Combine Remote Sensing and Geochemical Techniques for Mineral Exploration in the Soil of Igoba and Ilado Areas, Southwestern Nigeria

Abstract

Mineral exploration within Nigeria’s Precambrian Basement Complex has been hindered by poor rock exposure, deep weathering, and complex structural patterns that obscure potential mineralized zones. This study integrates remote sensing, field mapping, and soil geochemistry to delineate geochemical anomalies and assess mineralization potential within the southwestern Basement Complex. Sentinel-2A imagery (Scene ID: S2A_MSILC_2023216T095101_N0509_R079_T31NG1_2023216T33019) was processed using ArcMap 10.5, Envi 5.4, Geomatica 2018, and Rockwork 17 for lithological and structural interpretation. Systematic soil sampling at 50-m intervals targeted the B-horizon (0.05–0.3 m depth), yielding fifteen composite samples analyzed at ACME Laboratories, Vancouver, using Inductively Coupled Plasma–Mass Spectrometry (ICP–MS) after Lithium Metaborate fusion. The analytical results revealed significant elemental enrichment across the study area: Zinc (Zn) recorded the highest concentration (136.563 ppm), followed by Thorium (Th) (17.0838 ppm) and Lead (Pb) (63.104 ppm). Arsenic (As) attained 3.116 ppm and spatially coincided with Zn anomalies around Irese–Olufoarm A.K., suggesting hydrothermal sulfide mineralization. Correlation analysis indicated strong positive relationships among Zn–Cu (r = 0.841**), Zn–Pb (r = 0.803**), Cu–Pb (r = 0.671**), and Co–Ni (r = 0.896**), implying common geochemical sources and hydrothermal co-precipitation of elements. Factor analysis defined three geochemical associations: (1) Base-metal factor (Zn, Pb, Cu, As), (2) Ferromagnesian factor (Ni, Co, Cr), and (3) Radioactive-element factor (Th, Fe). Collectively, the findings delineate the north-central Irese–Olufoarm A.K. zone as highly prospective for Zn–Pb–As sulfide mineralization, with elevated Th values reflecting felsic-related radioactive enrichment.