Korme, Tesfaye (PhD)Hagos, Miruts2022-01-262023-11-182022-01-262023-11-182003-11http://etd.aau.edu.et/handle/12345678/29695Southern Afar Rift margin is a 2S-30km wide zone separating the Somalian plateau from the Afar rift floor. It shows a complex fault pattern, characterized by the interplay of: (i) an E - W trending marginal fault system, (ii) a northwesterly major lineaments (faults) and (iii) a NE trending Nazareth fault system. The E - W oriented faults playa dominant role for the present morphology of the southern Afar rift margin and for the existence of highly tilted Mesozoic rocks. Rifting induced late Cenozoic volcanism in the southern Afar rift margin three main types. The oldest felsic rocks, aligned parallel with the boundary faults, are formed contemporaneously with these faults. The olivine free basalts and the Rhyolites are found with in the marginal half grabens. And the youngest volcanic rocks of the area are the Afar stratoid series, erupted during further episode of rifting and tilting. The marginal fault plane and bedding plane relationship of the area confirmed that the bed orientation is greatly controlled by the orientation of the faults. The strike of the beds and faults is nearly similar; however, their dip amount is inversely related and their dip directions lay opposite to each other. Systematic field observations and accurate measurements of the orientation of structural elements have enabled to identify the nature of fau lts at depth: the presence of roll-over anticline structures together with the subsidiary normal faults led the author to conclude that the nature of faults at depth is listric normal. The general fault pattern of the southernAfar rift margin, as well as mesoscopic fault analyses indicate the occurrence of a roughly NNE-SSW extension with small component of dextral shear motion along the Rift margin.enIn Partial FulfilmentThesis