic tectonic environment and evolution process of pegmatite, based on the study of the geological characteristics of pegmatite, we carried out a whole-rock geochemical analysis of Ke’eryin two-mica granite and Lijiagou pegmatite and carried out a detailed electron probe microanalysis (EPMA) and laser ablation inductively coupled plasma mass spectrometry (LA-ICPMS) analysis of mica minerals in each zonal pegmatite. The results show that the Ke’eryin two-mica granite is mainly formed in the transition period from syn-collision to post-collision. After the end of the continental collision, the crust is squeezed and thickened in the post-collision extensional transition tectonic environment. Mica from the microcline pegmatite zone (MP) to the albite spodumene pegmatite zone (ASP) in pegmatite show different compositions and structural characteristics, with the evolution trend in the direction from muscovite to Li-bearing mica. The type of mica from MP to AP is mainly muscovite, and Li-bearing mica appears in ASP, which is secondary and metasomatic at the edge of primary muscovite. From MP to ASP, there was a negative correlation between Nb/Ta, K/Rb and the Li, Rb, and Cs contents of mica, while the contents of Li, Rb, Cs, and F in the Li-bearing mica of ASP increased sharply. This evidence illustrates that the favorable tectonic environment contributed to the formation of the Lijiagou pegmatitic spodumene deposit. Lijiagou pegmatite experienced the magmatic–hydrothermal evolution process and has a high degree of differentiation and evolution from MP to ASP, which gradually increased. Combined with the change in mica type, it is considered that ASP formed from the stage of magmatic transition to hydrothermal and was a hydrothermal environment, and Li, Rb, and Cs mainly began to enrich at the stage of magmatic–hydrothermal transition.

The relationship between the color of sphalerite and trace elements has aroused the interest of researchers since a long time, but most of the study is still in the qualitative stage. In this contribution, we made attempt to reveal the relationship between the reflection color and its trace element, in order to discuss the genetic significance of various reflection colors of sphalerite through the quantitative study of reflection color of sphalerite. Based on LA-ICP-MS analysis and microspectrophotometer analysis of sphalerite samples in different types of deposits, the elements with significant correlation with the reflection color index were found and analyzed by factor analysis. Different genetic types of sphalerites have different color index, The average reflection color indices of each type sample are as follows, sphalerite from Mengya'a deposit: & lambda;d = 477.3 nm, Pe = 0.046, Rvis = 17.23%; sphalerite from Zhaxikang deposit: & lambda;d = 477.2 nm, Pe = 0.043, Rvis = 16.70%; sphalerite from Nanmushu deposit: & lambda;d = 476.4 nm, Pe = 0.038, Rvis = 16.55%. The reflection color index of sphalerite is correlated with the content of Mn, Fe, Ga, Ge, Ag, Cd, In, Tl, Pb. The results of factor analysis indicate that sphalerite with high reflectivity is more abundant in Fe, Mn and In, while the sphalerite with low reflectivity is more abundant in Ge, Tl, Pb and Ag. Furthermore, the reflection color index of sphalerite can be used to distinguish the genetic type of deposits. Based on an obvious linear relationship between the reflection color index of sphalerite and its mineralization temperature, we propose a new empirical equation: T(degrees C) = 61.4*Rvis + 1.1*& lambda;d + 6000*Pe-1533 which can be used as a geological thermometer.

AbstractThe carbonate-hosted Pb–Zn deposits in the Sichuan–Yunnan–Guizhou (SYG) triangle region are important Indosinian deposits in South China. The Tianbaoshan deposit is a typical large Pb–Zn deposit in the SYG area and occurs as pipe-like type, hosted by Sinian dolostone. It contains ∼26 Mt Zn–Pb ore (7.76–10.09 % Zn, 1.28–1.50 % Pb and 93.6 g t−1 Ag) and >0.1 Mt Cu ore (2.55 % Cu). In this study, the detailed mineral textures, mineral chemical and sulphur isotopic compositions of the various sulphides have been analysed to constrain the abnormal enrichment mechanism and mineralization relationship. Four mineralization stages have been recognized: Stage 1, minor early pyrite (Py1) with relics and infill of intergranular dolomite or quartz grains; Stage 2, Cu mineralization with coarse-grained, elliptical crystal chalcopyrite (Cp1); (3) Stage 3, Zn mineralization with dark fine-grained sphalerite (Sph1) and light coarse-grained sphalerite (Sph2); and (4) Stage 4, as represented by a quartz–calcite assemblage with galena, minor pyrite (Py2) and chalcopyrite (Cp2). The petrography of the sulphide minerals (Py1, Cp1, Sph1 and Sph2) demonstrates a mutual inclusion relationship. The nature of this relationship from core to rim and their similar sulphur isotope values (5.5–8.3 ‰) indicates a single sulphur source, suggesting that the different mineralization types are the result of different stages of a continuous hydrothermal system. Sphalerite geothermometer study suggests that sphalerite in the Tianbaoshan deposit formed in a low-temperature (<200 °C) hydrothermal system. The low concentrations of Mn and In, low In/Ge ratios and high Fe/Cd ratios in the sphalerite are consistent with those of Mississippi Valley-type (MVT) deposits, but different from those of magmatism-related deposits (e.g. epithermal, skarn and VMS deposits). The positive δ34S values for Py1 (5.1–7.9 ‰), Cp1 (5.1–7.2 ‰), Sph1 (4.7–7.4 ‰), Sph2 (3.9–8.7 ‰), Py2 (4.4–9.3 ‰) and Cp2 (5.0–6.8 ‰) indicate a sulphur source from thermochemical reduction of coeval seawater sulphate. Widely developed dissolved textures (caverns and breccias) with massive sulphide infillings and deformed host rock remnants suggest that replacement of host dolostones by ore fluids was volumetrically significant and the ore formed nearly simultaneously with the cavities. The Tianbaoshan deposit is a typical MVT deposit, which resulted from mixing of a H2S-rich fluid and a metal-rich fluid, with thermochemical sulphate reduction occurring before ore precipitation rather than during ore precipitation.

