-They are  crescent-shaped features that are formed when meanders become so pronounced that they are cut off from the main river. -They are usually temporary features. -Over time, they may be filled up with sediments and vegetation, and become dried up.

With constant erosion of the concave bank and deposition on the convex bank, a meander becomes very sharp and pronounced, separated by a narrow neck of land.

The neck becomes narrower with continued erosion and deposition.

The river breaks through the narrow neck and flows straight through the channel. Over time, deposition begins to cut the river form the meander.

Eventually, the meander that is cut off forms an oxbow lake.

Examples of Oxbow Lakes in the World