TY - JOUR A1 - Ambarli, Hüseyin A1 - Mengüllüoğlu, Deniz A1 - Fickel, Jörns A1 - Förster, Daniel W. T1 - Hotel AMANO Grand Central of brown bears in southwest Asia JF - PeerJ N2 - Genetic studies of the Eurasian brown bear (Ursus arctos) have so far focused on populations from Europe and North America, although the largest distribution area of brown bears is in Asia. In this study, we reveal population genetic parameters for the brown bear population inhabiting the Grand Kackar Mountains (GKM) in the north east of Turkey, western Lesser Caucasus. Using both hair (N = 147) and tissue samples (N = 7) collected between 2008 and 2014, we found substantial levels of genetic variation (10 microsatellite loci). Bear samples (hair) taken from rubbing trees worked better for genotyping than those from power poles, regardless of the year collected. Genotyping also revealed that bears moved between habitat patches, despite ongoing massive habitat alterations and the creation of large water reservoirs. This population has the potential to serve as a genetic reserve for future reintroduction in the Middle East. Due to the importance of the GKM population for on-going and future conservation actions, the impacts of habitat alterations in the region ought to be minimized; e.g., by establishing green bridges or corridors over reservoirs and major roads to maintain habitat connectivity and gene flow among populations in the Lesser Caucasus. KW - Ursus arctos KW - Microsatellite KW - Conservation KW - Anatolia KW - Isolation KW - Source population KW - Noninvasive sampling KW - Rubbing tree KW - Turkey Y1 - 2018 U6 - https://doi.org/10.7717/peerj.5660 SN - 2167-8359 VL - 6 PB - PeerJ Inc. CY - London ER - TY - JOUR A1 - Mueller, Megan A. A1 - Licht, Alexis A1 - Campbell, C. A1 - Ocakoglu, F. A1 - Taylor, Marc Hollis A1 - Burch, L. A1 - Ugrai, Tamas A1 - Kaya, M. A1 - Kurtoglu, B. A1 - Coster, P. M. C. A1 - Metais, Mustafa Yücel A1 - Beard, Kenneth Christopher T1 - Collision Chronology Along the Izmir-Ankara-Erzincan Suture Zone: Insights From the Saricakaya Basin, Western Anatolia JF - Tectonics N2 - Debate persists concerning the timing and geodynamics of intercontinental collision, style of syncollisional deformation, and development of topography and fold-and-thrust belts along the >1,700-km-long Izmir-Ankara-Erzincan suture zone (IAESZ) in Turkey. Resolving this debate is a necessary precursor to evaluating the integrity of convergent margin models and kinematic, topographic, and biogeographic reconstructions of the Mediterranean domain. Geodynamic models argue either for a synchronous or diachronous collision during either the Late Cretaceous and/or Eocene, followed by Eocene slab breakoff and postcollisional magmatism. We investigate the collision chronology in western Anatolia as recorded in the sedimentary archives of the 90-km-long Saricakaya Basin perched at shallow structural levels along the IAESZ. Based on new zircon U-Pb geochronology and depositional environment and sedimentary provenance results, we demonstrate that the Saricakaya Basin is an Eocene sedimentary basin with sediment sourced from both the IAESZ and Sogut Thrust fault to the south and north, respectively, and formed primarily by flexural loading from north-south shortening along the syncollisional Sogut Thrust. Our results refine the timing of collision between the Anatolides and Pontide terranes in western Anatolia to Maastrichtian-Middle Paleocene and Early Eocene crustal shortening and basin formation. Furthermore, we demonstrate contemporaneous collision, deformation, and magmatism across the IAESZ, supporting synchronous collision models. We show that regional postcollisional magmatism can be explained by renewed underthrusting instead of slab breakoff. This new IAESZ chronology provides additional constraints for kinematic, geodynamic, and biogeographic reconstructions of the Mediterranean domain. KW - Anatolia KW - geochronology KW - collision KW - Eocene KW - detrital zircons Y1 - 2019 U6 - https://doi.org/10.1029/2019TC005683 SN - 0278-7407 SN - 1944-9194 VL - 38 IS - 10 SP - 3652 EP - 3674 PB - American Geophysical Union CY - Washington ER - TY - GEN A1 - Ambarlı, Hüseyin A1 - Mengüllüoğlu, Deniz A1 - Fickel, Jörns A1 - Förster, Daniel W. T1 - Population genetics of the main population of brown bears in southwest Asia T2 - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe N2 - Genetic studies of the Eurasian brown bear (Ursus arctos) have so far focused on populations from Europe and North America, although the largest distribution area of brown bears is in Asia. In this study, we reveal population genetic parameters for the brown bear population inhabiting the Grand Kaçkar Mountains (GKM) in the north east of Turkey, western Lesser Caucasus. Using both hair (N = 147) and tissue samples (N = 7) collected between 2008 and 2014, we found substantial levels of genetic variation (10 microsatellite loci). Bear samples (hair) taken from rubbing trees worked better for genotyping than those from power poles, regardless of the year collected. Genotyping also revealed that bears moved between habitat patches, despite ongoing massive habitat alterations and the creation of large water reservoirs. This population has the potential to serve as a genetic reserve for future reintroductions in the Middle East. Due to the importance of the GKM population for on-going and future conservation actions, the impacts of habitat alterations in the region ought to be minimized; e.g., by establishing green bridges or corridors over reservoirs and major roads to maintain habitat connectivity and gene flow among populations in the Lesser Caucasus. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 937 KW - Ursus arctos KW - microsatellite KW - conservation KW - Anatolia KW - isolation KW - source population KW - noninvasive sampling KW - rubbing tree KW - Turkey Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-459124 SN - 1866-8372 IS - 937 ER - TY - JOUR A1 - Licht, Alexis A1 - Coster, P. A1 - Ocakoglu, F. A1 - Campbell, C. A1 - Metais, G. A1 - Mulch, Andreas A1 - Taylor, M. A1 - Kappelman, John A1 - Beard, K. Christopher T1 - Tectono-stratigraphy of the Orhaniye Basin, Turkey: Implications for collision chronology and Paleogene biogeography of central Anatolia JF - Journal of Asian earth sciences N2 - Located along the Izmir-Ankara-Erzincan Suture (IAES), the Maastrichtian - Paleogene Orhaniye Basin has yielded a highly enigmatic-yet poorly dated- Paleogene mammal fauna, the endemic character of which has suggested high faunal provincialism associated with paleogeographic isolation of the Anatolian landmass during the early Cenozoic. Despite its biogeographic significance, the tectono-stratigraphic history of the Orhaniye Basin has been poorly documented; Here, we combine sedimentary, magnetostratigraphic, and geochronological data to infer the chronology and depositional history of the Orhaniye Basin. We then assess how our new data and interpretations for the Orhaniye Basin impact (1) the timing and mechanisms of seaway closure along the IAES and (2) the biogeographic evolution of Anatolia. Our results show that the Orhaniye Basin initially developed as a forearc basin during the Maastrichtian, before shifting to a retroarc foreland basin setting sometime between the early Paleocene and 44 Ma. This chronology supports a two-step scenario for the assemblage of the central Anatolian landmass, with incipient collision during the Paleocene - Early Eocene and final seaway retreat along the IAES during the earliest Late Eocene after the last marine incursion into the foreland basin. Our dating for the Orhaniye mammal fauna (44-43 Ma) indicates the persistence of faunal endemism in northern Anatolia until at least the late Lutetian despite the advanced stage of IAES closure. The tectonic evolution of dispersal corridors linking northern Anatolia with adjacent parts of Eurasia was not directly associated with IAES closure and consecutive uplifts, but rather with the build-up of continental bridges on the margins of Anatolia, in the Alpine and Tibetan-Himalayan orogens. KW - Anatolia KW - Eocene KW - Collision KW - Biogeography Y1 - 2017 U6 - https://doi.org/10.1016/j.jseaes.2017.03.033 SN - 1367-9120 SN - 1878-5786 VL - 143 SP - 45 EP - 58 PB - Elsevier CY - Oxford ER - TY - JOUR A1 - Scheffler, Franziska A1 - Oberhänsli, Roland A1 - Pourteau, Amaury A1 - Immenhauser, A. A1 - Candan, O. T1 - Sedimentologic to metamorphic processes recorded in the high-pressure/low-temperature Mesozoic Rosetta Marble of Anatolia JF - International journal of earth sciences N2 - Anatolia’s high-pressure metamorphic belts are characterized in part by a Neotethyan stratigraphic succession that includes a mid-Cretaceous hemi-pelagic marble sequence. This unit contains, towards its stratigraphic top, dm-to-m-long radiating calcitic rods forming rosette-like textures. Here, we refer to these features as “Rosetta Marble”. The remarkable textural similarity of non-metamorphic selenite crystals and radiating calcite rods in the Rosetta Marble strongly suggests that these textures represent pseudomorphs after selenites. Metamorphosed hemi-pelagic limestones, dominated by Rosetta selenite pseudomorphs, are alternating with siliceous meta-sediments containing relictic radiolaria tests. This stratigraphic pattern is indicative of transient phases characterized by evaporites precipitated from basinal brines alternating with non-evaporative hemi-pelagic deposition from normal-marine seawater. The regional distribution of Rosetta Marble exposures over 600 km is indicative of basin-scale evaporitic intervals. High-pressure, low-temperature metamorphism of these rocks is witnessed by Sr-rich (up to 3500 ppm), fibrous calcite pseudomorphs after aragonite and isolated aragonite inclusions in quartz. Peak metamorphic conditions of 1.2 GPa and 300–350 °C are attested by high-Si white mica thermobarometry. The Rosetta Marble case example examines the potential to unravel the complete history from deposition to diagenesis and metamorphism of meta-sedimentary rocks. KW - Gypsum KW - High-pressure metamorphism KW - Neotethys KW - Anatolia Y1 - 2016 U6 - https://doi.org/10.1007/s00531-015-1214-y SN - 1437-3254 SN - 1437-3262 VL - 105 SP - 225 EP - 246 PB - Springer CY - New York ER - TY - JOUR A1 - Pourteau, Amaury A1 - Oberhänsli, Roland A1 - Candan, Osman A1 - Barrier, Eric A1 - Vrielynck, Bruno T1 - Neotethyan closure history of western Anatolia: a geodynamic discussion JF - International journal of earth sciences N2 - This paper addresses the lithosphere-scale subduction-collision history of the eastern termination of the Aegean retreating subduction system, i.e. western Anatolia. Although there is some general consensus on the protracted subduction evolution of the Aegean since the early Cenozoic at least, correlation with western Anatolia has been widely debated for more than several decades. In western Anatolia, three main tectonic configurations have been envisaged in the past years to reconstruct slab dynamics during the closure of the Neotethyan oceanic realm since the Late Cretaceous. Some authors have suggested an Aegean-type scenario, with the continuous subduction of a single lithospheric slab, punctuated by episodic slab roll-back and trench retreat, whereas others assumed a discontinuous subduction history marked by intermittent slab break-off during either the Campanian (ca. 75 Ma) or the Early Eocene (ca. 55-50 Ma). The third view implies three partly contemporaneous subduction zones. Our review of these models points to key debated aspects that can be re-evaluated in the light of multidisciplinary constraints from the literature. Our discussion leads us to address the timing of subduction initiation, the existence of hypothetical ocean basins, the number of intervening subduction zones between the Taurides and the Pontides, the palaeogeographic origin of tectonic units and the possibility for slab break-off during either the Campanian or the Early Eocene. Thence, we put forward a favoured tectonic scenario featuring two successive phases of subduction of a single lithospheric slab and episodic accretion of two continental domains separated by a continental trough, representing the eastern end of the Cycladic Ocean of the Aegean. The lack of univocal evidence for slab break-off in western Anatolia and southward-younging HP/LT metamorphism in continental tectonic units (from similar to 85, 70 to 50 Ma) in the