滇南兰坪南厂铅锌矿矿床成因及成矿作用

南厂铅锌矿位于兰坪—思茅中生代坳陷北端，构造格局复杂，成矿条件优越。通过对矿床进行野外地质调查，对成矿地质背景、矿床地质特征、成矿机制和矿床成因进行了分析，发现南厂铅锌矿体主要呈透镜状赋存于第三系云龙组（Eyb）及下白垩统景星组（K1j1）地层中，与围岩接触部位发育微弱褪色蚀变，云龙组下段（Eya）是矿体底板有效的“屏蔽层”；区内发育原生砂岩型矿石、灰岩型矿石和氧化矿石，沉积构造特征明显，局部具有热液、变质作用改造特征；矿区地层、构造是矿床形成的重要因素，断裂构造是主要的容矿、导矿构造，高盐度热卤水沿导矿构造循环至有利层位、构造部位富集成矿，综合分析认为南厂矿床属热卤水为主的多成因层控型铅锌矿床。

Ore Genesis and Metallogenesis of Nanchang Lead zinc Deposit in Southern Yunnan#br#

Nanchang Lead zinc Deposit is located in northern section of Mesozoic Simao Lanping depression,which has complicated tectonic framework and superior metallogenic condition.Based on the field geological survey of Nanchang lead zinc Mine and the analysis of its metallogenic geological background,geological characteristics,metallogenic mechanism and ore genesis,it is found that the ore bodies are mainly occurred as lenticular in Yunlong Formation of Tertiary (Eyb) and Jingxing Formation of Lower Cretaceous (K1j1),and the Lower Yunlong Formation (Eya) is an efficient shielding layer in deposit.Besides that,the faint fade alteration occur at contact position between strata and surrounding rock.The Nanchang lead zinc deposit developed sandstone type ore,limestone type ore and oxidized ore,which has obvious sedimentary structure,and the ore has hydrothermal and metamorphic alteration characteristics in some areas.The strata and tectonic in mining area are proved to be the main factors in the formation of the deposit.The ore bearing structure and ore transmitting structure are faults.The high salinity hot brine has enriched in favorable stratigraphic horizon and tectonic,which migrated along the ore transmitting structure.The results show that Nanchang deposit is a multiple genesis strata bound type lead zinc deposit which is related to hot brine.