Geochemistry and Gold Mineralisation Potential of Ungwan Rimi and Environs, Part of Wamba 210 Sw/Kurra Sheet 189 Sw, North-Central, Nigeria

Abstract

The Ungwan Rimi area is located at the southern fringe of North-Central Nigeria 
and lies between (Lat. 8°34'19"E, 8°38'29"N and long. 8° 58'00"E, 9°00'45"N) near 
Wamba town. The area is underlain by Precambrian Basement Complex rocks. A 
A total of 20 samples were collected. Eight (8) are rocks samples, while twelve (12) 
stream sediment samples. The samples were carried to the laboratory for XRF 
analysis. The plutonic bodies observed from the geochemical classification plots 
depict granite and granodiorite to diorite. The major elements variation diagrams 
show that the rocks are essentially peraluminous, subalkaline, and calc alkaline to 
tholeiitic series rocks. The granitic rocks as intrusions into pre-existing migmatite 
gneisses are magnetic, while the migmatite gneisses are generally ferroans in 
composition. The rocks are S-type, which strongly implies being derived from 
sedimentary protoliths. The wide variation coexistence between the lithophiles 
elements clearly suggest that the rocks were possibly formed from fractional 
crystallization of melts derived from partial melting under the subduction-related 
settings. The geochemical distribution patterns revealed the relative distribution of 
pathfinder elements (Sn,Co,Sc,Ni,Cd,V,Ta,Nb,W,Hf, Ba,Th,U,Pt,Sb) of gold in the 
area. Ungwan Rimi and environs were geochemically assessed using factor analysis 
and correlation coefficient so as to establish the possible gold occurrence. The factor 
analyses (Factor 1:Cl,S,Sc,Co,Ni,Y,Cd,Sn, Au; Factor 2: V,Ta,W,Sb,Nb;Factor 
3: Ba, Hf, Th, and U) and co-efficient of correlation (Au vs Sn, Nbvs.Ta, Nbvs.Ta, W vs Ta, 
Sbvs W) supported the possible association between the pathfinder elements of gold 
in the area. The enrichment map derived from the metal ratio values for both the 
rocks and stream sediments depict areas of better promise in terms of gold 
potential in the area.