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A cut bank, also known as a river cliff or river-cut cliff, is the outside bank of a curve (meander) in a water channel (stream), which is continually undergoing erosion. [1] Cut banks are found in abundance along mature or meandering streams, they are located opposite the slip-off slope on the inside of the stream meander.
The lowest unit, 175-180 feet thick, is characterized by many beds of bentonite, calcareous concretions, and concretionary limestone. The middle unit, about 200 feet thick, is characterized by numerous beds of reddish-weathering ferruginous concretions and concretionary limestone and dolostone.
- Introduction
- What Are Streams?
- Drainage Area
- Stream Order
- Drainage Patterns
- Graded Profile
- Stream Discharge
- Sediment Load
- Floodplains
- Flooding and Flood Frequency
Streams have a major role in geology. Streams sculpt and shape the earth’s surface by eroding, transporting, and depositing sediment. By eroding sediment from uplifted areas and creating landforms made of deposited sediment in lower areas, streams shape the earth’s surface more than glaciers do, more than waves on a beach do, and far more than wind...
A stream is flow of water, driven by gravity, in a natural channel, on land. A small brook in a meadow and the Amazon River are both streams. It is interesting to watch water on a recently bulldozed construction site with a slope. At first the water saturates the ground and begins to flow downhill across the surface of the slope in a thin sheet. So...
The drainage area of a stream encompasses all the land from which surface runoff flows into that stream. A stream drainage area is also called a watershed. Boundaries between stream drainage areas are called drainage divides. What stream drainage do you live in?
It is common for one stream to flow into another. The smaller of the two streams is a tributary of the larger stream. A stream with no tributaries is a first order stream. A stream with only first-order tributaries is a second order stream. A stream that has any second-order tributaries and none higher is a third-order stream, and so on. The Missis...
A stream system that includes multiple tributaries exhibits a distinct drainage pattern as seen on a map. The drainage pattern depends on the rock types and geologic structures underlying the stream system. Some types of rock are harder and more resistant to erosion than others. If the geology underlying a stream system is fairly uniform—rocks equa...
Because streams erode more and remove more sediment where the stream gradient is higher, and deposit more sediment where the stream gradient is lower, a stream will develop a graded profile as shown. The graded profile shows how the elevation of the stream changes along the length of the stream, from its beginning at the highest elevation to its ba...
The amount of water flowing through a stream and speed at which it is moving is expressed as the discharge of the stream. Discharge is measured by multiplying the cross-sectional area of a stream by the average speed of water through that cross-section. Multiplying the area of the cross-section by the average speed of the water results in units of ...
The water flowing in streams erodes, transports, and deposits sediment. Most rocks and minerals are much denser than water. Sufficient energy in the stream is required to dislodge rocks from the earth and move them. The faster a stream flows, the more energy it has and the larger pieces of sediment it can transport. The competenceof a stream refers...
Streams build floodplains through a combination of erosion and deposition at lower gradient stretches of stream valleys. Although a floodplain has a general downhill slope consistent with the overall stream gradient, a floodplain is relatively flat. Floodplains are filled with sediments spread by the stream. These sediments are known as alluvium. B...
Streams flood. Flooding is a normal part of stream behavior. The rate at which streams erode, transport, and deposit sediments greatly increases during flooding. A flood occurs when the water depth in a stream exceeds the depth of the stream channel and spreads beyond the stream channel onto the surrounding land. When a stream completely fills its ...
A point bar is an area of deposition where as a cut bank is an area of erosion. Point bars are formed as the secondary flow of the stream sweeps and rolls sand, gravel and small stones laterally across the floor of the stream and up the shallow sloping floor of the point bar.
A bar in a river is an elevated region of sediment (such as sand or gravel) that has been deposited by the flow. Types of bars include mid-channel bars (also called braid bars and common in braided rivers), point bars (common in meandering rivers), and mouth bars (common in river deltas).
Dive into stream erosion 101 with Welty as we discover Point Bars and Cut Banks! We will walk along Turtle Creek and see real examples of these geological features, then we will create some of...
- 10 min
- 3.5K
- Welty Environmental Center
Dec 26, 2021 · On the outer, or concave, side of the meander bend is a steep bank or cliff, often called a cut bank, of consolidated or semiconsolidated sediment that is eroded during strong flows. The bank is eroded by various processes, the most important of which is undercutting low on the bank and collapse of large masses into the channel.
