Publication Date:
2014-09-03
Description:
The last glacial maximum and late glacial environmental and climatic variability in the Baikal region,
southern Siberia, Russia has been studied in a sediment sequence from Lake Kotokel, located 2 km east of
Lake Baikal, using the oxygen isotope composition of diatom silica (d18Odiatom). The purification of diatom
frustules involved the process of trimethylsilylation, which has been shown to be suitable for preparation
of diatoms for oxygen isotope analysis. The Lake Kotokel d18Odiatom record presented here spans intervals
from about 24.6 to 22.9 ka BP (further referred to as ‘last glacial maximum’) and ~16.7-11.5 ka BP
(further referred to as ‘late glacial’) displaying variations in the oxygen isotope composition
between +26.7 and +31.2‰. Overall high d18Odiatom values of about +29 to +31‰ during the two
investigated intervals characterize a strongly evaporative lake system in a dry environment and suggest a
lower than present lake level due to enhanced evaporation. The Lake Kotokel diatom isotope record is
roughly in line with the 60° N summer solar insolation, pointing to a linkage to broader-scale climate
change, but displays weaker reaction to short-term climatic oscillations, i.e. Bølling-Allerød or Younger
Dryas. The climate warming at ~14.3 ka BP is marked by negative spikes in the d18Odiatom record due to
isotopically low melt water input from the mountainous hinterland.
Repository Name:
EPIC Alfred Wegener Institut
Type:
Article
,
isiRev
Format:
application/pdf
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