MAIN STAGES AND PALEOGEOGRAPHY OF CENOZOIC SEDIMENTATION IN THE BAIKAL RIFT SYSTEM (EASTERN SIBERIA)

The stratigraphy, sedimentology and palaeogeography of the Cenozoic fi lling of the basins in the Eastern Siberia rift system are described. A regional scheme for the stratigraphy of the Cenozoic sediments is pr oposed with special attention being paid to the processes of ancient w eathering. The sedimentation is divided into stages which differ in te ctonic pattern and climatic conditions. At the Late Cretaceous - Early Paleocene boundary, lateritic weathering residues were developing in the Sayan-Baikal highlands, in a stable tectonic environment under a w arm moist climate. During the second stage, through most of the Paleog ene and Early Neogene, a coal-bearing molasse accumulated. The third s tage covers the deep-lake sedimentation in the Baikal and Khubsugul ba sins, which began in the Pliocene and is continuing at present.