Marinite is a gray to dark-gray or black oil shale of marine origin in which the chief organic components are lamalginite and bituminite derived from marine phytoplankton, with varied admixtures of bitumen, telalginite and vitrinite. Marinite deposits are the most abundant oil-shale deposits. They are generally widespread but at the same time they are relatively thin and often of restricted economic importance. Typical environments for marinite deposits are found in epeiric seas (e.g. on broad shallow marine shelves or below inland seas where wave action is restricted and currents are minimal).