Utilization of remote sensing technology in geological mapping : a case study in part of ‘Asir’, Southern Arabian shield

Abstract EN

The Landsat Thematic Mapper (TM) scanner records six bands of reflected visible and infrared spectrum and one thermal infrared band, the data from which are available in photographic and digital form.

A study area of 225 km2 in the southern Arabian Shield, was selected to demonstrate the utility of the Landsat TM sensor digital imagery for lithological mapping and structural analysis.

The selected area is complex due to polyphase deformation, which had resulted in interference fold patterns and faulting.

The major lithologies are: gra- nites, gneisses, metasediments, metavolcanics.

and gabbroic rocks.

Several image processing techniques were applied to the I'M data, following which visual in- terpretations and map constructions were performed employing the resulting images, these processing techniques included: band ratioing.

decorrelation stretching, and edge enhance- ment.

The results demonstrate that TM data can be used for lithological mapping and struc- tural analysis in well exposed arid regions, and to generate detailed geological maps over large areas by using quantitative remote sensing methods, where prior knowledge is available for part of the area.