The phanerozoic palaeotectonics of Turkey. Part I: an inventory

Abstract

This paper presents an inventory of the relevant information to delineate the Tethyside sutures and the continental blocks they stitch in Turkey and to summarise their history. A palinspastic palaeogeographic/palaeotectonic interpretation is reserved for the second part of this paper and in a third paper we hope to deal with its neotectonic episode. In Turkey there are two groups of Tethyside sutures: Cimmeride sutures corresponding to the closure of the Palaeo-Tethys and its dependencies such as back-arc basins and Alpide sutures corresponding to the welding lines of the Neo-Tethyan oceans. During the Palaeozoic, the entire area of Turkey was a part of the northern margin of Gondwana-Land, along which subduction seems to have been continuous at least since the Devonian, possibly since the Ordovician. During the early Carboniferous a Lycaonian back-arc basin disrupted this margin from the western end of the country to the eastern part of the Taurus Mountains. In the latest Permian another extensional basin began opening the Karakaya Basin, which seems to have been coeval and in places confluent with the western segment of the northern branch of the Neo-Tethys in Turkey. This rifting largely dislodged the future pieces of the Sakarya Continent and the Rhodope–Pontide Fragment from Gondwana-Land. Another region of Permian extension rimmed the present-day eastern Mediterranean and extended via the Bitlis Suture in southeastern Turkey into the Zagros collision zone in Iran. Finally, the body today constituting the Sakarya Continent rifted off the southern margin of the Rhodope–Pontide Fragment opening what has been called the Intra-Pontide Ocean. These various rifting events created only two independent continental pieces: the Sakarya Continent and the Kirsehir Block, the latter originally attached to the eastern end of the Bitlis Massif. Subduction commenced during the Aptian all along the southern margin of the Sakarya Continent and Laurasia where the Rhodope–Pontide Fragment formed a Sumatra-type continental margin arc. Successive rifting events north of this arc eventually opened the Black Sea, isolating the Rhodope–Pontide Fragment from Laurasia. In the main body of the text we provide the data on which such interpretations are based and evaluate some alternative suggestions.