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雪岭矿区位于扬子板块西缘,浅部赋存的铜多金属矿化受落因断裂系南延断裂及其次级断裂和辉绿岩脉所控制产出于灯影组白云岩中。对矿区浅部铜多金属矿化的岩矿石地球化学和同位素地球化学分析显示:围岩与矿石的稀土元素特征相似,且围岩富集Cu,Ag,Pb,Zn等成矿元素,故围岩应该为成矿提供了部分成矿物质;与之共生的石英样品δD_(V-SMOW)值介于-85.7‰~-102.2‰,δ~(18) O水值介于0.9‰~2.4‰,表明成矿流体以层间封存水为主,混合了部分天水和原生岩浆水;3件来自铁矿化带中的黄铁矿δ34 SV-CDT值为+9.9‰~+27.4‰,1件来自铜银(铅锌)矿化带中裂隙脉状矿体的黄铁矿δ34 SV-CDT值为-37.5‰,暗示本区硫来源复杂,硫可能主要来源于沉积地层的海相硫酸盐,部分混染幔源硫和生物硫,或者与其成矿过程中fO2和pH值发生急剧变化有关;3件来自铁矿化带的黄铁矿~(206)Pb/~(204)Pb=18.279~18.372,~(207)Pb/~(204)Pb=15.653~15.673,208Pb/~(204)Pb=38.272~38.462,1件来自铜银(铅锌)矿化带裂隙脉状矿体的黄铁矿~(206)Pb/~(204)Pb=19.310,~(207)Pb/~(204)Pb=15.771,208Pb/~(204)Pb=38.792,显示本区铅来源复杂,具壳幔混合铅的特征;具正确铅特征的硫铁矿模式年龄为260 Ma~350 Ma,与峨眉山玄武岩的成岩时代相近。经综合分析,本区浅部铜多金属矿化应是晚二叠世时,受峨眉山玄武岩喷溢作用热动力影响导致热液萃取深部陡山沱组成矿物质,并沿途淋滤围岩中部分成矿物质,沿断裂带向上运移至浅部灯影组白云岩中沉淀富集所致。
The Xueling mining area is located in the western margin of the Yangtze plate. The shallow polymembranes of copper polymetallic mineralization are controlled by the southern extension fault of the decadal fault system and its secondary faults and diabase dikes, resulting in the occurrence of the dolomite of the Dengji Formation. The geochemical and isotopic geochemical analyzes of rock ores in shallow copper-polymetallic mineralization show that the characteristics of rare-earth elements are similar to the surrounding rock and ore, and the surrounding rock is rich in ore-forming elements such as Cu, Ag, Pb and Zn The rocks should provide some ore-forming materials for ore-forming. The δ-V value of quartz samples symbiosed with them ranged from -85.7 ‰ to -102.2 ‰, and δ 18 O values ranged from 0.9 ‰ to 2.4 ‰ , Indicating that the ore-forming fluid is mainly interlayered sealed water and mixed with part of the Tianshui and primary magmatic water. The δ34 SV-CDT value of pyrite in the iron ore belt is + 9.9 ‰ ~ + 27.4 ‰ and 1 The δ34 SV-CDT value of pyrite from the fissured vein ore body in the copper-silver (Pb-Zn) mineralization belt is -37.5 ‰, suggesting that the source of sulfur in this area is complex and the sulfur may be mainly derived from the marine sulfate of the sedimentary strata. Part of the mantle-derived sulfur and bio-sulfur were partially mixed, or related to the drastic changes of fO2 and pH during the ore-forming process. Three pyrite from the iron mineralization belt had 206 Pb / 204 Pb = 18.279 ~ 18.372, ~ (207) Pb / ~ (204) Pb = 15.653 ~ 15.673, 208Pb / ~ (204) Pb = 38.272 ~ 38.462, and 1 yellow iron from the vein of copper- (206) Pb / ~ (204) Pb = 19.310, ~ (207) Pb / ~ (204) Pb = 15.771,2 08Pb / ~ (204) Pb = 38.792, indicating that the Pb source in this area is complex and characterized by crust-mantle mixed lead. The pyrites with the correct lead age range from 260 Ma to 350 Ma, similar to the Emeishan basalts. After comprehensive analysis, the shallow copper polymetallic mineralization in this area should be Late Permian. Due to the thermodynamic influence of Emeishan basalt spurting, the deep Doushantuo mineralization by hydrothermal extraction and the leaching of part of the surrounding rock The ore-forming materials migrate upward along the fault zone to the enrichment of sediments in the Dengying Formation dolomite.