1961 Volume 11 Issue 45-46 Pages 7-11
The aspect of Kuroko-deposits is extremely complicated. Their characteristics vary with different mines, and even within the same mine it is not unusual for the properties of the deposits or ores to differ from part to part. This variety that characterizes Kuroko-deposits leads us to conjecture considerable complications in the processes they underwent in their formation. Because of such reasons, a great number of diverse theories have been proposed on their genesis.
Through the perusal of many of these theories and microscopic observation of ores and country rocks, the author reached the conclusion that, though the most important part of the mineralizing action of Kuroko-deposits is replacement by comparatively low-temperature alkaline thermal solutions, there was a period when a part of the mineralizing action was from acid thermal solutions produced by the oxidation of alkaline solutions, and that in the early period of mineralization, the deposits were partly xenothermal, following rather complicated changes.