Imaging of hydrothermal altered zones in Wadi Al-Bana, in southern Yemen, using remote sensing techniques and very low frequency–electromagnetic data

• Published in: Arabian journal of geosciences 2019-09, Vol.12 (18), p.1-16, Article 554
• Main Authors: Farag, Karam S. I., Howari, Fares M., Abdelmalik, Karim W.
• Format: Article
• Language: English
• Subjects: Anomalies; ArabGU2016; Current Advances in Geology of North Africa; Data; Data acquisition; Earth and Environmental Science; Earth science; Earth Sciences; Economics; Geographical information systems; Geophysics; Imagery; Imaging techniques; Landsat; Landsat satellites; Low frequency; Mapping; Mineralization; Minerals; Principal components analysis; Remote sensing; Satellite imagery; Very Low Frequencies
• ISSN: 1866-7511; 1866-7538
• DOI: 10.1007/s12517-019-4702-8

Economic mineralization and hydrothermally altered zones are areas of great economic interests. This study focusses on hydrothermal altered zones of high mineralization potentials in Wadi Al-Bana, in southern Yemen. An azimuthal very low frequency–electromagnetic (AVLF-EM) data acquisition was conducted in search for mineralization in the study area. The study integrated observations from geophysical field data with others extracted from object-oriented principal component analysis (PCA) to better map and understand mineralization in the investigated area. This technique was applied to two data sets, ASTER and Landsat 8 Operational Land Imager (OLI) imagery. The results of PCA revealed high accuracy in detecting alteration minerals and for mapping zones of high concentration of these minerals. The PCA-based distribution of selected alteration zones correlated spatially with high conductivity anomalies in the subsurface that were detected by VLF measurements. Finally, a GIS model was built and successfully utilized to categorize the resulted altered zones, into three levels. Graphical abstract