Carbonate-hosted Pb–Zn deposits are of major economic importance. The Sichuan–Yunnan–Guizhou metallogenetic belt (SYGMB), located on the western margin of the Yangtze Block, comprises over 400 carbonated-hosted Pb–Zn deposits. However, ore-forming fluids recorded in these deposits have led to controversy regarding ore genesis. We investigated a fluid system for the Maoping deposit in the SYGMB, based on fluid inclusions, and H–O–He–Ar isotopic studies. The results showed that ore-forming fluids in the Maoping deposit are characterized by mixing of high-temperature and low-salinity metamorphic fluids and low-temperature and high-salinity basinal brines. The Precambrian basement is considered to produce metamorphic fluids, while the basinal brines are said to originate from the Youjiang Basin. The mineralization at the depositional site appears to reflect the coincidence of the metamorphic fluids, basinal brines, Carboniferous coal seams, and structural-stratigraphic traps. Regional-scale data show large-scale heterogeneity in fluid properties, including basinal brines, metamorphic fluids, and organic fluids. Furthermore, the data suggest a precipitation model for some high-grade Pb–Zn deposits in the SYGMB. These findings will contribute to an understanding of deposit types in the SYGMB.

The Maliping large-scale Pb-Zn deposit is located in the Sichuan-Yunnan-Guizhou Pb-Zn polymetallic metallogenic triangle area (SYGT), where the Pb-Zn ore body is hosted in the interlayer fracture zone at the interface between siliceous cataclastic dolomite and clastic rocks in the Lower Cambrian Yuhucun Formation and is tectonically driven. Unlike other Pb-Zn deposits hosted in the Sinian and Carboniferous carbonate rocks in the area, the metallogenic mechanism and deep and peripheral ore prospecting prediction research require further exploration. In this study, representative samples of a typical orebody profile were systematically collected, and microthermometry of fluid inclusions and H-O isotopes and metal sulfide trace element analyses were performed. The main findings were as follows: (1) The fluid inclusion study showed that the ore-forming fluids have vapor-rich phase reduction characteristics of medium-low temperature, salinity, and density. (2) H-O isotopic studies showed that the ore-forming fluids are derived from the mixing of deep-source fluids flowing through the deep fold basement (Kunyang Group) and organic containing basin brine. (3) Rare earth element (REE) characteristics indicate that the ore-forming materials were primarily derived from the folded basement (Kunyang Group). (4) The trace element study showed that sphalerite is relatively enriched in Cu, Cd, Ga, and Ge, while depleted in Fe, Mn, Sn, and Co, similar to the typical Huize-type (HZT) Pb-Zn deposit in the area. Therefore, it is suitable to explore the deposit using a large-scale “four step style” ore prospecting method for ore prospecting and prediction. Moreover, the results provide a reference for the study of Pb-Zn metallogenic systems and new ideas for the deep and peripheral prospecting of Pb-Zn deposits in this area.

The Dahai Pb-Zn mining area is located in the northwestern Pb-Zn district in northeastern Yunnan Province in the Sichuan-Yunnan-Guizhou Pb-Zn metallogenic triangle (SYGT), east of the Xiaojiang fault. Numerous Pb-Zn deposits (spots) occur in clastic rocks in this area. In this study, the Maliping, Laoyingqing, and Jinniuchang Pb-Zn deposits, representative clastic rocks in the Dahai mining area, were selected as research objects. The results of H-O-S-Sr-Pb isotope analyses show that the three deposits mainly formed through the mixing of a basinal brine with a hydrothermal fluid derived from deep within the underlying (deformed) basement, and brines leached organic matter from wall rocks. The δ³⁴S values range from −2.62–30.30‰. The S isotope results show two different sources of reduced S: one in the Laoyingqing deposit derived from the S reduction generated by the pyrolysis of sulfur-bearing organic matter in the carbonaceous slate of the Kunyang Group, and the second in the Maliping and Jinniuchang deposits derived from the S reduction generated by the thermochemical sulfur reduction (TSR) of seawater sulfate in the Lower Cambrian Yuhucun Formation and Sinian Dengying Formation. The Pb isotope results show that the Pb sources of the three deposits are derived from basement rocks (Kunyang Group) with a small portion derived from Devonian–Permian carbonate rocks and Dengying Formation dolomite, both of which have undergone homogenization during mineralization. The Sr content varied from 0.09629 to 0.2523 × 10⁻⁶, and the study shows that the main source of Sr is a mixture of ore-forming fluid flowing through basement rocks (Kunyang Group) and through sedimentary cover. However, most of the Sr in the Maliping deposit is derived from marine carbonate, and in the Laoyingqing deposit, it is provided by basement rocks (Kunyang Group). Based on a comparative study of the deposits, the Pb-Zn deposits in the clastic rocks of the Dahai mining area and the SYGT belong to the same metallogenic system and were formed under the same metallogenic geological background. Finally, a unified metallogenic model of the two types of fluid migration and mixed mineralization of the Pb-Zn deposit in clastic rocks of the Dahai mining area is proposed. The metallogenic model provides a basis for the study of the Pb-Zn metallogenic system and guidance for deep and peripheral prospecting in this area.

