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| Titel |
Age–depth model of the past 630 kyr for Lake Ohrid (FYROM/Albania) based on cyclostratigraphic analysis of downhole gamma ray data |
| VerfasserIn |
H. Baumgarten, T. Wonik, D. C. Tanner, A. Francke, B. Wagner, G. Zanchetta, R. Sulpizio, B. Giaccio, S. Nomade |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1726-4170
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| Digitales Dokument |
URL |
| Erschienen |
In: Biogeosciences ; 12, no. 24 ; Nr. 12, no. 24 (2015-12-17), S.7453-7465 |
| Datensatznummer |
250118220
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| Publikation (Nr.) |
 copernicus.org/bg-12-7453-2015.pdf |
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| Zusammenfassung |
| Gamma ray (GR) fluctuations and potassium (K) values from downhole logging
data obtained in the sediments of Lake Ohrid from 0 to 240 m below lake
floor (b.l.f). correlate with fluctuations in δ18O values from the
global benthic isotope stack LR04 (Lisiecki and Raymo, 2005). GR and K values
are considered a reliable proxy to depict glacial–interglacial cycles, with
high clastic input during cold and/or drier periods and high carbonate
precipitation during warm and/or humid periods at Lake Ohrid. Spectral
analysis was applied to investigate the climate signal and evolution over the length of
the borehole. Linking downhole logging data with orbital cycles was used to
estimate sedimentation rates and the effect of compaction was compensated
for. Sedimentation rates increase on average by 14 % after decompaction
of the sediment layers and the mean sedimentation rates shift from
45 cm kyr−1 between 0 and 110 m to 30 cm kyr−1 from 110 to
240 m b.l.f. Tuning of minima and maxima of gamma ray and potassium values
versus LR04 extrema, in combination with eight independent
tephrostratigraphical tie points, allows establishing of a robust age model
for the downhole logging data over the past 630 kyr. |
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