MINERAL MAGNETIC AND PHYSICAL-PROPERTIES OF SURFICIAL SEDIMENTS AND ONSHORE SAMPLES FROM THE SOUTHERN BASIN OF LAKE BAIKAL, SIBERIA

Results of lithostratigraphic and mineral magnetic analysis of two sur ficial sediment cores (21 cm and 45 cm in length) collected from the S outhern basin of Lake Baikal at a water depth of 1390 m, are presented . The sediments have been measured for a wide range of mineral magneti c parameters in order to assess their value in the identification of t urbidite layers. Particle size and geochemical data are also presented and these explain some of the down core variations in magnetic minera logy. It is suggested that changes in the particle size frequency dist ributions down core may be related to fossil diatom shells. One of the cores has been dated using Pb-210. Th, sediment cores were cross-corr elated using low frequency magnetic susceptibility (chi lf) and these cores can also be correlated with a nearby core collected earlier in 1 992. Changes in the magnetic parameters of chi lf, IRMs and HLRM100 su ggest that there are significant changes in the concentration of ferri magnetic minerals in the sediment cores, indicating changing sediment sources and/or increasing concentrations of spheroidal carbonaceous pa rticles and the dissolution of minerals through reduction below the ox idised layer within the sediment core.