福建省泰宁县何宝山金矿床长兴岩体锆石LA-ICP-MS U-Pb年龄及其地质意义  

LA-ICP-MS zircon U-Pb dating and geological features of Changxing intrusion in the Hebaoshan gold deposit, Taining County, Fujian Province

作　　者：陈国建[1] 张伟波[2] 刘江涛[2] 

机构地区：[1]福建省闽北地质大队,福建福州350002 [2]中国地质调查局发展研究中心,北京100037

出　　处：《中国地质》2015年第2期547-555,共9页Geology in China

基　　金：中国地质调查局项目(1212011085534)资助

摘　　要：长兴钾长混合花岗岩体与何宝山金矿床的成矿作用关系密切。何宝山金矿床的成矿作用表现出多期次、多阶段的特点,加里东晚期长兴岩体的侵入活动促进了金矿床成矿物质早期的迁移和富集,印支晚期—燕山早期的构造-岩浆活动叠加成矿。文中对区内加里东期主要侵入岩体进行了锆石LA-ICP-MS U-Pb同位素定年研究,得出长兴岩体的成岩年龄为(437.1±1.3)Ma,黑云母石英闪长岩成岩年龄为(436.6±1.1)Ma,黑云母花岗闪长岩脉成岩年龄为(427.1±1.4)Ma,从而确定金矿床成矿期上限,为进一步成矿作用研究提供科学依据。The Changxing potash feldspar migmatitic granite is related to the mineralization in the Hebaoshan gold deposit. The mineralization in the Hebaoshan gold deposit shows multi- period and multi- stage characteristics, and the intrusion activities of Changxing potash feldspar migmatitic granite in the late Caledonian promoted the early period migration and enrichment of the oreforming elements in the gold deposit and the tectonic- magmatic activity of the late Indosinian to early Yanshanian superimposed mineralization. The authors made a detailed chronological study of the main intrusive rocks formed in the Caledonian period. Insitu zircon U- Pb dating was performed with LA-ICP-MS, and reliable n（^206Pb）/n（^238U） age data of zircons were obtained. The results yielded concordant age of（437.1 ± 1.3） Ma for potash feldspar migmatitic granite,（436.6 ± 1.1） Ma for biotite quartz diorite and（427.1 ± 1.4） Ma for biotite granite diorite vein. The age data constrain the upper limitation of the metallogenic period, thus having great geological implications for further mineralization research.

关 键 词：何宝山金矿床 长兴岩体 U-Pb同位素年代 成矿时限 

分 类 号：P597.3[天文地球—地球化学] P618.51[天文地球—地质学]