Geochemical Evaluation of Arimogija-Okeluse Limestones, Eastern Dahomey Basin, Southwestern Nigeria

Abstract

10 representative samples of limestone were collected from the Arimogija-Okeluse Axis of the Dahomey Basin and subjected to X-Ray Fluorescence analysis. Major and Trace elements were used to classify and predict the depositional environment of Arimogija-Okeluse limestone.The results for the major oxide composition revealed that CaO content ranges from 47.6-52.31% with a mean value of 50.06%. SiO2 concentration varies from 1.94-5.24% with an average of 3.36%. Fe2O3. MgO, and Al2O3 contents have mean values of 1.702%, 1.52%, and 1.09% respectively. Other oxides; Na2O, P2O5, K2O and TiO2 are low in concentration. The Loss on Ignition also varies from 38.9-41.8 with a mean value of 40.43% suggesting a high carbonate content for the limestone. Standard Ca/Mg and Mg/Ca ratios varies from 25.87-37.63 and 0.03-0.04 with a mean of 33.31and 0.031 respectively. The high strontium content reveals a high saline environmental condition of formation for the limestone.The results obtained, however showed that the Arimogija-Okeluse limestone is a Magnesian limestone type deposited in a shallow marine environment and suitable for cement production.