Petrology and Mineral Potentials of the Zaranda Complex, Northeastern Nigeria

Abstract

The determination of geochemical and mineralogical composition of rocks that underlie The Zaranda Complex became necessary for the interpretation of the petrogenesis and protoliths of rocks in the area. Eleven (11) representative rock samples were selected for thin section petrography and mineralogy (XRD) and ten (10) samples for bulk rock geochemical analysis (XRF). The results reveal that the dominant intrusive rocks in the area are quartz veins, pegmatites, latite dyke and younger granite emplaced within schist, syenites, gneisses, migmatites and bauchites host rocks. The gneisses and granites are leucocratic consisting predominantly of quartz, plagioclase and subordinate amount of muscovites while the latite is dark grey, fine grained and texturally ophitic and consists dominantly of quartz, albite, sanidine and garnet. Two varieties of gneisses were recognized: banded and feldsparthic gneisses. The gneisses, migmatites and bauchites are dominated by SiO₂ in the range of 63% - 79%. The result of Harker variation diagrams of the area suggests an intensed fractional crystallization habit of the crystallizing fluids. The area has high K affinity. Based on the Frost Classification Scheme of granitic rocks, the area is predominantly per-aluminous, alkalic-calcic with ferroan affinity. The rocks of the Zaranda Complex are of sedimentary/metasedimentary source derived from partial melts of metagreywackes and they fall within S-type granites.