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Öğe Biga Yarımadası'nda (KB Anadolu) Neojen Öncesi Tektonik Birlikler ve Bölgenin Jeodinamik Evrimine Yeni Bir Bakış(2014) Yiğitbaş, Erdinç; Bozkurt, Erdin; Candan, Osman; Lınnemann, Ulf; Şengün, FıratBu projede Biga Yarımadası?nda birbirinden farklı alanlarda mostra veren ve bazılarının çok farklı tektonik kökende olduğu kabul edilmiş olan metamorfik kayalar ile bunlar arasında yer aldığı düşünülen okyanusal alan(lar)ın varlığının test edilmesi amaçlanmıştır. Bu amaçla bölgede daha önce yapılmış araştırmalar da dikkate alınarak kritik alanlar haritalanmış, metamorfik birimlerin petrolojik ve jeokronolojik incelemeleri yapılmıştır. Elde edilen sonuçlar şöyle özetlenebilir; Biga Yarımadası?nda Senozoyik yaşlı volkanik ? çökel örtü altında değişik alanlarda ve birbirinden kopuk mostralar halinde metamorfik kayalar yüzeylenir. Bu kayalar güneyde Kazdağ antiformu boyunca; kuzeyde ise Karadağ, Çamlıca ve Kemer/Karabiga masiflerinde mostralar verirler. Birbirinden kopuk bu mostraların aslında bir bütünün parçaları olduğunun anlaşılması bu projenin belki de en temel ve en önemli sonuçlarından birini oluşturmaktadır. Nitekim bu metamorfik topluluklar birbirleriyle doğrudan dokanakta olan ve tek bir tektonostratigrafik kesitte tanımlanabilen bir tektonostratigrafik istif oluştururlar. Anılan metamorfik mostralardan en güneyde Kazdağında mostra verenler (Kazdağ Grubu) altta Triyas yaşlı, üstte ise Karbonifer yaşlı iki metamorfik topluluk ile bunlar arasında tektonik dokanakla yer alan bir metaofiyolitten oluşur. Kuzeyde Karadağ, Çamlıca ve Kemer/Karabiga masiflerinde mostra veren metamorfik kayalar (Geyikli, Çamlıca, Kemer metamorfitleri) ise birbirlerinden kopuk mostralara sahip olmakla birlikte aslında birbirleriyle korele edilebilen Geç Ediyakaran-Erken Paleozoyik yaşlı bir istifle temsil edilmektedir. Bu istif altta bir metavolkanik- volkaniklastik ve üstte ise başlıca metapelitik bir birimle temsil edilmektedir. Bu metamorfik kayalar yer yer eklojit fasiyesinde metamorfizmaya uğramış metaofiyolitlerle tektonik olarak dilimlenmiştir. Bu metaofiyolitlerin yaşı da Ediyakaran-Erken Paleozoyik?tir. Bu metamorfik temelin üzerinde açısal diskordansla Permiyen yaşlı bir karbonat platformu gelişmiştir. Kuzey metamorfik topluluk güneyde Kalabak Grubu olarak bilinen metamorfik topluluğun eşdeğeridir. Kalabak Grubu da altta bir metavolkanik-volkaniklastik birim ve bunları kesen Erken Devoniyen yaşlı bir metagranitoyid ile temsil edilir. Kalabak Grubu Kazdağ metamorfik kayaları üzerinde tektonik dokanakla doğrudan oturmaktadır. Kalabak Grubunun yaşı da Ediyakaran-Erken Paleozoyik?tir. Metaofiyolitik kayalarla tektonik olarak dilimlenmiştir. Triyas yaşlı Karakaya Grubu kayaları Permiyen karbonat platformunun parçalanmasıyla gelişimine başlayarak Triyas sonunda kapanan kısa ömürlü bir havzadır. Bu havzaya ait birimlerden kenar ve başlangıç fasiyesleri metamorfik temel kayaları üzerinde diskordan olarak oturmaktadır. Bu metamorfik temel kayaları güneyde Liyas yaşlı ve kuzeyde Alt Kretase yaşlı çökellerle açısal diskordansla örtülmektedir.Öğe P-T-t evolution of eclogite/blueschist facies metamorphism in Alanya Massif: time and space relations with HP event in Bitlis Massif, Turkey(Springer, 2016) Cetinkaplan, Mete; Pourteau, Amaury; Candan, Osman; Koralay, O. Ersin; Oberhaensli, Roland; Okay, Aral I.; Chen, FukunThe Alanya Massif, which is located to the south of central Taurides in Turkey, presents a typical nappe pile consisting of thrust sheets with contrasting metamorphic histories. In two thrust sheets, Sugozu and GundogmuAY nappes, HP metamorphism under eclogite (550-567 A degrees C/14-18 kbar) and blueschist facies (435-480 A degrees C/11-13 kbar) conditions have been recognized, respectively. Whereas the rest of the Massif underwent MP metamorphism under greenschist to amphibolite facies (525-555 A degrees C/6.5-7.5 kbar) conditions. Eclogite facies metamorphism in Sugozu nappe, which consists of homogeneous garnet-glaucophane-phengite schists with eclogite lenses is dated at 84.8 +/- A 0.8, 84.7 +/- A 1.5 and 82 +/- A 3 Ma (Santonian-Campanian) by 40Ar/39Ar phengite, U/Pb zircon and rutile dating methods, respectively. Similarly, phengites in GundogmuAY nappe representing an accretionary complex yield 82-80 Ma (Campanian) ages for blueschist facies metamorphism. During the exhumation, the retrograde overprint of the HP units under greenschist-amphibolite facies conditions and tectonic juxtaposition with the Barrovian units occurred during Campanian (75-78 Ma). Petrological and geochronological data clearly indicate a similar Late Cretaceous tectonometamorphic evolution for both Alanya (84-75 Ma) and Bitlis (84-72 Ma) Massifs. They form part of a single continental sliver (Alanya-Bitlis microcontinent), which was rifted from the southern part of the Anatolide-Tauride platform. The P-T-t coherence between two Massifs suggests that both Massifs have been derived from the closure of the same ocean (Alanya-Bitlis Ocean) located to the south of the Anatolide-Tauride block by a northward subduction. The boundary separating the autochthonous Tauride platform to the north from both the Alanya and Bitlis Massifs to the south represents a suture zone, the Pamphylian-Alanya-Bitlis suture.