Occurrence and geochemistry of Nafada Gypsum, north-eastern nigeria

Abstract

Gypsum deposits occur in numerous locations within the Senonian Fika Shale at Nafada, northeastern Nigeria. Geologic investigations at Baro Winde and Wuro Dabo mines indicate the occurrence of three varieties of gypsum namely, Balatino laminated, Alabaster and Satin Spar. These are interlayered within shale and mudstone. Geochemical analyses of the gypsum deposits by X-ray spectrometric technique gave both mean compositions of 91.57, 95.53 and 92.48 wt % of CaSO4.2H2O; 0.53, 0.23, and 1.05 wt % Magnesia (MgO); 0.14, 0.09, and 0.48 wt % Alkalis (Na2O + K2O) and purity of 95.03, 96.01 and 93.02 % for Balatino laminated, Alabaster and Satin Spar, respectively. These parameters suggest high-grade gypsum, which is suitable for the manufacture of Portland cement.