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  • 吉田 雅, 八島 隆一
    岩石鉱物鉱床学会誌
    1975年 70 巻 7 号 245-248
    発行日: 1975/07/05
    公開日: 2008/08/07
    ジャーナル フリー
    Aragonite crystals grown in the geodes of Ryozen basalts, Fukushima Prefecture, Japan, were described by means of optical microscope, chemical analysis and X-ray diffraction. The specimen consists of aggregate crystals and each crystal is prismatic, acicular and platy as shown in Fig. 2 and 3. The color of lower part of the crystal is white, the middle part is brownish or amber-like and the top transparent.
  • 周藤 賢治, 八島 隆一
    岩石鉱物鉱床学会誌
    1986年 81 巻 5 号 190-201
    発行日: 1986/05/05
    公開日: 2008/08/07
    ジャーナル フリー
    Two petrographic provinces are classified in the Miocene volcanic rocks widely exposed in areas to the east of the Quaternary volcanic front of Northeast Japan. The first is that of the island arc tholeiite in the Kitakami river area, where rocks are basalts, andesites and dacites, all being of the island arc tholeiite or calc-alkali rock series. On the other hand, the second is a mixed province of the oceanic tholeiite and the island arc tholeiite series, in which occur, in association with the island arc tholeiitic rocks, basalts and andesites occasionally rich in TiO2 and FeO*, icelandite-like andesites and dacites similar in composition to rocks of the oceanic regions. Its area extends from Sendai southwards to the Abukuma mountains district. The boundary between the two provinces corresponds to the Matsushima-Honjo line defined by Oide and Onuma (1960).
  • 周藤 賢治, 八島 隆一, 滝本 俊明
    岩石鉱物鉱床学会誌
    1985年 80 巻 2 号 55-72
    発行日: 1985/02/05
    公開日: 2008/08/07
    ジャーナル フリー
    High magnesian olivine basalts of lower Miocene age are distributed in the Ryozen district of the northeastern part of Fukushima Prefecture, Northeast Japan. Olivine basalts have low FeO*/MgO ratios (0.68-1.17) and high Cr contents (323-1193ppm). The olivine basalt R09 is sparsely phyric (phenocrysts of olivine and chromite 10⟨vol%), and the olivine phenocrysts have narrow compositional range (Fo=85-89) and high NiO contents (0.24-0.32%). The olivine phenocrysts of the olivine basalt R09 contain chromite only as inclusion. Fe-Mg partitioning of the olivine basalt R09 suggests that phenocryst of magnesian olivine (Fo=87) is in equilibrium with coexisting liquid (=groundmass).
    These features strongly indicate that the olivine basalt R09 has primitive nature in chemical composition and may represent the primary olivine tholeiitic magma generated in the upper mantle.
    Differentiated basalts having relatively high FeO*/MgO ratios may be produced from the primary magma by the fractionation of magnesian olivine, chromite and clinopyroxene.
  • 周藤 賢治, 伊崎 利夫, 八島 隆一
    岩石鉱物鉱床学会誌
    1985年 80 巻 6 号 246-262
    発行日: 1985/06/05
    公開日: 2008/08/07
    ジャーナル フリー
    Tholeiitic basalts characterized by very high TiO2 contents have been found in the northeast Japan arc. These basalts (the Motokozawa basalts) occur as lavas and minor dikes in the lower Miocene Motokozawa Formation which is distributed in the eastern part of Tochigi Prefecture, Northeast Japan.
    The Motokozawa basalts are uniform, non-porphyritic and subophitic in texture. The essential constituent minerals are plagioclase, clinopyroxenes (augite, ferroaugite, subcalcic augite and pigeonite) and Fe-Ti oxides. Fe-Ti oxides occur sporadically as euhedral crystals (3.8-6.4 modal%) and also as very fine grained crystals in the mesostasis. The Motokozawa basalts are high alkali tholeiite or quartz tholeiite according to the classification of Kuno (1968b) and Yoder and Tilley (1962), respectively.
    The quartz-normative tholeiites having high TiO2, FeO* (FeO+0.9 Fe2O3) and low K2O contents are predominantly found in the east Pacific Ocean floor, though less abundantly in other ocean floors.
    Discussions and considerations on the genesis of ocean floor tholeiites with high TiO2 and FeO* contents suggest that the Motokozawa basalts may not be produced by the fractional crystallization from the primary magma having low TiO2 and K2O contents. One of the reasonable explanations for the genesis of the Motokozawa basalts is the fractional crystallization from the primary TiO2-rich, K2O-poor magma generated in the upper mantle which had been previously enriched in Ti and depleted in K through a preceded partial melting under hydrous conditions.
