Ediacaran Sedimentary Rocks “so-called Hammamat” of the Egyptian Shield

Abstract

Ediacaran sedimentary rocks are widely distributed in the central and northern segments of the Eastern Desert of Egypt and in Sinai. These sedimentary rocks are considered syn- and/or post-orogenic molasse-type deposits that were accumulated in either foreland basins and in intramontane basins related probably to Najd strike-slip fault system. Ediacaran sedimentary rocks are commonly referred to as “Hammamat Sediments,” after the well-exposed historic exposure of such immature sediments at the Hammamat area in the central Eastern Desert. Ediacaran sedimentary rocks from other areas from the Eastern Desert and Sinai are different from the one described in Hammamat in terms of composition, tectonic setting, and rocks association and provenance of the sediments as delineated by recent work detrital zircon. In the central Eastern Desert, Ediacaran sedimentary rocks from Igla basin are characterized by its red color compared to the one in the Hammamat area, while the Ediacaran sedimentary rocks of the Kariem basin were deposited in intramontane strike-slip-related, while the equivalent sediments of the Hammamat area were deposited in a foreland setting. Unlike the Ediacaran sedimentary rocks of the central Eastern Desert of Egypt, the one in the northern segment of the Eastern Desert and in Sinai are commonly intercalated with volcanic rocks. However, the detrital zircon age patterns for the Ediacaran sedimentary rocks from the northern Eastern Desert and Sinai are different, which support the isolated nature of the Ediacaran basins. The deposition of the Ediacaran sedimentary rocks in isolated basins is not consistent with considering the Wadi Hammamat area as the type locality of these sedimentary rocks and so identifies them as “Hammamat Sediments.” The Ediacaran sedimentary rocks from each basin are expected to have unique features, which may be obscured by just identify these sediments as “Hammamat Sediments.”