Question

Which term is an example of a feature created by deposition? A) cirque C) striation B) abrasion D) dune

Short answer

Dune (Option D) is a feature formed by deposition.

Step-by-step solution

Understanding the Question

We need to identify which of the given terms represents a geological feature that is formed by the process of deposition. Deposition occurs when materials are added to a landform.

Analyzing the Options

1. Cirque - A bowl-shaped depression carved by a glacier; formed by erosion, not deposition. 2. Striation - Scratches left on rocks by glacial movement; also a result of erosion. 3. Abrasion - The process of wearing down surfaces by friction; not a feature but an erosive process. 4. Dune - A mound or ridge formed by the deposition of sand by wind action.

Identifying the Correct Term

From the analysis, a dune is the only feature among the options that is directly formed by deposition as it involves the accumulation of sand or other materials by the action of wind.

Key concepts

Deposition

Deposition is an important geological process where materials are naturally laid down or settled in a new location. This occurs when the forces carrying those materials, like water, wind, or glaciers, lose energy and can no longer transport them. As a result, these particles settle out of the air or water and accumulate, adding to or building up landforms.
One classic example of deposition is the formation of dunes. Dunes are created when wind accumulates and deposits sand particles in one area. Over time, these sand particles build up to form mounds or ridges. This is common in deserts or coastal areas where constant wind movement is present. Another example is the formation of river deltas, where sediment carried by rivers is deposited at the mouth, forming new land.

• Deposition is crucial in forming new geological features and landscapes.
• It involves the accumulation of solids like sands, silts, and clays.
• Factors influencing deposition include the speed of water or wind and the size of particles.

Erosion

Erosion is the process by which the surface of the Earth gets worn down. It involves the breaking down and removal of rock and soil from one place to another. Erosion can occur via natural forces such as water, wind, ice, or even human activities.
This process is responsible for many of the landforms we see today, including valleys, canyons, and riverbanks. Rivers and streams can erode their banks, glaciers can carve out landscapes, and wind can reshape sand dunes. With time, these processes can create significant changes in the landscape.

• Erosion is important for shaping the Earth's surface.
• It involves both the physical breaking down and transport of materials.
• It can be accelerated by human activities like deforestation.

Glacial Features

Glacial features are landforms created and altered by the action of glaciers, which are large masses of ice that move slowly over land. These features take shape as glaciers advance, erode, transport, and deposit materials.
One well-known glacial feature is a cirque, a bowl-shaped depression found on the side of mountains, formed by the erosive action of glaciers. This process often starts with freeze-thaw action, weathering the rock and leaving a hollow behind once the glacier melts.

• Glacial features are key indicators of past climates.
• They are often formed by erosion and deposition together.
• Such features can include moraines, fjords, and drumlins.

Wind Action

Wind action describes the processes in which wind shapes the Earth's surface. It plays a significant role in erosion, transportation, and deposition of materials, especially in arid and coastal regions.
One of the most prominent features resulting from wind action is a sand dune. Dunes form as wind picks up loose sand and moves it to another location, where it deposits and accumulates to create mounds or ridges. The shape and size of dunes can vary greatly, influenced by factors like wind speed, direction, and the availability of sand.

• Wind action can transport fine particles through processes like deflation and saltation.
• It leads to the creation of unique landforms such as loess deposits and sandstone arches.
• Environmental factors like vegetation can impact wind erosion and deposition.