Ground Based Gravimetric for the Detection and Depth Mapping of Subsurface Geological Features of Ilesha, Southwest Nigeria

This paper presents the analysis and interpretation of ground gravity data of Ilesha and its environs in southwest Nigeria. The work is aimed at complementing researches done in this locality with magnetic survey for both ground and airborne data. The ground gravity data of the area within latitude (۷o۳۰ˈ - ۸o۰۰ˈ) N and longitude (۴o۳۰ˈ - ۵o۰۰ˈ) E was acquired from the Nigerian Geological Survey Agency (NGSA). The data set was interpreted qualitatively and quantitatively to derive information about the structural features of the subsurface. The qualitative analysis was carried out by filtering techniques and interpreted by making visual inspection of grids to map low and high-density regions. Equally, the quantitative interpretation employed were Euler ۳-D deconvolution and Source Parameter Imaging (SPI) methods, which revealed the boundary, location and depth of gravity sources defining the study area. The minimum and maximum depths of anomalous sources obtained are ۷۸۱.۴۳ m and ۴,۲۰۸.۸۵ m, while the average depth to the target is ۲,۵۳۷.۲۱۵ m. The average depth of gravity anomalous sources estimated predicted the area to hold a worthy prospect for the accumulation of near surface rock minerals.

Keywords:

Density , Filtering , Gravity , qualitative , quantitative