Gold endowment of brittle-ductile shear zones is related to interplay of competency contrast, attenuation of the stratigraphy, lithological contacts and zones of dilation. Greenschist facies shear zones with variable orientation of lithological contacts and structures, close to regional seals should be assigned highest priorities. In this study, we present a new adapted Automated Lineament Extraction (ALE) method to trace fault and joint sets at the mine- and regional-scales. ASTER GDEM data are used for automated lineament mapping of selected gold mine areas in the South Eastern Desert. The new technique applies the LINE module of PCI Geomatica V9.1 based on automatic detection algorihms (canny algorithms). The resultant lineaments were compared with published structural maps of the area, in terms of total length, number and direction. The comparison shows great similarity between both automated and published geological maps. The number and total length of the lineaments extracted by the new automated method were found to be more than those appear on the published geological maps. Worth noted, directional analysis of the automatically extracted lineaments verifies the major structural trends in each of the mapped areas. The multi-furcated geometry of the northern Hamisana Zone, along with occurrence of the large ophiolitic blocks would provide a typical setting for structure-controlled lode gold. The new ALE method was found successful for quick definition of dense lineament intersection zones as a prerequisite for field check and drilling programs. Integrating the new adapted ALE method with geochemical investigations would allow a low-cost, fast and efficient exploration strategy for new targets in such and similar vast terranes. |
