Oni, Samuel: Paleocene Limestone

Limestone is a mineral deposit in Nigeria in much abundance which occurs only in the sedimentary basins.High grade limestone is a general term that refers to rocks which contain more than 85% percent calcium or calcium-magnesium carbonates and according to Todd (1966), the Ca/Mg ratio must be greater than 39%. A geochemical study of Onigbedu limestone of the post cretaceous group of Paleocene era as exposed at blast site of Purechem Cement Company was carried out. The aim of this researchis to chemically evaluate calcium-oxide content, the deposits suitability for cement manufacture, production of several other domestic usable products and projecting the paleo-depositional history of the deposit using its major and trace elements composition. The chemical compositions of the limestone exposed in the quarry were determined using hand held Thermo-scientific XRF analyzer. Results showed that the paleoenvironment of deposition is a very shallow marine environment in high temperature, high evaporation and high salinity environment as postulated by several authors.Results showed that the paleoenvironment of deposition is a very shallow marine environment in high temperatures.