鄂东北花桥金矿构造蚀变特征及成矿规律浅析

Structural Alteration Characteristics and Metallogenic Regularity of Huaqiao Gold Deposit in Northeast Hubei Province

花桥金矿是唯一产于鄂东北梅川岩体南缘外接带的构造蚀变岩型金矿,通过分析其构造蚀变特征和控矿因素,重新认识其矿化富集规律,可为梅川岩体南缘的找矿预测提供依据。研究表明,花桥金矿的矿体严格受断裂破碎(蚀变)带控制,NE向断裂破碎带为主要控矿构造,至少经历了3期构造—热液叠加改造,中期形成由黄铁绢英岩、黄铁绢英岩质碎裂岩等组成的矿化蚀变碎裂岩带,赋存了大小不等的矿体,呈现“大带套小带、小带产矿体”的矿化特征。初步分析认为花桥金矿可能形成于早白垩世,梅川岩体提供了成矿热液、成矿物质及热能,郯庐断裂带及其次级剪切带为导矿构造,矿区浅表层次脆性断裂及其裂隙为容矿构造,赋矿围岩主要为构造蚀变岩。建议进一步加强梅川岩体与金多金属矿成矿关系的研究,开展梅川岩体南缘内外接触带深部找矿预测。

The Huaqiao gold deposit is the only structural altered rock type gold deposit in the outer zone of the southern margin of the Meichuan rock mass in northeastern Hubei Province.By analyzing its structural alteration characteristics and ore-controlling factors,the mineralization enrichment regularity is re-recognized,it may provide a basis for the prospecting prediction of the inner and outer contact zone and deep part of the Meichuan rock mass.The study shows that the ore body of Huaqiao gold deposit is strictly controlled by the fracture(alteration)zone.The NE-trending fracture zone is the main ore-controlling structure.It has experienced at least three stages of tectonic-hydrothermal superposition transformation.In the middle stage,the mineralized altered cataclastic rock belt composed of pyrite sericite quartzite and pyrite sericite quartzite rock is formed,and the ore bodies of different sizes are hosted,showing the mineralization characteristics of“large belt sets small belt and small belt produces ore body”.The preliminary analysis shows that the Huaqiao gold deposit may be formed in the early Cretaceous.The Meichuan rock mass provides ore-forming hydrothermal fluid,ore-forming materials and thermal energy.The Tanlu fault zone and its secondary shear zone are ore-conducting structures.The shallow brittle fractures and their fissures in the mining area are ore-bearing structures.The ore-bearing surrounding rock is mainly structural altered rock.It is suggested to further strengthen the research on the relationship between Meichuan rock mass and gold polymetallic mineralization,and carry out the deep prospecting prediction of the inner and outer contact zone in the southern margin of the Meichuan rock mass.