著者

Fumiko HIGASHINO Tetsuo KAWAKAMI

出版者

Japan Association of Mineralogical Sciences

雑誌

Journal of Mineralogical and Petrological Sciences (ISSN:13456296)

巻号頁・発行日

vol.117, no.1, pp.220325, 2022 (Released:2022-10-08)

参考文献数

59

被引用文献数

6

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This paper reports the first outcrop occurrence of an ultrahigh–temperature (UHT) metamorphic rock from the Sør Rondane Mountains (SRM), East Antarctica. A pelitic gneiss from Balchenfjella, eastern SRM, contains mesoperthite that gave UHT condition (>900 °C) by ternary feldspar thermometry. The UHT mesoperthite is present both in the matrix and as an inclusion in garnet. The garnet also has nanogranitoid inclusions next to the mesoperthite, which are interpreted to be an UHT melt. The re–integrated nanogranitoid composition is plotted in the primary phase region of quartz and classified as granite. Even crystallized nanogranitoids can provide appropriate original melt composition in the An–Ab–Or and Qz–Ab–Or spaces, whereas Mg concentration is enriched due to local retrograde Fe–Mg exchange reaction between the nanogranitoid inclusions and the host garnet. Although metamorphic rocks in the SRM are highly retrogressed, this study revealed that the microstructural evidence of UHT condition is partially preserved. Further investigation of timing and areal extent of UHT metamorphism helps us to understand the tectonic model of the SRM.

著者

鈴木 重人 伊藤 正裕 杉浦 孜

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.71, no.7, pp.183-192, 1976-07-05 (Released:2008-08-07)

参考文献数

3

被引用文献数

3

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本鉱物は,三波川帯中の各種銅鉱物をともなう蛇紋岩体の割れ目より発見された。細かな針状ないし長柱状をなし,特徴的なsky-blueの色を呈する。構造式(C=1)として, Mn0.019Ni0.231Cu7.770(SO4)3.904(CO3)(OH)6.232・48.4H2O または, (Mn,Ni,Cu)8(SO4)4(CO3)(OH)6・48H2Oをもつ。 本鉱物の光学的性質, X線回折,電子線回折, DTA-TG, IRパターンに見られる諸性質について報告した。また,産状の違いにより, X線回折およびDTAパターンに僅かな違いが見られ,これらについても検討した。 Nakauri, Shinshiro, Aichi Prefecture愛知県新城市中宇利

著者

SATOSHI MATSUBARA KOZO NAGASHIMA

出版者

Japan Association of Mineralogical Sciences

雑誌

Mineralogical Journal (ISSN:05442540)

巻号頁・発行日

vol.7, no.6, pp.513-525, 1975 (Released:2008-03-18)

参考文献数

15

被引用文献数

5 5

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Orthoericssonite, BaMn2+2Fe3+ [O|OH|Si2 O7], hitherto reported only from the Långban mine, Sweden, was found in a jacobsite-bearing rhodonite-aegirine-tephroite ore from the Hijikuzu mine, Iwate Prefecture, as a product of strong thermal metamorphism due to granitic intrusion. It is orthorhombic, space group Pmmn, a0=20.30Å, b0=6.986Å, c0=5.387Å, Z =4. Wet chemical analysis by K. N. gives the empirical formula (Ba0.688Sr0.256K0.024Na0.013Li0.003)0.984(Mn1.4352+Fe0.5462+Mg0.086)2.067(Fe0.9313+Ti0.093Al0.034)1.058Si2.062 O7.000(O1.389(OH)0.611)2.000 as O=9, specifying it as a strontian and ferroan variety. It is optically biaxial positive, 2V about 50°, r ?? v strong, ns α=1.802, β=1.840, γ=1.888; strongly pleochroic, X=yellowish brown, Y=reddish brown, and Z=dark brown.

