黑龙江三道湾子金矿床锆石U-Pb年龄及其地质意义

来源期刊：黄金2011年第5期

论文作者：陈静 孙丰月

文章页码：18 - 22

关键词：锆石U-Pb年龄； 地质意义； 三道湾子金矿床

Key words：Zircon U-Pb ages； geological significance； Sandaowanzi gold deposit

摘    要：通过LA-ICP-MS锆石原位定年方法,对黑龙江三道湾子金矿床附近的二长花岗岩(三道湾子岩体)和闪长玢岩脉进行了年龄测定。结果显示,原定晚三叠世的二长花岗岩锆石U-Pb年龄为(188.7±1.7)Ma,与区内同期侵入岩及一系列斑岩型、矽卡岩-热液型铜钼铁铅锌矿床共同记录了本区早侏罗世一次重要的成岩成矿事件,该期岩浆热液活动可能与太平洋板块俯冲引起的地壳加厚有关。闪长玢岩脉锆石U-Pb年龄为(112.2±1.0)Ma,为成矿期脉岩,与区内众多中—超大型浅成低温热液型金矿床同期,代表了早白垩世中晚期岩石圈大规模伸展减薄的动力学环境。

Abstract: LA-ICP-MS zircon dating on adamellite and diorite-porphyrite near Sandaowanzi gold deposit is carried out.The results show that,the age of adamellite is(188.7±1.7)Ma.Together with other synchronous intrusive rocks and associated porphyry,skarn-hydrothermal copper molybdenum iron lead-zinc deposits,they recorded an important diagenesis mineralization event in Early Jurassic,and the magmatic hydrothermal action in this stage may relate to the Pacific plate subduction and crustal thickening.The age of diorite-porphyrite is(112.2±1.0)Ma.It formed in the metallogenic period,and was synchronous with other middle-large scale epithermal gold deposits in the area.It implies the large-scale lithospheric extending and thinning in the Early Cretaceous.