四川广元太阳坪金矿床地质特征及成因研究

发布时间：2018-01-29 14:07

  本文关键词： 金矿床 地质特征 流体包裹体 矿床成因 太阳坪　出处：《西南科技大学》2015年硕士论文　论文类型：学位论文

【摘要】：太阳坪金矿床位于四川省广元市,大地构造背景处于扬子地台与摩天岭褶皱带中间的茂县群地体,属于阳平关断裂带金矿成矿系列。矿区出露地层以志留系黄坪组为主,为主要容矿围岩;丁家林-太阳坪韧-脆性剪切断裂控制了金矿床的分布、形态和产状。该矿区目前已圈定了5个矿体,均为石英脉状矿体,沿走向有尖灭再现的特点,矿体与围岩界线清楚。矿体长245~399m,厚0.68~0.88m,矿体倾向为165°~360°、倾角为53°~82°;矿石金属矿物主要有黄铁矿、闪锌矿、黄铜矿、方铅矿等,脉石矿物主要有石英、绢云母、绿泥石等。矿石结构以自形-半自形粒状、碎裂、环状等结构为主;矿石构造主要有浸染状、条带状以及团块状等。围岩蚀变有硅化、黄铁矿化、绿泥石化、绢云母化等,其中硅化和黄铁矿化与金成矿有密切关系。黄铁矿的δ34S值的范围为5.7~10.2‰,变化较小,说明硫同位素均一化程度高,硫的来源为围岩;石英矿物中氢、氧同位素分析结果表明该矿床成矿流体来源以变质水为主。流体包裹体研究表明,成矿温度主要集中于180~279℃之间,属于中温范围;成矿流体具有低盐度(2.90~8.68 wt%Na Cl)、低密度(0.71~0.97g/cm3)的特征;成矿压力为39.08~95.25Mpa,成矿深度为4.95~8.04km,具有中深成矿特征。矿床的主要控矿因素为地层和构造因素,找矿标志主要有构造、围岩蚀变、化探异常及旧采遗迹等标志。确定其成因类型为中温变质热液脉型金矿床,并建立了该矿床的成矿模式。
[Abstract]:The Niangping gold deposit is located in Guangyuan City Sichuan Province and the tectonic setting is located in the Maoxian Group between the Yangtze platform and the Ferris Ridge fold belt. It belongs to the metallogenic series of gold deposits in the Yangpingguan fault zone. The exposed strata of the mining area are dominated by the Silurian Huangping formation, which is the main host rock. The distribution, morphology and occurrence of the gold deposit have been controlled by the ductile-brittle shear fracture of Dingjialin-Sun Ping. At present, five orebodies have been delineated, all of which are quartz vein orebodies, with the characteristics of pinnacle reappearance along the strike. The boundary between the orebody and the surrounding rock is clear. The orebody is 245m long, 0.68m thick 0.88m, the orebody tends to 165 掳~ 360 掳and the inclination angle is 53 掳~ 82 掳; There are mainly pyrite, sphalerite, chalcopyrite, galena and so on. The gangue minerals are mainly quartz, sericite, chlorite and so on. The ore structures are mainly dyed, banded and lumped, etc. The wall rock is altered by silicification, pyrite, greenstone, sericite and so on. Among them, silicification and pyrite are closely related to gold mineralization. The 未 34S value of pyrite ranges from 5. 710. 2 鈥，

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