江西朱溪铜钨矿床成因:来自矿物学和年代学的启示

江西景德镇朱溪铜钨矿床是近年来发现的一个世界级超大型铜钨矿床。矿床地质特征、矽卡岩矿物学和成矿岩体年代学的研究表明，矿体赋存于上石炭统黄龙组大理岩与新元古界双桥山群变质岩之间的不整合界面之上，空间上具有明显的矿物组合分带特征。根据矽卡岩产状、矿物共生组合和相互关系，把成矿作用划分为矽卡岩阶段、退化蚀变阶段、石英-硫化物阶段、碳酸盐-萤石阶段。代表性的矽卡岩矿物组合有石榴子石、透辉石、透闪石、硅灰石、符山石、蛇纹石、绿泥石等。电子探针分析表明，石榴子石为钙铝榴石—钙铁榴石系列，辉石为透辉石—钙铁辉石系列。同位素年代学及岩浆与成矿关系的研究表明：花岗闪长岩与早期矽卡岩型矿化相关，矿化范围较小，矿石品位较低；黑云母花岗岩与云英岩型和晚期矽卡岩型的矿化相关，矿化范围较广，矿石品位较高，并获得黑云母花岗岩LA-ICP-MS锆石U-Pb年龄为（147.7±2.2）Ma。综合分析指出，朱溪铜钨矿床为晚侏罗世花岗岩浆有关的热液与晚古生代碳酸盐岩发生多阶段交代作用而形成，成矿作用以矽卡岩型和云英岩型为主。

Genesis of Zhuxi Copper-Tungsten Deposit in Jiangxi Province: Insights from Mineralogy and Chronology

The Zhuxi deposit is located in Jingdezhen in Jiangxi Province, which is a world-class super large copper-tungsten deposit,and its genesis remain debated. The research on the geological characteristics, skarn mineralogy and ore-bearing rock chronology show that the orebodies occur in the unconformity interface between the marble of the Upper Carboniferous Huanglong Group and the metamorphic rocks of the Neoproterozoic Shuangqiaoshan Group, and have significant mineral assemblage zonage with the surrounding rocks. According to the skarn occurrence, mineral association, metasomatic and petrographic characteristics, from early to late the mineralization was divided into skarn stage, retrograde alteration stage, quartz-sulfide stage, and carbonate stage. The representative skarn minerals are garnet, diopside, tremolite, wollastonite, vesuvianite, serpentine, chlorite, etc. The electron microprobe analysis shows that the garnet belongs to grossularite-andradite series, and the pyroxene mainly belongs to diopside-andradite series. The study of isotopic chronology and the relationship between magma and mineralization show that the granodiorite is related to the early skarn-type mineralization, and its scale is smaller and the ore grade is low;the biotite granite is related to the greisen-type and late skarn type mineralization with a wide scale and high ore grade. The result of LA-ICP-MS zircon U-Pb dating of the biotite granite is (147.7±2.2)Ma. The comprehensive analysis shows that the Zhuxi copper-tungsten deposit is formed by the multi-stage metasomatism of the Late Jurassic granitic magma related hydrothermal and Late Paleozoic carbonate rocks, and the mineralization is characterized by skarn-type and greisen-type mainly.