Mineralogical and Geochemical Characterization ofYoungerGranites fromParts of Jos, Northce

Abstract

The quest to understand the different geological setting within the Nigerian Basement Complex for their mineralization potentials led to this study which was aimed at determining the mineralogical and geochemical characterization of some granitic rocks within Jos, North central Nigeria to ascertain their textural features, constituent minerals, petrogenesis and mineralization potentials. Twenty representative granitic rock samples were collected, prepared and analyzed for textural properties through field observations while mineralogical compositions and major elements, trace elements and REEs concentrations were analysed for using the petrographic microscope, XRD and ICP-MS respectively. The granitic rocks observed were dominantly porphyritic biotite granites with pegmatitic and quartz vein intrusions exhibiting varying degree of joint orientations trending dominantly in the NWSE and NE-SW direction while mineralogical compositions showed the study area had dominantly biotite granites with minerals including; quartz (20-40%), plagioclase (5-15%), microcline (10-30%), orthoclase (10-25%), muscovite (15-30%), biotite (10-25%) and opaque minerals (5-30%). Results from whole rock geochemistry were used to classify these granitic rocks as alkali-calcic and peralkaline, indicative of felsic igneous rocks with higher Na2O (2.85-4.19%) +K2O (2.73-5.84%) than Al2O3(9.26-14.57%); Within Plates Granites (WPG) indicating formation within the plates and higher Light Rare Earth Elements, lower Heavy Rare Earth Elements with a negative Eu anomaly (0.33-2.45ppm) implying moderate fractionation and preservation of alkaline and plagioclase feldspar. There was also a significant abundance of Rb146-633ppm and Zr 316-858ppmcompared with their Average Crustal Abundance valuesof Rb 170ppm and Zr 309ppm and areas with anomalous concentrations were identified as possible mineralization zones.

Publication Info:

Author: Mustapha, S.O.1,3*, Olatunji,A.S.1,2,Ajayi, F.F.1,2and Isibo

Volume: 59

Issue: September

Published By: Journal of Mining and Geology Vol. 59(2) 2023. pp. 167 - 179, 2023-09-01