The Nazret=DGra area forms a segment of the northern part of the Main Ethiopian Rift. The region is character-' ized by a complicated morphology which is a result of several episodes of volcanism and tectonism. The volcanic rock units outcropping in the area are principally bimodal in nature and it is possible to sub~ divide them into 6 groups according to their spatial distribution. The groups include; the stratoid Eastern Margin and Dera-Nazrot group mainly formed by a series of flood basalts inter layered with ignimbrites and Rhyolites; Keleta group, representing the oldest rift floor product and constituted by Ash flows and Ignimbrities; Boku and Gedemsa group,'which are rosults of central type volcanic activity evidenced by preserved caldera of Gedemsa and destructed caldera of Boku, giving rise to Pantellerites, Rhyolites and pumice fall deposits and Melkasa group which is constituted by basaltic spatter concs and associated 'AA' type lavn f1.ow. The nge of the rocks vary from 1.7 my to 0.06 my. The large volume of acidic product as compared to the basaltic one and the lack of transitional rock units suggest that there is a pnrtial melting of the lower crust probably induced by intrusion of large bodies of basaltic magma From Tectonic POitit of view, tho area is chAracterized by right stepping, "8n echelon" halt grabens, grabens and faults which affect evan the youngest rock outcropping in the region, The geometry of these structures i,D. an overstepping towards the right suggest a left lateral motion along this part of the rifto The theory is substantiated by meso-scale structural data which has been collected from, small faults with slicklines, extensional fractures and joints which show that the area is undergoing an eastnortheast, west-southwest extensiono Thus strike-slip system and oblique extension is the major mode of deformation for this part of the Rift System and possibly may extend across the whole length of the Main Ethiopian Rift