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@PHDTHESIS{Parplies:1273,
author = {Parplies, Jörn},
title = {{I}sotopengeochemische {S}tudien zur klimatischen
{A}usprägung des {J}üngeren {D}ryas in terrestrischen
{A}rchiven {E}urasiens},
volume = {18},
issn = {1866-1793},
school = {Univ. Köln},
type = {Dr. (Univ.)},
address = {Jülich},
publisher = {Forschungszentrum Jülich GmbH Zentralbibliothek,
Verfasser},
reportid = {PreJuSER-1273},
isbn = {978-3-89336-542-5},
series = {Schriften des Forschungszentrums Jülich : Energie $\&$
Umwelt / Energy $\&$ Environment},
pages = {XL, 155 S.},
year = {2008},
note = {Record converted from VDB: 12.11.2012; Köln, Univ., Diss.,
2008},
abstract = {In this thesis, the late glacial climate and environment
development with special focus on the Younger Dryas
chronozone was studied for three different regions in
Eurasia. For this purpose, lacustrine sedimentary archives
of Lake Meerfelder Maar (Westeifel, Germany), Lake Sacrow
(Brandenburg, Germany) and Lake Sihailongwan (NE-China) were
investigated by means of isotopic and geochemical methods.
Stable isotope ratios of organic carbon, nitrogen and oxygen
as well as element contents of organic carbon and nitrogen
were measured with high time-resolution. Oxygen isotope
ratios of diatomaceous opal (Lake Meerfelder Maar, Lake
Sihailongwan) and autochthonous inorganic carbonates (Lake
Sacrow) were determined. Separation of diatom valves from
bulk sediments was achieved by the method of
SPLITT-fractionation for Lake Meerfelder Maar and a newly
optimised heavy liquid density centrifugation for Lake
Sihailongwan. Determination of oxygen isotope ratios
followed the iHTR method and isotope ratio mass spectrometry
(IRMS). The late glacial chronozones Bølling / Allerød,
Younger Dryas and Preboreal are documented in the sediment
profiles of all three investigation sites which basically
confirms the hypothesis of a hemispheric character of these
climate stages. The Younger Dryas is characterised as a time
period of distinct cooling in all three archives. Moreover,
an increased allochthonous influx into the sediments is
observed for all archives during that time. This is due to a
less dense vegetation cover and partly frozen soils during
very cold winters. A shortening of the vegetation period
associated with an intraannual concentration of lacustrine
primary production is inferred from the alignment of
$\delta^{18}$O$_{SiO_{2}}$-values of different diatom size
fractions from Lake Meerfelder Maar. Oxygen isotope ratios
were particularly useful for the reconstruction of climate
since they depend directly on climatic driving factors.
However, the direct dependence of $\delta^{18}$O-values on
lake water temperature during formation of diatoms and
carbonates was superimposed by larger variations in the
$\delta^{18}$O$_{H_{2}O}$-source value of lake water.
Temperature reconstructions based on oxygen isotope
variations suggest a decrease of weighted mean annual
temperatures in Central Europe in the range of approx. 4.5
– 6.5 °C during the Younger Dryas. Since precipitation
most likely occurred mainly during spring and summer, the
weighted signal is [...]},
cin = {ICG-5},
ddc = {333.7},
cid = {I:(DE-Juel1)VDB143},
pnm = {ohne FE},
pid = {G:(DE-Juel1)FUEK307},
typ = {PUB:(DE-HGF)11 / PUB:(DE-HGF)3},
url = {https://juser.fz-juelich.de/record/1273},
}