1991 Volume 41 Issue 226 Pages 63-75
The Hishikari gold mine consists of three epithermal vein-type Au-Ag deposits, named Honko, Yamada, and Sanjin. Honko deposit, which was discovered in 1981, has been producing gold and silver at the rate of 350-400t per day since 1985. Yamada deposit, located at 1.2km southwest of Honko deposit, was discovered in 1988 by surface drilling and started production in April 1991. Chemical analyses of 37 elements were carried out on 282 ore samples from Honko deposit and 142 samples from Yamada deposit. The samples are collected from drill core drilled from both surface and underground. As a result of the statistic analysis (correlation and principal component analysis) for the chemical compositional data, there are some differences between ore of Honko and of Yamada. For instance, they are,
(1) The ore of Honko is richer in most of the elements than that of Yamada, but is poorer in As, LOI, Mn, and Ni.
(2) The standard deviation of K 20 is larger in Yamada.
(3) Sb is concentrated in the high Au grade ore zone in Honko, while Sb and Au are hardly correlated in Yamada.
(4) The factor loadings of Factor 2 may indicate that Au-Ag mineralization, and range of high scores of Factor 2 was between 100ML and 40ML in Honko, but was not identified in Yamada.
These differences may suggest that the chemical condition or environment of formations of Honko and Yamada deposit was not similar.
