How are truncated spurs formed by glaciers?
When a glacier moves downhill it erodes everything in its path through abrasion and plucking. Glaciers usually follow the easiest route down a mountain, which is often an old river valley. Interlocking spurs created by a river are eroded at the ends by the glacier to create truncated spurs .
What is truncated spurs geography?
Definition: Truncated spurs are landforms that occur in glaciated areas. When a valley fills with a glacier, any land which is in the way of the moving glacier will be eroded away. Truncated spurs have steep sides which show this erosion. This erosion can also be caused by moving water. Truncated Spurs.
Why truncated spurs & U-shaped valleys are evidence for glaciation?
Valley features. U-shaped valleys have steep sides and a wide, flat floor. During glaciation the smaller side valley contains less ice than the main glacial valley, which is why it is not as deeply eroded. Truncated spurs are rounded areas of land which have been cut off.
What are the main features of glacial erosion?
8 Main Features Created by Glacial Erosion | Geology
- Feature # 2. Glacial Striations:
- Feature # 3. Rock Drumlins:
- Feature # 4. U-shaped Valley:
- Feature # 5. Hanging Valleys:
- Feature # 6. Facets and Canals:
- Feature # 7. Fiords:
- Feature # 8. Roche Moutonne’e:
How are interlocking spurs formed?
As the river erodes the landscape in the upper course, it winds and bends to avoid areas of hard rock. This creates interlocking spurs, which look a bit like the interlocking parts of a zip. When a river runs over alternating layers of hard and soft rock, rapids and waterfalls may form.
What causes a hanging valley?
Thus, hanging valleys are formed as a result of the erosion effects due to glaciation. Research says that the valleys are formed because of two different glaciers. These glaciers interact with each other and ultimately lead to the process of the formation of hanging valleys.
What does a truncated spur look like on a map?
Spotting truncated spurs on OS maps involves looking at the sides of a U-Shaped Valley and identifying particulalry steep (contours closely packed together), rounded areas often marked by the black lines which symbolise cliffs / exposed rock faces.
Why are the valleys formed by glaciers U-shaped?
As glaciers flow through these valleys, they concentrate erosive action over the entire valley, widening its floor and over-steepening its walls. After the glacier retreats, it leaves behind a flat-bottomed, steep-walled U-shaped valley.
Where are truncated Spurs found?
Truncated spurs can be found within mountain ranges, along the walls of river valleys, or along coastlines. A faceted spur is also a spur that ends in a triangular face, known as a triangular facet, with a broad base and an apex pointing upward.
Is a interlocking spurs erosion or deposition?
While similar in general appearance, the mechanism behind the formation of interlocking spurs is different from that behind meanders, which arise out of a combination of lateral erosion and deposition. Interlocking spurs are formed as either a river or stream cuts its valley into local bedrock.
Where are interlocking spurs located?
upper course
Interlocking spurs are projections of high land that alternate from either side of a V-shaped valley. They are formed by fluvial erosion and are found in the upper course of a river where rocks are hard. Formed when the river is small and has less erosive power.
What is a truncated spur?
Truncated spurs (aka “spurs”) are features at the ends of arêtes where the rock is eroded into steep triangle-shaped cliffs by the glacier in the main valley. Figure 17.19 A diagram of some of the important alpine-glaciation erosion features.
What are interlocking spurs in a glacier?
These are called interlocking spurs. As a glacier moves downhill, the glacier cuts through these ridges, eroding them and leaving behind truncated spurs. Glaciers cut distinctive U-shaped valleys with a flat floor and steep sides.
How are River valley Spurs cut back?
Spurs that projecting into the original river valley are cut short, their lower ends being destroyed by the moving ice. They may be cut back right to the edges of the new valley, or still project slightly into the valley. This shortens the spurs, or truncates them.
How do glaciers affect the landscape?
When a river erodes the landscape, ridges of land form in its upper course which jut into the river. These are called interlocking spurs. As a glacier moves downhill, the glacier cuts through these ridges, eroding them and leaving behind truncated spurs. Glaciers cut distinctive U-shaped valleys with a flat floor and steep sides.