liustiku sulamisel jääst vabanenud setetest liustikuserva ette kujunevad liustikuservaga paralleelsed (marginaalsed) ja selle kuju jälgivad künnised, mille mõõtmed sõltuvad kujunemise aja kestusest ja sette hulgast liustikus, a winding ridge of unconsolidated debris (till) deposited at/in front of a glacier margin. They reflect the shape of the glacier terminus and the size depends on the length of it takes them to form. May be composed of debris ranging in size from silt-sized glacial flour to large boulders. Can be formed at the ice-sheet margins as well as in front of Alpine glaciers.