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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 New quartz technique for OSL dating of limestones(2010) Liritzis, Ioannis; Drivaliari, N.; Polymeris, George S.; Katagas, Christos G.The equivalent dose De determination of limestone-made ancient constructions by thermoluminescence (TL) prevents accurate measurements and requires plateau test of bleached curves. Optical stimulated luminescence (OSL) of quartz and feldspar minerals for surface dating is routinely applied for De but not for limestones. Here the OSL of present traces of such minerals removed with powder from surface limestone bleached by sunlight overcomes this issue and offers an alternative way for De. This is verified with further test examples.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 IRSL dating of a deep water core from Pylos, Greece; comparison to post ir blue OSL and TL dating results(Univ Agean, 2011) Polymeris, George S.; Kitis, GeorgeThe 'double SAR' protocol procedure permits the determination of two equivalent dose (De) values for each polymineral aliquot; an IRSL De resulting mostly from feldspars along with a post-IR OSL De for a mixed signal for quartz (mostly) and feldspar grains. The objective of the present study is to test for the first time its usefulness for polymineral, coarse silt, closely-spaced deep-sea sediment samples. A new, 'double SAR' IRSL dataset is presented for the sedimentation ages of a deep-sea sediment core of the Hellenic Trench, drilled from a water depth of 4 km, near the deepest site of the Mediterranean Sea, outside Pylos, Greece. Post IR quartz-based optical dating was previously proved to be consistent with AMS radiocarbon ages, obtained from planktonic foraminifera from the same core. IRSL De values are, with one exception, always much greater than the corresponding (post-IR) OSL results. This result suggests that for the present study 'double SAR' protocol procedure was proved to be extremely effective method for separating the luminescence signals from quartz and feldspars. Furthermore, De values obtained after infra-red stimulation and thermoluminescence generally agree within errors. This quantitative equivalence of those two sets of De values implies that as in the case of IRSL, TL signal is also feldspar-dominated. IRSL ages vary between 3.5 and 7.8 ka with associated errors up to 9%. Application of 'double SAR' protocol to coarse silt, closely-spaced deep-sea sediment samples seems advisable, despite the fact that the post-IR blue OSL signal is the most stable signal, and is preferred for dating.Yayın Equivalent dose in quartz from young samples using the SAR protocol and the effect of preheat temperature(Pergamon-Elsevier Science Ltd, 2006-09) Güneç Kıyak, Nafiye; Canel, TimurMajor concerns in the dating of samples younger than a few hundred years by the optically stimulated luminescence (OSL) technique are thermal transfer and partial bleaching. Thermal transfer during preheating enhances the OSL signal due to the charge transfer from thermally sensitive, but light-insensitive, traps to optical centres of quartz and results in an overestimate in equivalent dose, especially for very young samples. In this study, the single-aliquot regenerative-dose protocol is used to obtain values of equivalent dose (D-e) from young samples taken from various environments around Istanbul. Within this framework, we aim to investigate the effect of preheat temperature on equivalent dose from 150 to 300 degrees C, the reproducibility of De measurements for young deposits and the contribution from thermal transfer of charge to the equivalent dose estimation. It was observed that the measured dose is influenced significantly by preheat temperature and the increase in the De is clearly due to thermal transfer of charge from deep thermally sensitive traps to OSL trap during preheating of the samples prior to the main OSL measurements.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 Analyses of seismic deformation at the Kibyra Roman stadium, southwest Turkey(Wiley-Blackwell, 2013-11) Karabacak, Volkan; Yönlü, Önder; Dökü, Feyzullah Eray; Güneç Kıyak, Nafiye; Altunel, Erhan; Özüdoǧru, Şükrü; Yalçıner, Cahit Çağlar; Akyüz, Hüsnü SerdarThe ancient city of Kibyra in southwest Turkey has the potential to reveal the location and date of historical earthquakes. The most compelling evidence for earthquake faulting is observed in the city's Roman stadium. Damage related to seismic shaking is characterized by systematically collapsed columns, dilated and collapsed walls, and by rotated and displaced blocks in the stadium. Detailed archaeoseismological observations suggest that Kibyra was affected by earthquakes that were also recorded in historical earthquake catalogs. Although there is no historical record of a large earthquake after the 5th century A.D., Optically stimulated luminescence (OSL) dating of deposits under the collapsed blocks suggests a later seismic event. OSL results indicate that another large event occurred in southwest Turkey, probably around the 10-11th century A.D., and caused extensive damage (I-o = VIII-IX) to the Kibyra stadium.