  • 周藤 賢治, 八島 隆一
    岩石鉱物鉱床学会誌
    1985年 80 巻 9 号 398-405
    発行日: 1985/09/05
    公開日: 2008/08/07
    ジャーナル フリー
    Hortonolite andesites of middle Miocene age have been found in the Daigo district of the northeastern part of Ibaraki Prefecture, Northeast Japan. These andesites (the Nantaisan andesites) occur as subaqueous autobrecciated lavas and massive lavas which are also erupted in water bottom. The Nantaisan andesites are mostly aphyric, but some andesites contain small amount of phenocrysts of hortonolite, ferrohypersthene and plagioclase. An andesite specimen has ferropigeonite, hortonolite and ferrohortonolite in the groundmass. Ferropigeonite of the groundmass is lower in Fe/Mg ratio than the coexisting hortonolite and ferrohortonolite. The latter minerals bear no reaction relation to the former mineral. Bulk chemical compositions of the Nantaisan andesites are similar to those of icelandites from eastern Iceland. Differences in petrologic characters in the Quaternary and Miocene tholeiitic volcanic rocks occurring near the Quaternary volcanic front and its neighbouring Miocene volcanic field in the northeast Japan arc are described in the paper.
  • 八島 隆一
    地質学雑誌
    1959年 65 巻 771 号 725-734
    発行日: 1959/12/25
    公開日: 2008/04/11
    ジャーナル フリー
  • 大野 照文
    化石
    1996年 61 巻 61-
    発行日: 1996/12/15
    公開日: 2017/10/03
    ジャーナル フリー
  • 周藤 賢治, 一ノ瀬 丁己, 滝本 俊明, 八島 隆一
    岩石鉱物鉱床学会誌
    1986年 81 巻 8 号 312-323
    発行日: 1986/08/05
    公開日: 2008/08/07
    ジャーナル フリー
    High-magnesian tholeiitic basalts of early Miocene age are distributed on Nodegamiyama which is located in the eastern part of Fukushima Prefecture, Northeast Japan. These basalts (Nodegamiyama basalts) occur as a dome, with a diameter of about 300 meters, which intrude into Cretaceous granitic rocks occupying in Abukuma mountainland.
    Nodegamiyama basalts are sparsely phyric (phenocrysts of olivine with chrome-spinel inclusions, clinopyroxene, orthopyroxene and plagioclase 10 vol%>). These basalts are characterized by relatively high SiO2 (52.0-52.7 wt%), high MgO (8.0-9.3 wt%), relatively low CaO (8.7-9.1 wt%), high Ni (167-220ppm) and high Cr (540-690ppm). The clinopyroxene phenocrysts contain considerable amounts of Al2O3 (3.8-8.0 wt%), and the calculated Ca-Tschermak's component ranges from 7.5 to 13.6 mol per cent, which suggest that these clinopyroxene phenocrysts are thought to have crystallized from the basalt magma at a depth of about 30km in the lower crust in this region.
    Differences in bulk chemical compositions between Nodegamiyama basalts and Ryozen basalts may be ascribed to differences in the degree of partial melting between these two primary magmas and also in water content in the source mantle peridotites of these two primary magmas.
  • 八島 隆一, 植田 良夫
    岩石鉱物鉱床学会誌
    1980年 75 巻 8 号 279-280
    発行日: 1980/08/05
    公開日: 2008/08/07
    ジャーナル フリー
    K-Ar age is determined on the biotite in the rhyolite from lower member of the Neogene Tertiary. The obtained age of 13.5 m. y. is alightly younger than the expected geological time.
  • 周藤 賢治, 八島 隆一
    岩石鉱物鉱床学会誌
    1974年 69 巻 11 号 373-380
    発行日: 1974/11/05
    公開日: 2008/08/07
    ジャーナル フリー
    Rb and Sr concentrations and Sr isotopic compositions (Sr87/Sr86) have been determined for five basalts, four andesitic basalts, one andesite and one obsidian of the Ryozen formation.
    These eleven volcanic rocks have initial Sr87/Sr86 ratios ranging from 0.7033 to 0.7046. These ratios may be nearly identical among the different rock types.
    The Sr87/Sr86 ratios of the basaltic rocks are slightly higher than those of occeanic ridge tholeiites but very similar to those of tholeiitic basalts from Hawaiian Islands and Type II island arc such as the Izu-Bonin Islands, Mariana Islands, Fiji Islands and New Britain Islands.
    On the other hand, the Sr87/Sr86 ratios of acid members are very resemble to those of acid volcanic rocks from Type II island arc and they also lie in the lower part of the range measured in acid volcanic rocks from Type I island arc such as the Japanese Islands and New Zealand, and from Cenozoic orogenic belt in the United States and Central America.
    The Rb concentrations and K/Rb ratios of basaltic rocks in the Ryozen formation are
    nearly comparable to those of the tholeiitic basalts from Hawaiian Islands and Type II island arc, while the Sr concentrations are close to those of oceanic ridge tholeiites.
