甘肃马坞金矿床地质特征及找矿前景探讨

摘要

Mawu gold deposit located in eastern part of Min-Li gold metallogenic belt,approximately 5~7 km away from the Zhongchuan rock,is a medium-sized micro-disseminated gold deposit found in recently years.In this study,through analyzing and systemizing great amount of raw materials obtained during the process of geological exploration,we summarized the deposit geology,physical and chemical characteristics as well.The main orebodies occurred in limestone and phyllite of Hejiadian Group at Devonian with the NWW trending,and the secondary fracture with the NWW trending was the main ore-controlling factors.Meanwhile,the hydrothermal alteration presented primarily for the pyritization,sericitization,silicification and carbonatization.Output of the ore was mainly influenced by three factors,lithology,structure and magmatic rock.Compared with wall rock,it displayed high polarization characteristics of low resistance.Combination feature of the Au element mainly exhibited appearance of Au,As and Sb.On this basis,the seven and eight vein in northern mine were believed to be a large potential in terms of body extended or extension after analysis.Additionally,there was parallel vein body(blind ore body)located at upper and lower plate of the known veins,which demonstrated that better mining ore prospects in northern part of the mine.%马坞金矿分布于岷（县）—礼（县）金成矿带的东部，距中川岩体5~7 km，是近年来发现的一个中型微细浸染型金矿床。通过对地质勘查过程中获得的大量原始资料进行整理和分析，总结了马坞金矿床地质、地球物理和地球化学特征。矿（化）体主要赋存于中泥盆统何家店组灰岩、千枚岩内，呈 NWW 向展布，NWW 向次级断裂是矿区主要的控矿因素，热液蚀变主要有黄铁矿化、绢云母化、硅化和碳酸盐化。矿（化）体产出受岩性、构造及岩浆岩三重因素控制，其较围岩具低阻高极化的特征，Au 元素组合特征以 Au、As 和 Sb 为主。综合分析认为矿区北部1号、7号和8号脉体在延长或延深仍有较大找矿潜力，且在已知脉体上、下盘有平行脉体（盲矿体）存在，矿区北部找矿前景良好。