Extreme U-bend in a stream, usually occurring in a series, that is caused by flow characteristics of the water. Meanders form in stream-deposited sediments and may stack up upstream of an obstruction, resulting in a gooseneck or extremely bowed meander. A cutoff may form through the gooseneck and allow the former meander bend to be sealed off as an oxbow lake. Silt deposits may eventually fill the lake to form a marsh or a meander scar.

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