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Tadashi Yokoyama, Hiroshi Sakuma
Session ID: R4-04
Published: 2018
Released on J-STAGE: January 16, 2020
CONFERENCE PROCEEDINGS
FREE ACCESS
According to known diffusion coefficients of Si, K, Cl in bulk water [
D0,K ≈
D0,Cl = 1.7 ×
D0,Si], diffusion rate of Si was expected to be ~1.7 times as large as those of K and Cl. However, through diffusion experiment for measuring diffusion rates of K, Cl, Si in rock pore water showed that Si diffused slower than expected from the difference of D
0 values. Based on MD simulation for evaluating the concentration dependence of Si, K, Cl on diffusivity, the slow diffusion of Si is likely to be due to cluster formation of Si.
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Mukai Hiroki, Yoshiaki Kon, Kenzo Sanematsu
Session ID: R4-05
Published: 2018
Released on J-STAGE: January 16, 2020
CONFERENCE PROCEEDINGS
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Ion adsorption type ores existing mainly in southern part of China are important as a supply source of rare earth elements (REE) which are essential for cutting edge industries. However, it is unclear what kind of minerals adsorb REE in the ores because the concentrations of REE are relatively low, and direct observations for monophase minerals have been rarely conducted. In the present study, we have attempted to clarify the minerals adsorbing REE using various experimental apparatus.
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Hiroki Hagiwara, Hiromi Konishi, Takahiro Nakanishi, Kenso Fujiwara, ...
Session ID: R4-06
Published: 2018
Released on J-STAGE: January 16, 2020
CONFERENCE PROCEEDINGS
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As already known, radiocaesium is transported with organic materials or onto small size particles such as clay minerals under the river flow condition. Thus, it is important to determine the relationship between mineral species and their radiocaesium concentration.
The results showed that the radiocaesium almost contained in sand fraction. We suggested the importance of radiocaesium quantity not only clay fraction but also sand fraction. In addition, mafic and felsic minerals in sand fraction could be contribute migration of radiocaesium as transport materials at river basin.
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Satoshi Utsunomiya
Session ID: R4-07
Published: 2018
Released on J-STAGE: January 16, 2020
CONFERENCE PROCEEDINGS
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Trace U was released from the Fukushima Daiichi Nuclear Power Plant (FDNPP) during the meltdowns. The speciation of U records the meltdown processes and property of debris, and also determines the environmental impacts. This study summarizes various types of U derived from the FDNPP focusing on the speciation to provide the updated knowledge on the behaviour of nuclear fuels during the meltdowns at the FDNPP.
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Hiromi Konishi, Mikiko Sato, Yang Wei
Session ID: R4-P01
Published: 2018
Released on J-STAGE: January 16, 2020
CONFERENCE PROCEEDINGS
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Dolomitization of coral reefs on Minami Daito Jima
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Jun-ya Tanaka, Jun Kawano, Takaya Nagai, Henry Teng
Session ID: R4-P02
Published: 2018
Released on J-STAGE: January 16, 2020
CONFERENCE PROCEEDINGS
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Precipitation experiments have been conducted in order to understand the formation process of magnesium carbonates in aqueous solution with various Mg/CO
3 ratios. Amorphous magnesium carbonate formed from MgCO
3 aqueous solution and transformed into nesquehonite (MgCO
3・3H
2O), one of the hydrated magnesium carbonates. Hydration /dehydration of ions may play an important role in these formation process.
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Ryosuke Kikuchi, Koji Ichimura, Yoshio Takahashi, Yoichi Sakai, Toshih ...
Session ID: R4-P03
Published: 2018
Released on J-STAGE: January 16, 2020
CONFERENCE PROCEEDINGS
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Spatial distribution in chemical compositions and Fe valence states within weathered biotite grain were examined through microanalytical techniques of FE-EPMA and μ-XAFS. Different packets of vermiculite-enriched and biotite-dominant were found to be interstratified at each interval of ~ several μm, there was no difference in Fe-K XANES spectra obtained from those respetive packets. These results suggest that vermiculitization is not necessarily associated with layer charge reduction in weathered biotite.
