Marini, Alberto (Professor)Korme, Tesfaye2018-07-112023-11-082018-07-112023-11-081992-09http://etd.aau.edu.et/handle/123456789/8102studies of interactively enhanced Landsat thematic mapper (TM) imagery integrated with field survey and aerialphoto interpretations were carried out to map the lithology and structures of the study area located in the axial zone of the Main Ethiopian Rift. The Ethiopian Rift has been studied for decades using a variety of geological and geophysical techniques, but synoptic mapping of the lithology and structures and analysis of regional structural relationships have not been previously studied applying high resolution satellite digital data. By combining Landsat TM data with results from conventional method of geological mapping four major serieses of volcanic rocks have been identified, namely: 1. A lower series of pyroclastic deposits dominated by greyish green ignimbrite (Wedecha series), 2. A basalt series of transitional to subalkaline basalts character (Anole Series), 3. pyroclastic deposits of the Rift floor dominated by pumice and ash falls (Bora Series) and 4. Recent lava flows extruded through Wonji Fault Belt openings (Jano Series). In addition, four sets of structures were mapped: 1. Main marginal NE-SW striking normal faults, 2. E-W to NW-SE striking strike slip faults that have dextrally displaced the marginal faults, 3. NNW-SSE striking cross-rift lineaments and 4. the youngest and active NNE-SSW to N-S striking faults (Wonji Fault Belt). Using different techniques of enhancement most lithologic contacts and lineaments that had not been indicated in any existing geological and structural maps for the region were carefully mapped with better accuracy, minimum expense and shorter sorter field season. It has been observed that tectonism preceeds volcanism in time and the type of volcanic rocks assemblage and composition reflects the degree of rifting and intensity of tectonism that had initiated the volcanism.enBiologyThesis