The oldest rock in southern Sarawak is schist, which was formed during the Carboniferous and Lower Permian times, while the youngest igneous rock in this region is andesite, found at Sematan.
The oldest rock in southern Sarawak is schist. This schist is found at Sematan. Schist was formed during the Carboniferous and Lower Permian times. The youngest igneous rock in this region is andesite.