Probable impart of the Geology, Mineralogy and Chemical Composition of Rocks on the Stability of Minna-Lambata Road

Abstract

The geology, chemistry and mineralogical composition of rocks along Lambata-Minna road were investigated with the view of understanding the probable impact of the rocks on the performance of the road. The methodology included geological field mapping and laboratory analyses that involved x-ray diffraction and x-ray fluorescence. The study reveals that the road is underlain by migmatite, marble, schist, granodiorite, gneiss and poorly fractured granite. The difractograms show that the minerals that make up are albite, cristabalite, siderophylite, graphite, nacaphite, cancrinite, wulfrenite, muscovite, vallerite, berlinite, ferrosite, cristabalite, annite-syn, sodalite, quartz, and aluminium sillicate minerals. The banded gneiss (around Bunu) and granodiorite (around Pago) show very little presence of quartz and highly rich in mafic minerals. The abundant oxides in the rocks are in the order SiO2> AlO3> Tio2 >Fe2O3> Cao >K2O> MgO >Na2O. Most of these minerals are susceptible to weathering and leaching. The leaching could lead to the removal of the bases from the weathering system and the formation of clay minerals such as kaolinite, illite and montmorillonite. These secondary minerals are liable to swelling and shrinkage during the wet and dry seasons that could lead to the poor performance of the road.