APPLICATION OF REMOTE SENSING AND AIRBORNE SPECTROMETRIC DATA ANALYSIS TO DELINEATE THE ALTERATION ZONES AT GABAL SUWAYQAT AREA CENTRAL EASTERN DESERT, EGYPT

The present study aims to study the potentiality of promised radioactive zones in the granitic rocks at
Gable Suwayqat area. The Processed Landsat ETM+ data false color composite image (FCC) band 7, 4, 2
in RGB, band ratios (5/7, 4/3, 3/1), (5/7, 5/1, 4), (3/1, 5/4,7/5) in red green blue and 5/7 in gray color.
Principal component analysis (Pc2, Pc3, Pc5) in RGB were prepared for discriminating rock unites.
Verified by the fieldwork and airborne gamma- ray spectrometric surveyed data enabled to differentiate
the acidic and mafic rocks, and identified the alteration zones in the granitic rocks, which were effectively
distinguished into high felsic and low ferromagnesian mineral contents, relative to the other granite areas.
The gamma-ray spectrometric interpretations reveal that most of radiometric anomalies recorded at north
eastern and south western sides of study area. The structural framework and consequent surface features
controled and managed the distribution and localization of the radioactive elements and the environmental
dose rates in the area. The high fractures density act as good channels and passages for the mineral bearing
hydrothermal ascending fluids and the percolating meteoric water that leached uranium mineralization and
redeposited it in the adjacent fractured sites. Such processes in the granitic masses may be responsible for
the presence of uranium and thorium mineralizations in these granites. The calculated dose rates range
between 0.1 and 1.1m Sv/year, indicating that the study area remains safe and under the maximum
permissible safe radiation dose rate without harm to the individual, with continuous external irradiation of the
whole body. The results show that the target area has some eU, eTh, and K% anomalies related to the
biotite granites and are structurally controlled by the dominated faults.