ABSTRACT: The Geology and Geochemistry of the Red Sea, Saudi Arabia, and Its Relation to the Pacific Region
Hassan Othman Sindi
Geological, geochemical, and comparative studies were carried out on the Red Sea, part of the multirift Circum-Pacific region and other oceanic crust areas represented by MORB-type basalts. The Red Sea geochemical data indicate four magma groups related to the volcanic ridges and the rift floor. This area has different ages and assorted rock compositions ranging from calc-alkaline to sub-alkaline affinities. The Red Sea is formed by the fastest spreading rate and the rotation of Arabia away from Africa in four phases affecting the Indian plate and the Bitils/Zagros sutures. This recent developed ocean consists of shallow continental shelves, a wide main trough (600-1000 m depth), and a narrow (4-5 km wide) axial trough (2000 m depth) that is formed by seafloor spreading c rrently active for plate separation. This axial trough is related to some of the erupted low temperature lava flows on the Afro-Arabian shields. The Red Sea inner floor is occupied by hot points, upwelling areas, and pillowed volcanoes forming elongated hills. The 15 km crustal thickness of the Red Sea shelf with a metamorphic and thick sedimentary basin that is salt-filled suffers major and minor structures of tilted, faulted, foliated, and sheared zones with general NW-SE strikes. Eight m.y. ago, 75% of this sea was opened, the Gulf of Suez graben remained essentially stagnant, and the Gulf of Agaba-Levant became active and extended to the Dead Sea Arava Rift.
AAPG Search and Discovery Article #90097©1990 Fifth Circum-Pacific Energy and Mineral Resources Conference, Honolulu, Hawaii, July 29-August 3, 1990