Petrochemical Study of Alkali Granite in northern Area of the Uljin Mine

울진광산(蔚珍鑛山) 북부지역(北部地域)에 분포(分布)하는 알카리화강암(化崗岩)에 대(對)한 암석지화학적(岩石地化學的) 연구(硏究)

This study is focused on petrochemistry and petrogenesis of alkali granite which exposed at northern area of the Uljin mine in NE Korea. The rock is corresponded to the range of alkali feldspar granite and alkali feldspar quartz syenite on IUGS classification and contains characteristic Fe-rich biotite (annite) and sodic alkali amphibole (arfvedsonite). The alkali granite is the hypersolvus one-feldspar granite which is characterized by the absence of plagiclase except as a component of perthite and its normatve An contents are less than 5wt%. The bulk compositions of the alkali granite show reverse trends compared to Daly's. Tuttle and Bowen (1958) experimentally support that properties of the hypersolvus granite indicate that they have crystallized at high temperatures from a magma.