Petrographic, Mineralogical and Geochemical Characterization of Metacarbonate (Marble) Rocks from the Oreke Area, Southwestern Nigeria: Implications for Industrial Applications

Abstract

Metacarbonate rocks from the Oreke area were investigated in order to study their mineralogical and geochemical characteristics and evaluate their industrial potential. Petrographic examination, X-ray diffraction, and inductively coupled plasma mass spectrometry were employed to characterize representative samples of the white, whitish-grey, and dark marble varieties. The marbles are predominantly dolomitic and contain subordinate calcite, tremolite, phlogopite, sylvite, and graphite. Geochemical analyses reveal appreciable compositional variations among the three varieties. The average oxide composition of the Oreke marbles is characterized by major CaO and MgO contents, accompanied by subordinate SiO₂, Al₂O₃, Fe₂O₃, MnO, Na₂O, K₂O, TiO₂, and P₂O₅, with mean values of 28.24, 17.84, 10.64, 2.39, 3.11, 0.058, 0.331, 0.527, 0.808, and 0.289, respectively. The average loss on ignition is 35.55 wt. %, reflecting the substantial carbonate fraction of the deposit. The integrated mineralogical and geochemical evidence demonstrates that the Oreke marble deposit constitutes a valuable industrial resource with promising applications in the production of magnesium metal and magnesia, as well as in agronomy and other carbonate-based industries.

Keywords: Oreke marble, mineralogical characterization, petrography, industrial and agronomic applications.