广西佛子冲矿田大冲花岗闪长岩锆石SHRIMP U-Pb定年及其地质意义

本文对佛子冲铅锌矿床北部早前认为的成矿花岗岩——大冲岩体进行了年代学研究,获得花岗闪长岩锆石SHRIMPU—Pb年龄为258.2±3.2Ma(95%置信度,MSWD=0.59),证明大冲岩体形成时代不是原来认为的燕山早期,而是属于海西期。同时结合区域上海西期岩体不成矿的认识和矿床地质特征,本文认为成矿岩体不是大冲岩体,而是燕山期花岗斑岩群,它们和铅锌矿化一起明显受到牛卫断层系统控制。

Zircon SHRIMP U-Pb Dating of Dachong Granodioritic Stock and Its Geological Significance in Fozichong Deposit, Guangxi Province

Zircon SHRIMP U-Pb dating of Dachong granodoirite in Fozichong deposit, Guangxi province, is conducted in this paper, yielding an age of 258.2± 3.2 Ma (95% confidence, MSWD=0.59). The result shows Daehong stock intruded at shallow place in Hecynian, not late Yanshanian constrainted by former researchers. Compiled with regional metallogenic rule of "no Hecynian mineralization" and geological characteristics of this deposit, we support metallogenic granite is not Dachong granodoiritic stock, but Yanshanian granitic porphyry dike swarm. The Yanshanian granitic porphyry together with Pb, Zn mineralization, were obvious controlled by Niuwei fault system.