花垣李梅铅锌矿集区地质特征及矿床成因探讨

Discussion on the Geological Features and Genesis of the Limei Pb-Zn Ore Concentration Belt in North-western Hunan Province

李梅铅锌矿集区为湘西北最具找矿潜力的铅锌成矿区,赋存于寒武系下统清虚洞组厚大的碳酸盐岩中。矿化带延伸与藻礁浅滩相带一致。矿体具多层性,呈缓倾斜以整合层带状产出。矿石以锌为主铅锌共生,具有一定分带现象。矿石为微晶状、细晶状及胶状等结构。成矿物质主要来源于藻类及碳酸盐泥对Pb2+、Zn2+离子的吸取。稳定同位素资料表明,本区铅具有以幔源为主,壳幔混合的特点,硫源主要来自碳酸盐岩系的硫酸盐。矿床成因属于沉积成岩矿床类型,兼有成岩期后矿床性质。找矿应主要沿藻礁浅滩相东延地带进行,结合构造-地球化学分析,以探查隐伏矿床为主。

Limei Pb-Zn deposit shows great potential exploration in the north-western Hunan area. It is located in the carbonate rock of the Qingxudong Formation of the Lower Cambrian, and mineralization extending along the algae reef bank facies belt. The ore-bodies have muhilayer with mild dip, conformable bedding. The mineralization is mainly Zn coexisting Pb element, exhibiting zoning, microcrystal, finecrystal and gel-like texture. The ore-forming materials come from Pb2＋ and Zn2＋ ions absorbed by the algae and carbonated mud. The stable isotope data indicate that the Pb from mantle in the crust. The S is mainly from the sulphate of the carbonate rock series. Therefore the mineralization type characterized by sedimentation-diagenesis deposit and post-diagenesis type. The further prospecting should focus on the eastern extending part of the algae reef bank facies belt to search for the concealed deposit.