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Tatsuro Manabe, Hiromi Konishi
Session ID: R4-P04
Published: 2018
Released on J-STAGE: January 16, 2020
CONFERENCE PROCEEDINGS
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Iron precipitation by
Chloroflexus aurantiacus
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Mone Fukiya, Hiromi Konishi
Session ID: R4-P05
Published: 2018
Released on J-STAGE: January 16, 2020
CONFERENCE PROCEEDINGS
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Micronuggets formed by long-term cultures of
Cupriavidus metallidurans
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Nina Yokoi, Takashi Mikouchi, Atsushi Takenouchi, Tomoko Arai
Session ID: R5-01
Published: 2018
Released on J-STAGE: January 16, 2020
CONFERENCE PROCEEDINGS
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We measured Fe valence in plagioclase from 13 lunar rocks (9 Apollo, 1 Luna and 3 lunar meteorites) by synchrotron Fe-XANES to see the relationship between redox states and water contents. Plagioclase in HT and KREEP basalts shows lower Fe
3+ ratios compared to LT and VLT basalts, which is related to the water content. On the other hand, plagioclase in highland rocks (FAN and MAN) have high Fe
3+ ratios despite small water contents, suggesting the presence of oxidant other than water.
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Yoshie Takayama, Hiroaki Ohfuji
Session ID: R5-02
Published: 2018
Released on J-STAGE: January 16, 2020
CONFERENCE PROCEEDINGS
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We studied micro-inclusions in olivine in a pallasite meteorite, Seymchan using SEM-EDS and TEM. The micro-inclusions have droplet shapes and are linearly arranged in the host. They consist mainly of troilite and Fe-Ni alloy, with some minor phases. They are likely formed through the injection of a partial melt from the matrix along cracks, since the mineral assemblages are comparable to those observed in the matrix. The presence of tridymite implies the formation of the micro-inclusions at a relatively low-pressure and high-temperature condition.
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Haruka Ono, Atsushi Takenouchi, Takashi Mikouchi, Akira Yamaguchi
Session ID: R5-03
Published: 2018
Released on J-STAGE: January 16, 2020
CONFERENCE PROCEEDINGS
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We analyzed silica polymorphs in two basaltic clasts and matrix of Y-75011 (polymict eucrite). Many kinds of silica combinations have been found such as monoclinic and orthorhombic tridymites. We consider that such variety of silica minerals indicates different cooling processes before brecciation. We also found monoclinic tridymite in the matrix with a corona-like texture, which is nearly identical to ones in Pasamonte (polymict eucrite). This suggests that they came from the same parent body.
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Hideyuki Hayashi, Atsushi Takenouchi, Takashi Mikouchi, Martin Bizzarr ...
Session ID: R5-04
Published: 2018
Released on J-STAGE: January 16, 2020
CONFERENCE PROCEEDINGS
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Almost all of angrites lack shock metamorphism, but recently we have found that the NWA 7203 angrite shows remarkable textures of shock metamorphism (up to 20 GPa shock pressure), suggesting that some angrite parent bodies remained as big asteroids during late heavy bombardment.
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Masahiro Yasutake, Akira Yamaguchi
Session ID: R5-05
Published: 2018
Released on J-STAGE: January 16, 2020
CONFERENCE PROCEEDINGS
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Lodranite NWA 2235 has a coarse-grained texture consisting of euhedral olivine and poikilitic low-Ca pyroxene and augite that enclose olivine. A few olivine grains enclose SiO
2-rich glasses. Olivine LPO is characterized by a point maximum of b-axis and a girdle of c-axis. Olivine grain shape oriented to the normal direction to the b-axis point maximum. These results indicate that NWA 2235 is a cumulate rock formed in the magma chamber rather than a residual rock.
