【摘要】 江南造山带是世界级钨矿带，大规模钨成矿作用主要集中于晚中生代。尽管晚中生代的大型-超大型斑岩-矽卡岩型钨矿在江南造山带东段和中段广泛分布，但在江南造山带西缘鲜有报道。分布在江南造山带西缘桂北地区的平垌岭钨矿是受元宝山-龙岸断裂控制的中型热液脉型钨矿床（～1.4万吨WO₃），关于该矿床的成矿时代与成矿机制尚不明确。基于矿石的矿物共生组合和脉体穿切关系，平垌岭钨矿热液成矿过程可以分为石英-黑色黑钨矿（Ⅰ）和石英-棕红色黑钨矿-萤石-重晶石-硫化物（Ⅱ）两阶段。成分上两种颜色黑钨矿均属于钨锰矿（Mn/[Mn+Fe]>0.76），呈现左倾型稀土配分曲线，但棕红色晶体则具有更高的Mn含量和更亏损的重稀土，反映了两阶段钨成矿过程。黑色黑钨矿LA-SF-ICP-MS原位U-Pb定年结果表明桂北平垌岭钨矿的成矿年龄为74.9±6.8Ma，是华南目前已知最年轻的钨矿床之一。萤石和闪锌矿流体包裹体显微测温结果显示平垌岭钨矿第Ⅱ阶段成矿流体具有中低温（173～208℃）、中低盐度（0.37%～5.56%NaCleqv）的特征。闪锌矿的δ值集中在零附近（-2.53‰～1.01‰），暗示硫的来源为岩浆硫。结合石英发育皮壳状和梳状构造、黑钨矿呈现针状和片状晶形以及富Mn-Mo-Ta的成分特征，我们认为平垌岭钨矿是花岗岩相关的中低温热液脉型钨矿床，其深部具有良好的钨钼及稀有金属找矿潜力。本次研究证实江南造山带也存在晚白垩世钨成矿事件，在未来的找矿勘察过程中应该予以重视。更多还原

【Abstract】 The world-class Jiangnan tungsten metallogenic belt in South China,hosts large-scale tungsten mineralization primarily concentrated in Late Mesozoic.Although giant porphyry-skarn tungsten deposits in Late Mesozoic are widely distributed in the eastern and central segments of the Jiangnan Orogen,the Late Mesozoic tungsten mineralization has rarely been reported in the western Jiangnan Orogen.The Pingdongling tungsten deposit located in the western Jiangnan Orogen,in Guangxi,is a medium-sized hydrothermal vein-type tungsten deposit（～14,000 tons of WO₃）,and the timing and origin of tungsten mineralization are still unclear.Based on ore texture,mineral assemblage and crosscutting relationships,the hydrothermal mineralization process of Pingdongling tungsten deposit can be divided into two stages:quartz-black wolframite（stage Ⅰ） and quartz-brownish-red wolframitefluorite-barite-sulfides（stage Ⅱ）.Both types of wolframite belong to huebnerite（Mn/[Mn+Fe]> 0.76）,displaying a left-leaning REE pattern,but the brownish-red crystals have a higher Mn content and more depleted HREE pattern,indicating a two-stage tungsten mineralization process.In-situ LA-SF-ICP-MS U-Pb dating of the black wolframite yielded a mineralization age of 74.9±6.8Ma for the Pingdongling tungsten deposit,making it one of the youngest tungsten deposits known in South China.The fluid-inclusion microthermometry of fluorite and sphalerite indicate that the stage-Ⅱ mineralization fluid is characterized by medium-low temperatures（173～208℃） and medium-low salinities（0.37%～5.56% NaCleqv）.The δ³⁴ S_V-CDT values of sphalerite are concentrated near zero（-2.53‰～1.01‰）,implying the sulfur of a magmatic origin.Combined with the generally developed crusty and comb structures of quartz,the needle and sheet shapes and enriched Mn,Mo,and Ta components of wolframite,we infer that Pingdongling tungsten deposit is a granite-related hydrothermal vein-type tungsten deposit formed at medium-low temperatures.There are still good prospects for the exploration of tungsten,molybdenum,and rare metals in the its deeper portions.This study confirms Late Cretaceous W mineralization in the Jiangnan Orogen which should be given enough attention in future ore exploration.更多还原