赣中紫云山地区钨矿床地质特征及找矿前景OA

The Ziyunshan area in central Jiangxi Province is located in the middle-eastern section of the Qinzhou-Hangzhou metallogenic belt.It is an important tungsten polymetallic ore concentration area in South China.Based on field surveys and comprehensive analysis of three typical W-deposits(Xushan,Juyuan and Xiaozhai),this paper establishes the spatio-temporal framework and metallogenic model,evaluates exploration potential,and offers theoretical guidance for regional prospecting.The results indicate that the tungsten deposits in this area are closely associated with the Early Yanshanian Ziyunshan pluton and of medium-to high-temperature hydrothermal origin.The mineralization types include quartz vein type,greisenized granite type and skarn type.Vertically,they exhibit a"five floors+basement"zoning pattern.The deep part is dominated by greisen-type orebodies;the middle part is dominated by skarn-type orebodies;and the shallow part is dominated by quartz vein-type orebodies.This constitutes a typical"trinity"deposit assemblage.Geochronological data indicate that the Ziyunshan pluton formed at 162～149 Ma,and the tungsten mineralization ages are concentrated at 155.8～147.1 Ma.For the Xushan deposit,the wolframite age is 149.8±4.1 Ma,and the muscovite age is 147.1±3.4 Ma.For the Juyuan deposit,the wolframite age is 155.8±4.6 Ma,and the granite porphyry age is 152.4±1.0 Ma.These close temporal correspondences suggest a strong coupling between diagenesis and mineralization,reflecting their common origin within a single magmatic-hydrothermal system.S-Pb-Sr-Nd-Hf isotopic tracing indicates that the ore-forming materials were derived from partial melting of Paleoproterozoic crustal materials.The ore-forming fluids were mainly magmatic water(δD=-68.3‰～-58.6‰,δ¹⁸OH₂O=5.1‰～7.5‰),with mixing of meteoric water.The homogenization temperatures range from 165 to 575 ℃,and the salinities range from 0.66 to 19 wt%NaCleqv.The fluids belong to a medium-high temperature,medium-low salinity NaCl-H₂O system.Temperature decrease was the key factor controlling tungsten precipitation and enrichment.Prospecting potential analysis suggests that the deep concealed plutons beneath the Xushan and Juyuan deposits have not been fully exposed.The deep part of the Xiaozhai deposit is expected to contain veinlet-large vein mixed zones and greisen-type orebodies.Priority exploration targets should therefore include the deep and peripheral sectors of known deposits,the outcrop areas of Nanhuaian low-grade metamorphic rocks,and the contact zones between granitic plutons and their wall rocks.Collectively,these findings enhance our understanding of tungsten metallogeny in central Jiangxi Province and provide a scientific basis for future exploration planning and resource assessment in the region.