Laser Ablation Inductively Coupled Plasma Mass Spectrometry U-Pb Dating of Detrital and Magmatic Zircons of Glacial Diamictites and Pebbles in Late Ordovician Sediments of the Taurides and Southeast Anatolian Autochthon Belt, Turkey: Indications for Their Arabian-Nubian Provenance

Late Ordovician (Hirnantian) glacio-marine deposits in the Central and Eastern Taurides and Southeast Anatolian Autochthon Belt (SAAB) in Turkey are mainly composed of diamictites, subrounded granitic pebbles, and rounded/subrounded lonestone pebbles. The granitic pebbles are dated as 576.5 ± 3.3, 576.7 ± 5.7, 598.4 ± 7.5, 717.5 ± 8.0, 789.5 ± 3.7, and 964.6 ± 4.6 Ma. The geochemical signatures and dated granitic pebbles in the Central and Eastern Taurides are interpreted to have been derived from the Late Neoproterozoic granitoids/metagranitic rocks of the Arabian-Nubian Shield (ANS; the Sinai Peninsula and the Eastern Desert of Egypt). The youngest 206Pb/238U ages in the diamictites (499.1 ± 4.2 Ma in the SAAB, 530.5 ± 5.3 Ma in the Eastern Taurides, and 562.5 ± 5.4 Ma in the Central Taurides) and in the lonestones (528.2 ± 4.5 Ma in the Central Taurides, 530.8 ± 5.2 Ma in the Eastern Taurides) indicate that detrital zircons were directly transported mainly from the northern margin of Gondwana and/or Arabia during the Late Ordovician, not from peri-Gondwanan parts of the European margin. Kernel/probability density diagrams of zircon ages from the lonestone pebbles in the Eastern and Central Taurides are interpreted as evidence for their derivation from Late/Middle Cambrian siliciclastic rocks in the Israeli part of the Sinai Peninsula. The provenance of detrital zircon populations in the diamictites in the Central and Eastern Taurides is directly correlated with magmatic activity of the Elat (Taba)–Feiran island arc, the Sa’al island arc, and the postcollisional magmatic suites in the Sinai Peninsula (Egypt). However, the corresponding successions in the SAAB have more abundant Late Cryogenian age components, suggesting the Ha’il/Afif/Ad Dawadimi/Ar-Rayn terranes of the eastern Arabian Shield as their provenance. These distinctive age patterns indicate that glacio-marine successions in the SAAB had different paleogeographic positions than their equivalent units in the Central and Eastern Taurides during deposition of the Late Ordovician glacio-marine units

Comment on "207Pb-206Pb single-zircon evaporation ages of some granitoid rocks reveal continent-oceanic island arc collision during the Cretaceous geodynamic evolution of the Central Anatolian crust, Turkey" - Boztug, D., Tichomirowa, M. & Bombach, K., 2007, JAES 31, 71-86

A continent-oceanic island arc collision model was proposed as a new geodynamic scenario for the evolution of the Cretaceous Central Anatolian granitoids in the Central Anatolian crystalline complex (CACC) by Boztug et al. (2007b) [Boztug, D., Tichomirowa, M., Bombach, K., 2007b. 207Pb-206Pb single-zircon evaporation ages of some granitoid rocks reveal continent-oceanic island arc collision during the Cretaceous geodynamic evolution of the central Anatolian crust, Turkey. journal of Asian Earth Sciences 31, 71-86]. The key aspects of this model include an intra-oceanic subduction in the Neotethyan Izmir-Ankara Ocean, formation of an island arc and its subsequent collision with the northern margin of the Tauride-Anatolide Platform. The identical scenario was initially proposed by Goncuoglu et al. (1992) [Goncuoglu, M.C., Erler, A., Toprak, V., Yaliniz, K., Olgun, E., Rojay, B., 1992. Geology of the western Central Anatolian Massif, Part II: Central Areas. TPAO Report No: 3155, 76 p]. Moreover, the weighted mean values of the reported 207Pb-206Pb single-zircon evaporation ages by Boztug et al. (2007b) [Boztug, D., Tichomirowa, M., Bombach, K., 2007b. 207Pb-206Pb single-zircon evaporation ages of some granitoid rocks reveal continent-oceanic island arc collision during the Cretaceous geodynamic evolution of the central Anatolian crust: Turkey. journal of Asian Earth Sciences 31, 71-86] from A-type granitoids in the CACC seem to be miscalculated and contrast with the field data

