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Understanding Deposition in Geology with Examples

Understanding Deposition in Geology with Examples

The process of erosion is followed by deposition. Deposition refers to a process in which materials such as rocks and sediments settle down, giving rise to specific formations. This extract provides you with the definition of deposition with their examples in real life.
Prachi Patkar
Last Updated: Jan 16, 2018
Erosion is known to wear off sediments; thus, it seems to be destructive in nature. In contrast, the process of deposition displays a very constructive behavior in building various formations on the Earth.
To begin with, let us understand what deposition means in geography. Natural agents such as wind and water constantly act on the Earth's surface, thus eroding it. The eroded material is then transported to another location and deposited. This action results in the formation of various geological features. Wind and different forms of water such as rainwater or flowing water transport material such as sand, clay, boulders, or sediments. When these agents can no more bear the weight of these particles, they are dropped off.

We have already learned that deposition occurs after erosion. In case of deposition, the particles lodged are the ones that stop moving after losing their velocity. The velocity of these particles is decided by the velocity of the natural agents carrying it.

Consider some sand particles being carried by the wind. When the wind velocity reduces to an extent that it can no longer continue carrying the particles, it drops them. Similarly, if a flowing river stops or dries up, the sediments carried by it are dropped midway. The speed or velocity of these agents depends on many factors such as obstacles during its course. These obstacles may include rocks, boulders, hills, trees, etc.
Examples of Deposition of Sediments by Wind and Water
Sand Dunes
Sand Dune Deposition
The sand blown by wind deposits in the form of a hill or ridge. They are longer in length on the side of the wind. The depression between two dunes is called a slack.
  • Guadalupe-Nipomo Dunes located in San Francisco, United States.
  • Silver lake sand dunes located in Michigan, United States
Sand Ripples
Sand Ripples Deposition
They are formed by the action of wind or water and are shorter in length than sand dunes. They are either symmetrical or asymmetrical in nature.
  • Crescent-shaped rippled Barchans dunes in Afghanistan
  • Ripple formation on the North Carolina beach, Carolina
Sand Drift
Sand Drift Deposition
The sand gets drifted due to wind or water. This results in formations having varying shapes and sizes. The typical shapes include hummock, sand pile, or a knoll. They are smaller than sand dunes.
  • Drift at New Brighton in Canterbury, New Zealand
Beach
Beach Deposition
A landform formed along the coast of a water body such as an ocean is called a beach. The sand contained by the beach is deposited after the erosion of rocks and coral reefs.
  • The long stretch of Paradise Island beach, Bahamas
  • Mar del Plata beach, Buenos Aires , Argentina
Loess
Loess Deposition
The wind deposits sediments that possess a yellowish-gray color. These deposits are known to be having a high thickness and they create a wall-like structure called loess.
  • A loess structure formed in Vicksburg, Mississippi, United States
  • A loess plateau formed at Hunyuan, Shanxi Province, China
Floodplain
Floodplain Deposition
It is the area contiguous to a flowing water body such as a river, which receives plenty of water during high water levels.
  • ParanĂ¡ Delta is a floodplain in succession to the ParanĂ¡ River, Brazil
  • Maputo Special Reserve area in Mozambique, Africa
Levees
Levee Deposition
It is a landform that prevents water bodies from causing floods. It is naturally occurring or sometimes built by man-made processes to protect certain portions of land from floods.
  • A strip of dry land covered by the levee formed at Yangtze River, China
  • Levee at Sacramento (the city known for catastrophic flooding), Canada
Glacier
Glacier Deposition
At times, a water body flowing in cold regions freezes into ice. This is called a glacier. It contains a huge ice mass, which includes sediments as well.
  • Timpanogos Glacier located at Wasatch range of Utah, United States
  • Large glacier named Perito Moreno located in Western Patagonia, Argentina
Alluvial Fan
alluvial fan
It is a fan-shaped structure formed when water flows through hills or mountains. It is known to comprise sand, gravel, or other types of sediments.
  • An alluvial fan of a large size at Tibetan plateau, China
  • The alluvial fan formation found near Lake Louise, Alberta, Canada
Delta
Sacramento River Delta
This is a structure formed at the mouth of the water bodies such as a river. It is a result of deposition of alluvial sediments before the water plunges into a larger water body such as an ocean.
  • Delta formed by the Nile River while flowing to the Mediterranean Sea
  • Mississippi Delta formed by the river, Mississippi, United States
In the end, it should be understood that deposition is a continuous process. The materials deposited once may be eroded and deposited again, thus, forming a new structure. Besides this, the continual deposition of sediments results in the formation of rocks.