Utilization of image processing of landsat-7 data in the exploration of radioactive anomalies of Gebel Homrat El Girigab, North Eastern Desert, Egypt

الملخص EN

Gebel Homrat El Girigab is a part of Esh EL Mellaha range, is located at the north Eastern Desert of Egypt.

It is composed mainly of Precambrian basement rocks.

Radiometric exploration indicated radioactive anomalies in Gebel Homrat El Girigab.

Image processing techniques of digital Landsat-7 ETM + data were used in the interpretation of Gebel Homrat El Girigab radioactivity.

These techniques were used for lithologic interpretation and structural lineament analysis of Esh El Melaha range with special emphasizing on G.

Homrat El Girigab.

Extraction algorithm was applied using GeoAnalyst PCI EASI / PACE package under the default parameters.

Statistical analysis of the automatically extracted lineaments showed that the visible spectral band-1 scored the highest lineament frequency 2320 compared to the other visible and near infrared (NIR) bands.

The interpreted structural lineament patterns for lithologic units of the investigated area showed that the major structural lineaments have predominant trend in the NW-SE direction (Gulf of Suez trend).

The main predominant trends of the automatically extracted minor lineaments are NE-SW and ENE-WSW directions.

The integration of the color raster aeroradiometric total count map with the interpreted lithologic and structural maps showed that the high radioactivity zones are restricted to the younger granitic rocks of Gebel Homrat El Girigab which is characterized by high lineament density and intersections.

The results showed that the radioactive anomalies in the investigated area are restricted to the younger granitic rocks and controlled by the NE–SW and NW–SE lineaments and their intersections.

Accordingly, these must be taken in consideration in the ground investigation of the study area.