• 首页|本刊简介|在线投稿|过刊浏览|高级检索|专家风采|学习园地|期刊论坛|联系我们
桂东南永安岩体锆石U-Pb测年、Hf同位素特征及其地质意义
U-Pb age and Hf isotopic characteristics of zircons from the Yongan granitoid pluton in southeastern Guangxi and their geological implications
投稿时间:2017-07-14  修订日期:2018-09-10
中文关键词:永安岩体  锆石U-Pb测年  地球化学  Hf同位素  广西
英文关键词:Yongan pluton  zircon U-Pb age  geochemistry  zircon Hf isotope  Guangxi
基金项目:中国地质调查局区域地质矿产调查项目(12120113072000)
作者单位
袁永盛 中国人民武装警察部队 黄金第九支队, 海南 海口 571127 
刘胜 中国人民武装警察部队 黄金第九支队, 海南 海口 571127 
南争路 中国人民武装警察部队 黄金第九支队, 海南 海口 571127 
詹华思 中国人民武装警察部队 黄金第九支队, 海南 海口 571127 
摘要点击次数: 42
全文下载次数: 39
中文摘要:
      永安岩体位于钦杭结合带南部,属桂东南十万大山-大容山复式岩体的一部分,其岩石类型为斑状堇青黑云花岗闪长岩。对永安岩体斑状堇青黑云花岗闪长岩进行了LA-ICPMS锆石U-Pb测年,获得其年龄为252.8±3.3 Ma,为晚二叠世花岗岩。对永安岩体花岗岩进行的全岩地球化学分析结果表明,岩石富Al、高K,铝饱和指数A/CNK均大于1.1,标准矿物分子刚玉均大于1%;岩石富集轻稀土元素,亏损重稀土元素,轻重稀土元素分馏明显,稀土元素的球粒陨石标准化配分曲线为轻稀土元素富集的右倾型,具弱负铕异常;岩石富集大离子亲石元素(Rb、Ba、K、Sr),亏损高场强元素(Nb、P、Ti、Ta)和Ba、Sr。花岗岩的锆石εHf(t)=-14~-8,tDM2=2.3~1.8 Ga。通过本文工作,结合前人关于永安岩体矿物学、全岩地球化学、Hf同位素和锆石微量元素的分析资料,认为永安岩体岩石为强过铝质S型壳源花岗岩,地幔组分没有提供成岩物质,但地幔底侵作用为成岩提供了热能,花岗岩形成于后碰撞阶段的拉张环境中。
英文摘要:
      The Yongan granitoid pluton, which is located in the southern Qinhang suture zone, is a part of the Darongshan-Shiwadashan composite pluton in southeastern Guangxi. The pluton is composed of porphyritic cordierite-biotite granodiorite. The results of zircon U-Pb dating indicate that the age of the Yongan pluton is 252.8±3.3 Ma, suggesting Late Permian granites. The geochemical characteristics of the granites of Yongan pluton show that the rocks are rich in Al, K. A/CNK ratios are higher than 1.1. The standard mineral corundum molecules are more than 1%. In addition, the rocks are enriched in LREE, and depleted in HREE, and exhibit obvious fractionation between LREE and HREE. The chondrite-normalized REE patterns show right declining, exhibiting enrichment of LREE and slightly negative Eu anomalies. The granites are enriched in large ion lithophile elements (Rb, Ba, K, Sr) and depleted in high-field strength elements (Nb, P, Ti,Ta) and Ba, Sr. Zircon Hf isotopic compositions of the porphyritic cordierite-biotite granodiorite are mainly characterized by εHf(t) values of -14~-8, and the two-stage model ages of 2.3 to 1.8 Ga. In combination with previous data and an analysis of mineralogy and geochemistry as well as the zircon Hf isotopes and trace elements, it could be concluded that the Yongan pluton is strongly peraluminous S-type granite derived from the crustal source. Though the mantle failed to provide the rock material, the heat for the formation of magma was probably provided by the mantle underplating. The granite was formed in an extensional environment of the post-collision stage.
袁永盛,刘胜,南争路,詹华思,2018,桂东南永安岩体锆石U-Pb测年、Hf同位素特征及其地质意义[J].岩石矿物学杂志,(6):869~883.
查看全文  查看/发表评论  下载PDF阅读器
关闭
您是本站第 4993666位访问者  京ICP备05032737号-8
版权所有:《岩石矿物学杂志》编辑部
主管:中国科学技术协会 主办:中国地质学会岩石学专业委员会 中国地质学会矿物学专业委员会 中国地质科学院地质研究所
技术支持:北京勤云科技发展有限公司

京公网安备 11010202007772号

function PdfOpen(url) { var win="toolbar=no,location=no,directories=no,status=yes,menubar=yes,scrollbars=yes,resizable=yes"; window.open(url,"",win); } function openWin(url,w,h){ var win="toolbar=no,location=no,directories=no,status=no,menubar=no,scrollbars=yes,resizable=no,width=" + w + ",height=" + h; controlWindow=window.open(url,"",win); } &et=EB9300D1CF6A2F43792CA7B34E4CCDCC6DDF5C1C5BBD0E6AAFD18116717008A1B1A5FB76A042435A296D0946F299D3483A8087923AA573E653BC447DF7790990CFE253CD6029AB016D5221FA6AA78F9C62A60FE09DEB564296E86A47AD63683B1038AF15A81F45707BED9E113ABECA8F74F917F07D9FC339C94EDF9D8A1F88DEA9945017BE977E47E06C4FF818A6418D&pcid=E62459D214FD64A3C8082E4ED1ABABED5711027BBBDDD35B&cid=621CF755B1A341E5&jid=25F5F0F8F42BD24D151314EDEA002993&yid=EA357AD73C8E13BC&aid=&vid=&iid=B31275AF3241DB2D&sid=F26986CDF689DBC4&eid=899CC9158FC43EF4&fileno=20180601&flag=1&is_more=0"> var my_pcid="E62459D214FD64A3C8082E4ED1ABABED5711027BBBDDD35B"; var my_cid="621CF755B1A341E5"; var my_jid="25F5F0F8F42BD24D151314EDEA002993"; var my_yid="EA357AD73C8E13BC"; var my_aid="";