林智炜,吴堑虹,奚小双,夏艳菊,刘飚,蒋江波.华北板块北缘中段姚五沟岩体锆石U-Pb定年、地球化学特征及其与区域构造演化的关系[J].地质找矿论丛,2019,34(1):104-116
华北板块北缘中段姚五沟岩体锆石U-Pb定年、地球化学特征及其与区域构造演化的关系
Zircon U-Pb dating and geochemical characteristics of the Yaowugou granite in the middle section of northern margin of the north China plate and its implications to regional tectonic evolution
投稿时间:2018-03-15  修订日期:2018-10-26
DOI:10.6053/j.issn.1001-1412.2019.01.015
中文关键词:  花岗斑岩  LA-ICP-MS锆石U-Pb定年  地球化学特征  构造演化  华北板块北缘中段  内蒙古
英文关键词:granite porphyry  LA-ICP-MS zircon U-Pb dating  geochemical characteristics  geotectonic evolution  the middle section of northern margin of the north China plate  Inner Mongolia
基金项目:中南大学自主探索创新项目(编号:2018zzts068)、丰泰矿业有限公司项目(编号:2011021H001)联合资助。
作者单位
林智炜 中南大学有色金属成矿预测与地质环境监测教育部重点实验室, 长沙 410083
中南大学地球科学与信息物理学院, 长沙 410083 
吴堑虹 中南大学有色金属成矿预测与地质环境监测教育部重点实验室, 长沙 410083
中南大学地球科学与信息物理学院, 长沙 410083 
奚小双 中南大学有色金属成矿预测与地质环境监测教育部重点实验室, 长沙 410083
中南大学地球科学与信息物理学院, 长沙 410083 
夏艳菊 中南大学有色金属成矿预测与地质环境监测教育部重点实验室, 长沙 410083
中南大学地球科学与信息物理学院, 长沙 410083 
刘飚 中南大学有色金属成矿预测与地质环境监测教育部重点实验室, 长沙 410083
中南大学地球科学与信息物理学院, 长沙 410083 
蒋江波 中南大学有色金属成矿预测与地质环境监测教育部重点实验室, 长沙 410083
中南大学地球科学与信息物理学院, 长沙 410083 
摘要点击次数: 75
全文下载次数: 113
中文摘要:
      内蒙古太仆寺旗地区的姚五沟岩体位于华北板块北缘中段,主要岩石类型为花岗斑岩。岩体LA-ICP-MS锆石U-Pb测年结果为141.6 Ma±1.3 Ma(MSWD=0.78),形成于晚侏罗世。岩石化学特征显示岩体具高硅富碱的特征,A/CNK=0.93~1.07,为准铝质-弱过铝质,属高钾钙碱性系列。稀土配分模式呈右倾"V"字型,Eu负异常较显著(δEu=0.30~0.43),轻重稀土分异明显(w(La)N/w(Yb)N=34.04~48.59)。微量元素表现出富集Rb、Th、K等大离子亲石元素,亏损Ba、Sr和Nb、Ta、Ti、P等高场强元素,具有较高的10000×w(Ga)/w(Al)值(2.85~2.92)和w(Zr+Nb+Ce+Y)值(537.80×10-6~584.10×10-6);表明其属A型花岗岩,由下地壳部分熔融而来,并伴随少量幔源组分参与,形成于非造山伸展环境。与研究区内的后淖S型花岗岩(255.8 Ma±1.6 Ma,晚二叠世)和白旗A型花岗岩(134.6 Ma±1.1 Ma,晚侏罗世)的地球化学特征对比,发现由晚二叠世到晚侏罗世,岩浆源区由上地壳的泥质岩部分熔融转换为下地壳部分熔融,并伴随少量幔源组分参与,其大地构造背景由陆-陆碰撞环境转换为非造山伸展环境。
英文摘要:
      The Yaowugou granite in Taibus Bannner of Inner Mongolia is located in the middle section of northern margin of the North China plate mainly consisting of granite porphyry. LA-ICP-MS zircon U-Pb dating is 141.6 Ma±1.3 Ma(MSWD=0.78), showing Late Jurassic intrusives. The geochemistry of this rock is characterized by high concentrations of silica and alkali,A/CNK=0.93~1.07, belongs metaluminous to weakly peraluminous and high-K calc-alkaline to shoshonite granite. The REE distribution patterns is characterized by obvious negative anomalies (δEu=0.30~0.43) and exhibits right-dipping "V" patterns with LREE enrichment(w(La)N/w(Yb)N=34.04~48.59). In addition, the granite is riched in Rb, Th, K and other large ion lithophile elements (LILE), while Ba, Sr and Nb, Ta, P, Ti and other high field strength elements (HESE) are relatively depleted and it has high 10000×w(Ga)/w(Al)(2.85~2.92)and w(Zr+Nb+Ce+Y)(537.80×10-6~584.10×10-6)ratio values, showing the features of A-type granite and it is formed in the non-orogenic extensional tectonic setting. Compared with the geochemical characteristics of Late Permain Hounao S-type granite (255.8 Ma±1.6 Ma) and Late Jurassic Baiqi A-type granite (134.6 Ma±1.1 Ma), it is suggested that the granite formed by partial melting of argillaceous rock in the upper crust transformed into the lower crust with a few mantle-derived composition from Late Permain to Late Jurassic, while the tectonic setting is transformed from the continental collison tectonic setting into the non-orogenic extensional tectonic setting.
查看全文  查看/发表评论  下载PDF阅读器
关闭