Abstracts for Annual Meeting of Japan Association of Mineralogical Sciences
2011 Joint Annual Meeting of Japan Association of Mineralogical Sciences and The Geological Society of Japan
Displaying 101-150 of 265 articles from this issue
T7: Rocks and mineral resources of Mongolia and Northeast Asia
  • M. Satish-Kumar, Y. Osanai, N. Nakano, A. Kamei, S. Jargalan, C. Boldb ...
    Session ID: T7-P04
    Published: 2011
    Released on J-STAGE: March 28, 2012
    CONFERENCE PROCEEDINGS FREE ACCESS
    Mineralization in tectonically active orogenic belts is basically controlled by the movement and activity of fluids. Central Asian Orogenic Belt (CAOB) is a fertile region for mineralization because it consists of several subduction and accretion related metamorphic and magmatic complexes formed between 1000 Ma and 250 Ma, where fluid-rock interaction processes are expected. We present here preliminary data on the carbon and oxygen stable isotopic composition as well as strontium isotope and trace element characteristics of metacarbonate rocks from the several localities in the CAOB. Metacarbonate rocks occur as relatively thin layers intercalated with pelitic and psammitic gneisses, which can be broadly grouped into two categories based on carbon and oxygen isotopic composition. (1) Metacarbonate rocks that preserve pre-metamorphic stable isotope signatures, and (2) those affected by fluid-rock interaction processes during metamorphism and mineralization events. In our presentation, we compare and contrast the geochemical characteristics in mineralized and non-mineralized layers of metacarbonate rocks from selected localities in western Mongolia.
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  • Oyun-Erdene Zorigtkhuu, Toshiaki Tsunogae, Batulzii Dash
    Session ID: T7-P05
    Published: 2011
    Released on J-STAGE: March 28, 2012
    CONFERENCE PROCEEDINGS FREE ACCESS
    The Altai Orogen in the southwestern margin of the Central Asian Orogenic Belt contains various volcano-sedimentary rocks that were deformed and metamorphosed under various P-T conditions Geothermobarometric and mineral equilibrium modelling studies on the rocks obtained peak P-T condition of 640-690C /6.3-10.7 kbar and clockwise path from the area. Such high-pressure amphibolite-facies event is related to the activity of CO2-rich fluid.
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  • Limin Zhao, Akira Takasu, Yongjiang Liu, Weimin Li
    Session ID: T7-P06
    Published: 2011
    Released on J-STAGE: March 28, 2012
    CONFERENCE PROCEEDINGS FREE ACCESS
    The blueschists and the related metamophic rocks along the Tayuan-Xiguitu fault, between the Ergun block and the Xing`an block have been found since 1990s. Recent our field work survey revealed that the blusechists occur with basic schists, pelitic schists and siliceous schists. The blueschists consist mainly of chlorite, epidote, amphibole, the peak metamorphic stage: epidote-blueschists facies is characterized by the sodic-amphibole, epidote, albite, phengite and hematite. The basic schists consist mainly of amphibole, epidote, plagioclase and clinopyroxene. The constituent minerals (Hbl + Pl + Ep + Qtz +Cpx) are stable at the peak metamorphic stage of epidote-amphibolite facies.
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  • Daisuke Hyodo, Masaaki Owada
    Session ID: T7-P07
    Published: 2011
    Released on J-STAGE: March 28, 2012
    CONFERENCE PROCEEDINGS FREE ACCESS
    The Sangun-Renge belt (Sangun belt) is well known as the high-pressure type metamorphic belt. Here we report pelitic gneisses from both areas and discuss the implications for the pelitic gneisses from the Sasaguri and Iiduka areas, the Sangun belt. In the Sasaguri area the pelitic gneisses are composed mainly of quartz, plagioclace, muscovite and biotite with a minor amount of garnet. The pelitic gneisses from the Iiduka area comprise quartz, plagioclace, biotite with locally including andalusite, silimanite (fibrolite) and cordierite. Fibrolites and cordierites surround the corroded andalusite and form foliations together with biotites. Judging from mineral textures, the pelitic gneiss from the Iiduka area would, therefore, be suffered by regional metamorphism with low-P/high-T type.
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  • Takahiro Midorikawa, Masaaki Owada
    Session ID: T7-P08
    Published: 2011
    Released on J-STAGE: March 28, 2012
    CONFERENCE PROCEEDINGS FREE ACCESS
    The western part of Yamaguchi prefecture is dominated by the unmetamorphosed Kuga group in the north and the low-grade part of Ryoke belt in the south. The Kuga group conformably overlays the Ryoke belt without any structural gaps. According to the degree of graphitization, the metamorphic grade progressively increases from the Kuga group to the Ryoke belt regardless of any deformational features. The Kuga group was formed as the accretionary complex followed by undergoing the low-pressure type of the Ryoke metamorphism. Therefore, the main deformational events occurred to be prior to the Ryoke metamorphism. Therefore, the eastern part of Yamaguchi Prefecture is one of important region to understand the process from accretionary complex to volcanic arc crust.
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T8: A Moho Sketch: What we expect to obtain through ultra-deep drilling in ocean?
  • Natsue Abe, Benoit Ildefonse, Damon Teagle, IODP Exp. 335 Scientific P ...
    Session ID: T8-01
    Published: 2011
    Released on J-STAGE: March 28, 2012
    CONFERENCE PROCEEDINGS FREE ACCESS
    The MoHole Project, drilling into an intact portion of oceanic lithosphere through the crust to the Moho discontinuity and the uppermost mantle, is a long-standing goal of scientific ocean drilling. Three candidates of the MoHole drilling are decided on thoroughly taking into account the scientific objectives, feasible technology developments and the operation condition of the drill ship during two international workshops held in 2010. A drilling expedition into the oceanic lower crust was carried out during IODP Expedition 335 -Superfast Spreading Rate Crust 4- at one of the three site candidates, ODP Site 1256 (Hole 1256D). It was the fourth scientific drilling cruise, following ODP Leg 206, IODP Exp. 309 and Exp. 312, of the Superfast Spreading Crust campaign to ODP Hole 1256D. The MoHole project remains critical to answer many fundamental questions about the dynamics of the Earth and global elemental cycles.
