Mineral equilibria and crystallization conditions of Ukan granodiorite (ilmenite-series) and Kayo granite (magnetite-series), San'yo Belt, southwest Japan

Abstract

Ukan Granodiorite is intruded by Kayo Granite, and both granites intruded into the Cretaceous felsic volcanic strata. Petrologic features suggest that Ukan Granodiorite magma evolved under relatively low oxygen fugacities through solidification, though oxygen fugacity increased locally at a late magmatic and/or subsolidus stage. Kayo Granite, as a whole, can be classified as the ilmenite-series granite in terms of petrogenetic scheme, but due to the late magmatic and/or subsolidus stage reactions, the magnetic susceptibility is that of the magnetite-series granite. -from Authors