Question

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

Short answer

The correct answer is D) dune.

Step-by-step solution

Understand the Question

We need to identify which term represents a landform that's created by the process of deposition. This involves materials being added to a landform from a source, like wind, water, or ice.

Analyze the Options

Let's look at each option: - **A) Cirque**: A cirque is a bowl-shaped depression formed by glaciation, primarily through erosion, not deposition. - **B) Abrasion**: Abrasion is a process where rocks are worn down by friction, typically involving erosion. - **C) Striation**: Striations are scratches or gouges cut into bedrock by glacial abrasion, another erosional feature. - **D) Dune**: A dune is a mound or ridge of sand or other loose sediment formed by the wind, accumulating through the process of deposition.

Identify the Correct Answer

By analyzing the options, we can see that a dune is formed by the accumulation of sediments deposited by wind, fitting the criteria of a feature created by deposition.

Key concepts

Dune formation

Dune formation is a fascinating process that creates these natural features commonly found in deserts and along coastlines. Dunes are formed as the wind moves loose sand or other sediments, gradually depositing them in mounds or ridges when the wind’s energy decreases. The entire process relies on the interaction between wind, sand supply, terrain, and existing vegetation, resulting in a wide variety of dune shapes and sizes.

• The most common type of dune is a **crescent dune**, or barchan, which forms where the wind direction is steady.
• **Parabolic dunes** tend to form in areas with partial vegetation cover.
• **Star dunes**, complex structures, form where winds come from multiple directions.

These formations are dynamic and can move over time, continuously changing shape as they are influenced by the persistent force of the wind.

Glacial erosion

Glacial erosion is a powerful natural process that shapes landscapes in regions with glaciers. This process is characterized by the movement of large masses of ice across the land, scraping and sculpting the terrain as they advance. This phenomenon results in a range of erosional features.

• **U-shaped valleys** are carved out as glaciers travel down pre-existing river valleys, transforming them from V-shaped to broader, U-shaped ones.
• **Cirques** are bowl-shaped hollows found on mountainsides where glacier ice has eroded the surface.
• **Arêtes** and **horns** are sharp ridges and peaks formed by the eroding action of multiple glaciers converging.

These striking landforms demonstrate the immense power of glacial erosion in shaping our planet's surface.

Wind deposition

Wind deposition occurs when wind transports fine particles of sediment from one place and deposits them in another. This process is crucial in forming new land features, particularly in arid or semi-arid regions where loose material is abundant. As the wind loses its velocity, it drops the sediment it carries, leading to the creation of various landforms.

• **Dunes** are the most prominent features created through wind deposition.
• **Loess deposits** are formed from fine silt particles that create fertile soils in some regions.
• In coastal areas, **sand spits** and **bars** develop as wind moves sand from shoreline sources.

Wind deposition illustrates how this natural force not only shapes existing landscapes but also creates new ones by adding layers of sediment.

Landform processes

Landform processes refer to the natural phenomena that lead to the formation and alteration of the Earth's surface features. These processes are primarily driven by the energy from the sun, gravitational forces, and the movement of tectonic plates. They can be broadly classified into three main types: erosion, deposition, and tectonic activity.

• **Erosion** involves the wearing away of Earth's surface by wind, water, ice, or biological activity, shaping features like valleys, canyons, and coastal cliffs.
• **Deposition** is the process of accumulation or laying down of sediment, leading to the formation of landforms such as deltas, floodplains, and sand dunes.
• **Tectonic activity** results in the creation of features like mountains, earthquakes, and volcanoes as continental and oceanic plates move over time.

Understanding these processes helps us appreciate the dynamic and ever-changing nature of our planet's surface.