Climato-limnological signals during the past 260 000 years in physical properties of bottom sediments from Lake Baikal

The St.16 core obtained from the Academician Ridge of Lake Baikal in easter n Siberia may span about 260 000 years, and some physical properties of the core samples are closely related to aquatic paleoproductivity and climatic change. The median of grain size, grain density, and water content fluctua te synchronously. They also are connected with change in the abundance of b iogenic silica (diatoms). The physical parameters indicate that there were high aquatic productivity periods around 'interglacial' periods (MIS 5 and 7; 70 000-125 000 yr B.P. and 180 000-250 000 yr B.P.). Comparatively large clastics were transported from outside of the lake through various routes (ice rafting, etc.) in addition to fluvial routes during the 'glacials' or 'stadials'. There are ca. 20 000 yr, 40 000 yr and 100 000 yr periods in th e variations of physical properties. These are related to the three Milanko vitch parameters of solar insolation insolation.