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  • Masako Tominaga, Natsue Abe
    Session ID: T8-02
    Published: 2011
    Released on J-STAGE: March 28, 2012
    CONFERENCE PROCEEDINGS FREE ACCESS
    As an effective alternative to the coring, which is suffered from typical low-recovery rates in oceanic basement drilling including Mohole project, we hereby suggest to fully utilize downhole physical property logging to investigate in situ lithology. We also suggest that current logging tools/techniques should be properly implemented to meet the temperature requirement in such a deep drilling effort.
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  • Hiroyuki Kimura, Katsuyoshi Michibayashi
    Session ID: T8-03
    Published: 2011
    Released on J-STAGE: March 28, 2012
    CONFERENCE PROCEEDINGS FREE ACCESS
    The temperature ranges of growth of archaea are strongly correlated with the guanine-plus-cytosine (G+C) contents of their 16S rRNA sequences. In order to estimate growth temperatures of uncultured archaea based on G+C content, the 16S rRNA sequences of archaeal species were collected from public databases. These values of growth temperature were plotted against G+C content of 16S rRNA, and then the regression line for estimating growth temperature was calculated. Growth temperatures of subsurface archaea are inferred from G+C content of the 16S rRNA gene sequences by the regression line. In future, growth temperatures of uncultured archaea and in situ subsurface temperatures will be roughly inferred from 16S rRNA sequences of archaea. This new method may be applicable to temperature estimation of subsurface environments for which it has been difficult to measure the actual temperature.
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  • Yoshio TAKAHASHI
    Session ID: T8-04
    Published: 2011
    Released on J-STAGE: March 28, 2012
    CONFERENCE PROCEEDINGS FREE ACCESS
    The author is a geochemist mainly studying chemical processes in material cycle and environmental problems via water and atmosphere. Recently, the author has some relevance with deep sea biosphere and hydrothermal chemistry at sea floor. At presentation, I would like to express my expectations in deep sea drilling project. Main targets in this presentation are water, atmosphere, bacteria, and grain boundary using advanced techniques such as XAFS, PEEM, and STXM, which will allow us to clarify elemental chemical processes occurring in mantle.
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  • Shoji Arai
    Session ID: T8-05
    Published: 2011
    Released on J-STAGE: March 28, 2012
    CONFERENCE PROCEEDINGS FREE ACCESS
    Moho can be petrologically imaged for the Japan arcs and the ocean floor through xenoliths, and drilled or dredged rocks from the current ocean floor and ophiolites, respectively. Beneath the NE Japan arc, the lower crust composed of amphibolites and granulites grades downward to the upper mantle through pyroxene-hornblende rocks (= Moho transition zone; MTZ). Beneath the SW Japan arc, the granulitic lower crust grades downward to the peridotitic upper mantle through spinel websterites (= MTZ). This structure has been modified by young cumulates to various degrees. The sub-oceanic uppermost mantle, mainly composed of harzburgite, grades upward to the layered gabbro (= lower crust) through MTZ composed of dunite + wehrlite + gabbro bands. The sub-oceanic structure has been possibly modified by so-called late-intrusive rocks.
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  • Akira Ishiwatari
    Session ID: T8-06
    Published: 2011
    Released on J-STAGE: March 28, 2012
    CONFERENCE PROCEEDINGS FREE ACCESS
    On-land ophiolites (crust-mantle fragment of a fore-arc lithosphere) and high-pressure metamorphic belts (deeply subducted and later up-heaved accretionary complex) are comparable in size to the aftershock focal areas of M9.0 mega-earthquakes such as 2011 Tohoku Earthquake in Japan, and are exposed as continuous geological bodies bounded by thrust faults. The association of ophiolites and high-pressure metamorphic belts are reported not only from on-land orogenic belts but also from sea floor of the Izu-Mariana fore-arc at a current subduction zone. The 2011 Tohoku Earthquake (M9.0) caused more than 25 m thrust movement along the fault that extends from the trench to more than 100 km depth. If the up-thrust movement like this repeatedly happens every 1,000 years, then the high-pressure metamorphic rocks may be transported to the surface within 4 million years. The wide exposures of 4 Ma ophiolite and high-pressure metamorphic rocks are actually reported from Indonesia. These geological facts suggest that the up-thrusting movement of the ophiolites and high-pressure metamorphic rock may be the geological actuality of the mega-earthquakes in subduction zones.
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  • Shuichi Kodaia, Gou Fujie, Mikiya Yamashita
    Session ID: T8-07
    Published: 2011
    Released on J-STAGE: March 28, 2012
    CONFERENCE PROCEEDINGS FREE ACCESS
    Based on recent seismic studies in the northwestern Pacific lithosphere, the oceanic lithosphere is characterized by 1) seismic velocity reductions towards the trench, 2)high velocity and strong anisotropy uppermost mantle, 3)ridge-wards dipping reflectors immediately above the high velocity mantle. The character 1) is interpreted to be caused of hydration and/or serpentinization during subduction. 2) and 3) are interpreted to represent a formation process of the oceanic lithosphere at the trench. At this moment, we have been presenting a conceptual model showing that a high velocity mantle flow creats strong anisotropy, and that this flow may drag the base of the curst resulting Riedal shear in the lower crust.
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  • Ikuo Katayama, Shintaro Azuma, Junichi Muto
    Session ID: T8-08
    Published: 2011
    Released on J-STAGE: March 28, 2012
    CONFERENCE PROCEEDINGS FREE ACCESS
    Rheological contrast of the oceanic Moho was tested using a latest data of rheological properties of crust and mantle materials.