The Dahongshan large-scale iron (Fe)–copper (Cu) polymetallic deposit is in the Proterozoic metallogenic domain on the western margin of the Yangtze Block. It is a typical representative of Fe-Cu polymetallic composite mineralization in the Kangdian area. The deposit comprises a group of layered orebodies formed by volcanic exhalation sedimentation and metamorphism, and a group of vein-like orebodies formed by hydrothermal superposition. The large-scale mapping of altered lithofacies in the deposit has resolved issues of weak links and unclear mineralization and alteration zoning of hydrothermal superimposed deposits within the study area. The mineralization type, hydrothermal alteration type and intensity, mineral assemblage, and mineral structure of the vein-type Cu polymetallic deposits during the hydrothermal superposition period are meticulously analyzed and studied. Finally, the zoning relationships of vein orebodies (mineralization) are summarized. On the basis of the results of the study of the distribution pattern of this mineral body, a mineralization alteration zoning model of the hydrothermal superposition period is constructed. The results show that the alteration is primarily silicification, carbonation, and chloritization, and the mineralization is chalcopyrite, bornite, chalcocite, and pyrite. The Dibadu anticline and the cutting layer faults and fractures strictly control the hydrothermal alteration zoning. The mineralization alteration zoning from the core to the flank is divided into coarse vein zone (I) → stockwork zone (II) → veinlet zone (III). The corresponding mineral assemblages are quartz–calcite–chalcocite–bornite–(native copper) (I) → calcite–dolomite–quartz–bornite–chalcopyrite–chlorite (II) → dolomite–quartz–chalcopyrite–(pyrite) (III), where the stockwork zone has the most substantial mineralization. The mineral assemblages of each alteration zone, the characteristics of rare earth elements of typical samples, and the test results on the fluid inclusions confirm that pH and Eh primarily control the zoning mechanism. This study has significance for deepening the understanding of the composite metallogenic system, guiding deep and peripheral prospecting, and providing significant enlightenment for the study of this type of deposit.

The Qingshan lead–zinc deposit is one of the typical deposits in the Weining–Shuicheng metallogenic belt in the northwest Guizhou mining area. This deposit is strictly controlled by tectonics, making it highly distinctive. This study used the REE, Fe, and Mn typological characteristics of calcite in the NE mineralization fault zone of the Qingshan lead–zinc deposit in Guizhou to trace the source of ore-forming materials and the local structural stress field characteristics of the fault. Through comprehensively applying structural analysis and LA-ICP-MS technology, the mechanical properties of the fault were analyzed and the REE characteristics of calcite, as well as the variation laws of Fe and Mn, were studied. The results of this study reveal that NE-trending mineralization faults controlled the production of gently inclined ore bodies; the distribution patterns of REEs in the three types of calcite are all “negative Eu-weak negative Ce-right skewed”, with the REE content in calcite near the ore body being significantly increased; furthermore, the variation pattern of Fe and Mn elemental contents in calcite indicate the local stress field characteristics of the ore-forming fault zone. The local opening space of NE-trending compressional and torsional ore-forming faults (where the dip angle slows down) is favorable for the nucleation of mineralized veins. With this study, we therefore improve knowledge regarding the relationships between tectonic stress fields and mineral exploration, serving as a potential source for the prediction of sites that are suitable for the exploitation of tectonic stress fields for mineral exploration, and show that mineral prediction is conducive to achieving the sustainable development of mines.

Interlayer-sliding faults play a crucial role in governing the distribution of metal deposits. Nevertheless, the mechanism by which these faults control the spatial arrangement of ore bodies throughout the evolution of fault–fold structures remains unclear. Here, we formulated three series of experimental models to explore variations in deformation and alterations in the mechanical characteristics of interlayer-sliding faults throughout the evolution of the thrust–fold structures. The experimental results indicate that the thrust faults formed in the three series of experiments all propagate in a piggyback propagation, displaying an imbricate thrust in cross-sections. Compared with Model 1 and Model 2, Model 3 demonstrates the longest transmission distance of the deformation front, the smallest thrust wedge taper angle, the fewest thrust faults with the largest spacing, and a reduction in the dip angle of the thrust fault. Particle image velocimetry (PIV) showed that in the top view, the position of minimum horizontal strain in each stage is the position of thrust faults. In the cross-sectional view, the development location of thrust faults shows the low-value area of the velocity field and surface strain field, and the development location of the interlayer-sliding fault and tensile space in the core of the fold displays the high-value area of velocity field and surface strain field. The structural characteristics of experiment 3 are highly similar to the actual geological model, indicating that there is a certain ore-hosting space in the Dengying Formation deep in the deposit. Although the expansion zone in the deep area is smaller than that in the shallow area, it still has favorable prospecting prospects.