著者

Takashi YUGUCHI Hideki IWANO Takenori KATO Shuhei SAKATA Kentaro HATTORI Takafumi HIRATA Shigeru SUEOKA Tohru DANHARA Masayuki ISHIBASHI Eiji SASAO Tadao NISHIYAMA

出版者

Japan Association of Mineralogical Sciences

雑誌

Journal of Mineralogical and Petrological Sciences (ISSN:13456296)

巻号頁・発行日

vol.111, no.1, pp.9-34, 2016 (Released:2016-03-07)

参考文献数

86

被引用文献数

17 21

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Zircons collected from a granitic pluton provide evidence of serial growth events with specific mechanisms, crystallization temperatures and U–Pb ages, revealing details of the sequential formation process from intrusion through emplacement to crystallization/solidification. The events have been identified by: 1) the study of the internal structure of zircon using cathodoluminescence, 2) deriving crystallization temperatures using Ti–in–zircon thermometry of the internal structure and 3) U–Pb age dating of the internal structure. The magmatic zircons from the Toki granite, central Japan, show two kinds in their internal structure: a low luminescence core (LLC) and oscillatory zonation (OZ). The LLC was produced by interfacial reaction–controlled growth in the granitic magma with cooling from about 910 to 760 °C. The formation of OZ occurred by diffusion–controlled growth in a cooling magma chamber from about 850 to 690 °C. The U–Pb ages derived from the LLC ranges from 74.7 ± 4.2 to 70.5 ± 1.3 Ma, indicating the incipient intrusion timing of the magma into the shallow crust. The OZ ages distribute from 72.7 ± 0.6 to 70.4 ± 1.7 Ma, which mean the timing from emplacement to crystallization/solidification of the granite pluton. Thus, the serial processes from intrusion through emplacement to crystallization/solidification occurred within a few million years. The old LLC and OZ ages are recognized in the western margins of the Toki granite, implying that the magma forming the western margins was the first to intrude, emplace and crystallize/solidify. The western margins with initial intrusion may accompany the crustal assimilation in order to create sufficient magma reservoir space, which is consistent with larger SrI and ASI values found in the western margins of the granite.

著者

今野 弘

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.69, no.9, pp.324-331, 1974-09-05 (Released:2008-08-07)

参考文献数

20

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Quartz crystals of various geologic origins have been irradiated by Co60 γ-rays so that to elucidate the relation between absorption coefficients and the contents of trace elements, especially of Al, Li and K. The absorption maxima perpendicular to the optic axis are at 480nm for natural smoky quartz, 460nm for artificially coloured smoky quartz. A clear correlation was noticed between absorption coefficients (a2-a1) and Al/Li ratio, suggesting that the colouring of smoky quartz is due to Al-Li defects. It was also noticed that K ion plays a negative role in the colouring. As a general tendency, it was noticed that quartz crystals formed under higher temperature conditions, such as those from pegmatites are more readily coloured than those from epithermal veins.

出版者

Japan Association of Mineralogical Sciences

雑誌

Journal of Mineralogical and Petrological Sciences (ISSN:13456296)

巻号頁・発行日

vol.117, no.1, pp.220525, 2022 (Released:2022-06-28)

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Editorial Message

著者

大場 司

出版者

Japan Association of Mineralogical Sciences

雑誌

岩鉱 (ISSN:09149783)

巻号頁・発行日

vol.86, no.7, pp.305-322, 1991-07-05 (Released:2008-03-18)

参考文献数

16

被引用文献数

3 4

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Geological survey has been carried out on Akita-yakeyama volcano, eastern Akita Prefecture, Japan to establish the evolutional history of the volcano. Furthermore, the volcanic products have been described in detail to contribute to the petrological investigation of the volcano, that is currently in progress. The volcanic activities can be divided into three stages in terms of mode of volcanic activity or characteristics of the erupted products, or both. Approximately 300, 000 years ago, the volcanic activity started within a caldera formed by the eruptions of the voluminous felsic pyroclastics at 1 million years ago. This is the beginning of the early stage; the new volcano erupted number of andesitic lavas of the pigeonitic rock series while pyroclastic flows and falls were less abundant. The shape and size of the volcano built during this stage is not clear since it was covered with the following volcanic products, and severe erosion altered it much. In the middle stage the lava flow activities have been associated by explosive eruptions: pyroclastic falls and flows were repeated from central vent. The alternation of lavas and pyroclastics could have completed a large stratovolcano. All the volcanic rocks during this stage belong to hypersthenic rock series. After middle stage, the activity ceased for a while, and hydrothermal alteration expanded to nearly all over the volcano. Consequently, collapses of the altered piles of lavas and pyroclastics have led to five horseshoe-shaped calderas around the summit. After the repose period, the late stage activity started with explosive central and flank eruptions of pyroclastic fall; lava flows as well as pumice falls followed. During this stage, two andesite lava domes and two dacite domes were constructed. In the central area of the summit crater a dacite dome was built and dacitic ash was erupted; this is the latest activity. All the rocks of the last stage are of the hypersthenic rock series as well.

