Small lake located in a former meander loop of a river or stream channel. It is generally formed as a river cuts through a meander neck to shorten its course, blocks off the old channel, and then migrates away from the lake. If only one loop is cut off, the lake is crescent-shaped; if more than one loop is cut off, the lake is serpentine (winding). Eventually, oxbow lakes silt up to form marshes and finally meander scars.

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