Liyas Öncesi Yaşlı Nilüfer Birimi'nin Sakarya Komposit Birliği İçindeki Konumu Ve Jeodinamik Evriminin Petrolojik Olarak Yorumlanması

Önerilen proje ile Sakarya Komposit Birliği'nin (Göncüoğlu v.d. 1997) Liyas öncesi yaşlı temelinde yer alan Nilüfer Birimi'nin (Okay v.d., 1991) jeolojik ve jeokimyasal özellikleri incelerek aynı birlik içerisinde yüzeyleyen diğer birimlerle deneştirilecek ve petrolojik olarak yorumlanacaktır. Dolayısıyla bu proje literatürde Nilüfer Birimi olarak adlandırılan veya eşleniği olarak kabul edilen birimlerin içerisindeki mafik magmatik kökenli kayaçların örneklenmesi ve jeokimyasal analizlerinin yapılması amaçlanmıştır. Bu çalışma ile çok geniş alanlarda yüzeyleyen ve Nilüfer Birimi'ne denk olarak kabul edilen birimlerin gerçekte ne kadar KB Anadolu'da tip lokalitesinde Okay v.d. (1991) tarafından tanımlanan “Nilüfer Birimi” ile eşleştiği ortaya koyulacak ve böylece tektonik oluşum ortamının daha doğru bir şekilde yorumlanması sağlanacaktır

Geochemical characteristics of the basic volcanic rocks within the Karakaya complex: A review Karakaya karmaşigı içerisindeki bazik volkanitlerin jeokimyasal özelliklerinin yeniden deǧerlendirilmesi

Biga Yarımadası’ndan Kuzeydoğu Anadolu’ya kadar uzanan kuşakta Sakarya Tektonik Birliği’nin Liyas öncesi temelinde yer alan Karakaya Karmaşığı değişik türde volkanik kayalar içermektedir. Yaşları, çevre birimlerle ilişkileri ve genel jeokimyasal özellikleri farklı yazarlarca farklı biçimlerde yorumlanan bu volkanik kayalar ile ilgili olarak yayınlanmış ve yayınlanmamış veriler dikkate alınarak bir veri bankası oluşturulmuş ve bu veriler petrolojik olarak yeniden değerlendirilmiştir. Duraylı elementlerin kullanıldığı ayırım diyagramlarında, Karakaya Karmaşığı içerisindeki volkanitler 3 farklı grup oluşturmaktadır. Bunlardan ilki belirgin olarak subalkali alana düşen bazaltlar, diğeri alkalen alana düşen bazaltlar, üçüncü grup ise bu iki grup arasındaki geçişli alana düşen bazik kayalardır. Tektonomagmatik ayırım diyagramlarında Karakaya birimlerine ait bazik volkanik kayalar çoğunlukla levha içi bazalt alanında yer almakta iken, küçük bir kısım ise okyanus ortası sırt ve ada yayı bazaltları ile benzer özellikler sunmaktadır. Çok uzun yıllardır tartışılan Karakaya Karmaşığı jeolojik evriminin aydınlığa kavuşturulabilmesi için bu birim içinde yer alan volkanizmanın, yaşları iyi belirlenmiş bölümlerden başlanarak, nadir toprak elementlerinin ve izotopların kullanıldığı ayrıntılı jeokimyasal veriler esas alınarak araştırılması gerektiği düşünülmektedir

Middle-late Asselian (Early Permian) fusulinid fauna from the post-Variscan cover in NW Anatolia (Turkey): Biostratigraphy and geological implications

