Debris-flow sediments belonging to the Upper Cieszyn Limestone (Berriasian) are exposed near Żywiec (Polish part of the Outer Western Carpathians). The debris-flow sediments include clasts of bioclastic limestones (boundstones) derived from both microbial-sponge mud mounds and coral-algal reefs. The microencruster assemblage Lithocodium aggregatum–Bacinella irregularis has been found in clasts from coral-algal reefs. This assemblage unequivocally proves the presence of shallowing-upward reefal sequences on the Silesian Ridge. The development of the coral-algal reefs was probably a consequence of intense aggradational growth of microbolite-sponge mud mounds, accompanied by intense uplift movements of the neo-Cimmerian phase.