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    Formation of Holocene paleosols in a relict sand dune sequence at Kıyıköy, Türkiye
    (Tubitak Scientific & Technological Research Council Turkey, 2025) Erginal, Ahmet Evren; Bozcu, Mustafa; Yakupoglu, Nurettin; Akbas, Abdullah; Kaya, Hakan; Tunc, Ismail Onur
    The paleoclimatic indicators from a relict dune and paleosol sequence observed south of K & imath;y & imath;k & ouml;y Port, NW T & uuml;rkiye, provide insights into the variable paleoclimatic conditions in the western Black Sea coastal zone over the last 4700 yrs BP. The relict dunepaleosol sequence consists of reddish-brown coarse sands with abundant shells and overlying paleosol. Radiocarbon dating of Donax trunculus shells collected from the lowest part of the relict dune revealed the onset of sand deposition 4689 +/- 123 yrs ago. The dark-colored paleosol layer, with an Rb/Sr ratio of 0.008, yielded an age of 287 +/- 32 yrs cal BP. These findings indicate that the paleosol developed around the 1700s, during one of the coldest phases of the Little Ice Age. This layer is followed by a brown-colored buried soil, indicating a short-lived humid and rainy period, as evidenced by an Rb/Sr ratio of 0.42.
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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; Cagatay, M. Namik; Selim, H. Haluk; Karabiyikoglu, Mustafa; Cakir, Caglar; Yakupoglu, Nurettin; Acar, Dursun
    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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    Öğe
    Termination of Little Ice Age in Northeastern Anatolia: A Multi-proxy Paleolimnology Study of Lake Aygir Sediments, (Kars, NE Anatolia)
    (Tmmob Jeoloji Muhendisleri Odasi, 2022) Erginal, Ahmet Evren; Yakupoglu, Nurettin; Cakir, Caglar; Akbas, Abdullah; Kukrer, Serkan
    Sedimentary, geochemical and stable isotope analyses of a sediment core (core AY) recovered from Lake Aygir (NE Anatolia) provide evidence of the climatic shifts during the last similar to 500 yrs. Sediments in Lake Aygir are composed of silty clay with a modeled similar to 0.16 cm/yr sedimentation rate. Multi-proxy analyses of the downcore distribution of detritally-deposited proxy elements, total calcium carbonate, organic carbon and stable isotopes reveal climatic records of the Industrial Epoch (IE; 18th-19th centuries) and the termination of the Little Ice Age (LIA; AD 1350 to 1850), represented by fluctuating Total Organic Carbon (TOC), Ca, Sr and relatively low detrital precursors (Fe, Ti, K, Rb, Zr), indicating low chemical weathering and dry conditions. The upper part of the core (192 cal yrs BP to present), identified with high detrital input, contains an increasing trend of Fe, Ti, K, Rb, and Zr together with high delta O-18 and delta C-13 values, indicating warmer conditions during the IE.