投稿时间:2012-01-02
修订日期:2012-11-03
中文摘要:吉山铁矿床是宁芜火山岩盆地中的重要矿床,矿体主要产于辉长闪长玢岩体内。对吉山辉长闪长玢岩体运用SHRIMP锆石U-Pb定年技术进行年龄测试,结果为(130.0±1.0) Ma,代表成岩年龄。结合地质事实与前人研究成果,推测吉山铁矿床的成矿时间约为130 Ma或稍后。年代学研究中出现的年龄值(1885±14) Ma,与扬子克拉通的基底年龄值相吻合,暗示宁芜地区可能存在古元古代基底。吉山辉长闪长玢岩成岩及玢岩型铁矿床成矿作用所对应的地球动力学背景为中生代发生的中国东部岩石圈大规模减薄事件。
中文关键词:地球化学 SHRIMP锆石U-Pb定年 辉长闪长玢岩 宁芜盆地 地球动力学背景
Abstract:The Jishan iron ore deposit is one of the important deposits in Ningwu volcanic basin. Ore bodies occur mainly in the gabbro-diorite porphyrite pluton. SHRIMP zircon U-Pb dating shows that the petrogenetic age of the gabbro-diorite porphyrite pluton is (130.0±1.0) Ma. In combination with geological survey and the previous studies, the authors hold that the metallogenic age of the Jishan iron ore deposit was about 130 Ma or later. The single age (1885±14) Ma in the chronologic research is consistent with the age of the Yangtze craton basement, suggesting that the Early Proterozoic basement may exist in Ningwu basin. The geodynamic setting corresponding to the diorite porphyrite pluton and the porphyrite-type iron deposit in Jishan was the large-scale Mesozoic lithospheric thinning event in eastern China.
keywords:geochemistry SHRIMP zircon U-Pb dating gabbro-diorite porphyrite Ningwu basin geodynamic setting
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中图分类号:P618.31
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基金项目:本文为中国地质调查局资源评价项目(编号: 1212010781014,1212010660404)及中国地质大学地质过程与矿产资源国家重点实验室开放基金课题(编号: MGMR2001-1)资助成果
引用文本:
李锦伟,陈津华,曾键年,陆建培,张燕霞,李小芬,吴亚飞,陆顺富.2012.宁芜盆地吉山铁矿床辉长闪长玢岩SHRIMP锆石U-Pb定年及其地质意义[J].矿床地质,31(6):1227~1236LI JinWei,CHEN JinHua,ZENG JianNian,LU JianPei,ZHANG YanXia,LI XiaoFen,WU YaFei,LU SunFu.2012.SHRIMP zircon U-Pb dating of gabbro-diorite porphyrite in Jishan iron ore deposit of Ningwu basin and its geological significance[J].Mineral Deposits31(6):1227~1236
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