caa a22 4500 606149260 CHVBK 20210128100533.0 cr unu---uuuuu 210128e20150901xx s 000 0 eng 10.1007/s00531-014-1082-x doi (NATIONALLICENCE)springer-10.1007/s00531-014-1082-x Cyclostratigraphic studies of sediments from Lake Van (Turkey) based on their uranium contents obtained from downhole logging and paleoclimatic implications [Elektronische Daten] [H. Baumgarten, T. Wonik] A deep drilling campaign was performed at Lake Van (Turkey) to enhance the understanding of the paleoenvironmental conditions of the Middle East. Cores were collected, and the sediments are mainly composed of clayey silts and tephra deposits. Spectral gamma ray data were acquired (0-210m below lake floor), and the uranium data were used for cyclostratigraphic studies to estimate the sedimentation rates and the time of deposition. Detection and analysis of climate cycles require continuous sedimentation and cannot be applied to these sediments which include numerous tephra layers. Therefore, these layers were removed, and a synthetic log was created (cumulative thickness of the tephra≈50m; remaining lacustrine sediments≈160m). High amplitudes were detected and correlated to Milanković cycles. Their evolution was analyzed using the sliding window technique. The sedimentation rates varied from 22 to 33cm/ka in the upper section. The sediments between the lake floor and a depth of 210m were deposited over a period of 587ka. Our results agree with core interpretations (e.g., correlation of total organic carbon with marine isotope stages) which suggest a time span of deposition of 600ka. High-frequency cycles were detected and correlated with interstadials from the North Greenland δ18O record for the past 75ka. The two datasets agreed closely. We conclude that climate signals, even on sub-Milanković scale, are imprinted in uranium of these sediments, and cyclostratigraphic methods are applicable if event layers are subtracted from the sediment record. The Author(s), 2014 Lake sediments nationallicence Paleoclimate nationallicence Quaternary nationallicence Downhole logging nationallicence Cyclostratigraphy nationallicence Sedimentation rates nationallicence Baumgarten H. Leibniz Institute for Applied Geophysics (LIAG), Stilleweg 2, 30655, Hannover, Germany aut Wonik T. Leibniz Institute for Applied Geophysics (LIAG), Stilleweg 2, 30655, Hannover, Germany aut International Journal of Earth Sciences Springer Berlin Heidelberg 104/6(2015-09-01), 1639-1654 1437-3254 104:6<1639 2015 104 531 https://doi.org/10.1007/s00531-014-1082-x text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s00531-014-1082-x text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Baumgarten H. Leibniz Institute for Applied Geophysics (LIAG), Stilleweg 2, 30655, Hannover, Germany aut NATIONALLICENCE 700 1- Wonik T. Leibniz Institute for Applied Geophysics (LIAG), Stilleweg 2, 30655, Hannover, Germany aut NATIONALLICENCE 773 0- International Journal of Earth Sciences Springer Berlin Heidelberg 104/6(2015-09-01), 1639-1654 1437-3254 104:6<1639 2015 104 531