东昆仑东段果洛龙洼脉状金矿床断裂构造控矿规律  

Ore Controlling Regularities of Fault in the Guoluolongwa Lode Gold Deposit,East Segment of Eastern Kunlun Orogen

作　　者：唐洋[1] 付乐兵[1] 杨宝荣 祁月清 谢智勇 李文君 马忠贤 

机构地区：[1]中国地质大学(武汉)资源学院,武汉430074 [2]青海省有色地质矿产勘查局,西宁810007

出　　处：《地质科技情报》2017年第2期160-167,共8页Geological Science and Technology Information

基　　金：国家自然科学基金项目(41302065);中国地质调查局整装勘查区关键基础地质研究;找矿预测与技术应用示范项目(12120114081401);中国地质调查局项目"青海省东昆仑典型金矿床成矿控制条件与找矿方向综合调查"(12120114000701)

摘　　要：果洛龙洼金矿床位于东昆仑成矿带东段,为该成矿带内典型的大型脉状金矿床。笔者采取大比例尺构造-蚀变填图、坑道-岩心综合调查等手段对矿区构造系统进行了解剖,将矿区主要构造活动由早到晚分为4个期次:东西向左行韧性剪切、东西向右行韧性剪切、东西向逆断裂和东西向正断裂。基于矿体与构造的时空关系,确定中-晚三叠世南北向挤压应力场作用下形成的东西向脆性逆冲断裂为矿区成矿期构造。该期断裂是早燕山期昆中断裂带活动形成的次级断裂。矿区内,自含矿断裂向外,矿化和蚀变的发育程度随构造变形强度的减弱而依次降低,因此,矿体附近发育的钾化、绿帘石化和黄铁绢英岩化可作为该类矿床找矿标志。受断裂控制,矿区矿体平面上呈东西走向;剖面上可见矿体在产状变缓处膨大,在产状变陡处收敛甚至尖灭;纵投影剖面垂向上,矿体具有南东侧伏的规律,单个矿体侧伏角约75°,矿化在3 400m和3 700m标高分2个富集带,标高下限由西向东逐步降低,矿化富集带侧伏角约3°。基于以上认识,构建了矿区三维矿化富集规律模型,认为在矿区深部有较大找矿潜力。Guoluolongwa gold deposit, located in the east segment of eastern Kunlun orogen, is a typical large lode gold deposit. We made large-scale structure-alteration investigation and mine channel and core observations in the mine area for the research of structural ore control system. There are four tectonic ac- tivities： EW left-ductile shearing, EW right-ductile shearing, EW reverse fault and EW normal fault. The spatiotemporal relationship between orebodies and structure indicates that the third EW brittle reverse fault formed in T2- T3 by NS compressive stress field is the ore-forming structure. The fracture is the sec- ondary fault of the middle Kunlun fault activity in early Yanshanian. Alteration and mineralization are weakened from the fault inside out. Therefore, the rock alteration of potassic alteration, epidotization and pyrito-sericitoquartzitization near the ore body could be prospecting criteria. Due to the ore-controlling structure nature, there are some ore controlling regularities of structure. In surface, ore body strike is EW. In sectional direction, ore body is large at slow occurrence and converges in steep place. In vertical projection, the orebody has lateral trending with a plunge angle 75° from west to east. Mineralization has two enrichment zones in elevation of 3 400 m and 3 700 m. The height of mineralization is gradually de- scending from west to east of lateral trending with a plunge angle 3°. Based on the above understanding, we have built a 3D model of mineralization enrichment, and assume it has good prospecting potential in the deep mining area.

关 键 词：脉状金矿床 断裂构造控矿 果洛龙洼 东昆仑东段 

分 类 号：P618.51[天文地球—矿床学]