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  • MASAHIRO ISHIKAWA, SATOSHI SHIBATA, RYUNOSUKE AKIZUKI, KENTA KANEKO, T ...
    Session ID: T8-09
    Published: 2011
    Released on J-STAGE: March 28, 2012
    CONFERENCE PROCEEDINGS FREE ACCESS
    Seismic velocity calculations on rock samples from the Oman ophiolite, coupled with geologic cross sections, provide the basis for seismic reflectivity for various types of Moho transition zones. Results from the crust-mantle sections indicate that lithologic heterogeneity of the lower crust and the Moho transition zones control seismic velocity and seismic reflection characteristics.
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  • Yoshio Kono, Changyong Park, Guoyin Shen, Tatsuya Sakamaki, Tony Yu, Y ...
    Session ID: T8-10
    Published: 2011
    Released on J-STAGE: March 28, 2012
    CONFERENCE PROCEEDINGS FREE ACCESS
    We recently developed combined ultrasonic and X-ray microtomography meaurement in Paris-Edinburgh press, which would greatly contribute to understand effect of rock texture on elastic wave velocities. Here I would like to introduce recent development for ultrasonic measurement in Paris-Edinburgh press and its future applications.
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  • Akio Fujimura, Satoshi Tanaka, Hiroaki Siraisi, Naoki Kobayashi, Hajim ...
    Session ID: T8-11
    Published: 2011
    Released on J-STAGE: March 28, 2012
    CONFERENCE PROCEEDINGS FREE ACCESS
    Penetrator probe of JAXA for planetary exploration was developed sucessfully in 2010, and was confirmed by twice QT tests. Apply to the terrestrial use is easy, and various instruments can be installed in a penetrator probe, because of the more mild environmental conditions. The onboard instruments of penetrator are protected by surface-body and potting fabrics, and water proof character of the penetrator can be realized by these. The penetrator probe possesses own electric power of super lithium battery, and acts as an independent passive observation station. The porbe can be operated as a active device, such as seismic source. The probes would obtain several new information when they are operated as network stations. If penetrator probes can be deployed in a bore hole, several active and/or passive information along the depth will be obtained.
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  • Kiyoshi Baba, Alan Chave, Rob Evans, Pascal Tarits, Greg Hirth, Randal ...
    Session ID: T8-12
    Published: 2011
    Released on J-STAGE: March 28, 2012
    CONFERENCE PROCEEDINGS FREE ACCESS
    The electrical structures of the upper mantle beneath the East Pacific Rise (EPR) at 17˚S and 15˚45'S are imaged by inverting seafloor magnetotelluric data obtained during the Mantle ELectromagnetic and Tomography (MELT) experiment. In most inversions of the data in the 17˚S array, a vertically aligned sheet-like conductor at the ridge crest is especially prominent in the vertical conductivity. Its presence suggests that the melt is more highly concentrated and connected in the vertical direction immediately beneath the rise axis. On the other hand, the model shows no evidence for a conductive region immediately beneath the ridge at 15˚45'S, in contrast to the model obtained beneath the ridge at 17˚S. This result indicates either that the melting process is episodic and currently at a nadir or that melt at 15˚45'S is poorly interconnected.
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  • Katsuyoshi Michibayashi, Yumiko Harigane, Yasuhiko Ohara
    Session ID: T8-P01
    Published: 2011
    Released on J-STAGE: March 28, 2012
    CONFERENCE PROCEEDINGS FREE ACCESS
    We calculated the variation of the seismic properties with two ideal mineral compositions: plagioclase 50% + clinopyroxene 50% (pl50cpx50) and plagioclase 50% and amphibole 50% (pl50amp50). These two compositions could explain a P-wave velocity model for the Godzilla megamullion from 6 km/s for pl50amp50 to 7 km/s for pl50cpx50, suggesting that this oceanic crust may be significantly hydrated.
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  • Tomoaki Morishita, Kenichiro Tani, Eric Hellebrand
    Session ID: T8-P02
    Published: 2011
    Released on J-STAGE: March 28, 2012
    CONFERENCE PROCEEDINGS FREE ACCESS
    We reviewed recent works on ocean floor peridotites and discussed about the oceanic uppermost mantle materials.
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  • Betchaida Duetes Payot, Shoji Arai, Rodolfo Jr. Tamayo
    Session ID: T8-P03
    Published: 2011
    Released on J-STAGE: March 28, 2012
    CONFERENCE PROCEEDINGS FREE ACCESS
    In this work, we aim to have a better understanding of the genesis of podiform chromitites by carefully classifying and comparing the concordant and discordant podiform chromitite types in the Acoje and Coto blocks of the Zambales Ophiolite Complex, Philippines. Our recent fieldwork revealed that the Acoje block solely contains concordant podiform chromitites whereas only discordant chromitites were observed in the Coto block. PGE data obtained using Ni-sulfide fire assay revealed that the high Cr podiform chromitites of the Acoje block have significantly higher PGE contents compared to the Coto block. Based on our initial results, we expect to find further petrological and geochemical differences between these two contrasting podiform types which may help elucidate the possible origin of podiform chromitites.
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  • Hironori Negishi, Shoji Arai, Akihiro Tamura, Satoko Ishimaru
    Session ID: T8-P04
    Published: 2011
    Released on J-STAGE: March 28, 2012
    CONFERENCE PROCEEDINGS FREE ACCESS
    We found a sulfide-rich dunite from Wadi Thuqbah, the northern Oman ophiolite which is within the Moho transition zone. The dunite contains about 2 mode % magnetite-sulfides composite grains. The composite grains are composed of Pentlandite-pyrrhotite intergrowth (PPI), magnetite (Mt) and homogeneous pyrrhotite (HP). PPI shows complicated exsolutions of pentlandite and pyrrhotite, and is cut by Mt. The texture of PPI was formed by decomposition of MSS at low temperatures. Mt has not been added to chromian spinel grains, deny a possibility of later addition of Mt to sulfide composite grains. The magnetite-sulfide composite grains were possibly formed by solidification of separated sulfide-magnetite melt, the Mt has filled cracks of sulfide parts that suffered from brittle deformation.
