부산대학교 도서관

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.tecto.2008.08.002 Byline: Osman Parlak (a)(b), Tamer RizaoAlu (c), Utku BaAci (d), Fatih KaraoAlan (a), Volker Hock (e) Keywords: Ensimatic arc; Arc-forearc; Anatolia; Southern Neotethys; SSZ spreading Abstract: The southeast Anatolian ophiolites form discontinuous linear belts of oceanic fragments immediately north of the Bitlis-Zagros suture, which marks a continental collision zone between the Arabian platform to the south and the Taurides to the north. The Late Cretaceous ophiolites in the southeast Anatolia are represented by the KizildaA in the Hatay area, the Goksun and the Berit to the north of KahramanmaraA, A[degrees]spendere in the Malatya area and Komurhan-Guleman in the ElaziA area. The Goksun, Berit, A[degrees]spendere, Komurhan and Guleman ophiolites were attached to the base of the Tauride platform (i.e. the Malatya-Keban) along its northern active margin and intruded by the I-type calc-alkaline granitoids of Late Cretaceous age. In contrast, the KizildaA (Hatay) ophiolite was thrust over the Arabian passive margin in the south. The cumulate rocks in the ophiolites are represented by dunite, wehrlite, lherzolite, olivine clinopyroxenite, olivine gabbronorite, olivine gabbro, gabbronorite and gabbro. Highly magnesian olivines (Fo.sub.88 to 74) and pyroxenes (Mg#.sub.95 to 60) as well as highly calcic plagioclases (An.sub.95 to 68) from the cumulate rocks differ from oceanic equivalents, which mainly formed from a MOR basaltic melt. The order of crystallization in mineral phases, whole rock and mineral chemistry data from the cumulates suggest that the primary magma is compositionaly similar to that observed in modern island arc tholeiitic sequences. The volcanic and subvolcanic rocks exhibit tholeiitic compositions. Chondrite normalized REE, N-MORB normalized multi-element patterns and tectonic discrimination diagrams suggest the existence of two main types of parental basic magmas in the crustal rocks of the SE Anatolian ophiolites. These are (i) IAT series that characterize the KizildaA, Goksun, A[degrees]spendere, Komurhan and Guleman ophiolites and (ii) Low-Ti boninitic series known only in the KizildaA ophiolite. The geochemistry of the crustal rocks suggests that they formed in a suprasubduction zone tectonic setting, including arc-forearc environments in the southern Neotethys. These well-preserved plutonic oceanic crustal remnants mainly exhibit an intact ophiolite pseudostratigraphy and are overlain by a volcanic-sedimentary unit made up of alternations of basic to acidic extrusive rocks, debris flows, volcaniclastic sandstones and pelagic limestones, interpreted as a tholeiitic ensimatic island arc assemblage built on the suprasubduction zone type crust. The metamorphism of some of the ophiolites (i.e. Berit) in the SE Anatolia might be related to later stages of intraoceanic subduction during the evolution of the southern Neotethys. Author Affiliation: (a) Aukurova Aniversitesi, Jeoloji MuhendisliAi Bolumu, 01330 Balcali-Adana, Turkey (b) Adiyaman Aniversitesi, Mesleki ve Teknik EAitim Fakultesi, 02040 Adiyaman, Turkey (c) Sutcu A[degrees]mam Aniversitesi, Jeoloji MuhendisliAi Bolumu, 46100 KahramanmaraA, Turkey (d) Mersin Aniversitesi, Jeoloji MuhendisliAi Bolumu, Aiftlikkoy 33342, Mersin, Turkey (e) University of Salzburg, Department of Geology and Geography, A-5020 Salzburg, Austria Article History: Received 12 January 2008; Revised 22 June 2008; Accepted 7 August 2008