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Hikari Hasegawa, Takashi Mikouchi, Martin Schiller, Martin Bizzarro
Session ID: R5-06
Published: 2018
Released on J-STAGE: January 16, 2020
CONFERENCE PROCEEDINGS
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Brachinites are thought to be one of primitive achondrite groups and are known to have ancient crystallization ages. They are keys to understand the early stage of planetary differentiation in our Solar System. However, there have not been a consensus on their origin. In this study, we report mineralogy and Cr stable isotopic compositions of three brachinites. We plan to measure olivine fabrics using EBSD and will report their data at the meeting.
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Takashi Mikouchi, Atsushi Takenouchi, Kotaro Higashi, Michael Zolensky
Session ID: R5-07
Published: 2018
Released on J-STAGE: January 16, 2020
CONFERENCE PROCEEDINGS
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MS-MU-011 and MS-MU-012 of Almahata Sitta meteorite are O-isotopically ureilitic, but are trachyandesite and plagioclase-bearing, respectively. Fe
3+ ratios of feldspar in MS-MU-011 (SR-XANES) are up to 0.48, suggesting crystallization under an oxidizing condition. Our MS-MU-012 does not contain plagioclase, but the reduction rim of olivine gives a fast cooling rate (0.2
oC/hr), corresponding to break-up of the ureilite parent body. In MS-MU-012 plagioclase somehow escaped from being removed.
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Atsushi Takenouchi, Takashi Mikouchi, Takamichi Kobayashi, Toshimori S ...
Session ID: R5-08
Published: 2018
Released on J-STAGE: January 16, 2020
CONFERENCE PROCEEDINGS
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We performed pre-heated shock recovery experiments to reveal contributions of temperature for shock textures. Initial high-temperature induced lowering shock pressures for maskelynitization. Olivine shocked at 39 GPa/750
oC showed a new Raman peak around 670 cm
-1 which has been obtained from olivine around shock melts in highly shocked Martian meteorites. Temperature-controlled shock experiments will provide better constraints on relations between shock pressures and corresponding features.
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Masaaki Miyahara, Akira Yamaguchi, Kanta Fukimoto, Masato Saitoh, Hiro ...
Session ID: R5-09
Published: 2018
Released on J-STAGE: January 16, 2020
CONFERENCE PROCEEDINGS
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High-pressure polymorphs formed in H-, L- and LL-type ordinary chondrites (OCs) were systematically investigated with FE-SEM and Raman spectroscopy. Many high-pressure polymorphs occur in the shock melting texture of both L- and LL-type OCs, whereas few in H-type OCs. Although many kinds of high-pressure polymorphs occur in petrologic type 6, only Na-pyroxene occur as the replacement of plagioclase or chondritic glass in petrologic type 3-5. The abundance and species of high-pressure polymorphs are closely related with the species of OCs and petrologic types.
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Naoya Imae, Makoto Kimura, Akira Yamaguchi, Hideyasu Kojima
Session ID: R5-10
Published: 2018
Released on J-STAGE: January 16, 2020
CONFERENCE PROCEEDINGS
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Ordinary chondrites consisting of the chemical group (H, L, and LL) have experienced various degrees of thermal and shock metamorphism. Random X-ray diffraction patterns for ordinary chondrites were obtained using in-plane rotation of polished thin section, mainly focusing on olivine, low-Ca clinopyroxene, and low-Ca orthopyroxene. Then the four patterns were clearly recognized: weak shock equilibrated, weak shock unequilibrated, strong shock equilibrated, and shock melted.
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JUNYA MATSUNO, Akira Tsuchiyama, Akira Miyake, Kentaro Uesugi, Akihisa ...
Session ID: R5-11
Published: 2018
Released on J-STAGE: January 16, 2020
CONFERENCE PROCEEDINGS
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We performed three dimentional observations of 7 CP-IDPs using X-ray CT at SPring-8. 5 IDPs contain fine minerals and one of them has 10 micro-sized chondrule.
