Iron-Manganese Deposits of Kunimiyama Mine, Kochi Prefecture.

Abstract

The Kunimiyama Mine is about 15 km north of Kochi City. The ore bodies of the mine are typical of the iron-manganese ore deposits in Japan.
The rocks in this region belong to the Chichibu Paleozoic system and are quartzite, schalstein, sandstone, clayslate, and tuffaceous clayslate bearing other slumped rocks. Diabase intrusives are probably of Cretaceous age.
The ore deposits of the Kunimiyama Mine occur as lenticular or irregular platy bodies between quartzite and schalstein in most cases. In general, the shape of the ore deposits is related to folds of country rocks.
Alteration of the wall rocks in these ore deposits took place in the following order: silicification→infusion of iron as the oxide→carbonatization, chlorititzation, serpentinization, silicification.
Fossiliferous carbonate rock is intercalated in between the ore bodies and quartzite.
The main ore is an iron-manganese ore consisting of minerals like bixbyite and sitaparite. The following order of crystallization of ore minerals is recognized minerals like bixbyite and sitaparite→rhodonite rhodochrosite→penwithite, bementite.