    Considering from the results of the present work and previous petrological studies, it may be concluded that the siliceous basaltic and acid volcanic rocks of the lower and upper horizons are derived by fractional crystallization of olivine tholeiitic magma which produces olivine basalts in the middle horizon. An alternatively possibility is that olivine tholeiitic, siliceous basaltic and acid magmas may be derived directly from certain upper mantle material presumably of peridotitic composition, which has Sr87/Sr86 ratios around 0.704.
  • 八島 隆一
    岩石鉱物鉱床学会誌
    1963年 50 巻 4 号 135-141
    発行日: 1963/10/05
    公開日: 2008/08/07
    ジャーナル フリー
    Abstract: The basalts and andesites of the Ryozen formation (Miocene in age) of the northern Abukuma region, northeastern Japan are chemically analyzed. The aphyric basalts of the lower and upper parts of the formation are characterized by high Al2O3 content and their mineralogy and chemistry agree with that of the Kuno's high alumna basalt (Kuno, 1960). On the other hand, the olivine basalts of the middle part are relatively rich in MgO and poor in alkalies and TiO2, thus bear the character of the tholeiitic basalts.
  • 周藤 賢治, 牧野 淳史, 板谷 徹丸, 八島 隆一
    岩鉱
    1992年 87 巻 1 号 20-34
    発行日: 1992/01/05
    公開日: 2008/03/18
    ジャーナル フリー
    K-Ar dating and petrologic description were carried out on the Inase valcanic rocks from eastern part of the Kitakami district of Iwate Prefecture, Northeast Japan. We obtained K-Ar whole rock ages of 15.1±0.4 Ma and 15.5±0.4 Ma for two andesites. The results of the present and previous K-Ar age detamination indicate that the volcanic activities in the Inase district took place in the range of 15.5-13.2 Ma. The chemical compositions of representative 32 andesitic samples were determined by XRF technique. The upper Inase volcanics composed of tholeiitic andesites with SiO2 of 53.61-60.61% have chemical characters similar broadly to those of the Quaternary andesites from the NE Japan arc, whereas the lower Inase ones composed also of tholeiitic andesites with SiO2 of 53.86-55.28% are characterized by high contents of HFS elements such as P, Ti, Nb, Y and Zr, suggesting that the latter are different in chemical compositions from the typical island arc andesites. We estimated the trace element composition of the primary magmas of the lower and upper Inase volcanics using the method of Sakuyama and Nesbitt (1986) and Yoshida and Aoki (1988). The process identification diagram for the primary magma compositions of the Inase volcanics and the Quaternary volcanics in the NE Japan arc and the surrounding areas suggests that the upper Inase primary magma may be derived from the magma source chemically similar to the present sub-continental mantle beneath the NE Japan arc, while the lower Inase primary magma may be derived from the magma source which is more enriched in HFS element contents than the sub-continental mantle.
  • 石坂 恭一, 巽 好幸
    岩石鉱物鉱床学会誌
    1980年 75 巻 1 号 10-13
    発行日: 1980/01/05
    公開日: 2008/08/07
    ジャーナル フリー
    Eleven trace element contents, including seven REE, were preliminary determined for eight samples of the Ryozen volcanic rocks of Miocene age, northeastern part of Fukushima Prefecture. The results revealed that some of the Ryozen volcanic rocks (ol-basalt_??_auol-basalt) are characterized by high Cr contents ranging from 868 to 355 ppm. Thus, Ryozen volcanic rocks make a marked contrast to the Quaternary volcanic (tholeiitic) rocks of the Nasu zone with low Cr contents. The basalts have REE patterns characteristic to “Northeast Japan Type island arc tholeiite” defined by Masuda and Aoki (1978). Relationship between the Ryozen volcanic rocks and the Setouchi volcanics is briefly discussed.
  • 一ノ瀬 丁己, 周藤 賢治, 八島 隆一
    岩石鉱物鉱床学会誌
    1986年 81 巻 9 号 384-391
    発行日: 1986/09/05
    公開日: 2008/08/07
    ジャーナル フリー
    Ultramafic and mafic inclusions, including intermediate ones, up to 3 cm in size found in high magnesian tholeiitic basalts are divided into the following three groups based on the mineral assembalge and texture: 1) poikilitic peridotite and pyroxenite, 2) pyroxenite including webster-ite, clinopyroxenite and orthopyroxenite, and 3) gabbro and diorite. The 1st group consists of euhedral olivine chadacrysts with chrome spinel inclusions, and clinopyroxene and/or orthopyrox-ene oikocrysts. The 2nd one shows equigranular in texture, but the last one does poikilitic and equigranular. Most of them contain interstitial patches composed of plagioclase, magnetite, clinopyroxene and glass. Petrographic features suggest that these inclusions are cumulates derived from the host magma.
