滇西老厂银铅锌多金属矿床Ⅳ(S)号矿体地质特征及矿床成因探讨

Geological Characteristics of Ⅳ(S) Ore Body and Mineralization Mechanism of Laochang Ag-Pb-Zn Polymetallic Deposit,Western Yunnan

滇西老厂大型银铅锌多金属矿床位于"三江"成矿带南段昌宁-孟连裂谷盆地内,是最重要的大型矿床之一。虽然前人对该矿床做了大量研究工作,取得了许多研究成果,但对成矿机理、成矿规律和矿床成因的认识存在较大分歧。从以往的工作中不难发现,前人对Ⅳ矿体群的研究较为薄弱,而Ⅳ矿体群正是产于主控矿断裂中贯通矿区深部及浅部的矿体群,因此对该矿体群的研究是探讨矿床成因的又一切入点。通过对矿区北西部新发现的Ⅳ(S)矿体进行基础地质研究,同时综合以往与老厂矿床相关的地质资料,认为老厂矿床应属多复成因,其成因主要与海西晚期的岩浆热液及燕山晚期—喜山早期隐伏花岗斑岩体有关。

Laochang large-scale Ag-Pb-Zn polymetallic deposit in western Yunnan is located in the basin of the Changning-Menglian rift which lies in the southern part of the Three-River metallogenic belt.As one of the most important deposits,previous studies of the deposit have been done and a lot of researches resuct are obained,but the research of mineralization chronology is extremely weak.From the previous work,it is easy to find out that reaserch on Ⅳ ore clusters is rare.But Ⅳ ore clusters is the ore body through the mining area deep to shallow.So Ⅳ ore clusters is a key to study on mineralization mechanism.Ⅳ ore body is chosen to carry out basic geology studies,Ⅳ ore body is newly discovered in NW of Laochang Mining area and past data are summarized.It is suggested that Laochang deposits belong to multi-complex causes,and it is mainly related to magmatic hydrothermal in late Hercynian period and concealed granite porphyry from late Yanshanian period to early Hymalayan period.