This text examines the environmental setting and resulting phosphorites that formed during the Miocene, one of the major and most recent phosphogenic periods throughout the geological record. Sedimentary phosphate deposits (phosphorites) are of major commercial significance, being one of the world's most important non-renewable resources, and essential in the manufacture of phosphate fertilizers and phosphate based chemicals. An oceanographic perspective is provided by investigations of modern oceanic environments where phosphorites are presently forming. Together, the geologic and marine approaches provide a complete outlook on this important mineral resource. This is the third of four planned reference volumes that together will cover the achievements of the International Geological Correlation Programme Project 156 (Phosphates) during the ten years of the project's existence. As with the previous volumes, this will form an essential work of reference for geologists and mining engineers interested in the search for, and exploitation of, phosphate rock deposits.