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  • Shohei Takano, Shoji Arai, Akihiro Tamura
    Session ID: T8-P05
    Published: 2011
    Released on J-STAGE: March 28, 2012
    CONFERENCE PROCEEDINGS FREE ACCESS
    We found discordant dunites from the mantle section of the Lizard ophiolite. They are strongly serpentinized, but we could find rare relic olivine only in some dunites. Two-phase(black and dark green portions) spinel grains are ubiquitous in the dunites. The black portion is rich in Fe3+ and Ti, and the dark green portion is low in Cr#, Fe3+, and Ti. The Fo content(82 to 85) of olivine in the discordant dunites is lower than that of mantle peridotites(89 to 92). The discordant dunites were formed by interaction between the mantle peridotite, and a melt rich in Fe, Ti and olivine components such as ferropicrite. The interaction enhanced the Ti and Fe3+ contents of the magma to precipitate the Ti- and Fe3+-rich spinels that have been decomposed into two phases on cooling.
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  • Makoto Miura, Shoji Arai, Masayuki Okuno, Tomoyuki Mizukami, Hassan Ah ...
    Session ID: T8-P06
    Published: 2011
    Released on J-STAGE: March 28, 2012
    CONFERENCE PROCEEDINGS FREE ACCESS
    Micro-inclusions in chromian spinel of concordant and discordant chromitites from the northern Oman ophiolite (Wadi Hilti) were examined to understand the origin(s) of chromitites. There are two kinds of micro-inclusions; (1)Needle-like exsolution lamellae mainly consist of diopside and enstatite, and (2)globular inclusions composed of enstatite, pargasite and Na-phlogopite. The latter inclusions are contained in both chromitites, but the former inclusions are contained only in the concordant chromitites. Spinels of UHP chromitites from Luobusa ophiolite (Tibet) are completely free from globular inclusions. The globular inclusions mainly composed of pargasite indicate shallow origins, and the exsolution lamellae suggest subsolidus exsolution of silicate components from spinel during cooling of the concordant chromitite. On the other hand, the UHP chromitite is obviously distinct in origin from the Hilti chromitites from Oman.
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R1: Characterization and description of minerals
  • Masahide Akasaka, Sakura Takahashi
    Session ID: R1-01
    Published: 2011
    Released on J-STAGE: March 28, 2012
    CONFERENCE PROCEEDINGS FREE ACCESS
    Obayashi mine in Ohnan-cho, Shimane Prefecture, was operated as silver mine since 1601, and closed in 1966. In this study, we investigated source minerals of silver in Obayashi mine. Obayashi mine is a vein-type deposit occurring in rhyolite-dacite lavas, pyroclastic rocks, tuffaceous sandstone and shale of Cretaceous in age. Major ore minerals are pyrite and arsenopyrite, and the associated minerals are sphalerite, galena, chalcopyrite, pyrrhotite and marcasite. Euhedral to subhedral pyrite and euhedral arsenopyrite contain droplet-like galena, chalcopyrite and pyrrhotite. Crystallization sequence of euhedral pyrite (pyrite I) -> galena+chalcopyrite -> pyrite (pyrite II) -> arsenopyrite+galena is also observed. Some sphalerite grains have chalcopyrite disease. Very minute silver minerals (less than 1 μm), such as native silver, argentite, electrum, unidentified Ag2SbS2 and Cu-Ag-Sb-S phases, occur in pyrite and sphalerite grains.
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  • TAKASHI ISHIBASHI, NORIMASA SHIMOBAYASHI
    Session ID: R1-02
    Published: 2011
    Released on J-STAGE: March 28, 2012
    CONFERENCE PROCEEDINGS FREE ACCESS
    Sideronatrite Na2Fe(SO4)2(OH)-3H2O was found on marcasite - pyrite - bearing quartz vein from the Tako coast, Kusimoto, Wakayama Prefecture, Japan. EPMA analyses (WDX mode) leads the empirical formula, (Na1.54, K0.00)1.54(Fe3+1.04, Al0.01)1.05 (SO4)2.02(OH)0.65 - 3.25H2O.
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  • Masahiro Kano, Chiyoko Henmi
    Session ID: R1-03
    Published: 2011
    Released on J-STAGE: March 28, 2012
    CONFERENCE PROCEEDINGS FREE ACCESS
    Sibirskite and parasibirskite are relation of polymorph, and occur by the alteration products of takedite at Fuka, Okayama Prefecture. The synthesis of parasibirskite was reported, but the synthesis of the sibirskite has not been reported. To determine the formation condition of sibirskite and parasibirskite, they were synthesized from natural takedite. As a result, sibirskite and parasibirskite were formed when synthesizing it for 7 days at 1000 atmosphere and 300C and only sibirskite was formed with the synthesis for 14 days in this condition. In the synthesis from the reagent at 1000 atmosphere and 300C, sibirskite was not generated, but it was synthesized by addition of the seed crystal of sibirskite. Powder samples containing sibirskite and parasibirskite were synthesized under the hydrothermal condition. In any condition, the amount of sibirskite were increased during the run duration, and the amount of parasibirskite were decreased. These findings suggest that sibirskite is stable at these range of temperature and pressure, and parasibirskite is unstable though it formed at the first stage of generation.
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  • Hiromi YANO, Miyoshi KIMATA, Takuya ECHIGO, Mihoko HOSHINO, Isao KUSAC ...
