岩手県釜石鉱山天狗森鉱床産の磁鉄鉱の化学組成

Abstract

The microstructure and chemical composition of magnetite from the Tengumori ore deposit in Kamaishi Mine were investigated. The magnetite from the Tengumori ore deposit is silician and has a structure that partially has an exsolution texture. The estimated temperature of crystallization of magnetite is in the range of 660-400℃ using the magnetite geothermometer. This temperature range is 200-100°C higher than that obtained from thermochemical analysis about skarn mineral assemblage. In the Kamaishi Mine, the crystallization temperature of magnetite from the Tengumori ore deposit is similar to that of the Sahinai ore deposit and higher than that of the Shinyama ore deposit. This trend is different from the conventional one of the formation temperatures of the skarn minerals in the Kamaishi Mine.