黑龙江258高地金矿区侵入岩锆石U-Pb年代学及地球化学特征  

Zircon U- Pb chronology and geochemical characteristics of intrusive rocks in No.258 Hill gold deposit, Heilongjiang Province

作　　者：谈艳[1,2] 杨言辰[1] 王建[1] 黄永卫 全传顺 

机构地区：[1]吉林大学地球科学学院,吉林长春130061 [2]青海省地质调查局,青海西宁810000 [3]黑龙江省第一地质勘察院,黑龙江牡丹江157011

出　　处：《矿床地质》2016年第4期737-757,共21页Mineral Deposits

基　　金：中国地质调查局地质调查项目(编号:1212011120342;1212010786005)的资助

摘　　要：258高地金矿床地处黑龙江省完达山成矿带东部,矿化与岩浆侵入活动密切相关。文章利用锆石LA-ICP-MS U-Pb定年方法,对258高地金矿区的二长花岗岩、花岗闪长岩及闪长玢岩进行了年代学研究,获得258金矿区花岗闪长岩的成岩年龄为（118.3±1.1）Ma;3件二长花岗岩样品的成岩年龄分别为（130.5±0.8）Ma、（122.1±0.7）Ma、（118.0±0.9）Ma;2件闪长玢岩的成岩年龄分别为（119.5±1.3）Ma、（107.4±2.2）Ma,表明本区中酸性岩体侵位时代介于131～107 Ma,与西太平洋构造域的早白垩世演化有关。定年结果同时表明矿区存在3期岩浆活动,其中122～118 Ma的二长花岗岩与花岗闪长岩、闪长玢岩的年龄在误差范围内一致,且与金矿成矿关系密切。岩石地球化学显示区内的中酸性侵入岩均为高钾钙碱性过铝质岩石,花岗闪长岩和二长花岗岩具有重熔型岩浆岩的特征,可能是加厚地壳物质部分熔融的产物;闪长玢岩脉具有典型壳幔源岛弧岩浆岩的特点。综合研究认为258高地金矿床形成于与板块俯冲有关的活动大陆边缘环境。The No. 258 Hill gold deposit is located in the eastern part of the Wandashan metallogenic belt, and the gold mineralization is closely related to the magmatic intrusion activities. The authors conducted the U-Pb dating of the zircons from granodiorite, monzogranite, and diorite porphyry by LA-ICP-MS. LA-ICP-MS zircon U-Pb dating shows that the ages of granodiorite, three pieces of monzogranite samples, and two pieces of diorite porphyre samples are （118.3±1.1） Ma, （130.5±0.8） Ma, （122.1±0.7） Ma, （118.0±0.9） Ma, and （119.5 ±1.3） Ma, （107.4 ± 2.2） Ma, respectively. The result demonstrates that the emplacement of intermediateacidic magma activities occurred between 131 and 107 Ma, due to the subduction of Western Pacific during the Early Cretaceous. Meanwhile, there are three obvious magma intrusive activities in the ore district, the ages （122-118 Ma） of granodiorite, monzonitic granite and diorite porphyrite are consistent in the error limits, and are closely associated with gold mineralization. The intermediate-acid intrusive rocks are chemically high-K calc-alkaline rock and peraluminous, the granodiorite and monzonitic granite are characterized by partial melting of thickened crust, which might be the product of thickened crust material. And the diorite porphyrite is the typical mantle source arc magmatic rocks. It is considered that the No. 258 Hill gold deposit formed in a continental margin environment related to the subduction of the Pacific plate.

关 键 词：地球化学 中酸性侵入岩 锆石U-PB定年 258高地金矿床 完达山成矿带 

分 类 号：P618.51[天文地球—矿床学]