摘要
东昆仑东段益克郭勒侵入体主要由闪长岩、石英碱长正长岩、英云闪长斑岩及花岗闪长岩组成。锆石LA-ICP-MS U-Pb定年结果显示,闪长岩、石英碱长正长岩和英云闪长斑岩的年龄分别为(223.4±1.1)Ma、(222.9±1.3)Ma和(230.9±1.1)Ma,表明益克郭勒侵入体形成于中三叠世。益克郭勒中三叠世侵入岩属于过铝质高钾钙碱性系列,具埃达克质岩石地球化学特征,最可能为后碰撞火成岩,反映了东昆仑造山带在中三叠世晚期已经进入后碰撞造山阶段构造演化。这一成果为揭示东昆仑造山带晚印支期构造环境和动力学机制提供了重要的依据。
Yikeguole intrusion,located in the eastern segment of East Kunlun,mainly consists of diorite,quartz alkali feldspar syenite,tonalite porphyry and granodiorite.LA-ICP-MS zircon U-Pb dating shows that the ages of the diorite,quartz alkali feldspar syenite and tonalite porphyry samples are(223.4±1.1)Ma,(222.9±1.3)Ma and(230.9±1.1)Ma,respectively,indicating that the Yikeguole intrusion was emplaced during the Middle Triassic.The Middle Triassic intrusive rocks belong to peraluminous,high-K calc-alkaline series with adakite-like geochemical characteristics,and are probably post-collisional igneous rocks,which implies that the tectonic evolution of the East Kunlun orogenic belt was transferred into the post-collisional period during the late Middle Triassic.This result provides an important basis for revealing the late Indosinian tectonic environment and dynamic mechanism of the East Kunlun orogenic belt.
作者
郑振华
张勤山
何利
田滔
李生虎
ZHENG Zhenhua;ZHANG Qinshan;HE Li;TIAN Tao;LI Shenghu(Qinghai Geological Survey,Xining 810008,China;No.5 Geological Survey Institute of Qinghai Province,Xining 810099,China)
出处
《世界地质》
CAS
2022年第1期56-71,84,共17页
World Geology
基金
2019年青海省地质勘查基金项目(2019048130kc072)。
