論文 - 新城　竜一

Damage zone propagation and support pressure estimation around two access tunnels of the Barapukuria coal mine in Bangladesh: a two-dimensional numerical modeling approach

Rafiqul, M. I, Faruque, M. O, Shinjo, R

International Journal of Advanced Geosciences   3   14 - 24   2015年 [ 査読有り ]

掲載種別: 研究論文（その他学術会議資料等）

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沖縄島の地質と成り立ち

新城竜一

琉球列島の自然講座 サンゴ礁・島の生き物たち・自然環境     150 - 159   2015年

掲載種別: 研究論文（その他学術会議資料等）

Determination of rare earth elements in small-volume seawater by off-line preconcentration system and inductively coupled plasma mass spectrometry

Shinjo　Ryuichi,

No.92 (2011/9) ( 琉球大学理学部 )  ( 92 ) 17 - 22   2011年11月

掲載種別: 研究論文（大学，研究機関紀要）

　概要を見る

An analytical method was developed for determining rare earth element (REE) concentrations in seawater using inductively coupled plasma mass spectrometry (ICP-MS). A relatively small-volume seawater sample (25 ml) was used for chemical separation. REE concentrations in 20-fold preconcentrated solution by an off-line preconcentration system were analyzed by ICP-MS with microflow nebulizer. The recoveries were mostly higher than 95%. To assess the analytical method, REE concentrations of the North Atlantic Surface Seawater (NASS-5), a seawater certified reference material, were measured with the proposed preconcentration procedure. Results obtained in this study are consistent with those of previous studies with good precision. （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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The tectonic stress field and deformation pattern of northeast India, the Bengal basin and the Indo-Burma Ranges: A numerical approach

Islam, M.S., Shinjo, R. and Kayal, J.R.

Journal of Asian Earth Sciences ( その他の出版社 )  40   121 - 131   2011年

掲載種別: 研究論文（学術雑誌）

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Pop-up tectonics of the Shillong Plateau in northeastern India: Insight from numerical simulations

Islam, M.S., Shinjo, R., Kayal, J.R.

Gondwana Research ( その他の出版社 )  (in press)   2011年

掲載種別: 研究論文（学術雑誌）

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Extracellular Matrix Protein in Calcified Endoskeleton: A Potential Additive for Crystal Growth and Design

Rahman, M.A., Fujimura, H., Shinjo, R. and Oomori, T.

Journal of Crystal Growth ( その他の出版社 )  (in press)   2011年

掲載種別: 研究論文（学術雑誌）

Geochemistry and geochronology of the mafic lavas from the southeastern Ethiopian rift (the East African Rift System): Assessment of models on magma sources, plume-lithosphere interaction and plume evolution

Shinjo, R., Chekol, T., Meshesha, D., Itaya, T. and Tatsumi, Y.

Contributions to Mineralogy and Petrology ( その他の出版社 )  (in press)   2011年

掲載種別: 研究論文（学術雑誌）

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New supplemental activator for lead isotope analysis with TIMS

Nohda, S., Wang, B.-S., You, C.-F. and Shinjo, R.

Geochemical Journal ( その他の出版社 )  (in press)   2011年

掲載種別: 研究論文（学術雑誌）

Barite geochemistry from hydrothermal chimneys of the Okinawa Trough: insight into chimney formation and fluid/sediment interaction

Noguchi, T., Shinjo, R., Ito, M., Takada, J. and Oomori, T.

Journal of Mineralogical and Petrological Sciences ( その他の出版社 )  106   26 - 35   2011年

掲載種別: 研究論文（学術雑誌）

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Report on RN97 Cruise by T/S Nagasaki Maru in the Southern Okinawa Trough

Motoyama　Isao,Nakamura　Mamoru,Takaki　Yasuaki,Nishida　Hideaki,Morii　Yasuhiro,Tanaka　Hitoshi

No.65 (1998/3) ( 琉球大学理学部 )  ( 65 ) 39 - 51   2010年02月

掲載種別: 研究論文（大学，研究機関紀要）

　概要を見る

As a part of the educational cruise (RN97 Cruise) for students of College of Science, University of the Ryukyus, by T/S Nagasaki Maru, the scientific survey is carried out during November 15 to 24, 1997. We dredge seafloor samples at several seaknolls which locate in the southern Okinawa Trough. Pumices and dacitic lava fragments are dredged. The rocks are quite fresh, and thus appear to be Quaternary eruptives, confirming the presence of continuous volcanic front from the northern Ryukyu Arc to the southern Ryukyu Arc. Surface sediment type varies depending on depositional settings. Sediments recovered by a grab sampler are composed of quartz sand in the continental shelf, biogenic calcareous sand in the Hokuto-Sekibi Bank and the Ryukyu Ridge, and mud in the Okinawa Trough. The radiolarian assemblage from the surface sediment sample in the Okinawa Trough is characterized by warm water species in accord with the oceanographic setting. （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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Hafnium isotope variations in Bure volcanic rocks from the northwestern Ethiopian volcanic province: a new insight for mantle source diversity

Meshesha, D. and Shinjo, R.

Journal of Mineralogical and Petrological Sciences ( その他の出版社 )  105   101 - 111   2010年

掲載種別: 研究論文（学術雑誌）

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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年

掲載種別: 研究論文（学術雑誌）

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年

掲載種別: 研究論文（学術雑誌）

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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年 [ 査読有り ]

掲載種別: 研究論文（学術雑誌）

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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年 [ 査読有り ]

掲載種別: 研究論文（学術雑誌）

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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年 [ 査読有り ]

掲載種別: 研究論文（学術雑誌）

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年 [ 査読有り ]

掲載種別: 研究論文（学術雑誌）

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年03月

掲載種別: 研究論文（大学，研究機関紀要）

　概要を見る

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年03月

掲載種別: 研究論文（大学，研究機関紀要）

　概要を見る

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年03月

掲載種別: 研究論文（大学，研究機関紀要）

　概要を見る

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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