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    Environmental changes based on multi-proxy analysis of core sediments in Lake Aktas, Turkey: Preliminary results
    (Pergamon-Elsevier Science LTD, 2018) Kılıç, Nurgül Karlıoğlu; Caner, Hülya; Erginal, Ahmet Evren; Ersin, Sinem; Selim, H. Haluk; Kaya, Hakan
    A sediment core covering the last millennium from Lake Aktas, a shallow alkaline soda lake in the northeast Anatolian highland of Turkey, was studied for pollen and physical and chemical proxies to reconstruct past climate change. The sediments were dated by AMS radiocarbon dating of bulk organic carbon. Among arboreal pollen (AP) from around 930 years ago, dominant trees were Pinus sylvestris, Picea orientalis, Abies, Betula, Fagus, and Quercus. AP exceeded NAP (non-arboreal pollen) in this time, whereas the opposite is the case in a pollen trap in the same region collecting the pollen for one year in 2015-2016. The comparison of modern and fossil pollen influx indicates that in that period trees were more widely distributed around the lake than today, where steppe vegetation now prevails. Inferred causes for the disappearance of trees are anthropogenic impacts and climatic change towards more continental conditions. The results also identify the onset of the Little Ice Age in the NE Anatolian highland of Turkey. (C) 2018 Elsevier Ltd and INQUA. All rights reserved.
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    Eolianite and coquinite as evidence of MIS 6 and 5, NW Black Sea coast, Turkey
    (Elsevier B.V., 2017) Erginal, Ahmet Evren; Karabıyıkoğlu, Mustafa; Selim, H. Haluk
    This 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. © 2017 Elsevier B.V.
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    MULTI-PROXY SEDIMENTARY RECORDS OF DRY-WET CLIMATE CYCLES DURING THE LAST 2 KA FROM LAKE CILDIR, EAST ANATOLIAN PLATEAU, TURKEY
    (Comitato Glaciologico Italiano, 2019) Erginal, Ahmet Evren; Cağatay, M. Namık; Selim, H. Haluk; Karabıyıkoğlu, Mustafa; Çakır, Cağlar; Yakupoğlu, Nurettin; Kaya, Hakan
    Multi-proxy analyses together with AMS radiocarbon dating of sedimentary organic carbon of a sediment core from Lake Cildir, NE Turkey was carried out to study temporal changes in climate over the last two millennia. The lake is characterized by very fine to coarse silt-sized, carbonate-free sediments deposited at a relatively low sedimentation rate of less than 0.31 mm/yr. Results from element geochemistry, total organic carbon (C-org), and physical properties (gamma density and magnetic susceptibility results testified the occurrence of alternating cycles of drier and wetter climatic periods since about 2.2 ka cal BP. The period from 2166 +/- 112 cal BP to the onset of Little Ice Age, including the Medieval Climatic Anomaly, is represented by alternation of warm and wet conditions with intervening relatively low-magnitude dry periods. The cold Little Ice Age period, on the other hand, was dry, with upward decreasing trends of Zr and Ti and C-org as well as relatively low values of Rb/Sr, indicating decreasing chemical weathering intensity in the drainage basin and low organic productivity in the lake.
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    Raised braided stream gravels on Mount Keldağ, Hatay (Eastern Mediterranean coast, Turkey): Implications of transformation to beachrock and ensuing tectonic uplift
    (Springer Science and Business Media B.V., 2019) Erginal, Ahmet Evren; Polymeris, Georgios S.; Karataş, Atilla; Giannoulatou, Valeria; Şahiner, Eren; Meriç, Niyazi; Erenoğlu, Oya; Selim, Hamit Haluk; Karabıyıkoğlu, Mustafa
    On the seaward northwest slopes of Mount Keldağ, Hatay, the combination of an unconformably overlapping sequence of cemented gravels on a wave-cut platform, and a raised notch and irregular pits left by grazing molluscs on the walls of this notch, carved in an NE-trending high-angle fault plane, retain the record of raised braided stream gravels transformed into beachrock. From the OSL ages, this study reveals that deposition of this sequence occurred between 232.30 ± 31.62 and 214.01 ± 27.42 ka during the penultimate interglacial. The four distinct facies identified are massive matrix-supported conglomerate, massive to crudely stratified gravel, cross-stratified gravel, and clast-supported open-work gravel. Extending to the paleo-coastline during the MIS7 highstand, this sequence was cemented by carbonate and iron-oxide cements and records an uplift of around 0.1 mm/year up to the present.