1981 Volume 31 Issue 167 Pages 157-168
In the Kamioka silver-lead-zinc mining area, zonal arrangement of ore and skarn minerals is recognized in accordance with the distance from the rock mass called metabasite. Besides mineral assemblage data, Ag-Pb-Zn ratio in ore and decrepitation temperature of skarn minerals can be used to delineate the zoning pattern. Molybdenum mineralization with actinolite skarn occurs in some zones overlapping the silver-lead-zinc mineralization, and is likely to be related to the activity of granite porphyry.
There are four types of Ag-Pb-Zn ores in the mining area; "mokuji" type, "shiroji" type, dissemination type and gold-silver type. The mokuji type ore, which is most prevalent and appears to have the highest formative temperature in this mineralized sphere, is found, without exception, in contact with the Inishi-type migmatite.
Thus, it is thought that the silver-lead-zinc mineralization in this mining area has been genetically related to the metabasite and the Inishi-type migmatite. Distribution of these rocks, and therefore the indication of silver-lead-zinc mineralization, is confined to a specific tectonic unit of the Hida metamorphic belt, named the Central massif.
It has been suggested from the ore lead isotopic data that leads in this area came from more than a single source of material. There is also some indication that primary concentration of Ag-Pb-Zn in this area might have occurred prior to the formation of the migmatite and the metabasite.
