滇西镇康水头山Pb-Zn矿床成矿流体及矿质来源探讨——H、O、S、Pb同位素地球化学证据
发布时间：2018-07-21 16:17
【摘要】：滇西镇康水头山Pb-Zn矿床是保山地块镇康Pb-Zn-Fe-Cu多金属矿集区内又一重要找矿成果。矿体呈似层状、透镜状产于上寒武统保山组大理岩化灰岩中,呈NEE向顺层产出,矿石矿物主要为闪锌矿和方铅矿,偶见黄铜矿和黄铁矿等;脉石矿物主要有白云石、绿泥石、方解石、石英和绢云母等。本文基于对矿床地质特征的详细研究,结合矿床H、O、S、Pb同位素组成,对其成矿流体和矿质来源进行了探讨,同时与毗邻的芦子园超大型Pb-Zn-Fe-Cu多金属矿床进行了对比。研究表明:该矿床石英的δD值介于-101.1‰~-93.3‰之间,均值为-96.85‰(n=4),δ~(18)O_(H_2O)值为3.37‰~3.77‰之间,均值为3.57‰(n=4),表明成矿流体早期以原生岩浆水为主,有大气降水的混入。矿床金属硫化物的δ~(34)S值均为正值,介于4.1‰~12.2‰,均值为8.23‰(n=10),与旁侧的芦子园矿床δ~(34)S值(8.9‰~12‰)较为接近。该矿床可划分出三个成矿阶段,阶段Ⅱ为以闪锌矿和方铅矿为主的主要成矿阶段(δ~(34)S主要集中在4.1‰~6.2‰之间),其δ~(34)S均值可近似代表成矿热液中的δ~(34)S∑S值,即δ~(34)S∑S≈δ~(34)S均值=6.56‰(n=7),闪锌矿和方铅矿δ~(34)S值有部分重叠,但总体上具有δ~(34)S闪锌矿δ~(34)S方铅矿以及不同颜色闪锌矿之间δ~(34)S深棕色闪锌矿δ~(34)S棕褐色闪锌矿δ~(34)S浅棕色闪锌矿的分布特征,暗示硫同位素在硫化物间的分馏达到平衡,表明S同位素组成较为稳定,显示水头山矿床具有深部壳源岩浆成因的特征。矿床金属硫化物的Pb同位素分析显示,Pb同位素组成非常集中(~(206)Pb/~(204)Pb=18.3408~18.4483,均值为18.3815,~(207)Pb/~(204)Pb=15.8337~15.9440,均值为15.8745,~(208)Pb/~(204)Pb=38.8224~39.4391,均值为38.9941,n=10),投点主要分布在上地壳演化线上方,表明其Pb主要来自于以岩浆作用为主的上地壳物质。本文认为矿区深部壳源岩浆热液是水头山矿床最重要的成矿流体与矿质来源,流体的混合作用是矿床金属元素沉淀和富集的重要机制,矿床具有低温、后生成矿特征,推测矿床的形成与燕山晚期的岩浆热液作用有关。
[Abstract]:The Pb-Zn deposit of Zhenkang Shuitoushan in western Yunnan is another important prospecting result in Zhenkang Pb-Zn-Fe-Cu polymetallic ore concentration area of Baoshan block. The orebody is layered and lenticular in marble limestone of the Baoshan formation of the Upper Cambrian, producing in nee direction. The ore minerals are mainly sphalerite and galena, occasionally chalcopyrite and pyrite, etc. The main gangue minerals are dolomite, chlorite, etc. Calcite, quartz, sericite, etc. Based on the detailed study of the geological characteristics of the deposit and the isotopic composition of the ore deposit, the ore-forming fluid and the source of the ore-forming material are discussed and compared with the adjacent superlarge Pb-Zn-Fe-Cu polymetallic deposit in Luziyuan. The results show that the 未 D value of quartz is between -101.1 鈥，
本文编号：2136080
[Abstract]:The Pb-Zn deposit of Zhenkang Shuitoushan in western Yunnan is another important prospecting result in Zhenkang Pb-Zn-Fe-Cu polymetallic ore concentration area of Baoshan block. The orebody is layered and lenticular in marble limestone of the Baoshan formation of the Upper Cambrian, producing in nee direction. The ore minerals are mainly sphalerite and galena, occasionally chalcopyrite and pyrite, etc. The main gangue minerals are dolomite, chlorite, etc. Calcite, quartz, sericite, etc. Based on the detailed study of the geological characteristics of the deposit and the isotopic composition of the ore deposit, the ore-forming fluid and the source of the ore-forming material are discussed and compared with the adjacent superlarge Pb-Zn-Fe-Cu polymetallic deposit in Luziyuan. The results show that the 未 D value of quartz is between -101.1 鈥，
本文编号：2136080
本文链接：https://www.wllwen.com/kejilunwen/kuangye/2136080.html
