Since 1954, the writer has come to believe the existence of a folded structure in the eastern area of the Hitachi deposit.
As the result of geological surveys, the Hitachi main and the Irishiken ore zones can be interpreted as forming a synclinal structure, having its apex near the Sasame ore bodies on the eastern extremity of the main ore zone.
According to this theory, we had started the exploration for unknown areas in 1954, and the Fujimi ore bodies were newly found in 1956 between the Irishiken and the Sasame ore bodies.
Since 1956 to 1960, we have developed the Fujimi ore bodies from the 0 m level to the 550m level, and the new shaft planning for the Fujimi ore bodies is now under way.