Tiran Straits: The transfer zone between the Red Sea and the Gulf of Elat and its tectonic significance

Abstract A precipitous submarine horst is located between Sinai Peninsula and Tiran Island, but also between Hume Deep (1400 m) in northernmost Red Sea and Tiran Deep (1400 m), in the southernmost Gulf of Elat. The horst outcrops above sealevel in places, where corals built small reefs, trending NNE-SSW. The horst forms a structural transfer zone trending NNE-SSW and constrained by series of normal faults on both flanks. Transfer zones were repeatedly encountered to separate between axial grabens along regional rifts in East Africa and elsewhere while similar structures were observed in analog models. Transfer zones between grabens along axial rifts were attributed to oblique extension, consequently the occurrence of the Tiran transfer zone could indicate that geodynamic regime of oblique extension prevails in the northern Red Sea and exists also in Elat Rift. Tiran horst is structurally associated with the arcuate system of grabens and elongated salt diapirs that were encountered in the bathyal northern Red Sea, which swings from the Red Sea NW-SE orientation to the N-S trend of Elat Rift. The age of the initiation of the rifting and the contemporaneous ascent of its margin was attributed to late Miocene – early Pliocene, as indicated by extensive series of coralline terraces and by non-branching fluvial system on Tiran Island. The research did not encounter supporting evidence that the Elat Rift is a transform fault that branched off the Red Sea during the early-middle Miocene nor that Tiran Deep is a pull-apart basin.