연구논문 : 영일반도 일원의 화산암류에 대한 암석학적 연구

The purpose of this study is to determine the stratigraphy in the Yeongil peninsula, southeastern Korea, based on field survey, lithological and petrochemical properties of the rocks. The area consists of, in ascending order, Cretaceous sedimentary rocks(Balsandong Formation), granite, Eocene Duilpo andesite, Gangsari tuff, Gumanri rhyolite, acid to intermediate dikes, and Miocene Janggi conglomerate, Nuldaeri tuff, Hudongri tuff, Gonggaesan dacite, Guryongpo andesite, Guryongpo rhyolite breccia, Yeovil basalt, Imgok Formation and alluvium. Geochemical analyses for 24 samples from the volcanic rocks show the parent magma for forming the volcanic rocks belongs to calc-alkaline rock series with medium K content. And petrochemical compositions of the Eocene volcanic rocks have a tendancy to change in composition from andesite, dacite to rhyolite. showing a serial differentiational products by fractional crystallization. But the Miocene volcanic rocks have a tendancy from rhyolite, dacite, andesite to basalt in composition, which were formed by magma mixing between residual silicic magma and newly formed basalt magma derived from the mantle.