贺根山构造带北部晚石炭世构造岩浆岩带年代学及意义

发布时间：2018-02-21 06:01

本文关键词： 兴蒙造山带锆石U-Pb定年构造岩浆岩带晚石炭世　出处：《中国地质大学(北京)》2016年硕士论文　论文类型：学位论文

【摘要】：研究区位于兴蒙造山带二连—贺根山蛇绿岩带北侧,二连—贺根山蛇绿岩带北部地区广泛发育晚古生代构造岩浆岩,通过对晚古生代构造岩浆岩带内的花岗斑岩和中细粒花岗闪长岩进行精准的年代学和地球化学研究,并结合前人晚古生代岩浆岩资料,系统的研究贺根山构造带北部地区晚古生代侵入岩的成因及其大地构造背景,为西伯利亚板块和华北板块的最终闭合时间及其碰撞演化历史提供新的证据。本文研究的贺根山构造带北侵入岩位于达来苏木一带,岩性为中细粒花岗闪长岩和花岗斑岩,运用LA-ICP-MS测年方法对中细粒花岗闪长岩和花岗斑岩进行测年,锆石U-Pb年龄分别为328±2 Ma(MSWD=1.3)和304±2 Ma(MSWD=2.0)。SiO2含量为67.91%~71.98%,Al2O3含量为14.04%~14.85%,TiO2含量为0.32%~0.37%,A/CNK值为0.95~1.03,介于准铝—过铝质花岗岩类之间。结合前人以往的资料表明,在二连—贺根山蛇绿岩带北部地区发育有330 Ma~300 Ma石炭纪的侵入岩以钙碱性—高钾钙碱性系列为主,并在二连—贺根山蛇绿岩带北部地区形成I型花岗质岩浆为主的岩浆岩带,二连浩特—贺根山蛇绿岩带作为晚古生代缝合带边界,洋盆闭合后陆—陆碰撞对接作用,是缝合带北侧产生大量晚古生代岩浆岩的原因。
[Abstract]:The study area is located on the north side of Erlian-Hegen Mountain ophiolite belt of Xingmeng orogenic belt, and the late Paleozoic tectonic magma is widely developed in the northern part of Erlian-Hegenshan ophiolite belt. Based on the accurate geochronology and geochemistry of granitic porphyry and meso-fine-grained granodiorite in the late Paleozoic tectonic magmatic belt, combined with the previous data of late Paleozoic magmatic rocks, The genesis and tectonic setting of the late Paleozoic intrusive rocks in the northern part of the Hegenshan tectonic belt are systematically studied. It provides new evidence for the final closing time of Siberian plate and North China plate and the history of collision and evolution. The northern intrusive rocks of the Hegenshan tectonic belt studied in this paper are located in the Dalasumu area, and the lithology is of medium and fine granodiorite and granitic porphyry. The LA-ICP-MS dating method is used for the dating of medium and fine granodiorite and granitic porphyry. Zircon U-Pb age of 328 卤2 Ma-MSWD3) and 304 卤2 Ma(MSWD=2.0).SiO2 content of 67.91and 71.98Al _ 2O _ 3 are 14.04and 14.85Al _ 2O _ 3, 0.32and 0.37mg / 0.37mg respectively, which are between quasi-aluminum-peraluminous granitic granites. In the northern part of the Erlian-Hegenshan ophiolite belt, there are 330 Ma~300 Ma Carboniferous intrusive rocks mainly composed of calc-alkaline and high-potassium calc-alkaline series, and a magmatic belt dominated by type I granitic magma is formed in the northern part of the Erlian-Hegenshan ophiolite belt. As the boundary of the late Paleozoic suture belt, Erlianhaot-Hegen Mountain ophiolite belt is the reason of the late Paleozoic magmatic rocks produced in the northern side of the suture zone.
【学位授予单位】：中国地质大学(北京)
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：P597.3;P588.1

【相似文献】