Geological Development of Anatolia and the Easternmost Mediterranean Region’

Downloaded from http://sp.lyellcollection.org/ by guest on September 30, 2021 Editorial introduction to ‘Geological Development of Anatolia and the Easternmost Mediterranean Region’ A. H. F. ROBERTSON1*, O. PARLAK2 &U.C.U¨ NLU¨ GENÇ 2 1School of GeoSciences, University of Edinburgh, West Mains Road, Edinburgh EH9 3JW, UK 2Department of Geological Engineering, Çukurova University, 01330 Balcalı, Adana, Turkey *Corresponding author (e-mail: [email protected]) The present set of 22 papers stems from the 7th of sedimentary basins during closure of several International Symposium on Eastern Mediterranean Mesozoic ocean basins and the related structural Geology that was held in Adana, Turkey, 18–22 development during Late Cretaceous to Pliocene October 2010. After its initiation in l992, in Adana time. Finally, Section 4 is devoted to aspects of this international conference has been held suc- the structural development of the region, mainly cessively in Jerusalem (Israel) in l995, Nicosia during the Pliocene–Quaternary (i.e. neotectonics) (Cyprus) in 1998, Isparta (Turkey) in 2001, Thessa- when the plate configuration was essentially as it is lonica (Greece) in 2004 and Amman (Jordan) in today. The area covered by each paper is shown in 2007. The Cyprus and Thessalonica conferences Figure 1. were followed by substantive publications, includ- The introduction by Robertson et al. covers the ing one with a focus on Cyprus (Panayides et al. southern part of Anatolia and the adjacent eastern- 2000) and another mainly concerned with the most Mediterranean region that was the main Balkan region (Robertson & Mountrakis 2006). A subject of the international conference. The main subset of the papers that were presented at the 7th focus is on Late Permian–Recent time. A review Adana meeting, together with some others, have of the Late Precambrian–Recent geological devel- been prepared and edited for the present volume. opment of the easternmost Mediterranean region is Anatolia and the surrounding region provide an published elsewhere (Robertson et al. 2012). excellent opportunity for the study of fundamental The authors discuss alternative interpretations geological processes, including rifting, seafloor of the Mesozoic–Cenozoic inter-relations of the spreading, ophiolite genesis and emplacement, col- various crustal units that make up the region. In par- lision, continental assembly and neotectonics. This ticular, they consider whether these should be inter- volume should interest a wide cross-section of interpreted as individual microcontinents separated by national researchers, including those concerned Mesozoic small ocean basins or as parts of larger with hydrocarbons, mineral deposits and seismic continental units (i.e. microcontinents). The Ana- risk, and also postgraduate students and advanced tolides in the north are generally interpreted as undergraduates. The papers highlight the role of the metamorphosed equivalents of the Taurides, fieldwork, the multidisciplinary nature of much of although different reconstructions exist. The Anato- the current research in the region, the role of team- lides are commonly seen as the northern, leading work and the strong contribution being made by edge of the Mesozoic Tauride–Anatolide continent young scientists. that subducted and underwent high-pressure/low- Following an introductory chapter, the volume temperature (HP/LT) metamorphism during Late is divided into four sections covering different Cretaceous–Early Cenozoic time. The Anatolides aspects of the region as a whole. The area discussed are divided into two parts, namely the HP/LT- mainly lies within Turkey, Cyprus and Syria. metamorphosed Afyon–Bolkar Dag˘ zone in the Section 1 is made up of a small number of papers south, which can be closely correlated with the that are mainly concerned with the Pontide belt of Taurides, and the very HP/LT Tavs¸anlı Zone northern Turkey. Section 2 is concerned with the further north, which also shows some affinities geological development of the Tauride and Anato- with the Taurides but is less well understood. The lide belts of central and southern Anatolia, especially Kırs¸ehir Massif is interpreted as a rifted continental the Triassic–Jurassic period of rifting and pas- block that was separated from a larger Tauride con- sive margin development and the Late Cretaceous tinent to the south by a Mesozoic oceanic basin period of ophiolite genesis and emplacement. known as the Inner-Tauride Ocean. However, Section 3 is mainly concerned with the formation uncertainties remain, including the reconstruction From:Robertson, A. H. F., Parlak,O.