Erosion of Tortonian phosphatic intervals in upwelling zones. The role of internal waves
During the Miocene, the upwelling is assumed to be important in the formation of many Mediterranean phosphate deposits in carbonate platform successions. There are different types of upwelling mechanisms such as equatorial upwellings, ice-edge upwellings and coastal upwellings. The carbonate platforms are mainly affected by wind-driven coastal upwelling systems. During upwelling season, the seawater in coastal areas is strongly density stratified and the permanent pycnocline rises inshore forming an inclined frontal layer.