Integrated geophysical Investigation for gold mineralization potential over southern parts of Kebbi state and its Environs, northwestern Nigeria

Abstract

The potential zones of gold mineralization were identified in this study using aeromagnetic and aero-radiometric methods. The Nigerian Geological Survey Agency (NGSA) provided half-degree airborne magnetic and radiometric datasets covering the southern part of Kebbi State. Magnetic data were subjected to first vertical derivative (1VD), total gradient amplitude (TGA), total horizontal derivative (THD), source edge detection (SED), center for exploration targeting (CET), Euler deconvolution (ED) and source parameter imaging (SPI) to identify favourable structures to gold mineralization. Aero-radiometric data delineation of the region of hydrothermal alteration zones through the K/eTh ratio, K_deviation, F_parameters, and Ternary image analyses were successful. The results of the magnetic data techniques revealed the regions of major structures/or lineaments with gold mineralization attributes, trending in the NE to SW directions and the SE to NE parts of the study area. The depth to the structures of the magnetic source hosting gold mineralization was less than 5 m using algorithm ED and SPI techniques. Normalized radiometric data showed the area of anomalously high and moderate hydrothermal altered zones. The region's designation as a gold field is supported by major fault lines observed on the 1VD, a sequence of bristle fractures from the CET analysis, and high values of K_deviation and F_parameter, all of which are were visible on the Ternary images. The integrated results revealed zones of major structures and hydrothermal regions of gold fields at Agwara, Western Magama, Rijau, Fakai, Bukkuyum, and Borgu in the SE of the study area.