著者

Tomokazu HOKADA Tatsuro ADACHI Yasuhito OSANAI Nobuhiko NAKANO Sotaro BABA Tsuyoshi TOYOSHIMA

出版者

Japan Association of Mineralogical Sciences

雑誌

Journal of Mineralogical and Petrological Sciences (ISSN:13456296)

巻号頁・発行日

vol.117, no.1, pp.220317, 2022 (Released:2022-08-20)

参考文献数

38

被引用文献数

3

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We have found corundum in direct contact with quartz and biotite and as inclusions in garnet in the pelitic gneisses of northern Austkampane in the Northeastern (NE) Terrane of the Sør Rondane Mountains (SRM), East Antarctica. Our samples, which include corundum–bearing gneisses, show petrographic features such as staurolite inclusions in garnet, compositional zoning of orthoamphibole with Al decreasing toward the rims, and late–stage cordierite formation, and these features are characteristic of a clockwise P–T trajectory. The observations are consistent with the proposed regional clockwise P–T evolution of the NE Terrane in the SRM. The corundum and other inclusions observed in the garnet porphyroblasts are interpreted to have formed owing to either staurolite breakdown or metastable crystallization relative to kyanite prior to the peak metamorphism. The close association of biotite and quartz surrounding corundum inclusions suggests fluid– or melt–related processes. These petrographic features imply that the corundum and quartz (rarely observed in high–grade metamorphic rocks) formed as a result of metastable crystallization during the prograde stage of the clockwise P–T evolution of a continental collision zone.

著者

Shoji ARAI Hisatoshi HIRAI Kozo UTO

出版者

Japan Association of Mineralogical Sciences

雑誌

Journal of Mineralogical and Petrological Sciences (ISSN:13456296)

巻号頁・発行日

vol.95, no.4, pp.9-23, 2000 (Released:2005-12-15)

参考文献数

73

被引用文献数

56 58

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There are a number of Cenozoic ultramafic xenolith localities on the Southwest Japan arc, which enable us to deduce a petrological model of the upper mantle of the island arc or active continental margin on a regional scale. On the basis of mineral chemistry and petrology the mantle peridotites (harzburgite and lherzolite) from the Southwest Japan arc can be divided into two types, unmetasomatized and metasomatized types. The former type of peridotites, which are less predominant than the latter, have characteristics of mantle restite (olivine of Fo88−91) and are not accompanied with Fe-rich black pyroxene-bearing xenoliths and related pyroxene megacrysts. They are found exclusively in isolated monogenetic volcanoes not forming volcano clusters. In contrast, the latter type of peridotites, which are always accompanied with large amounts of Fe-rich black pyroxenite xenoliths and related black pyroxene megacrysts, have less magnesian minerals (e.g., olivine of Fo78−90) depending on the degree of metasomatism. They have textural and modal characteristics as mantle restites but also have chemical characteristics as metasomatites. They are mainly found in monogenetic volcanoes constituting volcano clusters.    The Fe-rich pyroxenites and related rocks are young precipitates of possibly Tertiary ages from alkali basaltic melts, genetically related with the xenolith-carrying basalts. A large scale asthenospheric upwelling in the Miocene time may have been responsible both for the intra-plate alkali basalt magmatism, namely the formation of xenolith-bearing basalts, metasomatism and precipitation of Fe-rich pyroxenites and megacrysts, and for the Japan Sea opening. The formation of Fe-rich pyroxenites and related rocks strongly modified the pre-existing mantle-crust both in chemistry and structure, leaving a chemically and geophysically intermediate Moho transition zone. This may be one of the characteristics of the upper mantle of active continental margin or island arc in the Western Pacific.

