Document generated on 09/25/2021 3:31 a.m. Geoscience Canada Journal of the Geological Association of Canada Journal de l’Association Géologique du Canada The Ayyubid Orogen An Ophiolite Obduction-Driven Orogen in the Late Cretaceous of the Neo-Tethyan South Margin A.M. Celâl Şengör and Joann Stock Volume 41, Number 2, 2014 Article abstract A minimum 5000-km long obductiondriven orogeny of medial to late URI: https://id.erudit.org/iderudit/1025343ar Cretaceous age is located between Cyrenaica in eastern Libya and Oman. It is herein called the Ayyubid Orogen after the Ayyubid Empire that covered much See table of contents of its territory. The Ayyubid orogen is distinct from other Alpide orogens and has two main parts: a western, mainly germanotype belt and an eastern mainly alpinotype belt. The germanotype belt formed largely as a result of an Publisher(s) aborted obduction, whereas the alpinotype part formed as a result of successful and large-scale obduction events that choked a nascent subduction The Geological Association of Canada zone. The mainly germanotype part coincides with Erich Krenkel’s Syrian Arc (Syrischer Bogen) and the alpinotype part with Ricou’s Peri-Arabian Ophiolitic ISSN Crescent (Croissant Ophiolitique péri-Arabe). These belts formed as a consequence of the interaction of one of the now-vanished Tethyan plates and 0315-0941 (print) Afro-Arabia. The Africa-Eurasia relative motion has influenced the orogen's 1911-4850 (digital) evolution, but was not the main causative agent. Similar large and complex obduction-driven orogens similar to the Ayyubids may exist along the Explore this journal Ordovician Newfoundland/ Scotland margin of the Caledonides and along the Ordovician European margin of the Uralides. Cite this article Şengör, A. C. & Stock, J. (2014). The Ayyubid Orogen: An Ophiolite Obduction-Driven Orogen in the Late Cretaceous of the Neo-Tethyan South Margin. Geoscience Canada, 41(2), 225–254. All Rights Reserved © The Geological Association of Canada, 2014 This document is protected by copyright law. Use of the services of Érudit (including reproduction) is subject to its terms and conditions, which can be viewed online. https://apropos.erudit.org/en/users/policy-on-use/ This article is disseminated and preserved by Érudit. Érudit is a non-profit inter-university consortium of the Université de Montréal, Université Laval, and the Université du Québec à Montréal. Its mission is to promote and disseminate research. https://www.erudit.org/en/ GEOSCIENCE CANADA Volume 41 2014 225 HAROLD WILLIAMS SERIES called the Ayyubid Orogen after the otype, et une bande orientale princi- Ayyubid Empire that covered much of palement alpinotype. La bande ger- its territory. The Ayyubid orogen is dis- manotype s’est formée en grande par- tinct from other Alpide orogens and tie à la suite d'une obduction avortée, has two main parts: a western, mainly tandis que la partie alpinotype s’est for- germanotype belt and an eastern main- mée par des épisodes d’obduction à ly alpinotype belt. The germanotype grande échelle qui ont étranglé une belt formed largely as a result of an zone de subduction naissante. La par- aborted obduction, whereas the alpino- tie principalement germanotype coïn- type part formed as a result of suc- cide avec l’arc syrien d’Erich Krenkel cessful and large-scale obduction (Syrischer Bogen), alors que la partie events that choked a nascent subduc- alpinotype correspond au croissant The Ayyubid Orogen: An tion zone. The mainly germanotype ophiolitique péri-Arabe de Ricou Ophiolite Obduction-Driven part coincides with Erich Krenkel’s (Croissant ophiolitique péri-Arabe). Syrian Arc (Syrischer Bogen) and the Ces bandes se sont formées par l'inter- Orogen in the Late alpinotype part with Ricou’s Peri-Ara- action de l'une des plaques de la Cretaceous of the bian Ophiolitic Crescent (Croissant Téthys, maintenant disparues, avec Neo-Tethyan South Margin Ophiolitique péri-Arabe). These belts l’Afro-Arabie. Le mouvement relatif formed as a consequence of the inter- Afrique-Eurasie a influencé l'évolution action of one of the now-vanished de l'orogène, mais ça n’a pas été le A.M. Celâl Şengör1 and Joann Stock2 Tethyan plates and Afro-Arabia. The principal facteur. Des orogènes Africa-Eurasia relative motion has grandes et complexes résultant de 1İstanbul Teknik Üniversitesi, Maden influenced the orogen's evolution, but mécanismes d’obduction similaires à Fakültesi, Jeoloji Bölümü was not the main causative agent. Simi- l’orogène Ayyoubide peuvent exister le ve Avrasya Yerbilimleri Enstitüsü lar large and complex obduction-driven long de la marge des Calédonides de Ayazağa 34469 İstanbul, Turkey orogens similar to the Ayyubids may l'Ordovicien de Terre-Neuve/Écosse E-mail: [email protected] exist along the Ordovician Newfound- et le long de la marge européenne des land/Scotland margin of the Cale- Uralides de l'Ordovicien. 