| Wadis 
Quatemary undifferentiated 
Gravel 
Syn-tectonic granitic rocks 
Post-tectonic granitic rocks 
Syn-tectonic gabbroic rocks 
Post-tectonic gabbroic rocks 
Granitic-gneissic rocks 
Ultramafic rocks 
Sedimentary rocks 
Metasedimentary rocks 
Graphitic gneiss 
Bl Acidic-intermediate gneiss 
Intermediate-basic gneiss 
Quartzite/Amphibolite 
Amphibolite 
Cenozoic acidic volcanic rocks 
Cenozoic basaltic volcanic rocks 
Acidic volcanic rocks 
intermediate-basic volcanic rocks 
Acidic metavolcanic rocks 
Interm.-basic metavolcanic rocks 
Basic metavolcanic rocks 
BB Acidic dikes 
Volcano-sedimentary rocks 
Metavolcano-sedimentary rocks 
(greenschist-facies) 
Bl Metavolcano-sedimentary rocks 
(amphibolite-facies) 
Fia. 7: GIS classification from Landsat TM ratios 3/1, 5/7and 3/5 combined with information from visual interpretation oi 
! ic depicted in fig. 1. The classification, discriminating between 27 lithologic units, is an improvement over the 
original map based on visual interpretation and over any digital classification relying on spectral properties alone.