著者

Yoshihiro NAKAMURA Koji U. TAKAHASHI Jun HOSOI Hidetoshi HARA

出版者

Japan Association of Mineralogical Sciences

雑誌

Journal of Mineralogical and Petrological Sciences (ISSN:13456296)

巻号頁・発行日

vol.117, no.1, pp.220316, 2022 (Released:2022-08-09)

参考文献数

32

被引用文献数

1

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A new type of compact deep–UV micro–Raman spectroscopy system was developed with a single monochromator, front–illuminated cooled charge–coupled device, and 266 nm nanosecond pulsed laser to overcome laser–induced fluorescence from surrounding minerals and organic material. Deep–UV micro–Raman spectroscopy is particularly useful in analyzing the fluorescence–free Raman spectra of dispersed low–maturity carbonaceous material and coal, although deep–UV excitation lasers may cause serious degradation and laser–induced heating of the sample surface, especially in microanalysis. The laser–induced damage threshold for fully ordered graphite and coal (VRr = ~ 0.5%) was assessed to facilitate the acquisition of accurate Raman spectra with a spot size of ~ 1 µm. For fully ordered graphite, there was no serious degradation of the sample surface with an energy fluence of 0.10–2.50 J cm−2. Some sample surfaces became black at higher fluences of 1.96–2.50 J cm−2, suggesting irreversible damage by deep–UV lasers. The Raman shift of the G band after measurement involves a downshift of 1.7–7.4 cm−1 relative to other spectra obtained at low laser fluences of <0.34 J cm−2. The G band full width at half maximum (FWHM) also increased with increasing laser fluence. Serious degradation of polished coal surfaces occurs at even lower laser fluences of 0.34–2.50 J cm−2. The degree of change in Raman parameters such as the D and G band FWHM depends on the laser fluence during measurements. Heating and damage by a deep–UV laser is greater than that by visible lasers. Laser fluences of <0.16 and 0.34 J cm−2 are required for accurate Raman analyses of dispersed carbonaceous material in sedimentary rocks and fully ordered graphite in metasediment, respectively.

著者

Yuichiro MORI Hiroyuki KAGI Sho KAKIZAWA Kazuki KOMATSU Chikara SHITO Riko IIZUKA–OKU Katsutoshi AOKI Takanori HATTORI Asami SANO–FURUKAWA Ken–ichi FUNAKOSHI Hirouyki SAITOH

出版者

Japan Association of Mineralogical Sciences

雑誌

Journal of Mineralogical and Petrological Sciences (ISSN:13456296)

巻号頁・発行日

pp.210825, (Released:2022-03-02)

被引用文献数

1

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The Earth’s core is believed to contain some light elements because it is 10% less dense than pure Fe under the corresponding pressure and temperature conditions. Hydrogen, a promising candidate among light elements, has phase relations and physical properties that have been investigated mainly for the Fe–H system. This study specifically examined an Fe–Si–H system using in–situ neutron diffraction experiments to investigate the site occupancy of deuterium of hcp–Fe0.95Si0.05 hydride at 14.7 GPa and 800 K. To date, this pressure condition is the highest for neutron diffraction experiments conducted at high pressure and high temperature, where crystal structure analysis has been conducted. Results of Rietveld refinement indicate hcp–Fe0.95Si0.05 hydride as having deuterium (D) occupancy of 0.24(2) exclusively at the interstitial octahedral site in the hcp lattice. The effect on the site occupancy of D by addition of 2.6 wt% Si into Fe (Fe0.95Si0.05) was negligible compared to results obtained from an earlier study of an Fe–D system (Machida et al., 2019).

著者

Akio SUZUKI

出版者

Japan Association of Mineralogical Sciences

雑誌

Journal of Mineralogical and Petrological Sciences (ISSN:13456296)

巻号頁・発行日

vol.117, no.1, pp.211215, 2022 (Released:2022-05-20)

参考文献数

21

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To determine the phase boundary between diaspore (α–AlOOH) and δ–AlOOH, in situ X–ray diffraction experiments were carried out using a multi–anvil high–pressure apparatus and synchrotron X–ray. The stability of each phase was determined by observing the change in powder X–ray diffraction patterns. The equilibrium phase boundary is described by the formula P (GPa) = 12.2 (±4.9) + 0.0027 (±0.0044) × T (K). The boundary determined in this study is located at a lower pressure than that estimated by previous quenching experimental studies.

