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Yayın Quaternary uplift of the northern margin of the Central Anatolian Plateau: New OSL dates of fluvial and delta-terrace deposits of the Kizilirmak River, Black Sea coast, Turkey(Pergamon-Elsevier Science Ltd, 2018-12-01) Berndt, Christopher; Yıldırım, Cengiz; Çiner, Tahsin Attila; Strecker, Manfred R.; Ertunç, Gülgün; Sarıkaya, Mehmet Akif; Özcan, Orkan; Öztürk, Tuğba; Güneç Kıyak, NafiyeWe analysed the interplay between coastal uplift, sea level change in the Black Sea, and incision of the Kizilirmak River in northern Turkey. These processes have created multiple co-genetic fluvial and marine terrace sequences that serve as excellent strain markers to assess the ongoing evolution of the Pontide orogenic wedge and the growth of the northern margin of the Central Anatolian Plateau. We used high-resolution topographic data, OSL ages, and published information on past sea levels to analyse the spatiotemporal evolution of these terraces; we derived a regional uplift model for the northward advancing orogenic wedge that supports the notion of laterally variable uplift rates along the flanks of the Pontides. The best-fit uplift model defines a constant long-term uplift rate of 0.28 +/- 0.07 m/ka for the last 545 ka. This model explains the evolution of the terrace sequence in light of active tectonic processes and superposed cycles of climate-controlled sea-level change. Our new data reveal regional uplift characteristics that are comparable to the inner sectors of the Central Pontides; accordingly, the rate of uplift diminishes with increasing distance from the main strand of the restraining bend of the North Anatolian Fault Zone (NAFZ). This spatial relationship between the regional impact of the restraining bend of the NAFZ and uplift of the Pontide wedge thus suggests a strong link between the activity of the NAFZ, deformation and uplift in the Pontide orogenic wedge, and the sustained lateral growth of the Central Anatolian Plateau flank.Yayın Cement fabrics and optical luminescence ages of beachrock, North Cyprus: Implications for Holocene sea-level changes(Elsevier Ltd., 2016-05-16) Öztürk, Muhammed Zeynel; Erginal, Ahmet Evren; Güneç Kıyak, Nafiye; Öztürk, TuğbaCaCO3-cemented beachrocks are widely found along the northern coast of Cyprus. In this study, we aim to discuss the cementation history of beachrocks at ten particular sites within the context of Holocene sea-level changes. Cement fabrics, petrographic and geochemical characteristics, and optically-stimulated luminescence ages of buried quartz grains were studied. The seaward-inclined (~5-10°) parallel-stratified beds are composed mostly of sandstone alternating with conglomerate. Ooids, benthic and planktic foraminifera, bioclasts of red algae, echinoid spines and gastropods make up a significant proportion of the cemented beds. With CaCO3 content ranging between 37% and 65%, poorly-sorted grains are bonded by four distinct cements: circumgranular micritic coatings, sparry calcite infillings, pore fills, and meniscus bridges. This consecutive nature of cementation is typical of a marine phreatic and meteoric vadose environment when the sea level was lower than present but had a tendency to increase during middle to late Holocene. OSL ages ranging from 5.4 ka to 0.38 ka indicate that the deposition and ensuing cementation of the quartz grains occurred during two main stages; younger beds dated between 2.3 ka and 0.38 ka and older beds from 2.3 ka to 5.4 ka. A period devoid of beachrock formation was attested between 3.5 ka and 2.3 ka.Yayın Optical stimulated luminescence dating study of eolianite on the Island of Bozcaada, Turkey: Preliminary results(The Coastal Education and Research Foundation, 2010-07) Güneç Kıyak, Nafiye; Erginal, Ahmet EvrenIn the present paper, eolianite exposed on the south coast of the semiarid island of Bozcaada, Turkey, was investigated on the basis of geomorphologic and petrographic data, and optically stimulated luminescence (OSL) dating results. The eolianite is lithic arenite in composition and contains abundant quartz, calcite, and various lithoclasts amalgamated with micritic calcite, sparitic calcite, and meniscus cements. Within the youngest layers standing at 1-2 m above sea level, the rock contains rhizoliths with or without carbonaceous fills. The OSL ages obtained ranged between 24.21 +/- 1.53 ka and 16.18 +/- 1.70 ka, suggesting that eolianite constitutes an example of low stand deposits coinciding with oxygen isotope stage 2 (OIS-2).Yayın Eolianite and coquinite as evidence of MIS 6 and 5, NW Black Sea coast, Turkey(Elsevier B.V., 2017-04) Erginal, Ahmet Evren; Güneç Kıyak, Nafiye; Selim, Hamit Haluk; Bozcu, Mustafa; Öztürk, Muhammed Zeynel; Ekinci, Yunus Levent; Demirci, Alper; Elmas, Elmas Kırcı; Öztürk, Tuğba; Çakır, Çağlar; Karabıyıkoğlu, MustafaThis paper discusses the implications of a lowstand carbonate eolianite and overlying transgressive sequence of coquinite at Şile on the Turkish Black Sea coast based on composition, depositional characteristics and optical age estimations. The cross-bedded eolianite is a mixed ooid quartz grainstone in composition, yielding a depositional age matching MIS 