Late Cretaceous-Palaeogene period suggests continuous subduction since similar to 110 Ma, marked by roll-back episodes in the Palaeocene and the Oligo-Miocene, and slab tearing below western Anatolia during the Miocene. KW - Subduction KW - Anatolia KW - Aegean KW - Neotethys KW - Slab break-off KW - Slab roll-back Y1 - 2016 U6 - https://doi.org/10.1007/s00531-015-1226-7 SN - 1437-3254 SN - 1437-3262 VL - 105 SP - 203 EP - 224 PB - Springer CY - New York ER - TY - JOUR A1 - Pourteau, Amaury A1 - Sudo, Masafumi A1 - Candan, Osman A1 - Lanari, P. A1 - Vidal, O. A1 - Oberhänsli, Roland T1 - Neotethys closure history of Anatolia - insights from Ar-40-Ar-39 geochronology and P-T estimation in high-pressure metasedimentary rocks JF - Journal of metamorphic geology N2 - The multiple high-pressure (HP), low-temperature (LT) metamorphic units of Western and Central Anatolia offer a great opportunity to investigate the subduction-and continental accretion-related evolution of the eastern limb of the long-lived Aegean subduction system. Recent reports of the HP-LT index mineral Fe-Mg-carpholite in three metasedimentary units of the Gondwana-derived Anatolide-Tauride continental block (namely the Afyon Zone, the Oren Unit and the southern Menderes Massif) suggest a more complicated scenario than the single-continental accretion model generally put forward in previous studies. This study presents the first isotopic dates (white mica Ar-40-Ar-39 geochronology), and where possible are combined with P-T estimates (chlorite thermometry, phengite barometry, multi-equilibrium thermobarometry), on carpholite-bearing rocks from these three HP-LT metasedimentary units. It is shown that, in the Afyon Zone, carpholite-bearing assemblages were retrogressed through greenschist-facies conditions at c. 67-62 Ma. Early retrograde stages in the Oren Unit are dated to 63-59 Ma. In the Kurudere-Nebiler Unit (HP Mesozoic cover of the southern Menderes Massif), HP retrograde stages are dated to c. 45 Ma, and post-collisional cooling to c. 26 Ma. These new results support that the Oren Unit represents the westernmost continuation of the Afyon Zone, whereas the Kurudere-Nebiler Unit correlates with the Cycladic Blueschist Unit of the Aegean Domain. In Western Anatolia, three successive HP-LT metamorphic belts thus formed: the northernmost Tavsanli Zone (c. 88-82 Ma), the Oren-Afyon Zone (between 70 and 65 Ma), and the Kurudere-Nebiler Unit (c. 52-45 Ma). The southward younging trend of the HP-LT metamorphism from the upper and internal to the deeper and more external structural units, as in the Aegean Domain, points to the persistence of subduction in Western Anatolia between 93-90 and c. 35 Ma. After the accretion of the Menderes-Tauride terrane, in Eocene times, subduction stopped, leading to continental collision and associated Barrovian-type metamorphism. Because, by contrast, the Aegean subduction did remain active due to slab roll-back and trench migration, the eastern limb (below Southwestern Anatolia) of the Hellenic slab was dramatically curved and consequently teared. It therefore is suggested that the possibility for subduction to continue after the accretion of buoyant (e.g. continental) terranes probably depends much on palaeogeography. KW - Ar-40-Ar-39 geochronology KW - Anatolia KW - chlorite-phengite thermobarometry KW - high-pressure metasedimentary rocks Y1 - 2013 U6 - https://doi.org/10.1111/jmg.12034 SN - 0263-4929 SN - 1525-1314 VL - 31 IS - 6 SP - 585 EP - 606 PB - Wiley-Blackwell CY - Hoboken ER - TY - THES A1 - Pourteau, Amaury T1 - Closure of the Neotethys Ocean in Anatolia : structural, petrologic and geochronologic insights from low-grade high-pressure metasediments, Afyon Zone T1 - Die Schließung des Neotethyschen-Ozeans in Anatolien : strukturelle, petrologische und geochronologische Erkenntnisse von niedriggradigen hochdruckmetamorphen Sedimenten, Afyon-Zone (Türkei) N2 - The complete consumption of the oceanic domain of a tectonic plate by subduction into the upper mantle results in continent subduction, although continental crust is typically of lower density than the upper mantle. Thus, the sites of former oceanic domains (named suture zones) are generally decorated with stratigraphic sequences deposited along continental passive margins that were metamorphosed under low-grade, high-pressure conditions, i.e., low temperature/depth ratios (< 15°C/km) with respect to geothermal gradients in tectonically stable regions. Throughout the Mesozoic and Cenozoic (i.e., since ca. 250 Ma), the Mediterranean realm was shaped by the closure of the Tethyan Ocean, which likely consisted in numerous oceanic domains and microcontinents. However, the exact number and position of Tethyan oceans and continents (i.e., the Tethyan palaeogeography) remains debated. This is particularly the case of Western and Central Anatolia, where a continental fragment was accreted to the southern composite margin of the Eurasia sometime between the Late Cretaceous and the early Cenozoic. The most frontal part of this microcontinent experienced subduction-related metamorphism around 85-80 Ma, and collision-related metamorphism affected more external parts around 35 Ma. This unsually-long period between subduction- and collision-related metamorphisms (ca. 50 Ma) in units ascribed to the same continental edge constitutes a crucial issue to address in order to unravel how Anatolia was assembled. The Afyon Zone is a tectono-sedimentary unit exposed south and structurally below the front high-pressure belt. It is composed of a Mesozoic sedimentary sequence deposited on top of a Precambrian to Palaeozoic continental substratum, which can be traced from Northwestern to southern Central Anatolia, along a possible Tethyan suture. Whereas the Afyon Zone was defined as a low-pressure metamorphic unit, high-pressure minerals (mainly Fe-Mg-carpholite in metasediments) were recently reported from its central part. These findings shattered previous conceptions on the tectono-metamorphic evolution of the Afyon Zone in particular, and of the entire region in general, and shed light on the necessity to revise the regional extent of subduction-related metamorphism by re-inspecting the petrology of poorly-studied metasediments. In this purpose, I re-evaluated the metamorphic evolution of the entire Afyon Zone starting from field observations. Low-grade, high-pressure mineral assemblages (Fe-Mg-carpholite and glaucophane) are reported throughout the unit. Well-preserved carpholite-chloritoid assemblages are useful to improve our understanding of mineral relations and transitions in the FeO-MgO-Al2O3-SiO2-H2O system during rocks’ travel down to depth (prograde metamorphism). Inspection of petrographic textures, minute variations in mineral composition and Mg-Fe distribution among carpholite-chloritoid assemblages documents multistage mineral growth, accompanied by a progressive enrichment in Mg, and strong element partitioning. Using an updated database of mineral thermodynamic properties, I modelled the pressure and temperature conditions that are consistent with textural and chemical observations. Carpholite-bearing assemblages in the Afyon Zone account for a temperature increase from 280 to 380°C between 0.9 and 1.1 GPa (equivalent to a depth of 30-35 km). In order to further constrain regional geodynamics, first radiometric ages were determined in close association with pressure-temperature estimates for the Afyon Zone, as well as two other tectono-sedimentary units from the same continental passive margin (the Ören and Kurudere-Nebiler Units from SW Anatolia). For age determination, I employed 40Ar-39Ar geochronology on white mica in carpholite-bearing rocks. For thermobarometry, a multi-equilibrium approach was used based on quartz-chlorite-mica and quartz-chlorite-chloritoid associations formed at the expense of carpholite-bearing assemblages, i.e., during the exhumation from the subduction zone. This combination allows deciphering the significance of the calculated radiometric ages in terms of metamorphic conditions. Results show that the Afyon Zone and the Ören Unit represent a latest Cretaceous high-pressure metamorphic belt, and the Kurudere-Nebiler Unit was affected by subduction-related metamorphism around 45 Ma and cooled down after collision-related metamorphism around 26 