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Title: Petrochemical and Tectonogenesis of Granitoids in the Wuyo-Gubrunde Horst, Northeastern Nigeria: Implication for Uranium Enrichment

Abstract

The Wuyo-Gubrunde Horst in the northeastern Nigeria consists of migmatite gneiss, unaltered, altered, and sheared porphyritic granites, pegmatites, aplites, basalts, and sandstone. Uranium has been reported in rhyolite, sheared rocks, and sandstone within the area. The petrogenesis of the granitoids and associated rocks in the area was evaluated in the light of new geochemical data, which showed that the U content of altered porphyritic granite is highest and hydrothermal-related. The granitoids are metaluminous, sub-alkaline, and S-type granite, and have evolved by partial melting of crustal material emplaced at moderate depth of 20–30 km in a syn-to late-collisional within-plate tectonic setting. The negative Eu/Eu* anomaly and high (La/Yb){sub N} ratio of the granitoids indicate magma fractionation. The low SiO{sub 2} (<53%) and high Fe{sub 2}O{sub 3} (10%) of the altered porphyritic granite compared to other similar rock units suggest pervasive alteration. The associated basalts are tholeiitic, emplaced within continental plate tectonic setting, and enriched in Ni, V, Nb, Sr, and light rare earth elements, and they have SiO{sub 2}, Fe{sub 2}O{sub 3}, V, Th, and Co contents that are similar to those of the altered porphyritic granites. The U occurrence in the Wuyo-Gubrunde Horst is believed to be sourced from themore » adjoining Bima sandstone in the Benue Trough, which locally contains carbonaceous zones with anomalously high concentrations of U. The Fe{sup 2+}/Fe{sup 3+} redox fronts formed by alteration of the iron-rich basalts provided the requisite geochemical barrier for U-bearing hydrothermal fluid, causing enrichment of U leached and mobilized from the sandstone through fractures in the rocks.« less

Authors:
;  [1]
  1. University of Ibadan, Department of Geology (Nigeria)
Publication Date:
OSTI Identifier:
22612703
Resource Type:
Journal Article
Resource Relation:
Journal Name: Natural Resources Research (New York, N.Y.); Journal Volume: 25; Journal Issue: 2; Other Information: Copyright (c) 2016 International Association for Mathematical Geosciences; http://www.springer-ny.com; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
58 GEOSCIENCES; APLITES; BASALT; CONCENTRATION RATIO; ENRICHMENT; FRACTIONATION; GEOCHEMISTRY; GNEISSES; IRON IONS; IRON OXIDES; ISOTOPE SEPARATION; LEACHING; MAGMA; NIGERIA; PEGMATITES; PETROGENESIS; PLATE TECTONICS; RARE EARTHS; RHYOLITES; SANDSTONES; SILICON OXIDES; URANIUM

Citation Formats

Bolarinwa, Anthony Temidayo, E-mail: atbola@yahoo.com, and Bute, Saleh Ibrahim. Petrochemical and Tectonogenesis of Granitoids in the Wuyo-Gubrunde Horst, Northeastern Nigeria: Implication for Uranium Enrichment. United States: N. p., 2016. Web. doi:10.1007/S11053-015-9279-7.
Bolarinwa, Anthony Temidayo, E-mail: atbola@yahoo.com, & Bute, Saleh Ibrahim. Petrochemical and Tectonogenesis of Granitoids in the Wuyo-Gubrunde Horst, Northeastern Nigeria: Implication for Uranium Enrichment. United States. doi:10.1007/S11053-015-9279-7.
Bolarinwa, Anthony Temidayo, E-mail: atbola@yahoo.com, and Bute, Saleh Ibrahim. 2016. "Petrochemical and Tectonogenesis of Granitoids in the Wuyo-Gubrunde Horst, Northeastern Nigeria: Implication for Uranium Enrichment". United States. doi:10.1007/S11053-015-9279-7.
@article{osti_22612703,
title = {Petrochemical and Tectonogenesis of Granitoids in the Wuyo-Gubrunde Horst, Northeastern Nigeria: Implication for Uranium Enrichment},
author = {Bolarinwa, Anthony Temidayo, E-mail: atbola@yahoo.com and Bute, Saleh Ibrahim},
abstractNote = {The Wuyo-Gubrunde Horst in the northeastern Nigeria consists of migmatite gneiss, unaltered, altered, and sheared porphyritic granites, pegmatites, aplites, basalts, and sandstone. Uranium has been reported in rhyolite, sheared rocks, and sandstone within the area. The petrogenesis of the granitoids and associated rocks in the area was evaluated in the light of new geochemical data, which showed that the U content of altered porphyritic granite is highest and hydrothermal-related. The granitoids are metaluminous, sub-alkaline, and S-type granite, and have evolved by partial melting of crustal material emplaced at moderate depth of 20–30 km in a syn-to late-collisional within-plate tectonic setting. The negative Eu/Eu* anomaly and high (La/Yb){sub N} ratio of the granitoids indicate magma fractionation. The low SiO{sub 2} (<53%) and high Fe{sub 2}O{sub 3} (10%) of the altered porphyritic granite compared to other similar rock units suggest pervasive alteration. The associated basalts are tholeiitic, emplaced within continental plate tectonic setting, and enriched in Ni, V, Nb, Sr, and light rare earth elements, and they have SiO{sub 2}, Fe{sub 2}O{sub 3}, V, Th, and Co contents that are similar to those of the altered porphyritic granites. The U occurrence in the Wuyo-Gubrunde Horst is believed to be sourced from the adjoining Bima sandstone in the Benue Trough, which locally contains carbonaceous zones with anomalously high concentrations of U. The Fe{sup 2+}/Fe{sup 3+} redox fronts formed by alteration of the iron-rich basalts provided the requisite geochemical barrier for U-bearing hydrothermal fluid, causing enrichment of U leached and mobilized from the sandstone through fractures in the rocks.},
doi = {10.1007/S11053-015-9279-7},
journal = {Natural Resources Research (New York, N.Y.)},
number = 2,
volume = 25,
place = {United States},
year = 2016,
month = 6
}
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