Paleogeography and Quaternary terrace sediments and complexes, intermontane basins of Prebaikalia (Southeastern Siberia, Russia)

Several large lake stages, interspersed by cycles with low water levels and exposed areas with erosion are recorded in Prebaikalia depressions from the Upper Eopleistocene. Neotectonic activities were responsible for water-level changes and ingression of lake waters into river valleys. At the end of the Eopleistocene, the lake-regime was transformed, and finally replaced by a river. Two blocks of different elevation, associated with sediment aggregates of the upper (VII-IV) and low (III-I) terraces can be distinguished in the terrace complex. The upper terraces were formed in a limnic environment, and the lower terraces formed in a prevailing river environment with subordinate lacustrine conditions.