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Yayın Dating fossil root cast (Black Sea coast, Turkey) using thermoluminescence: Implications for windblown drift of shelf carbonates during MIS 2(Elsevier Ltd., 2016-05-16) Polymeris, George S.; Kitis, George; Güneç Kıyak, Nafiye; Theodosoglou, Eleni; Tsirliganis, Nestor C.; Ertek, Topçu Ahmet; Erginal, Ahmet EvrenRhizoliths are mostly sub-aerially exposed root prints which appear through removal of the rock units that cap them. A horizontal-lying residual of a rhizolith, consisting purely of soft inner core material of white color was recovered 10 km west of Şile, Istanbul, in northwest Turkey within laminated oolithic massive aeolianite. The inner part, consisting purely of calcium carbonate, was dated by applying thermoluminescence, while for the outer shelves optically stimulated luminescence of quartz was used for age assessment. The age of the CaCO3 infill occupying the original place of the decayed plant roots was found to be 26.8 (±5.0) ka, corresponding to MIS 2. When compared with the ages of the middle (105.2 ± 15.6 ka) and outer (127 ± 9 ka) layers, corresponding to the later stage of MIS 5e or early stage of MIS 5d, the inner core coincides with the last glacial period when the sea-level was lower than the present, promoting transportation of ooids by offshore winds in conjunction with the exposed shelf carbonates. Based on the results yielded, rhizolith is much younger than the host rock aeolianite and witnesses to last glacial sea level lowstand when removal of shelf carbonates by offshore winds was promoted from the exposed shallow shelf plain. The results provide strong evidence that rhizoliths may not be coeval with the aeolianites within which they are embedded.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.
