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

Abstract

AbstractThe 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–D3 and M1–M2), whereas the Post‐Ra'ayan volcanic rocks were only affected by the D3 and M2 events. D1 is an extensional event and is connected to the late Rodinia break‐up (∼Tonian; 900–870 Ma). The M1 metamorphism 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 M2 affected the youngest Post‐Ra'ayan volcanic rocks and other stratigraphic successions. The compressive D2 and D3 events were coeval with the accretion of dismembered terranes in the assembly of Gondwana. D2 can be linked to the Tonian–Cryogenian arc‐arc assembly (∼880–760 Ma; in Elat and Sinai), whereas D3 and the accompanying M2 is constrained to 622–600 Ma (Ediacaran).