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1. Rocks and Debris falls
Rock falls occur when a piece of rocks or a mass of rocks become dislodge and makes free-fall along a steep cliff. Debris fall is similar to rock fall, except that it involves a mixture of soil regolith, vegetation and rocks. At the base of the cliff in an accumulation of fallen materials called talus.
2. Landslides
Landslides are sudden fast movement of cohesive mass of soil, rock, or regolith. They occur in two types: Translation and Rotational slides. Translational slides involve the movement of a mass of materials along a well-defined surface, such as bedding plane, foliation surface, or joint surface. Rotational slides or slumps occur when the descending materials move en-masse along a concave, upward curved surface.
3. Flows
Flows may be slurry flows or granular flows. Slurry flows consists of mixtures of rocks or regolith with 20% to 40% of water. They are considered as water-saturated flows. Granular flows contain 0 to 20 % water. They are not saturated with water.
Slurry flows may be subdivided further on the based on velocity.
Although mass wasting is phenomenon, human activities may induce mass movement.
Running water is the primary agent of erosion on Earth. Most running water is found in streams and rivers.
There are different types of water erosion that affect landforms: Splash erosion, Sheet erosion, Gully erosion, Valley erosion, Bank erosion, Coastline erosion, Seaside cliff erosion.
A glacier is a thick large mass of ice formed hundreds or thousands of years mostly in remote areas like in the poles or in high mountains. They move very slowly.
Plucking is the process wherein fractured bedrocks are incorporated into the ice. This occurs when ice water freezes. It expands, loosens, and pulls out the rocks fragments, becoming part of the glacier.
The abrasional effect happens when the ice and its load of rock fragments slide over a bedrock. Abrasion smoothens and polishes the surface below. The result of abrasion may be rock flour (pulverized rock) or glacial striation (scratches and grooves) on the bedrock surface.
Mass Wasting is the mass movement of rocks, soil, and regolith. It is the step that follows weathering and is also a degradation process. The driving force of mass wasting is gravity. Although gravity is the controlling force, there are other factors that influence or trigger the down slope of anchoring vegetation and ground vibration of earthquakes.
Granular flows may be subdivided further based on velocity.
Frost wedging or Frost Weathering occurs in regions where temperature fluctuates above and below freezing point, resulting in a freeze-thaw cycle.
Water that enters through the cracks and empty spaces of rocks expands when it freezes. The ice exerts enormous outward force. When the ice thaws, water can flow further into the crack. Repeated freeze-thaw cycles weaken the rock and break up the rock into smaller pieces.
Mechanical Weathering or Disintegration is the breaking up of large rocks into smaller fragments without changing the rock’s mineral compositions.
There are physical processes that occur in nature break rocks into smaller pieces. It includes frost wedging, insolation weathring, unloading, and biological activity.
Unloading or Pressure Release occurs when the overlying rock is eroded away, causing the outer rock to expand more then the rock below. This expansion may separate the outer rock from the rock body. This process is evident in intrusive igneous rocks. Intrusive igneous rocks are formed deep beneath Earth’s surface. The overlying rock material exerts tremendous pressure on the igneous rock. When erosion removes the overlying materials, the presence on the igneous rocks is released, causing the outer portion to expand. Continued weathering causes sheets of rocks to break away. This exfoliation is due to the pressure released, often referred to as sheeting.
Insolation weathering or Thermal stress results from the expansion and contraction of rocks caused by temperature change. The coefficient of expansion differs for each mineral in the rock, resulting into different stress that may cause the rock to crack apart. Furthermore, the outer surface of the rock is warmer or colder than the inner portions, which may cause the peeling away of outer layers. The process of “peeling off” is called exfoliation.
Olivine + Water magnesium hydroxide + silicic acid in solution
*The reaction results in the dissolution of the original mineral.
Chemical Weathering decomposes rocks through chemical change.
The processes includes: Oxidation, Hydrolysis, Carbonation and solution, Biological Action.
Rates of Weathering
Rock characteristics include mineral composition, solubility and cracks. Variation in the composition of minerals in the rock results in differentiated weathering. Cracks are important because they influence the ability of water to seep through the rocks.
Climate, specifically, temperature and moisture, are two climatic factors are crucial to the rate of weathering. The freeze-thaw cycle, which is dependent on the temperature changes, affects the amount of frost wedging. The combination of warm temperature and abundant moisture is a very good environment for chemical weathering.
Carbon dioxide dissolves in water to form carbonic acid and reacts with the carbonate rocks to form a soluble product (calcium bicarbonate).
Some plants and animals may create chemical weathering by releasing chelating and audifying compounds that react with some minerals in rocks. Decaying remains of dead plants in soil may form organic acids and, when dissolved in water, may cause chemical weathering.
Wind
Wind caries dust, sand, and volcanic ash from one place to another. In dry areas, strong winds wears away soft rocks, and also polishes rocks and cliffs until they are smooth. Wind can also erode materials until nothing is left.
Transportation
Materials are transported in four distinct ways--- as solution, as suspension, by traction, or through saltation.
There are factors that affect the transportation of particles: particle weight, size, shape, surface configuration, medium type, resistance of particles to cohesions, and other environmental factors.
Deposition is the aggradation or accumulation of weathered sediments to create different landforms.
Water and Landforms
Whenever stream velocity decreases, it deposits the sediments it carries. The material deposits of stream is called alluvium.
Deltas are formed when river loses energy as it flows in to an area of slow-moving water, such as a lake or the sea.
Alluvial fans are formed when a stream reaches a flat area (called piedmont) or gently sloping plain.
Deltas are formed when river loses energy as it flows in to an area of slow-moving water, such as a lake or the sea.
Alluvial fans are formed when a stream reaches a flat area (called piedmont) or gently sloping plain.
Glaciers and Landforms
All unsorted deposits of rock formed directly by the ice are called glacial till.
Moraines are layers or ridges of till. A long pile of rocky material at the edge of a glacier is called lateral moraine while at the middle of the glacier is called medial moraine.
Esker is a winding ridge of sand and gravel deposited under a glacier by water melting from the ice.
Drumlins are streamlined asymmetrical hills composed of till. They may occur in clusters as drumlin fields.
Kames are steep-sided hills. Like eskers, they are composed of sand ang gravel.