Mineralogy and Geochemical Characteristics of Clay Occurrence in Central Bida Basin Northwestern Nigeria

Abstract

The Bida basin is bounded to the north and south by the Precambrian basement rocks. The largest portion of the basin occurred at the southern half of Niger State, which formed the central portion of the basin that constitutes the study area. Clay of varying mineralogical and chemical compositions has been reported to have occurred as sedimentary clays within varying lithological units and at various locations of the Bida basin. Geochemical analytical methods employ is Inductively Coupled Plasma mass spectrometer (ICP – MS) and X-ray Diffraction (X-RD). Field work revealed seven clay occurrences at different stratigraphic formations. Mineral compositions of the study clay account for Kaolinite, muscovite/illite and anatase. Geochemical results revealed SiO₂ ranging between 54.91wt% and 87.37wt%, and moderately high Al₂O₃ ranging between 7.4wt% and 29.67wt%, and a low value of Fe₂O₃ ranging between 1.13wt% and 7.11wt%. However, the samples are low in CaO, Na₂O and K₂O except for Shegba clay which is slightly higher in K₂O. Trace and rare elements suggested felsic character in the nature of source materials of the kaolin.