Geochemistry and tectonic significance of ophiolites along the İzmir–Ankara–Erzincan Suture Zone in northeastern Anatolia
Osman Parlak, Aydin Çolakoğlu, Cahit Dönmez, Hüseyin Sayak, Nail Yildirim, Aytekin Türkel, İlhan Odabaşi, 2013. "Geochemistry and tectonic significance of ophiolites along the İzmir–Ankara–Erzincan Suture Zone in northeastern Anatolia", Geological Development of Anatolia and the Easternmost Mediterranean Region, A. H. F. Robertson, O. Parlak, U. C. Ünlügenç
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The Ankara–Erzincan suture zone includes large bodies of ophiolite and ophiolitic melange in northeastern Anatolia. The ophiolitic bodies are (1) Refahiye (Erzincan), (2) Şahvelet (Erzurum), (3) Karadağ (Erzurum) and (4) Kırdağ (Erzurum). The ophiolite-related units include well-preserved sections of oceanic lithospheric and accretionary melanges with local blueschist assemblages. The ophiolite-related units in NE Anatolia are unconformably overlain by Campanian–Maastrichtian-aged sediments that were later imbricated with the ophiolitic rocks. Geochemical data for the individual ophiolite sections indicate a tholeiitic composition, depletion in Nb, enrichment in large ion lithophile elements, parallel to slightly depleted high field strength element patterns (compared with normal-mid ocean ridge basalt), and slightly light rare earth element-depleted to parallel rare earth element trends. These features suggest progressive source depletion towards island arc tholeiites and finally boninites. A fore-arc setting is proposed for the generation of the ophiolites. In contrast, the volcanic rocks from the mélange units exhibit tholeiitic to alkaline compositions and either depletion or enrichment of rare earth element and high field strength elements. Seamount-type alkaline and subduction-related tholeiitic basaltic rocks were apparently juxtaposed during subduction/accretion. Models involving either a single north-dipping subduction zone or two north-dipping subduction zones may be applicable. Both models involve the generation of supra-subduction zone-type ophiolites in a forearc setting, an accretionary prism (with blueschists) and a volcanic arc during the Late Cretaceous. The ophiolites, ophiolitic melange and related blueschists were emplaced either northwards onto the Pontide margin or southwards over the passive margin of the Tauride platform.
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Geological Development of Anatolia and the Easternmost Mediterranean Region
Anatolia and the easternmost Mediterranean region, especially Turkey, Cyprus and northern Syria, represent an excellent natural laboratory for the study of fundamental geological processes (e.g. rifting, seafloor spreading, ophiolite genesis and emplacement, subduction, exhumation and collision). Their interaction has created an intriguing array of deep-sea basins, microcontinents and suture zones.
The volume’s 22 papers include a large amount of new field-based information (much of it multidisciplinary and the product of teamwork). After an overview, the volume is divided into four sections: Late Palaeozoic–Early Cenozoic of the Pontides (northern Turkey); Late Palaeozoic–Early Cenozoic of the Taurides–Anatolides (central and southern Turkey); Late Cretaceous–Pliocene sedimentary basins and structural development (central Anatolia to the Mediterranean); Late Miocene–Recent Neotectonics (southern Turkey, Cyprus and northern Syria).
The volume will interest numerous academic researchers, those concerned with resources (e.g. hydrocarbons; mineral deposits) and also hazards (e.g. earthquakes), as well as advanced undergraduate and postgraduate students.