云南姚安老街子铅银矿床岩性-断裂控矿特征与找矿预测—以2108m中段为例  

Lithology-Fault Ore-Controlling Characters and Prospecting Prediction of the Laojiezi Pb-Ag Deposit in Yaoan,Yunnan Province: A Case Study of the 2108m Level

作　　者：王建飞[1] 吴鹏[1] 姜龙燕 管申进[1] 江小均[1] 孙春迪 

机构地区：[1]昆明理工大学有色金属矿产地质调查中心西南地质调查所,云南昆明650093 [2]悦达矿业控股有限公司,云南昆明650093

出　　处：《地质与勘探》2016年第3期407-416,共10页Geology and Exploration

基　　金：国家自然科学基金项目(编号:41102049);矿床地球化学国家重点实验室开放基金项目(编号:201109);云南省矿产资源预测评价工程实验室及昆明理工大学创新团队项目联合资助

摘　　要：云南姚安铅银矿床与富碱斑岩、构造活动密切相关。在矿床深部2108m中段开展大比例尺地质填图,选取3号、5号穿脉建立岩性-断裂地质剖面,分析岩性-断裂控矿特征,总结铅矿化规律,提出深部找矿预测区。研究认为,条带状、网脉状铅矿脉主要分布于肉红—灰白色正长斑岩内NE向断裂或不同方向断裂交汇处;NE向灰紫色黑云母正长斑岩脉、灰白色正长斑岩脉上盘,铅矿脉变厚、加富,岩脉侵入正长斑岩较侵入砂岩,铅矿化更强。隐爆角砾岩(筒)中方铅矿呈细脉状、散点状及浸染状,沿角砾裂隙及角砾的边缘充填,深部铅矿化加强。早期NNW向背斜与一系列NW向扭—扭张性断裂(F3、F4),限制了矿床就位的空间,总体控制矿床展布;后期NE—SW向主应力作用形成的NE向张性空间(F1及NE向断裂、岩脉)为矿区火成岩喷溢和矿液上升提供了通道,是主要的成矿构造,控制铅矿脉、正长斑岩脉产出。正长斑岩脉与断裂的空间位置一致,产状一致,岩脉上盘矿化强、品位高,构造—岩脉—矿化三者耦合作用,具密切的时空关系与成因联系。铅矿化为岩浆期后热液沿断裂充填作用产物,同时或稍晚于岩脉就位。姚安老街子铅银矿体主要受岩性、构造控制。总结了岩性-断裂控矿特征及铅矿化规律,提出四个深部找矿预测区。The Yao＇an Pb-Ag deposit is closely related to the alkali-rich porphyry and tectonic activity. This work has carried out the large-scale geo- logical mapping of the 2105m level in the deep deposit,and established geologic sections of number 2 and number 5 veins to analyze lithology-fauh ore- controlling characters. Then it summarized the mineralization law and put forward prospecting target areas in the future. Research suggests that lead miner- alization is mainly distributed along the NE-trending faults and intersection of faults in different directions,in the hanging wall of NE dikes,and cryptoex- plosive breccia edges. The early NNW anticline and NW shear and shear-tensile faults limited the space of Pb-Ag deposit. The NE-directed tensional space formed by later NE-SW principal stress provided channels for volcanic eruption and ore liquid rising, determining the main ore forming structure. The spatial location and occurrence of syenite porphyry dikes and faults are of consistent temporal and spatial relations as well as genetic associations of struc- ture,controlling dike and mineralization contacts. By summarizing the lithology-fault ore-controlling characters and lead mineralization rules,this work sug- gested four targets for ore search toward the deep in this area.

关 键 词：铅银矿床 富碱斑岩 控矿特征 找矿预测 云南姚安 

分 类 号：P618.4[天文地球—矿床学]