Cut bank (geology)

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A cut bank is an erosional feature of streams. Cut banks are found in abundance along mature or meandering streams, they are located on the outside of a stream bend, known as a meander. They are shaped much like a small cliff, and are formed by the erosion of soil as the stream collides with the river bank. As opposed to a point bar, it is an area of erosion rather than deposition.

Typically, cut banks are nearly vertical and often expose the roots of nearby plant life. Often, particularly during periods of high rainfall and higher-than average water levels, trees and poorly placed buildings can fall into the stream due to mass wasting events. Given enough time, the combination of erosion along cut banks and deposition along point bars can lead to the formation of an oxbow lake.

Not only are cut banks steep and unstable, they are also the area of a stream where the water is flowing the fastest and the deepest, making them rather dangerous. Geologically speaking, this is known as an area of high-energy.

Material eroded here is deposited downstream in point bars.

[edit] References

Tarbuck, E. J. and F. K. Lutgens. Earth, 7th Edition. Prentice Hall: Upper Saddle River, New Jersey, 2002. pp. 279, 286.