Valera, R. (Prof.)Getahun, Aberra2022-03-162023-11-182022-03-162023-11-181985-10http://etd.aau.edu.et/handle/12345678/30623The r ocks of the stuJied area form nart of the ~ ol lera Birbir group of the upper complex and cons ist of a s eries of metasedimentary and plutonic proterozoic rocks. The l1'inieralo£"ical assemblage indicate th a t the metamorphism is of the rreenshist facies. The variation diagram constructed for the various plutonic rocks strongly suppest comagmatic origin by crystal f ractionation. Ma jor and trace element analyses of reDresentative samples of the Chago iron for mation, t he plutonic an~ YOllnper effusive rocks are present ed. TIle Chago iron formation can be classified as nrecambrian banded iron formation and is in l1'any r espects similar to the oxide facies iron formation of Lake Superior t ype. The Cha go iron formation consists only of iron oxides and mi nor aIT'ount of si l ica with total absence of iron silicate, sulfide and carbon ate minerals. Trace element peochemistry suppests that the iron f ormation was chemically precipitated as oxidate sediments in wh i ch the principal iron mineral, ma gne tite, was formed at low temperature in a shal low near shore environment .enBanded ,Geology ,GeochemistryThesis