西秦岭李子园碎石子斑岩型金矿床地质特征及成矿时代

来源期刊：黄金2011年第7期

论文作者：刘云华 刘怀礼 黄绍峰 高洪兴 张永强 李志国 郑绪忠

文章页码：12 - 18

关键词：斑岩型金矿床； 地质特征； 成矿时代； 碎石子金矿床； 李子园； 西秦岭

Key words：porphyry gold deposit； geological feature； metallogenic epoch； Suishizi gold deposit； Liziyuan； west Qinling mountain

摘    要：西秦岭李子园碎石子金矿床受闪长玢岩脉和断裂破碎带的双重控制,矿体上部主要产于闪长玢岩脉附近的断裂破碎带中,矿体下部产于闪长玢岩脉内部;矿石中金属矿物主要为黄铁矿、黄铜矿、方铅矿;黄铁矿为主要的金、银的载体矿物,矿石以细脉—浸染状、细脉—网脉状构造为主,具有斑岩型矿床的蚀变类型特点。矿区与成矿有关的正长斑岩和闪长玢岩的锆石SHRIMP U-Pb年龄为(213.9±0.7)Ma和(212.2±1.19)Ma,分别代表了正长斑岩与闪长玢岩的成岩年龄,矿化蚀变闪长玢岩中绢云母的K-Ar年龄为(206.82±1.63)Ma,代表了矿床的成矿年龄。研究后认为碎石子金矿床具有斑岩型金矿床的地质特征,为与闪长玢岩有关的斑岩型金矿床,区域及矿区深部具有寻找斑岩型矿床的潜力。

Abstract: Suishizi gold deposit located in west Qinling mountain is controlled by both diorite-porphyrite veins and fault fractured zone.The upper orebody produced in the fractured zone near the diorite-porphyrite veins,while the lower orebody hosted in the diorite veins.Pyrite,chalcopyrite,galena are the main mineral compositions of ore,and pyrite is the main mineral carrier of gold and silver.Small vein-disseminated and small vein-network structures are the main structures of the ore,which indicates the deposit has the alteration characteristics of porphyry type deposits.The ages (213.9±0.7) Ma and (212.2±1.19) Ma of zircon represent the formation ages of syenite porphyry and diorite-porphyrite respectively,whose ages are tested by SHRIMP U-Pb.Sericite in alterated diorite has the K-Ar age of (206.82±1.63) Ma,which represents the deposit formation age.Suishizi gold deposit has the geological features of the porphyry gold deposit,and it is a porphyry-type gold deposit related to diorite-porphyrite.The region and the deep have the potential to find porphyry deposit.