著者

赤井 純治 大藤 弘明 松本 嘉文

出版者

Japan Association of Mineralogical Sciences

雑誌

日本鉱物学会年会講演要旨集

巻号頁・発行日

pp.148, 2005 (Released:2006-09-08)

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炭素質コンドライトのマトリックスは微小な鉱物の集合体で、マトリックス鉱物はフィロシリケート・PCP・硫化鉱物・酸化鉱物・炭酸塩鉱物・硫酸塩鉱物・炭素鉱物・等が含まれる。これらの鉱物種、結晶形態・集合状態・組織は、それら鉱物あるいは隕石自体の生成に関する重要な情報を示唆していることが考えられる。構成鉱物のなかには多くの特徴的あるいは特異な鉱物も含まれるが、生成条件等明確になっていないものも多い。その詳細は電顕鉱物学の視点からの解明されるところも大きい。磁鉄鉱についてはこれまでにもJedwab(1968), Kerrige(1979)、Hua et al., (1998)などが主にSEMによって 記載している.磁鉄鉱には次の種がある。a)よく結晶面が発達した単結晶磁鉄鉱, それらのフランボイド状の集合体、 b)特異な板状(platelets)の形態の積み重なりをもつ磁鉄鉱(plaquettes:Jedwab,1968),c) 球顆状構造をもつ球状晶が,主にみられる.この他に単独でより大きな単結晶のものもあるとされている(Jedwab,1968). それらがどういう条件で生成したのか、生成の場の違いはあるのか、生成の順序はどうか、等成因にからんだ問題がある。今回、とくにフランボイダル形態の磁鉄鉱を中心に検討し、さらに他の2つについても検討した。フランボイド集合は、自己組織化の構造として注目される。地球表層環境中のパイライトではとくに 20面体構造のものを見いだしている(Ohfuji and Akai,2002). 20面体構造を形成する基礎には、マイクロクリスタルのccp、hcpなどの規則配列構造がある。これに対し、ランダムタイプもある。またサイズ的にはフランボイド粒直径とマイクロクリスタルサイズの比も指標となり、核形成条件のちがいが議論される。つまり、これらの生成条件が隕石中のフランボイダル磁鉄鉱の生成条件にかかわって、条件推定に役立つことも期待できる。試料は炭素質コンドライト,Ivuna, Orgueil , Tagish Lakeの三試料を用い、その中の磁鉄鉱に着目して,透過電顕及び走査電顕で観察した.Ivuna 、Orgeil ではあまり大きな違いがみられない。フランボイドを構成するマイクロクリスタルのサイズは、0.2_から_1μm程度の幅がある場合と、そのサイズが揃っている場合とがある。このうち、今回Orgueil から、規則構造が見いだされた。マイクロクリスタルはサイズが約0.5μmで、全体の形態はフランボイド状である。マイクロクリスタルが、直線的に配列し、その間に最密充填状に次列がならぶという、パッキング様式を示す。最密充填構造によるフランボイダルパイライトと同様な組織をもつものが存在する可能性が高い。また、別のグレインで、磁鉄鉱外周に,蛇紋石構造のフィロシリケートがおおうこともある。磁鉄鉱には、ランボイド、plaquettes、球晶の3種が含まれ,このことは3つのことなった生成時期があったこと,または3種の起源の多少ことなった物質の混合,があると考えられ、また結晶面のよく発達したタイプの磁鉄鉱の生成にひきつづいて,フィロシリケートがこれを覆うように成長付加したということを示しており,原始太陽系星雲内での生成プロセス,また炭素質コンドライト母天体上プロセスでの制約条件をあたえている.さらに、生成順、生成のメカニズムについても議論する。

著者

Toshio NOZAKA Daisuke MIYAMOTO

出版者

Japan Association of Mineralogical Sciences

雑誌

Journal of Mineralogical and Petrological Sciences (ISSN:13456296)

巻号頁・発行日

vol.116, no.6, pp.314-319, 2021 (Released:2022-03-24)

参考文献数

25

被引用文献数

1

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Compositional variations of talc in peridotites and serpentinites could have significant implications for modeling of geochemical cycles involving the upper mantle but have been scarcely studied. We analyzed chemical compositions of prograde and retrograde talc and associated minerals in thermally metamorphosed serpentinites from Southwest Japan. The analyzed talc has variations of Si, Al, Mg, Fe, and Na contents. Most of the Si, Al, Mg, and Fe variations indicate mechanical mixing with serpentine and chlorite at a submicroscopic scale. Spatial distribution of talc–chlorite mixtures suggests their prograde metamorphic origin. Talc–serpentine mixtures could be formed by retrograde decomposition of talc–olivine assemblage and orthopyroxene at conditions of higher temperature and/or higher Si activity than serpentine–brucite mixtures, which are the typical products of serpentinization of olivine. Talc itself, regardless of prograde or retrograde origin, has compositional variations with Na enrichment as a likely result of solid solution or Na–mica mixing. The Na enrichment suggests that talc could be the most capable reservoir of Na in metamorphosed peridotites and serpentinites.

