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Yayın A comparative morphological, compositional and tl study of tenedos (Bozcaada) and Sile aeolianites, Turkey(Univ Agean, 2012) Polymeris, George S.; Erginal, Ahmet Evren; Güneç Kıyak, NafiyeAeolianites are carbonate-cemented deposits of coastal dune sands, mostly of Quaternary age. Even though aeolianite exposures on the coasts of the Mediterranean Sea are frequent, very few records have been documented from the coasts of either the Aegean or the Black Sea. The present study deals with evaluating and comparing both compositions and thermoluminescence (TL) ages of two recently reported samples of coastal aeolianites. Both were recovered at the Turkish coasts of Tenedos (Bozcaada) island, Aegean Sea and Şile, Western Black Sea. In the latter case, being the first record for the specific coastal area, the oldest age obtained was dated at 158±25 ka while the youngest age yielded was 108±14 ka. These values imply that both deposition and cementation occurred during the high sea stand of marine isotope stage 5 (MIS 5). In the case of Tenedos, the aeolianites were deposited between the early stage of the oxygen isotope stage 2 period (OIS 2) and the very late phase of the oxygen isotope stage 3 period (OIS 3). These latter TL results are in excellent agreement with a previous study of the same complex after applying OSL. Besides the ages, a number of luminescent features and properties in conjunction with compositional data suggest the dissimilarity for the quartz samples extracted from the aeolianites recovered at these two sampling sites, excluding thus any transport from one sampling site to the other, despite the short distance of the two sampling sites and the meteorological data regarding the preferable wind directions between them.Yayın Age, composition and paleoenvironmental significance of a Late Pleistocene eolianite from the western Black Sea coast of Turkey(Pergamon-Elsevier Science Ltd, 2013-05-16) Erginal, Ahmet Evren; Güneç Kıyak, Nafiye; Ekinci, Yunus Levent; Demirci, Alper; Ertek, Topçu Ahmet; Canel, TimurOn the basis of field observations, thin section interpretations, microanalytical data, electrical resistivity survey and luminescence dating, the age, composition and internal structure of coastal eolianite on the west Black Sea coast at Sile, Istanbul, was studied for a combined interpretation of dune rock development and facies characteristics. Results demonstrate that the eolianite is made up of south-dipping, large-scale dune stratification, consisting mainly of quartz sand and, in particular, abundant ooids, as well as the binding cement which is composed of calcite and aragonite. Based on Electrical Resistivity Tomography (ERT) images, the eolianite has a thickness of between 3.5 m and 8 m and overlies a buried rugged topography that has developed on the Pliocene unit. This suggests the predominance of northerly winds that account for the landward removal of dune sands by offshore wind drift prior to carbonate cementation. Optically Stimulated Luminescence (OSL) dating estimations revealed that the initial deposition of the laminated eolianite layers on the underlying older unit took place at 138.57 +/- 13.65 ka, matching the Karangatian highstand or Marine Isotope Stage (MIS) 5e.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.
