勐糯铅锌矿床岩性分带特征与成因机制OA

Mengnuo lead-zinc deposit is located in the Baoshan-Zhenkang Pb,Zn,Hg and rare metal metallogenic belt,and is an important lead-zinc polymetallic ore-producing area.Through large-scale tunnel mapping of typical cross-cuts in the deep part of the mining area and microscopic identification and analysis,combined with a comparison with typical SEDEX deposit characteristics,the lithologic association zoning and genesis of the deposit were systematically studied.The research results indicate that the lithologic associations can be categorized into three groups:overlying strata,ore-bearing strata,and underlying strata.8 distinct lithologic types were further recognized.Among these,the grayish-black units represent reductive lithologic contacts,the purplish-red units represent oxidative contacts,and the light grayish-green,light yellowish-white,and grayish-white units represent transitional contacts.It is suggested that the deposit is a strongly reworked SEDEX-type deposit.Mineralization in the shallow part is dominated by sedimentation,while superimposed reworking may occur at depth.The degree of metamorphism and alteration intensifies downwards,indicating significant prospecting potential for lead-zinc polymetallic ores in the deep part.