Results and Discussion
Generally, surface cover is a direct consequence of subsurface geology. The
reflectance spectra of weathered iron minerals are weak in the blue (0.45-0.52 um)
region TM band 1 and strong in the red(0.63-o.69um) region-TM band 3, hence ratio
3/1 has high values for iron stained areas and emphasized natural hydrated oxide,
which shows as bright patches. The clay minerals, which are enriched in the highly
weathered pegmatites, band 5 centered at 1.51 um(band 5) was ratioed to band 7. The
Al-OH and Mg-OH rotational effects associated with clay and other hydroxylated
minerals result in absorption within Landsat TM band 7 centered at 2.2um. Clay riche
zones (weathered feldspars in Pegmatites) with absorption features in band 7 and
higher reflectance in band 5 show up as bright patches in the ratio image especially
around the mining areas of Banke complex and Rafin Bareda (Kankara and Magaji,
2008).
From the result of the specific enhancement procedures the suitability of the areas
depend on