    Session ID: R1-04
    Published: 2011
    Released on J-STAGE: March 28, 2012
    CONFERENCE PROCEEDINGS FREE ACCESS
    The high-temperature skarn from the Uenodani outcrop of Kushiro, Tojo-Cho, Hiroshima Prefecture, Japan, was produced and then the cooling process accompanied the contaminated plutonic rock (Kusachi and Henmi, 1990). Research on the elucidation of the production mechanism of the present high-temperature skarn requires more elaborate studies of the contaminated rock. Therefore this study proves that the present contaminated rock includes the relict of nepheline that is partially replaced by thomsonite, natrolite and analcime. Pectolite partially occur in the form of a strip line sandwiched between natrolite and analcime. Production of zeolites from the Uenodani outcrop has never been reported up to now. This finding constitutes substantial evidence for the experience of hydrothermal alteration in addition to high-temperature skarn acting. The contaminated rocks were examined using powder XRD, EPMA and LA-ICP-MS, and micro-Raman spectroscopy and micro-FTIR. From the above results, it is concluded that the present contaminated rock had experienced the process of zeolitization. This alternation process is consistent in aspects of topology and chemistry.
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  • Takashi Yamada, Yoshiaki Shiobara, Toshiyuki Hirama
    Session ID: R1-05
    Published: 2011
    Released on J-STAGE: March 28, 2012
    CONFERENCE PROCEEDINGS FREE ACCESS
    Melanotekite, an orthorhombic, Pb-Fe-sorosilicate;Pb2Fe2[O2|Si2O7], is found associating with willemite(trigonal, nesosilicate;Zn2SiO4) from a quarry at Numata City, Gunma prefecture. Melanotekite occurs as a wedge-shaped crystal or radial aggregates of needles up to 2mm in length in a cavity or in a fissure of host rocks in alteration zone of gabbro. Associating minerals are mainly willemite and quartz. Chemical analyses of melanotekite by EDS show that the atomic ratio of Pb:Fe:Si is nealy equal to 1:1:1 which are compatible with the ideal composition. On melanotekite, principle lines of reflection obtained by a X-ray powder diffraction method (d/I) are, 5.50(75), 5.02(18), 2.94(20), 2.91(45), 2.86(18), 2.73(100), 2.41(30), 1.695(88), 1.609(66), 1.467(17) and lead to lattice parameters; a=6.978, b=10.99, c=10.02(Å). Willemite, containing a small amount of manganese, produces fluorescence and phosphorescence under short-wave UV.
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  • Koichi Momma, Ritsuro Miyawaki, Satoshi Matsubara, Kazumi Yokoyama, Ma ...
    Session ID: R1-06
    Published: 2011
    Released on J-STAGE: March 28, 2012
    CONFERENCE PROCEEDINGS FREE ACCESS
    Melanophlogite is a silica mineral having framework structure with cage-like voids occupied by gas molecules such as CH4, CO2, N2. Melanophlogite has never been found in Japan, even though some cubic-shaped quartz, which are probably psudomorphs after melanophlogite, have been found. Here, we report discovery of melanophlogite from Kisarazu, Chiba Prefecture. It was found in cracks of tuffaceous breccia in the Pleistocene Shimousa Group. It occurs as transparent cubic crystals of sizes up to 0.1 to 0.2 mm. X-ray powder diffraction patterns of the sample measured by Gandolfi camera are consistent with the tetragonal phase of melanophlogite. The lattice parameters refined by the Rietveld analysis are a=26.8357(8)Å, c=13.3690(8)Å.
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  • Toshiro Nagase, Takahiro Kuribayashi
    Session ID: R1-07
    Published: 2011
    Released on J-STAGE: March 28, 2012
    CONFERENCE PROCEEDINGS FREE ACCESS
    To reveal growth process of chalcedony, we observed the textural change from facet quartz crystal to chalcedony by using TEM and OPM. Observed sample is fire chalcedony from Aguascalientres, Mexico. Under OPM, fine growth bands developed at the transition parts from the facet crystal to chalcedony. Straight growth bands, which are parallel to r or m surfaces, change to zig-zag lines within chalcedony. TEM observations show that many Brazil-twin lamellae, dislocations and nano-sized growth bands develop at the transition parts. And also, rounded contrast with 10-100nm size were observed commonly. The rounded contrasts are enhanced by nano-sized inclusions. The nano-sized inclusions cause the defects and decreasing of crystal size.
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  • Daisuke Hamane, Masayuki Ohnishi, Tetsuo Minakawa, Jun-ichi Yamaura, S ...
    Session ID: R1-08
    Published: 2011
    Released on J-STAGE: March 28, 2012
    CONFERENCE PROCEEDINGS FREE ACCESS
    A new Cr-dominant calcic amphibole with NaCa2Mg4CrSi6Al2O22(OH)2 composition from Akaishi mine was named as ehimeite for the locality, Ehime. The mineral data and the name have been approved by the Commission on New Minerals and Mineral Names of the International Mineralogical Association (no. 2011-023). The type specimen is deposited at the National Science Museum, Tokyo, under the registered number NSM-M 41160. Here, we describe a new Cr-dominant member amphibole, ehimeite.
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  • Toshiaki Shimura, Junji Akai, Biljana Lazic, Thomas Armbruster, Masaak ...
    Session ID: R1-09
    Published: 2011
    Released on J-STAGE: March 28, 2012
    CONFERENCE PROCEEDINGS FREE ACCESS
    A new polysome magnesiohögbomite-2N4S was found in the Sør Rondane Mountains, Antarctica. The samples were collected during the geological field survey as the 50th Japanese Antarctic Research Expedition (JARE-50). The högbomite is formed by the sequence NSSNSS. If we use the module numbers n and s, and an exchange parameter "x" (0 ≤ x ≤ 2), a general formula for the högbomite group can be written as: R2+n+2s-x R3+3n+4s+2x R4+n-x O7n+8s (OH)n .
