Rock Density of Some Selected Rocks: A case study of some selected rocks in Ado Ekiti Southwestern Nigeria

Abstract

Rock density is a critical parameter in geological and geophysical investigations, particularly for gravity anomaly interpretation and subsurface characterization. This study determined representative density values for the major lithological units of the Precambrian Basement Complex underlying Ado-Ekiti, Southwestern Nigeria, to provide a reliable density model for geological and geophysical applications. A total of 680 rock samples comprising charnockite, gneiss, quartzite, migmatite, and older granite were collected from representative outcrops and analyzed using the Archimedes principle following oven drying. Statistical analyses were employed to evaluate density distributions and establish mean density values for each lithology. The results revealed mean dry densities of 2.80 g/cm³ for charnockite, 2.70 g/cm³ for gneiss, 2.68 g/cm³ for older granite, and 2.58 g/cm³ for quartzite, with charnockite exhibiting the highest density and quartzite the lowest. Frequency distributions displayed bimodal patterns in several lithologies, reflecting mineralogical and compositional heterogeneity. The overall mean density of the basement rocks was determined as 2.69 g/cm³, representing a characteristic density value for the study area. The established density model provides a robust framework for gravity anomaly interpretation, geological mapping, and subsurface investigations within Ado-Ekiti and comparable Precambrian basement terrains.