著者

小島 晶二 苣木 浅彦

出版者

Japan Association of Mineralogical Sciences

雑誌

岩石鉱物鉱床学会誌 (ISSN:00214825)

巻号頁・発行日

vol.78, no.12, pp.491-496, 1983-12-05 (Released:2008-08-07)

参考文献数

13

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From the Senzai vein of the Oe mine situated in southwestern Hokkaido, some kinds of rhodochrosite stalagmites are sometimes found out at the bottom of druse within the vein. The stalagmites show the shape of column, 2 to 30mm in diameter and 1 to 12cm in length. They consist of irregular fan-shaped crystals superficially and show the solution growth textures such as concentric bandings. These stalagmites have the chemical compositions of 53 to 89 mole % MnCO3, 2 to 20 mole % CaCO3. 7 to 26 mole % FeCO3 and 1 to 9 mole % MgCO3, which are mostly within the compositional region of drusy rhodochrosite of the vein. Chemical compositions of the rhodochrosite stalagmites change markedly with the concentric bands as shown in Fig. 7, which shows considerable increase of MnCO3 content from core to rim. This feature is considered as being due to chemical changes of the ore solution or ground water producing the rhodochrosite stalagmite.

著者

苣木 浅彦 鈴木 喜義

出版者

The Society of Resource Geology

雑誌

鉱山地質 (ISSN:00265209)

巻号頁・発行日

vol.10, no.41, pp.152-167, 1960-06-30 (Released:2010-03-04)

参考文献数

19

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以上述べた事柄を要約すればつぎのようである.1)与内畑鉱山の鉱床は第三紀中新世上部に属すると思われる黒色泥岩層を母岩とする黒鉱式石膏鉱床である.2)産出鉱物としては石膏のほかに少量の黄鉄鉱,黄銅鉱,閃亜鉛鉱および方鉛鉱の金属硫化鉱物,硬石膏,螢石,重品石および方解石などを随伴する.3)上記産出鉱物の生成順序は第17図のようで,硬石膏,螢石,重晶石および方解石はしばしば石膏にて交代せられている.4)石膏鉱体は塊状を呈し,その中央部は塊状石膏を主とする高品位部であるが,その周辺部は母岩の粘土分を混えて鉱染ないし網状石膏鉱体となり,さらにその外緑部は繊維石膏の細脈を伴う黒色粘土化帯に移化する.5)黒色泥岩層中に挾有される凝灰質泥岩は前者に比して石膏の鉱化作用を蒙りがたく,しばしば部分的にcap rock的な役割をなし,その下盤に接して石膏鉱体を胚胎している.6)母岩の変質は著しい粘土化作用と,都分的な珪化詐用とがあり,揃者は石膏の鉱化作用とほぼ時を同じくして行なわれ,後者はこれに先行するものと考えられる.7)粘土化作用による化学的成分の変化は第2表のごとくで著しいMgOの増加と脱珪作用とが特徴的で,ごの結果苦土緑泥石およびモンモリオナイトの生成がみられる.8)黒色泥岩はこれに挾有される凝灰質泥岩に比し人工鉱液に対し石膏を生成しやすく,かつまた,より容易に溶液の拡散を受けやすい.9)本鉱床産石膏の大部分はCa¨およびSO4′′を含む鉱液の物理的条件の変化にもとづく化学沈澱によると推察され,鉱体はある一定のhorizon付近,あるいはその当時の地表より一定の深度付近に胚胎したものと考えられる.

著者

磯部 清 保科 恒二 苣木 浅彦

出版者

The Society of Resource Geology

雑誌

鉱山地質 (ISSN:00265209)

巻号頁・発行日

vol.17, no.81, pp.22-37, 1967-02-28 (Released:2009-12-11)

参考文献数

13

被引用文献数

1

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The Isobe Koyama mine is situated at about 30 kilometers northwest of Yamagata City and is producing copper and gold ores. The district is composed mainly of Miocene pyroclastic rocks and their lava flows of intermediate to acid type with some mudstone. The ore deposits of this mine consist of twelve bodies which occur in mudstone, muddy tuff, and green tuff. They are of an epithermal type and occuring veins, stockwork or as disseminating bodies. Native gold, chalcopyrite, sphalerite, pyrite, and galena, are the principal ore minerals, associated with such gangus minerals as quartz, kaolin, chlorite, barine and carbonate minerals.Native gold occurs in intimate association with quartz, kaolin, sphalerite and chlcopyrite. The ore comprising chalcopyrite, sphalerite chlorite and quartz is often so rich in gold that its gold tenor is more than one kilogram per ton. However, the grade of silver in the ore is always less than that of gold. The gold-silver ratio is a characteristic of the ore from the mine in comparison with that of the ores from the so-called epithermal gold-silver deposits in which the tenor of silver is usually ten or several ten times of that of gold.The vertical zoning of ore deposit is obvious, often divided into the following five zones from upper to lower : 1) quartz-kaolin zone, 2) quartz-kaolin-sphalerite zone, 3) sphalerite zone, 4) sphalerite-chalcopyrite zone and 5) chalcopyrite zone. The native gold occurs in the zones 1), 2), 3) and 4), especially richest in zone 4). In zone 5 ), the tenor of gold rapidly decreases to less than 2 grams, per ton. This zoning is also found in lateral derection. The central zone is the chalcopyrite zone, which may indicate a center of mineralizaton in this mine. Also, the fissures filled with ores seem to be mostly tension fractures, judging from their pattern.

著者

苣木 浅彦 島 敞史 北風 嵐

出版者

Japan Association of Mineralogical Sciences

雑誌

岩石鉱物鉱床学会誌 (ISSN:00214825)

巻号頁・発行日

vol.73, no.3, pp.63-77, 1978-03-05 (Released:2008-08-07)

参考文献数

40

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To reconfirm whether minerals of luzonite-famatinite series form complete solid solution between them as Springer (1969) reported or limited solid solution having immiscibility gap from approximately 10 to 40 mol% Cu3SbS4 as Skinner (1960) inferred. 16 samples of luzonite and famatinite from 7 mines in Japan, Formosa and Philippines were examined by electron probe microanalyser (EPMA). The quantitative analytical data by EPMA for the samples are given in Tables 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12 and 13. The specimens from the Hokuetsu mine, Japan and the Mankayan mine, Philippines have most nearly stoichiometric composition of luzonite as from 0 to 3 mol% Cu3SbS4. They from the Lobo mine, Philippines and the Kinkaseki mine, Formosa have from 2 to 12 mol% Cu3SbS4, and from 2 to 7 or 36 to 41 mol% Cu3SbS4 in composition, respectively. Also luzonite-famatinite series minerals from the Teine, Kasuga and Akeshi mines, Japan have compositions of such wide range as from 19 to 71, 26 to 82 and 3 to 78 mol% Cu3SbS4, respectively. However, the composition corresponding to stoichiometric Cu3SbS4 of famatinite was not found during this study. Analytical data for 378 points in 16 specimens are summarized as shown in Fig. 5, and it is found that there is existance of minerals having continuous compositions between luzonite and famatinite except nearly famatinite end. Therefore it is concluded that the complete solid solution between them exists at low temperature as the result of Springer's examination.