Pleistocene scleractinian corals from Marsa Alam area, Red Sea Coast, Egypt: systematics and biogeography
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Pleistocene scleractinian corals from Marsa Alam area, Red Sea Coast, Egypt: systematics and biogeography Mahmoud A. Kora • Salah N. Ayyad Heba M. El-Desouky
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Received: 20 January 2013 / Accepted: 22 February 2014 Ó Akademie der Naturwissenschaften Schweiz (SCNAT) 2014
Abstract Coral reef terraces are investigated in five localities around Marsa Alam on the Egyptian Red Sea Coast. The reefal limestones and the alternating terrigenous clastics are assigned to the Pleistocene Samadai Formation. Sixty-one scleractinian coral species belonging to 25 genera and 10 families were identified. Thirteen scleractinian species, for the first time recorded from the Egyptian Red Sea coastal plain, are systematically studied. The stratigraphic distribution of these fossils is illustrated and discussed. Six species are extended to the Miocene and five other species are recorded from the Pliocene and still living in the present Red Sea and the Indo-Pacific. The geographic distributions of the identified coral species are illustrated on maps. These maps show that, all the identified coral species are distributed only throughout the IndoPacific realm, increasing from the central part westwards across the Indian Ocean to the Red Sea. There are four species that are restricted to the Red Sea, Arabian region and West Indian Ocean. Keywords Scleractinian corals Red Sea Pleistocene Palaeogeography Egypt
Introduction The study area lies along the Red Sea coastal plain between latitudes 24°300 and 25°300 N in the Marsa Alam area, forming a strip that stretches 95 km along the coast and ranging in width from 1 to 6 km. The area is covered by M. A. Kora (&) S. N. Ayyad H. M. El-Desouky Department of Geology, Faculty of Science, Mansoura University, Mansoura, Egypt e-mail: [email protected]; [email protected]
Miocene and younger deposits with conspicuously raised coral reef terraces of Pleistocene age which run parallel to the shore line in a discontinuous pattern and at different elevations (Fig. 1). The Pleistocene succession is represented mostly by conglomerates that grade laterally or vertically into reefal limestones usually referred to as the Samadai Formation of Philobbos et al. (1989), which is conformably overlain by the Pleistocene raised beaches and coral reefs. The present study extends using the Samadai Formation to include the overlying raised beaches and coral reefs, as there is no remarkable lithological difference between them and it is rather difficult to separate them on maps. The studied succession overlies unconformably the Pliocene Shagra Formation or the Miocene Samh Formation (Fig. 2). The aim of the present work is to shed more light on the systematics and palaeobiogeography of the scleractinian corals building the Pleistocene succession in the Marsa Alam area. To carry out this study, five stratigraphic successions have been investigated, measured and sampled. The selected localities include Wadi Abu Dabbab and Wadi Asalay (north of Marsa Alam) and Wadi Samadai, Sharm El-Fuquiri and Sharm El-Lul
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