GENESIS OF MIOCENE POLYMETAL MINERALISATIONS, WESTERN RED SEA COASTAL ZONE, EGYPT. MAHMOUD M. HASSAAN Faculty of sciences, F 1-Azhar University, Cairo, Egypt. Polymetals mineralisations of Ba-Fe-Mn and U-Pb-Zn occur along the Western Red Sea coastal zone. The study of field relations, mineral composition, geochemical associations and modes of occurrence favoured that these mineralizations represent a phase of Middle to late Miocene age. Their Hydrothermal origin due to the volcamic activity accompanied the Red Sea rifting is evidenced by the following: 1. The mineralisations occur in several stratigraphic beds of different ages (late Proterozoric, Late Cretaceous and Miocene.), 2, Their localization is lithostructurally controlled, where they occur in fault zones of NW trend, 3- These mineralisations show the same oxide-sulphide minerals and simitar geochemical associations,4-Local(vertical and lateral), and regional zoning control their distribution and 5-These mineralisations in association with the Red Sea mineralized hot brines complete the general deacrese in age of mineralisation phases in northern Africa.