A silicite horizon corresponding to the global catastrophic event at the Cretaceous–Paleogene boundary was found for the first time in the flysch sequence of the Shapsug section on the southern slope of the Northwest Caucasus. Assemblages of radiolarians and planktonic foraminifers dating the host beds were identified. Mineralogical and analytical data support the presence of tectites, impact minerals, and increased iridium content in the boundary bed of the studied section. [ABSTRACT FROM AUTHOR]