Mineral Occurrences Related to Stratigraphy and Tectonics in Tertiary Sediments near Umm Lajj, Eastern Red Sea Area, Saudi Arabia [and Dicussion]

Several mineral occurrences of lead, copper and zinc, which were found recently in Tertiary sedimentary rocks on the coastal plain that stretches along the eastern margin of the Red Sea in Saudi Arabia between Umm Lajj and Al Wajh, are shown to be confined to definite stratigraphic levels (beds of arkose, reefoid limestone, and conglomerates). The mineralization is probably controlled by tectonic features trending NNW-SSE, the direction of the Red Sea fault system. These tectonic features can be seen on aeromagnetic maps provided by recent low altitude aerial surveys. Similar mineral occurrences are known to exist on the opposite or western margin of the Red Sea at Um Gheig in Egypt. It is suggested that such mineralization took place in connexion with the formation of the Red Sea depression.