Geological and structural interpretation of airborne surveys and its significance for mineralization, South Eastern Desert, Egypt

Abstract

Interpretation of aeromagnetic and radiometric geophysical data is carried out in an area of the Precambrian basement rocks of the south Eastern Desert of Egypt. The area is delimited by lat. 24°00′ and 25°00′N and long. 34°00′ and 35°00′E.

Aeromagnetic anomalies in the area reflect important features on basement tectonics, on deep-seated structures and on detailed geological mapping. Major faults and shear zones, which play an important role in the emplacement of mineralized bodies, have been interpreted and two tectonic blocks are suggested. The statistical analysis of the basement fractures and aeromagnetic lineaments shows major NNW, NW and ENE trends with intersections indicating locations of magmatic intrusions and alkaline ring complexes. The depth computations indicate shallow to near surface magnetic sources as well as deeper ones. The constructed residual, second- derivative, upward-downward continuations and regional maps respectively emphasize these features. The surface rocks of basic -ultrabasic affinity are reflected on the magnetic map. Other rock units give low magnetic effects that indicate variations in lithological composition and/or the degree of metamorphism.

The total count-radiometric map shows a close relationship between the alkaline rocks (e.g. ring complexes) and younger granites as well as strong radioactive indications of uranium and/or thorium mineralization (e.g. G. Abu Khurq and G. Kahfa). The linear radiometric anomalies indicate locations of fault lines which are mineralized with radioactive minerals, such as at G. Hafafit area. These faults are also interpreted from the magnetic map. Additional locations are recommended for further ground geophysical and geological explorations.