黔西南泥堡金矿床构造特征及其控矿作用  

Characteristics and Ore-controlling Significance of Structures in the Nibao Gold Deposit,Southwestern Guizhou

作　　者：蔡明海 肖俊杰 彭振安 胡志戍 李晔 胡鹏飞 CAI Minghai;XIAO Junjie;PENG Zhen’an;HU Zhishu;LI Ye;HU Pengfei(School of Resources,Environment and Materials,Guangxi University,Nanning 530004,Guangxi,China)

机构地区：[1]广西大学资源环境与材料学院,广西南宁530004

出　　处：《大地构造与成矿学》2022年第1期48-62,共15页Geotectonica et Metallogenia

基　　金：企业项目“贵州泥堡金矿找矿综合研究”资助。

摘　　要：位于扬子板块西南缘的右江盆地是我国卡林型金矿的集中分布区之一,素有滇-黔-桂“金三角”之称。泥堡金矿是右江盆地西北侧一个大型矿床,矿区构造主要有NEE向泥堡背斜、二龙抢宝背斜和同方向的F_(1)、F_(3)、F_(4)、F_(5)和F_(9)断层,以及产于F_(1)断层下盘的层间破碎带等。详细构造调查和新近勘查资料的综合研究表明:F_(1)、F_(5)和F9为逆冲断层,F_(3)和F_(4)为正断层,二龙抢宝背斜属断展褶皱。由F_(1)、F_(5)、F_(9)逆冲断层以及二龙抢宝背斜所组成的NEE向冲断-褶皱构造是矿区主要控矿构造,其次为F_(1)断层下盘的层间破碎带控矿。其中,F_(1)断层中赋存有占全区资源储量80%的Ⅲ号主矿体,是矿区最主要的导矿和容矿构造,且断层倾向上由陡变缓部位为有利的赋矿部位。区内构造活动先后经历了早期挤压、中期拉张和晚期再次拉张的作用过程。其中,前两期构造活动与金成矿关系密切,分别控制了泥堡矿区第一期和第二期成矿,两期成矿的构造作用环境可能分别对应于燕山早期的挤压和燕山晚期的伸展。晚期构造作用形成的F_(3)正断层破坏矿体并造成了上盘矿体断失。F_(1)断层中的矿体具有向西侧伏特点,F_(3)正断层铅直地层断距约400 m,因此,F_(1)断层西段的深边部和F_(3)断层的上盘可作为矿区今后的探矿方向。The Youjiang Basin,located in the southwestern margin of the Yangtze Plate,is one of the ore concentrated areas of Carlin type gold deposits in China.It is often referred to as“Golden Triangle”,situated on the bordering area of Yunnan,Guizhou and Guangxi provinces.The Nibao gold deposit is a large deposit in the northwestern of the Youjiang Basin.The main structures include the NEE-trending Nibao and Erlongqiangbao anticlines,NEE-trending F_(1),F_(3),F_(4),F_(5) and F_(9) faults,as well as bedding fracture zones in the footwall of the F_(1) fault.Based on the detailed field structural investigation and comprehensive study of recent exploration data,we suggest that the F_(1),F_(5) and F_(9) faults are a group of thrust faults,the F_(3) and F_(4) faults are normal faults,whereas the Erlongqiangbao anticline belongs to a fault propagation fold.The ores are mainly controlled by the NEE thrust-fold structure composed of the F_(1),F_(5) and F_(9) thrust faults and the Erlongqiangbao anticline,followed by the bedding fracture zones among the footwall of the F_(1) fault.Among them,the F_(1) fault is the most important ore-conducting and ore-hosted structure.The ore bodyⅢoccurs in the F_(1) fault zone,accounting for 80%of the total reserves.The region underwent three stages of tectonic movement:(a)the early SN nearly extrusion;(b)the NE-SW tension,and(c)NE-SW tension again in the final stage.The first two periods were closely related to gold mineralization,corresponding to the early Yanshanian compression and the late Yanshanian extension.While the final stage exhibits mainly as structural destruction of the ore bodies.The study of mineralization alteration and structural characteristics shows that the pitch direction of the orebodies in the F_(1) fault is westward.And the vertical fault displacement of the F_(3) normal fault in the final stage is about 400 m.Therefore,the deep part of the western section of the F_(1) fault and the upper wall of the F_(3) fault might be the most favorable prospecting locations.

关 键 词：冲断-褶皱构造 构造控矿 矿体侧伏 黔西南泥堡金矿床 

分 类 号：P613[天文地球—矿床学] P612[天文地球—地质学]