北海道轟鉱山の金銀鉱床の鉱石

抄録

The characteristic properties of gold-silver ores from the Todoroki ore deposits and the Nakanosawa ore deposits which are epithermal gold-silver quartz veins of Tertiary age in the southwestern part of Hokkaido, were studied, and some conditions of ore formation are discussed.
The Chuetsu-hi vein and the Shuetsu-hi vein, principal veins in the Todoroki ore deposits, are similar in the vein scale, the vein pattern, the trend of ore shoots, the mode of occurrence of ores, the ore textures, the mineral assemblages of ores, and the wall rock alterations. And the Nakanosawa ore deposits show similar characteristics as regard the vein pattern, the trend of ore shoots, the mode of occurrence of ores, and the wall rock alterations. The wall rocks, however, differ among veins (i. e., Chuetsu vein; rhyolite and its pvroclastic rocks. Shuetsu vein: sedimentary and nvrcclastic rockc Nakanosawa ore deposits; dolerite) and gold-silver ores show different features in mineralogical and chemical compositions, and in the properties of some constituent minerals.
Data on the fluid inclusion, mineral associations and chemical compositions of minerals give some similar but slightly different physicochemical conditions of ore formation between the Chuetsu-hi vein and the Shuetsu-hi vein.