Petrogenesis of Butajira-Kibet Quaternary Basaltic Rocks; Central Main Ethiopian Rift

Major and trace element data are presented for Quaternary basalts from Butajira-Kibet area, close to the western escarpment of Central Main Ethiopian Rift investigate petrogenetic processes involved nature mantle source compositions. The indicate that mildly alkaline characterized by moderate high contents MgO (6.85-9.00 wt. %) TiO2 (2.40-2.92 %). In primitive mantle-normalized multi-element diagram, they exhibit troughs at Th, U, Rb K peaks Ba, Nb, Ta, La, Pb Sr with positive Eu/Eu*(1.01-1.17). Incompatible ratios e.g., Ba/Nb (8.92-16.25), Rb/Nb (0.42-0.70), K/Nb (233.00-340.00) Nb/U (47.97-61.05) suggest unaffected crustal contamination. acquired do not evidence fractionation plagioclase clinopyroxene. On other hand, relationships between major elements their (e.g., Na2O Ca2O/Al2O3) Zr/Y (La/Sm)N) partial melting a clinopyroxene - rich medium pressure. Chondrite normalized REE diagram is relatively flat HREE (TbN/YbN=1.73-2.13) significantly enriched (higher than 10-times chondritic values) patterns. LREE/MREE versus MREE/HREE modelling non-modal batch indicates formed 1.5-3% spinel peridotite minor contribution garnet-bearing peridotite. Primitive ratios, such as Nb/Zr, Nb/U, Ba/La, Rb/Zr Ba/Nb, studied affected carbonatite and/or hydrous phase metasomatism. Rather, closely similar OIB (mainly EM-I) SCLM. They most likely result significant interaction melts plume