Studies of modern carbonate settings have documented varied origins for mud-size sediment, including disintegration of benthic and planktic organisms, precipitation from the water column, and mechanical breakdown of larger particles. Carbonate muds accumulate in protected “low-energy”settings on the platform top and are also exported to adjacent deeper-water settings. As a consequence of the “energy”of some of these settings, organic-rich, oil-prone carbonate source rocks may develop.