Step-by-step explanation:
when a meander becomes very pronounced,the outside bend or concave bend is so rapidly eroded that the river cuts through the narrow neck of the loop, forming an ox-bow lake or 'mortlake' (meaning dead lake). the river then flows straight. the ox-bow lake will later degenerate into a swamp through subsequent floods that may silt up the lake. it becomes marshy and eventually dries up.