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Constructive landforms
What is a Landform
Landforms created by crustal deformationLanforms created from volcanic activityFormation of landforms from sediment depositionWeathering factor of landformsLandforms created by erosionKinds of landformsFormation of a canyon landformformation of cape and formation of peninsulaFormation of coastline landformsFormation of continental shelf landformsFormation of a delta landformFormation of desert landformsFormation of glaciersHow do islands formHow do isthmus landforms formFormation of mountain landformsHow fo plains formHow do Plateaux landform formHow do sand dunes formHow do valleys formDestructive landforms
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Genetic engineering
Green energy
crude oil
Effects of overfishing
Water shortage
climate change
DeforestationThe ozone layer
Waste management
Wasting foodNatural resources for children

How is a landform created


How does weathering shape landforms?


Weathering is the breakdown or loosening of surface minerals of rocks after they are exposed to weathering agents such as water, oxygen (air), organic and inorganic chemicals and temperature. Weathering occurs in place (in situ). Weathering is the event that comes before erosion sets in. Weathering is responsible for many wonderful landforms usually seen in coastal areas.

In Australia, great natural icons such as Uluru (Ayers Rock), the Twelve Apostles and Karlwekarlwe (The Devil’s Marbles), as well as the Grand Canyon in the USA, glacial landscapes in Europe and the huge dune fields of the Sahara Desert in Africa are all examples of weathering and erosion in actionLandform References PDF.

Erosion or Weathering?
It is important not to confuse erosion with weathering. The difference is, weathering determines what can be eroded. It is the breakdown of the rock itself. Erosion is when the weathered material is transported to another place by water, wind or ice. Erosion produces landforms that are often tall and jagged, but deposition usually produces landforms on flat, low land.

Weathering is considered a destructive process in landform formation. The extent of weathering often depends on the makeup of the land, time, and climate (water, wind and temperature)

Types of Weathering
There are three types of weathering — Physical, Chemical and Biological. Here is a brief description of them.

Physical or Mechanical Weathering:
The illustration below shows how a rock can undergo physical weathering.
What is physical weathering
This kind of rock breakdown is mechanical in nature. The chemical composition of the rock material is not affected. It results only in smaller pieces of the parent rock at the same place. Physical weathering is caused by temperature changes, salt crystallization, frost and dust wedging, aeolian abrasion, unloading and so on.

Chemical weathering:
The illustration below shows how a rock can undergo physical weathering.
What is chemical weathering

This kind of breakdown is due to the chemical reaction of the rock mineral to compounds in air and water present. Chemical weathering can result in the change in the chemical composition of the residual debris, and also change in its color and smell. Some chemical processes in weathering include Hydration, Oxidation, Hydrolysis, Leaching and Carbonation.

Biological weathering:
This is almost a combination of physical and chemical activity, but usually the action of plant roots, animals and insects getting into rock crevices and exposing them to chemical and climatic action.

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Sources:
1. Weathering, erosion, landforms and regolith Teacher notes and student activities Megan E. Lech and Cindy L. Trewin 2nd Edition

Landform diagrams

How is a landform created