الفهرس | Only 14 pages are availabe for public view |
Abstract The study area encompasses the zone around CED/SED contact, representing the southern part of the Egyptian Central Eastern Desert (CED) and the northern part of the Southern Eastern Desert (SED), along the western coast of the Red Sea between latitudes 24˚ 10ˊ N and 25˚ 10ˊ N, and longitudes 33˚ 40ˊ and 35˚ 15ˊ E. The area is covered by different basement and sedimentary units. The Precambrian basement rocks are commonly grouped under two major tectonostratigraphic; the infrastructural base and suprastructural. The infrastructural base comprises gneisses and migmatites that are 800–600 Ma, and crop out in dome structures (e.g., the Hafafit dome). The suprastructural overlying units include an 850– 700 Ma oceanic assemblage of mostly greenschist facies ophiolite complexes and coeval ”arc assemblage” that involve volcaniclastic and volcanic rocks intercalated with epiclastic sedimentary rocks. The oceanic assemblage is intruded by (i) Cryogenian I-type granitoids (i.e., Older Granitoids, 710–610 Ma), and (ii) Ediacaran A-type granitoids (i.e., Younger Granitoids, 630–592 Ma). Locally, the rock sequences to the north of the CED/SED boundary are overlain by a succession of 630–592 Ma old, calcalkalic Dokhan arc volcanic rocks. Moreover, an abundance of Phanerozoic alkaline volcanic rocks (i.e., Natash volcanics) to the south of the CED/SED boundary. |