Morocco's total oil shale resources are estimated to contain 53.381 billion barrels (8.4869×10^9 m3) of shale oil.[1] According to the United States Department of Energy, the oil shale deposits in Morocco constitute about 3.5% of the world's known oil shale resources.[2] There are ten known oil shale deposits in Morocco.[3] Most of the local deposits were laid down during the Upper Cretaceous era and are marinites. The most important of these are located at Tarfaya (in the south-westernmost part of Morocco) and Timahdit (in the Middle Atlas Mountains).[4]