"On occasion, we find within w:Sedimentary rocksedimentary rock “ephemeral markings” - these are imprints/impressions that are made in mud and or sand that is rapidly hardened into stone with the impressions still in tact. Such ephemeral markings are also known as “trace fossils” or “ichnofossils”. These can include things like bird tracks or wave ripples or other types of evidence of movement that would normally be left within a soft surface. This usually occurs through some form of flood catastrophe (usually the laying down of a lot of water rapidly)"