Research Progress and Prospecting Directions of Sedimentary‐Hosted Lead‐Zinc Deposits in the Qinling Metallogenic Belt, China

ABSTRACT The Qinling orogenic belt, a central component of China's orogenic framework, hosts significant lead‐zinc (Pb‐Zn) deposits. This study presents a detailed analysis of their geological characteristics, spatio‐temporal distribution, geochemical signatures, and metallogenic processes. The principal mineralization events are associated with the Hercynian exhalative and Indosinian overprint stages. Four major Pb‐Zn mineral districts—Xicheng, Fengtai, Zhashan, and Zhenxun—are identified, with mineralization predominantly hosted in Middle Devonian carbonate and fine‐clastic sedimentary rocks. The ore bodies occur predominantly as stratiform or lens‐shaped masses, dominated by sphalerite, galena, pyrite, calcite, dolomite, and baryte in mineral composition. Sulphide minerals are notably enriched in critical metals such as cadmium (Cd), germanium (Ge), gallium (Ga), and thallium (Tl), underscoring substantial economic resource potential. Geochemical analysis reveals the involvement of sedimentary‐reworking processes, with sphalerite Zn/Cd ratios indicative of medium‐ to low‐temperature mineralization (100°C–250°C). This is consistent with fluid inclusion analyses, which reveal homogenization temperatures ranging from 100°C to 250°C and salinities of 3–15 wt% NaCl equiv. Sulphur isotope compositions (δ 34 S) span −9.81‰ to 29.3‰, with the majority falling within 6.24‰–16.91‰. These data indicate marine or stratiform sulphate as the primary sulphur source, with thermochemical sulphate reduction (TSR) identified as the dominant sulphur reduction mechanism. Lead isotopic signatures exhibit mixed crustal‐mantle sources. Carbon, hydrogen, and oxygen (CHO) isotope data demonstrate that ore‐forming fluids have a mixed origin, primarily derived from seawater and organic‐derived fluids, with later contributions from magmatic and metamorphic fluids. A dynamic metallogenic model termed “early sedimentary exhalation followed by late‐stage multistage tectonic‐fluid coupling” is proposed. The research systematically characterises the spatial distribution patterns and metallogenic features of Pb‐Zn ore belts, providing critical guidance for future exploration targeting and resource assessment in the Qinling orogenic belt.