Graywacke, also known as wacke, is a type of sandstone that is composed of sand mixed with mud. It forms in deep ocean waters through turbidity currents and submarine landslides that rapidly transport sediment short distances. Graywacke contains a higher percentage of clay and less rounded grains than typical sandstone. It displays graded bedding from larger grains settling out first during deposition from turbidity events. Fossils can occasionally be found that provide clues about the depositional environment.