New results of lithological structural and textural observations and petrographic study of rocks of the Uryuk formation exposed in the basin of the Maly Tolpar River in the Bashkir meganticlinory are presented. For the first time, a wide development of consedimentary underwater landslide folds in the Uryuk deposits has been established, the sizes of which vary from the first tens of centimeters to the first meters. In sandstones, the presence of oblique, wavy, flasery and horizontal, with a dual character of thin clay layers, layering, as well as structureless layers with a massive texture, is recorded. Signs of shallow wave ripples have been established. Mechanoglyphs and textures similar to Arumberia banksi have been found, which presumably represent the lithified structures of bacterial mats that existed under certain conditions – shallow-sea environments and conditions of sandy-clay sedimentation. It is concluded that the Uryuk deposits, despite the absence of direct lithological signs of diamictites in them, form a single sedimentary sequence with the underlying Tolparov-Suirovsky marine glacial deposits, in which a shallow-sea sedimentation regime is established by the end of the Uryuk time. It is shown that the presence of ferruginous minerals in sandstone cement is secondary in nature and is associated with their epigenetic transformations. It is concluded that the red-colored color of the rocks of the Uryuk formation cannot be used for stratification of its sections and reconstruction of sedimentation conditions in the Uryuk time.