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Okuchi Takuo, Purevjav Narangoo, Naotaka Tomioka, Tsuchiyama Akira, Sh ...
Session ID: R5-12
Published: 2018
Released on J-STAGE: January 16, 2020
CONFERENCE PROCEEDINGS
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We previously demonstrated that quasielastic neutron scattering is uniquely effective for analyzing atomic-scale hydrogen transport processes in crystalline hydrous minerals. We recently started to apply it for analyzing hydrogen transport in hydrated amorphous silicate of nanoscale particles. From the results at
T≦300 K where crystallization does not occur, we identified two types of transport processes, which have implication for water storage mechanism in this potential career of water into early Earth.
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Daiki Yamamoto, Michiru Kamibayashi, Noriyuki Kawasaki, Shogo Tachiban ...
Session ID: R5-13
Published: 2018
Released on J-STAGE: January 16, 2020
CONFERENCE PROCEEDINGS
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Oxygen isotopic exchange experiments between Ca-, Al-rich inclusion (CAI) melt and H
218O vapor were carried out at 1390°C and P
H2O of 5×10
-2 Pa for 3 and 18 hours. Run products were mostly glass with a small amount of spinel, and showed oxygen isotopic zoning with
18O enrichment toward the sample surface, yielding the diffusion coefficients of 2.1 × 10
-7 and 4.8 × 10
-7 cm
2 sec
-1 for samples heated for 3 and 18 hours, respectively. The isotopic exchange efficiency between water vapor and the CAI melt at the surface was estimated to be ~0.1.
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Makoto Kimura, Mutsumi Komatsu, Akira Yamaguchi, Naoya Imae
Session ID: R5-14
Published: 2018
Released on J-STAGE: January 16, 2020
CONFERENCE PROCEEDINGS
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We studied an unusual AOA in Yamato-793261 (CR), including ultrarefractory minerals and quartz after Komatsu et al. (2018). It abundantly contains enstatite, and some enstatites occur between forsterite and quartz, suggesting the reaction between them.
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Akane Iemoto, Yusuke Seto, Akira Miyake
Session ID: R5-15
Published: 2018
Released on J-STAGE: January 16, 2020
CONFERENCE PROCEEDINGS
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We report microtexture of tochilinite-cronstedtite intergrowths (TCIs) in CM chondrites. In QUE97990 and Murchison, less altered CM meteorites, the TCIs showed the texture with thin tochilinite veins inside cronstedtite, suggesting that tochilinite formed after the formation of cronstedtite. In Nogoya, the fibrous TCIs continuously changed to serpentine aggregates. This suggests that fluid compositions had varied during the course of alteration.
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Akira Tsuchiyama, Akira Miyake, Jun Kawano
Session ID: R5-16
Published: 2018
Released on J-STAGE: January 16, 2020
CONFERENCE PROCEEDINGS
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We found nano-sized CO
2-H
2O fluid inclusions in calcite grains of a CM carbonaceous chondrite using TEM observation with a cryogenic holder. This fluid was incorporated into calcite grains as inclusions during aqueous alteration in the parent body of the meteorite. If CO
2was originated from CO
2ice, the parent body should be formed in an outer region of the Solar System, which is beyond the CO
2snow line.
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Kotaro Higashi, Takashi Mikouchi, Yasuhito Sekine, Michael E. Zolensky
Session ID: R5-17
Published: 2018
Released on J-STAGE: January 16, 2020
CONFERENCE PROCEEDINGS
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We studied aqueously altered EH and EL in Kaidun. Two clasts show alteration of Fe-Ni metal and plagioclase and elongated Ca carbonate is often present at the boundary between altered E chondrite and surrounding C chondrite. These features are similar to the E chondrite clast in Kaidun #40.7.1, suggesting they experienced same alteration. We have carried out hydrothermal experiments with EL5 in HCl, H
2O, NaCl and NaOH. In HCl, Fe-Ni metal and troilite disappeared, and therefore the aqueously altered conditions of E chondrites in Kaidun was not under an acidic condition.
