| 王静,王学武,邓明国,孙涛.新疆四顶黑山花岗岩体锆石LA-ICP-MS U-Pb年龄及地质意义[J].地质找矿论丛,2018,33(3):365-374 |
| 新疆四顶黑山花岗岩体锆石LA-ICP-MS U-Pb年龄及地质意义 |
| LA-ICP-MS zircon U-Pb age of the Sidingheishan granitic pluton from east Tianshan, Xinjiang, China, and its geological implications |
| 投稿时间：2017-03-04 修订日期：2018-06-06 |
| DOI：10.6053/j.issn.1001-1412.2018.03.006 |
| 中文关键词: 岛弧型花岗岩 四顶黑山 花岗岩 东天山 新疆 |
| 英文关键词:Island arc granite Sidingheishan granite east Tianshan Xinjiang |
| 基金项目:国家自然科学青年基金项目（编号：41402070）、中国地质调查局项目（编号：DD20160346）联合资助。 |
|
| 摘要点击次数: 1094 |
| 全文下载次数: 922 |
| 中文摘要: |
| 新疆东天山位于中亚造山带南缘，天山-兴安造山系北天山造山带东段，发育大量泥盆纪-石炭纪花岗岩，其形成过程多与觉罗塔格洋的俯冲作用有关。四顶黑山花岗岩体位于东天山觉罗塔格构造岩浆带的东端，岩体在地表呈不规则状产出，侵位于元古界片岩-变火山岩、奥陶系变玄武岩和泥盆系雀儿山群火山岩；主要岩石类型为花岗岩和花岗闪长岩。花岗岩的LA-ICP-MS锆石U-Pb年龄为380.4 Ma±3.7 Ma，表明岩体形成于晚泥盆世。岩石表现出高硅（w（SiO2）=64.87%~74.71%）、高碱（w（K2O）=3.35%~4.68%，w（Na2O）=2.26%~3.85%）、富铝（w（Al2O3）=11.82%~14.13%）和低MgO（w（MgO）=0.56%~2.12%）、CaO（w（CaO）=1.68%~3.74%）、TiO2（w（TiO2）=0.26%~0.57%）、P2O5（w（P2O5）=0.01%~0.19%）特征，A/CNK=0.83~1.00；富集Ba、K、La、Ce、Nd，亏损Th、Nb、Ta、Sr、Ti，铕负异常较明显（δEu=0.70~0.73）；具有岛弧型花岗岩特征。四顶黑山花岗岩体形成于岛弧环境，属于觉罗塔格洋向南俯冲过程中的产物。四顶黑山花岗岩体两侧的镁铁-超镁铁质岩体的形成时代应晚于晚泥盆世。 |
| 英文摘要: |
| The east Tianshan orogenic belt, Xinjiang, NW China, is located at east part of the north orogenic belt of Tianshan-Xinganling orogenic system in the south margin of the Central Asian Orogenic Belt (CAOB). The Jueluotage palaeoocean crust subduction-related Devonian-Carboniferous granites are well developed here. The Sidingheishan granitic pluton in the eastern part of the Jueluotage tectonic belt, east Tiuanshan emplaced in Proterozoic shist and metavolcanic rocks, Ordovician metabasalt and Devonian volcanic-sedimentary rocks of the Que'rshan group and outcrops irregularly at surface. It is composed mainly of granite and granodiorite.The LA-ICP-MS zircon U-Pb dating of the granite is 380.4±3.73 Ma reflecting that the it was formed at late Devonian period. Petrological and geochemical data show that the pluton is characterized by high silicon(w(SiO2)=64.87%~74.71%), high alkali(w(K2O)=3.35%~4.68%,w(Na2O)=2.26%~3.85%), abundant aluminum(w(Al2O3)=11.82%~14.13%)and low MgO(w(MgO)=0.56%~2.12%), CaO(w(CaO)=1.68%~3.74%), TiO2(w(TiO2)=0.26%~0.57%), P2O5 (w(P2O5)=0.01%~0.19%), ratio of A/CNK=0.83~1.00. enrichment of Ba, K, La, Ce, Nd, depletion in Th, Nb, Ta, Sr and Ti, and low δEu value(δEu=0.70~0.73). All of these show that the Sidingheishan granitic pluton fromed in the island arc environment and related with the S-dipping subduction of the Jueluotage palaeoocean. The mafic-ultramafic intrusion on either side of the granitic pluton should be formed after the late Devonian. |
| 查看全文 查看/发表评论 下载PDF阅读器 |
| 关闭 |
|
|
|
