AQUIFER CHARACTERIZATION USING THE NEW ADMT (AUDIO MAGNETOTELLURIC) METHOD: A CASE STUDY OF KWARA STATE COLLEGE OF EDUCATION, ILORIN, SOUTHWESTERN NIGERIA

Abstract

The New ADMT equipment of Electromagnetic Method (Audio Magnetotelluric Method) was used in 
characterizing the aquifer zones within the Kwara State College of Education, Ilorin. The ADMT data measured 
along seven profiles of 200m at inter profile distance of 25m and interstation separation of 10m were done using the 
16 electrodes instrument. The ADMT data revealed features significant to groundwater potential as conductive 
zones in the images obtained. Three distinct zones were delineated based on the current density distribution. The 
fresh basement terrain corresponds to the highly resistive zone indicated by red colour. The intermediate zone has 
current density value range of -20 to 25 typical of rocks and soil component which are slightly resistive to slightly 
conductive and corresponds to the partially saturated units, having color rage from blue to yellow. The third zone is 
highly conductive with current density value greater than 30 which includes the saturated weathered or fractured 
basement, fault zones, clay units and saturated sandy units within the study area, this zone is indicated with purple to 
blue colour. This survey has helped in detecting sites that are suitable for groundwater exploration by identifying 
water bearing fractures and weathered zones in the study area. The areas with high conductivity correspond with 
conductive overburden material such as clayey soil, saturated soil, water filled fractures and faults or weathered 
zone within the basement.