Published Papers - SHINJO Ryuichi

Neotectonic stress field and deformation pattern within the Zagros and its adjoining area: An approach from finite element modeling

Islam, M.S. and Shinjo, R.

Journal of Geology and Mining Research ( その他の出版社 )  2   170 - 182   2010

Type of publication: Research paper (scientific journal)

Improved method for Hf separation from silicate rocks for isotopic analysis using Ln-spec resin column

Shinjo, R., Ginoza, Y. and Meshesha, D.

Journal of Mineralogical and Petrological Sciences ( その他の出版社 )  105   297 - 302   2010

Type of publication: Research paper (scientific journal)

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Submarine active normal faults completely crossing the southwest Ryukyu Arc

Matsumoto, T., Shinjo, R., Nakamura, M., Kimura, M. and Ono, T.

Tectonophysics ( その他の出版社 )  466   289 - 299   2009 [ Peer Review Accepted ]

Type of publication: Research paper (scientific journal)

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Mining-induced fault reactivation associated with the main Conveyor Belt Roadway and safety of the Barapukuria Coal Mine in Bangladesh: constraints from BEM simulations

Islam, M.R. and Shinjo, R.

International Journal of Coal Geology ( その他の出版社 )  79   115 - 130   2009 [ Peer Review Accepted ]

Type of publication: Research paper (scientific journal)

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Numerical simulation of stress distributions and displacements around an entry roadway with igneous intrusion and potential sources of seam gas emission of the Barapukuria coal mine, NW Bangladesh

Islam, M.R. and Shinjo, R.

International Journal of Coal Geology ( その他の出版社 )  78   249 - 262   2009 [ Peer Review Accepted ]

Type of publication: Research paper (scientific journal)

Submarine, across-arc normal fault system in the southwest Ryukyu arc triggered the 1771 tsunami hazard?: field evidences from multibeam survey and in-situ observation by ROV

Matsumoto, T., Shinjo, R., Nakamura, M., Doi, A., Kimura, M., Ono, T. and Kubo, A.

Polish J. Environ. Stud. ( その他の出版社 )  18   123 - 129   2009 [ Peer Review Accepted ]

Type of publication: Research paper (scientific journal)

Geology and Petrology of the Nishi and Fudenzaki Formations of the Aguni Group, Aguni Island, the Central Ryukyu Arc : Petrogenetic Relationship between the Andesites and Dacites

Usami　Ken,Kato　Yuzo

No.60 (1995/9) ( 琉球大学理学部 )  ( 60 ) 27 - 50   2008.03

Type of publication: Research paper (bulletin of university, research institution)

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The late Miocene volcanic rocks of the Aguni Group range from basalt to rhyolite, and have a pronounced compositional gap between 57 and 69 wt.% SiO_2. Sr isotopic ratios for a dacite lava from the Nishi Formation (0.70463) and a gabbroic fragment from the Fudenzaki Formation (0.70455) are similar to those of the basalt-andesite suite (0.70452-0.70466). Both major- and trace-element variations from andesite to dacite are explainable in terms of fractional crystallization involving removal of the observed phenocryst phases in the evolved volcanic rocks. The Rare Earth Elements (REE) patterns of gabbroic fragments appear to coincide with the pattern of cumulate expected from fractional crystallization. A shallow composition-temperature slope of cotectic involving amphibole-bearing gabbroic assemblages is responsible for the development of bimodality between the andesites and dacites. （管理者追加）リポジトリ登録情報を移行しました。確認のうえ、加除修正をしてください。

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Petrology and petrogenesis of volcanic rocks from the Uegusukudake Formation in Kume-jima, central Ryukyu Arc

Shinjo　Ryuichi,Kato　Yuzo

No.77 (2004/3) ( 琉球大学理学部 )  ( 77 ) 81 - 103   2008.03

Type of publication: Research paper (bulletin of university, research institution)

