Abstract
Many granitic rocks occur in the Green tuff region of the northeastern Japan. Many of these rocks have hitherto been considered as the base of the Tertiary formation, but in the Waga district along the Okoku railway line, there are many granitic intrusives which show various forms such as irregular masses, dykes and tongues. This paper describes mainly the occurrence, petrographic feature, and chemical property of these intrusives. The writers have been able to distinguish the green tuff to the two formations in this district. One of them is penetrated by granitic rocks and the other covers uncomformably the same rocks. The granitic rocks, occurring in elyke forms are quartz diorites and in irregular masses are granodiorites.
