The Oman Exotics: a key to the understanding of the Neotethyan geodynamic evolution |
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| Authors: | Alain Pillevuit Jean Marcoux Gérard Stampfli Aymon Baud |
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| Institution: | 1. Institut de Géologie et Paléontologie, Université de Lausanne, BFSH 2, CH-1015 LAUSANNE e-mail: Alain.Pillevuit@igp.unil.ch;2. Université Paris VII et Institut de Physique du Globe, 2 Pl. Jussieu, Tour 24/25, F-7525I PARIS e-mail: marcoux@ipgp.jussieu.fr;3. Institut de Géologie et Paléontologie, Université de Lausanne, BFSH 2, CH-1015 LAUSANNE e-mail: Gerard.Stampfli@igp.unil.ch;4. Musée de Géologie de Lausanne, BFSH 2, CH-1015 LAUSANNE e-mail: Aymon.Baud@sc.unil.ch |
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| Abstract: | AbstractThe study of the exotic blocks of the Hawasina Nappes (Sultanate of Oman) leads to give apposit data that allow us to propose a new paleogeographic evolution of the Oman margin in time and space. A revised classification of exotic blocks into different paleogeographical units is presented. Two newly introduced stratigraphic groups, the Ramaq Group (Ordovician to Triassic) and the Al Buda’ah Group (upper Permian to Jurassic) are interpreted as tilted blocks related to the Oman continental margin. The Kawr Group (middle Triassic to Cretaceous) is redefined and interpreted as an atoll-type seamount. The paleogeography and paleoenvironments of these units are integrated into a new scheme of the Neotethyan rifting history. Brecciae and olistoliths of the Hawasina series are interpreted to have originated from tectonic movements affecting the Oman margin and the Neotethyan ocean floor. The breccias of late Permian age were generated by the extension processes affecting the margin, and by the creation of the Neotethyan oceanic floor. The breccias of mid-late Triassic age coincide in time with the collision of the Cimmerian continents with Eurasia. In constrast, the breccias of late Jurassic and Cretaceous age are interpreted as resulting to the creation of a new oceanic crust (Semail) off the Oman margin. |
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| Keywords: | Sultanate of Oman Rifting of the Neotethys Hawasina Nappes exotics olistoliths atoll tilted blocks |
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