2California Institute of Technology donides and along the Ordovician Division of Geological and Planetary European margin of the Uralides. INTRODUCTION Sciences, MC 170-25 That the entire Eastern Mediterranean 1200 E. California Blvd. SOMMAIRE Sea, east of the Gulf of Sirte (Gulf of Pasadena, CA 91125 USA Entre la Cyrénaïque dans l'est de la Sidris; ancient ‘Great Sirte’: Σύρτις Libye et Oman, se trouve un ceinture μεγάλη or Syrtis major), is framed by late “The coastal lands of the southeastern orogénique d’au moins 5 000 km de Cretaceous and Cainozoic orogenic Mediterranean are little-known from the longueur créé par obduction au Cré- structures has been known ever since viewpoint of their regional tectonics” tacé moyen et tardif. Nous le nom- the great German geologist Erich Erich Krenkel 1924 mons ici l’orogène ayyoubide d’après Krenkel coined the term ‘der syrische SUMMARY l'empire ayyoubide qui couvrait une Bogen’ (= the Syrian Arc); ‘An examina- grande partie de son territoire. tion of all the observations leaves no A minimum 5000-km long obduction- L'orogène ayyoubide qui est distincte doubt that the Levantine basin is sur- driven orogeny of medial to late Creta- des autres orogènes alpides, comporte rounded by a unified, nowhere interrupted ceous age is located between Cyrenaica deux parties principales : une bande fold bundle. It may have the name “the in eastern Libya and Oman. It is herein occidentale, principalement german- Syrian Arc”. In Middle Syria, a new Geoscience Canada, v. 41, http://dx.doi.org/10.12789/geocanj.2014.41.042 © 2014 GAC/AGC® 226 Ir niden Chott el Djerid and Chott el Fedjedj in Mar. a Klein - Asien o central Tunisia, the ‘Gafsa Ranges’ of Inn enzo ne a Rndzneir Krenkel (1943, see his fig. 7), and con- ittelzo e G au - D Mn indjar . S Dj sidered the Cyrenaican structures A. Nordsyrische Vorke t tnde (which he called the ‘Barka folds’: n . Irani y ern og en e Cp B Mesopo Krenkel 1924, pp. 276, 278–279) as la d d e e Euphr t A Tafel n i r r hab G belonging to an ‘inner’ zone of the u a a ns T Aaij Cyp ern tam e Syrian Arc. Krenkel held on to the n H. non io in e interpretation of the ‘Chott-folds’ (i.e. nl Atibannskusbo en Liba g am Da g Beirut his ‘Gafsa Ranges’) as the westernmost Bagdad Mittelmeer o Bekaa D. representatives of the Syrian Arc B Tulul Nordarabische throughout his professional life (see Gr. r Krenkel 1938, p. 1558; 1943, p. 56; e Hauran Steppe r h Jo dan - 1957, p. 32), despite the fact that the c S y r i s J. onset of deformation in the Chott Alexandria Gazza W. rh Totes Meer Si n a region is much younger, namely Miocene (see his map in Krenkel 1938, ha Mag ar 3 el ek Jl a Kairo plate 44 ). Elsewhere, he indicated that ab Skizze Ro s S. Isthmus - Ar Abu ah Dj. ch . the inner zones in Cyrenaica had sunk W Wüste der Faltungsregion des östlichen Mittel- below the sea. Krenkel correctly point- meeres mit dem Syrischen Bogen S . aba u ed out that the deformation in the Syr- e Sinai Hedjas z W. Ar - Gr Faltenzüge, schematisch - ba ian Arc had started in the Senonian G ah r r Grabenbrüche a Aka B a ije b e (Krenkel 1925, p. 102) and lasted into n Überschiebungen Basalt the Miocene–Pliocene. Nil Eritreischer- 0 100 200 300 km As to the geological structure Graben of the Syrian Arc, Krenkel (1924) Krenkel, Afrika pointed out that it was a folded moun- Figure 1. Krenkel’s map of the Syrian Arc from his Geologie Afrikas (Krenkel 1925, tain range resembling in general the p. 101). The Libyan and western Egyptian parts are not shown here. Translation of Jura Mountains in Switzerland and the legend: ‘ Sketch of the folded region of the Eastern Mediterranean with the France. He nevertheless emphasized, Syrian Arc. Fold trains, schematic; Graben faults; Overthrusts; Basalt.’ On the fig- however, that the overall shortening ure itself, Syrischer Bogen is Syrian Arc, Damaskusbogen means Damascus or Dama- seemed less both in the individual folds scene Arc. Nordsyrische Tafel is north Syrian table or plate; Cypernbogen is Cyprus Arc, and in the concentration of individual Tauriden is Taurides, separated into Innenzone = inner zone, Mittelzone = middle zone fold trains in any given cross-section. and Randzone = marginal zone. The Red Sea is termed Eritreischer Graben on this fig- The fold axes, he observed, plunged ure. The Isthmuswüste is the Isthmian Desert, Totes Meer is the Dead Sea and the Vor- and re-emerged in short distances cre- ketten der Iraniden is fore-ranges of the Iranides. The abbreviations, A., D., H., J. and ating short, rounded plan views of Mar., represent the cities of Antakya (Turkey; ancient Antioch), Damascus, Hama folds.