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    Characteristics and geochemistry of Precambrian ophiolites and related volcanics from the Istanbul-Zonguldak Unit, Northwestern Anatolia, Turkey: following the missing chain of the Precambrian South European suture zone to the east
    (Elsevier, 2004) Yigitbas, E; Kerrich, R; Yilmaz, Y; Elmas, A; Xie, QL
    The Precambrian metamorphic basement of the Istanbul-Zonguldak Unit (IZU), NW Anatolia, Turkey, is represented by the Sunnice Group, composed essentially of four different metamorphic assemblages: (1) Cele metaophiolite, (2) Yellice metavolcanics, (3) Demirci metamorphics, and (4) Dirgine metagranite. The field relations and structural characteristics of these units were studied and representative geochemical analyses of Cele metaophiolite and related volcanics were obtained from the Sunnice, Almacik, and Arrnutlu areas. Collectively, the results are interpreted as the Cele Magmatic suite displaying disrupted components of a complete suprasubduction ophiolite. The Yellice metavolcanic sequence contains fragments of both an intra oceanic island arc and a back-arc basin association built on the ophiolite. The Demirci metamorphics, represent reworked continental fragments forming the base of the metamorphic massifs. These three different metamorphic units were intruded, after their amalgamation, by the Dirgine granitic pluton dated at 570-590 Ma [Geol. Mag. 136 (5) (1999) 579; Int. J. Earth Sci. (Geol. Rundsch) 91 (3) (2002) 469]. The metamorphic tectonic units and the metagranite are collectively overlain by a thick Lower Ordovician to Carboniferous sedimentary cover known as the Istanbul-Zonguldak succession. The collisional event which led to the amalgamation of the different tectonic entities is partly penecontemporaneous with the Pan-African orogeny supporting the view that the basement of the IZU formed a link between the Pan-African and Trans-European suture zones. (C) 2004 Elsevier B.V. All rights reserved.
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    Comment on Tectonic evolution of the Intra-Pontide suture zone in the Armutlu Peninsula, NW Turkey by Robertson and Ustaomer
    (Elsevier, 2005) Elmas, A; Yigitbas, E
    [Anstract Not Available]
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    Major neotectonic features of eastern Marmara region, Turkey
    (John Wiley & Sons Ltd, 2004) Yigitbas, E; Elmas, A; Sefunç, A; Özer, N
    Eastern Marmara region consists of three different morphotectonic units: Thrace-Kocaeli Peneplain (TKP) and Camdag-Akcakoca Highland (CAH) in the north, and Armutlu-Almacik Highland in the south of the North Anatolian Fault Zone (NAFZ). The geologic-morphologic data and seismic profiles from the Sakarya River offshore indicate that the boundary between the TKP in the west and 1 CAH in the east is a previously unrecognized major NNE-SSW-trending strike-slip fault zone with reverse component. The fault zone is a distinct morphotectonic corridor herein named the Adapazari-Karasu corridor (AKC) that runs along the Sakarya River Valley and extends to its submarine canyon along the southern margin of the Black Sea in the north. It formed as a transfer fault zone between the TKP and CAH during the Late Miocene; the former has been experiencing extensional forces and the latter compressional forces since then. East-West-trending segments of the NAFZ cuts the NE-SW-trending AKC and their activity has resulted in the formation of a distinct fault-bounded morphology, which is characterized by alternating E-W highlands and lowlands in the AKC. Furthermore, this activity has resulted in the downward motion of an ancient delta and submarine canyon of the Sakarya River in the northern block of the NAFZ below sea level so that the waters of the Black Sea invaded them. The NE-SW-trending faults in the AKC were reactivated with the development of the NAFZ in the Late Pliocene, which then caused block motions and microseismic activities throughout the AKC. Copyright (C) 2004 John Wiley Sons, Ltd.