摘要
黑龙江省勃利双兴地区发育铜多金属矿床,成矿岩体花岗闪长岩、花岗闪长斑岩与铜矿床密切相关。为了确定其成矿时代和地球动力学背景,在野外工作基础上,研究了勃利双兴铜矿区侵入岩的岩相学、年代学及岩石地球化学特征,对研究区侵入岩的形成时代、岩石成因及构造背景进行探讨。结果表明:花岗闪长岩和花岗闪长斑岩的LA-ICP-MS锆石U-Pb年龄分别为(120.94±0.70)、(120.88±0.61)Ma,为中生代早白垩世晚期岩浆作用的产物,指示勃利双兴铜矿床的形成时间略晚于120.9 Ma,与区域成矿高峰期相吻合;花岗闪长岩、花岗闪长斑岩的w(SiO_(2))为61.04%~67.08%,w(Al_(2)O_(3))为14.07%~15.86%,w(Na_(2)O+K_(2)O)为6.40%~7.15%,w(TFeO)为4.52%~6.69%,w(CaO)为2.30%~4.43%,δEu为0.74~1.27,铕异常不明显,富集轻稀土和Rb、Ba、Sr等大离子亲石元素,相对亏损重稀土和Nb、Ta、Zr等高场强元素;岩浆源区可能为新增生下地壳物质的部分熔融,显示出I型花岗岩特征。研究区花岗闪长岩与花岗闪长斑岩形成的动力学背景为古太平洋板块向欧亚板块俯冲碰撞后的岩石圈伸展减薄构造环境。
Cu polymetallic deposits are developed in the Bolishuangxing area,Heilongjiang Province.The ore-forming rock masses(granodiorite and granodiorite porphyry)are closely related to Cu deposits.In order to determine its mineralization era and geodynamic background,based on field survey work,this paper investigate the petrographic,chronological,and geochemical characteristics of intrusive rocks in Cu deposits of Bolishuangxing area,and explores the formation age,petrogenesis,and tectonic background of the intrusive rocks in the study area.The results show that the LA-ICP-MS zircon U-Pb products of Late Mesozoic Early Cretaceous magmatic activity(granodiorite at(120.94±0.70)Ma,granodiorite porphyry at(120.88±0.61)Ma),which indicates that the formation time in Cu deposits of Bolishuangxing area was approximately 120.9 Ma,consistent with the peak period of mineralization in the region.Research on rock geochemistry shows that granodiorite and granodiorite porphyry contain(w(SiO_(2))(61.04%67.08%),w(Al_(2)O_(3))(14.07%15.86%),w(Na_(2)O+K_(2)O)(6.40%7.15%),w(TFeO)(4.52%6.69%),w(CaO)(2.30%4.43%),δEu(0.741.27)),the europium anomaly is not obvious.They are enriched in light rare earth elements and large ion lithophile elements(Rb,Ba,Sr,etc.),and relatively deficient in heavy rare earth elements and high field strength elements(Nb,Ta,Zr,etc.).The magma source area is partial melting of newly enriched lower crustal material,showing I type granite characteristics.Based on relevant research results,it is considered that the geodynamic setting of the formation of granodiorite and granodiorite porphyry in the study area is an extensional environment formed by the subduction and retreat of the ancient Pacific plate towards the Eurasian continent.
作者
于喜洹
崔锡彪
陆胜
李新鹏
贾宏
孙江军
谷华娟
王野
Yu Xihuan;Cui Xibiao;Lu Sheng;Li Xinpeng;Jia Hong;Sun Jiangjun;Gu Huajuan;Wang Ye(Natural Resources Survey Institute of Heilongjiang Province,Harbin 150036,China;The Fifth Geological Exploration Institute of Heilongjiang Province,Harbin 150090,China;Heilongjiang Province Geophysical and Geochemical Survey Institute,Harbin 150030,China)
出处
《吉林大学学报(地球科学版)》
北大核心
2025年第4期1143-1162,共20页
Journal of Jilin University:Earth Science Edition
基金
中国地质调查局项目(12120113057611)
黑龙江省地质勘查基金项目(SDKC-2018002)。
关键词
早白垩世
地球化学
侵入岩
岩石成因
俯冲
勃利双兴铜矿床
Early Cretaceous
geochemistry
intrusive rocks
petrogenesis
sbduction
Cu deposits of Bolishuangxing area
