Search Results 1-20 of 264

  • Formation of bridgmanite-enriched layer at the top lower-mantle during magma ocean solidification

    Xie Longjian , Yoneda Akira , Yamazaki Daisuke , Manthilake Geeth , Higo Yuji , Tange Yoshinori , Guignot Nicolas , King Andrew , Scheel Mario , Andrault Denis

    … Thermochemical heterogeneities detected today in the Earth's mantle could arise from ongoing partial melting in different mantle regions. … Here we show that the MO crystallized homogeneously in the deep mantle, but with chemical fractionation at depths around 1000 km and in the upper mantle. … Fractional solidification would induce the formation of a bridgmanite-enriched layer at similar to 1000 km depth. …

    Nature Communications 11(1), 4387, 2020-01-28


  • Convection in an Internally-Heated Two-Layer System

    LIMARE Angela , JAUPART Claude , FARNETANI Cinzia , KAMINSKI Edouard , SURDUCAN Emanoil , NEAMTU Camelia , SURDUCAN Vasile

    … <p>The Earth's mantle is chemically heterogeneous and includes primordial material inherited from early planetary processes, which probably led to an initial depth-dependent composition of radioactive elements. … Mantle convection induces mixing, such that the flow pattern, the distribution of heterogeneities and the thermal structure are continuously evolving. … In analogy to the Earth's mantle, the upper layer is thicker and depleted in heat sources compared to the lower one. …



  • Unravelling the Origins of Life: Hakuba Hot-spring Chemistry of Oldest Microbes and Significance of Microbes Surviving in a Hadean-like Environment  [in Japanese]

    MARUYAMA Shigenori , SATO Tomohiko , SAWAKI Yusuke , SUDA Konomi

    … The high alkali and H<sub>2</sub>-enriched hot spring water (Type 1) differs remarkably from other hot springs in this region. … The next research target is the ecosystem in a H<sub>2</sub>-enriched environment without free oxygen.</p> …

    Journal of Geography (Chigaku Zasshi) 129(6), 757-777, 2020


  • Mineralogy and petrology of shoshonitic lamprophyre dykes from the Sivarampeta area, diamondiferous Wajrakarur kimberlite field, Eastern Dharwar craton, southern India


    … Mineralogy suggests that these lamprophyres belong to calc–alkaline variety whereas their bulk–rock geochemistry portrays mixed signals of both alkaline as well as calc–alkaline (shoshonitic) variety of lamprophyres and suggest their derivation from the recently identified Domain II (orogenic–anorogenic transitional type mantle source) from eastern Dharwar craton. … Trace element ratios imply melt–derivation from an essentially the garnet bearing–enriched lithospheric mantle source region; …

    Journal of Mineralogical and Petrological Sciences 115(2), 202-215, 2020


  • Revisiting Pb isotope signatures of Ni–Fe alloy hosted by antigorite serpentinite from the Josephine Ophiolite, USA

    KAKEFUDA Mayu , TSUJIMORI Tatsuki , YAMASHITA Katsuyuki , IIZUKA Yoshiyuki , FLORES Kennet E.

    … <p>Awaruite (Ni<sub>2–3</sub>Fe) is a natural occurring Ni–Fe alloy in serpentinite, which represents a better candidate to assess Pb isotope signatures in the mantle wedge since the concentration of Pb in awaruite is almost ten times higher than that in serpentine minerals. …

    Journal of Mineralogical and Petrological Sciences 115(1), 21-28, 2020


  • Late Ordovician back-arc extension in the southeastern margin of the Tarim Craton, NW China: Elemental and Sr-Nd isotopic constraints from the Hongliugou basalts

    Gao Xiaofeng , Xiao Peixi , Kang Lei , Xi Rengang , Li Ping , Zha Xianfeng

    … These basalts have depleted mantle-like radiogenic Nd (ε<sub>Nd</sub>(t) = +6.2~+6.7) and moderately radiogenic Sr isotopic compositions (<sup>87</sup>Sr/<sup>86</sup>Sr (i) = 0.7065–0.7068). … The combined geochemical data indicate their derivation from a moderately depleted mantle source enriched by fluids released from subducted sediments in a back-arc environment. …