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  • Satoshi Matsubara, Ritsuro Miyawaki, Kazumi Yokoyama, Masako Shigeoka, ...
    Session ID: R1-10
    Published: 2011
    Released on J-STAGE: March 28, 2012
    CONFERENCE PROCEEDINGS FREE ACCESS
    A Mg-analogue of rowlandite-(Y) occurs in a granite pegmatite at Komono, Mie Prefecture, Japan. It is non-metamict, and the seven strongest XRD lines [d in A (I)] are; 4.95(33), 3.64(37), 3.54(38), 3.08(100), 2.68(32), 2.63(28) and 2.09(35).
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  • Mihoko Hoshino, Yasushi Watanabe, Kenzo Sanematsu, Yoshiaki Kon
    Session ID: R1-11
    Published: 2011
    Released on J-STAGE: March 28, 2012
    CONFERENCE PROCEEDINGS FREE ACCESS
    We also focused on a textural and mineralogical study of apatite and allanite to provide new insights into REE mineralizing processes and understand the formation process of Benjamin river deposit. Rock samples from Benjamin River deposit were divided into three types as follows: apatite-augite-magnetite ore, feldspar porphyry and gabbro pegmatite. The whole rock chemical compositions of the samples from Benjamin River show the REE content correlated with Ca and P contents. This abundance suggests that crystallization of apatite affects significantly the enrichment of REE. Total REE content and F/Cl in apatite from apatite-augite-magnetite ore is similar to those from gabbro pegmatite. This result suggests that formation of apatite-augite-magnetite ore from Benjamin River deposit is related to Ca-rich mafic rock such as gabbro pegmatite.
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  • Seiichiro Uehara, Yasuhiro Takai, Yohei Shirose
    Session ID: R1-12
    Published: 2011
    Released on J-STAGE: March 28, 2012
    CONFERENCE PROCEEDINGS FREE ACCESS
    FE-SEM with a superconductor transition edge sensor (TES) microcalorimeter EDS is a new system for chemical analysis in electron microprobe. ULTRA55 FE-SEM with TES was used in this study. Four M line characteristic lines are found, in LaB6 spectrum LaMζ at 638, LaMα, β at 840, LaMγ at 1026 and a weak line (M2N4 transition) at 1110 eV are detected. The spectra of other REE borides were also assigned the same as La M-lines. For quantitative analysis, we could apply a calibration curve method, using standard specimens of known chemical compositions. Linear calibration curves for a plot of P, Ca, La, Pr, and Nd intensity versus each weight percent were obtained. Although, the relation between the intensity of CeMα, β line and weight percent is nonlinear, it will be caused by X-ray absorption and/or fluorescence excitation, or experimental error. Further study is needed for quantitative analysis of rare earth elements minerals.
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  • Yohei Hanada, Mitsuyoshi Kimata, Masahiro Shimizu, Mihoko Hoshino, Tak ...
    Session ID: R1-13
    Published: 2011
    Released on J-STAGE: March 28, 2012
    CONFERENCE PROCEEDINGS FREE ACCESS
    A formula of biotite has been commonly constructed by the procedure described by Foster(1960) and Rimsaite(1970). However, these procedures are not approved considered for H2O content and iron redox state which have never been measured by EMPA. The present work focuses on the means to determine chemical formulas of biotite in detail by using only EMPA data, with reasonable regard to H2O contents and iron redox state, and discusses the crystal chemistry and the genetic significance. The six samples of biotite are used. The present procedure reveals that all biotite formulae have more vacancies at I site and M site than those usual procedure. It is proved by their derived formulae that there is a coupled substitution including vacancies in the examined biotites. Moreover, it is obvious from the formulae that biotites from the Yamanoo contain more Fe3+ contents than those from the Tanakami. Since Fe2+/Fe3+ ratios of biotites increase in granites of magnetite-series, it is suggested that the granitic rock from Yamanoo may belong to a magnetite-series.
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  • Kiyotaka Ishida
    Session ID: R1-14
    Published: 2011
    Released on J-STAGE: March 28, 2012
    CONFERENCE PROCEEDINGS FREE ACCESS
    In the 200-50 cm-1 far-infrared region, four kinds of bands are observed: two octahedral deformation bands coupled with OH deformational vibrations between 200 and 130 cm-1, a tetrahedral torsional band between 175 and 130 cm-1, an interlayer I-Oinner stretching vibration and an I-Oouter stretching vibration. The weak and broad 140 cm-1 band is K-Oinner stretching and the strong and broad 110 cm-1 band is K-Oouter stretchings in muscovite, and the 175 cm-1 broad band is (NH4/ND4)-Oinner stretching and the 140 cm-1 broad and strong band is (NH4/ND4)-Oouter stretchings in tobelite.
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  • Masanori Kurosawa, Ki-Cheol Shin, Kimikazu Sasa, Satoshi Ishii
    Session ID: R1-15
    Published: 2011
    Released on J-STAGE: March 28, 2012
    CONFERENCE PROCEEDINGS FREE ACCESS
    Fluid inclusions in quartz from miarolitic cavities, quartz veins and hydrothermal-ore veins at the typical Miocene granite-plutons in Tsushima and Kofu, Japan, were analyzed by particle-induced X-ray emission (PIXE) to examine chemistries and behaviors of hydrothermal fluids from granite body in island arcs. Most inclusions in the miarolitic cavities from the Kofu granite were aqueous two-phase inclusions, and those from the Tsushima body were polyphase, aqueous two-phase, and vapor-rich inclusions. Transition-metals compositions (Mn, Fe, Cu, Zn, Ge, and Pb) of the initial hydrothermal fluids inferred from inclusions in the miarolitic cavities were several tens to hundreds of parts per million by weight (ppm) for the Kofu granite and several hundreds ppm to several wt.% for the Tsushima granite. The high concentrations of the Tsushima were probably caused by extreme boiling of hydrothermal fluids because of the shallow emplacement level. Transition-metals contents of polyphase inclusions from the ore veins were comparable to those from porphyry cooper deposit in Bingham, tin ore in Mole granite, and quartz -tourmaline-topaz vein in Cornwall granite.
