滇东北铅锌矿集区昭通铅锌矿床成因的成矿流体证据

云南昭通铅锌矿床是铅锌多金属矿集区的典型代表之一。该矿床严格受NE向毛坪冲断褶皱构造控制,矿体分布于毛坪逆断层上盘的猫猫山倒转背斜西翼层间断裂带中,呈大脉状陡倾斜产出,其延深远远大于走向延长。主要矿石矿物由闪锌矿、方铅矿、黄铁矿组成,脉石矿物主要为铁白云石、方解石、石英和重晶石。本文针对成矿流体研究的薄弱环节,进行了闪锌矿、脉石矿物(方解石、石英)流体包裹体成分研究,研究认为流体包裹体类型主要呈纯液相和液相,成矿热液属Na+-K+-Ca2+-Cl--F-型,与典型MVT矿床存在明显差异,为深化"会泽型"铅锌矿床"构造–流体‘贯入’成矿"模型提供了重要证据,而且该研究无疑对矿床深部及外围找矿具有指导意义。

Ore-forming fluid evidence of Zhaotong Zn-Pb deposit genesis in the Zn-Pb deposit concentrated district of northeast Yunnan

The Zhaotong Zn-Pb deposit is an important representative of the rich Ge-Ag-bearing Zn-Pb poly-metallic deposits in concentrated district of northeast Yunnan.This deposit were controlled by NE-extending Maoping thrust belt-and-fold structure.The ore bodies were distributed inverted Maomaoshan fold of the west wing of interstratified fault belts on the Maoping reverse fault.It is characterized by high nervation and steeply dipping of the ore,and deep extension of ore bodies farther than the run of the ore vein.The maj or ore minerals are sphalerite,galena and pyrite,and the maj or gangue minerals are ankerite,calcite,quartz and barite.For the weak links of ore-forming fluid study,and ore-forming fluid inclusions compositions of sphalerite,gangue minerals （calcite,quartz）were studied.We hold that the inclusions include pure-liquid and liquid,and the ore-forming hydrothermal one is belonged to the Na＋-K＋-Ca2＋-Cl--F- type.It is clearly distinguished within MVT Zn-Pb deposits.The study provides evidence for＆quot;structural fluid penetration min-eralization＆quot;model of Zn-Pb deposit type-Huize type （HZT）and it is more important for the prospecting work around the deep and outside places near the ore deposts.