    GEOCHEMICAL JOURNAL 53(6), 359-378, 2019


  • Na–bearing tremolites as reservoirs of fluid–mobile elements in the mantle wedge: inference from the Ochiai–Hokubo complex (Southwest Japan) in high–<i>P</i> schists

    ARAI Shoji , SHIRASAKA Miki , ISHIDA Yoshito , INOUE Hidehiko

    … <p>We examined the importance of tremolites as reservoirs of LILE (large–ion lithophile elements) in the mantle wedge. … The inner tremolite–bearing lherzolite is enriched with some LILE such as Na and Cs, which are stored mainly in tremolites (with up to 4 wt% Na<sub>2</sub>O) and subordinately in chlorites. … schists performed this modification on the lherzolites on progressive metamorphism, thus closely mimicking the mantle metasomatism by slab–derived fluids.</p> …

    Journal of Mineralogical and Petrological Sciences 114(5), 231-237, 2019


  • Mantle source characteristics of the late Cenozoic Mt. Baekdu (Changbaishan) basalts, North China Craton  [in Japanese]

    Hi Choi Sung


    Abstracts of Annual Meeting of the Geochemical Society of Japan 66(0), 211, 2019


  • Origin and Distribution of Geofluids and Their Roles on Geodynamics  [in Japanese]

    IWAMORI Hikaru , YUKUTAKE Yohei , IIO Yoshihisa , NAKAMURA Hitomi

    … <p> A total of one to ten ocean masses of water (including H<sub>2</sub>O, OH, H in gas, liquid, and solid phases) is probably stored in the Earth's crust-mantle system as a variety of forms and components. …

    Journal of Geography (Chigaku Zasshi) 128(5), 761-783, 2019


  • Sr–Nd isotopic compositions of the Susuma–Nagaho Plutonic Complex in the San–yo Belt, Southwest Japan: Implications for the Cretaceous enriched mantle

    KODAMA Shogo , OWADA Masaaki , IMAOKA Teruyoshi , KAMEI Atsushi

    … The fine–grained gabbro has a high Mg–number similar to primitive basalt with negative εNd values corrected to 92 Ma although Cr and Ni contents are relatively low, which indicates that the basaltic magma may have been derived from enriched mantle. …

    Journal of Mineralogical and Petrological Sciences 114(2), 99-104, 2019


  • Fossilized Melts in Mantle Wedge Peridotites

    Naemura Kosuke , Hirajima Takao , Svojtka Martin , Shimizu Ichiko , Iizuka Tsuyosi

    … The shallow oxidized asthenosphere may contain a small fraction of potassic silicate melts that are enriched in incompatible trace elements and volatiles. … Garnet-poor (2 vol.%) peridotite preserves inclusions of carbonated potassic silicate melt within Zn-poor chromite (<400 ppm) in the clinopyroxene-free harzburgite assemblage that equilibrated within the hot mantle wedge (Stage 1,  > 1180 °C at 3 GPa). …

    Scientific Reports (8), 2018-07-04


  • Feedback of mantle metasomatism on olivine microfabric and seismic properties of the deep lithosphere  [in Japanese]



    Abstracts of Annual Meeting of the Geochemical Society of Japan 65(0), 62, 2018


  • Mineralogical characterization and formation process of spherulite in the rhyolitic welded tuff from Aga town, Niigata Prefecture, Japan  [in Japanese]

    ECHIGO Takuya , SAITO Yoichiro , KIMATA Mitsuyoshi , SHIMIZU Masahiro , NISHIDA Norimasa , TAKIZAWA Shigeru

    … Textural observation using back-scattered electron image and micro-Raman spectroscopy showed that the present spherulite has three layers structure: rim (dense texture), mantle (porous texture) and core (fan-shaped aggregates of fibrous crystals). … The results demonstrated that both Ca and Na are enriched in both the rim and core of spherulite, suggesting that plagioclase distributes dominantly in these parts. …

    Japanese Magazine of Mineralogical and Petrological Sciences 47(2), 69-81, 2018


  • Multi-Element Profiling Analyses of Symbiotic Zooxanthellae and Soft Tissues in a Giant Clam (<i>Tridacna crocea</i>) Living in the Coral Reefs and Their Intake Process of Zn and Cd

