云南鲁春VMS锌铅铜多金属矿床的成矿金属来源

摘要

The Luchun VMS Zn-Pb-Cu polymetallic deposit situated in Luchun-Hongponiuchang rift basin in Jinshajiang tectonic zone, is a typical volcanogenic massive sulfide deposit in Sangjiang region, and the ore-bearing horizon is rhyolitic volcanic-sedimentary rocks of the bimodal volcanic rock series.Through the studying of main metallogenic elements, the bimodal volcanic rocks and the REE characteristics of ores, the metallogenic metal source, ore-bearing volcanic rocks and tectonic environment have been discussed.The results showed that the Luchun VMS polymetallic deposit belonged to Zn-Ph-Cu type volcanogenic massive sulfide deposit and occurred in rift basin setting which formed on the thin crust during post-collision orogeny.The value of w (Zn) / w ( Zn +Pb) averaging as 0.64 is close to the Kuroko-type deposit of Japan and Gacun deposit of Sichun; and the ∑REE value ( 15.99 ～ 144.43) × 10-6 is averaging of 73.99 × 10-6, and the LREE / HREE value is 3.59 ～ 11.40,with a mean of 6.30, which showed the typical LREE enrichment.The δEu 0.13 ～0.46 averaging as 0.28, obvious in Eu negative anomaly, is similar to the rhyolites in ore district.The close spatial relationship between rhyolites and ore bodies and the consistency of their geochemical characteristics indicates that the metallogenic metals source was the underlying felsic rocks.%鲁春VMS锌铅铜多金属矿床产于金沙江构造带内鲁春-红坡牛场伸展裂谷盆地中,是三江地区典型的火山成因块状硫化物矿床,其含矿层位为双峰式火山岩系中的流纹质火山-沉积岩系.通过研究该矿床的主成矿元素、双峰式火山岩和矿石的稀土元素特征,对其成矿金属来源、赋矿火山岩及构造环境进行研究表明,鲁春多金属矿床属Zn-Pb-Cu型火山成因块状硫化物矿床,形成于碰撞造山后在薄陆壳(陆缘弧)基底上伸展而成的裂谷盆地环境;矿石的主成矿元素含量特征w(Zn)/w(Pb+Zn)均值为0.64,与日本黑矿和四川呷村矿床较为接近;∑REE为(15.99～144.43)×10<'-6>,平均73.99×10<'-6>,LREE/HREE为3.59～11.40,平均6.30,呈典型的LREE富集型;δEu为0.13～0.46,平均0.28,Eu负异常明显,与矿区流纹岩极为相似.矿体与流纹岩空间上的密切关系以及地球化学特征的一致性表明,成矿金属元素源自下伏的长英质岩系.