Universal Journal of Geoscience Vol. 2(4), pp. 116 - 122
DOI: 10.13189/ujg.2014.020402
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Geology and Geochemistry of Zungeru Amphibolites, North Central Nigeria


Ako Thomas Agbor *
Department of Geology, School of Natural and Applied Sciences, Federal University of Technology, Minna, Nigeria

ABSTRACT

Basement rocks of Zungeru area consist of gneisses, schists, migmatites and intercalations of amphibolites and quartzites .This work involves detailed geological and geochemical investigation of Zungeru amphibolites so as to reveal their possible protolith. Field investigations show two petrographic types of the amphibolites on the basis of their textures, structures and mineralogy. They include the banded and massive types. The banded type is medium grained, strongly foliated and dark coloured rock while the massive type is fine to medium grained, dark-grey to black coloured with very weak foliations. Both types have been fractured due to deformation resulting in the development of joints and faults. Twelve representative samples of the amphibolites in the study area were collected and analyzed for major and trace elements using the Energy Dispersive X-Ray Fluorescence (EDX-RF) Spectrometer, Model: Minipal 4 at the laboratory of the National Geological Agency, Kaduna. However, only the major elements data was used for determination of the protolith of the amphibolites. The analytical results show that the Zungeru amphibolites contain on average 50.15% SiO2,12% Al2O3, 0.39% Na2O, 0.02% K2O, 9.41% CaO, 9.90% MgO, 0.02% MnO, 12.24% Fe2O3, 4.89% FeO, 0.5% TiO2, 0.10% P2O5 and 0.78% H2O. Various bivariate plots indicate that the precursors of the amphibolites are sedimentary. They are inferred to have been formed from metamorphism of decarbonated mixtures of pelitic sediments and calcite or dolomite. The occurrence of the amphibolites in association with quartzites further strengthened the fact that their origin is sedimentary and therefore referred to as para-amphibolites.

KEYWORDS
Amphibolites, Protholith, Bivariate Plots, Zungeru, Para-amphibolites, Basement Complex

Cite This Paper in IEEE or APA Citation Styles
(a). IEEE Format:
[1] Ako Thomas Agbor , "Geology and Geochemistry of Zungeru Amphibolites, North Central Nigeria," Universal Journal of Geoscience, Vol. 2, No. 4, pp. 116 - 122, 2014. DOI: 10.13189/ujg.2014.020402.

(b). APA Format:
Ako Thomas Agbor (2014). Geology and Geochemistry of Zungeru Amphibolites, North Central Nigeria. Universal Journal of Geoscience, 2(4), 116 - 122. DOI: 10.13189/ujg.2014.020402.