陕西池沟斑岩型铜矿床含矿岩体地球化学特征、成岩成矿时代及其意义  

Geochemistry and rock_forming and ore_forming epochs of Chigou Cu porphyry deposit in Shaanxi Province, and their implications

作　　者：任涛 王瑞廷 谢桂青[3] 李剑斌 代军治 郭延辉 党勘峰 武晓琴 

机构地区：[1]西北有色地质勘查局七一三总队,陕西商洛726000 [2]西北有色地质勘查局地质勘查院,陕西西安710054 [3]中国地质科学院矿产资源研究所,北京100037

出　　处：《矿床地质》2014年第4期807-820,共14页Mineral Deposits

基　　金："十二五"国家科技支撑计划课题(2011BAB04B05);公益性行业科研专项(201111007_3)项目联合资助

摘　　要：池沟铜钼多金属矿床是近年来在秦岭造山带发现的一处斑岩型矿床.文章对该矿床的成矿岩体进行了岩相学、岩石地球化学分析,并测试了矿石中辉钼矿的Re-Os年龄.结果表明：金属硫化物呈星散浸染状、细脉浸染状分布于池沟石英闪长岩中;池沟中酸性岩体属于高钾钙碱性系列,具准铝质-过铝质性质,微量元素分析结果显示其为碰撞后花岗岩;辉钼矿的Re-Os年龄为148 Ma.池沟区内岩体LA-ICP-MS锆石U-Pb年龄为140～148 Ma,与矿石辉钼矿的Re-Os年龄一致,均形成于侏罗纪晚期.结合岩体产状、含矿性判别分析,认为池沟中酸性岩体的形成和矿化发生在侏罗纪—白垩纪挤压-伸展转变期,对应的地球动力学背景为华北板块与扬子板块碰撞造山后的陆内造山和伸展过程.The Chigou copper-molybdenum polyrnetaHic deposit is a porphyry deposit in the Qinling orogenic belt. The ores show disseminated and fine-grained disseminated structure in Chigou quartz diorite. Geochemical analyses show that the intermediate-acid intrusive body of Chigou belongs to high-K calc-alkaline series, with aluminum- peraluminous characteristics. Trace elements features show the similarity to post-collision type granite. The dat- ing by LA-ICP-MS of zircons and Re-Os of molybdenite indicates that the intermediate-acid intrusive body of Chigou have ages from 140 to 148 Ma, whereas the age of molybdenite obtained by Re-Os method is 148Ma. The ages of the intrusive body and its mineralization are consistent with each other, suggesting that they were both produced in the late Jurassic period. Combining the mode of formation of the intrusive body with its orebearing potential, the authors hold that the intrusive body was produced and mineralized in the period of extru- sion-stretching transformation during Jurassic to Cretaceous time. In addition, its geodynamics setting corre- sponded to the process of intra-continent orogeny and extension during the collision between North China plate and Yangtze plate.

关 键 词：地质学 中酸性岩体 地球化学特征 同位素年代 成矿背景 山阳池沟 

分 类 号：P618.41[天文地球—矿床学]