Contribution of remote sensing to mapping In-Abeggui gold deposit (Central Hoggar, South Algeria)

Abstract

The area concerned with the application of remote sensing is the In-Abeggui gold deposit in the Eastern part of Laouni terrane (Central Hoggar, South Algeria). This deposit includes a system of gold-bearing quartz veins marked by intense hydrothermal alteration. The gold veins are hosted in a big gabbro-diorite massif, cut by microgranite and aplite dike veins, all situated in a Neoproterozoic volcanogenic basin. The aim of this paper is to use LANDSAT 7ETM+ satellite images for mapping and characterizing gold-bearing veins, faults, and host rocks in the studied area and especially comparing the results with our traditional field work. All of the techniques used, such as colored compositions (CC), spectral band ratio, principal component analysis (PCA), and directional filtering, allowed a better lithological discrimination of the different formations. Moreover, they highlighted a hierarchical distribution of faults and emphasized their preferential directions. As regards lithology, the visualization with colored composition (RGB) of the three principal components (PC1, PC2, PC3) enabled us to clearly distinguish gabbros, diorites, volcanogenic rocks, and detrital rocks. Besides, we could distinguish between various faults, white aplitic dikes, and various gold-bearing quartz veins.