Gold-related Alterations Mapping at the Um Balad Area, Egyptian Eastern Desert, Using Remote Sensing, Geophysical, and GIS Data Analysis

Paper ID : 1116-ICRSSSA (R2)

Authors

Mahmoud Abd El-Rahman Hegab *1, Salah Eldin Mousa2, Salem Mohamed Salem1, Karam Samir Farag2, Marwa Mostafa1 1NARSS 2Ain Shams University

Abstract

The Um Balad area is a part of the Arabian Nubian Shield (ANS), which hosts various gold and base metal deposits. Gold can be prospected in the alterations and sheared zones in the widely exposed metagabbro-diorite rocks in the Um Balad area. In this regard, the integration of ASTER multispectral data processing, gamma-ray spectrometry data analysis, GIS modeling, and fieldwork gave us a good indication of which areas are most likely to contain gold-related alteration zones in the study region. Three remote sensing techniques were applied, including Spectral Angle Mapper (SAM), Spectral Information Divergence (SID), and Mixture Tuned Matched Filtering (MTMF). Careful interpretation of the gamma-ray spectrometry data is reliable for mapping alterations related to hydrothermal activity. The potassium distribution (%) of the study area was analyzed, where the radioelement ratio maps [eTh/K and eU/K] were obtained. The F-parameter and the Th-normalization techniques (Ud %, and Kd %) respectively were applied for identifying potential mineralization zones. The GIS (weight overlay analysis) tool was used to combine the results of the three methodologies (remote sensing approaches, gamma-ray spectrometry data interpretation, and automatic lineament extraction) by combining ten layers (ASTER-SAM, ASTER-SID, ASTER-MTMF, lineament density, [K%], [eTh/K], [eU/K], [K*(eU/eTh)], [Kd], [Ud]). A final gold-related alteration zone map was generated. For validation, spectral signatures of the acquired rock samples, as well as scanning electron microscopy (SEM) were used for the result verification of such study. Finally, going forward, the adopted methodologies are considered as a chief for gold-related alteration mapping comparable environments.

Keywords

Um Balad, Gold, ASTER, Weighted Overlay.

Status: Accepted (Oral Presentation)