Ma. The results provided in the present thesis and from the literature allow better understanding continental amalgamation in Western Anatolia. It is shown that at least two distinct oceanic branches, whereas only one was previously considered, have closed during continuous north-dipping subduction between 92 and 45 Ma. Between 85-80 and 70-65 Ma, a narrow continental domain (including the Afyon Zone) was buried into a subduction zone within the northern oceanic strand. Parts of the subducted continent crust were exhumed while the upper oceanic plate was transported southwards. Subduction of underlying lithosphere persisted, leading to the closure of the southern oceanic branch and to subduct the front of a second continental domain (including the Kurudere-Nebiler Unit). This followed by a continental collisional stage characterized by the cease of subduction, crustal thicknening and the detachment of the subducting oceanic slab from the accreted continent lithosphere. The present study supports that in the late Mesozoic the East Mediterranean realm had a complex tectonic configuration similar to present Southeast Asia or the Caribbean, with multiple, coexisting oceanic basins, microcontinents and subduction zones. N2 - Kontinentale Subduktion resultiert aus dem Abtauchen des ozenanischen Gebiets einer tektonischen Platte in den Oberen Erdmantel. Dies geschieht obwohl die kontinentale Erdkruste normalerweise eine geringere Dichte besitzt als der Obere Erdmantel. Die Lage ehemaliger ozeanischer Gebiete (auch als Suturzonen bezeichnet) ist dementsprechend durch stratigraphische, sedimentäre Gesteinsabfolgen gekennzeichnet, die entlang des passiven Kontinentalrandes abgelagert wurden. Anschließend wurden diese Gesteine unter niedrigen Temperaturen und hohem Druck umgewandelt, auch niedrig-gradige Hochdruckmetamorphose genannt. Während der gesamten Zeitspanne des Mesozoikums und Känozoikums (seit etwa 250 Millionen Jahren bis heute) wurde der mediterrane Raum durch die kontinuierliche Schließung des Tethyschen Ozeans (dem heutigen Mittelmeer) geprägt, der vermutlich in zahlreichen kleineren Ozeanen und Mikrokontinenten aufgeteilt war. Dennoch bleiben die genaue Anzahl und Lage der tethyschen Ozeane und Kontinente (die Paläogeographie der Tethys) bis heute umstritten. Das ist insbesondere der Fall in West- und Zentral-Anatolien, wo im Zeitraum zwischen der Oberen Kreide (vor 98 bis 65 Mio. J.) und dem unteren Känozoikum (vor 65 bis 40 Mio. J.) ein kontinentales Fragment am südlichen Kontinentalrand der Eurasischen Platte angelagert wurde (auch als Akkretion bezeichnet). Der vorderste Bereich von diesem Fragment erfuhr vor etwa 85-80 Millionen Jahren eine metamorphe Umwandlung, die mit den Prozessen der fortschreitenden Subduktion assoziiert werden können. Hingegen wurden die hinteren Bereiche erst später vor ca. 40-30 Mio. J. durch die Kollison der zwei Platten metamorph überprägt. Die ungewöhnlich lange Zeitspanne von etwa 40-50 Mio. J. zwischen den metamorphen Prozessen der Subduktion und der Kollision, stellt eine entscheidende Frage zum Verständnis der Entstehung von Anatolien dar. Die Afyon Zone repräsentiert hierbei eine tektonisch-beanspruchte sedimentäre Gesteinseinheit, die in einer strukturell tieferen Position bezüglich des frontalen metamorphen Hochdruckgürtels liegt und südlich von ihm anzutreffen ist. Die Afyon Zone besteht aus mesozoischen sedimentären Einheiten (250 bis 65 Mio. J. alt), die auf präkambrischem (älter als 545 Mio. J.) bis paläozoischem Untergrund (bis vor 250 Mio J.) abgelagert wurden, und vom nordwestlichen bis zentralen Anatolien, entlang der vermutlichen Tethys-Suturzone, verfolgt werden können. Obwohl die Afyon-Zone als eine niedrig-temperierte metamorphe Gesteinseinheit bezeichnet wird, wurde in letzter Zeit von Vorkommen von Hochdruckmineralen (v.a. Eisen(Fe)-Magnesium(Mg)-Karpholith in metamorphen Sedimenten) im zentralen Bereich berichtet. Diese neuen Erkenntnisse stellen die bisherigen Interpretationen zur tektonisch-metamorphen Entstehung der gesamten Region in Frage, insbesondere der der Afyon-Zone. Deshalb war eine erneute gründliche Überarbeitung und Untersuchung der wenig