&U¨ nlu¨ genç, U. C. (eds) 2013. Geological Development of Anatolia and the Easternmost Mediterranean Region. Geological Society, London, Special Publications, 372,1–7. First published online March 21, 2013, http://dx.doi.org/10.1144/SP372.23 # The Geological Society of London 2013. Publishing disclaimer: www.geolsoc.org.uk/pub_ethics Downloaded from http://sp.lyellcollection.org/ by guest on September 30, 2021 2 A. H. F. ROBERTSON ET AL. Fig. 1. Main tectonic subdivision of Anatolia and the easternmost Mediterranean region showing the approximate areas covered by each of the papers in this volume. of the Anatolides in western Anatolia and the Bitlis timing of intrusion of Variscan and Cimmerian and Pu¨tu¨rge massifs in SE Anatolia. The authors use granites and associated meta-sedimentary rocks in their preferred regional reconstructions as a basis for the easternmost Pontides. They show that one or palaeogeographical sketch maps for Permian to more crustal units rifted from Gondwana during Miocene time. the Early Palaeozoic and then drifted northwards, followed by amalgamation with Eurasia during Late Palaeozoic time. The emplacement of the gran- Section 1: Late Palaeozoic–Early Cenozoic itic rocks is believed to have been associated with of the Pontides high-temperature metamorphism of sedimentary country rocks in the roots of a magmatic arc. Juras- The Pontides exhibit a long history of mainly sic granites were intruded later, related to continu- active margin processes from Late Palaeozoic to ing northward subduction and back-arc rifting Early Cenozoic time. There is currently much inter- along the Eurasian margin. est in determining the timing of assembly of the Parlak et al. present a detailed account, sup- Pontide belt and identifying where the component ported by new geological mapping and also petro- tectonic units originally came from. Ustao¨mer graphical and geochemical evidence of the nature et al. use U–Pb dating of zircons to determine the and origin of the Mesozoic ophiolite that are Downloaded from http://sp.lyellcollection.org/ by guest on September 30, 2021 INTRODUCTION 3 widely exposed in the Eastern Pontides. Although the Taurides–Anatolides, including rifting, ophio- dismembered, complete ophiolite sequences can lite genesis, subduction and collision. be recognized, as explained for each of the main O¨ zbey et al. give a detailed description and ophiolitic massifs. The associated tectonostratigra- interpretation of the westernmost outcrop of the phy is also summarized including the rocks above Tavs¸anlı zone. Based on detailed mapping, they and below the ophiolites. Geochemically, all of explain the lithostratigraphy, structure and geolog- the ophiolites are of supra-subduction zone type ical development, supported by geochemical data and can be related to northward subduction of a for a range of igneous and sedimentary rocks. Tak- Mesozoic oceanic basin, generally known as the ing account of regional comparisons, they interpret I˙zmir–Ankara–Erzincan Ocean. An outstanding the Tavs¸anlı Zone as a continental fragment that issue is the age (or ages) of the ophiolites, since both rifted from Gondwana during the Triassic and Jurassic and Cretaceous ages have been reported drifted northward until it accreted to the Eurasian from ophiolitic rocks in the Pontides as a whole. margin, represented by the Sakarya continent, dur- The closure of the Mesozoic I˙zmir–Ankara– ing the Late Cretaceous. The meta-volcanic rocks Erzincan Ocean involved subduction, collision and are seen as largely related to Triassic rifting of post-collisional magmatism. Gu¨lmez et al. discuss a continental fragment (or fragments) from the the Middle Eocene magmatic rocks of the western- Tauride–Anatolide continent. A subduction chem- most Pontide region. The authors present a large ical signature in some of the volcanic rocks is body of field, petrographical, geochemical and explained by melting of upper mantle lithosphere isotopic data for the magmatic rocks. The geo- that was chemically influenced by previous (unre- chemisty is interpreted and modelled in terms of lated) subduction in the region. magma source and crystallization processes. Pre- In contrast to the western and central Taurides, viously both subduction and post-collisional set- the eastern Taurides have received relatively little tings have been proposed to explain these rocks. attention but are highlighted in this volume. The Based on new field, petrological and geochemi- eastern Taurides are difficult to interpret owing to cal evidence, the authors favour a post-collisional an array of neotectonic strike-slip faults. A key setting involving magmatism triggered by slab area is the Gu¨ru¨n carbonate platform, centred on break-off. In this case the˙ Izmir–Ankara–Erzincan the town of Gu¨ru¨n, and adjacent relatively allo- Ocean sutured and associated slab break-off chthonous units including ophiolites and

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