The study area is located around Lake Hayk northeastern central part of Ethiopian. In this studyrnpetrographic, and geochemical (trace and major elements) data of mafic to felsic rock are presented,rnintegrated, and interpreted to characterize the geochemistry of cogenetic suite and petrogenetic processesrninvolved in the evolution of these flood basalts to differentiated rhyolite rock units. Fieldwork forrnsampling and mapping, petrographic investigations, and major and trace element geochemical analysisrnusing ICP-AES and ICP-MS procedures are all completed to meet this objective. The area constitutes ofrnbimodal composition of flood basaltic to rhyolitic rock with scarce intermediate composition. The rockrnunits that make up the research area are basalt, basaltic andesite, trachydacite, and rhyolite, based on totalrnalkalis versus silica (TAS) classification. The basaltic rock (La/Yb) N ratio = (5.34-10.97), basalticrnandesite to rhyolite (La/Yb) N ratio = (6.19-11.74), basalt is less to moderately fractionated thanrnmoderately fractionated basaltic andesite to rhyolite. The basalt, basaltic andesite to rhyolite samples havernratios of Ce/Pb >19.65-33.2 and 6.13-15.6 respectively and basalt sample has ratios of Nb/U = 39.55-rn45.81 and basaltic andesite to rhyolite have Nb/U= 21.59-33.68 and basalt and basaltic andesite tornrhyolite has ratios of Nb/Th=9.7-12.3, 5.08-8.63 respectively. Basalt have low Rb/Nb = 0.5-0.58, La/Nb =rn0.88-1.06 and high TiO2 = 2.08-3.04,basaltic andecite have higher Rb/Nb =2.7, La/Nb = 1.81 and lowrnTiO2 1.96 and rhyolite Rb/Nb = 0.97-1.69, La/Nb = 0.51-1.08 and lower TiO2 = 0.41- 0.71.MgO againstrnincompatible trace elements such as Th, La, and U has a negative correlation this testifies that there isrninsignificant continental crust involvement and Ce/Pb displays a positive correlation with MgO suggestrnthat there is minimal crustal contamination. The positive and negative anomalies of Ba and Krnrespectively, testify related to amphibole mantle source. The basaltic rock unit characterized by lowrnCaO/Al2O3 ratios (0.71â€“0.99) and relatively no fractionation and flat HREE patterns with (TbN/YbN =rn1.75-2.33) chondritic values this suggest a mantle source mostly containing spinel rather than garnet andrnthe gentle slope in HREE show the source for mafic rock is garnet free. Rhyolite is characterized by arnsteep negative correlation in bivariate major oxides such as MgO,Fe2O3,TiO, and CaO against SiO2 andrnpositive anomaly of Ta with slight Nb trough which implicate that Rhyolites formed by fractionalrncrystallization rather than significant crustal contribution, partial melting and assimilation. Detail isotoperngeochemistry and mineral chemistry studies are much recommended around Lake Hayk.