Statistical Analysis of the Veins of the Takatama Mine, Fukushima Prefecture, Japan

Abstract

This study on the gold veins of the Takatama mine involves statistical analyses and genetic considerations based on various results of the analyses and conventional geological observation.
The factors used for the statistical analyses are strike, dip, width and grade of the veins. Measurements were made at 346 spots 1.5 meters apart in the No. 1 vein, No. 2 vein and No. 4 vein in the No. 2 ore deposit. The general feature of the vein system is shown by stereographic projection of the data on the Schmidt's net. Some features of mineralization were made clear from the correlations between width and strike, width and dip, gold and silver contents, etc. The assay map of the vein shows that silver contents are more variable than gold contents. The attitude of ore shoots were revealed by the distribution of gold contents and gold richness (gold content X width) and the structure of the veins. In the No. 2 vein, the trend of ore shoots passes through the W3-W2 block of the A level to the E1-E3 block of the B level. In the No. 4 vein, the trend of ore shoots passes through the E1-E4 block of the A level to the E5-E7 block of the B level and the E2-E3 block of the A level to the E8-E10 block of the B level. It may be assumed that ore shoots were formed along the currents of ore solution. Thus, the main currents of goldbearing solution were deduced. The ore solution went upward through the cracks in the direction of north-west.