富山県南西部に分布する月長石流紋岩のK-Ar年代

抄録

K-Ar age determination was carried out on two moonstones from rhyolitic welded tuff which consists of the upper part of the Futomiyama formation. The measured ages gave 24 and 25 m. y. respectively, corresponding to the lower Miocene age. The result agrees well with the stratigraphic succession of the Futomiyama formation (Yamasaki and Miyazima, 1970).