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

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.