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Miki Takahashi, Tomoki Nakamura, Takazo Shibuya, Michael E Zolensky
Session ID: R5-18
Published: 2018
Released on J-STAGE: January 16, 2020
CONFERENCE PROCEEDINGS
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Dark Inclusion (DI) in NWA 2900 CK3 consists mainly of olivine, magnetite and plagioclase with large veins of diopside. Thermodynamic calculations indicates that the mineral assemblages observed in this dark inclusion can be obtained at temperature higher than 700C during high temperature aqueous alteration. This indicates that the dark inclusion experienced hydrothermal alteration with super critical water. Therefore, the presence of the DI with such diopside veins implies that a large and hot hydrous primordial asteroid was present in the early solar system.
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Yusuke Seto, Shiori Adachi, Shun Ichimura
Session ID: R5-19
Published: 2018
Released on J-STAGE: January 16, 2020
CONFERENCE PROCEEDINGS
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We performed hydrothermal experiments of anorthite with solutions of various pH and Na
+ concentration, and made crystal identifications, micro-textural analyses to constrain environments in carbonaceous chondrite parent bodies by revealing process of nephelinization. As a result, anorthite-rich plagioclase are favorably altered into zeolites. Using Na
+ and Cl
- -rich solution, significant amounts of secondary phases including sodalite were formed even under moderate alkaline condition.
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Takaaki Noguchi, Ryosuke Sagae, Hidemi Ishibashi, Shoko Odake, Hiroyuk ...
Session ID: R5-20
Published: 2018
Released on J-STAGE: January 16, 2020
CONFERENCE PROCEEDINGS
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By combining Fe Kα XANES analysis,
57Fe Mossbauer spectroscopy, and EPMA analysis of cronstedtite, we were able to transform the Fe
3+/Fe
2+ area intensity ratios to the Fe
3+/Fe
2+ atomic ratios for serpentine-group minerals (Fe-rich serpentine and cronstedtite). By using this relationship, we applied Fe Kα XANES analysis of serpentine-group minerals in 11 CM chondrites. There is a weak positive correlation between Fe*/(Mg+Fe*) ratios and Fe
3+/ΣFe atomic ratios if we use the average values of these ratios for each meteorite.
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Huimin Shao, Hiroshi Isobe, Bingkui Miao
Session ID: R5-P01
Published: 2018
Released on J-STAGE: January 16, 2020
CONFERENCE PROCEEDINGS
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Cosmic spherules, the completely melted micrometeorites, representing interplanetary materials from asteroids and comets. In order to reproduce I-type cosmic spherules, we carried out a series of rapid heating and quenching experiments on powders from iron meteorite Canyon Diablo. Typical textures in run products are classified into three groups. The chemical compositions of run products with quantitative analysis of oxygen are ploted on the Fe-Ni-O system and discussed.
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Hiroshi Isobe, Kento Murozono
Session ID: R5-P02
Published: 2018
Released on J-STAGE: January 16, 2020
CONFERENCE PROCEEDINGS
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Micrometeorites have the most abundant flux in accumulation of planetary materials to the Earth and may have environmental effect at upper atmosphere. Compositions of FeS derived melt in fine spherules are following Fe-S-O phase relations even in a few seconds. Troilite in micrometeorite is melted, oxidized and vaporized depending on oxygen fugacity.
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Megumi Matsumoto, Junya Matsuno, Akira Miyake, Aiko Nakato, Akira Tsuc ...
Session ID: R5-P03
Published: 2018
Released on J-STAGE: January 16, 2020
CONFERENCE PROCEEDINGS
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Primitive meteorites contain little amounts of presolar grains which formed in circumstellar environments before the Solar System formation. Detailed observations of these grains are important in understanding formation processes of solid materials in space. In this study, we performed TEM analyses and STEM-EDS tomography on one presolar silicate grain found in Acfer 094 meteorite to understand its formation history.
