Polymetallic Mineralization at the Shin-Ohtoyo Deposit, Harukayama District, Hokkaido, Japan.

Accession number;99A0753366
Title;Polymetallic Mineralization at the Shin-Ohtoyo Deposit, Harukayama District, Hokkaido, Japan.
Author;IMAI A(Univ. Tokyo, Tokyo, Jpn)   MATSUEDA H(Hokkaido Univ. Museum, Sapporo, Jpn)   YAMADA R(Dowa Mining Co. Ltd., Tokyo, Jpn)   MASUTA K(Metal Mining Agency Of Japan, Tokyo, Jpn)   
Journal Title;Resour Geol
Journal Code:G0131A
ISSN:1344-1698
VOL.49;NO.2;PAGE.75-88(1999)
Figure&Table&Reference;FIG.7, TBL.9, REF.25
Pub. Country;Japan
Language;English
Abstract;The Shin-Ohtoyo Cu-Au deposit is located in the Harukayama district, 20km west of Sapporo, Hokkaido, Japan. Both acid-type disseminated and adularia-quartz-type vein Au mineralizations have been recognized within a small distance of less than 500m in the district. Mineralogical characteristics of sulfide ores from the Shin-Ohtoyo deposit have been proved to be polymetallic. Ore minerals containing Sn, V, Bi and Te are recognized. Nine ore types are recognized in terms of characteristic mineral assemblage; (1) chalcedonic quartz veinlets in silicified zone around the deposit, (2) bismuthinite, emplectite, .+-.friedrichite and tetrahedrite, (3) an unnamed Cu-Sn-Fe-Zn sulfide, colusite-series minerals, .+-.stannoidite, emplectite and tetrahedrite, (4) bournonite, Se-bearing galena and tetrahedrite, (5) Iuzonite/famatinite and Ag-bearing tetrahedrite, (6) colusite-series minerals, emplectite, aikinite and tetrahedrite/goldfieldite, (7) Iuzonite/famatinite, colusite-series minerals, mawsonite and tetrahedrite/goldfieldite, (8) enargite, Iuzonite/famatinite and tetrahedrite, and (9) colusite-series minerals and tetrahedrite. The first occurrence of friedrichite and stibiocolusite from Japan are reported. The chemical formula of the unnamed phase corresponds to Cu6(Cu, Fe, Zn)Sn3S10. Sulfur isotopic ratios (.DELTA.34S) of sulfides from the stockpile range from -0.5.PERMIL. to +1.9.PERMIL., and those from drill cores recovered by Metal Mining Agency of Japan (MMAJ) vary from -2.7.PERMIL. to +0.8.PERMIL.. Sulfur isotopic ratio of barite in a cavity in the silicified tuff breccia collected from the stock pile yields +27.1.PERMIL., while that of barite collected from MMAJ core is +21.7.PERMIL.. Sulfur isotopic thermometry applied for a pair of barite (+21.7.PERMIL.) and associated pyrite (+1.8.PERMIL.) indicates about 300.DEG.C..... (author abst.)