The oldest sediments exposed in the southern sea cliffs of Bolshoy Lyakhovsky Island consist of a layer of rocky, yellowish to greenish colored sediment. This layer is a thick Paleogene weathering crust (paleosol) that has developed within Permian sandstone. This paleosol has been largely modified by periglacial processes and development of ice wedges periodically during the Pleistocene. These deeply weathered sediments are unfossiliferous and characterized by the presence of weathering products like kaolinite and montmorillonite. Saalian sediments uncomfortably overlie this paleosol.