Öğe Petrography and geochemistry of paragneisses in the Cine submassif of the Menderes Massif, western Anatolia(Tubitak Scientific & Technological Research Council Turkey, 2006) Senguen, Firat; Candan, Osman; Dora, O. Oezcan; Koralay, O. ErsinThe Menderes Massif, which covers a large area in western Turkey, is made up of Pan-African basement rocks and a Palaeozoic to Early Tertiary cover sequence. The study area is located in the Dalama and Hallaclar (Aydin) area, in the northern and central parts of the Cine submassif of the Menderes Massif. The oldest units of the Pan-African basement are metaclastics, consisting of paragneisses and mica schists that gradually and conformably overlay paragneisses. Macroscopic appearances and mineralogical and textural data indicate that paragneisses can be subdivided into four subgroups. These are: ( 1) black spotted, ( 2) white spotted, ( 3) massive, grey-coloured and ( 4) massive, purple-coloured paragneisses. Geochemical data show that the spotted and purple-coloured paragneisses are characterized by high alumina content that is consistent with high sillimanite content. Paragneisses exposed in the eastern part of the Cine submassif were partly migmatized during the last stage of the polyphase Pan-African metamorphism. Based on comparison with relics of upper amphibolite to granulite (?) facies parageneses in the Pan-African basement of the Menderes Massif, we infer that the porphyroblasts in the black-spotted paragneisses are pseudomorphs after cordierite. Considering the inferred replacement of cordierite by sillimanite + garnet + biotite, it can be concluded that former high-temperature assemblages were overprinted by almandine-amphibolite facies metamorphism. Geochemical data obtained from paragneisses and mica schists reveal that the protoliths of this metaclastic sequence were derived from a cratonic provenance. The paragneisses are intruded by 550 Ma syn- to post-orogenic orthogneisses. Based on the well-preserved the original intrusive contact relationship with the orthogneisses and the youngest detrital zircon ages in paragneisses, it can be inferred that the time of deposition of their protolith is Late Proterozoic.Öğe Petrography and geochemistry of paragneisses in the Çine submassif of the Menderes Massif, Western Anatolia(2006) Şengün, Firat; Candan, Osman; Dora, O. Özcan; Koralay, ErsinThe Menderes Massif, which covers a large area in western Turkey, is made up of Pan-African basement rocks and a Palaeozoic to Early Tertiary cover sequence. The study area is located in the Dalama and Hallaçlar (Aydin) area, in the northern and central parts of the Çine submassif of the Menderes Massif. The oldest units of the Pan-African basement are metaclastics, consisting of paragneisses and mica schists that gradually and conformably overlay paragneisses. Macroscopic appearances and mineralogical and textural data indicate that paragneisses can be subdivided into four subgroups. These are: (1) black spotted, (2) white spotted, (3) massive, grey-coloured and (4) massive, purple-coloured paragneisses. Geochemical data show that the spotted and purple-coloured paragneisses are characterized by high alumina content that is consistent with high sillimanite content. Paragneisses exposed in the eastern part of the Çine submassif were partly migmatized during the last stage of the polyphase Pan-African metamorphism. Based on comparison with relics of upper amphibolite to granulite (?) facies parageneses in the Pan-African basement of the Menderes Massif, we infer that the porphyroblasts in the black-spotted paragneisses are pseudomorphs after cordierite. Considering the inferred replacement of cordierite by sillimanite + garnet + biotite, it can be concluded that former high-temperature assemblages were overprinted by almandine-amphibolite facies metamorphism. Geochemical data obtained from paragneisses and mica schists reveal that the protoliths of this metaclastic sequence were derived from a cratonic provenance. The paragneisses are intruded by 550 Ma syn- to post-orogenic orthogneisses. Based on the well-preserved the original intrusive contact relationship with the orthogneisses and the youngest detrital zircon ages in paragneisses, it can be inferred that the time of deposition of their protolith is Late Proterozoic. Copyright © TÜBİTAK.
