Classification and Nomenclature of the Sandstones of the Bama Ridge, Bornu Sub Basin, North Eastern Nigeria

The Bama Ridge is a long, narrow and prominent morphological feature lying roughly NW to SE on top of the Quaternary Chad Formation in the Bornu sub basin. Section logging revealed the predominance of sandstone lithofacies, from which samples were obtained for nomenclature. Granulometric analyses of samples analysed show an overwhelming degree of textural maturation, characterized by extremely low percentages of matrix. Thin section microscopy and quantitative estimation by point counting indicate Quartz richness with significant amount of feldspar. However, rock fragment and other mineralogical suites are insignificant. Thus, these sandstones are Quartzose and mineralogically immatured. Nomenclature plots, employing the schemes of Mc Bride (1963) and Dott (1964) indicate that the sandstones of the facies of the Bama Ridge are predominantly Arkosic Arenites sandstones which are texturally matured but mineralogically immatured.