内蒙古扎赉特旗神山铁铜矿床成岩成矿年代学及其地质意义

内蒙古神山铁铜矿床是大兴安岭中段具有代表性的矽卡岩型铁铜矿床。笔者就该矿床成矿岩体的地球化学及锆石LA-ICP-MS U-Pb年代学开展相关研究。研究表明：矿区中与成矿有关的伊力特岩体岩石类型为英云闪长岩，属I型花岗岩类，铝过饱和，高钾钙碱性系列和磁铁矿系列；岩石富集轻稀土（LREE）、大离子亲石元素（LILE），亏损高场强元素（HFSE），铕异常不明显（δEu为0.97~1.17），存在弱铈异常（δCe为0.86~0.92）；锆石LA-ICP-MS U-Pb测年显示，与成矿有关的伊力特岩体形成于晚侏罗世（（155.3±1.3）Ma），因此推测神山铁铜矿床成矿时代为晚侏罗世。综合研究认为神山铁铜矿床形成于地壳加厚和构造活化的构造环境。

Geochronology and Metallogenic Epoch of Shenshan Fe-Cu Deposit in Zhalaite County,Inner Mongolia and Its Geological Significance

The Shenshan Fe-Cu deposit is the only skarn Fe-Cu deposit discovered in the Middle Great Hinggan Mountains, Inner Mongolia. We focused on the geochemistry features and zircon LA-ICP-MS U-Pb chronology of the intrusions related to the mineralization of the deposit. The Yilite intrusion in Shenshan district is of tonalite, potash rich calc-alkali and magnetite series. The tonalite is characterized by peraluminous, enriched in light rare earth elements, large ion lithophile elements, depleted of high field-strength elements. Its Ce anomalies (δCe) are 0.86-0.92 with no Eu anomalies (δEu of 0.97-1.17). The Zircon LA-ICP-MS U-Pb yields a concordant age of (155.3±1.3) Ma, which reveals that the Yilite intrusion formed in Late Jurassic. The results also show that the Shenshan Fe-Cu deposit was mineralized in Late Jurassic. The geochemistry characteristics of the Yilite intrusion reveal a tectonic setting of thicken crust and tectonic activation in Late Jurassic.