Series-2 (Nov. – Dec. 2025) Nov. – Dec. 2025 Issue Statistics
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| Paper Type | : | Research Paper |
| Title | : | Petrology And Structural Geology Of Gneissic Rocks In Bansan Osokom And Its Environs, Southeast Nigeria |
| Country | : | Nigeria |
| Authors | : | U. B. Abia || V. U. Ukaegbu || N. Egesi |
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: | 10.9790/0990-1306020109  |
Abstract: This study examined the petrology and structural characteristics of gneissic rocks around Bansan Osokom and its environs to clarify their metamorphic evolution and deformational history. Fourteen representative samples of medium- to coarse-grained migmatite gneisses (9) and granite gneisses (5) were analyzed petrographically. Modal composition indicates biotite–cordierite–garnet migmatite gneiss and biotite–cordierite granite gneiss as the major lithologies. The gneissic rocks display granoblastic to lepidoblastic textures defined by biotite, while garnet shows porphyroblastic.....
Keyword: Bansan Osokom: Cordierite; Peak metamorphism: Polyphase deformation: Retrogression
[1]
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R. Black, R. Caby, J. M. Bertrand, A. M. Boullier, R. Dars, And J. Lameyre. “Evidence For Late Precambrian Plate Tectonics In West Africa,” Nature, Vol 278 Issue 5704 Pp. 223–227, 1979.
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S. S. Dada. “Proterozoic Evolution Of Nigeria” In: Oshi, O. (Ed.), The Basement Complex Of Nigeria And Its Mineral Resources (A Tribute To Prof. M. A. O. Rahaman). Akin Jinad And Co., Ibadan, Pp. 29–44, 2006
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| Paper Type | : | Research Paper |
| Title | : | Aluminosity and Potassic Trends in Metasediments and Igneous Rocks of the Igarra Schist Belt: A Petrogenetic Approach Using Major Oxide Geochemistry |
| Country | : | Nigeria |
| Authors | : | Modestus Chijioke Ohaegbulem || Nonyelum Stella Iloanya || Uwem Bassey Abia || Michael Monday Inyang |
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: | 10.9790/0990-1306021017 |
Abstract: Aluminosity and Potassic Trends in Metasedimentary and Igneous Rocks in the Igarra Schist Belt have been investigated. This polycyclic schist belt represents a segment of the Proterozoic Nigerian Basement Complex characterized by metasedimentary and igneous lithologies that have undergone multiple deformational episodes and metamorphism. This study was carried out in order to investigate Aluminosity and potassic trends in representative granites, gneisses, and schists samples from the study area, employing major oxide geochemical data to infer magmatic and metamorphic processes. Potassic classification using K₂O vs. SiO₂ diagram distinguishes......
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Chappell, B.W., & White, A.J.R. (1974). Two contrasting granite types. Pacific Geology, 8, 173–174.
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Dada, S.S. (2006). Proterozoic evolution of Nigeria. In: The Basement Complex of Nigeria and its Mineral Resources. Akin Jinad & Co. Publications, pp. 29–44.
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Ekwueme, B.N., & Kroner, A. (1994). Rb–Sr geochronology and geochemistry of Precambrian rocks from Obudu Plateau, Southeastern Nigeria. Precambrian Research, 66(3–4), 269–286.
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| Paper Type | : | Research Paper |
| Title | : | Role Of Chamber Geometry And Crustal Heterogeneity In Stress Localization Around Pressurized Magma Chambers: Insights From Finite Element Models |
| Country | : | India |
| Authors | : | Pallab Jyoti Hazarika || Mukunda Saikia |
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: | 10.9790/0990-1306021825 |
Abstract: Excess pressure generated within a shallow crustal magma chamber causes deformation and rupture of the chamber wall rocks and produces magma driven fractures such as dikes and inclined sheets. The regional stress field around the chamber largely controls the evolution of such dikes. The presence of mechanical heterogeneity with varying stiffness of the alternate layers can modify the patterns and magnitudes of stress localization. Thus, understanding the underlain mechanisms of stress localization around a shallow crustal magma plumbing system is essential for interpreting volcanic deformation and assessing the eruption potential. By employing a series of finite element.....
Key Word: Magma plumbing system; Magma excess pressure; Young’s modulus; Dike and Inclined sheets; Volcanic eruption potential
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Barnett ZA, Gudmundsson A. Numerical Modelling Of Dykes Deflected Into Sills To Form A Magma Chamber. Journal Of Volcanology And Geothermal Research. 2014; 281:1–11.
[4].
Browning J, Gudmundsson A. Caldera Faults Capture And Deflect Inclined Sheets: An Alternative Mechanism Of Ring Dike Formation. Bulletin Of Volcanology. 2015; 77:1–13.
[5].
Browning J, Karaoğlu Ö, Bayer Ö, Turgay M, Acocella V. Stress Fields Around Magma Chambers Influenced By Elastic Thermo-Mechanical Deformation: Implications For Forecasting Chamber Failure. Bulletin Of Volcanology. 2021;83(7):1–13.