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Takafumi Kimura, Kazuhito Ozawa, Tusyoshi IIzuka
Session ID: R6-01
Published: 2018
Released on J-STAGE: January 16, 2020
CONFERENCE PROCEEDINGS
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We tackle to detect the mantle dynamics of slab breakoff by the high time resolution approach. We established the stratigraphy of the Cumulate Member in the Hayachine-Miyamori ophiolite. The variation of Dy/Yb ratio of clinopyroxene increases with the stratigraphic height, which indicates that deepening of melting depth to ~170km. The increase in melting depth can be explained by slab breakoff. We succeed in detecting the slab breakoff on the scale of several million years.
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Eiichi TAKAZAWA, Peter B Kelemen, Damon H Teagle, Juerg Matter, Jude C ...
Session ID: R6-02
Published: 2018
Released on J-STAGE: January 16, 2020
CONFERENCE PROCEEDINGS
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Drilling of the crust-mantle boundary by ICDP Oman Drilling Project took place in November 2017 to January in Wadi Zeeb of Wadi Tayin massif in the Oman Ophiolite. Cores with total lengths of 404.15 m and 300.00 m were sampled from two holes of Hole CM1A and CM2A. These cores are being observed by detailed core descriptions and various measuring instruments in the Deep-Sea Scientific Drilling Vessel "CHIKYU" from July 5, 2018. We will report the results of these activities.
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Natsue Abe, Keishi Okazaki, Kohei Hatakeyama, Benoit Ildefonse, Yamato ...
Session ID: R6-03
Published: 2018
Released on J-STAGE: January 16, 2020
CONFERENCE PROCEEDINGS
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We report the initial results of the physical property measurements of core samples from the 4 Holes drilled at Samail Ophiolite, Sultanate of Oman, during the Oman Drilling Project Phase I. Phase 1 cores are from the lower crust section (Holes GT1A & 2A), at the boundary between sheeted dike and gabbro (Hole GT3AB), and from the mantle section to the basal thrust through the metamorphic sole. Physical Properties (Vp, density & porosity, thermal conductivity, etc) on core samples were measured using analytical facilities on D/V Chikyu.
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Tomoaki Morishita Morishita, Peter B. KELEMEN, Judith COGGON, Juerg MA ...
Session ID: R6-04
Published: 2018
Released on J-STAGE: January 16, 2020
CONFERENCE PROCEEDINGS
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We report results on International Continental Drilling Project cores aiming at the leading edge of the mantle wedge and the underlying metamorphic sole of the Oman ophiolite, Hole BT1B of the Oman Drilling Project, on board the Drilling Vessel CHIKYU.
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Nobutaka Tsuchiya, Daisuke Yamazaki
Session ID: R6-05
Published: 2018
Released on J-STAGE: January 16, 2020
CONFERENCE PROCEEDINGS
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The partial melting of depleted peridotite plus slab melt at 1.5 GPa was studied for H
2O saturated conditions. The quenched glasses obtained at 1000℃ are dacitic in composition, having 67-68 wt% SiO
2. On the other hand, the quenched glasses obtained at 1050℃ are andesitic in composition, 61-64 wt% SiO
2. This suggests that calk-alkaline dacites to andesites can be generated by the reaction of slab melts with mantle peridotite.
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Atsushi Kamei, Akane Koganei, Tabara Atsushi, Ohira Hiroto
Session ID: R6-06
Published: 2018
Released on J-STAGE: January 16, 2020
CONFERENCE PROCEEDINGS
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Sennoyama is a remnant of pyroclastic cone located in the Oe-Takayama volcanic district, SW Japan. This area is well-known as Iwami Ginzan silver mine. The timing of volcanic activity is 2.1-1.7 Ma. Kano and Takarada (2007) suggested that the cone was produced by basal base surge deposits and subsequent block-and-ash flow deposits. In this study, we start the geological survey and XRF analysis to investigate the volcanic structure and its significance to the silver mineralization.
