MICROSTRUCTURAL INTERPRETATION OF THE GARNET-SILLIMANITE-BEARING GRANITE GNEISS OF IKARE AREA, SOUTHWESTERN NIGERIA

Oziegbe, Olubukola and Oziegbe, O. (2023) MICROSTRUCTURAL INTERPRETATION OF THE GARNET-SILLIMANITE-BEARING GRANITE GNEISS OF IKARE AREA, SOUTHWESTERN NIGERIA. Ife Journal of Science, 25 (1). 035-044.

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Abstract

This study presents microstructures from the granite gneiss of the Basement complex of southwestern Nigeria. The granite gneiss of Ikare area comprises of the mineral assemblage; garnet, biotite, K-feldspar, quartz, plagioclase, sillimanite and opaque minerals. K-feldspar porphyroblasts have cuspate interstitial quartz grains, also quartz grains are included in K-feldspar. Most K-feldspar grains are highly strained and in some cases are fractured. Prismatic and fibrolite-type sillimanite are both present. Biotite is closely associated with fibrolitetype sillimanite. Sillimanite was observed to mimic the foliation produced by biotite. K-feldspar is the dominant mineral and could have formed by the dehydration reaction of biotite + plagioclase + quartz + sillimanite " garnet + K-feldspar + melt. Microscopic structures such as strained feldspar grains, micro-fractures in Kfeldspar, simple twinning in K-feldspar, myrmekite, mimicking textures, microperthitic intergrowth and cuspate volumes of quartz surrounding K-feldspar are indicative of melt-bearing and solid-state deformation of regional metamorphic rocks.

Item Type:	Article
Uncontrolled Keywords:	Microperthitic intergrowth, Fibrolite, Myrmekite, Microcline.
Subjects:	Q Science > QH Natural history Q Science > QH Natural history > QH301 Biology Q Science > QR Microbiology
Divisions:	Faculty of Medicine, Health and Life Sciences > School of Biological Sciences
Depositing User:	ORIGBOEYEGHA
Date Deposited:	19 Jul 2024 13:58
Last Modified:	19 Jul 2024 13:58
URI:	http://eprints.covenantuniversity.edu.ng/id/eprint/18261

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