湘东北金鸡金矿床岩体成岩机制
投稿时间:2019-11-20  修订日期:2019-12-23  点此下载全文
引用本文:
DOI:
摘要点击次数: 59
全文下载次数: 0
作者单位E-mail
隗含涛 自然资源部成矿作用与资源评价重点实验室 csuwht@126.com 
邵拥军 有色金属成矿预测与地质环境监测教育部重点实验室  
汪程 有色金属成矿预测与地质环境监测教育部重点实验室  
刘清泉 有色金属成矿预测与地质环境监测教育部重点实验室  
刘忠法 有色金属成矿预测与地质环境监测教育部重点实验室  
陈炳翰 自然资源部成矿作用与资源评价重点实验室  
中文摘要:江南造山带湖南段中早古生代花岗质岩石对于研究早古生代构造演化以及金成矿作用具有重要的意义。位于该区中段的金鸡金矿床钻孔中新发现有两类花岗质岩石,分别为花岗岩和花岗闪长岩。对两类岩体样品进行了锆石LA-ICPMS U-Pb测年,获得的年龄分别为425.2±1.5Ma和430.6±1.5Ma。岩石地球化学数据表明,花岗岩属I型花岗岩,其来源于地壳中变泥质岩石的部分融熔;花岗闪长岩属埃达克岩,其起源于地壳中变砂质岩石的部分融熔。Sr-Nd同位素分析显示,金鸡花岗闪长岩具有较高的(87Sr/86Sr)i(0.722369~0.722488)、较低的(143Nd/144Nd)i(0.511941~0.511990)以及εNd(t)值较低(-8.2~-7.2),并且金鸡花岗闪长岩的二阶段Nd模式年龄值为1.75~1.84Ga,与江南造山带变质基底的二阶段模式年龄(1.65~2.14 Ga)一致。金鸡金矿床花岗岩和花岗闪长岩的岩石地球化学、年代学以及Sr-Nd同位素特征表明二者是华南早古生代陆内造山事件的产物,岩体成因及地球动力学背景的研究将有助于揭示湘东北地区金矿形成的地球动力学机制。
中文关键词:花岗岩  花岗闪长岩  岩石地球化学  年代学  金鸡金矿床  江南造山带
 
Petrogenesis of the granitoids in the Jinji Au deposit, northeastern Hunan Province, South China
Abstract:The middle-early Paleozoic granitoids in Hunan section of the Jiangnan orogenic belt are of great significance to the study of the early Paleozoic tectonic evolution and gold mineralization. Two types of granitoids, granite and granodiorite, are newly found in the Jinji gold deposit, which is sited in central section of the orogenic belt. Two types of rock samples were dated by zircons La-ICPMS U-Pb technique, and the results show that the granite and granodiorite yield U-Pb zircon ages of 425.2±1.5 Ma and 430.6±1.5 Ma, respectively. The geochemical data show that granite belongs to I-type granite, which comes from partial melting of metapelitic rocks in the crust; granodiorite belongs to adakite, which comes from partial melting of metasandy rocks in the crust. The Sr-Nd isotopic analysis shows that the granodiorite has higher (87Sr/86Sr)i values of 0.72236 and 0.722488, lower (143Nd/144Nd)i values of 0.511941 and 0.511990 and lower εNd(t) values of 8.2 and 7.2, and the two-stage Nd model ages of the granodiorite are 1.75 Ga and 1.84 Ga, which are consistent with the ages of metamorphic basement in the Jiangnan orogenic belt (1.65~2.14 Ga). The lithogeochemistry, geochronology and Sr-Nd isotopic characteristics of granites and granodiorites in the Jinji gold deposit indicate that they are the products of Early Paleozoic intracontinental orogenic events in South China, and the results are useful to open out the geodynamic mechanism for Au mineralization in northeastern Hunan Province.
keywords:Granite  Granodiorite  Lithogeochemistry  geochronology  Jinji Au deposit  Jiangnan orogenic belt
  查看/发表评论  下载PDF阅读器
版权所有 《地球学报》编辑部 Copyright©2008 All Rights Reserved
主管单位:中华人民共和国自然资源部 主办单位:中国地质科学院
地址: 北京市西城区百万庄大街26号,中国地质科学院东楼317室 邮编:100037 电话:010-68327396 E-mail: diqiuxb@126.com
技术支持:北京勤云科技发展有限公司
京ICP备05029128号-6

京公网安备 11010202007616号