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Seiji Maruyama, Keiji Takemura, Takafumi Hirata, Tohru Yamashita, Tohr ...
Session ID: R6-07
Published: 2018
Released on J-STAGE: January 16, 2020
CONFERENCE PROCEEDINGS
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The petrographic properties of the visible tephra layer samples obtained from the SG93 and SG06 boring core samples from Lake Suigetsu, central Japan, are presented together with the data of the major- and trace-element concentrations of the volcanic glass shards. The Suigetsu tephra layers can be roughly classified into the tephras derived from the calderas on Kyushu Island, and the Daisen and the Sambe volcanoes. A tephra sample correlated with the Sambe-Kisuki tephra based on the petrographic properties showed the element pattern similar to those of tephras from northeast Japan.
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Shin-ichi Kagashima, Yoshimitsu Suda, Hayato Ueda
Session ID: R6-P01
Published: 2018
Released on J-STAGE: January 16, 2020
CONFERENCE PROCEEDINGS
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The Cape Hinode in East Antarctica is mainly consists of tonalite, which is adakitic rocks. Granites are small amount of this area, and also similar to high SiO
2 adakite. The zircon U-Pb ages of granites are 1081±25 Ma~1026±23 Ma. Granites has low MgO, Cr and Ni contents, it seems that there are no reaction with the mantle. In addition, granites coincide with the composition range of TTG (>3.5 Ga). These evidence suggests that melting of young and hot slab in shallow subduction zone. It becomes a key to elucidate the tectonics about 1000 Ma.
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Munkhdelger Bold, Yasuhito Osanai, Nobuhiko Nakano, Tatsuro Adachi, Ta ...
Session ID: R6-P02
Published: 2018
Released on J-STAGE: January 16, 2020
CONFERENCE PROCEEDINGS
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The Ereendavaa area is located in the NE Mongolia, whereas various types of granitoids are distributed. The purpose of study is to understand the tectonic evolution of this area based on characteristics of granitoids. Therefore, we identified syn-collisional S-type and arc-related I-type granitoids. S-type granitoids were respectively formed at ca. 880 Ma, ca. 440 Ma and ca. 220 Ma. I-type granitoids were individually generated at ca. 540 Ma, ca. 470 Ma and ca 220 Ma in the Ereendavaa area.
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Yasuhiro Ogita, Takenori Kato, Takashi Yuguchi
Session ID: R6-P03
Published: 2018
Released on J-STAGE: January 16, 2020
CONFERENCE PROCEEDINGS
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This study reveals the crystallization processes of magmatic-origin quartz crystals, based on cathodoluminescence (CL) analyses and quantitative determinations of titanium concentration in quartz. The CL patterns are classified into 6 groups. Quantitative determinations of titanium concentration in quartz are analyzed by EPMA housed at Nagoya University, giving the value ranging from 40 to 200 ppm.
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Masatsugu Ogasawara, Kenji Horie, Mami Takehara, Tomohide Ohtsubo, Yas ...
Session ID: R6-P04
Published: 2018
Released on J-STAGE: January 16, 2020
CONFERENCE PROCEEDINGS
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Various granitoids occur in the Asahi Mountains, northeast Japan. SHRIMP zircon U-Pb ages were obtained to understand timing of igneous activity of the area. On the basis of the age data, granitoids are grouped into older (99- 87 Ma) and younger (69-64 Ma) members.
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Yukiko Ohtomo, Orie Takahashi, Nao Ikeda
Session ID: R6-P05
Published: 2018
Released on J-STAGE: January 16, 2020
CONFERENCE PROCEEDINGS
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Boundary zone of the Wariyama and Takase granites were observed in Takaseosawa, the Mafune and Myotu Passes. Basic metamorphic rock, mud stone and dioritic rock are associated with the Wariyama granite. It is thought that these rocks are contact with the Takase granite in fault zone.
