T.M. Dai's scientific contributions

... In the southern margin of North China Block, the mid-late Cretaceous (120-100 Ma) granites also have large variations in zircon ε Hf (t) values (ranging from −26.3 to −13.5) and two-stage model age(ranging from 2040 to 2860 Ma) [12], which is consistent with the Leimengou granitic rocks. Previous studies on the zircon U-Pb and Ar-Ar geochronology of the crystalline basement Taihua Group on the southern margin of the North China Block indicate that the formation time of the Taihua Group was about 2700 Ma, and the metamorphism occurred within the range of 2200 to 2300 Ma [36,37].It can be concluded that the Taihua Group is probably the main source region of the Leimengou intrusion. However, the Leimengou granitic rocks show large variations in zircon ε Hf (t) values (11 ε units), suggesting more than one sources. ...