Home – Home – Jornals – Russian Geology and Geophysics 2002 number 2

New data prove that the rise of the Baikal level in the past (to 120-150 m) may have really occurred and was caused by tectonic uplift of the western side of the Baikal basin. As the lake level rose, medium and high terraces were forming and sands deposited in the Selenga delta and elsewhere; the discharge through the Lena along the paleo-Manzurka valley (2.0-0.5 Ma ago) was blocked, and a new outlet appeared through the Il'cha-Irkut valley into the Yenisei system (0.5-0.6 Ma ago). That outlet was broken about 60 ka ago by the collapse of the Listvyanka block, which at the same time produced the present-day discharge channel through the Angara. Calculations show that the lake level may hardly have dropped for a geologically long time, but short episodes of low stand were possible. The terraces on the lake sides result from the joint effect of tectonic and hydrological factors. Analysis of the past evolution of the river network in the Western Baikal region allowed prediction of its possible changes in the future.