HASTINGSITIC HORNBLENDES FROM THE AKAGANE DISTRICT, KITAKAMI MOUNTAINS, JAPAN

Abstract

In the Akagane district, Iwate Prefecture, bluish green hornblendes are frequently observed in the silicified parts of thermally metamorphosed dacitic tuff, forming small veins and clots. Three hornblendes separated from the TA-7 drill cores in the district were chemically analysed. They belong to ferrohastingsite, rich in Fe⁺² and Fe⁺³, with mg=0.10-0.30.