25th International Meeting on Organic Geochemistry IMOG 2011

O-63
Simultaneous shifts in temperature in Central Europe and
Greenland during the last deglaciation
Cornelia I. Blaga 1 , Gert-Jan Reichart 1 , Andre F. Lotter 1 , Flavio S. Anselmetti 2 , Jaap S.
Sinninghe Damsté 3
1 Utrecht University, Utrecht, Netherlands, 2 Eawag, Dübendorf, Switzerland, 3 NIOZ, Den Burg, Netherlands
(corresponding author:blaga@geo.uu.nl)
The transition from the cold Last Glacial to the
warmer early Holocene is well documented in glacier
ice and marine sediments. Also from the continental
realm a large number of high-resolution records exist,
however, independent quantitative continental proxies
are scarce but important for our full understanding of
the climate system. Palaeoclimatic studies focusing
on the last deglaciation showed unstable climatic
conditions in Central Europe, based on correlations of
isotope records, pollen, cladoceran and chironomids
from lakes in Germany and Switzerland with the
Greenland isotope records.
Here we present the first decadal-resolution record of
the dynamic continental temperature changes in
Central Europe during the last deglaciation (~14,600
to 10,600 cal. yr BP) based on the organic
geochemical palaeothermometer TEX86. We analyzed
changes in isoprenoid and branched GDGTs in 200
contiguous samples encompassing the Glacial-
Interglacial transition as well as the Late Glacial
Interstadial in a core from Lake Lucerne
(Vierwaldstättersee). To determine where and when
glycerol dialkyl glycerol tetraether (GDGT) membrane
lipids are produced, we collected descending particles
using two sediment traps with a monthly resolution
from January 2008 to late March 2009. Suspended
particulate matter (SPM) was monthly filtered from the
water column at three different depths. Fluxes of
GDGTs and their concentrations in the water column
vary according to a seasonal pattern, showing a
similar trend in the SPM and sediment traps. Fluxes
and concentrations of isoprenoid GDGTs increase
with depth, maximum values being observed in the
deeper part of the water column, indicating production
of isoprenoid GDGTs by Thaumarchaeota in the deep
(~50 m), aphotic zone of Lake Lucerne. The fluxweighted
average of TEX86 is consistent with a
deeper water origin.
Our sedimentary record shows a remarkable
resemblance with the Greenland stable oxygen
isotope record on the centennial timescale. The
TEX86-inferred lake temperature record reveals the
typical oscillations during the Late Glacial Interstadial,
followed by an abrupt cooling of 1.2°C at the onset of
Younger Dryas and a rapid warming of 4-5°C at the
Younger Dryas/Holocene transition within less than
200 years. BIT values vary between 0.2 and 0.5 with
relatively high values in the middle part of the record.
Thus, the BIT record clearly reflects changes in
landscape openness and soil erosion in the
hydrological catchment. Our data imply that the
regional temperature changes in continental Europe
were dominated by large-scale reorganizations in the
northern hemispheric climate system.
Fig. 1 Comparison of the high resolution BIT, TEX86
and TEX86-inferred temperature record from
sediments of Lake Lucerne with the δ 18 O values from
the NGRIP record. Thick black line represents the
three-point moving average.
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