studierten metamorph-überprägten Sedimentgesteine in diesem Gebiet notwendig. Deshalb, überarbeitete ich die metamorphe Entwicklung der gesamten Afyon Zone, beginnend mit intensiver Geländearbeit und -beobachtungen. Mineralvergesellschaftungen aus Karpholith und Glaukophan, die unter niedrigen Temperaturen und hohem Druck entstanden sind, wurden in der gesamten Gesteinseinheit gefunden. Guterhaltene Mineralvergesellschaftungen aus Karpholith und Chloritoid sind nützlich für das Verständnis unter welchen Temperatur- und Druck-Bedingungen die Gesteine in die Tiefe gelangen (prograde Metamorphose). Durch die Untersuchungen von Gesteinsgefügen und der Eisen-Magnesium-Verteilung zwischen den Mineralien Karpholith und Chloritoid lassen sich Aussagen zu der Bildungstemperatur und dem Druck dieser Minerale machen. Dafür benutzte ich eine verbesserte Datenbank mit Mineraleigenschaften, die mir die Modellierung von Temperatur und Druck erlaubte und im Einklang mit den chemischen und mikroskopischen Beobachtungen steht. Es ergab sich, dass die Karpholith-haltigen Gesteine in der Afyon-Zone einen Temperaturanstieg von 280 zu 380°C (bei einer Tiefe von 30-35 km) erfahren haben. Um noch bessere Aussagen über die Entstehung zu treffen, wurden auch radiometrische Datierungen an Proben aus der Afyon-Zone, sowie an zwei weiteren Sedimentgesteinseinheiten (Ören- und Kurudere-Nebiler-Einheit aus SW Anatolien) gemacht. Für die Altersbestimmung benutzte ich die weitverbreitete 40Ar-39Ar Datierungsmethode an Hellglimmer-Mineralien in den Karpholith-haltigen Gesteinen. Temperatur und Druck können auch bestimmt werden, wenn man den Übergang von einer Mineralvergesellschaftung zu einer anderen Vergesellschaftung beobachtet. Dies gilt zum Beispiel für den Übergang von einer Karpholith-haltigen Zusammensetzung zu einer Quartz-Chlorit-Glimmer und Quartz-Chlorit-Chloritoid Mineralvergesellschaftung wenn tief subduzierte Gesteine wieder nach oben gelangen (Exhumation). Damit lassen sich die radiometrischen Alter den metamorphen Prozessen zu bestimmten Temperaturen und Drücken zuordnen. Mit diesen Erkenntnissen lassen sich die Afyon-Zone und die Ören-Einheit einem Hochdruck-Gebirgsgürtel in der späten Kreidezeit zuordnen, während die Kurudere-Nebiler Einheit durch die mit der Subduktion in Verbindung stehende Metamorphose vor ca. 45 Mio. J. beeinflusst wurde. Später wurde diese Einheit durch die Metamorphose, resultierend aus der Kollision vor 26 Mio. J., abgekühlt. Die Ergebnisse dieser und anderer Arbeiten erlauben es die Anlagerung von Kontinenten in West-Anatolien besser zu verstehen. Es wird gezeigt, dass mindestens zwei (im Gegensatz zu vorher einem) voneinander unabhängige Ozeanarme während der Subduktion von 92 bis 45 Millionen Jahren geschlossen wurden. Zwischen 85-80 und 70-65 Millionen Jahren, wurde ein schmales kontinentales Gebiet (welches die Afyon-Zone beinhaltet) in die Subduktionszone hineingzogen. Teile der subduzierten kontientalen Kruste kamen wieder an die Oberfläche (Exhumation), während die obere ozeanische Platte südwärts transportiert wurde. Die anhaltende Subduktion im oberen Bereich des Erdmantels (Lithosphäre) führte zu der Schließung des südlichen Ozeanarms und zu der Subduktion des zweiten kontinentalen Gebietes (welches die Kurudere-Nebiler-Einheit beinhaltete). Darauf folgte die kontinentale Kollisionsphase unter dem Ausklingen der Prozesse der Subduktion, der Krustenverdickung und der Abtrennung der subduzierten ozeanischen Platte von der akkretionierten kontientalen Lithosphäre (auch als Delamination bezeichnet). Die hier präsentierte Arbeit unterstüzt die Annahme das während der Oberen Kreidezeit das Ost-Mediterrane Gebiet tektonsich komplex angeordnet war, vergleichbar mit dem heutigen Südost-Asien oder der Karibik, mit ihren vielen gleichzeitig existierenden ozeanischen Becken, Mikrokontinenten und Subduktionszonen. KW - Anatolien KW - hochdruckmetamorphe Sedimente KW - Karpholithe KW - 40Ar-39Ar Datierungsmethode KW - Anatolia KW - high-pressure metasediments KW - carpholite KW - Ar-Ar geochronology KW - multi-equilibrium thermobarometry Y1 - 2011 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-57803 ER -