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Raw pollen data from the Eemian core CON01-603-2

The studied core CON01-603-2 was recovered from the Continent site, Northern Basin from a water depth of 386 m (Fig. 1) (see Charlet et al., 2005-this volume). The analysed sequence (725.5–608 cm) consists of mainly of biogenic, diatomaceous sediments, although the upper part of the sequence between ca. 611–608 cm contains more silt particles and less diatoms than the lower part of the sequence. From a depth of 690 cm upwards the sediments are finely and coarsely laminated.Based on a standard technique for processing palynological samples, silicates were removed from the sediment by treatment with 40% HF for 3 days and with 50% HF for 1 day. Following Erdtmans acetolysis (Faegri and Iversen, 1989) sediment samples were sieved through 7-µm meshes in an ultrasonic water bath (Cwynar et al., 1979).

Downcore variations of the opal content for the sedimentary sequence of VER98-1-14

Opal content was obtained by measuring the NaCO3 leached solution by inductive coupled plasma with an optical emission spectrometer (ICP-OES). The clay-rich layers are characterised by a low level of opal content. The diatomaceous layers are characterised by a high level of opal content.

Raw pollen data from kasten core CON01-603-5 part2 (counts)

Sediment slices of 0.5 cm thickness were obtained from gravity core segments and of 1 cm thickness from the Vydrino piston core. Volumetric subsamples of 5 cm3 (10 cm3 in case of the lowermost samples from Continent core) were prepared according to standard procedures, including 7-μm ultrasonic fine-sieving (Cwynar et al., 1979, Fægri et al., 1989 K. Fægri, P.E. Kaland and K. Krzywinski, Textbook of Pollen Analysis (4th edition), John Wiley & Sons, Chichester (1989) 328 pp..Fægri et al., 1989 and PALE Steering Committee, 1994). Two tablets of Lycopodium marker spores were added to each sample for calculating total pollen and spore concentrations (Stockmarr, 1971). Water-free glycerol was used for storage and preparation of microscopic slides. The palynological samples were counted at magnifications of 400–600×, applying 1000× for the identification of difficult pollen types, e.g., including Saxifragaceae, Crassulaceae, and Rosaceae.

Age models based on palaeomagnetic measurements for the two cores analysed, CON01-603-2 (Continent Ridge) and VER98-1-14 (Academician Ridge) showing the correlation points to the reference record

Palaeomagnetism was the method used for dating sediments older than the time span covered by AMS 14C dating. Geomagnetic palaeointensities recorded in Lake Baikal sediments were tuned to a reference curve (the record from ODP Site 984, Channell, 1999) whose chronology is well constrained (Demory et al., 2005a-this volume and Demory et al., 2005b-this volume). The palaeointensity record from ODP Site 984 is of high quality, is well dated and covers the time span of the present study. Anchored by a geomagnetic excursion (the Iceland basin event, dated at 186–189 ka according to Channell et al. (1997)), this age model is constrained by 55 correlation points for a time span of ca. 200 ky. The age models for both core sections in the interval 100–150 ky are shown in Fig. 2.

Down-core variations of the inclination and declination of ChRM of all investigated cores.

Dashed lines mark some correlation levels of the cores from Lake Baikal with the dated δ18O record from ODP 677 (Shackleton et al., 1990), see also Fig. 3. Diagenetic features such as dissolution of magnetite and mineralization of greigite are marked according to Fig. 4. Laschamp and Iceland Basin excursions are indicated as La. and Ic., respectively. Inclination and declination records could provide information on paleosecular variations (periodicity ≤105 years and directional variability <20°, according to Butler, 1992). In the present study, we did not interpret inclination and declination records in terms of paleosecular variations since slight sediment disturbances could produce slight deviations of ChRM declinations and inclinations. (see Fig.7)

Inclination, declination and the reversal angle of the ChRM for CON01-603-2

Selected intervals of down-core variations of normalised relative paleointensity, ChRM inclination and declination, and the reversal angle. (A) Core CON 01-603-2: numbers in the simplified lithological column indicate marine isotope stages (MIS), after Fig. 3. The paleomagnetic data show a geomagnetic excursion with a short, but full, reversal of the local field vector at the beginning of MIS 6. (B) Core VER 98-1-1: in this case, the excursion represented by a strong deviation of the reversal angle during a period of low intensity occurs in MIS 3 and corresponds to the Laschamp event. (C) Core VER 98-1-1: in this case, the excursion is also represented by a strong deviation of the reversal angle during a period of low intensity. Again this occurs in MIS 3 and corresponds to the Laschamp event.

%dry weight and %loss on ignition for CON01-603-5

Water content and dry bulk density of pilot core to CON01-603-2, PANGAEA

Water content and dry bulk density of pilot core to CON01-603-2

Wet bulk density (GRAPE) of piston core CON01-604-2 from Posolskoe, PANGAEA

Wet bulk density (GRAPE) of piston core CON01-604-2 from Posolskoe

Vertical distribution in the sediment of the different animal groups found in station CON01-433 (Vydrino Shoulder) in the abyssal zone of Lake Baikal, expressed as the number of individuals per m2.

The vertical distribution of organisms in the sediment indicates that animals can be present as deep as 15 cm although at very low abundance at such depths (Fig. 4, Fig. 5 and Fig. 6). Oligochaetes and nematods are the only groups able to deeply penetrate into the sediment at significant densities (Fig. 4) in contrast to all other groups, which stay closer to the sediment surface. Maximal densities however seem to shift to the sediment surface with increasing bathymetric depth, as suggested in Fig. 5 and Fig. 6, so that all animal groups are more concentrated near the surface in the deepest parts of Lake Baikal. In such case, the depth of sediment mixing due to bioturbation appears to decrease with increasing bathymetric depth (Fig. 2b).

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