云南个旧某铅锌多金属矿地球物理特征及找矿方向

Geophysical Characteristics and Prospecting Direction of a Pb-Zn Polymetallic Deposit in Gejiu City,Yunnan Province

个旧某铅锌多金属矿位于个旧西部石门坎—保和地区,大地构造位置上处于环太平洋成矿带与地中海—喜马拉雅成矿带的交汇处,为印度板块、欧亚板块、太平洋板块的碰撞相接部位。结合相关地质工作成果,对个旧矿区西部石门坎—保和地区地层、构造、岩浆岩等产出特征进行了分析,在此基础上,采用EH-4磁探等工程手段,对石门坎地段和咪甲冲地段进行了勘探,并对磁异常进行了解译。研究表明:(1)矿区有利的找矿标志为个旧组地层大理岩出露地段,大理岩地层节理裂隙发育地段,NE向断裂与NW向断裂交汇地段,Zn、Cu叠加异常区域以及Zn、Cu叠加异常与断裂构造复合部位;(2)杨家田断裂带为区内多金属矿床的导矿构造,控制着区内矿体的形成与产出;(3)保和—咪甲冲一带为找矿靶区,在地表多有菱锌矿出露,矿体规模小且分布较分散,成矿深度为200~600 m。

A Pb-Zn polymetallic deposit in Gejiu City is located in Shimenkan-Baohe area in the west of Gejiu mining area, its geotectonic position is the intersection area of Circum-Pacific metallogenic belt and Mediterranean-Himalayan metallogenic belt, it is also the collision junction belt of India Plate, Eurasia Plate and Pacific Plate. Based on the geological working results of Shimengkan-Baohe area, char- acteristics of formation, structure and magmatic rock are discussed, based on the discussion results, EH-4 magnetic prospecting method is adopted in Shimenkan area and Mijiachong area, besides that,the magnet- ic anomalies are delineated and interpreted. The study results show that：①the favorable prospecting indi- cators of the area can be summarized as the exposed area of marble of Gejiu Formation, development area of joint fractures in marble formation, intersection area of NE trending fault and NW trending fault, super- imposed anomaly of Zn and Cu, composition area of the superimposed anomaly of Zn and Cu and faults ; ②Yangjiatian fault belt is the ore conducting structure of polymetallic deposit in the area, the formation and distribution of the polymetallic deposit in the area is controlled by Yangjiatian fault belt; ③Baohe-Mijia- chong area can be taken as the prospecting target area,there is bonamite outcrops on the surface,sacle of the ore-body is small and they are distributed dispersedly,the metallogenic depth is 200-600m.