内蒙古喀喇沁旗安家营子金矿床热液蚀变过程中元素迁移特征及其地质意义  

Characteristics of element migration during hydrothermal alterationin Anjiayingzi Gold Deposit,Harqin Banner,Inner Mongolia,and its geological significance

作　　者：茹朋 李晓芳 王亚珂 Ru Peng;Li Xiaofang;Wang Yake(Henan Academy of Geology;Henan Key Laboratory of Metallogenic Geological Processes and Resource Utilization;Henan Institute of Geological Sciences Co.,Ltd.)

机构地区：[1]河南省地质研究院 [2]河南省金属矿产成矿地质过程与资源利用重点实验室 [3]河南省地质科学研究所有限公司

出　　处：《黄金》2024年第5期64-72,共9页Gold

基　　金：中国地质调查局项目(DD20221695,DD20190379,DD20160346)。

摘　　要：安家营子金矿床在成矿过程中发生了广泛的热液蚀变作用,蚀变类型从早到晚依次为钠长石化、绢云母化、硅化、黄铁绢英岩化、绿泥石化等。通过对各类蚀变岩样品及其原岩的主量元素、微量元素进行测试分析,详细研究了热液蚀变过程中元素迁移特征。结果表明:(1)主量元素SiO_(2)、CaO、MgO、Fe_(2)O_(3)、TiO_(2)呈现逐渐降低特征;(2)微量元素中大离子亲石元素K、Rb、Th显示出增加趋势,而Sr呈现减少趋势,Bi在所有蚀变中都表现出明显升高特征;(3)稀土元素总量呈现升高趋势;(4)成矿元素Bi、Cu、Zn在黄铁绢英岩化和硅化阶段具有较高的含量。结合岩相学特征,进一步揭示了成矿元素卸载从绢英岩化阶段开始,大量集中在硅化阶段,为矿体定位及圈定提供依据。Extensive hydrothermal alteration occurred to Anjiayingzi Gold Deposit during mineralization.The sequence of alteration types from early to late is albitization,sericitization,silicification,pyrite sericitization,chloritization.Through the analysis of major and micro elements in various altered rock samples and their original rocks,this paper studied the characteristics of element migration during hydrothermal alteration in detail.The results show that①the main elements SiO_(2),CaO,MgO,Fe_(2)O_(3) and TiO_(2) show a gradual decreasing feature;②the large ion lithophile elements K,Rb,Th in the micro elements show an increasing trend,while Sr shows a decreasing trend,and Bi shows an obvious increasing feature in all alterations;③the abundance of rare earth shows an increasing trend;④the ore-forming elements Bi,Cu and Zn have high contents in the pyrite sericitization and silicification stages.Combining with the petrographic characteristics,it is further revealed that the unloading of ore-forming elements starts from the stage of pyritization,and is concentrated in the silicification stage,providing a basis for the positioning and delineation of ore bodies.

关 键 词：热液蚀变 元素迁移 安家营子金矿床 喀喇沁旗 主量元素 微量元素 

分 类 号：TD11[矿业工程—矿山地质测量] P618.51[天文地球—矿床学]