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  • Hiroshi Kitawaki, Makoto Okano, Ahmadjan Abduriyim, Jun Kawano
    Session ID: R1-16
    Published: 2011
    Released on J-STAGE: March 28, 2012
    CONFERENCE PROCEEDINGS FREE ACCESS
    Natural pink diamonds are of great value as gems due to their color and rarity. Since synthetic diamonds grown by both HPHT process and CVD method have recently been seen in the gem market, it is crucial that synthetic diamonds be discriminated with high certainty in order to maintain the value of natural stones in the diamond market. In most of natural pink diamonds, birefringence accompanied by high order interference color is observed, which originates from plastic deformation. HPHT-grown synthetic diamond shows characteristic sector zoning which indicates a combination of {100} and {111} faces. In the diamonds studied in the present investigation, the 737nm peak related to Si was detected in PL spectra excited by a 633nm laser; this can be an important indication of CVD-grown synthetic diamond.
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  • Terumi Ejima, Masahide Akasaka, Hiroaki Ohfuji
    Session ID: R1-17
    Published: 2011
    Released on J-STAGE: March 28, 2012
    CONFERENCE PROCEEDINGS FREE ACCESS
    Oxidation state and occurrence of Fe in olivine from lherzolite xenolith in Oki Islands, Japan, were investigated. 57Fe Mössbauer spectral analysis and EMPA methods of fresh olivine on the central part of the xenolith resulted in the existence of 0.02-0.03 apfu Fe3+ in olivine. HRTEM observation and electron diffraction data of the olivine indicated that olivine has pure olivine structure, suggesting that the Fe3+ in olivines in the xenolith exists within the olivine structure. In contrast to the olivine in the core part of the xenolith, contacting with the host alkali basalt, contain fine precipitates on the rim and along fractures. Although observation using TEM indicated inclusion-like domains in this area, the domains are indentified as olivine. However, electron diffraction spots showed weak streak along c axis. These facts suggest the existence of two olivine structures with slightly different structural properties.
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  • Tahmineh Pirnia, Shoji Arai, Akihiro Tamura, Satoko Ishimaru, Ghodrat ...
    Session ID: R1-18
    Published: 2011
    Released on J-STAGE: March 28, 2012
    CONFERENCE PROCEEDINGS FREE ACCESS
    Melt-impregnated plagioclase lherzolites from Nain melange, Iran, contain pyroxenes which are enriched and chemically zoned in Sr. The pyroxenes are characterized by extremely low contents of LREE, being in equilibrium with an ultra-depleted MORB-like melt. The Sr enrichment of the pyroxenes cannot be linked to the melt impregnation because of the high compatibility of Sr in plagioclase. The Sr-enrichment is due to breakdown of plagioclase at low-temperature condition. During saussuritization, appreciable amounts of Sr have been released from plagioclase to enrich adjacent pyroxenes. The limited Sr uptakes by saussurite (assemblage of hydrogarnet and amphibole) support this fact.
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  • Isao Kusachi, Shoichi Kobayashi, Yasushi Takechi, Yoshihiro Nakamuta, ...
    Session ID: R1-P01
    Published: 2011
    Released on J-STAGE: March 28, 2012
    CONFERENCE PROCEEDINGS FREE ACCESS
    Shimazakiite occurs as grayish white aggregates up to 3 mm in diameter of tiny granular crystals in an irregular vein in crystalline limestone near gehlenite - supurrite skarns at Fuka, Okayama Prefecture, Japan. Associated minerals are takedaite, sibirskite, olshanskyite, parasibirskite, nifontovite, calcite and an undetermined hydrous calcium borate. It is Biaxial (-), α = 1.586(2), β = 1.650(2), γ = 1.667(2) (589 nm), 2V (calc.) = 53º. Electron microprobe analyses (WDS) gave an empirical formula; Ca2B1.94O4.71(OH)0.40. Electron diffraction patterns showed the minerals to be monoclinic with possible space groups of P2, P2/m, Pm, P21 or P21/m. The lattice parameters refined from IP-Gandolfi XRD data are; a = 3.532(3), b = 6.354(2), c = 19.275(9) Å, β = 91.30(8)º, V = 432.5(4) Å3, and Z = 4. The three strongest XRD lines [d in Å (I) hkl] are; 3.02 (84) 022, 2.92 (100) 112 and 2.81 (56) 11–3.
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  • Koichi Momma, Toshiro Nagase, Takahiro Kuribayashi, Masako Shigeoka
    Session ID: R1-P02
    Published: 2011
    Released on J-STAGE: March 28, 2012
    CONFERENCE PROCEEDINGS FREE ACCESS
    Chibaite is a new mineral found from Arakawa, Minami-boso City, Chiba. Chibaite has framework structures with cage-like voids occupied by natural gas molecules. In Arakawa, many of chibaite crystals are altered as white pseudomorphs of quartz after chibaite. Under polarization microscope, they exhibit banding structures ranging from several tens to hundreds μm, parallel to the original external shapes of chibaite. The internal textures of pseudomorphs often seems as if chibaite and quartz are epitaxial intergrown. In addition to white quartz pseudomorphs after chibaite, there is another type of pseudomorphs that are cubic-shaped and semi-translucent. Although the cubic-shaped quartz are probably pseudomorphs after melanophlogite, melanophlogite itself has not been found in Arakawa.
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  • Hiroshi Miyajima, Ritsuro Miyawaki, Satoshi Matsubara, Kazumi Yokoyama ...
