The paper describes data of analysis of the uppermost (8 to 14 m) laye
r of bottom sediments of Lake Baikal sampled by tube corers on the top
of the underwater Akademichesky Ridge at three sites separated by lar
ge distances (30 km). The cores were subjected to primary lithological
description, photography on color film and X-ray fluorography. Sample
s taken at 10 cm intervals were analyzed for the content of water, opa
l silica, organic carbon, total uranium, molybdenum, and 14 other elem
ents. Quantitative diatom analysis was done at frequency of 2-10 cm us
ing light microscopy. Scanning electron microscopy was applied to ensu
re correct identification of some diatom species. Pollen grains and sp
onge spicules were also identified and counted. A section of one of th
e cores was subjected to paleomagnetic measurements and a magnetic exc
ursion was found. The three cores perfectly correlate with each other
exhibiting cyclic changes of the content of opal silica and diatom fru
stules. A new method of thorium-uranium dating was applied to data on
the activities of uranium series isotopes obtained by Egdington et al.
(1994) and showed that the age of one of core is ca. 100,000 years. T
he cores correlated with each perfectly correlate other in all paramet
ers, quiet continuous sedimentation. The oceanic stages of warm climat
es (stages 1, 3, 5) seem to correspond to diatom-rich layers in the Ba
ikalian cores, while the stages of global glaciation (stages 2 and 4)
correspond to the beds having no diatoms. The content of diatoms, biog
enic silica, and organic carbon positively correlated with U and Mo. T
he profile of the content of diatoms taken at a 2-cm frequency for one
of the cores suggests that the paleoclimates of East Siberia were sub
jected to abrupt and dramatic changes similar to which were found by G
. Bond et al. (1993) for the same time interval for North Atlantic. Ty
pical times of appearance and disappearance of some species off diatom
s are small (100-500 years). The paleoclimate record documented in sed
iments of the Akademichesky Ridge completely satisfies the requirement
s of international programs in terms of temporal resolution.