Tonian–Ediacaran Tectonometamorphic History of the Sa'al Complex, Sinai(Egypt): Implications for the Tectonostratigraphic Framework of the Northern Arabian–Nubian Shield

The Sa’al Metamorphic Complex(SMC; southern Sinai) encompasses the oldest arc rocks in the Arabian–Nubian Shield, comprising two non-consanguineous metavolcanic successions(the Agramiya Group and the Post-Ra’ayan Formation) separated by the metasediments of the Ra’ayan Formation. It experienced three distinct deformational events(D1–D3) and two low-medium grade regional metamorphic events(M1–M2). The Agramiya Group and the Ra’ayan Formation experienced all tectonometamorphic events(D1–D3and M1–M2), whereas the Post-Ra’ayan volcanic rocks were only affected by the D3and M2events. D1is an extensional event and is connected to the late Rodinia break-up(～Tonian; 900–870 Ma). The M1metamorphism variably affected the older Agramiya Group, the rhyolitic tuffs experiencing lower to upper greenschist facies conditions and the basic and intermediate volcanic rocks undergoing amphibolite facies metamorphism. The Ra’ayan Formation metasediments experienced upper greenschist to amphibolite facies metamorphism. The upper greenschist facies M2affected the youngest Post-Ra’ayan volcanic rocks and other stratigraphic successions. The compressive D2and D3events were coeval with the accretion of dismembered terranes in the assembly of Gondwana. D2can be linked to the Tonian–Cryogenian arc-arc assembly(～880–760 Ma; in Elat and Sinai), whereas D3and the accompanying M2is constrained to 622–600 Ma(Ediacaran).