APPLICATION OF ASTER AND ETM IMAGES DATA IN DETECTION OF GOLD-BEARING ALTERATION ZONES IN SOUTH EASTERN DESERT OF EGYPT

This study is focused on application of various remotely sensed data to reveal the spectral characterizations of some basement rocks and delineating the gold bearing alteration zones in three localities in the South Eastern Desert of Egypt namely; Wadi Beida, Wadi Defiet and Gabal Hoteib areas. In general these areas are occupied mainly by Precambrian basement rocks. The image processing of the ETM+ and ASTER data have been carried out using ERDAS Imagine 2013 and ENVI 5.0 Software. Resulted images have been used for detailed geological mapping and discrimination of the mineralized alteration zones .On the other hand, to discriminate the basement rocks forming the two areas of Wadi Beida and Wadi Defiet and detection of the gold-bearing quartz veins and the alteration zones, the data of field study and the processed data of ETM+ image have been applied. The ETM band ratioing has been applied to discriminate the goldbearing alteration zones. The present study revealed that, the ETM band ratio image (5/1, 5/7, 5/4*3/4) show best discrimination of the gold-bearing alteration zones within the host rocks at Wadi Beida, while these zones are well discriminated using the ETM band ratio image (5/7, 5/1, 4) at Wadi Defiet area. On the other hand the processed data of ASTER image is very effective in discrimination the rock units and detection of gold-bearing alteration zones at Hoteib- Al Fawi area. This study indicates that, the gold bearing zones in the studied three localities are promising; more detailed exploration for gold mineralizations is needed to evaluate their potentiality.