The reserves of Essexite and Oil shale are geographically distributed all over the world. Essexite and Oil shale reserves play an important role in a country’s economic growth. Rocks are deposited according to the topography of the area. Some oldest rocks can be found in the Canadian Shield, Australia, Africa and in a few other old regions around the world. The ages of these felsic rocks are around 2.5 and 3.8 billion years. Learn about the countries with Essexite and Oil shale reserves here.