6. It formed at the backshore of the paleobeach with the supply of sediment the from the beach face and offering insights into the drift of mixed shallow marine carbonates and siliciclastics together with radial ooids by onshore winds from a subaerially exposed high- to low-energy ooid shoals and oolitic sand complexes which developed parallel to the shoreline on the shallow shelf margin. During this lowstand, a low-relief dune retaining a record of opposing paleowind directions than that of prevalent northeasterly winds of today appears to have been lithified to form dune rock (aeolinite) under drier conditions compared to the present. Coinciding with MIS 5e, shallow marine coquina beds resting unconformably on the eolianite indicate the occurrence of the Mediterranean transgression during the last interglacial, as confirmed by benthic foraminifera within the high-salinity tolerant coquina shells.Yayın On the origin and age of the Ariburnu Beachrock, Gelibolu Peninsula, Turkey(Scientific Technical Research Council Turkey-TUBITAK, 2008-03-13) Erginal, Ahmet Evren; Güneç Kıyak, Nafiye; Bozcu, Mustafa; Ertek, Topçu Ahmet; Güngüneş, Hakan; Sungur, Ali; Türker, GülenThe beachrock formation on the Ariburnu coast situated in the Gelibolu Peninsula has been studied by field observation, thin-section interpretation, physicochemical analyses including ICP-AES and SEM/EDS, and OSL dating. These analyses reveal the presence of different amounts of major (Si, Ca, Mg, K, Fe, Al and Na) and trace elements within the beachrock cement with Si (36.2%) and Ca (32.68%) dominating the overall composition. Beachrocks composed of highly-fractured and friable beds reach a total thickness of 80 cm extending from + 60 cm at the uppermost level down to-1 m at their most seaward extent and grade from conglomerate to lithic arkose in vertical section. The total amount of CaCO(3) ranges between 59.08% and 36% and the cement consists of high-Mg calcite based on EDS analysis. From SEM examination, four main morphologies were identified in cement material: (1) micritic coatings, (2) cryptocrystalline pore-filling cement, (3) meniscus cement and (4) microbial cement and suggest the presence of marine phreatic conditions with the exception of meniscus bridges, which imply that cementation may have been dominated by carbonate-rich meteoric waters at any successive stage of cementation. Five buried beachrock samples under unconsolidated beach sand were sampled for Optically Stimulated Luminescence (OSL) dating and show that the minimum and maximum ages of beachrock are 1.42 +/- 0.20 ka and 2.28 +/- 0.28 ka BP, respectively.Yayın First note on marine-like cementation of Late Holocene beachrock, Iznik Lake (Turkey)(Versita, 2012-03) Erginal, Ahmet Evren; Güneç Kıyak, Nafiye; Öztürk, Muhammed Zeynel; Yiğitbaş, Erdinç; Bozcu, Mustafa; Avcıoğlu, Mustafa; Öztürk, BeyhanMicro-fabric characteristics and optically stimulated luminescence (OSL) dating results are presented to discuss the controlling agents and timing of beachrock cementation on the fresh-water Iznik Lake shoreline. The beachrocks are made up of grain-supported polygenic conglomerate containing 20.42% carbonate with encrusted grains, basically as micrite coatings, isopachous aragonite rims, cryptocrystalline void fills and meniscus bridges. The optical ages of twelve samples yielded ages that range from 4.226 +/- 0.569 ka on the lowermost beds to 0.706 +/- 0.081 on the uppermost. This is the first report of precipitation of marine-like cements in Iznik Lake. The abundant aragonite-dominated cement is likely indicative of precipitation-prone dry evaporative conditions from the climatic optimum to the last millennia.Yayın Luminescence dating of prehistoric site of smintheion (Gulpinar) in NW Turkey(Univ Agean, Dept Mediterranean Stud, 2010) Güneç Kıyak, Nafiye; Takaoğlu, Turan; Erginal, Ahmet Evren; Özcan, HalilThis study aims to place the prehistoric settlement of Smintheion in northwestern Turkey in its temporal setting on the basis of the dating of the quartz from pottery and sediments collected from the site employing Optically Stimulated Luminescence and Thermoluminescence techniques. The site belongs to the problematic Middle Chalcolithic period in western Anatolia. This period represents a cultural upheaval in western Anatolia as it has a completely different material culture when compared to that of the preceding Early Chalcolithic period. The pottery and sediment samples were collected from two different locations of the Middle Chalcolithic settlement at Smintheion for dating study. The fact that this examined settlement is represented by a single cultural level provides an opportunity to obtain secure and reliable dates for the settlement. Results of this study show that the site can be dated to a period between 4800 and 4500 B.C.Yayın Quaternary rock uplift rates and their implications for the western flank of the North Anatolian Fault restraining bend; inferences from fluvial terrace ages(Blackwell Publishing Ltd, 2020-10-01) McClain, Kevin P.; Yıldırım, Cengiz; Ciner, Attila; Şahin, Sefa; Sarıkaya, Mehmet Akif; Özcan, Orkan; Güneç Kıyak, Nafiye; Öztürk, TuğbaIn the western flank of the North Anatolian Fault restraining bend (i.e., Central Pontides), the Filyos River incises through the uplifting Karabük Range, creating the ~1.7-km-deep Filyos River Gorge on the hanging wall of the reverse Karabük Fault. Seven fluvial strath terrace levels are preserved in this gorge. optically stimulated luminescence ages from quartz-rich sediments of five terrace levels reveal an average long-term rock uplift rate of 0.45 ± 0.02 mm yr?1 with an unsteady pattern of uplift during the last 542 ± 24 kyr. Uplift rates of 1.52 ± 0.6 and 0.74 ± 0.3 mm yr?1 occurred before 366 ± 19 kyr, followed by lower rates of ~0.1 and 0.31 mm yr?1 through present. These later uplift rates may reflect relatively slower tectonic rates since ~366 kyr, with closer similarity to regional uplift rates of ~0.3 mm yr?1 yielded from the eastern flank of the Central Pontides. The Karabük Range fluvial terraces are near the North Anatolian Fault, meaning pre- ~366 kyr uplift rates may be a glimpse of the highest Central Pontides Quaternary rock uplift rates on uplifting hanging wall blocks activated by the restraining bend. When we consider offshore seismic reflection data, the focal mechanism solution of the Bartın Earthquake, onshore structural data, and regional tectonic geomorphology, the western flank of the Central Anatolian Plateau's northern margin is propagating northward as a growing orogenic wedge with a positive flower-structure geometry.Yayın River, alluvial fan and landslide interactions in a tributary junction setting: Implications for tectonic controls on Quaternary fluvial landscape development (Central Anatolian Plateau northern margin, Turkey)(Elsevier B.V., 2021-03-01) McClain, Kevin P.; Yıldırım, Cengiz; Çiner, Tahsin Attila; Sarıkaya, M. Akif; Özcan, Orkan; Görüm, Tolga; Köse, Oğuzhan; Şahin, Sefa; Güneç Kıyak, Nafiye; Öztürk, TuğbaAlong the western flank of the northern margin (Central Pontides) of the Central Anatolian Plateau, the humidity from the Black Sea is much higher than the central and eastern flanks and creates a complex relationship between surface and tectonic processes by triggering intense mass wasting activity and aggradation within narrow valleys. We identified three incised fill terrace levels and used Optically Stimulated Luminescence (OSL) dating to calculate fluvial sediment ages and cosmogenic 36Cl exposure dating to calculate limestone boulders exposure ages across the terrace surface. Stratigraphical interpretations and OSL ages of the lowest levels revealed that a fluvial fill terrace formed in the main valley at 275.6 ± 12.8 ka and was overlain by a main river-tributary junction alluvial fan that was abandoned at 39.5 ± 3.5 ka. The results collectively show the influence of climate, topography, hillslope processes, and lithology on aggradation-incision patterns of main rivers. Prolonged aggradation can prevent the channel equilibrium required to calculate rock uplift rates while also causing a new base-level and aggradation upstream. This effect can be exacerbated in uplifting mountainous regions with limited depositional areas. Bedrock incision rates based on the fluvial terrace age were between 0.15 and 0.2 mm/a since 39.5 ± 3.5 ka. However, the high aggradation within this segment of the main valley prevented incision of the channel bedrock for long periods, causing a potential underestimation of the rock uplift rate calculation. Our local period of aggradation appears to be related to increased aggradation and decreased bedrock incision rates measured 14 km upstream that were previously assumed to be the result of decreased tectonic uplift rates. This demonstrates the importance of corroborating strath terrace incision rate estimations with ages and incision rates of downstream fill terraces, if present, to check for potential interference with the tectonic signal.Yayın Cementation characteristics and age of beachrocks in a fresh-water environment, Lake Iznik, NW Turkey(Elsevier Science BV, 2012-12-01) Erginal, Ahmet Evren; Güneç Kıyak, Nafiye; Öztürk, Muhammed Zeynel; Avcıoğlu, Mustafa; Bozcu, Mustafa; Yiğitbaş, ErdinçThis paper focuses on the cement characteristics and optical luminescence age of late Pleistocene-Holocene beachrock, exposed on the southeast shore of freshwater Lake Iznik in northwest Turkey, based on field observations, various spectroscopic analyses and optical dating results. The studied beachrock is a poorly-sorted coastal conglomerate composed mostly of gravels derived from surrounding volcanic rocks and marbles as well as quartz and carbonate grains. We identified different types of cements; dominated by micritic envelopes, bladed isopachous aragonite rims, void fills, radial aggregates and meniscus bridges, implying no single origin. Cementation characteristics indicate that marine-like cement micro-fabrics may occur in freshwater lake environments where the lake-water chemistry favors carbonate precipitation. OSL data revealed the existence of older beachrock dating back to 20.2 ka, together with younger Holocene-age beachrock of between 5.6 and 2.4 ka. This suggests that younger beachrocks have been superimposed on older cemented carbonates through the removal of carbonates by wave motion (splash and spray) during lower lake level conditions.
