Integration of ASTER and geophysical data for delineating potential mineralization zones in Dungash-Atud area, Central Eastern Desert, Egypt

Abstract

Dungash-Atud area, located in the southeastern Egyptian Desert, is intensively distinguished by gold mineralization and associated mineral deposits. This area was studied using the integrated analysis and interpretation of ASTER, aeromagnetic, and gamma-ray spectrometric data. For ASTER, different approaches of image processing, such as false color composite (FCC), ASTER-TIR indices, principal component analysis (PCA), and spectral mapping, have been used to determine the desired information on the geology, lithology reclassification, and the existing minerals, particularly older and younger granites, basic, and ultrabasic rocks. Also, the alteration imagery maps of different minerals, sericite, chlorite, illite, kaolinite, calcite, epidote, and quartz, are obtained and classified, in addition to Mafic and Quartz Index. The processed and interpreted aeromagnetic data helped effectively for the detection of the deep subsurface and near-surface structural elements affecting the area and inspection favorable sites of mineralization that give strong magnetization of which chromite bodies associated with serpentinite rocks. In addition, the aerospectrometric data, equivalent uranium eU, equivalent thorium eTh, potassium K%, and total count (TC), were analyzed and hence the ratio maps (eTh/K, eU/K, and eU/eTh) and ternary radioelement composite images were produced to infer the enriched sites of U and Th mineralization. The integration of these results was guided and tied with previous geological information, especially ancient and present gold mines and associated mineral deposits. Such results gave clear clue about the existing number of basic to ultrabasic parallel wide dikes injected within fault zones trending mainly parallel to the Red Sea rift tectonics (NW and NNW directions) and other faults/dikes, trending in the NE direction. The long-extended NW trending wide dykes are cutting across the whole investigated area reflecting its deeper extension. Other faults show lateral displacements representing major shear zones, trending mainly in the NE direction. The produced potentiality map using GIS technique showed that most of the ancient gold mines and/or associated mineral deposits are related and controlled greatly with the detected structural elements, dykes, and rock affinity. Hence, it is easy to follow other sites that could have a high potential for mineral deposits including a gold through further field investigation in coordination with the detailed ground geophysical survey.