著者

Daisuke NISHIO–HAMANE Katsuyuki SAITO

出版者

Japan Association of Mineralogical Sciences

雑誌

Journal of Mineralogical and Petrological Sciences (ISSN:13456296)

巻号頁・発行日

vol.116, no.5, pp.263-271, 2021 (Released:2022-02-03)

参考文献数

35

被引用文献数

2

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Au(Ag)–Sn–Sb–Pb minerals occurring in association with gold, rumoiite (AuSn2), shosanbetsuite (Ag3Sn), yuanjiangite (AuSn), aurostibite (AuSb2), and anyuiite (AuPb2), were found from the Shosanbetsu River (the former three), Shosanbetsu village and the Ainusawa River (the latter two), Haboro town, Rumoi province, Hokkaido, Japan. Rumoiite (IMA No. 2018–161) and shosanbetsuite (IMA No. 2018–162) have been approved as new minerals by the International Mineralogical Association, the Commission on New Minerals, Nomenclature and Classification (IMA–CNMNC) and named after the locality. Both minerals show anhedral shape at less than 5 µm and occur in close association with one another, yuanjiangite, and native lead in spherical aggregates in placer gold. The densities of rumoiite and shosanbetsuite based on their empirical formulae and powder diffraction data were calculated to be 10.1 and 11.1 g/cm3, respectively. The empirical formulae of rumoiite and shosanbetsuite were (Au0.95Ag<0.01)Σ0.96(Sn1.93Sb0.08Pb0.02Bi0.01)Σ2.04 (basis of 3 apfu) and (Ag2.46Au0.54)Σ2.99(Sn0.97Sb0.01Pb0.01Bi0.01)Σ1.01 (basis of 4 apfu), respectively. Rumoiite is orthorhombic, Pbca, with lattice parameters a = 6.9088(7) Å, b = 7.0135(17) Å, c = 11.7979(19) Å and V = 571.6(2) Å3 (Z = 8). Shosanbetsuite is orthorhombic, Pmmn, with lattice parameters a = 5.986(8) Å, b = 4.779(3) Å, c = 5.156(6) Å and V = 147.5(3) Å3 (Z = 2). Rumoiite and shosanbetsuite correspond to the synthetic AuSn2 and Ag3Sn phases, respectively. The chemical compositions for aurostibite, anyuiite, yuanjiangite, and native lead, and the unit cell parameters for yuanjiangite and native lead are also reported in this paper. Hydrothermal activity in ultramafic rocks after the formation of gold (electrum) grains may have been involved in the occurrence of Au(Ag)–Sn–Sb–Pb minerals.

著者

Keitaro OKAMOTO Takahiro KURIBAYASHI Toshiro NAGASE

出版者

Japan Association of Mineralogical Sciences

雑誌

Journal of Mineralogical and Petrological Sciences (ISSN:13456296)

巻号頁・発行日

vol.116, no.5, pp.251-262, 2021 (Released:2022-02-03)

参考文献数

23

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In situ high–pressure single–crystal X–ray diffraction experiments on natural hemimorphite, ideally Zn4[Si2O7](OH)2·H2O, up to 4.7 GPa were conducted to investigate its pressure response property associated with pressure–induced phase transition. After the phase transition confirmed between 2.46 and 3.01 GPa, pairs of satellite reflections were newly found at certain Bragg reflections. The modulation vector q of the satellites was approximately [0, 1/8.4, 0]. The results of the refinements on the averaged structure indicated that the modulation arose from displacements of atomic sites associated with the mechanism of the phase transition, i.e., the rotation of the secondary building unit (SBU). The lower rotation angle of the SBU (Φ) than the value estimated from the non–modulated structure meant that the high–pressure phase contained anti–phase boundaries (APBs) resulting from the opposite direction of the SBU rotation and that the coherency was held across the APBs. Within the coherent domain, the APB’s intervals were distributed along the b–axis with a mean value of 8.4b ≈ 90 Å, where the displacement of each site η (y ) was approximated as the first–harmonic. The distribution of the direction of SBU rotation was initially considered to be inhomogeneous, but the elimination of the APBs had proceeded anisotropically and had been aborted below 3.01 GPa.