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Major and trace element concentrations and Sr and Nd isotopic ratios are presented for volcanic rocks from the Uegusukudake Formation (～$3-2 Ma) in Kume-jima, central Ryukyu Arc, in order to understand the origin of varieties of erupted magmas. The Uegusukudake Formation is mainly composed of lavas and pyroclastic rocks with subordinate dikes. Volcanic rocks collected from lavas and dikes are grouped into four types based on their petrological characteristics: (1) picrite basalt (PB); (2) aphyric, tholeiitic basalt and basaltic andesite (A-TH); (3) porphyritic, tholeiitic basaltic andesite (P-TH); and (4) porphyritic, calc-alkaline basaltic andesite and andesite (CA), in ascending order. The PB sample is isotopically distinct in having significantly low ^<87>Sr/^<86>Sr (0.7035) and high ^<143>Nd/^<144>Nd (0.51290) compared with the other three types. The A-TH, P-TH, and CA types have similar isotopic compositions (^<87>Sr/^<86>Sr=0.7045-0.7054, ^<143>Nd/^<144>Nd=0.51270-0.51284) and show rather coherent incompatible trace element patterns. These results suggest that the three types of magmas were derived from a similar source material, distinctive from the source of the PB magma. A slight difference in isotopic and trace element ratios (La/Sm and La/Yb) among the three types can be attributed to the different degree of contributions of crustal assimilation. Geochemical variations within the A-TH type rocks can be explained by fractional crystallization, and the variation of the CA type is considered to have resulted from internal hybridization within a single magma reservoir. For the variation of the P-TH type, plagioclase accumulation is inferred to have played a dominant role. （管理者追加）リポジトリ登録情報を移行しました。確認のうえ、加除修正をしてください。

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Petrochemical evidence for diversity of magma compositions at the northwestern Ethiopian volcanic province

Shinjo　Ryuichi,

No.78 (2004/9) ( 琉球大学理学部 )  ( 78 ) 251 - 266   2008.03

Type of publication: Research paper (bulletin of university, research institution)

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Petrographic characteristics and whole-rock major and trace element data are presented for the Bure volcanic rocks from the northwestern Ethiopian plateau of East Africa continental flood basalt province, to investigate the processes that involved in the genesis of the erupted magma and its source composition during plume-induced continental rifting. The Bure area is mainly composed of stratified basalts, recent basalts, scoria cones and trachyte plugs. The successions of the erupted basalts are from transitional tholeiites to alkaline basalts. The transitional tholeiites have higher Zr/Nb (8.88-21.86) and Rb/Nb (0.66-1.87) than those of the alkaline (Zr/Nb=2.19-6.21, Rb/Nb=0.26-0.74), indicating that they are originated from distinct magma sources. The compositional variation in the transitional tholeiites cannot be explainable in terms of fractional crystallization of common (or similar) primary magma; instead it reflects the involvement of various mantle and crustal components in their petrogenesis. By contrast, the variation in the alkali suite can be explained by dominant fractional crystallization process of OIB-like primary basalts that derived from the Afar mantle plume. The strong lithospheric signature observed in the transitional tholeiites suggests pronounce interaction between the Afar plume and the lithosphere at the initial stage of continental break-up. （管理者追加）リポジトリ登録情報を移行しました。確認のうえ、加除修正をしてください。

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Geology of the Shar and Bulen areas, northwestern Ethiopia: Preliminary result

Negussie　Aweke,Shinjo　Ryuichi

No.79 (2005/3) ( 琉球大学理学部 )  ( 79 ) 27 - 42   2008.03

Type of publication: Research paper (bulletin of university, research institution)

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Geological assessment of Shar and Bulen areas, northwestern Ethiopia indicates distinctive rock associations consisting of pelitic and pssamitic sediments that are interbedded with volcanic rocks and linear belt of mafic-ultramafic rocks. These volcano-sedimentary associations signify interchanges of sedimentary process and volcanic activity. Deposition is interpreted to have occurred within a marginal to shallower marine setting. The rocks were subjected to different phases of deformation and were metamorphosed to greenschist facies. Structural investigation indicates that the area underwent at least three phases of deformation (D_1-D_3) with pre-, syn- and post- kinematic granitic intrusions. The volcano-sedimentary association together with mafic-ultramafic rocks can be interpreted as an arc/continent suture zone. （管理者追加）リポジトリ登録情報を移行しました。確認のうえ、加除修正をしてください。

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Data report: Pb isotope compositions of sediment from the eastern flank of Juan de Fuca Ridge

Noguchi, T., Shinjo, R. and Oomori, T.

