Home – Home – Jornals – Russian Geology and Geophysics 2001 number 1-2

Rock-magnetic and granulometric studies were conducted on the BDP-93 cores (100 m in length) obtained from the Bugul'deika saddle of Lake Baikal, southeastern Siberia. The remanent magnetization of the cores shows dominant positive inclination, indicating that the cores are included in Brunhes normal chron ( 780 ka BP). Some geomagnetic excursions were found in both cores. With the age scale referred to ¹⁴C dates and regeression, they are estimated to be 100 and 120 ka BP (Blake event), 310 and 340 ka BP (Calabrian ridge, event 1). These geomagnetic events possibly include double excursions. Comparison of magnetic properties with the content of diatoms and biogenic SiO₂ shows a low concentration of magnetic minerals during interglacial periods and a high concentration during glacial periods. However, this relation is obscure at the lower 60 meters of the core. Rock-magnetic and other parameters suggest a change in sedimentation environment at a depth of 40 m, which may be related to a shift of the sedimentary source. These results suggest that the sedimentation environment of the Bugul'deika saddle was influenced by the local sedimentation conditions.