Analysis of VLF-EM Data for Potential Cassiterite Mineralization Delineation Zone in Rafin-Bareda Area North-Western Nigeria

Abstract

VLF-EM geophysical technique was employed to delineate potential cassiterite mineralization at Rafin Bareda, Dutsen-Wai, Kubau Local Government area of Kaduna state, North Western, Nigeria. A total area of 3.025 km2 was covered along eleven (11) traverses separated by 25 m with a measurement interval of 10m taken in the East-West direction. The response of the in-phase component revealed various anomalous zones while Fraser-filtered plots of the in-phase peaked over the anomalous zones and the Karous-Hjelt filtered response of the in-phase correlates quite well with the results of the Fraser filtered data. In order to achieve the aim of the investigation, and since the VLF data was collected in the magnetic mode, enhancement procedures such as reduced to equator and analytical signal techniques were applied to the Fraser Filtered response of the In-phase component and correspondingly, Center for Exploration Targeting (CET), Source Parameter Imaging and Euler Deconvolution algorithms of the Oasis Montaj were successively employed to delineate potential mineralization zones and best locations for drilling productive cassiterite in the study area. Enhanced maps show linear features trending in the NE-SW and NW-SE directions with minor traces in the N-S direction. Most of the delineated zones of high analytical signal signature were either intercepted or flanked by the extracted lineament which is indicative of positive correlation between the extracted lineament and the high amplitude response of the analytical signal and also, validated the occurrence and positioning of the cassiterite mineral deposits is greatly controlled by the lineament system across the study area and the development of conductive zones of high apparent current with positive values reflects inferred subsurface structural fractures and/or mineralized zones. Depths evaluation analysis from the Euler Deconvolution (ED) technique using structural index of 1, ranged from 5 m to 15 m while depths varying from 4.9 m to 13.7 m were obtained from the Source parameter imaging technique.