Estimation of the loss from the upper layer of sediments in the cores fromboreholes BDP-96-1 and BDP-96-2 (Lake Baikal)

Drilling on the Akademichesky Ridge of Lake Baikal (winter 1996) penetrated a section of lacustrine sediments, which spans 5 Ma. The stratigraphy and physical properties of the extracted cores are compared in detail with the cores which were extracted from the same sites of the bottom using piston a nd gravity corers. It has been established that the former cores lack a few meters of sediments. Carbon isotope dating with an accelerating mass spect rometer (AMS) shows that the core from BDP-96-2 lacks sediments formed in t he last 35 ka. The Blake excursion at a depth between 7 and 8 m of this cor e permitted us to estimate the time interval of sediments lost from the cor e from BDP-96-1, which spans 12 ka.