著者

早川 典久

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.36, no.6, pp.169-176, 1952-12-10 (Released:2008-03-18)

参考文献数

4

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Geology and sulphur deposit in Uguisu-zawa Mine, situated in the northwestern district of Hanamaki, Iwate Prefecture, Northaest Japan, are described and some considerations on the ore genesis are mentioned. This sulphur deposit consists of some layered ore seams intercalated in mud stone which were formed in the depression caldera of small scale relating genetically to the “Kuzumaru Volcano” already reported. This sulphur deposit has been believed to be the “Lake Deposit Type” but it is more reasonable to consider that it belongs to the “Flowed Sulphur Type” from theviewpoint of the structural and textural features of the ore seams.

著者

早川 典久

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.36, no.5, pp.135-142, 1952-10-10 (Released:2008-03-18)

参考文献数

4

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1. 葛丸火山の火成活動は,鶯宿岩沢構造線上に生じた陥没地域に,葛丸川上流を中心として行われたもので,葛丸川上流に旧火口を推定することが出来る。 2. 火成活動は第I及び第II期に区分せられ,第I期は石英安山岩活動,第II期は含石英両輝石安山岩活動に屬し,夫々葛根田火山のk1(石英安山岩)及びk2(含石英安即岩)に相当し,葛根田火山に於けると同様に噴出物の性質は酸性より塩基性に向う傾向を示す。 3. 第I期の石英安山岩活動は更にIa~Ieの5期に細分され,各活動期の中間には休止期が存在する。休止期には陥没湖沼中に凝灰質泥岩層乃至砂礫層を沈積する。 4. 陥没湖沼はIa期よりId期初頭迄は存在したことが考えられるが,Id期中に全体が陸化し, Id期と1e期の間の休止期には局部的な,小陥波が起つて,硫黄鉱床が生成されている。 5. 第I期石英安山岩活動の噴出物の性質は葛丸火山全体を通じて示される傾向と同様に酸性から塩基性に向う性質を示す。

著者

Shoichi KOBAYASHI Hiroshi MIYAKE Tetsuya SHOJI

出版者

Japan Association of Mineralogical Sciences

雑誌

Mineralogical Journal (ISSN:05442540)

巻号頁・発行日

vol.13, no.6, pp.314-327, 1987 (Released:2007-03-31)

参考文献数

19

被引用文献数

14 16

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A jadeite rock from Oosa-cho, northern part of Okayama, is associated with serpentinite of the Sangun metamorphic belt. It consists predominantly of jadeite with such accessary minerals as grossular, analcime, prehnite, vesuvianite, natrolite, thomsonite, stronalsite, zircon, deweylite, chlorite and diopside. It is cut by many veinlets composed of one or more of grossular, analcime, vesuvianite, stronalsite, chlorite and zeolite minerals.On the electron microprobe image, some of jadeite crystals show a growth zoning of diopsidic (Jd96Di3Fs1) and pure (approximately Jd100) parts. Some crystals of garnet show chemical zoning. The core is poor in TiO2, FeO and CaO, but rich in Al2O3 as compared with the rim. Zircon occurs sporadically. Under the microscope, a few grains of stronalsite are observed. Its chemical composition is very similar to the ideal formula, Na2SrAl4Si4016. Ba-rich parts are also recognized in a stronalsite crystal.

著者

KAZUNOSUKE MASUTOMI KOZO NAGASHIMA AKIRA KATO

出版者

Japan Association of Mineralogical Sciences

雑誌

Mineralogical Journal (ISSN:05442540)

巻号頁・発行日

vol.3, no.3, pp.139-147, 1961 (Released:2008-03-18)

参考文献数

12

被引用文献数

1 2

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A black prismatic kobeitc-like mineral from a granite pegmatite of the Ushio mine in Ômiya town, Kyoto Prefecture and the kobeite from the original locality have been studied. Both the chemical analyses and the X-ray powder patterns of heated materials of the two minerals gave the concordant results. The two minerals contain notable amount of zirconium and after heat treatment give X-ray patterns similar to those of stabilized cubic zirconia. Kobeite will not be a member of the euxenite-polycrase series but may be a distinct mineral species of multiple oxide containing Y, Fe, U, Ti, Zr and Nb as the main components.