内蒙古孟恩陶勒盖岩体的成岩时代——LA-ICP-MS锆石U-Pb同位素年代学

PETROGENIC AGE OF MENGENTAOLEGAI INTRUSIVE BODY IN INNER MONGOLIA:LA-ICP-MS zircon U-Pb Isotopic Geochronology

摘要: 孟恩陶勒盖岩体侵位于兴蒙造山带晚古生代浅变质岩系内，根据岩石类型划分为中细粒英云闪长岩、花岗闪长岩和二长花岗岩3个填图单位，具有典型S型花岗岩的矿物组成和岩石化学特征.花岗闪长岩和二长花岗岩LA-ICP-MS锆石U-Pb同位素年龄测定结果分别为234±1 Ma和230±1 Ma，时代为中三叠世，代表孟恩陶勒盖岩体的侵位时代.

Abstract: The Mengentaolegai intrusive body, emplaced in the Late Paleozoic epimetamorphic series in Xingan-Mongolia orogenic belt, is lithologically classified into medium-fine-grained tonalite, granodiorite and monzogranite, with the mineral assemblages and petrochemical characteristics of S-type granite. The LA-ICP-MS zircon U-Pb isotopic age dating results of the granodiorite and monzogranite are 234±1 Ma and 230±1 Ma, respectively, in Middle Triassic, which represents the invasion time of the Mengentaolegai intrusive body.