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Lena Yokokura, Junji Yamamoto
Session ID: R6-P06
Published: 2018
Released on J-STAGE: January 16, 2020
CONFERENCE PROCEEDINGS
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The cause of backarc magmatism such as the volcanic groups near the border of North Korea and China, west of the Japanese archipelago is still controversial. A possibility for the magmatism is a mantle plume derived from lower mantle. The other is the magmatism related to dehydration of slab. In order to clarify the cause, we measured isotopic compositions of noble gases extracted from inclusions (mainly melt inclusions) in mantle xenoliths collected from volcanoes in northeastern China.
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Takashi Yuguchi, Kaho Shoubuzawa, Yasuhiro Ogita, Koshi Yagi, Masayuki ...
Session ID: R6-P07
Published: 2018
Released on J-STAGE: January 16, 2020
CONFERENCE PROCEEDINGS
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This study presents the plagioclase alteration process with a focus on the role of micropores, mass transfer
and reaction rate in the Toki granitic pluton, central Japan.
The plagioclase alteration process involves an albitization, K-feldspathization and the formation of illite, calcite, fluorite and epidote. Such secondary minerals of hydrothermal origin in plagioclase within granitic rocks record the chemical characteristics of the hydrothermal fluid.
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Saki Watanabe, Satoshi Saito
Session ID: R6-P08
Published: 2018
Released on J-STAGE: January 16, 2020
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The Miocene Kaikomagatake pluton is one of the Neogene granitoid plutons exposed in the Izu Collision Zone. In order to constrain the emplacement depth of the pluton, we applied the Al-in-hornblende geobarometer (Anderson and Smith, 1995). We used samples with mineral assemblage of hornblende + biotite + plagioclase + quartz + K-feldspar + magnetite + ilmenite ± sphene. Rim compositions of hornblende were used for barometry. Applying the barometer to 8 samples yielded 2.2 - 3.6 kbar. The estimated pressures correspond to ~9 - 14 km for the emplacement depth of the Kaikomagatake pluton.
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Shogo Kodama, Masaaki Owada, Teruyoshi Imaoka, Atsushi Kamei
Session ID: R6-P09
Published: 2018
Released on J-STAGE: January 16, 2020
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The Susuma-Nagao granodiorite, central Yamaguchi, contains a gabbro body. The gabbro is divided into two types; fine-grained gabbro and cumulate. Considering Sr-Nd isotopic compositions, they are derived from the same parental magma and belong to the transitional zone.
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Motohiro Sato, Masao Ban
Session ID: R6-P10
Published: 2018
Released on J-STAGE: January 16, 2020
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We performed petrologic examination on pre-eruptive process of upper most unit of Goshikidake pyroclastic rocks of Zao volcano. The products were calk-alkaline andesite and were formed by mixing between two end-members. The estimated time scale from mixing to eruption based on zoning profiles of opx thin and relatively broad reverse zoned rims are 1.5 days to several weeks and 5 to 20 years respectively. Meanwhile, the time scale magma scent from shallow chamber to the surface, based on the decompression rate meter using microlite density and composition was estimated to several days.
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Ai Takano, Toshiki Nishii, Shoichi Kobayashi
Session ID: R6-P11
Published: 2018
Released on J-STAGE: January 16, 2020
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Basalt to basaltic andesite formed by monogenetic volcanoes is distributed along the vents extending from NW to SE direction in the eastern part of the Izu Peninsula. Among the volcanic group along the vent indicated by Koyama & Umino (1991), three volcanoes groups, 1) IT group (0 to 4 ka), 2) KT group (10 to 20 ka) 3) KW group (20 to 40 ka), were selected, and chemistry of rock and its constituent minerals in each group were examined. In particular, we investigated the relationship between chemical changes of zonal structure observed in phenocryst minerals and magma composition.
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