Reconnaissance geochemical and geophysical exploration for gold at Iri gold field, north central Nigeria

Abstract

Field geological mapping and reconnaissance geochemical and geophysical exploration for gold was carried out at IRI Gold field north central Nigeria. Results of the geological mapping show the major lithology in the area is silicified sheared rocks and large quartz veins. Undifferentiated schist was intruded by quartzite at different locations and possibly during a major geological event which left shattering of the rocks all around two major ridges within the study area. Preliminary geochemical characterization revealed the rocks have weak geochemical anomalies of gold (Au), except in two locations where positive anomalies of gold (L3B=455ppb and L14=582ppb) were observed and identified as targets for further exploration. Interpretation of the aeromagnetic data gives the orientations of the structural features, and the major structural trend in the area is NE-SW. The lineaments extracted from the magnetic data range in length from 46.43m to about 1251.66m. Most of the lineaments extracted from the area are subsurface within the quartz-mica and migmatites while some of them have surface expressions, even though they are not clearly defined. Overall, the interpreted, geochemical signatures coincide with the geophysical signatures and were used to delineate the target prospective areas.