    Itoh Akihide , Kabe Noriko , Kuwae Sho , Oura Eriko , Hisamatsu Shin , Nakano Yoshikatsu , Zhu Yanbei

    … <p>Approximately 20 major-to-ultratrace elements in each organ (mantle, muscle, liver, kidney) of a giant clam, <i>Tridacna crocea</i>, and 16 elements in symbiotic zooxanthellae were determined by ICP-AES, ICP-MS, and CHN coder. … However, the concentrations of Mn, Co, Ni, Zn, Se, Ag, Cd, and Pb in the mantle were higher than those in the muscle and liver. … for U based on dry weight after isolating zooxanthellae from the mantle. …

    Bulletin of the Chemical Society of Japan 90(5), 520-526, 2017


  • High-Pressure and High-Temperature Carbon Isotope Fractionation in the Fe-C System: Implications for Carbon Dynamics in the Deep Earth  [in Japanese]

    Satish-Kumar MADHUSOODHAN

    … However, the distribution of carbon isotopes in the core and deep mantle remains elusive. … The temperature dependent fractionation of carbon isotopes between carbide phases and elemental carbon can be an effective mechanism that might have created a <sup>12</sup>C-enriched core. …

    The Review of High Pressure Science and Technology 27(4), 278-283, 2017


  • Chemical composition of fluid inclusions in the Yorii jadeite–quartz rocks from the Kanto Mountains, Japan

    FUKUYAMA Mayuko , KAWAMOTO Tatsuhiko , OGASAWARA Masatsugu

    … The trace element concentrations of fluid inclusions determined with LA–ICP–MS are enriched in LILE, Li, B, HFSE and transition metals with LILE enriched and relatively HFSE depleted characteristics. … HFSE from the fluid can be sequestered into jadeite–quartz rock prior to fluids moving up into a mantle wedge. … This process lead the evolved fluids relatively depleted in HFSE and enriched in LILE. …

    Journal of Mineralogical and Petrological Sciences 112(5), 281-290, 2017


  • REEs mineralization in a Fe-Cu skarn deposit associated with calc-alkaline magmatism  [in Japanese]

    Jianwei Li , Hao Hu

    <p>The Tieshan Fe-Cu skarn deposit in the Daye district of eastern China provides a valuable opportunity to better understand the nature and genesis of hydrothermal REEs mineralization associate …

    Abstracts of Annual Meeting of the Geochemical Society of Japan 64(0), 28, 2017


  • Barium isotope geochemistry  [in Japanese]

    Fang Huang

    <p>Baはマントル融解中に非常に相溶性がないため、マントルに対してクラストが強く濃縮されています。 さらに、流体移動要素として、実質的なBaが沈み込み中に流体に侵入し、おそらくマントルウェッジのBa同位体異質性をもたらす。Ba同位体は潜在的に沈み込み物質の再循環と地殻 - マントル相互作用を追跡するために使用することができる。 Ba同位体はまた、表面環境におけるプロセスを制限するため …

    Abstracts of Annual Meeting of the Geochemical Society of Japan 64(0), 207, 2017


  • Study on material evolution at the early stage of our solar system by using radiochemical methods  [in Japanese]

    Ebihara Mitsuru

    … both elements are extremely depleted in well-washed olivine and are enriched in the leachate. … Our data support that pallasites formed in the boundary region of metallic core and silicate mantle. …

    Chikyukagaku 51(3), 119-133, 2017


  • Results of Basement Drilling on Oceanic LIPs  [in Japanese]

    Sano Takashi

    <p>21世紀に入ってから,2つの海洋LIPs(オントンジャワとシャツキー海台)で基盤溶岩を採取する掘削が行われた.基盤溶岩は大陸洪水玄武岩の塊状層状溶岩流と類似していた.元来,両LIPsはプルーム頭部がプレート境界に衝突して生産されたと考えていたが,<sup>40</sup>Ar-<sup>39</sup>Ar年代は熱プルームモデルから …

    The Journal of the Geological Society of Japan 123(4), 207-223, 2017


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