冀东高家店岩体锆石年代学和微量元素地球化学特征及其地质意义  

Zircon Chronology and Trace Element Geochemical Characteristics and Their Geological Significance of Gaojiadian Pluton in Eastern Hebei Province,China

作　　者：杨爱雪 吕水 许曼 韦文国 刘海龙[1] 吴再忠 安梦莹 Yang Aixue;LüShui;Xu Man;Wei Wenguo;Liu Hailong;Wu Zaizhong;An Mengying(The Fifth Geological Brigade of Hebei Bureau of Geology and Mineral Resources Exploration(Hebei Marine Geological Environment Survey Centre),Tangshan 063000,Hebei,China)

机构地区：[1]河北省地质矿产勘查开发局第五地质大队(河北省海洋地质环境调查中心),河北唐山063000

出　　处：《吉林大学学报(地球科学版)》2025年第2期503-524,共22页Journal of Jilin University:Earth Science Edition

基　　金：河北科技厅重点研发项目(22374201D);河北省自然资源厅科研项目(13000024P00F2D410444H);河北省地质矿产勘查开发局科研项目(13000022P0069B410037Y)。

摘　　要：高家店岩体地处华北克拉通北缘冀东地区,为早燕山期侵入的复式岩基,岩石类型主要包括闪长岩、石英正长岩、花岗岩及其间的过渡类型。岩体内部赋存有高家店热液脉型金矿床,花岗岩和闪长岩是金矿的主要赋矿围岩。为精确厘定高家店岩体侵入期次,以高家店岩体为研究对象,采用LA-ICP-MS锆石U-Pb测年方法对高家店岩体4件岩石样品进行锆石年代学研究和锆石微量元素测试。结果显示:石英正长岩结晶年龄为(197.4±1.9)Ma,肉红色黑云二长花岗岩结晶年龄为(176.7±1.2)Ma,灰白色黑云二长花岗岩结晶年龄为(175.8±1.7)Ma,闪长玢岩结晶年龄为(175.3±1.9)Ma,表明高家店岩体的侵入时代为早—中侏罗世;花岗岩内见有闪长岩暗色包体,说明岩体可能为壳-幔混合成因,形成于伸展构造背景下;所有样品锆石微量元素均表现出左倾稀土元素配分模式,具有较强的Ce正异常和不同程度的Eu负异常,锆石饱和温度介于682~824℃之间,代表了岩浆形成的初始温度;岩浆具有随时间的演化温度逐渐降低的特征,与区域岩浆锆石具有相同的配分模式和结晶温度范围,锆石Ce^(4+)/Ce^(3+)值较高,代表了相对较高的氧逸度,暗示高家店岩体较强的成矿潜力,尤其黑云二长花岗岩更为突出。The Gaojiadian pluton,located in the eastern Hebei Province on the northern margin of the North China craton,is a composite batholith that intruded during the early Yanshan period.It primary rock types include diorite,syenite,granite,with transitional varieties present.The pluton hosts hydrothermal vein-type gold deposits,primarily found in granite and diorite.To accurately determine the invasion period of the Gaojiadian pluton,four rock samples were analyzed by zircon chronology and trace element characteristics using LA-ICP-MS zircon U-Pb dating.The results indicate crystallization age of(197.4±1.9)Ma for quartz syenite,(176.7±1.2)Ma for fleshy-red biotite monzonitic granite,(175.8±1.7)Ma for gray-white biotite monzonitic granite,and(175.3±1.9)Ma for diorite-porphyrite,suggesting an intrusion age from the Early to Middle Jurassic.Dark diorite enclaves within the granite imply a mixed crust-mantle origin formed in an extensional tectonic setting.Zircon trace elements of all samples exhibit a left-leaning rare earth partitioning pattern with strong Ce positive anomalies and varying degrees of Eu negative anomalies.The zircon saturation temperature ranges from 682 to 824℃,representing the initial magma formation temperature.The magma exhibited a gradual cooling trend over evolutionary time and shares a similar partitioning pattern and crystallization temperature range with regional magmatic zircons.The high Ce^(4+)/Ce^(3+)values of zircon represent relatively high oxygen fugacity,revealing the stronger mineralization potential of the Gaojiadian pluton,especially in the biotite monzonitic granite.

关 键 词：高家店金矿床 热液脉型 锆石U-PB定年 锆石微量元素 氧逸度 地球化学 高家店岩体 冀东 

分 类 号：P595[天文地球—地球化学] P588.1[天文地球—地质学]