An Integration Of Geophysical Attributes For Evaluating The Santonia Effects On Aquifer Bed Units In Umuoma Nzerem Community, Imo State, Nigeria

Abstract

This study evaluates the impact of the Santonian orogeny on aquifer characteristics in Umuoma Nzerem, Imo State, Nigeria. The area lies within the transitional zone between the Anambra Basin and Benue Trough, where tectonic deformation during the Santonian event resulted in structural reconfiguration and diagenetic cementation of the Ajali Sandstone. Electrical resistivity surveys were conducted to characterize aquifer properties and identify suitable drilling zones. Field observations revealed cement-like dust from shallow to deeper drilling intervals, indicative of lithified or over-compacted formations rather than anthropogenic contamination. These diagenetically cemented zones reduce aquifer porosity and permeability, limiting groundwater storage and flow. Results highlight significant geological control on aquifer productivity and variability, controlled by tectonic deformation and diagenesis. Identifying unconsolidated sandstone intervals is crucial for sustainable groundwater abstraction. The study concludes that cementation linked to the Santonian deformation event is a major hydrogeological constraint in the area. Targeted drilling in structurally favorable zones is recommended to enhance borehole success rates and optimize groundwater resource development.