Statistical Analysis of the Veins of the Okuchi Mine

Abstract

This study on the gold veins of the Okuchi mine involves statistical analyses and genetic considerations based on various results of the analyses and conventional geological observations. The factors used for the analyses are strike, dip, width, and grade of the veins. Measurements were made at 400 spots 1.5 meters apart in. the B and E veins. The general feature of the vein system is shown by stereographic projection of the data on the Schimidt's net. The figure is called F diagram in this paper.
Some features of mineralization were made clear from the correlations between width and strike, width and dip, gold and silver contents, etc. The attitude of ore shoots was revealed by the distribution of gold contents and richness (gold content × width) of the veins. It may be assumed that ore shoots were formed along the currents of ore solution. Thus, the main currents of gold-bearing solution were deduced. In the B vein the solution passed through the W 17-W 7 block of No.4 level and rose along the fractures running N 64°-69° E with a dip of about 64°SE and reached the W 20-W 14 block of No.3 level. On the other hand, in the E vein gold-bearing solution passed through the E 13-E 22 block of No.6 level and rose along the fractures running N 54°-66° E with a dip of about 66° NW and reached the E 7-E 14 block of No. 4 level. The inferred currents of the ore solution seem to suggest there is a genetic relation between the veins studied and the neighbouring Honzan vein group.