The earliest autochthonous cover of the Variscan basement of the Sakarya Composite Terrane (SCT) in NW Anatolia is represented by basal conglomerates and limestones. The microfacies types of the limestones in ascending order are: (1) bioelastic grainstone/packstone, (2) fusulinid grainstone/packstone, (3) smaller foraminiferal grainstone/packstone, (4) Anthracoporella (dasycladale) grainstone/packstone. and (5) wackestones. Twenty-three species assignable to 15 genera of fusulinids were recovered from the studied materials of the Kadirler section; Quasifusulina guvenci nov. sp. and Pseudoschwagerina beedei; magna nov. subsp. are created. Rugosofusulinids, sphaeroschwagerinids, pseudoschwagerinids, occidentoschwagerinids, pseudochusenellids, quasifusulinids, rugosochusenellids and paraschwagerinids are the main faunal elements of the succession, which shows two distinct faunal intervals. Eoschubertella, Schubertella, Biwaella?, Rugosofusulina stabilis group, and Pseudochusenella correspond to the first interval at the base; the second interval is characterized by the species of Sphaeroschwagerina, Pseudoschwagerina, Occidentoschwagerina, the Rugosafusulina latispiralis group, and diverse quasifusulinids. A biostratigraphic correlation shows that the Kadirler section in the SCT in NW Anatolia shares many common species with Central Asia in the East but especially with the Carnic Alps and Karavanke Mountains in the West. The new data suggest that the close faunal relationship in the Late Carboniferous between eastern Alps, Ural Mountains, NW Turkey and Central Asia also continued during the Asselian. (C) 2010 Elsevier Masson SAS. All rights reserved

Geology of the Idis Dagı Avanos area Nevşehir Central Anatolia

İdiş Dağı-Avanos area is located on the northeast of Nevşehir, and is a part of the Central Anatolian Crystalline Complex. The basement rocks of the study area constitue? Mesozoic aged Aşıgediği Metamorphics, that represent the uppermost unit of the Central Anatolian Metamorphics and consist of platform type meta-carbonates. İdiş Dağı Syenitoid, composed of quartz syenite, alkali feldspar quartz syenite and quartz monzonite intruded the Aşıgediği Metamorphics, and generated contact metamorphic zones. Karahıdır Volcanics are found as dykes cutting the İdiş Dağı Syenitoids and as blocks in the Göynük Volcaniclastic Olistostrome. Göynük Volcaniclastic Olistostrome unconformably covers the basement rocks. It is formed within a fault-controlled extansional basin in Uppermost Cretaceous-Lower Paleocene period, and includes the olistoliths of the Karahıdır Volcanics and İdiş Dağı Syenitoids. The late Lower Paleocene-Upper Paleocene Yeşilöz Formation consists of the Saytepe Conglomerate Member and the Asaftepe Member and represents the terrestrial and lacustrine depositional environment. Middle Eocene Mucur Formation characterising shallow marine (reefal) deposition transgressively overlies the basement rocks. It is suggested that in the Early Miocene, a compressional system effected the İdiş Dağı Area, and the basement rocks were thrusted over the Tertiary cover units. The neotectonic period started in Late Miocene in the study area. In this period a new tensional system became effective, Ürgüp and Asarcık Formations are deposited within the basins which are controlled by the Central Kızılırmak Fault Zone. The Quaternary aged travertine occurrences and talus deposits are also related to this fault zone. The Karata

Origin of analcime in the Neogene Arikli Tuff, Biga Peninsula, NW Turkey

The Arikli Tuff in the Behram Volcanics, NW Anatolia, is characterized by its dominance of authigenic analcime. It was studied by optical microscopy, XRD, SEM/EDX, and ICP for a better understanding of the analcime formation, which occurs as coarse-grained euhedral to subhedral crystals in pores and pumice fragments as well as in clusters or fine-grained single crystals embedded in the matrix. Besides analcime, K-feldspar, dolomite, and smectite are found as further authigenic minerals. Based on the dominance of these authigenic minerals, the tuffs are petrographically separated into phyllosilicate-bearing vitric tuff, dolomite-rich vitric tuff, and K-feldspar-dominated vitric tuff. No precursor of zeolites other than analcime was detected. Petrographical and SEM investigations indicate that euhedral to subhedral analcime crystals found as a coarse-grained filling cement in voids and pumice fragments are precipitated from pore water, whereas fine-grained disseminated crystals are formed by the dissolution-precipitation of glassy material. Hydrolysis of glassy material that is similar in composition to analcime provides the additional Na, Al, Si, and K elements which arc necessary for the formation of analcime

TECTONIC CONTROL ON THE DEVELOPMENT OF THE NEOGENE QUATERNARY CENTRAL ANATOLIAN VOLCANIC PROVINCE, TURKEY

The Neogene-Quaternary Central Anatolian Volcanic Province (CAVP) is elongated in a north-east south-west direction within pre-Oligocene basement in central Turkey. This study investigates the field evidence relating to the development of the CAVP