Geo-electrical Prospecting for Ore Minerals in Kundu, Western Part of Zungeru Sheet163NW, Nigeria

Abstract

Analysis of Global Digital Elevation Model (GDEM) and surface geological mapping were combined with vertical electrical resistivity sounding (VES), spontaneous potential (SP) and induced polarisation (IP) sounding to identify locations with possible subsurface ore mineral deposits within Kundu. The GDEM is a radar topographic imagery with 50m resolution .The GDEM's hillshade view revealed NNE-SSW lineaments that are laterally displaced by dextral faults. The geological mapping revealed that the lineaments are NNE-SSW striking outcrops of gneisses, schists and amphibolites. The gneisses and schists contain lenses of quarzites, and dip 30 to 70 SSE. Some of the rocks host fractures with veins of quartz mineralisation. The soundings were conducted at fifty one geo-electrical stations. Subsurface pegmatite bodies and quartz veins were inferred to constitute deduced subsurface fractures characterised by SP value between +20 and +40 mv. The subsurface pegmatite bodies and quartz veins at stations L1, L6, L23, L26 and L51 are associated with IP values higher than 10 ms, and consequently inferred to possibly host disseminated ore minerals. Massive ore minerals were inferred to be hosted within deduced subsurface fractures characterised by lower than 150 ?m resistivity value and SP values in the neighbourhood of -100 mv. Such fractures were identified at sounding stations L9, L36, L45 and L50. The disseminated and massive ore minerals appear located in the central portion of Kundu, and aligned approximately N-S. The mineralising solutions were probably structurally controlled by N-S trending fractures. Coring combined with electrical logging can now be conducted in the town within the region defined by latitude N9.822, N9.834 and longitude E6.145, E6.149. Geochemical analysis of the cores is recommended to ascertain the types of ore minerals present. Further work such as assaying and reserves estimation is suggested after coring to warrant taking investment decision.