Remote sensing techniques using Landsat ETM+ applied to the detection of iron ore deposits in Western Africa

Arabian Journal of Geosciences (Impact Factor: 1.22). 11/2013; DOI: 10.1007/s12517-012-0725-0


Remote sensing methods enable the rapid and inexpensive mapping of surface geological and mineralogical features. This capability proves highly useful when working on isolated or inaccessible areas. In this study, several enhancements of Landsat Enhanced Thematic Mapper plus (i.e. band ratios, false colour composites and principal component analysis) were used and evaluated to obtain the best possible visualisation of iron deposits hosted in the Devonian sedimentary rocks of northwestern Africa. In particular, two test sites were chosen: southern Algeria (Djebilet area), where the literature mineralogical and geological data on iron mine fields were already available, and the Western Sahara (the southern flank of Tindouf Basin), which was investigated during a field campaign and was where the occurrence of an analogous sedimentary succession led us to hypothesise the possible presence of exploitable iron deposits. This work demonstrates the usefulness of multispectral imagery in the detection of iron-rich areas and establishes a full remote sensing procedure, which can be profitably applied to a wider region of Western Sahara and can provide interesting perspectives on the possibility of detecting new exploitable iron ore deposits in arid environments.

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    • "Further geological information was inferred through correlation with the same sedimentary sequence cropping out in the south of Algeria (Djebilet), where three iron districts are present (Guerrak 1988). Then, a photo-lithological mapping of Western Sahara, based on enhancement of Landsat ETM+ imagery, was used to define the extent of the sedimentary unit, cropping out in Algeria and Western Sahara, which hosts the Algerian iron deposits near Djebilet (Ciampalini et al. 2012b). "
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