HyMap airborne imaging spectroscopy for mineral potential mapping of cupriferous mineralization in a semi-arid region based on pixel/sub-pixel hydrothermal alteration minerals mapping – A case study

Abstract

<p>Recently, hyperspectral datasets recognized a great interest in mineral exploration studies due to their high accuracy in detecting and mapping hydrothermal alteration minerals. Remote and mountainous regions are hardly accessible by geologists, while the spectral richness of imaging spectroscopy could provide detailed information about geology/mineralogy without having a direct contact with the ground surface. The Kerdous inlier in the Anti-Atlas belt of Morocco is recognized by several occurrences of Cu, Pb, Zn Au, Ag, and Mn mineral deposits. This study is carried out in Eastern Kerdous where the abandoned Idikel mine occurs in order to perform a high-resolution mineral potential map using Gamma-Fuzzy logic approach with twenty HyMap-derived layers. The HyMap-based thematic layers were generated using Directed Principal Component Analysis (DPCA), Relative Absorption Band Depth (RBD), and the Mixture Tuned Matched Filtering (MTMF) for pixel/sub-pixel mineral mapping. The hydrothermally altered regions within the study area reveal several Minerals/Mineral mixtures of hematite, illite, kaolinite, montmorillonite, muscovite, topaz, dolomite, and pyrophyllite. Then, the line density map extracted automatically from the HyMap data image was also integrated. The findings of the image processing were validated using field investigation, petrographic, and XRD analysis. This study demonstrates the great potential of the present research methodology and HyMap as a tool for mineral exploitation in similar areas in Morocco's western Anti-Atlas belt.</p>

Hydrothermal Alteration Features Enhancement and Mapping Using High-Resolution Hyperspectral Data

“…Additionally, Al-OH is mapped by dividing the sum of band 101 (2094 nm) and 111 (2268 nm) by band 108 (2217 nm). The enhancement of Mg-Fe-OH/CO 3 alteration minerals can be performed by dividing the sum of Band 111 (2268 nm) and 120 (2414 nm) by band 114 (2318 nm) [8,15]. This capability is grounded in the distinctive absorption features exhibited by these minerals [1].…”