A fuzzy logic approach for gold mineralization zones mapping in western parts of Zamfara State, North-Western Nigeria based on harmonized Landsat and sentinel-2 L30 data.

Abstract

This study identified lithological and hydrothermal alterations zones with potential that coincide with gold mineralization in the western parts of Zamfara state, North Western Nigeria, based on harmonized Landsat and Sentinel-2 L30 data. The research enhances prior studies by utilizing the advanced HLS L30 dataset in conjunction with the fuzzy- model overlay approach. The techniques that were used are false colour composites, band ratios, principal component analysis, both standard and crosta methods, fuzzy-logic overlay and automatic lineament extraction methods. The false colour composites and standard principal component analysis methods identified rocks units such as schist, gneiss, quartzite and limestone within the study area. The band ratio (Sabin’s and Kaufmann ratios) identified four main alteration zones and crosta PCA methods showed ferric-oxides, ferrous silicate, argillic and phyllic alterations related to gold deposits. The fuzzy logic overlay map highlighted potential mineralization zones, providing a basis for further mineral deposit evaluation.  Applied PC4 revealed high potential zones ranged 0.8- 1.0 of ferric oxides, ferrous silicate, argillic and phyllic alteration minerals respectively. The results from the thematic layers identified three (3) favourable zones, which account for 63.3% of the study area. These zones align well with existing mining sites and areas with high potential for gold mineralization, as supported by the literatures and field research.  The highly prospecting zones are Gayssawa, Gwalli, Leshi, Tadurga Surimi, Gidan Hardo and Bawa areas receptively. Furthermore, lineaments and lineament density analysis showed the presence of three main structural direction (N–S, NNE-SSW, and NNE-SSE to SSW-NNW), that is high, intermediate and low respectively, when combined with identified lithological formations, permit the possible deposition of mineral deposits. This research recommends the harmonization of Landsat and Sentinel-2 data for efficient identification of gold deposits in the western part of Zamfara state, Nigeria.