Paleomagnetic measurements on sediment core BDP-1-A (BDP93-1).

We made magnetic measurement of 32 cubic specimens of sub-bottom sediments of Lake Baikal. These are part of the sub-samples for palaeomagnetic investigations obtained from the sediment cores from hole 1 of Baikal Drilling Project (BDP). This hole was drilled to the depth of about 100 m below the lake bottom. Our samples are almost evenly spaced with the average interval of 2 m in the drilled section. The sedimentation rate at the drilling site on the Buguldeika has been estimated relatively low. Our prime interest was therefore to investigate whether or not the BDP-1 cores penetrate the Brunhes/Matuyama boundary dated at 0.78 Ma (Shackleton et al.,1990). Initially, we measured natural remanent magnetization (NRM) of all the specimens, using a flux-gate spinner magnetometer (Natsuhara Giken, SMD-88). The intensity of NRM ranges between 2.2x10^-3 to 70.7x10^-3 A/m, which is sufficiently higher than the background noise level of our spinner magnetometer.