藏南扎西康矿集区姐纳各普金矿床地质与流体包裹体特征

发布时间：2018-05-02 23:38

  本文选题：造山型金矿 + 矿床地质　； 参考：《矿物学报》2017年06期

【摘要】：姐纳各普金矿床位于藏南金锑成矿带东段,是近年来在扎西康矿集区内新发现的岩金矿床。矿床产于蚀变辉绿岩中,矿体受北西-南东向韧脆性断裂及层间破碎带控制。矿石类型有蚀变岩型和石英脉型2种,呈网脉状、角砾状及定向构造,土状、结晶、碎裂、糜棱结构;矿石中金属矿物主要为黄铁矿、毒砂、辉锑矿、方铅矿、闪锌矿及自然金,脉石矿物以石英、绢云母及绿泥石为主;围岩蚀变主要为黄铁绢英岩化和绿泥石化;据脉体穿插和矿物共生组合,将原生热液成矿期分为石英-黄铁矿(早)、石英-金-贱金属硫化物(中)和石英-碳酸盐矿物(晚)3个阶段。对矿石中石英流体包裹体研究显示,矿床主成矿阶段(中)流体包裹体主要为由纯CO_2、水溶液和富CO_2-水溶液流体包裹体3种所构成的非均一捕获流体包裹体组合(F.I.A.),均一温度为221.7~279.4℃,盐度为1.57%~6.74%,流体密度为0.58~0.88 g/cm~3,属中低温、低盐度、低密度、富CO_2的H_2O-Na Cl-CO_2±CH_4±N_2体系。主成矿阶段内见均一温度相近的不同类型包裹体和同类型具不同气液比的包裹体共存于同一视域,显示成矿流体的不混溶性,成矿温度为218.6~280.4℃,成矿压力为73~93 MPa。据成矿压力估算得成矿深度为5.8~7.9 km,成矿时的地温梯度为35~45℃/km。矿床地质特征及成矿流体性质表明,姐纳各普金矿床为与岩浆或岩浆热液活动有关的造山型金矿床,成矿与中新世印度—欧亚大陆碰撞挤压向伸展作用的转换有关。
[Abstract]:The Sinagopu gold deposit, located in the eastern section of the gold-antimony metallogenic belt in southern Tibet, is a newly discovered rock gold deposit in the Zaxikang ore concentration area in recent years. The deposit occurs in altered diabase and the orebody is controlled by NW-SE ductile brittle fracture and interlayer fracture zone. There are two types of ore types: altered rock type and quartz vein type, with reticular vein, breccia and directional structure, soil shape, crystallization, fragmentation, chyme structure, pyrite, arsenopyrite, stibnite, galena, pyrite, pyrite, pyrite, galena, pyrite, stibnite and galena. Sphalerite and natural gold, gangue minerals are mainly quartz, sericite and chlorite; rock alteration is mainly yellowish sericite and greenstone; according to vein intercalation and mineral symbiotic assemblage, The metallogenic epoch of primary hydrothermal solution is divided into three stages: quartz pyrite (early pyrite) quartz-gold-base metal sulfide (middle) and quartz-carbonate mineral (late). The study of quartz fluid inclusions in ores shows that, In the main metallogenic stage (middle) of the deposit, the fluid inclusions are mainly composed of three kinds of fluid inclusions consisting of pure COD 2, aqueous solution and CO2- rich aqueous fluid inclusions. The homogeneous temperature is 221.7N 279.4 鈩，

本文编号：1835966