Proc. IODP, 301: College Station, TX ( その他の出版社 )  301   2008 [ Peer Review Accepted ]

Type of publication: Research paper (scientific journal)

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Rethinking geochemical feature of the Afar and Kenya mantle plumes and geodynamic implications

Meshesha, D. and Shinjo, R.

J. Geophys. Res. ( その他の出版社 )  113   B09209   2008 [ Peer Review Accepted ]

Type of publication: Research paper (scientific journal)

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Propagators and ridge jumps in a back-arc basin, the West Philippine Basin

Deschamps, A., Shinjo, R., Matsumoto, T., Lee, C.-S., Lallemand, S.E., Wu, S. and Scientific party of KR03-04 and KR04-14 cruises

Terra Nova ( その他の出版社 )  20   327 - 332   2008 [ Peer Review Accepted ]

Type of publication: Research paper (scientific journal)

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Was there Jurassic paleo-Pacific subduction in South China?: Constraints from 40Ar/39Ar dating, elemental and Sr-Nd-Pb isotopic geochemistry of the Mesozoic basalts

Chen, C.H., Lee, C.Y. and Shinjo, R.

Lithos ( その他の出版社 )  106   83 - 92   2008 [ Peer Review Accepted ]

Type of publication: Research paper (scientific journal)

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Origin of sapphirine-bearing garnet-orthopyroxene granulites: possible hydrothermally altered ocean floor

Baba, S., Shinjo, R. and Windley, B.F.

Polar Science ( その他の出版社 )  2   87 - 107   2008 [ Peer Review Accepted ]

Type of publication: Research paper (scientific journal)

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Crustal contamination and diversity of magma sources in the northwestern Ethiopian volcanic province

Meshesha, D. and Shinjo, R.

J. Mineral. Petrol. Sci. ( その他の出版社 )  102   272 - 289   2007.04 [ Peer Review Accepted ]

Type of publication: Research paper (scientific journal)

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Determination of uranium in pore water from coastal sediment by standard addition ICP-MS analysis

Armid, A., Ohde, S., Shinjo, R. and Toki, T.

J. Radioanal. Nucl. Chem. ( その他の出版社 )  275   233 - 237   2007.04 [ Peer Review Accepted ]

Type of publication: Research paper (scientific journal)

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Chemical impact of the acidic red soil on seawater

Kombo, M.M., Bakari, S.S., Shinjo, R. and Tokuyama, A.

Galaxea, JCRS ( その他の出版社 )  8   13 - 23   2006.04 [ Peer Review Accepted ]

Type of publication: Research paper (scientific journal)

Petrology of Aoso volcano, northeast Japan arc: temporal variation of the magma feeding system and nature of low-K amphibole andesite in the Aoso-Osore volcanic zone.

Toya, N., Ban, M. and Shinjo, R.

Contrib. Mineral. Petrol.DOI 10.1007/s00410-004-0621-z. ( その他の出版社 )  148   566 - 581   2005.03 [ Peer Review Accepted ]

Type of publication: Research paper (scientific journal)

Geochemical constraints for the genesis of post-collisional magmatism and the geodynamic evolution of the northern Taiwan region.

Wang, K.-L., Chung, S.-L., O'Reilly, S.Y., Sun, S.-S., Shinjo, R. and Chen, C.-H.

J. Petrol. ( その他の出版社 )  45   975 - 1011   2004.03 [ Peer Review Accepted ]

Type of publication: Research paper (scientific journal)

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