ABSTRACT

K-Ar dating was performed for four volcanic rocks from three stages of the Ulreung Island, situated off eastern coast of the Korean Peninsula. The results are consistent with volcano-stratigraphic succession. Presently accumulated data of age and chemical compositions indicate that the subaerial volcanism of Ulreung Island was active from late Pliocene through Pleistocene and well comparative with that of Oki-Dogo Island being located about 60 km off the coast of SW Japan in the Sea of Japan.