摘要
大尹格庄金矿区位于招平断裂中段中生代玲珑花岗岩与胶东群变质岩接触带,矿体赋存于主裂面下盘黄铁绢英岩化碎裂岩和黄铁绢英岩化花岗岩中。糜棱岩在大尹格庄、夏甸、栾家河等金矿区均有发育,见于招平断裂主裂面上、下盘。糜棱岩中不均匀分布的黏土化、绢英岩化和碳酸盐化蚀变,蚀变岩石中保留的变余眼球状构造和条带状构造表明:糜棱岩是成矿前挤压或剪切应力作用的产物,招平断裂缓倾斜部位形成构造扩容空间,这也是大尹格庄、夏甸等金矿区矿化深度大的原因之一。大尹格庄金矿区成矿期张性断裂活动具体表现为伟晶岩脉、闪长玢岩脉和煌斑岩脉沿张性断裂侵位,沿矿体中的张性裂隙发育金-多金属硫化物-白云石-石英裂隙脉,成矿后期张性裂隙中发育方解石。成矿期张性断裂系统是导矿构造的重要组成部分,招平断裂与张性裂隙系统交汇部为有利的构造扩容和成矿部位。出现在矿体上盘围岩中的伟晶岩脉、闪长玢岩脉和煌斑岩脉,成矿热液活动在矿体上盘张性断裂系统中形成的青磐岩化、绢英岩化和黄铁矿化围岩蚀变,构造地球化学、伽玛能谱等物、化探异常,构成了丰富的多元信息找矿标志。
The Dayingezhuang Gold Deposit is located in the contact zone between the Mesozoic Linglong granite and the metamorphic rock series of the Jiaodong Group in the middle of the Zhaoping fault zone.The gold ore body occurs in the pyrite sericitized cataclastic rock and pyrite sericitized granite in the footwall of the main fracture surface.Mylonite develops in Dayingezhuang,Xiadian,Luanjiahe and other mining districts,and is found at the hanging wall and footwall on the main fracture surface of the Zhaoping fault zone.The uneven distribution of clay,sericitization,and carbonate alteration in mylonites,as well as the remaining ocular structures and banded structures in the altered rocks,indicate that the mylonites are the product of compressive or shear stress prior to mineralization,and the formation of structural expansion space in the gently inclined part of the Zhaoping fault zone is one of the reasons for the great mine-ralization depth of the Dayingezhuang and Xiadian gold deposits.The tensile fault activity during the metallogenic period of Dayingezhuang Gold District is specifically manifested as pegmatite,diorite porphyry and lamprophyre dyke emplacement along the tensile fault,gold-polymetallic sulfide-dolomite-quartz fracture vein develops along the tensile fissures in the ore body and calcite grows in the tensile fissures in the later stage of mineralization.The tensile fracture system in the mineralization period is an important part of the ore-conducting structure.The intersection of the Zhaoping fault zone and the tensile fracture system is a favorable location for structural expansion and mineralization.Pegmatites,diorite porphyries and lamprophyre dykes appearing in the surrounding rocks of the hanging wall of the ore body,the surrounding rock alteration of propylitization and sericitization,pyritization,structural geochemistry,gamma spectroscopy and other geophysical and geochemical prospecting anomalies,constitute wealthy multi-information prospecting signs.
作者
杨斌
周鑫
段磊
王慧
史启发
Yang Bin;Zhou Xin;Duan Lei;Wang Hui;Shi Qifa(School of Geosciences and Info-physics,Central South University;Key Laboratory of Metallogenic Prediction of Nonferrous Metals and Geological Environment Monitoring,Central South University;Shandong Zhaojin Group Co.,Ltd.)
出处
《黄金》
CAS
2020年第9期35-40,共6页
Gold
基金
国家重点研发计划项目(2017YFC0601503)
国家自然科学基金项目(41472301)。
关键词
构造演化
控矿作用
找矿标志
招平断裂
大尹格庄金矿区
tectonic evolution
ore control effect
prospecting indicator
Zhaoping fault zone
Dayingezhuang Gold District
