Paleoclimatic Indicators from Permafrost Sequences in the Eastern
Taymyr Lowland
C. Siegert l , A.Y. Derevyagin 2 , G.N. Shilova 2 , W.-D. Hermichen l and A. Hiller 3
(1) Alfred-Wegener-Institut fiir Polar- und Meeresforschung, Forschungsstelle Potsdam, Telegrafenberg A43,
D 14473 Potsdam, Germany
(2) Faculty of Geology, Moscow State University, 119899 Moscow, Russia
(3) Universitiit Leipzig, Forschungsgruppe Paliioklimatologie, Permoserstrasse 15, D 04303 Leipzig,
Germany
Revised 5 May 1997 and accepted in revised form 15 May 1998
Abstract - Permafrost sequences in the Labaz Lake area were investigated to reconstruct
their paleoenvironmental history during the Late Quaternary using geocryological field
studies, sedimentological, geochemical, stable isotopic and palynological analyses in
connection with radiocarbon dating. The current results show that during post-Zyryan (Early
Weichselian) times denudation and accumulation in this area was dominated by processes
connected with the decay of an ice cover, formed at least during the Zyryan stadia!' As a
result of the specific peculiarities of glacier ice thawing in a territory with continuous, lowtemperature permafrost, buried glacier ice bodies were preserved until the present time. The
most intensive decay of glacier ice occurred during the first warming stage of the Kargin
(Middle Weichselian) Interstadial more than 40000 yr BP. The formation of extensive lake
depressions within the glacial deposits is connected with these times. About 40000 yr BP,
a surface stabilization occurred, and syncryogenic deposits with thick polygonal ice wedges
(Ice Complexes) and peat beds were formed. Subsequent warming phases, apparently
connected with increases in precipitation, led to a new activation of glacier ice decay, and to
the accumulation of additional lacustrine and fluvio-lacustrine sediments. Palynological and
stable isotope data from ground ice suggest a continual trend to a cooler and more
continental climate from the Kargin Interstadial to the Sartan stadial times. During the
maximal cooling period, polygonal ice wedges in dried-up lacustrine deposits formed. At
the termination of the Pleistocene, lacustrine sedimentation seems to have reactivated in
reaction to short climate improvements. Thermokarst lakes were formed in this period.
Extensive peat accumulation started at the end of the Boreal and spread to flat lacustrine
depressions during the Atlantic. Since the Subboreal, a drying up of lakes and gradual
increasing of permafrost aggradation can be inferred.
Introduction
Controversy exists concerning both the extent and the age of the last glaciation in Central
Siberia. In particular, the environmental conditions during Post-Zyryan (Post-EarlyWeichselian) times are only slowly becoming clear (Astakhov, 1992; Faustova and Velichko,
1992; Isaeva and Kind, 1989; Velichko, 1993). The solution to these problems is quite
important as it would affect, firstly, the character of atmospheric circulation models during the
Late Pleistocene, and secondly, specific features of sediment transport to the Arctic Ocean.
Paleogeographical studies of permafrost sequences have been carried out in the Labaz Lake
region as part of the German-Russian research project "Taymyr" during two expeditions
(Siegert et ai., 1995; Siegert et ai., 1996). The study area represents the typical lowland
surrounding the Laptev Sea to the southwest. According to the maximal-extent reconstruction
of the Late Weichselian (Sartan) glaciation, this area was located to the east of the glaciated
territory (Velichko, 1993). Based on remote sensing and the study of sediment sequences in
surrounding river valleys, Isaeva (1982) assumed that the Late Pleistocene section at Labaz
Lake included deposits of a vast ice-dammed lake ("Pre-Labaz") that existed during the Sartan
glaciation. According to this interpretation, the level of the "Pre-Labaz" had reached a maximum
In: Kassens, H., H.A. Bauch, I. Dmitrenko, H. Eicken, H.-W. Hubberten, M. Melles, J. Thiede and L. Timokhov (eds.)
Land-Ocean Systems in the Siberian Arctic: Dynamics and History. Springer-Verlag, Berlin, 1999,477-499.
