Ores and Ore Minerals from the Volcanogenic Massive Sulfide Deposits of the Shimokawa Mine, Hokkaido, Japan
Ores and Ore Minerals from the Volcanogenic Massive Sulfide Deposits of the Shimokawa Mine, Hokkaido, Japan
复制标题
日本北海道下川矿火山成因的块状硫化物矿床的矿石和矿石矿物
DOI：
10.11456/shigenchishitsu1951.38.233
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发表时间：
1988
期刊：
影响因子：
--
通讯作者：
Tadashi Mariko
中科院分区：
文献类型：
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作者：
Tadashi Mariko
下川块状硫化物矿床矿石主要由黄铁矿、磁黄铁矿、黄铜矿、闪锌矿和磁铁矿组成。在显微镜下可观察到少量钴镍矿、钴镁矿、铜长石、钴矿和方铅矿。脉石矿物有石英、方解石、菱铁矿、绢云母、绿泥石、角闪孔、磷灰石和碳质物质。黄铁矿-磁黄铁矿-磁铁矿-菱铁矿组合被认为是在接近250•Ž、101.7 atm fco2、10-38 atm fO2和10-14 atm fs2的条件下形成的。黄铁矿-黄铁矿-cubanite-黄铜矿组合在300或350•Ž以上形成的黄铁矿-硫铁矿-磁黄铁矿组合的逆行过程中，fs2的微小变化改变了黄铁矿-黄铁矿-黄铁矿组合。单斜磁黄铁矿与黄铁矿之间的钴铁分异温度为200 ~ 300•Ž，六方磁黄铁矿为270 ~ 350•Ž。脉石矿物组成以菱铁矿和方解石为主要成分，与估计的富含碳质物质的海底环境相一致，并有邻近大陆地区充足的弹性供应。
Ores of the Shimokawa massive sulfide deposits are composed mainly of pyrite, pyrrhotite, chalcopyrite, sphalerite, and magnetite. Minor amounts of cobalt pentlandite, cobaltian mackinawite, cubanite, cobaltite, and galena are observed under the microscope. Gangue minerals are quartz, calcite, siderite, sericite, chlorite, amphibole, apatite, and carbonaceous materials. The assemblage of pyrite-pyrrhotite-magnetite-siderite is considered to have been formed under a condition close to 250•Ž, 101.7 atm fco2, 10-38 atm fO2, and 10-14 atm fs2• The pyrrhotite-pyrite-cubanite-chalcopyrite assemblage has been modified by a small change in fs2 during the retrograde process from iss-pyrite-pyrrhotite assemblage formed above 300 or 350•Ž. The cobalt-iron partition temperatures between pyrrhotite and pyrite are 200-300•Ž for monoclinic pyrrhotite-pyrite and 270-350•Ž for hexagonal pyrrhotite-pyrite. The gangue mineral composition containing siderite and calcite as the main constituents is consistent with the estimated submarine environment rich in carbonaceous materials where an adequate supply of elastics from adjacent continental areas was available.