This is a diagram illustrating how oxbow lakes are formed. The process begins with a meander, which is a winding curve in a river. Over a long period of time, the narrow “neck” of the meander is eroded by the river current until it has been completely cut through. The water will then run through the new, straight channel instead of the old meander. As more time passes, silt will accumulate on the banks of the river, slowly sealing off the meander until only an oxbow lake remains. I think this picture is very educational and informative