The data presented introduce substantial changes into Quaternary stratigraphy, paleogeography, and the geological history of the Altai Mountains. The purpose of this investigation was thorough study of block accumulations in the Chuya and Katun river valleys. The new data shed light on the structure of these deposits, their composition, the geomorphological and stratigraphic position, and the morphology of blocks. The revealed morphological features of individual blocks imply their glacial origin.
