Stratigraphic and Tectonic Implications of Uranium-Series-Dated Coral Reefs from Uplifted Red Sea Islands

Corals from raised reef terraces on two islands (Zabargad and Northern Brother), considered to have been tectonically uplifted in connection with the Red Sea rifting, were dated with the U-series method. At Zabargad, there are at least three systems of raised coral reefs. The oldest terrace (>290,00&300,000 yr B.P.) is found at + 10 to + 15 m. A 200,000 yr B.P. high-sea stand is recorded by a terrace relict at + 17 m on peridotite bedrock; the youngest system (125,000-138,000 yr B.P.) is very well represented around the island, with terraces at about +6 to +8 m. Corals from Northern Brother yield ages of 132,000-135,000 and 204,000 yr B.P. suggesting the existence of two systems of interglacial raised reefs. Both islands appear to have been tectonically quite stable since at least 125,000 yr B.P. 6 1w1 University of Washington.