Ore Deposits and Prospecting of the Yoshino Mine

Abstract

The Yoshino mine, 15 km southwest from Yamagata City, is one of the Kuroko-type deposits, constituting several ore bodies almost without outcrop in the Miocene Green Tuff formation.
These ore bodies, distributed from north to south, lie mainly in the eastern limb of small anticline or dome structure as revealed by the subsurface contour map of the top of the green tuff.
Gravimetric prospecting was effective in finding these buried structures, and might be an indirect way for prospecting the ore body. New interesting anomalies have been found recently.