小秦岭地区樊岔金矿基性岩脉年代学特征及地质意义  

Chronological characteristics of basic dikes in Fancha Au deposit in Xiaoqinling area and the geological significance

作　　者：郭晓 李重阳 王红军 祖宗虎 李满军 裴海洋 GUO Xiao;LI Chongyang;WANG Hongjun;ZU Zonghu;LI Manjun;PEI Haiyang(Lingbao Jinyuan Mining Co.Ltd.,Lingbao 472500,Henan,China;Henan First Geology and Mineral Survey Institute Co.,Ltd.,Luoyang 471023,Henan,China;Key Laboratory of Gold and Silver Polymetallic Ore-forming Series and Deep Predictionof Henan Province,Luoyang 471023,Henan,China)

机构地区：[1]灵宝金源矿业股份有限公司,河南灵宝472500 [2]河南省第一地质矿产调查院有限公司,河南洛阳471023 [3]河南省金银多金属成矿系列与深部预测重点实验室,河南洛阳471023

出　　处：《地质找矿论丛》2024年第3期334-343,共10页Contributions to Geology and Mineral Resources Research

基　　金：国家重点研发计划项目(编号:2016YFC0600600);河南省科技攻关项目(编号:202102310290);灵宝金源矿业股份有限公司科研项目“河南省灵宝市金源二矿南部矿区三维地质建模及深部找矿预测”联合资助。

摘　　要：小秦岭地区位于华北克拉通南缘秦岭造山带的北部,是区域构造运动、岩浆活动及成矿作用的典型区域。该区自太古代以来经历了长期、复杂的岩浆-构造演化过程,形成了多种基性岩脉。这些基性岩脉在时间上及空间上与区内花岗岩体及金矿脉表现出一定的穿插或伴生关系,这对于探讨区域岩浆活动、成矿作用等具有十分重要的指示意义。本文对小秦岭东部樊岔金矿区内的基性岩脉开展了锆石U-Pb同位素年代学研究工作,结果表明:基性岩脉的锆石分为岩浆锆石与继承锆石两类,其中继承锆石的同位素年龄为2430 Ma—2029 Ma,与区内基底太华群的形成年代近于一致,指示其形成过程中捕获了部分太古代太华群的锆石;岩浆锆石同位素年龄集中在1866 Ma—1803 Ma,属中元古代,与区内广泛发育的熊耳群火山岩及部分花岗岩(桂家峪岩体、小河岩体)形成时代近于一致,是中元古代时期华北克拉通发生拉张、裂解等构造背景下的产物;区内发育的基性岩脉集中于元古代时期,而区内大规模成矿作用发生在中生代,因此,在时间上基性岩脉与区内中生代成矿事件的成因联系较弱。The Xiaoqinling area is located in the northern part of Qinling orogenic belt on the southern margin of North China Craton,and typical in regional tectonic movement,magmatic activity and mineralization.This area has experienced a long and complex magma-tectonic evolution since Archean with a variety of basic dikes formed.The dikes are associated with granites and gold veins in time and space or show cut across relationship.Zircon U-Pb isotope chronology of the basic dikes in the Fancha gold deposit area in the eastern Xiaoqinling has been studied.The zircons of the basic dikes are divided into magmatic zircons and inherited zircons.The isotopic age of the inherited zircons is 2430 Ma~2029 Ma basically coincided with that of the basement Taihua Group indicating that some of the zircons were captured from Taihua Group,the magmatic zircon 1866 Ma~1803 Ma corresponding to Mesoproterozoic Era and coincided with those of the widely developed volcanic rocks and some granites in the Xionger Group(Dujiayu pluton and Xiaohe Pluton).The volcanics and grantite are the product of the stretching and cracking of the North China craton in the Middle Proterozoic period.Both age of the inherited and granitic zircons are all formed in Proterozoic period.However large scale mineralization took place in Mesozoic era.Therefore,the genetic relationship between the basic dikes and the Mesozoic mineralization events is weak in time.

关 键 词：樊岔金矿 基性岩脉 锆石U-PB同位素年代学 河南小秦岭 

分 类 号：P618.51[天文地球—矿床学] P597[天文地球—地质学]