Taymyr Lowland
C. Siegert l , A.Y. Derevyagin 2 , G.N. Shilova 2 , W.-D. Hermichen l and A. Hiller 3
(1) Alfred-Wegener-Institut fiir Polar- und Meeresforschung, Forschungsstelle Potsdam, Telegrafenberg A43,
D 14473 Potsdam, Germany
(2) Faculty of Geology, Moscow State University, 119899 Moscow, Russia
(3) Universitiit Leipzig, Forschungsgruppe Paliioklimatologie, Permoserstrasse 15, D 04303 Leipzig,
Germany
Revised 5 May 1997 and accepted in revised form 15 May 1998
Abstract - Permafrost sequences in the Labaz Lake area were investigated to reconstruct
their paleoenvironmental history during the Late Quaternary using geocryological field
studies, sedimentological, geochemical, stable isotopic and palynological analyses in
connection with radiocarbon dating. The current results show that during post-Zyryan (Early
Weichselian) times denudation and accumulation in this area was dominated by processes
connected with the decay of an ice cover, formed at least during the Zyryan stadia!' As a
result of the specific peculiarities of glacier ice thawing in a territory with continuous, lowtemperature permafrost, buried glacier ice bodies were preserved until the present time. The
most intensive decay of glacier ice occurred during the first warming stage of the Kargin
(Middle Weichselian) Interstadial more than 40000 yr BP. The formation of extensive lake
depressions within the glacial deposits is connected with these times. About 40000 yr BP,
a surface stabilization occurred, and syncryogenic deposits with thick polygonal ice wedges
(Ice Complexes) and peat beds were formed. Subsequent warming phases, apparently
connected with increases in precipitation, led to a new activation of glacier ice decay, and to
the accumulation of additional lacustrine and fluvio-lacustrine sediments. Palynological and
stable isotope data from ground ice suggest a continual trend to a cooler and more
continental climate from the Kargin Interstadial to the Sartan stadial times. During the
maximal cooling period, polygonal ice wedges in dried-up lacustrine deposits formed. At
the termination of the Pleistocene, lacustrine sedimentation seems to have reactivated in
reaction to short climate improvements. Thermokarst lakes were formed in this period.
Extensive peat accumulation started at the end of the Boreal and spread to flat lacustrine
depressions during the Atlantic. Since the Subboreal, a drying up of lakes and gradual
increasing of permafrost aggradation can be inferred.
Introduction
Controversy exists concerning both the extent and the age of the last glaciation in Central
Siberia. In particular, the environmental conditions during Post-Zyryan (Post-EarlyWeichselian) times are only slowly becoming clear (Astakhov, 1992; Faustova and Velichko,
1992; Isaeva and Kind, 1989; Velichko, 1993). The solution to these problems is quite
important as it would affect, firstly, the character of atmospheric circulation models during the
Late Pleistocene, and secondly, specific features of sediment transport to the Arctic Ocean.
Paleogeographical studies of permafrost sequences have been carried out in the Labaz Lake
region as part of the German-Russian research project "Taymyr" during two expeditions
(Siegert et ai., 1995; Siegert et ai., 1996). The study area represents the typical lowland
surrounding the Laptev Sea to the southwest. According to the maximal-extent reconstruction
of the Late Weichselian (Sartan) glaciation, this area was located to the east of the glaciated
territory (Velichko, 1993). Based on remote sensing and the study of sediment sequences in
surrounding river valleys, Isaeva (1982) assumed that the Late Pleistocene section at Labaz
Lake included deposits of a vast ice-dammed lake ("Pre-Labaz") that existed during the Sartan
glaciation. According to this interpretation, the level of the "Pre-Labaz" had reached a maximum
In: Kassens, H., H.A. Bauch, I. Dmitrenko, H. Eicken, H.-W. Hubberten, M. Melles, J. Thiede and L. Timokhov (eds.)
Land-Ocean Systems in the Siberian Arctic: Dynamics and History. Springer-Verlag, Berlin, 1999,477-499.