Remarks on Mineralization of Some Epithermal Ore Deposits Bearing Gold and Silver

Abstract

The epithermal ore deposit of Numanoue and Takatama Mine which has been worked mainly for gold and silver is thought to have deposited following continuous igneous activities, while the epithermal ore deposits of Oe and Kinkaseki Mines which have been worked principally for base metals accompanying gold and silver are understood to have deposited after geological structure movements.
In this paper, the writer would present a report for these mines in regard to the following:
i)The location where mineralization occurred.
ii)The relation between first stage mineralization (rock alteration stage) and igneous activities.
iii)The sequence of gangue and ore minerals.
iv)The correlation among various stages of repeated mineralization.
The mineralization appears to have repeated in all of these cases, but judging from the sequence of gangue minerals, ore minerals and minor elements, the mineralization in the cases of Takatamaa and Oe Mines is thought to have repeated from the identical ore magma while in the cases of Numanoue and Kinkaseki it is thought to have repeated from the different one.
In all of these ore deposits, gangue and ore minerals of low, middle and high temperatures occur in paragenetic form showing a xenothermal tendency which is also true in the case of minor elements.
In conducting a more detailed study on the sequence of gangue minerals, ore minerals and minor elements of these ore deposits hereafter, a consideration necessary should be on their geochemical and geophysical conditions.