ABSTRACT
Ethiopia is a key area for an understanding of crust formation and orogenic processes during the so called Pan-African event. The juvenile island arc complexes of the Arabian-Nubian Shield (ANS) in Egypt, Sudan and Saudi Arabia continue into Ethiopia and are found in tectonic contact with the predominantly gneissic terrane of the Mozambique belt (MB) that extends farther S into East Africa. This chapter focuses on a geochemical reconnaissance survey of magmatic rocks from certain lithotectonic units in eastern and southern Ethiopia previously assigned to the Lower, Middle and Upper Complexes respectively. It analyzes eleven samples, five from eastern and six from southern Ethiopia for major and trace elements by X-ray fluorescence (XRF). Granulite-facies rocks only occur in southern Ethiopia where they are known as Konso Gneiss. These rocks were once considered to be the oldest rocks in Ethiopia and are regarded as the lowest unit of the Lower Complex.