  • 岩田 洋世, 大杉 節, 大山 博史, 岡田 学, 大本 貴文, 林 邦幸, 赤城 卓, 海野 義信, 小林 茂治, 醍醐 元正, 高島 隆一, 田村 詔生, 樋口 正人, 宮田 等, 宮野 和政, 村上 明
    日本物理学会講演概要集. 年会
    1993年 48.1 巻
    発行日: 1993/03/16
    公開日: 2018/03/26
    会議録・要旨集 フリー
  • 大本 貴文, 大杉 節, 岩田 洋世, 大山 博史, 岡田 学, 林 邦幸, 赤城 卓, 海野 義信, 小林 茂治, 醍醐 元正, 高島 隆一, 田村 詔生, 樋口 正人, 宮田 等, 宮野 和政, 村上 明, 村松 雅治, 山本 晃永, 山村 和久
    日本物理学会講演概要集. 年会
    1993年 48.1 巻
    発行日: 1993/03/16
    公開日: 2018/03/26
    会議録・要旨集 フリー
  • 一色 直記
    地質学雑誌
    1974年 80 巻 7 号 323-328_2
    発行日: 1974/07/15
    公開日: 2008/04/11
    ジャーナル フリー
  • 福島県山野川および山形県上田沢産のアルマンディン
    加納 博, 八島 隆一
    岩石鉱物鉱床学会誌
    1976年 71 巻 4 号 106-119
    発行日: 1976/04/05
    公開日: 2008/08/07
    ジャーナル フリー
    Recently almandine-rich garnet from rhyolite and dacite has been remarked as a high-pressure mineral directly crystallized from an acid hydrous magma at depth. The mineralogy and genesis of almandine-garnets from Yamanogawa, Fukushima Prefecture and Kamitazawa, Yamagata Prefecture were described and discussed from this viewpoint. The former garnet occurs within a hornblende-dacite and the latter is found from an acid tuff. They are different from metamorphic garnets in the following points. (1) The inclusion is characterized by magmatic accessory minerals such as apatite, zircon, rutile, sphene, pyrite, and either magnetite or ilmenite. (2) The zoning patterns of both garnets show neither normal or reverse type but distinct oscillatory type (Figs. 9-14) which is similar to the zoning pattern of associated plagioclase phenocryst (Fig. 16). One of the most probable explanations of such oscillatory zoning may be a model of magma chamber rising step-by-step from depth which causes the decrease of load pressure and accordingly the repeated change of Mg, Ca and Ti. (3) Though slightly corroded, the garnets exhibit conspicuous euhedral form up to 3mm or more in diameter. (4) The almandine-rich composition is what is characteristic of magmatic or synthetic garnets (Fig. 15). The slightly Ca-rich composition of the Yamanogawa garnet may be corresponding to the bulk composition of host dacite.
    Judging from these features with reference to recent literatures, the both Yamanogawa and Kamitazawa garnets are considered to be of a deep origin under a high pressure. The garnet-bearing calc-alkaline acid magmas may have been generated within the upper mantle or the lowest crust and then risen up to the surface through and along some cites of tectonic disturbance. Such environment may be suggested in the case of the Yamanogawa garnet-bearing dacite which occurs along the Yanagawa-Shirasawa tectonic zone developing between the Green Tuff region and the non-Green Tuff region and composing a part of the Morioka-Shirakawa tectonic line (Fig. 18). As for the Kamitazawa garnet-bearing acid tuff, it seems geologically significant that the rock occurs in an area of widespread acid volcano-plutonic formation including welded tuffs (Fig. 19).
  • 岩田 洋世, 大杉 節, 大山 博史, 大本 貴文, 吉川 満俊, 後藤 公徳, 半田 隆信, 田村 昭生, 畠中 照明, 海野 義信, 氏家 宣彦, 高力 孝, 日出 富士雄, 小林 茂治, 村上 明, 醍醐 元正, 高島 隆一, 樋口 正人, 宮田 等, 宮野 和政
    日本物理学会講演概要集. 年会
    1994年 49.1 巻 28a-W-3
    発行日: 1994/03/16
    公開日: 2018/03/26
    会議録・要旨集 フリー
  • 吉川 満俊, 大杉 節, 岩田 洋世, 大山 博史, 大本 貴文, 後藤 公徳, 半田 隆信, 岩田 康, 田村 詔生, 畠中 照明, 海野 義信, 氏家 宣彦, 高力 孝, 日出 富士雄, 小林 茂治, 村上 明, 醍醐 元正, 高島 隆一, 樋口 正人, 宮田 等, 宮野 和政
    日本物理学会講演概要集. 年会
    1994年 49.1 巻 28a-W-2
    発行日: 1994/03/16
    公開日: 2018/03/26
    会議録・要旨集 フリー
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