    Session ID: R1-P03
    Published: 2011
    Released on J-STAGE: March 28, 2012
    CONFERENCE PROCEEDINGS FREE ACCESS
    A REE-Sr-Ti-dominant silicate mineral occurs as reddish brown aggregate (5 mm) in jadeitite at Itoigawa, Niigata Prefecture, Japan. The aggregate are composed of tiny rhombohedral crystals (max 0.1 mm) closely coexisted with REE-bearing matsubaraite, REE-Sr-bearing clinozoisite and natrolite. The mean of 11 electron microprobe analyses (WDS) gave SiO2 24.96, Al2O3 0.47, P2O5 0.10, TiO2 2.96, FeO 0.18, MgO 0.19, SrO 21.26, CaO 0.43, La2O3 13.94, Ce2O3 22.79, Pr2O3 2.23, Nd2O3 6.56, Sm2O3 0.30, ThO2 1.49, F 0.54, -O = F2 -0.23, total 98.16 wt.%. This leads an empirical formula (O = 27.5); (Sr3.59Ca0.13Ce2.43La1.50Nd0.68Pr0.24Th0.10Sm0.03) Σ 8.70(Ti0.65Al0.16Mg0.08Fe0.05) Σ 0.94 [SiO3 F0.50(OH)0.50](SiO3.83)6.27. Single-crystal XRD investigation showed it is hexagonal, s.p., a = 10.793(8), c = 19.31(3) Å;, V = 1958(4) Å3. This mineral is isostructural with synthetic RE9Fe(AlO3OH)(SiO4)6, and is independent from any known mineral species.
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  • Takahiko OGAWARA, Junji AKAI
    Session ID: R1-P04
    Published: 2011
    Released on J-STAGE: March 28, 2012
    CONFERENCE PROCEEDINGS FREE ACCESS
    This study was performed according to mineralogical origin contained in the carbonaceous materials (CM) in black jade from Kanayamadani Itoigawa region in Niigata Prefecture. XRD and Raman analysis is a large variation of the CM sample. Temperature distribution of Beyssec et al.(2002a) was a wide range (400-650) of values. Analysis by TEM, the most common shape was filament type. The unique morphology was Carbon nano hone and Carbonaceous globule. CM is distributed in the form of spherical or vein in the black jade. CM is considered to hydrothermal origin. Crystallinity of CM is determined by the width of XRD and Raman analysis. This shows the CM of multiple crystallization.
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  • Toshiyuki Hirama, Takashi Yamada, Yoshiaki Shiobara, Hideki Nakamura, ...
    Session ID: R1-P05
    Published: 2011
    Released on J-STAGE: March 28, 2012
    CONFERENCE PROCEEDINGS FREE ACCESS
    Pyromorphite, phosphohedyphane, mimetite and vanadinite which belong to apatite supergroup, are found in a quarry at Numata City, Gunma prefecture Japan. They are associated with descloizite, mottramite, beudantite and others. They occur as hexagonal euhedral crystals up to 1mm length or crusts in fissures of host rocks in alteration zone of gabbro. Sulfide minerals such as galena, sphalerite, arsenopyrite are rarely seen in this quarry. We describe here on the chemical analyses of their minerals, especially on phosphohedyphane, and mode of occurrence in this quarry.
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  • Masayuki Ohnishi, Norimasa Shimobayashi, Daisuke Nishio-Hamane
    Session ID: R1-P06
    Published: 2011
    Released on J-STAGE: March 28, 2012
    CONFERENCE PROCEEDINGS FREE ACCESS
    Cu-rich ramsbeckite was found in a dump of the Nii mine, Asago City, Hyogo Prefecture, Japan.
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  • Masayuki Ohnishi, Norimasa Shimobayashi, Kenji Tsuruta
    Session ID: R1-P07
    Published: 2011
    Released on J-STAGE: March 28, 2012
    CONFERENCE PROCEEDINGS FREE ACCESS
    Weddellite was found from a cavity of quartz vein at Ishidera, Wazuka, Kyoto Prefecture, Japan.
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  • Norimasa SHIMOBAYASHI, Masayuki OHNISHI, Kenji TSURUTA
    Session ID: R1-P08
    Published: 2011
    Released on J-STAGE: March 28, 2012
    CONFERENCE PROCEEDINGS FREE ACCESS
    Tungsten minerals in association with scheelite in quartz veins from the Ishidera area, Wazuka, Kyoto Prefecture, have been examined using XRD, SEM-EDS, WDS, and XRF. The X-ray powder and chemical studies demonstrated the presence of anthoinite and mpororoite, forming a powdery mixture pseudomorphing scheelite. This is the first occurrence of these two mineral species in Japan. Another tungsten mineral was also found in association with them. It occurs as regular octahedral crystals up to 50 μm. The XRD data are in good agreement with pyrochlore supergroup minerals. Since chemical analysis shows WO3, Al2O3 and H2O to be the essential constituents, this mineral should be alumotungstite, which was is the first occurrence in Japan. However, the mineral species of alumotungstite was discredited by the CNMNC-IMA and was assimilated into the "hydrokenoelsmoreite" together with ferritungstite which is commonly found in Japan.
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  • Takashi Oyama, Tetsuo Minakawa, Yukikazu Ohogoshi, Daisuke Hamane
    Session ID: R1-P09
    Published: 2011
    Released on J-STAGE: March 28, 2012
    CONFERENCE PROCEEDINGS FREE ACCESS
    Tourmalines from the Kiura emery deposit have been identified as Ca type and Na type Oxy-tourmaline. They are new tourmalines. Ca oxy tourmaline with high Al content is CaFe2AlAl6(AlSi5)O18(BO3)3(OH)3O . Na oxy tourmaline is NaAl3Al4Fe2Si6O18(BO3)3(OH)3O.
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