Geology and Ore Deposit of the Iimori Mine

with Special Reference to the Petrofabric Characters of the Ore-body and the Country Rocks.

Abstract

The bedded cupriferous pyritic deposit of the Iimori mine is concordant in green schist of the socalled Sambagawa zone. The ore deposit is a tabular body, 0.2-2.8m thick and extends 250-300 m along the dip. The linear direction of the ore-body coincides with the lineation observed in the country rocks.
Petrofabric analyses indicate that the prevailing schists of the district are B-tectonites and the direction of the lineation coincides with the B-axis. Thus the linear direction of the ore-body of the bedded cupriferous pyritic deposit of the Iimori mine, coincides with that of the B-axis.
The joints nearly perpendicular to the direction of the lineation predominate in the schist and ore-body.
The quartz-grain fabric of the commonest schists shows the ac-girdle distinctly, further the acgirdle is imprinted on the quartz-grain fabric of the banded ore. The grain fabric of quartz filling the interstices between pyrite crystals in the compact massive ore has no recognizable regularity.
The genesis of the ore deposit remains unknown. However, it is considered unheldly that the ore deposit was formed after the metamorphism and deformation of the country rocks had ceased completely. The ore deposit may be a pre- or para-kinematic deposit.