Geosciences-Scholarly Publications

Permanent URI for this collection

https://ir.unilag.edu.ng/handle/123456789/3958

Browse

Recent Submissions

Now showing 1 - 5 of 107
  • Item
    Open Access
    Titanite-Ilmenite Assemblage in Granodiorite of Wasimi, Southwestern Nigeria
    (Development Journal of Science and Technology Research (DJOSTER), 2023-01) Oziegbe, E. J.; Oziegbe, O.; Kayode, O. T.
    Mineral assemblage observed is amphibole + biotite + plagioclase + quartz + titanite + ilmenite + apatite. Titanite occur as anhedral grains interstitial between biotite and plagioclase feldspars, intergrown with amphibole (or as inclusion) and biotite (or replacing it). Also, anhedral titanite forms reaction rim around ilmenite. Amphiboles have sieve textures with inclusions of plagioclase, titanite, ilmenite and quartz. In addition, amphibole forms reaction rim around biotite, plagioclase and quartz. Two sets of plagioclase were identified, Plagioclase 1 occur as inclusion in biotite and amphibole, while Plagioclase 2 mantles both amphibole and biotite. Anhedral quartz occur as interstitial grains in contact with amphibole and plagioclase, and in some cases mantles plagioclase feldspar. Textural observations made on the rock strongly suggest that Plagioclase 1 could have supplied Ca, while ilmenite loses its FeO to the formation of titanite rims and subsequent formation of biotite. Biotite could have taken K2O and FeO and Plagioclase 2 enriched in albitic component. The reaction rim of amphibole on most of the other minerals is an indication that amphibole formed in the late stage of crystallization.
  • Item
    Open Access
    Petrographic Interpretation of Charnockitic rocks from Osuntedo and Wasimi, Southwestern Nigeria
    (Development Journal Of Science and Technology Research (DJOSTER), 2023-06) Oziegbe, E. J.; Oziegbe, O.
    Samples of charnockitic rocks from Osuntedo and Wasimi were subjected to petrographical analysis to determine the mineral present and the textural relationship of the mineral assemblage. It was observed that the charnockitic rocks contain pyroxene, biotite, amphibole, plagioclase feldspar, orthoclase and quartz with apatite and titanite present as accessory mineral. The textural relationship shows pyroxene included in biotite, and biotite mantling pyroxene. Also, amphibole reaction rims were noted around pyroxene, biotite, plagioclase and quartz. In addition, there were inclusions of euhedral apatite in biotite, antiperthite is surrounded by orthoclase feldspars. Plagioclase feldspar show zoning and bent twin lamellae. The sequence of crystallization of minerals follows the order; pyroxene, biotite and plagioclase, with amphibole showing a late appearance. The textural relationship of the minerals in the charnockitic rocks of Wasimi and Osuntedo demonstrate that the rocks are of igneous origin. Charnockitic rock of Wasimi contain more quartz compared to that of Osuntedo.
  • Item
    Open Access
    MICROSTRUCTURAL INTERPRETATION OF THE GARNET-SILLIMANITE- BEARING GRANITE GNEISS OF IKARE AREA, SOUTHWESTERN NIGERIA
    (Ife Journal of Science, 2023) Oziegbe, E. J.; Oziegbe, O.
    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 fibrolite-type 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 K-feldspar, 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
    Open Access
    EVALUATION OF SURFACE WATER-GROUNDWATER MIXING DYNAMICS IN A SHALLOW COASTAL AQUIFER USING INTEGRATED GEOPHYSICAL AND GEOCHEMICAL METHODS
    (Journal of Earth and Atmospheric Research, FUTA, Akure, 2020) Folorunso, A. F; Oloruntola, M.O; Agbaje, A.O
    This research work evaluates the dynamics of surface water-groundwater mixing using an open-ended Lake of Ugbo-Nla and the adjoining groundwater of the shallow coastal wells as a prototype study of surface water–groundwater interaction in coastal environment. Ten (10) surface water samples were collected from the lake at different positions using research boat while another ten (10) groundwater samples were collected from different shallow wells within the community opposite to the sea. The water samples were analysed using Atomic Absorption Spectroscopy (AAS) to determine the elemental concentrations. In addition, three Electrical Resistivity Tomography (ERT) profiles were equally established along the coast of the surface water body land-ward. Analysis of trace and major elemental compositions of water samples from the two water bodies reveal possible interaction between them. The ERT data also corroborate this interaction by showing low resistive zones at depth equivalent to the depth of the coastal shallow wells. Structure that mimic flow path was mapped out under profile 3 with high proximity to the surface water. The study has shown that active interaction exists between surface and underground water.
  • Item
    Open Access
    Hydro-geophysical mapping of occurrences and lateral continuity of aquifers in coastal and landward parts of Ikorodu, Lagos, Southwestern Nigeria
    (International Journal of Energy and Water Resources, Springers, 2019) Oloruntola, M.O; Adeyemi, G.O; Bayewu, O.O; Obasaju, D.O