广西龙塘—东山铅锌矿床地质特征及矿床成因探讨

Study of Geological Characteristics and Genesis of the Longtang-dongshan Lead-zinc Deposit,Guangxi Province

广西龙塘-东山铅锌矿是位于桂东北地区,海洋山北东向铅锌成矿带,铅锌矿床产于奥陶系与泥盆系不整合面之下,矿床成因独特,形成条件复杂.区内的下奥陶统黄隘组(O1h)和下泥盆统莲花山组(D1l)是主要含矿地层;矿脉产于张扭性正断层(断裂)中,断裂走向为北东东,构成的多条矿脉带呈平行状;成矿物质来源于深部岩浆和基底地层.龙塘-东山铅锌矿矿床矿体呈脉状,受构造控制分布于燕山期张扭性断裂带,矿石构造为块状、浸染状、角砾状构造,结构为粗到细晶结构,矿石矿物为方铅矿、闪锌矿、黄铁矿和微量黄铜矿,矿床成因类型为以岩浆热液为主的中温热液断裂充填交代型脉状铅锌矿床.龙塘-东山地区是寻找中型甚至大型铅锌矿床有利地段.

Guangxi Longtang-dongshan Lead-zinc Deposit is located in the Haiyang Shan NE-trending Lead-zinc metallogenic belt in the northeast area of Guangxi.The lead-zinc deposits occur under the surface of unconformity between the Ordovician and Devonian.The genesis of the deposit is unique and the forming conditions are complex.In Longtangdongshan Lead-zinc Deposit,the principal producing formation are the Lower Ordovician Huang Yi(O1h)and Lower Devonian Lian Hua Shan(D1l);the vein occurs in the tenso-shear normal fault(fracture)and the strike of the fault is NEE,which forms a series of parallel vein belts;the ore-forming materials are derived from the deep-seated magmas and basement strata.And the ore bodies of the Longtang-dongshan Lead-zinc deposits are vein-shaped and distributed in the tenso-shear fault zone of the Yan Mountains period controlled by structures.The ore structures are lumpy,dissemination type,breccia from coarse to fine grain.The ore minerals are galena,sphalerite,pyrite and trace chalcopyrite.The genesis type of the deposit is mesothermal hydrothermal fracture-filling metasomatic vein type lead-zinc deposit dominated by magmatic hydrothermal fluid.The Longtang-dongshan area is a favorable area for searching for medium-sized or even large-scale lead-zinc deposits.