S3: Tectonics of East Asia (Special Session)

[S3-01] Zircon U-Pb dating of granitoids in western Nagasaki, southwest Japan

*Yukiyasu Tsutsumi¹, Kenichiro Tani¹ (1. Department of Geology and Paleontology, National Museum of Nature and Science)

Keywords:zircon, U-Pb age, granitoid, Nagasaki, Ryoke

Zircons U-Pb ages were obtained from granitoids in western Nagasaki Prefecture. Considering the ages, it is thought that granitoids in Enoshima Island and Irose Shoal emplaced ~100 Ma whereas Oseto and Otate emplaced in ~97 Ma and Oseto suffered later activity in ~90 Ma. These ages are equivalent of the granitoids in the Ryoke belt. The Oseto granodiorite contacts the Nagasaki Metamorphic Complex which is equivalent of the Sanbagawa belt, across the Yobukonoseto fault system. These data will be important when considering the framework of Kyushu.