Notes on the Ore Deposits of the Nakase Mine in Hyôgo Prefecture, Japan.

AKATSUKA Kyûbê

Journal of science of the Hiroshima University. Series C, Geology and mineralogy

The Nakase Mine is situated at Yoshii, Sekinomiya-chô, Yabu-gun, Hyôgo Prefecture, Japan and its surroundings are geologically consisted of the Sangun metamorphics, serpentinite, granitic rocks, Manju volcanics, Kinosaki Subgroup belonging to Hokutan Group, Saruo-no-taki dikes including micro- quartz-diorite, Tentaki lavas belonging to Daisen volcanics, and basaltic dike in descending sequence.
It seems to be remarked that the ore bodies of this mine are found deposited as lodes mainly in the metamorphics as well as in the Manju volcanics, micro-quartz-diorite, and rather scarcely in serpentinite or others but are cut in particular by basaltic dikes. The ores concerned are naturally assumed to have been produced through certain processes in four main periods. such as Period I, Period II, Period III, and Period IV. The fact of importance is that activities of porphyrite and breccia dikes are evidently recognizable intervening between Period II and Period III.
Certain minerals selected out from more than twenty-eight specimens are röntgenometrically scrutiniz-ed, whereas horizontal or vertical variations in their assemblages as well as in genetic relation are not conspicuously determinable within each lode.
It however results in at least that the main lodes originated in Period III, that is the veins containing gold, silver, and antimony ores, especially seem to be grouped into an ordinary category of epithermal de-posit.

eng

HIROSHIMA UNIVERSITY

[ISSN] 0075-4374

[NCID] AA00706718