Türkiye Jeoloji Bülteni

Ophiolites and Ophiolitic Mélanges of Turkey: A Review

Abstract: The aim of the presented study is to review the ophiolites and ophiolitic mélanges of Turkeyand their importance for constraints on the evolution of the region. On the basis of the existing data, theophiolitic associations of Turkey are classified in three main groups.

1. Group comprises pre-Alpine ophiolites and mélanges located on the southern edge of theIstanbul zone. These associations are in Pre-Jurassic age, and represent ophiolitic sequences of the PontideSuture zone. The Karakaya complex represents pre-Alpine ophiolitic mélange and developed during theemplacement of the pre-Alpine ophiolites. The opening and closing ages and polarity of the Paleotethysis still a question. 

2. Group can be divided in two sub-belts and they are the Northern-Northeastern and the Southernsub 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-Akerasub-belt of the Lesser Caucasus Ophiolitic Belt (LCOB). This sub-belt directly represents the northernbranch of Neotethys. The ophiolites of this sub-belt represent dismembered ophiolitic sequences andtake place within the Late Cretaceous melanges. The southern sub-belt begins in the Marmaris area andcontinues eastward to the Hadim, Aladağlar, Tecer-Divriği, Erzurum, Kağızman areas, and then on to theVedi sub-belt of the LCOB. The ophiolitic outcrops of the Hınıs area and northeast of Lake Van, may bethe 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 beltshow similar characteristic features. Therefore the southern subbelt units may be tectonically transportedproducts of the northern sub-belt. The opening of the northern branch of Neotethys began in Triassic timein the west, in the Jurassic in the east. The closing of the northern branch of Neotethys was initiated in theLate Cretaceous and ended in pre-Middle Eocene time.

3. Group is represented by the Southern and Southeastern Anatolian Ophiolitic Belt (SAOB) comprisingJurassic-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-LateMiocene.

2. and 3 groups of ophiolites with mélanges are separated from one another by the Taurus UnmetamorphicAxis 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 inLate Cretaceous. The emplacement style for the ophiolitic units along NAOB and SAOB show a flowerstructure, on the basis of the presence of north- and south-facing overthrusts.