Major element, K/Ar, sedimentation and palynology data are reported on Tertiary volcanic and sedimentary rocks from the Yayu and Delbi-Moye Basins, SW Ethiopia. In the Yayu and Delbi-Moye Basins, pre-rift volcanic (basalts) and post-rift volcanic (basalts) are separated by coal and oil shale-bearing sedimentary rocks. The basalts are tholeiitic in composition. The ...