Banded gneiss, schist and quartzite formed from the metamorphism of greywacke, shale and interbedded sandstones. Some amphibolite layers record the metamorphosed remains of a tholeiitic magma series. The early folding and metamorphism in the Ibadan area was followed by the emplacement of aplite schist and microgranodiorite dikes during the Liberian orogeny 2.75 billion years ago.