Ljiagou pegmatite spodumene deposit is part of the Ke’eryin ore-field in the central Songpan-Garze Fold Belt of Sichuan, China. After recent exploration and assessment, it has been established as a new super-large spodumene deposit. In order to determine the processing characteristics of the ore and assess its industrial value, based on detailed microscopic and hand specimen observations, this study employs various methods and techniques, including X-ray powder diffraction (XRD), electron probe microanalysis (EPMA), laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS), chemical element analysis, chemical phase analysis and the mineral liberation analyzer system (MLA). The average grade of lithium ore is 0.86%, making it a low-grade ore with 84.1% of Li derived from spodumene. The Li grade decreases with increasing depth, and the samples from shallower depths are easier to dissociate. The spodumene exhibits a wide range of grain sizes and is highly heterogeneous, requiring multiple stages of grinding. Based on the liberation characteristics, it is recommended to grind the material to −0.075 mm before entering the final flotation process.

含高放射性成因铅是商代青铜器的重要特征,但对其矿料来源的讨论众说纷纭,莫衷一是.笔者等收集了河南郑州商城、山西垣曲商城、湖北盘龙城、四川三星堆、陕西汉中(地区)、江西新干大洋洲、河南安阳殷墟和陕北(地区)覆盖整个商代的8个遗址/地区700件出土青铜器样品的铅同位素组成数据,并与全国606个Pb—Zn、Cu、Sn多金属矿床4025件矿石样品的铅同位素组成数据进行比对分析,探讨商代青铜器的矿料来源和古蜀国在矿业贸易中的地位.研究表明:①河南郑州商城、湖北盘龙城、陕西汉中、山西垣曲商城、河南安阳殷墟和陕北6个遗址/地区的青铜器很可能采用了含异常铅和正常铅的两类铅料;而四川三星堆与江西新干大洋洲出土的青铜器则主要采用了含异常铅的铅料.四川三星堆、陕西汉中和陕北3个遗址/地区出土的青铜器很可能采用了含异常铅和正常铅的两类铜料;而河南郑州商城、湖北盘龙城、山西垣曲商城、河南安阳殷墟与江西新干大洋洲出土的青铜器采用的铜料很可能以含正常铅为主,但不排除采用含异常铅铜料的可能性.②对比全国Cu、Pb—Zn、Sn及多金属矿床铅同位素资料,商代遗址出土的青铜器中的高放射性成因铅的铅料,最有可能来自四川云南交界处的MVT型Pb—Zn矿床;而含高放射性成因铅的铜料,则最可能来自四川云南交界处的IOCG型Cu矿和山西中条山铜矿峪Cu矿床.③综合三星堆遗址得天独厚的地理位置,三星堆青铜文明的兴衰时间及其与其他文化交流与贸易往来的路径,推测古蜀三星堆很可能是商代含高放射性成因铅的铅料及部分铜料贸易的大型中转地,商代含高放射性成因铅的青铜器的兴盛与衰落则很可能与三星堆青铜文明的开启与消亡有关.

独狼沟金矿是位于丹巴成矿带中穹窿边缘的典型的石英脉型金矿,矿床中发育大量明金与碲铋矿物.本文以独狼沟金矿中碲铋矿物及自然金为主要研究对象,通过显微岩相学观察、扫描电镜、能谱以及电子探针分析,对矿床中碲铋矿物和自然金的赋存状态进行了较为详细的研究,并对金的富集机制进行了探讨.结果表明,碲铋矿物与自然金主要在成矿Ⅱ、Ⅲ阶段产出,矿石中自然金主要为含银自然金,成色整体偏高,平均为881,碲铋矿物主要有楚碲铋矿、叶碲铋矿、赫碲铋矿、硫碲铋矿B、未命名碲铋矿物(Bi2Te、BBi8Te3、Bi3Te)以及自然铋,碲铋矿物与自然金具密切的时空关系.结合前人流体包裹体的研究结果,认为成矿Ⅱ阶段到Ⅲ阶段过渡的过程中温度以及体系中碲逸度的降低是矿床中多种碲铋矿物相形成的关键,独狼沟金矿成矿的物理化学条件以及碲铋矿物与自然金的矿物特征均指示成矿过程中金-铋-碲熔体对热液中金的抽取是导致自然金富集的关键.