Ophiolites and Ophiolitic Mélanges of Turkey: A Review

Authors : Ali Yılmaz, Hüseyin Yılmaz

Pages : 61-114

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Publication Date : 2013-04-01

Article Type : Other

Abstract :The aim of the presented study is to review the ophiolites and ophiolitic mélanges of Turkey   and their importance for constraints on the evolution of the region. On the basis of the existing data, the  ophiolitic associations of Turkey are classified into three main groups. 1. Group comprises pre-Alpine ophiolites and mélanges located on the southern edge of the  Istanbul zone. These associations are in Pre-Jurassic age, and represent ophiolitic sequences of the Pontide  Suture zone. The Karakaya complex represents pre-Alpine ophiolitic mélange and developed during the  emplacement of the pre-Alpine ophiolites. The opening and closing ages and polarity of the Paleotethys  is still a question. 2. Group can be divided into two sub-belts and they are the Northern-Northeastern and the Southern  sub belt. They are allied to the North Anatolian Ophiolitic Belt (NAOB). The northern-northeastern subbelt  extends from Izmir to eastward, continuing as the Ankara-Erzincan zone and as the Sevan-Akera  sub-belt of the Lesser Caucasus Ophiolitic Belt (LCOB). This sub-belt directly represents the northern  branch of Neotethys. The ophiolites of this sub-belt represent dismembered ophiolitic sequences and take place within the Late Cretaceous melanges. The southern sub-belt begins in the Marmaris area and  continues eastward to the Hadim, Aladağlar, Tecer-Divriği, Erzurum, Kağızman areas, and then on to the  Vedi sub-belt of the LCOB. The ophiolitic outcrops of the Hınıs area and northeast of Lake Van, may be  the southernmost products of the southern sub-belt of the NAOB associations. In the framework of age,  composition, and tectonic setting ophiolites and mélanges of the southern sub-belt and northern sub belt  show similar characteristic features. Therefore the southern subbelt units may be tectonically transported  products of the northern sub-belt. The opening of the northern branch of Neotethys began in Triassic time  in the west, in the Jurassic in the east. The closing of the northern branch of Neotethys was initiated in the  Late Cretaceous and ended in pre-Middle Eocene time.  3. Group is represented by the Southern and Southeastern Anatolian Ophiolitic Belt (SAOB) comprising  Jurassic-Lower Cretaceous ordered ophiolitic sequences and Late Cretaceous mélanges. Opening of the southern Neotethys began in Triassic and closure began in the Late Cretaceous and ended in pre-Late  Miocene.  2. and 3 groups of ophiolites with mélanges are separated from one another by the Taurus Unmetamorphic  Axis of the Anatolide-Tauride block These ophiolites together include Mid Ocean Ridge Basalt (MORB)  and Supra-subduction zone (SSZ) type ophiolites, emplaced along double northward subduction zones in  Late Cretaceous. The emplacement style for the ophiolitic units along NAOB and SAOB show a flower  structure, on the basis of the presence of north- and south-facing overthrusts. 
Keywords : Alpine ophiolites, mélanges, pre- Alpine ophiolites, sutures