云南省老许寨铜及多金属矿床成因及找矿潜力分析

Prospecting potential and genesis of the Cu-polymetal deposit in Laoxuzhai Country,Yunnan Province

老许寨铜及多金属床位于云南"三江"成矿带南段,形成于岛弧环境中,是一处较为典型的火山喷流—沉积型矿床。矿床形成主要受海相火山裂陷盆地控制,盆地中发育较为典型的"双峰式"火山岩。矿区成矿条件优越,含矿层位为上石炭统龙洞河组上段(C3l2)中的第二段,含矿岩性主要为角砾状流纹岩、沉凝灰岩及部分硅质岩。矿(化)体主要由位于上部的块状硫化物矿体及下部的细脉浸染状矿体组成,共同构成典型的"双层结构"。本文通过研究区域地质背景和成矿地质特征,结合矿区演化特点及矿床成因,对矿区找矿潜力进行分析,为本矿区进一步深部找矿提供理论依据。

The Laoxuzhai Cu-polymetal deposit is located in the Sanjiang metallogenic belt of Yunnan Province, which has a volcanic exhalation-sedimentary deposit. The ore bodies are controlled by marine volcanic rift basin,bimodal volcanic suites are extensively developed in the basin. The ore-bearing stratum is the second Member of the upper Carboniferous Longdonghe Formation（C3l 2）, and the ore-bearing lithology include brecciated rhyolite, sedimentary tuff and silicolite. The ore（mineralized） bodies were composed of the upper massive sulfide ore bodies and lower veinlet-disseminated ore bodies, which has a typical ＂two-layer structure＂. The paper summarized the metallogenic characteristics and prospecting indicators, and analyzed the regional prospecting potential which provide good basis for further exploration in the deep.