Geography also examines the problem of deposition. Another name for this deposition is known as sedimentation. Therefore this time portal-ilmu.com will discuss about the definition of sedimentation and the types of sedimentation. Where sedimentation itself is caused by many factors. Check out the explanation below.
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Definition of Sedimentation
Sedimentation is the process of deposition of rock material from erosion or erosion by water, wind, and glaciers. Material resulting from erosion is then transported by water flow and deposited in the lowlands, river mouths, the seabed and the coast or lake.
The form of erosion results in the form of sedimentary soil, alluvial plains, and delta plains.
Factors Causing Sedimentation
There are several factors that influence the occurrence of sedimentation, namely:
- There is a source of sediment material
- There is a suitable environment for sedimentation (whether on land, transition or sea)
- The occurrence of transportation by wind, ice and water to the source of material (transport)
- Differences in current or force cause deposition to take place
- There is a replacement (replacement) and recrystallization (change) material
- The process of diagenesis or changes that occur when deposition takes place chemically and physically.
- The compacting process, which is a result of the gravity of the sedimentary material which forces the volume of the sediment layer to decrease
- Lithification occurs due to continuous compaction so that the sediment becomes hard.
Type of Sedimentation
Various types of rocks which are the result of weathering and deposition are deposited. This will eventually turn into sedimentary rock. The results of this sedimentation can be different from one place to another. Based on the carrier, there are special characteristics of the landscape that occur due to the deposition process. The following characteristics:
- Sedimentation by River Water
The result of sedimentary rocks that occur due to water is aquatic sediment. Landscapes from the deposition by water for example: meanders, oxbow lakes, natural dykes, and deltas.
1 # Meander
Meander is a type of river that has a distinctive winding shape. This form occurs due to the deposition. The winding process that occurs in this river starts from the river in the upper reaches. Whereas in the upstream part, the volume of river water is small and the energy generated is also small. Because of this, the river began to avoid obstacles to find the easiest path to pass. Meanwhile, in the upstream part of the river there is still no deposition.
Then in the middle, with a flat area, the flow of water tends to be slow, resulting in the formation of meanders. Meander process occurs on the banks of the river, both on the inside and on the outside edge. Then the river that has a fast flow of water, will erode, while at the river’s edge with a slow flow of water, sedimentation will occur. Such a process if ongoing will form a meander.
2 # Oxbow lake
Meanders usually form in streams downstream. This occurs due to continuous erosion and sedimentation. The process of deposition that occurs continuously then results in the bend of the river being cut off and separated from the flow of the river, resulting in the formation of the oxbow lake, or what is also referred to as a dead river.
3 # Delta
When the flow of water begins to approach with the estuary, such as in a lake or sea, the water flow velocity that occurs will be slower. This causes sedimentation by river water. The sand is deposited, and the clay and mud will still be transported by the flow of water. After a long period of time, sedimentary layers are formed until finally these sedimentary layers form a wide plain in the river which approaches its mouth and forms a delta.
Delta formation must comply with several conditions. First, the sediment carried by the river must have a large amount, especially when going into the sea or lake. Second, the currents along the coast are not very strong. Third, the beach must be shallow. Examples of these landscapes are the Musi River, Kapuas, and Brantas River deltas.
4 # Natural dykes
Heavy rain that occurs can cause the volume of water to increase rapidly. This causes flooding and overflow of water to the river’s edge. then when the water recedes, the materials carried by this river water will settle to the riverbanks area which results in the formation of a plain on the river bank.
The emergence of material that is not smooth or rough on the river bank. This is what makes the river bank has a higher height than the floodplains formed. The landscape is called a river embankment. In addition, there is also a beach embankment which is the result of the deposition process that occurs due to the sea. Both embankments are natural embankments where the formation process takes place naturally as a result of natural workmanship.
- Sedimentation by Sea Water
Rocks resulting from deposition that occur due to sea water are known as marine sediments. Precipitation by sea water is due to waves. Examples of landscapes that have been deposited by sea water include coastal, spit, buttono, and beach barriers.
Coastal is a deposition area along the coast. Usually, the coast consists of sand material. The size and composition of the material on the coast varies greatly depending on changes in weather conditions, wind direction, and ocean currents.
Existing material is transported by coastal currents along the coast. If there is a change in direction, then the current will continue to carry material material into the deep sea. When the material enters the deep sea, there will be deposition of material.
After a long time, there will be accumulation of material that is above sea level. This material accumulation is called spit. If the coastline continues continuously, the spit will get longer.
Sometimes spits form over the bay and form a beach barrier. If there is an island around the split, the spit will be connected to the mainland, so that it will form a cako.
- Precipitation by the Wind
Sediments that are the result of deposition by the wind are called aeolis sediments. Landscapes that result from precipitation by the wind can be either sand dune or sand dune. Sand dune is caused by a large amount of sand accumulation and strong winds. The wind transports and settles the sand in a place gradually, which then causes the formation of sand heaps called sandbanks.
- Precipitation by Glaciers
Sediments that are the result of deposition by glaciers are called glacial sediments. Landscapes as a result of deposition by glaciers for example is the form of a valley that was originally V-shaped to become U.
If spring arrives, there will be erosion by glaciers sliding down the valley. Rocks or soil that is the result of erosion also down the slope and then settles in the valley. This resulted in the valley which was originally V-shaped to become U-shaped.
Thus our discussion this time is related to sedimentation, which includes the definition of sedimentation, the causes of sedimentation and also the type of sedimentation. Hopefully this article can provide the greatest possible benefits and help all friends to understand sedimentation in general. Have a good study.