An overbank is an alluvial geological deposit consisting of sediment that has been deposited on the floodplain of a river or stream by flood waters that have broken through or overtopped the banks. The sediment is carried in suspension, and because it is carried outside of the main channel, away from faster flow, the sediment is typically fine-grained. An overbank deposit usually consists primarily of fine sand, silt and clay. Overbank deposits can be beneficial because they refresh valley soils. 
- Pyle, Robert Michael. "Overbank Deposits". Retrieved 21 October 2013.
- Collinson, J.D. 1986. Alluvial Sediments. In: H.G. Reading, editor, Sedimentary environments and facies, 2nd edition; Section 3.6: Inter-channel areas. Blackwell Scientific Publishing, Oxford; p. 41-43. ISBN 978-0-632-01223-7.