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Types of Weathering and Causes of Soil Erosion

There are abrupt changes that are happening in our earth due to some human activities leading to environmental destruction. Likewise, there are some instances that many interactions of some elements and substances create substances to surroundings that is due to some phenomenal happenings. The earth is composed of elements and forces that give shape on it. In this lesson, you will know what and how weathering, erosion, and soil are linked together.


It is an interaction in the atmosphere or a process in which rocks are broken by the action of the atmosphere. This is relatively determinants of climate. There are two kinds of weathering, these are:

  1. Mechanical Weathering

It is the physical break-up of rock or mineral grains by surface processes. Break the rock into smaller pieces, but its pieces retains the characteristics of the origin. Its products are merely a smaller fragment of the original rock.

Types of Mechanical Weathering

  • Ice wedging- this is which the freezing water spread in rocks or bedding planes to where it wedges the rock apart.
  • Sheeting or unloading- this is where it results to certain fracture causes by the expansion of the rocks itself due to erosion.


Moreover, some animals and plants play minor roles in mechanical weathering. For instance, those burrowing animals like rodents they mechanically mix the soil and loose rock particles. Also the pressure from the growing roots, contributes in widening cracks and rock breakdown. Lichens can also extract nutrients from the minerals found in rocks.

2. Chemical weathering

This is the breakdown of minerals by chemical reaction with water, with other chemicals dissolved in water or with gasses in the air. Its most important agent is the water because it activates the weathering with the small amount of dissolved material. Its products are different substances from the original rock.

Three Main Groups of Chemical Weathering

  • Hydrolysis- it is the chemical union of water and mineral. It produces different mineral from the reaction of ions derived from one mineral. Example of this is the chemical weathering of feldspar.
  • Dissolution- it is a process whereby the rock material passes directly into the solution like salt in water. Carbonate minerals, calcite and dolomite are the most important minerals needed in the dissolution of the world.
  • Oxidation- it is the combination of atmospheric oxygen with a mineral to produce an oxide. This usually done with the process that contains high iron content like olivine, pyroxene and amphibole. Like of iron and oxygen form hematite or limonite.


It is a big force that breaks of transport rock particles from one place to another.

Agents of Erosion

  1. Wind- it is an agent in which it continuously carries away the loose particles or rock and soil to another place to where it deposits the dust in wide areas where the hills of sands are formed.
  2. Waves- it has an erosion power, especially the large waves that can tear up ashore. The continuous pounding of waves along the edges of the land can destroy the land that was called wave erosion.
  3. Gravity- it is the erosion why water flows. It gives water the power to erode and carry away the rock materials. It also erodes the land alone. There are rocks pulled down by the gravity, especially at the base of the mountain. If the rocks on a steep slope are loosened, they tend to roll down-side. Then the sudden and massive downward movement of rock is a landslide.
Soil Erosion

Soil Erosion

Effects of Soil Erosion

  • It may form caves, beaches or resorts
  • Deterioration of farmlands and forests
  • Occurrences of floods and droughts
  • Siltation of rivers and water reservoir
  • Destruction of houses and infrastructure
  • Rich topsoil are washed away
  • Water shortage
  • Landslide

4. Glaciers- it erodes land in two different ways:

  • It flows over a fracture bedrock surface. This involved the process of plucking wherein the melted water penetrates the cracks and joins along the rock floor of the glacier and then freezes. It loosens and lift up the blocks of rocks accompanied into the ice and carries them off.
  • Abrasion, this is also a process where the ice moves along. It acts as giant rasp and it grinds the surface below within of it. The pulverized rock that produced by the glacial”grist mill” is called as rock floor. Causes of erosion
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Commonly knows that the main cause of soil erosion is the water due to heavy rain brought by typhoons and monsoon wind. By with that, floods suddenly made up an amount of sediments in a land are scraped by run-off and carried into rivers and seas.

Much worst the man himself creates soil erosion because of such practices like shifting cultivation, timber harvesting or logging, mining, construction projects and overgrazing and burning of grassland. As the results, forests now are unclear tress are burned and even agricultural crops are planted which is a good proof of the presence of shifting agriculture.

Thus, it loses the fertility of the soil because of not replanting the usable land with forest trees. Also, continuous cutting of trees removes the vegetation that protects the soil. Another, mining operations also contributed a lot to soil erosion because millions of tons of rocks are being cleansed. Lastly, the uncontrolled grazing of too many animals removes the grass cover, especially grassland fires most often makes the soil bare.

Glacial Landforms Erosion

How to Control Soil Erosion

  • The preventive method

This involved the fire prevention, proper land use, correct range and forest management, proper road construction and education of the people.

  • Rehabilitative method

This involves the vegetative method in which it covers cropping, strip-cutting, contour tillage and terracing.

  • Engineering structures(mechanical method)
  • Cultivated crops
  • Terracing
  • Rip rapping


It is a combination of mineral and organic matter (45%), water (25%), and air(25%). It contains bicarbonates, chlorides, nitrates, phosphates, and sulfate.

The soil profile

As time passes, the soil is divided into zones or layers known as horizons. There are four basic horizons from top to bottom designated as O, A, B and C.

O- horizon- consist largely the organic material. This is where we can find plant litter like loose leaves and other organic debris.

A-horizon- this is the darkest layer. It consist most of the organic matter or humus. This where we can find all living in microcosm clay and insoluble materials are mostly present here.

B-horizon (subsoil) or the zone of accumulation- it consist of little organic matter and soluble material

C-horizon- this is the lowest layer of the soil. It consist a slightly altered bedrock with broken or decayed materials with clay. This is where we can find the solid bedrock.

The Soil Types

  • Pedalfer- this gives the basic characteristic of soil type. It is from the Greek pedon means “soil” and from the chemical symbols A (aluminum) and Fe (iron). This is characterized by iron oxides and aluminum in the B-horizon.
  • Pedocal- also it is from the Greek pedon means “soil” and first three letters of calcite. This is where rainfall evaporates before it removes the soluble materials. It contains generally a smaller amount of clay minerals.
  • Laterites- it is formed from the hot wet climates of the tropics. This is where the chemical weathering occurs. A soluble material is not removing in this type but also great amount of water is removed due to the accumulation of the iron oxides and aluminum.


sheilamyers on June 09, 2014:

Ken: Unfortunately, I haven't yet found a job in my field. Maybe one of these days.

Kenneth C Agudo (author) from Tiwi, Philippines on June 08, 2014:

Wow, so you are working as environmentalist? or natural geologist (lol is is there natural geologist) Impressive, you really love your coarse because I don't like my coarse, and that's true, I wanted to become a doctor but my mom can't afford it. I always wanted to become a nurse or doctor, you are lucky sheila.

sheilamyers on June 08, 2014:

Ken: I studied environmental conservation with a focus on wildlife management. I took the a couple geology courses. One (the basic class) was required and the other was environmental geology (an elective) in which we learned how activity affected nature and nature affected various activities.

Kenneth C Agudo (author) from Tiwi, Philippines on June 08, 2014:

Hi Shela: Really, you took geology course in college, oh this is the reason why you are very interested on such topics i wrote here on hubpages. thing makes me know you better, I see, in our place its cause by human activity and sometimes its gravity. Thank you for reading again :)

sheilamyers on June 05, 2014:

I had to read your descriptions before answering your poll. Most erosion around my area, by your description, is by gravity. We have a lot of hills and the rain will wash them down when we get hard, prolonged storms. We also have erosion caused by the numerous creeks, streams, and rivers. This was a very interesting and informative hub. It's a good refresher of the basics I learned in the environmental geology course I took in college.

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