The oldest rocks in Senegal are Archean or Proterozoic Birimian, commonly found throughout much of West Africa. Birimian rock units include the metabasic, meta-andesite, breccia and greywacke of the Mako Series, Diale Series meta-basites, red jasper, conglomerate, schist and marble, as well as the schist, greywacke and conglomerates of the Dalema Series. In the Kedougou inlier, these volcanic and sedimentary rocks were intruded by granite plutons in the Paleoproterozoic, during the Eburnean orogeny between 2 billion and 1.8 billion years ago.